title: Deletion of Nuclear Localizing Signal Attenuates Proinflammatory Activity of Prothymosin-Alpha and Enhances Its Neuroprotective Effect on Transient Ischemic Stroke.
abstract: Post-ischemic inflammation plays an important role in the progression of ischemia/reperfusion injuries. Prothymosin-α (ProT) can protect cells from necrotic death following ischemia; however, its immunostimulatory actions may counteract the neuroprotective effect. We proposed that ProTΔNLS, synthesized by deleting its nuclear localizing signal (NLS) at the C-terminal of ProT, can attenuate the immunostimulatory activity and has more salient neuroprotective effect. In this study, we examined the therapeutic effects of ProT and ProTΔNLS in a transient middle cerebral artery occlusion (tMCAO) model of rats. Rats that had sustained 90 min of tMCAO were treated with GST-vehicle, ProT, or ProTΔNLS. Therapeutic outcomes were evaluated by infarction volume assay and behavioral assessment. Changes to inflammatory mediators, including tumor necrosis factor α (TNF-α), interleukin-10 (IL-10), and myeloperoxidase (MPO) were evaluated by enzyme-linked immunosorbent assay. Activated matrix metalloproteinases 2 (MMP-2) and 9 (MMP-9) levels were evaluated by gelatin zymography. Microglial activation was identified by double-immunostaining for Iba-1 and CD68. Our results showed that while both ProT and ProTΔNLS reduce infarction volume and improve functional outcome, ProTΔNLS provides the best therapeutic outcome. ProT increases TNF-α but decreases IL-10 secretion after ischemic injury, reflecting its pro-inflammatory activity. ProTΔNLS suppresses expression of TNF-α, MPO, and activity of MMPs in ischemic brain tissue. It also suppresses activation of microglia in penumbral cortex. These data demonstrate the immunesuppressive activities of ProTΔNLS. In conclusion, ProT has pro-inflammatory effect that may counteract its neuroprotective effect. Deletion of NLS from ProT may attenuate post-ischemic inflammation and enhance the neuroprotective effects of ProT.
authors.affiliation: Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.|Division of Neurosurgery, Department of Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Liang-Chao
authors.initials: LC
authors.lastname: Wang
authors.affiliation: Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Chao-Liang
authors.initials: CL
authors.lastname: Wu
authors.affiliation: Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Ya-Yun
authors.initials: YY
authors.lastname: Cheng
authors.affiliation: Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan. kjtsai@mail.ncku.edu.tw.|Center of Clinical Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan. kjtsai@mail.ncku.edu.tw.
authors.forename: Kuen-Jer
authors.initials: KJ
authors.lastname: Tsai
mesh_terms: D000818:Animals; D017353:Gene Deletion; D002546:Ischemic Attack, Transient / Q000235:genetics / Q000378:metabolism* / Q000517:prevention & control; D008297:Male; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D019913:Nuclear Localization Signals / Q000172:deficiency* / Q000235:genetics; D011498:Protein Precursors / Q000235:genetics / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020521:Stroke / Q000235:genetics / Q000378:metabolism* / Q000517:prevention & control; D013947:Thymosin / Q000031:analogs & derivatives* / Q000235:genetics / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D018696:Neuroprotective Agents; D019913:Nuclear Localization Signals; D011498:Protein Precursors; C040782:prothymosin alpha; D013947:Thymosin
keywords: Inflammation; Neuroprotection; Prothymosin; Stroke