Effect of yttrium ion on the proliferation,differentiation and mineralization function of primary mouse osteoblasts in vitro

A series of experimental methods including MTT test,alkaline phosphatase(ALP) activity measurement,oil red O stain and measurement and mineralized function were employed to assess the effects of Y3+ on the proliferation,differentiation,adipogenic transdifferentiation and mineralization function of primary mouse osteoblasts(OBs) in vitro.The results indicated that Y3+(1×10-9,1×10-8,1×10-7,1×10-6,1×10-5,and 1×10-4 mol/L) promoted the proliferation of OBs on day 1,2 and 3.Y3+ had no effect on the differentiati...     

Effect of cerium ion on the proliferation,differentiation and mineralization function of primary mouse osteoblasts in vitro

The effects of cerium ion(Ce3+) on the proliferation,differentiation,adipocytic transdifferentiation and mineralization function of primary mouse osteoblasts(OBs) were investigated.The results indicated that Ce3+ at all concentrations(1×10-9,1×10-8,1×10-7,1×10-6,1×10-5,and 1×10-4 mol/L) promoted the proliferation of osteoblasts(OBs).On day 1 and 3,Ce3+ promoted the differentiation of OBs at concentrations of 1×10-9,1×10-7,and 1×10-6 mol/L,but inhibited the differentiation of OBs at higher concentrations.On day 2,Ce3+ inhibited the differentiation of OBs at tested concentrations.On day 9 and 12,Ce3+ inhibited the adipocytic transdifferentiation of OBs at most concentrations.On day 15,Ce3+ promoted the adipocytic transdifferentiation of OBs at concentrations of 1×10-9,1×10-6,1×10-5,and 1×10-4 mol/L,but had no effects at other concentrations.Ce3+ inhibited the formation of mineralized matrix nodules of OBs at concentrations of 1×10-9,1×10-8 and 1×10-7 mol/L,and promoted the formation of mineralized matrix nodules of OBs at other concentrations.These findings suggested that the effects of Ce3+ on the proliferation,differentiation,adipocytic transdifferentiation and mineralization function of primary OBs depended on the concentration and culture time;moreover,they were pivotal factors for switching the biological effects of Ce3+ from toxicity to activity,from damage to protection,or from down-regulation to up-regulation.     

Polyclonal stimulation of lymphocytes by macrophages

To analyze the interaction between macrophages and splenic lymphocytes with reference to time and concentration, the Mishell-Dutton system was divided into two experimental steps. Step 1 consisted of the cocultivation of spleen cells with various doses of macrophages for different periods of time, while in step 2 macrophages were removed, spleen cells transferred to fresh petri dishes and cultivated until plaque assay. Cocultivation of spleen cells with high doses of macrophages for 4--8 h markedly enhanced the DNA synthesis and plaque-forming cell (PFC) response of sheep red blood cell-stimulated and unstimulated cultures. A cocultivation longer than 24 h resulted in an inhibition of both DNA synthesis and PFC response of spleen cells. These studies suggest a nonspecific function of macrophages on proliferation and differentiation processes in antibody formation.     

Effects of La~（3＋） on osteogenic and adipogenic differentiation of primary mouse bone marrow stromal cells

In order to elucidate the action of La3+ on bone metabolism,effects of La3+ on the osteogenic and adipogenic differentiation of pri-mary mouse bone marrow stromal cells(BMSCs) were studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) test,alkaline phosphatase(ALP) activity measurement,mineralized function,oil red O stain and measurement.The results showed that La3+ pro-moted the proliferation of BMSCs except at 1×10-10 and 1×10-6 mol/L.The effect of La3+ on the osteogenic differentiation depended on con-centrations at the 7th day,but the osteogenic differentiation was inhibited at any concentration at the 14th day.La3+ promoted the formation of mineralized matrix nodules except at 1×10-8 and 1×10-5 mol/L.La3+ inhibited adipogenic differentiation except at 1×10-10 and 1×10-7 mol/L at the 10th day,and inhibited adipogenic differentiation except at 1×10-9 mol/L at the 16th day.These findings suggested that La3+ might have protective effect on bone at appropriate dose and time.This would be valuable for better understanding the mechanism of the effect of La3+ on bone metabolism.     

cAMP stimulates osteoblast-like differentiation of calcifying vascular cells. Potential signaling pathway for vascular calcification

The role of the cAMP signaling pathway in vascular calcification was investigated using calcifying vascular cells (CVC) derived from primary aortic medial cell cultures. We previously showed that CVC have fibroblastic morphology and express several osteoblastic differentiation markers. After confluency, they aggregate into cellular condensations, which later mature into nodules where mineralization is localized. Here, we investigated the effects of cAMP on CVC differentiation because it plays a role in both osteoblastic differentiation and vascular disease. Dibutyryl-cAMP or forskolin treatment of CVC for 3 days induced osteoblast-like "cuboidal" morphology, inhibited proliferation, and enhanced alkaline phosphatase activity, all early markers of osteoblastic differentiation. Isobutylmethylxanthine and cholera toxin had the same effects. Treatment of CVC with pertussis toxin, however, did not induce the morphological change or increase alkaline phosphatase activity, although it inhibited CVC proliferation to a similar extent. cAMP also increased type I procollagen production and gene expression of matrix gamma-carboxyglutamic acid protein, recently shown to play a role in in vivo vascular calcification. cAMP inhibited the expression of osteopontin but did not affect the expression of osteocalcin and core binding factor. Prolonged cAMP treatment enhanced matrix calcium-mineral incorporation but inhibited the condensations resulting in diffuse mineralization throughout the monolayer of cells. Treatment of CVC with a protein kinase A-specific inhibitor, KT5720, inhibited alkaline phosphatase activity and mineralization during spontaneous CVC differentiation. These results suggest that the cAMP pathway promotes in vitro vascular calcification by enhancing osteoblast-like differentiation of CVC.     

Solid-liquid extraction of Gd(Ⅲ) and separphosphoric acid solutions using Tulsion C

Solid-liquid extraction of gadolinium was investigated from phosphoric acid medium using commercial amino phosphonic acid resin, Tulsion CH-93. The experimental conditions studied included equilibration time, acid concentration, mass of the resin, metal concentra-tion, loading and elution. The percent extraction of Gd(Ⅲ) was studied as a function of phosphoric acid (0.05-3 mol/L) using Tulsion CH-93 resin. The corresponding lgD vs. equilibrium pH plot gave straight line with a slope of 1.8. The percent extraction decreased with acid con-centration increasing, conforming ion exchange mechanism. Under observed experimental conditions the loading capacity of Tulsion CH-93 for gadolinium was 10.6 mg/g. Among several eluants screened, the quantitative elution of Gd(Ⅲ) from loaded Tulsion CH-93 was obtained with ammonium oxalate (0.15 mol/L). The extraction behavior of commonly associated metals with gadolinium was studied as a function of phosphoric acid concentration. Tulsion CH-93 resin showed selective extraction towards heavy rare earths (Lu and Yb) which could be sepa-rated from other rare earths at 3 mol/L H3PO4, similar to wet phosphoric acid (3-5 mol/L). On the other hand Gd(Ⅲ) and other rare earths were studied with chelating resin Tulsion CH-90. Light rare earths were highly extracted and these could be separated from heavy rare earths and Gd.)     

Antisense oligonucleotides targeted against protein kinase Cbeta and CbetaII block 1,25-(OH)2D3-induced differentiation

It is now recognized that protein kinase C (PKC) plays a critical role in 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) promotion of HL-60 cell differentiation. In this study, the effects of phosphorothioate antisense oligonucleotides directed against PKCalpha, PKCbeta, PKCbetaI, and PKCbetaII on HL-60 promyelocyte cell differentiation and proliferation were examined. Cellular differentiation was determined by nonspecific esterase activity, nitro blue tetrazolium reduction, and CD14 surface antigen expression. Differentiation promoted by 1,25-(OH)2D3 (20 nM for 48 h) was inhibited similarly in cells treated with PKCbeta antisense (30 microM) 24 h prior to or at the same time as hormone treatment (86 +/- 9% inhibition; n = 4 versus 82 +/- 8% inhibition; n = 4 (mean +/- S.E.), respectively). In contrast, cells treated with PKCbeta antisense 24 h after 1, 25-(OH)2D3 were unaffected and fully differentiated. PKCalpha antisense did not block 1,25-(OH)2D3 promotion of HL-60 cell differentiation. Next, the ability of PKCbetaI- and PKCbetaII-specific antisense oligonucleotides to block 1,25-(OH)2D3 promotion of cell differentiation was examined. PKCbetaII antisense (30 microM) completely blocked CD14 expression induced by 1, 25-(OH)2D3, whereas PKCbetaI antisense had little effect. Interestingly, PKCbetaII antisense blocked differentiation by 87 +/- 7% (n = 2, mean +/- S.D.) but had no effect on 1,25-(OH)2D3 inhibition of cellular proliferation. These results indicate that the effects of 1,25-(OH)2D3 on HL-60 cell differentiation and proliferation can be dissociated by blocking PKCbetaII expression.     

Interstitial laser-induced thermotherapy: influence of carbonization on lesion size

Growth/differentiation factor-5 (GDF-5) is a new member of the transforming growth factor-beta (TGF-beta) superfamily of multifunctional peptide growth factors that appear to mediate many key events in cell growth and development. The effects of GDF-5 and other growth factors (epidermal growth factor, EGF; TGF-beta 1) on the proliferation of human keratinocytes and fibroblasts compared with desoximetasone and calcipotriol have been investigated. The proliferation rate was determined by a hemocytometer, MTT assay and the incorporation of [3H]-thymidine. Moreover, cell cycle analyses were performed and the influence on interleukin-1 alpha (IL-1 alpha) production in keratinocytes was measured by enzyme-linked immunosorbent assay (ELISA) because of its pronounced proinflammatory effect. In keratinocytes, GDF-5 stimulated cell proliferation to a minor extent. The drug already proved to be effective at very low concentrations (0.1 ng/ml). Growth stimulatory effects with EGF have been observed only in keratinocyte basal medium (KBM), but not in keratinocyte growth medium (KGM). TGF-beta 1 markedly inhibited the proliferation of keratinocytes at concentrations > 1 ng/ml. Calcipotriol and desoximetasone also showed a dose-dependent cell growth inhibition in epidermal cell cultures. IL-1 alpha synthesis was greatly suppressed by calcipotriol 10(-8)-10(-6) M. EGF at 10 ng/ml, in contrast, strongly stimulated IL-1 alpha production. Neither GDF-5 nor TGF-beta 1 had a significant effect on IL-1 alpha production in keratinocyte monolayer cultures. In fibroblasts, GDF-5 induced very weak antiproliferative effects. Calcipotriol and desoximetasone also inhibited cell growth in fibroblast cultures whereas proliferation and DNA synthesis were strongly stimulated by 1 ng/ml EGF. There was, however, a contradiction between TGF-beta 1 results on fibroblasts. Whereas TGF-beta 1 increased proliferation in cell number determination and in the thymidine incorporation assay, MTT assays showed slight antiproliferative effects. Due to these controversial results, in addition cell cycle analysis was employed. TGF-beta 1 led to an increased S phase, which indicates a stimulation of cell division. The different results obtained with the MTT test suggest that TGF-beta 1 may stimulate cell division of fibroblasts not only by increasing the S phase, but also by shortening the G1 phase of the cell cycle.     

Induction of osteoblast differentiation in human adipose derived stem cells by lanthanum ions

Adipose derived stem cells represent a readily available source of adult stem cells for various biomedical applications. In this study, the proliferation and osteogenic differentiation potential of lanthanum nitrate（La3＋） on human adipose derived mesenchymal stem cells（hADSCs） were investigated for the first time and compared with that of dexamethasone（Dex）. Our results provided evidence that La3＋ at 50 μmol/L concentration promoted proliferation of hADSCs upto 2.4 fold when treated for 21 d in DMEM medium. Treatment of hADSCs with La3＋ containing osteogenic induction medium（α-MEM with ascorbic acid and β-glycerophosphate） for 7 d resulted in higher calcium deposition than that in the presence of Dex（0.1 μmol/L） as shown by Alizarin red S and von Kossa staining. Scanning electron micrographs also showed more extracellular matrix mineralization in the presence of La3＋. After 7 d of treatment with La3＋（10 μmol/L） the expression of RunX2, osteopontin（OP） and osteocalcin（OC） increased 3.4, 5.5 and 2.7 fold respectively. Our results provided evidence that in the presence of La3＋ osteogenic differentiation occurred earlier than that in the presence of Dex.     

Vacuum ultraviolet excited photoluminescence properties of Gd2O2CO3:Eu3+ phosphor

The Gd2O2CO3:Eu3 with type-II structure phosphor was successfully synthesized via flux method at 400℃ and their photoluminescence properties in vacuum ultraviolet (VUV) region were examined. The broad and strong excitation bands in the range of 153-205 nm owing to the CO32- host absorption and charge transfer (CT) of Gd3 -O2- were observed for Gd2O2CO3:Eu3 . Under 172 nm excitation, Gd2O2CO3:Eu3 exhibited strong red emission with good color purity, indicating Eu3 ions located at low symmetry sites and the chromaticity coordination of luminescence for Gd2O2CO3:Eu3 was (x=0.652, y=0.345). The photoluminescence quenching concentration of Eu3 excited by 172 nm for Gd2O2CO3:Eu3 was about 5%. Gd2O2CO3:Eu3 would be a potential VUV-excited red phosphor applied in mercury-free fluorescent lamps.     

Eu3+激活的Li2Gd4（MoO4）7钼酸盐红色荧光体及其发光性质

由高温固相反应首次合成Li2(Gd1-xEux)4(MoO4)7(0相似文献   

The involvement of protein kinase C in proliferation and differentiation of human keratinocytes--an investigation using inhibitors of protein kinase C

Protein kinase C, the major cellular receptor for tumour-promoting phorbol esters, has been suggested as playing a key role in the regulation of proliferation and differentiation of epidermal cells. In the present study, we investigated the effects of various well-characterized inhibitors of protein kinase C on proliferation and differentiation of SV 40-transformed and normal human keratinocytes. The drugs were found to inhibit cell proliferation in a dose-dependent manner, displaying similar effects in both cell types and reflecting their potencies in inhibiting purified protein kinase C. In contrast, keratinocyte differentiation induced by treatment with a calcium ionophore or spontaneously, i.e. by exposure of cells grown in the presence of low calcium concentration (0.06 mM) to normal calcium concentration (1.6 mM), was not inhibited by the compounds tested. The potent protein kinase C inhibitor, staurosporine, was found even to enhance cell differentiation. Therefore, the present study provides evidence that the classical protein kinase C pathway plays a critical role in the regulation of keratinocyte proliferation rather than in calcium-induced differentiation.     

Gd2-xEuxWO6红色荧光粉的溶胶-凝胶合成及其荧光性能分析

利用溶胶-凝胶法制备系列Gd2-xEuxWO6红色荧光粉,XRD测试表明Gd2-xEuxWO6具有单斜晶系结构;在298 nm或395 nm激发下,荧光粉主要发射出对应于Eu3+5的D0→7 F2能级跃迁的612 nm红光;当Gd2-xEuxWO6中Eu3+的掺杂量为50％时,荧光粉612nm红光强度最强;在合成过程中适当添加聚乙二醇(PEG)和柠檬酸能改善荧光粉的红光发射强度.     

Enkephalins modulate differentiation of normal human keratinocytes in vitro

Opioid peptides are a group of neuropeptides which include enkephalins, endorphins and dynorphins. In addition to their central and peripheral antinociceptive function, opioids can modulate immune activity and cell proliferation. Previously, we have shown that enkephalins are present in macrophages infiltrating the dermal papillae in involved psoriatic skin and that the amount of enkephalin is significantly increased in involved psoriatic skin. Because enkephalins were detected close to the epidermis, we examined the effects of opioid peptides on the differentiation (transglutaminase type 1 activity and cytokeratin 10 expression) and proliferation (MTT assay) of cultured human keratinocytes. Enkephalins (methionine-enkephalin, leucine-enkephalin and the synthetic DADL) inhibited cell differentiation dose-dependently, while beta-endorphin had no effect. The opioid receptor antagonist naltrexone completely antagonized the inhibitory effect of methionine-enkephalin and leucine-enkephalin, but not that of DADL. Furthermore, methionine-enkephalin had a slight inhibitory effect on the proliferation of keratinocytes. Enkephalin was detected in unstimulated keratinocyte cultures, and naltrexone alone stimulated keratinocyte differentiation. These results indicate that enkephalins may play a role in the differentiation of epidermal keratinocytes. It remains to be determined whether the enkephalin detected in psoriatic skin are sufficient to affect epidermal differentiation in vivo.     

Pharmacological analysis of diisopropyl fluorophosphate: effects on core temperature, heart rate, and motor activity in the unrestrained rat

Sex steroid-binding activities have been identified by several authors in normal and pathological thyroids and the expression of the canonic androgen receptor (AR) has recently been demonstrated in human thyroid follicular cells. In order to assess what influence, if any, androgen exposure has on thyroid cell growth, the effect of dihydrotestosterone (DHT) on [3H]thymidine (thy) incorporation and cell proliferation was investigated in thyroid follicular cells in vitro. In a primary culture of goitrous cells, DHT induced a significant reduction of [3H]thy incorporation at concentrations ranging from 10(-12) to 10(-8) M, with a more pronounced effect at 10(-9) M. At this concentration, the inhibitory effect was evident after both 24 and 48 h of treatment and in various types of primary thyroid cell cultures. In goitrous cells, the DHT-induced decrease of [3H]thy was associated with a reduction of expression of the proliferation-associated nuclear Ki-67 antigen, a protein commonly used to assess cell growth fraction. In TPC cells, an AR-positive thyroid papillary carcinoma cell line, DHT at concentrations between 10(-12) and 10(-8) M significantly decreased the growth rate. DHT (10(-9) M) produced an approximately 50-60% inhibition of cell proliferation and the antiandrogen cyproterone acetate was capable of reversing such effects. The DHT-induced reduction of TPC cell proliferation was associated with a significant reduction of c-myc RNA levels. Thyroperoxidase mRNA levels and thyroglobulin production were not reduced by androgen in primary cultures of goitrous cells. In conclusion, our results indicated that androgens may have a role in this gland by reducing the proliferation, but not the function, of follicular cells.     

Comparative effects of the metabolic inhibitors 2,4-dinitrophenol and iodoacetate on mouse neuroblastoma cells in vitro

The toxic effects of two metabolic inhibitors, dinitrophenol and iodoacetic acid, were compared. Mouse neuroblastoma cell cultures (Neuro-2a) were exposed to different concentrations of the toxic compounds for 24, 48 and 72 h to study basal toxicity effects (cell proliferation by quantification of total protein content (PR) and relative neutral red uptake (RNRU) by lysosomes). The following biochemical indicators assessed in the in vitro test system were: cytosolic phosphofructokinase (PFK) and enolase (ENL) activities in glycolysis; mitochondrial succinate dehydrogenase (SDH) activity in the citric acid cycle; lysosomal beta-galactosidase (GAL) activity; and neuronal acetylcholinesterase (AChE) activity. The effects of the two metabolic inhibitors on the various indicators differed. Iodoacetic acid was found to be far more toxic than dinitrophenol to neuroblastoma cell proliferation at 24 h exposure. Though 2,4-dinitrophenol and iodoacetic acid both inhibited cell proliferation of the neuroblastoma cells, their effects on the other endpoints were opposite. Dinitrophenol was a general activator of the metabolism, particularly affecting lysosomal function. Iodoacetic acid did not significantly alter general metabolism, but considerably modified lysosomal function and AChE activity. The modification of lysosomal function of Neuro-2a cells by the two compounds was quite different: dinitrophenol increased RNRU and GAL activity, and iodoacetic acid decreased both parameters.     

Time- and concentration-dependence of the growth-promoting activity of insulin and histamine in Tetrahymena. Application of the MTT-method for the determination of cell proliferation in a protozoan model

The unicellular ciliate Tetrahymena pyriformis was treated with different concentrations of insulin or histamine and at different time points the cell density was measured, using a tetrazolium-based semiautomated colorimetric assay (MTT). The assay was suitable to determine the rate of cell proliferation of Tetrahymena. Insulin in each concentration significantly elevated the cell count up to 3 h. After that, it was neutral or its effect was insignificant. Histamine at 10(-5) M concentration diminished cell count at 3, 5, 7 and 24 h. At 10(-6) M concentration there was no difference and at 10(-7) M concentration it enhanced cell division up to 5 h, after that there being no difference. The two hormones have cell division promoting activity for cells of higher animals and the experiments demonstrate this effect already at a unicellular level.     

Erythroid potentiating activity of tissue inhibitor of metalloproteinases on the differentiation of erythropoietin-responsive mouse erythroleukemia cell line, ELM-I-1-3, is closely related to its cell growth potentiating activity

The erythroid-potentiating activity (EPA) of the tissue inhibitor of metalloproteinase-1 (TIMP-1) was re-examined using ELM-I-1-3, a mouse erythroleukemia cell line, which responded well to erythropoietin. Depletion of pre-existing TIMP-1 from fetal calf serum in culture medium using monoclonal antibody suppressed erythropoietin-induced differentiation as measured by the induction of hemoglobin, commitment assay and globin mRNAs. The removal of TIMP-1 also suppressed the proliferation of ELM-I-1-3 as measured by cell number and de novo DNA synthesis. These changes were reversed by the addition of purified TIMP-1 to the culture medium. Anti-TIMP-1 antibody also blocked both hexamethylene bisacetamide (HMBA)-induced erythroid differentiation and the proliferation of both ELM-I-1-3 and Friend erythroleukemia cells. Considering previous reports analyzing the chemical induction of Friend mouse erythroleukemia cell differentiation, our results suggest that erythropoietin- or HMBA-induced erythroid differentiation might also be coupled with cell proliferation. Our 3H thymidine-uptake experiment shows that TIMP-1 removal was also effective in the inhibition of cell growth of various other cell lines in addition to erythroleukemia cell lines. These results suggest that EPA action of TIMP-1 on erythroid leukemia cell lines is closely related to its activity to promote the cell growth of various cell lines and cells including erythroleukemia cell lines.     

Sequence-related behaviour of transmembrane domains from class I receptor tyrosine kinases

The purpose of this study was to investigate the effects of 316L stainless steel (SS) corrosion products on the in vitro biomineralization process, because tissue necrosis, bone loss, impaired bone mineralization, and loosening of orthopedic implants are associated with ions and debris resulting from biodegradation. Rat bone marrow cells were cultured in experimental conditions that favored the proliferation and differentiation of osteoblastic cells and were exposed to SS corrosion products obtained by electrochemical means for periods ranging from 1 to 21 days. Quantification of total and ionized Ca and P, as well as Fe, Cr, and Ni, ions in the culture media of control and metal added cultures during the incubation period was performed to study the influence of corrosion products on the Ca and P consumption that occurs during the mineralization process. Control cultures and metal effects on cultures were evaluated concerning DNA content, enzymatic reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and alkaline phosphatase (ALP) activity. Histochemical detection of ALP, Ca, and phosphate deposition, and examination of the cultures by scanning and transmission electron microscopy (SEM and TEM) were also performed. The presence of SS corrosion products resulted in impairment of the normal behavior of rat bone marrow cultures. Levels of Cr and Ni in the medium of cultures exposed to 316L SS corrosion products decreased throughout the incubation period, suggesting a regular deposition of these species; these results were supported by TEM observation of the cultures. Cultures exposed to the corrosion products presented lower DNA content, MTT reduction, and ALP activity and failed to form mineralized areas. These cultures showed negative staining on histochemical reactions for the identification of calcium and phosphate deposition and SEM and TEM examination did not show mineral globular structures or mineralization foci, respectively, which is characteristic of cultures grown in control conditions. These results suggest that metal ions associated with 316L SS are toxic to osteogenic cells, affecting their proliferation and differentiation.