Journal of Clinical Medicine (Feb 2021)

Sulfatase 2 Is Associated with Steroid Resistance in Childhood Nephrotic Syndrome

  • Shipra Agrawal,
  • Richard F. Ransom,
  • Saras Saraswathi,
  • Esperanza Garcia-Gonzalo,
  • Amy Webb,
  • Juan L. Fernandez-Martinez,
  • Milan Popovic,
  • Adam J. Guess,
  • Andrzej Kloczkowski,
  • Rainer Benndorf,
  • Wolfgang Sadee,
  • William E. Smoyer,
  • on behalf of the Pediatric Nephrology Research Consortium (PNRC)

DOI
https://doi.org/10.3390/jcm10030523
Journal volume & issue
Vol. 10, no. 523
p. 523

Abstract

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Glucocorticoid (GC) resistance complicates the treatment of ~10–20% of children with nephrotic syndrome (NS), yet the molecular basis for resistance remains unclear. We used RNAseq analysis and in silico algorithm-based approaches on peripheral blood leukocytes from 12 children both at initial NS presentation and after ~7 weeks of GC therapy to identify a 12-gene panel able to differentiate steroid resistant NS (SRNS) from steroid-sensitive NS (SSNS). Among this panel, subsequent validation and analyses of one biologically relevant candidate, sulfatase 2 (SULF2), in up to a total of 66 children, revealed that both SULF2 leukocyte expression and plasma arylsulfatase activity Post/Pre therapy ratios were greater in SSNS vs. SRNS. However, neither plasma SULF2 endosulfatase activity (measured by VEGF binding activity) nor plasma VEGF levels, distinguished SSNS from SRNS, despite VEGF’s reported role as a downstream mediator of SULF2’s effects in glomeruli. Experimental studies of NS-related injury in both rat glomeruli and cultured podocytes also revealed decreased SULF2 expression, which were partially reversible by GC treatment of podocytes. These findings together suggest that SULF2 levels and activity are associated with GC resistance in NS, and that SULF2 may play a protective role in NS via the modulation of downstream mediators distinct from VEGF.

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