Evolution of mammographic image quality in the state of Rio de Janeiro / A evolução da qualidade da imagem em mamografia no Estado do Rio de Janeiro

Objective: To evaluate the evolution of mammographic image quality in the state of Rio de Janeiro on the basis of parameters measured and analyzed during health surveillance inspections in the period from 2006 to 2011. Materials and Methods: Descriptive study analyzing parameters connected with imaging quality of 52 mammography apparatuses inspected at least twice with a one-year interval. Results: Amongst the 16 analyzed parameters, 7 presented more than 70% of conformity, namely: compression paddle pressure intensity (85.1%), films development (72.7%), film response (72.7%), low contrast fine detail (92.2%), tumor mass visualization (76.5%), absence of image artifacts (94.1%), mammography-specific developers availability (88.2%). On the other hand, relevant parameters were below 50% conformity, namely: monthly image quality control testing (28.8%) and high contrast details with respect to microcalcifications visualization (47.1%). Conclusion: The analysis revealed critical situations in terms of compliance with the health surveillance standards. Priority should be given to those mammography apparatuses that remained non-compliant at the second inspection performed within the one-year interval. .

Objetivo: Avaliar a evolução da qualidade da imagem de mamógrafos localizados no Estado do Rio de Janeiro, de 2006 a 2011, com base em parâmetros medidos e observados durante inspeções sanitárias. Materiais e Métodos: Estudo descritivo sobre a evolução de parâmetros que condicionam a qualidade da imagem focalizou 52 mamógrafos, inspecionados no mínimo duas vezes, com intervalo de um ano. Resultados: Dos 16 parâmetros avaliados, 7 apresentaram mais de 70% de conformidade: força do dispositivo de compressão (85,1%), processamento dos filmes (72,7%), resposta do filme do serviço (72,7%), detalhes lineares de baixo contraste (92,2%), visualização de massas tumorais (76,5%), ausência de artefatos de imagem (94,1%), existência de processadoras específicas para mamografia (88,2%). Importantes parâmetros apresentaram-se abaixo de 50% de conformidade: realização de testes mensais da qualidade de imagem pelo estabelecimento (28,8%) e detalhes de alto contraste, que dizem respeito à visualização de microcalcificações (47,1%). Conclusão: A análise revelou situações críticas da atuação da vigilância sanitária, cuja prioridade deveria ser dirigida aos estacionários, ou seja, os mamógrafos que permaneceram na situação de não conformidade nas inspeções realizadas com intervalo de um ano. .

Protective effects of kaempferol against cardiac sinus node dysfunction via CaMKII deoxidization / 대한해부학회지

Kaempferol exerts cardioprotective actions through incompletely understood mechanisms. This study investigated the molecular mechanisms underlying the cardioprotective effects of kaempferol in sinus node dysfunction (SND) heart. Here, we demonstrate that angiotensin II (Ang II) infusion causes SND through oxidized calmodulin kinase II (CaMKII). In contrast to this, kaempferol protects sinus node against Ang II-induced SND. Ang II evoked apoptosis with caspase-3 activation in sinus nodal cells. However, kaempferol lowered the CaMKII oxidization and the sinus nodal cell death. To block the CaMKII oxidization, gene of p47phox, a cytosolic subunit of NADPH oxidase, was deleted using Cas9 KO plasmid. In the absence of p47phox, sinus nodal cells were highly resistance to Ang II-induced apoptosis, suggesting that oxidized-CaMKII contributed to sinus nodal cell death. In Langendorff heart from Ang II infused mice, kaempferol preserved normal impulse formation at right atrium. These data suggested that kaempferol protects sinus node via inhibition of CaMKII oxidization and may be useful for preventing SND in high risk patients.

Maltrato institucional hacia el adulto mayor: percepciones del prestador de servicios de salud y de los ancianos / Institutional abuse toward the elderly: Perceptions of health care providers and older adults

Objetivo. Analizar la percepción que el prestador de servicios de salud y el adulto mayor (AM) tienen sobre el maltrato al AM en los servicios públicos de salud, en ciudades seleccionadas de México. Material y métodos. De 2009 a 2012 se realizó un estudio con diseño cualitativo y estrategia de triangulación de fuentes de datos; se efectuaron entrevistas semiestructuradas a 13 prestadores y a 12 ancianos para recuperar su experiencia en el tema. El análisis utilizó procedimientos de la Teoría Fundamentada. Resultados. El maltrato contra el AM es una práctica naturalizada por el personal y por el anciano, la cual se manifiesta de formas diversas. Conclusiones. La institucionalización, profesionalización histórica y falta de conciencia sobre las necesidades de los AM demandan cambios de planeación, organización y supervisión del Sistema de Salud. El personal requiere intervenciones de formación, capacitación y cambio de actitudes/comportamiento, para otorgar atención integral, digna, humana y de respeto a los Derechos Humanos de los AM.

Objective. To analyze the health care providers (HCP) and elderly patients' perceptions about abuse of the elderly by health personnel of public health services, in selected cities in Mexico. Materials and methods. A qualitative study and a strategy of data triangulation were performed during 2009 and 2012; 13 HCPs and 12 elders were interviewed, in order to obtain their experience regarding elder abuse. Grounded Theory proceedings were used for the analysis. Results. Elder abuse is a naturalized practice, from HCP and elderly people's point of view; these perceptions are showed in different ways. Conclusion. Institutionalization, historical professionalization and lack of consciousness about needs of the elderly (sociocultural and economic), require changes in planning, organization and monitoring process in the Health System; training and educational interventions on staff and exchange attitudes and behavior are necessary in order to offer a health care that is comprehensive, decent, human and with respect for the human rights.

MICrocephaly, disproportionate pontine and cerebellar hypoplasia syndrome: A clinico-radiologic phenotype linked to calcium/calmodulin-dependent serine protein kinase gene mutation.

MICrocephaly, disproportionate pontine and cerebellar hypoplasia (MICPCH) syndrome, a rare X-linked disorder, generally seen in girls, is characterized by neurodevelopmental delay, microcephaly, and disproportionate pontine and cerebellar hypoplasia. It is caused by inactivating calcium/calmodulin-dependent serine protein kinase (CASK) gene mutations. We report a 2-year-old girl with severe neurodevelopmental delay, microcephaly, minimal pontine hypoplasia, cerebellar hypoplasia, and normal looking corpus callosum, with whom the conventional cytogenetic studies turned out to be normal, and an array-comparative genomic hybridization (a-CGH) analysis showed CASK gene duplication at Xp11.4. Our case highlights the importance of using clinico-radiologic phenotype to guide genetic investigation and it also confirms the role of a-CGH analysis in establishing the genetic diagnosis of MICPCH syndrome, when conventional cytogenetic studies are inconclusive.

Death-associated protein kinase promoter (DAPK) hypermethylation in uterine cervical cancer and intraepithelial neoplasia in Uyghur nationality women / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the methylation levels of death-associated protein kinase (DAPK) in Uyghur female patients with different cervical lesions in Xinjiang, and to discuss the relationship of the expression and significance of DAPK in normal cervix, chronic cervicitis, cervical intraepithelial neoplasia (CINI, CIN II/III) and invasive cervical squamous cell carcinoma.</p><p><b>METHODS</b>30 cases of normal cervix and chronic cervicitis, 30 cases of CINI, 30 cases of CINII/III and 30 cases of cervical squamous cell carcinoma were tested by methylation specific PCR (MSP). Expressions of DAPK in 30 cases of normal cervix and chronic cervicitis, 30 cases of CINI, 30 cases of CINII/III and 30 cases of cervical squamous cell carcinoma were assayed using immunohistochemical SP staining.</p><p><b>RESULTS</b>The methylation rate of DAPK gene in normal cervix and chronic cervicitis was 3.33%, 10% in cervical intraepithelial neoplasia CINI, 36.7% in CINII/III, and 63.3% in invasive cervical squamous cell carcinoma. The methylation rate of DAPK in the SCC group was significantly higher than that in the other groups (P < 0.05). Aberrant promoter methylation of the DAPK gene was positively correlated with the degree of cervical lesions. The positive rate of DAPK protein in normal cervix and chronic cervicitis was 93.3%, 83.3% in cervical intraepithelial neoplasia CINI, 60.0% in CINII/III, and 33.3% in invasive cervical squamous cell carcinoma. The expression of DAPK in the SCC group was significantly lower than that in the other groups (P < 0.05). The positive rate of DAPK protein was negatively correlated with the degree of cervical lesions (r(s) = -0.603, P < 0.001).</p><p><b>CONCLUSIONS</b>Methylation of DAPK is involved in the cervical carcinogenesis and DAPK gene promoter methylation occurs in the early development of cervical cancer in Uyghur women in Xinjiang. Detection of DAPK gene methylation may provide a basis for use in early detection of cervical cancer. DAPK protein expression is decreasing even disappears along with the progression of cervical lesions.</p>

Expression and clinical significance of DAPK1 and CD147 in esophageal squamous cell carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the amplification and expression status of DAPK1 and CD147 in esophageal squamous cell carcinoma (ESCC) and their relationship with the prognosis of ESCC.</p><p><b>METHODS</b>Immunohistochemical staining and RT-PCR were used to detect the expression and amplification of DAPK1 and CD147 in esophageal squamous carcinoma tissue and normal esophageal mucosa. Statistical analysis of the clinocopathological data was performed with SPSS 11.5 software package.</p><p><b>RESULTS</b>The positive rates of expression of DAPK1 protein and CD147 protein in the specimens of esophageal carcinoma were 31.3% and 58.5%, and in normal esophageal mucosa 57.5% and 25.0%, respectively, with a statistically significant difference (P < 0.001). The expressions of DAPK1 and CD147 were significant correlated with invasion depth, lymph node metastasis, TNM stage and the degree of cancer differentiation. (P < 0.05). The negative expression of DAPK1 and positive expression of CD147 indicated a poor prognosis. In 52 ESCC cases, the expression of DAPK1 in cancer tissues was 0.236 ± 0.049, and 0.395 ± 0.058 in normal esophageal mucosa, while that of CD147 mRNA expression was 0.942 ± 0.204 and 0.821 ± 171, respectively, statistically both with a very significant difference (P < 0.01). There was a higher expression level of DAPK1 mRNA in the cancer tissue in patients with no lymph node metastasis, well differentiation, and earlier pathological stage, and a higher expression level of CD147 mRNA in the cancer tissues in patients with lymph node metastasis, poor differentiation, and later pathological stage.</p><p><b>CONCLUSIONS</b>The expression of DAPK1 and CD147 proteins is closely correlated with the clinicopathological characteristics of ESCC. The genes DAPK1 and CD147 may participate in the metastasis and apoptosis of ESCC. The expression of DAPK1 and CD147 may be used as important prognostic predictors in ESCC.</p>

Platelet-rich plasma inhibits the apoptosis of highly adipogenic homogeneous preadipocytes in an in vitro culture system

Auto-transplantation of adipose tissue is commonly used for the treatment of tissue defects in plastic surgery. The survival of the transplanted adipose tissue is not always constant, and one of reasons is the accelerated apoptosis of the implanted preadipocytes. We have recently established highly homogeneous preadipocytes, named ccdPAs. The aim of the current study was to evaluate the regulation of the potency of platelet-rich plasma (PRP) on the apoptosis of ccdPAs in vitro. PRP stimulated the proliferation of the preadipocytes in a dose-dependent manner, and the stimulatory activity of 2% PRP was significantly higher than that of 2% FBS or 2% platelet-poor plasma (PPP). The presence of 2% PRP significantly inhibited serum starvation- or TNF-alpha/cycloheximide-induced apoptosis in comparison to 2% FBS or 2% PPP. DAPK1 and Bcl-2-interacting mediator of cell death (BIM) mRNAs were reduced in the preadipocytes cultured with 2% PRP in comparison to those cultured in 2% FBS. The gene expression levels were significantly higher in cells cultured without serum in comparison to cells cultured with 2% FBS, and the levels in the cells with 2% PRP were reduced to 5-10% of those in the cells without serum. These results indicated that ccdPAs exhibit anti-apoptotic activities, in addition to increased proliferation, when cultured in 2% PRP in comparison to the same concentration of FBS, and that this was accompanied with reduced levels of DAPK1 and BIM mRNA expression in in vitro culture. PRP may improve the outcome of transplantation of adipose tissue by enhancing the anti-apoptotic activities of the implanted preadipocytes.

Detection of methylation levels of multi-genes by real-time PCR in patients with myelodysplastic syndrome / 中华血液学杂志

<p><b>OBJECTIVE</b>To analyze the promoter methylation levels of p15, CDH1, DAPK and HICI genes of patients with myelodysplastic syndrome (MDS) and explore the relationship between the level of methylation and clinical features.</p><p><b>METHODS</b>DNA methylation levels of p15, CDH1, DAPK and HICI in peripheral blood (PB) or bone marrow (BM) samples from 52 MDS patients were detected by real-time quantitative PCR. The correlation of the methylation level with clinical features and hematological findings was analyzed. 38 de novo AML patients and 46 normal individuals served as controls.</p><p><b>RESULTS</b>The methylation levels of p15, CDH1, DAPK and HICI were 16.23 ± 21.69, 6.59 ± 9.39, 0.14 ± 0.11 and 7.81 ± 9.70 in BM, and 14.96 ± 20.16, 6.00 ± 9.26, 0.12 ± 0.14 and 6.74 ± 9.72 in PB, respectively from 18 MDS patients, and the difference between BM and PB was not statistically significant (P > 0.05). The methylation levels of p15 (14.70 ± 18.17) and CDH1 (6.61 ± 8.79) genes in high risk (RAEBI/II) MDS were significantly higher than in low risk (RCMD/RARS/5q-, p15: 1.99 ± 1.59, CDH1: 1.23 ± 1.14 and RCMD, p15: 3.02 ± 3.42, CDH1:1.53 ± 2.06) MDS or control (p15: 1.69 ± 1.82, CDH1: 1.01 ± 1.12) (P < 0.05). The methylation levels of DAPK gene had no difference among subtypes of MDS, and that of HIC1 gene only differed between RAEB I/II (9.16 ± 11.95) and control (2.49 ± 2.26) (P = 0.042). The difference of methylation levels of p15, CDH1, DAPK and HICI in BM was statistically significant among subtypes of MDS (P = 0.001, 0.003, 0.039, 0.023, respectively). And so did of p15 and DAPK in PB (P = 0.013, 0.006, respectively). The methylation level of p15 and CDH1 was significantly correlated with IPSS classification and blasts percentage in BM.</p><p><b>CONCLUSIONS</b>p15 and CDH1 genes are special hypermethylation genes in MDS. Methylation level of HIC1 gene showed an upward tendency from low risk to high risk MDS.</p>

Relationship between promoter methylation of p16, DAPK and RAR beta genes and the clinical data of non-small cell lung cancer / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the effects of promoter methylation of p16, death-associated protein kinase (DAPK) and retinoic acid receptor-beta (RAR beta) genes on clinical data in non-small cell lung cancers, and to study the effect of smoking on the risk of gene methylation.</p><p><b>METHODS</b>The promoter methylation of p16, DAPK and RAR beta genes in 200 primary non-small cell lung cancers and the corresponding nonmalignant lung tissues were determined by methylation-specific PCR.</p><p><b>RESULTS</b>Methylation in the tumor tissues was detected in 51.0% for p16, 60.0% for DAPK, and 58.0% for RAR beta gene, with significant differences (P < 0.05) when compared with those in the corresponding nonmalignant tissues(12.5%, 11.5% and 15.0%) respectively. p16 gene methylation in tumor tissue was associated with age significantly in unconditional logistic regression analysis (P < 0.01) and histologic type (P < 0.05). DAPK gene methylation in tumor tissue was associated significantly with age (P < 0.05), gender (P < 0.05) and clinical type (P < 0.05). RAR beta gene methylation in tumor tissue was associated with clinical type (P < 0.05) and tumor stage (P < 0.05) significantly. The interaction odds ratio (OR) for the gene-gene interaction in tumor tissue between p16 and DAPK was 1.987 (95%CI:1.055-3.743). The results of the gene-smoking analyses revealed that a relationship existed between cigarette smoking and p16 gene methylation (OR = 3.139, 95%CI: 1.046-9.419), the OR for the relationship of DAPK gene methylation and cigarette smoking was 3.585(95%CI: 1.270-10.123) in tumor tissue. The RAR beta gene methylation did not differ based on the smoking status of patients in tumor tissue.</p><p><b>CONCLUSION</b>The p16, DAPK and RAR beta genes methylation are strongly associated with clinical data of non-small cell lung cancer, and methylation of p16 and DAPK genes are associated with tobacco smoking.</p>

Death-associated protein kinase is underexpressed in high-grade oral squamous cell carcinoma / La expresión de la proteína quinasa asociada a muerte celular (DAP quinasa) está reducida en carcinoma de células escamosas oral de alto grado

An immunohistochemical analysis of 40 cases of oral squamous cell carcinoma was performed to evaluate the relationship between the expression pattern of death-associated protein kinase (DAPk) positive cells with the histological malignancy grading of these lesions. According to our results, eleven cases (27.5 percent) were high-grade malignancy tumours and 29 (72.5 percent) were low-grade ones. We found that 92.86 percent of the low-grade tumours were positive to anti-DAP kinase antibody whereas only 7.14 percent of the high-grade tumours presented positivity, and this difference was statistically significant (p<0.01). Sixteen (55.2 percent) of the low-grade carcinomas exhibited moderate immunoreactivity whereas ten cases (34.5 percent) showed weak staining and three cases (10.3 percent) were negative tumours. Immunostaining was lacking in nine (81.8 percent) of the high-grade carcinomas and "weak" in the two (18.2 percent) remaining cases. Thus, DAPk expression is significantly decreased in high-grade oral carcinomas, and evidences indicate that it might be related to the severity of cytological atypia.

Fue realizado un análisis inmunohistoquímico de 40 casos de carcinoma oral de células escamosas para evaluar la relación entre el patrón de expresión de la proteína quinasa (DAPK) asociada a la muerte celular y la clasificación histológica de malignidad de estas lesiones. Según nuestros resultados, 11 casos (27,5 por ciento) eran tumores de alto grado de malignidad y 29 (72,5 por ciento) de bajo grado. Se encontró que 92,86 por ciento de los tumores de bajo grado de malignidad fueron eran positivos para anticuerpos anti-DAP-quinasa, mientras que sólo 7,14 por ciento de los tumores de alto grado presentaron positividad, esta diferencia fue estadísticamente significativa (p <0,01). En 16 casos (55,2 por ciento) los carcinomas de bajo grado de malignidad mostraron inmunorreactividad moderada mientras que 10 casos (34,5 por ciento) mostraron una tinción débil y 3 casos (10,3 por ciento) fueron negativos. La inmunotinción estuvo ausente en 9 (81,8 por ciento) de los carcinomas de alto grado y "débil" grado de malignidad en los 2 (18,2 por ciento) casos restantes. Así, la expresión DAPK se redujo significativamente en los carcinomas orales de alto grado y las evidencias indican que podría estar relacionado con la severidad de la atipia citológica.

Alteration of methylation status of death-associated protein kinase (dapk) gene promoter in patients with acute myeloid leukemia / 中国实验血液学杂志

This study was purposed to analyze the methylation status of death-associated protein kinase (dapk) gene promoter in Chinese patients with acute myeloid leukemia (AML) and its relationship with clinical features. The methylation-specific PCR (MSP) technique was used to detect dapk promoter methylation in bone marrow samples from 112 cases of AML. The results indicated that gene dapk promoter hypermethylation was detected in 82 cases (73.2%), but not in 13 control group. There was no correlation of dapk gene hypermethylation with sex, age, WBC counts, platelet counts, hematologic parameters, chromosomal abnormalities and different subtypes of AML patients. It is concluded that dapk gene hypermethylation may be a common molecular event in AML.

Reversion transcriptional expression of DAPK in bladder cancer T24 cells 5-aza-2'-deoxycytidine / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the methylation status of the promoter of resion death associated protein kinase (DAPK) gene in bladder cancer cell (T24), and study the effect of 5-aza-2'-deoxycytidine (5-aza-dc) on DAPK gene reactive expression in T24 and its inhibitory effect on T24.</p><p><b>METHODS</b>The bladder cancer cell T24 was treated with different doses of 5-aza-dc. The inhibitory effect and apoptosis rate were detected by MTT and flow cytometry, and the changes of DAPK mRNA and protein expression and the methylation status of DAPK promoter were assessed by RT-PCR, Western blotting, and methylation specific PCR, respectively.</p><p><b>RESULTS</b>The growth of bladder cancer cell was inhibited significantly and the maximal apoptosis rate detected by flow cytometry was (24.12-/+1.4)%. DAPK mRNA was not expressed in bladder cancer cell T24 in normal conditions. DAPK mRNA and protein re-expressed after 5-aza-dc (12.5 micromol/L) treatment in cell line T24 for 24 h, and DAPK promoter became unmethylated.</p><p><b>CONCLUSIONS</b>The promoter methylation can be an important factor for silencing the expression of DAPK in bladder cancer cell. 5-aza-dc can inhibit the growth and induce apoptosis of bladder cancer cells through reversing unmethylation status of DAPK promoter.</p>

Synergistic effect of rapamycin (RPM) and PD98059 on cell cycle and mTOR signal transduction in human colorectal cancer cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the synergistic effect of rapamycin (RPM) and PD98059 on human colorectal cancer cells and its potential mechanisms.</p><p><b>METHODS</b>Three human colorectal cancer cell lines SW480, HCT116 and HT29 were treated with RPM 10 nmol/L, PD98059 (10 micromol/L, 20 micromol/L, 40 micromol/L, 50 micromol/L), or RPM plus PD98059, respectively, and the sensitivity was analyzed by MTT assay. The cell cycle progression was evaluated by flow cytometry. Western blotting analysis was performed to examine the total and phosphorylated levels of mammalian target of rapamycin (mTOR) and its downstream translational signaling intermediates, 70 kDa ribosomal protein S6 kinase (p70s6k) and eukaryotic initiation factor 4E-binding protein 1 (4E-BP1).</p><p><b>RESULTS</b>Both RPM and PD98059 could inhibit viability of the three cell lines. The anti-proliferative effect of PD98059 exhibited a time/dose dependent manner and was strengthen by RPM. All the treatment with RPM, PD98059, and RPM + PD98059 induced arrest of cell cycle, although the arrest was confined at different cell cycle phases. In addition to their effect on proliferation and cell cycle, both inhibitors also reduced phosphorylation levels of mTOR, p70s6k, and 4E-BP1, as well as total 4E-BP1 levels in SW480 and HCT116 cells. That effect was reinforced when cells were treated with RPM plus PD98059 simultaneously, whereas total protein levels of mTOR and p70s6k remained unchanged.</p><p><b>CONCLUSION</b>RPM and PD98059 inhibit proliferation of colorectal cancer cells synergistically, and induce cell cycle arrest. The modulation of mammalian target of rapamycin signaling pathway is involved in its potential mechanisms.</p>

Effects of calcium and calmodulin dependent kinase against hypoxic neuronal injury / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the effects of calcium and calmodulin dependent kinase against hypoxic neuronal injury and its possible mechanisms.</p><p><b>METHODS</b>Embryonic cortical neurons of 17-day pregnant embryo Sprague-Dawley rats were cultured in vitro and the cultured neurons were randomly allocated into different groups that exposed to hypoxia or hypoxia +calcium channel antagonist. Nimodipine and MK-801 were used to block the L-voltage sensitive calcium channel and NMDA receptor respectively before hypoxia. The methyl thiazolyl tetrazolium (MTT) method was used to determine the cell viability. Fluo-4AM, an intracellular calcium indictor, was used to detect the changes of intracellular calcium after hypoxia. The expressions of CaMKII and CaMKIV were detected by Western blot.</p><p><b>RESULTS</b>The cell viability of the nimodipine or MK-801-treated groups was significantly higher than that of the untreated hypoxia group. The intracellular calcium level of the nimodipine-treated group decreased rapidly after hypoxia. Compared to nimodipine treatment, MK-801 treatment could inhibit hypoxia-induced calcium influx for a longer time. Nimodipine treatment decreased the CaMKII expression while MK-801 treatment decreased the CaMKIV expression.</p><p><b>CONCLUSIONS</b>Nimodipine and MK-801 protect neurons from hypoxic injury possibly by the inhibition of CaMKII and CaMKIV expressions respectively.</p>

N-methyl-D-aspartate receptors mediate diphosphorylation of extracellular signal-regulated kinases through Src family tyrosine kinases and Ca2+/calmodulin-dependent protein kinase II in rat hippocampus after cerebral ischemia / 神经科学通报·英文版

<p><b>OBJECTIVE</b>Extracellular signal-regulated kinases (ERKs) can be activated by calcium signals. In this study, we investigated whether calcium-dependent kinases were involved in ERKs cascade activation after global cerebral ischemia.</p><p><b>METHODS</b>Cerebral ischemia was induced by four-vessel occlusion, and the calcium-dependent proteins were detected by immunoblot.</p><p><b>RESULTS</b>Lethal-simulated ischemia significantly resulted in ERKs activation in N-methyl-D-aspartate (NMDA) receptor-dependent manner, accompanying with differential upregulation of Src kinase and Ca2+/calmodulin-dependent protein kinase II (CaMKII) activities. With the inhibition of Src family tyrosine kinases or CaMKII by administration of PP2 or KN62, the phosphorylation of ERKs was impaired dramatically during post-ischemia recovery. However, ischemic challenge also repressed ERKs activity when Src kinase was excessively activated.</p><p><b>CONCLUSION</b>Src family tyrosine kinases and CaMKII might be involved in the activation of ERKs mediated by NMDA receptor in response to acute ischemic stimuli in vivo, but the intense activation of Src kinase resulted from ischemia may play a reverse role in the ERKs cascade.</p>

Ras-MAPK signaling pathway activated via brain-derived neurotrophic factor / 生物医学工程学杂志

Brain-derived neurotrophic factor (BDNF)is the richest neurophin in brain tissue and may act as an activity-dependent neuronal survival factor. In vitro, BDNF plays an important role in preventing cortical neurons from hypoxia-induced neurotoxicity. It could induce a variety of cellular responses such as cell growth, survival, differentiation, and anti-apoptosis mainly via activating mitogen-activated protein kinase (MAPK) and Ca2+/calmodulin-dependent kinase (CaMK) signaling pathways. And among these multiple signaling pathways there is growing evidence of complicated cross talk.

Changes of learning, memory and levels of CaMKII, CaM mRNA, CREB mRNA in the hippocampus of chronic multiple-stressed rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The effect of chronic stress on cognitive functions has been one of the hot topic in neuroscience. But there has been much controversy over its mechanism. Such single stressor applied in the past could not simulate complicated living circumstances that people confronted with. The aim of this study was to investigate the effects of chronic multiple-stress on learning and memory as well as on the levels of calcium/calmodulin-dependent protein kinase II (CaMKII), calmodulin (CaM) mRNA, and cAMP-response element binding protein (CREB) mRNA in the hippocampus of rats.</p><p><b>METHODS</b>The rats were divided randomly into stressed and control groups. The stressed group was given chronic multiple-stress for 6 weeks to set up a chronic multiple-stressed model. The rats' performance of spatial learning and memory was tested using Morris Water Maze (MWM) and Y-maze. Meanwhile, the expressions of CaMKII, CaM mRNA and CREB mRNA of rats' hippocampus were detected by immunohistochemistry, Western blot and reverse transcription-polymerase chain reaction (RT-PCR), respectively. In addition, the width of synaptic cleft and the thickness of post-synaptic densities (PSD) were observed in the hippocampal CA3 region of rats by electron microscopy.</p><p><b>RESULTS</b>After exposure to chronic multiple-stress for 6 weeks, the ability of learning and memory of the stressed group was higher than that of the control group (P < 0.05, P < 0.01). The width of synaptic cleft was smaller and the thickness of PSD was larger in the hippocampal CA3 region of the stressed group than in that of the control group (P < 0.01). The CaMK II immunostaining of the stressed group was stronger than that of the control group in the stratum radiatum and oriens of the hippocampal CA1 and CA3, especially in the stratum oriens. Quantitative analysis indicated that the expression of CaMK II, CaM mRNA, and CREB mRNA in the hippocampus of the stressed group was higher than that of the control group (P < 0.05, P < 0.01).</p><p><b>CONCLUSIONS</b>The capacity of learning and memory can be enhanced after chronic multiple-stress. The increased levels of CaMK II, CaM mRNA, and CREB mRNA may contribute to the enhancing effect of chronic multiple-stress on learning and memory.</p>

CaMKIIdelta overexpression in hypertrophy and heart failure: cellular consequences for excitation-contraction coupling

Ca/calmodulin-dependent protein kinase IIdelta (CaMKIIdelta) is the predominant isoform in the heart. During excitation-contraction coupling (ECC) CaMKII phosphorylates several Ca-handling proteins including ryanodine receptors (RyR), phospholamban, and L-type Ca channels. CaMKII expression and activity have been shown to correlate positively with impaired ejection fraction in the myocardium of patients with heart failure and CaMKII has been proposed to be a possible compensatory mechanism to keep hearts from complete failure. However, in addition to these acute effects on ECC, CaMKII was shown to be involved in hypertrophic signaling, termed excitation-transcription coupling (ETC). Thus, animal models have shown that overexpression of nuclear isoform CaMKIIdeltaB can induce myocyte hypertrophy. Recent study from our laboratory has suggested that transgenic overexpression of the cytosolic isoform CaMKIIdeltaC in mice causes severe heart failure with altered intracellular Ca handling and protein expression leading to reduced sarcoplasmic reticulum (SR) Ca content. Interestingly, the frequency of diastolic spontaneous SR Ca release events (or opening of RyR) was greatly enhanced, demonstrating increased diastolic SR Ca leak. This was attributed to increased CaMKII-dependent RyR phosphorylation, resulting in increased and prolonged openings of RyR since Ca spark frequency could be reduced back to normal levels by CaMKII inhibition. This review focuses on acute and chronic effects of CaMKII in ECC and ETC. In summary, CaMKII overexpression can lead to heart failure and CaMKII-dependent RyR hyperphosphorylation seems to be a novel and important mechanism in ECC due to SR Ca leak which may be important in the pathogenesis of heart failure.

Effects of water-soluble antioxidants and MAPKK/MEK inhibitor on curcumin-induced apoptosis in HL-60 human leukemic cells.

Curcumin is the main biologically active phytochemical compound in turmeric. It has been shown to have anticarcinogenic activity. The aims of the study were to identify the mechanism of apoptosis of HL-60 human promyelocytic leukemic cells induced by curcumin and to determine the effects of water-soluble antioxidants, ascorbic acid, Trolox (a water-soluble form of vitamin E), glutathione (GSH) and N-acetylcysteine (NAC) on this process. HL-60 cells were incubated with curcumin for 24 h and apoptotic cells were quantitated by flow cytometry following staining with annexin V-FITC and propidium iodide. Curcumin-treated HL-60 cells produced reactive oxygen species as detected by the dichlorofluorescein fluorescent assay. Apoptosis occurred via the mitochondria pathway as curcumin reduced mitochondrial membrane potential in a dose-dependent manner. In the presence of 10 microM curcumin, vitamin C (56 nM-5.6 microM) inhibited apoptosis of HL-60 cells; GSH at low concentration (1 microM) reduced apoptosis but had no effect at higher concentrations (10, 100 microM); and Trolox and NAC at 10 and 100 microM, respectively, enhanced apoptosis, but this effect was abolished at higher concentration (1 mM) of NAC. MAPKK/MEK inhibitor PD98059, enhanced curcumin-induced HL-60 apoptotic cell death.

PD98059 inhibits expression of pERK1 protein and collagen alpha1(I) mRNA in rat pancreatic stellate cells activated by platelet-derived growth factor.

OBJECTIVE: Pancreatic stellate cells (PSC) are considered as the principal effector cells in pancreatic fibrosis. We studied the role of platelet-derived growth factor (PDGF) in the activation of PSC. METHODS: Cultured rat PSC were co-incubated with PDGF-BB (25 ng/mL) and different doses (0-40 ng/mL) of PD98059, a specific inhibitor of extracellular signal-regulated kinase (ERK). Expressions of p ERK1 protein and of collagen a1(I) mRNA were measured. RESULTS: Expression of p ERK1 protein was up-regulated by PDGF-BB, and was down-regulated in a dose-dependent manner by PD98059. Expression of collagen a1(I) mRNA also showed an increase with PDGF-BB and non-dose-dependent inhibition by PD98059. CONCLUSION: Our findings suggest that PSC activation is mediated by PDGF signal pathway, and ERK1 protein plays an important role in this activation.