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All-inorganic perovskite quantum dots (PQDs) have attracted tremendous attention due to their extraordinary optical properties, especially CsPbBr3 QDs with their high stability and photoluminescence efficiency. However, studies investigating the biosensing capabilities of PQDs are still limited. In this work, we designed a visible -light-triggered photoelectrochemical (PEC) sensor based on CsPbBr3 QDs for the first time. The immobilized three-dimensional (3D) ZnO inverse opal photonic crystals (IOPCs) were applied to dihydronicotinamide adenine dinucleotide (NADH) sensing. It was found that the CsPbBr3 QDs, as a photoactive material in a PEC sensor, can expand the photocurrent response of the PEC sensor to the visible region, as well as boost its conductivity. This PEC sensor based on a ZnO/CsPbBr3 electrode demonstrates sensitive detection of NADH in phosphate buffer saline solution and serum, with a good linear range from 0.1 μM to 250 μM and a low detection limit of 0.010 μM. Our strategy offers a new approach to perovskite QD-based PEC sensing, which could be more sensitive and convenient for clinical analysis.

Cysteine proteases play important roles in pathobiology. Here we reveal that cathepsin K (CatK) has a role in ischaemia-induced neovascularization. Femoral artery ligation-induced ischaemia in mice increases CatK expression and activity, and CatK-deficient mice show impaired functional recovery following hindlimb ischaemia. CatK deficiency reduces the levels of cleaved Notch1 (c-Notch1), Hes1 Hey1, Hey2, vascular endothelial growth factor, Flt-1 and phospho-Akt proteins of the ischaemic muscles. In endothelial cells, silencing of CatK mimicked, whereas CatK overexpression enhanced, the levels of c-Notch1 and the expression of Notch downstream signalling molecules, suggesting CatK contributes to Notch1 processing and activates downstream signalling. Moreover, CatK knockdown leads to defective endothelial cell invasion, proliferation and tube formation, and CatK deficiency is associated with decreased circulating endothelial progenitor cells-like CD31(+)/c-Kit(+) cells in mice following hindlimb ischaemia. Transplantation of bone marrow-derived mononuclear cells from CatK(+/+) mice restores the impairment of neovascularization in CatK(-/-) mice. We conclude that CatK may be a potential therapeutic target for ischaemic disease.

Cathepsin K (CatK) is one of the most potent mammalian collagenases. We showed previously the increased expression of CatK in human and animal atherosclerotic lesions. Here, we hypothesized that ablation of CatK mitigates injury-induced neointimal hyperplasia. Male wild-type (CatK(+/+)) and CatK-deficient (CatK(-/-)) mice underwent ligation or a combination of ligation and polyethylene cuff-replacement injuries to the right common carotid artery just proximal to its bifurcation, and they were then processed for morphological and biochemical studies at specific time points. On operative day 28, CatK(-/-) significantly reduced neointimal formation and neovessel formation in both single- and combination-injured arteries compared with the Cat K(+/+) mice. At early time points, CatK(-/-) reduced the lesion macrophage contents and medial smooth muscle cell proliferation, the mRNA levels of monocyte chemoattractant protein-1, toll-like receptor-2, toll-like receptor-4, chemokine ligand-12, and the gelatinolytic activity related to matrix metalloproteinase-2/-9. An aorta-explant assay revealed that smooth muscle cell movement was impaired in the CatK(-/-) mice compared with the CatK(+/+) mice. In addition, the smooth muscle cells and macrophages from CatK(-/-) mice had less invasive ability through a reconstituted basement membrane barrier. This vasculoprotective effect was mimicked by Cat inhibition with trans-epoxysuccinyl-L-leucylamido-{4-guanidino} butane (E64d). These results demonstrate an essential role of CatK in neointimal lesion formation in response to injury, possibly via the reduction of toll-like receptor-2/-4-mediated inflammation and smooth muscle cell proliferation, suggesting a novel therapeutic strategy for the control of endovascular treatment-related restenosis by regulating CatK activity.

Aims: The cystic fibrosis transmembrane conductance regulator (CFTR) is a cyclic AMP regulated chloride channel expressed in the apical plasma membrane of pancreatic duct cells where it plays an important role in fluid secretion. The purpose of this study was to elucidate the role of the CFTR chloride channel on ion and fluid secretion from the guinea-pig pancreas by manipulating the expression of CFTR by RNA interference or by luminal application of a CFTR selective activator, MPB91, in isolated cultured pancreatic ducts., Materials and Methods: Using cDNA isolated from the guinea-pig small intestine, fragments of the CFTR gene were generated by polymerase chain reaction and directly sequenced. Two different RNA duplexes for small interference RNA (siRNA) were designed from the sequence obtained. Fluid secretion from the isolated guinea-pig pancreatic ducts was measured using video-microscopy. The amount of CFTR chloride channel or AQP1 water channel expressed in pancreatic ducts was examined by immunoblotting with antibodies against CFTR or AQP1, respectively., Results: Guinea-pig CFTR consists of 1481 amino acid residues. An additional glutamine residue was found to be inserted between amino acid residues 403 and 404 of human CFTR. Forskolin-stimulated fluid secretion from intact pancreatic ducts was significantly higher in the presence of MPB91 compared to fluid secretion in the absence of MPB91. Both basal and forskolin-stimulated fluid secretion in pancreatic ducts transfected with CFTR specific siRNAs were reduced by ∼50% compared to fluid secretion from ducts transfected with scrambled negative control dsRNAs. The amount of CFTR and AQP1 proteins was reduced to 34% and 45% of control, respectively., Conclusions: The activity of the CFTR chloride channel or the amount of CFTR protein expressed determines the rate of fluid secretion from the isolated guinea-pig pancreatic ducts., (Copyright © 2011 Elsevier Inc. All rights reserved.)

The interactions between the renin-angiotensin system and neovascularization in atherosclerotic plaque development are unclear. We investigated the effects of angiotensin II type 1 receptor antagonism in the pathogenesis of atherosclerosis in apolipoprotein E-deficient (ApoE(-/-)) mice with a special focus on plaque neovascularization. ApoE(-/-) mice fed a high-fat diet were randomly assigned to 1 of 2 groups and administered vehicle or olmesartan for 12 weeks. Quantification of plaque areas at the aortic root and in the thoracic and abdominal aorta revealed that, in all 3 of the regions, olmesartan reduced intimal neovessel density and the mRNA levels of toll-like receptor (TLR) 2 and TLR4. Olmesartan increased the levels of collagen and elastin, reduced the level of macrophages in the aortic root, and reduced the mRNA and the activity of matrix metalloproteinase (MMP) 2 in aortic roots and thoracic aortas. Aortic ring assay revealed that olmesartan-treated ApoE(-/-) mice had a markedly lower angiogenic response than that of untreated ApoE(-/-) mice. Bone marrow-derived endothelial progenitor cell-like c-Kit(+) cells from olmesartan-treated ApoE(-/-) mice showed marked impairment of cellular functions and lower expression of TLR2/TLR4 and MMP-2 compared with those of untreated controls. MMP-2 deficiency reduced intimal neovessel density and atherosclerotic lesion formation. Olmesartan and small-interfering RNA targeting TLR2 reduced the levels of TLR2, and MMP-2 mRNA induced angiotensin II in cultured endothelial cells. Angiotensin II type 1 receptor antagonism appears to inhibit intimal neovascularization in ApoE(-/-) mice, partly by reducing TLR2/TLR4-mediated inflammatory action and MMP activation, thus decreasing atherosclerotic plaque growth and increasing plaque instability.

Objective: The mineralocorticoid receptor has been implicated in the pathogenesis of chronic cardiorenal disease. Statins improve renal remodeling and dysfunction in patients with proteinuric kidney diseases. We aimed to clarify the beneficial effects and mechanisms of action of statins in renal insufficiency., Methods and Results: Dahl salt-sensitive rats fed a high-salt diet were treated from 12 to 20 weeks of age with vehicle, the reduced nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase inhibitor apocynin, the synthetic cathepsin inhibitor E64d, or a low or high dosage of pitavastatin (1 or 3 mg/kg daily). Rats fed a low-salt diet served as controls. Rats on the high-salt diet developed massive proteinuria and glomerulosclerosis; these changes were attenuated by both doses of pitavastatin. The amounts of mRNAs or proteins for mineralocorticoid receptor, angiotensin-converting enzyme, angiotensin II type 1 receptor (AT1R), monocyte chemoattractant protein-1, osteopontin, macrophage infiltration, and NADPH subunits (gp91phox, p22phox, and Rac1) were significantly higher in the failing kidneys of vehicle-treated rats than in the kidneys of control rats. Either dose of pitavastatin significantly attenuated these changes. These effects of pitavastatin were mimicked by those of apocynin and E64d. Pretreatment with pitavastatin and apocynin inhibited mRNA and protein of mineralocorticoid receptor induced by angiotensin II in cultured podocytes., Conclusion: The beneficial effects of pitavastatin are likely attributable, at least in part, to attenuation of the mineralocorticoid receptor-dependent inflammatory mediator, matrix protein, and cathepsin expressions induced by AT1R-mediated NADPH oxidase activation in the kidneys of a salt-induced hypertensive Dahl salt-sensitive rat model.

1. Matrix metalloproteinases (MMP) are associated with the vascular remodelling seen in atherosclerosis and aneurysm. The activation and activity of MMP-2 are regulated by the intrinsic tissue inhibitor of MMP-2 (TIMP-2). The aim of the present study was to examine whether, conversely, MMP-2 can affect the gene and protein expression of TIMP-2. 2. In the present study, we examined the mRNA and protein expression of MMP-2 and TIMP-2 in cultured smooth muscle cells (SMC) from the aortas of MMP-2(+/+) and MMP-2(-/-) mice. We also examined the roles of MMP-2 in SMC cellular events. 3. Western blotting showed that less TIMP-2 protein was present in the conditioned medium of MMP-2(-/-) SMC than in that of MMP-2(+/+) SMC. Real-time reverse transcription polymerase chain reaction analysis showed that MMP-2 deficiency reduced TIMP-2 mRNA expression in SMC. Recombinant MMP-2 enhanced the expression of TIMP-2 protein in cultured SMC from MMP-2(-/-) mice. Furthermore, a siRNA targeting MMP-2 impaired the gene and protein expression of MMP-2 in cultured SMC from MMP-2(+/+) mice. MMP-2 deficiency impaired SMC invasion, but not their proliferation, adhesion or migration. 4. Our findings suggest that MMP-2 is likely to be responsible, at least in part, for regulating TIMP-2 expression and is thus a potential target, in addition to TIMP-2, for therapeutics aimed at preventing cardiovascular remodelling in response to injury., (© 2010 Blackwell Publishing Asia Pty Ltd.)

Background: Exercise stimulates the vascular response in pathological conditions, including ischemia; however, the molecular mechanisms by which exercise improves the impaired hypoxia-induced factor (HIF)-1 alpha-mediated response to hypoxia associated with aging are poorly understood. Here, we report that swimming training (ST) modulates the vascular response to ischemia in aged (24-month-old) mice., Methods and Results: Aged wild-type mice (MMP-2(+/+)) that maintained ST (swimming 1 h/d) from day 1 after surgery were randomly assigned to 4 groups that were treated with either vehicle, LY294002, or deferoxamine for 14 days. Mice that were maintained in a sedentary condition served as controls. ST increased blood flow, capillary density, and levels of p-Akt, HIF-1 alpha, vascular endothelial growth factor, Fit-1, and matrix metalloproteinase-2 (MMP-2) in MMP-2(+/+) mice. ST also increased the numbers of circulating endothelial progenitor cells and their function associated with activation of HIF-1 alpha. All of these effects were diminished by LY294002, an inhibitor of phosphatidylinositol 3-kinase; enhanced by deferoxamine, an HIF-1 alpha stabilizer; and impaired by knockout of MMP-2. Finally, bone marrow transplantation confirmed that ST enhanced endothelial progenitor cell homing to ischemic sites in aged mice., Conclusions: ST can improve neovascularization in response to hypoxia via a phosphatidylinositol 3-kinase-dependent mechanism that is mediated by the HIF-1 alpha/vascular endothelial growth factor/MMP-2 pathway in advanced age.

Although it has been suggested that the renin-angiotensin (RA) system and cathepsins contribute to the development and vulnerability of atherosclerotic plaque, the interaction of the RA system and cathepsins is unclear. Thus, we investigated the effects of an angiotensin II type 1 receptor (AT1) antagonist, olmesartan, on the levels of cathepsins in brachiocephalic atherosclerotic plaque and plaque stabilization in apolipoprotein E (apoE)-deficient mice receiving a high-fat diet. Under a high fat diet, treatment with olmesartan (3 mg/kg per day) maintained collagen and elastin at high levels and attenuated the plaque development and cathepsin S (Cat S) level in the atherosclerotic plaque of apoE-deficient mice. The administration of olmesartan suppressed the accumulation of macrophages in plaque. Immunoreactivities of Cat S and AT1 were observed in macrophages. The amount of Cat S mRNA and the macrophage-mediated collagenolytic and elastolytic activities in cultured macrophages were increased by exposure to angiotensin II (Ang II), and these effects were diminished by olmesartan and the NADPH-oxidase inhibitor apocynin. These results suggested that Cat S derived from macrophages is involved in the mechanisms of atherosclerotic plaque vulnerability, and AT1 blocker maintained the plaque stabilization alongside the suppression of Cat S and macrophage activities., (Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.)