Characterization of Lgr5-positive epithelial cells in the murine thymus

Therapeutic potential of human minor salivary gland epithelial progenitor cells in liver regeneration

Liver disease is a serious problem affecting millions of people with continually increasing prevalence. Stem cell therapy has become a promising treatment for liver dysfunction. We previously reported on human minor salivary gland mesenchymal stem cells (hMSGMSCs), which are highly self-renewable with multi-potent differentiation capability. In this study, keratinocyte-like cells with self-regeneration and hepatic differentiation potential were isolated and characterized, and named human minor salivary gland epithelial progenitor cells (hMSG-EpiPCs). hMSG-EpiPCs were easily obtained via minor intraoral incision; they expressed epithelial progenitor/stem cell and other tissue stem cell markers such as CD29, CD49f, cytokeratins, ABCG2, PLET-1, salivary epithelial cell markers CD44 and CD166, and the Wnt target related gene LGR5 and LGR6. The cells were induced into functional hepatocytes in vitro which expressed liver-associated markers ALB, CYP3A4, AAT, and CK18. Upon transplantation in vivo, they ameliorated severe acute liver damage in SCID mice caused by carbon tetrachloride (CCl₄) injection. In a two-thirds partial hepatectomy mouse model, the transplanted cells survived at least 4 weeks and exhibited hepatic potential. These findings demonstrate that hMSG-EpiPCs have potential as a cellular therapy basis for hepatic diseases, physiological and toxicology studies and regenerative medicine.

Lgr5-positive cells in the lung and their clinical significance in patients with lung adenocarcinoma

Leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5) is well-characterized as a marker of intestinal stem cells and certain types of tumor stem cells, where positive cells may develop into intestinal epithelial cells or intestinal adenomas. However, the roles of Lgr5 in the lung and in lung tumors remain unclear. An immunohistochemistry (IHC) analysis was performed to detect the expression of Lgr5 in the lung from a normal mouse. Histopathological sections of the lungs from Lgr5 heterozygous knockout mice (Lgr5^+/−) were observed following with hematoxylin and eosin. Furthermore, tissue microarrays containing tumor cores from lung cancer patients were also analyzed by IHC. Lgr5-positive cells were present in the pulmonary alveoli and bronchi of normal mice, whereas the lungs of Lgr5^+/− mice lost their normal morphological structure compared with the lungs of the normal mice. Lgr5 was expressed in lung adenocarcinoma, however, not in squamous carcinoma, and Lgr5 expression was positively associated with tumor, node, metastasis stage. Lgr5 is expressed in normal murine lung and is associated with TNM stage in patients with lung adenocarcinoma.