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BMC Cell Biology Apr 2011Hepatoma-derived growth factor (HDGF) is a nuclear protein that is a mitogen for a wide variety of cells. Mass spectrometry based methods have identified HDGF as a...
BACKGROUND
Hepatoma-derived growth factor (HDGF) is a nuclear protein that is a mitogen for a wide variety of cells. Mass spectrometry based methods have identified HDGF as a phosphoprotein without validation or a functional consequence of this post-translational modification.
RESULTS
We found that HDGF in primary mouse aortic vascular smooth muscle cells (VSMC) was phosphorylated. Wild type HDGF was phosphorylated in asynchronous cells and substitution of S103, S165 and S202 to alanine each demonstrated a decrease in HDGF phosphorylation. A phospho-S103 HDGF specific antibody was developed and demonstrated mitosis-specific phosphorylation. HDGF-S103A was not mitogenic and FACS analysis demonstrated a G2/M arrest in HDGF-S103A expressing cells, whereas cells expressing HDGF-S103D showed cell cycle progression. Nocodazole arrest increased S103 phosphorylation from 1.6% to 29% (P = 0.037).
CONCLUSIONS
Thus, HDGF is a phosphoprotein and phosphorylation of S103 is mitosis related and required for its function as a mitogen. We speculate that cell cycle regulated phosphorylation of HDGF may play an important role in vascular cell proliferation.
Topics: Amino Acid Motifs; Animals; Cell Line; Humans; Intercellular Signaling Peptides and Proteins; Mice; Mitogens; Mitosis; Phosphorylation; Rats
PubMed: 21489262
DOI: 10.1186/1471-2121-12-15 -
Diabetologia Sep 2011The molecular safety of insulin analogues has received a great deal of attention over the last year. In particular, attention has been directed to the mitogenic... (Review)
Review
The molecular safety of insulin analogues has received a great deal of attention over the last year. In particular, attention has been directed to the mitogenic properties of insulin analogues as compared with human insulin. Understanding the mechanisms implicated in mediating mitogenic effects of insulin is therefore of particular interest. In this review we detail the story of the rapid-acting insulin analogue known as X10, which was the first insulin analogue in clinical development, but ended up being discontinued at an early clinical development stage following findings of mammary tumours in female Sprague-Dawley rats. The molecular characteristics of insulin X10, along with its interaction at both the IGF-1 receptor and the insulin receptor, have provided us with important insights into mechanisms implicated in metabolic and mitogenic signalling of insulin analogues.
Topics: Animals; Diabetes Mellitus; Disease Models, Animal; Female; Humans; Insulin; Insulin, Short-Acting; Mammary Neoplasms, Experimental; Mitogens; Rats; Rats, Sprague-Dawley; Receptor, IGF Type 1; Receptor, Insulin
PubMed: 21633908
DOI: 10.1007/s00125-011-2203-8 -
Journal of Neuroscience Research Aug 1995The proliferation of neonatal Schwann cells (SCs) in response to mitogenic agents has been well analyzed in vitro, but a limited range of mitogens have been defined. We...
The proliferation of neonatal Schwann cells (SCs) in response to mitogenic agents has been well analyzed in vitro, but a limited range of mitogens have been defined. We investigated whether three identified neonatal SC mitogens [glial growth factor (GGF), platelet-derived growth factor BB (PDGF-BB), and basic fibroblast growth factor (bFGF)] are required to stimulate mitosis of adult SCs. Adult SCs were isolated from mouse sciatic nerves by mechanical and chemical dissociation, following three experimental steps: 1) culturing the dissociated cells for 24 hr in 10% FCS-F12 medium, 2) culturing these cells in serum-free medium for the next 48 hr, and 3) purifying adult SCs by differential adhesion. We describe a new method for preparation of SCs from peripheral nerves of adult mouse that provides 99.5% pure SCs populations at cell yields of greater than 3 x 10(3) cells/mg of starting nerve wet weight within 5 culture days. Although mitosis of SCs in culture in response to mitogens requires the presence of serum, the complex nature of serum renders difficult a complete analysis of mitogens required for SCs DNA synthesis, so we examined the proliferating response of adult SCs to GGF, PDGF-BB, and bFGF in serum-free medium. GGF alone had mitogenicity for adult SCs in a dose-dependent manner, and synergistic activation coupling with forskolin was not observed. Neither PDGF-BB nor bFGF was mitogenic for adult SCs when used alone or with forskolin.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Aging; Animals; Cell Division; Cell Separation; Cells, Cultured; Culture Media, Serum-Free; Cyclic AMP; Immunohistochemistry; Intracellular Membranes; Mice; Mice, Inbred C57BL; Mitogens; Schwann Cells
PubMed: 7563245
DOI: 10.1002/jnr.490410511 -
Nature Medicine Aug 2000Lymphocyte polyclonal activation is a generalized mechanism of immune evasion among pathogens. In a mouse model of Trypanosoma cruzi infection (American...
Lymphocyte polyclonal activation is a generalized mechanism of immune evasion among pathogens. In a mouse model of Trypanosoma cruzi infection (American trypanosomiasis), reduced levels of polyclonal lymphocyte responses correlate with resistance to infection and cardiopathy. We report here the characterization of a parasite protein with B-cell mitogenic properties in culture supernatants of infective forms, the cloning of the corresponding gene and the analysis of the biological properties of its product. We characterized the protein as a co-factor-independent proline racemase, and show that its expression as a cytoplasmic and/or membrane-associated protein is life-stage specific. Inhibition studies indicate that availability of the racemase active site is necessary for mitogenic activity. This is the first report to our knowledge of a eukaryotic amino acid racemase gene. Our findings have potential consequences for the development of new immune therapies and drug design against pathogens.
Topics: Amino Acid Isomerases; Amino Acid Sequence; Animals; B-Lymphocytes; Base Sequence; Cloning, Molecular; DNA Primers; Genes, Protozoan; In Vitro Techniques; Lymphocyte Activation; Mice; Mitogens; Molecular Sequence Data; Molecular Weight; Sequence Homology, Amino Acid; Trypanosoma cruzi
PubMed: 10932226
DOI: 10.1038/78651 -
Fertility and Sterility Nov 1991To characterize the presence of mitogen(s) in the peritoneal fluid (PF).
OBJECTIVE
To characterize the presence of mitogen(s) in the peritoneal fluid (PF).
DESIGN
Aliquots of PF aspirated at laparoscopy were assessed for mitogenic activity by the rate of [3H]-thymidine incorporation into the deoxyribonucleic acid of various cell lines.
SETTING
Peritoneal fluids were obtained from patients having a laparoscopy for the investigation of infertility or pelvic pain or for tubal ligation.
PATIENTS
Seven women with laparoscopic evidence of endometriosis (stage I and II) and six without evidence of endometriosis.
INTERVENTION
None.
MAIN OUTCOME MEASURE
After 24 hours of culture in absence of serum, NIH/3T3 mouse embryo fibroblasts, (KLE) human endometrial adenocarcinoma cells, and primary cultures of rabbit endometrial cells were incubated in the presence of appropriate amounts of PF or bovine serum albumin (control) for 22 hours before adding the [3H]-thymidine for 2 hours.
RESULTS
Aliquots of PF containing greater than 100 micrograms/mL total protein concentration stimulated the proliferation of all cell types. This mitogenic effect was dose-dependent and was greatest on endometrial-like cells. The mitogenic activity was fully recovered after adsorption on dextran-coated charcoal and was sensitive to tryptic digestion and to heat. It could not be retained on cartridge of C18 silica and was calculated to have a molecular weight greater than 30,000 by gel permeation chromatography.
CONCLUSIONS
Peritoneal fluid from women with or without endometriosis contain growth factor(s) that are proteinaceous in nature and capable of stimulating the proliferation of endometrial-like cells and fibroblasts. These mitogens could play a role in the pathogenesis of endometriosis.
Topics: Animals; Ascitic Fluid; Chromatography, Gel; DNA; Dose-Response Relationship, Drug; Endometriosis; Endometrium; Female; Humans; Mitogens; Molecular Weight; Thymidine
PubMed: 1936323
DOI: 10.1016/s0015-0282(16)54660-3 -
Science (New York, N.Y.) May 1982Mitogenic stimulation of mouse lymphocytes results in two sequential intracellular alkalinizations. The first shift of intracellular pH from 7.18 to 7.35 coincides with...
Mitogenic stimulation of mouse lymphocytes results in two sequential intracellular alkalinizations. The first shift of intracellular pH from 7.18 to 7.35 coincides with early biochemical events following mitogenic stimulation. The second alkalinization begins 12 hours after stimulation and rises in parallel with the rate of thymidine incorporation. The results suggest that intracellular alkalinization following stimulation may play a key role in the enhancement of cellular activation and mitogenesis.
Topics: Animals; B-Lymphocytes; DNA Replication; Hydrogen-Ion Concentration; Lymphocyte Activation; Lymphocytes; Mice; Mitogens; Phosphotransferases; Spleen; T-Lymphocytes; Time Factors
PubMed: 6281887
DOI: 10.1126/science.6281887 -
Drug Metabolism Reviews 1992While lead acetate is a renal carcinogen in rodent studies, the mechanism by which it induces cancer has not been established. This report proposes that the enhanced... (Review)
Review
While lead acetate is a renal carcinogen in rodent studies, the mechanism by which it induces cancer has not been established. This report proposes that the enhanced susceptibility of renal tubular epithelial cells to lead-induced mitogenicity at the levels comparable to those administered in the cancer bioassay may contribute to the carcinogenic response seen in this target organ. Of relevance is that the nonresponsiveness of the liver to lead-induced carcinogenicity was associated with significantly less capacity (i.e., 675-fold) of lead to induce the mitogenic response in the rodent liver.
Topics: Animals; Cell Division; Kidney Neoplasms; Kidney Tubules; Lead; Liver; Liver Neoplasms; Mitogens; Organ Specificity
PubMed: 1628538
DOI: 10.3109/03602539208996299 -
Journal of Neuroscience Research Mar 1989Treatment of axolemma with pH 9 buffer results in a pellet enriched two-fold in the mitogen for cultured Schwann cells. Heparitinase treatment releases 8% of the mitogen...
Treatment of axolemma with pH 9 buffer results in a pellet enriched two-fold in the mitogen for cultured Schwann cells. Heparitinase treatment releases 8% of the mitogen into solution, while heparin selectively solubilizes the mitogen, resulting in an extract which has a specific mitogenic activity approximately 2.5 times greater than the mitogenicity of the starting axolemma membrane. These data support a model in which the axolemmal mitogen is a positively charged molecule associated with negatively charged sulfated proteoglycans.
Topics: Animals; Axons; Brain Stem; Cell Division; Cells, Cultured; Chondroitin Sulfate Proteoglycans; Glycosaminoglycans; Heparan Sulfate Proteoglycans; Heparin; Heparitin Sulfate; Mitogens; Proteoglycans; Rats; Schwann Cells
PubMed: 2523488
DOI: 10.1002/jnr.490220308 -
The Journal of Infectious Diseases May 1980Slime glycolipoprotein of Pseudomonas aeruginosa has been found to exert a mitogenic effect on human peripheral blood and cord blood lymphocytes. The optimal...
Slime glycolipoprotein of Pseudomonas aeruginosa has been found to exert a mitogenic effect on human peripheral blood and cord blood lymphocytes. The optimal concentration of glycolipoprotein was shown to be in the range of 100--200 micrograms/ml, and maximal incorporation of [14C]thymidine was seen on the fourth day of lymphocyte cultures.
Topics: Fetal Blood; Glycoproteins; Humans; Lymphocyte Activation; Lymphocytes; Mitogens; Pseudomonas Infections; Pseudomonas aeruginosa; Thymidine
PubMed: 6768815
DOI: 10.1093/infdis/141.5.686 -
Arthritis and Rheumatism Apr 1992Mycoplasma arthritidis mitogen (MAM) is mitogenic for mouse, rat, and human T cells, and behaves as a superantigen in mice through its capacity to bind to the alpha...
OBJECTIVE
Mycoplasma arthritidis mitogen (MAM) is mitogenic for mouse, rat, and human T cells, and behaves as a superantigen in mice through its capacity to bind to the alpha chain of I-E molecules and engage entire sets of T cells expressing specific V beta. Here, we have attempted to fully characterize the V beta-engaging activities of MAM in mice, and define similar activities in rats and humans.
METHODS
Multiprobe RNase-protection assays and mice transgenic for human DR alpha, DR beta, and DR alpha beta were utilized for this purpose.
RESULTS
MAM-reactive V beta in the mouse included not only the previously reported V beta 6, V beta 8.1, V beta 8.2, and V beta 8.3, but also V beta 5.1. In the rat, engagement of V beta 5.1, V beta 6, V beta 8.1, and V beta 8.2, but not V beta 8.3, was documented, whereas in humans, the engaged V beta included primarily V beta 19.1 (alternatively termed V beta 17.1) and, to a lesser extent, V beta 3.1, V beta 11.1, V beta 12.1, and V beta 13.1. In DR transgenic E alpha- E beta- mice, presentation of MAM and engagement of specific V beta was effected by DR alpha.
CONCLUSIONS
Homologous V beta are engaged by MAM in mice, rats, and humans, presumably through a binding site similar to that proposed previously for other superantigens. MAM presentation primarily via the nonpolymorphic DR alpha makes it unlikely that there is involvement of such a superantigen in the pathogenesis of autoimmune diseases known to be associated with certain DR haplotypes. The possibility cannot be excluded, however, that superantigen-activated T cells may lead to disease by cross-reactions with self-antigens presented by particular DR haplotypes.
Topics: Amino Acid Sequence; Animals; Antigens; Antigens, Bacterial; Binding Sites; HLA-DR Antigens; Humans; Immunoglobulin Variable Region; Mice; Mice, Inbred CBA; Mitogens; Molecular Sequence Data; Proteins; Rats; Rats, Inbred Lew; Receptors, Antigen, T-Cell, alpha-beta; Superantigens
PubMed: 1533125
DOI: 10.1002/art.1780350413