Regulation of mitochondrial fusion and mitophagy by intra-tumoral delivery of membrane-fused mitochondria or Midiv-1 enhances sensitivity to doxorubicin in triple-negative breast cancer

MALSU1-mediated regulation of mitochondrial function governs proliferation and doxorubicin resistance in triple-negative breast cancer cells

Triple-negative breast cancer (TNBC) poses a formidable challenge in oncology due to its aggressive nature and limited treatment options. Although doxorubicin, a widely used chemotherapeutic agent, shows efficacy in TNBC treatment, acquired resistance remains a significant obstacle. Our study explores the role of MALSU1, a regulator of mitochondrial translation, in TNBC and its impact on cell proliferation and doxorubicin resistance. We observed increased MALSU1 expression in TNBC, correlating with poor patient prognosis. MALSU1 knockdown in TNBC cells significantly reduced proliferation, indicating its pivotal role in sustaining cell growth. Mechanistically, MALSU1 depletion resulted in decreased activities of mitochondrial respiratory chain complexes, cellular ATP levels, and mitochondrial respiration. Notably, exogenous addition of normal mitochondria restored proliferation and mitochondrial respiration in MALSU1-depleted TNBC cells. Importantly, MALSU1 knockdown enhanced the sensitivity of doxorubicin-resistant TNBC cells to doxorubicin treatment. Furthermore, pharmacological inhibition of mitochondrial translation using tigecycline and chloramphenicol mimicked the effects of MALSU1 knockdown, suggesting mitochondrial translation as a potential therapeutic target. Taken together, our findings not only elucidate the intricate role of MALSU1 in TNBC biology and doxorubicin resistance but also lay the groundwork for future investigations targeting MALSU1 and/or mitochondrial translation as a promising avenue for developing innovative therapeutic strategies against TNBC.

Mitophagy defect mediates the aging-associated hallmarks in Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is a rare and fatal disease manifested by premature aging and aging-related phenotypes, making it a disease model for aging. The cellular machinery mediating age-associated phenotypes in HGPS remains largely unknown, resulting in limited therapeutic targets for HGPS. In this study, we showed that mitophagy defects impaired mitochondrial function and contributed to cellular markers associated with aging in mesenchymal stem cells derived from HGPS patients (HGPS-MSCs). Mechanistically, we discovered that mitophagy affected the aging-associated phenotypes of HGPS-MSCs by inhibiting the STING-NF-ĸB pathway and the downstream transcription of senescence-associated secretory phenotypes (SASPs). Furthermore, by utilizing UMI-77, an effective mitophagy inducer, we showed that mitophagy induction alleviated aging-associated phenotypes in HGPS and naturally aged mice. Collectively, our results uncovered that mitophagy defects mediated the aging-associated markers in HGPS, highlighted the function of mitochondrial homeostasis in HGPS progression, and suggested mitophagy as an intervention target for HGPS and aging.

Nanodrug Delivery Systems for Myasthenia Gravis: Advances and Perspectives

Myasthenia gravis (MG) is a rare chronic autoimmune disease caused by the production of autoantibodies against the postsynaptic membrane receptors present at the neuromuscular junction. This condition is characterized by fatigue and muscle weakness, including diplopia, ptosis, and systemic impairment. Emerging evidence suggests that in addition to immune dysregulation, the pathogenesis of MG may involve mitochondrial damage and ferroptosis. Mitochondria are the primary site of energy production, and the reactive oxygen species (ROS) generated due to mitochondrial dysfunction can induce ferroptosis. Nanomedicines have been extensively employed to treat various disorders due to their modifiability and good biocompatibility, but their application in MG management has been rather limited. Nevertheless, nanodrug delivery systems that carry immunomodulatory agents, anti-oxidants, or ferroptosis inhibitors could be effective for the treatment of MG. Therefore, this review focuses on various nanoplatforms aimed at attenuating immune dysregulation, restoring mitochondrial function, and inhibiting ferroptosis that could potentially serve as promising agents for targeted MG therapy.

Transcriptome Analysis Reveals the Involvement of Mitophagy and Peroxisome in the Resistance to QoIs in Corynespora cassiicola

Quinone outside inhibitor fungicides (QoIs) are crucial fungicides for controlling plant diseases, but resistance, mainly caused by G143A, has been widely reported with the high and widespread use of QoIs. However, two phenotypes of Corynespora casiicola (RI and RII) with the same G143A showed significantly different resistance to QoIs in our previous study, which did not match the reported mechanisms. Therefore, transcriptome analysis of RI and RII strains after trifloxystrobin treatment was used to explore the new resistance mechanism in this study. The results show that 332 differentially expressed genes (DEGs) were significantly up-regulated and 448 DEGs were significantly down-regulated. The results of GO and KEGG enrichment showed that DEGs were most enriched in ribosomes, while also having enrichment in peroxide, endocytosis, the lysosome, autophagy, and mitophagy. In particular, mitophagy and peroxisome have been reported in medicine as the main mechanisms of reactive oxygen species (ROS) scavenging, while the lysosome and endocytosis are an important organelle and physiological process, respectively, that assist mitophagy. The oxidative stress experiments showed that the oxidative stress resistance of the RII strains was significantly higher than that of the RI strains: specifically, it was more than 1.8-fold higher at a concentration of 0.12% H2O2. This indicates that there is indeed a significant difference in the scavenging capacity of ROS between the two phenotypic strains. Therefore, we suggest that QoIs' action caused a high production of ROS, and that scavenging mechanisms such as mitophagy and peroxisomes functioned in RII strains to prevent oxidative stress, whereas RI strains were less capable of resisting oxidative stress, resulting in different resistance to QoIs. In this study, it was first revealed that mitophagy and peroxisome mechanisms available for ROS scavenging are involved in the resistance of pathogens to fungicides.

Breast Cancer Chemoresistance: Insights into the Regulatory Role of lncRNA

Long noncoding RNAs (lncRNAs) are a subclass of noncoding RNAs composed of more than 200 nucleotides without the ability to encode functional proteins. Given their involvement in critical cellular processes such as gene expression regulation, transcription, and translation, lncRNAs play a significant role in organism homeostasis. Breast cancer (BC) is the second most common cancer worldwide and evidence has shown a relationship between aberrant lncRNA expression and BC development. One of the main obstacles in BC control is multidrug chemoresistance, which is associated with the deregulation of multiple mechanisms such as efflux transporter activity, mitochondrial metabolism reprogramming, and epigenetic regulation as well as apoptosis and autophagy. Studies have shown the involvement of a large number of lncRNAs in the regulation of such pathways. However, the underlying mechanism is not clearly elucidated. In this review, we present the principal mechanisms associated with BC chemoresistance that can be directly or indirectly regulated by lncRNA, highlighting the importance of lncRNA in controlling BC chemoresistance. Understanding these mechanisms in deep detail may interest the clinical outcome of BC patients and could be used as therapeutic targets to overcome BC therapy resistance.

Mitochondrial transplantation strategies in multifaceted induction of cancer cell death

Otto Warburg hypothesized that some cancer cells reprogram their metabolism, favoring glucose metabolism by anaerobic glycolysis (Warburg effect) instead of oxidative phosphorylation, mainly because the mitochondria of these cells were damaged or dysfunctional. It should be noted that mitochondrial apoptosis is decreased because of the dysfunctional mitochondria. Strategies like mitochondrial transplantation therapy, where functional mitochondria are transplanted to cancer cells, could increase cell death, such as apoptosis, because the intrinsic apoptosis mechanisms would be reactivated. In addition, mitochondrial transplantation is associated with the redox state, which could promote synergy with common anticancer treatments such as ionizing radiation, chemotherapy, or radiotherapy, increasing cell death due to the presence or decrease of oxidative stress. On the other hand, mitochondrial transfer, a natural process for sharing mitochondrial between cells, induces an increase in chemoresistance and invasiveness in cancer cells that receive mitochondria from cells of the tumor microenvironment (TME), which indicates an antitumor therapeutic target. This review focuses on understanding mitochondrial transplantation as a therapeutic outcome induced by a procedure in aspects including oxidative stress, metabolism shifting, mitochondrial function, auto-/mitophagy, invasiveness, and chemoresistance. It also explores how these mechanisms, such as apoptosis, necroptosis, and parthanatos, impact cell death pathways. Finally, it discusses the chemoresistance and invasiveness in cancer cells associated with mitochondria transfer, indicating an antitumor therapeutic target.

Identification of the mitophagy-related diagnostic biomarkers in hepatocellular carcinoma based on machine learning algorithm and construction of prognostic model

Background and aims

As a result of increasing numbers of studies most recently, mitophagy plays a vital function in the genesis of cancer. However, research on the predictive potential and clinical importance of mitophagy-related genes (MRGs) in hepatocellular carcinoma (HCC) is currently lacking. This study aimed to uncover and analyze the mitophagy-related diagnostic biomarkers in HCC using machine learning (ML), as well as to investigate its biological role, immune infiltration, and clinical significance.

Methods

In our research, by using Least absolute shrinkage and selection operator (LASSO) regression and support vector machine- (SVM-) recursive feature elimination (RFE) algorithm, six mitophagy genes (ATG12, CSNK2B, MTERF3, TOMM20, TOMM22, and TOMM40) were identified from twenty-nine mitophagy genes, next, the algorithm of non-negative matrix factorization (NMF) was used to separate the HCC patients into cluster A and B based on the six mitophagy genes. And there was evidence from multi-analysis that cluster A and B were associated with tumor immune microenvironment (TIME), clinicopathological features, and prognosis. After then, based on the DEGs (differentially expressed genes) between cluster A and cluster B, the prognostic model (riskScore) of mitophagy was constructed, including ten mitophagy-related genes (G6PD, KIF20A, SLC1A5, TPX2, ANXA10, TRNP1, ADH4, CYP2C9, CFHR3, and SPP1).

Results

This study uncovered and analyzed the mitophagy-related diagnostic biomarkers in HCC using machine learning (ML), as well as to investigate its biological role, immune infiltration, and clinical significance. Based on the mitophagy-related diagnostic biomarkers, we constructed a prognostic model(riskScore). Furthermore, we discovered that the riskScore was associated with somatic mutation, TIME, chemotherapy efficacy, TACE and immunotherapy effectiveness in HCC patients.

Conclusion

Mitophagy may play an important role in the development of HCC, and further research on this issue is necessary. Furthermore, the riskScore performed well as a standalone prognostic marker in terms of accuracy and stability. It can provide some guidance for the diagnosis and treatment of HCC patients.