Signature quality attributes of CD146+ mesenchymal stem/stromal cells correlate with high therapeutic and secretory potency

Abstract

CD146 + bone marrow-derived Mesenchymal Stem/Stromal Cells (BM-MSC) play key roles in the perivascular niche, skeletogenesis and hematopoietic support, however elucidation of therapeutic potency has yet to be determined. Here, inflammatory challenge to crude BM-MSC captured a baseline of signatures including enriched expression of CD146 + with CD107a + , CXCR4 + , and LepR + , transcriptional profile, enhanced secretory capacity, robust secretome and immunomodulatory function with stimulated target immune cells. These responses were significantly more pronounced in CD146 + (POS)-selected subpopulation than in the CD146 -(NEG). Mechanistically, POS uniquely mediated robust immunosuppression while inducing significant frequencies of Naïve and Regulatory T cells in vitro. Moreover, POS promoted a pivotal M1-to-M2 macrophage shift in vivo, ameliorating inflammation/fibrosis of joint synovium and fat pad of the knee, failed by NEG. This study provides high-content evidence of CD146 + CD107a + BM-MSC, herein deemed 'first responders' to inflammation, as the underrepresented subpopulation within crude BM-MSC with innately higher secretory capacity and therapeutic potency. HIGHLIGHTS• Signature phenotypic, transcriptional, and secretome profiles were identified and enriched in human CD146 + (POS)-selected subpopulation in response to inflammation • Inflammatory challenge consistently altered stemness (LIF) and differentiation master regulators (SOX9, RUNX2, PPARγ) in crude, POS, and NEG BM-MSC, and deduced unique expressions in POS compared to NEG • POS BM-MSC mediated the strongest immunomodulation, e.g. target immune cell suppression, Treg induction, diminished T cell differentiation • POS BM-MSC promoted the largest M1-to-M2 shift in vivo alleviating induced synovitis and infrapatellar fat pad fibrosis of the knee

Infrapatellar Fat Pad-derived Mesenchymal Stem Cell-based Spheroids Enhance Their Therapeutic Efficacy to Reverse Synovitis and Fat Pad Fibrosis

“…Collectively, these data demonstrate the reinforcing effect of spheroid culturing on IFP-MSC propensities even in non-induced cultures without any exogenous pro-inflammatory/pro-fibrotic priming. Upon CD146-based selection, the generated subpopulations showed distinct protein, molecular and secretory profiles, similar to our previous report with BM-MSC [30]. As highlighted in our previous reports CD146 and CD10 are both key molecules correlated with increased immunomodulatory MSC functionality [27-IFP-MSC spheroids reverse synovitis/IFP fibrosis 29].…”

“…On the other hand, we have also recently reported that a similar inflammatory cell priming protocol applied to bone marrow-derived MSC (BM-MSC) enriches the preparation in CD146 + cells, unveiling a subset with innately higher immunomodulatory and secretory capacities compared to their CD146counterparts [30]. A comparable CD146-dependent phenotypic and functional discrimination in IFP-MSC has not been reported yet.…”

Human fetal liver MSCs are more effective than adult bone marrow MSCs for their immunosuppressive, immunomodulatory and Foxp3+ T regs induction capacity

“…This results match with a study showing that CD146 + BM-MSCs showed greater immunomodulatory functions upon in ammatory priming compared to CD146 -BM-MSCs. 94 We also noticed that FL-MSCs contained both CD271 bright , and CD271 low cells, while adult BM-MSCs cultures contained only CD271 low cells. This nding is consistent with previous studies demonstrating that CD271 high cells have a much higher clonogenic capacity than CD271 low cells, [76][77][78] and with our data showing that when seeded in a strictly identical initial number, FL-MSCs proliferate more than BM-MSCs with an effect discernible from day 2.…”

Infrapatellar Fat Pad/Synovium Complex in Early-Stage Knee Osteoarthritis: Potential New Target and Source of Therapeutic Mesenchymal Stem/Stromal Cells

“…In fact, it has been proposed that MSC can indeed promote M2 macrophage polarization in vitro (Harrell et al, 2019). Furthermore, our group recently reported the switch of IFP macrophages from an M1 to an M2 phenotype in vivo, after a single intra-articular injection of a subset of BM-MSC (CD146 + ) in rats with induced synovitis and IFP fibrosis (Bowles et al, 2020).…”