Composition for inhibiting muscle atrophy

Abstract

To provide a muscle atrophy inhibitory composition.SOLUTION: A muscle atrophy inhibitory composition includes a CXCL10 expression inhibitor as an active ingredient. The muscle atrophy inhibitory composition includes, as an active ingredient, preferably a CXCL10 inhibitor, more preferably a CXCL10 neutralizing antibody, or still more preferably a TRPV2 activator. The muscle atrophy is muscle atrophy of skeletal muscle. There is also provided a screening method for an active ingredient for inhibiting muscle atrophy, using a decrease in the expression level of CXCL10 gene as an index.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a composition for inhibiting muscle atrophy, a method for screening an active ingredient for inhibiting muscle atrophy, and the like. [Background technology]

[0002] Muscle atrophy is known to be caused by diseases of the muscles themselves (myopathic muscular atrophy), motor nerve disorders (neuropathic muscular atrophy), and prolonged bedriddenness or other reduced activity (disuse muscular atrophy). In particular, immobility, inactivity, and reduced physical activity are considered to be important factors in muscle loss. Muscle atrophy reduces muscle mass and strength, and disuse muscular atrophy due to immobility and inactivity is a significant pathological condition that can shorten healthy lifespan, especially in the elderly. However, its pathogenesis is not fully understood, and the development of therapeutic drugs is desired (Patent Document 1).

[0003] Muscle atrophy is known to be caused by a variety of factors, including aging, drugs such as steroids, endocrine disorders, cancer and wasting diseases, chronic kidney disease, chronic liver disease, chronic heart failure, and mental disorders such as depression, and is a major health problem. In particular, sarcopenia (age-related muscle wasting), which is muscle atrophy associated with aging, is one of the major medical challenges in an aging society.

[0004] In addition, antibodies against CXCL10 (CXC motif chemokine ligand 10) have been investigated as treatments for rheumatoid arthritis, ulcerative colitis, Crohn's disease, primary biliary cholangitis, etc., but their effect on muscle atrophy is unknown. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-094308 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a composition for inhibiting muscle atrophy. Another object is to provide a composition for treating or preventing diseases accompanied by muscle atrophy. Another object is to provide a method for screening active ingredients for inhibiting muscle atrophy. [Means for solving the problem]

[0007] The present inventors found that immobilizing the lower limbs of mice in a plaster cast significantly increased gene expression of the transcription factor KLF15 (Krüppel-like factor 15). Furthermore, the present inventors identified the chemokine CXCL10 through comprehensive gene expression analysis of skeletal muscle from a mouse model of immobilization muscular atrophy and from skeletal muscle of a patient with immobilization muscular atrophy. They found that immobilization increases the expression level of CXCL10, and that the increase in CXCL10 expression due to immobilization is suppressed in KLF15-deficient mice, leading to further improvements. Furthermore, the present inventors have investigated the effect of plasma membrane Ca 2+ They found that administering a channel inhibitor to mice also increased the expression level of CXCL10, and further improvements were made.

[0008] The present disclosure encompasses, for example, the subject matter described in the following sections: Section 1. A composition for inhibiting muscle atrophy, comprising a CXCL10 expression inhibitor as an active ingredient. Section 2. Item 1. A composition for inhibiting muscle atrophy according to Item 1, which contains a CXCL10 inhibitor as an active ingredient. Section 3. Item 3. A composition for inhibiting muscle atrophy according to Item 1 or 2, which contains a CXCL10 neutralizing antibody as an active ingredient. Section 4. A composition for inhibiting muscle atrophy, containing a TRPV2 activator as an active ingredient. Section 5. A composition for treating or preventing a disease accompanied by muscle atrophy, comprising a CXCL10 expression inhibitor as an active ingredient. Section 6. Item 6. A composition for treating or preventing a disease accompanied by muscle atrophy according to Item 5, comprising a CXCL10 inhibitor as an active ingredient. Section 7. Item 7. A composition for treating or preventing a disease accompanied by muscle atrophy according to Item 5 or 6, comprising a CXCL10 neutralizing antibody as an active ingredient. Section 8. A composition for treating or preventing diseases accompanied by muscle atrophy, comprising a TRPV2 activator as an active ingredient. Section 9. Item 9. The composition according to any one of Items 1 to 8, wherein the muscle atrophy is skeletal muscle atrophy. Section 10. A method for screening for active ingredients for suppressing muscle atrophy using a decrease in the expression level of the CXCL10 gene as an indicator. [Effects of the Invention]

[0009] A composition for inhibiting muscle atrophy is provided, and a method for screening an active ingredient for inhibiting muscle atrophy is also provided. [Brief explanation of the drawings]

[0010] [Figure 1-1] The graph shows the changes in CXCL10 expression levels due to immobilization, KLF15 expression levels due to plaster cast immobilization, and gastrocnemius muscle weight in wild-type mice or skeletal muscle-specific KLF15-deficient mice. [Figure 1-2] The expression levels of CXCL10 in patients who required plaster cast immobilization are shown. [Figure 1-3] 1 shows the results of comparing the expression levels of CXCL10 by age in the control group. [Figure 1-4] 1 shows the expression level of CXCL10 in KLF15-overexpressing muscle cells. [Figure 2] The graph shows the changes in the weight of the gastrocnemius and soleus muscles due to immobilization. [Figure 3] Photographs of stained soleus muscle are shown. [Figure 4-1] 1 shows changes in the expression level of CXCL10 following administration of a broad-membrane Ca 2+ channel inhibitor. [Figure 4-2] 1 shows the change in the expression level of CXCL10 after administration of a TRPV2 channel inhibitor. [Figure 5-1] 1 shows changes in the expression level of CXCL10 following administration of an extracellular Ca 2+ chelating agent. [Figure 5-2] 1 shows the change in the expression level of CXCL10 due to administration of an intracellular Ca 2+ chelating agent. [Figure 5-3] 1 shows changes in the expression level of CXCL10 due to administration of a ryanodine receptor inhibitor. [Figure 6] 1 shows changes in the expression level of CXCL10 following administration of a TRPV2 channel inhibitor and a TRPV2 channel activator. DETAILED DESCRIPTION OF THE INVENTION

[0011] Each embodiment included in the present disclosure will be described in further detail below.

[0012] The composition for inhibiting muscle atrophy encompassed by the present disclosure may contain an inhibitor of the expression of CXCL10 (CXC motif chemokine ligand 10). Furthermore, the composition for inhibiting muscle atrophy encompassed by the present disclosure may contain an activator of TRPV2 (Transient receptor potential cation channel subfamily V member 2). These active ingredients can be used alone or in combination of two or more. In this specification, these compositions for inhibiting muscle atrophy may be referred to as "compositions for inhibiting muscle atrophy of the present disclosure."

[0013] CXCL10 (also known as IP-10) is a member of the CXC chemokine family that exerts its biological effects by binding to the CXCR3 receptor and is reported to be secreted from cells in response to IFN-γ. CXCL10 is known to have chemotactic effects on, for example, monocytes, macrophages, T cells, NK cells, and dendritic cells, as well as antitumor activity.

[0014] Examples of CXCL10 expression suppressors include CXCL10 inhibitors, etc. The CXCL10 inhibitors are not particularly limited, as long as they inhibit the activity of CXCL10.

[0015] Examples of CXCL10 inhibitors include CXCL10 neutralizing antibodies, etc. The CXCL10 neutralizing antibodies are not particularly limited as long as they are antibodies that bind to CXCL10 and inhibit the activity of CXCL10.

[0016] Inhibition of CXCL10 activity is confirmed, for example, by assessing the ability to inhibit CXCL10-induced chemotaxis.

[0017] The CXCL10 neutralizing antibody may be a commercially available product or may be produced by a known method. An example of a commercially available product is MAB466 (manufactured by R&D Systems).

[0018] Furthermore, a CXCL10 inhibitor (CXCL10 expression suppressor) may be a nucleic acid molecule capable of inhibiting the activity of CXCL10 by suppressing the expression of the CXCL10 gene. Examples of such nucleic acid molecules include antisense strands, siRNAs, miRNAs, shRNAs, and vectors containing these that target a polynucleotide encoding CXCL10. Gene expression is confirmed by methods known in the art.

[0019] KLF15 is a transcription factor whose gene expression is significantly increased by immobilization or other methods. As shown in the Examples below, increased CXCL10 expression is suppressed in KLF15-deficient mice, suggesting that KLF15 is a factor that controls CXCL10 expression. Therefore, a CXCL10 inhibitor may be a nucleic acid molecule that can inhibit the activity of CXCL10 by suppressing the expression of the KLF15 gene. Examples of such nucleic acid molecules include antisense strands, siRNAs, miRNAs, shRNAs, and vectors containing these that target a polynucleotide encoding KLF15. Gene expression is confirmed by methods known in the art.

[0020] The composition for inhibiting muscle atrophy of the present disclosure may also contain an antagonist of CXCR3, which is a receptor for CXCL10.

[0021] TRPV2 is a nonselective cation channel with high calcium ion permeability that belongs to the Transient Receptor Potential (TRP) superfamily. TRPV2 is known to be activated by heat stimulation above 52°C and mechanical stretching of the cell membrane.

[0022] The TRPV2 activator is not particularly limited as long as it activates TRPV2.

[0023] Activation of TRPV2 is confirmed, for example, by assessing the ability to promote TRPV2-mediated calcium uptake.

[0024] Examples of TRPV2 activators include probenecid, 2-aminoethyl diphenylborinate, lysophosphatidylcholine, IGF-1 (insulin-like growth factor 1), cannabidiol, and the like. The TRPV2 activator may be a natural or synthetic product, and is not particularly limited to a product purified from a natural product or commercially available. If it is a synthetic product, it can be synthesized by a known method.

[0025] The content of the CXCL10 expression inhibitor and / or TRPV2 activator in the composition for inhibiting muscle atrophy of the present disclosure is not particularly limited and can be appropriately set within the range of, for example, 0.01 to 100% by mass, and may be, for example, 0.05 to 99% by mass.

[0026] The muscle atrophy-inhibiting composition of the present disclosure contains the active ingredient described above and may further contain other ingredients. Examples of such other ingredients include pharmaceutically acceptable bases, carriers, and additives (e.g., solvents, dispersants, emulsifiers, buffers, stabilizers, excipients, binders, disintegrants, lubricants, antioxidants, preservatives, coating agents, colorants, and other drugs such as gastric mucosa protectants). These ingredients may be used alone or in combination of two or more.

[0027] The form of the composition for inhibiting muscle atrophy of the present disclosure is not particularly limited, and examples include injections, tablets, pills, capsules, powders, fine granules, granules, liquids, troches, jellies, plasters, extracts, suppositories, suspensions, tinctures, ointments, poultices, nasal drops, inhalants, liniments, lotions, aerosols, and the like.

[0028] The composition for inhibiting muscle atrophy of the present disclosure can be prepared by a conventional method by combining the above-mentioned active ingredient with other ingredients as needed.

[0029] Although not intending to be interpreted in a limiting manner, the composition for inhibiting muscle atrophy comprising the CXCL10 expression inhibitor of the present disclosure can inhibit muscle atrophy by inhibiting the activity of CXCL10 with the CXCL10 expression inhibitor.

[0030] Furthermore, without wishing to be limited in any way, the composition for inhibiting muscle atrophy comprising the TRPV2 activator of the present disclosure promotes calcium uptake from the extracellular space into the cells via TRPV2 by the TRPV2 activator. As shown in the Examples described below, inhibition of calcium uptake into the cells via TRPV2 increases the expression of CXCL10. Therefore, the TRPV2 activator promotes calcium uptake into the cells via TRPV2, suppressing the expression of CXCL10, thereby suppressing muscle atrophy.

[0031] Examples of muscles include voluntary muscles (skeletal muscles) and involuntary muscles (cardiac muscles, smooth muscles). Of these, voluntary muscles (skeletal muscles) are preferred.

[0032] Examples of muscle atrophy include disuse muscle atrophy, myogenic muscle atrophy, neurogenic muscle atrophy, etc. Among these, disuse muscle atrophy is preferred, and disuse muscle atrophy caused by immobility and / or inactivity is more preferred. As used herein, "immobility" refers to a state in which movement of a joint within its range of motion is impossible, such as when a joint is fixed, and "immobility" refers to a state in which muscle movement is impossible, such as when a nerve is severed or a muscle is paralyzed.

[0033] The dosage of the composition for inhibiting muscle atrophy of the present disclosure is not particularly limited and is determined depending on the age, weight, sex, severity of symptoms, administration method, etc. of the subject to be administered.

[0034] Methods for administering the composition for inhibiting muscle atrophy of the present disclosure include, for example, oral administration and parenteral (e.g., intravenous, intraarterial, intramuscular, subcutaneous, peritoneal, rectal, transdermal, topical, etc.) administration.

[0035] The subject of administration of the muscle atrophy-inhibiting composition of the present disclosure is preferably a mammal. This may include not only humans but also non-human mammals. Examples of such subjects include humans with or suspected of having muscle atrophy; humans with or suspected of having sarcopenia (age-related muscle wasting); humans with or suspected of having myogenic muscle atrophy such as muscular dystrophy; humans with or suspected of having neurogenic muscle atrophy such as amyotrophic lateral sclerosis (ALS); humans with or suspected of having drug-induced muscle atrophy such as steroids; humans with or suspected of having muscle atrophy due to endocrine disorders such as Cushing's syndrome; humans with or suspected of having muscle atrophy due to cancer or a wasting disease; humans with or suspected of having muscle atrophy due to chronic kidney disease; humans with or suspected of having muscle atrophy due to chronic liver disease; humans with or suspected of having muscle atrophy due to chronic heart failure; and humans with or suspected of having muscle atrophy due to a mental disorder such as depression. Examples of non-human mammals include mammals kept as pets, livestock, laboratory animals, etc. Examples of such non-human mammals include dogs, cats, monkeys, cows, horses, sheep, goats, pigs, rabbits, mice, rats, camels, and llamas.

[0036] The composition for inhibiting muscle atrophy of the present disclosure can inhibit muscle atrophy. Therefore, the composition can be suitably used for treating or preventing diseases accompanied by muscle atrophy. In this specification, the composition may be referred to as the "composition for treatment or prevention of the present disclosure."

[0037] For the therapeutic or preventive composition of the present disclosure, the above description of the "composition for inhibiting muscle atrophy of the present disclosure" can be cited.

[0038] Examples of diseases accompanied by muscle atrophy include sarcopenia (age-related muscle weakness); myogenic muscle atrophy such as muscular dystrophy; neurogenic muscle atrophy such as amyotrophic lateral sclerosis (ALS); endocrine diseases accompanied by muscle atrophy such as Cushing's syndrome; cancer and wasting diseases accompanied by muscle atrophy; chronic kidney disease accompanied by muscle atrophy; chronic liver disease accompanied by muscle atrophy; chronic heart failure accompanied by muscle atrophy; and psychiatric disorders such as depression accompanied by muscle atrophy.

[0039] The present disclosure also encompasses a method for screening for an active ingredient for suppressing muscle atrophy. In this specification, this method may be referred to as the "screening method of the present disclosure."

[0040] The screening method of the present disclosure preferably uses a decrease in the expression level of the CXCL10 gene as an index.

[0041] The expression level of the CXCL10 gene can be measured, for example, by adding a test substance to cells expressing the CXCL10 gene and performing PCR etc. Preferably, the screening method of the present disclosure includes the steps of adding a test substance to cells expressing the CXCL10 gene and measuring the expression level of the CXCL10 gene in the cells.

[0042] The screening method of the present disclosure may include a step of selecting, as an active ingredient for suppressing muscle atrophy, a component that reduces the expression level of the CXCL10 gene when the test component is added compared to when the test component is not added.The screening method of the present disclosure may also include a step of comparing the test component with a component (control) that reduces the expression level of the CXCL10 gene, and selecting, as an active ingredient for suppressing muscle atrophy, a test component that is confirmed to reduce the expression level of the CXCL10 gene to the same extent as the control.

[0043] As shown in the examples below, CXCL10 expression inhibitors (more specifically, CXCL10 neutralizing antibodies) can inhibit muscle atrophy, such as by inhibiting a decrease in muscle weight in the gastrocnemius and soleus muscles, a decrease in muscle fiber diameter, or an infiltration of inflammatory cells.Therefore, according to the screening method disclosed herein, it is possible to screen for active ingredients for inhibiting muscle atrophy using a decrease in the expression level of the CXCL10 gene as an indicator.

[0044] In this specification, the term "comprising" includes "consisting essentially of" and "consisting of." Furthermore, the present disclosure encompasses all arbitrary combinations of the constituent elements described in this specification.

[0045] Furthermore, the various characteristics (properties, structures, functions, etc.) described in each embodiment of the present disclosure above may be combined in any way to specify the subject matter encompassed by the present disclosure, i.e., the present disclosure encompasses all subject matter consisting of any combination of the combinable characteristics described herein. [Example]

[0046] The contents of the present disclosure will be specifically explained using the following examples. However, the present disclosure is not limited to these examples. In the following, unless otherwise specified, experiments were performed under atmospheric pressure and room temperature conditions. Furthermore, unless otherwise specified, "%" means "% by mass."

[0047] An immobilized mouse model was created by immobilizing both lower limbs of male mice (10 weeks old) in plastic casts under general anesthesia. After 3 days of immobilization, the mice were sacrificed, and skeletal muscles were collected and immediately frozen in liquid nitrogen. Total RNA was extracted using the RNeasy Mini kit (Qiagen), and real-time quantitative PCR was performed using a Real-Time PCR system (Applied Biosystems) to analyze mRNA expression in muscle tissue. The expression levels of CXCL10 and KLF15 in each sample were normalized to the expression level of the endogenous control, 36B4. The results are shown in Figure 1-1.

[0048] In the gastrocnemius muscle of wild-type mice (WT), immobilization (IM) increased CXCL10 mRNA expression approximately fourfold compared to control ([Figure 1-1] (A)). On the other hand, immobilization significantly increased KLF15 mRNA expression (Fig. 1B). In skeletal muscle-specific KLF15-deficient mice (M-KLF15KO, generated by crossing KLF15-floxed mice with MLC1f-Cre mice), immobilization-induced increases in CXCL10 mRNA expression were significantly suppressed (n = 6, *P < 0.05, NS; not significant, 2-way ANOVA with Bonferroni post-hoc test) (Fig. 1A). Furthermore, we measured the gastrocnemius muscle weight after immobilization in wild-type and skeletal muscle-specific KLF15-deficient mice. While immobilization significantly reduced gastrocnemius muscle weight in wild-type mice, immobilization did not reduce gastrocnemius muscle weight in skeletal muscle-specific KLF15-deficient mice (Fig. 1C).

[0049] In a collaborative study with the Department of Orthopedic Surgery, Kobe University Hospital (approved by the Medical Ethics Committee of the Kobe University Graduate School of Medicine, June 14, 2018, approval number: 180059), skeletal muscle biopsies were performed during repair surgery under general anesthesia in patients who required plaster cast immobilization for fractures (IM, 21 patients, immobilization period: 6.5 ± 3.6 days). Skeletal muscle biopsies were also performed at the time of nail removal more than six months after repair surgery to obtain control muscle samples (Control, 22 patients). Total RNA was extracted from human skeletal muscle tissue using the method described above, and CXCL10 mRNA expression was analyzed by real-time quantitative PCR. The results are shown in Figures 1-2.

[0050] In the immobilized group, CXCL10 mRNA expression increased more than two-fold compared to the control group (*P < 0.05, Unpaired t test).

[0051] Human skeletal muscle biopsy samples from the control group were stratified by age (<60 years: 13 cases, 48.2 ± 10.4 years old; ≥60 years: 9 cases, 72.7 ± 7.7 years old) and analyzed. The results are shown in Figures 1-3.

[0052] CXCL10 mRNA expression was significantly increased in patients aged 60 years or older compared with those under 60 years old (*P < 0.05, Unpaired t test).

[0053] C2C12 mouse myoblasts were maintained in a growth medium (Dulbecco's modified Eagle's medium (DMEM), 10% heat-inactivated fetal bovine serum, 1% penicillin-streptomycin) in an incubator (37°C, 95% air, 5% CO2). After myoblasts reached 100% confluence, the culture medium was changed to differentiation medium (DMEM, 2% horse serum, 1% penicillin-streptomycin) to induce differentiation. After 4 days or more, myotubes were fully differentiated before use. C2C12 myotubes were infected with adenovirus carrying mouse KLF15 cDNA (multiplicity of infection, plaque-forming units per cell) of 30 and harvested 48 hours later. Total RNA was extracted as described above. The results of real-time quantitative PCR analysis are shown in Figures 1-4.

[0054] Overexpression of KLF15 (Ad-KLF15) significantly increased CXCL10 mRNA expression (n = 6, *P < 0.05, Unpaired t test).

[0055] Mice were intraperitoneally administered 0.1 mg of a CXCL10 neutralizing antibody (MAB466, R&D Systems) or normal rat IgG (6-001-F, R&D Systems) three days before cast immobilization. After 10 days of immobilization, the mice were sacrificed and their body and skeletal muscle weights were measured. The results are shown in Figure 2.

[0056] Compared with the control group (Control), the immobilization group (IM + IgG) showed a decrease in the weight of the gastrocnemius and soleus muscles per body weight, whereas the immobilization-induced muscle weight loss was significantly suppressed in the CXCL10 neutralizing antibody-treated group (IM + Anti-CXCL10) (n = 10, *P < 0.05, 2-way ANOVA with Bonferroni post-hoc test).

[0057] The mouse soleus muscle collected in Figure 2 was immersed in formalin, embedded in paraffin, and sectioned at its largest cross section, which was then stained with HE. The results are shown in Figure 3.

[0058] Compared to the control group (Control), the immobilization group (IM + IgG) showed a decrease in muscle fiber diameter and infiltration of inflammatory cells, whereas the immobilization-induced decrease in muscle fiber diameter and infiltration of inflammatory cells were suppressed in the CXCL10 neutralizing antibody administration group (IM + Anti-CXCL10).

[0059] Widespread membrane Ca in C2C12 myotubes 2+ The channel inhibitor SKF-96365 (50 μM) was added, and the cells were harvested 6 hours later and total RNA was extracted as described above. The results of real-time quantitative PCR analysis are shown in Figure 4-1.

[0060] Wide-area membrane Ca 2+ Administration of the channel inhibitor significantly increased CXCL10 mRNA expression (n = 6, *P < 0.05, Unpaired t test).

[0061] C2C12 myotubes were treated with the TRPV2 channel inhibitor tranilast (75 μM), and after 6 hours, the cells were harvested and total RNA was extracted as described above. The results of real-time quantitative PCR analysis are shown in Figure 4-2.

[0062] Administration of a TRPV2 channel inhibitor significantly increased CXCL10 mRNA expression (n = 6, *P < 0.05, Unpaired t test).

[0063] Extracellular Ca concentration in C2C12 myotubes 2+ The chelating agent EGTA (0.1 mM) was added, and after 3 hours the cells were harvested and total RNA was extracted using the method described above. The results of real-time quantitative PCR analysis are shown in Figure 5-1.

[0064] Extracellular Ca 2+Administration of chelating agents significantly increased CXCL10 mRNA expression (n = 8, *P < 0.05, Unpaired t test). 2+ Chelating agents release extracellular Ca 2+ As the concentration of Ca decreases, Ca flows into the cell from outside. 2+ Decreased intracellular Ca 2+ It was suggested that the decrease in concentration significantly increased CXCL10 mRNA expression.

[0065] Intracellular Ca concentration in C2C12 myotubes 2+ The chelating agent BAPTA-AM (10 μM) was added, and the cells were harvested 6 hours later and total RNA was extracted using the method described above. The results of real-time quantitative PCR analysis are shown in Figure 5-2.

[0066] Intracellular Ca 2+ Administration of chelating agents did not alter CXCL10 mRNA expression (n = 6, NS; not significant, Unpaired t test).

[0067] C2C12 myotube cells were treated with the ryanodine receptor inhibitor dantrolene (20 μM), and after 6 hours, the cells were harvested and total RNA was extracted as described above. The results of real-time quantitative PCR analysis are shown in Figure 5-3. The addition of the ryanodine receptor inhibitor inhibited calcium release from the sarcoplasmic reticulum into the cell.

[0068] Ryanodine receptor inhibitors did not alter CXCL10 mRNA expression (n = 9, NS; not significant, Unpaired t test). This suggests that the increase in CXCL10 mRNA is due to the inhibition of calcium influx from the extracellular space into the cell via TRPV2 (a plasma membrane Ca channel).

[0069] C2C12 myotubes were treated with the TRPV2 channel activator LPC (30 μM) and the TRPV2 channel inhibitor Tranilast (75 μM). After 6 hours, the cells were harvested and total RNA was extracted as described above. The results of real-time quantitative PCR analysis are shown in Figure 6 (n = 6).

[0070] It was confirmed that administration of a TRPV2 channel inhibitor significantly increased CXCL10 mRNA expression, whereas administration of LPC, a TRPV2 channel activator, decreased CXCL10 mRNA expression.

Claims

1. A composition for inhibiting disuse muscle atrophy, comprising: Contains a CXCL10 expression inhibitor as an active ingredient, A composition for suppressing disuse muscle atrophy, wherein the CXCL10 expression inhibitor is at least one selected from the group consisting of a neutralizing antibody of CXCL10; an antisense strand, siRNA, miRNA, shRNA, and a vector comprising at least one of these, targeting a polynucleotide encoding CXCL10; and an antisense strand, siRNA, miRNA, shRNA, and a vector comprising at least one of these, targeting a polynucleotide encoding KLF15.

2. The composition for suppressing disuse muscle atrophy described in claim 1, wherein the CXCL10 expression inhibitor is at least one selected from the group consisting of a neutralizing antibody of CXCL10; and an antisense strand targeting a polynucleotide encoding CXCL10, siRNA, miRNA, shRNA, and a vector containing at least one of these.

3. The composition for suppressing disuse muscle atrophy according to claim 1 or 2, wherein the CXCL10 expression inhibitor is a CXCL10 neutralizing antibody.

4. A composition for treating or preventing a disease accompanied by disuse muscle atrophy, Contains a CXCL10 expression inhibitor as an active ingredient, A composition for treating or preventing a disease accompanied by disuse muscle atrophy, wherein the CXCL10 expression inhibitor is at least one selected from the group consisting of a neutralizing antibody of CXCL10; an antisense strand, siRNA, miRNA, shRNA, and a vector comprising at least one of these, targeting a polynucleotide encoding CXCL10; and an antisense strand, siRNA, miRNA, shRNA, and a vector comprising at least one of these, targeting a polynucleotide encoding KLF15.

5. A composition for treating or preventing a disease accompanied by disuse muscle atrophy as described in claim 4, wherein the CXCL10 expression inhibitor is at least one selected from the group consisting of a neutralizing antibody of CXCL10; and an antisense strand targeting a polynucleotide encoding CXCL10, siRNA, miRNA, shRNA, and a vector containing at least one of these.

6. The composition for treating or preventing a disease accompanied by disuse muscle atrophy according to claim 5 , wherein the CXCL10 expression inhibitor is a CXCL10 neutralizing antibody.

7. The composition according to any one of claims 1 to 6, wherein the disuse muscle atrophy is atrophy of skeletal muscles.

8. The composition according to any one of claims 1 to 7, for use in subjects aged 60 years or older.

9. A method for screening for an active ingredient for suppressing disuse muscle atrophy, using a decrease in the expression level of the CXCL10 gene as an indicator.

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