Subacute ruminal acidosis suppressed the expression of MCT1 in rumen of cows

Abstract

Subacute ruminal acidosis (SARA) is characterized by the depression of ruminal pH and an increase in the concentrations of short‐chain fatty acids (SCFAs) and lipopolysaccharide (LPS) in the rumen of cows. The onset of SARA was linked to the accumulation of SCFAs. However, the mechanism of SCFAs transport is unknown. The proton‐linked monocarboxylate transporter (MCT1) plays a vital role in the transportation of SCFAs. The goal of this study was to elucidate the distribution of MCT1 along the gastrointestinal tract of calves and adult cows; the expression change of MCT1 in SARA cows and the effect of ruminal pH, SCFAs, and LPS on MCT1 expression in rumen epithelial cells in vitro. The results indicated the presence of MCT1 along the gastrointestinal tract of calves and adult cows, most abundantly expressed in the rumen. Importantly, the expression of MCT1 was decreased in the rumen epithelium of SARA cows, and the expression of MCT1 was restored in the SARA treatment group. In vitro, LPS, low rumen fluid pH, high concentrations of SCFAs (90 mM acetate, 40 mM propionate, and 30 mM butyrate), and high concentrations of acetate, propionate, and butyrate, respectively, inhibited the expression of MCT1 in rumen epithelial cells. Taken together, these results indicated that LPS, low ruminal pH, and high concentrations of SCFAs decreased the expression of MCT1, further aggravating the accumulation of SCFAs in the rumen by decreasing the absorption of SCFAs.

Comparison of Rumen Microbiota and Serum Biochemical Indices in White Cashmere Goats Fed Ensiled or Sun-Dried Mulberry Leaves

“…The effect of rumen pH on the production of VFA is mainly reflected by the effect on rumen microbial activity [ 47 ]. Rumen bacteria convert dietary fiber into VFAs, which provide energy and improve health [ 48 ]. As expected, the concentration of butyrate had an increasing trend when a typical TMR was supplemented with mulberry leaves.…”

Ruminal epithelial cell proliferation and short-chain fatty acid transporters in vitro are associated with abundance of period circadian regulator 2 (PER2)

“…Primary REC were harvested from ruminal tissue of 3 weaned Boer goats (2 mo of age; ~10 kg of BW) using the serial trypsin digestion method (Baldwin and Jesse, 1991) with some modifications of the culture medium. Although we did not perform a power test, it was deemed that 3 animals would provide sufficient power for detecting statistical differences in terms of molecular analyses based on a previous similar study (Zhao et al, 2019). The isolated REC were cultured in Dulbecco's modified Eagle medium (DMEM)/ Nutrient Mixture F-12 (Thermo Fisher Scientific, Waltham, MA) supplemented with 5% fetal bovine serum (Thermo Fisher Scientific), 200 U/mL penicillin (P0389; Sigma-Aldrich, St. Louis, MO), 0.2 mg/mL streptomycin (S6501; Sigma-Aldrich), 0.1 mg/mL gentamicin, 5 μg/mL amphotericin B (Solarbio, Beijing, China), 1% insulin-transferrin-selenium solution (Thermo Fisher Scientific), and 10 ng/mL epidermal growth factor (Peprotech, Rocky Hill, NJ).…”

Adaptive responses in short-chain fatty acid absorption, gene expression, and bacterial community of the bovine rumen epithelium recovered from a continuous or transient high-grain feeding

“…Additionally, the rumen epithelial (epimural) bacteria were shown to be less stable due to transient feeding (Wetzels et al, 2016), and that long-term continuously challenged epithelial microbes are significantly reduced in diversity (Wetzels et al, 2017). There are indications that the rumen epithelium elicits an adaptive response to high-grain feeding at the gene expression level by increasing barrier function (McCann et al, 2016), changing the expression of SCFA transporters and rumen epithelial cell metabolism enzymes (Laarman et al, 2013;Zhao et al, 2019), as well as inflammation-related gene expression (Zhang et al, 2016). The sensitivity of the epithelial bacterial community to changes in the diet (Petri et al, 2013a) as well as an effect of the host on the rumen microbial community (Weimer et al, 2010) might be associated with the involvement in barrier function, localized immune response, as well as SCFA transport.…”