Objective To explore the related functional mechanism of Xihuang pill containing serum inter-vention in breast cancer cells based on microRNA(miR)21-5p targeting FAM13A gene.Methods Bioinfor-matics websites was used to predict potential miRNAs of FAM13A gene,double luciferase reporter experi-ments were conducted to verify the binding site relationship between FAM13A and predicted miRNAs.The Xihuang pill containing serum was prepared,and human breast cancer MDA-MB-231 cells were cultured.The proliferation of MDA-MB-231 cells was interfered by the Xihuang pill containing serum with different dilution ratios by CCK-8 test,and the best dilution ratio concentration of Xihuang pill containing serum to inhibit the proliferation of breast cancer cells was selected.Real time fluorescence quantitative PCR(RT-qPCR)was ap-plied to detect the relative expression levels of FAM13A mRNA,as well as the relative expression levels of miR21-5p,in MDA-MB-231 cells after intervention with Xihuang pill containing serum.Cell proliferation(Edu)assay and cell apoptosis detection(TUNEL)assay were used to detect the effects of Xihuang pill con-taining serum intervention on cell proliferation and apoptosis function in MDA-MB-231 cells.The siRNA lentiviral transfection on MDA-MB-231 cells was performed to knock down the FAM13A gene,and Edu assay and TUNEL assay were used to detect changes in proliferation and apoptosis ability of MDA-MB-231 cells af-ter lentiviral transfection.The expression level of miR21-5p in MDA-MB-231 cells after FAM13A gene knock-out was detected by RT-qPCR technology.Results Target Scan online website predicted the potential miR-21-5p binding sequence in the 3'UTR of FAM13A mRNA,and dual luciferase reporter assay confirmed the in-teraction between miR-21-5p and FAM13A.After intervention of MDA-MB-231 cells with Xihuang pill drug containing serum,RT-qPCR results showed that compared with the control group(NC group),the Xihuang pill drug containing serum group(XHW group)downregulated the expression levels of FAM13A mRNA(P＜0.05),and upregulated the expression level of miR21-5p(P＜0.05).Compared with the NC group,the XWH group showed reduced cell proliferation ability and promoted cell apoptosis.(P＜0.05).After silencing the FAM13A gene in MDA-MB-231 cells,compared with the control group(shCtrl group),the shFAM13A group showed a significant decrease in cell proliferation ability and promoted cell apoptosis.The RT-qPCR re-sults showed that compared with the shCtrl group,the expression level of miR21-5p was significantly upregu-lated in the shFAM13A group(P＜0.05).Conclusion Xihuang pill could participate in the anti-tumor treat-ment of breast cancer by regulating miR21-5p to affect the expression level of FAM13A gene.

Objective:To investigate the effects of gelatin methacrylate anhydride (GelMA) hydrogel loaded with small extracellular vesicles derived from human umbilical cord mesenchymal stem cells (hUCMSCs-sEVs) in the treatment of full-thickness skin defect wounds in mice.Methods:This study was an experimental study. hUCMSCs-sEVs were extracted by ultracentrifugation, their morphology was observed through transmission electron microscope, and the expression of CD9, CD63, tumor susceptibility gene 101 (TSG101), and calnexin was detected by Western blotting. The human umbilical vein endothelial cells (HUVECs), the 3 rd and 4 th passages of human epidermal keratinocytes (HEKs) and human dermal fibroblasts (HDFs) were all divided into blank control group (routinely cultured) and hUCMSC-sEV group (cultured with the cell supernatant containing hUCMSCs-sEVs). The cell scratch test was performed and the cell migration rates at 6, 12, and 24 h after scratching were calculated, the cell Transwell assay was performed and the number of migration cells at 12 h after culture was calculated, and the proportion of proliferating cells was detected by 5-acetylidene-2'-deoxyuridine and Hoechst staining at 24 h after culture, with sample numbers being all 3. The simple GelMA hydrogel and the GelMA hydrogel loaded with hUCMSCs-sEVs (hereinafter referred to as hUCMSC-sEV/GelMA hydrogel) were prepared. Then the micromorphology of 2 kinds of hydrogels was observed under scanning electron microscope, the distribution of hUCMSCs-sEVs was observed by laser scanning confocal microscope, and the cumulative release rates of hUCMSCs-sEVs at 0 (immediately), 2, 4, 6, 8, 10, and 12 d after soaking hUCMSC-sEV/GelMA hydrogel in phosphate buffer solution (PBS) were measured and calculated by protein colorimetric quantification ( n=3). Twenty-four 6-week-old male C57BL/6J mice were divided into PBS group, hUCMSC-sEV alone group, GelMA hydrogel alone group, and hUCMSC-sEV/GelMA hydrogel group according to the random number table, with 6 mice in each group, and after the full-thickness skin defect wounds on the back of mice in each group were produced, the wounds were performed with PBS injection, hUCMSC-sEV suspenson injection, simple GelMA coverage, and hUCMSC-sEV/GelMA hydrogel coverage, respectively. Wound healing was observed on post injury day (PID) 0 (immediately), 4, 8, and 12, and the wound healing rates on PID 4, 8, and 12 were calculated, and the wound tissue was collected on PID 12 for hematoxylin-eosin staining to observe the structure of new tissue, with sample numbers being both 6. Results:The extracted hUCMSCs-sEVs showed a cup-shaped structure and expressed CD9, CD63, and TSG101, but barely expressed calnexin. At 6, 12, and 24 h after scratching, the migration rates of HEKs (with t values of 25.94, 20.98, and 20.04, respectively), HDFs (with t values of 3.18, 5.68, and 4.28, respectively), and HUVECs (with t values of 4.32, 19.33, and 4.00, respectively) in hUCMSC-sEV group were significantly higher than those in blank control group ( P<0.05). At 12 h after culture, the numbers of migrated HEKs, HDFs, and HUVECs in hUCMSC-sEV group were 550 ±23, 235 ±9, and 856 ±35, respectively, which were significantly higher than 188 ±14, 97 ±6, and 370 ±32 in blank control group (with t values of 22.95, 23.13, and 17.84, respectively , P<0.05). At 24 h after culture, the proportions of proliferating cells of HEKs, HDFs, and HUVECs in hUCMSC-sEV group were significantly higher than those in blank control group (with t values of 22.00, 13.82, and 32.32, respectively, P<0.05). The inside of simple GelMA hydrogel showed a loose and porous sponge-like structure, and hUCMSCs-sEVs was not observed in it. The hUCMSC-sEV/GelMA hydrogel had the same sponge-like structure, and hUCMSCs-sEVs were uniformly distributed in clumps. The cumulative release rate curve of hUCMSCs-sEVs from hUCMSC-sEV/GelMA hydrogel tended to plateau at 2 d after soaking, and the cumulative release rate of hUCMSCs-sEVs was (59.2±1.8)% at 12 d after soaking. From PID 0 to 12, the wound areas of mice in the 4 groups gradually decreased. On PID 4, 8, and 12, the wound healing rates of mice in hUCMSC-sEV/GelMA hydrogel group were significantly higher than those in the other 3 groups ( P<0.05); the wound healing rates of mice in GelMA hydrogel alone group and hUCMSC-sEV alone group were significantly higher than those in PBS group ( P<0.05). On PID 8 and 12, the wound healing rates of mice in hUCMSC-sEV alone group were significantly higher than those in GelMA hydrogel alone group ( P<0.05). On PID 12, the wounds of mice in hUCMSC-sEV/GelMA hydrogel group showed the best wound epithelization, loose and orderly arrangement of dermal collagen, and the least number of inflammatory cells, while the dense arrangement of dermal collagen and varying degrees of inflammatory cell infiltration were observed in the wounds of mice in the other 3 groups. Conclusions:hUCMSCs-sEVs can promote the migration and proliferation of HEKs, HDFs, and HUVECs which are related to skin wound healing, and slowly release in GelMA hydrogel. The hUCMSC-sEV/GelMA hydrogel as a wound dressing can significantly improve the healing speed of full-thickness skin defect wounds in mice.

Objective:To investigate the genetic safety of allogeneic bone marrow mesenchymal stem cells (BMSCs) transplantation in traumatic brain injury (TBI).Methods:(1) In vivo experiment: BMSCs from male SD rats were isolated and cultured. Moderate TBI models were prepared by implanting and fixing micro-drug injection cannula into the left ventricle of 12 female SD rats, and 3 d after that, striking the right cerebral cortex of the rats with pneumatic precision percussion device was performed. Four h, and 3, 6, 9, and 12 d after modeling, TBI rats were given a single/multiple BMSCs infusion (2.5×10 5/time, total volume 10 μL) by cannula; 48 and 72 h, and 10 and 14 d after modeling, brain tissues of TBI rats (3 at each time point) were prepared into paraffin specimens. Immunofluorescent staining was used to detect the microglia activation, and RNAscope ? technology was used to detect the co-localization of astrocytes, neurons, microglia and transplanted BMSCs to observe whether the allogeneic BMSCs were integrated with the host brain cells after transplantation into TBI host. (2) In vitro experiment: the frozen and revived microglial cell line BV2 was transfected with green fluorescent protein (GFP)-positive lentiviral particles, and then, BMSCs prelabeled with pHrodo RED probe and BV2 cells pretreated with lipopolysaccharide were co-cultured in a certain ratio (BV2:BMSCs=1:1, 1:2, 2:1); after 36 and 72 h of co-culture, the phagocytosis between the 2 kinds of cells was observed under confocal fluorescence inverted microscope to observe the specific action forms of microglia on BMSCs. Results:(1) In vivo experiment: 48 and 72 h, and 10 and 14 d after modeling, no colocalization of transplanted BMSCs with astrocytes or neurons was found in paraffin sections of brain tissue in TBI rats; however, 10 and 14 d after modeling, microglia in TBI rats were obviously activated and migrated to the left lateral ventricle and choroid plexus, and co-localization of microglia with transplanted BMSCs was observed. (2) In vitro experiment: phagocytosis occurred after co-culture of BV2 cells at different proportions with BMSCs for 36 and 72 h. Conclusion:After transplantation, allogeneic BMSCs do not integrate with astrocytes or neurons of the TBI host, but they could be phagocytosed by microglia, indicating that allogeneic BMSCs transplantation for TBI is genetically safe.

Respiratory viral infections are an important public health problem worldwide, with complex mechanisms of infection, and the key to infection lies in the specific binding between respiratory viruses and receptors. This article provides an overview of the progress in the study of receptors for respiratory viruses, such as coronavirus and influenza virus (IV), with a focus on the binding sites of receptors such as angiotensin-converting enzyme 2 (ACE2) and sialic acid (SA) to respiratory viruses and the role of receptor diversity in respiratory viral infections. An in-depth study of the binding sites between viruses and receptors will help to understand the molecular mechanism of respiratory viral infections and provide a theoretical basis for disease prevention and control and the development of new therapeutic targets.

Respiratory viral infections are an important public health problem worldwide, with complex mechanisms of infection, and the key to infection lies in the specific binding between respiratory viruses and receptors. This article provides an overview of the progress in the study of receptors for respiratory viruses, such as coronavirus and influenza virus (IV), with a focus on the binding sites of receptors such as angiotensin-converting enzyme 2 (ACE2) and sialic acid (SA) to respiratory viruses and the role of receptor diversity in respiratory viral infections. An in-depth study of the binding sites between viruses and receptors will help to understand the molecular mechanism of respiratory viral infections and provide a theoretical basis for disease prevention and control and the development of new therapeutic targets.

At present, sexual route is the main transmission route of AIDS in China, and its role in the process of AIDS epidemic has been evolving. Various modes of transmission in sexual transmission and the prevention and control strategies adopted by China have also been changing. This paper mainly summarizes the epidemic characteristics of different periods and different modes of transmission of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) in China in recent years. The strategies of prevention and control were described from seven aspects, including health education, promotion of condom use, expanded testing, HIV/AIDS antiviral treatment, pre-exposure prophylactic medication, post-exposure prophylactic medication, social organization participation and sexually transmitted diseases prevention and control. Only when innovative and targeted measures according to the evolution of the HIV/AIDS epidemic and various specific methods are complemented by each other, can the transmission of HIV/AIDS through sexual route be effectively prevented and controlled.