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Abstract Background Age‐related sarcopenia, characterized by reduced skeletal muscle mass and function, significantly affects the health of the elderly individuals. Oxidative stress plays a crucial role in the development of sarcopenia. Tripartite motif containing 16 (TRIM16) is implicated in orchestrating antioxidant responses to mitigate oxidative stress, yet its regulatory role in skeletal muscle remains unclear. This study aims to elucidate the impact of TRIM16 on enhancing antioxidant response through SIRT‐1, consequently mitigating age‐related oxidative stress, and ameliorating muscle atrophy. Methods Aged mouse models were established utilizing male mice at 18 months with D‐galactose (D‐gal, 200 mg/kg) intervention and at 24 months with natural aging, while 3‐month‐old young mice served as controls. Muscle cell senescence was induced in C2C12 myoblasts using 30 g/L D‐gal. TRIM16 was overexpressed in the skeletal muscle of aged mice and silenced/overexpressed in C2C12 myoblasts. The effects of TRIM16 on skeletal muscle mass, grip strength, morphological changes, myotube formation, myogenic differentiation, and muscle atrophy indicators were evaluated. Reactive oxygen species (ROS) levels and oxidative stress‐related parameters were measured. The SIRT‐1 inhibitor EX‐527 was employed to elucidate the protective role of TRIM16 mediated through SIRT‐1. Results Aged mice displayed significant reductions in lean mass (−11.58%; −14.47% vs. young, P

Background: Radiotherapy is widely employed in colorectal cancer (CRC) treatment but is often compromised by developed radioresistance. This study explored the mechanism of long non-coding RNA ovarian tumor domain containing 6B-antisense RNA1 (lncRNA OTUD6B-AS1) in CRC radioresistance through tripartite motif 16 (TRIM16). Methods: CRC and non-cancerous tissues were collected and radioresistant CRC cells were established, with real-time quantitative polymerase chain reaction to determine gene expression in tissues and cells. Radioresistance was evaluated by cell counting kit-8 assay and immunofluorescence (γ-H2AX) and ferroptosis was tested by Western blot assay (ACSL4/GPX4) and assay kits (Fe2+/ROS/MDA/GSH). The association between ferroptosis and lncRNA OTUD6B-AS1-inhibited radioresistance was testified using ferroptosis inhibitor. The subcellular localization of lncRNA OTUD6B-AS1 was tested by the nuclear/cytoplasmic fractionation assay, with RNA immunoprecipitation assay to validate gene interactions. Rescue experiments were conducted to analyze the role of TRIM16 in CRC radioresistance. Results: LncRNA OTUD6B-AS1 and TRIM16 were poorly expressed (P < 0.01) in CRC tissues and cells and further decreased (P < 0.01) in radioresistant CRC cells. OTUD6B-AS1 overexpression decreased cell survival (P < 0.01), increased γ-H2AX levels (P < 0.01), and elevated ferroptosis and oxidative stress (P < 0.01) after X-ray radiation. Ferroptosis inhibitor attenuated radioresistance (P < 0.01) caused by lncRNA OTUD6B-AS1 overexpression. LncRNA OTUD6B-AS1 stabilized TRIM16 mRNA via binding to HuR. TRIM16 knockdown reduced ferroptosis and increased radioresistance (P < 0.05). Conclusion: OTUD6B-AS1 overexpression stabilized TRIM16 via binding to HuR and increased GPX4-mediated ferroptosis, thus attenuating CRC radioresistance. Our study provided a new rationale for the treatment of CRC. [ABSTRACT FROM AUTHOR]

Abstract Objective Breast cancer is the leading cause of death among women in many countries. Numerous factors serve as oncogenes or tumor suppressors in breast cancer. The large family of Tripartite-motif (TRIM) proteins with ~ 80 members has drawn attention for their role in cancer. TRIM3 and TRIM16 have shown suppressive activity in different cancers. This study aimed to evaluate the expression of TRIM3 and TRIM16 in cancerous and normal breast samples and to investigate their association with different clinical and pathological parameters. Results qRT-PCR was utilized to determine the gene expression of TRIM3 and TRIM16. The expression of TRIM3 and TRIM16 genes in tumor samples were significantly reduced to 0.45 and 0.29 fold, respectively. TRIM3 and TRIM16 genes expression were both positively correlated with the invasion of breast cancer. TRIM3 gene expression was associated with tumors’ histological grade. However, no significant association was found between the expression of the genes and tumor size, stage and necrosis. The expression of TRIM3 and TRIM16 are significantly reduced in breast cancer tissues. Besides, the expression of both TRIM3 and TRIM16 genes significantly plummet in lymphatic/vascular and perineural invasive samples. Hence, we suggest a potential tumor suppressor role for TRIM3 and TRIM16 in breast cancer.

Macroautophagy/autophagy is a lysosome-dependent catabolic pathway for the degradation of intracellular proteins and organelles. Autophagy dysfunction is related to many diseases, including lysosomal storage diseases, cancer, neurodegenerative diseases, cardiomyopathy, and chronic metabolic diseases, in which increased reactive oxygen species (ROS) levels are also observed. ROS can randomly oxidize proteins, lipids, and DNA, causing oxidative stress and damage. Cells have developed various antioxidant pathways to reduce excessive ROS and maintain redox homeostasis. Treatment targeting only one aspect of diseases with autophagy dysfunction and oxidative stress shows very limited effects. Herein, identifying the bridging factors that can regulate both autophagy and antioxidant pathways is beneficial for dual-target therapies. This review intends to provide insights into the current identified bridging factors that connect autophagy and Nrf2 antioxidant pathway, as well as their tight interconnection with each other. These factors could be potential dual-purpose targets for the treatment of diseases implicated in both autophagy dysfunction and oxidative stress.

Purpose: Gastric cancer (GC) has been identified worldwide as one of the most common cancer types with a high mortality rate. LncRNA SDMGC has been recognized as an oncogene with regulatory effects on its target gene, TRIM16, which is believed to play a tumor-suppressing role in various cancers. Both these genes are involved in GC development, tumorigenesis, invasion, and metastasis. The current study is aimed to investigate the association of SDMGC and TRIM16 with GC susceptibility and GC patients' clinicopathological characteristics. Methods: A total of 100 GC tissues and their corresponding adjacent non-tumor tissues were sampled. Total RNA was then isolated to measure SDMGC and TRIM16 expression levels using quantitative reverse transcriptase (qRT)-PCR. Statistical analyses including the Mann–Whitney U test and correlation tests were carried out using R v4.5. GraphPad Prism was also used to plot the receiver operating curve (ROC). Results: The results demonstrated the significant overexpression of lncRNAs SDMGC and downregulation of TRIM16 in GC tissues as compared to their corresponding marginal normal tissue samples (P = 0.005 and P = 0.009, respectively). No association with clinicopathological variables was observed for either SDMGC or TRIM16. Moreover, the results demonstrated a small positive correlation between SDMGC and TRIM16. Evaluation of the diagnostic value of SDMGC and TRIM16 showed poor biomarker potency for these genes. Conclusion: In conclusion, the results indicated an increase in the expression of SDMGC and a decline in the expression pattern of TRIM16 among the Iranian population. The results indicated a key tumor-accelerative function of SDMGC and a pivotal tumor-suppressing role of TRIM16 in GC patients. [ABSTRACT FROM AUTHOR]

Oxidative stress plays a vital role in viral replication. Tripartite motif containing 16 (TRIM16) is involved in diverse cellular processes. However, the role of TRIM16 in oxidative stress induced by infection of the highly pathogenic H5N1 avian influenza virus (HPAIV) is unclear. We found that under conditions of H5N1 HPAIV infection, reactive oxygen species (ROS) levels in A549 cells peaked at 24 h post infection (hpi), and antioxidant genes' expression levels were down-regulated. Overexpression of TRIM16 in A549 cells resulted in a decrease in the titter of H5N1 HPAIV and led to significant up-regulation of the antioxidant genes' expression levels, which indicates that TRIM16 positively regulates the sequestosome 1/Kelch-like associated enoyl-CoA hydratase 1 protein/nuclear factor erythrocyte 2-derived 2-like 2 (SQSTM1/NRF2/KEAP1) pathway. Under basal conditions, TRIM16 led to a modification of NRF2 through an increase in K63-linked poly-ubiquitination of NRF2. Collectively, our findings provide new insight into understanding TRIM16′s role in anti-oxidative stress in H5N1 HPAIV infected A549 cells. [ABSTRACT FROM AUTHOR]

Myocardial infarction is still a leading cause of morbidity and mortality worldwide, but its pathogenesis has not been fully understood. In the study, we attempted to explore the effects of E3 ligase tripartite motif 16 (TRIM16) on myocardial ischemia-reperfusion (MI/R) injury in vivo and in vitro , and the underlying mechanisms. We identified that TRIM16 was indeed a potent regulator during MI/R progression in murine models and surprisingly showed a negative correlation with the concentrations of cardiac pro-inflammatory cytokines. Adenoviral vectors encoding GFP or TRIM16 (Ad-TRIM16) were subjected to mice through direct injection into the left ventricular (LV). We found that Ad-TRIM16 significantly reduced the infarct size, and improved the cardiac function and structure compared with the Ad-GFP mice after MI/R operation. More studies indicated that TRIM16 over-expression strongly meliorated nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and associated inflammatory response in hearts of MI/R-induced mice, which were validated in hypoxia/reoxygenation (H/R)-exposed primary cardiomyocytes in vitro. In particular, MI/R operation led to cardiac pyroptosis by increasing the cleavage of Caspase-1 and Gasdermin D (GSDMD), while being considerably abrogated upon TRIM16 over-expression. Mechanistically, TRIM16 interacted with NLRP3 and promoted the K48-linked polyubiquitination of NLRP3, ultimately promoted its degradation. Together, we identified TRIM16 as a novel E3 ubiquitin ligase for NLRP3, which played an essential role in modulating its expression, and subsequently influenced inflammatory response and pyroptosis in MI/R murine model, confirming that TRIM16 may be a potential therapeutic target for myocardial infarction. [Display omitted] • TRIM16 expression is restrained during MI/R process. • TRIM16 ameliorates 24 h MI/R-induced heart injury. • TRIM16 mitigates inflammation and pyroptosis in MI/R mice. • TRIM16 interacts with NLRP3, and TRIM16 induces K48-linked NLRP3 degradation in cardiomyocytes. [ABSTRACT FROM AUTHOR]

Objective: Breast cancer is the leading cause of death among women in many countries. Numerous factors serve as oncogenes or tumor suppressors in breast cancer. The large family of Tripartite-motif (TRIM) proteins with ~ 80 members has drawn attention for their role in cancer. TRIM3 and TRIM16 have shown suppressive activity in different cancers. This study aimed to evaluate the expression of TRIM3 and TRIM16 in cancerous and normal breast samples and to investigate their association with different clinical and pathological parameters. Results: qRT-PCR was utilized to determine the gene expression of TRIM3 and TRIM16. The expression of TRIM3 and TRIM16 genes in tumor samples were significantly reduced to 0.45 and 0.29 fold, respectively. TRIM3 and TRIM16 genes expression were both positively correlated with the invasion of breast cancer. TRIM3 gene expression was associated with tumors' histological grade. However, no significant association was found between the expression of the genes and tumor size, stage and necrosis. The expression of TRIM3 and TRIM16 are significantly reduced in breast cancer tissues. Besides, the expression of both TRIM3 and TRIM16 genes significantly plummet in lymphatic/vascular and perineural invasive samples. Hence, we suggest a potential tumor suppressor role for TRIM3 and TRIM16 in breast cancer. [ABSTRACT FROM AUTHOR]

Senile osteoporosis (SOP), characterized by significant bone loss, poses a substantial threat to elderly skeletal health, with oxidative stress playing a crucial role in its pathogenesis. Although Tripartite Motif 16 (TRIM16) has been identified as a promoter of antioxidant response and osteogenic differentiation, its regulatory role in SOP remains incompletely understood. This study aims to elucidate the underlying mechanism of TRIM16 in mitigating D-galactose (D-gal)-induced senescent osteoblasts. Initially, we observed diminished bone mineral density (BMD) and impaired bone microstructure in naturally aging (24 months) and D-gal-induced (18 months) aged mice through Dual-energy X-ray absorptiometry (DEXA), micro-CT, hematoxylin and eosin staining, and Masson staining. Immunohistochemistry analysis revealed downregulation of TRIM16 and osteogenic differentiation markers (Collagen-1, Runx-2, osteopontin) in femur samples of aged mice. Furthermore, in D-gal-induced senescent MC3T3-E1 osteoblasts, we observed the suppression of osteogenic differentiation and maturity, along with cytoskeleton impairment via Alkaline phosphatase (ALP), Alizarin Red S, and Rhodamine-phalloidin staining. The protein expression of TRIM16, osteogenic differentiation markers, and antioxidant indicators (Nrf-2, HO-1, SOD1) decreased, while the production of reactive oxygen species (ROS) significantly increased. Knockdown and overexpression of TRIM16 using lentivirus in osteoblasts revealed that the downregulation of TRIM16 inhibited osteogenic differentiation and induced oxidative stress. Notably, TRIM16 overexpression partially attenuated D-gal-induced inhibition of osteogenic differentiation and increased oxidative stress. These findings suggest TRIM16 may mitigate impaired osteogenic differentiation and antioxidant response in D-gal-induced senescent osteoblasts, suggesting its potential as a therapeutic target for SOP. [ABSTRACT FROM AUTHOR]

Tripartite motif-containing (TRIM) proteins are conserved throughout the metazoan kingdom, and the TRIM subset finTRIM is highly diversified in fish. We isolated TRIM16 cDNA, a member of the finTRIM family, from the olive flounder Paralichthys olivaceus (PoTRIM16). PoTRIM16 contained a 1,725-bp coding sequence encoding a 574-amino acid polypeptide, which in turn contained a really interesting new gene (RING) finger domain, B-box-type zinc finger (B-BOX), nuclease SbcCD subunit C (SbcC), structural maintenance of chromosome (SMC prok B), and stonustoxin (SNTX) subunit alpha (SPRY-PRY-SNTX). Multiple alignment of related sequences revealed that PoTRIM16 showed 86.63–97.40% identity with fish orthologues, and a phylogenetic tree was constructed of vertebrates. PoTRIM16 mRNA was detected in all tissues examined; levels were highest in the eye and ovary. PoTRIM16 mRNA expression was investigated during early development. Under VHSV infection, PoTRIM16 mRNA was downregulated in the liver of P. olivaceus. This is the first study to characterize fish-specific finTRIM in P. olivaceus , which may play a role in the immune response against virus infection. • We characterized a novel finTRIM in Paralichthys olivaceus (PoTRIM16). • PoTRIM16 cDNAs encode polypeptides with the RBCC, SMC-M and SPRY-PRY-SNTX motif. • PoTRIM16 showed 86.6–97.4% identity with fish orthologues. • PoTRIM16 mRNA was downregulated in the liver under VHSV infection. [ABSTRACT FROM AUTHOR]

Recently, it was covered that cellular retinoic acid‐binding protein 2 (CRABP2) is upregulated in ovarian cancer and participates in tumor progression, however, the specific mechanism remains to be explored. The pcDNA‐CRABP2 or si‐CRABP2 was transfected into SKOV3 and OVCAR3 ovarian cancer cells, respectively, and we observed that overexpression of CRABP2 inhibited cell apoptosis, promoted cell invasion and expression of epithelial mesenchymal transition (EMT) marker proteins, and transfection of si‐CRABP2 had the opposite effect. Furthermore, we predicted that EZH2 interacted with CRABP2, and overexpression of CRABP2 promoted EZH2 expression, knockdown of CRABP2 inhibited EZH2 expression, and co‐immunoprecipitation assay confirmed their binding relationship. The SKOV3 and OVCAR3 cells were then incubated with pcDNA‐CRABP2 alone together with si‐EZH2, and we found that si‐EZH2 reversed the effect of pcDNA‐CRABP2 on promotion of EZH2 expression, cell invasion and EMT maker protein levels. Next, we found that EZH2 could bind to DNMT1, and overexpression of EZH2 inhibited TRIM16 expression and knockdown of EZH2 promoted TRIM16 expression. Moreover, the promoter of TRIM16 contains the CpG island, and ChIP assay observed enriched DNMT1 on the promoter of TRIM16, and overexpression of EZH2 increased the promoter methylation level of TRIM16 and knockdown of EZH2 suppressed the methylation. The SKOV3 cells were incubated with si‐EZH2 alone or combined with si‐TRIM16, and we found that si‐TRIM16 reversed the effect of si‐EZH2. In vivo studies showed that knockdown of CRABP2 inhibited tumor volume and weight, suppressed the expression of EZH2 and EMT related proteins vimentin and snail, and increased the expression of TRIM16 and E‐cadherin. [ABSTRACT FROM AUTHOR]

Bone regeneration is the ultimate goal of periodontal therapies, in which osteogenic differentiation of human periodontal ligament stem cells plays a critical role. The tripartite motif (TRIM)16, an E3 ubiquitin ligase, is downregulated in periodontal tissues of patients with periodontitis, while the role of TRIM16 in the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) is largely unknown. Firstly, we found that TRIM16 was increased throughout the osteogenic media induced differentiation of hPDLSCs. Then overexpression plasmids and specific short-hairpin RNAs (shRNAs) were constructed to manipulate the expression of target molecules. TRIM16 significantly promoted alkaline phosphatase activity, mineralized nodule formation, and positively regulated the expression of osteo-specific markers RUNX2, COL1A1 and OCN except the mRNA of RUNX2. Mechanistically, TRIM16 serves as a pivotal factor that stabilizes RUNX2 protein levels by decreasing CHIP-mediated K48-linked ubiquitination degradation of the RUNX2 protein. This study identified a novel mechanism of TRIM16 in regulating stability of the RUNX2 protein, which promoted the osteogenic differentiation of hPDLSCs. TRIM16 may be a potential target of stem cell based-bone regeneration for periodontal therapies.

Тhe protein TRIM16 is involved in key intracellular processes, such as proliferation, cell differentiation and programmed death, including intrinsic and extrinsic apoptosis, autophagy-dependent cell death and immunogenic cell death. The TRIM16 protein acts the proteins TPD43, Gli-1, RARβ, Snail components and MAPK signaling pathway, cadherins, caspases and is also associated with the regulation of the immune system via direct and indirect mechanisms. The influence of TRIM16 protein on the pathogenesis of hormone-dependent tumors is well-known. Further study of the TRIM16 role in the development and progression of malignant neoplasms will form the basis for the development of new methods for predicting the course of the malignant process.

The cellular stresses, genetic mutations, and environmental factors can critically affect the protein quality control checkpoints resulting in protein misfolding. Molecular chaperones play a crucial role in maintaining the healthy proteome by refolding the misfolded proteins into the native functional conformations. However, if they fail to refold the misfolded proteins into the native state, they are targeted by proteolytic systems for degradation. If the misfolded protein numbers increase more than what a cell can resolve, they get converted protein aggregates/inclusion bodies. The inclusion bodies are less cytotoxic than misfolded proteins. The enhanced production of misfolded proteins and protein aggregates are linked to several diseases collectively termed proteinopathies, which includes several neurodegenerative disorders. The understanding of molecular mechanisms that regulate the turnover of protein aggregates will pave path for therapeutic interventions of proteinopathies. In a recent report, we showed that a tripartite motif (TRIM) family protein, TRIM16 streamlines the process of protein aggregates turnover by regulating the NRF2-p62 axis and autophagy.

Sex hormones, regulating normal physiological processes of most tissues and organs, are considered to be one of the key factors in the development of hormone-dependent cancer and formation of the hormone-resistant tumor phenotype. Recently, the importance of the system for control of hormone receptors expression mediated by nuclear peptides became evident. This system is involved in the regulation of normal physiological processes, in the pathogenesis of many diseases as well as oncogenesis. In the review, we discuss the relationships of the two regulatory peptides – Brn-3α, TRIM16 with hormone receptors. The transcription factor Brn-3α is able to affect the transcription activity of androgen and estrogen receptors. It is observed the participation of TRIM16 protein in the pathogenesis of hormone-dependent tumors due to its ''anti-estrogenic effect''. Additionally, they are involved in the key intracellular processes, such as proliferation, cell differentiation, and programmed death - apoptosis. Thus, Brn-3α and TRIM16 are associated with cancer development and progression. By understanding these alterations, we can identify potential markers and novel biochemical therapeutic targets. It makes clear the association between classical hormone-dependent tumors and less sensitive ones with the modification in the level of hormone receptors.

Purpose: The tripartite motif (TRIM)16 acts as a tumour suppressor in both squamous cell carcinoma (SCC) and melanoma. TRIM16 is known to be secreted by keratinocytes, but no studies have been reported yet to assess the relationship between TRIM16 keratinocyte expression and melanoma development. Methods: To study the role of TRIM16 in skin cancer development, we developed a keratinocyte TRIM16-specific knockout mouse model, and used the classical two-stage skin carcinogenesis challenge method, to assess the loss of keratinocyte TRIM16 on both papilloma, SCC and melanoma development in the skin after topical carcinogen treatment. Results: Heterozygous, but not homozygous, TRIM16 knockout mice exhibited an accelerated development of skin papillomas and melanomas, larger melanoma lesions and an increased potential for lymph node metastasis. Conclusion: This study provides the first evidence that keratinocyte loss of the putative melanoma tumour suppressor protein, TRIM16, enhances melanomagenesis. Our data also suggest that TRIM16 expression in keratinocytes is involved in cross talk between keratinocytes and melanocytes, and has a role in melanoma tumorigenesis. [ABSTRACT FROM AUTHOR]

[Display omitted] The clinic application of doxorubicin (DOX) is severely limited by its severe cardiotoxicity. Tripartite motif-containing protein 16 (TRIM16) has E3 ubiquitin ligase activity and is upregulated in cardiomyocytes under pathological stress, yet its role in DOX-induced cardiotoxicity remains elusive. This study aims to investigate the role and mechanism of TRIM16 in DOX cardiotoxicity. Following TRIM16 overexpression in hearts with AAV9-TRIM16, mice were intravenously administered DOX at a dose of 4 mg/kg/week for 4 weeks to assess the impact of TRIM16 on doxorubicin-induced cardiotoxicity. Transfection of OE-TRIM16 plasmids and siRNA-TRIM16 was performed in neonatal rat cardiomyocytes (NRCMs). Our results revealed that DOX challenge elicited a significant upregulation of TRIM16 proteins in cardiomyocytes. TRIM16 overexpression efficiently ameliorated cardiac function while suppressing inflammation, ROS generation, apoptosis and fibrosis provoked by DOX in the myocardium. TRIM16 knockdown exacerbated these alterations caused by DOX in NRCMs. Mechanistically, OE-TRIM16 augmented the ubiquitination and degradation of p-TAK1, thereby arresting JNK and p38MAPK activation evoked by DOX in cardiomyocytes. Furthermore, DOX enhanced the interaction between p-TAK1 and YAP1 proteins, resulting in a reduction in YAP and Nrf2 proteins in cardiomyocytes. OE-TRIM16 elevated YAP levels and facilitated its nuclear translocation, thereby promoting Nrf2 expression and mitigating oxidative stress and inflammation. This effect was nullified by siTRIM16 or TAK1 inhibitor Takinib. Collectively, the current study elaborates that upregulating TRIM16 mitigates DOX-induced cardiotoxicity through anti-inflammation and anti-oxidative stress by modulating TAK1-mediated p38 and JNK as well as YAP/Nrf2 pathways, and targeting TRIM16 may provide a novel strategy to treat DOX-induced cardiotoxicity. [ABSTRACT FROM AUTHOR]

Protein misfolding and protein aggregation are linked to several diseases commonly called as proteinopathies, which include cancer. Understanding the mechanisms of proteostasis could provide newer strategies to combat proteinopathies. We have recently demonstrated a new mechanism where we found that TRIM16 (tripartite motif-containing protein 16) utilizing NRF2-p62 axis and autophagy streamlines the safe disposal of misfolded proteins to maintain protein homeostasis.

We studied reception of sex steroid hormones in the tissues of thyroid papillary cancer and benign tumor. Enhanced expression of AR and ERβ mRNA reflected malignant tumor growth. Nuclear factors Brn-3α and TRIM16 modulating expression of steroid hormones play an important role in the development of thyroid tumors. It was found that the level of TRIM16 mRNA is associated with the expression of ERβ, which seems to be mediated by its antiestrogen effect. [ABSTRACT FROM AUTHOR]

Abstract The autophagy pathway known also as macroautophagy (herein referred to as autophagy) is characterized by the formation of double-membrane organelles that capture cytosolic material. Based on pathway termination alternatives, autophagy has been divided into degradative and secretory. During degradative autophagy, autophagosomes typically fuse with lysosomes upon which the sequestered material is degraded. During secretory autophagy, instead of degradation the sequestered cargo is subjected to active secretion or passive release. In this review, we focus on the mechanisms of secretion/passive release of the potent pro-inflammatory cytokine IL-1β, as a prototypical leaderless cytosolic protein cargo studied in the context of secretory autophagy. [ABSTRACT FROM AUTHOR]

Abstract: Sequestration of protein aggregates in inclusion bodies and their subsequent degradation prevents proteostasis imbalance, cytotoxicity, and proteinopathies. The underlying molecular mechanisms controlling the turnover of protein aggregates are mostly uncharacterized. Herein, we show that a TRIM family protein, TRIM16, governs the process of stress‐induced biogenesis and degradation of protein aggregates. TRIM16 facilitates protein aggregate formation by positively regulating the p62‐NRF2 axis. We show that TRIM16 is an integral part of the p62‐KEAP1‐NRF2 complex and utilizes multiple mechanisms for stabilizing NRF2. Under oxidative and proteotoxic stress conditions, TRIM16 activates ubiquitin pathway genes and p62 via NRF2, leading to ubiquitination of misfolded proteins and formation of protein aggregates. We further show that TRIM16 acts as a scaffold protein and, by interacting with p62, ULK1, ATG16L1, and LC3B, facilitates autophagic degradation of protein aggregates. Thus, TRIM16 streamlines the process of stress‐induced aggregate clearance and protects cells against oxidative/proteotoxic stress‐induced toxicity in vitro and in vivo. Taken together, this work identifies a new mechanism of protein aggregate turnover, which could be relevant in protein aggregation‐associated diseases such as neurodegeneration. [ABSTRACT FROM AUTHOR]

Personalized treatment targeting the epidermal growth factor receptor (EGFR) may be a promising new treatment of non-small cell lung cancer (NSCLC). Gefitinib, a tyrosine kinase inhibitor, is the first drug for NSCLC, which unfortunately easily leads to drug resistance. Our study aimed to explore the functional role of microRNA (miR)-135 in the sensitivity to gefitinib of NSCLC cells. Expression of miR-135 in normal cells and NSCLC cells was assessed, followed by the effects of abnormally expressed miR-135 on cell viability, migration, invasion, apoptosis, sensitivity to gefitinib, and the expression levels of adhesion molecules and programmed death ligand 1 (PD-L1) in H1650 and H1975 cells. Next, the possible target gene of miR-135 was screened and verified. Finally, the potential involvement of the JAK/STAT signaling pathway was investigated. Expression of miR-135 was upregulated in NSCLC cells, and miR-135 silencing repressed cell viability, migration, and invasion, but increased cell apoptosis and sensitivity to gefitinib. E-cadherin and β-catenin were significantly upregulated, but PD-L1 was downregulated by the silencing of miR-135. Subsequently, tripartite-motif (TRIM) 16 was screened and verified to be a target gene of miR-135, and miR-135 suppression was shown to function through upregulation of TRIM16 expression. Phosphorylated levels of the key kinases in the JAK/STAT pathway were reduced by silencing miR-135 by targeting TRIM16. In conclusion, miR-135 acted as a tumor promoter, and its suppression could improve sensitivity to gefitinib by targeting TRIM16 and inhibition of the JAK/STAT pathway. [ABSTRACT FROM AUTHOR]

Abbreviations: Aβ: amyloid β; AD: Alzheimer disease; AMPK: 5' adenosine monophosphate-activated protein kinase; CTSB: cathepsin B; CTSD: cathepsin D; DM: diabetes mellitus; ESCRT: endosomal sorting complex required for transport; FBXO27: F-box protein 27; iPSC-NDs: induced pluripotent stem cell-derived neuronal differentiated cells; LAMP1: lysosomal-associated membrane protein 1; LMP: lysosomal membrane permeabilization; LRSAM1: leucine rich repeat and sterile alpha motif containing 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTORC1: mechanistic target of rapamycin kinase complex 1; p-MAPT/tau: phosphorylated microtubule associated protein tau; ROS: reactive oxygen species; STZ: streptozotocin; TFE3: transcription factor E3; TFEB: transcription factor EB; TRIM16: tripartite motif containing 16; UBE2QL1: ubiquitin conjugating enzyme E2 Q family like 1; VCP: valosin containing protein.

Tripartite Motif-containing protein 16 (TRIM16) is a member of a large family of tripartite motif (TRIM) proteins, that has been implicated in the pathogenesis of multiple cancers. However, the mechanism by which TRIM16 acts as a tumour suppressor is currently unknown. We used the versatile yeast two-hybrid assay on a cDNA library from human testes, which has relative high TRIM16 expression, to identify potential TRIM16-binding proteins. We identified transactive response DNA-binding protein 43 (TDP43) as a novel TRIM16 binding protein. Co-immunoprecipitation assay demonstrated that TDP43 bound TRIM16 in neuroblastoma and breast cancer cells. Enforced over-expression of TRIM16 increased the protein half-life of TDP43, through the inhibition of the proteosomal degradation pathway. High levels of TRIM16 and TDP43 are associated with good prognosis in both human neuroblastoma and breast cancer tissues. Importantly, we found TDP43 expression was required for TRIM16-induced inhibition of neuroblastoma and breast cancer cell growth and the repressive effect of TRIM16 on cell cycle regulatory proteins, E2F1 and pRb. Taken together, our data suggest that TRIM16 and TDP43 are both good prognosis indicators; also we showed that TRIM16 inhibits cancer cell viability by a novel mechanism involving interaction and stabilisation of TDP43 with consequent effects on E2F1 and pRb proteins. [ABSTRACT FROM AUTHOR]

The present study was to examine the effect of Tripartite motif 16 (TRIM16) on epithelial–mesenchymal transition (EMT) and metastasis in non-small cell lung cancer (NSCLC) cells, and its clinical significance in NSCLC. The correlation of TRIM16 expression and clinical features of NSCLC was analyzed in paraffin-embedded archived normal lung tissues and NSCLC tissues by immunohistochemical analysis. The effect of TRIM16 on EMT and metastasis was examined both in vitro and in vivo. The expression of TRIM16 was markedly decreased in NSCLC and correlated with tumor metastasis. Upregulation of TRIM16 significantly inhibited EMT and metastasis of NSCLC cells. In contrast, silencing TRIM16 expression significantly promoted the EMT and metastasis of NSCLC cells both in vitro and in vivo. Moreover, we demonstrated that downregulation of TRIM16 activated the sonic hedgehog pathway, and that inhibition of the sonic hedgehog pathway by cyclopamine abrogated the effect of TRIM16-downregulation induced EMT and metastasis on NSCLC cells. Our results suggest that TRIM16 is a potential pharmacologic target for the treatment of NSCLC and promotion TRIM16 expression might represent a novel strategy to NSCLC metastasis. [ABSTRACT FROM AUTHOR]

TRIM16 exhibits tumour suppressor functions by interacting with cytoplasmic vimentin and nuclear E2F1 proteins in neuroblastoma and squamous cell carcinoma cells, reducing cell migration and replication. Reduced TRIM16 expression in a range of human primary malignant tissues correlates with increased malignant potential. TRIM16 also induces apoptosis in breast and lung cancer cells, by unknown mechanisms. Here we show that overexpression of TRIM16 induces apoptosis in human breast cancer (MCF7) and neuroblastoma (BE(2)-C) cells, but not in non-malignant HEK293 cells. TRIM16 increased procaspase-2 protein levels in MCF7 and induced caspase-2 activity in both MCF7 and BE(2)-C cells. We show that TRIM16 and caspase-2 proteins directly interact in both MCF7 and BE(2)-C cells and co-localise in MCF7 cells. Most importantly, the induction of caspase-2 activity is required for TRIM16 to initiate apoptosis. Our data suggest a novel mechanism by which TRIM16 can promote apoptosis by directly modulating caspase-2 activity. [ABSTRACT FROM AUTHOR]

Enhanced aerobic glycolysis contributes to the metastasis of pancreatic cancer metastasis, but the mechanism underlying the abnormal activation of glycolysis has not been fully elucidated. The E3 ligase tripartite motif 16 (TRIM16) is involved in the progression of many cancers. However, the role of and molecular mechanism by which TRIM16 acts in pancreatic cancer are unclear. In this study, we report that TRIM16 was significantly upregulated in pancreatic cancer tissues, and high expression of TRIM16 was associated with poor prognosis in patients with pancreatic cancer. Multivariate analyses showed that TRIM16 was an independent predictor of poor outcomes among patients with pancreatic cancer. In addition, in vitro and in vivo evidence showed that TRIM16 promoted pancreatic cancer cell metastasis by enhancing glycolysis. Furthermore, we revealed that TRIM16 controlled glycolysis and pancreatic cancer cell's metastasis by regulating sine oculis homeobox 1 (SIX1), an important transcription factor that promotes glycolysis. TRIM16 upregulated SIX1 by inhibiting its ubiquitination and degradation, which was mediated by NF-κB-inducing kinase (NIK), an upstream regulator of SIX1. Hence, NIK inhibitor can suppress SIX1 expression, glycolysis and metastasis in TRIM16-overexpressing pancreatic cancer cells. Mechanistic investigations demonstrated that TRIM16 competed with NIK's E3 ligase, TNF receptor-associated factor 3 (TRAF3), at the ISIIAQA sequence motif of NIK, and then stabilized NIK protein. Our study identified the TRIM16-NIK-SIX1 axis as a critical regulatory pathway in aerobic glycolysis and pancreatic cancer metastasis, indicating that this axis can be an excellent therapeutic target for curing pancreatic cancer., Competing Interests: None., (AJCR Copyright © 2022.)

Tripartite motif containing 16 (TRIM16) is a member of the tripartite motif protein family and functions as a potential tumor suppressor in several cancers. However, the specific function and clinical significance of TRIM16 in colorectal cancer (CRC) remains unclear. In this study, we observed that low TRIM16 expression was detected frequently in primary colorectal cancer (CRC) tissues and was closely associated with a better prognosis. Functional studies demonstrate that TRIM16 overexpression notably inhibits the metastasis abilities of CRC in vivo and in vitro. Mechanistically, our results demonstrated that TRIM16 directly bound and ubiquitinated Snail family transcriptional repressor 1 (Snail), an important transcriptional factor of the epithelial-mesenchymal transition (EMT) process suppressing the EMT in CRC. Additionally, our data revealed that the inhibition effect of TRIM16 on cancer metastasis was dependent on Snail degradation. Collectively, our study is the first to report that TRIM16 plays a crucial anti-tumor role in CRC tumorigenesis. We also provided novel evidence that TRIM16 might act as a prognostic and therapeutic target to assess and inhibit CRC progression. • TRIM16 does significantly inhibit CRC cell migration and metastasis. • TRIM16 negatively regulates CRC cells EMT. • TRIM16 directly interacts with Snail. • TRIM16 promotes degradation of Snail via ubiquition proteasome pathway. [ABSTRACT FROM AUTHOR]

In recent years, the problem of cancer resistance has become more and more prominent, seriously affecting treatment efficiency. Circular RNAs (circRNAs) play an important role in cell progression and cancer mechanisms. However, there is a lack of systematic studies on its function in non-small cell lung cancer (NSCLC) resistance. CircPTK2, microRNA-942 (miR-942), and Tripartite motif 16 (TRIM16) levels were detected by Real-time quantitative reverse transcriptase PCR (qRT-PCR). Extracellular acidification rate (ECAR), glucose consumption, and lactate production were assessed using the Seahorse XF96 Glycolysis Analyzer, glucose, and lactate assay kits, respectively. The protein expression was measured with the western bolt Transwell assay was used to determine migration and invasion of transfected cells. (4-5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and flow cytometry were applied to carry out cell proliferation and apoptosis, respectively. The relationship among circPTK2, miR-942, and TRIM16 were determined by using the dual-luciferase reporter assay and RIP assay. circPTK2 (hsa&#95;circ&#95;0008305) and TRIM16 were low expressed, while miR-942 was significantly highly expressed in NSCLC tissues and cell lines. Moreover, overexpression of circPTK2 remarkably inhibited cell growth, metastasis, and glycolysis in A549/CDDP and H1299/CDDP cells. Promotion of miR-942 or inhibition of TRIM16 could reverse the effects of high circPTK2 expression on cell growth, metastasis, and glycolysis in A549/CDDP and H1299/CDDP cells. CircPTK2 overexpression inhibited the growth of A549/CDDP cells in vivo . Furthermore, circPTK2 weakened CDDP resistance of NSCLC through modulating miR-942/TRIM16 axis, providing a novel sight for the treatment of NSCLC and improving the understanding of the CDDP resistance mechanism of NSCLC.

Nonalcoholic steatohepatitis (NASH)-related hepatocellular carcinoma and liver disorders have become the leading causes for the need of liver transplantation in developed countries. Lipotoxicity plays a central role in NASH progression by causing endoplasmic reticulum stress and disrupting protein homeostasis. To identify key molecules that mitigate the detrimental consequences of lipotoxicity, we performed integrative multiomics analysis and identified the E3 ligase tripartite motif 16 (TRIM16) as a candidate molecule. In particular, we found that lipid accumulation and inflammation in a mouse NASH model is mitigated by TRIM16 overexpression but aggravated by its depletion. Multiomics analysis showed that TRIM16 suppressed NASH progression by attenuating the activation of the mitogen-activated protein kinase (MAPK) signaling pathway; specifically, by preferentially interacting with phospho-TAK1 to promote its degradation. Together, these results identify TRIM16 as a promising therapeutic target for the treatment of NASH. [Display omitted] • TRIM16 is transcriptionally activated by EGR2 in response to lipotoxicity • TRIM16 ameliorates lipid accumulation and inflammation during NASH progression • TRIM16 inhibits the JNK/p38 pathway by catalyzing ubiquitin-mediated degradation of pTAK1 • AAV8-mediated TRIM16 overexpression attenuates NASH progression in HFHC-fed mice Wang et al. report that TRIM16 ameliorates lipid accumulation and inflammation during NASH progression by facilitating the ubiquitination-dependent degradation of phospho-TAK1. Further, they show that overexpressing TRIM16 in a mouse model of NASH ameliorates pathology. [ABSTRACT FROM AUTHOR]

Periodontitis is a chronic inflammatory disease that result in severe loss of supporting structures and substantial tooth loss. Oxidative stress is tightly involved in the progression of periodontitis. Tripartite Motif 16 (TRIM16) has been identified as a novel regulatory protein in response to oxidative and proteotoxic stresses. The present study aimed to investigate the role of TRIM16 in human periodontal ligament stem cells (hPDLSCs) under oxidative stress. First, we found that the expression of TRIM16 decreased after exposure to H 2 O 2. Then TRIM16 overexpression alleviated H 2 O 2 -induced oxidative stress by enhancing antioxidant capacity and reducing the amount of intracellular reactive oxygen species (ROS) and reactive nitrogen species (RNS). TRIM16 increased cell viability, inhibited cell apoptosis and the depolarization of the mitochondrial membrane potential in hPDLSCs. Furthermore, TRIM16 attenuated H 2 O 2 -induced suppression of osteogenic differentiation. Mechanistically, TRIM16 promoted the activation of protein kinase C (PKC)-interacting cousin of thioredoxin (PICOT), p-Akt and Nrf2, while knockdown of PICOT reversed TRIM16-mediated ROS resistance and decreased the expression of p-Akt and Nrf2. In conclusion, TRIM16 alleviated oxidative damage in hPDLSCs via the activation of PICOT/Akt/Nrf2 pathway, suggesting that TRIM16 could be a promising target to develop effective therapies for periodontitis. • TRIM16 protects hPDLSCs against oxidative stress. • TRIM16 attenuates H2O2-induced suppression of osteogenic differentiation. • PICOT is involved in TRIM16 mediated cytoprotective effects in hPDLSCs. [ABSTRACT FROM AUTHOR]

Tripartite motif 16 (TRIM16) has emerged as a novel oxidative stress-responsive protein that confers cytoprotective effects by reinforcing the cellular antioxidant system. However, whether TRIM16 is involved in regulating oxidative stress during cerebral ischemia/reperfusion injury remains unclear. In the present study, we aimed to explore the potential function and molecular mechanism of TRIM16 in regulating oxidative stress in neurons induced by oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro. Here, we found that OGD/R exposure resulted in a significant induction of TRIM16 expression in neurons. Depletion of TRIM16 by siRNA-mediated gene knockdown markedly upregulated the sensitivity of neurons to OGD/R-induced apoptosis and reactive oxygen species (ROS) generation. Notably, upregulation of TRIM16 expression significantly alleviated OGD/R-induced apoptosis and ROS generation in neurons. Moreover, TRIM16 overexpression markedly increased nuclear factor erythroid 2-related factor 2 (Nrf2) expression and enhanced Nrf2/antioxidant response element (ARE) activation associated with downregulation of kelch-like ECH-associated protein 1 (Keap1) expression. Restoration of Keap1 significantly reversed the TRIM16-mediated promotion effect on Nrf2/ARE activation. In addition, knockdown of Nrf2 also markedly abrogated the TRIM16-conferred neuroprotective effect in OGD/R-exposed neurons. Taken together, our results of our study demonstrate that induction of TRIM16 confers a cytoprotective effect in OGD/R-exposed neurons through enhancement of Nrf2/ARE antioxidant signaling via downregulation of Keap1. These findings suggest that TRIM16 may play a critical role in cerebral ischemia/reperfusion injury and serve as a promising target for neuroprotection. Image 1 • TRIM16 is induced by OGD/R injury in neurons. • TRIM16 alleviates OGD/R-induced neuronal injury. • TRIM16 enhances Nrf2 activation via Keap1 inhibition. • Nrf2 inhibition reverses TRIM16-mediated neuroprotective effect. [ABSTRACT FROM AUTHOR]

Background and Aim: Tripartite Motif Containing 16 (TRIM16) is a member of the TRIM protein family which is known to play a suppressor role in development of numerous tumor types. However, a positive correlation between TRIM16 expression and gastric cancer (GC) progress has created a controversial situation that need to be fully delineated.  The aim of this study was to assess the expression level of TRIM16 mRNA and its relationship with β-catenin, CyclinD, and BCL2 expression in Iranian GC patients and to investigate its possible association with patients' overall survival.  Materials and Methods: The expression level of TRIM16 of fresh primary tumor and adjacent normal tissues in 40 GC patients was evaluated by real-time quantitative PCR method. Moreover, patients were subdivided into high or low expression subgroups based on the TRIM16 expression levels. The relationship between TRIM16 expression level, β-catenin, Cyclin D, BCL2, some clinicopathological data and prognosis of GC patients was also analyzed., Results: qPCR analysis showed a lower level of TRIM16 in GC tissues (fold change=0.351) in comparison to their matched adjacent noncancerous tissues (p <0.001). Contrary to this, the expression levels of β-catenin, Cyclin D, and BCL2 genes were up-regulated in cancerous samples. This may explain the tumor suppressive function of TRIM16 in GC; as reduction in TRIM16 expression leads to the accumulation of mRNAs from β-catenin, Cyclin D, and BCL2 genes and eventually cancer progression. We did not observe any significant correlation between TRIM16 expression and patients' overall survival. Univariate Cox regression analysis indicated that anemia, weight loss, bleeding, stomach ache, and smoking are statistically associated with overall survival; while, multivariate analysis did not support any correlation.  Conclusions: In sum, this study suggests a tumor suppressive role for TRIM16 in gastric cancer and proposes it as a potential candidate for GC prognosis., .

The osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs) is critical for bone homeostasis. Here, we investigated the regulation of Galectin-3 and tripartite motif protein 16 (TRIM16) on osteogenic differentiation of hBMSCs through autophagy. Quantitative PCR (qPCR) and western blot were performed to determine the expression of osteogenic markers, autophagic markers, Galectin-3 and TRIM16. Short-hairpin RNAs (shRNAs) and overexpression plasmids were used to manipulate the expression of Galectin-3 , TRIM16 and Unc-51 like autophagy activating kinase 1 (ULK1). Alkaline phosphatase (ALP) activity was measured by ALP staining assay. Calcium deposition in differentiated hBMSCs was assessed by Alizarin Red S staining. LC3 puncta formation was monitored by immunofluorescence staining. The interaction between indicated proteins was confirmed by co-immunoprecipitation (Co-IP) assay. Either Galectin-3 or TRIM16 knockdown led to impaired ALP activity, reduced calcium deposition, down-regulation of pro-osteogenic markers as well as restrained autophagy in osteogenic-induced hBMSCs. However, overexpression of Galectin-3 or TRIM16 promoted osteogenic differentiation of hBMSCs, which was then compromised by autophagy inhibition. Co-IP experiment demonstrated that TRIM16 associated with Galectin-3 through ULK1. Meanwhile, osteogenic induction enhanced the association between TRIM16 and ULK1 or coiled-coil myosin-like BCL2-interacting protein (Beclin1), and TRIM16 increased the stability of ULK1 and Beclin1. Moreover, either TRIM16 or ULK1 knockdown dampened the pro-osteogenic effect of Galectin-3, which elucidated that Galectin-3 mediated osteogenic differentiation was at least partly dependent on TRIM16 and ULK1. In summary, the present study revealed Galectin-3 and TRIM16 co-regulated osteogenic differentiation of hBMSCs at least partly via enhancing autophagy, which might provide a promising approach for osteoporosis treatment in future. • Either Galectin-3 or TRIM16 knockdown leads to the suppression of osteogenic differentiation of hBMSC via impaired autophagy. • Autophagy inhibition comprised the osteogenic differentiation of hBMSC mediated by Galectin-3 or TRIM16. • Galectin-3 interacts with TRIM16, ULK1 and Beclin1. • Regulation of osteogenic differentiation of hBMSC by Galectin-3 is at least partly dependent on TRIM16 and ULK1. [ABSTRACT FROM AUTHOR]

Ras-association (RA) domain family number 6 (RASSF6) is a member of the Ras-association domain protein family. It is epigenetically inactive and negatively regulates the malignant progression of some tumors. However, its precise role in esophageal squamous cell carcinoma (ESCC) has not been reported. In this study, we performed immunohistochemistry (IHC) assay. The results show that RASSF6 is upregulated in ESCC and that the elevated expression level of RASSF6 is associated with lymph node metastasis and poor survival of ESCC patients. Consistent with the clinical observations, the upregulation of RASSF6 greatly promotes ESCC cell proliferation, migration and invasion as well as the cell cycle transition to G1/S phase in vitro. According to models in vivo, the downregulation of RASSF6 considerably inhibits ESCC tumor growth and lung metastasis. Mechanistically, RASSF6 negatively regulates the tumor suppressor tripartite-motif-containing protein 16 (TRIM16) by promoting its ubiquitination-dependent degradation and eventually activates pathways associated with the cell cycle and epithelial-mesenchymal transition (EMT). Together, these results indicate that the RASSF6-TRIM16 axis is a key effector in ESCC progression and that RASSF6 serves as a potential target for the treatment of ESCC., (Copyright © 2019 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Ltd. All rights reserved.)

Protein misfolding and protein aggregation are linked to several diseases commonly called as proteinopathies, which include cancer. Understanding the mechanisms of proteostasis could provide newer strategies to combat proteinopathies. We have recently demonstrated a new mechanism where we found that TRIM16 (tripartite motif-containing protein 16) utilizing NRF2-p62 axis and autophagy streamlines the safe disposal of misfolded proteins to maintain protein homeostasis. [ABSTRACT FROM AUTHOR]