Complement injury and CRP stress alter inflammatory cytokine secretion in AMD iPSC derived choroidal endothelial cells.

Abstract

Purpose : Inflammation, complement pathway activation and immune cell infiltration are involved in AMD pathogenesis. However, the specific cytokines regulating immune cell recruitment and activation in the choroid of AMD patients remains to be determined. We performed cytokine profiling on iPSC derived choroidal endothelial cells (CECs) from AMD donors injured with either monomeric C-reactive protein (mCRP) or the membrane attack complex (MAC) of complement to determine, which cytokines released from injured CECs could act as signals to recruit immune cells during AMD progression.

Methods : iPSC derived CECs were generated from 2 AMD donors. iPSC derived CECs were treated with monomeric CRP; C9-deficient serum; or complement-intact normal human serum (NHS) to induce complement activation and MAC deposition. Culture supernatants were collected after 24 hours, and secreted cytokines were assayed with a human inflammation array from RayBiotech.

Results : Changes in several cytokines were observed in iPSC derived CECs injured with either mCRP or MAC. For example, CCL5 was upregulated in response to complement injury and in contrast IL-6 was downregulated (Fig 1).

Conclusions : Increased complement and CRP deposition in early AMD contributes to choroidal cell injury. In vitro, complement and mCRP stressed endothelial cells produce inflammatory cytokines which are likely involved in immune cell recruitment and activation contributing to the inflammatory stress of the choroid early in AMD progression.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.