α1-Antitrypsin alleviates inflammation and oxidative stress by suppressing autophagy in asthma.

BACKGROUND: Asthma is considered an incurable disease, although many advances have been made in asthma treatments in recent years. Therefore, elucidating the pathological mechanisms and seeking novel and effective therapeutic strategies for asthma are urgently needed. METHODS: Airway resistance was measured by whole-body plethysmography. H&E staining was used to observe the morphological changes in the lung. Oxidative stress was assessed by measuring the levels of MDA, CAT and SOD. Gene expression was analysed by western blotting and RT-qPCR. ELISA was used to analyse the concentrations of IL-4, IL-5 and IFN-γ. RESULTS: In the present study, we successfully established in vivo and in vitro asthma models. OVA administration led to elevated lung resistance, cell counts in BALF, and cytokine secretion, impaired airway structure and enhanced oxidative stress and autophagy in a mouse model of asthma, while IL-13 induced inflammation, oxidative stress and autophagy in BEAS-2B cells. A1AT reduced lung resistance and cell counts in BALF and suppressed inflammation, oxidative stress and autophagy in a mouse model of asthma and IL-13-induced BEAS-2B cells. Mechanistic investigations revealed that autophagy activation compromised the protective effect of A1AT on IL-13-induced BEAS-2B cells. Further mechanistic studies revealed that A1AT alleviated inflammation and oxidative stress by inhibiting autophagy in the context of asthma. CONCLUSION: We demonstrated that A1AT could alleviate inflammation and oxidative stress by suppressing autophagy in the context of asthma and thus ameliorate asthma. Our study revealed novel pathological mechanisms and provided novel potential therapeutic targets for asthma treatment.

Resistin-like molecule ß acts as a mitogenic factor in hypoxic pulmonary hypertension via the Ca2+-dependent PI3K/Akt/mTOR and PKC/MAPK signaling pathways.

BACKGROUND: Pulmonary arterial smooth muscle cell (PASMC) proliferation plays a crucial role in hypoxia-induced pulmonary hypertension (HPH). Previous studies have found that resistin-like molecule ß (RELM-ß) is upregulated de novo in response to hypoxia in cultured human PASMCs (hPASMCs). RELM-ß has been reported to promote hPASMC proliferation and is involved in pulmonary vascular remodeling in patients with PAH. However, the expression pattern, effects, and mechanisms of action of RELM-ß in HPH remain unclear. METHODS: We assessed the expression pattern, mitogenetic effect, and mechanism of action of RELM-ß in a rat HPH model and in hPASMCs. RESULTS: Overexpression of RELM-ß caused hemodynamic changes in a rat model of HPH similar to those induced by chronic hypoxia, including increased mean right ventricular systolic pressure (mRVSP), right ventricular hypertrophy index (RVHI) and thickening of small pulmonary arterioles. Knockdown of RELM-ß partially blocked the increases in mRVSP, RVHI, and vascular remodeling induced by hypoxia. The phosphorylation levels of the PI3K, Akt, mTOR, PKC, and MAPK proteins were significantly up- or downregulated by RELM-ß gene overexpression or silencing, respectively. Recombinant RELM-ß protein increased the intracellular Ca2+ concentration in primary cultured hPASMCs and promoted hPASMC proliferation. The mitogenic effects of RELM-ß on hPASMCs and the phosphorylation of PI3K, Akt, mTOR, PKC, and MAPK were suppressed by a Ca2+ inhibitor. CONCLUSIONS: Our findings suggest that RELM-ß acts as a cytokine-like growth factor in the development of HPH and that the effects of RELM-ß are likely to be mediated by the Ca2+-dependent PI3K/Akt/mTOR and PKC/MAPK pathways.

Endoplasmic Reticulum Stress Induces HRD1 to Protect Alveolar Type II Epithelial Cells from Apoptosis Induced by Cigarette Smoke Extract.

BACKGROUND/AIMS: Cigarette smoking is a major risk factor of chronic obstructive pulmonary disease. This study aimed to examine the effects of cigarette smoke extract (CSE) on alveolar type II epithelial cells (AECII) and investigate the underlying mechanism. METHODS: Primary AECII were isolated from rat lung tissues and exposed to CSE. Apoptosis was detected by flow cytometry. Protein expression was detected by Western blot analysis. RESULTS: Primary rat AECII maintained morphological and physiological characteristic after 3 passages. CSE increased the expression of ER specific pro-apoptosis factors CHOP and caspase 12, and the phosphorylation of JNK in AECII. CSE activated ER stress signaling and increased the phosphorylation of PERK, eIF2α and IRE1. Furthermore, CSE induced the expression of Hrd1, a key factor of ER-associated degradation, in AECII. Knockdown of Hrd1 led to more than 2 fold increase of apoptosis, while overexpression of Hrd1 attenuated CSE induced apoptosis of AECII. CONCLUSIONS: Our results suggest that ER stress induces HRD1 to protect alveolar type II epithelial cells from apoptosis induced by CSE.

[Regulatory mechanism of Siah1 in the pathogenesis of rat hypoxic pulmonary hypertension].

OBJECTIVE: To explore the regulatory mechanism of Siahl in the pathogenesis of hypoxic pulmonary hypertension (HPH) in rats. METHODS: According to the random number table, 40 adult male Wistar rats were randomly divided into 5 groups (n = 8 each). And the animals were exposed to normoxia or hypoxia for 3, 7, 14 or 21 days respectively. The HPH model was established by normobaric intermittent hypoxia. Mean pulmonary arterial pressure (mPAP), ratio of vascular wall area to total vascular area (WA%), ratio of vascular lumen area to total vascular area (LA%) and right ventricle hypertrophy index (RVHI) were measured. The mRNA and protein relative levels of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) were detected by in situ hybridization and immunohistochemistry respectively. Reverse transcriptase-polymerase chain reaction ( RT-PCR) and in situ hybridization were used to determine the relative expressions of mRNA of hypoxia-inducible factor-1 (FIH) and Siahl. Immunohistochemistry and Western blot were employed to determine the relative expressions of proteins of FIH and Siahl. RESULTS: The levels of mPAP, WA% and LA% were significantly higher after 7-day hypoxia than those in normoxic control (21. 3 1. 6) vs (15. 9 ± 1. 3) mmHg (1 mmHg = 0. 133 kPa), (41.4 ± 2.8)% vs (35.0 ± 2.2)%, (58.6 ± 2.8)% vs (65.0 ± 2.2)%, all P <0.05). The level of RVHI was significantly higher after 14-day hypoxia than that in normoxic control ((27. 0 ± 1. 8) % vs (3. 2 ± 2. 1) %, P <0. 05). The relative expression of HIF-1α mRNA was significantly higher after 14-day hypoxia than that in normoxic control (0. 188 ± 0. 014 vs 0. 150 ± 0. 014, P < 0. 05). The relative expression of HIF-1α protein was significantly higher after 3-day hypoxia than that in normoxic control (0. 186 ± 0.014 vs 0. 067 ± 0.008, P <0.05). The relative levels of VEGF mRNA and protein were significantly higher after 7-day hypoxia than those in normoxic control (0. 152 ± 0. 019 vs 0. 057 ± 0. 007, 0. 176 ± 0. 017 vs 0. 083 ± 0. 010, both P <0. 05). The relative expression of FIH mRNA had little changes after exposure to hypoxia compared with normoxia. However the related expression of FIH protein was markedly lower after 7-day hypoxia than that in normoxic control (0. 166 ± 0. 015 vs 0. 200 ± 0. 017, P < 0. 05). The relative levels of Siahl mRNA and protein were markedly higher after 7-day hypoxia than those in normoxic control (0. 144 ± 0. 014 vs 0. 067 ± 0. 010, 0. 136 ± 0. 017 vs 0. 084 ± 0. 019, both P <0. 05). Linear correlation analysis showed that HIF-1α protein was positively correlated with the relative levels of VEGF mRNA and VEGF protein (r = 0. 545, 0. 523, both P <0. 01) while FIH protein was negatively correlated with the relative levels of VEGF mRNA and VEGF protein (r = -0. 785, -0. 788, both P < 0. 01). There was a positive correlation between the relative levels of Siahi mRNA and Siahl protein (r = 0. 823, P <0. 01) while a negative correlation existed between the relative levels of Siahl protein and FIH protein (r = -0. 671, P <0. 01). CONCLUSIONS: Under chronic hypoxia, Siahl is transcriptionally induced in pulmonary arterioles and it facilitates the degradation and decline of FIR in rats. And deceased FIH protein in pulmonary arterioles under hypoxia may attenuate its inhibitory effect on the transactivational activity of HIF-l a and promote the transactivation of such HIF-1α target gene as VEGF. Thus it is probably implicated in the pathogenesis of HPH.

Promoter methylation-mediated downregulation of PRDM5 contributes to the development of lung squamous cell carcinoma.

PRDM5 has been proposed as a tumor suppressor frequently downregualted in tumor. In this study, lung squamous cell carcinoma tissues and adjacent nontumorous normal tissues were collected from 30 patients. PRDM5 expression was detected by reverse transcription polymerase chain reaction and Western blot analysis, DNA methylation of PRDM5 promoter was analyzed by methylation-specific PCR. SK-MES-1 cells or xenografts in nude mice were treated with 5-aza-2'-deoxycitydine, and cell proliferation and tumor growth in nude mice were examined. We found that PRDM5 promoter was methylated and PRDM5 expression at both mRNA and protein levels was reduced in lung squamous cell carcinoma tissues. Furthermore, PRDM5 promoter methylation was significantly correlated with tumor differentiation and lymph node metastasis of lung squamous cell carcinoma, but not with age, gender, smoking, or tumor grade. 5-aza-2'-deoxycitydine inhibited the proliferation of SK-MES-1 cells and the growth of xenografts in nude mice, accompanied by reduced methylation of PRDM5 promoter and increased expression of PRDM5. Taken together, our data suggest that PRDM5 is a tumor suppressor in lung cancer and is a promising target for the diagnosis, prognosis, and therapy of lung squamous cell carcinoma.

Subarachnoid hemorrhage with Takotsubo syndrome as the prominent manifestation: A case and literature review.

Background: Takotsubo syndrome, which is often induced by physical or psychological stress, is typically a cardiac syndrome with transient left ventricular dysfunction in the absence of obstructive coronary artery disease. Subarachnoid hemorrhage with typical symptoms and signs is frequently reported, whereas the incidence of subarachnoid hemorrhage with Takotsubo syndrome as the prominent manifestation without a typical headache is rarely reported. Case description: We present a rare case of a 63-year-old male patient with cough and fever as the first manifestations, accompanied by mild dizziness, headache, and mental discomfort; however, the patient was eventually diagnosed with atypical subarachnoid hemorrhage with Takotsubo syndrome. The patient underwent general anesthesia downwards stent-assisted spring coil embolization and was discharged from the hospital after postoperative treatment consisting of anti-cerebrovascular spasm, anti-platelet aggregation, and cerebrospinal fluid replacement. Conclusion: This case demonstrates the association between Takotsubo syndrome and subarachnoid hemorrhage. When patients present with unexplained pulmonary edema with mild neurologic symptoms, clinicians should be alerted to subarachnoid hemorrhage and Takotsubo syndrome.

METTL3 Promotes Endothelium-Mesenchymal Transition of Pulmonary Artery Endothelial Cells by Regulating TRPC6/Calcineurin/NFAT Signaling Pathways.

Background: Endothelium-mesenchymal transition (EndMT) is a process of phenotypic and functional transition from activated endothelial cells to mesenchymal cells. Recently, EndMT has been proved to be one of the main pathological mechanisms of pulmonary artery hypertension (PAH). However, the molecular mechanism is not clear. Methods: Primary rat pulmonary arterial endothelial cells (rPAECs) were isolated from Sprague-Dawley rats and verified by CD31 immunofluorescence staining. rPAECs were exposed to hypoxic conditions to induce EndMT. RNA and protein levels in cells were detected by RT-qPCR and Western blot. The migration ability was verified by the transwell assay. The RIP experiment was used to test the m6A modification of TRPC6 mRNA and the binding relationship between TRPC6 and METTL3. Calcineurin/NFAT signaling was measured by using commercial kits. Results: METTL3 was found to be highly expressed by hypoxia treatment in a time-dependent manner. Knockdown of METTL3 significantly suppressed cell migration, downregulated the levels of interstitial cell-related markers like α-SMA and vimentin, and increased the levels of endothelial cell markers including CD31 and VE-cadherin. Mechanistically, METTL3 increased TRPC6 expression by enhancing the m6A modification of TRPC6 mRNA, thus activating calcineurin/NFAT signaling. Our experiments showed that METTL3 silencing mediated the inhibitory roles in the hypoxia-mediated EndMT process, which were significantly reversed by TRPC6/calcineurin/NFAT signaling activation. Conclusion: Our results elucidated that METTL3 knockdown inhibited the hypoxia-mediated EndMT process by inactivating TRPC6/calcineurin/NFAT signaling.

Curcumin Increased the Sensitivity of Non-Small-Cell Lung Cancer to Cisplatin through the Endoplasmic Reticulum Stress Pathway.

Objective: Non-small-cell lung cancer (NSCLC) is one of the most lethal cancers. Although cisplatin-based chemotherapies have been regarded as a promising treatment approach, cisplatin resistance still remains one of the major clinical challenges. Curcumin, a naturally occurring polyphenol, has been proved to increase chemotherapeutic efficiency of NSCLC cells. However, the role of curcumin in cisplatin-resistant NSCLC cells has been rarely investigated. This study aims to investigate whether curcumin enhances cisplatin sensitivity of human NSCLC cells and its underlying mechanisms. Method: A549/DDP and H1299/DDP cells were treated by DDP or/and curcumin before cell viability, and apoptosis were determined by using a CCK-8 assay and flow cytometer. The expressions of apoptosis and ER stress-related proteins, including cleaved caspase-3, cleaved PARP, CHOP, GRP78, XBP-1, ATF6, and caspase-4, were measured by the qPCR and western blotting. After cotreatment by DDP and curcumin, A549/DDP and H1299/DDP cells were further treated by the ER stress inhibitor, salubrinal (20 µm), after which the cell apoptosis and viability were detected. Result: Treatment by DDP and curcumin can substantially decrease cell viability, while can increase the cell apoptosis rate, elevate mRNA and protein expressions of apoptosis and ER stress-related proteins, compared with cells treated by DDP or curcumin alone. Salubrinal treatment can counteract the suppressive effect of DDP and curcumin on cell viability and decrease the cell apoptosis of A549/DDP and H1299/DDP cells. Conclusion: Curcumin can increase the sensitivity of NSCLC to cisplatin through an ER stress pathway and thus can be served as one of the molecular targets for overcoming the cisplatin resistance.

The role of endoplasmic reticulum stress in emphysema results from cigarette smoke exposure.

Apoptosis is of considerable importance in the pathogenesis of emphysema, and recent studies show that endoplasmic reticulum (ER) stress is involved in emphysema. In our research, we investigated the role of protein kinase RNA (PKR)-like ER kinase (PERK)/ eukaryotic initiation factor 2 alpha (eIF2α) pathway, the CCAAT enhancer-binding protein-homologous protein (CHOP) expression, caspase-12 activation and apoptosis in emphysema results from cigarette smoke (CS) exposure. Expression of phosphorylated-PERK (p-PERK), phospholated-eIF2α (p-eIF2α),CHOP and caspase-12 as well as the apoptosis rate are remarkably increased in rats after exposure to 2 months CS compared with control rats, significantly elevated in rats exposed to 4 months CS over rats exposed only to 2 months CS, and slightly decreased in ex-smoking rats in contrast to rats exposed to 4 months CS. Taken together, our results show that CS induces ER stress in lung epithelial cells, which may subsequently lead to lung injury in rats, and this might be a novel target for protection of pulmonary epithelial cells from ER stress injury in emphysema.

Heat shock protein 27 and cyclophilin A associate with the pathogenesis of COPD.

BACKGROUND AND OBJECTIVE: COPD is a global disease characterized by chronic bronchitis and obstructive emphysema. Its pathogenesis is not fully understood. This study aimed to use proteomics to provide new insights into the mechanisms of COPD. METHODS: Protein lysates were prepared from lung tissue samples harvested from never-smokers, non-COPD smokers and COPD smokers, and were analysed using 2-dimensional gel electrophoresis. Differentially expressed proteins were identified using mass spectrometry. The differential expression of heat shock protein 27 (Hsp27) and cyclophilin A (CyPA) was validated by immunohistochemistry and western blotting. RESULTS: Twenty-four proteins were identified by mass spectrometry as being differentially expressed among the three groups of subjects. The main functions of these proteins involve basic metabolism, oxidation/reduction, coagulation/fibrinolysis, protein degradation, signal transduction, inflammation and cell growth/differentiation/apoptosis. Proteomic analysis revealed that the expression of Hsp27 and CyPA was upregulated in smokers, and this upregulation was particularly marked in COPD smokers. The variation in expression of Hsp27 and CyPA between the groups was confirmed by immunohistochemistry and western blotting. CONCLUSIONS: Hsp27 and CyPA are associated with the pathogenesis of COPD, and smoking contributes to the overexpression of these proteins.

Good's syndrome with diffuse panbronchiolitis as the prominent manifestation: A case and literature review.

Good's syndrome (GS) is characterized by thymoma combined with adult-onset immunodeficiency. Diffuse panbronchiolitis (DPB) is a chronic inflammatory airway disease, which predominantly affects East Asians. Japanese scholars have reported extensively about GS combined with DPB or DPB-like pulmonary manifestation. However, such reports are rare in China. We report here a case of GS in China with DPB as the prominent manifestation and carry out a literature review accordingly. Our review indicates that in adults with DPB-like clinical manifestations, thymic lesions should be excluded and related immune function tests should be performed to exclude GS to avoid missed diagnosis and misdiagnosis.

CHOP overexpression sensitizes human non-small cell lung cancer cells to cisplatin treatment by Bcl-2/JNK pathway.

C/EBP homologous protein (CHOP), a 29 kDa cellular protein, plays a role in regulating tumor proliferation, differentiation, metabolism, cell death, and in tumor resistance to chemotherapy. Non-small cell lung cancer (NSCLC) is a tumor of the respiratory system and drug resistance is prevalent among NSCLC clinical cell cultures. Herein, our study elucidated the effect of CHOP on NSCLC cells with cisplatin resistance and its mechanism. In a NSCLC cell line with cisplatin-resistance, CHOP expression was decreased, compared with A549 cells. Overexpression of CHOP decreased the cell viability and enhanced cell apoptosis in the cells treated with cisplatin. Expression of CHOP also inhibited the cell proliferation and metastasis. CHOP increased the therapeutic effect of cisplatin on NSCLC cells through the Bcl-2/JNK pathway. In summary, CHOP regulated cisplatin resistance in cells of NSCLC by promoting the expression of apoptotic proteins and inhibiting the Bcl-2/JNK signaling pathway, indicating the antitumor effects of CHOP.

Positive correlation between PPARgamma/PGC-1alpha and gamma-GCS in lungs of rats and patients with chronic obstructive pulmonary disease.

Oxidative stress is one of the major pathogenesis of chronic obstructive pulmonary disease (COPD). gamma-Glutamylcysteine synthetase (gamma-GCS) is one of the paramount antioxidant enzymes in COPD. Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a ligand-activated transcription factor, which is activated by specific ligands such as rosiglitazone (RGZ), exerting multiple biological effects. PPARgamma coactivator-1alpha (PGC-1alpha) is a PPARgamma coactivator, which binds to PPARgamma by induction of PPARgamma ligands, co-activating PPARgamma target genes. Growing evidence has suggested that PPARgamma/PGC-1alpha can regulate multiple antioxidant genes. However, the effect of PPARgamma/PGC-1alpha on gamma-GCS during the development of COPD remains unclear. Here, we measured the expression levels of PPARgamma, PGC-1alpha and gamma-GCS, gamma-GCS activity and reactive oxygen species (ROS) contents in lungs of rats treated by cigarette smoke (CS) + lipopolysaccharide (LPS) and CS + LPS + RGZ, as well as lungs of patients suffered from COPD. Compared with lungs from CS + LPS-treated rats, lungs of RGZ-treated rats demonstrated markedly lower ROS contents, and remarkable increase of gamma-GCS activity and increase of the expression levels of PPARgamma, PGC-1alpha, and gamma-GCS. Furthermore, compared with controls, expression levels of PPARgamma, PGC-1alpha, and gamma-GCS significantly increased in the lungs of mild COPD patients, and progressively decreased in lungs of patients with moderate and severe COPD. gamma-GCS protein was positively correlated with FEV(1)%. PPARgamma and PGC-1alpha proteins were positively correlated with gamma-GCS activity and mRNA level. In conclusion, gamma-GCS showed compensatory upregulation in the early stage of COPD, which progressively decompensate with increasing COPD severity. The activation of the PPARgamma/PGC-1alpha pathway may protect against COPD progression by upregulating gamma-GCS and relieving oxidative stress.

Expression and role of factor inhibiting hypoxia-inducible factor-1 in pulmonary arteries of rat with hypoxia-induced hypertension.

Hypoxia-inducible factor-1alpha subunit (HIF-1alpha) plays a pivotal role during the development of hypoxia-induced pulmonary hypertension (HPH) by transactivating it' target genes. As an oxygen-sensitive attenuator, factor inhibiting HIF-1 (FIH) hydroxylates a conserved asparagine residue within the C-terminal transactivation domain of HIF-1alpha under normoxia and moderate hypoxia. FIH protein is downregulated in response to hypoxia, but its dynamic expression and role during the development of HPH remains unclear. In this study, an HPH rat model was established. The mean pulmonary arterial pressure increased significantly after 7 d of hypoxia. The pulmonary artery remodeling index became evident after 7 d of hypoxia, while the right ventricular hypertrophy index became significant after 14 d of hypoxia. The messenger RNA (mRNA) and protein expression of HIF-1alpha and vascular endothelial growth factor (VEGF), a well-characterized target gene of HIF-1alpha, were markedly upregulated after exposure to hypoxia in pulmonary arteries. FIH protein in lung tissues declined after 7 d of hypoxia and continued to decline through the duration of hypoxia. FIH mRNA had few changes after exposure to hypoxia compared with after exposure to normoxia. In hypoxic rats, FIH protein showed significant negative correlation with VEGF mRNA and VEGF protein. FIH protein was negatively correlated with mean pulmonary arterial pressure, pulmonary artery remodeling index and right ventricular hypertrophy index. Taken together, our results suggest that, in the pulmonary arteries of rat exposed to moderate hypoxia, a time-dependent decrease in FIH protein may contribute to the development of rat HPH by enhancing the transactivation of HIF-1alpha target genes such as VEGF.

TGF-ß1-induced SMAD2/3/4 activation promotes RELM-ß transcription to modulate the endothelium-mesenchymal transition in human endothelial cells.

Endothelial-to-mesenchymal transition (EndMT), which is characterized by increased proliferation, migration and invasion of endothelial cells, increased expression of mesenchymal markers and reduced expression of endothelial markers, has been reported to be closely related to the pathogenesis of several diseases, including pulmonary fibrosis. Resistin-like molecule-ß (RELM-ß), also known as "found in inflammatory zone 2″ (FIIZ2), plays an essential role in airway remodeling and pulmonary fibrosis; however, its role and mechanism in EndMT remain unclear. Herein, we used TGF-ß1-induced EndMT cell model in human umbilical vein endothelial cells (HUVECs) and human primary pulmonary artery endothelial cells (HPAECs) to investigate the function and mechanism of RELM-ß in TGF-ß1-induced EndMT in endothelial cell lines. We found that TGF-ß1 stimulation significantly upregulated RELM-ß expression; RELM-ß knockdown could attenuate TGF-ß1-induced cell proliferation and migration of endothelial cell lines and changes in protein levels of EndMT markers. SB432542, an inhibitor of SMADs, could partially reverse TGF-ß1-induced RELM-ß expression, endothelial cell migration and changes in EndMT marker protein levels. SMADs complex exerted its effects through SMAD2/3/4 complex mediating RELM-ß transcription. In conclusion, TGF-ß1 induces RELM-ß transcription to promote EndMT in HUVECs and HPAECs through activation of SMAD2/3/4; blocking SMADs-mediated RELM-ß transcription might ameliorate TGF-ß1-induced EndMT in endothelial cells.

The methylation profiles of PRDM promoters in non-small cell lung cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) is one of the leading malignant tumors worldwide. Aberrant gene promoter methylation contributes to NSCLC, and PRDM is a tumor suppressor gene family that possesses histone methyltransferase activity. This study aimed to investigate whether aberrant methylation of PRDM promoter is involved in NSCLC. MATERIALS AND METHODS: Primary tumor tissues, adjacent nontumorous tissues, and distant lung tissues were collected from 75 NSCLC patients including 52 lung squamous cell carcinoma (LSCC) patients and 23 lung adenocarcinoma patients. The expression of PRDMs was detected by polymerase chain reaction (PCR), Western blot, and immunohistochemical analysis. The methylation of PRDM promoters was detected by methylation-specific PCR. The correlation of methylation and expression of PRDMs with clinicopathological characteristics of patients were analyzed. RESULTS: mRNA expression of PRDM2, PRDM5, and PRDM16 was low or absent in tumor tissues compared to distant lung tissues. The methylation frequencies of PRDM2, PRDM5, and PRDM16 in tumor tissues were significantly higher than those in distal lung tissues. In LSCC patients, methylation of PRDM2 and PRDM16 was correlated with smoking status and methylation of PRDM5 was correlated with tumor differentiation. CONCLUSION: The expression of PRDM2, PRDM5, and PRDM16 is low or absent in NSCLC, and this is mainly due to gene promoter methylation. Smoking may be an important cause of PRDM2 and PRDM16 methylation in NSCLC.

[Reciprocal regulation between hypoxia-inducible factor-1alpha and its prolyl hydroxylases in hypoxic pulmonary hypertension rats].

OBJECTIVE: To investigate the interaction between hypoxia-inducible factors-1alpha subunit (HIF-1alpha) and its three prolyl hydroxylases (PHD1, PHD2 and PHD3) during the development of rat hypoxic pulmonary hypertension. METHODS: Forty male SD rats were randomly divided into 5 groups and exposed to normoxia (C group) or exposed to hypoxia for 3, 7, 14 or 21 d (H(3), H(7), H(14), H(21) group), respectively. Mean pulmonary arterial pressure (mPAP), vessel morphometry and right ventricle hypertrophy index (RVHI) were measured. Reverse transcriptase-polymerase chain reaction (RT-PCR) and in situ hybridization were used to determine the expression of mRNA. Immunohistochemistry and Western blot were used to determine the expression of mRNA. RESULTS: The level of mPAP [(21.7 +/- 2.4) mm Hg, 1 mm Hg = 0.133 kPa], the ratio of vascular wall thickness to external diameter [WA%, (43.9 +/- 5.3)%] and pulmonary artery media thickness [PAMT, (10.0 +/- 0.7) microm] were significantly higher in H(7) group than those in C group [(16.6 +/- 1.6) mm Hg, (36.3 +/- 4.8)% and (8.5 +/- 1.3) microm respectively, q value were 5.591, 4.082, 2.929, respectively, all P < 0.05]. These parameters reached a high level and remained stable on H(14) group, and RVHI was significantly higher in H(14) group [(27.6 +/- 1.4)%] than in C group [(23.6 +/- 2.9)%, q = 5.817, P < 0.05]. HIF-1alpha protein was barely positive in C group (0.080 +/- 0.009), but markedly up-regulated in H(3) group (0.196 +/- 0.018, compared with C group q = 18.864, P < 0.05), reaching its peak in H(7) group (0.203 +/- 0.022), and then declined slightly in H(14) and H(21) group. HIF-1alpha mRNA increased marginally in H(14) group (0.176 +/- 0.019, compared with C group q = 5.401, P < 0.05, 0.139 +/- 0.017). PHD1 and PHD2 mRNA (0.260 +/- 0.031, 0.196 +/- 0.023) and protein (0.244 +/- 0.030, 0.205 +/- 0.025) were positive in C group. PHD2 mRNA and protein were up-regulated in H(3) group (0.246 +/- 0.023, 0.235 +/- 0.025, compared with C group q value was 5.268, 3.046, respectively, all P < 0.05), reaching its peak in H(14) group whereas PHD1 protein declined in H(14) group (0.210 +/- 0.023, compared with C group q = 3.885, P < 0.05) without significant mRNA change. PHD3 mRNA and protein were detected at low level in C group (0.110 +/- 0.013, 0.153 +/- 0.019), but markedly up-regulated in H(3) group (0.259 +/- 0.024, compared with C group q = 15.831, P < 0.05), and then PHD3 mRNA remained at high level while PHD3 protein declined in H(14) and H(21) group (0.206 +/- 0.025, 0.189 +/- 0.019, compared with H(7) group q value was 6.441, 8.526, respectively, all P < 0.05). Linear correlation analysis showed that HIF-1alpha mRNA and protein were positively correlated with mPAP. There was a positive correlation between HIF-1alpha protein and PHD2, PHD3 mRNA (r value was 0.580, 0.690, respectively, all P value was 0.000) but a negative correlation between HIF-1alpha protein and PHD2 protein (r = -0.704, P < 0.05). CONCLUSIONS: HIF-1alpha was regulated mainly at the protein level during the development of hypoxic pulmonary hypertension. PHD2 and PHD3 are inducible by hypoxia, possibly via elevated HIF-1alpha, suggesting that a hypoxic up-regulation of PHD acts via feedback mechanism to attenuate hypoxia induced responses. PHD may also be regulated by posttranscriptional mechanisms.

[The relationship between the polymorphism of glutamate cysteine ligase modulatory subunit gene and the susceptibility to chronic obstructive pulmonary disease].

OBJECTIVE: To investigate whether glutamate cysteine ligase modulatory (GCLM) subunit gene polymorphism is associated with susceptibility to chronic obstructive pulmonary disease (COPD), and to study the relationship between polymorphism of GCLM gene with plasma gamma-glutamylcysteine synthetase (gamma-GCS) activity. METHODS: Blood samples of 104 stable phase COPD smokers (COPD group), 124 healthy smokers (C group) and 132 healthy never-smokers (H group) were collected, and then the genotypes of GCLM -588C/T and GCLM -23C/T polymorphism sites were detected by polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis (RFLP). The plasma gamma-GCS activity was measured by coupled enzyme procedure. RESULTS: (1) The distribution of -588CC, -588CT, -588TT genotypes were corresponding to -23GG, -23GT, -23TT respectively in all of the individuals. (2) The frequencies of -588CC genotype and -588 C allele were significantly lower in COPD group (62.3% and 79.2%) than in C group (84.7% and 91.9%) and H group (78.8% and 89.0%, P < 0.01). (3) In smokers, GCLM -588 T allele carried a higher risk to COPD, the odds ratio (OR value) to C allele was 3.0, and with a 95% confidence interval 1.7 - 5.3. (4) The plasma gamma-GCS activity was increased in C group [(282 +/- 58) U/mg.prot] and COPD group [(224 +/- 54) U/mg.prot] as compared with H group [(157 +/- 26) U/mg.prot, P < 0.01], and were higher in healthy smokers than in COPD smokers (P < 0.01). (5) The smokers with -588CC genotype had higher gamma-GCS activity than CT or TT genotype [(292 +/- 54), (225 +/- 45) U/mg.prot, P < 0.01 in C group and (245 +/- 52), (188 +/- 36) U/mg.prot, P < 0.01 in COPD group], but the difference did not exist in H group [(158 +/- 27), (153 +/- 25) U/mg.prot, P > 0.05]. CONCLUSION: The polymorphism of GCLM -588C/T and -23G/T sites were associated with susceptibility to COPD, and were associated with plasma gamma-GCS activity.

[Transforming growth factor beta1 correlates inducible nitric oxide synthase in pulmonary arteries of rats with hypoxia-induced pulmonary hypertension].

OBJECTIVE: To investigate the dynamic expression of transforming growth factor beta(1)(TGF-beta(1)) and inducible nitric oxide synthase (iNOS) in pulmonary arteries of rats with hypoxia-induced pulmonary hypertension (HPH). METHODS: Forty adult male Wistar rats were randomly divided into five groups: a control group (C group) and groups with hypoxia for 3, 7, 14 and 21 days (H(3), H(7), H(14), H(21) group), eight rats per group. Mean pulmonary arterial pressure (mPAP), vessel morphometry and right ventricle hypertrophy index (RVHI) were measured. Lungs were inflation fixed for in situ hybridization and immunohistochemistry. RESULTS: mPAP increased significantly in H(7) group [(18.41 +/- 0.37) mm Hg, 1 mm Hg = 0.133 kPa, P < 0.05], reaching its peak in H(14) group [(21.17 +/- 0.23) mm Hg], then remained at the high level. Hypoxia induced pulmonary artery remodeling and right ventricle hypertrophy index became evident in H(14) group. Expression of iNOS protein in control group (0.109 +/- 0.021) was weakly positive in pulmonary arterial tunica media, while the level of iNOS protein was markedly up-regulated in H(3) group (0.225 +/- 0.030, P < 0.01), reaching its peak in H(7) group (0.312 +/- 0.036), then remained at the high level. Expression of iNOS mRNA in C group (0.112 +/- 0.030) was weakly positive in pulmonary arterial wall, while the level of iNOS mRNA was markedly up-regulated in H(3) group (0.245 +/- 0.036), reaching its peak in H(7) group (0.318 +/- 0.034, P < 0.01), then remained at the high level. Expression of TGF-beta(1) protein in C group (0.042 +/- 0.012) was weakly positive, but the level of TGF-beta(1) protein was markedly up-regulated in H(3) group (0.198 +/- 0.031), reaching its peak in H(7) group (0.267 +/- 0.035, P < 0.01), and then tended to decline in H(14) and H(21) group. TGF-beta(1) mRNA staining was weakly positive in C group (0.145 +/- 0.018), H(3) group (0.163 +/- 0.021) and H(7) group (0.176 +/- 0.026), but began to increase significantly in H(14) group (0.385 +/- 0.028, P < 0.01), and then remained stable. TGF-beta(1) protein and mRNA were located predominantly in tunica adventitia and tunica media. Linear correlation analysis showed that TGF-beta(1) mRNA, iNOS mRNA and protein were positively correlated with mPAP, vessel morphometry and RVHI (r = 0.843 - 0.937, all P < 0.01). TGF-beta(1) protein (tunica adventitia) was negatively correlated with iNOS mRNA and protein (r = -0.856, -0.835, all P < 0.01). CONCLUSIONS: Interaction of TGF-beta(1) and iNOS plays a role in the pathogenesis of HPH in rats. iNOS can regulate the expression of TGF-beta(1) gene by NO. TGF-beta(1) can regulate the expression of iNOS gene by decreased stability and translation of iNOS mRNA and increased degradation of iNOS protein.