The development of bone in human body and the maintenance of bone mass in adulthood are regulated by a variety of biological factors. Myocyte enhancer factor 2C (MEF2C), as one of the many factors regulating bone tissue development and balance, has been shown to play a key role in bone development and metabolism. However, there is limited systematic analysis on the effects of MEF2C on bone tissue. This article reviews the role of MEF2C in bone development and metabolism. During bone development, MEF2C promotes the development of neural crest cells (NC) into craniofacial cartilage and directly promotes cartilage hypertrophy. In terms of bone metabolism, MEF2C exhibits a differentiated regulatory model across different types of osteocytes, demonstrating both promoting and other potential regulatory effects on bone formation, with its stimulating effect on osteoclasts being determined. In view of the complex roles of MEF2C in bone tissue, this paper also discusses its effects on some bone diseases, providing valuable insights for the physiological study of bone tissue and strategies for the prevention of bone diseases.
Humans ; MEF2 Transcription Factors/physiology* ; Bone and Bones/metabolism* ; Animals ; Bone Development/physiology* ; Osteogenesis/physiology* ; Myogenic Regulatory Factors/physiology*

OBJECTIVES: To evaluate preterm white matter injury (PWMI) in neonatal rats using multimodal magnetic resonance imaging (MRI) combined with histological assessments and to explore its underlying mechanisms. METHODS: Healthy 3-day-old Sprague-Dawley neonatal rats were randomly divided into a sham operation group and a PWMI group (n=12 in each group). A PWMI model was established in neonatal rats through hypoxia-ischemia. Laser speckle imaging was used to observe changes in cerebral oxygen saturation and blood flow at different time points post-modeling. Multimodal MRI was employed to assess the condition of white matter injury, while hematoxylin-eosin staining was utilized to observe morphological changes in the striatal area on the injured side. Immunofluorescence staining was performed to detect the proliferation and differentiation of oligodendrocyte precursor cells. RESULTS: At 0, 6, 12, 24, and 72 hours post-modeling, the relative blood flow and relative oxygen saturation on the injured side in the PWMI group were significantly lower than those in the sham operation group (P<0.05). At 24 hours post-modeling, T2-weighted imaging showed high signals in the white matter of the injured side in the PWMI group, with relative apparent diffusion coefficient values and Lorenz differential values being lower than those in the sham operation group (P<0.001); additionally, the arrangement of nerve cells in the PWMI group was disordered, and the number of EdU⁺PDGFR-α⁺ cells was higher than that in the sham operation group (P<0.001). At 28 days post-modeling, the relative fractional anisotropy values, the number of EdU⁺Olig2⁺ cells, and the fluorescence intensity of myelin basic protein and neurofilament protein 200 in the white matter region of the PWMI group were all lower than those in the sham operation group (P<0.001). CONCLUSIONS Multimodal MRI can evaluate early and long-term changes in PWMI in neonatal rat models in vivo, providing both imaging and pathological evidence for the diagnosis and treatment of PWMI in neonates. Hypoxia-ischemia inhibits the proliferation and differentiation of oligodendrocyte precursor cells in neonatal rats, leading to PWMI.
Animals ; Rats, Sprague-Dawley ; Magnetic Resonance Imaging/methods* ; Rats ; White Matter/injuries* ; Animals, Newborn ; Female ; Multimodal Imaging ; Male ; Hypoxia-Ischemia, Brain/pathology*

Cyclin-dependent kinases (CDKs) are proline-induced serine/threonine kinases that are primarily involved in the regulation of cell cycle, gene transcription, and cell differentiation. In general, CDKs are activated by binding to specific regulatory subunits of cell cycle proteins and are regulated by phosphorylation of specific T-loops by CDK activated kinases. In the CDKs family, cyclin-dependent kinase 5 (CDK5) is a specialized member whose activity is triggered only by interaction with p35 and p39, which do not have the same sequence as the cell cycle proteins, and this may be one reason why CDK5 is distinguished from other CDK members by its structural and functional differences. In addition, unlike most CDK members that require phosphorylation at specific sites to function, CDK5 does not require such phosphorylation, and it can be activated simply by binding to p35 and p39. More notably, inhibitors that are commonly used to inhibit the activity of other CDK members have almost zero effect on CDK5. In contrast, CDK5, as a unique CDK family member, plays an important role in the development of numerous diseases. In metabolic diseases, elevated CDK5 expression leads to decreased insulin secretion, increased foam cell formation and triggers decreased bone mass in the body, thus accelerating metabolic diseases, and the role of CDK5 in bone biology is gradually gaining attention, and the role of CDK5 in bone metabolic diseases may become a hotspot for research in the future; in neurodegenerative diseases, hyperphosphorylation of Tau protein is an important hallmark of Alzheimer’s disease development, and changes in CDK5 expression are associated with Tau protein phosphorylation and nerve death, indicating that CDK5 is highly related to the development of the nervous system; in tumor diseases, the role of CDK5 in the proliferation, differentiation and migration and invasion of tumor cells marks the development of tumorigenesis, but different researchers hold different views, and further studies are needed in the follow-up. Therefore, the study of its mechanism of action in diseases can help to reveal the pathogenesis and pathological process of diseases. Appropriate exercise not only helps in the prevention of diseases, but also plays a positive role in the treatment of diseases. Exercise-induced mechanical stress can improve bone microstructure and increase bone mass in osteoporosis patients. In addition, exercise can effectively inhibit neuronal apoptosis and improve mitochondrial dysfunction, more importantly, appropriate exercise can inhibit the proliferation of cancer cells to a certain extent. It can be seen that exercise occupies a pivotal position in the prevention and treatment of pathologic diseases. It has been shown that exercise can reduce the expression of CDK5 and affect the pathological process of neurological diseases. Currently, there is a dearth of research on the specific mechanisms of CDK5’s role in improving disease outcomes through exercise. In order to understand its effects more comprehensively, subsequent studies need to employ diverse exercise modalities, targeting patients with various types of diseases or corresponding animal models for in-depth exploration. This article focuses on the pathological functions of CDK5 and its relationship with exercise, with a view to providing new insights into the prevention and treatment of disease by CDK5.

Osteosarcopenia (OS) is a multifactorial, multiaetiologic degenerative metabolic syndrome in which sarcopenia coexists with osteoporosis, and its influences are related to aging-induced mechanics, genetics, inflammatory factors, endocrine disorders, and irregular lifestyles. With the accelerated aging process in our country, osteosarcopenia has become a public health problem that cannot be ignored, with a higher risk of falls, fractures, impaired mobility and death. In recent years, scholars at home and abroad have conducted a lot of research on osteosarcopenia, but their pathogenesis is still unclear. Understanding the signaling pathways associated with osteosarcopenia is of great significance for further research on the pathogenesis of these disorders and for finding new targets for treatment. Studies have shown that activation of the PI3K/Akt signaling pathway promotes osteoblast differentiation as well as skeletal muscle regeneration, indicating that inhibition of thePI3K/Akt signaling pathway is closely related to the development of osteosarcopenia. Muscle factor-mechanical stress interactions can maintain osteoblast viability by activating the Wnt/β-catenin signaling pathway, suggesting that Wnt signaling is important in muscle and bone crosstalk. The Notch signaling pathway also plays an important role in improving bone and muscle mass and function, but different researchers hold different views, which need to be further validated and refined in subsequent studies. Exercise, as an existing non-pharmacological treatment with strong and sustained effects on physical function and muscle strength, also significantly increases bone density in osteoporosis patients, which may be mainly due to the fact that exercise induces changes in the form and function of bones, in the form of muscular pulling and indirectly improves the bone mass, and changes in the bone strength can also change the number, shape as well as the function of the muscles. At the same time, the mechanism of different exercise modalities focuses on different aspects, and there are differences in exercise time, exercise intensity, and therapeutic effects in the implementation of interventions. Aerobic exercise can improve the quality of skeletal muscle and increase the expression of osteogenesis-related genes by stimulating mitochondrial biosynthesis, as well as improve the quality and strength of bones and muscles through the Wnt/β- catenin and PI3K/Akt signaling pathways, effectively preventing and controlling the occurrence of musculoskeletal disorders. High-intensity resistance exercise has a significant effect on improving the quality of muscles and bone mineral density, but older people with osteosarcopenia suffer from a decline in muscle quality and strength, and a decline in bone mineral density, which makes them very susceptible to fracture, so they should select the intensity of the training in a gradual and orderly manner, from small to large. What kind of exercise intensity and exercise modalities are most effective in improving the occurrence and development of osteosarcopenia needs to be further investigated. Therefore, this paper mainly reviews the epidemiology of osteosarcopenia, diagnostic criteria, the related signaling pathways (PI3K/Akt pathway, Wnt/β-catenin pathway, Notch pathway, NF-κB pathway) that jointly regulate the metabolic process of myocytes and skeletal cells, as well as the interventional effects of different exercise modes on osteosarcopenia, with the aim of providing theoretical bases for the clinical treatment of osteosarcopenia, as well as enhancing the preventive capacity of the disease in old age.

Osteoporosis leads to an imbalance in bone remodelling, where bone resorption is greater than bone formation and osteoclast degradation increases, resulting in severe bone loss. Autophagy is a lysosomal degradation pathway that regulates the proliferation, differentiation, and apoptosis of various bone cells (including osteoblasts, osteoclasts, and osteoclasts), and is deeply involved in the bone remodelling process. In recent years, the role of autophagy in the progression of osteoporosis and related bone metabolic diseases has received more and more attention, and it has become a research hotspot in this field. Summarising the existing studies, it is found that senile osteoporosis is the result of a combination of factors. On the one hand, it is the imbalance of bone remodelling and the increase of bone resorption/bone formation ratio with ageing, which causes progressive bone loss. On the other hand, aging leads to a general decrease in the level of autophagy, a decrease in the activity of osteoblasts and osteoclasts, and an inhibition of osteogenic differentiation. The lack of oestrogen leads to the immune system being in a low activation state, and the antioxidant capacity is weakened and inflammatory response is increased, inducing autophagy-related proteins to participate in the transmission of inflammatory signals, excessive accumulation of reactive oxygen species (ROS) in the skeleton, and negatively regulating bone formation. In addition, with aging and the occurrence of related diseases, glucocorticoid treatments also mediate autophagy in bone tissue cells, contributing to the decline in bone strength. Exercise, as an effective means of combating osteoporosis, improves bone biomechanical properties and increases bone density. It has been found that exercise induces oxidative stress, energy imbalance, protein defolding and increased intracellular calcium ions in the organism, which in turn activates autophagy. In bone, exercise of different intensities activates messengers such as ROS, PI3K, and AMP. These messengers signal downstream cascades, which in turn induce autophagy to restore dynamic homeostasis in vivo. During exercise, increased production of AMP, PI3K, and ROS activate their downstream effectors, AMPK, Akt, and p38MAPK, respectively, and these molecules in turn lead to activation of the autophagy pathway. Activation of AMPK inhibits mTOR activity and phosphorylates ULK1 at different sites, inducing autophagy. AMPK and p38 up-regulate per-PGC-1α activity and activate transcription factors in the nucleus, resulting in increased autophagy and lysosomal genes. Together, they activate FoxOs, whose transcriptional activity controls cellular processes including autophagy and can act on autophagy key proteins, while FoxOs proteins are expressed in osteoblasts. Exercise also regulates the expression of mTORC1, FoxO1, and PGC-1 through the PI3K/Akt signalling pathway, which ultimately plays a role in the differentiation and proliferation of osteoblasts and regulates bone metabolism. In addition, BMPs signaling pathway and long chain non-coding RNAs also play a role in the proliferation and differentiation of osteoblasts and autophagy process under exercise stimulation. Therefore, exercise may become a new molecular regulatory mechanism to improve osteoporosis through the bone autophagy pathway, but the specific mechanism needs to be further investigated. How exercise affects bone autophagy and thus prevents and treats bone-related diseases will become a future research hotspot in the fields of biology, sports medicine and sports science, and it is believed that future studies will further reveal its mechanism and provide new theoretical basis and ideas.

Objective To observe the effects of abdominal penetrating moxibustion combined with acupuncture at the"four chong points"on balance,walking function and trunk control in patients recovering from stroke.Methods Seventy-eight patients recovering from stroke were randomly divided into an observation group and a control group,with 39 patients in each group.The control group was given conventional rehabilitation exercises,while the observation group was given abdominal penetrating moxibustion combined with acupuncture at the"four chong points"on the basis of the control group.Both groups were treated for 2 consecutive months.After 2 months of treatment,the clinical efficacy of the two groups was evaluated,and the changes in the Berg Scale score and the Timed Up and Go Test(TUGT)were observed before and after treatment.The changes in the National Institutes of Health Stroke Scale(NIHSS)scores were compared before and after treatment between the two groups.The Sheikh Trunk Control Scale scores were also evaluated.Results(1)The total effective rate of the observation group was 94.87%(37/39),and the total effective rate of the control group was 80.00%(31/39),and the efficacy of the observation group was superior to that of the control group,and the difference was statistically significant(P＜0.05).(2)After treatment,the Berg scores of the patients in the two groups were significantly increased(P＜0.05),and the Berg scores of the observation group were higher than those of the control group,and the difference was statistically significant(P＜0.05).(3)After treatment,the TUGT time and NIHSS score of patients in the two groups were significantly improved(P＜0.05),and the TUGT time of the observation group was shorter than that of the control group,and the NIHSS score was lower than that of the control group,and the difference was statistically significant(P＜0.05).(4)After treatment,the Sheikh trunk control scores of the two groups were significantly increased(P＜0.05),and the Sheikh trunk control score of the observation group was higher than that of the control group,and the difference was statistically significant(P＜0.05).Conclusion Abdominal penetrating moxibustion method combined with acupuncture at the four chong points for the treatment of stroke recovery can effectively restore the patients'balance and walking function,improve the patients'trunk control ability,and the therapeutic effect is precise.

Officers and soldiers exposed to high temperature and high-humidity environments are highly susceptible to exertional heat illness and even heatstroke.Reports indicated that after conventional treatment,the heat endurance damage in officers/soldiers with exertional heat illness can persist for months or even years.Therefore,the Expert Group of Heatstroke Prevention and Treatment of Heatstroke of Chinese PLA has specially formulated a technical proposal for the reconstruction of heat endurance in officers/soldiers suffering from exertional heatstroke,aiming to provide a safeguard for reconstruction of heat endurance in affected personnel.This article mainly elaborates on the basic concepts,technical requirements,initiation timing,implementation assessment,and follow-up of the heat endurance reconstruction for officers/soldiers with exertional heatstroke.

Objective To observe the effects of melatonin on autophagy in cortical neurons of neonatal rats with hypoxic-ischemic brain damage(HIBD)and to explore its mechanisms via the PI3K/AKT signaling pathway,aiming to provide a basis for the clinical application of melatonin.Methods Seven-day-old Sprague-Dawley neonatal rats were randomly divided into a sham operation group,an HIBD group,and a melatonin group(n=9 each).The neonatal rat HIBD model was established using the classic Rice-Vannucci method.Neuronal morphology in the neonatal rat cerebral cortex was observed with hematoxylin-eosin staining and Nissl staining.Autophagy-related protein levels of microtubule-associated protein 1 light chain 3(LC3)and Beclin-1 were detected by immunofluorescence staining and Western blot analysis.Phosphorylated phosphoinositide 3-kinase(p-PI3K)and phosphorylated protein kinase B(p-AKT)protein expression levels were measured by immunohistochemistry and Western blot.The correlation between autophagy and the PI3K pathway in the melatonin group and the HIBD group was analyzed using Pearson correlation analysis.Results Twenty-four hours post-modeling,neurons in the sham operation group displayed normal size and orderly arrangement.In contrast,neurons in the HIBD group showed swelling and disorderly arrangement,while those in the melatonin group had relatively normal morphology and more orderly arrangement.Nissl bodies were normal in the sham operation group but distorted in the HIBD group;however,they remained relatively intact in the melatonin group.The average fluorescence intensity of LC3 and Beclin-1 was higher in the HIBD group compared to the sham operation group,but was reduced in the melatonin group compared to the HIBD group(P<0.05).The number of p-PI3K+and p-AKT+cells decreased in the HIBD group compared to the sham operation group but increased in the melatonin group compared to the HIBD group(P<0.05).LC3 and Beclin-1 protein expression levels were higher,and p-PI3K and p-AKT levels were lower in the HIBD group compared to the sham operation group(P<0.05);however,in the melatonin group,LC3 and Beclin-1 levels decreased,and p-PI3K and p-AKT increased compared to the HIBD group(P<0.05).The correlation analysis results showed that the difference of the mean fluorescence intensity of LC3 and Beclin-1 protein in the injured cerebral cortex between the melatonin and HIBD groups was negatively correlated with the difference of the number of p-PI3K+and p-AKT+cells between the two groups(P<0.05).Conclusions Melatonin can inhibit excessive autophagy in cortical neurons of neonatal rats with HIBD,thereby alleviating HIBD.This mechanism is associated with the PI3K/AKT pathway.

Traumatic supraorbital fissure syndrome (TSOFS) is a symptom complex caused by nerve entrapment in the supraorbital fissure after skull base trauma. If the compressed cranial nerve in the supraorbital fissure is not decompressed surgically, ptosis, diplopia and eye movement disorder may exist for a long time and seriously affect the patients′ quality of life. Since its overall incidence is not high, it is not familiarized with the majority of neurosurgeons and some TSOFS may be complicated with skull base vascular injury. If the supraorbital fissure surgery is performed without treatment of vascular injury, it may cause massive hemorrhage, and disability and even life-threatening in severe cases. At present, there is no consensus or guideline on the diagnosis and treatment of TSOFS that can be referred to both domestically and internationally. To improve the understanding of TSOFS among clinical physicians and establish standardized diagnosis and treatment plans, the Skull Base Trauma Group of the Neurorepair Professional Committee of the Chinese Medical Doctor Association, Neurotrauma Group of the Neurosurgery Branch of the Chinese Medical Association, Neurotrauma Group of the Traumatology Branch of the Chinese Medical Association, and Editorial Committee of Chinese Journal of Trauma organized relevant experts to formulate Chinese expert consensus on the diagnosis and treatment of traumatic supraorbital fissure syndrome ( version 2024) based on evidence of evidence-based medicine and clinical experience of diagnosis and treatment. This consensus puts forward 12 recommendations on the diagnosis, classification, treatment, efficacy evaluation and follow-up of TSOFS, aiming to provide references for neurosurgeons from hospitals of all levels to standardize the diagnosis and treatment of TSOFS.

Cytochrome P450 reductase (CPR) is essential for the electron transport chain of cytochrome P450s, playing an indispensable role in electron transfer in vivo. In this study, one cDNA encoding cytochrome P450 reductase (Ascpr1) was identified from the callus of Aquilaria sinensis. Ascpr1 contains an open reading frame of 2 124 bp. The deduced protein is composed of 707 amino acids, with a predicted molecular weight of 78.82 kD. Phylogenetic analysis revealed that AsCPR1 is a type Ⅱ CPR protein closely related to the CPR from Theobroma cacao. Transmembrane prediction using TMHMM 2.0 indicated that the amino acids 52-71 of AsCPR1 comprise a transmembrane region. After truncating of 67 amino acid residues from N-terminal, the truncated AsCPR1 was successfully expressed in E. coli Transetta (DE3). Further purification of the recombinant AsCPR1 by affinity chromatography and determination of the enzymatic activity allowed the reducing ability of AsCPR1 to cytochrome C in vitro. The results pave the way for further study on the synthesis of defensive chemicals involved in P450s and the functions of CPR in self-defense of A. sinensis.