Ma Tiangang, Qu Danhua, Yan Bingdi, Zhang Qinghua, Ren Jin, Hu Yanbing
Department of Pneumology, The Second Hospital of Jilin University, Changchun, Jilin 130041, P.R. China.
Exp Ther Med. 2018 Jan;15(1):310-314. doi: 10.3892/etm.2017.5380. Epub 2017 Oct 27.
A mutation in the IIb sodium phosphate transporter SLC34A2 gene has recently been described in pulmonary alveolar microlithiasis (PAM) patients. Experiments in this study were aimed at confirming the role of the gene product in PAM by comparing phosphorylated products in extracellular fluid of alveolar epithelial cells overexpressing the SLC34A2 gene or its mutated version. Eukaryotic expression vectors were constructed and transfected into A549 human alveolar epithelial cells. There were three groups of cells including those transfected with empty vector plasmid pcDNA3.1(+) (plasmid control group), those transfected with normal SLC34A2 gene expressed from pcDNA3.1 (normal control group), and those transfected with a version of the PAM SLC34A2 gene linked to the pcDNA3.1(+) (PAM group). Transfection efficiencies were detected by reverse transcription-polymerase chain reaction (RT-PCR). At 48 h after transfection, the concentration of inorganic phosphorus in the culture medium was detected using an automatic biochemical analyzer. Our results showed the concentration of inorganic phosphorus in the supernatant of the normal control group was significantly lower than that in the plasmid control and PAM groups (P<0.01), and the concentration in the PAM group was significantly lower than that in the plasmid control group (P<0.01). Based on our findings it is possible that the SLC34A2 gene mutation is the cause of the pathogenic changes observed in PAM patients, given that the function of the phosphate transporter seems to be affected and it is conceivable that it would lead to extracellular fluid alterations .
最近在肺泡微石症（PAM）患者中发现了IIb型磷酸钠转运体SLC34A2基因的突变。本研究中的实验旨在通过比较过表达SLC34A2基因或其突变体的肺泡上皮细胞外液中的磷酸化产物，来确认该基因产物在PAM中的作用。构建真核表达载体并将其转染至A549人肺泡上皮细胞中。细胞分为三组，分别为转染空载体质粒pcDNA3.1(+)的细胞（质粒对照组）、转染由pcDNA3.1表达的正常SLC34A2基因的细胞（正常对照组）以及转染与pcDNA3.1(+)连接的PAM型SLC34A2基因的细胞（PAM组）。通过逆转录-聚合酶链反应（RT-PCR）检测转染效率。转染后48小时，使用自动生化分析仪检测培养基中无机磷的浓度。我们的结果显示，正常对照组上清液中无机磷的浓度显著低于质粒对照组和PAM组（P<0.01），且PAM组中的浓度显著低于质粒对照组（P<0.01）。基于我们的研究结果，鉴于磷酸转运体的功能似乎受到影响，并且可以想象这会导致细胞外液改变，SLC34A2基因突变有可能是PAM患者中观察到的致病变化的原因。
