Brucella induces unfolded protein response and inflammatory response via GntR in alveolar macrophages

Brucella is an intracellular bacterium that causes the zoonosis brucellosis worldwide. Alveolar macrophages (AM) constitute the main cell target of inhaled Brucella. Brucella thwarts immune surveillance and evokes endoplasmic reticulum (ER) stress to replicate in macrophages via virulence factors. The GntR regulators family was concentrated as an important virulence factor in controlling virulence and intracellular survival of Brucella. However, the detailed underlying mechanism for the host-pathogen interaction is poorly understood. In this study the BSS2_II0438 mutant (ΔGntR) was constructed. The type IV secretion system (T4SS) virulence factor genes (VirB2, VirB6, and VirB8) were down-expression in ΔGntR. ΔGntR could infect and proliferate to high titers in GAMs without a significant difference compared with the parental strain. ΔGntR infection increased the expression of ER stress marker genes GRP78, ATF6, and PERK in the early stages of its intracellular cycle but decreased the expression of these genes in the late stages. ΔGntR increased greatly the number of Brucella CFUs in the inactive ER stress state in GAMs. Meanwhile, ΔGntR infection increased the levels of IFN-γ, IL-1β, and TNF-α, indicating ΔGntR could induce the secretion of inflammatory but not anti-inflammatory cytokines IL-10. Taken together, our results clarified the role of the GntR in B. suis. S2 virulence expression and elucidated that GntR is potentially involved in the signaling pathway of the Brucella-induced UPR and inflammatory response in GAMs.

Bta-miR-130a regulates the biosynthesis of bovine milk fat by targeting peroxisome proliferator-activated receptor gamma

Milk fat determines the quality of milk and is also a main targeted trait in dairy cow breeding. Recent studies have revealed important regulatory roles of microRNAs (miRNA) in milk fat synthesis in the mammary gland. However, the role of miRNA in bovine mammary epithelial cells (BMEC) remains largely unknown. In this study, we found that the overexpression of miR-130a significantly decreased cellular triacylglycerol (TAG) levels and suppressed lipid droplet formation, whereas the inhibition of miR-130a resulted in greater lipid droplet formation and TAG accumulation in BMEC. MiR-130a also significantly affected mRNA expression related to milk fat metabolism. Specifically, the overexpression of miR-130a reduced the mRNA expression of , , , and , whereas the downregulation of miR-130a increased the mRNA expression of , , , , , and . Furthermore, western blot analysis revealed the protein level of PPARG in miR-130a mimic and inhibitor transfection groups to be consistent with the mRNA expression response. Finally, luciferase reporter assays verified that PPARG was the direct target of miR-130a. This study provides the first experimental evidence that miR-130a directly affects TAG synthesis in BMEC by targeting PPARG, suggesting that miR-130a potentially could be used to improve beneficial milk components in dairy cows.

miR-27a controls triacylglycerol synthesis in bovine mammary epithelial cells by targeting peroxisome proliferator-activated receptor gamma

Growing evidence has revealed that microRNA are central elements in milk fat synthesis in mammary epithelial cells. A negative regulator of adipocyte fat synthesis, miR-27a has been reported to be involved in the regulation of milk fat synthesis in goat mammary epithelial cells; however, the regulatory role of miR-27a in bovine milk fat synthesis remains unclear. In the present study, primary bovine mammary epithelial cells (BMEC) were harvested from mid-lactation cows and cultured in Dulbecco's modified Eagle's medium/F-12 medium with 10% fetal bovine serum, 5 μg/mL of insulin, 1 μg/mL of hydrocortisone, 2 μg/mL of prolactin, 1 μg/mL of progesterone, 100 U/mL of penicillin, and 100 μg/mL of streptomycin. We found that the overexpression of miR-27a significantly suppressed lipid droplet formation and decreased the cellular triacylglycerol (TAG) levels, whereas inhibition of miR-27a resulted in a greater lipid droplet formation and TAG accumulation in BMEC. Meanwhile, overexpression of miR-27a inhibited mRNA expression of peroxisome proliferator-activated receptor gamma (PPARG), CCAAT/enhancer-binding protein beta (C/EBPβ), perilipin 2 (PLIN2), and fatty acid binding protein 3 (FABP3), whereas miR-27a downregulation increased PPARG, C/EBPβ, FABP3, and CCAAT enhancer binding protein alpha (C/EBPα) mRNA expression. Furthermore, Western blot analysis revealed the protein level of PPARG in miR-27a mimic and inhibitor transfection groups to be consistent with the mRNA expression response. Moreover, luciferase reporter assays verified that PPARG was the direct target of miR-27a. In summary, these results indicate that miR-27a has the ability to control TAG synthesis in BMEC via targeting PPARG, suggesting that miR-27a could potentially be used to improve beneficial milk components in dairy cows.

Effects in cattle of genetic variation within the IGF1R gene on the superovulation performance and pregnancy rates after embryo transfer

The insulin-like growth factor 1 receptor (IGF1R) is a membrane glycoprotein mediating most biological actions of IGF1 and IGF2, and has an important effect on ovulation, pre-implantation embryo development and pregnancy rate. The objectives of this study were to detect IGF1R gene polymorphisms of cattle and analyze the relationship with superovulation performance and pregnancy rates after embryo transfer (ET), as well as the hormone concentrations at the day of ET. One reported SNP of IGF1R G404T and a novel SNP of IGF1R G399A were analyzed in 170 Chinese Holstein donor cows and 118 Luxi recipients cattle. Statistical analysis revealed that the G404T mutation was associated (p=0.019) with increased ovulation rate and females with this mutation had enhanced performance in producing transferable embryos. For the polymorphic locus G399A, recipients with g.399 GG and g.399 GA genotypes had greater pregnancy rates after ET than that of g.399 AA genotype. Furthermore, the same tendency was observed that the genotype groups with greater pregnancy rates had greater progesterone and lesser estrogen concentrations, but these did not reach statistical significance. Results of the present study showed, for the first time, that the polymorphism in IGF1R is associated with superovulation traits, and indicated that the IGFIR gene can be used as a potential marker for donor selection.

Effects of polymorphisms in the bovine growth differentiation factor 9 gene on sperm quality in Holstein bulls

Members of the transforming growth factor-β (TGFβ) superfamily are critical regulators of germ cell development that act as extracellular ligands of the signal transduction pathways regulating proliferation, differentiation, apoptosis, and other aspects of cell behavior. Growth differentiation factor 9 (GDF9) is a member of the TGFβ superfamily that plays a critical role in ovarian follicular development and ovulation rate in females; however, its role in the testis has not been well elucidated. Therefore, in this study we investigated the effects of GDF9 mutations on the quality of fresh and frozen semen of Holstein bulls. Two reported single nucleotide polymorphisms of GDF9, A485TA and A625C, were analyzed in 129 Holstein bulls. Analysis of variance revealed that the A485T polymorphism had significant effects on the acrosome integrity rate (P < 0.05), whereas the A625T polymorphism was significantly associated with sperm concentration (P < 0.05). In addition, a significant additive effect on sperm concentration was detected for the A485T polymorphism (P < 0.05), whereas the polymorphisms A485TA and A625C had significant dominant effects on acrosome integrity rate and sperm motility in frozen semen, respectively (P < 0.05). This study is the first to show a significant association of GDF9 with sperm quality traits, and the results implied that GDF9 is involved in the initiation or maintenance of spermatogenesis; however, further verification is needed.

Enhancement of recombinant adeno-associated virus mediated transgene expression by targeted echo-contrast agent

Ultrasound-targeted microbubble destruction (UTMD) has been recently developed for destroying bubbles carrying drugs or genes, thereby permitting local release of these target molecules. We investigated whether SonoVue®, a new contrast agent that contains phospholipid-stabilized microbubbles filled with sulfur hexafluoride vapor, is effective at delivering a recombinant adeno-associated viral (rAAV) vector to the rat heart by UTMD. Serotype-2 (rAAV2) marked with green fluorescent protein (GFP) as a reporter gene was attached to the surface of sulfur hexafluoride-filled microbubbles. Microbubbles were infused into the tail vein of rats with or without simultaneous echocardiography. Additional controls included ultrasound microbubbles that did not contain virus, virus alone, and virus plus ultrasound. One group underwent echocardiographic destruction of microbubbles followed by rAAV2-GFP infusion. Rats were killed after 4 weeks and examined for GFP expression. Green fluorescence was detected in all groups that received the rAAV2-GFP vector, indicating expression of the rAAV2 transgene; however, GFP expression in the UTMD group was significantly higher than that in control groups. We conclude that ultrasound-mediated destruction mediated by SonoVue is a promising method for delivery of rAAV2 to the heart in vivo.

GDF-9 and bFGF enhance the effect of FSH on the survival, activation, and growth of cattle primordial follicles

This study aims to investigate the effects of follicle stimulating hormone (FSH) in combination with growth and differentiation factor-9 (GDF-9) or basic fibroblast growth factor (bFGF) on the activation, survival and growth of cattle primordial follicles. Ovarian tissues were cultured for 3, 7, 14, 22 days in α minimum essential medium (α-MEM) supplemented with FSH, FSH+GDF-9 or FSH+bFGF. Non-cultured and cultured ovarian fragments were processed for histological and TUNEL analysis. Compared to the FSH medium, the results showed FSH+GDF-9 medium increased the percentage of primary follicles in all culture periods and secondary follicles after 14 days of culture (P<0.05), meanwhile the diameter of primary and secondary follicles were also observed to increase in this medium after 7 days of cultures (P<0.05). FSH+bFGF medium appeared to increase the percentage of primary follicles after 14 days of culture and secondary follicles at day 14 of culture than FSH medium (P<0.05). Furthermore, the FSH+GDF-9 and FSH+bFGF mediums had a greater percentage of normal follicles, and lesser apoptotic cell rates than FSH medium. The results first indicated that FSH in combination with GDF-9 or bFGF can improve the survival, activation, and growth of cattle primordial follicles after the long-term culture of ovarian cortex.

Genetic diversity analysis of an indigenous Chinese buffalo breed and hybrids based on microsatellite data

Chinese native buffaloes have faced the threat of extinction, along with an increase in crossbreeding with domesticated river buffaloes; consequently, conservation of local buffalo genetic resources has become a priority. A Chinese native breed, Jianghan, is often crossed intentionally and unintentionally with imported breeds from India and Pakistan, Murrah, and Nili-Ravi. A total of 128 buffaloes of the breeds Jianghan, Murrah, and Nili-Ravi and their presumed hybrid offspring were genotyped for 10 microsatellite markers. Heterozygosity and Wright's F-statistics were calculated to determine the genetic variation in those populations. The observed average heterozygosities ranged from 0.836 (Murrah) to 0.986 (Jianghan), higher than the expected heterozygosities and all the inbreeding values within the populations were negative. The genetic distances between the presumed hybrid buffaloes and the two imported river type dairy buffalo breeds (Murrah and Nili-Ravi) were lower than with the native Jianghan, indicating strong contributions of the imported breeds to this presumed hybrid buffalo population. This information will be useful for the development of rational breeding for the dairy buffalo industry and for conservation strategies for the Jianghan buffalo.

Association analysis between variants in bovine progesterone receptor gene and superovulation traits in Chinese Holstein cows

The objective of this study was to identify a predictor to forecast superovulation response on the basis of associations between superovulation performance and gene polymorphism. The PCR-RFLP method was applied to detect two reported single nucleotide polymorphisms (SNPs) of G59752C and T81637C (rs41614030) located in introns 3 and 4 of the bovine progesterone receptor (PGR) gene in 171 Chinese Holstein cows treated for superovulation and evaluate its associations with superovulation traits. In polymorphic locus 81637, all cows without superovulation response were g.81637TC and g.81637TT genotypes. Association analysis showed that these two SNPs had significant effects on the total number of ova (TNO) (p<0.05), and the T81637C polymorphism was significantly associated with the number of transferable embryos (p<0.05). In addition, significant additive effects (p<0.05) on TNO were detected in the polymorphisms of G59752C and T81637C. These results showed for the first time that the G59752C and T81637C polymorphisms in PGR gene were associated with superovulation traits and indicated that PGR gene can be used as a predictor for superovulation in Chinese Holstein cows.

An MspI polymorphism in the inhibin alpha gene and its associations with superovulation traits in Chinese Holstein cows

To identify a predictor to forecast superovulation response on the basis of associations between superovulation performance and gene polymorphism, the PCR-RFLP method was applied to detect an A>G transition determining an MspI polymorphism at position 192 in the exon I of the bovine inhibin alpha (INHA) gene and evaluate its associations with superovulatory response in 118 Chinese Holstein cows treated for superovulation. Association analysis showed that cows with the GG genotype resulted in a significant increase in the number of ova (TNO) than AG and AA genotypes in the first (P=0.023), second (P=0.004) and third (P=0.002) superovulation treatments and produced more transferable embryos (NTE) than that of AG and AA genotypes in the third (P=0.045) superovulation treatment. Moreover, individuals with GG genotype produced more transferable embryos than AA (P<0.05) genotype in the second superovulation treatment and all cows without superovulation response were mutations with genotypes of AA and AG. These results indicate that INHA gene can be used as a predictor for superovulation in Chinese Holstein cows, and imply that cows with AA genotype should be excluded for superovulation practices.

Polymorphisms in the 5' upstream region of the FSH receptor gene, and their association with superovulation traits in Chinese Holstein cows

To identify a predictor to forecast superovulation response on the basis of associations between superovulation performance and gene polymorphism, variation in the bovine follicle stimulating hormone receptor (FSHR) gene was investigated using PCR-single-strand conformational (PCR-SSCP) and DNA sequencing. One single nucleotide polymorphism (SNP) of G-278A located in the 5' upstream region of bovine FSHR gene was found in 118 Chinese Holstein cows treated for superovulation. Two SNPs of G-278A (GU253337) and A-320T (rs43676359) were analyzed. In polymorphic locus -278, all cows without superovulation response were mutations with genotypes of CD and DD. Cows with CC genotype had a significant increase in the total number of ova (TNO) (P<0.01), and produced more transferable embryos (NTE) than those of the CD and DD genotypes (P<0.01). At this locus, the additive effects seemed to be highly significant (P<0.01) and allele C was associated with an increase in the TNO and NTE. These results indicated that the FSHR is a potential marker for superovulation response and can be used as a predictor for superovulation in Chinese Holstein cows.

Inhibition of TPA and 12(S)-HETE-stimulated tumor cell adhesion by prostacyclin and its stable analogs: rationale for their antimetastatic effects

We have investigated the regulatory role of PGI2 and its stable analogs, i.e., iloprost and cicaprost, on 12(S)-HETE- and TPA-enhanced tumor cell integrin expression and adhesion. Walker 256 carcinosarcoma cells express alpha IIb beta 3 integrin receptors, which mediate their adhesion to endothelium, subendothelial matrix and fibronectin. Adhesion is enhanced by treatment with exogenous 12(S)-HETE but not 12(R)-HETE or other lipoxygenase-derived hydroxy fatty acids, as well as by TPA. Both 12(S)-HETE and TPA enhanced alpha IIb beta 3 expression on W256 cells. PGI2 iloprost and cicaprost inhibited both 12(S)-HETE- and TPA-enhanced adhesion to endothelium and subendothelial matrix as well as alpha IIb beta 3 expression on W256 cells. The mechanism responsible for the effect of PGI2 was explored. Prostacyclin treatment of W256 cells resulted in an enhanced production of cAMP in a time- and dose-dependent manner. Pre-treatment of tumor cells with increasing concentrations of adenosine resulted in a dose-dependent decrease in the PGI2 effect on TPA or 12(S)-HETE-enhanced adhesion, suggesting that the PGI2 effect is mediated through PKA. Dibutyryl cAMP also blocked the 12(S)-HETE- or TPA-enhanced adhesion, and adenosine pre-treatment did not result in an inhibition of the dibutyryl cAMP effect. Collectively, our results suggest that the cyclooxygenase metabolite PGI2 can antagonize the lipoxygenase metabolite 12(S)-HETE- and TPA-enhanced alpha IIb beta 3 expression and tumor cell adhesion via activation of adenylate cyclase and elevation of intracellular levels of cAMP.