Our objective was to evaluate the effects of heat stress (HS) and dietary organic acid and pure botanical (OA/PB) supplementation on measures of hepatic inflammation and oxidative stress. Following a 7 d acclimation in thermoneutrality (temperature-humidity index [THI] 68), 46 Holstein cows were randomly assigned to 1 of 4 groups: thermoneutral conditions (TN-Con, n = 12), HS conditions (HS-Con, n = 12; diurnal THI 74 to 82), TN conditions pair-fed to match HS-Con (TN-PF, n = 12), or HS fed OA/PB (HS-OAPB, n = 10; 75 mg/kg of body weight; 25% citric acid, 16.7% sorbic acid, 1.7% thymol, 1.0% vanillin, and 55.6% triglyceride; AviPlus R; Vetagro S.p.A) for 14 d. Plasma was collected on d −1, 3, 7, and 14 and analyzed for serum-amyloid A (SAA) and reduced glutathione (GSH) concentrations. Liver was biopsied on d 12 and analyzed by transcriptomics (RNA-Seq). Data were analyzed using a mixed model including random effect of cow, and the fixed effects of treatment, time, and their interaction. Planned contrasts included HS-Con vs. TN-Con, HS-Con vs. TN-PF, and HS-Con vs. HS-OAPB. HS-Con had greater concentrations in plasma SAA (P < 0.01) and GSH (P < 0.08) concentrations relative to TN-Con, TN-PF, or HS-OAPB. Hepatic expression of genes related to inflammatory signaling (MYD88, SAA3, and NFKb1), were increased in HS-Con relative to TN-Con and TN-PF (P < 0.01) and HS-OAPB (P < 0.12). HS-OAPB tended to downregulate the initial enzyme in the transulfuration pathway (CBS; P = 0.06), while upregulated glutathione peroxidase 1 (GPX1; P = 0.01), relative to HS-Con. HS-Con overexpressed the taurine pathway (CDO1), relative to all treatments (P < 0.05). Regarding transmethylation pathway genes; AHCY and BHMT were upregulated in HS-Con compared with TN-Con and TN-PF (P < 0.01) and HS-OAPB (P < 0.07), while CHDH and MAT1A were downregulated in TN-PF compared with HS-Con (P < 0.01). Phosphatydilcholine degradation through GDPD5 was downregulated in HS-Con compared with all treatments (P < 0.04). Observed alterations at gene level may explain HS detrimental effects and suggest OA/PB supplementation as a means to improve hepatic health and metabolism.
V. Sáinz de la Maza Escolà, G.L. (2023). Effects of heat stress and dietary organic acid and pure botanical on hepatic transcriptome..
Effects of heat stress and dietary organic acid and pure botanical on hepatic transcriptome.
V. Sáinz de la Maza EscolàPrimo
Writing – Review & Editing
;F. GhiselliMembro del Collaboration Group
;E. GrilliPenultimo
Supervision
;
2023
Abstract
Our objective was to evaluate the effects of heat stress (HS) and dietary organic acid and pure botanical (OA/PB) supplementation on measures of hepatic inflammation and oxidative stress. Following a 7 d acclimation in thermoneutrality (temperature-humidity index [THI] 68), 46 Holstein cows were randomly assigned to 1 of 4 groups: thermoneutral conditions (TN-Con, n = 12), HS conditions (HS-Con, n = 12; diurnal THI 74 to 82), TN conditions pair-fed to match HS-Con (TN-PF, n = 12), or HS fed OA/PB (HS-OAPB, n = 10; 75 mg/kg of body weight; 25% citric acid, 16.7% sorbic acid, 1.7% thymol, 1.0% vanillin, and 55.6% triglyceride; AviPlus R; Vetagro S.p.A) for 14 d. Plasma was collected on d −1, 3, 7, and 14 and analyzed for serum-amyloid A (SAA) and reduced glutathione (GSH) concentrations. Liver was biopsied on d 12 and analyzed by transcriptomics (RNA-Seq). Data were analyzed using a mixed model including random effect of cow, and the fixed effects of treatment, time, and their interaction. Planned contrasts included HS-Con vs. TN-Con, HS-Con vs. TN-PF, and HS-Con vs. HS-OAPB. HS-Con had greater concentrations in plasma SAA (P < 0.01) and GSH (P < 0.08) concentrations relative to TN-Con, TN-PF, or HS-OAPB. Hepatic expression of genes related to inflammatory signaling (MYD88, SAA3, and NFKb1), were increased in HS-Con relative to TN-Con and TN-PF (P < 0.01) and HS-OAPB (P < 0.12). HS-OAPB tended to downregulate the initial enzyme in the transulfuration pathway (CBS; P = 0.06), while upregulated glutathione peroxidase 1 (GPX1; P = 0.01), relative to HS-Con. HS-Con overexpressed the taurine pathway (CDO1), relative to all treatments (P < 0.05). Regarding transmethylation pathway genes; AHCY and BHMT were upregulated in HS-Con compared with TN-Con and TN-PF (P < 0.01) and HS-OAPB (P < 0.07), while CHDH and MAT1A were downregulated in TN-PF compared with HS-Con (P < 0.01). Phosphatydilcholine degradation through GDPD5 was downregulated in HS-Con compared with all treatments (P < 0.04). Observed alterations at gene level may explain HS detrimental effects and suggest OA/PB supplementation as a means to improve hepatic health and metabolism.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
