Activation Of FOXO3a Research Articles

Skeletal muscle fibre type-dependent effects of atorvastatin on the PI3K/Akt/mTOR signalling pathway and atrophy-related genes in rats

BackgroundOne of the probable causes of statin myotoxicity is an imbalance between protein synthesis and degradation. These processes are regulated by the PI3K/Akt/mTOR pathway and the ubiquitin‒proteasome system (UPS). The aim of this study was to assess whether the effects of atorvastatin on PI3K/Akt/mTOR pathway downstream proteins, the FoxO3a transcription factor and the UPS genes, i.e., MuRF-1 and MAFbx, depend on muscle fibre type.Methods and resultsAtorvastatin (50 mg/kg) was administered to Wistar rats. The levels of selected PI3K/Akt/mTOR pathway proteins were assayed via Western blotting, whereas MuRF-1, MAFbx and FoxO3a mRNA levels were measured using reverse transcription quantitative polymerase chain reaction (RT‒qPCR). Gomöri trichrome staining was performed to assess skeletal muscle pathology. A decrease in the P-Akt/Akt ratio was observed in the gastrocnemius muscle (MG), whereas an increase in the P-Akt/Akt ratio was observed in the soleus muscle (SOL). FoxO3a gene expression increased in the SOL and extensor digitorum longus (EDL) muscles. MuRF-1 gene expression increased in the MG, and MAFbx expression increased in the EDL. No histopathological changes were observed in any of the tested muscles.ConclusionsIn the absence of overt muscle damage, atorvastatin decreased the P-Akt/Akt ratio in the MG, indicating an increase in inactive Akt. Consistent with the decrease in Akt activation, rpS6 phosphorylation decreased. In SOL, atorvastatin increased the P-Akt/Akt ratio, indicating Akt activation. P-FoxO3a and the P-FoxO3a/FoxO3a ratio increased, suggesting that FoxO3a inactivation occurred. Moreover, in the SOL, atorvastatin did not affect the expression of atrophy-related genes. These findings indicate that atorvastatin has no adverse effect on the Akt pathway in the SOL. Our results showed that the effects of atorvastatin on the Akt signalling pathway and atrophy-related gene expression depend on muscle type.

Alterations in FoxO3a, NF-κB, and MuRF1 Expression in the Soleus Muscle of Male Rats Following High-Intensity Interval Training and Detraining.

Activation of the transcription factors FoxO3a and NF-κB is necessary for muscle atrophy, which occurs during cancer cachexia and detraining. It is not known how high-intensity interval training (HIIT) and detraining affect activation of these pathways. Two-month-old male Sprague-Dawley rats were assigned to sedentary control (SC) (n = 6) and HIIT (HIIT) (n = 18) groups. The HIIT group was divided into three subgroups: HIIT (n = 6), HIIT + 7-day detraining (n = 6), and HIIT + 14-day detraining (n = 6). The expression of FoxO3a, NF-κB, MuRF1, and PGC-1α in the soleus muscle was examined by RT-PCR using CYBR Green. The 2-Ct, Livak method was used to calculate the changes in data expression. The soleus muscle mass increased after HIIT (35.10%) and decreased after 7- and 14-day of detraining (15 and 21%, respectively). The mRNA expression levels of NF-κB, MuRF1, and PGC1α in the soleus muscle were upregulated, and FoxO3a levels were significantly lower in the HIIT group compare to the SC group (p = 0.001). Taken together, the activity of the FoxO3a/MuRF1 pathway, but not NF-κB /MuRF1, can promote atrophy due to detraining, and MuRF1 is not always a good marker of atrophy.

Discovery of Potent Covalent CRM1 Inhibitors Via a Customized Structure-Based Virtual Screening Pipeline and Bioassays.

CRM1 (chromosomal region maintenance 1, also referred to as exportin 1 or XPO1) plays a crucial role in maintaining the appropriate nuclear levels of tumor suppressor proteins (TSPs), growth regulatory proteins (GRPs), and antiapoptotic proteins, thereby contributing significantly to their anticancer effects. Dysregulation of CRM1-mediated nuclear transport, observed in a range of cancers such as colon cancer as well as autoimmune diseases, highlights its significance in various disease processes. In this paper, we employed a customized structure-based virtual screening campaign to search for novel covalent CRM1 inhibitors and purchased 50 potentially active compounds for in vitro bioassays. Among these candidates, AN-988 displayed a notably higher binding affinity (KD = 615 nM) toward CRM1, as determined by the biolayer interferometry (BLI) assay. Furthermore, AN-988 exhibited a strong suppression of colorectal cancer cell proliferation and remarkable anti-inflammatory effects. Notably, AN-988 induced cell apoptosis and cell cycle arrest in a time- and dose-dependent manner by effectively inhibiting the translocation of FOXO3a from the nucleus to the cytosol, thereby preserving the activity of FOXO3a. Collectively, our study identified AN-988 as a promising CRM1 inhibitor, underscoring its potential as a preclinical colon cancer therapy candidate.

Alleviation of Copper-Induced Hepatotoxicity by Bergenin: Diminution of Oxidative Stress, Inflammation, and Apoptosis via Targeting SIRT1/FOXO3a/NF-κB Axes and p38 MAPK Signaling.

Despite its biological importance, excess copper induces organ damage, especially to the liver. Disruption of critical signaling cascades that control redox status, inflammatory responses, and cellular apoptosis significantly contributes to the copper-induced hepatotoxicity. The present work explored the hepatoprotective ability of bergenin against the copper-induced hepatotoxicity using male Wistar rats as a mammalian model. The results revealed that bergenin suppressed the copper-evoked histopathological changes and hepatocellular necrosis as indicated by decreased activity of the liver enzymes ALT and AST in the sera of the copper-intoxicated rats. It decreased hepatic copper content and the copper-induced oxidative stress as revealed by reduced lipid peroxidation and improved activity of the antioxidant enzymes thioredoxin reductase, glutathione peroxidase, catalase, and superoxide dismutase. Bergenin downregulated the inflammatory cytokines TNF-α and IL-6, and the inflammatory cell infiltration to the liver tissues. Additionally, it inhibited the copper-induced apoptosis as indicated by significant reduction in caspase-3 activity. At the molecular level, bergenin activated the antioxidant transcription factor FOXO3a, inhibited the nuclear translocation of the inflammatory transcription factor NF-κB, and suppressed the inflammatory signaling molecules p38 MAPK and c-Fos. Interestingly, bergenin improved the expression of the anti-apoptotic protein Bcl2 and reduced the pro-apoptotic protein BAX. Bergenin markedly enhanced the expression of the histone deacetylase protein SIRT1 that regulates activity of NF-κB and FOXO3a. Collectively, these findings highlight the alleviating activity of bergenin against the copper-induced hepatotoxicity via controlling oxidative stress, inflammation, and apoptosis potentially through upregulation of SIRT1, activation of FOXO3a along with suppression of NF-κB and p38 MAPK signaling.

Abstract C030: The Wip1 phosphatase activator QGC-8-52 selectively sensitizes p53-deficient cancer cells to chemotherapy

Abstract PP2C serine-threonine phosphatase Wip1 is vital for tissue homeostasis, stress signaling, and the pathogenesis of various diseases, making it a promising target for cancer therapy. Inhibiting Wip1's expression or activity is a novel strategy to prevent cancer. However, traditional Wip1 suppression may not work in cancers lacking p53. Here, we evaluated a new Wip1 activator, QGC-8-52, in preclinical breast cancer models. QGC-8-52 sensitizes p53-deficient cancer cells to chemotherapy by facilitating Wip1-FOXO3a interaction and dephosphorylation of Thr487, which enhances FOXO3a's activity on the proapoptotic TRAIL gene. This effect is specific to p53-deficient cancer cells. In normal cells, Wip1 activation reduces drug-induced apoptosis by weakening upstream signaling to p53. Thus, activating Wip1 during chemotherapy boosts apoptosis in p53-negative tumors and protects normal tissues. Our findings highlight Wip1 activation as a potentially effective and safe treatment for p53-deficient cancers. Citation Format: Ke Wu, Yong Wu, Jay Vadgama, Qiao-Hong Chen, Zhi-min Huang, Qun Li. The Wip1 phosphatase activator QGC-8-52 selectively sensitizes p53-deficient cancer cells to chemotherapy [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C030.

NMR 1H, 13C, 15N backbone resonance assignments of 14-3-3ζ binding region of human FOXO3a (residues 1-284)

In tumors, mutation in Ras proteins stimulates a signaling cascade through phosphorylation. Downstream of the cascade, many transcription and translation factors are up- or down-regulated by phosphorylation, leading to cancer progression. This phosphorylation cascade is sustained by 14-3-3ζ protein. 14-3-3ζ binds to its client proteins that are Ser/Thr-phosphorylated and prevents their dephosphorylation. One of those transcription factors is FOXO3a, whose transcriptional activity is suppressed in the phosphorylation cascade. FOXO3a binds to specific DNA sequences and activates the transcription of apoptosis-related proteins. In cancer cells, however, FOXO3a is phosphorylated, bound to 14-3-3ζ, and dissociated from the DNA, resulting in FOXO3a inactivation. To elucidate the mechanism of FOXO3a inactivation by the 14-3-3ζ binding, we aim to perform NMR analysis of the interaction between 14-3-3ζ and di-phosphorylated FOXO3a residues 1-284 (dpFOXO3a). Here, we report the backbone resonance assignments of dpFOXO3a, which are transferred from those of the N-terminal domain (NTD) and the DNA-binding domain (DBD) of dpFOXO3a.

Polyphenol-rich Aronia melanocarpa juice sustains eNOS activation through phosphorylation and expression via redox-sensitive pathways in endothelial cells.

A sustained formation of nitric oxide (NO) by endothelial nitric oxide synthase (eNOS) is crucial to safeguard the vascular system against the development of cardiovascular diseases. This study investigated the prolonged phosphorylation and expression of eNOS induced by polyphenol-rich Aronia melanocarpa juice (AMJ), along with its underlying mechanisms. The findings revealed that AMJ triggered concentration- and time-dependent increases in eNOS phosphorylation and expression, leading to sustained NO production for 15h. Investigations with various enzymes and inhibitors revealed that the effect of AMJ was associated with redox sensitivity, activating the PI3-kinase/Akt, JNK, and p38 MAPK pathways. These pathways led to the inactivation of transcription factors FoxO1 and FoxO3a through phosphorylation, relieving their repression on eNOS expression. Therefore, the capability of AMJ to consistently trigger prolonged eNOS phosphorylation and expression via complex redox-sensitive pathways highlights its potential for maintaining vascular health and preventing cardiovascular diseases.

Blocking of SIRT7/FOXO3a axis by miR-152-3p enhances cisplatin sensitivity in breast cancer

BackgroundCisplatin-based chemoresistance is major obstacle for breast cancer (BC) including Triple-negative breast cancer (TNBC). SIRT7 is reportedly involved in the progression of BC, the underlining mechanism in Cisplatin-based chemoresistance in BC remains unclear. This work is to elucidate effects of SIRT7 on cisplatin resistance in breast cancer regulated by miR-152-3p. MethodsThe RNA expression of SIRT7 and miRNAs in breast cancer were available from TCGA database. SIRT7-targeted miRNAs were predicted by TargetScan, miRanda, miRDB databases. The association of SIRT7 expression with predicted miRNA was validated by Luciferase assay. Cell apoptosis was determined by Flow cytometry. Cell viability was detected by CCK8 assay. The mRNA expression was measured by quantitative real-time polymerase chain reaction (qRT-PCR) assay. Protein expression was determined by Western blotting assay. ResultsSIRT7 mRNA levels were dramatically enhanced in BC tissues compared to para-carcinoma tissues, also increased in BC patients with Cisplatin-based chemotherapy containing TNBC compared with those without. The increase of SIRT7 expression was obviously relevant to shorter survive time of them. Importantly, SIRT7 inhibition facilitated Cisplatin-induced cell apoptosis of TNBC (MDA-MB-231 and MDA-MB-468) and non- TNBC (MCF-7). Notably, miR-152-3p was predicted as a negative regulator of SIRT7 by overlapping downregulated miRNAs in BC patients treated with Cisplatin-based chemotherapy and miRNAs to target SIRT7. Mechanically, miR-152-3p blocked SIRT7 to stimulate an activation of FOXO3a, cleaved PARP1 and Caspase-3, sensitizing Cisplatin-induced apoptosis of BC cells. ConclusionsInhibition of SIRT7 by miR-152-3p may be a promising strategy against the resistance to cisplatin-based chemotherapy in BC containing TNBC.

A novel iheyamine A derivative L42 suppresses acute myeloid leukemia via dual regulation of the PI3K/AKT/FOXO3a axis and TNF signaling pathway

Acute myeloid leukemia (AML) is one of the most common hematopoietic malignancies and the development of new drugs is crucial for the treatment of this lethal disease. Iheyamine A is a nonmonoterpenoid azepinoindole alkaloid from the ascidian Polycitorella sp., and its anticancer mechanism has not been investigated in leukemias. Herein, we showed the significant antileukemic activity of L42 in AML cell lines HEL, HL-60 and THP-1. The IC50 values were 0.466±0.099 µM, 0.356±0.023 µM, 0.475±0.084 µM in the HEL, HL-60 and THP-1 cell lines, respectively, which were lower than the IC50 (2.594±0.271 µM) in the normal liver cell line HL-7702. Furthermore, L42 significantly inhibited the growth of peripheral blood mononuclear cells (PBMCs) from an AML patient. In vivo, L42 effectively suppressed leukemia progression in a mouse model induced by Friend murine leukemia virus (F-MuLV). Mechanistically, we showed that L42 induced cell cycle arrest and apoptosis in leukemia cell lines. RNA sequencing analysis of L42-treated THP-1 cells revealed that the differentially expressed genes (DEGs) were enriched in the cell cycle and apoptosis and predominantly enriched in the PI3K/AKT pathway. Accordingly, L42 decreased the expression of the phospho-PI3K (p85), phospho-AKT and phospho-FOXO3a. Docking and CETSA analysis indicated that L42 bound to the PI3K isoform p110α (PIK3CA), which was implicated in the suppression of the PI3K/AKT pathway. L42 was also shown to initiate the TNF signaling-mediated apoptosis. Moreover, L42 exhibited stronger anti-leukemia activity and sensitivity in IDH2-mutant HEL cells than in IDH2-wild-type control. In conclusion, L42 effectively suppresses cell proliferation and triggers apoptosis in AML cell lines in part through inhibition of the PI3K/AKT signaling pathway to restore FOXO3a expression and activation of the TNF signaling pathway. Thus, the iheyamine A derivative L42 represents a novel candidate for AML therapy.

Microglial forkhead box O3a deficiency attenuates LPS-induced neuro-inflammation and depressive-like behaviour through regulating the expression of peroxisome proliferator-activated receptor-γ.

Depression is closely linked with microglial activation and neuro-inflammation. Peroxisome proliferator-activated receptor-γ (PPAR-γ) plays an important role in M2 activation of microglia. Forkhead box (FOX) O3a has been implicated in the regulation of mood-relevant behaviour. However, little is known about the inflammatory mechanisms of in the microglia of the brain. Here, we have investigated the role of microglial FOXO3a/PPAR-γ in the development of depression. The effect of FOXO3a on microglia inflammation was analysed in vitro and in lipopolysaccharide (LPS)-induced depression-like behaviours in vivo. ChIP-seq and Dual-luciferase reporter assays were used to confirm the interaction between FOXO3a and PPAR-γ. Behavioural changes were measured, while inflammatory cytokines, microglial phenotype and morphological properties were determined by ELISA, qRT-PCR, western blotting and immunostaining. Overexpression of FOXO3a significantly attenuated expression of PPAR-γ and enhanced the microglial polarization towards the M1 phenotype, while knockdown of FOXO3a had the opposite effect. FOXO3a binds to the promoters of PPAR-γ and decreases its transcription activity. Importantly, deacetylation and activation of FOXO3a regulate LPS-induced neuro-inflammation by inhibiting the expression of PPAR-γ in microglia cells, supporting the antidepressant potential of histone deacetylase inhibitors. Microglial FOXO3a deficiency in mice alleviated LPS-induced neuro-inflammation and depression-like behaviours but failed to reduce anxiety behaviour, whereas pharmacological inhibition of PPAR-γ by GW9662 restored LPS-induced microglial activation and depressive-like behaviours in microglial FOXO3a-deficient mice. FOXO3a/PPAR-γ axis plays an important role in microglial activation and depression, identifying a new therapeutic avenue for the treatment of major depression.

Oxidative DNA damage promotes vascular aging associated with changes in extracellular matrix-regulating proteins.

Vascular aging is characterized by vessel stiffening, with increased deposition of extracellular matrix (ECM) proteins including collagens. Oxidative DNA damage occurs in vascular aging, but how it regulates ECM proteins and vascular stiffening is unknown. We sought to determine the relationship between oxidative DNA damage and ECM regulatory proteins in vascular aging. We examined oxidative DNA damage, the major base excision repair (BER) enzyme 8-Oxoguanine DNA Glycosylase (Ogg1) and its regulators, multiple physiological markers of aging, and ECM proteomics in mice from 22-72w. Vascular aging was associated with increased oxidative DNA damage, and decreased expression of Ogg1, its active acetylated form, its acetylation regulatory proteins P300 and CBP, and the transcription factor Foxo3a. Vascular stiffness was examined in vivo in control, Ogg1-/-, or mice with vascular smooth muscle cell-specific expression of Ogg1+ (Ogg1) or an inactive mutation (Ogg1KR). Ogg1-/- and Ogg1KR mice showed reduced arterial compliance and distensibility, and increased stiffness and pulse pressure, whereas Ogg1 expression normalised all parameters to 72w. ECM proteomics identified major changes in collagens with aging, and downregulation of the ECM regulatory proteins Protein 6-lysyl oxidase (LOX) and WNT1-inducible-signaling pathway protein 2 (WISP2). Ogg1 overexpression upregulated LOX and WISP2 both in vitro and in vivo, and downregulated Transforming growth factor β1 (TGFb1) and Collagen 4α1 in vivo compared with Ogg1KR. Foxo3a activation induced Lox, while Wnt3 induction of Wisp2 also upregulated LOX and Foxo3a, and downregulated TGFβ1 and fibronectin 1. In humans, 8-oxo-G increased with vascular stiffness, while active OGG1 reduced with both age and stiffness. Vascular aging is associated with oxidative DNA damage, downregulation of major BER proteins, and changes in multiple ECM structural and regulatory proteins. Ogg1 protects against vascular aging, associated with changes in ECM regulatory proteins including LOX and WISP2.

Anti-Müllerian hormone induces autophagy to preserve the primordial follicle pool in mice.

The reserve pool of primordial follicles (PMFs) is finely regulated by molecules implicated in follicular growth or PMF survival. Anti-Müllerian hormone (AMH), produced by granulosa cells of growing follicles, is known for its inhibitory role in the initiation of PMF growth. We observed in a recent invivo study that injection of AMH into mice seemed to induce an activation of autophagy. Furthermore, injection of AMH into mice activates the transcription factor FOXO3A which is also known for its implication in autophagy regulation. Many studies highlighted the key role of autophagy in the ovary at different stages of folliculogenesis, particularly in PMF survival. Through an invitro approach with organotypic cultures of prepubertal mouse ovaries, treated or not with AMH, we aimed to understand the link among AMH, autophagy, and FOXO3A transcription factor. Autophagy and FOXO3A phosphorylation were analyzed by western blot. The expression of genes involved in autophagy was quantified by RT-qPCR. In our invitro model, we confirmed the decrease in FOXO3A phosphorylation and the induction of autophagy in ovaries incubated with AMH. AMH also induces the expression of genes involved in autophagy. Interestingly, most of these genes are known to be FOXO3A target genes. In conclusion, we have identified a new role for AMH, namely the induction of autophagy, probably through FOXO3A activation. Thus, AMH protects the ovarian reserve not only by inhibiting the growth of PMFs but also by enabling their survival through activation of autophagy.

PI3K/AKT/FOXO3a Pathway Induces Muscle Atrophy by Ubiquitin-Proteasome System and Autophagy System in COPD Rat Model.

Muscle atrophy is a common extrapulmonary co-morbidity affecting about 20% of patients with COPD. However, the mechanism of muscle atrophy in COPD remains unclear. This study investigated the role of the ubiquitin-proteasome system (UPS) and the autophagy system in COPD muscle atrophy and its mechanism. A COPD rat model was established to evaluate the in vitro effects of the UPS and the autophagy system in muscle atrophy. In addition, the role of the UPS, autophagy systems, and the expressions of the PI3K/AKT/FOXO3a pathway were studied in the CSE-induced L6 myoblast cells. Furthermore, we evaluated the effect of FOXO3a in the CSE-induced L6 myoblast cells using siRNA-FOXO3a. The results showed that the expression of ubiquitin-related proteins and autophagy-related proteins were significantly increased in the COPD rat model and CSE-induced L6 myoblast cells. At the same time, there was a concurrent decrease in the phosphorylation protein expression of PI3K and AKT, but the transcriptional activity of FOXO3a was increased in CSE-induced L6 myoblast cells. And siRNA-FOXO3a significantly decreased the expression level of the UPS and the autophagy system in CSE-induced L6 myoblast cells. These results suggest that PI3K/AKT/FOXO3a participates in COPD muscle atrophy by regulating the UPS and the autophagy systems.

Linagliptin, a DPP-4 inhibitor, activates AMPK/FOXO3a and suppresses NFκB to mitigate the debilitating effects of diethylnitrosamine exposure in rat liver: Novel mechanistic insights.

Accumulating evidence suggests that dysregulation of FOXO3a plays a significant role in the progression of various malignancies, including hepatocellular carcinoma (HCC). FOXO3a inactivation, driven by oncogenic stimuli, can lead to abnormal cell growth, suppression of apoptosis, and resistance to anticancer drugs. Therefore, FOXO3a emerges as a potential molecular target for the development of innovative treatments in the era of oncology. Linagliptin (LNGTN), a DPP-4 inhibitor known for its safe profile, has exhibited noteworthy anti-inflammatory and anti-oxidative properties in previous invivo studies. Several potential molecular mechanisms have been proposed to explain these effects. However, the capacity of LNGTN to activate FOXO3a through AMPK activation has not been investigated. In our investigation, we examined the potential repurposing of LNGTN as a hepatoprotective agent against diethylnitrosamine (DENA) intoxication. Additionally, we assessed LNGTN's impact on apoptosis and autophagy. Following a 10-week administration of DENA, the liver underwent damage marked by inflammation and early neoplastic alterations. Our study presents the first experimental evidence demonstrating that LNGTN can reinstate the aberrantly regulated FOXO3a activity by elevating the nuclear fraction of FOXO3a in comparison to the cytosolic fraction, subsequent to AMPK activation. Moreover, noteworthy inactivation of NFκB induced by LNGTN was observed. These effects culminated in the initiation of apoptosis, the activation of autophagy, and the manifestation of anti-inflammatory, antiproliferative, and antiangiogenic outcomes. These effects were concomitant with improved liver function and microstructure. In conclusion, our findings open new avenues for the development of novel therapeutic strategies targeting the AMPK/FOXO3a signaling pathway in the management of chronic liver damage.

FOXO3a-regulated arginine metabolic plasticity adaptively promotes esophageal cancer proliferation and metastasis.

Esophageal squamous cell carcinoma (ESCC) is a common malignant tumor with a poor prognosis due to a lack of early detection. Indeed, the mechanisms underlying ESCC progression remain unclear. Here, we discovered that abnormal arginine metabolism contributes to ESCC progression. Based on transcriptomic and metabolomic analyses, we found that argininosuccinate synthetase 1 (ASS1) and argininosuccinate lyase (ASL) levels were increased in primary tumor tissues but decreased in lymph-metastatic tumor tissues. Intriguingly, FOXO3a was inversely correlated with ASS1 and ASL in primary and metastatic tumor tissues, suggesting that FOXO3a dissimilarly regulates ASS1 and ASL at different stages of ESCC. Silencing ASS1/ASL inhibited primary tumor growth and promoted metastasis. Conversely, overexpression of ASS1/ASL or increased arginine supply promoted tumor proliferation but suppressed metastasis. In addition, FOXO3a activation inhibited primary tumor growth by repressing ASS1 and ASL transcription, whereas inactivation of FOXO3a impeded metastasis by releasing ASS1 and ASL transcription. Together, the finding sheds light on metastatic reprogramming in ESCC.

Epigallocatechin gallate inhibits ovarian cancer cell growth and induces cell apoptosis via activation of FOXO3A.

Epigallocatechin gallate (EGCG), a bioactive component in tea, displays broad anti-cancer effects. Our study was designed to evaluate the anti-cancer effects of EGCG on ovarian cancer and explored the underlying molecular mechanisms. To evaluate the in vitro inhibitory effects of EGCG against ovarian cancer, MTT assay, colony formation assay, apoptosis assay, and wound healing assay, were performed. Besides, the inhibitory effects of EGCG on tumor growth in the xenograft animal model were evaluated by measuring tumor volume and tumor weight. Moreover, Western blotting and qPCR were used to evaluate the levels of target genes and proteins. Treatment with EGCG inhibited cell migration and cell survival, and promoted cell apoptosis in A2780 and SKOV3 cells. Interestingly, treatment with EGCG inhibited the tumor growth in the xenograft animal model. The mechanistic study revealed that treatment with EGCG induced the activation of FOXO3A and suppressed the expression of c-Myc both in vitro and in vivo. Our findings demonstrate that EGCG suppress ovarian cancer cell growth, which may be due to its regulation on FOXO3A and c-Myc.

Skeletal Muscle Type-Dependent Effect of Atorvastatin on FoxO3a and Akt in Hypercholesterolemic Rats

Statins are one of the most commonly used lipid-lowering drugs reducing the risk of mortality due to cardiovascular diseases. They are well tolerated and have relatively few side effects which mainly affect skeletal muscle. The impact of statins on skeletal muscle functions depends on the composition of the muscle fibers type. One of the mechanisms of statin-induced myopathy is imbalance between muscle protein synthesis and breakdown.Transcription factor FoxO3a is a key factor regulating muscle protein breakdown. The activity of FoxO3a is regulated namely by phosphorylation via PI3K/Akt pathway. Active, phosphorylated Akt catalyzes the phosphorylation and thus inactivation of FoxO3a. The purpose of our study was to evaluate the effect of atorvastatin on FoxO3a and Akt in different skeletal muscles in rats with diet-induced hypercholesterolemia. Atorvastatin (20 mg/kg b.w./day) or the vehicle was administered orally 21 days. FoxO3a, Akt and their phosphorylated protein levels were assayed by Western blot in gastrocnemius and soleus muscle. Additionally, muscle total protein level and serum CK activity were measured. In the gastrocnemius muscle atorvastatin decreased total FoxO3a and P-FoxO3a levels with no changes in Akt and P-Akt level. In contrast, in soleus muscle atorvastatin did not change the level of P-FoxO3a. However, total FoxO3a and the P-Akt level decreased. Serum CK activity did not change in both muscle under atorvastatin treatment. In conclusion, the results of our study indicate that atorvastatin affects FoxO3a and Akt in a muscle type-dependent manner.

Bifidobacterium bifidum and Lactobacillus paracasei alleviate sarcopenia and cognitive impairment in aged mice by regulating gut microbiota-mediated AKT, NF-κB, and FOXO3a signaling pathways

Sarcopenia is closely associated with gut dysbiosis. Probiotics alleviate gut dysbiosis. Therefore, we selected probiotics Lactobacillus paracasei P62 (Lp) and Bifidobacterium bifidum P61 (Bb), which suppressed muscle RING-finger protein-1 (MuRF1) expression and NF-κB activation in C2C12 cells, and examined their effects on muscle mass loss and dysfunction in aged mice. Oral administration of Lp, Bb, or their mix (LB) increased grip strength and treadmill running distance and time. They significantly increased muscle weight in aged mice. They also increased AKT activation, PGC1α, SIRT1, and myosin heavy chain (MyHC) expression, MyHC-positive cell population, and cell size in the gastrocnemius (GA) muscle, while FOXO3a and NF-κB activation, MuRF1, muscle atrophy F-box, and p16 expression, and NF-κB+CD11c+ cell population decreased. Furthermore, they reduced cognitive impairment-like behavior, IL-6 expression, FOXO3a activation, and NF-κB-positive cell population in the hippocampus, GA, and colon, while hippocampal brain-derived neurotropic factor expression increased. They shifted gut microbiota composition in aged mice: they increased Akkermansiaceae and Bacteroidaceae populations, which were positively correlated with total muscle weight and MyHC expression, and decreased Odoribacteraceae and Deferribacteriaceae populations, which were positively correlated with MuRF1 and IL-6 expression. LB alleviated sarcopenia- and cognitive impairment-like symptoms more potently than Lp or Bb alone. Based on these findings, probiotics, particularly Lp, Bb, and LB, can alleviate aging-dependent sarcopenia and cognitive impairment by regulating gut microbiota-mediated AKT, NF-κB, and/or FOXO3a signaling pathways.

Klotho increases antioxidant defenses in astrocytes and ubiquitin–proteasome activity in neurons

Klotho is an antiaging protein, and its levels decline with age and chronic stress. The exogenous administration of Klotho can enhance cognitive performance in mice and negatively modulate the Insulin/IGF1/PI3K/AKT pathway in terms of metabolism. In humans, insulin sensitivity is a hallmark of healthy longevity. Therefore, this study aimed to determine if exogenous Klotho, when added to neuronal and astrocytic cell cultures, could reduce the phosphorylation levels of certain insulin signaling effectors and enhance antioxidant strategies in these cells. Primary cell cultures of cortical astrocytes and neurons from mice were exposed to 1 nM Klotho for 24 h, with or without glucose. Klotho decreased pAKT and mTOR levels. However, in astrocytes, Klotho increased FOXO-3a activity and catalase levels, shielding them from intermediate oxidative stress. In neurons, Klotho did not alter FOXO-3 phosphorylation levels but increased proteasome activity, maintaining lower levels of PFKFB3. This study offers new insights into the roles of Klotho in regulating energy metabolism and the redox state in the brain.

Pregnancy-induced physiological hypertrophic preconditioning attenuates pathological myocardial hypertrophy by activation of FoxO3a.

Previous studies show a woman's pregnancy is correlated with post-reproductive longevity, and nulliparity is associated with higher risk of incident heart failure, suggesting pregnancy likely exerts a cardioprotection. We previously reported a cardioprotective phenomenon termed myocardial hypertrophic preconditioning, but it is unknown whether pregnancy-induced physiological hypertrophic preconditioning (PHP) can also protect the heart against subsequent pathological hypertrophic stress. We aimed to clarify the phenomenon of PHP and its mechanisms. The pluripara mice whose pregnancy-induced physiological hypertrophy regressed and the nulliparous mice underwent angiotensin II (Ang II) infusion or transverse aortic constriction (TAC). Echocardiography, invasive left ventricular hemodynamic measurement and histological analysis were used to evaluate cardiac remodeling and function. Silencing or overexpression of Foxo3 by adeno-associated virus was used to investigate the role of FoxO3a involved in the antihypertrophic effect. Compared with nulliparous mice, pathological cardiac hypertrophy induced by Ang II infusion, or TAC was significantly attenuated and heart failure induced by TAC was markedly improved in mice with PHP. Activation of FoxO3a was significantly enhanced in the hearts of postpartum mice. FoxO3a inhibited myocardial hypertrophy by suppressing signaling pathway of phosphorylated glycogen synthase kinase-3β (p-GSK3β)/β-catenin/Cyclin D1. Silencing or overexpression of Foxo3 attenuated or enhanced the anti-hypertrophic effect of PHP in mice with pathological stimulation. Our findings demonstrate that PHP confers resistance to subsequent hypertrophic stress and slows progression to heart failure through activation of FoxO3a/GSK3β pathway.