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Objective To investigate the damage mechanism of typeⅡalveolar epithelial cells (AECⅡ) after hyperoxia exposure by proteomics. Methods The primary AECⅡ of preterm Sprague-Dawley (SD) rats were divided into normoxia and hyperoxia groups, and cultured in room air (21% O2) or hyperoxia (95% O2) condition, respectively. The cell morphology change was observed under an inverted contrast microscope; the protein expressions of Bcl-2 and caspase-3 were detected by Western Blot to ensure a successful model. Total protein in AECⅡ was collected, and mass spectrometry-based tandem mass tag (TMT)-labeled quantitative proteomics were used to detect the change of protein profile. Proteins with changes greater than 1.5-fold and P < 0.05 were considered differentially expressed, and bioinformatics analysis was performed. According to the proteomic results, AECⅡ were divided into three groups:normoxia group, hyperoxia group and hyperoxia+MW167 group (γ-secretase inhibitor MW167 was added to culture medium 30 minutes before they were placed into the chamber). The cell viability was detected by the cell proliferation and toxicity kit (CCK-8), and the expressions of Hes1, Bax mRNA were detected by real-time fluorescence quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Results ① The cells in the normoxia group proliferated and prolonged significantly, and the cytoplasmic particulate matter was abundant. In the hyperoxia group, nucleus pyknosis and cytoplasmic particulate matter decreased significantly. Compared with the normoxia group, the expression of caspase-3 in the hyperoxia group was significantly increased, and the expression of Bcl-2 was significantly decreased (caspase-3/GAPDH: 1.352±0.086 vs. 0.769±0.080, Bcl-2/GAPDH: 0.614±0.060 vs. 1.361±0.078, both P < 0.01).② A total of 162 differentially expressed proteins were identified between normoxia and hyperoxia groups, the proteins up-regulated by hyperoxia were commonly associated with response processes to various stimuli, and located in the extracellular region; the proteins down-regulated by hyperoxia were commonly associated with synthesis of substances, and located in the cellular matrix. KEGG Pathway analyses suggested that metabolism by cytochrome P450, oxidative phosphorylation, and Notch signaling pathway were associated with the mechanism of hyperoxia injury on AECⅡ.③Compared with the normoxia group, the viability of cells in the hyperoxia group was significantly decreased, and the expressions of Hes1 and Bax mRNA were significantly increased [cell viability (A value): 0.060±0.003 vs. 1.058± 0.017, Hes1 mRNA (2-ΔΔCt): 2.235±0.606 vs. 1.144±0.107, Bax mRNA (2-ΔΔCt): 2.210±0.240 vs. 1.084±0.096, all P < 0.05]. Compared with the hyperoxia group, the viability of cells in the hyperoxia+MW167 group was significantly increased, and the expressions of Hes1 and Bax mRNA were significantly decreased [cell viability (A value): 0.271±0.025 vs. 0.060±0.003, Hes1 mRNA (2-ΔΔCt): 0.489±0.046 vs. 2.235±0.606, Bax mRNA (2-ΔΔCt): 1.289±0.041 vs. 2.210±0.240, all P < 0.05]. Conclusion The mechanism of hyperoxia injury on AECⅡ may be related to the metabolism by cytochrome P450, oxidative phosphorylation and activation of Notch signaling pathway.
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Objective To analyze the main clinical manifestations,laboratory features and prognosis of neonatal intrahepatic cholestasis caused by Citrin defiency (NICCD).Methods Twenty-nine NICCD infants were diagnosed by blood tandem mass spectrometry (MS-MS)analysis and/or SLC25A13 mutation analysis from July 2012 to February 2015 in Children's Hospital of Chongqing Medical University.Clinical data of 29 cases were analyzed retrospectively which included manifestations,laboratory features and prognosis.The general situation,feeding,liver function,growth were followed up.Results Twenty-nine infants suffering from NICCD presented jaundice in an early time,and some clinical manifestations were investigated such as hepatomegaly (20/29 cases),splenomegaly (3/29 cases),anemia (14/29 cases),and failure to thrive (9/29 cases).Laboratory data suggested that all of 29 patients had increased conjugated bilirubin,total bile acid,γ-glutamyl transferase and alkaline phosphatase.Some patients also showed abnormal coagulation function (20/22 cases),dyslipidemia (9/20 cases),increased blood lactic acid (22/26 cases) and alpha-fetoprotein (14/14 cases),decreased albumin (24/29 cases),blood glucose (17/22 cases) and ceruloplasmin (4/4 cases).The pathological analysis of one patient's liver indicated the edema and degeneration of liver cells,intrahepatic cholestasis and a small amount of fibrous tissue hyperplasia in portal area.MS-MS analysis of blood samples revealed distinctive increase in methionine,tyrosine,threonine,citrulline,arginine and free carnitine,long chain acyl-carnitine in most patients.Gas chromatography-mass spectrometer (GC-MS) analysis of urine samples mainly showed elevated 4-hydroxyphenyllactic acid and 4-hydroxyphenylpyruvic acid.Prognosis showed that most of the NICCD patients (8/29 cases) could recover in one-year old with a lactose-free,medium chain triglyceride-enriched formula,and one patient died of liver cirrhosis.Three patients at over one-year old had the preference of a high protein and low carbohydrate diet.Conclusions Infants might be considered to have NICCD if they have jaundice in an early time,with the clinical characteristics of hepatomegaly,splenomegaly,abnormal coagulation function,anemia,failure to thrive,dyslipidemia,decresed albumin and blood glucose,increased blood lactic acid and alpha-fetoprotein.After that further tests of MS-MS,GC-MS and gene analysis of this disease are needed to confirm diagnosis.