griseofulvin and Liver-Cirrhosis--Alcoholic

Mallory bodies are a morphological key feature of severe alcoholic liver cell injury (alcoholic hepatitis) and the morphological expression of dysregulation and derangement of the intermediate filament cytoskeleton of the hepatocyte. Their pathogenesis is still unclear. Studies on Mallory body formation may not only help to elucidate the mechanisms of liver cell injury associated with alcoholic hepatitis, but may also contribute to our understanding of the regulation and function of the intermediate filament cytoskeleton.

Topics: Animals; Chemical and Drug Induced Liver Injury; Colchicine; Cytoskeleton; Electrophoresis, Polyacrylamide Gel; Endoplasmic Reticulum; Fluorescent Antibody Technique; Griseofulvin; Hepatitis, Alcoholic; Humans; Isoantibodies; Isoelectric Focusing; Keratins; Liver; Liver Cirrhosis, Alcoholic; Mice; Microscopy, Electron; Rats

To study the molecular structure of Mallory body (MB) proteins we applied infrared spectroscopy of the isolated MBs from livers obtained from autopsied patients with alcoholic cirrhosis and griseofulvin-fed (GF-fed) mice. Liver frozen sections were extracted with detergent and digested with deoxyribo- and ribonuclease and collagenase. MB-enriched fractions were then separated out using the aqueous two-phase polymer system. Immunohistochemical and electron microscopic examination showed that the MB composition was virtually identical in human and mouse livers. Infrared spectra of both MB samples showed that the MBs had more numerous and stronger intermolecular hydrogen bonding than did the background control fractions as well as the cytoskeletal fraction from control and GF-fed mice. This may explain why the proteins in MBs are aggregated. The relative amount of beta-sheets was increased compared to the alpha-helices in the MBs, indicating that conformational changes in the cytokeratin peptides of the MBs had occurred. This may explain why the antigenic sites observed in MB proteins show changes in affinity for antibodies to cytokeratins as observed by immunohistochemical staining of MBs.

Topics: Animals; Chemical and Drug Induced Liver Injury; Cytoskeletal Proteins; Griseofulvin; Humans; Inclusion Bodies; Liver; Liver Cirrhosis, Alcoholic; Liver Diseases; Male; Mice; Mice, Inbred C3H; Protein Conformation; Proteins; Spectrophotometry, Infrared

Topics: Animals; Cytoskeleton; Griseofulvin; Humans; Liver; Liver Cirrhosis, Alcoholic; Liver Diseases; Mice; Rats; Staining and Labeling

Antibodies raised against prekeratin intensely and specifically stain, in immunofluorescence microscopy, Mallory bodies ("alcoholic hyalin") present in livers of human alcoholics and griseofulyin-treated mice. The high sensitivity of this method allows the identification of small distinct cytoplasmic structures that are observed during early stages of Mallory body formation, especially frequent in the perinuclear cytoplasm, as well as during stages of Mallory body disintegration and disappearance, such as after withdrawal of the drug. In the latter situation, the prekeratin-containing small particles exhibit a characteristic pattern of arrangement in the hepatocyte periphery. Electron microscopy illustrates that such small bodies are heap-like aggregates of typical Mallory body filaments. Immunofluorescence studies with antibodies to isolated prekeratin polypeptides from bovine hoof or muzzle epidermis show that Mallory body filaments, in particular those in human liver, are immunologically more closely related to prekeratin of tonofilaments from living epidermal cells (stratum spinosum). The data indicate that Mallory bodies contain a pathologic form of prekeratin-like material. They also suggest that disorders of cytoskeletal structures of the intermediate-sized filament class are associated with specific diseases and can be visualized and characterized by immunofluorescence microscopy by using antibodies to constitutive proteins of such filaments.

Topics: Animals; Cytoplasmic Granules; Fluorescent Antibody Technique; Griseofulvin; Hepatitis, Alcoholic; Humans; Keratins; Liver Cirrhosis, Alcoholic; Liver Cirrhosis, Experimental; Mice; Protein Precursors