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1.
Int J Mol Sci ; 22(18)2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34575880

RESUMO

Escherichia coli and Staphylococcus aureus are two common pathogenic microorganisms that cause mastitis in dairy cows. They can cause clinical mastitis and subclinical mastitis. In recent studies, lncRNAs have been found to play an important role in the immune responses triggered by microbial inducers. However, the actions of lncRNAs in bovine mastitis remain unclear. The purpose of this study was to investigate the effects of bovine mammary epithelial cell injuries induced by treatment with E. coli and S. aureus, and to explore the lncRNA profile on cell injuries. The lncRNA transcriptome analysis showed a total of 2597 lncRNAs. There were 2234 lncRNAs differentially expressed in the E. coli group and 2334 in the S. aureus group. Moreover, we found that the E. coli and S. aureus groups of maternal genes targeted signaling pathways with similar functions according to KEGG and GO analyses. Two lncRNA-miRNA-mRNA interaction networks were constructed in order to predict the potential molecular mechanisms of regulation in the cell injuries. We believe that this is the first report demonstrating the dysregulation of lncRNAs in cells upon E. coli and S. aureus infections, suggesting that they have the potential to become important diagnostic markers and to provide novel insights into controlling and preventing mastitis.

2.
J Gen Virol ; 102(8)2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34424158

RESUMO

Bovine astrovirus (BoAstV) belongs to genus Mamastravirus (MAstV). It can be detected in the faeces of both diarrhoeal and healthy calves. However, its prevalence, genetic diversity, and association with cattle diarrhoea are poorly understood. In this study, faecal samples of 87 diarrhoeal and 77 asymptomatic calves from 20 farms in 12 provinces were collected, and BoAstV was detected with reverse transcription-polymerase chain reaction (RT-PCR). The overall prevalence rate of this virus in diarrhoeal and asymptomatic calves was 55.17 % (95 % CI: 44.13, 65.85 %) and 36.36 % (95 % CI: 25.70, 48.12 %), respectively, indicating a correlation between BoAstV infection and calf diarrhoea (OR=2.15, P=0.024). BoAstV existed mainly in the form of co-infection (85.53 %) with one to five of nine viruses, and there was a strong positive correlation between BoAstV co-infection and calf diarrhoea (OR=2.83, P=0.004). Binary logistic regression analysis confirmed this correlation between BoAstV co-infection and calf diarrhoea (OR=2.41, P=0.038). The co-infection of BoAstV and bovine rotavirus (BRV) with or without other viruses accounted for 70.77 % of all the co-infection cases. The diarrhoea risk for the calves co-infected with BoAstV and BRV was 8.14-fold higher than that for the calves co-infected with BoAstV and other viruses (OR=8.14, P=0.001). Further, the co-infection of BoAstV/BRV/bovine kobuvirus (BKoV) might increase the risk of calf diarrhoea by 14.82-fold, compared with that of BoAstV and other viruses (OR=14.82, P <0.001). Then, nearly complete genomic sequences of nine BoAstV strains were assembled by using next-generation sequencing (NGS) method. Sequence alignment against known astrovirus (AstV) strains at the levels of both amino acids and nucleotides showed a high genetic diversity. Four genotypes were identified, including two known genotypes MAstV-28 (n=3) and MAstV-33 (n=2) and two novel genotypes designated tentatively as MAstV-34 (n=1) and MAstV-35 (n=3). In addition, seven out of nine BoAstV strains showed possible inter-genotype recombination and cross-species recombination. Therefore, our results increase the knowledge about the prevalence and the genetic evolution of BoAstV and provide evidence for the association between BoAstV infection and calf diarrhoea.


Assuntos
Infecções por Astroviridae , Doenças dos Bovinos , Coinfecção , Diarreia , Animais , Animais Recém-Nascidos/virologia , Infecções por Astroviridae/epidemiologia , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/virologia , China/epidemiologia , Coinfecção/epidemiologia , Coinfecção/veterinária , Coinfecção/virologia , Diarreia/epidemiologia , Diarreia/veterinária , Diarreia/virologia , Fezes/virologia , Prevalência
3.
J Vet Med Sci ; 83(8): 1248-1255, 2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34193721

RESUMO

Bovine mastitis, caused by Prototheca bovis, has received much attention worldwide. To investigate the status of P. bovis infection in dairy farms of Hubei, we collected 1,158 milk samples and 90 environmental samples from 14 dairy farms of Hubei, China. The isolates were identified with traditional biological methods and molecular biological techniques, and their pathogenicity was tested through mice infection experiments. Isolates from 57 milk and 20 environmental samples were identified as P. bovis. The mice infection tests proved that the isolated P. bovis could cause mastitis in mice, manifesting as severe red swelling of the mammary glands. Histopathological analysis of tissue sections showed necrosis and nodules lesions formed in the infected mice mammary tissue, accompanied by macrophage and neutrophil infiltration. These results suggested the existence of pathogenic P. bovis in dairy farms of the Hubei province, China, with brewer's grains and fresh feces possibly playing important roles in the spread of this disease.


Assuntos
Doenças dos Bovinos , Mastite Bovina , Mastite , Prototheca , Doenças dos Roedores , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Fazendas , Feminino , Mastite/veterinária , Mastite Bovina/epidemiologia , Camundongos , Leite
4.
Int J Mol Sci ; 22(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200743

RESUMO

Mastitis is a common disease in dairy cows that is mostly caused by E. coli, and it brings massive losses to the dairy industry. N6-Methyladenosine (m6A), a methylation at the N6 position of RNA adenine, is a type of modification strongly associated with many diseases. However, the role of m6A in mastitis has not been investigated. In this study, we used MeRIP-seq to sequence the RNA of bovine mammary epithelial cells treated with inactivated E. coli for 24 h. In this in vitro infection model, there were 16,691 m6A peaks within 7066 mRNA transcripts in the Con group and 10,029 peaks within 4891 transcripts in the E. coli group. Compared with the Con group, 474 mRNAs were hypermethylated and 2101 mRNAs were hypomethylated in the E. coli group. Biological function analyses revealed differential m6A-modified genes mainly enriched in the MAPK, NF-κB, and TGF-ß signaling pathways. In order to explore the relationship between m6A and mRNA expression, combined MeRIP-seq and mRNA-seq analyses revealed 212 genes with concomitant changes in the mRNA expression and m6A modification. This study is the first to present a map of RNA m6A modification in mastitis treated with E. coli, providing a basis for future research.


Assuntos
Adenosina/análogos & derivados , Metilação de DNA , Células Epiteliais/metabolismo , Infecções por Escherichia coli/veterinária , Regulação da Expressão Gênica , Glândulas Mamárias Animais/metabolismo , Mastite Bovina/genética , Adenosina/química , Animais , Bovinos , Células Epiteliais/imunologia , Células Epiteliais/microbiologia , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/imunologia , Feminino , Perfilação da Expressão Gênica , Glândulas Mamárias Animais/imunologia , Glândulas Mamárias Animais/microbiologia , Mastite Bovina/imunologia , Mastite Bovina/microbiologia
5.
ACS Sens ; 6(7): 2574-2583, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34156832

RESUMO

The use of color-encoded microspheres for a bead-based assay has attracted increasing attention for high-throughput multiplexed bioassays. A fluorescent PCC 6803@ZIF-8 composite was prepared as a bead-based assay platform by a self-assembled zeolitic imidazolate framework (ZIF-8) on the surface of inactivated PCC 6803 cells. The composite fluorescence owing to the presence of pigment proteins in PCC 6803 could be gradually bleached with the prolongation of the ultraviolet light irradiation time. The composites with different fluorescence intensities were therefore obtained as encoded microspheres for the multiplexed assay. ZIF-8 provides a stable, rigid shell and a large specific surface area for composites, which prevent the composites from breakage during use and storage, simplify the protein immobilization procedure, reduce non-specific adsorption, and enhance the detection sensitivity. The encoded composites were successfully used to detect multiple DNA insertion sequences of Mycobacterium tuberculosis. The presented strategy offers an innovative color-encoding method for high-throughput multiplexed bioassays without the need of using chemically synthesized fluorescent materials.


Assuntos
Zeolitas , Adsorção , Bioensaio , Biomarcadores , Microesferas
6.
Vaccine ; 39(30): 4184-4189, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-34127292

RESUMO

Infectious diseases can have a major impact on the profitability of the cattle industry. To determine the occurrence of bovine infectious diseases in China and the adoption of vaccination to control them, a national-wide questionnaire and focus group meeting were performed. The questionnaire was administered to 189 farmers including 93 dairy farmers, 80 beef cattle farmers and 16 yak farmers. Since it is compulsory to vaccinate cattle against foot and mouth disease, the coverage of vaccination to this disease was the highest (100% of dairy and yak farms and 92.5% of beef farms). However, the implementation of vaccination against other diseases was vastly different between cattle types with less than 50% of farms adopting vaccination (except brucellosis vaccine in yak farms). In a focus group meeting of 36 cattle experts on the key issues affecting the frequency of infectious diseases in cattle and the vaccination practices adopted on Chinese cattle farms, the lack of effective vaccines against single or multiple pathogens, a lack of tools for the early and correct diagnosis of disease, difficulties in licensing novel vaccines and diagnostic agents, low efficiency in disseminating knowledge on diseases and control products to producers were identified as key issues. In conclusion, except for FMD, the control of most infectious diseases of cattle in China requires improving. Development of improved control measures and diagnostic tests along with the development and implementation of educational material for producers on cattle diseases should be given priority.


Assuntos
Doenças dos Bovinos , Doenças Transmissíveis , Febre Aftosa , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/prevenção & controle , China/epidemiologia , Fazendas , Febre Aftosa/epidemiologia , Febre Aftosa/prevenção & controle , Vacinação/veterinária
7.
Biol Trace Elem Res ; 2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34185276

RESUMO

Mastitis caused by Staphylococcus aureus infection not only causes serious economic losses, but also affects human health. Se plays an important role in body immunity. However, the mechanisms by which Se regulates mastitis induced by S. aureus are still principally unknown. The purpose of this study is to investigate whether Se can inhibit mastitis induced by S. aureus through regulation of MerTK. Sixty BALB/c female mice were fed low, normal, or high Se concentrations for 7 weeks and then randomly divided into six groups (Se-Low Control group (LSN), Se-Normal Control group (NSN), Se-High Control group (HSN), Se-Low S. aureus group (LSS), Se-Normal S. aureus group (NSS), Se-High S. aureus group (HSS)). The regulation of Se on MerTK was detected via histopathological staining, western blot analysis, enzyme-linked immunosorbent assay, and qRT-PCR. With increased selenium concentrations, the levels of IL-1ß, IL-6, and TNF-α decreased, while the phosphorylation levels of MerTK, PI3K, AKT, and mTOR increased. Therefore, this study showed that Se could alleviate S. aureus mastitis by activating MerTK and PI3K/AKT/mTOR pathway.

8.
ACS Infect Dis ; 7(4): 800-810, 2021 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-33705114

RESUMO

The modulation of the interaction between macrophages and Mycobacterium tuberculosis (M.tb) through microRNA during M.tb infection is increasingly capturing the attention of researchers. However, the potential role of microRNA-18b-5p (miR-18b) is not elucidated yet. In this study, miR-18b was found to be downregulated in M.tb-infected macrophage cell lines (THP-1 and RAW264.7) in time- and dose-dependent manners. Furthermore, when the miR-18b mimic and inhibitor and small interfering RNA hypoxia-inducible factor 1α (si-HIF-1α) were transfected into the macrophages separately or in combination, it was found that miR-18b targeted hypoxia-inducible factor 1α (HIF-1α). During M.tb infection, the decrease in the expression of miR-18b facilitated HIF-1α expression, which led to the increased production of pro-inflammatory cytokines, such as IL-6, resulting in decreased bacterial survival in the host cells. Moreover, the phosphorylation of p38 MAPK and NF-κB p65 was activated by the miR-18b inhibitor. Our findings expand the current understanding of the M.tb-cell interaction mechanism and provide a potential target to control M.tb infection.


Assuntos
Macrófagos , MicroRNAs , Mycobacterium tuberculosis , Animais , Citocinas/genética , Citocinas/metabolismo , Regulação para Baixo , Humanos , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , MicroRNAs/genética , Células RAW 264.7 , Células THP-1
9.
Front Immunol ; 12: 619362, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33659004

RESUMO

Mycoplasma bovis causes important diseases and great losses on feedlots and dairy farms. However, there are only a few measures to control M. bovis-related diseases. As in other mycoplasma species, this is predominantly because the virulence related factors of this pathogen are largely unknown. Therefore, in this study, we aimed to identify novel virulence-related factors among the secreted proteins of M. bovis. Using bioinformatic tools to analyze its secreted proteins, we preliminarily predicted 39 secreted lipoproteins, and then selected 11 of them for confirmation based on SignalP scores >0.6 or SceP scores >0.8 and conserved domains. These 11 genes were cloned after gene modification based on the codon bias of Escherichia coli and expressed. Mouse antiserum to each recombinant protein was developed. A western blotting assay with these antisera confirmed that MbovP280 and MbovP475 are strongly expressed and secreted proteins, but only MbovP280 significantly reduced the viability of bovine macrophages (BoMac). In further experiments, MbovP280 induced the apoptosis of BoMac treated with both live M. bovis and MbovP280 protein. The conserved coiled-coil domain of MbovP280 at amino acids 210-269 is essential for its induction of apoptosis. Further, immunoprecipitation, mass spectrometry, and coimmunoprecipitation assays identified the anti-apoptosis regulator αB-crystallin (CRYAB) as an MbovP280-binding ligand. An αß-crystallin knockout cell line BoMac-cryab-, Mbov0280-knockout M. bovis strain T9.297, and its complemented M. bovis strain CT9.297 were constructed and the apoptosis of BoMac-cryab- induced by these strains was compared. The results confirmed that CRYAB is critical for MbovP280 function as an apoptosis inducer in BoMac. In conclusion, in this study, we identified MbovP280 as a novel secreted protein of M. bovis that induces the apoptosis of BoMac via its coiled-coil domain and cellular ligand CRYAB. These findings extend our understanding of the virulence mechanism of mycoplasmal species.


Assuntos
Apoptose , Proteínas de Bactérias/metabolismo , Macrófagos/metabolismo , Infecções por Mycoplasma/genética , Infecções por Mycoplasma/microbiologia , Mycoplasma bovis/fisiologia , Animais , Apoptose/imunologia , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/farmacologia , Bovinos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Genoma Bacteriano , Humanos , Ligantes , Macrófagos/imunologia , Camundongos , Modelos Biológicos , Infecções por Mycoplasma/imunologia , Infecções por Mycoplasma/metabolismo
10.
Sci Rep ; 11(1): 5208, 2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33664426

RESUMO

Feline infectious peritonitis (FIP) is a systemic, potentially fatal viral disease. The objectives of this study were to review clinical and laboratory features and treatment of cats highly suspected of FIP in Wuhan, China. The clinical records of 127 cats highly suspected of FIP were reviewed for history, clinical signs, physical findings, and diagnostic test results. Sex, neutering status, breed, age, and month of onset of disease were compared with the characteristics of the clinic population. Age and neutering status were significantly correlated with FIP-suspicion. Sex, breed and onset month were not associated with FIP. There were many more FIP-suspected cases in cats in young cats or male intact cats. Effusion was observed in 85.8% of the FIP-suspected cats. Increased serum amyloid A (SAA) and lymphopenia were common laboratory abnormalities in the FIP cases. Furthermore, 91.7% of the cats highly suspected of FIP had an albumin/globulin (A/G) ratio < 0.6, while 85.3% had an A/G ratio < 0.5. The mortality rate for FIP-suspected cats was 67%, and six submitted cases were confirmed by FIP-specific immunohistochemistry. Of the 30 cats treated with GS-441524 and/or GC376, 29 were clinically cured. The study highlights the diverse range of clinical manifestations by clinicians in diagnosing this potentially fatal disease. A/G ratio and SAA were of higher diagnostic value. GS-441524 and GC376 were efficient for the treatment of FIP-suspected cats.

11.
Transbound Emerg Dis ; 2021 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-33550715

RESUMO

The novel coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in an unprecedented public health crisis and economic losses. Although several cases of cats and dogs infected with SARS-CoV-2 have been reported during this outbreak, the prevalence of SARS-CoV-2 in dog and its transmission among other companion animals are still unknown. Here, we report an extensive serological study of SARS-CoV-2 infection in dogs in Wuhan and analyse the infection rates at different stages of the pandemic outbreak. A total of 946 dogs serum samples were collected from Wuhan, of which 36 samples were obtained prior to the pandemic outbreak. Indirect enzyme-linked immunosorbent assay (ELISA) showed that 16 sera collected during the outbreak were detected as positive through the receptor-binding domain (RBD) of SARS-CoV-2. Of these 16 sera, 10 exhibited measurable SARS-CoV-2-specific neutralizing antibodies whose titres ranged from 1/20 to 1/180. No serological cross-reactivity was detected between SARS-CoV-2 and canine coronavirus (CCV). Furthermore, with the effective control of the outbreak, a decrease in the SARS-CoV-2 seropositive dog number was observed. Our results suggest that SARS-CoV-2 has infected companion dogs during the outbreak, and that COVID-19 patient families have a higher risk of dog infection. Our findings deepen our understanding of the infection of SARS-CoV-2 in dogs and provide an important reference for prevention of COVID-19.

12.
Infect Genet Evol ; 89: 104715, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33434703

RESUMO

Rotaviruses (RVs) account for severe diarrhea in children and young animals globally. In the current study, the fecal samples of diarrheic calves from a beef farm in Inner Mongolia were screened for RVA by ELISA and RT-PCR, followed by culture of three positive RVA samples in the MA-104 cell line. After 10 blind passages, cytopathic effects (CPE) appeared as detachment, granulation, and clustering of the inoculated cells. The virus isolates were identified by RT-PCR (VP6 gene RVA) and ESI-LC-MS/MS for whole protein sequencing. The protein sequences demonstrated the presence of two strains from species A rotavirus and one RVB strain; RVA/Cow-tc/CHN/35333/2019/G6P[5] was mixed with one RVB strain (RVB/Cow-tc/CHN/35334/2019/G5P[3]) in two samples, and RVA/Cow-tc/CHN/10927/2019/G8P[7] was found in one sample. They are of genotype constellations (G6-P[5]-I2-R2-C2-M2-A3-N2-T6-E2-H3), (G8-P[7]-I5-R1-C1- M2-A1-N1-T1-E1-H1), and (G5-P[3]-I3-R5-C5-A5-N4-H5), respectively. Besides, phylogenetic analysis of the obtained sequences demonstrated viral evolution.

13.
J Biomed Mater Res A ; 109(5): 615-626, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32608169

RESUMO

Surface modification techniques are often used to enhance the properties of Ti-based materials as hard-tissue replacements. While the microstructure of the coating and the quality of the interface between the substrate and coating are essential to evaluate the reliability and applicability of the surface modification. In this study, both a hydroxyapatite (HA) coating and a collagen-hydroxyapatite (Col-HA) composite coating were deposited onto a Ti-6Al-4V substrate using a biomimetic coating process. Importantly, a gradient cross-sectional structure with a porous coating toward the surface, while a dense layer adjacent to the interface between the coating and substrate was observed in three-dimensional (3D) from both the HA and Col-HA coatings via a dual-beam focused ion beam-scanning electron microscope (FIB-SEM). Moreover, the pore distributions within the entire coatings were reconstructed in 3D using Avizo, and the pores size distributions along the coating depth were calculated using RStudio. By evaluating the mechanical property and biocompatibility of these materials and closely observing the cross-sectional cell-coating-substrate interfaces using FIB-SEM, it was revealed that the porous surface created by both coatings well supports osteoblast cell adhesion while the dense inner layer facilitates a good bonding between the coating and the substrate. Although the mechanical property of the coating decreased with the addition of collagen, it is still strong enough for implant handling and the biocompatibility was promoted.

14.
Pathogens ; 9(9)2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32967149

RESUMO

Mycoplasma bovis is a major pathogen, responsible for bovine respiratory diseases worldwide. The present lack of effective control measures leaves cattle owners at considerable perpetual risk of M. bovis outbreaks. In this study, we identified M. bovis secreted immunogenic proteins in silico as potential candidates for novel diagnostic agents and vaccines. We used immunoinformatics to analyze 438 M. bovis proteins previously identified with a label-free proteomics analysis of virulent M. bovis HB0801 (P1) and its attenuated P150 strains. The subcellular localization of these proteins was preliminarily screened and 59 proteins were found to be secreted extracellular proteins. Twenty-seven of these proteins contained a large number of predictive T-cell epitopes presented by major histocompatibility complex (MHC) class I and II molecules. Twenty-two of these 27 proteins had a high number of conformational B-cell epitopes, predicted from the corresponding 3D structural templates, including one unique to P1, two unique to P150, and 19 common to both strains. Five proteins were selected for further validation, and two of these, MbovP274 and MbovP570, were successfully expressed and purified. Both were confirmed to be secretory and highly immunogenic proteins that induced a mouse antibody response, reacted with cattle serum positive for M. bovis infection, and significantly increased the production of interleukin 8 (IL-8), IL-12 and interferon γ (IFN-γ) during the secretion of these three cytokines by both M. bovis mutants of these genes. These results should be useful in the development of novel immunological agents against M. bovis infection.

15.
Microb Pathog ; 148: 104456, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32810556

RESUMO

Tripartite motif 25 (TRIM25) is a TRIM family member which is involved in innate immunity. However, its role in the modulation of host defense against Mycobacterium tuberculosis (M.tb) infection has not been investigated. Therefore, this study aimed to demonstrate the significance of TRIM25 in the regulation of macrophage responses to M.tb infection. TRIM25 was found to be significantly overexpressed (3.476-fold) in peripheral blood mononuclear cells (PBMCs) of 67 patients with pulmonary tuberculosis compared with 48 healthy controls. TRIM25 expression was enhanced following M.tb infection of RAW264.7 cells, a macrophage cell line. Overexpression of TRIM25 in M.tb-infected RAW264.7 cells led to a significant increase in phosphorylated p38 levels; however, the production of IL-6, IL-1ß, and TNF-α were significantly reduced. Finally, M.tb intracellular survival increased by 90% at 12 h post-infection (PI) (p < 0.01). To validate the previous results, TRIM25 levels in M.tb-infected RAW264.7 macrophages were down-regulated using small interfering RNA (siRNA). Therefore, it was concluded that TRIM25 promotes intracellular survival of M.tb in RAW264.7 cells, likely by enhancing p38 pathways and thereby inhibiting the production of proinflammatory cytokines. These results contribute to the further understanding of the host defense against M.tb infection.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Leucócitos Mononucleares , Transdução de Sinais , Fatores de Transcrição/genética , Proteínas com Motivo Tripartido/genética , Ubiquitina-Proteína Ligases , Regulação para Cima
16.
Animals (Basel) ; 10(8)2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32824421

RESUMO

The current study evaluated the influence of a multi-carbohydrase and phytase complex (MCPC) on the ileal and total tract digestibility of nutrients in growing pigs. A total of eight barrows (initial BW = 30.7 ± 1.1 kg) were surgically fitted with a T-cannula at the distal ileum and randomly allotted to four groups. The experiment was conducted according to a 4 × 4 Latin square design, each period lasting 10 days. Pigs were fed four experimental diets, which consisted of two basal diets (BD1, low phytate; BD2, high phytate) with or without MCPC containing at least 1800 U xylanase, 6600 U α-arabinofuranosidase, 1244 U ß-glucanase, and 1000 U phytase per/kg corn-soybean meal with 15% corn distillers based diet. The high phytate diet reduced (p < 0.05) the apparent ileal digestibility (AID) of crude protein by 1.4% and the apparent total tract digestibility (ATTD) of organic matter, crude protein, and gross energy by 1.7, 2.3, and 1.9%, respectively, and tended to decrease (p = 0.10) the ATTD of Ca by 17.3%, relative to the low phytate diet. The dietary supplementation of the MCPC increased (p < 0.05) the AID of phosphorus (P) and calcium (Ca) by 34.2% and 31.1% for BD1 and 26.7% and 41.3% for BD2, respectively, and increased (p < 0.05) ATTD of crude fat, P, and Ca by 1.4%, 45.6%, and 9.6% for BD1 and 3.1%, 66.0%, and 52.7% for BD2, respectively. The MCPC supplementation did not significantly increase the AID and (or) ATTD of crude protein, organic matter, and starch. In conclusion, the dietary supplementation of the MCPC could improve the AID of P and Ca and the ATTD of crude fat, P, and Ca.

17.
Int Immunopharmacol ; 86: 106697, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32585608

RESUMO

Mastitis is one of the most common diseases among dairy cows. There is still much debate worldwide as to whether antibiotic therapy should be given to dairy cows, or if natural products should be taken as a substitute for antibacterial therapy. As the antibiotic treatment leads to the bacterial resistance and drug residue in milk, introducing natural products for mastitis is becoming a trend. This study investigates the mechanisms of the protective effects of the natural product gambogic acid (GA) in lipopolysaccharide (LPS)-induced mastitis. For in vitro treatments, it was found that GA reduced IL-6, TNF-α, and IL-1ß levels by inhibiting the phosphorylation of proteins in the nuclear factor κB (NF-κB) and the mitogen-activated protein kinase (MAPK) pathway. GA also maintained a stable membrane mitochondrial potential and inhibited the overproduction of reactive oxygen species, which protected the cells from apoptosis. On the other hand, in vivo treatments with GA were found to reduce pathological symptoms markedly, and protected the blood-milk barrier from damage induced by LPS. The results demonstrate that GA plays a vital role in suppressing inflammation, alleviating the apoptosis effect, and protecting the blood-milk barrier in mastitis induced by LPS. Thus, these results suggest that the natural product GA plays a potential role in mastitis treatment.


Assuntos
Anti-Inflamatórios/farmacologia , Apoptose/efeitos dos fármacos , Glândulas Mamárias Animais/efeitos dos fármacos , Mastite/tratamento farmacológico , Xantonas/farmacologia , Animais , Anti-Inflamatórios/uso terapêutico , Caspase 3/metabolismo , Caspase 9/metabolismo , Linhagem Celular , Citocinas/metabolismo , Modelos Animais de Doenças , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/imunologia , Feminino , Inflamação/tratamento farmacológico , Lipopolissacarídeos/toxicidade , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Glândulas Mamárias Animais/imunologia , Glândulas Mamárias Animais/patologia , Glândulas Mamárias Animais/ultraestrutura , Mastite/induzido quimicamente , Mastite/imunologia , Mastite/patologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Subunidade p50 de NF-kappa B/metabolismo , Fosforilação/efeitos dos fármacos , Gravidez , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Xantonas/uso terapêutico
18.
PLoS Pathog ; 16(6): e1008661, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32598377

RESUMO

Mycoplasmas are host-restricted prokaryotes with a nearly minimal genome. To overcome their metabolic limitations, these wall-less bacteria establish intimate interactions with epithelial cells at mucosal surfaces. The alarming rate of antimicrobial resistance among pathogenic species is of particular concern in the medical and veterinary fields. Taking advantage of the reduced mycoplasma genome, random transposon mutagenesis was combined with high-throughput screening in order to identify key determinants of mycoplasma survival in the host-cell environment and potential targets for drug development. With the use of the ruminant pathogen Mycoplasma bovis as a model, three phosphodiesterases of the DHH superfamily were identified as essential for the proliferation of this species under cell culture conditions, while dispensable for axenic growth. Despite a similar domain architecture, recombinant Mbov_0327 and Mbov_0328 products displayed different substrate specificities. While rMbovP328 protein exhibited activity towards cyclic dinucleotides and nanoRNAs, rMbovP327 protein was only able to degrade nanoRNAs. The Mbov_0276 product was identified as a member of the membrane-associated GdpP family of phosphodiesterases that was found to participate in cyclic dinucleotide and nanoRNA degradation, an activity which might therefore be redundant in the genome-reduced M. bovis. Remarkably, all these enzymes were able to convert their substrates into mononucleotides, and medium supplementation with nucleoside monophosphates or nucleosides fully restored the capacity of a Mbov_0328/0327 knock-out mutant to grow under cell culture conditions. Since mycoplasmas are unable to synthesize DNA/RNA precursors de novo, cyclic dinucleotide and nanoRNA degradation are likely contributing to the survival of M. bovis by securing the recycling of purines and pyrimidines. These results point toward proteins of the DHH superfamily as promising targets for the development of new antimicrobials against multidrug-resistant pathogenic mycoplasma species.


Assuntos
Proteínas de Bactérias/metabolismo , Mycoplasma bovis/enzimologia , Pirofosfatases/metabolismo , Ribonucleases/metabolismo , Animais , Proteínas de Bactérias/genética , Linhagem Celular , Camundongos , Camundongos Endogâmicos BALB C , Mycoplasma bovis/genética , Pirofosfatases/genética , Ribonucleases/genética
19.
Artigo em Inglês | MEDLINE | ID: mdl-32257967

RESUMO

Mycobacterium tuberculosis (M. tb) can survive in the hostile microenvironment of cells by escaping host surveillance, but the molecular mechanisms are far from being fully understood. MicroRNAs might be involved in regulation of this intracellular process. By RNAseq of M. tb-infected PMA-differentiated THP-1 macrophages, we previously discovered down-regulation of miR-378d during M. tb infection. This study aimed to investigate the roles of miR-378d in M. tb infection of THP-1 cells by using a miR-378d mimic and inhibitor. First, M. tb infection was confirmed to decrease miR-378d expression in THP-1 and Raw 264.7 macrophages. Then, it was demonstrated that miR-378d mimic promoted, while its inhibitor decreased, M. tb survival in THP-1 cells. Further, the miR-378d mimic suppressed, while its inhibitor enhanced the protein production of IL-1ß, TNF-α, IL-6, and Rab10 expression. By using siRNA of Rab10 (siRab10) to knock-down the Rab10 gene in THP-1 with or without miR-378d inhibitor transfection, Rab10 was determined to be a miR-378d target during M. tb infection. In addition, a dual luciferase reporter assay with the Rab10 wild-type sequence and mutant for miR-378d binding sites confirmed Rab10 as the target of miR-378d associated with M. tb infection. The involvement of four signal pathways NF-κB, P38, JNK, and ERK in miR-378d regulation was determined by detecting the effect of their respective inhibitors on miR-378d expression, and miR-378d inhibitor on activation of these four signal pathways. As a result, activation of the NF-κB signaling pathway was associated with the down-regulation of miR-378d. In conclusion, during M. tb infection of macrophages, miR-378d was down-regulated and functioned on decreasing M. tb intracellular survival by targeting Rab10 and the process was regulated by activation of the NF-κB and induction of pro-inflammatory cytokines IL-1ß, TNF-α, IL-6. These findings shed light on further understanding the defense mechanisms in macrophages against M. tb infection.


Assuntos
MicroRNAs , Mycobacterium tuberculosis , Citocinas/metabolismo , Regulação para Baixo , Macrófagos/metabolismo , MicroRNAs/genética , Mycobacterium tuberculosis/metabolismo , NF-kappa B/metabolismo
20.
Microorganisms ; 8(4)2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32316659

RESUMO

: Mycobacterium tuberculosis is considered a successful pathogen with multiple strategies to undermine host immunity. The YrbE3A is encoded by Rv1964 within the RD15 region present in the genome of Mtb, but missing in M. bovis, M. bovis BCG (Pasteur) strain, and M. smegmatis (Ms). However, little is known about its function. In this study, the YrbE3A gene was cloned into pMV261 and expressed in Ms and BCG, while the strains with the vector served as the controls. The YrbE3A was expressed on the mycobacterial membrane, and the purified protein could stimulate RAW264.7 cells to produce IL-6. Furthermore, the effect of the recombinant strains on cytokine secretion by RAW264.7 was confirmed, which varied with the host strains. Ms_YrbE3A increased significantly higher levels of TNF-α and IL-6 than did Ms_vec, while BCG_YrbE3A enhanced higher TNF-α than BCG_vec. The pathways associated with NF-κB p65 and MAPK p38/JNK, other than Erk1/2, regulated this process. In addition, mice were infected with Ms_YrbE3A and Ms-vec and were kinetically examined. Compared to Ms-vec, Ms_YrbE3A induced more serious inflammatory damage, higher levels of TNF-α and IL-6, higher numbers of lymphocytes, neutrophils, and monocytes in a time-dependent way, but lower lung bacterial load in lung. These findings may contribute to a better understanding of Mtb pathogenesis.

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