scholarly journals Rosiglitazone Promotes White Matter Integrity and Long-Term Functional Recovery After Focal Cerebral Ischemia

Stroke ◽  
2015 ◽  
Vol 46 (9) ◽  
pp. 2628-2636 ◽  
Author(s):  
Lijuan Han ◽  
Wei Cai ◽  
Leilei Mao ◽  
Jia Liu ◽  
Peiying Li ◽  
...  
Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Shubei Ma

Objectives: Stroke is the leading cause of long term neurological disability with limited therapeutic options. Human recombinant tissue plasminogen activator (tPA) is currently the only FDA approved drug for the thrombolytic treatment of ischemic stroke. Emerging evidence suggests that the effects of tPA in ischemic brain may extend beyond its thrombolytic activity. In this study, we investigated the role of tPA in long term stroke recovery. Methods: Cortical infarct was induced by distal middle cerebral artery occlusion (dMCAO) in tPA knockout (KO) and wild type (WT) mice. Sensorimotor functions were evaluated at 3-35 days after dMCAO. White matter integrity was assessed by luxol fast blue staining, immunohistochemistry for SMI-32, and diffusion tensor imaging (DTI). The neuronal tracer biotinylated dextran amine (BDA) was used to label the corticorubral tract and the corticospinal tract. For rescue experiment, tPA (2mg/kg) was delivered intranasally to tPA KO mice once a day for 14 days starting 6h after dMCAO. Results: Infarct volume was comparable between tPA KO and WT mice after dMCAO. Sensorimotor deficits after dMCAO were exacerbated in tPA KO mice than WT mice. tPA KO mice also showed more severe demyelination in post-stroke white matter and reduced axonal sprouting at 35 days after dMCAO compared to WT mice. DTI studies revealed deteriorated white matter integrity in tPA KO mice, as manifested by decreased fractional anisotropy. Intranasal delivery of tPA after dMCAO rescued the neurological phenotype shown by tPA KO mice. Conclusion: Endogenous tPA promotes white matter integrity and is essential for functional recovery after ischemic stroke. tPA may be a novel neurorestorative therapy for stroke recovery.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Yongfang Li ◽  
Longlong Luo ◽  
Zhijun Zhang ◽  
Yaohui Tang ◽  
Guo-Yuan Yang

Objectives: White matter injury aggravates neurological and cognitive impairment in experimental ischemic stroke. M2 microglia promote oligodendrocyte precursor cells survival and differentiation, and further enhance white matter repair. However, the molecular mechanism is unclear. Here, we explored the effect and mechanism of M2 microglia-derived exosomes on white matter repair after focal cerebral ischemia in mice. Methods: Microglia BV2 cells were polarized to M2 phenotype by IL-4 stimulation. Exosomes were isolated from M2 microglia (M2-Exo) and unstimulated microglia as a control (M0-Exo). M2-Exo and M0-Exo (100 μg) were intravenously injected after 90-minute middle cerebral artery occlusion in mice (n=72). Brain atrophy volume and neuro behavioral outcomes were examined in 28 days following focal cerebral ischemia. Oligodendrocyte precursor cells survival, differentiation and white matter integrity were evaluated. Exosomal miRNA and target gene were further examined to explore molecular mechanism. Results: M2-Exo treatment promoted sensorimotor and memory function recovery ( p <0.05), and further reduced brain atrophy compared to the M0-Exo control group ( p <0.001). Immunostaining showed that M2-Exo increased the number of BrdU + /Pdgfr-α + and BrdU + /adenomatous polyposis coli + cells, enhanced myelin basic protein fluorescence-intensity compared to the control ( p <0.05). M2-Exo increased oligodendrocyte precursor cell survival under OGD in vi tro , ( p <0.05) and differentiation ( p <0.05). Exosomal miRNA sequencing and PCR identified that miR-23a-5p was enriched in M2-Exo. Conclusion: Our results showed that M2-Exo treatment enhanced oligodendrocyte precursor cell survival and differentiation, further promoted white matter repair and long-term functional recovery, suggesting that M2-Exo is a novel therapeutic strategy for the white matter repair after ischemic brain injury.


2018 ◽  
Vol 115 (39) ◽  
pp. E9230-E9238 ◽  
Author(s):  
Yuguo Xia ◽  
Hongjian Pu ◽  
Rehana K. Leak ◽  
Yejie Shi ◽  
Hongfeng Mu ◽  
...  

Recombinant tissue plasminogen activator (tPA) is a Food and Drug Administration-approved thrombolytic treatment for ischemic stroke. tPA is also naturally expressed in glial and neuronal cells of the brain, where it promotes axon outgrowth and synaptic plasticity. However, there are conflicting reports of harmful versus neuroprotective effects of tPA in acute brain injury models. Furthermore, its impact on white matter integrity in preclinical traumatic brain injury (TBI) has not been thoroughly explored, although white matter disruption is a better predictor of long-term clinical outcomes than focal lesion volumes. Here we show that the absence of endogenous tPA in knockout mice impedes long-term recovery of white matter and neurological function after TBI. tPA-knockout mice exhibited greater asymmetries in forepaw use, poorer sensorimotor balance and coordination, and inferior spatial learning and memory up to 35 d after TBI. White matter damage was also more prominent in tPA knockouts, as shown by diffusion tensor imaging, histological criteria, and electrophysiological assessments of axon conduction properties. Replenishment of tPA through intranasal application of the recombinant protein in tPA-knockout mice enhanced neurological function, the structural and functional integrity of white matter, and postinjury compensatory sprouting in corticofugal projections. tPA also promoted neurite outgrowth in vitro, partly through the epidermal growth factor receptor. Both endogenous and exogenous tPA protected against white matter injury after TBI without increasing intracerebral hemorrhage volumes. These results unveil a previously unappreciated role for tPA in the protection and/or repair of white matter and long-term functional recovery after TBI.


2015 ◽  
Vol 24 (2) ◽  
pp. 183-190 ◽  
Author(s):  
Miyeoun Song ◽  
Young-Ju Kim ◽  
Yoon-Ha Kim ◽  
Jina Roh ◽  
Eun-Cheol Kim ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document