With the advancement of education,teaching methods have been continuously improved and optimized to en-hance students'learning experiences.In teaching the course of pathophysiology,a core discipline for medical students,integra-tion of Case-Based Learning(CBL)with the flipped classroom model can serve as a powerful pedagogical tool by stimulating students'interest,promoting collaborative learning,enhancing teacher-student interaction,and fostering a more active and en-gaging classroom environment.It also equips students with the confidence to better address real-world medical scenarios.This pa-per examines the application effect of the integrated teaching method on the teaching of pathophysiology and evaluates its pedagog-ical effectiveness.

Peptide-drug conjugates (PDCs) have emerged as a promising modality in precision oncology, enabling targeted delivery of cytotoxic payloads while minimizing off-target toxicity. The integration of covalent warheads, such as those based on sulfur(VI) fluoride exchange (SuFEx) chemistry, enhances drug-target residence time and tumor accumulation. However, existing screening methods for covalent peptide (CP) libraries require post-translational warhead conjugation, limiting throughput. Here, we present an integrated mRNA display platform that incorporates covalent warheads during ribosomal synthesis, enabling efficient screening of ultra-diverse covalent macrocyclic peptide libraries (>10¹³ variants). This approach, using site-specific incorporation of N-chloroacetyl-d-phenylalanine and fluorosulfate-l-tyrosine, accelerated the discovery of irreversibly binding (K _i = 3.58 μmol/L) Nectin-4-targeting peptide CP-N1-N₃ via proximity-triggered SuFEx. The peptide was further conjugated to cytotoxic payloads, yielding the covalent PDC CP-N1-MMAE with potent cytotoxicity (IC₅₀ ≈ 43 nmol/L) against MDA-MB-468 cells. This platform establishes a new paradigm for precision covalent drug discovery.

AIM:To investigate the effect of intrinsic specific transforming growth factor-β(TGF-β)signaling on regeneration and repair of myofibers in acute skeletal myositismice model induced by cardiotoxin(CTX).METHODS:One hundred and eighty-six wild C57BL/6 mice and one hundred and thirty-eight mice with conditional knockout of TGF-β receptor 2(TGF-βr2)in myofibers(SM TGF-βr2-/-mice)were selected.CTX injection to anterior tibial muscle(TA)in-duced acute myoinjury in mice.Some SM TGF-βr2-/-mice were given Smad signaling agonist SRI-011381(SRI)intramus-cular injection.All mice were mainly divided into the following groups:control group,SM TGF-βr2-/-group and SM TGF-βr2-/-+SRI group.Twenty-four mice were selected in each group.RT-qPCR and immunofluorescence staining were used to detect the relative mRNA level,protein expression of inflammatory cytokines and low-density lipoprotein receptor-related protein 1(LRP1),respectively,while the relative protein expression of myosin heavy chain 3(MHY3)and embryonic myosine heavy chain(eMHC)in damaged muscle was detected by Western blot and immunofluorescence staining.In vi-tro,after being extracted from neonatal mice,myogenic precursor cells(MPCs)were cultured in an pro-inflammatory mi-lieu and treated with SRI,recombinant mouse extracellular matrix protein 1(rmECM1)alone or in combination.Hereby,they were divided into the following seven groups:control-MPCs group,control-MPCs+LPS group,TGF-βr2-/--MPCs group,TGF-βr2-/--MPCs+LPS group,TGF-βr2-/--MPCs+LPS+SRI group,TGF-βr2-/--MPCs+LPS+rmECM1 group,and TGF-βr2-/--MPCs+LPS+SRI+rmECM1 group.Six mice were selected in each group.RT-qPCR and Western blot were used to detect the relative mRNA level,protein expression of major histocompatibility complex class I molecules(MHC-I/H-2Kb),major histocompatibility complex class II molecules(MHC-II/H2-Eα),Toll-like receptor 3(TLR3),and LRP1.And the relative protein expression of MoyD and myogenin in myotubes was detected by immunofluorescence staining.RE-SULTS:In vivo,compared with control group,SM TGF-βr2-/-group showed the significant upregulation of pro-inflamma-tory cytokines(P<0.05),and the opposite trend of anti-inflammatory cytokines,LRP1,MHY3,eMHC in the injured muscle(P<0.05),with delayed regeneration and repair of myofibers.In vitro,compared with control-MPCs+LPS group,LRP1,MoyD and myogenin significantly downregulated in TGF-βr2-/--MPCs+LPS group,but the downregulation trend was corrected after giving SRI treatment(P<0.05).In addition,compared with the TGF-βr2-/--MPCs+LPS group,the combi-nation of rmECM1 and SRI significantly upregulated the protein expression of MyoD and myogenin(P<0.05).CONCLU-SION:In a mouse model of acute skeletal myositis,intrinsic TGF-β signaling specifically in myofibers regulates local im-mune behavior.It promotes the expression of LRP1 in damaged muscle via Smad2/3 signaling,and LRP1 can then fully bind to ECM1,thereby facilitating muscle regeneration and repair,and improving the prognosis of acute skeletal myositis.

Objective:To investigate the characteristics of resting-state mirror homotopic connectivity and the gray matter volume of brain in patients with neuropsychiatric systemic lupus erythematosus (NPSLE).Methods:From June 2020 to March 2023, a total of 35 NPSLE patients (NPSLE group) and 30 non-NPSLE patients (non-NPSLE group) were selected from Taizhou People's Hospital Affiliated to Nanjing Medical University, another 31 healthy volunteers were recruited as the healthy controls(HC group). All participants underwent resting-state functional magnetic resonance imaging (rs-fMRI) and mini-mental state examination (MMSE) assessments. The patients in NPSLE and non-NPSLE groups were additionally assessed using the fatigue scale for motor and cognitive functions (FSMC) and the hospital anxiety and depression scale (HADS).The DPABI V7.0 toolkit based on the MATLAB platform was used to preprocess the rs-fMRI data and calculate the voxel-mirrored homotopic connectivity(VMHC) indexes, and the differences in VMHC between groups were evaluated by covariance analysis in SPM12.0 software, and the VMHC values of brain regions with significant differences were extracted for further comparison between the two groups.Partial correlation analysis was performed to investigate the association between VMHC values and clinical parameters in NPSLE patients.The brain regions with significant differences between NPSLE patients and non-NPSLE patients were used as region of interest (ROI), and gray matter volumes within these ROIs were then calculated by VBM8 toolbox.Results:(1)There were statistically significant differences in the VMHC values of bilateral precentral gyrus, bilateral dorsolateral superior frontal gyrus, bilateral medial and paracingulate gyrus, bilateral parahippocampal gyrus, bilateral middle occipital gyrus, bilateral postcentral gyrus, and bilateral superior temporal gyrus among the 3 groups( F=11.246-14.102, all P<0.05). The NPSLE group exhibited significantly lower VMHC values in these regions compared to both the non-NPSLE group and HC group (all P<0.05), but there were no significant differences in these regions between the non-NPSLE group and HC group (all P>0.05).(2) The gray matter volumes of bilateral dorsolateral superior frontal gyrus(right: (0.57±0.11)mm 3, (0.65±0.08)mm 3, t=-3.409, P=0.001; left: (0.53±0.10)mm 3, (0.60±0.07)mm 3, t=-3.082, P=0.003), bilateral precentral gyrus(right: (0.32±0.06)mm 3, (0.35±0.04)mm 3, t=-2.044, P=0.045; left: (0.39±0.06)mm 3, (0.42±0.04)mm 3, t=-2.505, P=0.015), right medial and paracingulate gyrus((0.66±0.08)mm 3, (0.70±0.07)mm 3, t=-2.491, P=0.015) and left superior temporal gyrus((0.57±0.09)mm 3, (0.61±0.06)mm 3, t=- 2.344, P=0.022) in the NPSLE group were smaller than those of non-NPSLE group.(3)Correlation analysis showed that the VMHC value of dorsolateral superior frontal gyrus was positively correlated with IgA level in NPSLE patients ( r=0.353, P=0.047). Conclusion:Patients with NPSLE generally have decreased mirror homotopy functional connectivity in the cerebral hemispheres, accompanied by a decrease in gray matter volume in some brain regions, which can provide a certain neuroimaging basis for the pathogenesis of brain injury.

Objective To investigate the changes in oral microbiota of db/db mice and provide an experimental basis for exploring the relationship between type 2 diabetes mellitus and oral microecology.Methods Eight 10-week-old male db/db mice were designated as the diabetes experimental group(db/db group),while eight 10-week-old male db/m mice were assigned as the normal control group(db/m group).After a 5-day adaptive feeding period,tail venous blood samples were collected on the 6th and 37th days,and fasting blood glucose(FBG)levels and oral glucose tolerance test(OGTT)were performed for both groups to verify the reliability of the diabetes model.On the 15th day of feeding with the same diet,oral microbiota samples were collected from the buccal mucosa,dorsal and ventral tongue surfaces,oral floor mucosa,hard palate mucosa,and the gingival areas of both the upper and lower jaws of the two groups.Genomic DNA from the oral microbiota was extracted,and the V3-V4 regions of the 16S ribosomal RNA(16S rRNA)gene were amplified using a GeneAmp 9700 thermocycler.The composition of the oral microbiota was evaluated through double-labelled amplification and sequencing on the Illumina MiSeq platform,followed by bioinformatics analysis using QI I ME software(version 1.6.0).Results The FBG levels and OGTT results on the 6th and 37th days after the start of the experiment indicated that db/db mice exhibited more pronounced symptoms of type 2 diabetes compared to db/m mice.Alpha diversity(αdiversity)analysis showed no significant difference in the diversity of oral microbiota between the two groups(P＞0.05);however,there was a significant difference in richness(P＜0.05).Principal coordinate analysis(PCoA)revealed differences in the oral microbiota composition between the db/db group and db/m group(P＜0.05).Species composition analysis and LEfSe analysis demonstrated that the relative abundance of oral microbiota in db/db group mice,predominantly composed of p_Proteobacteria,increased significantly at the phylum level(P＜0.05).At the genus level,the relative abundances of g_Proteus and g_Enterococcus showed a significant increase(P＜0.001).Conclusion The composition and diversity of oral microbiota in db/db mice with type 2 diabetes mellitus significantly differed from those without the disease.

Objective:To investigate the characteristics of resting-state mirror homotopic connectivity and the gray matter volume of brain in patients with neuropsychiatric systemic lupus erythematosus (NPSLE).Methods:From June 2020 to March 2023, a total of 35 NPSLE patients (NPSLE group) and 30 non-NPSLE patients (non-NPSLE group) were selected from Taizhou People's Hospital Affiliated to Nanjing Medical University, another 31 healthy volunteers were recruited as the healthy controls(HC group). All participants underwent resting-state functional magnetic resonance imaging (rs-fMRI) and mini-mental state examination (MMSE) assessments. The patients in NPSLE and non-NPSLE groups were additionally assessed using the fatigue scale for motor and cognitive functions (FSMC) and the hospital anxiety and depression scale (HADS).The DPABI V7.0 toolkit based on the MATLAB platform was used to preprocess the rs-fMRI data and calculate the voxel-mirrored homotopic connectivity(VMHC) indexes, and the differences in VMHC between groups were evaluated by covariance analysis in SPM12.0 software, and the VMHC values of brain regions with significant differences were extracted for further comparison between the two groups.Partial correlation analysis was performed to investigate the association between VMHC values and clinical parameters in NPSLE patients.The brain regions with significant differences between NPSLE patients and non-NPSLE patients were used as region of interest (ROI), and gray matter volumes within these ROIs were then calculated by VBM8 toolbox.Results:(1)There were statistically significant differences in the VMHC values of bilateral precentral gyrus, bilateral dorsolateral superior frontal gyrus, bilateral medial and paracingulate gyrus, bilateral parahippocampal gyrus, bilateral middle occipital gyrus, bilateral postcentral gyrus, and bilateral superior temporal gyrus among the 3 groups( F=11.246-14.102, all P<0.05). The NPSLE group exhibited significantly lower VMHC values in these regions compared to both the non-NPSLE group and HC group (all P<0.05), but there were no significant differences in these regions between the non-NPSLE group and HC group (all P>0.05).(2) The gray matter volumes of bilateral dorsolateral superior frontal gyrus(right: (0.57±0.11)mm 3, (0.65±0.08)mm 3, t=-3.409, P=0.001; left: (0.53±0.10)mm 3, (0.60±0.07)mm 3, t=-3.082, P=0.003), bilateral precentral gyrus(right: (0.32±0.06)mm 3, (0.35±0.04)mm 3, t=-2.044, P=0.045; left: (0.39±0.06)mm 3, (0.42±0.04)mm 3, t=-2.505, P=0.015), right medial and paracingulate gyrus((0.66±0.08)mm 3, (0.70±0.07)mm 3, t=-2.491, P=0.015) and left superior temporal gyrus((0.57±0.09)mm 3, (0.61±0.06)mm 3, t=- 2.344, P=0.022) in the NPSLE group were smaller than those of non-NPSLE group.(3)Correlation analysis showed that the VMHC value of dorsolateral superior frontal gyrus was positively correlated with IgA level in NPSLE patients ( r=0.353, P=0.047). Conclusion:Patients with NPSLE generally have decreased mirror homotopy functional connectivity in the cerebral hemispheres, accompanied by a decrease in gray matter volume in some brain regions, which can provide a certain neuroimaging basis for the pathogenesis of brain injury.

AIM:To investigate the effect of intrinsic specific transforming growth factor-β(TGF-β)signaling on regeneration and repair of myofibers in acute skeletal myositismice model induced by cardiotoxin(CTX).METHODS:One hundred and eighty-six wild C57BL/6 mice and one hundred and thirty-eight mice with conditional knockout of TGF-β receptor 2(TGF-βr2)in myofibers(SM TGF-βr2-/-mice)were selected.CTX injection to anterior tibial muscle(TA)in-duced acute myoinjury in mice.Some SM TGF-βr2-/-mice were given Smad signaling agonist SRI-011381(SRI)intramus-cular injection.All mice were mainly divided into the following groups:control group,SM TGF-βr2-/-group and SM TGF-βr2-/-+SRI group.Twenty-four mice were selected in each group.RT-qPCR and immunofluorescence staining were used to detect the relative mRNA level,protein expression of inflammatory cytokines and low-density lipoprotein receptor-related protein 1(LRP1),respectively,while the relative protein expression of myosin heavy chain 3(MHY3)and embryonic myosine heavy chain(eMHC)in damaged muscle was detected by Western blot and immunofluorescence staining.In vi-tro,after being extracted from neonatal mice,myogenic precursor cells(MPCs)were cultured in an pro-inflammatory mi-lieu and treated with SRI,recombinant mouse extracellular matrix protein 1(rmECM1)alone or in combination.Hereby,they were divided into the following seven groups:control-MPCs group,control-MPCs+LPS group,TGF-βr2-/--MPCs group,TGF-βr2-/--MPCs+LPS group,TGF-βr2-/--MPCs+LPS+SRI group,TGF-βr2-/--MPCs+LPS+rmECM1 group,and TGF-βr2-/--MPCs+LPS+SRI+rmECM1 group.Six mice were selected in each group.RT-qPCR and Western blot were used to detect the relative mRNA level,protein expression of major histocompatibility complex class I molecules(MHC-I/H-2Kb),major histocompatibility complex class II molecules(MHC-II/H2-Eα),Toll-like receptor 3(TLR3),and LRP1.And the relative protein expression of MoyD and myogenin in myotubes was detected by immunofluorescence staining.RE-SULTS:In vivo,compared with control group,SM TGF-βr2-/-group showed the significant upregulation of pro-inflamma-tory cytokines(P<0.05),and the opposite trend of anti-inflammatory cytokines,LRP1,MHY3,eMHC in the injured muscle(P<0.05),with delayed regeneration and repair of myofibers.In vitro,compared with control-MPCs+LPS group,LRP1,MoyD and myogenin significantly downregulated in TGF-βr2-/--MPCs+LPS group,but the downregulation trend was corrected after giving SRI treatment(P<0.05).In addition,compared with the TGF-βr2-/--MPCs+LPS group,the combi-nation of rmECM1 and SRI significantly upregulated the protein expression of MyoD and myogenin(P<0.05).CONCLU-SION:In a mouse model of acute skeletal myositis,intrinsic TGF-β signaling specifically in myofibers regulates local im-mune behavior.It promotes the expression of LRP1 in damaged muscle via Smad2/3 signaling,and LRP1 can then fully bind to ECM1,thereby facilitating muscle regeneration and repair,and improving the prognosis of acute skeletal myositis.

Objective To investigate the changes in oral microbiota of db/db mice and provide an experimental basis for exploring the relationship between type 2 diabetes mellitus and oral microecology.Methods Eight 10-week-old male db/db mice were designated as the diabetes experimental group(db/db group),while eight 10-week-old male db/m mice were assigned as the normal control group(db/m group).After a 5-day adaptive feeding period,tail venous blood samples were collected on the 6th and 37th days,and fasting blood glucose(FBG)levels and oral glucose tolerance test(OGTT)were performed for both groups to verify the reliability of the diabetes model.On the 15th day of feeding with the same diet,oral microbiota samples were collected from the buccal mucosa,dorsal and ventral tongue surfaces,oral floor mucosa,hard palate mucosa,and the gingival areas of both the upper and lower jaws of the two groups.Genomic DNA from the oral microbiota was extracted,and the V3-V4 regions of the 16S ribosomal RNA(16S rRNA)gene were amplified using a GeneAmp 9700 thermocycler.The composition of the oral microbiota was evaluated through double-labelled amplification and sequencing on the Illumina MiSeq platform,followed by bioinformatics analysis using QI I ME software(version 1.6.0).Results The FBG levels and OGTT results on the 6th and 37th days after the start of the experiment indicated that db/db mice exhibited more pronounced symptoms of type 2 diabetes compared to db/m mice.Alpha diversity(αdiversity)analysis showed no significant difference in the diversity of oral microbiota between the two groups(P＞0.05);however,there was a significant difference in richness(P＜0.05).Principal coordinate analysis(PCoA)revealed differences in the oral microbiota composition between the db/db group and db/m group(P＜0.05).Species composition analysis and LEfSe analysis demonstrated that the relative abundance of oral microbiota in db/db group mice,predominantly composed of p_Proteobacteria,increased significantly at the phylum level(P＜0.05).At the genus level,the relative abundances of g_Proteus and g_Enterococcus showed a significant increase(P＜0.001).Conclusion The composition and diversity of oral microbiota in db/db mice with type 2 diabetes mellitus significantly differed from those without the disease.

With the advancement of education,teaching methods have been continuously improved and optimized to en-hance students'learning experiences.In teaching the course of pathophysiology,a core discipline for medical students,integra-tion of Case-Based Learning(CBL)with the flipped classroom model can serve as a powerful pedagogical tool by stimulating students'interest,promoting collaborative learning,enhancing teacher-student interaction,and fostering a more active and en-gaging classroom environment.It also equips students with the confidence to better address real-world medical scenarios.This pa-per examines the application effect of the integrated teaching method on the teaching of pathophysiology and evaluates its pedagog-ical effectiveness.

Objective To investigate the effect of E2 signaling in myofibers on muscular macrophage efferocytosis in mice with cardiotoxin-induced acute skeletal muscle injury.Methods Female wild-type C57BL/6 mice with and without ovariectomy and male C57BL/6 mice were given a CTX injection into the anterior tibial muscle to induce acute muscle injury,followed by intramuscular injection of β-estradiol(E2)or 4-hydroxytamoxifen(4-OHT).The changes in serum E2 of the mice were detected using ELISA,and the number,phenotypes,and efferocytosis of the macrophages in the inflammatory exudates and myofiber regeneration and repair were evaluated using immunofluorescence staining and flow cytometry.C2C12 cells were induced to differentiate into mature myotubes,which were treated with IFN-γ for 24 before treatment with β-Estradiol or 4-OHT.The treated myotubes were co-cultured with mouse peritoneal macrophages in a 1:2 ratio,followed by addition of PKH67-labeled apoptotic mouse mononuclear spleen cells induced by UV irradiation,and macrophage efferocytosis was observed using immunofluorescence staining and flow cytometry.Results Compared with the control mice,the female mice with ovariectomy showed significantly increased mononuclear macrophages in the inflammatory exudates,with increased M1 cell percentage,reduced M2 cell percentage and macrophage efferocytosis in the injured muscle,and obviously delayed myofiber regeneration and repair.In the cell co-culture systems,treatment of the myotubes with β-estradiol significantly increased the number and proportion of M2 macrophages and macrophage efferocytosis,while 4-OHT treatment resulted in the opposite changes.Conclusion In injured mouse skeletal muscles,myofiber E2 signaling promotes M1 to M2 transition to increase macrophage efferocytosis,thereby relieving inflammation and promoting muscle regeneration and repair.