FoxO1 mRNA Research Articles

FoxO1 in Micropterus salmoides: Molecular characterization and its roles in glucose metabolism by glucose or insulin-glucose loading

Forkhead box O1 (FoxO1), a nuclear transcription factor, plays an important role in insulin-mediated glucose metabolism. In this study, FoxO1 gene from largemouth bass (Micropterus salmoides) was cloned and characterized, and its effects on hepatic glucose metabolism regulated by insulin-AKT pathway were investigated in response to glucose or insulin-glucose injection. The full-length cDNA of FoxO1 consisted of 2541 bp and encoded 680 amino acids. Sequence alignments and phylogenetic analysis revealed that FoxO1 exhibited a high degree of conservation among teleost, retaining one forkhead domain, one transactivation domain, and three phosphorylation sites. FoxO1 mRNA was expressed in a wide range of tissues, and high in the brain and liver. Glucose loading resulted in persistent hyperglycemia, and plasma insulin levels remained unchanged except at 1 h. After the insulin-glucose injection, insulin levels were significantly elevated and glucose levels recovered to the basal value after 6 h, which indicated insufficient insulin secretion caused persistent hyperglycemia in this species. Compared with the glucose injection group, transcript levels and enzyme activities of hepatic glycolysis-related genes (GK and PK) were significantly activated, and gluconeogenesis-related genes (PEPCK and G6Pase) were significantly depressed at 3 h after the insulin-glucose injection. Besides, phosphorylation of AKT-FoxO1 pathway was significantly activated. Therefore, insulin improved glucose metabolism by activating the AKT-FoxO1 phosphorylation to decrease hyperglycemia stress after the meal, which indicated insufficient insulin secretion was the reason for glucose intolerance in largemouth bass. Meanwhile, conserved S267 and S329 phosphorylation sites of FoxO1 were confirmed to be regulated by AKT and mediated the glucose metabolism. In conclusion, activation of insulin-AKT-FoxO1 pathway improved glucose tolerance through mediating glucose metabolism in largemouth bass.

Saponins of Momordica charantia increase insulin secretion in INS-1 pancreatic β-cells via the PI3K/Akt/FoxO1 signaling pathway

Saponins are the main bioactive substances with anti-hyperglycemic activities of Momordica charantia. This study aimed to verify the effects of M. charantia saponins on insulin secretion and explore the potential underlying mechanisms in INS-1 pancreatic β-cells. We injured INS-1 cells with 33.3mM glucose and then treated them with saponins. Saponins improved cell morphology and viability as demonstrated by inverted microscopy and CCK8 detection and significantly increased insulin secretion in a concentration-dependent manner as shown by ELISA. Thus, we obtained the optimal concentration for the subsequent experiments. Potential mechanisms were explored by immunofluorescence, western blotting, and RT-qPCR techniques. First, saponins increased the mRNA and protein levels of IRS-2 but decreased the serine 731 phosphorylation level of IRS-2. Moreover, saponins increased the phosphorylation of Akt protein and decreased the protein level of FoxO1, which were both reversed by the PI3K inhibitor ly294002. Furthermore, saponins increased the protein level of the downstream molecule and insulin initiating factor PDX-1, which was also reversed by ly294002. Saponins also increased Akt and PDX-1 mRNA and decreased FoxO1 mRNA, which were both reversed by ly294002. Saponins increased glucose-stimulated insulin secretion (GSIS) and intracellular insulin content, which were reversed by ly294002, as determined by ELISA. The immunofluorescence results also confirmed this tendency. In conclusion, our findings improve our understanding of the function of saponins in INS-1 pancreatic β-cells and suggest that saponins may increase insulin secretion via the PI3K/Akt/FoxO1 signaling pathway.

Downregulation of FOXO4 promotes neuronal survival by mediating oxidative-stress–induced apoptosis after cerebral ischemia/reperfusion injury

Purpose: To investigate the effect of FOXO4 on cerebral ischemia/reperfusion (CIR) injury and the underlying mechanism.Methods: An in vitro ischemia/reperfusion (IR) model was achieved using oxygen-glucose deprivation/reoxygenation (OGD/R). Expression of RNA and protein was determined using quantitative real time polymerase chain reaction (qRT-PCR) and western blotting, respectively. Cell viability and apoptosis were determined using MTT assay and flow cytometry, respectively. Commercial kits were used to measure lactate dehydrogenase (LDH), reactive oxygen species (ROS), chloramphenicol acetyltransferase (CAT), malondialdehyde (MDA), and superoxide dismutase (SOD).Results: Following OGD/R, FOXO4 mRNA and protein expressions were upregulated in SH-SY5H human neuroblastoma cells. ODG/R reduced cell proliferation and increased the proportion of apoptotic cells, and these effects were inhibited by knockdown of FOXO4 (p < 0.05). Levels of cleaved caspase 3 and cleaved poly(ADP-ribose) polymerases (PARPs) were increased after ODG/R and these increaseswere inhibited by FOXO4 knockdown. ROS content and levels of LDH and MDA were increased after ODG/R and decreased by knockdown of FOXO4 (p < 0.05). Levels of CAT and SOD were reduced after ODG/R, and this reduction was reversed by knockdown of FOXO4 (p < 0.05).Conclusion: The results demonstrate that knockdown of FOXO4 promotes cell proliferation and inhibits cellular apoptosis via reduction of oxidative stress after CIR injury, indicating a new therapeutic target for the treatment of CIR injury.
 Keywords: FOXO4, Neuronal survival, Oxidative stress, Cerebral ischemia/reperfusion injury

Altered mRNA expression levels of autophagy- and apoptosis-related genes in the FOXO pathway in schizophrenia patients treated with olanzapine

This study attempted to analyze the alterations in the mRNA expression levels of autophagy- and apoptosis-related genes in the forkhead box transcription factor O (FOXO) pathway in schizophrenia patients before and after olanzapine treatment. For a total of 32 acute schizophrenic inpatients, clinical data with PANSS were obtained before and after four weeks of olanzapine treatment (mean dose 14.24 ± 4.35 mg/d) along with data from 32 healthy volunteers. The mRNA expression levels of the FOXO pathway genes were measured by real-time qPCR after fasting venous blood was collected and analyzed. The mRNA expression levels of FOXO1, FOXO3A, FASLG, and BCL2L11 were observed to be significantly decreased in acute schizophrenia patients. After four weeks of olanzapine treatment, the expression levels of the first three genes were further reduced, but BCL2L11 expression levels were not significantly changed. The pairwise correlations between the mRNA expression level of FASLG and those of the other three genes were not observed in acute schizophrenia patients, while these relationships were observed in healthy controls. After olanzapine treatment, the FASLG mRNA expression level was restored and exhibited a pairwise correlation with the FOXO3A and BCL2L11 mRNA expression levels but not with the FOXO1 mRNA expression level, and FASLG mRNA expression was also correlated with the duration of the disease. The statuses and correlations of the mRNA expression levels of FOXO pathway-related genes were altered in schizophrenia patients and were affected by olanzapine treatment and the duration of the disease.

Pueraria lobata root polysaccharide alleviates glucose and lipid metabolic dysfunction in diabetic db/db mice

Context Pueraria lobata (Willd.) Ohwi (Fabaceae) root extract can lower blood glucose levels; however, whether Pueraria lobata root polysaccharide (PLP) possesses these effects is still unknown. Objective This study evaluates the therapeutic effect of PLP on diabetic metabolic syndrome. Materials and methods The db/m mice were assigned to normal control group (NC), db/db mice were divided into four groups randomly (n = 8). The db/db mice received rosiglitazone (10 mg/kg BW) or PLP (100 or 200 mg/kg BW) via oral gavage for 6 weeks. Afterward, blood glucose, insulin, and glycogen content were assayed, and insulin tolerance test (ITT), oral glucose tolerance test (OGTT) were performed. Glucose and lipid metabolism-related parameters and gene expression levels were assayed by ELISA and RT-PCR, respectively. Results After treatment with HPLP, the values of body weight, epididymal fat, subcutaneous fat, fasting blood glucose, insulin, and HOMA-IR decreased to 45.89 ± 1.66 g, 1.65 ± 0.14 g, 1.97 ± 0.16 g, 14.84 ± 1.52 mM, 9.35 ± 0.98 mU/L, and 5.56 ± 1.26, respectively; the levels of TG, TC, LDL-C, and FFA decreased to 1.67 ± 0.11 mmol/L, 6.23 ± 0.76 mmol/L, 1.29 ± 0.07 mmol/L, and 1.71 ± 0.16 mmol/L, respectively. HPLP down-regulated PEPCK, G6PC, FOXO1, SREBP-1, and ACC mRNA expression (p < 0.01), and up-regulated GS, Akt2, PI3K, GLUT2, PPARα, and LDLR mRNA expression in the liver (p < 0.01). Discussion and conclusion PLP exerts antidiabetic effects via activating the PI3K/AKT signalling pathway, thus improving insulin resistance, glucose, and lipid metabolism in db/db mice. Thus, PLP may be considered as a potential antidiabetic agent in clinical therapy.

Fasting and fasting mimetic supplementation address sirtuin expression, miRNA and microbiota composition

Background: Fasting and fasting mimetics - bioactive compounds mimicking fasting effects, are of growing interest as potential means to slow down the aging process and increase health span. Sirtuins are known as enzymes that interfere with mitochondrial energy metabolism and molecular pathways involved in longevity. Although their activation is determined as a response to stress i.e. caloric restriction. Sirtuin activating nutraceuticals are believed to mimic the effects of nutrient deprivation, thus activating signaling pathways correlated to an improved health span. In this study, we compare 5 days periodic buchinger fasting intervention with 3 months shot supplementation, a drink formula, containing secondary plant ingredients considered to activate sirtuins.Methods: We analyzed pathways in response to fasting and a sirtuins activating drink. Genetic and epigenetic biomarkers including telomere length, LINE1 methylation, and a set of mRNAs and miRNAs were assessed using qPCR analysis. Gut composition and metabolites were compared using Illumnia sequencing and mass spectrometry.Results: Fasting, but also the fasting mimetic could increase expression of FoxO1, SIRT1, and MLH1 mRNA, all genes discussed in aspects of longevity. A positive correlation between telomere length and both SIRT1, and SIRT6 was observed. Furthermore, a significant change in the gut composition was measured. Actinobacteria increased in the supplementation group, whereas after buchinger fasting a rise in the distribution of Proteobacteria could be observed. Firmicutes/Bacteroidetes ratio decreased and correlated with the body mass index (BMI).Conclusions: Our results confirm the effects of fasting on longevity associated mechanisms but also suggest that SIRTFOOD shot intervention addresses some of these effects.

Saponins of Momordica charantia increase insulin secretion in INS-1 pancreatic β-cells via the PI3K/Akt/FoxO1 signaling pathway

Saponins are the main bioactive substances with anti-hyperglycemic activities of Momordica charantia. This study aimed to verify the effects of M. charantia saponins on insulin secretion and explore the potential underlying mechanisms in INS-1 pancreatic β-cells. We injured INS-1 cells with 33.3mM glucose and then treated them with saponins. Saponins improved cell morphology and viability as demonstrated by inverted microscopy and CCK8 detection and significantly increased insulin secretion in a concentration-dependent manner as shown by ELISA. Thus, we obtained the optimal concentration for the subsequent experiments. Potential mechanisms were explored by immunofluorescence, western blotting, and RT-qPCR techniques. First, saponins increased the mRNA and protein levels of IRS-2 but decreased the serine 731 phosphorylation level of IRS-2. Moreover, saponins increased the phosphorylation of Akt protein and decreased the protein level of FoxO1, which were both reversed by the PI3K inhibitor ly294002. Furthermore, saponins increased the protein level of the downstream molecule and insulin initiating factor PDX-1, which was also reversed by ly294002. Saponins also increased Akt and PDX-1 mRNA and decreased FoxO1 mRNA, which were both reversed by ly294002. Saponins increased glucose-stimulated insulin secretion (GSIS) and intracellular insulin content, which were reversed by ly294002, as determined by ELISA. The immunofluorescence results also confirmed this tendency. In conclusion, our findings improve our understanding of the function of saponins in INS-1 pancreatic β-cells and suggest that saponins may increase insulin secretion via the PI3K/Akt/FoxO1 signaling pathway.

Fermented Feed Modulates Meat Quality and Promotes the Growth of Longissimus Thoracis of Late-Finishing Pigs.

Simple SummaryLittle is known about the effect of fermented feed on lean mass production of finishing pigs and the underlying mechanism. This study aimed to investigate the effect of fermented diet on growth performance, carcass traits, meat quality and growth of longissimus thoracis (LT) of finishing pigs. Our results found that fermented diet significantly increased loin eye area and lean mass percentage, decreased backfat thickness and improved meat quality of LT by decreasing shear force and drip loss at 48 h post slaughter and improving meat sensory characteristics compared with control diet. Fermented diet also increased the abundance of insulin, insulin receptor, myoblast determination protein (MyoD) and myosin heavy chain-I (MyHC-I) transcripts, and the phosphorylation levels of protein kinase B (AKT), mammalian target of rapamycin (mTORC1), initiation factor 4E-binding protein 1 (4EBP1) and S6 kinase 1 (S6K1) in LT, while decreasing the expression of muscle atrophy F-box (MAFbx) and forkhead Box O1 (Foxo1) mRNA transcripts. Our results indicated that fermented diet improved meat quality and enhanced LT growth of finishing pigs by increasing insulin/AKT/mTORC1 protein synthesis cascade and activating Foxo1/MAFbx pathway, along with the regulation of ribosomal protein and proteins involved in muscle contraction and muscle hypertrophy. This study investigated the effect of fermented diet on growth performance, carcass traits, meat quality and growth of longissimus thoracis (LT) of finishing pigs. A total of 48 finishing pigs [Duroc × (Landrace × Large White), male, 126 ± 5-d-old] weighing 98.76 ± 1.27 kg were randomly assigned to two treatments (eight pens per treatment and three pigs per pen) for a 28-d feeding trial, including control diet and fermented diet. Fermented diet significantly increased the loin eye area and lean mass percentage, decreased backfat thickness and improved meat quality of LT by decreasing the shear force and drip loss at 48 h post slaughter and improving meat sensory characteristics compared with control diet. A fermented diet also significantly increased the abundance of insulin, insulin receptor (IR), myoblast determination protein (MyoD) and myosin heavy chain-I (MyHC-I) transcripts, and the phosphorylation levels of AKT, mTORC1, 4EBP1 and S6K1 in LT, while decreasing the expression of muscle atrophy F-box (MAFbx) and forkhead Box O1 (Foxo1) mRNA transcripts. Moreover, proteomic analysis revealed that differentially expressed proteins predominantly involved in protein synthesis and muscle development were modulated by fermented diet. Our results indicated that a fermented diet improved meat quality and enhanced LT growth of finishing pigs by increasing insulin/AKT/mTORC1 protein synthesis cascade and activating the Foxo1/MAFbx pathway, along with the regulation of ribosomal protein and proteins involved in muscle contraction and muscle hypertrophy.

Altered m6 A modification is involved in up-regulated expression of FOXO3 in luteinized granulosa cells of non-obese polycystic ovary syndrome patients.

The pathophysiology of polycystic ovary syndrome (PCOS) is characterized by granulosa cell (GC) dysfunction. m6A modification affects GC function in patients with premature ovarian insufficiency (POI), but the role of m6A modification in PCOS is unknown. The purpose of the prospective comparative study was to analyse the m6A profile of the luteinized GCs from normovulatory women and non‐obese PCOS patients following controlled ovarian hyperstimulation. RNA m6A methylation levels were measured by m6A quantification assay in the luteinized GCs of the controls and PCOS patients. Then, m6A profiles were analysed by methylated RNA immunoprecipitation sequencing (MeRIP‐seq). We reported that the m6A level was increased in the luteinized GCs of PCOS patients. Comparative analysis revealed differences between the m6A profiles from the luteinized GC of the controls and PCOS patients. We identified FOXO3 mRNA with reduced m6A modification in the luteinized GCs of PCOS patients. Selectively knocking down m6A methyltransferases or demethylases altered expression of FOXO3 in the luteinized GCs from the controls, but did not in PCOS patients. These suggested an absence of m6A‐mediated transcription of FOXO3 in the luteinized GCs of PCOS patients. Furthermore, we demonstrated that the involvement of m6A in the stability of the FOXO3 mRNA that is regulated via a putative methylation site in the 3’‐UTR only in the luteinized GCs of the controls. In summary, our findings showed that altered m6A modification was involved in up‐regulated expression of FOXO3 mRNA in the luteinized GCs from non‐obese PCOS patients following controlled ovarian hyperstimulation.

MRNA expression of ageing-associated genes in calorie reduction is subject to donor variability and can be induced by calorie restriction mimetics.

Finding ways to a healthier ageing are increasingly becoming the focus of geriatric research. One way to accomplish this could be calorie restriction, as this is known to positively influence the ageing of model organisms. The aim of this study was to investigate the influence of calorie reduction (F. X. Mayr therapy) and of the calorie restriction mimetics resveratrol and spermidine on the expression of ageing-associated genes. mRNA expression in peripheral blood mononuclear cells (PBMCs) of 18 participants taking part in an F. X. Mayr therapy was analysed. The PBMCs of one additional participant were treated ex vivo with spermidine or resveratrol. mRNA expression of SIRT1, SIRT3, FOXO3 and SOD2 was determined for these two calorie restriction mimetics. For the F. X. Mayr therapy samples, mRNA of XPA was analysed additionally. mRNA expression of the ageing-associated genes showed a distinct donor variation during F. X. Mayr therapy, with a significant increase in mRNA expression of SIRT1. Expression of XPA was similar to SIRT1, with a significant correlation at the last time point tested. Spermidine treatment of PBMCs resulted in a significantly increased expression of all genes tested, whereas resveratrol treatment caused a significant increase of SIRT3, FOXO3 and SOD2 mRNA expression. By increasing SIRT1 and XPA mRNA expression, calorie reduction in the form of F. X. Mayr therapy could contribute to a healthier ageing; however, the donor variability observed showed that not everyone benefited from this. Calorie restriction mimetics may be an option for promote healthier ageing for those who do not benefit from calorie reduction.

Effect of different fractions of chia (Salvia hispanica L.) on glucose metabolism, in vivo and in vitro

• Chia oil recovered glycolysis enzymes, glucose tolerance and AKT phosphorylation. • Chia oil and flour decreased adiposity and increased AMPK gene expression. • Chia hydrolyzed phenolics did not improve AKT phosphorylation of protein in HepG2 cells. • Chia hydrolyzed phenolics decreased glycolytic and gluconeogenic enzymes in vitro. The influence of chia ( Salvia hispanica L.) flour and oil on glucose metabolism (GM) in insulin resistant (IR) Wistar rats and the effect of chia hydrolyzed phenolics extract (CHPE) on GM in IR HepG2 cells were evaluated. In vivo study: animals were divided into four groups: AIN-93M, high-fat and high-fructose (HFHF), HFHF with chia flour (14.7%) or chia oil (4%). In vitro study: IR HepG2 cells were treated with CHPE (80 ppm). In vivo , chia flour and oil reduced adiposity and increased AMPK mRNA. Chia oil improved glucose tolerance, increased AKT1[pS473] protein level, mRNA of insulin receptor, FOXO1 and glycolysis enzymes. In vitro , CHPE decreased gluconeogenesis enzymes mRNA. Chia flour and oil decreased adiposity, but only chia oil was able to improve glucose tolerance and restore energy fuel system in liver of rats fed HFHF diet. CHPE decreased mRNA levels of gluconeogenesis enzymes.

Anti-inflammatory activity of berberine in non-alcoholic fatty liver disease via the Angptl2 pathway

BackgroundNonalcoholic fatty liver disease (NAFLD) has become the most common liver disease worldwide. Recent studies have shown that the Angptl2 pathway mediated hepatic inflammatory response plays an important role in the progression of nonalcoholic fatty liver disease. Our study investigated the possible molecular mechanisms of berberine (BBR) in the treatment of the liver inflammatory response in the livers of rats with high-fat diet-induced NAFLD via the Angptl2 pathway.ResultsAt the end of 12 weeks, compared with the control group rats, the high-fat- diet group rats showed obvious pathological and biochemical changes. The levels of pro-infalmmatory cytokines (CCL2, TNF-α) were increased, the infiltration of inflammatory cells (CCR2) was elevated, and the hepatic mRNA and protein levels of Angptl2, NF-κB and Foxo1 were increased to different degrees. Nevertheless, following treatment with BBR, liver tissue pathology, biochemical data, and Angptl2 pathway-related genes expression were significantly ameliorated.ConclusionsOur findings demonstrate that BBR might attenuate the liver inflammatory response in the livers of rats with high-fat diet-induced NAFLD through the regulation of the Angptl2 pathway.

RNA m6A methylation regulates sorafenib resistance in liver cancer through FOXO3‐mediated autophagy

N6‐methyladenosine (m6A) is an abundant nucleotide modification in mRNA, known to regulate mRNA stability, splicing, and translation, but it is unclear whether it is also has a physiological role in the intratumoral microenvironment and cancer drug resistance. Here, we find that METTL3, a primary m6A methyltransferase, is significantly down‐regulated in human sorafenib‐resistant hepatocellular carcinoma (HCC). Depletion of METTL3 under hypoxia promotes sorafenib resistance and expression of angiogenesis genes in cultured HCC cells and activates autophagy‐associated pathways. Mechanistically, we have identified FOXO3 as a key downstream target of METTL3, with m6A modification of the FOXO3 mRNA 3′‐untranslated region increasing its stability through a YTHDF1‐dependent mechanism. Analysis of clinical samples furthermore showed that METTL3 and FOXO3 levels are tightly correlated in HCC patients. In mouse xenograft models, METTL3 depletion significantly enhances sorafenib resistance of HCC by abolishing the identified METTL3‐mediated FOXO3 mRNA stabilization, and overexpression of FOXO3 restores m6A‐dependent sorafenib sensitivity. Collectively, our work reveals a critical function for METTL3‐mediated m6A modification in the hypoxic tumor microenvironment and identifies FOXO3 as an important target of m6A modification in the resistance of HCC to sorafenib therapy.

Saturated Fatty Acid‐Enriched Diet Affect Liver Transcriptional Response of Anti‐oxidant Genes of Perinatal Undernourished Rats

In this work, we evaluated the impact of a saturated fatty acid (SFA)‐enriched diet (HL) in the post‐weaning offspring subjected to maternal protein restriction in liver genes of redox balance and inflammatory pathway. Wistar rats were mated and during gestation and lactation, mothers received control (C) or low protein diet (LP, 8% protein). After weaning, rats received either C or HL (+59% SFA) diets up to 90 days of life. It was verified that circulating markers of lipid metabolism and liver function were not significantly altered between groups. The LP group submitted to the post‐weaning HL diet showed an increase in liver protein and lipid oxidation (p&lt;0.01). This group also presented greater gene transcription of NF‐KB1 and TNF‐α (p&lt;0.05) compared to controls. Liver mRNA contents of pro‐oxidant enzymes (XDH, NOX1 and RAC1) were not different between LP and controls animals. Post‐weaning HL diet did not alter the pattern of expression of SOD1, SOD2, CAT, GPX1, GPX2, UCP2 genes in LP groups, except for CAT, which was significantly higher in LP group fed HL diet compared to C (+66%, p&lt;0.05). In protein level, CAT was lower in LP compared to control animals under both post‐weaning C and HL (p&lt;0.05). In contrast, SOD2 protein content was twice higher in LP groups (p&lt;0.05). However, GPX1/2 protein expression was similar between groups. Regarding transcription factors, no differences were noted in NRF2 and FOXO3 mRNA contents. However, SFA enhanced PGC1α (+207%, p&lt;0.05) and PPARγ (+151%, p&lt;0.05) levels in LP groups vs. C. Thus, our data suggest that SFA‐enriched diet induces oxidative stress, activation of inflammatory pathways, however without metabolic disturbance when the animals were submitted to a low protein diet during critical periods of development.Support or Funding InformationThis study was supported by FACEPE (Brazil), CNPq (Brazil) and CAPES/COFECUB (Brazil/France).

Polymerase independent repression of FoxO1 transcription by sequence-specific PARP1 binding to FoxO1 promoter

Poly(ADP-ribose) polymerase 1 (PARP1) regulates gene transcription in addition to functioning as a DNA repair factor. Forkhead box O1 (FoxO1) is a transcription factor involved in extensive biological processes. Here, we report that PARP1 binds to two separate motifs on the FoxO1 promoter and represses its transcription in a polymerase-independent manner. Using PARP1-knock out (KO) cells, wild-type-PARP1-complemented cells and catalytic mutant PARP1E988K-reconstituted cells, we investigated transcriptional regulation by PARP1. PARP1 loss led to reduced DNA damage response and ~362-fold resistance to five PARP inhibitors (PARPis) in Ewing sarcoma cells. RNA sequencing showed 492 differentially expressed genes in a PARP1-KO subline, in which the FoxO1 mRNA levels increased up to more than five times. The change in the FoxO1 expression was confirmed at both mRNA and protein levels in different PARP1-KO and complemented cells. Moreover, exogenous PARP1 overexpression reduced the endogenous FoxO1 protein in RD-ES cells. Competitive EMSA and ChIP assays revealed that PARP1 specifically bound to the FoxO1 promoter. DNase I footprinting, mutation analyses, and DNA pulldown FREP assays showed that PARP1 bound to two particular nucleotide sequences separately located at −813 to −826 bp and −1805 to −1828 bp regions on the FoxO1 promoter. Either the PARPi olaparib or the PARP1 catalytic mutation (E988K) did not impair the repression of PARP1 on the FoxO1 expression. Exogenous FoxO1 overexpression did not impair cellular PARPi sensitivity. These findings demonstrate a new PARP1-gene promoter binding mode and a new transcriptional FoxO1 gene repressor.

Angelica Sinensis Polysaccharide Suppresses Epithelial-Mesenchymal Transition and Pulmonary Fibrosis via a DANCR/AUF-1/FOXO3 Regulatory Axis.

Idiopathic pulmonary fibrosis (IPF) is characterized by the accumulation of lung fibroblasts and extracellular matrix deposition. Angelica sinensis polysaccharide (ASP), the major bioactive component that can extracted from roots of angelica, plays functional roles in immunomodulation, anti-tumor activity, and hematopoiesis. Emerging evidence has suggested that long noncoding RNAs (lncRNAs) play important roles in pathophysiological processes in various diseases. However, the roles of lncRNAs and ASP in IPF remain poorly understood. In the present study, we investigated the effects of ASP in IPF, as well as their functional interactions with lncRNA DANCR (differentiation antagonizing non-protein coding RNA). IPF models were established by treating Sprague-Dawley rats with BLM and treating alveolar type Ⅱ epithelial (RLE-6TN) cells with TGF-β1. Our results showed that ASP treatment suppressed pulmonary fibrosis in rats and fibrogenesis in RLE-6TN cells. The lncRNA DANCR is downregulated after ASP treatment in both rat lung tissues and RLE-6TN cells, and DANCR overexpression dramatically reversed the suppressive effects of ASP in IPF. Mechanistically, DANCR directly binds with AUF1 (AU-binding factor 1), thereby upregulating FOXO3 mRNA and protein levels. Moreover, overexpression of AUF1 or FOXO3 reversed the functional effects induced by ASP treatment. In conclusion, our findings showed that DANCR mediates ASP-induced suppression of IPF via upregulation of FOXO3 protein levels in an AUF1-dependent manner. Therefore, DANCR could serve as a promising therapeutic target in IPF treatment with ASP.

Xuefu Zhuyu Oral Liquid () Prevents Apoptosis of Ischemic Myocardium Cells in Rats by Regulating SIRT1 and Its Pathway-Related Genes.

To observe the changes of ischemic myocardial cells apoptosis in rats following intervention with Xuefu Zhuyu Oral Liquid (, XFZY), as well as changes of protein expression of silent information regulator 1 (SIRT1) and SIRT1 pathway-related genes. H9c2 rat myocardial cells were divided into 6 groups: control group, oxygen glucose deprivation (OGD) group, SIRT1 siRNA group, OGD+SIRT1 siRNA group, OGD+XFZY group, and OGD+SIRT1 siRNA+XFZY group. Quantitative fluorescent polymerase chain reaction (PCR) and Western blot were used to detect the concentration variations of SIRT1 and its pathway-related genes and corresponding protein expression after XFZY intervention and SIRT1 transfection. Compared with the control group, the mRNA and protein expressions of SIRT1 were decreased obviously, while the mRNA and protein levels of P53, FoxO1, FoxO3, FoxO4 and nuclear factor kappa B (NF-ΚB) were increased in the OGD group, SIRT1 siRNA group, and OGD+SIRT1 siRNA group (P<0.01). Compared with the OGD group and OGD+SIRT1 siRNA group, the treatment of XFZY inhibited the decline in SIRT1 mRNA and protein expressions (P<0.01), and down-regulated the mRNA and protein levels of P53, FoxO1, FoxO3, FoxO4 and NF-ΚB, respectively (P<0.05 or P<0.01). XFZY could prevent myocardial cells apoptosis probably by increasing the mRNA and protein expressions of SIRT1 and inhibiting the mRNA and protein expressions of P53, NF- K B, FoxO1, FoxO3 and FoxO4.

Dysregulation of FOXO transcription factors in Epstein-Barr virus-associated gastric carcinoma

Epstein-Barr virus (EBV) infection is associated with the development of gastric cancer (GC). Forkhead box class O (FOXO) transcription factors play important roles in tumor suppression. This study aims to investigate the interplay between EBV and FOXOs in EBV-associated GC (EBVaGC). The results showed that EBV infection of GC cells led to the downregulation of FOXO1 by the inhibition of its mRNA and protein expression. FOXO3 protein is repressed by EBV infection. FOXO4 mRNA is upregulated in EBV-positive cell lines, while its protein expression is downregulated. FOXO1, FOXO3 and FOXO4 proteins are upregulated following PI3K inhibition in GT39 cells, confirming that they are partially suppressed by the PI3K/AKT pathway. However, the upregulation of FOXO1 and FOXO3 by single transfection with LMP1 or LMP2A implies that the dysregulation of FOXOs in EBVaGC is affected by various EBV latent genes and that PI3K/AKT signaling is not the only mechanism of FOXO regulation.

Pre-hypoxia exposure inhibited copper toxicity by improving energy metabolism, antioxidant defence and mitophagy in the liver of the large yellow croaker Larimichthys crocea

This study investigated the effects of moderate hypoxia pre-exposure on energy metabolism, antioxidant defence and mitophagy in the liver of the large yellow croaker Larimichthys crocea exposed to Cu. Fish were pre-exposed to either normoxia or hypoxia (~3.0 mg L−1, 42% O2 saturation) for 48 h, and subsequently were subjected to either control (without Cu addition) or Cu (168 μg L−1) under normoxic conditions for another 48 h. Copper exposure under normoxia induced Cu toxicity that increased mortality, the production of reactive oxygen species (ROS) and malondialdehyde, and aberrant hepatic mitochondrial ultrastructure. Interestingly, hypoxia pre-exposure improved energy metabolism, antioxidant ability and mitophagy response, and reduced the Cu content to inhibit Cu toxicity, reflecting the enhanced survival rate and reduced oxidative damage. In these processes, hypoxia-inducible factor-1α (HIF-1α), transcription factors NFE2-related nuclear factor 2 (Nrf2), and forkhead box O-3 (FoxO3) mRNA levels were correlated with expression of genes related to energy metabolism, antioxidant defence and mitophagy, respectively, indicating HIF-1α, Nrf2, and FoxO3 are required for the induction of their respective target genes. Overall, moderate hypoxia pre-exposure was able to generate adaptive responses to mitigate Cu-induced toxicological effects, underlining a central role of hormesis.

MiRNA-96-5p contributed to the proliferation of gastric cancer cells by targeting FOXO3.

Various microRNAs (miRNAs, miRs) and the forkhead box O (FOXO) family proteins have been shown to influence gastric cancer progression and development. Here, we aimed to identify the gastric cancer related miRNAs and their relationship with the FOXO family. MiRNA profiles were generated by miRNA microarray screening from pre-operative plasma samples. Quantitative reverse transcription PCR and western bolt were used to determine the expression levels of miR-96 and FOXO family. 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide assay and colony formation assay were used to test the cell viability. The miR-96-5p and FOXO3 interaction were confirmed by luciferase reporter assay. Our results demonstrated the excessive expression of miR-96-5p in gastric cancer cell lines and plasma samples from gastric cancer patients. In addition, the protein levels of FOXO3 were decreased in tissue samples from gastric cancer patients. Moreover, miR-96-5p accelerated the gastric cancer cell proliferation by directly targeting FOXO3. Therefore, we conclude that iR-96-5p might promote the progression of gastric cancer by directly targeting FOXO3 mRNA and downregulating the expression of FOXO3 protein, which provides new insights for the molecular mechanism of gastric cancer.