Endothelial-derived complement factor D contributes to endothelial dysfunction in malignant nephrosclerosis via local...

Area of Science:

• Nephrology
• Immunology
• Vascular Biology

Background:

• Malignant nephrosclerosis is a thrombotic microangiopathy linked to complement alternative pathway (AP) activation.
• The precise mechanism of local AP activation in this condition remains unclear.

Purpose of the Study:

• To investigate the role of complement factor D (CFD) secreted by endothelial cells in malignant nephrosclerosis pathogenesis.
• To determine if endothelial-derived CFD triggers local complement activation and vascular dysfunction.

Main Methods:

• Immunofluorescence microscopy and mass spectrometry to detect CFD deposition in human kidney biopsies.
• In vitro studies using human glomerular endothelial cells (CiGEnCs) to assess CFD secretion and function.
• Small interfering RNA (siRNA) mediated knockdown of CFD in CiGEnCs.

Main Results:

• Significant CFD deposition was observed in the kidneys of patients with malignant nephrosclerosis.
• CiGEnCs secreted CFD in vitro, and CFD knockdown reduced local complement activation.
• CFD knockdown attenuated Ang II-induced upregulation of ICAM-1, VCAM-1, VWF, and ET-1.

Conclusions:

• Glomerular endothelial cells are a significant source of local renal CFD.
• Endothelial-derived CFD contributes to local complement system activation.
• Endothelial-derived CFD plays a role in mediating endothelial dysfunction, potentially contributing to malignant nephrosclerosis development.