PGC-1α-Mediated Mitochondrial Quality Control: Molecular Mechanisms and Implications for Heart Failure

Mitochondria-derived vesicles: A promising and potential target for tumour therapy

Mitochondria-derived vesicles (MDVs) participate in early cellular defence mechanisms initiated in response to mitochondrial damage. They maintain mitochondrial quality control (MQC) by clearing damaged mitochondrial components, thereby ensuring the normal functioning of cellular processes. This process is crucial for cell survival and health, as mitochondria are the energy factories of cells, and their damage can cause cellular dysfunction and even death. Recent studies have shown that MDVs not only maintain mitochondrial health but also have a significant impact on tumour progression. MDVs selectively encapsulate and transport damaged mitochondrial proteins under oxidative stress and reduce the adverse effects of mitochondrial damage on cells, which may promote the survival and proliferation of tumour cells. Furthermore, it has been indicated that after cells experience mild stress, the number of MDVs significantly increases within 2-6 h, whereas mitophagy, a process of clearing damaged mitochondria, occurs 12-24 h later. This suggests that MDVs play a critical role in the early stress response of cells. Moreover, MDVs also have a significant role in intercellular communication, specifically in the tumour microenvironment. They can carry and transmit various bioactive molecules, such as proteins, nucleic acids, and lipids, which regulate tumour cell's growth, invasion, and metastasis. This intercellular communication may facilitate tumour spread and metastasis, making MDVs a potential therapeutic target. Advances in MDV research have identified novel biomarkers, clarified regulatory mechanisms, and provided evidence for clinical use. These breakthroughs pave the way for novel MDV-targeted therapies, offering improved treatment alternatives for cancer patients. Further research can identify MDVs' role in tumour development and elucidate future cancer treatment horizons.

Chronic stress elicits sex-specific mitochondrial respiratory functional changes in the rat heart

Although chronic psychosocial stress is linked to cardiovascular diseases, the underlying mechanisms remain elusive. For this study, we focused on the mitochondrion as a putative mediator of stress-related cardiac pathologies in a sex-dependent manner. Male and female Wistar rats were subjected to chronic stress for 4 weeks (mimicking an anxious phenotype) versus matched controls. Cardiac redox status, mitochondrial respiration parameters, and expression levels of proteins involved in mitochondrial oxidative phosphorylation, dynamics, and biogenesis were evaluated. Despite limited changes in behavior and circulating stress hormones (both sexes), stressed males exhibited altered cardiac oxidative phosphorylation via β-oxidation- and glucose oxidation-linked respiratory pathways together with increased myocardial antioxidant capacity and decreased lipid peroxidation. Conversely, stressed females exhibited a protective and resilient phenotype by displaying augmented levels of major mitochondrial respiratory complexes (complex I, III, and ATP synthase) and a fusion marker (mitofusin-2 [Mfn2]), together with attenuated expression of a fission marker (dynamin-related protein-1 [Drp1]) despite decreased estradiol levels. In contrast, stressed males displayed increased cardiac ATP synthase levels together with diminished peroxisome proliferator-activated receptor-gamma coactivator-1-alpha (PGC-1α) expression versus controls. These findings indicate that male mitochondria are more prone to stress-related functional changes, while females exhibited a more protective and resilient phenotype.

Exosome-Mediated Mitochondrial Regulation: A Promising Therapeutic Tool for Alzheimer's Disease and Parkinson's Disease

Alzheimer's disease (AD) and Parkinson's disease (PD) are representative neurodegenerative diseases with abnormal energy metabolism and altered distribution and deformation of mitochondria within neurons, particularly in brain regions such as the hippocampus and substantia nigra. Neurons have high energy demands; thus, maintaining a healthy mitochondrial population is important for their biological function. Recently, exosomes have been reported to have mitochondrial regulatory potential and antineurodegenerative properties. This review presents the mitochondrial abnormalities in brain cells associated with AD and PD and the potential of exosomes to treat these diseases. Specifically, it recapitulates research on the molecular mechanisms whereby exosomes regulate mitochondrial biogenesis, fusion/fission dynamics, mitochondrial transport, and mitophagy. Furthermore, this review discusses exosome-triggered signaling pathways that regulate nuclear factor (erythroid-derived 2)-like 2-dependent mitochondrial antioxidation and hypoxia inducible factor 1α-dependent metabolic reprogramming. In summary, this review aims to provide a profound understanding of the regulatory effect of exosomes on mitochondrial function in neurons and to propose exosome-mediated mitochondrial regulation as a promising strategy for AD and PD.

Ameliorating effect of the aldose reductase inhibitor 1-Acetyl-5-phenyl-1 H-pyrrol-3-ylacetate on galactose-induced cataract

Diabetes mellitus, as a common chronic disease, easily leads to significant changes in the structure of the eye, among which diabetic cataract is particularly common. Although surgery is the main treatment for this complication, it may be accompanied by postoperative complications. Therefore, it is particularly important to develop specific drugs for diabetic cataract, aiming to fundamentally reduce its incidence and reduce the need for surgery. At present, the greatest challenge is to develop therapeutic agents with multiple synergistic effects based on the complex pathogenesis of cataract. 1-Acetyl-5-phenyl-1 H-pyrrol-3-ylacetate (APPA) is designed based on the pathological mechanism as a potential drug to alleviate the occurrence of diabetic cataract. Our observations suggest that APPA is more effective than bendazaclysine in alleviating high galactose-induced oxidative stress (The malondialdehyde content in the APPA group and bendazaclysine group was significantly reduced to 0.45-fold and 0.58-fold compared to the high galactose-induced group, respectively.) and apoptosis (The apoptosis rate in the APPA group and bendazaclysine group was significantly reduced to 0.28-fold and 0.35-fold compared to the high galactose-induced group, respectively.) in lens epithelial cells by increasing antioxidant enzyme activity, and restoring mitochondrial homeostasis. Mechanistic studies have shown that APPA restoration of mitochondrial homeostasis is mediated through the SIRT1-PGC-1α pathway. In the galactose-induced cataract rat model, APPA is effective in alleviating the occurrence of galactose-induced cataract. In conclusion, APPA with multiple synergistic functions may be a potential drug to alleviate the occurrence of diabetic cataract, and it has a wider range of indications than benzydalysine.

Reactive Oxygen Species as a Common Pathological Link Between Alcohol Use Disorder and Alzheimer's Disease with Therapeutic Implications

Chronic alcohol consumption leads to excessive production of reactive oxygen species (ROS), driving oxidative stress that contributes to both alcohol use disorder (AUD) and Alzheimer's disease (AD). This review explores how ROS-mediated mitochondrial dysfunction and neuroinflammation serve as shared pathological mechanisms linking these conditions. We highlight the role of alcohol-induced oxidative damage in exacerbating neurodegeneration and compare ROS-related pathways in AUD and AD. Finally, we discuss emerging therapeutic strategies, including mitochondrial antioxidants and inflammasome inhibitors, that target oxidative stress to mitigate neurodegeneration. Understanding these overlapping mechanisms may provide new insights for preventing and treating ROS-driven neurodegenerative disorders.

Antioxidant and Anti-Inflammatory Defenses in Huntington's Disease: Roles of NRF2 and PGC-1α, and Therapeutic Strategies

Huntington's disease (HD) is a detrimental neurodegenerative disease caused by the expansion of a CAG triplet in the HTT gene. This mutation leads to the production of mutant Huntingtin (Htt) protein with toxic gain-of-function. The mHtt is responsible in several ways for the establishment of an intricate pathogenetic scenario in affected cells, particularly in HD neurons. Among the features of HD, oxidative stress plays a relevant role in the progression of the disease at the cellular level. Mitochondrial dysfunction, bioenergetic deficits, Reactive Oxygen Species (ROS) production, neuroinflammation, and general reduction of antioxidant levels are all involved in the promotion of a toxic oxidative environment, eventually causing cell death. Nonetheless, neuronal cells exert antioxidant molecules to build up defense mechanisms. Key components of these defensive mechanisms are the nuclear factor erythroid 2-related factor 2 (NRF2) and peroxisome proliferator-activated receptor gamma coactivator-1 α (PGC-1α). Thus, this review aims to describe the involvement of oxidative stress in HD by exploring the roles of NRF2 and PGC-1α, crucial actors in this play. Finally, antioxidant therapeutic strategies targeting such markers are discussed.

Mitochondrial-based therapies for neurodegenerative diseases: a review of the current literature

Neurodegenerative disorders present significant challenges to modern medicine because of their complex etiology, pathogenesis, and progressive nature, which complicate practical treatment approaches. Mitochondrial dysfunction is an important contributor to the pathophysiology of various neurodegenerative illnesses, including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). This review paper examines the current literature highlighting the multifaceted functions of mitochondria, including energy production, calcium signaling, apoptosis regulation, mitochondrial biogenesis, mitochondrial dynamics, axonal transport, endoplasmic reticulum-mitochondrial interactions, mitophagy, mitochondrial proteostasis, and their crucial involvement in neuronal health. The literature emphasizes the increasing recognition of mitochondrial dysfunction as a critical factor in the progression of neurodegenerative disorders, marking a shift from traditional symptom management to innovative mitochondrial-based therapies. By discussing mitochondrial mechanisms, including mitochondrial quality control (MQC) processes and the impact of oxidative stress, this review highlights the need for novel therapeutic strategies to restore mitochondrial function, protect neuronal connections and integrity, and slow disease progression. This comprehensive review aims to provide insights into potential interventions that could transform the treatment landscape for neurodegenerative diseases, addressing symptoms and underlying pathophysiological changes.

Metabolic and Mitochondrial Dysregulations in Diabetic Cardiac Complications

The growing prevalence of diabetes highlights the urgent need to study diabetic cardiovascular complications, specifically diabetic cardiomyopathy, which is a diabetes-induced myocardial dysfunction independent of hypertension or coronary artery disease. This review examines the role of mitochondrial dysfunction in promoting diabetic cardiac dysfunction and highlights metabolic mechanisms such as hyperglycaemia-induced oxidative stress. Chronic hyperglycaemia and insulin resistance can activate harmful pathways, including advanced glycation end-products (AGEs), protein kinase C (PKC) and hexosamine signalling, uncontrolled reactive oxygen species (ROS) production and mishandling of Ca2+ transient. These processes lead to cardiomyocyte apoptosis, fibrosis and contractile dysfunction. Moreover, endoplasmic reticulum (ER) stress and dysregulated RNA-binding proteins (RBPs) and extracellular vesicles (EVs) contribute to tissue damage, which drives cardiac function towards heart failure (HF). Advanced patient-derived induced pluripotent stem cell (iPSC) cardiac organoids (iPS-COs) are transformative tools for modelling diabetic cardiomyopathy and capturing human disease's genetic, epigenetic and metabolic hallmarks. iPS-COs may facilitate the precise examination of molecular pathways and therapeutic interventions. Future research directions encourage the integration of advanced models with mechanistic techniques to promote novel therapeutic strategies.

Extracellular PHF-tau modulates astrocyte mitochondrial dynamics and mediates neuronal connectivity

BACKGROUND

Tau is an intracellular protein that plays a crucial role in stabilizing microtubules. However, it can aggregate into various forms under pathological conditions and be secreted into the brain parenchyma. While the consequences of tau aggregation within neurons have been extensively studied, the effects of extracellular paired helical filaments of tau (ePHF-tau) on neurons and astrocytes are still poorly understood.

METHODS

This study examined the effect of human ePHF-tau (2N4R) on primary cultures of rat neuroglia, focusing on changes in neurites or synapses by microscopy and analysis of synaptosome and mitochondria proteomic profiles after treatment. In addition, we monitored the behavior of mitochondria in neurons and astrocytes separately over three days using high-speed imaging and high-throughput acquisition and analysis.

RESULTS

ePHF-tau was efficiently cleared by astrocytes within two days in a 3D neuron-astrocyte co-culture model. Treatment with ePHF-tau led to a rapid increase in synaptic vesicle production and active zones, suggesting a potential excitotoxic response. Proteomic analyses of synaptosomal and mitochondrial fractions revealed distinct mitochondrial stress adaptations: astrocytes exhibited elevated mitochondrial biogenesis and turnover, whereas neuronal mitochondria displayed only minor oxidative modifications. In a mixed culture model, overexpression of tau 1N4R specifically in astrocytes triggered a marked increase in mitochondrial biogenesis, coinciding with enhanced synaptic vesicle formation in dendrites. Similarly, astrocyte-specific overexpression of PGC1alpha produced a comparable pattern of synaptic vesicle production, indicating that astrocytic mitochondrial adaptation to ePHF-tau may significantly influence synaptic function.

CONCLUSIONS

These findings suggest that the accumulation of PHF-tau within astrocytes drives changes in mitochondrial biogenesis, which may influence synaptic regulation. This astrocyte-mediated adaptation to tauopathy highlights the potential role of astrocytes in modulating synaptic dynamics in response to tau stress, opening avenues for therapeutic strategies aimed at astrocytic mechanisms in the context of neurodegenerative diseases.

Comprehensive promotion of iPSC-CM maturation by integrating metabolic medium with nanopatterning and electrostimulation

The immaturity of human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) is a major limitation for their use in drug screening to identify pro-arrhythmogenic or cardiotoxic molecules. Here, we demonstrate an approach that combines lipid-enriched maturation medium with a high concentration of calcium, nanopatterning of culture surfaces and electrostimulation to generate iPSC-CMs with advanced electrophysiological, structural and metabolic phenotypes. Systematic testing reveals that electrostimulation is the key driver of enhanced mitochondrial development and metabolic maturation and improved electrophysiological properties of iPSC-CMs. Increased calcium concentration strongly promotes electrophysiological maturation, while nanopatterning primarily facilitates sarcomere organisation with minor effect on electrophysiological properties. Transcriptome analysis reveals that activation of HMCES and TFAM targets contributes to mitochondrial development, whereas downregulation of MAPK/PI3K and SRF targets is associated with iPSC-CM polyploidy. These findings provide mechanistic insights into iPSC-CM maturation, paving the way for pharmacological responses that more closely resemble those of adult CMs.

Importance of systemic redox homeostasis biomarkers and transcription factors in patients undergoing open-heart surgery with cardiopulmonary bypass

PURPOSE

Patients undergoing coronary artery bypass graft surgery and isolated valve disease surgery may experience redox dyshomeostasis associated with cardiopulmonary bypass (CPB).

METHODS

We investigated the impact of CPB on systemic redox homeostasis by analyzing redox biomarkers and antioxidant transcription factors preoperatively and postoperatively using spectrophotometric and immunochemical methods.

RESULTS

Our findings indicate significant variations in protein oxidation biomarkers, antioxidant capacity biomarkers, and transcription coactivator peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) levels after CPB. The ROC analysis indicated that protein carbonyl was valuable in the preoperative (p = 0.009) and postoperative (p = 0.013) periods. We also found that glutathione peroxidase was a valuable redox biomarker during the postoperative period (p = 0.000). An ROC analysis of catalase activity (p = 0.017) before CPB indicated the importance of catalase in eliminating increased hydroperoxide load. The ROC graphs reinforced the value of PGC-1α (p = 0.000) as a biomarker, showing a similar trend to that of catalase before CPB.

CONCLUSION

The earlier view of "increased oxidative stress and decreased biofunction" has shifted to exploring the physiological role of redox signaling regulation. We believe that future studies on the effects of CPB on systemic redox regulation processes through redox signaling mechanisms will significantly contribute to the relevant literature.

Oxidative phosphorylation and breast cancer progression: insights into PGC-1α's role in mitochondrial function

Breast cancer still ranks high as a leading cause of mortality in women due to its complex relationship with metabolic reprogramming and tumor progression. The peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), a key transcriptional coactivator regulating mitochondrial biogenesis and oxidative phosphorylation (OXPHOS), plays a dual role in breast cancer metabolism. On the one hand, PGC-1α enhances mitochondrial function and energy production, facilitating tumor survival and metastasis, particularly in hypoxic environments. On the other hand, its suppression can limit tumor aggressiveness and energy metabolism. This dual functionality underscores its context-dependent role in cancer progression, where its activation or inhibition varies across tumor subtypes and microenvironmental conditions. The purpose of this review is to provide a comprehensive understanding of PGC-1α's dual roles in breast cancer, elucidating its regulation of mitochondrial function, its contribution to tumor progression, and the therapeutic implications of targeting this key metabolic regulator.

A Novel Polysaccharide From Tremella fuciformis Alleviated High-Fat Diet-Induced Obesity by Promoting AMPK/PINK1/PRKN-Mediated Mitophagy in Mice

SCOPE

Polysaccharides from Tremella fuciformis have gained significant interest due to their diverse biological activities. This study focuses on characterizing a purified polysaccharide, TPSP2, extracted from T. fuciformis and evaluating its antiobesity effect and underlying mechanisms in vivo.

METHODS AND RESULTS

Structural analysis revealed that TPSP2, with a molecular weight of 1.51 × 103 kDa, is composed of mannose, rhamnose, glucuronic acid, galactose, xylose, arabinose, and fucose in specific molar ratios. The primary linkages identified include t-Fuc(p), 1,2-Xyl(p), t-GlcA(p), 1,3-Man(p), and 1,2,3-Man(p), with their corresponding ratios being 12.987%, 11.404%, 16.050%, 16.527%, and 26.624%, respectively. In vivo experiments demonstrated that TPSP2 significantly alleviated high-fat diet-induced weight gain, hyperlipidemia, hepatic steatosis, hyperglycemia, and insulin resistance in mice. Mechanistically, TPSP2 was found to enhance AMPK/PINK1-PRKN-dependent mitophagy by upregulating the p-AMPK/AMPK ratio, LC3-II/I ratio, and expression of PINK1, PRKN, prohibitin 2 (PHB2), and LAMP2, while downregulating p62 and TOM20 expression.

CONCLUSION

This study suggested that TPSP2 could be a promising candidate for addressing obesity-related metabolic disorders by targeting mitochondrial quality control mechanisms.

Role of Mitochondrial Dynamics in Skin Homeostasis: An Update

Skin aging is the most prominent phenotype of host aging and is the consequence of a combination of genes and environment. Improving skin aging is essential for maintaining the healthy physiological function of the skin and the mental health of the human body. Mitochondria are vital organelles that play important roles in cellular mechanisms, including energy production and free radical balance. However, mitochondrial metabolism, mitochondrial dynamics, biogenesis, and degradation processes vary greatly in various cells in the skin. It is well known that mitochondrial dysfunction can promote the aging and its associated diseases of the skin, resulting in the damage of skin physiology and the occurrence of skin pathology. In this review, we summarize the important role of mitochondria in various skin cells, review the cellular responses to vital steps in mitochondrial quality regulation, mitochondrial dynamics, mitochondrial biogenesis, and mitochondrial phagocytosis, and describe their importance and specific pathways in skin aging.

Enhanced Parkin-mediated mitophagy mitigates adverse left ventricular remodelling after myocardial infarction: role of PR-364

BACKGROUND AND AIMS

Almost 30% of survivors of myocardial infarction (MI) develop heart failure (HF), in part due to damage caused by the accumulation of dysfunctional mitochondria. Organelle quality control through Parkin-mediated mitochondrial autophagy (mitophagy) is known to play a role in mediating protection against HF damage post-ischaemic injury and remodelling of the subsequent deteriorated myocardium.

METHODS

This study has shown that a single i.p. dose (2 h post-MI) of the selective small molecule Parkin activator PR-364 reduced mortality, preserved cardiac ejection fraction, and mitigated the progression of HF. To reveal the mechanism of PR-364, a multi-omic strategy was deployed in combination with classical functional assays using in vivo MI and in vitro cardiomyocyte models.

RESULTS

In vitro cell data indicated that Parkin activation by PR-364 increased mitophagy and mitochondrial biogenesis, enhanced adenosine triphosphate production via improved citric acid cycle, altered accumulation of calcium localization to the mitochondria, and initiated translational reprogramming with increased expression of mitochondrial translational proteins. In mice, PR-364 administered post-MI resulted in widespread proteome changes, indicating an up-regulation of mitochondrial metabolism and mitochondrial translation in the surviving myocardium.

CONCLUSIONS

This study demonstrates the therapeutic potential of targeting Parkin-mediated mitophagy using PR-364 to protect surviving cardiac tissue post-MI from progression to HF.

PPARGC1A regulates transcriptional control of mitochondrial biogenesis in early bovine embryos

Extensive mitochondrial replication during oogenesis and its role in oocyte maturation and fertilization indicate that the amount of mitochondrial DNA (mtDNA) may play a significant role in early embryonic development. Early embryos express peroxisome proliferator-activated receptor gamma co-activator alpha (PPARGC1A/PGC-1a), a protein essential for mitochondrial biogenesis. This study investigated the role of PGC-1α from a single-cell zygotic stage to day-8 bovine blastocyst and the effect of PGC-1a knockdown (KD) on embryo mitochondria and development. PGC-1α KD via siRNA injection into single-cell zygotes does not substantially affect embryonic cleavage up to the morula stage but considerably reduces blastocyst development (18.42%) and hatching than the control (32.81%). PGC-1α regulates transcription of the gene encoding mitochondrial transcription factor A (TFAM), and immunofluorescence analysis indicated significantly lower TFAM expression in the 16-cell KD embryos and day-8 KD blastocysts. Reduction in NRF1 protein's nuclear localization in bovine blastomeres was also observed in PGC-1α-KD embryos. Furthermore, to understand the effect of PGC-1α-KD on the mitochondrial genome, we found a low mtDNA copy number in PGC-1α-KD day-8 bovine blastocysts. Several genes related to mitochondrial functioning, like ND1, ND3, ND5, ATPase8, COI, COII, and CYTB, were significantly downregulated in PGC-1α-KD embryos. Moreover, high mitochondrial depolarization (ΔΨm) and abnormal lipid depositions were observed in the PGC-1α KD blastocysts. SIRT1 is the upstream regulator of PGC-1α, but SIRT1 activation via Hesperetin does not affect PGC-1α-KD embryonic development considerably. In conclusion, PGC-1α plays a critical role in early embryo mitochondrial functioning, and any perturbation in its expression significantly disrupts early embryonic development.

Metrnl and Cardiomyopathies: From Molecular Mechanisms to Therapeutic Insights

Cardiomyopathies, a diverse group of diseases affecting the heart muscle, continue to pose significant clinical challenges due to their complex aetiologies and limited treatment options targeting underlying genetic and molecular dysregulations. Emerging evidence indicates that Metrnl, a myokine, adipokine and cardiokine, plays a significant role in the pathogenesis of various cardiomyopathies. Therefore, the objective of this review is to examine the role and mechanism of Metrnl in various cardiomyopathies, with the expectation of providing new insights for the treatment of these diseases.

Long-term taurine supplementation regulates brain mitochondrial dynamics in mice

BACKGROUND

Taurine (TAU) is the most abundant non-protein amino acid in the central nervous system (CNS). However, the molecular mechanism of TAU in the CNS is still poorly understood. Meanwhile, disruption in mitochondrial dynamics is evident in CNS disorders. This study aimed to investigate the effect of TAU on mitochondrial dynamics.

METHODS

TAU (0.25, 0.5 and 1% in drinking water) was administered to young mice for six months. Several memory/cognition parameters and indices of anxiety/depression were assessed. Meanwhile, various mitochondrial indices and the expression/activity of genes involved in mitochondrial biogenesis and dynamics (Akt, CREB, NRF1, TFAM, PGC-1α, Mfn1, Mfn2, UCP2, PINK1, OPA1, Drp1 and Fis1) were examined.

RESULTS

TAU significantly enhanced memory performance, suppressed anxiety and depression-like behaviour, increased mitochondrial biogenesis/dynamics and improved mitochondrial indices. It should be mentioned that there was no significant difference between different concentrations of TAU in changing most brain mitochondrial dynamic biomarkers in the current study.

CONCLUSIONS

These findings offer more insights into the molecular mechanism for TAU's action in the CNS. However, there is a need for further research to confirm these effects in humans. Overall, this study suggests the potential application of TAU in various neurological disorders and the need for clinical studies on the effects of this amino acid in the brain.

Mechanistic Insights on Cardioprotective Properties of Ursolic Acid: Regulation of Mitochondrial and Non-mitochondrial Pathways

Ursolic acid, a natural pentacyclic triterpenoid compound, has been shown to have significant cardioprotective effects in various preclinical studies. This article reviews the various mechanisms by which ursolic acid achieves its cardioprotective effects, highlighting its potent anti-oxidant, anti-inflammatory, and anti- apoptotic properties. Ursolic acid upregulates anti-oxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GPx), effectively reducing oxidative stress, thereby decreasing reactive oxygen species (ROS) and improving lipid peroxidation levels. Furthermore, ursolic acid downregulates pro-inflammatory cytokines and inhibits key inflammatory pathways, such as nuclear factor kappa B (NF-κB), which results in its anti-inflammatory effects. These actions help in protecting cardiac tissues from acute and chronic inflammation. Ursolic acid also promotes mitochondrial function and energy metabolism by enhancing mitochondrial biogenesis and reducing dysfunction, which is critical during ischemia-reperfusion (I/R) injury. Additionally, ursolic acid influences multiple molecular pathways, including B-cell leukemia/lymphoma 2 protein (Bcl- 2)/Bcl-2 associated x-protein (Bax), miR-21/extracellular signal-regulated kinase (ERK), and phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt), to reduce cardiomyocyte apoptosis. Collectively, these properties make ursolic acid a promising therapeutic agent for cardiovascular diseases (CVDs), warranting further research and clinical trials to harness its potential fully.

Peroxisome proliferator‑activated receptor γ coactivator‑1α in heart disease (Review)

Heart disease (HD) is a general term for various diseases affecting the heart. An increasing body of evidence suggests that the pathogenesis of HD is closely related to mitochondrial dysfunction. Peroxisome proliferator‑activated receptor γ coactivator‑1α (PGC‑1α) is a transcriptional coactivator that plays an important role in mitochondrial function by regulating mitochondrial biogenesis, energy metabolism and oxidative stress. The present review shows that PGC‑1α expression and activity in the heart are controlled by multiple signaling pathways, including adenosine monophosphate‑activated protein kinase, sirtuin 1/3 and nuclear factor κB. These can mediate the activation or inhibition of transcription and post‑translational modifications (such as phosphorylation and acetylation) of PGC‑1α. Furthermore, it highlighted the recent progress of PGC‑1α in HD, including heart failure, coronary heart disease, diabetic cardiomyopathy, drug‑induced cardiotoxicity and arrhythmia. Understanding the mechanisms underlying PGC‑1α in response to pathological stimulation may prove to be beneficial in developing new ideas and strategies for preventing and treating HDs. Meanwhile, the present review explored why the opposite results occurred when PGC‑1α was used as a target therapy.

Effects of Capsicum Oleoresin on the Energy Expenditure and Mitochondrial Content of Brown Adipose Tissue in Mice Fed a High-Fat Diet

Capsicum oleoresin (CO) is a concentrated extract derived from peppers (Capsicum annum L.) containing capsaicin (the active compound responsible for its pungency) and other bioactive components. The present study aimed to determine whether CO affects the energy expenditure and mitochondrial content of brown adipose tissue (BAT) in diet-induced obese mice. Four-week-old C57BL/6J mice were divided into three groups and fed with a normal chow diet, 45% high-fat diet (HF), or HF supplemented with 0.01% CO (HF+CO) for 16 weeks. The results showed that CO supplementation significantly suppressed weight gain and improved serum lipid profiles compared with HF feeding. The energy expenditure was significantly higher in the HF+CO group than in the HF group. Compared with the HF group, the HF+CO group had significantly upregulated the messenger RNA expression levels of uncoupling protein 1 (UCP1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) in BAT. The mitochondrial DNA content, which was reduced by HF intake, was significantly restored in the HF+CO group. Furthermore, the mitochondrial size and number were restored in the HF+CO group than in in the HF group. The activity of adenosine monophosphate-activated protein kinase (AMPK) in BAT was significantly increased in the HF+CO group than in the HF group. In conclusion, CO potentially inhibits weight gain by increasing energy expenditure in diet-induced obese mice. This beneficial effect is likely associated with the enhancement of mitochondrial content by upregulating key markers, including UCP1, PGC-1α, and AMPK, in BAT.

Mitochondrial pathways of copper neurotoxicity: focus on mitochondrial dynamics and mitophagy

Copper (Cu) is essential for brain development and function, yet its overload induces neuronal damage and contributes to neurodegeneration and other neurological disorders. Multiple studies demonstrated that Cu neurotoxicity is associated with mitochondrial dysfunction, routinely assessed by reduction of mitochondrial membrane potential. Nonetheless, the role of alterations of mitochondrial dynamics in brain mitochondrial dysfunction induced by Cu exposure is still debatable. Therefore, the objective of the present narrative review was to discuss the role of mitochondrial dysfunction in Cu-induced neurotoxicity with special emphasis on its influence on brain mitochondrial fusion and fission, as well as mitochondrial clearance by mitophagy. Existing data demonstrate that, in addition to mitochondrial electron transport chain inhibition, membrane damage, and mitochondrial reactive oxygen species (ROS) overproduction, Cu overexposure inhibits mitochondrial fusion by down-regulation of Opa1, Mfn1, and Mfn2 expression, while promoting mitochondrial fission through up-regulation of Drp1. It has been also demonstrated that Cu exposure induces PINK1/Parkin-dependent mitophagy in brain cells, that is considered a compensatory response to Cu-induced mitochondrial dysfunction. However, long-term high-dose Cu exposure impairs mitophagy, resulting in accumulation of dysfunctional mitochondria. Cu-induced inhibition of mitochondrial biogenesis due to down-regulation of PGC-1α further aggravates mitochondrial dysfunction in brain. Studies from non-brain cells corroborate these findings, also offering additional evidence that dysregulation of mitochondrial dynamics and mitophagy may be involved in Cu-induced damage in brain. Finally, Cu exposure induces cuproptosis in brain cells due mitochondrial proteotoxic stress, that may also contribute to neuronal damage and pathogenesis of certain brain diseases. Based on these findings, it is assumed that development of mitoprotective agents, specifically targeting mechanisms of mitochondrial quality control, would be useful for prevention of neurotoxic effects of Cu overload.

Metformin attenuates high-carbohydrate diet-induced redox imbalance, inflammation, and mitochondrial dysfunction in Megalobrama amblycephala

This study aimed to investigate the effects of dietary metformin supplementation on the redox balance, inflammation, mitochondrial biogenesis, and function in blunt snout bream fed a high-carbohydrate (HC) diet. Fish (45.12 ± 0.36 g) were randomly offered four diets, including a control diet (33% carbohydrate), an HC diet (45% carbohydrate), and the HC diet supplemented with 0.06% (HCM1) and 0.12% (HCM2) metformin respectively for 12 weeks. Compared with the control, feeding the HC diet significantly increased the hepatosomatic index (HSI), the mesenteric fat index, liver and muscle glycogen contents, liver and adipose tissue lipid contents, plasma glucose and glycation end products (AGES) levels and aspartate transaminase activity, plasma and liver malondialdehyde (MDA) contents, hepatic adenosine triphosphate (ATP) and adenosine monophosphate (AMP) contents, mitochondrial cytochrome c content, mitochondrial complex IV activity and ATP 6 transcription, but decreased plasma catalase (CAT) activity, muscle superoxide dismutase (SOD) activity, hepatic antioxidant enzymes activities, and the transcriptions of transforming growth factor β (tgfβ) and interleukin 10 (il10). Compared with the HC group, metformin treatment (especially the HCM2 group) significantly elevated tissue glycogen contents, muscle SOD activity, plasma and liver antioxidant enzymes activities, the transcriptions of tgfβ and il10, the sodium/potassium ATPase activity, the contents of mitochondrial protein and AMP, the level of p-AMP activated protein kinase (AMPK), and the p-AMPK/t-AMPK ratio, but lowered the HSI, tissue lipid contents, plasma levels of glucose, AGES and glycated serum protein, plasma, and liver MDA contents, the transcriptions of il1β, NADH dehydrogenase subunit 1 and ATP 6, the contents of ATP and cytochrome c, the ATP/AMP ratio, and the activities of complexes I and IV. In conclusion, metformin could attenuate the HC diet-induced redox imbalance, inflammation, and mitochondrial dysfunction in blunt snout bream.

Mitochondria-based holistic 3PM approach as the 'game-changer' for individualised rehabilitation-the proof-of-principle model by treated breast cancer survivors

Breast cancer belongs to the most commonly diagnosed malignancies worldwide, with its increasing incidence paralleled by advances in early diagnostics and effective treatments resulting in significantly improved survival rates. However, breast cancer survivors often experience significantly reduced quality of life linked to the long-term health burden as a consequence of aggressive oncological treatments applied. Their most frequently recorded complains include chronic fatigue, reduced physical activity, disordered sleep, chronification of pain, and severe mental health impairments-all per evidence are associated with compromised mitochondrial health and impaired homeostasis. Self-report of a breast cancer survivor is included in this article to illustrate currently uncovered patient needs. This article highlights mechanisms behind the suboptimal health of breast cancer survivors associated with mitochondrial damage, and introduces a novel, mitochondria-based holistic approach addressing rehabilitation concepts for breast cancer survivors following advanced principles of predictive, preventive and personalised medicine (3PM). By operating via mitochondrial function, the proposed holistic approach triggers systemic effects at molecular, sub/cellular and organismal levels positively affecting energy metabolism, repair mechanisms as well as physical and mental health creating, therefore, highly effective rehabilitation algorithms tailored to an individualised patient profile. The proposed methodology integrates mitochondrial health assessments utilising mitochondrial homeostasis biomarkers in tear fluid as a non-invasive diagnostic tool, tailored nutraceuticals and lifestyle adjustments. The introduced approach aligns with advanced principles of 3PM, offering a holistic and proactive framework for managing persistent post-treatment symptoms of suboptimal health in the cohort of cancer survivors. Furthermore, presented approach is also applicable to pre-habilitation programmes considering needs of other patient cohorts affected by chronic diseases such as CVD and orthopaedic disorders with planned major surgical incisions, who require individually adapted pre- and rehabilitation programmes. Implementing such innovative pre- and rehabilitation strategies may lead to a full recovery, sustainable health conditions and, therefore, facilitating patients' comeback to normal daily activities, family and professional life. Contextually, presented approach is considered a 'proof-of-principle' model for the 3PM-related paradigm shift from reactive medicine to a cost-effective holistic health management in both primary and secondary care benefiting a large spectrum of affected patient cohorts, individuals in suboptimal health conditions as well as society at large.

Nutritional Genomics: Implications for Age-Related Macular Degeneration

Background: Age-related macular degeneration (AMD) is a leading cause of vision loss in older individuals, driven by a multifactorial etiology involving genetic, environmental, and dietary factors. Nutritional genomics, which studies gene-nutrient interactions, has emerged as a promising field for AMD prevention and management. Genetic predispositions, such as variants in CFH, C3, C2/CFB, APOE, and oxidative stress pathways, significantly affect the risk and progression of AMD. Methods: This narrative review synthesizes findings from randomized controlled trials and recent advances in nutritional genomics research. It examines the interplay between genetic predispositions and dietary interventions, exploring how personalized nutritional strategies can optimize AMD management. Results and Discussion: The AREDS and AREDS2 trials demonstrated that supplements, including vitamins C, E, zinc, copper, lutein, and zeaxanthin, can reduce the progression to advanced AMD. Nutritional interventions tailored to genetic profiles show promise: CFH risk alleles may enhance zinc supplementation's anti-inflammatory effects, while APOE variants influence the response to omega-3 fatty acids. Adjusting carotenoid intake, such as lutein and zeaxanthin, based on genetic susceptibility exemplifies emerging precision nutritional approaches. Ongoing research seeks to integrate nutrigenomic testing into clinical settings, enabling clinicians to tailor interventions to individual genetic profiles. Conclusions: Further studies are needed to assess the long-term effects of personalized interventions, investigate additional genetic variants, and develop tools for clinical implementation of nutrigenomics. Advancing these strategies holds the potential to improve patient outcomes, optimize AMD management, and pave the way for precision nutrition in ophthalmology.

Neuroprotective Role of Transchalcone in Parkinson's Disease through AMP-activated Protein Kinase-mediated Signaling Pathway

ABSTRACT

Parkinson's disease (PD) is a gradually worsening neurodegenerative condition marked by the deterioration of dopaminergic neurons, motor dysfunction, and mitochondrial dysfunction. Trans-chalcone, a natural flavonoid, has shown promise in various disease models because of its antioxidant and anti-inflammatory features. This study investigates the neuroprotective effects of transchalcone in a rat model of PD, focusing on its impact on the activation levels of AMP-activated protein kinase (AMPK) signaling pathway, sirtuin1 (SIRT1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) proteins, and mitochondrial-inflammatory responses. Male Sprague Dawley rats were allocated into five groups Control, Control plus transchalcone, PD, PD plus transchalcone, PD plus compound-C, and PD plus Compound-C and trans-chalcone. PD was induced using intranigral 6-hydroxydopamine injection. Trans-chalcone (100 μg/kg) and compound-C (20 mg/kg) were intraperitoneally administered daily for 4 weeks in PD rats. Motor function was assessed using rota-rod and grid tests. Striatal dopamine and cytokines (interleukin 1-beta [IL-1 β], IL-10) and p65-nuclear factor kappa-B (NF-κB) levels were measured with enzyme-linked immunosorbent assay. Mitochondrial function was evaluated by fluorometric techniques. The expression of phosphorylated AMPK, PGC-1α, and SIRT1 was analyzed by Western blotting. Trans-chalcone treatment significantly improved motor function, evidenced by increased latency to fall in the rota-rod test and recovered traversal time in the grid test. It also restored dopamine levels, enhanced mitochondrial function (reduced reactive oxygen species levels, increased membrane potential, and adenosine triphosphate production), normalized cytokines (IL-1 β, IL-10) and p65-NF-κB, and upregulated the proteins expression in rats with PD. Inhibition of AMPK activity with compound-C suppressed the neuroprotective impacts of trans-chalcone, highlighting the contribution of AMPK signaling pathway in its mechanism of action. Neuroprotective and mitoprotective impacts of trans-chalcone were mostly mediated through the activation of AMPK-SIRT1-PGC1α pathway. These results indicate that trans-chalcone could be a promising therapeutic agent for PD, warranting further investigation to assess its efficacy and safety in human patients.

Acetylcholine receptor-β inhibition by interleukin-6 in skeletal muscles contributes to modulating neuromuscular junction during aging

BACKGROUND

Aging-related strength decline contributes to physiological deterioration and is a good predictor of poor prognosis. However, the mechanisms underlying neuromuscular junction disorders affecting contraction in aging are not well described. We hypothesized that the autocrine effect of interleukin (IL)-6 secreted by skeletal muscle inhibits acetylcholine receptor (AChR) expression, potentially causing aging-related strength decline. Therefore, we investigated IL-6 and AChR β-subunit (AChR-β) expression in the muscles and sera of aging C57BL/6J mice and verified the effect of IL-6 on AChR-β expression.

METHODS

Animal experiments, in vitro studies, bioinformatics, gene manipulation, dual luciferase reporter gene assays, and chromatin immunoprecipitation experiments were used to explore the role of the transcription cofactor peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC1α) and its interacting transcription factors in the IL-6-mediated regulation of AChR-β expression.

RESULTS

IL-6 expression gradually increased during aging, inhibiting AChR-β expression, which was reversed by tocilizumab. Both tocilizumab and the PGC1α agonist reversed the inhibiting effect of IL-6 expression on AChR-β. Compared to inhibition of signal transducer and activator of transcription 3, extracellular signal-regulated kinases 1/2 (ERK1/2) inhibition suppressed the effects of IL-6 on AChR-β and PGC1α. In aging mouse muscles and myotubes, myocyte enhancer factor 2 C (MEF2C) was recruited by PGC1α, which directly binds to the AChR-β promoter to regulate its expression.

CONCLUSIONS

This study verifies AChR-β regulation by the IL-6/IL-6R-ERK1/2-PGC1α/MEF2C pathway. Hence, evaluating muscle secretion, myokines, and AChRs at an earlier stage to determine pathological progression is important. Moreover, developing intervention strategies for monitoring, maintaining, and improving muscle structure and function is necessary.

Cells and Molecules Underpinning Cannabis-Related Variations in Cortical Thickness during Adolescence

During adolescence, cannabis experimentation is common, and its association with interindividual variations in brain maturation well studied. Cellular and molecular underpinnings of these system-level relationships are, however, unclear. We thus conducted a three-step study. First, we exposed adolescent male mice to Δ-9-tetrahydrocannabinol (THC) or a synthetic cannabinoid WIN 55,212-2 (WIN) and assessed differentially expressed genes (DEGs), spine numbers, and dendritic complexity in their frontal cortex. Second, in human (male) adolescents, we examined group differences in cortical thickness in 34 brain regions, using magnetic resonance imaging, between those who experimented with cannabis before age 16 (n = 140) and those who did not (n = 327). Finally, we correlated spatially these group differences with gene expression of human homologs of mouse-identified DEGs. The spatial expression of 13 THC-related human homologs of DEGs correlated with cannabis-related variations in cortical thickness, and virtual histology revealed coexpression patterns of these 13 genes with cell-specific markers of astrocytes, microglia, and a type of pyramidal cells enriched in dendrite-regulating genes. Similarly, the spatial expression of 18 WIN-related human homologs of DEGs correlated with group differences in cortical thickness and showed coexpression patterns with the same three cell types. Gene ontology analysis indicated that 37 THC-related human homologs are enriched in neuron projection development, while 33 WIN-related homologs are enriched in processes associated with learning and memory. In mice, we observed spine loss and lower dendritic complexity in pyramidal cells of THC-exposed animals (vs controls). Experimentation with cannabis during adolescence may influence cortical thickness by impacting glutamatergic synapses and dendritic arborization.

The Changes of Mitochondria during Aging and Regeneration

Aging and regeneration are opposite cellular processes. Aging refers to progressive dysfunction in most cells and tissues, and regeneration refers to the replacement of damaged or dysfunctional cells or tissues with existing adult or somatic stem cells. Various studies have shown that aging is accompanied by decreased regenerative abilities, indicating a link between them. The performance of any cellular process needs to be supported by the energy that is majorly produced by mitochondria. Thus, mitochondria may be a link between aging and regeneration. It should be interesting to discuss how mitochondria behave during aging and regeneration. The changes of mitochondria in aging and regeneration discussed in this review can provide a timely and necessary study of the causal roles of mitochondrial homeostasis in longevity and health.

Potential Role of Dipeptidyl Peptidase-4 in Regulating Mitochondria and Oxidative Stress in Cardiomyocytes

Oxidative stress causes mitochondrial damage and bioenergetic dysfunction and inhibits adenosine triphosphate production, contributing to the pathogenesis of cardiac diseases. Dipeptidyl peptidase 4 (DPP4) is primarily a membrane-bound extracellular peptidase that cleaves Xaa-Pro or Xaa-Ala dipeptides from the N terminus of polypeptides. DPP4 inhibitors have been used in patients with diabetes and heart failure; however, they have led to inconsistent results. Although the enzymatic properties of DPP4 have been well studied, the substrate-independent functions of DPP4 have not. In the present study, we knocked down DPP4 in cultured cardiomyocytes to exclude the effects of differential alteration in the substrates and metabolites of DPP4 then compared the response between the knocked-down and wild-type cardiomyocytes during exposure to oxidative stress. H2O2 exposure induced DPP4 expression in both types of cardiomyocytes. However, knocking down DPP4 substantially reduced the loss of cell viability by preserving mitochondrial bioenergy, reducing intracellular reactive oxygen species production, and reducing apoptosis-associated protein expression. These findings demonstrate that inhibiting DPP4 improves the body's defense against oxidative stress by enhancing Nrf2 and PGC-1α signaling and increasing superoxide dismutase and catalase activity. Our results indicate that DPP4 mediates the body's response to oxidative stress in individuals with heart disease.

α-Arbutin ameliorates UVA-induced photoaging through regulation of the SIRT3/PGC-1α pathway

Owing to its tyrosinase inhibitory activity, α-arbutin has been added to several skin care products as a skin-lightening agent. However, the protective effect of α-arbutin against ultraviolet A (UVA)-induced photoaging has not been well investigated. The present study was designed to investigate the photoprotective effect and mechanism of α-arbutin against UVA-induced photoaging. In vitro experiments, HaCaT cells were treated with UVA at a dose of 3 J/cm2 to evaluate the anti-photoaging effect of α-arbutin. α-Arbutin was found to exhibit a strong antioxidant effect by increasing glutathione (GSH) level and inhibiting reactive oxygen species (ROS) production. Meanwhile, α-arbutin markedly improved the expression of sirtuin 3 (SIRT3) and peroxisome proliferator-activated receptor γ coactivator 1 α (PGC-1α) proteins, initiating downstream signaling to increase mitochondrial membrane potential and mediate mitochondrial biogenesis, and improve mitochondrial structure significantly. In vivo analysis, the mice with shaved back hair were irradiated with a cumulative UVA dose of 10 J/cm2 and a cumulative ultraviolet B (UVB) dose of 0.63 J/cm2. The animal experiments demonstrated that α-arbutin increased the expression of SIRT3 and PGC-1α proteins in the back skin of mice, thereby reducing UV-induced skin damage. In conclusion, α-arbutin protects HaCaT cells and mice from UVA damage by regulating SIRT3/PGC-1α signaling pathway.

Omega-3 Fatty Acids Modify Drp1 Expression and Activate the PINK1-Dependent Mitophagy Pathway in the Kidney and Heart of Adenine-Induced Uremic Rats

Mitochondrial homeostasis is controlled by biogenesis, dynamics, and mitophagy. Mitochondrial dysfunction plays a central role in cardiovascular and renal disease and omega-3 fatty acids (FAs) are beneficial for cardiovascular disease. We investigated whether omega-3 fatty acids (FAs) regulate mitochondrial biogenesis, dynamics, and mitophagy in the kidney and heart of adenine-induced uremic rats. Eighteen male Sprague Dawley rats were divided into normal control, adenine control, and adenine with omega-3 FA groups. Using Western blot analysis, the kidney and heart expression of mitochondrial homeostasis-related molecules, including peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α), dynamin-related protein 1 (Drp1), and phosphatase and tensin homolog-induced putative kinase 1 (PINK1) were investigated. Compared to normal, serum creatinine and heart weight/body weight in adenine control were increased and slightly improved in the omega-3 FA group. Compared to the normal controls, the expression of PGC-1α and PINK1 in the kidney and heart of the adenine group was downregulated, which was reversed after omega-3 FA supplementation. Drp1 was upregulated in the kidney but downregulated in the heart in the adenine group. Drp1 expression in the heart recovered in the omega-3 FA group. Mitochondrial DNA (mtDNA) was decreased in the kidney and heart of the adenine control group but the mtDNA of the heart was recovered in the omega-3 FA group. Drp1, which is related to mitochondrial fission, may function oppositely in the uremic kidney and heart. Omega-3 FAs may be beneficial for mitochondrial homeostasis by activating mitochondrial biogenesis and PINK1-dependent mitophagy in the kidney and heart of uremic rats.

Research Hotspots in Mitochondria-Related Studies for AKI Treatment: A Bibliometric Study

Purpose

Acute kidney injury (AKI) is a common clinical critical condition that has become a significant healthcare burden. In recent years, the relationship between AKI and mitochondria has attracted increasing attention. Protecting mitochondria or restoring their function has emerged as a novel therapeutic strategy for alleviating AKI. This study aims to analyze and summarize the current status, research trends, and hotspots in this field, providing references and directions for future research.

Methods

AKI and mitochondria-related literature from the Web of Science core collection were retrieved and collected. Bibliometric and visualization analyses were conducted using Microsoft Excel 2021, bibliometric tools (VosViewer, Citespace 6.3.R1, and the bibliometrix R package), R 4.3.2, and SCImagoGraphica software.

Results

A total of 2433 publications were included in this study. The number of annual publications in this field has increased year by year. China and the United States are the two most productive countries. Central South University is the most influential research institution in terms of research output, and Parikh SM, Schnellmann RG, and Dong Z are the most influential authors in this field. KIDNEY INTERNATIONAL, JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY, and AMERICAN JOURNAL OF PHYSIOLOGY-RENAL PHYSIOLOGY are the most influential journals. Initially, the research focused on keywords such as oxidative stress, ischemia-reperfusion injury, apoptosis, inflammation, and autophagy. In recent years, new research hotspots have emerged, including ferroptosis, aging, mitochondrial quality control, messenger RNA, mitochondrial-targeted antioxidants, extracellular vesicles, and nanodrug delivery.

Conclusion

Research on the relationship between mitochondria and AKI has broad developing prospects, and targeting mitochondrial regulation will become a focus of future AKI prevention and treatment research.

SMYD2 induced PGC1α methylation promotes stemness maintenance of glioblastoma stem cells

BACKGROUND

The high fatality rate of glioblastoma (GBM) is attributed to glioblastoma stem cells (GSCs), which exhibit heterogeneity and therapeutic resistance. Metabolic plasticity of mitochondria is the hallmark of GSCs. Targeting mitochondrial biogenesis of GSCs is crucial for improving clinical prognosis in GBM patients.

METHODS

SMYD2-induced PGC1α methylation and followed nuclear export are confirmed by co-immunoprecipitation, cellular fractionation, and immunofluorescence. The effects of SMYD2/PGC1α/CRM1 axis on GSCs mitochondrial biogenesis are validated by oxygen consumption rate, ECAR, and intracranial glioma model.

RESULTS

PGC1α methylation causes the disabled mitochondrial function to maintain the stemness, thereby enhancing the radio-resistance of GSCs. SMYD2 drives PGC1α K224 methylation (K224me), which is essential for promoting the stem-like characteristics of GSCs. PGC1α K224me is preferred binding with CRM1, accelerating PGC1α nuclear export and subsequent dysfunction. Targeting PGC1α methylation exhibits significant radiotherapeutic efficacy and prolongs patient survival.

CONCLUSIONS

These findings unveil a novel regulatory pathway involving mitochondria that govern stemness in GSCs, thereby emphasizing promising therapeutic strategies targeting PGC1α and mitochondria for the treatment of GBM.

lncRNA Gm20257 alleviates pathological cardiac hypertrophy by modulating the PGC-1α-mitochondrial complex IV axis

Pathological cardiac hypertrophy, a major contributor to heart failure, is closely linked to mitochondrial function. The roles of long noncoding RNAs (lncRNAs), which regulate mitochondrial function, remain largely unexplored in this context. Herein, a previously unknown lncRNA, Gm20257, was identified. It markedly increased under hypertrophic stress in vivo and in vitro. The suppression of Gm20257 by using small interfering RNAs significantly induced cardiomyocyte hypertrophy. Conversely, the overexpression of Gm20257 through plasmid transfection or adeno-associated viral vector-9 mitigated angiotensin II-induced hypertrophic phenotypes in neonatal mouse ventricular cells or alleviated cardiac hypertrophy in a mouse TAC model respectively, thus restoring cardiac function. Importantly, Gm20257 restored mitochondrial complex IV level and enhanced mitochondrial function. Bioinformatics prediction showed that Gm20257 had a high binding score with peroxisome proliferator-activated receptor coactivator-1 (PGC-1α), which could increase mitochondrial complex IV. Subsequently, Western blot analysis results revealed that Gm20257 substantially affected the expression of PGC-1α. Further analyses through RNA immunoprecipitation and immunoblotting following RNA pull-down indicated that PGC-1α was a direct downstream target of Gm20257. This interaction was demonstrated to rescue the reduction of mitochondrial complex IV induced by hypertrophic stress and promote the generation of mitochondrial ATP. These findings suggest that Gm20257 improves mitochondrial function through the PGC-1α-mitochondrial complex IV axis, offering a novel approach for attenuating pathological cardiac hypertrophy.

Mitochondrial Adaptations in Aging Skeletal Muscle: Implications for Resistance Exercise Training to Treat Sarcopenia

Sarcopenia, the age-related decline in muscle mass and function, poses a significant health challenge as the global population ages. Mitochondrial dysfunction is a key factor in sarcopenia, as evidenced by the role of mitochondrial reactive oxygen species (mtROS) in mitochondrial biogenesis and dynamics, as well as mitophagy. Resistance exercise training (RET) is a well-established intervention for sarcopenia; however, its effects on the mitochondria in aging skeletal muscles remain unclear. This review aims to elucidate the relationship between mitochondrial dynamics and sarcopenia, with a specific focus on the implications of RET. Although aerobic exercise training (AET) has traditionally been viewed as more effective for mitochondrial enhancement, emerging evidence suggests that RET may also confer beneficial effects. Here, we highlight the potential of RET to modulate mtROS, drive mitochondrial biogenesis, optimize mitochondrial dynamics, and promote mitophagy in aging skeletal muscles. Understanding this interplay offers insights for combating sarcopenia and preserving skeletal muscle health in aging individuals.

Endoplasmic reticulum stress signaling modulates ischemia/reperfusion injury in the aged heart by regulating mitochondrial maintenance

Aging is associated with an increased risk of myocardial ischemia/reperfusion injury (IRI). With an increasing prevalence of cardiovascular diseases such as coronary arteriosclerosis in older people, there has been increasing interest in understanding the mechanisms of myocardial IRI to develop therapeutics that can attenuate its damaging effects. Previous studies identified that abnormal mitochondria, involved in cellar senescence and oxidative stress, are the master subcellular organelle that induces IRI. In addition, endoplasmic reticulum (ER) stress is also associated with IRI. Cellular adaptation to ER stress is achieved by the activation of ER molecular chaperones and folding enzymes, which provide an important link between ER stress and oxidative stress gene programs. In this review, we outline how these ER stress-related molecules affect myocardial IRI via the crosstalk of ER stress and mitochondrial homeostasis and discuss how these may offer promising novel therapeutic targets and strategies against age-related cardiovascular diseases.

Activation of GPER1 by G1 prevents PTSD-like behaviors in mice: Illustrating the mechanisms from BDNF/TrkB to mitochondria and synaptic connection

BACKGROUND

G1 is a specific agonist of G protein-coupled estrogen receptor 1 (GPER1), which binds and activates GPER1 to exert various neurological functions. However, the preventive effect of G1 on post-traumatic stress disorder (PTSD) and its mechanisms are unclear.

OBJECTIVE

To evaluate the protective effect of G1 against synaptic and mitochondrial impairments and to investigate the mechanism of G1 to improve PTSD from brain-derived neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB) signaling.

METHODS

This study initially detected GPER1 expression in the hippocampus of single prolonged stress (SPS) mice, utilizing both Western blot and immunofluorescence staining. Subsequently, the effects of G1 on PTSD-like behaviors, synaptic, and mitochondrial functions in SPS mice were investigated. Additionally, the involvement of BDNF/TrkB signaling involved in the protection was further confirmed using GPER1 antagonist and TrkB inhibitor, respectively.

RESULTS

The expression of GPER1 was reduced in the hippocampus of SPS mice, and G1 treatment given for 14 consecutive days significantly improved PTSD-like behaviors in SPS mice compared with model group. Electrophysiological local field potential (LFP) results showed that G1 administration for 14 consecutive days could reverse the abnormal changes in the gamma oscillation in the CA1 region of SPS mice. Meanwhile, G1 administration for 14 consecutive days could significantly improve the abnormal expression of synaptic proteins, increase the expression of mitochondria-related proteins, increase the number of synapses in the hippocampus, and ameliorate the damage of hippocampal mitochondrial structure in SPS mice. In addition, G15 (GPER1 inhibitor) and ANA-12 (TrkB inhibitor) blocked the ameliorative effects of G1 on PTSD-like behaviors and aberrant expression of hippocampal synaptic and mitochondrial proteins in SPS mice and inhibited the reparative effects of G1 on structural damage to hippocampal mitochondria, respectively.

CONCLUSION

G1 improved PTSD-like behaviors in SPS mice, possibly by increasing hippocampal GPER1 expression and promoting BDNF/TrkB signaling to repair synaptic and mitochondrial functional impairments. This study would provide critical mechanism for the prevention and treatment of PTSD.

KLF13 Attenuates Lipopolysaccharide-Induced Alveolar Epithelial Cell Damage by Regulating Mitochondrial Quality Control via Binding PGC-1α

Sepsis is a clinically life-threatening syndrome, and acute lung injury is the earliest and most serious complication. We aimed to assess the role of kruppel-like factor 13 (KLF13) in lipopolysaccharide (LPS)-induced human alveolar type II epithelial cell damage and to reveal the possible mechanism related to peroxisome proliferator-activated receptor-γ co-activator 1-α (PGC-1α). In LPS-treated A549 cells with or without KLF13 overexpression or PGC-1α knockdown, cell viability was measured by a cell counting kit-8 assay. Enzyme-linked immunosorbent assay kits detected the levels of inflammatory factors, and terminal deoxynucleotidyl transferase dUTP nick-end labeling staining measured cell apoptosis. Besides, mitochondrial reactive oxygen species (MitoSOX) and mitochondrial membrane potential were detected using MitoSOX red- and JC-1 staining. Expression of proteins related to mitochondrial quality control (MQC) was evaluated by western blot. Co-immunoprecipitation (Co-IP) assay was used to analyze the interaction between KLF13 and PGC-1α. Results indicated that KLF13 was highly expressed in LPS-treated A549 cells. KLF13 upregulation elevated the viability and reduced the levels of inflammatory factors in A549 cells exposed to LPS. Moreover, KLF13 gain-of-function inhibited LPS-induced apoptosis of A549 cells, accompanied by upregulated BCL2 expression and downregulated Bax and cleaved caspase3 expression. Furthermore, MQC was improved by KLF13 overexpression, as evidenced by decreased MitoSOX, JC-1 monomers and increased JC-1 aggregates, coupled with the changes of proteins related to MQC. In addition, Co-IP assay confirmed the interaction between KLF13 and PGC-1α. PGC-1α deficiency restored the impacts of KLF13 upregulation on the inflammation, apoptosis, and MQC in LPS-treated A549 cells. In conclusion, KLF13 attenuated LPS-induced alveolar epithelial cell inflammation and apoptosis by regulating MQC via binding PGC-1α.

CREB3 mediates the transcriptional regulation of PGC-1α, a master regulator of energy homeostasis and mitochondrial biogenesis

Lipid metabolism hinges on a balance between lipogenesis and fatty acid oxidation (FAO). Disruptions in this balance can induce endoplasmic reticulum (ER) stress triggering the unfolded protein response (UPR) and contribute to metabolic diseases. The UPR protein, Luman or CREB3, has recently been implicated in metabolic regulation-CREB3 knockout mice exhibit resistance to diet-induced obesity and altered insulin sensitivity. Here, we show that CREB3 activated PPARGC1A transcription from a 1 kb promoter region. An increase in CREB3 expression correlated inversely with endogenous PPARGC1A mRNA levels and genes involved in FAO. As PGC-1α encoded by PPARGC1A is a master regulator of mitochondrial biogenesis and energy homeostasis, these findings demonstrate that CREB3 is a transcriptional regulator of PGC-1α, underlining the potential role of CREB3 in energy metabolism.

Exogenous Nucleotides Improve the Skin Aging of SAMP8 Mice by Modulating Autophagy through MAPKs and AMPK Pathways

The skin, serving as the body's primary defense against external elements, plays a crucial role in protecting the body from infections and injuries, as well as maintaining overall homeostasis. Skin aging, a common manifestation of the aging process, involves the gradual deterioration of its normal structure and repair mechanisms. Addressing the issue of skin aging is increasingly imperative. Multiple pieces of evidence indicate the potential anti-aging effects of exogenous nucleotides (NTs) through their ability to inhibit oxidative stress and inflammation. This study aims to investigate whether exogenous NTs can slow down skin aging and elucidate the underlying mechanisms. To achieve this objective, senescence-accelerated mouse prone-8 (SAMP8) mice were utilized and randomly allocated into Aging, NTs-low, NTs-middle, and NTs-high groups, while senescence-accelerated mouse resistant 1 (SAMR1) mice were employed as the control group. After 9 months of NT intervention, dorsal skin samples were collected to analyze the pathology and assess the presence and expression of substances related to the aging process. The findings indicated that a high-dose NT treatment led to a significant increase in the thickness of the epithelium and dermal layers, as well as Hyp content (p < 0.05). Additionally, it was observed that low-dose NT intervention resulted in improved aging, as evidenced by a significant decrease in p16 expression (p < 0.05). Importantly, the administration of high doses of NTs could improve, in some ways, mitochondrial function, which is known to reduce oxidative stress and promote ATP and NAD+ production significantly. These observed effects may be linked to NT-induced autophagy, as evidenced by the decreased expression of p62 and increased expression of LC3BI/II in the intervention groups. Furthermore, NTs were found to upregulate pAMPK and PGC-1α expression while inhibiting the phosphorylation of p38MAPK, JNK, and ERK, suggesting that autophagy may be regulated through the AMPK and MAPK pathways. Therefore, the potential induction of autophagy by NTs may offer benefits in addressing skin aging through the activation of the AMPK pathway and the inhibition of the MAPK pathway.

Emerging Multi-omic Approaches to the Molecular Diagnosis of Mitochondrial Disease and Available Strategies for Treatment and Prevention

Mitochondria are semi-autonomous organelles present in several copies within most cells in the human body that are controlled by the precise collaboration of mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) encoding mitochondrial proteins. They play important roles in numerous metabolic pathways, such as the synthesis of adenosine triphosphate (ATP), the predominant energy substrate of the cell generated through oxidative phosphorylation (OXPHOS), intracellular calcium homeostasis, metabolite biosynthesis, aging, cell cycles, and so forth. Previous studies revealed that dysfunction of these multi-functional organelles, which may arise due to mutations in either the nuclear or mitochondrial genome, leads to a diverse group of clinically and genetically heterogeneous disorders. These diseases include neurodegenerative and metabolic disorders as well as cardiac and skeletal myopathies in both adults and newborns. The plethora of phenotypes and defects displayed leads to challenges in the diagnosis and treatment of mitochondrial diseases. In this regard, the related literature proposed several diagnostic options, such as high throughput mitochondrial genomics and omics technologies, as well as numerous therapeutic options, such as pharmacological approaches, manipulating the mitochondrial genome, increasing the mitochondria content of the affected cells, and recently mitochondrial diseases transmission prevention. Therefore, the present article attempted to review the latest advances and challenges in diagnostic and therapeutic options for mitochondrial diseases.

Decreasing Intracellular Entropy by Increasing Mitochondrial Efficiency and Reducing ROS Formation-The Effect on the Ageing Process and Age-Related Damage

A hypothesis is presented to explain how the ageing process might be influenced by optimizing mitochondrial efficiency to reduce intracellular entropy. Research-based quantifications of entropy are scarce. Non-equilibrium metabolic reactions and compartmentalization were found to contribute most to lowering entropy in the cells. Like the cells, mitochondria are thermodynamically open systems exchanging matter and energy with their surroundings-the rest of the cell. Based on the calculations from cancer cells, glycolysis was reported to produce less entropy than mitochondrial oxidative phosphorylation. However, these estimations depended on the CO2 concentration so that at slightly increased CO2, it was oxidative phosphorylation that produced less entropy. Also, the thermodynamic efficiency of mitochondrial respiratory complexes varies depending on the respiratory state and oxidant/antioxidant balance. Therefore, in spite of long-standing theoretical and practical efforts, more measurements, also in isolated mitochondria, with intact and suboptimal respiration, are needed to resolve the issue. Entropy increases in ageing while mitochondrial efficiency of energy conversion, quality control, and turnover mechanisms deteriorate. Optimally functioning mitochondria are necessary to meet energy demands for cellular defence and repair processes to attenuate ageing. The intuitive approach of simply supplying more metabolic fuels (more nutrients) often has the opposite effect, namely a decrease in energy production in the case of nutrient overload. Excessive nutrient intake and obesity accelerate ageing, while calorie restriction without malnutrition can prolong life. Balanced nutrient intake adapted to needs/activity-based high ATP requirement increases mitochondrial respiratory efficiency and leads to multiple alterations in gene expression and metabolic adaptations. Therefore, rather than overfeeding, it is necessary to fine-tune energy production by optimizing mitochondrial function and reducing oxidative stress; the evidence is discussed in this paper.

PGC-1α repression dysregulates lipid metabolism and induces lipid droplet accumulation in retinal pigment epithelium

Drusen, the yellow deposits under the retina, are composed of lipids and proteins, and represent a hallmark of age-related macular degeneration (AMD). Lipid droplets are also reported in the retinal pigment epithelium (RPE) from AMD donor eyes. However, the mechanisms underlying these disease phenotypes remain elusive. Previously, we showed that Pgc-1α repression, combined with a high-fat diet (HFD), induce drastic AMD-like phenotypes in mice. We also reported increased PGC-1α acetylation and subsequent deactivation in the RPE derived from AMD donor eyes. Here, through a series of in vivo and in vitro experiments, we sought to investigate the molecular mechanisms by which PGC-1α repression could influence RPE and retinal function. We show that PGC-1α plays an important role in RPE and retinal lipid metabolism and function. In mice, repression of Pgc-1α alone induced RPE and retinal degeneration and drusen-like deposits. In vitro inhibition of PGC1A by CRISPR-Cas9 gene editing in human RPE (ARPE19- PGC1A KO) affected the expression of genes responsible for lipid metabolism, fatty acid β-oxidation (FAO), fatty acid transport, low-density lipoprotein (LDL) uptake, cholesterol esterification, cholesterol biosynthesis, and cholesterol efflux. Moreover, inhibition of PGC1A in RPE cells caused lipid droplet accumulation and lipid peroxidation. ARPE19-PGC1A KO cells also showed reduced mitochondrial biosynthesis, impaired mitochondrial dynamics and activity, reduced antioxidant enzymes, decreased mitochondrial membrane potential, loss of cardiolipin, and increased susceptibility to oxidative stress. Our data demonstrate the crucial role of PGC-1α in regulating lipid metabolism. They provide new insights into the mechanisms involved in lipid and drusen accumulation in the RPE and retina during aging and AMD, which may pave the way for developing novel therapeutic strategies targeting PGC-1α.

Senegenin Attenuates Pulmonary Fibrosis by Inhibiting Oxidative-Stress-Induced Epithelial Cell Senescence through Activation of the Sirt1/Pgc-1α Signaling Pathway

Idiopathic pulmonary fibrosis is a fatal interstitial lung disease for which effective drug therapies are lacking. Senegenin, an effective active compound from the traditional Chinese herb Polygala tenuifolia Willd, has been shown to have a wide range of pharmacological effects. In this study, we investigated the therapeutic effects of senegenin on pulmonary fibrosis and their associated mechanisms of action. We found that senegenin inhibited the senescence of epithelial cells and thus exerted anti-pulmonary-fibrosis effects by inhibiting oxidative stress. In addition, we found that senegenin promoted the expression of Sirt1 and Pgc-1α and that the antioxidative and antisenescent effects of senegenin were suppressed by specific silencing of the Sirt1 and Pgc-1α genes, respectively. Moreover, the senegenin-induced effects of antioxidation, antisenescence of epithelial cells, and antifibrosis were inhibited by treatment with Sirt1 inhibitors in vivo. Thus, the Sirt1/Pgc-1α pathway exerts its antifibrotic effect on lung fibrosis by mediating the antioxidative and antisenescent effects of senegenin.

Bile acid metabolism and signaling in health and disease: molecular mechanisms and therapeutic targets

Bile acids, once considered mere dietary surfactants, now emerge as critical modulators of macronutrient (lipid, carbohydrate, protein) metabolism and the systemic pro-inflammatory/anti-inflammatory balance. Bile acid metabolism and signaling pathways play a crucial role in protecting against, or if aberrant, inducing cardiometabolic, inflammatory, and neoplastic conditions, strongly influencing health and disease. No curative treatment exists for any bile acid influenced disease, while the most promising and well-developed bile acid therapeutic was recently rejected by the FDA. Here, we provide a bottom-up approach on bile acids, mechanistically explaining their biochemistry, physiology, and pharmacology at canonical and non-canonical receptors. Using this mechanistic model of bile acids, we explain how abnormal bile acid physiology drives disease pathogenesis, emphasizing how ceramide synthesis may serve as a unifying pathogenic feature for cardiometabolic diseases. We provide an in-depth summary on pre-existing bile acid receptor modulators, explain their shortcomings, and propose solutions for how they may be remedied. Lastly, we rationalize novel targets for further translational drug discovery and provide future perspectives. Rather than dismissing bile acid therapeutics due to recent setbacks, we believe that there is immense clinical potential and a high likelihood for the future success of bile acid therapeutics.

Upregulation of PGC-1α expression by pioglitazone mediates prevention of sepsis-induced acute lung injury

The imbalance between pro-inflammatory M1 and anti-inflammatory M2 macrophages plays a critical role in the pathogenesis of sepsis-induced acute lung injury (ALI). Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) may modulate macrophage polarization toward the M2 phenotype by altering mitochondrial activity. This study aimed to investigate the role of the PGC-1α agonist pioglitazone (PGZ) in modulating sepsis-induced ALI. A mouse model of sepsis-induced ALI was established using cecal ligation and puncture (CLP). An in vitro model was created by stimulating MH-S cells with lipopolysaccharide (LPS). qRT-PCR was used to measure mRNA levels of M1 markers iNOS and MHC-II and M2 markers Arg1 and CD206 to evaluate macrophage polarization. Western blotting detected expression of peroxisome proliferator-activated receptor gamma (PPARγ) PGC-1α, and mitochondrial biogenesis proteins NRF1, NRF2, and mtTFA. To assess mitochondrial content and function, reactive oxygen species levels were detected by dihydroethidium staining, and mitochondrial DNA copy number was measured by qRT-PCR. In the CLP-induced ALI mouse model, lung tissues exhibited reduced PGC-1α expression. PGZ treatment rescued PGC-1α expression and alleviated lung injury, as evidenced by decreased lung wet-to-dry weight ratio, pro-inflammatory cytokine secretion (tumor necrosis factor-α, interleukin-1β, interleukin-6), and enhanced M2 macrophage polarization. Mechanistic investigations revealed that PGZ activated the PPARγ/PGC-1α/mitochondrial protection pathway to prevent sepsis-induced ALI by inhibiting M1 macrophage polarization. These results may provide new insights and evidence for developing PGZ as a potential ALI therapy.

Emodin alleviates CRS4-induced mitochondrial damage via activation of the PGC1α signaling

Cardiorenal syndrome type 4 (CRS4), a progressive deterioration of cardiac function secondary to chronic kidney disease (CKD), is a leading cause of death in patients with CKD. In this study, we aimed to investigate the cardioprotective effect of emodin on CRS4. C57BL/6 mice with 5/6 nephrectomy and HL-1 cells stimulated with 5% CKD mouse serum were used for in vivo and in vitro experiments. To assess the cardioprotective potential of emodin, we employed a comprehensive array of methodologies, including echocardiography, tissue staining, immunofluorescence staining, biochemical detection, flow cytometry, real-time quantitative PCR, and western blot analysis. Our results showed that emodin exerted protective effects on the function and structure of the residual kidney. Emodin also reduced pathologic changes in the cardiac morphology and function of these mice. These effects may have been related to emodin-mediated suppression of reactive oxygen species production, reduction of mitochondrial oxidative damage, and increase of oxidative metabolism via restoration of PGC1α expression and that of its target genes. In contrast, inhibition of PGC1α expression significantly reversed emodin-mediated cardioprotection in vivo. In conclusion, emodin protects the heart from 5/6 nephrectomy-induced mitochondrial damage via activation of the PGC1α signaling. The findings obtained in our study can be used to develop effective therapeutic strategies for patients with CRS4.

Mitophagy regulates mitochondrial number following pharmacological induction of mitochondrial biogenesis in renal proximal tubule cells

Background: Mitochondrial biogenesis (MB) induction through the activation of the 5-Hydroxytriptamine (5-HT) 1F receptor (HTR1F) is a promising mechanism for the treatment of diseases characterized by mitochondrial dysfunction, such as acute kidney injury (AKI). While several studies report pharmacological activation of MB in the proximal tubule, it is unclear how the proximal tubule regulates itself once the pharmacological activation is removed. Mitophagy is the process of selective mitochondria degradation. We hypothesize that mitophagy decreases mitochondrial number after pharmacological stimulation and restore mitochondrial homeostasis. Methods: Renal proximal tubules were treated at time 0hr with LY344864 or vehicle for 24 h and then removed. LY344864, a selective HTR1F agonist, induces MB in renal proximal tubules as previously reported (Gibbs et al., Am J Physiol Renal Physiol, 2018, 314(2), F260-F268). Vehicle and pharmacological reagents were added at the 24 h time point. Electron microscopy was used to assess mitochondrial morphology, number, and autolysosomes. Seahorse Bioscience XF-96 extracellular flux analyzer was used to measure maximal mitochondrial oxygen consumption rates (FCCP-OCR), a functional marker of MB. Results: LY344864 treatment increased FCCP-OCR, phosphorylation of protein kinase B (AKT), peroxisome proliferator-activated receptor γ coactivator-1alpha (PGC-1α), and mitochondrial number after 24 h. These endpoints decreased to baseline 24 h after LY344864 removal. Treatment with ROC-325, an autophagy inhibitor, increased Sequestosome-1 (SQSTM1/P62) and microtubule-associated protein-1 light chain 3 (LC3B) after 24 h of treatment. Also, ROC-325 treatment sustained the elevated mitochondrial number after LY344864 pre-treatment and removal. Conclusion: These data revealed that inhibition of autophagy extends elevated mitochondrial number and function by preventing the lysosomal degradation of mitochondria after the removal of LY344864.

High-Density Lipoproteins at the Interface between the NLRP3 Inflammasome and Myocardial Infarction

Despite significant therapeutic advancements, morbidity and mortality following myocardial infarction (MI) remain unacceptably high. This clinical challenge is primarily attributed to two significant factors: delayed reperfusion and the myocardial injury resulting from coronary reperfusion. Following reperfusion, there is a rapid intracellular pH shift, disruption of ionic balance, heightened oxidative stress, increased activity of proteolytic enzymes, initiation of inflammatory responses, and activation of several cell death pathways, encompassing apoptosis, necroptosis, and pyroptosis. The inflammatory cell death or pyroptosis encompasses the activation of the intracellular multiprotein complex known as the NLRP3 inflammasome. High-density lipoproteins (HDL) are endogenous particles whose components can either promote or mitigate the activation of the NLRP3 inflammasome. In this comprehensive review, we explore the role of inflammasome activation in the context of MI and provide a detailed analysis of how HDL can modulate this process.