Abstract
Endothelial cells (ECs) are key players in the development and maintenance of the vascular tree, the establishment of the blood brain barrier and control of blood flow. Disruption in ECs is an early and active component of vascular pathogenesis. However, our ability to selectively target ECs in the CNS for identification and manipulation is limited. Here, in the mouse retina, a tractable model of the CNS, we utilized a recently developed AAV-BR1 system to identify distinct classes of ECs along the vascular tree using a GFP reporter. We then developed an inducible EC-specific ectopic Connexin 43 (Cx43) expression system using AAV-BR1-CAG-DIO-Cx43-P2A-DsRed2 in combination with a mouse line carrying inducible CreERT2 in ECs. We targeted Cx43 because its loss has been implicated in microvascular impariment in numerous diseases such as diabetic retinopathy and vascular edema. GFP-labeled ECs were numerous, evenly distributed along the vascular tree and their morphology was polarized with respect to the direction of blood flow. After tamoxifen induction, ectopic Cx43 was specifically expressed in ECs. Similarly to endogenous Cx43, ectopic Cx43 was localized at the membrane contacts of ECs and it did not affect tight junction proteins. The ability to enhance gap junctions in ECs provides a precise and potentially powerful tool to treat microcirculation deficits, an early pathology in numerous diseases.
Competing Interest Statement
The authors declare no potential conflict of interest. Jakob Korbelin is listed as inventor of a patent on AAV-BR1 (#10696717) held by Boehringer Ingelheim International and serves as scientific advisor on the topic of AAV vector development.
Footnotes
Data availability statement: The data that support the findings of this study are available from the corresponding author/s upon reasonable request.
Funding statement: Supported by NIH grants R01-EY026576, R01-EY029796 and NYSDOH-C34457GG (BTS).
Conflict of interest disclosure: The authors declare no potential conflict of interest. Jakob Körbelin is listed as inventor of a patent on AAV-BR1 (#10696717) held by Boehringer Ingelheim International and serves as scientific advisor on the topic of AAV vector development.