TY - JOUR
T1 - Increase in Paracellular Leakage of Amino Acids Mediated by Aging-Induced Reduction of Claudin-4 Expression
AU - Okamoto, Ema
AU - Matsuda, Shunsuke
AU - Yoshino, Yuta
AU - Morikawa, Yoshifumi
AU - Suenami, Koichi
AU - Tabuchi, Yoshiaki
AU - Matsunaga, Toshiyuki
AU - Hayashi, Hisayoshi
AU - Ikari, Akira
N1 - Publisher Copyright:
© 2023 American Society for Nutrition
PY - 2023/12
Y1 - 2023/12
N2 - Background: Claudins (CLDNs), major components of tight junctions, control paracellular permeabilities of mineral ions and wastes. The absorption of nutrients including glucose and amino acids (AAs) is regulated by intestinal epithelial cells. However, the role of CLDNs is not fully understood. Objectives: The purpose of this study was to clarify the effect of AA deprivation on the expression of AA transporters and CLDNs, as well as the role of CLDNs in the regulation of paracellular AA fluxes. Methods: The messenger RNA and protein expression of various CLDNs were examined by real-time quantitative polymerase chain reaction and Western blot analyses, respectively. The AA selectivity of CLDNs was estimated using liquid chromatography-tandem mass spectrometry (LC-MS) analysis. Results: The expression levels of some AA transporters, CLDN4, and CLDN15 were increased by AA deprivation in normal mouse colon-derived MCE301 cells. The expression of AA transporters and CLDN15 in the mouse colon was positively correlated with aging but the expression of CLDN4 was not. The AA deprivation-induced elevation of CLDN4 expression was inhibited by MHY1485, a mammalian target of rapamycin (mTOR) activator. Furthermore, CLDN4 expression was increased by rapamycin, an mTOR inhibitor. mTOR may be involved in the transcriptional activation of CLDN4. The fluxes of AAs from the basal to apical compartments were decreased and increased by CLDN4 overexpression and silencing, respectively. LC-MS analysis showed that the fluxes of all AAs, especially Lys, His, and Arg, were enhanced by CLDN4 silencing. Conclusions: CLDN4 is suggested to form a paracellular barrier to AAs, especially alkaline AAs, which is attenuated with aging.
AB - Background: Claudins (CLDNs), major components of tight junctions, control paracellular permeabilities of mineral ions and wastes. The absorption of nutrients including glucose and amino acids (AAs) is regulated by intestinal epithelial cells. However, the role of CLDNs is not fully understood. Objectives: The purpose of this study was to clarify the effect of AA deprivation on the expression of AA transporters and CLDNs, as well as the role of CLDNs in the regulation of paracellular AA fluxes. Methods: The messenger RNA and protein expression of various CLDNs were examined by real-time quantitative polymerase chain reaction and Western blot analyses, respectively. The AA selectivity of CLDNs was estimated using liquid chromatography-tandem mass spectrometry (LC-MS) analysis. Results: The expression levels of some AA transporters, CLDN4, and CLDN15 were increased by AA deprivation in normal mouse colon-derived MCE301 cells. The expression of AA transporters and CLDN15 in the mouse colon was positively correlated with aging but the expression of CLDN4 was not. The AA deprivation-induced elevation of CLDN4 expression was inhibited by MHY1485, a mammalian target of rapamycin (mTOR) activator. Furthermore, CLDN4 expression was increased by rapamycin, an mTOR inhibitor. mTOR may be involved in the transcriptional activation of CLDN4. The fluxes of AAs from the basal to apical compartments were decreased and increased by CLDN4 overexpression and silencing, respectively. LC-MS analysis showed that the fluxes of all AAs, especially Lys, His, and Arg, were enhanced by CLDN4 silencing. Conclusions: CLDN4 is suggested to form a paracellular barrier to AAs, especially alkaline AAs, which is attenuated with aging.
KW - aging
KW - amino acid transporter
KW - claudin-4
KW - colon
KW - mTOR
KW - paracellular barrier
UR - http://www.scopus.com/inward/record.url?scp=85174504893&partnerID=8YFLogxK
U2 - 10.1016/j.tjnut.2023.09.026
DO - 10.1016/j.tjnut.2023.09.026
M3 - 学術論文
C2 - 37806357
AN - SCOPUS:85174504893
SN - 0022-3166
VL - 153
SP - 3360
EP - 3372
JO - Journal of Nutrition
JF - Journal of Nutrition
IS - 12
ER -