Protective Effect of Catalpol on Myocardium in Rats with Isoprenaline-Induced Myocardial Infarcts via Angiogenesis through Endothelial Progenitor Cells and Notch1 Signaling Pathway

Protective effect of catalpol on myocardium was studied in relation to endothelial progenitor cells, Notch1 signaling pathway and angiogenesis in rats with isoprenaline (INN)-induced acute myocardial infarcts. To analyze the pathological status and impact of catalpol on the rats, 3 weeks after intragastric gavage, the animals were verified for myocardial infarcts with electrocardiogram and measured for enzyme activity of lactate dehydrogenase (LDH), malondialdehyde (MDA), creatine kinase (CK) and superoxide dismutase (SOD) in myocardium, and further analyzed using HE and TTC staining, as well as visual examination of infarct area. Flow cytometry study of endothelial progenitor cells (EPCs) indicated that the EPCs were mobilized during infarction. The roles of Notch1 signaling pathway in angiogenesis of the infracted animals were studied using immunohistochemistry analysis of RBPjκ and Western blot analysis of Notch1 and Jagged1. Our results obtained from the rats treated with catalpol, positive drug and control showed that catalpol could protect rats from infarction probably by mobilization of EPCs and activation of Notch1 signaling pathway.

Negative effects of Notch1 on the differentiation of muscle-derived stem cells into neuronal-like cells

We cultured rat muscle-derived stem cells in medium containing nerve growth factor and basic fi-broblast growth factor to induce neuronal-like cell differentiation.Immunocytochemical staining and reverse transcription-PCR showed that the differentiated muscle-derived stem cells exhibited processes similar to those of neuronal-like cells and neuron-specific enolase expression,but Notch1 mRNA and protein expression was decreased.Down-regulation of Notch1 expression may facilitate neuronal-like cell differentiation from muscle-derived stem cells.

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.

Role of the Notch Signaling Pathway in Fibrosis of Denervated Skeletal Muscle

In order to investigate the role of the Notch signaling pathway in skeletal muscle fibrosis after nerve injury, 60 Sprague-Dawley rats were selected and divided randomly into a control and two experimental groups. Group A served as controls without any treatment. Rats in groups B were injected intraperitoneally with 0.2 mL PBS and those in group C were injected intraperitoneally with 0.2 mL PBS+100 ymol/L, 0.2 mL N-[N-(3,5-difluorophenacetyl)-l-alanyl]- S-phenylglycine t-butyl ester (DAPT, a gamma-secretase inhibitor that suppresses Notch signaling) respectively, on postoperative days 1, 3, 7, 10, and 14 in a model of denervation-induced skeletal muscle fibrosis by right sciatic nerve transection. Five rats from each group were euthanized on postoperative days 1, 7, 14, and 28 to collect the right gastrocnemii, and hematoxylin and eosin (HE) staining, immunohistochemistry test, real-time PCR, and Western blotting were performed to assess connective tissue hyperplasia and fibroblast density as well as expression of Notch 1, Jagged 1, and Notch downstream molecules Hes 1 and collagen I (COL I) on day 28. There was no significant difference in HE-stained fibroblast density between group B and C on postoperative day 1. However, fibroblast density was significantly higher in group B than in group C on postoperative days 7, 14, and 28. Notch 1, Jagged 1, Hes 1, and COL I proteins in the gastrocnemius were expressed at very low levels in group A but at high levels in group B. Expression levels of these proteins were significantly lower in group C than in group B (P<0.05), but they were higher in group C than in group A (P<0.05) on postoperative day 28. We are led to conclude that locking the Notch signaling pathway inhibits fibrosis progression of denervated skeletal muscle. Thus, it may be a new approach for treatment of fibrosis of denervated skeletal muscle.

小鼠骨髓基质细胞Kusa-A1成骨分化中CBF1的作用

目的揭示CBF1在骨髓基质细胞Kusa-A1成骨分化过程中的作用。方法采用基因转染法建立CBF1稳定过表达细胞系Kusa-A1/CBF1,检测其成骨活性。指标包括细胞钙沉积能力、碱性磷酸酶活性、体外钙化结节(CN)形成、实时PCR测定细胞骨钙素(OC)和骨桥蛋白(OPN)基因表达、蛋白印迹检测细胞RANKL蛋白。最后用报告基因法检测CBF1对HES1启动子活性的影响。结果经RT-PCR和Western blot鉴定,Kusa-A1/CBF1细胞建立成功。与对照细胞系Kusa-A1/host相比,Kusa-A1/CBF1细胞的钙沉积能力、CN形成能力均显著提高;Kusa-A1/CBF1细胞OC和OPN基因表达和RANKL蛋白水平明显高于对照细胞。瞬时转染Notch的细胞内结构域NICD促进HES1的启动子活性,这一作用被CBF1强烈抑制。结论CBF1可以促进Kusa-A1的成骨分化,该作用至少部分是通过影响Notch信号实现的。

Oncogenic potential of IDH1R132C mutant incholangiocarcinoma development in mice

AIM: To investigate whether IDH1R132 C mutant in combination with loss of p53 and activated Notch signaling promotes intrahepatic cholangiocarcinoma(ICC) development.METHODS: We applied hydrodynamic injection and sleeping beauty mediated somatic integration to induce loss of p53(via sh P53), activation of Notch [via intracellular domain of Notch1(NICD)] and/or overexpression of IDH1R132 C mutant together with the sleeping beauty transposase into the mouse liver. Specifically, we co-expressed sh P53 and NICD(sh P53/NICD, n = 4), sh P53 and IDH1R132C(sh P53/IDH1R132 C, n = 3), NICD and IDH1R132C(NICD/IDH1R132 C, n = 4), as well as NICD, sh P53 and IDH1R132C(NICD/sh P53/IDH1R132 C, n = 9) in mice. Mice were monitored for liver tumor development and euthanized at various time points. Liver histology was analyzed by hematoxylin and eosin staining. Molecular features of NICD/sh P53/IDH1R132 C ICC tumor cells were characterized by Myc tag, Flag tag, Ki-67, p-Erk and p-AKT immunohistochemical staining. Desmoplastic reaction in tumor tissues was studied by Picro-Sirius red staining.RESULTS: We found that co-expression of sh P53/NICD, sh P53/IDH1R132 C or NICD/IDH1R132 C did not lead to liver tumor formation. In striking contrast, coexpression of NICD/sh P53/IDH1R132 C resulted in ICC development in mice(P < 0.01). The tumors could be identified as early as 12 wk post hydrodynamic injection. Tumors rapidly progressed, and by 18 wk post hydrodynamic injection, multiple cystic lesions could be identified on the liver surface. NICD/sh P53/IDH1R132 C liver tumors shared multiple histological features of human ICCs, including hyperplasia of irregular glands. Importantly, all tumor cells were positive for the biliary epithelial cell marker cytokeratin 19. Extensive collagen fibers could be visualized in tumor tissues using Sirus red staining, duplicating the desmoplastic reaction observed in human ICC. Tumors were highly proliferative and expressed ectopically injected genes. Together these studies supported that NICD/sh P53/IDH1R132 C liver tumors were indeed ICCs. Finally, no p-AKT or p-ERK positive staining was observed, suggesting that NICD/sh P53/IDH1R132 C driven ICC development was independent of AKT/m TOR and Ras/MAPK signaling cascades. CONCLUSION: We have generated a simple, nongermline murine ICC model with activated Notch, loss of p53 and IDH1R132 C mutant. The study supported the oncogenic potential of IDH1R132 C.

Strawberry Notch 1 (SBN01) promotes proliferation of spermatogonial stem cells via the noncanonical Wnt pathway in mice

While it is known that spermatogonial stem cells (SSCs) initiate the production of male germ cells, the mechanisms of SSC self-renewal, proliferation, and differentiation remain poorly understood. We have previously identified Strawberry Notch 1 (SBN01), a vertebrate strawberry notch family protein, in the proteome profile for mouse SSC maturation and differentiation, revealing SBN01 is associated with neonatal testicular development. To explore further the location and function of SBN01 in the testes, we performed Sbnol gene knockdown in mice to study the effects of SBN01 on neonatal testicular and SSC development. Our results revealed that SBN01 is required for neonatal testicular and SSC development in mice. Particularly, in vitro Sbnol gene knockdown with morpholino oligonucleotides caused a reduction of SSCs and inactivation of the noncanonical Wnt pathway, through Jun N-terminal kinases. Our study suggests SBN01 maintains SSCs by promoting the noncanonical Wnt pathway.

Brucine Inhibits Bone Metastasis of Breast Cancer Cells by Suppressing Jagged1/Notch1 Signaling Pathways

Objective： To examine the effects of brucine on the invasion, migration and bone resorption of receptor activator of nuclear factor-kappa B ligand（RANKL）-induced osteoclastogenesis. Methods： The osteoclastogenesis model was builded by co-culturing human breast tumor MDA-MB-231 and mouse RAW264.7 macrophages cells. RANKL（50 ng/m L） and macrophage-colony stimulating factor（50 ng/m L） were added to this system, followed by treatment with brucine（0.02, 0.04 and 0.08 mmol/L）, or 10 μmol/L zoledronic acid as positive control. The migration and bone resorption were measured by transwell assay and in vitro bone resorption assay. The protein expressions of Jagged1 and Notch1 were investigated by Western blot. The expressions of transforming growth factor-β1（TGF-β1）, nuclear factor-kappa B（NF-κB） and Hes1 were determined by enzyme-linked immunosorbent assay. Results： Compared with the model group, brucine led to a dose-dependent decrease on migration of MDA-MB-231 cells, inhibited RANKL-induced osteoclastogenesis and bone resorption of RAW264.7 cells（P 〈0.01）. Furthermore, brucine decreased the protein levels of Jagged1 and Notch1 in MDA-MB-231 cells and RAW264.7 cells co-cultured system as well as the expressions of TGF-β1, NF-κB and Hes1（P〈0.05 or P〈0.01）. Conclusion： Brucine may inhibit osteoclastogenesis by suppressing Jagged1/Notch1 signaling pathways.

骨保护素参与高磷诱导大鼠血管平滑肌细胞钙化调节的机制初探

目的以β-磷酸甘油诱导大鼠血管平滑肌细胞(VSMC)钙化模型为研究对象,初步探讨骨保护素(OPG)干预对VSMC钙化的影响及机制。方法体外分离培养大鼠主动脉VSMC。PBS为对照组,以10 mmol/Lβ-磷酸甘油诱导钙化10 d为钙化对照组,β-磷酸甘油诱导钙化同时予以剂量梯度(1、4、8μg/L)的OPG干预为OPG干预组。茜素红染色检测各组钙化结节形成情况。邻甲酚酞络合酮比色法检测细胞钙沉积含量。比色法测定碱性磷酸酶(ALP)活性。免疫蛋白印迹(Western blot)检测各组Notch1/RBP-JK通路蛋白的表达。结果茜素红染色显示,与钙化对照组比较,OPG干预组大鼠VSMC钙化结节明显减少,OPG干预组的钙含量、ALP活性均明显下降(均P<0.05),且有剂量依赖性。Westernblot结果显示,与钙化对照组比较,OPG干预组的Notch1、RBP-JK、Jagged1、Msx2蛋白表达水平明显下降(均P<0.05)。结论OPG可能通过下调Notch1/RBP-JK通路蛋白表达,参与大鼠VSMC钙化过程调节。

Novel molecular targets in hepatocellular carcinoma

Globally,hepatocellular carcinoma(HCC)is a leading cause of cancer and cancerrelated deaths.The therapeutic efficacy of locoregional and systemic treatment in patients with advanced HCC remains low,which results in a poor prognosis.The development of sorafenib for the treatment of HCC has resulted in a new era of molecular targeted therapy for this disease.However,the median overall survival was reported to be barely higher in the sorafenib treatment group than in the control group.Hence,in this review we describe the importance of developing more effective targeted therapies for the management of advanced HCC.Recent investigations of molecular signaling pathways in several cancers have provided some insights into developing molecular therapies that target critical members of these signaling pathways.Proteins involved in the Hedgehog and Notch signaling pathways,Polo-like kinase 1,arginine,histone deacetylases and Glypican-3 can be potential targets in the treatment of HCC.Monotherapy has limited therapeutic efficacy due to the development of inhibitory feedback mechanisms and induction of chemoresistance.Thus,emphasis is now on the development of personalized and combination molecular targeted therapies that can serve as ideal therapeutic strategies for improved management of HCC.

Alagille syndrome associated with total anomalous pulmonary venous connection and severe xanthomas:A case report

BACKGROUND Alagille syndrome(ALGS)is an autosomal dominant genetic disorder caused by mutations in the JAG1 or NOTCH2 gene.It is characterized by decreased intrahepatic bile ducts associated with a variety of abnormalities in many other organ systems,such as the cardiovascular,skeletal,and urinary systems.CASE SUMMARY We report a rare case of ALGS.A 1-month-old male infant presented with sustained jaundice and had a rare congenital heart disease:Total anomalous pulmonary venous connection(TAPVC).Sustained jaundice,particularly with cardiac murmur,caught our attention.Laboratory tests revealed elevated levels of alanine aminotransferase,aspartate aminotransferase,gamma-glutamyl transpeptidase,total bilirubin,and total bile acids,indicating serious intrahepatic cholestasis.Imaging confirmed the presence of butterfly vertebra at the seventh thoracic vertebra.This suggested ALGS,which was confirmed by genetic testing with a c.3197dupC mutation in the JAG1 gene.Ursodiol was administered immediately after confirmation of the diagnosis,and cardiac surgery was performed when the patient was 1.5 month old.He recovered well after treatment and was discharged at the age of 3 mo.At the age of two years,the patient returned to our clinic because multiple cutaneous nodules with xanthomas appeared,and their size and number increased over time.CONCLUSION We report a unique case of ALGS associated with TAPVC and severe xanthomas.This study has enriched the clinical manifestations of ALGS and emphasized the association between JAG1 gene and TAPVC.