OBJECTIVE: To assess the impacts of electroacupuncture (EA) on the gait, oxidative stress, inflammatory reaction, and protein degradation in the rats of denervated skeletal muscle atrophy, and explore the potential mechanism of EA for alleviating denervated skeletal muscle atrophy. METHODS: Forty male SD rats, 8 weeks old, were randomly assigned to a sham-surgery group, a model group, an EA group, and a p38 MAPK inhibitor group, with 10 rats in each group. The right sciatic nerve was transected to establish a rat model of denervated skeletal muscle atrophy in the model group, the EA group and the p38 MAPK inhibitor group. In the sham-surgery group, the nerve was exposed without transection. One day after successful modeling, the rats in the EA group received EA at "Huantiao" (GB30) and "Zusanli" (ST36) on the right side, using a continuous wave with a frequency of 2 Hz and current intensity of 1 mA, for 15 min in each session, EA was delivered once a day, 6 times a week. In the p38 MAPK inhibitor group, the rats received the intraperitoneal injection with SB203580 (5 mg/kg), once a day, 6 times a week. The intervention was composed of 3 weeks in each group. After the intervention completion, the CatWalk XT 10.6 animal gait analysis system was used to record the gait parameters of rats. The wet weight ratio of the gastrocnemius muscle was calculated after the sample collected. Using HE staining, the fiber morphology and cross-sectional area of the gastrocnemius muscle were observed; ELISA was employed to measure the content of interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α in the gastrocnemius muscle; the biochemical hydroxyamine method was adopted to detect the content of superoxide dismutase (SOD) and malondialdehyde (MDA) in the gastrocnemius muscle; with immunohistochemistry and Western blot used, the expression of p38 mitogen-activated protein kinase (p38 MAPK), phosphorylated (p)-p38 MAPK, muscle atrophy F-box gene (Atrogin-1), muscle RING finger 1 (Murf-1), nuclear factor E2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) was detected in the gastrocnemius muscle. RESULTS: Compared to the sham-surgery group, in the model group, the standing duration, the swing time and the step cycle were increased (P<0.001), the footprint area of the maximum contact time, the print area, the average intensity of the maximum contact time, the average intensity, the swing speed, and the step length were decreased (P<0.001); the wet weight ratio of gastrocnemius muscle and fiber cross-sectional area were reduced (P<0.001); the content of IL-6, IL-1β, TNF-α and MDA in gastrocnemius muscle elevated (P<0.001), and that of SOD reduced (P<0.001); the positive and protein expression of p-p38 MAPK, Atrogin-1 and Murf-1 elevated (P<0.001) and that of Nrf2 and HO-1 dropped (P<0.001). When compared with the model group, in the EA group and the p38 MAPK inhibitor group, the standing duration, the swing time and the step cycle decreased (P<0.01), the footprint area of the maximum contact time, the print area, the average intensity of the maximum contact time, the average intensity, the swing speed, and the step length increased (P<0.01); the wet weight ratio of gastrocnemius muscle and fiber cross-sectional area were improved (P<0.01, P<0.05); the content of IL-6, IL-1β, TNF-α and MDA in gastrocnemius muscle dropped (P<0.05, P<0.01), and that of SOD elevated (P<0.01, P<0.05); the positive and protein expression of p-p38 MAPK, Atrogin-1 and Murf-1 dropped (P<0.01, P<0.05) and that of Nrf2 and HO-1 increased (P<0.01, P<0.05). CONCLUSION Electroacupuncture may alleviate skeletal muscle atrophy in denervated skeletal muscle atrophy rats by mediating the p38 MAPK activity, thereby suppressing oxidative stress, inflammatory reaction, and protein degradation.
Animals ; Electroacupuncture ; Male ; Rats ; p38 Mitogen-Activated Protein Kinases/genetics* ; Rats, Sprague-Dawley ; Muscular Atrophy/metabolism* ; Muscle, Skeletal/metabolism* ; Humans ; Signal Transduction ; Superoxide Dismutase/genetics* ; Tumor Necrosis Factor-alpha/genetics* ; Oxidative Stress ; MAP Kinase Signaling System ; Acupuncture Points

This study aims to explore the role and mechanism of CXC chemokine receptor 3 (CXCR3) in cisplatin-induced skeletal muscle atrophy. Wild-type mice were divided into two groups: cisplatin group and control group (treated by normal saline). The results showed that, compared to the control group, the expression levels of CXCR3 mRNA and protein were significantly up-regulated in the skeletal muscle of the cisplatin group, suggesting that CXCR3 may play an important role in the model of cisplatin-induced skeletal muscle atrophy. To further investigate its role and potential mechanisms, CXCR3 knockout mice and wild-type mice were treated with cisplatin to induce skeletal muscle atrophy. The results revealed that CXCR3 knockout not only failed to alleviate cisplatin-induced skeletal muscle atrophy, but also further reduced body weight, skeletal muscle mass, and muscle fiber cross-sectional area. Further analysis showed that, in the cisplatin-induced muscle atrophy model, CXCR3 knockout significantly up-regulated the expression levels of E3 ubiquitin ligases in skeletal muscle and down-regulated the expression levels of myogenic regulatory factors. To explore the molecular mechanism by which CXCR3 gene deletion exacerbated cisplatin-induced skeletal muscle atrophy, transcriptomic sequencing was performed on the atrophied skeletal muscles of wild-type and CXCR3 knockout mice. The results showed that, compared to wild-type mice, 14 genes were significantly up-regulated and 12 genes were significantly down-regulated in the skeletal muscle of CXCR3 knockout mice. Gene set enrichment analysis (GSEA) revealed a significant enrichment of genes related to fatty acid β-oxidation. Quantitative real-time PCR validation results were consistent with the transcriptomic sequencing results. These findings suggest that CXCR3 may counteract cisplatin-induced skeletal muscle atrophy by up-regulating E3 ubiquitin ligases, down-regulating myogenic regulatory factors, and enhancing the recruitment of fatty acid β-oxidation-related genes.
Animals ; Cisplatin/adverse effects* ; Muscular Atrophy/physiopathology* ; Mice ; Receptors, CXCR3/metabolism* ; Ubiquitin-Protein Ligases/metabolism* ; Mice, Knockout ; Oxidation-Reduction ; Fatty Acids/metabolism* ; Muscle, Skeletal/metabolism* ; Mice, Inbred C57BL ; Male

The maintenance of skeletal muscle quality involves various signal pathways that interact with each other. Under normal physiological conditions, these intersecting signal pathways regulate and coordinate the hypertrophy and atrophy of skeletal muscles, balancing the protein synthesis and degradation of muscle. When the total rate of protein synthesis exceeds that of protein degradation, the muscle gradually becomes enlarged, while when the total rate of protein synthesis is lower than that of protein degradation, the muscle shrinks. Myocyte atrophy mainly involves two protein degradation pathways, namely ubiquitin-proteasome and autophagy-lysosome. Protein degradation pathway is activated during muscle atrophy, resulting in the loss of muscle mass. Muscle atrophy can occur under various conditions such as malnutrition, aging and cachexia. Skeletal muscle atrophy caused by orthopedic diseases mainly includes disuse muscular atrophy caused by fracture and denervation muscular atrophy. The signal pathways that control and coordinate protein synthesis and degradation in skeletal muscle include insulin-like growth factor 1 (IGF1)-Akt-mammalian target of rapamycin (mTOR), myostatin-activin A-Smad, G protein α inhibitory peptide 2 (Gαi2)-PKC, nuclear factor κB (NF-κB), ectodysplasin A2 receptor (EDA2R)-NF-κB inducing kinase (NIK) and mitogen-activated protein kinase (MAPK) pathways. This paper provides a comprehensive review of the protein degradation pathways in skeletal muscle atrophy and the associated signal pathways regulating protein degradation in muscular atrophy.
Humans ; Muscular Atrophy/etiology* ; Muscle, Skeletal/pathology* ; Signal Transduction ; Animals ; Insulin-Like Growth Factor I/metabolism* ; Myostatin/physiology* ; TOR Serine-Threonine Kinases/metabolism* ; Autophagy/physiology* ; NF-kappa B/metabolism* ; Proteolysis ; Proteasome Endopeptidase Complex/physiology*

Hypoxia inducible factor-1α (HIF-1α), as a hypoxia inducible factor, affects women's reproductive function by regulating the development and excretion of follicles. HIF-1α induces glycolysis and autophagy in the granule cells by promoting oocyte development, regulating the secretion of related angiogenic factors, and improving follicle maturity. In addition, HIF-1α promotes the process of luteinization of follicular vesicles, maintains luteal function, and finally completes physiological luteal atrophy through cumulative oxidative stress. Dysfunction of HIF-1α will cause a series of pathological consequences, such as angiogenesis defect, energy metabolism abnormality, excessive oxidative stress and dysregulated autophagy and apoptosis, resulting in ovulation problem and infertility. This article summarizes the previous studies on the regulation of follicle development and excretion and maintenance of luteal function and structural atrophy by HIF-1α. We also describe the effective intervention mechanism of related drugs or bioactive ingredients on follicular dysplasia and ovulation disorders through HIF-1α, in order to provide a systematic and in-depth insights for solving ovulation disorder infertility.
Female ; Humans ; Atrophy/metabolism* ; Hypoxia ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Infertility/metabolism* ; Ovarian Follicle ; Ovulation

BACKGROUND: Insufficient cerebral perfusion is suggested to play a role in the development of Alzheimer disease (AD). However, there is a lack of direct evidence indicating whether hypoperfusion causes or aggravates AD pathology. We investigated the effect of chronic cerebral hypoperfusion on AD-related pathology in humans. METHODS: We enrolled a group of cognitively normal patients (median age: 64 years) with unilateral chronic cerebral hypoperfusion. Regions of interest with the most pronounced hypoperfusion changes were chosen in the hypoperfused region and were then mirrored in the contralateral hemisphere to create a control region with normal perfusion. 11C-Pittsburgh compound-positron emission tomography standard uptake ratios and brain atrophy indices were calculated from the computed tomography images of each patient. RESULTS: The median age of the 10 participants, consisting of 4 males and 6 females, was 64 years (47-76 years). We found that there were no differences in standard uptake ratios of the cortex (volume of interest [VOI]: P = 0.721, region of interest [ROI]: P = 0.241) and grey/white ratio (VOI: P = 0.333, ROI: P = 0.445) and brain atrophy indices (Bicaudate, Bifrontal, Evans, Cella, Cella media, and Ventricular index, P > 0.05) between the hypoperfused regions and contralateral normally perfused regions in patients with unilateral chronic cerebral hypoperfusion. CONCLUSION Our findings suggest that chronic hypoperfusion due to large vessel stenosis may not directly induce cerebral β-amyloid deposition and neurodegeneration in humans.
Aged ; Alzheimer Disease/pathology* ; Amyloid beta-Peptides/metabolism* ; Arteries ; Atrophy ; Brain/metabolism* ; Cerebral Cortex/metabolism* ; Cerebrovascular Circulation ; Constriction, Pathologic/pathology* ; Female ; Humans ; Magnetic Resonance Imaging/methods* ; Male ; Middle Aged ; Positron-Emission Tomography/methods*

This study aims to investigate the effect of modified Danggui Shaoyao Powder on the suppressor of cytokine signaling 3(SOCS3)/Toll-like receptor 4(TLR4) signaling pathway in gastric tissue of rats with chronic atrophic gastritis(CAG).Sixty SPF-grade SD rats were randomly assigned into the normal group, model group, Moluo Pills group, and high-, medium-, and low-dose groups of modified Danggui Shaoyao Powder.The rats in other groups except the normal group were treated with N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) to establish the CAG model.After 12 weeks of modeling, the rats in each group were administrated with corresponding drugs by gavage for 8 weeks.After the last administration, the histopathological changes of rat gastric mucosa were observed via hematoxylin-eosin(HE) staining.The serum levels of IL-6, TNF-α, and CRP were determined by enzyme-linked immunosorbent assay(ELISA).The mRNA levels of SOCS3 and TLR4 were determined by real-time PCR.The protein levels of SOCS3, TLR4, JAK2, p-JAK2, STAT3, and p-STAT3 in rat gastric tissue were measured by Western blot.Immunohistochemical method was employed to determine the protein levels of NF-κB, MyD88, NLRP3, Bcl-2, Bax, and Bad in rat gastric tissue.The results showed that modified Danggui Shaoyao Powder alleviated gastric mucosal atrophy of rats, significantly lowered the levels of IL-6, TNF-α, and CRP in rat serum, up-regulated the mRNA level of SOCS3, and down-regulated the mRNA level of TLR4 in rat gastric tissue.Furthermore, modified Danggui Shaoyao Powder up-regulated the protein level of SOCS3, down-regulated the protein levels of TLR4, p-JAK2, p-STAT3, NF-κB, MyD88, NLRP3, Bax, and Bad, and promoted the expression of Bcl-2 protein.Therefore, modified Danggui Shaoyao Powder may mitigate the gastric mucosal atrophy of rats by regulating the SOCS3/TLR4 signaling pathway.
Animals ; Atrophy ; Gastritis, Atrophic/genetics* ; Interleukin-6/metabolism* ; Myeloid Differentiation Factor 88/metabolism* ; NF-kappa B/metabolism* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Powders ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Suppressor of Cytokine Signaling 3 Protein/metabolism* ; Toll-Like Receptor 4/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; bcl-2-Associated X Protein/metabolism*

OBJECTIVE: To investigate the effects of Bax inhibitor 1 (BI- 1) and optic atrophy protein 1 (OPA1) on vascular calcification (VC). METHODS: Mouse models of VC were established in ApoE-deficient (ApoE^-/-) diabetic mice by high-fat diet feeding for 12 weeks followed by intraperitoneal injections with N^ε-carboxymethyl-lysine for 16 weeks. ApoE^-/- mice (control group), ApoE^-/- diabetic mice (VC group), ApoE^-/- diabetic mice with BI-1 overexpression (VC + BI-1^TG group), and ApoE^-/- diabetic mice with BI-1 overexpression and OPA1 knockout (VC+BI-1^TG+OPA1^-/- group) were obtained for examination of the degree of aortic calcification using von Kossa staining. The changes in calcium content in the aorta were analyzed using ELISA. The expressions of Runt-related transcription factor 2 (RUNX2) and bone morphogenetic protein 2 (BMP-2) were detected using immunohistochemistry, and the expression of cleaved caspase-3 was determined using Western blotting. Cultured mouse aortic smooth muscle cells were treated with 10 mmol/L β-glycerophosphate for 14 days to induce calcification, and the changes in BI-1 and OPA1 protein expressions were examined using Western blotting and cell apoptosis was detected using TUNEL staining. RESULTS: ApoE^-/- mice with VC showed significantly decreased expressions of BI-1 and OPA1 proteins in the aorta (P=0.0044) with obviously increased calcium deposition and expressions of RUNX2, BMP-2 and cleaved caspase-3 (P= 0.0041). Overexpression of BI-1 significantly promoted OPA1 protein expression and reduced calcium deposition and expressions of RUNX2, BMP-2 and cleaved caspase-3 (P=0.0006). OPA1 knockdown significantly increased calcium deposition and expressions of RUNX2, BMP-2 and cleaved caspase-3 in the aorta (P=0.0007). CONCLUSION BI-1 inhibits VC possibly by promoting the expression of OPA1, reducing calcium deposition and inhibiting osteogenic differentiation and apoptosis of the vascular smooth muscle cells.
Animals ; Apolipoproteins E/metabolism* ; Calcium/metabolism* ; Caspase 3/metabolism* ; Cells, Cultured ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Diabetes Mellitus, Experimental/pathology* ; GTP Phosphohydrolases/metabolism* ; Membrane Proteins/metabolism* ; Mice ; Mice, Knockout ; Muscle, Smooth, Vascular/pathology* ; Myocytes, Smooth Muscle/pathology* ; Optic Atrophy, Autosomal Dominant/pathology* ; Osteogenesis ; Vascular Calcification/pathology* ; bcl-2-Associated X Protein/metabolism*

OBJECTIVE: To investigate the therapeutic effects of massage on denervated skeletal muscle atrophy in rats and its mechanism. METHODS: Forty-eight male SD rats were randomly divided into model group (n=24) and massage group (n=24). Gastrocnemius muscle atrophy model was established by transecting the right tibial nerve of rat. On the second day after operation, the gastrocnemius muscle of the rats in the massage group was given manual intervention and the model group was not intervened. Six rats were sacrificed at the four time points of 0 d, 7 d, 14 d and 21 d. The gastrocnemius of the rats were obtained and measured the wet mass ratio after weighing. Cross-sectional area and diameter of the muscle fiber were measured after HE staining. The relative expressions of miR-23a, Akt, MuRF1 and MAFbx mRNA were tested with qPCR. RESULTS: Compared with 0 d, the wet weight ratio, cross-sectional area and diameter of gastrocnemius muscle showed a progressive decline in the model group and massage group. The wet weight ratio, cross-sectional area and diameter of gastrocnemius muscle in the massage group were higher than those in the model group on 7 d, 14 d and 21 d (P＜0.05, P＜0.01). Compared with 0 d, the expressions of MuRF1, MAFbx and Akt mRNA were increased first and then were decreased in the model group and massage group. The expression of MuRF1 mRNA in massage group was lower than that in model group on 7 d and 21 d (P＜0.05, P＜0.01). The expression of MAFbx mRNA in massage group was lower than that in model group on 7 d, 14 d and 21 d (P＜0.01, P＜0.05, P＜0.01). The expression of Akt mRNA in massage group was higher than that in model group on 7 d, 14 d and 21 d (P＜0.05, P＜0.01). Compared with 0 d, the expression of miR-23a mRNA was increased in the model group and massage group on 21 d, and the expression of miR-23a mRNA in massage group was higher than that in model group (P＜ 0.05). CONCLUSION Massage can delay the atrophy of denervated skeletal muscle. The mechanism may be related to up-regulation of the expression of miR-23a and Akt mRNA, down-regulation of the expressions of MuRF1 and MAFbx mRNA, inhibition of protein degradation rate, and reduction of skeletal muscle protein degradation.
Animals ; Male ; Massage ; MicroRNAs ; metabolism ; Muscle Fibers, Skeletal ; Muscle Proteins ; metabolism ; Muscle, Skeletal ; physiopathology ; Muscular Atrophy ; therapy ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Rats, Sprague-Dawley ; SKP Cullin F-Box Protein Ligases ; metabolism ; Tripartite Motif Proteins ; metabolism ; Ubiquitin-Protein Ligases ; metabolism

The clinical treatment of joint contracture due to immobilization remains difficult. The pathological changes of muscle tissue caused by immobilization-induced joint contracture include disuse skeletal muscle atrophy and skeletal muscle tissue fibrosis. The proteolytic pathways involved in disuse muscle atrophy include the ubiquitin-proteasome-dependent pathway, caspase system pathway, matrix metalloproteinase pathway, Ca-dependent pathway and autophagy-lysosomal pathway. The important biological processes involved in skeletal muscle fibrosis include intermuscular connective tissue thickening caused by transforming growth factor-β1 and an anaerobic environment within the skeletal muscle leading to the induction of hypoxia-inducible factor-1α. This article reviews the progress made in understanding the pathological processes involved in immobilization-induced muscle contracture and the currently available treatments. Understanding the mechanisms involved in immobilization-induced contracture of muscle tissue should facilitate the development of more effective treatment measures for the different mechanisms in the future.
Atrophy ; Autophagy ; Calcium ; metabolism ; Caspases ; metabolism ; Connective Tissue ; metabolism ; pathology ; Contracture ; etiology ; metabolism ; pathology ; therapy ; Fibrosis ; Humans ; Immobilization ; adverse effects ; Joints ; Lysosomes ; metabolism ; Matrix Metalloproteinases ; metabolism ; Muscle, Skeletal ; metabolism ; pathology ; Proteasome Endopeptidase Complex ; metabolism ; Proteolysis ; Signal Transduction ; physiology ; Transforming Growth Factor beta1 ; metabolism ; Ubiquitin ; metabolism

Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is a rare autosomal recessive disorder caused by a defect in the immunoglobulin mu binding protein 2 (IGHMBP2) gene, leading to motor neuron degeneration. We identified an infant with SMARD1 by targeted exome sequencing from a consanguineous Syrian family having a history of recurrent infant deaths. The patient initially presented intrauterine growth retardation, poor sucking, failure to thrive, and respiratory failure at the age of two months, and an inborn error of metabolism was suspected at first. Over a period of one month, the infant showed rapid progression of distal muscular weakness with hand and foot contractures, which were suggestive of neuromuscular disease. Using targeted exome sequencing, the mutation in IGHMBP2 was confirmed, although the first report was normal. Targeted exome sequencing enabled identification of the genetic cause of recurrent mysterious deaths in the consanguineous family. Additionally, it is suggested that a detailed phenotypic description and communication between bioinformaticians and clinicians is important to reduce false negative results in exome sequencing.
Carrier Proteins ; Contracture ; Exome ; Failure to Thrive ; Fetal Growth Retardation ; Foot ; Hand ; Humans ; Immunoglobulins ; Infant Death ; Infant ; Metabolism ; Motor Neurons ; Muscle Weakness ; Muscular Atrophy, Spinal ; Neuromuscular Diseases ; Respiratory Insufficiency