Protein expression, biochemical pharmacology of signal transduction, and relation to intraocular pressure modulation by bradykinin B2 receptors in ciliary muscle
Autor: | Sharif, Najam A., Xu, Shouxi, Li, Linya, Katoli, Parvaneh, Kelly, Curtis R., Wang, Yu, Cao, Shutong, Patil, Rajkumar, Husain, Shahid, Klekar, Laura, Scott, Daniel |
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Jazyk: | angličtina |
Rok vydání: | 2013 |
Předmět: |
Time Factors
Receptor Bradykinin B2 Molecular Sequence Data CHO Cells Bradykinin Nitric Oxide Cricetulus Cricetinae Bradykinin B2 Receptor Antagonists Animals Humans Cyclooxygenase Inhibitors Amino Acid Sequence Calcium Signaling Phosphorylation Extracellular Signal-Regulated MAP Kinases Intraocular Pressure Ciliary Body Muscle Smooth Immunohistochemistry Matrix Metalloproteinases Macaca fascicularis Prostaglandins Rabbits Peptides Research Article Signal Transduction |
Zdroj: | Molecular Vision |
ISSN: | 1090-0535 |
Popis: | Purpose To examine the bradykinin (BK) B2-receptor system in human and monkey ciliary muscle (CM) using immunohistochemical techniques, and to pharmacologically characterize the associated biochemical signal transduction systems in human CM (h-CM) cells. BK-induced modulation of intraocular pressure (IOP) in pigmented Dutch-Belt rabbits and cynomolgus monkeys was also studied. Methods Previously published procedures were used throughout these studies. Results The human and monkey ciliary bodies expressed high levels of B2-receptor protein immunoreactivity. Various kinins differentially stimulated [Ca2+]i mobilization in primary h-CM cells (BK EC50=2.4±0.2 nM > Hyp3,β-(2-thienyl)-Ala5,Tyr(Me)8-(®)-Arg9)-BK (RMP-7) > Des-Arg9-BK EC50=4.2 µM [n=3–6]), and this was blocked by B2-selective antagonists, HOE-140 (IC50=1.4±0.1 nM) and WIN-63448 (IC50=174 nM). A phospholipase C inhibitor (U73122; 10–30 µM) and ethylene glycol tetraacetic acid (1–2 mM) abolished the BK-induced [Ca2+]i mobilization. Total prostaglandin (primarily PGE2) secretion stimulated by BK and other kinins in h-CM cells was attenuated by the cyclooxygenase inhibitors bromfenac and flurbiprofen, and by the B2-antagonists. BK and RMP-7 (100 nM) induced a twofold increase in extracellular signal-regulated kinase-1/2 phosphorylation, and BK (0.1–1 µM; at 24 h) caused a 1.4–3.1-fold increase in promatrix metalloproteinases-1–3 release. Topical ocular BK (100 µg) failed to alter IOP in cynomolgus monkeys. However, intravitreal injection of 50 µg of BK, but not Des-Arg9-BK, lowered IOP in rabbit eyes (22.9±7.3% and 37.0±5.6% at 5 h and 8 h post-injection; n=7–10). Conclusions These studies have provided evidence of a functional endogenously expressed B2-receptor system in the CM that appears to be involved in modulating IOP. |
Databáze: | OpenAIRE |
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