RESUMO
Glycosphingolipid biosynthesis-globo series pathway genes (FUT1, FUT2, ST3GAL1, HEXA, HEXB, B3GALNT1, and NAGA) play an important regulatory role in the defense against Escherichia coli F18 in piglets. In this study, we identified the transcription initiation site and promoter of this gene cluster by mined previous RNA-seq results using bioinformatics tools. The FUT1 transcription initiation region included five alternative splicing sites and two promoter regions, whereas each of the six other genes had one promoter. Dual luciferase reporter results revealed significantly higher transcriptional activity by FUT1 promoter 2, indicating that it played a more important role in transcription. The promoters of glycosphingolipid biosynthesis genes identified contained a CpG island within the first 500 bp, except for the B3GALNT1 promoter which included fewer CpG sites. These results provide a deeper insight into methylation and the regulatory mechanisms of glycosphingolipid biosynthesis-globo series pathway genes in piglets.
Assuntos
Fucosiltransferases/genética , Glicoesfingolipídeos/biossíntese , Regiões Promotoras Genéticas , Suínos/genética , Animais , Ilhas de CpG , Metilação de DNA , Fucosiltransferases/metabolismo , Ativação Transcricional , Galactosídeo 2-alfa-L-FucosiltransferaseRESUMO
Natural resistance-associated macrophage protein gene 1 (Nramp1) plays an important role in the innate immune response of swine, and is believed to influence disease resistance. In this study, a real-time quantitative polymerase chain reaction technique was used to investigate Nramp1 expression in 12 different tissues in newborn and 7-, 14-, 21-, 28-, and 35-day-old Meishan piglets. Results indicated that Nramp1 was expressed to varying degrees in all sample tissues, although expression differed among growth stages. For example, Nramp1 was highly expressed in the spleen, but minimally expressed in heart, liver, and muscle tissues among the various piglet age classes. Overall, Nramp1 expression increased with age, reaching significant levels in 21- and 28-day-old animals. Nramp1 was expressed in all 12 tissues tested; however, expression in spleen, lung, kidney, and thymus tissues was highest among newborns, which is consistent with this gene's role in innate immunity improvement. Before and after weaning, Nramp1 was highly expressed in digestive (stomach) and intestinal (duodenum, jejunum, and ileum) tissues, further indicating a genetic role in both immune regulation to compensate for weaning stress and enhanced development of intestinal immunity.
Assuntos
Animais Recém-Nascidos/genética , Proteínas de Transporte de Cátions/genética , Sus scrofa/genética , Animais , Regulação da Expressão Gênica no Desenvolvimento , Imunidade Inata , Suínos , Distribuição Tecidual , DesmameRESUMO
We analyzed LTßR mRNA expression in piglets from birth to weaning and compared the differential expression between Escherichia coli F18-resistant and sensitive populations to determine whether this gene could be used as a genetic marker for E. coli F18 resistance. Sutai piglets of different age groups (8, 18, 30, and 35 days; N = 4 each) and piglets demonstrating resistance/sensitivity to E. coli F18 were used. LTßR expression levels were determined by real-time PCR. The LTßR expression levels in the lymph node, duodenum, and jejunum were significantly higher in 8-day-old piglets than in the other age groups (P < 0.01), and the expression levels were significantly higher in the lungs of 8-day-old piglets than in 35-day-old piglets (P < 0.01) and 30 day-old piglets (P < 0.05). In liver tissue, the expression level was significantly higher in the 35-day-old piglets than in other age groups (P < 0.01). In the stomach tissue, the expression level was significantly higher in 35-day-old piglets than in 18-day-old piglets (P < 0.05). LTßR expression in the lymph nodes was significantly higher in the resistant group than in the sensitive group (P < 0.01), but there was no significant difference in the other tissues (P > 0.05). These results indicate that 8 days after birth is a crucial stage in the formation of mesentery lymph nodes and immune barriers in pigs, and increased expression of LTßR may be beneficial for developing resistance to E. coli F18.
Assuntos
Infecções por Escherichia coli/veterinária , Receptor beta de Linfotoxina/biossíntese , Doenças dos Suínos/patologia , Suínos/genética , Animais , Peptídeos Catiônicos Antimicrobianos/biossíntese , Peptídeos Catiônicos Antimicrobianos/genética , Biomarcadores , Resistência à Doença , Duodeno/metabolismo , Escherichia coli/fisiologia , Infecções por Escherichia coli/genética , Expressão Gênica , Jejuno/metabolismo , Receptor beta de Linfotoxina/genética , Doenças dos Suínos/genética , Doenças dos Suínos/microbiologia , DesmameRESUMO
To assess the relationship between the expression of a(1,2)-fucosyltransferase (FUT1 and FUT2) genes and resistance to Escherichia coli F18 in weaned pigs, FUT1 and FUT2 expression levels in Large White, Meishan, and Sutai pigs (with resistance to E. coli F18) were determined using real-time PCR. The results revealed that FUT1 and FUT2 expression levels were higher in the liver, lungs, kidneys, stomach, duodenum, and jejunum than in the muscle and heart. Medium FUT2 expression levels were detected in the spleen, thymus, and lymph nodes. Intestinal FUT1 expression levels were higher in Sutai pigs than in Large White and Meishan pigs (P < 0.05). However, intestinal FUT2 expression levels were lower in Sutai pigs than in Large White and Meishan pigs (P < 0.05). FUT1 and FUT2 expression levels did not differ between Large White and Meishan pigs (P > 0.05). The results revealed that high FUT1 expression levels and low FUT2 expression levels in the intestines of Sutai pigs affected FUT1 and FUT2 enzymes, the synthesis of type 2 H and type 1 H antigens, and E. coli F18 adhesion. Moreover, low FUT2 expression levels conferred resistance to E. coli F18.
Assuntos
Resistência à Doença/genética , Infecções por Escherichia coli/veterinária , Fucosiltransferases/genética , Sus scrofa/metabolismo , Doenças dos Suínos/metabolismo , Animais , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/metabolismo , Fucosiltransferases/metabolismo , Expressão Gênica , Mucosa Intestinal/metabolismo , Especificidade de Órgãos , RNA Mensageiro , Sus scrofa/genética , Suínos , Doenças dos Suínos/genética , Galactosídeo 2-alfa-L-FucosiltransferaseRESUMO
The bactericidal/permeability-increasing protein (BPI) gene has been identified as a candidate gene for disease-resistance breeding. We evaluated whether polymorphisms in exons 4 and 10 of the BPI gene are associated with immune indices [interleukin-2 (IL-2), IL-4, IL-6, interferon-b (IFN-b), IL-10, and IL-12]. In this study, we identified one mutation (C522T) in the BPI exon 4 site and two mutations (A1060G and T1151G) in the BPI exon 10 site. Correlation analysis revealed that in the Sutai pig population, the effect of genotypes at the BPI exon 4 site on the level of IL-6 was significant (P < 0.05), with an effective genotype of CD; moreover, the effect of genotypes at the BPI exon 10 site on the level of IL-12 was significant (P < 0.05), and the effective genotype was AB. The optimal combined genotype was CD-AB, which was more effective regarding the IL-6 and IL-12 levels compared to the other combined genotypes (P < 0.05). These results indicate that single nucleotide polymorphisms and the combined genotypes of BPI exons 4 and 10 affect immune indices in Sutai pigs. Therefore, these genotypes should be further examined as effective markers for disease-resistant breeding of pigs.
Assuntos
Peptídeos Catiônicos Antimicrobianos/genética , Proteínas Sanguíneas/genética , Interleucina-2/metabolismo , Interleucina-6/metabolismo , Polimorfismo de Nucleotídeo Único , Suínos/imunologia , Animais , Resistência à Doença , Éxons , Polimorfismo de Fragmento de Restrição , Polimorfismo Conformacional de Fita Simples , Seleção Artificial , Suínos/genéticaRESUMO
The super antibiotic bactericidal/permeability-increasing (BPI) protein is a member of a new generation of proteins that have been implicated as endotoxin-neutralizing agents. In this study, recombinant porcine BPI protein was obtained by generating porcine BPI encoding prokaryotic, eukaryotic, and yeast expression vectors. Recombinant protein expression was detected in yeast GS115, Escherichia coli, and 293-6E cells by gel electrophoresis and Western blotting. Escherichia coli F18 is the primary Gram-negative bacteria in the gut and the main pathogen leading to diarrhea and edema dis-ease in weaning piglets. Therefore, E. coli F18-resistant and -sensitive Sutai piglets were used to test differential expression of BPI protein by Western blotting and to investigate the potential correlation between BPI protein expression and E. coli F18-susceptibility. Recombinant porcine BPI protein expression was not detected in the prokaryotic and yeast expression systems; however, soluble protein was detected in the eukaryotic expression system. These data indicate the strong bacterio-static action of the BPI protein and confirm the feasibility of obtaining large amounts of recombinant porcine BPI recombinant protein using this eukaryotic expression system. In addition, the BPI protein expres-sion levels in the E. coli F18-resistant group were significantly higher than those in the sensitive group, indicating that high BPI protein ex-pression is associated with resistance to E. coli F18. Our findings pro-vide a basis for further investigations into the development of a drug designed to confer resistance to E. coli F18 in weaning piglets.
Assuntos
Peptídeos Catiônicos Antimicrobianos/biossíntese , Proteínas Sanguíneas/biossíntese , Resistência à Doença/genética , Infecções por Escherichia coli/genética , Escherichia coli/genética , Animais , Peptídeos Catiônicos Antimicrobianos/genética , Proteínas Sanguíneas/genética , Suscetibilidade a Doenças/microbiologia , Suscetibilidade a Doenças/veterinária , Endotoxinas/genética , Endotoxinas/metabolismo , Escherichia coli/patogenicidade , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/patologia , Infecções por Escherichia coli/veterinária , Vetores Genéticos , Genótipo , Suínos , DesmameRESUMO
The transporter associated with antigen processing (TAP) transports peptides from the cytosol into the endoplasmic reticulum for subsequent loading onto the major histocompatibility complex (MHC) class I molecules. This study showed the dynamic changes in the TAP1 expression level in newborn to weaning piglets. Tissue expression profiles revealed that the TAP1 gene was expressed at low levels in all tissues, and the expression levels were relatively higher in the lung, spleen, lymph, and thymus; further, no significant difference was observed in the expression in each tissue among the 3 unweaned stages (8, 18, and 30 days). Nevertheless, the postweaning (35 days) expression levels in tissues, including the spleen, lung, lymph, duodenum, and jejunum were significantly higher than those in the unweaned stages. Furthermore, gene ontology and pathway analysis showed that TAP1 took part in 38 biological functions and 5 pathway processes, including ABC transporters and antigen processing and presentation. These analyses showed that the TAP1 gene, which was related to MHC I immune regulation, had a stable and low expression level in unweaned stages; however, its expression increased in the postweaning stages. The high expression level of TAP1 indicated that the gene might play an important role in Escherichia coli F18 resistance.
Assuntos
Transportadores de Cassetes de Ligação de ATP/biossíntese , Suínos/genética , Membro 2 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Escherichia coli/patogenicidade , Regulação da Expressão Gênica no Desenvolvimento , Antígenos de Histocompatibilidade Classe I/biossíntese , Suínos/crescimento & desenvolvimento , Suínos/microbiologia , Distribuição Tecidual , DesmameRESUMO
TLR4 is the main recognition receptor of bacterial lipopolysaccharides, which play an important role in innate and adaptive immunity. We used real-time PCR to analyze the tissue expression profile and differential expression of TLR4 in 4 pig populations (Escherichia coli F18-resistant Sutai, E. coli F18-sensitive Sutai, Large White, Meishan), in order to determine the role that the TLR4 gene plays in resistance to E. coli F18. We found that TLR4 expressed consistently in the 4 populations, with relatively high levels in immune tissues and the highest level in the lung. Generally, the expression of TLR4 in E. coli F18-sensitive individuals was the highest, followed by that in E. coli F18-resistant, Large White and Meishan. In the spleen, lung, kidney, lymph nodes, and thymus gland, TLR4 expression is significantly higher in the E. coli F18-sensitive than in the other 3 populations; there were no significant differences among E. coli F18-resistant Sutai, Large White, and Meishan. In addition, Gene Ontology and pathway analysis showed that TLR4 takes part in the inflammatory response. We found that porcine TLR4 has consistent tissue specificity in each breed, and downregulation of expression of the TLR4 gene is related to resistance to E. coli F18 in weaning piglets.
Assuntos
Resistência à Doença/genética , Infecções por Escherichia coli/genética , Suínos/genética , Receptor 4 Toll-Like/genética , Transcrição Gênica , Animais , Animais Endogâmicos , Regulação para Baixo , Infecções por Escherichia coli/imunologia , Estudos de Associação Genética , Imunidade Inata/genética , Especificidade de Órgãos , População/genética , Receptor 4 Toll-Like/metabolismoRESUMO
We compared and analyzed the expression of the BPI gene of Sutai piglets ranging from newborn to post-weaning days 8, 18, 30, and 35 by the real-time PCR method, in order to determine if it is involved in protection against disease caused by ETEC F18. There was a significant difference between 18 and 35-day expression in the jejunum. There were also significant differences between 35-day expression and expression at the other development stages in the duodenum. There were no significant differences in expression at 8, 18, and 30 days in the jejunum. We conclude that the porcine BPI gene may be the direct factor that resisted the ETEC F18 in weaning piglets, and that the resistance to ETEC F18 in weaning piglets is related to up-regulation of mRNA expression of BPI gene to a certain extent.