The online version of this article (https://doi.org/10.1186/s12974-018-1267-5) contains supplementary material, which is available to authorized users.
Blood–brain barrier (BBB) breakdown and inflammatory responses are the major causes of tissue-type plasminogen activator (tPA)-induced hemorrhagic transformation (HT), while high-mobility group box 1 (HMGB1) exacerbates inflammatory damage to BBB during the process of brain ischemia/reperfusion. This study aimed to investigate the change of HMGB1 after thrombolytic therapy and whether blocking HMGB1 could ameliorate the neurovasculature complications secondary to tPA treatment in stroke rats.
Sera from acute stroke patients and rats with thrombolytic therapy were collected to investigate HMGB1 secretion. Male Sprague-Dawley rats with 2 h or 4.5 h middle cerebral artery occlusion were continuously infused with tPA followed by administration of membrane permeable HMGB1-binding heptamer peptide (HBHP). The mortality rate, neurological score, HT, brain swelling, BBB permeability, and inflammatory factors were determined.
The results revealed that HMGB1 levels were elevated in both stroke patients and rats after tPA treatment. Blocking HMGB1 signaling by HBHP in the rat model of 4.5 h brain ischemia significantly attenuated tPA-related complications, including mortality rate, the degree of hemorrhage, brain swelling, neurological deficits, BBB impairment, microglia activation, and the expressions of inflammatory cytokines.
tPA treatment might induce HMGB1 secretion while blocking HMGB1 with HBHP could markedly reduce the risk of thrombolysis-associated brain hemorrhage and mortality through attenuating BBB damage and inflammatory reactions. These results indicate that HMGB1 may potentiate the risk of HT in tPA administration and that blocking HMGB1 signaling would be helpful in preventing complications brought by thrombolysis in ischemic stroke.
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Additional file 1: Figure S1. Western blot analysis indicated serum HMGB1 levels were elevated after thrombolysis in stroke patients and rats. Sera from human and rats received thrombolysis were incubated with Protein A/G MagBeads (GenScript, Piscataway, NJ) to remove immunoglobins and then the proteins were separated in SDS-PAGE gels and immunolabeled with HMGB1 antibody. (PDF 340 kb)12974_2018_1267_MOESM1_ESM.pdf
Additional file 2: Figure S2. HBHP and HMGBP could not directly interact with tPA. Biolayer interferometry binding measurements using BLItz system from ForteBio were used to detect the binding affinity of HBHP and HMGBP with tPA. (A) Proteins were biotinylated and immobilized on streptavidin-coated biosensor tips. After equilibration, the tips were probed with the interacting analytes. The complexes were dissociated by immersing the sensor into sample dilution buffer. Data were generated automatically by the Octet User Software. (B) tPA binding measurements with HMGB1 were analyzed. The results showed that the combined signals were the same as those of uncured sensor, indicating HMGB1 has no specific binding with tPA. (C) HBHP binding measurements with tPA were analyzed. The combined signals were the same as those of the uncured sensor, indicating HBHP also has no specific binding with tPA. (PDF 331 kb)12974_2018_1267_MOESM2_ESM.pdf
Group TNI of ND and S rt-PSS. Tissue plasminogen activator for acute ischemic stroke. N Engl J Med. 1995;333:1581–7. CrossRef
Fonarow GC, Smith EE, Saver JL, Reeves MJ, Bhatt DL, Grau-Sepulveda MV, et al. Timeliness of tissue-type plasminogen activator therapy in acute ischemic stroke: patient characteristics, hospital factors, and outcomes associated with door-to-needle times within 60 minutes. Circulation. 2011;123:750–8. CrossRefPubMed
Jeong H, Ji K, Kim J, Jou I, Joe E. Repair of astrocytes , blood vessels , and myelin in the injured brain: possible roles of blood monocytes. Mol. Brain. 2013;6:1. CrossRef
Ozbek D, Ozturk O, Ekinci G, Midi I. Risk of hemorrhage in ischemic stroke and its relationship with cerebral microbleeds. Clin Neurol Neurosurg Elsevier. 2018;168:112–7. CrossRef
Antoine D, Harris H. A systematic nomenclature for the redox states of high mobility group box (HMGB) proteins. Mol Med. 2014;20:1. CrossRef
Kang R, Chen R, Zhang Q, Hou W, Wu S, Cao L, et al. HMGB1 in health and disease. Mol Aspects Med Elsevier Ltd. 2014;40:1–116. CrossRef
Shi X, Li M, Huang K, Zhou S, Hu Y, Pan S, et al. HMGB1 binding heptamer peptide improves survival and ameliorates brain injury in rats after cardiac arrest and cardiopulmonary resuscitation. Neurosci IBRO. 2017;360:128–38. CrossRef
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