Frontiers in Bioscience-Landmark (FBL) is published by IMR Press from Volume 26 Issue 5 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.
Academic Editor: John Zhang
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors of the nuclear hormone receptor superfamily. The 3 PPAR isoforms (alpha, delta/beta and gamma) are known to control many physiological functions including glucose absorption, lipid balance, and cell growth and differentiation. Of interest, PPAR-gamma activation was recently shown to mitigate the inflammation associated with chronic and acute neurological insults. Particular attention was paid to test the therapeutic potential of PPAR agonists in acute conditions like stroke, spinal cord injury (SCI) and traumatic brain injury (TBI), in which massive inflammation plays a detrimental role. While 15d-prostaglandin J2 (15d PGJ2) is the natural ligand of PPAR-gamma, the thiazolidinediones (TZDs) are potent exogenous agonists. Due to their insulin-sensitizing properties, 2 TZDs rosiglitazone and pioglitazone are currently FDA-approved for type-2 diabetes treatment. Recent studies from our laboratory and other groups have shown that TZDs induce significant neuroprotection in animal models of focal ischemia and SCI by multiple mechanisms. The beneficial actions of TZDs were observed to be both PPAR-gamma-dependent as well as -independent. The major mechanism of TZD-induced neuroprotection seems to be prevention of microglial activation and inflammatory cytokine and chemokine expression. TZDs were also shown to prevent the activation of pro-inflammatory transcription factors at the same time promoting the anti-oxidant mechanisms in the injured CNS. This review article discusses the multiple mechanisms of TZD-induced neuroprotection in various animal models of CNS injury with an emphasis on stroke.