Tripartite Motif-containing 28 Research Articles

Overexpression of TRIM3 protects against LPS-induced acute kidney injury via repressing IRF3 pathway and NLRP3 inflammasome.

The pathological process of sepsis involves multiple system organs, including kidney. Sepsis-induced acute kidney injury (AKI) has high morbidity and high mortality. Overproduced inflammatory factors contribute to the occurrence and evolvement of AKI. Here, the role and underlying mechanism of tripartite motif containing 3 (TRIM3) and in AKI was explored. Lipopolysaccharide (LPS) was used for constructing AKI model both in vitro and in vivo. RT-PCR and western blot were performed to detect TRIM3, Interferon regulatory factor 3 (IRF3) and NLRP3-ASC-Caspase1 inflammasome. Upon selectively regulating the TRIM3 or IRF3 expression, the proliferation, apoptosis and inflammatory response were detected. The interaction between TRIM3 and IRF3 was verified by Immunoprecipitation (IP). TRIM3 was down-regulated in mediated injury renal tubular epithelial cell line HK-2 treated with LPS. Overexpression of TRIM3 promoted cell viability and reduced apoptosis. In addition, overexpression of TRIM3 inhibited the expression of inflammatory factors (IL-1β, IL-6, TNF-α and IL-18), dampened the phosphorylation of IRF3 and repressed NLRP3 inflammasome activation. Furthermore, TRIM3 overexpression significantly eased the LPS-induced damage on AKI rat model and decreased the serum creatinine and urea nitrogen levels in rat kidney tissues. The results of immunohistochemistry (IHC) and Western blot manifested that TRIM3 was increased dramatically after TRIM3 was overexpressed in the rat kidney tissues, while IRF3 and NLRP3-ASC-Caspase1 inflammasome were significantly repressed following TRIM3 upregulation in the kidney tissues. Mechanistically, TRIM3 interacted with IRF3 and inhibited its phosphorylation. Overexpression of TRIM3 protected against LPS-induced AKI by inhibiting the IRF3 pathway and NLRP3 inflammasome activation.

MiR-34c-5p mediates the cellular malignant behaviors of oral squamous cell carcinoma through targeted binding of TRIM29.

BackgroundThis investigation examined the effects of the microRNA miR-34c-5p on the proliferation, migration, and invasion of oral squamous cell carcinoma (OSCC) and the mechanisms involved.MethodsThe Gene Expression Omnibus (GEO) database was used to filter the chips, and the GEO2R software (https://www.ncbi.nlm.nih.gov/geo/geo2r/) was used to analyze the microarray data (GSE28100 and GSE45238). Gene set enrichment analysis (GSEA) was used to study the relationship between the expression of miR-34c-5p and the distant metastasis and pathological grade of OSCC. The correlation between TRIM29 (tripartite motif containing 29) expression and the malignant clinical phenotype of OSCC was also examined. The mRNA and protein expression levels of miR-34c-5p and TRIM29 were measured by real time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot analysis. The proliferation, migration, invasion and apoptosis of the human oral squamous carcinoma cell lines CAL-27 and Tca8113 was assessed by performing cell-counting kit-8 (CCK-8) assays, colony formation assays, transwell tests, wound scratch tests and flow cytometry. Luciferase reporter assays were used to predict the relationship between miR-34c-5p and TRIM29. A xenograft nude model was established and used to evaluate the effect of miR-34c-5p on tumor growth in female BALB/c mice.ResultsThe expression of miR-34c-5p was significantly correlated with the proliferation, migration, and metastasis of OSCC. Overexpression of miR-34c-5p promoted the proliferation, migration, and invasion of CAL-27 and Tca8113 cells, and suppressed their apoptosis. Inversely, low expression of miR-34c-5p suppressed the proliferation, migration, and invasion of CAL-27 and Tca8113 cells, and promoted their apoptosis. Overexpression of miR-34c-5p promoted tumor growth in the xenograft nude mice model. The expression of TRIM29 was related to malignant clinical phenotype of OSCC. Overexpression of TRIM29 inhibited the proliferation, migration and invasion of CAL-27 and Tca8113 cell, and induced their apoptosis. TRIM29 knockout had just the opposite effect. Importantly, miR-34c-5p binds to TRIM29 and inhibited TRIM29 expression.ConclusionsMiR-34c-5p regulates the proliferation, migration, invasion, and apoptosis of OSCC through targeted binding of TRIM29. This may represent a novel therapeutic target for the treatment of patients with OSCC.

Role of salt‑inducible kinase2 in the malignant behavior and glycolysis of colorectal cancer cells.

Colorectal cancer (CRC) is the third most common type of cancer worldwide. Currently, surgery, chemotherapy and radiation therapy are the conventional approaches used to treat CRC. However, these therapy strategies cause several side effects. The present study aimed to develop an alternative and more effective treatment approach for patients with CRC. It has been reported that salt-inducible kinase 2 (SIK2) acts as an oncogene. Therefore, in the present study, the expression levels of SIK2 were determined in CRC cells using western blot analysis and reverse transcription-quantitative PCR. In addition, SIK2 was knocked down in CRC cells to evaluate its role in cell proliferation, migration, invasion and glycolysis using Cell Counting Kit-8, wound healing, Transwell assays and glycolysis cell-based assay kit, respectively. Additionally, the target genes of SIK2 were identified using bioinformatics analysis, while SIK2 overexpression experiments were carried out to determine whether SIK2 could regulate CRC cell malignant behavior and glycolysis. The results revealed that SIK2 was upregulated in CRC cells. Furthermore, SIK2 knockdown attenuated CRC cell proliferation, migration, invasion and glycolysis. Bioinformatics analysis predicted that SIK2 could interact with tripartite motif containing 28 (TRIM28), while TRIM28 overexpression could reverse the effects of SIK2 silencing on cell proliferation, migration, invasion and glycolysis. This finding indicated that the aforementioned effects of SIK2 were mediated by regulating TRIM28. In conclusion, the findings of the present study suggested that SIK2 may be involved in CRC carcinogenesis and glycolysis by regulating TRIM28 expression. These findings could provide a novel approach to targeted therapy and clinical diagnosis of CRC in the future.

Fatty Acid Synthase-Suppressor Screening Identifies Sorting Nexin 8 as a Therapeutic Target for NAFLD.

NAFLD is the most prevalent chronic liver disease without any Food and Drug Administration-approved pharmacological intervention in clinic. Fatty acid synthase (FASN) is one of the most attractive targets for NAFLD treatment because of its robust rate-limiting capacity to control hepatic de novo lipogenesis. However, the regulatory mechanisms of FASN in NAFLD and potential therapeutic strategies targeting FASN remain largely unknown. Through a systematic interactomics analysis of FASN-complex proteins, we screened and identified sorting nexin 8 (SNX8) as a binding partner of FASN. SNX8 directly bound to FASN and promoted FASN ubiquitination and subsequent proteasomal degradation. We further demonstrated that SNX8 mediated FASN protein degradation by recruiting the E3 ligase tripartite motif containing 28 (TRIM28) and enhancing the TRIM28-FASN interaction. Notably, Snx8 interference in hepatocytes significantly deteriorated lipid accumulation in vitro, whereas SNX8 overexpression markedly blocked hepatocyte lipid deposition. Furthermore, the aggravating effect of Snx8 deletion on NAFLD was validated in vivo as hepatic steatosis and lipogenic pathways in the liver were significantly exacerbated in Snx8-knockout mice compared to wild-type controls. Consistently, hepatocyte-specific overexpression of Snx8 in vivo markedly suppressed high-fat, high-cholesterol diet (HFHC)-induced hepatic steatosis. Notably, the protective effect of SNX8 against NAFLD was largely dependent on FASN suppression. These data indicate that SNX8 is a key suppressor of NAFLD that promotes FASN proteasomal degradation. Targeting the SNX8-FASN axis is a promising strategy for NAFLD prevention and treatment.

TRIM28 is a transcriptional activator of the mutant TERT promoter in human bladder cancer

Bladder cancer (BC) has a 70% telomerase reverse transcriptase (TERT or hTERT in humans) promoter mutation prevalence, commonly at -124 base pairs, and this is associated with increased hTERT expression and poor patient prognosis. We inserted a green fluorescent protein (GFP) tag in the mutant hTERT promoter allele to create BC cells expressing an hTERT-GFP fusion protein. These cells were used in a fluorescence-activated cell sorting-based pooled CRISPR-Cas9 Kinome knockout genetic screen to identify tripartite motif containing 28 (TRIM28) and TRIM24 as regulators of hTERT expression. TRIM28 activates, while TRIM24 suppresses, hTERT transcription from the mutated promoter allele. TRIM28 is recruited to the mutant promoter where it interacts with TRIM24, which inhibits its activity. Phosphorylation of TRIM28 through the mTOR complex 1 (mTORC1) releases it from TRIM24 and induces hTERT transcription. TRIM28 expression promotes in vitro and in vivo BC cell growth and stratifies BC patient outcome. mTORC1 inhibition with rapamycin analog Ridaforolimus suppresses TRIM28 phosphorylation, hTERT expression, and cell viability. This study may lead to hTERT-directed cancer therapies with reduced effects on normal progenitor cells.

LARP7 Suppresses Endothelial-to-Mesenchymal Transition by Coupling With TRIM28

[Figure: see text].

The Effects of Melatonin Administration on Intestinal Injury Caused by Abdominal Irradiation from Mice.

Intestinal injury caused by ionizing radiation (IR) is a main clinical issue for patients with cancer receiving abdominal or pelvic radiotherapy. Melatonin (N-acetyl-5-methoxytryptamine) is a neurohormone that the pineal gland in the brain normally secretes. The study aimed to disclose the potential function of melatonin in intestinal injury induced by IR and its mechanism. Pretreatment with melatonin enhanced the 30-day survival rate of the irradiated mice and promoted the recovery of the intestinal epithelium and hematopoietic function following abdominal irradiation (ABI). Melatonin altered the gene profile of the small intestines from mice following ABI. The enriched biological process terms for melatonin treatment prior to radiation were mainly involved in the immune process. LPS/IL-1-mediated inhibition of RXR Function, TWEAK signaling, and Toll-like receptor signaling were the most activated canonical pathways targeted by melatonin. An upstream analysis network showed that Tripartite motif-containing 24 (TRIM24) was the most significantly inhibited and S100 calcium binding protein A9 (S100A9) activated. TRIM24 activated atherogenesis and cell viability in breast cancer cell lines and S100A9 inhibited the metabolism of amino acids. Melatonin has radioprotective effects on ABI-caused intestinal injury. The mechanisms behind the beneficial effects of melatonin were involved in activation of the immunity. It is necessary to conduct further experiments to explore the underlying mechanisms.

Tripartite motif-containing 3 (TRIM3) enhances ER signaling and confers tamoxifen resistance in breast cancer

Tamoxifen resistance remains a clinical problem in estrogen receptor (ER)-positive breast cancer. SUMOylation of ERα enhances ERα-induced transcription activity. Tripartite motif-containing (TRIM) proteins are a new class of SUMO E3 ligases, which regulate the SUMOylation of proteins. However, the precise molecular mechanism and function of TRIM3 in SUMOylation and the response to tamoxifen remain unclear. In the present study, we observed that TRIM3 was dramatically overexpressed in breast cancer, which correlated with tamoxifen resistance. Furthermore, TRIM3 overexpression significantly correlated with poor survival of patients with ER+ breast cancer treated with tamoxifen. TRIM3 overexpression conferred cell survival and tumorigenesis, whereas knocking down of TRIM3 reduced these capabilities. Moreover, TRIM3, as a ubiquitin carrier protein 9 (UBC9) binding protein, promoted SUMO modification of estrogen receptor 1 (ESR1) and activated the ER pathway. Silencing UBC9 abolished the function of TRIM3 in regulating tamoxifen resistance. These results suggest TRIM3 as a novel biomarker for breast cancer therapy, indicating that inhibiting TRIM3 combined with tamoxifen might provide a potential treatment for breast cancer.

The deubiquitinase USP10 restores PTEN activity and inhibits non–small cell lung cancer cell proliferation

The phosphatase and tensin homolog deleted on chromosome 10 (PTEN) protein is a key player in tumorigenesis of non–small cell lung cancer (NSCLC) and was recently found to be inactivated by tripartite motif containing 25 (TRIM25)–mediated K63-linked polyubiquitination. However, the deubiquitinase (Dub) coordinate TRIM25 in PTEN ubiquitination is still elusive. In the present study, we found that this K63-linked polyubiquitination could be ablated by the ubiquitin-specific protease 10 (USP10) in a screen against a panel of Dubs. We found using coimmununoprecipitation/immunoblotting that USP10 interacted with PTEN and reduced the K63-linked polyubiquitination of PTEN mediated by TRIM25 in NSCLC cells. Moreover, USP10, but not its inactive C424A deubiquitinating mutant or other Dubs, abolished PTEN from K63-linked polyubiquitination mediated by TRIM25. In contrast to TRIM25, USP10 restored PTEN phosphatase activity and reduced the production of the secondary messenger phosphatidylinositol-3,4,5-trisphosphate, thereby inhibiting AKT/mammalian target of rapamycin progrowth signaling transduction in NSCLC cells. Moreover, USP10 was downregulated in NSCLC cell lines and primary tissues, whereas TRIM25 was upregulated. Consistent with its molecular activity, re-expression of USP10 suppressed NSCLC cell proliferation and migration, whereas knockout of USP10 promoted NSCLC cell proliferation and migration. In conclusion, the present study demonstrates that USP10 coordinates TRIM25 to modulate PTEN activity. Specifically, USP10 activates PTEN by preventing its K63-linked polyubiquitination mediated by TRIM25 and suppresses the AKT/mammalian target of rapamycin signaling pathway, thereby inhibiting NSCLC proliferation, indicating that it may be a potential drug target for cancer treatment.

Potential value of tripartite motif-containing 59 as a biomarker for predicting the prognosis of patients with lung cancer: A protocol for systematic review and meta-analysis.

Background:In recent years, related studies have revealed that tripartite motif-containing 59 (TRIM59) is related to the prognosis of lung cancer. However, these results have not been proved by any evidence. Therefore, this study evaluated the relationship between TRIM59 and the prognosis of lung cancer by carrying out meta-analysis. In addition, we explored the mechanism and related pathways of TRIM59 in lung cancer through bioinformatics analysis.Methods:Comprehensive literature search was performed in China National Knowledge Infrastructure, Chinese Biomedical literature Database, Chinese Scientific and Journal Database, Wan Fang, Web of Science, PubMed, and EMBASE databases, and eligible studies were obtained based on the inclusion and exclusion criteria. The pooled hazard ratios and odds ratios were applied to assess the clinical value of TRIM59 expression for overall survival and clinicopathological features. Meanwhile, meta-analysis was conducted on the Stata 16.0. The mRNA expression level of TRIM59 in lung cancer was analyzed using Oncomine and Gene Expression Profiling Interactive Analysis (GEPIA) database. Gene Set Enrichment Analysis (GSEA) was used to predict the signaling pathways that TRIM59 might be involved in. The correlation between the expression level of TRIM59 in lung cancer and the abundance of immune cell invasion was analyzed by TIMER database. The survival analysis was verified by Kaplan–Meier Plotter database.Results:The results of this meta-analysis would be submitted to peer-reviewed journals for publication.Conclusion:In this study, the application of meta-analysis and bioinformatics analysis will provide evidence support for the study on the prognosis and mechanism of TRIM59 in lung cancer.

KAT6A Acetylation of SMAD3 Regulates Myeloid-Derived Suppressor Cell Recruitment, Metastasis, and Immunotherapy in Triple-Negative Breast Cancer.

Aberrant SMAD3 activation has been implicated as a driving event in cancer metastasis, yet the underlying mechanisms are still elusive. Here, SMAD3 is identified as a nonhistone substrate of lysine acetyltransferase 6A (KAT6A). The acetylation of SMAD3 at K20 and K117 by KAT6A promotes SMAD3 association with oncogenic chromatin modifier tripartite motif‐containing 24 (TRIM24) and disrupts SMAD3 interaction with tumor suppressor TRIM33. This event in turn promotes KAT6A‐acetylated H3K23‐mediated recruitment of TRIM24–SMAD3 complex to chromatin and thereby increases SMAD3 activation and immune response‐related cytokine expression, leading to enhanced breast cancer stem‐like cell stemness, myeloid‐derived suppressor cell (MDSC) recruitment, and triple‐negative breast cancer (TNBC) metastasis. Inhibiting KAT6A in combination with anti‐PD‐L1 therapy in treating TNBC xenograft‐bearing animals markedly attenuates metastasis and provides a significant survival benefit. Thus, the work presents a KAT6A acetylation‐dependent regulatory mechanism governing SMAD3 oncogenic function and provides insight into how targeting an epigenetic factor with immunotherapies enhances the antimetastasis efficacy.

TRIM27 contributes to glomerular endothelial cell injury in lupus nephritis by mediating the FoxO1 signaling pathway

Tripartite motif-containing 27 (TRIM27) belongs to the triple motif (TRIM) protein family, which plays a role in a variety of biological activities. Our previous study showed that the TRIM27 protein was highly expressed in the glomerular endothelial cells of patients suffering from lupus nephritis (LN). However, whether TRIM27 is involved in the injury of glomerular endothelial cells in lupus nephritis remains to be clarified. Here, we detected the expression of the TRIM27 protein in glomerular endothelial cells in vivo and in vitro. In addition, the influence of TRIM27 knockdown on endothelial cell damage in MRL/lpr mice and cultured human renal glomerular endothelial cells (HRGECs) was explored. The results revealed that the expression of TRIM27 in endothelial cells was significantly enhanced in vivo and in vitro. Downregulating the expression of TRIM27 inhibited the breakdown of the glycocalyx and the injury of endothelial cells via the FoxO1 pathway. Moreover, HRGECs transfected with the WT-FoxO1 plasmid showed a reduction in impairment caused by LN plasma. Furthermore, suppression of the protein kinase B (Akt) pathway could attenuate damage by mediating the expression of TRIM27. Thus, the present study showed that TRIM27 participated in the injury of glomerular endothelial cells and served as a potential therapeutic target for the treatment of lupus nephritis.The expression of TRIM27 in MRL/lpr mice and human renal glomerular endothelial cells cultured in vitro is significantly enhanced. Downregulating the expression of TRIM27 inhibits the loss of glycocalyx and damage to endothelial cells through the FoxO1 pathway. In addition, inhibition of the protein kinase B (Akt) pathway can reduce the damage by mediating the expression of TRIM27.

MiR-671-5p repressed progression of papillary thyroid carcinoma via TRIM14.

The pivotal role of dysregulated miRNAs in development of papillary thyroid carcinoma has been emphasized in recent research. miR-671-5p was previously documented to function as a tumor suppressor. However, the role and mechanism of miR-671-5p in progression of papillary thyroid carcinoma remain to be further studied. Data from functional assays indicated that forced expression of miR-671-5p decreased cell viability, repressed cell proliferation, migration, and invasion in papillary thyroid carcinoma cells. In vivo study showed that miR-671-5p overexpression inhibited tumor growth, downregulated Ki67, and decreased tumor volume and weight. Tripartite motif containing 14 (TRIM14) was verified as downstream target of miR-671-5p. The expression of TRIM14 was suppressed by miR-671-5p in papillary thyroid carcinoma. Overexpression of TRIM14 increased cell viability, and promoted the proliferation, migration, and invasion of papillary thyroid carcinoma. Moreover, TRIM14 counteracted the suppressive effect of miR-671-5p overexpression on papillary thyroid carcinoma cell growth. In conclusion, miR-671-5p repressed progression of papillary thyroid carcinoma through downregulation of TRIM14, providing a promising target for therapy of papillary thyroid carcinoma.

Abstract LB245: TRIM29 mediates metastasis though hypoxia-regulated proteins in microsatellite-stable and p53-mutated colorectal cancers

Abstract In the USA, colorectal cancer (CRC) is a leading cause of cancer deaths in men and women. Two primary molecular subtypes of CRCs are those with microsatellite instability (MSI) and those that are microsatellite stable (MSS). MSI-CRCs have a dysfunction of the mismatch repair (MMR) genes and are less aggressive; MSS-CRCs have active mismatch repair genes, account for 85% of sporadic CRCs, and are more aggressive. CRCs with MSI have a favorable prognosis and are candidates for immunotherapy; those with MSS have a poor prognosis and are resistant to various therapies. Our previous gene expression profiling studies of CRCs showed an association of high expression of tripartite motif-containing 29 (TRIM29) with MSS and p53 mutations. TRIM29, also known as ataxia telangiectasia group D-complementing (ATDC) protein, binds to p53 and inhibits its function. Since point mutations of p53 occur in 50% of CRCs and are associated with the MSS phenotype and with aggressiveness of CRCs, we assessed TRIM29 expression in CRC cells exhibiting various microsatellite and p53 status. With RNA sequencing and qPCR validation, we found higher expression of TRIM29 in MSS and p53-mutated types of CRC cells (HT29 and SW480) as compared to cells exhibiting MSI and the p53 wild-type (HCT116, LOVO, RKO and LS174T) as well as cells with MSS and the p53 wild-type (T84). TRIM29 knockdown studies with HT29 and SW480 CRC cells showed that TRIM29 contributes to the aggressive progression of cells with MSS and p53 mutations. Preclinical studies with experimental animals demonstrated that MSS and p53-mutated CRC cells (HT29) with high expression of TRIM29 metastasized more extensively to liver and bone relative to cells with stably inhibited TRIM29. Further, gene expression profiling of stably inhibited TRIM29 cells showed downregulation of P4HA1, ALDOC, and hexokinase2, enzymes that are involved in the hypoxia pathway. In summary, the present studies show that overexpression of TRIM29 contributes to CRC proliferation, invasion, migration, tumor growth, and experimental metastasis. Thus, targeting of TRIM29 with small molecule inhibitors could be an effective strategy for treatment of CRCs with MSS and p53 mutations. This work was supported in part by an NIH grant (3U54CA118948) and by a grant from the ELKUS foundation. Citation Format: Sumit Agarwal, Michael Behring, Prachi Bajpai, Amr Elkohly, Hyung-Gyoon Kim, Darshan S. Chandrashekar, Nirzari Gupta, Sameer Al Diffalha, Sooryanarayana Varambally, Upender Manne. TRIM29 mediates metastasis though hypoxia-regulated proteins in microsatellite-stable and p53-mutated colorectal cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB245.

Effects of TRIM59 on RAW264.7 macrophage gene expression and function

Macrophages have a variety of functions, such as secreting cytokines, phagocytosis, et al. Tripartite motif containing 59 (TRIM59) protein is highly expressed in tumor cells. It can regulate proliferation of tumor cells and promote tumor progression. Recent studies shown that the expression of TRIM59 was different in macrophages when stimulated by different stimuli, however, the effects of TRIM59 on macrophage gene expression profiles and functions are still unknown. In our study, we constructed RAW264.7 macrophages with high and low expression of TRIM59, and used next generation sequencing to explore the effects of TRIM59 on macrophage gene expression profiles. Results showed that TRIM59 affected an abundant number of genes, and may affect phagocytosis and cell cycles. We also examined the expression of surface molecules, secretion of cytokines, phagocytosis, proliferation, and apoptosis of macrophages, and confirmed that TRIM59 increased the expression of FcγRs CD16/32, CD64 and the secretion of TNF-α and IL-10, promoted phagocytosis and proliferation of RAW264.7 cells, inhibited the expression of complement receptor CD11b and antigen presentation related receptors (MHCII, CD80), but TRIM59 had no significant effect on apoptosis. Our study explored the effect of TRIM59 on the gene expression and function of macrophages comprehensively.

TRIM28 regulates SARS-CoV-2 cell entry by targeting ACE2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of coronavirus disease 2019, it binds to angiotensin-converting enzyme 2 (ACE2) to enter into human cells. The expression level of ACE2 potentially determine the susceptibility and severity of COVID-19, it is thus of importance to understand the regulatory mechanism of ACE2 expression. Tripartite motif containing 28 (TRIM28) is known to be involved in multiple processes including antiviral restriction, endogenous retrovirus latency and immune response, it is recently reported to be co-expressed with SARS-CoV-2 receptor in type II pneumocytes; however, the roles of TRIM28 in ACE2 expression and SARS-CoV-2 cell entry remain unclear. This study showed that knockdown of TRIM28 induces ACE2 expression and increases pseudotyped SARS-CoV-2 cell entry of A549 cells and primary pulmonary alveolar epithelial cells (PAEpiCs). In a co-culture model of NK cells and lung epithelial cells, our results demonstrated that NK cells inhibit TRIM28 and promote ACE2 expression in lung epithelial cells, which was partially reversed by depletion of interleukin-2 and blocking of granzyme B in the co-culture medium. Furthermore, TRIM28 knockdown enhanced interferon-γ (IFN-γ)- induced ACE2 expression through a mechanism involving upregulating IFN-γ receptor 2 (IFNGR2) in both A549 and PAEpiCs. The upregulated ACE2 induced by TRIM28 knockdown and co-culture of NK cells was partially reversed by dexamethasone in A549 cells. Our study identified TRIM28 as a novel regulator of ACE2 expression and SARS-CoV-2 cell entry.

Bovine Delta Papillomavirus E5 Oncoprotein Interacts With TRIM25 and Hampers Antiviral Innate Immune Response Mediated by RIG-I-Like Receptors.

Persistent infection and tumourigenesis by papillomaviruses (PVs) require viral manipulation of various of cellular processes, including those involved in innate immune responses. Herein, we showed that bovine PV (BPV) E5 oncoprotein interacts with a tripartite motif-containing 25 (TRIM25) but not with Riplet in spontaneous BPV infection of urothelial cells of cattle. Statistically significant reduced protein levels of TRIM25, retinoic acid-inducible gene I (RIG-I), and melanoma differentiation-associated gene 5 (MDA5) were detected by Western blot analysis. Real-time quantitative PCR revealed marked transcriptional downregulation of RIG-I and MDA5 in E5-expressing cells compared with healthy urothelial cells. Mitochondrial antiviral signalling (MAVS) protein expression did not vary significantly between diseased and healthy cells. Co-immunoprecipitation studies showed that MAVS interacted with a protein network composed of Sec13, which is a positive regulator of MAVS-mediated RLR antiviral signalling, phosphorylated TANK binding kinase 1 (TBK1), and phosphorylated interferon regulatory factor 3 (IRF3). Immunoblotting revealed significantly low expression levels of Sec13 in BPV-infected cells. Low levels of Sec13 resulted in a weaker host antiviral immune response, as it attenuates MAVS-mediated IRF3 activation. Furthermore, western blot analysis revealed significantly reduced expression levels of pTBK1, which plays an essential role in the activation and phosphorylation of IRF3, a prerequisite for the latter to enter the nucleus to activate type 1 IFN genes. Our results suggested that the innate immune signalling pathway mediated by RIG-I-like receptors (RLRs) was impaired in cells infected with BPVs. Therefore, an effective immune response is not elicited against these viruses, which facilitates persistent viral infection.

E3 ubiquitin ligase TRIM24 deficiency promotes NLRP3/caspase-1/IL-1β-mediated pyroptosis in endometriosis.

Endometriosis is an inflammation-dependent disease that shares similarities with malignant tumors including attachment and infiltration. Tripartite motif-containing 24 (TRIM24) has been illustrated in inflammatory responses and gynecological tumors, and Nod-like receptor protein 3 (NLRP3) inflammasome has been implicated in endometriosis. However, the involvement of TRIM24 and the role of NLRP3/caspase-1/interleukin-1β (IL-1β)-mediated pyroptosis in endometriosis remain obscure. In this study, we originally detected the decreased expression of TRIM24 in the ectopic endometrium of endometriosiscompared with the normal endometrium. Then we measured the promoted protein expression of pyroptotic biomarkers (NLRP3, procaspase-1, caspase-1, pro-IL-1β, and IL-1β) using Western blot analysisand the stimulated secretion of IL-1β and IL-18 by enzyme-linked immunosorbent assayin ectopic human endometrial stromal cells (hESC) compared with normal hESC. TRIM24-small-interfering RNA (siTRIM24) was used to silence TRIM24, whereas TRIM24-pcDNA3.1 was used for overexpressing TRIM24. The migration of hESC was determined by a Transwell migration assay. Coimmunoprecipitation and ubiquitination analyses were conducted to explore the interaction between TRIM24 and NLRP3. Subsequently, we found that TRIM24 negatively regulated NLRP3/caspase-1/IL-1β-mediated pyroptosis and cell migration of hESC, and CY-09, the specific inhibitor of NLRP3, could reverse the promoted pyroptosis and cell migration induced by siTRIM24. Furthermore, TRIM24 interacted with NLRP3 and the upregulation of TRIM24 facilitated the ubiquitination of NLRP3 in ectopic hESC. Our findings suggest that TRIM24 may participate in the progression of endometriosis through the NLRP3/caspase-1/IL-1β-mediated pyroptotic pathway via ubiquitination of NLRP3, which reveals the significant molecular mechanism underlying endometriosis.

Tripartite motif protein 11 (TRIM11), an oncogene for human lung cancer via the DUSP6-mediated ERK1/2 signaling pathway

ABSTRACT Evidence suggests that Tripartite Motif Containing 11 (TRIM11) has pro-tumor activity in human non-small cell lung cancer (NSCLC). However, the roles and underlying mechanisms of TRIM11 in NSCLC have not yet been fully elucidated. In this work, human lung cancer cell lines (A549, H446, and H1975) were transfected with siRNA or lentiviruses to knockdown or overexpress TRIM11 and dual-specificity phosphatase 6 (DUSP6). The cell tumor response was assessed by determining the rate of proliferation, apoptosis, the uptake of 2-[N-(7-nitrobenz-2-oxa-1, 3-diaxol-4-yl) amino]-2-deoxyglucose (2-NBDG), and the secretion of lactic acid (LD). Dominant-negative (dn)-MEK1 was used to block the ERK1/2 pathway. The mechanism was investigated by assessing the protein levels of pyruvate kinase isozymes M2 (PKM2) and DUSP6, as well as the activation of ERK1/2 pathway. Our data confirmed the anti-cancer effect of siTRIM11 in human lung cancer by demonstrating inhibition of cancer cell proliferation, induction of apoptosis, prevention of 2-NBDG uptake, suppression of LD production, and prevention of lung cancer cell (A549) tumorigenicity in nude mice. The underlying mechanism involved the up-regulation of DUSP6 and the inhibition of ERK1/2 activity. Overexpression of TRIM11 induced tumorigenesis of NSCLC in vitro, and the activation of ERK1/2 was significantly reversed by DUSP6 overexpression or additional dn-MEK1 treatment. Interestingly, we confirmed TRIM11 as a deubiquitinase that regulated DUSP6 accumulation, indicating that lung cancer progression is regulated via the DUSP6-ERK1/2 pathway. In conclusion, TRIM11 is an oncogene in NSCLC, likely through the DUSP6-mediated ERK1/2 signaling pathway.

Gain of LINC00624 Enhances Liver Cancer Progression by Disrupting the Histone Deacetylase 6/Tripartite Motif Containing 28/Zinc Finger Protein 354C Corepressor Complex.

Long noncoding RNAs (lncRNAs) are involved in almost every stage of tumor initiation and progression. Here, we have identified an antisense lncRNA, LINC00624, that arises from the antisense strand of chromo-domain-helicase-DNA-binding protein 1-like (CHD1L), located on chr1q21.1, with significant copy number gain and transcriptional activation of CHD1L and B-cell CLL/lymphoma 9 protein (BCL9), in hepatocellular carcinoma (HCC). Overexpression of LINC00624 enhances tumor growth and metastasis in vitro and in vivo. Mechanistically, higher levels of LINC00624 strengthen the interaction between histone deacetylase 6 (HDAC6) and tripartite motif containing 28 (TRIM28), which accelerates HDAC6 ubiquitination and degradation. Moreover, LINC00624 binds to the RBCC domain of TRIM28, inhibits trimer formation, and weakens the interaction between TRIM28 and zinc finger protein 354C (ZNF354C). Thus, LINC00624 overexpression disrupts the formation of the HDAC6-TRIM28-ZNF354C transcriptional corepressor complex, resulting in the dissociation of the complex from the promoter of CHD1L and BCL9, thereby removing transcription inhibition. Our findings suggest that LINC00624 acts as a molecular decoy that sequesters the HDAC6-TRIM28-ZNF354C transcriptional corepressor complex away from the specific genomic loci, and that it can potentially be a therapeutic target in HCC.