TRIM8: a double-edged sword in glioblastoma with the power to heal or hurt

Silencing TRIM8 alleviates allergic asthma and suppressing Th2 differentiation through inhibiting NF-κB/NLRP3 signaling pathway

BACKGROUND AND AIM

Allergic asthma is a primary type of asthma and characterized by T helper 2 (Th2) cells -mediated inflammation. Tripartite motif containing 8 (TRIM8) protein is involved in immunoreaction and inflammatory response in many diseases. However, its role in allergic asthma remains unclear. Medical databank showed that TRIM8 was increased in lung of ovalbumin (OVA)-challenged mice. This study aimed to elucidate the effects of TRIM8 on allergic asthma and Th2 development.

METHODS

Asthma were induced by OVA challenge in mice, and the adenovirus vector loaded with TRIM8 knockdown sequence was delivered into asthma mice by nasal inhalation. The percentage of Th2 cells in lung was assessed by flow cytometric analysis, and the contents of Th2 cytokines (interleukin (IL)-4, IL-5 and IL-13) in bronchoalveolar lavage fluid (BALF) were assessed with ELISA. In vitro Th2 induction was performed in CD4+ cells from mouse spleen, the expression of Th2 molecules (IL-4, IL-5 and GATA binding protein 3 (GATA3)) were measured by real-time PCR. In addition, the nuclear factor-kappa B (NF-κB)/nucleotide-binding oligomerization domain, leucine rich repeat and pyrin domain containing 3 (NLRP3) signaling was determined.

RESULTS

TRIM8 was highly expressed in the lung tissues of asthmatic mice and Th2-induced CD4+ cells. OVA challenge-induced Th2 development and Th2 cytokine secretion were restrained by silencing of TRIM8 in vivo. Similarly, the Th2 differentiation in vitro was also suppressed by TRIM8 knockdown. TRIM8 inhibited the NF-κB/NLRP3 activity by blocking transforming growth factor-beta-activated kinase 1 (TAK1), and the effects of TRIM8 were abrogated by overexpression of NLRP3.

CONCLUSIONS

Silencing TRIM8 relieved the asthmatic injury in mice and excessive Th2 development via inhibiting the NF-κB/NLRP3 pathway. It is indicated that TRIM8 may contribute to the airway inflammation in allergic asthma via activating the NF-κB/NLRP3 signaling pathway. The current study provided a novel potential target for allergic asthma treatment.

Single-cell RNA sequencing in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is one of the most common chronic inflammatory rheumatic diseases in children, with onset before age 16 and lasting for more than 6 weeks. JIA is a highly heterogeneous condition with various consequences for health and quality of life. For some JIA patients, early detection and intervention remain challenging. As a result, further investigation of the complex and unknown mechanisms underlying JIA is required. Advances in technology now allow us to describe the biological heterogeneity and function of individual cell populations in JIA. Through this review, we hope to provide novel ideas and potential targets for the diagnosis and treatment of JIA by summarizing the current findings of single-cell RNA sequencing studies and understanding how the major cell subsets drive JIA pathogenesis.

Multipronged regulation of autophagy and apoptosis: emerging role of TRIM proteins

TRIM proteins are characterized by their conserved N-terminal RING, B-box, and coiled-coil domains. These proteins are efficient regulators of autophagy, apoptosis, and innate immune responses and confer immunity against viruses and bacteria. TRIMs function as receptors or scaffold proteins that target substrates for autophagy-mediated degradation. Most TRIMs interact with the BECN1-ULK1 complex to form TRIMosomes, thereby efficiently targeting substrates to autophagosomes. They regulate the functions of ATG proteins through physical interactions or ubiquitination. TRIMs affect the lipidation of MAP1LC3B1 to form MAP1LC3B2, which is a prerequisite for phagophore and autophagosome formation. In addition, they regulate MTOR kinase and TFEB, thereby regulating the expression of ATG genes. TRIM proteins are efficient regulators of apoptosis and are crucial for regulating cell proliferation and tumor formation. Many TRIM proteins regulate intrinsic and extrinsic apoptosis via the cell surface receptors TGFBR2, TNFRSF1A, and FAS. Mitochondria modulate the anti- and proapoptotic functions of BCL2, BAX, BAK1, and CYCS. These proteins use a multipronged approach to regulate the intrinsic and extrinsic apoptotic pathways, culminating in coordinated activation or inhibition of the initiator and executor CASPs. Furthermore, TRIMs can have a dual effect in determining cell fate and are therefore crucial for cellular homeostasis. In this review, we discuss mechanistic insights into the role of TRIM proteins in regulating autophagy and apoptosis, which can be used to better understand cellular physiology. These findings can be used to develop therapeutic interventions to prevent or treat multiple genetic and infectious diseases.

Unveiling the Dichotomy of Urinary Proteins: Diagnostic Insights into Breast and Prostate Cancer and Their Roles

This review covers the diagnostic potential of urinary biomarkers, shedding light on their linkage to cancer progression. Urinary biomarkers offer non-invasive avenues for detecting cancers, potentially bypassing the invasiveness of biopsies. The investigation focuses primarily on breast and prostate cancers due to their prevalence among women and men, respectively. The intricate interplay of urinary proteins is explored, revealing a landscape where proteins exhibit context-dependent behaviors. The review highlights the potential impact of physical activity on urinary proteins, suggesting its influence on tumorigenic behaviors. Exercise-conditioned urine may emerge as a potential diagnostic biomarker source. Furthermore, treatment effects, notably after lumpectomy and prostatectomy, induce shifts in the urinary proteome, indicating therapeutic impacts rather than activating oncogenic signaling. The review suggests further investigations into the double-sided, context-dependent nature of urinary proteins, the potential role of post-translational modifications (PTM), and the integration of non-protein markers like mRNA and metabolites. It also discusses a linkage of urinary proteomes with secretomes from induced tumor-suppressing cells (iTSCs). Despite challenges like cancer heterogeneity and sample variability due to age, diet, and comorbidities, harnessing urinary proteins and proteoforms may hold promise for advancing our understanding of cancer progressions, as well as the diagnostic and therapeutic role of urinary proteins.

Mutual regulation between TRIM21 and TRIM8 via K48-linked ubiquitination

Tripartite motif (TRIM)-containing proteins, one of the largest subfamilies of the RING type E3 ubiquitin ligases, control important biological processes such as cell apoptosis, autophagy, signal transduction, innate immunity and tumorigenesis. So far, the mutual regulation between TRIM family members has rarely been reported. Here, we found for the first time that there was a direct mutual regulation between TRIM21 and TRIM8 in lung and renal cancer cells, mechanistically by activating their proteasome pathway via Lys48 (K48)- linked ubiquitination. Subsequent studies verified that negatively correlated expressions existed in clinical non-small cell lung cancer (NSCLC) and renal cell carcinoma (RCC) tissues, which were closely related to tumor progression. Our findings highlighted a possible homeostasis between TRIM21 and TRIM8 that might possibly affect cell stemness and was expected to provide a new idea for cancer therapy.

Regulating the regulatory T cells as cell therapies in autoimmunity and cancer

Regulatory T cells (Tregs), possess a pivotal function in the maintenance of immune homeostasis. The dysregulated activity of Tregs has been associated with the onset of autoimmune diseases and cancer. Hence, Tregs are promising targets for interventions aimed at steering the immune response toward the desired path, either by augmenting the immune system to eliminate infected and cancerous cells or by dampening it to curtail the damage to self-tissues in autoimmune disorders. The activation of Tregs has been observed to have a potent immunosuppressive effect against T cells that respond to self-antigens, thus safeguarding our body against autoimmunity. Therefore, promoting Treg cell stability presents a promising strategy for preventing or managing chronic inflammation that results from various autoimmune diseases. On the other hand, Tregs have been found to be overactivated in several forms of cancer, and their role as immune response regulators with immunosuppressive properties poses a significant impediment to the successful implementation of cancer immunotherapy. However, the targeting of Tregs in a systemic manner may lead to the onset of severe inflammation and autoimmune toxicity. It is imperative to develop more selective methods for targeting the function of Tregs in tumors. In this review, our objective is to elucidate the function of Tregs in tumors and autoimmunity while also delving into numerous therapeutic strategies for reprogramming their function. Our focus is on reprogramming Tregs in a highly activated phenotype driven by the activation of key surface receptors and metabolic reprogramming. Furthermore, we examine Treg-based therapies in autoimmunity, with a specific emphasis on Chimeric Antigen Receptor (CAR)-Treg therapy and T-cell receptor (TCR)-Treg therapy. Finally, we discuss key challenges and the future steps in reprogramming Tregs that could lead to the development of novel and effective cancer immunotherapies.