EP1180037A2

EP1180037A2 - Therapeutic uses of agents that modulate the activity of alpha-smooth muscle actin

Info

Publication number: EP1180037A2
Application number: EP00937734A
Authority: EP
Inventors: Brigham And Women's Hospital The
Original assignee: Brigham and Womens Hospital Inc
Current assignee: Brigham and Womens Hospital Inc
Priority date: 1999-05-26
Filing date: 2000-05-25
Publication date: 2002-02-20
Also published as: WO2000071148A2; JP2003500113A; CA2374301A1; WO2000071148A3; JP2004167270A

Abstract

The present invention is directed to therapeutic methods that are based upon an ability to modulate cellular contraction. This is accomplished by administering agents that either inhibit or induce the activity of alpha-smooth muscle actin.

Description

Therapeutic Uses of Agents That Modulate the Activity of Alpha-Smooth Muscle Actin

Field of the Invention

The piesent invention is directed to methods for controlling cellulai contraction and to medical treatments that rely upon this conti ol The methods are important in the treatment of ligament damage, osteopoiosis, wound healing, tissue engineering, drug delivery, and the pievention of tumor cell metastasis

Background of the Invention

Cellular conti action plays a i ole m a numbei of biological activities that have therapeutic consequences The contraction of fibroblasts, gi own on a matrix in vitro as part of a tissue engineering piotocol for leplacing a damaged ligament, may altei the size, shape, and poiosity of the matnx and thereby jeopardize the peiformance of the implant In vivo, mappiopπate contraction may make the reattachment of the ends of a ruptured ligament to each other or to bone difficult or limit the movement of limbs as a result of excessive contracture This scenario also applies to other musculoskeletal tissue cells and to epithelial cells such as endothehal cells

Cellulai contraction also plays an important 1 ole in wound healing Although contraction may initially piomote healing, it can also lead to significant scarring and a loss of physiological function (see U S 5,741,777) The adverse effects of contraction are particularly severe in surgical and burn patients In addition, scarring may cause secondary damage to patients that have incurred damage to the spmal cord oi othei sevei e trauma

Other biological activities believed to depend, m part, on cellular contraction include osteoporosis (whei e the contraction of osteoblasts results m their retraction, thus allowing bone resorption to proceed) and in tumor cell metastasis In the latter case, cancer cells must typically pass an endothehal cell barrier befoie they can entei into the bloodstream and be earned to a distant site foi colonization Agents that prevent endothehal cells from contracting (and thereby retracting) should therefore make metastasis moi e difficult

In addition to its impoitance in ligament repair, tissue engineering, wound healing, osteoporosis and metastasis, the ability to control cell contraction may lead to improved procedures for diug delivery For example, an agent that promoted endothehal cell contraction might be include in mtranasal oi lntramusculai vehicles to aid m the passage of drug through the walls of capillaries Such agents may also aid substances already in the bloodstream in exiting mto tissue

Alpha smooth muscle actm (SMA)ιs a particular isoform of actm that may cause the contraction of vascular smooth muscle cells (Saga, et al , Exp Cell Res 249 279-292 ( 1999)) It is known to be expressed m myofibroblasts during wound healing and in tissues undergoing fibrosis (Zhang, et al , Am J Pathol 148 527-537 (1996), Jestei, et al , Opthal Vis Sci 36 809-819 (1995), Darby, et al , Lab Invest 63 21-28 (1990)) The complete nucleotide and ammo acid sequences of the human form of the gene have been i eported (Herrman, Curr Opin

Cell Bwl 5 48-55 (1993))

Summary of the Invention

The present invention is based upon the discovery that SMA is responsible for the contraction of a variety of cells other than fibroblasts and for which such activity was not previously known Agents that inhibit SMA activity prevent these cells from contracting, whereas agents that induce

SMA activity promote conti action Examples of SMA inhibitors include platelet derived growth factor (PDGF), staurosporm and mterferons An example of an SMA inducer is transforming growth factoι-β (TGF-β)

In its first aspect, the piesent invention is directed to methods of repairing musculoskeletal tissue (including bone, articulai cartilage, meniscus, tendon mtervertebral disk and especially damaged ligaments), and epithelial tissue One procedure foi accomplishing this involves removing cells from a patient's body, growing them on a matrix, and then implanting the matrix/cell combination at the site of the damage, e g at the site of atom ligament This approach has been referred to as "tissue engineering " The cells used may be any of the musculoskeletal, or epithelial cells mentioned above Alternatively, marrow stromal stem cells may be used and have the advantage of being relatively easy to obtain Matnces may be made out of several different types of biologically compatible material, but type I collagen and synthetic polymers, such as polylactic acid and polyglycohc acid, will typically be employed The invention is directed to an improvement in this procedure in which cells grown on matnces in vitro are treated with a concentration of an agent sufficient to either inhibit or promote the expression or biological action of alpha-smooth muscle actin (SMA). Among the agents that may be used for inhibiting contraction are PDGF and interferon. The activity of SMA may also be reduced by preventing its expression using an antisense oligonucleotide, particularly an oligonucleotide complementary to the promoter region of the human SMA gene. Among the agents that may be used to promote contraction is TGF-β.

The invention is also directed to a method of treating a patient for damaged musculoskeletal tissue (particularly a damaged ligament) or epithelial tissue by sequentially administering, at the site of injury, an SMA inhibitor followed by an SMA inducer. The inhibitor should be given at a dosage and for a duration sufficient to promote tissue attachment. The time necessary for attachment to occur will vary from patient to patient, but will typically be between 1 and 10 weeks . The extent to which attachment has occurred may be determined by clinical examination and by diagnostic imaging techniques well known in the art. After attachment, the inducer should be administered for the purpose of causing the tissue to contract and thereby assume a more natural conformation. One example of a treatment protocol using this procedure would involve injections of TGF-beta at a concentration of between 100 ng/ml and 500 ug/ml at the site of ligament damage, e.g., the knee. After a period of, for example, 4 weeks, injections are made using a comparable concentration of PDGF or an interferon until healing is complete.

In another aspect, the invention is directed to a procedure for promoting the healing of wounded musculoskeletal tissue in a patient. Initially, an SMA inducer (TGF-beta,

100 ng/ml-500 ug/ml) is injected at the site of tissue damage at a dosage and for a duration sufficient to promote the closure of the wound. Once closure has been essentially completed, an SMA inhibitor (e.g., PDGF or an interferon in the concentration ranges recited above) may be administered at the site of the wound to reduce scar formation. In most cases, it is expected that administration will be accomplished using local delivery.

Inducers of SMA may also be administered to a patient for the purpose of enhancing drug absorption. A sufficient dosage should be given to induce endothehal cell contraction. For example, TGF-β at a concentration of 100 ng/ml - 500ug/ml can be co-administered with a second drug either parenterally or intranasally. The invention is also directed to a method of preventing tumor cell metastasis in a cancer patient. This may be accomplished by administering an agent that inhibits SMA in the endothehal cells of the vasculature. Because the endothehal cells do not contract, cancer cells shed from a main tumor mass is prevented from entering into the patient's bloodstream and those in the bloodstream are prevented from invading tissue.

Detailed Description of the Invention Treatment Methods

The ability to control the contraction of cells has important consequences with respect to at least six different therapeutic applications. First, it is important with respect to ligament repair procedures involving in vitro tissue engineering methods. Scientific articles describing such procedures include: Amoczky, et al., J. B one Joint Surg. 70A: 1209-1217 (1988); Milachowski, et. Al.Jnt. Orthop. 73: 1-11 (1989); Arnoczky, etal, Clin. Orthop. 252: 121-128 (1990); Siegel, et al. , Clin. Sports Med. 12: 59-80 ( 1993); Stone, et al. , Am. J. Sports Med. 20: 104- 1 11 ( 1992); Toyonaga, et al. , Clin. Orthop. 179:291 -297 ( 1983), Klompmaker, et al. , Biomaterials 72:810- 816 (1991); Stone, etal.,J. Bone Joint Surg. 79.4: 1770-1777 (1997); Stone, etal, Clin. Orthop.

252: 129-135 (1990); Nehrer, et al, Biomaterials 75768-776 (1997). Replacement ligaments may be prepared by removing cells from a patient's body and growing them on matrices containing collagen and similar materials. The contraction of the cells in vitro creates matrix distortions that complicate this procedure. It has now been discovered that agents modulating the activity of alpha-smooth muscle actin can be used to control cell contraction. The invention is compatible with any method of growing cells in vitro and involves simply adding an inhibitory agent to growth medium and/or to the matrix prior to the seeding of cells. For example, PDGF may be added to DMEM culture medium used for the growth of fibroblasts on a collagen/ glycosaminoglycan matrix. The concentration of PDGF should generally be between 1 and 500 ng/ml and preferably between 10 and 50 ng/ml. This therapeutic approach to the treatment of ligament injuries also applies in the same way to injuries in bone, articular cartilage, meniscus, tendon, mtervertebral disk, and for liver or other epithelial tissue engineering.

In vivo, inappropriate cellular contraction may make it difficult for natural or implanted ligaments to attach to bone properly and may restrict movement after attachment has been accomplished. In order to avoid these problems, an SMA inhibitor (e.g., a pharmaceutical preparation of PDGF at a concentration of between 100 ng/ml and 500 ug/ml) may be injected directly at the site of ligament damage to promote attachment . Administration should be repeated on a regular basis, e.g., twice a week, until standard clinical procedures and imaging techniques indicate that attachment is complete. An inducer of SMA may then be injected at the site of injury to cause the ligament to contract and thereby assume a more normal conformation. For example,

TGF-β may be injected at a concentration of between 100 ng/ml and 500 ug/ml. As with the injections of the SMA inhibitor, the injections of inducer should be performed on a regular basis with results followed by periodic clinical evaluation. As with the in vitro methods discussed above, the in vivo procedures used for damaged ligaments can be applied in exactly the same way to the repair of bone, articular cartilage, meniscus, tendon and mtervertebral disk.

Cellulai- contraction also plays an important role in wound repair (see, e.g., Mast, in Wound Healing: Biochemical and Clinical Aspects, Cohen et al, ed., WB Saunders Co. (1992)). Myo fibroblasts expressing alpha-smooth muscle actin pull together the open margins of skin wounds to promote healing (Eddy et al, Am. J. Pathol 130:252-260 (1988); Welch et al, J. Cell. Biol 70: 133-145 (1990)) . In order to further promote contraction, an inducer of SMA may be administered at the wound site. For example, TGF-beta may be administered in a topical preparation at a concentration of between 100 ng/ml and 500 ug/ml. The preparation should be changed periodically over a period of days until wound closure has been accomplished. To reduce scarring, a preparation containing one or more inhibitors of alpha-smooth muscle actin should then be administered either topically or by local injection. For example, a preparation containing PDGF at a concentration of between 100 ng/ml and 500 ug/ml may be injected. Injections should be repeated periodically until healing has been completed.

The expression and activity of alpha-smooth muscle actin in endothehal cells may be used to enhance drug delivery. Specifically, inducers of SMA may be used to promote the contraction of endothehal cells, thereby making it easier for drug to be absorbed into the vasculature of a patient. Thus, an agent such as TGF-β may be combined with a drug injected intramuscularly to aid in its absorption. Alternatively, an SMA inducer may be included in intranasal drug compositions to promote the absorption of therapeutic agents into the capillaries of the lung. In the case of TGF-β, it is expected that a concentration in the range of 100 ng/ml- 500 ug/ml would be used in preparations. Agents that inhibit endothehal cell contraction (e.g. PDGF) will make both the entry and exit of cells from a patient's bloodstream more difficult. Since one of the major events that must take place for tumor cell metastasis to occur is for cells to pass into and out of blood vessels, SMA inhibitors may be used as a treatment for patients with solid tumors. An inhibitor may be injected either systemically or it may be administered directly at the site of tumor occurrence. Topical preparations of inhibitor may also prove useful in certain instances, e.g. in the treatment of various types of skin cancer.

Agents inhibiting alpha-smooth muscle actin may also be used as a therapy for patients with osteoporosis. Systemic injections of agents such as PDGF or an interferon may be used to inhibit osteoblast retraction and thereby block osteoclast access to the bone surface for the purpose of calcium resorption. It is expected that this treatment will be used in conjunction with other established methods of treating osteoporosis involving the administration of agents such as calcium, vitamin D and parathyroid hormone. When PDGF or interferon is used as the inhibitor, it is expected that they will typically be injected in a pharmaceutical composition in a concentration range of between 100 ng/ml and 500 ug/ml. Sustained release preparations are also appropriate for the treatment of osteoporosis patients and may be more convenient for patients than repeated parenteral administration.

Dosage

The total dosage of alpha-smooth muscle inhibitor or inducer administered to a patient will be determined based upon the particular condition being treated, the route of administration and the treatment of objective. A typical daily dose of inhibitor or inducer administered to a patient will, depending upon the agent used, be between 1 ug and 10 mg. Topical, intranasal and locally injected preparations will, typically, also fall within this range. These dosages are simply guidelines and the actual dosage selected for an individual patient will be determined by the attending physician based upon clinical conditions and using methods well known in the art.

Agents may be provided in either a single or multiple dosage regimen and may be given either alone or in conjunction with other therapeutic agents. Dosage Forms and Route of Administration

The present invention is compatible with any 1 oute of administration and any dosage form Depending upon the particular condition being treated, certain dosage forms will tend to be more convenient or more effective than others For example, local injection will be the prefened route of administration for accomplishing in vivo ligament repair whereas topical admmistration will generally be preferred in treating skm cancers Apart from parenteral and topical preparations, agents may be administered orally, perorally, internally, mtra nasally, rectally, vaginally, lmgually, and transdermally Specific dosage forms include tablets, pills, capsules, powders, aerosols, suppositones, skm patches, parenterals and oral liquids including suspensions, solutions and emulsions Sustained release dosage forms may also be used All dosage forms may be prepared usmg metho ds that are standard mthe art (see e g , Remington's Pharmaceutical Sciences, 16th, Ed A Oslo Editoi, Easton, PA (1980)

Inhibitors and mducers of alpha-smooth muscle actm may be used m conjunction with any of the vehicles and excipients commonly employed in pharmaceutical preparations, e g , talc, gum arable, lactose, starch, magnesium sterate, cocoa butter, aqueous or non-aqueous solvents, oils, paraffin derivatives, glycols, etc Coloring and flavonng agents may also be added to preparations, particulaily those for oral admmistration Solutions can be prepared usmg water or physiologically compatible organic solvents such as ethanol, 1 ,2-propylene glycol, polyglycols, dimethyl sulfoxide, fatty alcohols, tnglycendes, partial esters of glycerine and the like Parenteial compositions may be used foi intravenous, mtraartenal, intramuscular, intraperitoneal, mti acutaneous or subcutaneous delivery These pi eparations can be made usmg conventional techniques and may include stenle lsotomc salme, water, 1 ,3-butanedιol, ethanol, 1 ,2-propylene glycol, polyglycols mixed with watei , Ringers' solution, etc

Inhibitors and mducers of cell contraction can also be used m conjunction with matnces employed as implants to facilitate tissue healing and as scaffolds to be seeded with cells in vitro for subsequent implantation In these cases, the inhibitors and inducers can be adsorbed by the matrix and, some cases, chemically coupled to the matnx Advantages of Treatment Methods

The ability to control cell contraction has not been widely exploited as a therapeutic strategy Thus, the methods discussed herein may serve to complement already established procedures Because the expression and action of alpha-smooth muscle actin has been found to be responsible for the contraction of many different cell types and because contraction is important to many diverse biological processes, a single set of inhibitory or inducing agents may contribute to several treatment regimens

Examples

Many types of injuries to the meniscus of the knee joint result in defects that do not heal, leading to pain and dysfunction Several types of porous absorbable matnces may be used alone or seeded with cultured cells to facilitate regeneration of this tissue The objective of the present study was to evaluate the in vitro contractile behavior of meniscal cells seeded in type I and type II collagen matrices

In many connective tissues, fibroblasts that have assumed a contractile phenotype (myofibroblasts) have been found to play an important role in healing and in pathological conditions This phenotype, if expressed in meniscal cells, may affect their behavior in cells seeded matrices developed for tissue engineering In the present study, the presence of a contractile actin isoform, alpha-smooth muscle (alpha-SM actin), was assessed by immunohistochemistry in normal calf meniscal tissue and in meniscal cells in 2- and 3 -dimensional culture

Calf meniscus cells were seeded in type I and type II collagen-glycosaminoglycan (GAG) matrices The diameter of the matrices was measured every two-three days Immunohistochemical staining of the 2-dimensional cultures for alpha-SM actin was performed after 1, 3, and 7 days, and of the seeded matrices at 1 , 7, 14, and 21 days Transmission electron microscopy (TEM) was performed on selected samples

After three weeks, the seeded type I matrices displayed a significant shrinkage of almost 50%, whereas the type II matnx and both types of unseeded controls showed almost no contraction over the same time period Positive staining for the alpha-SM actin phenotype was seen in 10% of the cells of the normal tissue, but was present in all cells seeded in mono layer and in both types of matrices TEM of representative cell-seeded matrices showed microfilaments approximately 7 nm bic, consistent with the myofibroblast phenotype To our knowledge, there are no other reports of alpha-SM actin-containing cells in the intact knee meniscus The finding that, under certain conditions, meniscal cells can express the myofibroblast phenotype suggests a role in meniscal healing and the tissue response to implants to facilitate tissue regeneration.

All references cited are fully incorporated by reference Having now fully described the invention, it will be understood by those of skill in the art that the invention may be performed within a wide and equivalent range of conditions, parameters and the like, without affecting the spirit or scope of the invention or any embodiment thereof.

Claims

What is Claimed is:

1. In a method of repairing damaged musculoskeletal tissue in a patient, comprising: removing musculoskeletal cells or marrow stromal stem cells from said patient; growing said cells on a matrix; and implanting the matrix/cell combination at the site of said damaged musculoskeletal tissue; the improvement comprising: contacting said cells in vitro with a concentration of an agent sufficient to either inhibit or promote the expression or biological action of alpha-smooth muscle actin (SMA).

2. In a method of repairing damaged epithelial tissue in a patient, comprising: removing epithelial cells or marrow stromal stem cells from said patient; growing said cells on a matrix; and implanting the matrix/cell combination at the site of said damaged epithelial tissue; the improvement comprising: contactmg said cells in vitro with a concentration of an agent sufficient to either inhibit or promote the expression or biological action of alpha-smooth muscle actin (SMA).

3. The method of either claim 1 or claim 2, wherein said agent is PDGF or an interferon.

4. The method of claim 1 wherein said damaged musculoskeletal tissue is a damaged ligament.

5. A method of treating a patient for damaged musculoskeletal tissue or damaged epithelial tissue comprising:

(a) administering an SMA inhibitor at the site of said damaged musculoskeletal tissue or epithelial tissue, said inhibitor being administered at a dosage and for a duration sufficient to promote the reattachment of torn ends of said tissue or the attachment of said tissue to bone; and

(b) administering an SMA inducer at the site of said damaged musculoskeletal tissue or epithelial tissue, said inducer being administered at a dosage and for a duration sufficient to promote the contraction of the reattached or attached tissue of step (a).

6. The method of claim 5, wherein said damaged musculoskeletal tissue or epithelial tissue is a damaged ligament.

7 The method of either claim 5 or claim 6, wherem said SMA mducer is TGF-β

8 The method of either claim 5 or claim 6, wherem said SMA inhibitor is selected from the group consisting of PDGF and an mterferon

9 A method of promoting musculoskeletal wound healmg m a patient, compnsmg

(a) administering an SMA mducer at the site of said wound at a dosage and for a duration sufficient to promote the closure of said wound, and

(b) admmistenng an SMA inhibitor at the site of said wound at a dosage and for a duration sufficient to I educe scar formation

10 The method of claim 9, wherein said SMA mducer is TGF-beta

11 The method of either claim 9 or claim 10, wherem said SMA inhibitor is selected from the group consisting of PDGF and an mterferon

12 A method of promoting drug absorption into the vasculature of a patient, compnsmg co-admmistei mg with said drug an SMA lnhibitoi , said inhibitor bemg administered at a dosage sufficient to cause endothehal cell contraction

13 The method of claim 12, wherem said SMA inhibitor is administered mtranasally

14 The method of either claim 12 or claim 13, wherem said SMA inhibitor is selected from the group consisting of PDGF and an mterferon

15 A method of inhibiting tumor cell metastasis m a patient compnsmg admmistenng to said patient an SMA inhibitor at a dosage sufficient to inhibit said metastasis

16 The method of claim 15, wherem said SMA inhibitor is selected from the group consistmg of PDGF and an interferon

17. A method of treating a patient for osteoporosis, comprising acta-inistering an SMA inhibitor to said patient, said inhibitor being administered at a dosage and for a duration sufficient to alleviate one or more symptoms associated with said osteoporosis.

18. The method of claim 17, wherein said SMA inhibitor is PDGF.