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IntroductionApolipoprotein E (apoE) acts as a binding molecule for both the low-density lipoprotein receptor and the lipoprotein receptor-related protein and this function is essential for facilitating the hepatocyte uptake of lipoproteins containing apoB. The absence of apoE leads to increased atherogenicity in both humans and mice, although the precise molecular mechanisms remain incompletely understood.ObjectivesThis study aimed to investigate the susceptibility of apoE knockout (KO) rabbits, in comparison with wild-type (WT) rabbits, to diet-induced hyperlipidemia and atherosclerosis.MethodsApoE KO rabbits and WT rabbits were fed a diet containing 0.3% cholesterol for 16 weeks. Plasma lipid levels, lipoproteins, and apolipoproteins were analyzed. Atherosclerosis was evaluated at the endpoint of experiments. In addition, we evaluated the oxidizability of those lipoproteins containing apoB to investigate the possible mechanisms of atherosclerosis.ResultsMale apoE KO rabbits showed significantly elevated levels of total cholesterol and triglycerides compared to WT rabbits, while female apoE KO rabbits displayed similar high total cholesterol levels, albeit with significantly higher triglycerides levels than WT controls. Notably, both male (2.1-fold increase) and female (1.6-fold increase) apoE KO rabbits exhibited a significantly augmented aortic lesion area compared to WT controls. Pathological examination showed that the increased intimal lesions in apoE KO rabbits were featured by heightened infiltration of macrophages (2.7-fold increase) and smooth muscle cells (2.5-fold increase). Furthermore, coronary atherosclerotic lesions were also increased by 1.3-fold in apoE KO rabbits. Lipoprotein analysis revealed that apoB48-rich beta-very-low-density lipoproteins were notably abundant in apoE KO rabbits, suggesting that these remnant lipoproteins of intestinal origin serve as the primary atherogenic lipoproteins. Moreover, apoB48-rich remnant lipoproteins isolated from apoE KO rabbits exhibited heightened susceptibility to copper-induced oxidation.ConclusionsThe findings indicate that apoB48-rich remnant lipoproteins, resulting from apoE deficiency, possess greater atherogenic potential than apoB100-rich remnant lipoproteins, regardless of plasma TC levels.

Mild organic substitution is advantageous for sustainable agricultural development. In order to determine the proper fertilization strategy, it is essential to investigate the impact of substituting chemical fertilizers with varying levels of organic manure on soil nutrients, microbial communities, and crop productivity. Four treatments were implemented: no fertilizer, sole chemical fertilizer, 20% organic manure substitution, and 40% organic manure substitution. Bacterial and fungal communities were characterized through high-throughput sequencing of the 16S rRNA gene V3–V4 region and the V4 region, respectively. The 20% and 40% organic manure substitutions increased soil organic matter (SOM) content, total nitrogen (TN) content, and reduced soil pH compared to the control (CK). The 20% organic manure substitution showed the most significant improvements in soil alkaline phosphatase, urease, and invertase activities. Soil nutrient enhancement increased bacterial alpha diversity, with a milder impact on fungal alpha diversity compared to bacteria. Different fertilization treatments elevated the relative abundance of bacterial Bacteroidetes (8.11%, 21.25%, and 1.88%), Actinomycetes (12.65%, 26.36%, and 15.33%), and fungal Ascomycota (16.19%, 10.44%, and 12.69%), known for degrading recalcitrant organic matter. The sole chemical fertilizer treatment increased the pathogenic Cheatotryiales. Shared species, primarily from bacterial Actinomycetes, Firmicutes, Proteobacteria, and fungal Ascomycota phyla, were found at 20% and 40% organic manure substitution levels. Specifically, the 20% organic manure substitution level promoted the relative abundance of beneficial plant growth-promoting taxa, Oxalobacteraceae and Massilia, and suppressed pathogens, with an increase in the relative abundance of the Purpureocillium genus and Mortierellomycota. These findings suggest that a 20% OF substitution can maintain crop yield, enhance soil nutrients and enzyme activities by fostering beneficial soil bacteria, inhibiting soil-borne pathogens, and refining microbial community structure.