Effects of the PPARgamma activator pioglitazone on p38 MAP kinase and IkappaBalpha in the spinal cord of a transgenic mouse model of amyotrophic lateral sclerosis.
Emerging evidence suggests the involvement of programmed cell death and inflammation in amyotrophic lateral sclerosis (ALS). To assess molecular pathological effects of the anti-inflammatory peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist pioglitazone in ALS, we verified changes in the population of neurons, astrocytes, and microglia in the ventral horns of spinal cord lumbar segments from the pioglitazone-treated and non-treated groups of mice carrying a transgene for G93A mutant human superoxide dismutase-1 (SOD1) (ALS mice) and non-transgenic littermates (control mice), performed immunohistochemical and immunoblot analyses of PPARgamma, active form of phosphorylated p38 mitogen-activated protein kinase (p-p38) and inhibitor of nuclear factor-kappaB (NF-kappaB)-alpha (IkappaBalpha) in the spinal cords, and compared the results between the different groups. Image analysis revealed that optical density of NeuN-immunoreactive neurons was significantly lower in the non-treated groups of presymptomatic and advanced ALS mice than in the non-treated groups of age-matched control mice and was recovered with pioglitazone treatment, and that optical densities of GFAP-immunoreactive astrocytes and Iba1-immunoreactive microglia were significantly higher in the non-treated group of advanced ALS mice than in the non-treated group of control mice and were recovered with pioglitazone treatment. Immunohistochemical analysis demonstrated that immunoreactivities for PPARgamma and p-p38 were mainly localized in neurons, and that IkappaBalpha immunoreactivity was mainly localized in astrocytes and microglia. Immunoblot analysis showed that pioglitazone treatment resulted in no significant change in nuclear PPARgamma-immunoreactive density, a significant decrease in cytosolic p-p38-immunoreactive density, and a significant increase in cytosolic IkappaBalpha-immunoreactive density. Our results suggest that pioglitazone protects motor neurons against p38-mediated neuronal death and NF-kappaB-mediated glial inflammation via a PPARgamma-independent mechanism.
Shibata
Noriyuki
N
Department of Pathology, Tokyo Woman's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, Japan. shibatan@research.twmu.ac.jp
Kawaguchi-Niida
Motoko
M
Yamamoto
Tomoko
T
Toi
Sono
S
Hirano
Asao
A
Kobayashi
Makio
M
D000690:Amyotrophic Lateral Sclerosis / Q000188:drug therapy* / Q000473:pathology; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000096:biosynthesis; D004268:DNA-Binding Proteins; D004195:Disease Models, Animal; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000096:biosynthesis; D006801:Humans; D020672:I-kappa B Proteins / Q000187:drug effects*; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008840:Microfilament Proteins; D017628:Microglia / Q000187:drug effects / Q000378:metabolism; D009154:Mutation; D000072000:NF-KappaB Inhibitor alpha; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009687:Nuclear Proteins / Q000096:biosynthesis; D047495:PPAR gamma / Q000187:drug effects / Q000378:metabolism; D000077205:Pioglitazone; D013116:Spinal Cord / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D013482:Superoxide Dismutase / Q000235:genetics; D000072105:Superoxide Dismutase-1; D045162:Thiazolidinediones / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000187:drug effects*
C491049:Aif1 protein, mouse; D000893:Anti-Inflammatory Agents; D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D005904:Glial Fibrillary Acidic Protein; D020672:I-kappa B Proteins; D008840:Microfilament Proteins; C000606204:NFKBIA protein, human; D009419:Nerve Tissue Proteins; C492380:NeuN protein, mouse; C000606205:Nfkbia protein, mouse; D009687:Nuclear Proteins; D047495:PPAR gamma; C000606290:SOD1 protein, human; D045162:Thiazolidinediones; D000072000:NF-KappaB Inhibitor alpha; C000606291:Sod1 protein, mouse; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D048051:p38 Mitogen-Activated Protein Kinases; D000077205:Pioglitazone