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The skin is responsible for a variety of physiological functions and is critical for wound healing and repair. Therefore, the regenerative capacity of the skin is important. However, stem cells responsible for maintaining the acral epithelium had not previously been identified. In this study, we identified the specific stem cells in the acral epithelium that participate in the long-term maintenance of sweat glands, ducts, and interadnexal epidermis and that facilitate the regeneration of these structures following injury. Lgr6-positive cells and Bmi1-positive cells were found to function as long-term multipotent stem cells that maintained the entire eccrine unit and the interadnexal epidermis. However, while Lgr6-positive cells were rapidly cycled and constantly supplied differentiated cells, Bmi1-positive cells were slow to cycle and occasionally entered the cell cycle under physiological conditions. Upon irradiation-induced injury, Bmi1-positive cells rapidly proliferated and regenerated injured epithelial tissue. Therefore, Bmi1-positive stem cells served as reservoir stem cells. Lgr5-positive cells were rapidly cycled and maintained only sweat glands; therefore, we concluded that these cells functioned as lineage-restricted progenitors. Taken together, our data demonstrated the identification of stem cells that maintained the entire acral epithelium and supported the different roles of three cellular classes. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mesenchymal stem cells (MSCs) are thought to conduct spinal ligament ossification. [•] Osteogenic differentiation potential is higher in MSCs from ossification patients. [•] Osteogenic gene expression is higher in MSCs from ossification patients. [•] Cellular propensity toward osteogenic lineage is a causal factor of ossification. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mesenchymal stem cells (MSCs) are localized in pericytes and collagenous matrix. [•] High prevalence of MSCs in regions of ossification of the ligamentum flavum (OLF). [•] Chondrocytes near the ossification front were positive for MSCs markers. [•] MSCs may participate in chondrocyte differentiation in ectopic ossification. [•] Analysis of MSC-directed chondrogenesis in OLF may elucidate ectopic ossification. [ABSTRACT FROM AUTHOR]

Abstract: We recently reported that the single nucleotide polymorphisms of the lymphotoxin-(LT)α gene, a member of the tumor necrosis factor (TNF) family, are closely related to acute myocardial infarction; however, the precise mechanism of LTα signaling in atherogenesis remains unclear. We investigated the role of LTα3, a secreted homotrimer of LTα, in monocyte–endothelial cell adhesion using cultured human umbilical vein endothelial cells (HUVEC). We found that LTα3 induced cell adhesion molecules and activated NF-κB p50 and p65. LTα3 also induced phosphorylation of Akt, phosphorylation and degradation of IκB, nuclear translocation of p65, and increased adhesion of THP1 monocytes to HUVEC. These effects were mediated by TNF receptor (TNFR) I and attenuated by the phosphatidylinositol triphosphate-kinase (PI3K) inhibitors LY294002 and Wortmannin. Thus, LTα3 mediates the monocyte–endothelial interaction via the classical NF-κB pathway following TNFR I/PI3K activation, indicating it may play a role in the development of coronary artery disease. [Copyright &y& Elsevier]