SP140 inhibitor suppressing TRIM22 expression regulates glioma progress through PI3K/AKT signaling pathway

BACKGROUND

SP gene family, consisting of SP100, SP110, SP140, and SP140L, has been implicated in the initiation and advancement of numerous malignancies. Nevertheless, their clinical significance in glioma remains incompletely understood.

METHOD

Expression levels and prognostic significance of SP family members were evaluated in the TCGA and CGGA datasets. Multifactorial analysis was used to identify SP gene family members that can independently impact the prognosis of glioma patients. A SP140-based predictive risk model/nomogram was developed in TCGA dataset and validated in CGGA dataset. The model's performance was evaluated through receiver operating characteristic (ROC) curves, calibration plots, and decision curve analyses. Phenotypic associations of SP140 and TRIM22 were examined through CancerSEA and TIMER. The effect of SP140 inhibitor in glioma progress and TRIM22/PI3K/AKT signaling pathway was confirmed in U251/U87 glioma cells.

RESULTS

The SP family members exhibited elevated expression in gliomas and were negatively correlated with prognosis. SP140 emerged as an independent prognostic factor, and a SP140-based nomogram/predictive risk model demonstrated high accuracy. SP140 inhibitor, GSK761, lead to the suppression of TRIM22 expression and the PI3K/AKT signaling pathway. GSK761 also restrain glioma proliferation, migration, and invasion. Furthermore, SP140 and TRIM22 coexpressed in glioma cells with high level of vascular proliferation, TRIM22 is closely associated with the immune cell infiltration.

CONCLUSION

SP140-based nomogram proved to be a practical tool for predicting the survival of glioma patients. SP140 inhibitor could suppress glioma progress via TRIM22/PI3K/AKT signaling pathway.

Disassembly of the TRIM56-ATR complex promotes cytoDNA/cGAS/STING axis-dependent intervertebral disc inflammatory degeneration

As the leading cause of disability worldwide, low back pain (LBP) is recognized as a pivotal socioeconomic challenge to the aging population and is largely attributed to intervertebral disc degeneration (IVDD). Elastic nucleus pulposus (NP) tissue is essential for the maintenance of IVD structural and functional integrity. The accumulation of senescent NP cells with an inflammatory hypersecretory phenotype due to aging and other damaging factors is a distinctive hallmark of IVDD initiation and progression. In this study, we reveal a mechanism of IVDD progression in which aberrant genomic DNA damage promoted NP cell inflammatory senescence via activation of the cyclic GMP-AMP synthase/stimulator of IFN genes (cGAS/STING) axis but not of absent in melanoma 2 (AIM2) inflammasome assembly. Ataxia-telangiectasia-mutated and Rad3-related protein (ATR) deficiency destroyed genomic integrity and led to cytosolic mislocalization of genomic DNA, which acted as a powerful driver of cGAS/STING axis-dependent inflammatory phenotype acquisition during NP cell senescence. Mechanistically, disassembly of the ATR-tripartite motif-containing 56 (ATR-TRIM56) complex with the enzymatic liberation of ubiquitin-specific peptidase 5 (USP5) and TRIM25 drove changes in ATR ubiquitination, with ATR switching from K63- to K48-linked modification, c thereby promoting ubiquitin-proteasome-dependent dynamic instability of ATR protein during NP cell senescence progression. Importantly, an engineered extracellular vesicle-based strategy for delivering ATR-overexpressing plasmid cargo efficiently diminished DNA damage-associated NP cell senescence and substantially mitigated IVDD progression, indicating promising targets and effective approaches to ameliorate the chronic pain and disabling effects of IVDD.

TRIM25 inhibition attenuates inflammation, senescence, and oxidative stress in microvascular endothelial cells induced by hyperglycemia

PURPOSES

This work aimed to assess the possible role of TRIM25 in regulating hyperglycemia-induced inflammation, senescence, and oxidative stress in retinal microvascular endothelial cells, all of which exert critical roles in the pathological process of diabetic retinopathy.

METHODS

The effects of TRIM25 were investigated using streptozotocin-induced diabetic mice, human primary retinal microvascular endothelial cells cultured in high glucose, and adenoviruses for TRIM25 knockdown and overexpression. TRIM25 expression was evaluated by western blot and immunofluorescence staining. Inflammatory cytokines were detected by western blot and quantitative real-time PCR. Cellular senescence level was assessed by detecting senescent marker p21 and senescence-associated-β-galactosidase activity. The oxidative stress state was accessed by detecting reactive oxygen species and mitochondrial superoxide dismutase.

RESULTS

TRIM25 expression is elevated in the endothelial cells of the retinal fibrovascular membrane from diabetic patients compared with that of the macular epiretinal membrane from non-diabetic patients. Moreover, we have also observed a significant increase in TRIM25 expression in diabetic mouse retina and retinal microvascular endothelial cells under hyperglycemia. TRIM25 knockdown suppressed hyperglycemia-induced inflammation, senescence, and oxidative stress in human primary retinal microvascular endothelial cells while TRIM25 overexpression further aggregates those injuries. Further investigation revealed that TRIM25 promoted the inflammatory responses mediated by the TNF-α/NF-κB pathway and TRIM25 knockdown improved cellular senescence by increasing SIRT3. However, TRIM25 knockdown alleviated the oxidative stress independent of both SIRT3 and mitochondrial biogenesis.

CONCLUSION

Our study proposed TRIM25 as a potential therapeutic target for the protection of microvascular function during the progression of diabetic retinopathy.

ZnO nanoparticles impair autophagic flux and cell viability through the TRIM16-NRF2-p62 pathway in inflammatory keratinocytes

PURPOSE

Zinc oxide nanoparticles (ZnO NPs) are widely used in sunscreen, cosmetics, and topical drugs. Most previous studies have confirmed the safety of ZnO NPs applied to normal skin; however, little is known about the safety and potential toxicity of ZnO NPs applied to inflamed skin. This study aimed to evaluate the exposure risk of ZnO NPs in the treatment of inflammatory skin diseases.

METHODS

Normal human and tumor necrosis factor-α (TNF-α)-induced inflammatory keratinocytes were incubated with ZnO NPs to assess their toxic effects on cell viability and autophagy signaling pathway. Tandem mass tag (TMT)-based proteomics analysis was used to identify differentially expressed proteins following incubation of inflammatory keratinocytes with ZnO NPs. Protein expression was assessed by Western blot, and double fluorescent labeling and siRNA-knockdown further elucidated the role of the TRIM16-NRF2-p62 pathway in mediating the effects of ZnO NP.

RESULTS

In TNF-α-induced inflammatory keratinocytes, ZnO NPs activated cytoprotective autophagy and mediated p62-related autophagic flux block, thereby reducing the viability of inflammatory keratinocytes. Additionally, TRIM16-NRF2 was essential in ZnO NP-mediated autophagy flux block and cell viability reduction in inflammatory keratinocytes. Inhibition of the TRIM16-NRF2 pathway reduced p62 levels, alleviated autophagy flux blockade, and slightly restored the viability of inflammatory keratinocytes.

CONCLUSION

ZnO NPs activated protective cell autophagy. Blockade of autophagy flux mediated by the TRIM16-NRF2-p62 pathway led to decreased cell viability. This study provided a deeper understanding of the toxicity mechanism of ZnO NPs in inflammatory keratinocytes.

TRIM6 silencing for inhibiting growth and angiogenesis of gliomas by regulating VEGFA

Gliomas are the highest prevalent primary central nervous system (CNS) cancers with poor overall survival rate. There is an urgent need to conduct more research into molecular therapies targeting critical elements of gliomas. This study herein targeted to assess the impact of tripartite motif protein 6 (TRIM6) on gliomas. Using public databases, we found the increased TRIM6 expression in tissues of glioma which was linked with worst overall survival. Silencing TRIM6 promoted glioma cell proliferation, migration and angiogenesis, suggesting the promoting effects of TRIM6 on gliomas. Knockdown of TRIM6 expression downregulated the expression levels of Forkhead box M1 (FOXM1) and vascular endothelial growth factor A (VEGFA) in glioma cells. Afterwards, impact of TRIM6 on VEGFA expression was regulated by FOXM1. VEGFA overexpression reversed the decreased abilities of glioma cell proliferation, migration and angiogenesis caused by silencing TRIM6. Furthermore, we also found that TRIM6 promoted the growth of gliomas in the xenograft mouse model. In summary, the expression of TRIM6 was increased which was related to poor prognosis of glioma patients. TRIM6 promoted glioma cell proliferation, migration and angiogenesis through the FOXM1-VEGFA pathway. Therefore, TRIM6 carries capacity to be explored as a novel therapeutic target in clinical.

TRIM17-mediated ubiquitination and degradation of RBM38 promotes cisplatin resistance in non-small cell lung cancer

Cisplatin (CDDP)-based chemotherapy is commonly used to treat advanced non-small cell lung cancer (NSCLC). However, the efficacy is limited by the development of drug resistance. Tripartite motif (TRIM) proteins typically have E3 ubiquitin ligase activities and modulate protein stability. In the present study, we screened for chemosensitivity-regulating TRIM proteins using CDDP-resistant NSCLC cell lines. We show that TRIM17 is upregulated in CDDP-resistant NSCLC cells and tumors compared to CDDP-sensitive counterparts. NSCLC patients with high TRIM17 expression in tumors have shorter progression-free survival than those with low TRIM17 expression after CDDP chemotherapy. Knockdown of TRIM17 increases the sensitivity of NSCLC cells to CDDP both in vitro and in vivo. In contrast, overexpression of TRIM17 promotes CDDP resistance in NSCLC cells. TRIM17-mediated CDDP resistance is associated with attenuation of reactive oxygen species (ROS) production and DNA damage. Mechanistically, TRIM17 interacts with RBM38 and promotes K48-linked ubiquitination and degradation of RBM38. TRIM17-induced CDDP resistance is remarkably reversed by RBM38. Additionally, RBM38 enhances CDDP-induced production of ROS. In conclusion, TRIM17 upregulation drives CDDP resistance in NSCLC largely by promoting RBM38 ubiquitination and degradation. Targeting TRIM17 may represent a promising strategy for improving CDDP-based chemotherapy in NSCLC.

MG53 Does Not Manifest the Development of Diabetes in db/db Mice

MG53 is a member of the TRIM protein family that is predominantly expressed in striated muscles and participates in cell membrane repair. Controversy exists regarding MG53's role in insulin signaling and manifestation of diabetes. We generated db/db mice with either whole-body ablation or sustained elevation of MG53 in the bloodstream in order to evaluate the physiological function of MG53 in diabetes. To quantify the amount of MG53 protein in circulation, we developed a monoclonal antibody against MG53 with high specificity. Western blot using this antibody revealed lower or no change of serum MG53 levels in db/db mice or patients with diabetes compared with control subjects. Neither whole-body ablation of MG53 nor sustained elevation of MG53 in circulation altered insulin signaling and glucose handling in db/db mice. Instead, mice with ablation of MG53 were more susceptible to streptozotocin-induced dysfunctional handling of glucose compared with the wild-type littermates. Alkaline-induced corneal injury demonstrated delayed healing in db/db mice, which was restored by topical administration of recombinant human (rh)MG53. Daily intravenous administration of rhMG53 in rats at concentrations up to 10 mg/kg did not produce adverse effects on glucose handling. These findings challenge the hypothetical function of MG53 as a causative factor for the development of diabetes. Our data suggest that rhMG53 is a potentially safe and effective biologic to treat diabetic oculopathy in rodents.

Enhancing membrane repair increases regeneration in a sciatic injury model

Various injuries to the neural tissues can cause irreversible damage to multiple functions of the nervous system ranging from motor control to cognitive function. The limited treatment options available for patients have led to extensive interest in studying the mechanisms of neuronal regeneration and recovery from injury. Since many neurons are terminally differentiated, by increasing cell survival following injury it may be possible to minimize the impact of these injuries and provide translational potential for treatment of neuronal diseases. While several cell types are known to survive injury through plasma membrane repair mechanisms, there has been little investigation of membrane repair in neurons and even fewer efforts to target membrane repair as a therapy in neurons. Studies from our laboratory group and others demonstrated that mitsugumin 53 (MG53), a muscle-enriched tripartite motif (TRIM) family protein also known as TRIM72, is an essential component of the cell membrane repair machinery in skeletal muscle. Interestingly, recombinant human MG53 (rhMG53) can be applied exogenously to increase membrane repair capacity both in vitro and in vivo. Increasing the membrane repair capacity of neurons could potentially minimize the death of these cells and affect the progression of various neuronal diseases. In this study we assess the therapeutic potential of rhMG53 to increase membrane repair in cultured neurons and in an in vivo mouse model of neurotrauma. We found that a robust repair response exists in various neuronal cells and that rhMG53 can increase neuronal membrane repair both in vitro and in vivo. These findings provide direct evidence of conserved membrane repair responses in neurons and that these repair mechanisms can be targeted as a potential therapeutic approach for neuronal injury.