Prox1 Suppresses Proliferation and Drug Resistance of Retinoblastoma Cells via Targeting Notch1

Objective Retinoblastoma(RB)is a prevalent type of eye cancer in youngsters.Prospero homeobox 1(Prox1)is a homeobox transcriptional repressor and downstream target of the proneural gene that is relevant in lymphatic,hepatocyte,pancreatic,heart,lens,retinal,and cancer cells.The goal of this study was to investigate the role of Prox1 in RB cell proliferation and drug resistance,as well as to explore the underlying Notch1 mechanism.Methods Human RB cell lines(SO-RB50 and Y79)and a primary human retinal microvascular endothelial cell line(ACBRI-181)were used in this study.The expression of Prox1 and Notch1 mRNA and protein in RB cells was detected using quantitative real time-polymerase chain reaction(RT-qPCR)and Western blotting.Cell proliferation was assessed after Prox1 overexpression using the Cell Counting Kit-8 and the MTS assay.Drug-resistant cell lines(SO-RB50/vincristine)were generated and treated with Prox1 to investigate the role of Prox1 in drug resistance.We employed pcDNA-Notch1 to overexpress Notch1 to confirm the role of Notch1 in the protective function of Prox1.Finally,a xenograft model was constructed to assess the effect of Prox1 on RB in vivo.Results Prox1 was significantly downregulated in RB cells.Overexpression of Prox1 effectively decreased RB cell growth while increasing the sensitivity of drug-resistant cells to vincristine.Notch1 was involved in Prox1’s regulatory effects.Notch1 was identified as a target gene of Prox1,which was found to be upregulated in RB cells and repressed by increased Prox1 expression.When pcDNA-Notch1 was transfected,the effect of Prox1 overexpression on RB was removed.Furthermore,by downregulating Notch1,Prox1 overexpression slowed tumor development and increased vincristine sensitivity in vivo.Conclusion These data show that Prox1 decreased RB cell proliferation and drug resistance by targeting Notch1,implying that Prox1 could be a potential therapeutic target for RB.

Axonal growth inhibitors and their receptors in spinal cord injury:from biology to clinical translation

Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.

The mechanism of regulating macrophage polarization based on Notch1 signaling pathway to improve joint inflammation in adjuvant arthritis rats

Objective:To study the impact of the Notch1/Jagged1/RBP-Jκ/Hes1 signaling pathway on macrophage polarization and its role in modulating the inflammatory response in rats with adjuvant arthritis(AA).Methods:The rats were randomly divided into three groups(6 rats):the healthy group(NC),the model group(MC),and the Notch1 inhibitor group(FLI).Medication was administered after 12 days of inducing inflammation.After 30 days,the arthritis index(AI)and degree of swelling in the right hind foot joint(E)were measured in each group.The expression levels of CD80^(+)and CD163^(+)cells in peripheral blood macrophages of rats were analyzed by flow cytometry.The standards of IL-4,IL-10,IL-1β,and TNF-α in rat serum were gauged by Enzyme-linked immunosorbent assay.The expression of Notch1,Jagged1,RBP-Jκ,and Hes1 proteins in rat synovial tissue was detected using Western blot.Results:The degree of swelling(E)and arthritis index(AI)in the MC group rats with AA were significantly higher than those in the NC group(P<0.01).CD80^(+)cell expression was significantly higher compared to the control group(P<0.01),while CD163^(+)cell expression was significantly lower than the control group(P<0.01).IL-1βand TNF-α expression levels were significantly elevated(P<0.01),whereas IL-4 and IL-10 expression levels were significantly decreased(P<0.01).Notch1,RBP-Jκ,Jagged1,and Hes1 protein expression levels were significantly increased(P<0.01).In comparison to the MC group,the rats in the Notch1 inhibitor group exhibited a significant reduction in toe swelling and arthritis index(P<0.01).CD80^(+)cell expression was significantly decreased(P<0.01),while CD163+cell expression was significantly increased(P<0.01).IL-1β and TNF-α expression levels were significantly decreased(P<0.05),whereas IL-4 and IL-10 levels were significantly increased(P<0.01).Notch1,Jagged1,Hes1,and RBP-Jκ protein expression levels were significantly decreased(P<0.05).Correlation analysis revealed a positive association between CD80^(+)and Notch1,Jagged1,Hes1,and RBP-Jκ(P<0.01),while CD163^(+)showed a negative correlation with the expression of these proteins(P<0.01).Conclusion:The Notch1/Jagged1/RBP-Jκ/Hes1 signaling axis regulates macrophage polarization to M2 type and reduces inflammation in AA rats.

Growth differentiation factor 11 promotes macrophage polarization towards M2 to attenuate myocardial infarction via inhibiting Notch1 signaling pathway

Background:Myocardial infarctions(MI)is a major threat to human health especially in people exposed to cold environment.The polarization of macrophages towards different functional phenotypes(M1 macrophages and M2 macrophages)is closely related to MI repairment.The growth differentiation factor 11(GDF11)has been reported to play a momentous role in inflammatory associated diseases.In this study,we examined the regulatory role of GDF11 in macrophage polarization and elucidated the underlying mechanisms in MI.Methods:In vivo,the mice model of MI was induced by permanent ligation of the left anterior descending coronary artery(LAD),and mice were randomly divided into the sham group,MI group,and MI+GDF11 group.The protective effect of GDF11 on myocardial infarction and its effect on macrophage polarization were verified by echocardiography,triphenyl tetrazolium chloride staining and immunofluorescence staining of heart tissue.In vitro,based on the RAW264.7 cell line,the effect of GDF11 in promoting macrophage polarization toward the M2 type by inhibiting the Notch1 Signaling pathway was validated by qRT-PCR,Western blot,and flow cytometry.Results:We found that GDF11 was significantly downregulated in the cardiac tissue of MI mice.And GDF11 supplementation can improve the cardiac function.Moreover,GDF11 could reduce the proportion of M1 macrophages and increase the accumulation of M2 macrophages in the heart tissue of MI mice.Furthermore,the cardioprotective effect of GDF11 on MI mice was weakened after macrophage clearance.At the cellular level,application of GDF11 could inhibit the expression of M1 macrophage(classically activated macrophage)markers iNOS,interleukin(IL)-1β,and IL-6 in a dose-dependent manner.In contrast,GDF11 significantly increased the level of M2 macrophage markers including IL-10,CD206,arginase 1(Arg1),and vascular endothelial growth factor(VEGF).Interestingly,GDF11 could promote M1 macrophages polarizing to M2 macrophages.At the molecular level,GDF11 significantly down-regulated the Notch1 signaling pathway,the activation of which has been demonstrated to promote M1 polarization in macrophages.Conclusions:GDF11 promoted macrophage polarization towards M2 to attenuate myocardial infarction via inhibiting Notch1 signaling pathway.

Electroacupuncture improves neuropathic pain Adenosine, adenosine 5'-triphosphate disodium and their receptors perhaps change simultaneously

Applying a stimulating current to acupoints through acupuncture needles–known as electroacupuncture–has the potential to produce analgesic effects in human subjects and experimental animals. When acupuncture was applied in a rat model, adenosine 5-triphosphate disodium in the extracellular space was broken down into adenosine, which in turn inhibited pain transmission by means of an adenosine A1 receptor-dependent process. Direct injection of an adenosine A1 receptor agonist enhanced the analgesic effect of acupuncture. The analgesic effect of acupuncture appears to be mediated by activation of A1 receptors located on ascending nerves. In neuropathic pain, there is upregulation of P2X purinoceptor 3 （P2X3） receptor expression in dorsal root ganglion neurons. Conversely, the onset of mechanical hyperalgesia was diminished and established hyperalgesia was significantly reversed when P2X3 receptor expression was downregulated. The pathways upon which electroacupuncture appear to act are interwoven with pain pathways, and electroacupuncture stimuli converge with impulses originating from painful areas. Electroacupuncture may act via purinergic A1 and P2X3 receptors simultaneously to induce an analgesic effect on neuropathic pain.

Jagged1 Notch1与NF-κB蛋白在寻常型银屑病中的表达

目的检测寻常型银屑病患者皮肤组织中Jagged1、Notch1与NF-κB蛋白的表达,探讨Notch信号通路的异常激活与银屑病发病机制的关系。方法收集2012年7月~2014年7月年西南医科大学附属医院皮肤科寻常型银屑病40例患者的病理标本(病例组)及40例正常人的皮肤标本(对照组),采用免疫组织化学法分别检测银屑病患者皮损区、非皮损区及对照组皮肤标本的Jagged1、Notch1与NF-κB表达。结果 Jagged1、Notch1与NF-κB在银屑病皮损区组比其他两组表达明显升高,差异有统计学意义(P<0.05);非皮损区组与对照组表达相似,差异无统计学意义(P>0.05)。且银屑病皮损区组Jagged1、Notch1和NF-κB三者间阳性表达呈正相关(P<0.01)。结论Jagged1、Notchl、NF-κB蛋白在寻常型银屑病患者中均呈现高表达,且银屑病皮损区Jagged1、Notch1和NF-κB三者阳性表达呈正相关,因此Jagged1、Notchl、NF-κB蛋白可能在银屑病的发病机制中占有重要地位。

原因不明复发性流产中CD4^+ Notch1^+ T细胞与IL-10的相关性分析

探讨原因不明复发性流产(URSA)中CD4+Notch1+T细胞(Notch1+占CD4+T细胞的比例)与白介素-10(IL-10)表达水平的相关性。以雌性CBA/J×雄性Balb/c为正常妊娠模型,以雌性CBA/J×雄性DBA/2J为自然流产模型,采用流式细胞术检测6例未孕CBA/J雌性小鼠、6例正常妊娠模型孕14天CBA/J雌性小鼠和6例自然流产模型孕14天CBA/J雌性小鼠脾细胞中CD4+Notch1+T细胞,同时运用ELISA法检测其血清中IL-10的表达水平。相比于未孕组,正常妊娠模型中CD4+Notch1+T细胞比例减少,而自然流产模型中CD4+Notch1+T细胞比例增加,正常妊娠模型与自然流产模型中CD4+Notch1+T细胞比例差异有统计学意义(P<0.05)。CD4+Notch1+T细胞比例与IL-10负相关(r=-0.568,P<0.05)。结论:CD4+Notch1+T细胞可能参与原因不明复发性流产发病机制,拮抗Notch1+表达有可能成为治疗URSA新途径。

Inhibitory Effects of MicroRNA-34a on Cell Migration and Invasion of Invasive Urothelial Bladder Carcinoma by Targeting Notch1

MicroRNAs （miRNAs or miRs） are a class of short, non-coding RNAs that participate in various oncological processes. This study aims to explore the roles of microRNA-34a （miR-34a） in invasive urothelial bladder carcinoma. miR-34a was transfected into bladder cancer cell lines 253J and J82. The miR-34a expression levels in tissues and cells were detected by using qRT-PCR. The Notch1 expression was detected by qRT-PCR and Western blotting. Cell migratory and invasive abilities were measured by Transwell chamber assay. Bioinformatics and luciferase assay were performed to predict and analyze the binding sites between miRNA-34a and Notch1. It was found that there was aberrant expression of miR-34a in bladder cancer tissues. Moreover, we revealed that ectopic expression of miR-34a suppressed cell migration and invasion, while forced expression of Notch1 increased cell migratory and invasive abilities. Finally, we observed that miR-34a transfection significantly down-regulated luciferase activity and reduced the mRNA and protein levels of Notch1. Our study concluded that microRNA-34a antagonizes Notch1 and inhibits cell migration and invasion of bladder cancer cells, which indicates the tumor-suppressive function of microRNA-34a in bladder cancer.

Optogenetics-induced activation of glutamate receptors improves memory function in mice with Alzheimer’s disease

Optogenetics is a combination of optics and genetics technology that can be used to activate or inhibit specific cells in tissues. It has been used to treat Parkinson’s disease, epilepsy and neurological diseases, but rarely Alzheimer’s disease. Adeno-associated virus carrying the CaMK promoter driving the optogenetic channelrhodopsin-2 (CHR2) gene (or without the CHR2 gene, as control) was injected into the bilateral dentate gyri, followed by repeated intrahippocampal injections of soluble low-molecular-weight amyloid-β1–42 peptide (Aβ1–42). Subsequently, the region was stimulated with a 473 nm laser (1–3 ms, 10 Hz, 5 minutes). The novel object recognition test was conducted to test memory function in mice. Immunohistochemical staining was performed to analyze the numbers of NeuN and synapsin Ia/b-positive cells in the hippocampus. Western blot assay was carried out to analyze the expression levels of glial fibrillary acidic protein, NeuN, synapsin Ia/b, metabotropic glutamate receptor-1a (mGluR-1a), mGluR-5, N-methyl-D-aspartate receptor subunit NR1, glutamate receptor 2, interleukin-1β, interleukin-6 and interleukin-10. Optogenetic stimulation improved working and short-term memory in mice with Alzheimer’s disease. This neuroprotective effect was associated with increased expression of NR1, glutamate receptor 2 and mGluR-5 in the hippocampus, and decreased expression of glial fibrillary acidic protein and interleukin-6. Our results show that optogenetics can be used to regulate the neuronal-glial network to ameliorate memory functions in mice with Alzheimer’s disease. The study was approved by the Animal Resources Committee of Jinan University, China (approval No. LL-KT-2011134) on February 28, 2011.

Buyang Huanwu decoction up-regulates Notch1 gene expression in injured spinal cord

Expression of genes in the Notch signaling pathway is altered in the injured spinal cord, which indicates that Notch participates in repair after spinal cord injury. Buyang Huanwu decoction, a traditional Chinese herbal preparation, can promote the growth of nerve cells and nerve fibers; however, it is unclear whether Buyang Huanwu decoction affects the Notch signaling pathway in injured spinal cord. In this study, a rat model was established by injuring the T10 spinal cord. At 2 days after injury, rats were intragastrically administered 2 m L of 0.8 g/m L Buyang Huanwu decoction daily until sacrifice. Real-time reverse transcription polymerase chain reaction analysis demonstrated that at 7, 14 and 28 days after injury, the expression of Notch1 was increased in the Buyang Huanwu decoction group compared with controls. These findings confirm that Buyang Huanwu decoction can promote the expression of Notch1 in rats with incomplete spinal cord injury, and may indicate a mechanism to promote the repair of spinal cord injury.

MicroRNA-34a Inhibits Human Brain Glioma Cell Growth by Downregulation of Notch1

The effects of microRNA-34a （miR-34a）-regulated Notch1 gene on the proliferation and apoptosis of the human glioma cell line U87 were investigated in this study. The U87 cells were divided into miR-34a mimics, negative control, mock transfection and blank control groups in terms of different treatments. In miR-34a mimics group, human U87 glioma cells were transfected with miR-34a mimics by using lipofectamine 2000. The cells transfected with nonsense microRNA were set up as negative control group. Those treated with lipofectamine 2000 only were designated to the mock tranfection group. In the blank control group, the cells were cultured routinely and no treatment was given. The expression of miR-34a and Notch1 was detected by using real-time RT-PCR. Western blotting was employed to monitor the change in Notch1 protein. Cell proliferation and apoptosis were measured by CCK-8 and flow cytometry. The results showed that the proliferative ability of U87 cells was significantly reduced and the apoptotic cells increased in miR-34a mimics group relative to control groups. The expression of miR-34a was significantly up-regulated in mimics group as compared with control groups （P〈0.05）. Furthermore, Notch1 protein levels were significantly decreased in miR-34a mimics group when compared with control groups （P〈0.05）, but the mRNA expression of Notch1 showed no significant difference among these groups. It was concluded that miR-34a may suppress the proliferation and induce apoptosis of U87 cells by decreasing the expression of target gene Notch1, suggesting that miR-34a may become a promising gene therapeutic target for brain glioma.

Synthesis and Evaluation of 8-[^(131)I]Iodo-substituted Imidazopyridine Derivative as Single Photon Emission Computed Tomography Tracer for Peripheral Benzodiazepine Receptors

A novel N-methyl, N-phenyl-[6-chloro-2-（4-chlorophenyl）-8-iodoimidazo[1, 2-a]- pyridine-3-yl]acetamide （compound Ⅴ） was synthesized, radiolabelled with 131I and evaluated in vitro. In vitro cell uptake studies showed that MDA-MB-231 cells yield four-fold higher specific uptake of [^131I]-compound Ⅵ than MCF-7 cells, corresponding to the increased expression of PBR in MDA-MB-231 cells. Blocking studies significantly reduced the MDA-MB-231 cells uptake of [^131I]-compound Ⅵ. It indicated that [^131I]-compound Ⅵ might be a potential SPECT radioligand for imaging of PBR.

Immunoglobulin G1 binding with various molecular receptors: A new paradigm of IgG1 as a potential adjuvant

Objective: To explore the possible IgG1 binding receptors by protein-protein docking experiments. Methods: The protein-protein cognate interactions such as IgG with Fc Receptors (FcRs) potentiate signaling cascades to ameliorate antigen uptake, processing and presentation are studied by protein-protein docking experiments. Results: However, the propensity of IgG interactions with other cognate receptors largely remains obscure. In this direction, possibilities of IgG1 binding with various five receptors were explored. In this study, we report previously unidentified associations between IgG1 and other receptors. Herein, we show that IgG1 binds to the granulocyte-macrophage receptor, β common receptor and complementaryreceptor(complementary receptor I and complementary receptor II) to form a complex structure. We show the binding ability and important protein-protein interactions of IgG1 with four receptors in comparison to Fc Receptor, and also find out the conserved amino acids and hydrophobic-hydrophobic interactions amongst them. Conclusions: Comparative interaction studies of IgG1 binding to various receptors revealed close similarities of IgG1 binding to its native receptor Fc. In conclusion, our study has shown the comparable binding efficiency of four receptors to IgG1 apart from the conventional Fc receptor.

Activation of GABAB receptors alleviates depressive-like behavior induced by chronic cerebral ischemia via upredulation of BDNF in rats

Aim To investigate the mechanisms underlying depressive-like behavior induced by chronic cerebral is- chemia in rats. Methods In the present study, a chronic cerebral hypoperfusion model was established by perma- 2VO） in rats. Two weeks after 2VO, GAB- nent bilateral common carotid arteries occlusion （two-vessel occlusion, AB receptor agonist baclofen （25 mg · kg^-1 . d^-1 i p ） was administrated for 21 days. The FST was performed to evaluate depressive-like behavior in which the immobility time was recorded. In addition, the expression of brain derived neurotrophic factor （BDNF） in hippocampal CA1 was measured by Western blot. Results The immobility time of 2VO group was significantly prolonged and the expression of BDNF was decreased by 28.95% compared with sham group. After activation of GABAB receptors by baclofen, the immobility time was significantly reduced and the expression of BDNF was increased by 47.91% compared with 2VO group. Conclusion 2VO induced ob- vious depressive-like behavior in rats. Activation of GABAB receptors alleviates the depressive-like behavior in- duced by chronic cerebral ischemia via upredulation of BDNF in hippocampal CA1 in rats.

D₁and TrkB Receptors Take Charge of the Molecular Antidepressant Action in Cultured Astroglial Cells

In psychopharmacology of depression, we observe two ways of research. One group is focused on catecholamines action. Second one fixes attention on neuronal morphogenesis and synaptic plasticity. The intimate connection of astrocytes, neurons and synaptic endings determines glial participation in neural homeostasis. Consequently this situation enlarges the role of astrocytes in the CNS synaptic plasticity. Brain Derived Neurotrophic factor and its receptor TrkB suppose to coordinate both of the above mentioning signaling pathways in depression disturbances. In our experiment, we have exploited striatal tissue because in our opinion this structure is misjudged in pathophysiology of depression alas;Several hypothesis proposed striatum as important in future intention activity structure. RT-PCR analysis was used to determine D1, BDNF and TrkB mRNA expression in cultured striatal astroglial cells. Administration of three representative antidepressants (ADs) like amitriptyline, moclobemide and sertraline to astroglial culture medium increase the D1, BDNF/TrkB mRNA expression. Our previous study showed that the stimulation of cAMP to CREB pathway after D1 receptors excitation constituted a common response to ADs. The present results signify that D1, BDNF/TrkB link which is next neural track (after cAMP/PKA) involved in the CNS adaptation to external conditions altered by chronic ADs treatment. Moreover, the striatum tissue appears to be important formation which takes an active part in antidepressant action thus essential in depression disorder etiology.

Effects of Activation and Blockade of Serotonin 5-HT1A Receptors on the Immune Response in Rats Selected for Different Levels of Aggressiveness

The present study examines the effects of serotonin (5-HT) 1A receptor ligands on humoral im-mune response in two rat lines selected for over 75 generations for the enhancement or elimination of aggression. Activation of presynaptic 5-HT1A receptors with a low dose of the selective 5-HT1A receptor agonist 8-OH-DPAT (0.1 mg/kg) or the blockade of postsynaptic 5-HT1A receptors with the antagonist WAY-100635 (1.0 mg/kg) did not affect the numbers of IgM-antibody forming cells (IgM-AFC) in the spleen of highly aggressive rats, which were characterized by higher immune responsiveness compared to nonaggressive line. On the other hand, the same doses of 8-OH-DPAT and WAY-100635, as well as a higher dose of 8-OH-DPAT (1.0 mg/kg), which is known to activate postsynaptic 5-HT1A receptors, produce immunostimulation in nonaggressive rats. However, only the highest dose of 8-OH-DPAT (5.0 mg/kg) was able to cause immunosuppression in nonaggressive rats that was mainly dependent on stimulation of postsynaptic 5-HT1A receptors. In contrast to nonaggressive rats, the dose of 1.0 mg/kg 8-OH-DPAT was sufficient to produce a decrease in the numbers of IgM-AFC in highly aggressive rats. Thus, pharmacological activation of pre- and postsynaptic 5-HT1A receptors, as well as the blockade of postsynaptic 5-HT1A receptors, produced different effects on the immune response in two lines of rats selected for high level of aggression or its absence. These data may have implications for more efficient treatments of a number of mental disorders associated with abnormal aggression.

Hypoxia Downregulates the Angiogenesis in Human Placenta via Notch1 Signaling Pathway

Placentation, which is critical for maternal-fetal exchange of nutrients and gases, is a complicated process comprising stepwise vasculogenesis and angiogenesis. Hypoxia caused by impaired trophoblast invasion may cause various angiogenic abnormalities in human placenta. The Notch1 signaling pathway plays an important role in the regulation of angiogenesis. The angiogenesis of human umbilical vein endothelial cells（HUVECs） under normal/hypoxic conditions and the m RNA/protein level of Notch1/Dell4/Jagged1 were investigated in this study. The effects of DAPT/JAG-1 on the migration of HUVECs were also assessed by cell wound healing assay, so as to discover the possible role of notch1 signaling pathway in the angiogenesis of human placenta. The results showed that angiogenic ability of HUVECs was seriously reduced under hypoxic conditions. The m RNA and protein levels of Notch1/Dell4/Jagged1 were decreased in the hypoxic group compared to the control one. In addition, the migration capability of HUVECs was significantly obstructed when treated with DAPT and under hopoxic condition, but promoted when treated with JAG-1. The above results demonstrate that hypoxia downregulates the angiogenesis in human placenta via Notch1 signaling pathway.

Acupuncture inhibits Notch1 and Hes1 protein expression in the basal ganglia of rats with cerebral hemorrhage

Notch pathway activation maintains neural stem cells in a proliferating state and increases nerve repair capacity. To date, studies have rarely focused on changes or damage to signal transduc- tion pathways during cerebral hemorrhage. Here, we examined the effect of acupuncture in a rat model of cerebral hemorrhage. We examined four groups： in the control group, rats received no treatment. In the model group, cerebral hemorrhage models were established by infusing non-hep-arinized blood into the Brain. In the acupuncture group, modeled rats had Baihui （DU20） and Qubin （GBT） acupoints treated once a day for 30 minutes. In the DAPT group, modeled rats had 0.15 μg/mL DAPT solution （10 mL） infused into the brain. Immunohistochemistry and western blot results showed that acupuncture effectively inhibits Notch 1 and Hesl protein expression in rat basal ganglia. These inhibitory effects were identical to DAPT, a Notch signaling pathway inhibitor. Our results suggest that acupuncture has a neuroprotective effect on cerebral hemorrhage by in- hibiting Notch-Hes signaling pathway transduction in rat basal ganglia after cerebral hemorrhage.

Down-regulation of pancreatic transcription factors and incretin receptors in type 2 diabetes

Type 2 diabetes is one of the most prevalent and serious metabolic diseases.Under diabetic conditions,chronic hyperglycemia and subsequent induction of oxidative stress deteriorate pancreaticβ-cell function,which leads to the aggravation of type 2 diabetes.Although such phenomena are well known as glucose toxicity,its molecular mechanism remains unclear.In this review article,we describe the possible molecular mechanism forβ-cell dysfunction found in type 2 diabetes,focusing on(1)oxidative stress,(2)pancreatic transcription factors(PDX-1 and MafA)and(3)incretin receptors(GLP-1 and GIP receptors).Under such conditions,nuclear expression levels of PDX-1 and MafA are decreased,which leads to suppression of insulin biosynthesis and secretion.In addition,expression levels of GLP-1 and GIP receptors are decreased,which likely contributes to the impaired incretin effects found in diabetes.Taken together,it is likely that downregulation of pancreatic transcription factors(PDX-1and MafA)and down-regulation of incretin receptors(GLP-1 and GIP receptors)explain,at least in part,the molecular mechanism forβ-cell dysfunction found in type 2 diabetes.

Hes1,an important gene for activation of hepatic stellate cells,is regulated by Notch1 and TGF-β/BMP signaling

AIM:To determine the role of Notch1 and Hes1 in regulating the activation of hepatic stellate cells(HSCs) and whether Hes1 is regulated by transforming growth factor(TGF)/bone morphogenetic protein(BMP) signaling.METHODS:Immunofluorescence staining was used to detect the expression of desmin,glial fibrillary acidic protein and the myofibroblastic marker α-smooth muscle actin(α-SMA) after freshly isolated,normal rat HSCs had been activated in culture for different numbers of days(0,1,3,7 and 10 d).The expression of α-SMA,collagen1α2(COL1α2),Notch receptors(Notch1-4),and the Notch target genes Hes1 and Hey1 were analyzed by reverse transcriptase-polymerase chain reaction.Luciferase reporter assays and Western blot were used to study the regulation of α-SMA,COL1α1,COL1α2 and Hes1 by NICD1,Hes1,CA-ALK3,and CA-ALK5 in HSC-T6 cells.Moreover,the effects of inhibiting Hes1 function in HSC-T6 cells using a Hes1 decoy were also investigated.RESULTS:The expression of Notch1 and Hes1 m RNAs was significantly down-regulated during the culture of freshly isolated HSCs.In HSC-T6 cells,Notch1 inhibited the promoter activities of α-SMA,COL1α1 and COL1α2.On the other hand,Hes1 enhanced the promoter activities of α-SMA and COL1α2,and this effect could be blocked by inhibiting Hes1 function with a Hes1 decoy.Furthermore,co-transfection of pc DNA3-CAALK3(BMP signaling activin receptor-like kinase 3) and pc DNA3.1-NICD1 further increased the expression of Hes1 compared with transfection of either vector alone in HSC-T6 cells,while pc DNA3-CA-ALK5(TGF-β signaling activin receptor-like kinase 5) reduced the effect of NICD1 on Hes1 expression.CONCLUSION:Selective interruption of Hes1 or maintenance of Hes1 at a reasonable level decreases the promoter activities of α-SMA and COL1α2,and these conditions may provide an anti-fibrotic strategy against hepatic fibrosis.