BMP-2 generates a functional bone marrow niche by inducing the differentiation of local mesenchymal cells into CAR cells.

Ectopic bone marrow (eBM) holds tremendous potential as an artificial organ, serving not only in stem cell transplantation therapies but also as a controlled experimental system for analyzing cellular dynamics and interactions between cells and the matrix during the formation, maintenance, and aging of bone marrow (BM). Although bone morphogenetic protein (BMP)-2 has been reported to induce eBM formation, it remains unproven whether BMP-2 induced eBM (BMP-eBM) can provide a functional BM niche that is comparable to native BM in long bones (LB-BM). In this study, through the use of single-cell RNA sequencing and transplantation models, we demonstrate for the first time that BMP-eBM displays a microstructure, cellular composition, and functional hematopoiesis similar to LB-BM.

Tryptophan and Kynurenine Enhances the Stemness and Osteogenic Differentiation of Bone Marrow-Derived Mesenchymal Stromal Cells In Vitro and In Vivo.

Aging tissues present a progressive decline in homeostasis and regenerative capacities, which has been associated with degenerative changes in tissue-specific stem cells and stem cell niches. We hypothesized that amino acids could regulate the stem cell phenotype and differentiation ability of human bone marrow-derived mesenchymal stromal cells (hBMSCs). Thus, we performed a screening of 22 standard amino acids and found that D-tryptophan (10 μM) increased the number of cells positive for the early stem cell marker SSEA-4, and the gene expression levels of , , and in hBMSCs.