Introduction: Liver transplantation is a gold standard treatment for intractable liver diseases. Because of the shortage of donor organs, alternative therapies have been required. Due to their potential to differentiate into a variety of mature cells, stem cells are considered feasible cell sources for liver regeneration. Stem cells from human exfoliated deciduous teeth (SHED) exhibit hepatogenic capability in vitro. In this study, we investigated their in vivo capabilities of homing and hepatocyte differentiation and therapeutic efficacy for liver disorders in carbon tetrachloride (CCl₄)-induced liver fibrosis model mice. Methods: We transplanted SHED into CCl₄-induced liver fibrosis model mice through the spleen, and analyzed the in vivo homing and therapeutic effects by optical, biochemical, histological, immunological and molecular biological assays. We then sorted human leukocyte antigen-ABC (HLA-ABC)-positive cells from primary CCl4-damaged recipient livers, and analyzed their fusogenicity and hepatic characteristics by flow cytometric, genomic DNA, hepatocyte-specific gene assays. Furthermore, we examined the treatment effects of HLA-positive cells to a hepatic dysfunction by a secondary transplantation into CCl₄-treated mice. Results: Transplanted SHED homed to recipient livers, and expressed HLA-ABC, human hepatocyte specific antigen hepatocyte paraffin 1 and human albumin. SHED transplantation markedly recovered liver dysfunction and led to anti-fibrotic and anti-inflammatory effects in the recipient livers. SHED-derived HLA-ABC-positive cells that were sorted from the primary recipient liver tissues with CCl₄ damage did not fuse with the host mouse liver cells. Sorted HLA-positive cells not only expressed human hepatocyte-specific genes including albumin, cytochrome P450 1A1, fumarylacetoacetase, tyrosine aminotransferase, uridine 5′-diphospho-glucuronosyltransferase, transferrin and transthyretin, but also secreted human albumin, urea and blood urea nitrogen. Furthermore, SHED-derived HLA-ABC-positive cells were secondary transplanted into CCl₄-treated mice. The donor cells homed into secondary recipient livers, and expressed hepatocyte paraffin 1 and human albumin, as well as HLA-ABC. The secondary transplantation recovered a liver dysfunction in secondary recipients. Conclusions: This study indicates that transplanted SHED improve hepatic dysfunction and directly transform into hepatocytes without cell fusion in CCl₄-treated mice, suggesting that SHED may provide a feasible cell source for liver regeneration.

Background: Human deciduous pulp stem cells (hDPSCs) have remarkable stem cell potency associated with cell proliferation, mesenchymal multipotency, and immunosuppressive function and have shown beneficial effects in a variety of animal disease models. Recent studies demonstrated that hDPSCs exhibited in vivo anti-fibrotic and anti-inflammatory action and in vivo hepatogenic-associated liver regeneration, suggesting that hDPSCs may offer a promising source with great clinical demand for treating liver diseases. However, how to manufacture ex vivo large-scale clinical-grade hDPSCs with the appropriate quality, safety, and preclinical efficacy assurances remains unclear. Methods: We isolated hDPSCs from human deciduous dental pulp tissues formed by the colony-forming unit-fibroblast (CFU-F) method and expanded them under a xenogeneic-free and serum-free (XF/SF) condition; hDPSC products were subsequently stored by two-step banking including a master cell bank (MCB) and a working cell bank (WCB). The final products were directly thawed hDPSCs from the WCB. We tested the safety and quality check, stem cell properties, and preclinical potentials of final hDPSC products and hDPSC products in the MCB and WCB. Results: We optimized manufacturing procedures to isolate and expand hDPSC products under a XF/SF culture condition and established the MCB and the WCB. The final hDPSC products and hDPSC products in the MCB and WCB were validated the safety and quality including population doubling ability, chromosome stability, microorganism safety, and stem cell properties including morphology, cell surface marker expression, and multipotency. We also evaluated the in vivo immunogenicity and tumorigenicity and validated in vivo therapeutic efficacy for liver regeneration in a CCl₄-induced chronic liver fibrosis mouse model in the final hDPSC products and hDPSC products in the WCB. Conclusion: The manufacture and quality control results indicated that the present procedure could produce sufficient numbers of clinical-grade hDPSC products from a tiny deciduous dental pulp tissue to enhance clinical application of hDPSC products in chronic liver fibrosis.

Purpose: Laparoscopic percutaneous extraperitoneal closure (LPEC) has been performed in Japan for the repair of the pediatric inguinal hernias for over a decade. However, the safety and efficacy of LPEC in neonates and infants under 1 year of age remain unknown. The aim of the present study is to elucidate the safety and efficacy of LPEC in the treatment of inguinal hernia in patients who are younger than 1 year of age. Patients and Methods: The medical records of the patients who underwent LPEC at Saga-Ken Medical Center Koseikan (Saga, Japan) between August 2007 and November 2012 were collected. The intraoperative findings and postoperative outcomes were retrospectively investigated. The data of the patients who were younger than 1 year of age (Group A) were compared with the data of patients who were older than 1 year of age (Group B). Results: During the study period, 150 LPEC procedures were performed in 112 Group A patients, whereas 607 LPEC procedures were performed in 456 Group B patients. There were no serious complications in either group. After a mean follow-up period of 50.4 ± 15.6 months (range, 28–91 months), there were no significant differences between the two groups in the operating time or the incidence of intraoperative or postoperative complications. Postoperative testicular ascent and recurrence were observed in some cases of each group. Conclusions: LPEC is a safe and effective procedure for the repair of an inguinal hernia, even in neonatal and infant patients who are younger than 1 year of age.