PURPOSE: Following the recent demonstration of increased mitochondrial DNA mutations in lymphocytes of POAG patients, the authors sought to characterize mitochondrial function in a separate cohort of POAG. METHODS: Using similar methodology to that previous applied to Leber's hereditary optic neuropathy (LHON) patients, maximal adenosine triphosphate (ATP) synthesis and cellular respiration rates, as well as cell growth rates in glucose and galactose media, were assessed in transformed lymphocytes from POAG patients (n = 15) and a group of age- and sex-matched controls (n = 15). RESULTS: POAG lymphoblasts had significantly lower rates of complex-I-driven ATP synthesis, with preserved complex-II-driven ATP synthesis. Complex-I driven maximal respiration was also significantly decreased in patient cells. Growth in galactose media, where cells are forced to rely on mitochondrial ATP production, revealed no significant differences between the control and POAG cohort. CONCLUSIONS: POAG lymphoblasts in the study cohort exhibited a defect in complex-I of the oxidative phosphorylation pathway, leading to decreased rates of respiration and ATP production. Studies in LHON and other diseases have established that lymphocyte oxidative phosphorylation measurement is a reliable indicator of systemic dysfunction of this pathway. While these defects did not impact lymphoblast growth when the cells were forced to rely on oxidative ATP supply, the authors suggest that in the presence of a multitude of cellular stressors as seen in the early stages of POAG, these defects may lead to a bioenergetic crisis in retinal ganglion cells and an increased susceptibility to cell death.
PURPOSE: Following the recent demonstration of increased mitochondrial DNA mutations in lymphocytes of POAG patients, the authors sought to characterize mitochondrial function in a separate cohort of POAG. METHODS: Using similar methodology to that previous applied to Leber's hereditary optic neuropathy (LHON) patients, maximal adenosine triphosphate (ATP) synthesis and cellular respiration rates, as well as cell growth rates in glucose and galactose media, were assessed in transformed lymphocytes from POAG patients (n = 15) and a group of age- and sex-matched controls (n = 15). RESULTS: POAG lymphoblasts had significantly lower rates of complex-I-driven ATP synthesis, with preserved complex-II-driven ATP synthesis. Complex-I driven maximal respiration was also significantly decreased in patient cells. Growth in galactose media, where cells are forced to rely on mitochondrial ATP production, revealed no significant differences between the control and POAG cohort. CONCLUSIONS: POAG lymphoblasts in the study cohort exhibited a defect in complex-I of the oxidative phosphorylation pathway, leading to decreased rates of respiration and ATP production. Studies in LHON and other diseases have established that lymphocyte oxidative phosphorylation measurement is a reliable indicator of systemic dysfunction of this pathway. While these defects did not impact lymphoblast growth when the cells were forced to rely on oxidative ATP supply, the authors suggest that in the presence of a multitude of cellular stressors as seen in the early stages of POAG, these defects may lead to a bioenergetic crisis in retinal ganglion cells and an increased susceptibility to cell death.
Authors: Harini V Gudiseva; Maxwell Pistilli; Rebecca Salowe; Larry N Singh; David W Collins; Brian Cole; Jie He; Sayaka Merriam; Naira Khachataryan; Jeffrey Henderer; Victoria Addis; Qi N Cui; Prithvi S Sankar; Eydie Miller-Ellis; Venkata R M Chavali; Gui-Shuang Ying; Douglas Wallace; Joan M O'Brien Journal: Exp Eye Res Date: 2019-01-15 Impact factor: 3.467
Authors: Fiona C Mansergh; Naomi Chadderton; Paul F Kenna; Oliviero L Gobbo; G Jane Farrar Journal: Eur J Hum Genet Date: 2014-02-26 Impact factor: 4.246
Authors: Jessica N Cooke Bailey; Brian L Yaspan; Louis R Pasquale; Michael A Hauser; Jae H Kang; Stephanie J Loomis; Murray Brilliant; Donald L Budenz; William G Christen; John Fingert; Douglas Gaasterland; Terry Gaasterland; Peter Kraft; Richard K Lee; Paul R Lichter; Yutao Liu; Catherine A McCarty; Sayoko E Moroi; Julia E Richards; Tony Realini; Joel S Schuman; William K Scott; Kuldev Singh; Arthur J Sit; Douglas Vollrath; Gadi Wollstein; Donald J Zack; Kang Zhang; Margaret A Pericak-Vance; R Rand Allingham; Robert N Weinreb; Jonathan L Haines; Janey L Wiggs Journal: Hum Genet Date: 2014-07-19 Impact factor: 4.132