Altered function, localization and phosphorylation of gap junctions in rat liver epithelial, IAR 20, cells after treatment with PCBs or TCDD.
ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 1997;
3:257-266. [PMID:
21781786 DOI:
10.1016/s1382-6689(97)00021-5]
[Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/1997] [Revised: 05/14/1997] [Accepted: 05/20/1997] [Indexed: 05/31/2023]
Abstract
Three different PCB-congeners 3,4,5,3',4'-pentachlorobiphenyl (IUPAC no. 126), 2,4,5,2',4',5'-hexachlorobiphenyl (IUPAC no. 153) and 2,4,5,3',4'-pentachlorobiphenyl (IUPAC no. 118) were investigated for possible structure-activity relationships in altering gap junction intercellular proteins. All tested PCB-congeners and TCDD decreased the gap junctional intercellular communication in IAR 20 cells, but at different treatment periods, suggesting different modes of action. The presence of the Cx43-P(2) band, a phosphorylated isoform of Cx43, was associated with a functional communication. A reduced Cx43 mRNA level was noted after 48 h of exposure with PCB 126, PCB 118 and TCDD. In summary, the non dioxin-like PCB 153 can decrease gap junctional intercellular communication rapidly by reducing the phosphorylated isoform of Cx43, whereas the dioxin-like PCB 126 and TCDD reduce the communication slowly by decreasing the mRNA level of Cx43, resulting in a reduced Cx43 protein level (which includes the P(2)-band). The mixed inducing PCB-congener, PCB 118, can act both as the dioxin-like and the non dioxin-like PCBs in gap junction regulation.
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