Immunohistochemical and immunochemical study of amyloid in liver affected by systemic Alambda amyloidosis with antibodies against three different regions of immunoglobulin lambda light chain

Mass spectrometry-based absolute quantification of amyloid proteins in pathology tissue specimens: Merits and limitations

To clarify the significance of quantitative analyses of amyloid proteins in clinical practice and in research relating to systemic amyloidoses, we applied mass spectrometry-based quantification by isotope-labeled cell-free products (MS-QBIC) to formalin-fixed, paraffin-embedded (FFPE) tissues. The technique was applied to amyloid tissues collected by laser microdissection of Congo red-stained lesions of FFPE specimens. Twelve of 13 amyloid precursor proteins were successfully quantified, including serum amyloid A (SAA), transthyretin (TTR), immunoglobulin kappa light chain (IGK), immunoglobulin lambda light chain (IGL), beta-2-microglobulin (B2M), apolipoprotein (Apo) A1, Apo A4, Apo E, lysozyme, Apo A2, gelsolin, and fibrinogen alpha chain; leukocyte cell-derived chemotaxin-2 was not detected. The quantification of SAA, TTR, IGK, IGL, and B2M confirmed the responsible proteins, even when the immunohistochemical results were not decisive. Considerable amounts of Apo A1, Apo A4, and Apo E were deposited in parallel amounts with the responsible proteins. Quantification of amyloid protein by MS-QBIC is feasible and useful for the classification of and research on systemic amyloidoses.

Primary hepatic amyloidosis: A case report and review of literature

We describe a case of 42-year-old female presenting with abdominal pain associated with loss of weight and fever for 8 mo. On evaluation she had gross hepatomegaly with raised alkaline phosphatase and raised GGT levels with normal transaminases and bilirubin. On imaging she had diffuse enlargement of liver with heterogeneous contrast uptake in liver. Her viral marker and autoimmune markers were negative. Liver biopsy depicted massive deposition of amyloid in peri-sinusoidal spaces which revealed apple green birefringence on polarizing microscopy after Congo red staining. Cardiac and renal evaluation was unremarkable. Abdominal fat pad and rectum biopsy was negative for amyloid deposit. There was no evidence of primary amyloidosis as bone marrow examination was normal. Serum and urine immunofixation electrophoresis were normal. Immunoperoxidase staining for serum amyloid associated protein for secondary amyloidosis was negative from liver biopsy. We present this rare case of primary hepatic amyloidosis and review the literature regarding varied presentations of hepatic involvement in amyloidosis.

Proteomic analysis of proteins expressing in regions of rat brain by a combination of SDS-PAGE with nano-liquid chromatography-quadrupole-time of flight tandem mass spectrometry

BACKGROUND

Most biological functions controlled by the brain and their related disorders are closely associated with activation in specific regions of the brain. Neuroproteomics has been applied to the analysis of whole brain, and the general pattern of protein expression in all regions has been elucidated. However, the comprehensive proteome of each brain region remains unclear.

RESULTS

In this study, we carried out comparative proteomics of six regions of the adult rat brain: thalamus, hippocampus, frontal cortex, parietal cortex, occipital cortex, and amygdala using semi-quantitative analysis by Mascot Score of the identified proteins. In order to identify efficiently the proteins that are present in the brain, the proteins were separated by a combination of SDS-PAGE on a C18 column-equipped nano-liquid chromatograph, and analyzed by quadrupole-time of flight-tandem-mass spectrometry. The proteomic data show 2,909 peptides in the rat brain, with more than 200 identified as region-abundant proteins by semi-quantitative analysis. The regions containing the identified proteins are membrane (20.0%), cytoplasm (19.5%), mitochondrion (17.1%), cytoskeleton (8.2%), nucleus (4.7%), extracellular region (3.3%), and other (18.0%). Of the identified proteins, the expressions of glial fibrillary acidic protein, GABA transporter 3, Septin 5, heat shock protein 90, synaptotagmin, heat shock protein 70, and pyruvate kinase were confirmed by immunoblotting. We examined the distributions in rat brain of GABA transporter 3, glial fibrillary acidic protein, and heat shock protein 70 by immunohistochemistry, and found that the proteins are localized around the regions observed by proteomic analysis and immunoblotting. IPA analysis indicates that pathways closely related to the biological functions of each region may be activated in rat brain.

CONCLUSIONS

These observations indicate that proteomics in each region of adult rat brain may provide a novel way to elucidate biological actions associated with the activation of regions of the brain.

[Amyloidosis in liver biopsies]

INTRODUCTION

We reassessed the histopathology and origin of amyloid in liver biopsies.

MATERIALS AND METHODS

All liver biopsies were retrieved from a series of 588 cases with histologically confirmed amyloidosis submitted between February 2006 and January 2009 to the Amyloid Registry of the Charité University Hospital. Liver biopsies had been fixed in formalin and embedded in paraffin. 3-5 microm thick paraffin sections were stained with hematoxylin and eosin and Congo red. Amyloid was classified immunohistochemically, using antibodies directed against amyloid P-component, AA amyloid, apolipoprotein AI, fibrinogen, lysozyme, lambda- and kappa-light chain, and transthyretin.

RESULTS

Amyloid was found in 46 liver biopsies (29 men, 17 women; mean age 60 years, range 34-87 years). Immunohistochemical classification succeeded in 42 cases. AL amyloidosis was present in 40 (87%) cases and was further categorized into AL amyloid of lambda-light chain origin in 26 (57%) cases, and kappa-light chain origin in 14 (30%) cases. ATTR and AA amyloidosis were found in a single patient each (2%). In 4 (9%) cases, amyloid remained unclassified.

CONCLUSIONS

Hepatic amyloidosis is most commonly AL amyloid of lambda- and kappa-light chain origin and is often associated with marked parenchymal atrophy.

Parkin deletion causes cerebral and systemic amyloidosis in human mutated tau over-expressing mice

Deposition of proteins leading to amyloid takes place in some neurodegenerative diseases such as Alzheimer's disease and Huntington's disease. Mutations of tau and parkin proteins produce neurofibrillary abnormalities without deposition of amyloid. Here we report that mature, parkin null, over-expressing human mutated tau (PK(-/-)/Tau(VLW)) mice have altered behaviour and dopamine neurotransmission, tau pathology in brain and amyloid deposition in brain and peripheral organs. PK(-/-)/Tau(VLW) mice have abnormal behaviour and severe drop out of dopamine neurons in the ventral midbrain, up to 70%, at 12 months and abundant phosphorylated tau positive neuritic plaques, neuro-fibrillary tangles, astrogliosis, microgliosis and plaques of murine beta-amyloid in the hippocampus. PK(-/-)/Tau(VLW) mice have organomegaly of the liver, spleen and kidneys. The electron microscopy of the liver confirmed the presence of a fibrillary protein deposits with amyloid characteristics. There is also accumulation of mouse tau in hepatocytes. These mice have lower levels of CHIP-HSP70, involved in the proteosomal degradation of tau, increased oxidative stress, measured as depletion of glutathione which, added to lack of parkin, could trigger tau accumulation and amyloidogenesis. This model is the first that demonstrates beta-amyloid deposits caused by over-expression of tau and without modification of the amyloid precursor protein, presenilins or secretases. PK(-/-)/Tau(VLW) mice provide a link between the two proteins more important for the pathogenesis of Alzheimer disease.