title: Tissue inhibitor of matrix metalloproteinase-1 mediates erythropoietin-induced neuroprotection in hypoxia ischemia.
abstract: Previous studies have shown that erythropoietin (EPO) is neuroprotective in both in vivo and in vitro models of hypoxia ischemia. However these studies hold limited clinical translations because the underlying mechanism remains unclear and the key molecules involved in EPO-induced neuroprotection are still to be determined. This study investigated if tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and its upstream regulator signaling molecule Janus kinase-2 (JAK-2) are critical in EPO-induced neuroprotection. Hypoxia ischemia (HI) was modeled in-vitro by oxygen and glucose deprivation (OGD) and in-vivo by a modified version of Rice-Vannucci model of HI in 10-day-old rat pups. EPO treated cells were exposed to AG490, an inhibitor of JAK-2 or TIMP-1 neutralizing antibody for 2h with OGD. Cell death, phosphorylation of JAK-2 and signal transducers and activators of transcription protein-3 (STAT-3), TIMP-1 expression, and matrix metalloproteinase-9 (MMP-9) activity were measured and compared with normoxic group. Hypoxic ischemic animals were treated one hour following HI and evaluated 48 h after. Our data showed that EPO significantly increased cell survival, associated with increased TIMP-1 activity, phosphorylation of JAK-2 and STAT-3, and decreased MMP-9 activity in vivo and in vitro. EPO's protective effects were reversed by inhibition of JAK-2 or TIMP-1 in both models. We concluded that JAK-2, STAT-3 and TIMP-1 are key mediators of EPO-induced neuroprotection during hypoxia ischemia injury.
authors.affiliation: Division of Microbiology and Molecular Genetics, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
authors.forename: Rhonda
authors.initials: R
authors.lastname: Souvenir
authors.forename: Nancy
authors.initials: N
authors.lastname: Fathali
authors.forename: Robert P
authors.initials: RP
authors.lastname: Ostrowski
authors.forename: Tim
authors.initials: T
authors.lastname: Lekic
authors.forename: John H
authors.initials: JH
authors.lastname: Zhang
authors.forename: Jiping
authors.initials: J
authors.lastname: Tang
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D016923:Cell Death / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002544:Cerebral Infarction / Q000473:pathology; D003470:Culture Media; D004797:Enzyme-Linked Immunosorbent Assay; D004921:Erythropoietin / Q000494:pharmacology*; D005260:Female; D018093:Gelatinases / Q000378:metabolism; D005947:Glucose / Q000172:deficiency; D020925:Hypoxia-Ischemia, Brain / Q000188:drug therapy* / Q000473:pathology; D007150:Immunohistochemistry; D007276:Injections, Intraventricular; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis / Q000235:genetics; D018696:Neuroprotective Agents; D016716:PC12 Cells; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000502:physiology*
chemical_list: D003470:Culture Media; D018696:Neuroprotective Agents; D019715:Tissue Inhibitor of Metalloproteinase-1; D004921:Erythropoietin; D018093:Gelatinases; D020780:Matrix Metalloproteinase 9; D005947:Glucose