CU06-1004 (endothelial dysfunction blocker) ameliorates astrocyte end-feet swelling by stabilizing endothelial cell junctions in cerebral ischemia/reperfusion injury

Abstract

Cerebral ischemia, or stroke, is widespread leading cause of death and disability. Surgical and pharmacological interventions that recover blood flow are the most effective treatment strategies for stroke patients. However, restoring the blood supply is accompanied by severe reperfusion injury, with edema and astrocyte end-feet disruption. Here, we report that the oral administration of CU06-1004 (previously Sac-1004), immediately after onset of ischemia/reperfusion (I/R), ameliorated cerebral damage. CU06-1004 stabilized blood-brain barrier by inhibiting the disruption of the tight junction-related protein zona occludens-1 and the cortical actin ring in endothelial cells (ECs) after I/R. Interestingly, CU06-1004 significantly suppressed astrocyte end-feet swelling following I/R, by reducing aquaporin 4 and connexin 43 levels, which mediates swelling. Furthermore, the degradation of β1-integrin and β-dystroglycan, which anchors to the cortical actin ring in ECs, was inhibited by CU06-1004 administration after I/R. Consistently, CU06-1004 administration following I/R also suppressed the loss of laminin and collagen type IV, which bind to the cortical actin ring anchoring proteins. Unlike the protective effects of CU06-1004 in ECs, astrocyte viability and proliferation were not directly affected. Taken together, our observations suggest that CU06-1004 inhibits I/R-induced cerebral edema and astrocyte end-feet swelling by maintaining EC junction stability. Key messages • CU06-1004 ameliorates I/R-induced cerebral injury. • EC junction integrity was stabilized by CU06-1004 treatment after I/R. • CU06-1004 reduces astrocyte end-feet swelling following I/R. • EC junction stability affects astrocyte end-feet structure maintenance after I/R. Keywords Ischemia/reperfusion injury. Blood-brain barrier. Endothelial cell. Astrocyte end-feet swelling Abbreviations α-SMA α-smooth muscle actin AQP Aquaporin BBB Blood-brain barrier BM Basement membrane CD31 Cluster of differentiation 31 COLIV Collagen type IV CX Connexin DG Dystroglycan EAAT Excitatory amino acid transporter EB Evans blue EC Endothelial cell ECM Extracellular matrix GFAP Glial fibrillary acidic protein Electronic supplementary material The online version of this article (

Laminin as a Biomarker of Blood–Brain Barrier Disruption under Neuroinflammation: A Systematic Review

“…The distribution of the studies, according to the pathological model, was as follows: eight studies on cerebral ischemia, mostly induced by cerebral artery occlusion [ 30 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ], five studies in cerebral hemorrhage induced by different methods [ 40 , 41 , 42 , 43 , 44 ], five studies on TBI, mostly by controlled cortical impact (CCI) [ 45 , 46 , 47 , 48 , 49 ], three studies combining cerebral ischemia and AD [ 50 , 51 , 52 ], three studies on aging [ 53 ] or AD models, using either amyloid-β (Aβ) [ 54 ] or transgenic animals [ 55 ], two studies on the experimental autoimmune encephalomyelitis (EAE) animal model for MS, induced by immunization with myelin oligodendrocyte glycoprotein (MOG) [ 56 , 57 ], three studies on status epilepticus (SE), induced with lithium chloride (LiCl)/pilocarpine or kainic acid (KA) treatment [ 58 , 59 , 60 ], five studies using diverse pharmacological or toxicological agents such as 3,4-methylenedioxymethamphetamine (MDMA), methamphetamine (METH), 3-chloro-1,2-propanediol, LPS, and glutaric acid (GA) [ 61 , 62 , 63 , 64 , 65 ], two studies involving pathogen-induced diseases, one in toxoplasmosis and another in human immunodeficiency virus (HIV) [ 66 , 67 ], one study which induced cognitive dysfunction by laparotomy [ 68 ], and one study which used the platelet-derived growth factor receptor β (PDGFRβ) +/− knockout model [ 69 ]. The three studies that combined stroke and AD were assigned to an independent category rather than being included in either stroke or AD categories.…”

“…Eight studies conducted on different stroke or ischemia animal models met the inclusion criteria and were incorporated in this systematic review. Two articles used a permanent middle cerebral artery occlusion (MCAO) model (one with direct injury [ 30 ] and the other with ferric chloride [ 34 ]), while five induced transient ischemia (four in the middle cerebral artery [ 35 , 37 , 38 , 39 ] and one in both common carotid arteries [ 36 ]). Transient ischemia times ranged from 15 min to 90 min.…”

“…In addition, no changes were observed in laminin α2 and α4 subunits 12 h after the reduction in blood flow [ 38 ]. Nonetheless, at 16 h post transient MCAO, a significant reduction in laminin was found [ 35 ], which persisted from 16 h until 7 days after transient MCAO [ 36 ]. In the study of McColl and colleagues [ 37 ], neuronal laminin (but not vessel laminin) was found to be significantly reduced 24 h after transient MCAO both in the animals which had MCAO and in those which had MCAO plus IL-1β challenge.…”

Inhibition of p38 MAPK Mitigates Lung Ischemia Reperfusion Injury by Reducing Blood–Air Barrier Hyperpermeability

“…F-actin is the main cytoskeletal protein involved in cellular contraction, which is important for maintaining normal morphology and function (Deng et al, 2018). LIRI induces degradation of tight junctions by downregulating ZO-1 and VE-cadherin while stress fibers accumulate, compromising the endothelial barrier (Kim et al, 2020).…”

Astrocytes in rare neurological conditions: Morphological and functional considerations

“…Hence, the astrocytic morphology might resemble the one in Alzheimer's disease if there is progress to dementia. Studies have showed that there are reductions in astrocytic GLUT1 and lactate transporters, as well as retraction of astrocyte end‐feet and swelling consistent with neurovascular uncoupling, preceded wide‐spread β‐amyloid plaque pathology (Kim et al, 2020; Merlini et al, 2011). In addition, astrocytosis and subsequent glial scar formation has been shown in mice to functionally protect the brain from inflammation and infarct spread in brain ischemia (L. Li et al, 2008).…”