Adiponectin (APN), an adipose tissue-excreted adipokine, plays protective roles in metabolic and cardiovascular diseases. In this study, the effects and mechanisms of APN on biological functions of rat vascular endothelial progenitor cells (VEPCs) were investigated in vitro . After administrating APN in rat VEPCs, the proliferation was measured by methyl thiazolyl tetrazolium (MTT) method, the apoptotic rate was test by Flow cytometry assay, mRNA expression of B-cell lymphoma-2 (Bcl-2) and vascular endothelial growth factor (VEGF) was determined by real-time reverse transcriptase polymerase chain reaction (RT-PCR), and protein expression of mechanistic target of rapamycin (mTOR), signal transducer and activator of transcription 3 (STAT3) and phospho-STAT3 (pSTAT3) was analyzed by Western blot. It was suggested that APN promoted the optical density (OD) value of VEPCs, enhanced mRNA expression of Bcl-2 and VEGF, and inhibited cell apoptotic rate. Furthermore, protein expression of pSTAT3 was also increased in the presence of APN. Moreover, APN changed-proliferation, apoptosis and VEGF expression of VEPCs were partially suppressed after blocking the mTOR-STAT3 signaling pathway by the mTOR inhibitor XL388. It was indicated that APN promoted biological functions of VEPCs through targeting the mTOR-STAT3 signaling pathway., Xiaoying Dong, Xia Yan, Wei Zhang, Shengqiu Tang., and Obsahuje bibliografii
Non-small cell lung cancer (NSCLC) results in high mortality and has gained increasing attention. C-Phycocyanin (C-PC) has been identified as a potential therapeutic inhibitor for NSCLC, but its underlying mechanism remains obscure. The gene expression of the long noncoding RNA neighbour of BRCAI RNA 2 (NBR2) in NSCLC cells was evaluated by quantitative reverse transcription-PCR. The cell capacity for proliferation and migration was examined by EdU and wound-healing assays. Furthermore, the viability and apoptosis of cells was measured with CCK-8 and annexin V/PI, respectively. Next, the protein level of activation of adenosine monophosphate- activated protein kinase and the rapamycin kinase (mTOR) signalling pathway-associated molecules was evaluated by western blotting. H292 cells were pre-treated with C-PC or transfected with plasmids encoding NBR2 or the shNBR2 plasmid, to over-express or knock down NBR2 expression, respectively. NBR2 expression was robustly down-regulated in NSCLC cell lines compared with a normal cell line (BEAS-2B). NBR2 over-expression inhibited migration and promoted apoptosis of H292 cells. Treatment of H292 cells with C-PC enhanced NBR2 levels in a dose- and time-dependent manner. Downregulation of NBR2 in H292 cells inhibited the activity of C-PC on cell proliferation, viability and clone formation. Further mechanistic investigation showed that the down-regulation of NBR2 abolished the modulatory effects of C-PC on the AMPK/mTOR signalling pathway. In conclusion, C-PC inhibits H292 cell growth by enhancing the NBR2/AMPK signalling pathway.
Leptin is a hormone primarily secreted by adipocytes and participating in the regulation of food intake and energy expenditure. Its blood levels usually correlate with adiposity. The secretion of this hormone is affected, among others, by food consumption, insulin, fasting and cold exposure. Regulation of leptin secretion depends on many intracellular events. It is known that the activation of mTOR (the mamma lian target of rapamycin) as well as increase in ATP and malonyl-CoA content in adipocytes enhance secretion of leptin. The rise in intracellular cAMP and fatty acids is thought to evoke the opposite effect. Moreover, the undisturbed action of endogenous adenosine in adipocytes and the proper intracellular Ca2+ concentration in these cells were also found to have an important function in leptin release. The role of mTOR, ATP, cAMP, fatty acids, malonyl-CoA, adenosine and Ca2+ in the regulation of leptin secretion from adipocytes is discussed., T. Szkudelski., and Obsahuje bibliografii a bibliografické odkazy
Biguanidy jsou léky určené pro terapii hyperglykemie u diabetu 2. typu. V poslední době se ukazuje, že nejčastěji předepisovaný biguanid metformin vykazuje také protinádorový účinek. Jeho možné využití v protinádorové léčbě podporují epidemiologické, preklinické a klinické studie. Příznivé ovlivnění karcinomu prsu a tlustého střeva by mohlo souviset s primární schopností metforminu snižovat hladinu cirkulujícího inzulinu, ale metformin má nepochybně i přímý cytostatický efekt, který se uskutečňuje prostřednictvím inhibice mTOR (mammalian target of rapamycin) signální dráhy a blokádou syntézy proteinů. Využití metforminu v protinádorové léčbě nebo chemoprevenci nádorů ale ukáže teprve budoucnost., Metformin, an oral biguanide antidiabetic drug, is the most widely prescribed agent for treatment of type 2 diabetes. The drug mainly works by lowering glucose production by the liver, and thus lowering fasting blood glucose. Metformin acts as an insulin sensitizer, which leads to inhibition of gluconeogenesis in the liver, and has been found to be beneficial especially in overweight patients with diabetes. Metformin use has been postulated to contribute to a reduced risk of pancreatic, prostate, ovarian, and breast cancers. Metformin‘ s mechanism of action was examined recently and determined to be initiated by metformins role as an adenosine 5‘-mono-phosphate– activated protein kinase (AMPK) activator through a tumor suppressor protein kinase known as LKB-1, which regulates AMPK levels. Activation of AMPK has been shown to suppress the mammalian target of the rapamycin (mTOR) signaling pathway, leading to antiproliferative and antiangiogenic effects., Petra Tesařová, and Literatura 21