ABSTRACT
This study attempts to discuss the correlation between UGT1A1*28 as uridine diphosphate glucuronosyltransferase gene promoter and coding region Gly71Arg gene polymorphism with neonatal hyperbilirubinemia of neonates in Wuhan.A total of 168 neonates were divided into the hyperbilirubinemia group (case group,n=108) and healthy neonates group (control group,n=60).Their DNA was obtained through blood extraction.The gene exon mutation of UGT1A1 was detected by Sanger sequencing,which revealed the relationship between UGT 1A 1*28 and Gly71Arg polymorphism with neonatal hyperbilirubinemia of neonates.The results showed that:(1) The frequency of UGT1Al*28 allele mutation in the case group and the control group was 9.3％ and 10％ respectively,with the difference being not significant between the two groups (P＞0.05).(2) The frequency of Gly71Arg allele mutation in the case group and the control group was 35.1％ and 21.7％ respectively,with the difference being significant between the two groups (P＜0.01).(3) The serum bilirubin level of Gly71Arg mutant homozygous and heterozygous subgroups (n=66) in the case group was 302.7±31.4 μmol/L,which was significantly higher than 267.3±28.5 μmol/L of the wild subgroup (n=42) (P＜0.01).It was suggested that the occurrence of neonatal hyperbilirubinemia of neonates in Wuhan was not associated with UGT 1A1*28 gene polymorphism,but closely with the Gly71Arg gene polymorphism.Meanwhile,the Arg allele mutation was related to the degree of jaundice.
ABSTRACT
This study examined the effects of retinoic acid (RA),PD98059,SP600125 and SB203580 on the hyperoxia-induced expression and regulation of matrixmetalloproteinase-2 (MMP-2) and metalloproteinase-2 (TIMP-2) in premature rat lung fibroblasts (LFs).LFs were exposed to hyperoxia or room air for 12 h in the presence of RA and the kinase inhibitors PD98059 (ERK1/2),SP600125 (JNK1/2) and SB203580 (p38) respectively.The expression levels of MMP-2 and TIMP-2 mRNA were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR).MMP-2 activity was measured by zymography.The amount of p-ERK1/2,REK1/2,p-JNK1/2,JNK1/2,p-p38 and p38 was determined by Western blotting.The results showed that:(1) PD98059,SP600125 and SB203580 significantly inhibited p-ERK1/2,p-JNK1/2 and p-p38 respectively in LFs; (2) The expression of MMP-2 mRNA in LFs exposed to hyperoxia was decreased after treatment with RA,SP600125 and SB203580 respectively (P＜0.01 or 0.05),but did not change after treatment with PD98059 (P＞0.05).Meanwhile,RA,PD98059,SP600125 and SB203580 had no effect on the expression of TIMP-2 mRNA in LFs exposed to room air or hyperoxia (P＞0.05); (3) The expression of pro- and active MMP-2 experienced no change after treatment with RA or SP600125 in LFs exposed to room air (P＞0.05),but decreased remarkably after hyperoxia (P＜0.01 or 0.05).SB203580 inhibited the expression of pro- and active MMP-2 either in room air or under hyperoxia (P＜0.01).PD98059 exerted no effect on the expression of pro- and active MMP-2 (P＜0.05).It was suggested that RA had a protective effect on hyperoxia-induced lung injury by down-regulating the expression of MMP-2 through decreasing the JNK and p38 activation in hyperoxia.
ABSTRACT
This study investigated the effects of hyperoxia on dynamic changes of thioredoxin-1 (Trx1)and thioredoxin reductase-1 (TrxR1) in alveolar type Ⅱ epithelial cells (AECⅡ) of premature rats.Pregnant Sprague-Dawley rats were sacrificed on day 19 of gestation.AEC Ⅱ were isolated and purified from the lungs of premature rats.When cultured to 80％ confluence,in vitro cells were randomly divided into air group and hyperoxia group.Cells in the hyperoxia group were continuously exposed to 95％ O2/5％ CO2 and those in the air group to 95％ air/5％ CO2.After 12,24 and 48 h,cells in the two groups were harvested to detect their reactive oxygen species (ROS),apoptosis,TrxR1 activity and the expressions of Trx1 and TrxR1 by corresponding protocols,respectively.The results showed that AEC Ⅱ exposed to hyperoxia generated excessive ROS and the apoptosis percentage in the hyperoxia group was increased significantly at each time points as compared with that in the air group (P＜0.001).Moreover,TrxR1 activity was found to be markedly depressed in the hyperoxia group in comparison to that in the air group (P＜0.001).RT-PCR showed the expressions of both Trx1 and TrxR1 mRNA were significantly increased in AEC Ⅱ exposed to hyperoxia for 12 and 24 h (P＜0.01),respectively.At 48 h,the level of Trx1 mRNA as well as that of TrxR1 mRNA in the hyperoxia group was reduced and showed no significant difference from that in the air group (P＞0.05).Western blotting showed the changes of Trx 1 protein expressions in the hyperoxia group paralleled those of Trx1 mRNA expressions revealed by RT-PCR.It was concluded that hyperoxia can up-regulate the protective Trx1/TrxR1 expressed by AEC Ⅱ in a certain period,however,also cause dysfunction of the cytoplasmic thioredoxin system by decreasing TrxR1 activity,which may contribute to the progression of oxidative stress and cell apoptosis and finally result in lung injury.
ABSTRACT
To investigate the effects of hyperoxia on mitochondrial multienzyme complex Ⅲ (cytochrome, Cytb) and V (ATPase6, 8) in premature newborn rat lung, the l-day-old preterrn SD rats were randomly assigned to hyperoxia group and air group. The rats in hyperoxia group were con- tinuously exposed to 85% oxygen and those in air group to room air. After 1, 4, 7, 10, 14 day(s) of exposure, these rats were killed, total lung RNA was extracted and Cytb, ATPase6, 8 mRNA were detected by reverse transcription polymerase chain reaction (RT-PCR). Western blotting was used to detect the expression of Cytb protein in lung tissue. The results showed that compared with air group, Cytb mRNA expression was significantly increased (P>0.05) after 1, 4 day(s) of exposure. The general tendency decreased after 7 days, and its expression became weak but difference in mRNA expression between the two groups was not significant (P>0.05). ATPase6 mRNA expression was significantly increased 1 day after the exposure (P<0.05) and did not show any significant change 4, 7, 10 days after the exposure (P>0.05). At the 14th day, ATPase6 mRNA expression was significantly increased (P<0.05). ATPase8 mRNA expression did not show any significant change 1, 4, l0 day(s) after the exposure (P>0.05). At the 7th and 14th day, ATPase8 mRNA expression was significantly increased (P<0.05). Western blotting showed that Cytb protein expression was increased 1,4 day(s) after the exposure, but the difference between the two groups was not significant (P>0.05). The gen- eral tendency was decreased after 7 days, and its expression became weak but difference was not sig- nificant 7, 10 days after the exposure (P>0.05). At day 14 its expression became significantly weak (P<0.05). We are led to conclude that exposure to high concentrations of oxygen can significantly change the expression of Cytb and ATPase6, 8, which results in uncoupling of oxidative phosphorylation in mitochondrial respiration chain, and plays an important role in the mechanism of hyperoxia-induced lung injury.