ATP-MgCl2对大鼠缺血再灌注肾脏损伤保护作用的研究

目的探讨三磷酸腺苷-氯化镁(ATP-MgCl2)对缺血再灌注(ischemic-reperfusion,I/R)损伤大鼠肾脏是否具有保护作用及对肾组织血管内皮生长因子-A(vascular endothelial growth factor-A,VEGF-A)和中性粒细胞明胶酶相关脂质运载蛋白(neutrophil gelatinase-asso-ciated lipocalin,NGAL)mRNA表达的影响。方法将42只健康雄性Wistar大鼠随机分为3组:假手术组(S组)、模型组(M组)和ATP-MgCl2组(A组)。检测各组大鼠缺血再灌注后2、6、12h血清肌酐(Scr)和尿素氮(Bun)的水平,肾组织病理学变化以及肾组织VEGF-A和NGAL mRNA的表达。结果M组和A组大鼠肾脏缺血再灌注后各时间段的Scr、Bun水平均高于S组(P<0·05和P<0·01)。A组再灌注2、6、12h后的Scr、Bun水平明显低于M组(P<0·05)。与M组相比,A组再灌注后肾脏组织的NGAL mRNA表达下降,VEGF-A mRNA表达增高(P<0·05)。A组与M组相比肾脏组织的病理改变有明显改善(P<0·01)。结论ATP-MgCl2对大鼠肾脏缺血再灌注损伤具有保护作用,并能影响VEGF-A和NGAL mRNA的表达,其机制可能与提高机体内ATP水平有关。     

Familial prevalence of uterine fibroids is associated with distinct clinical and molecular features

BACKGROUND: Although uterine fibroids are very common, their pathogenesis and clinical behaviour are poorly understood. Since they may be prevalent in some families, we investigated whether such a prevalence was associated with distinctive clinical and molecular features. METHODS: A case-control questionnaire study of 300 multi-ethnic women with uterine fibroids at a London university hospital was undertaken, with review of case notes and immunohistochemical determination of vascular endothelial growth factor (VEGF-A) in fibroids. RESULTS: When compared with families with sporadic fibroids, familial prevalence of fibroids was associated with a higher incidence of abdominal swelling (59.1% versus 41.6%; P=0.037), menorrhagia (84.4% versus 51.9%; P=0.042), dysmenorrhoea (64.4% versus 46.3%; P=0.004), dyspareunia (43.2% versus 27.9%; P=0.012) and family history of cancers (52.3% versus 32.4%; P<0.01). The fibroids were also more multiple (mean +/- SEM: 7 +/- 0.86 versus 3 +/- 0.42; P<0.011) and strong VEGF-A expression in fibroids was more common in the familial group (64% versus 28%). Racial distribution was the same in both groups (blacks 49%, whites 33.4%, others 18.6%). CONCLUSIONS: Familial prevalence of uterine fibroids is associated with distinct clinical and molecular features that differ from those found when fibroids occur sporadically in families.     

IL-33 receptor ST2 deficiency attenuates renal ischaemia–reperfusion injury in euglycaemic,but not streptozotocin-induced hyperglycaemic mice

Aim

Kidney hypoxia can predispose to the development of acute and chronic renal failure in diabetes. Ischaemia–reperfusion injury (IRI) causes inflammation, and diabetes is known to exacerbate this inflammatory response in the kidney, whereas alarmin IL-33 could act as an innate immune mediator during kidney IRI. Thus, the present study examined the impact of genetic IL-33 receptor ST2 deficiency (ST2?/?) on renal IRI in euglycaemic and hyperglycaemic mice.

Inhibition of the liver expression of arylalkylamine N-acetyltransferase increases the expression of angiogenic factors in cholangiocytes

Background and aims

Reduction of biliary serotonin N-acetyltransferase (AANAT) expression and melatonin administration/secretion in cholangiocytes increases biliary proliferation and the expression of SR, CFTR and Cl^–/HCO₃^– AE2. The balance between biliary proliferation/damage is regulated by several autocrine neuroendocrine factors including vascular endothelial growth factor-A/C (VEGF-A/C). VEGFs are secreted by several epithelia, where they modulate cell growth by autocrine and paracrine mechanisms. No data exists regarding the effect of AANAT modulation on the expressions of VEGFs by cholangiocytes.

Methods

In this study, we evaluated the effect of local modulation of biliary AANAT expression on the cholangiocytes synthesis of VEGF-A/C.

Results

The decrease in AANAT expression and subsequent lower melatonin secretion by cholangiocytes was associated with increased expression of VEGF-A/C. Overexpression of AANAT in cholangiocyte lines decreased the expression of VEGF-A/C.

Conclusions

Modulation of melatonin synthesis may affect the expression of VEGF-A/C by cholangiocytes and may modulate the hepatic microvascularization through the regulation of VEGF-A/C expression regulating biliary functions.     

Tumor Specific VEGF-A and VEGFR2/KDR Protein are Co-expressed in Breast Cancer

Angiogenesis is a prognostic indicator in primary breast cancer regulated by specific angiogenic factors and their receptors. Vascular endothelial growth factor-A (VEGF-A), so far considered the most important, acts through dimerization of the receptor VEGFR2/KDR within the receptor tyrosine kinase family of VEGF receptors. In order to study the interplay between VEGF-A and VEGFR2/KDR in breast cancer we evaluated their expression by immunohistochemistry in 102 breast cancers organized in a tumor tissue array system allowing semi-quantitative evaluation of cytoplasmatic staining intensity. In addition, VEGF-A165 was analyzed by an enzyme immuno assay (ELISA) in protein extracts prepared from frozen tissue from 98 of 102 tumors included in the array. Cytoplasmatic staining of VEGF of varying intensity was observed in all samples and correlated with the ELISA results of VEGF content (p = 0.007). Interestingly, VEGFR2/KDR expression correlated with VEGF expression using immunohistochemistry, indicating that VEGF and VEGFR2/KDR may be co-expressed in breast cancer. Furthermore, high levels of VEGF-A165 in the protein extracts was associated with impaired short time survival but not long term survival whereas immunohistochemically assessed VEGF and VEGFR2/KDR were not significantly associated with survival. In summary, immunohistochemically based analysis of VEGF using a tumor tissue array system seems to be a useful method for VEGF quantification in breast cancer here validated using an ELISA based method. The tumor tissue array system enables opportunities of simultaneous analysis of markers engaged in angiogenesis justifying further studies using larger series of tumors.     

Serum Matrix Metalloprotease-1 and Vascular Endothelial Growth Factor–A Predict Cardiac Allograft Rejection

Cardiac allograft rejection is currently diagnosed from endomyocardial biopsies (EMB) that are invasive and impractical to repeat. A serological marker could facilitate rejection monitoring and minimize EMB-associated risks. We investigated the relation of serum matrix metalloprotease (MMP)-1 and vascular endothelial growth factor (VEGF)-A concentrations to cardiac allograft rejection, using 1176 EMBs and serum samples obtained from 208 recipients. Acute cellular rejection was diagnosed in 186 EMBs. Mean week 1 and week 2 serum MMP-1 concentrations predicted rejection (p = 0.001, AUC = 0.80). At the optimal cut-off level of ≥7.5 ng/mL, MMP-1 predicted rejection with 82% sensitivity and 72% specificity. Initial serum MMP-1 <5.3 ng/mL (lowest quartile) was associated with rejection-free outcome in 80% of patients. Both MMP-1 (p < 0.001, AUC = 0.67–0.75) and VEGF-A (p < 0.01, AUC = 0.62–0.67) predicted rejection on the next EMB, while rejection at EMB was identified only by VEGF-A (p < 0.02, AUC = 0.70–0.77). Patients receiving combined cyclosporine-A and everolimus had the lowest serum MMP-1 concentrations. While serum MMP-1 predicts rejection-free outcome and VEGF-A identifies rejection on EMB, both markers predict rejection in follow-up of cardiac transplant recipients. Combination of serum MMP-1 and VEGF-A concentration may be a noninvasive prognostic marker of cardiac allograft rejection, and could have important implications for choice of surveillance and immunosuppression protocols.     

Impact of weight loss on circulating IL-1, IL-6, IL-8, TNF-alpha, VEGF-A, VEGF-C and midkine in gastroesophageal cancer patients

OBJECTIVE: Proinflammatory cytokines are involved in cancer-related weight loss, but the involvement of VEGF-A, VEGF-C, IL-8 and midkine in gastroesophageal cancer patients remains unknown. DESIGN AND METHODS: Serum IL-1, IL-6, IL-8, TNF-alpha, VEGF-A, VEGF-C, and midkine were evaluated in 96 cancer patients and 42 controls using ELISAs and were related to the occurrence of weight loss, patient's age, gender and BMI, cancer TNM status and blood cell counts. RESULTS: All cytokines were elevated in cancer patients with further up-regulation of IL-6, IL-8, midkine and VEGF-A in cachexia. Underweight, midkine and VEGF-A were found independent indicators of weight loss. Primary tumor seems to be a major source of pro-cachectic cytokines, yet neutrophils and platelets also contribute to cytokine elevation. CONCLUSIONS: IL-6 and IL-8, and probably midkine and VEGF-A, appear to participate in the development of cancer-related cachexia in gastroesophageal malignancies, although a detailed mechanism underlying cytokine involvement needs to be elucidated.     

miR-874 functions as a tumor suppressor by inhibiting angiogenesis through STAT3/VEGF-A pathway in gastric cancer

MicroRNAs are endogenously expressed, small non-coding RNAs that regulate gene expression by targeting mRNAs for translational repression or degradation. Our previous studies indicated that miR-874 played a suppressive role in gastric cancer (GC) development and progression. However, the role of miR-874 in tumor angiogenesis and the mechanisms underlying its function in GC remained to be clarified. Here, gain- and loss-of-function assays demonstrated that miR-874 inhibited the tumor angiogenesis of GC cells in vitro and in vivo. Through reporter gene and western blot assays, STAT3 was shown to be a direct target of miR-874. Overexpression of STAT3 rescued the loss of tumor angiogenesis caused by miR-874. Conversely, the STAT3-shRNA attenuated the increased tumor angiogenesis caused by the miR-874-inhibitor. Furthermore, the levels of miR-874 were inversely correlated with those of STAT3 protein in GC tissues. Taken together, these findings indicate that down-regulation of miR-874 contributes to tumor angiogenesis through STAT3 in GC, highlighting the potential of miR-874 as a target for human GC therapy.