DDRT-PCR approaches applied for preeminent results in the isolation of DETs from fish brain tissues / Aplicação de abordagens de DDRT-PCR para aprimoramento de resultados no isolamento de DETs a partir de tecido cerebral de peixes

Differential Display (DD) is a technique widely used in studies of differential expression. Most of these analyses, especially those involving fish species, are restricted to species from North America and Europe or to commercial species, as salmonids. Studies related to South American fish species are underexplored. Thus, the present work aimed to describe DD technique modifications in order to improve outcomes related to the isolation of DETs (Differentially Expressed Transcripts), using Leporinus macrocephalus, a large commercially exploited South American species, as a fish design. Different DDRT-PCR approaches were applied to brain samples and the products of the reactions were analyzed on 6% polyacrylamide gels stained with 0.17% Silver Nitrate (AgNO3). The use of PCR reactions under high stringency conditions and longer oligonucleotides based on VNTR (Variable Number of Tandem Repeats) core sequences led to better results when compared to low stringency PCR conditions and the use of decamer oligonucleotides. The improved approach led to the isolation of differentially expressed transcripts on adult males and females of L. macrocephalus. This study indicates that some modifications on the DDRT-PCR method can ensure isolation of DETs from different fish tissues and the development of robust data related to this approach.

Display Diferencial (DD) é uma técnica amplamente utilizada em estudos de expressão diferencial. A maioria desses estudos envolvendo espécies de peixes está restrita a espécies da América do Norte e Europa ou a espécies comerciais, como os salmoniformes. Estudos relacionados a peixes da América do Sul são ainda pouco explorados. Desse modo, o presente trabalho teve como objetivo descrever modificações na técnica de DD, a fim de melhorar os resultados relacionados ao isolamento de DETs (Transcritos Diferencialmente Expressos), utilizando Leporinus macrocephalus, peixe explorado comercialmente na América do Sul, como espécie para tal delineamento. Diferentes abordagens de DDRT-PCR foram desenvolvidas a partir de amostras de tecido cerebral e os produtos das reações foram analisados em gel de poliacrilamida 6% corados com 0,17% de nitrato de Prata (AgNO3). A utilização de reações de PCR sob condições de elevada estringência e oligonucleotídeos mais longos, com base em sequências cerne de VNTR (Número Variável de Repetições em Tandem), mostrou melhores resultados quando comparada a condições de baixa estringência e ao uso de oligonucleotídeos decâmeros. A estratégia empregada permitiu o isolamento de transcritos diferencialmente expressos em machos e fêmeas adultos de L. macrocephalus. Este estudo evidencia que modificações no método de DDRT-PCR garantem o melhor isolamento de DETs a partir de diferentes tecidos de peixes e asseguram a obtenção de dados mais sólidos relacionados a essa abordagem.

Relationship between the climbing up and climbing down stairs domain scores on the FES-DMD, the score on the Vignos Scale, age and timed performance of functional activities in boys with Duchenne muscular dystrophy / Relação entre escore FES-DMD-subir e descer escada com escore Escala Vignos, idade e tempo de realização das atividades em meninos com Distrofia Muscular de Duchenne

BACKGROUND: Knowing the potential for and limitations of information generated using different evaluation instruments favors the development of more accurate functional diagnoses and therapeutic decision-making. OBJECTIVE: To investigate the relationship between the number of compensatory movements when climbing up and going down stairs, age, functional classification and time taken to perform a tested activity (TA) of going up and down stairs in boys with Duchenne muscular dystrophy (DMD). METHOD: A bank of movies featuring 30 boys with DMD performing functional activities was evaluated. Compensatory movements were assessed using the climbing up and going down stairs domain of the Functional Evaluation Scale for Duchenne Muscular Dystrophy (FES-DMD); age in years; functional classification using the Vignos Scale (VS), and TA using a timer. Statistical analyses were performed using the Spearman correlation test. RESULTS: There is a moderate relationship between the climbing up stairs domain of the FES-DMD and age (r=0.53, p=0.004) and strong relationships with VS (r=0.72, p=0.001) and TA for this task (r=0.83, p<0.001). There were weak relationships between the going down stairs domain of the FES-DMD-going down stairs with age (r=0.40, p=0.032), VS (r=0.65, p=0.002) and TA for this task (r=0.40, p=0.034). CONCLUSION: These findings indicate that the evaluation of compensatory movements used when climbing up stairs can provide more relevant information about the evolution of the disease, although the activity of going down stairs should be investigated, with the aim of enriching guidance and strengthening accident prevention. Data from the FES-DMD, age, VS and TA can be used in a complementary way to formulate functional diagnoses. Longitudinal studies and with broader age groups may supplement this information. .

CONTEXTUALIZAÇÃO: Conhecer as potencialidades e limitações das informações geradas por diferentes instrumentos de avaliação favorece o desenvolvimento mais preciso do diagnóstico funcional e da tomada de decisão terapêutica. OBJETIVO : Investigar a relação entre o número de movimentos compensatórios ao subir e descer escadas, idade, classificação funcional e tempo de realização de atividade (TA) em meninos com Distrofia Muscular de Duchenne (DMD). MÉTODO : Foi utilizado banco de filmes de 30 meninos com DMD realizando atividades funcionais. Os movimentos compensatórios foram avaliados pela Escala de Avaliação Funcional para Distrofia Muscular de Duchenne (FES-DMD), domínio subir e descer escada; a idade, mensurada em anos; a classificação funcional foi pesquisada pela Escala de Vignos (EV), e o TA foi cronometrado. Foi utilizado o teste de correlação de Spearman. RESULTADOS : Existe moderada relação entre a FES-DMD-subir escada e a idade (r=0,53, p=0,004) e forte relação com a EV (r=0,72, p=0,001) e TA dessa tarefa (r=0,83, p<0,001). Houve fraca relação entre a FES-DMD-descer escada e a idade (r=0,40, p=0,032), EV (r=0,65, p=0,002) e o TA dessa tarefa (r=0,40, p=0,034). CONCLUSÃO : Esses achados indicam que a avaliação da tarefa de subir escada pode trazer informações mais relevantes sobre a evolução da doença, embora a atividade de descer escada deva ser pesquisada visando à orientação e prevenção de acidentes. A utilização conjunta de dados provenientes da FES-DMD, da idade e do TA pode se complementar para formulação do diagnóstico funcional. Estudos longitudinais e com outras faixas etárias mais amplas podem complementar tal informação. .

Use of aglepristone for the treatment of P4 induced insulin resistance in dogs

Insulin resistance (IR) in dogs is suspected when hyperglycemia is present despite administration of insulin doses greater than 1.0 to 1.5 UI/kg. IR is caused by increases in counter regulatory hormones concentrations (glucagon, glucocorticoids, catecholamines and growth hormone). This study was conducted to investigate the use of aglepristone (RU 46534), a P4 receptor antagonist, for the treatment of IR diabetes mellitus in bitches during the luteal phase. All animals were treated with porcine insulin zinc suspension (Caninsulin) and aglepristone (Alizin) 10 mg/kg subcutaneously at day 1, 2, 9 and 17 from diagnosis. At day 5, no significant variation in glycemia was shown. At day 12 and 20, serum glucose concentrations were significant lower (p < 0.05). From day 12 the insulin dose was reduced to 0.8 IU BID. Insulin was reduced in the following weeks and glycemia was controlled.

Ultrastructural changes of erythrocytes in whole blood after exposure to prospective in silico-designed anticancer agents: a qualitative case study

BACKGROUND: Novel, in silico-designed anticancer compounds were synthesized in our laboratory namely, 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10),15-tetraen-17-ol (ESE-15-ol) and 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10)16-tetraene (ESE-16). These compounds were designed to have improved bioavailability when compared to their source compound, 2-methoxyestradiol. This theoretically would be due to their increased binding affinity to carbonic anhydrase II, present in erythrocytes. Since the novel compounds under investigation are proposed to be transported within erythrocytes bound to carbonic anhydrase II, the morphological effect which they may exert on whole blood and erythrocytes is of great significance. A secondary outcome included revision of previously reported procedures for the handling of the whole blood sample. The purpose of this study was twofold. Firstly, the ultrastructural morphology of a healthy female's erythrocytes was examined via scanning electron microscopy (SEM) after exposure to the newly in silico-designed compounds. Morphology of erythrocytes following exposure to ESE-15-ol and ESE-16 for 3 minutes and 24 hours at 22°C were described with the use of SEM. The haemolytic activity of the compounds after 24 hours exposure were also determined with the ex vivo haemolysis assay. Secondly, storage conditions of the whole blood sample were investigated by determining morphological changes after a 24 hour storage period at 22°C and 37°C. RESULTS: No significant morphological changes were observed in the erythrocyte morphology after exposure to the novel anticancer compounds. Storage of the whole blood samples at 37°C for 24 hours resulted in visible morphological stress in the erythrocytes. Erythrocytes incubated at 22°C for 24 hours showed no structural deformity or distress. CONCLUSIONS: From this research the optimal temperature for ex vivo exposure of whole blood samples to ESE-15-ol and ESE-16 for 24 hours was determined to be 22°C. Data from this study revealed the potential of these compounds to be applied to ex vivo study techniques, since no damage occurred to erythrocytes ultrastructure under these conditions. As no structural changes were observed in erythrocytes exposed to ESE-15-ol and ESE-16, further ex vivo experiments will be conducted into the potential effects of these compounds on whole blood. Optimal incubation conditions up to 24 hours for whole blood were established as a secondary outcome.

Postcoital administration of asoprisnil inhibited embryo implantation and disturbed ultrastructure of endometrium in implantation window in mice / 华中科技大学学报（医学）（英德文版）

Asoprisnil, a member of the selective progesterone receptor modulators, exerts high progesterone receptor selectivity, endometrial targeted advantages and significant anti-implantation effect in rats. The purpose of this study was to confirm the anti-implantation effect of asoprisil, investigate the ultrastructural changes of the peri-implantation endometrium in mice and explore the effect of asoprisnil on endometrial receptivity and its targeted contraceptive proficiency. Post-coitus mice were administered with different dosages (0.2, 0.1, 0.05 mg·g(-1)·day(-1)) of asoprisnil from day 1 of pregnancy to day 3. Then 3 animals in each group were killed on day 5 of pregnancy, and uteri were collected to examine the ultrastructural changes of endometria under a transmission electron microscope (TEM). A total of 80 animals were sacrificed on day 8 of pregnancy, and the uterine horns were examined for the presence or absence of nidation sites and the number of implantation embryos. The results showed that the implantation rate and the average number of implantation embryos in asoprisnil groups were statistically significantly decreased as compared with the vehicle control group (P<0.05). The TEM results revealed that, in vehicle control group, the tight junction between the luminal epithelia cells was short and straight, the gap was wide; the luminal epithelia cells were covered with plenty of short, clavate and neatly arranged microvilli; the endometril stromal cells were large with plenty of cytoplasm, and showed significant decidual change; there was more than one nucleus in stromal cells, and the karyotheca was integrity. In low dosage and high dosage asoprisnil groups, the tight junction was longer and more curve than in the vehicle control group; microvilli were uneven and asymmetrically distributed in luminal epithelia; the stromal cells were small and the decidual change was not significant; there were karyopyknosis and karyolysis in stromal cells; there were abnormal thick-wall vessels in the endometrium. It was suggested that asoprisnil changed the ultrastructure of the endometrium in implantation window, disturbed the endometrial receptivity and finally resulted in embryo implantation failure.

Activation of Lysophosphatidic Acid Receptor Is Coupled to Enhancement of Ca(2+)-Activated Potassium Channel Currents

The calcium-activated K+ (BKCa) channel is one of the potassium-selective ion channels that are present in the nervous and vascular systems. Ca2+ is the main regulator of BKCa channel activation. The BKCa channel contains two high affinity Ca2+ binding sites, namely, regulators of K+ conductance, RCK1 and the Ca2+ bowl. Lysophosphatidic acid (LPA, 1-radyl-2-hydroxy-sn-glycero-3-phosphate) is one of the neurolipids. LPA affects diverse cellular functions on many cell types through G protein-coupled LPA receptor subtypes. The activation of LPA receptors induces transient elevation of intracellular Ca2+ levels through diverse G proteins such as Galphaq/11, Galphai, Galpha12/13, and Galphas and the related signal transduction pathway. In the present study, we examined LPA effects on BKCa channel activity expressed in Xenopus oocytes, which are known to endogenously express the LPA receptor. Treatment with LPA induced a large outward current in a reversible and concentration-dependent manner. However, repeated treatment with LPA induced a rapid desensitization, and the LPA receptor antagonist Ki16425 blocked LPA action. LPA-mediated BKCa channel activation was also attenuated by the PLC inhibitor U-73122, IP3 inhibitor 2-APB, Ca2+ chelator BAPTA, or PKC inhibitor calphostin. In addition, mutations in RCK1 and RCK2 also attenuated LPA-mediated BKCa channel activation. The present study indicates that LPA-mediated activation of the BKCa channel is achieved through the PLC, IP3, Ca2+, and PKC pathway and that LPA-mediated activation of the BKCa channel could be one of the biological effects of LPA in the nervous and vascular systems.

Signaling Pathway of Lysophosphatidic Acid-Induced Contraction in Feline Esophageal Smooth Muscle Cells

Lysolipids such as LPA, S1P and SPC have diverse biological activities including cell proliferation, differentiation, and migration. We investigated signaling pathways of LPA-induced contraction in feline esophageal smooth muscle cells. We used freshly isolated smooth muscle cells and permeabilized cells from cat esophagus to measure the length of cells. Maximal contraction occurred at 10(-6) M and the response peaked at 30s. To identify LPA receptor subtypes in cells, western blot analysis was performed with antibodies to LPA receptor subtypes. LPA1 and LPA3 receptor were detected at 50 kDa and 44 kDa. LPA-induced contraction was almost completely blocked by LPA receptor (1/3) antagonist KI16425. Pertussis toxin (PTX) inhibited the contraction induced by LPA, suggesting that the contraction is mediated by a PTX-sensitive G protein. Phospholipase C (PLC) inhibitors U73122 and neomycin, and protein kinase C (PKC) inhibitor GF109203X also reduced the contraction. The PKC-mediated contraction may be isozyme-specific since only PKCepsilon antibody inhibited the contraction. MEK inhibitor PD98059 and JNK inhibitor SP600125 blocked the contraction. However, there is no synergistic effect of PKC and MAPK on the LPA-induced contraction. In addition, RhoA inhibitor C3 exoenzyme and ROCK inhibitor Y27632 significantly, but not completely, reduced the contraction. The present study demonstrated that LPA-induced contraction seems to be mediated by LPA receptors (1/3), coupled to PTX-sensitive G protein, resulting in activation of PLC, PKC-epsilon pathway, which subsequently mediates activation of ERK and JNK. The data also suggest that RhoA/ROCK are involved in the LPA-induced contraction.

Effects of Histamine on Cultured Interstitial Cells of Cajal in Murine Small Intestine

Interstitial cells of Cajal (ICCs) are the pacemaker cells in the gastrointestinal tract, and histamine is known to regulate neuronal activity, control vascular tone, alter endothelial permeability, and modulate gastric acid secretion. However, the action mechanisms of histamine in mouse small intestinal ICCs have not been previously investigated, and thus, in the present study, we investigated the effects of histamine on mouse small intestinal ICCs, and sought to identify the receptors involved. Enzymatic digestions were used to dissociate ICCs from small intestines, and the whole-cell patch-clamp configuration was used to record potentials (in current clamp mode) from cultured ICCs. Histamine was found to depolarize resting membrane potentials concentration dependently, and whereas 2-PEA (a selective H1 receptor agonist) induced membrane depolarizations, Dimaprit (a selective H2-agonist), R-alpha-methylhistamine (R-alpha-MeHa; a selective H3-agonist), and 4-methylhistamine (4-MH; a selective H4-agonist) did not. Pretreatment with Ca(2+)-free solution or thapsigargin (a Ca(2+)-ATPase inhibitor in endoplasmic reticulum) abolished the generation of pacemaker potentials and suppressed histamine-induced membrane depolarization. Furthermore, treatments with U-73122 (a phospholipase C inhibitor) or 5-fluoro-2-indolyl des-chlorohalopemide (FIPI; a phospholipase D inhibitor) blocked histamine-induced membrane depolarizations in ICCs. On the other hand, KT5720 (a protein kinase A inhibitor) did not block histamine-induced membrane depolarization. These results suggest that histamine modulates pacemaker potentials through H1 receptor-mediated pathways via external Ca2+ influx and Ca2+ release from internal stores in a PLC and PLD dependent manner.

Effects of Inositol 1,4,5-triphosphate on Osteoclast Differentiation in RANKL-induced Osteoclastogenesis

The receptor activator of NF-kappaB ligand (RANKL) signal is an activator of tumor necrosis factor receptor-associated factor 6 (TRAF6), which leads to the activation of NF-kappaB and other signal transduction pathways essential for osteoclastogenesis, such as Ca2+ signaling. However, the intracellular levels of inositol 1,4,5-trisphosphate (IP3) and IP3-mediated cellular function of RANKL during osteoclastogenesis are not known. In the present study, we determined the levels of IP3 and evaluated IP3-mediated osteoclast differentiation and osteoclast activity by RANKL treatment of mouse leukemic macrophage cells (RAW 264.7) and mouse bone marrow-derived monocyte/macrophage precursor cells (BMMs). During osteoclastogenesis, the expression levels of Ca2+ signaling proteins such as IP3 receptors (IP3Rs), plasma membrane Ca2+ ATPase, and sarco/endoplasmic reticulum Ca2+ ATPase type2 did not change by RANKL treatment for up to 6 days in both cell types. At 24 h after RANKL treatment, a higher steady-state level of IP3 was observed in RAW264.7 cells transfected with green fluorescent protein (GFP)-tagged pleckstrin homology (PH) domains of phospholipase C (PLC) delta, a probe specifically detecting intracellular IP3 levels. In BMMs, the inhibition of PLC with U73122 [a specific inhibitor of phospholipase C (PLC)] and of IP3Rs with 2-aminoethoxydiphenyl borate (2APB; a non-specific inhibitor of IP3Rs) inhibited the generation of RANKL-induced multinucleated cells and decreased the bone-resorption rate in dentin slice, respectively. These results suggest that intracellular IP3 levels and the IP3-mediated signaling pathway play an important role in RANKL-induced osteoclastogenesis.

Dexmedetomidine-induced contraction of isolated rat aorta is dependent on extracellular calcium concentration / 대한마취과학회지

BACKGROUND: Dexmedetomidine is a highly selective alpha2-adrenoceptor agonist that is widely used for sedation and analgesia during the perioperative period. Intravenous administration of dexmedetomidine induces transient hypertension due to vasoconstriction via the activation of the alpha2-adrenoceptor on vascular smooth muscle. The goal of this in vitro study is to investigate the calcium-dependent mechanism underlying dexmedetomidine-induced contraction of isolated endothelium-denuded rat aorta. METHODS: Isolated endothelium-denuded rat thoracic aortic rings were suspended for isometric tension recording. Cumulative dexmedetomidine concentration-response curves were generated in the presence or absence of the following inhibitors: alpha2-adrenoceptor inhibitor rauwolscine; voltage-operated calcium channel blocker verapamil (5 x 10(-7), 10(-6) and 5 x 10(-5) M); purported inositol 1,4,5-trisphosphate receptor blocker 2-aminoethoxydiphenylborate (5 x 10(-6), 10(-5) and 5 x 10(-5) M); phospholipase C inhibitor U-73122 (10(-6) and 3 x 10(-6) M); and store-operated calcium channel inhibitor gadolinium chloride hexahydrate (Gd3+; 5 x 10(-6) M). Dexmedetomidine concentration-response curves were also generated in low calcium concentrations (1 mM) and calcium-free Krebs solution. RESULTS: Rauwolscine, verapamil, and 2-aminoethoxydiphenylborate attenuated dexmedetomidine-induced contraction in a concentration-dependent manner. Low calcium concentrations attenuated dexmedetomidine-induced contraction, and calcium-free Krebs solution nearly abolished dexmedetomidine-induced contraction. However, U-73122 and Gd3+ had no effect on dexmedetomidine-induced contraction. CONCLUSIONS: Taken together, these results suggest that dexmedetomidine-induced contraction is primarily dependent on extracellular calcium concentrations that contribute to calcium influx via voltage-operated calcium channels of isolated rat aortic smooth muscle. Dexmedetomidine-induced contraction is mediated by alpha2-adrenoceptor stimulation. Dexmedetomidine-induced contraction appears to be partially mediated by calcium release from the sarcoplasmic reticulum.

Oxidized Low-density Lipoprotein- and Lysophosphatidylcholine-induced Ca2+ Mobilization in Human Endothelial Cells

The effects of oxidized low-density lipoprotein (OxLDL) and its major lipid constituent lysophosphatidylcholine (LPC) on Ca2+ entry were investigated in cultured human umbilical endothelial cells (HUVECs) using fura-2 fluorescence and patch-clamp methods. OxLDL or LPC increased intracellular Ca2+ concentration ([Ca2+]i), and the increase of [Ca2+]i by OxLDL or by LPC was inhibited by La3+ or heparin. LPC failed to increase [Ca2+]i in the presence of an antioxidant tempol. In addition, store-operated Ca2+ entry (SOC), which was evoked by intracellular Ca2+ store depletion in Ca2+-free solution using the sarcoplasmic reticulum Ca2+ pump blocker, 2, 5-di-t-butyl-1, 4-benzohydroquinone (BHQ), was further enhanced by OxLDL or by LPC. Increased SOC by OxLDL or by LPC was inhibited by U73122. In voltage-clamped cells, OxLDL or LPC increased [Ca2+]i and simultaneously activated non-selective cation (NSC) currents. LPC-induced NSC currents were inhibited by 2-APB, La3+ or U73122, and NSC currents were not activated by LPC in the presence of tempol. Furthermore, in voltage-clamped HUVECs, OxLDL enhanced SOC and evoked outward currents simultaneously. Clamping intracellular Ca2+ to 1 micrometer activated large-conductance Ca2+-activated K+ (BKCa) current spontaneously, and this activated BKCa current was further enhanced by OxLDL or by LPC. From these results, we concluded that OxLDL or its main component LPC activates Ca2+-permeable Ca2+-activated NSC current and BKCa current simultaneously, thereby increasing SOC.

Interleukin-1beta promotes the expression of monocyte chemoattractant protein-1 in human aorta smooth muscle cells via multiple signaling pathways

Monocyte chemoattractant protein-1 (MCP1) plays a key role in monocyte/macrophage infiltration to the sub-endothelial space of the blood vessel wall, which is a critical initial step in atherosclerosis. In this study, we examined the intracellular signaling pathway of IL-1beta-induced MCP1 expression using various chemical inhibitors. The pretreatment of a phosphatidylcholine (PC)-specific PLC (PC-PLC) inhibitor (D609), PKC inhibitors, or an NF-kappaB inhibitor completely suppressed the IL-1beta-induced MCP1 expression through blocking NF-kappaB translocation to the nucleus. Pretreatment with inhibitors of tyrosine kinase or PLD partially suppressed MCP1 expression and failed to block nuclear NF-kappaB translocation. These results suggest that IL-1beta induces MCP1 expression through activation of NF-kappaB via the PC-PLC/PKC signaling pathway.

Development of Position Encoding Circuit for a Multi-Anode Position Sensitive Photomultiplier Tube / 핵의학분자영상

PURPOSE: The goal of this paper is to present the design and performance of a position encoding circuit for 16 x 16 array of position sensitive multi-anode photomultiplier tube for small animal PET scanners. This circuit which reduces the number of readout channels from 256 to 4 channels is based on a charge division method utilizing a resistor array. MATERIALS AND METHODS: The position encoding circuit was simulated with PSpice before fabrication. The position encoding circuit reads out the signals from H9500 flat panel PMTs (Hamamatsu Photonics K.K., Japan) on which 1.5 x 1.5 x 7.0 mm3 L0.9GSO (Lu1.8Gd0.2SiO5:Ce) crystals were mounted. For coincidence detection, two different PET modules were used. One PET module consisted of a 29 x 29 L0.9GSO crystal layer, and the other PET module two 28 x 28 and 29 x 29 L0.9GSO crystal layers which have relative offsets by half a crystal pitch in x- and y-directions. The crystal mapping algorithm was also developed to identify crystals. RESULTS: Each crystal was clearly visible in flood images. The crystal identification capability was enhanced further by changing the values of resistors near the edge of the resistor array. Energy resolutions of individual crystal were about 11.6%(SD 1.6). The flood images were segmented well with the proposed crystal mapping algorithm. CONCLUSION: The position encoding circuit resulted in a clear separation of crystals and sufficient energy resolutions with H9500 flat-panel PMT and L0.9GSO crystals. This circuit is good enough for use in small animal PET scanners.

Role of phospholipase C-gamma1 signaling pathway in H(2)O(2)-induced apoptosis of PC12 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the role of phospholipase C-gamma1 (PLC-gamma1) signaling pathway in H(2)O(2)-induced apoptosis of PC12 cells.</p><p><b>METHODS</b>PC12 cells were exposed to 50 micromol/L H(2)O(2) after pretreatment with 10 micromol/L U73122, a specific PLC-gamma1 inhibitor. Hoechst/PI double staining was performed to observe the morphological changes of the cells under light microscope. MTT assay was used to evaluate the cell viability, and the percentage of apoptotic cells was analyzed by flow cytometry. DNA fragmentation assay was carried out to characterize the cell apoptosis.</p><p><b>RESULTS</b>After inhibition of the PLC-gamma1 signaling pathway with 10 micromol/L U73122, PC12 cells showed obvious apoptotic morphology, the viable cells decreased significantly, and the percentage of apoptotic cells rose to 35.7%. PC12 cells treated with U73122 presented with a distinct DNA ladder on electrophoresis resulting from DNA cleavage in the apoptotic cells.</p><p><b>CONCLUSION</b>PLC-gamma1 signaling pathway plays an important protective role in H(2)O(2)-induced PC12 cell apoptosis.</p>

Suppressive effect in vitro of resveratrol on ADP induced human platelet aggregation and its active mechanism / 药学学报

Resveratrol (RESV) is a polyphenolic compound existed in native plants such as grape, fleeceflower root, and peanut, etc. The aim of this study was to investigate the effects in vitro of RESV on adenosine diphosphate (ADP)-induced platelet aggregation, platelet membrane-bound fibrinogen (PFig) its mechanism of action. The effects of RESV and phospholipase Cbeta inhibitor (U73122) on ADP-induced healthy human volunteers platelet aggregation, PFig, and the expression of phospho-phospholipase Cbeta3 (P-PLCbeta3) and total-phospholipase Cbeta3 (T-PLCbeta3) were studied with platelet aggregometer, flow cytometry and Western blotting, respectively. Compared with control group, RESV at 25, 50 and 100 micromol x L(-1) inhibited ADP-induced platelet aggregation and PFig in a dose dependent manner, and RESV at 25 micromol x L(-1) obviously reduced expression of P-PLCbeta3 and ratio of P-PLCbeta3 to T-PLCbeta3 in platelet of healthy human volunteers. Furthermore, RESV and U73122 had additive effect in inhibiting platelet aggregation and PFig. All these suggested that RESV inhibited platelet aggregation and PFig induced by ADP partly through decreasing the activity of PLCbeta of platelets, and that RESV had definite effect of antiplatelet and might be developed as a novel antithrombotic agent.

Acidic pH-activated Cl- Current and Intracellular Ca2+ Response in Human Keratinocytes

The layers of keratinocytes form an acid mantle on the surface of the skin. Herein, we investigated the effects of acidic pH on the membrane current and [Ca2+](c) of human primary keratinocytes from foreskins and human keratinocyte cell line (HaCaT). Acidic extracellular pH (pHe< or =5.5) activated outwardly rectifying Cl- current (I(Cl,pH)) with slow kinetics of voltage-dependent activation. I(Cl,pH) was potently inhibited by an anion channel blocker 4,4`-diisothiocyanostilbene-2,2`-disulphonic acid (DIDS, 73.5% inhibition at 1micrometer). I(Cl,pH) became more sensitive to pHe by raising temperature from 24degrees C to 37degrees C. HaCaT cells also expressed Ca2+ -activated Cl- current (I(Cl,Ca)), and the amplitude of I(Cl,Ca) was increased by relatively weak acidic pHe (7.0 and 6.8). Interestingly, the acidic pHe (5.0) also induced a sharp increase in the intracellular [Ca2+] (delta[Ca2+](acid)) of HaCaT cells. The delta[Ca2+](acid) was independent of extracellular Ca2+, and was abolished by the pretreatment with PLC inhibitor, U73122. In primary human keratinocytes, 5 out of 28 tested cells showed delta[Ca2+](acid). In summary, we found I(Cl,pH) and delta[Ca2+](acid) in human keratinocytes, and these ionic signals might have implication in pathophysiological responses and differentiation of epidermal keratinocytes.

Endothelin 1 protects HN33 cells from serum deprivation-induced neuronal apoptosis through Ca2+-PKCalpha-ERK pathway

Endothelins (ETs), which were originally found to be potent vasoactive transmitters, were known to be implicated in nervous system, but the mode of mechanism remains unclear. ETs (ET-1, ET-2, and ET-3) were added to HN33 (mouse hippocampal neuron chi neuroblastoma) cells. Among the three types of ET, only ET-1 increased the intracellular calcium levels in a PLC dependent manner with the induction of ERK 1/2 activation. As the result of ET-1 exposure, the survival rate of HN33 cells and the PKCalpha translocation into the plasma membrane were increased. We suggest that ET-1 participated in the neuroprotective effect involving the calcium-PKCalpha-ERK1/2 pathway.

Role of interleukin-3 and signaling pathways on beta-thalassemia/HbE erythroid progenitor cell in culture.

In order to study the role of the cytokine interleukin-3 (IL-3) and its signaling pathways in erythropoiesis of beta-thalassemia/HbE erythroid progenitor cells, CD34 positive cells were isolated from peripheral blood of patients and healthy subjects. After culturing the cells in the presence or absence of IL-3, cell viability was measured by trypan blue staining and apoptotic cells were analyzed by flow cytometry. After 7 days of culture the highest percent erythroid progenitor cell viability was obtained with cells from healthy subjects, while the lowest percentage was found in those from splenectomized beta-thalassemia/HbE. Viability of beta-thalassemia/HbE erythroid progenitor cells in the presence of IL-3 was higher than that of nonsupplemented cells. In addition, specific inhibitors of protein kinase C (Ro-318220), phospholipase C (U-73122) and Janus kinase 2 (AG-490) were used to investigate the involvement of signaling pathways in erythropoiesis. Percent apoptosis of erythroid progenitor cells from splenectomized beta-thalassemia/HbE subjects treated with RO-318220 was higher than those of nonsplenectomized beta-thalassemia/HbE and healthy subjects. Treatment with U-73122 resulted in enhanced percent apoptotic cells from normal and beta-thalassemia/HbE subjects. All these effects were independent of IL-3 treatment.

Phytosphingosine-1-phosphate stimulates chemotactic migration of L2071 mouse fibroblasts via pertussis toxin-sensitive G-proteins

Phytosphingosine-1-phosphate (PhS1P) was found to stimulate an intracellular calcium increase via phospholipase C but not pertussis toxin (PTX)- sensitive G-proteins in L2071 mouse fibroblasts. PhS1P also activated ERK and p38 kinase, and these activations by PhS1P were inhibited by PTX. Moreover, PhS1P stimulated the chemotactic migration of L2071 cells via PTX-sensitive Gi protein(s). In addition, the PhS1P-induced chemotactic migration of L2071 cells was also dramatically inhibited by LY294002 and SB203580 (inhibitors of phosphoinositide 3-kinase and p38 kinase, respectively). L2071 cells are known to express four S1P receptors, i.e., S1P1, S1P2, S1P3, and S1P4, and pretreatment with an S1P1 and S1P3 antagonist (VPC 23019) did not affect on PhS1P-induced chemotaxis. This study demonstrates that PhS1P stimulates at least two different signaling cascades, one is a PTX-insensitive but phospholipase C dependent intracellular calcium increase, and the other is a PTX-sensitive chemotactic migration mediated by phosphoinositide 3-kinase and p38 kinase.

Sensitization of human glioma SWO cell line to tumor necrosis factor-induced apoptosis by blocking phospholipase C-gamma1 signaling pathway / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the role of phospholipase C-gamma1 (PLC-gamma1) in tumor necrosis factor-alpha (TNF-alpha)-induced apoptosis of human glioma SWO cells.</p><p><b>METHODS</b>The PLC-gamma1 pathway was blocked by U73122 in SWO cells, and the inhibitory effect of TNF-alpha on SWO glioma cell proliferation with or without U73122 treatment was investigated by MTT assay. The cell apoptosis induced by TNF-alpha along or in combination with U73122 was detected by flow cytometry with PI staining. The expression of caspase-3 and Bcl-2 was detected by Western blotting.</p><p><b>RESULTS AND CONCLUSION</b>U73122 can sensitize SWO glioma cells to TNF-alpha-induced apoptosis. Blocking the PLC-gamma1 pathway may not induce apoptosis of SWO glioma cells, but can sensitize SWO glioma cells to small-dose TNF-alpha-induced apoptosis, the mechanism of which may involve down-regulation of bcl-2.</p>