Carbon monoxide produced by heme oxygenase-1 in response to nitrosative stress induces expression of glutamate-cysteine ligase in PC12 cells via activation of phosphatidylinositol 3-kinase and Nrf2 signaling.
Induction of heme oxygenase-1 (HO-1) expression has been associated with adaptive cytoprotection against a wide array of toxic insults, but the underlying molecular mechanisms remain largely unresolved. In this study, we investigated the potential role of carbon monoxide (CO), one of the by-products of the HO-1 reaction, in the adaptive survival response to peroxynitrite-induced PC12 cell death. Upon treatment of rat pheochromocytoma (PC12) cells with the peroxynitrite generator 3-morpholinosydnonimine hydrochloride (SIN-1), the cellular GSH level decreased initially, but was gradually restored to the basal level. This was accompanied by increased expression of the catalytic subunit of glutamate-cysteine ligase (GCLC), the rate-limiting enzyme in GSH biosynthesis. The SIN-1-induced GCLC up-regulation was preceded by induction of HO-1 and subsequent CO production. Inhibition of HO activity by zinc protoporphyrin IX or knockdown of HO-1 gene expression by small interfering RNA abrogated the up-regulation of GCLC expression and the subsequent GSH restoration induced by SIN-1. In contrast, additional exposure to the CO-releasing molecule (CO-RM) restored the GSH level previously reduced by inhibition of CO production using zinc protoporphyrin IX. Furthermore, CO-RM treatment up-regulated GCLC expression through activation of Nrf2. The CO-RM-induced activation of Nrf2 was under the control of the phosphatidylinositol 3-kinase/Akt signaling pathway. In conclusion, CO produced by HO-1 rescues PC12 cells from nitrosative stress through induction of GCLC, which is mediated by activation of phosphatidylinositol 3-kinase/Akt and subsequently Nrf2 signaling.
Li
Mei-Hua
MH
National Research Laboratory of Molecular Carcinogenesis and Chemoprevention, College of Pharmacy, Seoul National University, Seoul 151-742, South Korea.
Jang
Jung-Hee
JH
National Research Laboratory of Molecular Carcinogenesis and Chemoprevention, College of Pharmacy, Seoul National University, Seoul 151-742, South Korea.
Na
Hye-Kyung
HK
National Research Laboratory of Molecular Carcinogenesis and Chemoprevention, College of Pharmacy, Seoul National University, Seoul 151-742, South Korea.
Cha
Young-Nam
YN
Department of Pharmacology and Toxicology, College of Medicine, Inha University, Incheon 382-751, South Korea.
Surh
Young-Joon
YJ
National Research Laboratory of Molecular Carcinogenesis and Chemoprevention, College of Pharmacy, Seoul National University, Seoul 151-742, South Korea; Cancer Research Institute, Seoul National University, Seoul 110-799, South Korea. Electronic address: surh@plaza.snu.ac.kr.
D000818:Animals; D002248:Carbon Monoxide / Q000378:metabolism*; D020134:Catalytic Domain; D002470:Cell Survival / Q000187:drug effects; D005721:Glutamate-Cysteine Ligase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism*; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D016716:PC12 Cells; D030421:Peroxynitrous Acid / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011524:Protoporphyrins / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000494:pharmacology; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects; D013312:Stress, Physiological / Q000139:chemically induced / Q000378:metabolism
D051267:NF-E2-Related Factor 2; C495637:Nfe2l2 protein, rat; D020030:Nitric Oxide Donors; D011524:Protoporphyrins; D034741:RNA, Small Interfering; D030421:Peroxynitrous Acid; C002385:linsidomine; D002248:Carbon Monoxide; C028025:protoporphyrin IX; D008981:Molsidomine; D006419:Heme Oxygenase (Decyclizing); C491523:Hmox1 protein, rat; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D005721:Glutamate-Cysteine Ligase