Mitochondrial dysfunction in diabetes: from molecular mechanisms to functional significance and therapeutic opportunities

Impairment of platelet mitochondrial respiration in patients with chronic kidney disease with and without diabetes

Chronic kidney disease (CKD) and diabetic kidney disease (DKD) are major public health problems, and their burden is growing relentlessly with the aging of the global population. Their early recognition is now a public health priority, and there is an unmet need for the identification of specific biomarkers in minimally invasive or non-invasive samples. Mitochondrial dysfunction plays a pivotal role in the development and progression of both CKD and DKD and circulating platelets have emerged as an ideal candidate for the assessment of the respiratory function. The present study assessed mitochondrial respiration in platelets isolated from the peripheral blood of patients with DKD and CKD compared to healthy controls. The study included a total number of 89 subjects, as follows: 30 DKD patients divided into three subgroups based on the urinary albumin-to-creatinine ratio (uACR): 20 normoalbuminuric, 10 microalbuminuric, and 10 macroalbuminuric, 29 CKD patients (positive controls) and 20 healthy individuals (negative controls). Platelets were isolated by differential centrifugations and a high-resolution respirometry protocol was adapted to assess mitochondrial respiration dependent on complex I (CI) and complex II (CII). A significant reduction of the CI-supported active respiration was found in the normoalbuminuric DKD patients and further decreased in the microalbuminuric DKD subgroup. Both CI and CII-dependent coupled respiration and the maximal uncoupled respiration were significantly reduced in the macroalbuminuric DKD subgroup. In conclusion, mitochondrial respiration impairment in peripheral platelets is evident from the early stages of DKD. Moreover, platelet mitochondrial respiration was more severely impaired in patients with macroalbuminuric DKD as compared to those with CKD. Further, more extensive follow-up studies are warranted to determine whether platelet respiratory mitochondrial dysfunction could serve as a peripheral biomarker for kidney mitochondrial dysfunction and/or as a prognostic tool in DKD.

Sphenocentrum jollyanum (Pierre) aqueous leaf extract demonstrates anti-inflammatory and mitochondrial-restorative influences while modulating apoptosis in streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Sphenocentrum jollyanum (Pierre) is a medicinal plant native to West African countries, especially Nigeria and Ghana. The leaf of S. jollyanum is a traditional therapy for diabetes, erectile dysfunction, gastrointestinal disorders, and malaria. However, there is a paucity of information on the mitochondrial-restorative and apoptotic-modulating properties of S. jollyanum leaf.

AIM OF THE STUDY

The anti-inflammatory, apoptotic-modulating, and mitochondrial-restorative effects of S. jollyanum were studied using diabetic Wistar albino rats induced with streptozotocin.

METHODS

A high-fat diet (HFD) and a single dose injection of 10 mg/kg of streptozotocin (STZ) were used to induce type-2 diabetes model. Thirty-six (36) rats were randomly assigned into six groups as follows: Group 1 (normal diet + normal saline), Group 2 (HFD + 50 mg/kg STZ), Group 3 (HFD + 50 mg/kg STZ + 10 mg/kg glibenclamide), Group 4 (HFD + 50 mg/kg STZ + 50 mg/kg of S. jollyanum extract), Group 5 (HFD + 50 mg/kg STZ + 100 mg/kg of S. jollyanum extract), Group 6 (HFD + 50 mg/kg STZ + 200 mg/kg of S. jollyanum extract). Glucose levels (fasting) were monitored in the rats at a 48-h interval. After experimental treatment for 28 days, blood was collected via cardiac puncture into plain bottles. After differential centrifugation, serum was extracted into plain bottles for assessment of insulin, caspases 3 and 9 activity, as well as IL-1β, IL-6, CRP, and TNF-α levels. Liver mitochondria were isolated for mitochondrial ATPase activity, lipid peroxidation and mitochondrial permeability while liver and pancreatic tissues were prepared for histopathology using standard laboratory procedures.

RESULTS

Induction of the Wistar rats with 50 mg/kg of streptozotocin increased fasting glucose, caspase 3, caspase 9, IL-1β, IL-6, TNF-α, CRP, troponin I, as well as increased mitochondrial permeability, mitochondrial lipid peroxidation, and mitochondrial ATPase activity significantly compared to the normoglycemic group and glibenclamide-treated group. This was also accompanied by pathological lesions in the liver and pancreas. Administration of S. jollyanum aqueous leaf extract significantly decreased mitochondrial ATPase activity, mitochondrial lipid peroxidation, caspase 3 and caspase 9 activity, and mitochondrial permeability, fasting blood glucose, IL-1β, IL-6, TNF-α, CRP, and troponin I levels in the diabetic rats, while significantly boosting serum insulin content (p < 0.0001).

CONCLUSION

S. jollyanum aqueous leaf demonstrates anti-inflammatory, mitochondrial-protective and apoptotic-modulating influences while reversing hepatic and pancreatic damage in diabetic Wistar rats.

Miro1- a key player in β-cell function and mitochondrial dynamics under diabetes mellitus

Mitochondrial health is crucial for the survival and function of β-cells, preserving glucose homeostasis and effective insulin production. Miro1, a mitochondrial Rho GTPase1 protein, plays an essential role in maintaining thequality of mitochondria by regulating calcium homeostasis and mitophagy. In this review, we aim to explore the dysfunction of Miro1 in type 2 diabetes mellitus (T2DM) and its contribution to impaired Ca2+ signaling, which increases oxidative stress in β-cells. This dysfunction is the hallmark of T2DM pathogenesis, leading to insufficient insulin production and poor glycemic control. Additionally, we discuss the role of Miro1 in modulating insulin secretion and inflammation, highlighting its effect on modulating key signaling cascades in β-cells. Altogether, enhancing Miro1 function and activity could alleviate mitochondrial dysfunction, reducing oxidative stress-mediated damage, and improving pancreatic β-cell survival. Targeting Miro1 with small molecules or gene-editing approaches could provide effective strategies for restoring cell function and insulin secretion in diabetic individuals. Exploring the deeper knowledge of Miro1 functions and interactions could lead to novel therapeutic advances in T2DM management.

Improvement of Glucose Metabolism by Pennogenin 3-O-β-Chacotrioside via Activation of IRS/PI3K/Akt Signaling and Mitochondrial Respiration in Insulin-Resistant Hepatocytes

SCOPE

Insulin resistance (IR), which causes chronic hyperglycemia, has been one of the most prevalent components of metabolic syndrome over the centuries. Pennogenin 3-O-β-chacotrioside (P3C), the main steroid glycoside derived from Paris polyphylla, has been found to exert various biological activities. However, the exact role of P3C on glucose metabolism in the IR state remains unexplored.

METHODS AND RESULTS

To induce IR, AML12 cells were exposed to glucose (27 mM) and insulin (10 µg/mL) and then incubated with P3C (0.25 or 0.5 µM) for 24 h. The effects of P3C on glucose metabolism in insulin-resistant AML12 cells were evaluated through glucose consumption assays, real-time quantitative polymerase chain reaction (qPCR), Western blotting, and metabolic analysis for extracellular acidification rate (ECAR) and oxygen consumption rate (OCR). Our data showed that P3C significantly improved insulin sensitivity in AML12 hepatocytes with high glucose-induced IR. P3C stimulated insulin sensitivity and glucose uptake by activating the IRS/PI3K/Akt signaling pathway, which enhances glycogen synthesis and suppresses gluconeogenesis in insulin-resistant AML12 cells. In addition, P3C treatment increased the protein expression of p-AMPK and PGC1α, as well as the expression of oxidative phosphorylation complex proteins, potentially enhancing mitochondrial oxidative respiration.

CONCLUSIONS

Our findings imply that P3C could be a therapeutic option for improving metabolic abnormalities associated with IR.

A non-hydrolysable peptidomimetic for mitochondrial targeting

Peptidomimetics, molecules that mimic the activity of natural peptides with improved stability or bioavailability, have emerged as interesting materials with applications in biomedicine. In this study, we describe a hybrid γ,γ-peptidomimetic that efficiently aims at mitochondria, a key therapeutic target associated with several disorders, in living cells. Peptide backbones with a component of cationic and hydrophobic amino acids have been shown to preferentially target mitochondria due to their high negative membrane potential and hydrophobic character of the membranous invaginations of these key organelles. We here exploit the advantageous bioorthogonal properties of a peptidomimetic scaffold that consists of an alternation of (1S,3R)-3-amino-2,2-dimethylcyclobutane-1-carboxylic acid and an Nα-functionalised cis-γ-amino-L-proline derivative. This peptidomimetic exhibited excellent membrane translocation efficiency, mitochondrial targeting ability, and biocompatibility. Mitochondrial targeting was confirmed to be dependent on the electrochemical potential generated by the electron transport chain. The presence of non-natural amino acids rendered the compound exceptionally stable in the presence of proteases, maintaining its integrity and functionality for targeting the organelle even after 1 week of incubation in serum. This stability, coupled with its targeting abilities and the low cytosolic/endosomal residual signal, facilitated the tracking of relevant mitochondrial dynamics, including fission events and intracellular movement. Additionally, this peptidomimetic scaffold allowed the sustained and precise mitochondrial targeting of a pH sensitive ratiometric probe, 5(6)-carboxy-SNARF-1, which enabled mitochondrial pH monitoring. In summary, our study introduces a biomimetic peptide with exceptional mitochondria-targeting properties, ensuring stability in biological media and offering insights into crucial mitochondrial processes.

Mitochondrial DNA variants in the pathogenesis and metabolic alterations of diabetes mellitus

Mitochondrial DNA (mtDNA) variants considerably affect diabetes mellitus by disturbing mitochondrial function, energy metabolism, oxidative stress response, and even insulin secretion. The m.3243 A > G variants is associated with maternally inherited diabetes and deafness (MIDD), where early onset diabetes and hearing loss are prominent features. Other types of mtDNA variants involve genes ND4 and tRNA Ala genes that increase susceptibility to type 2 diabetes. Understanding these variants will provide a basis for developing targeted therapy to improve mitochondrial function and metabolic health. This article reviews the impact of mtDNA variants in diabetes, specifically with regards to the m.3243 A > G variant effects on mitochondrial function and insulin secretion and other mtDNA variants that contribute to diabetes susceptibility, particularly ND4 and tRNA Ala gene variants. Data from extant literature were synthesised to obtain an understanding of how mtDNA variants affect diabetes pathogenesis. The main defect for MIDD is the m.3243 A > G variant, which comprises enhanced susceptibility to metabolic syndrome and type 2 diabetes, followed by mitochondrial dysfunction, insulin resistance, and beta-cell dysfunction. Other mtDNA variants have also been reported to enhance diabetes susceptibility through mitochondrial dysfunction and insulin resistance. Increased production of reactive oxygen species (ROS) resulting from mitochondrial malfunction adds to metabolic and tissue damage. This happens in tissues crucial to glucose homeostasis, and it represents an important contribution of mitochondrial dysfunction to metabolic disturbances in diabetes. These mechanisms would underlie the rationale for developing targeted therapies to preserve mitochondrial function and, hence improve the metabolic health of diabetic patients.

Energy metabolism in health and diseases

Energy metabolism is indispensable for sustaining physiological functions in living organisms and assumes a pivotal role across physiological and pathological conditions. This review provides an extensive overview of advancements in energy metabolism research, elucidating critical pathways such as glycolysis, oxidative phosphorylation, fatty acid metabolism, and amino acid metabolism, along with their intricate regulatory mechanisms. The homeostatic balance of these processes is crucial; however, in pathological states such as neurodegenerative diseases, autoimmune disorders, and cancer, extensive metabolic reprogramming occurs, resulting in impaired glucose metabolism and mitochondrial dysfunction, which accelerate disease progression. Recent investigations into key regulatory pathways, including mechanistic target of rapamycin, sirtuins, and adenosine monophosphate-activated protein kinase, have considerably deepened our understanding of metabolic dysregulation and opened new avenues for therapeutic innovation. Emerging technologies, such as fluorescent probes, nano-biomaterials, and metabolomic analyses, promise substantial improvements in diagnostic precision. This review critically examines recent advancements and ongoing challenges in metabolism research, emphasizing its potential for precision diagnostics and personalized therapeutic interventions. Future studies should prioritize unraveling the regulatory mechanisms of energy metabolism and the dynamics of intercellular energy interactions. Integrating cutting-edge gene-editing technologies and multi-omics approaches, the development of multi-target pharmaceuticals in synergy with existing therapies such as immunotherapy and dietary interventions could enhance therapeutic efficacy. Personalized metabolic analysis is indispensable for crafting tailored treatment protocols, ultimately providing more accurate medical solutions for patients. This review aims to deepen the understanding and improve the application of energy metabolism to drive innovative diagnostic and therapeutic strategies.

Mitochondrial glutamic-oxaloacetic transaminase (GOT2) in the growth of C2C12 myoblasts

Glutamine is well recognized as critical to the growth of most cell types. Within mitochondria glutamine is converted to glutamate by glutaminase. Oxaloacetate and glutamate then react to form alpha-ketoglutarate (α-KG) and aspartate catalyzed by glutamic-oxaloacetic transaminase (GOT2) or directly converted to α-KG by glutamate dehydrogenase (GDH). We investigated the role of GOT2 in mediating glutamate metabolism and cell growth in undifferentiated C2C12 cells. CRISPR mediated GOT2 knockout (KO) impaired cell growth, partially overcome by higher concentrations of glutamine. Mitochondrial respiration did not differ between KO and wildtype (WT) cells. Metabolite profiling showed that GOT2KO decreased aspartate by about 50% in KO versus WT cells. In contrast, α-KG increased. Metabolites reflecting the pentose phosphate pathway were significantly increased in KO cells. Metabolic pathway analyses revealed alteration of the TCA cycle, the pentose phosphate pathway, and amino acid metabolism. Glutamine 13C-tracing revealed decreased generation of aspartate, increased ribulose phosphate and evidence for reductive carboxylation of α-KG to isocitrate in KO cells. GDH expression was detected in C2C12 cells but did not differ between WT and GOT2KO mitochondria. GDH is not or barely expressed in adult muscle, however, we observed clear expression in pre-weanling mice. Cytosolic glutamic-oxaloacetic transaminase, GOT1, expression did not differ between GOT2KO and WT cells. In summary, GOT2 is necessary for glutamate flux and generation of downstream metabolites needed for the growth of C2C12 myoblasts. Although respiration did not differ, lack of aspartate and other compounds needed for cell proliferation may have been major factors impairing growth.

Restoration of mitochondrial function alleviates trigeminal neuropathic pain in mice

Craniofacial pain is prevalent and a debilitating condition. Managing craniofacial pain is particularly challenging due to its multifaceted nature. Among the most severe forms of craniofacial pain is trigeminal neuralgia, often described as one of the most excruciating pain syndromes encountered in clinical practice. Utilizing a mouse model of trigeminal neuropathic pain, we found severe mitochondrial impairment in the injured trigeminal ganglion (TG), spanning transcription and translation to functionality. Our findings demonstrated that rejuvenating mitochondria by boosting NAD+ levels enhanced mitochondrial fitness and significantly ameliorated trigeminal neuropathic pain. Additionally, we showed that the analgesic effects of nicotinamide riboside (NR) supplementation mainly depend on Sirt1. Importantly, our multi-omics studies revealed that activated Sirt1 by NR suppresses a broad range of key pain genes and exerts anti-inflammatory effects in the TG. Together, we present a comprehensive view of how mitochondrial dysfunction is involved in trigeminal neuropathic pain. Therefore, targeting mitochondrial dysfunction offers a novel and promising approach to craniofacial pain management.

Effects of Exercise Training on Cardiac Mitochondrial Functions in Diabetic Heart: A Systematic Review

A diabetic heart is characterized by fibrosis, autophagy, oxidative stress, and altered mitochondrial functions. For this review, three databases (PubMed, EMBASE, and Web of Science) were searched for articles written in English from September 2023 to April 2024. Studies that used exercise training for at least 3 weeks and which reported positive, negative, or no effects were included. The CAMARADES checklist was used to assess the quality of the included studies, and ten studies (CAMARADES scores 4-7/10) were included. Nine studies showed that exercise training improved cardiac mitochondrial oxidative phosphorylation by decreasing ROS, increasing electron transport chain activity, and enhancing the production of ATP. Eight studies indicated that exercise training ameliorated mitochondrial biogenesis by increasing the levels of AMPK, PGC-1α, Akt, Irisin, and Sirtuin-III. Moreover, four studies focused on mitochondrial dynamics and concluded that exercise training helped decrease the levels of mitochondrial fission factor and dynamin-related protein- 1. Finally, six studies revealed improvements in mitochondrial physiological characteristics such as size, potential, and permeability. Our findings demonstrate the beneficial effects of exercise training on cardiac mitochondrial function in diabetic hearts. Exercise training improves cardiac mitochondrial physiological characteristics, oxidative phosphorylation, biogenesis, and dynamics.

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.

Structure based exploration of mitochondrial alpha carbonic anhydrase inhibitors as potential leads for anti-obesity drug development

BACKGROUND

Obesity has emerged as a major health challenge globally in the last two decades. Dysregulated fatty acid metabolism and de novo lipogenesis are prime causes for obesity development which ultimately trigger other co-morbid pathological conditions thereby risking life longevity. Fatty acid metabolism and de novo lipogenesis involve several biochemical steps both in cytosol and mitochondria. Reportedly, the high catalytically active mitochondrial carbonic anhydrases (CAVA/CAVB) regulate the intercellular depot of bicarbonate ions and catalyze the rapid carboxylation of pyruvate and acetyl-co-A to acetyl-co-A and malonate respectively, which are the precursors of fatty acid synthesis and lipogenesis. Several in vitro and in vivo investigations indicate inhibition of mitochondrial carbonic anhydrase isoforms interfere in the functioning of pyruvate, fatty acid and succinate pathways. Targeting of mitochondrial carbonic anhydrase isoforms (CAVA/CAVB) could thereby modulate gluconeogenetic as well as lipogenetic pathways and pave way for designing of novel leads in the development pipeline of anti-obesity medications.

METHODS

The present review unveils a diverse chemical space including synthetic sulphonamides, sulphamates, sulfamides and many natural bioactive molecules which selectively inhibit the mitochondrial isoform CAVA/CAVB with an emphasis on major state-of-art drug design strategies.

RESULTS

More than 60% similarity in the structural framework of the carbonic anhydrase isoforms has converged the drug design methods towards the development of isoform selective chemotypes. While the benzene sulphonamide derivatives selectively inhibit CAVA/CAVB in low nanomolar ranges depending on the substitutions on the phenyl ring, the sulpamates and sulpamides potently inhibit CAVB. The virtual screening and drug repurposing methods have also explored many non-sulphonamide chemical scaffolds which can potently inhibit CAVA.

CONCLUSION

The review could pave way for the development of novel and effective anti-obesity drugs which can modulate the energy metabolism.

Sarcopenia: recent advances for detection, progression, and metabolic alterations along with therapeutic targets

Sarcopenia, a disorder marked by muscle loss and dysfunction, is a global health concern, particularly in aging populations. Sarcopenia is intricately related to various health conditions, including obesity, dysphagia, and frailty, which underscores the complexity. Despite recent advances in metabolomics and other omics data for early detection and treatment, the precise characterization and diagnosis of sarcopenia remains challenging. In the present review we provide an overview of the complex metabolic mechanisms that underlie sarcopenia, with particular emphasis on protein, lipid, carbohydrate, and bone metabolism. The review highlights the importance of leucine and other amino acids in promoting muscle protein synthesis and clarifies the critical role played by amino acid metabolism in preserving muscular health. In addition, the review provides insights regarding lipid metabolism on sarcopenia, with an emphasis on the effects of inflammation and insulin resistance. The development of sarcopenia is largely influenced by insulin resistance, especially with regard to glucose metabolism. Overall, the review emphasizes the complex relationship between bone and muscle health by highlighting the interaction between sarcopenia and bone metabolism. Furthermore, the review outlines various therapeutic approaches and potential biomarkers for diagnosing sarcopenia. These include pharmacological strategies such as hormone replacement therapy and anabolic steroids as well as lifestyle modifications such as exercise, nutrition, and dietary changes.

Cellular oxygen consumption in patients with diabetic ketoacidosis

BACKGROUND

Diabetic ketoacidosis (DKA) is a potentially life-threatening disorder associated with severe alterations in metabolism and acid-base status. Mitochondrial dysfunction is associated with diabetes and its complications. Thiamine and coenzyme Q10 (CoQ10) are important factors in aerobic metabolism. In this study, we measured cellular oxygen consumption rates (OCRs) and the effects of in vitro administration of thiamine and CoQ10 on OCRs in patients with DKA versus healthy controls.

METHODS

Blood samples were collected from a prospective cohort of patients with DKA and from controls. Cellular OCRs were measured in peripheral blood mononuclear cells (PBMC) without treatment and after treatment with thiamine, CoQ10, or both. The mitochondrial profile was measured using an XFe96 Extracellular Flux Analyzer and XF Cell Mito Stress Test Kit (Seahorse Bioscience). A linear quantile mixed model was used to compare OCRs and estimate treatment effects.

RESULTS

A total of 62 patients with DKA and 48 controls were included in the study. The median basal and maximal OCRs were lower in the DKA group than in the control group (basal: 4.7 [IQR: 3.3, 7.9] vs. 7.9 [5.0, 9.5], p = 0.036; maximal: 16.4 [9.5, 28.1] vs. 31.5 [20.6, 46.0] pmol/min/µg protein, p < 0.001). In DKA samples, basal and maximal OCRs were significantly increased when treated with thiamine, CoQ10, or both. In controls, basal and maximal OCR were significantly increased only with thiamine treatment.

CONCLUSION

Mitochondrial metabolic profiles of patients with DKA demonstrated lower cellular oxygen consumption when compared to healthy controls. Oxygen consumption increased significantly in cells of patients with DKA treated with thiamine or CoQ10. These results suggest that thiamine and CoQ10 could potentially have therapeutic benefits in DKA via their metabolic effects on mitochondrial cellular respiration.

Inhibition of dynamin-related protein 1-filamin interaction improves systemic glucose metabolism

BACKGROUND AND PURPOSE

Maintaining mitochondrial quality is attracting attention as a new strategy to treat diabetes and diabetic complications. We previously reported that mitochondrial hyperfission by forming a protein complex between dynamin-related protein (Drp) 1 and filamin, mediates chronic heart failure and cilnidipine, initially developed as an L/N-type Ca2+ channel blocker, improves heart failure by inhibiting Drp1-filamin protein complex. We investigated whether cilnidipine improves hyperglycaemia of various diabetic mice models.

EXPERIMENTAL APPROACH

Retrospective analysis focusing on haemoglobin A1c (HbA1c) was performed in hypertensive and hyperglycaemic patients taking cilnidipine and amlodipine. After developing diabetic mice by streptozotocin (STZ) treatment, an osmotic pump including drug was implanted intraperitoneally, followed by weekly measurements of blood glucose levels. Mitochondrial morphology was analysed by electron microscopy. A Ca2+ channel-insensitive cilnidipine derivative (1,4-dihydropyridine [DHP]) was synthesized and its pharmacological effect was evaluated using obese (ob/ob) mice fed with high-fat diet (HFD).

KEY RESULTS

In patients, cilnidipine was superior to amlodipine in HbA1c lowering effect. Cilnidipine treatment improved systemic hyperglycaemia and mitochondrial morphological abnormalities in STZ-exposed mice, without lowering blood pressure. Cilnidipine failed to improve hyperglycaemia of ob/ob mice, with suppressing insulin secretion. 1,4-DHP improved hyperglycaemia and mitochondria abnormality in ob/ob mice fed HFD. 1,4-DHP and cilnidipine improved basal oxygen consumption rate of HepG2 cells cultured under 25 mM glucose.

CONCLUSION AND IMPLICATIONS

Inhibition of Drp1-filamin protein complex formation becomes a new strategy for type 2 diabetes treatment.

Inhibition of endoplasmic reticulum stress and excessive autophagy by Jiedu Tongluo Tiaogan Formula via a CaMKKβ/AMPK pathway contributes to protect pancreatic β-cells

ETHNOPHARMACOLOGICAL RELEVANCE

Jiedu Tongluo Tiaogan Formula (JTTF), a traditional Chinese herbal decoction, exhibits the potential to treat type 2 diabetes mellitus (T2DM) by inhibiting endoplasmic reticulum stress (ERS) and excessive autophagy, which are the risk factors for the abnormal development and progression of β cells.

AIM OF THE STUDY

We aimed to assess the effect of JTTF on pancreatic glucotoxicity by inhibiting ERS and excessive autophagy, for which db/db mice and INS-1 insulinoma cells were used.

MATERIALS AND METHODS

The chemical composition of the JTTF was analyzed by UPLC-Q/TOF-MS. Diabetic (db/db) mice were treated with distilled water or JTTF (2.4 and 7.2 g/kg/day) for 8 weeks. Furthermore, INS-1 cells induced by high glucose (HG) levels were treated with or without JTTF (50, 100, and 200 μg/mL) for 48 h to elucidate the protective mechanism of JTTF on glucose toxicity. The experimental methods included an oral glucose tolerance test, hematoxylin-eosin staining, immunohistochemistry, western blotting, RT-qPCR, and acridine orange staining.

RESULT

28 chemical components of JTTF were identified. Additionally, treatment with JTTF significantly decreased the severity of glycemic symptoms in the db/db mice. Moreover, the treatment partially restored glucose homeostasis in the db/db mice and protected the pancreatic β-cell function. JTTF protected INS-1 cells from HG injury by upregulating GSIS and PDX1, MafA mRNA expression. Further, treatment with JTTF downregulated GRP78 and ATF6 expression, whereas it inhibited Beclin-1 and LC3 activation. The treatment protected the cells from HG-induced ERS and excessive autophagy by downregulating the CaMKKβ/AMPK pathway.

CONCLUSIONS

The present study findings show that JTTF may protects β-cells by inhibiting the CaMKKβ/AMPK pathway, which deepens our understanding of the effectiveness of JTTF as a treatment strategy against T2DM.

Mitochondrial DNA copy number and neurocognitive outcomes in children

BACKGROUND

Low mitochondria DNA copy number (mtDNAcn) has been linked to cognitive decline. However, the role of mtDNAcn in healthy cognitive development is unclear. We hypothesized early-life mtDNAcn would be associated with children's learning and memory.

METHODS

We quantified mtDNAcn in umbilical cord blood and child blood at ages 5-7 from participants in a prospective birth cohort. We administered the Children's Memory Scale (CMS) at ages 9-14 (N = 342) and the Wechsler Intelligence Scale for Children (WISC-IV) at ages 7 and 9 (N = 457). Associations between mtDNAcn tertiles and CMS and WISC were evaluated with linear regression and linear mixed-effects models, respectively. We examined non-linear associations using generalized additive mixed models.

RESULTS

Relative to the middle tertile of mtDNAcn, lower childhood mtDNAcn was associated with lower WISC Working Memory (β = -2.65, 95% CI [-5.24, -0.06]) and Full-Scale IQ (β = -3.71 [-6.42, -1.00]), and higher CMS Visual Memory (β = 4.70 [0.47, 8.93]). Higher childhood mtDNAcn was linked to higher CMS Verbal Memory (β = 7.75 [2.50, 13.01]). In non-linear models, higher childhood mtDNAcn was associated with lower WISC Verbal Comprehension.

CONCLUSIONS

Our study provides novel evidence that mtDNAcn measured in childhood is associated with children's neurocognitive performance. mtDNAcn may be a marker of healthy child development.

IMPACT

Mitochondrial DNA copy number (mtDNAcn) may serve as a biomarker for early-life neurocognitive performances in the children's population. Both low and high mtDNAcn may contribute to poorer neurocognition, reflected through learning and memory abilities. This research elucidated the importance of investigating mitochondrial biomarkers in healthy populations and facilitated advancements of future studies to better understand the associations between mitochondrial markers and adverse children's health outcomes.

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.

Skeletal muscle mitochondrial morphology negatively affected in mice lacking Xin

Altered mitochondrial structure and function are implicated in the functional decline of skeletal muscle. Numerous cytoskeletal proteins are known to affect mitochondrial homeostasis, but this complex network is still being unraveled. Here, we investigated mitochondrial alterations in mice lacking the cytoskeletal adapter protein, XIN (XIN-/-). XIN-/- and wild-type littermate male and female mice were fed a chow or high-fat diet (HFD; 60% kcal fat) for 8 weeks before analyses of their skeletal muscles were conducted. Immuno-electron microscopy (EM) and immunofluorescence staining revealed XIN in the mitochondria and peri-mitochondrial areas, as well as the myoplasm. Intermyofibrillar mitochondria in chow-fed XIN-/- mice were notably different from wild-type (large, and/or swollen in appearance). Succinate dehydrogenase and Cytochrome Oxidase IV staining indicated greater evidence of mitochondrial enzyme activity in XIN-/- mice. No difference in body mass gains or glucose handling was observed between cohorts with HFD. However, EM revealed significantly greater mitochondrial density with evident structural abnormalities (swelling, reduced cristae density) in XIN-/- mice. Absolute Complex I and II-supported respiration was not different between groups, but relative to mitochondrial density, was significantly lower in XIN-/-. These results provide the first evidence for a role of XIN in maintaining mitochondrial morphology and function.

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

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

VDAC1-Based Peptides as Potential Modulators of VDAC1 Interactions with Its Partners and as a Therapeutic for Cancer, NASH, and Diabetes

This review presents current knowledge related to the voltage-dependent anion channel-1 (VDAC1) as a multi-functional mitochondrial protein that acts in regulating both cell life and death. The location of VDAC1 at the outer mitochondrial membrane (OMM) allows control of metabolic cross-talk between the mitochondria and the rest of the cell, and also enables its interaction with proteins that are involved in metabolic, cell death, and survival pathways. VDAC1's interactions with over 150 proteins can mediate and regulate the integration of mitochondrial functions with cellular activities. To target these protein-protein interactions, VDAC1-derived peptides have been developed. This review focuses specifically on cell-penetrating VDAC1-based peptides that were developed and used as a "decoy" to compete with VDAC1 for its VDAC1-interacting proteins. These peptides interfere with VDAC1 interactions, for example, with metabolism-associated proteins such as hexokinase (HK), or with anti-apoptotic proteins such as Bcl-2 and Bcl-xL. These and other VDAC1-interacting proteins are highly expressed in many cancers. The VDAC1-based peptides in cells in culture selectively affect cancerous, but not non-cancerous cells, inducing cell death in a variety of cancers, regardless of the cancer origin or genetics. They inhibit cell energy production, eliminate cancer stem cells, and act very rapidly and at low micro-molar concentrations. The activity of these peptides has been validated in several mouse cancer models of glioblastoma, lung, and breast cancers. Their anti-cancer activity involves a multi-pronged attack targeting the hallmarks of cancer. They were also found to be effective in treating non-alcoholic fatty liver disease and diabetes mellitus. Thus, VDAC1-based peptides, by targeting VDAC1-interacting proteins, offer an affordable and innovative new conceptual therapeutic paradigm that can potentially overcome heterogeneity, chemoresistance, and invasive metastatic formation.

Reduction of hyperglycemia in STZ-induced diabetic mice by prophylactic treatment with heat-killed Mycobacterium aurum: possible effects on glucose utilization, mitochondrial uncoupling, and oxidative stress in liver and skeletal muscle

Background

In addition to conventional treatment and modifications in physical activity and diet, alternative strategies have been investigated to manage, prevent, or delay diabetes in humans. In this regard, one strategy has relied on the immunomodulatory properties of mycobacteria, whereby Bacillus Calmette-Guerin, an attenuated live strain of Mycobacterium bovis, has been shown to improve glycemic control in patients with diabetes and to alleviate hyperglycemia in selected murine models of diabetes. A novel heat-killed (HK) whole-cell preparation of Mycobacterium aurum (M. aurum) is currently under development as a potential food supplement; nevertheless, its potential bioactivity remains largely unknown. Thus, the present study investigated the potential prophylactic anti-diabetic effects of HK M. aurum in streptozotocin (STZ)-induced diabetic mice.

Methods

Mice were divided into three groups: the STZ-induced diabetic group was injected with a single intraperitoneal high dose of STZ, the HK M. aurum-treated diabetic group was prophylactically treated with three doses of HK M. aurum 6 weeks before STZ injection, and the control non-diabetic group was given three intradermal injections of borate-buffered saline and an intraperitoneal injection of citrate buffer. Liver lactate dehydrogenase (LDH), uncoupling protein 2 (UCP2), and glucose transporter 2 (GLUT2) and skeletal muscle LDH, UCP3, and GLUT4 protein expression levels in different mouse groups were determined by Western blot.

Results

Our results indicated that HK M. aurum did not cause any significant changes in glycemic levels of normal non-diabetic mice. Prophylactic administration of three doses of HK M. aurum to diabetic mice resulted in a significant reduction in their blood glucose levels when compared to those in control diabetic mice. Prophylactic treatment of diabetic mice with HK M. aurum significantly restored their disturbed protein expression levels of liver UCP2 and LDH as well as of skeletal muscle UCP3. On the other hand, prophylactic treatment of diabetic mice with HK M. aurum had no significant effect on their liver GLUT2 and skeletal muscle GLUT4 and LDH protein expression levels.

Conclusions

Our findings provide the first evidence that HK M. aurum possesses a hyperglycemia-lowering capacity and might support its future use as a food supplement for the amelioration of diabetes.

Mitochondrial Adaptation in Skeletal Muscle: Impact of Obesity, Caloric Restriction, and Dietary Compounds

PURPOSE OF REVIEW: The global obesity epidemic has become a major public health concern, necessitating comprehensive research into its adverse effects on various tissues within the human body. Among these tissues, skeletal muscle has gained attention due to its susceptibility to obesity-related alterations. Mitochondria are primary source of energy production in the skeletal muscle. Healthy skeletal muscle maintains constant mitochondrial content through continuous cycle of synthesis and degradation. However, obesity has been shown to disrupt this intricate balance. This review summarizes recent findings on the impact of obesity on skeletal muscle mitochondria structure and function. In addition, we summarize the molecular mechanism of mitochondrial quality control systems and how obesity impacts these systems. RECENT FINDINGS: Recent findings show various interventions aimed at mitigating mitochondrial dysfunction in obese model, encompassing strategies including caloric restriction and various dietary compounds. Obesity has deleterious effect on skeletal muscle mitochondria by disrupting mitochondrial biogenesis and dynamics. Caloric restriction, omega-3 fatty acids, resveratrol, and other dietary compounds enhance mitochondrial function and present promising therapeutic opportunities.

Diabetes Driven Oncogenesis and Anticancer Potential of Repurposed Antidiabetic Drug: A Systemic Review

Diabetes and cancer are two prevalent disorders, pose significant public health challenges and contribute substantially to global mortality rates, with solely 10 million reported cancer-related deaths in 2020. This review explores the pathological association between diabetes and diverse cancer progressions, examining molecular mechanisms and potential therapeutic intersections. From altered metabolic landscapes to dysregulated signaling pathways, the intricate links are delineated, offering a comprehensive understanding of diabetes as a modulator of tumorigenesis. Cancer cells develop drug resistance through mechanisms like enhanced drug efflux, genetic mutations, and altered drug metabolism, allowing them to survive despite chemotherapeutic agent. Glucose emerges as a pivotal player in diabetes progression, and serving as a crucial energy source for cancer cells, supporting their biosynthetic needs and adaptation to diverse microenvironments. Glycation, a non-enzymatic process that produces advanced glycation end products (AGEs), has been linked to the etiology of cancer and has been shown in a number of tumor forms, such as leiomyosarcomas, adenocarcinomas, and squamous cell carcinomas. Furthermore, in aggressive and metastatic breast cancer, the receptor for AGEs (RAGE) is increased, which may increase the malignancy of the tumor. Reprogramming glucose metabolism manifests as hallmark cancer features, including accelerated cell proliferation, angiogenesis, metastasis, and evasion of apoptosis. This manuscript encapsulates the dual narrative of diabetes as a driver of cancer progression and the potential of repurposed antidiabetic drugs as formidable countermeasures. The amalgamation of mechanistic understanding and clinical trial outcomes establishes a robust foundation for further translational research and therapeutic advancements in the dynamic intersection of diabetes and cancer.

Genetic analysis of impaired healing responses after periodontal therapy in type 2 diabetes: Clinical and in vivo studies

OBJECTIVE

This study aims to investigate the mechanisms underlying the impaired healing response by diabetes after periodontal therapy.

BACKGROUND

Outcomes of periodontal therapy in patients with diabetes are impaired compared with those in patients without diabetes. However, the mechanisms underlying impaired healing response to periodontal therapy have not been sufficiently investigated.

MATERIALS AND METHODS

Zucker diabetic fatty (ZDF) and lean (ZL) rats underwent experimental periodontitis by ligating the mandibular molars for one week. The gingiva at the ligated sites was harvested one day after ligature removal, and gene expression was comprehensively analyzed using RNA-Seq. In patients with and without type 2 diabetes (T2D), the corresponding gene expression was quantified in the gingiva of the shallow sulcus and residual periodontal pocket after non-surgical periodontal therapy.

RESULTS

Ligation-induced bone resorption and its recovery after ligature removal were significantly impaired in the ZDF group than in the ZL group. The RNA-Seq analysis revealed 252 differentially expressed genes. Pathway analysis demonstrated the enrichment of downregulated genes involved in the peroxisome proliferator-activated receptor (PPAR) signaling pathway. PPARα and PPARγ were decreased in mRNA level and immunohistochemistry in the ZDF group than in the ZL group. In clinical, probing depth reduction was significantly less in the T2D group than control. Significantly downregulated expression of PPARα and PPARγ were detected in the residual periodontal pocket of the T2D group compared with those of the control group, but not in the shallow sulcus between the groups.

CONCLUSIONS

Downregulated PPAR subtypes expression may involve the impaired healing of periodontal tissues by diabetes.

A bioenergetically-active ploy (glycerol sebacate)-based multiblock hydrogel improved diabetic wound healing through revitalizing mitochondrial metabolism

Diabetic wounds impose significant burdens on patients' quality of life and healthcare resources due to impaired healing potential. Factors like hyperglycemia, oxidative stress, impaired angiogenesis and excessive inflammation contribute to the delayed healing trajectory. Mounting evidence indicates a close association between impaired mitochondrial function and diabetic complications, including chronic wounds. Mitochondria are critical for providing energy essential to wound healing processes. However, mitochondrial dysfunction exacerbates other pathological factors, creating detrimental cycles that hinder healing. This study conducted correlation analysis using clinical specimens, revealing a positive correlation between mitochondrial dysfunction and oxidative stress, inflammatory response and impaired angiogenesis in diabetic wounds. Restoring mitochondrial function becomes imperative for developing targeted therapies. Herein, we synthesized a biodegradable poly (glycerol sebacate)-based multiblock hydrogel, named poly (glycerol sebacate)-co-poly (ethylene glycol)-co-poly (propylene glycol) (PEPGS), which can be degraded in vivo to release glycerol, a crucial component in cellular metabolism, including mitochondrial respiration. We demonstrate the potential of PEPGS-based hydrogels to improve outcomes in diabetic wound healing by revitalizing mitochondrial metabolism. Furthermore, we investigate the underlying mechanism through proteomics analysis, unravelling the regulation of ATP and nicotinamide adenine dinucleotide metabolic processes, biosynthetic process and generation during mitochondrial metabolism. These findings highlight the therapeutic potential of PEPGS-based hydrogels as advanced wound dressings for diabetic wound healing.

Mitochondrial metabolism regulation and epigenetics in hypoxia

The complex and dynamic interaction between cellular energy control and gene expression modulation is shown by the intersection between mitochondrial metabolism and epigenetics in hypoxic environments. Poor oxygen delivery to tissues, or hypoxia, is a basic physiological stressor that sets off a series of reactions in cells to adapt and endure oxygen-starved environments. Often called the "powerhouse of the cell," mitochondria are essential to cellular metabolism, especially regarding producing energy through oxidative phosphorylation. The cellular response to hypoxia entails a change in mitochondrial metabolism to improve survival, including epigenetic modifications that control gene expression without altering the underlying genome. By altering the expression of genes involved in angiogenesis, cell survival, and metabolism, these epigenetic modifications help cells adapt to hypoxia. The sophisticated interplay between mitochondrial metabolism and epigenetics in hypoxia is highlighted by several important points, which have been summarized in the current article. Deciphering the relationship between mitochondrial metabolism and epigenetics during hypoxia is essential to understanding the molecular processes that regulate cellular adaptation to reduced oxygen concentrations.

The complex landscape of intracellular signalling in protein modification under hyperglycaemic stress leading to metabolic disorders

Hyperglycaemia is a life-threatening risk factor that occurs in both chronic and acute phases and has been linked to causing injury to many organs. Protein modification was triggered by hyperglycaemic stress, which resulted in pathogenic alterations such as impaired cellular function and tissue damage. Dysregulation in cellular function increases the condition associated with metabolic disorders, including cardiovascular diseases, nephropathy, retinopathy, and neuropathy. Hyperglycaemic stress also increases the proliferation of cancer cells. The major areas of experimental biomedical research have focused on the underlying mechanisms involved in the cellular signalling systems involved in diabetes-associated chronic hyperglycaemia. Reactive oxygen species and oxidative stress generated by hyperglycaemia modify many intracellular signalling pathways that result in insulin resistance and β-cell function degradation. The dysregulation of post translational modification in β cells is clinically associated with the development of diabetes mellitus and its associated diseases. This review will discuss the effect of hyperglycaemic stress on protein modification and the cellular signalling involved in it. The focus will be on the significant molecular changes associated with severe metabolic disorders.

Unlocking mitochondrial drug targets: The importance of mitochondrial transport proteins

A disturbed mitochondrial function contributes to the pathology of many common diseases. These organelles are therefore important therapeutic targets. On the contrary, many adverse effects of drugs can be explained by a mitochondrial off-target effect, in particular, due to an interaction with carrier proteins in the inner membrane. Yet this class of transport proteins remains underappreciated and understudied. The aim of this review is to provide a deeper understanding of the role of mitochondrial carriers in health and disease and their significance as drug targets. We present literature-based evidence that mitochondrial carrier proteins are associated with prevalent diseases and emphasize their potential as drug (off-)target sites by summarizing known mitochondrial drug-transporter interactions. Studying these carriers will enhance our knowledge of mitochondrial drug on- and off-targets and provide opportunities to further improve the efficacy and safety of drugs.

Quantitative Assessment of Peripheral Oxidative Metabolism With a New Dynamic 1H MRI Technique: A Pilot Study in People With and Without Diabetes Mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is linked to impaired mitochondrial function. Chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) is a gadolinium-contrast-free 1H method to assess mitochondrial function by measuring low-concentration metabolites. A CEST MRI-based technique may serve as a non-invasive proxy for assessing mitochondrial health.

HYPOTHESIS

A 1H CEST MRI technique may detect significant differences in in vivo skeletal muscle phosphocreatine (SMPCr) kinetics between healthy volunteers and T2DM patients undergoing standardized isometric exercise.

STUDY TYPE

Cross-sectional study.

SUBJECTS

Seven subjects without T2DM (T2DM-) and seven age, sex, and BMI-matched subjects with T2DM (T2DM+).

FIELD STRENGTH/SEQUENCE

Single-shot rapid acquisition with refocusing echoes (RARE) and single-shot gradient-echo sequences, 3 T.

ASSESSMENT

Subjects underwent a rest-exercise-recovery imaging protocol to dynamically acquire SMPCr maps in calf musculature. Medial gastrocnemius (MG) and soleus SMPCr concentrations were plotted over time, and SMPCr recovery time, τ , was determined. Mitochondrial function index was calculated as the ratio of resting SMPCr to τ . Participants underwent a second exercise protocol for imaging of skeletal muscle blood flow (SMBF), and its association with SMPCr was assessed.

STATISTICAL TESTS

Unpaired t-tests and Pearson correlation coefficient. A P value <0.05 was considered statistically significant.

RESULTS

SMPCr concentrations in MG and soleus displayed expected declines during exercise and returns to baseline during recovery. τ was significantly longer in the T2DM+ cohort (MG 83.5 ± 25.8 vs. 54.0 ± 21.1, soleus 90.5 ± 18.9 vs. 51.2 ± 14.5). The mitochondrial function index in the soleus was significantly lower in the T2DM+ cohort (0.33 ± 0.08 vs. 0.66 ± 0.19). SMBF was moderately correlated with the SMPCr in T2DM-; this correlation was not significant in T2DM+ (r = -0.23, P = 0.269).

CONCLUSION

The CEST MRI method is feasible for quantifying SMPCr in peripheral muscle tissue. T2DM+ individuals had significantly lower oxidative capacities than T2DM- individuals. In T2DM, skeletal muscle metabolism appeared to be decoupled from perfusion.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 1.

The mitochondrial tRNA-derived fragment, mt-tRF-LeuTAA, couples mitochondrial metabolism to insulin secretion

OBJECTIVE

The contribution of the mitochondrial electron transfer system to insulin secretion involves more than just energy provision. We identified a small RNA fragment (mt-tRF-LeuTAA) derived from the cleavage of a mitochondrially-encoded tRNA that is conserved between mice and humans. The role of mitochondrially-encoded tRNA-derived fragments remains unknown. This study aimed to characterize the impact of mt-tRF-LeuTAA, on mitochondrial metabolism and pancreatic islet functions.

METHODS

We used antisense oligonucleotides to reduce mt-tRF-LeuTAA levels in primary rat and human islet cells, as well as in insulin-secreting cell lines. We performed a joint transcriptome and proteome analysis upon mt-tRF-LeuTAA inhibition. Additionally, we employed pull-down assays followed by mass spectrometry to identify direct interactors of the fragment. Finally, we characterized the impact of mt-tRF-LeuTAA silencing on the coupling between mitochondrial metabolism and insulin secretion using high-resolution respirometry and insulin secretion assays.

RESULTS

Our study unveils a modulation of mt-tRF-LeuTAA levels in pancreatic islets in different Type 2 diabetes models and in response to changes in nutritional status. The level of the fragment is finely tuned by the mechanistic target of rapamycin complex 1. Located within mitochondria, mt-tRF-LeuTAA interacts with core subunits and assembly factors of respiratory complexes of the electron transfer system. Silencing of mt-tRF-LeuTAA in islet cells limits the inner mitochondrial membrane potential and impairs mitochondrial oxidative phosphorylation, predominantly by affecting the Succinate (via Complex II)-linked electron transfer pathway. Lowering mt-tRF-LeuTAA impairs insulin secretion of rat and human pancreatic β-cells.

CONCLUSIONS

Our findings indicate that mt-tRF-LeuTAA interacts with electron transfer system complexes and is a pivotal regulator of mitochondrial oxidative phosphorylation and its coupling to insulin secretion.

Cardiometabolic risk factors and neurodegeneration: a review of the mechanisms underlying diabetes, obesity and hypertension in Alzheimer's disease

A growing body of evidence suggests that cardiometabolic risk factors play a significant role in Alzheimer's disease (AD). Diabetes, obesity and hypertension are highly prevalent and can accelerate neurodegeneration and perpetuate the burden of AD. Insulin resistance and enzymes including insulin degrading enzymes are implicated in AD where breakdown of insulin is prioritised over amyloid-β. Leptin resistance and inflammation demonstrated by higher plasma and central nervous system levels of interleukin-6 (IL-6), IL-1β and tumour necrosis factor-α, are mechanisms connecting obesity and diabetes with AD. Leptin has been shown to ameliorate AD pathology and enhance long-term potentiation and hippocampal-dependent cognitive function. The renin-aldosterone angiotensin system, involved in hypertension, has been associated with AD pathology and neurotoxic reactive oxygen species, where angiotensin binds to specific angiotensin-1 receptors in the hippocampus and cerebral cortex. This review aims to consolidate the evidence behind putative processes stimulated by obesity, diabetes and hypertension, which leads to increased AD risk. We focus on how novel knowledge can be applied clinically to facilitate recognition of efficacious treatment strategies for AD.

The Benzoylpiperidine Fragment as a Privileged Structure in Medicinal Chemistry: A Comprehensive Review

The phenyl(piperidin-4-yl)methanone fragment (here referred to as the benzoylpiperidine fragment) is a privileged structure in the development of new drugs considering its presence in many bioactive small molecules with both therapeutic (such as anti-cancer, anti-psychotic, anti-thrombotic, anti-arrhythmic, anti-tubercular, anti-parasitic, anti-diabetic, and neuroprotective agents) and diagnostic properties. The benzoylpiperidine fragment is metabolically stable, and it is also considered a potential bioisostere of the piperazine ring, thus making it a feasible and reliable chemical frame to be exploited in drug design. Herein, we discuss the main therapeutic and diagnostic agents presenting the benzoylpiperidine motif in their structure, covering articles reported in the literature since 2000. A specific section is focused on the synthetic strategies adopted to obtain this versatile chemical portion.

Drp1 controls complex II assembly and skeletal muscle metabolism by Sdhaf2 action on mitochondria

The dynamin-related guanosine triphosphatase, Drp1 (encoded by Dnm1l), plays a central role in mitochondrial fission and is requisite for numerous cellular processes; however, its role in muscle metabolism remains unclear. Here, we show that, among human tissues, the highest number of gene correlations with DNM1L is in skeletal muscle. Knockdown of Drp1 (Drp1-KD) promoted mitochondrial hyperfusion in the muscle of male mice. Reduced fatty acid oxidation and impaired insulin action along with increased muscle succinate was observed in Drp1-KD muscle. Muscle Drp1-KD reduced complex II assembly and activity as a consequence of diminished mitochondrial translocation of succinate dehydrogenase assembly factor 2 (Sdhaf2). Restoration of Sdhaf2 normalized complex II activity, lipid oxidation, and insulin action in Drp1-KD myocytes. Drp1 is critical in maintaining mitochondrial complex II assembly, lipid oxidation, and insulin sensitivity, suggesting a mechanistic link between mitochondrial morphology and skeletal muscle metabolism, which is clinically relevant in combatting metabolic-related diseases.

Promoting mitochondrial dynamics by inhibiting the PINK1-PRKN pathway to relieve diabetic nephropathy

Diabetes is a metabolic disorder characterized by high blood glucose levels and is a leading cause of kidney disease. Diabetic nephropathy has been attributed to dysfunctional mitochondria. However, many questions remain about the exact mechanism. The structure, function and molecular pathways are highly conserved between mammalian podocytes and Drosophila nephrocytes; therefore, we used flies on a high-sucrose diet to model type 2 diabetic nephropathy. The nephrocytes from flies on a high-sucrose diet showed a significant functional decline and decreased cell size, associated with a shortened lifespan. Structurally, the nephrocyte filtration structure, known as the slit diaphragm, was disorganized. At the cellular level, we found altered mitochondrial dynamics and dysfunctional mitochondria. Regulating mitochondrial dynamics by either genetic modification of the Pink1-Park (mammalian PINK1-PRKN) pathway or treatment with BGP-15, mitigated the mitochondrial defects and nephrocyte functional decline. These findings support a role for Pink1-Park-mediated mitophagy and associated control of mitochondrial dynamics in diabetic nephropathy, and demonstrate that targeting this pathway might provide therapeutic benefits for type 2 diabetic nephropathy.

Interplay of mitochondria and diabetes: Unveiling novel therapeutic strategies

The interplay between mitochondrial function and diabetes has gained significant attention due to its crucial role in the pathogenesis and progression of the disease. Mitochondria, known as the cellular powerhouses, are essential for glucose metabolism. Dysfunction of these organelles has been implicated in the development of insulin resistance and beta-cell failure, both prominent features of diabetes. This comprehensive review explores the intricate mechanisms involved, including the generation of reactive oxygen species and the impact of mitochondrial DNA (mtDNA) mutations. Moreover, the review delves into emerging therapeutic strategies that specifically target mitochondria, such as mitochondria-targeted antioxidants, agents promoting mitochondrial biogenesis, and compounds modulating mitochondrial dynamics. The potential of these novel approaches is critically evaluated, taking into account their benefits and limitations, to provide a well-rounded perspective. Ultimately, this review emphasizes the importance of advancing our understanding of mitochondrial biology to revolutionize the treatment of diabetes.

Novel peptides from sea cucumber intestines hydrolyzed by neutral protease alleviate exercise-induced fatigue via upregulating the glutaminemediated Ca2+ /Calcineurin signaling pathway in mice

Sea cucumber intestines are considered a valuable resource in the sea cucumber processing industry due to their balanced amino acid composition. Studies have reported that peptides rich in glutamate and branched-chain amino acids have anti-fatigue properties. However, the function of the sea cucumber intestine in reducing exercise-induced fatigue remains unclear. In this study, we enzymatically hydrolyzed low molecular weight peptides from sea cucumber intestines (SCIP) and administered SCIP orally to mice to examine its effects on exercise-induced fatigue using swimming and pole-climbing exhaustion experiments. The results revealed that supplementation with SCIP significantly prolonged the exhaustion time of swimming in mice, decreased blood lactate and urea nitrogen levels, and increased liver and muscle glycogen levels following a weight-loaded swimming test. Immunofluorescence analysis indicated a notable increase the proportion of slow-twitch muscle fiber and a significant decrease the proportion of fast-twitch muscle fiber following SCIP supplementation. Furthermore, SCIP upregulated mRNA expression levels of Ca2+ /Calcineurin upstream and downstream regulators, thereby contributing to the promotion of skeletal muscle fiber type conversion. This study presents the initial evidence establishing SCIP as a potential enhancer of skeletal muscle fatigue resistance, consequently providing a theoretical foundation for the valuable utilization of sea cucumber intestines.

Exploring mitochondrial metabolism of wild-type and diabetic mice skin explants using the Seahorse technology

BACKGROUND

Skin wound healing is a complex mechanism which requires a lot of energy, mainly provided by mitochondrial respiration. However, little is known about the mitochondrial bioenergetics of mice skin. We sought to develop a microplate-based assay to directly measure oxygen consumption in whole mice skin with the goal of identifying mitochondrial dysfunction in diabetic skin using an extracellular flux.

MATERIALS AND METHODS

Different parameters were optimized to efficiently measure the oxygen consumption rate (OCR). First, the most pertinent skin side of wild-type mice was first determined. Then, concentrations of mitochondrial inhibitors were then optimized to get the best efficacy. Finally, punch sizes were modulated to get the best OCR profile.

RESULTS

Dermis had the best metabolic activity side of the skin. Unlike the increased concentrations of carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP) and rotenone/antimycin A, which showed no improvement of these drugs' effects, varying the skin punch size was successful. Finally, type II diabetic (T2D) skin produced less ATP through mitochondrial metabolism and had a greater non-mitochondrial oxygen consumption than wild-type or type I diabetic (T1D) skin.

CONCLUSION

Here we designed, for the first time, a reliable protocol to measure mitochondria function in whole mouse skin. Our optimized protocol was valuable in assessing alterations associated with diabetes and could be applied to future studies of pathological human skin metabolism.

Renal Mitochondrial ATP Transporter Ablation Ameliorates Obesity-Induced CKD

SIGNIFICANCE STATEMENT

This study sheds light on the central role of adenine nucleotide translocase 2 (ANT2) in the pathogenesis of obesity-induced CKD. Our data demonstrate that ANT2 depletion in renal proximal tubule cells (RPTCs) leads to a shift in their primary metabolic program from fatty acid oxidation to aerobic glycolysis, resulting in mitochondrial protection, cellular survival, and preservation of renal function. These findings provide new insights into the underlying mechanisms of obesity-induced CKD and have the potential to be translated toward the development of targeted therapeutic strategies for this debilitating condition.

BACKGROUND

The impairment in ATP production and transport in RPTCs has been linked to the pathogenesis of obesity-induced CKD. This condition is characterized by kidney dysfunction, inflammation, lipotoxicity, and fibrosis. In this study, we investigated the role of ANT2, which serves as the primary regulator of cellular ATP content in RPTCs, in the development of obesity-induced CKD.

METHODS

We generated RPTC-specific ANT2 knockout ( RPTC-ANT2-/- ) mice, which were then subjected to a 24-week high-fat diet-feeding regimen. We conducted comprehensive assessment of renal morphology, function, and metabolic alterations of these mice. In addition, we used large-scale transcriptomics, proteomics, and metabolomics analyses to gain insights into the role of ANT2 in regulating mitochondrial function, RPTC physiology, and overall renal health.

RESULTS

Our findings revealed that obese RPTC-ANT2-/- mice displayed preserved renal morphology and function, along with a notable absence of kidney lipotoxicity and fibrosis. The depletion of Ant2 in RPTCs led to a fundamental rewiring of their primary metabolic program. Specifically, these cells shifted from oxidizing fatty acids as their primary energy source to favoring aerobic glycolysis, a phenomenon mediated by the testis-selective Ant4.

CONCLUSIONS

We propose a significant role for RPTC-Ant2 in the development of obesity-induced CKD. The nullification of RPTC-Ant2 triggers a cascade of cellular mechanisms, including mitochondrial protection, enhanced RPTC survival, and ultimately the preservation of kidney function. These findings shed new light on the complex metabolic pathways contributing to CKD development and suggest potential therapeutic targets for this condition.

Preoperative Patient Evaluation: Newer Hypoglycemic Agents

New medications in the treatment of diabetes are an active area of research and drug development. Although many hypoglycemic therapies have been in use for decades, new evidence continues to emerge highlighting benefits of these medications for other indications. In this article, the authors review the classes of newer hypoglycemic agents and summarize medications currently in phase 2 and 3 clinical trials. The literature to support specific recommendations for perioperative management is scant, however, where it exists, we have included it. In other instances, the authors have noted a reasonable approach based on pharmacokinetics and principles of perioperative medication management.

Effects of short-term exercise and endurance training on skeletal muscle mitochondria damage induced by particular matter, atmospherically relevant artificial PM2.5

Introduction

This study aimed to investigate the potential of short-term aerobic exercise to mitigate skeletal muscle mitochondrial damage following ambient PM2.5 exposure, and how 12 weeks of endurance training can enhance aerobic fitness to protect against such damage.

Methods

Twenty-four male C57BL/6 J mice were split into sedentary (SED, n = 12) and endurance training (ETR, n = 12) groups. The ETR group underwent 12 weeks of training (10-15 m/min, 60 min/day, 4 times/week), confirmed by an Endurance Exercise Capacity (EEC) test. Post-initial training, the SED group was further divided into SSED (SED and sedentary, n = 6) and SPE (SED and PM2.5 + Exercise, n = 6). Similarly, the ETR group was divided into EEX (ETR and Exercise, n = 6) and EPE (ETR and PM2.5 + Exercise, n = 6). These groups underwent 1 week of atmospherically relevant artificial PM2.5 exposure and treadmill running (3 times/week). Following treatments, an EEC test was conducted, and mice were sacrificed for blood and skeletal muscle extraction. Blood samples were analyzed for oxidative stress indicators, while skeletal muscles were assessed for mitochondrial oxidative metabolism, antioxidant capacity, and mitochondrial damage using western blot and transmission electron microscopy (TEM).

Results

After 12 weeks of endurance training, the EEC significantly increased (p < 0.000) in the ETR group compared to the SED group. Following a one-week comparison among the four groups with atmospherically relevant artificial PM2.5 exposure and exercise treatment post-endurance training, the EEX group showed improvements in EEC, oxidative metabolism, mitochondrial dynamics, and antioxidant functions. Conversely, these factors decreased in the EPE group compared to the EEX. Additionally, within the SPE group, exercise effects were evident in HK2, LDH, SOD2, and GPX4, while no impact of short-term exercise was observed in all other factors. TEM images revealed no evidence of mitochondrial damage in both the SED and EEX groups, while the majority of mitochondria were damaged in the SPE group. The EPE group also exhibited damaged mitochondria, although significantly less than the SPE group.

Conclusion

Atmospherically relevant artificial PM2.5 exposure can elevate oxidative stress, potentially disrupting the benefits of short-term endurance exercise and leading to mitochondrial damage. Nonetheless, increased aerobic fitness through endurance training can mitigate PM2.5-induced mitochondrial damage.

The Arylamine N-Acetyltransferases as Therapeutic Targets in Metabolic Diseases Associated with Mitochondrial Dysfunction

In humans, there are two arylamine N-acetyltransferase genes that encode functional enzymes (NAT1 and NAT2) as well as one pseudogene, all of which are located together on chromosome 8. Although they were first identified by their role in the acetylation of drugs and other xenobiotics, recent studies have shown strong associations for both enzymes in a variety of diseases, including cancer, cardiovascular disease, and diabetes. There is growing evidence that this association may be causal. Consistently, NAT1 and NAT2 are shown to be required for healthy mitochondria. This review discusses the current literature on the role of both NAT1 and NAT2 in mitochondrial bioenergetics. It will attempt to relate our understanding of the evolution of the two genes with biologic function and then present evidence that several major metabolic diseases are influenced by NAT1 and NAT2. Finally, it will discuss current and future approaches to inhibit or enhance NAT1 and NAT2 activity/expression using small-molecule drugs. SIGNIFICANCE STATEMENT: The arylamine N-acetyltransferases (NATs) NAT1 and NAT2 share common features in their associations with mitochondrial bioenergetics. This review discusses mitochondrial function as it relates to health and disease, and the importance of NAT in mitochondrial function and dysfunction. It also compares NAT1 and NAT2 to highlight their functional similarities and differences. Both NAT1 and NAT2 are potential drug targets for diseases where mitochondrial dysfunction is a hallmark of onset and progression.

Actovegin improves skeletal muscle mitochondrial respiration and functional aerobic capacity in a type 1 diabetic male murine model

Insulin deficiency in type 1 diabetes (T1D) leads to an impairment of glucose metabolism and mitochondrial function. Actovegin is a hemodialysate of calf blood, which has been shown to enhance glucose uptake and cell metabolism in healthy human skeletal muscle. The objectives of this study were to determine the effects of Actovegin on skeletal muscle mitochondrial respiration and functional aerobic capacity in a T1D mouse model. Effects on the expression of mitochondrial proteins, body mass, and food and water consumption were also investigated. Streptozotocin-induced T1D male C57B1/6 mice (aged 3-4 months) were randomized to an Actovegin group and a control group. Every third day, the Actovegin and control groups were injected intraperitoneally with (0.1 mL) Actovegin and (0.1 mL) physiological salt solution, respectively. Oxidative phosphorylation (OXPHOS) capacity of the vastus lateralis muscle was measured by high resolution respirometry in addition to the expression levels of the mitochondrial complexes as well as voltage-dependent anion channel. Functional aerobic capacity was measured using a rodent treadmill protocol. Body mass and food and water consumption were also measured. After 13 days, in comparison to the control group, the Actovegin group demonstrated a significantly higher skeletal muscle mitochondrial respiratory capacity in an ADP-restricted and ADP-stimulated environment. The Actovegin group displayed a significantly lesser decline in functional aerobic capacity and baseline body mass after 13 days. There were no significant differences in food or water consumption between groups. Actovegin could act as an effective agent for facilitating glucose metabolism and improving OXPHOS capacity and functional aerobic capacity in T1D. Further investigation is warranted to establish Actovegin's potential as an alternative therapeutic drug for T1D.

Effect of atorvastatin on muscle tissues of dermatomyositis and antisynthetase syndrome patients with dyslipidemia

INTRODUCTION

In a recent study, we have shown that atorvastatin is clinically safe for dermatomyositis (DM) and antisynthetase syndrome (ASS) patients with dyslipidemia. Herein, we showed in an unprecedented way, the safety of atorvastatin on the muscular tissues of these patients.

METHODS

Transcriptome analysis was performed on samples of the vastus lateralis muscle obtained at baseline and after 12 weeks of atorvastatin (20 mg/day) intervention in DM or ASS patients with dyslipidemia [6DM and 5ASS received atorvastatin, and 2DM and 3ASS received placebo]. The results were analyzed considering differences in expression fold change before and after treatment. Histological and histochemical analyses were also performed.

RESULTS

In both groups, no significant changes were observed in genes related to the mitochondrial, oxidative, insulin, lipid, and fibrogenic pathways. Histological analysis showed a slight variability in the fiber size that was preserved after the intervention. In addition, the mosaic of muscle fibers was preserved in the internal architecture of the fibers and all histological regions. No fiber necrosis or atrophy, focal failures, subsarcolemmal accumulation, lipids, areas of fibrosis, or alterations in mitochondrial activity were observed. All muscle fibers were labeled for MHC I.

CONCLUSION

Atorvastatin did not promote significant changes in the expression of genes related to mitochondrial, oxidative, insulin, lipid, and fibrogenic pathways in the muscle tissues of DM and ASS patients with dyslipidemia. Atorvastatin did not also promote histological and histochemical changes in muscle tissues. Our results reinforce the safety of the administration of atorvastatin to treat dyslipidemia in patients with DM and ASS.

Piperine modulates IR/Akt/GLUT4 pathways to mitigate insulin resistance: Evidence from animal and computational studies

The global prevalence of diabetes mellitus is rising, especially in India. Medicinal herbs, whether used alone or in combination with conventional medicines, have shown promise in managing diabetes and improving overall well-being. Piperine (PIP), a major bioactive compound found in pepper, is gaining attention for its beneficial properties. This study aimed to assess whether PIP could alleviate diabetes by targeting insulin pathway-related molecules in the adipose tissue of rats on a high-fat diet (HFD). After 60 days on the HFD, rats received PIP at a dose of 40 mg/kg body weight for one month. The results showed that PIP significantly improved metabolic indicators, antioxidant enzymes, and carbohydrate metabolic enzymes. It also regulated the mRNA and protein expression of insulin signaling, which had been disrupted by the diet and sucrose intake. Molecular docking analysis also revealed strong binding of PIP to key diabetes-related regulatory proteins, including Akt (-6.2 kcal/mol), IR (-7.02 kcal/mol), IRS-1 (-6.86 kcal/mol), GLUT4 (-6.24 kcal/mol), AS160 (-6.28 kcal/mol), and β-arrestin (-6.01 kcal/mol). Hence, PIP may influence the regulation of glucose metabolism through effective interactions with these proteins, thereby controlling blood sugar levels due to its potent antilipidemic and antioxidant properties. In conclusion, our study provides in vivo experimental evidence against the HFD-induced T2DM model for the first time, making PIP a potential natural remedy to enhance the quality of life for diabetic patients and aid in their management.

Key Therapeutic Targets to Treat Hyperglycemia-Induced Atherosclerosis Analyzed Using a Petri Net-Based Model

Chronic superphysiological glucose concentration is a hallmark of diabetes mellitus (DM) and a cause of damage to many types of cells. Atherosclerosis coexists with glucose metabolism disturbances, constituting a significant problem and exacerbating its complications. Atherosclerosis in DM is accelerated, so it is vital to slow its progression. However, from the complex network of interdependencies, molecules, and processes involved, choosing which ones should be inhibited without blocking the pathways crucial for the organism's functioning is challenging. To conduct this type of analysis, in silicotesting comes in handy. In our study, to identify sites in the network that need to be blocked to have an inhibitory effect on atherosclerosis in hyperglycemia, which is toxic for the human organism, we created a model using Petri net theory and performed analyses. We have found that blocking isoforms of protein kinase C (PKC)-PKCβ and PKCγ-in diabetic patients can contribute to the inhibition of atherosclerosis progression. In addition, we have discovered that aldose reductase inhibition can slow down atherosclerosis progression, and this has been shown to reduce PKC (β and γ) expression in DM. It has also been observed that diminishing oxidative stress through the inhibitory effect on the AGE-RAGE axis may be a promising therapeutic approach in treating hyperglycemia-induced atherosclerosis. Moreover, the blockade of NADPH oxidase, the key enzyme responsible for the formation of reactive oxygen species (ROS) in blood vessels, only moderately slowed down atherosclerosis development. However, unlike aldose reductase blockade, or direct PKC (β and γ), the increased production of mitochondrial ROS associated with mitochondrial dysfunction effectively stopped after NADPH oxidase blockade. The results obtained may constitute the basis for further in-depth research.

Local low-frequency vibration accelerates healing of full-thickness wounds in a hyperglycemic rat model

AIMS/INTRODUCTION

Local low-frequency vibration (LLFV) promotes vasodilation and blood flow, enhancing wound healing in diabetic foot ulcers with angiopathy. However, vibration-induced vasodilation does not occur, owing to chronic hyperglycemia and inflammation. We hypothesized that LLFV improves glycometabolism and inflammation, leading to vasodilation and angiogenesis in diabetic wounds. Therefore, this study investigated the effect of LLFV on wound healing in hyperglycemic rats, primarily focusing on glycometabolism, inflammation, vasodilation, and angiogenesis.

MATERIALS AND METHODS

Streptozotocin-induced hyperglycemic Sprague-Dawley rats were used in this study. We applied LLFV to experimentally-induced wounds at 50 Hz and 0, 600, 1,000 or 1,500 mVpp for 40 min/day from post-wounding days (PWD) 1-14.

RESULTS

The relative wound areas in the 600 and 1,000 mVpp groups on PWD 5-7 were significantly smaller than those at 0 mVpp. The expression of Glo-1 (1,500 mVpp) and Slc2A4 (1,000 and 1,500 mVpp) was upregulated on PWD 4 and 14, respectively. However, there was no difference in methylglyoxal expression levels in any group until PWD 14. At 1,000 mVpp, the expression of Tnfa on PWD 4, and that of Ptx3 and Ccl2 on PWD 14 was downregulated. Furthermore, the M1/M2 macrophage ratio was considerably decreased on both days. The expression of Nos3, Vegfa and vascular endothelial growth factor A was upregulated on PWD 4. In addition, vasodilation and angiogenesis were more obvious on PWD 14 with 1,000 mVpp.

CONCLUSIONS

The results suggest that LLFV promotes wound healing, improves glycometabolism and inflammation, and enhances vasodilation and angiogenesis in hyperglycemic wounds.

Lentinan alleviates diabetic cardiomyopathy by suppressing CAV1/SDHA-regulated mitochondrial dysfunction

Diabetic cardiomyopathy (DCM), characterized by mitochondrial dysfunction and impaired energetics as contributing factors, significantly contributes to high mortality in patients with diabetes. Targeting key proteins involved in mitochondrial dysfunction might offer new therapeutic possibilities for DCM. Lentinan (LNT), a β-(1,3)-glucan polysaccharide obtained from lentinus edodes, has demonstrated biological activity in modulating metabolic syndrome. In this study, the authors investigate LNT's pharmacological effects on and mechanisms against DCM. The results demonstrate that administering LNT to db/db mice reduces cardiomyocyte apoptosis and mitochondrial dysfunction, thereby preventing DCM. Notably, these effects are fully negated by Caveolin-1 (CAV1) overexpression both in vivo and in vitro. Further studies and bioinformatics analysis uncovered that CAV1 bound with Succinate dehydrogenase subunit A (SDHA), triggering the following ubiquitination and degradation of SDHA, which leads to mitochondrial dysfunction and mitochondria-derived apoptosis under PA condition. Silencing CAV1 leads to reduced apoptosis and improved mitochondrial function, which is blocked by SDHA knockdown. In conclusion, CAV1 directly interacts with SDHA to promote ubiquitination and proteasomal degradation, resulting in mitochondrial dysfunction and mitochondria-derived apoptosis, which was depressed by LNT administration. Therefore, LNT may be a potential pharmacological agent in preventing DCM, and targeting the CAV1/SDHA pathway may be a promising therapeutic approach for DCM.