PGC-1α Expression Research Articles

Tanshinone I improves renal fibrosis by promoting gluconeogenesis through upregulation of peroxisome proliferator-activated receptor-γ coactivator 1α

Background Renal fibrosis, a hallmark of chronic kidney disease, is closely associated with dysregulated gluconeogenesis. Tanshinone I (Tan I), a bioactive compound derived from the traditional Chinese medicine Danshen, exhibits antifibrotic and anti-inflammatory properties. However, its effects on gluconeogenesis and the mechanisms through which it alleviates renal fibrosis remain unclear. This study aimed to investigate whether Tan I promotes gluconeogenesis and mitigates renal fibrosis. Methods Both in vivo and in vitro experiments were conducted. A unilateral ureteral obstruction (UUO) mouse model was used. Masson’s trichrome, HE, and immunofluorescence staining, along with Western blotting, were employed. Lactate concentrations and a pyruvate tolerance test were conducted to assess glucose metabolism. In vitro, HK2 cells and primary renal tubular cells were treated with transforming growth factor-β (TGFβ) to induce fibrosis, and the effects of Tan I on glucose and lactate levels were examined. Results In the UUO model, Tan I reduced fibrosis, decreased lactate accumulation, and modulated fibrosis markers while upregulating gluconeogenesis markers. Tanshinone I restored impaired renal gluconeogenesis, as evidenced by increased pyruvate levels. In vitro, Tan I inhibited fibrosis, reduced lactate levels, and increased glucose levels in cell supernatants. It also restored gluconeogenesis protein expression and decreased fibrotic protein levels. Peroxisome proliferator-activated receptor-γ coactivator (PGC1α) expression was downregulated in UUO and TGFβ-stimulated models, and Tan I reversed this downregulation. Inhibition of PGC1α in TGFβ-stimulated cells counteracted the antifibrotic and gluconeogenesis-promoting effects of Tan I. Conclusions Tanshinone I ameliorated renal fibrosis by enhancing gluconeogenesis through upregulation of PGC1α.

5'tiRNA-33-CysACA-1 promotes septic cardiomyopathy by targeting PGC-1α-mediated mitochondrial biogenesis

BackgroundWe revealed for the first time that the expression of 158 tRNA-derived small RNAs (tsRNAs) was altered in septic cardiomyopathy (SCM) by microarray analysis, and we selected 5'tiRNA-33-CysACA-1, which was the most significantly up-regulated, as a representative to explore the roles and mechanisms of tsRNAs in SCM. MethodsWe constructed a sepsis model by cecum ligation and puncture (CLP) in mice and detected the expression of 5'tiRNA-33-CysACA-1 using quantitative real-time PCR (qRT-PCR). The supernatant generated after LPS stimulation of macrophages was used as the conditional medium (CM) to stimulate H9C2 and established the injured cell model. CCK-8 and LDH release assays were used to detect cell viability and cell death. Mitochondrial membrane potential (MMP), ATP production, ROS production, and Mitotracker Red mitochondrial morphology were assayed to assess mitochondrial function. Expression of mRNA for molecules related to the mitochondrial quality control system was verified by qRT-PCR. The mechanism by which 5'tiRNA-33-CysACA-1 regulates peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) expression was examined by western blot, mRNA stability analysis, and rescue experiments. ResultsExpression of 5'tiRNA-33-CysACA-1 was elevated in cardiac tissue and H9C2 cells during septic myocardial injury. Stimulation of the CM resulted in cardiomyocyte injury and impaired mitochondrial function. Transfection of 5'tiRNA-33-CysACA-1 mimic in CM further downregulated PGC-1α expression, inhibited mitochondrial biogenesis thereby impairing mitochondrial function and leading to decreased cardiomyocyte activity and increased cell death. In contrast, transfection of the inhibitor ameliorated the above biological processes. In addition, mRNA stability assay and bioinformatics analysis showed that 5'tiRNA-33-CysACA-1 led to a decrease in the stability of PGC-1α mRNA, which in turn downregulated the expression of PGC-1α and promoted the development of SCM. Conclusions5'tiRNA-33-CysACA-1 expression is upregulated in SCM and inhibits mitochondrial biogenesis by targeting PGC-1α and decreasing the stability of PGC-1α mRNA, leading to mitochondrial dysfunction and promoting the development of SCM.

Silent Information Regulator 1/Peroxisome Proliferator-Activated Receptor-γ Coactivator-1α Axis: A Promising Target for Parkinson's and Alzheimer's Disease Therapies.

One of the key challenges in medical research is developing safe medications to treat neurodegenerative disorders. Increased oxidative stress, mitochondrial dysfunction, and neuroinflammation are common features of Alzheimer's disease (AD) and Parkinson's disease (PD). Silent information regulator 1 (SIRT-1), part of the sirtuin family, plays a critical role in various physiological processes by binding to histones and nonhistone proteins. SIRT-1 primarily mitigates oxidative stress and regulates mitochondrial activity by maintaining the deacetylated form of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), ensuring stable PGC-1α levels. Research has shown reduced SIRT-1/PGC-1α expression in AD and PD models. Targeting this pathway presents a promising therapeutic approach for managing AD and PD, potentially leading to disease-modifying treatments and improved outcomes. This review highlights the findings of various studies suggesting that the SIRT-1/PGC-1α pathway promotes mitochondrial biogenesis, synaptic plasticity, and cognitive function, as well as exerts antioxidant, anti-inflammatory, and anti-apoptotic effects, offering a potential method for AD and PD treatment.

Electroacupuncture combined with NSCs-Exo alters the response of hippocampal neurons in a chronic unpredictable mild stress paradigm in ovx rats

Electroacupuncture (EA) is a form of Traditional Chinese Medicine (TCM) that combines acupuncture with microcurrents mimicking the body's bioelectricity to prevent and treat diseases. Previous studies have demonstrated its antidepressant-like effects in chronic unpredictable mild stress (CUMS)-induced ovariectomy (OVX) rats. Neural stem cell-derived exosomes (NSCs-Exo) are heterogeneous and targeted, effectively promoting nerve regeneration and repairing neuronal damage, while potentially conveying the effects of EA. However, the precise mechanism remains unclear. In this study, perimenopausal depressive disorder (PDD) rat model were established using a two-step protocol CUMS + OVX. Treatment with EA combined with NSCs-Exo (EA-Exo) significantly improved depression-like behaviors in PDD rats, as indicated by increased sucrose intake in the Sucrose Preference Test (SPT), reduced immobility in the Forced Swimming Test (FST), and prolonged activity in the Out-of-Field Test (OFT). EA-Exo treatment improved depression-like behaviors by increasing serum levels of 5-hydroxytryptamine (5-HT) and decreasing immobility in the FST. It also alleviated OVX-CUMS-induced disturbances in energy metabolism, inflammation, and oxidative stress responses by enhancing serum levels of 5-HT, dopamine (DA), ATP, superoxide dismutase (SOD), and interleukin-10 (IL-10), while reducing cyclic AMP (cAMP), interleukin-6 (IL-6), reactive oxygen species (ROS), and malondialdehyde (MDA). Furthermore, EA-Exo treatment reversed structural and functional impairments in hippocampal synapses and mitochondria. This was evidenced by reductions in hippocampal synaptic plasticity proteins PSD95, SYN, and GAP43, as well as decreased expression of energy metabolism pathway proteins AMPK, NRF1, PGC1α, and TFAM. These findings suggest that EA-Exo ameliorates depressive behavior in OVX-CUMS rats by modulating synaptic plasticity and activating the AMPK/NRF1/PGC1α/TFAM signaling pathway.

PGC-1α drives small cell neuroendocrine cancer progression toward an ASCL1-expressing subtype with increased mitochondrial capacity

Adenocarcinomas from multiple tissues can converge to treatment-resistant small cell neuroendocrine (SCN) cancers composed of ASCL1, POU2F3, NEUROD1, and YAP1 subtypes. We investigated how mitochondrial metabolism influences SCN cancer (SCNC) progression. Extensive bioinformatics analyses encompassing thousands of patient tumors and human cancer cell lines uncovered enhanced expression of proliferator-activatedreceptor gamma coactivator 1-alpha (PGC-1α), a potent regulator of mitochondrial oxidative phosphorylation (OXPHOS), across several SCNCs. PGC-1α correlated tightly with increased expression of the lineage marker Achaete-scute homolog 1, (ASCL1) through a positive feedback mechanism. Analyses using a human prostate tissue-based SCN transformation system showed that the ASCL1 subtype has heightened PGC-1α expression and OXPHOS activity. PGC-1α inhibition diminished OXPHOS, reduced SCNC cell proliferation, and blocked SCN prostate tumor formation. Conversely, PGC-1α overexpression enhanced OXPHOS, validated by small-animal Positron Emission Tomography mitochondrial imaging, tripled the SCN prostate tumor formation rate, and promoted commitment to the ASCL1 lineage. These results establish PGC-1α as a driver of SCNC progression and subtype determination, highlighting metabolic vulnerabilities in SCNCs across different tissues.

Bilirubin, a hepatoprotective agent that activates SIRT1, PGC-1α, and PPAR-α, while inhibiting NF-κB in rats with metabolic-associated fatty liver disease

Metabolic-associated fatty liver disease (MAFLD) is a chronic liver disorder characterized by fatty liver disease alongside overweight or obesity and/or type 2 diabetes mellitus (T2DM). Timely intervention is crucial for a potential cure. This study aimed to investigate the effects of bilirubin, an endogenous antioxidant, on lipid metabolism and inflammation in MAFLD. Specifically, it examined bilirubin’s impact on SIRT1, PPAR-α, and NF-κB in the livers of rats with MAFLD induced by a high-fat diet (HFD) and streptozotocin (STZ) administration. Forty eight-week adult male Sprague Dawley rats were divided into five groups (n = 8): Control, HFD-STZ, HFD-S-BR6, HFD-S-BR14, and C-BR14. In the last three groups, bilirubin administration was performed intraperitoneally for 6 and 14 weeks (10 mg/kg/day). We selected the key genes associated with MAFLD and subsequently performed GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses to explore the enriched biological processes and signaling pathways. Hence, the gene expression of SIRT1, PGC-1α, PPAR-α, and inflammatory genes (NF-κB, TNF-α, IL-6, and IL-1β) was measured using Real-time quantitative PCR. Stereological and histopathological alterations of liver structure as well as lipid profile, biochemical indices, and liver indices, were also assessed among different groups. The enrichment analysis identified that several signaling pathways and biological processes might be related to MAFLD. Bilirubin-treated rats contained higher PPAR-α, PGC-1α, and SIRT1 expression levels by approximately 5.7-, 2.1-, and 2.2-fold, respectively, compared to the HFD-receiving rats (p < 0.0001, p < 0.05, and p < 0.05). Whereas, the genes involved in the inflammatory cascades, including NF-κB, TNF-α, and IL-6, were downregulated by 0.6-fold (p < 0.05) following 14-week treatment of bilirubin, while only significantly decreased expression of NF-κB and IL-6 (approximately 0.6-fold, p < 0.05) were observed after 6-week treatment of bilirubin. Remarkably, bilirubin administration favorably reversed the effects of HFD on the liver’s volume and cell numbers and ameliorated the related structural changes. It also improved lipid profile, biochemical parameters, and liver indices of HFD-STZ rats. This study indicated that bilirubin acts as a protective/ameliorative compound against MAFLD, particularly through regulating the key genes involved in lipid metabolism and inflammation in HFD-STZ rats.

Mechanism of Valeriana officinalis L. extract improving atherosclerosis by regulating PGC-1α/Sirt3/Epac1 pathway.

To investigate the protective effect of the of Valeriana officinalis L. extract on mitochondrial injury in AS mice and the underlying mechanism. Firstly, Ultra-High performance liquid chromatography-quadrupole time-of-flight mass spectrometer (UPLC / Q-TOF-MS) was proposed to explore the chemical composition of Valeriana officinalis L. extract. ApoE-/- mice were employed for in vivo experiments. The efficacy of Valeriana officinalis L. extract was detected by B-ultrasound, Biochemical, Oil Red O staining, HE staining and Masson staining analysis. The molecular mechanism of Valeriana officinalis L. extract in regulating mitochondrial energy metabolism for the treatment of atherosclerosis was elucidated after Monitoring System of Vascular Microcirculation in Vivo and transmission electron microscopy. Use the corresponding reagent kit to detect ACTH level, CHRNα1 level and ATP level, and measure the expression levels of PGC-1α, Sirt3, Epac1, Caspase-3, and Caspase-9 through real-time qPCR, and Western blot. A total of 29 metabolites were newly discovered from KYXC using UPLC-MS. The drug had a significant positive effect on the growth of atherosclerotic plaque in mice. It also improved the microcirculation of the heart and mesentery, reduced the levels of CHOL, TG, and VLDL in the serum, and increased the levels of HDL-C to maintain normal lipid metabolism in the body. Additionally, it increased the levels of ATP, improved the ultrastructure of mitochondria to maintain mitochondrial energy metabolism, and increased the levels of T-SOD to combat oxidative stress of the organism. Furthermore, the drug significantly increased the mRNA and protein expression of PGC-1α and Sirt3 in aortic tissue, while decreasing the mRNA and protein expression of Epac1, Caspase-3, and Caspase-9. This study has verified that the extract of Valeriana officinalis L. is highly effective in enhancing atherosclerosis disease. The mechanism is suggested through the PGC-1α/Sirt3/Epac1 signaling pathway, which improves mitochondrial energy metabolism.

Resistance Exercise Improves Glycolipid Metabolism and Mitochondrial Biogenesis in Skeletal Muscle of T2DM Mice via miR-30d-5p/SIRT1/PGC-1α Axis.

Exercise is a recognized non-pharmacological treatment for improving glucose homeostasis in type 2 diabetes (T2DM), with resistance exercise (RE) showing promising results. However, the mechanism of RE improving T2DM has not been clarified. This study aims to investigate the effects of RE on glucose and lipid metabolism, insulin signaling, and mitochondrial function in T2DM mice, with a focus on the regulatory role of miR-30d-5p. Our results confirmed that RE significantly improved fasting blood glucose, IPGTT, and ITT in T2DM mice. Enhanced expression of IRS-1, p-PI3K, and p-Akt indicated improved insulin signaling. RE improved glycolipid metabolism, as well as mitochondrial biogenesis and dynamics in skeletal muscle of T2DM mice. We also found that miR-30d-5p was upregulated in T2DM, and was downregulated after RE. Additionally, in vitro, over-expression of miR-30d-5p significantly increased lipid deposition, and reduced glucose uptake and mitochondrial biogenesis. These observations were reversed after transfection with the miR-30d-5p inhibitor. Mechanistically, miR-30d-5p regulates glycolipid metabolism in skeletal muscle by directly targeting SIRT1, which affects the expression of PGC-1α, thereby influencing mitochondrial function and glycolipid metabolism. Taken together, RE effectively improves glucose and lipid metabolism and mitochondrial function in T2DM mice, partly through regulating the miR-30d-5p/SIRT1/PGC-1α axis. miR-30d-5p could serve as a potential therapeutic target for T2DM management.

High-iron diet damages brown adipose tissue mitochondria and exacerbates metabolic hazards of a high-fat diet

Metabolic diseases may be prevented by reducing carbohydrate intake and replacing plant-based diets with animal-based ones low in carbohydrates but high in protein, fat, and iron. While the effects of sugars on metabolic diseases are well-known, the role of iron remains unclear. This study aimed to explore the effects of a high-fat high-iron animal diet on body metabolism in mice. Micro-PET imaging was used to assess 18-F-labelled glucose uptake in BAT, and the morphology, respiratory function, and oxidative stress of BAT mitochondria were examined. The underlying mechanisms were elucidated by analyzing the expression of UCP-1, PGC-1α and PPARα. The high-iron high-fat diet increased appetite, impaired glucose tolerance, and reduced insulin sensitivity. Additionally, the high-iron diet promoted gluconeogenesis only in the absence of high-fat levels. Both high-iron and high-fat diets suppressed BAT activity, increased mitochondrial oxidative stress, decreased mitochondrial respiratory function, and lowered thermogenic gene expression. Weight loss strategies focusing solely on reducing carbohydrates and increasing animal foods, like ketogenic diets, may have long-term detrimental effects on metabolic health. Prioritizing dietary diversity and monitoring overall caloric intake is advisable for optimal outcomes.

Abstract 4121527: Empagliflozin Improves Mitochondrial Biogenesis in Pulmonary Arterial Hypertension

Background: Pulmonary arterial hypertension (PAH) is a devastating disease characterized by endothelial proliferation and progressive pulmonary vascular (PV) remodeling. Empagliflozin (EMPA), a sodium glucose cotransporter 2 (SGLT2) inhibitor, benefits heart failure patients, potentially mediated by improved mitochondrial function. This study aimed to explore the impact of EMPA in PAH. Methods and Results: Immunohistochemistry of pulmonary arteries revealed the expression of SGLT2 in the intima of PAH patients. Microvascular endothelial cells (MVECs) were isolated from lungs of control subjects (CTRL) and PAH patients and found intense expression of SGLT2 in PAH MVECs. Western blot showed significantly higher expression of SGLT2, while PGC-1α, a transcriptional coactivator known as a master regulator of mitochondrial biogenesis, was lower in PAH MVECs compared to CTRL (Image 1). PAH MVECs were treated with EMPA (1 μM) and observed a significant increase of PGC-1α and BMPR2-pSmad1/5/9. Similarly, knockdown of SGLT2 using siRNA resulted in enhanced expression of PGC-1α. Moreover, Seahorse analysis revealed increased oxygen consumption rate and reduced extracellular acidification rate by EMPA, suggesting that EMPA improved mitochondrial respiration. In addition, EMPA attenuated reactive oxygen species and proliferation of PAH MVECs, as revealed by MitoTracker analysis and MTT assay respectively. For the in vivo study, Sprague-Dawley rats (120-180 gram) were injected with SU5416 (Week-0) and exposed to hypoxia for 3 weeks followed by normoxia. After randomization at Week-4, rats were treated with EMPA (300 mg/kg in chow, n=12) or placebo (PLAC, n=12). Catheterization and histological analysis were performed at Week-8. EMPA decreased PV resistance index (0.21±0.02 vs. 0.37±0.05 mmHg/mL/min/mm 2 , p=0.01), ameliorated intima thickening (21.0±7.5 vs. 40.0±7.8%, p&lt;0.01) and vessel occlusion (Image 2). We further conducted a single-center, open-label, single-arm interventional proof-of-concept study to assess the tolerability of 12 weeks of treatment with 10mg of EMPA as add-on therapy in eight patients with a prior PAH diagnosis. There were no treatment related adverse events during the study time course. Conclusions: EMPA directly improved mitochondrial biogenesis and attenuated proliferation of MVECs from PAH patients and reversed PV remodeling in experimental PAH. EMPA treatment was feasible in patients with PAH. EMPA may serve as a new therapeutic option for PAH.

Olive oil protects against cardiac hypertrophy in D-galactose induced aging rats

BackgroundAged heart is defined via structural and mitochondrial dysfunction of the heart. However, there is still no potent compound to improve cardiac function abnormalities in aged individuals. Olive oil (OLO), as an oil with monounsaturated fatty acids, has diverse protective effects on the cardiovascular system, including anti-inflammatory, anti-diabetic, and mitigating effects on blood pressure. In the present study, we evaluated the protective effects of OLO against aging-related cardiac dysfunction.MethodsMale Wistar rats were randomly divided into three groups: Control, D-galactose-induced aging rats (D-GAL group), and aging rats treated with OLO (D-GAL + OLO group). Aging in rats was induced by intraperitoneal injection of D-GAL at 150 mg/kg dose for eight weeks and the D-GAL + OLO group was treated with oral OLO by gavage for eight weeks. The heart tissues were harvested to assay the oxidative stress, molecular parameters, and histological analysis.ResultsThe D-GAL given rats indicated increased cardiomyocyte diameter as cardiac hypertrophy marker (21 ± 0.8, p < 0.001), an increased Malondialdehyde (MDA) level (27 ± 3, p < 0.001), a reduced Superoxide dismutase (SOD) (p < 0.001, 18.12 ± 1.3), and reduction in gene expression of Sirtuin 1 (SIRT1) (p < 0.05, 0.37 ± 0.06), Peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1α (p < 0.001, 0.027 ± 0.04), and Transcription Factor A, Mitochondrial (TFAM) (p < 0.001, 0.023 ± 0.01), Bcl2 (p < 0.001, 0.04 ± 0.004) and an increase in gene expression of Bax (p < 0.001, 23.5 ± 5.4) in comparison with the control animals. Treatment with OLO improved cardiac hypertrophy (14 ± 0.4, p < 0.001), MDA (22 ± 2.5, p < 0.01), SOD (p < 0.001, 34.9 ± 2), SIRT1 (p < 0.05, 1.37 ± 0.46), PGC-1α (p < 0.001, 1.11 ± 0.1), TFAM (p < 0.01, 0.23 ± 0.02), Bcl2 (p < 0.05, 0.35 ± 0.05) and Bax genes (p < 0.01, 0.1 ± 0.03).ConclusionsOverall, OLO protects the heart against D-GAL-induced aging via increasing antioxidant effects, and enhancing cardiac expression of SIRT1, PGC-1α, TFAM, Bcl2 and Bax genes.Graphical

Klf9 is essential for cardiac mitochondrial homeostasis.

Mitochondrial dynamics and mitophagy are intimately linked physiological processes that are essential for cardiac homeostasis. Here we show that cardiac Krüppel-like factor 9 (Klf9) is dysregulated in human and rodent cardiomyopathy. Both global and cardiac-specific Klf9-deficient mice displayed hypertrophic cardiomyopathy. Klf9 knockout led to mitochondrial disarray and fragmentation, impairing mitochondrial respiratory function in cardiomyocytes. Furthermore, cardiac Klf9 deficiency inhibited mitophagy, thereby causing accumulation of dysfunctional mitochondria and acceleration of heart failure in response to angiotensin II treatment. In contrast, cardiac-specific Klf9 transgene improved cardiac systolic function. Mechanistically, Klf9 knockout decreased the expression of PGC-1α and its target genes involved in mitochondrial energy metabolism. Moreover, Klf9 controlled the expression of Mfn2, thereby regulating mitochondrial dynamics and mitophagy. Finally, adeno-associated virus-mediated Mfn2 rescue in Klf9-CKO hearts improved cardiac mitochondrial and systolic function. Thus, Klf9 integrates cardiac energy metabolism, mitochondrial dynamics and mitophagy. Modulating Klf9 activity may have therapeutic potential in the treatment of heart failure.

ZLN005 Reduces Neuroinflammation and Improves Mitochondrial Function in Mice with Perioperative Neurocognitive Disorders.

The decrease expression of PGC-1α contributes to perioperative neurocognitive disorders (PND). This study aimed to investigate the effects of the PGC-1α agonist ZLN005 in preventing PND and to explore the potential mechanism. C57BL/6 mice were randomly divided into four groups: the control group (Group C), the surgery group (Group S), the surgery and ZLN005 (5 mg/(kg⋅d)) group (Group L), and the surgery and ZLN005 (7.5 mg/(kg⋅d)) group (Group H). Except for Group C, the other three groups received intraperitoneal injections of vehicle or ZLN005 once a day from 3 days before surgery to 3 days after surgery. The open field test, novel object recognition test and fear conditioning test were performed to measure anxiety behaviors, locomotor activity and memory. The levels of IL-6 and IL-1β were measured at 24hours after surgery. ATP and ROS levels were measured at 3 days post-surgery. PGC-1α, NRF-1, Atp5d, Atp5k and Cox5a were measured at one day or three days post-surgery. ZLN005 treatment improved the cognitive function of mice in Group L and Group H compared with Group S. The expression of IL-6 and IL-1β in the hippocampus of the S group was increased after surgery, and ZLN005 reduced the expression of IL-6 and IL-1β in the hippocampus of mice one day after surgery. There were parallel decreases in the expression of PGC-1α/NRF-1 and mitochondrial function in the hippocampus of the Group S mice compared with the Group C mice. The expression of PGC-1α/NRF-1 and mitochondrial function were upregulated after ZLN005 treatment. Neuroinflammation and mitochondrial damage are involved in the occurrence of PND. ZLN005 activates PGC-1α to increase the expression of mitochondrial proteins, improve mitochondrial function, and ultimately ameliorate the cognitive status of mice after surgery.

Effect and related mechanism of acetate in alleviating acute kidney injury in septic rats through G-protein coupled receptor 43

To explore the protective effect and mechanism of acetate on sepsis-induced acute kidney injury (AKI) in rats. Male Sprague-Dawley (SD) rats were divided into sham operation group (Sham group), sepsis group caused by cecal ligation and puncture (CLP group), and acetate pretreatment group [NaA group, gavage sodium acetate (NaA) 300 mg/kg twice a day for 7 consecutive days before CLP] using a random number table method, with 7 rats in each group. The blood was taken from the main abdominal artery 24 hours after modeling, and renal tissue was collected from the rats. Enzyme linked immunosorbent assay (ELISA) was used to detect the serum levels of interleukin-6 (IL-6), tumor necrosis factor-α(TNF-α), and kidney injury molecule-1 (KIM-1). The concentration of serum acetate was determined by high performance liquid chromatography. The level of malondialdehyde (MDA) in renal tissue was detected by thiobarbituric acid method. Myeloperoxidase (MPO) in renal tissue was detected by colorimetric method. Hematoxylin-eosin (HE) staining was used to observe histopathological changes and assess renal tubule injury score. Western blotting was used to detect the protein expressions of G-protein coupled receptor 43 (GPR43) and adenosine monophosphate-activated protein kinase/silence infor-mation regulator 1/peroxlsome proliferator-activated receptor-γ coactlvator-1α (AMPK/SIRT1/PGC-1α) pathway. The positive expressions of GPR43, phosphorylation-AMPK (p-AMPK), SIRT1, PGC-1α were detected by immunohistochemistry. Compared with Sham group, the serum levels of IL-6, TNF-α and KIM-1 were significantly increased in CLP group, the contents of MDA and MPO in renal tissue were increased, and the content of acetate was significantly decreased. HE staining results showed that most of the tubular epithelial cells were denaturated with local necrosis, a large number of brush border injuries and shedding, tubular structure destruction and fragmentation, and more inflammatory cells infiltrated the renal interstitium, the renal tubular injury score significantly increased. The expressions of GPR43, p-AMPK/AMPK, SIRT1, and PGC-1α in renal tissue were significantly reduced, indicating renal injury and increased levels of oxidative stress and inflammation in septic rats. Compared with the CLP group, the serum levels of IL-6, TNF-α and KIM-1 in the NaA group were decreased [IL-6 (ng/L): 126.20±6.23 vs. 161.00±17.37, TNF-α (ng/L): 85.59±7.70 vs. 123.50±17.78, KIM-1 (μg/L): 2.92±0.38 vs. 4.73±0.36, all P < 0.05]. The contents of MDA and MPO in renal tissue were significantly decreased [MDA (μmol/g): 6.56±0.18 vs. 8.53±0.34, MPO (U/g): 2.99±0.20 vs. 3.72±0.29, both P < 0.05]. HE staining showed that kidney injury had been alleviated, with a decrease in renal tubular injury score [1 (1, 2) vs. 3 (2, 3), P < 0.05]. Western blotting showed that the expressions of GPR43 and AMPK/SIRT1/PGC-1α pathway related proteins were significantly increased in renal tissue (GPR43/β-actin: 0.62±0.09 vs. 0.41±0.09, p-AMPK/AMPK: 0.58±0.07 vs. 0.44±0.06, SIRT1/β-actin: 0.85±0.06 vs. 0.73±0.03, PGC-1α/β-actin: 0.79±0.07 vs. 0.62±0.05, all P < 0.05). Immunohistochemistry showed that the positive expressions of GPR43, p-AMPK, SIRT1 and PGC-1α were significantly increased in renal tissue [GPR43 positive area: (33.66±2.62)% vs. (16.21±1.66)%, p-AMPK positive area: (16.64±2.11)% vs. (5.04±1.28)%, SIRT1 positive area: (14.61±2.86)% vs. (7.34±1.00)%, PGC-1α positive area: (15.30±2.39)% vs. (4.84±1.67)%, all P < 0.05], the serum acetate concentration significantly increased (μg/L: 32 479±14 683 vs. 12 935±3 197, P < 0.05). Acetate can ameliorate sepsis-induced AKI, the mechanism may be related to the activation of AMPK/SIRT1/PGC-1α pathway by GPR43.

Hydrogen Protects Mitochondrial Function by Increasing the Expression of PGC-1α and Ameliorating Myocardial Ischaemia-Reperfusion Injury.

To investigate the application of H2 to alleviate cardiac ischaemia-reperfusion (I/R) injury in a PGC-1α-dependent manner. Arat invitro myocardial I/R injury model was used, Western blot was used to detect the expression levels of apoptosis markers (Bax, cleaved caspase-3, Bcl2), inflammatory factors (IL-1β, TNF-α), mitochondrial fission (DRP1, MFF) and mitochondrial fusion (MFN1, MFN2, OPA1). HE staining was used to observe the effect of H2 on the myocardial tissue structure injured by I/R. Transmission electron microscopy (TEM) was used to observe the changes in the mitochondrial structure of myocardial tissue after I/R injury. Real-time quantitative PCR (qPCR) was used to detect the expression of PGC-1α in the myocardial tissue of rats after I/R injury and H2 treatment. H2 increases the expression level of PGC-1α, while the deletion of PGC-1α inhibited the therapeutic effect of H2. H2 can improve the changes of the myocardial tissue and mitochondrial structure caused by I/R injury. H2 treatment effectively inhibited the inflammatory response, and the loss of PGC-1α could inhibit the therapeutic effect of H2. The application of H2 can alleviate myocardial I/R injury, and the loss of PGC-1α weakens the protective effect of H2 on the I/R heart.

An AMP-activated protein kinase-PGC-1α axis mediates metabolic plasticity in glioblastoma.

Glioblastoma, the most frequent primary malignant brain tumour in adults, is characterised by profound yet dynamic hypoxia and nutrient depletion. To sustain survival and proliferation, tumour cells are compelled to acquire metabolic plasticity with the induction of adaptive metabolic programs. Here, we interrogated the pathways necessary to enable processing of nutrients other than glucose. We employed genetic approaches (stable/inducible overexpression, CRISPR/Cas9 knockout), pharmacological interventions with a novel inhibitor of AMP-activated protein kinase (AMPK) in glioblastoma cell culture systems and a proteomic approach to investigate mechanisms of metabolic plasticity. Moreover, a spatially resolved multiomic analysis was employed to correlate the gene expression pattern of PGC-1α with the local metabolic and genetic architecture in human glioblastoma tissue sections. A switch from glucose to alternative nutrients triggered an activation of AMPK, which in turn activated PGC-1α-dependent adaptive programs promoting mitochondrial metabolism. This sensor-effector mechanism was essential for metabolic plasticity with both functional AMPK and PGC-1α necessary for survival and growth of cells under nonglucose nutrient sources. In human glioblastoma tissue specimens, PGC-1α-expression correlated with nonhypoxic tumour niches defining a specific metabolic compartment. Our findings reveal a cell-intrinsic nutrient sensing and switching mechanism. The exposure to alternative fuels triggers a starvation signal that subsequently is passed on via AMPK and PGC-1α to induce adaptive programs necessary for broader spectrum nutrient metabolism. The integration of spatially resolved transcriptomic data confirms the relevance of PGC-1α especially in nonhypoxic tumour regions. Thus, the AMPK-PGC-1α axis is a candidate for therapeutic inhibition in glioblastoma. KEY POINTS/HIGHLIGHTS: AMPK activation induces PGC-1α expression in glioblastoma during nutrient scarcity. PGC-1α enables metabolic plasticity by facilitating metabolism of alternative nutrients in glioblastoma. PGC-1α expression is inversely correlated with hypoxic tumour regions in human glioblastomas.

Hemin attenuates bleomycin-induced lung fibrosis in mice by regulating the TGF-β1/MAPK and AMPK/SIRT1/PGC-1α/HO-1/NF-κB pathways.

The objective of this study was to investigate the protective effect and potential mechanism of action of hemin on bleomycin-induced pulmonary fibrosis in mice. Male C57BL/6 mice were randomly divided into control, bleomycin and bleomycin + hemin groups. Mice in the bleomycin and bleomycin + hemin groups were injected intratracheally with bleomycin to establish the pulmonary fibrosis model. The bleomycin + hemin group mice were injected intraperitoneally with hemin starting 7 days before modeling until the end of Day 21 after modeling. Pathological changes in lung tissue were assessed by HE and Masson staining. Malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) levels were determined in lung tissue. Immunohistochemistry was performed to assess the expression of α-SMA and collagen I. The serum levels of IL-6 and TNF-α were measured via ELISA. Western blotting was used to determine the expression of TGF-β1, SIRT1, PGC-1α and HO-1 and the phosphorylation levels of p38, ERK1/2, JNK, AMPK and NF-κB p65 in lung tissue. Hemin significantly reduced lung indices, increased terminal body weight. It also significantly increased SOD and CAT activities; decreased MDA, IL-6 and TNF-α levels; reduced the levels of α-SMA and collagen I-positive cells; upregulated SIRT1, PGC-1α and HO-1 expression; promoted AMPK phosphorylation; and downregulated TGF-β1 expression and p38, ERK1/2, JNK and NF-κB p65 phosphorylation. Hemin might attenuate oxidative damage and inflammatory responses and reduces extracellular matrix deposition by regulating the expression and phosphorylation of proteins associated with the TGF-β1/MAPK and AMPK/SIRT1/PGC-1α/HO-1/NF-κB pathways, thereby alleviating bleomycin-induced pulmonary fibrosis.

Zhuangyao Jianshen Wan ameliorates senile osteoporosis in SAMP6 mice through Modulation of the GCN5L1-mediated PI3K/Akt/wnt signaling pathway

BackgroundSenile osteoporosis (SOP) is a systemic bone disease characterized by increased susceptibility to fractures. However, there is currently no effective treatment for SOP. The Zhuangyao Jianshen Wan (ZYJSW) pill is traditionally believed to possess kidney-nourishing and bone-strengthening effects, demonstrating efficacy in treating fractures. Despite this, its effectiveness and mechanism in SOP remain unclear. This study aims to investigate the therapeutic potential of ZYJSW in treating SOP in senescence accelerated mouse prone 6 (SAMP6, P6) mice, and elucidate the underlying mechanisms. MethodsFour-month-old SAMP6 mice were categorized into six groups: the model group (SAMP6), low, medium, and high-dose ZYJSW treatment groups, calcitriol treatment (positive control 1) group, and metformin treatment (positive control 2) group. Gastric administration was carried out for 15 weeks, and a normal control group comprising four-month-old Senescence-Accelerated Mouse Resistant 1 (SAMR1) mice. Changes in body weight, liver and kidney function, bone protective effects, and muscle quality were evaluated using various assays, including H&E staining, Goldner staining, bone tissue morphology analysis, Micro-CT imaging, and biomechanical testing. Qualitative analysis and quality control of ZYJSW were performed via LC-MS/MS analysis. To explore mechanisms, network pharmacology and proteomics were employed, and the identified proteins were validated by Western blotting. ResultsOral administration of ZYJSW to P6 mice exerted preventive efficacy against osteopenia, impaired bone microstructure, and poor bone and muscle quality. ZYJSW attenuated the imbalance in bone metabolism by promoting bone formation, as evidenced by the upregulation of key factors such as Runt-related transcription factor 2 (RUNX2), Bone Morphogenetic Protein (BMP2), Osteoprotegerin (OPG) and Osteocalcin (OCN), while simultaneously inhibiting bone resorption through the downregulation of TNF receptor associated factor 6 (TRAF6), Tartrate resistant acid phosphatase (TRAP), Receptor activator for nuclear factor-κB ligand (RANKL) and Cathepsin K (CTSK). Additionally, ZYJSW enhanced muscle structure and function by counteracting the elevation of Ubiquitin (Ub), Muscle RING-finger protein-1 (Murf-1), F-Box Protein 32 (FBOX32), and Myogenin (Myog). Network pharmacology predictions, proteomics analysis corroborated by published literature demonstrated the role of ZYJSW involving in safeguarding mitochondrial biogenesis. This was achieved by suppressing GCN5L1 expression, contributing to the heightened expression of TFAM, PGC-1α, and nuclear respiratory factor-1 (NRF-1) proteins. ZYJSW also positively modulated Wnt signaling pathways responsible for bone formation, due to regulating expressions of key components like β-catenin, GSK-3β, and LRP5. In addition, ZYJSW causes the downregulation of the PI3K/Akt pathway by inhibiting the phosphorylation of both PI3K and Akt. ConclusionsThe study highlights the significance of ZYJSW in preserving the health of both bone and muscle in P6 mice, potentially through the regulation of the GCN5L1-mediated PI3K/Akt/Wnt signaling pathway. The translational potential of this articleOur research provides evidence and a mechanistic rationale for ZYJSW as a candidate for SOP treatment, offering insights for further exploration and strategy development.

Palm and Interesterified palm oil-enhanced brown fat whitening contributes to metabolic dysfunction in C57BL/6J mice

Palm oil is widely used in the food industry owing to its high stability and versatility. The interesterified version has been used as an alternative to oils rich in trans fatty acids. However, the health effects of these vegetable oils are not yet fully understood. We hypothesized that the consumption of palm oil (non-interesterified and interesterified), even without excessive amounts of energy and lipids in the diet, could lead to morphofunctional changes in brown adipose tissue (BAT). To this end, male C57BL/6J mice were divided into three dietary groups (n = 10 each): soybean oil (SO), palm oil (PO), and interesterified palm oil (IPO) for 10 weeks. The PO and IPO groups had significant increases in the visceral fat mass and interscapular BAT (iBAT) lipid content. In iBAT, the PO and IPO groups showed lower mRNA expression of Ucp1, Adrb3, and Pgc1a, while the PO also showed lower mRNA levels of Ppara and Ampk, and the IPO showed lower Prdm16 expression. Moreover, PO had higher Il6 expression and lower catalase activity, while the IPO showed an upregulated Tnfa expression and lower catalase activity, but higher antioxidant activity of the glutathione peroxidase (GPx) enzyme. The consumption of PO and IPO had negative effects on weight and body fat, including the impairment of iBAT function. Our findings give rise to apprehensions regarding the safety and consequences of consuming palm and interesterified palm oils for energy metabolism.

Effects of Dietary Restriction on PGC-1α Regulation in the Development of Age-associated Diseases.

Ageing is the most significant risk factor for a number of non-communicable diseases, manifesting as cognitive, metabolic, and cardiovascular diseases. Although multifactorial, mitochondrial dysfunction and oxidative stress have been proposed to be the driving forces of ageing. Peroxisome proliferator-activated receptor γ coactivator α (PGC-1α) is a transcriptional coactivator central to various metabolic functions, of which mitochondrial biogenesis is the most prominent function. Inducible by various stimuli, including nutrient limitations, PGC-1α is a molecule of interest in the maintenance of mitochondrial function and, therefore, the prevention of degenerative diseases. This review involves a literature search for articles retrieved from PubMed using PGC-1α, ageing, and dietary restriction as keywords. Dietary restriction has been shown to promote tissue-specific PGC-1α expression. Both dietary restriction and PGC-1α upregulation have been shown to prolong the lifespans of both lower and higher-level organisms; the incidence of non-communicable diseases also decreased in fasting mammals. In conclusion, dietary interventions may delay ageing by regulating healthy mitochondria in various organs, presenting the possibility of a new primary prevention for many age-related diseases.