TY - JOUR
T1 - Aging Gastropathy-Novel Mechanisms
T2 - Hypoxia, Up-regulation of Multifunctional Phosphatase PTEN, and Proapoptotic Factors
AU - Tarnawski, Andrzej
AU - Pai, Rama
AU - Deng, Xiaoming
AU - Ahluwalia, Amrita
AU - Khomenko, Tetyana
AU - Tanigawa, Tetsuya
AU - Akahoshi, Tomohiko
AU - Sandor, Zsuzsanna
AU - Szabo, Sandor
N1 - Funding Information:
Supported by the VA Merit Reviews (to A.S.T. and S.S.) and the NIA Pilot Study Program (to A.S.T).
PY - 2007/12
Y1 - 2007/12
N2 - Background & Aims: Aging gastric mucosa has impaired mucosal defense and increased susceptibility to injury. Our aims were to determine the mechanisms responsible for above abnormalities. Methods: We used Fisher F-344 rats, 3 and 24 months of age. We measured gastric mucosal blood flow; visualized mucosal hypoxia; examined expression of early growth response-1 transcription factor and phosphatase and tensin homologue deleted on chromosome 10 (PTEN); assessed apoptosis; and determined expression of caspase-3, caspase-9, and survivin. We also examined susceptibility of gastric mucosa of young and aging rats to ethanol injury and whether down-regulation of PTEN affects susceptibility of aging gastric mucosa to injury. To determine human relevance, we examined expression of PTEN and survivin in human gastric specimens of young and aging individuals. Results: Gastric mucosa of aging (vs young) rats has a 60% reduction in mucosal blood flow; prominent hypoxia; and increased early growth response-1 transcription factor and PTEN messenger RNAs, and proteins. It also has increased expression of proapoptotic proteins caspase-3 and capase-9, reduced survivin, and a 6-fold increased apoptosis vs mucosa of young rats. Ethanol-induced gastric mucosal injury in aging (vs young) rats was significantly increased. The down-regulation of PTEN in gastric mucosa of aging rats completely reversed its increased susceptibility to ethanol injury. In aging human gastric mucosa, PTEN expression was significantly increased, whereas survivin was significantly reduced. Conclusions: (1) Gastric mucosa of aging rats has significantly reduced blood flow, tissue hypoxia, activation of Egr-1, PTEN; increased caspases; and reduced survivin. (2) These changes increase susceptibility of aging gastric mucosa to injury.
AB - Background & Aims: Aging gastric mucosa has impaired mucosal defense and increased susceptibility to injury. Our aims were to determine the mechanisms responsible for above abnormalities. Methods: We used Fisher F-344 rats, 3 and 24 months of age. We measured gastric mucosal blood flow; visualized mucosal hypoxia; examined expression of early growth response-1 transcription factor and phosphatase and tensin homologue deleted on chromosome 10 (PTEN); assessed apoptosis; and determined expression of caspase-3, caspase-9, and survivin. We also examined susceptibility of gastric mucosa of young and aging rats to ethanol injury and whether down-regulation of PTEN affects susceptibility of aging gastric mucosa to injury. To determine human relevance, we examined expression of PTEN and survivin in human gastric specimens of young and aging individuals. Results: Gastric mucosa of aging (vs young) rats has a 60% reduction in mucosal blood flow; prominent hypoxia; and increased early growth response-1 transcription factor and PTEN messenger RNAs, and proteins. It also has increased expression of proapoptotic proteins caspase-3 and capase-9, reduced survivin, and a 6-fold increased apoptosis vs mucosa of young rats. Ethanol-induced gastric mucosal injury in aging (vs young) rats was significantly increased. The down-regulation of PTEN in gastric mucosa of aging rats completely reversed its increased susceptibility to ethanol injury. In aging human gastric mucosa, PTEN expression was significantly increased, whereas survivin was significantly reduced. Conclusions: (1) Gastric mucosa of aging rats has significantly reduced blood flow, tissue hypoxia, activation of Egr-1, PTEN; increased caspases; and reduced survivin. (2) These changes increase susceptibility of aging gastric mucosa to injury.
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U2 - 10.1053/j.gastro.2007.08.037
DO - 10.1053/j.gastro.2007.08.037
M3 - Article
C2 - 18054565
AN - SCOPUS:36549079651
SN - 0016-5085
VL - 133
SP - 1938-1947.e1
JO - Gastroenterology
JF - Gastroenterology
IS - 6
ER -