Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Interactions of vascular endothelial cells (ECs) and smooth muscle cells (SMCs) were studied by testing the ability of cultured bovine aortic ECs to secrete factors influencing the migration of cultured aortic SMCs from the same species. Migration of SMCs was examined in blind-well chambers using gelatin-coated polycarbonate filters. Conditioned culture medium obtained by incubating confluent monolayers of ECs in serum-free RPMI-1640 medium for 48 hours caused a 2.4-fold increase in the migration of SMCs as compared with nonconditioned medium (p less than 0.001). The effect was dependent on the length of conditioning with the ECs and was chemotactic in nature as judged on the basis of checkerboard analysis. Preliminary characterization of the migration stimulating activity indicates that it is sensitive to trypsin, nondialyzable, and stable at 56 degrees C for 30 min. The activity was abolished by heating to 100 degrees C for 20 min but was not significantly inhibited by protamine sulphate, which suggests that most of the activity was not due to platelet-derived growth factor (PDGF)-like proteins. Our results thus show that ECs secrete polypeptide(s) chemotactic for vascular SMCs. Such interactions between ECs and SMCs in vivo might contribute to the migration of medial SMCs into the intima during atherogenesis.
 ...
PMID:Cultured bovine aortic endothelial cells secrete factor(s) chemotactic for aortic smooth muscle cells. 271 9

A continuous cell line of murine alveolar macrophages (AM), designated MH-S, has been established following transformation of cells obtained by bronchoalveolar lavage from Balb/cJ mice with simian virus 40 (SV40). Thirty days after infection of the AM cultures, foci of rapidly proliferating cells were recovered and these have been propagated continuously for more than 36 mo. Following its initial isolation in Fischer's medium supplemented with L-cell-conditioned medium and horse and fetal bovine serum, the cell line is now routinely grown in RPMI-1640 medium containing 10% fetal bovine serum in the absence of conditioned medium. MH-S cells were adherent, lacked contact inhibition, and were trypsin-sensitive. They expressed intracellular T-antigen and incorporated 3H-thymidine (DNA synthesis) with a doubling time of approximately 48 h but doubled in number in 96 h. MH-S exhibited typical macrophage morphology, was greater than 98% esterase-positive, negative for peroxidase, and expressed cell surface Ia and Mac-1 antigens. The cells were Fc receptor-positive as demonstrated by rosette formation with, and phagocytosis of, antibody-coated sheep erythrocytes. Constitutive IL-1 secretion was significantly increased following stimulation of the cells with lipopolysaccharide. Like freshly isolated AM, MH-S cells suppressed the in vitro plaque-forming cell (PFC) response in a dose-dependent manner when cultured with splenic lymphocytes. This cell line should facilitate studies where homogeneous populations of AM are desirable, especially those involved in determining the immunological functions of AM and their potential role in lung pathology.
 ...
PMID:MH-S, a murine alveolar macrophage cell line: morphological, cytochemical, and functional characteristics. 278 72

The effect of trypsin treatment on the transformation of monomorphic Trypanosoma b. gambiense (Wellcome strain) bloodstream forms to procyclic forms was studied in HEPES-buffered RPMI 1640 medium supplemented with 20% inactivated fetal calf serum in the presence of GA-1 cells as feeder layers at 27 degrees C. In this system, 35%-40% of the bloodstream forms transformed to procyclic forms within 24 h, and over 95% of the trypanosomes changed into procyclic forms by day 3 after initiation of the culture. Established cultures of procyclic forms yielded up to 1.5-2 x 10(7) trypanosomes/ml. However, transformation of nontreated and inhibited trypsin-treated bloodstream forms were prolonged compared to trypsin-treated populations. In this experiment, the first procyclic forms could be detected on day 7 after initiation of the culture and transformation was complete within 15 days. The transformation of T. b. gambiense from bloodstream to procyclic forms required the living GA-1 cells as feeder layer cells, but established cultures of procyclic forms could be maintained in the culture medium without feeder cells for more than 300 days.
 ...
PMID:Trypsin-stimulated transformation of Trypanosoma brucei gambiense bloodstream forms to procyclic forms in vitro. 319 62

Cell culture systems allow the examination of cell populations in a functional state. To simulate in vivo conditions as closely as possible freshly established cell strains are superior to permanent cell lines. Different aspects for the establishment of primary cell cultures obtained from various tissues are compared: Disintegration, culture media supplemented with basal additions, special supplements (growth factors, hormones), and attachment factors. The proliferation rates of the attained cell strains were evaluated by determination of cell doubling times. Procedures for how to obtain a relatively high plating efficiency (approx. 70% in our series of 219 attempts) of primary growth in vitro are described: (1) Mechanical disintegration is superior to enzymatic digestion. If mechanical treatment alone did not produce a sufficient number of viable cells, additional digestion with collagenase/dispase revealed a higher number of proliferating primary cultures than with trypsin. (2) Proliferation of cell cultures from normal and tumorous tissues of epithelial origin was superior in Leibovitz L 15 medium (58 of 87 (67%) cases). Cultures from mesenchymal tissues and tumors were found to have shortest cell doubling times in MEM and RPMI 1640 (16 of 23 (70%) cases). The media were supplemented with the basal additions indicated. (3) In approx. 30% of the cases special supplements like growth factors or hormones increased cell replication, although they were almost always not essential for cell growth. (4) Attachment factors only rarely contributed to the initiation of primary monolayer cultures. The application of various culture conditions does not lead to a protocol optimal for all tissues, for all probes of the same type of tumor, or for all tumor specimens of unique differentiation.
 ...
PMID:Establishment of primary cell cultures: experiences with 155 cell strains. 330 16

Rat thymocytes incubated in RPMI medium for 120-300 min release a soluble factor of molecular weight below 10,000 Da which inhibits the binding of 3H-labeled muscarinic antagonists in an uncompetitive manner, i.e. it reduces maximal specific binding (Bmax) without changing the affinity of the ligand (KD). This factor inhibited muscarinic antagonist binding on thymocytes and rat cerebral cortex cellular membranes. Thymocytes from hydrocortisone-treated rats produced more factor per mg cell protein than thymocytes from untreated rats. The activity of the factor was unaffected by incubation with Cd2+ (1 mM) or Zn2+ (1 mM) or EDTA (1 mM), and its protein nature is supported by the following findings: it was trypsin sensitive, heat denaturated at 56 degrees C and precipitated by (NH4)2SO4 (40%, w/v). Inhibition by the factor was apparently irreversible after 1 h of incubation.
 ...
PMID:Rat thymocytes release a factor which inhibits muscarinic ligand binding. 333 20

Treatment of porcine lymphocytes with trypsin reduced their spontaneous cell-mediated cytotoxicity (SCMC) activity against target cells persistently infected with transmissible gastroenteritis virus (PK15-TGE cells), but had no effect on antibody-dependent cell-mediated cytotoxicity (ADCC). SCMC activity was partially restored to trypsin-treated lymphocytes by incubation in RPMI-1640 medium or in medium containing F(ab')2 fragments of rabbit anti-porcine immunoglobulin, but not by brief incubation in autologous serum. F(ab')2 fragments of anti-porcine immunoglobulin did not block the SCMC reaction, but ADCC was greatly reduced by this reagent. Thus SCMC and ADCC mediated by porcine lymphocytes against PK15-TGE target cells clearly involved two distinct mechanisms in terms of antibody participation and sensitivity to trypsin.
 ...
PMID:The participation of antibody in spontaneous and antibody-dependent cell-mediated cytotoxicity in the pig. 344 94

Epithelial and stromal cells were isolated from endometrium of Day 1 pseudopregnant rabbits by enzymatic digestion with trypsin or trypsin:collagenase:deoxyribonuclease. Dispersed cells were grown in RPMI 1640 supplemented with 10% whole or steroid-depleted fetal bovine serum (FBS). Epithelial and stromal cells reached confluency after 6 to 7 days in culture and showed specific characteristics. Cells could be differentiated according to morphology, growth patterns, electrophoretic patterns, and response to estrogen or progesterone. Hormonal stimulation of adenylate cyclase activity was measured in broken cell preparations by catalytic transformation of alpha-32P-adenosine triphosphate into 32P-adenosine 3'-5' cyclic monophosphate (cAMP). Adenylate cyclase activity was present in fresh endometrial tissue and in dispersed cells after 7 days in culture. The enzyme activity was significantly higher in stromal than in epithelial cells at all stimulation levels: basal (9.2 +/- 1.0 vs. 2.3 +/- 0.6, p less than 0.001) and guanosine triphosphate (GTP, 300 microM) (25.4 +/- 2.9 vs. 7.0 +/- 1.6, p less than 0.001). Net response to prostaglandin E2 (PGE2, 10 microM) was three times higher (p less than 0.001) in stromal (17 +/- 2) than in epithelial (5.0 +/- 1) cells. These results suggest that PGE2 can stimulate adenylate cyclase in rabbit endometrium and that the enzyme is preferentially localized in the stroma. Our results are in agreement with the hypothesis that cAMP formed in endometrium in response to PGE2 might be involved in the decidual reaction.
 ...
PMID:Cell-specific localization of prostaglandin E2-sensitive adenylate cyclase in rabbit endometrium. 347 35

IgE-binding factors (IgE-BFs) were purified from the culture supernatant of RPMI-8866 cells, a human lymphoblastoid B-cell line expressing IgE receptors. The material, purified by affinity-chromatography on immunoadsorbents coupled to IgE or to monoclonal antibody against IgE receptor, was comprised of two major components with apparent molecular weight (MW) of 25,000-27,000 and 12,000, as determined by SDS-PAGE and silver staining. Only the 25,000-27,000 MW molecules were identified as IgE-BFs, as demonstrated by their reactivity with MabER in the Western blot and the immunoprecipitation assays, and their ability to inhibit rosette formation of U937 cells with IgE- but not with IgG-coated erythrocytes. IgE-BFs were purified to homogeneity by combining affinity-chromatography and either DEAE-ion exchange or reverse-phase chromatography on an HPLC system. Chromatofocusing analysis demonstrated the microheterogeneity of IgE-BFs that were comprised of molecules with isoelectric points ranging from 5.0 to 4.4. IgE-BFs were sensitive to treatment with O-glycosidase but not with N-glycanase. These molecules were resistant to heat and to pH ranging from 2 to 9; their immunoreactivity was lost after treatment with trypsin and pepsin. Papain digestion of purified IgE-BFs generated 14,000-16,000 MW molecules that were still binding to IgE and to MabER.
 ...
PMID:Purification and partial biochemical characterization of IgE-binding factors secreted by a human B lymphoblastoid cell line. 349 83

The culture supernatants of unstimulated T cells (TCS) from asthmatic patients with elevated serum IgE were tested for IgE-binding factors (IgE-BFs) displaying the IgE-potentiating activity. The IgE-BFs were detected by their ability to inhibit the rosetting of RPMI 8866 cells with ox erythrocytes coupled with mouse monoclonal antibody (E-Mab) specific to Fc receptors for IgE (Fc epsilon R). TCS showing the rosette-inhibiting activity significantly enhanced the spontaneous IgE synthesis by B cells of allergic individuals. Interestingly, rosette-inhibiting factors could be removed by absorption with IgE-Sepharose from which they were subsequently eluated with acid buffer, indicating that the rosette inhibition was indeed mediated by IgE-BFs. In addition, such IgE-BFs had affinity for concanavalin A and lost their IgE-potentiating activity after treatment with trypsin and neuraminidase. In contrast, T cells treated with tunicamycin released IgE-suppressing factors capable of inhibiting the IgE-potentiating activity of TCS derived from untreated T cells. On the other hand, the culture supernatants from subpopulations depleted of Fc epsilon R+ T cells but not of Fc gamma R+ T cells contained neither rosette-inhibiting factors nor IgE-potentiating factors, suggesting that IgE-BFs were released by in vivo pre-activated Fc epsilon R+ T cells. With regard to circulating Fc epsilon R+ T cells determined by E-Mab, they were significantly higher in asthmatic patients with elevated serum IgE (0.77 +/- 0.15%) than in normal subjects (0.17 +/- 0.07%) in spite of a very small proportion of T cells bearing Fc epsilon R.
 ...
PMID:Modulation of IgE synthesis by IgE-binding factors released by T cells of asthmatic patients with elevated serum IgE. 349 27

Techniques were perfected for the enzymatic dissociation of chicken pituitary glands and a number of factors evaluated for their effects upon growth hormone (GH) production by dispersed chicken pituitary cells in culture. Age-related changes in donor pituitary weight and GH content were also determined. A procedure involving digestion of minced glands with a solution of 0.1% trypsin in S-MEM tissue culture medium (0.1% BSA) for 1 hr at 37 degrees under an atmosphere of 5% CO2-95% air yielded greater than 2.0 X 10(6) cells per gland with 80-90% viability. Five tissue culture media (D-MEM, alpha-MEM, RPMI 1640, Med-199, Earle's salts), two serum sources (calf serum (CS), horse serum (HS), and two levels of serum (5, 20%) were tested for their ability to support GH synthesis over 4 days in culture. Additionally, two culture regimes (continuous culture vs daily media changes) were evaluated for their effects on GH production. alpha-MEM resulted in the numerically highest net GH synthesis (over starting cell content), although not statistically different from RPMI 1640 or Earle's salts. Neither serum type nor percentage was significant; therefore the lower serum percentage (5) was adopted for future studies. Culture regime significantly altered the proportion of secreted vs stored hormone harvested at the end of the culture period. Changing media daily resulted in a 40% reduction in final cell GH content compared to continuous culture, whereas total cumulative media GH was approximately 39% greater (P less than 0.01). Pituitary weight increased with age until approximately 9 weeks, whereas GH content plateaued earlier, at 5 weeks of age.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Preparation and culture of dispersed avian pituitary cells, and age-related changes in donor pituitary weight and growth hormone content. 355 85


<< Previous 1 2 3 4 5 6 Next >>