Potential Role of SLC5A8 Expression in the Etiology of Subacute Ruminal Acidosis

Abstract

Rumen fluid of cows with subacute ruminal acidosis (SARA) has high concentrations of short chain fatty acids (SCFA). However, the mechanism of SCFA accumulation is unknown. The solute-linked carrier 5a8 (SLC5A8) plays a key role in the transportation and absorption of SCFA in the intestinal epithelium. The objective of the current study was to investigate (1) SLC5A8 gene and protein expression in various parts of the bovine gastrointestinal tract, (2) the effect of SCFA on SLC5A8 expression in rumen epithelial cells, and (3) SLC5A8 gene and protein expression in SARA and healthy cows. A total of 10 dairy cows, 84 ± 26 days in milk and in their second to fourth parity were allocated to control ( n = 5) and SARA groups ( n = 5). Three cows from the control group and three calves (1-day-old, female, 45–50 kg, healthy, fasting) were chosen to collect a total of 10 sections of digestive tract, from rumen to rectum, and then bovine ruminal epithelial cells were isolated from the three calves. Gene and protein expression of SLC5A8 was detected in all tested regions of the gastrointestinal tract in calves and adult cows by Western blot and quantitative real-time PCR and were both highest in the rumen. Gene and protein expression of SLC5A8 was more than 50% lower in the rumen epithelium of SARA vs. control cows and was partly restored after therapy of SARA cows. Compared with SCFA concentrations typical for control cows (60 m M acetate, 30 m M propionate, and 20 m M butyrate), gene and protein expression of SLC5A8 in rumen epithelium was lower at elevated SCFA concentrations typical for SARA cows (90 m M acetate, 40 m M propionate, and 30 m M butyrate), specifically for elevated concentrations of propionate or butyrate in contrast to elevated concentrations of acetate increased gene and protein expression of SLC5A8 in rumen epithelium. In conclusion, the elevated concentrations of propionate and butyrate inhibit ruminal absorption of SCFA via downregulation of SLC5A8 in SARA cows; the expression of SLC5A8 plays an important role in the etiology of SARA.

Sodium Propionate Relieves LPS-Induced Inflammation by Suppressing the NF-ĸB and MAPK Signaling Pathways in Rumen Epithelial Cells of Holstein Cows

“…Rumen epithelium was separated by ophthalmic micro-tweezers on the sterile operation table. The technique of isolating and culturing RECs has already been described in detail [ 69 ]. In brief, tissues were washed three times with 4 °C sterile saline and shredded with ophthalmic scissors.…”

Transcriptome Analysis Reveals Age-Specific Growth Characteristics in the Rumen of Hanwoo (Korean Native Cattle) Steers

“…This disruption in rumen acidity balance can trigger subacute rumen acidosis (SARA), which is implicated in various digestive disorders including indigestion and diarrhea (21). Similarly, decreased expression of SLC5A8 contributes to the onset of SARA by impeding the absorption of short-chain fatty acids (SCFA), a type of VFA, from the rumen (22). After Hanwoo reach an age of approximately 14 months, there is a gradual increase in the proportion of concentrated feed they are given.…”

Strontium attenuates LPS-induced inflammation via TLR4/MyD88/NF-κB pathway in bovine ruminal epithelial cells

“…The rumen tissue was collected from newborn Holstein male calves (n = 3, 38.0 ± 2.8 kg body weight) within 15 min after euthanasia, and serial trypsin digestions were used to isolate primary bovine ruminal epithelial cells as previously described [24][25][26]. Brie y, the collected rumen tissue was washed several times with PBS containing antibiotics, and cut into small pieces (about 0.25cm 2 ).…”