In vivo cell tracking of canine allogenic mesenchymal stem cells administration via renal arterial catheterization and physiopathological effects on the kidney in two healthy dogs

Stem cell therapy is being special premise for various renal diseases. However, there is limited literature on localization and pathologic and functional effects of allogenic mesenchymal stem cells (MSCs) in healthy dogs. Two healthy dogs were included in this study. Canine MSCs (cMSCs) were cultured from canine bone marrow and incubated with superparamagnetic iron oxide (SPIO) for in vivo cell tracking via MR imaging. The dogs were given the MSC (3 × 10⁶ cells) into a renal artery via femoral artery catheterization. Follow-up serial renal assessments included ultrasonography and MRI, serum chemistry, urine analysis, and renal clearance tests. The dogs were euthanized at days 8 and 35 respectively for histopathologic evaluation of kidney. Strong hypointensity in MRI was detected in the treated renal cortex the day after cMSCs infusion. However they disappeared from MR image by the 8th day. Of the serum chemistry tests, serum hepatic enzymes (ALT, AST) were significantly elevated for one week after cMSCs treatment. Histopathological findings also revealed infiltration of SPIO-containing cells into the parenchyma of kidney. On 35th day, histopathology, glomerular atrophy, tubular necrosis, and mineralization were found in the subcapsular cortex, with fibrosis of the interstitial tissues. In vivo MRI studies of stem cells were useful in determining the sequential location of stem cells in the renal parenchyma of healthy dogs. Allogenic stem cells administered via renal artery caused inflammation, tubular necrosis, mineralization, and fibrosis without functional complications.