Vitamin E and caloric restriction promote hepatic homeostasis through expression of connexin 26, N-cad, E-cad and cholesterol metabolism genes.
Connexins (Cx) and cadherins are responsible for cell homeostasis. The Cx activity is directly related to cholesterol. The present work investigates whether vitamin E, with or without caloric restriction (CR), alters the mRNA expression of Cx26, Cx32, Cx43, N-cadherins (N-cads), E-cadherins (E-cads) and alpha-smooth muscle actin (α-SMA), and evaluates their relation to cholesterol metabolism in rat liver. Animals were divided into different groups: control with ad libitum diet (C), control+vitamin E (CV), aloric restriction with intake to 60% of group C (CR), and the intake of group CR+vitamin E (RV). There were increases of manganese superoxide dismutase (Mn-SOD) and glutathione S-transferase mu 1, indicating antioxidant effects of CR and vitamin E. An increase of nitric oxide in the CR group was in agreement with the Mn-SOD data. Supplementation with vitamin E, with or without CR, upregulated the expression of Cx26 mRNA and increased low-density lipoprotein cholesterol (LDL-c) in the CV group. Reductions of Cx32 and Cx43 were associated with lower LDL-c. Increases in Hmgcr and low-density lipoprotein receptor (LDLr) in the CV and RV groups could be explained by the effect of vitamin E. A reduction of LDLr in the CR group was due to the reduced dietary intake. Increases in cadherins in the CV, CR and RV groups were indicative of tissue maintenance, which was also supported by increases of α-SMA in groups CV and RV. Finally, vitamin E, with or without CR, increased Cx26, probably modulated by expression of the Hmgcr and LDLr genes. This suggests important relationship of Cxs and cholesterol metabolism genes.
Graduate Program in Biomedical Sciences, Centro Universitário Hermínio Ometto, UNIARARAS, Araras, SP 13607339, Brazil.
Leonardo Vinícius
LV
Santolim
Graduate Program in Biomedical Sciences, Centro Universitário Hermínio Ometto, UNIARARAS, Araras, SP 13607339, Brazil.
Maria Esméria Corezola do
MECD
Amaral
School of Biomedicine, Centro Universitário Hermínio Ometto, UNIARARAS, Araras, SP 13607339, Brazil.
José Luís
JL
Fachi
Graduate Program in Biomedical Sciences, Centro Universitário Hermínio Ometto, UNIARARAS, Araras, SP 13607339, Brazil.
Maíra Felonato
MF
Mendes
Graduate Program in Biomedical Sciences, Centro Universitário Hermínio Ometto, UNIARARAS, Araras, SP 13607339, Brazil. Electronic address: caol@uniararas.br.
Camila Andréa de
CA
Oliveira
D000818:Animals; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D031204:Caloric Restriction; D008078:Cholesterol, LDL / Q000097:blood; D000072259:Connexin 26; D018031:Connexin 43 / Q000235:genetics / Q000378:metabolism; D017630:Connexins / Q000235:genetics / Q000378:metabolism*; D004032:Diet; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D006706:Homeostasis; D050356:Lipid Metabolism / Q000235:genetics; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D014810:Vitamin E / Q000494:pharmacology*; D000097002:Gap Junction beta-1 Protein
D015820:Cadherins; D008078:Cholesterol, LDL; D000072259:Connexin 26; D018031:Connexin 43; D017630:Connexins; D005982:Glutathione Transferase; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D013482:Superoxide Dismutase; D014810:Vitamin E; D000097002:Gap Junction beta-1 Protein; C000610228:CDH1 protein, rat; C580592:Gja1 protein, rat; C000607044:Gjb2 protein, rat; C570099:N-cadherin, rat
Cadherins; Caloric restriction; Connexins; Lipids; Oxidative stress; Vitamin E