Search

Abstract: Background and aim: Kupffer cells are intrasinusoidal space located macrophages with phagocytic capacity. Interferons are cytokines with antiviral, antiproliferative and immunomodulatory activities which may influence the activity of Kupffer cells. Aim of this study was to evaluate Kupffer cell gene expression after interferon-α or interferon-γ stimulation in order to investigate a link between these cytokines and macrophage activation. Methods: Rat Kupffer cells were cultured for 24h and divided into three groups: unstimulated; stimulated with interferon-α and stimulated with interferon-γ. After 8h stimulation total RNA was extracted and processed according to Affymetrix protocols and hybridised on R34A microarray gene set. Data analyses was performed using Microarray Analysis Suite 5.0 software. Genes showing remarkably different expression in microarray analysis were confirmed by real-time PCR. Results: Nearly 4000 out of the 8800 genes represented in the array were expressed by Kupffer cells. Among these, interferon-α up-regulates 91 genes by over two-fold (antiviral, antigen processing and presentation, and tumour suppressor/proapoptotic genes) and down-regulates 72 genes by 50% or more. Interferon-γ up-regulates 70 genes by over two-fold and down-regulates 78 genes by 50% or more. Most of the genes induced by interferon-α are also induced by interferon-γ. Down-regulated genes include growth factors and genes involved in cell cycle/proliferation. Real-time PCR confirms the results of the array. Conclusion: Interferons directly target rat Kupffer cells and are involved in the regulation of a wide variety of genes. Their expression profile shed light onto molecular mechanism of Kupffer cells activation in specific pathways such as antiviral and antitumour processes. [Copyright &y& Elsevier]

Abstract: Background and Aim: Tissue homeostasis and turnover require reserve stem proliferating cells. Several studies performed on immunodeficient animals have suggested a degree of plasticity by the hematopoietic stem cell compartment that may represent source for liver regeneration. We sought to explore the hepatic differentiation potential of hematopoietic stem cells from human cord blood, after toxic liver damage induced by allyl-alcohol in immunocompetent rats. Materials and Methods: Wistar rats were divided into groups (A) allyl-alcohol intraperitoneal injection with hematopoietic stem cell intraperitoneal infusion at 1 day and sacrifice 3 days later; (B) stem cell injection and sacrifice 3 days later; (C) allyl-alcohol infusion and sacrifice 4 days later; and (D) sacrifice without any treatment. Livers, spleens, and bone marrows were analysed for human stem cells using flow-cytometry; livers were also tested by histology and immunohistochemistry to study the pattern of hepatic regeneration after damage and human stem cell conversion into hepatocyte-like cells, respectively. Results: Flow-cytometry revealed selective recruitment of human hematopoietic stem cells by damaged livers (group A) compared with control group B. In addition, liver damage was reduced in animals treated with stem cells. Immunohistochemistry demonstrated that human stem cells could convert hepatic cells. Conclusions: Our study demonstrated that hematopoietic stem cells selectively recruited by injured livers can contribute to hepatic regeneration after acute toxic damage in immunocompetent recipients. [Copyright &y& Elsevier]

Abstract: Background and aim: Molecular adsorbent recycling system (MARS) treatment is able to remove both hydrosoluble and small- and medium-sized lipophilic toxins. MARS plays an important role in modifying liver failure complications, such as hepatorenal syndrome and hepatic encephalopathy. We sought to evaluate the clinical efficacy and safety of a MARS device in a consecutive series of hepatic failure patients. Materials: Twenty patients with acute liver failure, transplantation failure, or acute on chronic liver failure fulfilled the inclusion criteria of total bilirubin ≥10 mg/dL and at least one of the following: hepatic encephalopathy (HE) ≥II grade, hepatorenal syndrome (HRS) for chronic patients or total bilirubin ≥5 mg/dL and HE ≥I grade for acute patients. Results: MARS was able to reduce cholestatic parameters and improve neurologic status and renal function parameters in all treated patients. We also observed an improvement in the 3-month survival rate compared to the expected outcome in patients with MELD scores between 20 and 29, as well as 30 and 39. Conclusions: Based on these results, we confirm the safety and clinical efficacy of MARS treatment, with the best results in patients with MELD score of 20 to 29. Further studies are necessary to confirm whether this treatment is able to modify patient outcomes and prognosis. [Copyright &y& Elsevier]

Abstract: Background and aim: The clearance of plasma cytokines by means of albumin dialysis (MARS) has been demonstrated in various studies involving patients affected by either acute liver failure (ALF) or acute on chronic liver failure. The aim of the study was to measure the plasma levels of TNF-α, IL-6, and IL-1β in patients with ALF after each MARS treatment to evaluate the relationship between variations in cytokines levels and patient prognosis. Materials and methods: Ten patients with ALF undergoing several MARS treatments were enrolled (group 1). Blood samples were collected before and after each MARS treatment to measure TNF-α, IL-6, and IL-1β, and other hematochemical parameters. We also enrolled 10 patients with ALF who underwent standard therapy (group 2) as well as a control group of 10 healthy subjects matched for sex and age (group 3). Results: MARS reduced total bilirubin levels, biliary acids, BUN, ammonia, TNF-α, IL-6, and IL-1β (P < .05). Moreover, the reduction in inflammatory cytokines levels and improved prognosis were related. Conclusions: We confirmed the therapeutic efficacy of MARS treatment for ALF, which appeared to be related to removal of toxins and inflammatory cytokines determine that which patients prognosis. [Copyright &y& Elsevier]

Abstract: Among the different approaches for diabetes mellitus—pancreas and pancreatic islet transplantation—the use of stem cells represent a renewable alternative source of insulin-producing cells. Stem cells capable of differentiating into β-like cells can be isolated namely from embryonic cells, bone marrow, and umbilical cord blood, but also from adult organs such as pancreas, liver, and spleen. Several studies have demonstrated that by manipulating culture conditions and using growth and transcription factors of β-cell lineage (in particular pdx-1 and pax4), embryonic stem cells can differentiate in vitro after formation of embryoid bodies. Bone marrow stem cells can give rise to mesenchymal; endodermal-, and ectodermal-derived cells. In vivo it has been shown that after bone marrow transplantation, using a murine sex-mismatched model, insulin-producing cells expressing the Y chromosome can be detected in the donor pancreas, although not in a significantly number. Cells characterized by a group of markers (Nestin, CK-8, CK-18) and transcription factors (Isl-1, Pdx-1, Pax-4, Ngn-3) important for β-cell differentiation have been detected in umbilical cord blood. The recent evidence of the possibility to transdifferentiate stem cells to β cells encourages further studies in animal models to exhaustively determine the differentiation pathways of stem cells to insulin producing cells. These findings might open the way to a successful human investigation. [Copyright &y& Elsevier]