Effect of protein kinase C signal pathway on resistin expression in 3T3-L1 adipocytes

AIM：To investigate the effect of protein kinase C on resistin expression in 3T3-L1 adipocytes.METHODS：The differentiated 3T3-L1 adipocytes were incubated with 50 nmol/L phorbol 12-myristate 13-acetate (PMA) or 5 μmol/L Ro-31-8220 for 24 h.Expression of resistin mRNA was detected by RT-PCR and expression of resistin protein was detected by Western blotting.RESULTS：Compared with control,PMA increased the expression of resistin mRNA and protein in 3T3-L1 adipocytes significantly (P<0.01),while Ro-31-8220 decreased the expression of resistin mRNA and protein in 3T3-L1 adipocytes obviously (P<0.01).CONCLUSION：Protein kinase C signal pathway may regulate resistin expression in 3T3-L1 adipocytes.     

Correlation among plasma leptin,resistin an type 2 diabetes mellitus

AIM：To assess the association of resistin,obesity,serum lipid levels and insulin resistance with plasma leptin.METHODS：The concentrations of fasting serum glucose,insulin,lipid profiles,plasma resistin and leptin were assayed in 80 cases (including 37 controls with normal glucose tolerance and 43 patients with type 2 diabetes mellitus).RESULTS：Fasting plasma leptin level was positively correlated with sex,body mass index (BMI),waist circumference (WC),waist-hip ratio and fasting serum insulin (F Ins) （P<0.01）.Fasting plasma leptin level was negatively correlated with insulin sensitivity index (r=-0.373,P<0.01).There was no correlation between the concentrations of plasma leptin and FPG,TG,TC and resistin （P>0.05）.CONCLUSION：Fasting plasma leptin level is positively correlated with obesity and insulin resistance,not resistin.Leptin may play a role in the pathogenesis of type 2 diabetes mellitus.     

Effects of Shan He Jian Fei Granule on the expression of leptin,adiponectin and resistin in obese rats induced by high-fat feeding

AIM: To study the effects of Shan He Jian Fei Granule (SHJFG), a Chinese medicine, on weight-reduction and fat-decrease in adiposity rats, and to observe the changes of leptin, adiponectin and resistin. METHODS: After the models were prepared successfully, the rats were randomly divided into four groups: normal group, low dosage, middle dosage, high dosage and obesity control group. After 8 weeks interference with SHJFG, the weight and the naso-anal length of each rat was measured and Lees index were calculated. The levels of TG, TC, LDL, HDL and leptin in serum were carefully determined. The gene expressions of adiponectin and resistin in adipose tissues of rats were determined by RT-PCR. RESULTS: Compared to high-fat diet group, the body weights, the Lees indexes, the weight of fat tissues and levels of TG, TC, LDL and leptin in SHJFG groups significantly decreased (P<0.05). Adiponectin mRNA expression in SHJFG group significantly increased (P<0.05), and the resistin mRNA expression also significantly increased. CONCLUSION: SHJFG significantly decreases the body weight and the serum levels of TG, TC and LDL in obese rats. The effects of SHJFG in raising the mRNA expressions of adiponectin and resistin in fat tissues may be one of the main role that results in lowering body weight in obese rats.     

“2006中国蔬菜产业可持续发展研讨会”在武汉召开

由中国园艺学会主办，湖北省园艺学会、国家蔬菜改良中心华中分中心、华中农业大学园艺林学学院共同承办的“2006中国蔬菜产业可持续发展研讨会”于2006年4月13-15日在湖北武汉华中农业大学举行，来自全国17个省（市）和自治区47个单位的近120名代表出席这次全国性会议。会议开幕式由中国园艺学会蔬菜专业委员会主任、中国农业科学院蔬菜花卉研究所副所长孙日飞研究员主持。华中农业大学副校长李名家教授、武汉市张学忙副市长、科技部农村司魏勤芳处长、农业部科技司刘艳处长、武汉市科协黄和平主席和中国园艺学会理事长方智远院士先后致辞。     

Effect of rosiglitazone on serum resistin and glomerular sclerosis in type 2 diabetic rats

AIM: To observe the effect of rosiglitazone on serum resistin level and to investigate the possible mechanism of glomerular sclerosis in type 2 diabetic rats. METHODS: Ten-week-old Wistar rats were divided into diabetic nephropathy (DN) group (10 cases) and DN+rosiglitazone group (10 cases). The other 10 Wistar rats were used as normal control group. Type 2 diabetic rats were induced by cutting the right kidney and injecting small dose (35 mg/kg) of streptozocin (STZ). Rosiglitazone group received rosiglitazone 10 mg·kg-1·d-1 while normal control group and DN group were fed with normal chow diet. After 20 weeks, vessel blood was collected for plasma IL-1, TNF-α and resistin assayed by ELISA. The serum levels of glucose, creatinine, urea nitrogen and microalbum of 24 h urine were also detected. The expression of TGF-β1 in glomerulus was examined by immunohistochemistry. Smad2 phosphatase activity was detected by Western blotting. RESULTS: The plasma IL-1, TNF-α, hs-CRP and resistin, and microalbum of 24 h urine in rosiglitazone group, were significantly lower than those in DN group while the serum level of glucose was not different from that in DN group. The expression of TGF-β1 and phosphorylated level of Smad2 were lower in rosiglitazone group than those in DN group. The degree of glomerular sclerosis in rosiglitazone group was obviously lighter than that in DN group. CONCLUSION: Rosiglitazone delays and ameliorates the development of diabetic glomerular sclerosis. The mechanism is possibly related to the modulation of resistin and other inflammatory factors. Anti-inflammation is a potential way for controlling diabetic nephropathy.     

Role of resistin in hepatic insulin resistance and the underlying mechanism

AIM: To investigate the role of resistin in hepatic insulin resistance and its mechanism. METHODS: A mouse model of hyperresistinemia in C57BL/6 mice was established by intravenous administration of the recombinant adenovirus encoding mouse resistin. Using periodic acid-Schiff staining we observed the effects of resistin on hepatic glycogen storage. Western blotting was used to measure AMPK-α protein and phosphrylated AMPK-α (Thr172) protein. mRNA levels of phosphoenolpyruvate carboxykinase gene and glucose-6-phosphatase gene were measured by real-time PCR. RESULTS: On day 5 after Adv injection, the concentration of plasma resistin was much higher in Adv-resistin-EGFP-treated mice than that in saline- or Adv-EGFP-treated mice. Semiquantitation of hepatic glucogen storage by PAS showed that the mice with hyperresistinemia had decreased glycogen particles compared to normal control and Adv-EGFP groups. The ratio of phosphorylated AMPK (Thr172)-α to total AMPK-α was used to evaluate hepatic AMPK activation. Compared with normal control and Adv-EGFP groups, the Adv-resistin-EGFP-treated mice had significantly lower ratio of p-AMPK/AMPK, and higher expression levels of G6Pase and PEPCK mRNA in liver. CONCLUSION: Resistin may decrease AMPK activation with downregulating expression of gluconeogenic enzymes, resulting in increased glucose production and decreased hepatic glycogen storage. Resistin may play an important role in hepatic insulin resistance.     

Effects of recombinant adenovirus-mediated chronic hyperresistinemia on glucose metabolism in mice

AIM: To establish the animal model of hyperresistinemia and to observe the effects of resistin on glucose metabolism and insulin sensitivity in vivo. METHODS: We established a mouse model of hyperresistinemia in C57BL/6 mice by intravenous administration of the recombinant adenovirus encoding mouse resistin. Then we observed the fasting blood glucose and insulin levels. We also investigated glucose tolerance by IPGTT, and insulin sensitivity by IPITT. RESULTS: On 5 d after the injection, the concentration of plasma resistin was more than 15-fold higher in Adv-resistin-EGFP-treated mice than that in saline- or Adv-EGFP-treated mice. In the fasting state, no difference in glucose levels was observed among three groups. However, mice injected with Adv-resistin showed higher insulin levels, impaired glucose tolerance and insulin sensitivity. CONCLUSION: Hyperresistinemia affects glucose metabolism in mice and it may play an important role in the pathogenesis of insulin resistance and type 2 diabetes.     

Progress in resistin and type 2 diabetes as well as obesity

Resistin, a new hormone found in the year 2001 and secreted by adipocytes, is related to type 2 diabetes and obesity. It brings some hope to solve the medical hamper of insulin resistance. The resistin discovery, molecule structure, function and expression, secretion regulation as well as gene polymorphism are reviewed in the article.     

Mechanisms of hyperglycemia induced by immunosuppressant FK506

AIM：To investigate the effect of immunosuppressant FK506 on serum glucose in rats and to explore its mechanism. METHODS：Sprague-Dawley rats (n=12) were randomly divided into drug group and normal group. The rats in drug group were intraperitoneally injected with FK506 at dose of 1 mg·kg-1·d-1 and the rats in normal group received saline (1 mL·kg-1·d-1, ip) for 14 d. The fasting weight and fasting glucose were regularly measured every 2 d. Visceral fat was isolated from the rats at the end of experiment. The mRNA expression of adiponectin, leptin, visfatin, resistin, retinol-binding protein 4 (RBP4) and peroxisome proliferator-activated receptors γ (PPAR-γ) was determined by real-time fluorescence quantitative PCR. The protein expression of PPAR-γ and adiponectin was measured by Western blotting. RESULTS：Compared with normal group, the concentration of fasting blood glucose in model group was significantly increased from the 10th day (P<0.05). At day 14, the fasting blood glucose of the model group increased from (5.10±062) mmol/L to (7.73 ± 0.73) mmol/L. No significant change of blood glucose in normal group between the 10th day and the 14th day ［from (4.66 ± 0.32) mmol/L to (5.80±0.10) mmol/L］ was observed. Compared with normal group, the mRNA expression of PPAR-γ, adiponectin and leptin in the adipose tissue of model group was significantly decreased (P<001), whereas the expression of visfatin, resistin and RBP4 was significantly increased (P<005). Compared with normal group, the expression of PPAR-γ and adiponectin in model group was decreased (P<001). CONCLUSION：FK506 may decrease the expression of PPAR-γ to change the expression of adipocytokines and induce hyperglycemia in rats.     

Interaction of polymorphisms in resistin gene promoter -420C/G,cytochromes P4501A1 gene MspI and cigarette smoking on nonalcoholic fatty liver disease

AIM: To investigate the interaction of polymorphisms of resistin gene promoter -420C/G, cytochromes P4501A1-MspI and cigarette smoking in nonalcoholic fatty liver disease (NAFLD). METHODS: The genetic polymorphisms in resistin gene promoter -420C/G and CYP1A1-MspI were analyzed by the technique of polymerase chain reaction (PCR) in peripheral blood leukocytes of 900 NAFLD cases and 900 healthy persons. RESULTS: The frequencies of -420C/G (GG) and CYP1A1-MspI (m2/m2) were 49.75% and 50.08% in NAFLD cases and 24.00% and 24.25% in healthy controls, respectively. Statistical tests showed a significant difference in the frequencies between the 2 groups (P<0.01). The risk of NAFLD with -420C/G (GG) was significantly higher than that of controls. Individuals who carried with CYP1A1-MspI (m2/m2) had a high risk of NAFLD. Combined analysis of the polymorphisms showed that the percentages of -420C/G (GG)/CYP1A1-MspI (m2/m2) in NAFLD and control groups were 39.83% and 12.83%, respectively (P<0.01). The people who carried with -420C/G (GG)/CYP1A1-MspI(m2/m2) had a high risk in NAFLD group. The cigarette smoking rate in NAFLD group was signi-ficantly higher than that in control group (P<0.01), and the statistic analysis suggested an interaction between cigarette smoking and -420C/G (GG) and CYP1A1-MspI (m2/m2), which increased the risk of NAFLD.CONCLUSION: -420C/G (GG), CYP1A1-MspI (m2/m2) and cigarette smoking are the risk factors in NAFLD. The interactions between genetic polymorphisms in -420C/G, CYP1A1- MspI (m2/m2) and cigarette smoking increase the risk of NAFLD.     

Total triterpenoids from Psidium Guajava leaf improves insulin resistance in 3T3-L1 adipocytes

AIM: To investigate the effects of total triterpenoids from Psidium guajava leaf (TTPGL) on 3T3-L1 adipocyte insulin resistance (IR) and to explore the possible mechanism. METHODS: 3T3-L1 pre-adipocytes were cultured and induced to differentiate into 3T3-L1 adipocytes, then treated with TTPGL (0.3, 1, 3, 10 μg/L) for 48 h. The cells were divided into 0.1% DMSO group, positive drug sodium orthovanadate (Van, 10 μmol/L) group, model group and control group. The effect of TTPGL on the cell activity of pre-adipocytes was detected by MTT assay and its influence on the cellular differentiation was observed by oil red O staining. The IR model of the 3T3-L1 adipocytes was established successfully and then treated with different drugs for 48 h. The glucose consumption in the supernatant of IR adipocyte's culture medium was assayed by glucose oxidase-peroxidase (GOD-POD), free fatty acid (FFA) levels were measured by colorimetric method, and adipocytokines levels were assayed by ELISA. The mRNA expression of protein tyrosine phosphatase-1B (PTP1B) of IR adipocyte was detected by real-time PCR. The protein levels of phosphorylated insulin receptor substrate 1/insulin receptor substrate 1 (p-IRS-1/IRS-1) and phosphorylated protein kinase B/protein kinase B (p-Akt/Akt) were determined by Western blot. RESULTS: Compared with DMSO group, TTPGL treatment significantly promoted the cell activity of 3T3-L1 pre-adipocytes and inhibited its differentiation (P < 0.01). TTPGL (1~10 μg/L) improved glucose consumption of IR adipocytes significantly (P < 0.01), with or without insulin stimulation, and TTPGL (0.3~3 μg/L) restrained FFA production remarkably(P < 0.01). Compared with model group, TTPGL (0.3 and 3 μg/L) significantly increased the secretion of adiponectin in IR adipocytes (P < 0.05), and inhibited the secretion of tumor necrosis factor-α (TNF-α) (P < 0.01). TTPGL (3 μg/L) restrained the secretion of resistin significantly (P < 0.05), and showed no significant effect on secretion of leptin. It also down-regulated the mRNA expression of protein tyrosine phosphates 1B (PTP1B) in IR adipocytes significantly (P < 0.01), and increased the protein levels of p-IRS-1/IRS-1. TTPGL (0.3 and 3 μg/L) up-regulated the protein level of p-Akt/Akt in IR adipocytes significantly (P < 0.05).CONCLUSION: TTPGL reduces IR in 3T3-L1 adipocytes. The mechanism may be that TTPGL significantly down-regulated mRNA expression of PTP1B and increased the protein levels of p-IRS-1/IRS-1 and p-Akt/Akt in IR adipocytes.     

Landscape patterns simulation with a modified random clusters method

A new modified random clusters method for the simulation of landscape the matic spatial patterns is presented. It produces more realistic and general results than landscape models that have been commonly used to date in the field of landscape ecology. Simulated patterns are said to be realistic, apart from their patchy and irregular appearance, because the values of the spatial indices as a function of habitat abundance measured in real landscape patterns (number of patches, edge length and patch cohesion index) can be replicated with the proposed landscape model. It allows a wide range of spatial patterns to be obtained, in which fragmentation and habitat abundance can be systematically and independently varied. Furthermore, a degree of control over the irregularity of the shapes of the simulated landscapes can be achieved, and it is also possible to simulate patterns with anisotropy. The proposed method is easy to implement and requires little computation time, which enhances the practical possibilities of this method in different areas of landscape ecology.     

晚熟耐贮梨新品种-新苹梨选育

新苹梨是一优良实生品种,属白梨系统。优质、晚熟、耐贮、抗逆性强。平均单果重357 g,果形指数0.99,酥脆多汁,可溶性 固形物7.85%,总糖8.46％,总酸0.56％,酸甜味浓,果实发育期150d,属晚熟品种。果实常温下可贮至翌年5月份,贮后风味更佳; 抗寒性与苹果梨相似,对梨黑星病和黑斑病有较强抗性;结果习性与苹果梨相近。可在苹果梨种植区域栽培。     

西葫芦新品种——晋西葫芦1 号

 ‘晋西葫芦1 号’为早熟西葫芦一代杂种, 生育期约40 d; 嫩瓜长棒形, 纵长20~ 25 cm, 横径4~ 5 cm, 皮呈绿色, 粗细均匀, 商品性好, 籽少, 宜生调; 一般产量达97. 5~ 105 t/ hm², 比对照 早青一代! 增产18. 5 %; 生长势强, 抗病性好, 适宜保护地和露地地膜覆盖栽培。     

关于果桑品种选育的思考

为促进果桑品种选育研究,在多年进行果桑品种选育的基础上,结合他人已有的研究,分析与果桑品种选育密切相关的若干问题,提出了如下建议:以桑椹产量高、品质优及抗菌核病为果桑育种目标;以全国种植面积最大的果桑品种"粤椹大10"为对照品种;重视果桑资源的搜集和评价;在选育方法上,以常规育种为主,采用杂交技术和诱变技术相结合可提高选育效率;应把果桑作为一种果树来对待,并以专用型果桑品种的选育研究为重点,加快果桑新品种的育成,促进桑椹产业的发展。     

蔬菜容器育苗技术探讨

采用容器育苗具有很好的护根作用。在生产上育黄瓜、番茄苗用直径８￣１０ｃｍ，育辣椒、茄子苗用直径７￣８ｃｍ的容器为宜。容器高度以１０￣１３ｃｍ为宜。容器材质塑料比纸的好。我国生产的育苗钵钵底应改进。用高质量的营养土或营养液育苗可以适当缩小容器直径。改进摆放方法，单位面积内能多育１５．５％秧苗。育苗后期只调整地上营养面积可以显著地提高秧苗质量。     

Progress in Src protein

Src is a non-receptor protein tyrosine kinase activated by a number of extracellular signal moleculars.It is recruited to peripheral sites through myristoylation and the SH3 domain.Src initiates intracel-lular signal trandsduction pathways that influence cell adhesion, migration, growth, differentiation and survival though catalytic domain.Src is normally maintained in an inactive conformation because of carboxy terminal Src kinase, but can be activated transiently during cellular events such as mitosis or constitutively by abnormal events such as mutation and some cancers.In additions, c-Src protein is found to be highly activated and the Src gene is frequently over-expressed in many cancers.These findings suggest that the relationship between c-Src activation/over-expression and cancer progression appears to be significant.     

Relationship between persistent HPV infection and cervical carcinoma

Human papillomavirus (HPV) genital infection is a very common sexual transmitted disease. Mostly, the infection is transient and asymptomatic. The induction of effective immune responses usually allows the infection to be spontaneously cured. However, the infection sometimes can be responsible for an intraepithelial lesion, which may progress to be cervical cancer. Cervical cancer is one of the most common neoplastic diseases affecting women. It is clear that carcinogenic HPV infection is the necessary process for the development of cervical cancer. HPV infection is very frequent in young women aged less than 25 years and viral clearance lasts for 8 months in average. This clearance is the consequence of host immunity intervention, which leads to spontaneous regression of infection and the overwhelming majority of low-grade squamous intraepithelial lesions (more than 80% within a period of 2 years). The major factor, which permits the progression to high grade squamous intraepithelial lesions and invasive cervical cancer, is the persistent feature of HPV infection. HPV infection is usually transient, but several factors were identified as host factors (genetic, immunodepression, oral contraception and smoking) and viral factors (genotype, variants, viral load and integration) to increase the persistence. Cervical cancer is clearly the first virus-induced solid tumor discovered in human. Furthermore, it represents a woman death cause that can be avoided.     

Renaturing cities: from utopias to contested realities and futures

Renaturing urban environments is a transformative pathway for urban sustainability that can be leveraged for collaborative research and planning to reverse long trends of ecosystem degradation. People-nature connections need to be reinforced to enable the successful uptake and upscale of urban renaturing practices. Improving people’s understanding, perception, and emotions towards nature is therefore key. In this paper, we discuss how human knowledge and values of nature can be enabled through urban renaturing. Besides, we discuss the required transitions in urban planning processes to support urban renaturing practices.     

草莓脱毒及组培快繁研究

剥离培养0.3mm的草莓微茎尖,脱毒率可达100%.最佳芽诱导培养基为MS BA1.0mg/L;最佳继代培养基为MS十BA0.5mg/L;最佳生根培养基为MS BA0.1mg/L 活性碳1.0g/L.