Establishment and functional characterization of human peritoneal fibroblasts in culture: regulation of interleukin-6 production by proinflammatory cytokines.

The functional and morphologic integrity of the peritoneal membrane is of major importance for the successful treatment of patients with chronic peritoneal dialysis. This study aimed at the establishment and functional characterization of human peritoneal fibroblasts (HPFB) in cell culture. HPFB were isolated from human omentum by enzymatic digestion and cultured. Confluent HPFB could be identified as spindle-shaped cells, growing in parallel arrays and whorls which stained positive for vimentin and negative for factor VIII, cytokeratin 18, and desmin. Maximum cell growth was observed after 24 h in medium supplemented with 10% fetal calf serum. HPFB could be growth arrested and maintained in fetal calf serum-depleted medium (0.1%) for > 48 h without loss of cell viability as evaluated by intracellular ATP determination. Stimulation of resting HPFB for 0.5 to 48 h with increasing doses of interleukin (IL)-1 beta and/or tumor necrosis factor-alpha (1 to 10,000 pg/mL) resulted in a dose- and time-dependent induction of IL-6 messenger RNA and an increase in immunoreactive IL-6 protein secreted into HPFB supernatants, which was significant with IL-1 beta or tumor necrosis factor-alpha doses as low as 1 pg/mL. HPFB IL-6 production could be inhibited by both actinomycin D or cycloheximide, which suggests that the induction of IL-6 occurs both on a transcriptional and a post-transcriptional level. In summary, this cell culture model is expected to facilitate further investigation of the potential role of the HPFB in the peritoneal cytokine network of patients treated with chronic peritoneal dialysis.