E3 ubiquitin ligase COP1-mediated CEBPB ubiquitination regulates the inflammatory response of macrophages in sepsis-induced myocardial injury

CCAAT/enhancer-binding protein beta (CEBPB) has been associated with sepsis. However, its role in sepsis-induced myocardial injury (SIMI) remains ill-defined. This research was designed to illustrate the involvement of CEBPB in SIMI and its upstream modifier. The transcriptomic changes in heart biopsies of mice that had undergone polymicrobial sepsis were downloaded from the GEO dataset for KEGG enrichment analysis. CEBPB, on the TNF signaling pathway, was significantly enhanced in the myocardial tissues of mice with SIMI. Downregulation of CEBPB alleviated SIMI, as evidenced by minor myocardial injury and inflammatory manifestations. Moreover, ubiquitination modification of CEBPB by constitutive photomorphogenesis protein 1 homolog (COP1) led to the degradation of CEBPB and inhibited inflammatory responses in macrophages. Upregulation of COP1 protected against SIMI in mice overexpressing CEBPB. Collectively, our findings demonstrated that COP1 protected the heart against SIMI through the ubiquitination modification of CEBPB, which might be a novel therapeutic approach in the future.

[A FISH technique for simultaneous detection of fluorescent R-band and in situ hybridization signals]

OBJECTIVE

To develop a simple method for detecting DNA probes directly on R-banded chromosomes.

METHODS

After sixty-seven hours culture, human peripheral blood lymphocytes were synchronized for 5 to 6 hours by adding Hoechst 33258 and BUdR, and then arrested by standard cytogenetic procedures. The slides were mounted with 2 x SSC and exposed with a 20W UV light which was about 10cm above the slides for 20 min at 75 degrees C. The biotinylated probes, such as the cosmid and YAC clones on 5p specific region and pBamX7, were hybridized on to the slides. After washing, the slides were treated with avidin-FITC and amplified with additional layer of biotinylated anti-avidin and avidin-FITC, and counterstained with propidium iodide in an antifade solution. Fluorescent signals and R-bands were observed simultaneously under Olympus BX 60 fluorescence microscope equipped with a WIB filter.

RESULTS

The chromosomal location of the greenish-yellow signals could be directly identified on the R-banded chromosome background.

CONCLUSION

This method can serve as a rapid and precise system for chromosomal localization of DNA markers.

[A cohort study on the relationship between the mortality of cerebro-vascular diseases and farmer smokers]

The relationship between the mortality of cerebro-vascular diseases and farmer smokers in Shifang County was studied. The results indicated that the mortality of cerebro-vascular diseases in the male groups of cigarette-smokers older than 65 and cigar-smokers older than 55 was significantly higher than that of the nonsmokers (P < 0.05), the RR being 1.68-3.22. Also, the mortality in the female groups of cigarette-smokers older than 55 and cigar-smokers older than 65 was significantly higher than that of the non-smokers (P < 0.05), the RR being 1.99-3.19. The sex-specific mortalities of the other age groups revealed no significant differences in spite of some inequalities in smoking (P < 0.05). Age should be one of the risk factors for the death of cerebro-vascular diseases regardless of the sex. The mortality rose with the increasing accumulated amount of smoking. The relationship was not significant between the mortality of cerebro-vascular diseases and short-term smokers with small dose (P > 0.05). However, when the accumulated amount reached certain degree, i.e. the smoker consumed cigar more than 270 kg or consumed cigarette more than 10,000 packs, the relationship between the behavior of cigar-smoking and cigarette-smoking and the mortality became apparent, the RR being 2.53-3.91 (P < 0.01).