Recent studies found that forkhead box protein O1 (FoxO1) does not only demonstrate important biological functions in cell proliferation, gluconeogenesis, energy metabolism, and oxidative stress, but it also plays a vital role in the remodeling process of bones. FoxO1 can regulate bone mass by affecting osteoblasts, osteoclasts, and precursor cells. In this article, we review the role of FoxO1 in bone metabolism and elucidate its underlying mechanism.
Bone and Bones ; metabolism ; Cell Proliferation ; Forkhead Box Protein O1 ; Humans ; Osteoblasts ; Osteoclasts

OBJECTIVE: To explore whether tumor suppressor gene Foxo1 and PTEN play a critical role in the tumorigenesis of mouse natural killer-cell lymphoma. METHODS: NKp46-iCre mice were crossed with mice carrying floxed Foxo1 alleles (Foxo1) as well as floxed PTEN alleles (PTEN) to generate mice in which Foxo1 and PTEN in NK cells were knock-out, referred as Foxo1PTEN. The growth and development of the mice and tumor formation were observed. The flow cytometry was used to detect the percentages of NK cells in main lymphatic organs. B16F10 metanoma model of tumor metastasis was utilized to investigate NK cell-mediated tumor surveillance in vivo after NK cells special deletion of Foxol and PTEN. RESULTS: The mouse model with NK cell-special Foxo1 and PTEN double knockout was established. Compared with control group (Foxo1PTEN mice), Foxo1PTEN mice were born alive and appeared to be healthy over a period of 46 weeks. No spontaneous tumor formation was observed at this stage. There were no significant differences in NK cell percentages of gated lymphocytes from various organs including blood, bone marrow, peripheral lymph node and spleen between Foxo1PTEN mice and Foxo1PTEN mice [PB: 4.76%±0.46% vs 4.17%±0.64% (P＞0.05, n=8); BM: 1.13%±0.23% vs 1.31%±0.10% (P＞0.05, n=8) ; LN: 0.50%±0.10% vs 0.85%±0.20% (P＞0.05, n=8); SP: 4.41%±0.65% vs 3.50%±0.24% (P＞0.05, n=8)]. B16F10 melanoma metastasis model of tumor was established, No differences in median survival time were observed in the 2 types of mice (P＞0.05, n=13). CONCLUSION The simultaneous deletion of the Foxo1 and PTEN genes may not plays significant role in the tumorigenesis of mouse natural killer-cell lymphoma and NK cell-mediated tumor surveillance in vivo.
Animals ; Cell Transformation, Neoplastic ; Forkhead Box Protein O1 ; Genes, Tumor Suppressor ; Killer Cells, Natural ; Lymphoma ; Mice ; Mice, Knockout

OBJECTIVE: To investigate effects of berberine (BBR) on cholesterol synthesis in HepG2 cells with free fatty acid (FFA)-induced steatosis and to explore the underlying mechanisms. METHODS: A steatosis cell model was induced in HepG2 cell line fed with FFA (0.5 mmol/L, oleic acid:palmitic acid = 2:1), and then treated with three concentrations of BBR; cell viability was assessed with cell counting kit-8 assays. Lipid accumulation in cells was observed through oil red O staining and total cholesterol (TC) content was detected by TC assay. The effects of BBR on cholesterol synthesis mediators were assessed by Western blotting and quantitative polymerase chain reaction. In addition, both silent information regulator 1 (SIRT1) and forkhead box transcription factor O1 (FoxO1) inhibitors were employed for validation. RESULTS: FFA-induced steatosis was successfully established in HepG2 cells. Lipid accumulation and TC content in BBR groups were significantly lower (P < 0.05, P < 0.01), associated with significantly higher mRNA and protein levels of SIRT1(P < 0.05, P < 0.01), significantly lower sterol regulatory element-binding protein 2 (SREBP2) and 3-hydroxy 3-methylglutaryl-CoA reductase levels (P < 0.05, P < 0.01), as well as higher Acetyl-FoxO1 protein level (P < 0.05, P < 0.01) compared to the FFA only group. Both SIRT1 inhibitor SIRT1-IN-1 and FoxO1 inhibitor AS1842856 blocked the BBR-mediated therapeutic effects. Immunofluorescence showed that the increased SIRT1 expression increased FoxO1 deacetylation, and promoted its nuclear translocation. CONCLUSION BBR can mitigate FFA-induced steatosis in HepG2 cells by activating SIRT1-FoxO1-SREBP2 signal pathway. BBR may emerge as a potential drug candidate for treating nonalcoholic hepatic steatosis.
Berberine/pharmacology* ; Cholesterol ; Forkhead Box Protein O1/genetics* ; Humans ; Non-alcoholic Fatty Liver Disease/drug therapy* ; Sirtuin 1/genetics* ; Sterol Regulatory Element Binding Proteins

Silent information regulator factor 2-related enzyme 1 (Sirtuins 1, SIRT1) is a nicotinamide adenine dinucleotide (NAD)-dependent deacetylase, which can deacetylate histone and non-histone proteins and other transcription factors, and is involved in the regulation of many physiological functions, including gene transcription, energy metabolism, cell senescence and oxidative stress. Recent studies show that through adjusting the activity of endothelial nitric oxide syntheses (eNOS), p53, forkhead box class O (FOXO) and nuclear factor kappa B (NF-kappaB), SIRT1 can protect the functions of vascular endothelia and nerves in a variety of pathological conditions. Therefore, SIRT1 may be used as a potential therapeutic target of these diseases, particularly erectile dysfunction, which are associated with endothelial dysfunction.
Endothelium, Vascular ; physiology ; Erectile Dysfunction ; Forkhead Box Protein O1 ; Forkhead Transcription Factors ; metabolism ; Humans ; Male ; NAD ; metabolism ; NF-kappa B ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Oxidative Stress ; Sirtuin 1 ; physiology ; Tumor Suppressor Protein p53 ; metabolism

OBJECTIVETo explore the expression of miR-135b in endometrial carcinoma and the mechanism by which miR-135b promotes the proliferation of endometrial cancer cells.

METHODSThe expressions of miR-135b and FOXO1 were using RT-PCR detected in 22 fresh endometrial cancer tissues and paired adjacent tissues and also in endometrial cancer cell lines JEC, Ishikawa, HEC-1-B, and RL-952. The RL-952 and Ishikawa cell lines were transfected with miR-135b mimics or inhibitors, and the changes in their proliferative activity were detected with MTT assay; the expressions of FOXO1 mRNA and protein were detected by RT-PCR and Western blotting, respectively.

RESULTSThe expression of miRNA135b was significantly up-regulated and FOXO1 expression was down-regulated in endometrial carcinoma tissues as compared with the adjacent tissues (P<0.05). The mRNA expression of miR-135b was negatively correlated with the expression of FOXO1 in endometrial carcinoma. In RL-952 and Ishikawa cell lines, transfection with miR-135b mimics obviously promoted the cell proliferation (P<0.05). Up-regulation of miR-135b significantly decreased the expressions of FOXO1 protein and mRNA (P<0.05), and down- regulation of miR-135b increased FOXO1 expressions (P<0.05).

CONCLUSIONSMiR-135b plays an important role in the occurrence and development of endometrial carcinoma partially by regulating its target gene FOXO1.

Cell Line, Tumor ; Cell Proliferation ; Down-Regulation ; Endometrial Neoplasms ; genetics ; metabolism ; Female ; Forkhead Box Protein O1 ; Forkhead Transcription Factors ; genetics ; metabolism ; Gene Expression Regulation, Neoplastic ; Humans ; MicroRNAs ; genetics ; metabolism ; RNA, Messenger ; Transfection ; Up-Regulation

OBJECTIVETo investigate the effect of Metformin on the proliferation and collagen synthesis of the human keloids fibroblasts as well as the effect on phosphorylation of Akt/FoxO1 signal transduction pathway.

METHODSFibroblasts of keloid were divided into control group treated with medium solution and experimental groups treated with different concentrations of Metformin. 48 h later CCK-8 assay was adopted to evaluate cell survival; Western blot was performed to detect the Akt and FoxO1 phosphorylation; and Hydroxyproline reagent kit was used to detect the collagen synthesis.

RESULTSWith different concentrations (30, 60, 90, 120 mmol/L) of Metformin, the absorbance of cultured keloid fibroblasts detected by CCK8 assay decreased by (13.30 ± 2.04)%, (22.64 ± 4.70)%, (54.00 ± 5.34)% and (63.12 ± 3.48)%. The growth of fibroblasts was suppressed by Metformin in a dose-dependent manner. It showed that the level of phoshpo-akt and phoshpo-foxOl in keloids fibroblasts in experimental groups was lower than that in the control group and the collagen synthesis were also decreased in experimental groups, all in a dose-dependent manner (P < 0.05, P < 0.01).

CONCLUSIONSMetformin can effectively inhibit the proliferation and collagen synthesis of the human keloids fibroblasts in vitro, which may be associated with the suppression of phosphorylation of Akt/FoxO1 signaling pathway

Cell Proliferation ; drug effects ; Collagen ; biosynthesis ; Dose-Response Relationship, Drug ; Fibroblasts ; cytology ; drug effects ; metabolism ; Forkhead Box Protein O1 ; Forkhead Transcription Factors ; metabolism ; Humans ; Keloid ; pathology ; Metformin ; pharmacology ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction ; drug effects

OBJECTIVE: In this study, the combined effect of two stressors, namely, electromagnetic fields (EMFs) from mobile phones and fructose consumption, on hypothalamic and hepatic master metabolic regulators of the AMPK/SIRT1-UCP2/FOXO1 pathway were elucidated to delineate the underlying molecular mechanisms of insulin resistance. METHODS: Weaned Wistar rats (28 days old) were divided into 4 groups: Normal, Exposure Only (ExpO), Fructose Only (FruO), and Exposure and Fructose (EF). Each group was provided standard laboratory chow ad libitum for 8 weeks . Additionally, the control groups, namely, the Normal and FruO groups, had unrestricted access to drinking water and fructose solution (15%), respectively. Furthermore, the respective treatment groups, namely, the ExpO and EF groups, received EMF exposure (1,760 MHz, 2 h/day x 8 weeks). In early adulthood, mitochondrial function, insulin receptor signaling, and oxidative stress signals in hypothalamic and hepatic tissues were assessed using western blotting and biochemical analysis. RESULT: In the hypothalamic tissue of EF, SIRT1, FOXO 1, p-PI3K, p-AKT, Complex III, UCP2, MnSOD, and catalase expressions and OXPHOS and GSH activities were significantly decreased ( P < 0.05) compared to the Normal, ExpO, and FruO groups. In hepatic tissue of EF, the p-AMPKα, SIRT1, FOXO1, IRS1, p-PI3K, Complex I, II, III, IV, V, UCP2, and MnSOD expressions and the activity of OXPHOS, SOD, catalase, and GSH were significantly reduced compared to the Normal group ( P < 0.05). CONCLUSION The findings suggest that the combination of EMF exposure and fructose consumption during childhood and adolescence in Wistar rats disrupts the closely interlinked and multi-regulated crosstalk of insulin receptor signals, mitochondrial OXPHOS, and the antioxidant defense system in the hypothalamus and liver.
Humans ; Rats ; Animals ; Adult ; Rats, Wistar ; Fructose/metabolism* ; Catalase ; Receptor, Insulin/metabolism* ; AMP-Activated Protein Kinases/metabolism* ; Electromagnetic Fields/adverse effects* ; Sirtuin 1/metabolism* ; Cell Phone ; Phosphatidylinositol 3-Kinases/metabolism* ; Forkhead Box Protein O1/metabolism* ; Uncoupling Protein 2

Physalin B (PB), one of the major active steroidal constituents of Solanaceae Physalis plants, has a wide variety of biological activities. We found that PB significantly down-regulated β-amyloid (Aβ) secretion in N2a/APPsw cells. However, the underlying mechanisms are not well understood. In the current study, we investigated the changes in key enzymes involved in β-amyloid precursor protein (APP) metabolism and other APP metabolites by treating N2a/APPsw cells with PB at different concentrations. The results indicated that PB reduced Aβ secretion, which was caused by down-regulation of β-secretase (BACE1) expression, as indicated at both the protein and mRNA levels. Further research revealed that PB regulated BACE1 expression by inducing the activation of forkhead box O1 (FoxO1) and inhibiting the phosphorylation of signal transducer and activator of transcription 3 (STAT3). In addition, the effect of PB on BACE1 expression and Aβ secretion was reversed by treatment with FoxO1 siRNA and STAT3 antagonist S3I-201. In conclusion, these data demonstrated that PB can effectively down-regulate the expression of BACE1 to reduce Aβsecretion by activating the expression of FoxO1 and inhibiting the phosphorylation of STAT3.
Alzheimer Disease ; Amyloid Precursor Protein Secretases/metabolism* ; Amyloid beta-Peptides/metabolism* ; Aspartic Acid Endopeptidases/metabolism* ; Down-Regulation ; Forkhead Box Protein O1/genetics* ; Humans ; Phosphorylation ; STAT3 Transcription Factor/metabolism* ; Secosteroids

To explore the role of forkhead box protein O1 (FOXO1) in the progression of glioblastoma multiforme (GBM) and related drug resistance, we deciphered the roles of FOXO1 and miR-506 in proliferation, apoptosis, migration, invasion, autophagy, and temozolomide (TMZ) sensitivity in the U251 cell line using in vitro and in vivo experiments. Cell viability was tested by a cell counting kit-8 (CCK8) kit; migration and invasion were checked by the scratching assay; apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining and flow cytometry. The construction of plasmids and dual-luciferase reporter experiment were carried out to find the interaction site between FOXO1 and miR-506. Immunohistochemistry was done to check the protein level in tumors after the in vivo experiment. We found that the FOXO1-miR-506 axis suppresses GBM cell invasion and migration and promotes GBM chemosensitivity to TMZ, which was mediated by autophagy. FOXO1 upregulates miR-506 by binding to its promoter to enhance transcriptional activation. MiR-506 could downregulate E26 transformation-specific 1 (ETS1) expression by targeting its 3'-untranslated region (UTR). Interestingly, ETS1 promoted FOXO1 translocation from the nucleus to the cytosol and further suppressed the FOXO1-miR-506 axis in GBM cells. Consistently, both miR-506 inhibition and ETS1 overexpression could rescue FOXO1 overactivation-mediated TMZ chemosensitivity in mouse models. Our study demonstrated a negative feedback loop of FOXO1/miR-506/ETS1/FOXO1 in GBM in regulating invasiveness and chemosensitivity. Thus, the above axis might be a promising therapeutic target for GBM.
Animals ; Mice ; Brain Neoplasms/genetics* ; Cell Line, Tumor ; Cell Proliferation ; Drug Resistance, Neoplasm ; Feedback ; Gene Expression Regulation, Neoplastic ; Glioblastoma/metabolism* ; MicroRNAs/metabolism* ; Temozolomide/therapeutic use* ; Humans ; Forkhead Box Protein O1/metabolism*

OBJECTIVETo detect the PAX3/PAX7-FKHR fusion transcripts to identify genetic alteration in embryonal rhabdomyosarcoma (ERMS) and alveolar rhabdomyosarcoma (ARMS) tissues.

METHODSOne-step reverse transcription- polymerase chain reaction (RT-PCR) were used to detect the expression of the PAX3/PAX7-FKHR fusion transcrips in 16 cases of rhabdomyosarcoma (7 cases of ARMS, 9 cases of ERMS) and 16 specimens were compared to the surrounding normal tissue. Comparative genomic hybridization (CGH) was employed to detect the genomic imbalance (DNA loss or amplification) in 16 RMS cases.

RESULTSPAX3-FKHR fusion transcripts were positive in 3/7 and PAX 7-FKHR fusion transcripts were positive in 2/7 of ARMS patients, respectively, and were all negative in ERMS and Control tumors. There were different chromosome variations for each RMS, chromosome amplification was frequently seen in 1p36 (69%), 5q32 (56%), 8q21 (63%), 13q14 (69%), 19q (63%), 20q (56%). Chromosome loss was frequently seen in 3p21-pter (56%), 9p23-pter (50%), 10q (69%), 16/16q24 (56%).

CONCLUSIONOne-step RT-PCR assay for detection specific fusion gene provides a useful tool for confirmation of the diagnosis of RMS in diagnostically difficult cases and in retrospective studies. Chimeric gene transcript resulting from specific chromosomal translocations is a reliable index for the molecular diagnosis of RMS.

Chromosome Aberrations ; Comparative Genomic Hybridization ; Forkhead Box Protein O1 ; Forkhead Transcription Factors ; genetics ; Gene Expression Regulation, Neoplastic ; Humans ; Oncogene Proteins, Fusion ; genetics ; PAX3 Transcription Factor ; PAX7 Transcription Factor ; genetics ; Paired Box Transcription Factors ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Rhabdomyosarcoma ; genetics