bims-miptne 2026-03-01 papers

bims-miptne

Biomed News

on Mitochondrial permeability transition pore-dependent necrosis

Issue of 2026–03–01
nine papers selected by
Oluwatobi Samuel Adegbite, University of Liverpool

Phenotypic CRISPR screens identify NLRX1 as an essential activator of the human mitochondrial permeability transition.
Sex differences in mitochondrial Ca2+ during ischemia/reperfusion injury: A role for S-Nitrosylation.
Melatonin and mitochondrial protection in cardiac ischemia-reperfusion injury: mechanisms, evidence and translational perspectives.
Mitochondria in Renal Ischemia-Reperfusion Injury: From Mechanisms to Therapeutics.
Electric field stimulation in Caenorhabditis elegans as a novel approach to investigate mitochondrial Ca2+ homeostasis during in vivo muscle aging.
Mitochondrial Permeability Transition in Skeletal Muscle Phenocopies Muscle Alterations seen in Cancer Cachexia and other Wasting Conditions.
Prognostic significance of calcium signaling-related genes in bladder cancer and the role of ATP2B4 in regulating mitochondrial calcium ion levels via the VDAC1/MCU pathway.
Reversible dissociation of mitochondrial Complex V balances anabolic and energy-generating needs in cancer.
Mitochondria at the Crossroads of Cardiovascular Disease: Mechanistic Drivers and Emerging Therapeutic Strategies.

Proc Natl Acad Sci U S A. 2026 Mar 03. 123(9): e2535298123

Phenotypic CRISPR screens identify NLRX1 as an essential activator of the human mitochondrial permeability transition.

William C Valinsky, Robert P Ray, Kathy S Schaefer, Jonathan B Grimm, Carla Nicolini, Luke D Lavis, David E Clapham.

  The mitochondrial permeability transition (mPT) is an evolutionarily conserved destructive process that permeabilizes the inner mitochondrial membrane in response to calcium overload. The molecular mechanism underlying the mPT is not established. To unambiguously identify essential proteins, we designed two phenotypic assays for mitochondrial calcium overload and applied them to FACS-based CRISPR screening in human cells, ultimately evaluating 19,113 genes. The first screen studied mitochondrial membrane potential (MMP) collapse in response to calcium overload. Top-ranked genes were the essential proteins of the mitochondrial calcium uniporter complex, MCU and EMRE, reflecting that the calcium-induced MMP collapse results from mitochondrial calcium entry and not the mPT. The second screen measured the permeability of the inner mitochondrial membrane. Here, the fluorescent interaction of a membrane impermeant ~600 Da dye and a mitochondrial-targeted HaloTag protein was studied under mPT activating conditions; calcium overload and the thiol-reactive molecule phenylarsine oxide. With secondary validation, we identified four protein-encoding genes that delayed or prevented the mPT under knockout: NF2, REST, BPTF, and NRLX1. Knockout of the nonmitochondrial proteins BPTF, NF2, or REST increased mitochondrial calcium retention capacity (CRC). However, calcium release or sensitivity to cyclosporin A (CsA) persisted, indicative of mPT sensitizers. Only knockout of the mitochondrial matrix protein, NLRX1, increased CRC, abolished calcium release, and was CsA-insensitive. This top-ranked hit of the mitochondrial permeability screen meets the definition of an essential mPT activator. Integral membrane proteins, including all previously proposed mPT candidates, were not essential activators.

Keywords:  MCU; NLRX1; calcium; mitochondria; permeability transition

DOI:  https://doi.org/10.1073/pnas.2535298123
J Mol Cell Cardiol. 2026 Feb 19. pii: S0022-2828(26)00031-3. [Epub ahead of print]214 1-10

Sex differences in mitochondrial Ca2+ during ischemia/reperfusion injury: A role for S-Nitrosylation.

Barbara Roman, Courtney E Petersen, Junhui Sun, Elizabeth Murphy.

  Sex differences in cardiac ischemia/reperfusion (I/R) injury have been reported, but the mechanisms underlying these differences remain poorly understood. As mitochondrial Ca2+ accumulation plays an important role in I/R injury, we examined whether sex specific differences occur. To monitor mitochondrial Ca2+ in Langendorff perfused hearts, we used a genetically encoded, mitochondrially targeted Ca2+ indicator (R-GECO1) delivered via an adeno-associated viral vector (AAV9). Male hearts accumulated significantly more mitochondrial Ca2+ during 20 min of ischemia than female hearts. Interestingly, sex differences in Ca2+ accumulation during ischemia were not observed in hearts from mice lacking the mitochondrial Ca2+ uniporter (MCU), suggesting an important role for MCU. As nitric oxide (NO) and its posttranslational modification S-nitrosylation have been suggested to modulate sex differences in Ca2+ homeostasis, we inhibited NO signaling in female hearts, which increased mitochondrial Ca2+ accumulation, while treatment of male hearts with an NO donor reduced mitochondrial Ca2+ levels, indicating that S-nitrosylation modulates Ca2+ uptake during ischemia in a sex-dependent manner. Using a biotin-switch assay in isolated mitochondria, we found increased S-nitrosylation of MCU in females compared to males. Finally, isolated male mitochondria exposed to an NO donor exhibited reduced Ca2+ uptake, comparable to untreated female mitochondria. Taken together, these findings suggest that S-nitrosylation of MCU reduces mitochondrial Ca2+ uptake during ischemia, uncovering a new layer of redox regulated mitochondrial function, with sex as a critical determinant.

Keywords:  Ischemia-reperfusion; MCU; Mitochondrial calcium; S-Nitrosylation; Sex differences

DOI:  https://doi.org/10.1016/j.yjmcc.2026.02.007
Basic Res Cardiol. 2026 Feb 24.

Melatonin and mitochondrial protection in cardiac ischemia-reperfusion injury: mechanisms, evidence and translational perspectives.

Gaia Pedriali, Sara Leo, Margherita Tiezzi, Elena Nicoletta Colarusso, Giampaolo Morciano, Elena Tremoli, Paolo Pinton.

  Cardiac ischemia-reperfusion injury (IRI) leads to significant mitochondrial impairment, which contributes to cell death and hampers myocardial recovery. During IRI, mitochondria are subjected to oxidative stress, calcium overload, and altered dynamics, resulting in the opening of the mitochondrial permeability transition pore (mPTP), release of cytochrome c, and activation of apoptotic pathways. Melatonin, a pleiotropic indoleamine produced by the pineal gland and other tissues, has cardioprotective effects through both direct antioxidant activity and receptor-mediated mechanisms. This review explores melatonin's role in maintaining mitochondrial integrity under IRI conditions. Melatonin counteracts oxidative damage by neutralizing reactive oxygen species, stabilizing mitochondrial membrane potential, and preventing mPTP opening, thereby reducing activation of cell death pathways. It also supports mitochondrial biogenesis and dynamics, contributing to energy balance and reduced oxidative burden. In addition, melatonin regulates mitophagy, ensuring mitochondrial quality control and preventing excessive degradation, which collectively contributes to restoring mitochondrial function and cellular metabolism. In rodent preclinical models, melatonin administration before ischemia, during ischemia, or at reperfusion has consistently reduced infarct size and improved cardiac function. While these preclinical findings are encouraging, studies on rabbits or pigs and clinical studies have not consistently replicated these benefits. The variability in outcomes may be attributed to differences in study design, timing and method of melatonin administration, and types of endpoints measured. Comorbidities, risk factors, and comedications further influence mitochondrial biology and melatonin's efficacy in cardiac IRI. A dedicated comparative analysis evaluates melatonin against established and emerging cardioprotective approaches targeting mitochondria, underscoring its potential for combination therapies.

Keywords:  Cardiac ischemia reperfusion injury; Cardioprotection; Melatonin; Mitochondria

DOI:  https://doi.org/10.1007/s00395-026-01162-z
Biomedicines. 2026 Jan 29. pii: 310. [Epub ahead of print]14(2):

Mitochondria in Renal Ischemia-Reperfusion Injury: From Mechanisms to Therapeutics.

Yijun Pan, Jiefu Zhu.

  Renal ischemia-reperfusion injury (IRI) is a leading trigger of acute kidney injury (AKI), a syndrome with high incidence and mortality worldwide. The kidney is among the most energy-demanding organs; its mitochondrial content is second only to the heart, rendering renal function highly contingent on mitochondrial integrity. Accumulating evidence places mitochondria at the center of IRI pathogenesis. During ischemia, ATP depletion, ionic disequilibrium, and Ca2+ overload set the stage for injury; upon reperfusion, a burst of mitochondrial reactive oxygen species (mtROS), collapse of the mitochondrial membrane potential (ΔΨm), aberrant opening of the mitochondrial permeability transition pore (mPTP), mitochondrial DNA (mtDNA) damage, and release of mitochondrial damage-associated molecular patterns (mtDAMPs) further amplify inflammation and drive regulated cell-death programs. In recent years, the centrality of mitochondrial bioenergetics, quality control, and immune signaling in IRI-AKI has been increasingly recognized. Building on advances from the past five years, this review synthesizes mechanistic insights into mitochondrial dysfunction in renal IRI and surveys mitochondria-targeted therapeutic strategies-including antioxidant defenses, reinforcement of mitochondrial quality control (biogenesis, dynamics, mitophagy), and modulation of mtDAMP sensing-with the aim of informing future translational efforts in AKI.

Keywords:  AKI; antioxidant defenses; mitochondria; mitochondria-targeted therapy; mitochondrial DNA; mitochondrial quality control; mtDAMPs; renal ischemia–reperfusion injury

DOI:  https://doi.org/10.3390/biomedicines14020310
Methods. 2026 Feb 19. pii: S1046-2023(26)00035-6. [Epub ahead of print]

Electric field stimulation in Caenorhabditis elegans as a novel approach to investigate mitochondrial Ca2+ homeostasis during in vivo muscle aging.

Sonja Gabrijelčič, Doruntina Bresilla, Fabienne Mossegger, Ernst Malle, Vedran Đerek, Martin Hirtl, Corina T Madreiter-Sokolowski.

  Mitochondrial calcium ([Ca2+]mito) homeostasis is a key regulator of cellular physiology, controlling signal transduction, energy metabolism, and cell survival. To examine how these processes change with age in vivo, we used the pharyngeal muscle of Caenorhabditis elegans (C. elegans) as a tractable model for studying [Ca2+]mito dynamics. We introduced electric field stimulation as a robust trigger for [Ca2+]mito uptake that overcomes limitations of compound stimulation, which relies on pharyngeal pumping and endoplasmic reticulum store filling and is typically confined to single-stimulus protocols. In contrast, electric field stimulation enables physiologically relevant repeated excitation that challenges [Ca2+]mito uptake and recovery. Stimulation with 10 V for 10 s reliably evoked reproducible [Ca2+]mito transients in the pharyngeal muscle of C. elegans and produced higher responder rates than compound stimulation. Basal [Ca2+]mito increased with age, and the first field-evoked transient was significantly larger in aged animals, an effect not detected with pharmacological triggers. Repeated pulses unmasked cumulative [Ca2+]mito loading and incomplete recovery in aged pharynx, indicative of [Ca2+]mito overload, which was attenuated by inhibition of the mitochondrial Ca2+ uniporter (MCU) with mitoxantrone. Regional analyses identified the corpus as a hotspot for electric field-evoked [Ca2+]mito uptake and overload, while MCU inhibition reduced repeated responses in both corpus and posterior bulb. Electric field stimulation enables precise, repeated in vivo probing of [Ca2+]mito uptake and recovery, revealing overload in the C. elegans pharynx. This approach identified age-enhanced, MCU-dependent, and region-specific [Ca2+]mito loading, providing a pathophysiologically relevant readout of impaired Ca2+ handling that may contribute to age-related muscle dysfunction.

Keywords:  Aging; Caenorhabditis elegans; Electric field stimulation; Mitochondrial calcium homeostasis; Muscle

DOI:  https://doi.org/10.1016/j.ymeth.2026.02.011
bioRxiv. 2026 Feb 13. pii: 2026.02.12.705530. [Epub ahead of print]

Mitochondrial Permeability Transition in Skeletal Muscle Phenocopies Muscle Alterations seen in Cancer Cachexia and other Wasting Conditions.

Maya Semel, Cole Lukasiewicz, Sarah Skinner, Mark R Viggars, Martin Picard, Abbey-Gale Mannings, Michael Cohen, Dennis Wolan, Terence E Ryan, Russell T Hepple.

Background: Skeletal muscle in wasting conditions often exhibits a common set of phenotypes that include atrophy, mitochondrial respiratory dysfunction, and fragmentation of the acetylcholine receptor (AChR) cluster at the endplate. Mitochondria are frequently implicated in driving muscle pathology in these conditions, although which aspects of mitochondrial function are most relevant is poorly understood.
Methods: To address this gap, we focused on mitochondrial permeability transition (mPT), a well-established pathological mechanism in ischemia-reperfusion injury and neurodegeneration but poorly studied in skeletal muscle. We performed a broad assessment of the consequences of mPT in skeletal muscle, focusing on features that are common in wasting conditions. We then tested whether tumor-host factors could promote mPT and compared differentially expressed genes (DEGs) with mPT and a mouse model of pancreatic cancer cachexia.
Results: Inducing mPT in mouse skeletal muscle bundles in a Ca 2+ retention capacity assay progressively altered mitochondrial morphology, beginning with cristae swirling and condensation, progressing to mitochondrial cristae displacement, and culminating in breach of the outer mitochondrial membrane; features that are common in wasting conditions. Inducing mPT with Bz423 in single mouse muscle fibers increased mROS and Caspase 3 (Casp3) activity and was prevented by inhibitors of mPT, mROS or Casp3. Incubating single muscle fibers with Bz423 for 24 h reduced fiber diameter by ∼20% which was prevented by inhibiting mPT, mROS, or Casp3. Inducing mPT caused a complex I-specific mitochondrial respiratory impairment and increased co-localization of lysosomes with mitochondria. Inducing mPT also fragmented the AChR cluster at the muscle endplate and was prevented by inhibiting mPT or Casp3. The Ca 2+ threshold for mPT and mitochondrial calcein colocalization were reduced by pancreatic tumor-conditioned media in skeletal muscle or C2C12 myoblasts, respectively, and these effects were counteracted by mPT inhibition or cyclophilin D knockout. Finally, there was significant overlap between the transcriptome of mPT and that seen in diaphragm muscle in a mouse model of pancreatic cancer cachexia, particularly during the muscle wasting phase.
Conclusions: We conclude that inducing mPT in skeletal muscle recapitulates muscle phenotypes common with muscle wasting conditions like cachexia. Furthermore, mPT is engaged by tumor-host factors and had significant overlap with DEGs seen during the muscle wasting phase in a mouse model of pancreatic cancer cachexia, warranting further investigation of mPT as a therapeutic target.

DOI: https://doi.org/10.64898/2026.02.12.705530
Front Immunol. 2026 ;17 1561666

Prognostic significance of calcium signaling-related genes in bladder cancer and the role of ATP2B4 in regulating mitochondrial calcium ion levels via the VDAC1/MCU pathway.

Lulu Zhang, Yu Gong, Jiajun Chen, Mengyao Li, Xiurong Wang, Weihao Wang, Qiannan Ding, Yulei Li.

   Background: Calcium signaling, as a ubiquitous intracellular signal in eukaryotes, has been impacted in multiple biological processes encompassing tumorigenesis. Nevertheless, the integrated investigations on the function and prognostic value of genes correlated to calcium signaling in bladder cancer (BLCA) were still lacking.
Methods: The transcriptome data and clinical data from BLCA patients were obtained from TCGA and GEO databases. Genes associated with calcium signaling that are differentially expressed in normal and malignant tissues were identified. Cox analysis and the least absolute shrinkage and selection operator (LASSO) analysis were employed to identify prognostic genes and develop a prognostic signature. The tuning parameter (λ) for LASSO regression was determined by cross-validation. The outcomes were then confirmed using an external independent dataset (GSE32894). The prognostic signature's reliability was assessed utilizing Kaplan-Meier, PCA, t-SNE, and ROC analyses. Furthermore, both univariate and multivariate Cox regression studies were undertaken to ensure if the prognostic signature functioned as an autonomous prognostic indication. Moreover, we examined the connection between the immune cell infiltration, the tumor mutation burden (TMB), and the prognostic signature. The Genomics of Drug Sensitivity in Cancer (GDSC) database and the IMvigor210 dataset were deployed to forecast the treatment reactions of the prognostic signature. Ultimately, the functionality of ATP2B4 was confirmed by in vitro and in vivo tests.
Results: Thirty-two differentially expressed calcium signaling-correlated genes were identified in the TCGA dataset. A prognostic signature containing six genes (ATP2B4, BDKRB2, EDNRA, PDGFRA, EGFR, and ADCY7) was ascertained to anticipate the overall survival of BLCA. Furthermore, a nomogram containing risk scores with age was developed to anticipate the BLCA patient's prognosis. In addition, patients among the high- and low-risk groups displayed significant variation in TMB, immune infiltration landscape, and response to chemotherapy and immunotherapy. ATP2B4 has been recognized as a pivotal oncogenic gene. The suppression of ATP2B4 results in elevated cytoplasmic calcium ion(Ca2+) concentrations, which in turn activate the VDAC1/MCU pathway. This activation facilitates the transfer of Ca2+ from the cytoplasm to the mitochondria, culminating in mitochondrial Ca2+ overload and ultimately inducing apoptosis in bladder urothelial carcinoma (BLCA) cells.
Conclusions: Collectively, we have developed a unique genetic signature that is based on genes associated with calcium signaling. This signature possesses the capacity to precisely anticipate the survival prognosis and therapeutic response of BLCA patients and might have a crucial role in guiding clinical treatment. Furthermore, ATP2B4 has been identified as a crucial oncogenic gene. The downregulation of ATP2B4 leads to mitochondrial Ca2+ overload, ultimately resulting in apoptosis of BLCA cells.

Keywords:  ATP2B4; BLCA; VDAC1/MCU; biomarker; calcium signaling; immunotherapy

DOI:  https://doi.org/10.3389/fimmu.2026.1561666
iScience. 2026 Mar 20. 29(3): 114889

Reversible dissociation of mitochondrial Complex V balances anabolic and energy-generating needs in cancer.

Huabo Wang, Jie Lu, Colin Henchy, Steven J Mullett, Adam C Richert, Eric S Goetzman, Ahmet Toksoz, Leonardo Hale, Brandon B Wang, Nelli Mnatsakanyan, Edward V Prochownik.

  Cancer cell metabolic re-programming provides the additional energy and anabolic precursors necessary to sustain unregulated proliferation. This is partially mediated by the Warburg effect, which generates ATP while oxidizing glucose to a subset of these anabolites. Concurrently, mitochondrial mass and ATP generation via oxidative phosphorylation decline in most tumors. This raises the question of how increased glycolysis-derived anabolites can be balanced with those supplied by the TCA cycle. Using primary murine liver cancers and their derivative cell lines, we show that this can be explained by the dissociation of mitochondrial Complex V (CV or ATP synthase) into its component and functionally independent Fo and F1 domains. This occurs as a result of marked declines in MT-ATP6, a CV subunit that stabilizes Fo-F1 assembly. Serving as a proton pore, free Fo maintains a normal mitochondrial membrane potential without generating ATP, thus allowing the TCA cycle, electron transport chain, and anaplerotic reactions to function at high levels. Concurrently, free F1 functions in reverse as an ATPase to limit excess ATP accumulation. The uncoupling of TCA-cycle-derived anabolic substrate production from membrane hyperpolarization and ATP overproduction by a smaller population of highly efficient mitochondria allows TCA-cycle-generated anabolic precursors to match those generated via glycolysis.

Keywords:  Biochemistry; Cancer; Molecular biology

DOI:  https://doi.org/10.1016/j.isci.2026.114889
Cells. 2026 Feb 20. pii: 372. [Epub ahead of print]15(4):

Mitochondria at the Crossroads of Cardiovascular Disease: Mechanistic Drivers and Emerging Therapeutic Strategies.

Sonila Alia, Gaia Pedriali, Paolo Compagnucci, Yari Valeri, Valentina Membrino, Tiziana Di Crescenzo, Elena Tremoli, Laura Mazzanti, Arianna Vignini, Paolo Pinton, Michela Casella.

  Mitochondria are central regulators of cardiac homeostasis, integrating energy production, redox balance, calcium handling, and innate immune signaling. In cardiovascular disease (CVD), mitochondrial dysfunction acts as a unifying mechanism connecting oxidative stress, metabolic inflexibility, inflammation, and structural remodeling. Disturbances in mitochondrial quality control-encompassing fusion-fission dynamics, PINK1/Parkin- and receptor-mediated mitophagy, biogenesis, and proteostasis-compromise mitochondrial integrity and amplify cardiomyocyte injury. Excess reactive oxygen species, mitochondrial DNA release, and calcium overload further activate cGAS-STING, NLRP3 inflammasomes, and mPTP-driven cell death pathways, perpetuating maladaptive remodeling. Therapeutic strategies targeting mitochondrial dysfunction have rapidly expanded, ranging from mitochondria-targeted antioxidants (such as MitoQ and SS-31), nutraceuticals, metabolic modulators (SGLT2 inhibitors, metformin), and mitophagy or biogenesis activators to innovative approaches including mtDNA editing, nanocarrier-based delivery, and mitochondrial transplantation. These interventions aim to restore organelle structure, improve bioenergetics, and reestablish balanced quality control networks. This review integrates recent mechanistic insights with emerging translational evidence, outlining how mitochondria function as bioenergetic and inflammatory hubs in CVD. By synthesizing established and next-generation therapeutic strategies, it highlights the potential of precision mitochondrial medicine to reshape the future management of cardiovascular disease.

Keywords:  cardiovascular disease; inflammation; mitochondrial dysfunction; mitochondrial quality control; mitochondrial signaling; mitophagy; oxidative stress

DOI:  https://doi.org/10.3390/cells15040372