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.

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.

OBJECTIVE: To evaluate the short-term clinical efficacy of external fixation and internal fixation with steel plate in the treatment of unstable distal radius fractures (AO-23C type), based on the principles of Chinese osteosynthesis (CO). METHODS: Forty-eight patients with unstable distal radius fractures between January 2022 and February 2023 were retrospectively analyzed and divided into the CO external fixation group and internal fixation group. CO external fixation group consisted of 25 patients, including 7 males and 18 females, aged from 37 to 56 years old with an average of ( 52.6±11.3) years old. Among them, there were 7 patients of traffic accidents and 18 patients of falls, resulting in a total of 25 patients of closed fractures and no open fractures, the treatment was conducted using closed reduction and CO external fixation. The internal fixation group consisted of 23 patients, comprising 8 males and 15 females, age ranged from 41 to 59 years old, with an average age of(53.3±13.7) years old. Among them, 8 patients resulted from car accidents while the remaining 15 patients were caused by falls. All 23 patients were closed fractures without any open fractures observed. The technique of open reduction and internal fixation with steel plate was employed. The perioperative data, including injury-operation time, operation duration, blood loss, and length of hospital stay, were assessed in both groups. Additionally, the QuickDASH score and visual analogue scale (VAS) were evaluated. Range of motion and grip strength assessment, imaging findings such as palmar inclination angle, ulnar declination angle, radius length, articular surface step, intra-articular space measurements were also examined along with any complications. RESULTS: The follow-up duration ranged from 0 to 24 months, with an average duration of (16.0±3.8) months. The CO external fixation exhibited significantly shorter time from injury to operation (2.4±3.3) d vs (7.4±3.7) d, shorter operation duration (56.27±15.23) min vs (74.10±5.26) min, lower blood loss (14.52±6.54) ml vs (32.32±10.03) ml, and reduced hospitalization days (14.04±3.24 )d vs (16.45±3.05) d compared to the internal fixation group (P<0.05). The QuickDASH score at 12 months post-operation was (8.21±1.64) in the CO external fixation group, while no significant difference was observed in the internal fixation group (7.04±3.64), P>0.05. There were no statistically significant differences in VAS between two groups at 6 weeks, as well as 1 and 3 months post-surgery (P>0.05). Additionally, there were no significant disparities observed in terms of range of motion and grip strength between two groups at the 2-year follow-up after the operation (P>0.05). After 12 months of surgery, the CO external fixation group exhibited a significantly smaller palmar inclination angle (17.90±2.18) ° vs (19.87±3.21) °, reduced articular surface step (0.11±0.03) mm vs (0.17±0.02) mm, and shorter radius length (8.16±1.11) mm compared to the internal fixation group (9.59±1.02) mm, P<0.05. The ulnar deviation angle and intra-articular space did not show any significant difference between two groups (P>0.05). The reduced fell within the allowable range between the CO external fixation group (23 out of 25 cases) and the internal fixation group (21 out of 23 cases) was not statistically significant (P=0.29). There was no significant difference in complications between the two groups(P>0.05). CONCLUSION Both the CO external fixation and open reduction with plate internal fixation demonstrate clinical efficacy in managing unstable distal radius fractures. The CO external fixation offers advantages in shorter injury-to-operation times, reduced intraoperative blood loss, and decreased surgical durations, while radial shortening is more effectively controlled by internal fixation.
Humans ; Male ; Female ; Middle Aged ; Radius Fractures/physiopathology* ; Adult ; Bone Plates ; Fracture Fixation, Internal/methods* ; External Fixators ; Retrospective Studies ; Fracture Fixation/methods* ; Wrist Fractures

[This corrects the article DOI: 10.1016/j.apsb.2022.05.019.].

Metabolic reprogramming is a hallmark of cancer, including lung cancer. However, the exact underlying mechanism and therapeutic potential are largely unknown. Here we report that protein arginine methyltransferase 6 (PRMT6) is highly expressed in lung cancer and is required for cell metabolism, tumorigenicity, and cisplatin response of lung cancer. PRMT6 regulated the oxidative pentose phosphate pathway (PPP) flux and glycolysis pathway in human lung cancer by increasing the activity of 6-phospho-gluconate dehydrogenase (6PGD) and α-enolase (ENO1). Furthermore, PRMT6 methylated R324 of 6PGD to enhancing its activity; while methylation at R9 and R372 of ENO1 promotes formation of active ENO1 dimers and 2-phosphoglycerate (2-PG) binding to ENO1, respectively. Lastly, targeting PRMT6 blocked the oxidative PPP flux, glycolysis pathway, and tumor growth, as well as enhanced the anti-tumor effects of cisplatin in lung cancer. Together, this study demonstrates that PRMT6 acts as a post-translational modification (PTM) regulator of glucose metabolism, which leads to the pathogenesis of lung cancer. It was proven that the PRMT6-6PGD/ENO1 regulatory axis is an important determinant of carcinogenesis and may become a promising cancer therapeutic strategy.

Objective: To evaluate the effect of ultrasound diagnosis of thyroid micro-malignant nodules and accumulate practical experience for the management of active surveillance for them, so as to avoid overtreatment. Methods: A total of 949 patients who were diagnosed with thyroid malignant nodules using ultrasonography, with the nodules being less than 1 cm in size and without regional lymph node metastasis or distant metastasis, were included. They were treated by the same surgeon of the Department of Head and Neck Surgery, Cancer Hospital, Chinese Academy of Medical Sciences from February 2014 to December 2020. 112 patients chose immediate surgery. The rest patients were asked to accept ultrasound examination every 6 months to 1 year. Follow-up endpoints: tumor size growth of 3 mm, tumor volume increase greater than 50%, lymph node metastasis or distant metastasis. Results: The median follow-up time was 19 months. 713 patients underwent surveillance for more than 6 months. Of the 713 patients, 570 (79.9%) were women, with mean age at 43.5 years old. Tumor progression was observed in 47 (6.6%) patients with a cumulative incidence of 2.7% (1 year), 7.2% (2 years) and 9.5% (3 years). In multivariate analysis, patient age [HR=0.508, 95%CI: 0.275-0.939, P=0.031], lesion number [HR=2.945, 95%CI: 1.593-5.444, P=0.001] and tumor size [HR=2.245, 95%CI: 1.202-4.192, P=0.011] at the beginning of observation were independent risk factors for tumor progression in patients with minimal thyroid malignant nodules during follow-up. During a median (range) active surveillance of 19 (6-80) months, 74 patients chose surgery during the surveillance. Among the 186 patients who underwent surgery, only 3 patients were diagnosed with fibrotic nodules in pathology, while the rest were papillary thyroid carcinoma. The ultrasound accuracy reached 98.4%(183/186). Conclusions: Ultrasonography is an effective method of diagnosing malignant thyroid nodules. Thyroid micro-malignant nodules progress slowly. As a result, it is safe to observe them instead of taking immediate surgery. Patient age, lesion number and tumor size at the beginning of observation are independent risk factors for the tumor progression of malignant nodules.
Humans ; Female ; Adult ; Male ; Thyroid Nodule/surgery* ; Carcinoma, Papillary/surgery* ; Lymphatic Metastasis ; Thyroid Neoplasms/surgery* ; Thyroidectomy/methods* ; Watchful Waiting ; Ultrasonography ; Retrospective Studies

OBJECTIVES: To evaluate the accuracy and safety of measurements of transcutaneous carbon dioxide partial pressure (TcPCO METHODS: A total of 45 very low birth weight infants were enrolled. TcPCO RESULTS: There was no significant difference in TcPCO CONCLUSIONS Lower electrode temperatures (38-41℃) can accurately measure blood carbon dioxide partial pressure in very low birth weight infants, and thus can be used to replace the electrode temperature of 42°C. Transcutaneous measurements at the lower electrode temperatures may be helpful for understanding the changing trend of blood oxygen partial pressure.
Blood Gas Monitoring, Transcutaneous ; Carbon Dioxide ; Electrodes ; Humans ; Infant ; Infant, Newborn ; Infant, Very Low Birth Weight ; Oxygen ; Partial Pressure ; Temperature

Although DNA 5-hydroxymethylcytosine (5hmC) is recognized as an important epige-netic mark in cancer, its precise role in lymph node metastasis remains elusive. In this study, we investigated how 5hmC associates with lymph node metastasis in breast cancer. Accompanying with high expression of TET1 and TET2 proteins, large numbers of genes in the metastasis-positive pri-mary tumors exhibit higher 5hmC levels than those in the metastasis-negative primary tumors. In contrast, the TET protein expression and DNA 5hmC decrease significantly within the metastatic lesions in the lymph nodes compared to those in their matched primary tumors. Through genome-wide analysis of 8 sets of primary tumors, we identified 100 high-confidence metastasis-associated 5hmC signatures, and it is found that increased levels of DNA 5hmC and gene expression of MAP7D1 associate with high risk of lymph node metastasis. Furthermore, we demonstrate that MAP7D1, regulated by TET1, promotes tumor growth and metastasis. In conclusion, the dynamic 5hmC profiles during lymph node metastasis suggest a link between DNA 5hmC and lymph node metastasis. Meanwhile, the role of MAP7D1 in breast cancer progression suggests that the metastasis-associated 5hmC signatures are potential biomarkers to predict the risk for lymph node metastasis, which may serve as diagnostic and therapeutic targets for metastatic breast cancer.

The aim of this study was to identify the anti-inflammatory markers of Zhachong shisanwei pills (ZC-13) and characterize their mechanisms. UPLC/Q-TOF-MS combined with an NF-κB dual fluorescence reporter gene system and NO content detection were utilized to identify the anti-inflammatory bioactive substances in ZC-13. Network pharmacology and bioinformatics methods were used to predict the main targets and pathways of these anti-inflammatory markers, and to verify the main anti-inflammatory pathways of costunolide. Results showed that in ZC-13, four kinds of markers related to NF-κB inhibition were identified: gallic acid, ellagic acid, liquiritin apioside, glycyrrhizic acid, and four kinds of markers related to NO release inhibition were found: gallic acid, liquiritigenin, costunolide, and dehydrocostus lactone. The above components exert anti-inflammatory activities mainly through the regulation of PDK1 (3-phosphoinositide-dependent protein kinase 1), MAPK14 (mitogen-activated protein kinase), GSK3β (glycogen synthase kinase-3β) and other anti-inflammatory-related targets, and further adjust the PI3K-AKT (phosphoinositide 3-kinase- protein kinase B), MAPK, mTOR (mammalian target of rapamycin) pathways. Among them, costunolide can inhibit AKT phosphorylation and NF-κB nuclear transfer. The above results identified the anti-inflammatory markers and possible mechanisms of ZC-13, and provide a theoretical basis for standardizing the clinical application and quality of ZC-13.