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.

RNA-binding proteins (RBPs) are ubiquitous components within cells, fulfilling essential functions in a myriad of biological processes. These proteins interact with RNA molecules to regulate gene expression at various levels, including transcription, splicing, transport, localization, translation, and degradation. Understanding the intricate network of RBP-RNA interactions is crucial for deciphering the complex regulatory mechanisms that govern cellular function and organismal development. Ultravidet (UV) cross-linking and immunoprecipitation (CLIP) stands out as a powerful approach designed to map the precise locations where RBPs bind to RNA. By using UV light to create covalent bonds between proteins and RNA, followed by immunoprecipitation to isolate the protein-RNA complexes, researchers can identify the direct targets of specific RBPs. The advent of high-throughput sequencing technologies has revolutionized CLIP, enabling the identification of not only the types but also the exact sequences of RNA bound by RBPs on a genome-wide scale. The evolution of CLIP has led to the development of specialized variants, each with unique features that address specific challenges and expand the scope of what can be studied. High-throughput sequencing CLIP (HITS-CLIP) was one of the first advancements, significantly increasing the throughput and resolution of RNA-protein interaction mapping. Photoactivatable-ribonucleoside-enhanced CLIP (PAR-CLIP) introduced the use of photoactivatable ribonucleosides to enhance cross-linking efficiency and specificity, reducing background noise and improving the detection of low-abundance RNA-protein interactions. Individual-nucleotide resolution CLIP (iCLIP) further refined the technique, achieving unprecedented precision by resolving individual nucleotides involved in RBP binding, which is particularly valuable for studying the fine details of RNA structure and function. Despite the remarkable progress, there remains room for improvement in CLIP technology. Researchers continue to seek methods to increase sensitivity, reduce technical variability, and improve the reproducibility of results. Advances in sample preparation, data analysis algorithms, and computational tools are critical for addressing these challenges. Moreover, the application of CLIP to more diverse biological systems, including non-model organisms and clinical samples, requires the development of tailored protocols and the optimization of existing ones. Looking forward, the field of RNA biology is poised to benefit greatly from ongoing innovations in CLIP technology. The exploration of non-canonical RNA-protein interactions, such as those involving long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), promises to reveal new layers of cellular regulation and may lead to the discovery of novel therapeutic targets. Furthermore, integrating CLIP data with other omics approaches, such as proteomics and metabolomics, will provide a more comprehensive understanding of the dynamic interplay between RNA and its binding partners within the cell. In conclusion, the continuous refinement and expansion of CLIP techniques have not only deepened our knowledge of RNA biology but have also opened up new avenues for investigating the molecular underpinnings of health and disease. As the technology matures, it is expected to play an increasingly pivotal role in both basic and applied research, contributing to the advancement of medical science and biotechnology.

Objectives: Hypoparathyroidism (HP) is a rare endocrine disorder caused by parathyroid hormone (PTH) defi ciency. The PTH is a candidate gene for familial isolated hypoparathyroidism (FIH). This study aimed to investigate the pathogenicity of two novel rare variants (RVs) ofPTH through in vitro functional study. Methods: Targeted next-generation sequencing was used to identify candidate gene mutations. Clinical data were retrospectively collected. Wild-type (WT) PTH was used as a template for site-directed mutagenesis to create mutant eukaryotic expression plasmids, which were transfected into cells. Treated with or without 4-phenylbu tyric acid (4-PBA), the levels of intact PTH (iPTH) and PTH (1-84) were measured by chemiluminescence, and protein expression was assessed using Western blotting. Results: Two patients carrying PTH mutations (c.154G > A: p.Val52Ile, c.270G > T: p.Leu90Phe) were identified.Patient 1, a 45-year-old male, presented with carpal and pedal numbness, muscle cramps, and low serum calcium (1.29 mmol/L). Patient 2, a 12-year-old female, had muscle twitches, convulsions, low calcium (1.50 mmol/L), and iPTH of 4 pg/mL. The iPTH or PTH (1-84) levels in the medium transfected with mutant Val52Ile and Leu90Phe PTH decreased by 31%–38%, and 51%–96% compared to WT (allP < 0.05), which were not rescued by 4-PBA. No significant changes in intracellular PTH expression were observed. Conclusions In this study, two novel RVs of PTH(Val52Ile and Leu90Phe) were identified that may impair hormone synthesis and secretion. Our study has broadened the mutation spectrum of the PTH and shed light on potential mechanisms underlying FIH.

Objectives: Hypoparathyroidism (HP) is a rare endocrine disorder caused by parathyroid hormone (PTH) defi ciency. The PTH is a candidate gene for familial isolated hypoparathyroidism (FIH). This study aimed to investigate the pathogenicity of two novel rare variants (RVs) ofPTH through in vitro functional study. Methods: Targeted next-generation sequencing was used to identify candidate gene mutations. Clinical data were retrospectively collected. Wild-type (WT) PTH was used as a template for site-directed mutagenesis to create mutant eukaryotic expression plasmids, which were transfected into cells. Treated with or without 4-phenylbu tyric acid (4-PBA), the levels of intact PTH (iPTH) and PTH (1-84) were measured by chemiluminescence, and protein expression was assessed using Western blotting. Results: Two patients carrying PTH mutations (c.154G > A: p.Val52Ile, c.270G > T: p.Leu90Phe) were identified.Patient 1, a 45-year-old male, presented with carpal and pedal numbness, muscle cramps, and low serum calcium (1.29 mmol/L). Patient 2, a 12-year-old female, had muscle twitches, convulsions, low calcium (1.50 mmol/L), and iPTH of 4 pg/mL. The iPTH or PTH (1-84) levels in the medium transfected with mutant Val52Ile and Leu90Phe PTH decreased by 31%–38%, and 51%–96% compared to WT (allP < 0.05), which were not rescued by 4-PBA. No significant changes in intracellular PTH expression were observed. Conclusions In this study, two novel RVs of PTH(Val52Ile and Leu90Phe) were identified that may impair hormone synthesis and secretion. Our study has broadened the mutation spectrum of the PTH and shed light on potential mechanisms underlying FIH.

Objectives: Hypoparathyroidism (HP) is a rare endocrine disorder caused by parathyroid hormone (PTH) defi ciency. The PTH is a candidate gene for familial isolated hypoparathyroidism (FIH). This study aimed to investigate the pathogenicity of two novel rare variants (RVs) ofPTH through in vitro functional study. Methods: Targeted next-generation sequencing was used to identify candidate gene mutations. Clinical data were retrospectively collected. Wild-type (WT) PTH was used as a template for site-directed mutagenesis to create mutant eukaryotic expression plasmids, which were transfected into cells. Treated with or without 4-phenylbu tyric acid (4-PBA), the levels of intact PTH (iPTH) and PTH (1-84) were measured by chemiluminescence, and protein expression was assessed using Western blotting. Results: Two patients carrying PTH mutations (c.154G > A: p.Val52Ile, c.270G > T: p.Leu90Phe) were identified.Patient 1, a 45-year-old male, presented with carpal and pedal numbness, muscle cramps, and low serum calcium (1.29 mmol/L). Patient 2, a 12-year-old female, had muscle twitches, convulsions, low calcium (1.50 mmol/L), and iPTH of 4 pg/mL. The iPTH or PTH (1-84) levels in the medium transfected with mutant Val52Ile and Leu90Phe PTH decreased by 31%–38%, and 51%–96% compared to WT (allP < 0.05), which were not rescued by 4-PBA. No significant changes in intracellular PTH expression were observed. Conclusions In this study, two novel RVs of PTH(Val52Ile and Leu90Phe) were identified that may impair hormone synthesis and secretion. Our study has broadened the mutation spectrum of the PTH and shed light on potential mechanisms underlying FIH.

Lactate, with a chemical formula of C₃H₆O₃, is an intermediate product of glucose metabolism in the body and a raw material for hepatic gluconeogenesis. Under physiological resting conditions, the body mainly relies on aerobic oxidation of sugar and fat for energy supply, so the blood lactate concentration is lower. However, during exercise, the enhanced glycolysis in skeletal muscles leads to the significant release of lactate into the bloodstream, causing a marked increase in blood lactate concentration. Traditionally, lactate has been regarded as a metabolic waste product of glycolysis and a contributor to exercise-induced fatigue. Nevertheless, recent studies have revealed that, in humans, lactate is a major vehicle for carbohydrate carbon distribution and metabolism, serving not only as an energy substance alongside glucose but also as a vital component in various biological pathways involved in cardiac energetics, muscle adaptation, brain function, growth and development, and inflammation therapy. Two primary pathways can elevate lactate levels in neurons during exercise. One is peripheral skeletal muscle-derived lactate, which can enter the bloodstream and cross the blood-brain barrier into the brain with the assistance of monocarboxylate transporters (MCTs) from the solute carrier family 16 (SLC16). The other is the central brain-derived pathway. During exercise, neuronal activity is enhanced, promoting the secretion of neuroactive substances such as glutamate, norepinephrine, and serotonin in the brain. This activates astrocytes to break down glycogen into lactate and stimulates glutamate from the presynaptic terminal into the synaptic cleft. It upregulates the glucose transport protein-1 (GLUT-1) expression, allowing astrocytes to convert glucose into lactate through glycolysis. The lactate is produced via peripheral pathways and central pathways during exercise are transported by astrocyte membrane monocarboxylate transporters MCT1 and MCT4 to the extracellular space, where neurons take it up through neuronal cell membrane MCT2. The lactate in neurons can serve as an alternative energy source of glucose for neuronal functional activities, meeting the increased energy demands of synaptic activity during exercise, and maintaining energy balance and normal physiological function in the brain. Additionally, acting as a signaling molecule lactate can enhance synaptic plasticity through the SIRT1/PGC-1α/FNDC5 and ERK1/2 signaling pathways, lactate can promote angiogenesis by upregulating VEGF-A expression through the PI3K/Akt and ERK1/2 signaling pathways, stimulate neurogenesis via the Akt/PKB signaling pathway, and reduce neuroinflammation through activation of the “lactate timer”. Overall, lactate contributes to the protection of neurons, the promotion of learning and memory, the enhancement of synaptic plasticity, and the reduction of neuroinflammation in the nervous system. While lactate may serve as a potential mediator for information exchange between the peripheral and central nervous systems during exercise, further experimental research is needed to elucidate its action mechanisms in the nervous system. In addition, future studies should utilize advanced neurophysiological and molecular biology techniques to uncover the importance of lactate in maintaining brain function and preventing neurological diseases. Accordingly, this article first reviews the historical research on lactate, then summarizes the metabolic characteristics and neuronal sources of lactate, and finally explores the role and mechanisms of exercise-induced lactate in the nervous system, aiming to provide new perspectives and targets for understanding the mechanisms underlying exercise promotion of brain health.

Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.

Objective:To evaluate the application of a two-stage sequential nutritional therapy combined with functional exercise in the preoperative prehabilitation of patients with high-output intestinal fistula(HIF).Methods:A total of 164 HIF patients scheduled for definitive fistula resection in the Department of General Surgery,Eastern Theater Command General Hospital from March 2023 to March 2025 were prospectively enrolled.They were randomly assigned to a control group or an intervention group at a 1:1 ratio,with 82 patients in each group.The control group received conventional nutritional support and basic functional exercise,while the intervention group underwent a two-stage sequential nutritional therapy combined with graded functional exercise.Nutritional indicators,inflammatory markers,functional status,and postoperative recovery were compared between the two groups at 28 days before surgery,1 day before surgery,and 1,3,and 7 days after surgery.Results:On the day before surgery,the nutritional indicators in the intervention group,including albumin[(36.8±4.1)g/L],prealbumin[(213.5±42.1)mg/L],and total protein[(69.3±6.1)g/L],were all significantly higher than those in the control group[albumin(33.1±3.9)g/L,prealbumin(163.2±37.6)mg/L,total protein(63.7±5.9)g/L],with P<0.001.The energy compliance rates on the 21st day before surgery and the day before surgery in the intervention group(85.2%,92.8%)were significantly higher than those in the control group(62.5%,72.4%),with P<0.001.The 6-minute walk distance(6MWD)in the intervention group on the day before surgery and on the 7th day after surgery[(385.1±55.2)m,(346.3±48.4)m]was significantly greater than that in the control group[(315.3±60.7)m,(298.3±51.1)m],with P<0.001.On the 1st day after surgery,the inflammatory markers in the intervention group[CRP(98.7±35.2)mg/L,IL-6(45.3±12.5)pg/mL,PCT(1.2±0.5)ng/mL]were all significantly lower than those in the control group[CRP(152.4±48.6)mg/L,IL-6(89.6±25.4)pg/mL,PCT(2.8±0.9)ng/mL],with P<0.001.Additionally,the time to first ambulation after surgery[(16.8±4.2)h],time to first flatus[(52.4±14.5)h],and ICU stay duration[(3.1±1.6)d]in the intervention group were all significantly shorter than those in the control group,with P<0.001 Conclusion:The two-stage sequential nutritional therapy combined with functional exercise significantly improves the attainment of nutritional targets,suppresses systemic inflammatory response,enhances muscle reserve and exercise tolerance,and effectively shortens the postoperative recovery period in HIF patients.These findings support the use of this combined approach as a targeted and feasible model for preoperative prehabilitation,demonstrating substantial clinical application value.

Objectives: Hypoparathyroidism (HP) is a rare endocrine disorder caused by parathyroid hormone (PTH) defi ciency. The PTH is a candidate gene for familial isolated hypoparathyroidism (FIH). This study aimed to investigate the pathogenicity of two novel rare variants (RVs) ofPTH through in vitro functional study. Methods: Targeted next-generation sequencing was used to identify candidate gene mutations. Clinical data were retrospectively collected. Wild-type (WT) PTH was used as a template for site-directed mutagenesis to create mutant eukaryotic expression plasmids, which were transfected into cells. Treated with or without 4-phenylbu tyric acid (4-PBA), the levels of intact PTH (iPTH) and PTH (1-84) were measured by chemiluminescence, and protein expression was assessed using Western blotting. Results: Two patients carrying PTH mutations (c.154G > A: p.Val52Ile, c.270G > T: p.Leu90Phe) were identified.Patient 1, a 45-year-old male, presented with carpal and pedal numbness, muscle cramps, and low serum calcium (1.29 mmol/L). Patient 2, a 12-year-old female, had muscle twitches, convulsions, low calcium (1.50 mmol/L), and iPTH of 4 pg/mL. The iPTH or PTH (1-84) levels in the medium transfected with mutant Val52Ile and Leu90Phe PTH decreased by 31%–38%, and 51%–96% compared to WT (allP < 0.05), which were not rescued by 4-PBA. No significant changes in intracellular PTH expression were observed. Conclusions In this study, two novel RVs of PTH(Val52Ile and Leu90Phe) were identified that may impair hormone synthesis and secretion. Our study has broadened the mutation spectrum of the PTH and shed light on potential mechanisms underlying FIH.