Abstract
Purpose :
To investigate the effects of loss of transient receptor potential vanilloid 4 (TRPV4) in the development of neovascularization in a corneal stroma in mice. TRPV4 is a cation channel type receptor involved in febrile hyperalgesia and pain as well as multiple cell behavior modulation as a mechanosensor.
Methods :
(1) Corneal neovascularization from the limbal vessels was induced by cauterization of the central cornea of an eye of both C57BL/6 (WT) mice (n = 24) and TRPV4-null (KO) mice (n = 25) by a disposable tool of Accu-temp. The eye was processed for cryosectioning and were examined by using immunohistochemistry. Expression of angiogenic growth factors and inflammatory cell markers were examined in RNA samples derived from day 3 tissues and uninjured ones by using TaqMan real time-RT-PCR. (2) We employed in vitro assay of angiogenic activity of human umbilical vein endothelial cell (HUVEC). The culture was maintained in the routine culture condition in the presence of VEGF-A as an angiogenesis inducer in the presence or absence of a TRPV4 antagonist (HC-067047). The length of tube-like structure formation was compared and examined after 12 hours.
Results :
(1) The length of the neovascularization from the limbus was less in KO mice as compared with WT mice at day 7 as revealed by CD31 immunostaining. Expression of mRNAs of F4/80 macrophage antigen was significantly less in a KO cornea as compared with a WT cornea at day 3. (2) The angiogenic activity in HUVEC was significantly suppressed by the addition of TRPV4 antagonist in a concentration-dependent manner.
Conclusions :
TRPV4 signal is involved in macrophage infiltration and angiogenesis process in a mouse cornea.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.