Anticancer efficacy of 3-(4-isopropyl)benzylidene-8-ethoxy,6-methyl,chroman-4-one(SBL-060),a novel,dual,estrogen receptor-Akt kinase inhibitor in acute myeloid leukemia cells

Estrogen receptor(ER)αis expressed in a subset of patient-derived acute myeloid leukemia(AML)cells,whereas Akt is predominantly expressed in most types of AML.Targeting AML with dual inhibitors is a novel approach to combat the disease.Herein,we examined a novel small molecule,3-(4-isopropyl)benzylidene-8-ethoxy,6-methyl,chroman-4-one(SBL-060),capable of targeting AML cells by inhibiting ERαand Akt kinase.The chemical properties of SBL-060 were identified by proton nuclear magnetic resonance(^(1)H-NMR),^(13)C-NMR,and mass spectroscopy.In silico docking was performed using an automated protocol with AutoDock-VINA.THP-1 and HL-60 cell lines were differentiated using phorbol 12-myristate 13-acetate.ERαinhibition was assessed using ELISA.The MTT assay assessed cell viability.Flow cytometry was performed for cell cycle,apoptosis,and p-Akt analyses.Chemical analysis identified the compound as 3-(4-isopropyl)benzylidene-8-ethoxy,6-methyl,chroman-4-one,which showed high binding efficacy toward ER,with aΔG_(binding) score of−7.4 kcal/mol.SBL-060 inhibited ERα,exhibiting IC50 values of 448 and 374.3 nM in THP-1 and HL-60 cells,respectively.Regarding inhibited cell proliferation,GI50 values of SBL-060 were 244.1 and 189.9 nM for THP-1 and HL-60 cells,respectively.In addition,a dose-dependent increase in sub G_(0)/G_(1) phase cell cycle arrest and total apoptosis was observed after treatment with SBL-060 in both cell types.SBL-060 also dose-dependently increased the p-Akt-positive populations in both THP-1 and HL-60 cells.Our results indicate that SBL-060 has excellent efficacy against differentiated AML cell types by inhibiting ER and Akt kinase,warranting further preclinical evaluations.

Mechanism of stilbene glycosides on apoptosis of SH-SY5Y cells via regulating PI3K/AKT signaling pathway

Objective:To investigate the effects of stilbene glycoside(TSG)on okadaic acid-induced apoptosis in human neuroblastoma cells(SH-SY5Y)via the PI3K/AKT pathway.Methods:The optimal concentration of OA was screened by CCK-8 assay,and SH-SY5Y cells were divided into control group,model group,TSG group,LY294002 group and LY294002+TSG group.The proliferation and apoptosis in each group were detected by CCK-8 and TUNEL assays;Western blotting method and real-time fluorescence quantitative polymerase chain reaction was used to detect the expression of PI3K,P-PI3K(Y607),AKT,P-AKT(Ser473),Bcl-2 and Bax proteins.The relative protein expression was represented by P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT and Bcl-2/Bax gray ratio.Results:CCK-8 screened the optimal concentration of OA as 40 nmol/L.Compared with the control group,the model group increased relative cell viability,decreased apoptosis rate,the pathway and apoptotic proteins expression levels of P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT and Bcl-2/Bax were decreased,and the mRNA expression levels of PI3K,AKT and Bcl-2 were decreased.Bax mRNA expression level increased(P<0.05);Compared with model group,TSG group increased relative cell viability,decreased apoptosis rate,increased protein expression levels of P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT,Bcl-2/Bax,and increased mRNA expression levels of PI3K,AKT,and Bcl-2.Bax mRNA expression decreased(P<0.05),LY294002 group decreased relative cell viability,increased apoptosis rate,P-PI3K(Y607)/PI3K protein expression levels were significantly decreased(P<0.05),P-AKT(Ser473)/AKT and Bcl-2/Bax protein expression levels were significantly decreased,but there was no statistical significance,PI3K,AKT and Bcl-2 mRNA expression levels were decreased,and Bax mRNA expression levels were increased(all P<0.05);Compared with LY294002 group,LY294002+TSG group increased relative cell viability,decreased apoptosis rate,and the protein expression levels of P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT and Bcl-2/Bax were increased.The mRNA expression levels of PI3K,AKT,Bcl-2 were increased,Bax was decreased(all P<0.05).Conclusion:Stilbene glycoside may alleviate okadaic acid-induced apoptosis in SH-SY5Y cells by interfering with the PI3K/AKT signaling pathway,which in turn regulates the expression of apoptotic factors such as Bcl-2 and Bax.

Role of Akt signaling in resistance to DNA-targeted therapy

The Akt signal transduction pathway controls most hallmarks of cancer. Activation of the Akt cascade promotes a malignant phenotype and is also widely implicated in drug resistance. Therefore, the modulation of Akt activity is regarded as an attractive strategy to enhance the efficacy of cancer therapy and irradiation. This pathway consists of phosphatidylinositol 3 kinase(PI3K), mammalian target of rapamycin, and the transforming serine-threonine kinase Akt protein isoforms, also known as protein kinase B. DNA-targeted agents, such as platinum agents, taxanes, and antimetabolites, as well as radiation have had a significant impact on cancer treatment by affecting DNA replication, which is aberrantly activated in malignancies. However, the caveat is that they may also trigger the activation of repairing mechanisms, such as upstream and downstream cascade of Akt survival pathway. Thus, each target can theoretically be inhibited in view of improving the potency of conventional treatment. Akt inhibitors, e.g., MK-2206 and perifosine, or PI3K modulators, e.g., LY294002 and Wortmannin, have shown some promising results in favor of sensitizing the cancer cells to the therapy in vitro and in vivo, which have provided the rationale for incorporation of these novel agents into multimodality treatment of different malignancies. Nevertheless, despite the acceptable safety profile of some of these agents in the clinical studies, with regard to the efficacy, the results are still too preliminary. Hence, we need to wait for the upcoming data from the ongoing trials before utilizing them into the standard care of cancer patients.

PI3K/Akt/mTOR inhibitors in breast cancer

Activation of the phosphoinositide 3 kinase(PI3K)/Akt/mammalian target of rapamycin(mTOR) pathway is common in breast cancer. There is preclinical data to support inhibition of the pathway, and phase Ⅰ to Ⅲ trials involving inhibitors of the pathway have been or are being conducted in solid tumors and breast cancer. Everolimus, an mTOR inhibitor, is currently approved for the treatment of hormone receptor(HR)-positive, human epidermal growth factor receptor 2(HER2)-negative breast cancer. In this review, we summarise the efficacy and toxicity findings from the randomised clinical trials, with simplified guidelines on the management of potential adverse effects. Education of healthcare professionals and patients is critical for safety and compliance. While there is some clinical evidence of activity of mTOR inhibition in HR-positive and HER2-positive breast cancers, the benefits may be more pronounced in selected subsets rather than in the overall population. Further development of predictive biomarkers will be useful in the selection of patients who will benefit from inhibition of the PI3K/Akt/mTOR(PAM) pathway.

Insensitivity of PI3K/Akt/GSK3 signaling in peripheral blood mononuclear cells of age-related macular degeneration patients

Our recent studies with cultured retinal pigment epithelium cells suggested that overexpression of interleukin 17 receptor C（IL-17RC）,a phenomenon observed in peripheral blood and chorioretinal tissues with age-related macular degeneration（AMD）,was associated with altered activation of phosphatidylinositide 3-kinase（PI3K）,Akt,and glycogen synthase kinase 3（GSK3）.We wondered whether or not altered PI3 K,Akt,and GSK3 activities could be detected in peripheral blood mononuclear cells（PBMC） obtained from AMD patients.In the patients＇ PBMC,absent or reduced serine-phosphorylation of GSK3α or GSK3β was observed,which was accompanied with increased phosphorylation of GSK3 substrates（e.g.CCAAT enhancer binding protein a,insulin receptor substrate 1,and TAU）,indicative of enhanced GSK3 activation.In addition,decreased protein mass of PI3K85α and tyrosinephosphorylation of PI3K50α was present in PBMC of the AMD patients,suggesting impaired PI3 K activation.Moreover,abnormally lowered molecular weight forms of Akt and GSK3 were detected in PBMC of the AMD patients.These data demonstrate that despite the presence of high levels of IL-17 RC,Wnt-3a and vascular endothelial growth factor,the PI3K/Akt/GSK3 signaling pathway is insensitive to these stimuli in PBMC of the AMD patients.Thus,measurement of PI3K/Akt/GSK3 expression and activity in PBMC may serve as a surrogate biomarker for AMD.

OVEREXPRESSION OF Akt-1 GENE IN HUMAN HEPATOCELLULAR CARCINOMA

Objective: To investigate the expression difference of protein kinase B/Akt (Akt-1) between hepatocellular carcinoma (HCC) and adjacent normal liver tissues through the use of semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Northern blot. Methods: RT-PCR of 24 pairs of specimens and Northern blot of 4 pairs of specimens were performed to investigate the expression of Akt-1. Results: Akt-1 gene was overexpressed in 15 of 24 HCC (63.3%) by RT-PCR and in all HCC (4 paired tissues) by Northern blot. Conclusion: Akt-1 activation may play a role in the pathogenesis and progression of HCC. Akt-1 gene is reported to have changed in HCC for the first time. The precise relationship between Akt-1 and HCC is a matter of further investigation.

Tongxinluo Activates PI3K/AKT Signaling Pathway to Inhibit Endothelial Mesenchymal Transition and Attenuate Myocardial Fibrosis after Ischemia-Reperfusion in Mice

Objective To investigate the potential role of Tongxinluo(TXL)in attenuating myocardial fibrosis after myocardial ischemia-reperfusion injury(MIRI)in mice.Methods A MIRI mouse model was established by left anterior descending coronary artery ligation for 45 min.According to a random number table,66 mice were randomly divided into 6 groups(n=11 per group):the sham group,the model group,the LY-294002 group,the TXL group,the TXL+LY-294002 group and the benazepril(BNPL)group.The day after modeling,TXL and BNPL were administered by gavage.Intraperitoneal injection of LY-294002 was performed twice a week for 4 consecutive weeks.Echocardiography was used to measure cardiac function in mice.Masson staining was used to evaluate the degree of myocardial fibrosis in mice.Qualitative and quantitative analysis of endothelial mesenchymal transition(EndMT)after MIRI was performed by immunohistochemistry,immunofluorescence staining and flow cytometry,respectively.The protein expressions of platelet endothelial cell adhesion molecule-1(CD31),α-smoth muscle actin(α-SMA),phosphatidylinositol-3-kinase(PI3K)and phospho protein kinase B(p-AKT)were assessed using Western blot.Results TXL improved cardiac function in MIRI mice,reduced the degree of myocardial fibrosis,increased the expression of CD31 and inhibited the expression ofα-SMA,thus inhibited the occurrence of EndMT(P<0.05 or P<0.01).TXL significantly increased the protein expressions of PI3K and p-AKT(P<0.05 or P<0.01).There was no significant difference between TXL and BNPL group(P>0.05).In addition,the use of the PI3K/AKT pathway-specific inhibitor LY-294002 to block this pathway and combination with TXL intervention,eliminated the protective effect of TXL,further supporting the protective effect of TXL.Conclusion TXL activated the PI3K/AKT signaling pathway to inhibit EndMT and attenuated myocardial fibrosis after MIRI in mice.

Piezoelectric film promotes skin wound healing with enhanced collagen deposition and vessels regeneration via upregulation of PI3K/AKT

Skin wounds are common in accidental injuries,and the intricacies of wound repair are closely linked to endogenous electric fields.Electrical stimulation plays a pivotal role in the restorative processes of skin injuries,encompassing collagen deposition,angiogenesis,inflammation,and re-epithelialization.Employing electrical stimulation therapy replicates and enhances the effects of endogenous wound electric fields by applying an external electric field to the wound site,thereby promoting skin wound healing.In this study,we developed a self-powered repetitive mechanical impacts-electrical stimulation(RMI-ES)system utilizing a BaTiO_(3)/polydimethylsiloxane(PDMS)piezoelectric composite film.Compared to conventional electrical stimulation devices,the fabricated piezoelectric composite film efficiently harvests energy from the pressure applied by the stimulation device and the tensile force occurring during natural rat activities.The results demonstrated that piezoelectric stimulation generated by the composite membrane expedited the cell cycle,promoting fibroblast proliferation.Additionally,piezoelectric stimulation induced favorable changes in fibroblast gene expression,including increased expression of transforming growth factor-β1(TGF-β1),connective tissue growth factor(CTGF),collagen 1,collagen 3,vascular endothelial growth factor(VEGF),and alpha-smooth muscle actin(α-SMA),while reducing interleukin-6(IL-6)expression.Transcriptome analysis revealed that piezoelectric stimulation may induce fibroblast migration,proliferation,and collagen expression by influencing PI3K/AKT serine/threonine kinase(AKT)pathways.Further confirmation through the addition of the PI3K inhibitor LY294002 validated that piezoelectric stimulation can regulate the repair process after skin injury through the pathway.Importantly,in vivo results demonstrated that the electric field at the wound site effectively promoted wound healing,reduced inflammation,and stimulated collagen deposition and neovascularization.This study emphasizes the role of the piezoelectric membrane as an effective,safe,and battery-free electrical stimulator crucial for skin wound healing.

Roles of THEM4 in the Akt pathway:a double-edged sword

The protein kinase B(Akt)pathway can regulate the growth,proliferation,and metabolism of tumor cells and stem cells through the activation of multiple downstream target genes,thus affecting the development and treatment of a range of diseases.thioesterase superfamily member 4(THEM4),a member of the thioesterase superfamily,is one of the Akt kinase-binding proteins.Some studies on the mechanism of cancers and other diseases have shown that THEM4 binds to Akt to regulate its phosphorylation.Initially,THEM4 was considered an endogenous inhibitor of Akt,which can inhibit the phosphorylation of Akt in diseases such as lung cancer,pancreatic cancer,and liver cancer,but subsequently,THEM4 was shown to promote the proliferation of tumor cells by positively regulating Akt activity in breast cancer and nasopharyngeal carcinoma,which contradicts previous findings.Considering these two distinct views,this review summarizes the important roles of THEM4 in the Akt pathway,focusing on THEM4 as an Akt-binding protein and its regulatory relationship with Akt phosphorylation in various diseases,especially cancer.This work provides a better understanding of the roles of THEM4 combined with Akt in the treatment of diseases.

Liposomalα-cyperone targeting bone resorption surfaces suppresses osteoclast differentiation and osteoporosis progression via the PI3K/Akt axis

Osteoporosis is a metabolic dysregulation of bone that occurs mainly in postmenopausal women,and the hyperfunction of osteoclasts is the primary contributor to postmenopausal osteoporosis.However,the development of effective therapeutic drugs and precise delivery systems remains a challenge in the field of anti-absorption therapy.Here,we reported theα-cyperone(α-CYP)for anti-osteoporosis and developed a liposome-based nano-drug delivery system ofα-CYP,that specifically targets the bone resorption interface.Firstly,we found that theα-CYP,one of the major sesquiterpenes of Cyperus rotundus L.,attenuated the progression of osteoporosis in ovariectomized(OVX)mice and down-regulated the expression of phosphorylated proteins of phosphoinositide 3-kinase(PI3K)and protein kinase B(Akt),causing down-regulation of osteoclast-related genes/proteins and curbing osteoclast differentiation.Furthermore,α-CYP reversed the activation of osteoclastic differentiation and enhanced osteoporosis-related proteins expression caused by PI3K/Akt agonist(YS-49).More importantly,we adopted the osteoclastic resorption surface targeting peptide Asp8 and constructed the liposome(lipαC@Asp8)to deliverα-CYP to osteoclasts and confirmed its anti-osteoporosis effect and enhanced osteoclast inhibition by blocking PI3K/Akt axis.In conclusion,this study demonstrated thatα-CYP inhibits osteoclast differentiation and osteoporosis development by silencing PI3K/Akt pathway,and the liposome targeting delivery systems loaded withα-CYP might provide a novel and effective strategy to treat osteoporosis.

Sorafenib inhibits growth and metastasis of hepatocellular carcinoma by blocking STAT3

AIM: To investigate the inhibitory role and the underlying mechanisms of sorafenib on signal transducer and activator of transcription 3 (STAT3) activity in hepatocellular carcinoma (HCC).METHODS: Human and rat HCC cell lines were treated with sorafenib. Proliferation and STAT3 dephosphorylation were assessed. Potential molecular mechanisms of STAT3 pathway inhibition by sorafenib were evaluated. In vivo antitumor action and STAT3 inhibition were investigated in an immunocompetent orthotopic rat HCC model.RESULTS: Sorafenib decreased STAT3 phosphorylationat the tyrosine and serine residues (Y705 and S727), but did not affect Janus kinase 2 (JAK2) and phosphatase shatterproof 2 (SHP2), which is associated with growth inhibition in HCC cells. Dephosphorylation of S727 was associated with attenuated extracellular signal-regulated kinase (ERK) phosphorylation, similar to the effects of a mitogen-activated protein kinase (MEK) inhibitor U0126, suggesting that sorafenib induced S727 dephosphorylation by inhibiting MEK/ERK signaling. Meanwhile, sorafenib could also inhibit Akt phosphorylation, and both the phosphatidylinositol-3-kinase (PI3K) inhibitor LY294002 and Akt knockdown resulted in Y705 dephosphorylation, indicating that Y705 dephosphorylation by sorafenib was mediated by inhibiting the PI3K/Akt pathway. Finally, in the rat HCC model, sorafenib signifi cantly inhibited STAT3 activity, reducing tumor growth and metastasis.CONCLUSION: Sorafenib inhibits growth and metastasis of HCC in part by blocking the MEK/ERK/STAT3 and PI3K/Akt/STAT3 signaling pathways, but independent of JAK2 and SHP2 activation.

Mechanism Prediction of Monotropein for the Treatment of Colorectal Cancer by Network Pharmacology Analysis

Objective To discover the pharmacological mechanisms of monotropein in colorectal cancer by network pharmacology methods.Methods The main-candidate-target network was constructed by the prediction of targets of monotropein, collection of therapeutic targets of colorectal cancer drugs, and construction of the target network and layers of screening. The data were interpreted by pathway enrichment and target score calculation.Results This study:(1) Demonstrated the potential of monotropein to be a multi-target drug against colorectal cancer using a computational approach;(2) Discovered 10 candidate targets of monotropein, among which protein kinase B(AKT1)exhibited the highest relevance and importance to colorectal cancer and proto-oncogene tyrosine-protein kinase Src(SRC),Bruton’s tyrosine kinase(BTK), and heat shock protein HSP 90-alpha(HSP90 AA1) also exhibited high relevance;(3) Observed 32 possible pathways related to the effects of monotropein on colorectal cancer, which might explain the mechanism of its action;and(4) Established a method to assess the importance of targets in the network.Conclusions This study offered clues for the mechanism of the bioactivities of monotropein against colorectal cancer by network analysis. Monotropein has the potential to be a multi-target drug against colorectal cancer, which lays the foundation for its clinical applications and further study.

AB020.Inhibition of cyclic-AMP-response element binding protein and its impact on corneal wound healing in vitro and in vivo

Background:The cornea composes the outer surface of the eye and its transparency is required to allow light transmission to the retina.However,because of its position,the cornea is subjected to chemical and mechanical injuries that may lead to blindness.Our studies conducted using the human tissue-engineered cornea(hTEC)as a model provided evidence that the cyclic-AMP-response element binding protein(CREB)pathway is repressed during closure of corneal wounds.Based on these results,we hypothesized that closure of corneal wounds can be enhanced by preventing activation of CREB with the pharmacological inhibitor C646.Our goals were to proceed to the pharmacological inhibition of CREB(I)in vitro using the hTECs as a model,and then(II)in vivo using the rabbit as a model.Methods:The self-assembly approach was used to create hTECs,that were then wounded with an 8-mm diameter biopsy punch to create an epithelial defect.The tissues were then incubated with 10μM of C646(n=8).DMSO was used alone as a negative control(n=4).Closure of the wounds was monitored over a period of 5 days.Besides,the cornea of New Zealand white rabbits was debrided with an ethanol 70%solution to create an epithelial defect of 8-mm diameter.Several concentrations of C646(1,10,100μM et 1 mM)were applied as eye drops 3 times a day for up to 7 days.The wounded corneas(n=4 per concentration)were stained with fluorescein and photographed every day.Results:In vitro pharmacological inhibition of CREB with C646 considerably accelerated wound closure of all treated hTECs(4 days)compared to the control group(7 days).Moreover,the in vivo C646 treatment also accelerated wound healing of the corneas compared to the control group.The most effective concentration of C646 tested was the lowest(1μM),as it considerably enhanced the wound healing process.Conclusions:This study demonstrates that wound healing both in vitro and in vivo can be enhanced by preventing activation of CREB using a pharmacological inhibition approach.Most of all,this experiment suggests mediators from the CREB pathway as potential therapeutic targets on which we may influence to alter the wound healing dynamic of the cornea.We believe this study will lead to significant advancements in the clinical field of corneal defects.

Integrative analyses identified gap junction beta‐2 as a prognostic biomarker and therapeutic target for breast cancer

Background:Increasing evidence has shown that connexins are involved in the regulation of tumor development,immune escape,and drug resistance.This study investigated the gene expression patterns,prognostic values,and potential mechanisms of connexins in breast cancer.Methods:We conducted a comprehensive analysis of connexins using public gene and protein expression databases and clinical samples from our institution.Connexin mRNA expressions in breast cancer and matched normal tissues were compared,and multiomics studies were performed.Results:Gap junction beta‐2 mRNA was overexpressed in breast cancers of different pathological types and molecular subtypes,and its high expression was associated with poor prognosis.The tumor membrane of the gap junction beta‐2 mutated group was positive,and the corresponding protein was expressed.Somatic mutation and copy number variation of gap junction beta‐2 are rare in breast cancer.The gap junction beta‐2 transcription level in the p110αsubunit of the phosphoinositide 3‐kinase mutant subgroup was higher than that in the wild‐type subgroup.Gap junction beta‐2 was associated with the phosphoinositide 3‐kinase‐Akt signaling pathway,extracellular matrix–receptor interaction,focal adhesion,and proteoglycans in cancer.Furthermore,gap junction beta‐2 overexpression may be associated with phosphoinositide 3‐kinase and histone deacetylase inhibitor resistance,and its expression level correlated with infiltrating CD8+T cells,macrophages,neutrophils,and dendritic cells.Conclusions:Gap junction beta‐2 may be a promising therapeutic target for targeted therapy and immunotherapy and may be used to predict breast cancer prognosis.

Prohibitin(PHB)interacts with AKT in mitochondria to coordinately modulate sperm motility

Prohibitin(PHB),an evoluti on arily con served mitochondrial inner membra ne protein,is highly expressed in cells that require strong mitoch on drial function.Recently,we dem on strated that the deleti on of Phb in spermatocytes results in impaired mitochondrial function.In addition,PHB expression in the mitochondrial sheath of human sperm has a significantly negative correlation with mitochondrial reactive oxygen species levels,but a positive one with mitochondrial membrane potential and sperm motility.These results suggest that mitochondrial PHB expression plays a role in sperm motility.However,the mechanism of PHB-mediated regulation of sperm motility remai ns unk nown.Here,we dem on strate for the first time that PHB interacts with protei n kinase B(AKT)and exists in a complex with phospho-PHB(pT258)and phospho-AKT in the mitochondrial sheath of murine sperm,as determined using colocalization and coimmunoprecipitation assays.After blocking AKT activity using wortmannin(a phosphatidylinositol 3-kinase[PI3K]inhibitor),murine sperm have significantly(P<0.05)decreased levels of phospho-PHB(pT258)and the total and progressive motility.Furthermore,significantly(P<0.05)lower levels of phospho-PI3K P85 subunit a+γ(pY199 and pY46)and phospho-AKT(pS473;pT308)are found in sperm from infertile asthenospermic and oligoasthenospermic men compared with no rmospermic subjects,which suggest a reduced activity of the PI3K/AKT pathway in these in fertile subjects.Importantly,these sperm from infertile subjects also have a significantly(P<0.05)lower level of phospho-PHB(pT258).Collectively,our findings suggest that the interaction of PHB with AKT in the mitochondrial sheath is critical for sperm motility,where PHB phosphorylation(pT258)level and PI3K/AKT activity are key regulatory factors.

Contribution of the Akt2 gene to type 2 diabetes in the Chinese Han population

Background The Akt2 protein kinase is thought to be a key mediator of the insulin signal transduction process. Akt2 is suggested to play a role in glucose metabolism and the development or maintenance of proper adipose tissue and islet mass. In order to determine whether the Akt2 gene plays a role in the pathogenesis of type 2 diabetes characterized by insulin resistance, and to further identify if variations in this gene have a relationship with type 2 diabetes, we sequenced the entire coding region and splice junctions of Akt2 and made a further case-control study to explore the association between sinclle-nucleotide polvmorphisms （SNPs） in this Qene and type 2 diabetes in the Chinese Han population.Methods We selected 23 probands with a type 2 diabetic pedigree whose family members＇ average onset age was within 25 to 45 years old. The body mass index of all the participants was lower than 28 kg/m2 and all of them were insulin-resistant （the fasting insulin level 〉100 pmol/L or 16 μlU/ml）. The entire coding region and splice junctions of Akt2 were directly sequenced in these 23 probands, SNPs with a frequency of minor allele over 20 percent were selected to be further studied in a case-control study, We chose 743 non-diabetic subjects as the control group and 742 type 2 diabetic patients as the case group, All these subjects were genotyped. A Snapshot Technology Platform （Applied Biosystems） was used for genotyping.Results The Akt2 genes from all 23 subjects were successfully sequenced. We did not identify any mutation in the type 2 diabetic pedigree. Two SNPs were identified, 13010323T〉C and 13007939G〉T. 13010323T〉C was in intron 9, which was the location of rs2304188 reported in Genbank. Its minor allele frequency was 13.04%. 13007939G〉T was in the 3＇-untranslated region （UTR） of exon 14, which was the location of rs2304186 reported in Genbank. Its minor allele frequency was 34.78%. The allele frequency of rs2304188 and rs2304186 were consistent with the frequency reported in Genbank. In the case-control study with 742 patients and 743 controls, there was no significant difference between the two qroups for the allele frequency of rs2304186 （odd ratio： 0.96, 95% confidence interval： 0.82-1.12, P=0.597）.Conclusions The Akt2 gene is not a major cause of diabetes in a non-obese Chinese Han population characterized by insulin resistance. There is no significant relationship between rs2304186 and type 2 diabetes in the Chinese Han population.

Heat shock protein 90 protects rat mesenchymal stem cells against hypoxia and serum deprivation-induced apoptosis via the PI3K/Akt and ERK1/2 pathways

Mesenchymal stem cell （MSC） transplantation has shown a therapeutic potential to repair the ischemic and infracted myocardium, but the effects are limited by the apoptosis and loss of donor cells in host cardiac microenvironment. The aim of this study is to explore the cytoprotection of heat shock protein 90 （Hsp90） against hypoxia and serum deprivation-induced apoptosis and the possible mechanisms in rat MSCs. Cell viability was determined by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay. Apoptosis was assessed by Hoechst 33258 nuclear staining and flow cytometric analysis with annexin V/PI staining. The gene expression of Toll-like receptor-4 （TLR-4） and V-erb-b2 erythroblastic leukemia viral oncogene homolog 2 （ErbB2） was detected by real-time poly- merase chain reaction （PCR）. The protein levels of cleaved caspase-3, Bcl-2, Bcl-xL, Bax, totaI-ERK, phospho-ERK, totaI-Akt, phospho-Akt, and Hsp90 were detected by Western blot. The production of nitric oxide was measured by spectrophotometric assay. Hsp90 improves MSC viability and protects MSCs against apoptosis induced by serum deprivation and hypoxia. The protective role of Hsp90 not only elevates Bcl-2/Bax and Bcl-xL/Bax expression and attenuates cleaved caspase-3 expression via down-regulating membrane TLR-4 and ErbB2 receptors and then ac- tivating their downstream PI3K/Akt and ERK1/2 pathways, but also enhances the paracrine effect of MSCs. These findings demonstrated a novel and effective treatment strategy against MSC apoptosis in cell transplantation.

Effect of Palrnatine on lipopolysaccharide-induced acute lung injury by inhibiting activation of the Akt/NF-κB pathway

Inflammation plays an important role in the development of acute lung injury(ALI).Severe pulmonary inflammation can cause acute respiratory distress syndrome(ARDS)or even death.Expression of proinflammatory interleukin-1β(IL-1β)and inducible nitric oxide synthase(iNOS)in the process of pulmonary inflammation will further exacerbate the severity of ALI.The purpose of this study was to explore the effect of Palrnatine(Pa)on lipopolysaccharide(LPS)-induced mouse ALI and its underlying mechanism.Pa,a natural product,has a wide range of pharmacological activities with the potential to protect against lung injury.Western blotting and quantitative real-time polymerase chain reaction(qRT-PCR)assays were performed to detect the expression and translation of inflammatory genes and proteins in vitro and in vivo.Immunoprecipitation was used to detect the degree of P65 translocation into the nucleus.We also used molecular modeling to further clarify the mechanism of action.The results showed that Pa pretreatment could significantly inhibit the expression and secretion of the inflammatory cytokine IL-1β,and significantly reduce the protein level of the proinflammatory protease iNOS,in both in vivo and in vitro models induced by LPS.Further mechanism studies showed that Pa could significantly inhibit the activation of the protein kinase B(Akt)/nuclear factor-κB(NF-κB)signaling pathway in the LPS-induced ALI mode and in LPS-induced RAW264.7 cells.Through molecular dynamics simulation,we observed that Pa was bound to the catalytic pocket of Akt and effectively inhibited the biological activity of Akt.These results indicated that Pa significantly relieves LPS-induced ALI by activating the Akt/NF-κB signaling pathway.

Signaling mechanisms regulating myelination in the central nervous system

The precise and coordinated production of myelin is essential for proper development and function of the nervous system. Diseases that disrupt myelin, including multiple sclerosis, cause significant functional disability. Current treatment aims to reduce the inflammatory component of the disease, thereby preventing damage resulting from demyelination. However, therapies are not yet available to improve natural repair processes after damage has already occurred. A thorough understanding of the signaling mechanisms that regulate myelin generation will improve our ability to enhance repair. In this review, we summarize the positive and negative regulators of myelination, focusing primarily on central nervous system myelination. Axon-derived signals, extracellular signals from both diffusible factors and the extracellular matrix, and intracellular signaling pathways within myelinating oligodendrocytes are discussed. Much is known about the positive regulators that drive myelination, while less is known about the negative regulators that shift active myelination to myelin maintenance at the appropriate time. Therefore, we also provide new data on potential negative regulators of CNS myelination.

淫羊藿素对多囊卵巢综合征颗粒细胞凋亡和自噬的影响

目的基于磷脂酰肌醇-3激酶(Phospoinositide 3-kinase,PI3K)/蛋白激酶B(protein kinase B,Akt)通路探讨淫羊藿素对多囊卵巢综合征颗粒细胞凋亡和自噬的影响。方法分离多囊卵巢综合征大鼠卵巢颗粒细胞,分成对照组、低、中、高剂量实验组(15,30,60μmol·L^(-1)淫羊藿素)和抑制剂组(60μmol·L^(-1)淫羊藿素和PI3K/Akt通路抑制剂LY294002处理)。以蛋白质印迹法检测PI3K/Akt通路关键蛋白、凋亡相关蛋白B细胞淋巴瘤/白血病-2(B cell lymphoma/lewkmia-2,Bcl-2)、Bcl-2相关X蛋白(Bcl-2 associated X protein,Bax)和自噬相关蛋白Beclin1、LC3Ⅱ/LC3Ⅰ表达变化,以细胞计数法-8(CCK-8)实验测定细胞增殖活性,以流式细胞术测定细胞凋亡。结果对照组、低、中、高剂量实验组和抑制剂组细胞增殖活性(OD值)分别为0.41±0.05、0.63±0.06、0.75±0.08、0.88±0.06、0.69±0.06,LC3Ⅱ/LC3Ⅰ表达量分别为1.76±0.15、1.45±0.11、1.12±0.07、1.05±0.09、1.32±0.13,细胞凋亡率分别为(42.65±6.32)%,(37.01±3.24)%,(26.47±2.11)%,(19.84±1.40)%,(35.12±0.30)%,p-PI3K表达量分别为0.35±0.05,0.48±0.05,0.68±0.07,0.89±0.09,0.41±0.06,PI3K表达量分别为0.94±0.11,0.94±0.09,0.92±0.11,0.87±0.12,0.90±0.09,以上指标,对照组与低、中、高剂量实验组比较,差异均有统计学意义(均P<0.05);低、中、高剂量实验组间比较,差异均有统计学意义(均P<0.05);高剂量实验组与抑制剂组比较,差异均有统计学意义(P<0.05)。结论淫羊藿素通过激活PI3K/Akt通路抑制多囊卵巢综合征颗粒细胞凋亡和自噬。