Project description:1. Fermentative activities of colon microbiota pre-exposed to celecoxib oscillate and endure irreversible modifications following continuous NSAID supplementation in a simulated model of the gut microbial ecosystem
Project description:Decreased diversity of butyrate-producing bacteria followed by functional adjustment occurs in the microbiome of the simulated proximal colon upon long-term treatment with aspirin
Project description:Celecoxib builds up and cues metabolically active bacteria inhabiting the mucosal environment of a simulated human intestinal ecosystem, modulating inflammatory response
Project description:Obesity is associated with an increased risk of colon cancer. Our current study examines whether weight loss and/or treatment with the non-steroidal anti-inflammatory drug (NSAID) sulindac suppresses the protumor effects of obesity in a mouse model of colon cancer. Azoxymethane-treated male FVB/N mice were fed a low-fat diet (LFD) or high-fat diet (HFD) for 15 weeks, then HFD mice were randomized to remain on HFD (obese) or switch to LFD (formerly obese (FOb-LFD)). Within the control (LFD), obese, and FOb-LFD groups, half the mice were also randomized to start sulindac treatment (140 ppm in the diet). All mice were euthanized seven weeks later. FOb-LFD mice had intermediate levels of body weight, lower than obese but higher than control mice (P<0.05). Sulindac did not affect body weight. Obese mice had greater tumor multiplicity and burden than all other groups (P<0.05). Transcriptomic profiling indicated that both weight loss and sulindac modulate the expression of tumor genes related to invasion and may promote a more anti-tumor immune landscape. Furthermore, the fecal microbes Prevotella and Akkermansia muciniphila, both known to be elevated in colorectal cancer patients, were positively correlated with tumor multiplicity and reduced by sulindac in obese mice. In sum, either moderate weight loss or sulindac treatment completely reversed the effects of chronic obesity on colon tumorigenesis. Our findings suggest that an investigation regarding the effects of NSAID treatment on colon cancer risk and/or progression in obese individuals is warranted, particularly for those unable to achieve moderate weight loss.
Project description:The development of biomarkers that can predict viral rebound following discontinuation of antiretroviral therapy (ART) in HIV-1-infected humans would be an important advance in HIV-1 cure research. In a prior study, we initiated ART in 20 rhesus macaques on days 0, 1, 2, and 3 following SIVmac251 infection prior to plasma viremia1. Following 6 months of suppressive ART, we discontinued ART and observed viral rebound in 9 of 20 animals. Here we show that transcriptomic and proteomic signatures of inflammation and immune activation in peripheral blood during ART suppression predicted viral rebound following ART discontinuation. Higher levels of proinflammatory and cellular immune activation pathways, including TNF, IL-1, IL-6, monocyte, and T cell activation signaling pathways, correlated with viral rebound following ART discontinuation. Immune modulatory IL-10 and TGF-b signaling also correlated with viral rebound. We then validated these candidate biomarkers of viral rebound in a second cohort of SIV-infected, ART-suppressed macaques. Taken together, these data suggest that persistent upregulation of inflammatory and immune activation pathways despite suppressive ART may represent a peripheral blood biomarker signature of the rebound-competent viral reservoir. The development of interventions that target the viral reservoir and modulate this signature may open new avenues in HIV-1 cure research.
Project description:Emerging data suggest that some high-risk subjects benefit more than others from preventive intervention. The goal of this study was to determine the efficacy of sulindac (Sul) and/or atorvastatin (Atorva) against spontaneous colorectal adenomas in Apc+/Min-FCCC mice in which the tumor-bearing status was known at the time of treatment initiation. Administration of Sul/Atorva to tumor-bearing mice led to a 43% reduction in the multiplicity of colorectal adenomas as compared to that of untreated tumor-bearing mice. Atorvastatin completely inhibited the formation of microadenomas in mice that were tumor-free at baseline, with associated decreases in the expression of inflammatory mediators observed. Expression of Hoxb13 and Rprm was enhanced significantly following Sul/Atorva treatment, suggesting the importance of cell cycle regulation in colon tumor inhibition. The tumor status of animals at treatment initiation dictates response to atorvastatin, sulindac and Sul/Atorva. The tumor inhibition observed with Sul/Atorva in tumor-bearing mice was greater than that achieved with either agent alone.
Project description:Folic acid supplementation (8 mg/kg diet) promotes colon tumor formation in mice with established colitis induced by carcinogen azoxymethane (AOM) and dextran sulfate sodium sulfate (DSS). This induction of colon tumors was associated with hypomethylation of DNA cased by folic acid supplementation.
Project description:Folic acid supplementation (8 mg/kg diet) promotes colon tumor formation in mice with established colitis induced by carcinogen azoxymethane (AOM) and dextran sulfate sodium sulfate (DSS). This induction of colon tumors was associated with hypomethylation of DNA cased by folic acid supplementation.
Project description:Application of a mass spectrometry -based approach to assess the gut microbiota composition and the associated metaproteomic functionality of subjects exposed to simulated microgravityduring the Artificial Gravity Bed Rest study (AGBRESA)