Michael A. Lieberman

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Recent studies suggest that sepsis-induced increase in muscle proteolysis mainly reflects energy-ubiquitin-dependent protein breakdown. We tested the hypothesis that glucocorticoids activate the energy-ubiquitin-dependent proteolytic pathway in skeletal muscle during sepsis. Rats underwent induction of sepsis by cecal ligation and puncture or were(More)
Patients suffering from cystic fibrosis (CF) commonly harbor the important pathogen Pseudomonas aeruginosa in their airways. During chronic late-stage CF, P. aeruginosa is known to grow under reduced oxygen tension and is even capable of respiring anaerobically within the thickened airway mucus, at a pH of approximately 6.5. Therefore, proteins involved in(More)
We tested the role of different intracellular proteolytic pathways in sepsis-induced muscle proteolysis. Sepsis was induced in rats by cecal ligation and puncture; controls were sham operated. Total and myofibrillar proteolysis was determined in incubated extensor digitorum longus muscles as release of tyrosine and 3-methylhistidine, respectively. Lysosomal(More)
Inducible eukaryotic promoters, particularly those responsive to glucocorticoids or heavy metals, have been extensively used to study the consequences of induction of a target gene in mammalian cells. An alternative approach, intended to improve the selectivity of gene induction and to minimize perturbation of chromatin structure, is to utilize elements(More)
Differentiation of pulmonary Type II epithelial cells in late gestation is associated with the synthesis of pulmonary surfactant required for adaptation to air breathing at birth. In the present work, induction of synthesis of a Type II epithelial cell protein, surfactant-associated glycoprotein of Mr = 35,000 (SAP-35) was studied in human fetal lung tissue(More)
We tested the hypothesis that the difference in the response to sepsis of protein breakdown between fast- and slow-twitch skeletal muscle reflects differential activation of the energy-ubiquitin-dependent proteolytic pathway. In addition, we defined the time course and the tissue specificity of sepsis-induced changes in the expression of the ubiquitin(More)
The influence of sepsis on polyamine metabolism in the liver was studied in rats. Sepsis was induced by cecal ligation and puncture; control rats were sham-operated. Sepsis resulted in increased concentrations in liver tissue of putrescine and spermidine and stimulated activity of the enzymes ornithine decarboxylase (ODC) and s-adenosylmethionine(More)
It has been reported previously that a plasma membrane-enriched fraction from 3T3 cells arrests the growth of sparse 3T3 cells early in the G1 phase of growth (Whittenberger et al., '78, '79). Addition of membranes to sparse 3T3 cells also results in a decrease of the rate of transport of alpha-aminoisobutyric acid (Lieberman et al., '79). We have partially(More)
We have cloned from cultured vascular smooth muscle cells a protein tyrosine phosphatase, rat density-enhanced phosphatase-1 (rDEP-1), which is a probable rat homologue of DEP-1/HPTP eta. rDEP-1 is encoded by an 8.7-kb transcript and is expressed as a 180- to 220-kD protein. The rDEP-1 gene is located on human chromosome 11 (region p11.2) and on mouse(More)