Transplantation of Mesenchymal Stem Cells Overexpressing RANK-Fc or CXCR4 Prevents Bone Loss in Ovariectomized Mice

Abstract

Osteoporosis is a systemic skeletal disorder characterized by reduced bone mineral density (BMD) and increased risk of fracture. We studied the effects of transplantation of mesenchymal stem cells (MSCs) overexpressing receptor activator of nuclear factor-kappaB (RANK)-Fc and CXC chemokine receptor-4 (CXCR4) using retrovirus on ovariectomy (OVX)-induced bone loss in mice. Ten-week-old adult female C57BL/6 mice were divided into six groups as follows: Sham-operated mice treated with phosphate-buffered saline (PBS) (Sham-op + PBS); OVX mice intravenously transplanted with syngeneic MSCs overexpressing RANK-Fc-DsRED and CXCR4-GFP (RANK-Fc + CXCR4); RANK-Fc-DsRED and GFP (RANK-Fc + GFP); CXCR4-GFP and DsRED (CXCR4 + RED); DsRED and GFP (RED + GFP); or treated with PBS only (OVX + PBS). Measurement of BMD showed that introduction of RANK-Fc resulted in significant protection against OVX-induced bone loss compared to treatment with PBS (-0.1% versus -6.2%, P < 0.05) at 8 weeks after cell infusion. CXCR4 + RED group also significantly prevented bone loss compared to OVX + PBS group (2.7% versus -6.2%, P < 0.05). Notably, the effect of RANK-Fc + CXCR4 was greater than that of RANK-Fc + GFP (4.4% versus -0.1%, P < 0.05) while it was not significantly different from that in CXCR4 + RFP group (4.4% versus 2.7%, P = 0.055) at 8 weeks. Transplantation of MSCs with control virus (RED + GFP group) also resulted in amelioration of bone loss compared to OVX + PBS group (-1.7% versus -6.2%, P < 0.05). Fluorescence-activated cell sorting (FACS) and real-time quantitative PCR (qPCR) analysis for GFP from bone tissue revealed enhanced cell trafficking to bone by co-overexpression of CXCR4. In conclusion, we have demonstrated that intravenous transplantation of syngeneic MSCs overexpressing CXCR4 could promote increased in vivo cell trafficking to bone in OVX mice, which could in itself protect against bone loss but also enhance the therapeutic effects of RANK-Fc.

CXCR4-transduced mesenchymal stem cells protect mice against graft-versus-host disease

“…However, both human and mouse MSCs express low levels of surface CXCR4 after in vitro expansion [34,35]. After overexpressing CXCR4 on MSCs by lentiviral gene transfer, we observed enhanced migration of these cells towards an SDF-1 chemokine gradient, consistent with previous studies with human BM derived MSCs or adipose tissue derived MSCs [29,36,37]. In Matrigel invasion assays, BobisWozowicz et al [36] and Zhang et al [37] have demonstrated that the increased migration of CXCR4-modified MSCs is related to increase production of MMP-2, MMP-9 and TIMP-1, which regulates the degradation of extracellular matrix proteins.…”

“…The chemokine stromal-derived factor 1 (SDF-1)/CXCR4 axis has been shown to play an important role in stem cell seeding in the BM during murine embryonic development, as well as in stem cell homing after transplantation [27]. Recently, it was shown that high levels of CXCR4 expression on human MSCs correlate with higher engraftment at an injury site [28,29]. Here, we used a lentiviral gene vector to overexpress mouse CXCR4 on mouse MSCs and examined their migratory ability in vitro as well as their immunosuppressive capacity in a mouse GVHD model.…”

Transplantation of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells or Their Conditioned Medium Prevents Bone Loss in Ovariectomized Nude Mice

“…16 Furthermore, cotransduction of CXCR4, a chemokine that enhances homing to BM spaces across the stromal cell-derived factor-1 gradient, did not improve engrafting of the transplanted BM-MSCs in the long term, although the bone mass gain was greater compared with that achieved by CXCR4 ( -) cells. 17 Consistent with these studies, the efficiencies of shortterm homing and long-term engraftment of hUCB-MSCs in this study do not seem to be sufficient for any positive effects on bone mass. Using adipocyte-derived MSC transplantation, we found that most transplanted cells are trapped in the lung 48 h after intravenous injection.…”

“…We previously reported the protective effect of systemic transplantation of syngeneic murine bone marrow-derived MSCs (BM-MSCs) that were retrovirally transduced with RANK-Fc 16 or RANK-Fc + CXCR4 17 in ovariectomy (OVX)-induced bone loss in mice. In these studies, transplantation of MSCs effectively prevents bone loss despite their poor BM homing and short-term engraftment, suggesting that these favorable effects are mediated by secretory factors from MSCs rather than direct engraftment.…”

Mesenchymal stem cells expressing osteoprotegerin variants inhibit osteolysis in a murine model of multiple myeloma

“…19,20 It has also been shown that MSCs home to sites of injury and tumor, and this homing mechanism is being exploited as a means for therapeutic payload. [22][23][24][25] Evaluation of preclinical therapeutic strategies for osteolytic lesions in myeloma bone disease is mostly limited to testing in localized tumor growth models following myeloma cell implantation. However, the disease in humans is characterized by osteolytic destruction in most major bones of the skeleton.…”