Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mastocytosis, a disease that varies in its clinical presentation, is usually documented by histologic examination of lesional skin. However, no universally accepted histopathologic criteria exist for establishing the diagnosis of this disease. We have combined the method of morphometric point counting with the mast cell-specific stain, conjugated avidin, to accurately quantify mast cells in cutaneous tissue sections of mastocytosis. Using this histologic approach, we found that macules, papules, and nodules of mast cell disease had from ninefold to nearly a 160-fold greater mast cell content than was observed in normal skin and in several other cutaneous disorders. This technique also permitted the objective histologic stratification of mastocytosis skin lesions according to their mast cell density. Morphometric point counting in conjunction with conjugated avidin offers a simple and accurate method for establishing the diagnosis of mastocytosis.
 ...
PMID:Diagnosis of mastocytosis subsets using a morphometric point counting technique. 244 79

In allergic and nonallergic lung diseases, if intraluminal mast cells adhere to airway epithelium, inflammatory mediators released from activated mast cells may reach high local concentrations and thus greatly affect airway function. To determine whether mast cells adhere to airway epithelial cells, radiolabeled or unlabeled dog mastocytoma cells were incubated with cultured dog tracheal epithelial cells, with extracellular matrix substrates, and with cryostat-cut sections of dog trachea. Mast cells adhered well to cultured epithelial cells (35 +/- 13% adhesion, mean +/- 1 SD, n = 23) but adhered poorly to types I and IV collagen or to fibronectin (less than 7.5% mean adhesion in all cases). Similarly, in tracheal tissue sections, mast cells adhered preferentially to epithelial cells in surface epithelium or in submucosal glands but not to basal membrane or connective tissue. Adhesion to cultured epithelial cells was a characteristics of a subpopulation of mast cells, could persist for more than 48 h, did not require energy or the presence of divalent cations, and was not mediated by a known family of leukocyte-associated adhesion glycoproteins. Adhesion was completely abolished by pretreatment of mast cells with pronase E or proteinase K but not with trypsin (up to 10 micrograms/ml at 37 degrees C for 20 min each). In contrast, pretreatment of cultured epithelial cells with any of these proteinases had no effect on adhesion. It is concluded that dog mastocytoma mast cells adhere to dog tracheal epithelial cells and do so selectively. It is suggested that mast cell adhesion to airway epithelium may play a role in the effectiveness of mast cell-epithelial cell interactions, and thus, in certain lung diseases, airway function may be affected by intraluminal mast cells more than is currently appreciated.
 ...
PMID:Selective adhesion of mast cells to tracheal epithelial cells in vitro. 245 Sep 14

Submucosal glands are the major sources of airway secretions in most mammals. Mast cells are abundant in the environment of airway submucosal glands and are rich sources of secreted proteases. To investigate the hypothesis that mast cell proteases stimulate airway gland secretion, we studied the ability of the two major mast cell granule proteases, chymase and tryptase, to cause secretion of 35S-labeled macromolecules from a line of cultured bovine airway gland serous cells. Mast cell chymase and tryptase were purified from dog mastocytoma cells. Chymase markedly stimulated serous cell secretion in a concentration-dependent fashion with a threshold of 10(-10) M, whereas tryptase had no effect. The response to 10(-8) M chymase (1530 +/- 80% over base line) was approximately 10-fold higher than that evoked by other agonists such as histamine and isoproterenol. The predominant 35S-labeled macromolecule released by chymase was chondroitin sulfate proteoglycan, the glycoconjugate present in serous cell secretory granules. The response to chymase was non-cytotoxic and was blocked by active site inhibitors of chymase (soybean trypsin inhibitor and chymostatin) and by inhibitors of cellular energy metabolism (azide,2,4-dinitrophenol, dicumarol). Supernatant obtained by degranulation of mastocytoma cells caused a secretory response of comparable magnitude to that caused by chymase. These findings demonstrate that chymase, but not tryptase, is a potent secretagogue for airway gland serous cells, and they suggest a possible role for chymase-containing mast cells in the pathogenesis of airway hypersecretion.
 ...
PMID:Mast cell chymase. A potent secretagogue for airway gland serous cells. 249 59

Recent evidence suggests that nonadrenergic airway relaxation may be controlled by vasoactive intestinal peptide (VIP). The magnitude and duration of smooth muscle relaxation in response to VIP may be influenced by rates of peptide degradation after release from efferent peptidergic neurons. To explore the potential role of mast cell mediators in modulating neural control of airway tone, we studied the effect of the mast cell proteases tryptase and chymase on airway smooth muscle relaxation induced by VIP in ferret airway. Tracheal rings precontracted by serotonin (10(-6) M) in a muscle bath were relaxed by VIP (10(-7) M). We found that protease-rich supernatant obtained by degranulation of dog mastocytoma cells reversed VIP-induced relaxation, as did highly purified tryptase and chymase incubated with the tracheal rings. Either enzyme completely reversed the effect of VIP, but tryptase was more potent than chymase, paralleling previous test tube observations on the relative rates of VIP cleavage by the two enzymes. Inhibitors of mast cell tryptase and chymase preincubated with the supernatant or with the purified proteases prevented reversal of VIP-induced relaxation. Mast cell proteases did not reverse the tracheal relaxation caused by the nonpeptide adrenergic agonist isoproterenol. These findings show that mast cell proteases tryptase and chymase counteract the smooth muscle relaxant effects of VIP in ferret trachea and suggest a potential role for the mast cell proteases in the modulation of nonadrenergic neural control of airway tone by VIP.
 ...
PMID:Mast cell tryptase and chymase reverse airway smooth muscle relaxation induced by vasoactive intestinal peptide in the ferret. 249 55

Mast cell tryptase is a secretory granule associated serine protease with trypsin-like specificity released extracellularly during mast cell degranulation. To determine the full primary structure of the catalytic domain and precursor forms of tryptase and to gain insight into its mode of activation, we cloned cDNAs coding for the complete amino acid sequence of dog mast cell tryptase and a second, possibly related, serine protease. Using RNA from dog mastocytoma cells, we constructed a cDNA library in lambda gt 10. Screening of the library with an oligonucleotide probe based on the N-terminal sequence of tryptase purified from the same cell source allowed us to isolate and sequence overlapping clones coding for dog mast cell tryptase. The tryptase sequence includes the essential residues of the catalytic triad and an aspartic acid at the base of the putative substrate binding pocket that confers P1 Arg and Lys specificity on tryptic serine proteases. The apparent N-terminal signal/activation peptide terminates in a glycine. A glycine in this position has not been observed previously in serine proteases and suggests a novel mode of activation. Additional screening of the library with a trypsinogen cDNA led to the isolation and sequencing of a full-length clone apparently coding for the complete sequence of a second tryptic serine protease (DMP) which is only 53.4% identical with the dog tryptase sequence but which contains an apparent signal/activation peptide also terminating in a glycine. Thus, the proteases encoded by these cloned cDNAs may share a common mode of activation from N-terminally extended precursors.
 ...
PMID:Molecular cloning of dog mast cell tryptase and a related protease: structural evidence of a unique mode of serine protease activation. 250 77

Mastocytosis represents a spectrum of clinical disorders that results from an aberrant proliferation of tissue mast cells. This disease process may be confined to the skin (cutaneous mastocytosis) or may involve multiple organs (systemic mastocytosis). Parameters that are useful in differentiating cutaneous from systemic disorders include patient age, symptom complex, and clinical signs. A wide range of clinical symptoms may be encountered in patients with mastocytosis which result from the release of pharmacologically potent mast cell mediators. Distinct cutaneous patterns resulting from skin mast cell infiltrates can be helpful in identifying patients with systemic involvement. The diagnosis of mastocytosis is confirmed by demonstrating increased tissue mast cells in involved organs. The overall prognosis for patients with proliferative mast cell disease is relatively good, although a small percentage are at risk for developing a fatal neoplastic disorder (malignant mastocytosis). Treatment of mastocytosis is directed at both inhibiting mast cell degranulation and blocking the potential systemic effects of released secretory products. Future therapeutic advances depend upon an improved understanding of the basic mechanisms involved in mast cell mediator release and the forces that govern mast cell growth and development.
 ...
PMID:The spectrum of mastocytosis. 257 53

The mast cell proteases tryptase and chymase have long been known to constitute one-fifth of the total protein in mast cells. However, their biological functions have not been easy to study because of the difficulty in obtaining sufficient amounts of the enzymes to study their biological functions. Recently, we have been fortunate to have available a permanent line of dog mastocytoma cells to purify both enzymes to homogeneity, and we have used the purified enzymes in two ways. First, in a series of biological studies, we have discovered unique and potent actions of the enzymes that may provide important insights into the pathogenesis of diseases such as asthma and cystic fibrosis. Important biological activities are also likely to exist in other tissues. Because of their structures, mast cell proteases are likely to act in proximity to their sites of release. Thus, the presence and amounts of tryptase and chymase in specific loci may play important roles in tissue responses. In diseases such as asthma and cystic fibrosis, there is evidence that the expression of these mast cell enzymes changes, and these changes have important pathogenetic implications. Second, we have begun to perform structural studies of the enzymes. The recent cloning of tryptase by our group should assist in the better understanding of its functions. Crystallography of the pure proteins should provide further insights and could be the basis of rational development of potent and selective drugs that will inhibit their actions.
 ...
PMID:Roles of mast cell proteases in airways. 266 41

A solitary mastocytoma of the skin was investigated to assess the lectin-binding pattern of human mast cells. Of 18 Fluorescein-labelled lectins tested, nine reacted with mast cell granules. While lectins recognizing N-acetylgalactosamine or fucose residues did not stain mast cells, lectins with binding sites for N-acetylglucosamine, alpha-methyl mannopyranoside, galactose, complex carbohydrates of N-acetyl-lactosamine type and sialic acid gave a positive reaction.
 ...
PMID:Lectin-binding studies of a human skin mastocytoma. 274 58

Mastocytosis is a disease characterized by an increase in the number of tissue mast cells and a concomitant increase in mast cell-derived mediators. To demonstrate the spectrum of skin disease in mastocytosis in the pediatric population, five children with mastocytosis and complaints of urticaria (4/5), bullae/vesicles (3/5), abdominal pain (3/5), flushing (2/5), headache (1/5), and bone pain (1/5) are reviewed. Confirmation of the diagnosis of cutaneous mastocytosis was obtained by histologic examination of a biopsy of lesional skin; however, mast cell numbers in lesional skin did not correlate with plasma histamine levels or the extent of cutaneous involvement. Mastocytosis is a diagnosis that must be recognized in the differential diagnosis of pediatric urticarial diseases.
 ...
PMID:Mastocytosis in infants and children: recognition of patterns of skin disease. 292 86

We examined the interaction between mast cell-derived mediators and the electrical and ion transport properties of canine tracheal epithelium. We compared the effect of mediators released by immunologic challenge of sensitized lung parenchyma with that of mediators released from canine mastocytoma cells challenged with calcium ionophore A23187. Short-circuit current (Isc) increased by 19.2 +/- 3.0 microA/cm2 in response to mediators released from sensitized lung fragments challenged with ragweed antigen. This effect was not due to histamine. When the epithelial tissues were pretreated with indomethacin, the same mediator supernatant increased Isc by only 3.8 +/- 4.3 microA/cm2. The mediators released from 10(7) mastocytoma cells challenged with calcium ionophore increased Isc by 25.1 +/- 13.6 microA/cm2. In the presence of indomethacin, the Isc increased by 2.0 +/- 0.4 microA/cm2. Mastocytoma-derived mediators produced an increase in net chloride secretion without a significant effect on net sodium absorption. This study provides direct evidence that mast cell-derived mediators can stimulate epithelial ion transport in canine trachea and suggests that the effect is indirect and dependent on intact cyclooxygenase pathways in the tracheal epithelium.
 ...
PMID:Effects of mast cell-derived mediators on epithelial cells in canine trachea. 309 76


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>