Tumor-promoting phorbol esters stimulate the proliferation of interleukin-3 dependent cells

To determine whether activation of protein kinase C is involved in the proliferation of interleukin-3 (IL-3) -dependent cells, we examined the effect of tumor-promoting phorbol esters on the in vitro proliferation of the IL-3-dependent cell lines FD and DA-1. The viability of FD and DA-1 cells cultured for 24 hours in 100 nM phorbol myristate acetate (PMA) and 10% FCS was similar to that of cells cultured in 25% WEHI-3 conditioned medium as a source of IL-3, and 10% FCS. FD cells failed to proliferate in concentrations of FCS of up to 50%, while DA-1 cell proliferation was not markedly influenced by FCS. By contrast, PMA promoted the proliferation of FD and DA-1 cells in the absence of FCS and enhanced their proliferation in the presence of 10% FCS, 60- and 20-fold, respectively. Stimulation of proliferation was achieved with as little as 10 nM PMA and was maximal at 100 nM PMA. Low concentrations (0.05-0.1%) of WEHI-3 CM promoted the proliferative response of FD and DA-1 cells to PMA, but at concentrations of WEHI-3 CM greater than 0.8%, no further increment in proliferation was obtained with PMA. As little as 1/2 hour of exposure to phorbol esters was sufficient to cause translocation of protein kinase C from the cytosol to the membranes of DA-1 cells, and 1 hour of exposure to phorbol esters was sufficient to stimulate DNA synthesis. A protein kinase C inhibitor, H-7, at a concentration of 10 microM inhibited phorbol ester-induced stimulation of DA-1 cell proliferation. When DA-1 cells were exposed to the calcium ionophore A23187 in addition to both a phorbol ester and IL-3, their proliferation was enhanced over that stimulated by only the phorbol ester and IL-3. The data indicate that stimulation of proliferation of IL-3-dependent cells involves the activation of protein kinase C.     

Effect of interferon on the course of experimental E coli-induced pyelonephritis

The effect of the type I interferon on the development and process of experimental pyelonephritis caused by E. coli was studied on mice weighing 12 to 14 g. Interferon was administered intraperitoneally in a dose of 1000 units on days 3 and 7 of the disease. It was shown that the administration of the type I interferon to the mice with experimental pyelonephritis promoted rapid elimination of bacteria from the kidneys, prevented their penetration to the contralateral (intact) kidney, prevented marked macro- and microscopic damages in the kidneys, lowered the intensity of the inflammatory reaction, and increased the phagocytic activity of neutrophils and the number of the E-rosette-forming lymphocytes in the thymus. The data provided experimental grounding for clinical trials of interferon preparations in treatment of bacterial pyelonephritis.     

Relationship between radiation induced adaptive response in human fibroblasts and changes in chromatin conformation

Chromatin conformation changes in the normal human fibroblasts VH-10 were studied by the method of anomalous viscosity time dependence (AVTD). Gamma-irradiation of cells in a dose range of 0.1–3 Gy caused an increase in maximal viscosity of cell lysates. Conversely, irradiation of cells with low doses of 0.5 or 2 cGy resulted in a decrease in the AVTD peaks with a maximum effect approximately 40 min after irradiation. The same exposure conditions were used to study a possible adaptive effect of low doses, measured by changes in cell survival. A primary dose of 2 cGy caused significant modification of cell response to a challenge dose. Approximately 20% protection to challenge doses of 0.5 Gy (p < 0.003), 2 Gy (p < 0.02) and 2.5 Gy (p < 0.002) was observed. However, the direction of this effect (adaptation or synergism) was found to be dependent on a challenge dose. The combined effect of 2 cGy and 1 Gy was significantly synergistic, while no modification was observed for 1.5 Gy and 3 Gy. A partial correlation was found between the AVTD changes and cell survival when the combined effect of a primary dose of 2 cGy and challenge dose was examined. The dose of 2 cGy alone increased survival by 16% (p < 0.0003). These results suggest that the low-dose induced effects on survival may be related to chromatin reorganization.     

Chromosomal protein synthesis during erythropoiesis in the mouse spleen

Induced erythropoiesis in the mouse spleen was employed to study chromosomal protein synthesis during erythroid cell development. Splenic erythropoiesis occurring after phenylhydrazine induced hemolysis can be divided into an early phase during which nuclear RNA polymerase activity and RNA production are maximal and a late phase in which hemoglobin synthesis and DNA accumulation are maximal. Chromatin was isolated from splenic tissue during both the early and late phases of erythropoiesis as well as from non-anemic animals. The total protein content of chromatin from the early erythroid phase was greater than that of chromatin from the late erythroid phase or from non-anemic controls. The increase was due to a coordinate increase in the concentration of both histone and nonhistone proteins. During late erythropoiesis, the concentration of each returned to pre-anemic levels. Total histone synthesis increased 2.6-fold during early erythropoiesis as compared with the pre-anemic state and remained elevated in late erythropoiesis. The increase in histone synthesis was due to an increase in the synthesis of all five major histone proteins. Nonhistone protein synthesis was more active than that of histones in the pre-anemic spleen and rose only slightly during early erythropoiesis, returning to preanemic levels during late erythropoiesis. Fractionation of nonhistone proteins on SDS-urea polyacrylamide gels revealed complex patterns with significant differences between the pattern of erythroid spleen non-histone proteins and that of the pre-anemic spleen. Analysis of the incorporation of ³H-valine into the non-histone proteins indicated that during early erythropoiesis there was a generalized increase in nonhistone protein synthesis. During the late erythroid phase, the decline in non-histone protein synthesis was most marked for the higher molecular weight proteins.     

Reconstitution of an active calcium pump in sarcoplasmic reticulum.

Recovery of calcium transport and calcium-activated ATPase activity was studied in relation to the retention of protein components in sarcoplasmic reticulum reconstituted after solubilization with deoxycholate and centrifugation, followed by removal of the detergent from the supernatant by dialysis. Control sarcoplasmic reticulum was similarly treated except for omission of deoxycholate. Maximum capacity for oxalate- and phosphate-supported calcium uptake was increased 2- to 3-fold in reconstituted sarcoplasmic reticulum compared to original and control. Calcium uptake velocity of the reconstituted sarcoplasmic reticulum was approximately 80% that of original and 90% of control sarcoplasmic reticulum. Calcium uptake/ATP hydrolysis ratio was approximately 2 in the original sarcoplasmic reticulum and decreased to approximately 1 in the control and reconstituted sarcoplasmic reticulum. Calcium storage in the absence of calcium-precipitating anion was approximately 85% in control and 70% in reconstituted sarcoplasmic reticulum, compared to the original sarcoplasmic reticulum. Ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid-induced calcium release after phosphate-supported calcium uptake was slower in reconstituted sarcoplasmic reticulum than in original or control sarcoplasmic reticulum. Polyacrylamide gel electrophoresis of original and control sarcoplasmic reticulum showed similar amounts of protein components of approximately 93,000, 59,000, 50,000, 30,000 to 37,000, and 20,000 to 26,000 daltons. Reconstituted sarcoplasmic reticulum, however, lost over 85% of the 50,000- and 20,000- to 26,000-dalton proteins while retaining most of its calcium transport functions.     

Specific features of the apoptotic response of urinary bladder cancer cells to neoadjuvant chemotherapy

The TUNEL reaction was used to study induced apoptosis in the tumor cells of urinary bladder cancer (UBC) patients. It has been shown that an increase in the values of induced apoptosis correlates well with the indicators showing a tumor’s corresponding response to the application of neoadjuvant chemotherapy, using the gemcitabine-cisplatin regimen. It has been concluded that assessing the level of induced apoptosis in UBC tumor cells using the TUNEL assay enables making a prognosis for the efficacy of chemotherapy at the single-cell level in patients with this type of cancer.     

Metabolomics Reveals the Origins of Antimicrobial Plant Resins Collected by Honey Bees

The deposition of antimicrobial plant resins in honey bee, Apis mellifera, nests has important physiological benefits. Resin foraging is difficult to approach experimentally because resin composition is highly variable among and between plant families, the environmental and plant-genotypic effects on resins are unknown, and resin foragers are relatively rare and often forage in unobservable tree canopies. Subsequently, little is known about the botanical origins of resins in many regions or the benefits of specific resins to bees. We used metabolomic methods as a type of environmental forensics to track individual resin forager behavior through comparisons of global resin metabolite patterns. The resin from the corbiculae of a single bee was sufficient to identify that resin''s botanical source without prior knowledge of resin composition. Bees from our apiary discriminately foraged for resin from eastern cottonwood (Populus deltoides), and balsam poplar (P. balsamifera) among many available, even closely related, resinous plants. Cottonwood and balsam poplar resin composition did not show significant seasonal or regional changes in composition. Metabolomic analysis of resin from 6 North American Populus spp. and 5 hybrids revealed peaks characteristic to taxonomic nodes within Populus, while antimicrobial analysis revealed that resin from different species varied in inhibition of the bee bacterial pathogen, Paenibacillus larvae. We conclude that honey bees make discrete choices among many resinous plant species, even among closely related species. Bees also maintained fidelity to a single source during a foraging trip. Furthermore, the differential inhibition of P. larvae by Populus spp., thought to be preferential for resin collection in temperate regions, suggests that resins from closely related plant species many have different benefits to bees.