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ARÁNZAZU MEDIERO Y COLS. AN. R. ACAD. NAC. FARM.

Figure 3. Over-expression of P2Y2 receptor after silencing. Immunostaining
for P2Y2 36 hours after wound (96 hours after the first siRNA instillation) where
we can observed an increase in P2Y2 expression after siRNA instillation compared
with control and Ap4A treated corneas. Green fluorescence (FITC) localizes P2Y2
receptor while in blue we can observe the nuclear staining for DAPI. Images are
managed at a magnification of 40X.

4. DISCUSSION

As we have previously mentioned, the cornea is formed by five
to six different layers, including the outer one, the epithelium. The
distribution of the purinergic receptors present in the cornea revealed
that P2Y1, P2Y2, P2Y4 and P2Y6 receptor are present this part of the
eye (8).

The present experimental work confirms the location of the P2Y2
receptor after corneal wound healing and how when using a siRNA
against this receptor there is an initial disappearance of the receptor
followed by an over-expression of this protein.

The presence of the P2Y2 receptor in the epithelium is related
to the ability of some nucleotides to increase the rate of re-
epithelialization after a corneal wound (6). The involvement of
metabotropic P2 receptors in corneal wound healing has been also
reported by other groups and in all the cases the different researchers
report that ATP, UTP and Ap4A accelerate the rate of healing (9-11).

Our IHC results reveal that after wounded, the P2Y2 staining in
Ap4A treated lessons is less intense that in control wounds. As happens

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