Bone Marrow-Derived Mesenchymal Stem Cells (BMSCs)-Exosome Carrying MiRNA-312 Inhibits Sevoflurane-Induced Cardiomyocyte Apoptosis Through Activation of Phosphatidylinositol 3-Kinase/Protein Kinase B (PI3K/AKT) Pathway

This study was to explore the mechanism by how exosomes (exo) derived from BMSCs affects cardiomyocyte apoptosis. BMSCs were isolated and incubated with cardiomyocytes while the cardiomyocytes were exposed to sevoflurane or DMSO treatment. Apoptotic cells were calculated and level of apoptosis related proteins was detected by Western blot. Through transfection with microRNA-(miRNA)-312 inhibitor, we evaluated the effect of BMSC-exo on the sevoflurane-induced apoptosis. Sevoflurane significantly inhibited the viability of cardiomyocytes and induced cardiomyocyte apoptosis. Besides, sevoflurane decreased the expression of miR-312 and enhanced Bax expression in cardiomyocytes through restraining the phosphorylation of MAPK/ERK. Treatment with BMSC-exo, however, activated MAPK/ERK signaling by up-regulating miR-312, thereby inhibiting cardiomyocyte apoptosis, promoting cardiomyocyte proliferation, and elevating the level of Bcl-2. In conclusion, BMSC-exo-derived miR-312 inhibits sevoflurane-induced cardiomyocyte apoptosis by activating PI3K/AKT signaling pathway.

Effect of Donepezil on Vascular Dementia in Rats via PI3K/AKT Pathway

Background: Previous studies have shown that Donepezil has therapeutic effects on vascular dementia (VD). PI3K/AKT involves in oxidative stress injury and cell apoptosis. This study investigated whether Donepezil affects the neurological function and apoptosis of VD mice via PI3K/AKT signaling. Methods: Mice were assigned into Sham group, VD group, VD+Donepezil groupfollowed by analysis of mice learning and memory ability by Water maze test, p-AKT expression by Western blot, Caspase-3 activity, MDA content, SOD activity and GSH-Px in hippocampus. HT22 cells were cultured and separated into control group, I-R group and I-R+Donepezil group followed by measuring p-AKT level, ROS content and apoptosis. Results: Learning and memory abilities of VD group mice were significantly decreased, Caspase-3 activity and MDA in brain tissue were significantly increased, along with decreased SOD activity, GSH-Px and p-AKT level. Donepezil treatment can significantly improve VD mice learning and memory ability, reduce Caspase-3 activity and MDA in brain tissue, increase SOD activity, GSH-Px and p-AKT level. In vitro, I-R treatment significantly induced apoptosis of HT22 cells, increased ROS production and decreased p-AKT level. Donepezil treatment could up-regulate p-AKT in HT22 cells and reduce apoptosis and ROS production in HT22 cells. Conclusion: Donepezil improves the function of brain nerve in VD mice through regulating PI3K/AKT pathway, thus reducing oxidative stress injury and apoptosis of brain nerve cells.

MicroRNA-517c Functions as a Tumor Suppressor in Hepatocellular Carcinoma via Downregulation of KPNA2 and Inhibition of PI3K/AKT Pathway

Objective. Hepatocellular carcinoma (HCC) is a kind of solid and highly aggressive malignant tumor with poor prognosis. MicroRNA (miRNA/miR) has been confirmed to be involved in HCC development. The current study focused on the functions and mechanisms of miR-517c in HCC. Methods. Expressions of miR-517c and Karyopherin α2 (KPNA2) mRNA in HCC cell lines and tissue samples were examined using quantitative real-time polymerase chain reaction (qRT-PCR). Western blot was conducted for detections of epithelial-to-mesenchymal transition (EMT) and PI3K/AKT markers. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and Transwell assays were utilized to investigate the influence of miR-517c on HCC cell proliferation, invasion, and migration. TargetScan and luciferase reporter assay were performed to search for the potential target gene of miR-517c. Results. We demonstrated that miR-517c expressions were decreased in HCC tissues and cells. Moreover, the clinical analysis showed that decreased miR-517c expressions in HCC tissues correlated with shorter overall survival and malignant clinicopathologic features of HCC patients. MTT assay showed that miR-517c upregulation prominently repressed HCC cell proliferation. In addition, miR-517c restoration could significantly suppress HCC cell invasion and migration as demonstrated by Transwell assays. We also found that miR-517c directly targeted KPNA2 and regulated the PI3K/AKT pathway and EMT, exerting prohibitory functions in HCC. Conclusion. Taken together, this study stated that miR-517c inhibited HCC progression via regulating the PI3K/AKT pathway and EMT and targeting KPNA2 in HCC, providing a novel insight into HCC treatment.

Maternal High-Fat Diet Alters the Characteristics of Astrocytes and Worsens the Outcome of Stroke in Rat Offspring, Which Improves After FGF21 Administration

Background: Maternal high-fat diet (MHFD) has been shown to increase susceptibility to neurological disease in later offspring, but the underlying mechanism is not clear. Fibroblast growth factor 21 (FGF21) has been reported to have a neuroprotective effect in stroke, but its mechanism of action remains unknown. In this study, we investigated the mechanism of the effect of MHFD on stroke in offspring in adulthood and the mechanism by which FGF21 acts on stroke and restores neurological function.Methods: We performed transcriptome sequencing analysis on D21 neonatal rats. Bodyweight and blood indicators were recorded in the adult rats after MHFD. FGF21 was administered 7 h after photochemical modeling twice a day for three consecutive days.Results: We found numerous mRNA changes between the MHFD group and a normal maternal normal diet (MND) group at D21, including genes related to astrocyte and PI3K/Akt pathways. The body weight, blood glucose, and triglycerides of the MHFD offspring were higher, ischemic lesions were larger, the number of activated astrocytes was lower, and the neurological function score was worse than that of the MND group. After FGF21 administration, WB and qPCR analyses showed that astrocytes and the PI3K/Akt pathway were upregulated, while NF-κB and inflammatory cytokines expression were inhibited in stroke and peri-stroke regions.Conclusion: Taken together, we conclude that MHFD alters the characteristics of astrocytes and other transcriptome changes in their offspring, leading to a worse prognosis of stroke, while FGF21 plays a neuroprotective role by inhibiting NF-κB and inflammatory factors and activating the PI3K/Akt pathway and activating more astrocytes in the MND group than the MHFD group.

Therapeutic targeting of ARID1A and PI3K/AKT pathway alterations in cholangiocarcinoma

Background Genetic alterations in ARID1A were detected at a high frequency in cholangiocarcinoma (CCA). Growing evidence indicates that the loss of ARID1A expression leads to activation of the PI3K/AKT pathway and increasing sensitivity of ARID1A-deficient cells for treatment with the PI3K/AKT inhibitor. Therefore, we investigated the association between genetic alterations of ARID1A and the PI3K/AKT pathway and evaluated the effect of AKT inhibition on ARID1A-deficient CCA cells. Methods Alterations of ARID1A, PI3K/AKT pathway-related genes, clinicopathological data and overall survival of 795 CCA patients were retrieved from cBio Cancer Genomics Portal (cBioPortal) databases. The association between genetic alterations and clinical data were analyzed. The effect of the AKT inhibitor (MK-2206) on ARID1A-deficient CCA cell lines and stable ARID1A-knockdown cell lines was investigated. Cell viability, apoptosis, and expression of AKT signaling were analyzed using an MTT assay, flow cytometry, and Western blots, respectively. Results The analysis of a total of 795 CCA samples revealed that ARID1A alterations significantly co-occurred with mutations of EPHA2 (p < 0.001), PIK3CA (p = 0.047), and LAMA1 (p = 0.024). Among the EPHA2 mutant CCA tumors, 82% of EPHA2 mutant tumors co-occurred with ARID1A truncating mutations. CCA tumors with ARID1A and EPHA2 mutations correlated with better survival compared to tumors with ARID1A mutations alone. We detected that 30% of patients with PIK3CA driver missense mutations harbored ARID1A-truncated mutations and 60% of LAMA1-mutated CCA co-occurred with truncating mutations of ARID1A. Interestingly, ARID1A-deficient CCA cell lines and ARID1A-knockdown CCA cells led to increased sensitivity to treatment with MK-2206 compared to the control. Treatment with MK-2206 induced apoptosis in ARID1A-knockdown KKU-213A and HUCCT1 cell lines and decreased the expression of pAKTS473 and mTOR. Conclusion These findings suggest a dependency of ARID1A-deficient CCA tumors with the activation of the PI3K/AKT-pathway, and that they may be more vulnerable to selective AKT pathway inhibitors which can be used therapeutically.

Albumin Expands Albumin Reabsorption Capacity in Proximal Tubule Epithelial Cells through a Positive Feedback Loop between AKT and Megalin

Renal proximal tubule cells (PTECs) act as urine gatekeepers, constantly and efficiently avoiding urinary protein waste through receptor-mediated endocytosis. Despite its importance, little is known about how this process is modulated in physiologic conditions. Data suggest that the phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT) pathway regulates PTEC protein reabsorption. Here, we worked on the hypothesis that the physiologic albumin concentration and PI3K/AKT pathway form a positive feedback loop to expand endocytic capacity. Using LLC-PK1 cells, a model of PTECs, we showed that the PI3K/AKT pathway is required for megalin recycling and surface expression, affecting albumin uptake. Inhibition of this pathway stalls megalin at EEA1+ endosomes. Physiologic albumin concentration (0.01 mg/mL) activated AKT; this depends on megalin-mediated albumin endocytosis and requires previous activation of PI3K/mTORC2. This effect is correlated to the increase in albumin endocytosis, a phenomenon that we refer to as “albumin-induced albumin endocytosis”. Mice treated with L-lysine present decreased albumin endocytosis leading to proteinuria and albuminuria associated with inhibition of AKT activity. Renal cortex explants obtained from control mice treated with MK-2206 decreased albumin uptake and promoted megalin internalization. Our data highlight the mechanism behind the capacity of PTECs to adapt albumin reabsorption to physiologic fluctuations in its filtration, avoiding urinary excretion.

Extracellular vesicles derived from glioblastoma promote proliferation and migration of neural progenitor cells via PI3K-Akt pathway

Background Glioblastomas are lethal brain tumors under the current combinatorial therapeutic strategy that includes surgery, chemo- and radio-therapies. Extensive changes in the tumor microenvironment is a key reason for resistance to chemo- or radio-therapy and frequent tumor recurrences. Understanding the tumor-nontumor cell interaction in TME is critical for developing new therapy. Glioblastomas are known to recruit normal cells in their environs to sustain growth and encroachment into other regions. Neural progenitor cells (NPCs) have been noted to migrate towards the site of glioblastomas, however, the detailed mechanisms underlying glioblastoma-mediated NPCs’ alteration remain unkown. Methods We collected EVs in the culture medium of three classic glioblastoma cell lines, U87 and A172 (male cell lines), and LN229 (female cell line). U87, A172, and LN229 were co-cultured with their corresponding EVs, respectively. Mouse NPCs (mNPCs) were co-cultured with glioblastoma-derived EVs. The proliferation and migration of tumor cells and mNPCs after EVs treatment were examined. Proteomic analysis and western blotting were utilized to identify the underlying mechanisms of glioblastoma-derived EVs-induced alterations in mNPCs. Results We first show that glioblastoma cell lines U87-, A172-, and LN229-derived EVs were essential for glioblastoma cell prolifeartion and migration. We then demonstrated that glioblastoma-derived EVs dramatically promoted NPC proliferation and migration. Mechanistic studies identify that glioblastoma-derived EVs achieve their functions via activating PI3K-Akt-mTOR pathway in mNPCs. Inhibiting PI3K-Akt pathway reversed the elevated prolfieration and migration of glioblastoma-derived EVs-treated mNPCs. Conclusion Our findings demonstrate that EVs play a key role in intercellular communication in tumor microenvironment. Inhibition of the tumorgenic EVs-mediated PI3K-Akt-mTOR pathway activation might be a novel strategy to shed light on glioblastoma therapy.

TRIP13 Activates the PI3K/AKT Signal Pathway to Promote Melanoma Progression by Interacting With FLNA

Background: Skin melanoma is a malignant tumor originated from skin melanocytes. It is highly malignant and easy to relapse and metastasis. Finding new diagnostic and therapeutic targets has become a hot issue. Accumulating evidence now indicates that thyroid hormone receptor interactor 13 (TRIP13) plays important roles in tumor development. However, its role in melanoma remains unclear.Methods: Bioinformatic analyses were employed to excavate crucial genes in melanoma using several public databases. The expression of TRIP13 was detected by immunohistochemistry. MV3 cell and A2058 cell were steadily transfected with TRIP13 knock-down or overexpression lentiviruses, then the function and potential mechanism of TRIP13 were studied in vitro and in vivo. Co-immunoprecipitation (Co-IP) and mass spectrum were employed to screen out the interacting molecule of TRIP13.Results: Our results showed that TRIP13 was generally upregulated in melanoma tissues and was related to the poor prognosis of melanoma patients. The overexpression of TRIP13 promotes the invasion, migration and EMT transformation of melanoma cells in vitro, and promotes lung metastasis in vivo. Mechanismly, TRIP13 interacts with FLNA, and activates the PI3K/AKT pathway, and then induces melanoma migration, invasion and EMT transformation.Conclusion: Elevated TRIP13 drives tumor progression via the FLNA/PI3K/AKT axis, and TRIP13 is a innovative prognostic molecule and potential target of targeted therapy in melanoma.