Hyperplasia of parathyroid cells induced by high phosphate via local cyciooxygenase 2 pathway in uremic patients / 中华肾脏病杂志

ABSTRACT

Objective To explore whether the stimulation effect of high phosphate on hyperplasia of human parathyroid cells and hyperparathyroidism through local cyclooxygenase 2 (COX2) up-regulation pathway. Methods Parathyroid glands were collected from 19 uremic patients undergoing parathyroidectomy.Expressions of COX1,COX2 and proliferative cell nuclear antigen (PCNA) of the glands were detected by immunohistochemistry.Primary parathyroid cells were cultured and treated with high or normal phosphate for 48 hours.Then expressions of COX2 and PCNA were detected by Western blotting and real-time PCR. Results Among 62 glands from above 19 patients,43 glands were nodular hyperplasia and 19 diffuse hyperplasia.Both high expressions of COX2 and PCNA were found in these blands.Expression of COX2 was found in both oxyphil and chief cells and was more in the diffuse hyperplasia glands than that in the nodular hyperplasia (P＜0.05).80.60％ and 85.20％ of COX2 positive cells in diffuse hyperplasia glands and nodular hyperplasia also expressed PCNA. High phosphate could stimulate iPTH secretion in vitro (P＜0.05).Expressions of COX2 and PCNA were higher in high phosphate group.(P＜0.05). Conclusion High phosphate may stimulate the hyperplasia of parathyroid cells by up-regulating the local COX2 expression.