Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0004135 (ATM)
 13,001 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pathophysiology of the diabetic kidney (e.g., hypertrophy, increase urinary albumin excretion (UAE) is still ill-defined. Parathyroid hormone-related protein (PTHrP) is overexpressed in several nephropathies, but its role remains unclear. We evaluated the effect of high glucose on PTHrP and the PTH1 receptor (PTH1R) protein (by Western blot and immunohistochemistry) in the kidney of mice ith streptozotocin-induced diabetes, and in several mouse renal cells in vitro. Diabetic mice showed a significantly increased renal expression of PTHrP and PTH1R proteins with 2-8 weeks from the onset of diabetes. These animals exhibited an intense immunostaining for both proteins in the renal tubules and glomeruli. Using transgenic mice overexpressing PTHrP targeted to the renal proximal tubule, we found a significant increase in the renal hypertrophy index and in UAE in these diabetic mice relative to their control littermates. Moreover, logistic regression analysis showed a significant association between both PTHrP and PTH1R protein levels and UAE in all diabetic mice throughout the study. High-glucose (25 mm) medium was found to increase PTHrP and PTH1R in tubuloepithelial cells, mesangial cells and podocytes in vitro. Moreover, this increase in PTHrP (but not that of PTH1R) was inhibited by the AT1 receptor antagonist losartan. Collectively, these results indicate that the renal PTHrP/PTH1R system is upregulated in streptozotozin-induced diabetes in mice, and appears to adversely affect the outcome of diabetic renal disease. Our findings also suggest that angiotensin II might have a role in the PTHrP upregulation in this condition.
 ...
PMID:The parathyroid hormone-related protein system and diabetic nephropathy outcome in streptozotocin-induced diabetes. 1678 82

The treatment and management of patients with arterial hypertension depends on the global cardiovascular risk of the individual patient. Thus, additional cardiovascular risk factors, the presence of target organ damage, cardiovascular or renal disease determine not only the initiation of therapy but also the choice of drug(s). Drug treatment is usually started with one compound, which is selected from 5 drug classes recommended for first-line therapy including ACE-inhibitors, AT1-antagonists, betablockers, calcium channel blockers, and diuretics. Depending on risk and additional disease individual target blood pressures are 140/90, 130/80 or 125/75 mmHg, respectively. If blood pressures at baseline exceeds target values more than 20/10 mmHg treatment may be started with initial or early combination therapy of two drugs. Overall, approximately two-thirds of patients require treatment with at least two drugs to achieve target blood pressure values.
 ...
PMID:[Therapy of hypertension]. 1701 83

Microalbuminuria (MA), conventionally defined as a urinary albumin excretion (UAE) of 30-300 mg/day, is recognised as a marker of endothelial dysfunction. Furthermore, it represents an established risk factor for cardiovascular morbidity and mortality and for end-stage renal disease in individuals with an adverse cardiovascular risk profile. It is common in the general population, particularly in patients with diabetes mellitus or arterial hypertension. There is growing evidence from prospective observational trials that UAE levels well below the current MA threshold ("lowgrade MA") are also associated with an increased risk of incident cardiovascular disease and allcause mortality. Even in apparently healthy individuals (without diabetes or hypertension), such an association has been shown. As albuminuria screening assays that are reliable even in the lower ranges are commercially available, there may be an important clinical role for MA in disease screening, comparable to the role of blood pressure and lipid screening. MA is modifiable, and the inhibition of the renin-angiotensin system by ACE inhibitors and AT1 receptor antagonists has been shown to result in a lower incidence of cardiovascular events.
 ...
PMID:Low-grade albuminuria and cardiovascular risk : what is the evidence? 1745 40

Angiotensin II (Ang II) has powerful sodium-retaining, growth-promoting and pro- inflammatory properties in addition to its physiological role in maintaining body salt and fluid balance and blood pressure homeostasis. Increased circulating and local tissue Ang II is one of the most important factors contributing to the development of sodium and fluid retention, hypertension and target organ damage. The importance of Ang II in the pathogenesis of hypertension and target organ injury is best demonstrated by the effectiveness of angiotensin- converting enzyme (ACE) inhibitors and AT1-receptor antagonists in treating hypertension and progressive renal disease including diabetic nephropathy. The detrimental effects of Ang II are mediated primarily by the AT1-receptor, while the AT2-receptor may oppose the AT1-receptor. The classical view of the AT1-receptor-mediated effects of Ang II is that the agonist binds its receptors at the cell surface, and following receptor phosphorylation, activates downstream signal transduction pathways and intracellular responses. However, evidence is emerging that binding of Ang II to its cell surface AT1-receptors also activates endocytotic (or internalisation) processes that promote trafficking of both the effector and the receptor into intracellular compartments. Whether internalised Ang II has important intracrine and signalling actions is not well understood. The purpose of this article is to review recent advances in Ang II research with focus on the mechanisms underlying high levels of intracellular Ang II in proximal tubule cells and the contribution of receptor-mediated endocytosis of extracellular Ang II. Further attention is devoted to the question whether intracellular and/or internalised Ang II plays a physiological role by activating cytoplasmic or nuclear receptors in proximal tubule cells. This information may aid future development of drugs to prevent and treat Ang II-induced target organ injury in cardiovascular and renal diseases by blocking intracellular and/or nuclear actions of Ang II.
 ...
PMID:Novel roles of intracrine angiotensin II and signalling mechanisms in kidney cells. 1748 23

Significant reduction of renal mass triggers a chain of events that result in glomerular hypertension/hyperfiltration, proteinuria, glomerulosclerosis, tubulointerstitial injury, and end-stage renal disease. These events are mediated by a constellation of hemodynamic, oxidative, and inflammatory reactions that are, in part, driven by local AT1 receptor (AT1r) activation by angiotensin II (Ang II). Here we explored the effects of 5/6 nephrectomy with and without AT1r blockade (losartan for 8 weeks) on AT1r and AT2r and Ang II-positive cell count, pathways involved in oxidative stress and inflammation [NAD(P)H oxidase, nuclear factor kappaB (NFkappaB), 12-lipooxygenase, cyclooxygenase (COX)-1, COX-2, monocyte chemoattractant protein (MCP)-1, plasminogen activator inhibitor (PAI)-1, renal T cell, and macrophage infiltration] as well as renal function and structure. The untreated group exhibited hypertension, deterioration of renal function and structure, reduced or unchanged plasma renin activity, aldosterone concentration, marked up-regulations of AT1r (250%), Ang II-expressing cell count (>20-fold), NAD(P)H oxidase subunits (gp91(phox,) p22(phox), and P47(phox); 20-40%), COX-2 (250%), 12-lipooxygenase (100%), MCP-1 (400%), and PAI-1 (>20-fold), activation of NFkappaB, and interstitial infiltrations of T cells and macrophages in the remnant kidneys. AT1r blockade attenuated the biochemical and histological abnormalities, prevented hypertension, and decelerated deterioration of renal function and structure. Thus, the study demonstrated a link between up-regulation of Ang II/AT1r system and oxidative stress, inflammation, hypertension, and progression of renal disease in rats with renal mass reduction.
 ...
PMID:Intra-renal angiotensin II/AT1 receptor, oxidative stress, inflammation, and progressive injury in renal mass reduction. 1763 6

Angiotensin II and its type 1 receptor (AT1R) play important roles in the pathogenesis of renal disease and diabetic nephropathy. The 12/15-lipoxygenase pathway of arachidonate metabolism and its lipid products have also been implicated in diabetic nephropathy. However, it is unclear whether 12/15-lipoxygenase regulates expression of AT1R. In cultured rat mesangial cells, we found that the 12/15-lipoxygenase product 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE) increased AT1R mRNA and protein expression, primarily by stabilizing AT1R mRNA. Pretreatment with 12(S)-HETE also amplified the signaling effects of angiotensin II, likely due to the increased AT1R expression. Levels of AT1R protein expression decreased when 12/15-lipoxygenase was knocked down with specific short hairpin RNA (shRNA) compared with control cells. Similarly, levels of the AT1 receptor, but not the AT2 receptor, were significantly lower in mesangial cells and glomeruli derived from 12/15-lipoxygenase knockout mice compared with control mice. Reciprocally, stable overexpression of 12/15-lipoxygenase increased AT1R expression in cultured mesangial cells. In vivo, modified siRNA targeting 12/15-lipoxygenase reduced glomerular AT1R expression in a diabetic mouse model. Interestingly, angiotensin II induced greater levels of 12/15-lipoxygenase, TGF-beta1, and fibronectin (FN) in AT1R-overexpressing mesangial cells compared with control cells. Therefore, oxidized lipids generated by the 12/15-lipoxygenase-mediated metabolism of arachidonic acid can enhance AT1R expression in mesangial cells and augment the profibrotic effects of angiotensin II.
 ...
PMID:Products of 12/15-lipoxygenase upregulate the angiotensin II receptor. 1823 84

Initial attempts to inhibit renin in humans have faced numerous difficulties. Molecular modeling and X-ray crystallography of the active site of renin have led to the development of new orally active renin inhibitors such as aliskiren. Aliskiren has a low bioavailability (2.6% to 5%) compensated by its high potency to inhibit renin and a long plasma half-life (24 to 40 h), which makes it suitable for once-daily dosing. The once-daily administration of aliskiren to hypertensive patients lowers blood pressure as strongly as standard doses of established AT1 receptor blockers (losartan, valsartan, and irbesartan), angiotensin-converting enzyme inhibitors (ramipril and lisnopril), hydrochlorothiazide, or long-acting calcium channel blockers (amlodipine). In combination therapy, aliskiren further decreases blood pressure when combined with either hydrochlorothiazide, amlodipine, valsartan, irbesartan, or ramipril. However, the biochemical consequences of renin inhibition differ from those of angiotensin I-converting enzyme inhibition and angiotensin II antagonism, particularly in terms of angiotensin profiles and interactions with the bradykinin-NO-cGMP pathway. Blockade of the renin-angiotensin system with angiotensin I-converting enzyme inhibitors, AT1 receptor blockers, or a combination of these drugs has become one of the most successful therapeutic approaches in medicine. However, it remains unclear how to optimize renin-angiotensin system blockade to maximize cardiovascular and renal benefits. In this context, renin inhibition to render the renin-angiotensin system fully quiescent is a new possibility requiring further study. Preliminary results show that short-term administration of aliskiren has beneficial anti-albuminuric effects in diabetic patients with chronic nephropathy and favorable neurohormonal effects in patients with chronic heart failure.
 ...
PMID:Direct renin inhibition: clinical pharmacology. 2223 43

Angiotensin-converting enzyme (ACE) inhibitors and AT1 receptor blockers have long been considered as two classes of drugs with strictly comparable effect in cardiovascular diseases, on the assumption that both classes act on the renin-angiotensin-aldosterone system. The results of large clinical intervention trials, which failed to demonstrate any significant difference between the effects of these two pharmacological classes in patients with essential hypertension, acute myocardial infarction and heart failure, supported this concept. The recent observation that a combination of ACE-inhibitors and AT1 receptor blockers improves the prognosis of these pathological conditions better than monotherapy at higher doses focused on the difference between their mechanisms of action. The results of pathophysiological studies have suggested that in the heart, as well as in the kidney, AT1 receptor blockers act in the early stages of the disease, improving left ventricular dysfunction in hypertensive patients and preventing microalbuminuria in diabetic animals. It seems reliable to suggest that AT1 receptor blockers are to be preferred to ACE-inhibitors for an early prevention of cardiovascular and renal disease. The new inhibitors of renin activity may further amplify our chances, also blocking the negative effects mediated by angiotensin II escape and by stimulation of the prorenin/renin receptors.
 ...
PMID:[Renin-angiotensin system modulation: instructions for use]. 1838 70

The renin-angiotensin-aldosterone system (RAAS) play a pivotal role in the progression of renal disease. The RAAS has become much more complex in recent years with the identification of novel peptides that exhibit biological activity. There are novel pathways of angiotensin II (ANG II) generation independent of angiotensin converting enzyme (ACE). ANG II bind to at least two different receptors and prorenin/renin also exerts pathophysiological effects through binding to specific receptor. ANG II itself has emerged as a multifunctional cytokine exhibiting many non-hemodynamic properties such as acting as a growth factor and profibrogenic and proinflammatory cytokine. These profibrogenic and proinflammatory effects are mediated by other factors such as transforming growth-factor beta (TGF-beta) and chemoattractants that are induced in the kidney by ANG II. Increased aldosterone levels contribute to renal injury, independent of blood pressure or ANG II. Numerous experimental and clinical studies have shown that ACE-inhibitors as well as AT1-receptor antagonists can prevent glomerulosclerosis and tubulointerstitial fibrosis. This review will highlight some of these novel insights into the RAAS in regards to renal injury.
 ...
PMID:Novel aspects of the renin-angiotensin-aldosterone-system. 1850 64

The blockade of the renin-angiotensin-aldosterone system (RAAS) has been shown to be useful, or even mandatory, in the management of arterial hypertension, congestive heart failure, post-myocardial infarction and nephropathy with albuminuria, due to diabetes or not. Such blockade can be obtained with an angiotensin converting enzyme inhibitor, a specific antagonist of angiotensin II AT1 receptors and/or recently a direct inhibitor of renin such as aliskiren. Various studies have demonstrated the advantage of optimising RAAS blockade in order to benefit of the best cardiorenal protection. The present article describes the various modalities to optimize the RAAS blockade, either by using a maximal dosage of a monotherapy, or by choosing a double inhibition of RAAS. New prospects for the RAAS blockade will be also briefly considered.
 ...
PMID:[How I treat... by optimizing the blockade of the renin-angiotensin-aldosterone system]. 1857 70


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>