Expression of Occludin in lung tissues of newborn rats with bronchopulmonary dysplasia and its influence on pulmonary epithelial permeability / 中华实用儿科临床杂志

Objective To explore the dynamic changes of Occludin gene and protein levels in lung tissues of newborn rats with hyperoxia-induced bronchopulmonary dysplasia (BPD) in the early phase and its effect on pulmonary epithelial permeability.Methods One hundred and sixty newborn Wistar rats were randomly assigned to hyperoxia group (900 mL/L oxygen)and normoxia group (210 mL/L oxygen) according to different oxygen concentrations,80rats in each group.Rats were sacrificed and lung tissues were removed on 1,3,5,7 d after treatment.Bronchoalveolar lavage fluid (BALF):serum FD4 ratio was detected;location and expression of Occludin were examined by immunofluorescence staining and Western blot; messenger RNA (mRNA) was studied by reverse transcription-PCR.Results There was no obvious difference in the BALF and serum FD4 ratio (1.533 ±0.122 vs 1.575 ± 0.140,P ＞ 0.05) between the hyperoxia group and the normoxia group on the first day.After 3 days of hyperoxia exposure,the ratio of FD4between BALF and serum was significantly higher than that in the normoxia group(1.365 ±0.159 vs 1.615 ±0.196,P ＜ 0.05).And after 5 or 7 days of hyperoxia exposure,the ratio of FD4 between BALF and serum was dramatically increased(1.245 ±0.152 vs 3.211 ±0.799,1.178 ± 0.594 vs 5.15 ± 0.967,all P ＜ 0.01).On the 7 day,immunofluorescence staining showed Occludin distribllted in a consecutive line along lung epithelial cell membrane in the normoxia group,while in the hyperoxia group Occludin was distributed in a discontinuous line and lacking intensity.There was no obvious difference in Occludin mRNA level between the hyperoxia group and normoxia group on the first day(2.15 ±0.33 vs 2.23 ± 0.39,P ＞ 0.05).Compared to the normoxia group,the decrease in Occludin mRNA level was statistically significant after 3 or 5 days of hyperoxia exposure(2.46 ± 0.27 vs 2.00 ± 0.19,2.62 ± 0.28 vs 2.15 ± 0.20,all P ＜ 0.05),and after 7 days of hyperoxia exposure,the Occludin mRNA level dramatically declined (3.08 ± 0.43 vs 2.01 ±0.34,P ＜0.01).There was no obvious difference in Occludin protein level between the hyperoxia group and normoxia group on the 1 st and the 3th day(1.00 ± 0.05 vs 1.05 ± 0.03,1.24 ± 0.06 vs 1.17 ± 0.04,all P ＞ 0.05).Compared to the normoxia groups,the decrease in Occludin protein level was statistically significant after 5 days of hyperoxia exposure (1.03 ± 0.04 vs 0.93 ± 0.05,P ＜ 0.05),and after 7 days of hyperoxia exposure,the Occludin protein level dramatically declined(0.96 ± 0.14 vs 0.65 ± 0.07,P ＜ 0.01).There was a significantly negative correlation between Occludin protein expression and pulmonary epithelial permeability after hyperoxia exposure (r =-0.755,P ＜0.01).Conclusions Downregulation of Occludin hyperoxia-induced may lead to the increase of pulmonary epithelial paracellular permeability,which participates in the development of pulmonary edema in the early phase of BPD induced by hyperoxia.

Evaluation of Lung Epithelial Permeability in Patients with Type 2 Diabetes Mellitus using 99mTc-DTPA Aerosol Scintigraphy / 대한내분비학회지

BACKGROUND: Diabetes mellitus is often accompanied by complicated microangiopathy, such as, retinopathy, nephropathy, peripheral neuropathy, cardiovascular autonomic neuropathy or macroangiopathy, as well as by coronary artery disease and cerebrovascular disease. However, there have been few reports concerning the pulmonary involvement of diabetes. Recently, capillary basement membrane thickening, nonenzymatic glycosylation of tissue proteins, abnormalities of endothelial cells and increased damage by free radicals were reported as the underlying basis for the reduced lung permeability. 99mTc-DTPA aerosol scintigraphy is a noninvasive, accurate method, which evaluates the permeability of lung epithelial membranes. The clearance rate of 99mTc-DTPA in lungs may correlate inversely with the lung's epithelial permeability. We investigated the relationship between microangiopathies and the lung epithelial permeability in patients with diabetes using 99mTc-DTPA aerosol scintigraphy. METHODS: The study group comprised of 33 patients with type 2 diabetes mellitus, with no clinical evidence of past or present respiratory disease. The patients were divided into two groups in relation to the complications. Group 1: 16 patients with more than one of the complications of retinopathy, nephropathy, cardiovascular autonomic neuropathy and/or peripheral neuropathy, and comprised of 3 males and 13 females, with a mean age of 52.9 +/- 9.6 years. Group 2: 17 patients with no complications, and comprised of 5 males and 12 females with a mean age of 52.8 +/- 11.5 years. Group 3: as a control group, comprised of 11 healthy people: 4 males 4 and 7 females with a mean age of 44.2 +/- 12.5 years. 99m-Tc-DTPA aerosol scintigraphy was performed in the subjects by inhalation of 30 mCi 99mTc-DTPA aerosol and oxygen (9 l/min) using an aero-vent jet nebulizer as the lung delivery system. To evaluate the diabetic complications, CAN (Cardiovascular Autonomic Neuropathy), and NCV (Nerve Conduction Velocity) tests for peripheral neuropathy, fundoscopy for retinopathy and 24 hours urine microalbumin for nephropathy were performed. RESULTS: The mean durations of diabetes in Groups 1 and 2 were 11.1 +/- 4.7 years and 3.8 +/- 2.1 years, respectively (p<0.05). The mean clearance rates of 99mTc-DTPA were found to be 72.1 +/- 19.5min, 52.6 +/- 19.7 min, and 47.1 +/- 10.9 min for Groups 1, 2, and 3, respectively. The mean clearance rate of Group 1 was significantly longer than for Groups 2 and 3 (p<0.05). In other words, the pulmonary epithelial permeability was reduced in diabetic patients with complications compared to the patients without complication and/or the normal controls. Significant positive correlation was found between the pulmonary clearance rate of 99mTc-DTPA, and peripheral neuropathy and cardiovascular autonomic neuropathy (p<0.05). Conclusions: The lungs may be a target organ for diabetes, and impaired pulmonary epithelial permeability seems to be closely related to other diabetic microangiopathies. Therefore, we recommend that 99mTc-DTPA aerosol scintigraphy be used as a technique for assessing lung injury in diabetic patients.

Clearance rate of inhaled 99mTc-DTPA in systemic sclerosis / 대한내과학회지

BACKGROUND: We measured the clearance rate of inhaled 99mTc-diethyl triaminepentaacetic acid (DTPA) aerosol in patients with systemic sclerosis. We also investigated its correlation with respiratory function test and acute phase reactant proteins. METHODS: Ten patients with systemic sclerosis, ten patients with rheumatoid arthritis, and ten healthy controls were included. Dynamic scintigrams (20 seconds/frame, up to 30 minutes) were obtained following inhalation of 99mTc-DTPA aerosol through a radioaerosol delivery system. The time to half clearance (T1/2) was calculated from the time-activity curves. High resolution computed tomography, pulmonary function test and laboratory tests such as ESR, CRP, and complement (C3/C4) were performed. RESULTS: 1) Mean T1/2 values of 99mTc-DTPA clearance after inhalation were 28.1+/-3.8, 57.9+/-20.9, and 64.3+/-13.0 minutes in systemic sclerosis, rheumatoid arthritis and normal controls, respectively. Mean T1/2 value in systemic sclerosis was significantly reduced compared with those of rheumatoid arthritis group (p<0.001) and normal controls (p=0.001).2) No significant correlations were found between mean T1/2 and FEV1/FVC, FVC or DLco in patients with systemic sclerosis. 3) There was no significant correlation between mean T1/2 and ESR or CRP in patients with systemic sclerosis. And in patients with rheumatoid arthritis, mean T1/2 value correlated significantly with ESR and CRP. CONCLUSION: The clearance rate of inhaled 99mTc-DTPA was significantly increased in patients with systemic sclerosis and had no significant correlation with pulmonary function test and acute phase reactants, but was found to have significant correlations with ESR and CRP in patients with rheumatoid arthritis.