Liver injury in COVID-19: Detection, pathogenesis, and treatment.

In the early December 2019, a novel coronavirus named severe acute respiratory syndrome coronavirus 2 was first reported in Wuhan, China, followed by an outbreak that spread around the world. Numerous studies have shown that liver injury is common in patients with coronavirus disease 2019 (COVID-19), and may aggravate the severity of the disease. However, the exact cause and specific mechanism of COVID-associated liver injury needs to be elucidated further. In this review, we present an analysis of the clinical features, potential mechanisms, and treatment strategies for liver injury associated with COVID-19. We hope that this review would benefit clinicians in devising better strategies for management of such patients.

[New insights in regulation factors of lipoprotein lipase].

Lipoprotein lipase (LPL) is an essential enzyme in the lipid metabolism, and proper regulation of LPL is important for controlling the delivery of lipid nutrients to tissues. Recent studies have identified glycosylphosphatidylinositol-anchored high density lipoprotein-binding protein 1(GPIHBP1) as the important regulation factor of LPL that serves as a binding platform for lipolysis on the vascular lumen and an endothelial cell transporter transporting LPL from the interstitial spaces to the capillary lumen. In addition, several other regulation factors of LPL have also been identified including microRNAs, SorLA (Sortilin-related receptor with A-type repeats), and apolipoproteins that are potentially important for regulating LPL activity. These discoveries provide new directions for understanding basic mechanisms of lipolysis and hyperlipidemia. In this update, we focused on summarizing recent progresses on GPIHBP1, the endothelial cell LPL transporter. We also highlighted the recent progresses on several other regulation factors of LPL that are relevant to the regulation of LPLactivity.

Sequence characterization, tissue-specific expression and polymorphism of the porcine (Sus scrofa) liver-type fatty acid binding protein gene.

In this study, the full-length cDNA of porcine liver-type fatty acid binding protein gene (L-FABP) was obtained by the rapid amplification of cDNA ends (RACE). The nucleotide sequence and the predicted protein sequence share a high sequence identity with their mammalian counterparts. Semi-quantitative RT-PCR revealed that porcine L-FABP gene is expressed in all twelve tissues studied, but a transcript is more abundant in liver and small intestine than in other tissues. The part genomic DNA of the porcine L-FABP gene was amplified by PCR. The coding region of the pig L-FABP gene is organized in four exons and spans an approximate 2.62 kb genomic region. Comparative sequencing of four pig breeds revealed a C-->T single nucleotide polymorphism (SNP) within exon 2. The allele and genotype frequencies differed significantly between indigenous Chinese Zang, Dahe, and Yanan pigs with higher frequencies of allele C and genotype CC and Yorkshire pigs with higher frequencies of allele T and genotype TT (P < 0.01). The association analysis suggested that the C-->T polymorphism was associated with intramuscular fat content, indicating that the SNP is a potential molecular marker for intramuscular fat content.

Molecular cloning and tissue-specific expression of intestinal-type fatty acid binding protein in porcine.

The intestinal fatty acid-binding protein (I-FABP) shows binding specificity for long-chain fatty acids and is proposed to be involved in the uptake of dietary fatty acids and their intracellular transport. In this study, the full-length cDNA of I-FABP was cloned from pig intestine by homology cloning approach combined with 3' and 5' RACE. Sequence analysis and bioinformatics study showed that this cDNA contained 614 nucleotides, with a 399 bp open reading frame (ORF) flanked by a 43 bp 5' UTR and a 172 bp 3' UTR. The encoded 132 amino acids of pig I-FABP with a molecular weight of approximately 15 kDa shared a high sequence identity of 68%-85% with those of other species. In addition, the phylogenetical analysis also indicated that the pig I-FABP was in the same branch with those of other species. The tissue-specific expression of pig I-FABP was measured by Northern hybridization and semi-quantitative RT-PCR. The results demonstrated that pig I-FABP mRNA was extensively present in various tissues, but I-FABP transcript of approximately 620 bp was more abundant in intestine than in other tissues.