PDF(Pubmed)
Abstract：
Ticks are blood-feeding arthropods that require heme for their successful reproduction. During feeding they also acquire pathogens that are subsequently transmitted to humans, wildlife and/or livestock. Understanding the regulation of tick midgut is important for blood meal digestion, heme and nutrient absorption processes and for aspects of pathogen biology in the host. We previously demonstrated the activity of tick kinins on the cognate G protein-coupled receptor. Herein we uncovered the physiological role of the kinin receptor in the tick midgut. A fluorescently-labeled kinin peptide with the endogenous kinin 8 sequence (TMR-RK8), identical in the ticks Rhipicephalus microplus and R. sanguineus, activated and labeled the recombinant R. microplus receptor expressed in CHO-K1 cells. When applied to the live midgut the TMR-RK8 labeled the kinin receptor in muscles while the labeled peptide with the scrambled-sequence of kinin 8 (TMR-Scrambled) did not. The unlabeled kinin 8 peptide competed TMR-RK8, decreasing confocal microscopy signal intensity, indicating TMR-RK8 specificity to muscles. TMR-RK8 was active, inducing significant midgut peristalsis that was video-recorded and evaluated with video tracking software. The TMR-Scrambled peptide used as a negative control did not elicit peristalsis. The myotropic function of kinins in eliciting tick midgut peristalsis was established.
摘要：
蜱是以血液为食的节肢动物，需要血红素才能成功繁殖。在喂养过程中，它们还获得随后传播给人类的病原体，野生动物和/或牲畜。了解蜱中肠的调节对血粉消化很重要，血红素和营养吸收过程以及宿主病原体生物学方面。我们先前证明了蜱激肽对同源G蛋白偶联受体的活性。在这里，我们发现了tick中肠中激肽受体的生理作用。具有内源性激肽8序列的荧光标记的激肽（TMR-RK8），小蜱和血门的蜱相同，激活并标记在CHO-K1细胞中表达的重组R.microplus受体。当应用于活的中肠时，TMR-RK8标记了肌肉中的激肽受体，而具有激肽8的乱序序列的标记肽（TMR-乱序）则没有。未标记的激肽8竞争TMR-RK8，降低共聚焦显微镜信号强度，表明TMR-RK8对肌肉的特异性。TMR-RK8是活跃的,诱导显著的中肠蠕动，视频记录和评估与视频跟踪软件。用作阴性对照的TMR-Scrambled肽不引起蠕动。建立了激肽在引起蜱中肠蠕动中的肌力功能。
