Identification of phospholipase C β downstream effect on transient receptor potential canonical 1/4, transient receptor potential canonical 1/5 channels

Gα(q)-coupled receptor stimulation was implied in the activation process of transient receptor potential canonical (TRPC)1/4 and TRPC1/5 heterotetrameric channels. The inactivation occurs due to phosphatidylinositol 4,5-biphosphate (PI(4,5)P₂) depletion. When PI(4,5)P₂ depletion was induced by muscarinic stimulation or inositol polyphosphate 5-phosphatase (Inp54p), however, the inactivation by muscarinic stimulation was greater compared to that by Inp54p. The aim of this study was to investigate the complete inactivation mechanism of the heteromeric channels upon Gα(q)-phospholipase C β (Gα(q)-PLCβ) activation. We evaluated the activity of heteromeric channels with electrophysiological recording in HEK293 cells expressing TRPC channels. TRPC1/4 and TRPC1/5 heteromers undergo further inhibition in PLCβ activation and calcium/protein kinase C (PKC) signaling. Nevertheless, the key factors differ. For TRPC1/4, the inactivation process was facilitated by Ca²⁺ release from the endoplasmic reticulum, and for TRPC1/5, activation of PKC was concerned mostly. We conclude that the subsequent increase in cytoplasmic Ca²⁺ due to Ca²⁺ release from the endoplasmic reticulum and activation of PKC resulted in a second phase of channel inhibition following PI(4,5)P₂ depletion.

Expression of Rap1, guanosine triphosphate Rap1, vascular endothelial growth factor and β-catenin in experimental choroidal neovascularization / 中华眼底病杂志

Objective To observe the expression ofRapl,guanosine triphosphate-Rapl (GTP-Rapl),vascular endothelial growth factor (VEGF) and β-catenin in experimental choroidal neovascularization (CNV).Methods Forty-two brown Norwegian rats were randomly divided into a blank control group (7 rats) and a model group (35 rats).Both eyes were enrolled.The CNV model was established by holmium ion laser photocoagulation in the model group.At 3,7,14,21,and 28 days after photocoagulation,fluorescein fundus angiography (FFA) and choroidal vascular smear were performed to observe the degree of fluorescein leakage and CNV area in rats;Western blot and real-time quantitative polymerase chain reaction (RT-PCR) were used to detect the expression ofRap1,GTP-Rap1,VEGF,β-catenin and mRNA in CNV.Results The results of FFA examination showed that a large disc-shaped fluorescein leaked in the photo-condensation spot 14 days after photocoagulation.Laser confocal microscopy showed that compared with 7 days after photocoagulation,CNV area increased at 14,21,28 days after photocoagulation,and the difference were statistically significant (t=3.725,5.532,3.605;P＜0.05).Western blot showed that there was no significant difference in the relative expression of Rap1 protein in CNV at different time points after photocoagulation between the two groups (P=0.156).Compared with the blank control group,the relative expression of GTP-Rap1 protein was significantlydecreased,the relative expression of VEGF and β-catenin protein were significantly increased in the model group (P=0.000).The results of RT-PCR showed that there was no significant difference in the relative expression of Rap 1 mRNA at different time points after photocoagulation between the two groups (P=0.645),but there were significant difference in the relative expression of β-catenin mRNA (P=0.000).At 7,14,21 and 28 days after photocoagulation,there were significant difference in the relative expression of GTP-Rap 1 and VEGF mRNA between the two groups (P=0.000).Conclusions The expression of GTP-Rap1 in experimental CNV is significantly lower than that in normal rats.

ω-3 polyunsaturated fatty acids inhibits RHO-ROCK1 signaling pathway in SGC7901 gastric cancer cells / 中国医师杂志

Objective This study was aimed to investigate the effects of ω-3 polyunstaurated fatty acids (ω-3 PUFAs) on the growth of gastric cancer cells in nude mice,and to find whether the Ros homolog gene Rho-associated coiled-coil containing protein kinase 1 (RHO-ROCK1) signaling pathway is involved.Methods 16 BALB/C nude mice were injected subcutaneously with SGC7901 gastric cancer cells to establish the tumor-bearing mouse model.The mice were randomized:control group (normal saline) and intervention group (ω-3 PUFAs).The mRNA expression of Ros homolog gene family,member A (RHOA),RHOC,and ROCK1 in tumor tissue were detected by quantitative polymerase chain reaction (qPCR).Immunofluorescence and Western blot were used to detect RHOA,RHOC,and ROCK1 protein expression.Results The volume and weight of the tumors in the ω-3 PUFAs group were slightly smaller than that in the control group (P ＞ 0.05).Compared to the control group,hematoxylin and eosin staining showed multifocal tumor necrosis in the ω-3 PUFAs group,while the tumors of the control group showed abundant blood supply.qPCR and Western blot showed that the mRNA and proteins expression of RHOA and ROCK1 in the ω-3 PUFAs group was significantly lower than those in the control group (P ＜ 0.05).The immunofluorescence redults also showed that the expression of these proteins in the ω-3 PUFAs group was slightly lower than that in the control group.Conclusions These results suggested that ω-3 PUFAs may affect the growth of gastric cancer in nude mice by affecting the expression of RHOA,RHOC and ROCK1,thus inhibiting the excessive proliferation of gastric cancer cells and leading to tumor necrosis.

Differences in expression of Ras1, Rac1 and Rho1 genes between yeast and hyphal phases of Trichosporon asahii / 中华皮肤科杂志

Objective To investigate differences in the expression of Ras 1,Rac1 and Rho1 genes between yeast and hyphal phases of Trichosporon asahii (T.asahii),and to explore their roles in the formation of hyphae.Methods The yeast phase and hyphal phase of T.asahii were cultured and served as yeast phase group and hyphal phase group respectively.Total RNA was extracted from the 2 groups,and real -time fluorescence-based quantitative PCR (RT-PCR) was performed to measure the mRNA expression of Ras1,Rac1 and Rho1.Results The hyphal formation rate was significantly lower in the yeast phase group than in the hyphal phase group (0.40％ ± 0.53％ vs.99.33％ ± 0.57％,t =13.93,P ＜ 0.05).When the mRNA expression of Ras1,Rac1 and Rho1 in the yeast phase group was all set as 1,that in the hyphal phase group was 25.17 ± 10.99,16.81 ± 7.80,42.61 ± 18.50,respectively,with significant differences between the two groups in the three parameters (t =3.81,3.51,3.90,respectively,all P ＜ 0.05).Conclusion Ras1,Rac1 and Rho1 genes may participate in the regulation of hyphal formation in T.asahii.

Research progress on the relationship between Rho GTPases and breast cancer / 天津医药

Breast cancer is one of the major causes of death in women,and its incidence has been increasing year after year.The Rho GTPases,their regulatory proteins and Rho GTPases play an important role in promoting the occurrence and distant metastasis of breast cancer.Here we summarized the current knowledge of the regulation network of Rho GTPases,their regulatory proteins and Rho GTPases on the occurrence and development of breast cancer,and targeted therapy for RHO GTP enzyme pathway in breast cancer.

Research progress of Rab10 in tumor / 国际肿瘤学杂志

As a member of GTPase Rab family,Rab10 protein is not only involved in vesicle formation,transport,anchoring and fusion process,but also affects the occurrence and development of tumors.Research about the mechanisms of Rab10 in intracellular vesicle transport and tumor may provide a potential target and new idea for the anti-cancer therapy.

Differences in Rab protein expressions in McCoy cells with acute versus persistent Chlamydia trachomatis infection / 中华皮肤科杂志

Objective To investigate differences in Rab protein expressions in McCoy cells with acute versus persistent Chlamydia trachomatis (Ct) infection.Methods Cultured McCoy cells were infected with different amounts (400,500,550 μl/well) of Ct strain D suspensions,then cultured with the medium containing 100 U/ml penicillin G (persistent Ct infection groups) or that without penicillin G (acute Ct infection groups).Ct-uninfected McCoy cells receiving no penicillin G treatment served as the blank control group,and those receiving penicillin G treatment as the penicillin group.Mter 48-hour culture,McCoy cells were lysed,proteins were collected,and total RNA was extracted from the cells.Enzyme-linked immunosorbent assay (ELISA) was conducted to measure protein levels of Rab4A,Rab6A,Rab10,Rab11A and Rab14,and fluorescence-based quantitative PCR to quantify mRNA expressions of Rab4A and Rab14 (expressed as 2-ΔΔα).Results Protein levels of Rab4A,Rab6A,Rab10,Rab11A and Rab14 were all significantly lower in the acute than in the persistent Ct infection groups (all Z =3.621,P ＜ 0.001),and lower in the persistent and acute Ct infection groups than in the blank control group (all P ＜ 0.008 3),but insignificantly different between the blank control group and penicillin group (all P ＞ 0.05).In addition,the expressions of Rab4A and Rab14 mRNAs were consistent with those of their proteins in these groups.Conclusion The transcriptional and expression levels of Rab proteins are higher in McCoy cells persistently infected with Ct than in those acutely infected with Ct.

Effect of Rab11 gene expression on the invasion and migration of cervical cancer cell line SiHa in hypoxia / 中华妇产科杂志

Objective To explore the expression of Ras-related protein 11(Rab11)in hypoxia, the effect of Rab11 on the invasion and migration of cervical cancer cell line SiHa and its possible mechanism. Methods SiHa cells were divided into 4 groups, the normoxic blank group (normal culture in normoxia), the hypoxic blank group (normal culture in hypoxia), the negative control group [transfection of negative control small interfering RNA(siRNA)in hypoxia], the Rab11-siRNA group (transfection of Rab11 siRNA in hypoxia). Western blot was used to examine the expression of Rab11, integrin α5, integrin β3, phosphorylated focal adhesion kinase(p-FAK), phosphorylated phosphatidylinositol 3 kinase(p-PI3K) protein, together with the expression of Ras correlative C3 creotoxin substrate 1(Rac1), which was critical in regulating cell invasion. The mRNA expression of Rab11 in the 4 groups was detected by realtime-qPCR. The cell invasion was detected by matrigel assay, while the cell migration was detected by transwell assay. Immunofluorescence was used to identify intracellular location of Rac1 in SiHa cell. Results (1) The expression of Rab11, intergrin α5, intergrin β3, p-FAK, p-PI3K and Rac1 in the normoxic blank group were 0.56±0.04, 0.33±0.03, 0.32±0.03, 0.36±0.03, 0.35±0.03 and 0.47±0.03, respectively. In the hypoxic blank group, they were 0.73±0.03, 0.74±0.03, 0.61±0.03, 0.62±0.03, 0.60±0.03 and 0.73±0.03, respectively. In the negative control group, their expressions were 0.72±0.03, 0.73±0.03, 0.59±0.03, 0.61±0.03, 0.59±0.03 and 0.72±0.03, respectively. While in the Rab11-siRNA group, they were 0.44±0.03, 0.30±0.03, 0.29±0.03, 0.30±0.03, 0.30±0.03 and 0.34±0.04, respectively. The expressions of Rab11, α5, β3, p-FAK, p-PI3K and Rac1 were significantly higher in the hypoxic blank group than in the normoxic blank group(P<0.05), and were significantly lower in the Rab11-siRNA group than in the hypoxic blank group and the negative control group(P<0.05). (2) The expressions of Rab11-mRNA were 1.000±0.000, 1.454±0.114, 1.442±0.101, 0.570± 0.046 in the normoxic blank group, the hypoxic blank group, the negative control group and the Rab11- siRNA group, respectively. It was significantly higher in the hypoxic blank group than in the normoxic blank group(P<0.05), and was significantly lower in the Rab11-siRNA group than in the hypoxic blank group and the negative control group(P<0.05). (3) By Matrigel, the invasion cell number in the normoxic blank group, the hypoxic blank group,the negative control group and the Rab11-siRNA group were 65±12, 106±16, 104± 17 and 50±11, respectively. The invasion capacity was significantly higher in the hypoxic blank group than in the normoxic blank group(P<0.05), and was significantly lower in the Rab11- siRNA group than in the hypoxic blank group and the negative control group(P<0.05). (4) By transwell assay, the migration cells in the normoxic blank group, the hypoxic blank group, the negative control group and the Rab11-siRNA group were 127±12, 169±15, 161±13 and 77±13, respectively. The capacity of invasion was significantly higher in the hypoxic blank group than in the normoxic blank group(P<0.05), and was significantly lower in the Rab11- siRNA group than in the hypoxic blank group and the negative control group(P<0.05). (5) The immunofluorescence showed that the red fluorescence intensity around nucleus was significantly increased in the normoxic blank group, the hypoxic blank group and the negative control group than in the Rab11- siRNA group. Conclusions Hypoxia could promote the invasion and migration of SiHa cells. In hypoxia, the down regulation of Rab11 expression could inhibit the invasion and migration of SiHa cells. This might be due to the decreased expression of the intergrin α5, intergrin β3, p-FAK, p-PI3K and Rac1 protein.

G-protein Coupled Estrogen Receptor (GPER/GPR30) and Women's Health

Estrogen - the female sexual hormone playing the most important role - plays a physiologically significant role, not only regulating in cell signals with second messenger but also being active in regulating transcription. Estrogen receptor (ER) which is a protein accepting estrogen not only play the role of a transcription factor combining with other genes to regulate their activity like other nuclear receptors but also performs external activities, combining with DNA, etc. G-protein coupled ER (GPER) that has been recently discovered exists as 7-membrane and has non-genomic (rapid) signaling. These functions, however, are not extensively addressed. This paper discusses the roles of GPER and its physiological mechanism.

Estudo da degradação da proteína Tau hiperfosforilada por vias independentes do proteassoma, em modelo experimental de neurodegeneração / Study of hyperphosphorylated Tau protein degradation by proteasome-independent pathways, in an experimental model of neurodegeneration

O desenvolvimento das doenças neurodegenerativas, como a doença de Alzheimer, está associado à presença de agregados proteicos contendo Tau hiperfosforilada (p-Tau). Esta disfunção da Tau leva a prejuízos na homeostase celular. Um mecanismo chave para diminuir e/ou prevenir os danos promovidos pelos agregados contendo Tau seria o estímulo de sua degradação. Neste sentido, a proposta do presente estudo foi analisar a degradação da proteína Tau após aumento da expressão exógena da cochaperona Bag-2, a qual influencia o sistema proteassomal de degradação; bem como avaliar a ativação dos sistemas de degradação, a fim de correlacionar estes sistemas em cultura de células primárias e organotípica do hipocampo de ratos. Os resultados mostraram que a rotenona foi capaz de aumentar os níveis de p-Tau e que a superexpressão de Bag-2, foi eficiente em prevenir e degradar a p-Tau. O mecanismo envolvido neste processo envolve a coordenação dos sistemas proteassomal e lisossomal, já que a Rab7 e a Rab24 (envolvidas na via lisossomal) mostraram-se diminuídas na fase que antecede a agregação proteica, enquanto houve aumento da Rab24 na presença dos agregados proteicos. Com relação ao peptídeo beta amiloide, foi demonstrado tendência de aumento de p-Tau acompanhado de diminuição da atividade proteassomal e lisossomal. O tratamento com PADK (ativador lisossomal) foi capaz de reverter este efeito nestas diferentes condições. A análise da interrelação entre os sistemas mostrou que uma inibição do proteassoma favorece a via lisossomal e que o inverso não se repete. Os resultados sugerem que a modulação das vias de degradação pode ser interessante para o estudo, prevenção e tratamento das doenças neurodegenerativas associadas à agregação de proteínas...

Neurodegenerative diseases, such as Alzheimer's, are associated to protein inclusions containing hyperphosphorylated Tau (p-Tau). It is well established that Tau dysfunction impairs cell homeostasis. A key mechanism to prevent and/or reduce the damage promoted by aggregates of Tau might be its degradation. In view of this, the aims of the present study are to evaluate p- Tau clearance following exogenous expression of Bag-2, which stimulates proteasome; as well as to analyze the activation of both lysosome and proteasome pathways in order to understand the crosstalk between these two systems in primary and organotypic cultures of rat hippocampus. Results showed that rotenone was able of increasing p-Tau that was prevented and degraded by Bag-2 overexpression. Mechanisms involved in this process involve the coordination of cell degradation systems, depending upon aggregation status, since Rab7 and Rab24 (involved in lysosomal pathway) were decreased before protein aggregation, while Rab24 increased in the presence of protein inclusions. Amyloid-beta peptide also increased p-Tau accompanied by decreased proteasome and lysosome activity. PADK (lysosomal activator) treatment reverted the inhibition promoted by amyloidbeta peptide. Inhibition of proteasome leads to activation of lysosome, but lysosome inhibition does not affect proteasome. Overall, results suggest that targeting degradation pathways might be useful to understand, prevent and treat neurodegenerative diseases associated with protein deposits...

Effects of butylphthalide on brain edema, blood-brain barrier permeability and RhoA expression in cortex in focal cerebral infarction in rats / 国际脑血管病杂志

Objective To investigate the effects of butylphthalide on brain edema,blood-brain barrier permeability and RhoA expression in cortex in focal cerebral infarction in rats.Methods A total of 220 male Sprague Dawley rats were divided into a control,a model and a butylphthalile group (40 mg/kg,once a day,gavage) according to the random number table method.A model of rat focal cerebral infarction was induced by photochemical method.At 3,12,24,72,and 144 h after modeling,wet-dry weight method and Evans blue extravasation method were used to detect the brain water content and blood-brain barrier permeability.At 24 h after modeling,immunohistochemical staining and Western blot were used to detect the expression of RhoA protein in the periinfarction cortex.Results Compared to the control group,the brain water content (except at 6 h) and blood-brain barrier permeability in the model group and the butylphthalide group were increased significantly (all P ＜ 0.05).The immunohistochemical staining and Western blot suggested that the RhoA expression in the periinfarction cortex was upregulated significantly (all P ＜ 0.05).Compared to the model group,the brain water content and blood-brain barrier permeability at different time points in the butylphthalide group were decreased significantly (all P ＜ 0.05).The expression levels of RhoA were also decreased significantly (P ＜ 0.05).Conclusions Butylphthalide may reduce the brain edema of focal cerebral infarction in rats,inhibit disruption of the blood-brain barrier,and down-regulate the expression of RhoA.

Association between polymorphism of the G-protein β3 subunit C825T and essential hypertension: an updated meta-analysis involving 36,802 subjects

Purpose: The G-protein β3-subunit gene C825T polymorphism (GNB3-C825T) has been reported to be associated with essential hypertension (EH), but results from previous studies are conflicting. The present study aimed at investigating the association between this polymorphism and risk of EH using a meta-analysis on the published studies. Materials and Methods: PubMed, Embase, CBM (China Biological Medicine Database), Wanfang and VIP databases were searched to identify eligible studies published in English and Chinese before March 2013. Data were extracted using standardized methods. The association was assessed by the odds ratio (OR) with 95% confidence intervals (CI). Begg's test was used to measure publication bias. Results: A total of 40 case-control studies containing 16,518 EH patients and 20,284 controls were involved in this meta-analysis. Overall, a significant association was found between GNB3 C825T polymorphism and risk of EH when all studies were pooled with a random-effects model for T versus C (OR=1.09, 95% CI: 1.04-1.19). In the subgroup analysis, the same association was found in overall Caucasian (T versus C, OR=1.16, 95% CI 1.08-1.24) and Chinese populations (TT versus CC, OR=1.23, 95% CI 1.06-1.57). No associations were detected between GNB3-C825T and the risk of EH overall in Asian and Japanese people. Conclusions: Meta-analysis results suggest that the GNB3-C825T polymorphism is associated with risk of EH in the overall population, the Caucasians and the Chinese. The effect of the variants on the expression levels and the possible functional role of the variants in EH should be addressed in further studies.

Relationship between 5-hydroxytryptamine 1A receptor and G-protein β3 subunit polymorphisms and post-stroke depression / 中华神经科杂志

Objective To assess whether 5-HTR1A C( - 1019) G and GNβ3 C825T gene polymorphisms are associated with post-stroke depression (PSD) and explore the genetic mechanism of the pathogenesis of post-stroke depression. Methods All 159 patients with first stroke were divided into the PSD group and the control group according to HAMD scores. Their genotypes were determined with polymerase chain reaction and allele-specific restriction enzyme analysis. Results The frequency of 5-HTR1A (-1019) GG genotype(8/53,15. 1% ), G allele (44/106,41.5%)and GNβ3 825T allele(68/106,64. 2% ) were significantly higher in the post-stroke depression group than in the controls (5/106,4.7% ;35/212, 16. 5%; 113/212, 53.3%; ×2 = 23.204, 23. 655, 3. 392, all P ＜ 0. 05 ). Combined genotype analysis showed that individuals with both 5-HTR1A ( - 1019) G and GNβ3 825T allele ( OR =4. 980,95% CI 2. 429-10. 210,P =0. 000) had a higher risk than those with 5-HTR1 A (-1019) G allele ( OR = 3. 589,95% CI 2. 113-6. 096, P = 0. 000) or GNβ3 825T allele ( OR = 0. 638,95% CI 0.395-1. 031 ,P =0. 042) only for post-stroke depression. Conclusion The 5-HTR1A C( - 1019)G and GNβ3 C825T polymorphisms are predisposing genes of post-stroke depression. Our data also suggest a significant interaction between the 5-HTR1A ( - 1019)G allele and GNβ3 825T allele in post-stroke depression.

C825T polymorphism of G protein β3 subunit in cerebral infarction patients with a history of hypertension / 国际脑血管病杂志

Objective To investigate the relationship between the C825T polymorphism of G protein β3 subunit (GNB3) and essential hypertension and cerebral infarction patients with a history of hypertension. Methods The C825T polymorphism of GNB3 was determined by polymerase chain reaction-restriction fragment length polymorphism in 110 healthy subjects aged over 40 years, 92 patients with essential hypertension, and 80 cerebral infarction patients with a history of hypertension. Sex, age, family histories of diabetics, smoking and alcoholic consumption were documented, and body mass index, waist-hip ratio, total cholesterol (TC),triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and fasting blood glucose concentration were measured. A multivariate logistic regression analysis was used to screen the factors associated with the occurrence of cerebral infarction in patients with hypertension.Results The distribution of the C825T polymorphism of GNB3 in the 3 groups all met the Hardy-Weinberg Law of genetic equilibrium. The genotype frequencies of CC, CT and TT in cerebral infarction patients with a history of hypertension were 33％, 57％, and 20％, respectively; those in patients with essential hypertension were 33％, 42％, and 25％ ; respectively;and those in the control group were 26％, 54％, and 20％, respectively. There were no significant differences (x2 =4. 030, P =0. 402). The allele frequencies of 825T in the 3 groups were 39％, 40％, and 47％, respectively. There were no significant differences (x2 =0. 832). A multivariate logistic regression analysis showed that TC (odds ratio [ OR] 10. 810, 95％ confidence interval [ CI] 2. 64544. 136, P =0. 000), TG (OR 5. 453, 95％ CI 1.662-17. 881, P =0. 005),HDL-C (OR, 0. 181, 95％ CI 0. 041-0. 795, P = 0. 027), blood glucose (OR 2. 386, 95％ CI1.062-5. 363, P =0. 035), and diabetes (OR 7. 156, 95％ CI 1.271-40. 291, P =0. 026) were the independent risk factors for cerebral infarction, and the GNB3 genotype and allele did not enter the model. Conclusions The C825T polymorphism of GNB3 may not be associated with cerebral infarction and essential hypertension.

Alteraciones en el reclutamiento y activación de proteínas Rab durante la infección micobacteriana: [revisão] / Alterations in recruitment and activation of Rab proteins during mycobacterial infection: [review]

En el fagosoma, Mycobacterium spp. altera la activación y reclutamiento de diferentes proteínas “del gen Ras de cerebro de rata”, comúnmente conocidas como Rab. En este manuscrito se revisa una serie de reportes que han demostrado que los fagosomas que contienen micobacterias tienen una expresión mayor y sostenida de Rab5, Rab11, Rab14 y Rab22a, y menor o ninguna expresión de Rab7, Rab9 y Rab6. Esto se correlaciona con aumento de la fusión de estos fagosomas con endosomas tempranos y de reciclaje, lo que les permite mantener ciertas características de compartimentos tempranos, permite que las bacterias obtengan acceso a nutrientes y previene la activación de mecanismos contra la micobacteria. La expresión de mutantes constitutivamente activos de las Rab de endosomas tempranos impide la maduración de fagosomas que contienen esferas de látex o micobacterias inactivadas por calor. Mientras que su silenciamiento, mediante ARN de interferencia o mediante dominantes negativos, induce la maduración de fagosomas micobacterianos. Los mecanismos exactos por los que las micobacterias alteran la dinámica de expresión de estas GTPasas, afectando la maduración fagolisosómica, no se han establecido. El problema podría explicarse por defectos en el reclutamiento de las proteínas que interactúan con Rab, como la cinasa-3 del fosfatidilinositol y el antígeno endosómico temprano 1. La identificación de los mecanismos empleados por Mycobacterium spp. para interrumpir el ciclo de activación de las Rab, será esencial para comprender la fisiopatología de la infección micobacteriana y útil como posibles blancos farmacológicos.

At the phagosome level, Mycobacterium spp. alters activation and recruitment of several “Ras gene from rat brain” proteins, commonly known as Rab. Mycobacterial phagosomes have a greater and sustained expression of Rab5, Rab11, Rab14 and Rab22a, and lowered or no expression of Rab7, Rab9 and Rab6. This correlates with increased fusion of the phagosomes with early and recycling endosomes acquiring some features of early phogosomes, allowing the bacteria to gain access to nutrients and preventing the activation of anti-mycobacterial mechanisms. The expression of constitutively active mutants of Rab from the early stage endosomes prevents the maturation of phagosomes containing latex beads or heat-inactivated mycobacteria. Silencing of these mutants by interference RNA or dominant negative forms induces the maturation of mycobacterial phagosomes. The mechanisms have not been established by which mycobacteria alter the expression of these GTPases and thereby shift the phagolysosomal maturation. The problem can be explained by alterations in the recruitment of proteins that interact with Rab, such as phosphoinositide 3-kinases and early endosomal antigen 1. Identifying the mechanisms used by Mycobacterium spp. to disrupt the cycle of Rab activation will be essential to understand the pathophysiology of mycobacterial infections and usefully to potential drug targets.

Expression and clinical implications of RADIL gene in pancreatic cancer / 中华胰腺病杂志

Objective To investigate the RADIL mRNA expression in pancreatic carcinoma and to evaluate its clinical significance.Methods Fluoesecent quantitative PCR (FQ-PCR) was used to detect the RADIL mRNA expression in 40 patients with pancreatic carcinoma and adjacent tissue and in 5 healthy adult with normal pancreatic tissue and to observe its relationship with clinicopathologic parameters.Results RADIL mRNA was expressed in pancreatic carcinoma and adjacent tissue, as well as normal pancreatic tissue, and the relative expression was 2.263 ± 3.826, 5.425 ± 8.858 and 8.559 ± 4.214, respectively.There was statistically significant difference among the three groups (P ＜0.05 ).RADIL mRNA expression was closely related with the metastasis and differentiation grade ( r = -0.312 and -0.294, P ＜ 0.05 ), however, it was not significantly related to tumor site, tumor size, CA19-9, TNM staging, sex and age.Conclusions RADIL gene may have an inhibitory effect on the pancreatic cancer.

A pilot study of protein fingerprinting in brain-gut interaction model of irritable bowel syndrome / 中华内科杂志

Objective Matrix-assisted laser desorption ionization-time of might-mass spectrometry (MALDI-TOF-MS) was utilized to analyze the protein fingerprint in brain-gut interaction of irritable bowel syndrome (IBS) model rats' colon, so as to find the clues for IBS. Methods Fourteen healthy male adult Wistar rats were selected and divided into a control and a chronic and acute stress ( CAS) group. Colon motility, visceral sensation and behavior changes of rats were detected to evaluate the model. MALDI-TOF-MS was used to observe the overall view of protein in colon so as to study whether there are abnormalities of protein levels in IBS. Results As compared with those in the control group, the number of fecal pellets [ (6. 00 ± 1. 69 ) pellets/1 h vs ( 1. 14 ± 0. 69 ) pellets/1 h, P < 0. 01 ] and frequency of abdominal contraction induced by colorectal distention (CRD) increased, while the amount of weight gain [ (298. 88 ± 18.61)gvs (348. 00±12. 44)g, P<0.01] and consumption of sucrose solutions [ (13. 63 ± 1. 69) ml/1 h vs (19.00±3.06) ml/1 h, P<0.05] decreased in the CAS group (P <0. 05). As far as protein/peptide quality different peak was concerned, CAS rats had 12 different peaks compared with the control rats. The different proteins could be divided into 4 types, which were related to iron secretion, protein synthesis, G protein system and immunity. The protein levels of the model group were higher than those in the control group (P < 0. 05). Conclusions The CAS rats integrate the major characteristics of IBS such as altered colon motility, higher visceral hypersensitivity and psychiatric disorder and can mimic the brain-gut interaction of IBS partly. The detection of differential proteins provides reference for the pathogenesis and treatment of IBS.

Membrane Trafficking of Collecting Duct Water Channel Protein AQP2 Regulated by Akt/AS160

Akt (protein kinase B (PKB)) is a serine/threonine kinase that acts in the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. The PI3K/Akt signaling pathway, triggered by growth factors and hormones including vasopressin, is an important pathway that is widely involved in cellular mechanisms regulating transcription, translation, cell growth and death, cell proliferation, migration, and cell cycles. In particular, Akt and Akt substrate protein of 160 kDa (AS160) are likely to participate in the trafficking of aquaporin-2 (AQP2) in the kidney collecting duct. In this study, we demonstrated that 1) small interfering RNA (siRNA)-mediated gene silencing of Akt1 significantly decreased Akt1 and phospho-AS160 protein expression; and 2) confocal laser scanning microscopy of AQP2 in mouse cortical collecting duct cells (M-1 cells) revealed AS160 knockdown by siRNA increased AQP2 expression in the plasma membrane compared with controls, despite the absence of dDAVP stimulation. Thus, the results suggest that PI3K/Akt pathways could play a role in AQP2 trafficking via the AS160 protein.

The establishment of an animal model of gut-brain interaction in irritable bowel syndrome for the evaluation of visceral sensation, motility and psychological behavior / 中华内科杂志

Objective To develop a gut-brain interaction animal model of IBS which combines multiple factors including behavior, visceral sensation and motility. Methods Setting up a multifactor interactional animal model (chronic acute combining stress model, CACS) based on a chronic unpredictable mild stress model of depression (CUMS) while combined with wrap restraint stress (WRS) , changes of some indexes were recorded including motility (granules of defecating, time of defecating), visceral sensitivity ( spontaneous contraction of abdominal striated muscles ) and behavior/mind ( sucrose consumption, body weight). G protein subunits were measured by Western blot in both hippocampus and prefrontal cortex simultaneously. Results ( 1 ) Compared with the state before stress given, defecating granules increased, defecating time of glassie from rectum shorten, number of abdominal contraction increased, and sucrose consumption decreased in CACS, however, neither significant change was found on defecating behavior in CUMS nor on sucrose consumption in WRS; (2) Compared with the control group, some G protein submits expression decreased in both CACS and CUMS( P < 0. 05 ) , while no significant changes of any G protein subunits were found in WRS. Conclusion The CACS animal model was a new, brain-gut interaction model, which can mimic part of human symptoms of IBS very well.