Objective To investigate the effect and mechanism of decorin (DCN) on invasion of colorectal cancer cell line HCT116 in vitro.Methods Transwell assay was employed to detect the invasion of HCT116 cells;Real-time PCR was used to detect the expression of CD133 and TIMP-2 mRNA of HCT116 cells;Western blot method was used to detect the expression of HIF-1α, CD133 and TIMP-2 protein of HCT116 cells.Results 1) When the concentrations of DCN was 0, 1 and 3 mg/L, under the conditions of normal oxygen and hypoxia, the numbers of invasive cells were (241±46), (168±46), (51±17) fields in each well (P<0.01) and (207±61), (213±64), (156±54), (44±17) fields in each well (P<0.01).2) Under the normoxic conditions, the TIMP-2 mRNA and protein in HCT116 cells were increased by DCN (3 mg/L) (P<0.01), but that of CD133 were not affected.3) DCN (3 mg/L) significantly decreased the expression of HIF-1α/CD133/TIMP-2 protein in HCT116 cells under hypoxia (P<0.01), but had no significant effect on the expression of CD133 mRNA.ConclusionsUnder the conditions of hypoxia and normal oxygen, DCN may function through different mechanisms to inhibit the invasion of colorectal adenocarcinoma cell line HCT116 in vitro.

Emerging evidence indicates that the gut microbiome contributes to the host immune response to infectious diseases. Here, to explore the role of the gut microbiome in the host immune responses in COVID-19, we conducted shotgun metagenomic sequencing and immune profiling of 14 severe/critical and 24 mild/moderate COVID-19 cases as well as 31 healthy control samples. We found that the diversity of the gut microbiome was reduced in severe/critical COVID-19 cases compared to mild/moderate ones. We identified the abundance of some gut microbes altered post-SARS-CoV-2 infection and related to disease severity, such as Enterococcus faecium, Coprococcus comes, Roseburia intestinalis, Akkermansia muciniphila, Bacteroides cellulosilyticus and Blautia obeum. We further analyzed the correlation between the abundance of gut microbes and host responses, and obtained a correlation map between clinical features of COVID-19 and 16 severity-related gut microbe, including Coprococcus comes that was positively correlated with CD3⁺/CD4⁺/CD8⁺ lymphocyte counts. In addition, an integrative analysis of gut microbiome and the transcriptome of peripheral blood mononuclear cells (PBMCs) showed that genes related to viral transcription and apoptosis were up-regulated in Coprococcus comes low samples. Moreover, a number of metabolic pathways in gut microbes were also found to be differentially enriched in severe/critical or mild/moderate COVID-19 cases, including the superpathways of polyamine biosynthesis II and sulfur oxidation that were suppressed in severe/critical COVID-19. Together, our study highlighted a potential regulatory role of severity related gut microbes in the immune response of host.
COVID-19 ; Clostridiales ; Gastrointestinal Microbiome ; Humans ; Immunity ; Leukocytes, Mononuclear ; SARS-CoV-2