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Objective::To study the effect of Hei Xiaoyaosan on the expression of calcium calmodulin-dependent protein kinase Ⅱ alpha(CaMKⅡα) and its phosphorylation in hippocampus and cortex of mice with Alzheimer's disease. Method::After weighing, 30 APP/PSI transgenic male mice were divided into model group, donepezil hydrochloride group and Hei Xiaoyaosan group according to random principle and 10 in each group.At the same age, wild-type C57BL/6 10 mice of the same species were treated as blank group. Donepezil hydrochloride group (6 g·kg-1) and Hei Xiaoyaosan group (3.25 mg·kg-1) were administered for 90 days, then the behavior of all the mice were detected by Morris water maze, the expression of CaMKⅡα, p-CaMKⅡα proteins in hippocampus and cortex by immunohistochemical technique and Western blot. Result::After intervention 3 months, compared with blank group, the average escaping latency periods prolonged significantly and the number of cross-platform and effective areas were decreased distinctly in model group mice(P<0.01), CaMKⅡα protein relative expression decreased significantly(P<0.01), p-CaMKⅡα protein relative expression increased significantly(P<0.01). Compared with the model group, the escape latency of donepezil hydrochloride and Hei Xiaoyaosan group were significantly shortened, and the number of crossing platforms and effective areas was significantly increased (P<0.05, P<0.01), the expression of CaMKⅡα protein in the hippocampus and cortex of drug groups was significantly increased (P<0.01), p-CaMKⅡα protein in the hippocampus and cortex of drug groups was significantly decreased (P<0.05, P<0.01). Conclusion::Hei Xiaoyaosan can improve the learning and memory ability of AD mice by regulating the expression of CaMKⅡα and its phosphorylation, which are key proteins involved in the mechanism of cell memory formation in different brain regions of AD mice.
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Objective The aim of this study was to investigate the effect of Ca2+ /calmodulin - dependent kinase II (CaMKII)γ RNA interference on the expression of nuclear factor of activated T-cells cytoplasmic 1(NFATc1),tyrosine kinase(c-Src)and tartrate resistant acid phosphatase(TRAP)genes,and its role and molecular mechanism in osteoclast differentiation. Methods The CaMKII γ RNA interference vector was constructed by lentivirus and transfected into RAW264. 7 cells. The experiment was di-vided into three groups:A,B and C,which were the control group,negative vector group and interference vector group. After transfec-tion for 12 hours,osteoclasts induced by 50 ng/mL RANKL and the cells were harvested after induction for 5 days. Real-time quanti-tative PCR,Western blot and immunofluorescence were used to detect the expression of NFATc1,TRAP and c-Src genes in three groups. Results The mRNA levels of NFATc1,TRAP and c-Src in the group C decreased by 49. 86% ,43. 65% and 53. 57% ,re-spectively(P<0. 001),and the protein levels decreased by 54. 22% ,46. 75% and 45. 86% ,respectively(P<0. 001). There was no significant difference between the A and the B groups(P>0. 05). The fluorescence intensity of the above genes in the group C was significantly weaker than that in the A and B groups,and the formation of osteoclasts was significantly less than that in the A and B groups. Conclusion CaMKIIγ RNA interference significantly inhibited the expression of NFATc1,TRAP and c-Src genes,sugges-ting that CaMKIIγ plays a key regulatory role in osteoclast differentiation.
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Objective To investigate the effects of calmodulin-dependent kinase IIγ (GaMKIIγ) RNA interference on osteoclast differentiation and bone resorption. Methods Three CaMKIIγ recomninant RNA interference vectors were constructed using lentivirus. Negative vector was used to transfect RAW264.7 cells and the multiplicity of infection (MOI) with the optimal transfection efficiency was determined. Recombinant vectors were also used to transfect cells to determine the one with the best interference effect for following experiments.Then, the cells were divided into control group, negative vector group and interference vector group. Five days after virus transfection, osteoclastogenesis and bone resorption function were determined by TRAP staining and dentin resorption lacunae detection. Results Three CaMKIIγ recombinant interference vectors were constructed, and the optimal MOI was 30, under which transfection efficiency was about 81％. The #3 recombinant vector showed the best interference effect and the interference efficiency was up to 78.16％ at mRNA level and 67.02％ at protein level. When compared with control group, the number of multi-nucleated osteoclasts, the number and area of dentin resorption lacunaes in interference vector group decreased 59.99％、54.19％ and 57.94％ respectively (P < 0.01). No significant difference were observed between negative vector group and control group (P> 0.05).Conclusion CaMKIIγ RNA interference significantly inhibits osteoclastogenesis and bone resorption.
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Objective To investigate the function of cAMP response element binding protein (CREB) and extracellular signal-regulated kinase (ERK1/2) in osteoclast differentiation mediated by Ca2+/calmodulin-dependent kinase Ⅱ (CaMK Ⅱ)δ,and elucidate the molecular mechanism thereof.Methods CaMK Ⅱδ RNA interference lentivirus vector was constructed and mouse RAW264.7 cells were transfected with the virus to determine the interference efficiency.After virus transfection,RAW264.7 cells were treated with 50ng/ml receptor activator of nuclear factor κB ligand (RANKL) and the phosphorylation levels of CREB and ERK1/2 were detected at different time points.The cells were also treated with PD98059,an ERK1/2 inhibitor,to determine the effect of ERK1/2 signal blocking on the expression of nuclear factor activated T-cells cytoplasmic 1 (NFATc1) and osteoclast differentiation.Results Interference efficiency of recombinant CaMK Ⅱδ virus vector was 77.2％ at mRNA level and 70.2％ at protein level.CaMK Ⅱδ RNA interference significantly suppressed phosphorylation of CREB and ERK1/2,and the levels ofp-CREB and p-ERK1/2 were down-regulated by 21％-55％ and 55％-64％,respectively.ERK1/2 inhibitor significantly down-regulated the protein expression of NFATc1,and the number of osteoclast,the number and size of bone resorption lacunae decreased by 39.3％,50.0％ and 52.3％,respectively.Conclusion CaMK Ⅱδ RNA interference may significantly suppress the phosphorylation of CREB and ERK1/2,and CREB and ERK1/2 have mediated the CaMK Ⅱδ-induced osteoclast differentiation.
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Objective:To study the expression profiles and the role of Ca2+/calmodulin-dependent protein kinase Ⅱγ (CaMKⅡγ) during osteoclast differentiation.Methods:Mouse RAW264.7 cells were induced for osteoclastogenesis with 50 ng/mL receptor activator of nuclear factor-κB ligand (RANKL) and the cells were harvested at 0,1,3 and 5 days after induction.Tartrate-resistant acid phosphotase staining was performed to verify osteoclasts formation.RT-PCR,Western blot and immunofluorescent cytochemistry were used to detect the CaMKⅡγ gene expression during osteoclastogenesis.Results:The osteodasts were formed at day 3 under RANKL induction and more osteoclasts were observed at day 5.At day 0,1,3 and 5,the relative level of CaMKⅡγ mRNA were (1.067±0.179),(1.840±0.070),(9.493±0.453) and (30.767±0.573),respectively,and the relative protein level were (0.454±0.065),(0.613±0.021),(0.858±0.019) and (0.980±0.023),respectively.CaMKⅡγ expression was increased in a time-dependent manner except relative protein level at day 1 (P＜0.01),which showed no significant difference at day 0 (P＞0.05).Immunofluorescence assay showed that CaMKⅡγ protein was also increased with differentiation of osteoclasts.Conclusion:The CaMKⅡγ expression was increased in a time-depended manner during osteoclast differentiation and it might play a vital role during osteoclastogenesis.
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Objective To study the effect of zoledronate (ZOL) on Ca2+/calmodulin-dependent kinase Ⅱ δ (CaMK Ⅱ δ) and down-stream gene expressions during osteoclast differentiation.Methods Mouse osteoclast precursors RAW264.7 cells were divided into the control group and ZOL group.The cells in both groups were induced with 50μg/L receptor activator of nuclear factor kappa B ligand (RANKL) and were harvested on 5 d,while the cells in ZOL group were also simultaneously treated with 1 × 10-6 mol/L ZOL for 2 d.Five days later,the cells were harvested and examined osteoclastogenesis,as well as gene expressions of CaMK Ⅱ δ,nuclear factor of activated T-cells cytoplasmic 1 (NFATc1),tartrate-resistant acid phosphatase (TRAP) and cell-sarcoma receptor coactivator (c-Src).Results The number of TRAP positive multinuclear osteoclasts,number and size of dentin absorption lacunae and area in the ZOL group were (20.0±3.2),(18.0±4.2) and (6 335.3± 1 043.2)μm2 respectively,which were significantly lower than (36.0 ± 8.4),(37.2 ± 5.0) and (11 636.2 ± 3 661.1) μm2 in the control group and decreased by 44.4 ％,51.6 ％ and 45.6 ％ respectively (P＜0.01).ZOL also significantly inhibited the gene expressions of CaMK Ⅱ δ,NFATc1,TRAP and c-Src,and the mRNA levels of these genes were decreased by 44.1％,49.0％,53.8％ and 49.6％ respectively,the protein level were decreased by 43.5 ％,32.2 ％,45.5 ％ and 48.0 ％ respectively.The immunofluorescent cytochemistry detection results showed the fluorescence intensity of CaMK Ⅱ δ,NFATc1,TRAP and c-Srcin in the ZOL group was significantly weakened when compared with the control group.Conclusion ZOL could significantly inhibit the osteoclast formation and bone absorption function,and down-regulates gene expressions of CaMK Ⅱ δ,NFATc1,TRAP and c-Src in osteoclast differentiation.
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Ca2+ pumps are important players in smooth muscle contraction. Nevertheless, little information is available about these pumps in the vas deferens. We have determined which subtype of sarco(endo)plasmic reticulum Ca2+-ATPase isoform (SERCA) is expressed in rat vas deferens (RVD) and its modulation by calmodulin (CaM)-dependent mechanisms. The thapsigargin-sensitive Ca2+-ATPase from a membrane fraction containing the highest SERCA levels in the RVD homogenate has the same molecular mass (∼115 kDa) as that of SERCA2 from the rat cerebellum. It has a very high affinity for Ca2+ (Ca0.5 = 780 nM) and a low sensitivity to vanadate (IC50 = 41 µM). These facts indicate that SERCA2 is present in the RVD. Immunoblotting for CaM and Ca2+/calmodulin-dependent protein kinase II (CaMKII) showed the expression of these two regulatory proteins. Ca2+ and CaM increased serine-phosphorylated residues of the 115-kDa protein, indicating the involvement of CaMKII in the regulatory phosphorylation of SERCA2. Phosphorylation is accompanied by an 8-fold increase of thapsigargin-sensitive Ca2+ accumulation in the lumen of vesicles derived from these membranes. These data establish that SERCA2 in the RVD is modulated by Ca2+ and CaM, possibly via CaMKII, in a process that results in stimulation of Ca2+ pumping activity.
Subject(s)
Animals , Male , Rats , Calcium-Binding Proteins/metabolism , Calcium-Transporting ATPases/metabolism , Calmodulin/metabolism , Protein Serine-Threonine Kinases/metabolism , Vas Deferens/metabolism , Muscle Contraction , Phosphorylation , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolismABSTRACT
We investigated whether Ca2+/calmodulin-dependent kinase II (CaMKII) and calcineurin (CaN) are involved in myocardial hypertrophy induced by tumor necrosis factor α (TNF-α). The cardiomyocytes of neonatal Wistar rats (1-2 days old) were cultured and stimulated by TNF-α (100 μg/L), and Ca2+ signal transduction was blocked by several antagonists, including BAPTA (4 µM), KN-93 (0.2 µM) and cyclosporin A (CsA, 0.2 µM). Protein content, protein synthesis, cardiomyocyte volumes, [Ca2+]i transients, CaMKIIδB and CaN were evaluated by the Lowry method, [³H]-leucine incorporation, a computerized image analysis system, a Till imaging system, and Western blot analysis, respectively. TNF-α induced a significant increase in protein content in a dose-dependent manner from 10 µg/L (53.56 µg protein/well) to 100 μg/L (72.18 µg protein/well), and in a time-dependent manner from 12 h (37.42 µg protein/well) to 72 h (42.81 µg protein/well). TNF-α (100 μg/L) significantly increased the amplitude of spontaneous [Ca2+]i transients, the total protein content, cell size, and [³H]-leucine incorporation in cultured cardiomyocytes, which was abolished by 4 µM BAPTA, an intracellular Ca2+ chelator. The increases in protein content, cell size and [³H]-leucine incorporation were abolished by 0.2 µM KN-93 or 0.2 µM CsA. TNF-α increased the expression of CaMKIIδB by 35.21% and that of CaN by 22.22% compared to control. These effects were abolished by 4 µM BAPTA, which itself had no effect. These results suggest that TNF-α induces increases in [Ca2+]i, CaMKIIδB and CaN and promotes cardiac hypertrophy. Therefore, we hypothesize that the Ca2+/CaMKII- and CaN-dependent signaling pathways are involved in myocardial hypertrophy induced by TNF-α.
Subject(s)
Animals , Rats , Calcineurin/metabolism , /metabolism , Cardiomegaly/metabolism , Myocytes, Cardiac/metabolism , Tumor Necrosis Factor-alpha/pharmacology , Animals, Newborn , Cells, Cultured , Cardiomegaly/chemically induced , Cardiomegaly/pathology , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/pathology , Rats, Wistar , Signal TransductionABSTRACT
Aim To investigate whether Ca~(2+)/calmodulin-dependent kinase Ⅱ(CaMKⅡ)contribute to tumor necrosis factor α(TNF-α)-induced cardiomyocyte hypertrophy.Methods The protein content was assayed with Lowry's method.The cardiomyocytes volumes were measured by computer photograph analysis system.The protein synthesis was assayed with[~3H]-lencine incorporation method.[Ca~(2+)]_i transient was measured by Till image system by cell-loading Fura-2/AM.The expression of CaMKⅡδ_B was determined by Western blot.Results ① TNF-α significantly induced the increase of protein content, [~3H]-leucine incorporation and cell size;These responses were significantly suppressed by KN93, a selective CaMKⅡ inhibitor.② TNF-α increased the amplitude of the spontaneous Ca~(2+) transients in cultured ventricular myocytes from the neonatal rat;CaMKⅡ inhibitor KN93 can suppress the elevation induced by TNF-α.③ TNF-α significantly increased the expression of CaMKⅡδ_B.Concluslon CaMKⅡ signal pathway are involved in TNF-α-induced cardiomyocyte hypertrophy in rats.
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Aim To investigate whether Ca2+/calmodulin-dependent kinase Ⅱ(CaMKⅡ)contribute to tumor necrosis factor ?(TNF-?)-induced cardiomyocyte hypertrophy.Methods The protein content was assayed with Lowry's method.The cardiomyocytes volumes were measured by computer photograph analysis system.The protein synthesis was assayed with[3H]-lencine incorporation method.[Ca2+]i transient was measured by Till image system by cell-loading Fura-2/AM.The expression of CaMKⅡ?B was determined by Western blot.Results ① TNF-? significantly induced the increase of protein content,[3H]-leucine incorporation and cell size;These responses were significantly suppressed by KN93,a selective CaMKⅡ inhibitor.② TNF-? increased the amplitude of the spontaneous Ca2+ transients in cultured ventricular myocytes from the neonatal rat;CaMKⅡ inhibitor KN93 can suppress the elevation induced by TNF-?.③ TNF-? significantly increased the expression of CaMKⅡ?B.Concluslon CaMKⅡ signal pathway are involved in TNF-?-induced cardiomyocyte hypertrophy in rats.