Stem Cells

The liver can substantially regenerate after injury, with both main epithelial cell types, hepatocytes and biliary epithelial cells (BECs), playing important roles in parenchymal 

The turnover of the intestinal epithelium is driven by multipotent LGR5+ crypt-base columnar cells (CBCs) located at the bottom of crypt zones

Stem cell heterogeneity is recognized as functionally relevant for tissue homeostasis and repair. The identity, context dependence, and regulation of skeletal muscle satellite cell (SC) subsets remains poorly understood.

Cell-autonomous Wnt signaling has well-characterized functions in controlling stem cell activity, including in the prostate. While niche cells secrete Wnt ligands, the effects of Wnt signaling in niche cells per se are less understood. Here, we show that stromal cells in the proximal prostatic duct near the urethra, a mouse prostate stem cell niche, not only produce multiple Wnt ligands but also exhibit strong Wnt/β-catenin activity.

Much of the vertebrate skeleton develops from cartilage templates that are progressively remodeled into bone. Lineage tracing studies in mouse suggest that chondrocytes within these templates persist and become osteoblasts, yet the underlying mechanisms of this process and whether chondrocytes can generate other derivatives remain unclear. We find that zebrafish cartilages undergo extensive remodeling and vascularization during juvenile stages to generate fat-filled bones.

Summary Hair growth can be induced from resting mouse hair follicles by topical application of JAK inhibitors, suggesting that JAK-STAT signaling is required for maintaining hair follicle stem cells (HFSCs) in a quiescent state. Here, we show that Oncostatin M (OSM), an IL-6 family cytokine, negatively regulates hair growth by signaling through JAK-STAT5 to maintain HFSC quiescence. Genetic deletion of the OSM receptor or STAT5 can induce premature HFSC activation, suggesting that the resting telogen stage is actively maintained by the hair follicle niche.

AIM: To investigate the expression of embryonic stem cell (ESC) markers in microcystic lymphatic malformation (mLM). METHODS AND RESULTS: Cervicofacial mLM tissue samples from nine patients underwent 3,3'-diaminobenzidine (DAB) immunohistochemical (IHC) staining for ESC markers octamer-binding protein 4 (OCT4), homeobox protein NANOG, sex determining region Y-box 2 (SOX2), Krupple-like factor (KLF4), and proto-oncogene c-MYC.

The growth plate provides a substantial source of mesenchymal cells in the endosteal marrow space during endochondral ossification. The current model postulates that a group of chondrocytes in the hypertrophic zone can escape from apoptosis and transform into cells that eventually become osteoblasts in an area beneath the growth plate. The growth plate is composed of cells with various morphologies; particularly, at the periphery of the growth plate immediately adjacent to the perichondrium are 'borderline' chondrocytes, which align perpendicularly to other chondrocytes.

Intestinal epithelial cells have a defined hierarchy with stem cells located at the bottom of the crypt and differentiated cells more at the top. Epithelial cell renewal and differentiation are strictly controlled by various regulatory signals provided by epithelial as well as surrounding cells. Although there is evidence that stromal cells contribute to the intestinal stem cell niche, their markers and the soluble signals they produce have been incompletely defined.

MEIS1 is a key developmental regulator of several organs and participates in stem cell maintenance in different niches. However, despite the murine continuously growing incisor being a well described model for the study of adult stem cells, Meis1 has not been investigated in a dental context. Here, we uncover that Meis1 expression in the tooth is confined to the epithelial compartment. Its expression arises during morphogenesis and becomes restricted to the mouse incisor epithelial stem cell niche, the labial cervical loop.