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An inverse relationship exists between kallistatin levels and salt-induced oxidative stress in Dahl-salt sensitive rats. We further investigated the role of kallistatin in inhibiting inflammation and fibrosis through antioxidative stress in Dahl-salt sensitive rats and cultured renal cells. High-salt intake in Dahl-salt sensitive rats induced elevation of thiobarbituric acid reactive substances (an indicator of lipid peroxidation), malondialdehyde levels, reduced nicotinamide-adenine dinucleotide phosphate oxidase activity, and superoxide formation, whereas kallistatin gene delivery significantly reduced these oxidative stress parameters. Kallistatin treatment improved renal function and reduced kidney damage as evidenced by diminished proteinuria and serum urea nitrogen levels, glomerular sclerosis, tubular damage, and protein cast formation. Kallistatin significantly decreased interstitial monocyte-macrophage infiltration and the expression of tumor necrosis factor-alpha, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1. Kallistain also reduced collagen fraction volume and the deposition and expression of collagen types I and III. Renal protection by kallistatin was associated with increased NO levels and endothelial NO synthase expression and decreased p38 mitogen-activated protein kinase, extracellular signal-regulated kinase phosphorylation, and transforming growth factor-beta1 expression. Moreover, kallistatin attenuated tumor necrosis factor-alpha-induced intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression via inhibition of reactive oxygen species formation and p38 mitogen-activated protein kinase and nuclear factor-kappaB activation in cultured proximal tubular cells. Kallistatin inhibited fibronectin and collagen expression by suppressing angiotensin II-induced reactive oxygen species generation and transforming growth factor-beta1 expression in cultured mesangial cells. These combined findings reveal that kallistatin is a novel antioxidant, which prevents salt-induced kidney injury, inflammation, and fibrosis by inhibiting reactive oxygen species-induced proinflammatory cytokine and transforming growth factor-beta1 expression.

We investigated the effect of tissue kallikrein infusion on cardiac protection at acute and sub-acute phases after myocardial infarction (MI). Immediately after MI, rats were infused with purified tissue kallikrein, with or without icatibant (a kinin B2 receptor antagonist). Intramyocardial injection of kallikrein reduced myocardial infarct size and inhibited cardiomyocyte apoptosis at 1 day after MI associated with increased nitric oxide levels, Akt and glycogen synthase kinase-3beta phosphorylation and decreased caspase-3 activation. Kallikrein infusion for 7 days improved cardiac function, normalized left ventricular wall thickness and decreased monocyte/macrophage infiltration in the infarct heart. Kallikrein treatment reduced NADH oxidase expression and activity, superoxide formation and malondialdehyde levels, and reduced MAPK and Ikappa-Balpha phosphorylation, NF-kappaB activation and MCP-1 and VCAM-1 expression. Kallikrein's effects were all blocked by icatibant. These results indicate that kallikrein through kinin B2 receptor activation prevents apoptosis, inflammation and ventricular remodeling by increased nitric oxide formation and suppression of oxidative stress-mediated signaling pathways.

Stroke-induced neurological deficits and mortality are often associated with timing of treatment after the onset of stroke. We showed that local delivery of the human tissue kallikrein gene into rat brain immediately after middle cerebral artery occlusion (MCAO) exerts neuroprotection. In this study, we investigated the effect of systemic delivery of the kallikrein gene 8 hr after MCAO. Expression of recombinant human tissue kallikrein after gene transfer was identified in the ischemic brain region and blood vessels. Intravenous injection of adenovirus encoding the kallikrein gene significantly reduced neurological deficit scores 2 and 7 days after gene transfer. Kallikrein gene transfer also reduced ischemia-reperfusion (I/R)-induced cerebral infarction and promoted the survival and migration of glial cells from penumbra to the ischemic core from 3 to 14 days after gene delivery. Kallikrein reduced I/R-induced apoptosis of neuronal cells and inhibited inflammatory cell accumulation in the ischemic brain. These effects were blocked by the kinin B2 receptor antagonist icatibant. In addition, kallikrein enhanced angiogenesis and promoted neurogenesis after I/R and the stimulatory effect of kinin on neuronal cell proliferation was confirmed in primary cultured neuronal cells. The protective effects of kallikrein, through the kinin B2 receptor, were accompanied by increased cerebral nitric oxide and Bcl-2 levels, Akt phosphorylation, and reduced NAD(P)H oxidase activity, superoxide production, Bax levels, and caspase-3 activity. These results indicate that delayed systemic administration of the kallikrein gene after onset of stroke protects against ischemic brain injury by inhibiting apoptosis and inflammation and by promoting angiogenesis and neurogenesis.

High-fat diet (HFD) can cause obesity, inducing dysregulation of the visceral adipose tissue (VAT). This study aimed to explore potential biological pathways and hub genes involved in obese VAT, and for that, bioinformatic analysis of multiple datasets was performed. The expression profiles (GSE30247, GSE167311 and GSE79434) were downloaded from Gene Expression Omnibus. Overlapping differentially expressed genes (ODEGs) between normal diet and HFD groups in GSE30247 and GSE167311 were selected to run protein–protein interaction network, GO and KEGG analysis. The hub genes in ODEGs were screened by Cytoscape software and further verified in GSE79434 and obese mouse model. A total of 747 ODEGs (599 up-regulated and 148 down-regulated) were screened, and the GO and KEGG analysis showed that the up-regulated ODEGs were significantly enriched in inflammatory response and extracellular matrix receptor interaction pathways. On the other hand, the down-regulated ODEGs were involved in metabolic pathways; however, there were no significant KEGG pathways. Furthermore, six hub genes, Mki67, Rac2, Itgb2, Emr1, Tyrobp and Csf1r were acquired. These pathways and genes were verified in GSE79434 and VAT of obese mice. This study revealed that HFD induced VAT expansion, inflammation and fibrosis, and the hub genes could be used as therapeutic biomarkers in obesity. [ABSTRACT FROM AUTHOR]

Abstract: Background: The impairment of the tissue kallikrein (KLK1)–kinin system (KKS) may result in atheroma development. However, it remains unclear if the KKS correlates with coronary artery disease (CAD). Methods: KLK1, VEGF and hs-CRP plasma levels were measured in 100 patients newly diagnosed with CAD and 33 CAD-free controls. Patients were followed-up for the incidence of major adverse cardiovascular events (MACE) for 8months to 2y. Gene expression of KLK1, CD105 and CD68 was assessed in human coronary endarterectomy specimens. Results: Patients with CAD and acute coronary syndrome (ACS) had significantly elevated KLK1 levels. In addition, the concentration of hs-CRP was increased in ACS patients. A strong positive correlation between plasma KLK1 and the severity of CAD was also demonstrated, suggesting that high KLK1 levels are an independent predictor for CAD. MACE during follow-up significantly correlated with KLK1 levels in the ACS group. Unstable coronary plaques demonstrated markedly increased KLK1 levels, macrophage infiltration and high microvessel density. Additionally, KLK1 staining primarily colocalized with macrophages. Conclusions: In the present study, plasma KLK1 levels were a useful predictor for the presence and extent of CAD. More extensive studies are, however, necessary in order to validate these findings. [Copyright &y& Elsevier]

An inverse relationship exists between kallistatin levels and salt-induced oxidative stress in Dahl-salt sensitive rats. We further investigated the role of kallistatin in inhibiting inflammation and fibrosis through antioxidative stress in Dahl-salt sensitive rats and cultured renal cells. High-salt intake in Dahl-salt sensitive rats induced elevation of thiobarbituric acid reactive substances (an indicator of lipid peroxidation), malondialdehyde levels, reduced nicotinamide-adenine dinucleotide phosphate oxidase activity, and superoxide formation, whereas kallistatin gene delivery significantly reduced these oxidative stress parameters. Kallistatin treatment improved renal function and reduced kidney damage as evidenced by diminished proteinuria and serum urea nitrogen levels, glomerular sclerosis, tubular damage, and protein cast formation. Kallistatin significantly decreased interstitial monocyte-macrophage infiltration and the expression of tumor necrosis factor-alpha, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1. Kallistain also reduced collagen fraction volume and the deposition and expression of collagen types I and III. Renal protection by kallistatin was associated with increased NO levels and endothelial NO synthase expression and decreased p38 mitogen-activated protein kinase, extracellular signal-regulated kinase phosphorylation, and transforming growth factor-beta1 expression. Moreover, kallistatin attenuated tumor necrosis factor-alpha-induced intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression via inhibition of reactive oxygen species formation and p38 mitogen-activated protein kinase and nuclear factor-kappaB activation in cultured proximal tubular cells. Kallistatin inhibited fibronectin and collagen expression by suppressing angiotensin II-induced reactive oxygen species generation and transforming growth factor-beta1 expression in cultured mesangial cells. These combined findings reveal that kallistatin is a novel antioxidant, which prevents salt-induced kidney injury, inflammation, and fibrosis by inhibiting reactive oxygen species-induced proinflammatory cytokine and transforming growth factor-beta1 expression. [ABSTRACT FROM AUTHOR]

The progression of renal disease displays several characteristics, including proteinuria, apoptosis, inflammation, and fibrosis. In this study, we investigated the effect of long-term infusion of kinin in protection against salt-induced renal damage in Dahl salt-sensitive rats. Dahl salt-sensitive rats were fed a high-salt diet for 2 weeks and were then infused with bradykinin (500 ng/h) via subcutaneously implanted minipumps for 3 weeks. Kinin infusion attenuated salt-induced impaired renal function as evidenced by reduced proteinuria, serum creatinine, and blood urea nitrogen levels without apparent effect on blood pressure. Morphological analysis indicated that kinin administration reduced salt-induced glomerular sclerosis, tubular dilatation, luminal protein cast formation, and interlobular arterial thickness. Kinin also significantly lowered collagen I, III, and IV deposition and their mRNA levels. Moreover, kinin reduced interstitial monocyte/macrophage accumulation, as well as tubular cell apoptosis and caspase-3 activity. Protection of renal injury by kinin was associated with increased renal NO levels and reduced nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate oxidase activities and superoxide generation. Suppression of oxidative stress by kinin was accompanied by reduced transforming growth factor-beta1 protein and mRNA levels, as well as decreased phosphorylation of mitogen-activated protein kinases. This is the first study to demonstrate that kinin infusion can directly protect against salt-induced renal injury without blood pressure reduction by inhibiting apoptosis, inflammation, and fibrosis via suppression of oxidative stress, transforming growth factor-beta1 expression, and mitogen-activated protein kinase activation. [ABSTRACT FROM AUTHOR]

Serpina3 is a member of the serine protease inhibitor family and is involved in the inflammatory response. In this study, we investigated the effect of Serpina3c on pancreatic function in hypercholesterolemic mice. To investigate the role of Serpina3c in hyperlipidaemia, Serpina3c knockout mice were bred with Apoe-knockout mice (on a C57BL/6 background) to generate heterozygous Serpina3c-Apoe double knockout (Serpina3c+/−/Apoe+/−) mice and were then bred to obtain homozygotes. C57BL/6, Serpina3c−/−, Apoe−/−, and Apoe−/-Serpina3c−/− mice were fed normal chow, and Apoe−/− and Apoe−/-Serpina3c−/− mice were fed a high-fat diet (HFD). After feeding for 3 months, the mice were monitored for body weight, blood glucose, glucose tolerance, and insulin tolerance test (ITT). ELISA and immunohistochemistry were used to detect insulin levels and glucagon expression. Immunohistochemical staining for macrophages in the pancreas was also performed. Western blot analysis was performed on pancreatic tissues to detect the protein levels of insulin-associated molecules, the metalloproteinase MMP2, the tissue inhibitor TIMP2 and components of the JNK-related pathway. Blood glucose levels, glucose tolerance, and ITT were not significantly different among the groups. Serpina3c knockout resulted in blood lipid abnormalities in mice under HFD conditions. Insulin secretion was decreased in Apoe−/-Serpina3c−/− mice compared with Apoe−/− mice under normal chow conditions. In addition, Apoe−/-Serpina3c−/− mice exhibited increased insulin and glucagon secretion and expression after three months of HFD feeding, but insulin secretion was decreased in Apoe−/-Serpina3c−/− mice compared with Apoe−/− mice after the fifth month of HFD feeding. Serpina3c knockout increased MMP2 protein levels, whereas TIMP2 levels in the pancreas were decreased. Furthermore, Serpina3c knockout significantly upregulated the number of macrophages in the pancreas under HFD conditions. The JNK/AKT/FOXO1/PDX-1 axis was found to be involved in Serpina3c-regulated insulin secretion. These novel findings show that Serpina3c could play a protective role in insulin secretion partly through the JNK-related pathway under HFD conditions. • Serpina3c promotes insulin secretion and protects islet function in a high-fat environment. • Serpina3c mainly acts through JNK-related pathways. • Serpina3c knockout increases the inflammatory response in pancreas. [ABSTRACT FROM AUTHOR]