Liver fibrosis is a chronic liver injury resulting from factors like viral hepatitis, autoimmune hepatitis, non-alcoholic steatohepatitis, fatty liver disease, and cholestatic liver disease. Liver transplantation is currently the gold standard for treating severe liver diseases. However, it is limited by a shortage of donor organs and the necessity for lifelong immunosuppressive therapy. Mesenchymal stem cells (MSCs) can differentiate into various liver cells and enhance liver function when transplanted into patients due to their differentiation and proliferation capabilities. Therefore, it can be used as an alternative therapy for treating liver diseases, especially for liver cirrhosis, liver failure, and liver transplant complications. However, due to the potential tumorigenic effects of MSCs, researchers are exploring a new approach to treating liver fibrosis using extracellular vesicles (exosomes) secreted by stem cells. Many studies show that exosomes released by stem cells can promote liver injury repair through various pathways, contributing to the treatment of liver fibrosis. In this review, we focus on the molecular mechanisms by which stem cell exosomes affect liver fibrosis through different pathways and their potential therapeutic targets. Additionally, we discuss the advantages of exosome therapy over stem cell therapy and the possible future directions of exosome research, including the prospects for clinical applications and the challenges to be overcome.

Liver fibrosis is a chronic liver injury resulting from factors like viral hepatitis, autoimmune hepatitis, non-alcoholic steatohepatitis, fatty liver disease, and cholestatic liver disease. Liver transplantation is currently the gold standard for treating severe liver diseases. However, it is limited by a shortage of donor organs and the necessity for lifelong immunosuppressive therapy. Mesenchymal stem cells (MSCs) can differentiate into various liver cells and enhance liver function when transplanted into patients due to their differentiation and proliferation capabilities. Therefore, it can be used as an alternative therapy for treating liver diseases, especially for liver cirrhosis, liver failure, and liver transplant complications. However, due to the potential tumorigenic effects of MSCs, researchers are exploring a new approach to treating liver fibrosis using extracellular vesicles (exosomes) secreted by stem cells. Many studies show that exosomes released by stem cells can promote liver injury repair through various pathways, contributing to the treatment of liver fibrosis. In this review, we focus on the molecular mechanisms by which stem cell exosomes affect liver fibrosis through different pathways and their potential therapeutic targets. Additionally, we discuss the advantages of exosome therapy over stem cell therapy and the possible future directions of exosome research, including the prospects for clinical applications and the challenges to be overcome.

The integration of science and education is not only an important strategy for promoting social progress and technological development,but also a modern form of higher education aiming at cultivating innovative talents.Conducting scientific research training for undergraduate medical students is one of the important ways to cultivate their innovative abilities and comprehensive qualities.Our team proposed a"teaching,science,and ideology trinity"teaching model to comprehensively cultivate students' scientific research comprehensive abilities under the value orientation of ideological and political education by or-ganically integrating molecular biology experimental teaching with the scientific research training of under-graduate medical students.In this teaching activity,taking the experiment of gene polymorphism as an example,our team selected students with research potential from the whole grade and divided them into 4 project groups that were instructed by 4 teachers.The students were trained in the whole process of scien-tific research,including topic selection,project writing,experimental designing,application for research ethics,and project summary.Our team has always adhered to student-contentedness of educational con-cepts to stimulate students' intrinsic motivation throughout the teaching process.Students are the design-ers and implementers of the project,and teachers are only guides and promoters of learning.After this training,students not only became familiar with the writing and implementation of scientific research pro-jects,but also improved their literature reading,experimental designing,experimental skills,and prob-lem-solving abilities.More importantly,this teaching activity also cultivated students' awareness of re-search ethics and academic moral standards.

Objective To investigate the application effect of cold snare endoscopic mucosal resection(CS-EMR)in the treatment of 6 to 9 mm colorectal small polyps.Methods A total of 82 patients with small colonic polyps in our hospital from March 2022 to August 2023 were collected and divided into the observation group(45 cases received CS-EMR)and the control group[37 cases received hot snare endoscopic mucosal resection(HS-EMR)]according to different surgical methods.The clinical efficacy,polyp resection status,complete polyp resection rate,perioperative indicators and occurrence of complications were compared between the two groups.Results Follow-up for 1 month after operation,the effective rate of treatment in the observation group was higher than that in the control group(P<0.05).There was no statistically significant difference in the polyp resection status or perioperative indicators between the two groups(P>0.05).There was no statistically significant difference in the complete polyp resection rates of patients with different pathological types or total complete resection rate between the two groups(P>0.05).The incidence of delayed bleeding and endoscopic hemostasis rate in the observation group were lower than those in the control group(P<0.05).Conclusion The complete resection rate of 6～9 mm colorectal polyps through CS-EMR was comparable to that of HS-EMR,and CS-EMR has a better efficacy and lower risk of perioperative bleeding,along with higher safety.

Objective:To investigate the biological role and molecular mechanism of checkpoint kinase 1 (CHK1) in delaying cardiac aging in mice.Methods:In vitro, a senescence model of H9C2 cells (a cardiomyocyte line) was induced using H 2O 2. A control group (without H 2O 2 treatment) and three H 2O 2-treated groups (at concentrations of 10, 30, and 50 μmol/L) were set up. The CCK-8 assay was used to evaluate the proliferative activity of cells in each group; Western blot analysis was employed to detect the expression level of CHK1; and quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to determine the messenger RNA (mRNA) expression levels of P16 and interleukin-1β (IL-1β). In vivo, C57BL/6 wild-type mice aged 2 months ( n=15) and 24 months ( n=40), as well as myocardial-specific CHK1-overexpressing (CHK1-TG) mice aged 2 months ( n=15) and 24 months ( n=40), were selected. The mice were divided into four groups based on age and genotype: 2-month-old wild-type (WT-2M), 24-month-old wild-type (WT-24M), 2-month-old CHK1-TG (CHK1-TG-2M), and 24-month-old CHK1-TG (CHK1-TG-24M). Echocardiography was used to evaluate cardiac function of mice in the WT-24M and CHK1-TG-24M groups. Western blot analysis was conducted to measure the protein expression levels of CHK1, total Ras-related protein 1 (Rap1), NADPH oxidase 4 (Nox4), and Rap1-guanosine triphosphate (Rap1-GTP, the active form of Rap1) in the cardiac tissue of mice in each group. qRT-PCR was used to detect the messenger RNA (mRNA) expression levels of CHK1, collagen type Ⅰ (Coll1), matrix metalloproteinase-2 (Mmp2), alpha-smooth muscle actin (α-SMA), P53, P21, P16, thioredoxin 1 (Trx1), thioredoxin reductase (TrxR), glutathione recluctase (GR), Rap1, and Nox4. Immunofluorescence staining was employed to determine the protein expression levels of P53, P21, and P16, as well as the proportion of histone H2AX phosphorylation-positive cells. Dihydroethidium (DHE) staining was used to detect the relative intensity of DHE. Wheat germ agglutinin staining, HE staining, Masson staining and Sirius red staining were applied to measure the cross-sectional area of cardiomyocytes, cardiac morphology, and myocardial fibrosis area. Mice in the WT-24M and CHK1-TG-24M groups were intraperitoneally injected with the Rap1 activity inhibitor GGTI298 (25 μmol/kg). After injection, the oxidative stress damage in the cardiac tissue of the mice was detected, along with the mRNA expression levels of fibrosis-related indicators (Coll1, Mmp2, and α-SMA) and cell cycle inhibitory proteins (P16, P21, and P53). Results:A concentration of 30 μmol/L was determined as the optimal concentration for establishing an H 2O 2-induced senescence model of myocardial cells in vitro. The expression level of CHK1 in H9C2 cells of the 30 μmol/L H 2O 2 group was lower than that in the control group ( P<0.05). Echocardiographic examination showed that the left ventricular ejection fraction ((61.08±1.13)% vs. (52.55±2.02)%) and fractional shortening ((31.80±1.27)% vs. (25.18±1.59)%) of mice in the CHK1-TG-24M group were higher than those in the WT-24M group (both P<0.05). qRT-PCR and Western blot analysis revealed that, compared with the WT-24M group, mice in CHK1-TG-24M group had higher expression levels of CHK1 and its mRNA, lower expression levels of Nox4 and its mRNA, and higher expression level of Rap1-guanosine triphosphate (Rap1-GTP) (all P<0.05). However, there were no statistically significant differences in the total expression level of Rap1 and its mRNA between the two groups (both P>0.05). In addition, the mRNA expression levels of Coll1, Mmp2, and α-SMA in myocardial tissue of mice in the CHK1-TG-24M group were lower than those in the WT-24M group (all P<0.05). Immunofluorescence staining results showed that the expression levels of P53, P21, and P16 proteins, as well as the proportion of phosphorylated histone H2AX-positive cells in myocardial tissue of mice in the WT-24M group were higher than those in the CHK1-TG-24M group (all P<0.05). qRT-PCR further confirmed that the mRNA expression levels of the above-mentioned proteins in cardiac tissue of mice in the WT-24M group were higher than those in the CHK1-TG-24M group (all P<0.05). DHE staining results indicated that the relative intensity of DHE in cardiac tissue of mice in the CHK1-TG-24M group was lower than that in the WT-24M group ( P<0.05). Meanwhile, the left ventricular internal diameter, cross-sectional area of cardiomyocytes, and myocardial fibrosis area of mice in the CHK1-TG-24M group were all smaller than those in the WT-24M group (all P<0.05). Furthermore, the degree of DNA damage in cardiac tissue as well as the mRNA levels of fibrosis-related indicators (Coll1, Mmp2, and α-SMA) and cell cycle inhibitory proteins (P53, P21, P16) in mice of the WT-24M+GGTI298 group were higher than those in the WT-24M group and the CHK1-TG-24M+GGTI298 group (all P<0.05). Conclusion:CHK1 alleviates oxidative stress-induced damage in mouse cardiomyocytes by activating the Rap1/Nox4 signaling pathway, thereby delaying cardiac aging in mice.

The integration of science and education is not only an important strategy for promoting social progress and technological development,but also a modern form of higher education aiming at cultivating innovative talents.Conducting scientific research training for undergraduate medical students is one of the important ways to cultivate their innovative abilities and comprehensive qualities.Our team proposed a"teaching,science,and ideology trinity"teaching model to comprehensively cultivate students' scientific research comprehensive abilities under the value orientation of ideological and political education by or-ganically integrating molecular biology experimental teaching with the scientific research training of under-graduate medical students.In this teaching activity,taking the experiment of gene polymorphism as an example,our team selected students with research potential from the whole grade and divided them into 4 project groups that were instructed by 4 teachers.The students were trained in the whole process of scien-tific research,including topic selection,project writing,experimental designing,application for research ethics,and project summary.Our team has always adhered to student-contentedness of educational con-cepts to stimulate students' intrinsic motivation throughout the teaching process.Students are the design-ers and implementers of the project,and teachers are only guides and promoters of learning.After this training,students not only became familiar with the writing and implementation of scientific research pro-jects,but also improved their literature reading,experimental designing,experimental skills,and prob-lem-solving abilities.More importantly,this teaching activity also cultivated students' awareness of re-search ethics and academic moral standards.

To investigate the transcriptionally regulatory mechanism of the senp8 promoter in yellow cat-fish(Pelteobagrus fulvidraco);this study used P.fulvidraco as the research subject.Dual-luciferase re-porter assay and electrophoretic mobility shift assay were employed to analyze the functional activity of the promoter;coupled with in vivo experiments.The results indicated that the 2 045 bp senp8 promoter se-quence contained key transcription factor binding sites such as SP1;TATA-Box;CCAAT-Box;SREBP1;PPARα;and PPARγ.The binding sites of SREBP1(-901/-910 bp);PPARα(-1 291/-1 308 bp);and PPARγ(-1 292/-1 306 bp)in the senp8 promoter positively regulate its activity;and oleic acid or palmitic acid promote this binding.Furthermore;high-fat feeding promoted the expression of the senp8 gene and its protein in the liver of P.fulvidraco;oleic acid or palmitic acid treatment significantly en-hanced the activity of the senp8 promoter;and this enhancement could be achieved through the regulatory effects of SREBP1;PPARα;and PPARγ response elements.Additionally;high-fat feeding influenced the mRNA and protein expression levels of genes related to deSUMOylation modification in the liver of P.fulvidraco.This study provides new insights into the relationship between deSUMOylation modification and the regulation of lipid metabolism in the vertebrates.

Objective:To investigate the association of the interaction and combined effect of renal function and body mass index (BMI) with the risk for all-cause death in patients with type 2 diabetes mellitus (T2DM) in communities of Jiangsu Province.Methods:The study subjects were from the Comprehensive Research Project of Diabetes Prevention and Control conducted in Jiangsu from December 2013 to January 2014, and follow up was conducted for them until September 30, 2023. A total of 20 025 subjects were included in the study. Cox proportional hazards regression model was used to analyze the association of renal function with risk for death in T2DM patients, and the association of interaction between renal function and BMI and their combined effect with all-cause death risk in T2DM patients.Results:In the follow up for 198 370 person-years, a total of 4 459 deaths were recorded. Cox proportional hazards regression model analysis showed that renal dysfunction was associated with 71% risk of all-cause mortality in all T2DM patients [hazard ratio ( HR) =1.71, 95% CI: 1.59-1.84], as well as in all BMI subgroups. Likelihood ratio test indicated an interaction between renal function and BMI (interaction for P=0.030). Compared with patients with normal renal function and normal BMI, those with normal renal function and over weight or obesity had a lower risk of all-cause mortality, and those with renal dysfunction and low weight had the highest risk for death ( HR=2.78, 95% CI: 1.87-4.14). Conclusions:There is association of interaction between renal function and BMI with all-cause mortality in T2DM patients. T2DM patients with renal dysfunction and low body weight had significant higher risk for death.

ObjectiveRepetitive transcranial magnetic stimulation (rTMS), a non-invasive brain stimulation technique, offers a non-pharmacological therapeutic option for the management of Alzheimer’s disease (AD). Studies have demonstrated that ferroptosis plays a pivotal role in the pathological onset and progression of AD, and the inhibition of neuronal ferroptosis can significantly ameliorate cognitive impairments associated with AD. The imbalance of calcium ion (Ca²⁺) homeostasis is intimately associated with the pathology of AD and serves as a catalyst for the induction of ferroptosis through various pathways. This study is designed to investigate whether rTMS can ameliorate AD by inhibiting neuronal ferroptosis or maintaining calcium homeostasis, ultimately establishing a theoretical and experimental framework for the utilization of rTMS in AD treatment. MethodsAPP/PS1 AD mice were subjected to both 0.5 Hz low-frequency and 20 Hz high-frequency rTMS treatments, and the efficacy of these treatments was evaluated using novel object recognition and Morris water maze tests. ELISA was employed to quantify the levels of glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD), Fe²⁺ within the hippocampi of mice from each group. HT-22 cells were induced to undergo ferroptosis via Erastin treatment, and subsequent to high- and low-frequency magnetic stimulation, cell viability was assessed using CCK-8 assay, while intracellular calcium ion concentration fluctuations were monitored using Fluo-4 AM. ResultsThe findings revealed that, when compared to normal mice, AD mice displayed a notable decline in cognitive function, accompanied by a substantial increase in ferroptosis levels and intracellular calcium ion concentrations. Both high-frequency and low-frequency applications of rTMS were found to significantly ameliorate cognitive impairments in AD mice, while also effectively mitigating the abnormal augmentation of neuronal ferroptosis and intracellular calcium ion levels. ConclusionThe present study underscores that both high-frequency and low-frequency rTMS exhibit efficacy in alleviating cognitive dysfunction in AD mice, potentially through the modulation of ferroptosis and intracellular calcium ion homeostasis.