Location
Philadelphia, PA
Start Date
1-5-2024 1:00 PM
End Date
1-5-2024 4:00 PM
Description
Introduction
Ischemia-reperfusion (I/R) injury is marked by increased reactive oxygen species (ROS) during reperfusion, causing cellular injury. Uncoupled endothelial nitric oxide synthase (eNOS) is a major source of ROS in myocardial I/R, hindlimb I/R, and kidney extracorporeal shock wave lithotripsy. During reperfusion, activation of protein kinase C epsilon (PKCε) enhances ROS via uncoupled eNOS due to an increased dihydrobiopterin/tetrahydrobiopterin ratio. Inhibiting uncoupled eNOS using myristic acid conjugated-PKCε peptide inhibitor (N-Myr-EAVSLKPT [Myr-PKCε-]) attenuates ROS. This study examined the effects of Myr-PKCε- in kidney I/R. We hypothesized that Myr-PKCε- will exert renal-protective effects by attenuating PKCε translocation in kidney I/R compared to scrambled control peptide (N-Myr-LSETKPAV [Myr-PKCε-scram]).
Methods
Renal pedicles of anesthetized male C57BL/6J mice (25–30g) were clamped bilaterally for 19 mins. One minute before unclamping, 1.6 mg/kg Myr-PKCε- (n=6) or Myr-PKCε-scram (n=7) was administered i.v. Glomerular filtration rate (GFR; µl/min) and serum creatinine (Cr; mg/dL) were measured at baseline, 24hrs, 72hrs, and 96hrs post-injury. GFR was determined with localization fluorescein-isothiocyanate (FITC)-Sinistrin renal clearance. Immunohistochemistry (IHC) staining of samples was used to detect the cell membrane of PKCε using AperioImageScope. Data was analyzed using Student’s t-test.
Results
Myr-PKCε- significantly improved GFR and reduced Cr throughout reperfusion compared to Myr-PKCε-scram (both, p
Conclusion
Results suggest Myr-PKCε- improved renal function following kidney I/R and mitigated PKCε localization in tubular epithelium compared to Myr-PKCε-scram. Results also suggest that Myr-PKCε decreases PKCε localization in vascular and epithelial renal tissue, leading to less ROS and injury.
Embargo Period
12-13-2024
Lessons learned from protein kinase C epsilon peptide mitigation of ischemia/reperfusion injury for post-transplant acute kidney injury (AKI) and the key function of uncoupled endothelial nitric oxide synthase in this process
Philadelphia, PA
Introduction
Ischemia-reperfusion (I/R) injury is marked by increased reactive oxygen species (ROS) during reperfusion, causing cellular injury. Uncoupled endothelial nitric oxide synthase (eNOS) is a major source of ROS in myocardial I/R, hindlimb I/R, and kidney extracorporeal shock wave lithotripsy. During reperfusion, activation of protein kinase C epsilon (PKCε) enhances ROS via uncoupled eNOS due to an increased dihydrobiopterin/tetrahydrobiopterin ratio. Inhibiting uncoupled eNOS using myristic acid conjugated-PKCε peptide inhibitor (N-Myr-EAVSLKPT [Myr-PKCε-]) attenuates ROS. This study examined the effects of Myr-PKCε- in kidney I/R. We hypothesized that Myr-PKCε- will exert renal-protective effects by attenuating PKCε translocation in kidney I/R compared to scrambled control peptide (N-Myr-LSETKPAV [Myr-PKCε-scram]).
Methods
Renal pedicles of anesthetized male C57BL/6J mice (25–30g) were clamped bilaterally for 19 mins. One minute before unclamping, 1.6 mg/kg Myr-PKCε- (n=6) or Myr-PKCε-scram (n=7) was administered i.v. Glomerular filtration rate (GFR; µl/min) and serum creatinine (Cr; mg/dL) were measured at baseline, 24hrs, 72hrs, and 96hrs post-injury. GFR was determined with localization fluorescein-isothiocyanate (FITC)-Sinistrin renal clearance. Immunohistochemistry (IHC) staining of samples was used to detect the cell membrane of PKCε using AperioImageScope. Data was analyzed using Student’s t-test.
Results
Myr-PKCε- significantly improved GFR and reduced Cr throughout reperfusion compared to Myr-PKCε-scram (both, p
Conclusion
Results suggest Myr-PKCε- improved renal function following kidney I/R and mitigated PKCε localization in tubular epithelium compared to Myr-PKCε-scram. Results also suggest that Myr-PKCε decreases PKCε localization in vascular and epithelial renal tissue, leading to less ROS and injury.