WO2015174443A1 - Megakaryocytic differentiation induction and platelet production promoter containing interleukin 1α (il-1α) - Google Patents

Abstract

The objective of the present invention is to provide a medicine or pharmaceutical composition for promoting the induction of megakaryocytic differentiation and/or platelet production. The present invention is a megakaryocytic differentiation induction and/or platelet production promoter that contains IL-1α as an active ingredient. More specifically, the present invention is a karyocyte differentiation induction and/or platelet production promoter that contains, as active ingredients, a polypeptide comprising SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5, or SEQ ID NO: 7, and a polypeptide that is substantially the same as these polypeptides.

Description

Megakaryocyte differentiation inducing and platelet production promoter containing interleukin 1α (IL-1α)

The present invention relates to a pharmaceutical composition for promoting megakaryocyte differentiation induction and / or platelet production.

Platelets are essential cells for blood coagulation (hemostasis), and their demand is extremely high in, for example, bone marrow transplantation and anticancer treatment. Platelets are usually present in blood in amounts sufficient for hemostasis, but the number of platelets is increased by various causes, for example, bleeding due to accidents or treatment with anticancer drugs such as 5-fluorouracil (5-FU). Decrease. When the number of platelets in the body decreases, there is a risk of causing a generalized bleeding tendency, and it is necessary to quickly restore the amount of platelets to the normal amount.
Examples of the treatment for dealing with such a situation include platelet transfusion and a method of increasing the production amount of platelets in a living body. Among them, research on factors necessary for increasing the amount of platelet production in the body has been actively conducted so far, and many platelet production promoting factors have been reported.
Platelets are produced from megakaryocytes (MKs). In vitro, megakaryocytes have been confirmed to produce platelets through the process of polyploidization and cytoplasmic maturation. Thrombopoietin (TPO) has been identified as a factor that induces such megakaryocyte differentiation. There is also a report that CCL27 belonging to the chemokine subfamily induces platelet production (Patent Document 1).

It is said that there are two modes of the platelet production mechanism. One is a mode in which the cytoplasm of mature megakaryocytes expands to form a proplatelet, and platelets are formed from the protruding portions (Non-patent Documents 1 and 2). In vitro, in the presence of TPO, cultured megakaryocyte cells that produce platelets have been shown to exhibit an elongated proplatelet shape. However, there are many unclear points regarding how often and in what circumstances platelet production from propretolets is performed in vivo.
As another platelet production mode, a phenomenon in which megakaryocytes directly produce platelets through their fragmentation has been reported (Non-patent Documents 3 and 4). However, it is unclear what factors affect the mechanism of platelet production in this manner and function at such timing.

At present, it is unclear whether the above-mentioned two modes of platelet production are actually functioning in vivo, and if so, by what mechanism they are producing platelets. There are many points. Therefore, the platelet production promoting factor actually functioning in the living body has not been clarified yet, and it is considered that an unidentified platelet production promoting factor still exists.

Japanese Patent No. 4693348

The object of the present invention is to provide a pharmaceutical composition that promotes megakaryocyte differentiation and / or platelet production, a method for inducing differentiation of megakaryocytes in vitro, a method for producing platelets in vitro, and a method for treating diseases associated with platelet reduction It is to be. In addition, a method for detecting an inapparent bleeding state, bone marrow dysfunction, and the like is provided.

The inventors closely observed the production pattern of platelets from megakaryocytes in vivo and confirmed the existence of two platelet production patterns. These two types of platelet production are the mode in which megakaryocytes extend the cytoplasm to form “proplatelts” and release platelets from the extended part, and the megakaryocyte cells fragment and platelets directly This is the mode of production.
In normal times, there are many short proplatelets, and when platelets are required for a relatively long period of time, such as when thrombopoietin is increased (for example, at the time of bone marrow transplantation), elongated proplatelets are confirmed. From which platelets were produced.
In contrast, when platelets are urgently needed (for example, during blood loss), fragmentation by rupture of mature megakaryocyte cells promoted by the action of interleukin-1α (IL-1α) via the IL-1 receptor Was promoted and platelets were produced.
From the above, it was found that IL-1α also functions as a platelet production-promoting factor in a situation where platelets are urgently needed in vivo.
The present invention has been completed based on these findings.

That is, the present invention includes the following 1 to 5.
1. A megakaryocyte differentiation-inducing and / or platelet production promoter containing IL-1α as an active ingredient.
2. A megakaryocyte differentiation-inducing and / or platelet production promoter containing the following polypeptide (1) or (2) as an active ingredient.
(1) A polypeptide comprising SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5 or SEQ ID NO: 7 (2) In the amino acid sequence represented by SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5 or SEQ ID NO: 7, 1 or 2. A polypeptide comprising an amino acid sequence having several amino acid substitutions, deletions, insertions or additions, and having an activity of inducing differentiation of megakaryocytes and / or promoting platelet production The megakaryocyte differentiation-inducing and / or platelet production promoter according to 1 or 2, further comprising TPO.
4). A method for producing megakaryocytes or platelets, comprising culturing megakaryocyte or platelet progenitor cells in the presence of IL-1α and collecting the produced megakaryocytes or platelets.
5. A method for producing megakaryocytes or platelets, comprising culturing megakaryocytes or platelet precursor cells in the presence of the following polypeptide (1) or (2) and collecting the produced megakaryocytes or platelets: .
(1) A polypeptide comprising SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5 or SEQ ID NO: 7 (2) In the amino acid sequence represented by SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5 or SEQ ID NO: 7, 1 or A polypeptide comprising an amino acid sequence having several substitutions, deletions, insertions or additions, and having an activity of inducing differentiation of megakaryocytes and / or promoting platelet production

The pharmaceutical or pharmaceutical composition of the present invention can promote the production of platelets in vivo by being administered when the platelets are deficient due to a disease associated with a decrease in platelets, surgery, accident, or the like.

The treatment method of the present invention can improve the platelet deficiency that occurs when suffering from certain diseases or blood loss due to surgery or accident.

The megakaryocyte induction method and the platelet production promotion method of the present invention exhibit the effect of promoting the differentiation of megakaryocytes or platelet precursor cells in vitro, efficiently inducing the differentiation of megakaryocytes, and promoting the production of platelets in vitro. To do.

Two platelet production modes in vivo. Time-lapse image of platelet production in bone marrow collected from 6-week-old CAG-eGFP mice. The injected fluorescent dextran shows blood flow (dextran, the direction of blood flow is indicated by an arrow), and the stained image by Hoechst shows the nucleus. In addition, a display of Δ indicates a site where platelets are released. m is minute. A and B: The figure which showed a mode that platelets were produced by the rupture of a megakaryocyte. In a ruptured form of platelet production, megakaryocytes change their cell shape (10 m for A, 12 m for B), and then form a proplatelet with protrusions extending in all directions (16 m for A, B 13m). Thereafter, the cytoplasm ruptures (A 24 m). C and D: A proplatelet with protrusions extending in one direction and a small piece (platelet) released therefrom (C 18m, D 26m). Screening of humoral factors using cultured bone marrow cells. A: Bone marrow cells isolated from 6-week-old mice were cultured in the presence or absence of TPO (50 ng / ml) and SCF (50 ng / ml). After 7 days of culture, they were secreted into the medium by MAPs assay. Liquid factors were evaluated (Charles River). MAPs ratio (TPO + SCF / control) is shown. Seven factors with a ratio of 2.5 or more were identified. MPO; myeloperoxidase, LT; lymphotactin, GCP; granulocyte chemotactic protein. B: Bone marrow cells are recovered and recombinant IL-1α (50 ng / ml), IL-1β (50 ng / ml) , IL-2 (50 ng / ml), IL-3 (50 ng / ml), IL-6 (50 ng / ml), MPO (100 ng / ml), LT (50 ng / ml), IL-12 The cells were cultured in the presence of Subunit p70 (50 ng / ml) or GCP-2 (50 ng / ml), and the number of Lin ⁻ CD41 ⁺ CD42b ⁺ mature megakaryocytes was analyzed after 7 days of culture. % Values were normalized to control cells. Effect of IL-1α on the induction of megakaryocyte differentiation and platelet production in vivo. A: Number of megakaryocytes in 6 week old CAG eGFP mice treated with TPO (10 μg / mouse subcutaneously administered daily for 5 days) or recombinant IL-1α (10 μg / mouse subcutaneously administered daily for 5 days) And platelet count was quantified. The bone marrow was visualized and the platelet count was counted 7 days after the first dose. Total: the total number of megakaryocytes, proplt: the number of megakaryocytes in the form of the proplatelet, rupture: the number of megakaryocytes in the bursting form, Pltcount: the number of platelets, HPF: high-power field. B: 6-week-old wild-type mouse in vehicle (CTRL: control), TPO (10 μg per mouse subcutaneously administered daily for 5 days), recombinant IL-1α (10 μg per mouse subcutaneously administered daily for 5 days) , Treated with neutralizing antibody against IL-1α (IL-1Ab), neutralizing antibody against IL-1R (IL-1RAb) or isotype identical antibody (IgG1 against IL-1R, IgG2 against IL-1RAb) The number of platelets in the isolated blood was counted. All antibodies were subcutaneously administered daily for 3 days at 100 μg per mouse. Blood was collected 3 and 7 days after the first dose. The changes of megakaryocyte morphology and IL-1α and TPO levels in blood loss were investigated. In 6-week-old CAG eGFP mice, sudden blood loss occurred (500 μl blood was collected per mouse), and the morphology of megakaryocytes and the levels of IL-1α and TPO in the serum were examined. The left figure shows the changes in the total number of megakaryocytes (total), the number of megakaryocytes in the proplatelet form (prolt), the number of megakaryocytes in the ruptured form (rupture), and the right figure shows the IL-1α and TPO levels. Showing change. Changes in megakaryocyte morphology, platelet count, and IL-1α and TPO levels after 5-FU and thioglycolate administration were examined. 5-Fluorouracil was administered (5-FU, 250 mg / kg intraperitoneally administered) (A), and thioglycolate-induced acute intraperitoneal inflammation (3% 3 ml per mouse ip) The megakaryocyte morphology and number, platelet count and serum IL-1α and TPO levels when (B) was caused were examined. In A and B, the left figure shows changes in the total number of megakaryocytes (total), the number of megakaryocytes in the form of proplatelets (prolt), and the number of megakaryocytes in the bursting form (rupture), respectively. Changes in IL-1α and TPO levels and platelet count (Plt) are shown. Changes in megakaryocyte morphology, platelet count, and IL-1α and TPO levels after bone marrow transplantation were examined. Six-week-old wild-type mice were irradiated with lethal radiation at 9.5 Gy, and bone marrow derived from CAG eGFP mice at the same week was transplanted. The left figure shows the changes in the total number of megakaryocytes (total), the number of megakaryocytes in the proplatelet form (prolt), the number of megakaryocytes in the ruptured form (rupture), and the right figure shows the IL-1α and TPO levels. Changes and changes in platelet count are shown. Induction of megakaryocyte differentiation and platelet production using liver cells derived from mouse fetuses. Liver cells were collected from CAG eGFP mice on day 13 of fetal period. After 7 days in culture, the cells were washed and incubated with anti-CD-41 antibody, Hoechst 33342. The megakaryocytes were identified with the indication that they were multinucleated and stained with CD41. The time-lapse image of the megakaryocyte culture cell processed by TPO (50mg / ml) (A) and recombinant IL-1 (alpha) (50ng / ml) (B) is shown. Propletlets were observed in the presence of TPO, while megakaryocyte rupture was observed in the presence of IL-1α. IL-1α megakaryocyte differentiation induction and platelet production promoting effect on mouse and human cells. A and C: bone marrow cells derived from 6-week-old wild type mice (A) or human-derived CD34-positive bone marrow cells (C), IL-1α (50 ng / ml) alone or TPO (50 ng / ml) ) And SCF (50 ng / ml) in the presence of 7 days, and the number of Lin ⁻ CD41 ⁺ CD42b ⁺ differentiated megakaryocytes was analyzed. B and D: The production of CD41 ⁺ CD42b ⁺ platelets was analyzed in the same manner as in A and C. B is the result of a bone marrow cell derived from a week-old wild type mouse, and D is the result of a bone marrow cell derived from a human. The relative ratio of megakaryocyte counts and% platelet count values were normalized to control cells. Effect of IL-1α on megakaryocytes derived from human iPS cells. The results of measuring the number of platelets with a flow cytometer when cultured with and without adding IL-1α (Control) are shown (A). In the figure, the horizontal axis indicates the fluorescence intensity when stained with the anti-CD41a antibody, and the vertical axis indicates the fluorescence intensity when stained with the anti-CD42b antibody. The measured platelet count is shown graphically (B). In the figure, the vertical axis shows the number of platelets of CD41a ⁺ / CD42b ⁺ released from 1 × 10e5 megakaryocyte cell lines cultured in 2 ml of the culture solution.

The first embodiment of the present invention is a pharmaceutical or pharmaceutical composition containing interleukin 1α (hereinafter, IL-1α) as an active ingredient. In particular, the medicament or pharmaceutical composition of the present invention has the effect of promoting megakaryocyte differentiation induction and / or platelet production in vivo. Therefore, the medicament or pharmaceutical composition of the present invention is a megakaryocyte differentiation inducer and a platelet production promoter. In the present specification, “IL-1α”, “IL-1α protein”, and “IL-1α polypeptide” are synonymous unless otherwise specified. In addition, “mature IL-1α” and “IL-1α” have the same meaning, and when referring to IL-1α before maturation, it is described as “precursor IL-1α”.
IL-1 is a physiologically active substance known as an inflammatory cytokine, and plays an important role in inflammation and defense against infection. IL-1 is secreted from macrophages and monocytes and activates vascular endothelial cells, lymphocytes, macrophages, etc., and as a result, induces expression of various cytokines, chemokines, inflammatory mediators, etc., causing inflammation It is believed that. Two types of IL-1 have been identified, IL-1α and IL-1β, and these genes exist in close proximity on the same chromosome. About 25% homology is recognized between the amino acid sequences of IL-1α and IL-1β, and it is known to bind to the same receptor.

The present invention is a new function of IL-1α in vivo, that is, a function of inducing differentiation of megakaryocyte progenitor cells into megakaryocytes, causing rupture and fragmentation of mature megakaryocytes, and promoting platelet production It was completed based on the first finding. Here, the active ingredient of the medicament or pharmaceutical composition of the present invention, or IL-1α used for inducing differentiation of megakaryocytes and / or promoting platelet production is conventionally known to those skilled in the art. It is.
As IL-1α used in the present invention, any animal species can be used. When used as an active ingredient of a medicine or pharmaceutical composition, it is preferable to use a human-derived one, but it does not necessarily have to be a human-derived one as long as it does not cause symptoms such as side effects. Moreover, even if it is naturally derived, it can be used even if it is a recombinant produced by genetic engineering techniques.
Examples of the amino acid sequence of IL-1α include, but are not limited to, SEQ ID NO: 1 (human), SEQ ID NO: 3 (mouse), SEQ ID NO: 5 (rat), SEQ ID NO: 7 (rabbit), and the like. . In addition, “IL-1α” referred to in the present invention includes polypeptides that are considered to be substantially the same as naturally-occurring IL-1α. A polypeptide that is considered to be substantially identical to a naturally occurring IL-1α is, for example, 1 or 2 in the amino acid sequence of a naturally occurring IL-1α (eg, SEQ ID NOs: 1, 3, 5, and 7). A polypeptide having an amino acid sequence in which several amino acids are substituted, deleted, inserted, or added, and having an activity of inducing differentiation of megakaryocytes and / or promoting production of platelets. The polypeptide of the present invention is not limited to this as long as the amino acid has a peptide bond, and includes a structure other than the polypeptide (eg, sugar chain). Also good.

IL-1α used in the present invention may be purified from natural sources, synthesized by chemical synthesis or genetic engineering techniques, or purchased commercially ( For example, it can be purchased from R & D Systems).
When IL-1α is prepared by a genetic engineering technique, a gene encoding IL-1α can be obtained by a known method, expressed in an appropriate host cell, purified and prepared. In nature, IL-1α is expressed as a precursor protein, which is then processed to become active mature IL-1α. SEQ ID NOs: 1, 3, 5, and 7 exemplified above are the amino acid sequences of mature IL-1α. The nucleic acid sequences encoding these mature IL-1αs are the nucleic acid sequences of SEQ ID NO: 2, SEQ ID NO: 4, SEQ ID NO: 6 and SEQ ID NO: 8, respectively. It is an illustration of the nucleic acid sequence information which codes. Those skilled in the art, using well-known techniques, are mature IL-1α polypeptides and variants thereof (amino acid sequences with one or several amino acid substitutions, deletions, insertions or additions), and megakaryocytes It is easy to obtain a nucleic acid encoding a polypeptide having the activity of inducing differentiation and / or promoting platelet production.

The mature IL-1α polypeptide of the present invention can be produced by incorporating a nucleic acid sequence encoding the polypeptide into an appropriate expression vector and expressing it in an appropriate host cell.
As an expression vector, when Escherichia coli is used as a host, for example, pBR322, pBR325, pUC118, pUC119, pUC18, pUC19, pCBD-C, etc., animal cells such as pGEX-4T (GE Healthcare) In this case, for example, pEGF-C, pEGF-N (Clontech), and when insect cells are used as hosts, for example, pFastBac HT (Life Technology) can be used. When yeast cells are used as hosts, for example, pPICZ (Life Technology) can be used.

The promoter used for expressing the mature IL-1α polypeptide is not particularly limited, and an appropriate promoter may be used according to the host cell to be used. For example, when animal cells are used as the host, SRα promoter, CMV promoter, SV40 promoter can be mentioned. When the host is Escherichia coli, examples include tac promoter, trp promoter, lac promoter, and when the host is Bacillus subtilis, examples include SPO1 promoter and penP promoter. Moreover, when the host is yeast, PHO5 promoter, PGK promoter, GAP promoter and the like can be mentioned. Further, when the host is an insect cell, polyhedrin promoter, P10 promoter and the like can be mentioned.

Known polynucleotide sequences that promote the secretion of mature polypeptides include secretory sequences (signal sequences), leader sequences, and the like. In addition to these sequences, a tag sequence (His tag, HA tag, etc.) used for purification of the mature polypeptide may be expressed.
In addition, the method of transduction / transformation, the method of culturing the transduced cells and the like can be easily selected by those skilled in the art.

The medicament or pharmaceutical composition of the present invention contains IL-1α as an active ingredient, and based on its megakaryocyte differentiation-inducing activity and / or platelet production-promoting activity, improves the platelet reduction state and reduces platelets. Useful for various diseases involved. Therefore, the medicament or pharmaceutical composition of the present invention is particularly useful as a megakaryocyte differentiation inducer and / or a platelet production promoter. In particular, IL-1α has the ability to promote platelet production in vivo more rapidly after administration than TPO, which is a known platelet production-promoting factor (see, for example, FIG. 3B). Therefore, the medicament or pharmaceutical composition containing IL-1α of the present invention is also effective in improving the platelet deficiency due to sudden blood loss accompanying an accident or the like.

Examples of various diseases associated with platelet reduction include, but are not limited to, acute leukemia, sudden leukemia, chronic aplastic anemia, thrombocytopenia caused by drug administration (eg, bone marrow due to medication treatment such as anticancer drugs) Thrombocytopenia caused by suppression of function), pernicious anemia, myelodysplastic syndrome, malignant lymphoma, sepsis, sarcoidosis, hemangioma and the like. In addition, it is also useful as a therapeutic agent for improving platelet deficiency caused by bleeding during surgery and accidents.

The active ingredient of the medicament or pharmaceutical composition of the present invention may be in the form of a physiologically acceptable salt. Examples of the salt include alkali metal and alkaline earth metal salts such as lithium, sodium, potassium, magnesium, and calcium; ammonia, methylamine, dimethylamine, trimethylamine, dicyclohexylamine, tris ( A salt of an amine such as hydroxymethyl) aminomethane, N, N-bis (hydroxyethyl) piperazine, 2-amino-2-methyl-1-propanol, ethanolamine, N-methylglucamine, L-glucamine; or lysine; Salts with basic amino acids such as δ-hydroxylysine and arginine can be formed. If basic groups are present, salts of mineral acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid; methanesulfonic acid, benzenesulfonic acid, paratoluenesulfonic acid, acetic acid, propionate, tartaric acid , Fumaric acid, maleic acid, malic acid, oxalic acid, succinic acid, citric acid, benzoic acid, mandelic acid, cinnamic acid, lactic acid, glycolic acid, glucuronic acid, ascorbic acid, nicotinic acid, salicylic acid and other organic acids Salts; or salts with acidic amino acids such as aspartic acid and glutamic acid.

The pharmaceutical agent of the present invention may be administered with IL-1α as an active ingredient, but in general, in addition to IL-1α as an active ingredient, a pharmaceutical composition comprising one or more pharmaceutical additives It is desirable to administer in the form. Further, the pharmaceutical composition of the present invention contains, as its active ingredient, a substance having an effect of inducing differentiation of megakaryocytes or an effect of promoting platelet production (for example, thrombopoietin (TPO)) as an active ingredient. But you can. Or you may administer combining the pharmaceutical which uses IL-1 (alpha) of this invention as an active ingredient, and another pharmaceutical (for example, TPO etc.).
The type of pharmaceutical composition is not particularly limited, and dosage forms include tablets, capsules, granules, powders, syrups, suspensions, suppositories, ointments, creams, gels, patches, inhalants, An injection agent etc. are mentioned. These preparations are prepared according to a conventional method. In the case of a liquid preparation, it may be dissolved or suspended in water or other appropriate solvent at the time of use. Tablets and granules may be coated by a known method. In the case of injection, it is prepared by dissolving the compound of the present invention in water, but it may be dissolved in physiological saline or glucose solution as necessary, and a buffer or preservative may be added. Good. It is provided in any dosage form for oral or parenteral administration. For example, a pharmaceutical composition for oral administration in the form of granules, fine granules, powders, hard capsules, soft capsules, syrups, emulsions, suspensions or liquids, for intravenous administration, for intramuscular administration, Alternatively, it can be prepared as a pharmaceutical composition for parenteral administration in the form of injections, drops, transdermal absorbents, transmucosal absorbents, nasal drops, inhalants, suppositories, etc. for subcutaneous administration. Injections, infusions, and the like can be prepared as powdered dosage forms such as freeze-dried forms, and can be used by dissolving in an appropriate aqueous medium such as physiological saline at the time of use. It is also possible to administer a sustained release preparation coated with a polymer directly into the brain.

A person skilled in the art can appropriately select the type of pharmaceutical additive used for the production of the pharmaceutical composition, the ratio of the pharmaceutical additive to the active ingredient, or the method for producing the pharmaceutical composition depending on the form of the composition. It is. As the additive for preparation, an inorganic or organic substance, or a solid or liquid substance can be used, and generally it can be blended in an amount of 1 to 90% by weight based on the weight of the active ingredient. Specifically, examples of such substances are lactose, glucose, mannitol, dextrin, cyclodextrin, starch, sucrose, magnesium aluminate metasilicate, synthetic aluminum silicate, sodium carboxymethylcellulose, hydroxypropyl starch, carboxymethylcellulose calcium. , Ion exchange resin, methyl cellulose, gelatin, gum arabic, hydroxypropyl cellulose, hydroxypropyl methylcellulose, polyvinyl pyrrolidone, polyvinyl alcohol, light anhydrous silicic acid, magnesium stearate, talc, tragacanth, bentonite, bee gum, titanium oxide, sorbitan fatty acid ester, Sodium lauryl sulfate, glycerin, fatty acid glycerin ester, purified lanolin, glycerogelatin, polyso Bate, macrogol, vegetable oils, waxes, liquid paraffin, white petrolatum, fluorocarbons, nonionic surfactants, propylene glycol, water and the like.

In order to produce a solid preparation for oral administration, an active ingredient and excipient components such as lactose, starch, crystalline cellulose, calcium lactate, anhydrous silicic acid and the like are mixed to form a powder, or if necessary, sucrose, Add a binder such as hydroxypropylcellulose and polyvinylpyrrolidone, a disintegrant such as carboxymethylcellulose and carboxymethylcellulose calcium, and wet or dry granulate to form granules. In order to produce tablets, these powders and granules may be tableted as they are, or by adding a lubricant such as magnesium stearate and talc. These granules or tablets should be coated with an enteric solvent base such as hydroxypropylmethylcellulose phthalate or methacrylic acid-methyl methacrylate polymer and coated with an enteric solvent preparation, or with ethylcellulose, carnauba wax, hardened oil, etc. You can also. In order to produce capsules, powder capsules or granules are filled into hard capsules, or active ingredients are coated as they are or dissolved in glycerin, polyethylene glycol, sesame oil, olive oil, etc., and then coated with a gelatin film to form soft capsules. be able to.

In order to produce injections, active ingredients such as hydrochloric acid, sodium hydroxide, lactose, lactic acid, sodium, sodium monohydrogen phosphate, sodium dihydrogen phosphate, etc. Dissolve in distilled water for injection together with an isotonic agent, filter aseptically and fill into ampoules, or add mannitol, dextrin, cyclodextrin, gelatin, etc. . In addition, reticine, polysorbate 80, polyoxyethylene hydrogenated castor oil and the like can be added to the active ingredient and emulsified in water to give an emulsion for injection.

To produce a rectal dosage form, the active ingredient is moistened with a suppository base material such as cacao butter, fatty acid tri, di- and monoglycerides, polyethylene glycol, etc., dissolved, poured into a mold and cooled, or the active ingredient is made of polyethylene. What is necessary is just to coat | cover with a gelatin film etc., after melt | dissolving in glycol, soybean oil, etc.

The dose and frequency of administration of the medicament or pharmaceutical composition of the present invention are not particularly limited, and the purpose and type of the disease, the patient's weight and age, the severity of the disease, prevention and / or treatment of the disease to be treated Depending on the condition such as the degree, it is possible to make an appropriate selection according to the judgment of the doctor. In general, the dose per day for an adult in oral administration is about 0.01 to 1000 mg (active ingredient weight), and can be administered once or several times a day or every few days. When used as an injection, daily dosages of 0.001 to 400 mg (active ingredient weight) are preferably administered continuously or intermittently to adults.

The medicament or pharmaceutical composition of the present invention can be prepared as a sustained release preparation such as a delivery system encapsulated in implantable tablets and microcapsules using a carrier that can prevent immediate removal from the body. . As the carrier, for example, biodegradable and biocompatible polymers such as ethylene vinyl acetate, polyanhydride, polyglycolic acid, collagen, polyorthoester, and polylactic acid can be used. Such materials can be readily prepared by those skilled in the art. Liposome suspensions can also be used as pharmaceutically acceptable carriers. Useful liposomes are prepared as a lipid composition comprising, but not limited to, phosphatidylcholine, cholesterol and PEG-derivatized phosphatidylethanol (PEG-PE) through a filter of appropriate pore size so as to be suitable for use, and in reverse phase. Purified by evaporation.

Furthermore, the present invention includes a method for improving the platelet deficiency state by administering the pharmaceutical or pharmaceutical composition of the present invention to a patient or the like, and a method for preventing or treating various diseases accompanied by platelet reduction. .
Here, “treatment” means to prevent or alleviate the progression and worsening of the pathological condition in mammals suffering from diseases associated with platelet reduction, in addition to improving platelet reduction itself. Is a treatment aimed at increasing the amount of platelets in the body or preventing or alleviating the progression and worsening of the disease.
In addition, “prevention” refers to a decrease in platelets or the onset or illness of a mammal that is in a state where platelet reduction is expected, or a mammal that may suffer from a disease associated with platelet reduction. Is a treatment aimed at preventing the onset of various symptoms of the disease in advance.

The “mammal” to be treated means any animal classified as a mammal, and is not particularly limited. For example, in addition to humans, pet animals such as dogs, cats, rabbits, cows, pigs, sheep , Livestock animals such as horses. Particularly preferred “mammals” are humans.

In a second embodiment of the present invention, a megakaryocyte or platelet progenitor cell is transformed into a megakaryocyte (Lin ⁻ CD41 ⁺ , Lin ⁻ ) in the presence of IL-1α or a polypeptide considered to be substantially identical to IL-1α. ^{CD42b +, Lin - CD41 + /} CD42b + or, GPA ^- / CD41 ⁺⁾ to induce differentiation into, causing ruffling and fragmentation of megakaryocytes, promotes the production of platelets, to produce megakaryocytes and platelets Is the method. Here, the precursor cells of megakaryocytes or platelets are cell populations derived from bone marrow (herein referred to as bone marrow cells. Various cells, cells of various differentiation stages may be included), hematopoietic progenitor cells (for example, , CD34 ⁺ cells, Lin ⁻ (CD2, CD3, CD4, CD7, CD8, CD10, CD14, CD16, CD19, CD20, CD24, CD41, CD45, CD56, CD66b or CD235a negative) cells, etc.), megakaryocyte progenitor cells ( CD41 ⁺ the CD 9 ⁺ cells), and the like multinucleated previous undifferentiated megakaryocytes. Platelet progenitor cells include megakaryocytes. In addition, hematopoietic progenitor cells, megakaryocyte progenitor cells, megakaryocytes, etc. may be cells collected from bone marrow, or cells induced to differentiate from pluripotent stem cells (ES cells, iPS cells, etc.) Also good. Differentiation induction of megakaryocyte progenitor cells from pluripotent stem cells may be performed according to methods known to those skilled in the art, for example, as described in Nakamura S, et al., Cell Stem Cell. 14: 535-548, 2014. It can be implemented by referring to the method. Specifically, exogenous c-MYC and BMI1 were expressed on hematopoietic progenitor cells derived from pluripotent stem cells for 7 to 14 days, and then exogenous BCL-XL was expressed. Can be induced. In this case, a method of culturing in a culture solution containing TPO and / or SCF is exemplified. When a megakaryocyte is induced from a megakaryocyte precursor cell derived from the pluripotent stem cell, it can be induced by stopping the expression of the introduced exogenous c-MYC, BMI1 and BCL-XL.

The present invention includes a kit for inducing differentiation of megakaryocytes and promoting the production of platelets from megakaryocytes or platelet precursor cells in vitro. The megakaryocyte and platelet production kit of the present invention contains a known megakaryocyte differentiation inducer and / or a platelet production promoting substance (for example, TPO) in addition to IL-1α as an active ingredient in some cases. May be. Moreover, if necessary, a buffer, a progenitor cell, and the like necessary for inducing differentiation of megakaryocytes and / or promoting production of platelets may be included. In the kit of the present invention, different constituents of the composition are packaged in separate containers, used according to each method of use immediately before use, and mixing of components that require mixing is performed.
Reagents, cells, and the like contained in the kit are supplied into a container made of a material that maintains the activity of the component effectively for a long period of time and does not alter the component.

Also, instructions for use may be attached to the kit. Instructions for using this kit are printed on paper and / or stored on an electrically or electromagnetically readable medium such as a floppy disk, CD-ROM, DVD-ROM, etc. It may be supplied. Detailed instructions for use may be actually attached to the kit, or may be posted on a website designated by the manufacturer or distributor of the kit or notified by e-mail or the like.

Furthermore, the present invention includes a method for detecting an inapparent blood loss state or a suppression state of bone marrow function in the body. As described above, IL-1α has an effect of inducing differentiation of megakaryocytes and / or promoting platelet production in vivo. In a state of sudden blood loss or urgently requiring platelets such as administration of 5-FU that suppresses bone marrow function or administration of thioglycolate that induces acute peritonitis, IL- The inventors have shown that the level of 1α increases rapidly (see FIGS. 4 and 5). These results show that when the test subject's blood IL-1α level is higher than the normal value (or normal value), platelets are decreased in the subject's body, Or, it indicates that a decrease in bone marrow function is suspected. Therefore, if the level of IL-1α in the blood of the test subject is measured and the value is higher than the normal value (or normal value) (such as the average value of normal healthy subjects), platelets Can be used as an indicator of a decrease in bone marrow, a decrease in bone marrow function, or the onset of a disease causing these conditions.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[Example 1] Effect of Il-1α on megakaryocyte differentiation and platelet production Experimental method 1-1. Experimental animals Wild-type C57BL / 6J mice were purchased from Charles River Laboratories. CAG-eGFP mice expressing eGFP under the control of the chicken β-actin promoter were purchased from Japan SLC Inc. All of the mice used were males, but preliminary experiments showed no significant differences in platelet production due to gender differences. All animal and recombinant DNA experiments were approved by the Animal Care and Use Committee and were performed in strict compliance with the University of Tokyo animal experiment guidelines.

1-2. Animal Model The effect of blood loss on platelet production was examined by collecting 500 μl of blood from the tail blood vessel of 4-12 week old CAG-eGFP mice. The effect of 5FU treatment was analyzed using mice of the same age after 5FU treatment (5-FU, 250 mg / kg dose intraperitoneally, Sigma-Aldrich) . Fluctuations in serum TPO and IL-1α levels after voting or 5FU treatment were evaluated by analyzing blood collected from tail blood vessels by ELISA.
The effect of acute inflammation was analyzed using mice administered intraperitoneally with thioglycolate (Sigma-Aldrich) (3 ml, 3 ml per administration, once administration).
In order to evaluate the recovery status after bone marrow transplantation, bone marrow derived from CAG-eGFP mice of the same week was transplanted into 6-week-old wild type mice, and then 9.5 Gy of radiation corresponding to a lethal dose was irradiated.
In order to examine the influence of humoral factors, CAG-eGFP mice of 5 weeks old were recombinant TPO (Sigma, 10 μg per individual was administered by subcutaneous injection every day for 5 days) or IL-1α (R & D systems) 10 μg per animal was administered daily by subcutaneous injection for 5 days). Seven days after the first treatment, visualization was performed by time-lapse photography.
5-week-old wild-type mice were vehicle (control), TPO (10 μg per animal administered daily by subcutaneous injection for 5 days), recombinant IL-1α (10 μg per animal administered daily by subcutaneous injection for 5 days) ), Neutralizing antibody against IL-1α (clone # 40508, IL-1Ab: R & D systems), neutralizing antibody against IL-1R (clone JAMA-147, IL-1RAb: Biolegend), and control with the same isotype Treatment with antibody (Biolegend). All antibodies were administered intraperitoneally every day for 3 days at 100 μg per mouse. The platelet count was analyzed 7 days after the first administration.

1-3. In vivo microscopy of platelet production in living bone marrow To visualize the dynamics of megakaryocytes in the bone marrow of the skull, a double photon microscope modified from the conventional single photon method was used in vivo (Choi et al., Blood 85, 402-413 1995; Cramer et al., Blood 89 2336-2346 1997). Male CAG-eGFP mice were anesthetized by injecting urethane (1.5 g / kg), then the scalp was removed and fixed on a high-temperature stage (Tokai Hit) of an inverted microscope (Nikon, Eclipse Ti) did. Texas Red Dextran (25 mg / kg, 70 kDa, D1830: Invitrogen) and Hoechst 33342 (10 mg / kg, H1399: Invitrogen) were injected into mice to visualize cell dynamics and blood flow. The tissue was excited using a Ti: sapphire laser (Visio II, Coherent) at a wavelength of 860 nm and the image was stored. In the Z direction, about 50 μm was observed in a 1 μm thick section. Images were stored at 1.5x magnification using a 40x water immersion objective (Nikon).

1-4. Cultivation of Bone Marrow Cells from Mouse After isolation of whole bone marrow cells from 6-week-old wild type mice, 5 x 10 ⁴ cells were treated with 2 ml Dulbecco's modified Eagle's medium (DMEM) + 10% FBS in TPO (50 ng / ml) and SCF (50 ng / ml: Sigma) or in the absence (control).
After 7 days of culture, the medium and cells were collected. The humoral factors secreted from the cells into the medium were analyzed by microbead-based MAPs (Multi-Analyte Profiles) analysis (Charles River). The cells were analyzed using flow cytometry and RT-PCR to evaluate megakaryocyte differentiation and platelet release into the medium. In addition, in order to investigate the influence of humoral factors on cells, recombinant cells such as IL-1α, IL-1β (50 ng / ml, R & D systems), IL-2 (50 ng / ml, R & D systems) , IL-3 (50 ng / ml, R & D systems), IL-6 (50 ng / ml, R & D systems), myeloperoxidase (MPO, 100 ng / ml, R & D systems), lymphotactin (LT, 50 ng / ml, R & D systems), IL-12 subunit p70 (50 ng / ml, R & D systems) or granulocyte chemotactic protein-2 (GCP-2, 50 ng / ml, Biolegend) for 7 days.

1-5. Culture of fetal liver cells Liver was obtained from fetal CAG-eGFP mouse fetuses of 13 days. Single cell suspensions were prepared with DMEM supplemented with 10% FCS through 22- and 25-gauge needles through the liver. The culture was performed in the presence or absence (control) of TPO (50 ng / ml), SCF (50 ng / ml) and / or recombinant IL-1α (50 ng / ml). On day 4 of culture, cells were washed and incubated in the presence of anti-CD41 (MWReg30, Biolegend) and Hoechst 33342 to identify megakaryocytes. Megakaryocyte dynamics (propretlet formation and cell rupture) were observed in culture at 37 ° C. and visualized using the Nikon-A1R system.

1-6. Immunohistochemistry In immunohistochemical analysis, cells were fixed with 4% formaldehyde for 45 minutes, and membrane permeabilized with 1% Triton X-100 (CalBiochem) for 10 minutes. After blocking with 1% BSA and reacting with primary antibody (anti-β1 tubulin antibody) for 12 hours, Alexa Fluor 488-conjugated secondary antibody (Molecular Probes, Eugene) and RPE-conjugated anti-CD41 antibody (MWReg30 ) For 1 hour. In addition, cells were stained with 20 μM Hoechst 33342 for 1 hour to visualize nuclei. Cell images were collected using a confocal microscope (NikonA1R).

1-7. Cell Preparation and Flow Cytometry Bone marrow was isolated by vigorous injection of PBS into the skull and femur. Blood samples were taken from the tail vessels. The collected cells were washed twice with PBS and incubated in erythrocyte hemolysis buffer for 10 minutes. Thereafter, it was resuspended in PBS supplemented with 3% FBS. Thereafter, 60 ng of FcBlock antibody (553141, BD Pharmingen) per 1 × 10 ⁶ cells was added and incubated on ice for 15 minutes. The isolated cells were labeled with a monoclonal antibody or a control antibody having the same isotype and subjected to flow cytometry analysis.
The antibodies used were CD3 (145-2C11, BD Pharmingen), CD4 (RM4-5, BD Pharmingen), CD8a (53-6.7, BD Pharmingen), CD11b (M1 / 70, eBioscience), CD19 ( MB19-1, eBioscience), CD41 (MWReg30, eBioscience), CD42b (Xia.G5, emfret), CD45R (RA3-6B2, Biolegend), Ter-119 (TER-119, Biolegend) and Ly- 6G (RB6-8C5, Biolegend).

1-8. Statistical processing Statistical processing was performed using JMP 8.0 (SAS) software. The results were expressed as means ± SEM. Statistical significance between the two groups was assessed by Student's t test. Differences between two or more groups were evaluated using analysis of variance (ANOVA) by the post-hoc Bonfellini method. Correlation was evaluated using the Pearson correlation coefficient test. A P value <0.05 was considered significant. Regression analysis was used to confirm the independent determinants of platelet count and the percentage of mutations indicated by them.

2. Result 2-1. Two modes of platelet production In order to elucidate the mode of platelet production in vivo, the live bone marrow of CAG-eGFP mice was visualized and observed. Megakaryocytes were identified using the cell size, multinuclearity, and strong GFP signal as indicators. In addition, fluorescently labeled dextran and Hoechst (Hoechst33342) were each injected into mice to visualize the blood flow and cell nuclei of living mice (FIG. 1).
One observed mode of platelet production is that megakaryocytes rupture and produce platelets from their cytoplasmic fragments (FIGS. 1A, B). The other mode is that megakaryocytes form protoplatelets and release platelets from the protrusions (FIGS. 1C, D).
Cell fragmentation caused by the rupture of megakaryocyte cells initially luffed into an irregular shape, increasing the intensity of GFP in the region near the cell membrane. Thereafter, the fluorescence of cytoplasm-derived GFP disappeared, and the signal derived from the Texas Red label of dextran (indicating blood flow) increased (FIG. 1A). In this series of processes, no change occurred in the position of the nucleus and the ploidy of the nucleus, but it was confirmed that a small piece emitting a strong GFP signal was released from the cell into the bloodstream in all directions (FIG. 1A, 28m). The average diameter of these pieces is larger than those circulating in the blood and may be “large preplatelet intermediates” or “protoplatelets” (Kosaki et al., Int J Hematol 88, 255-267 2008; Thon et al., J Cell Biol. 191, 861-874 2011).
On the other hand, in the mode in which platelets are released by forming a proprelet, platelet-like pieces are released directly into the bloodstream from the elongated proplatelet (FIGS. 1C and 1D). Platelets produced via propretolets are thought to become mature platelets (~ 2 μm) in the bone marrow.
Both the above two platelet production modes were confirmed in the same mouse individual.

2-2. Humoral factors involved in platelet production To date, it has been known that TPO plays an important role in the process of megakaryocyte differentiation and maturation. In addition, IL-3, IL-6, and IL-11 are not essential factors for platelet production, but it has been suggested that they can work cooperatively with TPO (Patel et al., J Clin Invest 115, 3348 -3354 2005). In addition, there is a report that sphingosine monophosphate induces the elongation of megakaryocyte vesicles in vivo (Zhang et al., J Exp Med 209, 2165-2181 2012). Therefore, we decided to try to identify unidentified factors involved in platelet production, especially humoral factors involved in acute platelet production (platelet production when platelets are urgently needed, such as during sudden blood loss). .
First, bone marrow cells were cultured for 7 days in the presence of TPO and SCF, and humoral factors released into the medium were examined. As a result of the MAPs analysis, seven candidate factors were identified (FIG. 2A), and the differentiation induction efficiency from cultured bone marrow cells to CD42b ⁺ CD41 ⁺ megakaryocytes was evaluated for these factors (FIG. 2B). IL-1β, IL-6, and the like showed only a weak effect, but IL-1α significantly increased the amount of platelet production, and showed higher platelet production ability than when TPO was added (FIG. 2B). ). In addition, the frequency of cell rupture accompanied by fragmentation of megakaryocyte cells was significantly reduced by the administration of TPO (FIG. 3A). In contrast, the administration of IL-1α (10 μg / mouse administered daily for 5 days) increased the total number of megakaryocytes, without affecting the production of elongated proplatelets, and without disruption of megakaryocyte cells. The frequency increased (Figure 3A). Furthermore, the number of platelets in blood and the number of megakaryocytes in bone marrow increased 3 and 7 days after IL-1α administration, but the effect of TPO administration was observed only after 7 days (FIG. 3B). ). It was confirmed that the platelet count was decreased by the neutralizing antibody for IL-1α and the neutralizing antibody for IL-1 receptor (FIG. 3B).

2-3. Effect of IL-1α on platelet production When sudden blood loss occurs in mice, the megakaryocyte morphological change that mainly occurs is fragmentation of megakaryocytes, paralleling the increase in IL-1α levels (Fig. 4). . Due to sudden blood loss, TPO levels were not immediately affected, but eventually increased after a period of time. In addition, when 5-FU, which suppresses bone marrow function, was administered to mice, platelet production was completely inhibited, and both the frequency of ruptured megakaryocytes and IL-1α levels increased one day after administration. For TPO, the level was gradually increased (FIG. 5A). Furthermore, when peritonitis was induced by thioglycolate administration, megakaryocyte rupture frequency correlated with platelet count and IL-1α level (FIG. 5B). These results indicate that in situations where platelets are urgently needed due to blood loss or acute inflammation in the body, the level of IL-1α, not TPO, rises rapidly and induces platelet formation due to megakaryocyte rupture. Is shown.
In addition, since blood IL-1α level rises rapidly due to blood loss, if the IL-1α level is higher than the normal value (or normal value), an inapparent blood loss has occurred, or It is suspected that suppression of bone marrow function occurs in vivo. For this reason, it is considered possible to find invisible blood loss in the living body or suppression of bone marrow function by using the IL-1α level higher than the normal value (or normal value) as an index.

In contrast to the blood loss, 5-FU treatment and thioglycolate treatment described above, when bone marrow transplantation was performed after irradiation, the platelet count gradually recovered over time. During this recovery period, Platelet production by toret was mainly observed. The serum IL-1α level decreased and the TPO level increased (right in FIG. 6). Proplatelet formation via TPO stimulation is advantageous when platelets are needed over a long period of time. However, in the case of sudden blood loss, it was found that the platelet production mode was changed to the mode by fragmentation due to the rupture of megakaryocytes in correlation with the increase in the level of IL-1α (FIG. 4).
From the above results, megakaryocytes in the bone marrow are clearly different from two different platelet production modes, namely, platelet production from proplatelets involving TPO and platelets resulting from fragmentation of megakaryocytes involving IL-1α. The presence of production was confirmed

2-4. Role sharing between IL-1α and TPO To elucidate the mechanism of action of TPO and IL-1α, liver cells isolated from fetal GFP mice were cultured and analyzed. Five days after culturing, the cells were stained with anti-CD41 antibody and Hoechst. Stimulation with TPO increased the formation of long filopodia-like long protrusions from megakaryocytes (FIG. 7A). In contrast, when stimulated with IL-1α, rupture of megakaryocytes was promoted (FIG. 7B).
In cultured cells derived from mouse bone marrow, TPO and IL-1α each induced differentiation of megakaryocytes (FIG. 8A) and promoted platelet production (FIG. 8B). Similarly, in cells derived from humans, TPO and IL-1α each induced differentiation of megakaryocytes (FIG. 8C) and promoted platelet production (FIG. 8D). When TPO and IL-1α were added simultaneously, the effect was additive (FIGS. 8A, B, C and D).
Furthermore, the small pieces released by IL-1α respond to thrombin stimulation and the activation of platelet integrin αIIbβ3 and platelet aggregation is comparable to that of platelets induced by TPO stimulation and washed platelets used as controls Have confirmed.
From the above results, it is considered that TPO and IL-1α each independently control maturation and dynamics of bone marrow.

[Example 2]
Production of megakaryocytic progenitor cells derived from pluripotent stem cells Semi-confluent iPS cell line SeV2 maintained in a 6 cm dish seeded with MEF (Mouse Embryonic Fibroblast) at 3 x 10 ⁵ cells / dish (method of WO2010 / 134526 In accordance with Sendai virus vector, and prepared by introducing c-MYC, OCT3 / 4, SOX2 and KLF4 into neonate human fibroblast) via iPS-sac (see, for example, WO2009 / 122747) Hematopoietic progenitor cells (HPC) were induced. Specifically, iPS cells were released using a human trypsin solution, and about 1/50 to 1/30 cells were treated with mitomycin C (MMC) as a colony mass. C3H10T1 / 2 (available from RIKEN) Sowing up. The MMC-treated C3H10T1 / 2 was prepared by seeding 10 cm dishes at 8 × 10 ⁵ cells / dish the day before iPS cells were seeded. After seeding, culture was started in Eagel's Basal Medium (EBM) supplemented with 20 ng / ml VEGF in an atmosphere of 5% O ₂ , 5% CO ₂ and 37 ° C. (day 0). On Day 3 and Day 6, the medium was changed with the same medium.

On Day 7, the culture was continued in an atmosphere of 20% O ₂ , 5% CO ₂ and 37 ° C. On Day 9, Day 11 and Day 13, the medium was changed with the same medium. On Day 14, cells were physically detached using a cell scraper or pipette tip, and cells of uniform size were collected through a 40 μM cell strainer. From the cell size, it was confirmed that the collected cells were hematopoietic progenitor cells (HPC).

On Day 14, the collected HPC was seeded at 3 × 10 ⁴ to 1 × 10 ⁵ cells / well on MMC-treated C3H10T1 / 2. The medium used was EBM supplemented with SCF 50 ng / ml, TPO 50 ng / ml, and doxycycline 0.5 μg / ml. Subsequently, c-MYC and BMI1 were introduced into HPC with a lentiviral vector. The lentiviral vector used was a tetracycline-controlled inducible vector, which was prepared by recombining the mOKS cassette of LV-TRE-mOKS-Ubc-tTA-I2G with c-MYC or BMI1 (LV-TRE- c-MYC-xL-Ubc-tTA-I2G or LV-TRE-BMI1-Ubc-tTA-I2G) (Nakamura S, et al, Cell Stem Cell. 14: 535-548, 2014). The virus particles used for the infection were prepared by infecting the lentiviral vector into 293T cells. Protamine was added only at the time of infection. Thereafter, the medium was changed every other day, and C3H10T1 / 2 and the medium were changed once or twice a week.

Two weeks after introducing c-MYC and BMI1, BCL-xl was introduced using a lentiviral vector. The lentiviral vector used for the introduction of BCL-xl is a tetracycline-regulated inducible vector and was prepared by recombination with BCL-xl as described above (LV-TRE-BCL-xL-Ubc-tTA- I2G) (Nakamura S, et al, Cell Stem Cell. 14: 535-548, -2014). Protamine was added only at the time of infection. Thereafter, maintenance culture was performed in 10 cm dish 10T1 / 2 feeder in EBM supplemented with SCF 50 ng / ml, TPO 50 ng / ml, and doxycycline 0.5μg / ml to produce a megakaryocyte progenitor cell line (also called imMKCL) did.

Effect of IL-1α on platelet production ability of pluripotent stem cell-derived megakaryocyte progenitor cells ImMKCL in EBM supplemented with SCF 50 ng / ml, TPO 50 ng / ml, doxycycline 0.5 μg / ml, 5 μM Blebbistatin and 10 μM Y27632 After culturing for 7 days, 100 ng / ml IL-1α was added to EBM (but not including doxycycline) supplemented with SCF 50 ng / ml, TPO 50 ng / ml and 15 μM S45457 (compound described in WO2012 / 036257) or The cells were cultured for 5 days in a culture medium without addition, and the obtained platelets were measured with a flow cytometer (FIG. 9A).
As a result, it was confirmed that when IL-1α was added, the number of platelets produced increased by about 1.4 times compared to the case where IL-1α was not added (FIG. 9B).
From the above results, it was confirmed that IL1-α has an effect of enhancing the platelet production ability against multinucleated megakaryocytes derived from pluripotent stem cells.

In the present invention, the medicine and the pharmaceutical composition have the effect of inducing differentiation of megakaryocytes and promoting platelet production in vivo. Therefore, the medicament or pharmaceutical composition of the present invention has high utility in the medical field as a megakaryocyte differentiation inducer, platelet production promoter and the like.

Claims (5)

1. Megakaryocyte differentiation induction and / or platelet production promoter containing IL-1α as an active ingredient.
2. A megakaryocyte differentiation-inducing and / or platelet production promoter containing the following polypeptide (1) or (2) as an active ingredient.
   (1) A polypeptide comprising SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5 or SEQ ID NO: 7 (2) In the amino acid sequence represented by SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5 or SEQ ID NO: 7, 1 or A polypeptide comprising an amino acid sequence having several amino acid substitutions, deletions, insertions or additions and having an activity of inducing differentiation of megakaryocytes and / or promoting platelet production
3. Furthermore, the differentiation induction of megakaryocytes and / or the platelet production promoter according to claim 1 or 2, further comprising TPO.
4. A method for producing megakaryocytes or platelets, comprising culturing megakaryocytes or platelet precursor cells in the presence of IL-1α and collecting the produced megakaryocytes or platelets.
5. A method for producing megakaryocytes or platelets, comprising culturing megakaryocytes or platelet precursor cells in the presence of the following polypeptide (1) or (2) and collecting the produced megakaryocytes or platelets: .
   (1) A polypeptide comprising SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5 or SEQ ID NO: 7 (2) In the amino acid sequence represented by SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5 or SEQ ID NO: 7, 1 or A polypeptide comprising an amino acid sequence having several amino acid substitutions, deletions, insertions or additions and having an activity of inducing differentiation of megakaryocytes and / or promoting platelet production

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