Genetic Variations in AMPK, FOXO3A, and POMC Increase the Risk of Extreme Obesity.

Objective: Genetic variability significantly impacts metabolism, weight gain, and feeding behaviors, predisposing individuals to obesity. This study explored how variations in key genes related to obesity-FOXO3A (forkhead box O3), AMPK (protein kinase AMP-activated), and POMC (proopiomelanocortin)-are associated with extreme obesity (EOB). Methods: We conducted a case-control study with 251 EOB patients and 212 healthy controls with a body mass index (BMI) of less than 25 kg/m2. We genotyped 10 single nucleotide variants (SNVs) using TaqMan-based assays. Results: Four SNVs-rs1536057 in FOXO3A, rs103685 in AMPK, rs934778, and rs6545975 in POMC-were associated with an increased risk of EOB. The strongest association was observed with rs934778 (POMC), which had a maximum odds ratio (OR) of 5.26 (95% CI: 2.86-9.09). While these genetic variations are closely linked to EOB, they do not affect serum glucose, triglycerides, HDL, LDL, BMI, or waist circumference. Conclusions: These findings indicate that factors beyond traditional metabolic pathways, potentially related to feeding behavior or hormonal regulation, may also link these genetic variations to obesity. Further research in a larger sample is essential to validate these findings and explore their potential to guide clinical interventions and public health strategies.

Lauric acid reduces apoptosis by inhibiting FOXO3a-signaling in deoxynivalenol-treated IPEC-J2 cells.

Deoxynivalenol (DON) is the most common mycotoxin contaminant of food or feed worldwide and causes disease in animals. Lauric acid (LA) is a medium-chain fatty acid useful for barrier functions such as antimicrobial activity in the intestine of monogastric animals. However, the molecular mechanisms by which lauric acid exerts its effects on the deoxynivalenol-exposed small intestine have not been studied. We used an intestinal porcine epithelial cell line (IPEC-J2) as an in vitro model to explore the molecular mechanism of lauric acid in alleviating deoxynivalenol-induced damage. We found that lauric acid reversed deoxynivalenol-induced reduction in cell viability. Our quantitative real-time polymerase chain reaction results indicated that lauric acid alleviated deoxynivalenol-induced apoptosis through Annexin-V. Additionally, immunofluorescence and Western blotting showed that lauric acid attenuated deoxynivalenol-induced forkhead box O3 (FOXO3a) translocation into the nucleus. These results suggest that lauric acid attenuates forkhead box O3 translocation in the small intestine damaged by deoxynivalenol, thereby reducing apoptosis. In conclusion, this study found that lauric acid alleviates deoxynivalenol-induced damage in intestinal porcine epithelial cell line through various molecular mechanisms.

Targeting STAT3, FOXO3a, and Pim-1 kinase by FDA-approved tyrosine kinase inhibitor-Radotinib: An in silico and in vitro approach.

Cancer, a multifactorial pathological condition, is primarily caused due to mutations in multiple genes. Hepatocellular carcinoma (HCC) is a form of primary liver cancer that is often diagnosed at the advanced stage. Current treatment strategies for advanced HCC involve systemic therapies which are often hindered due to the emergence of resistance and toxicity. Therefore, a multitarget approach might prove more effective in HCC treatment. The present study focuses on targeting signal transducer and activator of transcription 3 (STAT3), forkhead box class O3a (FOXO3a), and proviral integration site for Moloney murine leukemia virus-1 (Pim-1) kinase, using a Food and Drug Administration (FDA)-approved anticancer drug library. Two compounds, namely, radotinib and capmatinib, were identified as top compounds using molecular docking. Among the two compounds, radotinib exhibited significant binding values towards the targeted proteins and their heterodimers. Furthermore, in vitro experiments involving 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), live/dead, 4',6-diamidino-2-phenylindole, and clonogenic assays were performed to evaluate the effect of radotinib in human hepatoblastoma cell line/hepatocellular carcinoma cells. The gene expression data indicated reduced expression of FOXO3a and Pim-1, but no basal-level alteration of STAT3. The Western blot analysis assay showed that the phosphorylation level of STAT3 was significantly decreased upon radotinib treatment. Taken together, our findings suggest that radotinib, which is currently used in the treatment of chronic myeloid leukemia (CML), could be considered as a potential candidate for repurposing in the treatment of HCC.

Activation of AMPK/SIRT1/FOXO3a signaling by BMS-477118 (saxagliptin) mitigates chronic colitis in rats: uncovering new anti-inflammatory and antifibrotic roles.

Ulcerative colitis (UC) is a debilitating chronic disease marked by persistent inflammation and intestinal fibrosis. Despite the availability of various treatments, many patients fail to achieve long-term remission, underscoring a significant unmet therapeutic need. BMS-477118, a reversible inhibitor of dipeptidyl peptidase 4 (DPP4), has demonstrated anti-inflammatory properties in preclinical and clinical studies with minimal adverse effects compared to other antidiabetic agents. However, the potential benefits of BMS-477118 in chronic UC have not yet been explored. In this study, we aimed to investigate the effects of BMS-477118 in rats subjected to chronic dextran sodium sulfate (DSS) administration. Our findings indicate that BMS-477118 activates the interconnected positive feedback loop involving AMPK, SIRT1, and FOXO3a, improving histological appearance in injured rat colons. BMS-477118 also reduced fibrotic changes associated with the chronic nature of the animal model, alleviated macroscopic damage and disease severity, and improved the colon weight-to-length ratio. Additionally, BMS-477118 prevented DSS-induced weight loss and enhanced tight junction proteins. These effects, in conjunction with reduced oxidative stress and its potential anti-inflammatory, antiapoptotic, and autophagy-inducing properties, fostered prolonged survival in rats with chronic UC. To conclude, BMS-477118 has the potential to activate the AMPK/SIRT1/FOXO3a signaling pathway in inflamed colons. These results suggest that the AMPK/SIRT1/FOXO3a pathway could be a new therapeutic target for UC. Further research is mandatory to explore the therapeutic possibilities of this pathway. Additionally, continued studies on the therapeutic potential of BMS-477118 and other DPP4 inhibitors are promising for creating new treatments for various conditions, including UC in diabetic patients.

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.

Astragaloside IV Inhibits the Pyroptosis in the Acute Kidney Injury through Targeting the SIRT1/FOXO3a Axis.

Acute kidney injury (AKI) is a commonly encountered critical condition in clinical settings, often resulting from sepsis, infections or ischemia. Astragaloside IV (AS-IV) is the primary active component of Astragalus. The functions of Astragalus are mainly related to AS-IV, showing remarkable therapeutic effects in anti-inflammatory, antioxidant, immune-enhancing, and anti-tumor aspects. This study aimed to explore the role of AS-IV in AKI development. Lipopolysaccharide (LPS) was used to stimulate the HK-2 cells and rats to establish the AKI model in vivo and in vitro. After AS-IV treatment, the cell viability, pyroptosis rate, lactate dehydrogenase (LDH) activity, interleukin (IL)-18 and IL-1ß contents, and cleaved-caspase-1, GSDMD-N, SIRT, FOXO3a protein levels were detected. Caspase-1 levels were analyzed by immunofluorescence staining. Additionallly, the acetylation levels of FOXO3a were detected by immunoprecipitation and Western blot assays. AS-IV treatment promoted the cell viability, and inhibited the pyroptosis, LDH activity, caspase-1 levels in the LPS stimulated HK-2 cells. AS-IV treatment decreased the IL-18 and IL-1ß contents, cleaved-caspase-1 and GSDMD-N protein levels in both LPS stimulated HK-2 cells and rats. Furthermore, after EX527 treatment, a Sirtuin 1 (SIRT1) inhibitor, the role of AS-IV in the LPS stimulated HK-2 cells were reversed. AS-IV treatment increased the protein levels and decreased the acetylation levels of FOXO3a, which was reversed after EX527 treatment. Co-immunoprecipitation (CO-IP) assay and immunofluorescence staining confirmed that SIRT1 interacted with FOXO3a. In conclusion, this research demonstrated that AS-IV treatment inhibited the pyroptosis occurrence in LPS stimulated HK-2 cells and rats. This may be related to the SIRT1 mediated deacetylation of FOXO3a.

Micellar curcumol for maintenance therapy of ovarian cancer by activating the FOXO3a.

Maintenance therapy (MT) for ovarian cancer (OC) is crucial for preventing disease relapse. Curcumol shows effective anti-OC ability and low-toxicity to the normal ovarian epithelial cells, however, its bioavailability is low. Herein, micellar loaded curcumol (MC) was prepared and the anti-tumor ability of MC were performed on OC cells. The results indicated that the IC50 values of MC in two kinds of OC cells were 37.69 ± 2.43 and 28.54 ± 1.58 µg/mL, respectively. Mechanistically, curcumol could interact with the AKTThr308 site, inhibiting the phosphorylation of FOXO3a, which promoted FOXO3a nuclear locating and recruited it to the PERK promoter, activating the ERS induced apoptosis pathway. Moreover, MC inhibited the growth of SKOV3 cells on tumor-bearing nude mice and the DiR-labeled MC could quickly accumulate in the tumor region. MC provides great feasibility to achieve efficient MT for OC based on the nanoplatforms of active ingredients from natural products.

53BP1 regulates the self-renewal ability of neural stem/progenitor cells through modulating mitochondrial homeostasis.

The regulation of intracellular reactive oxygen species (ROS) levels is important for maintaining the self-renewal ability of neural stem/progenitor cells (NSCs). In this study, we demonstrate that 53BP1, a DNA damage response factor known to facilitate the repair of DNA double-strand breaks, supports the maintenance of NSC stemness. ReNcell VM human NSCs with depleted 53BP1 exhibited reduced self-renewal ability compared with control NSCs, as revealed by a decrease in neurosphere size and an increase in differentiation into neural or glial cells within an NSC culture. Furthermore, 53BP1 depletion elevated cellular ROS levels, accompanied by mitochondrial abnormalities. The reduced self-renewal ability and elevated ROS levels in 53BP1-deficient NSCs were restored with the treatment of a radical scavenger, N-acetyl-l-cysteine. In addition, we investigated the functional relationship in the NSC self-renewal ability between 53BP1 and ataxia-telangiectasia mutated (ATM) or forkhead box O3a (FOXO3a), factors required for mitochondrial homeostasis, and the maintenance of NSC stemness. We found that ATM inhibition or FOXO3a deficiency, in addition to 53BP1 deficiency, did not induce further NSC stemness impairment. Collectively, our findings show that 53BP1, by cooperatively functioning with ATM and FOXO3a, supports the maintenance of NSC stemness by modulating mitochondrial homeostasis.

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.

Resveratrol enhances the protective effects of calcium supplements on spinal cord injury-induced osteoporosis by targeting the SIRT1/FOXO3a pathway.

Spinal cord injury (SCI) often leads to osteoporosis due to factors like immobilization and hormonal imbalances. Calcium supplements are prescribed to help maintain bone health, but their efficacy may be limited. This study investigated whether resveratrol (RSV), a polyphenolic compound, could enhance the protective effects of calcium supplements on SCI-induced osteoporosis via the SIRT1/FOXO3a pathway, which regulates bone metabolism. Surgical cord transection induced SCI at the T9 vertebral level. An SCI mouse model was used with four groups: sham, SCI, SCI + 2% calcium, and SCI + calcium + RSV (20 mg/kg body weight). ||||||||||||||||||Biomechanical testing, gene expression, and Western blots were performed. Resveratrol and calcium supplementation synergistically preserved bone mass, microarchitecture, strength, and fracture resistance compared to calcium alone after SCI. This was accompanied by upregulated osteoblast markers, downregulated osteoclast markers, and increased SIRT1/FOXO3a expression and activation. The results suggest resveratrol enhances calcium's bone-protective effects in SCI-induced osteoporosis by modulating the SIRT1/FOXO3a pathway and osteoblast/osteoclast activities. Combining resveratrol with calcium supplementation may be a promising therapeutic approach for managing SCI-induced osteoporosis.

Ethanol enhances selenoprotein P expression via ERK-FoxO3a axis in HepG2 cells.

Drinking alcohol is considered one of the risk factors for development of diabetes mellitus. Recently, it was reported that selenoprotein P levels in blood are increased by ethanol intake. However, the mechanism by which ethanol increases selenoprotein P has not been elucidated. The expression of selenoprotein P protein and its mRNA were increased in a concentration- and time-dependent manner when human liver-derived HepG2 cells were treated with ethanol. Levels of AMPK and JNK proteins, which have been known to regulate selenoprotein P transcription, were unchanged by ethanol treatment. However, the amount of nuclear FoxO3a, a transcription factor of SeP, was increased. This was associated with dephosphorylation of ERK1 but not ERK2. It was found that ERK1 was dephosphorylated by activation of dual-specific phosphatase 5 and dual-specific phosphatase 6. However, the phosphorylation of MEK by ERK phosphokinase was not affected by ethanol treatment. These results suggest that the ethanol-induced increase in SeP levels occurs by enhanced transcription of SeP mRNA via the DUSP5/6-ERK1-FoxO3a pathway.

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.

Photobiomodulation Using 830 nm Lighting-Emitting Diode Inhibits Melanogenesis via FOXO3a in Human Melanocyte.

Photobiomodulation (PBM) using 830 nm light-emitting diode (LED) benefits tissue regeneration, wound healing and neural stimulation. However, there is not much exploration of its effect on melanocytes and ex vivo skin model. This study aims to investigate the mechanism behind the anti-melanogenic activity of 830 nm LED and provides evidence for its activity in human ex vivo skin model. Our results showed that 830 nm LED at fluences ranging from 5 to 20 J/cm2 inhibited melanosome maturation and reduced melanin content, tyrosinase activity and melanogenesis-related proteins. 830 nm LED inhibited the phosphorylation of AKT and its downstream FOXO3a, leading to nuclear translocation of FOXO3a. Furthermore, FOXO3a knockdown and AKT activator like SC79 could reverse the melanogenesis inhibition phenotype induced by 830 nm LED. In human ex vivo skin model, Fontana-Masson staining revealed a decrease in epidermal basal pigmentation after 830 nm LED irradiation. Taken together, 830 nm LED demonstrated the anti-melanogenic activity via FOXO3a.

Sodium Selenite Induces Autophagy and Apoptosis in Cervical Cancer Cells via Mitochondrial ROS-Activated AMPK/mTOR/FOXO3a Pathway.

Selenium (Se) is an essential trace element known for its significant role in maintaining human health and mitigating disease progression. Selenium and its compounds exhibit high selective cytotoxicity against tumor cells. However, their anti-cervical cancer (CC) effects and underlying mechanisms have not been fully explored. This study found that sodium selenite (SS) inhibits the viability of HeLa and SiHa cells in a dose- and time-dependent manner. Intraperitoneal injection of 3 and 6 mg/kg SS for 14 days in female nude mice significantly inhibited the growth of HeLa cell xenografts without evident hepatotoxicity or nephrotoxicity. RNA sequencing results indicated that the AMP-activated protein kinase (AMPK), Forkhead box protein O (FOXO), and apoptosis signaling pathways are key regulatory pathways in SS's anti-CC effects, and SS's inhibition of HeLa cell proliferation may be related to autophagy and ROS-induced apoptosis. Further research has revealed that SS induces cell autophagy and apoptosis through the AMPK/mTOR/FOXO3a pathway, characterized by the upregulation of p-AMPK/AMPK, FOXO3a, LC3-II, cleaved-caspase3, and cleaved-PARP and the downregulation of p-mTOR/mTOR and p62. Additionally, SS impaired mitochondrial function, including decreased mitochondrial membrane potential, mitochondrial Ca2+ overload, and accumulation of mitochondrial reactive oxygen species (mtROS). Pretreatment with Mitoquinone mesylate (Mito Q) and compound C partially reversed SS-induced apoptosis, autophagy, and proliferation inhibition. Pretreatment with 3-methyladenine (3-MA) enhances SS-induced apoptosis and proliferation inhibition in HeLa cells but reverses these effects in SiHa cells. In summary, SS induces apoptosis, autophagy, and proliferation inhibition in HeLa and SiHa cells through the activation of the AMPK/mTOR/FOXO3a signaling pathway via mtROS. Autophagy activation may be a major risk factor for SS-induced apoptosis in SiHa cells but can protect HeLa cells from SS-induced apoptosis. These findings provide new evidence for understanding the molecular mechanisms underlying SS in potential new drug development for CC.

Nobiletin restores HFD-induced enteric nerve injury by regulating enteric glial activation and the GDNF/AKT/FOXO3a/P21 pathway.

BACKGROUND: To explore whether nobiletin has a protective effect on high-fat diet (HFD)-induced enteric nerve injury and its underlying mechanism. METHODS: An obesity model was induced by a HFD. Nobiletin (100 mg/kg and 200 mg/kg) and vehicle were administered by gastric gavage for 4 weeks. Lee's index, body weight, OGTT and intestinal propulsion assays were performed before sacrifice. After sampling, lipids were detected using Bodipy 493/503; lipid peroxidation was detected using MDA and SOD kits and the expression of PGP 9.5, Trem2, GFAP, ß-tubulin 3, Bax, Bcl2, Nestin, P75 NTR, SOX10 and EDU was detected using immunofluorescence. The GDNF, p-AKT, AKT, p-FOXO3a, FOXO3a and P21 proteins were detected using western blotting. The relative mRNA expression levels of NOS2 were detected via qPCR. Primary enteric neural stem cells (ENSCs) were cultured. After ENSCs were treated with palmitic acid (PA) and nobiletin, CCK-8 and caspase-3/7 activity assays were performed to evaluate proliferation and apoptosis. RESULTS: HFD consumption caused colon lipid accumulation and peroxidation, induced enteric nerve damage and caused intestinal motor dysfunction. However, nobiletin reduced lipid accumulation and peroxidation in the colon; promoted Trem2, ß-tubulin 3, Nestin, P75NTR, SOX10 and Bcl2 expression; inhibited Bax and GFAP expression; reduced NOS2 mRNA transcription; and regulated the GDNF/AKT/FOXO3a/P21 pathway. Nobiletin also promoted PA-induced impairment of ENSCs. CONCLUSIONS: Nobiletin restored HFD-induced enteric nerve injury, which may be associated with inhibiting enteric nerve apoptosis, promoting enteric nerve survival and regulating the GDNF/AKT/FOXO3a/P21 pathway.

Dihydromyricetin protects sevoflurane-induced mitochondrial dysfunction in HT22 hippocampal cells.

Sevoflurane (Sev) is a commonly used inhalation anaesthetic that has been shown to cause hippocampus dysfunction through multiple underlying molecular processes, including mitochondrial malfunction, oxidative stress and inflammation. Dihydromyricetin (DHM) is a 2,3-dihydroflavonoid with various biological properties, such as anti-inflammation and anti-oxidative stress. The purpose of this study was to investigate the effect of DHM on Sev-induced neuronal dysfunction. HT22 cells were incubated with 10, 20 and 30 µM of DHM for 24 h, and then stimulated with 4% Sev for 6 h. The effects and mechanism of DHM on inflammation, oxidative stress and mitochondrial dysfunction were explored in Sev-induced HT22 cells by Cell Counting Kit-8, flow cytometry, enzyme-linked immunosorbent assay, reverse transcription-quantitative polymerase chain reaction, colorimetric detections, detection of the level of reactive oxygen species (ROS), mitochondrial ROS and mitochondrial membrane potential (MMP), immunofluorescence and western blotting. Our results showed that DHM increased Sev-induced cell viability of HT22 cells. Pretreatment with DHM attenuated apoptosis, inflammation, oxidative stress and mitochondrial dysfunction in Sev-elicited HT22 cells by remedying the abnormality of the indicators involved in these progresses, including apoptosis rate, the cleaved-caspase 3 expression, as well as the level of tumour necrosis factor α, interleukin (IL)-1ß, IL-6, malondialdehyde, superoxide dismutase, catalase, ROS, mitochondrial ROS and MMP. Mechanically, pretreatment with DHM restored the Sev-induced the expression of SIRT1/FOXO3a pathway in HT22 cells. Blocking of SIRT1 counteracted the mitigatory effect of DHM on apoptosis, inflammation, oxidative stress and mitochondrial dysfunction in Sev-elicited HT22 cells. Collectively, pretreatment with DHM improved inflammation, oxidative stress and mitochondrial dysfunction via SIRT1/FOXO3a pathway in Sev-induced HT22 cells.

SIRT6 suppresses colon cancer growth by inducing apoptosis and autophagy through transcriptionally down-regulating Survivin.

SIRT6, an evolutionarily conserved histone deacetylase, has been identified as a novel direct downstream target of Akt/FoxO3a and a tumor suppressor in colon cancer in our previous research. Nevertheless, the precise mechanisms through which SIRT6 hinders tumor development remain unclear. To ascertain whether SIRT6 directly impacts Survivin transcription, a ChIP assay was conducted using an anti-SIRT6 antibody to isolate DNA. YM155 was synthesized to explore Survivin's role in mitochondrial apoptosis, autophagy and tumor progression. Our investigation into the regulation of Survivin involved real-time fluorescence imaging in living cells, real-time PCR, immunohistochemistry, flow cytometry, and xenograft mouse assays. In this current study, we delved into the role of SIRT6 in colon cancer and established that activated SIRT6 triggers mitochondrial apoptosis by reducing Survivin expression. Subsequent examinations revealed that SIRT6 directly binds to the Survivin promoter, impeding its transcription. Notably, direct inhibition of Survivin significantly impeded colon cancer proliferation by inducing mitochondrial apoptosis and autophagy both in vitro and in vivo. More interestingly, Survivin inhibition reactivated the Akt/FoxO3a pathway and elevated SIRT6 levels, establishing a positive feedback loop. Our results identify Survivin as a novel downstream transcriptional target of SIRT6 that fosters tumor growth and holds promise as a prospective target for colon cancer therapy.

The role of Foxo3a in neuron-mediated cognitive impairment.

Cognitive impairment (COI) is a prevalent complication across a spectrum of brain disorders, underpinned by intricate mechanisms yet to be fully elucidated. Neurons, the principal cell population of the nervous system, orchestrate cognitive processes and govern cognitive balance. Extensive inquiry has spotlighted the involvement of Foxo3a in COI. The regulatory cascade of Foxo3a transactivation implicates multiple downstream signaling pathways encompassing mitochondrial function, oxidative stress, autophagy, and apoptosis, collectively affecting neuronal activity. Notably, the expression and activity profile of neuronal Foxo3a are subject to modulation via various modalities, including methylation of promoter, phosphorylation and acetylation of protein. Furthermore, upstream pathways such as PI3K/AKT, the SIRT family, and diverse micro-RNAs intricately interface with Foxo3a, engendering alterations in neuronal function. Through several downstream routes, Foxo3a regulates neuronal dynamics, thereby modulating the onset or amelioration of COI in Alzheimer's disease, stroke, ischemic brain injury, Parkinson's disease, and traumatic brain injury. Foxo3a is a potential therapeutic cognitive target, and clinical drugs or multiple small molecules have been preliminarily shown to have cognitive-enhancing effects that indirectly affect Foxo3a. Particularly noteworthy are multiple randomized, controlled, placebo clinical trials illustrating the significant cognitive enhancement achievable through autophagy modulation. Here, we discussed the role of Foxo3a in neuron-mediated COI and common cognitively impaired diseases.

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.

CircPGM5 regulates Foxo3a phosphorylation via MiR-21-5p/MAPK10 axis to inhibit bladder cancer progression.

Bladder cancer (BC) is one of the most prevalent malignant tumors worldwide, and the incidence is especially higher in males. Extensive evidence has demonstrated the pivotal role of circular RNAs (circRNAs) in BC progression. However, the exact regulatory mechanism of circRNAs in BC remains incompletely elucidated and warrants further exploration. This study screened a novel circRNA-circPGM5 from thousands of circRNAs by high-throughput sequencing. We found that circPGM5, originating from the PGM5 gene, was significantly lower expressed in BC tissues. Quantitative real-time PCR (qRT-PCR) verified that circPGM5 showed relatively low expression in 50 pairs of BC tissues and EJ and T24 cells. Notably, circPGM5 expression was correlated with stage, grade, and lymphatic metastasis of BC. Through RNA-FISH assay, we confirmed that circPGM5 predominantly localized in the cytoplasm. Functionally, overexpression of circPGM5 inhibited the proliferation, migration, and invasion of BC cells in vitro. Remarkably, circPGM5 demonstrated markedly significant tumor growth and metastasis suppression in vivo. Mechanistically, we discovered that circPGM5 upregulated the mitogen-activated protein kinase 10 (MAPK10) expression by influencing the oncogenic miR-21-5p activity through miR-21-5p absorption. This modulation of MAPK10 impacted the phosphorylation of the tumor suppressor Foxo3a in BC. In conclusion, our findings uncovered the tumor-suppressing role of circPGM5 in BC via the miR-21-5p/MAPK10/Foxo3a axis.