Effect of MT2A on apoptosis and proliferation in HL60 cells.

Although accumulating evidence has revealed that metallothioneins (MTs) and its family member MT2A are strongly linked to the risk of various solid tumors, researches on the occurrence and development of acute myeloid leukemia (AML) have rarely been investigated. Here, we constructed a lentiviral vector with MT2A over-expression and the interfering plasmids with MT2A expression inhibition to study the influence of MT2A on the bioactivities of HL60 cells. After cells were infected with a lentiviral vector containing the MT2A gene, both transcription and translation levels of MT2A were significantly increased in the over-expressed group in comparison with control groups. In vitro experiments, all results demonstrated that cell reproductive capacity was inhibited, but cell apoptosis rate was significantly increased. Together, the expression of apoptosis-related protein Bcl2 was remarkably reduced, while a high expression level of Bax protein was detected. Further experiments revealed that up-regulation of MT2A induced cell apoptosis and promoted G2/M phase arrest. The mechanism may be associated with down-regulated p-IκB-α and cyclinD1 expression and up-regulated IκB-α expression in the nuclear factor-kappaB (NF-κB) pathway. On the contrary, MT2A expression was down-regulated by interfering plasmids. We found that cell proliferative potential was notably increased in the interfering group compared with the negative and untreated group. What's more, MT2A may be closely related to AML cell proliferation and function via the NF-κB signal pathway.

Draft genome sequence analysis of a high carbapenem-resistant Klebsiella quasipneumoniae subsp. quasipneumoniae strain isolated from an HIV-positive patient with pneumonia.

OBJECTIVES: The rapid spread of Klebsiella spp. is recognised as a major threat to public health owing to a rise in the number both of healthcare- and community-acquired infections. Here we report the draft genome sequence of a high carbapenem-resistant Klebsiella quasipneumoniae subsp. quasipneumoniae strain (Cln185) isolated from a human immunodeficiency virus (HIV)-positive patient with pneumonia. METHODS: Classical microbiological methods were applied to isolate and identify the strain. Genomic DNA was sequenced using an Illumina HiSeq platform and the reads were de novo assembled into contigs using CLC Genomics Workbench. The assembled contigs was annotated and whole-genome sequencing (WGS) was performed. RESULTS: WGS analysis revealed that the genome comprised a circular chromosome of 5 406 774bp with a GC content of 57.73%. Three important antimicrobial resistance genes (blaIMP-38, blaOKP-B-6 and blaDHA-1) were detected. In addition, genes conferring resistance to aminoglycosides, ß-lactams, fluoroquinolones and tetracycline were also identified. CONCLUSION: The draft genome sequence reported here will lay the foundation for future research on antimicrobial resistance and pathogenic mechanisms in K. quasipneumoniae subsp. quasipneumoniae and also will promote comparative analysis with genomic features among different sources of clinically important multidrug-resistant strains.

Extracorporeal cardiac shock wave therapy ameliorates myocardial fibrosis by decreasing the amount of fibrocytes after acute myocardial infarction in pigs.

OBJECTIVES: Extracorporeal shock wave (SW) therapy ameliorates cardiac remodeling after acute myocardial infarction (AMI). However, it remains to be examined whether and how SW therapy ameliorates myocardial fibrosis after AMI. Fibrocytes are associated with myocardial fibrosis. Thus, we examined whether SW therapy ameliorates myocardial fibrosis and whether fibrocytes are associated after AMI in pigs. MATERIALS AND METHODS: AMI was created by coronary embolism. Twenty-five pigs were divided into three groups: AMI+SW group (AMI with SW therapy, n=15), AMI group (without SW therapy, n=5), and sham+SW group (SW therapy without AMI, n=5). The collagen area fraction was examined by Masson's trichrome staining. The presence of fibrocytes was identified by immunofluorescence and confocal microscopy. The location of CXCL12 was examined by immunohistochemistry. RESULTS: Compared with the AMI group, the AMI+SW group showed significantly ameliorated myocardial fibrosis in terms of collagen area fraction (27.21±8.13 vs. 10.13±4.96, P<0.05) and reduced fibrocytes (CD34/α-smooth muscle actin: 35.40±11.72 vs. 12.27±7.71, P<0.05; CXCR4/α-smooth muscle actin: 40.80±8.96 vs. 16.54±6.38, P<0.05). There were positive correlations between the collagen area fraction and the number of fibrocytes (r=0.936; P<0.05) and between the number of CXCR4 fibrocytes and the SDF-1/CXCL12 cells (r=0.802; P<0.05) in the three groups. CONCLUSION: The results show that SW therapy ameliorates myocardial fibrosis after AMI in pigs, which is associated with the decreased amount of fibrocytes.

Fibrocytes are associated with the fibrosis of coronary heart disease.

Fibrocytes contribute significantly to fibrosis in many cardiac diseases. However, it is not clear whether fibrocytes are associated with the fibrosis in coronary heart disease (CHD). The aim of this study was to determine whether fibrocytes are involved in cardiac fibrosis in CHD. We identified the presence of fibrocytes in CHD heart by immunofluorescence and confocal microscopy, examined the collagen volume fraction by Masson's Trichrome staining, and evaluated the correlation between fibrocytes and cardiac fibrosis. In conjunction, we examined the location of CXCL12, a homing factor and specific ligand for CXCR4, by immunohistochemistry. Fibrocytes were identified in 26 out of 27 CHD hearts and in 10 out of 11 normal hearts. Combinations, including CD34/αSMA, CD34/procollagen-I, CD45/αSMA, CXCR4/procollagen-I and CXCR4/αSMA, stained significantly more fibrocytes in CHD hearts as compared with those in normal hearts (p<0.05). There were positive correlations between the collagen volume fraction and the amount of fibrocytes (r=0.558; p=0.003<0.01) and between the number of CXCR4(+) fibrocytes and the CXCL12(+) cells (r=0.741; p=0.000<0.01) in CHD hearts. Based upon these findings, we conclude that fibrocytes, likely recruited through the CXCR4/CXCL12 axis, may contribute to the increase in the fibroblast population in CHD heart.