Figure 5.

The exosome and KSRP participate in the PMR60-induced decrease in PTH mRNA levels. A-C. Rrp46 knock-down. HEK293 cells were transiently transfected in duplicate with either siRNA for Rrp46 or control CAT siRNA and expression plasmids for hPTH and either PMR60 or an empty vector (pSG5). A. Immunoblot analysis of HEK293 cell extracts 72 h after transfection. Rrp46 levels are presented below the gel as % of Rrp46 in extracts of cells transfected with CAT siRNA. B. Northern blot analysis of RNA extracted from cells transfected in duplicate as above. C. Quantification of the Northern blot data as in B and from 3 independent experiments. D-F. KSRP knock-down. HEK293 cells were transiently transfected in duplicate with either siRNA for KSRP or control CAT siRNA and expression plasmids for hPTH and either PMR60 or an empty vector (pSG5). D. Immunoblot analysis of HEK293 cell extracts 72 h after transfection and quantification of KSRP protein levels, presented below the gel. E. Northern blot analysis of RNA extracted from cells transfected in duplicate as above. F. quantification of Northern blot data from 3 repeat experiments including the one in E. Results in C and F are presented as mean ± SE of mRNA levels compared to cells transfected with CAT siRNA and pSG5 plasmid (*, p < 0.05) or compared to CAT siRNA and PMR60 transfected cells (**, p < 0.05).