Objective To elucidate the molecular mechanism of sirtuin-3 (SIRT3) in regulating mitochondrial biogenesis in human renal tubular epithelial cells. Methods Cells were stimulated with different concentrations of H₂O₂ and divided into four groups: control (NC), 50 μmol/L H₂O₂, 110 μmol/L H₂O₂ and 150 μmol/L H₂O₂. SIRT3 protein expression was then measured. SIRT3 was knocked down with siRNA, and cells were further assigned to five groups: control (NC), negative-control siRNA (NCsi), SIRT3-siRNA (siSIRT3), NCsi+H₂O₂, and siSIRT3+H₂O₂. After 24 h, cellular adenosine triphosphate (ATP) and mitochondrial superoxide anion (O₂•⁻) levels were determined, together with mitochondrial expression of SIRT3, peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1), mitochondrial transcription factor A (TFAM), superoxide dismutase 2 (SOD2), acetylated-SOD2 and adenosine monophosphate activated protein kinase α1 (AMPKα1). Results The 110 and 150 μmol/L H₂O₂ decreased SIRT3 protein (both P<0.05). ATP and mitochondrial O₂•⁻ did not differ between NC and NCsi groups (both P>0.05). Compared to the NCsi group, the siSIRT3 group exhibited elevated O₂•⁻ level, decreased SIRT3 protein and increased expression levels of SOD2 and acetylated SOD2 protein (all P<0.05). Compared to the NCsi group, the NCsi+H₂O₂ group exhibited decreased cellular ATP levels, elevated mitochondrial O₂•⁻ levels, and reduced protein expression levels of SIRT3, SOD2, TFAM, AMPKα1, PGC-1α and NRF1 (all P<0.05). Compared with the siSIRT3 group, the siSIRT3+H₂O₂ group showed a decrease in cellular ATP levels, an increase in mitochondrial O₂•⁻ levels, a decrease in SIRT3, SOD2, TFAM, AMPKα1, PGC-1α and NRF1 protein expression levels and a decrease in acetylated SOD2 protein expression levels (all P<0.05). Compared with the NCsi+H₂O₂ group, the siSIRT3+H₂O₂ group showed a decrease in cellular ATP levels, an increase in mitochondrial O₂•⁻ levels, a decrease in SIRT3, AMPKα1, PGC-1α and NRF1, TFAM protein expression levels, and an increase in SOD2 and acetylated SOD2 protein expression levels (all P<0.05). Conclusions SIRT3 promotes mitochondrial biogenesis in tubular epithelial cells via the AMPK/PGC-1α/NRF1/TFAM axis, representing a key mechanism through which SIRT3 ameliorates oxidative stress-induced mitochondrial dysfunction.

Aim To investigate the pharmacological mechanism of Ebselenin(Ebselen,EbSe)in the treat-ment of Escherichia coli(E.coli)infection,which had no significant inhibitory effect on Gram-negative bacte-ria,based on previous studies.Methods After EbSe intervention in E.coli infected Raw264.7 cells,the via-bility of Raw264.7 cells was determined by CCK-8 method,the morphology and structure of Raw264.7 cells were observed by electron microscope,and the in-tracellular bacterial load of Raw264.7 cells was calcu-lated by coated plate method.Polarization status of peritoneal macrophages,Raw264.7 intracellular NO and ROS content and intracellular HO-1 expression in Raw264.7 and E.coli acutely infected mice after E.co-li infection by flow cytometry.qPCR was used to detect the expression of related mRNAs in Raw264.7 cells.qPCR was used to detect the intracellular GSH content in Raw264.7 cells by spectrophotometric assay,and the state of cytoskeletal proteins was observed by immuno-fluorescence.Western blot assay was performed to de-tect the intracellular Txnrd1 expression level.Results Microtiter method,CCK-8,and electron microscopy observations showed that EbSe had no effect on the growth of E.coli and Raw264.7 cells in vitro.The re-sults of smear plate counting showed that EbSe reduced the intracellular bacterial load of Raw264.7 in the in-fected group.Flow cytometry results showed that EbSe upregulated the number of M2-type macrophages.The EbSe-treated infected group had reduced intracellular NO and ROS levels and increased GSH levels.The qPCR results showed that the expression of IL-6,IL-1β,and iNOS was decreased,and the expression of HO-1,Txnrd1,and Glut1 was increased in DHB4-in-fected Raw264.7 cells after EbSe treatment.Cytoskel-etal staining showed that the morphology of the EbSe-treated infected cells was similar to that of oxPAPC-in-duced cells.Western blot results showed the expres-sion of Txnrd1 protein in EbSe-treated infected cells in-creased.Conclusion EbSe exerts anti-E.coli acute infection effect by regulating macrophage polarization and inhibiting macrophage excessive inflammatory state.

Aim To investigate the expression of or-ganic anion transporting polypeptide 4C1(Oatp4c1)-P-glycoprotein(P-gp)in the kidneys of obese mice in-duced by high-fat diet(HFD),and its impact on the pharmacokinetic changes of digoxin.Methods C57BL/6 mice were randomly divided into the Chow group and the HFD group.Body weight and blood glu-cose were recorded weekly.After successful model es-tablishment,digoxin was intraperitoneally injected,and blood was collected at different time points.Part of the blood samples was used for LC-MS/MS detection,and the other part was used for the detection of other bio-chemical indicators.After 16 weeks,the organs were removed and weighed.HE and immunohistochemical staining was used to observe the renal pathology and the expression of Villin,a marker of proximal tubules.Western blot and qPCR were combined to detect the expression of Villin,Oatp4c1 and P-gp.Results In the HFD group,body weight and blood glucose in-creased significantly.The blood concentration of digox-in rose,the area under the curve increased,and the half-life was prolonged.The proximal tubular epithelial cells shed,and the protein expression of Villin,Oatp4c1 and P-gp decreased significantly.Conclu-sions The down-regulation of Oatp4c1-P-gp expres-sion in the kidneys of HFD mice leads to an increase in the blood concentration of digoxin and a decrease in re-nal clearance.

The scientific research and innovation capabilities of medical students are intrinsically linked to the sustained and high-quality development of national healthcare initiatives.Cultivating outstanding medi-cal students with independent scientific capabilities and innovative consciousness is a critical component in the education and training of high-level medical professionals.Our investigation revealed that within the imperfections of the cultivating model,some faculty and students at medical schools have an insufficient understanding of scientific research and innovation and lack motivation for engaging in such activities,which hinder the progression of scientific research activities.Consequently,we initiated a teaching practice and exploratory study on the"tutorial system"aimed at fostering medical students'scientific research and innovation abilities.Based on the principle of"research informing teaching,teaching and research advan-cing together,"this study implements a"tutorial system"coordinated by tutors,supplemented by graduate and undergraduate student mentors,to cultivate innovative thinking,stimulate interest in scientific re-search,and enhance practical and research skills among medical students.Through collaborative efforts within"scientific research innovation teams,"various educational methods—including preliminary re-search,in-class and extracurricular activities,intra-group and inter-group interactions,and theoretical and practical applications—are employed to improve and strengthen the cultivation of medical students'scientif-ic research and innovation abilities.This study aims to provide valuable references for optimizing medical education management systems and enhancing the quality of medical student training.

Objective To explore the factors that influence major adverse cardiovascular events(MACE)in atrial fibrillation(AF)patients undergoing radiofrequency ablation(RFA),as well as to compare the prognosis of patients with advanced AF to that of the general population.Methods We prospectively recruited AF patients who underwent RFA treatment at Peking University Third Hospital between January 2021 and March 2023.General patient data were collected through the hospital's inpatient system,and MACE were tracked through outpatient visits and telephone follow-ups.Patients were categorized into three age groups:Group 1(under 65 years),Group 2(65 to 75 years),and Group 3(over 75 years).In this study,MACE was defined as include cardiovascular death,all-cause death,readmission for heart failure,acute coronary syndrome(ACS),grade 2 or higher bleeding and stroke.Results A total of 431 patients were included in this study,with an average age of(66.17±12.22)years.Among these patients,259 were male(60.09％),and the mean of CHA2DS2-VASc score was(1.79±1.30).The median follow-up period was 16.0(11.3,21.3)months,during which 28(6.50％)patients experienced MACE,with ACS and stroke being the most common events.Variables were selected using LASSO regression,and a LASSO-Cox regression model was constructed.Age(HR 1.06,95％CI 1.02-1.10,P=0.006)and hypertrophic cardiomyopathy(HR 3.70,95％CI 1.27-8.68,P=0.008)were identified as independent predictors of MACE after RFA for AF.Subgroup analysis revealed that patients under 65 had significantly better prognoses compared to older AF patients(P=0.030 compared with group 2;P=0.021 compared with group 3).Conclusions Age and hypertrophic cardiomyopathy are independent risk factors for MACE in AF patients undergoing RFA.The prognosis for younger patients is better than that for older patients,while the prognosis for advanced patients is comparable to that of patients aged 65-75 years.

AIM To compare total sugar,total protein,total phenol,total flavonoid,calycosin-7-O-β-D-glucoside,liquiritin,lobetyolin,quercetin,isoferulic acid,hesperidin,glycyrrhizic acid contents and their antioxidant activities,hypoglycemic activities of big honey pill,small honey pill,water pill,concentrated pill,granule,mixture and decoction of Buzhong Yiqi Recipe.METHODS Anthraquinone-sulfuric acid method,Coomassie brilliant blue method,Folin-phenol colorimetry method,sodium nitrite-aluminum nitrate method and HPLC were adopted in the content determination of total sugar,total protein,total phenol,total flavonoid and seven constituents,respectively,after which the scavenging capacities,reducing powers on DPPH·free radical,ABTS+free radical,hydroxyl free radical,and inhibition capacity on α-glucosidase activity were detected.Subsequently,correlation analysis was performed.RESULTS Total sugar,total protein,total phenol and total flavonoid contents demonstrated significant differences among different dosage forms(P＜0.05,P＜0.01).Calycosin-7-O-β-D-glucoside,glycyrrhizin,codonoside and quercetin displayed the highest contents in the decoction,while those of isoferulic acid,hesperidin and glycyrrhizin were observable in the mixture.The water pill exhibited the strongest antioxidant activity,while those of the concentrated pill and mixture were weak;the big honey pill exhibited the strongest hypoglycemic activity,while that of the decoction was the weakest.Total protein,total phenol,total flavonoid and liquiritin contents displayed significant positive correlations between antioxidant activity(P＜0.05,P＜0.01),while hesperidin content displayed significant negative correlation between the latter(P＜0.05);total protein,calycosin-7-O-β-D-glucoside,codonoside and quercetin contents displayed significant negative correlations between hypoglycemic activity(P＜0.05,P＜0.01).CONCLUSION Active constituent contents and their biological activities of Buzhong Yiqi Recipe with different dosage forms exist differences,total sugar,total protein,total flavonoids,calycosin-7-O-β-D-glucoside,licorice glycoside,hesperidin,codonoside and quercetin can be taken as quality control indices for this prescription.

Objective To identify biomarkers that characterize its bitter-cold properties of Scutellaria Radix on the basis of evaluating its cold and hot properties,as well as possible metabolic pathways and related targets;To explore its molecular mechanism.Methods Totally 40 mice were randomly divided into a control group and a treatment group,and were orally administered with normal saline and Scutellaria Radix decoction,respectively,for 4 consecutive days.The cold and hot plate differential method was used to evaluate the cold and hot tendencies of the mice;UPLC-MS/MS technology was used to analyze mouse blood samples,differential metabolites were screened using principal component analysis,partial least squares discriminant analysis and orthogonal partial least squares discriminant analysis methods,and metabolic pathway analysis was performed;network modular analysis of differential metabolites was performed using Cytoscape 3.9.0 software to identify potential molecular targets.Results On the second day of administration,the anal temperature of mice in the treatment group decreased significantly compared to the control group(P<0.01);in the cold and hot tendency test,the mice in the treatment group showed an overall increase in high-temperature tendency and a higher proportion of high-temperature zone retention.There was a statistically significant difference(P<0.01,P<0.05)between the treatment group and the control group on the 2nd and 3rd day of treatment;the pattern recognition analysis of serum metabolome data showed that the serum samples of the treatment group and the control group could be completely separated,and a total of 14 differential metabolites were screened out;metabolic pathway analysis identified 16 related pathways,including unsaturated fatty acid biosynthesis,linoleic acid metabolism,citric acid cycle(TCA cycle),arachidonic acid metabolism,glycine,serine and threonine metabolism,steroid hormone biosynthesis,etc.;a total of 16 modules were obtained through network modular analysis,among which the arachidonic acid metabolism pathway and linoleic acid metabolism pathway modules were larger;the nodal degree values of arachidonic acid and linoleic acid were greater than the mean,involving arachidonic acid metabolism and linoleic acid metabolism pathways;by screening 26 genes associated with the cytochrome P450 enzyme system were obtained.Conclusion Scutellaria Radix may regulate the body's energy metabolism,achieve its biological effects,and characterize its medicinal properties by intervening in metabolic pathways such as arachidonic acid and linoleic acid.

Aim To investigate the pharmacological mechanism of Ebselenin(Ebselen,EbSe)in the treat-ment of Escherichia coli(E.coli)infection,which had no significant inhibitory effect on Gram-negative bacte-ria,based on previous studies.Methods After EbSe intervention in E.coli infected Raw264.7 cells,the via-bility of Raw264.7 cells was determined by CCK-8 method,the morphology and structure of Raw264.7 cells were observed by electron microscope,and the in-tracellular bacterial load of Raw264.7 cells was calcu-lated by coated plate method.Polarization status of peritoneal macrophages,Raw264.7 intracellular NO and ROS content and intracellular HO-1 expression in Raw264.7 and E.coli acutely infected mice after E.co-li infection by flow cytometry.qPCR was used to detect the expression of related mRNAs in Raw264.7 cells.qPCR was used to detect the intracellular GSH content in Raw264.7 cells by spectrophotometric assay,and the state of cytoskeletal proteins was observed by immuno-fluorescence.Western blot assay was performed to de-tect the intracellular Txnrd1 expression level.Results Microtiter method,CCK-8,and electron microscopy observations showed that EbSe had no effect on the growth of E.coli and Raw264.7 cells in vitro.The re-sults of smear plate counting showed that EbSe reduced the intracellular bacterial load of Raw264.7 in the in-fected group.Flow cytometry results showed that EbSe upregulated the number of M2-type macrophages.The EbSe-treated infected group had reduced intracellular NO and ROS levels and increased GSH levels.The qPCR results showed that the expression of IL-6,IL-1β,and iNOS was decreased,and the expression of HO-1,Txnrd1,and Glut1 was increased in DHB4-in-fected Raw264.7 cells after EbSe treatment.Cytoskel-etal staining showed that the morphology of the EbSe-treated infected cells was similar to that of oxPAPC-in-duced cells.Western blot results showed the expres-sion of Txnrd1 protein in EbSe-treated infected cells in-creased.Conclusion EbSe exerts anti-E.coli acute infection effect by regulating macrophage polarization and inhibiting macrophage excessive inflammatory state.

Aim To investigate the expression of or-ganic anion transporting polypeptide 4C1(Oatp4c1)-P-glycoprotein(P-gp)in the kidneys of obese mice in-duced by high-fat diet(HFD),and its impact on the pharmacokinetic changes of digoxin.Methods C57BL/6 mice were randomly divided into the Chow group and the HFD group.Body weight and blood glu-cose were recorded weekly.After successful model es-tablishment,digoxin was intraperitoneally injected,and blood was collected at different time points.Part of the blood samples was used for LC-MS/MS detection,and the other part was used for the detection of other bio-chemical indicators.After 16 weeks,the organs were removed and weighed.HE and immunohistochemical staining was used to observe the renal pathology and the expression of Villin,a marker of proximal tubules.Western blot and qPCR were combined to detect the expression of Villin,Oatp4c1 and P-gp.Results In the HFD group,body weight and blood glucose in-creased significantly.The blood concentration of digox-in rose,the area under the curve increased,and the half-life was prolonged.The proximal tubular epithelial cells shed,and the protein expression of Villin,Oatp4c1 and P-gp decreased significantly.Conclu-sions The down-regulation of Oatp4c1-P-gp expres-sion in the kidneys of HFD mice leads to an increase in the blood concentration of digoxin and a decrease in re-nal clearance.

Objective To investigate the effects of m6A methylation modification and changes in oxidative stress levels on the progression of colorectal cancer(CRC)in Apemin/+mice with normal and high-fat diets.Methods C57BL/6J mice and Apcmin/+mice were fed with a normal or high-fat diet(60％fat)for 2(S group),6(M group),or 12 weeks(L group),respectively.Food intake,body mass,and the size,number,and volume of small intestinal polyps and colon tumors were then measured.Protein expression levels of the cancer markers Ki-67 and proliferating cell nuclear antigen in colon tissues were detected by immunohistochemical staining and the serum levels or activities of the antioxidant enzymes catalase,reduced glutathione,and lipid peroxide malondialdehyde were detected using appropriate kits.mRNA expression levels of m6A methylation-related enzymes in colon tissues were detected by RT-qPCR and total levels of m6A methylation modification in colon tissues were detected.Results(1)Apcmin/+mice showed rapid tumor growth from the early to middle stages of cancer.Tumor proliferation from the middle to late stages of cancer was slowed in mice fed a normal diet,while a high-fat diet promoted the further development of cancer.(2)Decreased m6A methylation levels and enhanced antioxidant capacity may have delayed advanced tumor development in Apcmin/+mice fed a normal diet.(3)In contrast,a high-fat diet may have promoted the sustainable development of CRC by increasing the total level of m6A methylation,while the enhanced antioxidant capacity may have been insufficient to resist the promoting effect of m6A methylation on CRC.Conclusions A high-fat diet may promote the advancement of CRC compared with a normal diet by affecting m6A methylation modification.Both normal and high-fat diets enhanced the antioxidant capacity,suggesting that antioxidant effects may initiate self-protection mechanisms during cancer progression.