Sirt3 Restores Lipid Homeostasis in Bovine Hepatocytes Exposed to NEFA
Bibliographic record
Abstract
Introduction Sirt3, a major deacetylase in mitochondria, plays a pivotal role in the regulation of lipid metabolism in mice and humans. Dynamic changes of Sirt3 expression are observed in ruminants during the transition period, a time when fat mobilization initiates and non‐esterified fatty acids (NEFA) sore in plasma, and also a time when most of lipid metabolism disorders in ruminants take place, like fatty liver and ketosis etc. However, the rationale between Sirt3 and fat metabolism disturbance in dairy cows has not been characterized yet. The current study aims to investigate interrelations of Sirt3 and NEFA on expressions of key factors involved in fat metabolism in bovine hepatocytes. Methods Hepatocytes from a calf were isolated, and primarily cultured by a modified 2 steps of collagenase perfusion method. NEFA ranging from 0 mM to 1.2 mM were added, and their effects on the expression of Sirt3 was studied. Sirt3 overexpression was induced by adenovirus (AdMAX system), and expressions of key fat metabolism factors, namely acetyl‐CoA carboxylase‐1 (ACC‐1), fatty acid synthase (FAS), carnitine palmitoyltransterase‐1 (CPT‐1), CPT‐2, acyl‐CoA oxidase (ACO), apolipoprotein B (ApoB) and ApoE were investigated. The level of supernatant very low‐density lipoprotein (VLDL) content and cellular triacylglycerol (TG) contents were also measured. Then 1.2 mM NEFA and Sirt3 overexpression vectors were co‐incubated with hepatocytes. All above mentioned parameters were also tested. Results The mRNA level of Sirt3 was significantly up‐regulated by 0.3 mM NEFA, but was significantly down‐regulated by 1.2 mM NEFA ( p <0.01). Sirt3 overexpression significantly induced expressions of ACC‐1, CPT‐1, CPT‐2, ACO, ApoB and ApoE ( p <0.01), and elevated cellular TG contents ( p <0.01). However, Ad‐Sirt3 treatment did not change mRNA level of FAS and supernatant VLDL level compared with controls. Ad‐Sirt3 + 1.2 mM NEFA treatment increased the mRNA level of Sirt3 by 4‐fold compared to Ad‐GFP controls ( p <0.01), and regained expressions of CPT‐1, CPT‐2 and ACO previous inhibited by 1.2 mM NEFA. Moreover, cellular TG contents were lowered in Ad‐Sirt3 + 1.2 mM NEFA group compared 1.2 mM NEFA treatments ( p <0.01). Conclusion Those data indicated that Sirt3 was involved in the regulation of lipid metabolism in bovine hepatocytes exposed to high level NEFA by restoring lipid homeostasis. Further investigations are needed to explore the potential role of Sirt3 as a therapeutic target for maintenance of perinatal health in dairy cows. Support or Funding Information This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".