PGC-1α mRNA Expression Research Articles

Phenotypic characteristics of adipocyte-like cells generated from C2C12 myoblasts cultured with chicken serum

The aim of this study was to clarify the transcriptional and metabolic characteristics of C2C12 myoblasts cultured in Dulbecco’s Modified Eagle Medium (DMEM) containing 20% chicken serum (CHS) (C2C12-CHS cells) compared with C2C12 myoblasts cultured in DMEM containing 20% fetal bovine serum (FBS) (C2C12-FBS cells). After 3 days of culture, C2C12-CHS cells showed a marked accumulation of lipid droplets, accompanied by increased expression levels of brown adipocyte-related genes (i.e., Bmp7, Prdm16, Ucp1, Cidea, Pgc1α, Cox7a1, Cox8, and β3-adorenoceptor). Furthermore, stimulation of β3-adorenoceptor by its selective agonist, mirabegron, increased the mRNA expression of Ucp1 and Pgc1α in C2C12-CHS cells. Wide-targeted metabolomic analysis performed by gas chromatography-tandem mass spectrometry revealed that the metabolic profile of C2C12-CHS cells was obviously different to that of C2C12-FBS cells. Additionally, the metabolomic analysis indicated that β3-adrenoceptor stimulation by mirabegron upregulated energy metabolism in C2C12-CHS cells as seen in brown adipocytes. These results suggest that C2C12-CHS cells may differentiate into brown adipocyte-like cells, accompanied by increased functional β3-adrenoceptor.

Impact of exercise and fasting on mitochondrial regulators in human muscle

Abstract Objectives To investigate the impact of acute energetic stress (acute HIIE and fasting) on ERRγ, PPARβ, NR1D1, NR4A1, and TFEB in human skeletal muscle. Methods The current study performed secondary analyses using muscle biopsy samples from two previously published studies: study 1) leg muscle biopsies from nine men and eight women were obtained pre and 3 h following acute high-intensity interval cycling exercise (HIIE); study 2) leg muscle biopsies were obtained from nine men pre-, during, and post-an 8 h fast with or without 2 h of arm ergometer exercise. RT-PCR was performed on samples from each study to determine the mRNA expression of ERRγ, PPARβ, NR1D1, NR4A1, and TFEB. Additionally, we retrieved data from meta-analyzed human muscle gene expression using the publicly available database MetaMex. Results PGC-1α (p<0.01, d=1.98) and NR4A1 (p<0.01, d=1.36) mRNA expression significantly increased while TFEB (p≤0.05, d=0.70) decreased following HIIE. Significant decreases in NR4A1 and NR1D1 mRNA expression were observed following an 8 h fast. Our MetaMex analyses revealed significant increases (p<0.05) in PGC-1α and NR4A1 expression following aerobic and resistance exercise, and in PPARβ expression following resistance exercise. Conclusions Our data indicate that acute HIIE stimulates increases in NR4A1 and PGC-1α and decreases in TFEB mRNA expression in human skeletal muscle. Additionally, a short term (8 h) fast reduced the mRNA expression of the transcriptional regulators NR4A1 and NR1D1 – potentially as a mechanism of decreasing mitochondrial biogenesis to reduce energy expenditure during a period of restricted energy availability.

Berberine Attenuates Acetamiprid Exposure-Induced Mitochondrial Dysfunction and Apoptosis in Rats via Regulating the Antioxidant Defense System.

Acetamiprid (ACMP) is a neonicotinoid insecticide that poses a significant threat to the environment and mankind. Oxidative stress and mitochondrial dysfunction are considered prime contributors to ACMP-induced toxic effects. Meanwhile, berberine (BBR) a natural plant alkaloid, is a topic of interest because of its therapeutic and prophylactic actions. Therefore, this study evaluated the effects of BBR on ACMP-mediated alterations in mitochondrial functions and apoptosis in rat liver tissue. Male Wistar rats were divided into four groups: (I) control, (II) BBR-treated, (III) ACMP-exposed, and (IV) BBR+ACMP co-treated groups. The doses of BBR (150 mg/kg b.wt) and ACMP (1/10 of LD50, i.e., 21.7 mg/kg b.wt) were given intragastrically for 21 consecutive days. The results showed that the administration of ACMP diminished mitochondrial complex activity, downregulated complex I (ND1 and ND2) and complex IV (COX1 and COX4) subunit mRNA expression, depleted the antioxidant defense system, and induced apoptosis in rat liver. BBR pre-treatment significantly attenuated ACMP-induced mitochondrial dysfunction by maintaining mitochondrial complex activity and upregulating ND1, ND2, COX1, and COX4 mRNA expression. BBR reversed ACMP-mediated apoptosis by diminishing Bax and caspase-3 and increasing the Bcl-2 protein level. BBR also improved the mitochondrial antioxidant defense system by upregulating mRNA expression of PGC-1α, MnSOD, and UCP-2 in rat liver tissue. This study is the first to evaluate the protective potential of BBR against pesticide-induced mitochondrial dysfunction in liver tissue. In conclusion, BBR offers protection against ACMP-induced impairment in mitochondrial functions by maintaining the antioxidant level and modulating the apoptotic cascade.

Empagliflozin impact on experimentally induced acetaminophen toxicity: Imprint of mitochondrial dynamics, biogenesis, and cGAS/STING signal in amending liver insult.

Acetaminophen (APAP) is one of the most clinically relevant medications associated with acute liver damage. A prolific deal of research validated the hepatoprotective effect of empagliflozin (EMPA); however, its effect on APAP-induced hepatotoxicity has still not been investigated. In this study, the prospective hepatoprotective impact of EMPA against APAP-induced hepatotoxicity was investigated. Twenty-eight Balb-C mice were assigned to four groups: control, APAP, EMPA10/APAP, and EMPA25/APAP. At the end of the experiment, serum hepatotoxicity biomarkers, MDA level, and GSH content were estimated. Hepatic mitofusin-2 (MFN2), optic atrophy 1 (OPA1), dynamin-related protein 1 (Drp1), and mitochondrial fission 1 protein (FIS1) were immunoassayed. PGC-1α, cGAS, and STING mRNA expression were assessed by real-time PCR. Histopathological changes and immunohistochemistry of INF-β, p-NF-κB, and iNOS were evaluated. APAP treatment caused significant hepatic functional impairment and increased hepatic MDA levels, as well as a concomitant decrease in GSH content. Marked elevation in Drp1 and FIS1 levels, INF-ß, p-NF-κB, and iNOS immunoreactivity, and reduction in MFN2 and OPA1 levels in the APAP-injected group, PGC-1α downregulation, and high expression of cGAS and STING were also documented. EMPA effectively ameliorated APAP-generated structural and functional changes in the liver, restored redox homeostasis and mitochondrial dynamics balance, and enhanced mitochondrial biogenesis, remarkably diminished hepatic expression of cGAS and STING, and elicited a reduction in hepatic inflammation. Moreover, the computational modeling data support the interaction of APAP with antioxidant system-related proteins as well as the interactions of EMPA against Drp1, cGAS, IKKA, and iNOS proteins. Our findings demonstrated for the first time that EMPA has an ameliorative impact against APAP-induced hepatotoxicity in mice via modulation of mitochondrial dynamics, biogenesis, and cGAS/STING-dependent inflammation. Thus, this study concluded that EMPA could be a promising therapeutic modality for acute liver toxicity.

Hepatoprotective effects and mechanisms of l-theanine and epigallocatechin gallate combined intervention in alcoholic fatty liver rats.

Chronic excessive alcohol consumption can lead to alcoholic fatty liver, posing substantial health risks. l-Theanine (LTA) and epigallocatechin gallate (EGCG) in tea exert antioxidant and hepatoprotective effects. However, the combined effects of LTA and EGCG on rats with alcoholic fatty liver, and the underlying mechanisms of such effects, remain unclear. In this study, Sprague Dawley (SD) rats were fed with alcohol for 6 weeks to induce alcoholic fatty liver. Subsequently, for another 6 weeks, the rats were administered LTA (200 mg kg-1 day-1), EGCG (200 mg kg-1 day-1), or a combination of LTA with EGCG (40 mg kg-1 day-1 l-Thea +160 mg kg-1 day-1 EGCG), respectively. The combined use of LTA and EGCG for alcoholic fatty liver disease had more significant effects than their individual administration. This combination reduced the activity of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) as well as the levels of hepatic triglyceride (TG), malondialdehyde (MDA), and reactive oxygen species (ROS) in the rats. The combined intervention also increased hepatic superoxide dismutase (SOD) and glutathione peroxidase activity. Reductions in hepatic fat accumulation and inflammatory responses were observed. The mechanism underlying these effects primarily involved the inhibition of fatty acid synthesis and the alleviation of lipid peroxidation through the downregulation of the mRNA and protein expression of TNF-α, SREBP1c, and CYP2E1 and the upregulation of the mRNA and protein expression of ADH1, ALDH2, Lipin-1, PPARαPPARα, AMPK, and PGC-1α, thereby promoting the oxidative decomposition of fatty acids and reducing the synthesis of cholesterol and glucose. l-Theanine and EGCG appear to be able to alleviate alcoholic fatty liver by modulating lipid metabolism and ameliorating oxidative stress, indicating their potential as natural active ingredients in anti-alcoholic fatty liver food products. © 2024 Society of Chemical Industry.

Effect of Myristica fragrans on PGC1α and Synaptophysin Expression in Male Wistar Rats Hippocampus

Background: Nutmeg is an indigenous plant from Indonesia that has been used extensively in herbal treatment. Nutmeg seed extract (NuSE) contains the active compound macelignan, which exhibits pharmacological activities. A previous study stated that NuSE is PPARγ or peroxisome proliferator-activated receptor gamma agonist that potentially enhances synaptic signal modulation. PPARγ activation can activate PGC1α or peroxisome proliferator-activated receptor gamma coactivator-1 alpha as the primary regulator of mitochondrial biogenesis. Mitochondria are involved in synaptic transmission. Increased modulation of signals at synapses can increase neuroplasticity, potentially improving the brain's cognitive function, as seen by the amount of Synaptophysin in the synaptic vesicle membrane for evaluating synaptogenesis.Objective: This research demonstrates how nutmeg seed extract (NuSE) affects PGC1α and synaptophysin expression compared with DHA or docosahexanoieac acid, which has been evidenced to promote neurite growth.Methods: Twenty-four Wistar male rats aged eight weeks were divided into four groups (control, PGA group, NuSE group, and DHA group). The treatment group was administered for 12 weeks using a gavage. After that, the rats were sacrificed, and the hippocampus neurons were collected. The PGC1α and Synaptophysin mRNA expression was measured using semiquantitative reversed PCR, visualized with electrophoresis, and then quantified with ImageJ.Results: This study showed that NuSE increased synaptophysin and PGC1α mRNA expressions compared to the control group with significance statistic (p=0.017, p<0,05) in synaptophysin expression but did not increase PGC1α expression significantly (p=0.364, p>0,05).Conclusion: In conclusion, nutmeg seed extract (NuSE) impacts synaptogenesis in synaptophysin expression to modulate synaptic transmission.

Electrical Stimulation-Based Twitch Exercise Suppresses Progression of Immobilization-Induced Muscle Fibrosis via Downregulation of PGC-1α/VEGF Pathway

This study aimed to determine whether electrical stimulation-based twitch exercise is effective in inhibiting the progression of immobilization-induced muscle fibrosis. 19 Wistar rats were randomly divided into a control group (n=6), an immobilization group (n=6; with immobilization only), and a Belt group (n=7; with immobilization and twitch exercise through the belt electrode device, beginning 2 weeks after immobilization). The bilateral soleus muscles were harvested after the experimental period. The right soleus muscles were used for histological analysis, and the left soleus muscles were used for biochemical and molecular biological analysis. As a result, in the picrosirius red images, the perimysium and endomysium were thicker in both the immobilization and Belt groups compared to the control group. However, the perimysium and endomysium thickening were suppressed in the Belt group. The hydroxyproline content and α-SMA, TGF-β1, and HIF-1α mRNA expressions were significantly higher in the immobilization and belt groups than in the control group. These expressions were significantly lower in the Belt group than in the immobilization group. The capillary-to-myofiber ratio and the mRNA expressions of VEGF and PGC-1α were significantly lower in the immobilization and belt groups than in the control group, these were significantly higher in the Belt group than in the immobilization group. From these results, Electrical stimulation-based twitch exercise using the belt electrode device may prevent the progression of immobilization-induced muscle fibrosis caused by downregulating PGC-1α/VEGF pathway, we surmised that this intervention strategy might be effective against the progression of muscle contracture. Keywords: Immobilization • Skeletal muscle • Fibrosis • Electrical stimulation-based twitch exercise • PGC-1α/VEGF pathway

Tempol maintained the cellular integrity of the cerebellar cortex by preserving neuron survival, autophagy, glial cells, and synapses after cisplatin exposure

Backgroundtempol is a free radical scavenger that passes through the blood-brain barrier. This study aimed to assess its ameliorative role in the cerebellar cortex after cisplatin injection. Methodsthe examined forty-eight adult male wistar albino rats were divided into four groups. The saline group received 0.5 ml of normal saline, the tempol group was injected with 0.5 ml of tempol (100 mg/kg/day), the cisplatin group was injected with cisplatin single dose (7 mg/kg) on the 8th day, and cisplatin + tempol group received combined treatment. All groups were dosed through intraperitoneal injections. Resultshistological examination revealed meningeal congestion and thickening with excess collagen, discrete vacuolated cortical cells, with pyknotic nuclei, and tissue loss after cisplatin. Immunohistochemical expression of NF-kβ and GFAP were enhanced, while LC3-II and synaptophysin expression decreased with cisplatin. Cisplatin treatment reduced mRNA expression of NGF, GLP-1, BDNF, PGC1-α, and PPAR-α while it boosted Caspase-3 expression. Moreover, it tripled the level of MDA and lowered levels of SOD, CAT, and GSH in cerebellar tissue homogenate. Tempol supplementation restored the meningeal and the normal histological structure of the cerebellar cortex. The immunohistochemical as well as mRNA expressions of different genes were highly normalized but still showed variable significant differences when compared to the control except for NGF, PGC1-α, and Caspase-3 genes. Great restoration of biochemical markers was evident with tempol, especially for CAT that showed no significant difference in comparison with the saline group. Conclusiontempol cisplatin combination can enhance neuronal survival, promote autophagy, decrease astrogliosis, and preserve synapses.

The regulatory effects of electroacupuncture on type 2 innate lymphoid cell (ILC2) function and browning of white adipose tissue in obese rats: 电针通过调控ILC2功能和白色脂肪棕色化治疗肥胖大鼠的作用机制

ObjectiveTo observe the effects of electroacupuncture (EA) on type 2 innate lymphoid cell (ILC2) function in white adipose tissue (WAT) of high-fat diet (HFD)-induced obese rats to reveal the mechanism underlying weight loss. MethodsMale Winstar rats (n=15) were randomly divided into control, HFD, and HFD+EA groups, with five rats in each group. An obesity model was established by feeding rats with a HFD. EA (2 Hz, 1 mA) was applied to “Zhongwan (CV12)” bilateral “Tianshu (ST25)” “Zusanli (ST36)” and “Sanyinjiao (SP6)” for 15 min, 7 days a week, for a total of 5 weeks. During EA treatment, the HFD group was fed a HFD, whereas rats in the control group were maintained on a normal diet. There was no intervention in either the control or the HFD groups. Body weight was measured weekly. Full-field adipocyte morphology, adipocyte volume, and the number of abdominal WAT were observed under a microscope after sectioning and hematoxylin and eosin staining. The levels of IL-5 (interleukin-5), IL-13 (interleukin-13), IL-33 (interleukin-33), and ST2 (growth stimulating gene 2 protein) in the WAT were assayed using enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction (RT-PCR). The expression levels of browning markers including PGC1α（peroxisome proliferator-activated receptor gamma coactivator 1-alpha）, PPARγ (peroxisome proliferator-activated receptor gamma), PRDM16 (histone-lysine N-methyltransferase), and UCP1（uncoupling protein 1 in WAT were detected by western blot analysis and RT-PCR. ResultsAfter a 7-week induction period, rats in both the HFD and HFD+EA groups were 20% heavier than their initial weights before modeling (P<0.01, P<0.001). Following a 5-week EA intervention, the body mass and Lee index of obese rats were significantly reduced (P<0.05). The HE results showed that adipocytes in the HFD group displayed a significant increase in diameter and a decrease in number compared to the control group. However, in the HFD+EA group, white adipocytes exhibited reduced diameter and appeared more regular in shape. In the control group, the proportion of ILC2 was (86.53±2.55)%, whereas in the HFD group, it decreased to (73.62±2.52)%, indicating a significant reduction in ILC2 in the WAT of obese rats. Following EA treatment, the proportion of ILC2 was elevated to (80.54±4.25)%. This analysis revealed a significant decrease in the expression levels of IL-5, IL-13, IL-33, and ST2 in the WAT of obese rats in the HFD group; however, these levels increased after EA intervention. The mRNA levels of PPARγ, PGC1α, PRDM16, and protein levels of UCP1 were decreased in the HFD group (P<0.01, P<0.05, and P<0.001), and the trends were significantly reversed with EA manipulation (P<0.05). RT-PCR and western blotting results revealed that EA remarkably upregulated the mRNA expression of PGC1α, PPARγ, and PRDM16, as well as the protein expression of UCP1 induced by HFD. In the HFD group, PRDM16 expression showed a strong correlation with UCP1 expression, and ILCs were strongly correlated with PGC1α expression. However, these strong correlations did not occur in HFD+EA group. Following EA treatment, the expression of PPARγ displayed a strong correlation with ILC2s, indicating that the altered ILC2 proportion was closely related to browning in WAT. ConclusionEA treatment effectively alleviated obesity by restoring ILC2 function and promoting browning of white adipocytes. ILC2s may play an important role in the effects of EA treatment, but this requires further study.

Lactobacillus paracasei JY062 Alleviates Glucolipid Metabolism Disorders via the Adipoinsular Axis and Gut Microbiota.

Glycolipid metabolic disorders (GLMD) refer to a series of metabolic disorders caused by abnormal processes of glucose and lipid synthesis, decomposition, and absorption in the body, leading to glucose and lipid excess, insulin resistance, and obesity. Probiotic intervention is a new strategy to alleviate metabolic syndrome. Lactobacillus paracasei JY062 (L. paracasei JY062) was separated from the Tibet-fermented dairy products. The results demonstrated a strong ability to relieve blood glucose disorders, blood lipid disorders, and tissue damage. The LPH group had the best effect, significantly decreasing the total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), leptin, insulin, and free fatty acid (FFA) concentrations and increasing the high-density lipoprotein cholesterol, adiponectin, and GLP-1 level compared to HFD-group mice. L. paracasei JY062 could activate the APN-AMPK pathway, increased AdipoQ, AMPK GLUT-4, and PGC-1α mRNA expression and decreased SREBP-1c, ACC, and FAS mRNA expression. L. paracasei JY062 intervention decreased the relative abundance of harmful bacteria, increased the relative abundance of beneficial bacteria, and restored the imbalance of gut microbiota homeostasis caused by a high-glucose-fat diet. L. paracasei JY062 alleviated glucolipid metabolism disorders via the adipoinsular axis and gut microbiota. This study provided a theoretical basis for probiotics to ameliorate glucolipid metabolism disorders by regulating the adipoinsular axis.

Effects of phosphorus and fenofibrate on lipid deposition, mitochondrial function and protein synthesis in obscure puffer (Takifugu obscurus)

This study aimed to investigate the effects of phosphorus (P) restriction and fenofibrate (F) on lipid deposition, mitochondrial function and protein synthesis in obscure puffer using in vivo and in vitro studies. In vivo, healthy fish with an initial body weight of 18.21 ± 0.04 g were fed three diets supplemented with different P and fenofibrate contents for 10 weeks: Control (5.3 g/kg P), P0 (0 g/kg P) and P0 + F (0 g/kg P and 3.5 g/kg F). The results indicated that P0 treatment significantly reduced weight gain rate and protein deposition, but increased body lipid accumulation, hepatic lipid droplets and serum triglyceride and cholesterol content (P < 0.05). However, P0 + F treatment reversed these. Furthermore, P0 treatment was found to inhibit the mRNA levels of pparα, lpl and cyp7a1, whereas P0 + F treatment significantly increased the expression levels of these genes. In vitro, primary hepatocytes were cultured for 48 h in three different culture media: Control (normal DMEM medium), P0 (DMEM without P), and P0 + F (DMEM without P + 200 mM F). The results showed that P0 significantly decreased the mRNA and protein expression levels of Pparα (P < 0.05), and P0 + F up-regulated mRNA expression levels of pparα compared with P0 group (P < 0.05). Furthermore, P0 inhibited the expression levels of genes associated with fatty acid β-oxidation (cpt1 and acox1) and transport (cd36), but elevated the expression levels of genes related to lipid synthesis (fas, me, g6pd and dgat1) and cholesterol synthesis (hmgcr) (P < 0.05). However, P0 + F reversed these effects. P0 decreased mitochondrial abundance, membrane potential and ATP content, increased the mRNA expression level of ampk and 4epb1 and inhibited the mRNA expression of pgc1-α and the protein expression of mTOR and S6k (P < 0.05), whereas P0 + F increased mitochondrial abundance and membrane potential, increased mtor mRNA expression and inhibited 4ebp1 mRNA expression. Overall, this study suggests that P deficiency leads to lipid and cholesterol accumulation and impaired growth in fish, and fenofibrate can alleviate these effects by improving lipid and cholesterol metabolism, mitochondrial function, and protein synthesis.

Melatonin enhances captopril mediated cardioprotective effects and improves mitochondrial dynamics in male Wistar rats with chronic heart failure

Mitochondrial dysfunction is a recent emerging research scope that proved to be involved in many cardiovascular diseases culminating in chronic heart failure (CHF), which remains one of the primary causes of morbidity and mortality. This study investigated the added cardio-protective effects of exogenous melatonin administration to conventional captopril therapy in isoproterenol (ISO) exposed rats with CHF. Five groups of Wistar rats were recruited; (I): Control group, (II): (ISO group), (III): (ISO + captopril group), (IV): (ISO + melatonin group) and (V): (ISO + melatonin/captopril group). Cardiac function parameters and some oxidant, inflammatory and fibrotic markers were investigated. Moreover; mRNA expression of mitochondrial mitophagy [parkin & PTEN induced kinase 1 (PINK1)], biogenesis [Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)], fusion [mitofusin 2 (Mfn2)] and fission [dynamin-related protein 1 (DRP-1)] parameters in rat’s myocardium were evaluated. Rats’ myocardium was histo-pathologically and immunohistochemically evaluated for Beclin1 and Sirt3 expression. The present study revealed that captopril and melatonin ameliorated cardiac injury, oxidative stress biomarkers, and pro-inflammatory cytokines in ISO-exposed rats. These protective effects could be attributed to mitochondrial dynamic proteins control (i.e. enhanced the mRNA expression of parkin, PINK1, PGC-1α and Mfn2, while reduced DRP-1 mRNA expression). Also, Beclin1 and Sirt3 cardiac immunoreactivity were improved. Combined captopril and melatonin therapy showed a better response than either agent alone. Melatonin enhanced myocardial mitochondrial dynamics and Sirt3 expression in CHF rats and may represent a promising upcoming therapy added to conventional heart failure treatment.

Butyrate reduces adherent-invasive E. coli-evoked disruption of epithelial mitochondrial morphology and barrier function: involvement of free fatty acid receptor 3

ABSTRACT Gut bacteria provide benefits to the host and have been implicated in inflammatory bowel disease (IBD), where adherent-invasive E. coli (AIEC) pathobionts (e.g., strain LF82) are associated with Crohn’s disease. E. coli-LF82 causes fragmentation of the epithelial mitochondrial network, leading to increased epithelial permeability. We hypothesized that butyrate would limit the epithelial mitochondrial disruption caused by E. coli-LF82. Human colonic organoids and the T84 epithelial cell line infected with E. coli-LF82 (MOI = 100, 4 h) showed a significant increase in mitochondrial network fission that was reduced by butyrate (10 mM) co-treatment. Butyrate reduced the loss of mitochondrial membrane potential caused by E. coli-LF82 and increased expression of PGC-1 α mRNA, the master regulator of mitochondrial biogenesis. Metabolomics revealed that butyrate significantly altered E. coli-LF82 central carbon metabolism leading to diminished glucose uptake and increased succinate secretion. Correlating with preservation of mitochondrial network form/function, butyrate reduced E. coli-LF82 transcytosis across T84-cell monolayers. The use of the G-protein inhibitor, pertussis toxin, implicated GPCR signaling as critical to the effect of butyrate, and the free fatty acid receptor three (FFAR3, GPR41) agonist, AR420626, reproduced butyrate’s effect in terms of ameliorating the loss of barrier function and reducing the mitochondrial fragmentation observed in E. coli-LF82 infected T84-cells and organoids. These data indicate that butyrate helps maintain epithelial mitochondrial form/function when challenged by E. coli-LF82 and that this occurs, at least in part, via FFAR3. Thus, loss of butyrate-producing bacteria in IBD in the context of pathobionts would contribute to loss of epithelial mitochondrial and barrier functions that could evoke disease and/or exaggerate a low-grade inflammation.

Regulation of PGC-1α of the Mitochondrial Energy Metabolism Pathway in the Gills of Indian Medaka (Oryzias dancena) under Hypothermal Stress.

Ectothermic fish exposure to hypothermal stress requires adjusting their metabolic molecular machinery, which was investigated using Indian medaka (Oryzias dancena; 10 weeks old, 2.5 ± 0.5 cm) cultured in fresh water (FW) and seawater (SW; 35‱) at room temperature (28 ± 1 °C). The fish were fed twice a day, once in the morning and once in the evening, and the photoperiod was 12 h:12 h light: dark. In this study, we applied two hypothermal treatments to reveal the mechanisms of energy metabolism via pgc-1α regulation in the gills of Indian medaka; cold-stress (18 °C) and cold-tolerance (extreme cold; 15 °C). The branchial ATP content was significantly higher in the cold-stress group, but not in the cold-tolerance group. In FW- and SW-acclimated medaka, the expression of genes related to mitochondrial energy metabolism, including pgc-1α, prc, Nrf2, tfam, and nd5, was analyzed to illustrate differential responses of mitochondrial energy metabolism to cold-stress and cold-tolerance environments. When exposed to cold-stress, the relative mRNA expression of pgc-1α, prc, and Nrf2 increased from 2 h, whereas that of tfam and nd5 increased significantly from 168 h. When exposed to a cold-tolerant environment, prc was significantly upregulated at 2 h post-cooling in the FW and SW groups, and pgc-1α was significantly upregulated at 2 and 12 h post-cooling in the FW group, while tfam and nd5 were downregulated in both FW and SW fish. Hierarchical clustering revealed gene interactions in the cold-stress group, which promoted diverse mitochondrial energy adaptations, causing an increase in ATP production. However, the cold-tolerant group demonstrated limitations in enhancing ATP levels through mitochondrial regulation via the PGC-1α energy metabolism pathway. These findings suggest that ectothermic fish may develop varying degrees of thermal tolerance over time in response to climate change. This study provides insights into the complex ways in which fish adjust their metabolism when exposed to cold stress, contributing to our knowledge of how they adapt.

Docosahexaenoic acid (DHA) alleviates hepatic lipid accumulation by regulating mitochondrial quality control through ERK signaling pathway in grass carp (Ctenopharyngodon idellus)

Docosahexaenoic acid (DHA) alleviates hepatic lipid accumulation in fish, but the underlying mechanism remains unclear. Studies in mammals showed that promoting fatty acid (FA) β-oxidation, which mainly occurs in mitochondrion, improves lipid accumulation. This study aims to investigate the effect of DHA on fatty acid (FA) β-oxidation, focusing on the role of hepatic mitochondrial quality control (MQC) and mitochondrial function, in grass carp (Ctenopharyngodon idellus) in vivo and in vitro. Grass carps (41.87 ± 0.08 g) were fed with diets supplemented with 0% (control) and 1% DHA for 8 weeks. Dietary 1% DHA markedly decreased the hepatosomatic index, hepatic triglyceride (TG) content, and serum TG (P < 0.05). Dietary 1% DHA significantly increased pparα and cpt1 mRNAs, which implies the activated FA β-oxidation. In addition, dietary 1% DHA improved mitochondrial function by increasing the ATP content and antioxidant ability. The mRNAs encoding DRP1, OPA1, MFN1 and MFN2 were significantly increased by DHA (P < 0.05), suggesting that mitochondrial division and fusion were activated simultaneously. Transmission electron microscopy displayed that dietary 1% DHA triggers the increase of mitochondria. Along with this, mitochondrial DNA copy numbers and the mRNA expression of pgc1α, tfam and nrf1 were significantly increased in 1% DHA group (P < 0.05), suggesting that DHA activated mitochondrial biogenesis. BNIP3/NIX-dependent mitophagy was also induced by DHA. Consistent with these in vivo results, DHA restored the loss of ATP content, mitochondrial membrane potential, and antioxidant ability in palmitic acid (PA)-treated hepatocytes in vitro, implying that DHA improved the MQC network damaged by PA. DHA further activated FA β-oxidation and inhibited lipid accumulation in the hepatocytes. Importantly, U0126, an inhibitor of ERK, abrogated the effects of DHA on the MQC network and lipid metabolism. Taken together, the present study demonstrated that the alleviation of hepatic lipid accumulation by DHA is mediated by the activation of FA β-oxidation and improvement of MQC via the ERK pathway. This study may shed light on the molecular mechanism underlying DHA's function in relieving hepatic lipid deposition in vertebrates.

Efficacy of creatine nitrate supplementation on redox status and mitochondrial function in pectoralis major muscle of preslaughter transported broilers

This study was purposed to investigate the efficacy of dietary creatine nitrate (CrN) supplementation on redox status and mitochondrial function in pectoralis major (PM) muscle of broilers that experienced preslaughter transport. A total of 288 Arbor Acres broilers (28-day-old) were randomly assigned into five dietary treatments, including a basal diet or the basal diet supplemented with 600 mg/kg guanidinoacetic acid (GAA), 300, 600, or 900 mg/kg CrN for 14 days, respectively. On the transportation day, the basal diet group was divided into two groups on average, resulting in six groups. The control group was transported for 0.5 h and the other groups for 3 h (identified as Control, T3h, GAA600, CrN300, CrN600, and CrN900 group, respectively), and all crates were randomly placed on the truck travelling at an average speed of 80 km/h. Our results showed that GAA600 and CrN treatments decreased the muscle ROS level and MDA content (P < 0.05) and increased the mitochondrial membrane potential (P < 0.001), as well as a higher mRNA expression of avUCP (P < 0.001) and lower mRNA expressions of Nrf2 (P < 0.001), Nrf2 and PGC-1α (P < 0.05) compared with T3h group. Meanwhile, the mRNA and protein expressions of Nrf1, TFAM, and PGC-1α in CrN600 and CrN900 groups were lower than those in the T3h group (P < 0.05). Conclusively, dietary supplementation with GAA and CrN decreased muscle oxidative products and enhanced mitochondrial uncoupling mechanism and mtDNA copy number, which relieved muscle oxidative damage and maintained mitochondrial function.

Oridonin ameliorates doxorubicin induced-cardiotoxicity via the E2F1/Sirt6/PGC1α pathway in mice

Doxorubicin induced cardiotoxicity (DIC) arises from mitochondrial dysfunction and oxidative stress. Oridonin (Ori), a natural tetracycline diterpenoid, has shown cardiac protective effect; however, its role in DIC remains unclear. This study investigates the protective effect of Ori against DIC and elucidates its underlying molecular mechanisms. The results demonstrate that Ori significantly alleviated DIC by improving myocardial structure, reducing the proportion of apoptotic cells, and alleviating the myocardial oxidative damage and mitochondrial dysfunction both in vivo and in vitro. Doxorubicin significantly decreased Sirt6 and PGC1α levels in cardiac tissues, which was reversed by Ori. Furthermore, Sirt6 overexpression significantly improved myocardial structure and reduced the proportion of apoptotic cells by reducing oxidative stress and improving mitochondrial function. The protective effect of Ori is neutralized by the Sirt6 inhibitor OSS_128167, evidenced by downregulated mRNA and protein expression of PGC1α. The transcription factor E2F1 was upregulated by doxorubicin, leading to decreased Sirt6 expression-an effect mitigated by Ori. Molecular docking simulations indicate direct binding between Ori and specific amino acid residues on E2F1 through hydroxyl bonds. These findings uncover a novel mechanism whereby Ori attenuates DIC by modulating the E2F1/Sirt6/PGC1α pathway.

#3828 KINETICS OF THE DE NOVO NAD/NADH PATHWAY FROM AKI TO CKD

Abstract Background and Aims Mitochondrial dysfunction and energy metabolism deficiency are part of the acute kidney injury (AKI) pathophysiology. In particular, recent studies highlighted the role of nicotinamide adenine dinucleotide (NAD) production in the pathogenesis of AKI. NAD is an electron carrier for mitochondria and a cofactor for cytoplasmic redox reactions. Its production is decreased during AKI following a decreased of the expression of PGC1α (Peroxisome proliferator activated receptor gamma co-activator-1-α). PGC1α inactivation worsened and its overexpression prevented renal injury in a mouse model of renal ischemia. It was also shown that the consequences of PGC1α decreased expression included the alteration of the de novo NAD+ synthesis pathway. This was due to a reduction in the expression of the Quinolinate PhosphoRibosylTransferase (QPRT), which led to an accumulation of quinolinate. Consequently, the quinolinate/tryptophane (uQ/T) ratio increased in the urine. The modulation of this de novo has been studied mainly in the acute phase immediately following the injury. However its evolution with degree of severity and during the transition from AKI to CKD has not been described yet. In order to answer these questions, we designed the following studies: (1) A “severity” study in which we provoked ischemic AKI of increasing intensity in mice and quantified kidney PGC1alpha and QPRT mRNA expression. (2) An “AKI to CKD” study in which we followed kidney PGC1alpha and QPRT mRNA expression and uQ/T. Method Renal ischemia-reperfusion was performed in C57Bl6/J male mice using the new vascular occluder we recently developed (RIRI clamp), after nephrectomy of the contralateral kidney. For the ‘severity’ study, a 5–30 minutes ischemia was performed. Renal function (measurement of plasma creatinine and urea) and structure (Periodic Acid Schiff staining) were assessed 24h after ischemia. For the ‘AKI to CKD’ study, renal ischemia was performed during 10 minutes. Mice were sacrificed 1, 2, 3, 6 and 28 days after ischemia. For both studies, PGC1α and QPRT mRNA expression was quantified by qPCR in the kidneys. Urinary Q/T was determined by mass spectrometry. Results PGC1α and QPRT mRNA expression is inversely corrected to the AKI severity We induced AKI in mice by unilateral ischemia reperfusion injury of increasing time to induce several degrees of AKI severity. The measurement of plasma urea and creatinine concentration confirmed that the severity increased with the duration of ischemia. PGC1α and QPRT mRNA expression decreased progressively with ischemia severity until reaching a plateau at 15 minutes of ischemia for PGC1α (Fig. 1A), like plasma creatinine and urea, whereas QPRT (Fig. 1B) decreased is linear until 30 min of ischemia. PGC1α mRNA decrease is also inversely correlated to kidney dysfunction (p&amp;lt;0.001) (Figue 1C). PGC1α and QPRT expression recovery after AKI A 10-minute ischemia led to the development of Chronic Kidney Disease (CKD), as evidenced by an incomplete recuperation of the kidney function at 28 days. QPRT and PGC1α mRNA expression showed a progressive but incomplete recuperation during the transition from AKI to CKD compared to sham mice (Fig. 1D, E). uQ/T increases after ischemia and is restored during transition from AKI to CKD (Fig. 1F). Conclusion In addition to confirming the decrease of PGCα and QPRT mRNA expression during AKI, we show that it is correlated to the severity of the ischemic AKI. Furthermore, we describe the recovery during renal repair and transition to CKD.

Dihydroartemisinin alleviates mitochondrial damage and improves cardiomyocyte pyroptosis and ferroptosis through Sirt1-mediated PGC-1α

This study assesses the effect of dihydroartemisinin on pyroptosis and ferroptosis. Rat H9C2 cardiomyocytes were intervened with 35 mmol/L high glucose through assigned blank control, dihydro artemisinin, and dihydroartemisinin+Sirt1 groups. Confocal microscopy was used to observe the ROS levels, while proliferation ability was detected by CCK-8 method, and apoptosis was assessed by flow cytometry, and migration ability by Transwell transfer method. Moreover, analysis of pyroptosis-related factors expression and content of lipid peroxide were done using laser confocal microscopy. The average fluorescence intensity of dihydro artemisinin group and dihydroartemisinin+SIRT 1 group decreased significantly (P &lt;0.05), among which the dihydroartemisinin+SIRT 1 group had lowest average fluorescence intensity (P &lt;0.05). SIRT 1 level in the dihydroartemisinin and dihydroartemisinin+SIRT 1 groups was higher than blank control (P &lt;0.05), with highest level in the dihydroartemisinin+SIRT 1 group (P &lt;0.05). Cell proliferation in the dihydroartemisinin and dihydroartemisinin+SIRT 1 group was reduced (P &lt;0.05), with lowest proliferation in combination group (P &lt; 0.05). Cell migration in the dihydroartemisinin and dihydroartemisinin+SIRT 1 groups was reduced (P &lt;0.05), with lowest number of migratory cells in the dihydroartemisinin+SIRT 1 group (P &lt;0.05). Cell apoptosis in the dihydroartemisinin and dihydroartemisinin+SIRT 1 groups was increased (P &lt;0.05), with lowest apoptosis in the dihydroartemisinin+SIRT 1 group (P &lt;0.05). There was upregulation of SIRT 1 and PGC-1α mRNA expression in the dihydroartemisinin and dihydroartemisinin+SIRT 1 groups was elevated (P &lt;0.05). The expression of NLRP3, GSDMD, and Caspase-1 were all decreased (P &lt;0.05), while that of GPX4 was increased (P &lt;0.05). Dihydroartemisinin inhibits the function of H9C2 cardiomyocytes, pyroptosis and ferroptosis, playing a positive role in ameliorating Diabetic cardiomyopathy (DCM).

Lipid nanoparticle delivery of siRNA targeting Cyp2e1 gene attenuates subacute alcoholic liver injury in mice.

To investigate the effect and mechanism of lipid nanoparticle (LNP) delivery of small interfering RNA (siRNA) targeting Cyp2e1 gene on subacute alcoholic liver injury in mice. siRNA targeting Cyp2e1 gene was encapsulated in LNP (si-Cyp2e1 LNP) by microfluidic technique and the resulting LNPs were characterized. The optimal dose of si-Cyp2e1 LNP administration was screened. Forty female C57BL/6N mice were randomly divided into blank control group, model control group, si-Cyp2e1 LNP group, LNP control group and metadoxine group. The subacute alcoholic liver injury mouse model was induced by ethanol feeding for 10 d plus ethanol gavage for the last 3 d. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, and the superoxide dismutase (SOD) activity as well as malondialdehyde, reactive oxygen species, glutathione, triacylglycerol, total cholesterol contents in liver tissue were measured in each group, and liver index was calculated. The expression of genes related to oxidative stress, lipid synthesis and inflammation in each group of mice were measured by realtime RT-PCR. Compared with the model control group, the levels of liver index, serum ALT, AST activities, malondialdehyde, reactive oxygen species, triacylglycerol, total cholesterol contents in liver tissue decreased, but the SOD activity as well as glutathione increased in the si-Cyp2e1 LNP group (all P<0.01). Hematoxylin-eosin staining result showed disorganized hepatocytes with sparse cytoplasm and a large number of fat vacuoles and necrosis in the model control group, while the si-Cyp2e1 LNP group had uniformly sized and arranged hepatocytes with normal liver tissue morphology and structure. Oil red O staining result showed si-Cyp2e1 LNP group had lower fat content of the liver compared to the model control group (P<0.01), and no fat droplets accumulated. Anti-F4/80 monoclonal antibody fluorescence immunohistochemistry showed that the si-Cyp2e1 LNP group had lower cumulative optical density values compared to the model control group (P<0.01) and no significant inflammatory reaction. Compared with the model control group, the expression of catalytic genes P47phox, P67phox and Gp91phox were reduced (all P<0.01), while the expression of the antioxidant enzyme genes Sod1, Gsh-rd and Gsh-px were increased (all P<0.01). The mRNA expression of the lipid metabolism genes Pgc-1α and Cpt1 were increased (all P<0.01) and the lipid synthesis-related genes Srebp1c, Acc and Fasn were decreased (all P<0.01); the expression of liver inflammation-related genes Tgf-β, Tnf-α and Il-6 were decreased (all P<0.01). The si-Cyp2e1 LNP may attenuate subacute alcoholic liver injury in mice mainly by reducing reactive oxygen levels, increasing antioxidant activity, blocking oxidative stress pathways and reducing ethanol-induced steatosis and inflammation.