Akt Phosphorylation Research Articles

S-RBD-modified and miR-486-5p-engineered exosomes derived from mesenchymal stem cells suppress ferroptosis and alleviate radiation-induced lung injury and long-term pulmonary fibrosis

BackgroundRadiation-induced lung injury (RILI) is associated with alveolar epithelial cell death and secondary fibrosis in injured lung. Mesenchymal stem cell (MSC)-derived exosomes have regenerative effect against lung injury and the potential to intervene of RILI. However, their intervention efficacy is limited because they lack lung targeting characters and do not carry sufficient specific effectors. SARS-CoV-2 spike glycoprotein (SARS-CoV-2-S-RBD) binds angiotensin-converting enzyme 2 (ACE2) receptor and mediates interaction with host cells. MiR-486-5p is a multifunctional miRNA with angiogenic and antifibrotic potential and acts as an effector in MSC-derived exosomes. Ferroptosis is a form of cell death associated with radiation injury, its roles and mechanisms in RILI remain unclear. In this study, we developed an engineered MSC-derived exosomes with SARS-CoV-2-S-RBD- and miR-486-5p- modification and investigated their intervention effects on RIPF and action mechanisms via suppression of epithelial cell ferroptosis.ResultsAdenovirus-mediated gene modification led to miR-486-5p overexpression in human umbilical cord MSC exosomes (p < 0.05), thereby constructing miR-486-5p engineered MSC exosomes (miR-486-MSC-Exo). MiR-486-MSC-Exo promoted the proliferation and migration of irradiated mouse lung epithelial (MLE-12) cells in vitro and inhibited RILI in vivo (all p < 0.05). MiR-486-MSC-Exo suppressed ferroptosis in MLE-12 cells, and an in vitro assay revealed that the expression of fibrosis-related genes is up-regulated following ferroptosis (both p < 0.05). MiR-486-MSC-Exo reversed the up-regulated expression of fibrosis-related genes induced by TGF-β1 in vitro and improved pathological fibrosis in RIPF mice in vivo (all p < 0.05). SARS-CoV-2-S-RBD-modified and miR-486-5p-engineered MSC exosomes (miR-486-RBD-MSC-Exo) were also constructed, and the distribution of DiR dye-labeled miR-486-RBD-MSC-Exo in hACE2CKI/CKI Sftpc-Cre+ mice demonstrated long-term retention in the lung (p < 0.05). MiR-486-RBD-MSC-Exo significantly improved the survival rate and pathological changes in hACE2CKI/CKI Sftpc-Cre+ RIPF mice (all p < 0.05). Furthermore, miR-486-MSC-Exo exerted anti-fibrotic effects via targeted SMAD2 inhibition and Akt phosphorylation activation (p < 0.05).ConclusionsEngineered MSC exosomes with SARS-CoV-2-S-RBD- and miR-486-5p-modification were developed. MiR-486-RBD-MSC-Exo suppressed ferroptosis and fibrosis of MLE-12 cells in vitro, and alleviated RILI and long-term RIPF in ACE2 humanized mice in vivo. MiR-486-MSC-Exo exerted anti-fibrotic effects via SMAD2 inhibition and Akt activation. This study provides a potential approach for RIPF intervention.Graphical

Veratridine, a plant-derived alkaloid, suppresses the hyperactive Rictor-mTORC2 pathway: a new targeted therapy for primary and metastatic colorectal cancer.

Despite considerable advances to improve colorectal cancer (CRC) survival over the last decade, therapeutic challenges remain due to the rapid metastatic dissemination of primary tumors and screening limitations. Meanwhile, the rise of CRC in younger adults (Early-onset CRC), commonly diagnosed with a metastatic form of the disease, shows the pressing need to develop more effective targeted therapies to decrease the high mortality rates associated with metastatic disease. Hyperactivation of the Rictor-mTORC2-AKT signaling pathway drives key metastatic players in diverse malignant tumors, including early- and late-onset colorectal cancer. Selective mTORC2 inhibitors are becoming a potential treatment strategy for CRC due to the therapeutic limitations of mTORC1 inhibitors. Veratridine (VTD), a lipid-soluble alkaloid extracted from Liliaceae plants, can transcriptionally increase UBXN2A, which induces 26S proteasomal degradation of the Rictor protein, a key member in the mTORC2 complex. Destabilization of Rictor protein by VTD decreases Akt phosphorylation on Ser 473 , which is responsible for metastatic signaling downstream of the mTORC2 pathway in diverse malignant tumors. VTD decreases the population of metastatic colon cancer stem cells and functions as an angiogenesis inhibitor. VTD effectively reduces the spheroid growth rate and restricts cell migration. Live cell migration and invasion assays alongside biomechanical-force-based experiments revealed that VTD suppresses colon cancer cell invasiveness and the ensuing risk of tumor metastasis. A CRC mouse model that mimics the natural stages of human sporadic CRC revealed that VTD treatment significantly decreases tumor growth in a UBXN2A-dependent manner. This study showed a novel mechanistic connection between a ubiquitin-like protein and mTORC2-dependent migration and invasion in CRC tumors. This study revealed the therapeutic benefit of selective inhibition of Rictor in CRC, particularly in tumors with a hyperactive Rictor-mTORC2 signaling pathway. Finally, this study opened a new platform for repurposing VTD, a supplemental anti-hypertension molecule, into an effective targeted therapy in CRC tumors.

Prolonged treatment of compactin, atorvastatin, lovastatin or simvastatin decreased glucose consumption and expressions of proteins for glucose metabolism and insulin signaling in L6 skeletal muscle cells

Statins inhibit mevalonate synthesis and successfully lower plasma cholesterol levels and decrease the risk of cardiovascular diseases in humans, but also lead to myalgia in some patients. We hypothesize that statins may modulate glucose metabolism and insulin signaling in the skeletal muscle cells during and after differentiation, and in turn lead to side effects. Here, differentiating and differentiated L6 muscle cells were treated with 1 μM of different class of statins (compactin, pravastatin, atorvastatin, lovastatin and simvastatin) with or without insulin or mevalonate for extended periods of time. The glucose consumption and expression levels of proteins for glucose metabolism and insulin receptor (IR)/Akt signaling were determined. The prolonged statin treatments (except pravastatin) decreased glucose consumption in L6 skeletal muscle cells. In differentiating L6 cells, compactin, lovastatin or simvastatin decreased the expression levels of proteins involved in glucose metabolism and insulin signaling, including glucose transporter 4 (GLUT4), pyruvate dehydrogenase (PDH), glycogen synthase (GS), glycogen synthase kinase 3β (GSK3β) and insulin receptor β subunit (IRβ). In differentiated L6 cells, long-term treatment of compactin or simvastatin also decreased levels of proteins in glucose metabolism and IR/Akt signaling, including GLUT4, GSK3β, IRβ and PI3K p110α. Insulin treatment restored statin-mediated impairments in L6 cells. The insulin-mediated phosphorylation of Akt Ser473 was attenuated in differentiating and differentiated L6 cells in the presence of atorvastatin (differentiated only), compactin, lovastatin or simvastatin. In addition, mevalonate supplementation reversed the statin-mediated impairments in differentiated and differentiating L6 cells. Statin affected glucose usage and insulin signaling by inhibiting mevalonate synthesis in L6 cells. Our results provides a possible mechanism of adverse effects of statins in skeletal muscle and calls for cautious use of the medication in patients with impaired insulin sensitivity and glucose metabolism.

Activation of platelet-derived growth factor receptors regulate connective tissue growth factor protein levels via the AKT pathway in malignant mesothelioma cells.

The incidence of malignant mesothelioma (MM), a disease linked to refractory asbestos exposure, continues to increase globally, and remains largely resistant to various treatments. Our previous studies have identified a strong correlation between connective tissue growth factor (CTGF) protein expression and MM malignancy, underscoring the importance of understanding CTGF regulation in MM cells. In this study, we demonstrate for the first time that stimulation with platelet-derived growth factor receptor (PDGFR) ligand, PDGF-BB, increases CTGF protein expression levels without affecting CTGF mRNA levels. Inhibition of PDGFR resulted in a reduction of CTGF protein expression, indicating that PDGFR activation is essential in regulating CTGF protein expression in MM cells. PDGF-BB also activated the protein kinase B (AKT) pathway, and inhibition of AKT phosphorylation abolished the PDGFR-induced CTGF protein expression, suggesting that PDGFR acts upstream of CTGF via the AKT pathway. This reinforces the role of CTGF protein as a key regulator of MM malignancy. Additionally, PDGFR activation led to the phosphorylation of mTOR and 4E-BP1, critical regulators of protein synthesis downstream of AKT, suggesting that PDGFR controls CTGF protein expression through the regulation of CTGF mRNA translation.

FoxO1/Rictor axis induces a non-genetic adaptation to Ibrutinib via Akt activation in chronic lymphocytic leukemia.

BTK inhibitor therapy induces peripheral blood lymphocytosis in chronic lymphocytic leukemia (CLL) lasting for several months. It remains unclear whether non-genetic adaptation mechanisms exist, allowing CLL cells' survival during BTK inhibitor-induced lymphocytosis and/or playing a role in therapy resistance. We show that in approximately 70 % of CLL cases, ibrutinib treatment in vivo increases Akt activity above pre-therapy levels within several weeks, leading to compensatory CLL cell survival and a more prominent lymphocytosis on therapy. Ibrutinib-induced Akt phosphorylation (pAktS473) is caused by the upregulation of FoxO1 transcription factor, which induces expression of Rictor, an assembly protein for mTORC2 protein complex that directly phosphorylates Akt at serine 473 (S473). Knock-out or inhibition of FoxO1 or Rictor led to a dramatic decrease in Akt phosphorylation and growth disadvantage for malignant B cells in the presence of ibrutinib (or PI3K inhibitor idelalisib) in vitro and in vivo. FoxO1/Rictor/pAktS473 axis represents an early non-genetic adaptation to BCR inhibitor therapy not requiring PI3Kδ or BTK kinase activity. We further demonstrate that FoxO1 can be targeted therapeutically, and its inhibition induces CLL cells' apoptosis alone or in combination with BTK inhibitors (ibrutinib, acalabrutinib, pirtobrutinib) and blocks their proliferation triggered by T-cell factors (CD40L, IL-4, and IL-21).

Transcriptome analysis reveals a role of FOXO3 in antileukemia/lymphoma properties of panduratin A

Boesenbergia rotunda, commonly known as fingerroot, is a medicinal and culinary plant native to the Indochina Peninsula. We found that panduratin A (Pan-A), one of the compounds present in the rhizome extract of fingerroot, inhibited cell proliferation, induced apoptosis, and promoted cell cycle arrest at G0/G1 phase in multiple hematologic malignant cell lines including leukemia and lymphoma lines. Pan-A inhibited these activities in leukemia and lymphoma cells in a concentration-dependent manner. High-throughput transcriptome analysis indicated that Pan-A is involved in the cell cycle, cellular senescence, apoptosis, and multiple canonical signaling pathways in lymphoma cells. The Forkhead box O (FOXO) transcription factor family was identified as a potential target of Pan-A. Western blot showed elevated caspase 7 and cPARP/PARP in the B-cell lymphoma cells after treatment with Pan-A. The inhibitory effects were accompanied by stimulation of Akt signaling and phosphorylation of FOXO3. Immunohistochemistry of tissues from patients with B-cell lymphoma revealed detectable levels of FOXO3 protein specifically in neoplastic B cells. Overall, our results highlight FOXO3 as a player underlying antileukemia/lymphoma effects of Pan-A.

LncRNA MAGI2-AS3 enhances cisplatin sensitivity of non-small cell lung cancer cells by regulating the miR-1269a/PTEN/AKT pathway

To investigate the mechanism mediating the regulatory effect of lncRNA MAGI2-AS3 on cisplatin (DDP) resistance in non-small cell lung cancer (NSCLC). MAGI2-AS3 and miR-1269a expression levels were detected by qRT-PCR in DDP-sensitive lung cancer cell lines (A549 and H1299) and their resistant counterparts (A549/DDP and H1299/DDP). In A549 and H1299 cells with MAGI2-AS3 silencing and A549/DDP and H1299/DDP cells overexpressing MAGI2-AS3, the effects of 20 μmol/L DDP on cell viability and apoptosis were examined with CCK-8 assay, colony formation assay, flow cytometry and Western blotting, and the changes in epithelial-mesenchymal transition (EMT) were assessed with wound healing and Transwell assays. The interaction between MAGI2-AS3, miR-1269a and PTEN was predicted using GEPIA, StarBase and miRDB and verified with luciferase reporter gene assay and radioimmunoprecipitation (RIP) assay. A miR-1269a mimic and pcDNA3.1-PTEN plasmid were used to perform the rescue assay. MAGI2-AS3 expression was significantly downregulated in lung cancer tissues (P < 0.05) in association with a poor prognosis (P < 0.05). In the two DDP-resistant lung cancer cell lines, MAGI2-AS3 expression was significantly lowered as compared with the sensitive cells. Silencing MAGI2-AS3 significantly enhanced cell viability and promoted EMT of A549 and H1299 cells irrespective of DDP treatment, and also decreased DDP-induced apoptosis of the cells. In A549/DDP and H1299/DDP cells, MAGI2-AS3 overexpression strongly repressed cell viability and EMT irrespective of DDP treatment and promoted DDP-induced cell apoptosis. Luciferase reporter gene and RIP assays confirmed the binding of MAGI2-AS3 with miR-1269a and the binding of miR-1269a with 3 '-UTR domain of PTEN. The rescue assay demonstrated that MAGI2-AS3 acted as a sponge for miR-1269a to promote PTEN expression and downregulate AKT phosphorylation, thus inhibiting EMT and promoting DDP-induced apoptosis of A549/DDP cells. MAGI2-AS3 enhances DDP sensitivity of NSCLC by targeted regulation of the miR-1269a/PTEN/AKT signaling axis.

Gastrodin alleviates microglia-mediated inflammatory responses in neonatal mice with hypoxic-ischemic brain damage by regulating CCR5/AKT signaling

To investigate the mechanism behind the protective effects of gastrodin against microglia-mediated inflammatory responses following hypoxic-ischemic brain damage (HIBD) in neonatal mice. Thirty-six 10-day-old C57BL/6J mice were randomized into sham-operated group, HIBD (induced by ligation of the left common carotid artery followed by hypoxia for 40 min) group, and HIBD with gastrodin treatment groups (n=12). In gastrodin treatment group, 100 mg/kg gastrodin was injected intraperitoneally 1 h before and at 2 and 12 h after hypoxia. After the treatments, the expressions of CCR5, AKT, p-AKT, and TNF-α and the co-expression of IBA1 and CCR5 in the corpus callosum of the mice were detected with Western blotting and immunofluorescence double staining. In a BV2 microglial cell model of oxygen-glucose deprivation (OGD), the effects of pretreatment with gastrodin and Maraviroc (an CCR5 antagonist) on protein expressions of CCR5, AKT, p-AKT, TNF-α and IL-1β were evaluated using Western blotting and immunofluorescence double staining. The neonatal mice with HIBD showed significantly increased expressions of CCR5 and TNF-α with lowered p-AKT expression in the brain tissues, and GAS treatment obviously reversed these changes. HIBD also significantly increased the co-expression of IBA1 and CCR5 in the corpus callosum of the mice, which was obviously lowered by gastrodin treatment. In BV2 cells, OGD significantly increased the expressions of CCR5, TNF-α, and IL-1β and decreased the expression of p-AKT, and these changes were inhibited by treatment with gastrodin, Maraviroc or their combination; the inhibitory effect of the combined treatment did not differ significantly from that of gastrodin or Maraviroc alone. Gastrodin can produce neuroprotective effects in neonatal mice with HIBD by inhibiting inflammatory cytokine production and activate AKT phosphorylation via inhibiting CCR5.

Effects of phospholipase D1-inhibitory peptide on the growth and metastasis of gastric cancer cells

Phospholipase D1 (PLD1) contributes to cancer development and progression through its effects on cell proliferation, survival, invasion, metastasis, angiogenesis, drug resistance, and modulation of the tumor microenvironment. Its central role in these processes makes it a promising target for novel cancer treatments aimed at inhibiting its activity and disrupting the signaling pathways it regulates. In this study, we aimed to investigate the effect of PLD1 inhibition on gastric cancer cell growth using a novel peptide inhibitor, TAT-TVTSP. PLD1, which plays a role in cancer progression, catalyzes the conversion of phosphatidylcholine into choline and phosphatidic acid through hydrolysis. To effectively target PLD1 in cells, we engineered TAT-TVTSP by fusing a PLD1-inhibitory peptide (TVTSP) with a cell-penetrating peptide (TAT). We observed that TAT-TVTSP effectively inhibited PLD1 activity in AGS gastric cancer cells. Moreover, TAT-TVTSP significantly inhibited the mammalian target of the rapamycin signaling pathway, including the phosphorylation of key downstream targets such as S6K1, AKT, S473, glycogen synthase kinase-3b, and forkhead box O1. TAT-TVTSP did not induce cell death, but it triggered cell cycle arrest by activating p21 and p27 via AKT phosphorylation. Functional assays revealed that TAT-TVTSP significantly impaired the colony-forming ability of AGS cells, thus inhibiting cell proliferation. Transwell and wound-healing assays revealed that this peptide disrupted the cellular behaviors critical to cancer progression, such as migration and invasion. In vivo, TAT-TVTSP significantly reduced tumor growth in the xenograft model of gastric cancer without any toxicity. Overall, our results suggest that TAT-TVTSP is a novel therapeutic agent for PLD1-mediated cancers.

Mangiferin Represses Inflammation in Macrophages Under a Hyperglycemic Environment Through Nrf2 Signaling.

Inflammation in macrophages is exacerbated under hyperglycemic conditions, contributing to chronic inflammation and impaired wound healing in diabetes. This study investigates the potential of mangiferin, a natural polyphenol, to alleviate this inflammatory response by targeting a redox-sensitive transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2). Mangiferin, a known Nrf2 activator, was evaluated for its ability to counteract the hyperglycemia-induced inhibition of Nrf2 and enhance antioxidant defenses. The protective effects of mangiferin on macrophages in a hyperglycemic environment were assessed by examining the expression of Nrf2, NF-κB, NLRP3, HO-1, CAT, COX-2, IL-6, and IL-10 through gene and protein expression analyses using qPCR and immunoblotting, respectively. The mangiferin-mediated nuclear translocation of Nrf2 was evidenced, leading to a robust antioxidant response in macrophages exposed to a hyperglycemic microenvironment. This activation suppressed NF-κB signaling, reducing the expression of pro-inflammatory mediators such as COX-2 and IL-6. Additionally, mangiferin decreased NLRP3 inflammasome activation and reactive oxygen species accumulation in hyperglycemia exposed macrophages. Our findings revealed that mangiferin alleviated hyperglycemia-induced reductions in AKT phosphorylation, highlighting its potential role in modulating key signaling pathways. Furthermore, mangiferin significantly enhanced the invasiveness and migration of macrophages in a hyperglycemic environment, indicating its potential to improve wound healing. In conclusion, this study suggests that mangiferin may offer a promising therapeutic approach for managing inflammation and promoting wound healing in diabetic patients by regulating Nrf2 activity in hyperglycemia-induced macrophages.

Circulating extracellular vesicle-carried PTP1B and PP2A phosphatases as regulators of insulin resistance.

Metabolic disorders associated with abdominal obesity, dyslipidaemia, arterial hypertension and hyperglycaemia are risk factors for the development of insulin resistance. Extracellular vesicles (EVs) may play an important role in the regulation of metabolic signalling pathways in insulin resistance and associated complications. Circulating large EVs (lEVs) and small EVs (sEVs) from individuals with (IR group) and without insulin resistance (n-IR group) were isolated and characterised. lEVs and sEVs were administered by i.v. injection to mice and systemic, adipose tissue and liver insulin signalling were analysed. The role of phosphatases was analysed in target tissues and cells. Injection of lEVs and sEVs from IR participants impaired systemic, adipose tissue and liver insulin signalling in mice, while EVs from n-IR participants had no effect. Moreover, lEVs and sEVs from IR participants brought about a twofold increase in adipocyte size and adipogenic gene expression. EVs from IR participants expressed two types of phosphatases, phosphotyrosine 1 phosphatase (PTP1B) and protein phosphatase 2 (PP2A), IR lEVs being enriched with the active form of PTP1B while IR sEVs mainly carried active PP2A. Blockade of PTP1B activity in IR lEVs fully restored IRS1 and Akt phosphorylation in adipocytes and blunted insulin-induced Akt phosphorylation by inhibition of the macrophage secretome in hepatocytes. Conversely, blockade of PP2A activity in IR sEVs completely prevented insulin resistance in adipocytes and hepatocytes. These data demonstrate that inhibition of phosphatases carried by EVs from IR participants rescues insulin signalling in adipocytes and hepatocytes and point towards PTP1B and PP2A carried by IR EVs as being novel potential therapeutic targets against insulin resistance in adipose tissue and liver and the development of obesity.

Dendrobium huoshanense stem polysaccharide exhibits gastroprotective effect via regulating PI3K/AKT, NF-κB and Nrf-2 signaling in high-salt diet-induced gastritis mice

Prolonged consumption of high-salt diet (HSD) is implicated in the development of gastritis. This research intends to explore the protective potential of Dendrobium huoshanense stem polysaccharide (cDHPS) on gastritis in high-salt diet mice. cDHPS effectively alleviated the symptoms of HSD-induced gastritis, which were demonstrated by the reversed weight loss, gastric mucosal swelling, gastric mucus depletion, tight junction (TJ) disruption, and microvascular endothelial cell necrosis. Notably, cDHPS inhibited HSD-induced gastric inflammation, which was evidenced by the remodeled balance of Th17/Treg cells, along with the decreased level of IL-17 and the increased level of IL-10. Simultaneously, the oxidative stress induced by HSD was also improved with cDHPS treatment. Western blot analysis revealed that cDHPS markedly upregulated Nrf-2 expression while concurrently inhibiting the phosphorylation of P65, IκB, PI3K, AKT and FOXO-1 in the gastric tissues of HSD-induced gastritis mice. Collectively, these results indicate that cDHPS possesses protective potential against HSD-induced gastritis, which was attributable to the improvement of inflammatory and oxidative damage by modulating the PI3K/AKT and NF-κB/Nrf-2 signaling.

Polyphyllin VI Ameliorates Pulmonary Fibrosis by Suppressing the MAPK/ERK and PI3K/AKT Signaling Pathways via Upregulating DUSP6.

Pulmonary fibrosis (PF) is a lethal disease caused by inordinate repair of damaged lungs, for which limited strategies are available. Polyphyllin VI (PPVI), extracted and isolated from Paris polyphylla Smith var. chinensis (Franch.) Hara, has been regarded as an important traditional Chinese herbal medicine for the treatment of respiratory system diseases. This study evaluated effects of PPVI on PF and its underlying mechanism. Experimental procedure For evaluating the anti-PF effect of PPVI, we established an in vivo PF mouse model via intratracheal infusion of bleomycin (BLM) in mice and an in vitro PF model induced by TGF-β1 in NIH/3T3, HPF and A549, respectively. Subsequently, the mechanism of PPVI effects was further explored using RNA sequencing (RNA-Seq). The in vivo and in vitro results demonstrated that PPVI significantly inhibited inflammation, oxidative damage, and epithelial-mesenchymal transition. Furthermore, RNA sequencing indicated that PPVI ameliorated PF by modulating inflammation and oxidative stress responses. Furthermore, dual specificity phosphatase 6 (DUSP6), was the shared and most significant differentially expressed gene associated with inflammation and oxidative stress response after PPVI treatment. Mechanistically, silencing DUSP6 can eliminate the suppressive impact on PPVI for the activation of fibroblast and the phosphorylation of ERK and AKT. Summarily, our findings revealed the potential of PPVI in mitigating PF via upregulating DUSP6 and highlighted the regulatory function of DUSP6 in the pathogenesis of PF.

Distinct role of GRK3 in platelet activation by desensitization of G protein-coupled receptors.

Many platelet agonists mediate their cellular effects through G protein-coupled receptors (GPCRs) to induce platelet activation, and GPCR kinases (GRKs) have been demonstrated to have crucial roles in most GPCR functions in other cell types. Here, we investigated the functional role of GRK3 and the molecular basis for the regulation of GPCR desensitization by GRK3 in platelets. We used mice lacking GRK3 as well as β-arrestin2 which has been shown to be important in GPCR function in platelets. Platelet aggregation and dense granule secretion induced by 2-MeSADP, U46619, thrombin, and AYPGKF were significantly potentiated in both GRK3 -/- and β-arrestin2 -/- platelets compared to wild-type (WT) platelets, while non-GPCR agonist collagen-induced platelet aggregation and secretion were not affected. We have previously shown that GRK6 is not involved in the regulation of Gq-coupled 5HT2A and Gz-coupled a2A adrenergic receptors. Interestingly, in contrast to GRK6, platelet aggregation induced by co-stimulation of serotonin and epinephrine which activate 5-HT2A and a2A adrenergic receptors, respectively, was significantly potentiated in GRK3 -/- platelets, suggesting that GRK3 was involved in general GPCR regulation. In addition, platelet aggregation in response to the second challenge of ADP was restored in GRK3 -/- platelets whereas re-stimulation of the agonist failed to induce aggregation in WT platelets, confirming that GRK3 contributes to general GPCR desensitization. Finally, 2-MeSADP- and AYPGKF-induced AKT and ERK phosphorylation were significantly potentiated in GRK3 -/- platelets. GRK3 plays a crucial role in the regulation of platelet activation through general GPCR desensitization in platelets.

Circ_0001047 inhibits prostate cancer progression and enhances abiraterone sensitivity via miR-122-5p/FKBP5/PHLPP1/AKT axis in vitro

Prostate cancer (PCa), with high heterogeneity and poor prognosis, is one of the most common malignant tumors in men. Circular RNAs (circRNAs) have been identified in tumor progression and resistance to medication in numerous studies. However, the role of circ_0001047 in PCa is unclear. In this research, we found that circ_0001047 had low expression in PCa cells and tissues and was negatively correlated with testosterone secretion in vivo. Overexpression of circ_0001047 inhibited the proliferation, migration, invasion, and anti-apoptotic abilities of human PCa cells in vitro. Mechanistically, circ_0001047 promoted the expression of FKBP5 through sponge adsorption of miR-122-5p and then inhibited the proliferation, anti-apoptotic migration, and invasion abilities of PCa cells. In addition, overexpression of circ_0001047 enhanced the sensitivity of PCa cells to abiraterone by inhibiting AKT phosphorylation activation through upregulation of FKBP5/PHLPP1. This study revealed a novel mechanism by which circ_0001047 regulates PCa progression and treatment sensitivity via the miR-122-5p/FKBP5/PHLPP1/AKT axis. These findings deepen our comprehension of the molecular mechanisms in latent PCa progression and treatment resistance.Graphical

The role and mechanism of NRG1/ErbB4 in inducing the differentiation of induced pluripotent stem cells into cardiomyocytes

BackgroundWe aimed to investigate the effect and potential mechanism of enhancing Neuregulin1 (NRG1)/v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 4 (ErbB4) expression on the differentiation of induced pluripotent stem cells (iPSCs) into cardiomyocytes.MethodsWe utilized CRISPR-CAS9 technology to knock in ErbB4 and obtained a single-cell clone IPSN-AAVS1-CMV-ErbB4 (iPSCs-ErbB4). Subsequently, we induced the differentiation of iPSCs into cardiomyocytes and quantified the number of beating embryoid bodies. Furthermore, quantitative real-time PCR assessed the expression of cardiomyocyte markers, including ANP (atrial natriuretic peptide), Nkx2.5 (NK2 transcription factor related locus 5), and GATA4 (GATA binding protein 4). On the 14th day of differentiation, we observed the α-MHC (α-myosin heavy chain)-positive area using immunofluorescent staining and conducted western blotting to detect the expression of cTnT (cardiac troponin) protein and PI3K/Akt signaling pathway-related proteins. Additionally, we intervened the iPSCs-ErbB4 + NRG1 group with the PI3K/Akt inhibitor LY294002 and observed alterations in the expression of cardiomyocyte differentiation-related genes.ResultsThe number of beating embryoid bodies increased after promoting the expression of NRG1/ErbB4 compared to the iPSCs control group. Cardiomyocyte markers ANP, Nkx2.5, and GATA4 significantly increased on day 14 of differentiation, and the positive area of α-MHC was three times that of the iPSCs control group. Moreover, there was a marked increase in cTnT protein expression. However, there was no significant difference in cardiomyocyte differentiation between the iPSCs-ErbB4 group and the iPSCs control group. Akt phosphorylation was significantly increased in the iPSCs-ErbB4 + NRG1 group. LY294002 significantly reversed the enhancing effect of NRG1/ErbB4 overexpression on Akt phosphorylation as well as the increase in α-MHC and cTnT expression.ConclusionsIn conclusion, promoting the expression of NRG1/ErbB4 induced the differentiation of iPSC into cardiomyocytes, possibly through modulation of the PI3K/Akt signaling pathway.

Bronchopulmonary dysplasia demonstrates dysregulated autotaxin/lysophosphatidic acid signaling in a neonatal mouse model.

Bronchopulmonary dysplasia (BPD) is a chronic lung disease affecting premature infants who require oxygen supplementation and ventilator therapy to support their underdeveloped lungs. Autotaxin (ATX), an enzyme that generates the bioactive phospholipid lysophosphatidic acid (LPA), which acts via G-protein coupled receptors, has been implicated in numerous pulmonary diseases. In this study, we explored the pathophysiological role of the ATX/LPA signaling pathway in BPD. Neonatal mice were exposed to normoxia or hyperoxia (85%) for 14 days from birth while being treated with vehicle, ATX inhibitor or LPA receptor 1 (LPA1) inhibitor. In vitro studies utilized human lung fibroblast (HLF) cells exposed to room air, 85% oxygen, or LPA for varying time periods. Supernatants and cells were collected for assays and Western blotting. Animals exposed to hyperoxia showed elevated expression of ATX, ATX activity, and LPA1. Inhibiting ATX or LPA1 improved alveolarization, reduced inflammation, and mitigated extracellular matrix deposition and lysyl oxidase (LOX) expression. LPA1 inhibition leading to reduced LOX expression was associated with a reduction in phosphorylation of AKT. Hyperoxia increases the expression of ATX and LPA1 associated with increased LOXin the lungs. Targeting the ATX/LPA1 pathway could be a potential therapeutic approach to BPD. Exposure to hyperoxia increases the expression and activity of autotaxin (ATX), as well as expression of LPA receptor 1 (LPA1). Increased expression of ATX influences extra cellular matrix (ECM) remodeling. Inhibitors targeting the ATX/LPA pathway could offer a new therapeutic approach to bronchopulmonary dysplasia (BPD), potentially mitigating ECM deposition and improving lung development.

CARD9 promotes cholangiocarcinoma by regulating the IL-17A/Hedgehog and the THEM4/AKT/mTOR signaling pathways

Cholangiocarcinoma (CCA) is a highly lethal malignant tumor originating from the bile duct, and its underlying mechanisms are not fully understood. In order to identify key genes in CCA, we downloaded gene expression data from public GSE76297, GSE26566 and TCGA-CHOL datasets. CARD9 was selected as a CCA-related gene from the datasets. Its expression was identified in the CCA tissues via PCR, western blot and immunohistochemistry assays. The loss-and-gain function assay of CARD9 was conducted in CCA cell lines (QBC939 and RBE) and nude mice. This study found a significant upregulation of CARD9 in CCA tissues, which is associated with poor prognosis in patients. Overexpression of CARD9 promotes proliferation and invasion of QBC939 and RBE cells, enhances the growth and development in CCA mouse models, and reduces sensitivity to chemotherapy drugs for CCA. Mechanistically, CARD9 activates the NF-κB and NLRP3 inflammatory signaling pathways, induces excessive release of various inflammatory factors, and triggers a cascade reaction of interleukin-17 (IL-17A). IL-17A promotes the stability of IHH mRNA by regulating HuR, enhances IHH transcription, and activates the Hedgehog signaling pathway to accelerate the progression of CCA. In addition, CARD9 promotes proliferation and invasion of CCA cells by interacting with THEM4, thereby facilitating AKT and mTOR phosphorylation, and accelerating the progression of CCA. Overall, these data suggest that CARD9 is involved in the progression of CCA by regulating the IL-17A/Hedgehog and the THEM4/AKT/mTOR signaling pathways. Therefore, CARD9 may serve as a novel therapeutic target for CCA treatment.

Anticancer Properties Against Select Cancer Cell Lines and Metabolomics Analysis of Tender Coconut Water.

Tender Coconut Water (TCW) is a nutrient-rich dietary supplement that contains in bioactive secondary metabolites and phytohormones with anti-oxidative and anti-inflammatory properties. Studies on TCW's anti-cancer properties are limited and the mechanism of its anti-cancer effects have not been defined. In the present study, we investigate TCW for its anti-cancer properties and, using untargeted metabolomics, we identify components form TCW with potential anti-cancer activity. Cell viability assay, BrdU incorporation assay, soft-agar assay, flow-cytometery, and Western blotting were used to analyze TCW's anticancer properties and to identify mechanism of action. Liquid chromatography- Tandem Mass Spectroscopy (LC-MS/MS) was used to identify TCW components. TCW decreased the viability and anchorage-independent growth of HepG2 hepatocellular carcinoma (HCC) cells and caused S-phase cell cycle arrest. TCW inhibited AKT and ERK phosphorylation leading to reduced ZEB1 protein, increased E-cadherin, and reduced N-cadherin protein expression in HepG2 cells, thus reversing the 'epithelial-to-mesenchymal' (EMT) transition. TCW also decreased the viability of Hep3B hepatoma, HCT-15 colon, MCF-7 and T47D luminal A breast cancer (BC) and MDA-MB-231 and MDA-MB-468 triplenegative BC cells. Importantly, TCW did not inhibit the viability of MCF-10A normal breast epithelial cells. Untargeted metabolomics analysis of TCW identified 271 metabolites, primarily lipids and lipid-like molecules, phenylpropanoids and polyketides, and organic oxygen compounds. We demonstrate that three components from TCW: 3-hydroxy-1-(4-hydroxyphenyl)propan-1-one, iondole-3-carbox aldehyde and caffeic acid inhibit the growth of cancer cells. TCW and its components exhibit anti-cancer effects. TCW inhibits the viability of HepG2 hepatocellular carcinoma cells by reversing the EMT process through inhibition of AKT and ERK signalling.

Tirzepatide, GIP(1-42) and GIP(1-30) display unique signaling profiles at two common GIP receptor variants, E354 and Q354.

Type 2 diabetes (T2D) and obesity are prevalent metabolic disorders affecting millions of individuals worldwide. A new effective therapeutic drug called tirzepatide for the treatment of obesity and T2D is a dual agonist of the GIP receptor and GLP-1 receptor. Tirzepatide is clinically more effective than GLP-1 receptor agonists but the reasons why are not well understood. Tirzepatide reportedly stimulates the GIP receptor more potently than the GLP-1 receptor. However, tirzepatide signaling has not been thoroughly investigated at the E354 (wildtype) or Q354 (E354Q) GIP receptor variants. The E354Q variant is associated increased risk of T2D and lower body mass index. To better understand GIP receptor signaling we characterized the activity of endogenous agonists and tirzepatide at both GIP receptor variants. Using Cos7 cells we examined wildtype and E354Q GIP receptor signaling, analyzing cAMP and IP1 accumulation as well as AKT, ERK1/2 and CREB phosphorylation. GIP(1-42) and GIP(1-30)NH2 displayed equipotent effects on these pathways excluding CREB phosphorylation where GIP(1-30)NH2 was more potent than GIP(1-42) at the E354Q GIP receptor. Tirzepatide favored cAMP signaling at both variants. These findings indicate that tirzepatide is a biased agonist towards Gαs signaling and suggests it equally activates the wildtype and E354Q GIP receptor variants. We also observed differences between the pharmacology of the GIP receptor variants with endogenous peptides, which may help to explain differences in phenotype. These findings contribute to a comprehensive understanding of GIP receptor signaling, and will aid development of therapies combating T2D and obesity.