Enhancement effect of properdin (P) in complement alternative pathway (AP) activation on proximal tubular epithelial cells (PTECs), PTECs were incubated with P-depleted serum (PDS; 5% or 25%) for 3 h. Preincubation with P (5 μg/mL) for 3 h before the addition of PDS increased the depositions of P, C3 and MAC (b, d) compared with the addition of intact PDS only (a, c). Depositions of P were slightly detected with the addition of 25% PDS, but not 5% PDS. Quantitative analysis was performed, and preincubation with P before the addition of PDS significantly increased the depositions of C3 (e, g) (5% PDS, **p < 0.001; 25% PDS, *p = 0.0079) and relatively increased the depositions of MAC (p = 0.0556) (f, h) compared with the addition of intact PDS only. Results are expressed as means ± standard errors of values from five representative lesions. Original magnification: ×100. Arrow: depositions of P, fH, C3 or MAC.
Nagamachi et al. BMC Nephrology 2014 15:82 doi:10.1186/1471-2369-15-82