LncRNA PAXIP1-AS1 fosters the pathogenesis of pulmonary arterial hypertension via ETS1/WIPF1/RhoA axis.

Pulmonary arterial hypertension (PAH) is a life-threatening disease featured with elevated pulmonary vascular resistance and progressive pulmonary vascular remodelling. It has been demonstrated that lncRNA PAXIP1-AS1 could influence the transcriptome in PAH. However, the exact molecular mechanism of PAXIP1-AS1 in PAH pathogenesis remains largely unknown. In this study, in vivo rat PAH model was established by monocrotaline (MCT) induction and hypoxia was used to induce in vitro PAH model using human pulmonary artery smooth muscle cells (hPASMCs). Histological examinations including H&E, Masson's trichrome staining and immunohistochemistry were subjected to evaluate the pathological changes of lung tissues. Expression patterns of PAXIP1-AS1 and RhoA were assessed using qRT-PCR and Western blotting, respectively. CCK-8, BrdU assay and immunofluorescence of Ki67 were performed to measure the cell proliferation. Wound healing and transwell assays were employed to evaluate the capacity of cell migration. Dual-luciferase reporter assay, co-immunoprecipitation, RIP and CHIP assays were employed to verify the PAXIP1-AS1/ETS1/WIPF1/RhoA regulatory network. It was found that the expression of PAXIP1-AS1 and RhoA was remarkably higher in both lung tissues and serum of MCT-induced PAH rats, as well as in hypoxia-induced hPASMCs. PAXIP1-AS1 knockdown remarkably suppressed hypoxia-induced cell viability and migration of hPASMCs. PAXIP1-AS1 positively regulated WIPF1 via recruiting transcriptional factor ETS1, of which knockdown reversed PAXIP1-AS1-mediated biological functions. Co-immunoprecipitation validated the WIPF1/RhoA interaction. In vivo experiments further revealed the role of PAXIP1-AS1 in PAH pathogenesis. In summary, lncRNA PAXIP1-AS1 promoted cell viability and migration of hPASMCs via ETS1/WIPF1/RhoA, which might provide a potential therapeutic target for PAH treatment.

[Content determination of five flavonoids in Tibetan medicine Rhododendron anthopogonoides by quantitative analysis of multi-components by single marker (QAMS)].

To establish a quantitative analysis of multi-components by single marker(QAMS) method for five flavonoids in Rhododendron anthopogonoides and verify its feasibility and applicability in the medicinal materials of R. anthopogonoides. With hyperoside as the internal reference, relative correction factors(RCF) of rutin, quercetin, quercitrin and kaempferol were established by high-performance liquid chromatography(HPLC) analysis. RCFs were used to calculate the content of each component, system durability and relative retention time. Simultaneously, QAMS and external standard method(ESM) were used to determine the content of five flavonoids in 12 batches of R. anthopogonoides from different origins. The results were statistically analyzed to verify the accuracy and feasibility. The fingerprints and cluster analysis data of R. anthopogonoides analyzed and discussed differences among the batches. According to the results, the RCFs of rutin, quercetin, quercetin and kaempferol in R. anthopogonoides were 1.242 6, 0.990 5, 0.535 0, and 0.781 3, respectively. The RCFs represented a good reproducibility under different experimental conditions. Besides, there was no significant difference between QAMS and ESM. Besides, the fingerprint and cluster analysis data showed the consistency between the classification and with the origin distribution of the herbs. In conclusion, the QAMS method shows a good stability and accuracy in the quality control of R. anthopogonoides.

LncRNA-SMILR modulates RhoA/ROCK signaling by targeting miR-141 to regulate vascular remodeling in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a fatal progressive disease characterized by an increased blood pressure in the pulmonary arteries. RhoA/Rho-kinase (RhoA/ROCK) signaling activation is often associated with PAH. The purpose of this study is to investigate the role and mechanisms of long noncoding RNA (lncRNA) smooth muscle-induced lncRNA (SMILR) to activate the RhoA/ROCK pathway in PAH. SMILR, microRNA-141 (miR-141), and RhoA were identified by qRT-PCR in PAH patients' serum. 3-(4,5-Dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT), wound-healing assay, cell counting kit-8 (CCK-8) assay, and flow cytometry were performed to determine cell viability, migration, proliferation, and cell cycle in human pulmonary arterial smooth muscle cells (hPASMCs) and primary PASMCs from PAH patients. We also performed bioinformatical prediction, luciferase reporter assay, and RNA-binding protein immunoprecipitation (RIP) to assess the interaction among SMILR, miR-141, and RhoA. The RhoA/ROCK pathway and proliferation-related proteins were measured by Western blotting. Finally, we introduced the small hairpin (sh)SMILR to monocrotaline-induced PAH rat model and used the hemodynamic measurement, qRT-PCR, and immunohistochemistry to examine the therapeutic effects of shSMILR. SMILR and RhoA expression were upregulated, while miR-141 expression was downregulated in PAH patients. SMILR directly interacted with miR-141 and negatively regulated its expression. Knockdown of SMILR suppressed PASMC proliferation and migration induced by hypoxia. Furthermore, overexpression of miR-141 could inhibit the RhoA/ROCK pathway by binding to RhoA, thereby repressing cell proliferation-related signals. Knockdown of SMILR significantly inhibited the Rho/ROCK activation and vascular remodeling in monocrotaline-induced rats. Knockdown of SMILR effectively elevated miR-141 expression and in turn inhibited the RhoA/ROCK pathway to regulate vascular remodeling and reduce blood pressure in PAH.NEW & NOTEWORTHY Smooth muscle enriched long noncoding RNA (SMILR), as a long noncoding RNA (lncRNA), was increased in pulmonary arterial hypertension (PAH) patients and in vitro and in vivo models. SMILR activated RhoA/ROCK signaling by targeting miR-141 to disinhibit its downstream target RhoA. SMILR knockdown or miR-141 overexpression inhibited hypoxia-induced cell proliferation and migration via repressing RhoA/ROCK signaling in pulmonary arterial smooth muscle cells (PASMCs), which was confirmed in vivo experiments that knockdown of SMILR inhibited vascular remodeling and alleviated PAH in rats. SMILR may be a promising and novel therapeutic target for the treatment and drug development of PAH.

Determination of risk factors for predicting the onset of symptoms in asymptomatic COVID-19 infected patients.

Background: The number of asymptomatic infected patients with coronavirus disease 2019 (COVID-2019) is rampaging around the world but limited information aimed on risk factors of asymptomatic infections. The purpose of this study is to investigate the risk factors of symptoms onset and clinical features in asymptomatic COVID-19 infected patients. Methods: A retrospective study was performed in 70 asymptomatic COVID-2019 infected patients confirmed by nucleic acid tests in Hunan province, China between 28 January 2020 and 18 February, 2020. The epidemiological, clinical features and laboratory data were reviewed and analyzed. Presence or absence at the onset of symptoms was taken as the outcome. A Cox regression model was performed to evaluate the potential predictors of the onset of symptoms. Results: The study included 36 males and 34 females with a mean age of 33.24±20.40 years (range, 0.5-84 years). There were 22 asymptomatic carriers developed symptoms during hospitalization isolated observation, and diagnosed as confirmed cases, while 48 cases remained asymptomatic throughout the course of disease. Of 70 asymptomatic patients, 14 (14/70, 20%) had underlying diseases, 3 (3/70, 4.3%) had drinking history, and 11 (11/70, 15.7%) had smoking history. 22 patients developed symptoms onset of fever (4/22, 18.2%), cough (13/22, 59.1%), chest discomfort (2/22, 9.1%), fatigue (1/22, 4.5%), pharyngalgia (1/22, 4.5%) during hospitalization; only one (1/22, 4.5%) patient developed signs of both cough and pharyngalgia. Abnormalities on chest CT were detected among 35 of the 69 patients (50.7%) after admission, except for one pregnant woman had not been examined. 4 (4/70, 5.7%) and 8 (8/70, 11.4%) cases showed leucopenia and lymphopenia. With the effective antiviral treatment, all the 70 asymptomatic infections had been discharged, none cases developed severe pneumonia, admission to intensive care unit, or died. The mean time from nucleic acid positive to negative was 13.2±6.84 days. Cox regression analysis showed that smoking history (P=0.028, hazard ratio=4.49, 95% CI 1.18-17.08) and existence of pulmonary disease (P=0.038, hazard ratio=7.09, 95% CI 1.12-44.90) were risk factors of the onset of symptoms in asymptomatic carries. Conclusion: The initially asymptomatic patients can develop mild symptoms and have a good prognosis. History of smoking and pulmonary disease was prone to illness onset in asymptomatic patients, and it is necessary to be highly vigilant to those patients.

Targeting the RhoA-ROCK pathway to regulate T-cell homeostasis in hypoxia-induced pulmonary arterial hypertension.

BACKGROUND: Hypoxic pulmonary arterial hypertension (PAH) is a crippling disease with limited therapeutic methods. The imbalance of T helper 17 cell (Th17)/regulatory T cell (Treg) plays an important role in the development of Hypoxic PAH. However, whether targeting the ras homolog family member A-Rho kinase (RhoA-ROCK) pathway (activation and inhibition) by lysophosphatidic acid (LPA) and fasudil (FSD) regulate T-cell homeostasis in Hypoxic PAH remain unknown. OBJECTIVE: To examine the effects of LPA and FSD on hypoxic pulmonary vascular remodeling and homeostasis of Th17/Treg cells in Hypoxic PAH. METHODS: Rats were exposed to hypoxia (10 ±â€¯0.5% O2) to induce Hypoxic PAH. The experiments consists of two parts. Forty rats were randomly divided into four groups (n = 10): normoxia group, normoxia + LPA group, hypoxia group and hypoxia + LPA group. Thirty rats were randomly divided into another three groups (n = 10): normoxia group, hypoxia group, and hypoxia + FSD group. Rats in normoxia + LPA group and hypoxia + LPA group were intraperitoneally injected 40 µg/kg LPA daily. Rats in hypoxia + FSD group were intraperitoneally injected 30 mg/kg fasudil daily. The effects of LPA and FSD on the development of hypoxic PAH and right ventricle (RV) hypertrophy, on pulmonary vascular remodeling, and on changes of Th17/Treg cells and levels of interleukin-17 (IL-17) and IL-10 were examined. RESULTS: PAH and RV hypertrophy occurred in rats exposed to hypoxia. LPA exacerbated hypoxic pulmonary vascular remodeling and FSD inhibited it. LPA increased Th17/Treg imbalance in peripheral blood and spleen. However, after treatment with FSD, hypoxic PAH rats showed an obvious reduction of Th17 cells as well as an increase of Treg cells. LPA increased the expression of phosphorylated-signal transducer and activator of transcription 3 (p-STAT3) and reduced the p-STAT5 in peripheral blood and spleen in hypoxic PAH rats. The expression of p-STAT3 and p-STAT5 in hypoxic PAH rats treated with FSD showed opposite changes. LPA increased the expression of IL-17 and reduced the IL-10 in small intrapulmonary arteries and serum in hypoxic PAH. However, the expression of IL-17 and IL-10 in hypoxic PAH rats treated with FSD showed opposite changes. CONCLUSIONS: Activation and inhibition of RhoA-ROCK pathway by LPA and FSD modulated the homeostasis of Th17/Treg cells via regulating STAT3/STAT5 phosphorylation in hypoxic PAH. Thus, Apart from influence of pulmonary vascular remodeling, regulation of Th17/Treg homeostasis by RhoA-ROCK pathway play a key role in hypoxic PAH.

Intraperitoneal injection of cigarette smoke extract induced emphysema, and injury of cardiac and skeletal muscles in BALB/C mice.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a chronic, progressive, airway disease. In order to recognize mechanisms of COPD, various types of COPD animal models have been established, and the pathogenesis are different. The present study was designed to establish a COPD animal model by intraperitoneal injection of cigarette smoke extract (CSE) in BALB/C mice. METHODS: Mice were injected intraperitoneally with PBS/CSE and sacrificed at day 28. Pulmonary function, pathology of lung tissue, morphology of hearts and skeletal muscle, leukocytes count and antioxidant activity of bronchoalveolar lavage fluid (BALF), pulmonary parenchymal apoptosis index (AI), expression of cleaved caspase-3, expression of MMP-2 and MMP-9 mRNA, and activity of MMP-2 and MMP-9 in lung tissue were measured. RESULTS: Intraperitoneal injection of CSE induced pulmonary parenchymal destruction, pulmonary function reduction, leukocytes count, injury of cardiac and peripheral muscles, and increased pulmonary parenchymal AI, cleaved caspase-3 protein, expression of MMP-2 and MMP-9 mRNA, activity of MMP-2 and MMP-9 protein in lung tissue, and suppressed antioxidant activity in BALF (P < 0.05). CONCLUSIONS: Intraperitoneal injection of CSE produced emphysema, pulmonary parenchymal apoptosis, and injury of cardiac and skeletal muscles in mice. All pathobiologically relevant mechanisms in this model are shared with the COPD patients.

Detection of Pulmonary Hypertension by Combining Echocardiography and Chest Radiography.

RATIONALE AND OBJECTIVES: In pulmonary hypertension (PH) patients, chest radiographs often show an increase in the diameter of the right descending pulmonary artery (RDPA). The purpose of this study is to evaluate whether a combination of echocardiography and chest radiography for detecting PH is more accurate than echocardiography alone. MATERIALS AND METHODS: Between 2013 and 2019, a total of 1301 patients were included in this study. Among them, 1030 patients with congenital heart disease (CHD) were used to establish a linear regression model by combining echocardiographic and chest radiographic variables, and 136 CHD patients and 135 non-CHD patients were used to compare the accuracy between a new model and the 2015 ESC/ERS guidelines for right heart catheterization recommendation. The chest radiographic diameter of the RDPA, and the echocardiography-measured tricuspid regurgitation pressure gradient and the main pulmonary artery diameter were assessed. RESULTS: The TG-RDPA composite index correlated more strongly than either the TG or RDPA (r = 0.741 vs 0.709 or 0.544; both p value <0.001). The TG-RDPA composite index was more accurate in detecting PH than the ESC/ERS 2015 guidelines (overall accuracy: 83.8% vs 77.1%; missed diagnoses rate: 12.0% vs 22.5%). The overall accuracy of the main pulmonary artery-RDPA composite index (r = 0.599, p value <0.001) was 84.1% compared to overall accuracy of 77.1% using the ESC/ERS 2015 guidelines. CONCLUSION: A combination of echocardiography and chest X-ray may be a more accurate way to detect PH and an alternative method for suspected PH patients without tricuspid regurgitation velocity.

Differential Expression Profile of microRNAs and Tight Junction in the Lung Tissues of Rat With Mitomycin-C-Induced Pulmonary Veno-Occlusive Disease.

BACKGROUND: Pulmonary veno-occlusive disease (PVOD) is characterized by increased pulmonary vascular resistance. Currently, there is a lack of effective treatment. It is of great significance to explore molecular targets for treatment. This study investigated the differential expression profile of miRNAs and tight junction in the lung tissues of rats with mitomycin-C (MMC)-induced PVOD. METHODS: A total of 14 rats were divided into the control group and he PVOD group. We measured mean pulmonary arterial pressure (mPAP) and right ventricular hypertrophy index (RVHI). Pathological changes including those in lung tissues, pulmonary venules, and capillary were detected by H&E and orcein staining. Western blot was used to detect GCN2, ZO-1, occludin, and claudin-5 expression. We analyzed the miRNAs profile in the rat lung tissues by high-throughput sequencing. The top differentially expressed miRNAs were validated by using real-time polymerase chain reaction (RT-PCR). RESULTS: There were severe pulmonary artery hypertrophy/hyperplasia, thickening, and occlusion in the small pulmonary veins, pulmonary edema, and dilated capillaries in MMC-induced rats with PVOD. In addition, mPAP and RVHI were significantly increased (P < 0.05). The expression of GCN2 was significantly decreased (P < 0.05). A total of 106 differentially expressed miRNAs were identified. According to the fold changes, the top ten upregulated miRNAs were miRNA-543-3p, miRNA-802-5p, miRNA-493-3p, miRNA-539-3p, miRNA-495, miRNA-380-5p, miRNA-214-5p, miRNA-539-5p, miRNA-190a-3p, and miRNA-431. The top 10 downregulated miRNAs were miRNA-201-3p, miRNA-141-3p, miRNA-1912-3p, miRNA-500-5p, miRNA-3585-5p, miRNA-448-3p, miRNA-509-5p, miRNA-3585-3p, miRNA-449c-5p, and miRNA-509-3p. RT-PCR confirmed that miRNA-214-5p was upregulated, while miRNA-141-3p was downregulated (P < 0.05). Functional analysis showed various signaling pathways and metabolic processes, such as fatty acid biosynthesis, tight junction, and the mTOR signaling pathway. In addition, the expression of the tight junction-related protein of ZO-1, occludin, and claudin-5 was significantly decreased in rats with PVOD (P < 0.05). CONCLUSION: miRNAs may be involved in the pathogenesis of PVOD. Furthermore, ZO-1, occludin, and claudin-5 verification confirmed that the tight junction may be involved in the development of the disease.

Clustering cases of Chlamydia psittaci pneumonia mimicking COVID-19 pneumonia.

BACKGROUND: The onset symptoms of people infected by Chlamydia psittaci can mimic the coronavirus disease 2019 (COVID-19). However, the differences in laboratory tests and imaging features between psittacosis and COVID-19 remain unknown. AIM: To better understand the two diseases and then make an early diagnosis and treatment. METHODS: Six patients from two institutions confirmed as psittacosis by high-throughput genetic testing and 31 patients confirmed as COVID-19 were retrospectively included. The epidemiology, clinical characteristics, laboratory tests and computed tomography (CT) imaging features were collected and compared between the two groups. The follow-up CT imaging findings of patients with psittacosis were also investigated. RESULTS: The white blood cell count (WBC), neutrophil count and calcium were more likely to be decreased in patients with COVID-19 but were increased in patients with psittacosis (all P = 0.000). Lymphocyte count and platelet count were higher in patients with psittacosis than in those with COVID-19 (P = 0.044, P = 0.035, respectively). Lesions in patients with psittacosis were more likely to be unilateral (P = 0.001), involve fewer lung lobes (P = 0.006) and have pleural effusions (P = 0.002). Vascular enlargement was more common in patients with COVID-19 (P = 0.003). Consolidation in lung CT images was absorbed in all 6 patients. CONCLUSION: Psittacosis has the potential for human-to-human transmission. Patients with psittacosis present increased WBC count and neutrophil count and have specific CT imaging findings, including unilateral distribution, less involvement of lung lobes and pleural effusions, which might help us to differentiate it from COVID-19.

Atorvastatin attenuates inflammatory infiltration and vascular remodeling in lung of hypercholesterolemia rabbits.

Hypercholesterolemia contributes to cardiovascular diseases, but its direct effect on lung is little known. 3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) have been shown to exert numerous effects that are dependent and independent of their cholesterol-lowering property. The authors hypothesized that atorvastatin would attenuate hypercholesterolemia-induced lesion in lung. Fifteen rabbits were randomly divided into control group, high-cholesterol forage group, and atrovastatin treatment group. Body weight and blood lipid were measured. All lung tissue and pulmonary arteries were collected for histopathology and immunohistochemistry. Alveolar macrophages (AMs) were cultured and activation of nuclear factor (NF)-κB was detected. Concentrations of interleukin (IL)-6 were measured in serum, bronchoalveolar lavage fluid (BALF), and culture supernatants of AMs. Total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) of high-cholesterol forage group were higher than control group (P < .05). There were infiltrating of AMs and lymphocytes in lung tissue of high-cholesterol forage group. NF-κB activity in AMs and concentrations of IL-6 in serum, BALF, and culture supernatants of AMs were higher than those of control group (P < .01), and so were all vascular remodeling indexes. TC and LDL-C and other indexes of atrovastatin treatment group were decreased (P < .05). Hypercholesterolemia induced pulmonary inflammatory Infiltration and vascular remodeling. Atorvastatin attenuated inflammatory infiltration and vascular remodeling in lung of hypercholesterolemia rabbits.

Abnormal pulmonary artery systolic pressure response after exercise in systemic sclerosis patients: A PRISMA-compliant meta-analysis.

BACKGROUND: Pulmonary artery systolic pressure (PASP) is an important parameter for detecting pulmonary arterial hypertension (PAH). The difference between rest PASP and post-exercise PASP (ΔPASP) may play a role in predicting and screening resting PAH. The aim of this study is to analyze ΔPASP in systemic sclerosis (SSc) patients with PAH or non-PAH and suggest a cutoff value of ΔPASP for detection of PAH. METHODS: PubMed, Embase, and Web of Science were searched for relevant publications up to July 7, 2018. Characteristics of control, no PAH, exercise-induced PAH (EIPH) and PAH subgroups in SSc patients were extracted. R 3.5.0 with the "meta" package was used to conduct this meta-analysis. RESULTS: Twelve articles involving 1279 patients were included in this study. The subgroups meta-analysis showed pooled mean ΔPASP in different subgroups: control group (8.6 mmHg, 95% CI: 6.9-10.5), no PAH group (12.2 mmHg, 95% CI: 11.2-13.2), EIPH group (26.0 mmHg, 95% CI: 24.2-27.7) and PAH group (36.2 mmHg, 95% CI: 29.7-42.7). CONCLUSION: Combining the results of our study with the previous studies, an abnormal increase in PASP after exercise could indicate the development of PAH in SSc patients. In addition, if ΔPASP>29 mmHg, a high suspicion of PAH should be raised.

Inhibition of tumor necrosis factor-alpha reduces alveolar septal cell apoptosis in passive smoking rats.

BACKGROUND: Recent studies have revealed that lung cell apoptosis plays an important role in pathogenesis of cigarette-induced chronic obstructive pulmonary disease (COPD). Tumor necrosis factor alpha (TNF-alpha) is one of the most important cytokines which are involved in COPD. This study aimed at investigating the influence of its inhibitor, recombinant human necrosis factor-alpha receptor II:IgG Fc fusion protein (rhTNFR:Fc) on alveolar septal cell apoptosis in passive smoking rats. METHODS: Forty-eight rats were randomly divided into a normal control group, a passive smoking group, an rhTNFR:Fc intervention group and a sham intervention group. The passive smoking rats were treated by exposure to cigarette smoking daily for 80 days. After smoking for one month the rhTNFR:Fc intervention group was treated with rhTNFR:Fc by subcutaneous injection, the sham intervention group injected subcutaneously with a neutral preparation (normal saline 0.1 ml, manicol 0.8 ml, cane sugar 0.2 mg, Tris 0.024 mg as a control. Lung function was determined and the levels of TNF-alpha in serum and broncho-alveolar lavage fluid (BALF) were measured with enzyme-linked immunosorbnent assay (ELISA). Lung tissue sections stained by hematoxylin and eosin (HE) were observed for study of morphological alternations. Mean linear intercept (MLI) and mean alveolar numbers (MAN) were measured and the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method was carried out to determine the percentage of positive cells and distribution of apoptotic cells. RESULTS: Increased MLI and decreased MAN were found in the passive smoking group compared with both the normal control group and the rhTNFR:Fc intervention group (P < 0.05). Forced expiratory volume in 0.3 second (FEV 0.3)/forced vital capacity (FVC) and peak expiratory flow (PEF) were lower in the passive smoking group than that in the normal control group (P < 0.05). Compared with the sham intervention group, FEV 0.3/FVC and PEF increased in the rhTNFR:Fc intervention group (P < 0.05). The levels of TNF-alpha in serum were higher in the passive smoking group than that in the normal control group (P < 0.05) and rhTNFR:Fc intervention group (P < 0.05). Significant differences were found between the levels of TNF-alpha in the serum of the rhTNFR:Fc intervention group and sham intervention group (P < 0.05). The levels of TNF-alpha in BALF were higher in the passive smoking group than that in the normal control group (P < 0.05), but no significant differences of TNF-alpha levels in BALF were found between the passive smoking group and rhTNFR:Fc intervention group. The number of TUNEL positive cells in alveolar septa was significantly increased in the passive smoking group as compared with the normal control group and the rhTNFR:Fc intervention group (P < 0.05). CONCLUSION: This study provides preliminary evidence that rhTNFR:Fc may interfere with TNF-alpha and reduce alveolar septal apoptosis in smoking rats.

Statins may ameliorate pulmonary hypertension via RhoA/Rho-kinase signaling pathway.

Statins are the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors that function as potent inhibitors of cholesterol biosynthesis and have been used for many years for the treatment of hypercholesterolemia. However, accumulating experimental and clinical studies have revealed that the health benefits associated with statins treatment, particularly those conferred on the cardiovascular system, were the cholesterol-independent. Because statins inhibit an early step in the cholesterol biosynthetic pathway, they also inhibit the synthesis of isoprenoids such as farnesylpyrophosphate and geranylgeranylpyrophosphate, which are important postranslational lipid attachments for intracellular signaling molecules such as the Rho GTPases. The isoprenylation of Rho is a prerequisite for Rho activation, facilitating its interaction with the plasma membrane, undergoing GDP-GTP exchange and be activated. Inhibition of RhoA geranylgeranylation by statins decreases membrane GTP-bound active RhoA and subsequent Rho-kinase activity. Activated RhoA via its downstream effector Rho-kinase is involved in a wide range of cellular functions, such as cell migration, proliferation and apoptosis. Recently, rising evidences suggested that RhoA/Rho-kinase pathway was essentially involved in various models of pulmonary hypertension and statins effectively ameliorated pulmonary hypertension. Based on this findings, we hypothesis that statins attenuate pulmonary hypertension via RhoA/Rho-kinase signaling pathway in vivo.

Rho-kinase as a potential therapeutic target for the treatment of pulmonary hypertension.

Pulmonary hypertension (PH) is a cardiovascular disorder characterized by vasoconstriction and vascular remodeling. Recently, rapidly increasing evidence from various rat models of PH and patients with PH suggest that small GTPase Rho and its downstream effector, Rho-kinase, play a key role in the pathogenesis of PH. Activation of the Rho/Rho-kinase pathway is important for pulmonary endothelial dysfunction, pulmonary vascular smooth muscle cell contractility, proliferation and apoptosis in PH. A greater Rho-kinase expression and an enhanced Rho-kinase activity have been observed in pulmonary arteries of PH rats, such as hypoxia-induced, monocrotaline-induced and genetic spontaneous PH rats. Moreover, Y-27632 or fasudil, the selective Rho-kinase inhibitors, significantly attenuated PH in various pulmonary hypertensive model rats and patients with PH, but did not reduce systemic blood pressure. Therefore, Rho-kinase inhibitors may have therapeutic potential for the treatment of PH.

[Clinical observation and expression of C-reactive protein by LPS-induced A549 cells in patients with chronic obstructive pulmonary disease].

OBJECTIVE: To investigate the level of mRNA expression of C-reactive proteins (CRP) induced by LPS in human alveolar type epithelial cell line, A549. METHODS: Sputum and plasma specimens were obtained from patients with chronic obstructive pulmonary disease (COPD) diagnosed according to the national criteria. CRP was measured by enzyme-linked immunosorbent assays (ELISA). A549 cells were incubated with lipopolysaccharide (LPS) at different concentrations and for different time. CRP mRNA was extracted from cells and the expression was analyzed by RT-PCR. The CRP in the supernatant was measured by ELISA. RESULTS: The concentration of CRP in the sputum of patients with COPD was significantly higher than that in the plasma (P < 0.05). LPS at different concentrations and for different time induced the expression and secretion of CRP in A549 with a time-dependent increase and the expression of CRP were significantly higher than those of the control (P < 0.05 - 0.01). CONCLUSION: Self-secretion of CRP in the respiratory tract may exist. A549 induced by LPS may express CRP mRNA.

[C-reactive protein level and the correlation between lung function and CRP levels in patients with chronic obstructive pulmonary diseases].

OBJECTIVE: To investigate the changes of C-reactive protein (CRP) level in patients with chronic obstructive pulmonary diseases (COPD) and to analyze the correlation between the lung function and CRP levels. METHODS: Sputum and serum specimens were obtained from 30 COPD patients diagnosed according to the national criteria. The CRP level was measured by enzyme-linked immunosorbent assays. The lung function indexes such as the forced expiratory volume in one second (FEV1) and the forced expiratory volume in one second/forced vital capacity (FEV1/FVC) were also determined. RESULTS: The sputum CRP level in COPD patients was 30-50 times higher than that of the health controls. The sputum CRP level in COPD patients is significantly higher than that of serum in these patients (P < 0.05). The correlation between changes of serum and sputum CRP levels and sputum CRP levels was positive (r = 0.625, P < 0.05). The correlations between changes of serum CRP levels and FEV1 were negative (r = -0.610, -0.725, respectively, P < 0.001). And the correlations between changes of serum and sputum CRP levels and FEV1/FVC were negative (r = -0.639, -0.600, respectively, P < 0.05). CONCLUSION: The CRP may be secreted from the local respiratory tract. The damage of lung function in COPD patients is associated with the increase of CRP level.

[Effects of atorvastatin on LPS-induced PGE2 and IL-6 secretions in human pulmonary epithelial cells].

OBJECTIVE: To investigate the effects of atorvastatin on LPS-induced PGE2 and IL-6 secretions in human pulmonary epithelial cells (A549). METHODS: The supernates of LPS-induced cultured human pulmonary epithelial cells from different intervention groups were collected to measure the concentrations of PGE2 and IL-6 by enzyme-linked immunosorbent assay. RESULTS: The concentrations of PGE2 and IL-6 in supernates of LPS-induced human pulmonary epithelial cells were significantly higher than those in the control group (P < 0.05) at different time-points. The concentrations of PGE2 and IL-6 in supernates of atorvastatin intervention groups at different levels were significantly lower than those in non-intervention group (P < 0.05). CONCLUSION: Atorvastatin decreased LPS-induced PGE2 and IL-6 secretions in human pulmonary epithelial cells (A549), which suggests that statins have anti-inflammatory properties on human pulmonary epithelial cells.

Atorvastatin reduces lipopolysaccharide-induced expression of C-reactive protein in human lung epithelial cells.

Accumulating evidence suggests that statins possess anti-inflammatory properties and may decrease C-reactive protein (CRP) levels in plasma. However, no studies have as yet addressed whether or not statins regulate the expression of CRP in human lung epithelial cells (A549). In this study, we determined whether atorvastatin modulates the lipopolysaccharide (LPS)-induced expression of CRP in A549 cells. A549 cells were incubated in Dulbecco's modified Eagle's medium containing LPS in the absence or presence of various concentrations of atorvastatin. After incubation, the medium was collected and the amount of CRP was measured by an enzyme-linked immunosorbent assay. The cells were harvested and CRP messenger ribonucleic acid (mRNA) was analyzed by reverse transcription polymerase chain reaction. Incubation with LPS induced a significant time- and dose-dependent increase in CRP mRNA expression and CRP production in A549 cells, whereas atorvastatin significantly decreased LPS-induced CRP mRNA expression and CRP production in a dose-dependent manner. The present study revealed that A549 cells are capable of LPS-induced CRP expression, and that atorvastatin down-regulates the LPS-induced expression of CRP in cultured A549 cells. Our results suggest that statins ameliorate lung inflammation by regulating CRP production in human lung epithelial cells.