Spermatogenesis is a highly ordered and spatiotemporally regulated developmental process in the male reproductive system, during which spermatogonial stem cells (SSCs), supported by the seminiferous tubule microenvironment, sequentially undergo mitosis, meiosis, and spermiogenesis to ultimately generate structurally intact spermatozoa. This complex process is accompanied by extensive transcriptional reprogramming, chromatin remodeling, and finely tuned post-transcriptional regulation. Precise control of RNA fate is therefore essential for maintaining the continuity and fidelity of spermatogenesis, and its disruption represents a major molecular basis of male infertility. N⁶-methyladenosine (m⁶A), the most abundant internal RNA modification in eukaryotes, has emerged as a critical regulator of post-transcriptional gene expression. m⁶A methyltransferases (“writers”) catalyze the addition of a methyl group to the N⁶ position of adenosine, m⁶A demethylases (“erasers”) remove the modification, and m⁶A-binding proteins (“readers”) recognize m⁶A-modified transcripts. Through the coordinated actions of these factors, m⁶A regulates transcript fate at multiple levels, including RNA splicing, nuclear export, stability, translation, and decay. Emerging evidence indicates that m⁶A-mediated regulation is essential across multiple stages of spermatogenesis, including SSC self-renewal and differentiation, meiotic progression, maintenance of chromosomal stability, and sperm morphogenesis. Beyond its intrinsic functions in germ cells, m⁶A also contributes to the regulation of the testicular microenvironment. In sertoli cells, m⁶A is involved in maintaining blood-testis barrier integrity, RNA processing, and paracrine signaling, thereby providing structural and metabolic support for germ cell development. In Leydig cells, m⁶A regulates steroidogenesis, particularly testosterone synthesis, and participates in cellular stress responses and metabolic homeostasis. Through these mechanisms, m⁶A indirectly influences spermatogenesis by modulating the functional state of testicular somatic cells, highlighting an integrated regulatory mode that combines cell-intrinsic and microenvironment-mediated effects. Notably, distinct classes of m⁶A regulators exhibit pronounced stage-specific functions and coordinated division of labor, collectively forming a multilayered and dynamic regulatory network. Writers often display dosage- and temporal window-dependent effects; erasers contribute to stage-specific demethylation and functional compensation; while readers function through a “switch-buffer” dual-layer architecture, and RNA-binding proteins (RBPs) participate in substrate selection and post-transcriptional regulation. Importantly, emerging evidence suggests that some m⁶A-related proteins can function through noncanonical mechanisms independent of m⁶A recognition, such as intrinsic RNA-binding activity, helicase function, or ribonucleoprotein complex assembly, thereby expanding the functional landscape of the m⁶A regulatory system. Dysregulation of m⁶A machinery can lead to multiple spermatogenic defects, including impaired SSC self-renewal, meiotic arrest, abnormal chromatin remodeling, and defective sperm formation, ultimately resulting in male infertility. Despite substantial advances, several critical questions remain unresolved, including the distinction between m⁶A-dependent and -independent mechanisms, the spatiotemporal dynamics of m⁶A modifications at single-cell resolution, and the coordination and antagonism among different regulatory factors. In this review, we systematically summarize the dual regulation of spermatogenesis by germ cell-intrinsic mechanisms and the testicular microenvironment, and delineate the molecular mechanisms and stage-specific functions of the dynamic m⁶A regulatory network. We further discuss the current limitations in the field and propose feasible experimental strategies for future investigation. Collectively, this work aims to provide a comprehensive framework for understanding the epitranscriptomic regulation of spermatogenesis and to offer theoretical insights into the pathogenesis and clinical management of male infertility.

Spermatogenesis is a highly ordered and spatiotemporally regulated developmental process in the male reproductive system, during which spermatogonial stem cells (SSCs), supported by the seminiferous tubule microenvironment, sequentially undergo mitosis, meiosis, and spermiogenesis to ultimately generate structurally intact spermatozoa. This complex process is accompanied by extensive transcriptional reprogramming, chromatin remodeling, and finely tuned post-transcriptional regulation. Precise control of RNA fate is therefore essential for maintaining the continuity and fidelity of spermatogenesis, and its disruption represents a major molecular basis of male infertility. N⁶-methyladenosine (m⁶A), the most abundant internal RNA modification in eukaryotes, has emerged as a critical regulator of post-transcriptional gene expression. m⁶A methyltransferases (“writers”) catalyze the addition of a methyl group to the N⁶ position of adenosine, m⁶A demethylases (“erasers”) remove the modification, and m⁶A-binding proteins (“readers”) recognize m⁶A-modified transcripts. Through the coordinated actions of these factors, m⁶A regulates transcript fate at multiple levels, including RNA splicing, nuclear export, stability, translation, and decay. Emerging evidence indicates that m⁶A-mediated regulation is essential across multiple stages of spermatogenesis, including SSC self-renewal and differentiation, meiotic progression, maintenance of chromosomal stability, and sperm morphogenesis. Beyond its intrinsic functions in germ cells, m⁶A also contributes to the regulation of the testicular microenvironment. In sertoli cells, m⁶A is involved in maintaining blood-testis barrier integrity, RNA processing, and paracrine signaling, thereby providing structural and metabolic support for germ cell development. In Leydig cells, m⁶A regulates steroidogenesis, particularly testosterone synthesis, and participates in cellular stress responses and metabolic homeostasis. Through these mechanisms, m⁶A indirectly influences spermatogenesis by modulating the functional state of testicular somatic cells, highlighting an integrated regulatory mode that combines cell-intrinsic and microenvironment-mediated effects. Notably, distinct classes of m⁶A regulators exhibit pronounced stage-specific functions and coordinated division of labor, collectively forming a multilayered and dynamic regulatory network. Writers often display dosage- and temporal window-dependent effects; erasers contribute to stage-specific demethylation and functional compensation; while readers function through a “switch-buffer” dual-layer architecture, and RNA-binding proteins (RBPs) participate in substrate selection and post-transcriptional regulation. Importantly, emerging evidence suggests that some m⁶A-related proteins can function through noncanonical mechanisms independent of m⁶A recognition, such as intrinsic RNA-binding activity, helicase function, or ribonucleoprotein complex assembly, thereby expanding the functional landscape of the m⁶A regulatory system. Dysregulation of m⁶A machinery can lead to multiple spermatogenic defects, including impaired SSC self-renewal, meiotic arrest, abnormal chromatin remodeling, and defective sperm formation, ultimately resulting in male infertility. Despite substantial advances, several critical questions remain unresolved, including the distinction between m⁶A-dependent and -independent mechanisms, the spatiotemporal dynamics of m⁶A modifications at single-cell resolution, and the coordination and antagonism among different regulatory factors. In this review, we systematically summarize the dual regulation of spermatogenesis by germ cell-intrinsic mechanisms and the testicular microenvironment, and delineate the molecular mechanisms and stage-specific functions of the dynamic m⁶A regulatory network. We further discuss the current limitations in the field and propose feasible experimental strategies for future investigation. Collectively, this work aims to provide a comprehensive framework for understanding the epitranscriptomic regulation of spermatogenesis and to offer theoretical insights into the pathogenesis and clinical management of male infertility.

The chemical constituents in dried roots of Atractylodes macrocephala were investigated in this study. Through utilizing normal-phase silica gel and ODS column chromatography, TLC, and semi-preparative HPLC, 4 new sesquiterpenoids were purified from the ethyl acetate extract of A. macrocephala. By various spectroscopic techniques, such as 1D and 2D NMR, HR-ESI-MS, IR, UV, and CD, their structures were identified as atractylmacron A (1), 9β-hydroxyasterolide (2), atractylenolide H (3), atractylenolide J (4). Compound 1 possesses a rare 6/7 bicyclic skeleton.

Objective:To investigate the incidence of mild cognitive impairment(MCI)and malnutrition among centenarians, as well as to explore the relationship between cognitive impairment and nutritional status.Methods:A cross-sectional study was conducted between November and December 2023, involving 121 elderly individuals aged ≥ 100 years in the Baoshan District of Shanghai.The survey collected general information and included the Ascertain Dementia 8-item Questionnaire(AD8), the Mini Nutritional Assessment Short-Form(MNA-SF), and anthropometric nutritional measurements such as waist circumference(WC), hip circumference(HC), arm circumference(AC), calf circumference(CC), and grip strength.The prevalence of MCI and malnutrition among centenarians was calculated, and the correlation between MCI and MNA-SF scores, along with anthropometric nutritional measurement indicators, was analyzed.Results:The age range of centenarians was between 100 and 105 years, with an average age of 101.0±3.5 years.The majority of centenarians were female(76.9%), illiterate(58.7%), and lived with family members(73.6%).All participants had medical insurance(100%).Most had no history of long-term smoking 118(97.5%), long-term alcohol consumption 108(89.3%), long-term use of health supplements 109(90.1%), long-term tea or coffee habits 114(94.2%), chronic medical conditions 84(69.4%), or family history of dementia 102(84.3%).Additionally, 62(51.2%)reported their health status over the past year as general.According to the AD8 screening results, the negative and positive detection rates of MCI in centenarians were 79(65.3%)and 47(34.7%), respectively.Based on the MNA-SF scoring results, the detection rates of normal nutrition, malnutrition risk, and malnutrition among centenarians were 36(29.8%), 61(50.4%), and 24(19.8%), respectively.There was a statistically significant difference in AC between the non-MCI group and the MCI group among centenarians( t=0.01, P=0.03).The AD8 scores of centenarians were significantly negatively correlated with AC, CC, and MNA-SF scores( r=-0.20, r=-0.26, r=-0.29; all P<0.05). Conclusions:The cognitive function of centenarians is associated with their nutritional status, indicating that higher cognitive abilities correlate with better nutritional status.

Barrett's esophagus(BE),a precancerous state of esophageal adenocarcinoma,poses a major challenge for prevention and treatment owing to its complex mechanism of inflammation-cancer transformation and the lack of effective clinical treatment and torsion strategies.Building upon the"preventing disease progression"theory,this study aimed to address the critical clinical challenge of intercepting the pathological progression during the inflammation-cancer transformation of BE by proposing an innovative"two critical nodes-three stages"pathomechanism framework.The pathogenesis of BE originates from liver depression and qi stagnation.The pathological progression evolves through two critical nodes:liver depression transforming into heat and heat transforming into blood stasis,representing a three-stage evolutionary pattern of qi stagnation,heat transformation,and blood stasis formation.Acidic bile salts,acting as a pathogenic toxin,permeate the entire process and catalyze carcinogenesis.Based on this understanding,the therapeutic principles of"treatment from the liver"and"truncation and torsion"were established,emphasizing stage-specific interventions.For the qi stagnation stage,treatment focuses on soothing the liver and regulating qi,as well as moistening,harmonizing,and descending the qi.This is achieved by combining modified Chaihu Shugan Powder with Xuanfu Daizhe Decoction,while using pungent and drying herbs cautiously and supplementing them with light and floral herbs.In the heat transformation stage,the strategy aims to clear the liver and drain heat while protecting yin and harmonizing the stomach,employing modified Huaganjian combined with Yiguanjian and supplemented with Jinlingzi Powder to clear depressed fire.For the blood stasis formation stage,treatment involves activating blood and resolving stasis,combined with supporting healthy qi and removing toxins.This is achieved using a modified Gexia Zhuyu Decoction,supplemented with Liujunzi Decoction,and additions such as Radix Salviae Miltiorrhizae and turtle carapace to disperse nodules and reduce masses.This theoretical framework establishes a diagnostic and therapeutic model characterized by the integration of disease mechanisms with pathology and the mutual reference of macro-level signs with micro-level indicators.It provides a comprehensive clinical practice pathway,complete with principles,methods,formulas,and herbs,for the stage-specific interception of inflammation-cancer transformation in BE using traditional Chinese medicine.

BACKGROUND:Some research has suggested that regulation of gut microbiota may influence the course of intervertebral disc degeneration.However,the causal relationship of gut microbiota on intervertebral disc degeneration is unknown.OBJECTIVE:To assess the potential causal relationship between gut microbiota and intervertebral disc degeneration using a Mendelian randomization method.METHODS:Genome-wide association analysis summary statistics for 473 gut microbiota and genome-wide association analysis summary data for intervertebral disc degeneration from the R11 of the FinnGen database(46 205 cases of intervertebral disc degeneration and 322 314 controls)from the most recent publicly available publication were applied.Inverse variance weighting,MR-Egger regression,weighted median,weighted modeling,and simple modeling were used to investigate the causal relationship between gut microbiota and intervertebral disc degeneration.Sensitivity analyses were used to test whether the results of Mendelian randomization analyses were reliable.Reverse Mendelian randomization was performed with all gut microbiota as the outcomes for effect analysis and sensitivity analysis.RESULTS AND CONCLUSION:(1)The results of the inverse variance weighting method of the forward Mendelian randomization method showed that the order Trichosporonaceae,the family UBA-6960,the family Anaerobes thermophilus,the family Salmonellaceae,the genus Pseudomonas tufts,the species Gordonella and the species Euclidia showed a positive correlation with intervertebral disc degeneration.The order Spirochaetes,the order Pseudomonas,the family Spirochaetaceae,the genus CAG-776,the genus Helicobacter,the species CAG-448 sp003150135,the species CAG-776 sp000438195,the species Brautella-A sp000285855 and the species Hanson's Brautella showed a negative correlation with intervertebral disc degeneration.(2)The results of reverse Mendelian randomization showed that intervertebral disc degeneration was positively correlated with the genus Bartonella rosea,the genus Geobacillus C,the species Escherichia fumigatus,the species Propionibacterium fumigatus,the species UBA-1777 sp900319835,the species Pseudomonas aeruginosa and the species Bacillus subtilis,while negatively correlated with the species Streptomyces mingoldii,the species Prevotella sp000434975,the species Brault's A sp000285855,the species CAG-194 sp002441865 and the species CAG-590 sp000431135.(3)No heterogeneity or horizontal pleiotropy was found in the two-way sensitivity analysis.(4)The results described above indicate that the causal relationship between gut microbiota and intervertebral disc degeneration based on the Finnish database contributes to the exploration on new biomarkers for the early prediction and treatment of intervertebral disc degeneration in clinical practice.In addition,the establishment of a large database and the integration of medical data from multiple centers can be drawn upon in biomedical research in China to provide a solid foundation for studying the relationship between gut microbiota and intervertebral disc degeneration.We will strengthen communication and cooperation with research teams in other countries to jointly promote the research on the relationship between gut microbiota and diseases and contribute to the development of global medicine.

BACKGROUND:Unique advantages of 3D printing technology have opened up new ideas for the development of stomatology.OBJECTIVE:To summarize the application progress of 3D printing technology in stomatology.METHODS:The relevant articles were searched in CNKI and PubMed by computer.Classification search was performed using"3D printing,oral science"as Chinese search terms.Keyword search was conducted using"three-dimensional printing,stomatology,dentistry,prosthodontics,oral implant,orthodontics,oral and maxillofacial surgery,dental pulp disease,periodontitis"as English search terms.The literature that was not related to the theme of the article was initially excluded after reading.According to the inclusion and exclusion criteria,54 articles were finally included for review.RESULTS AND CONCLUSION:In the field of stomatology,the application scope of 3D printing technology is rapidly expanding,gradually replacing the traditional clinical diagnosis and treatment methods.Through the combination of digital technology and advanced material science,3D printing can accurately create 3D models,providing personalized solutions for the treatment of oral diseases,ensuring that doctors can carry out detailed planning and preview before surgery,and improve the safety of surgery.3D printing technology has shown significant advantages in customized denture production,personalized implantation,bracket-free invisible orthodontics,etc.Based on this technology,doctors can implement accurate design and production according to the patient's oral structure and needs,bringing patients a good treatment experience and prognosis.3D printing technology has also shown great potential in minimally invasive endodontic treatment and periodontal tissue regeneration,3D printed scaffolds and implants can provide a suitable environment for stem cells to promote the regeneration and repair of periodontal tissues,but at present,3D printing is still in the development stage of regenerative therapy,and more research and practice are needed to verify the effect and safety of its clinical application.

Objective To explore the roles of the mechanoreceptor Yes-associated protein 1(YAP1)and piezo type mechanosensitive ion channel component 2(PIEZO2)in mechanotransduction in mouse bladder urothelial cells.Methods Mouse bladder urothelial cells were subjected to mechanical stretching using the FX-6000T cell stretching system and treated with the YAP1-specific inhibitor verteporfin(VP).The expressions of PIEZO2,YAP1 and connective tissue growth factor(CTGF)at the mRNA and protein levels,as well as changes in cellular adenosine triphosphatase(ATP)concentration,were detected using reverse transcription quantitative PCR(RT-qPCR)and Western blotting(WB).Results After stretching stimulation,under the fluorescence microscope,it was observed that the diameter length of the stretched cells were longer than that before stretching,and the difference was statistically significant(P＜0.05).The expressions of YAP1,PIEZO2 and CTGF at the mRNA and protein levels were increased in the stretched group compared to those of the non-stretched group(P＜0.05).VP effectively reduced the expressions of YAP1,PIEZO2 and CTGF at the mRNA and protein levels after stretching stimulation(P＜0.05).Stretching stimulation significantly increased the intracellular ATP concentration,while VP was able to inhibit the increase in ATP concentration,with a statistically significant difference(P＜0.000 1).Conclusion Stretching stimulation increased the expressions of YAP1 and PIEZO2 in bladder urothelial cells and promoted the release of ATP;verteporfin inhibited the increase in YAP1 activity and the overexpression of PIEZO2 caused by stretching,thereby reducing the release of ATP.It is suggested that mouse bladder urothelial cells may primarily sense mechanical signals through the YAP1-PIEZO2-ATP pathway.

Instrument separation is a critical complication during root canal therapy, impacting treatment success and long-term tooth preservation. The etiology of instrument separation is multifactorial, involving the intricate anatomy of the root canal system, instrument-related factors, and instrumentation techniques. Instrument separation can hinder thorough cleaning, shaping, and obturation of the root canal, posing challenges to successful treatment outcomes. Although retrieval of separated instrument is often feasible, it carries risks including perforation, excessive removal of tooth structure and root fractures. Effective management of separated instruments requires a comprehensive understanding of the contributing factors, meticulous preoperative assessment, and precise evaluation of the retrieval difficulty. The application of appropriate retrieval techniques is essential to minimize complications and optimize clinical outcomes. The current manuscript provides a framework for understanding the causes, risk factors, and clinical management principles of instrument separation. By integrating effective strategies, endodontists can enhance decision-making, improve endodontic treatment success and ensure the preservation of natural dentition.
Humans ; Root Canal Therapy/adverse effects* ; Consensus ; Root Canal Preparation/adverse effects*

To investigate the molecular mechanisms underlying the mechanosensitive ion channel PI-EZO2 in osteoarthritis(OA),we developed a lentiviral vector for endogenous PIEZO2 overexpression and established a stable PIEZO2-high-expressing immortalized human primary chondrocyte line.By map-ping the open reading frame of the PIEZO2 locus and designing sequence-specific sgRNA,we employed the CRISPR/Cas9 synergistic activation mediator(SAM)system to precisely integrate transcriptional ac-tivation elements into the PIEZO2 promoter region.Lentiviral-mediated targeted genomic integration en-sured endogenous PIEZO2 overexpression,confirmed by mCherry fluorescence tracing coupled with flow cytometric sorting,which revealed membrane-specific localization of PIEZO2 protein(localization effi-ciency:78.49％).Quantitative PCR demonstrated a 17-fold upregulation of PIEZO2 mRNA,while Western blotting validated enhanced membrane-localized protein expression.Strikingly,PIEZO2-overex-pressing chondrocytes exhibited hallmark OA metabolic phenotypes compared to wild-type controls:typeⅡ collagen mRNA expression decreased to 50％of baseline levels,whereas matrix metalloproteinase 13(MMP13)mRNA surged by 20-fold.These alterations recapitulated the pathological matrix metabolic phenotype observed in biomechanical OA models induced by cyclic mechanical stress(10％strain,0.5 Hz,8 h/day for 2 consecutive days).Collectively,we successfully generated a human chondrocyte model with stable PIEZO2 overexpression,which faithfully mirrors mechanotransduction-driven OA progression.This engineered cellular system provides a robust platform for dissecting PIEZO2-mediated mechanosig-naling networks and advancing targeted therapeutic discovery.