FoxO1 Protein Levels Research Articles

Bevacizumab Increases Endothelin-1 Production via Forkhead Box Protein O1 in Human Glomerular Microvascular Endothelial Cells In Vitro.

Molecular mechanisms underlying the nephrotoxicity associated with bevacizumab are unclear. Endothelin-1 (ET-1) is involved in podocyte injury and proteinuria, and its level increases in most cases of kidney disorders. Forkhead box protein O1 (FoxO1), a transcription factor, is a major determinant of ET-1 promoter activation and is regulated by protein kinase B (Akt) phosphorylation-dependent nuclear exclusion. We evaluated the effect of bevacizumab on ET-1 production in human glomerular microvascular endothelial cells (hGECs). We analyzed the changes in the mRNA and protein levels of ET-1 in hGECs treated with bevacizumab using real-time reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. Changes in the protein levels and phosphorylation status of Akt and FoxO1 in hGECs treated with bevacizumab were analyzed by western blotting. After cell lysis, FoxO1 protein was isolated from the cytoplasmic and nuclear fractions. We also investigated the effects of AS1842856 (a FoxO1 inhibitor) on bevacizumab-induced ET-1 production. Bevacizumab significantly and dose-dependently increased the mRNA and protein levels of ET-1 in hGECs (p < 0.05). Bevacizumab treatment also led to a decrease in phosphorylated Akt protein levels. Inhibition of Akt activity by LY294002 promoted ET-1 production. Bevacizumab also induced an increase in FoxO1 protein levels in the nucleus. Inhibition of FoxO1 activity by AS1842856 resulted in decreased ET-1 levels in bevacizumab-treated hGECs. ET-1 axis activation, Akt inactivation, and FoxO1 nuclear localization are the molecular mechanisms underlying bevacizumab-induced nephrotoxicity. Therefore, inhibition of renal ET-1 production could be a promising approach to protect against or treat bevacizumab-induced nephrotoxicity.

NaF reduces KLK4 expression by decreasing Foxo1/Runx2 expression in LS8 cells

ObjectiveThis study aimed to investigate the effect of high fluoride on runt-related transcription factor 2 (Runx2) expression and to explore the possible relationship among Runx2, forkhead box o1 (Foxo1) and kallikrein 4 (KLK4) in high fluoride-treated ameloblasts. DesignAmeloblast-like cells (LS8 cells) were exposed to various concentrations of sodium fluoride (NaF) for up to 48 h. Runx2 expression was downregulated by gene silencing, and Foxo1 expression was up- and downregulated by gene overexpression and silencing, respectively. The mRNA and protein levels of Runx2, Foxo1, KLK4 and matrix metalloproteinase 20 (MMP20) were detected by qRT-PCR and western blotting. ResultsRunx2 expression was decreased in a dose- and time-dependent manner in NaF-treated LS8 cells. The knockdown of Runx2 markedly decreased KLK4 expression in LS8 cells under NaF conditions. However, the variation trend of MMP20 was unclear. In addition, forced Foxo1 expression led to significant upregulation of Runx2 in LS8 cells under NaF conditions. In contrast, the knockdown of Foxo1 markedly decreased the Runx2 protein levels under NaF conditions. Moreover, Foxo1 downregulation markedly decreased runx2 mRNA levels, and this inhibition in LS8 cells was intensified when combined with NaF treatment. ConclusionThe results indicated that NaF reduces Runx2 expression in LS8 cells and that decreased Foxo1/Runx2 expression induced by high fluoride is a cause of low KLK4 expression.

SMC4 knockdown inhibits malignant biological behaviors of endometrial cancer cells by regulation of FoxO1 activity

Structural maintenance of chromosomes 4 (SMC4) has an important role in chromosome condensation and segregation, which is involved in regulating multiple tumor development. However, the role of SMC4 in endometrial cancer is uncertain. The expression and prognostic value of SMC4 were predicted by UALCAN, Gene Expression Omnibus (GEO), The Human Protein Atlas and Kaplan Meier plotter tools. SMC4-related genes were analyzed by LinkedOmics, Gene Ontology (GO) annotations, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Forkhead box protein O1 (FoxO1) activity was suppressed by AS1842856 (AS). SMC4, Ki67, B-cell lymphoma-2(Bcl-2), Bcl-2 associated X protein (Bax), FoxO1, phosphorylated FoxO1 (p-FoxO1), and p27 protein levels were detected by Western blotting. Cell proliferation was detected using Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2′-deoxyuridine (EdU) analyses. Cell apoptosis was measured using TUNEL analysis. SMC4 abundance was increased in endometrial cancer, and predicted a worse overall survival. SMC4 knockdown repressed proliferative ability of endometrial cancer cells and promoted cell apoptosis. SMC4 knockdown promoted FoxO1 transactivation by decreasing its phosphorylated level. Addition of AS inhibited FoxO1 activity by increasing the phosphorylated level of FoxO1. The inhibition of FoxO1 activity reversed the effect of SMC4 silencing on cell proliferation and apoptosis. In conclusion, SMC4 silencing restrained cell proliferation and facilitated apoptosis in endometrial cancer via regulating FoxO1 activity.

FoxO3 deficiency in cortical astrocytes leads to impaired lipid metabolism and aggravated amyloid pathology.

The rise of life expectancy of the human population is accompanied by the drastic increases of age‐associated diseases, in particular Alzheimer's disease (AD), and underscores the need to understand how aging influences AD development. The Forkhead box O transcription factor 3 (FoxO3) is known to mediate aging and longevity downstream of insulin/insulin‐like growth factor signaling across species. However, its function in the adult brain under physiological and pathological conditions is less understood. Here, we report a region and cell‐type‐specific regulation of FoxO3 in the central nervous system (CNS). We found that FoxO3 protein levels were reduced in the cortex, but not hippocampus, of aged mice. FoxO3 was responsive to insulin/AKT signaling in astrocytes, but not neurons. Using CNS Foxo3‐deficient mice, we reveal that loss of FoxO3 led to cortical astrogliosis and altered lipid metabolism. This is associated with impaired metabolic homoeostasis and β‐amyloid (Aβ) uptake in primary astrocyte cultures. These phenotypes can be reversed by expressing a constitutively active FOXO3 but not a FOXO3 mutant lacking the transactivation domain. Loss of FoxO3 in 5xFAD mice led to exacerbated Aβ pathology and synapse loss and altered local response of astrocytes and microglia in the vicinity of Aβ plaques. Astrocyte‐specific overexpression of FOXO3 displayed opposite effects, suggesting that FoxO3 functions cell autonomously to mediate astrocyte activity and also interacts with microglia to address Aβ pathology. Our studies support a protective role of astroglial FoxO3 against brain aging and AD.

CircSTK40 contributes to recurrent implantation failure via modulating the HSP90/AKT/FOXO1 axis

Increasing evidence has revealed a close relationship between non-coding RNAs and recurrent implantation failure (RIF). However, the role of circular RNAs (circRNAs) in RIF pathogenesis remains largely unknown. Microarray analyses were used to identify the differentially expressed circRNA-circSTK40. Functional experiments, including decidualization induction and terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay, were performed to determine the effects of circSTK40 on human endometrial stromal cells (ESCs). The interactions between circSTK40 and proteins were investigated by RNA pull-down, RNA immunoprecipitation, and co-immunoprecipitation (coIP) assays. We observed that circSTK40 expression was upregulated in the RIF midluteal-phase endometrial samples. circSTK40 overexpression in ESCs inhibited the decidualization process but concurrently enhanced cell survival during stress. Mechanistically, circSTK40 directly bound to HSP90 and CLU, thus functioning as a scaffold to block their interactions and hinder the proteasomal degradation of HSP90. The resulting high levels of HSP90 led to the activation of the AKT pathway and downregulation of FOXO1 expression. Inhibitors of AKT (MK-2206) and HSP90 (17AAG) both abolished the effects of circSTK40 overexpression in ESCs and increased the decidualization levels in a dose-dependent manner. Our findings indicate a novel epigenetic mechanism for RIF pathogenesis involving circSTK40 activity and provide a foundation for targeted treatments in patients with low endometrial receptivity.

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.

Hyperglycemia in Mice with Early Diabetes Predisposes for Cardiac Dysfunction

Introduction Cardiac glucose uptake and oxidation are reduced in diabetes despite hyperglycemia, and aberrant fatty acid (FA) utilization by hearts accounts, at least partially, for diabetic cardiomyopathy (DbCM). Recently, we found that FOXO1, which is activated during insulin resistance, increases KLF5 expression that causes DbCM through lipotoxicity and oxidative stress. Herein, we investigated the metabolic profile of cardiomyocytes (CMs) in early and late type-1 diabetes (T1D) and the potential involvement of FOXO1 activation in cardiac complications. Hypothesis In the early stage of diabetes, high glucose accounts for the onset of DbCM. Methods and Results We induced T1D in mice via 5 daily intraperitoneal injections of streptozotocin (STZ). Cardiac protein analysis 4 weeks post-STZ injection (early T1D), showed lower pser256 FOXO1 and increased FOXO1 protein levels in nuclear extracts compared to non-T1D mice, indicating increased nuclear FOXO1 translocation. Despite increased nuclear presence, FOXO1 was transcriptionally inactive as shown by normal FOXO1 acetylation levels and expression of FOXO1 target genes. On the other hand, the same analyses 12 weeks post-STZ injection (late T1D) showed that nuclear FOXO1 translocation coincided with higher transcriptional activity. CoIP analysis suggests that SIRT1 deacetylates FOXO1 in late T1D since high glucose upregulated SIRT1 in a human CM cell line (AC16). In contrast to FOXO1 transcriptional status, echocardiography revealed that CM-specific FOXO1 deleted mice were protected from mild cardiac dysfunction that occurs in early T1D, indicating FOXO1 as a minor contributing factor in early-T1D cardiac complications. Seahorse analysis in adult CMs isolated from early T1D-mice showed higher glucose and lower FA dependence compared to non-T1D mice. In accordance with previous studies, the metabolic profile of adult CMs from mice with late T1D shifted to higher FA and lower glucose dependence compared to non-T1D mice. Then, we explored whether increased glucose dependence in early T1D may account for the initiation of DbCM. To this end, we treated T1D mice with an inhibitor of the sodium/glucose cotransporter (SGLT)2 (dapagliflozin). Dapagliflozin normalized plasma glucose levels, improved insulin sensitivity (GTT and ITT), reduced lipolysis in white adipose tissue and prevented DbCM without affecting hepatic VLDL-triglyceride secretion. Adult CMs of mice treated with STZ and dapagliflozin for 4 weeks showed higher FA and lower glucose dependence compared to mice with early T1D. Accordingly, cardiac lipidome analysis showed that dapagliflozin restored acylcarnitines, which is an essential component of FA oxidation, to normal levels as opposed to T1D-mice that had lower acylcarnitines compared to non-T1D mice. Conclusion Hyperglycemia in early T1D facilitates higher glucose dependence of CMs, which leads to DbCM independent of FOXO1 activation.

Lycopene promotes a fast-to-slow fiber type transformation through Akt/FoxO1 signaling pathway and miR-22-3p

Abstract This study investigated molecular mechanisms of lycopene regulating muscle fiber type transformation in vitro and in vivo. Remarkably, TNNI1 protein level was increased, while TNNI2 protein level was decreased in C2C12 myotubes and in mice after lycopene treatment. Lycopene also enhanced enzyme activities of succinic dehydrogenase and malate dehydrogenase and reduced lactate dehydrogenase activity. Meanwhile, lycopene markedly upregulated the protein expressions of P-Akt and P-FoxO1 and decreased FoxO1 protein level. However, specific blocking Akt/FoxO1 signaling by wortmannin effectively eliminated lycopene-induced upregulation of slow MyHC and downregulation of fast MyHC in C2C12 myotubes. In addition, lycopene effectively inhibited miR-22-3p expression in C2C12 myotubes and in mice, whereas miR-22-3p mimics attenuated transformation from fast glycolytic fiber to slow oxidative fiber caused by lycopene. Our findings provided the first evidence that lycopene promoted muscle fiber type transformation from fast-twitch to slow-twitch through Akt/FoxO1 pathway and miR-22-3p.

The Role of the FOXO1/β2-AR/p-NF-κB p65 Pathway in the Development of Endometrial Stromal Cells in Pregnant Mice under Restraint Stress.

Restraint stress causes various maternal diseases during pregnancy. β2-Adrenergic receptor (β2-AR) and Forkhead transcription factor class O 1 (FOXO1) are critical factors not only in stress, but also in reproduction. However, the role of FOXO1 in restraint stress, causing changes in the β2-AR pathway in pregnant mice, has been unclear. The aim of this research was to investigate the β2-AR pathway of restraint stress and its impact on the oxidative stress of the maternal uterus. In the study, maternal mice were treated with restraint stress by being restrained in a transparent and ventilated device before sacrifice on Pregnancy Day 5 (P5), Pregnancy Day 10 (P10), Pregnancy Day 15 (P15), and Pregnancy Day 20 (P20) as well as on Non-Pregnancy Day 5 (NP5). Restraint stress augmented blood corticosterone (CORT), norepinephrine (NE), and blood glucose levels, while oestradiol (E2) levels decreased. Moreover, restraint stress increased the mRNA levels of the FOXO family, β2-AR, and even the protein levels of FOXO1 and β2-AR in the uterus and ovaries. Furthermore, restraint stress increased uterine oxidative stress level. In vitro, the protein levels of FOXO1 were also obviously increased when β2-AR was activated in endometrial stromal cells (ESCs). In addition, phosphorylated-nuclear factor kappa-B p65 (p-NF-κB p65) and its target genes decreased significantly when FOXO1 was inhibited. Overall, it can be said that the β2-AR/FOXO1/p-NF-κB p65 pathway was activated when pregnant mice were under restraint stress. This study provides a scientific basis for the origin of psychological stress in pregnant women.

Effects of fenofibrate and its combination with lovastatin on the expression of genes involved in skeletal muscle atrophy, including FoxO1 and its targets.

Fibrates and statins have been widely used to reduce triglyceride and cholesterol levels, respectively. Besides its lipid-lowering effect, the side effect of muscle atrophy after fibrate administration to humans has been demonstrated in some studies. Combination therapy with fibrates and statins also increases the risk of rhabdomyolysis. FoxO1, a member of the FoxO forkhead type transcription factor family, is markedly upregulated in skeletal muscle in energy-deprived states and induces muscle atrophy via the expression of E3-ubiquitine ligases. In this study, we investigated the changes in FoxO1 and its targets in murine skeletal muscle with fenofibrate treatment. High doses of fenofibrate (greater than 0.5% (wt/wt)) over one week increased the expression of FoxO1 and its targets in the skeletal muscles of mice and decreased skeletal muscle weight. These fenofibrate-induced changes were diminished in the PPARα knockout mice. When the effect of combination treatment with fenofibrate and lovastatin was investigated, a significant increase in FoxO1 protein levels was observed despite the lack of deterioration of muscle atrophy. Collectively, our findings suggest that a high dose of fenofibrate over one week causes skeletal muscle atrophy via enhancement of FoxO1, and combination treatment with fenofibrate and lovastatin may further increase FoxO1 protein level.

Growth hormone activates PI3K/Akt signaling and inhibits ROS accumulation and apoptosis in granulosa cells of patients with polycystic ovary syndrome

BackgroundIt is reported that growth hormone (GH) can alleviate oxidative stress (OS) induced apoptosis in some types of cells by activating the PI3K/Akt signaling pathway. This study investigated the role and underlying mechanism of GH in OS and apoptosis in granulosa cells (GCs) of patients with polycystic ovary syndrome (PCOS).MethodsPrimary GCs were collected from patients with and without PCOS (controls, n = 32) during oocyte retrieval. The patients with PCOS were randomly assigned to take GH treatment (PCOS-GH, n = 30) or without GH treatment (PCOS-C, n = 31). Reactive oxygen species (ROS) level was determined by spectrophotometry and fluorescence microscopy. GC apoptosis and mitochondrial membrane potential (MMP) were detected by Annexin V-FITC/PI double-staining and JC-1 staining, respectively (flow cytometry). The expression of apoptosis-related genes and proteins involved in PI3K/Akt signaling was determined by quantitative reverse-transcription polymerase chain reaction and western blotting, while active caspase-9 and caspase-3 levels of GCs were determined by enzyme-linked immunosorbent assay.ResultsOur study found that in GCs of the PCOS-GH group, the ROS levels and apoptotic rates were significantly decreased, whereas MMP was significantly increased when compared to those in the PCOS-C group (P < 0.05). The mRNA levels of FOXO1, Bax, caspase-9, and caspase-3 were significantly decreased, whereas Bcl-2 was increased in GCs of the PCOS-GH group than those in the PCOS-C group (P < 0.05). The protein levels of FOXO1, Bax, cleaved caspase-9/caspase-9 and cleaved caspase-3/caspase-3 were decreased, whereas p-PI3K/PI3K, p-Akt/Akt, p-FOXO1 and Bcl-2 were increased in GCs of the PCOS-GH group, compared with those in the PCOS-C group (P < 0.05).ConclusionOS induced apoptosis and downregulated the PI3K/Akt signaling pathway in patients with PCOS. GH could alleviate apoptosis and activate the PI3K/Akt signaling pathway.Clinical trial registration numberChinese Clinical Trial Registry. ChiCTR1800019437. Prospectively registered on October 20, 2018.

TRIM47 Promotes the Development of Glioma by Ubiquitination and Degradation of FOXO1.

ObjectiveTo investigate the effect of TRIM47 on glioma cells and further explore its underlying molecular mechanisms.MethodsMouse xenograft model was used in this study. The mRNA expression of TRIM47 was detected by qRT-PCR. The cell viability and proliferation activity was detected by MTT assay and colony formation assay. The migration and invasion of glioma cells were determined by Transwell assay. The protein levels of TRIM47, FOXO1, CyclinD1, C-myc, MMP-2 and TIMP-1 were assessed by Western-blotting. The interaction between TRIM47 and FOXO1 was measured by Co-immunoprecipitation (Co-IP) assay.ResultsIn glioma tissues and cells, TRIM47 was significantly up-regulated. Silencing the expression of TRIM47 inhibited the cell viability and proliferation of cells A172 and U251, as well as their ability to invade and migrate. Among them, the expression levels of C-myc and CyclinD1 also decreased, and MMP-2 was down-regulated and TIMP-1 was up-regulated. Similarly, in vivo model, tumor volume and weight also decreased after TRIM47 knockout. Further research showed that TRIM47 inhibited FOXO1 expression by ubiquitination and degradation of FOXO1, thereby promoting glioma growth and progression.ConclusionIn our study, we confirmed functional role of the TRIM47-FOXO1 axis in the progression of gliomas and provided a potential target for glioma treatment.

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.

FoxO1 overexpression reduces Aβ production and tau phosphorylation in vitro

Forkhead box O1 (FoxO1), a key molecule in the regulation of cell growth, differentiation and metabolism, is an important transcription factor. However, the effect of FoxO1 on Alzheimer’s disease (AD) needs further investigation. In this study, we aimed to explore the function and mechanism of FoxO1 in amyloid-β (Aβ) production and tau phosphorylation in AD. First, compared with the age matched wild-type (WT) mice, we showed that FoxO1 protein levels were reduced in the cortices but nearly unchanged in the hippocampi of 6-month-old APPswe/PSEN1dE9 transgenic mice expressing Swedish APP and Presenilin1 delta exon 9 mutations (APP/PS1 mice). Then, we found that overexpression of FoxO1 significantly attenuated Aβ production through inhibiting the amyloidogenic processing of β-amyloid precursor protein (APP), mediated by the key enzymes BACE1 and PS1, in N2a/APPsw cells. Furthermore, in FoxO1-overexpressing HEK293/Tau cells, the decreased levels of tau phosphorylation at selective sites (S262 and T231) were accompanied by increasing the expression of p-GSK-3β (S9), and reducing p-ERK. In contrast, the total tau (Tau-5), non-phosphorylated tau (Tau-1), p-Tau (S404), CDK5 and PP2A levels remained unchanged. These findings indicate that FoxO1 is related to AD and suggest FoxO1 as a therapeutic target for AD that reduces the levels of both Aβ expression and tau phosphorylation.

Vitamin D Represses the Aggressive Potential of Osteosarcoma.

Osteosarcoma (OS) is the basic bone neoplasm with lower survival and poor prognosis. It is distinguished by its offensive nature and metastatic potential. The fundamental death source in OS patients is lung metastasis. In addition, the proliferation and cell migration are thus essential for cancer progression, especially for intrusion and transformation. Several studies have illustrated that 1,25-Dihydroxyvitamin D (1,25(OH)2D) has a critical role in the growth and differentiation of bone. However, knowledge of the outcome of 1,25(OH)2D on the progression and incursion of osteosarcoma cells is minimal. The present study aimed to analyze the effect of different concentrations of 1,25(OH)2D on the multiplication, progression, and intrusion of OS cells and verify the effective doses of 1,25(OH)2D that can decrease the intensity of the disease and improving the prognosis in OS patients. Saos-2 cells were treated with 1,25(OH)2D (0, 50, 100, and 200 nM) for 48, 72, and 96 hours. Proliferation, invasion, and migration were determined by MTT assay, Transwell assay, and Scratch test, respectively. The levels of c-Myc and FOXO1 proteins were determined by Western blotting. The proliferation, invasiveness, and migration of Saos-2 cells that were treated with 1,25(OH)2D were significantly decreased compared with untreated cells. Although 1,25(OH)2D notably decreased c-Myc protein levels (after 48 and 72 hours), FOXO1 protein levels have been significantly increased after 48 and 72 hours. 1,25(OH)2D and the vitamin D receptor (VDR) suppress c-Myc function through regulating the c-Myc/MXD1 network and thus, providing a molecular basis of 1,25(OH)2D related to the cancer-preventive actions. Based on the present results, 1,25(OH)2D by targeting c-Myc and FOXO1 expression displays anti-invasive, anti-migration and anti-proliferative effects on OS cells in vitro. Our findings suggest that effective doses of the 1,25(OH)2D may reduce the aggressive potential of the OS cell line. However, further investigation and clinical trials are needed.

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.

Ginsenoside Rg1 protects against d-galactose induced fatty liver disease in a mouse model via FOXO1 transcriptional factor

AimsRg1 is the most active component of traditional Chinese medicine ginseng, having anti-aging and anti-oxidative stress features in multiple organs. Cellular senescence of hepatocytes is involved in the progression of a wide spectrum of chronic liver diseases. In this study, we investigated the potential benefits and mechanism of action of Rg1 on aging-driven chronic liver diseases. Materials and methodsA total of 40 male C57BL/6 mice were randomly divided into four groups: control group; Rg1 group; Rg1+d-gal group; and d-gal group. Blood and liver tissue samples were collected for determination of liver function, biochemical and molecular markers, as well as histopathological investigation. Key findingsRg1 played an anti-aging role in reversing d-galactose induced increase in senescence-associated SA-β-gal staining and p53, p21 protein in hepatocytes of mice and sustained mitochondria homeostasis. Meanwhile, Rg1 protected livers from d-galactose caused abnormal elevation of ALT and AST in serum, hepatic steatosis, reduction in hepatic glucose production, hydrogenic degeneration, inflammatory phenomena including senescence-associated secretory phenotype (SASP) IL-1β, IL-6, MCP-1 elevation and lymphocyte infiltration. Furthermore, Rg1 suppressed drastic elevation in FOXO1 phosphorylation resulting in maintaining FOXO1 protein level in the liver after d-galactose treatment, followed by FOXO1 targeted antioxidase SOD and CAT significant up-regulation concurrent with marked decrease in lipid peroxidation marker MDA. SignificanceRg1 exerts pharmaceutic effects of maintaining FOXO1 activity in liver, which enhances anti-oxidation potential of Rg1 to ameliorate SASP and to inhibit inflammation, also promotes metabolic homeostasis, and thus protects livers from senescence induced fatty liver disease. The study provides a potential therapeutic strategy for alleviating chronic liver pathology.

Huagan tongluo Fang improves liver fibrosis via down-regulating miR-184 and up-regulating FOXO1 to inhibit Th17 cell differentiation

BackgroundThe purpose of this research is to reveal the improvement effect and potential mechanism of Huagan tongluo Fang (HGTLF) on liver fibrosis. MethodsA mouse model of liver fibrosis induced by CCl4 was established to analyze the effect of HGTLF on liver fibrosis. The expression changes of miRNA after HGTLF stimulation were detected by qRT-PCR. After interference with miR-184 in Th17 cells, the concentration of IL-17A in cell culture supernatants was detected by ELISA and the proportion of Th17 cells was analyzed by flow cytometry. The relationship between miR-184 and FOXO1 was verified by online software and dual-luciferase reporter system. After HGTLF treatment of Th17 cells overexpressing miR-184, the protein level of FOXO1 was detected by Western blot. ResultsHGTLF could significantly improve liver fibrosis in mice. By qRT-PCR, miR-184 was most significantly expressed after HGTLF drug stimulation, and miR-184 was considered to be the major RNA involved in Th17 cell differentiation. Interference with miR-184 in Th17 cells inhibited the differentiation of Th17 cells. By online software and dual-luciferase reporter system assay, the direct interaction of miR-184 with FOXO1 was confirmed. After HGTLF treatment of Th17 cells overexpressing miR-184, FOXO1 protein levels were significantly up-regulated and inhibited the differentiation of Th17 cells, which was reversed by miR-184 inhibitors. The Vivo experiments also confirmed the improvement effect of HGTLF on liver fibrosis in mice. ConclusionOur results indicated that HGTLF could improve liver fibrosis via down-regulating miR-184 and up-regulating of FOXO1 to inhibit Th17 cell differentiation.

Protective Properties of FOXO1 Inhibition in a Murine Model of Non-alcoholic Fatty Liver Disease Are Associated With Attenuation of ER Stress and Necroptosis.

AimThe pathogenesis of non-alcoholic fatty liver disease is currently unclear, however, lipid accumulation leading to endoplasmic reticulum stress appears to be pivotal in the process. At present, FOXO1 is known to be involved in NAFLD progression. The relationship between necroptosis and non-alcoholic steatohepatitis has been of great research interest more recently. However, whether FOXO1 regulates ER stress and necroptosis in mice fed with a high fat diet is not clear. Therefore, in this study we analyzed the relationship between non-alcoholic steatohepatitis, ER stress, and necroptosis.Main MethodsMale C57BL/6J mice were fed with an HFD for 14 weeks to induce non-alcoholic steatohepatitis. ER stress and activation of necroptosis in AML12 cells were evaluated after inhibition of FOXO1 in AML12 cells. In addition, mice were fed with AS1842856 for 14 weeks. Liver function and lipid accumulation were measured, and further, ER stress and necroptosis were evaluated by Western Blot and Transmission Electron Microscopy.Key FindingsMice fed with a high fat diet showed high levels of FOXO1, accompanying activation of endoplasmic reticulum stress and necroptosis. Further, sustained PA stimulation caused ER stress and necroptosis in AML12 cells. At the same time, protein levels of FOXO1 increased significantly. Inhibition of FOXO1 with AS1842856 alleviated ER stress and necroptosis. Additionally, treatment of mice with a FOXO1 inhibitor ameliorated liver function after they were fed with a high fat diet, displaying better liver condition and lighter necroptosis.SignificanceInhibition of FOXO1 attenuates ER stress and necroptosis in a mouse model of non-alcoholic steatohepatitis.

Loss of melusin is a novel, neuronal NO synthase/FoxO3-independent master switch of unloading-induced muscle atrophy.

BackgroundUnloading/disuse induces skeletal muscle atrophy in bedridden patients and aged people, who cannot prevent it by means of exercise. Because interventions against known atrophy initiators, such as oxidative stress and neuronal NO synthase (nNOS) redistribution, are only partially effective, we investigated the involvement of melusin, a muscle‐specific integrin‐associated protein and a recognized regulator of protein kinases and mechanotransduction in cardiomyocytes.MethodsMuscle atrophy was induced in the rat soleus by tail suspension and in the human vastus lateralis by bed rest. Melusin expression was investigated at the protein and transcript level and after treatment of tail‐suspended rats with atrophy initiator inhibitors. Myofiber size, sarcolemmal nNOS activity, FoxO3 myonuclear localization, and myofiber carbonylation of the unloaded rat soleus were studied after in vivo melusin replacement by cDNA electroporation, and muscle force, myofiber size, and atrogene expression after adeno‐associated virus infection. In vivo interference of exogenous melusin with dominant‐negative kinases and other atrophy attenuators (Grp94 cDNA; 7‐nitroindazole) on size of unloaded rat myofibers was also explored.ResultsUnloading/disuse reduced muscle melusin protein levels to about 50%, already after 6 h in the tail‐suspended rat (P < 0.001), and to about 35% after 8 day bed rest in humans (P < 0.05). In the unloaded rat, melusin loss occurred despite of the maintenance of β1D integrin levels and was not abolished by treatments inhibiting mitochondrial oxidative stress, or nNOS activity and redistribution. Expression of exogenous melusin by cDNA transfection attenuated atrophy of 7 day unloaded rat myofibers (−31%), compared with controls (−48%, P = 0.001), without hampering the decrease in sarcolemmal nNOS activity and the increase in myonuclear FoxO3 and carbonylated myofibers. Infection with melusin‐expressing adeno‐associated virus ameliorated contractile properties of 7 day unloaded muscles (P ≤ 0.05) and relieved myofiber atrophy (−33%) by reducing Atrogin‐1 and MurF‐1 transcripts (P ≤ 0.002), despite of a two‐fold increase in FoxO3 protein levels (P = 0.03). Atrophy attenuation by exogenous melusin did not result from rescue of Akt, ERK, or focal adhesion kinase activity, because it persisted after co‐transfection with dominant‐negative kinase forms (P < 0.01). Conversely, melusin cDNA transfection, combined with 7‐nitroindazole treatment or with cDNA transfection of the nNOS‐interacting chaperone Grp94, abolished 7 day unloaded myofiber atrophy.ConclusionsDisuse/unloading‐induced loss of melusin is an early event in muscle atrophy which occurs independently from mitochondrial oxidative stress, nNOS redistribution, and FoxO3 activation. Only preservation of melusin levels and sarcolemmal nNOS localization fully prevented muscle mass loss, demonstrating that both of them act as independent, but complementary, master switches of muscle disuse atrophy.