Reversible secretome and signaling defects in diabetic mesenchymal stem cells from peripheral arterial disease patients

Conditioned medium from primary cytotrophoblasts, primary placenta-derived mesenchymal stem cells, or sub-cultured placental tissue promoted HUVEC angiogenesis in vitro

Background

As a large capillary network, the human placenta plays an important role throughout pregnancy. Placental vascular development is complex and delicate and involves many types of placental cells, such as trophoblasts, and mesenchymal stem cells. There has been no systematic, comparative study on the roles of these two groups of placental cells and the whole placental tissue in the placental angiogenesis. In this study, primary cytotrophoblasts (CTBs) from early pregnancy and primary human placenta-derived mesenchymal stem cells (hPDMSCs) from different stages of pregnancy were selected as the cell research objects, and full-term placental tissue was selected as the tissue research object to detect the effects of their conditioned medium (CM) on human umbilical vein endothelial cell (HUVEC) angiogenesis.

Methods

We successfully isolated primary hPDMSCs and CTBs, collected CM from these placental cells and sub-cultured placental tissue, and then evaluated the effects of the CM on a series of angiogenic processes in HUVECs in vitro. Furthermore, we measured the levels of angiogenic factors in the CM of placental cells or tissue by an angiogenesis antibody array.

Results

The results showed that not only placental cells but also sub-cultured placental tissue, to some extent, promoted HUVEC angiogenesis in vitro by promoting proliferation, adhesion, migration, invasion, and tube formation. We also found that primary placental cells in early pregnancy, whether CTBs or hPDMSCs, played more significant roles than those in full-term pregnancy. Placental cell-derived CM collected at 24 h or 48 h had the best effect, and sub-cultured placental tissue-derived CM collected at 7 days had the best effect among all the different time points. The semiquantitative angiogenesis antibody array showed that 18 of the 43 angiogenic factors had obvious spots in placental cell-derived CM or sub-cultured placental tissue-derived CM, and the levels of 5 factors (including CXCL-5, GRO, IL-6, IL-8, and MCP-1) were the highest in sub-cultured placental tissue-derived CM.

Conclusions

CM obtained from placental cells (primary CTBs or hPDMSCs) or sub-cultured placental tissue contained proangiogenic factors and promoted HUVEC angiogenesis in vitro. Therefore, our research is helpful to better understand placental angiogenesis regulation and provides theoretical support for the clinical application of placental components, especially sub-cultured placental tissue-derived CM, in vascular tissue engineering and clinical treatments.

Bone marrow-derived mesenchymal stem cells microvesicles stabilize atherosclerotic plaques by inhibiting NLRP3-mediated macrophage pyroptosis

Rupture of atherosclerotic plaques constitutes the major cause of thrombosis and acute ischemic coronary syndrome. Bone marrow-derived mesenchymal stem cells microvesicles (BMSCs-MVs) are reported to promote angiogenesis. This study investigated the role of BMSCs-MVs in stabilizing atherosclerotic plaques. BMSCs-MVs in mice were isolated and identified. The mouse model of atherosclerosis was established, and mice were injected with BMSCs-MVs via the tail vein. The macrophage model with high glucose and oxidative damage was established and then incubated with BMSCs-MVs. Nod-like receptor protein 3 (NLRP3) expression, pyroptosis-related proteins, and inflammatory factors were detected. Actinomycin D was used to inhibit the secretion of BMSCs-MVs to verify the source of microRNA-223 (miR-223). The binding relationship between miR-223 and NLRP3 was predicted and verified. BMSCs-MVs with knockdown of miR-223 were cocultured with bone marrow-derived macrophages with knockdown of NLRP3, and then levels of miR-223, NLRP3, pyroptosis-related proteins, and inflammatory factors were detected. BMSCs-MVs could reduce the vulnerability index of atherosclerotic plaques and intima-media thickness in mice, and inhibit pyroptosis and inflammation. BMSCs-MVs inhibited pyroptosis and inflammatory factors in macrophages. BMSCs-MVs carried miR-223 to inhibit NLRP3 expression and reduce macrophage pyroptosis, thereby stabilizing the atherosclerotic plaques.

Mesenchymal Stromal Cell-Based Bone Regeneration Therapies: From Cell Transplantation and Tissue Engineering to Therapeutic Secretomes and Extracellular Vesicles

Effective regeneration of bone defects often presents significant challenges, particularly in patients with decreased tissue regeneration capacity due to extensive trauma, disease, and/or advanced age. A number of studies have focused on enhancing bone regeneration by applying mesenchymal stromal cells (MSCs) or MSC-based bone tissue engineering strategies. However, translation of these approaches from basic research findings to clinical use has been hampered by the limited understanding of MSC therapeutic actions and complexities, as well as costs related to the manufacturing, regulatory approval, and clinical use of living cells and engineered tissues. More recently, a shift from the view of MSCs directly contributing to tissue regeneration toward appreciating MSCs as "cell factories" that secrete a variety of bioactive molecules and extracellular vesicles with trophic and immunomodulatory activities has steered research into new MSC-based, "cell-free" therapeutic modalities. The current review recapitulates recent developments, challenges, and future perspectives of these various MSC-based bone tissue engineering and regeneration strategies.