Development of experimental nephrotoxicity model in vivo and assessment of its’ applicability for stem cell research

Egle Svitojute1, Romaldas Maciulaitis1,2, Judita Zymantiene1, Justinas Maciulaitis1. 1Lithuanian University of Health Sciences, Kaunas, Lithuania, 2Hospital of Lithuanian University of Health Sciences, Kaunas Clinics, Kaunas, Lithuania

Kidney is one of the main target organs of xenobiotic-induced toxicity. However, minor effects on renal function are difficult to detect (1). Acute kidney injury (AKI) is a serious and frequent condition. Though prognosis of patients who survived AKI is quite prosperous, mortality rates are high reaching 60% (2, 3). Then AKI is severe and continuous, it can develop to chronic kidney disease (CKD). Stem cell therapy is one of the most promising methods for prevention of CKD and treatment of AKI. Preclinical studies are essential for development of stem cell therapies. Nephrotoxicity models need to be created, so that comprehensive stem cell research could be developed.

The main objective of this study was to develop experimental nephrotoxicity model in animals and to assess its’ applicability for stem cell research in vivo.

Adult male Wistar rats were chosen for the model, toxicant - Gentamicin (GM). 3 groups were constituted: control group (i.p. injection of saline 1.5 ml for 14 days), therapeutic group (i.p. injection of GM 5mg/kg/d for 14 days), AKI group (i.p. injection of GM 80mg/kg/d for 7 days). We evaluated physiological parameters (body weight, consumed amount of water and food per day, diuresis), behavioural parameters, biochemical urine and blood parameters (of potassium, sodium, phosphate and creatinine), fractional excretion parameters (of potassium, sodium and phosphate), glomerular filtration rate and histological kidney parameters. All parameters were compared between groups.

GM administration in a very high dose (80 mg/kg/d i. p. for 7 consecutive days) caused functional and morphological renal changes and induced AKI, which was marked by statistically significant changes of physiological, behavioural, biochemical, fractional excretion, glomerular filtration rate and histological parameters, comparing with the same parameters of control and therapeutic groups (p<0,05). Nephrotoxicity model was applied for the pilot study with stem cells. Isolated and cultured muscle derived stem cell i. p. injection (dose – 150.000–200.000 cell/injection) was administrated to acute kidney injury group rats 24 hours after last GM injection. In the end of the pilot study, stem cell injection demonstrated the influence on better kidney regeneration, comparing with the acute kidney injury group, without muscle derived stem cell therapy.

GM intraperitoneal administration in a very high dose (80 mg/kg/d) for 7 consequent days caused AKI to laboratory animals, which was marked by physiological, behavioural, biochemical, fractional excretion, glomerular filtration and histological parameters. The results of the pilot study demonstrate the applicability of the established nephrotoxicity model for preclinical stem cell research in vivo.

(1) Sieber M et al. Comparative analysis of novel noninvasive renal biomarkers and metabonomic changes in a rat model of gentamicin nephrotoxicity. Toxicol Sci. 2009 Jun;109(2):336-49.

(2) Hoste EA, Schurgers M. Epidemiology of acute kidney injury: how big is the problem? Crit Care Med. 2008;36(4):146-51.

(3) Uchino S et al. Acute renal failure in critically ill patients: a multinational, multicenter study. JAMA. 2005;294(7):813-8.