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.Clinical characteristics and short-term prognosis of acute myocardial infarction following cardiac surgery
Tingting YANG ; Yunqing SHI ; Beijian ZHANG ; Juying QIAN ; Shufu CHANG ; Junbo GE
Chinese Journal of Clinical Medicine 2026;33(3):486-492
Objective To explore the clinical characteristics and short-term prognosis of postoperative acute myocardial infarction (PAMI) after cardiac surgery. Methods A retrospective study was conducted on 45 PAMI patients who underwent coronary angiography after cardiac surgery at Zhongshan Hospital, Fudan University, from February 2015 to February 2025. General information, type of surgery, onset time and causes of PAMI, and in-hospital recovery condition were collected. Univariate logistic regression was used to analyze factors related to in-hospital survival. Results The patients’ age was (62.40±11.72) years, 31 cases (68.89%) were male, 21 cases (46.67%) had hypertension. Twenty-six patients (57.78%) underwent cardiac valve surgery, and 16 patients (35.56%) received coronary artery bypass grafting. The onset time of PAMI was 24 (0, 48) hours, with 38 cases (84.44%) developing within 48 hours after surgery. Twenty-eight patients (62.22%) presented with new lesions in coronary arteries/bypass grafts, and 20 patients (44.44%) were considered to have thrombus-induced PAMI. Nine patients died in hospital, 13 patients failed to recover and were discharged automatically, and 23 patients were discharged after recovery. Univariate logistic regression analysis showed that new lesion in coronary arteries/bypass grafts was risk factor for in-hospital survival (OR=0.235, P=0.036). Conclusions PAMI frequently occurs within 48 hours post-cardiac surgery, and thrombosis is the most common cause of PAMI. New lesions in coronary arteries/bypass grafts are closely correlated with poor short-term prognosis.
4.Construction of a biomimetic three-layered PLLA/PCL large-diameter vessel via electrospinning and ultrasonic pore-forming: Preliminary animal evaluation
Wenjun WANG ; Yang GAO ; Feng GAO ; Lei SHI ; Wei LIU ; Weiwang FAN ; Chang XU ; Hong ZHENG ; Xufeng DONG ; ZHUANG Xijing
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2026;33(07):1093-1100
Objective To fabricate a large-diameter vascular graft with a pore size gradient structure mimicking that of natural blood vessels, using poly-L-lactic acid (PLLA) and polycaprolactone (PCL) as base materials through electrospinning and ultrasonic pore-forming techniques, and to evaluate its application potential. Methods A three-layered tubular graft was fabricated from a PCL/PLLA blend (mass ratio 6 : 4) via electrospinning, followed by an ultrasonic pore-forming process to create a gradient porosity. The resulting graft (diameter: 2 cm, length: 4 cm) was implanted into the descending thoracic aorta of an experimental pig using an end-to-end anastomosis. Graft patency and anastomotic sites were monitored by computed tomography angiography (CTA) at 1 and 6 weeks post-surgery. After 2 months, the graft was explanted for systematic evaluation of vascular regeneration and repair through gross examination, histopathology (H&E and elastic fiber staining), immunohistochemistry [for ETS-related gene (ERG), Actin, and Vimentin], and scanning electron microscopy (SEM). Results Postoperative CTA confirmed excellent graft patency at both 1 and 6 weeks, with no evidence of thrombosis or anastomotic stenosis. Gross examination of the 2-month explant revealed a smooth luminal surface covered by neotissue. Histopathological analysis demonstrated that the graft successfully induced the formation of a three-layered structure resembling a native vessel wall, comprising endothelial cells, smooth muscle cells, and fibroblasts. Immunohistochemistry further verified coverage of the luminal surface by endothelial cells (ERG-positive), along with the presence of neosmooth muscle (Actin-positive) and fibroblasts (Vimentin-positive). Endothelial cells were observed adhering to the inner surface of the artificial vessel under SEM. Conclusion The biomimetic, three-layered PLLA/PCL large-diameter vascular graft, constructed via electrospinning and ultrasonic pore-forming, exhibits excellent short-term patency and biocompatibility in a large animal model. More importantly, it demonstrates a significant potential to promote host cell infiltration and achieve in situ regeneration of a three-layered vascular wall structure, providing a promising experimental basis for the development of next-generation functional vascular substitutes.
5.A study on electroencephalogram characteristics of depression in patients with aphasia based on resting state and emotional Stroop task.
Siyuan DING ; Yan ZHU ; Chang SHI ; Banghua YANG
Journal of Biomedical Engineering 2025;42(3):488-495
Post-stroke aphasia is associated with a significantly elevated risk of depression, yet the underlying mechanisms remain unclear. This study recorded 64-channel electroencephalogram data and depression scale scores from 12 aphasic patients with depression, 8 aphasic patients without depression, and 12 healthy controls during resting state and an emotional Stroop task. Spectral and microstate analyses were conducted to examine brain activity patterns across conditions. Results showed that depression scores significantly negatively explained the occurrence of microstate class C and positively explained the transition probability from microstate class A to B. Furthermore, aphasic patients with depression exhibited increased alpha-band activation in the frontal region. These findings suggest distinct neural features in aphasic patients with depression and offer new insights into the mechanisms contributing to their heightened vulnerability to depression.
Humans
;
Electroencephalography
;
Aphasia/etiology*
;
Stroop Test
;
Emotions/physiology*
;
Depression/etiology*
;
Male
;
Female
;
Middle Aged
;
Stroke/complications*
;
Brain/physiopathology*
;
Aged
;
Adult
;
Rest/physiology*
6.Application of genome tagging technology in elucidating the function of sperm-specific protein 411 (Ssp411).
Xue-Hai ZHOU ; Min-Min HUA ; Jia-Nan TANG ; Bang-Guo WU ; Xue-Mei WANG ; Chang-Gen SHI ; Yang YANG ; Jun WU ; Bin WU ; Bao-Li ZHANG ; Yi-Si SUN ; Tian-Cheng ZHANG ; Hui-Juan SHI
Asian Journal of Andrology 2025;27(1):120-128
The genome tagging project (GTP) plays a pivotal role in addressing a critical gap in the understanding of protein functions. Within this framework, we successfully generated a human influenza hemagglutinin-tagged sperm-specific protein 411 (HA-tagged Ssp411) mouse model. This model is instrumental in probing the expression and function of Ssp411. Our research revealed that Ssp411 is expressed in the round spermatids, elongating spermatids, elongated spermatids, and epididymal spermatozoa. The comprehensive examination of the distribution of Ssp411 in these germ cells offers new perspectives on its involvement in spermiogenesis. Nevertheless, rigorous further inquiry is imperative to elucidate the precise mechanistic underpinnings of these functions. Ssp411 is not detectable in metaphase II (MII) oocytes, zygotes, or 2-cell stage embryos, highlighting its intricate role in early embryonic development. These findings not only advance our understanding of the role of Ssp411 in reproductive physiology but also significantly contribute to the overarching goals of the GTP, fostering groundbreaking advancements in the fields of spermiogenesis and reproductive biology.
Animals
;
Female
;
Humans
;
Male
;
Mice
;
Spermatids/metabolism*
;
Spermatogenesis/physiology*
;
Spermatozoa/metabolism*
;
Thioredoxins/genetics*
7.Clinical Characteristics and Prognostic Analysis of Newly Diagnosed Acute Myeloid Leukemia Patients with NRAS and KRAS Gene Mutations.
Zhang-Yu YU ; Bo CAI ; Yi WANG ; Yang-Yang LEI ; Bing-Xia LI ; Yu-Fang LI ; Yan-Ping SHI ; Jia-Xin CHEN ; Shu-Hong LIU ; Chang-Lin YU ; Mei GUO
Journal of Experimental Hematology 2025;33(3):682-690
OBJECTIVE:
To retrospectively analyze the clinical characteristics, co-mutated genes in newly diagnosed acute myeloid leukemia (AML) patients with NRAS and KRAS gene mutations, and the impact of NRAS and KRAS mutations on prognosis.
METHODS:
The clinical data and next-generation sequencing results of 80 newly diagnosed AML patients treated at our hospital from December 2018 to December 2023 were collected. The clinical characteristics, co-mutated genes of NRAS and KRAS , and the impact of NRAS and KRAS mutations on prognosis in newly diagnosed AML patients were analyzed.
RESULTS:
Among 80 newly diagnosed AML patients, NRAS mutations were detected in 20 cases(25.0%), and KRAS mutations were detected in 9 cases(11.3%). NRAS mutations predominantly occurred at codons 12 and 13 of exon 2, as well as codon 61 of exon 3, while KRAS mutations were most commonly occurred at codons 12 and 13 of exon 2, all of which were missense mutations. There were no statistically significant differences observed in terms of age, sex, white blood cell count(WBC), hemoglobin(Hb), platelet count(PLT), bone marrow blasts, first induction chemotherapy regimen, CR1/CRi1 rates, chromosome karyotype, 2022 ELN risk classification and allogeneic hematopoietic stem cell transplantation(allo-HSCT) among the NRAS mutation group, KRAS mutation group and NRAS/KRAS wild-type group (P >0.05). KRAS mutations were significantly correlated with PTPN11 mutations (r =0.344), whereas no genes significantly associated with NRAS mutations were found. Survival analysis showed that compared to the NRAS/KRAS wild-type group, patients with NRAS mutation had a relatively higher 5-year overall survival (OS) rate and relapse-free survival (RFS) rate, though the differences were not statistically significant (P =0.097, P =0.249). Compared to the NRAS/KRAS wild-type group, patients with KRAS mutation had a lower 5-year OS rate and RFS rate, with no significant differences observed (P =0.275, P =0.442). There was no significant difference in the 5-year RFS rate between the KRAS mutation group and NRAS mutation group (P =0.157), but the 5-year OS rate of patients with KRAS mutation was significantly lower than that of patients with NRAS mutation (P =0.037).
CONCLUSION
In newly diagnosed AML patients, KRAS mutation was significantly correlated with PTPN11 mutation. Compared to patients with NRAS/KRAS wild-type, those with NRAS mutation showed a more favorable prognosis, while patients with KRAS mutation showed a poorer prognosis; however, these differences did not reach statistical significance. Notably, the prognosis of AML patients with KRAS mutation was significantly inferior compared to those with NRAS mutation.
Humans
;
Leukemia, Myeloid, Acute/diagnosis*
;
Mutation
;
Prognosis
;
Proto-Oncogene Proteins p21(ras)/genetics*
;
GTP Phosphohydrolases/genetics*
;
Retrospective Studies
;
Membrane Proteins/genetics*
;
Female
;
Male
;
Middle Aged
;
Adult
;
Aged
8.Proton beam range verification algorithm for pixelated prompt gamma-ray imaging detector
Liwang YANG ; Haifeng OU ; Jinlong WANG ; Xiaoguang WU ; Ziyang HE ; Jian'an ZOU ; Yun ZHENG ; Congbo LI ; Shaoxiong GUAN ; Jing SHI ; Jinze LI ; Yunqiu LI ; Rui HONG ; Hao'en CHANG ; Mengting WANG ; Kaijie WEI
Chinese Journal of Medical Physics 2025;42(3):281-287
In proton therapy,prompt gamma-ray imaging is considered as one of the most promising methods for assessing proton beam range.Prompt gamma-ray imaging detector evaluates the proton beam range based on the prompt gamma-ray distribution obtained by the prompt gamma-ray imaging system,which enables high-precision measurement of the proton beam range.Herein a proton beam range verification algorithm is designed for the newly developed prototype of the range verification detector(pixelated prompt gamma-ray imaging detector),which verifies the range estimation accuracy of the prototype for different phantoms and different energies of homogeneous media through Monte Carlo simulation.The results show that the accuracy of the proton beam range verification algorithm is within 0.5 mm of the safety margin error of the Bragg peak,and the measurement accuracy is significantly improved with the increase of the number of protons,indicating that the prototype algorithm is feasible for proton beam range verification.
9.Autonomous drug delivery and scar microenvironment remodeling using micromotor-driven microneedles for hypertrophic scars therapy.
Ting WEN ; Yanping FU ; Xiangting YI ; Ying SUN ; Wanchen ZHAO ; Chaonan SHI ; Ziyao CHANG ; Beibei YANG ; Shuling LI ; Chao LU ; Tingting PENG ; Chuanbin WU ; Xin PAN ; Guilan QUAN
Acta Pharmaceutica Sinica B 2025;15(7):3738-3755
Hypertrophic scar is a fibrous hyperplastic disorder that arises from skin injuries. The current therapeutic modalities are constrained by the dense and rigid scar tissue which impedes effective drug delivery. Additionally, insufficient autophagic activity in fibroblasts hinders their apoptosis, leading to excessive matrix deposition. Here, we developed an active microneedle (MN) system to overcome these challenges by integrating micromotor-driven drug delivery with autophagy regulation to remodel the scar microenvironment. Specifically, sodium bicarbonate and citric acid were introduced into the MNs as a built-in engine to generate CO2 bubbles, thereby enabling enhanced lateral and vertical drug diffusion into dense scar tissue. The system concurrently encapsulated curcumin (Cur), an autophagy activator, and triamcinolone acetonide (TA), synergistically inducing fibroblast apoptosis by upregulating autophagic activity. In vitro studies demonstrated that active MNs achieved efficient drug penetration within isolated scar tissue. The rabbit hypertrophic scar model revealed that TA-Cur MNs significantly reduced the scar elevation index, suppressed collagen I and transforming growth factor-β1 (TGF-β1) expression, and elevated LC3 protein levels. These findings highlight the potential of the active MN system as an efficacious platform for autonomous augmented drug delivery and autophagy-targeted therapy in fibrotic disorder treatments.
10.Relationship between treatment time node of ST-segment elevation myocardial infarction and reperfusion microcirculation dysfunction and prognosis based on the establishment of chest pain center system
Fei FU ; Li-xia YANG ; Jun FAN ; Chang-zheng CHEN ; Yan-kun SHI
Chinese Journal of Interventional Cardiology 2025;33(7):376-382
Objective To investigate the relationship between ST-segment elevation myocardial infarction(STEMI)treatment time nodes and coronary microcirculation dysfunction(CMD)after primary percutaneous coronary intervention(PCI)and its prognosis,providing evidence for early identification of high-risk patients,further optimization of treatment system,shortening treatment time and improving prognosis.Methods This study selected 150 STEMI patients who received primary PCI at the 920th Hospital of the Joint Logistic Support Force of the People's Liberation Army of China from March 2023 to September 2023 as the CMD group after PCI(89 cases),with a microcirculation resistance index(caIMR)of≥40 U based on coronary angiography.caIMR<40 U was classified as the non-CMD group(61 cases).The clinical data,various examination indicators and imaging data of the two groups of patients were collected,and the occurrence of major adverse cardiovascular events(MACE)within half a year after direct PCI of the patients was followed up.The correlation between the two variables was analyzed using Spearman.Multivariate Logistic regression was used to analyze the relationship between each treatment time point and the occurrence of CMD after direct PCI.Using receiver operating characteristic(ROC)curve analysis to predict the occurrence of CMD after direct PCI.The survival curves between the two groups were plotted using the Kaplan-Meier method.Results The levels of symptom onset-to-balloon(S-to-B),symptom onset-to-first medical contact(S-to-FMC),first medical contact-to-balloon(FMC-to-B),symptom onset-to-door(S-to-D)and first medical contact-to-door(FMC-to-D)in the CMD group were significantly higher than those in the non-CMD group(all P<0.05).Correlation analysis showed that S-to-D,S-to-FMC,the time from FMC-to-B,and the time from FMC-to-D were all positively correlated with the time from S-to-B(r=0.996,P<0.001;r=0.937,P<0.001;r=0.431,P<0.001;r=0.441,P<0.001).Multivariate Logistic regression analysis indicated that the duration of S-to-D(OR 2.165,95%CI 1.655-2.830,P<0.001)was a significant influencing factor for CMD.Moreover,S-to-D has a relatively high predictive value for the occurrence of CMD after direct PCI.The area under the ROC curve is 0.898(95%CI 0.850-0.946,P<0.001),the optimal cut-off value is 231 min,the sensitivity is 82.0%,and the specificity is 88.5%.Kaplan-Meier curve analysis showed that the cumulative survival rate of MACE outcomes in the CMD group was significantly lower than that in the non-CMD group(Log-rank P=0.009).Conclusions Shortening the S-to-D time can reduce the occurrence of CMD after PCI,thereby reducing the incidence of MACE and improving prognosis.

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