Hypoxic preconditioning for the improvement of the regenerative capacity of adipose-derived mesenchymal stem cells and its application in chronic kidney disease due to hypertensive nephropathy

PROJECT SUMMARY/ABSTRACT Hypertensive Nephropathy (HN) is the second leading cause of chronic kidney disease (CKD) resistant to effective intervention to prevent progression. However, recent advances in regenerative medicine with the use of adipose tissue-derived mesenchymal stromal/stem cell (AD-MSC) transplantation offer hope for these patients. The MSCs have anti-fibrotic, anti-inflammatory, and pro-angiogenic paracrine activities that improve regeneration in some kidney injury models. However, exposure to patient-specific factors, such as aging and the uremic milieu of CKD in HN, may exert epigenetic and transcriptional modulation of MSC, potentially modifying their phenotype to one noxious to neighboring cells. Hence, increased cellular damage in HN may substantially compromise MSC function and become a barrier to successful autologous MSC transplantation. Our central hypothesis underlying this proposal is that MSCs obtained from patients with HN show impaired functionality and angiogenesis, which can be modified with hypoxic preconditioning (HPC). This hypothesis will be addressed both in vitro and in vivo in three specific aims: 1) we will compare functionality of MSCs from patients with HN (eGFR 15-60 mL/min/1.73m2) to MSC from age- and sex-matched patients with hypertension and healthy controls; 2) to determine the reversibility of HN-MSC dysfunction, we will subject cells from these cohorts to HPC in vitro and assess MSC function thereafter; and 3) to examine the effect of MSC function in vivo, we will conduct an experimental study in a porcine renovascular hypertension model that recapitulates the pathophysiology of HN, six-weeks after induction of renal artery stenosis. These pigs, as well as normal age-matched pigs, will be treated with HPC-MSC, untreated-MSC, or vehicle. To assess the impact of HPC on MSC potency, renal hemodynamics, function, and oxygenation will be studied after four-weeks, using sophisticated in vivo CT and MR imaging techniques, and renal injury and vascularity studied ex vivo. The significance of the proposed studies is high, since developing a safe and effective therapy to delay HN progression could reduce morbidity associated with dialysis, offer a better treatment option to a population often deferred for kidney transplantation, and produce extensive cost savings. These novel studies will advance the knowledge of the effects of HPC on MSC and their deleterious microenvironment, aid in developing a completely novel therapeutic strategy to delay the progression of HN supporting the NIDDK mission. The proposed project addresses how characterize and improve the functional properties of MSC in HN to allow these patients to benefit from future enrollment in clinical trials using stem cell transplantation. The exceptional resources and institutional support at Mayo Clinic, outstanding multi-disciplinary mentorship team, and proposed career development activities will allow the candidate to achieve her long-term goal of becoming an independent investigator and a nationally recognized leader in regenerative medicine in nephrology.