High-fat diet affects autophagy and mitochondrial compartment in rat Harderian gland.
Gabriella Chieffi BaccariSara FalvoMaria M Di FioreFederica CioffiAntonia GiaccoAlessandra SantilloPublished in: Journal of experimental zoology. Part A, Ecological and integrative physiology (2022)
The Harderian gland (HG) of Rattus norvegicus is an orbital gland secreting lipids that accumulate in excess under condition of increased lipid metabolism. To study the response elicitated by lipid overload in rat HG, we housed the animals in thermoneutral conditions (28-30°C) in association to high fat diet (HFD). In HFD rats alterated blood lipid levels result in lipid accumulation in HG as demonstrated by the increased gland weight and histochemical/ultrastructural analyses. The HFD-caused oxidative stress forces the gland to trigger antioxidant defense mechanisms and autophagic process, such as lipophagy and mitophagy. Induction of mitochondrial DNA (mtDNA) damage and repair was stronger in HFD-rat HGs. An increase in marker expression levels of mitochondrial biogenesis, fission, and fusion occurred to counteract mtDNA copy number reduction and mitophagy. Therefore, the results demonstrate that rat HG activates autophagy as survival strategy under conditions of increased lipid metabolism and suggest a key role for mitophagy and membrane dynamics in the mitochondrial adaptive response to HFD.
Keyphrases
- high fat diet
- oxidative stress
- mitochondrial dna
- copy number
- adipose tissue
- insulin resistance
- ischemia reperfusion injury
- dna damage
- diabetic rats
- fatty acid
- induced apoptosis
- genome wide
- fluorescent probe
- cell death
- physical activity
- living cells
- body mass index
- nlrp inflammasome
- type diabetes
- weight loss
- endoplasmic reticulum stress
- gene expression
- metabolic syndrome
- long non coding rna