新的小分子活性肽intermedin/adrenomedullin-2

Interm ed in(IMD)/adrenom edu llin-2(ADM2)是最近克隆出来的降钙素基因相关肽(CGRP)超家族成员,其结构类似于CGRP、肾上腺髓质素,通过降钙素受体样受体/受体活性修饰蛋白起作用。IMD/ADM2是一种内源性心脏-肾脏保护因子,作为循环激素和旁/自分泌因子在多种组织中发挥广泛生物学功能,具有降低血压、扩张冠脉、抗心脏缺血/再灌注损伤、调节水和电解质平衡、调节垂体激素分泌等生物学效应。

THE LOCALIZATION OF ADRENOMEDULLIN IN RAT KIDNEY TISSUE AND ITS INHIBITORY EFFECT ON THE GROWTH OF CULTURED RAT MESANGIAL CELLS

OBJECTIVE: To observe the localization of adrenomedullin (AM) in rat kidney tissue and its inhibitory effect on the growth of cultured rat mesangial cells (MsC). METHODS: A monoclonal antibody against AM developed by our laboratory was used to detect the localization of AM protein in rat kidney tissue by avidin-biotin complex immunohistochemistry. The expressions of AM and its receptor CRLR mRNA on cultured glomerular epithelial cells (GEC) and MsC were investigated by Northern blot assay, and the possible effect of AM secreted by GEC on MsC proliferation was observed using [3H]thymidine incorporation as an index. RESULTS: A specific monoclonal antibody against AM was succesfully developed. AM was immunohistochemically localized mainly in glomeruli (GEC and endothelial cells), some cortical proximal tubules, medullary collecting duct cells, interstitial cells, vascular smooth muscle cells and endothelial cells. Northern blot assay showed that AM mRNA was expressed only on cultured GEC, but not on MsC, however, AM receptor CRLR mRNA was only expressed on MsC. GEC conditioned medium containing AM can inhibit MsC growth and AM receptor blocker CGRP8-37 may partially decreased this inhibitory effect. CONCLUSION: AM produced by GEC inhibits the proliferation of MsC, which suggests that AM as an important regulator is involved in glomerular normal physiological functions and pathologic processes.

Effect of adrenomedullin on neuron apoptosis, infarction volume and expression of Egr-1 mRNA after focal ischemia-reperfusion in rats

Objective To observe the influence of adrenomedullin （ADM） on neuron apoptosis, infarction volume of brain, and the expression of early growth response 1 （Egr-1） mRNA in ischemia-reperfusion rats. Methods The arteria cerebri media was tied for 2 h to construct the ischemia model. Infarction volume was detected by triphenltetrazolium chloride （T＇I＇C） staining, neuronal apoptosis and necrosis was detected with terminal deoxynucleotidyl transferase nick labeling （TUNEL） method, and the Egr-1 mRNA expression was examined by in situ hybridization （ISH）. Results Infarction volume after ischemia-reperfusion is （269 ± 20） mm^3. Infarction volume after injection of ADM through different ways are femoral vein （239 ± 17） mm^3 （decreased by 11.2%）, arteria carotis （214 ± 14） mm^3 （by 20.4%） and lateral cerebral ventricle （209 ± 13） mm^3 （by 22.3%）, respectively. The results indicate that injecting ADM through arteria carotis and lateral cerebral ventricle is much more effective than it through femoral vein （P 〈 0.05）. The TUNEL-positive cells in cerebral cortex or hippocampus are few in the sham operation group, but much more in the ischemia-reperfusion group. After being supplied with ADM, especially through arteria carotis interna or lateral cerebral ventricle way, the TUNEL-positive cells decreased obviously. Expression of Egr- 1 mRNA was low in the cerebral cortex of the sham operation group rats, enhanced in the ischemia and reperfusion group rats, and enhanced markedly after treatment with ADM, especially through arteria carotis interna or lateral cerebral ventricle way （P 〈 0.01）. Conclusion Injection of ADM through different ways could alleviate neural dysfunction, decrease neuron apoptosis and brain infarction volume, and increase the expression of Egr- 1 mRNA.

Expression of human adrenomedullin gene in gastric adenocarcinoma and construction and identification of adrenomedullin overexpression vector and adrenomedullin-shRNA vector

Background:To explore the expression of adrenomedullin in gastric adenocarcinoma tissues,and to construct a eukaryotic expression vector that effectively overexpresses adrenomedullin gene and a short hairpin RNA eukaryotic expression vector that effectively inhibits adrenomedullin gene.This study lays the foundation for exploring the impact of adrenomedullin on solid tumors.Methods:A total of 60 samples of gastric adenocarcinoma tissues and adjacent tissues were collected.Immunohistochemical staining was used to verify the expression of adrenomedullin in gastric adenocarcinoma and the adjacent tissues.According to the adrenomedullin gene sequence in the National Center for Biotechnology Information and the design principle of the small interfering RNA target sequence,design and construct three specific short hairpin RNA expression vectors targeting the adrenomedullin gene mRNA and one homology using the lentiviral vector KLPO.1.The negative control vector,RT-PCR and Western blotting methods were used to detect the expression of the adrenomedullin gene,and the expression vector with the best inhibitory effect was selected.The eukaryotic expression vector pcDNA3 was used to construct an overexpression vector containing the full length of the adrenomedullin cDNA.RT-PCR and Western blotting methods were used to detect the expression of the adrenomedullin gene.Results:The PLKO.1-adrenomedullin with the best inhibitory effect and the human adrenomedullin gene overexpression vector pcDNA-adrenomedullin were successfully constructed and screened.Conclusion:Adrenomedullin is highly expressed in gastric cancer,and effectively inhibiting the expression of adrenomedullin in gastric cancer may have certain value in the treatment of gastric cancer.

Adrenomedullin: an important participant in neurological diseases

Adrenomedullin,a peptide with multiple physiological functions in nervous system injury and disease,has aroused the interest of researchers.This review summarizes the role of adrenomedullin in neuropathological disorders,including pathological pain,brain injury and nerve regeneration,and their treatment.As a newly characterized pronociceptive mediator,adrenomedullin has been shown to act as an upstream factor in the transmission of noxious information for various types of pathological pain including acute and chronic inflammatory pain,cancer pain,neuropathic pain induced by spinal nerve injury and diabetic neuropathy.Initiation of glia-neuron signaling networks in the peripheral and central nervous system by adrenomedullin is involved in the formation and maintenance of morphine tolerance.Adrenomedullin has been shown to exert a facilitated or neuroprotective effect against brain injury including hemorrhagic or ischemic stroke and traumatic brain injury.Additionally,adrenomedullin can serve as a regulator to promote nerve regeneration in pathological conditions.Therefore,adrenomedullin is an important participant in nervous system diseases.

Role of Adrenomedullin in Congenital Heart Disease Associated with Pulmonary Hypertension

The changes of adrenomedullin (ADM), endothelin-1 (ET-1) and nitric oxide (NO) levels before and after operation in congenital heart disease (CHD) associated with pulmonary hypertension (PH) were observed in order to investigate their role in CHD with PH and their clinical significance. The CHD patients were divided into 3 groups according to pulmonary artery systolic pressure (PASP): Non-PH group: PASP≤30 mmHg ( n =11); mild-PH group: PASP 31-49 mmHg ( n =10); moderate or severe-PH group: PASP≥50 mmHg ( n =12). The control group consisted of 15 health children. Plasma ADM, ET-1 and NO levels were determined by radioimmunoassay and colorimetry methods. The correlation between ADM and ET-1, NO, PASP was analyzed. The changes in plasma ADM, ET-1 and plasma NO on the 7th day after operation among the groups were compared. The results showed that plasma ADM levels in non-PH group were significantly higher than that in control group ( P <0.05), but there was no significant difference in ET-1 and NO levels between the two groups ( P >0.05). ADM and ET-1 levels in mild-PH group were significantly elevated as compared with those in non-PH group (both P <0.05), but NO levels were decreased ( P <0.05). ADM and ET-1 levels in moderate or severe-PH groups were increased as compared with those in mild-PH group (both P <0.01), but NO level significantly declined ( P <0.05). On the 7th day after operation, plasma ADM and ET-1 levels in PH group were significantly decreased ( P <0.05, P <0.01) as compared with those before operation, but there was no significant difference in NO levels ( P >0.05). But NO levels in non-PH group were significantly increased ( P <0.05). Plasma ADM levels in CHD were positively correlated with PASP and ET-1 ( r =0.77, P <0.01; r =0.82, P <0.01), negatively correlated with NO ( r =-0.56, P <0.05). It was concluded that during the progression of PH in the cases of CHD, plasma ADM, ET-1 and NO might play an important role in the development of PH. The increased ADM may represent a compensatory mechanism. It can interact with NO and ET-1 to regulate pulmonary circulation in the pathophysiology of PH with CHD. ADM may be involved in the defence mechanism against further increase of pulmonary arterial pressure. ADM could be used as a reliable indicator of the severity of CHD associated PH.

Local regulator adrenomedullin contributes to the circulatory disturbance in cirrhotic rats

AIM： To investigate whether adrenomedullin, a potent vasodilator peptide, plays a role in the circulatory disturbance in cirrhosis. METHODS： Cirrhosis was induced in rats by weekly gavage of carbon tetrachloride. Hemodynamic studies were performed in vivo using radioactive microspheres and in vitro using isolated aortic rings. The adrenomedullin concentrations were measured by radioimmunoassay. RESULTS： Acute administration of adrenomedullin to the control rats reduced the systemic arterial pressure along with an increase of serum levels of the stable metabolite of nitric oxide （NOx）, in a dose-dependent manner. Chronic infusion of adrenomedullin reduced the vascular resistance and increased the blood flow in the systemic and splanchnic circulation. Intravenous administration of anti-adrenomedullin antibody did not affect any hemodynamic parameters in the cirrhotic rats, whereas this antibody ameliorated the blunted contractile response to phenylephrine, o-adrenergic receptor agonist, in the aortic rings of the cirrhotic rats. The adrenomedullin concentrations in the aorta were higher in the cirrhotic rats than in the controls, and correlated with the mean arterial pressure in the cirrhotic rats. Moreover, adrenomedullin blunted the contractile response to phenylephrine in both of the control aorta and cirrhotic aorta, but not in the presence of NG-nitro L-arginine methyl ester, an NO synthase inhibitor. CONCLUSION： Adrenomedullin overproduced in the vascular wall may contribute to the circulatory disturbance in cirrhosis as a local regulator of the vascular tonus rather than a circulating hormone.

Effects of adrenomedullin gene overexpression on biological behavior of hepatic stellate cells

AIM: To investigate the effects of adrenomedullin (AM) gene overexpression on the biological characteristics of human hepatic stellate cells (hHSCs) by stable transfection.METHODS: hHSCs which express low basal levels of AM were stably transfected with an expression construct containing rat AM gene or with an empty expression vector. Expression of AM in hHSCs was determined by reverse transcription (RT)-polymerase chain reaction (PCR) and radioimmunoassay (RIA). Cell proliferation was evaluated by 5-bromo-2'-deoxyuridine (BrdU) incorporation and immunocytochemistry. RT-PCR and Western blot were used to test the expression of procollagen types Ⅰ and Ⅲ. Protein expressions of interstitial collagenase (MMP-1), gelatinase (MMP-2) and tissue inhibitors of matrix metalloproteinases-2 (TIMP-2) were assessed by Western blot.RESULTS: Two cell clones (A-2, A-8) transfected withthe AM gene expressed higher levels of AM mRNA (nontransfected group: 0.86±0.11, empty vector group: 1.01±0.11, A-2 clone group: 1.44±0.08 and A-8 clone group: 1.36±0.05) and protein (12.31±0.17, 12.35±0.12,12.56±0.06 and 12.62±0.07) (P＜0.05). AM geneoverexpression had inhibitory effects on cell proliferation of hHSCs (29.6%, 30.9%, 18.9% and 21.8%, respectively. P＜0.05) and expression of procollagen type Ⅰ (0.58±0.1,0.48±0.11, 0.3±0.06 and 0.31±0.07 at mRNA level)(0.27±0.07, 0.3±0.06, 0.14±0.05 and 0.13±0.05 at protein level) (P＜0.05) and procollagen type Ⅲ (0.17±0.04, 0.15±0.03, 0.1±0.02 and 0.09±0.02 at mRNA level) (0.22±0.04, 0.2±0.03, 0.11±0.04 and 0.13±0.03 at protein level) (P＜0.05). Compared with cells non-transfected (TIMp2: 2.77±0.03, MMP-2: 0.5±0.04, MMP-1: 0.49±0.07) and transfected with empty vector (TIMP2: 2.79±0.04,MMP-2: 0.48±0.03, MMP-1: 0.45±0.09), these two clones had lower expression levels of TIMP2(A-2 clone group: 2.7±0.02 and A-8 clone group: 2.71±0.02) (P＜0.05) and MMP-2(A-2 clone group: 0.15±0.05 and A-8 clone group: 0.13±0.04) (P＜0.05) but displayed a higher expression level of MMP-1(A-2 clone group: 0.68±0.06 and A-8 clone group: 0.81±0.09) (P＜0.05).CONCLUSION: AM gene exerts negative influence to some extent on hHSCs by inhibiting proliferation and production of extracellular matrix (ECM) in addition to inducing MMP-1 expression.

Adrenomedullin and diabetes

Adrenomedullin(ADM) is a peptide hormone widely expressed in different tissues, especially in the vasculature. Apart from its vasodilatatory and hypotensive effect, it plays multiple roles in the regulation of hormonal secretion, glucose metabolism and inflammatory response. ADM regulates insulin balance and may participate in the development of diabetes. The plasma level of ADM is increased in people with diabetes, while in healthy individuals the plasma ADM concentration remains low. Plasma ADM levels are further increased in patients with diabetic complications. In type 1 diabetes, plasma ADM level is correlated with renal failure and retinopathy, while in type 2 diabetes its level is linked with a wider range of complications. The elevation of ADM level in diabetes may be due to hyperinsulinemia, oxidative stress and endothelial injury. At the same time, a rise in plasma ADM level can trigger the onset of diabetes. Strategies to reduce ADM level should be explored so as to reduce diabetic complications.

THE CENTRAL DISTRIBUTION OF ADRENOMEDULLIN AND ITS EFFECTS ON BLOOD PRESSURE AND HEART RATE IN RATS

The present study was designed to make certain whether there exists adrenomedullin (ADM) in the rat central nervous system and evaluated the hemodynamic actions of intracerebroventricular administration (ICVA) of human ADM[13-52]. By immunohistochemistry (ABC method),We found that there was a discrete localization of ADM-positive immunoreactivity in the rat central system including cerebral cortex,paraventricular tissues, hypothalamus, cerebella cortex, mesencephalon and medulla oblongata. By reverse transcription-polymerase chain reaction(RT-PCR) analysis, rat ADM mRNA was found to be expressed in rat brain. These above results of immunohistochemistry and RT-PCR suggest that ADM exists in the rat brain. We also found that centrally administered ADM[13-52]in a dose of 0.4 to 3. 2 nmol/kg provoked marked, prolonged and dosedependent increases in mean arterial blood pressure (MABP) and heart rate (HR). To clarify the mechanisms of the hemodynamic changes induced by centrally administered ADM [13-52]. the effect of centrally administered ADM [13-52] on renal sympathetic nerve activity (RSNA) was studied. The result showed that centrally administered ADM [13-52] ( 1. 6 nmol/kg) provoked a marked increase in RSNA .therefore .the increases in MABP and HR induced by centrally administered ADM [13-52]might be due to the stimulation of central sympathetic mechanism. In addtion,we also compared the relationship of activity and structure among the different fragments of ADM. In conclusion, ADMexists in the rat brain, and it may play an important role in the central control of cardiovascular system.

败血症休克大鼠血浆和心血管组织中Adrenomedullin与Intermedin的变化

目的探讨腹膜炎败血症休克大鼠血肾上腺髓质素(ADM)和IMD的变化。方法在SD大鼠用结扎肓肠和穿孔的方法复制大鼠腹膜炎败血症休克模型,术后10h为早期败血症(ES),术后20h为晚期败血症大鼠(n=7)血浆ADM和IMD分别增加196.5%和609.3%(P&lt:0.001),主动脉含量分别增加30%和75.2%(P【0.01),左心室含量分别高67.1%和36.2%(P均【0.01);与休克早期大鼠相比较,晚期败血症大鼠血浆ADM和IMD分别增加31.5%和60.6%(P均&It;0.001),胸主动脉ADM增高32.8%,IMD降低23.5%(P分别&It;0.05和0.01),左心室ADM增加42.5%,IMD减少74.2%(P分别&It;0.05和0.01)。休克早晚期血浆、动脉和心脏ADM/IMD均增加(P均【0.05)。结论ADM和IMD在败血症休克大鼠血浆和心血管组织中显著增加,参与了休克的病理生理过程。

妊娠高血压疾病患者血浆Intermedin/Adrenomedullin-2水平变化

目的观察妊娠高血压疾病妇女血浆Intermedin/Adrenomedullin-2(IMD/ADM2)水平变化,探讨IMD/ADM2在妊娠高血压疾病发病中的可能作用。方法妊娠高血压疾病患者40例(PIH组);适龄未孕妇女20例(NG组)及正常妊娠妇女20例(PG组)分别采其静脉血;用放射免疫法测定血浆IMD/ADM2水平。结果 (1)血浆IMD/ADM2水平PIH组、NG组、PG组分别为37.6±11.5、64.7±10.4、58.3±10.6pg/ml;PIH组与NG组及PG组比较均有统计学差异(P<0.05);NG组与PG组比较无统计学差异,(P>0.05)。(2)PIH血浆IMD/ADM2水平与平均动脉压呈负相关(r=-0.78,P<0.01);与尿蛋白呈负相关(r=-0.56,P<0.05)。结论 IMD/ADM2在妊娠高血压疾病患者血浆浓度的变化,提示其可能在正常妊娠及妊娠高血压疾病的发病机制中有重要的生理、病理生理意义。

hypotensive effedts and mechansms of adrenomedullin(13─52)

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Changes and role of adrenomedullin in diabetic nephropathy

Objective:To investigate the role and mechanism of adrenomedullin(AM) in diabetic nephropathy. Methods: This research observed the changes of the expression and secretion of AM,TGF-β1 in the cultured human mesangial cells under high glucose conditions and the contents of the laminin and type Ⅳ collagen in the supernatants,and the effect of intervention with AM on the changes. Results: High glucose condition resulted in increase in the expression and secretion of AM, TGF-β1,laminin and type Ⅳ collagen, and AM could reverse the influence of high glucose on the cultured human mesangial cells. Conclusion: The results showed that high glucose condition in one of the stimulating factors of AM,and the renal protective action of AM may be associated with suppression of TGF-β1 and reducing excessive accumulation of laminin and type Ⅳ collagen.

Effect and mechanism of adrenomedullin on apoptosis of renal tubular epithelial cell in rats induced by renal ischemia reperfusion injury

Objective To investigate the effect and mechanism of adrenomedullin ( AM ) on apoptosis of renal tubular epithelial cell in rats induced by renal ischemia reperfusion injury. Methods Thirty-two Wistar rats were randomly divided into 4 groups: control group,IRI group, empty plasmid group and AM group. One week after re-

Inflammation: Complexity and significance of cellular and molecular responses

Inflammation is a multifaceted cellular and molecular response triggered by injury,infection,or various pathological conditions.Serving as a protective defense mechanism,the inflammatory response involves clinical signs like redness,swelling,pain,and increased body temperature.Immune cells,notably neutrophils and macrophages,play key roles in orchestrating this response.The delicate balance between proinflammatory and anti-inflammatory mediators,including cytokines and chemokines,regulates the inflammatory cascade.While acute inflammation is crucial for tissue repair,chronic inflammation may indicate an imbalance,contributing to conditions like autoimmune diseases.Understanding these mechanisms is vital for developing therapeutic strategies and managing chronic diseases.

肾上腺髓质素前体中段肽联合血清降钙素原在脓毒症诊疗中的应用

目的分析肾上腺髓质素前体中段肽(MR-proADM)联合降钙素原(PCT)检测在脓毒症诊疗中的应用价值。方法回顾性选取2020年1月~2023年6月南通市中医院收治的45例脓毒症患者为脓毒症组,同期选取43例健康体检者为健康对照组。入组者均于入院24 h内检测血清MR-proADM、PCT水平,脓毒症组以是否为休克脓毒症分为休克组(20例)与非休克组(25例),以不同预后情况分为死亡组(5例)与存活组(40例)。比较健康对照组与脓毒症组MR-proADM、PCT水平,同时比较各亚组MR-proADM、PCT水平,并分析MR-proADM、PCT指标单一检测与联合检测对脓毒症的预测价值。结果脓毒症组MR-proADM、PCT水平较健康对照组更高,差异有统计学意义(t=83.306、35.745,P<0.05);休克组MR-proADM、PCT水平较非休克组更高,差异有统计学意义(t=24.867、2.149,P<0.05);死亡组MR-proADM、PCT水平较存活组更高,差异有统计学意义(t=15.458、2.174,P<0.05)。联合检测用于预测脓毒症的ROC曲线下面积(AUC)较MR-proADM、PCT单一检测更高(P<0.05)。结论MR-proADM联合PCT检测用于脓毒症诊疗,可为疾病诊治提供可靠依据,并可用于评估预后。

Adrenomedullin and endocrine control of immune cells during pregnancy

The immunology of pregnancy is complex and incompletely understood. Aberrant immune activity in the decidua and in the placenta is believed to play a role in diseases of pregnancy, such as infertility, miscarriage, fetal growth restriction and preeclampsia. Here, we briefly review the endocrine control of uterine natural killer cell populations and their functions by the peptide hormone adrenomedullin. Studies in genetic animal models have revealed the critical importance of adrenomedullin dosage at the maternal-fetal interface, with cells from both the maternal and fetal compartments contributing to essential aspects underlying appropriate uterine receptivity, implantation and vascular remodeling of spiral arteries. These basic insights into the crosstalk between the endocrine and immune systems within the maternal- fetal interface may ultimately translate to a better understanding of the functions and consequences of dysregulated adrenomedullin levels in clinically complicated pregnancies.

Effects of high-flux hemodialysis on plasma adrenomedullin and sustained hypotension in elderly hemodialysis patients

Background Sustained hypotension during hemodialysis （HD） is an important clinical issue. Plasma adrenomedullin （AM） is increased in HD patients with sustained hypotension, but little is known about whether removing AM can improve hypotension. The objective of this study was to investigate the beneficial effects of hemodialysis using a high-flux dialyzer on removal of increased plasma AM levels and improving low blood pressure in elderly HD patients with sustained hypotension.Methods Forty-eight elderly patients （age 65 or older） who had undergone maintenance HD for more than one year were recruited and studied. We evaluated plasma levels of AM in sustained hypotension （SH; n=28） and normotensive （NT; n=20） patients. The patients with hypotension were further divided into two subgroups and treated with eitherhigh-flux dialyzer or low-flux dialyzer for 3 months. Plasma adrenomedullin levels and blood pressure were analyzed at days 0 and 181.Results Plasma levels of AM were significantly higher in SH than in NT patients （（24.92±3.7） ng/L vs. （15.52±6.01） ng/L,P〈0.05）, and were inversely correlated with mean arterial blood pressure （MAP） at pre-HD. After 3 months, the level of plasma AM in high-flux group was decreased （（24.58±4.36） ng/L vs. （16.18±5.08） ng/L, P 〈0.05）, but MAP was increased （（67.37±4.31） mmHg vs. （74.79±3.59） mmHg, P〈0.05）. There was no obvious change in low-flux group.Conclusions Plasma AM levels were significantly elevated in elderly HD patients with SH. High-flux dialyzer therapy can decrease plasma AM level and improve hypotension.