Metabolic Reprogramming and Inflammatory Response Induced by D-Lactate in Bovine Fibroblast-Like Synoviocytes Depends on HIF-1 Activity

John Quiroga; Pablo Alarcón; Carolina Manosalva; Stefanie Teuber; Anja Taubert; Carlos Hermosilla; María Angélica Hidalgo; María Daniella Carretta; Rafael Agustín Burgos

doi:10.3389/fvets.2021.625347

Metabolic Reprogramming and Inflammatory Response Induced by D-Lactate in Bovine Fibroblast-Like Synoviocytes Depends on HIF-1 Activity

Front Vet Sci. 2021 Mar 16:8:625347. doi: 10.3389/fvets.2021.625347. eCollection 2021.

Authors

John Quiroga^{1

2}, Pablo Alarcón^{1

2}, Carolina Manosalva³, Stefanie Teuber^{1

2}, Anja Taubert⁴, Carlos Hermosilla⁴, María Angélica Hidalgo^{1

2}, María Daniella Carretta^{1

2}, Rafael Agustín Burgos^{1

2}

Affiliations

¹ Laboratory of Inflammation Pharmacology, Faculty of Veterinary Sciences, Institute of Pharmacology and Morphophysiology, Universidad Austral de Chile, Valdivia, Chile.
² Laboratory of Immunometabolism, Faculty of Veterinary Sciences, Institute of Pharmacology and Morphophysiology, Universidad Austral de Chile, Valdivia, Chile.
³ Faculty of Sciences, Institute of Pharmacy, Universidad Austral de Chile, Valdivia, Chile.
⁴ Biomedical Research Center Seltersberg, Institute of Parasitology, Justus Liebig University Giessen, Giessen, Germany.

Abstract

Acute ruminal acidosis (ARA) occurs after an excessive intake of rapidly fermentable carbohydrates and is characterized by the overproduction of D-lactate in the rumen that reaches the bloodstream. Lameness presentation, one of the primary consequences of ARA in cattle, is associated with the occurrence of laminitis and aseptic polysynovitis. Fibroblast-like synoviocytes (FLS) are predominant cells of synovia and play a key role in the pathophysiology of joint diseases, thus increasing the chances of the release of pro-inflammatory cytokines. Increased D-lactate levels and disturbances in the metabolism of carbohydrates, pyruvates, and amino acids are observed in the synovial fluid of heifers with ARA-related polysynovitis prior to neutrophil infiltration, suggesting an early involvement of metabolic disturbances in joint inflammation. We hypothesized that D-lactate induces metabolic reprogramming, along with an inflammatory response, in bovine exposed FLS. Gas chromatography-mass spectrometry (GC-MS)-based metabolomics revealed that D-lactate disrupts the metabolism of bovine FLS, mainly enhancing glycolysis and gluconeogenesis, pyruvate metabolism, and galactose metabolism. The reverse-transcription quantitative PCR (RT-qPCR) analysis revealed an increased expression of metabolic-related genes, including hypoxia-inducible factor 1 (HIF-1)α, glucose transporter 1 (Glut-1), L-lactate dehydrogenase subunit A (L-LDHA), and pyruvate dehydrogenase kinase 1 (PDK-1). Along with metabolic disturbances, D-lactate also induced an overexpression and the secretion of IL-6. Furthermore, the inhibition of HIF-1, PI3K/Akt, and NF-κB reduced the expression of IL-6 and metabolic-related genes. The results of this study reveal a potential role for D-lactate in bFLS metabolic reprogramming and support a close relationship between inflammation and metabolism in cattle.

Keywords: D-lactate; bovine fibroblast-like synoviocyte; hypoxia inducible factor 1; inflammation; metabolic reprogramming.