The role of TRIM family in metabolic associated fatty liver disease

The Role of Tripartite Motif Family Proteins in Chronic Liver Diseases: Molecular Mechanisms and Therapeutic Potential

The worldwide impact of liver diseases is increasing steadily, with a consistent upswing evidenced in incidence and mortality rates. Chronic liver diseases (CLDs) refer to the liver function's progressive deterioration exceeding six months, which includes abnormal clotting factors, detoxification failure, and hepatic cholestasis. The most common etiologies of CLDs are mainly composed of chronic viral hepatitis, MAFLD/MASH, alcoholic liver disease, and genetic factors, which induce inflammation and harm to the liver, ultimately resulting in cirrhosis, the irreversible final stage of CLDs. The latest research has shown that tripartite motif family proteins (TRIMs) function as E3 ligases, which participate in the progression of CLDs by regulating gene and protein expression levels through post-translational modification. In this review, our objective is to clarify the molecular mechanisms and potential therapeutic targets of TRIMs in CLDs and provide insights for therapy guidelines and future research.

Tripartite motif 2b (trim2b) restricts spring viremia of carp virus by degrading viral proteins and negative regulators NLRP12-like receptors

Tripartite motif (TRIM) proteins are involved in different cellular functions, including regulating virus infection. In teleosts, two orthologous genes of mammalian TRIM2 are identified. However, the functions and molecular mechanisms of piscine TRIM2 remain unclear. Here, we show that trim2b-knockout zebrafish are more susceptible to spring viremia of carp virus (SVCV) infection than wild-type zebrafish. Transcriptomic analysis demonstrates that NOD-like receptor (NLR), but not RIG-I-like receptor (RLR), signaling pathway is significantly enriched in the trim2b-knockout zebrafish. In vitro, overexpression of Trim2b fails to degrade RLRs and those key proteins involved in the RLR signaling pathway but does for negative regulators NLRP12-like proteins. Zebrafish Trim2b degrades NLRP12-like proteins through its NHL_TRIM2_like and IG_FLMN domains in a ubiquitin-proteasome degradation pathway. SVCV-N and SVCV-G proteins are also degraded by NHL_TRIM2_like domains, and the degradation pathway is an autophagy lysosomal pathway. Moreover, zebrafish Trim2b can interfere with the binding between NLRP12-like protein and SVCV viral RNA and can completely block the negative regulation of NLRP12-like protein on SVCV infection. Taken together, our data demonstrate that the mechanism of action of zebrafish trim2b against SVCV infection is through targeting the degradation of host-negative regulators NLRP12-like receptors and viral SVCV-N/SVCV-G genes.IMPORTANCESpring viremia of carp virus (SVCV) is a lethal freshwater pathogen that causes high mortality in cyprinid fish. In the present study, we identified zebrafish trim2b, NLRP12-L1, and NLRP12-L2 as potential pattern recognition receptors (PRRs) for sensing and binding viral RNA. Zebrafish trim2b functions as a positive regulator; however, NLRP12-L1 and NLRP12-L2 function as negative regulators during SVCV infection. Furthermore, we find that zebrafish trim2b decreases host lethality in two manners. First, zebrafish Trim2b promotes protein degradations of negative regulators NLRP12-L1 and NLRP12-L2 by enhancing K48-linked ubiquitination and decreasing K63-linked ubiquitination. Second, zebrafish trim2b targets viral RNAs for degradation. Therefore, this study reveals a special antiviral mechanism in lower vertebrates.

TRIM14 suppressed the progression of NSCLC via hexosamine biosynthesis pathway

Tripartite Motif 14 (TRIM14) is an oncoprotein that belongs to the E3 ligase TRIM family, which is involved in the progression of various tumors except for non-small cell lung carcinoma (NSCLC). However, little is currently known regarding the function and related mechanisms of TRIM14 in NSCLC. Here, we found that the TRIM14 protein was downregulated in lung adenocarcinoma tissues compared with the adjacent tissues, which can suppress tumor cell proliferation and migration both in vitro and in vivo. Moreover, TRIM14 can directly bind to glutamine fructose-6-phosphate amidotransferase 1 (GFAT1), which in turn results in the degradation of GFAT1 and reduced O-glycosylation levels. GFAT1 is a key enzyme in the rate-limiting step of the hexosamine biosynthetic pathway (HBP). Replenishment of N-acetyl-d-glucosamine can successfully reverse the inhibitory effect of TRIM14 on the NSCLC cell growth and migration as expected. Collectively, our data revealed that TRIM14 suppressed NSCLC cell proliferation and migration through ubiquitination and degradation of GFAT1, providing a new regulatory role for TRIM14 on HBP.

Genomic and transcriptome insight into the structure and immunity role of TRIM proteins in Chinese soft-shelled turtles (Pelodiscus sinensis) after Aeromonas hydrophila infection

BACKGROUND

TRIM proteins, recognized as a class of E3 ubiquitin ligases, are increasingly acknowledged for their antipathogen immune functions in mammals and fish. In the Chinese soft-shelled turtle (Pelodiscus sinensis), a secondary aquatic reptile that occupies a unique evolutionary position, the TRIM gene has rarely been reported.

METHODS AND RESULTS

In the present study, 48 PsTRIM proteins were identified from the genome of Pelodiscus sinensis via Hidden Markov Model (HMM) searches and Signal Transduction ATPases with Numerous Domains (SMART) analysis. These PsTRIMs were found across 43 distinct scaffolds, and phylogenetic analyses classified them into three principal clades. The PsTRIMs feature a conserved assembly of either RING-B-box-coiled-coil (RBCC) or B-box-coiled-coil (BBC) domains at the N-terminus, in addition to eight unique domains at the C-terminus, including the B30.2 domain, 19 of which were identified. Expression profiling revealed ubiquitous expression of the 48 PsTRIMs across various P. sinensis tissues. Notably, seven PsTRIMs exhibited significant differential expression in liver transcriptomes following infection with Aeromonas hydrophila. Weighted gene coexpression network analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis implicated PsTRIM14 and PsTRIM28 as key players in host defense against bacterial invasion. Real-time quantitative PCR results indicated that PsTRIM1, PsTRIM2, PsTRIM14, and PsTRIM28 experienced marked upregulation in P. sinensis livers at 12 h post-infection with A. hydrophila.

CONCLUSIONS

Our study is the first to comprehensively identify and analyze the functions of TRIM genes in P. sinensis, unveiling their considerable diversity and potential roles in modulating immune responses.