Duodenal biopsies are considered a suitable source of enterocytes for studies of dietary iron absorption. However, the expression level of molecules involved in iron absorption may vary along the length of duodenum. We aimed to determine whether the expression of molecules involved in the absorption of heme and non-heme iron differs depending on the location in the duodenum. Analysis was performed with samples of duodenal biopsies from 10 individuals with normal iron metabolism. Samples were collected at the following locations: (a) immediately post-bulbar, (b) 1-2 cm below the papilla of Vater and (c) in the distal duodenum. The gene expression was analyzed at the mRNA and protein level using real-time PCR and Western blot analysis. At the mRNA level, significantly different expression of HCP1, DMT1, ferroportin and Zip8 was found at individual positions of duodenum. Position-dependent expression of other molecules, especially of FLVCR1, HMOX1 and HMOX2 was also detected but with no statistical significances. At the protein level, we observed statistically significantly decreasing expression of transporters HCP1, FLVCR1, DMT1, ferroportin, Zip14 and Zip8 with advancing positions of duodenum. Our results are consistent with a gradient of diminishing iron absorption along the duodenum for both heme and non-heme iron.

• Klíčová slova
• heme iron absorption, iron transport, iron uptake in duodenum, non-heme iron absorption,
• MeSH
• duodenum * metabolismus   MeSH
• hem metabolismus   MeSH
• iontový transport MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• železo * metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hem MeSH
• messenger RNA MeSH
• železo * MeSH

Persistent organochlorine pollutants (POPs) gradually accumulate in the human organism due to their presence in the environment. Some studies have described a correlation between the level of POPs in the human body and the incidence of diabetes, but we know little about the direct effect of POPs on pancreatic beta-cells. We exposed pancreatic beta-cells INS1E to non-lethal concentrations of p,p'-DDT (1,1'-(2,2,2-Trichloroethane-1,1-diyl)bis(4-chlorobenzene)) and p,p'-DDE (1,1'-(2,2-dichloroethene-1,1-diyl)bis(4-chlorobenzene)) for 1 month, and assessed changes in protein expression and the intracellular insulin level. 2-D electrophoresis revealed 6 proteins with changed expression in cells exposed to p,p'-DDT or p,p'-DDE. One of the detected proteins - vitamin D-binding protein (VDBP) - was upregulated in both cells exposed to p,p'-DDT, and cells exposed to p,p'-DDE. Both exposures to pollutants reduced the intracellular level of insulin mRNA, proinsulin, and insulin monomer; p,p'-DDT also slightly reduced the level of hexameric insulin. Overexpression of VDBP caused by the stable transfection of beta-cells with the gene for VDBP decreased both the proinsulin and hexameric insulin level in beta-cells similarly to the reduction detected in cells exposed to p,p'-DDT. Our data suggest that in the cells exposed to p,p'-DDT and p,p'-DDE, the increased VDBP protein level decreased the proinsulin expression in an unknown mechanism.

• MeSH
• beta-buňky účinky léků   metabolismus   MeSH
• buněčné linie MeSH
• DDT toxicita   MeSH
• dichlordifenyldichlorethylen toxicita   MeSH
• inzulin metabolismus   MeSH
• krysa rodu Rattus MeSH
• látky znečišťující životní prostředí toxicita   MeSH
• protein vázající vitamin D metabolismus   MeSH
• testy subchronické toxicity MeSH
• upregulace účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DDT MeSH
• dichlordifenyldichlorethylen MeSH
• inzulin MeSH
• látky znečišťující životní prostředí MeSH
• protein vázající vitamin D MeSH