BACKGROUND:Previously,a SENP1 gene-silenced human alveolar epithelial cell line was successfully constructed in vitro,and the role of SENP1 in hyperoxic lung injury was investigated at the cellular level.OBJECTIVE:To construct a mouse model of alveolar type II epithelial cell-specific knockout of SENP1 gene based on the Cre-loxP recombinase system.METHODS:SENP1flox/-mice were self-crossed to obtain SENP1flox/flox and SENP1flox/-mice;Sftpc-Cre+/+mice were crossed with wild-type mice to obtain more Sftpc-Cre+/-mice.Sftpc-Cre+/+or offspring Sftpc-Cre+/-mice were crossed with SENP1flox/-or offspring SENP1flox/flox mice to obtain SENP1flox/-Sftpc-Cre+/-double heterozygous mice.SENP1flox/-Sftpc-Cre+/-mice were then crossed with SENP1flox/flox mice to obtain SENP1flox/floxSftpc-Cre+/-mice.The genomic DNA was extracted by tail clipping and amplified by PCR.The amplified product was subjected to agarose gel electrophoresis to determine the mouse genotypes.Lung tissues of SENP1flox/flox and SENP1flox/floxSftpc-Cre+/-mice were subjected to immunofluorescence double-labelling and western blot assay to verify the knockdown effect of SENP1 gene.Heart,liver,lung and kidney tissues of SENP1flox/flox and SENP1flox/floxSftpc-Cre+/-mice were stained with hematoxylin-eosin to observe the histomorphology of each organ in the two groups of mice.RESULTS AND CONCLUSION:SENP1flox/floxSftpc-Cre+/-mice were correctly screened by agarose gel electrophoresis.Immunofluorescence double-labeling experiments showed that the mean fluorescence intensity of SENP1 was reduced in lung tissues of SENP1flox/floxSftpc-Cre+/-mice compared with that of SENP1flox/flox mice(P<0.01)and no significant co-localization of SENP1 and Sftpc was observed(P<0.01).Western blot results showed that SENP1 protein expression was reduced in lung tissues of SENP1flox/floxSftpc-Cre+/-mice compared with SENP1flox/flox mice(P<0.001).Hematoxylin-eosin staining showed no significant alterations in the histomorphology of heart,liver,lung and kidney tissues in SENP1flox/flox and SENP1flox/floxSftpc-Cre+/-mice.This study successfully constructed alveolar type II epithelial cell-specific knockout SENP1 gene mice using the Cre-loxP recombinase system,which provides a good tool for the subsequent study of the role of SENP1 gene in lung diseases such as bronchopulmonary dysplasia and idiopathic pulmonary fibrosis,in which alveolar type II epithelial cells are the main damage cells.

BACKGROUND:Previously,a SENP1 gene-silenced human alveolar epithelial cell line was successfully constructed in vitro,and the role of SENP1 in hyperoxic lung injury was investigated at the cellular level.OBJECTIVE:To construct a mouse model of alveolar type II epithelial cell-specific knockout of SENP1 gene based on the Cre-loxP recombinase system.METHODS:SENP1flox/-mice were self-crossed to obtain SENP1flox/flox and SENP1flox/-mice;Sftpc-Cre+/+mice were crossed with wild-type mice to obtain more Sftpc-Cre+/-mice.Sftpc-Cre+/+or offspring Sftpc-Cre+/-mice were crossed with SENP1flox/-or offspring SENP1flox/flox mice to obtain SENP1flox/-Sftpc-Cre+/-double heterozygous mice.SENP1flox/-Sftpc-Cre+/-mice were then crossed with SENP1flox/flox mice to obtain SENP1flox/floxSftpc-Cre+/-mice.The genomic DNA was extracted by tail clipping and amplified by PCR.The amplified product was subjected to agarose gel electrophoresis to determine the mouse genotypes.Lung tissues of SENP1flox/flox and SENP1flox/floxSftpc-Cre+/-mice were subjected to immunofluorescence double-labelling and western blot assay to verify the knockdown effect of SENP1 gene.Heart,liver,lung and kidney tissues of SENP1flox/flox and SENP1flox/floxSftpc-Cre+/-mice were stained with hematoxylin-eosin to observe the histomorphology of each organ in the two groups of mice.RESULTS AND CONCLUSION:SENP1flox/floxSftpc-Cre+/-mice were correctly screened by agarose gel electrophoresis.Immunofluorescence double-labeling experiments showed that the mean fluorescence intensity of SENP1 was reduced in lung tissues of SENP1flox/floxSftpc-Cre+/-mice compared with that of SENP1flox/flox mice(P<0.01)and no significant co-localization of SENP1 and Sftpc was observed(P<0.01).Western blot results showed that SENP1 protein expression was reduced in lung tissues of SENP1flox/floxSftpc-Cre+/-mice compared with SENP1flox/flox mice(P<0.001).Hematoxylin-eosin staining showed no significant alterations in the histomorphology of heart,liver,lung and kidney tissues in SENP1flox/flox and SENP1flox/floxSftpc-Cre+/-mice.This study successfully constructed alveolar type II epithelial cell-specific knockout SENP1 gene mice using the Cre-loxP recombinase system,which provides a good tool for the subsequent study of the role of SENP1 gene in lung diseases such as bronchopulmonary dysplasia and idiopathic pulmonary fibrosis,in which alveolar type II epithelial cells are the main damage cells.

Dry eye disease(DED)refers to a condition characterized by reduced stability of the tear film or an imbalance in the microenvironment of the ocular surface, resulting from abnormalities in quality, quantity and kinetics of tear. This condition leads to various ocular discomforts and even visual impairment. The pathogenesis of DED is multifactorial and current treatment mainly focuses on symptom relief and preservation of visual function. Acupuncture has shown effectiveness in treating dry eye, although its underlying mechanism remains incompletely understood. Proteomics technology offers a comprehensive and systematic approach to studying the functions, structures and interactions of proteins. Its application in DED research can provide valuable insights into the dynamic changes in protein levels associated with different etiology or the course of DED and facilitate the identification of potential biomarkers. Furthermore, proteomics can systematically explore the regulatory mechanisms underlying acupuncture treatment for DED, providing a theoretical basis for acupuncture treatment research and contributing to the understanding of its effects at a fundamental level. This paper aims to explore the potential application of proteomics in both clinical and basic research on DED. Ultimately, it strives to offer scientific and effective strategies for the diagnosis and treatment of DED and advance our knowledge of the mechanisms underlying acupuncture therapy.

Objective To establish a liquid chromatography-tandem mass spectrometry ( LC-MS/MS) method for the quantification of creatinine-correctedsarcosine in urine for the prostate cancer diagnosis and treatment.Methods It performed the method establishment and evaluation in this study.Random unrine samples were collected from 36 subjects with prostate cancer, 15 subjects with benign prostatic hyperplasia and 76 healthy people receiving medical examination.Urine samples mixed with [ 2 H3 ]-labeled sarcosine were treated by precolumn derivation using dansyl chloride, then analyzed by LC-MS/MSsystem in multiple reaction monitor ( MRM) mode.Sarcosine and creatinine were quantified by the isotope internal standard method and the standard curve was employed with a series of calibration.The limit of detection, precision and recovery were also evaluated in this study.The results of this methodology were compared with those of the enzymatic method.Results Sarcosine could be distinguished against its isomers completely. The linear equation of sarcosine was Y=2.045 6X+0.068 9, R2 =0.994.The limit of detection and limit of quantity were 8 ng/ml and 25 ng/ml respectively.The intraassay and interassay coefficients of variation were both below 6%.The recovery ratio of sarcosine ranged from 96.8%to 105.1%.The results from the ID-LC-MS method correlated with those from enzymatic method (R2 =0.815, P <0.01).Compared to enzymatic method, the average bias of sarcosine was -37.1%.Conclusions It established a LC-MS method for urinary sarcosine quantification with good specificity, sensitivity and repeatability.This method can provide a reliable platform for the diagnosis of prostate cancer.