Alleviatory effect of isoquercetin on benign prostatic hyperplasia via IGF-1/PI3K/Akt/mTOR pathway

We evaluated the effect of isoquercetin(quercetin-O-3-glucoside-quercetin,IQ)as a functional component of Abeliophyllum disistichum Nakai ethanol extract(ADLE)on prostate cell proliferation and apoptosis and its effects on the IGF-1/PI3K/Akt/mTOR pathway in benign prostatic hyperplasia(BPH).Metabolites in ADLE were analyzed using UHPLC-qTOF-MS and HPLC.IQ was orally administered(1 or 10 mg/kg)to a testosterone propionate-induced BPH rat model,and its effects on the prostate weight were evaluated.The effect of IQ on androgen receptor(AR)signaling was analyzed in LNCaP cells.Whether IGF-1 and IQ affect the IGF-1/PI3K/Akt/mTOR pathway in BPH-1 cells was also examined.The metabolites in ADLE were identified and quantified,which confirmed that ADLE contained abundant IQ(20.88 mg/g).IQ significantly reduced the prostate size in a concentration-dependent manner in a BPH rat model,and significantly decreased the expression of AR signaling factors in the rat prostate tissue and LNCaP cells in a concentration-dependent manner.IQ also inhibited the PI3K/AKT/mTOR pathway activated by IGF-1 treatment in BPH-1 cells.In BPH-1 cells,IQ led to G0/G1 arrest and suppressed the expression of proliferation factors while inducing apoptosis.Thus,IQ shows potential for use as a pharmaceutical and nutraceutical for BPH.

LAMC2 regulates proliferation, migration, and invasion mediated by the Pl3K/AKT/mTOR pathway in oral

Background:Oral squamous cell carcinoma(OSCC)is a common malignant tumor.Recently,Laminin Gamma 2(LAMC2)has been shown to be abnormally expressed in OSCC;however,how LAMC2 signaling contributes to the occurrence and development of OSCC and the role of autophagy in OSCC has not been fully explored.This study aimed to analyze the role and mechanism of LAMC2 signaling in OSCC and the involvement of autophagy in OSCC.Methods:To explore the mechanism by which LAMC2 is highly expressed in OSCC,we used small interfering RNA(siRNA)to knock down LAMC2 to further observe the changes in the signaling pathway.Furthermore,we used cell proliferation assays,Transwell invasion assays,and wound-healing assays to observe the changes in OSCC proliferation,invasion,and metastasis.RFP-LC3 was used to detect the level of autophagy intensity.A cell line-derived xenograft(CDX)model was used to detect the effect of LAMC2 on tumor growth in vivo.Results:This study found that the level of autophagy was correlated with the biological behavior of OSCC.The downregulation of LAMC2 activated autophagy and inhibited OSCC proliferation,invasion,and metastasis via inhibiting the PI3K/AKT/mTOR pathway.Moreover,autophagy has a dual effect on OSCC,and the synergistic downregulation of LAMC2 and autophagy can inhibit OSCC metastasis,invasion,and proliferation via the PI3K/AKT/mTOR pathway.Conclusions:LAMC2 interacts with autophagy to regulate OSCC metastasis,invasion,and proliferation via the PI3K/AKT/mTOR pathway.LAMC2 down-regulation can synergistically modulate autophagy to inhibit OSCC migration,invasion,and proliferation.

Echinoside A from Pearsonothuria graeffei Exert the Cytotoxicity to MDA-MB-231 Cells via Mitochondrial Membrane and Modulation of PI3K/Akt/mTOR Pathway

A kind of triterpene glycosides echinoside A(EA)was extracted from sea cucumber Pearsonothuria graeffei,and its yield was about 0.78%.The purity of EA was 99.0%,and its molecular weight was 1206 Da.EA was a linear tetrasaccharide attached to a pentacyclic triterpene aglycon.It inhibited the growth of MDA-MB-231 cells in vitro.The antitumor effect was related to elevate ROS level,decrease mitochondrial membrane potential,enhance caspase-3 expression,induce cells apoptosis and arrest cell cycle at G2/M phase.EA also dose-dependently suppressed the expressions of phophorylation proteins p-PI3K,p-Akt,and p-mTOR as analyzed by western blotting.These results suggested that EA caused MDA-MB-231 cells apoptosis via intrinsic mitochondrial and PI3K/Akt/mTOR pathway.EA can be a potential anti-breast cancer agent to enhance the clinical efficacy.

Niuhuang(Bovis Calculus)-Shexiang(Moschus)combination induces apoptosis and inhibits proliferation in hepatocellular carcinoma via PI3K/AKT/mTOR pathway

Objective To investigate the effects of Niuhuang(Bovis Calculus,BC)and Shexiang(Moschus)(BC-Moschus)on human hepatocellular carcinoma(HCC)cells SMMC-7721 and a nude mouse model of subcutaneous xenografts,and to explore its anti-HCC mechanism.Methods The BC-Moschus combination was applied to two liver cancer models in vivo and in vitro.SMMC-7721 was divided into the BC-Moschus group and the control group,and different doses(rude drug dosage 0.625,1.25,2.5,and 5 mg/m L)of BC-Moschus extract were used for the intervention.The proliferation ability of HCC cells was detected using the Cell Counting Kit-8(CCK-8)assay,and the migration ability was detected by a wound healing assay.A subcutaneous xenograft model was prepared using nude mice with human HCC.Specific pathogen-free-grade BALB/c nude mice(5-week-old)were randomly divided into the following groups(n=6 per group):control(0.9%physiological saline 0.2 m L/d),BC-Moschus[BC 45.5 mg/(kg·d)+Moschus 13 mg/(kg·d)],and cisplatin(DDP,intraperitoneal injection5 mg/kg per week)groups.All groups were administered for 14 d.The volume and mass of the subcutaneous xenografts in nude mice were observed.The expression levels of phosphatidylinositol-3 kinase/protein kinase B/mammalian target of rapamycin(PI3K/AKT/mTOR)pathway,apoptosis-associated factor p70 S6 Kinase(S6K),Bax,Bcl-2,caspase-3,and caspase-9 in nude mice subcutaneous xenografts were measured by real-time quantitative PCR(RT-qPCR)and Western blot.Terminal Deoxynucleotidy Transferase-Mediated d UTP NickEnd Labeling(TUNEL)was used for quantitative analysis of apoptotic cells.Results The CCK-8 assay demonstrated that the BC-Moschus combination inhibited HCC cell proliferation in a superior manner to the use of BC and Moschus alone,and the inhibition effect was dose-and time-dependent(P<0.01).The wound healing assay showed that the BC-Moschus combination inhibited HCC cell migration(P<0.01).In the subcutaneous xenograft model of nude mice with human HCC,we found that the tumor volume and weight of the BC-Moschus group were lower than those of the control group(P<0.01).The levels of the PI3K/AKT/m TOR signaling pathway and S6K protein in the BC-Moschus and DDP groups were significantly decreased(P<0.01).The expression level of the anti-apoptotic gene Bcl-2 was downregulated(P<0.05),and the expression of the pro-apoptotic gene Baxand apoptosis-related factors caspase-3 and caspase-9 were significantly upregulated(P<0.01).The TUNEL assays further confirmed that the combination of the BC-Moschuas could promote HCC(P<0.01).Conclusion The BC-Moschus combination inhibited the proliferation and migration ability of HCC cells SMMC-7721 and effectively inhibited the growth of subcutaneous xenografts in nude mice.The mechanism may be closely related to the downregulation of the PI3K/AKT/mTOR pathway,regulation of apoptosis-related protein caspase-3,caspase-9,Bcl-2,and Bax expression,and promotion of apoptosis.

The molecular genetics of PI3K/PTEN/AKT/mTOR pathway in the malformations of cortical development

Malformations of cortical development(MCD)are a group of developmental disorders characterized by abnormal cortical structures caused by genetic or harmful environmental factors.Many kinds of MCD are caused by genetic variation.MCD is the common cause of intellectual disability and intractable epilepsy.With rapid advances in imaging and sequencing technologies,the diagnostic rate of MCD has been increasing,and many potential genes causing MCD have been successively identified.However,the high genetic heterogeneity of MCD makes it challenging to understand the molecular pathogenesis of MCD and to identify effective targeted drugs.Thus,in this review,we outline important events of cortical development.Then we illustrate the progress of molecular genetic studies about MCD focusing on the PI3K/PTEN/AKT/mTOR pathway.Finally,we briefly discuss the diagnostic methods,disease models,and therapeutic strategies for MCD.The information will facilitate further research on MCD.Understanding the role of the PI3K/PTEN/AKT/mTOR pathway in MCD could lead to a novel strategy for treating MCD-related diseases.

Spi1 regulates the microglial/macrophage inflammatory response via the PI3K/AKT/mTOR signaling pathway after intracerebral hemorrhage

Preclinical and clinical studies have shown that microglia and macrophages participate in a multiphasic brain damage repair process following intracerebral hemorrhage.The E26 transformation-specific sequence-related transcription factor Spi1 regulates microglial/macrophage commitment and maturation.However,the effect of Spi1 on intracerebral hemorrhage remains unclear.In this study,we found that Spi1 may regulate recovery from the neuroinflammation and neurofunctional damage caused by intracerebral hemorrhage by modulating the microglial/macrophage transcriptome.We showed that high Spi1expression in microglia/macrophages after intracerebral hemorrhage is associated with the activation of many pathways that promote phagocytosis,glycolysis,and autophagy,as well as debris clearance and sustained remyelination.Notably,microglia with higher levels of Soil expression were chara cterized by activation of pathways associated with a variety of hemorrhage-related cellular processes,such as complement activation,angiogenesis,and coagulation.In conclusion,our results suggest that Spi1 plays a vital role in the microglial/macrophage inflammatory response following intracerebral hemorrhage.This new insight into the regulation of Spi1 and its target genes may advance our understanding of neuroinflammation in intracerebral hemorrhage and provide therapeutic targets for patients with intracerebral hemorrhage.

PI3K/AKT/mTOR pathway,hypoxia,and glucose metabolism:Potential targets to overcome radioresistance in small cell lung cancer

Small cell lung cancer(SCLC)is a highly aggressive tumor type for which limited therapeutic progress has been made.Platinum-based chemotherapy with or without thoracic radiotherapy remains the backbone of treatment,but most patients with SCLC acquire therapeutic resistance.Given the need for more effective therapies,better elucidation of the molecular pathogenesis of SCLC is imperative.The phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)pathway is frequently activated in SCLC and strongly associated with resistance to ionizing radiation in many solid tumors.This pathway is an important regulator of cancer cell glucose metabolism,and its activation probably effects radioresistance by influencing bioenergetic processes in SCLC.Glucose metabolism has three main branches-aerobic glycolysis,oxidative phosphorylation,and the pentose phosphate pathway-involved in radioresistance.The interaction between the PI3K/AKT/mTOR pathway and glucose metabolism is largely mediated by hypoxia-inducible factor 1(HIF-1)signaling.The PI3K/AKT/mTOR pathway also influences glucose metabolism through other mechanisms to participate in radioresistance,including inhibiting the ubiquitination of rate-limiting enzymes of the pentose phosphate pathway.This review summarizes our understanding of links among the PI3K/AKT/mTOR pathway,hypoxia,and glucose metabolism in SCLC radioresistance and highlights promising research directions to promote cancer cell death and improve the clinical outcome of patients with this devastating disease.

Novel insights into mTOR signalling pathways: A paradigm for targeted tumor therapy

As a crucial protein kinase,the mammalian target of rapamycin(mTOR)intimately controls essential cellular processes like cell development,proliferation,metabolism,and other crucial activities.Different cancers and disorders have been linked to imbalances in mTOR's regulatory systems.Multiple mTOR inhibitor therapy has recently acquired popularity as a method of treating cancers brought on by abnormal signal transduction pathways.We also explore potential processes behind tumor cell resistance to mTOR inhibitors and suggest workarounds to overcome this challenge.We hold the potential to pioneer cutting-edge methods for tumor therapy by methodically examining the complex mTOR signaling system and its regulatory complexity.Increasing our knowledge of mTOR-related mechanisms not only creates opportunities for cutting-edge methods to target and treat cancers but also has the potential to improve patient outcomes and general quality of life significantly.This review paper explores the most recent developments in understanding mTOR signaling pathways and the use of mTOR inhibitors in treating tumors.

Qili Qiangxin, a compound herbal medicine formula, alleviates hypoxia-reoxygenation-induced apoptotic and autophagic cell death via suppression of ROS/AMPK/mTOR pathway in vitro

Objective: Qili Qiangxin(QLQX), a compound herbal medicine formula, is used effectively to treat congestive heart failure in China. However, the molecular mechanisms of the cardioprotective effect are still unclear. This study explores the cardioprotective effect and mechanism of QLQX using the hypoxiareoxygenation(H/R)-induced myocardial injury model.Methods: The main chemical constituents of QLQX were analyzed using high-performance liquid chromatography-evaporative light-scattering detection. The model of H/R-induced myocardial injury in H9c2 cells was developed to simulate myocardial ischemia–reperfusion injury. Apoptosis, autophagy,and generation of reactive oxygen species(ROS) were measured to assess the protective effect of QLQX. Proteins related to autophagy, apoptosis and signalling pathways were detected using Western blotting.Results: Apoptosis, autophagy and the excessive production of ROS induced by H/R were significantly reduced after treating the H9c2 cells with QLQX. QLQX treatment at concentrations of 50 and 250 μg/mL caused significant reduction in the levels of LC3Ⅱ and p62 degradation(P < 0.05), and also suppressed the AMPK/mTOR signalling pathway. Furthermore, the AMPK inhibitor Compound C(at 0.5 μmol/L),and QLQX(250 μg/mL) significantly inhibited H/R-induced autophagy and apoptosis(P < 0.01), while AICAR(an AMPK activator, at 0.5 mmol/L) increased cardiomyocyte apoptosis and autophagy and abolished the anti-apoptotic effect of QLQX. Similar phenomena were also observed on the expressions of apoptotic and autophagic proteins, demonstrating that QLQX reduced the apoptosis and autophagy in the H/R-induced injury model via inhibiting the AMPK/mTOR pathway. Moreover, ROS scavenger,N-Acetyl-L-cysteine(NAC, at 2.5 mmol/L), significantly reduced H/R-triggered cell apoptosis and autophagy(P < 0.01). Meanwhile, NAC treatment down-regulated the ratio of phosphorylation of AMPK/AMPK(P < 0.01), which showed a similar effect to QLQX.Conclusion: QLQX plays a cardioprotective role by alleviating apoptotic and autophagic cell death through inhibition of the ROS/AMPK/mTOR signalling pathway.

Total Saponins of Panax notoginseng Activate Akt/mTOR Pathway and Exhibit Neuroprotection in vitro and in vivo against Ischemic Damage

Objective:To reveal the neuroprotective effect and the underlying mechanisms of a mixture of the main components of Panax notoginseng saponins(TSPN)on cerebral ischemia-reperfusion injury and oxygenglucose deprivation/reoxygenation(OGD/R)of cultured cortical neurons.Methods:The neuroprotective effect of TSPN was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT)assay,flow cytometry and live/dead cell assays.The morphology of dendrites was detected by immunofluorescence.Middle cerebral artery occlusion(MCAO)was developed in rats as a model of cerebral ischemia-reperfusion.The neuroprotective effect of TSPN was evaluated by neurological scoring,tail suspension test,2,3,5-triphenyltetrazolium chloride(TTC)and Nissl stainings.Western blot analysis,immunohistochemistry and immunofluorescence were used to measure the changes in the Akt/mammalian target of rapamycin(mTOR)signaling pathway.Results:MTT showed that TSPN(50,25 and 12.5μg/m L)protected cortical neurons after OGD/R treatment(P<0.01 or P<0.05).Flow cytometry and live/dead cell assays indicated that 25μg/m L TSPN decreased neuronal apoptosis(P<0.05),and immunofluorescence showed that 25μg/m L TSPN restored the dendritic morphology of damaged neurons(P<0.05).Moreover,12.5μg/m L TSPN downregulated the expression of Beclin-1,Cleaved-caspase 3 and LC3 B-Ⅱ/LC3 B-Ⅰ,and upregulated the levels of phosphorylated(p)-Akt and p-mTOR(P<0.01 or P<0.05).In the MCAO model,50μg/m L TSPN improved defective neurological behavior and reduced infarct volume(P<0.05).Moreover,the expression of Beclin-1 and LC3 B in cerebral ischemic penumbra was downregulated after 50μg/m L TSPN treatment,whereas the p-mTOR level was upregulated(P<0.05 or P<0.01).Conclusions:TSPN promoted neuronal survival and protected dendrite integrity after OGD/R and had a potential therapeutic effect by alleviating neurological deficits and reversing neuronal loss.TSPN promoted p-mTOR and inhibited Beclin-1 to alleviate ischemic damage,which may be the mechanism that underlies the neuroprotective activity of TSPN.

The role of the PI3K/AKT/mTOR pathway in brain tumor metastasis

The PI3K/AKT/mTOR(PAM)pathway is involved in a variety of cellular functions and often contributes to oncogenesis and cancer progression.It has been recognized that this pathway is frequently activated in the most common central nervous system cancers of adults and children,malignant gliomas and medulloblastomas(MB).In these tumors,the PAM network controls key functions necessary for cell invasion and metastasis,such as cell motility.This review summarizes the current knowledge about the role of PAM signaling in cell invasion and metastasis in gliomas and MB.Current approaches to inhibit cell invasion and metastasis by targeting the PAM pathway will also be discussed.

Targeting the PI3K/AKT/mTOR pathway in epithelial ovarian cancer,therapeutic treatment options for platinum-resistant ovarian cancer

The survival rates for women with ovarian cancer have shown scant improvement in recent years,with a 5-year survival rate of less than 40%for women diagnosed with advanced ovarian cancer.High-grade serous ovarian cancer(HGSOC)is the most lethal subtype where the majority of women develop recurrent disease and chemotherapy resistance,despite over 70%-80%of patients initially responding to platinum-based chemotherapy.The phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)signaling pathway regulates many vital processes such as cell growth,survival and metabolism.However,this pathway is frequently dysregulated in cancers including different subtypes of ovarian cancer,through amplification or somatic mutations of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha(PIK3CA),amplification of AKT isoforms,or deletion or inactivation of PTEN.Further evidence indicates a role for the PI3K/AKT/mTOR pathway in the development of chemotherapy resistance in ovarian cancer.Thus,targeting key nodes of the PI3K/AKT/mTOR pathway is a potential therapeutic prospect.In this review,we outline dysregulation of PI3K signaling in ovarian cancer,with a particular emphasis on HGSOC and platinum-resistant disease.We review pre-clinical evidence for inhibitors of the main components of the PI3K pathway and highlight past,current and upcoming trials in ovarian cancers for different inhibitors of the pathway.Whilst no inhibitors of the PI3K/AKT/mTOR pathway have thus far advanced to the clinic for the treatment of ovarian cancer,several promising compounds which have the potential to restore platinum sensitivity and improve clinical outcomes for patients are under evaluation and in various phases of clinical trials.

Mu-Xiang-You-Fang protects PC12 cells against OGD/R-induced autophagy via AMPK/mTOR signaling pathway

OBJECTIVE Mu-Xiang-You-Fang(MXYF)is a classic prescription of Hui medicine,composed of five herbs,which has been used to treat ischemic stroke for many years.However,the potential pharmacological mecha⁃nisms of MXYF remain unclear.The present research is to investigate the neuroprotective effect of MXYF and its role in modulating autophagy via AMPK/mTOR signaling pathway in the PC12 oxygen-glucose deprivation and reperfusion(OGD/R)injury model.METHODS MXYF was extracted by supercritical CO2 fluid extraction apparatus.PC12 OGD/R injury model was established by oxygen-glucose deprivation for 2 h and reperfusion for 24 h.The effects of MXYF on the viability and cytotoxicity of PC12 cells were determined through cell counting kit(CCK-8)assay.Colorimetric method was performed to determine the LDH leakage rate.The calcium concentration was determined by chemical fluorescence method and the mitochondrial membrane potential was determined through flow cytometry.Monodansylcadaverine(MDC)staining was conducted to detect autophagosome formation.The expression of LC3,Beclin1,p62,p-AMPK,ULK1,p-mTOR and p-p70s6k proteins were determined by immunofluorescence and Western blotting analyses.RESULTS MXYF(1,2 and 4 mg·L^-1)could significantly increase the cell viability and mitochondrial membrane potential,while decreased the release of lactate dehydrogenase(LDH)and calcium concentration in PC12 cells.Mechanistic studies showed that MXYF reduced the LC3-II/LC3-I ratio and inhibited the expression of beclin1,p-AMPK and ULK1.In comparison,the expres⁃sion of p-mTOR,p-p70s6k and p62 were significantly enhanced.CONCLUSION MXYF inhibits autophagy after OGD/Rinduced PC12 cell injury through AMPK-mTOR pathway,thus MXYF might have therapeutic potential for treating the ischemic stroke.

Salicylic acid sensitizes cervical cancer cells to radiotherapy by activating AMPK/TSC2/mTOR pathway

Objective:To investigate the radio-sensitizing effect of salicylic acid(SA)on human cervical cancer cells and its potential molecular mechanism.Methods:Cervical cancer cells were treated with SA and ionizing radiation.The expression ofγ-H2AX was evaluated by immunofluorescence(IF)assay.Cell cycle and apoptosis were analyzed by flow cytometry.Western blot was performed to detect the protein level of AMPK/TSC2/mTOR pathway.Results:SA inhibited basal proliferation of cervical cancer cells in a dose and time dependent manner.In addition,SA increased radiation-induced DNA damage,promoted apoptosis,triggered a redistribution of cell cycle from G2-M phase to G1-S phase of cervical cancer cells,and hence increased cell sensitivity to radiation.Moreover,SA treatment elevated the expression levels of p-AMPKα(t=3.996,P<0.05)and p-TSC2(t=5.308,P<0.05),whereas the level of p-mTOR(t=10.160,P<0.05)was significantly decreased.Conclusion:SA enhances the radiosensitivity of cervical cancer cells by targeting AMPK/TSC2/mTOR signaling pathway,and might serve as a promising therapeutic strategy to improve the efficacy of radiotherapy for cervical cancer.

The Effect of Increasing mTOR Signaling on the Speed of Regeneration in D. dorotocephala planaria

Muscle strains are a common injury that can occur during physical activity or exercise, and they can range from mild to severe depending on the extent of the damage. The mTOR pathway is a highly conserved signaling pathway that has been implicated in various cellular processes, including tissue regeneration. Previous studies that have investigated protein synthesis in mice have concluded that the mTOR pathway can improve muscle regeneration. However, the specific effects of mTOR pathway activation on muscle regeneration in planarians have yet to be fully explored. Therefore, this study aimed to investigate the use of Arginine and Leucine to stimulate the mTOR pathway for muscle strains in planarians. During the experiment, planarians were amputated, and different dosages of Arginine and Leucine were used to stimulate the mTOR pathway in Dugesia dorotocephala. The speed of muscle regeneration was measured over 14 days in five groups, with thirty planarians in each group. The results showed that the rate of regeneration from 0.134 mM Leucine solution showed a significant increase compared to the control group, while the groups exposed to 0.1, 0.3 mM Arginine, and 0.0134 Leucine did not show significant changes in muscle regeneration. These findings suggest that mTOR pathway activation may enhance muscle regeneration in planarians and that the effects may be dose-dependent. These findings have important implications for developing new treatments for tissue damage. Further studies are needed to fully understand the mechanisms of mTOR pathway activation on muscle regeneration in planarians and its potential use in tissue engineering and regenerative medicine.

CD26 upregulates proliferation and invasion in keloid fibroblasts through an IGF-1-induced PI3K/AKT/mTOR pathway

Background:Keloid is a fibrotic dermal disease characterized by an abnormal increase in fibroblast proliferation and invasion.These pathological behaviours may be related to the heterogeneity of keloid fibroblasts(KFs);however,because of a lack of effective biomarkers for KFs it is difficult to study the underlying mechanism.Our previous studies revealed that the expansion of CD26+KFs was responsible for increased keloid proliferation and invasion capabilities;the intrinsic relationship and mechanism between CD26 and keloid is therefore worthy of further investigation.The aim of this studywas to explore molecular mechanisms in the process of CD26 upregulated KFs proliferation and invasion abilities,and provide more evidence for CD26 as an effective biomarker of keloid and a new clinical therapeutic target.Methods:Flow cytometry was performed to isolate CD26+/CD26−fibroblasts from KFs and normal fibroblasts.To generate stably silenced KFs for CD26 and insulin-like growth factor-1 receptor(IGF-1R),lentiviral particles encoding shRNA targeting CD26 and IGF-1R were used for transfection.Cell proliferations were analysed by cell counting kit-8 assay and 5-ethynyl-2-deoxyuridine(EdU)incorporation assay.Scratching assay and transwell assay were used to assess cell migration and invasion abilities.To further quantify the regulatory role of CD26 expression in the relevant signalling pathway,RT-qPCR,western blot,ELISA,PI3K activity assay and immunofluorescence were used.Results:Aberrant expression of CD26 in KFs was proven to be associated with increased proliferation and invasion of KFs.Furthermore,the role of the IGF-1/IGF-1 receptor axis was also studied in CD26 and was found to upregulate KF proliferation and invasion.The PI3K/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)pathway was shown to affect CD26-regulated KF proliferation and invasion by increasing phosphorylation levels of S6 kinase and 4E-binding protein.Conclusions:CD26 can be the effective biomarker for KFs,and its expression is closely related to proliferation and invasion in keloids through the IGF-1-induced PI3K/AKT/mTOR pathway.This work provides a novel perspective on the pathological mechanisms affecting KFs and therapeutic strategies against keloids.

PI3K/AKT/mTOR signaling pathway inhibitors in proliferation of retinal pigment epithelial cells

AIM: To determine whether the PI3K/AKT/mTOR pathway is activated in proliferative vitreoretinopathy (PVR) in homo-sapiens. METHODS: The retina of controls and patients with PVR were collected and their levels of PI3K, phospho-AKT, phospho-mTOR, phospho-p70S6k and phospho-4EBP-1 were determined by Western blot. The cultured human retinal pigment epithelial cell line D407 was treated with a specific mTOR inhibitor, rapamycin (RAPA) or a PI3K inhibitor, LY294002, of various concentrations and durations. Cell morphology was observed by phase contrast microscopy and the proliferation and apoptosis of treated cells were determined by MTT assay and flow cytometry. RESULTS: Levels of PI3K, phospho-AKT, phospho-mTOR, phospho-P70S6K and phospho-4EBP1 was increased in the retina in PVR (P <0.05). In D407 cells, both RAPA and LY294002 significantly inhibited cell proliferation and cell cycle progression, and promoted apoptosis (P <0.05); morphologically, the cells became smaller. Both RAPA and LY294002 reduced levels of phospho-AKT, phospho-mTOR, phospho-p70S6k and phospho-4EBP1 expression (P <0.05). RAPA, but not LY294002, had no significant effect on PI3K expression. CONCLUSION: PI3K/AKT/mTOR signaling pathway is highly activated in the retinal pigment epithelial cells of PVR. The inhibitors of PI3K/AKT/mTOR signaling pathway, RAPA and LY294002, could inhibited the PI3K/AKT/mTOR signaling pathway by reducing the levels of phosphorylation of mTOR pathway components.

Celastrol Induces Apoptosis and Autophagy via the AKT/mTOR Signaling Pathway in the Pituitary ACTH-secreting Adenoma Cells

Objective Pituitary adrenocorticotropic hormone(ACTH)-secreting adenoma is a relatively intractable endocrine adenoma that can cause a range of severe metabolic disorders and pathological changes involving multiple systems.Previous studies have shown that celastrol has antitumor effects on a variety of tumor cells via the AKT/mTOR signaling.However,whether celastrol has pronounced antitumor effects on pituitary ACTH-secreting adenoma is unclear.This study aimed to identify a new effective therapeutic drug for pituitary ACTH-secreting adenoma.Methods Mouse pituitary ACTH-secreting adenoma cells(AtT20 cells)were used as an experimental model in vitro and to establish a xenograft tumor model in mice.Cells and animals were administered doses of celastrol at various levels.The effects of celastrol on cell viability,migration,apoptosis and autophagy were then examined.Finally,the potential involvement of AKT/mTOR signaling in celastrol’s mechanism was assessed.Results Celastrol inhibited the proliferation and migration of pituitary adenoma cells in a time-and concentration-dependent manner.It blocked AtT20 cells in the G0/G1 phase,and induced apoptosis and autophagy by downregulating the AKT/mTOR signaling pathway.Similar results were obtained in mice.Conclusion Celastrol exerts potent antitumor effects on ACTH-secreting adenoma by downregulating the AKT/mTOR signaling in vitro and in vivo.

cPKCγ Deficiency Exacerbates Autophagy Impairment and Hyperphosphorylated Tau Buildup through the AMPK/mTOR Pathway in Mice with Type 1 Diabetes Mellitus

Type 1 diabetes mellitus(T1DM)-induced cognitive dysfunction is common,but its underlying mechanisms are still poorly understood.In this study,we found that knockout of conventional protein kinase C(cPKC)γsignificantly increased the phosphorylation of Tau at Ser214 and neurofibrillary tangles,but did not affect the activities of GSK-3βand PP2A in the hippocampal neurons of T1DM mice.cPKCγdeficiency significantly decreased the level of autophagy in the hippocampal neurons of T1DM mice.Activation of autophagy greatly alleviated the cognitive impairment induced by cPKCγdeficiency in T1DM mice.Moreover,cPKCγdeficiency reduced the AMPK phosphorylation levels and increased the phosphorylation levels of mTOR in vivo and in vitro.The high glucose-induced Tau phosphorylation at Ser214 was further increased by the autophagy inhibitor and was significantly decreased by an mTOR inhibitor.In conclusion,these results indicated that cPKCγpromotes autophagy through the AMPK/mTOR signaling pathway,thus reducing the level of phosphorylated Tau at Ser214 and neurofibrillary tangles.

The role of mTOR signaling pathway in regulating autophagy in liver injury of TX mice with Wilson’s disease

Wilson disease(WD),known as hepatolenticular degeneration(HLD),is a treatable autosomal recessive disorder of copper metabolism.Because copper deposits in the liver first,the liver is not only the original defective organ but also the most affected organ.The liver injury is also one of the main causes of death throughout the course of the disease.Therefore,the treatment of liver injury is the main task of WD treatment,which is of great significance to improve the prognosis of patients.Autophagy is a process that promotes cell survival through degradation,recycling,and absorption in order to maintain the normal physiological function of cells,while excessive autophagy can aggravate cell death.In view of the abnormal damage of liver cells in patients with WD,which may be related to the change of autophagy level,in this study,we established an animal model of WD through toxic milk(TX)mice,observed the change of autophagy level in the liver,and observed the change of liver damage in mice after treatment with autophagy inhibitors.It was found that the mTOR signaling pathway was activated and autophagy was inhibited in Wilson mouse liver.After treatment with rapamycin,the autophagy level of mice liver was upregulated,and the copper content of mice liver was reduced,and the damage was alleviated.TX mouse hepatocytes were isolated,after using siRNA to interfere with mTOR expression,the copper accumulation was significantly reduced,which was the same with RAPA treatment.The results showed that in TX mice,the damage caused by copper accumulation in the liver may be related to the decrease of autophagy level caused by the activation of the mTOR signaling pathway.Our findings suggested that RAPA or the use of siRNA targeting mTOR may have potential applications in the treatment of Wilson’s disease.