Connexin 43 Mediated the Angiogenesis of Buyang Huanwu Decoction via Vascular Endothelial Growth Factor and Angiopoietin-1 after Ischemic Stroke

Abstract

Buyang Huanwu decoction (BYHWD), a classical prescription for ischemic stroke, has been reported to promote angiogenesis after focal ischemia. However, the mechanisms of the contribution of BYHWD on angiogenesis are still unclear. Connexin 43 (Cx43) played important roles in the functions of neurogliovascular unit. Therefore, the aim of this study was to explore the potential role of Cx43 in angiogenesis of the ischemic brain after BYHWD treatment. Middle cerebral artery occlusion (MCAO) was used to establish the model of focal ischemia. BYHWD was administrated intragastrically twice a day after MCAO with or without Gap26 (a specific Cx43 inhibitor). Western blot, neurological deficits, immunofluorescent staining, and Evans blue dye were used to confirm the role of Cx43 in angiogenesis after BYHWD treatment. The expression levels of total Cx43 and phosphorylated Cx43 were upregulated by BYHWD and peaked at 7 days post MCAO. Inhibition of Cx43 with Gap26 significantly attenuated the protective role of BYHWD in neurological behavior. BYHWD treatment promoted angiogenesis demonstrated by increased microvascular density, upregulated vascular endothelial growth factor (VEGF), and angiopoietin-1 (Ang-1), while inhibition of Cx43 with Gap26 attenuated these effects of BYHWD. In addition, Gap26 inhibited the beneficial effect of BYHWD on blood-brain barrier (BBB) integrity. These results suggested that Cx43 mediated the angiogenesis of BYHWD via VEGF and Ang-1 after focal ischemic stroke.

No-reflow after recanalization in ischemic stroke: From pathomechanisms to therapeutic strategies

“…170 Among TCM formulas, Buyang Huanwu decoction improves no-reflow by increasing microvascular density and promoting angiogenesis by upregulating VEGF and angiopoietin-1 (Ang-1). 171 Huoxueshengluo formula promotes vascular regeneration and improves blood supply in no-reflow tissues by upregulating VEGF protein expression level. 172 Additionally, TCM formula Longzhi decoction may inhibit the excessive endoplasmic reticulum stress response in rat brains by down-regulating the expressions of glucose-related protein 78 (GRP78) and C/ EBP homologous protein (CHOP), thereby promoting angiogenesis and improving the no-reflow.…”

“…170 Among TCM formulas, Buyang Huanwu decoction improves no-reflow by increasing microvascular density and promoting angiogenesis by upregulating VEGF and angiopoietin-1 (Ang-1). 171 Huoxueshengluo formula promotes vascular regeneration and improves blood supply in no-reflow tissues by upregulating VEGF protein expression level. 172…”

Recent advances in tissue repair of the blood-brain barrier after stroke

“…The positive effects shown by BYHWD treatment are mediated by the upregulation of VEGF and Ang-1 expression by Cx43. 142 Naoluo Xintong decoction (NLXTD) treatment increases the number of EC and the expression of HIF-1α, VEGF, and VEGFR2 in the ischemic penumbra region, and its pro-angiogenic effects are closely related to the upregulation of the HIF-1α/VEGF signaling pathway. 143 Ginseng Yangrong decoction (GSYRD) was proved to promote the proliferation and migration of human umbilical vein EC in a dose-dependent manner.…”