Down-regulation of transforming growth factor β1/activin receptor-like kinase 1 pathway gene expression by herbal compound 861 is related to deactivation of LX-2 cells

AIM: To investigate the effect of herbal compound 861 (Cpd861) on the transforming growth factor-β1 (TGFβ1)/ activin receptor-like kinase 1 (ALK1, type Ⅰ receptor) signaling-pathway-related gene expression in the LX-2 cell line, and the inhibitory mechanism of Cpd861 on the activation of LX-2 cells. METHODS: LX-2 cells were treated with TGFβ1 (5 ng/mL) Cpd861 (0.1 mg/mL), TGFβ1 (5 ng/mL) plus Cpd861 (5 ng/mL) for 24 h to investigate the effect of Cpd861 on the TGFβ1/ALK1 pathway. Real-time PCR was performed to examine the expression of α-SMA (α-smooth muscle actin), ALK1, Id1 (inhibitor of differentiation 1). Western blotting was carried out to measure the levels of α-SMA and phosphorylated Smad1, and immunocytochemical analysis for the expression of α-SMA. RESULTS: In LX-2 cells, TGFβ1/ALK1-pathway-related gene expression could be stimulated by TGFβ1, which led to excessive activation of the cells. Cpd861 decreased the activation of LX-2 cells by reducing the expression of α-SMA mRNA and protein expression. This effect was related to inhibition of the above TGFβ1/ALK1-pathway- related expression of genes such as Id1 and ALK1, and phosphorylation of Smad1 in LX-2 cells, even with TGFβ1 co-treatment for 24 h. CONCLUSION: Cpd861 can restrain the activation of LX-2 cells by inhibiting the TGFβ1/ALK1/Smad1 pathway.

Role of activin receptor-like kinase 1 in vascular development and cerebrovascular diseases

Activin receptor-like kinase 1(ALK1)is a transmembrane serine/threonine receptor kinase of the transforming growth factor beta(TGFβ)receptor superfamily.ALK1 is specifically expressed in vascular endothelial cells,and its dynamic changes are closely related to the proliferation of endothelial cells,the recruitment of pericytes to blood vessels,and functional differentiation during embryonic vascular development.The pathophysiology of many cerebrovascular diseases is today understood as a disorder of endothelial cell function and an imbalance in the proportion of vascular cells.Indeed,mutations in ALK1 and its co-receptor endoglin are major genetic risk factors for vascular arteriovenous malformation.Many studies have shown that ALK1 is closely related to the development of cerebral aneurysms,arteriovenous malformations,and cerebral atherosclerosis.In this review,we describe the various roles of ALK1 in the regulation of angiogenesis and in the maintenance of cerebral vascular homeostasis,and we discuss its relationship to functional dysregulation in cerebrovascular diseases.This review should provide new perspectives for basic research on cerebrovascular diseases and offer more effective targets and strategies for clinical diagnosis,treatment,and prevention.

曲尼司特对高糖培养心肌成纤维细胞增殖及表型转化的影响

目的探讨曲尼司特对高糖培养大鼠心肌成纤维细胞增殖及表型转化的作用及可能机制。方法体外培养大鼠心肌成纤维细胞(CF)分为正常对照组(5.5 mmol·L-1葡萄糖)、高渗对照组(葡萄糖5.5 mmol·L-1+甘露醇25 mmol·L-1)、高糖组(25 mmol·L-1葡萄糖)、曲尼司特干预组(葡萄糖25 mmol·L-1+曲尼司特50,100和200μmol·L-1)及活化素受体样激酶7(ALK7)阻断剂组(葡萄糖25 mmol·L-1+SB431542 10μmol·L-1)。各组细胞分别与不同药物孵育48 h后,采用MTT法检测CF存活,免疫荧光法检测CF表型转化,Western蛋白印迹法检测CF特异性蛋白1(FSP-1)、α平滑肌动蛋白(α-SMA)、转化生长因子β1(TGF-β1)和ALK7的蛋白表达。结果与正常对照组比较,高糖组CF A492 nm明显升高(P<0.01),FSP-1表达明显减少(P<0.01),α-SMA表达明显增多(P<0.01),TGF-β1和ALK7表达增多(P<0.01),而高渗对照组以上指标均无显著性差异。与高糖组比较,应用ALK7阻断剂SB431542及不同浓度曲尼司特同步干预后,均可使CF A492 nm显著降低(P<0.05),FSP-1表达明显增多(P<0.05),α-SMA表达明显减少(P<0.01),TGF-β1表达明显减少(P<0.05),ALK7表达减少(P<0.05)。结论曲尼司特可抑制高糖诱导的CF增殖及表型转化,其机制可能与下调ALK7的表达有关。

四氯二苯对二恶英和地塞米松诱导小鼠腭裂及转化生长因子-β3和受体活化样激酶5的表达

目的建立四氯二苯对二恶英（TCDD）和地塞米松（DEX）联合诱导C57BL/6J小鼠腭裂模型,并在腭发育关键时期检测转化生长因子-β3（TGF-β3）和受体活化样激酶5（Alk5）基因的表达,探讨TCDD和DEX联合诱导胎鼠腭裂与TGF-β3和Alk5的相关性。方法在小鼠GD10～GD12,实验组小鼠连续3d胃饲TCDD和腹腔注射DEX,空白对照组不做处理,于GD17.5体视显微镜下检测各组腭裂发生率,并于GD13.5、GD14.5、GD15.5分别剪取胎鼠腭突提取RNA,采用实时荧光定量聚合酶链反应检测TGF-β3和Alk5基因表达。结果采用TCDD和DEX联合致畸,可诱导C57BL/6J胎鼠形成100%腭裂,建立了一种稳定适合分子生物学研究的腭裂动物模型。GD13.5时TGF-β3和Alk5基因表达水平在实验组与空白对照组之间差异均无统计学意义（P〉0.05）,在GD14.5、GD15.5实验组TGF-β3表达均降低（P〈0.05）,而Alk5表达均升高（P〈0.05）。结论 TCDD和DEX联合作用可诱导C57BL/6J胎鼠形成稳定腭裂,在腭融合关键时期诱导TGF-β3表达下降,Alk5表达升高,与腭裂的发生具有一定的相关性。

Gastric angiodysplasia in a hereditary hemorrhagic telangiectasia type 2 patient

Hereditary hemorrhagic telangiectasia(HHT)is a rare autosomal-dominantly inherited disease that occurs in approximately one in 5000 to 8000 people.Clinical diagnosis of HHT is made when a person presents three of the following four criteria:family history,recurrent nosebleeds,mucocutaneous telangiectasis,and arteriovenous malformations(AVM)in the brain,lung,liver and gastrointestinal(GI)tract.Although epistaxis is themost common presenting symptom,AVMs affecting the lungs,brain and GI tract provoke a more serious outcome.Heterozygous mutations in endoglin,activin receptor-like kinase 1(ACVRL1;ALK1),and SMAD4,the genes involved in the transforming growth factor-βfamily signaling cascade,cause HHT.We report here the case of a 63 year-old male patient who presented melena and GI bleeding episodes,proven to be caused by bleeding from multiple gastric angiodysplasia.Esophagogastroduodenoscopy revealed multiple angiodysplasia throughout the stomach.Endoscopic argon plasma coagulation was performed to control bleeding from a gastric angiodysplasia.The patient has been admitted several times with episodes of hemoptysis and hematochezia.One year ago,the patient was hospitalized due to right-sided weakness,which was caused by left basal ganglia hemorrhage as the part of HHT presentation.In family history,the patient's mother and elder sister had died,due to intracranial hemorrhage,and his eldest son has been suffered from recurrent epistaxis for 20 years.A genetic study revealed a mutation in exon 3 of ALK1(c.199C>T;p.Arg67Trp)in the proband and his eldest son presenting epistaxis.

GDF11通过上调ABCA1表达促进小鼠体内胆固醇逆转运

目的研究生长分化因子11（GDF11）对巨噬细胞胆固醇逆转运的影响,并探究GDF11发挥作用的具体机制。方法提取小鼠腹腔巨噬细胞后给予氧化型低密度脂蛋白（ox-LDL）、GDF11和激活素受体样激酶7（ALK7）抑制剂SB431542孵育24 h。利用油红O染色观察细胞脂质蓄积,提取总m RNA和总蛋白后,利用realtime PCR和Western blot检测GDF11、三磷酸腺苷结合盒转运体A1（ABCA1）和三磷酸腺苷结合盒转运体G1（ABCG1）的m RNA和蛋白表达水平。给予小鼠腹腔注射外源GDF11,提取腹腔巨噬细胞用3H标记的胆固醇孵育后注射回小鼠腹腔内,每8 h收集一次小鼠粪便,48 h后收集小鼠肝脏和血液样本,检测样本3H含量,计算胆固醇逆转运水平。结果 ox-LDL孵育24 h显著诱导巨噬细胞内脂质蓄积,同时抑制GDF11 m RNA及蛋白的表达。GDF11处理能有效抑制ox-LDL诱导的巨噬细胞脂质蓄积,同时显著诱导ABCA1 m RNA及蛋白的表达。经外源补充GDF11后显著提高小鼠体内胆固醇逆转运水平。GDF11孵育巨噬细胞后,在给予巨噬细胞ALK7抑制剂SB431542孵育后,GDF11对ox-LDL诱导细胞内脂质蓄积的抑制作用被拮抗,对ABCA1表达的调控作用也被抑制。结论 GDF11通过ALK7调节ABCA1的表达,从而促进巨噬细胞胆固醇逆转运。

Correlation between expression of two transforming growth factor-beta 1 receptors and microvascular density in a rat model of cerebral ischemia and reperfusion injury

The effects of transforming growth factor-β1 （TGF-β1） are currently controversial. Whether TGF-β1 promotes or inhibits revascularization under different conditions remains poorly understood. Based on previous studies, the current experiment established rat models of cerebral ischemia and reperfusion injury （IRI）, and demonstrated that pathological and functional damage was also increased after IRI. The most serious damage was observed at 3 days after reperfusion, at which time microvascular density fell to its lowest level. Soon afterwards, microvascular density increased, new collateral circulation was gradually established at 4 to 7 days after reperfusion, and pathological damage and neurological deficits were improved. TGF-β1, activin receptor-like kinase 5 （ALK5） mRNA and protein expression levels increased gradually over time. In contrast, ALK1 mRNA and protein expression decreased over the same period. A significant negative correlation was detected between microvascular density and expression of the ALK5 gene transcript. There was no correlation between microvascular density and ALK1 gene transcriptional expression following cerebral IRI in a rat model. These findings suggest that ALK5, rather than ALK1, is the critical receptor in the TGF-β1 signal pathways after cerebral IRI.

Pulmonary arterial hyper-tension in a patient with hereditary hemorrhagic telangiectasia and family gene analysis:A case report

BACKGROUND Hereditary hemorrhagic telangiectasia(HHT)is a rare autosomal dominant genetic disease.Very few patients suffering from HHT present with associated pulmonary arterial hypertension(PAH),which may result in a poor prognosis.Here,we report a case of HHT with PAH.The patient’s clinical manifestations and treatment as well as genetic analysis of family members are reviewed,in order to raise awareness of this multimorbidity.CASE SUMMARY A 45-year-old Chinese woman was admitted to the hospital to address a complaint of intermittent shortness of breath,which had lasted over the past 2 years.She also had a 30-year history of recurrent epistaxis and 5-year history of anemia.She reported that the shortness of breath had aggravated gradually over the 2 years.Physical examination discovered anemia and detected gallop rhythm in the precordium.Chest computerized tomography and cardiac ultrasound demonstrated PAH and hepatic arteriovenous malformation.The formal clinical diagnosis was HHT combined with PAH.The patient was treated with ambrisentan and her condition improved for a time.She died half a year after the diagnosis.Genetic testing revealed the patient and some family members to carry an activin A receptor-like type 1 mutation(c.1232G>A,p.Arg411Gln);the family was thus identified as an HHT family.CONCLUSION We report a novel gene mutation(c.1232G>A,p.Arg411Gln)in a Chinese HHT patient with PAH.

Effect of vitamin B12 on cleft palate induced by 2,3.7.8-tetrachlorodibenzo-p-dioxin and dexamethasone in mice

The purpose of this study was to investigate the effect of vitamin B12 on palatal development by co-administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin （TCDD） and dexamethasone （DEX）. We examined the morphological and histological features of the palatal shelf and expression levels of key signaling molecules （trans- forming growth factor-β3 （TGF-β3） and TGF-β3 type I receptor （activin receptor-like kinase 5, ALK5）） during pala- togenesis among a control group （Group A）, TCDD＋DEX exposed group （Group B）, and TCDD＋DEX＋vitamin B12 exposed group （Group C）. While we failed to find that vitamin B12 decreased the incidence of cleft palate induced by TCDD＋DEX treatment, the expression levels of key signaling molecules （TGF-~3 and ALK5） during palatogenesis were significantly modulated. In TCDD＋DEX exposed and TCDD＋DEX＋vitamin B12 exposed groups, palatal shelves could not contact in the midline due to their small sizes. Our results suggest that vitamin B12 may inhibit the expression of some cleft palate inducers such as TGF-β3 and ALK5 in DEX＋TCDD exposed mice, which may be beneficial against palatogenesis to some degree, even though we were unable to observe a protective role of vitamin B12 in morphological and histological alterations of palatal shelves induced by DEX and TCDD.

Clinical phenotypes,ALK1 gene mutation and level of related plasma proteins in Chinese hereditary hemorrhagic telangiectasia

Background We determined the diagnosis of hereditary hemorrhagic telangiectasis (HHT) in a suspected HHT family,identified ALK1 gene mutation and established a gene diagnosis method of HHT. The level of related plasma proteins (transforming growth factor β and thrombomodulin) were also analyzed.Methods Bleeding history and family history were collected; Dilatant nasal mucosal capillaries in proband were observed under nasal cavity endoscope; exons 3,7,8 of ALK1 gene in proband and her family members were amplified with polymerase chain reaction (PCR), and the PCR products were analyzed. Using enzyme-linked immunosorbent assay (ELISA),plasma TGF-β1 and TGF-β2 concentrations were measured. Plasma thrombomodulin (TM) level was detected by Western blotting.Results Of all family members,four had epstaxis,two had evident telangiectases on skin or mucosa. Gene screening results showed that C to T substitution at position 1231 in exon 8 of ALK1 gene (CGG→TGG) existed in proband,her affected brother and their father. The mutation did not exist in proband’s sister-in-law and nephew. Plasma TGF-β1 concentrations in the affected HHT was 20538,17194,13131 pg/ml,while that of normal control and unaffected family members was 15950,20297,12836 pg/ml,respectively. Plasma TGF-β2 in HHT patients was 14502,9550,10592 and that of normal controls 8579,20297,7680 pg/ml respectively. Level of plasma TM was in HHT subjects significantly lower than in normal subjects.Conclusions Chinese HHT individuals have mutant ALK1 gene,a C1231T variation on exon 8 of ALK1 is responsible for HHT clinical phenotypes in this family. ALK1 gene analysis,together with special clinical phenotypes and family history,provides a reliable method in diagnosing HHT. In affected HHT subjects,plasma TGFβ levels were not obviously different from those of normal subject; while plasma TM concentration was significantly lower than that in normal subjects. The significance and mechanism remain to be elucidated.