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1.
Seyed Sajad Mohseni Salehi Monfared Shirin Pournourmohammadi 《Biological trace element research》2010,133(2):236-241
Islet transplantation has become a promising treatment in the therapy of type 1 diabetes. Its function improvement, after
isolation and before transplantation, is crucial because of their loss both in number and function of islets after isolation
procedures. Trace elements sodium orthovanadate (SOV) and sodium molybdate (SM), as well as medicinal plant Teucrium polium L. (TP), showed and possessed high beneficial antioxidative potential and even hypoglycemic properties via their effect on
islets. We evaluated the effect of these components in combination on cultured islet function in order to improve pancreatic
islet transplantation. Rat pancreatic islets were cultured for 24 h then incubated with different concentrations of TP (0.01
and 0.1 mg/mL) alone and in combination with SOV (1 mM) or SM (1 mM). Insulin concentration in buffer media was measured as
islet secretory function. Administration of TP (0.01 mg/mL), SM, and SOV alone or in combination with each other significantly
increased insulin secretion at high glucose concentration (16.7 mM); insulin secretion was significantly greater in the group
containing both TP and SM than other treated groups (p < 0.05). The combination of the mentioned trace elements especially molybdate with TP could improve islet cells function before
transplantation. 相似文献
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The conformation of reduced bovine pancreatic trypsin inhibitor (R-BPTI) under reducing conditions was monitored by measurements of nonradiative excitation energy-transfer efficiencies (E) between a donor probe attached to the N-terminal Arg1 residue and an acceptor attached to one of the lysine residues (15, 26, 41, or 46) [Amir, D., & Haas, E. (1987) Biochemistry 26, 2162-2175]. High-excitation energy-transfer efficiencies that approach those found in the native state were obtained for the reduced labeled BPTI derivatives in 0.5 M guanidine hydrochloride (Gdn.HCl) and 4 mM DTT. Unlike the dependence expected for a random coil chain, E does not decrease as a function of the number of residues between the labeled sites. The efficiency of energy transfer between probes attached to residues 1 and 15 in the reduced state is higher than that found for the same pair of sites in the native state or reduced unfolded (in 6 M Gdn.HCl) state. This segment also shows high dynamic flexibility. These results indicate that the overall structure of reduced BPTI under folding (but still reducing) conditions shows a high population of conformers with interprobe distances similar to those of the native state. Reduced BPTI seems to be in a molten globule state characterized by a flexible, compact structure, which probably reorganizes into the native structure when the folding is allowed to proceed under oxidizing conditions. 相似文献
5.
Control of K+ influx in 3T3 cells transformed by a conditional mutant of Rous sarcoma virus 总被引:1,自引:0,他引:1
Mouse 3T3 cells transformed by a conditional mutant of Rous sarcoma virus (LA90) can assume either a normal or a transformed phenotype, depending on the temperature of cultivation. These cells (LA90) were arrested at the G0/G1 phase of the cell cycle by starvation for serum growth factors at the nonpermissive temperature (39 degrees C). Release from the G0/G1 phase by serum growth factors resulted in a rapid stimulation of Rb+ influx. To investigate whether the stimulation of Rb+ influx is obligatory for cell proliferation, the cultures were released from the G0/G1 phase by a temperature decrease in the absence of serum. A temperature decrease from 39 to 32 degrees C activated the viral pp60src gene mitogenic activity. Under these conditions, no rapid stimulation of Rb+ influx was observed. These results suggest that the rapid stimulation of Rb+ influx induced by serum growth factors is not an essential signal for cell release from the G0/G1 phase. However, a delayed increase in Rb+ influx concomitant with an increase in the cell content of K+ was observed in the cultures released from the G0/G1 phase by temperature decrease in the absence of serum growth factors. We found that the LA90 cells incubated at the permissive temperature (32 degrees C) secreted a mitogenic activity into the medium. Moreover, the conditioned medium from cultures incubated at 32 degrees C, but not at 39 degrees C, stimulate Rb+ influx in G0/G1 cells. These results indicate that Rous sarcoma virus pp60src induces a slow autocrine secretion of a mitogenic activity. This mitogenic activity slowly modulates the K+ content. Therefore, the slow elevation in cellular content of K+ is proposed to be an obligatory event for proliferation in normal and transformed cells. 相似文献
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Seyede Saba Hosseini Seyed Omar Ebrahimi Maryam Haji Ghasem Kashani Somayeh Reiisi 《Cell biology international》2023,47(1):98-109
Naturally-derived drugs have drawn much attention in recent decades. Efficiency, lower toxicity, and economic reasons are some of their advantages that justify this broad range of administration for different diseases, including cancer. If we can find a specific combination that boosts the effects of their single therapy, leading to synergism effect, increased efficiency, and decreased toxicity, they can act even better. Quercetin and fisetin, two well-known flavonoids, have been used to fight against various cancers. In this study, we investigated their possible synergism quercetin and fisetin on MCF7, MDA-MB-231, BT549, T47D, and 4T1 breast cancer cell lines. Then the optimum combined dose was used to study their impacts on wound healing abilities and clonogenic properties. The real-time qPCR was used to study the expression of their validated downstream effectors in predicted pathways. A significant synergism effect (p < .01, combination index: <1) was observed for all cell lines. Combination therapy was significantly more effective in colony formation (p < .0001) and wound healing assays (p < .001) compared to single therapies. The expression level of potential effectors was also showed a greater change. In vivo study confirmed the in vitro results and showed how significantly (p < .001) their synergism promotes their singular function in inhibiting cancer progression. The breast cancer mouse models receiving combined therapy lived longer with higher average body weight and smaller tumor sizes. These results exhibit that quercetin and fisetin inhibit cancer cell proliferation, migration and colony formation synergistically, and matrix metalloproteinase signaling and apoptotic pathways are relatively responsible for inhibitory activities. 相似文献
8.
Diana Villegas-Coronado Jesús Adriana Soto-Guzman Juan Manuel Martínez-Soto Nayelli Guadalupe Teran-Saavedra Ana Maria Guzman-Partida Luz Vazquez-Moreno Ana Gloria Villalba-Villalba Amir Maldonado Irlanda Lagarda-Diaz 《化学与生物多样性》2023,20(7):e202300051
Acute monocytic leukemia is a type of myeloid leukemia that develops in monocytes. The current clinical therapies for leukemia are unsatisfactory due to their side effects and nonspecificity toward target cells. Some lectins display antitumor activity and may specifically recognize cancer cells by binding to carbohydrate structures on their surface. Therefore, this study evaluated the response of the human monocytic leukemia cell lines THP-1 to the Olneya tesota PF2 lectin. The induction of apoptosis and reactive oxygen species production in PF2-treated cells was evaluated by flow cytometry, and the lectin-THP-1 cell interaction and mitochondrial membrane potential were evaluated by confocal fluorescence microscopy. PF2 genotoxicity was evaluated by DNA fragmentation analysis via gel electrophoresis. The results showed that PF2 binds to THP-1 cells, triggers apoptosis and DNA degradation, changes the mitochondrial membrane potential, and increases reactive oxygen species levels in PF2-treated THP-1 cells. These results suggest the potential use of PF2 for developing alternative anticancer treatments with enhanced specificity. 相似文献
9.
Bret B. Wagenhorst Ramji R. Rajendran Ellen E. Van Niel Richard B. Hessler Amir Bukelman Federico Gonzalez-Fernandez 《Journal of molecular evolution》1995,41(5):646-656
Vitamin A and fatty acids are critical to photoreceptor structure, function, and development. The transport of these nutrients between the pigment epithelium and neural retina is mediated by interphotoreceptor retinoid-binding protein (IRBP). IRBP, a 133-kDa (human) glycolipoprotein, is the major protein component of the extracellular matrix separating these two cell layers. In amphibians and mammals, IRBP consists of four homologous repeats of about 300 amino acids which form two retinol and four fatty acid-binding sites. Here we show that IRBP in teleosts is a simpler protein composed of only two repeats. Western blot analysis shows that goldfish IRBP is half the size (70 kDa) of IRBP in higher vertebrates. Metabolic labeling studies employing Brefeldin A taken together with in situ hybridization studies and the presence of a signal peptide show that goldfish IRBP is secreted by the cone photoreceptors. The translated amino acid sequence has a calculated molecular weight of 66.7 kDa. The primary structure consists of only two homologous repeats with a similarity score of 52.5%. The last repeats of human and goldfish IRBPs are 69.1% similar with hydrophobic regions being the most similar. These data suggest that two repeats were lost during the evolution of the ray-finned fish (Actinopterygii), or that the IRBP gene duplicated between the emergence of bony fish (Osteichthyes) and amphibians. Acquisition of a multirepeat structure may reflect evolutionary pressure to efficiently transport higher levels of hydrophobic molecules within a finite space. Quadruplication of an ancestral IRBP gene may have been an important event in the evolution of photoreceptors in higher vertebrates.
Correspondence to: F. Gonzalez-Fernandez 相似文献
10.
A kinetic study was made of the relationship between respiration rate, sugar content and ATP levels, in fresh and aged potato tubers stored at 4°. The ATP content in tubers rose rapidly immediately after the chilling stress, while respiration rate decreased below the initial rate and sugar accumulation was not detected. After 4 days of storage, the ATP level declined and the sugars started to accumulate. The typical increase in respiration rate that usually follows chilling stress, appeared only in fresh tubers (at about the 6th day of storage). In dinitrophenol-treated tubers, the ATP level remained below the initial level and sugar accumulation was blocked completely. The evidence presented suggests that ATP elevation is not generated by the respiration burst. 相似文献