Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0034067 (emphysema)
 11,506 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two unreleated adult males were found to be suffering from an association of pan-lobular severe emphysema and hepatomegally of unknown origin which led to the discovery of a marked deficit in alpha-1 antitrypsin (A1-AT) in relation to a PiZ phenotype. Liver biopsy revealed cirrhosis with portal fibrosis in one case and in both cases fatty infiltration with the accumulation of a glycoprotein antigenically identical to A1-AT. Electron microscopy showed this protein to be situated within the dilated lumina of the endoplasmic reticulum of the hepatocytes. A1-AT deficiency is usually associated with pulmonary involvement only in the adult and liver involvement only in the child. The association of the two remains rare--hence the interest of the two cases reported.
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PMID:[Pulmonary emphysema and hepatic involvement by alpha-1 antitrypsin deficiency in two adults with a PiZ phenotype (author's transl)]. 30 25

Following exposure to an aerosol of 0.1 per cent. (0.005M) cadmium chloride in physiologic saline, rat lungs were examined at 1 hour, 1, 2, 3, 4, 5, 7, 10 and 21 days. Light microscopy showed that damage was most marked about respiratory bronchioles with a prominent increase in interstitial cells. Up to 3 days the intestitial cells were closely packed and monocytic in type, but on the fourth and fifth days, the cellular density had decreased and elongated cells resembling fibroblasts appeared. By 7 days the interstitial cells were predominantly fibroblastic. Ultrastructurally the fibroblasts were active with prominent rough endoplasmic reticulum and numerous, single, haphazardly scattered collagen fibrils in lacunae at the cell margins. At 21 days after injury, interstitial collagen was seen as well organised, mature bundles. The fibrosis was seen in a peribronchiolar position with distoration of the bronchiole and adjacent alveoli. We suggest that the peribronchiolar localisation of fibrosis is the probable cause of centriacinar emphysema resulting from acute cadmium fume poisoning in man.
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PMID:Peribronchiolar fibrosis following acute experimental lung damage by cadmium aerosol. 51 43

Male golden hamsters were exposed to a solution of purified pancreatic elastase by intratracheal injection. They developed panlobular (panacinar) emphysema and, in addition, were found to show severe goblet cell metaplasia in the major bronchi. The metaplastic change in the respiratory epithelium was associated with persistence of a fenestrated sheet of mucus, widely present throughout the bronchial tree, which was greater in amount than that in either unexposed or saline exposed controls. Transmission electron micrography showed a striking increase in size of individual goblet cells, due to increased numbers of secretory droplets which were also much larger and paler than in control bronchi. Ciliated cells appeared smaller than normal due to compression by the swollen goblet cells. The presence of prominent dilatation of the endoplasmic reticulum and the increased frequency of secretory droplet release from the luminal surface stronly suggest that the goblet cell changes were due to increased formation and secretion of mucus into the damaged bronchi. These experiments show that a single exposure to elastase produces both severe panlobular emphysema and goblet cell metaplasia. The changes resemble several of the anatomic features of chronic obstructive lung disease in man for which this injury may be a suitable model.
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PMID:Bronchial mucus hypersecretion induced by elastase in hamsters: ultrastructural appearances. 72 88

Extremely deficient levels of alpha-1-antitrypsin (ALPHA1AT) predispose such deficient individuals to the development of emphysema and cirrhosis. Protease inhibitor (Pi) typing has clarified that the inherited deficiency is codominant. A glycoprotein with antigenic characteristics of alpha1AT is found in the endoplasmic reticulum of the hepatocytes of individuals with PiZ phenotype. No therapy is available except liver transplantation. Although biochemical advances in defining the nature of alpha1AT deficiency are progressing, the pathogenesis of the liver disease remains an enigma.
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PMID:The current status of alpha-1-antityrpsin, a protease inhibitor, in gastrointestinal disease. 76 97

Ruminal administration of 3-methylindole in goats severe pulmonary edema and respiratory distress. Electron microscopic studies of lungs reveal extensive degeneration and necrosis of alveolar membranous pneumocytes and bronchiolar epithelium. The necrosis of the pneumocytes is followed by proliferation of granular pneumocytes, which repopulate the alveolar basal lamina scaffold. 3-Methylindole may also induce proliferation of smooth endoplasmic reticulum in the remaining membranous pneumocytes and nonciliated columnar cells, indicating that these two cell types are involved in the xenobiotic function of the lung. The results suggest that 3-methylindole in cigarette smoke may play an important role in the pathogenesis of small airway disease and emphysema, and that patients with severe liver diseases or portocaval shunt may be predisposed to diffuse alveolar damage by 3-methylindole produced in the intestinal tract.
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PMID:3-methylindole-induced pulmonary injury in goats. 86 17

The author reviews the early history of alpha 1-antitrypsin (AAT) deficiency; the biochemical characterization of this inborn error of metabolism, its pattern of inheritance, frequency and predisposition to early, panacinar emphysema. The importance of the destructive element in emphysema and the gradual focusing on neutrophil elastase as a key enzyme in the pathogenesis of emphysema in alpha 1-antitrypsin deficiency is emphasized. The deficiency state as a prototype of an endoplasmic reticulum storage disease is discussed.
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PMID:Discovery of alpha 1-antitrypsin deficiency. 211 60

Alpha-1-antitrypsin (AAT) is the predominant protease inhibitor in human sera. The major physiological role of this inhibitor is to protect elastin fibers in the alveolar structure of the lung from excessive degradation by neutrophil elastase. AAT is synthesized predominantly by hepatocytes, although the AAT gene is expressed to a small degree in the epithelial cells of various tissues. Recent studies have shown that the enhanced liver-specific expression of the AAT gene is controlled by the binding of hepatic nuclear proteins to specific DNA sequences upstream from the structural gene. A variety of mutations within the AAT gene have been identified that result in a partial deficiency or total absence of the inhibitor in sera. Inheritance of a particular combination of these alleles can result in a predisposition towards the development of destructive lung disease. Interestingly, the most common AAT deficiency variant, designated PiZ, causes the mutant protein to accumulate as an insoluble aggregate within the lumen of the hepatic rough endoplasmic reticulum, which is an etiological agent for the development of liver disease. Overall, investigation into the genetic control of AAT has led to an increased understanding of the factors that control hepatic gene expression, as well as mechanisms involved in the pathophysiology of emphysema and liver cirrhosis.
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PMID:Genetic control of human alpha-1-antitrypsin. 269 88

Circulating alpha 1-antitrypsin is synthesized primarily in the liver and secreted into the bloodstream, where it serves as the major protease inhibitor. The PiZ variant of alpha 1-antitrypsin is associated with decreased levels of the protein in sera as a result of its retention within hepatocytes. Homozygosity for the variant allele predisposes individuals to the development of pulmonary emphysema and an increased risk for liver disease. We and others have previously demonstrated that the normal PiM human alpha 1-antitrypsin gene can be properly expressed in the livers of transgenic mice. The PiZ variant of the human alpha 1-antitrypsin gene was introduced into the germline of mice to determine whether the mutant protein would accumulate in mouse hepatocytes and if such accumulation would result in the development of liver damage in an animal model. As expected, the mutant human protein was abundantly synthesized in the livers of the transgenic animals and accumulated within the rough endoplasmic reticulum of hepatocytes as it does in human patients. PiZ mice developed significantly more liver necrosis and inflammation than PiM transgenic mice or control littermates. The degree of liver damage was correlated with the amount of PiZ alpha 1-antitrypsin accumulated in the liver of the different pedigrees of mice. Although 40% of PiZ mice tested were seropositive for mouse hepatitis virus (MHV), the degree of liver damage was not influenced by the MHV seropositivity; rather, it was related only to the presence of accumulated PiZ protein.
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PMID:Accumulation of PiZ alpha 1-antitrypsin causes liver damage in transgenic mice. 278 98

Alpha 1-Antitrypsin (alpha 1AT) deficiency is characterized by reduced serum levels of alpha 1AT and a risk for the development of emphysema and liver disease. However, whereas there is an increased risk for emphysema associated with at least 10 alpha 1AT deficiency and null alleles, the hepatic disease is observed only in a subset of these alleles, suggesting that it is not the reduced serum levels of alpha 1AT per se which cause the liver disease. The present study characterizes the alpha 1AT deficiency allele Mmalton, an allele that like the common Z deficiency mutation (Glu342----Lys) is associated with both alpha 1AT deficiency and hepatic disease. Capitalizing on the identification of the homozygous inheritance of the rare Mmalton alpha 1AT deficiency allele, it was demonstrated that although caused by a very different mutation, the Mmalton allele shares with the Z allele the association of liver disease with the same type of abnormalities of alpha 1AT biosynthesis. Cloning of the Mmalton gene and sequence analysis demonstrated that it differs from the normal alpha 1AT M2 allele by deletion of the entire codon (TTC) for residue Phe52. Liver biopsy of the Mmalton homozygote revealed inflammation, mild fibrosis, and intrahepatocyte accumulation of alpha 1AT. Evaluation of de novo alpha 1AT biosynthesis in alpha 1AT-synthesizing cells of this individual demonstrated normal levels of alpha 1AT mRNA transcripts but abnormal intracellular accumulation of newly synthesized alpha 1AT at the level of the rough endoplasmic reticulum with consequent reduced alpha 1AT secretion. Finally, retroviral gene transfer of a normal alpha 1AT cDNA and an alpha 1AT cDNA with the Mmalton Phe52 deletion into murine cells demonstrated that the Mmalton cells reproduced the abnormal accumulation of newly synthesized alpha 1AT, thus directly demonstrating that the deletion mutation is responsible for the intracellular accumulation of the newly synthesized alpha 1AT. Thus, not only is the liver disease associated with alpha 1AT deficiency restricted to a subset of alpha 1AT deficiency alleles, it appears to be restricted to those alleles associated with intracellular accumulation of newly synthesized alpha 1AT, suggesting that it is the abnormal intrahepatocyte alpha 1AT accumulation which incites the liver injury.
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PMID:Molecular basis of the liver and lung disease associated with the alpha 1-antitrypsin deficiency allele Mmalton. 278 66

Homozygous inheritance of the Z-type mutant form of the alpha 1-antitrypsin (alpha 1AT) gene results in the most common form of alpha 1AT deficiency, a human hereditary disease associated with a high risk for the development of emphysema and an increased incidence of neonatal hepatitis. The alpha 1AT-synthesizing cells of individuals with the Z gene have normal alpha 1AT messenger RNA levels, but alpha 1AT secretion is markedly reduced secondary to accumulation of newly synthesized alpha 1AT in the rough endoplasmic reticulum. Crystallographic analysis of alpha 1AT predicts that in normal alpha 1AT, a negatively charged Glu342 is adjacent to positively charged Lys290. Thus the Glu342----Lys342 Z mutation caused the loss of a normal salt bridge, resulting in the intracellular aggregation of the Z molecule. The prediction was made that a second mutation in the alpha 1AT genet that changed the positively charged Lys290 to a negatively charged Glu290 would correct the secretion defect. When the second mutation was added to the Z-type complementary DNA, the resulting gene directed the synthesis and secretion of amounts of alpha 1AT similar to that directed by the normal alpha 1AT complementary DNA in an in vitro eukaryotic expression system. This suggests the possibility that a human hereditary disease can be corrected by inserting an additional mutation in the same gene.
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PMID:Repair of the secretion defect in the Z form of alpha 1-antitrypsin by addition of a second mutation. 290 2


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