Fig. 1

Morphology of cortical fibroblasts isolated from cats with normal kidney function (FCF) and CKD (CKD-FCF). Representative photomicrographs of FCF. a, b: CKD-FCF 72 h post isolation. In the presence of FBS, randomly orientated fusiform cells proliferate and begin to dominate the culture c: CKD-FCF 7 days post isolation. Prior to the first passage, although the predominating cell type appears fibroblastic, there are still isolated pockets of epithelial cells. d: CKD-FCF, passage 1: Relatively homogenous monolayers of cells in parallel arrays are present in cultures derived from diseased kidneys e: FCF, passage 1: In cultures derived from cats with normal kidney function, cultures at passage 1 are still heterogenous and include pockets of epithelial cells. These cultures are homogenous in nature by passage 2. f: CKD-FCF, passage 5: After 4–9 passages, cells developed replicative senescence and underwent a change in morphology. Images were collected using a DMIRB inverted microscope with samples illuminated using an EBQ100 light source (Leica Microsystems, Milton Keynes, UK) and an AxioCam ICm1 monochrome camera controlled through Axiovision software version 4.8.2 (Carl Zeiss Ltd., Cambridge, UK)