BACKGROUND:Skeletal muscle aging is associated with various chronic diseases.Exercise is considered an important means to delay this process,but the multimechanism regulation of exercise intervention strategies still requires in-depth exploration.OBJECTIVE:To systematically outline the main physiological changes in skeletal muscle aging and explore the multiple mechanisms by which exercise regulates these changes,thereby providing a theoretical basis for basic research and clinical applications.METHODS:By searching databases such as Web of Science,PubMed,Embase,CNKI,WanFang,and VIP,relevant literature from database inception to October 2024 was retrieved by the first author,including original research articles and reviews.The search terms were"skeletal muscle aging,sarcopenia,exercise regulation,physical activity,chronic inflammation,inflammaging,mitochondrial dysfunction,extracellular matrix fibrosis,lipid mediators,satellite cells"in English and Chinese.Literature was screened based on inclusion and exclusion criteria,and the included 95 articles underwent quality assessment and data extraction.RESULTS AND CONCLUSION:(1)The core manifestations of skeletal muscle aging are the decline in muscle mass,strength,and function,closely related to various physiological changes.The decreased protein synthesis capacity and accelerated degradation rate in muscles lead to muscle atrophy and functional decline.Additionally,dysfunction of satellite cells is considered a key factor in the reduced regenerative capacity of muscles.Mitochondrial dysfunction is another important factor leading to muscle fatigue and energy metabolism disorders,directly affecting the metabolic activity and endurance of skeletal muscles.Chronic inflammatory responses and extracellular matrix fibrosis further exacerbate muscle aging.These factors interact synergistically,collectively resulting in skeletal muscle degeneration.(2)Exercise is widely recognized as an important means to delay skeletal muscle aging.Exercise alleviates chronic low-grade inflammatory responses in skeletal muscle by regulating the immune system,increasing the secretion of anti-inflammatory factors,and inhibiting the expression of pro-inflammatory factors,thereby mitigating the damage of inflammation to muscles.Exercise also enhances mitochondrial biogenesis and function,improves the muscle's energy metabolism capacity,and consequently increases endurance and strength.Furthermore,exercise regulates lipid metabolism and the synthesis of lipid mediators,reduces fat accumulation and alleviates fat-induced inflammatory responses,thereby further protecting skeletal muscles.The mechanical stimulation from exercise promotes the remodeling of the extracellular matrix,reduces fibrosis occurrence,and improves muscle structure and function.Additionally,exercise activates satellite cells,enhancing the regenerative capacity of skeletal muscles,especially notable with strength training and high-intensity interval training.(3)Future research should include large-scale,multicenter clinical trials to evaluate the comprehensive effects of long-term exercise interventions on skeletal muscle aging.By analyzing data from genomics,metabolomics,and other fields,exploring individual differences in responses to exercise interventions can provide more precise theoretical bases for personalized exercise strategies.Besides exercise,the impacts of other interventions such as nutritional supplementation and pharmacological treatments on skeletal muscle aging should not be overlooked.Future studies can explore the combined use of exercise with these interventions to achieve more significant effects.

BACKGROUND:Skeletal muscle aging is associated with various chronic diseases.Exercise is considered an important means to delay this process,but the multimechanism regulation of exercise intervention strategies still requires in-depth exploration.OBJECTIVE:To systematically outline the main physiological changes in skeletal muscle aging and explore the multiple mechanisms by which exercise regulates these changes,thereby providing a theoretical basis for basic research and clinical applications.METHODS:By searching databases such as Web of Science,PubMed,Embase,CNKI,WanFang,and VIP,relevant literature from database inception to October 2024 was retrieved by the first author,including original research articles and reviews.The search terms were"skeletal muscle aging,sarcopenia,exercise regulation,physical activity,chronic inflammation,inflammaging,mitochondrial dysfunction,extracellular matrix fibrosis,lipid mediators,satellite cells"in English and Chinese.Literature was screened based on inclusion and exclusion criteria,and the included 95 articles underwent quality assessment and data extraction.RESULTS AND CONCLUSION:(1)The core manifestations of skeletal muscle aging are the decline in muscle mass,strength,and function,closely related to various physiological changes.The decreased protein synthesis capacity and accelerated degradation rate in muscles lead to muscle atrophy and functional decline.Additionally,dysfunction of satellite cells is considered a key factor in the reduced regenerative capacity of muscles.Mitochondrial dysfunction is another important factor leading to muscle fatigue and energy metabolism disorders,directly affecting the metabolic activity and endurance of skeletal muscles.Chronic inflammatory responses and extracellular matrix fibrosis further exacerbate muscle aging.These factors interact synergistically,collectively resulting in skeletal muscle degeneration.(2)Exercise is widely recognized as an important means to delay skeletal muscle aging.Exercise alleviates chronic low-grade inflammatory responses in skeletal muscle by regulating the immune system,increasing the secretion of anti-inflammatory factors,and inhibiting the expression of pro-inflammatory factors,thereby mitigating the damage of inflammation to muscles.Exercise also enhances mitochondrial biogenesis and function,improves the muscle's energy metabolism capacity,and consequently increases endurance and strength.Furthermore,exercise regulates lipid metabolism and the synthesis of lipid mediators,reduces fat accumulation and alleviates fat-induced inflammatory responses,thereby further protecting skeletal muscles.The mechanical stimulation from exercise promotes the remodeling of the extracellular matrix,reduces fibrosis occurrence,and improves muscle structure and function.Additionally,exercise activates satellite cells,enhancing the regenerative capacity of skeletal muscles,especially notable with strength training and high-intensity interval training.(3)Future research should include large-scale,multicenter clinical trials to evaluate the comprehensive effects of long-term exercise interventions on skeletal muscle aging.By analyzing data from genomics,metabolomics,and other fields,exploring individual differences in responses to exercise interventions can provide more precise theoretical bases for personalized exercise strategies.Besides exercise,the impacts of other interventions such as nutritional supplementation and pharmacological treatments on skeletal muscle aging should not be overlooked.Future studies can explore the combined use of exercise with these interventions to achieve more significant effects.

Objective:To investigate the association between blood selenium levels and sex hormones in Chinese men aged 18-79 years.Methods:Data were derived from the China National Human Biomonitoring survey conducted in 2017-2018, with a final sample size of 5 414 men. General demographic characteristics, behavioral habits, and dietary frequency were collected through questionnaires and physical examinations. Fasting blood samples were collected to measure blood lead, serum testosterone, and estradiol levels. Complex sampling linear regression models were used to analyze the associations between blood selenium levels and testosterone, estradiol, and the testosterone/estradiol ratio, adjusting for confounding factors including age, education level, marital status, smoking status, alcohol consumption, seafood intake, soy product intake, protein supplement intake, BMI, and diabetes status.Results:The mean age of the 5 414 participants was (46.85±27.91) years; 4 774 (91.65%) were of Han ethnicity and 4 505 (86.68%) were married. The median ( Q1, Q3) blood selenium concentration in men was 97.80 (80.64, 116.99) μg/L. After adjusting for confounding factors, the complex sampling linear regression model revealed negative associations between blood selenium levels and both testosterone levels and the testosterone/estradiol ratio, with a significant linear trend ( Ptrend<0.05). Compared with the Q1 group, the β (95% CI) values for testosterone in the Q2, Q3, and Q4 groups were -0.02 (-0.06 to 0.02), -0.03 (-0.08 to 0.01), and -0.06 (-0.09 to -0.02), respectively. Similarly, the β (95% CI) values for the testosterone/estradiol ratio in the Q2, Q3, and Q4 groups were -0.01 (-0.03 to 0.02), -0.01 (-0.04 to 0.04), and -0.03 (-0.06 to -0.01), respectively. Subgroup analysis indicated stronger associations between blood selenium levels and testosterone/estradiol levels in non-smoking and obese men (BMI≥28 kg/m2). Conclusion:Blood selenium levels are negatively associated with testosterone levels and the testosterone/estradiol ratio in Chinese adult males.

Ischemic retinopathies (IRs) with neovascularization often severely impair vision and even lead to blindness.Studies have shown that long non-coding RNA (lncRNA) MALAT1 is co-expressed with protein-coding genes that regulate retinal cell development.Recent studies have also confirmed that MALAT1 is up-regulated in IRs and has the effects of inducing oxidative stress and inflammatory responses, promoting vascular endothelial cell proliferation, migration and angiogenesis, and changing epigenetic modifications, which plays an important role in the pathogenesis and regulation of retinal neovascularization.This article summarizes the current research status of MALAT1 in IRs from the aspects of the pathogenesis of IRs, the expression and function of MALAT1 in the retina and its role in angiogenesis, oxidative stress, inflammation, vascular endothelial damage, epigenetic regulation, cell cycle, etc., and explores its role in the occurrence and development of retinal neovascularization to provide a deeper understanding of the mechanism of MALAT1 in the neovascularization of IRs to help develop its targeted treatment strategies.

Objective To explore the medium-and long-term efficacy of modified approach arthroscopy in the treatment of ischial tuberosity cysts in middle-aged and elderly people.Methods Clinical data of 19 cases of ischial tuberosity cyst treated arthroscopically from January 2018 to December 2020 were retrospectively analyzed.The cyst wall was removed by using the central approach of the ischial tuberosity cyst and the 3-5 cm approach of the cyst to the outside of the buttocks.Results The operation time was 30-45 min(mean,36.2±4.8 min).The Visual Analogue Scale(VAS)scores of the pain on the 1st,7th,and 28th d after surgery were 2-6(mean,3.7±1.1),1-4(mean,1.9±0.9),and 0-1(mean,0.5±0.2),respectively.There were 18 cases of incision grade A healing and 1 case of grade B healing.The total hospitalization time was 3-6 d(mean,3.8±1.1 d).There were no complications such as incision infection and subcutaneous hematoma.The 19 cases were followed up for 40-81 months(mean,60.5±10.2 months),and 1 case had cyst recurrence at 3 months after surgery.Conclusion The modified approach arthroscopy is safe and effective in the treatment of ischial tuberosity cysts,having satisfactory medium-and long-term efficacy.

Ischemic retinopathies (IRs) with neovascularization often severely impair vision and even lead to blindness.Studies have shown that long non-coding RNA (lncRNA) MALAT1 is co-expressed with protein-coding genes that regulate retinal cell development.Recent studies have also confirmed that MALAT1 is up-regulated in IRs and has the effects of inducing oxidative stress and inflammatory responses, promoting vascular endothelial cell proliferation, migration and angiogenesis, and changing epigenetic modifications, which plays an important role in the pathogenesis and regulation of retinal neovascularization.This article summarizes the current research status of MALAT1 in IRs from the aspects of the pathogenesis of IRs, the expression and function of MALAT1 in the retina and its role in angiogenesis, oxidative stress, inflammation, vascular endothelial damage, epigenetic regulation, cell cycle, etc., and explores its role in the occurrence and development of retinal neovascularization to provide a deeper understanding of the mechanism of MALAT1 in the neovascularization of IRs to help develop its targeted treatment strategies.

Objective:To explore the mechanism of TLR4/ERK1/2 signaling pathway in progesterone regulating expression of IL-8 in decidual stromal cells(DSCs).Methods:Human DSCs on early pregnancy were isolated and cultured in vitro.The cells were treated with 0.01 μmol/L,0.1 μmol/L and 1 μmol/L progesterone,respectively.Expressions of IL-8,TLR4,ERK1/2 and p-ERK1/2 were detected by Western blot.TLR4 inhibitor TAK-242 and ERK1/2 inhibitor U0126 were further treated,and expression of IL-8 in progesteron+inhibitor group,progesterone group and control group was detected by Western blot.Results:With the increase of pro-gesterone concentration,expression of IL-8 in DSCs decreased gradually.Expressions of DSCs IL-8,TLR4 and p-ERK1/2 in 0.01 μmol/L progesterone group were lower than those in control group(P=0.035 8,P=0.019 4 and P=0.047 1).Expressions of IL-8,TLR4 and p-ERK1/2 in DSCs in 0.1 μmol/L progesterone group were significantly lower than those in control group(P=0.003 5,P=0.004 0 and P=0.009 9).Expressions of IL-8,TLR4 and p-ERK1/2 in DSCs in 1 μmol/L progesterone group were significantly lower than those in control group(P=0.003 3,P=0.001 6 and P=0.005 0).Expression of IL-8 in progesterone+TAK-242 group was signifi-cantly lower than that in progesterone group(P=0.009 1),and expression of IL-8 in progesterone+U0126 group was significantly lower than that in progesterone group(P=0.004).Conclusion:TLR4/ERK1/2 signaling pathway is involved in the physiological process of progesterone regulating expression of IL-8 in DSCs,and progesterone reduces IL-8 expression by inhibiting expression of TLR4 and phosphorylation activation of ERK1/2.

Objective:To investigate the association between blood selenium levels and sex hormones in Chinese men aged 18-79 years.Methods:Data were derived from the China National Human Biomonitoring survey conducted in 2017-2018, with a final sample size of 5 414 men. General demographic characteristics, behavioral habits, and dietary frequency were collected through questionnaires and physical examinations. Fasting blood samples were collected to measure blood lead, serum testosterone, and estradiol levels. Complex sampling linear regression models were used to analyze the associations between blood selenium levels and testosterone, estradiol, and the testosterone/estradiol ratio, adjusting for confounding factors including age, education level, marital status, smoking status, alcohol consumption, seafood intake, soy product intake, protein supplement intake, BMI, and diabetes status.Results:The mean age of the 5 414 participants was (46.85±27.91) years; 4 774 (91.65%) were of Han ethnicity and 4 505 (86.68%) were married. The median ( Q1, Q3) blood selenium concentration in men was 97.80 (80.64, 116.99) μg/L. After adjusting for confounding factors, the complex sampling linear regression model revealed negative associations between blood selenium levels and both testosterone levels and the testosterone/estradiol ratio, with a significant linear trend ( Ptrend<0.05). Compared with the Q1 group, the β (95% CI) values for testosterone in the Q2, Q3, and Q4 groups were -0.02 (-0.06 to 0.02), -0.03 (-0.08 to 0.01), and -0.06 (-0.09 to -0.02), respectively. Similarly, the β (95% CI) values for the testosterone/estradiol ratio in the Q2, Q3, and Q4 groups were -0.01 (-0.03 to 0.02), -0.01 (-0.04 to 0.04), and -0.03 (-0.06 to -0.01), respectively. Subgroup analysis indicated stronger associations between blood selenium levels and testosterone/estradiol levels in non-smoking and obese men (BMI≥28 kg/m2). Conclusion:Blood selenium levels are negatively associated with testosterone levels and the testosterone/estradiol ratio in Chinese adult males.

Objective:To explore the mechanism of TLR4/ERK1/2 signaling pathway in progesterone regulating expression of IL-8 in decidual stromal cells(DSCs).Methods:Human DSCs on early pregnancy were isolated and cultured in vitro.The cells were treated with 0.01 μmol/L,0.1 μmol/L and 1 μmol/L progesterone,respectively.Expressions of IL-8,TLR4,ERK1/2 and p-ERK1/2 were detected by Western blot.TLR4 inhibitor TAK-242 and ERK1/2 inhibitor U0126 were further treated,and expression of IL-8 in progesteron+inhibitor group,progesterone group and control group was detected by Western blot.Results:With the increase of pro-gesterone concentration,expression of IL-8 in DSCs decreased gradually.Expressions of DSCs IL-8,TLR4 and p-ERK1/2 in 0.01 μmol/L progesterone group were lower than those in control group(P=0.035 8,P=0.019 4 and P=0.047 1).Expressions of IL-8,TLR4 and p-ERK1/2 in DSCs in 0.1 μmol/L progesterone group were significantly lower than those in control group(P=0.003 5,P=0.004 0 and P=0.009 9).Expressions of IL-8,TLR4 and p-ERK1/2 in DSCs in 1 μmol/L progesterone group were significantly lower than those in control group(P=0.003 3,P=0.001 6 and P=0.005 0).Expression of IL-8 in progesterone+TAK-242 group was signifi-cantly lower than that in progesterone group(P=0.009 1),and expression of IL-8 in progesterone+U0126 group was significantly lower than that in progesterone group(P=0.004).Conclusion:TLR4/ERK1/2 signaling pathway is involved in the physiological process of progesterone regulating expression of IL-8 in DSCs,and progesterone reduces IL-8 expression by inhibiting expression of TLR4 and phosphorylation activation of ERK1/2.

Objective To explore the medium-and long-term efficacy of modified approach arthroscopy in the treatment of ischial tuberosity cysts in middle-aged and elderly people.Methods Clinical data of 19 cases of ischial tuberosity cyst treated arthroscopically from January 2018 to December 2020 were retrospectively analyzed.The cyst wall was removed by using the central approach of the ischial tuberosity cyst and the 3-5 cm approach of the cyst to the outside of the buttocks.Results The operation time was 30-45 min(mean,36.2±4.8 min).The Visual Analogue Scale(VAS)scores of the pain on the 1st,7th,and 28th d after surgery were 2-6(mean,3.7±1.1),1-4(mean,1.9±0.9),and 0-1(mean,0.5±0.2),respectively.There were 18 cases of incision grade A healing and 1 case of grade B healing.The total hospitalization time was 3-6 d(mean,3.8±1.1 d).There were no complications such as incision infection and subcutaneous hematoma.The 19 cases were followed up for 40-81 months(mean,60.5±10.2 months),and 1 case had cyst recurrence at 3 months after surgery.Conclusion The modified approach arthroscopy is safe and effective in the treatment of ischial tuberosity cysts,having satisfactory medium-and long-term efficacy.