Regional Undergraduate Symposium: Stanniocalcin-1 protects ischemia/reperfusion kidney injury (oral presentation), Advisor: Dr. David Sheikh-Hamad, Baylor College of medicine. Host: Rice University, Department of Biochemistry & Cell Biology, Houston, TX, U.S. Oct 26, 2013

1. Minyi Chen
Dr. David Sheikh-Hamad’s Lab
Stanniocalcin-1 protects
ischemia/reperfusion kidney injury

2. BACKGROUND
 In humans, acute kidney injury is highly prevalent; and the
associated mortality rate remains high (up to 50%).
 Ischemia/reperfusion (I/R) kidney injury, is a major cause of
renal failure in both native and transplanted organs.
 Mouse/rat experimental I/R kidney injury is a model for
human I/R kidney injury. It is associated with phenomenon:
decreased urine output and Glomerular Filtration
Rate(GFR);
inflammation;
tubular cell injury, characterized by vacuolization, cell
necrosis, and hyaline cast formation;
full recovery is complete within 8 days.

3. Mechanism of free radical generation in
ischemia reperfusion injury
Bulkey, G. B. Br. J. cancer, 1987

4. STANNIOCALCIN-1 (STC1) EFFECTS ON:
ROS; ENDOTHELIALAND MACROPHAGE
FUNCTION
 STC1 decreases superoxide generation in macrophages, via
UCP2-depenent pathway (Wang et al., J Leukoc Biol. 2009 86:981-8).
 STC1 inhibits macrophage migration and response to
chemoattractants (Kanellis, J. et al. Am J Physiol Renal Physiol, 2004, 286: F356-F362).
 STC1 blocks Tumour Necrosis Factor(TNF)-α-induced rise in
endothelial monolayer permeability and decreases TNF-α-
induced activation of Jun N-terminal Kinase(JNK), NF- κB, and
superoxide in endothelial cells (Chen, C. et al. Arterioscler Thromb Vasc Biol 2008;
28:906-912).
 STC1 inhibits T-cell and macrophage transmigration across IL-
1β-treated endothelial monolayer (Chakraborty et al., Am J Physiol Renal Physiol.
2007;292:F895-904).

5. WT STC1
Superoxide generation in STC1 Tg and WT
kidney under normal condition without clamping
Labeling with 5 uM MitoSOX Red

6. HYPOTHESIS
 Stanniocalcin-1 protects from I/R kidney injury by
modulating key factors in the pathogenesis of I/R.
These include:
 Decreased Reactive Oxygen Species(ROS) generation;
 Endothelial protection – preservation of normal endothelial
permeability - decreasing trans-endothelial migration of
macromolecules and inflammatory cells (macrophages and
T-cells), into the kidney;
 Direct inhibition of macrophages.

7. Decline in Creatinine clearance (CrCl) after I/R
kidney injury in WT mice; but preservation of
normal CrCl in STC1 Tg mice
Reduce of kidney function indicated by
Glomerular Filtration Rate(GFR);

8. Kidney morphology in WT and STC1 Tg
mice after I/R kidney injury
loss of brush border membrane (arrowheads),
cellular vacuolization (v),
tubular dilatation (dt) with cast formation (c)

9. Preservation of normal vascular permeability in kidneys of
STC1 Tg mice after I/R injury compared to WT mice

10. Increased T-cells and macrophages in kidney of WT
mice after I/R injury; but no change is observed in
kidneys of STC1 Tg mice

11. Increased superoxide and hydroperoxide in WT
kidneys 24h after I/R injury; but not in kidneys of
STC1 Tg mice

12. STC1 protects from I/R kidney injury through suppression of oxidant stress
STC1 Tg mice were
given a single i.p.
injection of saline or
paraquat (12.5
mg/kg). qaraquat is
the generator of
superoxide. I/R
mice were clamped
2h later than
injection, and killed
24h, or 72h. (A)
Superoxide, (B)
hydroperoxide, (C)
CrCl expressed ,
(D) PAS staining for
morphology.

13. WT mice display
Decline in CrCl (Glomerular Filtration Rate) at the 72h to 40% of sham-
treated controls.
Tubular injury (vacuolization, cell necrosis and cast formation).
Increased vascular permeability
Infiltration with macrophages and T-cells starting from day 1 through day 8.
Increased superoxide and hydrogen peroxide generation (c/w increased risk
for injury).
STC1 Tg mice display
No decrease of kidney function.
No increase in superoxide and H2O2 production.
No increase in vascular permeability.
No increase in macrophage and T-cell infiltration after I/R.
Conclusion: Tg overexpression of STC1 protects from I/R kidney
injury; STC1 is a potential therapeutic target for the
prevention/treatment of ischemia-related kidney injury
Summary

14. ACKNOWLEDGEMENTS
David Sheikh-Hamad, MD.
Luping Huang, MD. PhD.
Tatiana Belousova, MD.
Jenny Pan, MD.
Roohi Khan, MD.
Yanlin Wang, MD. PhD.
Luan Truong, MD.
Funding support through the NIH