AIMTo investigate the role of endothelin-1 in the pathogenesis of neurogenetic pulmonary edema.

METHODSThe levels of endothelin-1 in plasma and lung were measured in rats which suffered from diffuse brain injury on Marmarous' model. The changes of endothelin-1 in the lungs were also detected using an immunohistochemical method.

RESULTSAfter heavy diffuse brain injury in rats, the levels of endothelin-1 in plasma and lung began increasing at 1 hour, and peaked at 6 hour. Though a little declining at 24 hour, it maintained a higher level within 48 hours (P < 0.05). Pulmonary pathology showed that after brain injury there were congestion, swelling in pulmonary microvessels with broadened pulmonary interstitial tissue, and leucocyte infiltration was dominated by neutrophils and monocytes from 1 hour on, which peaked at 6 hour. More serious congestion, swelling and protein effusion in pulmonary alveoli were observed at both 24 h and 48 h. Immunohistochemically, endothelin-1 had more significant expression and higher levels of OD in the experimental groups than that in the control's, the most significance of which was at 6 hour.

CONCLUSIONThe inflammatory injury mechanism caused by endothelin-1 may play an important role in neurogenic pulmonary edema.

Animals ; Endothelin-1 ; metabolism ; Lung ; metabolism ; Male ; Pulmonary Alveoli ; metabolism ; Pulmonary Edema ; etiology ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo investigate the protective and therapeutic effects of pulmonary surfactant in the pathogenesis of chronic obstructive pulmonary disease (COPD) in hamsters.

METHODSCOPD animal model was established by smoke inhalations and intratracheal instillations of pancreatic elastase in hamsters. Ninty hamsters were divided into 9 groups as follows: normal group (N), two groups received smoke inhalations for 1 and 3 months (S1 and S3), one group received intratracheal instillation of surfactant (10 mg/100 g BW) for once after 1 month smoking (SP1), one group was treated with surfactant after 1.5, 2 and 2.5 months of smoking (SP3), and two groups received intratracheal administration of elastase (40 U/100 g BW) and were killed after 1 month and 3 months, respectively (E1 and E3). The surfactant was injected intratracheally after 1 week, 0.5, 1.0, 1.5, 2.0, and 2.5 months, followed by administration with elastase (EP1 and EP3). EP1 group were killed at the first month, and EP3 at the third month. Light microscopy and electromicroscopy observations were performed in each group. Pulmonary mean linear intercept (MLI), mean alveolar numbers (MAN), and pulmonary alveolar area (PAA) was measured by image analysis. The expression of surfactant protein A (SP-A) were observed by immunohistochemistry.

RESULTSSmoking for 3 months and instillations of elastase resulted in chronic bronchitis and emphysema. MLI and PAA increased and MAN decreased in all the experimental groups compared with in the normal group (P < 0.05 or P < 0.01). Administration of surfactant for 3 months resulted in statistically significant inhibition of pulmonary injury. MLI and PAA decreased and MAN increased in SP3 compared with in S3. Only MLI decreased in EP3 compared with E3. The expressions of SP-A in the type II alveolar epithelia decreased in S3 and E3 (compared with the normal group P < 0.01). After pulmonary surfactant intervention, the expression of SP-A increased significantly.

CONCLUSIONPulmonary surfactant may have a long-term protective effect on chronic smoking and elastase-induced COPD.

Animals ; Cricetinae ; Male ; Mesocricetus ; Pancreatic Elastase ; Pulmonary Alveoli ; ultrastructure ; Pulmonary Disease, Chronic Obstructive ; metabolism ; prevention & control ; Pulmonary Surfactant-Associated Protein A ; metabolism ; Pulmonary Surfactants ; therapeutic use ; Smoking

In order to ascertain the role of TNF-alpha in pulmonary tuberculosis, we determined the TNF-alpha productivity of alveolar macrophages(AMs) obtained by bronchoalveolar lavage(BAL), along with the level of TNF-alpha in the serum of patients with tuberculosis including pulmonary, miliary, and endobronchial tuberculosis, healthy controls, and pulmonary diseases such as diffuse interstitial lung disease (DILD) and pneumonia. AMs from patients with pulmonary tuberculosis did not produce a larger amount of TNF-alpha than did those from the healthy control subjects. However, among the patients with pulmonary tuberculosis, the AMs from the fresh and reactivated groups produced a larger amount of TNF-alpha than those from the inactive group. AMs from patients showing positivity in culture produced a larger amount of TNF-alpha than those showing negativity. The average level of serum TNF-alpha in patients with pulmonary tuberculosis was slightly higher than that of the healthy control group. Among patients with pulmonary tuberculosis, significantly increased levels of serum TNF-alpha were noted in the reactivated group compared to those of the fresh and inactive group. Patients with moderate to far-advanced infiltration on their chest X-rays, showed a significantly higher level of serum TNF-alpha than those with minimal involvement on the chest X-ray. Smokers from the healthy control group showed a significantly higher level of serum TNF-alpha than non-smokers from the same group. These results suggest that an increase in the production of TNF-alpha may correspond with the severity of pulmonary tuberculosis.
Bronchoalveolar Lavage Fluid/metabolism ; Humans ; Macrophages/metabolism ; Pulmonary Alveoli/metabolism ; Tuberculosis, Miliary/metabolism ; Tuberculosis, Pulmonary/etiology/*metabolism ; Tumor Necrosis Factor-alpha/*biosynthesis

The correlation between pulmonary endothelin receptors and alveolar-arterial oxygen gradient (A-aDO2) in rats with hepatopulmonary syndrome was investigated. Animals were divided into 2 groups: Sham-operated (Sham) group and common bile duct ligation (CBDL) group. Arterial blood gas was evaluated by a blood gas analyzer. The concentrations of ET-1 in blood and lung tissue sample were evaluated by radioimmunoassay. The distribution and expression of two kinds of subtype receptor of ET-1, ETRA and ETRB were examined by in situ hybridization. The results showed that the level of A-aDO2 was higher in CBDL group than that in Sham group (P < 0.05). The levels of plasma and pulmonary ET-1 in CBDL group were both higher than in Sham group (P < 0.05). There was no significant difference in average A of ETRA between two groups by imaging analysis (0.21 +/- 0.06 vs 0.22 +/- 0.08, P > 0.05), while that of ETRB was higher in CBDL group than in Sham group (0.58 +/- 0.16 vs 0.28 +/- 0.07, P < 0.05). The expression of ETRB in lung was positively correlated with A-aDO2 (P < 0.05). It was concluded that the widened A-aDO2 may be related with enhancement of the expression of ETRB in lung.
Endothelin-1/metabolism ; Hepatopulmonary Syndrome/*metabolism ; Lung/*metabolism ; Oxygen/*metabolism ; Pulmonary Alveoli/*metabolism ; Rats, Wistar ; Receptor, Endothelin A/metabolism ; Receptor, Endothelin B/*metabolism

OBJECTIVETo investigate the expression patterns of surfactant protein B (SP-B) and its role in the development of human fatal lung epithelial cells.

METHODSHuman fetal lung tissues were obtained from 37 fetuses of 10-34 weeks at abortion with parental consent and from two newborn infants who died of non-pulmonary causes. SP-B expression in the lung tissues was examined by immunohistochemistry.

RESULTSSP-B was detected in the cytoplasm of nonciliated columnar epithelial cells of the human fetal lung in as early as the 16th week of gestation. The positive reaction of SP-B was enhanced during canalicular stages and was more intense in the distal than in the proximal airway epithelium. From the 25th week to the prenatal stage, SP-B expression underwent no significant changes in the primitive alveolar stage, but increased remarkably after birth.

CONCLUSIONThe expression and secretion of SP-B reflects the maturation of the epithelial cells in human fatal lungs, and may closely associate with the survival ability of the newborn infants.

Cell Survival ; physiology ; Cells, Cultured ; Epithelial Cells ; cytology ; metabolism ; Fetus ; Humans ; Infant, Newborn ; Lung ; Pulmonary Alveoli ; cytology ; metabolism ; Pulmonary Surfactant-Associated Protein B ; biosynthesis ; physiology

OBJECTIVETo investigate the protective effect of curcumin (CU) on type II alveolar epithelial cells (A549 cells) during paraquat (PQ)-induced oxidative damage and its underlying mechanism.

METHODSRoutinely cultured A549 cells were divided into blank control group, CU control group, PQ group, and PQ+Cu group to receive respective treatments for 24 h. Cell viability was determined by MTT assay. The NFE2L2 expression in A549 cells was measured by RT-PCR and Western blot. The activities of the heme oxygenase-1 (HO-1) and NAD (P) H: quinone oxidoreductase 1 (NQO-1) in cells and the superoxide dismutase (SOD) and catalase (CAT) in supernatant, as well as malondialdehyde (MDA) content, were measured by enzyme-linked immunosorbent assay. After siRNA depletion of Nrf2, the protective effect of CU on A549 cells during PQ-induced oxidative damage was evaluated.

RESULTSPQ, even at a dose of 0.1 mmol/L, could significantly suppress the viability of A549 cells in a dose-dependent manner. CU showed no significant inhibitory effect on the viability of A549 cells when given at a dose below 160 ümol/L. Compared with the blank control group, the PQ group had significantly decreased SOD activity and significantly increased CAT activity and MDA content after 24-h exposure to 800 ümol/L PQ (P < 0.05 or P < 0.01). Thanks to pretreatment with 80 ümol/L CU, the PQ+CU group had significantly increased SOD and CAT activities and significantly decreased MDA content compared with the PQ group (P < 0.01). Compared with the blank control group, the PQ group had significantly increased expression of NFE2L2 and its downstream factors HO-1 and NQO-1 (P < 0.01), while the PQ+CU group had significantly higher expression of NFE2L2, HO-1,and NQO-1 than the PQ group (P < 0.01).Compared with the PQ+CU group, the CU+PQ+NFE2L2siRNA group had significantly decreased SOD and CAT activities and significantly increased MDA content (P < 0.01).

CONCLUSIONLow-dose CU significantly reduces the PQ-induced oxidative damage in A549 cells in vitro by activation of the Nrf2-ARE pathway.

Cell Line ; Curcumin ; pharmacology ; Humans ; NF-E2-Related Factor 2 ; metabolism ; Oxidation-Reduction ; Oxidative Stress ; Paraquat ; toxicity ; Pulmonary Alveoli ; cytology ; metabolism ; Reactive Oxygen Species ; metabolism ; Superoxide Dismutase ; metabolism

Irreversible destruction of bronchi and alveoli can lead to multiple incurable lung diseases. Identifying lung stem/progenitor cells with regenerative capacity and utilizing them to reconstruct functional tissue is one of the biggest hopes to reverse the damage and cure such diseases. Here we showed that a rare population of SOX9 basal cells (BCs) located at airway epithelium rugae can regenerate adult human lung. Human SOX9 BCs can be readily isolated by bronchoscopic brushing and indefinitely expanded in feeder-free condition. Expanded human SOX9 BCs can give rise to alveolar and bronchiolar epithelium after being transplanted into injured mouse lung, with air-blood exchange system reconstructed and recipient's lung function improved. Manipulation of lung microenvironment with Pirfenidone to suppress TGF-β signaling could further boost the transplantation efficiency. Moreover, we conducted the first autologous SOX9 BCs transplantation clinical trial in two bronchiectasis patients. Lung tissue repair and pulmonary function enhancement was observed in patients 3-12 months after cell transplantation. Altogether our current work indicated that functional adult human lung structure can be reconstituted by orthotopic transplantation of tissue-specific stem/progenitor cells, which could be translated into a mature regenerative therapeutic strategy in near future.
Bronchiectasis ; genetics ; metabolism ; Humans ; Pulmonary Alveoli ; cytology ; metabolism ; SOX9 Transcription Factor ; genetics ; metabolism ; Stem Cell Transplantation ; methods ; Stem Cells ; cytology ; metabolism

OBJECTIVEThis study examined the relationship between the ultrastructural alterations of alveolar epithelial cells type II (AEC-II) and pulmonary surfactant protein A (SP-A) levels in the lung tissue of young rats with acute lung injury (ALI) in order to explore the possible mechanism of ALI.

METHODSForty-eight young Sprague-Dawley rats were randomly divided into control and ALI groups. The rats in the ALI group were intraperitoneally injected with 4 mg/kg of lipopolysaccharide (LPS) in order to induce ALI. The control subjects were injected with the same volume of normal saline. Rats were sacrificed at 24, 48 and 72 hrs after LPS or NS injection. Lung samples were obtained from the lower parts of the left lung and fixed with 2.5% glutaraldehyde for transmission electron microscope examination and for Western blot test of SP-A.

RESULTSThe microvilli of AEC-II disappeared 24 hrs after LPS injection. After 24 and 48 hrs of LPS injection, lamellar body (Lb) increased in number, enlarged in size and reduced in density, and the ring-like arrangement of Lb was present. By 48 hrs after LPS injection, giant Lb with vacuole-like deformity appeared. The contents of lung SP-A in the ALI group 24 hrs (6.52+/-0.62 vs 5.02+/-0.35; P<0.01) and 48 hrs (6.65+/-0.62 vs 5.01+/-0.36; P<0.01) after LPS injection were significantly higher than those in the control group. By 72 hrs after LPS injection, Lbs ruptured and were reduced in number. The shape of the nuclei was irregular and the border was blurred. The content of lung SP-A was greatly reduced in the ALI group 72 hrs after LPS injection compared with that in the control group (3.87+/-0.50 vs 5.22+/-0.36; P<0.01).

CONCLUSIONSThe alterations of AEC-II and lung SP-A were time-dependent in young rats with ALI induced by LPS. In the early stage of ALI, the lung SP-A content showed a compensatory increase. With the increasing injury of AEC-II cells, the secretion of SP-A presented with a decompensation and the lung SP-A content decreased. This may be one possible mechanism for the development of ARD.

Animals ; Female ; Lipopolysaccharides ; toxicity ; Male ; Microscopy, Electron ; Pulmonary Alveoli ; pathology ; ultrastructure ; Pulmonary Surfactant-Associated Protein A ; analysis ; Rats ; Rats, Sprague-Dawley ; Respiratory Distress Syndrome, Adult ; metabolism ; pathology

Elastin is known to occur in the lung parenchyma and pleura as well as in the pulmonary vessels, but no detailed studies of this elastin's linkage between them have been done in three dimensions. For many years we have known that there is abundant elastin in the mammalian lungs, which may be associated with etiology of causing emphysema. We have developed selective casting methods to allow us to determine the location where elastin is found morphologically. The method involves casting either the vasculature via the right ventricle, or the airways via the trachea in the air sacs. Studies of the vasculature were done with the lung inflated to 80% of the vital capacity. The casted lungs were then put in 0.1 N NaOH at 75 degrees C for 48 hours, turning them frequently. THis method removed all non-elastin tissues. The scanning electron microscopy (SEM) was used to reveal the three dimensional pictures of elastin structures from both lung parenchyma and pulmonary vessels. Elastin was seen as fenestrated sheets and some fibers in both the vessels and the airways. Elastin in the two different locations was often interconnected. Studies on 6 dogs, 8 rabbits, and 2 pigs showed no significant species difference at the level of resolution of the SEM, which was used to study the specimens after they had been freeze-dried.
Animal ; Blood Vessels/metabolism/ultrastructure ; Corrosion Casting ; Dogs ; Elastin/*ultrastructure ; Lung/blood supply/*metabolism ; Microscopy, Electron, Scanning ; Pulmonary Alveoli/metabolism/ultrastructure ; Rabbits ; Swine

OBJECTIVETo investigate the effect of phenylephrine (an α-adrenergic agonist) on alveolar fluid clearance (AFC) in ventilator-induced lung injury and the possible mechanism involved.

METHODSA total of 170 male Wistar rats were randomly allocated into 17 groups (n=10) using random number tables. Short-term (40 minutes) mechanical ventilation with high tidal volume (HVT) was performed to induce lung injury, impair active Na+ transport and lung liquid clearance in the rats. Unventilated rats served as controls. To demonstrate the effect of phenylephrine on AFC, phenylephrine at different concentrations (1×10(-5), 1×10(-6), 1×10(-7), 1×10(-8), and 1×10(-9) mol/L) was injected into the alveolar space of the HVT ventilated rats. To identify the influence of adrenergic antagonists, Na(+) channel, and microtubular system on the effect of phenylephrine, phenylephrine at 1×10(-5) mol/L combined with prazosin (an α1-adrenergic antagonist, 1×10(-4) mol/L), yohimbine (an α2-adrenergic antagonist, 1×10(-4) mol/L), atenolol (a β1- adrenergic antagonist, 1×10(-5) mol/L), ICI-118551 (an β2-adrenergic antagonist, 1×10(-5) mol/L), amiloride (a Na+ channel blocker, 5×10(-4) mol/L), ouabain (a Na(+)/K(+)-ATPase blocker, 5×10(-4) mol/L), colchicine (a microtubular disrupting agent, 0.25 mg/100 g body weight), or β-lumicolchicine (an isomer of colchicine, 0.25 mg/100 g body weight) were perfused into the alveolar space of the rats ventilated with HVT for 40 minutes. AFC and total lung water content were measured.

RESULTSBasal AFC in control rats was (17.47±2.56)%/hour, which decreased to (9.64± 1.32)%/hour in HVT ventilated rats (P=0.003). The perfusion of phenylephrine at 1×10(-8), 1×10(-7), 1×10(-6), and 1×10(-5) mol/L significantly increased the AFC in HVT ventilated rats (all P<0.05). This effect of phenylephrine on AFC was suppressed by prazosin, atenolol, and ICI-118551 in HVT ventilated rats by 53%, 31%, and 37%, respectively (all P<0.05). The AFC-stimulating effect of phenylephrine was lowered by 33% and 42% with amiloride and ouabain, respectively (both P<0.05). Colchicine significantly inhibited the effect of phenylephrine (P=0.031).

CONCLUSIONPhenylephrine could increase the AFC in HVT-ventilated rats and accelerate the absorption of pulmonary edema.

Animals ; Male ; Phenylephrine ; therapeutic use ; Pulmonary Alveoli ; metabolism ; Rats ; Rats, Wistar ; Sodium-Potassium-Exchanging ATPase ; metabolism ; Ventilator-Induced Lung Injury ; drug therapy ; metabolism ; pathology