Arginine vasopressin (AVP) is a 9-amino acid peptide that is secreted from the posterior pituitary in response to high plasma osmolality and hypotension. AVP has important roles in circulatory and ...water homoeostasis, which are mediated by oxytocin receptors and by AVP receptor subtypes: V1a (mainly vascular), V1b (pituitary), and V2 (renal). Vaptans are orally and intravenously active nonpeptide vasopressin-receptor antagonists. Recently, subtype-selective nonpeptide vasopressin-receptor agonists have been developed. A selective V1a-receptor antagonist, relcovaptan, has shown initial positive results in the treatment of Raynaud’s disease, dysmenorrhea, and tocolysis. A selective V1b-receptor antagonist, nelivaptan, has beneficial effects in the treatment of psychiatric disorders. Selective V2-receptor antagonists including mozavaptan, lixivaptan, satavaptan, and tolvaptan induce highly hypotonic diuresis without substantially affecting the excretion of electrolytes. A nonselective V1a/V2-receptor antagonist, conivaptan, is used in the treatment for euvolaemic or hypervolemic hyponatremia. Recent basic and clinical studies have shown that AVP-receptor antagonists, especially V2-receptor antagonists, may have therapeutic potential for heart failure. This review presents current information about AVP and its antagonists.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Hypertension is one of the most important cardiovascular risk factors and results in macrophage infiltration of blood vessels. However, how macrophages coordinate inflammatory responses with ...endothelial cells (ECs) remains unclear. In this study, we investigated whether exosomes upregulate the expression of inflammatory factors in ECs under hypertensive conditions. Hypertension was induced in rats by continuous infusion of angiotensin II (Ang II). Exosomes were purified from rat serum by density gradient and ultracentrifugation and used to stimulate human coronary artery ECs (HCAECs). Moreover, the interactions between HCAECs and exosomes from human THP-1-derived macrophages were analyzed. Administration of Ang II enhanced the expression of CD68, a macrophage marker, in rat hearts, suggesting enhanced infiltration of macrophages. In addition, the expression of intracellular adhesion molecule-1 (ICAM1) and plasminogen activator inhibitor-1 (PAI-1), a proinflammatory factor, was increased in hypertensive rat hearts compared with control rats. CD68 protein expression and an increase in the expression of some exosome markers were detected in exosomes from hypertensive rat serum. Moreover, the exosomes upregulated the expression levels of ICAM1 and PAI-1 in HCAECs. The level of miR-17, a negative regulator of ICAM1 expression, was markedly decreased in exosomes from hypertensive rat serum compared with exosomes from control rats. Interestingly, Ang II-stimulated THP-1-derived exosomes also enhanced the expression of ICAM1 and PAI-1 and contained reduced levels of miR-17 compared with exosomes from unstimulated cells. These results suggest that inflammation of ECs under hypertensive conditions is caused, at least in part, by macrophage-derived exosomes.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Androgen deprivation therapy is initially effective for treating patients with advanced prostate cancer; however, the prostate cancer gradually becomes resistant to androgen deprivation therapy, ...which is termed castration‐resistant prostate cancer (CRPC). Androgen receptor splice variant 7 (AR‐V7), one of the causes of CRPC, is correlated with resistance to a new‐generation AR antagonist (enzalutamide) and poor prognosis. Heat shock protein 70 (Hsp70) inhibitor is known to decrease the levels of full‐length AR (AR‐FL), but little is known about its effects against CRPC cells expressing AR‐V7. In this study, we investigated the effect of the Hsp70 inhibitors quercetin and VER155008 in the prostate cancer cell line LNCaP95 that expresses AR‐V7, and explored the mechanism by which Hsp70 regulates AR‐FL and AR‐V7 expression. Quercetin and VER155008 decreased cell proliferation, increased the proportion of apoptotic cells, and decreased the protein levels of AR‐FL and AR‐V7. Furthermore, VER155008 decreased AR‐FL and AR‐V7 mRNA levels. Immunoprecipitation with Hsp70 antibody and mass spectrometry identified Y‐box binding protein 1 (YB‐1) as one of the molecules regulating AR‐FL and AR‐V7 at the transcription level through interaction with Hsp70. VER155008 decreased the phosphorylation of YB‐1 and its localization in the nucleus, indicating that the involvement of Hsp70 in AR regulation might be mediated through the activation and nuclear translocation of YB‐1. Collectively, these results suggest that Hsp70 inhibitors have potential anti‐tumor activity against CRPC by decreasing AR‐FL and AR‐V7 expression through YB‐1 suppression.
In this study, we show that heat shock protein 70 (Hsp70) inhibitors regulate androgen receptors, including the full‐length AR (AR‐FL) and the splice variant AR‐V7 that is a major cause of castration‐resistant prostate cancer (CRPC). Treatment of Hsp70 inhibitors reduced viability, increased apoptosis, and decreased the protein levels of both ARs in LNCaP95 cells, an androgen deprivation‐resistant prostate cancer cell line. We further demonstrate that these effects are mediated by interactions with the transcription factor Y‐box‐binding protein 1.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract Background Remote ischemic conditioning (RIC) by repeated treatment of transient limb ischemia is a clinically applicable method for protecting the heart against injury at the time of ...reperfusion. In this study, we investigated the effects of repeated RIC on cardiac dysfunction after myocardial infarction (MI). Methods and results At 4 weeks after MI, rats were separated into the untreated (UT) group or the RIC-treated group. RIC treatment was performed by 5 cycles of 5 min of bilateral hindlimb ischemia and 5 min of reperfusion once a day for 4 weeks. Despite comparable MI size, left ventricular (LV) ejection fraction (LVEF) was significantly improved in the RIC group compared with the UT group. Furthermore, the LVEF in the RIC group was improved, although not significantly, after treatment. RIC treatment also prevented the deterioration of LV diastolic function. MI-induced LV interstitial fibrosis in the boundary region and oxidant stress were significantly attenuated by RIC treatment. MicroRNA-29a (miR-29a), a key regulator of tissue fibrosis, was highly expressed in the exosomes and the marginal area of the RIC group. Even in the differentiated C2C12-derived exosomes, miR-29a expression was significantly increased under hypoxic condition. As well as miR-29a, insulin-like growth factor 1 receptor (IGF-1R) was highly expressed both in the exosomes and remote non-infarcted myocardium of the RIC group. IGF-1R expression was also increased in the C2C12-derived exosomes under hypoxic conditions. Conclusions Repeated RIC reduces adverse LV remodeling and oxidative stress by MI. Exosome-mediated intercellular communication may contribute to the beneficial effect of RIC treatment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
A growing body of evidence supports the notion that angiotensin II (Ang II), the central product of the renin-angiotensin system, may play a central role not only in the etiology of hypertension but ...also in the pathophysiology of cardiovascular and renal diseases in humans. In this review, we focus on the role of Ang II in cardiovascular and renal diseases at the molecular and cellular levels and discuss up-to-date evidence concerning the in vitro and in vivo actions of Ang II and the pharmacological effects of angiotensin receptor antagonists in comparison with angiotensin-converting enzyme inhibitors. Ang II, via AT(1) receptor, directly causes cellular phenotypic changes and cell growth, regulates the gene expression of various bioactive substances (vasoactive hormones, growth factors, extracellular matrix components, cytokines, etc.), and activates multiple intracellular signaling cascades (mitogen-activated protein kinase cascades, tyrosine kinases, various transcription factors, etc.) in cardiac myocytes and fibroblasts, vascular endothelial and smooth muscle cells, and renal mesangial cells. These actions are supposed to participate in the pathophysiology of cardiac hypertrophy and remodeling, heart failure, vascular thickening, atherosclerosis, and glomerulosclerosis. Furthermore, in vivo recent evidence suggest that the activation of mitogen-activated protein kinases and activator protein-1 by Ang II may play the key role in cardiovascular and renal diseases. However, there are still unresolved questions and controversies on the mechanism of Ang II-mediated cardiovascular and renal diseases.
•We characterize proteomic profiles of adipocyte-derived exosomes.•The protein content of the exosomes under hypoxia is compared with normoxia.•Hypoxia increases the total amount of exosomal proteins ...in adipocytes.•Hypoxic adipocyte-released exosomes have enzymes related to de novo lipogenesis.
Hypoxia occurs within adipose tissues as a result of adipocyte hypertrophy and is associated with adipocyte dysfunction in obesity. Here, we examined whether hypoxia affects the characteristics of adipocyte-derived exosomes. Exosomes are nanovesicles secreted from most cell types as an information carrier between donor and recipient cells, containing a variety of proteins as well as genetic materials. Cultured differentiated 3T3-L1 adipocytes were exposed to hypoxic conditions and the protein content of the exosomes produced from these cells was compared by quantitative proteomic analysis. A total of 231 proteins were identified in the adipocyte-derived exosomes. Some of these proteins showed altered expression levels under hypoxic conditions. These results were confirmed by immunoblot analysis. Especially, hypoxic adipocyte-released exosomes were enriched in enzymes related to de novo lipogenesis such as acetyl-CoA carboxylase, glucose-6-phosphate dehydrogenase, and fatty acid synthase (FASN). The total amount of proteins secreted from exosomes increased by 3–4-fold under hypoxic conditions. Moreover, hypoxia-derived exosomes promoted lipid accumulation in recipient 3T3-L1 adipocytes, compared with those produced under normoxic conditions. FASN levels were increased in undifferentiated 3T3-L1 cells treated with FASN-containing hypoxic adipocytes-derived exosomes. This is a study to characterize the proteomic profiles of adipocyte-derived exosomes. Exosomal proteins derived from hypoxic adipocytes may affect lipogenic activity in neighboring preadipocytes and adipocytes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Although liposome-encapsulated clodronate has been used as a means to deplete macrophages from certain tissues, target leukocyte subtypes within the kidney are not clearly known under normal and ...pathologic conditions. The present study was therefore conducted to examine the effects of liposome clodronate on renal infiltrating cell type following unilateral ureteral obstruction (UUO) and tried to correlate these changes to the mechanisms of early development of renal fibrosis. Renal infiltrating leukocyte subtypes and counts were determined by using multicolor flow cytometric analysis of cell suspensions from obstructed kidneys. UUO for 5 days elicited renal tubular apoptosis and renal fibrosis and showed 4-fold increase in renal leukocytes including monocytes/macrophages, dendritic cells, and T-cells. Repeated administration of liposome clodronate selectively depleted F4/80+ monocytes/macrophages and F4/80+ dendritic cells but not F4/80− dendritic cells or other cell types in both obstructed and non-obstructed kidneys. Tubular apoptosis and renal fibrosis were also significantly attenuated by liposome clodronate. Increased gene expression of TNF-α and TGF-β observed in obstructed kidneys were markedly attenuated by depletion of renal mononuclear phagocytes. These findings suggest that F4/80+ monocytes/macrophages and/or F4/80+ dendritic cells play a pivotal role in the development of obstruction-induced tubular apoptosis and renal fibrosis, possibly through TNF-α and TGF-β dependent mechanisms.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Pirfenidone (5-methyl-1-phenyl-2-(1)H-pyridone) is an effective drug for idiopathic interstitial pneumonia that can prevent and reverse tissue fibrosis in several organs. Therefore, we investigated ...whether pirfenidone has a potential role in preventing angiotensin II (Ang II)-induced cardiac hypertrophy. A cardiac hypertrophic mouse model was created using an Ang II infusion (200 ng kg(-1) min(-1)) in wild-type mice for 2 weeks. Mice were divided into the following three groups: a saline-infused (control) group, an Ang II infusion (vehicle) group and an Ang II infusion+pirfenidone-treated (PFD) group, which received pirfenidone (300 mg kg(-1) per day) by gastric gavage during the Ang II infusion. At 2 weeks, we assessed hemodynamics and cardiac function and investigated tissue fibrosis of the myocardium histologically and genetically. Blood pressure in the vehicle group was significantly increased compared to the control group. Although blood pressure was not different between the vehicle and PFD groups, heart weight was significantly decreased in the PFD group. Echocardiography revealed that left ventricular hypertrophy was significantly increased in the vehicle group vs. the control group. Interestingly, pirfenidone significantly inhibited this effect. Continuous infusion of Ang II increased the perivascular and interstitial tissue fibrosis, and pirfenidone inhibited these fibrotic changes. Pirfenidone also inhibited Ang II-induced hypertrophy. In the vehicle group, the mRNA expressions of atrial natriuretic peptide, brain natriuretic peptide and transforming growth factor-β1 were increased, which was significantly inhibited by pirfenidone. Furthermore, the expression of mineralocorticoid receptors was attenuated by pirfenidone. These results indicate that pirfenidone might be effective as an antifibrotic drug in the treatment of cardiac hypertrophy induced by hypertension.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Dipeptidyl peptidase-4 (DPP-4) inhibitors not only improve impaired glucose tolerance in diabetes, but also have pleiotropic extra-pancreatic effects such as preconditioning effect for myocardial ...ischemia-reperfusion injury. Here, we investigated the anti-remodeling effects of linagliptin, a DPP-4 inhibitor, by use of DPP-4-deficient rats.
After the induction of myocardial infarction (MI), Fischer 344 rats with inactivating mutation of DPP-4 were orally administrated with a DPP-4 inhibitor, linagliptin (5 mg kg−1·day−1), or vehicle in drinking water for 4 weeks. Linagliptin did not affect hemodynamic status, body weight, and infarct size. In echocardiography, linagliptin tended to improve left ventricular (LV) systolic function, and significantly improved LV diastolic function, surprisingly. Interstitial fibrosis in marginal region and macrophage infiltration were significantly lower in the linagliptin group than those in the vehicle group. Fibrosis-related gene expressions, such as collagen I and transforming growth factor-β1 (TGF-β1), and inflammation-related expressions, such as macrophage chemotactic protein 1 and matrix metalloproteinase-2 (MMP-2), were significantly suppressed in marginal area of the linagliptin-treated rats compared with the vehicle rats. The TGF-β1 and MMP-2 protein levels were attenuated by linagliptin in DPP-4-deficient cardiac fibroblasts.
Linagliptin can attenuate MI-induced cardiac remodeling via a DPP-4-independent pathway.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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