Distinct Temporal Modulation of Mesenchymal Stem Cells and Empagliflozin on Renal c-Kit Cells in Diabetic Kidney...

Diabetic kidney disease (DKD) remains a leading cause of chronic kidney disease worldwide despite current standard therapies. c-Kit⁺ renal progenitor cells have been implicated in kidney repair and regeneration. We investigated whether mesenchymal stem cells (MSCs) and the sodium-glucose cotransporter-2 inhibitor empagliflozin are associated with differential modulation of intrarenal c-Kit⁺ cell expression in a preclinical model of DKD using BTBR^ob/ob mice.

These BTBR^ob/ob mice were allocated into three groups: untreated DKD, MSC-treated DKD, and empagliflozin-treated DKD, and were compared with BTBR wild-type (WT) controls. BTBR^ob/ob mice received empagliflozin formulated inchow ad libitum at 25 mg/kg (Jardiance®, Boehringer Ingelheim, Ingelheim am Rhein, RP, Germany) starting at 4-5 weeks of age. MSCs (1 × 10⁶ cells per dose) were administered intraperitoneally at 8 and 10 weeks of age. Animals were evaluated at 10, 14-15, and 18-20 weeks. Renal c-Kit gene expression was quantified by quantitative real-time PCR (qPCR), and protein expression was assessed by immunohistochemistry in the cortex, medulla, and glomeruli. Statistical analyses included mixed-effects models and two-way analysis of variance (ANOVA).

c-Kit expression was significantly influenced by time and treatment in both cortex and medulla. In the renal cortex, MSC therapy was associated with a transient increase in c-Kit gene expression at 14-15 weeks, followed by a reduction at 18-20 weeks. Empagliflozin predominantly modulated cortical c-Kit expression at later time points. Immunohistochemistry demonstrated higher cortical c-Kit protein expression in MSC-treated animals compared with untreated DKD mice. In the medulla, MSC-treated mice exhibited increased c-Kit expression at 14-15 weeks, which declined at 18-20 weeks. Empagliflozin had a modest effect on c-Kit expression and was associated with infrequent glomerular immunoreactivity at 14-15 weeks.

MSC therapy and empagliflozin are associated with distinct temporal patterns of c-Kit expression in DKD. MSC treatment showed early modulation of c-Kit expression, whereas empagliflozin exhibited more delayed effects. These findings suggest that c-Kit⁺ cells are dynamically regulated during DKD progression. Given the absence of functional and mechanistic analyses, these results should be considered hypothesis-generating and warrant further investigation.