Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q8NEX9 (reductase)
 26,410 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Prostatic differentiation during embryogenesis and its further homeostatic state maintenance during adult life depend on androgens. Dihydrotestosterone, which is synthesized from testosterone by 5 alpha-reductase (5 alpha-r), is the active molecule triggering androgen action within the prostate. In the present work, we examined the effects of 5 alpha-reductase inhibition by finasteride in the ventral prostate (VP) of the adult gerbil, employing histochemical and electron microscopy techniques to demonstrate the morphological and organizational changes of the organ. After 10 days of finasteride treatment at a dose of 100 mg/kg/day, the prostatic complex (VP and dorsolateral prostate) absolute weight was reduced to about 18%. The epithelial cells became short and cuboidal, with less secretory blebs and reduced acid phosphatase activity. The luminal sectional area diminished, suggestive of decreased secretory activity. The stromal/epithelial ratio increased, the stroma becoming thicker but less cellular. There was a striking accumulation of collagen fibrils, which was accompanied by an increase in deposits of amorphous granular material adjacent to the basal lamina and in the clefts between smooth muscle cells (SMC). Additionally, the periacinar smooth muscle became loosely packed. Some SMC were atrophic and showed a denser array of the cytoskeleton, whereas other SMC had a highly irregular outline with numerous spine-like projections. The present data indicate that 5 alpha-r inhibition causes epithelial and stromal changes by affecting intra-prostatic hormone levels. These alterations are probably the result of an imbalance of the homeostatic interaction between the epithelium and the underlying stroma.
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PMID:Inhibition of 5-alpha-reductase activity induces stromal remodeling and smooth muscle de-differentiation in adult gerbil ventral prostate. 1527 Jul 76

Apart from reducing systemic lipid levels, statins may improve the clinical course of atherosclerosis by exerting favourable pleiotropic effects on the vessel wall. We studied the effects of rosuvastatin, a new, potent 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, on vascular remodelling after endothelial injury in the hyperlipidaemic apolipoprotein E-knockout (apoE-/-) mouse. ApoE-/- mice, 22-weeks-old, were injected daily with rosuvastatin at a low (1 mg/kg; n=27) or high dosage (10 mg/kg; n=24), or with vehicle alone (n=26). After treatment for 2 weeks, endothelial injury and thrombosis of the carotid artery was induced with 10% ferric chloride. Treatment was then resumed for a 3-week period. Although statin treatment did not affect the plasma lipid levels of mice, mean times to arterial thrombosis were prolonged in the low-dose and the high-dose group compared to controls (P<0.05 and P<0.01 respectively). Interestingly, rosuvastatin withdrawal 4 days before injury completely reversed the antithrombotic effects of the drug. In follow-up studies 3 weeks after injury, deposition of fibrin in the vessel wall was significantly reduced in the rosuvastatin-treated animals. There was an increase in the content of alpha-actin-positive smooth muscle cells (P=0.008) and collagen fibers (P<0.001), and a concomitant decrease in the number of oxLDL-containing macrophages (P<0.001). Overall, the neointimal area and the severity of luminal stenosis were significantly reduced in statin-treated mice. Thus, rosuvastatin attenuates arterial thrombosis and neointima formation, and it may stabilise vascular lesions developing after endothelial injury in mice. These effects are independent of systemic lipid lowering.
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PMID:Rosuvastatin exerts favourable effects on thrombosis and neointimal growth in a mouse model of endothelial injury. 1563 May 5

Simvastatin is best known for its antilipidemic action and use in cardiovascular disease due to its inhibition of 3-hydroxy-3-methylglutaryl CoenzymeA (HMG CoA) reductase, a key enzyme in the cholesterol synthesis pathway. Inhibition of biological precursors in this pathway also enables pleiotrophic immunomodulatory and anti-inflammatory capabilities, including modulation of growth factor expression. Connective tissue growth factor (CTGF) and persistent myofibroblast formation are major determinants of the aggressive fibrotic disease, idiopathic pulmonary fibrosis (IPF). In this study we used human lung fibroblasts derived from healthy and IPF lungs to examine Simvastatin effects on CTGF gene and protein expression, analyzed by RT-PCR and ELISA, respectively. Simvastatin significantly inhibited (P < 0.05) CTGF gene and protein expression, overriding the induction by transforming growth factor-beta1, a known potent inducer of CTGF. Such Simvastatin suppressor action on growth factor interaction was reflected functionally on recognized phenotypes of fibrosis. alpha-smooth muscle actin expression was downregulated and collagen gel contraction reduced by 4.94- and 7.58-fold in IMR90 and HIPF lung fibroblasts, respectively, when preconditioned with 10 microM Simvastatin compared with transforming growth factor-beta1 treatment alone after 24 h. Our data suggest that Simvastatin can modify critical determinants of the profibrogenic machinery responsible for the aggressive clinical profile of IPF, and potentially prevents adverse lung parenchymal remodeling associated with persistent myofibroblast formation.
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PMID:Simvastatin inhibits growth factor expression and modulates profibrogenic markers in lung fibroblasts. 1567 72

alpha-Tocopherol modulates two major signal transduction pathways centered on protein kinase C and phosphatidylinositol 3-kinase. Changes in the activity of these key kinases are associated with changes in cell proliferation, platelet aggregation, and NADPH-oxidase activation. Several genes are also regulated by tocopherols partly because of the effects of tocopherol on these two kinases, but also independently of them. These genes can be divided in five groups: Group 1. Genes that are involved in the uptake and degradation of tocopherols: alpha-tocopherol transfer protein, cytochrome P450 (CYP3A), gamma-glutamyl-cysteine synthetase heavy subunit, and glutathione-S-transferase. Group 2. Genes that are implicated with lipid uptake and atherosclerosis: CD36, SR-BI, and SR-AI/II. Group 3. Genes that are involved in the modulation of extracellular proteins: tropomyosin, collagen-alpha-1, MMP-1, MMP-19, and connective tissue growth factor. Group 4. Genes that are connected to adhesion and inflammation: E-selectin, ICAM-1 integrins, glycoprotein IIb, IL-2, IL-4, IL-1b, and transforming growth factor-beta (TGF-beta). Group 5. Genes implicated in cell signaling and cell cycle regulation: PPAR-gamma, cyclin D1, cyclin E, Bcl2-L1, p27, CD95 (APO-1/Fas ligand), and 5a-steroid reductase type 1. The transcription of p27, Bcl2, alpha-tocopherol transfer protein, cytochrome P450 (CYP3A), gamma-glutamyl-cysteine sythetase heavy subunit, tropomyosin, IL-2, and CTGF appears to be upregulated by one or more tocopherols. All the other listed genes are downregulated. Gene regulation by tocopherols has been associated with protein kinase C because of its deactivation by alpha-tocopherol and its contribution in the regulation of a number of transcription factors (NF-kappaB, AP1). A direct participation of the pregnane X receptor (PXR) / retinoid X receptor (RXR) has been also shown. The antioxidant-responsive element (ARE) and the TGF-beta-responsive element (TGF-beta-RE) appear in some cases to be implicated as well.
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PMID:Vitamin E mediates cell signaling and regulation of gene expression. 1575 36

The premise that a dietary dipeptide approach will improve the understanding of amino acid utilization in the fastest-growing vertebrate, the teleost fish, was tested by examining the muscle free amino acid (FAA) pool and enzyme activities, in concert with growth response, when dietary amino acids were provided in free, dipeptide or protein molecular forms. We present the first evidence in fish that, in response to a synthetic dipeptide diet, muscle FAA varies as a result of both growth rate and amino acid availability of specific peptides. We demonstrate significantly diminished muscle indispensable FAA (3-10-fold) in rainbow trout alevins fed a dipeptide-based diet compared with a protein-based diet. The dipeptide-based diet did not contain proline, resulting in 10-27-fold less muscle free proline and hydroxyproline in alevins. The response of alevins fed FAA-based or peptide-based diets can be indicative of collagen turnover (Hyp/Pro ratio) and showed significant differences between dietary treatments. Pyrroline-5-carboxylate (P5C) reductase activity was detected, suggesting that P5C may ameliorate proline deficiency, but synthesis from glutamate could not maintain free proline levels in muscle. This finding will provide an impetus to test whether proline is conditionally indispensable in young fish, as in mammals and birds. This study shows that amino acids given entirely as dipeptides can sustain fish growth, result in muscle FAA and enzyme responses in line with dietary levels and identify growth-limiting amino acids. The understanding of these factors necessitates a diet formulation that will improve the accuracy of determining amino acid requirements in the early life stages of vertebrates.
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PMID:A concept of dietary dipeptides: a step to resolve the problem of amino acid availability in the early life of vertebrates. 1604 93

Sheep of the semi-feral North Ronaldsay (copper-sensitive) and domesticated Cambridge (copper-tolerant) breeds were compared in respect of pathological changes and protein expression in the liver as a result of excessive dietary copper. Acute mitochondrial damage and hepatic stellate cell (HSC) activation with collagen synthesis occurred in response to moderate copper overload in North Ronaldsay but not in Cambridge sheep. Mitochondrial degradative changes occurred either as ballooning degeneration and rupture with subsequent autophagic degradation or as mitochondrial matrical condensation (pyknosis). In North Ronaldsay sheep prolonged exposure to copper produced mitochondrial hyperplasia and hypertrophy, and nuclear damage with necrosis. Cytosolic isocitrate dehydrogenase (IDH), an enzyme responsive to oxidative stress, was induced in the liver of Cambridge sheep receiving a Cu-supplemented diet but was undetectable in the non-supplemented control sheep. Conversely, IDH was detected at similar levels in both control and copper-supplemented North Ronaldsay sheep, indicating a lower threshold response, and an enhanced susceptibility, to oxidative stress. "Upregulation" of mitochondrial thioredoxin-dependent peroxidase reductase (antioxidant protein-1) in the hepatic cytosol of the North Ronaldsay (but not Cambridge) sheep affirmed the increased susceptibility of the mitochondria to Cu-induced oxidative stress in this breed. Likewise the upregulation of cathepsin-D indicated increased lysosomal activity and HSC activation. The findings may be relevant to copper toxicosis in human infants.
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PMID:The greater susceptibility of North Ronaldsay sheep compared with Cambridge sheep to copper-induced oxidative stress, mitochondrial damage and hepatic stellate cell activation. 1609 32

Therapeutic strategies to prevent atherosclerotic plaque progression and achieve plaque stabilization involve 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA)-reductase inhibitors (statins) and renin-angiotensin system (RAS)-blockade, but studies investigating the potentially additive effects of a combined treatment strategy are rare. We hypothesised that the adjunction of atorvastatin with telmisartan or ramipril might achieve additional effects on experimental atherosclerosis though statin-induced lipid-lowering is lacking. ApoE-/- mice were fed a high-fat diet for 12 weeks and randomized to either placebo (CON), atorvastatin (ATO), ramipril (RAM), telmisartan (TEL) or RAM+ATO and TEL+ATO (N=23 per group). RAS-blockade, but not ATO, reduced systolic blood pressure. None of the treatment regimens lowered systemic cholesterol levels or lipoprotein fractions. RAM, TEL and the combined therapy, but not ATO, significantly reduced aortic lipid deposition. All substances significantly reduced monocyte chemoattracting protein (MCP)-1 concentrations, macrophages and matrixmetalloproteinase (MMP)-9 content and enhanced plaque's content of tissue inhibitor of MMP (TIMP)-1, collagen and fibrous cap thickness, resulting in an overall decrease of advanced plaques (classified as types IV-VI). Additive effects of the adjunction were observed on MMP-9 gelatinolytic activity, interleukin (IL)-6 and IL-10 plasma levels. These results indicate that a combined treatment with RAS-blockade and statins may have additive effects on systemic cardiovascular risk markers even in the absence of lipid-reduction, although additional effects on atherosclerotic plaque progression and stability were not observed in this model.
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PMID:Combined effects of HMG-CoA-reductase inhibition and renin-angiotensin system blockade on experimental atherosclerosis. 1611 75

1. Hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors (statins) reduce mortality after myocardial infarction (MI). Although this may be predominantly due to their known anti-ischaemic actions, these drugs are known to have other beneficial effects. 2. Because pathological deposition of extracellular matrix (ECM) material is a key component of remodelling after MI, we sought to determine whether atorvastatin could inhibit ECM production in vitro. 3. The addition of atorvastatin to rat cardiac fibroblasts stimulated with either transforming growth factor (TGF)-beta1 (TGF-beta1) or angiotensin (Ang) II reduced collagen synthesis in a dose-dependent manner (3.7-fold reduction (95% confidence interval (CI) 1.8-15; P < 0.01) and 5.3-fold reduction (95% CI 1.8-7.7; P < 0.01), respectively, compared with stimulant alone). Similar observations were made in human cardiac fibroblast cell culture. Atorvastatin also dose-dependently reduced TGF-beta1 and AngII-induced increases in alpha(I)-procollagen mRNA (P < 0.01 for both), as well as gene expression of the profibrotic peptide connective tissue growth factor. 4. Atorvastatin appears to directly inhibit collagen production by cardiac fibroblasts. This antifibrotic action may contribute to the antiremodelling effect of statins.
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PMID:In vitro inhibitory effects of atorvastatin on cardiac fibroblasts: implications for ventricular remodelling. 1617 24

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors exert modulatory effects on a number of cell signaling cascades by preventing the synthesis of various isoprenoids derived from the mevalonate pathway. In the present study, we describe a novel pleiotropic effect of HMG-CoA reductase inhibitors, also commonly known as statins, on vascular endothelial growth factor (VEGF)-induced type IV collagen accumulation. VEGF is an angiogenic polypeptide that is also known to play a central role in endothelial cell permeability and differentiation. Recently, VEGF has also been implicated in promoting extracellular matrix (ECM) accumulation, although the precise signaling mechanism that mediates VEGF-induced ECM expansion remains poorly characterized. Elucidation of the mechanisms through which VEGF exerts its effect on ECM is clearly a prerequisite for both understanding the complex biology of this molecule as well as targeting VEGF in several pathological processes. To this end, this study explored the underlying molecular mechanisms mediating VEGF-induced ECM expansion in mesangial cells. Our findings show that VEGF stimulation elicits a robust increase in ECM accumulation that involves RhoA activation, an intact actin cytoskeleton, and beta(1)- integrin activation. Our data also indicate that simvastatin, via mevalonate depletion, reverses VEGF-induced ECM accumulation by preventing RhoA activation.
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PMID:HMG-CoA reductase inhibitor simvastatin mitigates VEGF-induced "inside-out" signaling to extracellular matrix by preventing RhoA activation. 1677 5

Hypercholesterolemia is present in many patients with hypertension and adds a significant component of cardiovascular risk. The 3-hydroxy-3 methyl-glutarylcoenzyme A reductase inhibitors (statins) lower low-density lipoprotein cholesterol but also inhibit many of the structural and functional components of the arteriosclerotic process. Structural effects include reductions in vascular smooth muscle hypertrophy and proliferation, fibrin deposition, and collagen cross-linking. Among the functional effects are improvements in endothelial function, reduction in inflammatory cytokines and reactive oxygen species, and down-regulation of angiotensin II and endothelin receptors. These would be expected to reduce blood pressure in patients with hypertension; 14 studies have shown statin-induced decrease in blood pressure, but 11 studies showed no effect. Many of the studies had no placebo controls, were of short duration, or had small sample sizes, or combinations of these. Despite predictions made on the basis of the vasoprotective actions of statins, the blood-pressure-lowering effects of statins are at best modest.
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PMID:Do statins lower blood pressure? 1756 81


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