BACKGROUND: Septic acute kidney injury affects 40-50% of all septic patients. Molecular differences between septic patients with and without acute kidney injury (AKI) are only poorly understood. Here, we investigated gene expression changes that differentiated the subjects who developed septic AKI from those who did not and coupled this approach with traditional parameters of renal physiology. METHODS: In 15 anesthetized, mechanically ventilated and instrumented pigs, progressive sepsis was induced either by peritonitis or by continuous intravenous infusion of Pseudomonas aeruginosa. Animals received standard intensive care including goal-directed hemodynamic management. Analyses were performed on kidneys from sham operated animals, septic pigs without AKI, and pigs with septic AKI. Before, and at 12, 18 and 22 h of progressive sepsis, systemic and renal hemodynamics, cortex microcirculation and plasma IL-6 and TNF-α were measured. At 22 h whole kidney expression of pre-selected genes was analyzed by quantitative Real Time PCR. RESULTS: Animals with septic AKI had systemic hemodynamic phenotype (normo- or hyperdynamic) comparable with non-AKI subjects, but demonstrated higher plasma levels of cytokines, an increase in renal vascular resistance and early fall in cortical microcirculatory blood flow. The genes whose expression discriminated septic AKI from non-AKI included Toll like receptor 4 (up-regulated 2.7-fold, P = 0.04); Cyclooxygenase-2 (up-regulated 14.6-fold, P = 0.01), Angiotensin II Receptor (up-regulated 8.1-fold, P = 0.01), Caspase 3 (up-regulated 5.1-fold, P = 0.02), Peroxisome Proliferator-Activated Receptor Gamma, Coactivator 1 Alpha (down-regulated 2-fold, P = 0.02). CONCLUSIONS: In this preliminary experimental study, kidney gene expression was profoundly different in animals that developed septic AKI as opposed to septic animals that did not. The biological functions of the genes differentially expressed support a role of inflammatory overstimulation coupled with metabolic and apoptotic molecular responses in early septic AKI. Cyclooxygenase-2 and angiotensin type 2 receptor-dependent downstream mechanisms appear fruitful targets for future mechanistic research.

• Klíčová slova
• Acute kidney injury, Animal models, Gene expression, Sepsis,
• MeSH
• akutní poškození ledvin genetika   mikrobiologie   patofyziologie   MeSH
• cyklooxygenasa 2 genetika   MeSH
• exprese genu * MeSH
• genetická predispozice k nemoci MeSH
• hemodynamika MeSH
• interleukin-6 krev   MeSH
• kaspasa 3 genetika   MeSH
• modely nemocí na zvířatech MeSH
• PPARGC1A genetika   MeSH
• prasata MeSH
• receptory angiotensinu genetika   MeSH
• sepse komplikace   patofyziologie   MeSH
• TNF-alfa krev   MeSH
• toll-like receptor 4 genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cyklooxygenasa 2 MeSH
• interleukin-6 MeSH
• kaspasa 3 MeSH
• PPARGC1A MeSH
• receptory angiotensinu MeSH
• TNF-alfa MeSH
• toll-like receptor 4 MeSH

Novel therapeutic interventions are required to prevent or treat AKI. To expedite progress in this regard, a consensus conference held by the Acute Dialysis Quality Initiative was convened in April of 2014 to develop recommendations for research priorities and future directions. Here, we highlight the concepts related to renal hemodynamics in AKI that are likely to reveal new treatment targets on investigation. Overall, we must better understand the interactions between systemic, total renal, and glomerular hemodynamics, including the role of tubuloglomerular feedback. Furthermore, the net consequences of therapeutic maneuvers aimed at restoring glomerular filtration need to be examined in relation to the nature, magnitude, and duration of the insult. Additionally, microvascular blood flow heterogeneity in AKI is now recognized as a common occurrence; timely interventions to preserve the renal microcirculatory flow may interrupt the downward spiral of injury toward progressive kidney failure and should, therefore, be investigated. Finally, development of techniques that permit an integrative physiologic approach, including direct visualization of renal microvasculature and measurement of oxygen kinetics and mitochondrial function in intact tissue in all nephron segments, may provide new insights into how the kidney responds to various injurious stimuli and allow evaluation of new therapeutic strategies.

• Klíčová slova
• acute renal failure, clinical nephrology, hemodynamics and vascular, regulation,
• MeSH
• akutní poškození ledvin patofyziologie   terapie   MeSH
• biomedicínský výzkum MeSH
• hemodynamika * MeSH
• lidé MeSH
• renální oběh * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH