title: Caveolae-mediated entry of Salmonella typhimurium into senescent nonphagocytotic host cells.
abstract: Elderly individuals have an increased susceptibility to microbial infections because of age-related anatomical, physiological, and environmental factors. However, the mechanism of aging-dependent susceptibility to infection is not fully understood. Here, we found that caveolae-dependent endocytosis is elevated in senescent cells. Thus, we focused on the implications of caveolae-dependent endocytosis using Salmonella typhimurium, which causes a variety of diseases in humans and animals by invading the eukaryotic host cell. Salmonella invasion increased in nonphagocytotic senescent host cells in which caveolin-1 was also increased. When caveolae structures were disrupted by methyl-beta-cyclodextrin or siRNA of caveolin-1 in the senescent cells, Salmonellae invasion was reduced markedly compared to that in nonsenescent cells. In contrast, the over-expression of caveolin-1 led to increased Salmonellae invasion in nonsenescent cells. Moreover, in aged mice, caveolin-1 was found to be highly expressed in Peyer's patch and spleen, which are targets for infection by Salmonellae. These results suggest that high levels of caveolae and caveolin-1 in senescent host cells might be related to the increased susceptibility of elderly individuals to microbial infections.
authors.affiliation: Department of Biochemistry, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Jae Sung
authors.initials: JS
authors.lastname: Lim
authors.forename: Hyon E
authors.initials: HE
authors.lastname: Choy
authors.forename: Sang Chul
authors.initials: SC
authors.lastname: Park
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Han
authors.forename: Ik-Soon
authors.initials: IS
authors.lastname: Jang
authors.forename: Kyung A
authors.initials: KA
authors.lastname: Cho
mesh_terms: D000293:Adolescent; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D021941:Caveolae / Q000502:physiology*; D051242:Caveolin 1 / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D016922:Cellular Senescence; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D012486:Salmonella typhimurium / Q000502:physiology*
chemical_list: D051242:Caveolin 1