PRNP and chronic kidney disease: We injected normal hMSCs, CKD-hMSCs, TUDCA-treated CKD-hMSCs, TUDCA-treated CKD-hMSCs with si-PRNP, and TUDCA-treated CKD-hMSCs with scramble siRNA intravenously via the tail on day 0, 5, and 10.