Reveal genes functionally associated with ACADS by a network study

Aging-induced short-chain acyl-CoA dehydrogenase promotes age-related hepatic steatosis by suppressing lipophagy

Hepatic steatosis, the first step in the development of nonalcoholic fatty liver disease (NAFLD), is frequently observed in the aging population. However, the underlying molecular mechanism remains largely unknown. In this study, we first employed GSEA enrichment analysis to identify short-chain acyl-CoA dehydrogenase (SCAD), which participates in the mitochondrial β-oxidation of fatty acids and may be associated with hepatic steatosis in elderly individuals. Subsequently, we examined SCAD expression and hepatic triglyceride content in various aged humans and mice and found that triglycerides were markedly increased and that SCAD was upregulated in aged livers. Our further evidence in SCAD-ablated mice suggested that SCAD deletion was able to slow liver aging and ameliorate aging-associated fatty liver. Examination of the molecular pathways by which the deletion of SCAD attenuates steatosis revealed that the autophagic degradation of lipid droplets, which was not detected in elderly wild-type mice, was maintained in SCAD-deficient old mice. This was due to the decrease in the production of acetyl-coenzyme A (acetyl-CoA), which is abundant in the livers of old wild-type mice. In conclusion, our findings demonstrate that the suppression of SCAD may prevent age-associated hepatic steatosis by promoting lipophagy and that SCAD could be a promising therapeutic target for liver aging and associated steatosis.

Identification and Functional Analysis of BmNPV-Interacting Proteins From Bombyx mori (Lepidoptera) Larval Midgut Based on Subcellular Protein Levels

Bombyx mori nucleopolyhedrovirus (BmNPV) is a major pathogen causing severe economic loss. However, the molecular mechanism of silkworm resistance to BmNPV and the interactions of this virus with the host during infection remain largely unclear. To explore the virus-binding proteins of silkworms, the midgut subcellular component proteins that may interact with BmNPV were analyzed in vitro based on one- and two-dimensional electrophoresis and far-western blotting combined with mass spectrometry (MS). A total of 24 proteins were determined to be specifically bound to budded viruses (BVs) in two subcellular fractions (mitochondria and microsomes). These proteins were involved in viral transportation, energy metabolism, apoptosis and viral propagation, and they responded to BmNPV infection with different expression profiles in different resistant strains. In particular, almost all the identified proteins were downregulated in the A35 strain following BmNPV infection. Interestingly, there were no virus-binding proteins identified in the cytosolic fraction of the silkworm midgut. Two candidate proteins, RACK1 and VDAC2, interacted with BVs, as determined with far-western blotting and reverse far-western blotting. We speculated that the proteins interacting with the virus could either enhance or inhibit the infection of the virus. The data provide comprehensive useful information for further research on the interaction of the host with BmNPV.

Exploration of targets regulated by miR-125b in porcine adipocytes

MicroRNA (miRNA) has been proved to play a key role in lipid metabolism. In our previous study, miR-125b was validated to be differentially expressed in preadipocytes and adipocytes, which was also proved to involve in lipid metabolism. To explore the comprehensive targets of miR-125b in adipocytes, isobaric tag for relative and absolute quantitation (iTRAQ) analysis was performed to obtain differentially expressed proteins in adipocytes comparing negative control (NC) and miR-125b mimic, combining with digital gene expression (DGE) profiling of mRNA incorporated into RNA-induced silencing complex (RISC) pulled down by biotinylated miR-125b mimic and targets prediction of miR-125b by three algorithms, acyl-CoA dehydrogenase short chain (ACADS) and mitochondrial trans-2-enoyl-CoA reductase (MECR) were screened out as miR-125b direct targets. Luciferase reporter assay further validated that miR-125b mimic significantly inhibited the luciferase activity by targeting wild type (WT) 3'-UTR compared with NC. qPCR analysis of ACADS and MECR mRNA from adipose tissues of miR-125b knockout (KO) mice further confirmed the inhibition of miR-125b on ACADS and MECR expressions. Here we report miR-125b play a vital role in maintaining homeostasis of fatty acid metabolism by targeting key enzyme ACADS and MECR in the process of fatty acid elongation and degradation.

Dietary fish oil supplementation alters liver gene expressions to protect against LPS-induced liver injury in weanling piglets

Here, the potential mechanisms of the protective effects of fish oil against LPS-induced liver injury in a piglet model were investigated by using RNA sequencing. Twenty-four piglets were used in a 2 × 2 factorial design, and the main factors included diet (5% corn oil or 5% fish oil) and immunological challenge (LPS or saline, on d 19). All piglets were slaughtered at 4 h after challenge, and liver samples were collected. Fish oil improved liver morphology and reduced TNF-α, IL-1β and IL-6 productions after LPS challenge. RNA sequencing analysis showed fish oil had significant effect on the expressions of genes involved in immune response during LPS-induced inflammation. Selected gene expression changes were validated using quantitative RT-PCR. Fish oil reduced the expressions of pro-inflammatory genes IL1R1, IL1RAP, CEBPB and CRP, and increased that of anti-inflammatory genes IL-18BP, NFKBIA, IFIT1, IFIT2 and ATF3. Moreover, fish oil restored the expressions of some lipid metabolism-related genes, such as ACAA1, ACACA, ACADS and ACADM, which were only decreased in pigs fed a corn oil diet after LPS challenge. Our RNA sequencing reveals novel gene-nutrient interactions following fish oil supplementation and evoked inflammation, which add to the current understanding of the benefits of n-3 polyunsaturated fatty acids against liver injury.

Comparative Analysis of Mitochondrial Proteome Reveals the Mechanism of Enhanced Ram Sperm Motility Induced by Carbon Ion Radiation After In Vitro Liquid Storage

The aim of this study was to reveal the mechanism of enhanced ram sperm motility induced by heavy ion radiation (HIR) after in vitro liquid storage. Ram semen was stored for 24 hours at 5°C and then irradiated with 0.1 Gy carbon ion radiation (CIR). In comparison to nonirradiated (NIR) sperm, the motility, viability, and adenosine triphosphate content were all higher in CIR sperm, and the reactive oxygen species levels were lower. Moreover, 87 differential mitochondrial protein spots were detected in 2-dimensional gels between CIR and NIR sperm and were identified as 52 corresponding proteins. In addition, 33 differential proteins were involved in a main pathway network, including COX5B, ERAB/HSD17B10, ETFA, SDHB, and SOD2, which are known to be involved in cell communication, energy production, and antioxidant responses. We used immunoblotting and immunofluorescence to analyze the content and localization of these proteins, respectively, and the levels of these proteins in CIR sperm were lower than those in NIR sperm. An understanding of the molecular function of these proteins could provide further insight into the mechanisms underlying high sperm motility induced by HIR in rams.