34 research outputs found
In Situ Chemical Composition Analysis of Cirrhosis by Combining Synchrotron Fourier Transform Infrared and Synchrotron X‑ray Fluorescence Microspectroscopies on the Same Tissue Section
Liver is subject to various chronic pathologies, progressively
leading to cirrhosis, which is associated with an increased risk of
hepatocellular carcinoma. There is an urgent need for diagnostic and
prognostic markers of chronic liver diseases and liver cancer. Spectroscopy-based
approaches can provide an overview of the chemical composition of
a tissue sample offering the possibility of investigating in depth
the subtle chemical changes associated with pathological states. In
this study, we have addressed the composition of cirrhotic liver tissue
by combining synchrotron Fourier transform infrared (FTIR) microspectroscopy
and synchrotron micro-X-ray fluorescence (XRF) on the same tissue
section using a single sample holder in copper. This allowed investigation
of the in situ biochemical as well as elemental composition of cells
and tissues at high spatial resolution. Cirrhosis is characterized
by regeneration nodules surrounded by annular fibrosis. Hepatocytes
within cirrhotic nodules were characterized by high content in esters
and sugars as well as in phosphorus and iron compared with fibrotic
septa. A high heterogeneity was observed between cirrhotic nodules
in their content in sugars and iron. On fibrosis, synchrotron XRF
revealed enrichment in calcium compared to cirrhotic hepatocytes.
Careful scrutiny of tissue sections led to detection of the presence
of microcrystals that were demonstrated as precipitates of calcite
using synchrotron FTIR. These results demonstrated that synchrotron
FTIR and synchrotron XRF microspectroscopies provide complementary
information on the chemical composition of cirrhotic hepatocytes and
fibrotic septa in cirrhosis
Second derivatives of IR spectra.
<p>Spectra recorded on steatosis or non-steatotic hepatocytes were superimposed (upper panel). Second derivatives of the spectra were calculated and superimposed in the frequency domain 2600–3200 cm<sup>−1</sup> (lower panel).</p
Assignment of frequency to chemical functions.
<p>From <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0007408#pone.0007408-Dreissig1" target="_blank">[19]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0007408#pone.0007408-Banyay1" target="_blank">[20]</a>.</p
Histological features of steatosis.
<p>Tissue sections of 6 µm thickness were performed on paraffin embedded biopsies from normal liver or from fatty liver and stained with HES (hematoxylin, eosin and safran). Normal hepatic lobule without steatosis (left panel) or fatty liver area exhibiting macrovacuolar and microvesicular steatosis (right panel) are shown. Upper panel: ×100, lower panel: ×400. PT: portal tract, BD: biliary duct, PV: portal vein, HA: hepatic artery, CLV: centrilobular vein, SV: steatotic vacuole.</p
Spectroscopic analysis of non-steatotic hepatocytes on fatty liver.
<p>Spectroscopic analyses were performed on periportal hepatocytes on tissue section from normal or fatty liver. The video image is shown (left panel) with the corresponding averaged IR spectra (right panel) and the chemical imaging of the sum of DAG (middle panel).</p
Analysis of steatosis using synchrotron FTIR microspectroscopy.
<p>A) Optical image of steatotic hepatocytes containing steatotic vesicles (white star) and non-steatotic hepatocytes (black star). B) Averaged IR spectra recorded inside steatotic vesicles (upper spectrum in blue) or on non-steatotic hepatocytes (lower spectrum in red). The band corresponding to olefin (3000–3060 cm<sup>−1</sup>) is labelled by a black arrow. C) Chemical imaging of some bands on the tissue section.</p
MOESM5 of Autoantibody signatures defined by serological proteome analysis in sera from patients with cholangiocarcinoma
Additional file 5: Figure S1. Anti-actin and anti-vimentin evaluation using immunofluorescence on colchicine-treated Hep2 cells. Sera positive by MS for anti-actin or anti-vimentin autoantibodies were tested by indirect immunofluorescence; (A) typical pattern of actin-cable strongly stained by anti-actin antibody; (B) typical pattern given by anti-vimentin antibody, vimentin colchicine-treated collapses into perinuclear coils
MOESM3 of Autoantibody signatures defined by serological proteome analysis in sera from patients with cholangiocarcinoma
Additional file 3: Table S3. Gene Ontology distribution of proteins recognized by CC sera, according to the protein class
The Reg3α (HIP/PAP) Lectin Suppresses Extracellular Oxidative Stress in a Murine Model of Acute Liver Failure
<div><p>Background and Aims</p><p>Acute liver failure (ALF) is a rapidly progressive heterogeneous illness with high mortality rate and no widely accessible cure. A promising drug candidate according to previous preclinical studies is the Reg3α (or HIP/PAP) lectin, which alleviates ALF through its free-radical scavenging activity. Here we study the therapeutic targets of Reg3α in order to gain information on the nature of the oxidative stress associated with ALF.</p><p>Methods</p><p>Primary hepatocytes stressed with the reactive oxygen species (ROS) inducers TNFα and H<sub>2</sub>O<sub>2</sub> were incubated with a recombinant Reg3α protein. ALF was induced in C57BL/6J mice by an anti-CD95 antibody. Livers and primary hepatocytes were harvested for deoxycholate separation of cellular and extracellular fractions, immunostaining, immunoprecipitation and malondialdehyde assays. Fibrin deposition was studied by immunofluorescence in frozen liver explants from patients with ALF.</p><p>Results</p><p>Fibrin deposition occurs during experimental and clinical acute liver injuries. Reg3α bound the resulting transient fibrin network, accumulated in the inflammatory extracellular matrix (ECM), greatly reduced extracellular ROS levels, and improved cell viability. Hepatocyte treatment with ligands of death receptors, e.g. TNFα and Fas, resulted in a twofold increase of malondialdehyde (MDA) level in the deoxycholate-insoluble fractions. Reg3α treatment maintained MDA at a level similar to control cells and thereby increased hepatocyte survival by 35%. No antioxidant effect of Reg3α was noted in the deoxycholate-soluble fractions. Preventing fibrin network formation with heparin suppressed the prosurvival effect of Reg3α.</p><p>Conclusions</p><p>Reg3α is an ECM-targeted ROS scavenger that binds the fibrin scaffold resulting from hepatocyte death during ALF. ECM alteration is an important pathogenic factor of ALF and a relevant target for pharmacotherapy.</p></div