A covalent organic framework as a photocatalyst for window ledge cross-dehydrogenative coupling reactions.

A benzothiadiazole-involving donor-acceptor (D-A) covalent organic framework (COF), which has high crystallinity and strong light-harvesting capability (ranging from 300 to 800 nm), can serve as a highly effective photocatalyst for window ledge aerobic cross-dehydrogenative coupling (CDC) reactions (such as Mannich and aza-Henry reactions) even at a gram level.

TRIM52 up-regulation in hepatocellular carcinoma cells promotes proliferation, migration and invasion through the ubiquitination of PPM1A.

BACKGROUND: Many tripartite motif (TRIM) family proteins have been reported to be of great importance in the initiation and progression in hepatocellular carcinoma (HCC). However, the biological role and regulatory mechanism of tripartite motif containing 52 (TRIM52) in HCC development and progression are poorly defined. METHODS: Immunohistochemistry (IHC), quantitative real-time PCR (qRT-PCR) or Western blot analysis was used to detect TRIM52, p21, matrix metalloproteinase 2 (MMP2), protein phosphatase, Mg2+/Mn2+ dependent 1A (PPM1A), p-Smad2/3 and Smad2/3 levels in HCC tissues and cell lines. HCC cell proliferation and cell cycle were measured by Cell Counting Kit-8 (CCK-8) and flow cytometry analysis, respectively. HCC cell migration and invasion were measured by Transwell assay. Tumor growth of HCC cells in vivo was measured using the nude mouse xenograft model. The correlation between TRIM52 and PPM1A was measured by co-immunoprecipitation (Co-IP) and ubiquitination analysis in vitro. RESULTS: TRIM52 was significantly up-regulated in the HCC tissues in comparison with the adjacent non-tumor hepatic tissues. TRIM52 was also up-regulated in HCC cell lines (MHCC-97H and MHCC-97L cells) compared with normal human liver cell line LO2. TRIM52 down-regulation by RNA interfering in MHCC-97H cells enhanced inhibition of cell proliferation, migration and invasion. TRIM52 down-regulation also induced MHCC-97H cells arrest in G0-G1 phase cell cycle and inhibited MHCC-97H cell growth in the nude mice. However, TRIM52 up-regulation in MHCC-97L cells promoted cell proliferation, migration and invasion. Furthermore, TRIM52 down-regulation significantly increased p21 and PPM1A expression, but inhibited MMP2 expression and induced Smad2/3 dephosphorylation in MHCC-97H cells, which were reversed by TRIM52 up-regulation in MHCC-97L cells. TRIM52 was found interacted with PPM1A and TRIM52 down-regulation inhibited the ubiquitination of PPM1A. Importantly, PPM1A up-regulation in MHCC-97L cells significantly suppressed TRIM52-mediated enhancement on cell proliferation, invasion and migration. CONCLUSIONS: Our findings suggest that TRIM52 up-regulation promotes proliferation, migration and invasion of HCC cells through the ubiquitination of PPM1A.

Protective effect of glutamine on intestinal injury and bacterial community in rats exposed to hypobaric hypoxia environment.

AIM: To investigate the protective effect of glutamine (Gln) on intestinal injury and the bacterial community in rats exposed to hypobaric hypoxia environment. METHODS: Sprague-Dawley rats were divided into control, hypobaric hypoxia (HH), and hypobaric hypoxia + Gln (5.0 g/kg BW·d) (HG) groups. On the first 3 d, all rats were placed in a normal environment. After the third day, the HH and HG groups were transferred into a hypobaric chamber at a simulated elevation of 7000 m for 5 d. The rats in the HG group were given Gln by gavage daily for 8 d. The rats in the control and HH groups were treated with the same volume of saline. The intestinal morphology, serum levels of malondialdehyde (MDA), superoxide dismutase (SOD), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interferon-gamma (IFN-γ) and diamino oxidase (DAO) were examined. We also evaluated the expression levels of occludin, toll-like receptor 4 (TLR4), nuclear factor-κB p65 (NF-κB p65) and myeloid differentiation factor 88 (MyD88), and examined the bacterial community in caecal contents. RESULTS: Hypobaric hypoxia induced the enlargement of the heart, liver, lung and kidney, and caused spleen atrophy. Intestinal villi damage was also observed in the HH group. Supplementation with Gln significantly alleviated hypobaric-induced damage to main organs including the intestine, increased serum SOD (1.14 ± 0.03 vs 0.88 ± 0.04, P < 0.05) and MDA (8.35 ± 1.60, P < 0.01) levels and decreased serum IL-6 (1172.13±30.49 vs 1407.05 ± 34.36, P < 0.05), TNF-α (77.46 ± 0.78 vs 123.70 ± 3.03, P < 0.001), IFN-γ (1355.42 ± 72.80 vs 1830.16 ± 42.07, P < 0.01) and DAO (629.30 ± 9.15 vs 524.10 ± 13.34, P < 0.001) levels. Moreover, Gln significantly increased occludin (0.72 ± 0.05 vs 0.09 ± 0.01, P < 0.001), TLR4 (0.15 ± 0.05 vs 0.30 ±0.09, P < 0.05), MyD88 (0.32 ± 0.08 vs 0.71 ± 0.06, P < 0.01), and NF-κB p65 (0.16 ± 0.04 vs 0.44 ± 0.03, P < 0.01) expression levels and improved the intestinal bacterial community. CONCLUSION: Gln treatment protects from intestinal injury and regulates the gut flora imbalance in hypoxia environment. These effects may be related to the TLR4/MyD88/NF-κB signaling pathway.