Osteoarthritis (OA), a highly prevalent degenerative joint disease worldwide, is defined by articular cartilage degradation, abnormal bone remodeling, and persistent chronic inflammation. It severely compromises patients’ quality of life, and currently, there is no radical cure. Abnormal mechanical stress is widely regarded as a core driver of OA pathogenesis, and the exploration of mechanical signal perception and transduction mechanisms has become crucial for deciphering OA’s pathophysiological processes. Piezo1, a key mechanosensitive cation channel belonging to the Piezo protein family, has recently gained significant attention due to its pivotal role in mediating cellular responses to mechanical stimuli in joint tissues. This review systematically examines Piezo1’s expression patterns, regulatory mechanisms, and pathological functions in OA, with a particular focus on its dual roles in modulating chondrocyte homeostasis and bone metabolism disorders, while also delving into the underlying molecular signaling pathways and potential therapeutic implications. Piezo1, consisting of approximately 2 500 amino acids and forming a unique trimeric propeller-like structure, is widely expressed in chondrocytes, osteocytes, mesenchymal stem cells, and synovial cells. It exhibits permeability to cations such as Ca²⁺, K⁺, and Na⁺, and directly responds to membrane tension changes induced by mechanical stimuli like fluid shear stress and mechanical overload. In OA patients and animal models, Piezo1 expression is significantly upregulated, especially in cartilage regions subjected to abnormal mechanical stress (e.g., human temporomandibular joint cartilage). This overexpression is closely associated with aggravated cartilage degeneration, increased chondrocyte apoptosis, accelerated cellular senescence, and intensified inflammatory responses. Mechanical overload and pro-inflammatory cytokines (e.g., IL-1β) are key inducers of Piezo1 upregulation: IL-1β activates the PI3K/AKT/mTOR signaling pathway to enhance Piezo1 expression, forming a pathogenic positive feedback loop that inhibits chondrocyte autophagy, promotes apoptosis, and further accelerates joint degeneration. Mechanistically, Piezo1 mediates OA progression through multiple interconnected pathways. When activated by mechanical stress, Piezo1 triggers excessive Ca²⁺ influx, leading to endoplasmic reticulum stress (ERS) and mitochondrial dysfunction, which directly induce chondrocyte apoptosis. This process involves the activation of downstream signaling cascades such as cGAS-STING and YAP-MMP13/ADAMTS5. YAP, a transcriptional regulator, upregulates the expression of matrix metalloproteinase 13 (MMP13) and aggrecanase (ADAMTS5), thereby accelerating cartilage matrix degradation. Additionally, Piezo1-driven Ca²⁺ overload promotes the accumulation of reactive oxygen species (ROS) and upregulates senescence markers (p16 and p21), accelerating chondrocyte senescence via the p38MAPK and NF-κB pathways. Senescent chondrocytes secrete senescence-associated secretory phenotype (SASP) factors (e.g., IL-6, IL-1β), further amplifying joint inflammation. In terms of bone metabolism, Piezo1 maintains joint homeostasis by promoting the differentiation of fibrocartilage stem cells into chondrocytes and balancing bone formation and resorption through regulating the FoxC1/YAP axis and RANKL/OPG ratio. Therapeutically, targeting Piezo1 shows promising potential. Preclinical studies have demonstrated that Piezo1 inhibitors (e.g., GsMTx4) can reduce joint damage and alleviate pain in OA mice. Simultaneously, siRNA-mediated co-silencing of Piezo1 and TRPV4 (another mechanosensitive channel) decreases intracellular Ca²⁺ concentration, inhibits chondrocyte apoptosis, and promotes cartilage repair. Conditional knockout of Piezo1 using Gdf5-Cre transgenic mice alleviates cartilage degeneration in post-traumatic OA models by downregulating MMP13 and ADAMTS5 expression. Despite existing challenges, such as off-target effects of inhibitors, inefficient local drug delivery, and interindividual genetic variability, strategies like developing selective Piezo1 antagonists, optimizing targeted nanocarriers, and combining Piezo1-targeted therapy with physical therapy provide viable avenues for clinical translation. The authors propose that Piezo1 serves as a critical therapeutic target for OA, and future research should focus on deciphering its context-dependent regulatory networks, developing tissue-specific intervention strategies, and validating their efficacy and safety in clinical trials to address the unmet medical needs of OA patients.

Iron,a vital trace element and redox-active metal in the human body,is pivotal in cellular processes and en-gages in a multitude of biological reactions.Ferroptosis,an emerging form of regulated cell death,is predominantly instiga-ted by the excessive free iron that catalyzes reactive oxygen species(ROS)production via the Fenton reaction.This process results in the peroxidation of polyunsaturated fatty acids within the cellular lipid membrane,compromising the membrane's integrity and thereby inducing ferroptosis.In the context of diabetic retinopathy(DR),ferroptosis plays a sig-nificant role.The disruption of iron metabolism,the excessive accumulation of ROS,and the imbalance of the antioxidant system are key mechanisms contributing to ferroptosis in retinal tissues and the exacerbation of DR's pathological progres-sion.This review provides a systematic summary and in-depth discussion of the advancements in understanding the role of ferroptosis in DR pathogenesis,intending to offer valuable insights for future research endeavors in this field.

Objective To understand the molecular epidemiological characteristics and hypervirulence evolution trend of ST11 carbapenem-resistant Klebsiella pneumoniae(CRKP)isolated from medical institutions in Shanghai,and provide scientific basis for formulating the prevention and control measures of drug-resistant organisms.Methods A total of 201 strains of CRKP isolated from 12 medical institutions in Shanghai from 2021 to 2022 were collected.Antimicrobial susceptibility testing and whole genome sequencing were performed.The concatenated data was used for multilocus sequencing typing(MLST),serum typing(wzi typing),as well as analysis of resistance and viru-lence genes.Results All 201 CRKP strains were multidrug-resistant organisms(MDROs).These strains were al-most completely resistant to carbapenems,cephalosporins,and quinolones.Drug resistance gene analysis showed that 93.03％of CRKP strains carried KPC gene.201 CRKP strains were divided into 6 ST types and 10 capsule wzi types,with ST11-KL64(n=104)being the dominant type,followed by ST15-KL19(n=54).52.24％(n=105)of CRKP carried rpmA/rpmA2+iucA+iutA+iroN genes.Conclusion CRKP isolated from medical institutions in Shanghai is mainly ST11-KL64 type with severe multidrug resistance,and more than half of the strains are hyper-virulent carbapenem-resistant Klebsiella pneumoniae(hv-CRKP).It is necessary to continuously strengthen the monitoring of the molecular characteristics of CRKP,so as to prevent outbreaks of healthcare-associated infection.

Iron,a vital trace element and redox-active metal in the human body,is pivotal in cellular processes and en-gages in a multitude of biological reactions.Ferroptosis,an emerging form of regulated cell death,is predominantly instiga-ted by the excessive free iron that catalyzes reactive oxygen species(ROS)production via the Fenton reaction.This process results in the peroxidation of polyunsaturated fatty acids within the cellular lipid membrane,compromising the membrane's integrity and thereby inducing ferroptosis.In the context of diabetic retinopathy(DR),ferroptosis plays a sig-nificant role.The disruption of iron metabolism,the excessive accumulation of ROS,and the imbalance of the antioxidant system are key mechanisms contributing to ferroptosis in retinal tissues and the exacerbation of DR's pathological progres-sion.This review provides a systematic summary and in-depth discussion of the advancements in understanding the role of ferroptosis in DR pathogenesis,intending to offer valuable insights for future research endeavors in this field.

BACKGROUND:Currently,different methods of model establishment have been derived from different injury modes of spinal cord injury.Traditional physical injury modeling methods have their own advantages and disadvantages,and there is a lack of more effective and stable animal models of spinal cord injury. OBJECTIVE:To establish a reproducible,controllable,trauma-free,low-mortality,more stable,widely applicable,and short-term postoperative care rat model of spinal cord injury. METHODS:Forty Sprague-Dawley rats with similar body mass and ages were randomly divided into a control group and an improved group,with 20 rats in each group.Animal models of spinal cord injury in the control group were constructed using a clip model method,while the improved group used a modified ligation method based on the compression method to make the spinal cord injury models using suture ligation based on fenestration.Postoperative comparisons were made between the two groups,assessing urination behavior,hematuria,pyuria(infection rate),mortality,scoliosis rate and Basso-Beattie-Bresnahan locomotor rating scale scores at 1,3,5,and 7 days after modeling. RESULTS AND CONCLUSION:Compared with the conventional modeling method,the modified ligation method based on the compression method resulted in faster recovery of urination behavior,lower hematuria rate,lower infection rate,lower mortality rate,lower scoliosis rate,and more concentrated and stable Basso-Beattie-Bresnahan scores(all below 2 points within 1 week).This proves that the modified ligation method based on compression is more suitable for the establishment of spinal cord injury models in rats.

Objective:To establish and assess the quality control and improvement system for metabolic and bariatric surgery in Beijing.Methods:Based on relevant documents from the National Health Commission and the Beijing Municipal Health Commission,and referencing the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) by the American Society for Metabolic and Bariatric Surgery,a quality control system was developed under the Beijing Quality Control and Improvement Center of Metabolic and Bariatric Surgery. The system incorporated on-site evaluations,data registration,and specialized training. From May to December 2023,on-site assessments were conducted at 21 hospitals in Beijing performing bariatric surgery,evaluating personnel qualifications,infrastructure,clinical workflows,and postoperative follow-up. A quality control database was created to collect real-time surgical data,and training was provided for data entry and professional skills. Assessment results were classified as excellent,qualified,or needing improvement,with rectification suggestions offered and follow-up visits conducted to track progress.Results:All 21 hospitals achieved a 100% compliance rate for surgical indications, 16 (76.2%) met standardized surgical operation criteria,and 14 (66.7%) had standardized postoperative management. However,only 5 (23.8%) achieved a 12-month postoperative follow-up rate of ≥60%,and 4 (19.1%) had established specialized databases. Key challenges included insufficient specialized staffing (19.1%), lack of multidisciplinary collaboration (47.6%), inadequate equipment (57.1%), and low follow-up rates (57.1%). The database collected data from over 2 000 patients across 111 fields. After rectification, specialized database coverage rose to 61.9% (13 hospitals). Multi-level training programs developed backbone physicians and specialized nurses,significantly addressing the shortage of specialized personnel.Conclusion:The quality control system established in this study,through the integration of on-site evaluation,data registration,and specialized training,effectively enhances the standardization of surgical practices and data management capabilities.

Objective To understand the molecular epidemiological characteristics and hypervirulence evolution trend of ST11 carbapenem-resistant Klebsiella pneumoniae(CRKP)isolated from medical institutions in Shanghai,and provide scientific basis for formulating the prevention and control measures of drug-resistant organisms.Methods A total of 201 strains of CRKP isolated from 12 medical institutions in Shanghai from 2021 to 2022 were collected.Antimicrobial susceptibility testing and whole genome sequencing were performed.The concatenated data was used for multilocus sequencing typing(MLST),serum typing(wzi typing),as well as analysis of resistance and viru-lence genes.Results All 201 CRKP strains were multidrug-resistant organisms(MDROs).These strains were al-most completely resistant to carbapenems,cephalosporins,and quinolones.Drug resistance gene analysis showed that 93.03％of CRKP strains carried KPC gene.201 CRKP strains were divided into 6 ST types and 10 capsule wzi types,with ST11-KL64(n=104)being the dominant type,followed by ST15-KL19(n=54).52.24％(n=105)of CRKP carried rpmA/rpmA2+iucA+iutA+iroN genes.Conclusion CRKP isolated from medical institutions in Shanghai is mainly ST11-KL64 type with severe multidrug resistance,and more than half of the strains are hyper-virulent carbapenem-resistant Klebsiella pneumoniae(hv-CRKP).It is necessary to continuously strengthen the monitoring of the molecular characteristics of CRKP,so as to prevent outbreaks of healthcare-associated infection.

Objective:To establish and assess the quality control and improvement system for metabolic and bariatric surgery in Beijing.Methods:Based on relevant documents from the National Health Commission and the Beijing Municipal Health Commission,and referencing the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) by the American Society for Metabolic and Bariatric Surgery,a quality control system was developed under the Beijing Quality Control and Improvement Center of Metabolic and Bariatric Surgery. The system incorporated on-site evaluations,data registration,and specialized training. From May to December 2023,on-site assessments were conducted at 21 hospitals in Beijing performing bariatric surgery,evaluating personnel qualifications,infrastructure,clinical workflows,and postoperative follow-up. A quality control database was created to collect real-time surgical data,and training was provided for data entry and professional skills. Assessment results were classified as excellent,qualified,or needing improvement,with rectification suggestions offered and follow-up visits conducted to track progress.Results:All 21 hospitals achieved a 100% compliance rate for surgical indications, 16 (76.2%) met standardized surgical operation criteria,and 14 (66.7%) had standardized postoperative management. However,only 5 (23.8%) achieved a 12-month postoperative follow-up rate of ≥60%,and 4 (19.1%) had established specialized databases. Key challenges included insufficient specialized staffing (19.1%), lack of multidisciplinary collaboration (47.6%), inadequate equipment (57.1%), and low follow-up rates (57.1%). The database collected data from over 2 000 patients across 111 fields. After rectification, specialized database coverage rose to 61.9% (13 hospitals). Multi-level training programs developed backbone physicians and specialized nurses,significantly addressing the shortage of specialized personnel.Conclusion:The quality control system established in this study,through the integration of on-site evaluation,data registration,and specialized training,effectively enhances the standardization of surgical practices and data management capabilities.

Objective To investigate the effect of neural precursor cell expressed,developmentally down-regulated 4-1(NEDD4-1)on the biological activity and epithelial-mesenchymal transition(EMT)of human pancreatic cancer cells and the underlying mecha-nism.Methods The expression level of NEDD4-1 in the BxPC-3 cell line was down-regulated by siRNA interference technology.The experiment was divided into the control group,si-NC group,and NEDD4-1 silencing group(si-NEDD4-1 group).Real-time fluorescence quantitative polymerase chain reaction(RT-qPCR)method was used to detect the expression changes of NEDD4-1 and EMT-related markers mRNA in each group.The cell proliferation activity was evaluated by MTT assay,the apoptosis rate was detected by flow cytometry,the activity of migration and invasion was analyzed by scratch and transwell experiments,and the expression of NEDD4-1,EMT-related proteins,and JAK2/STAT3 pathway proteins were detected by Western blot.Results Compared with the control group and si-NC group,the mRNA and protein expressions of NEDD4-1,N-cadherin,and Vimentin in si-NEDD4-1 group were significantly decreased(P＜0.05),while the mRNA and protein expressions of E-cadherin were up-regulated(P＜0.05).The proliferation,migration,and invasion of cells in the si-NEDD4-1 group were inhibited(P＜0.05),while the apoptosis activity was sig-nificantly increased(P＜0.05).The expression levels of p-JAK and p-STAT3 protein in the si-NEDD4-1 group were decreased(P＜0.05).There was no significant difference in the above indicators between the control group and the si-NC group.Conclusion NEDD4-1 may promote the EMT process of pancreatic cancer cells through the JAK2/STAT3 pathway,and then regulate the prolifera-tion,apoptosis,migration,and invasion activities of pancreatic cancer cells.

Objective To investigate the effect of neural precursor cell expressed,developmentally down-regulated 4-1(NEDD4-1)on the biological activity and epithelial-mesenchymal transition(EMT)of human pancreatic cancer cells and the underlying mecha-nism.Methods The expression level of NEDD4-1 in the BxPC-3 cell line was down-regulated by siRNA interference technology.The experiment was divided into the control group,si-NC group,and NEDD4-1 silencing group(si-NEDD4-1 group).Real-time fluorescence quantitative polymerase chain reaction(RT-qPCR)method was used to detect the expression changes of NEDD4-1 and EMT-related markers mRNA in each group.The cell proliferation activity was evaluated by MTT assay,the apoptosis rate was detected by flow cytometry,the activity of migration and invasion was analyzed by scratch and transwell experiments,and the expression of NEDD4-1,EMT-related proteins,and JAK2/STAT3 pathway proteins were detected by Western blot.Results Compared with the control group and si-NC group,the mRNA and protein expressions of NEDD4-1,N-cadherin,and Vimentin in si-NEDD4-1 group were significantly decreased(P＜0.05),while the mRNA and protein expressions of E-cadherin were up-regulated(P＜0.05).The proliferation,migration,and invasion of cells in the si-NEDD4-1 group were inhibited(P＜0.05),while the apoptosis activity was sig-nificantly increased(P＜0.05).The expression levels of p-JAK and p-STAT3 protein in the si-NEDD4-1 group were decreased(P＜0.05).There was no significant difference in the above indicators between the control group and the si-NC group.Conclusion NEDD4-1 may promote the EMT process of pancreatic cancer cells through the JAK2/STAT3 pathway,and then regulate the prolifera-tion,apoptosis,migration,and invasion activities of pancreatic cancer cells.