The interaction of MMP-2/B7-H3 in human osteoporosis.

The immune costimulatory molecule B7-H3 has been shown to be involved in the regulation of murine bone formation. However, the role of B7-H3 in bone metabolic diseases remains unknown. In our study, matrix metalloproteinase 2 (MMP-2) and soluble B7-H3 (sB7-H3) were found to be correlatively up-regulated in the sera of osteoporosis patients. Furthermore, our results showed that MG63 cells treated with MMP-2 inhibitors produced lower amounts of sB7-H3 while cells with recombinant MMP-2 had an increased membrane B7-H3 (mB7-H3) shedding. Therefore, elevated MMP-2 levels resulted in an elevation of serum sB7-H3 and reduction of osteoblastic mB7-H3. B7-H3 knockdown in MG63 cells significantly decreased osteoblastic markers and substantially decreased the number of mineralized nodules after 21days. Thus, B7-H3-deficient MG63 cells exhibited impaired bone formation. These results suggest that mB7-H3 is required for the later phases of osteoblast differentiation and that MMP-2/B7-H3 plays a negative regulatory role in osteoporosis.

Evaluation of three sample preparation methods for the identification of clinical strains by using two MALDI-TOF MS systems.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has revolutionized the microbial identification, especially in the clinical microbiology laboratories. However, although numerous studies on the identification of microorganisms by MALDI-TOF MS have been reported previously, few studies focused on the effect of pretreatment on identification. Due to the sensitivity of MALDI-TOF MS, different preparation methods will lead to changes in microbial protein fingerprints. In this study, for evaluating a more appropriate preparation method for the clinical microbiology identification, we analyzed the performance of three sample preparation methods on two different MALDI-TOF MS systems. A total of 321 clinical isolates, 127 species, were employed in the comparative study of three different sample preparation methods including the direct colony transfer method (DCTM), the on-target extraction method (OTEM), and the in-tube extraction method (ITEM) compatible with MALDI-TOF MS. All isolates were tested on the Microflex LT and Autof ms1000 devices. The spectra were analyzed using the Bruker biotyper and the Autof ms1000 systems. The results were confirmed by 16/18S rRNA sequencing. Results reveal that the accuracies of isolates identification by Bruker biotyper successfully identified 83.8%, 96.0%, and 95.3% after performing the DCTM, OTEM, and ITEM, respectively, while the Autof ms1000 identified 97.5%, 100%, and 99.7%. These data suggested that the identification rates are comparable among the three preparation methods using the Autof ms1000 and Bruker microflex LT systems but the OTEM is more suitable and necessary for clinical application, owing to its key advantages of simplicity and accuracy.

Identification of antibiotic resistance genes in the multidrug-resistant Acinetobacter baumannii strain, MDR-SHH02, using whole-genome sequencing.

This study aimed to investigate antibiotic resistance genes in the multidrug-resistant (MDR) Acinetobacter baumannii (A. baumanii) strain, MDR-SHH02, using whole­genome sequencing (WGS). The antibiotic resistance of MDR-SHH02 isolated from a patient with breast cancer to 19 types of antibiotics was determined using the Kirby­Bauer method. WGS of MDR-SHH02 was then performed. Following quality control and transcriptome assembly, functional annotation of genes was conducted, and the phylogenetic tree of MDR-SHH02, along with another 5 A. baumanii species and 2 Acinetobacter species, was constructed using PHYLIP 3.695 and FigTree v1.4.2. Furthermore, pathogenicity islands (PAIs) were predicted by the pathogenicity island database. Potential antibiotic resistance genes in MDR-SHH02 were predicted based on the information in the Antibiotic Resistance Genes Database (ARDB). MDR-SHH02 was found to be resistant to all of the tested antibiotics. The total draft genome length of MDR-SHH02 was 4,003,808 bp. There were 74.25% of coding sequences to be annotated into 21 of the Clusters of Orthologous Groups (COGs) of protein terms, such as 'transcription' and 'amino acid transport and metabolism'. Furthermore, there were 45 PAIs homologous to the sequence MDRSHH02000806. Additionally, a total of 12 gene sequences in MDR-SHH02 were highly similar to the sequences of antibiotic resistance genes in ARDB, including genes encoding aminoglycoside­modifying enzymes [e.g., aac(3)-Ia, ant(2'')­Ia, aph33ib and aph(3')-Ia], ß-lactamase genes (bl2b_tem and bl2b_tem1), sulfonamide-resistant dihydropteroate synthase genes (sul1 and sul2), catb3 and tetb. These results suggest that numerous genes mediate resistance to various antibiotics in MDR-SHH02, and provide a clinical guidance for the personalized therapy of A. baumannii-infected patients.

Reduced serum B7-H3 levels in patients with ankylosing spondylitis.

This study aimed to investigate molecule B7-H3 expression profiles of patients with ankylosing spondylitis (AS) and the clinical significance of B7-H3 in the pathogenesis of AS. Serum B7-H3 levels were measured by ELISA in patients with AS and healthy controls. The expression of B7-H3 protein and mRNA on CD14+ monocytes of peripheral blood mononuclear cells (PBMCs) and serum levels of T cell-associated cytokines were also analyzed. The serum B7-H3 levels in AS patients were significantly lower than in healthy controls. The expression of B7-H3 protein and mRNA on CD14+ monocytes of PBMCs and serum levels of TNF-α, IL-6, and IL-17A in AS patients were significantly higher than in controls. The reduced serum B7-H3 level was highly negatively correlated with AS Disease Activity Score (ASDAS), TNF-α, and IL-17A. Upregulated B7-H3 protein may play a role in the pathogenesis of AS by binding its receptor on T cells.

[IL-33 enhances cytokine secretion and killing function of peripheral blood mononuclear cells in vitro].

OBJECTIVE: To investigate whether interleukin 33 (IL-33) can enhance cytokine secretion and killing activity of peripheral blood mononuclear cells (PBMCs) in vitro. METHODS: PBMCs were harvested from healthy volunteers and stimulated with different combination of cytokines (CD3 mAb/CD28 mAb/IL-2, CD3 mAb/CD28 mAb/IL-2/IL-12, CD3 mAb/CD28 mAb/IL-2/IL-12/IL-33) in vitro. The cells of each group were collected after 72 hours. Total RNA were extracted and assayed by real-time quantitative PCR (qRT-PCR) for the levels of interferon γ (IFN-γ) and granzyme B. The cytotoxic activity of the cells targeting A549 human lung adenocarcinoma cells was detected by CCK-8 assay. The levels of programmed death-1 (PD-1) and IFN-γ were determined by flow cytometry. RESULTS: There was no significant difference in cell morphology observed by microscope among the three groups. In the cells stimulated in the presence of IL-33, the levels of IFN-γ and granzyme B mRNAs were significantly elevated, cell killing ability was strengthened, and the level of IFN-γ increased significantly, PD-1 level decreased when compared with the other two groups. CONCLUSION: IL-33 might enhance the function of PBMCs and then promote adaptive anti-tumor immune response.