Adipose stromal cell and sarpogrelate orchestrate the recovery of inflammation‐induced angiogenesis in aged hindlimb ischemic mice

Abstract

SummaryAging population displays a much higher risk of peripheral arterial disease (PAD) possibly due to the higher susceptibility, poor prognosis, and fewer therapeutic options. This study was designed to examine the impact of combined multipotent adipose‐derived stromal cells (mADSCs) and sarpogrelate treatment on aging hindlimb ischemia and the mechanism of action involved. mADSCs (1.0 × 107) constitutively expressing enhanced green fluorescent protein (eGFP) or firefly luciferase (Fluc) reporter were engrafted into the hindlimb of aged Vegfr2‐luc transgenic or FVB/N mice subjected to unilateral femoral artery occlusion, followed by a further administration of sarpogrelate. Multimodality molecular imaging was employed to noninvasively evaluate mADSCs' survival and therapeutic efficacy against aging hindlimb ischemia. Aged Tg(Vegfr2‐luc) mice exhibited decreased inflammatory response, and downregulation of vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor‐2 (VEGFR2) compared with young ones following hindlimb ischemia induction, resulting in angiogenesis insufficiency and decompensation for ischemia recovery. Engrafted mADSCs augmented inflammation‐induced angiogenesis to yield pro‐angiogenic/anti‐apoptotic effects partly via the VEGF/VEGFR2/mTOR/STAT3 pathway. Nonetheless, mADSCs displayed limited survival and efficacy following transplantation. Sarpogrelate treatment with mADSCs further upregulated mammalian target of rapamycin (mTOR)/STAT3 signal and modulated pro‐/anti‐inflammatory markers including IL‐1β/TNF‐α/IFN‐γ and IL‐6/IL‐10, which ultimately facilitated mADSCs' survival and therapeutic benefit in vivo. Sarpogrelate prevented mADSCs from hypoxia/reoxygenation‐induced cell death via a mTOR/STAT3‐dependent pathway in vitro. This study demonstrated a role of in vivo kinetics of VEGFR2 as a biomarker to evaluate cell‐derived therapeutic angiogenesis in aging. mADSCs and sarpogrelate synergistically restored impaired angiogenesis and inflammation modulatory capacity in aged hindlimb ischemic mice, indicating its therapeutic promise for PAD in the elderly.

Activation of Liver X Receptor Improves Viability of Adipose-Derived Mesenchymal Stem Cells to Attenuate Myocardial Ischemia Injury Through TLR4/NF-κB and Keap-1/Nrf-2 Signaling Pathways

“…1C). mADSCs Fluc + GFP + were positive for MSC markers CD90, CD44 and exhibited low expression of endothelial (CD34) and leukocyte markers (CD45), which represented the potential of differentiating into adipocytes and osteogenic cell lineages, as shown in our previous work (7). Furthermore, real-time quantitative PCR (RT-qPCR) and Western blot analysis revealed that the mRNA and protein expression of LXR a and LXR b were present in mAD-MSCs (Fig.…”

“…Other studies demonstrated that improving the conditions of this unfavorable niche in infarcted myocardium could increase the survival of injected stem cells (31,39). Our group also found that regulating local inflammation in ischemic tissue with sarpogrelate could enhance engrafted AD-MSCs viability and antiapoptotic/proangiogenic efficacy in vivo (7). In addition to microenvironmental regulation, increasing the stem cells' ability to resist local stress, such as local inflammation and oxidative stress, is also crucial for stem cell survival and efficacy (22,37).…”

“…Our data support the hypothesis that LXR agonist attenuates the inflammatory response in AD-MSCs under hypoxic conditions, and prevents oxidative stress induced by hypoxia injury through decreasing gp91 phox expression. As for the differentiation ability of transplanted AD-MSCs, our previous studies showed that transplanted MSCs rarely differentiated into cardiomyocytes in vivo (7,41). Other literature put forward the debate of whether implanted MSCs possess beneficial multipotent differentiation ability in infarcted myocardium (1).…”

Therapeutic efficacy of apelin on transplanted mesenchymal stem cells in hindlimb ischemic mice via regulation of autophagy

“…Nonetheless, the therapeutic efficacy has been held back by the poor survival of donor cells 3 . Our previous findings also demonstrated the feasibility of utilizing adipose derived mesenchymal stem cells (AD-MSCs) in the management of PAD courtesy of its multipotency, abundance for harvest and low immunogenicity 4 . However, low survival rate has been identified for the transplanted AD-MSCs within ischemic tissues, hampering the advancement of AD-MSCs in the therapeutics of PAD 4 .…”

“…Our previous findings also demonstrated the feasibility of utilizing adipose derived mesenchymal stem cells (AD-MSCs) in the management of PAD courtesy of its multipotency, abundance for harvest and low immunogenicity 4 . However, low survival rate has been identified for the transplanted AD-MSCs within ischemic tissues, hampering the advancement of AD-MSCs in the therapeutics of PAD 4 . To this end, it is pertinent to search for new and novel approaches to promote donor cell survival in order to foster the success of stem cell-based therapy for PAD.…”