M Horio1, A Ito, Y Matsuoka, T Moriyama, Y Orita, M Takenaka, E Imai. 1. School of Allied Health Sciences, Department of Internal Medicine and Therapeutics and. Faculty of Health and Sport Science, Osaka University School of Medicine, Suita, Osaka, Japan.
Abstract
BACKGROUND: In mammals, the renal medulla is in a hypertonic environment related to the renal concentrating mechanism. Renal cells accumulate osmolytes such as betaine to protect cells from the perturbing effect of high concentration of electrolytes. Hypertonicity-induced cell death and the effect of betaine were investigated in Madin Darby canine kidney (MDCK) cells. METHODS: Cell viability was detected by 3-(4,5-dimethylthiazo-2-yl)-2,5-diphenyl tetrazolium bromide assay. DNA fragmentation was determined by FACS analysis, terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) staining and agarose gel electrophoresis. Activities of caspase-1, -3, -8, and -9 were measured. RESULT: When the cells were exposed to 700 mOsm medium for 24 h, 40% of the cells were detached. TUNEL staining showed that about 20% of detached cells were apoptotic, indicating that both necrosis and apoptosis contributed to the hypertonicity-induced cell death in MDCK cells. DNA laddering was demonstrated in hypertonic cells. Caspase-3, -8, and -9 activities of the adherent cells exposed to 700 mOsm for 24 h increased approximately 20-, 3-, and 4-fold the value of isotonic cells, respectively. However, there was no significant change in caspase-1 activity. Addition of 1 mM betaine into the medium protected the cells against the hypertonicity-induced cytotoxicity and apoptosis. Betaine prevented the induction of caspase-3, -8, and -9 activities after hypertonic exposure to about 50%. CONCLUSIONS: The present study demonstrates that (i) apoptosis is involved in the hypertonicity-induced cell death in MDCK cells; (ii) caspase-3, -8, and -9 may contribute to the apoptosis; and (iii) betaine has protective effect on the hypertonicity-induced apoptosis.
BACKGROUND: In mammals, the renal medulla is in a hypertonic environment related to the renal concentrating mechanism. Renal cells accumulate osmolytes such as betaine to protect cells from the perturbing effect of high concentration of electrolytes. Hypertonicity-induced cell death and the effect of betaine were investigated in Madin Darby canine kidney (MDCK) cells. METHODS: Cell viability was detected by 3-(4,5-dimethylthiazo-2-yl)-2,5-diphenyl tetrazolium bromide assay. DNA fragmentation was determined by FACS analysis, terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) staining and agarose gel electrophoresis. Activities of caspase-1, -3, -8, and -9 were measured. RESULT: When the cells were exposed to 700 mOsm medium for 24 h, 40% of the cells were detached. TUNEL staining showed that about 20% of detached cells were apoptotic, indicating that both necrosis and apoptosis contributed to the hypertonicity-induced cell death in MDCK cells. DNA laddering was demonstrated in hypertonic cells. Caspase-3, -8, and -9 activities of the adherent cells exposed to 700 mOsm for 24 h increased approximately 20-, 3-, and 4-fold the value of isotonic cells, respectively. However, there was no significant change in caspase-1 activity. Addition of 1 mM betaine into the medium protected the cells against the hypertonicity-induced cytotoxicity and apoptosis. Betaine prevented the induction of caspase-3, -8, and -9 activities after hypertonic exposure to about 50%. CONCLUSIONS: The present study demonstrates that (i) apoptosis is involved in the hypertonicity-induced cell death in MDCK cells; (ii) caspase-3, -8, and -9 may contribute to the apoptosis; and (iii) betaine has protective effect on the hypertonicity-induced apoptosis.
Authors: Min Xia; Justine M Abais; Saisudha Koka; Nan Meng; Todd W Gehr; Krishna M Boini; Pin-Lan Li Journal: Kidney Blood Press Res Date: 2016-03-25 Impact factor: 2.687
Authors: Bruna Varela Zanoni; Gabriela Brasil Romão; Rebecca S Andrade; Regina Maria Barretto Cicarelli; Eliane Trovatti; Bruna Galdorfini Chiari-Andrèo; Miguel Iglesias Journal: Toxicol Res (Camb) Date: 2019-02-28 Impact factor: 3.524
Authors: Shona S Craig; Stuart As Craig; Matthew S Ganio; Carl M Maresh; Greg Horrace; Kerry-Ann da Costa; Steven H Zeisel Journal: J Int Soc Sports Nutr Date: 2010-01-22 Impact factor: 5.150