Timosaponin AⅢ induces drug-metabolizing enzymes by activating constitutive androstane receptor (CAR) via dephosphorylation of the EGFR signaling pathway

The current study aimed to assess the effect of timosaponin AⅢ(T-AⅢ)on drug-metabolizing enzymes during anticancer therapy.The in vivo experiments were conducted on nude and ICR mice.Following a 24-day administration of T-AⅢ,the nude mice exhibited an induction of CYP2B10,MDR1,and CYP3A11 expression in the liver tissues.In the ICR mice,the expression levels of CYP2B10 and MDR1 increased after a three-day T-AⅢ administration.The in vitro assessments with HepG2 cells revealed that T-AⅢ induced the expression of CYP2B6,MDR1,and CYP3A4,along with constitutive androstane receptor(CAR)activation.Treatment with CAR siRNA reversed the T-AⅢ-induced increases in CYP2B6 and CYP3A4 expression.Furthermore,other CAR target genes also showed a significant increase in the expression.The up-regulation of murine CAR was observed in the liver tissues of both nude and ICR mice.Subsequent findings demonstrated that T-AⅢ activated CAR by inhibiting ERK1/2 phosphorylation,with this effect being partially reversed by the ERK activator t-BHQ.Inhibition of the ERK1/2 signaling pathway was also observed in vivo.Additionally,T-AⅢ inhibited the phosphorylation of EGFR at Tyr1173 and Tyr845,and suppressed EGF-induced phosphorylation of EGFR,ERK,and CAR.In the nude mice,T-AⅢ also inhibited EGFR phosphorylation.These results collectively indicate that T-AⅢ is a novel CAR activator through inhibition of the EGFR pathway.

Acupuncture at Back-Shu point improves insomnia by reducing inflammation and inhibiting the ERK/NF-κB signaling pathway

BACKGROUND Insomnia is a disease where individuals cannot maintain a steady and stable sleep state or fail to fall asleep.Western medicine mainly uses sedatives and hypnotic drugs to treat insomnia,and long-term use is prone to drug resistance and other adverse reactions.Acupuncture has a good curative effect and unique advantages in the treatment of insomnia.AIM To explore the molecular mechanism of acupuncture at Back-Shu point for the treatment of insomnia.METHODS We first prepared a rat model of insomnia,and then carried out acupuncture for 7 consecutive days.After treatment,the sleep time and general behavior of the rats were determined.The Morris water maze test was used to assess the learning ability and spatial memory ability of the rats.The expression levels of inflammatory cytokines in serum and the hippocampus were detected by ELISA.qRTPCR was used to detect the mRNA expression changes in the ERK/NF-κB signaling pathway.Western blot and immunohistochemistry were carried out to evaluate the protein expression levels of RAF-1,MEK-2,ERK1/2 and NF-κB.RESULTS Acupuncture can prolong sleep duration,and improve mental state,activity,diet volume,learning ability and spatial memory.In addition,acupuncture increased the release of 1L-1β,1L-6 and TNF-αin serum and the hippocampus and inhibited the mRNA and protein expression of the ERK/NF-κB signaling pathway.CONCLUSION These findings suggest that acupuncture at Back-Shu point can inhibit the ERK/NF-κB signaling pathway and treat insomnia by increasing the release of inflammatory cytokines in the hippocampus.

The role of ERK1/2 signaling pathway in coronary microembolization-induced rat myocardial inflammation and injury

Objectives In this work,we explore the effect of atorvastatin on myocardial apoptosis and caspase-8 acti- vation after coronary microembolization(CME) in rats. Methods Fifty rats were randomly divided into five groups; the coronary microembolization(CME) group,the sham-operated (sham) control group,the gastric lavage control group, the atorvastatin lavage group,and the caspasse-8 inhibitor (N-acetyl-Ile-Glu-Thr-Asp-CHO,abbreviated as CHO) group,with 10 rats for each group.A microembolization ball was injected through the left ventricle for constructing the CME model.Animals in the sham control group were given an injection of physiological saline instead of the microembolization ball.Seven days before the operation,the atorvastatin group underwent gastric lavage with 20 mg/kg of atorvastatin once a day.Gastric lavage control animals underwent gastric lavage with an equivalent dose of physiological saline instead of the atorvastatin.Animals in the CHO group were given an intraperitoneal injection of 10 mg/kg of CHO 30 min before the operation.Six hours after the operation,cardiac ultrasonic detection was conducted on each group to measure the cardiac function indexes.TUNEL(Terminal-deoxynucleoitidyl transferase mediated dUTP nick end labeling) assays were used to measure myocardial apoptosis,and western blots were used to quantify the expression levels of activated caspase-3 and -8.Results(1) The echocardiographic parameters showed that,compared to the sham control animals,the left ventricular ejection fraction(LVEF) of the CME group was significantly decreased(P【0.05).In addition, cardiac sonography revealed a decrease in the left ventricular shortening fraction(FS) and cardiac output(CO), but an increase in the left ventricular end-diastolic dimension (LVEDd).Compared to the CME group,the atorvastatin and CHO groups exhibited significantly improved cardiac function (P【0.05).(2) When compared with the sham control,the myocardical apoptotic rate of the CME group,as well as the levels of activated caspase-3 and-8,increased significantly (P【0.05).The myocardial apoptotic rate,as well as the levels of activated caspase-3 and caspase-8 in the atorvastatin and CHO groups,decreased significandy(P【0.05) in comparison to the CME group.Conclusions The atorvastatin pretreatment clearly suppressed post-CME myocardial apoptosis and improved cardiac function.The most likely mechanism for these effects is the blockade of the myocardial death receptor -mediated apoptosis pathway.

Protective effects of Yishen Sanjie Huayu compound on the renal artery disease in rats with IgA nephropathy through ERK/NF-κB pathway

Objective:To observe the effect of Yishen Sanjie Huayu compound prescription on ERK/NF-κB signaling pathway in IgA nephropathy(IgAN)rats,and explore its effect on preventing and treating IgA nephropathy intrarenal arteriole disease.Methods:Fifty-five male SD rats were randomly divided into blank group,model group,ShenfukangⅡcapsule group and Losartan potassium tablet group.Bovine serum albumin(BSA)was used for intragastric administration and carbon tetrachloride(CCl4).IgAN rat model was established by subcutaneous injection and lipopolysaccharide(LPS)tail vein injection.ShenfukangⅡcapsule group and Losartan potassium tablet group were given each drug suspension 2ml/head/d one week after modeling Gavage was started.The blank group and the model group were given an equal volume of normal saline.The 24h urine protein(UTP)of the rats was measured at 4,8,and 12 weeks after the administration,and the blood creatinine(SCr)was measured after 12 weeks.,urea nitrogen(BUN),aldosterone(ADS),angiotensinⅡ(AngⅡ),immunohistochemical Envi-sion System two-step method to detect vascular endothelial growth factor(VEGF)and human matrix in the whole rat kidney and small artery area The expression of metalloproteinase-9(MMP-9),proliferating cell nuclear antigen(PCNA),extracellular regulatory protein kinase(ERK)1/2,nuclear transcription factor-κB(NF-κB),and the small arteries of rat kidney tissue The intima,media,vessel wall/vascular outer diameter value.Results:Compared with the model group,the expressions of VEGF,MMP-9,PCNA,ERK1/2 and NF-κB in kidney tissues of the ShenfukangⅡcapsule group and the Losartan potassium tablet group decreased(P<0.05),24hUTP and SCr,BUN level decreased(P<0.05),kidney tissue damage was alleviated;intima and vessel wall/vascular outer diameter values were significantly reduced(P<0.01),there was no significant difference in ADS between the groups.The AngⅡof the Tanpotassium tablets group was lower than that of the model group(P<0.05).Conclusion:Yishen Sanjie Huayu compound can inhibit the ERK/NF-κB signaling pathway in rats with IgA nephropathy,reduce the levels of VEGF,MMP-9,PCNA,ERK1/2,NF-κB,and inhibit intrarenal arteriole vascular endothelial cells Proliferate and reduce kidney damage.

Circ_0053943 complexed with IGF2BP3 drives uveal melanoma progression via regulating N6-methyladenosine modification of Epidermal growth factor receptor

Numerous studies have characterized the critical role of circular RNAs(circRNAs)as regulatory factors in the progression of multiple cancers.However,the biological functions of circRNAs and their underlying molecular mechanisms in the progression of uveal melanoma(UM)remain enigmatic.In this study,we identified a novel circRNA,circ_0053943,through re-analysis of UM microarray data and quantitative RT-PCR.Circ_0053943 was found to be upregulated in UM and to promote the proliferation and metastatic ability of UM cells in both in vitro and in vivo settings.Mechanistically,circ_0053943 was observed to bind to the KH1 and KH2 domains of insulin-like growth factor 2 mRNA-binding protein 3(IGF2BP3),thereby enhancing the function of IGF2BP3 by stabilizing its target mRNA.RNA sequencing assays identified epidermal growth factor receptor(EGFR)as a target gene of circ_0053943 and IGF2BP3 at the transcriptional level.Rescue assays demonstrated that circ_0053943 exerts its biological function by stabilizing EGFR mRNA and regulating the downstream mitogen-activated protein kinase/extracellular signal-regulated kinase(MAPK/ERK)signaling pathway.Collectively,circ_0053943 may promote UM progression by stabilizing EGFR mRNA and activating the MAPK/ERK signaling pathway through the formation of a circ_0053943/IGF2BP3/EGFR RNA-protein ternary complex,thus providing a potential biomarker and therapeutic target for UM.

Hypoxia-inducible factor-1α–mediated upregulation of CD99 promotes the proliferation of placental mesenchymal stem cells by regulating ERK1/2

BACKGROUND As human placenta-derived mesenchymal stem cells(hP-MSCs)exist in a physiologically hypoxic microenvironment,various studies have focused on the influence of hypoxia.However,the underlying mechanisms remain to be further explored.AIM The aim was to reveal the possible mechanisms by which hypoxia enhances the proliferation of hP-MSCs.METHODS A hypoxic cell incubator(2.5%O2)was used to mimic a hypoxic microenvironment.Cell counting kit-8 and 5-ethynyl-20-deoxyuridine incorporation assays were used to assay the proliferation of hP-MSCs.The cell cycle was profiled by flow cytometry.Transcriptome profiling of hP-MSCs under hypoxia was performed by RNA sequencing.CD99 mRNA expression was assayed by reverse transcription-polymerase chain reaction.Small interfering RNA-mediated hypoxia-inducible factor 1α(HIF-1α)or CD99 knockdown of hP-MSCs,luciferase reporter assays,and the ERK1/2 signaling inhibitor PD98059 were used in the mechanistic analysis.Protein expression was assayed by western blotting;immunofluorescence assays were conducted to evaluate changes in expression levels.RESULTS Hypoxia enhanced hP-MSC proliferation,increased the expression of cyclin E1,cyclin-dependent kinase 2,and cyclin A2,and decreased the expression of p21.Under hypoxia,CD99 expression was increased by HIF-1α.CD99-specific small interfering RNA or the ERK1/2 signaling inhibitor PD98059 abrogated the hypoxia-induced increase in cell proliferation.CONCLUSION Hypoxia promoted hP-MSCs proliferation in a manner dependent on CD99 regulation of the MAPK/ERK signaling pathway in vitro.

Inhibitory effects of oxyresveratrol on ERK and Smad1/2 phosphorylation and HSC activation in preventing carbon tetrachloride-induced rat liver fibrosis

Oxyresveratrol(ORes,trans-2,4,3′,5′-tetrahydroxy stilbene)naturally exists in mulberry,grapes,peanuts and other plants.It belongs to stilbene polyphenolic family and has an extra hydroxyl group at 2-position comparing with resveratrol(Res).Hence,ORes has stronger antioxidant activity than resveratrol.In present study,we employed a rat hepatic fibrosis model induced by carbon tetrachloride(CCl_(4))and administrated ORes via gavage feeding to study the protective effects and potential mechanisms of ORes against hepatic fibrosis.We demonstrated that rat liver oxidative damage induced by CCl_(4)was significantly alleviated after ORes feeding.Furthermore,the mRNA transcription levels ofα-smooth muscle actinn(˛-SMA),desmin,and two MMPs(MMP2 and MMP9)were reduced and the expression levels of transforming growth factorβ1(TGF-β1),p-small mother against decapen-taplegic protein(Smad)1/2 and p-extracellular signal-regulated kinases(ERK)1/2 in the liver tissue down-regulated dramatically.In a parallel study with Res,ORes showed more efficacious protective effect than Res against rat liver fibrosis,which is attributed to extended conjugation system due to the extra hydroxyl group at 2-position on ORes making it more electron-rich and susceptible to oxidation than Res.Therefore,dietary consumption of mulberry and other fruits containing ORes may be beneficial in the prevention of liver fibrosis.

Modulation effects of pressing manipulation on local inflammatory responses and ERK/NF-κB pathway in trigger point model rats

Objective:To investigate the mechanism of trigger point deactivation induced by pressing manipulation in a rat model and to explore its potential regulation of the inflammatory response through the extracellular signal-regulated kinase(ERK)/nuclear factor-κB(NF-κB)pathway.Methods:Fifty male Sprague-Dawley rats were randomly divided into a blank group,a model group,a pressing manipulation group,an ERK agonist group,and a pressing manipulation+ERK agonist group,with 10 rats in each group.Except for the blank group,rats in other groups were used to establish the trigger point rat model using the blunt blow combined with the eccentric exercise method.The pressing manipulation group underwent pressing manipulation intervention at the trigger points.The ERK agonist group received an injection of recombinant human epidermal growth factor via the tail vein.The pressing manipulation+ERK agonist group received interventions from both the pressing manipulation and ERK agonist groups.The pressure pain threshold(PPT)was measured by a mechanical pain threshold detector before and after the intervention.The histological changes were evaluated by hematoxylin-eosin staining after the intervention;the expression levels of ERK,phosphorylated ERK(p-ERK),NF-κB p65(p65),phosphorylated NF-κB p65(p-p65),and phosphorylated NF-κB inhibitor(p-IκB)were detected by Western blotting;the levels of interleukin(IL)-1β,IL-6,and tumor necrosis factor(TNF)-αwere detected by enzyme-linked immunosorbent assay.Results:The PPT increased(P<0.05);the inflammatory cells disappeared;the ratios of p-ERK/ERK,p-p65/p65,and p-IκB/β-actin,also the levels of IL-1β,IL-6,and TNF-αall decreased in the pressing manipulation group after the intervention compared with the model group(P<0.05).The PPT decreased significantly(P<0.05),the inflammatory cell presence increased,and the ratios of p-ERK/ERK and p-p65/p65 were elevated(P<0.05);additionally,the levels of IL-6 and TNF-αwere significantly higher in the pressing manipulation+ERK agonist group compared with the pressing manipulation group(P<0.05).The PPT was significantly lower(P<0.05),the inflammatory cell count was higher,the ratios of p-ERK/ERK and p-IκB/β-actin and the levels of IL-1βand TNF-αwere significantly higher in the ERK agonist group compared with the pressing manipulation+ERK agonist group(P<0.05).Conclusion:Pressing manipulation can effectively alleviate inflammation and pain in trigger point model rats,potentially by inhibiting the ERK/NF-κB signaling pathway.

Cytokine receptor-like factor 1(CRLF1)promotes cardiac fibrosis via ERK1/2 signaling pathway

Cardiac fibrosis is a cause of morbidity and mortality in people with heart disease.Anti-fibrosis treatment is a significant therapy for heart disease,but there is still no thorough understanding of fibrotic mechanisms.This study was carried out to ascertain the functions of cytokine receptor-like factor 1(CRLF1)in cardiac fibrosis and clarify its regulatory mechanisms.We found that CRLF1 was expressed predominantly in cardiac fibroblasts.Its expression was up-regulated not only in a mouse heart fibrotic model induced by myocardial infarction,but also in mouse and human cardiac fibroblasts provoked by transforming growth factor-β1(TGF-β1).Gain-and loss-of-function experiments of CRLF1 were carried out in neonatal mice cardiac fibroblasts(NMCFs)with or without TGF-β1 stimulation.CRLF1 overexpression increased cell viability,collagen production,cell proliferation capacity,and myofibroblast transformation of NMCFs with or without TGF-β1 stimulation,while silencing of CRLF1 had the opposite effects.An inhibitor of the extracellular signal-regulated kinase 1/2(ERK1/2)signaling pathway and different inhibitors of TGF-β1 signaling cascades,comprising mothers against decapentaplegic homolog(SMAD)-dependent and SMAD-independent pathways,were applied to investigate the mechanisms involved.CRLF1 exerted its functions by activating the ERK1/2 signaling pathway.Furthermore,the SMAD-dependent pathway,not the SMAD-independent pathway,was responsible for CRLF1 up-regulation in NMCFs treated with TGF-β1.In summary,activation of the TGF-β1/SMAD signaling pathway in cardiac fibrosis increased CRLF1 expression.CRLF1 then aggravated cardiac fibrosis by activating the ERK1/2 signaling pathway.CRLF1 could become a novel potential target for intervention and remedy of cardiac fibrosis.

MAPK/ERK regulation of P53 in human epidermoid carcinoma cell line A431

Objective:To observe the impact of activation and inhibition of mitogen activated protein kinases(MAPK)/extracellular signalregulated protein kinase(ERK)signaling pathway on the proliferation and apoptosis of cutaneous squamous cell carcinoma(SCC).cells and investigate the interaction mechanism between MAPK/ERK signaling pathway and tumor suppressor gene P53 in SCC.Methods:Human A431 cells were cultured and divided into MAPK/ERK inhibition groups with low-,medium-and highconcentration of inhibitors(PD98059+DMSO),MAPK/ERK activation groups with low-,medium-and high-concentration of stimuli(IGF+PBS)and blank control group(DMSO).The cell proliferation in vitro was detected by MTT assay,with the cell apoptosis detected by flow cytometry(FCM)and the protein expression of P-ERK and P53 detected by western blot in each group.Results:The A431 cell proliferation was inhibited by different concentrations of PD98059 with a clear concentration-effect and time-effect relationship(p<.05);and the cell proliferation was promoted by the different concentrations of IGF with a clear concentration-effect and time-effect relationship(p<.05).The FCM results showed a significant increase in the apoptosis rate of A431 cells which were treated with PD98059,with a clear concentration-effect relationship(p<.05);while the apoptosis rate was decreased significantly after A431 cells were treated with IGF,also with a concentration-effect relationship(p<.05).The western blot results showed that the expression of P-ERK protein was decreased but the expression of P53 was increased after A431 cells were treated with PD98059.With the concentration of PD98059 going up,the decrease in P-ERK and the increase in P53 were more significant(p<.05);while the expression of P-ERK protein was increased but the expression of P53 was decreased after A431 cells were treated with IGF.With the concentration of IGF going up,the increase in P-ERK and the decrease in P53 were more significant(p<.05).According to Pearson correlation analysis,the expression of P53 was negatively correlated to that of P-ERK(p<.05).Conclusions:After MAPK/ERK signaling pathway was activated by IGF in A431 cells,the expression of pro-apoptotic factor P53 was decreased with the ability of cell proliferation enhanced and the ability of apoptosis reduced.However,after the inhibition of MAPK/ERK signaling pathway,the expression of pro-apoptotic factor P53 was increased with the ability of cell proliferation reduced and the ability of apoptosis increased.

Different Concentrations of Notoginsenoside Rg1 Attenuate Hypoxic and Hypercapnia Pulmonary Hypertension by Reducing the Expression of ERK in Rat PASMCs

Pulmonary arterial hypertension (PAH) is a serious disease which is characterized by increased vascular resistance and pressure. We have previously hypothesized that panax notoginseng saponins (PNS) might attenuate pulmonary vasoconstriction under hypoxia and hypercapnia condition. This study aims to investigate the effect of notoginsenoside Rg1, a main ingredient of PNS, with various concentrations (8, 40, 100 mg/L, respectively) on extracellular signal regulated kinase (ERK1/2) signaling pathway in pulmonary arterial smooth muscle cells (PASMCs). In addition, PASMCs were randomly divided into six groups: SD rat under normoxic condition as control group (N group), hypoxia hypercapnia group (H group), DMSO control group (HD group), Rg1-treatment groups (RgLRgM and RgH group). Western-blot and RT-PCR were used to test the expression of p-ERK protein and the expression of ERK1 mRNA and ERK2 mRNA. This study provided the evidence that the expression of p-ERK protein and the expression of ERK1 mRNA and ERK2 mRNA in HD group and H group were obviously higher than that in N group (P < 0.01), Whereas the level of ERK1/2 mRNA in Rg1-treatment groups was significantly lower than that in HD group and H group (P < 0.01), and the proper concentration of Rg1 is 40 mg/L. These results suggested that notoginsenoside Rg1 can attenuate pulmonary vasoconstriction which may lead to HHPV through reducing the expression of ERK1/2.

PLX8394,a RAF inhibitor,inhibits enterovirus 71 replication by blocking RAF/MEK/ERK signaling

Enterovirus 71(EV71)poses a serious threat to human health,with scattered outbreaks worldwide.There are several vaccines against a few EV71 strains but no efficient drug for the treatment of EV71 infection.Therefore,it is urgent and of significance to develop anti-EV71 drugs.Here,we found that PLX8394,a RAF inhibitor,possesses high antiviral activity against EV71 in vitro,being superior to the traditional clinical drug ribavirin.Moreover,PLX8394 exhibits broad-spectrum antiviral activity against enteroviruses.Notably,in a suckling mouse model,PLX8394 provided a 70%protection rate for EV71-infected mice,reduced the viral load in liver and heart tissues,and relieved the inflammatory response.A mechanistic study showed that PLX8394 inhibited EV71 by suppressing the RAF/MEK/ERK signaling pathway.Thus,PLX8394 lays a foundation for the development of new drugs against EV71.

Apolipoprotein A1 suppresses the hypoxia-induced angiogenesis of human retinal endothelial cells by targeting PlGF

AIM:To investigate the anti-angiogenic effect of apolipoprotein A1(apoA1)on primary human retinal vascular endothelial cells(HRECs)and explore the possible mechanism.METHODS:The primary HRECs were transfected with apoA1-GFP recombinant lentiviral and were compared with cells undergoing transfection with empty lentiviral vectors.Hypoxia chambers were used to simulate the anoxic environment of cells under pathological condition.The concentrations of secreted vascular endothelial growth factor(VEGF)and placental growth factor(PlGF)were measured by enzyme-linked immunosorbent assay(ELISA).Cell migration ability was detected by wound healing assay.The sprouting of HRECs was determined by tube formation assay.The protein levels of extracellular signal regulated kinase 1/2(ERK1/2)and phosphor ylated ERK1/2(p-ERK1/2)were measured by Western blot.RESULTS:Overexpressed apoA1 in hypoxia-induced HRECs significantly suppressed PlGF(0.67±0.10 folds,P=0.007).Overexpressed apoA1 also attenuated hypoxiainduced cell migration(0.32±0.11 folds,P<0.0001),tube formation(0.66±0.01 folds,P<0.0001)and the phosphorylation levels of ERK(0.6±0.11 folds,P=0.025).Pretreatment of mitogen-activated protein kinase kinase(MEK)inhibitor(U0126)further reduced the PlGF and angiogenesis in hypoxia-induced HRECs.CONCLUSION:ApoA 1 inhibits the angiogenesis at least in part by inactivating ERK1/2 in hypoxia-induced HRECs.Moreover,apoA1 suppresses the PlGF expression,which selectively associated with pathological angiogenesis.

Vitamin C induces periodontal ligament progenitor cell differentiation via activation of ERK pathway mediated by PELP1

The differentiation of periodontal ligament(PDL)progenitor cells is important for maintaining the homeostasis of PDL tissue and alveolar bone.Vitamin C(VC),a water-soluble nutrient that cannot be biosynthesized by humans,is vital for mesenchymal stem cells differentiation and plays an important role in bone remodeling.Therefore,the objective of this study was to determine the function and mechanism of VC in PDL progenitor cells osteogenic differentiation at the molecular level.We demonstrated that VC could induce the osteogenic differentiation and maturation of PDL progenitor cell without other osteogenic agents.During the process,VC preferentially activated ERK1/2 but did not affect JNK or p38.Co-treatment with ERK inhibitor effectively decreased the Vitamin C-induced expression of Runx2.ERK inhibitor also abrogated Vitamin C-induced the minimized nodules formation.PELP1,a nuclear receptor co-regulator,was up-regulated under VC treatment.PELP1 knockdown inhibited ERK phosphorylation.The overexpression of PELP1 had a positive relationship with Runx2 expression.Taken together,we could make a conclude that VC induces the osteogenic differentiation of PDL progenitor cells via PELP1-ERK axis.Our fi nding implies that VC may have a potential in the regeneration medicine and application to periodontitis treatment.

Apoptosis in glioma-bearing rats after neural stem cell transplantation

Abnormal activation of the Ras/Raf/Mek/Erk signaling cascade plays an important role in glioma. Inhibition of this aberrant activity could effectively hinder glioma cell proliferation and promote cell apoptosis. To investigate the mechanism of gJioblastoma treatment by neural stem ceiJ trans- plantation with respect to the Ras/Raf/Mek/Erk pathway, C6 glioma cells were prepared in sus- pension and then infused into the rat brain to establish a glioblastoma model. Neural stem cells isolated from fetal rats were then injected into the brain of this glioblastoma model. Results showed that Raf-1, Erk and Bcl-2 protein expression significantly increased, while Caspase-3 protein expression decreased. After transplantation of neural stem cells, Raf-1, Erk and Bcl-2 protein expression significantly decreased, while Caspase-3 protein expression significantly in-creased. Our findings indicate that transplantation of neural stem cells may promote apoptosis of glioma cells by inhibiting Ras/Raf/Mek/Erk signaling, and thus may represent a novel treatment approach for glioblastoma.

Acetyl-11-keto-β-boswellic acid extracted from Boswellia serrata promotes Schwann cell proliferation and sciatic nerve function recovery

Frankincense can promote blood circulation. Acetyl-11-keto-β-boswellic acid （AKBA） is a small molecule with anti-inflammatory properties that is derived from Boswellia serrata. Here, we hypothesized that it may promote regeneration of injured sciatic nerve. To address this hypothesis, we established a rat model of sciatic nerve injury using a nerve clamping method. Rats were administered AKBA once every 2 days at doses of 1.5, 3, and 6 mg/kg by intraperitoneal injection for 30 days from the 1st day after injury. Sciatic nerve function was evaluated using the sciatic functional index. Degree of muscle atrophy was measured using the triceps surae muscle Cuadros index.Neuropathological changes were observed by hematoxylin-eosin staining. Western blot analysis was used to detect expression of phospho-extracellular signal-regulated kinase 1 and 2 （p-ERK1/2） in injured nerve. S100 immunoreactivity in injured nerve was detected by immunohistochemistry. In vivo experiments showed that 3 and 6 mg/kg AKBA significantly increased sciatic nerve index, Cuadros index of triceps muscle, p-ERK1/2 expression, and S100 immunoreactivity in injured sciatic nerve of sciatic nerve injury model rats. Furthermore,for in vitro experiments, Schwann cells were treated with AKBA at 0–20 μg/mL. Proliferation of Schwann cells was detected by Cell Counting Kit-8 colorimetry assay. The results showed that 2 μg/mL AKBA is the optimal therapeutic concentration. In addition, ERK phosphorylation levels increased following 2 μg/mL AKBA treatment. In the presence of the ERK1/2 inhibitor, PD98059 （2.5 μL/mL）, the AKBA-induced increase in p-ERK1/2 protein expression was partially abrogated. In conclusion, our study shows that AKBA promotes peripheral nerve regeneration with ERK protein phosphorylation playing a key role in this process.

Enhancing osteogenic bioactivities of coaxial electrospinning nanoscaffolds through incorporating iron oxide nanoparticles and icaritin for bone regeneration

Bone tissue engineering provides a promising strategy for the treatment of bone defects.Nonetheless,the clinical utilization of biomaterial-based scaffolds is constrained by their inadequate mechanical strength and absence of osteo-inductive properties.Here,we proposed to endow nano-scaffold(NS)constructed by coaxial electrospinning technique with enhanced osteogenic bioactivities and mechanical properties by incorporating biocompatible magnetic iron oxide nanoparticles(IONPs)and icaritin(ICA).Four types of nano-scaffolds(NS,ICA@NS,NS-IONPs and ICA@NS-IONPs)were prepared.The incorporation of ICA and IONPs minimally impact their surface morphological and chemical properties.IONPs enhanced the mechanical properties of NS scaffolds,including hardness,tensile strength,and elastic modulus.In vitro assessments demonstrated that ICA@NS-IONPs exhibited enhanced osteogenic bioactivities towards mouse calvarial pre-osteoblast cell line MC3T3-E1 as evidenced by detecting the alkaline phosphatase(ALP)activity level,expressions of osteogenesis-related genes and proteins as well as mineralized nodule formation.Mechanistic investigations revealed that MEK/ERK(MAP kinase-ERK kinase(MEK)/extracellularsignal-regulated kinase(ERK))signaling pathway could offer a plausible explanation for the osteogenic differentiation of MC3T3-E1 cells induced by ICA@NS-IONPs.Furthermore,the implantation of nano-scaffolds in rat skull defects exhibited a substantial improvement in in vivo bone regeneration.Therefore,IONPs and ICA incorporated coaxial electrospinning nano-scaffolds present a novel strategy for the optimization of scaffolds for bone tissue engineering.

Development of a high-content screening method to evaluate the cellular population-based biological activity of new siRNA delivering reagent

Normally, cellular responses to modified siRNAs or new siRNA delivery systems have been studied in group cell behavior by PCR, western blotting and fluorescence microscopy. In this study, we present a novel high-content screening （HCS） strategy to evaluate a novel delivery system （named CLD） of siRNA therapeutics, with which both the content of intracellular siRNAs and changes in protein expressing levels have been quantified in group cells and cellular population. We also observed that with the better cell uptake, CLD provided siRNA therapeutics （siBraf） better antitumor capability. This novel strategy was proved to be with efficiency, accuracy and high competency to adherent cell lines, thus making siRNA research more simplified.