Potential renoprotective effects of subcapsular inoculation of mesenchymal stem cells derived from adipose tissue in an experimental model of chronic kidney disease

• Grant number: 17/26216-0
• Support type: Regular Research Grants
• Duration: June 01, 2018 - February 28, 2021
• Field of knowledge: Health Sciences - Medicine
• Principal researcher: Camilla Fanelli
• Grantee: Camilla Fanelli
• Home Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Assoc. researchers: Irene de Lourdes Noronha ; Samirah Abreu Gomes

Abstract

Chronic kidney disease (CKD) is a progressive, debilitating condition of high lethality, which prevalence have been increasing considerably in recent decades. Regardless of the etiology of CKD, the exacerbated activation of the renin-angiotensin-aldosterone system (RAAS), as well as the establishment of local renal inflammation, with engagement of both innate and adaptive mechanisms, extracellular matrix accumulation and renal fibrosis, contribute significantly to its establishment and evolution, leading to the need for renal replacement therapy. Currently, the therapeutic arsenal used to control CKD is limited to RAAS inhibitors, diuretics and immunosuppressive drugs. These latter being frequently related to important side effects, which limit its therapeutic employment for prolonged periods of time. Recent literature have demonstrated that the application of mesenchymal stem cells (CTm) in renal tissue of animals submitted to experimental CKD models can detain local renal inflammation and delay renal fibrogenesis, specially through its paracrine effects, which involves intercellular signaling and anti-inflammatory interleukins production. Based on the foregoing, the aim of the present study is to evaluate the renoprotective effects of subcapsular injection of CTm derived from adipose tissue (CTmTA) in Wistar rats submitted to CKD model induced by surgical 5/6 renal ablation (Nx). Our specific goals include: Verify if the subcapsular application of CTmTA performed in time zero, concomitantly with renal ablation, prevents CKD development in this model; Analyze the therapeutic effects of late application of CTmTA, performed 30 days after renal ablation, when CKD is already well established, thus mimicking the conditions observed in clinical practice more closely; Compare the renoprotective effects of the experimental treatment with CTmTA in the Nx model with the renoprotection obtained in the same model with the administration of Losartan, a RAAS inhibitor commonly used in clinical treatment of CKD; Verify if the subcapsular application of CTmTA associated to the therapy with Losartan promotes a greater renoprotection compared to the respective monotherapy. For this purpose, adult male Wistar rats will underwent surgical ligation of 2 of the 3 branches of the renal artery of the left kidney, promoting an infarction of 2/3 of left kidney mass. After ablation, the right kidney will be removed, thus achieving a reduction of 5/6 in the total renal mass. CTmTA used in this study will be isolated from the gonadal subcutaneous adipose tissue of healthy male adult Wistar rats. Once isolated, cells will be plated and cultured until the 4th cell pass, when cell populations will be characterized by flow cytometry, and submitted to plasticity assays tests. CTmTA will be inoculated in the kidneys of Nx animals at two different times, depending on the experimental group: Immediately after renal ablation, when the animals are already anesthetized and the kidneys are exposed in the surgical field; or, 30 days after the Nx surgery, when animals will be anesthetized again and submitted to subcapsular injection of 10 ¼L of solution containing; 2x106 CTmTA resuspended in sterile PBS. All rats will be kept under adequate conditions of temperature, humidity and lighting and their weight will be monitored weekly. Groups treated with Losartan (50 mg/kg/day) will receive this drug daily, diluted in drinking water. Conversely, the other groups will have free access to pure tap water. At the end of the study period (30 or 60 days after renal ablation), animals will have their systolic blood pressure measured through a tail-cuff method. Twenty-four-hour urine samples will be collected for albuminuria analysis and euthanasia will be performed to collect blood and tissues for biochemical, histological, immunohistochemical and molecular analyses. (AU)