The effect of buffalo CD14 shRNA on the gene expression of TLR4 signal pathway in buffalo monocyte/macrophages

The role of macrophage subtypes and exosomes in immunomodulation

Macrophages are influential members of the innate immune system that can be reversibly polarized by different microenvironment signals. Cell polarization leads to a wide range of features, involving the migration, development, and organization of the cells. There is mounting evidence that macrophage polarization plays a key role in the initiation and development of a wide range of diseases. This study aims to give an overview of macrophage polarization, their different subtypes, and the importance of alternatively activated M2 macrophage and classically activated M1 macrophage in immune responses and pathological conditions. This review provides insight on the role of exosomes in M1/M2-like macrophage polarization and their potential as a promising therapeutic candidate.

Inhibition of Suv39H1 enhances transgenic IFNα-2b gene expression in Bcap-37 cells

The low expression of exogenous transferred gene limited the application of transgenic animal technology. Suppressor of variegation 3 ∼ 9 homolog 1(SUV39H1) gene plays a prominent role on repressive heterochromatin and transcription. To understand if exogenous transgenic gene expression was affected by SUV39H1 epigenetic modification, in this paper, the effective shRNA fragments targeting SUV39H1 gene were first screened, their roles on expression of exogenous transgenic genes were determined by using Bcap-37 cell line with stable expressing IFNα-2b gene as a model, the preliminary regulation mechanism of SUV39H1 gene was investigated. The results showed that the designed shRNA1/2 fragments of SUV39H1 gene had an obvious inhibition effect on the expression of SUV39H1 gene, reached 53.07 and 31.28%, respectively by qRT-PCR analysis. Compared with the control group, the expression of IFNα-2b gene in transgenic Bcap-37 cells infected with shRNA1 and 2 viruses significantly increased by 96.25 and 121.08%, respectively (p < 0.05). In addition, the expression of DNMT1, HDAC1 and G9a gene in the shRNA infected cells reduced significantly, and the expression of the HAT1 gene increased significantly (p < 0.05). The above results indicated that the expression of exogenous transgenic gene could be promoted by suppressing SUV39H1 gene at the cell level.

A proteomic profile of synoviocyte lesions microdissected from formalin-fixed paraffin-embedded synovial tissues of rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic inflammation of the synovial joints. Early intervention followed by early diagnosis can result in disease remission; however, both early stage diagnosis and provision of effective treatment have been impeded by the heterogeneity of RA, which details of pathological mechanism are unclear. Regardless of numerous investigations of RA by means of genomic and proteomic approaches, proteins interplaying in RA synovial tissues that contain various types of synoviocytes, are not yet sufficiently understood. Hence we have conducted an HPLC/mass spectrometry-based exploratory proteomic analysis focusing on synoviocyte lesions laser-microdissected (LMD) from formalin-fixed paraffin-embedded (FFPE) synovial tissues (RA, n = 15; OA, n = 5), where those of Osteoarthritis (OA) were used as the control.

Results

A total of 508 proteins were identified from the RA and OA groups. With the semi-quantitative comparisons, the spectral index (SpI), log2 protein ratio (R_SC) based on spectral counting, and statistical G-test, 98 proteins were found to be significant (pair-wise p < 0.05) to the RA synovial tissues. These include stromelysin-1 (MMP3), proteins S100-A8 and S100-A9, plastin-2, galectin-3, calreticulin, cathepsin Z, HLA-A, HLA-DRB1, ferritin, neutrophil defensin 1, CD14, MMP9 etc.

Conclusions

Our results confirmed the involvement of known RA biomarkers such as stromelysin-1 (MMP3) and proteins S100-A8 and S100-A9, and also that of leukocyte antigens such as HLA-DRB1. Network analyses of protein–protein interaction for those proteins significant to RA revealed a dominant participation of ribosome pathway (p = 5.91 × 10⁻⁴⁵), and, interestingly, the associations of the p53 signaling (p = 2.34 × 10⁻⁵). An involvement of proteins including CD14, S100-A8/S100-A9 seems to suggest an activation of the NF-kB/MAPK signaling pathway. Our strategy of laser-microdissected FFPE-tissue proteomic analysis in Rheumatoid Arthritis thus demonstrated its technical feasibility in profiling proteins expressed in synovial tissues, which may play important roles in the RA pathogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12014-015-9091-8) contains supplementary material, which is available to authorized users.

Establishment of a mouse model to express bovine CD14 short hairpin RNA

Background

Cluster of differentiation 14 (CD14) functions as a co-receptor for Toll-like receptor (TLR)-4 and myeloid differentiation factor (MD)-2 in detecting bacterial lipopolysaccharide. Together, these complexes promote the phagocytosis and digestion of Gram-negative bacteria, and initiate immune responses. To date, much of our understanding of CD14 function during Gram-negative bacterial inflammation comes from studies on mouse knockout models and cell transfection. To identify the effect of CD14 knockdown in this process in large livestock animals, we established a mouse model expressing bovine CD14 short hairpin (sh) RNA. shRNA fragments targeting bovine CD14 were screened by co-transfection in HEK 293 cells, and the most effective CD14 shRNA fragment was cloned into the eukaryotic expression vector pSilencer4.1-CD14 shRNA-IRES (internal ribosome entry site) and transferred into mouse zygotes by pronuclear microinjection to obtain transgenic mice. Expression of the enhanced green fluorescent protein (EGFP) reporter and genes related to the TLR4 signaling pathway was detected by immunohistochemistry (IHC) and quantitative polymerase chain reaction (PCR), respectively.

Results

One effective shRNA fragment (shRNA-674) targeting bovine CD14 was obtained, the sequence of which was shown to be conserved between cows, buffalos, sheep, and humans. Thirty-seven founder pups were obtained by pronuclear microinjection, of which three were positive for the transgene. In the F₁ generation, 11 of 33 mice (33%) were positive for the transgene as detected by PCR. IHC analysis detected exogenous EGFP expression in the liver, kidney, and spleen of transgenic F₁ mice, indicating that they were chimeric. The expression of endogenous CD14 mRNA in the heart, liver, spleen, lung, and kidney of transgenic F₁ mice was decreased 8-, 3-, 19.5-, 6-, and 11-fold, respectively. The expression patterns of endogenous MD-2, TLR4, interleukin-6 and tumor necrosis factor-α genes in transgenic mice also varied.

Conclusions

This study confirms that transgenic mice expressing bovine CD14 shRNA can be generated by pronuclear microinjection, and demonstrates inhibited endogenous mouse CD14 expression that alters gene expression related to the TLR4 signaling pathway.