An investigation of the molecular characterization of the tripartite motif (TRIM) family and primary validation of TRIM31 in gastric cancer.

Most TRIM family members characterized by the E3-ubiquitin ligases, participate in ubiquitination and tumorigenesis. While there is a dearth of a comprehensive investigation for the entire family in gastric cancer (GC). By combining the TCGA and GEO databases, common TRIM family members (TRIMs) were obtained to investigate gene expression, gene mutations, and clinical prognosis. On the basis of TRIMs, a consensus clustering analysis was conducted, and a risk assessment system and prognostic model were developed. Particularly, TRIM31 with clinical prognostic and diagnostic value was chosen for single-gene bioinformatics analysis, in vitro experimental validation, and immunohistochemical analysis of clinical tissue microarrays. The combined dataset consisted of 66 TRIMs, of which 52 were differentially expressed and 43 were differentially prognostic. Significant survival differences existed between the gene clusters obtained by consensus clustering analysis. Using 4 differentially expressed genes identified by multivariate Cox regression and LASSO regression, a risk scoring system was developed. Higher risk scores were associated with a poorer prognosis, suppressive immune cell infiltration, and drug resistance. Transcriptomic data and clinical sample tissue microarrays confirmed that TRIM31 was highly expressed in GC and associated with a poor prognosis. Pathway enrichment analysis, cell migration and colony formation assay, EdU assay, reactive oxygen species (ROS) assay, and mitochondrial membrane potential assay revealed that TRIM31 may be implicated in cell cycle regulation and oxidative stress-related pathways, contribute to gastric carcinogenesis. This study investigated the whole functional and expression profile and a risk score system based on the TRIM family in GC. Further investigation centered around TRIM31 offers insight into the underlying mechanisms of action exhibited by other members of its family in the context of GC.

KL-Biome (Postbiotic Formulation of Lactiplantibacillus plantarum KM2) Improves Dexamethasone-Induced Muscle Atrophy in Mice.

Sarcopenia refers to an age-related decrease in muscle mass and strength. The gut-muscle axis has been proposed as a promising target to alleviate muscle atrophy. The effect of KL-Biome-a postbiotic preparation comprising heat-killed Lactiplantibacillus plantarum KM-2, its metabolites, and an excipient (soybean powder)-on muscle atrophy was evaluated using dexamethasone (DEX)-induced atrophic C2C12 myoblasts and C57BL/6J mice. KL-Biome significantly downregulated the expression of genes (Atrogin-1 and MuRF1) associated with skeletal muscle degradation but increased the anabolic phosphorylation of FoxO3a, Akt, and mTOR in C2C12 cells. Oral administration of KL-Biome (900 mg/kg) for 8 weeks significantly improved muscle mass, muscle function, and serum lactate dehydrogenase levels in DEX-treated mice. KL-Biome administration increased gut microbiome diversity and reversed DEX-mediated gut microbiota alterations. Furthermore, it significantly increased the relative abundances of the genera Subdologranulum, Alistipes, and Faecalibacterium prausnitzii, which are substantially involved in short-chain fatty acid production. These findings suggest that KL-Biome exerts beneficial effects on muscle atrophy by regulating gut microbiota.

TRIM50 inhibits glycolysis and the malignant progression of gastric cancer by ubiquitinating PGK1.

Ubiquitination plays a pivotal regulatory role in tumor progression. Among the components of the ubiquitin-proteasome system (UPS), ubiquitin-protein ligase E3 has emerged as a key molecule. Nevertheless, the biological functions of E3 ubiquitin ligases and their potential mechanisms orchestrating glycolysis in gastric cancer (GC) remain to be elucidated. In this study, we conducted a comprehensive transcriptomic analysis to identify the core E3 ubiquitin ligases in GC, followed by extensive validation of the expression patterns and clinical significance of Tripartite motif-containing 50 (TRIM50) both in vitro and in vivo. Remarkably, we found that TRIM50 was downregulated in GC tissues, associated with malignant progression and poor patient survival. Functionally, overexpression of TRIM50 suppressed GC cell proliferation and indirectly mitigated the invasion and migration of GC cells by inhibiting the M2 polarization of tumor-associated macrophages (TAMs). Mechanistically, TRIM50 inhibited the glycolytic pathway by ubiquitinating Phosphoglycerate Kinase 1 (PGK1), thereby directly suppressing GC cell proliferation. Simultaneously, the reduction in lactate led to diminished M2 polarization of TAMs, indirectly inhibiting the invasion and migration of GC cells. Notably, the downregulation of TRIM50 in GC was mediated by the METTL3/YTHDF2 axis in an m6A-dependent manner. In our study, we definitively identified TRIM50 as a tumor suppressor gene (TSG) that effectively inhibits glycolysis and the malignant progression of GC by ubiquitinating PGK1, thus offering novel insights and promising targets for the diagnosis and treatment of GC.

TRIM59 deficiency promotes M1 macrophage activation and inhibits colorectal cancer through the STAT1 signaling pathway.

Tumor-associated macrophages play a crucial role in the tumor microenvironment. Tripartite motif 59 (TRIM59), a member of the tripartite motif (TRIM) family, is known to be associated with immunological diseases and macrophage activation. The functional and molecular mechanisms by which TRIM59 affects the occurrence and development of colorectal cancer (CRC) through macrophages are still not well understood. To address this, we generated macrophage-specific TRIM59 conditional knockout mice and utilized these mice to establish colitis-associated cancer and MC38 transplanted CRC models for further investigation. We found that the deficiency of TRIM59 in macrophages inhibited colorectal tumorigenesis in mice. This tumor-suppressive effect was achieved by promoting the activation of M1 macrophages via STAT1 signaling pathway. Further mechanistic studies revealed that TRIM59 could regulate macrophage polarization by ubiquitinating and degrading STAT1. These findings provide evidence that TRIM59 deficiency promotes M1 macrophage activation and inhibits CRC through the STAT1 signaling pathway, suggesting that the TRIM59/STAT1 signaling pathway may be a promising target for CRC.

TRIM26 facilitates PRV infection through NDP52-mediated autophagic degradation of MAVS.

Pseudorabies virus (PRV) has evolved multiple strategies to evade host antiviral responses to benefit virus replication and establish persistent infection. Recently, tripartite motif 26 (TRIM26), a TRIM family protein, has been shown to be involved in a broad range of biological processes involved in innate immunity, especially in regulating viral infection. Herein, we found that the expression of TRIM26 was significantly induced after PRV infection. Surprisingly, the overexpression of TRIM26 promoted PRV production, while the depletion of this protein inhibited virus replication, suggesting that TRIM26 could positively regulate PRV infection. Further analysis revealed that TRIM26 negatively regulates the innate immune response by targeting the RIG-I-triggered type I interferon signalling pathway. TRIM26 was physically associated with MAVS independent of viral infection and reduced MAVS expression. Mechanistically, we found that NDP52 interacted with both TRIM26 and MAVS and that TRIM26-induced MAVS degradation was almost entirely blocked in NDP52-knockdown cells, demonstrating that TRIM26 degrades MAVS through NDP52-mediated selective autophagy. Our results reveal a novel mechanism by which PRV escapes host antiviral innate immunity and provide insights into the crosstalk among virus infection, autophagy, and the innate immune response.

TRIM26 deficiency enhancing liver regeneration through macrophage polarization and ß-catenin pathway activation.

Liver regeneration is a complex process involving the crosstalk between parenchymal and non-parenchymal cells, especially macrophages. However, the underlying mechanisms remain incompletely understood. Here, we identify the E3 ubiquitin ligase TRIM26 as a crucial regulator of liver regeneration. Following partial hepatectomy or acute liver injury induced by carbon tetrachloride, Trim26 knockout mice exhibit enhanced hepatocyte proliferation compared to wild-type controls, while adeno-associated virus (AAV)-mediated overexpression of Trim26 reverses the promotional effects. Mechanistically, Trim26 deficiency promotes the recruitment of macrophages to the liver and their polarization towards pro-inflammatory M1 phenotype. These M1 macrophages secrete Wnts, including Wnt2, which subsequently stimulate hepatocyte proliferation through the activation of Wnt/ß-catenin signaling. In hepatocytes, Trim26 knockdown reduces the ubiquitination and degradation of ß-catenin, thereby further enhancing Wnt/ß-catenin signaling. Pharmacological inhibition of Wnt/ß-catenin pathway by ICG-001 or depletion of macrophages by clodronate liposomes diminishes the pro-regenerative effects of Trim26 deficiency. Moreover, bone marrow transplantation experiments provide evidence that Trim26 knockout in myeloid cells alone can also promote liver regeneration, highlighting the critical role of macrophage Trim26 in this process. Taken together, our study uncovers TRIM26 as a negative regulator of liver regeneration by modulating macrophage polarization and Wnt/ß-catenin signaling in hepatocytes, providing a potential therapeutic target for promoting liver regeneration in clinical settings.

Neddylation activated TRIM25 desensitizes triple-negative breast cancer to paclitaxel via TFEB-mediated autophagy.

BACKGROUND: Paclitaxel (PTX) treatment resistance is an important factor leading to poor prognosis in triple-negative breast cancer (TNBC), therefore there is an urgent need to identify new target for combination therapy. Neddylation is a post-translational process that introduces a ubiquitin-like protein called neural precursor cell expressed developmentally downregulated protein 8 (NEDD8). Previous studies have found that neddylation is activated in multiple tumors, but its relationship with PTX chemotherapy sensitivity has not been reported. METHODS: Differences in UBC12 and NEDD8 expression levels between PTX-sensitive and PTX-insensitive TNBC tissues were validated using public databases and immunohistochemistry. The in vitro and in vivo functional experiments were used to observe the effect of neddylation inhibition combined with PTX therapy on tumor progression. Co-IP, western blot and PCR assays were used to investigate the molecular mechanisms. Molecular docking was used to simulate the protein binding of UBC12 and TRIM25. Molecular dynamics simulation was used to observe the changes in TRIM25 protein conformation. RESULTS: We found that in TNBC that is insensitive to PTX, NEDD8 and NEDD8 conjugating enzyme UBC12 are highly expressed. Treatment with the NEDD8-activating enzyme (NAE) inhibitor mln4924 or knockdown of UBC12 significantly increased the sensitivity of the tumor to PTX, and this increase in sensitivity is related to UBC12-mediated autophagy activation. Mechanistically, UBC12 can transfer NEDD8 to E3 ubiquitin ligase tripartite motif containing 25 (TRIM25) at K117. Molecular dynamics simulations indicate that the neddylation modification of TRIM25 reduces steric hindrance in its RING domain, facilitating the binding of TRIM25 and ubiquitylated substrates. Subsequently, TRIM25 promotes the nuclear translocation of transcription factor EB (TFEB) and transcription of autophagy related genes by increasing K63-polyubiquitination of TFEB, thereby reducing tumor sensitivity to PTX. CONCLUSIONS: Neddylation is activated in PTX-insensitive TNBC. Specifically, autophagy gene transcriptional activation mediated by the UBC12/TRIM25/TFEB axis reduces TNBC sensitivity to PTX. Neddylation suppression combination with PTX treatment shows a synergistic anti-tumor effect.

The Extract of Gloiopeltis tenax Enhances Myogenesis and Alleviates Dexamethasone-Induced Muscle Atrophy.

The decline in the function and mass of skeletal muscle during aging or other pathological conditions increases the incidence of aging-related secondary diseases, ultimately contributing to a decreased lifespan and quality of life. Much effort has been made to surmise the molecular mechanisms underlying muscle atrophy and develop tools for improving muscle function. Enhancing mitochondrial function is considered critical for increasing muscle function and health. This study is aimed at evaluating the effect of an aqueous extract of Gloiopeltis tenax (GTAE) on myogenesis and muscle atrophy caused by dexamethasone (DEX). The GTAE promoted myogenic differentiation, accompanied by an increase in peroxisome proliferator-activated receptor γ coactivator α (PGC-1α) expression and mitochondrial content in myoblast cell culture. In addition, the GTAE alleviated the DEX-mediated myotube atrophy that is attributable to the Akt-mediated inhibition of the Atrogin/MuRF1 pathway. Furthermore, an in vivo study using a DEX-induced muscle atrophy mouse model demonstrated the efficacy of GTAE in protecting muscles from atrophy and enhancing mitochondrial biogenesis and function, even under conditions of atrophy. Taken together, this study suggests that the GTAE shows propitious potential as a nutraceutical for enhancing muscle function and preventing muscle wasting.

Interleukin 27, Similar to Interferons, Modulates Gene Expression of Tripartite Motif (TRIM) Family Members and Interferes with Mayaro Virus Replication in Human Macrophages.

BACKGROUND: The Tripartite motif (TRIM) family includes more than 80 distinct human genes. Their function has been implicated in regulating important cellular processes, including intracellular signaling, transcription, autophagy, and innate immunity. During viral infections, macrophages are key components of innate immunity that produce interferons (IFNs) and IL27. We recently published that IL27 and IFNs induce transcriptional changes in various genes, including those involved in JAK-STAT signaling. Furthermore, IL27 and IFNs share proinflammatory and antiviral pathways in monocyte-derived macrophages (MDMs), resulting in both common and unique expression of inflammatory factors and IFN-stimulated genes (ISGs) encoding antiviral proteins. Interestingly, many TRIM proteins have been recognized as ISGs in recent years. Although it is already very well described that TRIM expression is induced by IFNs, it is not fully understood whether TRIM genes are induced in macrophages by IL27. Therefore, in this study, we examined the effect of stimulation with IL27 and type I, II, and III IFNs on the mRNA expression profiles of TRIM genes in MDMs. METHODS: We used bulk RNA-seq to examine the TRIM expression profile of MDMs treated with IFNs or IL27. Initially, we characterized the expression patterns of different TRIM subfamilies using a heatmap. Subsequently, a volcano plot was employed to identify commonly differentially expressed TRIM genes. Additionally, we conducted gene ontology analysis with ClueGO to explore the biological processes of the regulated TRIMs, created a gene-gene interaction network using GeneMANIA, and examined protein-protein interactions with the STRING database. Finally, RNA-seq data was validated using RT-qPCR. Furthermore, the effect of IL27 on Mayaro virus replication was also evaluated. RESULTS: We found that IL27, similar to IFNs, upregulates several TRIM genes' expression in human macrophages. Specifically, we identified three common TRIM genes (TRIM19, 21, and 22) induced by IL27 and all types of human IFNs. Additionally, we performed the first report of transcriptional regulation of TRIM19, 21, 22, and 69 genes in response to IL27. The TRIMs involved a broad range of biological processes, including defense response to viruses, viral life cycle regulation, and negative regulation of viral processes. In addition, we observed a decrease in Mayaro virus replication in MDMs previously treated with IL27. CONCLUSIONS: Our results show that IL27, like IFNs, modulates the transcriptional expression of different TRIM-family members involved in the induction of innate immunity and an antiviral response. In addition, the functional analysis demonstrated that, like IFN, IL27 reduced Mayaro virus replication in MDMs. This implies that IL27 and IFNs share many similarities at a functional level. Moreover, identifying distinct TRIM groups and their differential expressions in response to IL27 provides new insights into the regulatory mechanisms underlying the antiviral response in human macrophages.

Adipose stem cell­derived exosomes promote high glucose-induced wound healing by regulating the TRIM32/STING axis.

Refractory diabetic wounds are still a clinical challenge that can cause persistent inflammation and delayed healing. Exosomes of adipose stem cells (ADSC-exos) are the potential strategy for wound repair; however, underlying mechanisms remain mysterious. In this study, we isolated ADSC-exos and identified their characterization. High glucose (HG) stimulated human umbilical vein endothelial cells (HUVECs) to establish in vitro model. The biological behaviors were analyzed by Transwell, wound healing, and tube formation assays. The underlying mechanisms were analyzed using quantitative real-time PCR, co-immunoprecipitation (Co-IP), IP, and western blot. The results showed that ADSC-exos promoted HG-inhibited cell migration and angiogenesis. In addition, ADSC-exos increased the levels of TRIM32 in HG-treated HUVECs, which promoted the ubiquitination of STING and downregulated STING protein levels. Rescue experiments affirmed that ADSC-exos promoted migration and angiogenesis of HG-treated HUVECs by regulating the TRIM32/STING axis. In conclusion, ADSC-exos increased the levels of TRIM32, which interacted with STING and promoted its ubiquitination, downregulating STING levels, thus promoting migration and angiogenesis of HG-treated HUVECs. The findings suggested that ADSC-exos could promote diabetic wound healing and demonstrated a new mechanism of ADSC-exos.

Tripartite Motif-Containing Protein 65 (TRIM65) Inhibits Hepatitis B Virus Transcription.

Tripartite motif (TRIM) proteins, comprising a family of over 100 members with conserved motifs, exhibit diverse biological functions. Several TRIM proteins influence viral infections through direct antiviral mechanisms or by regulating host antiviral innate immune responses. To identify TRIM proteins modulating hepatitis B virus (HBV) replication, we assessed 45 human TRIMs in HBV-transfected HepG2 cells. Our study revealed that ectopic expression of 12 TRIM proteins significantly reduced HBV RNA and subsequent capsid-associated DNA levels. Notably, TRIM65 uniquely downregulated viral pregenomic (pg) RNA in an HBV-promoter-specific manner, suggesting a targeted antiviral effect. Mechanistically, TRIM65 inhibited HBV replication primarily at the transcriptional level via its E3 ubiquitin ligase activity and intact B-box domain. Though HNF4α emerged as a potential TRIM65 substrate, disrupting its binding site on the HBV genome did not completely abolish TRIM65's antiviral effect. In addition, neither HBx expression nor cellular MAVS signaling was essential to TRIM65-mediated regulation of HBV transcription. Furthermore, CRISPR-mediated knock-out of TRIM65 in the HepG2-NTCP cells boosted HBV infection, validating its endogenous role. These findings underscore TRIM proteins' capacity to inhibit HBV transcription and highlight TRIM65's pivotal role in this process.

Targeting TRIM40 signaling reduces esophagus cancer development: A mechanism involving in protection of oroxylin A.

Oroxylin A (OA), a naturally active O-methylated flavone derived from Scutellaria baicalensis, is regarded as a potential drug with strong anticancer effects. Unfortunately, our understanding of the antineoplastic mechanism of oral exposure to such flavonoids is inadequate. Growing evidence has confirmed the important role of OA in the regulation of oxidative stress- and inflammatory-response-induced tissue injury. However, it remains unknown whether OA is capable of mitigating esophagus cancer (EC) progression and its potential molecular mechanism. Furthermore, the tripartite motif containing 40 (TRIM40) is a ubiquitin ligase that mediates the immune response. The potential molecular function of TRIM40 in regulating EC is largely unknown. We confirmed that OA-triggered oxidative stress markedly upregulates TRIM40. During the OA challenge, increased TRIM40 reduced oxidative stress and promoted the ER stress response. Inversely, deletion of TRIM40 facilitated oxidative stress and blocked cancer cell growth in vivo and in vitro. Mechanistically, in response to OA treatment, TRIM40 directly interacts with Keap1 and promotes ubiquitin-proteasome degradation, thus leading to the promotion of Nrf2 nuclear translocation and its downstream cascade activation, which increases antioxidant defense and cell survival. TRIM40 expression was positively correlated with Nrf2 expression and negatively associated with Keap1 expression in EC xenografts and human specimens. In addition, high TRIM40 expression correlates with poor patient survival in EC. The findings suggested that oral exposure to OA significantly mitigates EC development by targeting TRIM40 activity. These findings further elucidated the potential role of TRIM40 in EC progression by mediating Keap1 degradation, which could be considered a therapeutic target for the treatment of such a disease.

Inflammatory Cytokine-Induced Muscle Atrophy and Weakness Can Be Ameliorated by an Inhibition of TGF-ß-Activated Kinase-1.

Chronic inflammation causes muscle wasting. Because most inflammatory cytokine signals are mediated via TGF-ß-activated kinase-1 (TAK1) activation, inflammatory cytokine-induced muscle wasting may be ameliorated by the inhibition of TAK1 activity. The present study was undertaken to clarify whether TAK1 inhibition can ameliorate inflammation-induced muscle wasting. SKG/Jcl mice as an autoimmune arthritis animal model were treated with a small amount of mannan as an adjuvant to enhance the production of TNF-α and IL-1ß. The increase in these inflammatory cytokines caused a reduction in muscle mass and strength along with an induction of arthritis in SKG/Jcl mice. Those changes in muscle fibers were mediated via the phosphorylation of TAK1, which activated the downstream signaling cascade via NF-κB, p38 MAPK, and ERK pathways, resulting in an increase in myostatin expression. Myostatin then reduced the expression of muscle proteins not only via a reduction in MyoD1 expression but also via an enhancement of Atrogin-1 and Murf1 expression. TAK1 inhibitor, LL-Z1640-2, prevented all the cytokine-induced changes in muscle wasting. Thus, TAK1 inhibition can be a new therapeutic target of not only joint destruction but also muscle wasting induced by inflammatory cytokines.

TRIM47 promotes HDM-induced bronchial epithelial pyroptosis by regulating NEMO ubiquitination to activate NF-κB/NLRP3 signaling.

Asthma is an inflammatory disease. Airway epithelial cell pyroptosis and cytokine secretion promote asthma progression. Tripartite motif 47 (TRIM47) belongs to the E3 ubiquitin ligase family and is associated with apoptosis and inflammation in a range of diseases. However, the role of TRIM47 in asthma has not been explored. In this study, the human bronchial epithelial cell line BEAS-2B was treated with house dust mite (HDM) and TRIM47 expression was detected by RT-qPCR and Western blot. After transfection with TRIM47 interfering and overexpressing plasmids, the synthesis and secretion of cytokines, as well as pyroptosis-related indicators, were examined. Nuclear factor kappa-B (NF-κB) pathway proteins and nod-like receptor protein 3 (NLRP3) inflammasome were measured to explore the mechanism of TRIM47 action. In addition, the effect of TRIM47 on the level of NF-κB essential modulator (NEMO) ubiquitination was detected by an immunoprecipitation assay. The results showed that TRIM47 was upregulated in HDM-induced BEAS-2B cells and that TRIM47 mediated HDM-induced BEAS-2B cell pyroptosis and cytokine secretion. Mechanistically, TRIM47 promoted the K63-linked ubiquitination of NEMO and facilitated NF-κB/NLRP3 pathway activation. In conclusion, TRIM47 may promote cytokine secretion mediating inflammation and pyroptosis in bronchial epithelial cells by activating the NF-κB/NLRP3 pathway. Therefore, TRIM47 may be a potential therapeutic target for HDM-induced asthma.

Oleocanthal Protects C2C12 Myotubes against the Pro-Catabolic and Anti-Myogenic Action of Stimuli Able to Induce Muscle Wasting In Vivo.

Oleocanthal (OC) is a monophenol of extra-virgin olive oil (EVOO) endowed with antibiotic, cardioprotective and anticancer effects, among others, mainly in view of its antioxidant and anti-inflammatory properties. OC has been largely investigated in terms of its anticancer activity, in Alzheimer disease and in collagen-induced arthritis; however, the possibility that it can also affect muscle biology has been totally overlooked so far. This study is the first to describe that OC modulates alterations induced in C2C12 myotubes by stimuli known to induce muscle wasting in vivo, namely TNF-α, or in the medium conditioned by the C26 cachexia-inducing tumor (CM-C26). C2C12 myotubes were exposed to CM-C26 or TNF-α in the presence or absence of OC for 24 and 48 h and analyzed by immunofluorescence and Western blotting. In combination with TNF-α or CM-C26, OC was revealed to be able to restore both the myotube's original size and morphology and normal levels of both atrogin-1 and MuRF1. OC seems unable to impinge on the autophagic-lysosomal proteolytic system or protein synthesis. Modulations towards normal levels of the expression of molecules involved in myogenesis, such as Pax7, myogenin and MyHC, were also observed in the myotube cultures exposed to OC and TNF-α or CM-C26. In conclusion, the data presented here show that OC exerts a protective action in C2C12 myotubes exposed to TNF-α or CM-C26, with mechanisms likely involving the downregulation of ubiquitin-proteasome-dependent proteolysis and the partial relief of myogenic differentiation impairment.

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.

Degradation of TRIM32 is induced by RTA for Kaposi's sarcoma-associated herpesvirus lytic replication.

TRIM32 is often aberrantly expressed in many types of cancers. Kaposi's sarcoma-associated herpesvirus (KSHV) is linked with several human malignancies, including Kaposi's sarcoma and primary effusion lymphomas (PELs). Increasing evidence has demonstrated the crucial role of KSHV lytic replication in viral tumorigenesis. However, the role of TRIM32 in herpesvirus lytic replication remains unclear. Here, we reveal that the expression of TRIM32 is upregulated by KSHV in latency, and reactivation of KSHV lytic replication leads to the inhibition of TRIM32 in PEL cells. Strikingly, RTA, the master regulator of lytic replication, interacts with TRIM32 and dramatically promotes TRIM32 for degradation via the proteasome systems. Inhibition of TRIM32 induces cell apoptosis and in turn inhibits the proliferation and colony formation of KSHV-infected PEL cells and facilitates the reactivation of KSHV lytic replication and virion production. Thus, our data imply that the degradation of TRIM32 is vital for the lytic activation of KSHV and is a potential therapeutic target for KSHV-associated cancers. IMPORTANCE: TRIM32 is associated with many cancers and viral infections; however, the role of TRIM32 in viral oncogenesis remains largely unknown. In this study, we found that the expression of TRIM32 is elevated by Kaposi's sarcoma-associated herpesvirus (KSHV) in latency, and RTA (the master regulator of lytic replication) induces TRIM32 for proteasome degradation upon viral lytic reactivation. This finding provides a potential therapeutic target for KSHV-associated cancers.

Oxymatrine induces apoptosis in non-small cell lung cancer cells by downregulating TRIM46.

Sophora flavescens Aiton, a traditional Chinese medicine that was supposed to predominantly play an anti-inflammatory role, has been used to treat multiple diseases, including cancer, for over two thousand years. Recently, it has attracted increasing attention due to the anti-tumor properties of Oxymatrine, one of the most active alkaloids extracted from S. flavescens. This study aims to explore it's anti-tumor effects in non-small cell lung cancer (NSCLC) and the underlying mechanisms. We first investigated the effects of oxymatrine on cell apoptosis in lung cancer cell lines A549 and PC9 as well as explored related genes in regulating the apoptosis by transcriptome analysis. Subsequently, to further study the role of TRIM46, we constructed two types of TRIM46 over-expression cells (A549TRIM46+ and PC9TRIM46+ cells) and then investigated the effect of TRIM46 on oxymatrine-induced apoptosis. Moreover, we explored the effect of TRIM46 on downstream signaling pathways. Transcriptome analysis suggested that shared differentially expressed genes (DEGs) in A549 and PC9 cells treated with oxymatrine were CACNA1I, PADI2, and TRIM46. According to TCGA database analysis, the abundance of TRIM46 expression was higher than CACNA1I, and PADI2 in lung cancer tissues, then was selected as the final DEG for subsequent studies. We observed that oxymatrine resulted in down-expression of TRIM46 as well as induced the apoptosis of the cancer cells in a dose- and time-dependent manner. Meanwhile, we found that apoptosis induced by oxymatrine was inhibited by over-expressing TRIM46. Furthermore, our study indicated that the NF-κB signaling pathway was involved in apoptosis suppressed by TRIM46. We conclude that TRIM46 is the direct target of oxymatrine to induce anti-tumor apoptosis and may activate the downstream NF-κB signaling pathway.