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Riffey, O. F.

Publications and source records attributed to Riffey, O. F..

2 recordsLinked to original sources

Requirement of hypoxia-inducible factor 1 alpha for interleukin 1 beta induced glycolysis in colorectal cancer cells

Colorectal cancer cells increase glycolysis to help meet the metabolic demands required for cell growth. Many factors, both endogenous and exogenous, likely drive cellular metabolism and enhance glycolytic flux in colorectal cells. Interleukin-1 beta (IL-1{beta}) is a pro-inflammatory cytokine that is elevated in colorectal cancer. In this study, we investigated the effect of IL-1{beta} toward driving the cancer cell to increase glycolysis, while also suppressing the oxidation of the fiber-derived nutrient butyrate. The results presented here demonstrate that IL-1{beta} stimulated glycolysis and inhibited maximal mitochondrial respiration. IL-1{beta} also increased the phosphorylation of AKT and hypoxia-inducible factor 1 alpha (HIF1) levels. Utilizing colorectal cancer cells with AKT1/2 or HIF1 knocked out showed the requirement of these proteins in mediating the increase in glycolysis following IL-1{beta} treatment. Importantly, AKT1/2 was identified as upstream of HIF1, as IL-1{beta} still increased phosphorylation of AKT even in the absence of HIF1. However, loss of AKT1/2 completely abolished the ability of IL-1{beta} to increase HIF1 protein levels. Tumor necrosis factor alpha (TNF), another cytokine found to be elevated in colorectal cancer, also increased glycolysis in an AKT and HIF1-dependent manner. Our data point to a common pathway through AKT activation and HIF1 upregulation, by which pro-inflammatory cytokines increase glycolysis in colorectal cancer cells to help promote cancer progression.

cell biology↗

Inflammation is the Driver of Butyrate-Producing Bacteria Change in Interleukin10 Knockout Mice

BackgroundAlterations of gut microbiota have been implicated in the development of inflammatory bowel disease. Specifically, patients with IBD show the reduced levels of gut bacteria to produce butyrate, a crucial metabolite for maintaining gut homeostasis, along with decreased levels of fecal butyrate. However, there is limited research on changes in butyrate-producing bacteria at various taxonomic levels during the development of inflammatory bowel disease. ResultsWe investigated the changes of butyrate-producing bacteria in interleukin10 knockout mice, a suitable IBD model, as these mice require gut microbiota to develop spontaneous chronic colitis. Our findings indicate increased inflammation and a metabolic shift from butyrate oxidation toward glycolysis in 9-week-old interleukin10 knockout mice. Furthermore, we observed significant changes in two terminal enzymes involved in butyrate production: a significant increase of butyrate kinase and a significant decrease of butyryl-CoA:acetate-CoA-transferase. These observations align with an increased abundance of Coprococcus comes, which utilizes butyrate kinase, and a decreased abundance of Faecalibacterium prausnitzii that utilizes butyryl-CoA:acetate-CoA-transferase. Moreover, reduced levels of acetate, a necessary co-substrate for butyryl-CoA:acetate-CoA-transferase activity, were observed in interleukin10 knockout mice. ConclusionsThese findings enhance our understanding of changes in butyrate-producing bacteria populations at various taxonomic levels, ranging from phylum to gene level in 9-week-old interleukin10 knockout mice. Furthermore, these data suggest a potential for diagnosing IBD at an early stage by analyzing the composition of butyrate-producing bacteria.

microbiology↗