Mitochondrial citrate accumulation drives alveolar epithelial cell necroptosis in lipopolysaccharide-induced acute lung injury.

Necroptosis is the major cause of death in alveolar epithelial cells (AECs) during acute lung injury (ALI). Here, we report a previously unrecognized mechanism for necroptosis. We found an accumulation of mitochondrial citrate (citratemt) in lipopolysaccharide (LPS)-treated AECs because of the downregulation of Idh3α and citrate carrier (CIC, also known as Slc25a1). shRNA- or inhibitor-mediated inhibition of Idh3α and Slc25a1 induced citratemt accumulation and necroptosis in vitro. Mice with AEC-specific Idh3α and Slc25a1 deficiency exhibited exacerbated lung injury and AEC necroptosis. Interestingly, the overexpression of Idh3α and Slc25a1 decreased citratemt levels and rescued AECs from necroptosis. Mechanistically, citratemt accumulation induced mitochondrial fission and excessive mitophagy in AECs. Furthermore, citratemt directly interacted with FUN14 domain-containing protein 1 (FUNDC1) and promoted the interaction of FUNDC1 with dynamin-related protein 1 (DRP1), leading to excessive mitophagy-mediated necroptosis and thereby initiating and promoting ALI. Importantly, necroptosis induced by citratemt accumulation was inhibited in FUNDC1-knockout AECs. We show that citratemt accumulation is a novel target for protection against ALI involving necroptosis.

Role of Epigenetics in the Pathogenesis, Treatment, Prediction, and Cellular Transformation of Asthma.

Asthma is a mysterious disease with heterogeneity in etiology, pathogenesis, and clinical phenotypes. Although ongoing studies have provided a better understanding of asthma, its natural history, progression, pathogenesis, diversified phenotypes, and even the exact epigenetic linkage between childhood asthma and adult-onset/old age asthma remain elusive in many aspects. Asthma heritability has been established through genetic studies, but genetics is not the only influencing factor in asthma. The increasing incidence and some unsolved queries suggest that there may be other elements related to asthma heredity. Epigenetic mechanisms link genetic and environmental factors with developmental trajectories in asthma. This review provides an overview of asthma epigenetics and its components, including several epigenetic studies on asthma, and discusses the epigenetic linkage between childhood asthma and adult-onset/old age asthma. Studies involving asthma epigenetics present valuable novel approaches to solve issues related to asthma. Asthma epigenetic research guides us towards gene therapy and personalized T cell therapy, directs the discovery of new therapeutic agents, predicts long-term outcomes in severe cases, and is also involved in the cellular transformation of childhood asthma to adult-onset/old age asthma.

Role of Sex Hormones at Different Physiobiological Conditions and Therapeutic Potential in MBD2 Mediated Severe Asthma.

Sex hormone has become a "hot topic" to evaluate the hormonal therapeutic potential in severe asthma. Th17 cell is one of the main influencing factors involved in the pathogenesis of severe asthma, hence also called as kernel of severe asthma, and Th17 subtype of non-T2 asthma is less responsive (resistance) to inhaled corticosteroid (ICS), so severe in nature. Methyl-CpG binding domain protein 2 (MBD2) is overexpressed and regulates the Th17 differentiation, showing the possibility of therapeutic target in treating Th17 mediated severe asthma. Sex hormone fluctuates at the different physiobiological conditions of the human body and affects the asthma pathobiology showing its role in asthma prevalence, severity, remission, and therapy. This review briefly overviews the sex hormones, their influence in asthma at the different physiobiological conditions of human body, and MBD2 severe asthma connection with the possible therapeutic potential of sex steroids in MBD2 mediated Th17 predominant severe asthma. Male sex hormone tends to show a beneficial effect and possibly downregulates the expression of Th17 cells via regulating MBD2 through a mechanism distinct from corticosteroid treatment and guides us towards discovery of new therapeutic agent, reduces the asthma-related complications, and promotes long-term survival by lowering the risk of therapy-resistant issues of old age severe asthma.

A COX-2/sEH dual inhibitor PTUPB alleviates lipopolysaccharide-induced acute lung injury in mice by inhibiting NLRP3 inflammasome activation.

Rationale: Dysregulation of arachidonic acid (ARA) metabolism results in inflammation; however, its role in acute lung injury (ALI) remains elusive. In this study, we addressed the role of dysregulated ARA metabolism in cytochromes P450 (CYPs) /cyclooxygenase-2 (COX-2) pathways in the pathogenesis of lipopolysaccharide (LPS)-induced ALI in mice. Methods: The metabolism of CYPs/COX-2-derived ARA in the lungs of LPS-induced ALI was investigated in C57BL/6 mice. The COX-2/sEH dual inhibitor PTUPB was used to establish the function of CYPs/COX-2 dysregulation in ALI. Primary murine macrophages were used to evaluate the underlying mechanism of PTUPB involved in the activation of NLRP3 inflammasome in vitro. Results: Dysregulation of CYPs/COX-2 metabolism of ARA occurred in the lungs and in primary macrophages under the LPS challenge. Decrease mRNA expression of Cyp2j9, Cyp2j6, and Cyp2j5 was observed, which metabolize ARA into epoxyeicosatrienoic acids (EETs). The expressions of COX-2 and soluble epoxide hydrolase (sEH), on the other hand, was significantly upregulated. Pre-treatment with the dual COX-2 and sEH inhibitor, PTUPB, attenuated the pathological injury of lung tissues and reduced the infiltration of inflammatory cells. Furthermore, PTUPB decreased the pro-inflammatory factors, oxidative stress, and activation of NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome in LPS-induced ALI mice. PTUPB pre-treatment remarkably reduced the activation of macrophages and NLRP3 inflammasome in vitro. Significantly, both preventive and therapeutic treatment with PTUPB improved the survival rate of mice receiving a lethal dose of LPS. Conclusion: The dysregulation of CYPs/COX-2 metabolized ARA contributes to the uncontrolled inflammatory response in ALI. The dual COX-2 and sEH inhibitor PTUPB exerts anti-inflammatory effects in treating ALI by inhibiting the NLRP3 inflammasome activation.

PTUPB ameliorates high-fat diet-induced non-alcoholic fatty liver disease via inhibiting NLRP3 inflammasome activation in mice.

Non-alcoholic fatty liver disease (NAFLD) affects 25% of the global adult population, and no effective pharmacological treatment has been found. Products of arachidonic acid metabolism have been developed into a novel therapy for metabolic syndrome and diabetes. It has been demonstrated that protective actions of a novel dual cyclooxygenase-2 (COX-2) and soluble epoxide hydrolase (sEH) inhibitor, PTUPB, on the metabolic abnormalities. Here, we investigated the effects of PTUPB on hepatic steatosis in high-fat diet (HFD)-induced obese mice, as well as in hepatocytes in vitro. We found that PTUPB treatment reduced body weight, liver weight, liver triglyceride and cholesterol content, and the expression of lipolytic/lipogenic and lipid uptake related genes (Acc, Cd36, and Cidec) in HFD mice. In addition, PTUPB treatment arrested fibrotic progression with a decrease of collagen deposition and expression of Col1a1, Col1a3, and α-SMA. In vitro, PTUPB decreased palmitic acid-induced lipid deposition and downregulation of lipolytic/lipogenic genes (Acc and Cd36) in hepatocytes. Additionally, we found that PTUPB reduced the production of pro-inflammatory cytokines and suppressed the NLRP3 inflammasome activation in HFD mice and hepatocytes. In conclusion, dual inhibition of COX-2/sEH attenuates hepatic steatosis by inhibiting the NLRP3 inflammasome activation. PTUPB might be a promising potential therapy for liver steatosis associated with obesity.

Alanylglutamine Relieved Asthma Symptoms by Regulating Gut Microbiota and the Derived Metabolites in Mice.

OBJECTIVE: Allergic asthma is a chronic inflammatory disease, which seriously affects the life quality of patients, especially children. Alanylglutamine is a nutritional supplement with potential protective and anti-inflammatory effects, but its function in allergic asthma remains elusive. In this study, we focused on the investigations of the roles and functional mechanism of Alanylglutamine in asthma. METHODS: Ovalbumin (OVA) induction was utilized to establish a mouse asthma model. 16S rDNA sequencing was performed to compare the diversity of intestinal microorganisms under different treatments. Gas chromatography was utilized to screen the intestinal microbe-short-chain fatty acids in the stool. The lung tissue was extracted to determine signaling pathways, including AMPK, NF-κB, mTOR, STAT3, IKKß, TGF-ß, and IL-1ß through Western blot or RT-qPCR. RESULTS: It was observed that Alanylglutamine reduced the cytokine in OVA-induced allergic asthma mice. H&E staining showed obvious pneumonia symptoms in the asthma group, while Alanylglutamine alleviated the inflammatory infiltration. Alanylglutamine reversed gut microbiota compositions in OVA-induced allergic asthma mice and enhanced the butyric acid level. The protective role of Alanylglutamine may be associated with the gut microbiota-butyric acid-GPR43 pathway in asthma mice. In contrast to the OVA group, Alanylglutamine activated the protein expression of P-AMPK/AMPK and inhibited the protein expression of P-mTOR/mTOR, P-P65/P65, P-STAT3/STAT3, P-IKKß/IKKß, TGF-ß, and IL-1ß, with similar effects from butyric acid. CONCLUSION: The results indicated that Alanylglutamine might be beneficial for asthma, and its effect was achieved through the regulation on microbiota and the derived metabolites. The therapeutic effects might be associated with AMPK, NF-κB, mTOR, and STAT3 signaling pathways. These findings will help identify effective therapeutic direction to alleviate allergic inflammation of the lungs and airways.

Vasoactive intestinal peptide suppresses the NLRP3 inflammasome activation in lipopolysaccharide-induced acute lung injury mice and macrophages.

Vasoactive intestinal peptide (VIP) is a neuropeptide that exerts anti-inflammatory functions. We have reported that VIP mediated by lentivirus attenuates acute lung injury (ALI) in lipopolysaccharide (LPS)-induced murine model. However, the exact role of VIP in uncontrolled inflammation during ALI is largely unknown. Accumulating evidence indicates that the NLRP3 inflammasome has a critical role during ALI. In this study, we investigated the effects of VIP on the activation of NLRP3 inflammasome during the development of ALI in mice. Seven days after the intratracheal injection of VIP-lentivirus, a murine ALI model was induced by intratracheal injection of LPS. VIP-lentivirus significantly reduced the expression of NLRP3 inflammasome components in lung tissue, including NLRP3, pro-caspase-1, pro-IL-1ß, and pro-IL-18. VIP-lentivirus also inhibited the formation of caspase-1 p10 and the maturation of IL-1ß and IL-18. In vitro, exogenous VIP pre-treatment inhibited the priming of NLRP3 inflammasome in murine primary peritoneal macrophages, indicated by down-regulation of expression of NLRP3 inflammasome components. VIP pre-treatment effectively prevented the LPS-induced degradation of I-κB and the synthesis of the downstream of NF-κB, including TNF-α and IL-17A. Furthermore, VIP pre-treatment pronouncedly suppressed the autoproteolysis of caspase-1 and the secretion of IL-1ß and IL-18 induced by LPS plus ATP in macrophages. In addition, VIP inhibited the generation of reactive oxygen species in macrophages by decreasing NOX1 and NOX2 expression. These findings illustrate one mechanism that VIP attenuates ALI induced by LPS through inhibiting the activation of the NLRP3 inflammasome and encourage further studies assessing the therapeutic potential of VIP to ALI.

The effect of pollutional haze on pulmonary function.

Detrimental health effects of atmospheric exposure to ambient particulate matter (PM) have been investigated in numerous studies. Exposure to pollutional haze, the carrier of air pollutants such as PM and nitrogen dioxide (NO2) has been linked to lung and cardiovascular disease, resulting increases in both hospital admissions and mortality. This review focuses on the constituents of pollutional haze and its effects on pulmonary function. The article presents the available information and seeks to correlate pollutional haze and pulmonary function.

[Effects of different cultivation practices on composition, carbon and nitrogen distribution of soil aggregates in farmlands.] / ä¸åŒæ ½åŸ¹ç®¡ç†æ¨¡å¼å¯¹å†œç”°åœŸå£¤å›¢èšä½“ç»„æˆåŠå ¶ç¢³ã€æ°®åˆ†å¸ƒçš„å½±å“.

The long-term experiments were conducted at two locations with different soil fertility. There were four treatments, including super high-yielding cultivation treatment (SH), high-yielding and high efficiency cultivation treatment (HH), local farmer's practice (FP), and control (CK), respectively. The field experiments were established to study the effects of different cultivation practices on composition, carbon and nitrogen distribution of tillage layer soil aggregates in different soil fertility, with the aim of proposing technological approaches to enhance soil fertility and achieve the sustainable development of increasing yield and efficiency in wheat-maize ecosystem. The results indicated that compared with treatments in low soil fertility (LSF), same treatments in high soil ferti-lity (HSF) had the higher mean mass diameter and geometric mean diameter, contents of organic carbon and total nitrogen, and lower fractal dimension in dried soil aggregates at soil tillage layer, which was beneficial to the formation and stability of large aggregate. Optimizing application of NPK fertilizers and the application of combined chemical fertilizer with organic fertilizer could increase the diameter of soil aggregate, reduce the fractal dimension of aggregate and promote the formation and stability of large aggregates, and the effect on HSF was greater than that on LSF; also they could improve the content and distribution of organic carbon and total nitrogen in large soil aggregate, the contribution rate to >5 mm aggregate in LSF was greater than in HSF, while the contribution rate to 5-0.5 mm aggregates in HSF was greater than in LSF.

[Characteristics of farmland eco-environment at the intercropping stage of maize intercropped with winter wheat and their effects on seedling growth of summer maize].

To study the farmland eco-environment of intercropping maize with wheat at the intercropping stage and its influence on maize seedling growth, two summer maize cultivars, Zhengdan 958 and Denghai 661, were either intercropped with wheat or directly seeded. The result demonstrated that there was little difference for the soil water content of the farmland between the two cultivation methods. The highest soil temperature of intercropped maize was 4.8-5.2 °C lower than the soil temperature of directly-seeded maize, and the lowest temperature of the intercropped maize was 1.4-1.7 °C lower. But, the temperatures for both planting methods met the requirement for seed germination. Light intensity on the ground surface of the intercropped maize was 4.4%-10.6% less than natural light, and insufficient light was the main reason for the weak and late seedling. Compared to the directly-seeded maize, the speeds of seed germination and accumulation of dry matters of the intercropped maize were relatively slow. On the whole, the seedling of intercropped maize was not strong, which presented small leaves, short height and low chlorophyll content. The restraint on the growth of intercropped maize was enhanced with the extension of intercropping period. For farm planting, direct-seeding could improve the seed germination and seedling growth of summer maize.

Effects and mechanism of arsenic trioxide on reversing the asthma pathologies including Th17-IL-17 axis in a mouse model.

In traditional Chinese medicine, arsenous compounds, including arsenic trioxide (ATO), are often used to treat many diseases, which are safe and effective. Recently, studies have indicated that Th17- IL-17 involved in the pathogenesis and development of asthma. The goal of this study was to investigate the effect and mechanism of ATO on asthma, especially the Th17- IL-17 axis.We used oval bumin (OVA)-immunized mice as a model for asthma and treated mice with ATO or dexamethasone. The mice were then monitored airway responsiveness, airway inflammation, mucus production, IL-17 levels in BALF and the positive rate of Th17 cells. In vitro, CD4+ T cells from splenic cell suspensions were separated and purified. We measured the expression of IL-17 and caspase-12 protein in purified CD4+ T cells, and detected IL-17 levels in CD4+ T lymphocyte culture solution with or without ATO. Moreover, apoptosis, mitochondrial membrane potential, cytosolic calcium were analyzed. We found that ATO could reduce airway responsiveness, airway inflammation, mucus hyperplasia, the expression of IL-17 in BALF and the positive rate of Th17 cells at a level comparable to treatment with DXM. In vitro data suggested that ATO can induce CD4+ T cells apoptosis, cause mitochondrial dysfunction, Ca2+ overload and promote caspase-12 activation. Our study suggested that ATO had potential medical value for the treatment of human asthma..

ß-arrestin2 stimulates interleukin-17 production and expression of CD4+ T lymphocytes in a murine asthma model.

Allergic asthma is a complex and chronic inflammatory airway disease. Interleukin-17 is a pro-inflammatory cytokine which plays critical role in the pathogenesis of allergic asthma. It has been reported that ß-arrestin2 regulated the development of allergic asthma at a proximal step in the inflammatory cascade. In this study, the influence of ß-arrestin2 on Interleukin-17 production and expression of CD4+ T lymphocytes in a murine asthma model was investigated. Splenic CD4+ T lymphocytes from wild-type mice and those from a murine asthma model were purified. CD4+ T lymphocytes from a murine asthma model were transfected with siRNAs targeting the ß-arrestin2 or were pretreated with the ERK1/2 inhibitor, PD98059. After stimulation, the protein expression of ß-arrestin2、phosphorylated-ERK1/2 and IL-17 were detection by Western blot; the mRNA expression of IL-17 were detected by real-time PCR; the accumulation of IL-17 in supernatants were detected by ELISA. We found that ß-arrestin2、phosphorylated-ERK1/2 and IL-17 expression in CD4+ T lymphocytes from a murine asthma model were increased compared with those from wild-type mice (p < 0.01). Treatment of CD4+ T lymphocytes with siRNAs targeting the ß-arrestin2 down-regulated phosphorylated- ERK 1/2 and IL-17 expression (p < 0.01). PD98059 decreased IL-17 production and expression in CD4+ T lymphocytes in a murine asthma model (p < 0.05). We conclude that ß-arrestin2 stimulated IL-17 production and expression of CD4+ T lymphocytes in a murine asthma model. The effect was partly mediated by ERK 1/2 activation. Targeting ß-arrestin2 biological activity could be a valid therapeutic approach for the treatment of allergic asthma.

[The effects of Tumstatin185-191 on lung adenocarcinoma cell lines and the association with protein kinase B and extracellular regulated protein kinase activation].

OBJECTIVE: to investigate the antitumor effects of tumstatin185-191 as a single agent or combination with cisplatin (DDP) on non-small lung cancer (NSCLC) cell lines A549. In addition, the changes of the protein kinase B(Akt) and extracellular regulated protein kinase (ERK) in cultured NSCLC cells treated by tumstatin185-191 and cisplatin were evaluated. METHODS: A549 cells were treated with tumstatin185-191 and cisplatin. Cell viability was assessed using the modified 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell apoptosis was measured by flow cytometry. The activation of Akt and Erk were evaluated by Western blotting. RESULTS: Tumstatin185-191 inhibited the proliferation of A549 and the IC(50) values of tumstatin 185-191 was 73.7 micromol/L. After cotreatment with 20 micromol/L tumstatin185-191, IC(50) values of cisplatin in A549 cells reduced from 5.2 micromol/L to 3.5 micromol/L, while 40 micromol/L tumstatin185-191 reduced from 5.2 micromol/L to 1.4 micromol/L. The early apoptosis rate was (19.34 +/- 0.97)% in the cotreatment group, (12.5 +/- 2.1)% in cisplatin group and (9.6 +/- 1.6)% in tumstatin185-191 group (F = 5.74, P < 0.01). The levels of phospho-Akt (p-Akt) and phospho-ERK (p-ERK) in the A549 cells were remarkably lower after being treated with tumstatin 185-191, while tumstatin 185-191 treatment whether alone, or in combination with cisplatin, had the similar effects on the protein levels of p-Akt and p-ERK in A549 cells. CONCLUSION: our data suggest that tumstatin185-191 might enhance the sensitivity of A549 cells to cisplatin. The effects of promoting apoptosis and downregulation of proliferation induced by tumstatin185-191 may be mediated through inactivation of the Akt and ERK pathways.

[Tumstatin185-191 increases the sensitivity to cisplatin in a cisplatin-resistant human lung adenocarcinoma cell line].

OBJECTIVE: To investigate the effects and related mechanisms of Tumstatin 185-191 as a single agent or in combination with cisplatin on proliferation and apoptosis in a cisplatin-resistant human lung adenocarcinoma cell line A549-DDP cells. METHODS: A549-DDP cells were treated with Tumstatin185-191 and cisplatin at varying concentrations. Cell viability was assessed by a modified 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. 50% inhibiting concentration (IC(50)) values of the chemotherapeutic drugs were analyzed by MTT assay. Cell apoptosis was measured by flow cytometry. The activation of Akt and ERK was evaluated by Western blotting. RESULTS: Tumstatin185-191 inhibited the proliferation of A549-DDP cells and its IC(50) value was 80.25 micromol/L. After cotreatment with 20 micromol/L Tum185-191, the IC(50) value of cisplatin in A549-DDP cells reduced from 77.16 micromol/L to 57.97 micromol/L, the reverse index was 1.33, while with 40 micromol/L Tumstatin185-191 the IC(50) was reduced from 77.16 to 26.40 micromol/L and the reverse index was 2.92. The early apoptosis rate was 19.5% +/- 1.1% in the cotreatment group, while 13.3% +/- 1.5% in cisplatin group and 10.2% +/- 2.0% in Tum185-191 group (F = 4.09, P < 0.05). The levels of phospho-Akt (p-Akt) and phospho-ERK (p-ERK) in the A549-DDP cells were remarkably lower after treatment with Tumstatin 185-191. The Tumstatin 185-191 treatment alone or in combination with cisplatin had a similar effect on the protein levels of p-Akt and p-ERK in A549-DDP cells. CONCLUSION: Our data suggest that Tumstatin185-191 may promote apoptosis, downregulate proliferation and partly reverse the drug resistance of A549-DDP cells to cisplatin. The effects induced by Tum185-191 may be mediated through inactivation of the Akt and ERK pathways.

[Effect of cyclooxygenase-2 on vascular endothelial cell apoptosis induced by cigarette smoke extract].

OBJECTIVE: To explore the effect of cyclooxygenase-2 on vascular endothelial cell apoptosis induced by cigarette smoke extract. METHODS: Human vascular endothelial cells (ECV-304) were cultured in vitro, and those at the exponential growth phase were studied in experiments. The experiment was completed through 3 steps: (1) ECV-304 cells were cultured with 0.0%, 0.5%, 1.0% and 5.0% CSE for 12 h. (2) ECV-304 cells were exposed to 5.0% CSE for 0, 3, 6, 9, 12 and 24 h. (3) Endothelial cells were treated by 5% CSE, together with different concentrations of selective COX-2 inhibitor celecoxib (0.0, 2.5, 5.0, 10.0, 20.0, 50.0 micromol/L concentrations) for 9 h. The cell apoptosis rate was tested by Hoechst staining and flow cytometry methods, and the expression of COX-2 protein by immunocytochemistry and Western blotting. RESULTS: CSE induced ECV-304 cell apoptosis and COX-2 expression in a dose-dependent manner. The apoptosis rate of ECV-304 cells with 5.0% CSE was the highest (5.40+/-0.39)%. CSE- induced COX-2 expression reached the highest level with 5.0% CSE (206.1+/-15.5), the differences being significant (F=90.03, 159.94, all P<0.05). Furthermore CSE induced both apoptosis rate and COX-2 expression time-dependently, with the apoptosis rate achieving the peak after 24 h (8.87+/-0.41)%, while COX-2 expression reached the highest level at 9 h. The selective COX-2 inhibitor celecoxib inhibited COX-2 protein expression partially and augmented cell apoptosis induced by CSE. CONCLUSIONS: CSE induces endothelial cell apoptosis and increases the expression of COX-2 protein in vascular endothelial cells. Celecoxib, the selective COX-2 inhibitor, reduces the expression of COX-2 protein and promotes cell apoptosis induced by CSE in vascular endothelial cells. COX-2 may play an important role in protecting development of CSE-associated apoptosis of endothelial cells.

[Apoptosis of alveolar epithelial cells and pulmonary vascular endothelial cells in chronic obstructive pulmonary disease].

OBJECTIVE: To investigate the relationship between apoptosis of alveolar epithelial cells and pulmonary vascular endothelial cells in chronic obstructive pulmonary disease (COPD) and the relationship between apoptosis and lung function and emphysema. METHODS: Twenty-four male Sprague-Dawley rats were randomly divided into a smoke exposure group (COPD group) and a normal control group (NC group). The rat model of COPD was established by exposure to cigarette smoke for 80 days, and lung tissues were obtained. Lung tissue samples were also collected respectively from patients with COPD (n = 13) and without COPD (n = 12). Lung sections stained by HE were observed to study the morphological alteration, and mean linear intercept (MLI) and mean alveolar numbers (MAN) were measured to estimate the extent of emphysema in rats. Quantitative analysis of apoptosis of alveolar epithelial cells and pulmonary vascular endothelial cells was undertaken by TdT-mediated dUTP nick end labeling (TUNEL). The data distributed normally were expressed as (-x) +/- s, and the independent-samples t-test was used for comparison of means. Nonparametric data were expressed as median (quartile range), and Wilcoxon rank sum test was used for comparison. Correlation between apoptosis of the two kinds of cells in patients with COPD was estimated by Spearman rank correlation coefficients, and the correlations between the specific indexes, such as FEV(1)%Pre, FEV(1)/FVC(%), residual volume/total lung capacity(%) [RV/TLC(%)], MLI, MAN, and the cell apoptosis were also investigated. Statistical difference was accepted at P < 0.05. RESULTS: Destruction of alveolar walls and enlargement of alveolar space were observed as pathological changes of lung tissues from patients and rats with COPD. The apoptotic index (AI) of alveolar epithelial cells and pulmonary vascular endothelial cells were (28.9 +/- 3.1)%, (13.2 +/- 2.6)% in patient COPD group; (10.0 +/- 1.0)%, (4.1 +/- 0.4)% in rat COPD group; the differences being significant (t = -23.946, -8.820, -24.273, -36.422, all P < 0.05), as compared with NC groups [(5.8 +/- 1.2)%, (5.6 +/- 1.5)%, (2.1 +/- 0.4)%, (0.2 +/- 0.1)% respectively]. In patient COPD group, the AI of alveolar epithelial cells was significantly higher than that of pulmonary vascular endothelial cells (t = -13.889, P < 0.05) and both were positively correlated with each other (r = 0.60, P < 0.05). In patient COPD group, both the apoptosis of alveolar epithelial cells and pulmonary vascular endothelial cells revealed negative correlations to FEV(1)(%)pre (r = -0.83, -0.69, all P < 0.05) and FEV(1)/FVC(%) (r = -0.95, -0.71, all P < 0.05), but positive correlations were demonstrated between them and RV/TLC(%) (r = 0.93, 0.70, all P < 0.05). In rat COPD group, MLI of lung tissue showed a positive correlation with the AI of alveolar epithelial cells (r = 0.59, P < 0.05) while MAN a negative correlation with the latter (r = -0.81, P < 0.05). CONCLUSIONS: Abnormal apoptosis of alveolar epithelial cells and pulmonary vascular endothelial cells was present in patients and rats with COPD, which was related to the changes of lung function or pathological changes of lung tissues. The results suggest that the abnormal changes of apoptosis of pulmonary tissue in COPD may be involved in the pathogenesis of the disease.