The effects of microgravity on stem cells and the new insights it brings to tissue engineering and regenerative medicine.

Conventional two-dimensional (2D) cell culture techniques may undergo modifications in the future, as life scientists have widely acknowledged the ability of three-dimensional (3D) in vitro culture systems to accurately simulate in vivo biology. In recent years, researchers have discovered that microgravity devices can address many challenges associated with 3D cell culture. Stem cells, being pluripotent cells, are regarded as a promising resource for regenerative medicine. Recent studies have demonstrated that 3D culture in microgravity devices can effectively guide stem cells towards differentiation and facilitate the formation of functional tissue, thereby exhibiting advantages within the field of tissue engineering and regenerative medicine. Furthermore, We delineate the impact of microgravity on the biological behavior of various types of stem cells, while elucidating the underlying mechanisms governing these alterations. These findings offer exciting prospects for diverse applications.

Simulated microgravity altered the gene expression profiles and inhibited the proliferation of Kupffer cells in the early phase by downregulating LMO2 and EZH2.

Microgravity is a primary challenge that need to overcome, when human travel to space. Our study provided evidence that Kupffer cells (KCs) are sensitive to simulated microgravity (SMG), and no similar research report has been found in the literature. Using transcriptome sequencing technology, it was showed that 631 genes were upregulated and 801 genes were downregulated in KCs after treatment under SMG for 3 days. The GO analysis indicated that the proliferation of KCs was affected when exposed to SMG for 3 days. CCK-8 assay confirmed that the proliferation of KCs was inhibited in the third day under the environment of SMG. Furthermore, we identified 8 key genes that affect the proliferation of KCs and predicted 2 transcription factors (TFs) that regulate the 8 key genes. Significantly, we found that microgravity could affect the expression of LMO2 and EZH2 to reduce the transcription of Racgap1, Ccna2, Nek2, Aurka, Plk1, Haus4, Cdc20, Bub1b, which resulting in the reduction in KCs proliferation. These finding suggested that the inhibition of KCs proliferation under microgravity may influence the homeostasis of liver, and LMO2 and EZH2 can be the targets in management of KCs' disturbance in the future practice of space medicine.

Transcription factor glucocorticoid modulatory element-binding protein 1 promotes hepatocellular carcinoma progression by activating Yes-associate protein 1.

BACKGROUND: Glucocorticoid modulatory element-binding protein 1 (GMEB1), which has been identified as a transcription factor, is a protein widely expressed in various tissues. Reportedly, the dysregulation of GMEB1 is linked to the genesis and development of multiple cancers. AIM: To explore GMEB1's biological functions in hepatocellular carcinoma (HCC) and figuring out the molecular mechanism. METHODS: GMEB1 expression in HCC tissues was analyzed employing the StarBase database. Immunohistochemical staining, Western blotting and quantitative real-time PCR were conducted to examine GMEB1 and Yes-associate protein 1 (YAP1) expression in HCC cells and tissues. Cell counting kit-8 assay, Transwell assay and flow cytometry were utilized to examine HCC cell proliferation, migration, invasion and apoptosis, respectively. The JASPAR database was employed for predicting the binding site of GMEB1 with YAP1 promoter. Dual-luciferase reporter gene assay and chromatin immunoprecipitation-qPCR were conducted to verify the binding relationship of GMEB1 with YAP1 promoter region. RESULTS: GMEB1 was up-regulated in HCC cells and tissues, and GMEB1 expression was correlated to the tumor size and TNM stage of HCC patients. GMEB1 overexpression facilitated HCC cell multiplication, migration, and invasion, and suppressed the apoptosis, whereas GMEB1 knockdown had the opposite effects. GMEB1 bound to YAP1 promoter region and positively regulated YAP1 expression in HCC cells. CONCLUSION: GMEB1 facilitates HCC malignant proliferation and metastasis by promoting the transcription of the YAP1 promoter region.

Laparoscopy-assisted versus open gastrectomy with D2 lymph node dissection for advanced gastric cancer: a meta-analysis.

A raising number of surgeons have chosen laparoscopy-assisted gastrectomy (LAG) as an alternative to open gastrectomy (OG) with D2 lymph node dissection for treatment of advanced gastric cancer (ADG). But no meta-analysis has been performed to evaluate the value of LAG versus OG with regard to safety and efficacy for treatment of ADG. A comprehensive literature research was performed in PubMed, Web of Science and Embase to identify studies that compared LAG and OG with D2 lymph node dissection for treatment of ADG. Data of interest were checked and subjected to meta-analysis with RevMan 5.1 software. 11 studies with 1904 patients (982 in LAG and 922 in OG) were enrolled. Pooled risk ratios (RR) and weighted mean difference (WMD) with 95% confidence intervals (CI) were appropriately derived from random-effects models or fixed-effects models. Compared with OG, LAG was associated with less blood loss (WMD = -144.47; P < 0.05), shorter time of first flatus time (WMD = -0.91; P < 0.05) and postoperative hospital stay (WMD = -3.27; P < 0.05), and lower morbidity (RR = 0.70; P < 0.05), but longer operation time (WMD = 41.78; P < 0.05). No significant differences were noted in terms of harvested lymph nodes (WMD = 1.85; P = 0.09), pathological N stage (χ(2) 3.97; P = 0.26), tumor size (WMD = -0.05; P = 0.81), mortality (RR 0.82; P = 0.76), cancer recurrence rate (RR 0.77; P = 0.18) and 3-year overall survival rate (RR 1.09; P = 0.18). Compared with OG, LAG with D2 lymph node dissection for ADG had the advantages of minimal invasion, faster recovery, and fewer complications, and it could achieve the same degree of radicality, harvested lymph nodes, short-term and long-term prognosis as OG, though the operation time was slightly longer.