Epigenetic Modulation of Gremlin-1/NOTCH Pathway in Experimental Crescentic Immune-Mediated Glomerulonephritis

Lucia Tejedor-Santamaria1,2, Jose Luis Morgado-Pascual1,2, Laura Marquez-Exposito1,2

  • 1Cellular Biology in Renal Diseases Laboratory, IIS-Fundación Jiménez Díaz, Universidad Autónoma Madrid, 28040 Madrid, Spain.

Insights

Bromodomain and extraterminal domain (BET) inhibitors, a novel epigenetic drug class, show promise in treating crescentic glomerulonephritis by regulating Gremlin-1 and the NOTCH pathway, offering potential new therapies for this severe kidney disease.

Area of Science:

  • Nephrology
  • Immunology
  • Epigenetics

Background:

  • Crescentic glomerulonephritis is a severe autoimmune kidney disease with limited treatment options and high rates of end-stage renal disease.
  • Current immunosuppressive therapies have modest efficacy and significant side effects.
  • Epigenetic drugs, specifically bromodomain and extraterminal domain (BET) inhibitors (iBETs), represent a potential new therapeutic avenue.

Purpose of the Study:

  • To investigate the therapeutic potential of iBETs in experimental crescentic glomerulonephritis.
  • To determine if iBETs can modulate Gremlin-1 expression, a marker of disease progression.
  • To explore the role of the NOTCH pathway in the protective effects of iBETs.

Main Methods:

  • Utilized a mouse model of anti-glomerular basement membrane nephritis induced by nephrotoxic serum (NTS).
  • Administered the iBET JQ1 to NTS-injected mice.
  • Performed chromatin immunoprecipitation assays to assess BRD4 binding to the Gremlin-1 promoter.
  • Analyzed gene expression of Gremlin-1, Hes-1, and Hey-1.

Main Results:

  • JQ1 treatment inhibited renal Gremlin-1 overexpression in NTS-injected mice.
  • iBET JQ1 diminished glomerular damage and restored podocyte numbers.
  • BRD4 was found to bind the Gremlin-1 gene promoter in injured kidneys, indicating epigenetic regulation.
  • JQ1 blocked BRD4 binding, inhibited Gremlin-1 transcription, and modulated NOTCH pathway gene expression (Hes-1, Hey-1).

Conclusions:

  • iBETs, like JQ1, can epigenetically regulate Gremlin-1 expression in experimental crescentic glomerulonephritis.
  • The beneficial effects of iBETs involve modulation of the NOTCH pathway.
  • Epigenetic therapies targeting BET proteins offer a promising strategy for treating rapidly progressive crescentic glomerulonephritis.