One of the early events after stimulation of Swiss 3T3 cells with either platelet-derived growth factor (PDGF), 12-O-tetradecanoyl-phorbol-13-acetate (TPA), diacylglycerol, or several other mitogens is the near stoichiometric phosphorylation at tyrosine and serine of a scarce cytoplasmic protein (p42). TPA and diacylglycerol are known to directly stimulate the activity of a protein-serine/threo...

An in vitro cell-mediated immune response to pokeweed mitogen (PWM) is described. Rat lymphocytes were stimulated by PWM, by phytohemagglutinin (PHA), and by concanavalin A (ConA). In the presence of PWM only a fraction of the lymphocytes underwent blastogenesis. This was in contrast to the apparent total blastogenesis obtained in response to PHA or ConA. When blast cells derived from each of t...

To study the effect of the mitogens epidermal growth factor (EGF), acidic and basic fibroblast growth factors (aFGF and bFGF), and vasopressin on brown adipocyte differentiation, we analyzed the expression of uncoupling protein-1 (UCP-1) mRNA. Quiescent brown preadipocytes express high levels of UCP-1 mRNA in response to triiodothyronine (T3) and norepinephrine (NE). The addition of serum or th...

Myogenic differentiation in vitro has been usually viewed as being negatively controlled by serum mitogens. A depletion of critical serum components from medium has been considered to be essential for permanent withdrawal from the cell cycle and terminal differentiation of myoblasts. Removal of serum mitogens induces the expression of insulin-like growth factors (IGFs), whereas it inhibits that...

been arranged so as to present their results in the context of a general review and presentation of the current status of each particular subject. For this reason, this book should be useful not only to the specialist, but also to those who are entering this field. The book first considers the nature and biochemistry of lymphocyte activating agents and then presents the current status of the kn...

Cell transplantation to treat retinal degenerative diseases represents an option for the replacement of lost photoreceptor cells. In vitro expandable cells isolated from the developing mammalian retina have been suggested as a potential source for the generation of high numbers of donor photoreceptors. In this study we used standardized culture conditions based on the presence of the mitogens F...

CD3-4-8- and unfractionated thymocytes were compared for their capacity to proliferate, to express interleukin 2 (IL-2) receptor, and to secret IL-2. Phorbol ester and Ca2+ ionophore were used as mitogens. CD3-4-8- thymocytes responded vigorously when stimulated with phorbol ester in the presence of IL-2 or in combination with Ca2+ ionophore. In contrast, unfractionated thymocytes responded wea...

Group A streptococcal pyrogenic exotoxins types A, B, and C and staphylococcal pyrogenic exotoxin were shown to be potent nonspecific T-lymphocyte mitogens. Adherent cell populations did not significantly affect the nonspecific mitogenicity.

When lymphocytes purified from peripheral blood are incubated with mitogenic lectins such as phytohaemagglutinin they initiate DNA synthesis, but only after a lag of about 24 h. There are, however, substantial changes in many aspects of lymphocyte metabolism which begin much more rapidly after lectin addition, and these include large increases in the rates of transcription and translation (Ling...

Cells generate new organelles when stimulated by extracellular factors to grow and divide; however, little is known about how growth and mitogenic signalling pathways regulate organelle biogenesis. Using mitochondria as a model organelle, we have investigated this problem in primary Schwann cells, for which distinct factors act solely as mitogens (neuregulin) or as promoters of cell growth (ins...