MicroRNA-29b Plays a Vital Role in Podocyte Injury and Glomerular Diseases through Inducing Mitochondrial Dysfunction.

Diabetic kidney disease (DKD) is becoming the most leading cause of end-stage renal disease (ESRD). Podocyte injury plays a critical role in DKD progression. Notably, mitochondrial dysfunction is crucial for podocyte injury. MicroRNAs (miRNAs) involves in various kidney diseases. Herein, we discovered miR-29b was induced in the urine of 126 patients with DKD (stage I and II), and negatively correlated with kidney function and podocyte homeostasis. Mechanically, miR-29b targeted peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), a co-activator of transcription factors regulating mitochondrial biogenesis and energy metabolism. In vitro, ectopic miR-29b downregulated PGC-1α and promoted podocyte injury, while inhibition of miR-29b alleviated podocyte injury. Consistently, inhibition of miR-29b mitigated podocyte injury and preserved kidney function in ADR nephropathy and db/db mice, and overexpression of miR-29b accelerated disease. Knockout miR-29b specifically in podocyte inhibited mitochondrial dysfunction and podocyte injury. These results revealed miR-29b plays a crucial role in mitochondrial dysfunction through targeted inhibition on PGC-1α, leading to podocyte injury and DKD progression. Importantly, miR-29b could serve as a novel biomarker of podocyte injury and assists to early diagnose DKD.

The bacterial quorum sensing signal 2'-aminoacetophenone rewires immune cell bioenergetics through the Ppargc1a/Esrra axis to mediate tolerance to infection.

How bacterial pathogens exploit host metabolism to promote immune tolerance and persist in infected hosts remains elusive. To achieve this, we show that Pseudomonas aeruginosa (PA), a recalcitrant pathogen, utilizes the quorum sensing (QS) signal 2'-aminoacetophenone (2-AA). Here, we unveil how 2-AA-driven immune tolerization causes distinct metabolic perturbations in murine macrophages' mitochondrial respiration and bioenergetics. We present evidence indicating that these effects stem from decreased pyruvate transport into mitochondria. This reduction is attributed to decreased expression of the mitochondrial pyruvate carrier (Mpc1), which is mediated by diminished expression and nuclear presence of its transcriptional regulator, estrogen-related nuclear receptor alpha (Esrra). Consequently, Esrra exhibits weakened binding to the Mpc1 promoter. This outcome arises from the impaired interaction between Esrra and the peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Ppargc1a). Ultimately, this cascade results in diminished pyruvate influx into mitochondria and, consequently reduced ATP production in tolerized murine and human macrophages. Exogenously added ATP in infected macrophages restores the transcript levels of Mpc1 and Esrra and enhances cytokine production and intracellular bacterial clearance. Consistent with the in vitro findings, murine infection studies corroborate the 2-AA-mediated long-lasting decrease in ATP and acetyl-CoA and its association with PA persistence, further supporting this QS signaling molecule as the culprit of the host bioenergetic alterations and PA persistence. These findings unveil 2-AA as a modulator of cellular immunometabolism and reveal an unprecedented mechanism of host tolerance to infection involving the Ppargc1a/Esrra axis in its influence on Mpc1/OXPHOS-dependent energy production and PA clearance. These paradigmatic findings pave the way for developing treatments to bolster host resilience to pathogen-induced damage. Given that QS is a common characteristic of prokaryotes, it is likely that 2-AA-like molecules with similar functions may be present in other pathogens.

Swimming alleviates myocardial fibrosis of type II diabetic rats through activating miR-34a-mediated SIRT1/PGC-1α/FNDC5 signal pathway.

Myocardial fibrosis can trigger heart failure in diabetic cardiomyopathy (DCM), and irisin, an exercise-induced myokine, may have a beneficial effect on cardiac function. However, the specific molecular mechanism between exercise and irisin in the diabetic heart remains not fully explored. This study aimed to investigate how miR-34a mediates exercise-induced irisin to ameliorate myocardial fibrosis and its underlying mechanisms. Type 2 diabetes mellitus (T2DM) with DCM was induced in adult male rats with high-fat diet and streptozotocin injection. The DCM rats were subjected to swimming (60 min/d) and recombinant irisin (r-irisin, 500 µg/kg/d) interventions for 8 weeks, respectively. Cardiac function, cardiomyocyte structure, myocardial fibrosis and its correlated gene and protein expression were analyzed. Swimming intervention alleviated insulin resistance, myocardial fibrosis, and myocardial hypertrophy, and promoted blood glucose homeostasis in T2DM model rats. This improvement was associated with irisin upregulation and miR-34a downregulation in the myocardium, thus enhancing cardiac function. Similar efficacy was observed via intraperitoneal injection of exogenous recombinant irisin. Inhibition of miR-34a in vivo exhibited an anti-myocardial fibrotic effect by promoting irisin secretion through activating sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α)/fibronectin type III domain-containing protein 5 (FNDC5) signal pathway and downregulating myocardial fibrosis markers (collagen I, collagen III, and transforming growth factor-ß1). Therefore, swimming-induced irisin has the potential therapeutic effect on diabetic myocardial fibrosis through activating the miR-34a-mediated SIRT1/PGC-1α/FNDC5 signal pathway.

GLIDR-mediated regulation of tumor malignancy and cisplatin resistance in non-small cell lung cancer via the miR-342-5p/PPARGC1A axis.

BACKGROUND: Lung cancer, particularly non-small cell lung cancer (NSCLC), remains a significant cause of cancer-related mortality, with drug resistance posing a substantial obstacle to effective therapy. LncRNAs have emerged as pivotal regulators of NSCLC progression, suggesting potential targets for cancer diagnosis and treatment. Therefore, identifying new lncRNAs as therapeutic targets and comprehending their underlying regulatory mechanisms are crucial for treating NSCLC. MATERIALS AND METHODS: RNA-sequencing data from 149 lung adenocarcinoma (LUAD) patients, including 130 responders and 19 nonresponders to primary treatment, were analyzed to identify the most effective lncRNAs. The effects and regulatory pathways of the selected lncRNAs on NSCLC and cisplatin resistance were investigated. RESULTS: Glioblastoma-downregulated RNA (GLIDR) was the most effective lncRNA in nonresponsive NSCLC patients undergoing primary treatment, and it was highly expressed in NSCLC patients and those with cisplatin-resistant NSCLC. Reducing GLIDR expression enhanced cisplatin sensitivity in resistant NSCLC and decreased the malignant characteristics of NSCLC. Moreover, bioinformatic analysis and luciferase assays revealed that microRNA-342-5p (miR-342-5p) directly targets GLIDR. MiR-342-5p overexpression inhibited NSCLC cell proliferation, migration, and invasion, whereas miR-342-5p inhibition promoted NSCLC malignancy, which was rescued by suppressing GLIDR. Peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PPARGC1A) was identified as a downstream target of miR-342-5p. PPARGC1A inhibition increased cisplatin sensitivity in resistant NSCLC. Moreover, PPARGC1A inhibition suppresses NSCLC malignancy, whereas PPARGC1A overexpression promoted it. Furthermore, GLIDR overexpression was found to counteract the inhibitory effects of miR-342-5p on PPARGC1A, and increased PPARGC1A expression reversed the inhibition of NSCLC malignancies caused by decreased GLIDR. CONCLUSIONS: GLIDR is a prognostic marker for cisplatin treatment in NSCLC and a therapeutic target in cisplatin-resistant NSCLC. GLIDR promotes NSCLC progression by sponging miR-342-5p to regulate PPARGC1A expression and regulates cisplatin resistance through the miR-342-5p/PPARGC1A axis, underscoring its potential as a therapeutic target in cisplatin-resistant NSCLC.

Sortilin-mediated translocation of mitochondrial ACSL1 impairs adipocyte thermogenesis and energy expenditure in male mice.

Beige fat activation involves a fuel switch to fatty acid oxidation following chronic cold adaptation. Mitochondrial acyl-CoA synthetase long-chain family member 1 (ACSL1) localizes in the mitochondria and plays a key role in fatty acid oxidation; however, the regulatory mechanism of the subcellular localization remains poorly understood. Here, we identify an endosomal trafficking component sortilin (encoded by Sort1) in adipose tissues that shows dynamic expression during beige fat activation and facilitates the translocation of ACSL1 from the mitochondria to the endolysosomal pathway for degradation. Depletion of sortilin in adipocytes results in an increase of mitochondrial ACSL1 and the activation of AMPK/PGC1α signaling, thereby activating beige fat and preventing high-fat diet (HFD)-induced obesity and insulin resistance. Collectively, our findings indicate that sortilin controls adipose tissue fatty acid oxidation by substrate fuel selection during beige fat activation and provides a potential targeted approach for the treatment of metabolic diseases.

SIRT1 Regulates Mitochondrial Damage in N2a Cells Treated with the Prion Protein Fragment 106-126 via PGC-1α-TFAM-Mediated Mitochondrial Biogenesis.

Mitochondrial damage is an early and key marker of neuronal damage in prion diseases. As a process involved in mitochondrial quality control, mitochondrial biogenesis regulates mitochondrial homeostasis in neurons and promotes neuron health by increasing the number of effective mitochondria in the cytoplasm. Sirtuin 1 (SIRT1) is a NAD+-dependent deacetylase that regulates neuronal mitochondrial biogenesis and quality control in neurodegenerative diseases via deacetylation of a variety of substrates. In a cellular model of prion diseases, we found that both SIRT1 protein levels and deacetylase activity decreased, and SIRT1 overexpression and activation significantly ameliorated mitochondrial morphological damage and dysfunction caused by the neurotoxic peptide PrP106-126. Moreover, we found that mitochondrial biogenesis was impaired, and SIRT1 overexpression and activation alleviated PrP106-126-induced impairment of mitochondrial biogenesis in N2a cells. Further studies in PrP106-126-treated N2a cells revealed that SIRT1 regulates mitochondrial biogenesis through the PGC-1α-TFAM pathway. Finally, we showed that resveratrol resolved PrP106-126-induced mitochondrial dysfunction and cell apoptosis by promoting mitochondrial biogenesis through activation of the SIRT1-dependent PGC-1α/TFAM signaling pathway in N2a cells. Taken together, our findings further describe SIRT1 regulation of mitochondrial biogenesis and improve our understanding of mitochondria-related pathogenesis in prion diseases. Our findings support further investigation of SIRT1 as a potential target for therapeutic intervention of prion diseases.

TRAP1 modulates mitochondrial biogenesis via PGC-1α/TFAM signalling pathway in colorectal cancer cells.

Metabolic rewiring promotes cancer cell adaptation to a hostile microenvironment, representing a hallmark of cancer. This process involves mitochondrial function and is mechanistically linked to the balance between mitochondrial biogenesis (MB) and mitophagy. The molecular chaperone TRAP1 is overexpressed in 60-70% of human colorectal cancers (CRC) and its over-expression correlates with poor clinical outcome, being associated with many cancer cell functions (i.e. adaptation to stress, protection from apoptosis and drug resistance, protein synthesis quality control, metabolic rewiring from glycolysis to mitochondrial respiration and vice versa). Here, the potential new role of TRAP1 in regulating mitochondrial dynamics was investigated in CRC cell lines and human CRCs. Our results revealed an inverse correlation between TRAP1 and mitochondrial-encoded respiratory chain proteins both at transcriptional and translational levels. Furthermore, TRAP1 silencing is associated with increased mitochondrial mass and mitochondrial DNA copy number (mtDNA-CN) as well as enhanced MB through PGC-1α/TFAM signalling pathway, promoting the formation of new functioning mitochondria and, likely, underlying the metabolic shift towards oxidative phosphorylation. These results suggest an involvement of TRAP1 in regulating MB process in human CRC cells. KEY MESSAGES: TRAP1 inversely correlates with protein-coding mitochondrial gene expression in CRC cells and tumours. TRAP1 silencing correlates with increased mitochondrial mass and mtDNA copy number in CRC cells. TRAP1 silencing favours mitochondrial biogenesis in CRC cells.

VEGF and ELAVL1/HuR protein levels are increased in dry and wet AMD patients. A new tile in the pathophysiologic mechanisms underlying RPE degeneration?

Age-related macular degeneration (AMD) is a common retinal pathology characterized by degeneration of macula's retinal pigment epithelium (RPE) and photoreceptors, visual impairment, or loss. Compared to wet AMD, dry AMD is more common, but lacks cures; therefore, identification of new potential therapeutic targets and treatments is urgent. Increased oxidative stress and declining antioxidant, detoxifying systems contribute to the pathophysiologic mechanisms underlying AMD. The present work shows that the Embryonic Lethal Abnormal Vision-Like 1/Human antigen R (ELAVL1/HuR) and the Vascular Endothelial Growth Factor (VEGF) protein levels are higher in the RPE of both dry and wet AMD patients compared to healthy subjects. Moreover, increased HuR protein levels are detected in the retina, and especially in the RPE layer, of a dry AMD model, the nuclear factor erythroid 2-related factor 2 (Nrf2) / peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) double knock-out mouse. The crosstalk among Nrf2, HuR and VEGF has been also studied in ARPE-19 cells in basal and stressful conditions related to the AMD context (i.e., oxidative stress, autophagy impairment, Nrf2 deficit), offering new evidence of the mutual influence between Nrf2 and HuR, of the dependence of VEGF expression and secretion by these two factors, and of the increased susceptibility of cells to stressful conditions in Nrf2- or HuR-impaired contexts. Overall, this study shows evidence of the interplay among Nrf2, HuR and VEGF, essential factors for RPE homeostasis, and represents an additional piece in the understanding of the complex pathophysiologic mechanisms underlying AMD.

Aberrant mitochondrial DNA synthesis in macrophages exacerbates inflammation and atherosclerosis.

There is a large body of evidence that cellular metabolism governs inflammation, and that inflammation contributes to the progression of atherosclerosis. However, whether mitochondrial DNA synthesis affects macrophage function and atherosclerosis pathology is not fully understood. Here we show, by transcriptomic analyzes of plaque macrophages, spatial single cell transcriptomics of atherosclerotic plaques, and functional experiments, that mitochondrial DNA (mtDNA) synthesis in atherosclerotic plaque macrophages are triggered by vascular cell adhesion molecule 1 (VCAM-1) under inflammatory conditions in both humans and mice. Mechanistically, VCAM-1 activates C/EBPα, which binds to the promoters of key mitochondrial biogenesis genes - Cmpk2 and Pgc1a. Increased CMPK2 and PGC-1α expression triggers mtDNA synthesis, which activates STING-mediated inflammation. Consistently, atherosclerosis and inflammation are less severe in Apoe-/- mice lacking Vcam1 in macrophages. Downregulation of macrophage-specific VCAM-1 in vivo leads to decreased expression of LYZ1 and FCOR, involved in STING signalling. Finally, VCAM-1 expression in human carotid plaque macrophages correlates with necrotic core area, mitochondrial volume, and oxidative damage to DNA. Collectively, our study highlights the importance of macrophage VCAM-1 in inflammation and atherogenesis pathology and proposes a self-acerbating pathway involving increased mtDNA synthesis.

Quercetin induces a slow myofiber phenotype in engineered human skeletal muscle tissues.

Skeletal muscle comprises slow and fast myofibers, with slow myofibers excelling in aerobic metabolism and endurance. Quercetin, a polyphenol, is reported to induce slow myofibers in rodent skeletal muscle both in vitro and in vivo. However, its effect on human myofiber types remains unexplored. In this study, we evaluated quercetin's impact on slow myofiber induction using human skeletal muscle satellite cells. In a two-dimensional culture, quercetin enhanced gene expression, contributing to muscle differentiation, and significantly expanded the area of slow-type myosin heavy chain positive cells. It also elevated the gene expression of Pgc1α, an inducer of slow myofibers. Conversely, quercetin did not affect mitochondrial abundance, fission, or fusion, but it did increase the gene expression of Cox7A2L, which aids in promoting mitochondrial supercomplexity and endurance, and Mb, which contributes to oxidative phosphorylation. In a three-dimensional culture, quercetin significantly extended the time to peak tension and half relaxation time of the engineered human skeletal muscle tissues constructed on microdevices. Moreover, quercetin enhanced the muscle endurance of the tissues and curbed the rise in lactate secretion from the exercised tissues. These findings suggest that quercetin may induce slow myofibers in human skeletal muscle.

Chlorogenic acid ameliorates muscle wasting by upregulating mRNA expressions of calcineurin and PGC-1α in diabetic rat model.

INTRODUCTION: Muscle health in diabetes mellitus (DM) is often neglected, which leads to muscle wasting. Increased reactive oxygen species in DM could decrease antioxidant enzymes such as superoxide dismutase-1 (SOD-1) and -2 (SOD-2) and inhibit calcineurin (CN) and PGC-1α signalling pathways. Chlorogenic acid (CGA) is known as a potent antioxidant and activators of CN and PGC-1α. This study aimed to determine the effect of CGA on mRNA expressions of SOD-1, SOD-2, CN and PGC-1α in inhibiting the progression of DM to muscle wasting. MATERIALS AND METHODS: This study was conducted at Department of Anatomy, Faculty of Medicine, Public Health, and Nursing, Universitas Gadjah Mada starting on July 20th, 2020. A total of 24 male Wistar rats were randomly divided into six groups (four rats per group), i.e., control, DM 1.5 months (DM1.5), and DM 2 months (DM2); and DM groups treated with CGA in three different doses, namely CGA1 (12.5 mg/kg BW), CGA2 (25 mg/kg BW), and CGA3 (50 mg/kg BW). Control group was only injected with normal saline, while diabetic model was induced by intraperitoneal injection of streptozotocin. Blood glucose levels were measured twice (one week after diabetic induction and before termination). The soleus muscle tissue was harvested to analyse the mRNA expressions of SOD-1, SOD- 2, CN and PGC-1α using RT-PCR. In addition, the tissue samples were stained with immunohistochemistry for CN and haematoxylin-eosin (HE) for morphologic analysis under light microscopy. RESULTS: The mRNA expressions of SOD-1 and SOD-2 in the CGA1 group were relatively higher compared to the DM2 groups. The mRNA expression of CN in the CGA1 group was significantly higher compared to the DM2 group (p = 0.008). The mRNA expression of PGC-1α in the CGA1 group was significantly higher compared to the DM2 group (p = 0.025). Immunohistochemical staining showed that CNimmunopositive expression in the CGA1 group was more evident compared to the other groups. Haematoxylin-eosin staining showed that muscle tissue morphology in the CGA1 group was similar to that in the control group. CONCLUSION: Chlorogenic acid at a dose of 12.5 mg/kg BW shows lower blood glucose level, good skeletal muscle tissue morphology and higher mRNA expressions of SOD-1, SOD-2, CN and PGC-1α compared to the DM groups.

Regulation mechanism of GPS2 on PGC-1α/Drp1-mediated mitochondrial dynamics in inflammation of acute lung injury.

Acute lung injury (ALI) has been a hot topic in the field of critical care research in recent years. Mitochondrial dynamics consists of mitochondrial fusion and mitochondrial fission. Dynamin-related protein 1 (Drp1), a key molecule that regulates mitochondrial fission, is important in the oxidative stress and inflammatory response to ALI. Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a core protein that mediates mitochondrial biogenesis. G-protein pathway suppressor 2 (GPS2) acts as a transcriptional cofactor with regulatory effects on nuclear-encoded mitochondrial genes. This study aimed to investigate the mechanism of PGC-1α/Drp1-mediated mitochondrial dynamics involved in ALI and to demonstrate the protective mechanism of GPS2 in regulating mitochondrial structure and function and inflammation in ALI. The ALI model was constructed using LPS-induced wild-type mice and human pulmonary microvascular endothelial cells (HPMVECs). It was found that lung injury, oxidative stress and inflammation were exacerbated in the mice ALI model and that mitochondrial structure and function were disrupted in HPMVECs. In vitro studies revealed that LPS led to the upregulated expression of Drp1 and the downregulated expression of PGC-1α and GPS2. Mitochondrial division was reduced and respiratory function was restored in Drp1 knockdown cells, which inhibited oxidative stress and inflammatory response. In addition, the overexpression of PGC-1α and GPS2 significantly inhibited the expression of Drp1, mitochondrial function was restored, and inhibited reactive oxygen species (ROS) production and inflammatory factor release. Moreover, the overexpression of GPS2 promoted the upregulated expression of PGC-1α. This mechanism was also validated in vivo, in which the low expression of GPS2 in mice resulted in the upregulated expression of Drp1 and the downregulated expression of PGC-1α, and further exacerbated LPS-induced ALI. In the present study, we also found that LPS-induced the downregulated expression of GPS2 may be associated with its increased degradation by the proteasome. Therefore, these findings revealed that GPS2 inhibited oxidative stress and inflammation by modulating PGC-1α/Drp1-mediated mitochondrial dynamics to alleviate LPS-induced ALI, which may provide a new approach to the therapeutic orientation for LPS-induced ALI.

Exogenous expression of PGC-1α during in vitro maturation impairs the developmental competence of porcine oocytes.

Objectives of the current study were to examine the effects of exogenous expression of PGC-1α, which is a transcription factor responsive for controlling mitochondrial DNA (mtDNA) replication, mitochondria quantity control, mitochondrial biogenesis, and reactive oxygen species (ROS) maintenance, in porcine oocytes during in-vitro maturation (IVM) on the developmental competence, as well as mitochondrial quantity and function. Exogenous over-expression of PGC-1α by injection of the mRNA construct into oocytes 20 h after the start of IVM culture significantly increased the copy number of mtDNA in the oocytes, but reduced the incidences of oocytes matured to the metaphase-II stage after the IVM culture for totally 44 h and completely suppressed the early development in vitro to the blastocyst stage following parthenogenetic activation. The exogenous expression of PGC-1α also significantly induced spindle defects and chromosome misalignments. Furthermore, markedly higher ROS levels were observed in the PGC-1α-overexpressed mature oocytes, whereas mRNA level of SOD1, encoded for a ROS scavenging enzyme, was decreased. These results conclude that forced expression of PGC-1α successfully increase mtDNA copy number but led to increased ROS production, evidently by downregulation of SOD1 gene expression, inducement of spindle aberration/chromosomal misalignment, and consequently reduction in the meiotic and developmental competences of porcine oocytes.

Cannabinoid receptor 2 plays a key role in renal fibrosis through inhibiting lipid metabolism in renal tubular cells.

AIMS: Renal fibrosis is a common feature in various chronic kidney diseases (CKD). Tubular cell damage is a main characterization which results from dysregulated fatty acid oxidation (FAO) and lipid accumulation. Cannabinoid Receptor 2 (CB2) contributes to renal fibrosis, however, its role in FAO dysregulation in tubular cells is not clarified. In this study, we found CB2 plays a detrimental role in lipid metabolism in tubular cells. METHODS: CB2 knockout mice were adopted to establish a folic acid-induced nephropathy (FAN) model. CB2-induced FAO dysfunction, lipid deposition, and fibrogenesis were assessed in vivo and vitro. To explore molecular mechanisms, ß-catenin inhibitors and peroxisome proliferator-activated receptor alpha (PPARα) activators were also used in CB2-overexpressed cells. The mediative role of ß-catenin in CB2-inhibited PPARα and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) activation was analyzed. RESULTS: CB2 activates ß-catenin signaling, resulting in the suppression of PPARα/PGC-1α axis. This decreased FAO functions and led to lipid droplet formation in tubular cells. CB2 gene ablation effectively mitigated FAO dysfunction, lipid deposition and uremic toxins accumulation in FAN mice, consequently retarding renal fibrosis. Additionally, inhibition to ß-catenin or PPARα activation could greatly inhibit lipid accumulation and fibrogenesis induced by CB2. CONCLUSIONS: This study highlights CB2 disrupts FAO in tubular cells through ß-catenin activation and subsequent inhibition on PPARα/PGC-1α activity. Targeted inhibition on CB2 offers a perspective therapeutic strategy to fight against renal fibrosis.

Swimming in cold water increases the browning process by diminishing the Myostatin pathway.

BACKGROUND: Brown adipose tissue (BAT) is a thermogenic tissue that uncouples oxidative phosphorylation from ATP synthesis and increases energy expenditure via non-shivering thermogenesis in mammals. Cold exposure and exercise have been shown to increase BAT and browning of white adipose tissue (WAT) in mice. This study aimed to determine whether there is an additive effect of exercise during cold exposure on markers related to browning of adipose tissue. in Wistar rats. METHODS: Twenty-four male Wistar rats were randomly divided into three groups: Control (C, 25˚C), Swimming in Neutral (SN, 30˚C) water, and Swimming in Cold (SC, 15˚C) water. Swimming included intervals of 2-3 min, 1 min rest, until exhausted, three days a week for six weeks, with a training load of 3-6% body weight. After the experimental protocol, interscapular BAT and inguinal subcutaneous white adipose tissue (WAT) were excised, weighed, and processed for beiging marker gene expression. RESULTS: SN and SC resulted in lower body weight gain, associated with reduced WAT and BAT volume and increased BAT number with greater effects observed in SC. Myostatin protein expression was lower in BAT, WAT, soleus muscle, and serum NC and SC compared to the C group. Expression of the interferon regulatory factor-4 (IRF4) gene in both BAT and WAT tissues was significantly greater in the SC than in the C. Expression of the PGC-1α in BAT was significantly increased in the SC compared to C and increased in WAT in NC and SC. Expression of the UCP1 in BAT and WAT increased in the SC group compared to other groups. CONCLUSION: The findings demonstrate that six weeks of swimming training in cold water promotes additive effects of the expression of genes and proteins involved in the browning process of adipose tissue in Wistar rats. Myostatin inhibition may possess a regulator effect on the PGC-1α - UCP1 pathway that mediates adipose tissue browning.

Linagliptin mitigates cisplatin-induced kidney impairment via mitophagy regulation in rats, with emphasis on SIRT-3/PGC-1α, PINK-1 and Parkin-2.

Cisplatin (CDDP) often leads to kidney impairment, limiting its effectiveness in cancer treatment. The lack of mitophagy in proximal tubules exacerbates this issue. Hence, targeting SIRT-3 and PGC1-α shows promise in mitigating CDDP-induced kidney damage. The potential renoprotective effects of linagliptin, however, remain poorly understood. This study represents the first exploration of linagliptin's impact on CDDP-induced kidney impairment in rats, emphasizing its potential role in mitophagic pathways. The experiment involved four rat groups: Group (I) received saline only, Group (II) received a single intraperitoneal injection of CDDP at 6 mg/kg. Groups (III) and (IV) received linagliptin at 6 and 10 mg/kg p.o., respectively, seven days before CDDP administration, continuing for an additional four days. Various parameters, including renal function tests, oxidative stress, TNF-α, IL-1ß, IL-6, PGC-1α, FOXO-3a, p-ERK1, and the gene expression of SIRT-3 and P62 in renal tissue, were assessed. Linagliptin improved renal function, increased antioxidant enzyme activity, and decreased IL-1ß, TNF-α, and IL-6 expression. Additionally, linagliptin significantly upregulated PGC-1α and PINK-1/Parkin-2 expression while downregulating P62 expression. Moreover, linagliptin activated FOXO-3a and SIRT-3, suggesting a potential enhancement of mitophagy. Linagliptin demonstrated a positive impact on various factors related to kidney health in the context of CDDP-induced impairment. These findings suggest a potential role for linagliptin in improving cancer treatment outcomes. Clinical trials are warranted to further investigate and validate its efficacy in a clinical setting.

MicroRNA-148a Targets DNMT1 and PPARGC1A to Regulate the Viability, Proliferation, and Milk Fat Synthesis of Ovine Mammary Epithelial Cells.

In this study, the expression profiles of miR-148a were constructed in eight different ovine tissues, including mammary gland tissue, during six different developmental periods. The effect of miR-148a on the viability, proliferation, and milk fat synthesis of ovine mammary epithelial cells (OMECs) was investigated, and the target relationship of miR-148a with two predicted target genes was verified. The expression of miR-148a exhibited obvious tissue-specific and temporal-specific patterns. miR-148a was expressed in all eight ovine tissues investigated, with the highest expression level in mammary gland tissue (p < 0.05). Additionally, miR-148a was expressed in ovine mammary gland tissue during each of the six developmental periods studied, with its highest level at peak lactation (p < 0.05). The overexpression of miR-148a increased the viability of OMECs, the number and percentage of Edu-labeled positive OMECs, and the expression levels of two cell-proliferation marker genes. miR-148a also increased the percentage of OMECs in the S phase. In contrast, transfection with an miR-148a inhibitor produced the opposite effect compared to the miR-148a mimic. These results indicate that miR-148a promotes the viability and proliferation of OMECs in Small-tailed Han sheep. The miR-148a mimic increased the triglyceride content by 37.78% (p < 0.01) and the expression levels of three milk fat synthesis marker genes in OMECs. However, the miR-148a inhibitor reduced the triglyceride level by 87.11% (p < 0.01). These results suggest that miR-148a promotes milk fat synthesis in OMECs. The dual-luciferase reporter assay showed that miR-148a reduced the luciferase activities of DNA methyltransferase 1 (DNMT1) and peroxisome proliferator-activated receptor gamma coactivator 1-A (PPARGC1A) in wild-type vectors, suggesting that they are target genes of miR-148a. The expression of miR-148a was highly negatively correlated with PPARGC1A (r = -0.789, p < 0.001) in ovine mammary gland tissue, while it had a moderate negative correlation with DNMT1 (r = -0.515, p = 0.029). This is the first study to reveal the molecular mechanisms of miR-148a underlying the viability, proliferation, and milk fat synthesis of OMECs in sheep.

T-2 toxin exposure induces ovarian damage in sows: lncRNA CUFF.253988.1 promotes cell apoptosis by inhibiting the SIRT3/PGC1α pathway.

T-2 toxin, a mycotoxin found in foods and feeds, poses a threat to female reproductive health in both humans and animals. LncRNA CUFF.253988.1 (CUFF.253988.1), highly expressed in pigs, has an undisclosed regulatory role. This study aimed to establish a model of T-2 toxin-induced ovarian injury in sows, both in vivo and in vitro, and to explore the regulatory role and potential mechanisms of CUFF.253988.1. The results showed that feeding T-2 toxin-contaminated feed (1 mg/kg) induced ovarian follicle atresia and mitochondrial structural damage, accompanied by a significant upregulation of CUFF.253988.1 expression in the ovaries. Additionally, T-2 toxin inhibited the SIRT3/PGC1-α pathway associated with mitochondrial function. Moreover, T-2 toxin induced cell apoptosis by upregulating the expression of Cyt c, Bax, cleaved-caspase-9, and cleaved-caspase-3 proteins. In T-2 toxin-induced injury to the ovarian granulosa AVG-16 cells at concentrations of 10, 40 and 160 nM, not only were the previously mentioned effects observed, but also a decrease in mitochondrial membrane potential, ATP content, and an elevation in ROS levels. However, downregulating CUFF.253988.1 reversed T-2 toxin's inhibition of the SIRT3/PGC1-α pathway, alleviating mitochondrial dysfunction and reducing cell apoptosis. Notably, this may be attributed to the inhibition of T-2 toxin-induced enrichment of CUFF.253988.1 in mitochondria. In conclusion, CUFF.253988.1 plays a pivotal role in T-2 toxin-induced ovarian damage, operating through the inhibition of the SIRT3/PGC1-α pathway and promotion of cell apoptosis.

Disturbance in communication between mitochondrial redox processes and the AMPK/PGC-1α/SIRT-1 axis influences diverse organ symptoms in lupus-affected mice.

BACKGROUND: Mechanisms behind multiple organ involvement in lupus, is still an enigma for researchers. Mitochondrial dysfunction and oxidative stress are known to be important aspects in lupus etiology however, their role in lupus organ manifestation is yet to be understood. The present study is based on the understanding of interplay between AMPK/PGC-1α/SIRT-1 axis, mitochondrial complexes, and anti-oxidants levels, which might be involved in lupus organ pathology. METHODOLOGY: Pristane-induced Balb/c mice lupus model (PIL) was utilised and evaluation of anti-oxidants, mitochondrial complexes, pro-inflammatory cytokines levels, biochemical parameters were performed by standard procedures. Tissues were studied by haematoxylin and eosin staining followed by immunohistochemistry. The AMPK/PGC-1α/SIRT-1 expression was analysed by using qPCR and flowcytometry. Analysis of reactive oxygen species (ROS) among WBCs was performed by using various dyes (DCFDA, Mitosox, JC-1) on flowcytometry. RESULT: Significant presence of immune complexes (Tissue sections), ANA (Serum), and pro-inflammatory cytokines (plasma), diminished anti-oxidants and altered biochemical parameters depict the altered pathology in PIL which was accompanied by dysregulated mitochondrial complex activity. Differential expression of the AMPK/PGC-1α/SIRT-1 axis was detected in tissue and correlation with mitochondrial and antioxidant activity emerged as negative in PIL group while positive in controls. Close association was observed between ROS, mitochondrial membrane potential, and AMPK/PGC-1α/SIRT-1 axis in WBCs. CONCLUSION: This study concludes that mitochondria play a dual role in lupus organ pathology, contributing to organ damage while also potentially protecting against damage through the regulation of interactions between antioxidants and the AMPK axis expression.

Skeletal muscle BMAL1 is necessary for transcriptional adaptation of local and peripheral tissues in response to endurance exercise training.

OBJECTIVE: In this investigation, we addressed the contribution of the core circadian clock factor, BMAL1, in skeletal muscle to both acute transcriptional responses to exercise and transcriptional remodeling in response to exercise training. Additionally, we adopted a systems biology approach to investigate how loss of skeletal muscle BMAL1 altered peripheral tissue homeostasis as well as exercise training adaptations in iWAT, liver, heart, and lung of male mice. METHODS: Combining inducible skeletal muscle specific BMAL1 knockout mice, physiological testing and standardized exercise protocols, we performed a multi-omic analysis (transcriptomics, chromatin accessibility and metabolomics) to explore loss of muscle BMAL1 on muscle and peripheral tissue responses to exercise. RESULTS: Muscle-specific BMAL1 knockout mice demonstrated a blunted transcriptional response to acute exercise, characterized by the lack of upregulation of well-established exercise responsive transcription factors including Nr4a3 and Ppargc1a. Six weeks of exercise training in muscle-specific BMAL1 knockout mice induced significantly greater and divergent transcriptomic and metabolomic changes in muscle. Surprisingly, liver, lung, inguinal white adipose and heart showed divergent exercise training transcriptomes with less than 5% of 'exercise-training' responsive genes shared for each tissue between genotypes. CONCLUSIONS: Our investigation has uncovered the critical role that BMAL1 plays in skeletal muscle as a key regulator of gene expression programs for both acute exercise and training adaptations. In addition, our work has uncovered the significant impact that altered exercise response in muscle and its likely impact on the system plays in the peripheral tissue adaptations to exercise training. Our work also demonstrates that if the muscle adaptations diverge to a more maladaptive state this is linked to increased gene expression signatures of inflammation across many tissues. Understanding the molecular targets and pathways contributing to health vs. maladaptive exercise adaptations will be critical for the next stage of therapeutic design for exercise mimetics.