Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pentoxifylline (PTX) has recently been shown to modulate TNF-alpha production and to reduce the incidence and severity of all major complications after BMT, including mucositis, veno-occlusive disease, renal insufficiency, hypertension, and graft-versus-host disease. To analyze in detail the effect of PTX on immune complications after BMT, we investigated the immunomodulatory effect of PTX on immune responses in vitro. The continuous presence of PTX significantly reduced the proliferative response of PBMC to PHA stimulation and to alloantigens in a dose-dependent manner. Starting at concentrations of 100 micrograms/ml, PTX was able to inhibit and, at 1000 micrograms/ml, completely block mitogen-induced proliferation. Maximal inhibition of more than 90% (91 +/- 4%) was also observed at PTX concentrations of 1000 micrograms/ml in the mixed lymphocyte culture (MLR) and by addition on day 0. However, lower but still significant suppression (13 +/- 7%) was achieved at concentrations of 10 micrograms/ml PTX. The inhibitory capacity of PTX was increased by mAbs against TNF-alpha (34 +/- 5% additional suppression at 100 micrograms/ml PTX) and not reversed by the addition of rTNF-alpha. The effect of PTX on the generation of CTLs in vitro was studied in the cell-mediated lymphotoxicity assay. PTX (100 micrograms/ml) significantly inhibited (P = 0.0178) the in vitro generation of CTLs when PTX was added to the culture on day 0. PTX also showed profound modulatory properties in the NK assay, with a reduction of 23 +/- 3% in specific lysis at 10 micrograms/ml PTX and maximal reductions of 88 +/- 3% at 1000 micrograms/ml PTX. Immunomodulatory properties of PTX were not only associated with blockage of TNF-alpha, as shown by decreased mRNA expression and TNF-alpha values in the culture supernatants, but also with an impaired production of other cytokines and secondary messages such as IFN-gamma and neopterin. PTX treatment, however, did not affect IFN-alpha or IL-1 beta production, and IL-6 release was even increased. PTX, therefore, has profound immunomodulatory properties in vitro, which are associated with selective inhibition of cytokine release and can be enhanced by the addition of mAbs against TNF-alpha, but not reversed by the addition of rTNF-alpha.
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PMID:Immune response modulation by pentoxifylline in vitro. 833 42

There is growing evidence that T-lymphocyte dysfunction contributes to the development of hypertension. IL-4 and IFN-gamma are important regulators of T-lymphocyte function. Therefore, we investigated the effect of neutralizing antibodies against IL-4 (alpha-IL-4) and IFN-gamma (alpha-IFN-gamma) on the development of hypertension in NZBNZWF1 hybrid compared to normotensive NZW control mice. Antibody-producing cells were encapsulated and injected intraperitoneally in mice at 6,8 and 10 weeks of age. This treatment resulted in significant levels of antibody in the serum. At 12 weeks of age blood pressure was recorded under anesthesia. Mean arterial blood pressure (MAP) increased in NZBNZWF1 hybrids between the age of 6 and 12 weeks. This increase was inhibited by treatment with alpha-IL-4, but was not affected by alpha-IFN-gamma. Treatment with alpha-IL-4 did not influence MAP in normotensive NZW or C57B1/6J mice. However, in these mice, treatment with alpha-IFN-gamma increases MAP. This increase in MAP by alpha-IFN-gamma was prevented by simultaneous treatment with alpha-IL-4. The present study demonstrates the influence of endogenous IL-4 and IFN-gamma on blood pressure.
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PMID:Opposite role of interferon-gamma and interleukin-4 on the regulation of blood pressure in mice. 992 Aug 23

Seventeen patients stung by Tityus serrulatus scorpion were classified as mild (pain at the site of the sting, n = 6), moderate (local pain and one of the following manifestations: vomiting, psychomotor agitation, prostration, sweating, tachypnea, tachycardia and mild arterial hypertension, n = 10) and severe cases (equal moderate cases plus cardiac failure, pulmonary edema and shock, n = 1). Venous blood was sampled for biochemical and hematological analysis and for IL-1alpha, IL-6, IL-10, TNF-alpha, IFN-gamma and GM-CSF ELISAs at the time of hospital admission, 6 h (moderate and severe cases), and 12, 18, 36 and 72 h (severe case) later. Ten age-matched healthy volunteers were used as control. Increased serum levels of IL-1alpha was noticed in all patients, high levels of IL-6, IFN-gamma and GM-CSF were observed only in a patient with severe envenomation. Our data suggest that a systemic inflammatory response-like syndrome is triggered during severe envenomation caused by T. serrulatus sting and that release of cytokines may be involved in this response.
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PMID:Serum levels of cytokines in patients envenomed by Tityus serrulatus scorpion sting. 1040 Feb 99

Angiotensin (Ang) II stimulates proliferation of vascular smooth muscle cells (VSMC) via its specific receptor AT1 subtype, possibly leading to atherosclerosis in hypertension. On the other hand, a cytokine interferon (IFN)-gamma has been shown to have an anti-atherosclerotic effect. In the present study, we examined a possible role of IFN-gamma in AT1 receptor gene regulation in VSMC. A firefly luciferase expression vector driven by the rat AT1a receptor gene promoter ( approximately 3.2 kb) was transfected into the cultured rat VSMC, and luciferase expression was determined to estimate the transcription function of the AT1a receptor gene promoter. RT-PCR was also carried out to determine mRNA expression of AT1a receptor in VSMC. IFN-gamma treatment decreased AT1a receptor mRNA expression as well as luciferase expression in a dose-dependent manner. The analysis with deletion DNA fragments showed that the IFN-responsive element was located between -987 and -331 positions, where multiple GAS (gamma interferon activated site)-like elements were identified. The expression suppression was reversed by either a MAPKK inhibitor PD98059 or a Jak-2 inhibitor AG-490. These results suggest that IFN-gamma can inhibit AT1 receptor expression at gene transcription level, and that the transcription suppression is dependent on MAP kinase and Jak-2. Inhibition of AT1a receptor expression may possibly be implicated in the anti-atherosclerotic action of IFN-gamma in VSMC.
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PMID:Transcriptional suppression of rat angiotensin AT1a receptor gene expression by interferon-gamma in vascular smooth muscle cells. 1046 2

In addition to established factors such as hyperlipidemia, smoking and hypertension, inflammation and infection have recently been implicated as major risk factors for atherosclerotic disease. Proatherogenic effects induced by infection may be related to both systemic inflammation and to direct effects on the vascular wall. We report here that a high fat diet combined with a protozoal infection with known tropism to the heart induced early atherosclerosis and intimal inflammatory infiltrates (CD4+, CD8+ cells and macrophages) in aortas of all (n = 7) CBA/J mice investigated. These mice are normally quite resistant to atherosclerotic development and in the control group (n = 7) receiving only a fatty diet, only one mouse presented a lesion. This lesion was completely devoid of infiltrating CD8+ cells. Parasite-infected mice receiving a normal diet exhibited vasculitis, but no signs of atherosclerosis and control mice receiving normal diet, as expected, exhibited neither signs of vasculitis nor atherosclerosis. Secretion of IL-6, TNF-alpha, and IFN-gamma were demonstrated in all atherosclerotic lesions and IL-6 appeared to be the dominant cytokine, both in the lesions themselves as well as in the intimal-medial junction. There were no traces of parasites present in the artery wall, indicating that atherosclerosis was induced via an indirect route. We conclude that a high fat diet in conjunction with infection and systemic (or localized) inflammation may have a strong proatherogenic effect. Finally, we suggest that CBA/J mice infected with T. cruzi parasites and given a fatty diet could serve as a useful experimental model in the continued analysis of factors contributing to the induction of atherosclerosis.
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PMID:Induction of early atherosclerosis in CBA/J mice by combination of Trypanosoma cruzi infection and a high cholesterol diet. 1116 16

To explore the mechanisms of adrenomedullin (ADM) regulation in normal and preeclamptic (PE) states, we determined placental production of ADM and ADM regulation by cytokines. Isolated, purified cytotrophoblast cultures from normal (n=8) and PE (n=10) placentas were cultured for 3 days in the absence or presence of 10 ng/mL epidermal growth factor (EGF), 1 ng/mL transforming growth factor (TGF)-beta1, 10 ng/mL tumor necrosis factor (TNF)-alpha, or 100 U/mL interferon (IFN)-gamma. Cells were also cultured for 3 days in 10% fetal bovine serum for determination of syncytial formation by desmoplakin staining. Pieces of normal and PE placentas were snap-frozen for ADM mRNA measurement. Results showed that basal ADM production into culture medium by radioimmunoassay was significantly lower in PE placental cells. EGF significantly stimulated ADM production in normal trophoblasts but did not in PE placentas. None of the factors TNF-alpha, TGF-beta1, or IFN-gamma altered ADM secretion in either normal or PE placentas. ADM expression by Northern blot analysis demonstrated a 34.3+/-8.3% reduction in mRNA expression in PE placentas. Syncytialization, as assessed by desmoplakin-outlined syncytial units, was decreased in PE placentas (day 3: normal, 16.7+/-1.3%; PE, 5.5+/-2.0%; P<0.01, ANOVA). However, there was a normal increment in syncytialization in response to EGF in normal and PE trophoblast preparations (EGF day 3: normal, 43.8+/-5.6%; PE, 46.1+/-12.3%). We conclude that spontaneous placental syncytialization is impaired in PE and that ADM production is markedly reduced in PE, possibly owing to an impaired EGF response. These abnormalities indicate poor placental production of ADM as the likely cause of a failed compensatory increase in maternal serum ADM levels in PE.
Hypertension 2003 Nov
PMID:Adrenomedullin is decreased in preeclampsia because of failed response to epidermal growth factor and impaired syncytialization. 1451 25

Rupture of vulnerable plaques is the main cause of acute cardiovascular events. However, mechanisms responsible for transforming a stable into a vulnerable plaque remain elusive. Angiotensin II, a key regulator of blood pressure homeostasis, has a potential role in atherosclerosis. To study the contribution of angiotensin II in plaque vulnerability, we generated hypertensive hypercholesterolemic ApoE-/- mice with either normal or endogenously increased angiotensin II production (renovascular hypertension models). Hypertensive high angiotensin II ApoE-/- mice developed unstable plaques, whereas in hypertensive normal angiotensin II ApoE-/- mice plaques showed a stable phenotype. Vulnerable plaques from high angiotensin II ApoE-/- mice had thinner fibrous cap (P<0.01), larger lipid core (P<0.01), and increased macrophage content (P<0.01) than even more hypertensive but normal angiotensin II ApoE-/- mice. Moreover, in mice with high angiotensin II, a skewed T helper type 1-like phenotype was observed. Splenocytes from high angiotensin II ApoE-/- mice produced significantly higher amounts of interferon (IFN)-gamma than those from ApoE-/- mice with normal angiotensin II; secretion of IL4 and IL10 was not different. In addition, we provide evidence for a direct stimulating effect of angiotensin II on lymphocyte IFN-gamma production. These findings suggest a new mechanism in plaque vulnerability demonstrating that angiotensin II, within the context of hypertension and hypercholesterolemia, independently from its hemodynamic effect behaves as a local modulator promoting the induction of vulnerable plaques probably via a T helper switch.
Hypertension 2004 Sep
PMID:Endogenous angiotensin II induces atherosclerotic plaque vulnerability and elicits a Th1 response in ApoE-/- mice. 1530 40

Ang II (Angiotensin II) has been shown to play a pivotal role in the pathophysiology of various organs, especially the cardiovascular system. The effects of ARBs (Ang II receptor blockers) in the treatment of hypertension, congestive heart failure and myocardial fibrosis have been analysed extensively in human trials, as well as animal models, and the focus of interest is now directed to its pleiotropic effects, especially on inflammatory disorders. To investigate the effects of a new ARB, olmesartan, on immune-mediated myocardial injury, the protective effects of olmesartan on the development of murine acute myocarditis caused by CVB3 (coxsackievirus B3) were analysed. Olmesartan and a non-specific vasodilator hydralazine lowered systolic blood pressure of mice on day 7 after virus inoculation to a similar extent. Olmesartan significantly decreased myocardial inflammation compared with controls, whereas hydralazine significantly increased this. Olmesartan significantly decreased the expression of IFN-gamma (interferon-gamma), FasL (Fas ligand), iNOS (inducible nitric oxide synthase) and PFP (pore-forming protein) in myocardial tissue, indicating that olmesartan suppressed the activation of infiltrating killer lymphocytes. Olmesartan also decreased the expression of CVB3 genomes in myocardial tissue as well as serum levels of 8-OHdG (8-hydroxy-2'-deoxyguanosine), a biomarker of oxidative-stress-induced DNA damage. The findings suggest that olmesartan prevents myocardial damage and may improve the prognosis of patients with acute myocarditis; however, further investigations are needed before clinical use.
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PMID:Effect of the angiotensin II receptor blocker olmesartan on the development of murine acute myocarditis caused by coxsackievirus B3. 1633 7

NK cells are a key component of innate immune systems, and their activity is regulated by cytokines and hormones. Adiponectin, which is secreted from white adipose tissues, plays important roles in various diseases, including hypertension, cardiovascular diseases, inflammatory disorders, and cancer. In this study the effect of adiponectin on NK cell activity was investigated. Adiponectin was found to suppress the IL-2-enhanced cytotoxic activity of NK cells without affecting basal NK cell cytotoxicity and to inhibit IL-2-induced NF-kappaB activation via activation of the AMP-activated protein kinase, indicating that it suppresses IL-2-enhanced NK cell cytotoxicity through the AMP-activated protein kinase-mediated inhibition of NF-kappaB activation. IFN-gamma enhances NK cell cytotoxicity by causing an increase in the levels of expression of TRAIL and Fas ligand. The production of IFN-gamma, one of the NF-kappaB target genes in NK cells, was also found to be suppressed by adiponectin, accompanied by the subsequent down-regulation of IFN-gamma-inducible TRAIL and Fas ligand expression. These results clearly demonstrate that adiponectin is a potent negative regulator of IL-2-induced NK cell activation and thus may act as an in vivo regulator of anti-inflammatory functions.
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PMID:Adiponectin is a negative regulator of NK cell cytotoxicity. 1667 Mar 4

Obesity is becoming one of the most serious public health problems in industrialized societies, due to the profound changes in lifestyle, and notably in nutrition. Beside diabetes, cardiovascular diseases or hypertension, increased susceptibility to infection is one of the pathological consequences of being overweight. In this paper, we have assessed the influence of a high-fat diet (HFD) rich in saturated fatty acids on the immune system of DO11.10 mice, which are transgenic for a T-cell receptor specifically recognizing a peptide of ovalbumin. We showed that the specific T-cell immune response was impaired by high-fat feeding, and that the expression of this defect is different depending on whether T cells are naive or Ag experienced. Indeed, on in vitro ovalbumin stimulation, spleen T cells from naive HFD-fed transgenic mice showed proliferation similar to that of cells from standard diet (SD)-fed mice, but exhibited a strong inflammatory profile as shown by the markedly increased IFN-gamma/IL-4 ratio. Inversely, spleen T cells from ovalbumin-immunized HFD mice were impaired in their Ag-dependent proliferation compared to cells from SD mice. By co-culture experiments, we showed that both T cells and antigen-presenting cells were involved in this impairment. Moreover, in ovalbumin-immunized HFD animals, a trend towards Th2 response was noted, compared to immunized SD mice. This data implies that naive T cells could participate actively in the low-grade systemic inflammation observed in overweight patients. Moreover, the impaired activity of Ag-experienced T cells could have major consequences both in defence against infection and/or in vaccination protocols.
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PMID:Influence of high-fat feeding on both naive and antigen-experienced T-cell immune response in DO10.11 mice. 1703 37


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