Soluble CD40 ligand directly alters glomerular permeability and may act as a circulating permeability factor in FSGS

PLoS One. 2017 Nov 20;12(11):e0188045. doi: 10.1371/journal.pone.0188045. eCollection 2017.

Abstract

CD40/CD40 ligand (CD40L) dyad, a co-stimulatory bi-molecular complex involved in the adaptive immune response, has also potent pro-inflammatory actions in haematopoietic and non-haematopoietic cells. We describe here a novel role for soluble CD40L (sCD40L) as modifier of glomerular permselectivity directly acting on glomerular epithelial cells (GECs). We found that stimulation of CD40, constitutively expressed on GEC cell membrane, by the sCD40L rapidly induced redistribution and loss of nephrin in GECs, and increased albumin permeability in isolated rat glomeruli. Pre-treatment with inhibitors of CD40-CD40L interaction completely prevented these effects. Furthermore, in vivo injection of sCD40L induced a significant reduction of nephrin and podocin expression in mouse glomeruli, although no significant increase of urine protein/creatinine ratio was observed after in vivo injection. The same effects were induced by plasma factors partially purified from post-transplant plasma exchange eluates of patients with focal segmental glomerulosclerosis (FSGS), and were blocked by CD40-CD40L inhibitors. Moreover, 17 and 34 kDa sCD40L isoforms were detected in the same plasmapheresis eluates by Western blotting. Finally, the levels of sCD40Lwere significantly increased in serum of children both with steroid-sensitive and steroid-resistant nephrotic syndrome (NS), and in adult patients with biopsy-proven FSGS, compared to healthy subjects, but neither in children with congenital NS nor in patients with membranous nephropathy. Our results demonstrate that sCD40L directly modifies nephrin and podocin distribution in GECs. Moreover, they suggest that sCD40L contained in plasmapheresis eluates from FSGS patients with post-transplant recurrence may contribute, presumably cooperating with other mediators, to FSGS pathogenesis by modulating glomerular permeability.

MeSH terms

  • Adolescent
  • Adrenal Cortex Hormones / therapeutic use
  • Adult
  • Albumins / genetics
  • Albumins / metabolism
  • Animals
  • CD40 Antigens / genetics*
  • CD40 Antigens / metabolism
  • CD40 Ligand / genetics*
  • CD40 Ligand / metabolism
  • CD40 Ligand / pharmacology
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Cell Membrane / pathology
  • Cell Membrane Permeability
  • Child
  • Child, Preschool
  • Cytotoxins / therapeutic use
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism
  • Epithelial Cells / pathology
  • Female
  • Gene Expression Regulation
  • Glomerulonephritis, Membranous / drug therapy
  • Glomerulonephritis, Membranous / genetics
  • Glomerulonephritis, Membranous / metabolism*
  • Glomerulonephritis, Membranous / pathology
  • Glomerulosclerosis, Focal Segmental / genetics
  • Glomerulosclerosis, Focal Segmental / metabolism*
  • Glomerulosclerosis, Focal Segmental / pathology
  • Glomerulosclerosis, Focal Segmental / surgery
  • Hemodialysis Solutions / chemistry
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Kidney Glomerulus / drug effects
  • Kidney Glomerulus / metabolism*
  • Kidney Glomerulus / pathology
  • Kidney Transplantation
  • Male
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Mice
  • Nephrotic Syndrome / drug therapy
  • Nephrotic Syndrome / genetics
  • Nephrotic Syndrome / metabolism*
  • Nephrotic Syndrome / pathology
  • Plasma Exchange
  • Plasmapheresis
  • Rats

Substances

  • Adrenal Cortex Hormones
  • Albumins
  • CD40 Antigens
  • Cytotoxins
  • Hemodialysis Solutions
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • NPHS2 protein
  • nephrin
  • CD40 Ligand

Grants and funding

This study was supported by “Cinque per mille of IRPEF – Finanziamento della ricerca sanitaria”, Italian Ministry of Health – “Ricerca Corrente- Contributo per la ricerca intramuraria” to Istituto Giannina Gaslini, Renal Child Foundation, and Fondazione La Nuova Speranza (“Progetto integrato per la definizione dei meccanismi implicati nella glomerulosclerosi focale”) to G.M.G., by Fondazione la Nuova Speranza ONLUS – Lotta alla Glomerulosclerosi Focale” to C.Z and M.C., by Italian Ministry of Health – Local project ex-60% and Progetto di Ricerca Sanitaria Finalizzata–Regione Piemonte to E.L., and by Italian Ministry of Health - PRIN Project (“Regione Piemonte, Piattaforme Biotecnologiche - PiSTEM Project”) and Fresenius Medical Care to G.C. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.