Regulation of mitochondrial respiration and apoptosis through cell signaling: cytochrome c oxidase and cytochrome c in ischemia/reperfusion injury and inflammation

Postnatal and juvenile fluoxetine treatment evokes sex-specific, opposing effects on mood-related behavior, gene expression, mitochondrial function, and dendritic architecture in the rat medial prefrontal cortex

BACKGROUND

Serotonin shapes emotional neurocircuit development, and serotonergic neurotransmission is implicated in both the pathophysiology and treatment of neuropsychiatric disorders. The selective serotonin reuptake inhibitor, fluoxetine (Flx) is a common first-line treatment for childhood and adolescent mood disorders given a favourable risk-benefit profile. Using a rodent model we addressed specific long-term behavioral, molecular, bioenergetic and cytoarchitectural consequences of postnatal (PNFlx) and juvenile (JFlx) fluoxetine treatment.

METHODS

Rat pups received PNFlx (postnatal day 2: P2-P21) or JFlx (P28-48) treatment with the impact on anxiety- and despair-like behavior examined in adulthood, along with assessing global gene expression, mitochondrial function, and dendritic cytoarchitecture in the medial prefrontal cortex (mPFC).

RESULTS

PNFlx and JFlx evoked long-lasting, opposing changes in anxiety- and despair-like behavior in male, but not female, rats. The PNFlx- and JFlx-evoked increase and decrease in anxiety- and despair-like behavior respectively, were accompanied by distinctive, minimally overlapping, transcriptional changes in the mPFC in adulthood. Furthermore, we noted starkly differing outcomes of PNFlx and JFlx on mitochondrial function and dendritic cytoarchitecture in the mPFC. The PNFlx evoked despair-like behavior was reversed by adult-onset treatment with nicotinamide, a NAD+precursor that enhances mitochondrial bioenergetics.

CONCLUSIONS

Collectively, our findings highlight distinct developmental epochs wherein fluoxetine exposure can program long-term, sex-specific, opposing outcomes on mood-related behavior, accompanied by persistent changes in gene expression, mitochondrial function and neuronal cytoarchitecture in the mPFC in adulthood. This motivates future studies to examine a potential role for altered bioenergetics in shaping the differential impact of early fluoxetine treatment on emotionality.

Targeting enhanced mitochondrial respiration chain activity as a potential therapeutic approach for endometriosis

Endometriosis is a chronic condition defined by the presence of endometrial-like tissue outside the uterus. Since endometriotic cells share similarities with cancer cells, including uncontrolled cell growth and invasion, we investigated whether cancer cell-specific rewiring of mitochondrial signaling is also present in endometriotic cells. We utilized the endometriotic cell line 12Z and investigated its mitochondrial function in comparison with the uterine cancer cell line SK-UT-1 and the mammary epithelial cell line hTERT-HME1. We could show that the endometriotic 12Z cells share structural similarities with cancerous SK-UT-1 cells with enhanced colocalization between the endoplasmic reticulum and mitochondria and increased cristae width and density associated with facilitated mitochondrial Ca2+ uptake. However, an increase in the reduction equivalent yield and oxygen consumption rate was exclusively found in 12Z cells, whereas the reduced ΔΨm and the reverse mode of FOF1-ATP synthase were also detected in SK-UT-1 cells. These features rendered both cell types susceptible to quercetin and oligomycin A treatment. We assume that the complexes of the electron transport chain and the FOF1-ATP synthase in reverse mode have a crucial role in maintaining mitochondrial membrane potential and, thereby, mitochondrial integrity of endometriotic 12Z cells. Therefore, targeting the electron transport chain or the reverse mode of FOF1-ATP synthase may represent a promising new treatment strategy for endometriosis.

The endoplasmic reticulum-mitochondrial crosstalk involved in nanoplastics and di(2-ethylhexyl) phthalate co-exposure induced the damage to mouse mammary epithelial cells

With the extensive use of plastic products, significant amounts of microplastics, nanoplastic particles (NPs), and plasticizers such as Di(2-ethylhexyl) phthalate (DEHP) are continuously released into the environment. However, the toxic effects of NPs alone or in combination with DEHP on mammary glands remain unreported. This study investigates the impacts of NPs and DEHP on the structure and function of mouse mammary epithelial cells and elucidates the underlying molecular mechanisms. We found that co-exposure to NPs and DEHP induced severe pyroptosis, inflammation and oxidative stress in HC11 cells. Co-exposure also caused mitochondrial damage, as evidenced by changes in mitochondrial membrane potential, increase in mitochondrial ROS and inhibition of ATP production. Moreover, NPs and DEHP co-exposure increased the transcriptional levels of endoplasmic reticulum (ER) stress-related genes, activated the inflammation-related NLRP3 signaling pathway, and damaged the cell membrane integrity. Notably, Co-exposure enhanced the ER-mitochondria crosstalk in HC11 cells, as evidenced by the upregulated transcriptional levels of ER Ca2+ channel proteins (Ip3r1, Grp75 and Vdac1), increased mitochondrial Ca2+ levels, and expanded mitochondrial-ER contact areas. In summary, this study revealed that NPs and DEHP co-exposure had the potential to induce pyroptosis and inflammation by enhancing the ER-mitochondria crosstalk, ultimately resulting in injury to mammary glands. These findings would provide some new insights into the molecular mechanisms underlying the toxic effects of NPs and DEHP to mammary glands.

The mitochondrial LONP1 protease: molecular targets and role in pathophysiology

Lon peptidase 1 (LONP1), a member of the AAA + family, is essential for maintaining mitochondrial function. Recent studies have revealed that LONP1 serves as a multifunctional enzyme, acting not only as a protease but also as a molecular chaperone, interacting with mitochondrial DNA (mtDNA), and playing roles in mitochondrial dynamics, oxidative stress, cellular respiration, and energy metabolism. LONP1 is evolutionarily highly conserved, and mutations or dysfunctions in LONP1 can lead to diseases. There is growing evidence linking LONP1 to various human diseases, such as tumors, neurodegenerative diseases, and heart diseases. This review discusses the discovery, molecular structure, subcellular localization, tissue distribution, and mitochondrial function of LONP1. Furthermore, it summarizes the associations between LONP1 and tumors, neurodegenerative diseases, and heart diseases, exploring its role in different diseases and potential molecular mechanisms. It also analyzes the regulatory effects of related inhibitors and agonists on LONP1. Considering the pleiotropic effects of LONP1, the study of LONP1 is crucial to understanding the relevant pathophysiological processes and developing strategies to modulate and control these related diseases.

Effects of in vitro cytochalasin D and hypoxia on mitochondrial energetics and biogenesis, cell signal status and actin/tubulin/Hsp/MMP entity in air-breathing fish heart

The cardiac actin cytoskeleton has a dynamic pattern of polymerisation. It is uncertain how far actin destabilisation impacts mitochondrial energetics and biogenesis, cell signal status, and structural entities in cardiomyocytes, particularly in hypoxic conditions. We thus tested the in vitro action of cytochalasin D (Cyt D), an inhibitor of actin polymerisation, in hypoxic ventricular explants to elucidate the role of the actin in mitochondrial energetics and biogenesis, cell signals and actin/tubulin/hsps/MMPs dynamics in hypoxic air-breathing fish hearts. The COX activity increased upon Cyt D exposure, whereas hypoxia lowered COX and SDH activities but increased LDH activity. The ROS increased, and NO decreased by Cyt D. COX and LDH activities, and NO content reversed after Cyt D exposure in hypoxic hearts. Cyt D exposure upregulated actin isoform expression (Actc1 and Actb1) but downregulated tubulin isoform (Tedc1). Hypoxia upregulated actin (Acta1a, Actb1, Actb2, Actc1a) tubulin (Tuba, Tubb5, Tedc1, Tubd1) and hsp (Hspa5, Hspa9, Hspa12a, Hspa14, Hspd1, Hsp90) isoform transcript expression and Cyt D in hypoxic hearts reversed these isoform's expression. Hypoxia upregulated Mmp2 and 9 transcript expressions but downregulated Mfn1, Fis1, Nfkb1, Prkacaa, and Aktip expressions, and Cyt D exposure reversed almost all these markers in hypoxic hearts. The data provide novel evidence for the mechanistic role of actin in integrating mitochondrial energetics and biogenesis, cell signal status and actin/tubulin/Hsp/MMP entity, indicating its critical cardioprotective role in defending against hypoxia. Besides proposing an air-breathing fish heart as a model, the study further brings the therapeutic potential of Cyt D towards hypoxia intervention.

Mitochondrial dynamics and quality control regulate proteostasis in neuronal ischemia-reperfusion

Mitochondrial damage and dysfunction are hallmarks of neuronal injury during cerebral ischemia-reperfusion (I/R). Critical mitochondrial functions including energy production and cell signaling are perturbed during I/R, often exacerbating damage and contributing to secondary injury. The integrity of the mitochondrial proteome is essential for efficient function. Mitochondrial proteostasis is mediated by the cooperative forces of mitophagy and intramitochondrial proteolysis. The aim of this study was to elucidate the patterns of mitochondrial protein dynamics and their key regulators during an in vitro model of neuronal I/R injury. Utilizing the MitoTimer reporter, we quantified mitochondrial protein oxidation and turnover during I/R injury, highlighting a key point at 2 h reoxygenation for aged/oxidized protein turnover. This turnover was found to be mediated by both LONP1-dependent proteolysis and PRKN/parkin-dependent mitophagy. Additionally, the proteostatic response of neuronal mitochondria is influenced by both mitochondrial fusion and fission machinery. Our findings highlight the involvement of both mitophagy and intramitochondrial proteolysis in the response to I/R injury.Abbreviations: cKO: conditional knockout; CLPP: caseinolytic mitochondrial matrix peptidase proteolytic subunit; DIV: days in vitro; DNM1L/DRP1: dynamin 1 like; ETC: electron transport chain; hR: hours after reoxygenation; I/R: ischemia-reperfusion; LONP1: lon peptidase 1, mitochondrial; mtUPR: mitochondrial unfolded protein response; OGD: oxygen glucose deprivation; OGD/R: oxygen glucose deprivation and reoxygenation; OPA1: OPA1 mitochondrial dynamin like GTPase; PINK1: PTEN induced kinase 1; PRKN: parkin RBR E3 ubiquitin protein ligase; ROI: region of interest; WT: wild-type.

Cardiac Tyrosine 97 Phosphorylation of Cytochrome c Regulates Respiration and Apoptosis

It was previously reported that tyrosine 97 (Y97) of cytochrome c is phosphorylated in cow heart tissue under physiological conditions. Y97 phosphorylation was shown to partially inhibit respiration in vitro in the reaction with purified cytochrome c oxidase. Here, we use phosphomimetic Y97E Cytc to further characterize the functional effects of this modification both in vitro and in cell culture models. In vitro, phosphomimetic Y97E Cytc showed lower activity in the reaction with purified cow heart cytochrome c oxidase (COX), decreased caspase-3 activity, and reduced rate of reduction. Additionally, the phosphomimetic Y97E Cytc tended to be resistant to heme degradation and showed an increased rate of oxidation. Intact mouse Cytc double knockout fibroblasts were transfected with plasmids coding for phosphomimetic Y97E Cytc and other variants. Compared to cells expressing wild-type Cytc, the cells expressing phosphomimetic Y97E Cytc showed reduced respiration, mitochondrial membrane potential, and reactive oxygen species production, and protection from apoptosis. In an oxygen-glucose deprivation/reoxygenation cell culture model of ischemia/reperfusion injury, mitochondrial membrane potential and reactive oxygen species production were decreased. These data show that Cytc phosphorylation controls the overall flux through the electron transport chain by maintaining optimal intermediate ΔΨm potentials for efficient ATP production while minimizing reactive oxygen species production, thus protecting the cell from apoptosis.

Terrestrial Adaptation in Chelonoidis vicina as Revealed Based on Analysis of the Complete Mitochondrial Genome

BACKGROUND/OBJECTIVES

Mitochondrial genomes are widely used in phylogenetics and evolutionary and ecological research.

METHODS

In this study, the newest mitochondrial genome of Chelonoidis vicina was assembled and annotated. The comparative mitochondrial genome and selection pressure analyses were used to examine the terrestrial adaptive evolution characteristics of C. vicina and other terrestrial reptiles.

RESULTS

The results reveal that the mitochondrial genome of the tortoise C. vicina is consistent with that of other tortoise species, comprising 13 protein-coding genes (PCGs), 2 rRNAs, 22 tRNAs, and 1 noncoding control region (CR). The analysis of selection pressure reveals the presence of positive selection sites in the COX2, COX3, Cytb, ND3, ND4, ND4L, ND5, and ND6 genes of terrestrial reptiles. Of these, the COX2 and ND3 genes exhibited faster evolutionary rates. The mitochondrial genome structure of C. vicina is consistent with that of different terrestrial reptiles. The positive selection sites of COX2 and ND3 in terrestrial reptiles are closely related to a change in mitochondrial energy metabolism, which is possibly related to terrestrial adaptability.

CONCLUSIONS

The results of this study provide new insights into the adaptive evolution of C. vicina to terrestrial niches from a mitogenomic perspective, as well as genetic resources for the protection of C. vicina.

Protective effects of phosphocreatine against Doxorubicin-Induced cardiotoxicity through mitochondrial function enhancement and apoptosis suppression via AMPK/PGC-1α signaling pathway

Doxorubicin (DOX), a potent chemotherapy drug, is limited by its cardiotoxic effects, which can lead to heart damage. This study explores the cardioprotective potential of Phosphocreatine (PCr) in vitro and in vivo models, focusing on its impact on the AMPK and PGC-1α pathways, apoptosis reduction, and mitochondrial function preservation. Advanced methodologies, including high-resolution respirometry (HRR), were employed to assess mitochondrial bioenergetics, AMPK activity, and apoptotic rates in cardiomyocytes. Electrocardiography (ECG) and echocardiography (echo) were used to monitor cardiac function in vivo. Results showed that PCr significantly activated the AMPK and PGC-1α pathways, reduced apoptosis, and stabilized mitochondrial function in cardiomyocytes exposed to DOX. There was an upregulation of AMPK and PGC-1α target genes, stabilization of mitochondrial membranes, and improvements in cellular energy production and antioxidant defenses. PCr also markedly reduced apoptotic markers, enhancing cardiomyocyte viability. ECG and echocardiography revealed that PCr preserved cardiac function, indicated by improved heart rate variability, reduced QT interval prolongation, and enhanced ejection fraction. These findings highlight PCr's potential in mitigating DOX-induced cardiotoxicity by enhancing mitochondrial function and reducing apoptosis. The study underscores the promise of PCr as an agent to reduce chemotherapy-related cardiac injuries, paving the way for further research to improve patient outcomes in cancer treatment.

Stimulation of cytochrome c oxidase activity by detergents

Cytochrome c oxidase (CytcO) is an integral membrane protein, which catalyzes four-electron reduction of oxygen linked to proton uptake and pumping. Amphipathic molecules bind in sites near the so-called K proton pathway of CytcO to reversibly modulate its activity. However, purification of CytcO for mechanistic studies typically involves the use of detergents, which may interfere with binding of these regulatory molecules. Here, we investigated the CytcO enzymatic activity as well as intramolecular electron transfer linked to proton transfer upon addition of different detergents to bovine heart mitoplasts. The CytcO activity increased upon addition of alkyl glucosides (DDM and DM) and the steroid analog GDN. The maximum stimulating effect was observed for DDM and DM, and the half-stimulating effect correlated with their CMC values. With GDN the stimulation effect was smaller and occurred at a concentration higher than CMC. A kinetic analysis suggests that the stimulation of activity is due to removal of a ligand bound near the K proton pathway, which indicates that in the native membrane this site is occupied to yield a lower than maximal possible CytcO activity. Possible functional consequences are discussed.

Regulation of mitochondrial oxidative phosphorylation through tight control of cytochrome c oxidase in health and disease - Implications for ischemia/reperfusion injury, inflammatory diseases, diabetes, and cancer

Mitochondria are essential to cellular function as they generate the majority of cellular ATP, mediated through oxidative phosphorylation, which couples proton pumping of the electron transport chain (ETC) to ATP production. The ETC generates an electrochemical gradient, known as the proton motive force, consisting of the mitochondrial membrane potential (ΔΨm, the major component in mammals) and ΔpH across the inner mitochondrial membrane. Both ATP production and reactive oxygen species (ROS) are linked to ΔΨm, and it has been shown that an imbalance in ΔΨm beyond the physiological optimal intermediate range results in excessive ROS production. The reaction of cytochrome c oxidase (COX) of the ETC with its small electron donor cytochrome c (Cytc) is the proposed rate-limiting step in mammals under physiological conditions. The rate at which this redox reaction occurs controls ΔΨm and thus ATP and ROS production. Multiple mechanisms are in place that regulate this reaction to meet the cell's energy demand and respond to acute stress. COX and Cytc have been shown to be regulated by all three main mechanisms, which we discuss in detail: allosteric regulation, tissue-specific isoforms, and post-translational modifications for which we provide a comprehensive catalog and discussion of their functional role with 55 and 50 identified phosphorylation and acetylation sites on COX, respectively. Disruption of these regulatory mechanisms has been found in several common human diseases, including stroke and myocardial infarction, inflammation including sepsis, and diabetes, where changes in COX or Cytc phosphorylation lead to mitochondrial dysfunction contributing to disease pathophysiology. Identification and subsequent targeting of the underlying signaling pathways holds clear promise for future interventions to improve human health. An example intervention is the recently discovered noninvasive COX-inhibitory infrared light therapy that holds promise to transform the current standard of clinical care in disease conditions where COX regulation has gone awry.

Ginsenoside Rg1: A Neuroprotective Natural Dammarane-Type Triterpenoid Saponin With Anti-Depressive Properties

BACKGROUND

Depression, a widespread mental disorder, presents significant risks to both physical and mental health due to its high rates of recurrence and suicide. Currently, single-target antidepressants typically alleviate depressive symptoms or delay the progression of depression rather than cure it. Ginsenoside Rg1 is one of the main ginsenosides found in Panax ginseng roots. It improves depressive symptoms through various mechanisms, suggesting its potential as a treatment for depression.

MATERIALS AND METHODS

We evaluated preclinical studies to comprehensively discuss the antidepressant mechanism of ginsenoside Rg1 and review its toxicity and medicinal value. Additionally, pharmacological network and molecular docking analyses were performed to further validate the antidepressant effects of ginsenoside Rg1.

RESULTS

The antidepressant mechanism of ginsenoside Rg1 may involve various pharmacological mechanisms and pathways, such as inhibiting neuroinflammation and over-activation of microglia, preserving nerve synapse structure, promoting neurogenesis, regulating monoamine neurotransmitter levels, inhibiting hyperfunction of the hypothalamic-pituitary-adrenal axis, and combatting antioxidative stress. Moreover, ginsenoside Rg1 preserves astrocyte gap junction function by regulating connexin43 protein biosynthesis and degradation, contributing to its antidepressant effect. Pharmacological network and molecular docking studies identified five targets (AKT1, STAT3, EGFR, PPARG, and HSP90AA1) as potential molecular regulatory sites of ginsenoside Rg1.

CONCLUSIONS

Ginsenoside Rg1 may exert its antidepressant effects via various pharmacological mechanisms. In addition, multicenter clinical case-control and molecular targeted studies are required to confirm both the clinical efficacy of ginsenoside Rg1 and its potential direct targets.

Acetyl-l-carnitine alleviates valproate-induced autism-like behaviors through attenuation of hippocampal mitochondrial dysregulation

This study aimed to evaluate the potential benefits of acetyl-L-carnitine (ALCAR) in the context of valproate-induced autism. After prenatal exposure to valproate (VPA; 600 mg/kg, i.p.) on embryonic day 12.5, followed by ALCAR treatment (300 mg/kg on postnatal days 21-49, p.o.), assessment of oxidative stress, mitochondrial membrane potential (MMP), mitochondrial biogenesis, parvalbumin interneurons, and hippocampal volume was conducted. These assessments were carried out subsequent to the evaluation of autism-like behaviors. Hippocampal analysis of oxidative factors (reactive oxygen species and malondialdehyde) and antioxidants (superoxide dismutase, catalase, and glutathione) revealed a burden of oxidative stress in VPA rats. Additionally, mitochondrial biogenesis and MMP were elevated, while the number of parvalbumin interneurons decreased. These changes were accompanied by autism-like behaviors observed in the three-chamber maze, marble burring test, and Y-maze, as well as a learning deficit in the Barnes maze. In contrast, administrating ALCAR attenuated behavioral deficits, reduced oxidative stress, improved parvalbumin-positive neuronal population, and properly modified MMP and mitochondrial biogenesis. Collectively, our results indicate that oral administration of ALCAR ameliorates autism-like behaviors, partly through its targeting oxidative stress and mitochondrial biogenesis. This suggests that ALCAR may have potential benefits ASD managing.

Enhanced neuroprotective effect of verapamil-loaded hyaluronic acid modified carbon quantum dots in an in-vitro model of amyloid-induced Alzheimer's disease

This study aims to investigate the molecular mechanisms and the neuroprotective effect of hyaluronic acid modified verapamil-loaded carbon quantum dots (VRH-loaded HA-CQDs) against an in-vitro Alzheimer's disease model induced by amyloid beta (Aβ) in SH-SY5Y and Neuro 2a neuroblastoma cells. Briefly, different HA-CQDs were prepared using hydrothermal method and optimized by Box-Behnken design to maximize quantum yield and minimize particle size. Serum stable negatively charged VRH-loaded HA-CQDs was successfully prepared by admixing the optimized HA-CQDs and VRH with association efficiency and loading capacity of 81.25 ± 3.65 % and 5.11 ± 0.81 %, respectively. Cells were pretreated with VRH solution or loaded-HA-CQDs followed by exposure to Aβ. Compared to the control group, amyloidosis led to reduction in cellular proliferation, mitochondrial membrane potential, expression of cytochrome P450, cytochrome c oxidase, CREB-regulated transcriptional coactivator 3, and mitotic index, along with marked increase in reactive oxygen species (ROS) and inflammatory cytokines. Pretreatment with VRH, either free or loaded HA-CQDs, enhanced cell survival, mitochondrial membrane potential, mitotic index, and gene expression. It also reduced inflammation and ROS. However, VRH-loaded HA-CQDs exhibited superior effectiveness in the measured parameters. These findings suggest that VRH-loaded HA-CQDs have enhanced therapeutic potential compared to free VRH in mitigating amyloidosis negative features.

A mandibular advancement device attenuates the abnormal morphology and function of mitochondria from the genioglossus in obstructive sleep apnea-hypopnea syndrome rabbits

BACKGROUND

Obstructive sleep apnea hypopnea syndrome (OSAHS) is a serious and potentially life-threatening disease. Mandibular advancement device (MAD) has the characteristics of non-invasive, comfortable, portable and low-cost, making it the preferred treatment for mild-to-moderate OSAHS. Our previous studies found that abnormal contractility and fibre type distribution of the genioglossus could be caused by OSAHS. However, whether the mitochondria participate in these tissue changes is unclear. The effect of MAD treatment on the mitochondria of the genioglossus in OSAHS is also uncertain.

OBJECTIVE

To examine the morphology and function of mitochondria from the genioglossus in a rabbit model of obstructive sleep apnea-hypopnea syndrome (OSAHS), as well as these factors after insertion of a mandibular advancement device (MAD).

METHODS

Thirty male New Zealand white rabbits were randomised into three groups: control, OSAHS and MAD, with 10 rabbits in each group. Animals in Group OSAHS and Group MAD were induced to develop OSAHS by injection of gel into the submucosal muscular layer of the soft palate. The rabbits in Group MAD were fitted with a MAD. The animals in the control group were not treated. Further, polysomnography (PSG) and cone-beam computed tomography (CBCT) scan were used to measure MAD effectiveness. CBCT of the upper airway and PSG suggested that MAD was effective. Rabbits in the three groups were induced to sleep for 4-6 h per day for eight consecutive weeks. The genioglossus was harvested and detected by optical microscopy and transmission electron microscopy. The mitochondrial membrane potential was determined by laser confocal microscopy and flow cytometry. Mitochondrial complex I and IV activities were detected by mitochondrial complex assay kits.

RESULTS

OSAHS-like symptoms were induced successfully in Group OSAHS and rescued by MAD treatment. The relative values of the mitochondrial membrane potential, mitochondrial complex I activity and complex IV activity were significantly lower in Group OSAHS than in the control group; however, there was no significant difference between Group MAD and the control group. The OSAHS-induced injury and the dysfunctional mitochondria of the genioglossus muscle were reduced by MAD treatment.

CONCLUSION

Damaged mitochondrial structure and function were induced by OSAHS and could be attenuated by MAD treatment.

Role of mitochondria in neonatal hypoxic-ischemic encephalopathy

Neonatal hypoxic-ischemic encephalopathy, an important cause of death as well as long-term disability in survivors, is caused by oxygen and glucose deprivation, and limited blood flow. Following hypoxic-ischemic injury in the neonatal brain, three main biochemical damages (excitotoxicity, oxidative stress, and exacerbated inflammation) are triggered. Mitochondria are involved in all three cascades. Mitochondria are the nexus of metabolic pathways to offer most of the energy that our body needs. Hypoxic-ischemic injury affects the characteristics of mitochondria, including dynamics, permeability, and ATP production, which also feed back into the process of neonatal hypoxic-ischemic encephalopathy. Mitochondria can be a cellular hub in inflammation, which is another main response of the injured neonatal brain. Some treatments for neonatal hypoxic-ischemic encephalopathy affect the function of mitochondria or target mitochondria, including therapeutic hypothermia and erythropoietin. This review presents the main roles of mitochondria in neonatal hypoxic-ischemic encephalopathy and discusses some potential treatments directed at mitochondria, which may foster the development of new therapeutic strategies for this encephalopathy.

Mechanism and treatment of intracerebral hemorrhage focus on mitochondrial permeability transition pore

Intracerebral hemorrhage (ICH) is the second most common subtype of stroke, characterized by high mortality and a poor prognosis. Despite various treatment methods, there has been limited improvement in the prognosis of ICH over the past decades. Therefore, it is imperative to identify a feasible treatment strategy for ICH. Mitochondria are organelles present in most eukaryotic cells and serve as the primary sites for aerobic respiration and energy production. Under unfavorable cellular conditions, mitochondria can induce changes in permeability through the opening of the mitochondrial permeability transition pore (mPTP), ultimately leading to mitochondrial dysfunction and contributing to various diseases. Recent studies have demonstrated that mPTP plays a role in the pathological processes associated with several neurodegenerative diseases including Parkinson's disease, Alzheimer's disease, Huntington's disease, ischemic stroke and ischemia-reperfusion injury, among others. However, there is limited research on mPTP involvement specifically in ICH. Therefore, this study comprehensively examines the pathological processes associated with mPTP in terms of oxidative stress, apoptosis, necrosis, autophagy, ferroptosis, and other related mechanisms to elucidate the potential mechanism underlying mPTP involvement in ICH. This research aims to provide novel insights for the treatment of secondary injury after ICH.

The ratio of cytochrome c oxidase subunit 4 isoform 4I1 and 4I2 mRNA is changed in permanent atrial fibrillation

AIMS

The conditions of hypoxia are suggested to induce permanent atrial fibrillation (AF). The regulation of COX4I2 and COX4I1 depends on oxygen availability in tissues. A role of COX4I2 in the myocardium of AF patients is supposed for pathogenesis of AF and subsequent alterations in the electron transfer chain (ETC) under hypoxia.

METHODS AND RESULTS

In vitro, influence of hypoxia on HeLa 53 cells was studied and elevated parts of COX 4I2 were confirmed. Myocardial biopsies were taken ex vivo from the patients' Right Atria with SR (n = 31) and AF (n = 11), respectively. RT- PCR for mRNA expresson, mitochondrial respiration by polarography and the protein content of cytochrome c oxidase (CytOx) subunit 4I1 and CytOx subunit 4I2 by ELISA were studied. Clinical data were correlated to the findings of gene expressions in parallel. Patients with permanent AF had a change in isoform 4I2/4I1 expression along with a decrease of isoform COX 4I1 expression. The 4I2/4I1 ratio of mRNA expression was increased from 0.630 to 1.058 in comparison. However, the protein content of CytOx subunit 4 was much lower in the AF group, whereas the respiration/units enzyme activity in both groups remained the same.

CONCLUSIONS

This study describes a possible molecular correlate for the development of AF. Due to the known functional significance of COX 4I2, mitochondrial dysfunction can be assumed as a part of the pathogenesis of AF.

Meptyldinocap induces implantation failure by forcing cell cycle arrest, mitochondrial dysfunction, and endoplasmic reticulum stress in porcine trophectoderm and endometrial luminal epithelial cells

Meptyldinocap is a dinitrophenol fungicide used to control powdery mildew. Although other dinitrophenol pesticides have been found to exhibit reproductive toxicity, studies of meptyldinocaps are scarce. This study investigated the adverse effects of meptyldinocap on porcine trophectoderm (pTr) and porcine endometrial luminal epithelial (pLE) cells, which play crucial roles in implantation. We confirmed that meptyldinocap decreased cell viability, induced apoptosis, and inhibited proliferation by decreasing proliferation-related gene expression and inducing changes in the cell cycle. Furthermore, meptyldinocap treatment caused mitochondrial dysfunction, endoplasmic reticulum stress, and disruption of calcium homeostasis. Moreover, it induces alterations in mitogen-activated protein kinase signaling cascades and reduces the migration ability, leading to implantation failure. Our findings suggest that meptyldinocap reduces the cellular functions of pTr and pLE cells, which are important for the implantation process, and interferes with interactions between the two cell lines, potentially leading to implantation failure. We also propose a mechanism by which the understudied fungicide meptyldinocap exerts its cytotoxicity.

Cardioprotective effect of antioxidant combination therapy: A highlight on MitoQ plus alpha-lipoic acid beneficial impact on myocardial ischemia-reperfusion injury in aged rats

Objective

(s): Considering the poor prognosis of ischemic heart disease and the diminished effectiveness of cardioprotective interventions in the elderly, it becomes necessary to investigate the interaction of aging with protection during myocardial ischemia/reperfusion injury (IRI). This study was conducted to assess the impact of mitoquinone (MitoQ) and alpha-lipoic acid (ALA) preconditioning on cardioprotection following IRI in aged rats.

Methods

Fifty aged male Wistar rats (22-24 months old) were divided into five groups including Sham, IR, and treatment groups receiving ALA and/or MitoQ. Treatment groups were received 100 mg/kg/day ALA by oral gavage and/or 10 mg/kg/day MitoQ by intraperitoneal injection for 14 consecutive days. An in vivo model of myocardial IRI was established through ligation of coronary artery for 30 min and it's reopening for 24 h. The left ventricles were removed at the end of reperfusion to assess oxidative stress indicators, mitochondrial function, and expression of mitochondrial dynamic genes. Myocardial infarct size (IS), hemodynamic parameters, and serum lactate dehydrogenase (LDH) level were also measured.

Results

Combination of MitoQ and ALA reduced oxidative stress, LDH level, and IS in aged hearts subjected to IRI. It also enhanced mitochondrial function and upregulated Mfn1, Mfn2, and Foxo1 and downregulated Drp1 and Fis1 gene expression. Co-administration of MitoQ and ALA partially restored IRI-induced hemodynamic changes to normal state. In all measured parameters, the effect of combined treatment was greater than monotherapies.

Conclusion

The combination therapy of MitoQ and ALA demonstrated considerable therapeutic potential in protecting the aging heart against IRI by improving oxidative stress, mitochondrial function, and dynamics in aged rats.

Long-Term Region-Specific Mitochondrial Functionality Changes in Both Cerebral Hemispheres after fMCAo Model of Ischemic Stroke

Cerebral ischemia/reperfusion (I/R) refers to a secondary brain injury that results in mitochondrial dysfunction of variable extent, leading to neuronal cell damage. The impact of this process has mainly been studied in the short term, from the early hours up to one week after blood flow reperfusion, and in the ischemic hemisphere only. The focus of this study was to assess the long-term impacts of I/R on mitochondrial functionality using high-resolution fluorespirometry to evaluate state-dependent activities in both ischemic (ipsilateral) and non-ischemic (contralateral) hemispheres of male mice 60, 90, 120, and 180 days after I/R caused by 60-min-long filament-induced middle cerebral artery occlusion (fMCAo). Our results indicate that in cortical tissues, succinate-supported oxygen flux (Complex I&II OXPHOS state) and H2O2 production (Complex II LEAK state) were significantly decreased in the fMCAo (stroke) group ipsilateral hemisphere compared to measurements in the contralateral hemisphere 60 and 90 days after stroke. In hippocampal tissues, during the Complex I&II ET state, mitochondrial respiration was generally lower in the ipsilateral compared to the contralateral hemisphere 90 days following stroke. An aging-dependent impact on mitochondria oxygen consumption following I/R injury was observed 180 days after surgery, wherein Complex I&II activities were lowest in both hemispheres. The obtained results highlight the importance of long-term studies in the field of ischemic stroke, particularly when evaluating mitochondrial bioenergetics in specific brain regions within and between separately affected cerebral hemispheres.

Erlotinib combination with a mitochondria-targeted ubiquinone effectively suppresses pancreatic cancer cell survival

BACKGROUND

Pancreatic cancer is a leading cause of cancer-related deaths. Increased activity of the epidermal growth factor receptor (EGFR) is often observed in pancreatic cancer, and the small molecule EGFR inhibitor erlotinib has been approved for pancreatic cancer therapy by the food and drug administration. Nevertheless, erlotinib alone is ineffective and should be combined with other drugs to improve therapeutic outcomes. We previously showed that certain receptor tyrosine kinase inhibitors can increase mitochondrial membrane potential (Δψm), facilitate tumor cell uptake of Δψm-sensitive agents, disrupt mitochondrial homeostasis, and subsequently trigger tumor cell death. Erlotinib has not been tested for this effect.

AIM

To determine whether erlotinib can elevate Δψm and increase tumor cell uptake of Δψm-sensitive agents, subsequently triggering tumor cell death.

METHODS

Δψm-sensitive fluorescent dye was used to determine how erlotinib affects Δψm in pancreatic adenocarcinoma (PDAC) cell lines. The viability of conventional and patient-derived primary PDAC cell lines in 2D- and 3D cultures was measured after treating cells sequentially with erlotinib and mitochondria-targeted ubiquinone (MitoQ), a Δψm-sensitive MitoQ. The synergy between erlotinib and MitoQ was then analyzed using SynergyFinder 2.0. The preclinical efficacy of the two-drug combination was determined using immune-compromised nude mice bearing PDAC cell line xenografts.

RESULTS

Erlotinib elevated Δψm in PDAC cells, facilitating tumor cell uptake and mitochondrial enrichment of Δψm-sensitive agents. MitoQ triggered caspase-dependent apoptosis in PDAC cells in culture if used at high doses, while erlotinib pretreatment potentiated low doses of MitoQ. SynergyFinder suggested that these drugs synergistically induced tumor cell lethality. Consistent with in vitro data, erlotinib and MitoQ combination suppressed human PDAC cell line xenografts in mice more effectively than single treatments of each agent.

CONCLUSION

Our findings suggest that a combination of erlotinib and MitoQ has the potential to suppress pancreatic tumor cell viability effectively.

In Situ Raman Spectroscopy Reveals Cytochrome c Redox-Controlled Modulation of Mitochondrial Membrane Permeabilization That Triggers Apoptosis

The selective interaction of cytochrome c (Cyt c) with cardiolipin (CL) is involved in mitochondrial membrane permeabilization, an essential step for the release of apoptosis activators. The structural basis and modulatory mechanism are, however, poorly understood. Here, we report that Cyt c can induce CL peroxidation independent of reactive oxygen species, which is controlled by its redox states. The structural basis of the Cyt c-CL binding was unveiled by comprehensive spectroscopic investigation and mass spectrometry. The Cyt c-induced permeabilization and its effect on membrane collapse, pore formation, and budding are observed by confocal microscopy. Moreover, cytochrome c oxidase dysfunction is found to be associated with the initiation of Cyt c redox-controlled membrane permeabilization. These results verify the significance of a redox-dependent modulation mechanism at the early stage of apoptosis, which can be exploited for the design of cytochrome c oxidase-targeted apoptotic inducers in cancer therapy.

Astrocytes Drive Divergent Metabolic Gene Expression in Humans and Chimpanzees

The human brain utilizes ∼20% of all of the body's metabolic resources, while chimpanzee brains use <10%. Although previous work shows significant differences in metabolic gene expression between the brains of primates, we have yet to fully resolve the contribution of distinct brain cell types. To investigate cell type-specific interspecies differences in brain gene expression, we conducted RNA-seq on neural progenitor cells, neurons, and astrocytes generated from induced pluripotent stem cells from humans and chimpanzees. Interspecies differential expression analyses revealed that twice as many genes exhibit differential expression in astrocytes (12.2% of all genes expressed) than neurons (5.8%). Pathway enrichment analyses determined that astrocytes, rather than neurons, diverged in expression of glucose and lactate transmembrane transport, as well as pyruvate processing and oxidative phosphorylation. These findings suggest that astrocytes may have contributed significantly to the evolution of greater brain glucose metabolism with proximity to humans.

Therapeutic potentials of terbium hydroxide nanorods for amelioration of hypoxia-reperfusion injury in cardiomyocytes

Myocardial hypoxia reperfusion (H/R) injury is the paradoxical exacerbation of myocardial damage, caused by the sudden restoration of blood flow to hypoxia affected myocardium. It is a critical contributor of acute myocardial infarction, which can lead to cardiac failure. Despite the current pharmacological advancements, clinical translation of cardioprotective therapies have proven challenging. As a result, researchers are looking for alternative approaches to counter the disease. In this regard, nanotechnology, with its versatile applications in biology and medicine, can confer broad prospects for treatment of myocardial H/R injury. Herein, we attempted to explore whether a well-established pro-angiogenic nanoparticle, terbium hydroxide nanorods (THNR) can ameliorate myocardial H/R injury. For this study, in vitro H/R-injury model was established in rat cardiomyocytes (H9c2 cells). Our investigations demonstrated that THNR enhance cardiomyocyte survival against H/R-induced cell death. This pro-survival effect of THNR is associated with reduction of oxidative stress, lipid peroxidation, calcium overload, restoration of cytoskeletal integrity and mitochondrial membrane potential as well as augmentation of cellular anti-oxidant enzymes such as glutathione-s-transferase (GST) and superoxide dismutase (SOD) to counter H/R injury. Molecular analysis revealed that the above observations are traceable to the predominant activation of PI3K-AKT-mTOR and ERK-MEK signalling pathways by THNR. Concurrently, THNR also exhibit apoptosis inhibitory effects mainly by suppression of pro-apoptotic proteins like Cytochrome C, Caspase 3, Bax and p53 with simultaneous restoration of anti-apoptotic protein, Bcl-2 and Survivin. Thus, considering the above attributes, we firmly believe that THNR have the potential to be developed as an alternative approach for amelioration of H/R injury in cardiomyocytes.

Mitoquinone Alleviates Donation after Cardiac Death Kidney Injury during Hypothermic Machine Perfusion in Rat Model

Transplanted organs are subjected to harmful conditions through stopping blood flow, hypothermic storage of the graft, and subsequent reperfusion. In particular, kidneys donated from patients after cardiac arrest (DCD) are classified as more vulnerable to ischemia-reperfusion injury (IRI). Hypothermic machine perfusion is proposed as a solution for better kidney storage before transplantation, and it is a good platform for additional graft treatment. Antioxidants have gained interest in regenerative medicine due to their ability to scavenge reactive oxygen species (ROS), which play a key role in IRI. We evaluated the effect of Mitoquinone (MitoQ), a strong mitochondria-targeted antioxidant, administered directly to the perfusing buffer. Rat kidneys were isolated, randomly classified into one of the following groups, donation after brainstem death (DBD), DCD, and DCD with MitoQ, and perfused for 22 hours with a hypothermic machine perfusion system. Subsequently, we detected levels of kidney injury (KIM-1) and oxidative stress (ROS/RNS, cytochrome C oxidase, and mitochondrial integrity) markers. We compared the activation of the apoptosis pathway (caspase 3 and 9), the concentration of phosphorylated Akt (pAkt), and the pAkt/total Akt ratio. MitoQ reduces KIM-1 concentration, total ROS/RNS, and the level of caspases. We observed a decrease in pAkt and the pAkt/total Akt ratio after drug administration. The length of warm ischemia time negatively impacts the graft condition. However, MitoQ added to the perfusing system as an 'on pump' therapy mitigates injury to the kidney before transplantation by inhibiting apoptosis and reducing ROS/RNS levels. We propose MitoQ as a potential drug for DCD graft preconditioning.

Fermented extract of mealworm (Tenebrio molitor larvae) as a dietary protein source modulates hepatic proteomic profiles in C57BLKS/J-db/db mice

This study hypothesised that fermented mealworm extract (TMP) with higher amino acid contents than nonfermented extract can be used as a dietary protein source for type 2 diabetes mellitus, and compared its effects with casein (CA) using C57BLKS/J-db/db mice. TMP marginally lowered serum insulin and leptin levels and hepatic triglyceride, and lipid droplets compared with CA group. Proteomic analysis showed that 14 proteins (H4C1, CYB5A, ANXA5, RGN, 40S ribosomal protein, Atp2, PDI, GRP78, RDX, GCH1, LDHA, GNMT, ACAA2, and UROC1) were up-regulated and 8 proteins (UQCRC1, Txndc5, SBP2, HSPA8, PHB, TF, PC, and PK) were down-regulated in the CA group compared to the normal mice. However, TMP significantly down-regulated ANXA5, RGN, Atp2, PDI, RDX, LDHA, ACAA2, and UROC1, and up-regulated UQCRC1, PHB, TF, and PK. These proteins are related to glycolysis, lactate production, fatty acid β-oxidation, oxidative stress, and endoplasmic reticulum stress. These results suggest that TMP is a potential protein source that can replace CA in type 2 diabetes.

Mitochondria of Live Mizuhopecten yessoensis Scallops Can Sensitively Respond to Quality Changes during Dry/Reimmersed Storage as Determined by TMT-Labeled Proteomic Analysis

Dry/reimmersed storage is often used in the transportation of live scallops. In this study, tandem mass tag (TMT)-labeled protein omics were used to quantitatively analyze the protein changes in scallops during dry/reimmersed stress. The results showed that during dry storage, scallops maintained cellular redox homeostasis through the upregulation of SCO1-like protein and thioredoxin domain-containing protein and reduced organic acids from the ATP synthetic process by the downregulation of NADH dehydrogenase, thereby reducing the damage caused during dry storage. During reimmersed storage, mitochondrial proteins underwent very sensitive changes. By upregulating aerobic respiration-related proteins (including proteins involved in glucose phosphate metabolism, glyceraldehyde 3-phosphate metabolism, etc.), the ATP synthesis ability was improved. However, the damage to the mitochondrial structure by dry storage could not be completely recovered, even by reimmersion. This included some apoptosis-related proteins that were obviously upregulated. In summary, compared with ATP-related indexes, mitochondria can respond more sensitively to dry storage stress.

Cytochrome c lysine acetylation regulates cellular respiration and cell death in ischemic skeletal muscle

Skeletal muscle is more resilient to ischemia-reperfusion injury than other organs. Tissue specific post-translational modifications of cytochrome c (Cytc) are involved in ischemia-reperfusion injury by regulating mitochondrial respiration and apoptosis. Here, we describe an acetylation site of Cytc, lysine 39 (K39), which was mapped in ischemic porcine skeletal muscle and removed by sirtuin5 in vitro. Using purified protein and cellular double knockout models, we show that K39 acetylation and acetylmimetic K39Q replacement increases cytochrome c oxidase (COX) activity and ROS scavenging while inhibiting apoptosis via decreased binding to Apaf-1, caspase cleavage and activity, and cardiolipin peroxidase activity. These results are discussed with X-ray crystallography structures of K39 acetylated (1.50 Å) and acetylmimetic K39Q Cytc (1.36 Å) and NMR dynamics. We propose that K39 acetylation is an adaptive response that controls electron transport chain flux, allowing skeletal muscle to meet heightened energy demand while simultaneously providing the tissue with robust resilience to ischemia-reperfusion injury.

Optimal treatment for post-MI heart failure in rats: dapagliflozin first, adding sacubitril-valsartan 2 weeks later

Background

Based on previous research, both dapagliflozin (DAPA) and sacubitril-valsartan (S/V) improve the prognosis of patients with heart failure (HF). Our study aims to investigate whether the early initiation of DAPA or the combination of DAPA with S/V in different orders would exert a greater protective effect on heart function than that of S/V alone in post-myocardial infarction HF (post-MI HF).

Methods

Rats were randomized into six groups: (A) Sham; (B) MI; (C) MI + S/V (1st d); (D) MI + DAPA (1st d); (E) MI + S/V (1st d) + DAPA (14th d); (F) MI + DAPA (1st d) + S/V (14th d). The MI model was established in rats via surgical ligation of the left anterior descending coronary artery. Histology, Western blotting, RNA-seq, and other approaches were used to explore the optimal treatment to preserve the heart function in post-MI HF. A daily dose of 1 mg/kg DAPA and 68 mg/kg S/V was administered.

Results

The results of our study revealed that DAPA or S/V substantially improved the cardiac structure and function. DAPA and S/V monotherapy resulted in comparable reduction in infarct size, fibrosis, myocardium hypertrophy, and apoptosis. The administration of DAPA followed by S/V results in a superior improvement in heart function in rats with post-MI HF than those in other treatment groups. The administration of DAPA following S/V did not result in any additional improvement in heart function as compared to S/V monotherapy in rats with post-MI HF. Our findings further suggest that the combination of DAPA and S/V should not be administered within 3 days after acute myocardial infarction (AMI), as it resulted in a considerable increase in mortality. Our RNA-Seq data revealed that DAPA treatment after AMI altered the expression of genes related to myocardial mitochondrial biogenesis and oxidative phosphorylation.

Conclusions

Our study revealed no notable difference in the cardioprotective effects of singular DAPA or S/V in rats with post-MI HF. Based on our preclinical investigation, the most effective treatment strategy for post-MI HF is the administration of DAPA during the 2 weeks, followed by the addition of S/V to DAPA later. Conversely, adopting a therapeutic scheme whereby S/V was administered first, followed by later addition of DAPA, failed to further improve the cardiac function compared to S/V monotherapy.

The Interplay between Dysregulated Metabolism and Epigenetics in Cancer

Cellular metabolism (or energetics) and epigenetics are tightly coupled cellular processes. It is arguable that of all the described cancer hallmarks, dysregulated cellular energetics and epigenetics are the most tightly coregulated. Cellular metabolic states regulate and drive epigenetic changes while also being capable of influencing, if not driving, epigenetic reprogramming. Conversely, epigenetic changes can drive altered and compensatory metabolic states. Cancer cells meticulously modify and control each of these two linked cellular processes in order to maintain their tumorigenic potential and capacity. This review aims to explore the interplay between these two processes and discuss how each affects the other, driving and enhancing tumorigenic states in certain contexts.

Inhibition of histone methyltransferase PRMT5 attenuates cisplatin-induced hearing loss through the PI3K/Akt-mediated mitochondrial apoptotic pathway

This study aimed to evaluate the therapeutic potential of inhibiting protein arginine methyltransferase 5 (PRMT5) in cisplatin-induced hearing loss. The effects of PRMT5 inhibition on cisplatin-induced auditory injury were determined using immunohistochemistry, apoptosis assays, and auditory brainstem response. The mechanism of PRMT5 inhibition on hair cell survival was assessed using RNA-seq and Cleavage Under Targets and Tagment-quantitative polymerase chain reaction (CUT&Tag-qPCR) analyses in the HEI-OC1 cell line. Pharmacological inhibition of PRMT5 significantly alleviated cisplatin-induced damage to hair cells and spiral ganglion neurons in the cochlea and decreased apoptosis by protecting mitochondrial function and preventing the accumulation of reactive oxygen species. CUT&Tag-qPCR analysis demonstrated that inhibition of PRMT5 in HEI-OC1 cells reduced the accumulation of H4R3me2s/H3R8me2s marks at the promoter region of the Pik3ca gene, thus activating the expression of Pik3ca. These findings suggest that PRMT5 inhibitors have strong potential as agents against cisplatin-induced ototoxicity and can lay the foundation for further research on treatment strategies of hearing loss.

In Vitro Skeletal Muscle Model of PGM1 Deficiency Reveals Altered Energy Homeostasis

Phosphoglucomutase 1 (PGM1) is a key enzyme for the regulation of energy metabolism from glycogen and glycolysis, as it catalyzes the interconversion of glucose 1-phosphate and glucose 6-phosphate. PGM1 deficiency is an autosomal recessive disorder characterized by a highly heterogenous clinical spectrum, including hypoglycemia, cleft palate, liver dysfunction, growth delay, exercise intolerance, and dilated cardiomyopathy. Abnormal protein glycosylation has been observed in this disease. Oral supplementation with D-galactose efficiently restores protein glycosylation by replenishing the lacking pool of UDP-galactose, and rescues some symptoms, such as hypoglycemia, hepatopathy, and growth delay. However, D-galactose effects on skeletal muscle and heart symptoms remain unclear. In this study, we established an in vitro muscle model for PGM1 deficiency to investigate the role of PGM1 and the effect of D-galactose on nucleotide sugars and energy metabolism. Genome-editing of C2C12 myoblasts via CRISPR/Cas9 resulted in Pgm1 (mouse homologue of human PGM1, according to updated nomenclature) knockout clones, which showed impaired maturation to myotubes. No difference was found for steady-state levels of nucleotide sugars, while dynamic flux analysis based on ¹³C6-galactose suggested a block in the use of galactose for energy production in knockout myoblasts. Subsequent analyses revealed a lower basal respiration and mitochondrial ATP production capacity in the knockout myoblasts and myotubes, which were not restored by D-galactose. In conclusion, an in vitro mouse muscle cell model has been established to study the muscle-specific metabolic mechanisms in PGM1 deficiency, which suggested that galactose was unable to restore the reduced energy production capacity.

Non-invasive treatment of ischemia/reperfusion injury: Effective transmission of therapeutic near-infrared light into the human brain through soft skin-conforming silicone waveguides

Noninvasive delivery of near-infrared light (IRL) to human tissues has been researched as a treatment for several acute and chronic disease conditions. We recently showed that use of specific IRL wavelengths, which inhibit the mitochondrial enzyme cytochrome c oxidase (COX), leads to robust neuroprotection in animal models of focal and global brain ischemia/reperfusion injury. These life-threatening conditions can be caused by an ischemic stroke or cardiac arrest, respectively, two leading causes of death. To translate IRL therapy into the clinic an effective technology must be developed that allows efficient delivery of IRL to the brain while addressing potential safety concerns. Here, we introduce IRL delivery waveguides (IDWs) which meet these demands. We employ a low-durometer silicone that comfortably conforms to the shape of the head, avoiding pressure points. Furthermore, instead of using focal IRL delivery points via fiberoptic cables, lasers, or light-emitting diodes, the distribution of the IRL across the entire area of the IDW allows uniform IRL delivery through the skin and into the brain, preventing "hot spots" and thus skin burns. The IRL delivery waveguides have unique design features, including optimized IRL extraction step numbers and angles and a protective housing. The design can be scaled to fit various treatment areas, providing a novel IRL delivery interface platform. Using fresh (unfixed) human cadavers and isolated cadaver tissues, we tested transmission of IRL via IDWs in comparison to laser beam application with fiberoptic cables. Using the same IRL output energies IDWs performed superior in comparison to the fiberoptic delivery, leading to an up to 95% and 81% increased IRL transmission for 750 and 940 nm IRL, respectively, analyzed at a depth of 4 cm into the human head. We discuss the unique safety features and potential further improvements of the IDWs for future clinical implementation.

Calcium-Signalling in Human Glaucoma Lamina Cribrosa Myofibroblasts

Glaucoma is one of the most common causes of treatable visual impairment in the developed world, affecting approximately 64 million people worldwide, some of whom will be bilaterally blind from irreversible optic nerve damage. The optic nerve head is a key site of damage in glaucoma where there is fibrosis of the connective tissue in the lamina cribrosa (LC) extracellular matrix. As a ubiquitous second messenger, calcium (Ca²⁺) can interact with various cellular proteins to regulate multiple physiological processes and contribute to a wide range of diseases, including cancer, fibrosis, and glaucoma. Our research has shown evidence of oxidative stress, mitochondrial dysfunction, an elevated expression of Ca²⁺ entry channels, Ca²⁺-dependent pumps and exchangers, and an abnormal rise in cytosolic Ca²⁺ in human glaucomatous LC fibroblast cells. We have evidence that this increase is dependent on Ca²⁺ entry channels located in the plasma membrane, and its release is from internal stores in the endoplasmic reticulum (ER), as well as from the mitochondria. Here, we summarize some of the molecular Ca²⁺-dependent mechanisms related to this abnormal Ca²⁺-signalling in human glaucoma LC cells, with a view toward identifying potential therapeutic targets for ongoing optic neuropathy.

Accelerated Evolution of Cytochrome c in Higher Primates, and Regulation of the Reaction between Cytochrome c and Cytochrome Oxidase by Phosphorylation

Cytochrome c (Cc) underwent accelerated evolution from the stem of the anthropoid primates to humans. Of the 11 amino acid changes that occurred from horse Cc to human Cc, five were at Cc residues near the binding site of the Cc:CcO complex. Single-point mutants of horse and human Cc were made at each of these positions. The Cc:CcO dissociation constant K_D of the horse mutants decreased in the order: T89E > native horse Cc > V11I Cc > Q12M > D50A > A83V > native human. The largest effect was observed for the mutants at residue 50, where the horse Cc D50A mutant decreased K_D from 28.4 to 11.8 μM, and the human Cc A50D increased K_D from 4.7 to 15.7 μM. To investigate the role of Cc phosphorylation in regulating the reaction with CcO, phosphomimetic human Cc mutants were prepared. The Cc T28E, S47E, and Y48E mutants increased the dissociation rate constant k_d, decreased the formation rate constant k_f, and increased the equilibrium dissociation constant K_D of the Cc:CcO complex. These studies indicate that phosphorylation of these residues plays an important role in regulating mitochondrial electron transport and membrane potential ΔΨ.

Lutein attenuated methylglyoxal-induced oxidative damage and apoptosis in PC12 cells via the PI3K/Akt signaling pathway

Methylglyoxal (MGO), a cytotoxic byproduct of glycolysis, causes neuro oxidative damage and apoptosis, and plays key roles in diabetic encephalopathy (DE). The goal of this research was to evaluate the roles of lutein attenuated MGO-induced damage in PC12 cells as well as the underlying mechanisms. The findings of this study showed that lutein has a significant impact on reducing the generation of reactive oxygen species (ROS) and oxidative stress in MGO-induced PC12 cells, which may be attributed to the increased antioxidant enzymes activity and the decreased MDA levels. Moreover, treatment with lutein also alleviated cell apoptosis and mitochondrial damage. Real-time PCR and western blot analysis showed that lutein enhanced the Bcl-2:Bax ratio, inhibited the expression of caspase-3 and caspase-9, and increased the protein level of phosphorylated Akt. The network pharmacology and molecular docking prediction results suggested that the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway was a potential mechanism of lutein in DE treatment. Furthermore, LY294002, a specific PI3K inhibitor, partially abolished the protective effect of lutein. These results presented that lutein attenuated oxidative damage and apoptosis triggered by MGO in PC12 cells via the PI3K/Akt signaling pathway. PRACTICAL APPLICATIONS: Lutein is a common carotenoid dispersed in fruits and vegetables. This article confirmed a protective effect of lutein on oxidative damage and apoptosis in PC12 cells after MGO damage. These results indicated that lutein could potentially be developed as a nutraceutical or functional food in the prevention of diabetic-related neurodegenerative diseases.

5-aminolevulinic acid and sodium ferrous citrate decreased cell viability of gastric cancer cells by enhanced ROS generation through improving COX activity

BACKGROUND

Mitochondrial dysfunctions are related to cancer development.. 5-aminolevulinic acid (ALA) is used for photodynamic therapy (PDT). In this PDT, protoporphyrin IX (PpIX), which is converted from ALA, can generate reactive oxygen species (ROS) that kill the cancer cell. ALA is also reported to promote cytochrome c oxidase (COX) activity, which can generate ROS itself. Therefore, this study focused on the effect of ALA during PDT. In addition, in the previous study, sodium ferrous citrate (SFC) is reported to increase COX activity. So, this study also aims to improve the COX activity by the addition of SFC that can promote ROS generation, which has a cytotoxic effect.

METHODS

In this study, we used ALA and SFC, then evaluated the effects of the treatment on the human gastric cancer cell line MKN45, including the induction of cell death.

RESULTS

This study showed that treatment with ALA and SFC increases intracellular heme and heme proteins. Moreover, COX activity was promoted, resulting in the production of intracellular reactive oxygen species (ROS), which eventually reduced the cell viability in human gastric cancer cell line MKN45.

CONCLUSION

Our study can detect ROS generation with ALA and SFC. Furthermore, we found this generation of ROS has a cytotoxic effect. Therefore, this phenomenon contributes to the effect of PDT.

A Review on Fucoidan Structure, Extraction Techniques, and Its Role as an Immunomodulatory Agent

Functional ingredients for human health have recently become the focus of research. One such potentially versatile therapeutic component is fucose-containing sulfated polysaccharides (FCSPs), referred to as fucoidans. The exploitation of marine brown algae provides a rich source of FCSPs because of their role as a structural component of the cell wall. Fucoidans are characterized by a sulfated fucose backbone. However, the structural characterization of FCSPs is impeded by their structural diversity, molecular weight, and complexity. The extraction and purification conditions significantly influence the yield and structural alterations. Inflammation is the preliminary response to potentially injurious inducements, and it is of the utmost importance for modulation in the proper direction. Improper manipulation and/or continuous stimuli could have detrimental effects in the long run. The web of immune responses mediated through multiple modulatory/cell signaling components can be addressed through functional ingredients, benefiting patients with no side effects. In this review, we attempted to address the involvement of FCSPs in the stimulation/downregulation of immune response cell signaling. The structural complexity and its foremost influential factor, extraction techniques, have also attracted attention, with concise details on the structural implications of bioactivity.

Effects of hypoxia and reoxygenation on mitochondrial functions and transcriptional profiles of isolated brain and muscle porcine cells

Oxygen fluctuations might occur in mammalian tissues under physiological (e.g. at high altitudes) or pathological (e.g. ischemia-reperfusion) conditions. Mitochondria are the key target and potential amplifiers of hypoxia-reoxygenation (H-R) stress. Understanding the mitochondrial responses to H-R stress is important for identifying adaptive mechanisms and potential therapeutic solutions for pathologies associated with oxygen fluctuations. We explored metabolic response to H-R stress in two tissue types (muscle and brain) with different degrees of hypoxia tolerance in a domestic pig Sus scrofa focusing on the cellular responses independent of the systemic regulatory mechanisms. Isolated cells from the skeletal muscle (masseter) and brain (thalamus) were exposed to acute short-term (15 min) hypoxia followed by reoxygenation. The mitochondrial oxygen consumption, reactive oxygen species (ROS) production rates and transcriptional profiles of hypoxia-responsive mRNA and miRNA were determined. Mitochondria of the porcine brain cells showed a decrease in the resting respiration and ATP synthesis capacity whereas the mitochondria from the muscle cells showed robust respiration and less susceptibility to H-R stress. ROS production was not affected by the short-term H-R stress in the brain or muscle cells. Transcriptionally, prolyl hydroxylase domain protein EGLN3 was upregulated during hypoxia and suppressed during reoxygenation in porcine muscle cells. The decline in EGLN3 mRNA during reoxygenation was accompanied by an upregulation of hypoxia-inducible factor subunit α (HIF1A) transcripts in the muscle cells. However, in the brain cells, HIF1A mRNA levels were suppressed during reoxygenation. Other functionally important transcripts and miRNAs involved in antioxidant response, apoptosis, inflammation, and substrate oxidation were also differentially expressed between the muscle and brain cells. Suppression of miRNA levels during acute intermittent hypoxia was stronger in the brain cells affecting ~ 55% of all studied miRNA transcripts than in the muscle cells (~ 25% of miRNA) signifying transcriptional derepression of the respective mRNA targets. Our study provides insights into the potential molecular and physiological mechanisms contributing to different hypoxia sensitivity of the studied tissues and can serve as a starting point to better understand the biological processes associated with hypoxia stress, e.g. during ischemia and reperfusion.

Sometimes less is more: inhibitory infrared light during early reperfusion calms hyperactive mitochondria and suppresses reperfusion injury

Ischemic stroke affects over 77 million people annually around the globe. Due to the blockage of a blood vessel caused by a stroke, brain tissue becomes ischemic. While prompt restoration of blood flow is necessary to save brain tissue, it also causes reperfusion injury. Mitochondria play a crucial role in early ischemia-reperfusion injury due to the generation of reactive oxygen species (ROS). During ischemia, mitochondria sense energy depletion and futilely attempt to up-regulate energy production. When reperfusion occurs, mitochondria become hyperactive and produce large amounts of ROS which damages neuronal tissue. This ROS burst damages mitochondria and the cell, which results in an eventual decrease in mitochondrial activity and pushes the fate of the cell toward death. This review covers the relationship between the mitochondrial membrane potential (ΔΨm) and ROS production. We also discuss physiological mechanisms that couple mitochondrial energy production to cellular energy demand, focusing on serine 47 dephosphorylation of cytochrome c (Cytc) in the brain during ischemia, which contributes to ischemia-reperfusion injury. Finally, we discuss the use of near infrared light (IRL) to treat stroke. IRL can both stimulate or inhibit mitochondrial activity depending on the wavelength. We emphasize that the use of the correct wavelength is crucial for outcome: inhibitory IRL, applied early during reperfusion, can prevent the ROS burst from occurring, thus preserving neurological tissue.

The power of a novel combined anticancer therapy: challenge and opportunity of micotherapy in the treatment of Glioblastoma Multiforme

Glioblastoma (GBM) is the most common and mortal primary brain tumor in human. After standard therapies, that include surgical resection followed by radiotherapy and chemotherapy, it is difficult to completely remove the tumor and the development of relapses and resistance is almost inevitable. The chemotherapy now available also show important side effects, to overcame those limitation, new platinum-based drugs are being synthetized, Pt(IV)Ac-POA, (OC-6-44)-acetate-diamine-chloride(2-(2-propynyl)octanoato)platinum(IV), a prodrug having an Histone-3-DeAcetylase-Inhibitor as axial ligands, is one of them. Moreover, new compounds of plant origin are increasingly seen as potential sources of benefits in oncological treatments. The aim of the study is to investigate the possible contribution of micotherapy in the fight against GBM, its role in the metabolism of reactive oxygen species (ROS) and its synergic effect with a new platinum-based compound, Pt(IV)Ac-POA, on human glioblastoma U251 cells. Through cytofluorimetric and immunofluorescence analysis, the ability of the micotherapy in study to regulate the cell cycle was assessed, and its importance in controlling the cellular redox state was also revealed, opening to the possibility of a new therapy in which micotherapy can support the activity of new chemotherapy while reducing its side effects controlling inflammatory conditions in the microenvironment. Additionally, the combined therapy appeared able to induce regulated form of necrosis, such as ferroptosis, and to hinder the establishment of resistance mechanisms.

Activating Hypoxia-Inducible Factor-1α Reduces Myocardial Ischemia-Reperfusion Injury in Mice Through Hexokinase II

To verify that HIF-1α/HKII pathway is the key mechanism to alleviate myocardial ischemiareperfusion (IR) injury in aged mice through HIF-1α and HKII inhibitors. A mouse I/R model was carried out in young and old C57BL/6 mice for 60 min and reperfusion for 120 min. Mice were injected intraperitoneally with AAV-9 virus to introduce HIF-1α 24 h before ischemia. After 2 h of reperfusion, the mitochondrial ultrastructure, ATP content, membrane potential, and protein expression of HIF-1α, LC3, Bax, Bcl-2, Caspese-9, Caspase-3, and Cyt-3 were detected. After 24 h, the myocardial infarction area and cardiac ability were evaluated. Young mice and old mice have different protective effects after acute ischemia/reperfusion injury. After the introduction of HIF-1α by AAV-9 virus, the expression of the downstream target gene HKII can be up-regulated. At the same time, it reduces the expression of key proteins LC3, Bax, Caspese-9, and Caspase-3. Stabilize the membrane potential, ultimately reduce the area of myocardial infarction and improve heart function. Young mice and old mice have different protective effects after acute ischemia/reperfusion injury. The I/R in the older is caused by HIF-1α. HIF-1α inhibits the opening of mPTP by up-regulating HKII, stabilizes mitochondrial membrane potential, protects mitochondrial integrity, and reduces myocardial ischemia-reperfusion damage to the myocardium of elderly mice.

Nicotinamide mononucleotide ameliorates acute lung injury by inducing mitonuclear protein imbalance and activating the UPRmt

Mitochondria need to interact with the nucleus under homeostasis and stress to maintain cellular demands and nuclear transcriptional programs. Disrupted mitonuclear interaction is involved in many disease processes. However, the role of mitonuclear signaling regulators in endotoxin-induced acute lung injury (ALI) remains unknown. Nicotinamide adenine dinucleotide (NAD⁺) is closely related to mitonuclear interaction with its central role in mitochondrial metabolism. In the current study, C57BL/6J mice were administrated with lipopolysaccharide 15 mg/kg to induce endotoxin-induced ALI and investigated whether the NAD⁺ precursor nicotinamide mononucleotide (NMN) could preserve mitonuclear interaction and alleviate ALI. After pretreatment with NMN for 7 days, NAD⁺ levels in the mitochondrial, nucleus, and total intracellular were significantly increased in endotoxemia mice. Moreover, supplementation of NMN alleviated lung pathologic injury, reduced ROS levels, increased MnSOD activities, mitigated mitochondrial dysfunction, ameliorated the defects in the nucleus morphology, and these cytoprotective effects were accompanied by preserving mitonuclear interaction (including mitonuclear protein imbalance and the mitochondrial unfolded protein response, UPR^mt). Furthermore, NAD⁺-mediated mitonuclear protein imbalance and UPR^mt are probably regulated by deacetylase Sirtuin1 (SIRT1). Taken together, our results indicated that NMN pretreatment ameliorated ALI by inducing mitonuclear protein imbalance and activating the UPR^mt in an SIRT1-dependent manner.

Evaluation of mRNA expression level of the ATP synthase membrane subunit c locus 1 (ATP5G1) gene in patients with schizophrenia

Background

Schizophrenia is a serious, complex mental disorder. The impairment of oxidative phosphorylation has a detrimental consequence on CNS function. Different ATP synthase subunits have been involved in the pathological process of various neurodegenerative disorders. Our goal was to evaluate the mRNA expression level of the ATP synthase membrane subunit c locus 1 (ATP5G1, also named ATP5MC1) gene in patients with schizophrenia.

Methods

Determination of the expression levels of ATP5G1 in plasma and peripheral blood mononuclear cells (PBMCs) were performed by real-time PCR in 90 controls and 90 patients with schizophrenia.

Results

Patients had significantly decreased ATP5G1 mRNA expression levels in both plasma and PBMCs compared to controls. The receiver operating characteristic curve was applied to detect a cut-off value of ATP5G1 expression in plasma and PBMCs. The ATP5G1 relative expression in PBMCs had better performance with a cut-off value ≤ 21 (AUC = 0.892, P < 0.001), sensitivity of 94.44%, and specificity of 72.22% in discriminating between schizophrenic patients. ATP5G1 expression in PBMCs was an independent predictor in schizophrenia.

Conclusion

This study revealed a down-regulation of ATP5G1 expression in schizophrenia, precisely expression in PBMCs. That might give insight into the role of ATP5G1 gene in the pathogenesis of schizophrenia.

•

This study revealed a down-regulation of ATP5G1 expression in schizophrenia, precisely expression in PBMCs, which was found as an independent risk factor.

•

This might give insight into the role of the ATP5G1 gene in the pathogenesis of schizophrenia.

•

Further studies are needed to evaluate the role of ATP5G1 in schizophrenia and their impact on ATP production in these patients.

Pentacyclic triterpenoid ursolic acid induces apoptosis with mitochondrial dysfunction in adult T-cell leukemia MT-4 cells to promote surrounding cell growth

We investigated the antitumor effects of oleanolic acid (OA) and ursolic acid (UA) on adult T-cell leukemia cells. OA and UA dose-dependently inhibited the proliferation of adult T-cell leukemia cells. UA-treated cells showed caspase 3/7 and caspase 9 activation. PARP cleavage was detected in UA-treated MT-4 cells. Activation of mTOR and PDK-1 was inhibited by UA. Autophagosomes were detected in MT-4 cells after UA treatment using electron microscopy. Consistently, mitophagy was observed in OA- and UA-treated MT-4 cells by confocal microscopy. The mitochondrial membrane potential in MT-4 cells considerably decreased, and mitochondrial respiration and aerobic glycolysis were significantly reduced following UA treatment. Furthermore, MT-1 and MT-4 cells were sorted into two regions based on their mitochondrial membrane potential. UA-treated MT-4 cells from both regions showed high activation of caspase 3/7, which were inhibited by Z-vad. Interestingly, MT-4 cells cocultured with sorted UA-treated cells showed enhanced proliferation. Finally, UA induced cell death and ex vivo PARP cleavage in peripheral blood mononuclear cells from patients with adult T-cell leukemia. Therefore, UA-treated MT-4 cells show caspase activation following mitochondrial dysfunction and may produce survival signals to the surrounding cells.

Schizophrenia: a disorder of broken brain bioenergetics

A substantial and diverse body of literature suggests that the pathophysiology of schizophrenia is related to deficits of bioenergetic function. While antipsychotics are an effective therapy for the management of positive psychotic symptoms, they are not efficacious for the complete schizophrenia symptom profile, such as the negative and cognitive symptoms. In this review, we discuss the relationship between dysfunction of various metabolic pathways across different brain regions in relation to schizophrenia. We contend that several bioenergetic subprocesses are affected across the brain and such deficits are a core feature of the illness. We provide an overview of central perturbations of insulin signaling, glycolysis, pentose-phosphate pathway, tricarboxylic acid cycle, and oxidative phosphorylation in schizophrenia. Importantly, we discuss pharmacologic and nonpharmacologic interventions that target these pathways and how such interventions may be exploited to improve the symptoms of schizophrenia.

An elemental diet protects mouse salivary glands from 5‑fluorouracil‑induced atrophy

An elemental diet (ED) reduces adverse effects of chemotherapy, including oral mucositis, in patients with cancer. However, the detailed mechanism(s) of the healing effects of an ED remains unclear. In the present study, the protective effects of the ED, Elental^®, were examined against 5-fluorouracil (5-FU)-induced oral mucositis and salivary gland atrophy in mice. Mucositis was induced in female ICR mice by injection of 5-FU. The mice were orally administered Elental^® (ED group) or saline (control group). After treatment, the mice body weight, salivary gland weight and the histological changes in the salivary gland granular duct area were monitored. The mice body weight remained stable in the ED group, but was significantly decreased in the control group. Moreover, the salivary gland weight was higher in the ED group compared with the control group. In addition, the salivary gland granular duct area cells were larger in the ED group compared with the control group. Whole transcriptome analysis and network analysis were conducted to understand the mechanisms of action of Elental^® against oral mucositis. Whole transcriptome analysis and Ingenuity Pathways Analysis data suggested that Elental^® contributed to the recovery of mitochondrial function in 5-FU-damaged salivary glands. Immunohistochemical analysis of salivary gland tissue demonstrated that the expression of cytochrome c oxidase subunit 4 and epidermal growth factor were higher in the ED group compared with the control group. Next, the rate of apoptosis in the salivary glands was examined using terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assays. The number of TUNEL-positive cells in the salivary glands was lower in the ED group compared with the control group. These findings suggested that Elental^® may protect mouse salivary glands from 5-FU-induced atrophic changes, which suggests that ED treatment may improve xerostomia and alleviate oral mucositis in patients with cancer receiving 5-FU-based chemotherapy.

Tricyclodecan-9-yl-Xanthogenate (D609): Mechanism of Action and Pharmacological Applications

Tricyclodecan-9-yl xanthogenate (D609) is a synthetic tricyclic compound possessing a xanthate group. This xanthogenate compound is known for its diverse pharmacological properties. Over the last three decades, many studies have reported the biological activities of D609, including antioxidant, antiapoptotic, anticholinergic, anti-tumor, anti-inflammatory, anti-viral, anti-proliferative, and neuroprotective activities. Its mechanism of action is extensively attributed to its ability to cause the competitive inhibition of phosphatidylcholine (PC)-specific phospholipase C (PC-PLC) and sphingomyelin synthase (SMS). The inhibition of PCPLC or SMS affects secondary messengers with a lipidic nature, i.e., 1,2-diacylglycerol (DAG) and ceramide. Various in vitro/in vivo studies suggest that PCPLC and SMS inhibition regulate the cell cycle, block cellular proliferation, and induce differentiation. D609 acts as a pro-inflammatory cytokine antagonist and diminishes Aβ-stimulated toxicity. PCPLC enzymatic activity essentially requires Zn2+, and D609 might act as a potential chelator of Zn2+, thereby blocking PCPLC enzymatic activity. D609 also demonstrates promising results in reducing atherosclerotic plaque formation, post-stroke cerebral infarction, and cancer progression. The present compilation provides a comprehensive mechanistic insight into D609, including its chemistry, mechanism of action, and regulation of various pharmacological activities.

Time-of-Day Circadian Modulation of Grape-Seed Procyanidin Extract (GSPE) in Hepatic Mitochondrial Dynamics in Cafeteria-Diet-Induced Obese Rats

Major susceptibility to alterations in liver function (e.g., hepatic steatosis) in a prone environment due to circadian misalignments represents a common consequence of recent sociobiological behavior (i.e., food excess and sleep deprivation). Natural compounds and, more concisely, polyphenols have been shown as an interesting tool for fighting against metabolic syndrome and related consequences. Furthermore, mitochondria have been identified as an important target for mediation of the health effects of these compounds. Additionally, mitochondrial function and dynamics are strongly regulated in a circadian way. Thus, we wondered whether some of the beneficial effects of grape-seed procyanidin extract (GSPE) on metabolic syndrome could be mediated by a circadian modulation of mitochondrial homeostasis. For this purpose, rats were subjected to “standard”, “cafeteria” and “cafeteria diet + GSPE” treatments (n = 4/group) for 9 weeks (the last 4 weeks, GSPE/vehicle) of treatment, administering the extract/vehicle at diurnal or nocturnal times (ZT0 or ZT12). For circadian assessment, one hour after turning the light on (ZT1), animals were sacrificed every 6 h (ZT1, ZT7, ZT13 and ZT19). Interestingly, GSPE was able to restore the rhythm on clock hepatic genes (Bmal1, Per2, Cry1, Rorα), as this correction was more evident in nocturnal treatment. Additionally, during nocturnal treatment, an increase in hepatic fusion genes and a decrease in fission genes were observed. Regarding mitochondrial complex activity, there was a strong effect of cafeteria diet at nearly all ZTs, and GSPE was able to restore activity at discrete ZTs, mainly in the diurnal treatment (ZT0). Furthermore, a differential behavior was observed in tricarboxylic acid (TCA) metabolites between GSPE diurnal and nocturnal administration times. Therefore, GSPE may serve as a nutritional preventive strategy in the recovery of hepatic-related metabolic disease by modulating mitochondrial dynamics, which is concomitant to the restoration of the hepatic circadian machinery.