Cytokine production by cells adherent to regenerative membranes

Abstract

Since cytokines play a critical role in tissue regeneration, we have assayed cytokine production by cells from tissue adherent to regenerative membranes. Cells were recovered from Gore-tex membranes in guided tissue regeneration (GTR) procedures to regenerate that attachment apparatus around teeth and from Gore-tex augmentation membranes (GTAM) used for guided gone regeneration (GBR) procedures in edentulous ridge augmentation with or without implant placement. Cells were screened for mineralized nodule formation in vitro to mRNA analysis to demonstrate that they could form mineralized tissue. Production in interleukin-1 alpha (IL-1 alpha) interleukin-1 beta (IL-1 beta), interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) was evaluated by reverse transcribed-polymerase chain reaction (RT-PCR) of mRNA from rescued regenerative cells, human gingival fibroblasts and periodontal ligament (PDL) cells. Both the gingival fibroblast and PDL cells isolates produced all 4 cytokines. However, the cell isolates from the regenerative membranes had various profiles of cytokine expression. Most GTR cell isolates were positive for all 4 cytokines. IL-1 beta was produced by all 6 GTR cell isolates but was not detected at the same number of cycles of RT-PCR amplification in any of the 6 GBR cell isolates. IL-1 beta transcripts were also not observed in cells derived from a direct biopsy of GBR tissue. Cells were recovered from unexposed GBR membranes did not produce detectable amounts of IFN-gamma, whereas cells recovered from exposed GBR and all GTR membranes produced IFN-gamma. These findings indicate that cells from regenerative tissues express different cytokines and that exposure to the tissue to the oral cavity during healing may modulate this expression.