Mitochondrial dynamics in type 2 diabetes: Pathophysiological implications

Evolving perspectives on evaluating obesity: from traditional methods to cutting-edge techniques

Objective: This review examines the evolution of obesity evaluation methods, from traditional anthropometric indices to advanced imaging techniques, focusing on their clinical utility, limitations, and potential for personalized assessment of visceral adiposity and associated metabolic risks.

Methods: A comprehensive analysis of existing literature was conducted, encompassing anthropometric indices (BMI, WC, WHR, WHtR, NC), lipid-related metrics (LAP, VAI, CVAI, mBMI), and imaging technologies (3D scanning, BIA, ultrasound, DXA, CT, MRI). The study highlights the biological roles of white, brown, and beige adipocytes, emphasizing visceral adipose tissue (VAT) as a critical mediator of metabolic diseases.

Conclusion: Although BMI and other anthropometric measurements are still included in the guidelines, indicators that incorporate lipid metabolism information can more accurately reflect the relationship between metabolic diseases and visceral obesity. At the same time, the use of more modern medical equipment, such as ultrasound, X-rays, and CT scans, allows for a more intuitive assessment of the extent of visceral obesity.

BDH1 reduces apoptosis and alleviates mitochondrial damage of cardiomyocytes under high glucose condition as a downstream target of miR-125b

Diabetes is a chronic metabolic disease, characterized prominently by a persistent elevation of blood glucose level beyond the normal range. Prolonged hyperglycemia exerts deleterious effects on systems and organs of the body, leading to complications like diabetic cardiomyopathy (DCM). Our study commenced by screening the gene 3-hydroxybutyrate dehydrogenase 1 (BDH1) with low expression in DCM via Gene Expression Omnibus (GEO) analysis (GSE123975). Subsequently, we cultivated AC16 human cardiomyocytes in high glucose (HG) conditions and observed a reduction in BDH1 expression. To further investigate, we constructed plasmids for BDH1 knockdown (sh-BDH1) and overexpression (OE-BDH1). When BDH1 was overexpressed in HG-treated AC16 cells, apoptosis decreased, with reduced Bax/Bcl2 and Cleaved Caspase3/Caspase3 ratios. Additionally, mitochondrial ROS decreased, while expression of mitochondrial fusion protein mitofusin 2 (MFN2) and mitochondrial repair protein folliculin interacting protein 1 (FNIP1) increased. Notably, microRNA-125 b was upregulated in AC16 cells with hyperglycemia, and dual-luciferase reporter assays confirmed its targeting and inhibition of BDH1 mRNA. Inhibition of miR-125 b in HG-treated AC16 cells reversed apoptosis and mitochondrial ROS increase, yet simultaneous inhibition of both miR-125 b and BDH1 abolished this effect. In addition, we overexpressed BDH1 in diabetic mice by tail vein injection, and proved that overexpression of BDH1 could reduce cardiomyocyte apoptosis in vivo. In conclusion, our findings suggested that the miR-125-BDH1 axis could inhibit the production of mitochondrial ROS, promote mitochondrial fusion and repair, and reduce the apoptosis and mitochondrial damage of cardiomyocytes in HG condition.

Dietary therapy to halt the progression of diabetes to diabetic kidney disease

Diabetic Kidney Disease (DKD) is a common and serious complication of diabetes, particularly Type 2 Diabetes Mellitus (T2DM), which significantly contributes to patient morbidity and mortality. The limitations of traditional treatments like ACE inhibitors and ARBs in managing DKD progression highlight the need for innovative therapeutic strategies. This review examines the impact of various dietary patterns, such as the Mediterranean diet, ketogenic diet, intermittent fasting, DASH diet, and vegetarian diet, on the management of DKD. Evidence suggests these diets can halt the progression of DKD, although further research is needed to confirm their long-term effectiveness and safety. Personalized dietary approaches tailored to individual needs may enhance outcomes for DKD patients.

Piezo1 deletion mitigates diabetic cardiomyopathy by maintaining mitochondrial dynamics via ERK/Drp1 pathway

OBJECTIVE

Increasing evidence highlights the critical role of Piezo1 in cardiovascular diseases, with its expression upregulated in diabetic heart. However, the involvement of Piezo1 in the pathogenesis of diabetic cardiomyopathy (DCM) remains unclear. This study aims to elucidate the regulatory role of Piezo1 in mitochondrial dynamics within the context of DCM and to investigate the underlying mechanisms.

METHODS

We constructed cardiac-specific knockout of Piezo1 (Piezo1∆Myh6) mice. Type 1 diabetes was induced using streptozotocin (STZ) injection while type 2 diabetes was established through a high-fat diet combined with STZ. Echocardiography assessed left ventricular function, histological evaluations used HE and Masson staining to examine cardiac pathology in Piezo1fl/fl controls, Piezo1∆Myh6 controls, Piezo1fl/fl diabetic and Piezo1∆Myh6 diabetic mice. Mitochondrial function including oxygen species level, mitochondrial morphology, and respiration rate were also assessed.

RESULTS

Our findings revealed that Piezo1 expression was upregulated in the myocardium of diabetic mice and in high-glucose-treated cells. Cardiac-specific knockout of Piezo1 improved cardiac dysfunction and ameliorated cardiac fibrosis in diabetic mice. Moreover, Piezo1 deficiency also attenuated mitochondrial impairment. Piezo1fl/fl diabetic mice exhibited increased calpain activity and excessive mitochondrial fission mediated by Drp1 and obvious reduced fusion; however, Piezo1 deficiency restored calpain levels and mitochondrial dysfunction. These observations were also corroborated in H9C2 cells and neonatal mouse cardiomyocytes. Cardiac-specific knockout of Piezo1 increased phosphorylation of Drp1 and ERK1/2 in vivo and in vitro. Piezo1 knockout or treatment with inhibitor improved mitochondrial function.

CONCLUSIONS

This study provides the first evidence that Piezo1 is elevated in DCM through the modulation of mitochondrial dynamics, which is reversed by Piezo1 deficiency. Thus, Piezo1 inhibition may provide a promising therapeutic strategy for the treatment of DCM.

An injectable and photocurable methacrylate-silk fibroin/prussian blue nanozyme hydrogel with antioxidant and pyroptosis suppression properties for cartilage regeneration

Cartilage injury is one of the most prevalent, distressing, and disabling chronic conditions affecting degenerative joints worldwide; however, its underlying mechanisms remain elusive. Various biomaterials have been widely employed in the treatment of articular cartilage (AC) injuries. Despite these efforts, the key role of reactive oxygen species (ROS) as primary instigators of pyroptosis, combined with the lack of effective interventions, often results in suboptimal cartilage repair outcomes. Thus, there is an urgent need for the development of novel antioxidants and inflammasome-mediated pyroptosis modulators to create a favorable microenvironment for cartilage repair. In this study, we synthesized Prussian blue nanoparticles (PBNPs) capable of efficiently scavenging ROS. In vitro, these PBNPs protected against oxidative stress-induced cytotoxicity, preserved mitochondrial integrity, reduced the activation of nucleotide-binding domain and leucine-rich repeat family pyrin domain-containing 3 (NLRP3) inflammasomes and caspase-1, and subsequently downregulated gasdermin D (GSDMD) cleavage and inflammatory factor production, leading to the inhibition of chondrocyte pyroptosis. To extend these findings in vivo, we developed an injectable and photocurable methacrylate-silk fibroin (SilMA) hydrogel with homogeneously incorporated PBNPs, designed for releasing PBNPs. The resulting PBNPs@SilMA hydrogel decreased ROS production, reduced chondrocyte pyroptosis, and supported chondrocyte proliferation and matrix secretion, subsequently improved AC repair. Overall, our results indicate that the PBNPs@SilMA platform holds significant promise as a therapeutic strategy for AC injury.

Exposure to aircraft noise exacerbates cardiovascular and oxidative damage in three mouse models of diabetes

AIMS

Epidemiology links noise to increased risk of metabolic diseases like diabetes and obesity. Translational studies in humans and experimental animals showed that noise causes reactive oxygen species (ROS)-mediated cardiovascular damage. The interaction between noise and diabetes, specifically potential additive adverse effects, remains to be determined.

METHODS AND RESULTS

C57BL/6 mice were treated with streptozotocin (i.p. injections, 50 mg/kg/day for 5 days) to induce type 1 diabetes mellitus, with S961 (subcutaneous osmotic mini-pumps, 0.57 mg/kg/day for 7 days) or fed a high-fat diet (HFD, 20 weeks) to induce type 2 diabetes mellitus. Control and diabetic mice were exposed to aircraft noise to an average sound pressure level of 72 dB(A) for 4 days. While body weight was unaffected, noise reduced insulin production in all diabetes models. The oral glucose tolerance test showed only an additive aggravation by noise in the HFD model. Noise increased blood pressure and aggravated diabetes-induced aortic, mesenteric, and cerebral arterioles' endothelial dysfunction. ROS formation in cerebral arterioles, the aorta, the heart, and isolated mitochondria was consistently increased by noise in all models of diabetes. Mitochondrial respiration was impaired by diabetes and noise, however without additive effects. Noise increased ROS and caused inflammation in adipose tissue in the HFD model. RNA-sequencing data and alteration of gene pathway clusters also supported additive damage by noise in the setting of diabetes.

CONCLUSION

In all three models of diabetes, aircraft noise exacerbates oxidative stress, inflammation, and endothelial dysfunction in mice with pre-existing diabetes. Thus, noise may potentiate the already increased cardiovascular risk in diabetic patients.

Long term exposure to multiple environmental stressors induces mitochondrial dynamics imbalance in testis: Insights from metabolomics and transcriptomics

Long-term exposure to adverse environment stressors (e.g. noise pollution, temperature, and crowding) impaired human health. However, research on the toxic effects of adverse environmental stressors on the male reproductive system is limited. This study employed integrated phenomics, metabolomics, and transcriptomics to investigate physiological disturbances in the testis of mice exposed to multiple adverse environmental stressors for two months. Phenotypic studies indicated that long-term environmental stimuli resulted in significant damage to the blood-testis barrier (BTB) and testes, evidenced by reduced testicular index, disrupted testicular tissue structure, abnormal tight junction protein expression, and spermatozoa abnormalities. Comprehensive multi-omics analysis revealed that long-term exposure to environmental stressors disrupted the BTB and testes, which was associated with mitochondrial metabolism disorders, including oxidative phosphorylation and fatty acid beta-oxidation, as well as glutathione and lipid metabolism alterations. Among these dysregulated pathways, significant alterations were observed in the critical regulators of mitochondrial fusion (MFN2) and fission (DRP1) within the BTB. Specifically, corticosterone treatment decreased tight junction protein expression, increased reactive oxygen species (ROS) levels, and impaired mitochondrial morphology and function, as evidenced by reduced mitochondrial membrane potential, elevated calcium ion concentration, and shortened mitochondrial length and network in vitro. Moreover, inhibiting DRP1 with Mdivi-1 or overexpressing MFN2 mitigated the corticosterone-induced reduction of tight junctions and mitochondrial dysregulation in TM4 cells. Collectively, maintaining mitochondrial homeostasis emerges as a promising strategy to alleviate the BTB and testicular injury induced by long-term exposure to multiple environmental stressors.

Ubiquitination regulation of mitochondrial homeostasis: a new sight for the treatment of gastrointestinal tumors

Mitochondrial homeostasis (MH) refers to the dynamic balance of mitochondrial number, function, and quality within cells. Maintaining MH is significant in the occurrence, development, and clinical treatment of Gastrointestinal (GI) tumors. Ubiquitination, as an important post-translational modification mechanism of proteins, plays a central role in the regulation of MH. Over the past decade, research on the regulation of MH by ubiquitination has focused on mitochondrial biogenesis, mitochondrial dynamics, Mitophagy, and mitochondrial metabolism during these processes. This review summarizes the mechanism and potential therapeutic targets of ubiquitin (Ub)-regulated MH intervention in GI tumors.

Spermine alleviates myocardial cell aging by inhibiting mitochondrial oxidative stress damage

BACKGROUND

Myocardial aging, involving oxidative stress, mitochondrial dysfunction, and cellular senescence, is crucial to DOX - induced heart failure. DOX has dose - dependent cardiotoxicity. Sper a natural polyamine with antioxidant and anti - aging effects, remains unstudied in this context.

AIM

This study hypothesizes Sper can alleviate DOX - induced heart failure by curbing myocardial aging and oxidative stress. It aims to assess Sper's protective impacts on cardiac function, pathology, oxidative stress, mitochondrial damage, and aging in a rat model, using captopril as a control.

METHODS

80 male Sprague Dawley rats were assigned to 8 groups: normal control, 150 mg/kg Sper, DOX, and DOX +10/50/100/150 mg/kg Sper, DOX +30 mg/kg captopril. DOX was given intraperitoneally at 15 mg/kg total dose, while Sper or captopril was administered daily via gavage for six weeks. Cardiac function was evaluated using echocardiography, and histopathological changes, oxidative stress markers, mitochondrial damage, and myocardial aging were assessed via H&E staining, immunofluorescence, Western blot, and electron microscopy.

RESULTS

Sper boosted cardiac function in DOX - treated rats, upping EF and SV, and lessening cardiac tissue damage. It cut oxidative stress by reducing MDA levels and boosting SOD activity. Sper also eased mitochondrial damage by enhancing mitochondrial membrane potential and cutting mitochondrial fission proteins (Drp1 and Fis1). Plus, Sper held back myocardial aging by trimming β - galactosidase activity and downregulating p - P53 and p21 expression. At 150 mg/kg/day, Sper worked much like 30 mg/kg/day captopril.

CONCLUSION

Sper effectively eased DOX - induced heart failure by targeting oxidative stress and aging, showing potential as an adjunct therapy for DOX - related cardiotoxicity. Future research should explore Sper's molecular mechanisms and clinical efficacy.

Metabolism Meets Translation: Dietary and Metabolic Influences on tRNA Modifications and Codon Biased Translation

Transfer RNA (tRNA) is not merely a passive carrier of amino acids, but an active regulator of mRNA translation controlling codon bias and optimality. The synthesis of various tRNA modifications is regulated by many "writer" enzymes, which utilize substrates from metabolic pathways or dietary sources. Metabolic and bioenergetic pathways, such as one-carbon (1C) metabolism and the tricarboxylic acid (TCA) cycle produce essential substrates for tRNA modifications synthesis, such as S-Adenosyl methionine (SAM), sulfur species, and α-ketoglutarate (α-KG). The activity of these metabolic pathways can directly impact codon decoding and translation via regulating tRNA modifications levels. In this review, we discuss the complex interactions between diet, metabolism, tRNA modifications, and mRNA translation. We discuss how nutrient availability, bioenergetics, and intermediates of metabolic pathways, modulate the tRNA modification landscape to fine-tune protein synthesis. Moreover, we highlight how dysregulation of these metabolic-tRNA interactions contributes to disease pathogenesis, including cancer, metabolic disorders, and neurodegenerative diseases. We also discuss the new emerging field of GlycoRNA biology drawing parallels from glycobiology and metabolic diseases to guide future directions in this area. Throughout our discussion, we highlight the links between specific modifications, their metabolic/dietary precursors, and various diseases, emphasizing the importance of a metabolism-centric tRNA view in understanding many pathologies. Future research should focus on uncovering the interplay between metabolism and tRNA in specific cellular and disease contexts. Addressing these gaps will guide new research into novel disease interventions.

Metabolically unhealthy adipose tissue is characterized by reductions in mitochondrial size and function

OBJECTIVE

Adipose function, not mass, underpins metabolic health. Lean and obese nonhuman primates (NHPs) naturally develop metabolic syndrome. Mitochondria-related measures in subcutaneous adipose tissue (SQ AT) and peripheral blood mononuclear cells may elucidate differences that transcend adiposity measures.

METHODS

Obesity statuses ranged from very lean to severely obese (<9%->50%, n = 44), which were equivalent in healthy or unhealthy NHPs (metabolic syndrome score difference, p < 0.001). We evaluated SQ AT histology, electron microscopy, tissue proteins, and bioenergetics.

RESULTS

Unhealthy adipocytes had mitochondria one-half the size of healthy adipocytes (p < 0.01), whereas adipocyte cell sizes were comparable. Consistent with small mitochondria, we saw deficiencies in mitochondrial fusion and quality-control proteins in SQ AT from unhealthy NHPs (all p < 0.05). Smaller mitochondria in unhealthy adipocytes were consistent with low SQ AT tissue respiration (p < 0.05). Mitochondrial size was specifically reduced with unhealthiness, as mitochondrial abundance, size, and related metrics were unrelated to adiposity. Isolated stromal vascular cells showed comparable respirometry profiles, substantiating specificity of adipocyte-related mitochondrial defects. Peripheral blood mononuclear cell bioenergetic indices were increased in unhealthy NHPs, indicative of immune cell activation, and correlated to SQ AT inflammatory cytokines.

CONCLUSIONS

We conclude that targeting mitochondrial fusion processes would be a rational strategy to improve metabolic health, independent of total fat mass.

Regulatory Role of Bioactive Compounds from Natural Spices on Mitochondrial Function

Natural spices have gained much attention for their aromatic and pungent flavors as well as their multiple beneficial health effects. As complex organelles that play a central role in energy production, stress response control, cell signal transduction, and metabolism regulation, mitochondria could be regulated by many bioactive components in spices. In this review, the role of mitochondria in maintaining cellular and metabolism homeostasis is summarized. The regulatory effects of mitochondrial function by major bioactive compounds from natural spices are evaluated, including capsaicin, 6-gingerol, 6-shogaol, allicin, quercetin, curcumin, tetrahydrocurcumin, and cinnamaldehyde. The underlying molecular mechanisms are also discussed. This work could enhance our understanding toward health-promoting properties of spice compounds as well as provide new insights into the prevention and treatment of disorders associated with mitochondrial dysfunctions by those nutraceuticals.

Emerging roles of the acid sphingomyelinase/ceramide pathway in metabolic and cardiovascular diseases: Mechanistic insights and therapeutic implications

Metabolic diseases have emerged as a leading cause of mortality from non-communicable diseases, posing a significant global public health challenge. Although the association between ceramides (Cers) and metabolic diseases is well-established, the role of the acid sphingomyelinase (ASMase)/Cer pathway in these diseases remains underexplored. This review synthesizes recent research on the biological functions, regulatory mechanisms, and targeted therapies related to the ASMase/Cer pathway in metabolic conditions, including obesity, diabetes, non-alcoholic fatty liver disease, and cardiovascular disease. The effects of the ASMase/Cer pathway on metabolic disease-related indicators, such as glycolipid metabolism, insulin resistance, inflammation, and mitochondrial homeostasis are elucidated. Moreover, this article discusses the therapeutic strategies using ASMase/Cer inhibitors for inverse prevention and treatment of these metabolic diseases in light of the possible efficacy of blockade of the ASMase/Cer pathway in arresting the progression of metabolic diseases. These insights offered herein should provide insight into the contribution of the ASMase/Cer pathway to metabolic diseases and offer tools to develop therapeutic interventions for such pathologies and their severe complications.

Caveolin-3: therapeutic target for diabetic myocardial ischemia/reperfusion injury

Myocardial ischemia/reperfusion (I/R) injury is a major global health problem with high rates of mortality and disability, which is more severe in patients with diabetes. Substantial researches have documented that diabetic myocardium are more susceptible to I/R injury, but many current intervention strategies against myocardial I/R injury have limited effectiveness in diabetic hearts. Caveolin-3 (Cav-3) is the signature protein of caveolae and serves as a signal integration and transduction platform in the plasma membrane of cardiomyocytes, which plays a vital role in myocardial functions, metabolism and protection of multiple conditioning strategies against I/R injury. Nevertheless, numerous studies have revealed that the expression of Cav-3 is impaired in diabetic hearts, which contributes to increased vulnerability of myocardium to I/R injury and resistance to protective conditioning strategies. In this review, we outline the basic structure and function of Cav-3, emphatically present the unique role of Cav-3 as a signal integration and transduction element in diabetic myocardial I/R injury and discuss its therapeutic perspective in strategies against myocardial I/R injury in diabetes.

The Role of Placental MFF-Mediated Mitochondrial Fission in Gestational Diabetes Mellitus

Introduction

Gestational diabetes mellitus (GDM) refers to hyperglycemia first recognized during pregnancy, characterized by decreased insulin sensitivity and impaired glucose metabolism. Dynamic fusion and fission processes within mitochondria play critical roles in maintaining glucose metabolism homeostasis. Given the fundamental role of mitochondrial fission factor (MFF) in mitochondrial fission, the intention of this study was to investigate mitochondrial dynamics in the placentae of GDM patients and explore the role of MFF in the etiopathogenesis and progression of GDM through the modulation of glucose metabolism and insulin resistance.

Methods

40 Placental tissues were obtained from pregnant women undergoing cesarean section with GDM (n=20) and those with normoglycemia (n=20). To mimic the intrauterine high glucose environment, immortalized human-derived first-trimester extravillous trophoblast cells HTR8/SVneo were used and treated in a high glucose environment. Immunofluorescence was utilized to analyze MFF expression in placental tissues and mitochondrial length in HTR8/SVneo cells. The expression levels of glucose transporters (GLUTs) and other pivotal proteins involved in mitochondrial dynamics and the insulin signaling pathway, were assessed by Western blotting. Additionally, cellular glucose uptake capacity was determined using a glucose assay kit.

Results

MFF expression was greater in the GDM group than in the normoglycemic group. In a high-glucose environment, the expression of fusion-related proteins OPA1, MFN1 and MFN2 decreased while the expression of DRP1 and MFF increased, indicating that the mitochondrial dynamics of trophoblast cells shift toward fission. Elevated mitochondrial fission hinders the insulin signaling pathway, resulting in a reduction in glucose uptake by HTR8/SVneo cells and a concurrent decrease in GLUT4 expression.

Discussion

Our study demonstrates that MFF-mediated mitochondrial fission inhibits insulin sensitivity and upregulates glucose transport in GDM, which is related to offspring exposure to a hyperglycemic intrauterine environment. These results provide a novel therapeutic target for addressing GDM that may mitigate unfavorable pregnancy outcomes.

SIRT3-Mediated Deacetylation of DRP1K711 Prevents Mitochondrial Dysfunction in Parkinson's Disease

Dysregulation of mitochondrial dynamics is a key contributor to the pathogenesis of Parkinson's disease (PD). Aberrant mitochondrial fission induced by dynamin-related protein 1 (DRP1) causes mitochondrial dysfunction in dopaminergic (DA) neurons. However, the mechanism of DRP1 activation and its role in PD progression remain unclear. In this study, Mass spectrometry analysis is performed and identified a significant increased DRP1 acetylation at lysine residue 711 (K711) in the mitochondria under oxidative stress. Enhanced DRP1K711 acetylation facilitated DRP1 oligomerization, thereby exacerbating mitochondrial fragmentation and compromising the mitochondrial function. DRP1K711 acetylation also affects mitochondrial DRP1 recruitment and fission independent of canonical S616 phosphorylation. Further analysis reveals the critical role of sirtuin (SIRT)-3 in deacetylating DRP1K711, thereby regulating mitochondrial dynamics and function. SIRT3 agonists significantly inhibit DRP1K711 acetylation, rescue DA neuronal loss, and improve motor function in a PD mouse model. Conversely, selective knockout of SIRT3 in DA neurons exacerbates DRP1K711 acetylation, leading to increased DA neuronal damage, neuronal death, and worsened motor dysfunction. Notably, this study identifies a novel mechanism involving aberrant SIRT3-mediated DRP1 acetylation at K711 as a key driver of mitochondrial dysfunction and DA neuronal death in PD, revealing a potential target for PD treatment.

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

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

Structure-activity relationship study of novel evodiamine amino acid conjugates with potent anti-colorectal cancer efficacy

Evodiamine has been a promising lead structure with broad-spectrum antitumor activity. Druggability optimization is the most challenging part of evodiamine-based lead-to-candidate campaign. Amino acids as building blocks for conjugates are widely incorporated into approved drug and drug candidates, demonstrating highly attractive druggability. Herein, a series of evodiamine amino acid conjugates were designed and synthesized based on the evodiamine lead compound (±)-8b discovered in our previous work. The structure-activity relationship (SAR) studies culminated in the identification of a promising conjugate (-)-15h featuring a N-Boc-l-glutamine group and a chiral carbon atom (sinister), which exhibited nanomolar antiproliferative activity against LoVo and RKO colorectal cancer cells. Moreover, (-)-15h could inhibit topoisomerases I, arrest the cell cycle in the G2/M phase, and induce apoptosis. Importantly, (-)-15h (tumor growth inhibition rate was 82.53 % in 40 mpk) showed better efficacy and tolerability to that of parent compound (-)-8b (tumor growth inhibition rate was 51.22 % in 40 mpk) in LoVo xenograft model. Further, (-)-15h (tumor growth inhibition rate was 70.09 % in 40 mpk) showed comparable efficacy and better tolerability to that of topotecan (tumor growth inhibition rate was 70.67 % in 0.5 mpk) in HT-29 xenograft model. Collectively, this study further provided a strong scientific basis for amino acid-based structural modifications and a drug lead for anti-colorectal cancer applications.

SPP1-ITGα5/β1 Accelerates Calcification of Nucleus Pulposus Cells by Inhibiting Mitophagy via Ubiquitin-Dependent PINK1/PARKIN Pathway Blockade

Low back pain (LBP) caused by nucleus pulposus degeneration and calcification leads to great economic and social burden worldwide. Unexpectedly, no previous studies have demonstrated the association and the underlying mechanism between nucleus pulposus tissue degeneration and calcification formation. Secreted Phosphoprotein 1 (SPP1) exerts crucial functions in bone matrix mineralization and calcium deposition. Here, a novel function of SPP1 is reported, namely that it can aggravate nucleus pulposus cells (NPs) degeneration by negatively regulating extracellular matrix homeostasis. The degenerated NPs have a higher mineralization potential, which is achieved by SPP1. Mechanistically, SPP1 can accelerate the degeneration of nucleus pulposus cells by activating integrin α5β1 (ITGα5/β1), aggravating mitochondrial damage and inhibiting mitophagy. SPP1-ITGα5/β1 axis inhibits mitophagy by PINK1/PARKIN pathway blockade. In conclusion, SPP1 activates ITGα5/β1 to inhibit mitophagy, accelerates NPs degeneration, and induces calcification, thereby leading to intervertebral disc degeneration (IVDD) and calcification, identifying the potentially unknown mechanism and relationship between IVDD and calcification. Important insights are provided into the role of SPP1 in nucleus pulposus calcification in IVDD by inducing nucleus pulposus cell senescence through inhibition of mitophagy and may help develop potential new strategies for IVDD treatment.

The Effects of Glucagon-Like Peptide-1 Receptor Agonists on Mitochondrial Function Within Skeletal Muscle: A Systematic Review

BACKGROUND

Obesity is a chronic disease associated with increased risk of multiple metabolic and mental health-related comorbidities. Recent advances in obesity pharmacotherapy, particularly with glucagon-like peptide-1 (GLP-1) receptor agonists (RAs), have the potential to transform obesity and type 2 diabetes mellitus (T2DM) care by promoting marked weight loss, improving glycaemic control and addressing multiple obesity-related comorbidities, with added cardio-renal benefits. Dual agonists combining GLP-1 with other enteropancreatic hormones such as glucose-dependent insulinotropic polypeptide (GIP) have also been developed in recent years, leading to greater weight loss than using GLP-1 RAs alone. However, up to 40% of the weight lost with GLP-1 RAs comes from lean body mass, raising concerns about potential adverse effects on skeletal muscle function. Mitochondrial dysfunction, characterized by reduced mitochondrial size and activity, is prevalent in individuals with obesity and T2DM and is a known contributor to muscle wasting in ageing and some chronic diseases. This systematic review investigates the impact of GLP-1-based therapies on skeletal muscle mitochondrial function in individuals with obesity and T2DM or in related animal and cell models.

METHODS

A comprehensive search of MEDLINE, Scopus, CINAHL and clinicaltrials.gov was conducted. Inclusion criteria included randomized controlled trials, randomized crossover trials, cluster randomized control trials and basic science studies involving any GLP-1 RA or GLP-1/GIP dual agonist. Outcomes of interest were skeletal muscle respiratory function either in the form of measurements of mass, number, content, oxidative capacity/respiratory function, mitochondrial dynamics, mitochondrial biogenesis and mitophagy.

RESULTS

Eight studies were eligible for analysis; no human studies were identified. All of the included studies used GLP-1 RAs (single agonists) as intervention. The emerging evidence suggests that GLP-1 RAs increase mitochondrial area, number and morphology (i.e., reduces swelling). Data are conflicting on the effect of GLP-1 RAs upon mitochondrial mass, respiration and the expression of uncoupling proteins and PGC-1α. Data also demonstrate muscle specific (i.e., soleus vs. extensor digitorum longus) responses to GLP-1 RAs.

CONCLUSION

GLP-1 RAs appear to have a positive effect upon mitochondria area, number and morphology, but effects upon other aspects of mitochondrial health remain inconclusive. Data are very limited and solely presented in animal and in vitro models. Future studies should be conducted in human populations in order to begin to understand the effect of GLP-1 RAs and GLP-1-based therapies on human skeletal muscle mitochondria.

Icariside II relieves radiation enteritis by regulating PINK/Parkin-mediated mitophagy

Radiation enteritis (RE) is one of the major side effects of radiotherapy. So far, there are no effective drugs for preventing the disease process. Icariside II (ICS II) is a highly efficient monomer compound extracted and purified from the classic Chinese medicinal herb Epimedium. It has anti-inflammatory, antioxidant, and immunomodulatory effects. However, the role and mechanism of ICS II on radiation enteritis are not clear. Here, we reveal the role of ICS II in radiation enteritis by using an irradiation-induced rat model and a human colorectal cancer cell (CaCo2). After intragastric administration, HE staining and Tunel staining to observe the histopathological changes in the colon, and TEM to observe the ultrastructure of mitochondria; The antioxidant indexes and mitochondrial function-related markers of colon tissues were determined; DCFH-DA fluorescent probe were used to detect the cellular ROS level, JC-1 staining was used to detect the changes in mitochondrial membrane potential, and Western Blot was used to detect related protein expression. The results showed that ICS II could reduce intestinal injury and attenuate the radiation-induced oxidative stress and inflammatory response. In addition, ICS II could effectively attenuate mitochondrial damage and activate mitochondrial autophagy in rats. Mechanistically, ICS II activates mitochondrial autophagy-related protein expression to rescue radiation-induced damage to mitophagy. We found that by inhibiting mitophagy, the therapeutic effect of ICS II can be eliminated and our data suggest that ICS II may be a new and effective drug candidate for the treatment of radiation enteritis.

Type 2 Diabetes Mellitus: New Pathogenetic Mechanisms, Treatment and the Most Important Complications

Type 2 diabetes mellitus (T2DM), a prevalent chronic disease affecting over 400 million people globally, is driven by genetic and environmental factors. The pathogenesis involves insulin resistance and β-cell dysfunction, mediated by mechanisms such as the dedifferentiation of β-cells, mitochondrial dysfunction, and oxidative stress. Treatment should be based on non-pharmacological therapy. Strategies such as increased physical activity, dietary modifications, cognitive-behavioral therapy are important in maintaining normal glycemia. Advanced therapies, including SGLT2 inhibitors and GLP-1 receptor agonists, complement these treatments and offer solid glycemic control, weight control, and reduced cardiovascular risk. Complications of T2DM, such as diabetic kidney disease, retinopathy, and neuropathy, underscore the need for early diagnosis and comprehensive management to improve patient outcomes and quality of life.

SIRT3 mitigates high glucose-induced damage in retinal microvascular endothelial cells via OPA1-mediated mitochondrial dynamics

Oxidative stress in endothelial cells is pivotal in diabetic retinopathy (DR), with mitochondrial homeostasis being crucial to mitigate this stress. This study explored the roles of mitochondrial sirtuins (SIRTs) in high glucose (HG)-induced oxidative stress, related endothelial impairment, and mitochondrial homeostasis damage in rat retinal microvascular endothelial cells (RMECs). RMECs were cultured under HG or equivalent osmotic conditions. Cell viability was assessed using the Cell Counting Kit-8 assay, whereas cell death and survival were determined via calcein-AM/propidium iodide double staining. Reactive oxygen species (ROS) levels were measured using 2',7'-dichlorofluorescein fluorescence. Expression of mitochondrial SIRTs3-5 and key mitochondrial homeostasis molecules was quantified by the quantitative real-time polymerase chain reaction and confirmed by western blotting. Mitochondrial morphology was evaluated using electron microscopy and the MitoTracker fluorescent probe. A SIRT3-overexpressing RMEC line was constructed to assess the role of SIRT3 in oxidative stress and mitochondrial dynamics. After 48 h of HG exposure, cell viability was significantly reduced, with a concomitant increase in cell death and ROS levels, alongside a marked decrease in SIRT3 expression and molecules associated with mitochondrial dynamics. SIRT3 overexpression reversed these effects, particularly increasing the mitochondrial fusion-related molecule, optic atrophy 1 (OPA1). However, the OPA1 inhibitor, MYLS22, blocked the protective effect of SIRT3, leading to more dead cells, a higher ROS level, and intensified mitochondrial fragmentation. These results suggest that SIRT3 is involved in HG-induced imbalanced mitochondrial dynamics of endothelial cells in DR, potentially through the OPA1 pathway.

Cilostazol counteracts mitochondrial dysfunction in hepatic encephalopathy rat model: Insights into the role of cAMP/AMPK/SIRT1/ PINK-1/parkin hub and p-CREB /BDNF/ TrkB neuroprotective trajectory

A devasting stage of chronic hepatic dysfunction is strictly correlated with neurological impairment, signifying hepatic encephalopathy (HE). HE is a multifactorial condition; therefore, hyperammonemia, oxidative stress, neuroinflammation, and mitochondrial dysfunction interplay in HE's progressive development. Cilostazol (Cilo) has shown promising neuroprotective and hepatoprotective effectiveness in different neuronal and hepatic disorders; however, its efficiency against HE hasn't yet been explored. This study aimed to investigate the protective role of Cilo against thioacetamide (TAA)-induced HE in rats targeting mitochondrial dysfunction via modulation of Adenosine monophosphate-activated protein kinase (AMPK)/Silent information regulator 1 (SIRT1) dependent pathways. Rats were allocated into three groups: the normal control group, the TAA group received (100 mg/kg, three times per week, for six weeks) to induce HE, and the Cilo group received (Cilo 100 mg/kg/day for six weeks, oral gavage) concurrently with TAA. Cilo counteracted HE indicated in the enhancement of cognitive impairment and the motor performance of rats (P < 0.0001), modulation AMPK/SIRT1signaling pathway causing reduction of NF-kB p65 (P < 0.0001) evoked inflammation along with histopathological alterations and glial fibrillary acidic protein (GFAP) immunoreactivity (P < 0.0001), restoration nuclear factor E2-related factor 2 (Nrf2) (P < 0.0001) antioxidant effects, reduction of Bax and elevation of Bcl2 immunoreactivity (P < 0.0001) in addition to boosting mitochondrial biogenesis by upregulation of PTEN-induced kinase-1 (PINK-1)/Parkin (P < 0.0001)and restoration of Brain-derived neurotrophic factor (BDNF) (P = 0.0002)/tropomyosin-related kinase B (TrkB) (P < 0.0001)/cAMP response element-binding (CREB) (P < 0.0001) neuroprotective axis. Collectively, Cilo activates the SIRT1 trajectory to abridge mitochondrial dysfunction invigorated in the HE rat model via restoration of mitochondrial hemostasis.

SENP1 prevents high fat diet-induced non-alcoholic fatty liver diseases by regulating mitochondrial dynamics

Mitochondrial dynamics plays a crucial role in the occurrence and development of non-alcoholic fatty liver diseases (NAFLD). SENP1, a SUMO-specific protease, catalyzes protein de-SUMOylation and involves in various physiological and pathological processes. However, the exact role of SENP1 in NAFLD remains unclear. Therefore, we investigated the regulatory role of SENP1 in mitochondrial dynamics during the progression of NAFLD. In the study, the NAFLD in vivo model induced by high fat diet (HFD) and in vitro model induced by free fatty acids (FFA) were established to investigate the role and underlying mechanism of SENP1 through detecting mitochondrial morphology and dynamics. Our results showed that the down-regulation of SENP1 expression and the mitochondrial dynamics dysregulation occurred in the NAFLD, evidenced as mitochondrial fragmentation, up-regulation of p-Drp1 ser616 and down-regulation of MFN2, OPA1. However, over-expression of SENP1 significantly alleviated the NAFLD, rectified the mitochondrial dynamics disorder, reduced Cyt-c release and ROS levels induced by FFA or HFD; moreover, the over-expression of SENP1 also reduced the SUMOylation levels of Drp1 and prevented the Drp1 translocation to mitochondria. Our findings suggest that the possible mechanisms of SENP1 were through rectifying the mitochondrial dynamics disorder, reducing Cyt-c release and ROS-mediated oxidative stress. The findings would provide a novel target for the prevention and treatment of NALFD.

Sodium butyrate improves cognitive dysfunction in high-fat diet/ streptozotocin-induced type 2 diabetic mice by ameliorating hippocampal mitochondrial damage through regulating AMPK/PGC-1α pathway

Cognitive dysfunction is an important comorbidity of type 2 diabetes mellitus (T2DM). Sodium butyrate (NaB) is a short-chain fatty acid and has an effect improving T2DM-associated cognitive dysfunction. Using a high-fat diet (HFD)/streptozotocin (STZ)-induced T2DM mouse model, the present study investigated the mechanism involved in the beneficial effect of butyrate on diabetic cognitive dysfunction, with a focus on ameliorating mitochondrial damage through regulating the adenosine monophosphate-activated protein kinase/peroxisome proliferator-activated receptor gamma coactivator 1α (AMPK/PGC-1α) pathway considering the important role of mitochondrial impairments in the occurrence of T2DM-associated cognitive dysfunction. We found, based on reconfirmation of the improvement of NaB on cognitive impairment, that NaB treatment improved damaged synaptic structural plasticity including the decrease in dendritic spine density and downregulation in the expression of postsynaptic density protein 95 and synaptophysin in the hippocampus in the model mice. NaB treatment also ameliorated mitochondrial ultrastructural damage, increased mitochondrial membrane potential and adenosine 5'-triphosphate content, and improved mitochondrial biogenesis and dynamics in the model mice. Furthermore, the expression of phosphorylated AMPK and PGC-1α was upregulated after NaB treatment in the model mice. In particular, the above beneficial effects of NaB were blocked by the inhibition of either AMPK or PGC-1α. In conclusion, NaB treatment improved cognitive impairment and damaged synaptic structural plasticity in the hippocampus by ameliorating damage to mitochondrial morphology and function through regulating the AMPK/PGC-1α pathway in HFD/STZ-induced T2DM mice.

Mitochondrial Function and Oxidative Stress Biomarkers in Diabetic Retinopathy Development: An Analytical Cross-Sectional Study

DR is a complex complication of DM with multiple biochemical pathways implicated in its genesis and progression. Circulating OS and mitochondrial function biomarkers represent potential candidates in the DR staging system. We conducted a comparative cross-sectional study comparing the OS biomarkers: TAC, GR, NOS, CARB, and hydroperoxydes, as well as mitochondrial function biomarkers: ATP synthase and ATPase activity in healthy volunteers, DM w/o DR, Moderate and Severe NPDR, and PDR. TAC is progressively diminished the more DR progresses to its proliferative stages. GR and NOS may function as biomarkers to differentiate the progression from S NPDR to PDR. CARB may correlate with the progression from M NPDR to S NPDR. Hydroperoxide levels were higher in patients with DR compared to DM w/o DR expressing OS in the early development of DR. ATPase activity is increasingly augmented the more DR progresses and may function as a biomarker that reflects the difference between N PDR and PDR, and ATP synthesis was lower the more DR progressed, being significantly lower compared to DM w/o DR. The behavior of OS and mitochondrial function in several stages of DR may aid in the staging and the prognosis of DR.

Identification of a novel 10-hydroxyevodiamine prodrug as a potent topoisomerase inhibitor with improved aqueous solubility for treatment of hepatocellular carcinoma

Natural product evodiamine (Evo) and its synthetic derivatives represent an attractive dual Topo 1/2 inhibitors with broad-spectrum antitumor efficacy. However, the clinical applications of these compounds have been impeded by their poor aqueous solubility. Herein, a series of water-soluble 10-substituted-N(14)-phenylevodiamine derivatives were designed and synthesized. The most potent compound 45 featuring a quaternary ammonium salt fragment achieved robust aqueous solubility and nanomolar potency against a panel of human hepatoma cell lines Huh7, HepG2, SK-Hep-1, SMMC-7721, and SMMC-7721/DOX (doxorubicin-resistant cell). Further studies revealed that 45 could inhibit Topo 1 and Topo 2, induce apoptosis, arrest the cell cycle at the G2/M stage and inhibit the migration and invasion. Compound 45 exhibited potent antitumor activity (TGI = 51.1 %, 10 mg/kg) in the Huh7 xenograft model with acceptable safety profile. In addition, a 21-day long-term dose toxicity study confirmed that the maximum tolerated dose of compound 45 was 20 mg/kg. Overall, this study presented a promising Evo-derived candidate for the treatment of hepatocellular carcinoma.

PACS2/CPT1A/DHODH signaling promotes cardiomyocyte ferroptosis in diabetic cardiomyopathy

OBJECTIVES

The pathophysiology of diabetic cardiomyopathy (DCM) is a phenomenon of great interest, but its clinical problems have not yet been effectively addressed. Recently, the mechanism of ferroptosis in the pathophysiology of various diseases, including DCM, has attracted widespread attention. Here, we explored the role of PACS2 in ferroptosis in DCM through its downregulation of PACS2 expression.

METHODS AND RESULTS

Cardiomyocytes were treated with high glucose and palmitic acid (HGPA), and the detection of cardiomyocyte iron ions, lipid peroxides, and reactive oxygen species (ROS) revealed clear ferroptosis during these treatments. Silencing PACS2 downregulated CPT1A expression and upregulated DHODH expression significantly, reversing HGPA-induced ferroptosis. Further silencing of PACS2 with a CPT1A agonist exacerbated cardiomyocyte ferroptosis while promoting mitochondrial damage in cardiomyocytes. Using a mouse model of type 2 diabetes induced by streptozotocin (STZ) and a high-fat diet (HFD), we found that PACS2 deletion reversed these treatment-induced increases in cellular iron ions, impaired cardiac function, mitochondrial damage and ferroptosis in cardiac muscle tissues.

CONCLUSIONS

The PACS2/CPT1A/DHODH signalling pathway may be involved in ferroptosis in DCM by regulating cardiomyocyte mitochondrial function.

Hormonal orchestra: mastering mitochondria's role in health and disease

Mitochondria is a subcellular organelle involved in the pathogenesis of cellular stress, immune responses, differentiation, metabolic disorders, aging, and death by regulating process of fission, fusion, mitophagy, and transport. However, an increased interest in mitochondria as powerhouse for ATP production, the mechanisms of mitochondria-mediated cellular dysfunction in response to hormonal interaction remains unknown. Mitochondrial matrix contains chaperones and proteases that regulate intrinsic apoptosis pathway through pro-apoptotic Bcl-2 family's proteins Bax/Bak, and Cyt C release, and induces caspase-dependent and independent cells death. Energy and growth regulators such as thyroid hormones have profound effect on mitochondrial inner membrane protein and lipid compositions, ATP production by regulating oxidative phosphorylation system. Mitochondria contain cholesterol side-chain cleavage enzyme, P450scc, ferredoxin, and ferredoxin reductase providing an essential site for steroid hormones biosynthesis. In line with this, neurohormones such as oxytocin, vasopressin, and melatonin are correlated with mitochondrial integrity, displaying therapeutic implications for inflammatory and immune responses. Melatonin's also displayed protective role against oxidative stress and mitochondrial synthesis of ROS, suggesting a defense mechanism against aging-related diseases. An imbalance in mitochondrial bioenergetics can cause neurodegenerative disorders, cardiovascular diseases, and cancers. Hormone-induced PGC-1α stimulates mitochondrial biogenesis via activation of NRF1 and NRF2, which in turn triggers mtTFA in brown adipose and cardiac myocytes. Mitochondria can be transferred through cells merging, exosome-mediated transfer, and tunneling through nanotubes. By delineating the underlying molecular mechanism of hormonal mitochondrial interaction, this study reviews the dynamics mechanisms of mitochondria and its effects on cellular level, health, diseases, and therapeutic strategies targeting mitochondrial diseases.

Upregulated Mitochondrial Dynamics Is Responsible for the Procatabolic Changes of Chondrocyte Induced by α2-Adrenergic Signal Activation

OBJECTIVE

Activation of sympathetic tone is important for cartilage degradation in osteoarthritis (OA). Recent studies reported that sympathetic signals can affect the mitochondrial function of target cells. It is unknown whether this effect exits in chondrocytes and affects chondrocyte catabolism. The contribution of mitochondrial dynamics in the activation of α2-adrenergic signal-mediated chondrocyte catabolism was investigated in this study.

DESIGN

Primary chondrocytes were stimulated with norepinephrine (NE) alone, or pretreated with an α2-adrenergic receptor (Adra2) antagonist (yohimbine) and followed by stimulation with NE. Changes in chondrocyte metabolism and their mitochondrial dynamics were investigated.

RESULTS

We demonstrated that NE stimulation induced increased gene and protein expressions of matrix metalloproteinase-3 and decreased level of aggrecan by chondrocytes. This was accompanied by upregulated mitochondriogenesis and the number of mitochondria, when compared with the vehicle-treated controls. Mitochondrial fusion and fission, and mitophagy also increased significantly in response to NE stimulation. Inhibition of Adra2 attenuated chondrocyte catabolism and mitochondrial dynamics induced by NE.

CONCLUSIONS

The present findings indicate that upregulation of mitochondrial dynamics through mitochondriogenesis, fusion, fission, and mitophagy is responsible for activation of α2-adrenergic signal-mediated chondrocyte catabolism. The hypothesis that "α2-adrenergic signal activation promotes cartilage degeneration in temporomandibular joint osteoarthritis (TMJ-OA) by upregulating mitochondrial dynamics in chondrocytes" is validated. This represents a new regulatory mechanism in the chondrocytes of TMJ-OA that inhibits abnormal activation of mitochondrial fusion and fission is a potential regulator for improving mitochondrial function and inhibiting chondrocyte injury and contrives a potentially innovative therapeutic direction for the prevention of TMJ-OA.

Nicotinamide mononucleotide alleviates seizures via modulating SIRT1-PGC-1α mediated mitochondrial fusion and fission

Both human and animal experiments have demonstrated that energy metabolism dysfunction in neurons after seizures is associated with an imbalance in mitochondrial fusion/fission dynamics. Effective neuronal mitochondrial dynamics regulation strategies remain elusive. Nicotinamide mononucleotide (NMN) can ameliorate mitochondrial functional and oxidative stress in age-related diseases. But whether NMN improves mitochondrial energy metabolism to exert anti-epileptic effects is unclear. This study aims to clarify if NMN can protect neurons from pentylenetetrazole (PTZ) or Mg2+-free-induced mitochondrial disorder and apoptosis via animal and cell models. We established a continuous 30-day PTZ (37 mg/kg) intraperitoneal injection-induced epileptic mouse model and a cell model induced by Mg2+-free solution incubation to explore the neuroprotective effects of NMN. We found that NMN treatment significantly reduced the seizure intensity of PTZ-induced epileptic mice, improved their learning and memory ability, and enhanced their motor activity and exploration desire. At the same time, in vitro and in vivo experiments showed that NMN can inhibit neuronal apoptosis and improve the mitochondrial energy metabolism function of neurons. In addition, NMN down-regulated the expression of mitochondrial fission proteins (Drp1 and Fis1) and promoted the expression of mitochondrial fusion proteins (Mfn1 and Mfn2) by activating the SIRT1-PGC-1α pathway, thereby inhibiting PTZ or Mg2+-free extracellular solution-induced mitochondrial dysfunction, cell apoptosis, and oxidative stress. However, combined intervention of SIRT1 inhibitor, Selisistat, and PGC-1α inhibitor, SR-18292, eliminated the regulatory effect of NMN pre-treatment on mitochondrial fusion and fission proteins and apoptosis-related proteins. Therefore, NMN intervention may be a new potential treatment for cognitive impairment and behavioral disorders induced by epilepsy, and targeting the SIRT1-PGC-1α pathway may be a promising therapeutic strategy for seizures.

Mapping the mitochondrial landscape in T2DM: key findings from 2003-2023

Backgound

T2DM, a chronic metabolic disorder, poses a significant threat to global public health. Mitochondria play a crucial role in the pathogenesis of T2DM. This study intends to investigate the correlation between mitochondria and T2DM over the past two decades (2003-2023) through bibliometric analysis. Its objectives are to pinpoint trends, emphasize research priorities, and establish a foundation for future investigations.

Methods

A literature search was conducted using the SCI-E database. All recorded results were downloaded in plain text format for further analysis. The following terms were analyzed using Vosviewer 1.6.18, citespace 6.3r1, bibliometrix in RStudio (v.4.4.1), and Microsoft Excel 2021: country, institution, author, journal, references, and keywords.

Results

From January 1, 2003 to December 31, 2023, a total of 2,732 articles were retrieved. The United States, China, and Italy contributed most of the records. UNIVERSITY OF CALIFORNIA SYSTEM, INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE MEDICAL INSERM, and US DEPARTMENT OF VETERANS AFFAIRS were the top 3 most productive institutions. rocha milagros, victor victor m had the most publications, followed by roden michael, and petersen kf had the most citations together. DIABETES published the most articles on research on this topic, followed by AMERICAN JOURNAL OF PHYSIOLOGY-ENDOCRINOLOGY AND METABOLISM, DIABETOLOGIA. The key points of this topic are the relationship between mitochondria and T2DM, the skeletal muscle mitochondrial changes observed in T2DM, and the impact of mitochondrial dysfunction on T2DM. Over the past five years, particle dynamics, mitochondrial dysfunction, and mechanism research have emerged as significant focal points in this field.

Conclude

This paper successfully identified the key areas and emerging trends in the relationship between mitochondria and T2DM, thereby offering valuable insights for future research.

Inhibition of mitochondrial over-division by (+)-14,15-Dehydrovincamine attenuates cisplatin-induced acute kidney injury via the JNK/Mff pathway

Cisplatin-induced acute kidney injury (AKI) is characterized by mitochondrial damage and apoptosis, and safe and effective therapeutic agents are urgently needed. Renal tubular epithelial cells, the main site of AKI, are enriched with a large number of mitochondria, which are crucial for the progression of AKI with an impaired energy supply. Vincamine has anti-inflammatory and antioxidant effects in mouse AKI models. As a natural compound derived from Tabernaemontana pandacaqui, (+)-14, 15-Dehydrovincamine and Vincamine differ in structure by only one double bond, and the role and exact mechanism of (+)-14, 15-Dehydrovincamine remains to be elucidated in AKI. The present study demonstrated that (+)-14,15-Dehydrovincamine significantly ameliorated mitochondrial dysfunction and maintained mitochondrial homeostasis in a cisplatin-induced AKI model. Furthermore, (+)-14,15-Dehydrovincamine ameliorates cytochrome C-dependent apoptosis in renal tubular epithelial cells. c-Jun NH2-terminal kinase (JNK) was identified as a potential target protein of (+)-14,15-Dehydrovincamine attenuating AKI by network pharmacological analysis. (+)-14,15-Dehydrovincamine inhibited cisplatin-induced JNK activation, mitochondrial fission factor (Mff) phosphorylation, and dynamin-related protein 1 (Drp1) translocation to the mitochondria in renal tubular epithelial cells. Meanwhile, the JNK activator anisomycin restored Mff phosphorylation and Drp1 translocation, counteracting the protective effect of (+)-14,15-Dehydrovincamine on mitochondrial dysfunction in cisplatin-induced TECs injury. In conclusion, (+)-14,15-Dehydrovincamine reduced mitochondrial fission, maintained mitochondrial homeostasis, and attenuated apoptosis by inhibiting the JNK/Mff/Drp1 pathway, which in turn ameliorated cisplatin-induced AKI.

Mitochondrial dynamics in pulmonary disease: Implications for the potential therapeutics

Mitochondria are dynamic organelles that continuously undergo fusion/fission to maintain normal cell physiological activities and energy metabolism. When mitochondrial dynamics is unbalanced, mitochondrial homeostasis is broken, thus damaging mitochondrial function. Accumulating evidence demonstrates that impairment in mitochondrial dynamics leads to lung tissue injury and pulmonary disease progression in a variety of disease models, including inflammatory responses, apoptosis, and barrier breakdown, and that the role of mitochondrial dynamics varies among pulmonary diseases. These findings suggest that modulation of mitochondrial dynamics may be considered as a valid therapeutic strategy in pulmonary diseases. In this review, we discuss the current evidence on the role of mitochondrial dynamics in pulmonary diseases, with a particular focus on its underlying mechanisms in the development of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), asthma, pulmonary fibrosis (PF), pulmonary arterial hypertension (PAH), lung cancer and bronchopulmonary dysplasia (BPD), and outline effective drugs targeting mitochondrial dynamics-related proteins, highlighting the great potential of targeting mitochondrial dynamics in the treatment of pulmonary disease.

Renal denervation ameliorates atrial remodeling in type 2 diabetic rats by regulating mitochondrial dynamics

There is no effective treatment for diabetes-related atrial remodeling currently. This study aimed to investigate the effects of renal denervation (RDN) on diabetes-related atrial remodeling and explore the related mechanisms. A type 2 diabetes mellitus model was established by high-fat diet feeding and low-dose streptozotocin injection in Sprague‒Dawley rats. After successful modeling, the diabetic rats were randomly assigned to two groups according to whether they were subjected to RDN or sham RDN surgery. At the end of the experiment, cardiac function and structure were evaluated by echocardiography and histology, respectively. Mitochondrial morphology, function and mitochondrial dynamics were assessed by multiple methods. Mdivi1 was used to verify the mechanism by which RDN improves atrial remodeling. In the 10th week, diabetic rats exhibited obvious atrial remodeling, including atrial enlargement and diastolic dysfunction. Pathological staining showed that diabetic rats had cardiomyocyte hypertrophy and interstitial fibrosis in atrial tissues. In terms of mitochondrial morphology and function, diabetic rats exhibited fragmented mitochondria, reduced adenosine triphosphate production and decreased mitochondrial membrane potential levels. Abnormal mitochondrial dynamics in diabetic rats were characterized by the inhibition of mitochondrial fusion, excessive mitochondrial fission, and the suppression of mitophagy. However, RDN effectively ameliorated diabetes-induced pathological atrial remodeling. In addition, RDN significantly improved mitochondrial morphological and functional abnormalities and corrected the disorders of mitochondrial dynamics. Furthermore, the protective effects of RDN against atrial remodeling were related to the regulation of mitochondrial dynamics. RDN prevented diabetes-induced atrial remodeling. These protective effects might be related to improvements in mitochondrial dynamics.

Endothelial Birc3 promotes renal fibrosis through modulating Drp1-mediated mitochondrial fission via MAPK/PI3K/Akt pathway

Renal fibrosis serves as the shared pathway in chronic kidney disease (CKD) progression towards end-stage renal disease (ESRD). Endothelial-mesenchymal transition (EndMT) is a vital mechanism leading to the generation of myofibroblasts, thereby contributing to the advancement of fibrogenesis. Baculoviral IAP Repeat Containing 3(Birc3) was identified as a crucial inhibitor of cell death and a significant mediator in inflammatory signaling and immunity. However, its involvement in the development of renal interstitial fibrosis via EndMT still needs to be clarified. Herein, elevated levels of Birc3 expression along with EndMT-associated alterations, including increased α-smooth muscle actin (α-SMA) levels and decreased CD31 expression, were observed in fibrotic kidneys of Unilateral Ureteral Obstruction (UUO)-induced mouse models and transforming growth factor-β (TGF-β)-induced EndMT in Human Umbilical Vein Endothelial Cells (HUVECs). Functionally, Birc3 knockdown inhibited EndMT and mitochondrial fission mediated by dynamin-related protein 1 (Drp1) both in vivo and in vitro. Mechanistically, endothelial Birc3 exacerbated Drp-1-induced mitochondrial fission through the MAPK/PI3K/Akt signaling pathway in endothelial cell models stimulated TGF-β. Collectively, these findings illuminate the mechanisms and indicate that targeting Birc3 could offer a promising therapeutic strategy to improve endothelial cell survival and mitigate the progression of CKD.

F-actin/DRP1 axis-mediated mitochondrial fission promotes mitophagy in diabetic submandibular glands

BACKGROUND

Diabetes is accompanied by a high prevalence of hyposalivation, causing severe damage to oral and systemic health. Mitochondrial dynamics play important roles in the pathogenesis of various diabetic complications; however, little is known about their roles in diabetic hyposalivation.

MATERIALS AND METHODS

A diabetic mouse model and a high glucose (HG)-induced diabetic submandibular gland (SMG) cell model were employed.

RESULTS

More mitochondria surrounded by autophagosomes and higher expression of mitophagy-related proteins were detected in the SMGs of diabetic mice and HG-treated SMG cells. In diabetic SMGs, dynamin-related protein 1 (DRP1) was upregulated, whereas mitofusin-2 was downregulated both in vivo and in vitro. Shortened mitochondria and impaired mitochondrial functions were observed in the HG group. A DRP1-specific inhibitor, mdivi-1, suppressed mitochondrial fission and mitophagy, as well as restored mitochondrial functions in the HG condition. Moreover, the interaction of F-actin and DRP1 was enhanced in the diabetic group. Inhibiting F-actin with cytochalasin D repaired the injured effects of HG on mitochondrial dynamics and functions. Conversely, the F-actin-polymerization-inducer jasplakinolide aggravated mitochondrial fission and dysfunction.

CONCLUSIONS

F-actin contributes to HG-evoked mitochondrial fission by interacting with DRP1, which induces mitophagy and impairs mitochondrial function in SMG cells, ultimately damaging the SMG.

Exendin-4 exhibits cardioprotective effects against high glucose-induced mitochondrial abnormalities: Potential role of GLP-1 receptor and mTOR signaling

Mitochondrial dysfunction is associated with hyperglycemic conditions and insulin resistance leading to cellular damage and apoptosis of cardiomyocytes in diabetic cardiomyopathy. The dysregulation of glucagon-like peptide-1 (GLP-1) receptor and mammalian target of rapamycin (mTOR) is linked to cardiomyopathies and myocardial dysfunctions mediated by hyperglycemia. However, the involvements of mTOR for GLP-1 receptor-mediated cardioprotection against high glucose (HG)-induced mitochondrial disturbances are not clearly identified. The present study demonstrated that HG-induced cellular stress and mitochondrial damage resulted in impaired ATP production and oxidative defense markers such as catalase and SOD2, along with a reduction in survival markers such as Bcl-2 and p-Akt, while an increased expression of pro-apoptotic marker Bax was observed in H9c2 cardiomyoblasts. In addition, the autophagic marker LC3-II was considerably reduced, together with the disruption of autophagy regulators (p-mTOR and p-AMPKα) under the hyperglycemic state. Furthermore, there was a dysregulated expression of several indicators related to mitochondrial homeostasis, including MFN2, p-DRP1, FIS1, MCU, UCP3, and Parkin. Remarkably, treatment with either exendin-4 (GLP-1 receptor agonist) or rapamycin (mTOR inhibitor) significantly inhibited HG-induced mitochondrial damage while co-treatment of exendin-4 and rapamycin completely reversed all mitochondrial abnormalities. Antagonism of GLP-1 receptors using exendin-(9-39) abolished these cardioprotective effects of exendin-4 and rapamycin under HG conditions. In addition, exendin-4 attenuated HG-induced phosphorylation of mTOR, and this inhibitory effect was antagonized by exendin-(9-39), indicating the regulation of mTOR by GLP-1 receptor. Therefore, improvement of mitochondrial dysfunction by stimulating the GLP-1 receptor/AMPK/Akt pathway and inhibiting mTOR signaling could ameliorate cardiac abnormalities caused by hyperglycemic conditions.

PDZD8 Augments Endoplasmic Reticulum-Mitochondria Contact and Regulates Ca2+ Dynamics and Cypd Expression to Induce Pancreatic β-Cell Death during Diabetes

BACKGRUOUND

Diabetes mellitus (DM) is a chronic metabolic disease that poses serious threats to human physical and mental health worldwide. The PDZ domain-containing 8 (PDZD8) protein mediates mitochondria-associated endoplasmic reticulum (ER) membrane (MAM) formation in mammals. We explored the role of PDZD8 in DM and investigated its potential mechanism of action.

METHODS

High-fat diet (HFD)- and streptozotocin-induced mouse DM and palmitic acid (PA)-induced insulin 1 (INS-1) cell models were constructed. PDZD8 expression was detected using immunohistochemistry, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting. MAM formation, interactions between voltage-dependent anion-selective channel 1 (VDAC1) and inositol 1,4,5-triphosphate receptor type 1 (IP3R1), pancreatic β-cell apoptosis and proliferation were detected using transmission electron microscopy (TEM), proximity ligation assay (PLA), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, immunofluorescence staining, and Western blotting. The mitochondrial membrane potential, cell apoptosis, cytotoxicity, and subcellular Ca2+ localization in INS-1 cells were detected using a JC-1 probe, flow cytometry, and an lactate dehydrogenase kit.

RESULTS

PDZD8 expression was up-regulated in the islets of HFD mice and PA-treated pancreatic β-cells. PDZD8 knockdown markedly shortened MAM perimeter, suppressed the expression of MAM-related proteins IP3R1, glucose-regulated protein 75 (GRP75), and VDAC1, inhibited the interaction between VDAC1 and IP3R1, alleviated mitochondrial dysfunction and ER stress, reduced the expression of ER stress-related proteins, and decreased apoptosis while increased proliferation of pancreatic β-cells. Additionally, PDZD8 knockdown alleviated Ca2+ flow into the mitochondria and decreased cyclophilin D (Cypd) expression. Cypd overexpression alleviated the promoting effect of PDZD8 knockdown on the apoptosis of β-cells.

CONCLUSION

PDZD8 knockdown inhibited pancreatic β-cell death in DM by alleviated ER-mitochondria contact and the flow of Ca2+ into the mitochondria.

The overexpression of human amylin in pancreatic β cells facilitate the appearance of amylin aggregates in the kidney contributing to diabetic nephropathy

Diabetic nephropathy is one of the most frequent complications of diabetic patients and is the leading cause of end-stage renal disease worldwide. The complex physiopathology of this complication raises a challenge in the development of effective medical treatments. Therefore, a better understanding of this disease is necessary for producing more targeted therapies. In this work we propose human amylin as a possible mediator in the development of diabetic nephropathy. Islet amyloid polypeptide or amylin is a hormone co-secreted with insulin. The human isoform has the ability to fold and form amyloid aggregates in the pancreas of patients with type 2 diabetes mellitus, disrupting cellular homeostasis due to its ability to form pores in lipid bilayers. It has been described that hIAPP can be secreted and exported in extracellular vesicles outside the pancreas, being a plausible connecting mechanism between the β-cell and other peripheral tissues such as the kidney. Here, we demonstrate that tubular, podocytes and mesangial cells can incorporate hIAPP coming from β-cells. Then, this hIAPP can form aggregates inside these kidney cells, contributing to its failure. In order to study the consequences in vivo, we found amylin aggregates in the kidney of mice overexpressing hIAPP after feeding a high fat diet. In addition, we observed an increase in glomerulosclerosis index and inflammation. Specifically, there were significant changes in signalling pathways directly involved in the diabetic nephropathy such as an increased in mTORC1 signaling pathway, an alteration in mitochondrial dynamics and an increased in endoplasmic reticulum stress. All these results demonstrate the importance of hIAPP in the kidney and its possible contribution in the development of diabetic nephropathy.

AdipoRon Alleviates Liver Injury by Protecting Hepatocytes from Mitochondrial Damage Caused by Ionizing Radiation

Radiation liver injury is a common complication of hepatocellular carcinoma radiotherapy. It is mainly caused by irreversible damage to the DNA of hepatocellular cells directly by radiation, which seriously interferes with metabolism and causes cell death. AdipoRon can maintain lipid metabolism and stabilize blood sugar by activating adiponectin receptor 1 (AdipoR1). However, the role of AdipoRon/AdipoR1 in the regulation of ionizing radiation (IR)-induced mitochondrial damage remains unclear. In this study, we aimed to elucidate the roles of AdipoRon/AdipoR1 in IR-induced mitochondrial damage in normal hepatocyte cells. We found that AdipoRon treatment rescued IR-induced liver damage in mice and mitochondrial damage in normal hepatocytes in vivo and in vitro. AdipoR1 deficiency exacerbated IR-induced oxidative stress, mitochondrial dynamics, and biogenesis disorder. Mechanistically, the absence of AdipoR1 inhibits the activity of adenosine monophosphate-activated protein kinase α (AMPKα), subsequently leading to disrupted mitochondrial dynamics by decreasing mitofusin (MFN) and increasing dynamin-related protein 1 (DRP1) protein expression. It also controls mitochondrial biogenesis by suppressing the peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC1α) and transcription factor A (TFAM) signaling pathway, ultimately resulting in impaired mitochondrial function. To sum up, AdipoRon/AdipoR1 maintain mitochondrial function by regulating mitochondrial dynamics and biogenesis through the AdipoR1-AMPKα signaling pathway. This study reveals the significant role of AdipoR1 in regulating IR-induced mitochondrial damage in hepatocytes and offers a novel approach to protecting against damage caused by IR.

Drp1 Promotes Macrophage M1 Polarization and Inflammatory Response in Autoimmune Myocarditis by Driving Mitochondrial Fission

Autoimmune myocarditis (AM) is characterized by an intricate inflammatory response within the myocardium. Dynamin-related protein 1 (Drp1), a pivotal modulator of mitochondrial fission, plays a role in the pathogenesis of various diseases. A myosin-induced experimental autoimmune myocarditis (EAM) mouse model was successfully established. Flow cytometry was employed to detect M1/M2-like macrophages. Mitochondrial fragmentation was assessed using Mito-Tracker Red CMXRos. Drp1 was upregulated and activated in EAM mice. Depletion of Drp1 was observed to mitigate inflammation, macrophage infiltration and M1 polarization within the cardiac tissue of EAM mice. In M1-like macrophages derived from the hearts of EAM mice, Drp1 was found to promote mitochondrial fission and diminish mitochondrial fusion. Furthermore, the depletion of Drp1 reduced the NF-κB-related pro-inflammatory response in EAM-associated M1-like macrophages. Drp1 drives mitochondrial fission in macrophages, driving their M1 polarization and the subsequent inflammatory response. Drp1 may represent an effective target for the prevention and treatment of AM.

Metabolic regulation of mitochondrial morphologies in pancreatic beta cells: coupling of bioenergetics and mitochondrial dynamics

Cellular bioenergetics and mitochondrial dynamics are crucial for the secretion of insulin by pancreatic beta cells in response to elevated levels of blood glucose. To elucidate the interactions between energy production and mitochondrial fission/fusion dynamics, we combine live-cell mitochondria imaging with biophysical-based modeling and graph-based network analysis. The aim is to determine the mechanism that regulates mitochondrial morphology and balances metabolic demands in pancreatic beta cells. A minimalistic differential equation-based model for beta cells is constructed that includes glycolysis, oxidative phosphorylation, calcium dynamics, and fission/fusion dynamics, with ATP synthase flux and proton leak flux as main regulators of mitochondrial dynamics. The model shows that mitochondrial fission occurs in response to hyperglycemia, starvation, ATP synthase inhibition, uncoupling, and diabetic conditions, in which the rate of proton leakage exceeds the rate of mitochondrial ATP synthesis. Under these metabolic challenges, the propensities of tip-to-tip fusion events simulated from the microscopy images of the mitochondrial networks are lower than those in the control group and prevent the formation of mitochondrial networks. The study provides a quantitative framework that couples bioenergetic regulation with mitochondrial dynamics, offering insights into how mitochondria adapt to metabolic challenges.

Modification in mitochondrial function is associated with the FADS1 variant and its interaction with alpha-linolenic acid-enriched diet-An exploratory study

Fatty acid desaturase (FADS1) variant-rs174550 strongly regulates polyunsaturated fatty acid (PUFA) biosynthesis. Additionally, the FADS1 is related to mitochondrial function. Thus, we investigated whether changes in mitochondrial function are associated with the genetic variation in FADS1 (rs174550) in human adipocytes isolated from individuals consuming diets enriched with either dietary alpha-linolenic (ALA) or linoleic acid (LA). Two cohorts of men homozygous for the genotype of FADS1 (rs174550) were studied: FADSDIET2 dietary intervention study with ALA- and LA-enriched diets and Kuopio Obesity Surgery study (KOBS), respectively. We could demonstrate that differentiated human adipose-derived stromal cells from subjects with the TT genotype had higher mitochondrial metabolism compared with subjects with the CC genotype of FADS1-rs174550 in the FADSDIET2. Responses to PUFA-enriched diets differed between the genotypes of FADS1-rs174550, showing that ALA, but not LA, -enriched diet stimulated mitochondrial metabolism more in subjects with the CC genotype when compared with subjects with the TT genotype. ALA, but not LA, proportion in plasma phospholipid fraction correlated positively with adipose tissue mitochondrial-DNA amount in subjects with the CC genotype of FADS1-rs174550 in the KOBS. These findings demonstrate that the FADS1-rs174550 is associated with modification in mitochondrial function in human adipocytes. Additionally, subjects with the CC genotype, when compared with the TT genotype, benefit more from the ALA-enriched diet, leading to enhanced energy metabolism in human adipocytes. Altogether, the FADS1-rs174550 could be a genetic marker to identify subjects who are most suitable to receive dietary PUFA supplementation, establishing also a personalized therapeutic strategy to improve mitochondrial function in metabolic diseases.

The effects of Cannabis sativa and cannabinoids on the inhibition of pancreatic lipase - An enzyme involved in obesity

INTRODUCTION

Obesity is a chronic noncommunicable disease characterized by excessive body fat that can have negative health consequences. Obesity is a complex disease caused by a combination of genetic, environmental, and lifestyle factors. It is characterized by a discrepancy between caloric intake and expenditure. Obesity increases the risk of acquiring major chronic diseases, including heart disease, stroke, cancer, and Type 2 diabetes mellitus (T2DM). Currently, the inhibition of pancreatic lipases (PL) is a promising pharmacological therapy for obesity and weight management. In this study, the inhibition of pancreatic lipase by Cannabis sativa (C. sativa) plant extract and cannabinoids was investigated.

METHODS

The inhibitory effect was assessed using p-nitrophenyl butyrate (pNPB), and the results were obtained by calculating the percentage relative activity and assessed using one-way analysis of variance (ANOVA). Kinetic studies and spectroscopy techniques were used to evaluate the mode of inhibition. Diet-induced; and diabetic rat models were studied to evaluate the direct effects of C. sativa extract on PL activity.

RESULTS

Kinetic analyses showed that the plant extracts inhibited pancreatic lipase, with tetrahydrocannabinol (THC) and cannabinol (CBN) being the potential cause of the inhibition noted for the C. sativa plant extract. CBN and THC inhibited the pancreatic lipase activity in a competitive manner, with the lowest residual enzyme activity of 52 % observed at a 10 μg/mL concentration of CBN and 39 % inhibition at a 25 μg/mL concentration of THC. Circular dichroism (CD) spectroscopy revealed that the inhibitors caused a change in the enzyme's secondary structure. At low concentrations, THC showed potential for synergistic inhibition with orlistat. C.sativa treatment in an in vivo rat model confirmed its inhibitory effects on pancreatic lipase activity.

CONCLUSION

The findings in this study provided insight into the use of cannabinoids as pancreatic lipase inhibitors and the possibility of using these compounds to develop new pharmacological treatments for obesity.

GRP78 mediates mitochondrial fusion and fission in cigarette smoke-induced inflammatory responses in airway epithelial cells

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is characterized by persistent airway inflammation, with cigarette smoke being a major contributor to epithelial injury. Recent studies have shown that abnormal mitochondrial function is closely linked to the onset and progression of airway inflammation. This study aims to explore the role and underlying molecular mechanisms of mitochondrial dynamics in cigarette smoke-induced airway inflammation.

MATERIALS AND METHODS

Human bronchial epithelial (HBE) cells were exposed to cigarette smoke extract (CSE) to assess the expression of mitochondrial fusion markers MFN2 and OPA1, the fission marker DRP1, and the glucose-regulated protein GRP78. The siRNA and pharmaceutics targeting DRP1, MFN2, and GRP78 were employed. Both cells and supernatants were analyzed for inflammatory factor levels and the related signaling pathways.

RESULTS

In this study, HBE cells exposed to CSE showed a significant decrease in the proteins MFN2 and OPA1 and an increase in DRP1. The inhibition of DRP1 expression mitigated inflammation while silencing MFN2 exacerbated it. This was similarly corroborated by the use of the DRP1 inhibitor mdivi-1 and the MFN2 activator leflunomide. Additionally, we proved that GRP78 played an important regulatory role as an essential endoplasmic reticulum protein, regulating the mitochondrial fusion/fission process and subsequently activating the NF-κB pathway to regulate airway inflammation.

DISCUSSION AND CONCLUSION

Taken together, these results suggested that the GRP78-mediated mitochondrial fusion and fission process played a vital role in cigarette smoke-induced airway inflammation and might be a potential therapeutic target in this regard.

Nimbolide protects against diabetic cardiomyopathy by regulating endoplasmic reticulum stress and mitochondrial function via the Akt/mTOR pathway

Nimbolide has been demonstrated to possess protective properties against gestational diabetes mellitus and diabetic retinopathy. However, the role and molecular mechanism of nimbolide in diabetic cardiomyopathy (DCM) remain unknown. Diabetes was induced in rats via a single injection of streptozotocin (STZ) and then the diabetic rats were administered nimbolide (5 mg/kg and 20 mg/kg) or dimethyl sulfoxide daily for 12 weeks. H9c2 cardiomyocytes were exposed to high glucose (25 mM glucose) to mimic DCM in vitro. The protective effects of nimbolide against DCM were evaluated in vivo and in vitro. The potential molecular mechanism of nimbolide in DCM was further explored. We found that nimbolide dose-dependently decreased blood glucose and improved body weight of diabetic rats. Additionally, nimbolide dose-dependently improved cardiac function, alleviated myocardial injury/fibrosis, and inhibited endoplasmic reticulum (ER) stress and apoptosis in diabetic rats. Moreover, nimbolide dose-dependently improved mitochondrial function and activated the Akt/mTOR signaling. We consistently demonstrated the cardioprotective effects of nimbolide in an in vitro model of DCM. The involvement of ER stress and mitochondrial pathways were further confirmed by using inhibitors of ER stress and mitochondrial division. By applying a specific Akt inhibitor SC66, the cardioprotective effects of nimbolide were partially blocked. Our study indicated that nimbolide alleviated DCM by activating Akt/mTOR pathway. Nimbolide may be a novel therapeutic agent for DCM treatment.

Temporal Dynamics of Oxidative Stress and Inflammation in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is the most common lung complication of prematurity. Despite extensive research, our understanding of its pathophysiology remains limited, as reflected by the stable prevalence of BPD. Prematurity is the primary risk factor for BPD, with oxidative stress (OS) and inflammation playing significant roles and being closely linked to premature birth. Understanding the interplay and temporal relationship between OS and inflammation is crucial for developing new treatments for BPD. Animal studies suggest that OS and inflammation can exacerbate each other. Clinical trials focusing solely on antioxidants or anti-inflammatory therapies have been unsuccessful. In contrast, vitamin A and caffeine, with antioxidant and anti-inflammatory properties, have shown some efficacy, reducing BPD by about 10%. However, more than one-third of very preterm infants still suffer from BPD. New therapeutic agents are needed. A novel tripeptide, N-acetyl-lysyltyrosylcysteine amide (KYC), is a reversible myeloperoxidase inhibitor and a systems pharmacology agent. It reduces BPD severity by inhibiting MPO, enhancing antioxidative proteins, and alleviating endoplasmic reticulum stress and cellular senescence in a hyperoxia rat model. KYC represents a promising new approach to BPD treatment.

Radioactive Iodine-131 Therapy Reduced the Risk of MACEs and All-Cause Mortality in Elderly with Hyperthyroidism Combined with Type 2 Diabetes

Aim

This study aimed to assess the efficacy of antithyroid drugs (ATDs) and radioactive iodine-131 (RAI) therapies in reducing the risk of major adverse cardiovascular events (MACEs) and all-cause mortality in patients with hyperthyroidism complicated with type 2 diabetes mellitus (T2DM).

Methods

Between January 2013 and December 2021, 540 subjects were included in the analysis. All participants were followed up for 9 years, with a median of 54 months (2451 person-years). The subjects were categorized into two groups: the ATDs group (n = 414) and the RAI group (n = 126). According to the free triiodothyronine (FT3) tertiles, the patients receiving RAI were further grouped as follows: low-level (≤ 4.70 pmol/L, n = 42), moderate-level (4.70-12.98 pmol/L, n = 42), and high-level (≥ 12.98 pmol/L, n = 42). The efficacy of ATDs and RAI therapies in reducing the risk of MACEs and all-cause mortality was assessed.

Results

Of the 540 participants, 163 experienced MACEs (30.19%), 25 (15.34%) of whom died. Multivariate Cox regression analyses revealed that RAI was associated with a 38.5% lower risk of MACEs (P = 0.016) and a 77.1% lower risk of all-cause mortality (P = 0.046). Stratified analyses indicated that RAI had a protective effect on MACEs in patients aged ≥ 60 years (P = 0.001, P for interaction = 0.031) and patients with a duration of diabetes mellitus ≥ 6 years (P = 0.013, P for interaction = 0.002). Kaplan‒Meier analysis revealed a lower cumulative incidence of MACEs and all-cause mortality in the RAI group (log-rank, all P < 0.05). Moreover, the ROC curve suggested an optimal FT3 cut-off value of 5.4 pmol/mL for MACE (P < 0.001).

Conclusion

Our findings suggested that RAI therapy effectively reduced the risk of MACEs and all-cause mortality in elderly patients with hyperthyroidism combined with T2DM.