CD36 Promotes Podocyte Apoptosis by Activating the Pyrin Domain-Containing-3 (NLRP3) Inflammasome in Primary Nephrotic Syndrome

Med Sci Monit. 2018 Sep 27:24:6832-6839. doi: 10.12659/MSM.909810.

Abstract

BACKGROUND CD36 plays a critical role in many sterile inflammatory diseases, including type 2 diabetes mellitus, atherosclerosis, and primary nephrotic syndrome. This study investigated whether CD36 activates the nucleotide-binding domain leucine-rich repeat-containing family, pyrin domain-containing-3 (NLRP3) inflammasome and promotes podocytes apoptosis in primary nephrotic syndrome. MATERIAL AND METHODS The mouse podocyte cell line MPC5 was used as a model. mRNA and protein expression of CD36 and NLRP3 was quantified by real-time PCR and Western blotting, respectively. Levels of caspase-1 activity and total cholesterol were determined using commercial kits. Intracellular lipid droplets were detected by Oil Red O staining. CD36 expression was also examined in nephrotic mouse kidney tissue by immunohistochemistry and immunofluorescence. Intracellular lipid droplet was examined by Oil Red O staining. RESULTS CD36 expression was increased in nephrotic mouse kidney tissue. Treatment with interleukin-1b increased expression of CD36 and total cholesterol in MPC5 cells. Moreover, this treatment increased expression of NLRP3 and the percentage of apoptotic cells, both of which were inhibited by co-treatment with an anti-CD36 antibody. CONCLUSIONS CD36 might play an important role in podocyte apoptosis by activating the NLRP3 inflammasome in primary nephrotic syndrome.

MeSH terms

  • Animals
  • Apoptosis / physiology
  • CD36 Antigens / metabolism*
  • Cell Line
  • Disease Models, Animal
  • Inflammasomes / metabolism
  • Interleukin-1beta / metabolism
  • Male
  • Mice
  • Mice, Inbred BALB C
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism*
  • Nephrotic Syndrome / metabolism*
  • Nephrotic Syndrome / pathology
  • Podocytes / metabolism*
  • Podocytes / pathology
  • Pyrin Domain
  • Signal Transduction

Substances

  • CD36 Antigens
  • Inflammasomes
  • Interleukin-1beta
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Nlrp3 protein, mouse