Contribution of neural crest and GLAST+ Wnt1+ bone marrow pericytes with liver fibrogenesis and/or regeneration.

BACKGROUND AND AIMS: Liver fibrosis results from cycles of liver damage and scar formation. We herein aimed at analysing neural crest cells and/or bone marrow stromal cells contribution to the liver. METHODS: Two liver fibrosis and one hepatectomy model were applied on double-transgenic loxP-Cre mouse lines. RESULTS: Increased numbers of glia with more complex processes were found in fibrotic livers. During embryonic development, only few cells were traced in the liver and bone marrow, in a minor fraction of mice of different neural crest reporter strains analysed: therefore, a neural crest origin of such cells is doubtful. In the fibrotic liver, a significantly higher incidence of endothelial cells and hepatocyte-like cells expressing the reporter gene Tomato were found in Wnt1-Cre-Tom and GLAST-CreERT2-Tom mice. Consistently, during early fibrogenesis stromal Wnt1-traced cells, with progenitor (CFU-F) properties, get likely mobilized to peripheral blood. Circulating adult Wnt1-traced cells are stromal cells and lack from the expression of other bone marrow and endothelial progenitor cells markers. Furthermore, in a 70% hepatectomy model GLAST+ Wnt1-traced pericytes were found to be mobilized from the bone marrow and the incidence of GLAST-traced hepatocyte-like cells was increased. Finally, GLAST-traced hepatocyte like-cells were found to maintain the expression of stromal markers. CONCLUSIONS: Our data suggest a gliosis process during liver fibrogenesis. While neural crest cells probably do not contribute with other liver cell types than glia, GLAST+ Wnt1-traced bone marrow pericytes are likely a source of endothelial and hepatocyte-like cells after liver injury and do not contribute to scarring.

Oligonucleotide IMT504 Improves Glucose Metabolism and Controls Immune Cell Mediators in Female Diabetic NOD Mice.

Type 1 diabetes occurs as a consequence of progressive autoimmune destruction of beta cells. A potential treatment for this disease should address the immune attack on beta cells and their preservation/regeneration. The objective of this study was to elucidate whether the immunomodulatory synthetic oligonucleotide IMT504 was able to ameliorate diabetes in NOD mice and to provide further understanding of its mechanism of action. We found that IMT504 restores glucose homeostasis in a diabetes mouse model similar to human type 1 diabetes, by regulating expression of immune modulatory factors and improving beta cell function. IMT504 treatment markedly improved fasting glycemia, insulinemia, and homeostatic model assessment of beta cell function (HOMA-Beta cell) index. Moreover, this treatment increased islet number and decreased apoptosis, insulitis, and CD45+ pancreas-infiltrating leukocytes. In a long-term treatment, we observed improvement of glucose metabolism up to 9 days after IMT504 cessation and increased survival after 15 days of the last IMT504 injection. We postulate that interleukin (IL)-12B (p40), possibly acting as a homodimer, and Galectin-3 (Gal-3) may function as mediators of this immunomodulatory action. Overall, these results validate the therapeutic activity of IMT504 as a promising drug for type 1 diabetes and suggest possible downstream mediators of its immunomodulatory effect.

A Tricin Derivative from Deschampsia antarctica Desv. Inhibits Colorectal Carcinoma Growth and Liver Metastasis through the Induction of a Specific Immune Response.

In colorectal carcinoma patients, distant metastatic disease is present at initial diagnosis in nearly 25% of them. The majority of patients with metastatic colorectal carcinoma have incurable disease; therefore, new therapies are needed. Agents derived from medicinal plants have already demonstrated therapeutic activities in human cancer cells. Antartina is an antitumor agent isolated from Deschampsia antarctica Desv. This study aimed to evaluate the antitumor properties of Antartina in colorectal carcinoma models. We used human and murine colorectal carcinoma cell lines for investigating proliferation, apoptosis, and cell-cycle effects of Antartina therapy in vitro Avatar and immunocompetent colorectal carcinoma animal models were applied for evaluating the effects of Antartina in vivo Immune response against colorectal carcinoma model was investigated using CTL assay, analyzing dendritic cell activation and intratumor T-cell subpopulation, and by tumor rechallenge experiments. Antartina inhibits in vitro human colorectal carcinoma cell proliferation; however, in vivo experiments in Avatar colorectal carcinoma model Antartina display a limited antitumor effect. In an immunocompetent colorectal carcinoma mice model, Antartina potently inhibited tumor growth and liver metastases, leading to complete tumor regressions in >30% of mice and increased animal survival. In addition, Antartina induced a potent specific cytotoxic T-cell response against colorectal carcinoma and a long-lasting antitumor immunity. Interestingly, Antartina increased tumor immunogenicity and stimulated dendritic cell activation. No toxic effects were observed at the doses employed. Our findings showed that Antartina has the ability to induce antitumor immunity against colorectal carcinoma and can be used to develop new tools for the treatment of colorectal carcinoma. Mol Cancer Ther; 17(5); 966-76. ©2018 AACR.

Involvement of hepatic macrophages in the antifibrotic effect of IGF-I-overexpressing mesenchymal stromal cells.

BACKGROUND: Cirrhosis is a major health problem worldwide and new therapies are needed. Hepatic macrophages (hMø) have a pivotal role in liver fibrosis, being able to act in both its promotion and its resolution. It is well-known that mesenchymal stromal cells (MSCs) can modulate the immune/inflammatory cells. However, the effects of MSCs over hMø in the context of liver fibrosis remain unclear. We previously described evidence of the antifibrotic effects of in vivo applying MSCs, which were enhanced by forced overexpression of insulin-like growth factor 1 (AdIGF-I-MSCs). The aim of this work was to analyze the effect of MSCs on hMø behavior in the context of liver fibrosis resolution. METHODS: Fibrosis was induced in BALB/c mice by chronic administration of thioacetamide (8 weeks). In vivo gene expression analyses, in vitro experiments using hMø isolated from the nonparenchymal liver cells fraction, and in vivo experiments with depletion of Mø were performed. RESULTS: One day after treatment, hMø from fibrotic livers of MSCs-treated animals showed reduced pro-inflammatory and pro-fibrogenic gene expression profiles. These shifts were more pronounced in AdIGF-I-MSCs condition. This group showed a significant upregulation in the expression of arginase-1 and a higher downregulation of iNOS expression thus suggesting decreased levels of oxidative stress. An upregulation in IGF-I and HGF expression was observed in hMø from AdIGF-I-MSCs-treated mice suggesting a restorative phenotype in these cells. Factors secreted by hMø, preconditioned with MSCs supernatant, caused a reduction in the expression levels of hepatic stellate cells pro-fibrogenic and activation markers. Interestingly, hMø depletion abrogated the therapeutic effect achieved with AdIGF-I-MSCs therapy. Expression profile analyses for cell cycle markers were performed on fibrotic livers after treatment with AdIGF-I-MSCs and showed a significant regulation in genes related to DNA synthesis and repair quality control, cell cycle progression, and DNA damage/cellular stress compatible with early induction of pro-regenerative and hepatoprotective mechanisms. Moreover, depletion of hMø abrogated such effects on the expression of the most highly regulated genes. CONCLUSIONS: Our results indicate that AdIGF-I-MSCs are able to induce a pro-fibrotic to resolutive phenotype shift on hepatic macrophages, which is a key early event driving liver fibrosis amelioration.