Long noncoding RNA NSCLCAT1 increases non-small cell lung cancer cell invasion and migration through the Hippo signaling pathway by interacting with CDH1.

Metastatic growth is the leading cause of cancer-related death in non-small cell lung cancer (NSCLC). Metastasis is believed to be initiated by an increase in cell motility mediated by the loss of cell-cell adhesion because of the suppression of E-cadherin [encoded by cadherin 1 ( CDH1)]. However, very little is known about the molecular mechanism of CDH1 regulation. Therefore, we hypothesized that non-small cell lung cancer-associated transcript-1 (NSCLCAT1) suppresses functional CDH1 and mediates the Hippo signaling pathway, resulting in increased cell migration and invasion, and reduced apoptosis. Initially, microarray profiling and target prediction programs were employed to identify whether NSCLCAT1 targets CDH1. Next, quantitative PCR was used to determine the expression pattern of NSCLCAT1 in 114 specimens. The biologic functions of NSCLCAT1 in NSCLC were assessed through the up-regulation and down-regulation of the levels of endogenous NSCLCAT1 with the use of NSCLCAT1 vector or small interfering RNA against NSCLCAT1 in NSCLC cells. Furthermore, the Hippo signaling pathway in NSCLC cells was blocked by applying the verteporfin treatment to have a better understanding on the pivotal role of the Hippo signaling pathway in NSCLC. Microarray expression profiles of long noncoding RNAs, GSE19804 and GSE27262), revealed that NSCLCAT1 was up-regulated in NSCLC. Among patients with NSCLC, we determined that the NSCLCAT1 was robustly induced, whereas CDH1 was suppressed. The luciferase activity determination identified CDH1 as a NSCLCAT1 target. NSCLCAT1 was found to increase cell viability, migration, and invasion and to reduce apoptosis in NSCLC cells. The results from the quantitative PCR and Western blot analysis revealed that NSCLCAT1 modulated the Hippo signaling pathway. Furthermore, the inhibition of the Hippo signaling pathway by verteporfin treatment led to the loss of the effect of NSCLCAT1 on NSCLC cells. In summary, our findings suggested that NSCLCAT1 potentially has a role in NSCLC and NSCLCAT1-mediated regulation of the Hippo signaling pathway through the transcriptional repression of CDH1; therefore, the functional suppression or inhibition of NSCLCAT1 could be used as a novel therapeutic pathway in the control of aggressive and metastatic NSCLC.-Zhao, W., Zhang, L.-N., Wang, X.-L., Zhang, J., Yu, H.-X. Long noncoding RNA NSCLCAT1 increases non-small cell lung cancer cell invasion and migration through the Hippo signaling pathway by interacting with CDH1.

Involvement of the TLR4/NF-κB Signaling Pathway in the Repair of Esophageal Mucosa Injury in Rats with Gastroesophageal Reflux Disease.

BACKGROUND/AIMS: Numerous studies have highlighted the activation of NF-κB in the esophageal mucosa during the early stages of gastroesophageal reflux disease (GERD). The present study aimed to investigate the role of the TLR4/NF-κB signaling pathway in GERD rat models. METHODS: Wistar rats (n = 60) were recruited to establish a GERD animal model. Distal esophageal pH was assessed, followed by determination of the contents of thiobarbituric acid-reactive species (TBARS) and reactive oxygen species (ROS) in esophageal mucosa homogenate. ELISA was employed to detect the levels of inflammatory factors (IL-6, IL-8, IL-10 and TNF-α) in esophageal mucosa. The expression of MMP-3, MPP-9, Cldn1 and Cldn4 was determined by immunohistochemistry. RT-qPCR and western blot analysis were applied to evaluate the protein expressions in TLR4/NF-κB signaling pathway, while TUNEL staining was utilized to examine the apoptosis rate in the esophageal mucosal tissues. RESULTS: Distal esophageal pH of the rats was higher in the GERD + PDTC group than in other groups. Levels of inflammatory factors in esophageal mucosal tissues were downregulated with the inhibition of NF-κB, which was determined to be associated with the decreased contents of TBARS and ROS. Moreover, decreased MMP-3 and MPP-9 in addition to elevated Cldn1 and Cldn4 were detected in the esophageal mucosa as a result of the inactivation of NF-κB. The TLR4/NF-κB signaling pathway-related proteins (TLR4, NF-κB and IκBα); the rate of apoptosis was demonstrated to be suppressed in the GERD + PDTC group, while inactivating NF-κB was found to alleviate the tissue damage observed in the esophageal mucosa. CONCLUSION: The key findings of the current study demonstrate that the inactivation of the TLR4/NF-κB signaling pathway alleviates oxidative stress injury and promotes the repair of esophageal mucosal injury among rats with GERD, highlighting a potential novel GERD mechanism.

1-(1-acetyl-piperidin-4-yl)-3-adamantan-1-yl-urea (AR9281) as a potent, selective, and orally available soluble epoxide hydrolase inhibitor with efficacy in rodent models of hypertension and dysglycemia.

1-(1-Acetyl-piperidin-4-yl)-3-adamantan-1-yl-urea 14a (AR9281), a potent and selective soluble epoxide hydrolase inhibitor, was recently tested in a phase 2a clinical setting for its effectiveness in reducing blood pressure and improving insulin resistance in pre-diabetic patients. In a mouse model of diet induced obesity, AR9281 attenuated the enhanced glucose excursion following an intraperitoneal glucose tolerance test. AR9281 also attenuated the increase in blood pressure in angiotensin-II-induced hypertension in rats. These effects were dose-dependent and well correlated with inhibition of the sEH activity in whole blood, consistent with a role of sEH in the observed pharmacology in rodents.

Soluble epoxide hydrolase in atherosclerosis.

Like many eicosanoids, epoxyeicosatrienoic acids (EETs) have multiple biological functions, including reduction of blood pressure, inflammation, and atherosclerosis in multiple species. Hydration of EETs by the soluble epoxide hydrolase (sEH) is the major route of their degradation to the less bioactive diols. Inhibition of the sEH stabilizes EETs, thus, enhancing the beneficial effects of EETs. Human data show an association of sEH (Ephx2) gene polymorphisms with increased risk of atherosclerosis and cardiovascular diseases. These data suggest a potential therapeutic effect of sEH inhibitors (sEHI) in the treatment of atherosclerosis. Indeed, two laboratories reported independently that using different sEHIs in apolipoprotein E-deficient mice significantly attenuated atherosclerosis development and aneurysm formation. The antiatherosclerotic effects of sEHI are correlated with elevation in EET levels and associated with reduction of low-density lipoprotein and elevation of high-density lipoprotein cholesterols, as well as attenuation of expression of proinflammatory genes and proteins. In addition, the antihypertensive effects and improvement of endothelial function also contribute to the mechanism of the antiatherosclerotic effects of sEHI. The broad spectrum of biological action of EETs and sEHIs with multiple biological beneficial actions provides a promising new class of therapeutics for atherosclerosis and other cardiovascular diseases.

Inhibition of soluble epoxide hydrolase attenuated atherosclerosis, abdominal aortic aneurysm formation, and dyslipidemia.

OBJECTIVE: Epoxyeicosatrienoic acids (EETs) have been shown to have antiinflammatory effects and therefore may play a role in preventing vascular inflammatory and atherosclerotic diseases. Soluble epoxide hydrolase (s-EH) converts EETs into less bioactive dihydroxyeicosatrienoic acids. Thus, inhibition of s-EH can prevent degradation of EETs and prolong their effects. The present study aimed to test the hypothesis that inhibition of s-EH has vascular protective effects. METHODS AND RESULTS: Six-month-old apolipoprotein E-deficient mice were chronically infused with angiotensin II (1.44 mg/kg/d) for 4 weeks to induce abdominal aortic aneurysm (AAA), accelerate atherosclerosis development and carotid artery ligation-induced vascular remodeling. The mice were treated with a novel s-EH inhibitor, AR9276 (1.5 g/L in drinking water) or vehicle for 4 weeks. The results demonstrated that AR9276 significantly reduced the rate of AAA formation and atherosclerotic lesion area, but had no effect on ligation-induced carotid artery remodeling. These effects were associated with a reduction of serum lipid, IL-6, murine IL-8-KC, and IL-1alpha, and downregulation of gene expressions of ICAM-1, VCAM-1, and IL-6 in the arterial wall. CONCLUSIONS: The present data demonstrate that treatment with an s-EH inhibitor attenuates AAA formation and atherosclerosis development. The attendant downregulation of inflammatory mediators and lipid lowering effects may both contribute to the observed vascular protective effects.

Posterior mediastinal neurilemmoma accompanied by intrapulmonary sequestration in the left lower lobe: A case report.

RATIONALE: The presence of a mediastinal neurilemmoma accompanied by intrapulmonary sequestration is a rare occurrence. The clinical symptoms of a neurilemmoma depend on the site of the tumor. Diagnosis of pulmonary sequestration mainly depends on the presence of aberrant feeding arteries. PATIENT CONCERNS: A 78-year-old woman was admitted to our hospital with a mediastinal space-occupying lesion of 50 years. Computed tomography and magnetic resonance imaging showed 2 roundish low-density shadows in the left posterior mediastinum. DIAGNOSIS: The pathological findings of the upper cystic mass support the diagnosis of neurilemmoma. A branch of aorta was found supplying blood to the lower mass; it was considered a pulmonary sequestration. INTERVENTIONS: Left-sided thoracotomy was planned to remove the chest space-occupying lesions. Two masses were completely removed. Severe adhesion between the left lower lobe and the diaphragm was successfully separated, the aberrant feeding vessel was properly managed, and the lower lobe was resected completely. OUTCOMES: The patient experienced remission of symptoms, had no significant postoperative complications, and was discharged from the hospital. LESSONS: Special attention should be paid to neurological involvement of the neurilemmoma and the fragile feeding arteries of the intrapulmonary sequestration. Early diagnosis and treatment are important in such cases.

MicroRNA-384 inhibits the progression of esophageal squamous cell carcinoma through blockade of the LIMK1/cofilin signaling pathway by binding to LIMK1.

INTRODUCTION: Esophageal squamous cell carcinoma (ESCC) represents an aggressive malignancy often accompanied with a poor prognosis. Owing to the poor mortality and morbidity rates associated with this malignancy, a deeper understanding of the finer molecular changes that occur in ESCC is required in order to identify novel potential targets for early detection and therapy. At present the mechanism by which ESCC functions on a molecular level is not fully understood. Hence, the aim of the present study was to ascertain as to whether microRNA-384 (miR-384) influences the progression of ESCC. MATERIAL AND METHODS: Bioinformatics analysis was initially conducted to identify ESCC-related differentially expressed genes and predict regulatory miRs. After the target relationship between miR-384 and LIMK1 had been verified, the expression of miR-384 and LIMK1 in the EC9706 cell line was altered in an attempt to investigate the regulatory roles of miR-384 in the expression of the LIMK1/cofilin signaling pathway-related genes, cell proliferation, invasion, cell cycle distribution and apoptosis, in addition to lymph node metastasis (LNM) and tumor growth in nude mice. RESULTS: Microarray-based gene expression profiling indicated that miR-384 affected the progression of ESCC through the LIMK1-mediated LIMK1/cofilin signaling pathway. Furthermore, miR-384 and Bax were observed to be poorly expressed, while LIMK1, cofilin and Bcl-2 were highly expressed in ESCC. The obtained evidences indicating that miR-384 targeted and negatively regulated LIMK1. Upregulation of miR-384 or LIMK1 inhibition was determined to block the LIMK1/cofilin signaling pathway, repress cell proliferation, invasion, cell cycle, LNM and tumor growth, while promote cell apoptosis in ESCC. CONCLUSION: Collectively, based on the key findings of the study, miR-384 could sequester LIMK1, which acts to suppress activation of the LIMK1/cofilin signaling pathway, thus ultimately inhibiting the development and progression of ESCC.

Asymptomatic left posterior mediastinal functional paraganglioma: A case report.

RATIONALE: Paraganglioma refers to a set of neuroendocrine tumors derived from the chromaffin cells of the adrenal diplomatic ganglion. Paragangliomas can be classified as functional or nonfunctional based on the ability to synthesize and release catecholamines. PATIENT CONCERNS: We report a 47-year-old man with a functional paraganglioma in the left posterior mediastinum and highlight the key elements of management of mediastinal paragangliomas. DIAGNOSES: A left posterior mediastinal mass was found by computed tomography (CT) scan and Chest-enhanced CT. Preoperative ultrasound-guided biopsy suggested the possibility of a paraganglioma. A diagnosis of paraganglioma was established by immunohistochemistry. INTERVENTIONS: The patient underwent single-stage resection of the lesion via left thoracotomy after preoperative oral α-adrenoceptor (phenoxybenzamine) therapy and intravenous fluid resuscitation for two weeks. OUTCOMES: The postoperative period was uneventful. The patient exhibited no abnormal blood pressure or recurrence during the 12-month follow-up period. LESSONS SUBSECTIONS AS PER STYLE: Pathological examination alone cannot determine whether it was a benign or malignant paraganglioma, which can be determined by pathological examination combined with distant metastasis. Long-term follow-up is required to assess the treatment effect.

The inhibitory effects of cisplatin-radiation combination treatment on malignant osteosarcoma MG-63 cells and BRCA1-p53 pathways are more efficient than single treatments.

The poor prognosis of patients with osteosarcoma remains a persistent problem, in particular for patients with unresectable tumors or metastasis. Therefore, combination of radiotherapy and chemotherapy has been considered for patients with metastasis or recurrence, patients unsuitable for surgery and patients refusing surgery. The present study aimed to investigate the effect of the combined treatment with cisplatin and radiation therapy on the biological characteristics of the osteosarcoma cell line MG-63 and the breast cancer 1 (BRCA1)-associated signaling pathways. Cell proliferation was determined using Cell Counting kit-8 assay, and cell apoptosis and cell cycle were assessed by flow cytometry. Cell migration was examined by Transwell assay. The mRNA and protein expression levels of candidate genes, including BRCA1 and p53, were determined by reverse transcription-quantitative PCR and western blotting, respectively. The results demonstrated that combined treatment with radiation and cisplatin significantly inhibited MG-63 cell proliferation compared with radiation or cisplatin treatment alone. Furthermore, radiation, cisplatin or the combined treatment with radiation and cisplatin increased the apoptosis rate of MG-63 cells, which resulted in G2 phase arrest, and significantly decreased the migratory capacity of MG-63 cells. In addition, the apoptosis rate of MG-63 cells following combined radiation and cisplatin treatment was higher compared with the cisplatin group, but lower compared with the radiation group. Furthermore, combined treatment with radiation and cisplatin decreased the mRNA and protein expression levels of BRCA1 and p53. Additionally, combined treatment with radiation and cisplatin had a more potent inhibitory effect on p53 expression than on BRCA1 expression. In addition, combination of radiation and cisplatin had a higher inhibitory effect on Bax protein level and a higher inductive effect on Bcl-2 protein level compared with treatments with radiation and cisplatin alone. The results demonstrated that combined treatment of radiation and cisplatin exhibited superior therapeutic effects on osteosarcoma MG-63 cells compared with radiation or cisplatin treatment alone, which may be mediated by the BRCA1-p53 signaling pathway.

Mechanisms of intimal hyperplasia learned from a murine carotid artery ligation model.

The murine carotid artery ligation (CAL) model has been widely used in the research of intimal hyperplasia, a major pathological process in vascular diseases, such as atherosclerosis and restenosis after angioplasty. Using a variety of gene knockout or transgenic mice and different pharmacological interventions, these studies have yielded significant new findings that contribute not only to unraveling the basic molecular mechanisms involved in the pathogenesis of intimal hyperplasia, but also to the identification of novel targets for intervention of these diseases. The current review outlines the findings derived from the murine CAL model, including studies run by the authors, covering the impacts of hyperlipidemia, pro-inflammatory factors, endothelial dysfunction, protease activity and growth mediators on neointimal hyperplasia.

Monocyte chemoattractant protein-1 or macrophage inflammatory protein-1alpha deficiency does not affect angiotensin II-induced intimal hyperplasia in carotid artery ligation model.

BACKGROUND: Angiotensin II (Ang II) promotes atherosclerotic vascular diseases, in which proinflammatory and proliferative effects play a major pathogenic role. Ang II up-regulates chemokines, such as monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory protein (MIP)-1alpha, which are important pro-inflammatory factors mediating infiltration of inflammatory cells into atherosclerotic lesion. The aim of the present study was to determine whether the presence of MCP-1 or MIP-1alpha is essential in Ang II-induced intimal hyperplasia in the carotid artery ligation model. METHODS: Six-month-old male C57BL/6-, MCP-1-, or MIP-1alpha-deficient mice underwent ligation of the common left carotid artery and were randomly assigned to receive either vehicle or Ang II (1.4 mg kg(-1) day(-1)) via a subcutaneously implanted osmotic infusion pump (model 2004, Alzet) for 4 weeks. RESULTS: Ang II not only increased MCP-1 and MIP-1alpha production but also enhanced neo-intimal formation, media thickness, and adventitia development in the ligated carotid arteries in C57BL/6 mice. However, MCP-1 or MIP-1alpha deficiency failed to affect intimal hyperplasia in vascular remodeling. CONCLUSION: These results indicate that MCP-1 or MIP-1alpha may not be essential in mediating the proliferative effects of Ang II, a major pathological changes in intimal hyperplasia in the carotid artery ligation model.

Endothelial NO synthase deficiency promotes smooth muscle progenitor cells in association with upregulation of stromal cell-derived factor-1alpha in a mouse model of carotid artery ligation.

BACKGROUND: Endothelial NO deficiency (endothelial NO synthase [eNOS]-knockout [KO]) enhanced smooth muscle cell (SMC)-rich neointimal lesion formation in a mouse model of carotid artery ligation (CAL). Recent evidence indicated that stromal cell-derived factor-1alpha (SDF-1alpha)-mediated recruitment of circulating SMC progenitor cells substantially contributed to the SMC-rich neointimal hyperplasia induced by vascular injury. The goal of this study was to investigate the effects of eNOS deficiency on the expression of SDF-1alpha and mobilization of circulating SMC progenitor cells in CAL model. METHODS AND RESULTS: Two- to 3-month-old C57BL/6J wild-type (WT) and eNOS-KO mice were evaluated 1, 2, or 4 weeks after CAL. CAL-induced expression of SDF-1alpha, as detected by immunohistochemical staining and further quantified by ELISA in the ligated carotid arteries, was moderate and transient with a peak at 1 week in WT mice. SDF-1alpha expression was significantly higher at 1 week and persisted through 2 weeks in eNOS-KO mice. CAL was associated with increased circulating stem cell antigen-1(+) (Sca-1(+))/c-Kit(-)/Lin- cells (interpreted as SMC progenitor cells), which peaked at 1 week in WT mice. This effect was also significantly greater and longer-lasting in eNOS-KO than WT mice. The number of circulating Sca-1(+)/c-Kit(-)/Lin- cells was positively correlated with the expression of SDF-1alpha but not vascular endothelial growth factor in the ligated carotid arteries. Furthermore, immunostaining showed abundant Sca-1-positive cells in the adventitia of the 1-week ligated carotid arteries from eNOS-KO mice but not in WT mice. We also determined that eNOS deficiency enhanced CAL-induced intimal cell proliferation in the ligated arteries as detected by proliferating cell nuclear antigen staining but did not induce cell apoptosis as detected by staining for active caspase-3. CONCLUSIONS: Our results indicate that eNOS deficiency exacerbates CAL-induced expression of SDF-1alpha and its receptor CXCR4. This is correlated with an increase in Sca-1(+) cells in peripheral blood and adventitia, which may contribute to vascular remodeling and SMC-rich neointimal lesion formation. This suggests that constitutive eNOS inhibits SDF-1alpha expression and provides an important vasculoprotective mechanism for intact endothelium to limit SMC proliferation and recruitment in response to vascular injury.

Clinicopathological significance of matrix metalloproteinase-7 protein expression in esophageal cancer: a meta-analysis.

BACKGROUND: The MMP-7 basement membrane and extracellular matrix may be essential for tumor invasion and metastasis, and the results presented herein showed a relationship between MMP-7 expression and esophageal cancer (EC). However, its clinicopathological value for EC patients remains inconsistent. To clarify their associations, a meta-analysis of the relevant published literature was conducted. MATERIALS AND METHODS: Databases including PubMed, Embase, Web of Science, Cochrane Library, CISCOM, CINAHL, and Google Scholar were electronically searched. Only those studies analyzing MMP-7 expression in EC patients with regard to series of different demographic variables and clinicopathological stages (TNM stage, differentiation and invasion grade, and lymph-node [LN] metastasis) were eligible for inclusion. Summary odds ratios (ORs) were pooled in accordance with the random-effect model. RESULTS: Fourteen clinical cohort studies (tumor samples =935) were incorporated into the current meta-analysis. Results revealed that increased MMP-7 expression in EC patients was positively correlated to TNM stage III-IV (OR 3.04, 95% confidence interval [CI] 1.43-6.46; P=0.004). Similar connections were also detected in the differentiation grade, invasion grade, and LN metastasis (all P<0.05). Country-stratified analysis yielded significant association of elevated MMP-7 expression with EC in the People's Republic of China (PRC) under both TNM III-IV versus I-II and differentiation low versus high comparisons (TNM stage, OR 2.01, 95% CI 1.55-2.59, P<0.001; differentiation grade, OR 1.32, 95% CI 1.11-1.57, P=0.002). With regard to invasion grade and LN metastasis, significant association was observed in all the experimental subgroups (all P-values [PRC and Japan] were lower than 0.05). CONCLUSION: These data showed an obvious connection between MMP-7 and TNM stages, differentiation grade, invasive grade, and LN metastasis of EC, indicating that overexpression of MMP-7 may be a suitable diagnostic biomarker for variation in EC clinicopathological features.

Correlation of CCNA1 promoter methylation with malignant tumors: a meta-analysis introduction.

Epigenetic silencing of tumor suppressor genes by promoter methylation plays vital roles in the process of carcinogenesis. The purpose of this meta-analysis was to determine whether the aberrant methylation of cyclin A1 (CCNA1) may be of great significance to human malignant tumors. By searching both English and Chinese language-based electronic databases carefully, we tabulated and analyzed parameters from each study. All human-associated case-control studies were included providing available data for CCNA1 methylation and reporting the adjusted odds ratios (ORs) and 95% confidence intervals (CI) conducted with the use of Version 12.0 STATA software. A total of 10 case-control studies (619 patients with cancers and 292 healthy controls) were included for the following statistical analysis. Pooled OR values from all articles revealed that the frequency of CCNA1 methylation in cancer tissues was significantly higher than those of normal tissues (P < 0.001). Further ethnicity indicated that the frequency of CCNA1 methylation was correlated with the development of malignant tumors among all those included experimental subgroups (all P < 0.05). These data from results indicated a significant connection of CCNA1 methylation with poor progression in human malignant tumors among both Caucasian and Asian populations.

Role of tissue transglutaminase in the pathogenesis of diabetic cardiomyopathy and the intervention effect of rutin.

The aim of this study was to investigate the role of tissue transglutaminase (tTG) in the pathogenesis of diabetic cardiomyopathy (DCM) and the intervention effect of rutin. DCM was induced in rats by the injection of streptozotocin (STZ; 25 mg/kg). After a preliminary examination, the rats were randomly divided into four groups: Control (n=8), STZ-induced DCM (n=8), STZ + positive drug (captopril; n=6) and STZ + rutin (n=8) groups. The DCM model was evaluated using blood sugar values, serum enzyme levels, hematoxylin and eosin staining and Masson's staining, ex vivo. The protein and mRNA expression of tTG was assessed with immunohistochemistry, western blotting and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The rat model of DCM was successfully established by STZ administration, and the expression levels of tTG were significantly increased in the DCM model. Following the injection of captopril or rutin, the blood sugar values, collagen content and expression levels of tTG were gradually reduced and serum enzyme levels were increased, as compared with those in the STZ-induced DCM group. In conclusion, tTG plays an important role in STZ-induced DCM. In addition, rutin may inhibit the expression of tTG and regulate myocardial injury in STZ-induced DCM.

Daily short-period gravitation can prevent functional and structural changes in arteries of simulated microgravity rats.

This study was designed to clarify whether simulated microgravity-induced differential adaptational changes in cerebral and hindlimb arteries could be prevented by daily short-period restoration of the normal distribution of transmural pressure across arterial vasculature by either dorsoventral or footward gravitational loading. Tail suspension (Sus) for 28 days was used to simulate cardiovascular deconditioning due to microgravity. Daily standing (STD) for 1, 2, or 4 h, or +45 degrees head-up tilt (HUT) for 2 or 4 h was used to provide short-period dorsoventral or footward gravitational loading as countermeasure. Functional studies showed that Sus alone induced an enhancement and depression in vasoconstrictor responsiveness of basilar and femoral arterial rings, respectively, as previously reported. These differential functional alterations can be prevented by either of the two kinds of daily gravitational loading treatments. Surprisingly, daily STD for as short as 1 h was sufficient to prevent the differential functional changes that might occur due to Sus alone. In morphological studies, the effectiveness of daily 4-h HUT or 1-h STD in preventing the differential remodeling changes in the structure of basilar and anterior tibial arteries induced by Sus alone was examined by histomorphometry. The results showed that both the hypertrophic and atrophic changes that might occur, respectively, in cerebral and hindlimb arteries due to Sus alone were prevented not only by daily HUT for 4 h but also by daily STD even for 1 h. These data indicate that daily gravitational loading by STD for as short as 1 h is sufficient to prevent differential adaptational changes in function and structure of vessels in different anatomic regions induced by a medium-term simulated microgravity.

Effectiveness of intermittent -Gx gravitation in preventing deconditioning due to simulated microgravity.

This study was designed to compare the effectiveness of daily short-duration -Gx gravity exposure in preventing adverse changes in skeletal and cardiac muscles and bone due to simulated microgravity. Tail suspension for 28 days was used to simulate microgravity-induced deconditioning effects. Daily standing (STD) at 1 G for 1, 2, or 4 h/day or centrifugation (CEN) at 1.5 or 2.6 G for 1 h/day was used to provide -Gx gravitation as a countermeasure. The results indicate that the minimum gravity exposure requirements vary greatly in different systems. Cardiac muscle is most responsive to such treatment: 1 h/day of -Gx gravitation by STD was sufficient to prevent adverse changes in myocardial contractility; bone is most resistant: 4 h/day of -Gx gravitation only partially alleviated the adverse changes in physical and mechanical properties of the femur. The responsiveness of skeletal muscle is moderate: 4 h/day of -Gx gravitation prevented mass reduction and histomorphometric changes in the soleus muscle during a 28-day simulation period. Increasing gravitational intensity to 2.6 G showed less benefit or no additional benefit in preventing adverse changes in muscle and bone. The present work suggests that system specificity in responsiveness to intermittent gravity exposure should be considered one of the prerequisites in proposing intermittent artificial gravity as a potential countermeasure.

[Preparation and identification of polyclonal antiserum against angiotensinogen].

For studying the expression and distribution of angiotensinogen (AGT), the C-teminus of rat AGT gene was expressed in E.coli. Rabbits were immunized with expressed AGT protein and sera from different rabbits were raised. ELISA showed a high titre (1:25600) of the antiserum. With the antiserum, Western blotting recognized not only the prokaryotic expressed AGT, but also the endogenous AGT protein in liver tissue of both rats and humans. Using this antiserum, immunohistochemistry showed the expression of AGT protein in islet cells of human pancreas as well as in epithelium of human bile duct. These results suggest that the prokaryotic expressed AGT protein is an effective immunogen for the preparation of anti-AGT antiserum. Our present work provides an important tool for study of the pathophysiological role of AGT as well as local renin-angiotensin system.

[The inhibiting effect of niflumic acid on airway hyperresponsiveness in asthmatic mice].

OBJECTIVE: To evaluate the inhibiting effect of niflumic acid (NFA), an inhibitor of calcium-activated chloride channel (ClCa) on airway epithelium, on the airway hyperresponsiveness in asthmatic mice. METHODS: BALB/c mice were randomly divided into an asthma group (A group), a NFA prevention asthmatic group (B group) and a sham-challenged group (C group). The airway pressure time index (APTI) and the content of ET-1 and NO in bronchoalveolar lavage fluid (BALF) in all groups were measured. With the isolated tracheal rings with integral epithelium or epithelium removed from the asthma group (A(1) group and A(2) group) and the sham-challenged group (C(1) group and C(2) group), the contractile responsiveness of various rings to methacholine (mACh) was examined, and its change was observed when the rings were exposed to NFA beforehand. RESULTS: Compared with A group (1.62 +/- 0.14), the APTI in B group (1.21 +/- 0.07) was reduced remarkably (P < 0.01), and the contents of ET-1 [(103 +/- 9) ng/L] and NO [(48.5 +/- 3.2) micromol/L] in BALF of A group were significantly higher than those in B group, [(53 +/- 5) ng/L, (23.7 +/- 2.5) micromol/L (P < 0.01), respectively]. The ratios of maximum contractility in A(1), A(2), C(1) and C(2) groups were (3.79 +/- 0.44), (2.15 +/- 0.21), (1.26 +/- 0.14) and (2.06 +/- 0.18), respectively. The contractility of A(1) group was highest among all groups (all P < 0.01), but could be effectively decreased by NFA. CONCLUSIONS: By inhibiting the special ClCa on the airway epithelium, NFA can inhibit the production of ET-1 and NO by epithelium and thus exert preventive effect on airway hyperresponsiveness in asthma.

[A study on gene expression of angiotensin receptors in arteries from tail-suspended rats].

Objective. To investigate whether simulated microgravity [correction of microgravtiy] can result in alterations of mRNA expression of angiotensin receptors in rat arteries. Method. Rats were divided into simulated microgravity group and synchronous control group. Simulated microgravity rats were subjected to tail-suspension for 4-wk to simulate the effect of weightlessness. Result. Results from RT-PCR demonstrated that mRNAs of angiotensin II receptors, AT1a, AT1b, and AT2 were expressed in carotid arteries, abdominal aorta and femoral arteries, whereas only mRNAs of AT1a and AT1b were expressed in basilar arteries. There were no significant differences between the simulated-microgravity and control rats in the expression of mRNAs of AT1a, AT1b, and AT2 in these arteries. Conclusion. Angiotensin II receptors may play no regulatory role in the occurrence of the differentiated vascular adaptation during simulated microgravity.