Inflammation, mesenchymal stem cells and bone regeneration

Abstract

Achieving satisfactory reconstruction of bone remains an important goal in orthopedic and dental conditions such as bone trauma, osteoporosis, arthritis, osteonecrosis, and periodontitis. Appropriate temporal and spatial differentiation of mesenchymal stem cells (MSCs) is essential for postnatal bone regeneration. Additionally, an acute inflammatory response is crucial at the onset of bone repair, while an adaptive immune response has important implications during late bone remodeling. Various reports have indicated bidirectional interactions between MSCs and inflammatory cells or molecules. For example, inflammatory cells can recruit MSCs, direct their migration and differentiation, so as to exert anabolic effects on bone repair. Furthermore, both pro-inflammatory and anti-inflammatory cytokines can regulate MSCs properties and subsequent bone regeneration. MSCs have demonstrated highly immunosuppressive functions, such as inhibiting the differentiation of monocytes/hematopoietic precursors and suppressing the secretion of pro-inflammatory cytokines. This review emphasizes the important interactions between inflammatory stimuli, MSCs, and bone regeneration as well as the underlying regulatory mechanisms. Better understanding of these principles will provide new opportunities for promoting bone regeneration and the treatment of bone loss associated with immunological diseases.

Hyperbaric Oxygen Therapy Improves the Osteogenic and Vasculogenic Properties of Mesenchymal Stem Cells in the Presence of Inflammation In Vitro

“…Inflammation also represents a crucial event in the process of bone repair, being the initial inflammatory response necessary for the regeneration to progress [10]. In fact, inflammatory stimuli determine the recruitment of Mesenchymal Stem Cells (MSCs), and direct their migration, proliferation and differentiation into mature osteoblasts [11]. At the same time, MSCs modulate inflammatory cells to promote resolution of pro-inflammatory activities, and reconstitution of normal tissue [12].…”

The effect of platelet‐rich fibrin exudate addition to porous poly(lactic‐co‐glycolic acid) scaffold in bone healing: An in vivo study

“…In the case of the allograft, the harvesting protocol and quality control has a direct impact on the clinical outcome. Due to the cadaverous nature of the graft source, disease transmission and infection control is also of high significance (Liu, Li, Zhang, & Li, ). The shortcomings of each graft materials lead to the clinician exercising careful clinical judgment in order to select the type of graft that minimizes the adverse effects.…”

Mesenchymal Stem Cells Beyond Regenerative Medicine

“…For example, lower ratios tip the suppressive balance in favor of MSCs which become capable of inducing phenotypic and secretory changes in NK cells via physical and paracrine interactions, thereby restricting their cytotoxicity and proliferation (Sotiropoulou et al, 2006;Jewett et al, 2010;Spaggiari and Moretta, 2012). Proinflammatory signals also support MSC differentiation through multiple receptors like TLRs and signaling pathways like NF-κB, p38 mitogen-activated protein (MAP) kinase, and β-catenin, ultimately inducing the transcription of lineage-specific genes Wei et al, 2013;Chen et al, 2016;Liu et al, 2018). For instance, NF-κB and MAP kinase pathways are activated by stromal cell-derived factor-1 (SDF-1), a pleotropic chemokine secreted by several cells and organs, which acts as a chemoattractant for MSCs in regenerative settings (Kucia et al, 2004).…”