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Pawel Jonkisz, Katarzyna Michlik, Liliana Kiczak*, Urszula Paslawska, Izabela
Sambor *, Agnieszka Kurosad ©
Department of Internal Diseases with Clinic for Horses, Dogs and Cats, Faculty of Veterinary Medicine, University of Environmental and Life Science in Wroclaw,
Poland
*Department of Biochemistry, Faculty of Veterinary Medicine, University of Environmental and Life Science in Wroclaw, Poland
HIF-1A RELATIVE EXPRESSION IN RENAL TISSUES OF DOGS WITH CHRONIC RENAL AND HEART INSUFFICIENCY
Abstract
Hypoxia Inducible Factor 1 (HIF-1) is an important transcription factor that under hypoxic condition activates the transcription of genes encoding erythropoietin, glucose transporters, glycolytic enzymes, vascular endothelial growth factor and other genes whose protein products increase O2 delivery or facilitate metabolic adaptation to hypoxia. Our research was concerned on evaluation of HIF-1a relative expression in renal tissues of dogs with chronic renal failure (5 dogs), heart failure (9 dogs) and in healthy dogs (7 dogs). HIP-1a level was measured by: RTime-PCR, Western blots methods, agar-gel electrophoresis and immunofluorescence. Level of HIF-1a relative expression in renal tissues of dogs with chronic renal and heart failure increased significantly due to ischemia of given regions.
Key words: HIF, renal insufficiency, heart failure, dogs
Introduction
Hypoxia Inducible Factor 1 (HIF-1) is a basic-helix-loop helix transcription factor that plays essential roles in mammalian development and physiology. HIF-1 is composed of HIP-1a and HIF-1P subunits. The expression and activity of HIF-1a subunit is regulated by cellular 02 concentration. Under hypoxic condition HIF-1 activates the transcription of genes encoding erythropoietin, glucose transporters, glycolytic enzymes, vascular endothelial growth factor and other genes whose protein products increase O2 delivery or facilitate metabolic adaptation to hypoxia. HIF-1 is essential for embryonic vascularization and survival, neovasularization in ischemic myocardium, hypoxia-induced pulmonary vascular remodeling and tumor vascularization. Recent date indicate that HIF-1 plays major roles in the prevention of myocardial and cerebral ischemia and in the pathogenesis of pulmonary hypertension and cancer. And because the chronic renal insufficiency is related to chronic hypoxia caused by chronic ischemia, HIF-1 concentration may have a very important role in early diagnosis of renal insufficiency.
© Pawel Jonkisz, Katarzyna Michlik, Liliana Kiczak*, Urszula Paslawska, Izabela Sambor, Agnieszka Kurosad, 2009
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Task, the aim of the article
The aim of our research was to evaluate the relative expression of HIF-1a in renal tissues of healthy dogs and dogs in the end stage of chronic renal and heart insufficiency.
Material and methods
Renal samples were taken post-mortem from dogs of various breeds, sex (17 males and 4 females) and age (from 4 to 16 years old). 14 samples were taken from sick animals and 7 from euthanized dogs because of old age. Sick dogs were divided into 2 subgroups: 5 dogs in the end stage of renal insufficiency and 9 dogs in the end stage of heart failure.
Taken samples were tested by: RTime-PCR, Western blots methods, agar-gel electrophoresis and immunofluorescence.
Results of researches
The level of HIF-1a in dogs in the end stage of renal and heart insufficiency was doubled compare to group of healthy dogs. The concentration of relative expression of HIF-1a in kidneys of dogs with renal and heart failure was three times higher than in healthy animals.
On that basis, we conclude that the level of HIF-1a relative expression increases significantly in renal tissues during ischemia caused by chronic renal and heart insufficiency. And the level of HIF-1a relative expression is higher in renal tissues in dogs with heart failure compare to dogs with renal insufficiency.
The end stage of renal insufficiency is accompanied by chronic hypoxia caused by ischemia. Naganaku suggested that hypoxia was followed by structural damage of micro-vascularization of given region. So we may suggest that hypoxia plays a very significant role in early stage of renal failure. So the diagnosis based on HIF can be useful in evaluation of renal damage in early stage of renal insufficiency. Chronic renal insufficiency is often observed in patients with chronic heart failure. And dysfunction of kidneys and heart is usually called cardio-renal syndrome. Failure of one of the observed organs accelerates the insufficiency of other. Findings from literature suggest that there is a close relationships and interaction between heart and renal failure that results in progressive functional dysfunction of that organs. Development of renal failure can caused left-heart insufficiency and progresses kidney dysfunction. That is called "vicious circle" and may explain such high level of HIF-1a in renal tissues in dogs with chronic heart failure.
Conclusion
HIF-1 plays a significant role in heart and kidneys protection against to heart and renal failures (caused by ischemia) and cerebral ischemia. Under hypoxic condition HIF-1 activates the transcription of VEGF gene encoding vascular endothelial growth factor and by angiogenesis promotes vascularization and decreases the adverse effects of hypoxia. Gene- HIF-1- therapy may improve the angiogenesis stimulations in ischemic tissues. So HIF-1 is discussed as a significant modulator in cellular prevention against to hypoxia.
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Fig. 1. HIF -1 protein in dogs" renal tissues (Western blots methods):
1 2 3 4 5
1. The mass mark
2. HIF-1 protein concentration in dog with heart failure: 10 pg
3. HIF-1 protein concentration in dog with heart failure: 2 pg
4. HIF-1 protein concentration in healthy dog: 10 pg
5. HIF-1 protein concentration in healthy dog: 2 pg
Fig.2. Results of RT-PCR. The level of relative expression of HIF-1a.
50,0 40,00 30,00 20,00 10,00 0,00
Healthy dogs Renal Failure
Heart Failure HIF-1
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Reference
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2. Nangaku M. ; Chronic hypoxia and tubulointerstitial injury: A final common pathway to end-stage renal failure; Division of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo, Japan.
3. Semenza G.L; Expression of hypoxia-inducible factorl: mechanisms and consequences; Biochemical Pharmacology, Vol. 59,pp. 47-53, 2000.
4. Wang G.L., Semenza G.L.; General involvement of hypoxia-inducible factor 1 in transcriptional response to hypoxia; Proc. Natl.Acad.Sci.USA Vol.90,pp. 4304-4308, May 1993, Genetics;
5. Semenza G.L.; HIF-1: mediator of physiological and pathophysiological responses to hypoxia; J.Appl Physiol, 88: 1474-1480, 2000;
6. Zolty R., Hynes P.J. and Vittorio T.J.; Severe left ventricular systolic dysfunction may reverse with renal transplantation: uremic cardiomyopathy and cardiorenal syndrome; American Journal of Transplantation 2008, 8 : 2219-2224, Wiley Periodicals Inc.
7. Manotham K.M., Tanaka T., Ohse T, Kojami I, Miyata T, Inagi R., Tanaka H, Sassa R., Fujita T, Nangaku M; A biologic role of HIF-1 in the renal medulla; Kidney International, Vol. 67( 2005), pp. 1428-1439;
8. Alexis Biochemicals; Hypoxia & HIF-1 Product Line Newsletter October 2007
Summary
Jonkisz P., Michlik K., Kiczak L.*, Paslawska U., Sambor I.*, Kurosad A.
Department of Internal Diseases with Clinic for Horses, Dogs and Cats, Faculty of Veterinary Medicine, University of Environmental and Life Science in Wroclaw,
Poland
*Department of Biochemistry, Faculty of Veterinary Medicine, University of Environmental and Life Science in Wroclaw, Poland HIF-1A RELATIVE EXPRESSION IN RENAL TISSUES OF DOGS WITH CHRONIC RENAL AND HEART INSUFFICIENCY
That articles describes probability of using the HIF-1a relative expression in renal tissues of dogs with chronic renal and heart insufficiency. Study was performed on healthy dogs and dogs with renal and heart failure. Sample of renal tissues were taken in post-mortem examination and measure by various methods: RTime-PCR, Western blots methods, agar-gel electrophoresis and immunofluorescence. Our research shown that the level of HIF relative expression increased significantly in kidneys tissues in dogs with chronic renal failure (38,97) and heart failure (46,17) compare to healthy dogs.
Cmammx nadiumna do peda^ii 25.09.2009
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