Lactate transport and metabolism in rumen epithelial cells in SARA condition

Abstract

Lactate, a main product of rumen microbial fermentation from dietary starch, has been recognised as an important mediator of rumen microbiota regulation in rumen acidosis. However, the mechanism of lactate transport and metabolism in the rumen remains unclear. This study aimed to evaluate the significance of the absorption, transport, and metabolism of lactic acid in the pH and LPS-induced subacute ruminal acidosis (SARA) model of rumen epithelial cells (RECs). In the current study, RECs were obtained from two adult Saanen goats (44.5 ± 4.6 kg BW) and using Lipopolysaccharide (LPS) and low pH to co-stimulate RECs to construct a microenvironment under SARA conditions, to further analyse the lactate transport and metabolism by RECs. The results showed that the LPS and low pH could significantly reduce cell viability by 29.36% (p < 0.05), induce inflammation in RECs, destroy tight junctions between RECs, and increase cell permeability. In addition, stimulation leads to changes in cellular metabolic activity and inhibits the expression of lactate transporters (p < 0.05), promoting an increased risk of lactate accumulation in the intracellular and intestinal lumen. This study hopefully provides a better understanding of lactate metabolic regulation and new perspectives for the nutritional prevention and treatment of SARA.

HIGHLIGHTS

• Lactic acid is an important fermentation product in the rumen of ruminants, and its transport and metabolic regulation mechanisms are still unclear.

• To understand transport uptake in the rumen epithelium, a SARA model was therefore used.

• Low pH and high LPS trigger epithelial inflammation, increasing the risk of lactic acid entering the bloodstream.

Keywords:

• Subacute rumen acidosis
• transformation
• rumen epithelial cells
• monocarboxylate transporters
• goats

Acknowledgements

The authors would like to acknowledge Prof. Hongrong Wang from Yangzhou University for his help and advice in the design of the study and laboratory analysis of the samples and thank the laboratory staff in the Laboratory of Metabolic Manipulation of Herbivorous Animal Nutrition for their assistance.

Author contributions

The contribution of the authors were as follows; conceptualisation of experiment and funding acquisition, HRW, laboratory analysis; BLH, YTF, XJZ writing of original draft; BLH, review and editing; HRW and YTF. All authors have read and approved the final manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data generated and/or analysed during this study are available from the corresponding author upon reasonable request.

Additional information

Funding

This research was funded by the National Natural Science Foundation of China [NSFC No. 31872988, No. 31572429], and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PADA).