Abstract: FR-PO116
Role of Intestinal Alkaline Phosphatase (IAP) in Lipopolysaccharide (LPS)-Induced Septic AKI
Session Information
- AKI: Mechanisms - Inflammation/Sepsis/Remote Injury
November 08, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 103 AKI: Mechanisms
Authors
- Ghosh, Siddhartha S., VCU Medical Center, Richmond, Virginia, United States
- Mullaly, Austin J., Virginia Commonwealth University, Richmond, Virginia, United States
- Denecke, Morgan H., Virginia Commonwealth University, Richmond, Virginia, United States
- Lal, Vatsal, Virginia Commonwealth University, Richmond, Virginia, United States
- Ghosh, Shobha, Virginia Commonwealth University, Richmond, Virginia, United States
- Gehr, Todd W., Virginia Commonwealth University, Richmond, Virginia, United States
Background
LPS plays a significant role in septic AKI. IAP is known to dephosphorylate LPS and render it inactive. LPS has also been suggested to play a role in leaky gut associated with septicemia. We hypothesized that overexpressing IAP will be beneficial for septic AKI. To test this hypothesis, we developed IAP transgenic mice (IAPTg). This was compared with IAP knock out (IAPKO) and wild type mice of the same background.
Methods
Septic AKI was induced by IP injection of 10 mg/kg LPS. Mice used were IAPTg which had human chimeric IAP under the control of villin promoter making them intestine and kidney specific. This chimeric human IAP (IAPTg) contains domains from human placental alkaline phosphatase which has a high turnover number and selectivity for LPS. The second group was IAP knockout (IAPKO). Both groups received LPS and compared with LPS-treated wild type (LPS-WT) and saline-treated wild type mice (Control). FITC-Dextran (FD) was given by gavage 2 hours before sacrifice to measure intestinal permeability. Blood and kidneys were harvested for biochemical and immunoblot analysis
Results
The table clearly shows the IAPTg mice have significantly improved renal function compared to LPS-WT and IAPKO mice.
Creatinine and BUN of IAPKO mice were not significantly different from LPS-WT; serum FD levels were highest in IAPKO>LPS>IAPTg>Control. The kidney inflammasome markers measured by western blot of IAPKO mice were significantly higher than in the LPS-WT, IAPTg, and control groups. High mobility group box protein (HMGB-1), a late phase mediator of LPS, and gasdermin D, a marker for pyroptosis, were significantly high in IAPKO followed by LPS.
Conclusion
Increased serum FD in IAPKO and LPS-WT group suggests that endotoxemia can breach intestinal barrier function resulting in the leakage of intestinal toxins from the gut and aggravating inflammation. IAP abates leaky gut, inflammation, and cell death (pyroptosis) and improves renal function by inactivating LPS.
| FD absorption ug/ml | BUN mg/dl | Creatinine mg/dl | NFkB arb units | Caspase1 arb units | IL1-β arb units | HMGB-1 arb Units | Gasdermin arb units | |
| Control | 4.3±2 b,c,d | 58.2±7 b,c,d | 0.47±.2 b,c,d | 0.4±.06 b,c,d | 0.4±.05 b,c,d | 0.13±0.02 b,c,d | 0.09±.03 b,c,d | 0.1±.02 b,c,d |
| LPS-WT | 12±1 a,c | 173±3 a,c | 2.2±.2 a,c | 1.3±.4 a,c,d | 0.9±.2 a,c,d | 0.5±.1 a,c,d | 0.8±.1 a,c,d | 0.5±.1 a,c,d. |
| IAPTg+LPS | 5.8±0.5 a,b,d | 101±4 a,b,d | 1.1±.3 a,b,d | 0.8±.1 a,b,d | 0.6±.08 a,b,d | 0.3±.04 a,b,d | 0.22±.01 a,b,d | 0.7±.1 a,b,d |
| IAPKO+LPS | 19.4±3 a,bc | 174±1.3a,c | 1.8±.5 a,c | 2±.6a,b,c | 1.3±.2 a,b,c | 0.8±.08 a,b,c | 1.3±0.14 a,b,c | 1±0.3 a,b,c |
a<0.05 than control; b<0.05 than LPS; c<0.05 than IAPTg+LPS; d<0.05 than IAPKO+LPS
Funding
- Private Foundation Support