Copyright ©The Author(s) 2018.
World J Gastroenterol. Nov 14, 2018; 24(42): 4721-4727
Published online Nov 14, 2018. doi: 10.3748/wjg.v24.i42.4721
Table 2 Structural, functional and biochemical abnormalities of aging gastric mucosa
Partial atrophy of gastric glands and their replacement with connective tissue
Degenerative changes in parietal and chief cells
↓ Sensory innervation and abolished hyperemic response to mild and moderate irritants
↓ Bicarbonate and prostaglandin generation and secretion
↓ Mucosal blood flow (by > 60%) and profound hypoxia of all mucosal cells
↑ Expression and transcriptional activity of early growth response-1→ ↑ PTEN and ↓ survivin (anti-apoptosis protein) → ↑ apoptosis
Other abnormalities include:
↓ Telomerase activity, cellular senescence, increased lipid peroxidation, impaired hypoxia sensor in endothelial (and epithelial?) cells
↑ Reactive oxygen species
Downregulated or mutated Klotho protein and dysregulated mitochondrial-nuclear communication
↓ Importin-α expression in endothelial cells of gastric mucosa → ↓activation and ↓expression of vascular endothelial growth factor (VEGF), which is a pro-angiogenic factor and protects gastric endothelial cells; imbalance between VEGF and endostatin
↓ Expression of nerve growth factor in gastric mucosal endothelial cells → reduced endothelial cell viability, impaired angiogenesis and gastric ulcer healing