Purchase this article with an account.
Aliaa Abdelhakim, Muhammad Anwar, Lauren Rosko, James Todaro, Takayuki Nagasaki, Robert Ludwig, Martha Welch, Bryan J Winn; The Role of the Oxytocin and Secretin Receptors in Modulating Inflammation in Ocular Surface Tissues. Invest. Ophthalmol. Vis. Sci. 2017;58(8):3948.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Inflammatory diseases of the ocular surface occur with high prevalence. Previous studies have shown that co-administration of oxytocin and secretin reduced gut inflammation elicited by experimental colitis in rodents. Here, we investigate the presence of the oxytocin and secretin receptors (OXTR and SCTR) on the corneal and conjunctival surfaces and their role as possible modulators of ocular surface inflammation.
We used immunofluorescence to localize OXTR and SCTR in paraffinated sections of rodent and human eyes, and in the SV40-HCEC human cornea cell line. To test the effects of OXTR and SCTR in vitro, we created a cell culture model of ocular surface inflammation by adding the inflammatory cytokine TNF-α to SV40-HCEC cells and measuring the resultant levels of the inflammatory marker ICAM-1 by Western blot. The program ImageJ was used to quantify signals.
OXTR was expressed in the superficial layer of human corneal and conjunctival epithelia (Fig 1a); this pattern was also observed in rat eyes. OXTR was also expressed in SV40-HCEC cells. SCTR was detected in the human and rat cornea (Fig 1b) and in SV40-HCEC cells. Expression of both receptors was confirmed in SV40-HCEC lysate by Western blotting. To test the anti-inflammatory effects of oxytocin and secretin in vitro, we measured ICAM-1 expression levels in SV40-HCEC cells after individual or combined oxytocin and secretin treatment. Levels of ICAM-1 were compared with TNF-α alone, TNF-α plus oxytocin, TNF-α plus secretin, or TNF-α with both hormones added (Fig 1c). ICAM-1 levels 3 hours after addition of oxytocin were ~40% of that measured with TNF-α treatment alone. Secretin similarly decreased ICAM-1 levels to ~40% at the same time point. The combination of the two drugs resulted in no further reduction in ICAM-1 levels. Effects of the hormones were transient with the maximal effect at 3-4 hours after hormone addition.
OXTR and SCTR are present on humans and rodent ocular surface tissues. Addition of oxytocin and/or secretin appears to decrease inflammation in cell culture as measured by ICAM-1 levels. These data suggest an anti-inflammatory role for these receptors on the ocular surface and possible use as therapeutic targets in ocular surface disease.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.
Figure 1. a: OXTR expression, human cornea. b: SCTR expression, human cornea. c: Effect of oxytocin and secretin on ICAM-1 levels, SV40-HCEC cells.
This PDF is available to Subscribers Only