OBJECTIVES: To study the role of adrenomedullin (ADM) in hyperoxia-induced lung injury by examining the effect of ADM on the expression of calcitonin receptor-like receptor (CRLR), receptor activity-modifying protein 2 (RAMP2), extracellular signal-regulated kinase (ERK), and protein kinase B (PKB) in human pulmonary microvascular endothelial cells (HPMECs) under different experimental conditions. METHODS: HPMECs were randomly divided into an air group and a hyperoxia group ( RESULTS: Compared with the air group, the hyperoxia group had significant increases in the mRNA and protein expression levels of ADM, CRLR, RAMP2, ERK1/2, and PKB ( CONCLUSIONS ERK1/2 and PKB may be the downstream targets of the ADM signaling pathway. ADM mediates the ERK/PKB signaling pathway by regulating CRLR/RAMP2 and participates in the protection of hyperoxia-induced lung injury.
Adrenomedullin/genetics* ; Endothelial Cells ; Humans ; Hyperoxia/complications* ; Lung Injury ; Receptor Activity-Modifying Proteins

This experiment on rats was aimed to investigate the expression of intermedin (IMD) in hypertrophic cardiac myoctye of renal vascular hypertension induced by incomplete ligation of the left renal artery, and so to detect and compare the changes of the expression after administration of Valsartan, Amlodipine and Enalapril respectively. The criterion for standard modeling was systolic pressure > or = 140 mmHg. At 4 weeks after successful modeling, 60 SD male rats were randomly divided into 5 groups, namely the hypertrophy group, the 3 drug-treatment groups, and the sham-operation group as control. Blood pressure, left ventricular mass index (LVMI), and the left ventricular mean transverse diameter of myocardial cell (LVTDM) were investigated at the 10th week after model establishment. Gene expression of IMD mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR), and the optical density of the band was measured by use of the Gel Documentation System. The ratio of IMD mRNA to beta-actin mRNA was considered the relative amount of IMD. When compared with control, the blood pressure increased significantly in the hypertrophy group. There was no statistically significant difference between the treatment groups. No significant difference in heart rate was noted at 4 weeks after operation in all groups. LVMI and LVTDM levels were significantly higher in the hypertrophy group than in the other groups; LVMI and LVTDM levels showed no significant difference among the treatment groups but they were obviously higher than those of the Sham-operation group. The gene expression of IMD mRNA in the hypertrophy group was upregulated in the myocardium, when compared with that in the other groups. Meanwhile, although IMD mRNA in the treament groups was higher than that in the Sham-operation group, no statistically significant difference of myocardial IMD mRNA was found between the treament groups. These results suggested that, in this experiment, intracardiac IMD mRNA was upregulated and could participate in the regulation of cardiac remodeling in renal vascular hypertension-induced cardiac hypertrophy. This upregulation could improve the pathologic and physiologic process of cardiac hypertrophy, and could associate with the pressure loading or myocardia hypertrophy. However, the change did not display any difference that could be attributed to the variety of hypotensive drugs.
Adrenomedullin ; genetics ; metabolism ; Amlodipine ; therapeutic use ; Animals ; Antihypertensive Agents ; therapeutic use ; Cardiomegaly ; etiology ; metabolism ; Enalapril ; therapeutic use ; Hypertension, Renovascular ; complications ; drug therapy ; metabolism ; Male ; Myocardium ; metabolism ; Neuropeptides ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Tetrazoles ; therapeutic use ; Valine ; analogs & derivatives ; therapeutic use ; Valsartan

AIMTo study the effect and significances of two-week hypoxia on the expression of intermedin/adrenomedullin2 (IMD/ADM2) in plasma and the tissues of heart and lung in rats.

METHODSTwenty male SD rats were randomly divided into normal control group and hypoxia group. The concentrations of IMD/ADM2 and adrenomedullin (ADM) in plasma, right ventricle and lung tissue were measured by radioimmunoassay. RT-PCR was used to detect the mRNA levels of IMD/ADM2 and ADM in right ventricle and lung tissue.

RESULTS(1) The mean pulmonary arterial pressure (mPAP) and the weight ratio of right ventricle (RV) to left ventricle plus septum (LV + S) of hypoxia group were significantly higher than those of normal control group (P < 0.01). (2) The concentrations of IMD/ADM2 and ADM in plasma were significantly higher in hypoxia group, compared with normal control group (P < 0.01). (3) The concentration of ADM in right ventricle and lung tissue in hypoxia group was significantly higher than that in normal control group (P < 0.01), while there was no significant difference in IMD/ADM2 between the two groups. (4) The mRNA levels of IMD/ADM2 and ADM in right ventricle and lung tissues were significantly up-regulated in hypoxia group (P < 0.05).

CONCLUSIONThe expressions of IMD/ADM2 peptides and gene in plasma, right ventricular and pulmonary tissues are different in the early-middle pathological proceeding of pulmonary hypertension induced by two-week hypoxia in rats.

Adrenomedullin ; blood ; genetics ; metabolism ; Animals ; Hypertension, Pulmonary ; etiology ; metabolism ; Hypoxia ; complications ; metabolism ; Lung ; metabolism ; Male ; Myocardium ; metabolism ; Neuropeptides ; blood ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo establish a nude mouse model of nasopharyngeal carcinoma (NPC) lymph node metastasis and screen the signature genes associated with the metastasis.

METHODSThe NPC 5-8F-EGFP cells were inoculated into nude mice, from which a 5-8F-LN cell line with lymph node metastasis potential was obtained. The lymphatic metastasis-related signature genes of breast cancer and head and neck squamous cell carcinoma were screened by data mining method.

RESULTSThe NPC cell lines 5-8F and 6-10B showed 307 differentially expressed genes by microarray analysis, from which 20 overlapping genes were identified, and 3 overexpressed genes were found with probable metastasis potential, namely the ADM, IRF1, and CAV1 genes. Quantitative RT-PCR validated the data mining results in the 5-8F-EGFP, 6-10B-EGFP, NP69, and 5-8F-LN cell lines. The 3 NPC cell lines 5-8F-EGFP, 6-10B-EGFP and 5-8F-LN showed significantly higher expressions of IRF1 than NP69 cells (P=0.008, 0.022, and 0.006, respectively. The expression level of CAV1 in 5-8F-EGFP cells was significantly higher than that in 6-10B-EGFP cells (P=0.014), but ADM expression showed no significant difference between the 4 cell lines.

CONCLUSIONSIRF1 may play an important role in the progression of NPC. The overexpression of CAV1 in 5-8F-EGFP cells can be associated with the high metastatic potential of the cells.

Adrenomedullin ; genetics ; Animals ; Caveolin 1 ; genetics ; Cell Line, Tumor ; Disease Models, Animal ; Gene Expression Profiling ; Humans ; Interferon Regulatory Factor-1 ; genetics ; Lymphatic Metastasis ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Nasopharyngeal Neoplasms ; genetics ; pathology ; Neoplasm Transplantation ; Reverse Transcriptase Polymerase Chain Reaction ; Transplantation, Heterologous

OBJECTIVETo detect the correlation between the microsatellite DNA polymorphism of adrenomedullin(ADM) gene (repeated sequences of CA) and the atherosclerotic cerebral infarction (ACI).

METHODSWith PCR, ADM genotype was monitored from 189 normotensive subjects and 283 cerebral infarction patients. By using radioimmunoassay, their plasma ADM concentration was measured, so as the biochemical index.

RESULTSThe genotype distribution of ADM between the health control and ACI groups was significantly different, chi square was 28.732, P < 0.05. As one of the four alleles, including 11, 13, 14 and 19 alleles, the frequency of 19 allele in ACI groups was much higher than that in the health control group, chi square was 26.929, P < 0.05. However, there was no significant difference in plasma ADM concentration among the different genotypes of the ACI patients.

CONCLUSIONMicrosatellite DNA polymorphism of ADM gene may be associated with the genetic predisposition to ACI.

Adrenomedullin ; genetics ; Adult ; Aged ; Alleles ; Case-Control Studies ; Cerebral Infarction ; complications ; genetics ; Female ; Gene Frequency ; Genotype ; Humans ; Intracranial Arteriosclerosis ; complications ; genetics ; Male ; Microsatellite Repeats ; genetics ; Middle Aged ; Polymorphism, Genetic

OBJECTIVEThe mechanism of high pulmonary blood flow-induced pulmonary hypertension remains unclear. The aim of this study was to explore the effect of proadrenomedullin N-terminal 20-peptide (PAMP) on pulmonary hypertension, through examining the alterations of pulmonary PAMP expression and plasma PAMP concentration in rats with pulmonary hypertension induced by high pulmonary blood flow.

METHODSSixteen male Sprague-Dawley rats were randomly divided into control (n=8) and shunt groups (n=8). Aortocaval shunting was produced in the shunt group. After 11 weeks of shunting, systolic pulmonary artery pressure (sPAP), diastolic pulmonary artery pressure (dPAP) and mean pulmonary artery pressure (mPAP) were evaluated by using a right cardiac catheterization procedure. The ultrastructural changes in intra-acinar pulmonary arteries were observed. The concentration of plasma PAMP was measured by radioimmunoassay. The expression of PAMP in pulmonary arteries was detected by immunohistochemical assay.

RESULTSsPAP, dPAP and mPAP were significantly increased in shunt rats compared with controls (P < 0.01). Ultrastructural changes, such as hyperplasia and swelling of endothelial cells, irregularity of internal elastic laminar, and hypertrophy and increased number of synthetic phenotype of smooth muscle cells, were found in intra-acinar pulmonary muscularized arteries in the shunt group. Plasma PAMP concentration (616 +/- 195 pg /mL vs 427 +/- 90 pg /mL) and PAMP expression in endothelial cells (0.62 +/- 0.09 vs 0.38 +/- 0.12) and in smooth muscle cells (0.24 +/- 0.07 vs 0.14 +/- 0.05) of pulmonary arteries increased significantly in the shut group compared with controls.

CONCLUSIONSThe up-regulation of pulmonary and plasm PAMP expression might be involved in the development of high pulmonary blood flow-induced pulmonary hypertension.

Adrenomedullin ; blood ; genetics ; Animals ; Hypertension, Pulmonary ; blood ; etiology ; pathology ; Male ; Pulmonary Artery ; ultrastructure ; Pulmonary Circulation ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the differential expression of adrenomedullin (ADM) in the placentas of women with normal and preeclamptic pregnancies, and explore the importance of ADM and its signal pathway in the development of preeclampsia.

METHODSTen pregnant women complicated with preeclampsia during the late term(>or=35 wk) were selected for this study along with 7 normal control pregnant women (>or=39 wk). The total RNA was extracted and sections of fresh placental tissues were prepared, and ADM expressions at mRNA and protein levels in women with normal and preeclamptic pregnancies were determined by Northern blotting and immunohistochemistry, respectively.

RESULT AND CONCLUSIONAt both mRNA and protein levels, the expression of ADM in the placentas of preeclamptic women was significantly reduced obviously as compared with that of the normal control (P<0.05), suggesting that ADM expression reduction in preeclamptic placenta might be associated with the development of preeclampsia.

Adrenomedullin ; biosynthesis ; genetics ; Adult ; Blotting, Northern ; Female ; Gene Expression Profiling ; Humans ; Immunohistochemistry ; Placenta ; metabolism ; Pre-Eclampsia ; genetics ; metabolism ; Pregnancy ; RNA, Messenger ; biosynthesis ; genetics

OBJECTIVETo investigate the expression of human adrenomedullin (ADM) and its receptor-receptor activity modifying protein 2/calcitonin receptor-like receptor (RAMP2/CRLR) mRNA in the tissues of normal adrenal medulla and pheochromocytoma.

METHODSTotal RNA was extracted from normal adrenal medulla and pheochromocytomas. The expression of ADM and RAMP2/CRLR mRNA were studied by reverse transcription-polymerase chain reaction. The ratios of ADM/GAPDH, RAMP2/ GAPDH, CRLR/GAPDH were used to evaluate the expression levels of ADM, RAMP2 and CRLR mRNA.

RESULTSExpressions of ADM and its receptor- RAMP2/CRLR mRNA were detected in normal adrenal medulla and pheochromocytoma tissues. ADM/GAPDH were 0.48+/-0.09 and 0.75+/-0.24, RAMP2/ GAPDH 0.79+/-0.12 and 1.29+/-0.30, CRLR/GAPDH 0.40+/-0.08 and 0.87+/-0.22 in normal adrenal medulla and pheochromocytomas, respectively (P < 0.05).

CONCLUSIONADM exerts a possible autocrine or paracrine effect in the adrenal. ADM may be involved in the pathogenesis of pheochromocytoma.

Adrenal Gland Neoplasms ; metabolism ; Adrenal Medulla ; metabolism ; Adrenomedullin ; Adult ; Calcitonin Gene-Related Peptide ; biosynthesis ; genetics ; Female ; Humans ; Intracellular Signaling Peptides and Proteins ; genetics ; Male ; Membrane Proteins ; biosynthesis ; genetics ; Middle Aged ; Peptides ; genetics ; metabolism ; Pheochromocytoma ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Receptor Activity-Modifying Protein 2 ; Receptor Activity-Modifying Proteins ; Receptors, Adrenomedullin ; Receptors, Calcitonin ; biosynthesis ; genetics ; Receptors, Peptide ; metabolism

OBJECTIVEReceptor activity-modifying proteins (RAMPs) determine the ligand specificity of the calcitonin receptor-like receptor (CRLR); co-expression of RAMP1 and CRLR results in a calcitonin gene related peptide (CGRP) receptor, whereas the association of RAMP2 or RAMP3 with CRLR gives an adrenomedullin(ADM) receptor. As CGRP and ADM may play a beneficial role in heart failure, this study aimed at the question whether RAMPs mRNAs are changed in heart failure.

METHODSSemi-quantitative reverse transcription-PCR (RT-PCR) was used to detect and quantify the mRNAs of RAMP1 and RAMP3 in the atria of heart failing patients.

RESULTSIt was found that the expressions of RAMP1, RAMP2 and RAMP3 mRNAs increased with the worsening of heart function, but the expressions of RAMP1 and RAMP2 mRNA decreased at level IV of heart failure.

CONCLUSIONThe above results demonstrated in the atria of heart failure patients an up-regulation of CGRP receptor by an increase of RAMP1 in association with CRLR and an up-regulation of ADM receptor by an increase of RAMP2 expression in association with CRLR, thus suggesting that CGRP and ADM receptors be playing a functional role in compensating the chronic heart failure in human.

Adult ; Calcitonin Receptor-Like Protein ; Female ; Heart Atria ; metabolism ; Heart Failure ; genetics ; physiopathology ; Humans ; Intracellular Signaling Peptides and Proteins ; genetics ; physiology ; Male ; Membrane Proteins ; genetics ; physiology ; Receptor Activity-Modifying Protein 1 ; Receptor Activity-Modifying Protein 2 ; Receptor Activity-Modifying Protein 3 ; Receptor Activity-Modifying Proteins ; Receptors, Adrenomedullin ; Receptors, Calcitonin ; genetics ; physiology ; Receptors, Calcitonin Gene-Related Peptide ; genetics ; physiology ; Receptors, Peptide ; genetics ; physiology ; Reverse Transcriptase Polymerase Chain Reaction

In this study, reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the changes in mRNAs levels of preproadrenomedullin (ppADM) gene encoding adrenomedullin (ADM) and the essential receptor components of ADM, calcitonin receptor-like receptor (CRLR), and the receptor activity modifying protein 2 and 3 (RAMP2 and RAMP3) in the medulla oblongata, hypothalamus, midbrain, pituitary gland and adrenal gland of the stress-induced hypertensive rats. It was shown that chronic foot-shock and noise stress for 15 consecutive days induced a significant increase in systolic blood pressure (SBP) and unique changes in ppADM and its receptor components mRNAs in all areas studied. As compared with the control group, the level of ppADM mRNA, normalized against a glyceraldehydes-3-phosphate dehydrogenase (GAPDH) control, was up-regulated in the hypothalamus-pituitary-adrenal (HPA) axis, but down-regulated in the medulla oblongata and midbrain (P<0.01 and P<0.05, respectively). The relative amount of CRLR mRNA was higher in the hypothalamus than that in other areas. The level of CRLR mRNA expression was significantly increased in the medulla oblongata of the stress group (P<0.01), but decreased in the midbrain (P<0.01) as well as hypothalamus(P<0.05), as compared with that of the control group. Chronic stress for 15 consecutive days produced an increase in the level of RAMP2 mRNA expression in the medulla oblongata (P<0.01) and a decrease in the adrenal gland (P<0.01), as compared with the control. No significant stress-related changes in RAMP2 mRNA were observed in the midbrain, hypothalamus and pituitary gland. The amount of RAMP3 mRNA was relatively higher in the midbrain and hypothalamus than that in the medulla oblongata, adrenal gland and adrenal gland. Stress-induced hypertensive rats exhibited an increased RAMP3 mRNA expression in the hypothalamus and pituitary gland (P<0.01 and P<0.05, respectively) and a decrease in the adrenal gland and midbrain (P<0.05). No significant stress-related change in RAMP3 mRAN was observed in the medulla oblongata. Taken together, our results indicate that the significant changes in ppADM and its receptor components mRNAs expression in the HPA axis and autonomic centers may be related to the development of the stress-induced hypertension. Nevertheless, the pathophysiological significance of brain-derived ADM and its receptors in stress and blood pressure regulation and their roles in stress-induced hypertension still await further investigation.
Adrenomedullin ; Animals ; Brain Stem ; metabolism ; Hypertension ; etiology ; metabolism ; Hypothalamo-Hypophyseal System ; metabolism ; Male ; Peptides ; genetics ; metabolism ; Pituitary-Adrenal System ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Sprague-Dawley ; Receptors, Adrenomedullin ; Receptors, Peptide ; biosynthesis ; genetics ; Stress, Physiological