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Targeting inflammation in the retina: a new therapeutic approach in diabetic retinopathy

A

B

Figure 5. R-DS-ONJ decreased the pro-inflammatory signaling pathways induced by LPS in Bv-2 cells. Bv-2 cells were treated with

LPS (200 ng/ml) in the absence or presence of R-DS-ONJ (50 µM) for the indicated time-periods. A) Protein extracts (30 µg) were

separated by SDS-PAGE and analyzed by Western blot with antibodies against phospho-JNK, total JNK, phospho-p38 MAPK, total p38

MAPK and I?Ba. a-Tubulin was used as a loading control. Representative autoradiograms are shown (n=6 independent experiments).

The blots were quantities by scanning densitometry. The results are means ± SEM. Data were analyzed by one-way ANOVA followed by

Bonferroni t-test; *p= 0.05 LPS+R-DS-ONJ vs LPS. B) Bv-2 cells treated for 60 min with LPS in the absence or presence of R-DS-ONJ

were immunostained for p65 NF?B (green) and counterstained with DAPI (blue). Representative images are shown.

3.3. Sp2-iminosugar derived R-DS-ONJ prevented gliosis Next, we evaluated the impact of the circulating
and M1 status associated to inflammation in retinas from endotoxemia on the inflammatory markers in the retina.
db/db mice during DR Whereas in the retina of db/db mice iNOS mRNA and
protein levels peaked at 5 weeks and remained elevated up
In order to determine the appropriate time-period in to 8 weeks in comparison to age-matched db/+ controls,
which to analyze the effect of Sp2-iminosugar derived R- arginase-1 mRNA and protein levels increased at 5-6
DS-ONJ in retinal explants of db/db mice, we first study weeks and returned to basal levels at 8 weeks. These data
several parameters related to inflammation in circulation reflect the decrease in the anti-inflammatory profile of the
and in the retina in this mouse model. retina in db/db mice during DR progression (Figure 6B).

During obesity, increased intestinal permeability leads The immunofluorescence analysis in retinal sections
to the leakage of bacterial products into the circulation that revealed iNOS specific immunostaining (green) in OS
exacerbates the pro-inflammatory responses (27). Higher
levels of serum endotoxin were detected in db/db mice at 5 (outer segment), OPL (outer plexiform layer), INL (inner
weeks compared to age-matched db/+ controls (Figure
6A) and these differences were maintained up to 20 weeks. nuclear layer) and GCL (ganglion cell layer) at 5 and 8
weeks in db/db mice, being immunolabelling stronger at 8

@Real Academia Nacional de Farmacia. Spain 87