Hypothalamic steroid receptor coactivator-2 regulates adaptations to fasting and overnutrition.

The neuroendocrine system coordinates metabolic and behavioral adaptations to fasting, including reducing energy expenditure, promoting counterregulation, and suppressing satiation and anxiety to engage refeeding. Here, we show that steroid receptor coactivator-2 (SRC-2) in pro-opiomelanocortin (POMC) neurons is a key regulator of all these responses to fasting. POMC-specific deletion of SRC-2 enhances the basal excitability of POMC neurons; mutant mice fail to efficiently suppress energy expenditure during food deprivation. SRC-2 deficiency blunts electric responses of POMC neurons to glucose fluctuations, causing impaired counterregulation. When food becomes available, these mutant mice show insufficient refeeding associated with enhanced satiation and discoordination of anxiety and food-seeking behavior. SRC-2 coactivates Forkhead box protein O1 (FoxO1) to suppress POMC gene expression. POMC-specific deletion of SRC-2 protects mice from weight gain induced by an obesogenic diet feeding and/or FoxO1 overexpression. Collectively, we identify SRC-2 as a key molecule that coordinates multifaceted adaptive responses to food shortage.

A network pharmacology perspective for deciphering potential mechanisms of action of Solanum nigrum L. in bladder cancer.

BACKGROUND: Solanum nigrum L. decoction has been used as a folklore medicine in China to prevent the postoperative recurrence of bladder cancer (BC). However, there are no previous pharmacological studies on the protective mechanisms of this activity of the plant. Thus, this study aimed to perform a systematic analysis and to predict the potential action mechanisms underlying S. nigrum activity in BC based on network pharmacology. METHODS: Based on network pharmacology, the active ingredients of S. nigrum and the corresponding targets were identified using the Traditional Chinese Medicines for Systems Pharmacology Database and Analysis Platform database, and BC-related genes were screened using GeneCards and the Online Mendelian Inheritance in Man database. In addition, ingredient-target (I-T) and protein-protein interaction (PPI) networks were constructed using STRING and Cytoscape, Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted, and then the pathways directly related to BC were integrated manually to reveal the pharmacological mechanism underlying S. nigrum-medicated therapeutic effects in BC. RESULTS: Seven active herbal ingredients from 39 components of S. nigrum were identified, which shared 77 common target genes related to BC. I-T network analysis revealed that quercetin was associated with all targets and that NCOA2 was targeted by four ingredients. Besides, interleukin 6 had the highest degree value in the PPI network, indicating a hub role. A subsequent gene enrichment analysis yielded 86 significant GO terms and 89 significant pathways, implying that S. nigrum had therapeutic benefits in BC through multi-pathway effects, including the HIF-1, TNF, P53, MAPK, PI3K/Akt, apoptosis and bladder cancer pathway. CONCLUSIONS: S. nigrum may mediate pharmacological effects in BC through multi-target and various signaling pathways. Further validation is required experimentally. Network pharmacology approach provides a predicative novel strategy to reveal the holistic mechanism of action of herbs.

Anti-estrogenic activity of a human resveratrol metabolite.

BACKGROUND AND AIMS: Resveratrol, the most investigated dietary compound in studies aimed at linking wine consumption to human health, is an extremely minor component of this beverage and it is generally studied in vitro as the unconjugated aglycone at concentrations largely exceeding those found in the human circulatory system after dietary intake. Moreover, following intestinal absorption, trans-resveratrol and its glucoside, which are naturally present in wine and other food sources, are converted to sulphate and glucuronide metabolites. An estrogenic activity has previously been documented for resveratrol, yet nothing is known about the activity of its blood-circulating metabolic derivatives. METHODS AND RESULTS: Using a yeast two-hybrid detection system relying on the interaction between the ligand-binding domain of the human oestrogen receptors α and ß and the human coactivator Tif2, we have systematically examined the oestrogen agonist and antagonist activities of the two main resveratrol forms present in planta (trans-resveratrol and trans-resveratrol-3-O-glucoside) and of the three main metabolites found in human plasma (trans-resveratrol-3-O-sulphate, trans-resveratrol-3-O-glucuronide and trans-resveratrol-4'-O-glucuronide). Only resveratrol-3-O-sulphate was found to display a fairly strong and oestrogen receptor α-preferential antagonistic activity, which was confirmed in a human breast adenocarcinoma cell line containing a luciferase reporter gene under the control of an oestrogen-responsive promoter. CONCLUSIONS: We show, for the first time, that resveratrol-3-O-sulphate, but neither of its metabolites, is endowed with anti-estrogenic activity and how human metabolism of phenolic substances plays a pivotal role in modulating their biological effect.

The reduced form of coenzyme Q10 decreases the expression of lipopolysaccharide-sensitive genes in human THP-1 cells.

Monocytes are key players in inflammatory processes that are triggered by lipopolysaccharide (LPS), the major outer membrane component of Gram-negative bacteria. The present study in human monocytic THP-1 cells was designed in order to identify LPS-inducible genes that are down-regulated by the reduced form of coenzyme Q(10) (ubiquinol, Q(10)H(2)). For this purpose, THP-1 cells were incubated with 10 µM Q(10)H(2) for 24 hours. Subsequently, cells were stimulated for 4 hours with 1 µg/mL LPS, and the resulting gene expression levels were determined using microarrays. Fourteen LPS-inducible genes were identified to be significantly (P ≤ .05) down-regulated by Q(10)H(2) pretreatment between a factor of 1.32 and 1.65. The strongest effect of Q(10)H(2) incubation was found for the nuclear receptor coactivator 2 gene (NCOA2). Gene ontology terms revealed for the Q(10)H(2)-sensitive genes an involvement in, e.g., signal transduction processes (centaurin, delta 1; NCOA2; pleckstrin and Sec7 domain containing 3; protein phosphatase 2, regulatory subunit B [B56], γ isoform), transcriptional regulation (NCOA2; POU domain, class 2, transcription factor 1; ETS variant gene 3), and cell proliferation pathways (hypothetical protein FLJ36090, epidermal growth factor receptor pathway substrate 15). In conclusion, we provide evidence in THP-1 cells that Q(10)H(2) modulates LPS-induced gene expression.