Early pregnancy regulates expression of complement components in ovine liver

Complement pathways participate in the regulation of innate immune system, and complement activation is inhibited in normal pregnancy. The liver plays key roles in the modulation of immunity and tolerance, but it is unclear that early pregnancy induces the changes in expression of complement components in the ovine maternal liver. The aim of the present study was to explore the expression of complement components in the liver using quantitative real-time polymerase chain reaction (PCR), Western blot, and immunohistochemistry. Maternal livers were collected on Day 16 of the estrous cycle and Days 13, 16, and 25 of gestation. The results indicated that early pregnancy suppressed the expression of C1q, C1r, C1s, C2, C4a, C5b, and C9 in the maternal liver, but C3 expression was increased. In addition, C3 protein was located in the endothelial cells of the proper hepatic arteries and portal veins and hepatocytes. In summary, the downregulaltion of C1q, C1r, C1s, C2, C4a, C5b, and C9 may be involved in the suppression of complement activation, and upregulation of C3 is related to the modulation of maternal immune tolerance in ovine liver.     

Toll-like receptor signaling is changed in ovine lymph node during early pregnancy

Toll-like receptors (TLRs) participate in regulation of adaptive immune responses, and lymph nodes play key roles in the initiation of immune responses. There is a tolerance to the allogenic fetus during pregnancy, but it is unclear that expression of TLR signaling is in ovine lymph node during early pregnancy. In this study, lymph nodes were sampled from day 16 of nonpregnant ewes and days 13, 16, and 25 of pregnant ewes, and the expressions of TLR family (TLR2, TLR3, TLR4, TLR5 and TLR9), adaptor proteins, including myeloid differentiation primary-response protein 88 (MyD88), tumor necrosis factor receptor associated factor 6 (TRAF6), and interleukin-1-receptor-associated kinase 1 (IRAK1), were analyzed through real-time quantitative polymerase chain reaction, Western blot, and immunohistochemistry analysis. The results showed that mRNA and protein levels of TLR2, TLR3, TLR4, TRAF6, and MyD88 were upregulated in the maternal lymph node, but TLR5, TLR9, and IRAK1 were downregulated during early pregnancy. In addition, MyD88 protein was located in the subcapsular sinus and lymph sinuses. Therefore, it is suggested that early pregnancy induces changes in TLR signaling in maternal lymph node, which may be involved in regulation of maternal immune responses in sheep.     

Observations on some treatments of ovine pregnancy toxaemia

Extract

An ancient treatment for pregnancy toxaemia was to drive the affected sheep until they either recovered or died. Numerous other treatments are recorded in the literature, but no precise figures for recovery rates are quoted to enable comparisons to be made with more recent methods. Failure to produce a rational treatment results from the unknown aetiology of the disease. Many reports of successful treatments have been based on trials with inadequate numbers of affected sheep and some have not included untreated controls.     

Effects of intrauterine growth restriction during late pregnancy on the ovine fetal renal function and antioxidant capacity

This study investigated the effects of intrauterine growth restriction during late pregnancy on the ovine fetal renal function and renal antioxidant capacity. Eighteen ewes pregnant were randomly divided into control group (CG, ad libitum, 0.67 MJ ME·BW^−0.75·day⁻¹, n = 6), restricted group 1 (RG1, 0.18 MJ ME·BW^−0.75·day⁻¹, n = 6), and restricted group 2 (RG2, 0.33 MJ ME·BW^−0.75·day⁻¹, n = 6). At 140 days, the fetal blood, allantoic fluid and kidney tissue were collected to determinate fetal renal function and renal antioxidant capacity. The results showed that the fetal weight, kidney weight, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), aquaporin-2 (AQP-2) and aquaporin-3 (AQP-3), and total antioxidant capacity (T-AOC) in RG1 group were decreased compared with the CG (P < 0.05), but the contents of β2-Microglobulin (β 2-MG), cystatin C (Cys-C), filtered sodium excretion fraction (FENa), malondialdehyde (MDA), and hydroxyl radical (OH) in RG1 group were increased (P < 0.05). The impaired ovine fetal renal growth, antioxidant imbalance and dysfunction of glomerulus ultrafiltration, and the renal tubules reabsorption were induced by maternal malnutrition during late pregnancy.     

Structure and expression of ovine complement receptor type 2

The structure of sheep complement receptor type 2 (CR2) was characterised by cDNA cloning, protein sequencing and immunoprecipitation. The primary structure of sheep CR2 is similar to known mammalian homologues but the higher-order structure is unusual. Two distinct CR2 isoforms occur, one of which is ubiquitinated in the cytoplasmic domain, and the two molecular forms are expressed at the cell surface as non-covalently associated dimers. The percentage of sheep B-cells that express CR2 changes during development and varies between different body compartments. CR2+ and CR2 B-cell subsets also differ in the expression of other surface markers and in functional properties. Differential expression of CR2 may, therefore, delineate B-cells that arose by alternative developmental pathways, or it could be a marker for B-cells at different phases of antigen exposure.     

Effects on ovine fetuses of exposure to ovine progressive pneumonia virus

Fetuses of 20 pregnant ewes at 4 gestational periods (45, 55, 85, and 100 days) were inoculated with ovine progressive pneumonia virus. Fourteen of 16 fetuses exposed to virus before gestational day 80 were either resorbed or expelled, whereas 10 of 15 fetuses exposed to virus after day 80 were normal at birth. Three of the 9 expelled fetuses and 1 of 2 newborn lambs had accumulations of lymphoid cells in the lungs. Virus was readily isolated from the tissues of expelled fetuses and newborn lambs. Lambs did not have precipitating antibody to the virus at birth, but 3 to 5 lambs had specific antiviral antibody at 18 months of age.     

Evaluation of the cold complement fixation test for diagnosis of ovine brucellosis

SUMMARY A cold complement fixation test for ovine brucellosis in which fixation of complement occurs for 16 h at 4°C was compared with the conventional warm complement fixation test in which fixation takes place for 40 minutes at 37°C. The cold complement fixation test detected experimentally infected animals up to one week sooner than the warm complement fixation test and the titres were approximately one twofold dilution higher. Similar results were obtained when the 2 tests were compared using 11,922 serum samples collected from 700 ram flocks over a 2-year period. False positive reactions were observed in less than 0.1% of cases.     

鱼类补体系统的研究进展

补体系统可警示宿主有病原微生物存在,其激活对于获得性免疫发展有重要作用.本文综述了鱼类补体系统组成、特点、功能,补体激活的途径、影响因素及展望.     

粟糠对母猪妊娠前期行为、血液生化指标及生殖激素的影响

粟糠中含有丰富的纤维素和半纤维素,是一种产量较大的可再生利用资源,是重要的膳食纤维来源,但是粟糠在母猪上的应用报道很少。为研究粟糠对妊娠母猪前期的行为、血清生化指标及生殖激素的影响,试验选用32头胎次、配种时间及体况均相近的大×长二元母猪,采用单因子完全随机设计,分对照组、试验Ⅰ组、试验Ⅱ组和试验Ⅲ组,每组8个重复,限位栏饲养,粟糠的添加水平分别为:0%、9%、17%和24.5%,每组的消化能和粗蛋白质基本一致。结果表明:(1)日粮添加粟糠降低了妊娠母猪前期咬栏行为(P<0.05)、舔地行为和站立时间(P<0.01),增加趴卧时间(P<0.05)。(2)降低血清总胆固醇含量(P<0.01)、雌二醇含量(P<0.05),增加孕激素含量(P<0.01)。本试验研究表明妊娠母猪前期日粮中添加粟糠增加了母猪的趴卧休息时间,降低了咬栏、添地等刻板行为,降低血清总胆固醇含量和雌二醇含量,提高了孕激素含量,有利用母猪孕期的子宫内膜增生,受精卵植入,并降低子宫肌肉兴奋度,保证孕期安全。     

Effects of complement component 3 derivatives on pig oocyte maturation, fertilization and early embryo development in vitro

Complement component 3 (C3) has well-established roles within immune system, but its roles outside of immune system are less characterized. The extensive presence of C3 throughout the female reproductive tract, and its temporal, and gamete-specific regulation of expression suggest a potential role for C3 in reproduction. In the present investigation, the effects of C3, C3b and iC3b on porcine oocyte maturation, fertilization and embryonic development were examined. We identified the ability of iC3b to positively influence oocyte maturation. No effects on fertilization efficiency, penetration rates, polyspermy and blastocyst formation were observed. However, C3, C3b and iC3b presence in embryo culture medium resulted in fewer total cells in test blastocysts compared to control blastocysts. The results of this study indicate a potential function for iC3b in oocyte maturation. Furthermore, it was demonstrated that the presence of either C3, C3b or iC3b has a negative influence on early embryonic development in the porcine species.