Human Cord Blood Cells Transplanted Into Chronically Damaged Liver Exhibit Similar Characteristics to Functional Hepatocytes

The Efficiency of Neurospheres Derived from Human Wharton's Jelly Mesenchymal Stem Cells for Spinal Cord Injury Regeneration in Rats

Spinal cord injury (SCI) causes inflammation and neuronal degeneration, resulting in functional movement loss. Since the availability of SCI treatments is still limited, stem cell therapy is an alternative clinical treatment for SCI and neurodegenerative disorders. Human umbilical cord Wharton's jelly-derived mesenchymal stem cells (hWJ-MSCs) are an excellent option for cell therapy. This study aimed to induce hWJ-MSCs into neural stem/progenitor cells in sphere formation (neurospheres) by using neurogenesis-enhancing small molecules (P7C3 and Isx9) and transplant to recover an SCI in a rat model. Inducted neurospheres were characterized by immunocytochemistry (ICC) and gene expression analysis. The best condition group was selected for transplantation. The results showed that the neurospheres induced by 10 µM Isx9 for 7 days produced neural stem/progenitor cell markers such as Nestin and β-tubulin 3 through the Wnt3A signaling pathway regulation markers (β-catenin and NeuroD1 gene expression). The neurospheres from the 7-day Isx9 group were selected to be transplanted into 9-day-old SCI rats. Eight weeks after transplantation, rats transplanted with the neurospheres could move normally, as shown by behavioral tests. MSCs and neurosphere cells were detected in the injured spinal cord tissue and produced neurotransmitter activity. Neurosphere-transplanted rats showed the lowest cavity size of the SCI tissue resulting from the injury recovery mechanism. In conclusion, hWJ-MSCs could differentiate into neurospheres using 10 µM Isx9 media through the Wnt3A signaling pathway. The locomotion and tissue recovery of the SCI rats with neurosphere transplantation were better than those without transplantation.

Mesenchymal stromal cells from human perinatal tissues: From biology to cell therapy

Cell-based regenerative medicine is of growing interest in biomedical research. The role of stem cells in this context is under intense scrutiny and may help to define principles of organ regeneration and develop innovative therapeutics for organ failure. Utilizing stem and progenitor cells for organ replacement has been conducted for many years when performing hematopoietic stem cell transplantation. Since the first successful transplantation of umbilical cord blood to treat hematological malignancies, non-hematopoietic stem and progenitor cell populations have recently been identified within umbilical cord blood and other perinatal and fetal tissues. A cell population entitled mesenchymal stromal cells (MSCs) emerged as one of the most intensely studied as it subsumes a variety of capacities: MSCs can differentiate into various subtypes of the mesodermal lineage, they secrete a large array of trophic factors suitable of recruiting endogenous repair processes and they are immunomodulatory.Focusing on perinatal tissues to isolate MSCs, we will discuss some of the challenges associated with these cell types concentrating on concepts of isolation and expansion, the comparison with cells derived from other tissue sources, regarding phenotype and differentiation capacity and finally their therapeutic potential.

In vivo study of HCV in mice with chimeric human livers

Estimates of hepatitis C virus infection include 170 million people worldwide, who face increased risk of development of cirrhosis, liver failure, and hepatocellular carcinoma. Standard of care therapy with pegylated interferon and ribavirin is effective in just half of patients, is challenged by substantial treatment-related morbidity, and is prohibitively expensive in most parts of the world. New therapeutics for treatment and prevention are clearly needed. Development of effective therapies has been significantly hampered by difficulties in establishing in vitro and in vivo models of viral replication. This chapter reviews development, validation, and early application of a mouse model with a chimeric human liver.

Mesenchymal stem cells from human umbilical cords ameliorate mouse hepatic injury in vivo

AIMS

To investigate human umbilical cord-derived mesenchymal stem cells (hUCMSCs) for use in the reversal of mouse hepatic injury.

METHODS

Human umbilical cord-derived mesenchymal stem cells, characterized by flow cytometry, were transplanted into carbon tetrachloride (CCl(4))-injured mice, and then followed for determination of localization and differentiation. Reverse transcriptase-polymerase chain reaction for the human 17alpha gene and fluorescence in situ hybridization analysis for the human X chromosome were used to locate exogenous hUCMSCs in mouse livers. Peripheral blood and liver specimens were collected at 7, 14 and 21 days after transplantation. For evaluating the recovery of injured liver tissues, serum aminotransferase was measured, and the pathological state of the hepatocytes was assessed.

RESULTS

The hUCMSCs were positive for the human MSC-specific markers CD13, CD29, CD44, CD105 and nerve growth factor receptor, but negative for the haematopoietic lineage markers CD31, CD34, CD38, CD45 and HLA-DR. Under conditions favouring differentiation in vivo, the expression of tryptophan 2,3-dioxygenase, human alpha-fetoprotein, cytokeratin 18, fibroblast secretory protein 1 and alpha-smooth-muscle-actin was detectable after hUCMSCs administration to mice subjected to liver injury. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP)-biotin nick end labelling and proliferating cell nuclear antigen staining showed that transplanted hUCMSCs could inhibit hepatocyte apoptosis and facilitate proliferation. Serum aminotransferases were decreased after transplantation of hUCMSCs into the injured mice, and hepatocyte denaturation was reduced.

CONCLUSIONS

Human umbilical cord-derived mesenchymal stem cells can enhance recovery of CCl(4)-injured mouse liver, providing evidence that such therapy could be useful for liver disorders or injury.

Mesenchymal stem cell-like cells derived from human gastric cancer tissues

Mesenchymal stem cells (MSCs) have been identified in and isolated from numerous human tissues. The characteristics of mesenchymal stem cells, including their plasticity, the secretion of cytokines, and their low immunogenicity, contribute to their therapeutic potential. It has recently been reported that MSCs are also involved in tumorigenesis and its prognosis. Here, we present the first report of MSC-like cells isolated from human gastric cancer tissues. In our study, gastric cancer-derived MSC-like cells (hGC-MSCs) were isolated from 13 out of 20 cancer tissue samples. Their characteristics, including their morphology, surface antigens, specific gene expression, and differentiation potential, were similar to those of MSCs derived from human bone marrow (hBM-MSCs) but different from gastric cancer cells. The existence of MSC-like cells in gastric cancer tissues suggests that they may be potential targets for cancer therapy and provides an experimental foundation for investigating their role in the initiation and progression of gastric cancers.

Stem cells for liver tissue repair: Current knowledge and perspectives

Stem cells from extra- or intrahepatic sources have been recently characterized and their usefulness for the generation of hepatocyte-like lineages has been demonstrated. Therefore, they are being increasingly considered for future applications in liver cell therapy. In that field, liver cell transplantation is currently regarded as a possible alternative to whole organ transplantation, while stem cells possess theoretical advantages on hepatocytes as they display higher in vitro culture performances and could be used in autologous transplant procedures. However, the current research on the hepatic fate of stem cells is still facing difficulties to demonstrate the acquisition of a full mature hepatocyte phenotype, both in vitro and in vivo. Furthermore, the lack of obvious demonstration of in vivo hepatocyte-like cell functionality remains associated to low repopulation rates obtained after current transplantation procedures. The present review focuses on the current knowledge of the stem cell potential for liver therapy. We discuss the characteristics of the principal cell candidates and the methods to demonstrate their hepatic potential in vitro and in vivo. We finally address the question of the future clinical applications of stem cells for liver tissue repair and the technical aspects that remain to be investigated.