Conserved structural and functional aspects of the tripartite motif gene family point towards therapeutic applications in multiple diseases

TRIM22 inhibits the metastasis of colorectal cancer through facilitating β-Catenin degradation

Tripartite motif-containing 22 (TRIM22), a member of the tripartite motif protein family, has emerged as a putative tumor suppressor in various cancers. Nevertheless, its specific role and clinical significance in colorectal cancer (CRC) remain poorly characterized. Herein, we observed that TRIM22 expression was frequently downregulated in primary CRC tissues and was significantly correlated with better prognosis. Functional assays demonstrated that TRIM22 overexpression substantially attenuated the metastatic potential of CRC cells both in vitro and in vivo. Mechanistically, our results revealed that TRIM22 directly interacts with and ubiquitinates β-Catenin, a crucial transcription factor that drives CRC metastasis by modulating the epithelial-mesenchymal transition (EMT) process. Additionally, our data indicated that the anti-metastatic effect of TRIM22 relies on the degradation of β-catenin. In summary, this study is the first to deliberate the vital anti-tumor role of TRIM22 in CRC metastasis. We also provide new evidence suggesting that TRIM22 could be a prognostic marker and therapeutic target for inhibiting CRC progression.

Role of TRIM29 in disease: What is and is not known

Tripartite motif-containing proteins (TRIMs), comprising the greatest subfamily of E3 ubiquitin ligases with approximately 80 members of this family, are widely distributed in mammalian cells. TRIMs actively participate in ubiquitination of target proteins, a type of post-translational modification associated with protein degradation and other functions. Tripartite motif-containing protein 29 (TRIM29), a member of the TRIM family, differs from other members of this family in that it lacks the RING finger structural domain containing cysteine and histidine residues that mediates DNA binding, protein-protein interactions, and ubiquitin ligase, at its N-terminus. The expression of TRIM29 was initially found to be associated with cancer and diabetic nephropathy progression, and antiviral immunity which is triggered by virus-derived nucleic acids binding to pattern recognition receptors (PRRs) on immune cells. Recently, TRIM29 has also been explored as a diagnostic biomarker and therapeutic target for some immune-related diseases. Here, we review the functions of TRIM29 in the progression of diseases and the inherent mechanisms, as well as the remaining gaps in the literature. A thorough understanding of the detailed regulatory mechanisms of TRIM29 will ultimately facilitate the development of different therapeutic strategies for various diseases.

Regulation of NLRP3/TRIM family signaling in gut inflammation and colorectal cancer

CRC (Colorectal cancer) ranks among the most prevalent tumors in humans and remains a leading cause of cancer-related mortality worldwide. Numerous studies have highlighted the connection between inflammasome over-activation and the initiation and progression of CRC. The activation of the NLRP3 (NOD-like receptor family, pyrin domain containing 3) inflammasome is dependent on the nuclear NF-kβ (Nuclear Factor kappa-light-chain-enhancer of activated B cells) pathway, leading to the maturation and release of inflammatory cytokines such as IL-1ß (Interleukin 1 beta) and IL-18 (Interleukin 18). While inflammation is crucial for defense mechanisms and tissue repair, excessive information can pose significant risks. Mounting evidence suggests that overactivation of the inflammasome contributes to the pathogenesis of inflammatory diseases. Consequently, there is a concerted effort to tightly regulate inflammasome activity and mitigate excessive inflammatory responses, particularly in conditions such as IBD (Inflammatory Bowel Disease), which includes Ulcerative Colitis and Crohn's Disease. The tripartite motif (TRIM) protein family, characterized by a conserved structure and rapid evolutionary diversification, includes members with critical roles in ubiquitination and other regulatory functions. Their importance in modulating inflammatory responses is widely acknowledged. This article aims to investigate the interplay between TRIM proteins and the NLRP3 Inflammasome in CRC and gut inflammation, offering insights for future research endeavors and potential therapeutic strategies.

Tripartite motif (TRIM) proteins roles in the regulation of immune system responses: Focus on autoimmune diseases

The tripartite motif (TRIM) proteins are well-studied as essential modulators of many processes, including the modulation of several pathways linked to immunological reactions. Most TRIM family members can polyubiquitinate the targeted proteins by acting as E3 ubiquitin ligases. According to current research, TRIMs play a critical role in innate immune response via modifying transcription factors, pattern recognition receptors (PRRs), and key adaptor proteins within innate immunity. It is becoming clearer that TRIMs play important roles in adaptive immune response, especially in the stimulation and promotion of T cells. We highlight the E3 ubiquitin ligase functions of TRIMs in the PRRs axis linked to autoimmune disorders. By focusing on TRIM family members, we also clarify the new approaches to regulating immunological reactions to alleviate autoimmunity.

Redirecting E3 ubiquitin ligases for targeted protein degradation with heterologous recognition domains

Targeted protein degradation (TPD) mediated by proteolysis targeting chimeras or molecular glues is an emerging therapeutic strategy. Despite greater than 600 E3 ligases and their associated components, a limited number have been deployed in TPD. Those commonly used include cereblon and von Hippel-Lindau tumor suppressor (VHL), which is expressed widely and for which high affinity ligands are available. Limiting TPD to specific cells or tissues would be desirable in many settings. To this goal we have determined the potential of two erythroid cell-enriched E3 ligases, TRIM10 and TRIM58, to degrade a protein of interest, BCL11A, a validated therapeutic target for the β-hemoglobinopathies. We established a general strategy in which heterologous recognition domains replace the PRY-SPRY domain of TRIM10 and TRIM58. Recruitment of TRIM10 or TRIM58 to BCL11A by coiled-coil peptides, nanobodies, or the substrate recognition domain of cereblon led to its degradation. Our findings illustrate a strategy that may be widely useful in evaluating the TPD potential of other E3 ubiquitin ligases and provide a rationale for discovery of ligands for TRIM10 and TRIM58 for erythroid-selective depletion of proteins of interest.

The Role and Mechanism of TRIM Proteins in Gastric Cancer

Tripartite motif (TRIM) family proteins, distinguished by their N-terminal region that includes a Really Interesting New Gene (RING) domain with E3 ligase activity, two B-box domains, and a coiled-coil region, have been recognized as significant contributors in carcinogenesis, primarily via the ubiquitin-proteasome system (UPS) for degrading proteins. Mechanistically, these proteins modulate a variety of signaling pathways, including Wnt/β-catenin, PI3K/AKT, and TGF-β/Smad, contributing to cellular regulation, and also impact cellular activities through non-signaling mechanisms, including modulation of gene transcription, protein degradation, and stability via protein-protein interactions. Currently, growing evidence indicates that TRIM proteins emerge as potential regulators in gastric cancer, exhibiting both tumor-suppressive and oncogenic roles. Given their critical involvement in cellular processes and the notable challenges of gastric cancer, exploring the specific contributions of TRIM proteins to this disease is necessary. Consequently, this review elucidates the roles and mechanisms of TRIM proteins in gastric cancer, emphasizing their potential as therapeutic targets and prognostic factors.

TRIM27 Promotes Endothelial Progenitor Cell Apoptosis in Patients with In-Stent Restenosis by Ubiquitinating TBK1

Approximately 2-10% in-stent restenosis (ISR) may occur following percutaneous coronary intervention (PCI) despite the use of modern drug-eluting stents (DES); thus, our study aimed to explore the effects of tripartite motif-containing (TRIM) 27 on ISR and the underlying mechanism. For this purpose, a total of 42 patients undergoing coronary angiography who had prior coronary angiography with DES implantation were recruited. Endothelial progenitor cells (EPCs) markers (defined as CD34 and vascular endothelial growth factoreceptor-2 (VEGFR-2)) in peripheral blood were measured to asses the circulating EPC level. The TRIM family-related gene expressions were detected by reverse transcription-quantitative polymerase chain reaction. Results suggested that ISR patients had reduced CD34+VEGFR-2+ and increased apoptosis rate of EPCs, along with upregulated TRIM27 and TRIM37 and downregulated TRIM28. TRIM27 promoted and TBK1 inhibited the apoptosis rate of EPCs. Mechanically, TRIM27 interacted with TBK1 to ubiquitinate TBK1 in in vitro study. In summary, TRIM27 promoted the progression of ISR in patients after PCI by ubiquitinating TBK1, which might provide novel ideas for the clinical treatment of ISR.

TRIM8 as a predictor for prognosis in childhood acute lymphoblastic leukemia based on a signature of neutrophil extracellular traps

Background

Neutrophil extracellular traps (NETs) can be attributed to the metastasis, occurrence, and immune evasion of cancer cells. We investigated the prognostic value of NET-related genes in childhood acute lymphoblastic leukemia (cALL) patients.

Methods

Differential gene expression analysis was conducted on samples collected from public databases. Grouping them based on the expression level of NET-related genes, we assessed the correlation between immune cell types and the risk score for having a poor prognosis of cALL, with an evaluation of the sensitivity of drugs used in cALL. We further divided the groups, integrating survival data. Subsequently, methods including multivariable Cox algorithms, least absolute shrinkage and selection operator (LASSO), and univariable were utilized to create a risk model predicting prognosis. Experiments in cell lines and animals were performed to explore the functions of TRIM8, a gene selected by the model. To validate the role of TRIM8 in leukemia development, lentivirus-mediated overexpression or knockdown of TRIM8 was employed in mice with T-ALL and B-ALL.

Results

Kaplan-Meier (KM) analysis underscored the importance of differentially expressed genes identified in the groups divided by genes participated in NETs, with enrichment analysis showing the mechanism. Correlation analysis revealed significant associations with B cells, NK cells, mast cells, T cells, plasma cells, dendritic cells, and monocytes. The IC50 values of drugs such as all-trans-retinoic acid (ATRA), axitinib, doxorubicin, methotrexate, sorafenib, and vinblastine were increased, while dasatinib exhibited a lower IC50. A total of 13 NET-related genes were selected in constructing the risk model. In the training, testing, and merged cohorts, KM analysis demonstrated significantly improved survival for low-risk cALL patients compared to high-risk cALL patients (p < 0.001). The area under the curve (AUC) indicated strong predictive performance. Experiments in Jurkat and SUP-B15 revealed that TRIM8 knockdown decreased the proliferation of leukemia cell lines. Further experiments demonstrated a more favorable prognosis in mice with TRIM8-knockdown leukemia cells. Results of cell lines and animals showed better outcomes in prognosis when TRIM8 was knocked down.

Conclusion

We identified a novelty in a prognostic model that could aid in the development of personalized treatments for cALL patients. Furthermore, it revealed that the expression of TRIM8 is a contributing factor to the proliferation of leukemia cells and worsens the prognosis of cALL.

Effects of Gene Alternative Splicing Events on Resistance to Cryptocaryonosis of Large Yellow Croaker (Larimichthys crocea)

Large yellow croaker (L. crocea) is a productive species in marine aquaculture with great economic value in China. However, the sustainable development of large yellow croaker is hampered by various diseases including cryptocaryonosis caused by Cryptocaryon irritans. The genetic regulation processes for cryptocaryonosis in large yellow croaker are still unclear. In this present study, we analyzed differential alternative splicing events between a C. irritans resistance strain (RS) and a commercial strain (CS). We identified 678 differential alternative splicing (DAS) events from 453 genes in RS and 719 DAS events from 500 genes in CS. A set of genes that are specifically alternatively spliced in RS was identified including mfap5, emp1, and trim33. Further pathway analysis revealed that the specifically alternative spliced genes in RS were involved in innate immune responses through the PRR pathway and the Toll and Imd pathway, suggesting their important roles in the genetic regulation processes for cryptocaryonosis in large yellow croaker. This study would be helpful for the studies of the pathogenesis of cryptocaryonosis and dissection of C. irritans resistance for L. crocea.

TRIM27 elicits protective immunity against tuberculosis by activating TFEB-mediated autophagy flux

Infectious diseases, such as Mycobacterium tuberculosis (Mtb)-caused tuberculosis (TB), remain a global threat exacerbated by increasing drug resistance. Host-directed therapy (HDT) is a promising strategy for infection treatment through targeting host immunity. However, the limited understanding of the function and regulatory mechanism of host factors involved in immune defense against infections has impeded HDT development. Here, we identify the ubiquitin ligase (E3) TRIM27 (tripartite motif-containing 27) as a host protective factor against Mtb by enhancing host macroautophagy/autophagy flux in an E3 ligase activity-independent manner. Mechanistically, upon Mtb infection, nuclear-localized TRIM27 increases and functions as a transcription activator of TFEB (transcription factor EB). Specifically, TRIM27 binds to the TFEB promoter and the TFEB transcription factor CREB1 (cAMP responsive element binding protein 1), thus enhancing CREB1-TFEB promoter binding affinity and promoting CREB1 transcription activity toward TFEB, eventually inducing autophagy-related gene expression as well as autophagy flux activation to clear the pathogen. Furthermore, TFEB activator 1 can rescue TRIM27 deficiency-caused decreased autophagy-related gene transcription and attenuated autophagy flux, and accordingly suppressed the intracellular survival of Mtb in cell and mouse models. Taken together, our data reveal that TRIM27 is a host defense factor against Mtb, and the TRIM27-CREB1-TFEB axis is a potential HDT-based TB target that can enhance host autophagy flux.Abbreviations: ATG5: autophagy related 5; BMDMs: bone marrow-derived macrophages; CFU: colony-forming unit; ChIP-seq: chromatin immunoprecipitation followed by sequencing; CREB1: cAMP responsive element binding protein 1; CTSB: cathepsin B; E3: ubiquitin ligase; EMSA: electrophoretic mobility shift assay; HC: healthy control; HDT: host-directed therapy; LAMP: lysosomal associated membrane protein; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MCOLN1: mucolipin TPR cation channel 1; Mtb: Mycobacterium tuberculosis; NLS: nuclear localization signal; PBMCs: peripheral blood mononuclear cells; PRKA/PKA: protein kinase cAMP-activated; qRT-PCR: quantitative real-time PCR; RFP: RET finger protein; TB: tuberculosis; TBK1: TANK binding kinase 1; TFEB: transcription factor EB; TRIM: tripartite motif; TSS: transcription start site; ULK1: unc-51 like autophagy activating kinase 1.

E3 Ubiquitin Ligases and Their Therapeutic Applications in Cancers: Narrative Review

E3 ubiquitin ligases are a class of enzymes, essential for maintaining the equilibrium of cells by binding ubiquitin molecules to substrates to mark them for destruction. Since many cancer-related proteins, including both oncogenic and tumor-suppressive ones, are controlled by the ubiquitin-proteasome system, E3 ligases have drawn a great deal of interest as potential targets for the creation of anti-cancer drugs. This is because E3 ligases function as modules that select the substrates that are intended for degradation, giving them the ability to particularly affect proteins that are connected to cancer. Their molecular properties and the ways in which they work serve as the basis for these distinctions. Investment in the creation of bioactive substances that can target E3 ligases is essential given the crucial roles they play in cancer. These substances have the potential to be powerful cancer-fighting tools. In this review, we explore the crucial roles that E3 ligases play in the biology of cancer. We also examine the current bioactive substances that have been created to target different E3 ligases, emphasizing their potential as candidates for treating the cancers.

TRIM8 promotes ovarian cancer proliferation and migration by targeting VDAC2 for ubiquitination and degradation

BACKGROUND

Ovarian cancer is a common gynecological tumor with high malignant potential and poor prognosis. TRIM8, is involved in the development of various tumors, but its precise regulatory role in ovarian cancer is still unknown.

AIMS

The aim of this study was to explore the specific mechanism by which TRIM8 regulates ovarian cancer.

MATERIALS AND METHODS

We used bioinformatics analysis to screen for high expression of TRIM8 in ovarian cancer. The expression of TRIM8 in healthy and cancerous ovarian tissues was assessed by immunofluorescence. TRIM8 was silenced or overexpressed in ovarian cancer cell lines, with cell proliferation and migration evaluated by CCK8, transwell and clonal formation assays. The effect of TRIM8 on ovarian cancer cells in vivo was assessed by subcutaneous tumor formation experiments in nude mice. The potential interacting protein VDAC2 was identified by mass spectrometry. The mechanism underlying TRIM8 regulation of VDAC2 was evaluated by co-immunoprecipitation and western blotting.

RESULTS

TRIM8 was overexpressed in ovarian cancer. TRIM8 promoted the proliferation and migration of ovarian cancer cells in vitro and the growth of subcutaneous tumors in mice in vivo. TRIM8 interacted with VDAC2, weakened the stability of the protein, and promoted its polyubiquitination and subsequent degradation. Knockdown of VDAC2 increased the resistance of ovarian cancer cells to iron death, whereas overexpression of VDAC2 attenuated ovarian cancer progression induced by TRIM8 overexpression.

DISCUSSION

TRIM8 promotes ovarian cancer proliferation and migration by targeting VDAC2 for ubiquitination and degradation, these finding may provide new targets for the treatment of ovarian cancer.

CONCLUSION

TRIM8 degraded VDAC2 through the ubiquitination pathway, increased the resistance of ovarian cancer cells to iron death, and promoted the proliferation and migration of ovarian cancer.

Ubiquitin ligase TRIM15 promotes the progression of pancreatic cancer via the upregulation of the IGF2BP2-TLR4 axis

BACKGROUND

The tripartite motif family, predominantly characterized by its E3 ubiquitin ligase activities, is involved in various cellular processes including signal transduction, apoptosis and autophagy, protein quality control, immune regulation, and carcinogenesis. Tripartite Motif Containing 15 (TRIM15) plays an important role in melanoma progression through extracellular signal-regulated kinase activation; however, data on its role in pancreatic tumors remain lacking. We previously demonstrated that TRIM15 targeted lipid synthesis and metabolism in pancreatic cancer; however, other specific regulatory mechanisms remain elusive.

METHODS

We used transcriptomics and proteomics, conducted a series of phenotypic experiments, and used a mouse orthotopic transplantation model to study the specific mechanism of TRIM15 in pancreatic cancer in vitro and in vivo.

RESULTS

TRIM15 overexpression promoted the progression of pancreatic cancer by upregulating the toll-like receptor 4. The TRIM15 binding protein, IGF2BP2, could combine with TLR4 to inhibit its mRNA degradation. Furthermore, the ubiquitin level of IGF2BP2 was positively correlated with TRIM15.

CONCLUSIONS

TRIM15 could ubiquitinate IGF2BP2 to enhance the function of phase separation and the maintenance of mRNA stability of TLR4. TRIM15 is a potential therapeutic target against pancreatic cancer.

Identification of novel NRF2-dependent genes as regulators of lead and arsenic toxicity in neural progenitor cells

Lead (Pb) and arsenic (As) are prevalent metal contaminants in the environment. Exposures to these metals are associated with impaired neuronal functions and adverse effects on neurodevelopment in children. However, the molecular mechanisms by which Pb and As impair neuronal functions remain poorly understood. Here, we identified F2RL2, TRIM16L, and PANX2 as novel targets of Nuclear factor erythroid 2-related factor 2 (NRF2)-the master transcriptional factor for the oxidative stress response-that are commonly upregulated with both Pb and As in human neural progenitor cells (NPCs). Using a ChIP (Chromatin immunoprecipitation)-qPCR assay, we showed that NRF2 directly binds to the promoter region of F2RL2, TRIM16L, and PANX2 to regulate expression of these genes. We demonstrated that F2RL2, PANX2, and TRIM16L have differential effects on cell death, proliferation, and differentiation of NPCs in both the presence and absence of metal exposures, highlighting their roles in regulating NPC function. Furthermore, the analyses of the transcriptomic data on NPCs derived from autism spectrum disorder (ASD) patients revealed that dysregulation of F2RL2, TRIM16L, and PANX2 was associated with ASD genetic backgrounds and ASD risk genes. Our findings revealed that Pb and As induce a shared NRF2-dependent transcriptional response in NPCs and identified novel genes regulating NPC function. While further in vivo studies are warranted, this study provides a novel mechanism linking metal exposures to NPC function and identifies potential genes of interest in the context of neurodevelopment.

TRIM62 knockdown by inhibiting the TLR4/NF-κB pathway and NLRP3 inflammasome attenuates cognitive impairment induced by diabetes in mice

The tripartite motif 62 is an E3 ubiquitin ligase protein that regulates cellular processes, including differentiation, immunity, development and apoptosis, leading to various disease states, such as cancer and inflammatory diseases. However, the role and mechanism of the tripartite motif 62 in the process of diabetic-induced cognitive impairment have not been reported. Therefore, the aim of this study was to investigate the role and mechanism of the tripartite motif 62 in diabetic-induced cognitive impairment. The results showed that the expression of the tripartite motif 62 was up-regulated in diabetic mice. Silencing of TRIM62 increased body weight and decreased fasting blood glucose in diabetic mice. In addition, knockdown of the tripartite motif 62 inhibited STZ-induced inflammation, apoptosis and oxidative stress. Further studies showed that the TLR4/NF-κB pathway and NLRP3 inflammasomes were involved in the regulation of diabetic mice by the tripartite motif 62. More importantly, inhibition of the tripartite motif 62 improved cognitive impairment and learning ability in mice. In conclusion, inhibition of TRIM62 inhibits STZ-induced inflammation, cell apoptosis and oxidative stress, and improves the cognitive ability of mice. Therefore, the tripartite motif 62 may be an important target for the treatment of diabetes-induced cognitive impairment.

The role of TRIM25 in the occurrence and development of cancers and inflammatory diseases

The tripartite motif (TRIM) family proteins are a group of proteins involved in different signaling pathways. The changes in the expression regulation, function, and signaling of this protein family are associated with the occurrence and progression of a wide range of disorders. Given the importance of these proteins in pathogenesis, they can be considered as potential therapeutic targets for many diseases. TRIM25, as an E3-ubiquitin ligase, is involved in the development of various diseases and cellular mechanisms, including antiviral innate immunity and cell proliferation. The clinical studies conducted on restricting the function of this protein have reached promising results that can be further evaluated in the future. Here, we review the regulation of TRIM25 and its function in different diseases and signaling pathways, especially the retinoic acid-inducible gene-I (RIG-I) signaling which prompts many kinds of cancers and inflammatory disorders.

Tripartite Motif Protein Family in Central Nervous System Diseases

Tripartite motif (TRIM) protein superfamily is a group of E3 ubiquitin ligases characterized by the conserved RING domain, the B-box domain, and the coiled-coil domain (RBCC). It is widely involved in various physiological and pathological processes, such as intracellular signal transduction, cell cycle regulation, oncogenesis, and innate immune response. Central nervous system (CNS) diseases are composed of encephalopathy and spinal cord diseases, which have a high disability and mortality rate. Patients are often unable to take care of themselves and their life quality can be seriously declined. Initially, the function research of TRIM proteins mainly focused on cancer. However, in recent years, accumulating attention is paid to the roles they play in CNS diseases. In this review, we integrate the reported roles of TRIM proteins in the pathological process of CNS diseases and related signaling pathways, hoping to provide theoretical bases for further research in treating CNS diseases targeting TRIM proteins. TRIM proteins participated in CNS diseases. TRIM protein family is characterized by a highly conserved RBCC domain, referring to the RING domain, the B-box domain, and the coiled-coil domain. Recent research has discovered the relations between TRIM proteins and various CNS diseases, especially Alzheimer's disease, Parkinson's disease, and ischemic stroke.

Genomic Analysis, Evolution and Characterization of E3 Ubiquitin Protein Ligase (TRIM) Gene Family in Common Carp (Cyprinus carpio)

Tripartite motifs (TRIM) is a large family of E3 ubiquitin ligases that play an important role in ubiquitylation. TRIM proteins regulate a wide range of biological processes from cellular response to viral infection and are implicated in various pathologies, from Mendelian disease to cancer. Although the TRIM family has been identified and characterized in tetrapods, but the knowledge about common carp and other teleost species is limited. The genes and proteins in the TRIM family of common carp were analyzed for evolutionary relationships, characterization, and functional annotation. Phylogenetic analysis was used to elucidate the evolutionary relationship of TRIM protein among teleost and higher vertebrate species. The results show that the TRIM orthologs of highly distant vertebrates have conserved sequences and domain architectures. The pairwise distance was calculated among teleost species of TRIMs, and the result exhibits very few mismatches at aligned position thus, indicating that the members are not distant from each other. Furthermore, TRIM family of common carp clustered into six groups on the basis of phylogenetic analysis. Additionally, the analysis revealed conserved motifs and functional domains in the subfamily members. The difference in functional domains and motifs is attributed to the evolution of these groups from different ancestors, thus validating the accuracy of clusters in the phylogenetic tree. However, the intron-exon organization is not precisely similar, which suggests duplication of genes and complex alternative splicing. The percentage of secondary structural elements is comparable for members of the same group, but the tertiary conformation is varied and dominated by coiled-coil segments required for catalytic activity. Gene ontology analysis revealed that these proteins are mainly associated with the catalytic activity of ubiquitination, immune system, zinc ion binding, positive regulation of transcription, ligase activity, and cell cycle regulation. Moreover, the biological pathway analyses identified four KEGG and 22 Reactome pathways. The predicted pathways correspond to functional domains, and gene ontology which proposes that proteins with similar structures might perform the same functions.

Trigred motif 36 regulates neuroendocrine differentiation of prostate cancer via HK2 ubiquitination and GPx4 deficiency

Neuroendocrine prostate cancer (NEPC), the most lethal subtype of castration-resistant prostate cancer (PCa), may evolve from the neuroendocrine differentiation (NED) of PCa cells. However, the molecular mechanism that triggers NED is unknown. Trigred motif 36 (TRIM36), a member of the TRIM protein family, exhibits oncogenic or anti-oncogenic roles in various cancers. We have previously reported that TRIM36 is highly expressed to inhibit the invasion and proliferation of PCa. In the present study, we first found that TRIM36 was lowly expressed in NEPC and its overexpression suppressed the NED of PCa. Next, based on proteomic analysis, we found that TRIM36 inhibited the glycolysis pathway through suppressing hexokinase 2 (HK2), a crucial glycolytic enzyme catalyzing the conversion of glucose to glucose-6-phosphate. TRIM36 specifically bound to HK2 through lysine 48 (lys48)-mediated ubiquitination of HK2. Moreover, TRIM36-mediated ubiquitination degradation of HK2 downregulated the level of glutathione peroxidase 4 (GPx4), a process that contributed to ferroptosis. In conclusion, TRIM36 can inhibit glycolysis via lys48-mediated HK2 ubiquitination to reduce GPX4 expression and activate ferroptosis, thereby inhibiting the NED in PCa. Targeting TRIM36 might be a promising approach to retard NED and treat NEPC.

TRIM27 maintains gut homeostasis by promoting intestinal stem cell self-renewal

Dysregulation of gut homeostasis is associated with irritable bowel syndrome (IBS), a chronic functional gastrointestinal disorder affecting approximately 11.2% of the global population. The poorly understood pathogenesis of IBS has impeded its treatment. Here, we report that the E3 ubiquitin ligase tripartite motif-containing 27 (TRIM27) is weakly expressed in IBS but highly expressed in inflammatory bowel disease (IBD), a frequent chronic organic gastrointestinal disorder. Accordingly, knockout of Trim27 in mice causes spontaneously occurring IBS-like symptoms, including increased visceral hyperalgesia and abnormal stool features, as observed in IBS patients. Mechanistically, TRIM27 stabilizes β-catenin and thus activates Wnt/β-catenin signaling to promote intestinal stem cell (ISC) self-renewal. Consistent with these findings, Trim27 deficiency disrupts organoid formation, which is rescued by reintroducing TRIM27 or β-catenin. Furthermore, Wnt/β-catenin signaling activator treatment ameliorates IBS symptoms by promoting ISC self-renewal. Taken together, these data indicate that TRIM27 is critical for maintaining gut homeostasis, suggesting that targeting the TRIM27/Wnt/β-catenin axis could be a potential treatment strategy for IBS. Our study also indicates that TRIM27 might serve as a potential biomarker for differentiating IBS from IBD.

Understanding Crassostrea virginica tolerance of Perkinsus marinus through global gene expression analysis

Disease tolerance, a host's ability to limit damage from a given parasite burden, is quantified by the relationship between pathogen load and host survival or reproduction. Dermo disease, caused by the protozoan parasite P. marinus, negatively impacts survival in both wild and cultured eastern oyster (C. virginica) populations. Resistance to P. marinus has been the focus of previous studies, but tolerance also has important consequences for disease management in cultured and wild populations. In this study we measured dermo tolerance and evaluated global expression patterns of two sensitive and two tolerant eastern oyster families experimentally challenged with distinct doses of P. marinus (0, 106, 107, and 108 parasite spores per gram wet weight, n = 3-5 individuals per family per dose). Weighted Gene Correlation Network Analysis (WGCNA) identified several modules correlated with increasing parasite dose/infection intensity, as well as phenotype. Modules positively correlated with dose included transcripts and enriched GO terms related to hemocyte activation and cell cycle activity. Additionally, these modules included G-protein coupled receptor, toll-like receptor, and tumor necrosis factor pathways, which are important for immune effector molecule and apoptosis activation. Increased metabolic activity was also positively correlated with treatment. The module negatively correlated with infection intensity was enriched with GO terms associated with normal cellular activity and growth, indicating a trade-off with increased immune response. The module positively correlated with the tolerant phenotype was enriched for transcripts associated with "programmed cell death" and contained a large number of tripartite motif-containing proteins. Differential expression analysis was also performed on the 108 dosed group using the most sensitive family as the comparison reference. Results were consistent with the network analysis, but signals for "programmed cell death" and serine protease inhibitors were stronger in one tolerant family than the other, suggesting that there are multiple avenues for disease tolerance. These results provide new insight for defining dermo response traits and have important implications for applying selective breeding for disease management.

TRIM36 inhibits tumorigenesis through the Wnt/β-catenin pathway and promotes caspase-dependent apoptosis in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and has an extremely poor prognosis. We aimed to determine the latent relationships between TRIM36 regulation of apoptosis and the Wnt/β-catenin pathway in HCC.

METHODS

Immunohistochemistry and western blotting were used to characterize the aberrant expression of TRIM36 in HCC and adjacent tissues. Clinical information was analyzed using Kaplan-Meier and Cox methods. RNA-seq of potential targets was conducted to detect the regulation of TRIM36. Apoptosis assays and cellular proliferation, invasion and migration were conducted in a loss- and gain-of-function manner in cultured cells to determine the biological functions of TRIM36. A rescue experiment was conducted to confirm the role of Wnt/β-catenin signaling in TRIM36 regulation. Finally, in vivo experiments were conducted using cell line-derived xenografts in nude mice to validate the central role of TRIM36 in HCC.

RESULTS

TRIM36 expression was significantly downregulated in HCC tissues compared to adjacent non-tumor tissues. TRIM36 repressed the proliferation, migration, and invasion of Huh7 and HCCLM3 cells, whereas it stimulated apoptosis. Wnt/β-catenin signaling was inhibited by TRIM36, and rescue experiments highlighted its importance in HCC proliferation, migration, and invasion. In vivo experiments further confirmed the effects of sh-TRIM36 on HCC tumorigenesis, inhibition of apoptosis, and promotion of Wnt/β-catenin signaling.

CONCLUSION

Our study is the first to indicate that TRIM36 acts as a tumor suppressor in HCC. TRIM36 activates apoptosis and inhibits cellular proliferation, invasion, and migration via the Wnt/β-catenin pathway, which may serve as an important biomarker and promising therapeutic target for HCC.

TRIM67 Deficiency Exacerbates Hypothalamic Inflammation and Fat Accumulation in Obese Mice

Obesity has achieved the appearance of a global epidemic and is a serious cause for concern. The hypothalamus, as the central regulator of energy homeostasis, plays a critical role in regulating food intake and energy expenditure. In this study, we show that TRIM67 in the hypothalamus was responsive to body-energy homeostasis whilst a deficiency of TRIM67 exacerbated metabolic disorders in high-fat-diet-induced obese mice. We found exacerbated neuroinflammation and apoptosis in the hypothalamus of obese TRIM67 KO mice. We also found reduced BDNF in the hypothalamus, which affected the fat sympathetic nervous system innervation and contributed to lipid accumulation in adipose tissue under high-fat-diet exposure. In this study, we reveal potential implications between TRIM67 and the hypothalamic function responding to energy overuptake as well as a consideration for the therapeutic diagnosis of obesity.

TRIM family proteins: roles in proteostasis and neurodegenerative diseases

Neurodegenerative diseases (NDs) are a diverse group of disorders characterized by the progressive degeneration of the structure and function of the central or peripheral nervous systems. One of the major features of NDs, such as Alzheimer's disease (AD), Parkinson's disease (PD) and Huntington's disease (HD), is the aggregation of specific misfolded proteins, which induces cellular dysfunction, neuronal death, loss of synaptic connections and eventually brain damage. By far, a great amount of evidence has suggested that TRIM family proteins play crucial roles in the turnover of normal regulatory and misfolded proteins. To maintain cellular protein quality control, cells rely on two major classes of proteostasis: molecular chaperones and the degradative systems, the latter includes the ubiquitin-proteasome system (UPS) and autophagy; and their dysfunction has been established to result in various physiological disorders including NDs. Emerging evidence has shown that TRIM proteins are key players in facilitating the clearance of misfolded protein aggregates associated with neurodegenerative disorders. Understanding the different pathways these TRIM proteins employ during episodes of neurodegenerative disorder represents a promising therapeutic target. In this review, we elucidated and summarized the diverse roles with underlying mechanisms of members of the TRIM family proteins in NDs.

Loss of TRIM67 Attenuates the Progress of Obesity-Induced Non-Alcoholic Fatty Liver Disease

Obesity is considered as a major cause for the development and progress of non-alcoholic fatty liver disease (NAFLD), which is one of the most prevalent chronic liver diseases worldwide. However, molecular mechanisms that implicate in obesity-driven pathophysiology of NAFLD are not well defined. Here, we report a tripartite motif (TRIM) protein family member—TRIM67—that is hardly expressed in liver but is inducible on obese conditions. Enhanced expression of TRIM67 activates hepatic inflammation to disturb lipid metabolic homeostasis and promote the progress of NAFLD induced by obesity, while the deficiency in TRIM67 is protective against these pathophysiological processes. Finally, we show that the important transcription coactivator PGC-1α implicates in the response of hepatic TRIM67 to obesity.

E3 ligase TRIM15 facilitates non-small cell lung cancer progression through mediating Keap1-Nrf2 signaling pathway

BACKGROUND

Recent studies have indicated that some members of the tripartite motif (TRIM) proteins function as important regulators for non-small cell lung cancer (NSCLC), However, the regulatory mechanism underpinning aberrant expression of TRIM in NSCLC remains unclear. Here we report that TRIM15 plays important roles in NSCLC progression through modulating Keap1-Nrf2 signaling pathway.

METHODS

TRIM15 expression was evaluated by western blot analysis, tissue microarray-based immunohistochemistry analysis. The interactions between TRIM15 and Keap1 were analyzed by co-immunoprecipitation (Co-IP) and immunofluorescence co-localization assay. The correlation between TRIM15 and Keap1 was measured by Co-IP and ubiquitination analysis in vitro. Gain- and lost-of-function experiments were used to detect TRIM15 promotes proliferation and invasion of NSCLC cells both in vitro and vivo.

RESULTS

Here, we revealed that TRIM15 was frequently upregulated in NSCLC samples and associated with poor prognosis. Functionally, TRIM15 knockdown resulted in decreased cancer cell proliferation and metastasis, whereas ectopic TRIM15 expression facilitated tumor cancer cell proliferation and metastasis in vitro and in vivo. Moreover, TRIM15 promoted cell proliferation and metastasis depends on its E3 ubiquitin ligase. Mechanistically, TRIM15 directly targeted Keap1 by ubiquitination and degradation, the principal regulator of Nrf2 degradation, leading to Nrf2 escaping from Keap1-mediated degradation, subsequently promoting antioxidant response and tumor progression.

CONCLUSIONS

Therefore, our study characterizes the pivotal roles of TRIM15 promotes NSCLC progression via Nrf2 stability mediated by promoting Keap1 ubiquitination and degradation and could be a valuable prognostic biomarker and a potential therapeutic target in NSCLC. Video Abstract.

Dissecting the Functional Role of the TRIM8 Protein on Cancer Pathogenesis

Simple Summary

The tripartite motif (TRIM) gene family is a large group of E3 ubiquitin ligase proteins that can also have proteasome-independent functions. This review summarizes the structural organization, the biological functions and the mechanisms involved in cancer pathogenesis of TRIM proteins. Furthermore, this paper focuses on TRIM8, a member of the TRIM family proteins, describing its role both as a tumor suppressor and as an oncogene.

Abstract

TRIM/RBCC are a large family of proteins that include more than 80 proteins, most of which act as E3 ligases and catalyze the direct transfer of Ubiquitin, SUMO and ISG15 on specific protein substrates. They are involved in oncogenesis processes and in cellular immunity. On this topic, we focus on TRIM8 and its multiple roles in tumor pathologies. TRIM8 inhibits breast cancer proliferation through the regulation of estrogen signaling. TRIM8 downregulation in glioma is involved in cell proliferation, and it is related to patients’ survival. Several studies suggested that TRIM8 regulates the p53 suppressor signaling pathway: it is involved in the NF-kB pathway (Nuclear Factor kappa light- chain-enhancer of activated B cells) and in STAT3 (Signal Transducer and Activator of Transcription 3) of the JAK-STAT pathway. In this review, we summarize how the association between these different pathways reflects a dual role of TRIM8 in cancer as an oncogene or a tumor suppressor gene.

Tripartite motif family proteins in inflammatory bowel disease: Mechanisms and potential for interventions

Inflammatory bowel disease (IBD) is a chronic recurrent gastrointestinal inflammatory disease that poses a heavy burden to the global healthcare system. However, the current paucity of mechanistic understanding of IBD pathogenesis hampers the development of aetiology‐directed therapies. Novel therapeutic options based on IBD pathogenesis are urgently needed for attaining better long‐term prognosis for IBD patients. The tripartite motif (TRIM) family is a large protein family including more than 70 structurally conservative members, typically characterized by their RBCC structure, which primarily function as E3 ubiquitin ligases in post‐translational modification. They have emerged as regulators of a broad range of cellular mechanisms, including proliferation, differentiation, transcription and immune regulation. TRIM family proteins are involved in multiple diseases, such as viral infection, cancer and autoimmune disorders, including inflammatory bowel disease. This review provides a comprehensive perspective on TRIM proteins' involvement in the pathophysiology and progression of IBD, in particular, on intestinal mucosal barriers, gene susceptibility and opportunistic infections, thus providing novel therapeutic targets for this complicated disease. However, the exact mechanisms of TRIM proteins in IBD pathogenesis and IBD‐related carcinogenesis are still unknown, and more studies are warranted to explore potential therapeutic targets of TRIM proteins in IBD.

Identification of a tripartite motif family gene signature for predicting the prognosis of patients with glioma

Objectiove: The tripartite motif (TRIM) family genes, which encode a protein subfamily of the RING type E3 ubiquitin ligases, function as important regulators of oncogenesis and development. It is thus of great importance to investigate the potential value of the TRIM family genes for prognostic prediction in glioma.

METHODS

The gene expression RNA-Seq data and corresponding clinical information of glioma patients were obtained from The Cancer Genome Atlas (TCGA) dataset and the Chinese Glioma Genome Atlas (CGGA) dataset. LASSO regression and multivariate Cox regression analyses were performed to construct a risk signature of the TRIM family genes. The accuracy of the risk signature in predicting the prognosis of glioma patients was evaluated. The effects of TRIM17 on glioma cell proliferation were further explored.

RESULTS

We constructed a prognostic signature based on eight TRIMs for the prediction of overall survival of glioma patients. Internal and external cohorts confirmed the satisfactory accuracy and generalizability of the signature in predicting the prognosis of glioma patients. Of the eight TRIMs, TRIM17 was significantly downregulated in glioma, and decreased with an increase in the tumor grade. Moreover, low expression of TRIM17 predicted poor prognosis in glioma. CCK-8 and colony formation assays indicated that TRIM17 overexpression significantly inhibited cell proliferation. Conversely, silencing of TRIM17 had the opposite effects.

CONCLUSION

Our eight-gene signature based on the TRIM gene family is a novel and clinically useful biomarker, which may be helpful for clinical decision-making. Additionally, TRIM17 might be a therapeutic target for glioma.

TRIMs: Generalists Regulating the NLRP3 Inflammasome Signaling Pathway

Inflammation is a double-edged sword. The moderate inflammatory response is a fundamental defense mechanism produced by the body's resistance to dangerous stimuli and a repair process of the body itself. Increasing studies have confirmed that the overactivation of the inflammasome is involved in the occurrence and development of inflammatory diseases. Strictly controlling the overactivation of the inflammasome and preventing excessive inflammatory response have always been the research focus on inflammatory diseases. However, the endogenous regulatory mechanism of inflammasome is not completely clear. The tripartite motif (TRIM) protein is one of the members of E3 ligases in the process of ubiquitination. The universality and importance of the functions of TRIM members are recognized, including the regulation of inflammatory response. This article will focus on research on the relationship between TRIMs and NLRP3 Inflammasome, which may help us make some references for future related research and the discovery of treatment methods.

Running 'LAPS' Around nLD: Nuclear Lipid Droplet Form and Function

The nucleus harbours numerous protein subdomains and condensates that regulate chromatin organization, gene expression and genomic stress. A novel nuclear subdomain that is formed following exposure of cells to excess fatty acids is the nuclear lipid droplet (nLD), which is composed of a neutral lipid core surrounded by a phospholipid monolayer and associated regulatory and lipid biosynthetic enzymes. While structurally resembling cytoplasmic LDs, nLDs are formed by distinct but poorly understood mechanisms that involve the emergence of lipid droplets from the lumen of the nucleoplasmic reticulum and de novo lipid synthesis. Luminal lipid droplets that emerge into the nucleoplasm do so at regions of the inner nuclear membrane that become enriched in promyelocytic leukemia (PML) protein. The resulting nLDs that retain PML on their surface are termed lipid-associated PML structures (LAPS), and are distinct from canonical PML nuclear bodies (NB) as they lack key proteins and modifications associated with these NBs. PML is a key regulator of nuclear signaling events and PML NBs are sites of gene regulation and post-translational modification of transcription factors. Therefore, the subfraction of nLDs that form LAPS could regulate lipid stress responses through their recruitment and retention of the PML protein. Both nLDs and LAPS have lipid biosynthetic enzymes on their surface suggesting they are active sites for nuclear phospholipid and triacylglycerol synthesis as well as global lipid regulation. In this review we have summarized the current understanding of nLD and LAPS biogenesis in different cell types, their structure and composition relative to other PML-associated cellular structures, and their role in coordinating a nuclear response to cellular overload of fatty acids.

TRIM26-mediated degradation of nucleocapsid protein limits porcine reproductive and respiratory syndrome virus-2 infection

Porcine reproductive and respiratory syndrome (PRRS), caused by PRRSV, has ranked among the most economically important veterinary infectious diseases globally. Recently, tripartite motif (TRIMs) family members have arisen as novel restriction factors in antiviral immunity. Noteworthy, TRIM26 was reported as a binding partner of IRF3, TBK1, TAB1, and NEMO, yet its role in virus infection remains controversial. Herein, we showed that TRIM26 bound N protein by the C-terminal PRY/SPRY domain. Moreover, ectopic expression of TRIM26 impaired PRRSV replication and induced degradation of N protein. The anti-PRRSV activity was independent of the nuclear localization signal (NLS). Instead, deletion of the RING domain, or the PRY/SPRY portion, abrogated the antiviral function. Finally, siRNA depletion of TRIM26 resulted in enhanced production of viral RNA and virus yield in porcine alveolar macrophages (PAMs) after PRRSV infection. Overexpression of an RNAi-resistant TRIM26 rescue-plasmid led to the acquisition of PRRSV restriction in TRIM26-knockdown cells. Together, these data add TRIM26 as a potential target for drug design against PRRSV.

TRIM40 inhibits IgA1-induced proliferation of glomerular mesangial cells by inactivating NLRP3 inflammasome through ubiquitination

IgA nephropathy, as the most common type of glomerulonephritis, causes chronic renal disease and progresses into kidney failure. Aberrant IgA deposition in the glomerular mesangium induces NLRP3 inflammasome activation for massive local inflammation, and is recognized as the primary pathogenesis in IgA nephropathy. Tripartite motif (TRIM)-containing proteins are E3 ubiquitin ligases that possess crucial regulatory functions in innate immunity, but their functional roles in IgA nephropathy are still unclear. Here, we aimed to identify TRIM-containing proteins that regulate IgA nephropathy and their underlying mechanisms. An in vitro IgA1-induction model was established in glomerular mesangial cells (GMCs) and showed that IgA1 could promote GMC proliferation by activating NLRP3 inflammasome. TRIM40, which was downregulated by IgA1 and interacted with NLRP3, was recognized as a promising candidate. In addition, TRIM40 could suppress IgA1-induced GMC proliferation by inhibiting the activation of NLRP3 inflammasome. Based on coimmunoprecipitation and ubiquitination assays, we confirmed that TRIM40 could mediate the ubiquitination of NLRP3, which explained its regulatory effects on NLRP3 inflammasome and GMC proliferation. More importantly, a dominant-negative mutant of TRIM40 lacking the RING domain (ΔRING) did not affect NLRP3 ubiquitination, and had no effects on IgA1-induced GMC proliferation or NLRP3 inflammasome activation. This study revealed the biological functions of TRIM40 in IgA nephropathy, facilitating its application as therapeutic target for IgA nephropathy and other NLRP3 inflammasome-relevant diseases.

TRIM proteins in fibrosis

Fibrosis is an outcome of tissue repair after different types of injuries. The homeostasis of extracellular matrix is broken, and excessive deposition occurs, affecting the normal function of tissues and organs, which could become prostrated in serious cases.Finding a suitable target to regulate the repair process and reduce the damage caused by fibrosis is a hot research topic at present. The TRIM family is number of one of the E3 ubiquitin ligase subfamilies and participates in various biological processes including intracellular signal transduction, apoptosis, autophagy, and immunity by regulating the ubiquitination of target proteins. For the past few years, the important role of TRIM in the occurrence and development of fibrosis has been gradually revealed. In this review, we focus on the recent emerging topics on TRIM proteins in the regulation of fibrosis, fibrosis-related cytokines and pathways.

Muscle multiorgan crosstalk with MG53 as a myokine for tissue repair and regeneration

Through stress and injury to tissues, the cell membrane is damaged and can lead to cell death and a cascade of inflammatory events. Soluble factors that mitigate and repair membrane injury are important to normal homeostasis and are a potential therapeutic intervention for regenerative medicine. A myokine is a type of naturally occurring factors that come from muscle and have impact on remote organs. MG53, a tripartite motif-containing family protein, is such a myokine which has protective effects on lungs, kidneys, liver, heart, eye, and brain. Three mechanisms of action for the beneficial regenerative medicine potential of MG53 have been identified and consist of 1) repair of acute injury to the cellular membrane, 2) anti-inflammatory effects associated with chronic injuries, and 3) rejuvenation of stem cells for tissue regeneration. As such, MG53 has the potential to be a novel and effective regeneration medicine therapeutic.

The SUMOylation of TAB2 mediated by TRIM60 inhibits MAPK/NF-κB activation and the innate immune response

Activation of the TAK1 signalosome is crucial for mediating the innate immune response to pathogen invasion and is regulated by multiple layers of posttranslational modifications, including ubiquitination, SUMOylation, and phosphorylation; however, the underlying molecular mechanism is not fully understood. In this study, TRIM60 negatively regulated the formation and activation of the TAK1 signalosome. Deficiency of TRIM60 in macrophages led to enhanced MAPK and NF-κB activation, accompanied by elevated levels of proinflammatory cytokines but not IFN-I. Immunoprecipitation-mass spectrometry assays identified TAB2 as the target of TRIM60 for SUMOylation rather than ubiquitination, resulting in impaired formation of the TRAF6/TAB2/TAK1 complex and downstream MAPK and NF-κB pathways. The SUMOylation sites of TAB2 mediated by TRIM60 were identified as K329 and K562; substitution of these lysines with arginines abolished the SUMOylation of TAB2. In vivo experiments showed that TRIM60-deficient mice showed an elevated immune response to LPS-induced septic shock and L. monocytogenes infection. Our data reveal that SUMOylation of TAB2 mediated by TRIM60 is a novel mechanism for regulating the innate immune response, potentially paving the way for a new strategy to control antibacterial immune responses.

The cGAS/STING-TBK1-IRF Regulatory Axis Orchestrates a Primitive Interferon-Like Antiviral Mechanism in Oyster

Interferon (IFN) system is considered as the first defense line against viral infection, and it has been extensively studied in vertebrates from fish to mammals. In invertebrates, Vagos from arthropod and IFN-like protein (CgIFNLP) from Crassostrea gigas appeared to function as IFN-like antiviral cytokines. In the present study, the CgIFNLP protein in hemocytes was observed to increase after Poly (I:C) stimulation. After CgIFNLP was knocked down by RNAi, the mRNA expression of IFN-stimulated genes (CgISGs) was significantly inhibited. Both cyclic GMP-AMP synthase (CgcGAS) and stimulator of interferon gene (CgSTING) identified from oyster were able to recognize the double-stranded nucleic acid [Poly (I:C) and dsDNA] and expressed at high level after Poly (I:C) stimulation. The expression of CgIFNLP and interferon regulatory factors (CgIRF1/8) and the nuclear translocation of CgIRF8 were all suppressed in CgcGAS-RNAi or CgSTING-RNAi oysters after Poly (I:C) stimulation. The expression level of CgSTING and TANK binding kinase1 (CgTBK1) did not decrease in CgcGAS-RNAi oysters. After CgSTING was knocked down, the high expression of CgTBK1 induced by Poly (I:C) was prevented significantly. These results indicated that there was a primitive IFN-like antiviral mechanism dependent on the cGAS/STING–TBK1–IRFs regulatory axis in mollusks, which was different from the classic cGAS–STING–TBK1 signal pathway in mammals.

To Ubiquitinate or Not to Ubiquitinate: TRIM17 in Cell Life and Death

TRIM17 is a member of the TRIM family, a large class of RING-containing E3 ubiquitin-ligases. It is expressed at low levels in adult tissues, except in testis and in some brain regions. However, it can be highly induced in stress conditions which makes it a putative stress sensor required for the triggering of key cellular responses. As most TRIM members, TRIM17 can act as an E3 ubiquitin-ligase and promote the degradation by the proteasome of substrates such as the antiapoptotic protein MCL1. Intriguingly, TRIM17 can also prevent the ubiquitination of other proteins and stabilize them, by binding to other TRIM proteins and inhibiting their E3 ubiquitin-ligase activity. This duality of action confers several pivotal roles to TRIM17 in crucial cellular processes such as apoptosis, autophagy or cell division, but also in pathological conditions as diverse as Parkinson's disease or cancer. Here, in addition to recent data that endorse this duality, we review what is currently known from public databases and the literature about TRIM17 gene regulation and expression, TRIM17 protein structure and interactions, as well as its involvement in cell physiology and human disorders.

MG53, A Tissue Repair Protein with Broad Applications in Regenerative Medicine

Under natural conditions, injured cells can be repaired rapidly through inherent biological processes. However, in the case of diabetes, cardiovascular disease, muscular dystrophy, and other degenerative conditions, the natural repair process is impaired. Repair of injury to the cell membrane is an important aspect of physiology. Inadequate membrane repair function is implicated in the pathophysiology of many human disorders. Recent studies show that Mitsugumin 53 (MG53), a TRIM family protein, plays a key role in repairing cell membrane damage and facilitating tissue regeneration. Clarifying the role of MG53 and its molecular mechanism are important for the application of MG53 in regenerative medicine. In this review, we analyze current research dissecting MG53′s function in cell membrane repair and tissue regeneration, and highlight the development of recombinant human MG53 protein as a potential therapeutic agent to repair multiple-organ injuries.

TRIM37 Mediates Chemoresistance and Maintenance of Stemness in Pancreatic Cancer Cells via Ubiquitination of PTEN and Activation of the AKT-GSK-3β-β-Catenin Signaling Pathway

Purpose

The tripartite motif-containing family member TRIM37 is involved in a number of important biological and pathological processes, and it has recently been shown to be an essential regulator of protein ubiquitination and a contributor to tumorigenesis. We previously showed that TRIM37 is overexpressed in and promotes the proliferation and invasion of pancreatic cancer (PC).

Methods

Sphere formation, flow cytometric, qRT-PCR, western blot, colony formation, EdU incorporation, mouse xenograft model, TUNEL and IHC assays were performed to detect the role of TRIM37 in stemness and chemoresistance of PC in vitro and in vivo. Bioinformatics analysis and dual-luciferase reporter assays were used to determine which intracellular pathways might mediate the effects of TRIM37 in PC cells. Immunofluorescent(IF) staining, co-immunoprecipitation(CO-IP), protein stability and ubiquitination assays were performed to investigate the relationship between TRIM37 and PTEN.

Results

TRIM37 modulates the ubiquitination and degradation of the tumor suppressor phosphatase and tensin homolog (PTEN), which negatively regulates the AKT–GSK-3β–β-catenin signaling pathway, thereby sustaining aberrant activation of PC cells. High expression of TRIM37 combined with low expression of PTEN correlates with poor survival of PC patients.

Conclusions

Collectively, our results suggest that inhibition of the TRIM37–AKT–GSK-3β–β-catenin axis may be a promising strategy for treatment of PC.

TRIM proteins in neuroblastoma

Neuroblastoma (NB) is the most common extracranial solid tumor in childhood. Outcome for children with high-risk NB remains unsatisfactory. Accumulating evidence suggests that tripartite motif (TRIM) family proteins express diversely in various human cancers and act as regulators of oncoproteins or tumor suppressor proteins. This review summarizes the TRIM proteins involving in NB and the underlying molecular mechanisms. We expect these new insights will provide important implications for the treatment of NB by targeting TRIM proteins.

Tripartite motif 10 regulates cardiac hypertrophy by targeting the PTEN/AKT pathway

The pathogenesis of cardiac hypertrophy is tightly associated with activation of intracellular hypertrophic signalling pathways, which leads to the synthesis of various proteins. Tripartite motif 10 (TRIM10) is an E3 ligase with important functions in protein quality control. However, its role in cardiac hypertrophy was unclear. In this study, neonatal rat cardiomyocytes (NRCMs) and TRIM10-knockout mice were subjected to phenylephrine (PE) stimulation or transverse aortic constriction (TAC) to induce cardiac hypertrophy in vitro and in vivo, respectively. Trim10 expression was significantly increased in hypertrophied murine hearts and PE-stimulated NRCMs. Knockdown of TRIM10 in NRCMs alleviated PE-induced changes in the size of cardiomyocytes and hypertrophy gene expression, whereas TRIM10 overexpression aggravated these changes. These results were further verified in TRIM10-knockout mice. Mechanistically, we found that TRIM10 knockout or knockdown decreased AKT phosphorylation. Furthermore, we found that TRIM10 knockout or knockdown increased ubiquitination of phosphatase and tensin homolog (PTEN), which negatively regulated AKT activation. The results of this study reveal the involvement of TRIM10 in pathological cardiac hypertrophy, which may occur by prompting of PTEN ubiquitination and subsequent activation of AKT signalling. Therefore, TRIM10 may be a promising target for treatment of cardiac hypertrophy.

Emerging Role of TRIM Family Proteins in Cardiovascular Disease

Ubiquitination is one of the basic mechanisms of cell protein homeostasis and degradation and is accomplished by 3 enzymes, E1, E2, and E3. Tripartite motif-containing proteins (TRIMs) constitute the largest subfamily of RING E3 ligases, with >70 current members in humans and mice. These members are involved in multiple biological processes, including growth, differentiation, and apoptosis as well as disease and tumorigenesis. Accumulating evidence has shown that many TRIM proteins are associated with various cardiac processes and pathologies, such as heart development, signal transduction, protein degradation, autophagy mediation, ion channel regulation, congenital heart disease, and cardiomyopathies. In this review, we provide an overview of the TRIM family and discuss its involvement in the regulation of cardiac proteostasis and pathophysiology and its potential therapeutic implications.

TRIM23 overexpression is a poor prognostic factor and contributes to carcinogenesis in colorectal cancer

The tripartite motif (TRIM) family proteins play a great role in carcinogenesis. However, the expression pattern, prognostic value and biological functions of tripartite motif containing 23 (TRIM23) in colorectal cancer (CRC) are poorly understood. Here, we found that TRIM23 is up‐regulated and associated with tumour size, lymph node metastasis, American Joint Committee on Cancer (AJCC) stage and poor prognosis in CRC. Multivariate Cox regression analyses revealed that TRIM23 overexpression could be identified as an independent prognostic factor for CRC. TRIM23 could promote the proliferation of CRC cell in vitro and in vivo; additionally, TRIM23 depletion induced G1­phase arrest. Gene set enrichment analysis (GSEA) revealed that P53 and cell cycle signalling pathway‐related genes were enriched in patients with high TRIM23 expression levels. We show in this study that TRIM23 physically binds to P53 and enhances the ubiquitination of P53, thereby promoting tumour proliferation. Thus, our data indicated that TRIM23 acts as an oncogene in colorectal carcinogenesis and may provide a novel therapeutic target for CRC management.

The Tripartite Nexus: Autophagy, Cancer, and Tripartite Motif-Containing Protein Family Members

Autophagy is a cellular degradative process that has multiple important actions in cancer. Autophagy modulation is under consideration as a promising new approach to cancer therapy. However, complete autophagy dysregulation is likely to have substantial undesirable side effects. Thus, more targeted approaches to autophagy modulation may prove clinically beneficial. One potential avenue to achieving this goal is to focus on the actions of tripartite motif-containing protein family members (TRIMs). TRIMs have key roles in an array of cellular processes, and their dysregulation has been extensively linked to cancer risk and prognosis. As detailed here, emerging data shows that TRIMs can play important yet context-dependent roles in controlling autophagy and in the selective targeting of autophagic substrates. This review covers how the autophagy-related actions of TRIM proteins contribute to cancer and the possibility of targeting TRIM-directed autophagy in cancer therapy.

TRIM59 as a novel molecular biomarker to predict the prognosis of patients with NSCLC

As a member of the tripartite motif family, tripartite motif-containing protein 59 (TRIM59) serves as an E3 ubiquitin ligase in various cellular processes, including intracellular signaling, development, apoptosis, protein quality control, innate immunity, autophagy and carcinogenesis. The present study aimed to investigate the expression and prognostic value of TRIM59 in patients with non-small cell lung cancer (NSCLC). Expression of TRIM59 in patients with NSCLC was measured by immunohistochemistry in tissue microarrays. Datasets from The Cancer Genome Atlas (TCGA) were used to further verify the expression level of TRIM59 in NSCLC, lung adenocarcinoma and lung squamous cell carcinoma (LUSC). The prognostic value of TRIM59 in NSCLC was also analyzed. Immunohistochemistry revealed that TRIM59 was primarily located in the cytoplasm of tumor cells. Analysis of TCGA datasets revealed that TRIM59 was more highly expressed in tumor tissues than in normal tissues (P<0.0001). Furthermore, the TRIM59 expression level was associated with tumor differentiation (P=0.012), while no association was observed between TRIM59 expression and any other clinicopathological parameters. However, the average overall survival rate of patients with NSCLC in the high TRIM59 expression group was significantly lower than that in the low expression group (P=0.014), especially in patients with LUSC (P=0.016) and patients with poor differentiation (P=0.033). The multivariate analysis indicated that high TRIM59 expression is an independent prognostic factor in patients with NSCLC (P=0.018) and was associated with poor prognosis in patients with NSCLC. Therefore, TRIM59 may serve as a novel molecular biomarker to predict the prognosis of patients with NSCLC.

TRIM59 inhibits porcine reproductive and respiratory syndrome virus (PRRSV)-2 replication in vitro

Porcine reproductive and respiratory syndrome (PRRS) caused by PRRS virus (PRRSV), has ranked among the major economically significant pathogen in the global swine industry. The PRRSV nonstructural protein (nsp)11 possesses nidovirus endoribonuclease (NendoU) activity, which is important for virus replication and suppression of the host innate immunity system. Recent proteomic study found that TRIM59 (tripartite motif-containing 59) interacted with the nsp11, albeit the exact role it plays in PRRSV infection remains enigmatic. Herein, we first confirmed the interaction between nsp11 and TRIM59 in co-transfected HEK293T cells and PRRSV-infected pulmonary alveolar macrophages (PAMs). The interacting domains between TRIM59 and nsp11 were further determined to be the N-terminal RING domain in TRIM59 and the C-terminal NendoU domain in nsp11, respectively. Moreover, we reported that overexpression of TRIM59 inhibited PRRSV infection in Marc-145 cells. Conversely, small interfering RNA (siRNA) depletion of TRIM59 resulted in enhanced production of PRRSV in PAMs. Together, these data add TRIM59 as a crucial antiviral component against PRRSV and provide new insights for development of new compounds to reduce PRRSV infection.

Nuclear localization signal in TRIM22 is essential for inhibition of type 2 porcine reproductive and respiratory syndrome virus replication in MARC-145 cells

Porcine reproductive and respiratory syndrome virus (PRRSV) infection causes one of the most economically important swine diseases worldwide. Tripartite motif-containing 22 (TRIM22), a TRIM family protein, has been identified as a crucial restriction factor that inhibits a group of human viruses. Currently, the role of cellular TRIM22 in PRRSV infection remains unclear. In the present study, we analyzed the effect of TRIM22 on PRRSV replication in vitro and explored the underlying mechanism. Ectopic expression of TRIM22 impaired the viral replication, while TRIM22-RNAi favored the replication of PRRSV in MARC-145 cells. Additionally, we observed that TRIM22 deletion SPRY domain or Nuclear localization signal (NLS) losses the ability to inhibit PRRSV replication. Finally, Co-IP analysis identified that TRIM22 interacts with PRRSV nucleocapsid (N) protein through the SPRY domain, while the NLS2 motif of N protein is involved in interaction with TRIM22. Although the concentration of PRRSV N protein was not altered in the presence of TRIM22, the abundance of N proteins from simian hemorrhagic fever virus (SHFV), equine arteritis virus (EAV), and murine lactate dehydrogenase-elevating virus (LDV) diminished considerably with increasing TRIM22 expression. Together, our findings uncover a previously unrecognized role for TRIM22 and extend the antiviral effects of TRIM22 to arteriviruses.

TRIM50 acts as a novel Src suppressor and inhibits ovarian cancer progression

Src is a known proto-oncogene and its aberrant activity is involved in a variety of cancers, including ovarian cancer, whereas the regulatory mechanism of Src has not been fully clarified. In this study, we identified tripartite motif-containing (TRIM) 50 as a novel negative regulator of Src protein. Our data showed that TRIM50 directly interacted with SH3 domain of Src via its B-box domain; and TRIM50 reduced Src stability by inducing RING domain-dependent K48-linked poly-ubiquitous modification. We further demonstrated that TRIM50 acted as a tumor suppressor in ovarian cancer cells by its negative regulation of Src protein. In vivo animal model verified that TRIM50 inhibited the xenograft tumor growth of ovarian cancer by suppressing Src protein. Clinical investigation showed that expression of TRIM50 in clinical specimens was inversely correlated with the clinical stages, pathology grades and lymph node metastatic status of the patients, which indicated the involvement of aberrant TRIM50 expression in disease progression. Further analysis verified the negative correlation between TRIM50 and Src expression in clinical specimens. Altogether, we identified TRIM50 as a novel suppressor of Src protein, and demonstrated that TRIM50 inhibited ovarian cancer progression by targeting Src and reducing its activity, which provided a novel therapeutic strategy for Src over-activated cancers by positive regulation of TRIM50.