No abstract

ABCG5 (G5) and ABCG8 (G8) form a sterol transporter that acts in liver and intestine to prevent accumulation of dietary sterols. Mutations in either G5 or G8 cause sitosterolemia, a recessive disorder characterized by sterol accumulation and premature coronary atherosclerosis. Hepatic G5G8 mediates cholesterol excretion into bile, but the function and relative importance of intestinal G5G8 has not been defined. To determine the role of intestinal G5G8, we developed liver-specific (L-G5G8−/−), intestine-specific (I-G5G8−/−), and total (G5G8−/−) KO mice. Tissue levels of sitosterol, the most abundant plant sterol, were >90-fold higher in G5G8−/− mice than in WT animals. Expression of G5G8 only in intestine or only in liver decreased tissue sterol levels by 90% when compared with G5G8−/− animals. Biliary sterol secretion was reduced in L-G5G8−/− and G5G8−/− mice, but not in I-G5G8−/− mice. Conversely, absorption of plant sterols was increased in I-G5G8−/− and G5G8−/− mice, but not in L-G5G8−/− mice. Reverse cholesterol transport, as assessed from the fraction of intravenously administered 3H-cholesterol that appeared in feces, was reduced in G5G8−/−, I-G5G8−/−, and L-G5G8−/− mice. Thus, G5G8 expression in both the liver and intestine protects animals from sterol accumulation, and intestinal G5G8 contributes to extrahepatic cholesterol efflux in mice.

Trichinella spp., are amongst the most widespread parasitic nematodes, primarily live in the muscles of a wide range of vertebrate animals and humans. Human infection occurs by ingestion of raw or undercooked meat containing Trichinella larvae. Accurate diagnosis of Trichinella spp. infection in domestic animals is crucial for the effective prevention and control of human trichinellosis. In the present study, a simple, rapid and accurate diagnostic assay was developed combining recombinase polymerase amplification and a lateral flow strip (LF-RPA) to detect Trichinella spp. infection. The LF-RPA assay targets Trichinella spp. mitochondrial small-subunit ribosomal RNA (rrnS) gene and can detect as low as 100 fg DNA of Trichinella strains, which was approximately 10 times more sensitive than a conventional PCR assay. The LF-RPA assay can be performed within 10–25 min, at a wide range of temperatures (25–45°C) and showed no cross-reactivity with DNA of other parasites and related host species of Trichinella. The performance of the LF-RPA assay in the presence of high concentration of PCR inhibitor was better than that of a conventional PCR assay. Results obtained by LF-RPA assay for the detection of experimentally infected mice were comparable to the results obtained by using a conventional PCR, achieving 100% specificity and high sensitivity. These results present the developed LF-RPA assay as a new simple, specific, sensitive, rapid and convenient method for the detection of Trichinella infection in domestic animals.