Mers utilized in the genotype.Wang Chun-Hong (School of Public Health, Wuhan University) and Dr. Xie Yan (School of Basic Medical Sciences, Wuhan University) for their guidance in statistical analysis.(DOC)Author ContributionsConceived and designed the experiments: SWL XZ SML. Performed the experiments: SWL KL PM. Analyzed the data: SWL SYL. Contributed reagents/materials/analysis tools: ZLZ YDZ. Wrote the paper: SWL XZ SML.AcknowledgmentsWe thank all of 18325633 the participants of the study. Thanks to Wuhan Asia Heart Hospital for assistance with sample collection. We also thank Professor
Partial nephrectomy (PN) exhibits similar efficacy in treating renal cancers as radical nephrectomy (RN) and is superior to RN in preserving renal function and prevention of chronic kidney disease [1?]. However, renal hilar clamping causes warm ischemia (WI), with the potential for renal ischemia/reperfusion injury (IRI) [7,8]. It has been recently demonstrated that inhibitor endothelial progenitor cells (EPCs) contribute to the restoration of renal function after IRI. EPC transplantation was associated with improvement in renal function following IRI, and has been explained by enhanced repair of renal microvasculature, tubule epithelial cells and synthesis of high-levels of pro-angiogenic cytokines, which promoted proliferation of both endothelial and epithelial cells [9]. Moreover, EPC incompetence may be an important mechanism of accelerated vascular injury and eventually lead to chronic renal failure [10]. However, the number ofEPCs in the circulation and bone marrow of adults is insufficient to repair IRI in affected organs [11] and the number of EPCs that can be transplanted into the circulation is limited. Hence, the ability to sufficiently increase the number of EPCs has become an issue of concern. Studies have confirmed that ischemic preconditioning (IPC) is an Epigenetic Reader Domain innate phenomenon in which brief exposure to sublethal ischemia induces a tolerance to injurious effects of prolonged ischemia in various organs [12] and is also an effective method to increase the number of EPCs [13,14]. IPC has two distinct phases: The early phase of IPC is established within minutes and may last for several hours. Conversely, the late phase of protection requires hours to days to develop and becomes apparent after 24 h to several days [13,15]. However, the interval between pre-ischemic and ischemic injury is too long for clinical application. Hence, we focused on the early phase of IPC in this study.Ischemic Preconditioning and RenoprotectionFigure 1. Time-dependent changes in renal function in the treatment groups. A. BUN (mmol/L); B. SCr (mmol/L). Each histogram represents mean 6 SEM. *Significant difference vs. Sham group (P,0.05); #significant difference vs. IPC group (P,0.05). doi:10.1371/journal.pone.0055389.gLi et al. [14] investigated whether the early phase of IPC could produce rapid increases in the number of circulating EPCs in 
the myocardium, with the goal of directly preserving the microcirculation in the ischemic myocardium by incorporation of EPCs into vascular structures. They also assessed whether EPCs could act as vascular endothelial growth factor (VEGF) donors in ischemic myocardium. Therefore, it appears logical to determine whether the early phase of IPC could protect the remaining renal tissue following PN through the mechanism described above. Thus, the present study was designed to investigate the effects of IPC on renal IRI induced by PN, as well as the possi.Mers utilized in the genotype.Wang Chun-Hong (School of Public Health, Wuhan University) and Dr. Xie Yan (School of Basic Medical Sciences, Wuhan University) for their guidance in statistical analysis.(DOC)Author ContributionsConceived and designed the experiments: SWL XZ SML. Performed the experiments: SWL KL PM. Analyzed the data: SWL SYL. Contributed reagents/materials/analysis tools: ZLZ YDZ. Wrote the paper: SWL XZ SML.AcknowledgmentsWe thank all of 18325633 the participants of the study. Thanks to Wuhan Asia Heart Hospital for assistance with sample collection. We also thank Professor
Partial nephrectomy (PN) exhibits similar efficacy in treating renal cancers as radical nephrectomy (RN) and is superior to RN in preserving renal function and prevention of chronic kidney disease [1?]. However, renal hilar clamping causes warm ischemia (WI), with the potential for renal ischemia/reperfusion injury (IRI) [7,8]. It has been recently demonstrated that endothelial progenitor cells (EPCs) contribute to the restoration of renal function after IRI. EPC transplantation was associated with improvement in renal function following IRI, and has been explained by enhanced repair of renal microvasculature, tubule epithelial cells and synthesis of high-levels of pro-angiogenic cytokines, which promoted proliferation of both endothelial and epithelial cells [9]. Moreover, EPC incompetence may be an important mechanism of accelerated vascular injury and eventually lead to chronic renal failure [10]. However, the number ofEPCs in the circulation and bone marrow of adults is insufficient to repair IRI in affected organs [11] and the number of EPCs that can be transplanted into the circulation is limited. Hence, the ability to sufficiently increase the 
number of EPCs has become an issue of concern. Studies have confirmed that ischemic preconditioning (IPC) is an innate phenomenon in which brief exposure to sublethal ischemia induces a tolerance to injurious effects of prolonged ischemia in various organs [12] and is also an effective method to increase the number of EPCs [13,14]. IPC has two distinct phases: The early phase of IPC is established within minutes and may last for several hours. Conversely, the late phase of protection requires hours to days to develop and becomes apparent after 24 h to several days [13,15]. However, the interval between pre-ischemic and ischemic injury is too long for clinical application. Hence, we focused on the early phase of IPC in this study.Ischemic Preconditioning and RenoprotectionFigure 1. Time-dependent changes in renal function in the treatment groups. A. BUN (mmol/L); B. SCr (mmol/L). Each histogram represents mean 6 SEM. *Significant difference vs. Sham group (P,0.05); #significant difference vs. IPC group (P,0.05). doi:10.1371/journal.pone.0055389.gLi et al. [14] investigated whether the early phase of IPC could produce rapid increases in the number of circulating EPCs in the myocardium, with the goal of directly preserving the microcirculation in the ischemic myocardium by incorporation of EPCs into vascular structures. They also assessed whether EPCs could act as vascular endothelial growth factor (VEGF) donors in ischemic myocardium. Therefore, it appears logical to determine whether the early phase of IPC could protect the remaining renal tissue following PN through the mechanism described above. Thus, the present study was designed to investigate the effects of IPC on renal IRI induced by PN, as well as the possi.
