OBJECTIVE: Since the role of Ca2+ in angiogenesis is not fully understood, we investigated the effect of thapsigargin (TG: depletes intracellular Ca2+ pools) and other Ca2+ modulators [ionomycin, calcium ionophore A23187 and dibutyrylhydroquinone (DBHQ)] on in vitro angiogenesis by rat aortic rings. METHODS: Aortae from Sprague-Dawley rats were cut into 2-mm rings, embedded in a fibrin clot and cultured for 15 days in serum-free medium containing drugs and the microvessels counted. Rings were also pre-treated with TG and Ca2+ modulators for 1 h prior to embedding and culture. Viability was examined by the measurement of lactic acid dehydrogenase release. Rings were also treated with hydrocortisone and lavendustin A (a tyrosine kinase inhibitor), as positive controls. The effect of TG on the proliferation and migration of human umbilical artery endothelial cells (HUVECs) was studied in parallel. RESULTS: TG significantly inhibited microvessel formation and HUVEC proliferation and migration in a dose-dependent manner, all at <10 nmol/l, without affecting viability. In contrast, ionomycin, A23187 and DBHQ were cytotoxic at inhibitory concentrations. Continual exposure to hydrocortisone and lavendusin A also inhibited angiogenesis without affecting viability. CONCLUSION: Since low concentrations of TG deplete intracellular Ca2+ stores, it is concluded that these pools play a central role in mediating angiogenesis.
OBJECTIVE: Since the role of Ca2+ in angiogenesis is not fully understood, we investigated the effect of thapsigargin (TG: depletes intracellular Ca2+ pools) and other Ca2+ modulators [ionomycin, calcium ionophore A23187 and dibutyrylhydroquinone (DBHQ)] on in vitro angiogenesis by rat aortic rings. METHODS: Aortae from Sprague-Dawley rats were cut into 2-mm rings, embedded in a fibrin clot and cultured for 15 days in serum-free medium containing drugs and the microvessels counted. Rings were also pre-treated with TG and Ca2+ modulators for 1 h prior to embedding and culture. Viability was examined by the measurement of lactic acid dehydrogenase release. Rings were also treated with hydrocortisone and lavendustin A (a tyrosine kinase inhibitor), as positive controls. The effect of TG on the proliferation and migration of human umbilical artery endothelial cells (HUVECs) was studied in parallel. RESULTS:TG significantly inhibited microvessel formation and HUVEC proliferation and migration in a dose-dependent manner, all at <10 nmol/l, without affecting viability. In contrast, ionomycin, A23187 and DBHQ were cytotoxic at inhibitory concentrations. Continual exposure to hydrocortisone and lavendusin A also inhibited angiogenesis without affecting viability. CONCLUSION: Since low concentrations of TG deplete intracellular Ca2+ stores, it is concluded that these pools play a central role in mediating angiogenesis.
Authors: Yeon Hee Hwang; Ho Sun Song; Hee Rae Kim; Myoung Soo Ko; Jae Min Jeong; Yong Ho Kim; Jeong Soo Ryu; Uy Dong Sohn; Yoon-Myoung Gimm; Sung Ho Myung; Sang Soo Sim Journal: Korean J Physiol Pharmacol Date: 2011-10-31 Impact factor: 2.016