Decreased ATP Production Research Articles

Different Effects of Berberine Delivery to Mitochondria on Cells Derived from the Neural Crest.

Energy metabolism is crucial for cell polarity and pathogenesis. Mitochondria, which are essential for maintaining energy homeostasis within cells, can be targeted by drug delivery to regulate energy metabolism. However, there is a lack of research comparing how mitochondria control energy metabolism in different cell types derived from the neural crest. Understanding the effects of berberine (BBR), a compound that acts on mitochondria, on energy metabolism in neural crest-derived cells is important. This study reports how MITO-Porter, a mitochondria-targeted liposome, affects neuroblasts (Neuro2a cells) and normal human epidermal melanocytes (NHEMs) when loaded with BBR. We found that treatment with MITO-Porter containing BBR reduced mitochondrial respiration in Neuro2a cells, while it caused a slight increase in NHEMs. Additionally, the treatment shifted the ATP production pathway in Neuro2a cells to rely more on glycolysis, while in NHEMs, there was a slight decrease in the reliance on glycolysis. We also observed a significant decrease in ATP production in Neuro2a cells, while NHEMs showed a tendency to increase ATP production. Importantly, on the basis of the results of the Premix WST-1 assay, the study found that BBR treatment was not toxic to either cell type. It is important to take note of the varied effects of BBR treatment on different cell types derived from the neural crest. These findings necessitate attention when utilizing NHEMs as a cell model in the development of therapeutic strategies for neurodegenerative diseases, including the use of BBR for metabolic control.

Di-(2-ethylhexyl) Phthalate Exposure Induces Developmental Toxicity in the Mouse Fetal Heart via Mitochondrial Dysfunction.

Congenital heart disease (CHD) is a major cause of infant mortality and morbidity, with growing interest in the role of environmental factors in its etiology. Di-(2-ethylhexyl) phthalate (DEHP), an environmental endocrine disruptor, has been implicated in the development of CHD. This study aimed to investigate the effects of DEHP exposure on fetal heart development in mice. Pregnant mice exposed to DEHP exhibited increased fetal malformations, decreased fetal weight, and reduced crown-rump length.f Transcriptomic analysis revealed the downregulation of genes involved in aerobic respiration and mitochondrial ATP synthesis. Functional assays demonstrated reduced mitochondrial respiration, decreased ATP production, elevated reactive oxygen species levels, and lowered mitochondrial membrane potential in DEHP-exposed fetal cardiomyocytes. These findings underscore the detrimental effects of DEHP on fetal cardiac health and provide insights into the molecular mechanisms underlying DEHP-induced CHD. Understanding these mechanisms is crucial for developing preventive strategies against environmental toxicants that affect fetal cardiac development.

Apelin regulates mitochondrial dynamics by inhibiting Mst1-JNK-Drp1 signaling pathway to reduce neuronal apoptosis after spinal cord injury

In the secondary injury stage of spinal cord injury, mitochondrial dysfunction leads to decreased ATP production, increased ROS production, and activation of the mitochondria-mediated apoptosis signaling pathway. This ultimately intensifies neuronal death and promotes the progression of the injury. Apelin, a peptide produced by the APLN gene, has demonstrated promise in the treatment of spinal cord injury. The aim of this study was to investigate how Apelin protects neurons after spinal cord injury by influencing the mitochondrial dynamics. The results showed that Apelin has the ability to reduce mitochondrial fission, enhance the mitochondrial membrane potential, improve antioxidant capacity, facilitate the clearance of excess ROS, and ultimately decrease apoptosis in PC12 cells. Moreover, Apelin is overexpressed in neurons in the damaged part of the spinal cord, contributing to reduce mitochondrial fission, improve antioxidant capacity, increase ATP production, decrease apoptosis, promote spinal cord morphological repair, maintain the number of nissl bodies, and enhance signal transduction in the descending spinal cord pathway. Apelin exerts its protective effect by inhibiting the Mst1-JNK-Drp1 signaling pathway. In summary, our study further improved the effect of Apelin in the treatment of spinal cord injury, revealed the mechanism of Apelin in protecting damaged neurons after spinal cord injury by maintaining mitochondrial homeostasis, and provided a new therapeutic mechanism for Apelin in spinal cord injury.

Hydrogen Sulfide Modulates Astrocytic Toxicity in Mouse Spinal Cord Cultures: Implications for Amyotrophic Lateral Sclerosis.

Hydrogen sulfide (H2S), a known inhibitor of the electron transport chain, is endogenously produced in the periphery as well as in the central nervous system, where is mainly generated by glial cells. It affects, as a cellular signaling molecule, many different biochemical processes. In the central nervous system, depending on its concentration, it can be protective or damaging to neurons. In the study, we have demonstrated, in a primary mouse spinal cord cultures, that it is particularly harmful to motor neurons, is produced by glial cells, and is stimulated by inflammation. However, its role on glial cells, especially astrocytes, is still under-investigated. The present study was designed to evaluate the impact of H2S on astrocytes and their phenotypic heterogeneity, together with the functionality and homeostasis of mitochondria in primary spinal cord cultures. We found that H2S modulates astrocytes' morphological changes and their phenotypic transformation, exerts toxic properties by decreasing ATP production and the mitochondrial respiration rate, disturbs mitochondrial depolarization, and alters the energetic metabolism. These results further support the hypothesis that H2S is a toxic mediator, mainly released by astrocytes, possibly acting as an autocrine factor toward astrocytes, and probably involved in the non-cell autonomous mechanisms leading to motor neuron death.

Impact of seawater warming and nutrient deprivation on the physiology and energy metabolism of corals

Seawater temperature and the availability of dissolved inorganic nutrients (DINut) have a major influence on the stability of the symbiosis between corals and Symbiodiniaceae. In particular, seawater warming or DINut depletion can lead to coral bleaching, the loss of Symbiodiniaceae from coral tissue. However, the combined effects of heat stress and DINut deficiency on the coral energy metabolism are still understudied. Here, we investigated the physiological and energetic responses of the octocoral Heteroxenia fuscescens and the hexacoral Stylophora pistillata exposed to two levels of inorganic nutrients in seawater (control, depleted) and two temperatures, 25°C (control) and 30°C (high temperature), in a crossed factorial design. Our results show that thermal and DINut stress both decreased the photosynthesis to respiration ratio of the two species and induced bleaching in H. fuscescens. While nutrient deprivation had little effect on the corals’ energy metabolism, heat stress led to higher concentrations of macromolecules such as carbohydrates and lipids, as well as anaerobic metabolism, and decreased ATP production in H. fuscescens. Given that the intensity and frequency of marine heatwaves will significantly increase in the future, there is an urgent need to investigate the processes by which corals can overcome starvation.

Telomerase reverse transcriptase protects against diabetic kidney disease by promoting AMPK/PGC-1a-regulated mitochondrial energy homeostasis

Disordered glucose and lipid metabolism, coupled with disturbed mitochondrial bioenergetics, are pivotal in the initiation and development of diabetic kidney disease (DKD). While the essential role of telomerase reverse transcriptase (TERT) in regulating mitochondrial function in the cardiovascular system has been recognized, its specific function in maintaining mitochondrial homeostasis in DKD remains unclear. This study aimed to explore how TERT regulates mitochondrial function and the underlying mechanisms. In vitro, human renal proximal tubular HK-2 cells exposed to high glucose/high fat (HG/HF) presented significant downregulation of TERT and AMPK dephosphorylation. This led to decreased ATP production, altered NAD+/NADH ratios, reduced mitochondrial complex activities, increased mitochondrial dysfunction, lipid accumulation, and reactive oxygen species (ROS) production. Knockdown of TERT (si-TERT) further exacerbated mitochondrial dysfunction, decreased mitochondrial membrane potential, and lowered levels of cellular oxidative phosphorylation and glycolysis, as determined via a Seahorse X24 flux analyzer. Conversely, mitochondrial dysfunction was significantly alleviated after pcDNA-TERT plasmid transfection and adeno-associated virus (AAV) 9-TERT gene therapy in vivo. Notably, treatment with an AMPK inhibitor, activator, and si-PGC-1a (peroxisome proliferator-activated receptor γ coactivator-1α), resulted in mitochondrial dysfunction and decreased expression of genes related to energy metabolism and mitochondrial biogenesis. Our findings reveal that TERT protects mitochondrial function and homeostasis by partially activating the AMPK/PGC-1a signaling pathway. These results establish a crucial foundation for understanding TERT's critical role inmitochondrial regulation and its protective effect on DKD.

Mitochondrial Dysfunction in Aristolochic Acid I-Induced Kidney Diseases: What We Know and What We Do Not Know

Aristolochic acids, compounds derived from Aristolochiaceae plant species, are associated with significant renal nephrotoxicity and carcinogenicity. Aristolochic acid I (AAI), the most predominant and potent of these compounds, is a primary etiological agent in acute and chronic kidney diseases such as Aristolochic Acid Nephropathy (AAN) and Balkan Endemic Nephropathy (BEN). Due to the kidneys’ critical role in xenobiotic excretion, they are the primary organs affected by AAI toxicity. Recent in vitro and in vivo studies have highlighted mitochondrial dysfunction as a crucial factor in the pathogenesis of these kidney diseases. This review provides an update on the recent advances in understanding the causes of acquired mitochondrial dysfunction within the context of AAN and BEN. Key findings include the identification of mitochondrial DNA depletion, loss of mitochondrial membrane potential, and decreased ATP production as significant contributors to kidney damage. Additionally, oxidative stress markers and inflammatory mediators have been implicated in disease progression. Potential therapeutic approaches, such as the use of antioxidants like vitamin C and catalpol, have shown promise in mitigating AAI-induced cytotoxicity. Furthermore, future predictive approaches like pharmacogenomics could pave the way for novel mitochondria-targeted treatments. A comprehensive characterization of mitochondrial function, its underlying molecular mechanisms, and specific biomarkers could offer valuable insights and potential therapeutic options, significantly impacting the current management of AAN and BEN.

Risperidone-induced bioenergetic disruption in the isolated human peripheral blood monocytes

Risperidone (RIS) is a widely used antipsychotic drug with reported alteration in immune response. The current study investigated mitochondrial disruption as the underlying mechanism of RIS-induced immunotoxicity in isolated human peripheral blood monocytes (hPBM). RIS was cytotoxic to hPBM in exposure duration and concentration-dependent patterns. Functionally, RIS was shown to increase the release of IL-6, TNF-α, and IL-8 with a decrease in test particle phagocytosis in concertation and exposure time-based patterns. It was found that RIS decreased ATP production in isolated monocytes' mitochondria, with an estimated EC50 of around 70 μM after 24 h with parallel inhibition of mitochondrial complexes I and III activities and decreased mitochondrial membrane potential and oxygen consumption rates with increased lactate production from by the treated cells in comparison to controls. Structurally, RIS in 100 μM concentration significantly increased the mitochondrial membrane fluidity with significant increase in increased unsaturated/saturated fatty acids ratios of the mitochondrial membranes of the treated cells. Interestingly, water-soluble CoQ10 formulation significantly decreased the cytotoxic effect of RIS and improved the phagocytic activity of RIS-treated cells. To conclude, the current data suggests mitochondrial disruption as the underlying mechanism of RIS-induced immunotoxicity with shown protective effect of water-soluble CoQ10 formulation.

FOXO-regulated OSER1 reduces oxidative stress and extends lifespan in multiple species

FOXO transcription factors modulate aging-related pathways and influence longevity in multiple species, but the transcriptional targets that mediate these effects remain largely unknown. Here, we identify an evolutionarily conserved FOXO target gene, Oxidative stress-responsive serine-rich protein 1 (OSER1), whose overexpression extends lifespan in silkworms, nematodes, and flies, while its depletion correspondingly shortens lifespan. In flies, overexpression of OSER1 increases resistance to oxidative stress, starvation, and heat shock, while OSER1-depleted flies are more vulnerable to these stressors. In silkworms, hydrogen peroxide both induces and is scavenged by OSER1 in vitro and in vivo. Knockdown of OSER1 in Caenorhabditis elegans leads to increased ROS production and shorter lifespan, mitochondrial fragmentation, decreased ATP production, and altered transcription of mitochondrial genes. Human proteomic analysis suggests that OSER1 plays roles in oxidative stress response, cellular senescence, and reproduction, which is consistent with the data and suggests that OSER1 could play a role in fertility in silkworms and nematodes. Human studies demonstrate that polymorphic variants in OSER1 are associated with human longevity. In summary, OSER1 is an evolutionarily conserved FOXO-regulated protein that improves resistance to oxidative stress, maintains mitochondrial functional integrity, and increases lifespan in multiple species. Additional studies will clarify the role of OSER1 as a critical effector of healthy aging.

Mitochondrial bioenergetic dysfunction linked to myxomatous mitral valve degeneration explored by PBMCs metabolism analysis

Impaired mitochondria cause an impressive decrease in ATP production becoming a common condition of cardiovascular diseases. Myxomatous mitral valve disease (MMVD) is characterized by mitochondrial dysfunction. By a non-invasive procedure of metabolism analysis on peripheral blood mononuclear cells, we exploit ex-vivo studies that directly constitute a translational approach to evaluate the cell bioenergetics. Cell ATP production decreased in the presence of MMVD, whereas glycolysis was unaffected. In MMVD, the mitochondrial activity underwent a significant reduction of basal respiration, maximal respiration, and ATP production. Our results depicted a pathological condition of MMVD characterized by cell metabolism deprived of mitochondrial energy support.

Abstract Tu113: Metabolomic Profile of Human End-Stage Ischemic Cardiomyopathy Reveals Few Differences from Non-Ischemic Cardiomyopathy

Background: The heart is highly metabolic, relying on a range of fuels to sustain its high generation of ATP. The primary source of energy in the human heart is fatty acids, but fatty acid oxidation is reduced in failing hearts, contributing to a decrease in ATP production. Previously, we provided a comprehensive metabolic profile of human non-ischemic cardiomyopathy (NICM) hearts, including maintained ATP levels despite decreased energy charge (EC), lower acylcarnitines, acyl CoAs, and free fatty acids, suggesting a defect in fatty acid import. Research Questions: The pathogenesis of ischemic cardiomyopathy (ICM) is dramatically different from that of NICM, raising the question of whether metabolic defects differ between these two conditions. Aims: Our current study was therefore aimed at elucidating the metabolomic profile of end-stage ICM compared to that of NICM. Methods: Whole human hearts were obtained either from patients with end-stage heart failure (NICM or ICM) undergoing cardiac transplantation or from brain-dead organ donors. Hearts were arrested in situ and kept in ice-cold cardioplegia solution at all times. Transmural tissue samples were obtained from left ventricular free wall, snap frozen, and extracted metabolites were quantified by liquid chromatography coupled with mass spectrometer. Results: The comparison of metabolomics data from non-failing (NF) control heart samples and NICM samples were consistent with our previous study, with marked decrease in acylcarnitines and increase in lysophosphatidylcholine. On the other hand, the metabolomics profiles of ICM and NICM samples were remarkably similar. Phenylacetylglutamine and trimethylamine N-oxide, both related to atherosclerotic disease risk, were statistically significantly higher in ICM samples compared to NICM samples. Conclusion(s): The human cardiac metabolome of end-stage ICM is nearly identical to that of NICM, despite dramatically different pathogeneses, suggesting that end-stage heart failure constitutes a final common pathway. It would be of great interest to evaluate metabolomic profiles of the diseases differ at earlier timepoints.

Magnesium: A Defense Line to Mitigate Inflammation and Oxidative Stress in Adipose Tissue.

Magnesium (Mg) is involved in essential cellular and physiological processes. Globally, inadequate consumption of Mg is widespread among populations, especially those who consume processed foods, and its homeostasis is impaired in obese individuals and type 2 diabetes patients. Since Mg deficiency triggers oxidative stress and chronic inflammation, common features of several frequent chronic non-communicable diseases, interest in this mineral is growing in clinical medicine as well as in biomedicine. To date, very little is known about the role of Mg deficiency in adipose tissue. In obesity, the increase in fat tissue leads to changes in the release of cytokines, causing low-grade inflammation and macrophage infiltration. Hypomagnesemia in obesity can potentiate the excessive production of reactive oxygen species, mitochondrial dysfunction, and decreased ATP production. Importantly, Mg plays a role in regulating intracellular calcium concentration and is involved in carbohydrate metabolism and insulin receptor activity. This narrative review aims to consolidate existing knowledge, identify research gaps, and raise awareness of the critical role of Mg in supporting adipose tissue metabolism and preventing oxidative stress.

N-acetyl Cysteine Overdose Induced Acute Toxicity and Hepatic Microvesicular Steatosis by Disrupting GSH and Interfering Lipid Metabolisms in Normal Mice.

N-acetyl cysteine (NAC) is a versatile drug used in various conditions, but the limitations and toxicities are not clear. The acute toxicity and toxicological mechanisms of an intraperitoneal injection of NAC in normal mice were deciphered. The LD50 for male and female BALB/cByJNarl mice were 800 mg/kg and 933 mg/kg. The toxicological mechanisms of 800 mg/kg NAC (N800) were investigated. The serum biomarkers of hepatic and renal indices dramatically increased, followed by hepatic microvesicular steatosis, renal tubular injury and necrosis, and splenic red pulp atrophy and loss. Thus, N800 resulted in mouse mortality mainly due to acute liver, kidney, and spleen damages. The safe dose (275 mg/kg) of NAC (N275) increased hepatic antioxidant capacity by increasing glutathione levels and catalase activity. N275 elevated the hepatic gene expressions of lipid transporter, lipid synthesis, β-oxidation, and ketogenesis, suggesting a balance between lipid production and consumption, and finally, increased ATP production. In contrast, N800 increased hepatic oxidative stress by decreasing glutathione levels through suppressing Gclc, and reducing catalase activity. N800 decreased the hepatic gene expressions of lipid transporter, lipid synthesis, and interferred β-oxidation, leading to lipid accumulation and increasing Cyp2E1 expression, and finally, decreased ATP production. Therefore, NAC doses are limited for normal individuals, especially via intraperitoneal injection or similar means.

Mitochondrial biogenesis disorder and oxidative damage promote refractory apical periodontitis in rat and human.

To elucidate whether mitochondrial biogenesis disorder and damage from oxidative stress promote refractory apical periodontitis (RAP) in rat and human. Twenty Enterococcus faecalis-induced RAPs were established in the maxillary first molars of male Wistar rats. Concurrently, 12 periapical lesion specimens from patients presenting with RAP were obtained by apicoectomy. Radiographic examination and histologic analysis were conducted to evaluate periapical bone tissue destruction and morphological changes. The expression of key regulators of mitochondrial biogenesis, PGC-1α and Nrf2, were detected by immunohistochemistry and double immunofluorescence staining, Western blot and real-time PCR were also assayed. Mitochondrial ROS (mtROS) was identified by MitoSOX staining. Mitochondrial function was detected by the quantification of ATP production, mitochondrial DNA (mtDNA) copy number and activities of mitochondrial respiratory chain complexes. Furthermore, mitochondrial oxidative stress was evaluated by the determination of 3-nitrotyrosine (3-NT), 4-hydroxy-2-nonenal (4-HNE) and 8-hydroxy-deoxyguanosine (8-OHdG) expression levels, as well as malondialdehyde (MDA) expression and antioxidant capacity. Student's t-test was performed to determine significance between the groups; p < .05 was considered significant. In the maxilla, significantly more bone resorption, greater number of periapical apoptotic cells and Tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells were observed in the RAP group compared with the control group (p < .01). PGC-1α and Nrf2 were significantly reduced in rat and human RAP lesions compared to the control group (p < .01) at both the mRNA and protein levels. Double immunofluorescence analysis of PGC-1α or Nrf2 with TOMM20 also indicated that mitochondrial biogenesis was impaired in RAP group (p < .01). Additionally, mitochondrial dysfunction was observed in RAP group, as reflected by increased mtROS, decreased ATP production, reduced mtDNA copy number and complexes of the mitochondrial respiratory chain. Finally, the expression levels of mitochondrial oxidative stress markers, 3-NT, 4-HNE and 8-OHdG, were significantly increased in the RAP group (p < .01). Consistent with this, systemic oxidative damage was also present in the progression of RAP, including increased MDA expression and decreased antioxidant activity (p < .01). Mitochondrial biogenesis disorder and damage from oxidative stress contribute to the development of RAP.

A novel mutation of DNA2 regulates neuronal cell membrane potential and epileptogenesis.

Mesial temporal lobe epilepsy (MTLE) is one of the most intractable epilepsies. Previously, we reported that mitochondrial DNA deletions were associated with epileptogenesis. While the underlying mechanism of mitochondrial DNA deletions during epileptogenesis remain unknown. In this study, a novel somatic mutation of DNA2 gene was identified in the hippocampal tissue of two MTLE patients carrying mitochondrial DNA deletions, and this mutation decreased the full-length expression of DNA2 protein significantly, aborting its normal functions. Then, we knocked down the DNA2 protein in zebrafish, and we demonstrated that zebrafish with DNA2 deficiency showed decreased expression of mitochondrial complex II-IV, and exhibited hallmarks of epileptic seizures, including abnormal development of the zebrafish and epileptiform discharge signals in brain, compared to the Cas9-control group. Moreover, our cell-based assays showed that DNA2 deletion resulted in accumulated mitochondrial DNA damage, abnormal oxidative phosphorylation and decreased ATP production in cells. Inadequate ATP generation in cells lead to declined Na+, K+-ATPase activity and change of cell membrane potential. Together, these disorders caused by DNA2 depletion increased cell apoptosis and inhibited the differentiation of SH-SY5Y into branched neuronal phenotype. In conclusion, DNA2 deficiency regulated the cell membrane potential via affecting ATP production by mitochondria and Na+, K+-ATPase activity, and also affected neuronal cell growth and differentiation. These disorders caused by DNA2 dysfunction are important causes of epilepsy. In summary, we are the first to report the pathogenic somatic mutation of DNA2 gene in the patients with MTLE disease, and we uncovered the mechanism of DNA2 regulating the epilepsy. This study provides new insight into the pathogenesis of epilepsy and underscore the value of DNA2 in epilepsy.

Rotenone activates the LKB1-AMPK-ULK1 signaling pathway to induce autophagy and apoptosis in rat thoracic aortic endothelial cells

BackgroundThe specific mechanism by which rotenone impacts thoracic aortic autophagy and apoptosis is unknown. We aimed to investigate the regulatory effects of rotenone on autophagy and apoptosis in rat thoracic aortic endothelial cells (RTAEC) via activation of the LKB1-AMPK-ULK1 signaling pathway and to elucidate the molecular mechanisms of rotenone on autophagy and apoptosis in vascular endothelial cells.MethodsIn vivo, 60 male SD rats were randomly selected and divided into 5 groups: control (Con), DMSO, 1, 2, and 4 mg/kg groups, respectively. After 28 days of treatment, histopathological and ultrastructural changes in each group were observed using HE and transmission electron microscopy; Autophagy, apoptosis, and LKB1-AMPK-ULK1 pathway-related proteins were detected by Western blot; Apoptosis levels in the thoracic aorta were detected by TUNEL. In vitro, RTAEC were cultured and divided into control (Con), DMSO, 20, 100, 500, and 1000 nM groups. After 24 h of intervention, autophagy, apoptosis, and LKB1-AMPK-ULK1 pathway-related factors were detected by Western blot and qRT-PCR; Flow cytometry to detect apoptosis levels; Autophagy was inhibited with 3-MA and CQ to detect apoptosis levels, and changes in autophagy, apoptosis, and downstream factors were detected by the AMPK inhibitor CC intervention.ResultsGavage in SD rats for 28 days, some degree of damage was observed in the thoracic aorta and heart of the rotenone group, as well as the appearance of autophagic vesicles was observed in the thoracic aorta. TUNEL analysis revealed higher apoptosis in the rotenone group’s thoracic aorta; RTAEC cultured in vitro, after 24 h of rotenone intervention, showed increased ROS production and significantly decreased ATP production. The flow cytometry data suggested an increase in the number of apoptotic RTAEC. The thoracic aorta and RTAEC in the rotenone group displayed elevated levels of autophagy and apoptosis, and the LKB1-AMPK-ULK1 pathway proteins were activated and expressed at higher levels. Apoptosis and autophagy were both suppressed by the autophagy inhibitors 3-MA and CQ. The AMPK inhibitor CC reduced autophagy and apoptosis in RTAEC and suppressed the production of the AMPK downstream factors ULK1 and P-ULK1.ConclusionsRotenone may promote autophagy in the thoracic aorta and RTAEC by activating the LKB1-AMPK-ULK1 signaling pathway, thereby inducing apoptosis.

Glucagon-like peptide-1 analogs activate AMP kinase leading to reversal of the Warburg metabolic switch in breast cancer cells.

Breast cancer (BC) is associated with type 2 diabetes mellitus (T2DM) and obesity. Glucagon-like peptide (GLP)-1 regulates post-prandial insulin secretion, satiety, and gastric emptying. Several GLP-1 analogs have been FDA-approved for the treatment of T2DM and obesity. Moreover, GLP-1 regulates various metabolic activities across different tissues by activating metabolic signaling pathways like adenosine monophosphate (AMP) activated protein kinase (AMPK), and AKT. Rewiring metabolic pathways is a recognized hallmark of cancer, regulated by several cancer-related pathways, including AKT and AMPK. As GLP-1 regulates AKT and AMPK, we hypothesized that it alters BC cells' metabolism, thus inhibiting proliferation. The effect of the GLP-1 analogs exendin-4 (Ex4) and liraglutide on viability, AMPK signaling and metabolism of BC cell lines were assessed. Viability of BC cells was evaluated using colony formation and MTT/XTT assays. Activation of AMPK and related signaling effects were evaluated using western blot. Metabolism effects were measured for glucose, lactate and ATP. Exendin-4 and liraglutide activated AMPK in a cAMP-dependent manner. Blocking Ex4-induced activation of AMPK by inhibition of AMPK restored cell viability. Interestingly, Ex4 and liraglutide reduced the levels of glycolytic metabolites and decreased ATP production, suggesting that GLP-1 analogs impair glycolysis. Notably, inhibiting AMPK reversed the decline in ATP levels, highlighting the role of AMPK in this process. These results establish a novel signaling pathway for GLP-1 in BC cells through cAMP and AMPK modulation affecting proliferation and metabolism. This study suggests that GLP-1 analogs should be considered for diabetic patients with BC.

104 Effects of providing vitamin and mineral supplementation throughout gestation on subsequent F1 replacement heifer liver and muscle oxygen consumption and mitochondrial function throughout pregnancy

Abstract The study aimed to assess the impact of maternal vitamin/mineral supplementation during gestation on the energy utilization in liver and muscle tissues of F1 heifer offspring. We hypothesized that VTM supplementation during gestation would mitigate mitochondrial energy loss and uncoupling of liver and muscle tissue in pregnant offspring. At breeding, crossbred Angus heifers [n = 31; initial body weight (BW) = 412.5 ± 53.68 kg] were randomly assigned to either a basal diet targeting BW gains of 0.45 kg•heifer-1•d-1(CON; n = 14) or the basal diet plus 113 g•heifer-1•d-1of a vitamin/mineral supplement (VTM; n = 17). Heifers remained on their respective dietary treatments until calving. After calving, all F1 heifer calves were raised in a single management group with their dams until weaning (BW = 209 ± 4.82 kg; VTM, n = 17; CON, n = 12) and fed a common diet throughout postnatal development. At breeding and throughout gestation, F1 heifers (n = 9, VTM; n = 7, CON) were allotted daily feed intakes of 1.5% of BW on a dry-matter basis as a total mixed ration and used to evaluate cellular energy metabolism throughout pregnancy. Liver and Longissimus dorsi muscle biopsies were collected on d 179 and d 247 +/- 3 of gestation and mitochondrial function was assessed via high resolution respirometry (Oroboros Instruments, Innsbruck, Austria). The following respiratory states were evaluated: LEAK respiration (L), OXPHOS capacity (P), NADH-linked OXPHOS (PI), and electron transfer capacity (E). Data were analyzed using the MIXED procedure of SAS with repeated measures where appropriate. No treatment × trimester interaction (P ≥ 0.13) was observed for any of the respiratory states in liver and muscle. Hepatic oxygen consumption was not influenced by maternal gestational VTM supplementation (P ≥ 0.68), or stage of gestation (P ≥ 0.27). In muscle, L respiration was the only state affected by maternal dietary treatments, being greater (P = 0.05) in CON than VTM heifers. Additionally, L respiration was greater (P = 0.02) during the third trimester compared with the second trimester. This observation in CON heifers is important because increased L respiration (proton leak) results in decreased ATP production. Protons that escape the intermembrane space, are dissipated as heat rather than be used for ATP synthesis; thus, oxygen consumption increases to compensate for the reduction of protons entering ATP turnover. Results show increased muscle mitochondria inefficiency in offspring with dams lacking supplementation during pregnancy. The increased incidence of proton leak results in potentially less efficient cattle as protons escape the electron transport chain rather than be transformed for energy utilization need of the animal, thus VTM supplementation throughout pregnancy impacts fetal development with potential effects in live offspring 18 to 22 mo post-parturition.

Unlocking renal Restoration: Mesaconine from Aconitum plants restore mitochondrial function to halt cell apoptosis in acute kidney injury

Acute kidney injury (AKI) is characterized by a sudden decline in renal function. Traditional Chinese medicine has employed Fuzi for kidney diseases; however, concerns about neurotoxicity and cardiotoxicity have constrained its clinical use. This study explored mesaconine, derived from processed Fuzi, as a promising low-toxicity alternative for AKI treatment. In this study, we assessed the protective effects of mesaconine in gentamicin (GM)-induced NRK-52E cells and AKI rat models in vitro and in vivo, respectively. Mesaconine promotes the proliferation of damaged NRK-52E cells and down-regulates intracellular transforming growth factor β1 (TGF-β1) and kidney injury molecule 1 (KIM-1) to promote renal cell repair. Concurrently, mesaconine restored mitochondrial morphology and permeability transition pores, reversed the decrease in mitochondrial membrane potential, mitigated mitochondrial dysfunction, decreased ATP production, inhibited inflammatory factor release, and reduced early apoptosis rates. In vivo, GM-induced AKI rat models exhibited elevated AKI biomarkers, in which mesaconine was effectively reduced, indicating improved renal function. Mesaconine enhanced superoxide dismutase activity, reduced malondialdehyde content, alleviated inflammatory infiltrate, mitigated tubular and glomerular lesions, and downregulated NF-κB (nuclear factor-κb) p65 expression, leading to decreased tumor necrosis factor-α (TNF-α) and IL-1β (interleukin-1β) levels in GM-induced AKI animals. Furthermore, mesaconine inhibited the expression of renal pro-apoptotic proteins (Bax, cytochrome c, cleaved-caspase 9, and cleaved-caspase 3) and induced the release of the anti-apoptotic protein bcl-2, further suppressing apoptosis. This study highlighted the therapeutic potential of mesaconine in GM-induced AKI. Its multifaceted mechanisms, including the restoration of mitochondrial dysfunction, anti-inflammatory and antioxidant effects, and apoptosis mitigation, make mesaconine a promising candidate for further exploration in AKI management.

Mitochondrial-dependent oxidative phosphorylation is key for postnatal metabolic adaptation of alveolar macrophages in the lung

Alveolar macrophages (AMs) seed in lung during embryogenesis and become mature in perinatal period. Establishment of acclimatization to environmental challenges is important, whereas the detailed mechanisms that drive metabolic adaptation of AMs remains to be elucidated. Here, we showed that energy metabolism of AMs was transformed from glycolysis prenatally to oxidative phosphorylation (OXPHOS) postnatally accompanied by up-regulated expression of mitochondrial transcription factor A (TFAM). TFAM deficiency disturbed mitochondrial stability and decreased OXPHOS, which finally impaired AM maintenance and function, but not AM embryonic development. Mechanistically, Tfam-deletion resulted in impaired mitochondrial respiration and decreased ATP production, which triggered endoplasmic reticulum (ER) stress to cause B cell lymphoma 2 ovarian killer (BOK) accumulation and abnormal distribution of intracellular Ca2+, eventually led to induce AM apoptotic death. Thus, our data illustrated mitochondrial-dependent OXPHOS played a key role in orchestrating AM postnatal metabolic adaptation.