Objective:To construct the over-expressed lentivirus vector of PRDM5 gene and establish the Neuro-2a cells stably transfected PRDM5,and to provide the basis evidence for exploring the effect of PRDM5 in pathogenesis of ischemic stroke(IS).Methods:The sequence of PRDM5 was searched and designed based on NCBI.The PRDM5 gene was amplified by PCR and ligated with the lentiviral vector GV492 digested by BamH Ⅰ and Age Ⅰ restriction enzymes to form the GV492-PRDM5 over-expression recombinant plasmid.The positive clones with similar length and size to the target gene fragment were screened by PCR and sent to Shenggong Bioengineering(Shanghai)Co.Ltd.for identification.The correctly-sequenced GV492-control plasmid and GV492-PRDM5 over-expression recombinant plasmid were transfected into the HEK293T cells,respectively.After 48 h of transfection,the lentiviruses were collected by centrifugation,and they were GV492-control lentivirus and GV492-PRDMS over-expression lentivirus;the titers of these two lentiviruses were determined by lentiviral titer assay.The Neuro-2a cells were divided into GV492-control group and GV492-PRDM5 group,and then infected with GV492-control lentivirus and GV492-PRDM5 over-expression lentivirus,respectively,with a lentivirus multiplicity of infection(MOI)of 100.The Neuro-2a cells successfully infected with GV492-control lentivirus and GV492-PRDM5 over-expression lentivirus were screened with puromycin(10 mng-L-1)after 72 h of infection.The growth status and the expression of green fluorescence protein of Neuro-2a cells in GV492-control group and GV492-PRDM5 group were observed by fluorescence microscope.The expression levels of PRDM5 mRNA and PRDM5 protein in the Neuro-2a cells in two groups were detected by real-time fluorescence quantitative RCR(RT-qPCR)and Western blotting methods.Results:The PCR results showed that the length of the positive transformant of GV492-PRDM5 recombinant plasmid was about 684 bp,and the gene sequence of GV492-PRDM5 over-expression recombinant plasmid was consistent with the designed and synthesized PRDM5 over-expression sequence.The titers of GV492-control lentivirus and GV492-PRDM5 over-expression lentivirus were both 2.5×108TU·mL-1 The Neuro-2a cells in GV492-control group and GV492-PRDM5 group grew well,and the expressions of green fluorescence protein were found under fluorescence microscope.The RT-qPCR results showed that the expression level of PRDM5 mRNA in the Neuro-2a cells in GV492-PRDM5 group was significantly increased compared with GV492-control group(P＜0.01).The Western blotting results showed that the specific bands appeared in the Neuro-2a cells in GV492-control group and GV492-PRDM5 group with a relative molecular weight of 75 000;compared with GV492-control group,the expression level of PRDM5 protein in the Neuro-2a cells in GV492-PRDM5 group was increased(P＜0.01).Conclusion:The over-expression lentivirus vector of PRDM5 gene is successfully constructed,and the stably transfected GV492-PRDM5-Neuro-2a cells are established.

Objective:To discuss the anti-tumor effect of low dose of methotrexate(MTX)combined with sorafenib(SFN)on the human osteosarcoma(OS),and to clarify the possible mechanism.Methods:Four types of human OS cells(143B cells,HOS cells,U2OS cells,and MG63 cells)were cultured in vitro.Western blotting method was used to detect the expression levels of vascular endothelial growth factor(VEGF)and vascular endothelial growth factor receptor 2(VEGFR2)proteins in the above four kinds of cells.The human OS xenograft model was established in the nude mice,and 20 successfully modeled BALB/C nude mice were randomly divided into control group(given 2％dimethyl sulfoxide+98％corn oil),low dose of MTX group(given 2 mng·kg-1 MTX),SFN group(given 15 mng·kg-1 SFN),and combined drug group(given 2 mng·kg-1 MTX+15 mng·kg-1 SFN);there were 5 mice in each group.The tumor volumes of the mice in various groups were detected and tumor growth curves were plotted;HE staining was used to observe the morphology of tumor tissue of the mice in various groups;immunohistochemistry was used to detect the positive expression rates of VEGFR2,proliferation marker Ki-67,and hypoxia-inducible factor-1(HIF-1)proteins in tumor tissue of the mice in various groups.The human OS 143B cells were divided into 0,0.125,0.250,0.500,1.000,2.000,and 4.000 μmol·L-1 MTX groups(given 0,0.125,0.250,0.500,1.000,2.000,and 4.000 μmol·L-1 MTX,respectively).CCK-8 method was used to detect the proliferation rates of the 143B cells in various groups,and half inhibityory concentration(IC50)was calculated;the concentration of MTX that had no effect on 143B cell survival was selected as low dose of MTX.The human OS 143B cells were divided into control and low dose of MTX groups(given 0 and 0.250 μmol·L-1 MTX).ELISA method was used to detect the levels of VEGF in the 143B cells in various groups.Results:Compared with 143B cells,the expression levels of VEGF and VEGFR2 proteins in the HOS cells,U2OS cells,and MG63 cells were significantly increased(P＜0.001).In the xenograft model,compared with control group,the tumor volumes of the mice in SFN group,and combined drug group were decreased(P＜0.001);compared with low dose of MTX group and SFN group,the tumor volume of the mice in combined drug group was decreased(P＜0.01).The immunohistochemical results showed that compared with control group,the positive expression rates of Ki-67,VEGFR2,and HIF-1 proteins in tumor tissue of the mice in combined drug group were significantly decreased(P＜0.05).The CCK-8 results showed that there was no change in the proliferation of the 143B cells treated with 0.25 μmol·L-1 MTX.The ELISA results showed that compared with control group,the level of VEGF in the 143B cells in MTX group was signyicantly decreased(P＜0.05).Conclusion:Low dose of MTX enhances the anti-tumor effect of SFN on the human OS,which may be due to the inhibition of VEGF secretion by the OS cells,thereby enhancing the anti-tumor effect of SFN on the human OS.

Objective:To discuss the effect of prostaglandin E2(PGE2),a pyrogenic mediator,on the discharge activity of warm-sensitive neurons(WSNs)in median preoptic nucleus(MnPO)of hypothalamus in the female mice,and to clarify its mechanism.Methods:Coronal brain slices of MnPO were prepared from the female mice.The slices were then perfused with artificial cerebrospinal fluid(ACSF)containing synaptic transmission blockers(STBs).The discharge frequency was monitored using the patch clamp technique while changing the temperature of the perfusate to identify the WSNs.A total of 32 MnPO WSNs were divided into base line group(n=32)and PEG2(n=32).The patch clamp technique was employed to monitor the discharge frequencies of MnPO WSNs following the perfusion of ACSF and 1 μmol·L-1 PGE2,respectively.The MnPO WSNs with good activity and significant change in discharge frequency after PGE2 perfusion were divided into PGE2 receptor E-series prostaglandin receptrol(EP)1 antagonist(EP1 ant)+PGE2 group(n=7),EP3 ant+PGE2 group(n=7),and EP4 ant+PGE2 group(n=7).The patch clamp technique was used to monitor the discharge frequencies of MnPO WSNs following the perfusion of 3 μmol·L-1 EP1 ant and 1 μmol·L-1 PGE2 mixture,10 μmol·L-1 EP3 ant and 1 μmol·L-1 PGE2mixture,and 10 μmol·L-1 EP4 ant and 1 μmol·L-1 PGE2 mixture,respectively.Resluts:After perfuson of the ACSF containing STBs,a total of 188 MnPO neurons from the female mice with an intrinsic temperature sensitivity coefficient(m value)were identified;out of these,32 neurons had an m value of ≥0.8 and were identified as MnPO WSNs,accounting for approximately 17％of all recorded neurons.Compared with baseline discharge frequency,the discharge frequency of MnPO WSNs after addition of PGE2 was decreased(P＜0.05).Compared with PGE2 group,the percentage change in discharge frequency of MnPO WSNs in EP3 ant+PGE2 group was significantly decreased(P＜0.05).Compared with PGE2 group,the percentage change in discharge frequency of MnPO WSNs in EP1 ant+PGE2 group had no significant difference(P＞0.05).Compared with PGE2 group,the percentage change in discharge frequency of MnPO WSNs in EP4 ant+PGE2 group had no significant difference(P＞0.05).Conclusion:In the female mice,WSNs make up approximately 17％of the total neurons in MnPO.PGE2 can directly inhibit the discharge activity of MnPO WSNs in the female mice through postsynaptic mechanism involving EP3 receptors.

Objective:To discuss the effect of angiotensin(1-7)[Ang(1-7)]on high-turnover bone disease in the uremic rats,and to clarify its possible mechanism.Methods:Thirty SD rats were randomly divided into sham operation group(n=6)and experimental group(n=24).The rats in experimental group underwent 5/6 nephrectomy(Platt method)+high-phosphorus(P)diet[1.2％P,1.0％calcium(Ca)]to establish the model of uremic high-turnover bone disease.The successfully modeled rats were then randomly divided into model group,Ang(1-7)group,angiotensin-converting enzyme 2(ACE2)activator dimethylacetamide amidoxime(DIZE)group,and Mas receptor antagonist group(A779 group),with 6 rats in each group.The levels of Ca,P,blood creatinine(Scr),blood urea nitrogen(BUN),and 24 h urinary protein(UP)in serum of the rats in various groups were detected by automatic biochemical analyzer at 12 and 18 weeks after operation;immunofluorescence staining was used to detect the levels of intact parathyroid hormone(iPTH)in the rats in various groups;ELISA method was used to detect the levels of osteocalcin(OC),type Ⅰ collagen N-terminal peptide(NTX),and tartrate-resistant acid phosphatase(TRAP)-5b in serum of the rats in various groups;high-resolution micro-CT scan was used to detect the bone density(BMD),tissue mineral density(TMD),trabecular thickness(Tb.Th),and trabecular separation(Tb.Sp)in femur tissue of the rats in various groups;Von Kossa staining and Giemsa staining were used to observe the pathomorphology of cortical bone and trabecular bone of the rats in various groups,and the trabecular bone volume(TBV)was calculated;fluorescence microscope was used to detect the mineral apposition rates(MAR)of the rats in vanious groups,and the osteoblast index(OBI)and osteoclast index(OCI)of the rats in various groups were calculated.Results:At 12 and 18 weeks after operation,compared with sham operation group,the weights of the rats in model group,Ang(1-7)group,DIZE group,and A779 group were decreased(P＜0.05).At 12 and 18 weeks after operation,compared with sham operation group,the levels of 24 h UP,Scr,and BUN in serum of the rats in model group,Ang(1-7)group,DIZE group,and A779 group were increased(P＜0.05);at 18 weeks after operation,compared with model group,the levels of 24 h UP and Scr in serum of the rats in Ang(1-7)group and DIZZ group were decreased(P＜0.05),and the levels of 24 h UP,Scr and BUN in serum of the rats in A779 group were increased(P＜0.05).The successful establishment of the uremic high-turnover bone disease model was confirmed.At 12 and 18 weeks after operation,compared with sham operation group,the serum iPTH,P,OC,NTX,and TRAP-5b levels ofthe rats in model group,Ang(1-7)group,DIZE group,and A779 group were all significantly increased(P＜0.05);at 18 weeks after operation,compared with model group,the serum NTX and TRAP-5b levels of the rats in Ang(1-7)group and DIZE group were decreased(P＜0.05),while the serum iPTH,P,NTX and TRAP-5b levels in A779 group were increased(P＜0.05).The high-resolution micro-CT scan results showed that compared with sham operation group,the values of femur BMD and TMD of the rats in model group,Ang(1-7)group,DIZE group,and A779 group were all significantly decreased(P＜0.05);compared with model group,the values of femur BMD and TMD of the rats in Ang(1-7)group and DIZE group were increased(P＜0.05),while the values of BMD and TMD of the rats in A779 group were decreased(P＜0.05).Compared with sham operation group,the femur Tb.Th of the rats in model group was decreased(P＜0.05),and the Tb.Sp was increased(P＜0.05);the femur Tb.Th of the rats in Ang(1-7)group and DIZE group were increased(P＜0.05),and the Tb.Sp was decreased(P＜0.05).Compared with model group,the femur Tb.Th of the rats in A779 group was decreased(P＜0.05),and the Tb.Sp was increased(P＜0.05).The bone pathological examination results showed that compared with sham operation group,the femur TBV of the rats in model group,Ang(1-7)group,DIZZ group and A779 group were decreased(P＜0.05),and MAR,OBI and OCI were increased(P＜0.05);compared with model group,the OBI and OCI of the rats in Ang(1-7)group and DIZE group were decreased(P＜0.05),and TBV was increased(P＜0.05),while the OBI and OCI of the rats in A779 group were increased(P＜0.05),and TBV was decreased(P＜0.05).Conclusion:The ACE2/Ang(1-7)/Mas axis improves high-turnover bone disease in the uremic rats.

Objective:To investigate the expressions of cystathionine-β-synthase(CBS)and cystathionine-γ-lyase(CSE)and their effects on the malignant biological behaviours of breast cancer cells,and to elucidate their mechanisms.Methods:The breast cancer tissue and paracancerous normal tissue from 15 cases of patients were selected,and RT-qPCR and Western blotting methods were used to detect the mRNA and protein expression levels of CBS and CSE in breast cancer tissue,paracancerous normal tissue,MCF-7 cells,and MDA-MB-231 cells.The MCF-7 cells were divided into siNC group(transfected with siNC)and siCBS group(transfected with siCBS),and the MDA-MB-231 cells were divided into ovNC group(transfected with CSE over-expression empty plasmid)and ovCSE group(transfected with CSE over-expression plasmid).CCK8 assay was used to detect the proliferation activities of breast cancer cells in various groups,Transwell assay was used to detect the numbers of migration and invasion cells in various groups,and Western blotting method was used to detect the protein expression levels of E-cadherin,N-cadherin and Vimentin proteins in the breast cancer cells in various groups.Results:Compared with paracancerous normal tissue,the expression levels of CBS and CSE mRNA and proteins in breast cancer tissue were increased(P＜0.05 or P＜0.01).Compared with MDA-MB-231 cells,the CBS mRNA expression level in the MCF-7 cells was increased(P＜0.05);compared with MCF-7 cells,the expression level of CSE protein in the MDA-MB-231 cells was decreased(P＜0.05).Compared with siNC group,the proliferation activity,the numbers of migration and invasion cells,the expression levels of N-cadherin and Vimentin proteins in the MCF-7 cells in siCBS group were significantly decreased(P＜0.05),and the expression level of E-cadherin protein was increased(P＜0.05).Compared with ovNC group,the proliferation activity,the numbers of migratoin and invasion cells,and the expression levels of N-cadherin and Vimentin proteins in the MDA-MB-231 cells in ovCSE group were increased(P＜0.05),while the expression level of E-cadherin protein was significantly decreased(P＜0.05).Conclusion:The expressions of CBS and CSE are upregulated in breast cancer tissue,and high levels of CBS and CSE promote proliferation,migration,invasion and epithelial-mesenchymal transition(EMT)of breast cancer cells.

Objective:To discuss the inhibitory effect of schisandrin B(SchB)on the migration and invasion of the pancreatic cancer Pan02 cells,and to clarify its mechanism.Methods:The pancreatic cancer Pan02 cells were treated with different concentrations of SchB(0,0.78,1.56,3.12,6.25,12.50,and 25.00 mg·L-1)for 24,48,and 72 h.CCK-8 method was used to detect the survival rates of the cells in various groups,and the concentration of SchB for the subsequent experiments was confirmed.The Pan02 cells were divided into control group,2.5 mg·L-1 SchB group,5.0 mg·L-1 SchB group,and 10.0 mg·L-1 SchB group.Wound healing assay was used to detect the wound healing rates of the Pan02 cells in various groups;Transwell chamber assay was used to detect the numbers of migration and invasion Pan02 cells in various groups;Western blotting method was used to detect the expression levels of Vimentin and N-cadherin proteins in the Pan02 cells in various groups.The mouse models of subcutameous transplanted tumor of pancreatic cancer cells were established.Ten successfully modeling mice were randomly divided into control group and SchB group(n=5).After 28 d of treatment,the weights of tumor of the mice were determined;immunohistochemistry method was used to detect the expressions of Vimentin and N-cadherin proteins in tumor tissue of the mice in various groups.Results:The CCK-8 results showed that compared with control group,the survival rates of the pancreatic cancer Pan02 cells in different concentrations of SchB groups were decreased(P＜0.05 or P＜0.01).The wound healing results showed that compared with control group,the wound healing rates of the cells in 2.5,5.0,and 10.0 mg·L-1 SchB groups were decreased(P＜0.05 or P＜0.01).The Transwell chamber results showed that compared with control group,the numbers of migration and invasion Pan02 cells in 2.5,5.0,and 10.0 mng·L-1SchB groups were decreased(P＜0.05 or P＜0.01).The Western blotting results showed that compared with control group,the expression levels of Vimentin and N-cadherin proteins in the Pan02 cells in 2.5,5.0,and 10.0 mg·L-1 SchB groups were decreased(P＜0.05 or P＜0.01).Compared with control group,the tumor volume and weight of the mice in SchB group were significantly decreased(P＜0.01).The immunohistochemistry results showed that compared with control group,the positive expression rates of Vimentin and N-cadherin proteins in tumor tissue of the mice in SchB group were significantly decreased(P＜0.01).Conclusion:SchB can inhibit the proliferation,migration,and invasion of the pancreatic cancer Pan02 cells,and its mechanism is related to the reduction of expressions of Vimentin and N-cadherin proteins.

Objective:To construct an eukaryotic expression vector pcDNA3.1-MYC-SGK1-mcherry which containing mouse serum and glucocorticoid-induced kinase(SGK)1 gene,and to observe its expression in the transfected HEK293 cells.Methods:The SGK1 target gene segments were amplified by PCR method,and the segments were ligated to the pcDNA3.1-MYC-C-mcherry vector which was doubly-digested with Hind Ⅲ and Sbf Ⅰ.After successful verification by enzyme digestion and sequencing,the pcDNA3.1-MYC-SGK1-mcherry expression vector was transfected into the HEK293 cells by liposome transfection.Western blotting method was used to determine the expression level of eukaryotic expression vector in the cells.Results:The vector band was located at 5 200 bp and the target gene band was located at 3 100 bp,which was consistent with the expected results.The sequencing results were also consistent when compared with the expected sequence by Snap Gene software,which indicated that the eukaryotic expression vector pcDNA3.1-MYC-SGK1-mcherry was successfully constructed.Successful expression of the eukaryotic expression vector pcDNA3.1-MYC-SGK1-mcherry was observed by Western blotting method,in which the transfected cells showed well-defined bands near the relative molecular mass of 49 000.Conclusion:The eukaryotic expression vector pcDNA3.1-MYC-SGK1-mcherry is successfully constructed,laying a solid foundation for the subsequent study on the transition mechanism of SGK1 gene in the early development of mouse fertilized egg cells.

Objective:To investigate the effect of nuclear receptor subfamily 2 group F member 2(NR2F2)on the biological behaviors of human ovarian cancer SKOV3 cells,and to clarify its molecular mechauism and provide the new idea for treatment of ovarian cancer.Methods:Gene Expression Profiling Interactive Analysis(GEPIA)Database analyse the expression level of NR2F2 gene in ovarian tissue,and analyse its correlation with clinical prognosis of ovarian cancer patients.The human ovarian cancer SKOV3 cells were divided into control group and NR2F2 over-expression(NR2F2 OE)group,which were transfected with mCherry control virus and NR2F2 OE over-expression virus,respectively,when the cell deusity reached 70％,and the stable transfection SKOV3 cell lines were screened with puromycin(puro)48h lafter.Real-time fluorescence quantitative PCR(RT-qPCR)and Western blotting methods were used to detect the transfection efficiencies of the cells;RT-qPCR method was used to detect the expression levels of NR2F2 and sex-determining region Y-box 2(SOX2)mRNA in the cells in two groups;Western blotting method was used to detect the expression levels of NR2F2,ATP-binding cassette superfamily G member 2(ABCG2),and programmed cell death 1-ligand 1(PD-L1)protcins in the cells in two groups.CCK-8 assay was used to detect the proliferation activities of the cells in two groups;Wound assay was used to detect the migration rates of the cells in two groups;Transwell chamber assay was used to detect the number of transmembrane cells;Spheroidization assay was used to detect the numbers of spheroids in the cells;peripheral blood mononuclear cells(PBMCs)-mediated tumor cell killing assay was used to detect the relative densities of surviving tumor cells;CCK-8 assay was used to detect the half maximal inhibitory concentration(IC50)of paclitaxel(PTX)and carboplatin(CBP).Results:Compared with normal ovarian tissue,the expression level of NR2F2 gene in ovarian tumor tissue was decreased(P＜0.05),and decreased with the improvement of clinical pathological grading of ovarian tumor.The patients with higher expression level of NR2F2 gene had better clincal prognosis.The SKOV3 cells with NR2F2 over-expresson were successfully constructed,and the expression levels of NR2F2 mRNA and protein in the cells in NR2F2 OE group were increased compared with control group(P＜0.001).The CCK-8 assay results showed that compared with control group,the proliferation activities of the cells in NR2F2 OE group were decreased at different time points(1,2,3,and 4 d)(P＜0.05 or P＜0.01).The cell wound assay results showed that compared with control group,the migration rate of the cells in NR2F2 OE group was decreased(P＜0.001).The Transwell assay results showed that compared with control group,the number of transmembrane cells in NR2F2 OE group was decreased(P＜0.01).Compared with control group,the number of the spheroids in NR2F2 OE group was decreased(P＜0.05),and the expression levels of SOX2 mRNA(P＜0.01)and protein(P＜0.001)were increased.Compared with control group,the relative density of surviving tumor cells in NR2F2 OE group was decreased,but the difference was not significant(P＜0.05),and the expression level of PD-L1 protein was decreased(P＜0.05).Compared with control group,the proliferation activities of cells in NR2F2 OE group were decreased(P＜0.05),and the drug sensitivities of the cells to PTX and CBP were enhanced(P＜0.05);the IC50 of PTX was significantly reduced,while the IC50of CBP could not be calculated due to excessively high drug concentration;the expression level of ABCG2 protein was decreased(P＜0.05).Conclusion:The over-expression of NR2F2 may inhibit the proliferation,migration,and invasion of the human ovarian cancer SKOV3 cells,decrease the expression levels of SOX2,PD-L1 and ABCG2 proteins,suppress the stemness and immune evasion ability of the SKOV3 cells,and enhance the sensitivities of the SKOV3 cells to PTX and CBP.

Objective:To discuss the effect of Yes-associated protein(YAP)silencing on the proliferation,migration,and invasion capabilities of the human cervical cancer(CC)SiHa cells.Methods:The human CC SiHa cells were cultured in vitro,and the lentiviral YAP shRNA was transfected into the SiHa cells to establish stably transfected YAP-shRNA experimental group(sh-YAP group)and empty plasmid control group(control group).Western blotting method was used to detect the silencing effect of YAP;immunofluorescence method was used to detect the microfilament number and morphology of actin filaments(F-actin)in the cells in both groups;CCK-8 method was used to detect the survival rates of the cells in two groups;Transwell chamber assay and wound healing assay were used to detect the numbers of migration and invasion cells and scratch healing rates of the cells in two groups;Western blotting method was used to detect the expression levels of epithelial-mesenchymal transition(EMT)markers(E-cadherin and Snail),DNA damage repair-related proteins(γ-H2AX),and apoptosis-related proteins[c-MYC and B-cell lymphoma-2(Bcl-2)]in the cells in two groups.Results:The results of lentiviral YAP shRNA transfection into SiHa cells showed that the expression level of YAP protein in the SiHa cells was significantly decreased(P＜0.05).The immunofluorescence results showed that after YAP silencing,the F-actin in SiHa cells was sparse and regularly arranged,with a reduced number of cells and a shriveled appearance.The CCK-8 results showed that compared with control group,the survival rate of the SiHa cells in sh-YAP group was significantly decreased cultured for 24 and 48 h(P＜0.01).The results of Transwell chamber assay and the wound healing assay showed that compared with control group,the numbers of migration and invasion SiHa cells in sh-YAP group were significantly decreased(P＜0.01),and the cell scratch healing rates were signifiantly decreased(P＜0.05).The Western blotting results showed that compared with control group,the expression level of E-cadherin protein in the cells in sh-YAP group was increased(P＜0.05),and the expression levels of c-MYC,Bcl-2,and γ-H2AX proteins were decreased(P＜0.05 or P＜0.01).Conclusion:YAP gene silencing leads to the depolymerization of F-actin in the human CC SiHa cells and regulates the apoptosis and DNA damage repair,potentially reversing the EMT process,thereby inhibiting the proliferation and migration of the tumor cells.

Objective:To investigate the protective effect of Dendrobium officinale polysaccharides(DOP)on intestinal mucosal barrier damage,and to elucidate the possible mechanism.Methods:Ten female C57BL/6 mice,aged 5 months,were selected as young group;twenty femal C57BL/6 mice,aged 15 months,were randomly divided into aged group and DOP treatment group(200 mg·kg-1,DOP group),with 10 mice in each group.The mice in DOP group were administrated with DOP by gavage.The body mass,food intakes and hanging time of the mice in various groups were detected.HE staining was used to observe the pathomorphology of intestinal and spleen tissues of the mice in various groups.Immunohistochemical staining was used to detect the expressions of intestinal atresin 1(ZO-1)and Mucin 2(MUC2)in intestinal tissue of the mice in various groups.The intestinal baterial metabolite medium(IBMM)were prepared to intervene the Caenorhabditis elegans(C.elegans),and the C.elegans were randomly divided into Young-IBMM group,Aged-IBMM group,and DOP-IBMM group.Immuno-fluorescence method was used to analyze the intestinal lipofuscin accumulation levels on the 1st day and the 12th day of the C.elegans in various groups.Brilliant blue staining was used to assess the intestinal leakage on the 1st day and the 12th day of C.elegans in various groups.The Caco-2 cells were randomly divided into Young-IBMM,Aged-IBMM and DOP-IBMM groups,and Western blotting method was used to detect the expression levels of ZO-1,Occludin,tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),phosphorylated myosin light chain(p-MLC),myosin light chain kinase(MLCK)proteins in the Caco-2 cells in various groups.Results:Compared with young group,the body mass of the mice in aged group was increased(P＜0.05),the amount of food intake was decreased(P＜0.05),and the hanging time was decreased(P＜0.05);compared with aged group,the body mass of the mice in DOP group was significantly decreased(P＜0.01),the amount of food intake was increased(P＜0.05),and the hanging time was significantly extended(P＜0.01).The HE staining results showed that compared with young group,the thickness of intestinal mucosa of the mice in aged group became thinner,the goblet cells were reduced,the intestinal villi were disordered with different lengths,a large amount of hemosiderin was found on the surface of the spleen,the cell components in the red medullary were reduced,and the lymphatic sheath and lymphatic nodes around the intra-white pulp artery remained or almost disappeared;compared with aged group,the thickness of the intestinal mucosa of the mice in DOP group was increased,the goblet cells were increased,the length of the intestinal villi was consistent and neatly arranged,the overall function of the red pulp of the spleen was improved,and the components of the white pulp were increased.The immunohistochemical staining results showed that compared with young group,the expression levels of ZO-1 and MUC2 proteins in intestinal tissue of the mice in aged group were significantly decreased(P＜0.05 or P＜0.001);compared with aged group,the expression levels of ZO-1 and MUC2 proteins in the intestinal tissue of the mice in DOP group were significantly increased(P＜0.05 or P＜0.001).The immuno-fluorescence analysis showed that compared with Young-IBMM group,the intestinal lipofuscin accumulation level of C.elegans in Aged-IBMM group was significantly increased(P＜0.001);compared with Aged-IBMM group,the intestinal lipofuscin accumulation level of C.elegans in DOP-IBMM group was significantly reduced(P＜0.001).The brilliant blue staining showed that compared with Young-IBMM group,the bright blue dye leaked into the whole body of C.elegans from intestinal tissue in Aged-IBMM group,and the intestinal structure became blurred and was difficulted to be observed;compared with Aged-IBMM group,the leakage of bright blue dye of C.elegans in DOP-IBMM was reduced.The Western blotting results showed that compared with Young-IBMM group,the expression levels of TNF-α,IL-6,p-MLC,and MLCK proteins in the Caco-2 cells in Aged-IBMM group were significantly increased(P＜0.01 or P＜0.001),and the expression levels of ZO-1 and Occludin proteins were significantly decreased(P＜0.05 or P＜0.01);compared with Aged-IBMM,the expression levels of TNF-α,IL-6,p-MLC and MLCK proteins in the Caco-2 cells in DOP-IBMM group were significantly decreased(P＜0.01),and the expression levels of ZO-1 and Occludin proteins were significantly increased(P＜0.05 or P＜0.01).Conclusion:DOP has an ameliorating effect on intestinal mucosal barrier damage in the aged mice,and its mechanism may be related to the improvement of intestinal barrier damage by regulating intestinal bacterial metabolites,inhibiting the p-MLC/MLCK signal pathway,restoring the expression of tight junction complexes,and reducing the level of intestinal inflammation.