WO2006089586A1 - Use of a compound with clusterin activity for the treatment of diseases associated with the deposition of abnormal proteins - Google Patents

Abstract

The present invention relates to the use of a compound with clusterin activity or a compound promoting or enhancing clusterin activity for the preparation of a medicament for treatment or prevention of diseases which are associated with modification of proteins or deposition of abnormal proteins.

Description

USE OF A COMPOUND WITH CLUSTERIN ACTIVITY FOR THE TREATMENT OF DISEASES ASSOCIAT ED WITH THE DEPOSITION OF ABNORMAL PROTEINS

The present invention relates to the use of a compound with clusterin activity or a compound promoting or enhancing cluster- in activity.

Clusterin (also described as pADHC-9, SGP-2, TRPM-2, SP-40,40, CLI, ApoJ, T64, GP III, GP80, XIP8) is a multifunctional protein, being constitutively expressed in almost all mammalian tissues and found in most human fluids (plasma, milk, urine, cerebrospinal fluid and semen) (Jones et al., 2002). The high degree of conservation (~70-85% in mammalian species) , the absence of polymorphism and the wide tissue distribution suggests a fundamental biological function of clusterin (Trougakos et al., 2002). It has been described as lipid-transporter, cell adhesion molecule, to bind bacteria, to be involved in apoptosis (pro- as well as anti-apoptotic function) and in numerous other processes, including stress response (Jones et al., 2002; Trougakos et al., 2002) .

According to its multiple functions, clusterin was found in different variants and localizations . Following treatment of cells with transforming growth factor-β (TGF-β) (Reddy et al., 1996) or ionizing radiation, a non-glycozylated splicing variant of clusterin appears in the nucleus (nClu) . It has been suggested that an inactive precursor nClu exists in the cytoplasm and translocates in the nucleus following ionizing radiation, where the mature nClu interacts with the DNA-binding protein Ku70 and induces apoptosis (Leskov et al., 2003; Yang et al., 2000). These results are supported by the fact, that clusterin contains at least two nuclear localization signals .

A cytoplasmic localization (cClu) has been described rarely (De- bure et al., 2003; Trougakos et al., 2002), however, cannot be excluded, since the clusterin homologue of chicken is not secreted and retained intracellularly (Mahon et al., 1999). Recently it has been reported that an ubiquitinated form of clusterin forms juxtanuclear aggregates in the cytoplasm, similar to aggresomes (Debure et al., 2003). Clusterin could eventually escape the secretory pathway, particularly in pathologic situ- ations with damage of the endoplasmic reticulum or modification of the chemical composition of the protein, and accumulate in the cytoplasmic compartment. Moreover, intracellular clusterin could also result through an uptake of extracellular protein.

The predominant form of clusterin is a secreted disulfide-linked heterodimeric glycoprotein (sClu) of 75-80 kDa (Jones et al., 2002) . The single-copy gene with the coding sequence is localized on chromosome 8. The primary translation product is a polypeptide of 449 amino acids, including a hydrophobic 22-mer signal peptide. Secreted clusterin is translated on membrane-bound ribosomes directly in the endoplasmic reticulum with cleavage of the signal peptide. In the endoplasmic reticulum, the mannose- rich polypeptide is glycozylated and forms five disulfide bridges. After transport to the Golgi apparatus, clusterin is proteolytically cleaved, generating its α and β subunits . After final glycozylation steps, the sClu is secreted in the extracellular space (Jones et al., 2002; Trougakos et al . , 2002; Wilson et al., 2000) . Once secreted, clusterin can be bound by the megalin/gp330 receptor and uptaken in the cell (Debure et al., 2003; Kounnas et al., 1995; Mahon et al., 1999).

Clusterin has been suggested to be used for the treatment or-> prevention of peripheral neurological diseases because clusterin was found to have a beneficial effect in an animal model of peripheral neuropathy (WO 2004/084932 A) . As examples for such peripheral neurological diseases, traumatic nerve injury, nerve trauma, peripheral nerve system (PNS) infections, demyelating diseases of the PNS, neuropathies of the PNS, or carpal tunnel syndrome are mentioned.

In WO 02/22635 A, US 2002/0128220 A and WO 2004/018675 A reduction of clusterin level by antisense modulation has been suggested to treat hypercholesterolemia, cardiovascular disorders, hy- perproliferative disorders, hyperlipidemic disorders, prostate or renal cell cancer, and melanoma.

It was also mentioned in WO 02/22635 A that the level of clusterin is increased in the hippocampus and frontal cortex of the brains of Alzheimer's disease patients and that clusterin acts to link the progression of this disease to the complement system.

Various diseases are characterized by the occurrence of misfol- ded and aggregated proteins. These so called protein aggregation diseases have heterogeneous aetiologies, and include disorders such as Parkinson disease, Huntington disease, αl-an- titrypsin (αl-AT) deficiency, amyloidoses, and alcoholic as well as non-alcoholic steatohepatitis (ASH and NASH) . Mallory bodies (MBs) are a prototype of cytoplasmic protein aggregates, which occur in a variety of chronic toxic and metabolic liver disorders, including ASH and NASH. MBs are formed from abnormally folded keratins, mainly keratin 8, and a variety of stress proteins (Zatloukal et al. 2000, 2002). Biochemical as well as im- munohistochemical analyses revealed that MBs are highly ubiguit- inated and constantly contain p62 (Zatloukal et al., 2002; Stumptner et al., 2002). This indicates that in liver diseases with MBs, improperly assembled keratins are recognized as mis- folded proteins and are the major target of a stress response.

Protein aggregation diseases are characterized by the occurrence of abnormal proteins, which aggregate intracellularly or in the extracellular space. Misfolding of proteins is a result of structural modification, which is typically caused by oxidative cell injury or mutation. The oxidative attack on proteins may lead to amino acid modification, fragmentation, and loss of secondary structure. Therefore, affected proteins expose hydrophobic residues, favoring aggregation due to hydrophobic interactions and cross-linking reactions (Grune et al . , 1997).

Currently, diseases or disorders associated with the occurrence of misfolded or aggregated proteins are either not curable at all or are treated with very different medications or treatments . Moreover, prophylaxis of such diseases or disorders is often impossible due to lack of suitable early stage markers. On the other hand, due to the side effects connected with some treatments for such disorders a prophylactic administration, especially for low or non-high risk patients, is not possible.

It is an object of the present invention to provide a suitable prophylactic or therapeutic method for diseases or disorders which are connected or caused by modified or aggregated proteins or - at least - to provide temporal amelioration or slowing down of progression or of the symptoms being connected with the protein aggregation in such disorders .

Therefore, the present invention provides the use of a compound with clusterin activity or a compound promoting or enhancing clusterin activity for the preparation of a medicament for treatment or prevention of diseases which are associated with modification of proteins or deposition of abnormal proteins .

It could be shown by the present invention that clusterin has a function in the stress response to misfolded keratins. Surprisingly, clusterin has the ability to bind misfolded proteins of various nature, including keratins and components of elastic fibers . Although the physiological function of clusterin as a binding protein to abnormal proteins is preferably the extracellular space (and extracellular space is the preferred locus of clusterin action according to the present invention) , also intracellular action of clusterin is enabled by the present invention as well as the direction or the targeting to specific cell compartments ofφ'cells, e.g. by providing suitable modifications in the signal sequence, such as deletion or truncation of the signal sequence .

Moreover, clusterin was constantly found in association with amyloid plaques in immunohistochemical studies in Alzheimer disease. Clusterin was also found in association with elastic fibers in the extracellular matrix in several chronic liver diseases, including ASH and αl-antitrypsin deficiency, demonstrating the role of clusterin in liver fibrosis . Furthermore clusterin was found in association with elastic fibers in elast- ofibromas, aged skin, lung, and sclerotic arteries. The binding of clusterin to altered extracellular proteins is not restricted to elastic fibers and β-amyloid. Clusterin was also found in association with hyaline membranes in lungs with adult respiratory distress syndrome and in aged skin in association with extracellular proteins, which were negative for elastin. As mentioned above, clusterin is a highly conserved (~70-85% in mammalian species), multifunctional glycoprotein (Jones et al., 2002; Trougakos et al., 2002). sClu has chaperone-like activity. Secreted clusterin forms oligomers in the extracellular space. Active heterodimers dissociate from the inactive oligomers by acidic pH. sClu is able to bind to exposed hydrophobic regions of misfolded proteins in an ATP-independent manner and to stabilize them in a folding-competent state by forming soluble "high molecular weight complexes". Similar to sHsps, clusterin is unable to refold proteins, but they have been described to be competent for refolding by heat shock protein 70 (Hsp70) , but an extracellular folding-competent chaperone has not been identified, yet. As opposed to Hsps, its chaperone action is not enhanced by increasing temperatures, but by acidic pH. Thus, clusterin is the first identified extracellular chaperone (Humphreys et al., 1999; Poon et al., 2000; Poon et al., 2002; Wilson et al., 2000) .

Compounds with clusterin activity according to the present invention may be any functionally active or activatable molecule with clusterin activity. Preferred examples of such molecules are described in WO 2004/084932 A, incorporated herein by reference with respect to all forms of clusterin molecules and clusterin activating compounds . Specifically preferred are all physiologically occurring forms of clusterin, especially human clusterin. The sequence of human clusterin is known, e.g. from WO 2004/084932 A (disclosed therein as Seq.ID.No. 1) . According to the present invention, any clusterin derived from animals, especially mammals, such as murine, bovine, porcine, feline or ovine clusterin, are suitable molecules with clusterin activity as long as there is sufficient similarity in order to maintain clusterin activity in e.g. humans, and as long as the resulting molecule will not be immunogenic in humans . Further compounds with clusterin activity include biologically active muteins and fragments of clusterin, such as the naturally occurring alpha and beta subunit of clusterin, isoforms, fused proteins, functional derivatives, active fractions or fragments, or circularly permutated derivatives, or salts thereof, as disclosed in WO 2004/084932 A. Preferably, the clusterin is selected from a peptide, a polypeptide or a protein selected from the group consisting of: a) A polypeptide comprising SEQ ID NO: 1; b) A polypeptide comprising amino acids (aa) 23 to 449 of SEQ ID NO: 1; c) A polypeptide comprising aa 35 to 449 of SEQ ID NO: 1; d) A polypeptide comprising aa 23 to 227 of SEQID NO: 1; e) A polypeptide comprising aa 35 to 227 of SEQ ID NO: 1; f) A polypeptide comprising aa 228 to 449 of SEQ ID NO: 1; g) A mutein of any of (a) to (f) , wherein the amino acid sequence has at least 40 % or 50 % or 60 % or 70 % or 80 % or 90 % identity to at least one of the sequences in (a) to (f) , h) A mutein of any of (a) to (f) which is encoded by a DNA sequence which hybridizes to the complement of the native DNA sequence encoding any of (a) to (f) under moderately stringent conditions or under highly stringent conditions_/ i) A mutein of any of (a) to (f) wherein any changes in the amino acid sequence are conservative amino acid substitutions to the amino acid sequences in (a) to (f) ; j) a salt or an isoform, fused protein, functional derivative, active fraction or circularly permutated derivative of any of (a) to (f) .

Active fractions or fragments may comprise any portion or domain of clusterin, such as the alpha chain or the beta chain separated, or linked to each other e. g. via disulfide bridges, directly fused, or fused via an appropriate linker. Active fractions also comprise differentially glycozylated or sialylated forms of clusterin.

The person skilled in the art will appreciate that even smaller portions of clusterin or its two subunits may be enough to exert its function, such as an active peptide comprising the essential amino acid residues required for clusterin function.

The person skilled in the art will further appreciate that muteins, salts, isoforms, fused proteins, functional derivatives of clusterin, active fractions or circularly permutated derivatives of clusterin, will retain a similar, or even better, biological activity of clusterin. The biological activity of cluster- in and muteins, isoforms, fused proteins or functional derivatives, active fractions or fragments, circularly permutated derivatives, or salts thereof, may be measured in a co- culturing assay.

Preferred active fractions have an activity which is equal to or better than the activity of full-length clusterin, or which have further advantages, such as a better stability or a lower toxicity or immunogenicity, or they are easier to produce in large quantities, or easier to purify. The person skilled in the art will appreciate that muteins, active fragments and functional derivatives can be generated by cloning the corresponding cDNA in appropriate plasmids and testing them in the co-culturing assay, as mentioned above .

The proteins according to the present invention may be gly- cozylated or non-glycozylated, they^" may be derived from natural sources, such as body fluids, or they may preferably be produced recombinantly. Recombinant expression may be carried out in prokaryotic expression systems such as E. coli, or in eukaryot- ic, such as insect cells, and preferably in mammalian expression systems, such as CHO-cells or HEK-cells.

As used herein the term "muteins" refers to analogs of cluster- in, in which one or more of the amino acid residues of a natural clusterin are replaced by different amino acid residues, or are deleted, or one or more amino acid residues are added to the natural sequence of clusterin, without changing considerably the activity of the resulting products as compared with the wild- type clusterin. These muteins are prepared by known synthesis and/or by site-directed mutagenesis techniques, or any other known technique suitable therefore.

Muteins of clusterin, which can be used in accordance with the present invention, or nucleic acid coding thereof, include a finite set of substantially corresponding sequences as substitution peptides or polynucleotides which can be routinely obtained by one of ordinary skill in the art, without undue experimentation, based on the teachings and guidance presented herein. Muteins in accordance with the present invention include proteins encoded by a nucleic acid, such as DNA or ENA₇. which hybridizes to DNA or RNA₇. which encodes clusterin, in accordance with the present invention, under moderately or highly stringent conditions. The term "stringent conditions" refers to hybridization and subsequent washing conditions, which those of ordinary skill in the art conventionally refer to as "stringent". See Ausubel et al., Current Protocols in Molecular Biology, supra, Interscience, N. Y. , 6.3 and 6.4 (1987,1992), and Sambrook et al. (Sambrook, J. C, Fritsch, E. F., and Maniatis, T. (1989) Molecular Cloning : A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY) .

Without limitation, examples of stringent conditions include washing conditions 12-20° C below the calculated Tm of the hybrid under study in, e.g., 2 x SSC and 0.5% SDS for 5 minutes, 2 x SSC and 0.1% SDS for 15 minutes; 0.1 x SSC and 0.5% SDS at 37° C for 30-60 minutes and then, a 0.1 x SSC and 0.5% SDS at 68°C for 30-60 minutes. Those of ordinary skill in this art understand that stringency conditions also depend on the length of the DNA sequences, oligonucleotide probes (such as 10-40 bases) or mixed oligonucleotide probes. If mixed probes are used, it is preferable.'..to use tetramethyl ammonium chloride (TMAC) instead of SSC (see Ausubel, supra) .

In a preferred embodiment, any such mutein has at least 40% identity or homology with the sequence of SEQ ID NO: 1 of the annexed sequence listing. More preferably, it has at least 50%, at least 60%, at least 70%, at least 80% or, most preferably, at least 90% identity or homology thereto. Identity reflects a relationship between two or more polypeptide sequences or two or more polynucleotide sequences, determined by comparing the sequences .

In general, identity refers to an exact nucleotide to nucleotide or amino acid to amino acid correspondence of the two polynucleotides or two polypeptide sequences, respectively, over the length of the sequences being compared.

For sequences where there is not an exact correspondence, a "% identity" may be determined. In general, the two sequences to be compared are aligned to give a maximum correlation between the sequences. This may include inserting "gaps" in either one or both sequences, to enhance the degree of alignment. A % identity may be determined over the whole length of each of the sequences being compared (so-called global alignment) , that is particularly suitable for sequences of the same or very similar length, or over shorter, defined lengths (so-called local alignment) , that is more suitable for sequences of unequal length.

Methods for comparing the identity and homology of two or more sequences are well known in the art. Thus for instance, programs available in the Wisconsin Sequence Analysis Package, version 9.1 (Devereux et al., 1984), for example the programs BESTFIT and GAP, may be used to determine the % identity between two polynucleotides and the % identity and the % homology between two polypeptide sequences. BESTFIT uses the "local homology" algorithm of Smith and Waterman (Smith et al., 1981) and finds the best single region of similarity between two sequences. Other programs for determining identity and/or similarity between sequences are also known in the art, for instance the BLAST family of programs (Altschul et al., 1990; Altschul et al., 1997), accessible through the home page Oϊfi the NCBI at www. ncbi.nim.ni- h.gov) and FASTA (Pearson, 1990; Pearson et al., 1988).

Preferred changes for muteins in accordance with the present invention are what are known as "conservative" substitutions. Conservative amino acid substitutions of clusterin polypeptides, may include synonymous amino acids within a group which have sufficiently similar physicochemical properties that substitution between members of the group will preserve the biological function of the molecule (Grantham, 1974) . It is clear that insertions and deletions of amino acids may also be made in the above-defined sequences without altering their function, particularly if the insertions or deletions only involve a few amino acids, e. g. fewer than thirty, and preferably under ten, and do not remove or displace amino acids which are critical to a functional conformation, e.g. cysteine residues. Proteins and muteins produced by such deletions and/or insertions come within the purview of the present invention. Preferably, the synonymous amino acid groups are the following (amino acid synonymous group in brackets) : Ser (Ser, Thr, GIy, Asn) , Arg (Arg, GIn, Lys, GIu, His), Leu (lie, Phe, Tyr, Met, VaI, Leu) , Pro (GIy, Ala, Thr, Pro) , Thr (Pro, Ser, Ala, GIy, His, GIn, Thr), Ala (GIy, Thr, Pro, Ala), VaI (Met, Tyr, Phe, lie, Leu, VaI) , GIy (Ala, Thr, Pro, Ser, GIy) , lie (Met, Tyr, Phe, VaI, Leu, lie) , Phe (Trp, Met, Tyr, lie, VaI, Leu, Phe) , Tyr (Trp, Met, Phe, lie, VaI, Leu, Tyr), Cys (Ser, Thr, Cys) , His (GIu, Lys, GIn, Thr, Arg, His) , GIn (GIu, Lys, Asn, His, Thr, Arg, GIn), Asn (GIn, Asp, Ser, Asn), Lys (GIu, GIn, His, Arg, Lys) , Asp (GIu, Asn, Asp) , GIu (Asp, Lys, Asn, GIn, His, Arg, GIu) , Met (Phe, lie, VaI, Leu, Met) and Trp (Trp) .

More preferably, the synonymous amino acid groups are the following: Ser (Ser) , Arg (Arg, Lys, His) , Leu (He, Phe, Met, Leu) , Pro (Ala, Pro) , Thr (Thr) , Ala (Pro, Ala) , VaI (Met, He, VaI) , GIy (GIy) , He (Met, Phe, VaI, Leu, lie) , Phe (Met, He, Tyr, Leu, Phe) , Tyr (Phe, Tyr) , Cys (Ser, Cys) , His (GIn, Arg, His) , GIn (GIu, His, GIn) , Asn (Asp, Asn) , Lys (Arg, Lys) , Asp (Asn, Asp) , GIu (GIn, GIu) , Met (Phe, He, VaI, Leu, Met) and Trp (Trp) .

Most preferably the synonymous amino acid groups are the following: Ser (Ser) , Arg (Arg) , Leu (He, Met, Leu) , Pro (Pro) , Thr (Thr) , Ala (Ala) , VaI (VaI) , GIy (GIy) , He (Met, Leu, He) , Phe (Phe), Tyr (Tyr), Cys (Ser, Cys), His (His), GIn (GIn), Asn (Asn), Lys (Lys), Asp (Asp), GIu (GIu), Met (He, Leu, Met) and Trp (Trp) . ^■

Examples of production of amino acid substitutions in proteins which can be used for obtaining muteins of clusterin, polypeptides or proteins, for use in the present invention include any known method steps, such as presented in US patents 4,959,314, 4,588,585 and 4,737,462, to Mark et al.; 5,116,943 to Koths et al., 4,965,195 to Namen et al.; 4,879,111 to Chong et al., and 5,017,691 to Lee et al.); And lysine substituted proteins presented in US patent No. 4,904,584 (Shaw et al.). The term "fused protein" refers to a polypeptide comprising clusterin, or a mutein or fragment thereof, fused with another protein, which e.g. has an extended residence time in body fluids . Clusterin may thus be fused to another protein, polypeptide or the like, e.g. an immunoglobulin or a fragment thereof. Immunoglobulin Fc portions are particularly suitable for production of di- or mulitmeric Ig fusion proteins . The alpha- and beta-chain of clusterin may e.g. be linked to portions of an immunoglobulin in such a way as to produce the alpha- and beta- chain of clusterin dimerized by the Ig Fc portion.

"Functional derivatives" as used herein, cover derivatives of clusterin, and their muteins and fused proteins, which may be prepared from the functional groups which occur as side chains on the residues or the N-or C-terminal groups, by means known in the art, and are included in the invention as long as they remain pharmaceutically acceptable, i.e. they do not destroy the activity of the protein which is substantially similar to the activity of clusterin, and do not confer toxic properties on compositions containing it .

These derivatives may, for example, include polyethylene glycol side-chains, which may mask antigenic sites and extend the residence of clusterin in body fluids .

Other derivatives include aliphatic esters of the carboxyl groups, amides of the carboxyl groups by reaction with ammonia or with primary or secondary amines, N-acyl derivatives of free amino groups of the amino acid residues formed with acyl moieties (e.g. alkanol or carbocyclic aroyl groups) or 0-acyl derivatives of free hydroxyl groups (for example that of seryl or threonyl residues) formed with acyl moieties.

As "active fractions" of clusterin, muteins and fused proteins, the present invention covers any fragment or precursors of the polypeptide chain of the protein molecule alone or together with associated molecules or residues linked thereto, e.g. sugar or phosphate residues, or aggregates of the protein molecule or the sugar residues by themselves, provided said fraction has substantially similar activity to clusterin. The term "salts" herein refers to both salts of carboxyl groups and to acid addition salts of amino groups of clusterin molecule or analogs thereof. Salts of a carboxyl group may be formed by means known in the art and include inorganic salts, for example, sodium, calcium, ammonium, ferric or zinc salts, and the like, and salts with organic bases as those formed, for example, with amines, such as triethanolamine, arginine or lysine, piperidine, procaine and the like. Acid addition salts include, for example, salts with mineral acids, such as, for example, hydrochloric acid or sulfuric acid, and salts with organic acids, such as, for example, acetic acid or oxalic acid. Of course, any such salts must retain the biological activity of clusterin relevant to the present invention.

Functional derivatives of clusterin may be conjugated to polymers in order to improve the properties of the protein, such as the stability, half-life, bioavailability, tolerance by the human body, or immunogenicity. To achieve this goal, clusterin may be linked e. g. to polyethlyenglycol (PEG) . PEGylation may be carried out by known methods, described in WO 92/13095, for example. Therefore, in a preferred embodiment of the present invention, clusterin is PEGylated. Λ-.-

In a further preferred embodiment of the invention, the fused protein comprises an immunoglobulin (Ig) fusion. The fusion may be direct, or via a short linker peptide which can be as short as 1 to 3 amino acid residues in length or longer, for example, 13 amino acid residues in length. Said linker may be a tripeptide of the sequence E-F-M(Glu-Phe-Met) , for example,- or a 13-amino acid linker sequence comprising Glu-Phe-Gly-Ala-Gly- Leu-Val-Leu-Gly-Gly-Gln-Phe-Met introduced between clusterin sequence and the immunoglobulin sequence, for instance. The resulting fusion protein has improved properties, such as an extended residence time in body fluids (half-life) , an increased specific activity, or increased expression level. The Ig fusion may also facilitate purification of the fused protein.

In a yet another preferred embodiment, clusterin or one or both subunits are fused to the constant region of an Ig molecule. Preferably, it is fused to heavy chain regions, like the CH2 and CH3 domains of human IgGl, for example. Other isoforms of Ig molecules are also suitable for the generation of fusion proteins according to the present invention, such as isoforms IgG 2 or IgG4, or other Ig classes, like IgM, for example. Fusion proteins may be monomeric or multimeric, hetero- or homomultimeric. The immunoglobulin portion of the fused protein may be further modified in a way as to not activate complement binding or the complement cascade or bind to Fc-receptors .

In the following description "clusterin" always includes all ^wcompounds with clusterin activity", wherever appropriate.

The invention further relates to the use of a combination of clusterin and an immunosuppressive agent for the manufacture of a medicament for treatment and/or prevention of peripheral neurological disorders, for simultaneous, sequential or separate use. Immunosuppressive agents may be steroids, methotrexate, cyclophosphamide, anti-leukocyte antibodies (such as CAMPATH-I) , and the like.

The invention further relates to the use of a combination of clusterin and interferons, especially INF-alpha, IFN-beta, IFN- gamma) , interleukins, especially IL-2, IL-6 or IL-12, heparin or osteopontin.

In a preferred embodiment of the present invention, clusterin is used in an amount of about 0.001 to 100 mg/kg of body weight, or about 1 to 10 mg/kg of body weight or about 5 mg/kg of body weight.

The clusterin nucleic acid may e.g. be administered as a naked nucleic acid molecule, e.g. by intramuscular injection.

It may further comprise vector sequences, such as viral sequence, useful for expression of the gene encoded by the nucleic acid molecule in the human body, preferably in the appropriate cells or tissues. Therefore, in a preferred embodiment, the nucleic acid molecule further comprises an expression vector sequence. Expression vector sequences are well known in the art, they comprise further elements serving for expression of the gene of interest. They may comprise regulatory sequence, such as promoter and enhancer sequences, selection marker sequences, origins of multiplication, and the like. A gene therapeutic approach is thus used for treating and/or preventing the disease. Advantageously, the expression of clusterin will then be in situ.

In a preferred embodiment of the invention, the expression vector may be administered by intramuscular injection.

The use of a vector for inducing and/or enhancing the endogenous production of clusterin in a cell normally silent for expression of clusterin, or which expresses amounts of clusterin which are not sufficient, are also contemplated according to the invention. The vector may comprise regulatory sequences functional in the cells desired to express clusterin. Such regulatory sequences may be promoters or enhancers, for example. The regulatory sequence may then be introduced into the appropriate locus of the genome by homologous recombination, thus operably linking the regulatory sequence with the gene, the expression of which is required to be induced or enhanced. The technology is usually referred&to as "endogenous gene activation" (EGA) , ands it is described e.g. in WO 91/09955.

The invention further relates to the use of a cell that has been genetically modified to produce clusterin in the manufacture of a medicament for the disorders claimed. Thus, a cell therapeutic approach may be used in order to deliver the drug to the appropriate parts of the human body.

The invention further relates to pharmaceutical compositions, particularly useful for prevention and/or treatment of the disorders claimed, which comprise a therapeutically effective amount of clusterin.

The definition of "pharmaceutically acceptable" is meant to encompass any carrier, which does not interfere with effectiveness of the biological activity of the active ingredient and that is not toxic to the host to which it is administered. For example, for parenteral administration, the active protein (s) may be formulated in a unit dosage form for injection in vehicles such as saline, dextrose solution, serum albumin and Ringer's solution.

The active ingredients of the pharmaceutical composition according to the invention can be administered to an individual in a variety of ways . The routes of administration include intradermal, transdermal (e.g. in slow release formulations), intramuscular, intraperitoneal, intravenous, subcutaneous, oral, epidural, topical, intrathecal, rectal, and intranasal routes. Any other therapeutical efficacious route of administration can be used, for example absorption through epithelial or endothelial tissues or by gene therapy wherein a DNA molecule encoding the active agent is administered to the patient (e. g. via a vector) , which causes the active agent to be expressed and secreted in vivo. In addition, the protein (s) according to the invention can be administered together with other components of biologically active agents such as pharmaceutically acceptable surfactants, excipients, carriers, diluents and vehicles.

For parenteral (e.g. intravenous, subcutaneous, intramuscular) administration, the active protein (s) can be formulated as a solution, suspension, emulsion or lyophilized powder in association with a pharmaceutically acceptable parenteral vehicle (e.g. water, saline, dextrose solution) and additives that maintain isotonicity (e g. mannitol) or chemical stability (e.g. preservatives and buffers) . The formulation is sterilized by commonly used techniques.

The bioavailability of the active protein (s) according to the invention can also be ameliorated by using conjugation procedures which increase the half-life of the molecule in the human body, for example linking the molecule to polyethlyenglycol, as described in WO 92/13095.

The therapeutically effective amounts of the active protein (s) will be a function of many variables, including the type of protein, the affinity of the protein, any residual cytotoxic activity exhibited by the antagonists, the route of administration, the clinical condition of the patient (including the desirability of maintaining a non-toxic level of endogenous clusterin activity) .

A "therapeutically effective amount" is such that when administered, the clusterin exerts a beneficial effect on the peripheral neurological disease. The dosage administered, as single or multiple doses, to an individual will vary depending upon a variety of factors, including clusterin pharmacokinetic properties, the route of administration, patient conditions and characteristics (sex, age, body weight, health, size) , extent of symptoms, concurrent treatments, frequency of treatment and the effect desired.

Clusterin can preferably be used in an amount of about 0.001 to 10 mg/kg or about 0.01 to 5 mg/kg or body weight or about 0.1 to 3 mg/kg of body weight or about 0.1 to 0.2 mg/kg of body weight or about 1 to 2 mg/kg of body weight. Further preferred amounts of clusterin are amounts of about 0.1 to 1000 μg/kg of body weight or about 1 to 100 μg/kg of body weight or about 10 to 50 μg/kg of body weight.

The route of administration, which is preferred according to the invention, is administration by subcutaneous route. Intramuscular administration is further preferred according to the invention.

In further preferred embodiments, clusterin is administered daily or every other day. The daily doses are usually given in divided doses or in sustained release form effective to obtain the desired results. Second or subsequent administrations can be performed at a dosage which is the same, less than or greater than the initial or previous dose administered to the individual. A second or subsequent administration can be administered during or prior to onset of the disease.

According to the invention, clusterin can be administered pro- phylactically or therapeutically to an individual prior to, simultaneously or sequentially with other therapeutic regimens or agents (e. g. multiple drug regimens) , in a therapeutically ef- fective amount. Active agents that are administered simultaneously with other therapeutic agents can be administered in the same or different compositions .

Clusterin shares several features with sHsps (Humphreys et al., 1999) : (i) its expression is induced by heat shock due to a strictly conserved 14 bp DNA element in the promoter of the clusterin gene, recognized by the heat shock transcription factor HSFl (Michel et al., 1997), (ii) it is upregulated in several protein aggregation diseases, such as Alzheimer disease

(Choi-Miura and Oda, 1996; DeMattos et al., 2002; Matsubara et al., 1996) or bovine spongioform encephalopathy (BSE) (McHattie et al., 1999), (iii) the β-chain of clusterin has limited sequence similarity (around 25%) to the C-terminal domain of αB- crystallin (Carver et al., 2003), (iv) it possesses no ATPase activity (Poon et al., 2000), (v) it stabilizes misfolded proteins but does not have refolding specificity (Poon et al., 2002) , and (vi) it prevents aggregation of misfolded proteins

(Carver et al., 2003). However, sHsps and clusterin differ in two important points: (i) sHsps act intracellularly whereas the physiological chaperone-like function of clusterin has mainly been described extracellularly and, (ii) sHsps ύare activated by high temperatures, whereas sClu is activated by mildly acidic pH

(Carver et al., 2003; Humphreys et al., 1999; Michel et al., 1997; Poon et al., 2000; Poon et al., 2002; Wilson and Easter- brook-Smith 2000). Preferably, the ^MsHps features" (i)-(vi) and the "specific clusterin feature" (ii) (optionally also (i) ) , above are regarded as defining the activity of clusterin according to the present invention.

Compounds promoting or enhancing clusterin activity are e.g. the agonists of clusterin activity disclosed in WO 2004/084932 A and include molecules stimulating or mimicking clusterin activity, such as agonistic antibodies of a clusterin receptor, small molecular weight agonists activating signalling through a cluster- in receptor, enhancers of (endogeneous) clusterin expression. Also gene activation technology can be used to enhance expression of clusterin. ApoA-I, beta-amyloid peptide, complement components, gluthathione-S-transferase, gp330/megalin, heparin, im- munoglobulins, lipids, paraoxonase, prion peptide, SIC (streptococcal inhibitor of complement), S. aureus cell surface and TGF- beta receptor are reported clusterin binding ligands and can also be used for triggering clusterin activity TGF-β and IL-I were shown to induce clusterin expression. Furthermore heat shock factor 1 inducers or activators could be used as inducers of clusterin expression.

Due to the action of clusterin, which is not restricted to a specific misfolded or aggregated protein, the medical possibilities of the present invention relate to all such diseases or disorders . Positive effects of administration of clusterin or a compound promoting or enhancing clusterin activity was also surprising in view of the proposed link to progression of Alzheimer's disease (WO 02/22635 A;).

According to the present invention, such clusterin activity is used for biologically acting on elastic fibers in various circumstances intra- or extracellularly, especially for combatting pathological circumstances related to such elastic fibers .

Preferably, however, the disease or disorder to be treated or prevented by the present invention is selected from (i) age-associated and UV exposure-associated alterations of the skin, which lead to profound alterations of proteins in the extracellular space, including modified or deposited components of elastic fibers, all alterations of the skin, including age-related or UV-related, which are associated with the occurence of modified and/or deposited proteins in the extracellular space, including alterations or modifications of ^• components of elastic fibers, (ii) arteriosclerosis, which is associated with alterations of extracellular matrix components of arterial walls, (iii) lung diseases, especially emphysema, associated with a destruction of elastic fibers in alveolar septa or adult or infant respiratory distress syndrome (ARDS/IRDS) , where proteins and other components are deposited at the inner surface of alveoli and thereby prevent oxygen exchange, (iv) degenerative alterations of intervertebral discs and tendons, (v) liver fibrosis and cirrhosis, where connective tissue consisting of various extracellular matrix proteins including collagen, laminin and elastic fibers accumulate in the space of Disse, perivenular, pericellular or in fibrous septa, (vi) amyloidoses, where various abnormal proteins including serum amyloid A, β2-micro- globulin, immunoglobulins, hormones are deposited in the extracellular space, and (vii) neurodegenerative disorders, especially Prion diseases, where abnormal proteins such as PrP are disposed in the extracellular space.

The exact route of administration as well as the optimal dosages can be determined for each specific case, mainly based on the nature of the disease or disorder and on the stage of this disease. Preferably, the medicament according to the present invention is applied locally or systemically, in particular, intravenously, orally, parenterally, epicutaneously, subcutaneously, intrapulmonarily by inhalation or bronchoalveolar lavage, intra- muscularily, intracranially, locally into intervertebral discs or other connective tissues.

Specifically preferred embodiments of the present invention include that the medicament is applied locally for the prophylaxis or therapy of skin damages caused by UV radiation or ageing, the medicament is applied into the lung, preferably by lavage or inhalation for the prophylaxis or therapy of infant respiratory distress syndrome (IRDS) or adult respiratory distress syndrome (ARDS) , the medicament is applied locally for the prophylaxis or therapy of degenerative processes of intervertebral disks or tendons, the medicament is applied for the prevention of concrement formation in pancreas or bile ducts, the medicament is applied systemically for the reduction of degenerative damages of vessel walls in the course of arteriosclerosis, the medicament is applied systemically for the treatment of liver cirrhosis or fibrosis, especially for the reduction of degeneration of connective tissue, the medicament is applied systemically for treating amyloidoses, and the medicament is applied systemically for the treatment or prophylaxis of neurodegenerative diseases.

Preferably, the medicament according to the present invention is administered to the human patient in a dose of 0,001 to 10 mg/kg, preferably from 0.01 to 5 mg/kg, especially 0.1 to 0.2 mg/kg body weight .

The present invention is further illustrated by the following examples and drawing figures, yet without being restricted thereto .

Fig. 1 shows (A) a model of domain structure of human clusterin. The secreted full—length variant of clusterin is cleaved to generate the N-terminal α-chain and the C-terminal β-chain. The limited sequence homology (~25%) between β-chain of clusterin and C-terminal (α-crystallin) domain of αB-crystallin is marked. Predicted domains of clusterin: slashed boxes represent two coiled-coil α-helices; ovals indicate three amphipathic α- helices; nuclear localization signals are indicted by *; (B) Truncated clusterin lacks the 22-mer hydrophobic ER-targeting signal, which is replaced by an ATG start codon.

Fig. 2 tS'hows CHO-Kl cells cotransfected (Tf) with keratin 8, ubiquitin (Ubi) or clusterin (CIu) . Immunofluorescence (IF) microscopy was performed 24 hours after transfection. Constant colocalisation of ubiquitin with keratin aggregates (arrowhead in A) indicates that not properly assembled keratins are recognized as misfolded proteins. Clusterin (B) lacks affinity to keratin aggregates and was found in a reticular distribution. In contrast, a truncated variant of clusterin lacking the signal peptide (trClu) had very strong affinity and colocalized constantly with keratin aggregates (arrowheads in C) . Fig. 3 shows cellular localization of full-length clusterin (CIu) and a truncated variant of clusterin (trClu) , lacking the ER-targeting signal. CHO-Kl cells were cotransfected (Tf) with an expression construct encoding an ER-marker protein and either clusterin (CIu) or truncated clusterin (trClu) . Immunofluorescence (IF) microscopy was performed 24 hours after transfection. The reticular distribution of clusterin overlapped with the ER- marker. However, trClu was found in a diffuse pattern and showed no colocalisation with the ER-marker.

Fig. 4 shows iramunohistocheitiical staining (IHC) of alcoholic steatohepatitis (ASH) , αl-antitrypsin (αl-AT) deficiency and Alzheimer disease with antibodies to ubiquitin (Ubi) and clus- terin (CIu) . Arrowheads indicate different types of inclusions i.e. , Mallory bodies (MBs), αl-AT deposits and neurofibrillary tangles . MBs were constantly stained with antibodies to ubiquitin (A) , whereas staining with clusterin was negative (D) . Clusterin antibodies stained fibrotic tissue in the extracellular space (arrows in G) . Antibodies to ubiquitin and clusterin did not react with αl-AT (B, E) . Clusterin was detected in the extracellular space (arrows in H) . Neurofibrillary tangles were positive for ubiquitin (C) , but negative for clusterin (F) . Clusterin antibodies stained amyloid plaques (arrows in I) . Fig. 5 shows immunohistochemical staining (IHC) of aged and young human skin using antibodies to elastin and clusterin (CIu) . In aged skin clusterin colocalizes with deposits of degenerated elastic fibers (arrowheads in A, B) . No accumulation of clusterin was observed in young skin (C) whereas was detected in aged skin (arrowheads in D) .

Fig. 6 shows immunohistochemical staining (IHC) of normal and diseased tissues using antibodies to clusterin (CLUi)Ba. In normal blood vessels (aorta) clusterin is not detected (A) whereas clusterin accumulates in different layers of the wall of the aorta with arteriosclerosis (arrowheads in B) . In normal lung minor amounts of clusterin are present in the walls small blood vessels and in alveolar septa (C). In lungs with ARDS clusterin is present in hyaline membranes (arrow heads in D) .

EXAMPLES:

Materials and methods

Plasmid constructs

In order to clone the genes of interest, cDNA was produced by reverse transcription of total RNA (isolated from HeLa cells) and used as template for PCR. PCR was performed using 1.0 unit Platinum Taq DNA Polymerase High Fidelity (Invitrogen, Gronin- gen, The Netherlands) . Primers were selected to generate mycHis- tagged expression constructs of clusterin (accession number: M64722), truncated clusterin (trClu) . Restriction sites were introduced as indicated: Clu-Hindlll-fw 5'-GCA AGC TTC ATG ATG AAG ACT CTG CTG CTG-3' and Clu-XhoI-rev 5'-GCA CTC GAG CGC TCC TCC CGG TGC TTT TTG C-3' were used to amplify the coding region of clusterin. The forward primer tr-Clu-Hindlll-fw 5'-GCA AGC TTA TGG ACC AGA CGG TCT CAG ACA ATG-3' was constructed to produce trClu, a cytoplasmic variant of clusterin,. in which the endoplasmic reticulum-targeting hydrophobic leader peptide was replaced by an ATG start codon. The obtained fragments lacked the stop codons (for C-terminal mycHis tagging) and the two termini contained two different restriction sites to perform direct cloning. The fragments were purified, digested and cloned in- frame into pre-digested mammalian expression vectors (Invitro- gen) pcDNA4/myc-HisA (p62) , B (clusterin, trClu) . To generate an expression construct encoding human ubiquitin (accession number of polyubiquitin: M26880) including start and stop codon, the last ubiquitin genomic sequence was amplified by PCR using the pair of primers ϋbi-BamHI-fw (5'-TCG GAT CCA TGC AGA TCT TCG TGA AGA CC-3') and Ubi-Xbal-rv (5'-CCT CTA GAT TAG ACA AAA AAA ATA AAG CG-3' ) . The obtained fragment was purified, digested and cloned in-frame into the pue-digested mammalian expression vector pcDNA4/HisMaxC (Invitrogen) . To produce an EGFP-keratin 8 fusion protein, the coding region of human keratin 8 (accession number: BCO00654) was amplified using the primers hk8-EcoRI-fw 5 '-TCG AAT TCT ATG TCC ATC AGG GTG ACC CAG A-3' and hK8-BamHI-rv 5'-GTG GAT CCC TGC CGC AGC TGT TCA CTT G-3', which introduces the restriction site downstream the termination codon. All plas- mids generated were confirmed by DNA sequencing (performed by VBC Genomics sequencing service, Vienna, Austria) . Vectors pcD- NA3-mK8 and pcDNA3-mK18, encoding untagged mouse keratin 8 (accession number: NM_031170) and 18 (accession number: M11686) , were kindly provided by B. Klδsch and M. Schuller (Ludwig Boltzmann Institut, Vienna) . The recombinant plasmids ER DKFZ p564 B212 1E2Y1 and ER DKFZ p564 B212 1E2Y2, encoding both fluorescence-tagged endoplasmic reticulum membrane proteins (ER- marker proteins) were a generous gift from A. Poustka (DKFZ; Heidelberg; Germany; http://www.dkfz.de/mga/). All proteins were expressed under the control of a CMV promoter. Cell culture and transfection CHO-Kl cells (CCL-61, ATCC, Manas- sas, VA) were cultured in Ham's F-12 Nutrient mixture (Sigma- Aldrich, Steinheim, Germany), supplemented with 2.2 g/1 NaHCO₃ (Merck, Darmstadt, Germany) and 10% foetal calf serum (Sigma- Aldrich) in a 75 cm² vented culture flask (Costar, Wiesbaden, Germany) . IxIO⁵ CHO-Kl cells were seeded 24 hours before transfection onto glass coverslips (12 mm in diameter, Assistant Sondheim/Khόn, Germany) placed in 24-well plates (Costar) . Cells were transfected at 90-95% confluence with 0.75 μg endotoxin- free DNA using LipofectamineTM 2000 (Invitrogen) according to manufacturers instructions. After 3.5 hours the transfection mixture was replaced by normal culture medium and cells were grown for 20 hours. For proteasome inhibition, lactacystin (Boston Biochem, Cambridge, MA) was mixed with the normal growth medium to a final concentration of 5 μM. Transfections with empty vectors pcDNA4/myc-HisA, B, pcDNA4/HisMaxC, pcDNA3 or pEG- FP-Cl served as control. All transfections were performed at least in three independent series.

Indirect immunofluorescence microscopy

Transfected cells were washed with PBS (pH 7.25) and fixed at -20⁰C for 5 minutes in methanol and 5 seconds in acetone. Immun- ostaining was performed at room temperature in a light-protected humidified chamber. Fixed cells were incubated with primary antibodies for 30 minutes, washed in PBS and incubated with secondary antibodies at the same conditions . For dual labelling, this procedure was repeated. All antibodies were diluted in PBS as indicated. MycHis-tagged clusterin and trClu were identified with mouse anti-hisβ tag monoclonal antibody (Roche Diagnostics, Mannheim, Germany, 1:20), ubiquitin was detected via Xpress epitope with mouse anti-Xpress monoclonal antibody (Invitrogen, 1:500) and mouse keratins were detected using rabbit anti-keratin 8 and 18 polyclonal antibody (50K160, produced in the present laboratory, Hutter et al., 1993, 1:50). The secondary antibodies used were Cy3 anti-mouse (Amersham Biosciences, Pis- cataway, NJ 1:2000) and fluorescein isothiocyanate (FITC) -conjugated anti-rabbit Ig (Dako, Glostrup, Denmark, 1:50). Immuno- fluorescent specimens were washed in PBS, followed by H₂O and ethanol, dried and mounted in Mowiol (Calbiochem, San Diego, CA; Nr. 475904) . Cells were viewed and photographed using a laser scanning microscope (LSM510, Zeiss, Oberkochen, Germany) . Controls were included by replacing primary antibodies with PBS as well as by transfecting empty plasmids .

Human tissues

Formaldehyde-fixed and paraffin-embedded human tissue samples were obtained from the Biobank of the Institute of Pathology (Medical University of Graz, Austria) . Six patients with histological confirmed ASH, seven patients with αl-AT deficiency, four cases with advanced Alzheimer disease, four cases of aged skin (65-67 years), three cases of young skin (12-19 years), five cases of patients with elastofibroma, one normal aorta and four cases of atherosclerotic aorta and two samples of lung tissue and one lung with adult respiratory distress syndrome were selected.

Immunohistochemistry

The following primary antibodies were diluted with Dako diluent (Dako) and used at the indicated dilutions: rabbit polyclonal anti-clusterin-α/β antibody, H-330 (Santa Cruz Biotechnology, CA, 1:100); polyclonal rabbit antibody to ubiquitin (Dako, 1:200); keratins were detected using an equimolar mixture of monoclonal mouse antibodies to keratin 8 and keratin 18 (Neo- Markers, CA, 1:50); polyclonal rabbit antibody to αl-AT (BioGen- ex Laboratories, San Ramon, CA, 1:10); monoclonal rabbit antibodies to collagens type 1 and 3, respectively (both from San- bio, AM Uden, The Netherlands, 1:20); mouse anti-β amyloid monoclonal antibody (Novocastra Laboratories, Newcastle, UK, 1:25); monoclonal mouse antibody to elastin (Sigma, 1:10). P62CT antibody binding was detected with the rabbit anti guinea pig HRP- conjugated immunoglobulins and the TSATM detection system (NEN, Boston, MA, USA) . Binding of all other antibodies was detected with Multi Link biotinylated swine anti goat, mouse, rabbit immunoglobulins and Strept ABComplex/HRP (Dako) . HRP was visualized using AEC as substrate (Dako) . For immunohistochemistry, 4 um thick paraffin sections of formaldehyde-fixed material were deparaffinized and rehydrated. Antigen retrieval was performed either by treatment with 0.1% protease (type XXIV; Sigma) in PBS for 10 minutes (for ubiquitin, collagen type 1 and 3) , or by treatment with 0.1% trypsin in TBS with 0.1% CaC12 at 37⁰C for 15 minutes (for elastin) , or microwaved in 0.01 mol/L citrate buffer, pH 6.0 (for clusterin and Hsp27), or pH 7.3 (for keratin 8/18) , at 750 W for 10 minutes, or by treatment with formic acid for 3 minutes (for β-amyloid) . Endogenous peroxidase was blocked by incubation with 1% H₂O₂ in methanol for 10 minutes. Incubation with primary antibodies for one hour (two hours for anti-elast- in) at room temperature was followed by washing and incubation with the second antibody. Sections were mounted with AquatexR Merck) . Negative controls were performed by omitting the primary antibody. In addition, sections were also stained with Victoria blue to visualize elastic fibers using standard histological protocols (Scheuer and Lefkowitch, 2000) .

Results

Interaction of ubiquitin and clusterin with keratin aggregates in vitro

To investigate the interaction of clusterin with aggregated keratins in comparison with other stress proteins, a series of transfection studies utilising gene expression constructs encoding¹ clusterin, ubiquitin, keratin 8 and keratinrclδ were performed. The cellular distribution of these constructs was examined after transfection of CHO-Kl cells . After single transfection, ubiquitin was found in a fine-granular cytoplasmic distribution, with sporadic small aggregates . Furthermore, ubiquitin was present in the nuclei of the cells, sparing the nucleoli. Full-length clusterin appeared in a distinct cytoplasmic reticular distribution with perinuclear accentuation, reflecting the distribution of the endoplasmic reticulum (see below) . To elucidate the interaction of the stress proteins with keratin aggregates, CHO-Kl cells were cotransfected with vectors encoding various stress proteins and either untagged keratin 8 or EGFP-fused keratin 8, which produced larger aggregates. CHO-Kl cells lack endogenous keratin and overexpression of keratin 8 (in the absence of keratin 18) leads to cytoplasmic aggregates, whereas intermediate filaments are formed by cotransfection of keratin 8 and keratin 18. Cotransfection of ubiquitin with keratin 8 or EGFP-fused keratin 8 resulted in an almost complete colocalisation of ubiquitin and keratin aggregates (Fig. 2A) . Even small keratin deposits were ubiquitin positive (arrowhead in Fig 2A) , indicating that aggregated keratins are recognized as misfolded proteins, and marked for degradation by polyubi- quitination. Cotransfection of clusterin with keratin 8 did not lead to an association of clusterin with keratin aggregates, but resulted in a reticular distribution of clusterin (Fig. 2D) , identical to that seen in the single transfection experiment. This reticular distribution of clusterin was reminiscent of the structure of the ER. The restriction of clusterin to the ER without access to cytosolic proteins was proved by cotransfection of clusterin with two different vectors encoding ER-marker proteins (Fig. 3A) . To investigate possible binding properties of clusterin to misfolded cytoplasmic proteins, a truncated variant of clusterin (trClu) was generated, lacking the ER targeting hydrophobic signal peptide (schematic representation in Fig. IB) . In contrast to full-length clusterin, trClu was retained in the cytoplasm, as confirmed by cotransfection with ER- marker proteins (Fig. 3B) . Single transfection of trClu resulted in a fine-granular cytoplasmic distribution and formation of small aggregates. However, cotransfection of trClu with keratin 8 resulted in an almost complete colocalisation with keratin aggregates (Fig. 2E) . To demonstrate, whether the interaction of trClu with keratin was specific for misfolded keratin, trClu was also cotransfected in the presence of regular keratin intermediate filaments, produced by cotransfection with keratin 8 and 18. In this situation, no binding of trClu to keratin intermediate filaments was observed, showing that affinity of trClu is restricted to misfolded proteins. In addition, these results indicate that the signal peptide efficiently directs full-length clusterin into the ER preventing, at least under the present experimental conditions, interaction of clusterin with abnormal cytoplasmic proteins .

Presence of clusterin in human protein aggregation diseases

To investigate the presence of clusterin in protein aggregates in human diseases, immunohistochemical studies were performed on liver tissues of patients with ASH and of patients with αl-AT deficiency, brain tissues of patients with Alzheimer disease, young and aged skin tissues, normal and skleortic arteries, and human lung tissue samples with ARDS. Liver sections of six cases of ASH were immunostained using antibodies to clusterin. Antibodies to clusterin did not stain (intracellular) MBs (Fig. 4D) , however MBs, which were found in an extracellular position due to cell lyses were strongly positive. Furthermore, immunoreac- tion of clusterin was highly positive in the extracellular matrix in fibrotic liver tissue (Fig. 4E) . This reaction was prominent in portal fields and in fibrous septa as well as in the muscle layer of blood vessels. To further characterize the protein association of clusterin in the fibrotic tissue, immunos- taining was performed with antibodies to collagens type 1 and type 3, respectively. These antibodies revealed a clear difference in the distribution of clusterin and collagen. However, Victoria blue staining revealed that clusterin matched the distribution of elastic fibers. Since transfection studies revealed that clusterin was efficiently transported into the endoplasmic reticulum (ER) , it was examined whether clusterin bound to accumulated abnormal proteins in the ER lumen. Therefore immunohis- tochemical studies of liver tissue from patients with αl-AT deficiency, which is characterized by accumulation of abnormally folded αl-AT in the ER of the hepatocytes were performed. Seven cases of αl-AT deficiency were investigated using antibodies to clusterin. Interestingly, clusterin was not detectable in αl-AT aggregates (Fig. 41) . Clusterin immunoreactivity in the extracellular matrix (Fig. 4J) resembled that observed in ASH.

Immunohistochemical investigation of brains of Alzheimer disease patients allowed to study the presence of clusterin and other stress proteins in intracellular (neurofibrillary tangles) as well as extracellular (amyloid plaques and cerebral amyloid angiopathy) protein deposits in the same tissue sample. Immunohis- tochemistry was performed on four cases of advanced Alzheimer disease with antibodies to clusterin. Small granules of cluster- in were found in many neural cells, but neurofibrillary tangles were negative (Fig. 4N) . This granular cytoplasmic reaction of clusterin has been described previously (Giannakopoulos et al., 1998) and was found preferentially in proximity of amyloid plaques and clusterin positive blood vessels. All four cases of Alzheimer disease showed strong immunoreactivity of clusterin to extracellular amyloid plaques (Fig. 40) and blood vessels.

Discussion

Studies of the cellular response to misfolded and aggregated proteins are essential for better insight into the biological basis of so called protein aggregation diseases . In the present invention it was shown that a novel candidate being involved in the response to misfolded proteins is clusterin. It has been reported that clusterin has chaperone-like activity to stabilize misfolded proteins in a folding-competent state (Poon et al . , 2000) , similar to sHsps . In contrast to sHsps, however, it acts predominantly in the extracellular space (Carver et al., 2003). Since clusterin was also found in the cytoplasm (Jones and Jomary, 2002; Debure et al., 2003) a possible interaction of clusterin with misfolded and aggregated keratin was explored. Full-length clusterin does not colocalize with keratin aggregates in cell culture, because it is efficiently targeted to the ER to be secreted. However, a deletion mutant of clusterin lacking the ER-targeting signal (trClu) did colocalize completely with cytoplasmic keratin aggregates, indicating that clusterin has strong affinity to misfolded proteins. Furthermore, cluster- in was not detestable in cytoplasmic MBs in ASH, but was positive in MBs, which were found in an extracellular position due to cell lyses . Clusterin was also not detectable in cytoplasmic neurofibrillary tangles in Alzheimer disease. These data provide strong evidence that a cytoplasmic chaperone activity of full- length clusterin is of no biological relevance under physiologic and pathologic conditions .

Since clusterin is transported to the ER the chaperone-activity of clusterin in this compartment was studied. αl-AT deficiency served as model to investigate the interaction of clusterin with mutated αl-AT, which accumulates in the ER. However, in immuno- histochemical studies, an association of clusterin with αl-AT inclusions was not found. Since it has been reported that mutated αl-AT undergoes a loop-sheet polymerisation, in which the reactive center loop of one molecule inserts itself into a β-sheet of an adjacent molecule (Kopito and Ron, 2000), it is possible, that clusterin does not recognize αl-AT-polymers as misfolded proteins due to the lack of exposed hydrophobic domains.

Surprisingly, a strong reaction of clusterin antibodies with extracellular matrix components was found in the portal fields and fibrous septa in chronic liver diseases, including ASH and αl-AT deficiency. To identify the binding partner of clusterin, immun- ohistochemical studies were performed with antibodies to colla- gens type 1 and 3, the major extracellular matrix components in liver. The present analyses revealed no interaction of clusterin with collagen. However, an association of clusterin with elastic fibers was found. In this context it is interesting, that elast- in has highly hydrophobic domains, which play a role in the assembly of elastic fibers. Whether the association of clusterin with elastic fibers is a consequence of the high hydrophobicity of elastin or indicates that misfolding of elastin is a yet unrecognized mechanism involved in the pathogenesis of liver fibrosis remains to be elucidated. A role of clusterin in the response to extracellular misfolded proteins is also supported by the observation that clusterin is constantly present in amyloid plaques in Alzheimer disease (this study and Calero et al., 2000) .

(S3 ©3

There is evidence that similar mechanisms are involved in the cellular response to misfolded proteins in the cytoplasm, the ER, and the extracellular space.

Various components of the stress response system have been identified in the extracellular space as well as on the cell surface. For example, recent reports describe the presence of pro- teasomes in the plasma membrane of sperm heads (Morales et al., 2004; Sakai et al., 2004). A secreted homologue of ubiquitin, ISG15 has been identified as an interferon-induced cytokine (D'Cunha et al., 1996). Furthermore, the cytoplasmic molecular chaperone Hsp90 is secreted by cancer cells to promote migration by assisting extracellular maturation of metalloprotease MMP2, which are required for invasion (Picard, 2004) . However, it is still unclear how organisms deal with misfolded and aggregated proteins in the extracellular space. So far clusterin is the first and only well characterized mainly extracellular chaper- one. Clusterin may, on the one hand, preserve misfolded proteins in a folding competent state and, on the other hand, mediate en- docytosis and degradation of proteins by the megalin/gp330 receptor (Kounnas et al., 1995; Jones and Jomary, 2002).

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Claims

Claims :

1. : Use of a compound with clusterin activity or a compound promoting or enhancing clusterin activity for the preparation of a medicament for treatment or prevention of diseases which are associated with modification of proteins or deposition of abnormal proteins .

2.: Use according to claim 1, characterized in that the disease is selected from (i) age-associated and UV exposure-associated alterations of the skin, which lead to profound alterations of proteins in the extracellular space, including modified or deposited components of elastic fibers, all alterations of the skin, including age-related or UV-related, which are associated with the occurence of modified and/or deposited proteins in the extracellular space, including alterations or modifications of components of elastic fibers, (ii) arteriosklerosis, which is associated with alterations of extracellular matrix components of arterial walls, (iii) lung diseases, especially emphysema, associated with a destruction of elastic fibers in alveolar septa or adult or infant respiratory distress syndrome (ARDS/IRDS) , where proteins and other components are deposited at the inner surface Of alveoli and thereby prevent oxygen exchange, (iv) degenerative alterations of intervertebral discs and tendons, (v) liver fibrosis and cirrhosis, where connective tissue consisting of various extracellular matrix proteins including collagen, laminin and elastic fibers accumulate in the space of Disse, perivenular, pericellular or in fibrous septa, (vi) amyloidoses, where various abnormal proteins including serum amyloid A, β2-microglobulin, immunoglobulins, hormones are deposited in the extracellular space, and (vii) neurodegenerative disorders, especially Prion diseases, where abnormal proteins such as PrP are disposed in the extracellular space.

3. : Use according to claim 1 or 2, characterized in that the medicament is applied locally, intrapulmonarily, systemically, intravenously, orally, parenterally, subcutaneously, intramuscu- larily or intracranially.

4.: Use according to any one of claim 1 to 3, characterized in that the medicament is applied locally for the prophylaxis or therapy of skin damages caused by UV radiation or ageing.

5.: Use according to any one of claim 1 to 3, characterized in that the medicament is applied into the lung for the prophylaxis or therapy of infant respiratory distress syndrome (IRDS) or adult respiratory distress syndrome (ARDS) .

6.: Use according to any one of claim 1 to 3, characterized in that the medicament is applied locally for the prophylaxis or therapy of degenerative processes of intervertebral disks or tendons .

7.: Use according to any one of claim 1 to 3, characterized in that the medicament is applied for the prevention of concrement formation in pancreas or bile ducts .

8.: Use according to any one of claim 1 to 3, characterized in that the medicament is applied systemically for the reduction of degenerative damages of vessel walls in the course of arteriosclerosis .

9.: Use according to any one of claim 1 to 3, characterized in that the medicament is applied systemically for the treatment of liver cirrhosis or fibrosis, especially for the reduction of degeneration of connective tissue.

10.: Use according to any one of claim 1 to 3, characterized in that the medicament is applied systemically for treating amyl- oidoses.

11.: Use according to any one of claim 1 to 3, characterized in that the medicament is applied systemically for the treatment or prophylaxis of neurodegenerative diseases .

12.: Use according to any one of claim 1 to 11, characterized in that the medicament is applied in a dose of 0.001 to 10 mg/kg, preferably from 0.01 to 5 mg/kg, especially 0.1 to 0.2 mg/kg body weight.

13.: Use according to any one of claims 1 to 12, characterized in that the disease is associated with modification of proteins or deposition of abnormal proteins in the extracellular space.