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.

Research progress of TCM regulating mTOR signaling pathway in the treatment of Alzheimer's disease

Alzheimer's disease(AD)is a degenerative disease of the central nervous system.The pathogenesis of AD is complex and diverse,and its occurrence and development is the result of the interaction of multiple factors.A number of studies have shown that mTOR signaling pathway is closely related to AD.In recent years,people in exploring relevant methods for the treatment of AD and the process of drugs,more and more studies have found that traditional Chinese medicine compound traditional Chinese medicine monomer,and can be applied to mTOR signaling pathway to improve symptoms in patients with AD.This paper will review the mechanism of action and treatment of TCM in Alzheimer's disease based on mTOR signaling pathway in recent years,so as to provide reference and expand thinking for the prevention and treatment of AD.

基于脂噬介导的mTOR/TFEB信号通路探讨当归红芪超滤物干预糖尿病肾病作用机制

目的以当归红芪超滤物干预糖尿病肾病模型大鼠,探讨其对糖尿病肾病脂噬的效应机制。方法50只SPF级雄性Wistar大鼠随机选取7只为空白组,其余43只采用一次性大剂量腹腔注射链脲佐菌素联合高脂高糖饲料喂养制备糖尿病肾病模型。将成模大鼠随机分为模型组、厄贝沙坦组(17.9 mg/kg)和中药低、中、高剂量组(1.5、3、6g/kg),分别灌胃相应溶液,连续12周。检测大鼠随机血糖、体质量及24h尿蛋白含量,生化检测糖化血清蛋白(GSP)、血肌酐(SCr)、血尿素氮(BUN)、三酰甘油(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、游离脂肪酸(FFA)含量,HE染色观察肾组织形态变化,Masson染色观察肾组织纤维化情况,透射电镜观察肾组织超微结构,RT-qPCR检测肾组织哺乳动物雷帕霉素靶蛋白(mTOR)、微管相关蛋白1轻链3(LC3B)mRNA表达,Westernblot检测肾组织mTOR、转录因子EB(TFEB)、p-TFEB、LC3B蛋白表达。结果与空白组比较,模型组大鼠随机血糖显著升高(P<0.01),体质量显著减少(P<0.01),24h尿蛋白含量显著升高(P<0.01),GSP、SCr、BUN、TG、TC、LDL-C、FFA含量显著升高(P<0.01),HDL-C含量显著降低(P<0.01);肾小管上皮细胞空泡变性、胞质空泡化、有大量炎性细胞浸润,胶原纤维增多且分布杂乱,脂滴数量增加,自噬体数量减少;肾组织mTORmRNA表达显著升高(P<0.01),LC3BmRNA表达显著降低(P<0.01),mTOR、p-TFEB蛋白表达显著升高(P<0.01),TFEB、LC3BⅡ蛋白表达显著降低(P<0.01)。与模型组比较,各给药组大鼠给药12周随机血糖、24h尿蛋白含量降低,体质量增加,GSP、SCr、BUN、TG、TC、LDL-C、FFA含量降低,HDL-C含量升高;肾组织炎性细胞浸润、纤维化、脂滴沉积有不同程度缓解,肾组织mTORmRNA表达降低,LC3BmRNA表达升高,mTOR、p-TFEB蛋白表达降低,TFEB、LC3BⅡ蛋白表达升高,其中厄贝沙坦组和中药高剂量组差异均有统计学意义(P<0.01,P<0.05)。结论当归红芪超滤物能改善糖尿病肾病模型大鼠糖脂代谢紊乱、拮抗肾脏异位脂质沉积、促进脂噬、延缓糖尿病肾病进程,其机制可能与mTOR/TFEB信号通路有关。

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.

Antitumor activity of miR-188-3p in gastric cancer is achieved by targeting CBL expression and inactivating the AKT/mTOR signaling

BACKGROUND Altered miR-188-3p expression has been observed in various human cancers.AIM To investigate the miR-188-3p expression,its roles,and underlying molecular events in gastric cancer.METHODS Fifty gastric cancer and paired normal tissues were collected to analyze miR-188-3p and CBL expression.Normal and gastric cancer cells were used to manipulate miR-188-3p and CBL expression through different assays.The relationship between miR-188-3p and CBL was predicted bioinformatically and confirmed using a luciferase gene reporter assay.A Kaplan-Meier analysis was used to associate miR-188-3p or CBL expression with patient survival.A nude mouse tumor cell xenograft assay was used to confirm the in vitro data.RESULTS MiR-188-3p was found to be lower in the plasma of gastric cancer patients,tissues,and cell lines compared to their healthy counterparts.It was associated with overall survival of gastric cancer patients(P<0.001),tumor differentiation(P<0.001),lymph node metastasis(P=0.033),tumor node metastasis stage(I/II vs III/IV,P=0.024),and American Joint Committee on Cancer stage(I/II vs III/IV,P=0.03).Transfection with miR-188-3p mimics reduced tumor cell growth and invasion while inducing apoptosis and autophagy.CBL was identified as a direct target of miR-188-3p,with its expression antagonizing the effects of miR-188-3p on gastric cancer(GC)cell proliferation by inducing tumor cell apoptosis and autophagy through the inactivation of the Akt/mTOR signaling pathway.The in vivo data confirmed antitumor activity via CBL downregulation in gastric cancer.CONCLUSION The current data provides ex vivo,in vitro,and in vivo evidence that miR-188-3p acts as a tumor suppressor gene or possesses antitumor activity in GC.

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.

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.

Bta-miR-34b controls milk fat biosynthesis via the Akt/mTOR signaling pathway by targeting RAI14 in bovine mammary epithelial cells

Background:The biosynthesis of milk fat affects both the technological properties and organoleptic quality of milk and dairy products.MicroRNAs(miRNAs)are endogenous small non-coding RNAs that inhibit the expression of their mRNA targets and are involved in downstream signaling pathways that control several biological processes,including milk fat synthesis.miR-34b is a member of the miR-34 miRNA cluster,which is differentially expressed in the mammary gland tissue of dairy cows during lactation and dry periods.Previous studies have indicated miR-34b is a potential candidate gene that plays a decisive role in regulating milk fat synthesis;therefore,it is important to focus on miR-34b and investigate its regulatory effect on the biosynthesis of milk fat in bovine mammary epithelial cells(BMECs).Results:In this study,elevated miR-34b levels reduced milk fat synthesis,upregulated 1,999 genes,and downregulated 2,009 genes in BMECs.Moreover,Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis of differentially expressed genes suggested that miR-34b may play an inhibitory role in milk fat synthesis via the protein kinase B(Akt)/mammalian target of rapamycin(mTOR)signaling pathway by reducing phosphorylation levels.Notably,the mTOR activator MHY1485 rescued the inhibitory effect of miR-34b.Furthermore,we demonstrated that retinoic acid-induced protein 14(RAI14)is a target of miR-34b via TargetScan and immunofluorescence assays.RAI14 mRNA and protein levels were significantly decreased by the miR-34b mimic and increased by the miR-34b inhibitor.Moreover,the reduction in RAI14 levels led to the inhibition of the Akt/mTOR signaling pathway.Conclusions:Overall,our results identified a miR-34b-RAI14-Akt/mTOR regulatory network,while also providing a theoretical basis for the molecular breeding of dairy cows.

CircRNA ATF6 promotes ovarian cancer cell progression by activating PTEN/mTOR signaling pathway

Ovarian cancer is a malignant cancer type and affects women’s lives in the world.Circular RNAs(circRNAs)have been involved with the progression of cancers.In our study,we are going to explore the functions of circATF6 in ovarian cancer.The qRT-PCR assay was used to detect expressions of genes.Actinomycin D and RNase R treatment were implemented to verify the circular RNA character of circATF6.Besides,Cell proliferation was assessed by colony formation assay and EdU assay.Silenced circATF6 could reduce the proliferation of ovarian cancer cells.In addition,inhibited circATF6 could promote the cell apoptosis and inhibit related proteins in PTEN/mTOR signaling pathway in ovarian cancer.In conclusion,CircRNA ATF6 promotes ovarian cancer cell progression by activating PTEN/mTOR signaling pathway.

mTOR Signaling Pathway and Its Regulation on Growth and Development

The mammalian target of rapamycin （mTOR） signaling pathway is evolutionarily conserved, mTOR can integrate and converge a wide range of signals, including intracellular and extracellular nutrients, growth factors, energy and stress conditions, and has a crucial role in the vertebrate growth control. This review analyzed the main components and regulated factors of TOR signaling pathway, explained functions and mechanisms of roTOR during the individual growth, the development and its dynamic role, revealed its additional functions beyond the cell growth control, and finally reviewed the tissue specificity and time specificity of mTOR signaling pathway, and its regulation on sexual differentiation, tissue differentiation and organogenesis in the individual development.

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.

Effects of Liancao-Xieli capsule on intestinal mucosal inflammatory factors and TLR4/PI3K/Akt/mTOR signaling pathway in mice with ulcerative colitis

Objective:To observe the effect of Liancao-Xieli capsule on intestinal mucosal inflammatory factors and TLR4/PI3K/Akt/mTOR signaling pathway in mice with ulcerative colitis(UC);Methods:40 male C57BL/6 mice were randomly divided into the control group,model group,Liancao-Xieli group and mesalazine group,with 10 mice in each group.In addition to the control group,the remaining three groups of mice were induced by 3%dextran sulfate sodium(DSS)to induce acute UC model.During the modeling period,mice in each group were given corresponding drugs and normal saline by gavage.At the end of the experiment,HE staining was used to observe the pathological changes of colonic tissue in each group,and ELISA was used to detect the inflammatory factors(TNF-α,IL-6,IL-1β,IL-8,IL-17,and INF-γ)in serum and colonic tissue.The expression levels of TLR4/PI3K/Akt/mTOR signaling pathway related proteins were also detected by Western blot;Results:Compared with the model group,Liancao-Xieli capsule could significantly increase the colon length and decrease the score of colon histopathology in UC mice(P<0.01).In addition,the levels of TNF-α,IL-6,IL1β,IL-8,IL-17,and INF-γwere significantly reduced in serum and colon tissue,and the expressions of TLR4,PI3K,p-Akt and p-mTOR were significantly down-regulated in LiancaoXieyi group when compared with the model group(P<0.01).While the expressions of Akt and mTOR were not significantly affected in Liancao-Xieyi group(P>0.05);Conclusion:LiancaoXieli capsule can reduce the secretion of inflammatory factors,improve the intestinal mucosal damage and inflammatory response in UC by inhibiting the activation of TLR4/PI3K/Akt/mTOR signaling pathway。

How is the AKT/mTOR pathway involved in cell migration and invasion?

As a pathway that plays a role in nutrient absorption,anabolic response,cell growth and survival,the important role of AKT/mTOR in tumorigenesis has also come to light.For cancer patients,most deaths are caused by the growth of metastatic tumors outside the primary focus.Therefore,migration and invasion in the late stage of tumor progression are the main unresolved issues in the study of tumor pathogenesis,and AKT/mTOR has been found to participate in the migration and invasion of cancer cells,which means that the study of this pathway may contribute to a solution for the problem.Because of its extensive and complex functions in the organism,this pathway can be regulated by a variety of different signals in the body,and then realize its function through different downstream signal molecules.This article reviews the proteins that can indirectly affect this pathway by regulating the common upstream signaling molecules of this pathway,and the proteins that can directly affect the level of phosphorylation of AKT/mTOR in cancer cells.We also review the proteins that can co-regulate this pathway and its downstream pathways.Through this study,we hope to gain a deeper understanding of the regulatory mechanism of the AKT/mTOR pathway in cancer cells,in hopes of finding effective and harmless cancer treatment targets in the future.

Regulatory Effects of Zuogui Pill on Apoptosis of Follicles in Rats Injured by 60Co-γRays Based on PI3K/Akt/m TOR Signaling Pathway

[Objectives]To explore the protective effects of Zuogui Pill on ^(60)Co-γ-ray-induced premature aging of rats based on phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/Akt/mTOR)signaling pathway.[Methods]Sixty sexually mature female SD rats were irradiated with ^(60)Co-γ-ray(6.0 Gy,LD 40)for 24 h at one time.These rats were randomly divided into model group,Progynova group[0.18(g·kg)/d],Progynova[0.09(g·kg)/d]+Zuogui Pill high dose[23.625(g·kg)/d)]group,Zuogui Pill high dose[23.625(g·kg)/d)]group,Zuogui Pill medium dose[9.45(g·kg)/d)]group and Zuogui Pill low dose[4.725(g·kg)/d]group.The administration(once a day)lasted 21 d.The rat serum[follicle-stimulating hormone(FSH),luteinizing hormone(LH)and estradiol(E_(2))]were detected by Enzyme-linked immunosorbent assay(ELISA).The morphological changes of ovary were observed by hematoxylin-eosin(HE)staining.The apoptosis rate of granulosa cells was detected by terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick-end labeling(TUNEL).The protein expression of phosphorylated(p)-PI3K,p-Akt,p-mTOR,B-cell lymphoma-2(Bcl-2),and Bcl-2-associated X protein(Bax)in ovarian tissues were detected by Western blot.[Results]Compared with the normal group,the model group showed significant increase in the serum FSH(P<0.01),significant decrease in serum E_(2)(P<0.05),and decrease in the number of early follicles and luteum in the ovary(P<0.01).Besides,the apoptosis rate of granulosa cells increased significantly(P<0.01);the expression of p-PI3K,p-Akt,p-mTOR and Bcl-2 in ovarian tissue decreased significantly,while the expression of Bax increased significantly(P<0.01).Compared with the model group,the number of early follicles in the ovary increased and the apoptosis rate of granulosa cells decreased after intervention in each administration group.In addition,the protein expressions of p-PI3K,p-Akt,p-mTOR and Bcl-2 increased,while the expression of Bax decreased,especially in Progynova+Zuogui Pill high dose group,the differences were statistically significant(P<0.05,P<0.01).[Conclusions]Zuogui Pill may protect the radiation-injured ovary through activating the expression of PI3K/Akt/mTOR protein in ovarian tissue,increasing the amount of Bcl-2 protein and inhibiting the expression of Bax protein.

Biomimetic hydroxyapatite coating on the 3D-printed bioactive porous composite ceramic scaffolds promoted osteogenic differentiation via PI3K/AKT/mTOR signaling pathways and facilitated bone regeneration in vivo

The architecture and surface modifications have been regarded as effective methods to enhance the bi-ological response of biomaterials in bone tissue engineering.The porous architecture of the implanta-tion was essential conditions for bone regeneration.Meanwhile,the design of biomimetic hydroxyap-atite(HAp)coating on porous scaffolds was demonstrated to strengthen the bioactivity and stimulate osteogenesis.However,bioactive bio-ceramics such asβ-tricalcium phosphate(β-TCP)and calcium sili-cate(CS)with superior apatite-forming ability were reported to present better osteogenic activity than that of HAp.Hence in this study,3D-printed interconnected porous bioactive ceramicsβ-TCP/CS scaf-fold was fabricated and the biomimetic HAp apatite coating were constructed in situ via hydrothermal reaction,and the effects of HAp apatite layer on the fate of mouse bone mesenchymal stem cells(mBM-SCs)and the potential mechanisms were explored.The results indicated that HAp apatite coating en-hanced cell proliferation,alkaline phosphatase(ALP)activity,and osteogenic gene expression.Further-more,PI3K/AKT/mTOR signaling pathway is proved to have an important impact on cellular functions.The present results demonstrated that the key molecules of phosphatidylinositol 3-kinase(PI3K),protein kinase B(AKT)and mammalian target of rapamycin(mTOR)were activated after the biomimetic hydrox-yapatite coating were constructed on the 3D-printed ceramic scaffolds.Besides,the activated influence on the protein expression of Runx2 and BMP2 could be suppressed after the treatment of inhibitor HY-10358.In vivo studies showed that the constructed HAp coating promoted bone formation and strengthen the bone quality.These results suggest that biomimetic HAp coating constructed on the 3D-printed bioac-tive composite scaffolds could strengthen the bioactivity and the obtained biomimetic multi-structured scaffolds might be a potential alternative bone graft for bone regeneration.

A new osteogenic protein isolated from Dioscorea opposita Thunb accelerates bone defect healing through the mTOR signaling axis

Delayed bone defect repairs lead to severe health and socioeconomic impacts on patients. Hence, there are increasing demands for medical interventions to promote bone defect healing. Recombinant proteins such as BMP-2 have been recognized as one of the powerful osteogenic substances that promote mesenchymal stem cells (MSCs) to osteoblast differentiation and are widely applied clinically for bone defect repairs. However, recent reports show that BMP-2 treatment has been associated with clinical adverse side effects such as ectopic bone formation, osteolysis and stimulation of inflammation. Here, we have identified one new osteogenic protein, named ‘HKUOT-S2’ protein, from Dioscorea opposita Thunb. Using the bone defect model, we have shown that the HKUOT-S2 protein can accelerate bone defect repair by activating the mTOR signaling axis of MSCs-derived osteoblasts and increasing osteoblastic biomineralization. The HKUOT-S2 protein can also modulate the transcriptomic changes of macrophages, stem cells, and osteoblasts, thereby enhancing the crosstalk between the polarized macrophages and MSCs-osteoblast differentiation to facilitate osteogenesis. Furthermore, this protein had no toxic effects in vivo. We have also identified HKUOT-S2 peptide sequence TKSSLPGQTK as a functional osteogenic unit that can promote osteoblast differentiation in vitro. The HKUOT-S2 protein with robust osteogenic activity could be a potential alternative osteoanabolic agent for promoting osteogenesis and bone defect repairs. We believe that the HKUOT-S2 protein may potentially be applied clinically as a new class of osteogenic agent for bone defect healing.

Novel nervous and multi-system regenerative therapeutic strategies for diabetes mellitus with mTOR

Throughout the globe,diabetes mellitus（DM） is increasing in incidence with limited therapies presently available to prevent or resolve the significant complications of this disorder.DM impacts multiple organs and affects all components of the central and peripheral nervous systems that can range from dementia to diabetic neuropathy.The mechanistic target of rapamycin（m TOR） is a promising agent for the development of novel regenerative strategies for the treatment of DM.m TOR and its related signaling pathways impact multiple metabolic parameters that include cellular metabolic homeostasis,insulin resistance,insulin secretion,stem cell proliferation and differentiation,pancreatic β-cell function,and programmed cell death with apoptosis and autophagy.m TOR is central element for the protein complexes m TOR Complex 1（m TORC1） and m TOR Complex 2（m TORC2） and is a critical component for a number of signaling pathways that involve phosphoinositide 3-kinase（PI 3-K）,protein kinase B（Akt）,AMP activated protein kinase（AMPK）,silent mating type information regulation 2 homolog 1（Saccharomyces cerevisiae）（SIRT1）,Wnt1 inducible signaling pathway protein 1（WISP1）,and growth factors.As a result,m TOR represents an exciting target to offer new clinical avenues for the treatment of DM and the complications of this disease.Future studies directed to elucidate the delicate balance m TOR holds over cellular metabolism and the impact of its broad signaling pathways should foster the translation of these targets into effective clinical regimens for DM.

Role of mammalian target of rapamycin signaling pathway in regulation of fatty acid oxidation in a preeclampsia-like mouse model treated with pravastatin

Background: Fatty acid oxidation (FAO) disorder is involved in the pathogenesis of some cases of preeclampsia (PE). Several show that mammalian target of rapamycin (mTOR) signaling pathway is related to FAO. Pravastatin (Pra) can promote FAO in Nio-nitro-L-arginine methyl ester (L-NAME) PE-like mouse model in our previous study. This study aimed to investigate the effect of mTOR signaling pathway in PE-like model treated with Pra. Methods: Pregnant mice were randomly injected with L-NAME as PE-like model group or saline as control group respectively, from gestational 7th to 18th day. Giving Pra (L-NAME + Pra, Control + Pra, n= 8) or normal saline (NS;L-NAME + NS, Control + NS, n = 8) from gestational 8th to 18th day, the mice were sacrificed on day 18 and their liver and placental tissues were collected. Then the activation of mTOR and its substrates in the liver and placenta were detected. And the association between mTOR activation and mice were randomly injected with L-NAME as PE-like model group or saline as control group respectively, from serum free fatty acid (FFA) levels and the expression of long-chain 3-hydroxyacyl-coenzyme A dehydrogenase (LCHAD) were evaluated using Pearson correlation test. Differences between groups were analyzed using independent t-test or one-way analysis of variance (ANOVA). Results: Both in the maternal liver and placenta, the activation of mTOR protein and its effect on substrates increased significantly in the L-NAME + NS group and decreased significantly in the L-NAME + Pra group. The p-mTOR/mTOR protein ratio decreased in the L-NAME + Pra group significantly than that in the L-NAME + NS group both in liver and placenta (liver: 0.74±0.08 vs. 0.85± 0.06, t=2.95, P<0.05;placenta: 0.63±0.06 vs.0.77±0.06, t=4.64, P<0.05). The activation of mTOR protein in the liver and placenta negatively correlated with the expression of LCHAD in the L-NAME + NS group (liver: r=—0.745, P<0.05;placenta: r=-0.833, P< 0.05) and that in the maternal liver negatively correlated with the expression of LCHAD (r=—0.733, P<0.05) and serum FFA levels positively with the (r=0.841, P< 0.05) in the L-NAME+ Pra group. Conclusion: The inhibition of mTOR signaling pathway might be involved in the regulation of FAO in mouse model treated with Pra.

Emerging agents that target signaling pathways to eradicate colorectal cancer stem cells

Colorectal cancer(CRC)represents the third most commonly diagnosed cancer and the second leading cause of cancer death worldwide.The modern concept of cancer biology indicates that cancer is formed of a small population of cells called cancer stem cells(CSCs),which present both pluripotency and self-renewal properties.These cells are considered responsible for the progression of the disease,recurrence and tumor resistance.Interestingly,some cell signaling pathways participate in CRC survival,proliferation,and selfrenewal properties,and most of them are dysregulated in CSCs,including the Wingless(Wnt)/β-catenin,Notch,Hedgehog,nuclear factor kappa B(NF-κB),Janus kinase/signal transducer and activator of transcription(JAK/STAT),peroxisome proliferator-activated receptor(PPAR),phosphatidyl-inositol-3-kinase/Akt/mechanistic target of rapamycin(PI3K/Akt/mTOR),and transforming growth factor-β(TGF-β)/Smad pathways.In this review,we summarize the strategies for eradicating CRC stem cells by modulating these dysregulated pathways,which will contribute to the study of potential therapeutic schemes,combining conventional drugs with CSC-targeting drugs,and allowing better cure rates in anti-CRC therapy.