Effect of aging on gastric mucosal defense mechanisms: ROS, apoptosis, angiogenesis, and sensory neurons.
Aging changes in the stomach lead to a decreased capacity for tissue repair in response to gastric acid. The aim of this study was to determine the mechanism associated with the increased susceptibility to injury of aging mucosa including reactive oxygen species (5), apoptosis, angiogenesis, and sensory neuron activity. Fischer 344 rats at four different ages (6, 31, 74 wk, and 2 yr of age) were studied. The connective tissue indicators [salt-soluble collagen and sulfated glycosaminoglycan (sGAG)], lipid hydroperoxide (LPO), myeloperoxidase (MPO), and hexosamine were assessed. We also evaluated the expression of early growth response-1 (Egr-1), phosphatase and tension homologue deleted on chromosome 10 (PTEN), caspase-9 (index of apoptosis), VEGF (index of angiogenesis), calcitonin gene-related peptide (CGRP, index of sensory neurons), and neuronal nitric oxide synthase (nNOS). The histological connective tissue area in the lower part of rat gastric mucosa increased with aging, with increase of salt-soluble collagen and sGAG. LPO and MPO in old rats were significantly greater than in the young rats, whereas hexosamine was significantly reduced. The old gastric mucosa had increased expression of Egr-1, PTEN, and caspase-9, whereas the VEGF, CGRP, and nNOS expression were significantly reduced. These results indicate that the lower part of rat gastric mucosa was found to be replaced by connective tissue with accumulation of oxidative products with aging. In addition, impairment of apoptosis, angiogenesis, and sensory neuron activity via the activation of Egr-1 and PTEN might increase the susceptibility of gastric mucosa to injury during aging.
Kang
Jung Mook
JM
Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
Kim
Nayoung
N
Kim
Joo-Hyon
JH
Oh
Euichaul
E
Lee
Bong-Yong
BY
Lee
Byoung Hwan
BH
Shin
Cheol Min
CM
Park
Ji Hyun
JH
Lee
Mi Kyoung
MK
Nam
Ryoung Hee
RH
Lee
Hee Eun
HE
Lee
Hye Seung
HS
Kim
Joo Sung
JS
Jung
Hyun Chae
HC
Song
In Sung
IS
D000375:Aging / Q000502:physiology*; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D015153:Blotting, Western; D003238:Connective Tissue / Q000378:metabolism; D005753:Gastric Mucosa / Q000502:physiology*; D008297:Male; D018919:Neovascularization, Physiologic / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D011984:Sensory Receptor Cells / Q000502:physiology*; D018709:Statistics, Nonparametric
D017382:Reactive Oxygen Species