1.The Role and Molecular Mechanism of N⁶-methyladenosine Modification in Spermatogenesis
Shi-Qi MENG ; Wen-Ting LU ; Xu CHENG ; Fan YANG ; Chang-Min NIU ; Ying ZHEGN
Progress in Biochemistry and Biophysics 2026;53(5):1297-1312
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.
2.The Role and Molecular Mechanism of N⁶-methyladenosine Modification in Spermatogenesis
Shi-Qi MENG ; Wen-Ting LU ; Xu CHENG ; Fan YANG ; Chang-Min NIU ; Ying ZHEGN
Progress in Biochemistry and Biophysics 2026;53(5):1297-1312
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.
3.Survival impact of radiotherapy for patients with de novo metastatic rectal cancer
Harvey Yu-Li SU ; Yun-Hsuan LIN ; Ko-Chao LEE ; Yueh-Ming LIN ; Chun-Chieh HUANG ; Eng-Yen HUANG ; Tai-Jan CHIU ; Shih-Yu HUANG ; Chia-Che WU ; Chang-Ting LIN ; Ming-Chun KUO ; Kai-Lung TSAI
Annals of Coloproctology 2026;42(1):94-102
Purpose:
Metastatic rectal cancer (mRC) is a highly lethal and complex disease that demands a multidisciplinary treatment approach. However, the clinical effectiveness of radiotherapy (RT) for de novo mRC remains controversial and uncertain.
Methods:
This retrospective cohort study examined medical records from Kaohsiung Chang Gung Memorial Hospital for patients with histologically confirmed de novo mRC diagnosed between January 2015 and December 2020. All patients received standard systemic therapy and radical surgery when feasible. The primary outcome, overall survival (OS), was assessed using the Kaplan-Meier method. Multivariable analysis was performed using a Cox regression model.
Results:
Among 271 patients included in the analysis, 117 received RT and 154 did not. The median OS was significantly longer in the RT group compared with the non-RT group (27.8 months vs. 21.9 months; P=0.046). Multivariate analysis identified several independent predictors of OS: age ≥65 years (hazard ratio [HR], 1.69; 95% confidence interval [CI], 1.26–2.27; P=0.001), primary tumor resection (HR, 2.62; 95% CI, 1.90–3.61; P<0.001), M1b or M1c disease (HR, 1.97; 95% CI, 1.44–2.69; P<0.001), and receipt of RT (HR, 1.41; 95% CI, 1.02–1.94; P=0.036).
Conclusion
RT significantly improves OS in patients with mRC, underscoring its role in treatment strategies. These findings support its inclusion in therapeutic protocols and highlight the need for larger, multicenter trials to confirm and extend these results.
4.Eccentric Cycling Improves Cardiopulmonary Fitness, Respiratory Function, and Quality of Life in Chronic Kidney Disease: A Randomized Controlled Trial
Yu-Ting HUANG ; Hsin-Yeh LEE ; Hui-Ching CHENG ; Hsin-Lun YANG ; Ching-Hsia HUNG ; Chien-Chou SU ; Yu-Tzu CHANG ; Chien-Yao SUN ; Kun-Ling TSAI
Annals of Rehabilitation Medicine 2026;50(2):105-116
Objective:
To compare the effects of eccentric cycling (ECC), concentric cycling (CON), and standard care (CTL) on cardiopulmonary capacity, respiratory health, and quality of life (QoL) in patients with chronic kidney disease (CKD).
Methods:
Thirty-one CKD patients were divided into the CTL, CON, and ECC groups. The CON and ECC groups participated in 8-week, 24-session cycling programs. Outcomes were assessed through cardiopulmonary exercise tests, respiratory function tests, and the 36-Item Short Form Survey Instrument questionnaire.
Results:
The ECC group achieved significant improvements in maximal oxygen uptake, while the CTL group showed a decline. For oxygen uptake efficiency slope, significant changes were observed only in the ECC group, with a group-by-time interaction effect compared to CTL. Furthermore, the ECC group demonstrated the most significant increase in diaphragm movement and a significant increase in diaphragm thickness, with comparisons indicating that ECC outperformed both CTL and CON. Regarding QoL, the ECC group exhibited significantly greater improvements in Physical Component Summary and Mental Component Summary, with statistically significant differences compared with the CTL and CON groups.
Conclusion
ECC is a low-effort, high-benefit exercise modality that significantly enhances cardiopulmonary fitness, respiratory function, and QoL in patients with CKD.
5.Prognostic Utility of the Albumin-to-Alkaline Phosphatase Ratio in Head and Neck Cancer: A Systematic Review and Meta-Analysis
Yun-Ting WANG ; Adarsh KUDVA ; Yen-Ting LU ; Liang-Tseng KUO ; Chia-Hsuan LAI ; Yuan-Hsiung TSAI ; Chun-Ta LIAO ; Ku-Hao FANG ; Chung-Jan KANG ; Ethan I. HUANG ; Cheng-Ming HSU ; Geng-He CHANG ; Ming-Shao TSAI ; Yao-Te TSAI
Clinical and Experimental Otorhinolaryngology 2026;19(1):45-54
Objectives:
. The prognostic value of the pretreatment albumin-to-alkaline phosphatase ratio (AAPR) in head and neck cancer (HNC) remains uncertain. This meta-analysis aimed to evaluate the predictive role of AAPR for survival outcomes in patients with HNC.
Methods:
. A comprehensive search of the Cochrane Library, PubMed, and Embase databases was conducted to identify relevant studies published up to July 30, 2024. We included studies on AAPR and survival outcomes in HNC patients.
Results:
. Eight studies comprising 1,737 HNC patients were analyzed using random-effects models. Lower AAPR values were significantly correlated with worse overall survival (hazard ratio [HR], 2.08), progression-free survival (HR, 2.00), and disease-free survival (HR, 2.18). Sensitivity analyses confirmed the robustness of these results, with no significant publication bias detected.
Conclusion
. Our findings suggest that pretreatment AAPR could serve as a valuable and cost-effective prognostic indicator in HNC, potentially aiding clinicians in risk stratification and treatment decision-making. However, additional validation studies are warranted to confirm its clinical applicability.
6.Corporate Governance and Workplace Mental Health Practices: The Mediating Role of Structured Occupational Safety and Health Engagement
Ro-Ting LIN ; Lung-Chang CHIEN ; Chieh-Wen CHANG ; Yu-Chi LIAO ; Tomohisa NAGATA
Safety and Health at Work 2026;17(1):33-39
Background:
This study examines whether stronger corporate governance is associated with workplace mental health practices and whether this relationship is mediated by a structured sequence of occupational safety and health (OSH) engagement: recognition, goal-setting, and implementation.
Methods:
We analyzed 134 listed companies in Taiwan that published sustainability reports and received corporate governance evaluations between 2014 and 2023. Governance scores―based on shareholder rights, board functioning, transparency, and sustainability―were dichotomized into high vs. low categories. Workplace mental health practices were measured using 24 binary indicators across planning, provision, and reporting. OSH engagement was conceptualized in three stages based on Global Reporting Initiative 403 guidelines, with composite indicators derived via grouped weighted quantile sum regression. Associations were analyzed using generalized linear mixed-effects and serial mediation models.
Results:
Compared to companies ranked low in corporate governance, those ranked high had a higher likelihood of adopting mental health practices. OSH goal-setting and implementation showed significant positive associations, whereas recognition did not. Serial mediation analysis showed that 83% of the total effect of corporate governance on mental health practices was direct, while 17% was mediated through structured OSH engagement, primarily via implementation. Recognition showed a nonsignificant effect but initiated significant sequential pathways via goal-setting and implementation.Goal-setting functioned as a bridge within these chains.
Conclusion
Corporate governance plays a central role in advancing workplace mental health practices.While most effects are direct, structured OSH engagement helps translate governance priorities into sustained organizational actions that embed mental health into routine practice.
7.The first record of Anopheles messeae (Diptera: Culicidae) parasitized by water mites in China
Xue-ru CHEN ; Wen-zhen YAO ; Yu-hao LI ; Gui-chang LI ; Tao MENG ; Qun-ling FENG ; Xin-hui LIU ; Li-hong QIAO ; Xiang-ting WU ; Xue-feng ZHANG ; Cheng-lin LI ; Xue-cheng DONG ; Da-wei WANG ; Xiao-yan SI ; Yu-hong GUO
Acta Parasitologica et Medica Entomologica Sinica 2026;33(1):53-57
Objective This study reports on the obligatory parasitism of water mites Arrenurus sp. on Anopheles messeae at the Manzhouli Port, Inner Mongolia, China. Methods Duing July 2024, a survey on the mosquito diversity was conducted at the Manzhouli Port. Captured mosquitoes and their ectoparasites were identified to species level. Results A total of 1840 adult mosquitoes were collected, representing species from three genera: Culex(Cx. modestus, Cx. pipiens pallens), Aedes(Ae. dorsalis, Ae. flavidorsalis, Ae. flavescens), and Anopheles (An. messeae). Among all the mosqutioes specimens,3 out of 150 captured An. messeae were found to carry ectoparasitic mites, with number of 2,4,27 mites separately. Morphological and molecular identification reached the same result as water mites(Hydrachnidiae, Hydracrina). COI gene sequence showed 94% similarity with the closest species Arrenurus truncatellus. Conlusions Literature review suggests water mites are host-specific parasitism of mosquito species and herein with the first record of Arrenurus sp. parasiting on An. Messeae in the most high-latitude region globally.
8.Molecular Mechanisms of Intraflagellar Transport in Regulating ciliogenesis and Ciliopathies
Ting-Ting GE ; Fan YANG ; Chang-Min NIU ; Ying ZHENG
Progress in Biochemistry and Biophysics 2026;53(8):2179-2193
Intraflagellar transport (IFT) is a core mechanism for ciliary assembly, length maintenance, ciliary proteome homeostasis and signal transduction. Most proteins required for ciliary structure and function are synthesized in the cytoplasm. Because the ciliary compartment is separated from the cell body by the selective barrier of the transition zone, these proteins cannot freely equilibrate between the cytoplasm and the cilium. Consequently, axonemal components, membrane proteins and signaling molecules must be actively imported into cilia, retrieved from the ciliary compartment, and recycled or degraded through highly ordered transport and sorting pathways. The IFT system is mainly composed of the IFT-A complex, IFT-B complex, kinesin-2, dynein-2 and the Bardet-Biedl syndrome protein complex (BBSome). Through coordinated anterograde and retrograde transport, these modules mediate the dynamic trafficking of different classes of ciliary cargoes. Anterograde transport delivers structural and membrane-associated components from the ciliary base toward the ciliary tip, whereas retrograde transport retrieves IFT components and selected cargoes back toward the ciliary base and cytoplasm. In this way, IFT not only supports the construction of the axoneme but also contributes to the maintenance of ciliary composition and the regulation of ciliary signaling activity. In recent years, advances in cryo-electron microscopy, in situ cryo-electron tomography and single-molecule imaging have greatly improved our understanding of the molecular mechanisms underlying IFT. These approaches have revealed how IFT trains are assembled at the ciliary base, how they move along axonemal microtubule tracks, how they undergo directional switching at the ciliary tip, and how cargoes are retrieved and recycled. Among the IFT modules, IFT-B acts as the major scaffold of IFT trains. It participates in cargo loading, motor coupling and initiation of anterograde transport. IFT-A is involved in retrograde transport, membrane protein adaptor function and train remodeling. The BBSome, through reversible association with the IFT system, regulates ciliary membrane protein sorting, signaling receptor clearance and renewal of the ciliary proteome. These functions indicate that the IFT machinery is not a simple linear transport pathway, but rather a dynamic and reconfigurable transport system. The conversion of transport direction is a key step in the IFT cycle. This process is closely associated with disassembly of anterograde trains, dissociation of kinesin-2, activation of dynein-2 at the ciliary tip and reassembly of retrograde trains. In terms of pathogenic mechanisms, IFT abnormalities may cause ciliopathies through four major pathways: defects in ciliary assembly and structure, abnormal localization of ciliary cargoes, dysregulation of signaling pathways, and impaired cargo unloading and retrieval. These defects can affect multiple organ systems, including the retina, kidney, skeleton, respiratory tract, reproductive system, and neuro-metabolic system. Current therapeutic strategies are still mainly based on symptomatic support and maintenance of organ function. Overall, IFT is a dynamic transport system jointly regulated by axonemal structure, motor activity, cargo selection and cellular signaling. It links ciliary architecture with protein turnover and signaling regulation, thereby playing a fundamental role in both ciliary homeostasis and ciliopathy pathogenesis. Further elucidation of IFT regulatory mechanisms and their relationships with disease phenotypes will help promote mechanism-based classification, genetic diagnosis and precision intervention for ciliopathies.
9.Mechanism of Aerobic Exercise in Delaying Brain Aging in Aging Mice by Regulating Tryptophan Metabolism
De-Man ZHANG ; Chang-Ling WEI ; Yuan-Ting ZHANG ; Yu JIN ; Xiao-Han HUANG ; Min-Yan ZHENG ; Xue LI
Progress in Biochemistry and Biophysics 2025;52(6):1362-1372
ObjectiveTo explore the molecular mechanism of aerobic exercise to improve hippocampal neuronal degeneration by regulating tryptophan metabolic pathway. Methods60 SPF-grade C57BL/6J male mice were divided into a young group (2 months old, n=30) and a senile group (12 months old, n=30), and each group was further divided into a control group (C/A group, n=15) and an exercise group (CE/AE group, n=15). An aerobic exercise program was used for 8 weeks. Learning memory ability was assessed by Y-maze, and anxiety-depression-like behavior was detected by absent field experiment. Hippocampal Trp levels were measured by GC-MS. Nissl staining was used to observe the number and morphology of hippocampal neurons, and electron microscopy was used to detect synaptic ultrastructure. ELISA was used to detect the levels of hippocampal Trp,5-HT, Kyn, KATs, KYNA, KMO, and QUIN; Western blot was used to analyze the activities of TPH2, IDO1, and TDO enzymes. ResultsGroup A mice showed significant decrease in learning and memory ability (P<0.05) and increase in anxiety and depressive behaviors (P<0.05); all of AE group showed significant improvement (P<0.05). Hippocampal Trp levels decreased in group A (P<0.05) and increased in AE group (P<0.05). Nidus vesicles were reduced and synaptic structures were degraded in group A (P<0.05), and both were significantly improved in group AE (P<0.05). The levels of Trp, 5-HT, KATs, and KYNA were decreased (P<0.05) and the levels of Kyn, KMO, and QUIN were increased (P<0.05) in group A. The activity of TPH2 was decreased (P<0.05), and the activities of IDO1 and TDO were increased (P<0.05). The AE group showed the opposite trend. ConclusionThe aging process significantly reduces the learning memory ability and increases the anxiety-depression-like behavior of mice, and leads to the reduction of the number of nidus vesicles and degenerative changes of synaptic structure in the hippocampus, whereas aerobic exercise not only effectively enhances the spatial learning memory ability and alleviates the anxiety-depression-like behavior of aging mice, but also improves the morphology and structure of neurons in hippocampal area, which may be achieved by the mechanism of regulating the tryptophan metabolic pathway.
10.Upregulation of NR2A in Glutamatergic VTA Neurons Contributes to Chronic Visceral Pain in Male Mice.
Meng-Ge LI ; Shu-Ting QU ; Yang YU ; Zhenhua XU ; Fu-Chao ZHANG ; Yong-Chang LI ; Rong GAO ; Guang-Yin XU
Neuroscience Bulletin 2025;41(12):2113-2126
Chronic visceral pain is a persistent and debilitating condition arising from dysfunction or sensitization of the visceral organs and their associated nervous pathways. Increasing evidence suggests that imbalances in central nervous system function play an essential role in the progression of visceral pain, but the exact mechanisms underlying the neural circuitry and molecular targets remain largely unexplored. In the present study, the ventral tegmental area (VTA) was shown to mediate visceral pain in mice. Visceral pain stimulation increased c-Fos expression and Ca2+ activity of glutamatergic VTA neurons, and optogenetic modulation of glutamatergic VTA neurons altered visceral pain. In particular, the upregulation of NMDA receptor 2A (NR2A) subunits within the VTA resulted in visceral pain in mice. Administration of a selective NR2A inhibitor decreased the number of visceral pain-induced c-Fos positive neurons and attenuated visceral pain. Pharmacology combined with chemogenetics further demonstrated that glutamatergic VTA neurons regulated visceral pain behaviors based on NR2A. In summary, our findings demonstrated that the upregulation of NR2A in glutamatergic VTA neurons plays a critical role in visceral pain. These insights provide a foundation for further comprehension of the neural circuits and molecular targets involved in chronic visceral pain and may pave the way for targeted therapies in chronic visceral pain.
Animals
;
Male
;
Visceral Pain/metabolism*
;
Up-Regulation/physiology*
;
Ventral Tegmental Area/metabolism*
;
Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors*
;
Neurons/drug effects*
;
Mice, Inbred C57BL
;
Mice
;
Proto-Oncogene Proteins c-fos/metabolism*
;
Chronic Pain/metabolism*
;
Glutamic Acid/metabolism*


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