Protective role of MG53 against ischemia/reperfusion injury on multiple organs: A narrative review

Doxorubicin-induced apoptosis is exacerbated by MG53 and associated with altered Akt signaling in H9c2 cells

Chemotherapy drugs such as doxorubicin (DOX) are frequently used to treat cancer, but its negative impact on the heart reduces its effectiveness. Among the members of the TRIM protein family, mitsugumin (MG)53, also known as TRIM72, is unique. It is primarily present in the plasma membrane of cardiac and skeletal muscle cells and has been demonstrated to participate in mending cellular membrane damage while protecting against heart ischemia/reperfusion injury. This research investigated the role of MG53 in DOX-induced apoptosis using H9c2 cells, a cardiomyoblast cell line, as an experimental model. Our findings indicate that DOX treatment statistically significantly upregulates MG53 expression in H9c2 cells. Furthermore, MG53 overexpression exacerbated DOX-induced apoptosis, as confirmed by elevated levels of cleaved-caspase3 and BAX and reduced expression of Bcl-2. Flow cytometry analysis supported the elevated cell death rate in cells overexpressing MG53. Additionally, MG53 overexpression was associated with reduced phosphorylation levels of protein kinase B (AKT), as indicated by the decreased phosphorylation levels of AKT. Conversely, silencing MG53 through siRNA increased the phosphorylation levels of AKT. These results imply that MG53 exacerbates DOX-induced apoptosis, related to reduced AKT phosphorylation. Our investigation sheds light on the detrimental effects of MG53 in DOX-induced myocardial damage and underscores its potential as a therapeutic target for alleviating DOX treatment-related heart toxicity. SIGNIFICANCE STATEMENT: This study reveals that mitsugumin 53 exacerbates doxorubicin-induced apoptosis in H9c2 cells, associated with altered protein kinase B signaling. Targeting mitsugumin 53 may offer a novel therapeutic approach to mitigate doxorubicin-associated cardiotoxicity.

Traditional Chinese medicine as a viable option for managing vascular cognitive impairment: A ray of hope

Vascular cognitive impairment (VCI) is a prevalent cognitive disorder resulting from cerebrovascular disease and encompasses a spectrum of cognitive deficits, ranging from mild impairment to vascular dementia (VD). VCI is responsible for a minimum of 20% to 40% of all cases of dementia, with its prevalence ranking second only to Alzheimer's disease on a global scale. The pathogenesis of VCI is complex and includes a lack of cholinergic nerve cells, inflammation, oxidative stress, alterations in the blood-brain barrier, and cell apoptosis. Current guideline-recommended drugs have unsatisfactory therapeutic effects. However, traditional Chinese medicine (TCM) has long been associated with treating dementia, and numerous studies regarding treating dementia with TCM have been conducted. The etiology and pathogenesis of VaD are linked to deficiencies in the spleen and kidney, as well as phlegm turbidity. Treatment involves benefiting the spleen and kidney, improving blood circulation, removing blood stasis, and dispelling phlegm. Moreover, TCM presents benefits such as few adverse effects, low cost, long-term use suitability, and preventive effects. This review outlines the pathogenesis of VCI in both modern medicine and TCM, examines traditional prescriptions and single-agent ingredients with their pharmacological effects, emphasizes TCM's unique features, and explores its multi-targeted approach to treating VCI.

YTHDF2 mediates the protective effects of MG53 on myocardial infarction injury via recognizing the m6A modification of MG53

INTRODUCTION

High levels of MG53 may attenuate the damage from myocardial infarction (MI). Furthermore, N6-methyl-adenosine (m6A) methylation is a mode of RNA modification that influences mRNA functions. Whether m6A modification on MG53 exerts a protective role on myocardial injury remains largely unknown.

MATERIALS AND METHODS

We established hypoxia/reoxygenation (H/R) H9c2 cell and myocardial ischemia reperfusion (I/R) rat models. MG53 expression was detected using RT-qPCR, and its m6A levels were measured using Me-RIP. The relationship between MG53 and YTHDF2 was evaluated using RNA immunoprecipitation, FISH and immunofluorescence assay, and luciferase reporter assay. MI area of rats was determined using TTC staining. Cell apoptosis was assessed by flow cytometry and TUNEL assay.

RESULTS

The m6A levels of MG53 were increased in H/R-induced H9c2 cells and the myocardium of I/R rats. Moreover, knockdown of YTHDF2 recognized the m6A modification of MG53 and enhanced MG53 stability. Overexpression of MG53 inhibited apoptosis of H/R-treated H9c2 cells, which was reversed by YTHDF2, while downregulation of MG53 m6A methylation caused by METTL3 knockdown further abrogated the effect induced by YTHDF2. Additionally, MG53 attenuated MI and apoptosis in I/R rats, which were rescued by YTHDF2.

CONCLUSION

YTHDF2 hinders the protective effect of MG53 on MI by recognizing the m6A modification of MG53.

TRIM44 alleviates renal ischemia-reperfusion injury by inhibiting pyroptosis through the NLRP3 pathway

BACKGROUND

Renal ischemia-reperfusion injury (IRI) is a prevailing manifestation of acute kidney injury (AKI) with limited treatment options. TRIM44 has emerged as a possible target for treatment due to its regulatory function in inflammatory pathways.

METHODS

In vivo and in vitro models were employed to ascertain the TRIM44 impact on renal IRI. In vivo, we induced IRI in mice and assessed histological changes, oxidative stress markers, and pyroptosis-related proteins. In vitro, we subjected renal cells to hypoxia/reoxygenation (H/R) and manipulated TRIM44 expression to evaluate its effects on cell viability and pyroptosis.

RESULTS

IRI significantly increased inflammation, oxidative stress, and pyroptosis in both animal and cell models, evidenced by elevated cleaved caspase-1, GSDMD-N, and IL-1β/-18 levels. IRI conditions experienced a mitigated TRIM44 expression. Overexpression of TRIM44 in renal cells reduced pyroptosis, as shown by decreased levels of pyroptosis-related proteins and inflammatory cytokines and improved cell viability. Mechanistically, TRIM44 inhibited the NLRP3 inflammasome, as evidenced with reduced NLRP3 and cleaved caspase-1 levels upon TRIM44 overexpression and NLRP3 inhibition. In vivo, intravenous administration of TRIM44-expressing adenovirus post-IRI ameliorated renal damage, as reported with mitigated serum creatinine and blood urea nitrogen levels.

CONCLUSION

TRIM44 protects against renal IRI by inhibiting pyroptosis via the NLRP3 pathway, suggesting its potential to be targeted therapeutically for treating AKI.

Tripartite motif (TRIM) proteins roles in the regulation of immune system responses: Focus on autoimmune diseases

The tripartite motif (TRIM) proteins are well-studied as essential modulators of many processes, including the modulation of several pathways linked to immunological reactions. Most TRIM family members can polyubiquitinate the targeted proteins by acting as E3 ubiquitin ligases. According to current research, TRIMs play a critical role in innate immune response via modifying transcription factors, pattern recognition receptors (PRRs), and key adaptor proteins within innate immunity. It is becoming clearer that TRIMs play important roles in adaptive immune response, especially in the stimulation and promotion of T cells. We highlight the E3 ubiquitin ligase functions of TRIMs in the PRRs axis linked to autoimmune disorders. By focusing on TRIM family members, we also clarify the new approaches to regulating immunological reactions to alleviate autoimmunity.

Trim72 is a major host factor protecting against lethal Candida albicans infection

Candida albicans is the most common aetiologic pathogen of fungal infections associated with high mortality in immunocompromised patients. There is an urgent need to develop new antifungal therapies owing to the poor efficacy and resistance of current antifungals. Here, we report that Trim72 positively regulates antifungal immunity during lethal fungal infection. Trim72 levels are significantly increased after Candida albicans infection. In vivo, Trim72 knockout significantly increases mortality, organ fungal burden and kidney damage in mice after lethal Candida albicans infection. Whereas recombinant Trim72 protein treatment protects mice against invasive candidiasis. Mechanistically, Trim72 facilitates macrophage infiltration and CCL2 production, which mediates Trim72-elicited protection against lethal Candida albicans infection. Furthermore, Trim72 may enhance macrophage migration and CCL2 production via NF-κB and ERK1/2 signaling. Inhibition of NF-κB and ERK1/2 signaling abrogates Trim72-mediated protection against lethal Candida albicans infection. Therefore, these data imply that Trim72 may be developed as a host-directed therapy for treating severe systemic candidiasis.

TRIM72 restricts lyssavirus infection by inducing K48-linked ubiquitination and proteasome degradation of the matrix protein

The tripartite motif (TRIM) protein family is the largest subfamily of E3 ubiquitin ligases, playing a crucial role in the antiviral process. In this study, we found that TRIM72, a member of the TRIM protein family, was increased in neuronal cells and mouse brains following rabies lyssavirus (RABV) infection. Over-expression of TRIM72 significantly reduced the viral titer of RABV in neuronal cells and mitigated the pathogenicity of RABV in mice. Furthermore, we found that TRIM72 over-expression effectively prevents the assembly and/or release of RABV. In terms of the mechanism, TRIM72 promotes the K48-linked ubiquitination of RABV Matrix protein (M), leading to the degradation of M through the proteasome pathway. TRIM72 directly interacts with M and the interaction sites were identified and confirmed through TRIM72-M interaction model construction and mutation analysis. Further investigation revealed that the degradation of M induced by TRIM72 was attributed to TRIM72's promotion of ubiquitination at site K195 in M. Importantly, the K195 site was found to be partially conserved among lyssavirus's M proteins, and TRIM72 over-expression induced the degradation of these lyssavirus M proteins. In summary, our study has uncovered a TRIM family protein, TRIM72, that can restrict lyssavirus replication by degrading M, and we have identified a novel ubiquitination site (K195) in lyssavirus M.

Sodium salicylate ameliorates exercise-induced muscle damage in mice by inhibiting NF-kB signaling

BACKGROUND

Eccentric muscle contraction can cause muscle damage, which reduces the efficiency of exercise. Previous evidence suggested that Sodium salicylate (SS) could improve the repair of aged muscle. This study intends to investigate whether SS can impact skeletal muscle damage caused by eccentric exercise.

METHODS

Eccentric treadmill exercise was performed to induce muscle damage in mice. Plasma levels of muscle damage markers were estimated. RT-qPCR was employed for detecting mRNA levels of proinflammatory mediators in murine gastrocnemius muscle. Immunofluorescence staining of laminin/DAPI was utilized for quantifying centrally nucleated myofibers in the gastrocnemius muscle. Western blotting was implemented to examine protein levels of mitsugumin 53 (MG53), matrix metalloproteinase (MMP)-2/9, and NF-κB signaling-related markers.

RESULTS

SS administration reduced muscle damage marker production in the plasma and decreased the levels of proinflammatory mediators, MG53 and MMP-2/9 in mice after exercise. SS alleviated the severity of muscle damage in the gastrocnemius of mice after eccentric exercise. SS blocked NF-κB signaling pathway in the gastrocnemius muscle.

CONCLUSION

SS administration ameliorates skeletal muscle damage caused by eccentric exercise in the mouse model.

MG53 alleviates airway inflammatory responses by regulating nuclear factor-κB pathway in asthmatic mice

BACKGROUND

Asthma is a common lung disease with increasing incidence and prevalence globally, thereby imposing a substantial global health and economic burden. Recently, studies have shown that Mitsugumin 53 (MG53) exhibits multiple biological functions and plays a protective role in a variety of diseases. However, the role of MG53 in asthma remained unknown; hence, in the present study we aimed to explore the functioning of MG53 in asthma.

METHODS

Using ovalbumin and aluminum hydroxide adjuvant, an OVA-induced asthmatic animal model was constructed and administered with MG53. After establishing mice model, inflammatory cell counts and the levels of type 2 inflammatory cytokines were examined and histological staining of lung tissues were performed. The levels of key factors associated with the nuclear factor-κB (NF-κB) pathway were detected.

RESULTS

Asthmatic mice displayed a remarkable accumulation of white blood cells, neutrophils, macrophages, lymphocytes, and eosinophils in bronchoalveolar lavage fluid, compared to control mice. MG53 treatment lowered the number of these inflammatory cells in asthmatic mice. The level of type 2 cytokines in asthmatic mice was higher than that in control mice, and was lessened by MG53 intervention. In asthmatic mice, airway resistance was elevated, which was reduced by MG53 treatment. In addition, inflammatory cell infiltration and mucus secretion were aggravated in the lung tissues of asthmatic mice, and both were attenuated by MG53 intervention. The levels of phosphorylated p65 and phosphorylated inhibitor of nuclear factor kappa-B kinase were elevated in asthmatic mice, but were downregulated by MG53 supplement.

CONCLUSION

The aggravated airway inflammation was observed in asthmatic mice; however, MG53 treatment suppressed airway inflammation by targeting the NF-κB pathway.