Mesenchymal stem cells alleviate mouse liver fibrosis by inhibiting pathogenic function of intrahepatic B cells.

BACKGROUND AND AIMS: The immunomodulatory characteristics of mesenchymal stem cells (MSCs) make them a promising therapeutic approach for liver fibrosis (LF). Here, we postulated that MSCs could potentially suppress the pro-fibrotic activity of intrahepatic B cells, thereby inhibiting LF progression. APPROACH AND RESULTS: Administration of MSCs significantly ameliorated LF as indicated by reduced myofibroblast activation, collagen deposition, and inflammation. The treatment efficacy of MSCs can be attributed to decreased infiltration, activation, and pro-inflammatory cytokine production of intrahepatic B cells. Single-cell RNA sequencing revealed a distinct intrahepatic B cell atlas, and a subtype of naive B cells (B-II) was identified, which were markedly abundant in fibrotic liver, displaying mature features with elevated expression of several proliferative and inflammatory genes. Transcriptional profiling of total B cells revealed that intrahepatic B cells displayed activation, proliferation, and pro-inflammatory gene profile during LF. Fibrosis was attenuated in mice ablated with B cells (µMT) or in vivo treatment with anti-CD20. Moreover, fibrosis was recapitulated in µMT after adoptive transfer of B cells, which in turn could be rescued by MSC injection, validating the pathogenic function of B cells and the efficacy of MSCs on B cell-promoted LF progression. Mechanistically, MSCs could inhibit the proliferation and cytokine production of intrahepatic B cells through exosomes, regulating the Mitogen-activated protein kinase and Nuclear factor kappa B signaling pathways. CONCLUSIONS: Intrahepatic B cells serve as a target of MSCs, play an important role in the process of MSC-induced amelioration of LF, and may provide new clues for revealing the novel mechanisms of MSC action.

Infectious hepatitis E virus excreted into the vagina.

Hepatitis E virus (HEV) persists in the male genital tract that associates with infertility. However, the presence of HEV in the female genital tract is unreported. Vaginal secretions, cervical smears, and cervix uteri were collected to explore the presence of HEV in the female genital tract. HEV RNA and/or antigens were detected in the vaginal secretions, cervical smears, and the cervix uteri of women. The infectivity of HEV excreted into vaginal secretions was further validated in vitro. In addition, HEV replicates in the female genital tract were identified in HEV-infected animal models by vaginal injection or vaginal mucosal infection to imitate sexual transmission. Serious genital tract damage and inflammatory responses with significantly elevated mucosal innate immunity were observed in women or animals with HEV vaginal infection. Results demonstrated HEV replicates in the female genital tract and causes serious histopathological damage and inflammatory responses.

MSCs alleviate LPS-induced acute lung injury by inhibiting the proinflammatory function of macrophages in mouse lung organoid-macrophage model.

Acute lung injury (ALI) is an inflammatory disease associated with alveolar injury, subsequent macrophage activation, inflammatory cell infiltration, and cytokine production. Mesenchymal stem cells (MSCs) are beneficial for application in the treatment of inflammatory diseases due to their immunomodulatory effects. However, the mechanisms of regulatory effects by MSCs on macrophages in ALI need more in-depth study. Lung tissues were collected from mice for mouse lung organoid construction. Alveolar macrophages (AMs) derived from bronchoalveolar lavage and interstitial macrophages (IMs) derived from lung tissue were co-cultured, with novel matrigel-spreading lung organoids to construct an in vitro model of lung organoids-immune cells. Mouse compact bone-derived MSCs were co-cultured with organoids-macrophages to confirm their therapeutic effect on acute lung injury. Changes in transcriptome expression profile were analyzed by RNA sequencing. Well-established lung organoids expressed various lung cell type-specific markers. Lung organoids grown on spreading matrigel had the property of functional cells growing outside the lumen. Lipopolysaccharide (LPS)-induced injury promoted macrophage chemotaxis toward lung organoids and enhanced the expression of inflammation-associated genes in inflammation-injured lung organoids-macrophages compared with controls. Treatment with MSCs inhibited the injury progress and reduced the levels of inflammatory components. Furthermore, through the nuclear factor-κB pathway, MSC treatment inhibited inflammatory and phenotypic transformation of AMs and modulated the antigen-presenting function of IMs, thereby affecting the inflammatory phenotype of lung organoids. Lung organoids grown by spreading matrigel facilitate the reception of external stimuli and the construction of in vitro models containing immune cells, which is a potential novel model for disease research. MSCs exert protective effects against lung injury by regulating different functions of AMs and IMs in the lung, indicating a potential mechanism for therapeutic intervention.

A novel HIF2A mutation causes dyslipidemia and promotes hepatic lipid accumulation.

Hypoxia-inducible factor-2α (HIF-2α) is a transcription factor responsible for regulating genes related to angiogenesis and metabolism. This study aims to explore the effect of a previously unreported mutation c.C2473T (p.R825S) in the C-terminal transactivation domain (CTAD) of HIF-2α that we detected in tissue of patients with liver disease. We sequenced available liver and matched blood samples obtained during partial liver resection or liver transplantation performed for clinical indications including hepatocellular carcinoma and liver failure. In tandem, we constructed cell lines and a transgenic mouse model bearing the corresponding identified mutation in HIF-2α from which we extracted primary hepatocytes. Lipid accumulation was evaluated in these cells and liver tissue from the mouse model using Oil Red O staining and biochemical measurements. We identified a mutation in the CTAD of HIF-2α (c.C2473T; p.R825S) in 5 of 356 liver samples obtained from patients with hepatopathy and dyslipidemia. We found that introduction of this mutation into the mouse model led to an elevated triglyceride level, lipid droplet accumulation in liver of the mutant mice and in their extracted primary hepatocytes, and increased transcription of genes related to hepatic fatty acid transport and synthesis in the mutant compared to the control groups. In mutant mice and cells, the protein levels of nuclear HIF-2α and its target perilipin-2 (PLIN2), a lipid droplet-related gene, were also elevated. Decreased lipophagy was observed in mutant groups. Our study defines a subpopulation of dyslipidemia that is caused by this HIF-2α mutation. This may have implications for personalized treatment.

Impact of hepatitis B surface antigen positive grafts on liver transplantation in patients with benign and malignant liver disease.

Hepatitis B surface antigen (HBsAg) persists after liver transplantation in almost all patients receiving HBsAg-positive grafts. Chronic hepatitis B virus (HBV) infection is one of the main causes of hepatocellular carcinoma (HCC). We aimed to investigate possible interactions between HBsAg-positive donors, HCC, HBV-related transplant indication, and long-term outcomes. This retrospective study enrolled 1176 patients from two centers between January 2015 and May 2019, of which 135 (11.5%) were HBsAg-positive and 1041 (88.5%) were HBsAg-negative donors. Cox regression models were fitted to study the association between variables and patient and graft survival. In univariate and multivariate analyses, the donor HBsAg status was not significantly associated with patient and graft survival in the entire cohort, but there was a significant interaction between HBsAg-positive donors and HCC, independent of HBV-related transplant indication. The cumulative incidence of patient and graft survival was significantly lower in the subgroup of HCC recipients receiving HBsAg-positive grafts, but no significant difference was found in recipients with benign liver disease. In a subgroup analysis of HCC recipients, HBsAg-positive donors were significantly associated with an increased risk of HCC recurrence (hazard ratio: 1.73; 95% confidence interval: 1.20-2.48; p = 0.003) and similar results were obtained after propensity score matching analysis. We showed excellent outcomes of using HBsAg-positive grafts in patients with benign liver disease, regardless of HBV-related transplant indications. However, positive grafts should be used with caution in recipients with HCC, which are associated with an increased risk of HCC recurrence.

Gut microbiota dysbiosis associated with plasma levels of Interferon-γ and viral load in patients with acute hepatitis E infection.

Few studies have focused on the effect of hepatitis E virus (HEV) infection on gut microbiota. To explore the relationship between changes in gut microbiota and inflammatory factors and viral load, we conducted a comparative study of 33 patients with acute hepatitis E (AHE) patients and 25 healthy controls (HCs) using high-throughput 16S ribosomal ribonucleic acid gene sequencing. Shannon and Simpson's indices showed no significant differences in bacterial diversity between the AHE and HCs groups. Proteobacteria, Gammaproteobacteria, and Enterobacteriaceae were most abundant in the AHE group, which contributed to the difference between the gut microbiota of the AHE and HCs groups, and the same difference between the HEV-RNA-positive and HEV-RNA-negative groups. Functional prediction analysis showed that ribosome, purine metabolism, and two-component system were the top three pathways. Compared with the AHE group with normal interferon (IFN)-γ, Proteobacteria, Gammaproteobacteria, Xanthomonadaceae, and Enterobacteriaceae were more abundant in the high-IFN-γ group. The abundance of Gammaproteobacteria was positively correlated with the level of serum alanine transaminase and total bilirubin. The abundance of Gammaproteobacteria could discriminate AHE patients from HCs, and could better predict the severity of AHE patients. We believe that our findings will contribute toward a novel treatment strategy for AHE.

Dynamic changes of serum metabolites associated with infection and severity of patients with acute hepatitis E infection.

Dynamic changes in metabolites may affect liver disease progression, and provide new methods for predicting liver damage. We used ultra-performance liquid chromatography-mass spectroscopy to assess serum metabolites in healthy controls (HC), and patients with acute hepatitis E (AHE) or hepatitis E virus acute liver failure (HEV-ALF). The principal component analysis, partial least squares discriminant analysis, and discriminant analysis of orthogonal projections to latent structures models illustrated significant differences in the metabolite components between AHE patients and HCs, or between HEV-ALF and AHE patients. In pathway enrichment analysis, we further identified two altered pathways, including linoleic acid metabolism and phenylalanine, tyrosine, and tryptophan biosynthesis, when comparing AHE patients with HCs. Linoleic acid metabolism and porphyrin and chlorophyll metabolism pathways were significantly different in HEV-ALF when compared with AHE patients. The discriminative performances of differential metabolites showed that taurocholic acid, glycocholic acid, glycochenodeoxycholate-3-sulfate, and docosahexaenoic acid could be used to distinguish HEV-ALF from AHE patients. The serum levels of glycocholic acid, taurocholic acid, deoxycholic acid glycine conjugate, and docosahexaenoic acid were associated with the prognosis of HEV-ALF patients. Dynamic changes in serum metabolites were associated with AHE infection and severity. The identified metabolites can be used to diagnose and predict the prognosis of HEV-ALF.

Identification of alpha-enolase as a potential immunogenic molecule during allogeneic transplantation of human adipose-derived mesenchymal stromal cells.

BACKGROUND AIMS: Given their low immunogenicity, immunoregulatory effects and multiple differentiation capacity, mesenchymal stromal cells (MSCs) have the potential to be used for "off-the-shelf" cell therapy to treat various diseases. However, the allorejection of MSCs indicates that they are not fully immune-privileged. In this study, the authors investigated the immunogenicity of human adipose-derived MSCs (Ad-MSCs) and identified potential immunogenic molecules. METHODS: To evaluate the immunogenicity of human Ad-MSCs in vivo, cells were transplanted into humanized mice (hu-mice), then T-cell infiltration and clearance of human Ad-MSCs were observed by immunofluorescence and bioluminescence imaging. One-way mixed lymphocyte reaction and flow cytometry were performed to evaluate the immunogenicity of human Ad-MSCs in vitro. High-throughput T-cell receptor (TCR) repertoire sequencing and mass spectrometry were applied to identified potential immunogenic molecules. RESULTS: The authors observed that allogeneic Ad-MSCs recruited human T cells and caused faster clearance in hu-mice than non-humanized NOD.Cg-Prkdcscid IL2rgtm1Wjl/SzJ (NSG) mice. The proliferation and activation of T cells were significantly enhanced during in vitro co-culture with human Ad-MSCs. In addition, the level of HLA-II expression on human Ad-MSCs was dramatically increased after co-culture with human peripheral blood mononuclear cells (PBMCs). High-throughput sequencing was applied to analyze the TCR repertoire of the Ad-MSC-recruited T cells to identify dominant TCR CDR3 sequences. Using synthesized TCR CDR3 peptides, the authors identified several potential immunogenic candidates, including alpha-enolase (ENO1). The ENO1 expression level of Ad-MSCs significantly increased after co-culture with PBMCs, whereas ENO1 inhibitor (ENOblock) treatment decreased the expression level of ENO1 and Ad-MSC-induced proliferation of T cells. CONCLUSIONS: The authors' findings improve the understanding of the immunogenicity of human Ad-MSCs and provide a theoretical basis for the safe clinical application of allogeneic MSC therapy.

Mesenchymal stem cell treatment restores liver macrophages homeostasis to alleviate mouse acute liver injury revealed by single-cell analysis.

Acute liver injury (ALI) is characterized by massive hepatocyte necrosis and subsequent recruitment of myeloid cells to liver. Mesenchymal stem cells (MSCs) have therapeutic potential for ALI through their immunoregulation on macrophages, but the mechanism is not completely clear due to the heterogeneity and controversy of liver macrophages. Here, we detected the survival rate, biochemical indexes, histopathology, and inflammatory chemokine levels to assess the efficacy of MSC treatment on CCl4-induced ALI of C57BL/6 mice. Furthermore, flow cytometry and single-cell RNA sequencing (scRNA-Seq) were used to precisely distinguish macrophage populations and reveal the immunoregulation of MSCs. MSC treatment could effectively alleviate ALI and mitigate the recruitment of mononuclear phagocytes. Flow cytometry and scRNA-Seq analyses collectively indicated that there were monocytes with high Ly6C expression and heterogeneous monocyte-derived macrophages (MoMF) with low Ly6C expression in liver. Ly6Chi pro-inflammatory monocytes and Ly6Clo MoMF with powerful phagocytosis dominated during the acute injury period. MSC treatment promoted the transition from Ly6Chi to Ly6Clo population, inhibit the proinflammatory function of monocytes and promote the lysosomal function of MoMF. Furthermore, MSCs attenuated the recruitment of neutrophils by reducing the expression of CXCL2 of MoMF. MoMF with high expression of arginase 1 appeared during the recovery period, and MSCs could increase their expression of arginase 1, which may promote liver repair. To sum up, we demonstrated the characteristics of distinct MoMF during different periods of ALI and revealed their functional changes after MSC treatment, providing immunotherapeutic targets for MSC treatment of ALI.

The aryl hydrocarbon receptor ligand ITE inhibits cell proliferation and migration and enhances sensitivity to drug-resistance in hepatocellular carcinoma.

Aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, is considered as a crucial gene during tumor formation and progress. Among various ligands, 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) has been evaluated to share a broad spectrum of biological activities. However, the specific effects and potential mechanisms of ITE against hepatocellular carcinoma remain unclear. Here we explored whether ITE exerted antitumor activity against hepatocellular carcinoma (HCC) cells and its potential mechanisms in vitro and in vivo. We found that ITE could markedly inhibit proliferation of HCCLM3 and SMMC-7721 cells and induce G0/G1 arrest and apoptosis with alterations of expressions of the related proteins. Also, ITE could prohibit the process of migration and invasion evaluated by transwell assay. Moreover, ITE exhibited remarkable capability to repress the growth of HCCLM3-SR cells and induce apoptosis in contrast to sorafenib. Additionally, ITE also showed potent antitumor activity against the HCCLM3 xenograft by prohibiting tumor growth without any toxicity to mice. Mechanistically, AHR activation by ITE was attributed to inhibition of HCC cells as AHR knockdown would abolish ITE-induced suppression in HCC cells, and overexpression of AHR would potentiate antitumor activity regulated by ITE. Our data suggested that ITE manifested a marked antitumor effect against HCC cells both in vitro and in vivo via AHR activation mainly through inducing G1/G0 arrest and apoptosis and inhibiting the process of migration and invasion. Furthermore, we also found the PI3K/AKT pathway was involved in sorafenib-induced resistance and ITE could restore sensitivity by suppressing the PI3K/AKT pathway. Collectively, our study revealed that ITE would be a promising therapeutic agent to deal with HCC and an alternative for drug-resistant HCC.

Epidemiological and clinical characteristics of 70 cases of coronavirus disease and concomitant hepatitis B virus infection: A multicentre descriptive study.

The interaction between existing chronic liver diseases caused by hepatitis B virus (HBV) infection and COVID-19 has not been studied. We analysed 70 COVID-19 cases combined with HBV infection (CHI) to determine the epidemiological, clinical characteristics, treatment and outcome. We investigated clinical presentation, imaging and laboratory parameters of COVID-19 patients of seven hospitals from Jan 20 to March 20, 2020. Multivariate analysis was used to analyse risk factors for progression of patients with COVID-19 combined with HBV infection. Compared with COVID-19 without HBV infection (WHI) group, patients with dual infection had a higher proportion of severe/critically ill disease (32.86% vs. 15.27%, P = .000), higher levels of alanine aminotransferase (ALT), aspartate transaminase (AST) and activated partial thromboplastin (APTT) [50(28-69)vs 21(14-30), P = .000; 40(25-54) vs 23(18-30), P = .000; 34.0(27.2-38.7) vs 37.2(31.1-41.4), P = .031]. The utilization rates of Arbidol and immunoglobulin were significantly higher than those in the co-infected group [48.57% vs. 35.64%, P < .05; 21.43% vs. 8.18%, P < .001], while the utilization rate of chloroquine phosphate was lower (1.43% vs 14.00%, P < .05) in the co-infected patients group. Age and c-reactive protein (CRP) level were independent risk factors for recovery of patients with COVID-19 combined with HBV infection. The original characteristics of COVID-19 cases combined with HBV infection were higher rate of liver injury, coagulation disorders, severe/critical tendency and increased susceptibility. The elderly and patients with higher level of CRP were more likely to experience a severe outcome of COVID-19.

Interferon-α-2b aerosol inhalation is associated with improved clinical outcomes in patients with coronavirus disease-2019.

AIMS: Type 1 interferon (IFN) is used to treat patients with coronavirus disease-2019 (COVID-19) but robust supporting evidence is lacking. We investigated the association between IFN-α-2b and the clinical outcomes of patients with COVID-19. METHODS: A total of 1401 patients were enrolled, with 852 (60.8%) patients receiving 5 000 000 U of IFN-α-2b via aerosol inhalation twice daily. The primary outcome was a composite measure consisting of mechanical ventilation, intensive care unit (ICU) admission and death. A subgroup analysis was performed to investigate the impact of the IFN-α-2b initiation schedule on symptom onset. RESULTS: The risk probability for crude endpoints was lower in the IFN-α-2b group (3.8%) than in the non-IFN-α-2b group (9.3%, P < .001). After adjusting the confounding factors, IFN-α-2b therapy achieved a reduction of 64% in occurrence of endpoint events (hazard ratio, 0.36; 95% confidence interval [CI], 0.21-0.62). In the subgroup analysis, compared with patients who received IFN-α-2b treatment 0-2 days after symptom onset, the hazard ratio for endpoints was 2.2 (95% CI, 0.43-11.13) in patients who received the therapy 3-5 days after symptom onset, 5.89 (95% CI, 0.99-35.05) in patients who received the therapy 6-8 days after symptom onset, and remained at a high level thereafter. CONCLUSIONS: IFN-α-2b aerosol inhalation therapy may be associated with improved clinical outcomes in patients with COVID-19, and delayed IFN-α-2b intervention was associated with increased probabilities of risk events. Further randomized clinical trials are needed to validate the preliminary findings of this study.

Transplantation of Human Mesenchymal Stem-Cell-Derived Exosomes Immobilized in an Adhesive Hydrogel for Effective Treatment of Spinal Cord Injury.

Spinal cord injury is among the most fatal diseases. The complicated inhibitory microenvironment requires comprehensive mitigation. Exosomes derived from mesenchymal stem cells (MSCs) are natural biocarriers of cell paracrine secretions that bear the functions of microenvironment regulation. However, the effective retention, release, and integration of exosomes into the injured spinal cord tissue are poorly defined. Herein, an innovative implantation strategy is established using human MSC-derived exosomes immobilized in a peptide-modified adhesive hydrogel (Exo-pGel). Unlike systemic admistration of exosomes, topical transplantation of the Exo-pGel provides an exosome-encapsulated extracellular matrix to the injured nerve tissue, thereby inducing effecient comprehensive mitigation of the SCI microenvironment. The implanted exosomes exhibit efficient retention and sustained release in the host nerve tissues. The Exo-pGel elicits significant nerve recovery and urinary tissue preservation by effectively mitigating inflammation and oxidation. The Exo-pGel therapy presents a promising strategy for effective treatment of central nervous system diseases based on exosome implantation.

Efficacy and safety of combination PD-1/PD-L1 checkpoint inhibitors for malignant solid tumours: A systematic review.

Treatment of multiple malignant solid tumours with programmed death (PD)-1/PD ligand (PD-L) 1 inhibitors has been reported. However, the efficacy and immune adverse effects of combination therapies are controversial. This meta-analysis was performed with PubMed, Web of Science, Medline, EMBASE and Cochrane Library from their inception until January 2020. Random-effect model was adopted because of relatively high heterogeneity. We also calculated hazard ratio (HR) of progression-free survival (PFS), overall survival (OS) and risk ratio (RR) of adverse events (AEs), the incidence of grade 3-5 AEs by tumour subgroup, therapeutic schedules and therapy lines. Nineteen articles were selected using the search strategy for meta-analysis. Combined PD-1/PD-L1 inhibitors prolonged OS and PFS (HR 0.72, P < 0.001) and (HR 0.66, P < 0.001). In addition, incidence of all-grade and grade 3-5 AEs was not significant in the two subgroup analyses (HR 1.01, P = 0.31) and (HR 1.10, P = 0.07), respectively. Our meta-analysis indicated that combination therapy with PD-1/PD-L1 inhibitors had greater clinical benefits and adverse events were not increased significantly.

Molecular mechanism underlying the difference in proliferation between placenta-derived and umbilical cord-derived mesenchymal stem cells.

The placenta and umbilical cord are pre-eminent candidate sources of mesenchymal stem cells (MSCs). However, placenta-derived MSCs (P-MSCs) showed greater proliferation capacity than umbilical cord-derived MSCs (UC-MSCs) in our study. We investigated the drivers of this proliferation difference and elucidated the mechanisms of proliferation regulation. Proteomic profiling and Gene Ontology (GO) functional enrichment were conducted to identify candidate proteins that may influence proliferation. Using lentiviral or small interfering RNA infection, we established overexpression and knockdown models and observed changes in cell proliferation to examine whether a relationship exists between the candidate proteins and proliferation capacity. Real-time quantitative polymerase chain reaction, western blot analysis, and immunofluorescence assays were conducted to elucidate the mechanisms underlying proliferation. Six candidate proteins were selected based on the results of proteomic profiling and GO functional enrichment. Through further validation, yes-associated protein 1 (YAP1) and ß-catenin were confirmed to affect MSCs proliferation rates. YAP1 and ß-catenin showed increased nuclear colocalization during cell expansion. YAP1 overexpression significantly enhanced proliferation capacity and upregulated the expression of both ß-catenin and the transcriptional targets of Wnt signaling, CCND1, and c-MYC, whereas silencing ß-catenin attenuated this influence. We found that YAP1 directly interacts with ß-catenin in the nucleus to form a transcriptional YAP/ß-catenin/TCF4 complex. Our study revealed that YAP1 and ß-catenin caused the different proliferation capacities of P-MSCs and UC-MSCs. Mechanism analysis showed that YAP1 stabilized the nuclear ß-catenin protein, and also triggered the Wnt/ß-catenin pathway, promoting proliferation.

Clinical Characteristics of Imported Cases of Coronavirus Disease 2019 (COVID-19) in Jiangsu Province: A Multicenter Descriptive Study.

BACKGROUND: We aimed to report the clinical characteristics of imported cases of coronavirus disease 2019 (COVID-19) in Jiangsu Province. METHODS: We retrospectively investigated the clinical, imaging, and laboratory characteristics of confirmed cases of COVID-19 with World Health Organization interim guidance in 3 grade IIIA hospitals of Jiangsu from 22 January to 14 February 2020. Real-time RT-PCR was used to detect the new coronavirus in respiratory samples. RESULTS: Of the 80 patients infected with COVID-19, 41 were female, with a median age of 46.1 years. Except for 3 severe patients, the rest of the 77 patients exhibited mild or moderate symptoms. Nine patients were unconfirmed until a third nucleic acid test; 38 cases had a history of chronic diseases. The main clinical manifestations of the patients were fever and cough, which accounted for 63 (78.75%) and 51 (63.75%) cases, respectively. Only 3 patients (3.75%) showed liver dysfunction. Imaging examination showed that 55 patients (68.75%) showed abnormal density shadow and 25 cases (31.25%) had no abnormal density shadow in the parenchyma of both lungs. Currently, 21 cases have been discharged from the hospital, and no patient died. The average length of stay for discharged patients was 8 days. CONCLUSIONS: Compared with the cases in Wuhan, the cases in Jiangsu exhibited mild or moderate symptoms and no obvious gender susceptibility. The proportion of patients having liver dysfunction and abnormal CT imaging was relatively lower than that in Wuhan. Notably, infected patients may be falsely excluded based on 2 consecutively negative respiratory pathogenic nucleic acid test results.

Characterizing the effects of hypoxia on the metabolic profiles of mesenchymal stromal cells derived from three tissue sources using chemical isotope labeling liquid chromatography-mass spectrometry.

Microenvironmental factors such as oxygen concentration mediate key effects on the biology of mesenchymal stromal cells (MSCs). Herein, we performed an in-depth characterization of the metabolic behavior of MSCs derived from the placenta, umbilical cord, and adipose tissue (termed hPMSCs, UC-MSCs, and AD-MSCs, respectively) at physiological (hypoxic; 5% oxygen [O2]) and standardized (normoxic; 21% O2) O2 concentrations using chemical isotope labeling liquid chromatography-mass spectrometry. 12C- and 13C-isotope dansylation (Dns) labeling was used to analyze the amine/phenol submetabolome, and 2574 peak pairs or metabolites were detected and quantified, from which 52 metabolites were positively identified using a library of 275 Dns-metabolite standards; 2189 metabolites were putatively identified. Next, we identified six metabolites using the Dns library, as well as 14 hypoxic biomarkers from the human metabolome database out of 96 altered metabolites. Ultimately, metabolic pathway analyses were performed to evaluate the associated pathways. Based on pathways identified using the Kyoto Encyclopedia of Genes and Genomes, we identified significant changes in the metabolic profiles of MSCs in response to different O2 concentrations. These results collectively suggest that O2 concentration has the strongest influence on hPMSCs metabolic characteristics, and that 5% O2 promotes arginine and proline metabolism in hPMSCs and UC-MSCs but decreases gluconeogenesis (alanine-glucose) rates in hPMSCs and AD-MSCs. These changes indicate that MSCs derived from different sources exhibit distinct metabolic profiles.

Altered faecal microbiota on the expression of Th cells responses in the exacerbation of patients with hepatitis E infection.

Fulminant hepatitis E may lead to acute liver failure (ALF). Perturbations of intestinal microbiota are related to severe liver disease. To study the correlations between faecal microbiota and the occurrence and exacerbation of hepatitis E virus (HEV) infection, we characterized 24 faecal samples from 12 patients with acute hepatitis E (AHE) and 12 patients with HEV-ALF using high-throughput sequencing. We found both the alpha and beta diversity indices showed no significant differences between the AHE and HEV-ALF groups. Several predominant taxa were significantly different between the AHE and HEV-ALF groups. Most notably, the HEV-ALF group had increased levels of Gammaproteobacteria, Proteobacteria, Xanthomonadceae and Stenotrophomonas, but reduced levels of Firmicutes, Streptococcus, Subdoligranulum and Lactobacillus, compared with the AHE group. The levels of Lactobacillaceae and Gammaproteobacteria could be used to distinguish patients with HEV-ALF from those with AHE. In addition, the level of Th lymphocytes was significantly lower in the HEV-ALF group than in the AHE group. The relative abundances of Lactobacillaceae and Gammaproteobacteria were positively correlated with Th lymphocytes, serum international normalized ratio (INR) and hepatic encephalopathy severity. Moreover, surviving patients had higher levels of Lactobacillus mucosae than deceased patients. Our study demonstrated that the presence of altered faecal microbiota is associated with exacerbation of HEV infection; this finding may be useful for exploring the interactions among faecal microbiota, immune responses, mechanisms of infection and progression in patients with HEV, as well as for the development of novel diagnostic and therapeutic strategies.

Reciprocal regulation of Akt and Oct4 promotes the self-renewal and survival of embryonal carcinoma cells.

Signaling via the Akt serine/threonine protein kinase plays critical roles in the self-renewal of embryonic stem cells and their malignant counterpart, embryonal carcinoma cells (ECCs). Here we show that in ECCs, Akt phosphorylated the master pluripotency factor Oct4 at threonine 235, and that the levels of phosphorylated Oct4 in ECCs correlated with resistance to apoptosis and tumorigenic potential. Phosphorylation of Oct4 increased its stability and facilitated its nuclear localization and its interaction with Sox2, which promoted the transcription of the core stemness genes POU5F1 and NANOG. Furthermore, in ECCs, unphosphorylated Oct4 bound to the AKT1 promoter and repressed its transcription. Phosphorylation of Oct4 by Akt resulted in dissociation of Oct4 from the AKT1 promoter, which activated AKT1 transcription and promoted cell survival. Therefore, a site-specific, posttranslational modification of the Oct4 protein orchestrates the regulation of its stability, subcellular localization, and transcriptional activities, which collectively promotes the survival and tumorigenicity of ECCs.

Recurrence of SARS-CoV-2 nucleic acid positive test in patients with COVID-19: a report of two cases.

BACKGROUND: The recurrence of positive SARS-CoV-2 nucleic acid test results in patients with COVID-19 is becoming more important and warrants more attention. CASE PRESENTATION: This study reports 2 cases, a child with mild COVID-19 and an adult female with moderate COVID-19, who were discharged after three consecutive negative nucleic acid tests and were later readmitted to the hospital for recurrence of SARS-CoV-2 nucleic acid positivity. By tracking the patients' symptoms, serum antibodies, and imaging manifestations after readmission, we found that they showed a trend of gradual improvement and recovery throughout treatment. They were cured without additional treatment, with the appearance of antibodies and the recovery of immune functions. CONCLUSIONS: It is deemed extremely necessary to improve the discharge standard of care. At the same time, nucleic acid detection is recommended to increase the dynamic monitoring of serum antibodies and imaging, strengthen the management of discharged patients, and appropriately extend the home or centralized isolation time.