xu, j. | bioRxiv Science

bioRxiv2022

IDOL deficiency inhibits cholesterol-rich diet-induced atherosclerosis in rabbits

BACKGROUNDThe E3 ubiquitin ligase IDOL (Inducible Degrader of the LDL-Receptor) contributes to regulation of cholesterol metabolism through degradation of LDLR, VLDLR and ApoER2. Human genetic studies support the hypothesis that IDOL could serve as a target for the treatment of dyslipidemia. However, species-specific differences in overall lipid metabolism and IDOL regulation require new preclinical models to realize its therapeutic potential. We leveraged the advantages afforded by the rabbit model to address those limitations and generated a novel rabbit IDOL knockout, which we characterized in the context of atherosclerosis. METHODSIDOL-/- rabbits were generated by CRISPR/Cas9 technology. IDOL-/- and wildtype littermates, on standard (SD) and atherogenic high-cholesterol diets (HCDs) were compared through assessment of lipid and lipoprotein profiles, triglyceride clearance, lipoprotein lipase (LPL) activity, liver pathology, atherosclerosis development, and fecal cholesterol, with bile acid contents assessed by mass spectrometry. ResultsHepatic IDOL expression was increased in response to hypercholesterolemia and hypertriglyceridemia induced by HCD. On SD, loss of IDOL increased LDLR stability with reduced total cholesterol in plasma. On HCD, IDOL-/- rabbits showed simultaneous and remarkable reduction in hypercholesterolemia and hypertriglyceridemia associated with enhanced lipid clearance and LPL activity as well as increased bile acid excretion in feces. IDOL-/- rabbits presented markedly reduced HCD-induced atherosclerosis in the aorta and left coronary artery, without enhanced liver steatosis. CONCLUSIONSLoss of IDOL in rabbits recapitulates human genetic findings, thus setting the stage to accelerate preclinical studies towards development of strategies targeting IDOL for the treatment of atherosclerotic cardiovascular disease.

physiology↗

bioRxiv2022

Outer Membrane Vesicle Mediated Multidrug Resistance Gene Transfer in Avibacterium Paragallinarum

Infectious coryza is an acute upper respiratory tract infectious disease caused by Avibacterium paragallinarum, which can cause growth retardation and egg production decline of bred chickens, and bring great economic losses to poultry industry. A. Paragallinarum is a Gram-negative bacterium and can release outer membrane vesicles (OMVs). In this study, a comparative genomic analysis of A. Paragallinarum isolate P4chr1 and its OMVs were carried out, and the ability to transfer antibiotic resistance genes via the OMVs was studied. The sequencing and data analysis showed that genome size of A. paragallinarum P4chr1 is about 2.77 Mb and it has a 25 kb tolerance island covering 6 types of antibiotics and 11 resistance genes. The genome size of its OMVs is about 2.69 Mb, covering 97% genome length and almost all gene sequences of P4chr1. When purified and DNase treated A. paragallinarum P4chr1 OMVs were co-cultured with antibiotic sensitive A. paragallinarum Modesto strain on an antibiotic containing plate, the colonies grown on the plate were detected corresponding antibiotic resistance gene (ARG). However, antimicrobial susceptibility test exposed that drug resistance genes delivered by OMVs were not persistent, they only existed temporarily on the antibiotic plates. The antibiotic resistance and ARGs disappeared at second bacterial passage. Overall, this study is the first report to compare genomic characteristics of OMVs with its parent A. paragallinarum strain, and to study A. paragallinarum ARG transfer via OMVs. This work has provided useful data for further study on the issue of non-plasmid ARG transfer mediated by A. paragallinarum OMVs.

molecular biology↗