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Background and Objectives@#Osteoblasts are derived from bone marrow mesenchymal stem cells (BMMSCs) and playimportant role in bone remodeling. While our previous studies have investigated the cell subtypes and heterogeneity in osteoblasts and BMMSCs separately, cell-to-cell communications between osteoblasts and BMMSCs in vivo in humans have not been characterized. The aim of this study was to investigate the cellular communication between human primary osteoblasts and bone marrow mesenchymal stem cells. @*Methods@#and Results: To investigate the cell-to-cell communications between osteoblasts and BMMSCs and identifynew cell subtypes, we performed a systematic integration analysis with our single-cell RNA sequencing (scRNA-seq) transcriptomes data from BMMSCs and osteoblasts. We successfully identified a novel preosteoblasts subtype which highly expressed ATF3, CCL2, CXCL2 and IRF1. Biological functional annotations of the transcriptomes suggested that the novel preosteoblasts subtype may inhibit osteoblasts differentiation, maintain cells to a less differentiated status and recruit osteoclasts. Ligand-receptor interaction analysis showed strong interaction between mature osteoblasts and BMMSCs. Meanwhile, we found FZD1 was highly expressed in BMMSCs of osteogenic differentiation direction. WIF1 and SFRP4, which were highly expressed in mature osteoblasts were reported to inhibit osteogenic differentiation. We speculated that WIF1 and sFRP4 expressed in mature osteoblasts inhibited the binding of FZD1 to Wnt ligand in BMMSCs, thereby further inhibiting osteogenic differentiation of BMMSCs. @*Conclusions@#Our study provided a more systematic and comprehensive understanding of the heterogeneity of osteogenic cells. At the single cell level, this study provided insights into the cell-to-cell communications between BMMSCs and osteoblasts and mature osteoblasts may mediate negative feedback regulation of osteogenesis process.
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Gut microbiota have been validated to play a pivotal role in metabolic regulation. As the most effective treatment for obesity and related comorbidities, bariatric surgery has been shown to result in significant alterations to the gut microbiota. Literature have recently suggested temporal and spatial features of alterations to the intestinal bacteria following bariatric surgery, which is possibly attributed to the gut adaptation to the surgical modification on the gastrointestinal tract. More importantly, the gut microbiota have been appreciated as a critical contributor to the metabolic improvements following bariatric surgery. Although not fully elucidated, the underlying mechanisms are associated with the molecular pathways mediating the crosstalk between gut microbiota and host . On the other hand, change of the gut microbiota has been found to be related to the prognosis of patients receiving bariatric surgery. Some studies even point out negative effects of the gut microbiota on certain surgical complications . In this review, we summarize the characteristics of alterations to the gut microbiota following bariatric surgery as well as its relevant impacts to better understand the role of gut microbiota in bariatric surgery.
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Humans , Bariatric Surgery , Gastrointestinal Microbiome/physiology , Gastrointestinal Tract , Obesity/surgery , Treatment OutcomeABSTRACT
Purpose To investigate the expression of signal transduction and activator 3 (Stat3) ,and phosphorylated Stat3 (p-Stat3) in human gastric cancer cell lines MGC-803 and BGC-823,and to explore the role of p-Stat3 in the invasion and migration of gastric cancer. Methods The expressed Stat3 and p-Stat3 in gastric cancer MGC-803 and BGC-823 cells were investigated by flow cytometry,and the migration and invasion abilities of cancer cells were observed using scratch test and in vitro Transwell test. Results Flow cytometry showed that the expression of Stat3 in MGC-803 and BGC-823 cells was basically unchanged before and after IL-6 stimulation (10 ng/mL) ,and the activated p-Stat3,however,was significantly higher after IL-6 stimulation. The activated p-Stat3 in BGC-823 cells was higher than that of MGC-803 cells (P < 0. 001) . The results of scratch tests showed that the scar healing area of BGC-823 cells was significantly larger than that of MGC-803 cells after 48 h (P = 0. 031) . Transwell cell experiments showed that the number of penetrating cells from BGC-823 cell line were significantly greater than those from MGC-803 cell line (P < 0. 001) . Conclusion Over activated p-Stat3 enhances the invasion and migration of MGC-803 and BGC-823 gastric cancer cells.
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Objective To evaluate the mutagenicity of hydrolysate of Meretrix meretrix Linnaeus soft tissue, so as to provide experimental basis for its exploitation.Methods Three mutagenicity tests were used to evaluate the mutagenic effects, including Ames test, CHL chromosome aberration assay and bone marrow micronucleus assay in mice.Results In Ames test, the revertant colonies numbers in each group were twice less than the numbers of spontaneous revertant colo-nies, five bacterial strains showed negative results with or without S9 activation, and the result of Ames test was negative. The CHL chromosome aberration assay and bone marrow micronucleus assay showed that the chromosome aberration rate and micronucleus rate of each dose group showed no significant difference compared with the negative control group, respec-tively ( P>0.05) .Conclusions Under this condition, the results show that all of the Ames test, chromosome aberration assay and bone marrow micronucleus assay are negative, and no mutagenicity is observed in the hydrolysate of Meretrix mer-etrix Linnaeus soft tissue.
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ObjectiveTheaimofthisstudywastoprovideabetterpositivecontrolforallergictestbycomparing the allergic effect of two kinds of positive materials , human albumin and ovalbumin , on active systemic anaphylaxis in guinea pig.Methods Guinea pigs were randomly divided into 14 groups, and were given human albumin , ovalbumin (2, 10, 100 mg/animal), or 0.9%sodium chloride injection as test substances , to assess the symptoms and incidence of systemic allergic responses induced by different sensitizing substances in different challenge doses and different challenge intervals.Results In the range of 2 to 100 mg/animal, the guinea pigs showed a 100%incidence rate of positive allergic reaction to human albumin and ovalbumin , the severity of anaphylactic symptoms was increasing along with the increase of sensitizing doses and challenge doses , and the allergic reaction was more strong induced by the same dose of ovalbumin than human albumin .Conclusions Our findings indicate that in the active systemic anaphylaxis test in guinea pigs , we recommend ovalbumin as the positive control in a dose of 2 mg/animal.