bims-miptne Biomed News
on Mitochondrial permeability transition pore-dependent necrosis
Issue of 2025–02–23
nine papers selected by
Oluwatobi Samuel Adegbite, University of Liverpool



  1. J Pharmacol Exp Ther. 2024 Dec 24. pii: S0022-3565(24)42178-2. [Epub ahead of print]392(3): 100529
      Acute, high-dose metformin (MET, 2 mM) results in partial complex I inhibition in ischemia (ISC)-modified mitochondria. Mitochondrial permeability transition pore (MPTP) opening increases cardiac injury during ISC-reperfusion (REP). We evaluated whether MET (2 mM) can decrease MPTP opening in aged hearts during REP. Sestrin2 (Sesn2) regulates metabolism through activation of AMP-dependent protein kinase. Sesn2 decreases in aged hearts. The knockout (KO) of Sesn2 mimics the aging phenotype. Inactivation of glycogen synthase kinase-3 β (GSK-3β) via serine-9 phosphorylation decreases MPTP opening. We assessed if 2 mM MET given during early REP can decrease cardiac injury by partial blockade of complex I with decreased MPTP opening and if the protection depends on Sesn2-mediated GSK-3β phosphorylation. C57BL/6BJ male mice (22-24 months) and adult Sesn2 KO mice were evaluated. MET dose-dependently inhibited NADH oxidase activity in permeabilized mitochondria in both aged and Sesn2 KO greater after 25 minutes of ISC. MET (2 mM) given during REP decreased infarct size in aged hearts. MET improved calcium retention capacity in both aged wild-type and adult Sesn2 KO mice. MET treatment only increased phosphorylation of GSK-3β in aged heart mitochondria but not in Sesn2 KO hearts. Thus, high-dose MET at REP partially inhibits complex I and decreases MPTP opening. The decreased MPTP susceptibility downstream of complex I inhibition is not fully dependent on GSK-3β inhibition. Complex I downregulation with acute, high-dose MET has translational potential to protect the aged heart. SIGNIFICANCE STATEMENT: This study explores the efficacy and mechanism of acute high-dose metformin treatment in reducing mitochondrial-driven cardiac injury during reperfusion after stop-flow ischemia in the high-risk aged heart. Metformin dose-dependently inhibits complex I (NADH oxidation) in ischemia-altered mitochondria. Metformin given during early reperfusion mitigated MPTP opening as the mechanism of decreased reperfusion injury. Thus, modulation of complex I via metformin at reperfusion has potential translational application to mitigate injury during ST-elevation myocardial infarction in the high-risk aged heart.
    Keywords:  AMP kinase; Mitochondria; Mitochondrial permeability transition pore; Myocardial infarction; Reactive oxygen species
    DOI:  https://doi.org/10.1016/j.jpet.2024.100529
  2. Liver Res. 2024 Mar;8(1): 46-53
       Background and aim: The liver is susceptible to ischemia-reperfusion injury (IRI) during hepatic surgery, when the vessels are compressed to control bleeding, or liver transplantation, when there is an obligate period of ischemia. The hallmark of IRI comprises mitochondrial dysfunction, which generates reactive oxygen species, and cell death through necrosis or apoptosis. Cyclosporine (CsA), which is a well-known immunosuppressive agent that inhibits calcineurin, has the additional effect of inhibiting the mitochondrial permeability transition pore (mPTP), thereby, preventing mitochondrial swelling and injury. NIM-811, which is the nonimmunosuppressive analog of CsA, has a similar effect on the mPTP. In this study, we tested the effect of both agents on mitigating warm hepatic IRI in a murine model.
    Materials and methods: Before ischemic insult, the mice were administered with intraperitoneal normal saline (control); CsA at 2.5, 10, or 25 mg/kg; or NIM-811 at 10 mg/kg. Thereafter, the mice were subjected to partial warm hepatic ischemia by selective pedicle clamping for 60 min, followed by 6 h of recovery after reperfusion. Serum alanine transaminase (ALT) was measured, and the liver tissue was examined histologically for the presence of apoptosis and the levels of inflammatory cytokines.
    Results: Compared with the control mice, the mice treated with 10 and 25 mg/kg of CsA and NIM-811 had significantly lower ALT levels (P < 0.001, 0.007, and 0.031, respectively). Moreover, the liver tissue showed reduced histological injury scores after treatment with CsA at 2.5, 10, and 25 mg/kg and NIM-811 (P = 0.041, <0.001, 0.003, and 0.043, respectively) and significant decrease in apoptosis after treatment with CsA at all doses (P = 0.012, 0.007, and <0.001, respectively). Levels of the pro-inflammatory cytokines, particularly interleukin (IL)-1β, IL-2, IL-4, IL-10, and keratinocyte chemoattractant/human growth-regulated oncogene significantly decreased in the mice treated with the highest dose of CsA (25 mg/kg) than those in the control mice.
    Conclusions: Premedication with CsA or NIM-811 mitigated hepatic IRI in mice, as evidenced by the decreased ALT and reduced injury on histology. These results have potential implications on mitigating IRI during liver transplantation and resection.
    Keywords:  Animal model; Cyclosporine (CsA); Cyclosporine analogue; Ischemia-reperfusion injury (IRI); Liver surgery; NIM-811
    DOI:  https://doi.org/10.1016/j.livres.2024.02.002
  3. Eur J Med Res. 2025 Feb 18. 30(1): 113
       BACKGROUND: Breast cancer is a highly prevalent tumor worldwide. Mitochondrial permeability transition (MPT)-driven necrosis is a novel type of cell death induced by mitochondrial membrane disruption. The roles of MPT-driven necrosis in breast cancer remain unclear.
    METHODS: Gene expression and clinicopathologic features were extracted from The Cancer Genome Atlas and Gene Expression Omnibus. We performed a genome landscape analysis of MPT-driven necrosis (MPTdn)-related genes, and a consensus clustering analysis was conducted to construct MPTdn clusters. Next, a risk model was established based on the differentially expressed genes related to MPTdn. We grouped and used external data sets to verify the stability of the model. Subsequently, immune correlation analysis, clinical correlation assessment and drug sensitivity analysis were conducted. Finally, candidate genes were validated in the protein and mRNA levels.
    RESULTS: A total of 39 MPTdn-related genes were identified in our analysis. Most MPTdn-related genes had different expression levels and somatic mutations in breast cancer, and a close interaction was noted among them. A risk model composed of BCL2A1, SCUBE2, NPY1R and CLIC6 was constructed. The low-risk group had better overall survival and higher immune infiltration levels. All three external data sets achieved excellent predictive efficacy. Finally, the immunohistochemistry results indicated that BCL2A1, SCUBE2, NPY1R and CLIC6 were expressed at significantly lower levels in breast cancer tissues, and the transcriptome sequencing results revealed that BCL2A1 and SCUBE2 mRNA expression levels were greater in the nonrecurrence group.
    CONCLUSIONS: We developed a risk model with excellent predictive efficacy based on MPTdn and revealed that BCL2A1, SCUBE2, NPY1R and CLIC6 could be used as the biomarkers, laying a solid foundation for investigations of therapeutic targets of breast cancer.
    Keywords:  Breast cancer; Drug sensitivity; Immunotherapy; MPT-driven necrosis; Prognosis
    DOI:  https://doi.org/10.1186/s40001-025-02370-4
  4. Biochim Biophys Acta Mol Basis Dis. 2025 Feb 18. pii: S0925-4439(25)00076-6. [Epub ahead of print] 167731
      MicroRNAs (miRNAs) are a class of small non-coding RNAs that are associated with biochemical pathways through the post-transcriptional regulation of gene expression in different cell types. Based on their expression pattern and function, miRNAs can have oncogenic and tumor suppressor activities in different cancer cells. Altered mitochondrial function and bioenergetics are known hallmarks of cancer cells. Mitochondria play a central role in metabolic reprogramming during cancer progression. Cancer cells exploit mitochondrial function for cell proliferation, invasion, migration and metastasis. Genetic and epigenetic changes in nuclear genome contribute to altered mitochondrial function and metabolic reprogramming in cancer cells. Recent studies have identified the role of miRNAs as major facilitators of anterograde and retrograde signaling between the nucleus and mitochondria in cancer cells. Detailed analysis of the miRNA-mediated regulation of mitochondrial function in cancer cells may provide new avenues for the diagnosis, prognosis, and therapeutic management of the disease. Our review aims to discuss the role of miRNAs in nuclear-mitochondria crosstalk regulating mitochondrial functions in different cancer types. We further discussed the potential application of mitochondrial miRNAs (mitomiRs) targeting mitochondrial biogenesis and metabolism in developing novel cancer therapy.
    Keywords:  Cancer; Cancer therapeutics; MicroRNA; MitomiRs; Nuclear-mitochondria communication
    DOI:  https://doi.org/10.1016/j.bbadis.2025.167731
  5. Front Oncol. 2025 ;15 1516785
       Background: Lactate's perception of lactate has changed over the last 30 years from a straightforward metabolic byproduct to a complex chemical with important biological activities, such as signal transduction, gluconeogenesis, and mitochondrial respiration. In addition to its metabolic contributions, lactate has far-reaching repercussions. This review highlights the role of lactate in the course of cancer by highlighting lactylation as a unique epigenetic alteration. The purpose of this review is to clarify the functions of lactate in the biology of tumors, with a particular focus on the translational potential of lactylation pathways in cancer diagnosis and treatment approaches.
    Methods: This review summarizes research on the relationship between lactate and cancer, with an emphasis on histone lactylation, its effect on gene expression, and its influence on the tumor microenvironment. By establishing a connection between metabolic byproducts and epigenetic gene regulation, we investigated how lactylation affects immune regulation, inflammation, and cellular repair.
    Findings: Histone lactylation, or the addition of lactate to lysine residues on histone proteins, increases transcriptional activity and facilitates the expression of genes involved in homeostasis and repair. These findings have important implications for cancer treatment. Lactylation, for example, activates genes such as Arg1, which is a hallmark of the M2 macrophage phenotype implicated in immunosuppression and tumor growth. The ability of lactate to dynamically alter gene expression is further supported by its function as a histone deacetylase(HDAC)inhibitor and its impact on histone acetylation. Its wide-ranging involvement in cellular metabolism and epigenetic control has been demonstrated by the discovery of particular lactylation sites on histones in various cell types, including cancer cells.
    Keywords:  cancer metabolism; epigenetic modification; epigenetic regulation; histone; lactylation; tumor microenvironment
    DOI:  https://doi.org/10.3389/fonc.2025.1516785
  6. bioRxiv. 2025 Feb 08. pii: 2025.02.07.637120. [Epub ahead of print]
      Hexokinase (HK) catalyzes the synthesis of glucose-6-phosphate, marking the first committed step of glucose metabolism. Most cancer cells express two homologous isoforms (HK1 and HK2) that can each bind to the outer mitochondrial membrane (OMM). CRISPR screens across hundreds of cancer cell lines indicate that both are dispensable for cell growth in traditional culture media. By contrast, HK2 deletion impairs cell growth in Human Plasma-Like Medium (HPLM). Here, we find that HK2 is required to maintain sufficient cytosolic (OMM-detached) HK activity under conditions that enhance HK1 binding to the OMM. Notably, OMM-detached rather than OMM-docked HK promotes "aerobic glycolysis" (Warburg effect), an enigmatic phenotype displayed by most proliferating cells. We show that several proposed theories for this phenotype cannot explain the HK2 dependence and instead find that HK2 deletion severely impairs glycolytic ATP production with little impact on total ATP yield for cells in HPLM. Our results reveal a basis for conditional HK2 essentiality and suggest that demand for compartmentalized ATP synthesis underlies the Warburg effect.
    DOI:  https://doi.org/10.1101/2025.02.07.637120
  7. Autophagy. 2025 Feb 17.
      Lysosomes are essential membrane-bound organelles that integrate intracellular needs and external signals through multiple functions, including autophagy-mediated degradation and MTORC1 signaling. The integrity of the lysosomal membrane is therefore crucial for maintaining cellular homeostasis. Various endogenous and exogenous factors can damage lysosomes, contributing to diseases such as infections, cancer, and neurodegeneration. In response, cells mount defensive mechanisms to cope with such stress, including the formation of stress granules (SGs) - membraneless organelles composed of RNAs and protein complexes. While SGs have emerged as key players in repairing damaged lysosomes, how lysosomal damage triggers their formation and influences cell fate remains unclear. Here we report that the calcium signal from damaged lysosomes mediates SG formation and protects cells from lysosomal damage-induced cell death. Mechanistically, calcium leakage from damaged lysosomes signals the recruitment of calcium-activating protein PDCD6IP/ALIX and its partner PDCD6/ALG2. This complex recruits protein kinase EIF2AK2/PKR and its activator PRKRA/PACT, which phosphorylates translation initiator factor EIF2S1, stalling global translation initiation. This translation arrest leads to the accumulation of inactive messenger ribonucleoprotein complexes (mRNPs), resulting in SG formation. Cells deficient in SG formation show increased cell death when exposed to lysosomal damage from disease-associated factors including SARS-CoV-2ORF3a, adenovirus, malarial pigment, proteopathic MAPT/tau, or environmental hazards. Collectively, this study reveals how damaged lysosomes signal through calcium to trigger SG assembly, promoting cell survival. This establishes a novel link between membrane-bound and membraneless organelles, with implications for diseases involving lysosomal damage and SG dysfunction.
    Keywords:  Calcium signaling; cell survival; lysosomal damage; stress granules
    DOI:  https://doi.org/10.1080/15548627.2025.2468910
  8. Cancer Lett. 2025 Feb 18. pii: S0304-3835(25)00131-4. [Epub ahead of print] 217567
      Hepatocellular carcinoma (HCC) treatment options remain limited despite advances in targeted therapies for molecularly-defined cancers. To address tumor heterogeneity, we reconstructed HCC clonal evolution through single-cell RNA sequencing trajectory analysis, identifying 902 signature genes across seven cellular states. Weighted gene co-expression network analysis of public HCC datasets revealed tumor-grade-associated modules and established a 14-gene prognostic model linked to clonal evolution. Central to this model is the LDHA-NDRG1 axis - two hypoxia-responsive regulators showing coordinated spatiotemporal expression patterns during cancer progression. Dual-expressing cell lineages correlated with poor prognosis and senescence resistance through LDHA-mediated lactylation of histone H2B at K58 on NDRG1, an epigenetic mechanism connecting metabolic reprogramming to senescence evasion. Therapeutically, dual inhibition of this axis extended survival in metastatic HCC murine models. Our findings reveal that lactate-driven epigenetic modification via the LDHA-NDRG1 axis creates a molecularly distinct subpopulation enabling senescence resistance, providing mechanistic insights into HCC heterogeneity. This work proposes a precision medicine strategy targeting lactylation-mediated epigenetic regulation, with implications for developing combination therapies and patient stratification based on clonal evolution patterns.
    Keywords:  Cellular Senescence; Hepatocellular Carcinoma; Lactate Metabolism; Lactylation; N-Myc Downstream Regulated 1
    DOI:  https://doi.org/10.1016/j.canlet.2025.217567