Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Primary cultured rat epidermal keratinocytes were used as an experimental model to detect oxidant-mediated adverse effects of dithranol (anthralin), a widely used antipsoriasis drug with tumor-promoting and skin-irritating properties. Keratinocytes were isolated and prepared from the skin of neonatal rats by a trypsin flotation method. Highly proliferative monolayer cells cultured in a serum-free medium were exposed to the test compound at concentrations (5-100 microM) used therapeutically for the treatment of skin disorders. Cytotoxicity was evaluated by changes in plasma membrane integrity (lactate dehydrogenase leakage), lysosomal function (neutral red uptake), and mitochondrial metabolic activity (reduction of 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, MTT). Exposure of keratinocytes to dithranol produced time- and concentration-related toxic responses. MTT reduction was found to be a more sensitive endpoint of cytotoxicity, showing significant toxic effects at 2 hr, while significant leakage of lactate dehydrogenase did not result until 6 hr. Oxygen consumption in keratinocytes and isolated mitochondria showed a similar pattern after exposure to dithranol. Increased cyanide-insensitive respiration was also noted. Oxidative stress, measured by superoxide anion-dependent reduction of nitroblue tetrazolium, occurred before dithranol produced cytotoxicity in the keratinocyte cultures. Superoxide formation, which increased with time after dithranol exposure, was detected both extracellularly and intracellularly and was inhibited by the addition of superoxide dismutase. Dithranol-induced cell injury was partially prevented by treatment with superoxide dismutase, and greater protection was shown by concurrent treatment with superoxide dismutase plus catalase. These findings suggest that the superoxide anion and hydrogen peroxide may be involved in the cytotoxicity of dithranol and that a culture system of rat keratinocytes may be useful in evaluating the mechanism of toxicity of dermatotoxicants.
...
PMID:Dithranol-induced cytotoxicity in primary cultures of rat epidermal keratinocytes. I. The role of reactive oxygen species. 184 45

Swine interleukin 2 (IL-2) activity was assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay using murine IL-2 dependent cell line (CTLL-2). The culture supernatant of mesenteric lymph node (MLN) cells stimulated with phytohemagglutinin-P (PHA) induced a generation of MTT formazan in a dose-dependent manner, suggesting dose-dependent proliferation of CTLL-2. The maximal swine IL-2 activity was observed in the culture of MLN cells at 1 to 2 x 10(7) cells/ml when stimulated with 20 to 40 micrograms/ml PHA for 48 hr. Based on these findings, a large culture of MLN cells to prepare swine IL-2 were performed under the following condition; cell concentration of 1 x 10(7) cells/ml, PHA concentration of 20 micrograms/ml, a culture scale of 200 to 400 ml, and a stirring speed of 30 rpm. Swine IL-2 activity was detected from 4 hr after PHA stimulation, and rapidly increased until 16 hr. Almost maximal IL-2 activity in stirring culture was observed at the incubation of 20 hr. Swine IL-2 was partially purified by Sephacryl S-200 gel filtration and the estimated molecular weight was about 32 kD based on the peak of IL-2 activity. The pI value of swine IL-2 was estimated to be approximately pH 5.3. Swine IL-2 was sensitive to acid (pH 3.2) or alkaline (pH 10.5), 4 or 8 M urea, trypsin, and the heating at 70 degrees C. These physico-chemical properties of swine IL-2 was similar to those of human, murine or feline IL-2.
...
PMID:Swine interleukin 2 activity produced by mesenteric lymph node cells. 828 23

The presence of the nematode parasite Trichostrongylus colubriformis in the small intestine is associated with an increase in epithelial renewal. To assess the possible role of excretory/secretory products from the worm on cell proliferation, adult Trichostrongylus colubriformis were incubated in vitro in Dulbecco's Modified Eagle's Medium for 24 h and the conditioned medium was added to the culture medium of the transformed epithelial cell line HT29-D4. A stimulation of the HT29-D4 cell growth was ascertained at concentrations of 0.25-1.0 micrograms protein/ml using counts of cell numbers, the MTT method and incorporation of tritiated thymidine. An increased incorporation of tritiated thymidine was also observed with the excretory/secretory products from T. colubriformis fourth stage larvae at 1.0 microgram/ml. Dialysis of the medium conditioned by the worms indicated that the molecular weight of the factor is greater than 8000 Daltons in size. Heat treatment, acid hydrolysis and precipitation by trichloracetic acid of the conditioned medium resulted in the disappearance of the proliferative effect while treatment with trypsin partially depleted the stimulative activity. These results suggest that T. colubriformis produce some protein factor which could increase the epithelial regeneration in the host small intestine.
...
PMID:Stimulation of HT29-D4 cell growth by excretory/secretory products of the parasite nematode Trichostrongylus colubriformis. 868 22

Vast experience with cultivating biopsies from human tumors indicates that in most cases the admixture of fibroblasts has a negative effect on growth of tumor cells. Only rarely is observed help provided by the fibroblasts. It has also long been known that fibroblasts can inhibit by contact themselves and also produce growth factor(s) promoting cell proliferation. We have used three permanent squamous cell carcinoma lines and fibroblasts derived from biopsies of trachea to study this paradox. The inhibitory activity of fibroblasts is contact-dependent in a cell membrane-bound factor, which is trypsin sensitive. We prepared microsomal fractions (MF) from aged (more than 40 passages) fibroblasts and followed their effect on proliferation of the tumor cell lines in MTT assay. MF from all three fibroblast lines inhibited the tumor cells. Most regularly was this phenomenon observed with line UM-SCC 22B. Not all tumor cells are immortal. On the contrary, a large portion of them undergoes terminal differentiation. With the line UM-SCC 22B we tested the possibility that MF from fibroblasts can increase the portion of tumor cells which will senescence after few mitoses. The immortal cells were defined as cells capable in 8 or 13 days of forming colonies of more than 50 or 200 cells. The senescent cells were defined as cells not capable of producing within the same period of time colonies of more than 12 or 30 cells. The MF was able to increase the number of small colonies, i.e. the number of senescent tumor cells. The fibroblasts of the same passage level were releasing soluble growth factor(s) promoting growth of cells. Fibroblasts can apparently simultaneously inhibit growth by contact and release factor(s) promoting growth of cells. The final outcome is a result of the balance between these two forces. This balance is regulated by many intrinsic and extrinsic forces.
...
PMID:Dual role of fibroblasts in tumor cell growth. 871 73

Based on the soluble MTT tetrazolium/formazan assay, we evaluated the cytotoxicity of Erythrina variegata proteinase inhibitors in some tumor hematopoietic stem cell lines. Among the proteinase inhibitors, EBI, which belongs to the Bowman-Birk family of inhibitors, was cytotoxic in relatively differentiated cells such as Molt4 and Jurkat derived from acute T lymphoblastic leukemia (T-ALL) cells specifically, but ETIa and ECI, which are classified into Kunitz family inhibitors, did not. It was suggested that the differences in the cytotoxicity might be due to the molecular size of the inhibitors. The succinylation of lysine residue(s) of EBI led to about 50% loss of the trypsin inhibitory activity as compared with the authentic EBI. When Molt4 cells were incubated with this derivative, no significant cytotoxicity was observed. This suggests that the proteinase inhibitory activity might be involved in the cytotoxicity in human tumor cell lines.
...
PMID:Cytotoxicity induced by Erythrina variegata serine proteinase inhibitors in tumor hematopoietic stem cell lines. 969 1

Lesions of articular cartilage are a common problem and concern millions of people world-wide. A decrease in physical activity and pain symptoms among patients resulting from damage to articular cartilage have prompted research concerning new methods allowing cartilage regeneration. State-of-the-art treatment of articular damage depends very much on genetic engineering techniques. The aim of this paper was to determine the authors' own way of isolation, proliferation and storage of chondrocytes of articular cartilage. The material consisted of 30 rabbits, from which fragments of articular cartilage were taken. The study consisted of the following stages: isolation, chondrocyte proliferation, cell and matrix identification, storage and MTT tests. Matrix digestion was achieved using the following solutions: 0.1% type IA collagenase; 0.025% trypsin, a mixture of collagenase and trypsin. The greatest amount of cells were found after digestion of the basic matter of cartilage by 0.1% solution of type IA collagenase. When ascorbic acid was added to the medium, a 25% increase in cellularity was observed. A cumulation of procollagen mRNA was noted in the isolated cells. After about 21 days the isolated cells formed a multilayer structure, with the space between the cells filled with a substance that showed typical traits for cartilage matrix. Storing the isolated cells for less than 48 hours at room temperature gave a 90% survival rate. Most cells died after less than 12 hours when stored at 4 degrees C. The described method of chondrocyte isolation proved to be effective in preparing material for treatment of articular cartilage lesion.
...
PMID:[The possibility of isolation, culture and storage of articular cartilage cells]. 1138 13

Immunoprotection of pancreatic islets for successful allo- or xenotransplantation without chronic immunosuppression is an attractive, but still elusive, approach for curing type 1 diabetes. It was recently shown that, even in the absence of fibrotic overgrowth, other factors, mainly insufficient nutrition to the core of the islets, represent a major barrier for long-term survival of intraperitoneal microencapsulated islet grafts. The use of dispersed cells might contribute to solve this problem due to the conceivably easier nutritional support to the cells. In the present study, purified bovine islets, prepared by collagenase digestion and density gradient purification, and dispersed bovine islet cells, obtained by trypsin and DNAsi (viability > 90%), were entrapped into either 2% (w/v) sodium alginate (commonly used for encapsulation purposes) or (dispersed islet cells only) macroporous gelatin microcarriers (CulthiSpher-S, commonly used for the production of biologicals by animal cells). Insulin release studies in response to glucose were performed within 1 week and after 1 month from preparation of the varying systems and showed no capability of dispersed bovine islet cells within sodium alginate microcapsules to sense glucose concentration changes. On the contrary, bovine islet cells entrapped in CulthiSpher-S microcarriers showed maintained capacity of increasing insulin secretion upon enhanced glucose concentration challenge. In this case, insulin release was approximately 60% of that from intact bovine islets within sodium alginate microcapsules. MTT and hematoxylineosin staining of islet cell-containing microcarriers showed the presence of viable and metabolically active cells throughout the study period. This encouraging functional data prompted us to test whether the microcarriers could be immunoisolated for potential use in transplantation. The microcarriers were embedded within 3% sodium alginate, which was then covered with a poly-L-lysine layer and a final outer alginate layer. Maintained insulin secretion function of this system was observed, which raises the possibility of using microencapsulated CulthiSpher-S microcarriers, containing dispersed pancreatic islet cells, in experimental transplantation studies.
...
PMID:Entrapment of dispersed pancreatic islet cells in CultiSpher-S macroporous gelatin microcarriers: Preparation, in vitro characterization, and microencapsulation. 1174 53

OBJECTIVE: To investigate the effects of simvastatin on the proliferation of rat cardiac fibroblasts (CFs) induced by arginine vasopressin (AVP). METHODS: CFs of neonatal Sprague-Dawley (SD) rats were isolated by trypsin digestion method and growth-arrested CFs were stimulated with 1x10-7 mol/L AVP in the presence of simvastatin (Sim) with varied concentrations. MTT assay was employed to measure CFs proliferation and determine the cell number, and the cell cycle distribution was determined with flow cytometer (FCM). RESULTS: With the increase of Sim concentration, D490 of CFs as shown by MTT assay gradually decreased, and for the cells treated with 1x10-6 mol/L Sim or 1x10-5 mol/L Sim, D490 (0.215+/-0.041and 0.163+/-0.018, respectively) was significantly lower than that of the control (0.939+/-0.048, P<0.01). In a dose-dependent manner, Sim decreased the cell percentage at S stage and the proliferation index (PI) as its concentration increased, but acted to the contrary effect with the percentage of cells at G0/G1 stage, and in CFs treated with 1x10-5 mol/L or 1x10-6 mol/l Sim, the 3 parameters were significantly different from those measured in the CFs with 1x10-7 mol/L AVP treatment (P<0.01). CONCLUSION: The results indicate that Sim can inhibit the proliferation of CFs induced by AVP, possibly through the mechanism of regulating the cell cycle distribution.
...
PMID:Effect of simvastatin on the proliferation of rat cardiac fibroblasts. 1242 66

A homodimeric trypsin inhibitor with a molecular mass of 54 kDa was isolated from the seeds of Clausena lansium (Lour) Skeels with a very simple procedure comprising extraction with an aqueous buffer and ion exchange chromatography on CM-cellulose. It inhibited trypsin with an IC50 of 2.2 nM but was without any inhibitory effect on chymotrypsin and proteinase K. The uptake of MTT by human leukemia HL60 and hepatoma Hep G2 cells was inhibited with an IC50 of 100 microM. Translation in the cell-free rabbit reticulocyte lysate system was inhibited with an IC50 of 3.6 microM. The activity of HIV-1 reverse transcriptase was reduced in the presence of the trypsin inhibitor. The trypsin inhibitor exerted antifungal activity toward Physalospora piricola but not Mycosphaerella arachidicola, Botrytis cinerea, Fusarium oxysporum or Coprinus comatus.
...
PMID:A homodimeric sporamin-type trypsin inhibitor with antiproliferative, HIV reverse transcriptase-inhibitory and antifungal activities from wampee (Clausena lansium) seeds. 1267 22

The female sex hormones estrogen and progesterone stimulate proliferation and differentiation of human and rodent uterine cells. The purpose of this chapter is to provide a method for isolating hormone-responsive rat uterine stromal cell lines that can be used to study steroid control of the cell cycle. Uteri from ovariectomized rats are differentially digested with trypsin to separate epithelial and stromal cells. The stromal cells are cultured in a standard growth medium containing 10% fetal bovine serum. After several passages, the purity of the stromal cell lines is determined using immunocytochemistry. Cell proliferation is studied by culturing the stromal cells in serum-free medium containing sex steroids and other mitogens. Cell cycle progression is assessed by flow cytometry, 3H-thymidine and BrdU incorporation, whereas proliferation is monitored using the MTT assay. Cell cycle regulators are visualized by Northern and Western blotting whereas cyclin-cyclin-dependent kinase activity is monitored using immune complex kinase assays. Uterine stromal cell lines isolated using the methods reported in this chapter provide a suitable model system to investigate the signal transduction events that stimulate hormone-dependent control of the cell cycle.
...
PMID:Isolation of hormone responsive uterine stromal cells: an in vitro model for stromal cell proliferation and differentiation. 1625 33


1 2 3 4 5 6 7 Next >>

---