Recent studies have shown that shorter periods of ejaculatory abstinence may enhance certain sperm parameters, but the molecular mechanisms underlying these improvements are still unclear. This study explored whether reduced abstinence periods could improve semen quality, particularly for use in assisted reproductive technologies (ART). We analyzed semen samples from men with normal sperm counts ( n = 101) and those with low sperm motility or concentration ( n = 53) after 3-7 days of abstinence and then after 1-3 h of abstinence, obtained from the Reproductive & Genetic Hospital of CITIC-Xiangya (Changsha, China). Physiological and biochemical sperm parameters were evaluated, and the dynamics of transfer RNA (tRNA)-derived fragments (tRFs) were analyzed using deep RNA sequencing in five consecutive samples from men with normal sperm counts. Our results revealed significant improvement in sperm motility and a decrease in the DNA fragmentation index after the 1- to 3-h abstinence period. Additionally, we identified 245 differentially expressed tRFs, and the mitogen-activated protein kinase (MAPK) signaling pathway was the most enriched. Further investigations showed significant changes in tRF-Lys-TTT and its target gene mitogen-activated protein kinase kinase 2 ( MAP2K2 ), which indicates a role of tRFs in improving sperm function. These findings provide new insights into how shorter abstinence periods influence sperm quality and suggest that tRFs may serve as biomarkers for male fertility. This research highlights the potential for optimizing ART protocols and improving reproductive outcomes through molecular approaches that target sperm function.
Male ; Humans ; Spermatozoa/metabolism* ; RNA, Transfer/genetics* ; Sperm Motility/genetics* ; Adult ; Semen Analysis ; Sexual Abstinence/physiology* ; Sperm Count ; DNA Fragmentation

The aryl hydrocarbon receptor (AhR) plays a crucial role in regulating many physiological processes. Activating the AhR-CYP1A1 axis has emerged as a novel therapeutic strategy against various inflammatory diseases. Here, a practical in situ cell-based fluorometric assay was constructed to screen AhR-CYP1A1 axis modulators, via functional sensing of CYP1A1 activities in live cells. Firstly, a cell-permeable, isoform-specific enzyme-activable fluorogenic substrate for CYP1A1 was rationally constructed for in-situ visualizing the dynamic changes of CYP1A1 function in living systems, which was subsequently used for discovering the efficacious modulators of the AhR-CYP1A1 axis. Following screening of a compound library, LAC-7 was identified as an efficacious activator of the AhR-CYP1A1 axis, which dose-dependently up-regulated the expression levels of both CYP1A1 and AhR in multiple cell lines. LAC-7 also suppressed macrophage M1 polarization and reduced the levels of inflammatory factors in LPS-induced bone marrow-derived macrophages. Animal tests showed that LAC-7 could significantly mitigate DSS-induced ulcerative colitis and LPS-induced acute lung injury in mice, and markedly reduced the levels of multiple inflammatory factors. Collectively, an optimized fluorometric cell-based assay was devised for in situ functional imaging of CYP1A1 activities in living systems, which strongly facilitated the discovery of efficacious modulators of the AhR-CYP1A1 axis as novel anti-inflammatory agents.

Despite therapy with potent antiviral agents, chronic hepatitis B (CHB) patients remain at high risk of hepatocellular carcinoma (HCC). While metabolites have been rediscovered as active drivers of biological processes including carcinogenesis, the specific metabolites modulating HCC risk in CHB patients are largely unknown. Here, we demonstrate that baseline plasma from CHB patients who later developed HCC during follow-up exhibits growth-promoting properties in a case-control design nested within a large-scale, prospective cohort. Metabolomics analysis reveals a reduction in long-chain acylcarnitines (LCACs) in the baseline plasma of patients with HCC development. LCACs preferentially inhibit the proliferation of HCC cells in vitro at a physiological concentration and prevent the occurrence of HCC in vivo without hepatorenal toxicity. Uptake and metabolism of circulating LCACs increase the intracellular level of acetyl coenzyme A, which upregulates histone H3 Lys14 acetylation at the promoter region of KLF6 gene and thereby activates KLF6/p21 pathway. Indeed, blocking LCAC metabolism attenuates the difference in KLF6/p21 expression induced by baseline plasma of HCC/non-HCC patients. The deficiency of circulating LCACs represents a driver of HCC in CHB patients with viral control. These insights provide a promising direction for developing therapeutic strategies to reduce HCC risk further in the antiviral era.

Notum, a negative feedback regulator of the Wnt signaling, has emerged as a promising target for treating glucocorticoid-induced osteoporosis (GIOP). This study showcases an efficient strategy for discovering the anti-Notum constituents from herbal medicines (HMs) as novel anti-GIOP agents. Firstly, a rapid-responding near-infrared fluorogenic substrate for Notum was rationally engineered for high-throughput identifying the anti-Notum HMs. The results showed that Bu-Gu-Zhi (BGZ), a known anti-osteoporosis herb, potently inhibited Notum in a competitive-inhibition manner. To uncover the key anti-Notum constituents in BGZ, an efficient strategy was adapted via integrating biochemical, phytochemical, computational, and pharmacological assays. Among all identified BGZ constituents, three furanocoumarins were validated as strong Notum inhibitors, while 5-methoxypsoralen (5-MP) showed the most potent anti-Notum activity and favorable safety profiles. Mechanistically, 5-MP acted as a competitive inhibitor of Notum via creating strong hydrophobic interactions with Trp128 and Phe268 in the catalytic cavity of Notum. Cellular assays showed that 5-MP remarkably promoted osteoblast differentiation and activated Wnt signaling in dexamethasone (DXMS)-challenged MC3T3-E1 osteoblasts. In dexamethasone-induced osteoporotic mice, 5-MP strongly elevated bone mineral density (BMD) and improved cancellous and cortical bone thickness. Collectively, this study constructs a high-efficient platform for discovering key anti-Notum constituents from HMs, while 5-MP emerges as a promising anti-GIOP agent.

Human carboxylesterase 2A (hCES2A) plays pivotal roles in prodrug activation and hydrolytic metabolism of ester-bearing chemicals. Targeted inhibition of intestinal hCES2A represents a feasible strategy to mitigate irinotecan-triggered gut toxicity (ITGT), but the orally active, selective, and efficacious hCES2A inhibitors are rarely reported. Here, a novel drug-like hCES2A inhibitor was developed via three rounds of structure-based drug design (SBDD) and structural optimization. Initially, donepezil was identified as a moderate hCES2A inhibitor from 2000 US Food and Drug Administration (FDA)-approved drugs. Following two rounds of SBDD and structural optimization, a donepezil derivative (B7) was identified as a strong reversible hCES2A inhibitor. Subsequently, nine B7 carbamates were rationally designed, synthesized and biologically assayed. Among all synthesized carbamates, C3 showed the most potent time-dependent inhibition on hCES2A (IC₅₀ = 0.56 nmol/L), excellent specificity and favorable drug-like properties. C3 could covalently modify the catalytic serine of hCES2A with high selectivity, while this agent also showed favorable safety profiles, high intestinal exposure, and impressive effects for ameliorating ITGT in both human intestinal organoids and tumor-bearing mice. Collectively, this study showcases a rational strategy for developing drug-like and serine-targeting covalent inhibitors against target serine hydrolase(s), while C3 emerges as a promising orally active drug candidate for ameliorating ITGT.

Hypoxic injury (HI) in the prenatal period often causes neonatal neurological disabilities. Due to the difficulty in obtaining clinical samples, the molecular and cellular mechanisms remain unclear. Here we use vascularized cerebral organoids to investigate the hypoxic injury phenotype and explore the intercellular interactions between vascular and neural tissues under hypoxic conditions. Our results indicate that fused vascularized cerebral organoids exhibit broader hypoxic responses and larger decreases in panels of neural development-related genes when exposed to low oxygen levels compared to single cerebral organoids. Interestingly, vessels also exhibit neural protective effects on T-box brain protein 2⁺ intermediate progenitors (IPs), which are markedly lost in HI cerebral organoids. Furthermore, we identify the role of bone morphogenic protein signaling in protecting IPs. Thus, this study has established an in vitro organoid system that can be used to study the contribution of vessels to brain injury under hypoxic conditions and provides a strategy for the identification of intervention targets.
Organoids/pathology* ; Animals ; Mice ; Hypoxia, Brain/metabolism* ; Brain/blood supply* ; Neurons/metabolism*

Objective:To investigate the effects of apical periodontitis of mandibular primary molars on the development of mandibu-lar permanent premolars in children in Guangzhou.Methods:335 children aged 4-9 years with apical periodontitis of mandibular pri-molar at one side and normal healthy homologous tooth at another side were included and divided into 2 groups:Group A(n=200)in-cluded the first mandibular premolars and group B(n=135)included the second mandibular premolars.Subgroup A1 and B1 were the apical periodontitis groups,subgroup A2 and B2 were the normal healthy groups.The degree of root destruction of primary teeth,the degree of destruction and development of the dental follicle of permanent teeth,the mesial and distal direction changes,and the eruption height were observed and measured on the panoramic raidiographs,data were statistically analyzed.Results:In the 7-year-old children of A1 and the 6-year-old of B1 groups,the development degree of successor permanent teeth was lower than that of group A2 and group B2 of the same age children respectively(P＜0.05).In the 6-7-year-old children of group A1,the permanent teeth development of boys was slower than that of the girls(P＜0.05).There was no gender difference in dental follicle destruction and malposition of the perma-nent teeth in both A1 and B1 groups(P＞0.05).The proportion of malposition of the successor permanent teeth in group A1 increased with the primary teeth damage degree increace(P＜0.05),while the proportion of malposition of the successor permanent teeth in group B1 showed no significant difference(P＞0.05).Positive correlation between the damage degree of primary teeth and dental follicle of per-manent teeth was observed(rA1=0.41,rB1=0.21,P＜0.05).In boys aged 7-8 years,the succesor permanent teeth eruption in group A1 was higher than that in group A2(P＜0.05),and there was no significant difference between group B1 and group B2(P＞0.05).Conclusion:In the later stages of root stabilization of primary molars,periapical inflammation of primary teeth may cause developmen-tal delay of the succesor permanent teeth,and the delay degree is higher in boys than in girls.With the deterioration of the periapical tissue of primary teeth,the destruction of the dental follicle of permanent teeth may deepen,and the mandibular first premolar is more likely to have abnormal eruption.

Objective To explore the differences in coronary-based and lesion-based fat attenuation index(FAI)in patients with coronary artery disease(CAD)across different risk stratifications,and to compare the diagnostic efficiency of coronary-based and lesion-based FAI in stable CAD patients with myocardial ischemia.Methods The patients with CAD,who underwent preoperative coronary CT angiography(CCTA)and invasive coronary angiography(ICA)with coronary fractional flow reserve(FFR)measurement between Apr 2019 and Oct 2022 in Zhongshan Hospital,Fudan University,were retrospectively collected.There were 57 cases of acute coronary syndrome(ACS)patients and 206 cases of stable CAD patients included following inclusion criteria.The coronary-based and lesion-based FAI were measured,and the differences in these indices were recorded and analyzed among ACS patients,ischemic and non-ischemic groups of stable CAD patients(FFR=0.8 as the threshold).ROC curves were utilized to assess the diagnostic efficiency of coronary-based and lesion-based FAI for myocardial ischemia in stable CAD patients.Results The coronary-based FAI and lesion-based FAI in ACS patients were significantly higher than those in stable CAD patients[coronary-based FAI:(-72.40±6.83)HU vs.(-76.82±9.01)HU,P<0.001;lesion-based FAI:(-65.65±4.79)HU vs.(-77.48±8.64)HU,P<0.001].Among stable CAD patients,the lesion-based FAI in the ischemic group was significantly higher than that in the non-ischemic group[(-69.28±5.65)HU vs.(-80.10±7.75)HU,P<0.001].The diagnostic efficiency of lesion-based FAI for predicting myocardial ischemia in stable CAD patients was superior to coronary-based FAI(AUC:0.892 vs.0.525,Z=9.803,P<0.001).Conclusion Coronary-based and lesion-based FAI tended to be higher in ACS patients than in stable CAD patients,suggesting a potential for stratifying CAD patients with different risks.Lesion-based FAI showed some promise in evaluating myocardial ischemia among stable CAD patients.

Since the emergence of thoracoscopic surgery in the 1990s,innovations in surgical approaches for thoracic surgery have never ceased.During this process,the subxiphoid approach has gradually stood out due to its distinctive perspective advantages,superior cosmetic outcomes,and significant reduction in postoperative pain.After entering the 21st century,multi-center research teams,both domestically and internationally,have continuously expanded the application scope of the subxiphoid approach,transforming it from an early exploratory technique into one of the conventional surgical methods in thoracic surgery.Currently,the subxiphoid approach has demonstrated its unique value in clinical settings,including mediastinal tumor resection,lung surgery,chest wall surgery and diverse biopsies.This article aims to provide a systematical elaboration on the latest progress in the application of the subxiphoid approach and explore its future development trends.