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Acute myeloid leukemia (AML) cells are highly dependent on oxidative phosphorylation and the mitochondrial dynamics regulated by fusion-related genes MFN1, MFN2, and OPA1 and fission-related genes DNM1L and MFF. An analysis of previously published gene expression datasets showed that high expression of MFF was significantly associated with poor prognosis in patients with AML. Based on this finding, we investigated the impact of mitochondrial dynamics in AML. Transduction of shRNA against fission-related genes, DNM1L and MFF, inhibited growth and increased the mitochondrial area in AML cell lines. Extracellular flux analysis showed that deletion of mitochondrial dynamic regulators reduced mitochondrial respiration without significantly affecting glycolysis, except in shDNM1L-transfected cells. Immunodeficient NOG mice transplanted with DNM1L- or MFF-knockdown AML cells survived significantly longer than controls. Treatment of AML cell lines with Mdivi-1, which inhibits the DRP1 encoded by DNM1L, inhibited cell proliferation and oxidative phosphorylation. Our results show that mitochondrial dynamics play an important role in AML, and provide novel biological insights. The inhibition of mitochondrial dynamics induces unique mitochondrial alterations, which may be explored as a potential therapeutic target in AML. [ABSTRACT FROM AUTHOR]

Sepsis-associated organ dysfunction plays a critical role in its high mortality, mainly in connection with mitochondrial dysfunction. Whether the inhibition of mitochondrial fission is beneficial to sepsis-related organ dysfunction and underlying mechanisms are unknown. Cecal ligation and puncture induced sepsis in rats and dynamic related protein 1 knockout mice, lipopolysaccharide-treated vascular smooth muscle cells and cardiomyocytes, were used to explore the effects of inhibition of mitochondrial fission and specific mechanisms. Our study showed that mitochondrial fission inhibitor Mdivi-1 could antagonize sepsisinduced organ dysfunction including heart, vascular smooth muscle, liver, kidney, and intestinal functions, and prolonged animal survival. The further study showed that mitochondrial functions such as mitochondrial membrane potential, adenosinetriphosphate contents, reactive oxygen species, superoxide dismutase and malonaldehyde were recovered after Mdivi-1 administration via improving mitochondrial morphology. And sepsis-induced inflammation and apoptosis in heart and vascular smooth muscle were alleviated through inhibition of mitochondrial fission and mitochondrial function improvement. The parameter trends in lipopolysaccharidestimulated cardiomyocytes and vascular smooth muscle cells were similar in vivo. Dynamic related protein 1 knockout preserved sepsis-induced organ dysfunction, and the animal survival was prolonged. Taken together, this finding provides a novel effective candidate therapy for severe sepsis/septic shock and other critical clinical diseases. [ABSTRACT FROM AUTHOR]

Aims: Seawater immersion significantly aggravated organ dysfunction following hemorrhagic shock, leading to higher mortality rate. However, the effective treatment is still unavailable in clinic. Mitochondria were involved in the onset and development of multiple organ function disorders; whether mitochondria participate in the cardiac dysfunction following seawater immersion combined with hemorrhagic shock remains poorly understood. Hence, we investigated the role and possible mechanism of mitochondria in seawater immersion combined with hemorrhage shock–induced cardiac dysfunction. Results: Mitochondrial fission protein dynamin-related protein 1 (Drp1) was activated and translocated from the cytoplasm to mitochondria in the heart following seawater immersion combined with hemorrhagic shock, leading to excessive mitochondrial fission. Excessive mitochondrial fission disrupted mitochondrial function and structure and activated mitophagy and apoptosis. At the same time, excessive mitochondrial fission resulted in disturbance of myocardial structure and hemodynamic disorders and ultimately provoked multiple organ dysfunction and high mortality. Further studies showed that the mitochondrial division inhibitor mitochondrial division inhibitor-1 can significantly reverse Drp1 mitochondrial translocation and inhibit mitochondrial fragmentation, reactive oxygen species (ROS) accumulation, mitophagy, and apoptosis and then protect circulation and vital organ functions, prolonging animal survival. Innovation: Our findings indicate that Drp1-mediated mitochondrial fission could be a novel therapeutic targets for the treatment of seawater immersion combined with hemorrhagic shock. Conclusion: Drp1 mitochondrial translocation played an important role in the cardiac dysfunction after seawater immersion combined with hemorrhage shock. Drp1-mediated excessive mitochondrial fission leads to cardiac dysfunction due to the mitochondrial structure and bioenergetics impairment. [ABSTRACT FROM AUTHOR]

Abstract Several human diseases, including cancer and neurodegeneration, are associated with excessive mitochondrial fragmentation. In this context, mitochondrial division inhibitor (Mdivi-1) has been tested as a therapeutic to block the fission-related protein dynamin-like protein-1 (Drp1). Recent studies suggest that Mdivi-1 interferes with mitochondrial bioenergetics and complex I function. Here we show that the molecular mechanism of Mdivi-1 is based on inhibition of complex I at the IQ site. This leads to the destabilization of complex I, impairs the assembly of N- and Q-respirasomes, and is associated with increased ROS production and reduced efficiency of ATP generation. Second, the calcium homeostasis of cells is impaired, which for example affects the electrical activity of neurons. Given the results presented here, a potential therapeutic application of Mdivi-1 is challenging because of its potential impact on synaptic activity. Similar to the Complex I inhibitor rotenone, Mdivi-1 may lead to neurodegenerative effects in the long term.

Abstract Increasing evidence supports the hypothesis that cancer progression is under mitochondrial control. Mitochondrial fission plays a pivotal role in the maintenance of cancer cell homeostasis. The inhibition of DRP1, the main regulator of mitochondrial fission, with the mitochondrial division inhibitor (mdivi-1) had been associated with cancer cell sensitivity to chemotherapeutics and decrease proliferation. Here, using breast cancer cells we find that mdivi-1 induces the detachment of the cells, leading to a bulk of floating cells that conserved their viability. Despite a decrease in their proliferative and clonogenic capabilities, these floating cells maintain the capacity to re-adhere upon re-seeding and retain their migratory and invasive potential. Interestingly, the cell detachment induced by mdivi-1 is independent of DRP1 but relies on inhibition of mitochondrial complex I. Furthermore, mdivi-1 induces cell detachment rely on glucose and the pentose phosphate pathway. Our data evidence a novel DRP1-independent effect of mdivi-1 in the attachment of cancer cells. The generation of floating viable cells restricts the use of mdivi-1 as a therapeutic agent and demonstrates that mdivi-1 effect on cancer cells are more complex than anticipated.

CD39 serves as a crucial biomarker for neoantigen-specific CD8+ T cells and is associated with antitumor activity and exhaustion. However, the relationship between CD39 expression levels and the function of chimeric antigen receptor T (CAR-T) cells remains controversial. This study aimed to investigate the role of CD39 in the functional performance of CAR-T cells against hepatocellular carcinoma (HCC) and explore the therapeutic potential of CD39 modulators, such as mitochondrial division inhibitor-1 (mdivi-1), or knockdown CD39 through short hairpin RNA. Our findings demonstrated that glypican-3-CAR-T cells with moderate CD39 expression exhibited a strong antitumor activity, while high and low levels of CD39 led to an impaired cellular function. Methods modulating the proportion of CD39 intermediate (CD39int)-phenotype CAR-T cells such as mdivi-1 and CD39 knockdown enhanced and impaired T cell function, respectively. The combination of mdivi-1 and CD39 knockdown in CAR-T cells yielded the highest proportion of infiltrated CD39int CAR-T cells and demonstrated a robust antitumor activity in vivo. In conclusion, this study revealed the crucial role of CD39 in CAR-T cell function, demonstrated the potential therapeutic efficacy of combining mdivi-1 with CD39 knockdown in HCC, and provided a novel treatment strategy for HCC patients in the field of cellular immunotherapy. [ABSTRACT FROM AUTHOR]

Increasing evidence supports the hypothesis that cancer progression is under mitochondrial control. Mitochondrial fission plays a pivotal role in the maintenance of cancer cell homeostasis. The inhibition of DRP1, the main regulator of mitochondrial fission, with the mitochondrial division inhibitor (mdivi-1) had been associated with cancer cell sensitivity to chemotherapeutics and decrease proliferation. Here, using breast cancer cells we find that mdivi-1 induces the detachment of the cells, leading to a bulk of floating cells that conserved their viability. Despite a decrease in their proliferative and clonogenic capabilities, these floating cells maintain the capacity to re-adhere upon re-seeding and retain their migratory and invasive potential. Interestingly, the cell detachment induced by mdivi-1 is independent of DRP1 but relies on inhibition of mitochondrial complex I. Furthermore, mdivi-1 induces cell detachment rely on glucose and the pentose phosphate pathway. Our data evidence a novel DRP1-independent effect of mdivi-1 in the attachment of cancer cells. The generation of floating viable cells restricts the use of mdivi-1 as a therapeutic agent and demonstrates that mdivi-1 effect on cancer cells are more complex than anticipated. [ABSTRACT FROM AUTHOR]

Objective To investigates the protective effect of mitochondrial division inhibitor, Mdivi-1, on intestinal barrier function in septic rats. Methods A total of 160 SD rats were randomly and equally divided into sham operation group, sepsis group (established by cecal ligation and puncture), conventional treatment group, and Mdivi-1 treatment group. The rats from the conventional treatment group were given lactated Ringer's solution (35 mL/kg) at an infusion rate of 3 mL/h according to the guidelines for sepsis treatment, and those from the Mdivi-1 treatment group were added with intravenous administration of 1 mg/kg Mdivi-1 for resuscitation on the basis of conventional treatment. After 2 h of resuscitation, intestinal barrier function, intestinal expression of zonula occludes-1 (ZO-1), pathological changes in small intestine, serum concentrations of inflammatory cytokines (including TNF-α and IL-1β), mean arterial blood pressure (MAP), survival time and 72-hour survival rate were observed. Intestinal epithelial cells (IECs) were employed to observe the effect of Mdivi-1 on the expression of ZO-1 under the simulation of LPS. Results The septic rats had significantly increased intestinal permeability, D-lactate level and serum concentrations of TNF-α and IL-1β when compared with those of the sham operation group (P < 0.05), and showed intestinal villus rupture, glandular atrophy, and great amount of inflammatory cells in pathological observation. Conventional treatment resulted in slightly decreased serum concentrations of TNF-α and IL-1β, intestinal permeability, and D-lactate level (P>0.05), and mildly improved intestinal villus disturbance when compared with the sepsis group. Mdivi-1 treatment combined with conventional treatment significantly decreased serum concentrations of TNF-α and IL-1β, intestinal permeability, and D-lactate level in comparison with septic rats (P < 0.05), and pathological results showed clear intestinal villus structure and significantly improved inflammatory cell infiltration. The immunohistochemical results of intestinal tissue showed that ruptured tight junction was observed after sepsis, and Mdivi-1 treatment significantly improved the tight junction rupture. At the cellular level, the expression level of ZO-1 between IECs was significantly decreased after LPS stimulation (P < 0.05), and Mdivi-1 treatment increased LPS-induced decrease in ZO-1 expression (P < 0.05). Conclusion Conclusion Mdivi-1 has a protective effect on intestinal barrier function in septic rats, which may be through its regulating ZO-1 expression.

The document is a corrigendum for an article on the protective effects of inhibiting mitochondrial fission on organ function after sepsis. It acknowledges errors in Figures 2 and 3 of the original publication, where images were misused and confirms that these errors do not impact the scientific conclusions of the study. The corrected figures show the effects of Mdivi-1 on vital organ function and mitochondrial morphology in septic rats. The study was conducted by researchers from the State Key Laboratory of Trauma, Burns, and Combined Injury in Chongqing, China. [Extracted from the article]

The following review considers current concepts concerning the characteristics of DRP1-related mitochondrial division in brain cells during hypoxic-ischemic pathology. The functional role of DRP1 in neurons and astroglia in cerebral ischemia conditions was analyzed. We discuss the potential for regulating DRP1 activity through the selective inhibitor of mitochondrial fission, mdivi-1. The article also presents data on DRP1 involvement in astro- and microglia-mediated intercellular mitochondrial transport. Understanding of the molecular mechanisms responsible for mitochondrial fission during hypoxic-ischemic exposure will allow us to consider DRP1 as an effective therapeutic target for treating conditions with a hypoxic component.

AbstractContext Chaihu Shugan San (CHSGS) was effective in the treatment of functional dyspepsia (FD).Objective To investigate the mechanism of CHSGS in FD through dynamin-related protein 1 (Drp-1)-mediated interstitial cells of cajal (ICC) mitophagy.Materials and methods Forty Sprague-Dawley (SD) rats were randomly divided into control, model, mdivi-1, mdivi-1 + CHSGS and CHSGS groups. Tail-clamping stimulation was used to establish the FD model. Mdivi-1 + CHSGS and CHSGS groups were given CHSGS aqueous solution (4.8 g/kg) by gavage twice a day. Mdivi-1 (25 mg/kg) was injected intraperitoneally once every other week for 4 w. Mitochondrial damage was observed by corresponding kits and related protein expressions were assessed by Immunofluorescence and (or) Western Blot.Results Compared with the mean value of the control group, superoxide dismutase (SOD) and citrate synthase (CS) in the model group were decreased by 11% and 35%; malondialdehyde (MDA) and reactive oxygen species (ROS) were increased by 1.2- and 2.8-times; ckit fluorescence and protein expressions were decreased by 85% and 51%, co-localization expression of LC3 and voltage dependent anion channel 1 (VDAC1), Drp-1 and translocase of the outer mitochondrial membrane 20 (Tom20) were increased by 10.1- and 5.4-times; protein expressions of Drp-1, Beclin-1, and LC3 were increased by 0.5-, 1.4-, and 2.5-times whereas p62 was decreased by 43%. After mdivi-1 and (or) CHSGS intervention, the above situation has been improved.Discussion and conclusion CHSGS could improve mitochondrial damage and promote gastric motility in FD rats by regulating Drp-1-mediated ICC mitophagy.

The following review considers current concepts concerning the characteristics of DRP1-related mitochondrial division in brain cells during hypoxic-ischemic pathology. The functional role of DRP1 in neurons and astroglia in cerebral ischemia conditions was analyzed. We discuss the potential for regulating DRP1 activity through the selective inhibitor of mitochondrial fission, mdivi-1. The article also presents data on DRP1 involvement in astro- and microglia-mediated intercellular mitochondrial transport. Understanding of the molecular mechanisms responsible for mitochondrial fission during hypoxic-ischemic exposure will allow us to consider DRP1 as an effective therapeutic target for treating conditions with a hypoxic component. [ABSTRACT FROM AUTHOR]

Abstract Background Inflammation and immune dysfunction with classically activated macrophages(M1) infiltration are important mechanisms in the progression of atherosclerosis (AS). Dynamin-related protein 1 (DRP1)-dependent mitochondrial fission is a novel target for alleviating inflammatory diseases. This study aimed to investigate the effects of DRP1 inhibitor Mdivi-1 on AS. Methods ApoE−/− mice were fed with a high-fat diet supplemented with or without Mdivi-1. RAW264.7 cells were stimulated by ox-LDL, pretreated with or without MCC950, Mito-TEMPO, or Mdivi-1. The burden of plaques and foam cell formation were determined using ORO staining. The blood lipid profles and inflammatory cytokines in serum were detected by commercial kits and ELISA, respectively. The mRNA expression of macrophage polarization markers, activation of NLRP3 and the phosphorylation state of DRP1 were detected. Mitochondrial reactive oxygen species (mito-ROS), mitochondrial staining, ATP level and mitochondrial membrane potential were detected by mito-SOX, MitoTracker, ATP determination kit and JC-1 staining, respectively. Results In vivo, Mdivi-1 reduced the plaque areas, M1 polarization, NLRP3 activation and DRP1 phosphorylation at Ser616. In vitro, oxidized low-density lipoprotein (ox-LDL) triggered M1 polarization, NLRP3 activation and abnormal accumulation of mito-ROS. MCC950 and Mito-TEMPO suppressed M1 polarization mediated foam cell formation. Mito-TEMPO significantly inhibited NLRP3 activation. In addition, Mdivi-1 reduced foam cells by inhibiting M1 polarization. The possible mechanisms responsible for the anti-atherosclerotic effects of Mdivi-1 on reducing M1 polarization were associated with suppressing mito-ROS/NLRP3 pathway by inhibiting DRP1 mediated mitochondrial fission. In vitro, similar results were observed by DRP1 knockdown. Conclusion Inhibition of DRP1-dependent mitochondrial fission by Mdivi-1 alleviated atherogenesis via suppressing mito-ROS/NLRP3-mediated M1 polarization, indicating DRP1-dependent mitochondrial fission as a potential therapeutic target for AS.

Objective: Allergic rhinitis (AR) is a common allergic disorder, afflicting thousands of human beings. Aberrant mitochondrial dynamics are important pathological elements for various immune cell dysfunctions and allergic diseases. However, the connection between mitochondrial dynamics and AR remains poorly understood. This study aimed to determine whether mitochondrial dynamics influence the inflammatory response in AR. Methods: In the present study, we established a murine model of AR by sensitization with ovalbumin (OVA). Then, we investigated the mitochondrial morphology in mice with AR by transmission electron microscopy and confocal fluorescence microscopy, and evaluated the role of Mdivi‐1 (an inhibitor of mitochondrial fission) on allergic symptoms, inflammatory responses, allergic‐related signals, and reactive oxygen species formation. Results: There was a notable enhancement in mitochondrial fragmentation in the nasal mucosa of mice following OVA stimulation, whereas Mdivi‐1 prevented aberrant mitochondrial morphology. Indeed, Mdivi‐1 alleviated the rubbing and sneezing responses in OVA‐sensitized mice. Compared with vehicle‐treated ones, mice treated with Mdivi‐1 exhibited a reduction in interleukin (IL)‐4, IL‐5, and specific IgE levels in both serum and nasal lavage fluid, and shown an amelioration in inflammatory response of nasal mucosa. Meanwhile, Mdivi‐1 treatment was associated with a suppression in JAK2 and STAT6 activation and reactive oxygen species generation, which act as important signaling for allergic response. Conclusion: Our findings reveal mitochondrial dynamics modulate the allergic responses in AR. Mitochondrial dynamics may represent a promising target for the treatment of AR. [ABSTRACT FROM AUTHOR]

Chilodonella hexasticha is a harmful parasitic ciliate that can cause severe damage to fish and high mortalities worldwide. Its congeneric species, C. uncinata, is a facultative parasite that not only can be free-living but also can parasitize on fish gills and fins. In this study, single-cell transcriptomes of these two species were assembled and characterized. Numerous enzymes related to energy metabolism and parasitic adaption were identified through annotation in the Non-Redundant (NR), Clusters of Orthologous Genes (COG), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. The expression of isocitrate dehydrogenase (IDH), cytochrome c oxidase subunit 1 (Cox1) and ATP synthase F1, delta subunit (ATP5D) was up-regulated in C. hexasticha compared with C. uncinata. The oxidative phosphorylation process was also enriched in C. hexasticha. The main mitochondrial metabolic pathways in C. hexasticha were depicted and enzymes related to energy metabolism pathways were compared between these two species. More importantly, mitochondrial division inhibitor 1 (mdivi-1) proved to be very effective in killing both C. hexasticha and C. uncinata, which could be a novel drug for Chilodonellosis control. This study can help us better understand the energy metabolisms of C. hexasticha and C. uncinata and provide new insight into novel targets for chilodonellosis control. Meanwhile, the transcriptome data can also facilitate genomic studies of these two species in the future. [ABSTRACT FROM AUTHOR]

Memory loss, often known as amnesia, is common in the elderly population and refers to forgetting facts and experiences. It is associated with increased mitochondrial fragmentation, though the contribution of mitochondrial dynamics in amnesia is poorly understood. Therefore, the present study is aimed at elucidating the role of Mdivi-1 in mitochondrial dynamics, hippocampal plasticity, and memory during scopolamine (SC)-induced amnesia. The findings imply that Mdivi-1 significantly increased the expression of Arc and BDNF proteins in the hippocampus of SC-induced amnesic mice, validating improved recognition and spatial memory. Moreover, an improved mitochondrial ultrastructure was attributed to a decline in the percentage of fragmented and spherical-shaped mitochondria after Mdivi-1 treatment in SC-induced mice. The significant downregulation of p-Drp1 (S616) protein and upregulation of Mfn2, LC3BI, and LC3BII proteins in Mdivi-1-treated SC-induced mice indicated a decline in fragmented mitochondrial number and healthy mitochondrial dynamics. Mdivi-1 treatment alleviated ROS production and Caspase-3 activity and elevated mitochondrial membrane potential, Vdac1 expression, ATP production, and myelination, resulting in reduced neurodegeneration in SC mice. Furthermore, the decline of pro-apoptotic protein cytochrome-c and increase of anti-apoptotic proteins Procaspase-9 and Bcl-2 in Mdivi-1-treated SC-induced mice suggested improved neuronal health. Mdivi-1 also increased the dendritic arborization and spine density, which was further corroborated by increased expression of synaptophysin and PSD95. In conclusion, the current study suggests that Mdivi-1 treatment improves mitochondrial ultrastructure and function through the regulation of mitochondrial dynamics. These changes further improve neuronal cell density, myelination, dendritic arborization, and spine density, decrease neurodegeneration, and improve recognition and spatial memory. Schematic presentation depicts that Mdivi-1 rescues memory decline in scopolamine-induced amnesic male mice by ameliorating mitochondrial dynamics and hippocampal plasticity [ABSTRACT FROM AUTHOR]

It is found that a hot environment aggravates hemorrhagic shock‐induced internal environment and organ dysfunction. Meanwhile mitochondria show over‐fission. Whether inhibition of mitochondrial fission benefits from the early treatment of hemorrhagic shock under a hot environment is unclear. An uncontrolled hemorrhagic shock model in rats is used, and the effects of mitochondrial fission inhibitor mdivi‐1 on mitochondrial function, organ function, and survival rate of rats are measured. The results show that 0.1–3 mg/kg mdivi‐1 antagonizes hemorrhagic shock‐induced mitochondrial fragment. In addition, mdivi‐1 improves mitochondrial function, and alleviates hemorrhagic shock‐induced oxidative stress and inflammation under a hot environment. Further studies show that 0.1–3 mg/kg Mdivi‐1 reduces blood loss, and maintains a mean artery pressure (MAP) of 50–60 mmHg before bleeding‐stops after hemorrhagic shock, compared with single Lactate Ringer's (LR) resuscitation. Notably, 1 mg/kg of Mdivi‐1 extends the time of hypotensive resuscitation to 2–3 h. During 1 or 2 h of ligation, Mdivi‐1 prolongs survival time and protects vital organ function by rescuing mitochondrial morphology and improving mitochondrial function. These results suggest Mdivi‐1 is suitable for the early treatment of hemorrhagic shock under a hot environment and can extend the golden treatment time to 2–3 hour for hemorrhagic shock under a hot environment. [ABSTRACT FROM AUTHOR]

Background: Inflammation and immune dysfunction with classically activated macrophages(M1) infiltration are important mechanisms in the progression of atherosclerosis (AS). Dynamin-related protein 1 (DRP1)-dependent mitochondrial fission is a novel target for alleviating inflammatory diseases. This study aimed to investigate the effects of DRP1 inhibitor Mdivi-1 on AS. Methods: ApoE−/− mice were fed with a high-fat diet supplemented with or without Mdivi-1. RAW264.7 cells were stimulated by ox-LDL, pretreated with or without MCC950, Mito-TEMPO, or Mdivi-1. The burden of plaques and foam cell formation were determined using ORO staining. The blood lipid profles and inflammatory cytokines in serum were detected by commercial kits and ELISA, respectively. The mRNA expression of macrophage polarization markers, activation of NLRP3 and the phosphorylation state of DRP1 were detected. Mitochondrial reactive oxygen species (mito-ROS), mitochondrial staining, ATP level and mitochondrial membrane potential were detected by mito-SOX, MitoTracker, ATP determination kit and JC-1 staining, respectively. Results: In vivo, Mdivi-1 reduced the plaque areas, M1 polarization, NLRP3 activation and DRP1 phosphorylation at Ser616. In vitro, oxidized low-density lipoprotein (ox-LDL) triggered M1 polarization, NLRP3 activation and abnormal accumulation of mito-ROS. MCC950 and Mito-TEMPO suppressed M1 polarization mediated foam cell formation. Mito-TEMPO significantly inhibited NLRP3 activation. In addition, Mdivi-1 reduced foam cells by inhibiting M1 polarization. The possible mechanisms responsible for the anti-atherosclerotic effects of Mdivi-1 on reducing M1 polarization were associated with suppressing mito-ROS/NLRP3 pathway by inhibiting DRP1 mediated mitochondrial fission. In vitro, similar results were observed by DRP1 knockdown. Conclusion: Inhibition of DRP1-dependent mitochondrial fission by Mdivi-1 alleviated atherogenesis via suppressing mito-ROS/NLRP3-mediated M1 polarization, indicating DRP1-dependent mitochondrial fission as a potential therapeutic target for AS. [ABSTRACT FROM AUTHOR]

Objective To observe the early therapeutic effects of a mitochondrial fission inhibitor, mitochondrial division inhibitor 1 (Mdivi-1), on the traumatic shock rats at high altitude. Methods SD rats were rapidly transported (airlift) from the plain (Chongqing) to the plateau (Lhasa, 3 600 m altitude). After 72 h, the traumatic shock model of rats at high altitude was prepared by free bleeding from splenic artery disconnection until mean arterial pressure (MAP) fell to 40 mmHg. The animals were divided into 5 groups: sham-operation group, shock group, Lactate Ringer's (LR) solution control group, and LR combined with 0.1 and 0.5 mg/kg Mdivi-1 groups. Then the experiments were designed as 2 parts. The rats in the first part were resuscitated with mere LR solution or combined with 0.1 or 0.5 mg/kg Mdivi-1 without hemostatic treatment. With the MAP maintained at 50-60 mmHg, the changes of MAP, bleeding volume, fluid infusion volume and survival rate were observed in each group. In the second part, bleeding control was performed by ligation of the spleen artery after 1 h of low-pressure resuscitation, and definitive resuscitation was continuously given. The changes of blood loss, infusion volume, organ functions, tissue oxygen partial pressure, lung and brain water content and animal survival were subsequently investigated. Results When LR solution was used for low-pressure resuscitation without hemostatic treatment, the MAP of rats was maintained at 50-60 mmHg for about 1 h, and then began to drop gradually rather than rise after increasing the amount of fluid input, with the bleeding volume soared obviously. Whereas Mdivi-1 combination treatment maintained MAP at 50-60 mmHg for about 3 h, and significantly reduced the bleeding volume and fluid infusion. Further studies showed that in the hemostatic resuscitation treatment, the rats of the LR control group still had a rather low level of tissue oxygen partial pressure, with elevated water contents in the lung and brain, and seriously impaired functions of vital organs such as the heart, liver and kidney. However, Mdivi-1 (0.1 or 0.5 mg/kg) treatment remarkably improved the damage, increased the tissue oxygen partial pressure, reduced the water contents in the lung and brain, alleviated the impairment of the heart, liver and kidney, and greatly prolonged the survival time of shock animals. Conclusion Mdivi-1 is suitable for the early treatment of traumatic shock at high altitude, which can improve organ functions and extend the golden time of treatment.

Background: Neuroinflammation is one of the essential pathogeneses of cognitive damage suffering from sepsis-associated encephalopathy (SAE). Lots of evidences showed the microglia presented mitochondrial fragmentation during SAE. This study investigated the protective effects and novel mechanisms of inhibiting microglia mitochondrial fragmentation via mitochondrial division inhibitor 1 (Mdivi-1) on cognitive damage in SAE., Methods: The SAE model was performed by cecal ligation and puncture (CLP), and Mdivi-1 was administrated via intraperitoneal injection. Morris water maze was performed to assess cognitive function. Mitochondrial morphology was observed by electron microscope or MitoTracker staining. The qRT-PCR, immunofluorescence staining, and western blots were used to detect the inflammatory factors and protein content, respectively. Flow cytometry was used to detect the polarization of hippocampal microglia. Bioinformatics analysis was used to verify hypotheses., Results: Mdivi-1 administration alleviated sepsis-induced mitochondrial fragmentation, microglia activation, polarization, and cognitive damage. The mechanisms study showed neuroinflammation and oxidative stress were suppressed via NF-κB and Keap1/Nrf2/HO-1 pathways following Mdivi-1 administration; meanwhile, pyroptosis in microglia was reduced, which was associated with enhanced autophagosome formation via p62 elevation following Mdivi-1 administration., Conclusion: Inhibition of microglia mitochondrial fragmentation is beneficial to SAE cognitive disturbance, the mechanisms are related to alleviating neuroinflammation, oxidative stress, and pyroptosis., (© 2025 The Author(s). CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)

Enhanced glycolysis and elevated lactic acid (LA) production are observed during sudden death syndrome (SDS) in broilers. However, the mechanism underlying LA-induced cardiomyocyte damage and heart failure in fast-growing broilers remains unclear. In this study, chicken embryo cardiomyocytes (CECs) were cultured and treated with LA to investigate LA-induced CEC injury and its mechanism, aiming to develop strategies to prevent LA-induced SDS in broilers. Results showed that LA inhibited CEC proliferation and contraction whereas inducing apoptosis. Furthermore, LA disrupted mitochondrial ultrastructure, reduced mitochondrial membrane potential, activated mitophagy, and disturbed mitochondrial dynamics. Treatment with Mdivi-1, a selective Drp1 inhibitor, improved CEC viability, restored mitochondrial network integrity, reduced reactive oxygen species production, and inhibited LA-induced apoptosis. These findings suggest that LA-induced cardiomyocyte injury during SDS in broilers is associated with mitochondrial damage and increased mitochondrial fission. The inhibition of mitochondrial hyperfission by Mdivi-1 effectively preserves CEC morphology, structure, and function, playing a critical role in preventing LA-induced damage. This study provides a foundation for strategies to prevent and control SDS in broilers., (© 2024 Wiley Periodicals LLC.)

Atherosclerosis, a major contributor to cardiovascular disease, involves lipid accumulation and inflammatory processes in arterial walls, with oxidized low-density lipoprotein (OxLDL) playing a central role. OxLDL is increased during aging and stimulates monocyte transformation into foam cells and induces metabolic reprogramming and pro-inflammatory responses, accelerating atherosclerosis progression and contributing to other age-related diseases. This study investigated the effects of Mdivi-1, a mitochondrial fission inhibitor, and S1QEL, a selective complex I-associated reactive oxygen species (ROS) inhibitor, on OxLDL-induced responses in monocytes. Healthy monocytes isolated from participants were treated with OxLDL, with or without Mdivi-1 or S1QEL, and assessed for metabolic shifts, inflammatory cytokine expression, foam cell formation, and ROS production. OxLDL treatment elevated glycolytic activity (ECAR) and expression of pro-inflammatory cytokines IL1B and CXCL8, promoting foam cell formation and mitochondrial ROS (mtROS) production. Mdivi-1 and S1QEL effectively reduced OxLDL-induced glycolytic reprogramming, inflammatory cytokine levels, and foam cell formation while limiting mtROS. These findings suggest that both Mdivi-1 and S1QEL modulate key monocyte responses to OxLDL, providing insights into potential therapeutic approaches for age-related diseases., Competing Interests: Competing interests The authors declare no competing interests

Objective To observe the protective effect of mdivi-1, a mitochondrial fission inhibitor, on mice after myocardial ischemia. Methods A total of 140 C57 mice were randomly divided into 4 groups (n=35), that is, Sham group, Sham+mdivi-1 group, ischemia group, and mdivi-1 group. Mouse model of acute myocardial ischemia was established by ligating left anterior descending branch in mice. SOD, MDA, ATP, ROS and markers of myocardial injury were measured, and myocardial and mitochorial morphology was observed to study the protective effect of mdivi-1 on the heart of myocardial ischemia mice. Results The mice in the ischemia group showed damaged myocardial structure, more mitochondrial fragmentation, disordered arrangement, and obviously impaired mitochondrial function. While the treatment of mdivi-1 significantly reduced above damaged mitochondrial structure and function in myocardial cells, restored myocardial ATP (1.587±0.227 μmol/mg) and SOD (0.401±0.138 U/mg) contents (P < 0.05), and decreased the production of ROS (4 276.0±687.5 fluorescent intensity/mg) and content of MDA (3.538±1.110 μmol/mg) (P < 0.05), and thus alleviated the oxidative damages in the myocardium, reduced the levels of blood markers of myocardial injury, protected myocardial function, and finally significantly prolonged the survival time and improved the survival rate of myocardial ischemia mice. Conclusion Mitochondrial fission inhibitor mdivi-1 has a protective effect on myocardial ischemia mice.

Hesperidin is one of the main active ingredients of Citrus aurantium L. (Rutaceae) and tangerine peel, which have anti-inflammatory and antioxidant effects. In previous study, we found that gastric motility disorder in functional dyspepsia (FD) rats accompanied by excessive autophagy/mitochondrial swelling and even vacuolization in the interstitial cells of cajal (ICC), but the exact mechanism has not yet been investigated. Therefore, we used different doses of hesperidin (50 mg/kg, 100 mg/kg, and 200 mg/kg) to intervene in FD rats, and found that medium doses of hesperidin (100 mg/kg) significantly increased gastric motility in FD rats. Subsequently, FD rats were randomly divided into control group, model group, mdivi-1 group, mdivi-1+hesperidin group and hesperidin group, and mitochondrial division inhibitor (mdivi-1) was injected intraperitoneally to further investigate whether hesperidin could regulate dynamin-related protein 1 (Drp1)-mediated mitophagy in ICC to improve mitochondrial damage. The results showed that compared with the model group, the serum malondialdehyde (MDA) level decreased and the superoxide dismutase (SOD) level increased in the mdivi-1 and hesperidin groups (p < 0.001). Transmission electron microscopy (TEM) observed that the mitochondrial nuclear membrane was intact in gastric tissues with a clear internal cristae pattern, and autophagy lysosomes were rare. The colocalization expression of microtubule associated protein 1 light chain 3 (LC3) and voltage dependent anion channel 1 (VDAC1), Drp1 and translocase of the outer mitochondrial membrane 20 (Tom20) was significantly decreased (p < 0.001), the protein expression of mitochondrial Drp1, Beclin1 and LC3 were significantly decreased (p < 0.001), the protein expression of mitochondrial P62 and ckit in gastric tissue were significantly increased (p < 0.05, p < 0.001). The above situation was improved more significantly by the synergistic intervention of mdivi-1 and hesperidin. Therefore, hesperidin can improve mitochondrial damage and promote gastric motility in FD rats by regulating Drp1-mediated ICC mitophagy. [ABSTRACT FROM AUTHOR]

Background: Neurological deficits following subarachnoid hemorrhage (SAH) are caused by early or delayed brain injuries. Our previous studies have demonstrated that hyperglycemia induces profound neuronal apoptosis of the cerebral cortex. Morphologically, we found that hyperglycemia exacerbated late vasospasm following SAH. Thus, our previous studies strongly suggest that post-SAH hyperglycemia is not only a response to primary insult, but also an aggravating factor for brain injuries. In addition, mitochondrial fusion and fission are vital to maintaining cellular functions. Current evidence also shows that the suppression of mitochondrial fission alleviates brain injuries after experimental SAH. Hence, this study aimed to determine the effects of mitochondrial dynamic modulation in hyperglycemia-related worse SAH neurological prognosis. Materials and methods: In vitro, we employed an enzyme-linked immunosorbent assay (ELISA) to detect the effect of mitochondrial division inhibitor-1 (Mdivi-1) on lipopolysaccharide (LPS)-induced BV-2 cells releasing inflammatory factors. In vivo, we produced hyperglycemic rats via intraperitoneal streptozotocin (STZ) injections. Hyperglycemia was confirmed using blood-glucose measurements (>300 mg/dL) 7 days after the STZ injection. The rodent model of SAH, in which fresh blood was instilled into the craniocervical junction, was used 7 days after STZ administration. We investigated the mechanism and effect of Mdivi-1, a selective inhibitor of dynamin-related protein (Drp1) to downregulate mitochondrial fission, on SAH-induced apoptosis in a hyperglycemic state, and evaluated the results in a dose–response manner. The rats were divided into the following five groups: (1) control, (2) SAH only, (3) Diabetes mellitus (DM) + SAH, (4) Mdivi-1 (0.24 mg/kg) + DM + SAH, and (5) Mdivi-1 (1.2 mg/kg) + DM + SAH. Results: In vitro, ELISA revealed that Mdivi-1 inhibited microglia from releasing inflammatory factors, such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6. In vivo, neurological outcomes in the high-dose (1.2 mg/kg) Mdivi-1 treatment group were significantly reduced compared with the SAH and DM + SAH groups. Furthermore, immunofluorescence staining and ELISA revealed that a high dose of Mdivi-1 had attenuated inflammation and neuron cell apoptosis by inhibiting Hyperglycemia-aggravated activation, as well as microglia and astrocyte proliferation, following SAH. Conclusion: Mdivi-1, a Drp-1 inhibitor, attenuates cerebral vasospasm, poor neurological outcomes, inflammation, and neuron cell apoptosis following SAH + hyperglycemia. [ABSTRACT FROM AUTHOR]

Background Mitochondrial dynamics is essential for the maintenance of healthy mitochondrial network. Emerging evidence suggests that mitochondrial dysfunction is closely linked to the pathogenesis of hepatic fibrogenesis following chronic liver injury. However, the role of dynamin-related protein 1 (Drp1)-mediated mitochondrial fission in the context of liver fibrosis remains unclear. Methods and Results In this study, C57BL/6 mice were used to establish a model of liver fibrosis via oral gavage with CCl4 treatment for 8 weeks. Furthermore, mitochondrial fission intervention experiments were achieved by the mitochondrial division inhibitor 1 (Mdivi-1). The results demonstrated that chronic CCl4 exposure resulted in severe hepatic fibrogenesis and mitochondrial damage. By contrast, pharmacological inhibition of mitochondrial division by Mdivi-1 substantially reduced the changes of mitochondrial dynamics and finally prevented the deposition of extracellular matrix proteins. Mechanistically, excessive mitochondrial fission may activate hepatic stellate cells through RIPK1-MLKL-dependent hepatocyte death, which ultimately promotes liver fibrosis. Conclusion Our study imply that inhibiting Drp1-mediated mitochondrial fission attenuates CCl4-induced liver fibrosis and may serve as a therapeutic target for retarding progression of chronic liver disease. [ABSTRACT FROM AUTHOR]

Macrophage/microglial modulation plays a critical role in the pathogenesis of multiple sclerosis (MS), which is an inflammatory disorder of the central nervous system. Dynamin-related protein 1 is a cytoplasmic molecule that regulates mitochondrial fission. It has been proven that mitochondrial fission inhibitor 1 (Mdivi-1), a small molecule inhibitor of Drp1, can relieve experimental autoimmune encephalomyelitis (EAE), a preclinical animal model of MS. Whether macrophages/microglia are involved in the pathological process of Mdivi-1-treated EAE remains to be determined. Here, we studied the anti-inflammatory effect of Mdivi-1 on mice with oligodendrocyte glycoprotein peptide35-55 (MOG35-55)–induced EAE. We found that Drp1 phosphorylation at serine 616 in macrophages/microglia was decreased with Mdivi-1 treatment, which was accompanied by decreased antigen presentation capacity of the macrophages/microglia in the EAE mouse spinal cord. The Mdivi-1 treatment caused macrophage/microglia to produce low levels of proinflammatory molecules, such as CD16/32, iNOS, and TNF-α, and high levels of anti-inflammatory molecules, such as CD206, IL-10, and Arginase-1, suggesting that Mdivi-1 promoted the macrophage/microglia shift from the inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. Moreover, Mdivi-1 was able to downregulate the expression of TRL2, TRL4, GSK-3β, and phosphorylated NF-κB-p65 and prevent NF-κB-mediated IL-1β and IL-6 production. In conclusion, these results indicate that Mdivi-1 significantly alleviates inflammation in mice with EAE by promoting M2 polarization by inhibiting TLR2/4- and GSK3β-mediated NF-κB activation. [ABSTRACT FROM AUTHOR]

This systematic review sought to determine the effects of Mitochondrial division inhibitor-1 (Mdivi-1) on neural mitochondrial dysfunction and neural mitochondria-mediated apoptosis in ischemia/reperfusion (I/R) injury after ischemic stroke. Pubmed, Web of Science, and EMBASE databases were searched through July 2021. The studies published in English language that mentioned the effects of Mdivi-1 on neural mitochondrial dysfunction and neural mitochondria-mediated apoptosis in I/R-induced brain injury were included. The CAMARADES checklist (for in vivo studies) and the TOXRTOOL checklist (for in vitro studies) were used for study quality evaluation. Twelve studies were included (median CAMARADES score = 6; TOXRTOOL scores ranging from 16 to 18). All studies investigated neural mitochondrial functions, providing that Mdivi-1 attenuated the mitochondrial membrane potential dissipation, ATP depletion, and complexes I-V abnormalities; enhanced mitochondrial biogenesis, as well as inactivated mitochondrial fission and mitophagy in I/R-induced brain injury. Ten studies analyzed neural mitochondria-mediated apoptosis, showing that Mdivi-1 decreased the levels of mitochondria-mediated proapoptotic factors (AIF, Bax, cytochrome c , caspase-9, and caspase-3) and enhanced the level of antiapoptotic factor (Bcl-2) against I/R-induced brain injury. The findings suggest that Mdivi-1 can protect neural mitochondrial functions, thereby attenuating neural mitochondria-mediated apoptosis in I/R-induced brain injury. Our review supports Mdivi-1 as a potential therapeutic compound to reduce brain damage in ischemic stroke (PROSPERO protocol registration ID: CRD42020205808). Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/], identifier [CRD42020205808]. [ABSTRACT FROM AUTHOR]

Atopic dermatitis (AD) is a chronic inflammatory cutaneous disorder with few treatment options. Dynamin‐related protein 1 (Drp1)‐dependent mitochondrial fission contributes to the activation of NLRP3 inflammasome, and inhibiting Drp1 has been become an attractive therapeutic strategy for inflammatory diseases. This study aimed to investigate the effects of Drp1 inhibitor mdivi‐1 on experimental AD. We firstly detected the effects of mdivi‐1 on primary human keratinocytes in an inflammatory cocktail‐induced AD‐related inflammation in vitro. Results showed that mdivi‐1 inhibited NLRP3 inflammasome activation and pyroptosis which were evidenced by decreased expression of NLRP3, ASC, cleavage of caspase‐1, GSDMD‐NT, mature interleukin (IL)‐1β and IL‐18 in keratinocytes under AD‐like inflammation. Next, mouse model of AD‐like skin lesions was induced by epicutaneous application of 2,4‐dinitrochlorobenzene (DNCB) and mdivi‐1 (25 mg/kg/day, days 5–33 during construction of AD model) was intraperitoneally injected into DNCB‐induced mice. AD mice with mdivi‐1 treatment exhibited ameliorated AD symptoms, lower serum IgE level, and reduced epidermal thickening, mast cells infiltration, and production of IL‐4, IL‐5 and IL‐13 in the lesional tissues. Indeed, mdivi‐1 significantly inhibited NLRP3 inflammasome activation and pyroptotic injury occurred in DNCB‐treated skin tissues. Mechanically, mdivi‐1 regulated the expression of mitochondrial dynamic proteins and suppressed the activation of NF‐κB signal pathway which is an upstream of NLRP3 inflammasome both in vitro and in vivo. This study demonstrated that mdivi‐1 could protect against experimental AD through inhibiting the activation of NLRP3 inflammasome and subsequent inflammatory cytokine release, and mdivi‐1 might exert this function by inhibiting mitochondrial fission and subsequently blocking NF‐κB pathway. [ABSTRACT FROM AUTHOR]

This systematic review sought to determine the effects of Mitochondrial division inhibitor-1 (Mdivi-1) on neural mitochondrial dysfunction and neural mitochondria-mediated apoptosis in ischemia/reperfusion (I/R) injury after ischemic stroke. Pubmed, Web of Science, and EMBASE databases were searched through July 2021. The studies published in English language that mentioned the effects of Mdivi-1 on neural mitochondrial dysfunction and neural mitochondria-mediated apoptosis in I/R-induced brain injury were included. The CAMARADES checklist (for in vivo studies) and the TOXRTOOL checklist (for in vitro studies) were used for study quality evaluation. Twelve studies were included (median CAMARADES score = 6; TOXRTOOL scores ranging from 16 to 18). All studies investigated neural mitochondrial functions, providing that Mdivi-1 attenuated the mitochondrial membrane potential dissipation, ATP depletion, and complexes I-V abnormalities; enhanced mitochondrial biogenesis, as well as inactivated mitochondrial fission and mitophagy in I/R-induced brain injury. Ten studies analyzed neural mitochondria-mediated apoptosis, showing that Mdivi-1 decreased the levels of mitochondria-mediated proapoptotic factors (AIF, Bax, cytochrome c, caspase-9, and caspase-3) and enhanced the level of antiapoptotic factor (Bcl-2) against I/R-induced brain injury. The findings suggest that Mdivi-1 can protect neural mitochondrial functions, thereby attenuating neural mitochondria-mediated apoptosis in I/R-induced brain injury. Our review supports Mdivi-1 as a potential therapeutic compound to reduce brain damage in ischemic stroke (PROSPERO protocol registration ID: CRD42020205808).Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/], identifier [CRD42020205808].

Sepsis-associated organ dysfunction plays a critical role in its high mortality, mainly in connection with mitochondrial dysfunction. Whether the inhibition of mitochondrial fission is beneficial to sepsis-related organ dysfunction and underlying mechanisms are unknown. Cecal ligation and puncture induced sepsis in rats and dynamic related protein 1 knockout mice, lipopolysaccharide-treated vascular smooth muscle cells and cardiomyocytes, were used to explore the effects of inhibition of mitochondrial fission and specific mechanisms. Our study showed that mitochondrial fission inhibitor Mdivi-1 could antagonize sepsis-induced organ dysfunction including heart, vascular smooth muscle, liver, kidney, and intestinal functions, and prolonged animal survival. The further study showed that mitochondrial functions such as mitochondrial membrane potential, adenosine-triphosphate contents, reactive oxygen species, superoxide dismutase and malonaldehyde were recovered after Mdivi-1 administration via improving mitochondrial morphology. And sepsis-induced inflammation and apoptosis in heart and vascular smooth muscle were alleviated through inhibition of mitochondrial fission and mitochondrial function improvement. The parameter trends in lipopolysaccharide-stimulated cardiomyocytes and vascular smooth muscle cells were similar in vivo. Dynamic related protein 1 knockout preserved sepsis-induced organ dysfunction, and the animal survival was prolonged. Taken together, this finding provides a novel effective candidate therapy for severe sepsis/septic shock and other critical clinical diseases.

Sepsis-associated organ dysfunction plays a critical role in its high mortality, mainly in connection with mitochondrial dysfunction. Whether the inhibition of mitochondrial fission is beneficial to sepsis-related organ dysfunction and underlying mechanisms are unknown. Cecal ligation and puncture induced sepsis in rats and dynamic related protein 1 knockout mice, lipopolysaccharide-treated vascular smooth muscle cells and cardiomyocytes, were used to explore the effects of inhibition of mitochondrial fission and specific mechanisms. Our study showed that mitochondrial fission inhibitor Mdivi-1 could antagonize sepsis-induced organ dysfunction including heart, vascular smooth muscle, liver, kidney, and intestinal functions, and prolonged animal survival. The further study showed that mitochondrial functions such as mitochondrial membrane potential, adenosine-triphosphate contents, reactive oxygen species, superoxide dismutase and malonaldehyde were recovered after Mdivi-1 administration via improving mitochondrial morphology. And sepsis-induced inflammation and apoptosis in heart and vascular smooth muscle were alleviated through inhibition of mitochondrial fission and mitochondrial function improvement. The parameter trends in lipopolysaccharide-stimulated cardiomyocytes and vascular smooth muscle cells were similar in vivo. Dynamic related protein 1 knockout preserved sepsis-induced organ dysfunction, and the animal survival was prolonged. Taken together, this finding provides a novel effective candidate therapy for severe sepsis/septic shock and other critical clinical diseases. [ABSTRACT FROM AUTHOR]

Abstract Background Unrestrained activation of Th1 and Th17 cells is associated with the pathogenesis of multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). While inactivation of dynamin-related protein 1 (Drp1), a GTPase that regulates mitochondrial fission, can reduce EAE severity by protecting myelin from demyelination, its effect on immune responses in EAE has not yet been studied. Methods We investigated the effect of Mdivi-1, a small molecule inhibitor of Drp1, on EAE. Clinical scores, inflammation, demyelination and Drp1 activation in the central nervous system (CNS), and T cell responses in both CNS and periphery were determined. Results Mdivi-1 effectively suppressed EAE severity by reducing demyelination and cellular infiltration in the CNS. Mdivi-1 treatment decreased the phosphorylation of Drp1 (ser616) on CD4+ T cells, reduced the numbers of Th1 and Th17 cells, and increased Foxp3+ regulatory T cells in the CNS. Moreover, Mdivi-1 treatment effectively inhibited IFN-γ+, IL-17+, and GM-CSF+ CD4+ T cells, while it induced CD4+ Foxp3+ regulatory T cells in splenocytes by flow cytometry. Conclusions Together, our results demonstrate that Mdivi-1 has therapeutic potential in EAE by modulating the balance between Th1/Th17 and regulatory T cells.

Mitochondrial division inhibitor 1 (Mdivi-1) reportedly provides a close connection between oocyte maturation and mitochondrial function in pigs. N-acetyl-5-methoxy-tryptamine (melatonin) is known to be a representative antioxidant with the ability to rehabilitate meiotic maturation of porcine oocytes. However, the ability of melatonin to recover Mdivi-1-mediated disruption of spindle formation during meiotic maturation of porcine oocytes during in vitro maturation (IVM) has not been studied. Here, we first investigated changes in mitochondrial length, such as fragmentation and elongation form, in mature porcine oocytes during IVM. Mature oocytes require appropriate mitochondrial fission for porcine oocyte maturation. We identified a dose-dependent reduction in meiotic maturation in porcine oocytes following Mdivi-1 treatment (50, 75, and 100 μM). We also confirmed changes in mitochondrial fission protein levels [dynamin-related protein 1 phosphorylation at serine 616 (pDRP1-Ser616) and dynamin-related protein 1 (DRP1)], mitochondrial membrane potential, and ATP production in 75 μM Mdivi-1-treated oocytes. As expected, Mdivi-1 significantly reduced mitochondrial function and DRP1 protein levels and increased spindle abnormalities in porcine oocytes. In addition, we confirmed that melatonin restores abnormal spindle assembly and reduces meiotic maturation rates by Mdivi-1 during porcine oocyte maturation. Interestingly, the expression levels of genes that reduce DNA damage and improve tubulin formation were enhanced during porcine meiotic maturation. Taken together, these results suggest that melatonin has direct beneficial effects on meiotic maturation through tubulin formation factors during porcine oocyte maturation.

As a selective inhibitor of mitochondrial fission protein dynamin-related protein-1 (Drp1), mitochondrial division inhibitor 1 (mdivi-1) can cross the blood–brain barrier (BBB) and exert neuroprotection. However, it remains unclear whether mdivi-1 can attenuate intracerebral hemorrhage (ICH)-induced secondary brain injury. This study was undertaken to characterize the roles of mdivi-1 in short-term and long-term behavioral outcomes, along with synaptic plasticity changes in mice after ICH. The results indicated mdivi-1 reversed Drp1 translocation and the morphologic changes of mitochondria, as well as ameliorated short-term neurobehavioral deficits, the BBB disruption and brain edema remarkably. In addition, mdivi-1 could rescue ICH-induced motor and memory dysfunctions. Mdivi-1 could also prevent ICH-induced reductions in synaptic proteins (synapsin I, PSD95) and phosphorylated cAMP-response element binding (p-CREB). In vitro, mdivi-1 inhibited hemin-induced hippocampal neuron death and improved neurite outgrowth. In conclusion, we found that mdivi-1 can alleviate short-term and long-term neurological deficits, synaptic dysfunction. These findings demonstrate that mdivi-1 may be beneficial in the treatment of secondary brain injury, synaptic dysfunction and neurological outcomes caused by ICH. [ABSTRACT FROM AUTHOR]

Amyotrophic lateral sclerosis (ALS) is an extremely complex neurodegenerative disease involving different cell types, but motoneuronal loss represents its main pathological feature. Moreover, compensatory plastic changes taking place in parallel to neurodegeneration are likely to affect the timing of ALS onset and progression and, interestingly, they might represent a promising target for disease-modifying treatments. Therefore, a simplified animal model mimicking motoneuronal loss without the other pathological aspects of ALS has been established by means of intramuscular injection of cholera toxin-B saporin (CTB-Sap), which is a targeted neurotoxin able to kill motoneurons by retrograde suicide transport. Previous studies employing the mouse CTB-Sap model have proven that spontaneous motor recovery is possible after a subtotal removal of a spinal motoneuronal pool. Although these kinds of plastic changes are not enough to counteract the functional effects of the progressive motoneuron degeneration, it would nevertheless represent a promising target for treatments aiming to postpone ALS onset and/or delay disease progression. Herein, the mouse CTB-Sap model has been used to test the efficacy of mitochondrial division inhibitor 1 (Mdivi-1) as a tool to counteract the CTB-Sap toxicity and/or to promote neuroplasticity. The homeostasis of mitochondrial fission/fusion dynamics is indeed important for cell integrity, and it could be affected during neurodegeneration. Lesioned mice were treated with Mdivi-1 and then examined by a series of behavioral test and histological analyses. The results have shown that the drug may be capable of reducing functional deficits after the lesion and promoting synaptic plasticity and neuroprotection, thus representing a putative translational approach for motoneuron disorders., Competing Interests: The authors declare no conflicts of interest.

Background: Bronchopulmonary dysplasia (BPD) is the most common chronic respiratory disease in premature infants. Oxygen inhalation and mechanical ventilation are common treatments, which can cause hyperoxia-induced lung injury, but the underlying mechanism is not yet understood. Mitochondrial fission is essential for mitochondrial homeostasis. The objective of this study was to determine whether mitochondrial fission (dynamin-related protein 1, Drp1) is an important mediator of hyperoxia lung injury in rats.Methods: The animal model of BPD was induced with high oxygen (80–85% O2). Pulmonary histological changes were observed by hematoxylin-eosin (HE) staining. Pulmonary microvessels were observed by immunofluorescence staining of von Willebrand Factor (vWF). Protein expression levels of Drp1 and p-Drp1 (Ser616) were observed using Western Blot. We used echocardiography to measure pulmonary artery acceleration time (PAT), pulmonary vascular resistance index (PVRi), peak flow velocity of the pulmonary artery (PFVP), pulmonary arteriovenous diameter, and pulmonary vein peak velocity. Mitochondrial division inhibitor-1 (Mdivi-1) was used as an inhibitor of Drp1, and administered through intraperitoneal injection (25 mg/kg).Results: Pulmonary artery resistance of the hyperoxide-induced neonatal rat model of BPD increased after it entered normoxic convalescence. During the critical stage of alveolar development in neonatal rats exposed to high oxygen levels for an extended period, the expression and phosphorylation of Drp1 increased in lung tissues. When Drp1 expression was inhibited, small pulmonary vessel development improved and PH was relieved.Conclusion: Our study shows that excessive mitochondrial fission is an important mediator of hyperoxia-induced pulmonary vascular injury, and inhibition of mitochondrial fission may be a useful treatment for hyperoxia-induced related pulmonary diseases.

Vascular dysfunctions such as vascular hyporeactivity following ischemic/hypoxic injury are a major cause of death in injured patients. In this study, we showed that treatment with mitochondrial division inhibitor 1 (Mdivi-1), a selective inhibitor of dynamin-related protein 1 (Drp1), significantly improved vascular reactivity in ischemic rats by attenuating oxidative stress. The antioxidative effects of Mdivi-1 were relatively Drp1-independent, and possibly due to an increase in the levels of the antioxidant enzymes, SOD1 and catalase, as well as to enhanced Nrf2 expression. In addition, we found that while Mdivi-1 had little effect on Drp1 GTPase activity in vascular smooth muscle cells, it inhibited hypoxia-induced Drp1 phosphorylation at Ser-616, reducing excessive mitochondrial fission and slightly enhancing mitochondrial fusion. These effects possibly contributed to vascular protection at an early stage of ischemic/hypoxic injury. Finally, Mdivi-1 stabilized hemodynamics, increased vital organ perfusion, and improved rat survival after ischemic/hypoxic injury, proving a promising therapeutic agent for ischemic/hypoxic injury.

Mitochondria are highly dynamic organelles that constantly undergo fission and fusion events to adapt to changes in the cellular environment. Aberrant mitochondrial fission has been associated with several types of cardiovascular dysfunction; inhibition of pathologically aberrant mitochondrial fission has been shown to be cardioprotective. Pathological fission is mediated by the excessive activation of GTPase dynamin-related protein 1 (Drp1), making it an attractive therapeutic target in numerous cardiovascular diseases. Mitochondrial division inhibitor (mdivi-1) is widely used small molecule reported to inhibit Drp1-dependent fission, elongate mitochondria, and mitigate injury. The purpose of our study was to understand the pleiotropic effects of mdivi-1 on mitochondrial dynamics, mitochondrial respiration, electron transport activities, and macro-autophagy. In this study, we found that mdivi-1 treatment decreased Drp1 expression, proteolytically cleaved L-OPA1, and altered the expression of OXPHOS complex proteins, resulting in increased superoxide production. The altered expression of OXPHOS complex proteins may be directly associated with decreased Drp1 expression, as Drp1 siRNA knockdown in cardiomyocytes showed similar effects. Results from an autophagy flux assay showed that mdivi-1 induced impaired autophagy flux that could be restored by Atg7 overexpression, suggesting that mdivi-1 mediated inhibition of macro-autophagy in cardiomyocytes. Treatment with mdivi-1 resulted in increased expression of p62, which is required for Atg7 overexpression-induced rescue of mdivi-1-mediated impaired autophagy flux. In addition, mdivi-1-dependent proteolytic processing of L-OPA1 was associated with increased mitochondrial superoxide production and altered expression of mitochondrial serine/proteases. Overall, the novel pleiotropic effect of mdivi-1 in cardiomyocytes included proteolytically cleaved L-OPA1, altered expression of OXPHOS complex proteins, and increased superoxide production, which together resulted in defects in mitochondrial respiration and inhibition of macro-autophagy.

Cervical spondylotic myelopathy (CSM) is a leading cause of spinal cord dysfunction with few treatment options. Although mitochondrial dynamics are linked to a wide range of pathological changes in neurodegenerative diseases, a connection between aberrant mitochondrial dynamics and CSM remains to be illuminated. In addition, mechanisms underlying the emerging anti-inflammatory and neuroprotective effects of echinacoside (ECH), the main active ingredient of Cistanche salsa , are poorly understood. We hypothesized that excessive mitochondrial fission plays a critical role in regulating inflammatory responses in CSM, and ECH might alleviate such responses by regulating mitochondrial dynamics. To this end, we assessed the effects of ECH and Mdivi-1, a selective inhibitor of dynamin-related protein (Drp1), in a rat model of chronic cervical cord compression and activated BV2 cells. Our results showed that rats with Mdivi-1 intervention had improved motor function compared with vehicle-treated rats. Indeed, Mdivi-1 treatment attenuated pro-inflammatory cytokine expression, as well as activation of the nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, nuclear transcription factor-κB (NF-κB), and Drp1 in lesions. Compared with vehicle-treated rats, compression sites of Mdivi-1-treated animals exhibited elongated mitochondrial morphologies and reduced reactive oxygen species (ROS). Similarly, ECH-treated rats exhibited neurological recovery and suppression of inflammatory response or related signals in the lesion area after treatment. Interestingly, ECH treatment partly reversed aberrant mitochondrial fragmentation and oxidative stress within the lesion area. In vitro data suggested that ECH suppressed activated microglia by modulating activation of the NLRP3 inflammasome and NF-κB signaling. Furthermore, we observed that ECH markedly inhibited Drp1 translocation onto mitochondria, whereby it regulated mitochondrial dynamics and ROS production, which act as regulators of NLRP3 inflammasome activation and NF-κB signaling. Thus, our findings reveal that mitochondrial dynamics modulate inflammatory responses during CSM. Moreover, ECH may attenuate neuroinflammation in rats subjected to chronic cervical cord compression by regulating Drp1-dependent mitochondrial fission and activation of downstream signaling. Image 1 • Chronic compression to cervical cord leads to the mitochondrial fission event in lesion area. • Mitochondrial dynamics modulate inflammatory responses during cervical spondylotic myelopathy. • Echinacoside attenuated inflammatory responses in a rat chronic cervical cord compression model. • Neuroprotective effects of echinacoside may be associated with its role on mitochondrial dynamics and downstream signaling. [ABSTRACT FROM AUTHOR]

Autosomal dominant polycystic kidney disease (ADPKD) is a common monogenic disorder, characterized by bilateral renal cyst formation. Multiple pathways are de‐regulated in cystic epithelia offering good opportunities for therapy. Others and we have previously reported that metabolic reprogramming, including alterations of the TCA cycle, are prominent features of ADPKD. Several lines of evidence suggest that mitochondrial impairment might be responsible for the metabolic alterations. Here, we performed morphologic and morphometric evaluation of mitochondria by TEM in an orthologous mouse model of PKD caused by mutations in the Pkd1 gene (Ksp‐Cre;Pkd1flox/−). Furthermore, we measured mitochondrial respiration by COX and SDH enzymatic activity in situ. We found several alterations including reduced mitochondrial mass, altered structure and fragmentation of the mitochondrial network in cystic epithelia of Ksp‐Cre;Pkd1flox/− mice. At the molecular level, we found reduced expression of the pro‐fusion proteins OPA1 and MFN1 and up‐regulation of the pro‐fission protein DRP1. Importantly, administration of Mdivi‐1, which interferes with DRP1 rescuing mitochondrial fragmentation, significantly reduced kidney/body weight, cyst formation, and improved renal function in Ksp‐Cre;Pkd1flox/− mice. Our data indicate that impaired mitochondrial structure and function play a role in disease progression, and that their improvement can significantly modify the course of the disease. [ABSTRACT FROM AUTHOR]

Mdivi-1, Mitochondrial DIVIsion inhibitor 1, has been widely employed in research under the assumption that it exclusively influences mitochondrial fusion, but effects other than mitochondrial dynamics have been underinvestigated. This paper provides transcriptome and DNA methylome-wide analysis for Mdivi-1 treated SH-SY5Y human neuroblastoma cells using RNA sequencing (RNA-seq) and methyl capture sequencing (MC-seq) methods. Gene ontology analysis of RNA sequences revealed that p53 transcriptional gene network and DNA replication initiation-related genes were significantly up and down-regulated, respectively, showing the correlation with the arrest cell cycle in the G1 phase. MC-seq, a powerful sequencing method for capturing DNA methylation status in CpG sites, revealed that although Mdivi-1 does not induce dramatic DNA methylation change, the subtle alterations were concentrated within the CpG island. Integrative analysis of both sequencing data disclosed that the p53 transcriptional network was activated while the Parkinson's disease pathway was halted. Next, we investigated several changes in mitochondria in response to Mdivi-1. Copy number and transcription of mitochondrial DNA were suppressed. ROS levels increased, and elevated ROS triggered mitochondrial retrograde signaling rather than inducing direct DNA damage. In this study, we could better understand the molecular network of Mdivi-1 by analyzing DNA methylation and mRNA transcription in the nucleus and further investigating various changes in mitochondria, providing inspiration for studying nuclear-mitochondrial communications. • First reported Mdivi-1-induced DNA methylome shows Mdivi-1 dwindles CGI methylation. • RNA/DNA-methyl sequencing integration unveils Mdivi-1's therapeutic mechanism. • Mdivi-1 modulates retrograde signaling by ROS. [ABSTRACT FROM AUTHOR]

New treatments are needed to prevent neointimal hyperplasia that contributes to post-angioplasty and stent restenosis in patients with coronary artery disease (CAD) and peripheral arterial disease (PAD). We investigated whether modulating mitochondrial function using mitochondrial division inhibitor-1 (Mdivi-1) could reduce post-vascular injury neointimal hyperplasia by metabolic reprogramming of macrophages from a pro-inflammatory to anti-inflammatory phenotype. In vivo Mdivi-1 treatment of Apoe −/− mice fed a high-fat diet and subjected to carotid-wire injury decreased neointimal hyperplasia by 68%, reduced numbers of plaque vascular smooth muscle cells and pro-inflammatory M1-like macrophages, and decreased plaque inflammation, endothelial activation, and apoptosis, when compared to control. Mdivi-1 treatment of human THP-1 macrophages shifted polarization from a pro-inflammatory M1-like to an anti-inflammatory M2-like phenotype, reduced monocyte chemotaxis and migration to CCL2 and macrophage colony stimulating factor (M-CSF) and decreased secretion of pro-inflammatory mediators. Finally, treatment of pro-inflammatory M1-type-macrophages with Mdivi-1 metabolically reprogrammed them to an anti-inflammatory M2-like phenotype by inhibiting oxidative phosphorylation and attenuating the increase in succinate levels and correcting the decreased levels of arginine and citrulline. We report that treatment with Mdivi-1 inhibits post-vascular injury neointimal hyperplasia by metabolic reprogramming macrophages towards an anti-inflammatory phenotype thereby highlighting the therapeutic potential of Mdivi-1 for preventing neointimal hyperplasia and restenosis following angioplasty and stenting in CAD and PAD patients. [Display omitted] • Mdivi-1 reduces neointimal hyperplasia post-vascular injury via immune cell metabolic reprogramming. • Mdivi-1 inhibits pro-inflammatory gene/protein expression in monocytes/macrophages, affecting polarization. • Mdivi-1 prevents monocyte migration and lowers oxidative metabolism in monocytes/macrophages. • Mitochondrial modulation in inflammatory cells offers a novel therapy for post-angioplasty restenosis in CAD/PAD. [ABSTRACT FROM AUTHOR]

Background/Aims: Endothelin-1 is implicated in the pathogenesis of hypertension, but the underlying mechanisms remained elusive. Our previous study found that inhibition of mitochondrial fission of smooth muscle cells suppressed phenylephrine- and high K+-induced artery constriction. Here, we studied the effects of mitochondrial fission inhibitors on endothelin-1-induced vasoconstriction. Methods: The tension of rat mesenteric arteries and thoracic aorta was measured by using a multi-wire myograph system. Mitochondrial morphology of aortic smooth muscle cells was observed by using transmission electron microscopy. Results: Dynamin-related protein-1 selective inhibitor mdivi-1 relaxed endothelin-1-induced constriction, and mdivi-1 pre-treatment prevented endothelin-1-induced constriction of rat mesenteric arteries with intact and denuded endothelium. Mdivi-1 had a similar inhibitory effect on rat thoracic aorta. Another mitochondrial fission inhibitor dynasore showed similar effects as mdivi-1 in rat mesenteric arteries. Mdivi-1 inhibited endothelin-1-induced increase of mitochondrial fission in smooth muscle cells of rat aorta. Rho-associated protein kinase inhibitor Y-27632 which relaxed endothelin-1-induced vasoconstriction inhibited endothelin-1-induced mitochondrial fission in smooth muscle cells of rat aorta. Conclusion: Endothelin-1 increases mitochondrial fission in vascular smooth muscle cells, and mitochondrial fission inhibitors suppress endothelin-1-induced vasoconstriction.

Metabolism describes the life-sustaining chemical reactions in organisms that provide both energy and building blocks for cellular survival and proliferation. Dysregulated metabolism leads to many life-threatening diseases including obesity, diabetes, and cancer. Mitochondria, subcellular organelles, contain the central energy-producing metabolic pathway, the tricarboxylic acid (TCA) cycle. Also, mitochondria exist in a dynamic network orchestrated by extracellular nutrient levels and intracellular energy needs. Upon stimulation, mitochondria undergo consistent interchange through fusion (small to big) and fission (big to small) processes. Mitochondrial fusion is primarily controlled by three GTPases, mitofusin 1 (Mfn1), Mfn2, and optic atrophy 1 (Opa1), while mitochondrial fission is primarily regulated by GTPase dynamin-related protein 1 (Drp1). Dysregulated activity of these GTPases results in disrupted mitochondrial dynamics and cellular metabolism. This review will update the metabolic roles of these GTPases in obesity, diabetes, and cancer.

Metabolism describes the life-sustaining chemical reactions in organisms that provide both energy and building blocks for cellular survival and proliferation. Dysregulated metabolism leads to many life-threatening diseases including obesity, diabetes, and cancer. Mitochondria, subcellular organelles, contain the central energy-producing metabolic pathway, the tricarboxylic acid (TCA) cycle. Also, mitochondria exist in a dynamic network orchestrated by extracellular nutrient levels and intracellular energy needs. Upon stimulation, mitochondria undergo consistent interchange through fusion (small to big) and fission (big to small) processes. Mitochondrial fusion is primarily controlled by three GTPases, mitofusin 1 (Mfn1), Mfn2, and optic atrophy 1 (Opa1), while mitochondrial fission is primarily regulated by GTPase dynamin-related protein 1 (Drp1). Dysregulated activity of these GTPases results in disrupted mitochondrial dynamics and cellular metabolism. This review will update the metabolic roles of these GTPases in obesity, diabetes, and cancer. [ABSTRACT FROM AUTHOR]