FGF21及其受体FGFR1和FGFR2在小鼠毛囊第1生长周期的表达

旨在通过对FGF21、受体FGFR1和FGFR2在小鼠毛囊第1生长周期中的定位和表达情况的研究,以探索FGF21、受体FGFR1和FGFR2在毛囊发育过程中的作用。选取1、3、5、8、12、17、21和23日龄小鼠背部皮肤,采用免疫组织化学技术,实时荧光定量PCR和蛋白免疫印迹技术检测FGF21、FGFR1和FGFR2 mRNA及蛋白表达。结果显示:在小鼠毛囊第1生长周期中,FGF21主要表达于毛囊毛乳头、毛基质、内外根鞘以及毛囊周围的结缔组织中;FGFR1在毛囊各部均有表达,且在退化期(12～17日龄)和静止期(18～21日龄)主要表达于内外根鞘中;FGFR2广泛表达于毛囊各部。1、3、5、8、12、17日龄FGF 21 mRNA表达量极显著低于23日龄(P<0.01),21日龄的表达量低于23日龄,差异不显著(P>0.05);1～5日龄和23日龄FGF21蛋白表达量较高。1、3、5、8、12、21、23日龄FGFR1 mRNA表达量极显著低于17日龄(P<0.01);FGFR1蛋白表达量从12日龄开始上升,在17日龄时达到最高,之后又呈下降趋势。1、5、8、12、21和23日龄FGFR2 mRNA表达量极显著低于17日龄(P<0.01),在3日龄的表达量低于17日龄,差异不显著(P>0.05);FGFR2蛋白在1～17日龄都有较高表达。综上表明,在第1个毛囊生长周期中,FGF21对参与毛囊形成的成纤维细胞的增殖和分化具有重要作用,诱导毛囊由生长期进入退化期。FGFR1对内外根鞘细胞的增殖、分化有着明显作用,诱导毛囊由退化期进入静止期。FGFR2对毛囊内细胞增殖、分化具有重要作用,诱导毛囊由生长期和退化期进入静止期。     

Evidence of LAT1 expression in canine caput epididymis

L-type amino acid transporter 1 (LAT1), the first isotype of amino acid transport system L, transports aromatic and branched amino acids pivotal for fundamental cellular activities such cellular growth and proliferation. LAT1 expression was high only in the brain in contrast to its limited distribution and low level of expression in normal tissues. We found potent LAT1 expression in canine caput epididymis by quantitative RT-PCR and Western blotting analysis. Immnuno-histochemical examination revealed observable LAT1 in microvillous epithelial cells.     

Downregulation of the expression of inhibin α subunit and betaglycan in porcine cystic follicles

Inhibins, as members of the transforming growth factor beta (TGF-β) superfamily, downregulate the synthesis and secretion of follicle-stimulating hormone (FSH) in an endocrine manner. The role of inhibin/betaglycan in the ovary regulation recently gained attention. To date, no data exist on the function of inhibin α subunit and betaglycan in cystic follicles. In this study, the expressions of inhibin α subunit and betaglycan in cystic follicles were investigated using immunohistochemistry, real-time PCR and Western blot analysis. Both inhibin α subunit and betaglycan immunoreactivities were mainly localized in the granulosa cells of follicles. Expression of inhibin α subunit and betaglycan was inferior in cystic follicles compared with that in normal large follicles. However, the result of enzyme-linked immunosorbent assay showed no significant difference in the decreasing in concentration of inhibin α subunit in cystic follicular fluid compared with the control (P>0.05). In this study, we explored the effects of FSH on betaglycan expression in granulosa cells in vitro. As expected, a significant increase in the expressions of betaglycan mRNA and protein in granulosa cells was observed in response to exogenous FSH (30 ng/ml) (P<0.05) compared with the control. Consequently, this study provides evidence that the expressions of inhibin α subunit and betaglycan are inferior in cystic follicles, and this may be caused by the decrease in FSH in the presence of a cystic follicle.     

PP1γ2对树鼩精子成熟和运动性的调控作用研究

为了阐明树鼩精子中是否存在丝氨酸/苏氨酸蛋白磷酸酶1γ2(PP1γ2)及其在附睾精子中的存在形式,进而探究PP1γ2对精子成熟和运动性的调控作用,本试验以树鼩为研究对象,采用Western blotting分析了不同条件下树鼩附睾头和附睾尾精子中PP1γ2的存在形式和磷酸化程度,探讨了双丁酰环腺苷酸(db-cAMP)、3-异丁基-1-甲基黄嘌呤(IBMX)或Ca²⁺对树鼩精子中PP1γ2磷酸化表达水平的影响,并进一步研究了磷酸酶抑制剂冈田酸(okadaic acid,OA)和花萼海绵诱癌素A(calyculin A,CA)对树鼩精子中PP1γ2磷酸化程度的影响及其对树鼩附睾头和附睾尾精子运动度的影响。结果显示,在树鼩附睾头和附睾尾精子中均存在PP1γ2,且在等量的附睾头和附睾尾精子蛋白中,PP1γ2在附睾尾精子的磷酸化程度远高于附睾头精子;db-cAMP、IBMX或Ca²⁺不改变PP1γ2的磷酸化水平;磷酸酶抑制剂OA和CA能明显提高附睾头和附睾尾中PP1γ2磷酸化的程度,且能显著提高精子(尤其是附睾头精子)的运动度(P<0.05),OA和CA的最佳作用浓度分别为1μmol/L和10 nmol/L,最佳作用时间分别为15、20 min。本研究结果表明,蛋白磷酸酶PP1γ2对树鼩精子成熟及运动性具有重要的调控作用,其主要通过磷酸化和去磷酸化的变化发挥作用。     

畜禽Nramp1基因抗病作用的研究进展

Nramp1基因作为影响畜禽抗病育种中抗病力的主要候选基因之一,其蛋白可抵抗多种胞内菌的侵染,从而提高畜禽抗病力。主要叙述Nramp1基因的结构特点和作用机理,综述了Nramp1基因与抗病性状的关系,并对其应用前景进行了展望。     

DETERMINATION OF T1 RELAXATION TIME OF NORMAL EQUINE TENDONS USING MAGIC ANGLE MAGNETIC RESONANCE IMAGING

Seven isolated equine front limbs were used to establish the normal T1 relaxation time of equine superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), and suspensory ligament (SL) using magic angle magnetic resonance (MR) imaging. MR imaging of the metacarpi was performed with the limbs positioned at 55° (the magic angle) relative to the main magnetic field. Transverse spin‐echo proton density and inversion recovery images were acquired. T1 relaxation time was calculated based on ratios of signal intensity determined from the different pulse sequences. T1 relaxation times for SDFT, DDFT, and SL were 288 (±17), 244 (±14), and 349 (±16) ms, respectively. The difference in T1 values between SDFT, DDFT, and SL was statistically significant. T1 values of equine tendons can be determined with magic angle imaging on a clinical MR system using <10 min total scan time. The knowledge of the normal range of T1 values may be useful to identify horses with chronic tendinopathy, where based on the human literature, an increased T1 value may be expected.     

Analysis of human infectious avian influenza virus: Hemagglutinin genetic characteristics in Asia and Africa from 2004 to 2009

In the present study, we used nucleotide and protein sequences of avian influenza virus H5N1, which were obtained in Asia and Africa, analyzed HA proteins using ClustalX1.83 and MEGA4.0, and built a genetic evolutionary tree of HA nucleotides. The analysis revealed that the receptor specificity amino acid of A/HK/213/2003, A/Turkey/65596/2006 and etc mutated into QNG, which could bind with á–2, 3 galactose and á–2, 6 galactose. A mutation might thus take place and lead to an outbreak of human infections of avian influenza virus. The mutations of HA protein amino acids from 2004 to 2009 coincided with human infections provided by the World Health Organization, indicating a “low–high–highest–high–low” pattern. We also found out that virus strains in Asia are from different origins: strains from Southeast Asia and East Asia are of the same origin, whereas those from West Asia, South Asia and Africa descend from one ancestor. The composition of the phylogenetic tree and mutations of key site amino acids in HA proteins reflected the fact that the majority of strains are regional and long term, and virus diffusions exist between China, Laos, Malaysia, Indonesia, Azerbaijan, Turkey and Iraq. We would advise that pertinent vaccines be developed and due attention be paid to the spread of viruses between neighboring countries and the dangers of virus mutation and evolution.     

全球人感染H5N1禽流感病例流行病学特征分析

该文基于近年来国内外报道的H5N1亚型高致病性禽流感病毒感染人的病例,系统分析了人感染H5N1禽流感病毒的流行病学特征,阐述人禽流感暴发流行的可能性及预防控制的紧迫性。     

The stimulatory effect of insulin-like growth factor-1 on the proliferation, differentiation, and mineralisation of osteoblastic cells from Holstein cattle

This study investigated the effect of exogenous insulin-like growth factor (IGF)-1 on the proliferation and differentiation of osteoblastic cells from Chinese Holstein cattle and the resultant bone nodule formation and mineralisation in vitro. The osteoblastic cells were isolated and cultured, then identified using Giemsa and alkaline phosphatase (ALP) staining methods. The effect of different concentrations of IGF-1 on cell growth was assessed by MTT assay. The ALP activity and osteocalcin (OC) concentration in the osteoblastic cells were measured by a colorimetric assay and a radioimmmunoassay, respectively. Calcium nodules were observed using alizarin red S stain, while the content of matrix calcium was determined by atomic absorption spectrophotometry. Cell proliferation in the cultures was stimulated by IGF-1 at concentrations ranging from 1 to 200 ng/mL, with the maximum effect observed at 100 ng/mL. This effect was observed from day 1 and peaked at day 5, but decreased at day 7. At concentrations of 10 ng/mL and 100 ng/mL, IGF-1 significantly induced ALP activity, OC level, matrix calcium content, and nodule formation of the osteoblastic cells by 20–180% (P < 0.05 or P < 0.01), compared to controls. The results suggested that IGF-1 is an anabolic agent for the proliferation, differentiation, mineralisation and calcium content of dairy cow osteoblasts, and could therefore act as a potential treatment for the metabolic bone diseases in these animals.