BACKGROUND:Immune rejections after organ transplantation or serious adverse reactions due to immunosuppressive drugs show a lack of effective treatments and poor therapeutic outcomes. Therefore, we try to find an effective immune suprresion method in combination of the latest immunomodulatory achievements. OBJECTIVE:To construct a lentiviral vector overexpressing indoleamine 2,3-dioxygenase (IDO). METHODS:(1) The IDO gene that was successful y contructed was inserted into lentiviral packaging plasmids GV308 to construct GV308-IDO lentivirus packaging plasmids. (2) The 293T cel s with 80%confluence were co-cultured with 5'LTR and 3'LTR, basic elements of lentiviral packaging auxiliary components, including Psi, cPPT, 3FLAG, TetR, IRES, WRPE, TetIIP, Ubiquitin Promoter, SV40 origin and HIV. RESULTS AND CONCLUSION:Western blot assay showed that in 10 g/L agarose gel electrophoresis, there was a target fragment at Mr 48 000. This value was consistent with the size of IDO protein. RT-PCR results showed visible IDO expression in 293T cel s. These findings suggest that IDO fusion gene has been successful y reorganized in the lentiviral packaging plasmids.

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BACKGROUND:Since the FDA was the first to approve autologous bone marrow stem cel transplantation for treatment of myocardial infarction in 2003, there has a large number of clinical and basic research reports. However, their conclusions are different and stem cel homing is a key point. OBJECTIVE:To explore the homing abilities of different subgroups of mouse bone marrow mesenchymal stem cels in myocardial regeneration. METHODS:After mouse bone marrow mesenchymal stem cels were detected using a mouse cardiac stem cel surface differentiation antigen, four cel subgroups were separated on the basis of CD45 and CD31. The homing abilities of the four subgroups were assayed in a Transwel chamberin vitro. The different cel subgroups were injected into the model mice suffering from myocardial infarction for 48 hours. The mice were sacrificed at 48 hours, 96 hours, and 7 days after injection; the hearts were taken and analyzed through whole-body imaging and fluorescence intensity detection. RESULTS AND CONCLUSION:The SCA-1+/CD45+/CD31+ subgroup exhibited the strongest homing ability. The whole-body imaging indicated that the fluorescence intensity of SCA-1+/CD45+/CD31+ subgroup was higher than that of the other subgroups at 48 hours, 96 hours and 7 days after stem cel injection. The migration rate of SCA-1+/CD45+/CD31+ subgroup was also the highest. These findings indicate that the homing ability of the SCA-1+/CD45+/CD31+ subgroup of mouse bone marrow mesenchymal stem cels exhibit a homing trend to the damaged myocardial tissue.

BACKGROUND: Preliminary study has shown that overexpression of GATA-4-overexpressing bone marrow mesenchymal stem cell (BMSCs) exosomes (BMSCsGATA-4-exosome) can promote BMSCs differentiate into cardiomyocytes, indicating it can repair myocardial infarction. Additionally, high expression of miRNA-673-5p is observed in miRNA-673-5p BMSCsGATA-4-exosome and focal myocardium of myocardial infarction, which involve in cell differentiation, suggesting that miRNA-673-5p may be a key molecular of BMSCsGATA-4-exosome for repairing myocardial infarction. OBJECTIVE: To investigate the molecular regulatory network of BMSCsGATA-4-exosomes that promotes BMSCs differentiation into cardiomyocyte-like cells. METHODS: miR-673-5p-mimic was added to the BMSCs culture system as an experimental group (BMSCsmiR-330-3p-mimic ). BMSCsGATA-4, BMSCsGATA-4-empty vector, BMSCs and BMSCsGATA-4-miR-673-5p-inhibitor groups were set as confounding factor control groups. The exosomes and myocardial cells secreted by each group were co-cultured for 24 hours. The expression levels of myocardium specific molecules α-actin, Desmin, cTnT and Cx43 were detected by immunofluorescence and RT-PCR. The expression levels of the corresponding miRNA-673-5p target genes TSC-1, ERK1/2 and Mef2c were detected through western blot assay based on the prediction results of the microRNA target gene. RESULTS AND CONCLUSION: The BMSCsmiR-673-5p-mimic-exosome+BMSCs culture group had the highest α-actin, Desmin, cTnT and Cx43 levels (P < 0.05), and the lowest TSC-1 expression (P < 0.05). In summary, BMSCsGATA-4-exosome inhibits the expression of TSC-1 via miRNA-673-5p to promote BMSCs differentiation into cardiomyocyte-like cells.

Objective:To analyze and study the difficulties and countermeasures in the implementation of the Qualified Person(QP) system for stem cell clinical research, and share the experience of QP management practice in our hospital in order to promote and improve the construction of the QP management system in medical institutions.Methods:Comprehensive investigations were conducted to summarize and analyze the shortage of talents, unclear qualifications, unclear responsibilities, and lack of assessment standards in the QP system of medical institutions.Results:In view of the difficulties in the implementation of the current QP system, it is suggested to consider a combination of improving the system of laws and regulations, strengthening the top-level design of stem cell research institutions, clarifying the qualification threshold, refining QP responsibilities, continuing training and assessment system, establishing QP support system, etc.Conclusions:Medical institutions are responsible for stem cell clinical research, and the improvement of the QP system can promote the development of the cell industry in China.

Objective:The study aims to analyze the problems faced in the clinical research and management of stem cells, explore the construction of the entire process of stem cells clinical research, and promote the healthy and orderly development of the clinical research of stem cells.Methods:By consulting the literature and retrieval of relevant policies and regulations, this study analyzed the problems faced by the supervision and management department, medical institutions and researchers, this study and discussed the countermeasures for strengthening the management of the entire process of clinical research of stem cells in medical institutions.Results:There were imperfect internal system and poor management process, insufficient quality control of cell products, low quality of project management, and insufficient clinical research consciousness of stem cell clinical research management in medical institutions.Conclusions:Combined with the current management measures, guidance principles and medical institutions, we should improve the internal system of medical institutions, promote the centralized management and informatization construction of projects, strengthen cell quality control in the hospital, cultivate talent echelons and improve academic and ethical review capabilities, actively explore the management model that is suitable for the entire process of stem cell clinical research for medical institutions in China.

Hepatic stellate cells(HSCs)are essential drivers of fibrogenesis.Inducing activated-HSC apoptosis is a promising strategy for treating hepatic fibrosis.18beta-glycyrrhetinic acid(18β-GA)is a natural com-pound that exists widely in herbal medicines,such as Glycyrrhiza uralensis Fisch,which is used for treating multiple liver diseases,especially in Asia.In the present study,we demonstrated that 18β-GA decreased hepatic fibrosis by inducing the apoptosis in activated HSCs.18β-GA inhibited the expression of α-smooth muscle actin and collagen type Ⅰ alpha-1.Using a chemoproteomic approach derived from activity-based protein profiling,together with cellular thermal shift assay and surface plasmon reso-nance,we found that 18β-GA covalently targeted peroxiredoxin 1(PRDX1)and peroxiredoxin 2(PRDX2)proteins via binding to active cysteine residues and thereby inhibited their enzymatic activities.18β-GA induced the elevation of reactive oxygen species(ROS),resulting in the apoptosis of activated HSCs.PRDX1 knockdown also led to ROS-mediated apoptosis in activated HSCs.Collectively,our findings revealed the target proteins and molecular mechanisms of 18β-GA in ameliorating hepatic fibrosis,highlighting the future development of 18β-GA as a novel therapeutic drug for hepatic fibrosis.

The composition of serum is extremely complex,which complicates the discovery of new pharmaco-dynamic biomarkers via serum proteome for disease prediction and diagnosis.Recently,nanoparticles have been reported to efficiently reduce the proportion of high-abundance proteins and enrich low-abundance proteins in serum.Here,we synthesized a silica-coated iron oxide nanoparticle and devel-oped a highly efficient and reproducible protein corona(PC)-based proteomic analysis strategy to improve the range of serum proteomic analysis.We identified 1,070 proteins with a median coefficient of variation of 12.56％using PC-based proteomic analysis,which was twice the number of proteins iden-tified by direct digestion.There were also more biological processes enriched with these proteins.We applied this strategy to identify more pharmacodynamic biomarkers on collagen-induced arthritis(CIA)rat model treated with methotrexate(MTX).The bioinformatic results indicated that 485 differentially expressed proteins(DEPs)were found in CIA rats,of which 323 DEPs recovered to near normal levels after treatment with MTX.This strategy can not only help enhance our understanding of the mechanisms of disease and drug action through serum proteomics studies,but also provide more pharmacodynamic biomarkers for disease prediction,diagnosis,and treatment.

Sepsis is characterized by a severe and life-threatening host immune response to polymicrobial infection accompanied by organ dysfunction.Studies on the therapeutic effect and mechanism of immunomod-ulatory drugs on the sepsis-induced hyperinflammatory or immunosuppression states of various im-mune cells remain limited.This study aimed to investigate the protective effects and underlying mechanism of artesunate(ART)on the splenic microenvironment of cecal ligation and puncture-induced sepsis model mice using single-cell RNA sequencing(scRNA-seq)and experimental validations.The scRNA-seq analysis revealed that ART inhibited the activation of pro-inflammatory macrophages recruited during sepsis.ART could restore neutrophils'chemotaxis and immune function in the septic spleen.It inhibited the activation of T regulatory cells but promoted the cytotoxic function of natural killer cells during sepsis.ART also promoted the differentiation and activity of splenic B cells in mice with sepsis.These results indicated that ART could alleviate the inflammatory and/or immunosuppressive states of various immune cells involved in sepsis to balance the immune homeostasis within the host.Overall,this study provided a comprehensive investigation of the regulatory effect of ART on the splenic microenvironment in sepsis,thus contributing to the application of ART as adjunctive therapy for the clinical treatment of sepsis.

Objective:To investigate the current status of prevention and treatment of esophagogastric variceal bleeding (EVB) in cirrhotic portal hypertension patients in Ningxia region.Methods:The retrospective and descriptive study was conducted. The clinical data of 820 cirrhotic portal hypertension patients who were admitted to 21 medical centers in Niangxia region from January 2018 to December 2020 were collected, including 85 cases in Ningxia Hui Autonomous Region People′s Hospital, 73 cases in the Fifth People′s Hospital of Ningxia Hui Autonomous Region, 59 cases in the Wuzhong People′s Hospital, 52 cases in the Qingtongxia People′s Hospital, 50 cases in the Guyuan People′s Hospital, 47 cases in the Yuanzhou District People′s Hospital of Guyuan City, 47 cases in the Yinchuan Second People′s Hospital, 40 cases in the General Hospital of Ningxia Medical University, 40 cases in the Tongxin People′s Hospital, 35 cases in the Yinchuan First People′s Hospital, 34 cases in the Third People′s Hospital of Ningxia Hui Autonomous Region, 32 cases in the Zhongwei People′s Hospital, 30 cases in the Lingwu People′s Hospital, 30 cases in the Wuzhong New District Hospital, 30 cases in the Yanchi People′s Hospital, 29 cases in the Ningxia Hui Autonomous Region Academy of Traditional Chinese Medicine, 28 cases in the Shizuishan Second People′s Hospital, 25 cases in the Shizuishan First People′s Hospital, 21 cases in the Haiyuan People′s Hospital, 20 cases in the Pengyang People′s Hospital, 13 cases in the Longde People′s Hospital. There were 538 males and 282 females, aged (56±13)years. Observation indicators: (1) clinical charac-teristics of cirrhotic portal hypertension patients; (2) overall prevention and treatment of EVB in cirrhotic portal hypertension patients; (3) prevention and treatment of EVB in cirrhotic portal hypertension patients from different grade hospitals. Measurement data with normal distribution were represented as Mean± SD. Count data were described as absolute numbers, and comparison between groups was analyzed using the chi-square test. Results:(1) Clinical characteristics of cirrhotic portal hypertension patients: of 820 cirrhotic portal hypertension patients, 271 cases were in compensated stage and 549 cases were in decompensated stage. Of the 271 cases in compensated stage, there were 183 maels and 88 females, aged (53±12)years. There were 185 Han people, 85 Hui people and 1 case of other ethic group. The etiological data of liver cirrhosis showed 211 cases of viral hepatitis B, 4 cases of alcoholic liver disease, 8 cases of viral hepatitis C, and 48 cases of other etiology. There were 235 cases of Child-Pugh grade A and 36 cases lack of data. Of the 549 cases in decompensated stage, there were 355 males and 194 females, aged (57±14) years. There were 373 Han people, 174 Hui people and 2 cases of other ethic group. The etiological data of liver cirrhosis showed 392 cases of viral hepatitis B, 33 cases of alcoholic liver disease, 10 cases of viral hepatitis C, and 114 cases of other etiology. There were 80 cases of Child-Pugh grade A, 289 cases of grade B, 170 cases of grade C and 10 cases lack of data. (2) Overall prevention and treatment of EVB in cirrhotic portal hypertension patients: of 271 patients in compensated stage, 38 cases received non-selective β-blocker (NSBB) therapy, 16 cases received endoscopic treatment, 6 cases received interventional therapy. Of 549 patients in decompensated stage, 68 cases received NSBB therapy, 46 cases received endoscopic treatment, 28 cases received interventional therapy. (3) Prevention and treatment of EVB in cirrhotic portal hypertension patients from different grade hospitals: of 271 patients in compensated stage, 181 cases came from tertiary hospitals, of which 28 cases received NSBB therapy, 15 cases received endoscopic treatment, 6 cases received interventional therapy. Ninety cases came from secondary hospitals, of which 10 cases received NSBB therapy, 1 cases received endoscopic treatment. There was no significant difference in NSBB for prevention of EVB between tertiary and secondary hospitals ( χ2=0.947, P>0.05), while there was a significant difference in endoscopic treatment for prevention of EVB between tertiary and secondary hospitals ( χ2=5.572, P<0.05). Of 549 patients in decompensated stage, 309 cases came from tertiary hospitals, of which 22 cases received NSBB therapy, 29 cases received endoscopic treatment, 22 cases received interventional therapy. Two hundreds and fourty cases came from secondary hospitals, of which 46 cases received NSBB therapy, 17 cases received endoscopic treatment, 6 cases received interven-tional therapy. There were significant differences in NSBB and interventional therapy for prevention of EVB between tertiary and secondary hospitals ( χ2=18.065, 5.956, P<0.05). Conclusions:The proportion of receiving EUB prevention in cirrhotic portal hypertension in Ningxia is relatively low. For patients with compensated liver cirrhosis, the proportion of NSBB therapy and endoscopic treatment in the secondary hospitals was lower than that in tertiary hospitals. For patients with decompensated liver cirrhosis, the proportion of interventional treatment in secondary hospitals is lower than that of tertiary hospitals, but the proportion of NSBB in secondary hospitals taking is higher than that of tertiary hospitals.