Inhibition of TAF1B impairs ribosome biosynthesis and suppresses cell proliferation in stomach adenocarcinoma through promoting c-MYC mRNA degradation.

Hyperactivation of ribosome biosynthesis (RiBi) is a hallmark of cancer, and targeting ribosome biogenesis has emerged as a potential therapeutic strategy. The depletion of TAF1B, a major component of selectivity factor 1 (SL1), disrupts the pre-initiation complex, preventing RNA polymerase I from binding ribosomal DNA and inhibiting the hyperactivation of RiBi. Here, we investigate the role of TAF1B, in regulating RiBi and proliferation in stomach adenocarcinoma (STAD). We disclosed that the overexpression of TAF1B correlates with poor prognosis in STAD, and found that knocking down TAF1B effectively inhibits STAD cell proliferation and survival in vitro and in vivo. TAF1B knockdown may also induce nucleolar stress, and promote c-MYC degradation in STAD cells. Furthermore, we demonstrate that TAF1B depletion impairs rRNA gene transcription and processing, leading to reduced ribosome biogenesis. Collectively, our findings suggest that TAF1B may serve as a potential therapeutic target for STAD and highlight the importance of RiBi in cancer progression.

Hesperetin, a SIRT1 activator, inhibits hepatic inflammation via AMPK/CREB pathway.

Silent mating type information regulation 2 homolog 1 (SIRT1) is an important inflammatory regulator, which epigenetically reprograms inflammation by altering the acetylation of NF-κB. Hesperetin, as a common flavonoid, has been proven to have a significant effect on acute inflammatory diseases. However, the detailed molecular mechanism by which hesperetin alleviates inflammatory response and accompanied tissue injury is poorly understood. Our results show that SIRT1 is required for the inhibitory effect of hesperetin on inflammation. Hesperetin suppresses the acetylation of RelA/p65 to reduce NF-κB activity by inducing SIRT1 expression. Mechanistically, hesperetin increases SIRT1 expression through AMPK/CREB pathway. Additionally, the protective effect of hesperetin against LPS/D-GalN-induced hepatitis in mice is also dependent on SIRT1. Our study suggests that hesperetin is an SIRT1 activator and could be potential candidates for the treatments of inflammatory conditions.

Neohesperidin enhances PGC-1α-mediated mitochondrial biogenesis and alleviates hepatic steatosis in high fat diet fed mice.

BACKGROUNDS: Mitochondria plays a critical role in the development and pathogenesis of nonalcoholic fatty liver disease (NAFLD). Neohesperidin (NHP) could lower blood glucose and prevent obesity in mice. However, the direct effect of NHP on hepatic steatosis has not been reported. METHODS: Mice were fed with either a chow diet or HFD with or without oral gavage of NHP for 12 weeks. A variety of biochemical and histological indicators were examined. In vitro cell culture model was utilized to demonstrate underlying molecular mechanism of the effect induced by NHP treatment. RESULTS: NHP increases mitochondrial biogenesis, improves hepatic steatosis and systematic insulin resistance in high fat diet (HFD) fed mice. NHP elevates hepatic mitochondrial biogenesis and fatty acid oxidation by increasing PGC-1α expression. Mechanistically, the activation of AMP-activated protein kinase (AMPK) is involved in NHP induced PGC-1α expression. CONCLUSIONS: PGC-1α-mediated mitochondrial biogenesis plays a vital role in the mitigation of hepatic steatosis treated by NHP. Our result suggests that NHP is a good candidate to be dietary supplement for the auxiliary treatment of NAFLD.

Cinobufacini ameliorates experimental colitis via modulating the composition of gut microbiota.

BACKGROUND: Cinobufacini, the sterilized hot water extraction of dried toad skin, has been widely used in the treatment of inflammation and cancers. Recently we found cinobufacini could ameliorate dextran sulfate sodium (DSS)-induced colitis in mice, but the underlying mechanism was not fully understood. In current study, we explored the effect of cinobufacini on gut microbiota in DSS-induced acute colitic mouse model by pyrosequencing of colonic contents. METHODS: C57BL/6 mice were supplied with normal or 3.0% DSS containing drinking water. DSS-treat mice were gavaged daily either with vehicle (water) or cinobufacini (10.0 or 30.0 mg/kg) for 7 days. The composition of the gut microbiota was assessed by analyzing 16S rRNA gene sequences. RESULTS: Our data indicated that cinobufacini reversed DSS-induced gut dysbiosis and enhanced intestinal barrier integrity. Moreover, changing of some specific microbial groups such as Proteobacteria and Bacteroides was closely correlated with the re-establishment of intestinal equilibrium and the recovery of intestinal function. CONCLUSION: Cinobufacini prevents colitis in mice by modifying the composition and function of gut microbiota. The current study provides additional mechanistic insight in the therapeutic effect of cinobufacini treatment and may pave the way for clinical application of cinobufacini in colitis therapy.

Yes-associated protein at the intersection of liver cell fate determination.

A recent publication highlights the importance of high yes-associated protein (YAP) expressing cells in liver regeneration following partial hepatectomy. Although the names of the cell populations described in these articles [hybrid periportal hepatocytes (HybHP) or epithelial-mesenchymal transition (EMT)-reprogrammed hepatocytes] are not identical, they all express high levels of YAP. We hypothesize that the HybHP and EMT-reprogrammed hepatocytes might be a similar cell population. Hippo signaling is the primary pathway that regulates YAP activity. According to the contribution of these two types of cells to liver regeneration and the high YAP expression, Hippo-YAP signaling activation may be a common regulatory pathway experienced by cells undergoing dedifferentiation and reactivating proliferative activity during liver regeneration. Although no evidence has shown that HybHP cells contribute to hepatocellular carcinoma in mouse models, we can not rule out the possibility that these highly regenerative cells can further develop into tumor cells when they acquire mutations caused by viral infection or other risk factors like alcohol. The detailed mechanistic insight of the regulation of YAP expression and activity in HybHP (or other types of cells contributing to liver regeneration) is unknown. We hypothesize that liver regeneration under various conditions will eventually lead to divergent consequences, likely due to the duration of YAP activation regulated by Hippo-large tumor suppressor 1 and 2 pathway in a context- and cell type-dependent manner.

Cinobufacini Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice through Inhibiting M1 Macrophage Polarization.

Cinobufacini is a traditional Chinese medicine used clinically that has antitumor and anti-inflammatory effects. It improves colitis outcomes in the clinical setting, but the mechanism underlying its function yet to be uncovered. We investigated the protective effects and mechanisms of cinobufacini on colitis using a dextran sulfate sodium (DSS)-induced colitis mouse model, mainly focusing on the impact of macrophage polarization. Our results showed that cinobufacini dramatically ameliorated DSS-induced colitis in mice. Cinobufacini treatment reduced the infiltration of activated F4/80+ and/or CD68+ macrophages into the colon in DSS-induced colitis mice. More importantly, cinobufacini significantly decreased the quantity of M1 macrophages and the expression of proinflammatory cytokines such as interleukin-6, tumor necrosis factor α, and inducible nitric oxide synthase. Cinobufacini also increased the population of M2 macrophages and the expression of anti-inflammatory factors such as interleukin-10 and arginase-1 in DSS-induced colitis mice. Furthermore, our study demonstrated that cinobufacini inhibited M1 macrophage polarization in lipopolysaccharide-induced RAW 264.7 cells. Mechanistically, our in vivo and in vitro results showed that cinobufacini inhibition of M1 macrophage polarization may be associated with the suppression of nuclear factor κB activation. Our study suggests that cinobufacini could ameliorate DSS-induced colitis in mice by inhibiting M1 macrophage polarization.

NF-кB increases LPS-mediated procalcitonin production in human hepatocytes.

For years, procalcitonin (PCT) has been employed as a diagnostic biomarker for the severity of sepsis and septic shock, as well as for guiding the application of antibiotics. However, the molecular/cellular basis for the regulation of PCT production is not fully understood. In this study, we identified the signalling pathway by which the expression of PCT was induced by lipopolysaccharide in human hepatocytes at the mRNA and protein levels. This expression was dependent on nuclear transcription factor κB (NF-κB), as indicated by a NF-κB binding site (nt -53 to -44) found in the PCT promoter region. We also showed that microRNA-513b (miR-513b) was also able to bind to the 3'-untranslated region (UTR) of the PCT promoter sequence. Meanwhile, the activation of NF-κB down-regulated the expression of miR-513b. In conclusion, we suggest that NF-κB is capable of enhancing the expression of PCT by either directly activating the transcription of the PCT gene or indirectly modulating the expression of its regulatory component, miR-513b. Our results indicate a molecular mechanism responsible for the regulation of PCT production.

Lipin-1 determines lung cancer cell survival and chemotherapy sensitivity by regulation of endoplasmic reticulum homeostasis and autophagy.

Cancer cells undergo comprehensive metabolic reprogramming to meet the increased requirements of energy and building blocks for proliferation. Lipin-1, a phosphatidic acid phosphatase converting phosphatidic acid (PA) to diacylglycerol (DAG), is upregulated in lung adenocarcinoma (LUAD) cell lines and tumor tissues. In this study, we reveal high lipin-1 expression is correlated with poor prognosis of patients with LUAD. Knockdown of lipin-1 decreases cell viability and proliferation in LUAD cells, whereas it has less effect on nontumorigenic lung cells. Autophagy and ER stress play important roles in tumor initiation and progression. Lipin-1 knockdown induces the initiation of autophagy while disrupts formation of autolysosome. Lipin-1 silencing induces the activation of ER stress through the IRE1α pathway. Furthermore, we demonstrate disrupted ER homeostasis contributes to the cell phenotype, and the elevated autophagy initiation is due to the ER stress in part. For the first time, we show lack of lipin-1 enhances the sensitivity of LUAD cells to cisplatin treatment. Our results suggest that lipin-1 is a potential target, alone or combined with other treatment, for lung cancer therapy.

SLC2A5 promotes lung adenocarcinoma cell growth and metastasis by enhancing fructose utilization.

The metabolism of cancer cells is highly plastic. Cancer cells can change their preference for nutrient uptake under nutrient stress. Fructose is one of the most common carbohydrates in diet and its metabolism is also involved in the development and progression of tumors. GLUT5, encoded by SLC2A5, is the specific fructose transporter in mammalian cells. In this study, we found that SLC2A5 is significantly upregulated in lung adenocarcinoma (LUAD) patients and overexpression of SLC2A5 is highly correlated with poor prognosis of LUAD patients. The expression of SLC2A5 determined fructose uptake and utilization efficacy in LUAD cells. GLUT5 is critical for the survival of LUAD cells in fructose-containing culture medium. Depletion of SLC2A5 undermined cell proliferation and invasion meanwhile increased cell apoptosis. Overexpression of SLC2A5 enhances cell proliferation, migration, invasion, and tumorigenic. Compared to glucose, fructose is prone to strengthen intracellular-free fatty acid accumulation and ATP production. Moreover, inhibition of GLUT5 by specific small chemical inhibitor sensitizes LUAD cells to paclitaxel treatment. Taken together, our results suggest that GLUT5 could be a potential target alone or combination with other treatment for lung cancer therapy.

Astilbin ameliorates cisplatin-induced nephrotoxicity through reducing oxidative stress and inflammation.

Oxidative stress and inflammation are considered to be the main pathogenesis of cisplatin nephrotoxicity. Astilbin, a flavonoid with anti-oxidation and anti-inflammation function, has been used to treat heavy metal induced kidney injury. In this study, we investigated the protective effects of astilbin on cisplatin-induced nephrotoxicity and its underlying mechanisms. Our results showed that astilbin markedly inhibited cisplatin-induced cell apoptosis and recovered cell growth. Astilbin significantly decreased reactive oxygen species (ROS) accumulation and alleviated ROS-induced activation of p53, MAPKs and AKT signaling cascades, which in turn attenuated cisplatin-induced HEK-293 cell apoptosis. Astilbin effectively enhanced NRF2 activation and transcription of its targeting antioxidant genes to reduce ROS accumulation in cisplatin-induced HEK-293 cells. Furthermore, we found that astilbin obviously suppressed tumor necrosis factor alpha (TNF-α) expression and NF-κB activation, and also inhibited the expression of induced nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Finally, we confirmed that the effect of astilbin to improve renal oxidative stress and inflammation in cisplatin induced acute nephrotoxic mice. In conclusion, our study suggests that astilbin could ameliorate the cisplatin-induced nephrotoxicity by reducing oxidative stress and inflammation.