Gliomas are the most common primary brain tumors in adults. Despite multidisciplinary treatment approaches, the survival rates for patients with malignant glioma have only improved marginally, and few prognostic biomarkers have been identified. Peroxisome proliferator-activated receptor γ (PPARγ) coactivator-1α (PGC-1α) is a crucial regulator of cancer metabolism, playing a vital role in cancer cell adaptation to fluctuating energy demands. In this study, the clinicopathological roles of PGC-1α in gliomas were evaluated. Employing immunohistochemistry, cell culture, siRNA transfection, cell viability assays, western blot analyses, and in vitro and in vivo invasion and migration assays, we explored the functions of PGC-1α in glioma progression. High PGC-1α expression was significantly associated with an advanced pathological stage in patients with glioma and with poorer overall survival. The downregulation of PGC-1α inhibited glioma cell proliferation, invasion, and migration and altered the expression of oncogenic markers. These results conclusively demonstrated that PGC-1α plays a critical role in maintaining the malignant phenotype of glioma cells and indicated that targeting PGC-1α could be an effective strategy to curb glioma progression and improve patient survival outcomes.

Chronic exposure to arsenic in drinking-water damage to cognitive function, and nerve cells apoptosis is one of primary characteristic. The damage of mitochondrial structure and/or function is one of the main characteristics of apoptosis. Peroxisome proliferator activated receptor γ Coactivator α (PGC-1α) is involved in the regulation of mitochondrial biogenesis, energy metabolism and apoptosis. In this study, we aimed to study role of PGC-1α in sodium arsenite (NaAsO2)-induced mitochondrial apoptosis in rat hippocampal cells. We discovered that arsenic-induced apoptosis increased in rat hippocampus increased with NaAsO2 (0, 2, 10, and 50 mg/L, orally via drinking water for 12 weeks) exposure by TUNEL assay, and the structure of mitochondria was incomplete, swollen, lysosomes and lipofuscin increasing, and nuclear membrane shrunk observed by transmission electron microscope. Furthermore, NaAsO2 reduced levels of Bcl-2 and PGC-1α, increased the levels of Bax and Cytochrome C expression. Moreover, correlation analysis showed that brain arsenic content was negatively correlated with PGC-1α level and brain ATP content, respectively; PGC-1α level was negatively correlated with apoptosis rate; Brain ATP content was positively correlated with PGC-1α level; but no significant correlation between ATP content and apoptosis has been observed in this study. Taken together, the results of present study indicate that NaAsO2-induced mitochondrial pathway apoptosis is related to the reduction of PGC-1α, accompanied by ATP depletion.

Local cryotherapy is widely used as a treatment for sports-related skeletal muscle injury. However, its molecular mechanisms are unknown. To clarify these mechanisms, in this study, we applied one to three 15-min cold stimulations at 4 °C to various cell lines (in vitro), the tibialis anterior (TA) muscle (ex vivo), and mouse limbs (in vivo). In the in vitro assay, cAMP response element-binding protein 1 (CREB1) was markedly phosphorylated (as pCREB1) and CREB-binding protein (CBP) was recruited to pCREB-1 in response to two or three cold stimulations. In a reporter assay with the cAMP-responsive element, the signals significantly increased after two to three cold stimulations at 4 °C. In the ex vivo study, CREB-targeting genes were significantly upregulated following two or three cold stimulations. The in vivo experiment disclosed that cold stimulation of a mouse limb for 9 days significantly increased mitochondrial DNA copy number and upregulated genes such as Pgc-1α involved in mitochondrial biogenesis. The foregoing results suggest that local cryotherapy increases CREB transcription and upregulates CREB-targeting genes in a manner dependent on cold stimulation frequency and duration. This information may serve as an impetus for further investigations into local cryotherapy as a treatment for sports-related skeletal muscle trauma.

Epigenetic changes are a hallmark of short- and long-term transcriptional regulation, and hence instrumental in the control of cellular identity and plasticity. Epigenetic mechanisms leading to changes in chromatin structure, accessibility for recruitment of transcriptional complexes, and interaction of enhancers and promoters all contribute to acute and chronic adaptations of cells, tissues and organs to internal and external perturbations. Similarly, the peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) is activated by stimuli that alter the cellular energetic demand, and subsequently controls complex transcriptional networks responsible for cellular plasticity. It thus is of no surprise that PGC-1α is under the control of epigenetic mechanisms, and constitutes a mediator of epigenetic changes in various tissues and contexts. In this review, we summarize the current knowledge of the link between epigenetics and PGC-1α in health and disease.

Liver fibrosis is a critical health issue with limited treatment options. This study investigates the potential of PGC-Sec, a secretome derived from PGC-1α-overexpressing adipose-derived stem cells (ASCs), as a novel therapeutic strategy for liver fibrosis. Upon achieving a cellular confluence of 70-80%, ASCs were transfected with pcDNA-PGC-1α. PGC-Sec, obtained through concentration of conditioned media using ultrafiltration units with a 3-kDa cutoff, was assessed through in vitro assays and in vivo mouse models. In vitro, PGC-Sec significantly reduced LX2 human hepatic stellate cell proliferation and mitigated mitochondrial oxidative stress compared to control-secretome (Ctrl-Sec). In an in vivo mouse model, PGC-Sec treatment led to notable reductions in hepatic enzyme activity, serum pro-inflammatory cytokine concentrations, and fibrosis-related marker expression. Histological analysis demonstrated improved liver histology and reduced fibrosis severity in PGC-Sec-treated mice. Immunohistochemical staining confirmed enhanced expression of PGC-1α, OPA1 (a mitochondrial function marker), and PPARα (an anti-fibrogenic marker) in the PGC-Sec-treated group, along with reduced Collagen 1A expression (a pro-fibrogenic marker). These findings highlight the therapeutic potential of PGC-Sec in combating liver fibrosis by enhancing mitochondrial biogenesis and function, and promoting antifibrotic processes. PGC-Sec holds promise as a novel treatment strategy for liver fibrosis.

Angiogenesis is a hallmark of ovarian cancer (OC) it promotes rapid cell growth and the associated metastasis. Identifying new bioactive compounds to target angiogenesis may provide valuable paradigms as therapeutic strategies. Melatonin is a well-characterized indoleamine that possesses important anti-angiogenic properties in a set of aggressive solid tumors. Herein, we evaluated the role of melatonin therapy on the angiogenic signaling pathway in OC of an ethanol-preferring rat model that mimics the same pathophysiological conditions occurring in women. OC was chemically induced with a single injection of 7,12-dimethylbenz(a)anthracene (DMBA) under the ovarian bursa. After the rats developed serous papillary OC, half of the animals received i.p. injections of melatonin (200 µg/100 g body weight/day) for 60 days. Serum levels of melatonin were higher following therapy, and the expression of its receptor MT1R was significantly increased in OC-bearing rats, regardless of ethanol intake. TGFB1, a transforming growth factor-beta1, was reduced only after melatonin treatment. Importantly, vascular endothelial growth factor (VEGF) was severely reduced after melatonin therapy in animals given or not given ethanol. Conversely, the levels of VEGF receptor 1 (VEGFR1) was diminished after ethanol consumption, regardless of melatonin therapy, and VEGFR2 was only reduced following melatonin. Hypoxia-inducible factor (HIF)-1α was augmented with ethanol consumption, and notably, melatonin significantly reduced their levels. Collectively, our results suggest that melatonin attenuates angiogenesis in OC of an animal model of ethanol consumption; this provides a possible complementary therapeutic opportunity for concurrent OC chemotherapy.

Cytochrome-c-oxidase (COX) subunit 4 (COX4) plays important roles in the function, assembly and regulation of COX (mitochondrial respiratory complex 4), the terminal electron acceptor of the oxidative phosphorylation (OXPHOS) system. The principal COX4 isoform, COX4-1, is expressed in all tissues, whereas COX4-2 is mainly expressed in the lungs, or under hypoxia and other stress conditions. We have previously described a patient with a COX4-1 defect with a relatively mild presentation compared to other primary COX deficiencies, and hypothesized that this could be the result of compensatory upregulation of COX4-2. To this end, COX4-1 was downregulated by shRNAs in human foreskin fibroblasts (HFF), and compared to patient's cells. COX4-1, COX4-2 and HIF-1α were detected by immunocytochemistry. The mRNA transcripts of both COX4 isoforms and HIF-1 target genes were carried out by RT-qPCR. COX activity and OXPHOS function were measured by enzymatic and oxygen consumption assays, respectively. Pathways were analyzed by CEL-Seq2 and by RT-qPCR. We demonstrate elevated COX4-2 levels in the COX4-1-deficient cells with a concomitant HIF-1α stabilization, nuclear localization and upregulated hypoxia and glycolysis pathways. We suggest that COX4-2 and HIF-1α has the are upregulated, also in normoxia as a compensatory mechanism in COX4-1 deficiency.

Inhalational anesthetics was previously reported to suppress glioma cell malignancy, but underlying mechanisms remain unclear. The present study aims to investigate the effects of sevoflurane and desflurane on glioma cell malignancy changes via microRNA (miRNA) modulation. The cultured H4 cells were exposed to 3.6% sevoflurane or 10.3% desflurane for 2 hrs. The miR-138, -210 and -335 expression were determined with qRT-PCR. Cell proliferation and migration were assessed with wound healing assay, Ki67 staining and cell count kit 8 (CCK8) assay with/without miR-138/-210/-335 inhibitor transfections. The miRNA downstream proteins, hypoxia inducible factor-1α (HIF-1α) and matrix metalloproteinase 9 (MMP9), were also determined with immunofluorescent staining. Sevoflurane and desflurane exposure to glioma cells inhibited their proliferation and migration. Sevoflurane exposure increased miR-210 expression whereas desflurane exposure upregulated both miR-138 and miR-335 expressions. The administration of inhibitor of miR-138, -210 or -335 inhibited the suppressing effects of sevoflurane or desflurane on cell proliferation and migration, in line with the HIF-1α and MMP9 expression changes. These data indicated that inhalational anesthetics, sevoflurane and desflurane, inhibited glioma cell malignancy via miRNA upregulation and their downstream effectors, HIF-1α and MMP9, downregulation. The implication of the current study warrants further study.

HIF-1α is a master regulator of oxygen homeostasis involved in different stages of cancer development. Thus, HIF-1α inhibition represents an interesting target for anti-cancer therapy. It was recently shown that HIF-1α interaction with NQO1 inhibits its proteasomal degradation, thus suggesting that targeting the stability of NQO1 could led to destabilization of HIF-1α as a therapeutic approach. Since the molecular interactions of NQO1 with HIF-1α are beginning to be unraveled, we review here our current knowledge on the intracellular functions and stability of NQO1, its pharmacological modulation by small ligands, and the molecular determinants of its roles as a chaperone of many different proteins including cancer-associated factors such as p53 and p73α. This knowledge is then discussed in the context of potentially targeting the intracellular stability of HIF-1α by acting on its chaperone, NQO1. This could result in novel anti-cancer therapies.

Epithelial-mesenchymal transition (EMT) is a cellular biological process involved in migration of primary cancer cells to secondary sites facilitating metastasis. Besides, EMT also confers properties such as stemness, drug resistance and immune evasion which can aid a successful colonization at the distant site. EMT is not a binary process; recent evidence suggests that cells in partial EMT or hybrid E/M phenotype(s) can have enhanced stemness and drug resistance as compared to those undergoing a complete EMT. Moreover, partial EMT enables collective migration of cells as clusters of circulating tumor cells or emboli, further endorsing that cells in hybrid E/M phenotypes may be the ‘fittest’ for metastasis. Here, we review mechanisms and implications of hybrid E/M phenotypes, including their reported association with hypoxia. Hypoxia-driven activation of HIF-1α can drive EMT. In addition, cyclic hypoxia, as compared to acute or chronic hypoxia, shows the highest levels of active HIF-1α and can augment cancer aggressiveness to a greater extent, including enriching for a partial EMT phenotype. We also discuss how metastasis is influenced by hypoxia, partial EMT and collective cell migration, and call for a better understanding of interconnections among these mechanisms. We discuss the known regulators of hypoxia, hybrid EMT and collective cell migration and highlight the gaps which needs to be filled for connecting these three axes which will increase our understanding of dynamics of metastasis and help control it more effectively.

Theaflavins, the characteristic and bioactive polyphenols in black tea, possess the potential improvement effects on insulin resistance-associated metabolic abnormalities including obesity and type 2 diebetes. However, the molecular mechanisms of theaflavins improving insulin sensitivity are still not clear. In this study, we investigated the protective effects and mechanisms of theaflavins on palmitic acid-induced insulin resistance in HepG2 cells. Theaflavins could significantly increase glucose uptake of insulin-resistant cells at noncytotoxic doses. This activity was mediated by upregulating the glucose transporter 4 protein expression, increasing the phosphorylation of IRS-1 at Ser307, and reduced the phosphor-Akt (Ser473) level. Moreover, theaflavins were found to enhance mitochondrial DNA copy number through down-regulate the PGC-1β mRNA level and up-regulate PRC mRNA expression in insulin-resistant HepG2 cells. These results indicated that theaflavins could improve free fatty acid-induced hepatic insulin resistance by promoting mitochondrial biogenesis, and were promising functional food and medicines for insulin resistance-related disorders.

Ischemic neuron loss contributes to brain dysfunction in patients with cardiac arrest (CA). Histidine–tryptophan–ketoglutarate (HTK) solution is a preservative used during organ transplantation. Can HTK also protect neurons from severe hypoxia (SH) following CA? We isolated rat primary cortical neurons and induced SH with or without HTK. Changes in caspase-3, hypoxia-inducible factor 1-alpha (HIF-1α), and NADPH oxidase-4 (NOX4) expression were evaluated at different time points till 72 h. Using a rat asphyxia model, we induced CA-mediated brain damage and then completed resuscitation. HTK or sterile saline was administered into the left carotid artery. Neurological deficit scoring and mortality were evaluated for 3 days. Then the rats were sacrificed for evaluating NOX4 and H2O2 level in blood and brain. In the in vitro study, HTK attenuated SH- and H2O2-mediated cytotoxicity in a volume- and time-dependent manner, associated with persisted HIF-1α expression, reductions in procaspase-3 activation and NOX4 expression. The inhibition of HIF-1α abrogated HTK’s effect on NOX4. In the in vivo study, neurological scores were significantly improved by HTK. H2O2 level, NOX4 activity and NOX4 gene expression were all decreased in the brain specimen of HTK-treated rats. Our results suggest that HTK acts as an effective neuroprotective solution.

Obesity and metabolic syndrome involve chronic low-grade inflammation called metabolic inflammation as well as metabolic derangements from increased endotoxin and free fatty acids. It is debated whether the endoplasmic reticulum (ER) stress in monocytic cells can contribute to amplify metabolic inflammation; if so, by which mechanism(s). To test this, metabolic stress was induced in THP-1 monocytic cells by treatments with lipopolysaccharide (LPS), palmitic acid (PA), or oleic acid (OA), in the presence or absence of ER stressor thapsigargin (TG). Gene expression of tumor necrosis factor (TNF)-α and markers of ER/oxidative stress was determined by qRT-PCR, TNF-α protein by ELISA, ROS by DCFH-DA assay, HIF-1α/p38/ERK-1,2/NF-κB phosphorylation by immunoblotting, and insulin sensitivity by glucose-uptake assay. Regarding clinical analyses, adipose TNF-α was assessed by qRT-PCR/IHC and plasma TNF-α/hs-CRP/MDA/OX-LDL by ELISA. We found that the cooperative interaction between metabolic and ER stresses promoted TNF-α, ROS, CHOP, ATF6, SOD2, and NRF2 expression (P≤0.0183),. However, glucose uptake was not impaired. TNF-α amplification was dependent on HIF-1α/p38/NF-κB phosphorylation, while MAPK/NF-κB inhibitors and antioxidants/ROS scavengers attenuated TNF-α production (P≤0.05). Individuals with obesity displayed increased adipose TNF-α gene/protein expression as well as elevated plasma levels of TNF-α, CRP, MDA, and OX-LDL (P≤0.05). Our findings support a cooperative interaction between metabolic and ER stresses, favoring inflammation by triggering TNF-α production via the ROS/CHOP/HIF-1α and MAPK/NF-κB dependent mechanisms. This study also shows the therapeutic potential of ROS scavengers/anti-oxidants in inflammatory conditions involving metabolic/ER stresses.

The hypoxia signalling pathway enables adaptation of cells to decreased oxygen availability. When oxygen becomes limiting, the central transcription factors of the pathway, hypoxia-inducible factors (HIFs), are stabilised and activated to induce the expression of hypoxia-regulated genes, thereby maintaining cellular homeostasis. Whilst hydroxylation has been thoroughly described as the major and canonical modification of the HIF-α subunits, regulating both HIF stability and activity, a range of other post-translational modifications decorating the entire protein play also a crucial role in altering HIF localisation, stability, and activity. These modifications, their conservation throughout evolution and their effects on HIF-dependent signalling are discussed in this review.

Background: The immunomodulatory role of 1,25-Dihydroxy vitamin D3 (1,25(OH)2D3) is exerted through its interaction with the Vitamin D receptor (VDR) present on pancreatic and immune cells. While a deficiency in Vitamin D has been linked to Type 1 Diabetes Mellitus (T1DM), the exact molecular mechanism driving this down-regulation in T1DM is yet to be fully understood. This study aimed to decipher differences in the expression of genes associated with Vitamin D metabolism in T1DM patients and to ascertain if there is a correlation between serum 1,25(OH)2D3 levels and the expression of these genes. We also sought to understand the influence of specific microRNAs (miRNAs) on the expression of Vitamin D metabolism genes in peripheral blood mononuclear cells (PBMCs) of T1DM patients. Furthermore, the study delved into the potential implications of altered Vitamin D metabolism genes and miRNAs on autoimmune processes. Methods: Utilizing real-time PCR, we assessed the expression profiles of genes encoding for 1-hydroxylases (CYP27B1) and 24-hydroxylases (CYP24A1), as well as related miRNAs, in PBMCs from 30 T1DM patients and 23 healthy controls. ELISA tests facilitated the measurement of 1,25(OH)2D3, GAD65, and IA-2 levels. Results: Our findings showcased down-regulated CYP27B1 mRNA levels, while CYP24A1 expression remained stable compared to healthy subjects (CYP27B1, p = 0.0005; CYP24A1, p = 0.205, respectively). In T1DM patients, the levels of has-miR-216b-5p were found to be increased, while the levels of has-miR-21-5p were decreased in comparison to the control group. Notably, no correlation was identified between the expression of CYP27B1 in T1DM patients and the levels of has-miR-216b-5p, has-miR-21-5p, and 1,25(OH)2D3. A significant negative correlation was identified between CYP27B1 mRNA levels in PBMCs of T1DM and IA2, but not with GAD65. Conclusions: The study highlights there were reduced levels of both CYP27B1 mRNA and has-miR-21-5p, along with elevated levels of has-miR-216b-5p in the PBMCs of T1DM. However, the absence of a correlation between the expression of CYP27B1, levels of has-miR-216b-5p, and the status of 1,25(OH)2D3 suggests the possible existence of other regulatory mechanisms. Additionally, the inverse relationship between IA2 autoantibodies and CYP27B1 expression in T1DM patients indicates a potential connection between this gene and the autoimmune processes inherent in T1DM.

Dysregulation of cartilage homeostasis and the changes in the density and the architecture of the subchondral bone were postulated as a potent mechanically pathological activity contributing to osteoarthritis (OA) pathogenesis. Extracorporeal shockwave therapy (ESWT) is a new, none invasive and effective method in the treatment of animal OA model. In the current study, we demonstrated that shockwave induced the expression of protein-disulfide isomerase-associated 3 (Pdia-3) which is a multifunctional protein hypothesized to be a significant mediator for 1α,25-Dihydroxyvitamin D3 (1α,25(OH)₂D₃) signaling pathway using two-dimensional electrophoresis. Histological analysis and quantitative polymerase chain reaction (qPCR) were verified and observed that the expression of Pdia-3 at 2 weeks was significantly higher than that of any other group at 4 weeks, 8 weeks, and 12 weeks post-shockwave treatment in early OA knee of rat. The other factors of the 1α,25(OH)₂D₃ rapid membrane signaling pathway including extracellular signal-regulated protein kinases 1 (ERK1), osteopontin (OPG), alkaline phosphatase (ALP), and matrix metallopeptidase 13 (MMP13) were measured and significantly increased by qPCR at 2 weeks post-shockwave treatment in early OA knee. Our proteomic data revealed significant Pdia-3 expression in microenvironments of joint tissue that could be actively responded to ESWT, which may potentially regulate biological function of chondrocytes and osteoblasts in the treatment of OA knee.

We previously showed that mice with knockout in the peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A) gene encoding the PGC-1a protein and nuclear factor erythroid 2 like 2 (NFE2L2) gene, showed some features of the age-related macular degeneration (AMD) phenotype. To further explore the mechanism behind the involvement of PGC-1a in AMD pathogenesis we used young (3-month) and old (12-month) mice with knockout in the PPARGC1A gene and age-matched wild-type (WT) animals. An immunohistochemical analysis showed age-dependent different expression of markers of oxidative stress defense, senescence and autophagy in the retinal pigment epithelium of KO animals as compared with their WT counterparts. Multivariate inference testing showed that senescence and autophagy proteins had the greatest impact on the discrimination between KO and WT 3-month animals, but proteins of antioxidant defense also contributed to that discrimination. A bioinformatic analysis showed that PGC-1a might coordinate the interplay between genes encoding proteins involved in antioxidant defense, senescence and autophagy in the aging retina. These data support importance of PGC-1a in AMD pathogenesis and confirm the utility of mice with PGC-1a knockout as an animal model to study AMD pathogenesis.

Susceptibility to photoimmune suppression and photocarcinogenesis is greater in male than in female humans and mice and is exacerbated in female estrogen receptor-beta knockout (ER-β-/-) mice. We previously reported that the active vitamin D hormone, 1,25-dihydroxyvitamin D3 (1,25(OH)2D) applied topically protects against ultraviolet radiation (UV)-induction of cutaneous cyclobutane pyrimidine dimers (CPDs) and suppression of contact hypersensitivity (CHS) in female mice. Here we compare these responses in female versus male Skh:hr1 mice, in ER-β-/- versus wild type C57BL/6 mice, and in female ER-blockaded Skh:hr1 mice. Induction of CPDs was significantly greater in male than female Skh:hr1 mice and was more effectively reduced by 1,25(OH)2D in female Skh:hr1 and C57BL/6 mice, than in male Skh:hr1 or ER-β-/- mice respectively. This correlated with reduced sunburn inflammation by 1,25(OH)2D in female but not male Skh:hr1 mice. Furthermore, although 1,25(OH)2D alone dose-dependently suppressed basal CHS responses in male Skh:hr1 and ER-β-/- mice, UV-induced immunosuppression was universally observed. In female Skh:hr1 and C57BL/6 mice, the immunosuppression was decreased by 1,25(OH)2D dose-dependently, but not in male Skh:hr1, ER-β-/- or ER-blockaded mice. These results reveal a sex bias in genetic, inflammatory and immune photoprotection by 1,25(OH)2D favoring female mice, that is dependent on the presence of ER-β.

Inflammatory processes play major roles in carcinogenesis and progression of hepatocellular carcinoma (HCC) derived from non-alcoholic steatohepatitis (NASH). But there are no therapies for NASH related HCC, especially focusing on these critical steps. Previous studies reported that farnesyltransferase inhibitors (FTIs) have anti-inflammatory and anti-tumor effects. However, the influence of FTIs on NASH-related HCC has not been elucidated. In HCC cell lines, HepG2, Hep3B, and Huh-7, we confirmed expression of hypoxia-inducible factor (HIF)-1α, an accelerator of tumor aggressiveness and the inflammatory response. We established NASH-related HCC models under inflammation and free fatty acid burden and confirmed that HIF-1α expression was increased under both conditions. Tipifarnib, which is an FTI, strongly suppressed increased HIF-1α, inhibited cell proliferation, and induced apoptosis. Simultaneously, intracellular interleukin-6 as an inflammation marker was increased under both conditions and significantly suppressed by tipifarnib. Additionally, tipifarnib suppressed expression of phosphorylated nuclear factor-κB and transforming growth factor-β. Finally, in a NASH-related HCC mouse model burdened with diethylnitrosamine and a high fat diet, tipifarnib significantly reduced tumor nodule formation in association with decreased serum interleukin-6. In conclusion, tipifarnib has anti-tumor and anti-inflammatory effects in a NASH-related HCC model and may be a promising new agent to treat this disease.