The cell biology of mitochondrial membrane dynamics

Fibrotic scar formation after cerebral ischemic stroke: Targeting the Sonic hedgehog signaling pathway for scar reduction

JOURNAL/nrgr/04.03/01300535-202602000-00044/figure1/v/2025-05-05T160104Z/r/image-tiff Recent studies have shown that fibrotic scar formation following cerebral ischemic injury has varying effects depending on the microenvironment. However, little is known about how fibrosis is induced and regulated after cerebral ischemic injury. Sonic hedgehog signaling participates in fibrosis in the heart, liver, lung, and kidney. Whether Shh signaling modulates fibrotic scar formation after cerebral ischemic stroke and the underlying mechanisms are unclear. In this study, we found that Sonic Hedgehog expression was upregulated in patients with acute ischemic stroke and in a middle cerebral artery occlusion/reperfusion injury rat model. Both Sonic hedgehog and Mitofusin 2 showed increased expression in the middle cerebral artery occlusion rat model and in vitro fibrosis cell model induced by transforming growth factor-beta 1. Activation of the Sonic hedgehog signaling pathway enhanced the expression of phosphorylated Smad 3 and Mitofusin 2 proteins, promoted the formation of fibrotic scars, protected synapses or promoted synaptogenesis, alleviated neurological deficits following middle cerebral artery occlusion/reperfusion injury, reduced cell apoptosis, facilitated the transformation of meninges fibroblasts into myofibroblasts, and enhanced the proliferation and migration of meninges fibroblasts. The Smad3 phosphorylation inhibitor SIS3 reversed the effects induced by Sonic hedgehog signaling pathway activation. Bioinformatics analysis revealed significant correlations between Sonic hedgehog and Smad3, between Sonic hedgehog and Mitofusin 2, and between Smad3 and Mitofusin 2. These findings suggest that Sonic hedgehog signaling may influence Mitofusin 2 expression by regulating Smad3 phosphorylation, thereby modulating the formation of early fibrotic scars following cerebral ischemic stroke and affecting prognosis. The Sonic Hedgehog signaling pathway may serve as a new therapeutic target for stroke treatment.

Harmine derivative H-2-168 induces the death of Echinococcus granulosus by regulating mitochondrial fusion and fission

CONTEXT

H-2-168 has pharmacological effects similar to those of harmine, with less toxicity. The health of cells and organisms depends on a delicate balance between mitochondrial fusion and fission.

OBJECTIVE

This study investigated the roles of H-2-168 and mitochondrial fusion and fission in Echinococcus granulosus.

MATERIALS AND METHODS

Notably, E. granulosus were isolated from fresh sheep livers, and then treated with H-2-168 (25 μg/mL), mitochondrial division inhibitor 1 (Mdivi-1, 25 μg/mL) or the combination of H-2-168:Mdivi-1 (25 μg/mL:12.5 μg/mL). After 24 h of culture, the indices related to E. granulosus were measured. Additionally, Drp1 was knocked down to explore its effects on E. granulosus growth.

RESULTS

The EC50 values of H-2-168, Mdivi-1 and H-2-168:Mdivi-1 against E. granulosus were 44.171, 117.882 and 32.924 μg/mL, respectively. Compared with H-2-168 or Mdivi-1, the combination of H-2-168 and Mdivi-1 showed better inhibitory effects on E. granulosus viability, as well as increased levels of ROS and LDH, decreased ATP levels, inhibited mitochondrial activity and reduced mitochondrial membrane potential (p < 0.05), with the upregulation of Caspase-3, Cyt-c, Drp1, Fis1 and downregulation of Bcl-2, Mfn2 and OPA1. Additionally, Drp1 knockdown was successfully performed in E. granulosus, which significantly inhibited E. granulosus viability (p < 0.05) and further downregulated Mfn2 expression induced by H-2-168.

DISCUSSION AND CONCLUSION

Drp1 is closely associated with mitochondrial fusion and fission, and H-2-168 may promote E. granulosus death through disrupting the balance between mitochondrial fusion and fission.

Mitophagy in acute central nervous system injuries: regulatory mechanisms and therapeutic potentials

Acute central nervous system injuries, including ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage, traumatic brain injury, and spinal cord injury, are a major global health challenge. Identifying optimal therapies and improving the long-term neurological functions of patients with acute central nervous system injuries are urgent priorities. Mitochondria are susceptible to damage after acute central nervous system injury, and this leads to the release of toxic levels of reactive oxygen species, which induce cell death. Mitophagy, a selective form of autophagy, is crucial in eliminating redundant or damaged mitochondria during these events. Recent evidence has highlighted the significant role of mitophagy in acute central nervous system injuries. In this review, we provide a comprehensive overview of the process, classification, and related mechanisms of mitophagy. We also highlight the recent developments in research into the role of mitophagy in various acute central nervous system injuries and drug therapies that regulate mitophagy. In the final section of this review, we emphasize the potential for treating these disorders by focusing on mitophagy and suggest future research paths in this area.

Organelle-oriented nanomedicines in tumor therapy: Targeting, escaping, or collaborating?

Precise tumor therapy is essential for improving treatment specificity, enhancing efficacy, and minimizing side effects. Targeting organelles is a key strategy for achieving this goal and is a frontier research area attracting a considerable amount of attention. The concept of organelle targeting has a significant effect on the structural design of the nanodrugs employed. Most notably, the intricate interactions among different organelles in a tumor cell essentially create a unified system. Unfortunately, this aspect might have been somewhat overlooked when existing organelle-targeting nanodrugs were designed. In this review, we underscore the synergistic relationship among the various organelles and advocate for a holistic view of organelle-targeting design. Through the integration of biology and material science, recent advancements in organelle targeting, escaping, and collaborating are consolidated to offer fresh perspectives for the development of antitumor nanomedicines.

Identification of molecular subtypes and a prognostic risk model based on mitochondrial dynamic related genes in clear cell renal cell carcinoma

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) represents the most prevalent histological subtype and primary contributor to unfavorable prognosis in renal cancer. While mitochondrial dynamics serve as a critical quality control mechanism linked to tumor malignancy, their clinical significance and specific mechanisms in ccRCC remain poorly understood.

METHODS

Consnsuclusterplus was used to consensus clustering and molecular subtype screening, Kaplan-Meier analysis was used to analyze survival in different subtypes. PINK1 expression was detected by westernblot, and CCK8 is used to detect cell activity. Immunofluorescence staining of LC3 for evaluating mitochondrial autophagy levels.

RESULTS

In this study, we classified 534 ccRCC samples, identified from the UCSC XENA database, into A and B clusters based on 42 mitochondrial dynamic related genes. Cluster A demonstrated superior survival outcomes compared to cluster B. Subsequent analysis revealed significant inter-cluster differences in gene expression profiles, mutational spectra, and immune infiltration patterns. We established a mitochondrial dynamics-related prognostic model incorporating PINK1, NIPSNAP1, and MTFR2, with mitophagy-associated genes represented by PINK1 showing particular prognostic significance in ccRCC. Gene Ontology (GO) analysis indicated significant enrichment of mitophagy pathways in cluster A. Functional investigations demonstrated that PINK1-overexpressing cells exhibited increased sensitivity to sunitinib (lower IC50 values), whereas PINK1 knockdown conferred therapeutic resistance. Western blot and immunofluorescence analyses confirmed elevated mitophagy levels in PINK1-overexpressing cells under sunitinib treatment, contrasting with diminished mitophagy in PINK1-deficient cells.

CONCLUSIONS

Our findings advance the understanding of mitochondrial dynamics in ccRCC progression, demonstrating that PINK1-mediated enhancement of mitophagy critically potentiates the anti-tumor effects of sunitinib in ccRCC.

Acetaldehyde dehydrogenase 2 attenuates lipopolysaccharide -induced endothelial barrier damage by inhibiting mitochondrial fission in sepsis-associated encephalopathy

Sepsis-associated encephalopathy (SAE) is a common neurological complication of sepsis, and acetaldehyde dehydrogenase 2 (ALDH2) has been identified as a protective factor for endothelial cells against oxidative stress. In this study, we aimed to investigate the therapeutic potential of ALDH2 and its impact on mitochondrial dynamics using both mouse and brain microvascular endothelial cells (BMECs) injury models induced by lipopolysaccharide (LPS). Our findings demonstrated that ALDH2 attenuated LPS-induced brain endothelial barrier damage, as evidenced by reduced brain water content and Evans blue dye in mice, decreased transepithelial electrical resistance (TEER), and increased fluorescein isothiocyanate-dextran (FITC-Dextran) leakage in bEnd.3 cells. Furthermore, ALDH2 reduced the levels of reactive oxygen species (ROS) and malondialdehyde (MDA), while enhancing the activities of superoxide dismutase (SOD) and catalase (CAT). ALDH2 also decreased 4-HNE content and restored mitochondrial membrane potential and ATP production, promoting a balanced mitochondrial fission and fusion. Notably, our use of the mitochondrial fission inhibitor Mdivi-1 confirmed that ALDH2 alleviated mitochondrial damage by inhibiting dynamin-related protein 1 (Drp1). Consequently, our findings suggest that the effects of ALDH2 on LPS-induced blood-brain barrier (BBB) damage and oxidative stress may alleviate SAE by inhibiting Drp1 to maintain mitochondrial homeostasis.

miR142 silencing alleviates retinal inflammation by impairing mitochondrial function and reprogramming metabolism of CD4+ T cells via targeting MTFR1

BACKGROUND

Autoimmune uveitis is a sight-threatening inflammatory disease of the retina. MicroRNA-142 (miR-142) has been implicated in its pathogenesis. This study aimed to elucidate the role of miR-142 in uveitis and its underlying mechanisms.

METHODS

The expression of miR-142-3p was analyzed in peripheral blood mononuclear cells from uveitis patients and in experimental autoimmune uveitis (EAU) models. With EAU induction for 14 days, clinical and histopathological scores were graded to evaluate the retinal inflammation. To investigate the effects of miR-142 deficiency on uveitis development, the miR-142 knockout (miR-142-/-) mouse model was used. The miR-142-/- T cell phenotype and function were characterized using flow cytometry and single-cell sequencing for both in vivo and in vitro experiments. The Seahorse Analyzer, mitochondrial staining and electron microscope analysis were conducted to reveal the mitochondrial function and morphology. And then Luciferase Assays and Western-Blot analysis were used to explore the target of miR-142.

RESULTS

We found that miR-142-3p was significantly up-regulated in uveitis and that its deletion in mice prevented EAU development. The T cell isolated from miR-142-/- mice lose its uveitogenic nature. T cell lacking miR-142 exhibited reduced numbers and attenuated pathogenicity in uveitis, characterized by decreased proliferation, increased apoptosis, and abnormal differentiation. Single-cell sequencing, energy metabolism analysis and flow cytometry analysis unveiled metabolic reprogramming in miR-142-/- T cells, with a distinct shift toward glycolysis and restrained oxidative phosphorylation. Further investigation revealed mitochondrial fission regulator 1 (MTFR1) as a direct target of miR-142. The over-expressed protein of MTFR1 in CD4+ T cells was found in miR-142-/- mice.

CONCLUSIONS

Our findings highlight the indispensable role of miR-142 in maintaining T cell mitochondrial function. By modulating MTFR1, miR-142 orchestrates mitochondrial homeostasis, metabolic alterations, apoptosis susceptibility, and proliferation capacity in T cells, thereby influencing susceptibility to autoimmune uveitis.

PFOS causes lysosomes-regulated mitochondrial fission through TRPML1-VDAC1 and oligomerization of MCU/ATP5J2

Perfluorooctane sulfonate (PFOS), a listed persistent organic pollutant, poses risks to human health and is closely linked to chronic metabolic diseases. Although the role of mitochondrial fission in these diseases has garnered attention, whether and how PFOS induces mitochondrial fission remains obscure. Here, we found that PFOS induced mitochondrial fission, as demonstrated by the fragmentation of mitochondria and the upregulation of dynamin-related protein 1 (DRP1), phospho-DRP1 and mitochondrial fission protein 1 (FIS1) in human hepatocytes MIHA and mice liver. Blocking the calcium transfer from lysosomes to mitochondria that was executed by transient receptor potential mucolipin 1 (TRPML1) of lysosomes and voltage-dependent anion channel 1 (VDAC1) of mitochondria, did not affect PFOS-induced mitochondrial fission. In contrast, knockdown of TRPML1 or VDAC1 reversed this process. Knockdown of mitochondrial calcium uniporter (MCU), rather than inhibiting its activity, effectively alleviated PFOS-induced mitochondrial fission. Additionally, PFOS increased MCU oligomers without affecting MCU monomer. Inhibiting autophagy reversed the MCU oligomerization. Further investigation unveiled the interactions of MCU with VDAC1, TRPML1, mitochondrial Fo complex subunit F2 (ATP5J2) and DRP1 in PFOS-exposed mice liver and MIHA cells. We also discovered that knockdown of ATP5J2 alleviated PFOS-induced mitochondrial fission. Ulteriorly, PFOS upregulated ATP5J2 that underwent oligomerization. Knockdown of MCU reversed the increase in ATP5J2. Our study uncovers the presence and molecular basics of lysosomes-regulated mitochondrial fission under PFOS exposure, explains the regulatory pathways on MCU and ATP5J2 oligomerization and their pivotal roles in mitochondrial fission, highlighting the involvement of mitochondrial fission in PFOS-related health risks.

Donafenib Induces Mitochondrial Dysfunction in Liver Cancer Cells via DRP1

Hepatocellular carcinoma (HCC) represents a significant global health challenge, characterized by a high incidence rate. Mitochondria have emerged as an important therapeutic target for HCC. Donafenib, a multi-receptor tyrosine kinase inhibitor, has been approved for the treatment of advanced HCC. However, the underlying mechanisms remain to be elucidated. In this study, we aim to investigate the effects of Donafenib on mitochondrial function in HCC cells. Firstly, we show that Donafenib induces mitochondrial oxidative stress in SNU-449 liver cancer cells by increasing mitochondrial ROS while reducing glutathione peroxidase (GPx) activity and the expression of Mn-SOD. We also demonstrate that Donafenib decreases mitochondrial membrane potential (MMP) and induces the opening of the mitochondrial permeability transition pore (mPTP). Furthermore, Donafenib reduces mitochondrial respiratory rate, COX IV activity, and ATP production. Notably, Donafenib induces mitochondrial fragmentation and reduces mitochondrial length by increasing the expression of DRP1, without affecting Mfn1 or Mfn2. Silencing of DRP1 protects against mitochondrial dysfunction induced by Donafenib, indicating that DRP1 plays a key role in mediating Donafenib's effects on mitochondrial function in HCC cells.

Topological cues of microparticles train stem cells for tissue repair via mechanotransduction

Microspheres (MPs) and porous microspheres (PMPs) are the two most widely used microparticles in tissue engineering and stem cell therapy. However, how stem cells perceive the topological differences between them to regulate cell function remains to be unclear. Here, we systematically studied the changes in stem cell function under the action of MPs and PMPs and elucidated the related mechanisms. Our findings show that the porous structure of PMPs can be sensed by focal adhesions (FAs), which triggers the synthesis of F-actin to inhibit the phosphorylation and degradation of Yes-associated protein (YAP), while also transmitting stress to the nucleus through the contraction of F-actin, thereby enhancing the nuclear translocation of YAP protein. The activation of YAP significantly enhances the proliferation, osteogenesis, paracrine and glucose metabolism of BMSCs, making them exhibit stronger bone repair ability in both in vivo and in vitro experiments. In summary, this study provides a comprehensive and reliable understanding of the behavior of BMSCs in response to MPs and PMPs. It also deepens our understanding of the association between microparticles' topological cues and biological functions, which will provide valuable guidance for the construction of bone tissue engineering (BTE) scaffolds.

Role of Mitochondrial Dysfunctions in Neurodegenerative Disorders: Advances in Mitochondrial Biology

Mitochondria, essential organelles responsible for cellular energy production, emerge as a key factor in the pathogenesis of neurodegenerative disorders. This review explores advancements in mitochondrial biology studies that highlight the pivotal connection between mitochondrial dysfunctions and neurological conditions such as Alzheimer's, Parkinson's, Huntington's, ischemic stroke, and vascular dementia. Mitochondrial DNA mutations, impaired dynamics, and disruptions in the ETC contribute to compromised energy production and heightened oxidative stress. These factors, in turn, lead to neuronal damage and cell death. Recent research has unveiled potential therapeutic strategies targeting mitochondrial dysfunction, including mitochondria targeted therapies and antioxidants. Furthermore, the identification of reliable biomarkers for assessing mitochondrial dysfunction opens new avenues for early diagnosis and monitoring of disease progression. By delving into these advancements, this review underscores the significance of understanding mitochondrial biology in unraveling the mechanisms underlying neurodegenerative disorders. It lays the groundwork for developing targeted treatments to combat these devastating neurological conditions.

Targeting BMP4 as a therapeutic strategy for neovascularization and fibrosis in age-related macular degeneration

This study investigates the role of bone morphogenetic protein-4 (BMP4) in age-related macular degeneration (AMD), with a focus on its effects on subretinal fibrosis and choroidal neovascularization (CNV). Using a mouse model of laser-induced CNV, we found that BMP4 expression was significantly elevated in CNV lesions. BMP4 was shown to promote fibroblast proliferation and their differentiation into myofibroblasts, as indicated by increased expression of α-smooth muscle actin (α-SMA). Additionally, BMP4 promoted the transition of endothelial progenitor cells (EPCs) into endothelial cells (ECs), a process that was modulated by mitochondrial function. Intravitreal administration of Noggin, a BMP4 inhibitor, significantly reduced CNV lesion volume and decreased the expression of CD31 and α-SMA, suggesting a decrease in neovascularization and fibrosis. These findings underscore BMP4's critical role in AMD pathogenesis by driving both angiogenesis and fibrosis. Targeting BMP4 with Noggin presents a promising therapeutic approach for AMD, addressing both neovascularization and fibrosis in a single intervention, and highlights BMP4 as a potential novel target for AMD therapy.

Role of mitochondrial membrane homeostasis in the occurrence of programmed cell death during pollen cryopreservation: Mitochondrial ROS eruption and bioenergetic deficiency as key contributors

Cryopreservation is an ideal approach for the long-term storage of pollen, but the decline in pollen viability caused by necrosis and programmed cell death (PCD) after cryopreservation remains a challenge. Mitochondrial homeostasis is considered to play a crucial role in plant PCD. However, there is no further explanation on how it specifically alters. To investigate changes in mitochondrial reactive oxygen species (ROS) signaling, membrane homeostasis, and bioenergetics during PCD occurrence triggered by cryopreservation, pollen from three Paeonia lactiflora cultivars with decreased, stable, and increased PCD (i.e., 'Yan Zi Xiang Yang', DEC-PCD, 'Fen Yu Nu', STABLE-PCD, 'Zi Feng Chao Yang', INC-PCD) after cryopreservation was used. The results revealed that: (1) Mitochondrial ROS acts as a signaling molecule induced PCD during pollen cryopreservation, and its content was associated with changes in the activity of mitochondrial respiratory chain (MRC) complex I, II and III. (2) After cryopreservation, the extent of mitochondrial permeability transition pore opening, the reduction in mitochondrial membrane potential, and the oxidation of mitochondrial inner membrane in INC-PCD were 16.57 %,50.91 %, and 615.32 % higher, respectively, than those in STABLE-PCD, indicating more severe mitochondrial membrane damage in INC-PCD. (3) During pollen cryopreservation, mitochondrial bioenergetic supply gradually declined as PCD intensified. These results demonstrated that cryopreservation induces excessive mitochondrial ROS production in certain cultivars, leading to the imbalance in mitochondrial membrane homeostasis and impaired bioenergetic supply, ultimately resulting in the occurrence of PCD during pollen cryopreservation of P. lactiflora.

Membrane biomimetic nanoenzyme-incorporated hybrid glycyrrhizic acid hydrogel for precise mitochondrial ROS scavenging for osteoarthritis treatment

Osteoarthritis (OA) is a progressive degenerative disorder which severely threatens the quality of life of older individuals. OA progression is closely related to heightened levels of mitochondrial reactive oxygen species (mtROS). Although nanozymes have a good ROS-scavenging effect, they cannot precisely scavenge mtROS because of the immune rejection of cell membranes, lysosomal escape, and the inability of conventional nanozymes to directly target mitochondria. Dual-target nanozymes were engineered to precisely scavenge mtROS in chondrocytes. We used chondrocyte membrane-camouflaged TPP-modified hollow Prussian blue nanozymes and subsequently encapsulated these nanozymes in a hybrid glycyrrhizic acid hydrogel. The therapeutic efficacy and underlying mechanisms were assessed in vitro and in vivo. The novel nanozymes enhanced cell selectivity, immune evasion capabilities, and mitochondrial targeting. The dual-targeted nanozymes exerted a pronounced therapeutic impact on inflammatory chondrocytes, mitigated mtDNA leakage by precisely scavenging mtROS, dampened cGAS-STING-NF-κB signaling, and enhanced chondrocyte function. The hybrid hydrogels also exhibited improved therapeutic outcomes. We confirmed the beneficial effects of the nanozyme-hydrogel combination on OA progression in mice. The nanozyme-hydrogel combination can reduce precisely scavenge mtROS in chondrocytes, avoiding the leakage of mtDNA and suppressing the cGAS-STING-NF-κB signaling pathway, thereby decreasing inflammatory responses and alleviate OA progression.

Nuclear Genome-Encoded Mitochondrial OXPHOS Complex I Genes in Female Buffalo Show Tissue-Specific Differences

Buffalo physiology intricately balances energy, profoundly influencing health, productivity, and reproduction. This study explores nuclear-mitochondrial crosstalk, revealing OXPHOS Complex I gene expression variations in buffalo tissues through high-throughput RNA sequencing. Unveiling tissue-specific disparities, the research elucidates the genomic landscape of crucial energy production genes, with broader implications for veterinary and agricultural progress. Post-slaughter, tissues from post-pubertal female buffaloes underwent meticulous processing and RNA extraction using the TRIzol method. RNA-Seq library preparation and IlluminaHiSeq 2500 sequencing were performed on QC-passed samples. Data underwent stringent filtration, mapping to the Bubalus bubalis genome using HISAT2. DESeq2 facilitated differential expression gene (DEG) analysis focusing on 57 Mitocarta 3-derived genes associated with OXPHOS complex I. Nuclear-encoded mitochondrial protein transcripts of OXPHOS complex 1 exhibited tissue-specific variations, with 51 genes expressing significantly across tissues. DEG analysis emphasized tissue-specific expression patterns, highlighting a balanced OXPHOS complex I subunit expression in the kidney vs. brain. Gene Ontology (GO) enrichment showcased mitochondria-centric terms, revealing distinct proton motive force-driven mitochondrial ATP synthesis regulation. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses emphasized Thermogenesis and OXPHOS pathways, enriching our understanding of tissue-specific energy metabolism. Noteworthy up-regulation of NDUFB10 in the heart and kidney aligned with heightened metabolic activity. Brain-specific up-regulation of NDUFAF6 indicated a focus on mitochondrial function, while variations in NDUFA11 and ACAD9 underscored pivotal roles in the heart and kidney. GO and KEGG analyses highlighted tissue-specific mitochondrial ATP synthesis and NADH dehydrogenase processes, providing molecular insights into organ-specific metabolic demands and regulatory mechanisms. Our study unveils conserved and tissue-specific nuances in nuclear-encoded mitochondrial OXPHOS complex I genes, laying a foundation for understanding diverse energy demands and potential health implications.

Is SIRT3 and Mitochondria a Reliable Target for Parkinson's Disease and Aging? A Narrative Review

Aging is a complicated degenerative process that has been thoroughly researched in a variety of taxa, including mammals, worms, yeast, and flies. One important controller of organismal lifetime is the conserved deacetylase protein known as silencing information regulator 2 (SIR2). It has been demonstrated that overexpressing SIR2 lengthens the life span in worms, flies, and yeast, demonstrating its function in enhancing longevity. SIRT3 is a member of the sirtuin protein family, identified as a major regulator of longevity and aging. Sirtuin 3 (SIRT3), a possible mitochondrial tumor suppressor, has been explicitly linked to the control of cellular reactive oxygen species (ROS) levels, the Warburg effect, and carcinogenesis. SIRT3 plays a significant part in neurodegenerative illnesses such as Parkinson's and Alzheimer's disease by decreasing the oxidative stress in mitochondria and reducing the ROS levels. Furthermore, SIRT3 has been linked to metabolic and cardiovascular disorders, indicating its wider role in the pathophysiology of disease and possible therapeutic applications.

Formin INF2 supplementation alleviates cytoskeleton-based mitochondria defects for oocyte quality under obesity

Obesity is one main cause of reproductive disorders in female, and oocytes show meiotic maturation defects under obesity, which leads to infertility. However, the molecular characterization for the obese oocytes remains largely unclear. Inverted-formin 2 (INF2) is a formin family member which is involved in actin-based multiple cellular events including vesicle transport and oxidative stress-induced apoptosis. In present study, we reported that INF2 deficiency linked with declined oocyte quality of obesity. Our results showed that INF2 expression decreased in the oocytes of obese mice. INF2 deficiency caused the failure of polar body extrusion and induced large polar bodies. We showed that INF2 depletion disturbed mitochondrial distribution and function, which might be due to the association with mitochondria fission factor DRP1. INF2 co-localized with cytoplasmic actin and its depletion reduced actin polymerization, which further caused the failure of spindle migration in both mouse and porcine oocytes. In addition, we also found that INF2 interacted with HDAC6 and further affected tubulin acetylation for microtubule stability, which disturbed mitochondrial transport. Exogenous INF2 mRNA supplement rescued the meiotic maturation defects of oocytes from obese mice. Thus, our study demonstrated that INF2 is responsible for both mouse and porcine oocyte maturation through its regulation on actin polymerization and tubulin acetylation for mitochondrial function, and its deficiency might be one cause for obesity-induced oocyte defects.

Mitochondria: An overview of their origin, genome, architecture, and dynamics

Mitochondria are traditionally viewed as the powerhouses of eukaryotic cells, i.e., the main providers of the metabolic energy required to maintain their viability and function. However, the role of these ubiquitous intracellular organelles far extends energy generation, encompassing a large suite of functions, which they can adjust to changing physiological conditions. These functions rely on a sophisticated membrane system and complex molecular machineries, most of which imported from the cytosol through intricate transport systems. In turn, mitochondrial plasticity is rooted on mitochondrial biogenesis, mitophagy, fusion, fission, and movement. Dealing with all these aspects and terminology can be daunting for newcomers to the field of mitochondria, even for those with a background in biological sciences. The aim of the present educational article, which is part of a special issue entitled "Mitochondria in aging, cancer and cell death", is to present these organelles in a simple and concise way. Complex molecular mechanisms are deliberately omitted, as their inclusion would defeat the stated purpose of the article. Also, considering the wide scope of the article, coverage of each topic is necessarily limited, with the reader directed to excellent reviews, in which the different topics are discussed in greater depth than is possible here. In addition, the multiple cell type-specific genotypic and phenotypic differences between mitochondria are largely ignored, focusing instead on the characteristics shared by most of them, with an emphasis on mitochondria from higher eukaryotes. Also ignored are highly degenerate mitochondrion-related organelles, found in various anaerobic microbial eukaryotes lacking canonical mitochondria.

Split genetically encoded calcium indicators for interorganellar junctions

Genetically encoded calcium indicators (GECIs) have revolutionized the study of cellular calcium signaling, offering powerful tools for real-time optical monitoring of calcium dynamics. Although contemporary GECIs can be targeted to various organelles, there are no means to obtain active and functional GECIs exclusively at interorganellar junctions. To address this gap, we have developed a toolbox of split versions of green and red GECIs designed to reassemble only when the two "halves" come into proximity. We developed split probes to investigate interorganellar connectivity and activity between mitochondria and the ER (via split-MEGIC) or between the plasma membrane and the ER (via split-sf-MEMBER). We employ the various split-sensors to image neural Ca2+ activity in vitro and in vivo and, in the process, identify Mito-ER junctions and calcium activity within individual dendritic spines by use of split-MEGIC.

Bifunctional Nanostarch against Neuronal Apoptosis via Mitochondria Protection for Ameliorating Ischemic Stroke Injury and Promoting Long-Term Neurological Recovery

Mitochondrial damage occurs as an initial event following ischemic onset, and the extent of mitochondrial dysfunction is highly correlated to the severity of ischemia-induced cell death. Once appropriate therapeutic interventions are provided, the ischemic tissue can be salvaged, which is of great significance in achieving better neurological outcomes. Herein, we developed a nanosized starch as a targeting nanoplatform, featuring effective blood-brain barrier (BBB) penetration through lactoferrin-mediated transcytosis. Notably, the nanostarch-based delivery of Mdivi-1 and Alda-1 enables controlled release in the acidic lysosome of neurons, effectively inhibiting the pathological mitochondrial fission and metabolizing toxic aldehydes, thereby creating protective effects on maintaining mitochondrial function. Moreover, we demonstrated that mitochondrial protection induces a transition from activated pro-death responses to a pro-survival state by reducing the release of pro-apoptotic proteins, significantly contributing to the long-term recovery of neurological function. Overall, our nanostarch provided an in-depth understanding of the delivery of mitochondrial protectants and underscored the potential and utility of mitochondrial protection for ischemic stroke via minimizing neuronal apoptosis.

Agent-based modeling of neuronal mitochondrial dynamics using intrinsic variables of individual mitochondria

Mitochondrial networks undergo remodeling to regulate form and function. The dynamic nature of mitochondria is maintained by the dueling processes of mitochondrial fission and fusion. Dysfunctional mitochondrial dynamics have been linked to debilitating diseases and injuries, suggesting mitochondrial dynamics as a promising therapeutic target. Increasing our understanding of the factors influencing mitochondrial dynamics will help inform therapeutic development. Utilizing live imaging of primary neurons, we analyzed how intrinsic properties of individual mitochondria influence their behavior. We found that size, shape, mitochondrial membrane potential, and protein oxidation predict mitochondrial fission and fusion. We constructed an agent-based model of mitochondrial dynamics, the mitochondrial dynamics simulation (MiDyS). In silico experiments of neuronal ischemia/reperfusion injury and antioxidant treatment illustrate the utility of MiDyS for testing hypothesized mechanisms of injury progression and evaluating therapeutic strategies. We present MiDyS as a framework for leveraging in silico experimentation to inform and improve the design of therapeutic trials.

NSD1 mutation status determines metabolic inhibitor sensitivity in head and neck squamous cell carcinomas by regulating mitochondrial respiration

Head and neck squamous cell carcinomas (HNSCCs) are the most common malignant tumors in the head and neck region, characterized by a high recurrence rate and early metastasis. Despite advances in treatment, patient outcomes and prognosis remain poor, highlighting the urgent need for new therapeutic strategies. Recent research has increasingly focused on targeting glucose metabolism as a therapeutic strategy for cancer, revealing multiple promising targets and potential drugs. However, the metabolic heterogeneity among tumors leads to variable sensitivity to metabolic inhibitors in different patients, limiting their clinical utility. In this study, we employed bioinformatics analysis, cell experiments, animal models, and multi-omics approaches to reveal differences in glucose metabolism phenotypes among HNSCC patients and elucidated the underlying molecular mechanisms driving these differences. Our findings showed that NSD1 mutation status affects the glucose metabolism phenotype in HNSCC, with NSD1 wild-type HNSCC exhibiting higher mitochondrial respiration and NSD1 mutant HNSCC showing weaker mitochondrial respiration but enhanced glycolysis. We further demonstrated that NSD1 regulates mitochondrial respiration in HNSCC via epigenetic modulation of the TGFB2/PPARGC1A signaling axis. Additionally, we found that NSD1 wild-type HNSCC is more sensitive to mitochondrial respiration inhibitors, whereas NSD1 mutant HNSCC shows increased sensitivity to glycolysis inhibitors. In summary, we found that NSD1 can epigenetically regulate the TGFB2/PPARGC1A axis to modulate mitochondrial respiration and sensitivity to metabolic inhibitors in HNSCC. These findings suggest a novel strategy for selecting metabolic inhibitors for HNSCC based on the NSD1 gene status of patients. © 2025 The Pathological Society of Great Britain and Ireland.

Role of macrophage ATP metabolism disorder in SiO2‑induced pulmonary fibrosis: a review

Silicosis, a chronic lung disease, results from prolonged inhalation of silica dust (SiO2) in occupational environments, and its pathogenesis remains incompletely elucidated. Studies have shown that alveolar macrophages (AMs) play a pivotal role in its development. These AMs phagocytose the inhaled SiO2, which leads to morphological, structural, and functional abnormalities that result in lung fibrosis. During this process, adenosine triphosphate (ATP) not only provides energy for the physiological and pathological activities but also acts as a key intracellular and extracellular signaling molecule and regulates cytokine synthesis and secretion. This complex process has not been systematically summarized. In this study, first, the current data on ATP metabolism in the development of SiO2-induced pulmonary fibrosis are introduced. ATP metabolism disorder, caused by impaired production, utilization, or distribution of ATP, disrupts macrophage energy homeostasis. Then, how ATP metabolism disorder affects macrophage morphology and function and the inflammatory and fibrotic processes of the lungs by activating the P2X7 receptor-mediated ATP signaling pathway are discussed. Finally, current therapeutic strategies targeting ATP metabolism disorder and ATP signaling pathways in silicosis are summarized. In conclusion, SiO2-induced ATP metabolism disorder indirectly accelerates the progression of silicosis fibrosis.

Research progress on sepsis-associated encephalopathy by inhibiting pyroptosis

Sepsis is a life-threatening condition characterized by multiple organ dysfunction syndrome resulted from dysregulated host responses to infection. Sepsis-associated encephalopathy (SAE) is one of the most common symptoms of acute-phase sepsis, with nearly 70 % of patients with sepsis ultimately developing SAE. Pyroptosis represents a type of cell death that is initiated by inflammation. This cell death type is associated with various infectious and noninfectious diseases. The gasdermin family proteins are crucial cell death executors and critical components in regulating the canonical pyroptosis pathway in microglia. In this review, we summarize the inhibitory effects of several drugs and genes on the pyroptosis pathway. Our findings suggest that several drugs (puerarin, VX765, HC067047, dexpramipexole, and Danhong injection), erbin gene, and TRIM45 knockdown improve SAE by suppressing the canonical pathway of NLRP3/caspase-1/gasdermin D-mediated pyroptosis. Therefore, they have significant importance in terms of brain protection. Moreover, we review the relevant literature published in recent years and summarize the research status and development prospects in this field to provide a basis for subsequent related research.

Endocrine Dysfunction in Primary Mitochondrial Diseases

Primary mitochondrial disorders (PMD) are genetic disorders affecting the structure or function of the mitochondrion. Mitochondrial functions are diverse, including energy production, ion homeostasis, reactive oxygen species regulation, antioxidant defense, and biosynthetic responsibilities, notably including steroidogenesis. Mitochondria provide the energy to drive intracellular production and extracellular secretion of all hormones. The understanding of the endocrine consequences of PMD is key to timely identification of both endocrine complications in PMD patients, and PMD presenting primarily with endocrine disease. This is a narrative review on the endocrine manifestations of PMD, underlying disease mechanisms, and current and emerging approaches to diagnosing and treating these complex disorders. Diabetes is the most frequent endocrine manifestation of PMD, but growth hormone deficiency, adrenal insufficiency, hypogonadism, and parathyroid dysfunction may occur. Despite the intricate involvement of the thyroid gland in metabolic regulation, there is little evidence for a causal relationship between thyroid dysfunction and PMD. In conclusion, endocrine dysfunction is observed in PMD with varying incidence depending on the specific mitochondrial disorder and the endocrine organ in question. Diagnosis of PMD in a patient with endocrine-presenting features requires a high level of clinical suspicion, particularly when apparently unrelated comorbidities co-exist. Similarly, endocrine pathology may be subtle in patients with known PMD, and thorough consideration must be given to ensure timely diagnosis and treatment. The scope for novel therapeutics for this group of devastating conditions is enormous; however, several challenges remain to be overcome before hopes of curative treatments can be brought into clinical practice.

Defective PINK1-dependent mitophagy is involved in high glucose-induced neurotoxicity

Neuropathic pain often complicates diabetes progression, yet the pathogenic mechanisms are poorly understood. Defective mitophagy is linked to various diabetic complications like nephropathy, cardiomyopathy, and retinopathy. To investigate the molecular basis of hyperglycemia-induced painful diabetic neuropathy (PDN), we examined the effect of high glucose on the PTEN-induced kinase 1 (PINK1)/Parkin RBR E3 ubiquitin protein ligase (Parkin)-mediated mitophagy pathway in ND7/23 cells. Cells were treated with different glucose concentrations (25, 50, 75 mM) for various durations (24, 48, 72 h). Additionally, cells were exposed to high glucose (50 mM) with or without 100 nM rapamycin (a mitophagy enhancer) for 48 h, or transfected with PINK1 siRNA. We assessed protein levels of mitophagy-related genes (PINK1, Parkin, P62, LC3B) and apoptotic markers (cleaved-Caspase3) via Western blotting. High glucose significantly reduced the expression of autophagy-related proteins PINK1 and Parkin in a time- and concentration-dependent manner compared to controls. Rapamycin counteracted the inhibitory effects of high glucose on PINK1/Parkin-mediated mitophagy, while PINK1 siRNA transfection showed similar outcomes, confirming the inhibitory impact of high glucose on mitophagy. Moreover, high glucose induced apoptosis by suppressing PINK1/Parkin-mediated mitophagy, causing cytotoxic effects in ND7/23 cells which is derived from the fusion of mouse neuroblastoma cells and rat dorsal root ganglion (DRG) cells. Our findings suggest that hyperglycemia-induced disruption of the PINK1/Parkin mitophagy pathway impairs mitochondrial homeostasis, leading to apoptosis. Therefore, targeting PINK1 pathway activation or restoring mitophagy might be a promising therapeutic strategy for PDN treatment.

TMBIM-2 orchestrates systemic mitochondrial stress response via facilitating Ca2+ oscillations

Neuronal mitochondrial function is critical for orchestrating inter-tissue communication essential for overall fitness. Despite its significance, the molecular mechanism underlying the impact of prolonged mitochondrial stresses on neuronal activity and how they orchestrate metabolism and aging remains elusive. Here, we identified the evolutionarily conserved transmembrane protein XBX-6/TMBIM-2 as a key mediator in the neuronal-to-intestinal mitochondrial unfolded protein response (UPRmt). Our investigations reveal that intrinsic neuronal mitochondrial stress triggers spatiotemporal Ca2+ oscillations in a TMBIM-2-dependent manner through the Ca2+ efflux pump MCA-3. Notably, persistent Ca2+ oscillations at synapses of ADF neurons are critical for facilitating serotonin release and the subsequent activation of the neuronal-to-intestinal UPRmt. TMBIM2 expression diminishes with age; however, its overexpression counteracts the age-related decline in aversive learning behavior and extends the lifespan of Caenorhabditis elegans. These findings underscore the intricate integration of chronic neuronal mitochondrial stress into neurotransmission processes via TMBIM-2-dependent Ca2+ equilibrium, driving metabolic adaptation and behavioral changes for the regulation of aging.

MSCs in Acute Kidney Injury Treatment: Modulating Mitochondrial Function and Inhibiting Pyroptosis via PGC-1α

OBJECTIVE

This study aims to investigate the mechanisms of MSC therapy for acute kidney injury, focusing on the regulation of mitochondrial function and pyroptosis in renal tubular epithelial cells (RTECs).

METHODS

An in vivo ischemia/reperfusion (I/R) model was used to assess the effects of MSC treatment on mitochondrial membrane potential, mitochondrial function, cell pyroptosis, and PGC-1α expression in RTECs.

RESULTS

MSCs significantly improved mitochondrial function in RTECs by upregulating PGC-1α expression, regulating mitochondrial fusion and fission proteins, reducing mitochondrial ROS production, and suppressing NLRP3 inflammasome activation. Furthermore, MSC treatment reduced the levels of pyroptotic markers, such as IL-18, and exhibited a marked anti-fibrotic effect in the long-term. These findings suggest that MSCs not only repair acute kidney injury but also offer long-term protection against fibrosis.

CONCLUSION

MSCs improve the repair of acute kidney injury by modulating mitochondrial function and inhibiting pyroptosis, providing new theoretical support for MSC-based therapies in AKI treatment.

Sestrin2 is a central regulator of mitochondrial stress responses in disease and aging

Mitochondria supply most of the energy for cellular functions and coordinate numerous cellular pathways. Their dynamic nature allows them to adjust to stress and cellular metabolic demands, thus ensuring the preservation of cellular homeostasis. Loss of normal mitochondrial function compromises cell survival and has been implicated in the development of many diseases and in aging. Although exposure to continuous or severe stress has adverse effects on cells, mild mitochondrial stress enhances mitochondrial function and potentially extends health span through mitochondrial adaptive responses. Over the past few decades, sestrin2 (SESN2) has emerged as a pivotal regulator of stress responses. For instance, SESN2 responds to genotoxic, oxidative, and metabolic stress, promoting cellular defense against stress-associated damage. Here, we focus on recent findings that establish SESN2 as an orchestrator of mitochondrial stress adaptation, which is supported by its involvement in the integrated stress response, mitochondrial biogenesis, and mitophagy. Additionally, we discuss the integral role of SESN2 in mediating the health benefits of exercise as well as its impact on skeletal muscle, liver and heart injury, and aging.

Retroviral foamy virus gag induces parkin-dependent mitophagy

BACKGROUND

Prototype foamy virus (PFV) is a complex retrovirus that can maintain latent infection for life after viral infection of the host. However, the mechanism of latent infection with PFV remains unclear. Our previous studies have shown that PFV promotes autophagy flux, but whether PFV causes mitophagy remains unclear.

RESULTS

In this study, we demonstrated that PFV infection damages mitochondria, increases mitochondria reactive oxygen species (mtROS) production, and induces mitophagy in a time-dependent manner. Further investigation revealed that PFV Gag is a crucial protein responsible for triggering mitophagy. The overexpression of Gag leads to mitochondrial damage and stimulates mitophagy in a dose-dependent manner. Additionally, overexpression of Gag activates the PINK1-Parkin signaling pathway, while the knockdown of Parkin inhibits Gag-induced mitophagy. Furthermore, Rab5a was significantly upregulated in cells overexpressed Gag, and the inhibition of Rab5a reversed the effects of Gag-induced mitophagy.

CONCLUSIONS

Our data suggested that PFV can induce mitophagy and Gag induces Parkin-dependent mitophagy by upregulating Rab5a. These findings not only enhance a better understanding of the foamy virus infection mechanisms but also provide critical insights into novel virus-host cell interactions.

Cardioprotective effects of Dendrobium officinale polysaccharides on thiacloprid-induced cardiac injury via modulating mitochondrial dynamics

Thiacloprid (THI), a widely used neonicotinoid pesticide, has been shown to induce cardiac injury, though the underlying mechanisms remain poorly understood. Dendrobium officinale polysaccharides (DOP), a bioactive compound with potent antioxidant properties, may offer protection against such toxicity. This study investigated the cardioprotective effects of DOP in THI-induced cardiac injury in quails, with a particular focus on the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. Network pharmacology analysis identified key targets of DOP, linking them to oxidative stress, mitochondrial dysfunction, and inflammatory pathways. Experimental results demonstrated that DOP significantly reversed THI-induced hematological and biochemical abnormalities, including the restoration of cardiac biomarkers and mitigation of myocardial structural damage. DOP treatment notably activated the Nrf2 pathway, leading to the upregulation of antioxidant enzymes such as heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO1), which countered THI-induced oxidative stress. Additionally, DOP restored mitochondrial dynamics by balancing mitochondrial fission and fusion proteins. These findings highlight the central role of Nrf2 activation in the cardioprotective effects of DOP, suggesting that DOP may serve as a promising therapeutic agent for mitigating pesticide-induced cardiovascular toxicity.

Mitochondrial and peroxisomal fission in cortical neurogenesis

The human brain is unique in its cellular diversity, intricate cytoarchitecture, function, and complex metabolic and bioenergetic demands, for which mitochondria and peroxisomes are essential. Mitochondria are multifunctional organelles that coordinate various signaling pathways central to neurogenesis. The dynamic morphological changes of the mitochondrial network have been linked to the regulation of bioenergetic and metabolic states. Specific protein machinery is dedicated to mitochondrial fission and fusion, allowing organelle distribution during cell division, organelle repair, and adaptation to environmental stimuli (excellent reviews have been published on these topics [Kondadi and Reichert, 2024; Giacomello et al., 2020; Tilokani et al., 2018; Kraus et al., 2021; Navaratnarajah et al., 2021]). In parallel, peroxisomes contain over 50 different enzymes which regulate metabolic functions that are critical for neurogenesis (Berger et al., 2016; Hulshagen et al., 2008). Peroxisomes share many of the components of their fission machinery with the mitochondria and undergo fission to help meet metabolic demands in response to environmental stimuli (Schrader et al., 2016). This review focuses primarily on the machinery involved in mitochondrial and peroxisomal fission. Mitochondrial fission has been identified as a critical determinant of cell fate decisions (Iwata et al., 2023, 2020; Khacho et al., 2016; King et al., 2021; Prigione and Adjaye, 2010; Vantaggiato et al., 2019; Kraus et al., 2021). The connection between alterations in peroxisomal fission and metabolic changes associated with cellular differentiation remains less clear. Here, we provide an overview of the functional and regulatory aspects of the mitochondrial and peroxisomal fission machinery and provide insight into the current mechanistic understanding by which mitochondrial and peroxisomal fission influence neurogenesis.

Endogenous interactomes of MFN1 and MFN2 provide novel insights into interorganelle communication and autophagy

MFN1 (mitofusin 1) and MFN2 are key players in mitochondrial fusion, endoplasmic reticulum (ER)-mitochondria juxtaposition, and macroautophagy/autophagy. However, the mechanisms by which these proteins participate in these processes are poorly understood. Here, we studied the interactomes of these two proteins by using CRISPR-Cas9 technology to insert an HA-tag at the C terminus of MFN1 and MFN2, and thus generating HeLa cell lines that endogenously expressed MFN1-HA or MFN2-HA. HA-affinity isolation followed by mass spectrometry identified potential interactors of MFN1 and MFN2. A substantial proportion of interactors were common for MFN1 and MFN2 and were regulated by nutrient deprivation. We validated novel ER and endosomal partners of MFN1 and/or MFN2 with a potential role in interorganelle communication. We characterized RAB5C (RAB5C, member RAS oncogene family) as an endosomal modulator of mitochondrial homeostasis, and SLC27A2 (solute carrier family 27 (fatty acid transporter), member 2) as a novel partner of MFN2 relevant in autophagy. We conclude that MFN proteins participate in nutrient-modulated pathways involved in organelle communication and autophagy.Abbreviations: ACTB: actin, beta; ATG2: autophagy related 2; ATG5: autophagy related 5; ATG12: autophagy related 12; ATG14: autophagy related 14; ATG16L1: autophagy related 16 like 1; Baf A1: bafilomycin A1; BECN1: beclin 1, autophagy related; BFDR: Bayesian false discovery rate; Cas9: CRISPR-associated endonuclease Cas9; CRISPR: clustered regularly interspaced short palindromic repeats; DNM1L/DRP1: dynamin 1-like; ER: endoplasmic reticulum; Faa1: fatty acid activation 1; FC: fold change; FDR: false discovery rate; FIS1: fission, mitochondrial 1; GABARAP: gamma-aminobutyric acid receptor associated protein; GABARAPL2: GABA type A receptor associated protein like 2; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HA: hemagglutinin; KO: knockout; LIR: LC3-interacting region; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MARCHF5: membrane associated ring-CH-type finger 5; MDVs: mitochondria-derived vesicles; MFN1: mitofusin 1; MFN2: mitofusin 2; NDFIP2: Nedd4 family interacting protein 2; OMM: outer mitochondrial membrane; OPA1: OPA1, mitochondrial dynamin like GTPase; OXPHOS: oxidative phosphorylation; PE: phosphatidylethanolamine; PINK1: PTEN induced putative kinase 1; PS: phosphatidylserine; RAB5C: RAB5C, member RAS oncogene family; S100A8: S100 calcium binding protein A8 (calgranulin A); S100A9: S100 calcium binding protein A9 (calgranulin B); SLC27A2: solute carrier family 27 (fatty acid transporter), member 2; TIMM44: translocase of inner mitochondrial membrane 44; TOMM20: translocase of outer mitochondrial membrane 20; ULK1: unc-51 like kinase 1; VCL: vinculin; VDAC1: voltage-dependent anion channel 1; WT: wild type.

Procyanidins inhibit alphacoronavirus infection by reducing interferon antagonism

BACKGROUND

The development of coronavirus drugs has primarily focused on targeting viral components, such as RNA-dependent RNA polymerase (RdRP), with relatively little attention given to enhancing host antiviral defenses. α-Coronaviruses, including human-infecting HCoV-NL63 and HCoV-229E, utilize immune evasion strategies such as suppressing host interferon production to establish infection. Procyanidins (PC), oligomeric compounds composed of catechin and epicatechin, have demonstrated the ability to stimulate host interferon synthesis, potentially counteracting this immune evasion. Exploring the inhibitory effects of PC specifically on α-coronaviruses offers a promising avenue for developing novel therapeutic strategies that bolster host immunity against these pathogens.

PURPOSE

This study aims to evaluate the inhibitory effects of PC on α-coronaviruses using different cell models and investigate whether its antiviral activity is linked to enhanced interferon production. By examining PC's effects on selected α-coronaviruses, this research explores its potential as a therapeutic strategy against human-infecting HCoV-NL63 and HCoV-229E, which evade innate immunity.

METHODS

Vero cells, human embryonic kidney 293T (HEK-293T) cells, and intestinal porcine epithelial-J2 (IPEC-J2) cells were used as cell models, with porcine epidemic diarrhea virus (PEDV) serving as the α-coronavirus infection model. The inhibitory effects of PC on the α-coronaviruses and its activation of interferon were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot (WB). Co-immunoprecipitation (co-IP) was used to assess how PC impacts the degradation of Retinoic acid-inducible gene I (RIG-I) and TANK-binding kinase 1 (TBK1) by coronavirus N protein. Confocal microscopy was utilized to observe the recovery of mitochondrial morphology disrupted by coronavirus, and flow cytometry analyses were conducted.

RESULTS

Viral cycle and time-of-addition analyses showed that PC inhibited PEDV infection during both the replication and release stages of the virus. Simultaneously, in the early stages of infection, PC countered PEDV's evasion of interferon by elevating host interferon levels. Co-immunoprecipitation experiments confirmed that this effect was achieved by reducing the binding of coronavirus N protein to key proteins in the interferon synthesis pathway, RIG-I and TBK1, a mechanism previously identified as one of the main reasons for interferon evasion by α-coronavirus N protein. Additionally, intriguingly, we observed that PC has the ability to restore excessive mitochondrial fission induced by coronaviruses, an effect achieved by reducing the binding of coronavirus N protein to mitochondrial fusion protein 1 (MFN1). This observation suggests potential mechanistic pathways through which PC impacts mitochondrial antiviral-related proteins. These results suggest that PC may also inhibit human α-coronaviruses, such as HCoV-NL63 and HCoV-229E, by utilizing similar antiviral mechanisms. This provides valuable insights into potential therapeutic strategies for treating human coronaviruses.

CONCLUSIONS

These results suggest that PC may inhibit α-coronavirus infection by reversing the virus's antagonistic effects on interferon. These findings provide a new perspective for exploring therapeutic mechanisms against coronaviruses like HCoV-NL63, HCoV-229E, SARS-CoV-2, SARS-CoV, and MERS-CoV, which can evade host innate immunity, including the identification of new drug targets.

Oxidative stress and mitochondrial dysfunctions induced by cyanobacterial microcystin-LR in primary grass carp hepatocytes

Microcystin-LR (MC-LR), a cyclic heptapeptide produced by freshwater cyanobacteria, induces a range of liver injuries. However, the mechanisms underlying MC-LR toxicity in primary hepatocytes of aquatic organisms remains poorly understood. In this study, we investigated the effects of MC-LR on oxidative stress and mitochondrial function using primarily cultured grass carp hepatocytes. The results revealed that IC50 of MC-LR on grass carp primary liver cells for 24 hours was 2.40 μmol/L. Based on 24h-IC50, concentrations of 0, 0.30, 0.60, and 1.20 μmol/L were used in subsequent experiments. MC-LR exposure led to a significant reduction in cell viability, induced abnormal cell morphology, and caused plasma membrane rupture, as indicated by elevated LDH activity in a concentration-dependent manner. Additionally, MC-LR exposure induced oxidative stress, resulting in increased ROS levels and downregulation of genes associated with oxidative stress, including keap1, nrf2, cat, sod1, gpx, gst, and gr (P<0.05). Furthermore, the electron microscopy results showed that MC-LR caused damage to the ultrastructure of primary hepatocytes, including mitochondrial membrane rupture, vacuolation, and induction of mitochondrial autophagy. Moreover, MC-LR exposure elevated intracellular Ca2+ concentration, reduced MMP and ATP levels, and inhibited mitochondrial respiratory chain complex I activity (P<0.05). qRT-PCR analysis demonstrated that MC-LR treatment significantly decreased the transcriptional levels of genes related to mitochondrial quality control including pgc-1α, tfam, nrf1, drp1, opa1, mfn1, and mfn2 (P<0.05). Collectively, our findings highlight that MC-LR causes oxidative stress and impairs mitochondrial function, leading to further hepatocyte damage, which provides insights into the mechanisms of MC-LR-induced hepatotoxicity and offers valuable references for further investigations.

Foxp3 confers long-term efficacy of chimeric antigen receptor-T cells via metabolic reprogramming

The tumor microenvironment, characterized by low oxygen tension and scarce nutrients, impairs chimeric antigen receptor (CAR)-T cell metabolism, leading to T cell exhaustion and dysfunction. Notably, Foxp3 confers a metabolic advantage to regulatory T cells under such restrictive conditions. Exploiting this property, we generated CAR-TFoxp3 cells by co-expressing Foxp3 with a third-generation CAR construct. The CAR-TFoxp3 cells exhibited distinct metabolic reprogramming, marked by downregulated aerobic glycolysis and oxidative phosphorylation coupled with upregulated lipid metabolism. This metabolic shift was driven by Foxp3's interaction with dynamin-related protein 1. Crucially, CAR-TFoxp3 cells did not acquire regulatory T cell immunosuppressive functions but instead demonstrated enhanced antitumor potency and reduced expression of exhaustion markers via Foxp3-mediated adaptation. The potent antitumor effect and absence of immunosuppression were confirmed in a humanized immune system mouse model. Our findings establish a metabolic reprogramming-based strategy to enhance CAR-T cell adaptability within the hostile tumor microenvironment while preserving therapeutic efficacy.

Irisin attenuates cardiac injury and improves prognosis in rats with hemorrhagic shock by maintaining mitochondrial homeostasis via the AMPK/Drp1 pathway

Objective

Hemorrhagic shock (HS) is a critical clinical condition in which cardiac dysfunction and failure are leading causes of mortality. Mitochondrial dysfunction is central to the pathogenesis of cardiac dysfunction in HS. Irisin has been shown to improve mitochondrial function and protect against ischemia-reperfusion injury (IRI), but its specific effects on myocardial injury in HS are unknown. This study investigates irisin's therapeutic potential in a rat model of HS.

Methods

For in vivo studies, a rat HS model was established via controlled blood withdrawal and Animals were allocated to four groups: Sham, HS, HS + Vehicle (HS + Veh), and HS + Irisin. Physiological responses were evaluated through temporal sampling at 1, 3, and 6 h post-HS. For in vitro studies, H9c2 cardiomyocytes were exposed to oxygen-glucose deprivation to establish a hypoxic model. Cells were categorized into six groups: normoxia (N), normoxia + AMPK inhibitor compound C (N + Cc), hypoxia (H), hypoxia + Cc (H + Cc), hypoxia + irisin (H + Irisin), and hypoxia + Cc + irisin (H + Cc + Irisin). Cellular functional outcomes were analyzed following 3-h hypoxia exposure.

Results

HS significantly reduced serum irisin levels. Exogenous irisin administration enhanced survival rates, stabilized mean arterial pressure (MAP), lowered lactate (LAC) levels, improved cardiac structure and function, and reduced myocardial injury biomarkers in HS rats. Mechanistically, irisin activated AMP-activated protein kinase (AMPK) and Sirtuin 1(SIRT1), to suppress the expression of dynamin-related protein 1 (Drp1) and fission protein 1 (Fis1), while upregulating mitofusin 1 (Mfn1). This modulation of mitochondrial dynamics preserved cardiomyocyte mitochondrial membrane potential (MMP), ATP production, and structural integrity. Hypoxic H9c2 cardiomyocytes exhibited consistent results. To confirm AMPK/Drp1-dependent mechanisms, Cc was administered to inhibit irisin-induced AMPK activation. Cc abolished irisin's suppression of Drp1/Fis1 and its Mfn1 upregulation. Furthermore, Cc eliminated irisin-mediated protection in both H9c2 cardiomyocytes and mitochondria.

Conclusion

Our study demonstrates that irisin ameliorates cardiac function and enhances early prognosis in HS. These cardioprotective effects are achieved through attenuation of myocardial damage and SIRT1/AMPK/Drp1 pathway-dependent restoration of mitochondrial homeostasis.

Advances in research on mitochondrial dysfunction in neurodegenerative diseases

Given the high energy demand of the nervous system, mitochondrial dysfunction is a key factor in the pathogenesis of neurodegenerative diseases. Thus, a comprehensive understanding of its mechanisms and potential therapeutic targets is essential. This review discusses the roles of mitochondrial oxidative stress, mitochondrial dynamics alterations, and mtDNA damage in Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and multiple sclerosis (MS). In addition, it summarizes the contributions of novel technological approaches in detecting mitochondrial dysfunction, which assist in disease diagnosis. We also emphasize emerging therapeutic strategies and drugs aimed at enhancing mitochondrial quality control and reducing oxidative stress, thereby laying the groundwork for innovative therapeutic approaches in neurodegenerative disease treatment.

Secoiridoid-enriched extra virgin olive oil extracts enhance mitochondrial activity and antioxidant response in colorectal cancer cells: The role of Oleacein and Oleocanthal in PPARγ interaction

The secoiridoid-enriched fraction of extra virgin olive oil (EVOO) provides significant health benefits, but its underlying mechanisms have not been fully elucidated. To investigate this, we analyzed the transcriptome of HCT116 colorectal cancer cells treated with secoiridoid-enriched EVOO extracts using bioinformatic tools and identified differentially expressed genes enriched in mitochondrial pathways. In vitro validation showed increased mitochondrial mass and DNA driven by enhanced biogenesis and fusion events, accompanied by higher mitochondrial respiration and ATP production. The resulting increase in reactive oxygen species (ROS) triggered a cellular response involving AMPK, NRF2, and antioxidant genes, along with PGC-1α, a master regulator of mitochondrial metabolism. To correlate the biological effects with the components of the secoiridoid-enriched EVOO extracts, we focused on Oleacein (OL) and Oleocanthal (OC). Molecular docking and dynamics simulations predicted both compounds bind to peroxisome proliferator-activated receptor gamma (PPARγ) as partial agonists, with OL exhibiting stronger affinity. Treatments with isolated OL and OC mostly replicated the results of the whole extracts. Mechanistically, we provided evidence of the crucial role played by PPARγ as the effects on the pathways analyzed were reduced by either blocking the receptor with an irreversible inhibitor and silencing the PPARG gene with specific siRNAs. This study reveals the AMPK-PGC-1α-PPARγ axis as a key regulator of OL and OC's effects on mitochondrial function and antioxidant response, supporting their potential as nutraceuticals for health promotion and opening avenues for developing novel PPARγ modulators to complement existing therapeutic strategies.

TOM20-driven E3 ligase recruitment regulates mitochondrial dynamics through PLD6

Mitochondrial homeostasis is maintained through complex regulatory mechanisms, including the balance of mitochondrial dynamics involving fusion and fission processes. A central player in this regulation is the ubiquitin-proteasome system (UPS), which controls the degradation of pivotal mitochondrial proteins. In this study, we identified cullin-RING E3 ligase 2 (CRL2) and its substrate receptor, FEM1B, as critical regulators of mitochondrial dynamics. Through proteomic analysis, we demonstrate here that FEM1B controls the turnover of PLD6, a key regulator of mitochondrial dynamics. Using structural and biochemical approaches, we show that FEM1B physically interacts with PLD6 and that this interaction is facilitated by the direct association of FEM1B with the mitochondrial import receptor TOM20. Ablation of FEM1B or disruption of the FEM1B-TOM20 interaction impairs PLD6 degradation and induces mitochondrial defects, phenocopying PLD6 overexpression. These findings underscore the importance of FEM1B in maintaining mitochondrial morphology and provide further mechanistic insights into how the UPS regulates mitochondrial homeostasis.

Correlation of organelle interactions in the development of non-alcoholic fatty liver disease

Organelles, despite having distinct functions, interact with each other. Interactions between organelles typically occur at membrane contact sites (MCSs) to maintain cellular homeostasis, allowing the exchange of metabolites and other pieces of information required for normal cellular physiology. Imbalances in organelle interactions may lead to various pathological processes. Increasing evidence suggests that abnormalorganelle interactions contribute to the pathogenesis of non-alcoholic fatty liver disease (NAFLD). However, the key role of organelle interactions in NAFLD has not been fully evaluated and researched. In this review, we summarize the role of organelle interactions in NAFLD and emphasize their correlation with cellular calcium homeostasis, lipid transport, and mitochondrial dynamics.

Leptin attenuates diabetic cardiomyopathy-induced cardiac remodeling via regulating cGAS/STING signaling and Opa1-mediated mitochondrial fusion

PURPOSE

This investigation seeks to elucidate the contribution of leptin to the pathogenesis of diabetic cardiomyopathy (DCM).

METHODS

Mice were rendered diabetic through the administration of streptozotocin (STZ). Leptin was delivered via subcutaneously implanted osmotic pumps. Assessments of cardiac performance, hypertrophy, and fibrosis were conducted using echocardiography, Hematoxylin and Eosin (H&E), Wheat Germ Agglutinin (WGA), and Masson trichrome staining. Myocardial apoptosis and oxidative stress were quantified through TUNEL assay and biochemical markers of oxidative stress, including Malondialdehyde (MDA), 4-Hydroxynonenal (4-HNE), and 3-Nitrotyrosine (3NT). Mitochondrial structure was examined using Transmission Electron Microscopy (TEM). Primary neonatal cardiomyocytes were subjected to high glucose (HG) conditions. The fluorescent indicators MitoTracker Green and MitoSOX Red were employed to evaluate mitochondrial morphology and function within the cardiomyocytes.

RESULTS

Mice with diabetes displayed marked cardiac hypertrophy and fibrosis, as indicated by H&E, WGA, and Masson staining. The administration of leptin significantly mitigated the cardiac pathological manifestations in diabetic mice. Leptin increased the expression of Opa1 and enhanced mitochondrial fusion and function in cardiomyocytes exposed to HG. The cGAS/STING signaling pathway may serve as a pivotal intermediary for leptin to facilitate Opa1-driven mitochondrial fusion.

CONCLUSIONS

Leptin appears to safeguard against hyperglycemia-induced mitochondrial oxidative damage and DCM by modulating the cGAS/STING signaling cascade and Opa1-mediated mitochondrial fusion. These results propose that leptin could be a promising agent for promoting mitochondrial fusion and preventing diabetes-associated cardiac pathologies.

Mitochondria in focus: From structure and function to their role in human diseases. A review

Mitochondria, double-membraned organelles within all eukaryotic cells, are essential for the proper functioning of the human organism. The frequently used phrase "powerhouses of the cell" fails to adequately capture their multifaceted roles. In addition to producing energy in the form of adenosine triphosphate through oxidative phosphorylation, mitochondria are also involved in apoptosis (programmed cell death), calcium regulation, and signaling through reactive oxygen species. Recent research suggests that they can communicate with one another and influence cellular processes. Impaired mitochondrial function on the one hand, can have widespread and profound effects on cellular and organismal health, contributing to various diseases and age-related conditions. Regular exercise on the other hand, promotes mitochondrial health by enhancing their volume, density, and functionality. Although research has made significant progress in the last few decades, mainly through the use of modern technologies, there is still a need to intensify research efforts in this field. Exploring new approaches to enhance mitochondrial health could potentially impact longevity. In this review, we focus on mitochondrial research and discoveries, examine the structure and diverse roles of mitochondria in the human body, explore their influence on energy metabolism and cellular signaling and emphasize their importance in maintaining overall health.

Massage-Mimicking Nanosheets Mechanically Reorganize Inter-organelle Contacts to Restore Mitochondrial Functions in Parkinson's Disease

Parkinson's disease (PD) is exacerbated by dysfunction of inter-organelle contact, which depends on cellular responses to the mechanical microenvironment and can be regulated by external mechanical forces. Delivering dynamic mechanical forces to neural cells proves challenging due to the skull. Inspired by the effects of massage; here PEGylated black phosphorus nanosheets (PEG-BPNS), known for their excellent biocompatibility, biodegradability, specific surface area, mechanical strength, and flexibility, are introduced, which are capable of adhering to neural cell membrane and generating mechanical stimulation with their lateral size of 200 nm, exhibiting therapeutic potential in a 1-methyl-4-phenyl-1,2,3,6-te-trahydropyridine-induced PD mouse model by regulating inter-organelle contacts. Specifically, it is found that 200 nm PEG-BPNS, acting as "NanoMassage," significantly increase  plasma membrane tension, as evidenced by fluorescent lipid tension reporter fluorescence lifetime analysis. This mechanical force modulates actin reorganization, subsequently regulating the contacts between actin, mitochondria, and endoplasmic reticulum, further controlling mitochondrial fission and mitigating mitochondrial dysfunction in PD, exhibiting therapeutic efficacy via intranasal administration. These findings provide a noninvasive strategy for applying mechanical stimulation to deep brain areas and elucidate the mechanism of NanoMassage mediating inter-organelle contacts, suggesting the rational design of "NanoMassage" to remodel inter-organelle communications in neurodegenerative disease treatment.

Mitochondrial dysfunction in AMI: mechanisms and therapeutic perspectives

Acute myocardial infarction (AMI) and the myocardial ischemia-reperfusion injury (MI/RI) that typically ensues represent a significant global health burden, accounting for a considerable number of deaths and disabilities. In the context of AMI, percutaneous coronary intervention (PCI) is the preferred treatment option for reducing acute ischemic damage to the heart. Despite the modernity of PCI therapy, pathological damage to cardiomyocytes due to MI/RI remains an important target for intervention that affects the long-term prognosis of patients. In recent years, mitochondrial dysfunction during AMI has been increasingly recognized as a critical factor in cardiomyocyte death. Damaged mitochondria play an active role in the formation of an inflammatory environment by triggering key signaling pathways, including those mediated by cyclic GMP-AMP synthase, NOD-like receptors and Toll-like receptors. This review emphasizes the dual role of mitochondria as both contributors to and regulators of inflammation. The aim is to explore the complex mechanisms of mitochondrial dysfunction in AMI and its profound impact on immune dysregulation. Specific interventions including mitochondrial-targeted antioxidants, membrane-stabilizing peptides, and mitochondrial transplantation therapies have demonstrated efficacy in preclinical AMI models.

Mitochondrial classic metabolism and its often-underappreciated facets

For many decades, mitochondria were essentially regarded as the main providers of the adenosine triphosphate (ATP) required to maintain the viability and function of eukaryotic cells, thus the widely popular metaphor "powerhouses of the cell". Besides ATP generation - via intermediary metabolism - these intracellular organelles have also traditionally been known, albeit to a lesser degree, for their notable role in biosynthesis, both as generators of biosynthetic intermediates and/or as the sites of biosynthesis. From the 1990s onwards, the concept of mitochondria as passive organelles providing the rest of the cell, from which they were otherwise isolated, with ATP and biomolecules on an on-demand basis has been challenged by a series of paradigm-shifting discoveries. Namely, it was shown that mitochondria act as signaling effectors to upregulate ATP generation in response to growth-promoting stimuli and are actively engaged, through signaling and epigenetics, in the regulation of a plethora of cellular processes, ultimately deciding cell function and fate. With the focus of mitochondrial research increasingly placed in these "non-classical" functions, the centrality of mitochondrial intermediary metabolism to other mitochondrial functions tends to be overlooked. In this article, we revisit mitochondrial intermediary metabolism and illustrate how its intermediates, by-products and molecular machinery underpin other mitochondrial functions. A certain emphasis is given to frequently overlooked mitochondrial functions, namely the biosynthesis of iron-sulfur (Fe-S) clusters, the only known function shared by all mitochondria and mitochondrion-related organelles. The generation of reactive oxygen species (ROS) and their putative role in signaling is also discussed in detail.

Mitochondrial Responses to Conventional and Ultra-high Dose Rate (FLASH) Radiation

Purpose

Ultra-high dose rate (>40 Gy/s, FLASH) radiation therapy (RT) provides equivalent tumor control while reducing normal tissue toxicity relative to conventional dose rate (CONV) RT. However, the mechanisms underlying the observed FLASH effect are unknown. We hypothesized that the preservation of mitochondrial integrity in nontumorigenic cells by FLASH RT could be a key factor in reducing normal tissue toxicity and improving overall treatment outcomes.

Methods

We examined mitochondrial health and function after CONV and FLASH in vitro, ex vivo, and in vivo through assays of metabolic flux, mitochondrial membrane potential, mitochondrial reactive oxygen species (ROS), mitochondrial DNA damage and copy number, mitochondrial morphology, and tumor growth and survival.

Results

In in vitro assays, murine pancreatic cancer (PDAC) cells showed evidence of equal mitochondrial damage in response to CONV and FLASH, but nontumorigenic pancreatic cells were spared by FLASH. These results were recapitulated ex vivo, and mice treated with FLASH showed higher response rates and longer survival time than mice treated with CONV in an in vivo tumor model.

Conclusions

Collectively, these results suggest that FLASH spares mitochondrial function in nontumorigenic cells, but not in PDAC cells, relative to CONV. The preservation of mitochondrial integrity in nontumorigenic cells may be a key mechanism underlying the reduced normal tissue toxicity observed with FLASH RT.

Mitochondrial Changes Induced by SGLT2i in Lymphocytes from Diabetic Kidney Transplant Recipients: A Pilot Study

Sodium-glucose co-transporter 2 inhibitors (SGLT2i) preserve cardiac and renal function by mechanisms that are not completely elucidated. Among other things, SGLT2i promote nutrient-deprivation signalling, which might affect the immune function. As the fate of immune cells is controlled by their metabolism, we aimed to study the mitochondrial integrity of lymphocytes isolated from renal transplant recipients with type 2 diabetes (T2D) upon SGLT2i therapy instauration and six-month follow up. In this real-world pilot study, the mitochondrial respiration of isolated peripheral blood mononuclear cells was monitored in a Seahorse XFp extracellular-flux analyzer and cells were photographed with a confocal microscope. Mitochondrial mass, membrane potential, and superoxide content of lymphocyte subpopulations were measured by flow cytometry (MitoTrackerTM Green, TMRM, and MitoSOXTM Red probes). Leveraging in vivo conditions of immune cells, we evaluated their metabolic profiles associated with immune activation. Herein, we identified changes in redox homeostasis with sustained membrane polarization, and an increased mitochondrial biogenesis upon PHA stimulation that significantly correlated with changes in body weight and LDL-cholesterol levels, and a resultant compensatory mitochondrial function of lymphocytes. Our data suggest novel mechanisms induced by SGLT2i to modulate immune cells, which probably underlie the observed beneficial effects in kidney transplant recipients. Nonetheless, further mechanistic studies are required to extend these exploratory findings and encourage the use of this therapeutic strategy.

HBimmCue: A Versatile Fluorescent Probe for Multi-Scale Imaging of Lipid Polarity and Membrane Order in Inner Mitochondrial Membrane

Mitochondrial membrane environmental dynamics are crucial for understanding function, yet high-resolution observation remains challenging. Here, HBimmCue is introduced as a fluorescent probe localized to inner mitochondrial membrane (IMM) that reports lipid polarity and membrane order changes, which correlate with cellular respiration levels. Using HBimmCue and fluorescence lifetime imaging microscopy (FLIM), IMM lipid heterogeneity is uncovered across scales, from nanoscale structures within individual mitochondria to mouse pre-implantation embryos. At the sub-organelle level, stimulated emission depletion (STED)-FLIM imaging highlights nanoscale polarity variations within the IMM. At the sub-cellular and cellular level, reduced IMM lipid polarity is observed in damaged mitochondria marked for lysosomal degradation and distinct IMM lipid distributions are identified in neurons and disease models. Additionally, metabolic dysfunction associated with oocytes aging and metabolic reprogramming from zygote to blastocyst is detected. Together, the work demonstrates the broad applicability of HBimmCue, offering a new paradigm for investigating lipid polarity and respiration level at multiple scales.

Three's company: Membrane waltz among organelles

The study of membrane contact sites (MCS) has profoundly transformed our understanding of inter-organelle communication. These sites, where the membranes of two organelles are closely apposed, facilitate the transfer of small molecules such as lipids and ions. They are especially crucial for the maintenance of the structure and function of organelles like mitochondria and lipid droplets, which are largely excluded from vesicular trafficking. The significant advancements in imaging techniques, and molecular and cell biology research have shown that MCS are more complex than what originally thought and can involve more than two organelles. This has revealed the intricate nature and critical importance of these subcellular connections. Here, we provide an overview of newly described three-way inter-organelles associations, and the proteins involved in these MCS. We highlight the roles these contacts play in key cellular processes such as lipid droplet biogenesis and mitochondrial division. Additionally, we discuss the latest advances in super-resolution imaging that enable the study of these complex three-way interactions. Ongoing research, driven by technological innovations, promises to uncover further insights into their roles in fundamental cellular processes and their implications for health and disease.