Amide molecular clocks in drosophila proteins: potential regulators of aging and other processes

After synthesis and folding, peptides and proteins undergo changes in charge and conformation through nonenzymatic deamidation of asparaginyl and glutaminyl residues. Each amide has a specific deamidation rate that is genetically determined by the sequence of residues immediately adjacent in the peptide chain and by secondary, tertiary, and quaternary structure. By means of experimentally verified computations, we have determined the deamidation rates of 49 Drosophila peptides and proteins. These rates demonstrate that deamidation provides molecular clocks that are suitable for the regulation of Drosophila aging, development, and other biochemical processes. We have also determined the rates of deamidation for 17,886 other proteins from a wide variety of organisms. The distribution function of these deamidation rates demonstrates the suitability of amide residues as biomolecular clocks.     

Ethinyl estradiol treats collagen-induced arthritis in DBA/1LacJ mice by inhibiting the production of TNF-alpha and IL-1beta

We previously demonstrated the therapeutic effects of ethinyl estradiol (EE), an orally active estrogen and a component of birth control pills, in encephalitogenic autoimmune encephalomyelitis (EAE). In this study, we report the effectiveness of EE in treating collagen-induced arthritis (CIA) induced with bovine type II collagen (bCII) in DBA/1LacJ mice, a CIA susceptible strain. Both low and high doses of EE notably suppressed clinical and histological signs of CIA in a dose-dependent manner compared to vehicle-treated controls. Oral treatment with EE decreased proliferation and secretion of pro-inflammatory factors, TNF-alpha IFN-gamma, MCP-1 and IL-6 by bCII peptide-specific T cells, production of bCII-specific IgG2a antibodies, and mRNA for cytokines, chemokines and chemokine receptors in joint tissue. This is the first report demonstrating effective treatment of joint inflammation and clinical signs of CIA with orally administered ethinyl estradiol, thus supporting its possible clinical use for treating rheumatoid arthritis in humans.     

Different strains of Mycobacterium tuberculosis cause various spectrums of disease in the rabbit model of tuberculosis

The rabbit model of tuberculosis has been used historically to differentiate between Mycobacterium tuberculosis and Mycobacterium bovis based on their relative virulence in this animal host. M. tuberculosis infection in market rabbits is cleared over time, whereas infection with M. bovis results in chronic, progressive, cavitary disease leading to death. Because of the innate resistance of commercial rabbits to M. tuberculosis, 320 to 1,890 log-phase, actively growing inhaled bacilli were required to form one grossly visible pulmonary tubercle at 5 weeks. The range of inhaled doses required to make one tubercle allows us to determine the relative pathogenicities of different strains. Fewer inhaled organisms of the M. tuberculosis Erdman strain were required than of M. tuberculosis H37Rv to produce a visible lesion at 5 weeks. Furthermore, with the Erdman strain, only 7 of 15 rabbits had healed lesions at 16 to 18 weeks; among the other animals, two had chronic, progressive cavitary disease, a phenotype usually seen only with M. bovis infection. Genotypic investigation of the Erdman strain with an H37Rv-based microarray identified gene differences in the RD6 region. Southern blot and PCR structural genetic analysis showed significant differences between M. tuberculosis strains in this region. Correlation of the relative pathogenicity, including disease severity, in the rabbit model with the strain genotype may help identify stage-specific M. tuberculosis genes important in human disease.     

Correlates of Control in Pediatric Cancer Patients and Their Families

Physical illness is a life experience which challenges an individual'ssense of control and thus represents a potential threat to mentalhealth. For children, a serious illness threatens not only theirsense of physical and psychological well-being but also threatensthe psychological well-being of their family. In this study,severely ill patients (n = 15) and a member of their family(n = 15) were interviewed. The patients, who ranged in age from12 to 21 years, were being treated for metastatic solid tumorsor lymphoma that failed to respond to conventional therapeuticregimens. Correlates of control for the patients and familymembers, the relationship between control and developmentalstage of the patients, and the difference between levels ofcontrol in patients and family member were examined. The findingsare discussed in relation to development and their implicationsfor medical management.     

The Role of Cathepsin D in the Pathogenesis of Tuberculosis: A Histochemical Study Employing Unlabeled Antibodies and the Peroxidase-Antiperoxidase Complex

Cathepsin D was visualized in free pulmonary alveolar macrophages (AM), in oil-induced peritoneal macrophages (MN) and in rabbit pulmonary and dermal BCG lesions with unlabeled antibodies and the peroxidase-antiperoxidase (PAP) complex. Large amounts of cathepsin D were present in AM and lower amounts in MN. In the lung this enzyme was richest in the alveolar macrophages that accumulated around the BCG lesions. In the dermal lesions, cathepsin D was in highest concentration in macrophages at the border of the necrotic (liquefying) centers. It was also found in high concentration in keratinizing cells of the dermal epithelium and hair follicles. It did not, however, increase appreciably in many of the activated macrophages that stained intensely for the lysosomal enzyme β-galactosidase. In fact, many epithelioid cells with high β-galactosidase activity contained no visible cathepsin D. This proteinase does not, therefore, seem to be primarily involved in the lymphocyte-mediated macrophage activation associated with acquired cellular resistance to tubercle bacilli. It is probably more involved with cell autolysis, with the digestion of ingested necrotic debris and, in all likelihood, with the process of liquefaction, the most adverse event in the pathogenesis of tuberculosis in man.     

Heligmosomoides polygyrus inhibits established colitis in IL-10-deficient mice

Inflammatory bowel disease (IBD) is prevalent in industrialized countries, but rare in less-developed countries. Helminths, common in less-developed countries, may induce immunoregulatory circuits protective against IBD. IL-10(-/-) mice given piroxicam develop severe and persistent colitis. Lamina propria mononuclear cells from colitic IL-10(-/-) mice released IFN-gamma and IL-12. The ongoing piroxicam-induced colitis could be partially blocked with anti-IL-12 monoclonal antibody suggesting that the inflammation was at least partly IL-12 dependent. Colonization of piroxicam-treated colitic IL-10(-/-) mice with Heligmosomoides polygyrus (an intestinal helminth) suppressed established inflammation and inhibited mucosal IL-12 and IFN-gamma production. H. polygyrus augmented mucosal IL-13, but not IL-4 or IL-5 production. Transfer of mesenteric lymph node (MLN) T cells from IL-10(-/-) animals harboring H. polygyrus into colitic IL-10(-/-) recipients inhibited colitis. MLN T cells from worm-free mice did not. Foxp3 (scurfin) drives regulatory T cell function. H. polygyrus enhanced Foxp3 mRNA expression in MLN T cells that had regulatory activity. This suggests that H. polygyrus inhibits ongoing IL-10(-/-) colitis in part through blocking mucosal Th1 cytokine production. Resolution of inflammation is associated with increased IL-13 production and can be adoptively transferred by MLN T cells.