鸭PPARs启动子扩增、序列比较及其转录因子表达模式的聚类分析

过氧化物酶体增殖物激活受体(peroxisome proliferators-activated receptors,PPARs)是核激素受体超家族的一员,分α、β/δ、γ3个亚型,是调节细胞生长和分化的重要因子.为了解PPARs各成员在鸭(Anas platyrhynchos)骨骼肌发育中的不同作用,本研究克隆了鸭PPARα、PPARβ和PPARγ基因启动子区,预测其共同转录因子结合位点,用qRT-PCR检测PPARs及共同转录因子在鸭胚及出生后骨骼肌发育过程中的表达,比较表达模式并进行聚类分析.结果表明,扩增出鸭PPARα、PPAEβ和PPARγ启动子序列分别为2 526、1 631和2 942 bp,GenBank登录号分别为KX845431、KX845432和KX845433.鸭PPARs启动子区存在典型的CAAT-box、TATA-box顺式作用元件,预测存在共同的特异性蛋白1(specificity protein 1,Sp1)、核因子κB(nuclear factor kappa B,NF-κB)和CCAAT增强子结合蛋白(CCAAT/enhancer binding protein alpha,C/EBP-α)转录因子结合位点.PPARs成员在鸭胸肌、腿肌组织中均有表达.在胸肌中,转录因子NF-κB与PPARβ基因的表达模式一致;在腿肌中,Sp1、NF-κB、PPARβ和PPARγ的表达模式一致.PPARs各成员均参与了骨骼肌的发育调控,PPARβ作用可能更大;PPAPβ、PPARγ在鸭骨骼肌发育过程中的功能可能相似;此外,NF-κB可能调控PPARβ在骨骼肌中的表达.研究结果为PPARs基因的表达和功能鉴定提供理论依据.     

Dexamethasone receptors and their distribution in the brain of the red tilapia

Cytosolic extracts of liver and brain showed specific, saturable binding with [³H]dexamethasone: Scatchard plots were linear. Cortisol and 11-deoxycortisol acted as competitors, whilst 17,20-dihydroxy-4-pregnen-3-one was relatively much less effective. There was a four-fold range of differences in specific binding capacity between dissected brain regions, the order being telencephalon > hypothalamus > rhombencephalon > optic tectum (thalamus + tegmentum + torus semicircularis) when N_max was calculated in terms of DNA content. There was no evidence for any binding of [³;H]dexamethasone with membrane fractions.     

Recent advance in macrophage pattern recognition receptors for lipopolysaccharide recognition

Sepsis is systemic inflammatory response syndrome (SIRS) associated with the presence of pathogenic microorganisms or their toxin. Lipopolysaccharide (LPS) is an important component of the outer membrane of Gram negative bacteria and has a pivotal role in inducing Gram negative sepsis. Macrophages play an essential role in infection and inflammation. Specific recognition of LPS is of particular importance in the defense system and pattern recognition receptors (PRR) have been considered to be important in initial steps for cellular recognition of LPS and consequence initiation of LPS responses. In the past few years, intense research in the fields of PRR and their recognition mechanism has been achieved. In this review, we attempt to expound recent research advances of macrophage PRRs for LPS recognition and their mechanism.     

Association analysis of the constructed linkage maps covering TLR2 and TLR4 with clinical mastitis in Norwegian Red cattle.

Toll-like receptors (TLR) are important cell-surface molecules mediating immune responses. Previous studies have identified TLR2 and TLR4 as potential candidate genes for disease resistance. In this study, dense linkage maps comprising single nucleotide polymorphisms (SNPs) have been constructed for the chromosomal regions harbouring TLR2 and TLR4 on bovine chromosome 17 and 8. The most likely marker orders for both regions were compared with the corresponding human map positions and used to reorder bovine scaffolds available from the bovine genome sequence assembly (Btau_3.1). A combined linkage and linkage disequilibrium method was used to investigate possible associations between the TLR genes and mastitis susceptibility recorded in the Norwegian Red cattle population. The analysis did not detect any significant association between the chromosomal regions surrounding TLR2 and TLR4 and mastitis in Norwegian Red cattle.     

Tamoxifen induces apoptosis and inhibits respiratory burst in equine neutrophils independently of estrogen receptors

Neutrophils play an important role in the exacerbation and maintenance of severe equine asthma; persistent neutrophil activity and delayed apoptosis can be harmful to surrounding tissues. Tamoxifen (TX) is a nonsteroidal estrogen receptor modulator with immunomodulatory effects and induces early apoptosis of blood and bronchoalveolar lavage neutrophils from horses with acute lung inflammation. This study investigated if the in vitro effects of tamoxifen are produced by its action on nuclear (α and β) and membrane (GPR30) estrogen receptors in healthy equine neutrophils. Results showed that TX inhibits neutrophil respiratory burst induced by opsonized zymosan in a dose‐dependent manner. Nuclear (17‐β‐Estradiol) and GPR30 cell membrane (G1) estrogen receptor agonists and their antagonists (ICI 182,780 and G15, respectively) do not block or reproduce the effect of TX. Therefore, TX does not inhibit respiratory burst through estrogen receptors. TX (8.5 μM) also increased phosphatidylserine translocation, a marker of early apoptosis, which did not occur with any of the estrogen receptor agonists or antagonists . Thus, tamoxifen generates dose‐dependent inhibition of respiratory burst and increased early apoptosis in healthy equine neutrophils, independently of nuclear or membrane estrogen receptors. Further studies are necessary to explore the signaling pathways of tamoxifen‐induced ROS inhibition and phosphatidylserine translocation.     

Expression of BMP Receptors in Porcine Granulosa Cells （GCs） and Their Regulation by Luteinizing Hormone （LH）

Bone morphogenetic proteins (BMPs) play critical roles in follicle growth and development. BMPs initiate signaling by assembling BMP receptors and activating Smads, which in turn alter expression of target enes. The mechanism underlying the regulation of the expression of BMP receptors and Smads during follicle development in pigs is still unknown. By quantitative real-time PCR, the mRNA expression of BMP receptors and Smads in granulosa cells (GC) was investigated.Cells were obtained from small porcine follicles (SF; <3 mm diameter) and dominant follicles (DF; >6 mm diameter); ActRIA and BMPR2 mRNA levels in DF were significantly higher (P<0.05) than that in SF, whereas BMPRIB, Smad4 and Smad7 expression tended to decrease (P>0.05). The levels of BMPRIA, ActR2, Smadl, Smad5, and Smad8 mRNA did not differ between DFs and SFs. To investigate the effect of LH on BMP receptors in GC, cells obtained from porcine DFs were cultured in medium supplemented with different doses of luteinizing hormone (LH). High doses of LH (4 IU mL-1)significantly decreased the concentration of estradiol (E2) and progesterone (P4) in medium and the expression of Cyp19a1 (P450 aromatase, P450arom) and Cypl lal (cholesterol side-chain cleavage enzyme P450, P450scc), while significantly increased viable cell numbers and up-regulated expression of cyclin dependent kinase-4 (CDK4) and cyclin D2. However,LH had no effect on the expression of BMP receptor genes. Thus, the present study indicates that the expression of members of the BMP signaling pathway in porcine GC is regulated during follicle development and the expression of BMP receptors are not regulated by LH in porcine GCs.     

中国铠甲虾类一新种和三新纪录

中国水产科学研究院南海水产研究所在1981—1982年对南海北部大陆斜坡进行调查,范围北纬18°30′—20°50′,东经112°00′—116°30′,水深250—950米,采集得不少铠甲虾,这是属于甲壳纲Crustacea歪尾次目Anomura铠甲虾总科Galatheoidea,计有六种;其中长额仿刺铠虾Munidopsis longirostris Edwards et Bouvier 1897及日本粒折尾虾Uroptychus granulatus japonicus Balss 1903东海也有已报导,本文从略。另有一新种和三新纪录,现报导如下:     

Expression of NF-κB,NR2B and iNOS in spinal cord in a rat model of neuropathic pain

AIM: To observe the expression of nuclear factor-kappa B (NF-κB), N-methyl-D-aspartic acid receptor 2B (NR2B) and inducible nitric oxide synthase (iNOS) in the spinal cord in a rat model of chronic constriction injury (CCI) of the sciatic nerve. METHODS: Fifty-six adult male Sprague-Dawley rats weighing 180~220 g were randomly divided into sham group (n=8) and CCI group (n=48). The mechanical withdrawal threshold (MWT) and paw withdrawal latency (PWL) of the hind paws were measured 1 d before CCI and 1 d, 4 d, 7 d, 14 d and 21 d after surgery. The L4~L6 segment of the spinal cord was taken for determining the expression of NF-κB, NR2B and iNOS by RT-PCR and Western blotting. RESULTS: At 1 d, 4 d, 7 d, 14 d and 21 d after surgery, the MWT and PWL in CCI group were obviously lower than those in sham group. The expression of NF-κB, NR2B and iNOS at mRNA and protein levels increased significantly. Positive correlations were found between the mRNA expression of NF-κB and iNOS (r=0.842, P<0.05), and between the mRNA expression of NR2B and iNOS (r=0.833, P<0.05). CONCLUSION: The generation and maintenance of hyperalgesia in sciatic nerve injury rats may attribute to the activation of NF-κB and NR2B and concomitant increase in iNOS.