Systemic transplantation of adult multipotent stem cells prevents articular cartilage degeneration in a mouse model of accelerated ageing

Abstract

Background: Osteoarthritis (OA) is one of the most prevalent joint diseases of advanced age and is a leading cause of disability worldwide. Ageing is a major risk factor for the articular cartilage (AC) degeneration that leads to OA, and the age-related decline in regenerative capacity accelerates OA progression. Here we demonstrate that systemic transplantation of a unique population of adult multipotent muscle-derived stem/progenitor cells (MDSPCs), isolated from young wild-type mice, into Zmpste24^-/- mice (a model of Hutchinson-Gilford progeria syndrome, a condition marked by accelerated ageing), prevents ageing-related homeostatic decline of AC.

Results: MDSPC treatment inhibited expression of cartilage-degrading factors such as pro-inflammatory cytokines and extracellular matrix-proteinases, whereas pro-regenerative markers associated with cartilage mechanical support and tensile strength, cartilage resilience, chondrocyte proliferation and differentiation, and cartilage growth, were increased. Notably, MDSPC transplantation also increased the expression level of genes known for their key roles in immunomodulation, autophagy, stress resistance, pro-longevity, and telomere protection. Our findings also indicate that MDSPC transplantation increased proteoglycan content by regulating chondrocyte proliferation.

Conclusions: Together, these findings demonstrate the ability of systemically transplanted young MDSPCs to preserve a healthy homeostasis and promote tissue regeneration at the molecular and tissue level in progeroid AC. These results highlight the therapeutic potential of systemically delivered multipotent adult stem cells to prevent age-associated AC degeneration.

Keywords: Accelerated ageing; Adult stem cells; Articular cartilage; Progeria; Regenerative medicine; Transplantation.

Fig. 1

Alteration in Gene Expression Profile of Articular Cartilage in Zmpste24-deficient (Zmpste24^−/−) Progeroid Mice. Articular cartilage from 5–6 month-old adult wild type (n = 6) and age-matched Zmpste24^−/− littermate knee joints (n = 5) were analyzed for the mRNA expression level of (a-c genes encoding pro-inflammatory cytokines and senescence-associated secretory phenotype (SASP) factors (Il1a, Il6, and Tnf), extracellular matrix (ECM) proteinases (Mmp3, Mmp13, and Adamts5), ECM components (Col1a1, Col2a1, Acan, Vcan, and Bgn) using qRT-PCR. d-e Genes associated with telomere protection (Pot1b), autophagy suppression (Mtor), antioxidant response (Gpx4), and oxidative stress-response (Sod1). Expression values are relative to housekeeping genes, Gapdh and Hmgb1. Data are mean ± SEM. **p < 0.01, ***p < 0.001, ^#p < 0.0001, ^ǂp < 0.000001, ns: not significant using two-tailed, unpaired Student’s t-test or Welch’s unequal variance t-test

Fig. 2

Effect of Young MDSPC Systemic Transplantation in the Zmpste24^−/− Progeroid Mouse Articular Cartilage Microenvironment. a Schematic illustrating the experimental design. b-d Quantitation of pro-inflammatory cytokines and SASP markers (Il1a, Il6, and Tnf) and anti-inflammatory cytokine (Il10), extracellular matrix (ECM) proteinases (Mmp3, Mmp13, and Adamts5), and ECM components (Col1a1, Col2a1, Acan, Vcan, and Bgn) relative mRNA levels, measured by qRT-PCR from the knee articular cartilage of Zmpste24^−/− mice intraperitoneally (IP) injected with MDSPCs (Z-IP, n = 7) or PBS (Z-PBS, n = 9). Expression values are relative to housekeeping genes, Gapdh and Hmgb1. Data are mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001, ^#p < 0.0001, ^§p < 0.00001, ^ǂp < 0.000001, ns: not significant using two-tailed, unpaired Student’s t-test or Welch’s unequal variance t-test

Fig. 3

Systemic Transplantation of young MDSPCs Promotes a Healthy Cartilage Homeostasis in Zmpste24^−/− Progeroid Mice. Relative mRNA levels were measured by qRT-PCR from the knee articular cartilage of Zmpste24^−/− mice intraperitoneally (IP) injected with MDSPCs (Z-IP, n = 7) or PBS (Z-PBS, n = 9) and analyzed for the presence of (a) a key ageing signaling pathway mediator (Nfkb1), its inhibitor (Nfkbia), autophagy and pro-longevity markers (Foxo1 and Foxo3), and telomere protection (Pot1b), (b) antioxidant response (Gpx4), oxidative stress-response (Sod1), and growth arrest and DNA damage response (Gadd45a), (c) endocytosis and stress-induced senescence (Cav1), the cellular senescence/tumor suppressor mechanism (Cdkn2a), and the mammalian target of rapamycin (Mtor) genes. Expression values are relative to housekeeping genes, Gapdh and Hmbg1. Data are mean ± SEM. **p < 0.01, ***p < 0.001, ^#p < 0.0001, ^§p < 0.00001, ^ǂp < 0.000001, ns: not significant using two-tailed, unpaired Student’s t-test or Welch’s unequal variance t-test (a-c and e-g)

Fig. 4

Histopathology of Articular Cartilage Following Systemic Transplantation of Young MDSPCs in Zmpste24^−/− Mice. a Representative images (20x magnification) of Safranin-O (Saf-O) stained femoral condyle and tibial plateau from PBS- (Z-PBS, n = 3) and MDSPC-intraperitoneally transplanted (Z-IP; n = 3) Zmpste24^−/− mice at 5–6 months of age. Quantitative histomorphometric analysis shows (b) total cartilage area, (c) percent of Saf-O + cartilage area, (d) chondrocyte number, and (e) chondrocyte density. Data are mean ± SEM. *p < 0.05 with two-tailed, unpaired Student’s t-test