Genetic inactivation of DUSP3/VHR attenuates kidney damage and inflammation following ischemia/reperfusion in mouse

P. Rowart, L. Poma, S. Rahmouni, J.M. Krzesinski, F. Jouret

Friday 16 march 2018

11:40 - 11:50h at Van Weelde Zaal

Categories: Basic / translational research, Session (parallel)

Parallel session: Parallel session 12: Basic/translational research

Background

Renal ischemia-reperfusion (I/R) injury represents an unavoidable event in kidney transplantation. Dual Specificity Phosphatase 3 (DUSP3, also called Vaccinia-H1 Related (VHR)) is highly expressed in endothelial cells, as well as in monocytes and macrophages. Since DUSP3 is a positive regulator of the innate immune response, DUSP3 inactivation may attenuate kidney inflammation and damage caused by I/R.

Methods

Ten-week-old C57BL/6 DUSP3 wild-type (WT, n=10) versus systemic knock-out (KO, n=10) mice underwent unilateral left renal ischemia for 30 minutes. Right nephrectomy was simultaneously performed. The left kidney was excised and blood sample was collected from inferior vena cava at 48h post reperfusion. Renal function was assessed upon Blood Urea Nitrogen (BUN) levels. Expressions of inflammatory and immune markers were comparatively quantified at both mRNA (real-time qPCR) and protein (immune-blotting and –staining) levels in ischemic vs. non-ischemic kidneys in DUSP3 WT vs. KO mice.

Results

BUN reached 259±51 vs 78±11mg/dL in DUSP3 WT and KO, respectively (p<0.01). DUSP3 KO ischemic kidneys showed a reduced number of PCNA- (3-fold, p<0.001), CD11b- (3.5-fold, p<0.001) and F4-80-positive cells (1.7-fold, p<0.001) in comparison to WT. The expression levels of CD11b (2.2-fold, p<0.01), HSP70 (2.7-fold, p<0.01) and PCNA (10-fold, p<0.001) was significantly decreased in DUSP3 KO vs. WT in ischemic kidneys. By contrast, a 1.5-fold increase of anti-inflammatory M2 CD206-positive macrophages was observed in DUSP3 KO ischemic kidneys. At mRNA levels, DUSP3 WT vs. KO ischemic kidneys (normalized to WT sham-operated right kidneys) showed the upregulation of 6.5-fold (p<0.05) vs. 10.5-fold (p<0.01) of M2-type macrophage (Arginase), 4.6-fold (p<0.001) vs. 2.2-fold (p<0.05) of CD11b, 4.5-fold (p<0.001) vs. 0.7-fold (p>0.05) of TNF and 111-fold (p<0.001) vs. 4.5-fold (p>0.05) of KIM-1, respectively.

Conclusions

Genetic inactivation of DUSP3 attenuates renal I/R-associated damage and inflammation.