Butyrate Alters Pyruvate Flux and Induces Lipid Accumulation in Cultured Colonocytes

Abstract

Butyrate is considered the primary energy source of colonocytes and has received wide attention due to its unique health benefits. Insight into the mechanistic effects of butyrate on cellular and metabolic function relies mainly on research in in-vitro-cultured cells. However, cells in culture differ from those in vivo in terms of metabolic phenotype and nutrient availability. For translation, it is therefore important to understand the impact of different nutrients on the effects of butyrate. We investigated the metabolic consequences of butyrate exposure under various culturing conditions, with a focus on the interaction between butyrate and glucose. To investigate whether the effects of butyrate were different between cell­­s with high and low mitochondrial capacity, we cultured HT29 cells under either low- (0.5 mM) or high- (25 mM) glucose conditions. Low-glucose culturing increased the mitochondrial capacity of HT29 cells compared to high-glucose (25 mM) cultured HT29 cells. Long-term exposure to butyrate did not alter mitochondrial bioenergetics, but it decreased glycolytic function, regardless of glucose availability. In addition, both high- and low-glucose-grown HT29 cells showed increased lipid droplet accumulation following long-term butyrate exposure. Acute exposure of cultured cells (HT29 and Caco-2) to butyrate increased their oxygen consumption rate (OCR). A simultaneous decrease in extracellular acidification rate (ECAR) was observed. Furthermore, in the absence of glucose, OCR did not increase in response to butyrate. These results lead us to believe that butyrate itself was not responsible for the observed increase in OCR, but, instead, butyrate stimulated pyruvate flux into mitochondria. Indeed, blocking of the mitochondrial pyruvate carrier prevented a butyrate-induced increase in oxygen consumption. Taken together, our results indicate that butyrate itself is not oxidized in cultured cells but instead alters pyruvate flux and induces lipid accumulation.

Lacticaseibacilli attenuated fecal dysbiosis and metabolome changes in Candida-administered bilateral nephrectomy mice

“…Here, indoxyl sulfate, a gut-derived uremic toxin was used as a representative toxin for the in vitro test in enterocyte cell lines. As such, an impact of butyrate on uremic toxin (indoxyl sulfate)-stimulated enterocytes was demonstrated in vitro (enterocyte integrity and anti-inflammation) along with the increased enterocyte cell energy supporting a previous publication ( 93 ). The administration of butyrate as a chemical drug is interesting due to an easier production process than probiotic preparation; however, the proper dose adjustment will be necessary as butyrate toxicity is possible ( 94 , 95 ).…”

Short-chain fatty acids reprogram metabolic profiles with the induction of reactive oxygen species production in human colorectal adenocarcinoma cells

“…In addition to regulating glutamine metabolism, MYC modulates aerobic glycolysis by promoting glucose uptake (by enhancing glucose transporter SLC2A1 expression [95] ), activating the production of pyruvate (by elevating PKM expression [96] ), and modulating lactate export (by inducing lactate transporters-monocarboxylate transporters MCT1 and MCT2 [97] ). First, butyrate treatment increases glucose uptake in Caco-2 cells [98] . In this study, we also observed elevated glucose and altered expression of GLUT genes in SCFA-treated Caco-2 cell lines, including increased insulin-regulated gene GLUT4 ( SLC2A4 ) and decreased expression of non-insulin-dependent genes GLUT2 ( SLC2A2 ) and GLUT9 ( SLC2A9 ), which is in contrast with previous reports on increased gene expression of GLUT2 in SCFA-treated cells [99] , [100] .…”

Microbial metabolite butyrate modulates granzyme B in tolerogenic IL-10 producing Th1 cells to regulate intestinal inflammation

“… 17 In addition, butyrate has been reported to affect cellular metabolic patterns in several cell types, including colonocytes, CD8 + T cells, and CD4 + T cells. 18–20 We then investigated whether butyrate modulates Th1 cell metabolism, especially mitochondrial oxidation and glycolysis, to promote GzmB production. We activated CD4 + T cells with αCD3 mAb and αCD28 mAb under Th1 conditions in the presence or absence of butyrate for 24 h and measured the oxygen consumption rate (OCR), which is primarily attributed to mitochondrial oxidation, and the extracellular acidification rate (ECAR) that represents glycolysis, by using an extracellular flux Seahorse analyzer.…”