Impact of Syndecan-2-Selected Mesenchymal Stromal Cells on the Early Onset of Diabetic Cardiomyopathy in Diabetic db/db Mice

Kathleen Pappritz; Fengquan Dong; Kapka Miteva; Arpad Kovacs; Muhammad El-Shafeey; Bahtiyar Kerim; Lisa O'Flynn; Stephen Joseph Elliman; Timothy O'Brien; Nazha Hamdani; Carsten Tschöpe; Sophie Van Linthout

doi:10.3389/fcvm.2021.632728

Impact of Syndecan-2-Selected Mesenchymal Stromal Cells on the Early Onset of Diabetic Cardiomyopathy in Diabetic db/db Mice

Front Cardiovasc Med. 2021 May 21:8:632728. doi: 10.3389/fcvm.2021.632728. eCollection 2021.

Authors

Kathleen Pappritz^{1

2

3}, Fengquan Dong², Kapka Miteva^{2

4}, Arpad Kovacs⁵, Muhammad El-Shafeey^{1

2

3

6}, Bahtiyar Kerim², Lisa O'Flynn⁷, Stephen Joseph Elliman⁷, Timothy O'Brien⁸, Nazha Hamdani^{5

9

10}, Carsten Tschöpe^{1

2

3

11}, Sophie Van Linthout^{1

2

3}

Affiliations

¹ Berlin Institute of Health at Charité - Universitätmedizin Berlin, BIH Center for Regenerative Therapies (BCRT), Berlin, Germany.
² Berlin-Brandenburg Center for Regenerative Therapies, Charité, Universitätsmedizin Berlin, Berlin, Germany.
³ German Center for Cardiovascular Research (DZHK), Partner site Berlin, Berlin, Germany.
⁴ Division of Cardiology, Foundation for Medical Research, Department of Medicine Specialized Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
⁵ Institute of Physiology, Ruhr University Bochum, Bochum, Germany.
⁶ Medical Biotechnology Research Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), City of Scientific Research and Technological Applications, Alexandria, Egypt.
⁷ Orbsen Therapeutics, National University of Ireland Galway, Galway, Ireland.
⁸ Regenerative Medicine Institute and Department of Medicine, National University of Ireland Galway, Galway, Ireland.
⁹ Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany.
¹⁰ Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Bochum, Germany.
¹¹ Department of Cardiology, Charité - Universitätsmedizin Berlin, Campus Virchow Klinikum, Berlin, Germany.

Abstract

Background: Mesenchymal stromal cells (MSCs) are an attractive cell type for cell therapy given their immunomodulatory, anti-fibrotic, and endothelial-protective features. The heparin sulfate proteoglycan, syndecan-2/CD362, has been identified as a functional marker for MSC isolation, allowing one to obtain a homogeneous cell product that meets regulatory requirements for clinical use. We previously assessed the impact of wild-type (WT), CD362^-, and CD362⁺ MSCs on local changes in protein distribution in left ventricular (LV) tissue and on LV function in an experimental model of early-onset diabetic cardiomyopathy. The present study aimed to further explore their impact on mechanisms underlying diastolic dysfunction in this model. Materials: For this purpose, 1 × 10⁶ WT, CD362^-, or CD362⁺ MSCs were intravenously (i.v.) injected into 20-week-old diabetic BKS.Cg-m+/+Lepr^db/BomTac, i.e., db/db mice. Control animals (db+/db) were injected with the equivalent volume of phosphate-buffered saline (PBS) alone. After 4 weeks, mice were sacrificed for further analysis. Results: Treatment with all three MSC populations had no impact on blood glucose levels in db/db mice. WT, CD362^-, and CD362⁺ MSC application restored LV nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) levels in db/db mice, which correlated with a reduction in cardiomyocyte stiffness. Furthermore, all stromal cells were able to increase arteriole density in db/db mice. The effect of CD362⁺ MSCs on NO and cGMP levels, cardiomyocyte stiffness, and arteriole density was less pronounced than in mice treated with WT or CD362^- MSCs. Analysis of collagen I and III protein expression revealed that fibrosis had not yet developed at this stage of experimental diabetic cardiomyopathy. All MSCs reduced the number of cardiac CD3⁺ and CD68⁺ cells in db/db mice, whereas only splenocytes from CD362^-- and CD362⁺-db/db mice exhibited a lower pro-fibrotic potential compared to splenocytes from db/db mice. Conclusion: CD362⁺ MSC application decreased cardiomyocyte stiffness, increased myocardial NO and cGMP levels, and increased arteriole density, although to a lesser extent than WT and CD362^- MSCs in an experimental model of early-onset diabetic cardiomyopathy without cardiac fibrosis. These findings suggest that the degree in improvement of cardiomyocyte stiffness following CD362⁺ MSC application was insufficient to improve diastolic function.

Keywords: angiogenesis; cardiac fibrosis; cardiomyocyte stiffness; diabetic cardiomyopathy; immunomodulation; syndecan-2/CD362+-selected stromal cells; type 2 diabetes.