Identification of laccase gene family members in peach and its relationship with chilling induced browning / 生物工程学报

The laccase (PpLAC) gene family members in peach fruit were identified and the relationship between their expression pattern and chilling induced browning were investigated. The study was performed using two varieties of peaches with different chilling tolerance, treated with or without exogenous γ-aminobutyric acid (GABA) during cold storage. Twenty-six genes were screened from the peach fruit genome. These genes were distributed on 6 chromosomes and each contained 5-7 exons. The PpLAC gene family members shared relatively similar gene structure and conserved motifs, and they were classified into 7 subgroups based on the cluster analysis. Transcriptome sequencing revealed that the expression levels of PpLAC7 and PpLAC9 exhibited an increasing pattern under low temperature storage, and displayed a similar trend with the browning index of peach fruit. Notably, GABA treatment reduced the degree of browning and inhibited the expression of PpLAC7 and PpLAC9. These results suggested that PpLAC7 and PpLAC9 might be involved in the browning of peach fruit during cold storage.

Role and regulatory mechanism of triggering receptor expressed on myeloid cells 2 in mice lung ischemia/reperfusion injury / 中华危重病急救医学

Objective:To investigate the role and regulatory mechanism of triggering receptor expressed on myeloid cell 2 (TREM2) in mice lung ischemia/reperfusion injury (LIRI).Methods:Thirty-six healthy male C57BL/6 mice were divided into six groups according to the random number method ( n = 6): normal control group, and LIRI 2, 6, 12, 24, 48 hours group. Mice LIRI models were established by clamping the left hilum. The wet/dry weight ratio (W/D) of left lung tissue was measured. Lung injury was observed and evaluated by hematoxylin-eosin (HE) staining and electron microscopy. The levels of interleukins (IL-1β, IL-18) in lung tissue were detected by enzyme linked immunosorbent assay (ELISA). The mRNA expressions of TREM2 and caspase-1 were determined by polymerase chain reaction (PCR). The protein expressions of TREM2, caspase-1, Gasdermin-D (GSDMD) were determined by Western blotting. Results:At 2 hours after LIRI, lung injury began to appear, the lung ultrastructure changed, and the lung injury score increased; at 6 hours, the degree of lung injury was the most serious; after 12 hours, the lung injury gradually reduced and the lung injury score gradually decreased. Compared with the normal control group, lung W/D ratio and lung injury score of LIRI 2, 6, 12, 24, 48 hours groups were significantly higher, the differences were statistically significant (lung W/D ratio: 7.06±0.52, 8.34±0.17, 6.42±0.35, 5.34±0.25, 5.59±0.45 vs. 4.69±0.23; lung injury score: 5.50±0.54, 9.75±0.89, 5.88±0.84, 3.63±0.74, 4.13±0.64 vs. 1.13±0.35, all P < 0.05). Compared with the normal control group, the levels of IL-1β and IL-18 in lung tissue were significantly increased at 2 hours after LIRI, reached a peak at 6 hours [IL-1β (ng/L): 502.76±12.25 vs. 56.50±8.07, IL-18 (ng/L): 414.02±10.75 vs. 81.63±5.29, both P < 0.05], then decreased gradually, and were still significantly higher than the normal control group at 48 hours. The PCR and Western blotting showed that the expression of TREM2 was significantly lower than that in the normal control group at 2 hours after LIRI, and reached a valley at 6 hours [TREM2 mRNA (2 -ΔΔCt): 0.47±0.05 vs. 1.02±0.05, TREM2/GAPDH: 0.23±0.13 vs. 0.48±0.17, both P < 0.05], then gradually increased, and reached the peak at 24 hours [TREM2 mRNA (2 -ΔΔCt): 3.98±0.15 vs. 1.02±0.05, TREM2/GAPDH: 0.71±0.17 vs. 0.48±0.17, both P < 0.05]. The trend of expression of caspase-1 and GSDMD were opposite to that of TREM2, which increased at first and then decreased, and reached a peak at 6 hours after reperfusion [caspase-1 mRNA (2 -ΔΔCt): 2.20±0.13 vs. 1.01±0.02, caspase-1/GAPDH: 0.64±0.02 vs. 0.20±0.06, GSDMD/GAPDH: 1.23±0.01 vs. 0.87±0.02, all P < 0.05]. Conclusions:TREM2 might be involved in LIRI in mice. The mechanism may be related to the effect of TREM2 on caspase-1-mediated pyroptosis.

Clinical application evaluation of serum C1q and other complement factors in the diagnosis and prediction of preeclampsia / 中华检验医学杂志

Objective To observe the levels of serum complement C 1q, C3, C4 and factor B in different phases during normal pregnancy;To evaluate the diagnostic value and the predictive value of serum complement C1q, C3, C4 and factor B in preeclampsia (PE).Methods Three groups of subjectes were enrolled from January 2017 to March 2018 in Department of Obstetrics and Gynecology , Peking University Third Hospital.(1) 30 pregnant women in each group at 8-14 weeks, 20-26 weeks and 28-36 weeks were retrospectively selected , and the serum levels of complement C 1q, C3, C4 and B factors were measured and compared.(2)Selecting 17 cases of early-onset mild PE, 47 cases of early-onset severe PE, 24 cases of late-onset mild PE, 27 cases of late-onset severe PE, and 30 normal pregnant cases of the same gestational stage as early-onset /late-onset controls , through ANOVA analysis and comparison between two groups , this study evaluated the diagnostic value of serum complement C 1q, C3, C4 and factor B in PE.(3)To evaluate the predictive effect in PE, it analyzed serum C1q and factor B levels of pregnant women at 20-26 gestation weeks through prospective nested case-control study of 214 cases.Results The levels of serum C1q remained stable in the whole pregnancy .The levels of C3 and factor B increased at the early stage of pregnancy and remained stable after the middle stage .C4 increased early in pregnancy and then remained stable.Compared with the control group , the levels of serum C1q in all four types of PE patients were significantly decreased ( median: 169 mg/L, 161 mg/L, 165 mg/L, 163 mg/L;early-onset, late-onset control group:187 mg/L, 194 mg/L;U=130.500, 426.500, 159.500, 130.500, all P<0.05).Serum C3 levels of all the other three types of PE patients were significantly lower than those of the control groups (median:1170 mg/L, 1323 mg/L, 1223 mg/L;early-onset, late-onset control groups: 1438 mg/L, 1434 mg/L;U =379.000, 246.000, 160.000, all P <0.05 ), except for the early-onset mild PE (1275 mg/L).Serum C4 levels of patients with early/late onset severe PE were significantly lower than those of the control groups ( median: 140 mg/L, 142 mg/L;early-onset, late-onset control groups:223 mg/L, 235 mg/L;U =329.500, 136.500, both P <0.001 ) .Serum factor B levels showed no statistical difference among 3 early on-set groups or among 3 late on-set groups ( early-onset group median:332 mg/L,318 mg/L,early-onset control group 312 mg/L;late-onset group median:316 mg/L,314 mg/L, late-onset group 303 mg/L;χ2 =5.990, 1.77, all P>0.05).33 (15.4％) cases developed PE out of 214 pregnant women with PE risk factors .Compared to those who didn′t develop PE , it showed no statistical difference of serum C1q, C3, C4, and factor B levels at 20-26 gestational weeks of the women who subsequently developed PE ( C1q:175 mg/L vs.184 mg/L; C3:1523 mg/L vs.1467 mg/L; C4:230 mg/L vs.229 mg/L;FB:344 mg/L vs.320 mg/L;U=2090.000, 1575.000, 2058.500, 1362.000, all P>0.05).Compared to those of the healthy pregnant controls , it showed no statistical difference of serum C1q, C3 and C4 levels of 20-26 gestational weeks of the women who subsequently developed PE (C1q:175 mg/L vs.190 mg/L; C3:1523 mg/L vs.1428 mg/L; C4:230 mg/L vs.227 mg/L; U=353.000, 395.000, 493.500, all P >0.05),while it showed statistical difference (344 mg/L vs.306 mg/L;U=233.500, P=0.007) for factor B.Conclusions Serum C1q level of PE patients significantly decreased, which can be used as potential indicators of PE diagnosis , but serum C1q, C3, C4 level of 20-26 gestational weeks cannot predict risk of PE .Factor B cannot serve as serum index of PE diagnosis , but its serum levels at 20-26 gestational weeks werer higher than those of normal pregnant controls , factor B may be a potential predictor , but need further verification .