Antibodies and primary biliary cirrhosis - piecing together the jigsaw

Disturbing cytoskeleton by engineered nanomaterials for enhanced cancer therapeutics

Cytoskeleton plays a significant role in the shape change, migration, movement, adhesion, cytokinesis, and phagocytosis of tumor cells. In clinical practice, some anti-cancer drugs achieve cytoskeletal therapeutic effects by acting on different cytoskeletal protein components. However, in the absence of cell-specific targeting, unnecessary cytoskeletal recombination in organisms would be disastrous, which would also bring about severe side effects during anticancer process. Nanomedicine have been proven to be superior to some small molecule drugs in cancer treatment due to better stability and targeting, and lower side effects. Therefore, this review summarized the recent developments of various nanomaterials disturbing cytoskeleton for enhanced cancer therapeutics, including carbon, noble metals, metal oxides, black phosphorus, calcium, silicon, polymers, peptides, and metal-organic frameworks, etc. A comprehensive analysis of the characteristics of cytoskeleton therapy as well as the future prospects and challenges towards clinical application were also discussed. We aim to drive on this emerging topic through refreshing perspectives based on our own work and what we have also learnt from others. This review will help researchers quickly understand relevant cytoskeletal therapeutic information to further advance the development of cancer nanomedicine.

Evolving liver inflammation in biochemically normal individuals with anti-mitochondria antibodies

Background

Anti-mitochondria autoantibodies (AMA) occur in > 95% primary biliary cholangitis (PBC) patients. Biochemically normal AMA-positive (BN/AMA+) individuals, occasionally noticed by indirect immunofluorescence (IIF) on HEp-2 cells and confirmed in AMA-specific assays, may represent early stages of PBC. The Enhanced Liver Fibrosis (ELF) score is a surrogate marker for liver fibrosis. This prospective study investigated the ELF score in BN/AMA+ individuals and PBC patients, considering autoantibody avidity and serum levels along the years.

Methods

327 samples from 35 PBC and 59 BN/AMA+ were prospectively obtained in average 3.83 (range 0.50-7.40) years apart. Samples were tested by IIF on rat-kidney (IIF-AMA), western-blot for AMA (WB-AMA), and ELISA for antibodies against pyruvate-dehydrogenase (PDC-E2), gp210, sp100 and CENP-A/B. Anti-PDC-E2 avidity was determined by 6 M urea-elution ELISA. Alkaline phosphatase (ALP), gamma glutamyl transferase (ɣGT) and ELF score were measured by automated methods.

Results

Along the follow-up period BN/AMA+ subjects and PBC patients presented significant increase in serum anti-PDC-E2 (mean 10.45% and 8.86% per year; respectively), anti-PDC-E2 avidity (3.02% and 4.94%/year) and ELF score (3.24% and 2.71%/year). IIF-AMA and ɣGT increased in BN/AMA+ (6.59% and 2.36%) and decreased in PBC (- 4.89%/year and - 3.88%/year). In BN/AMA+ individuals there was positive correlation of ELF with IIF-AMA titer (r = 0.465; p < 0.001) and with anti-PDC-E2 levels (r = 0.239; p < 0.001). Expansion of autoantibody targets along time occurred in 39% BN/AMA+ and 49% PBC patients. The frequency of BN/AMA+ with high probability of having established PBC increased from 7 to 14%.

Conclusions

BN/AMA+ individuals present an orchestrated increase in ELF score and humoral autoimmune response over time, indicating an opportunity for early therapeutic intervention and prevention in autoimmunity.

Pathophysiology of cholangiopathies

The diseases of the intrahepatic biliary tree are a large group of potentially evolutive congenital and acquired liver disorders affecting both the adult and pediatric populations. They represent a relevant cause of liver-related morbidity and mortality and an important indication for liver transplantation, particularly in children. While the practical approach to patients affected by biliary tree diseases has not significantly changed yet, the conceptual approach to the pathophysiology of cholangiopathies has witnessed important advances that will be discussed. The primary cell target of the pathogenetic sequence of these disorders is the biliary epithelium. Cholangiocytes have multifaceted functions, not limited to bile production. Their capability to secrete a range of different pro-inflammatory mediators, cytokines, and chemokines indicates a major role of cholangiocytes in the inflammatory reaction. Furthermore, paracrine secretion of growth factors and peptides mediates an extensive cross-talk with other liver cell types, including hepatocytes, stellate, and endothelial and inflammatory cells. Cholangiopathies share a number of pathogenetic mechanisms, including inflammation, cholestasis, fibrosis, apoptosis, altered development, and neoplastic transformation. These basic disease mechanisms will be discussed in detail, along with the distinct features of a number of cholangiopathies. Furthermore, an increase in the biliary cell compartment is a common response to many forms of liver injury, from cholangiopathies to viral and fulminant hepatitis. Elucidation of these pathophysiologic mechanisms will likely provide clues for future therapeutic strategies. Furthermore, understanding the role of cholangiocytes in liver regeneration/repair and the mechanisms of cholangiocyte activation and their relationship with liver progenitor cell will be of further interest.

Epitopes of calreticulin recognised by IgA autoantibodies from patients with hepatic and coeliac disease

Calreticulin (CRT) was identified as a frequent target of serum autoantibodies (Ab) in various diseases, but anti-CRT Ab of IgA isotype were described only in coeliac (CLD) and some hepatic diseases. Employing ELISA with recombinant CRT we found significantly higher (P<0.001) levels of IgA anti-CRT Ab in sera of patients with primary biliary cirrhosis (PBC) (77.6+/-8.9 AU/mean+/-SE), autoimmune hepatitis (AIH) (105.1+/-9.2 AU) and alcoholic liver cirrhosis (ALC) (193.5+/-21.0 AU) relative to healthy controls (38.6+/-2.0 AU). The levels of IgG anti-CRT Ab in sera of patients with PBC (59.5+/-3.4 AU), AIH (89.7+/-7.9 AU) and ALC (86.4+/-6.2 AU) were also significantly increased (P<0.001) when compared with controls (38.5+/-2.1 AU). Pepscan technique with decapeptides of CRT (each overlapping by eight amino acids) revealed antigenic epitopes of this molecule recognised by IgA Ab of almost all tested patients-KGKNVLINKD and QVKSGTIFDNFL. We also identified disease specific antigenic epitopes on CRT molecule, predominantly recognised by IgA Ab of patients suffering from a particular disease: GGYVKLFPNS and YVKLFPNSLD in AIH (83%, 92% of patients), GLQTSQDARF and EQRLKEEEED in CLD (both 75%) and ASKPEDWDER in ALC (67%). Identification of disease specific CRT epitopes contributes to clarification of autoreactivity against this molecule.

Tissue Engineering of Human Biliary Epithelial Cells on Polyglycolic Acid/Polycaprolactone Scaffolds Maintains Long-Term Phenotypic Stability

The biliary tree is the target of damage in a number of important liver diseases. Although human biliary epithelial cells (hBECs) can be maintained in vitro for up to 8 weeks, using double-collagen gels, which offer a substantial improvement compared with conventional tissue culture plastic, such gels are unstable and, being only semisolid, they do not lend themselves readily to routine analysis. In this study we have investigated the behavior of primary hBECs on polyglycolic acid (PGA) fiber mesh scaffolds. Experiments showed that PGA fiber mesh scaffolds collapsed after 3 or 4 weeks; hence, in order to improve the integrity of the construct, we also developed a polycaprolactone (PCL)-stabilized PGA scaffold. Cells formed spheroidal aggregates while continuing to proliferate long term and expressing phenotypic stability. Aggregates spontaneously detached from the fibers and could either be left to attach to tissue culture plastic, after which cells spread out and continued to proliferate, or they could be reseeded onto fresh constructs, which then became recolonized and the same pattern of tissue formation was repeated. This behavior was observed even after 6 months and is of major significance because this culture model could therefore be used as a longterm strategy for growing, expanding, and exploiting hBECs for subsequent studies of bile duct morphogenesis and tissue engineering of artificial bile ducts.

Hepatobiliary pathology

Insights provided by molecular biology, immunohistochemistry, and transmission electron microscopy have increased our understanding of the pathogenesis and histopathology of hepatitis C virus (HCV) infection, nonalcoholic steatohepatitis (NASH), and bile ductular proliferative reactions in a number of liver diseases. Human and chimpanzee liver infected with HCV showed viral-like particles (50 to 60 nm in diameter) as well as aggregates of short tubules that represent viral envelope material. Interactions of HCV core protein with apolipoproteins have a role in the pathogenesis of HCV-related steatosis. Pathologists should be aware of the spectrum of liver pathology described with the use of highly active antiretroviral therapy (HAART) agents for the human immunodeficiency virus infection, which includes microvesicular steatosis and more severe hepatic injury with confluent necrosis. Proliferation of bile ductular structures is influenced by specific molecules and proteins (eg, the mucin-associated trefoil proteins and estrogens). The interplay between Notch receptors and Jagged 1 protein, as expressed by many cells of the liver (including bile duct epithelium) varies in primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC). Cholangiocarcinoma does not appear to be a long-term complication of small duct PSC. The fatty liver diseases, both alcoholic and nonalcoholic, are characterized by production of reactive oxygen species that have detrimental effects such as opening mitochondrial permeability transition pores with resultant release of cytochrome c into the cytosol. Hepatocellular carcinoma is now a recognized late complication of NASH. The derivation of hepatic stem cells, the roles of HFE protein and other hepatic and intestinal transport proteins in hemochromatosis, and the histopathologic interpretive challenge of centrilobular lesions in posttransplant liver biopsies are among other recent studies considered in this review.

Cholestatic syndromes

Further insights into the cellular and molecular mechanisms underlying hepatobiliary transport function and its regulation now permit a better understanding of the pathogenesis and treatment options of cholestatic liver diseases. Identification of the molecular basis of hereditary cholestatic syndromes will result in an improved diagnosis and management of these conditions. New insights into the pathogenesis of extrahepatic manifestations of cholestasis (eg, pruritus) have facilitated new treatment strategies. Important new studies have been published about the pathogenesis, clinical features, diagnosis, and treatment of primary biliary cirrhosis, primary sclerosing cholangitis, cholestasis of pregnancy, total parenteral nutrition-induced cholestasis, drug-induced cholestasis, and viral cholestatic syndromes.