Candesartan Augments Ischemia-Induced Proangiogenic State and Results in Sustained Improvement After Stroke

Abstract

Objective We have shown that acute treatment with candesartan in an experimental model of stroke resulted in vascular protection and improved outcomes at 24 hours post-stroke, but the mechanisms are unknown. We now examine effects of candesartan on proangiogenic factors and 7-day outcomes using the same treatment paradigm. Methods Male Wistar rats underwent 3 hours of middle cerebral artery occlusion (MCAO), followed by reperfusion. A single dose of candesartan 1mg/kg IV was given at reperfusion. Animals received neurobehavioral testing before MCAO, at 24 hours after MCAO, and at 7 days. BP was measured by telemetry. Animals sacrificed at 24 hours had tissue and spinal fluid (CSF) collected for matrix metalloproteinase (MMP) activity, vascular endothelial growth factor (VEGF) expression, and tube formation assay. Neurobehavioral testing included elevated-body swing test (EBST), Bederson, beam walk, and paw grasp. Cerebrovascular density was quantified using immunohistochemistry at 24 h and 7 days. Results MMP-2 activity and VEGF expression were higher (p=0.035, p=0.042, respectively) and CSF was significantly more proangiogenic (5X tube formation; p=0.002) in the candesartan group at 24 hours. Although no difference was seen in infarct size at 7 days, treatment improved Bederson scores (2.1 vs. 2.9, p=0.0083), EBST (22.9 vs. 39.4, p=0.021) and paw grasp (1.29 vs. 2.88, p=0.0001) at 7 days. Candesartan treatment resulted in increased vascular density in the striatum at 7 days (p=0.037). Conclusion Candesartan after reperfusion augments ischemia-induced angiogenic state and provides long-term benefits. The beneficial effects may involve vascular protection and enhancement of early angiogenic remodeling.

Candesartan Induces a Prolonged Proangiogenic Effect and Augments Endothelium-Mediated Neuroprotection after Oxygen and Glucose Deprivation: Role of Vascular Endothelial Growth Factors A and B

“…A total of 30 adult male Wistar rats (Charles River Laboratories, Wilmington, MA), weighing 280-300 g, were subjected to 90-minute middle cerebral artery occlusion (MCAO) using a intraluminal suture model, as previously described (Kozak et al, 2009). Successful MCAO was confirmed by the presence of hemiparesis prior to reperfusion.…”

“…The ability of endothelial cells to align into tube-like structures was measured using the Matrigel (BD Biosciences, San Jose, CA) tube formation assay as previously described (Kozak et al, 2009). To measure the proangiogenic potential of CSF, confluent cells were serum starved overnight, harvested, and suspended in a mixture of serum-free EMEM and growth factor-reduced Matrigel in a 70:30 ratio.…”

AT1 Receptor Antagonism Is Proangiogenic in the Brain: BDNF a Novel Mediator

“…Angiotensin II type 1 receptor blockers (ARBs) have been shown to be vascular protective and seem to have a particularly robust effect in reducing the incidence of cerebrovascular events (Dahlöf et al, 2002;Engelhorn et al, 2004;Kozak et al, 2009). Acutely, ARBs have been shown to improve outcome in experimental stroke (Fagan et al, 2006), and the long-term functional benefit was accompanied by an augmented proangiogenic state (Kozak et al, 2009).…”

“…Acutely, ARBs have been shown to improve outcome in experimental stroke (Fagan et al, 2006), and the long-term functional benefit was accompanied by an augmented proangiogenic state (Kozak et al, 2009). This angiogenic effect was only partially attributed to an increase in vascular endothelial growth factor (VEGF) expression (Kozak et al, 2009). Of interest, the angiogenic response of candesartan was maintained even in nonstroked rats (Kozak et al, 2009).…”

“…This angiogenic effect was only partially attributed to an increase in vascular endothelial growth factor (VEGF) expression (Kozak et al, 2009). Of interest, the angiogenic response of candesartan was maintained even in nonstroked rats (Kozak et al, 2009). Subsequently, it was demonstrated that candesartan increased the expression of a number of genes for proangiogenic growth factors, including brain-derived neurotrophic factor (BDNF), after experimental cerebral ischemia (Guan et al, 2011).…”