Expression of HER2 and bradykinin B_1 receptors in precursor lesions of gallbladder carcinoma

AIM： To determine the expression of HER2 and bradykinin B1 receptors （B1R） in the two pathogenic models of gallbladder cancer： the metaplasia dysplasia carcino ma and the adenoma carcinoma pathways.METHODS： Receptor proteins were visualized by immunohistochemistry on 5-μm sections of paraffin-embedded tissue. Expression of both receptors was studied in biopsy samples from 92 patients （6 males and 86 females; age ranging from 28 to 86 years, mean 56 years）. High HER2 expression in specimens was additionally investigated by fluorescence in situ hybridization. Cell proliferation in each sample was assessed by using the Ki-67 proliferation marker.RESULTS： HER2 receptor protein was absent in adenomas and in normal gallbladder epithelium. On the contrary, there was intense staining for HER2 on the basolateral membrane of epithelial cells of intestinal metaplasia （22/24; 91.7%） and carcinoma in situ （9/10; 90%）, the lesions that displayed a significantly high proliferation index. Protein up-regulation of HER2 in the epithelium with metaplasia or carcinoma in s/tu was not accompanied by HER2 gene amplification. A similar result was observed in invasive carcinomas （0/12）. The B1R distribution pattern mirrored that of HER2 except that B1R was additionally observed in the adenomas. The B1R appeared either as cytoplasmic dots or labeling on the apical cell membrane of the cells composing the epithelia with intestinal metaplasia （24/24; 100%） and carcinoma in situ （10/10; 100%） and in the epithelial cells of adenomas. In contrast, both HER2 （4/12; 33%） and B1R （1/12; 8.3%） showed a low expression in inva- sive gallbladder carcinomas.CONCLUSION： The up-regulation of HER2 and B1R in precursor lesions of gallbladder carcinoma suggests cross-talk between these two receptors that may be of importance in the modulation of cell proliferation in gallbladder carcinogenesis,

Down-regulation of Cardiac Bradykinin B2 Receptors and eNOs mRNA in Rats with Remnant Kidneys

The changes in the expression of cardiac bradykinin B2 receptors (BKB2Rs) and endogenous nitrix oxide synthase (eNOs) mRNA were studied in rats with remnant kidneys. Thirty-two rats were divided into sham-operated and experimental groups randomly (n=16 in each group). The remnant kidney model was established by 2-stage 5/6 nephrectomy. Blood pressure and serum Cr were measured before operation and 15, 30, 60, 120 days after 5/6 nephrectomy. Eight animals in each group were killed at the first month and 4th month after the operation. The expression of BKB2Rs and eNOs mRNAs was detected by using RT-real time PCR from isolated left ventricle, and their correlation was also analyzed. The results showed that blood pressure and serum Cr were increased significantly 15 days after 5/6 nephrectomy (both P<0.01), and the hypertension and azomia existed constantly till 120 days but had no significant fluctuation. Cardiac BKB2Rs and eNOs mRNA was declined time-dependently (both P<0.05). And there was a close positive correlation between cardiac BKB2Rs and eNOs mRNA (r=0.82, P<0.01). It was suggested that a significant chronic renal failure can be produced at least 15 days after 5/6 nephrotomy and can sustain more than 4 months. The expression of BKB2Rs and eNOs was down-regulated time-dependently in this model, and there was a significant correlation between them.

Pretreatment with simvastatin upregulates expression of BK-2R and CD11b in the ischemic penumbra of rats

Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductases, collectively known as statins, have been shown to minimize cerebral ischemic events in patients. We assessed the mechanisms of simvastatin pretreatment in preventing cerebral ischemia/reperfusion injury in rats using a model of middle cerebral artery occlusion（MCAO）.Rats were pretreated with simvastatin 14 days prior to MCAO induction. At 3, 24, and 48 hours after reperfusion,bradykinin levels in the ischemic penumbra were assayed by ELISA, mRNA levels of bradykinin B2 receptors（BK-2Rs） and CD11b were measured by fluorescent quantitative real-time PCR（RT-PCR）, and co-expression of microglia and BK-2Rs was determined by immunofluorescence. Simvastatin had no effect on bradykinin expression in the ischemic penumbra at any time point. However, the levels of BK-2R and CD11b mRNA in the ischemic penumbra,which were significantly decreased 3 hours after ischemia-reperfusion, were increased in simvastatin-pretreated rats.Moreover, the co-expression of BK-2Rs and microglia was confirmed by immunofluorescence analysis. These results suggest that the beneficial effects of simvastatin pretreatment before cerebral ischemia/reperfusion injury in rats may be partially due to increased expression of BK-2R and CD11b in the ischemic penumbra.