MHC class II molecules, cathepsins, and La/SSB proteins in lacrimal acinar cell endomembranes

Phosphodiesterase 9A inhibition improves aging-related increase in pulmonary vascular resistance in mice

As individuals age, there is a gradual decline in cardiopulmonary function, often accompanied by cardiac pump dysfunction leading to increased pulmonary vascular resistance (PVR). Our study aims to investigate the changes in cardiac and pulmonary vascular function associated with aging. Additionally, we aim to explore the impact of phosphodiesterase 9A (PDE9A) inhibition, which has shown promise in treating cardiometabolic diseases, on addressing left ventricle (LV) dysfunction and elevated PVR in aging individuals. Young (3 months old) and aged (32 months old) male C57BL/6 mice were used. Aged mice were treated with the selective PDE9A inhibitor PF04447943 (1 mg/kg/day) through intraperitoneal injections for 10 days. LV function was evaluated using cardiac ultrasound, and PVR was assessed in isolated, ventilated lungs perfused under a constant flow condition. Additionally, changes in PVR were measured in response to perfusion of the endothelium-dependent agonist bradykinin or to nitric oxide (NO) donor sodium nitroprusside (SNP). PDE9A protein expression was measured by Western blots. Our results demonstrate the development of LV diastolic dysfunction and increased PVR in aged mice. The aged mice exhibited diminished decreases in PVR in response to both bradykinin and SNP compared to the young mice. Moreover, the lungs of aged mice showed an increase in PDE9A protein expression. Treatment of aged mice with PF04447943 had no significant effect on LV systolic or diastolic function. However, PF04447943 treatment normalized PVR and SNP-induced responses, though it did not affect the bradykinin response. These data demonstrate a development of LV diastolic dysfunction and increase in PVR in aged mice. We propose that inhibitors of PDE9A could represent a novel therapeutic approach to specifically prevent aging-related pulmonary dysfunction.

Disproportional cardiovascular depressive effects of isoflurane: Serendipitous findings from a comprehensive re-visit in mice

Employment of anesthetics, including isoflurane, though mandatory in animal experiments, is often regarded as a major limitation because results obtained with anesthetics may be different from those obtained under a conscious state. This study re-visits two issues related to the use of isoflurane. First, does isoflurane exert depression equally on all aspects of cardiovascular functions and their regulations? Second, is the circulatory supply of oxygen to brain tissues sufficient under isoflurane anesthesia? We determined in male C57BL/6J mice the temporal effects of 1.5% (vol/vol) isoflurane on blood pressure (BP), heart rate (HR), cardiac performance, baroreflex-mediated sympathetic vasomotor tone, cardiac vagal baroreflex, functional connectivity within the baroreflex neural circuits, carotid or cerebral blood flow, cortical tissue oxygen level, respiratory rate and blood gas. Over 150 min after exposure to 1.5% isoflurane, BP and HR were sustained at 71% and 79% of their awake levels amid a trend of progressive increase. Cardiac performance was within physiological ranges. Baroreflex-mediated sympathetic vasomotor tone gradually reversed from an 85% reduction toward the conscious level, alongside a parallel decrease in inhibitory connectivity between nucleus tractus solitarii (NTS) and rostral ventrolateral medulla. A decline in excitatory connectivity between NTS and nucleus ambiguus accompanied the decrease in cardiac vagal baroreflex. There were progressive increases in carotid or cerebral blood flow and tissue oxygen tension in cerebral cortex, alongside gradual hypoventilation, mild respiratory acidosis and hypercapnia. We conclude that, by eliciting disproportional depressive actions on cardiovascular functions and their regulations, which sustain circulatory supply of oxygen to brain tissues, 1.5% isoflurane is sufficient to maintain optimal cardiovascular functions in mice.

Nuclear receptors in podocyte biology and glomerular disease

Nuclear receptors have a broad spectrum of biological functions in normal physiology and in the pathology of various diseases, including glomerular disease. The primary therapies for many glomerular diseases are glucocorticoids, which exert their immunosuppressive and direct podocyte protective effects via the glucocorticoid receptor (GR). As glucocorticoids are associated with important adverse effects and a substantial proportion of patients show resistance to these therapies, the beneficial effects of selective GR modulators are now being explored. Peroxisome proliferator-activated receptor-γ (PPARγ) agonism using thiazolidinediones has potent podocyte cytoprotective and nephroprotective effects. Repurposing of thiazolidinediones or identification of novel PPARγ modulators are potential strategies to treat non-diabetic glomerular disease. Retinoic acid receptor-α is the key mediator of the renal protective effects of retinoic acid, and repair of the endogenous retinoic acid pathway offers another potential therapeutic strategy for glomerular disease. Vitamin D receptor, oestrogen receptor and mineralocorticoid receptor modulators regulate podocyte injury in experimental models. Further studies are needed to better understand the mechanisms of these nuclear receptors, evaluate their synergistic pathways and identify their novel modulators. Here, we focus on the role of nuclear receptors in podocyte biology and non-diabetic glomerular disease.

Pulmonary Manifestations of Primary Sjögren's Syndrome: Underlying Immunological Mechanisms, Clinical Presentation, and Management

Pulmonary involvement in primary Sjögren's syndrome (pSS) is an understudied entity with important clinical implications. Its prevalence has been reported in up to 20% of pSS patients. Pulmonary manifestations of pSS are diverse with involvement of airway and/or lung parenchyma. Histopathology of lung lesions suggests a predominance of submucosal mononuclear cell infiltration consisting predominantly of CD4+ T cells. Current understanding of the pathophysiology of lung disease in pSS suggests a similar process driving the pulmonary process as those in the salivary glands, with epithelial cells playing a critical role in the initiation, maintenance, and symptomatology of the disease. Clinical manifestations of lung involvement in pSS are as varied as the underlying pathology and can be vague and non-specific, thus delaying diagnosis. Management options depend on the underlying pathology but are generally limited due to lack of systematic randomized controlled trials. This review helps summarize our current understanding of lung involvement in pSS.

Stigmasterol accumulation causes cardiac injury and promotes mortality

Cardiovascular disease is expected to remain the leading cause of death worldwide despite the introduction of proprotein convertase subtilisin/kexin type 9 inhibitors that effectively control cholesterol. Identifying residual risk factors for cardiovascular disease remains an important step for preventing and clinically managing the disease. Here we report cardiac injury and increased mortality occurring despite a 50% reduction in plasma cholesterol in a mouse model of phytosterolemia, a disease characterized by elevated levels of dietary plant sterols in the blood. Our studies show accumulation of stigmasterol, one of phytosterol species, leads to left ventricle dysfunction, cardiac interstitial fibrosis and macrophage infiltration without atherosclerosis, and increased mortality. A pharmacological inhibitor of sterol absorption prevents cardiac fibrogenesis. We propose that the pathological mechanism linking clinical sitosterolemia to the cardiovascular outcomes primarily involves phytosterols-induced cardiac fibrosis rather than cholesterol-driven atherosclerosis. Our studies suggest stigmasterol is a potent and independent risk factor for cardiovascular disease.

Effects of intracerebroventricularly injected glucagon-like peptide-2 on ethanol-induced gastric mucosal damage in rats

PURPOSE

The present study aims to investigate the effects of intracerebroventricularly (i.c.v.)-injected glucagon-like peptide-2 (GLP-2) on ethanol-induced gastric mucosal damage and to reveal the mechanisms involved in this effect.

MATERIALS AND METHODS

Rats received absolute ethanol orally via an orogastric tube 30 minutes after GLP-2 (1-200 ng/10 µl; i.c.v.) or saline (10 µl) injections. They were decapitated 1 hour later, their stomachs were removed, and the gastric mucosal damage was scored.

RESULTS

A total of 100 ng GLP-2 inhibited the gastric mucosal damage by 67%. This effect was abolished by the calcitonin gene-related peptide (CGRP) receptor antagonist CGRP-(8-37) (10 µg/kg; s.c.), but was not affected by either the nitric oxide (NO) synthase inhibitor L-NAME (30 mg/kg; s.c.) or the cyclooxygenase inhibitor indomethacin (5 mg/kg; i.p.). The most effective gastroprotective dose of GLP-2 (100 ng/10 µl; i.c.v.), but not the higher doses (150 or 200 ng/10 µl; i.c.v.) prevented the decrease in gastric mucosal blood flow caused by ethanol. In conclusion, i.c.v. GLP-2 protects against ethanol-induced gastric mucosal damage and this effect is mediated by CGRP receptor activation and gastric mucosal blood flow, but not by NO or prostaglandins.

Adipose-specific lipin1 overexpression in mice protects against alcohol-induced liver injury

Excessive fatty acid release from the white adipose tissue (WAT) contributes to the development of alcoholic liver disease (ALD). Lipin1 (LPIN1), as a co-regulator of DNA-bound transcription factors and a phosphatidic acid (PA) phosphatase (PAP) enzyme that dephosphorylates PA to form diacylglycerol (DAG), is dramatically reduced by alcohol in the WAT. This study aimed at determining the role of adipose LPIN1 in alcohol-induced lipodystrophy and the development of ALD. Transgenic mice overexpressing LPIN1 in adipose tissue (LPIN1-Tg) and wild type (WT) mice were fed a Lieber-DeCarli alcohol or isocaloric maltose dextrin control liquid diet for 8 weeks. Alcohol feeding to WT mice resulted in significant liver damage, which was significantly alleviated in the LPIN1-Tg mice. Alcohol feeding significantly reduced epididymal WAT (EWAT) mass, inhibited lipogenesis, and increased lipolysis in WT mice, which were attenuated in the LPIN1-Tg mice. LPIN1 overexpression also partially reversed alcohol-reduced plasma leptin levels. In WT mice, alcohol feeding induced hepatic lipid accumulation and down-regulation of beta-oxidation genes, which were dramatically alleviated in the LPIN1-Tg mice. LPIN1 overexpression also significantly attenuated alcohol-induced hepatic ER stress. These results suggest that overexpression of LPIN1 in adipose tissue restores WAT lipid storage function and secretive function to alleviate alcohol-induced liver injury.

The role of GRIP1 and ephrin B3 in blood pressure control and vascular smooth muscle cell contractility

Several erythropoietin-producing hepatocellular receptor B family (EPHB) and their ligands, ephrinBs (EFNBs), are involved in blood pressure regulation in animal models. We selected 528 single nucleotide polymorphisms (SNPs) within the genes of EPHB6, EFNB2, EFNB3 and GRIP1 in the EPH/EFN signalling system to query the International Blood Pressure Consortium dataset. A SNP within the glutamate receptor interacting protein 1 (GRIP1) gene presented a p-value of 0.000389, approaching the critical p-value of 0.000302, for association with diastolic blood pressure of 60,396 individuals. According to echocardiography, we found that Efnb3 gene knockout mice showed enhanced constriction in the carotid arteries. In vitro studies revealed that in mouse vascular smooth muscle cells, siRNA knockdown of GRIP1, which is in the EFNB3 reverse signalling pathway, resulted in increased contractility of these cells. These data suggest that molecules in the EPHB/EFNB signalling pathways, specifically EFNB3 and GRIP1, are involved blood pressure regulation.

Effect of acute alpha adrenergic stimulation on cardiac function

Background. Phenylephrine (PE) is a α-adrenergic agent commonly administered by perfusion and anesthesia. It is important to identify the effect of PE, especially on cardiac function. This study was intended to show the effects of PE on cardiac function in the murine model via pressure-volume loops. Methods. Six C57BL/6J twelve-week-old female mice were studied prior to and following PE administration at 50 μg/kg IV. In vivo pressure-volume loops were recorded at both time points. Results. There was an expected increase in maximum arterial pressure by 30% (p < 0.001) and end-systolic pressure by 34% (p < 0.001). However, there was a decrease in cardiac output by 30% (p = 0.0006), ejection fraction by 36% (p = 0.0003) and stroke volume by 25% (p < 0.004). Conclusions. This study demonstrates that PE has an effect on cardiac function beyond increasing vascular resistance. The data suggest the negative effects of PE on cardiac function may be related to stimulation of cardiac α-adrenergic receptors. Perfusion (2007) 22, 289—292.

All-trans retinoic acid potentiates cisplatin-induced kidney injury in rats: impact of retinoic acid signaling pathway

Cisplatin (cis-diammine dichloroplatinum (II), CDDP) is a widely used drug for treatment of various types of cancers. However, CDDP-induced nephrotoxicity remains the main dose-limiting side effect. Retinoids are a group of vitamin A-related compounds that exert their effects through retinoid receptors activation. In this study, we investigated the effect of CDDP treatment on retinoic acid receptor-α (RAR-α) and retinoid X receptor-α (RXR-α) expression. In addition, we investigated the possible modulatory effects of RAR agonist, all-trans retinoic acid (ATRA), on CDDP-induced nephrotoxicity. Rats were treated with saline, DMSO, CDDP, ATRA, or CDDP/ATRA. Twenty-four hours after the last ATRA injection, rats were killed; blood samples were collected; kidneys were dissected; and biochemical, immunohistochemical, and histological examinations were performed. Our results revealed that CDDP treatment significantly increased serum levels of creatinine and urea, with concomitant decrease in serum albumin. Moreover, reduced glutathione (GSH) content as well as superoxide dismutase (SOD) and catalase (CAT) activities were significantly reduced with concurrent increase in kidney malondialdehyde (MDA) content following CDDP treatment. Furthermore, CDDP markedly upregulated tubular RAR-α, RXR-α, fibrin, and inducible nitric oxide synthase (iNOS) protein expression. Although administration of ATRA to control rats did not produce marked alterations in kidney function parameters, administration of ATRA to CDDP-treated rats significantly exacerbated CDDP-induced nephrotoxicity. In addition, CDDP/ATRA co-treatment significantly increased RAR-α, RXR-α, fibrin, and iNOS protein expression compared to CDDP alone. In conclusion, we report, for the first time, the crucial role of retinoid receptors in CDDP-induced nephrotoxicity. Moreover, our findings indicate that co-administration of ATRA with CDDP, although beneficial on the therapeutic effects, their deleterious effects on the kidney may limit their clinical use.

Common variants of NFE2L2 gene predisposes to acute respiratory distress syndrome in patients with severe sepsis

Introduction

The purpose of this study was to investigate whether common variants across the nuclear factor erythroid 2-like 2 (NFE2L2) gene contribute to the development of the acute respiratory distress syndrome (ARDS) in patients with severe sepsis. NFE2L2 is involved in the response to oxidative stress, and it has been shown to be associated with the development of ARDS in trauma patients.

Methods

We performed a case–control study of 321 patients fulfilling international criteria for severe sepsis and ARDS who were admitted to a Spanish network of post-surgical and critical care units, as well as 871 population-based controls. Six tagging single-nucleotide polymorphisms (SNPs) of NFE2L2 were genotyped, and, after further imputation of additional 34 SNPs, association testing with ARDS susceptibility was conducted using logistic regression analysis.

Results

After multiple testing adjustments, our analysis revealed 10 non-coding SNPs in tight linkage disequilibrium (0.75 ≤ r² ≤ 1) that were associated with ARDS susceptibility as a single association signal. One of those SNPs (rs672961) was previously associated with trauma-induced ARDS and modified the promoter activity of the NFE2L2 gene, showing an odds ratio of 1.93 per T allele (95 % confidence interval, 1.17–3.18; p = 0.0089).

Conclusions

Our findings support the involvement of NFE2L2 gene variants in ARDS susceptibility and reinforce further exploration of the role of oxidant stress response as a risk factor for ARDS in critically ill patients.

Cyclooxygenase 1 mRNA expression is undetectable in Madin Darby Canine Kidney cells

Background

Madin Darby Canine Kidney (MDCK) cells form polarized epithelium in vitro and are routinely used in research fields ranging from protein trafficking to influenza. However, the canine origin of these cells also means that compared to man or mouse, genomic resources are more limited and performance of commercially available antibodies often untested. The synthesis of pro-inflammatory prostaglandins in the kidney is mediated by the constitutively expressed cyclooxygenase 1 and the inducible cyclooxygenase 2 (COX-1 and COX-2, respectively). There are conflicting reports on the expression of COX-1 and COX-2 in MDCK cells and this lingering uncertainty about such important pharmacological targets may affect the interpretation of results obtained from this cell line.

Results

In order to definitively settle the issue of cyclooxygenase expression in MDCK cells, we designed PCR primers based on dog genomic sequences to probe COX-1 and COX-2 mRNA expression in MDCK cells and dog kidney. We report that while COX-1 and COX-2 genes are both expressed in dog kidney, COX-1 expression is undetectable in MDCK cells.

Conclusions

By improving the characterization of cyclooxygenase expression in MDCK cells, this study will contribute to a better understanding of the properties of this cell line and lead to improved experimental designs and data interpretations.

The use of hypotransferrinemic mice in studies of iron biology

The hypotransferrinemic (hpx) mouse is a model of inherited transferrin deficiency that originated several decades ago in the BALB/cJ mouse strain. Also known as the hpx mouse, this line is almost completely devoid of transferrin, an abundant serum iron-binding protein. Two of the most prominent phenotypes of the hpx mouse are severe anemia and tissue iron overload. These phenotypes reflect the essential role of transferrin in iron delivery to bone marrow and regulation of iron homeostasis. Over the years, the hpx mouse has been utilized in studies on the role of transferrin, iron and other metals in a variety of organ systems and biological processes. This review summarizes the lessons learned from these studies and suggests possible areas of future exploration using this versatile yet complex mouse model.

Spontaneously Occurring Formation of Intranuclear and Cytoplasmic Inclusions in Renal Proximal Epithelium Due to Accumulation of d-Amino Acid Oxidase in Wistar Hannover Rats

Intranuclear and cytoplasmic inclusions in the renal proximal tubular epithelium were observed in nontreated male and female Wistar Hannover rats in a 26-week study (32 weeks of age) and a 104-week study (110 weeks of age). The incidence rates were less than 5% in these two studies. In affected animals, the inclusions were observed in more than 60% of proximal tubular epithelium as various sized (approximately 1–8 μm in diameter) round and eosinophilic materials, but not in distal tubules, Henle’s loop, or collecting ducts. Ultrastructurally, inclusions appeared finely granular, homogenous with middle-electron density, and without a limiting membrane. These inclusions were determined to be protein histochemically stained by Azan-Mallory and immunoreactive with an antibody against d-amino acid oxidase (DAO). There was no abnormality in in-life observations or in clinical test values suggestive of renal dysfunction. There were no associated degenerative or inflammatory changes in the kidneys, and no similar inclusions were observed in the other organs. These inclusions are very similar to propiverine hydrochloride (propiverine) and norepinephreine/serotonin reuptake inhibitor–induced inclusions. This is the first report of accumulation of DAO and formation of inclusions occurring spontaneously in rat kidneys. The data are important for toxicological studies using Wistar Hannover rats.

Aerosolized bovine lactoferrin reduces lung injury and fibrosis in mice exposed to hyperoxia

This study investigated the ability of aerosolized bovine lactoferrin (bLF) to protect the lungs from injury induced by chronic hyperoxia. Female CD-1 mice were exposed to hyperoxia (FiO2 = 80 %) for 7 days to induce lung injury and fibrosis. The therapeutic effects of bLF, administered via an aerosol delivery system, on the chronic lung injury induced by this period of hyperoxia were measured by bronchoalveolar lavage, lung histology, cell apoptosis, and inflammatory cytokines in the lung tissues. After exposure to hyperoxia for 7 days, the survival of the mice was significantly decreased to 20 %. The protective effects of bLF against hyperoxia were further confirmed by significant reductions in lung edema, total cell numbers in bronchoalveolar lavage fluid, inflammatory cytokines (IL-1β and IL-6), pulmonary fibrosis, and apoptotic DNA fragmentation. The aerosolized bLF protected the mice from oxygen toxicity and increased the survival fraction to 66.7 % in the hyperoxic model. The results support the use of an aerosol therapy with bLF in intensive care units to reduce oxidative injury in patients with severe hypoxemic respiratory failure or chronic obstructive pulmonary disease.

Potential therapeutic effects of natural heme oxygenase-1 inducers in cardiovascular diseases

SIGNIFICANCE

Many physiological effects of natural antioxidants, their extracts or their major active components, have been reported in recent decades. Most of these compounds are characterized by a phenolic structure, similar to that of α-tocopherol, and present antioxidant properties that have been demonstrated both in vitro and in vivo. Polyphenols may increase the capacity of endogenous antioxidant defenses and modulate the cellular redox state. Such effects may have wide-ranging consequences for cellular growth and differentiation.

CRITICAL ISSUES

The majority of in vitro and in vivo studies conducted so far have attributed the protective effect of bioactive polyphenols to their chemical reactivity toward free radicals and their capacity to prevent the oxidation of important intracellular components. One possible protective molecular mechanism of polyphenols is nuclear factor erythroid 2-related factor (Nrf2) activation, which in turn regulates a number of detoxification enzymes.

RECENT ADVANCES

Among the latter, the heme oxygenase-1 (HO-1) pathway is likely to contribute to the established and powerful antioxidant/anti-inflammatory properties of polyphenols. In this context, it is interesting to note that induction of HO-1 expression by means of natural compounds contributes to prevention of cardiovascular diseases in various experimental models.

FUTURE DIRECTIONS

The focus of this review is on the role of natural HO-1 inducers as a potential therapeutic strategy to protect the cardiovascular system against various stressors in several pathological conditions.

Renal Pathophysiologic Role of Cortical Tubular Inclusion Bodies

Renal tubular inclusion bodies are rarely associated with drug administration. The authors describe the finding of renal cortical tubular intranuclear and intracytoplasmic inclusion bodies associated with the oral administration of a norepinephrine/serotonin reuptake inhibitor (NSRI) test article in Sprague-Dawley (SD) rats. Rats were given an NSRI daily for 4 weeks, and kidney histopathologic, ultrastructural pathology, and immunohistochemical examinations were performed. Round eosinophilic intranuclear inclusion bodies were observed histologically in the tubular epithelial cells of the renal cortex in male and female SD rats given the NSRI compound. No evidence of degeneration or necrosis was noted in the inclusion-containing renal cells. By ultrastructural pathology, inclusion bodies consisted of finely granular, amorphous, and uniformly stained nonmembrane-bound material. By immunohistochemistry, inclusion bodies stained positive for d-amino acid oxidase (DAO) protein. In addition, similar inclusion bodies were noted in the cytoplasmic tubular epithelial compartment by ultrastructural and immunohistochemical examination.  This is the first description of these renal inclusion bodies after an NSRI test article administration in SD rats. Such drug-induced renal inclusion bodies are rat-specific, do not represent an expression of nephrotoxicity, represent altered metabolism of d-amino acids, and are not relevant to human safety risk assessment.

Pentoxifylline and prevention of hyperoxia-induced lung -injury in neonatal rats

INTRODUCTION

Oxygen exposure plays an important role in the pathogenesis of bronchopulmonary dysplasia (BPD). The phosphodiesterase inhibitor pentoxifylline (PTX) has anti-inflammatory and antifibrotic effects in multiple organs. It was hypothesized that PTX would have a protective effect on hyperoxia-induced lung injury (HILI).

METHODS

Newborn Sprague-Dawley rats were exposed to >95% oxygen (O(2)) and injected subcutaneously with normal saline (NS) or PTX (75 mg/kg) twice a day for 9 d. NS-injected, room air-exposed pups were controls. At days 4 and 9, lung tissue was collected to assess edema, antioxidant enzyme (AOE) activities, and vascular endothelial growth factor (VEGF) expression. At day 9, pulmonary macrophage infiltration, vascularization, and alveolarization were also examined.

RESULTS

At day 9, treatment with PTX significantly increased survival from 54% to 88% during hyperoxia. Treatment with PTX significantly decreased lung edema and macrophage infiltration. PTX treatment increased lung AOE activities including those of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX). Furthermore, PTX treatment also increased the gene expression of VEGF189 and VEGF165, increased VEGF protein expression, and improved pulmonary vascularization.

DISCUSSION

These data indicate that the reduced lung edema and inflammation, increased AOE activities, and improved vascularization may be responsible for the improved survival with PTX during hyperoxia. PTX may be a potential therapy in reducing some of the features of BPD in preterm newborns.

Inhibitory effects of rosiglitazone on lipopolysaccharide-induced inflammation in a murine model and HK-2 cells

BACKGROUND

Inflammation may play an important role in the pathogenesis of kidney disease. Agonists of the peroxisome proliferator-activated receptor-γ (PPAR-γ), such as rosiglitazone, have been recently demonstrated to regulate inflammation by modulating the production of inflammatory mediators. The purpose of this study was to examine the effects of rosiglitazone on lipopolysaccharide (LPS)-induced kidney inflammation and to explore the mechanism of its renoprotection.

METHODS

Mice were treated with LPS with or without pretreatment with rosiglitazone. Blood urea nitrogen (BUN), creatinine levels, the urinary albumin-to-creatinine ratio, macrophage infiltration, monocyte chemoattractant protein-1 (MCP-1) expression, PPAR-γ expression, and NF-κB and PPAR-γ activity were investigated. HK-2 cells were maintained under defined in vitro conditions, treated with either rosiglitazone and/or the PPAR-γ antagonist GW9662, and then stimulated with LPS. MCP-1, IL-8, IL-6, NF-κB activity and PPAR-γ expression were investigated.

RESULTS

Compared to the LPS only group, pretreatment with rosiglitazone in vivo significantly attenuated the BUN levels macrophage infiltration, MCP-1 overexpression and NF-κB activity (p < 0.05). Rosiglitazone also restored PPAR-γ expression and protein activity, which were reduced significantly in the LPS only group (p < 0.05). Furthermore, in the LPS-stimulated HK-2 cells, rosiglitazone downregulated MCP-1, IL-8 and IL-6 expression as well as NF-κB activation and increased PPAR-γ expression (p < 0.05). These effects were diminished by GW9662.

CONCLUSION

These results showed that pretreatment with rosiglitazone could attenuate kidney inflammation through the activation of PPAR-γ, suppression of MCP-1 overproduction and NF-κB activation. Rosiglitazone had a protective effect via a PPAR-γ-dependent pathway in LPS-treated HK-2 cells.

Intracoronary administration of cardiac stem cells in mice: a new, improved technique for cell therapy in murine models

A model of intracoronary stem cell delivery that enables transgenesis/gene targeting would be a powerful tool but is still lacking. To address this gap, we compared intracoronary and intramyocardial delivery of lin(-)/c-kit(+)/GFP(+) cardiac stem cells (CSCs) in a murine model of reperfused myocardial infarction (MI). Lin(-)/c-kit(+)/GFP(+) CSCs were successfully expanded from GFP transgenic hearts and cultured with no detectable phenotypic change for up to ten passages. Intracoronary delivery of CSCs 2 days post-MI resulted in significant alleviation of adverse LV remodeling and dysfunction, which was at least equivalent, if not superior, to that achieved with intramyocardial delivery. Compared with intramyocardial injection, intracoronary infusion was associated with a more homogeneous distribution of CSCs in the infarcted region and a greater increase in viable tissue in this region, suggesting greater formation of new cardiomyocytes. Intracoronary CSC delivery resulted in improved function in the infarcted region, as well as in improved global LV systolic and diastolic function, and in decreased LV dilation and LV expansion index; the magnitude of these effects was similar to that observed after intramyocardial injection. We conclude that, in the murine model of reperfused MI, intracoronary CSC infusion is at least as effective as intramyocardial injection in limiting LV remodeling and improving both regional and global LV function. The intracoronary route appears to be superior in terms of uniformity of cell distribution, myocyte regeneration, and amount of viable tissue in the risk region. To our knowledge, this is the first study to report that intracoronary infusion of stem cells in mice is feasible and effective.

Plasma protein levels are markers of pulmonary vascular permeability and degree of lung injury in critically ill patients with or at risk for acute lung injury/acute respiratory distress syndrome

OBJECTIVES

To evaluate the diagnostic value of plasma protein levels for pulmonary vascular permeability and acute respiratory distress syndrome. During acute lung injury and acute respiratory distress syndrome, increased vascular permeability induces protein-rich fluid extravasation. We hypothesized that plasma protein levels predict increased vascular permeability and acute respiratory distress syndrome.

DESIGN

A prospective, observational study.

PATIENTS

Eighty-three consecutive, mechanically ventilated patients with or at risk for acute lung injury/acute respiratory distress syndrome, of whom 18 had sepsis. Patients with increased pulmonary capillary wedge pressures or central venous pressures were excluded.

INTERVENTIONS

Patients were subjected to pulmonary capillary wedge pressure/central venous pressure-guided fluid loading with saline or colloid fluids.

MEASUREMENTS AND MAIN RESULTS

We measured plasma albumin and transferrin levels and determined the Gallium-transferrin pulmonary leak index, the American European Consensus Conference criteria, and the lung injury score. Measurements were performed before and after fluid loading to evaluate effects of fluid loading. Plasma albumin and transferrin levels were approximately 30% lower in acute respiratory distress syndrome than patients with acute lung injury (p < .01) and patients without lung injury (p < .05). Protein levels inversely related to the pulmonary leak index (standardized regression coefficient -0.28, p < .001 for albumin; standardized regression coefficient -0.30, p = .003 for transferrin) and the lung injury score (standardized regression coefficient -0.19, p = .01 for albumin), independently of presence of sepsis, severity of disease, and fluid loading. Albumin and transferrin levels had a high sensitivity (77-93%) and negative predictive value (80-98%) for elevated pulmonary vascular permeability and acute respiratory distress syndrome (American European Consensus Conference criteria and lung injury score). The addition of hypoalbuminemia (<17.5 g/L) and hypotransferrinemia (<0.98 g/L) as criteria to the American European Consensus Conference criteria or the lung injury score increased their predictive values for elevated pulmonary vascular permeability.

CONCLUSIONS

In critically ill patients, decreased plasma albumin and transferrin levels parallel increased pulmonary vascular permeability irrespective of underlying disease and fluid status. While normal levels help to exclude acute respiratory distress syndrome, hypoalbuminemia and hypotransferrinemia increase the diagnostic accuracy of the American European Consensus Conference criteria and lung injury score for elevated pulmonary vascular permeability.

Therapeutic effect of retinoic acid on unilateral ureteral obstruction model

BACKGROUND

Retinoic acids, a group of natural and synthetic vitamin A derivatives, have potent anti-proliferative, anti-inflammatory and anti-fibrotic properties. We investigated the therapeutic effect of all-trans-retinoic acid (ATRA) on unilateral ureteral obstruction (UUO) model mice.

METHODS

First, to evaluate the prophylactic effect, we administered 0.5 mg of ATRA for 3 days before UUO (UUO ATRA). Then, to evaluate the therapeutic effects, we administered 0.5 mg of ATRA 3 days after UUO (Day 3 ATRA). We compared the histological changes and immunostaining of macrophages, α-smooth muscle actin (α-SMA) and collagen I, and mRNA expression of monocyte chemotactic protein-1 (MCP-1), transforming growth factor (TGF)-β(1) and TGF-β R-II by RT-PCR 7 days after UUO.

RESULTS

In the UUO ATRA and Day 3 ATRA groups, we observed a significant improvement in histological and immunological findings, including macrophage infiltration and improved expression of MCP-1, TGF-β(1), α-SMA and collagen I compared with the UUO Day 7 group.

CONCLUSION

ATRA treatment is not only an effective prophylactic strategy, but also a therapeutic strategy for the treatment of progressive renal fibrosis in diseased kidneys.

Glial and neuronal control of brain blood flow

Blood flow in the brain is regulated by neurons and astrocytes. Knowledge of how these cells control blood flow is crucial for understanding how neural computation is powered, for interpreting functional imaging scans of brains, and for developing treatments for neurological disorders. It is now recognized that neurotransmitter-mediated signalling has a key role in regulating cerebral blood flow, that much of this control is mediated by astrocytes, that oxygen modulates blood flow regulation, and that blood flow may be controlled by capillaries as well as by arterioles. These conceptual shifts in our understanding of cerebral blood flow control have important implications for the development of new therapeutic approaches.

The p38 SAPK is recruited to chromatin via its interaction with transcription factors

In mammals, the stress-activated protein kinase (SAPK) p38 coordinates a rapid and complex transcriptional program to adapt to sudden changes in the extracellular environment. Although a number of genes have been reported to be under the control of p38, the basic mechanisms of transcriptional regulation by this SAPK remain uncharacterized. Here we show that in response to osmotic shock, anisomycin- or TNFα-activated p38 SAPK is recruited to stress-induced genes. The MAPKK MKK6 is also found at stress-responsive promoters. The recruitment of RNA polymerase II complex to the target promoters requires p38 activity. Moreover, when tethered to DNA as a LexA fusion protein, p38 activates transcription in a stress-regulated manner. Thus, p38 activity allows for recruitment of RNA polymerase and transcription initiation. p38 directly phosphorylates and interacts with the transcription factor Elk1. p38 activity is necessary for the recruitment of Elk1 to the c-Fos promoter, and knocking down Elk1 by siRNAs compromises both p38 recruitment to the c-Fos promoter and c-Fos transcriptional up-regulation upon osmostress. In addition, p38 recruitment to the osmoinducible gene Cox2 and the TNFα target gene IL8 is mediated by the transcription factors AP1 and NFκB, respectively. Therefore, anchoring of active SAPK to target genes is mediated by transcription factors. The presence of active p38 at open reading frames also suggests the involvement of the SAPK in elongation. Taken together, SAPK recruitment to target genes appears to be a broad mechanism to regulate transcription that has been preserved from yeast to mammals.

Sirt1 activation protects the mouse renal medulla from oxidative injury

Sirtuin 1 (Sirt1) is a NAD+-dependent deacetylase that exerts many of the pleiotropic effects of oxidative metabolism. Due to local hypoxia and hypertonicity, the renal medulla is subject to extreme oxidative stress. Here, we set out to investigate the role of Sirt1 in the kidney. Our initial analysis indicated that it was abundantly expressed in mouse renal medullary interstitial cells in vivo. Knocking down Sirt1 expression in primary mouse renal medullary interstitial cells substantially reduced cellular resistance to oxidative stress, while pharmacologic Sirt1 activation using either resveratrol or SRT2183 improved cell survival in response to oxidative stress. The unilateral ureteral obstruction (UUO) model of kidney injury induced markedly more renal apoptosis and fibrosis in Sirt1+/- mice than in wild-type controls, while pharmacologic Sirt1 activation substantially attenuated apoptosis and fibrosis in wild-type mice. Moreover, Sirt1 deficiency attenuated oxidative stress-induced COX2 expression in cultured mouse renal medullary interstitial cells, and Sirt1+/- mice displayed reduced UUO-induced COX2 expression in vivo. Conversely, Sirt1 activation increased renal medullary interstitial cell COX2 expression both in vitro and in vivo. Furthermore, exogenous PGE2 markedly reduced apoptosis in Sirt1-deficient renal medullary interstitial cells following oxidative stress. Taken together, these results identify Sirt1 as an important protective factor for mouse renal medullary interstitial cells following oxidative stress and suggest that the protective function of Sirt1 is partly attributable to its regulation of COX2 induction. We therefore suggest that Sirt1 provides a potential therapeutic target to minimize renal medullary cell damage following oxidative stress.

Effect of all-trans retinoic acid on renal expressions of matrix metalloproteinase-2, matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in rats with glomerulosclerosis

In kidney injury the accumulation of extracellular matrix (ECM) plays an important role and precedes the development of glomerulosclerosis (GS). There is great interest in agents that may interfere with such accumulation of ECM. Therefore, a rat model of GS was established to investigate the effect of all-trans retinoic acid (ATRA) on the renal expressions of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1). Eighty Wistar rats were randomly divided into four groups: sham operation group (SHO), GS model group without treatment (GS), GS model group treated with benazepril (GB) and GS model group treated with ATRA (GA), n = 20, respectively. The disease was established in the GS rats by uninephrectomy and adriamycin (5 mg/kg) injection through the tail vein. Serum creatinine (Scr), blood urea nitrogen (BUN) and urine protein (Upro) were measured. Renal abnormality was evaluated at the end of 12 weeks. Immunohistochemical analysis was performed on renal tissue to detect the expression of collagen IV (Col-IV), fibronectin (FN), MMP-2, MMP-9 and TIMP-1 protein. MMP-2 and MMP-9 activity was detected by gelatin zymography. Real-time reverse transcription polymerase chain reaction (real-time RT-PCR) was used to detect the expression of MMP-2, MMP-9, and TIMP-1 mRNA. In comparison with group GS, group GA and group GB exhibited levels of BUN and 24 h urinary protein and a glomerulosclerosis index (GSI) that were significantly reduced (P < 0.05); the level of Scr in group GA was reduced too (P < 0.05). ATRA and benazepril also significantly down-regulated Col-IV, FN expression and TIMP-1 expression (protein and mRNA) (P < 0.05). In contrast, the expressions of MMP-2, MMP-9 mRNA and protein, and activity in groups GA and GB were enhanced (P < 0.05). However, there were no significant differences in MMP-2, MMP-9 mRNA and protein expression, or activity, between the ATRA and GB groups (P > 0.05). In conclusion, ATRA may protect renal function and step down the progression of GS by reducing the expression of TIMP-1, enhancing the expression and activity of MMP-2 and MMP-9, and regulating the ratio of MMPs/TIMPs to dynamic balance, so as to reduce the accumulation of ECM.

Ischemia/reperfusion Lung Injury Increases Serum Ferritin and Heme Oxygenase-1 in Rats

Intestinal ischemia/reperfusion (I/R) is one of common causes of acute lung injury (ALI). Early and accurate diagnosis of patients who are like to develop serious acute respiratory distress syndrome (ARDS) would give a therapeutic advantage. Ferritin and heme oxygenase-1 (HO-1) are increased by oxidative stress and are potential candidates as a predictive biomarker of ARDS. However, the mechanisms responsible for the increases of ferritin and HO-1, and their relationship to ALI, are unclear. In order to elucidate the interactions between ferritin and HO-1, we studied the changes in ferritin and HO-1 levels in serum and bronchoalveolar lavage (BAL) fluid after intestinal I/R injury in rats. Leukocyte number and protein contents in BAL fluid were elevated following I/R, and the increases were attenuated by mepacrine pretreatment. Both serum ferritin and HO-1 concentrations were progressively elevated throughout the 3 h observation period. Mepacrine pretreatment attenuated the increase of serum and BAL fluid ferritin concentrations, but did not suppress the increase of serum HO-1. Moreover, BAL fluid HO-1 levels did not change after I/R or after mepacrine pretreated I/R compared with sham rats. Unlike ferritin, HO-1 levels are not exactly matched with the ALI. Therefore, there might be a different mechanism between the changes of ferritin and HO-1 in intestinal I/R-induced ALI model.

Protein Never in Mitosis Gene A Interacting-1 regulates calpain activity and the degradation of cyclooxygenase-2 in endothelial cells

Background

The peptidyl-proline isomerase, Protein Never in Mitosis Gene A Interacting-1 (PIN1), regulates turnover of inducible nitric oxide synthase (iNOS) in murine aortic endothelial cells (MAEC) stimulated with E. coli endotoxin (LPS) and interferon-γ (IFN). Degradation of iNOS was reduced by a calpain inhibitor, suggesting that PIN1 may affect induction of other calpain-sensitive inflammatory proteins, such as cyclooxygenase (COX)-2, in MAEC.

Methods

MAEC, transduced with lentivirus encoding an inactive control short hairpin (sh) RNA or one targeting PIN1 that reduced PIN1 by 85%, were used. Cells were treated with LPS/IFN, calpain inhibitors (carbobenzoxy-valinyl-phenylalaninal (zVF), PD150606), cycloheximide and COX inhibitors to determine the effect of PIN1 depletion on COX-2 and calpain.

Results

LPS or IFN alone did not induce COX-2. However, treatment with 10 μg LPS plus 20 ng IFN per ml induced COX-2 protein 10-fold in Control shRNA MAEC. Induction was significantly greater (47-fold) in PIN1 shRNA cells. COX-2-dependent prostaglandin E2 production increased 3-fold in KD MAEC, but did not increase in Control cells. The additional increase in COX-2 protein due to PIN1 depletion was post-transcriptional, as induction of COX-2 mRNA by LPS/IFN was the same in cells containing or lacking PIN1. Instead, the loss of COX-2 protein, after treatment with cycloheximide to block protein synthesis, was reduced in cells lacking PIN1 in comparison with Control cells, indicating that degradation of the enzyme was reduced. zVF and PD150606 each enhanced the induction of COX-2 by LPS/IFN. zVF also slowed the loss of COX-2 after treatment with cycloheximide, and COX-2 was degraded by exogenous μ-calpain in vitro. In contrast to iNOS, physical interaction between COX-2 and PIN1 was not detected, suggesting that effects of PIN1 on calpain, rather than COX-2 itself, affect COX-2 degradation. While cathepsin activity was unaltered, depletion of PIN1 reduced calpain activity by 55% in comparison with Control shRNA cells.

Conclusion

PIN1 reduced calpain activity and slowed the degradation of COX-2 in MAEC, an effect recapitulated by an inhibitor of calpain. Given the sensitivity of COX-2 and iNOS to calpain, PIN1 may normally limit induction of these and other calpain substrates by maintaining calpain activity in endothelial cells.

How safe is the use of thiazolidinediones in clinical practice?

BACKGROUND

Thiazolidinediones (TZDs) are widely used antidiabetic drugs with proven efficacy regarding mainly surrogate markers of diabetes management. However, efficacy on surrogate markers may not always translate into benefits in clinical outcomes. Thiazolidinediones are usually well tolerated; however, their use may be associated with several adverse effects. The first TZD, troglitazone, was withdrawn from the market owing to serious hepatotoxicity. However, this does not seem to be the case with newer TZDs.

OBJECTIVE

The aim of the present review is to discuss the safety profile of this drug class.

METHODS

We searched PubMed up to July 2008 using relevant keywords.

CONCLUSIONS

Common side effects associated with TZDs include edema, weight gain, macular edema and heart failure. Moreover, they may cause hypoglycemia when combined with other antidiabetic drugs as well as decrease hematocrit and hemoglobin levels. Increased bone fracture risk is another TZD-related side effect. Thiazolidinediones tend to increase serum low density lipoprotein cholesterol levels, with rosiglitazone having a more pronounced effect compared with pioglitazone. Moreover, rosiglitazone increases low density lipoprotein particle concentration in contrast to pioglitazone where a decrease is observed. Rosiglitazone has been associated with an increase in myocardial infarction incidence. On the other hand, pioglitazone may reduce cardiovascular events. Overall, TZDs are valuable drugs for diabetes management but physicians should keep in mind that they are associated with several adverse events, the most prominent of which is heart failure.

Effects of gastric vagotomy on visceral cell proliferation induced by ventromedial hypothalamic lesions: role of vagal hyperactivity

In rats, ventromedial hypothalamic (VMH) lesions induce cell proliferation in the visceral organs (stomach, small intestine, liver, and pancreas) due to hyperactivity of the vagus nerve. To investigate the effects of selective gastric vagotomy on VMH lesion-induced cell proliferation and secretion of gastric acid, we assessed the mitotic index (the number of proliferating cell nuclear antigen (PCNA)-immunopositive cells per 1,000 cells in the gastric mucosal cell layer) and measured the volume of secreted basal gastric acid. Furthermore, to explore whether or not ethanol-induced acute gastric mucosal lesions (AGML) lead to ulcer formation in VMH-lesioned rats, we assessed the ulcer index of both sham-operated and VMH-lesioned rats after administration of ethanol. VMH lesions resulted in an increased mitotic index and thickness of the gastric mucosal cell layer and gave rise to the hypersecretion of gastric acid. Selective gastric vagotomy restored these parameters to normal without affecting cell proliferation in other visceral organs. Ethanol-induced AGML caused ulcers in sham VMH-lesioned rats, whereas VMH-lesioned rats were less likely to exhibit such ulcers. These results suggest that VMH lesion-induced vagally mediated cell proliferation in the visceral organs is associated with hyperfunction in these organs, and VMH lesion-induced resistance to ethanol may be due to thickening of the gastric mucosal cell layer resulting from cell proliferation in the gastric mucosa-this in turn is due to hyperactivity of the vagus nerve.

Lack of the serum and glucocorticoid-inducible kinase SGK1 attenuates the volume retention after treatment with the PPARgamma agonist pioglitazone

PPARgamma-agonists enhance insulin sensitivity and improve glucose utilization in diabetic patients. Adverse effects of PPARgamma-agonists include volume retention and edema formation. Recent observations pointed to the ability of PPARgamma agonists to enhance transcription of the serum and glucocorticoid-inducible kinase SGK1, a kinase that is genomically upregulated by mineralocorticoids and stimulates various renal channels and transporters including the renal epithelial Na+ channel ENaC. SGK1 has been proposed to mediate the volume retention after treatment with PPARgamma agonists. To test this hypothesis, food containing the PPARgamma agonist pioglitazone (0.02%, i.e., approximately 25 mg/kg bw/day) was administered to gene-targeted mice lacking SGK1 (sgk1-/-, n=12) and their wild-type littermates (sgk1+/+), n=12). According to in situ hybridization, quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and immunofluorescence, treatment with pioglitazone significantly increased renal SGK1 mRNA and protein expression in sgk1+/+ mice. The treatment increased body weight significantly in both, sgk1+/+ mice (+2.2+/-0.3 g) and sgk-/- mice (+1.3+/-0.2 g), and decreased hematocrit significantly in sgk1+/+ mice (-6.5+/-1.0%) and sgk1-/- mice (-3.1+/-0.6%). Both effects were significantly (p<0.05) more pronounced in sgk1+/+ mice. According to Evans Blue distribution, pioglitazone increased plasma volume only in sgk1+/+ mice (from 50.9+/-3.9 to 63.7+/-2.5 microl/g bw) but not in sgk-/- mice (from 46.8+/-3.8 to 48.3+/-5.2 microl/g bw). Pioglitazone decreased aldosterone plasma levels and blood pressure and increased leptin plasma levels in both genotypes. We conclude that SGK1 contributes to but does not fully account for the volume retention during treatment with the PPARgamma agonist pioglitazone.

Dysregulation of Renal Cyclooxygenase-2 in Rats with Lithium-induced Nephrogenic Diabetes Insipidus

This study aimed to examine whether the expression of major prostaglandin E₂ (PGE₂) synthesis enzyme, cyclooxygenase-2 (COX-2), is changed in the kidneys of the rats with lithium-induced nephrogenic diabetes insipidus (Li-NDI). Sprague-Dawley rats treated with lithium for 4 weeks were used as the NDI model and expression of renal COX-2 was determined by immunoblotting and immunohistochemistry. In Li-NDI where urine output was markedly increased and urine osmolality was significantly decreased, COX-2 expression in the inner medulla was decreased (28% of control), while it increased 18-fold in the cortex and outer medulla. Consistent with this, labeling intensity of COX-2 in macula densa region was increased, whereas it was decreased in the interstitial cells in the inner medulla, indicating a differential regulation of COX-2 between the cortex and inner medulla in Li-NDI. Accordingly, urinary PGE₂ excretion was significantly increased in Li-NDI. In conclusion, there is a differential regulation of COX-2 between cortex and inner medulla in Li-NDI and urinary PGE₂ excretion is increased in Li-NDI, possibly due to an increased renal production. This may suggest that increased renal production of PGE₂ could play a role in modulating water reabsorption in the renal collecting duct in Li-NDI.

Pyrrolidine dithiocarbamate prevents deleterious effects of remote ischemia/reperfusion injury on healing of colonic anastomoses in rats

BACKGROUND

Pyrrolidine dithiocarbamate (PDTC) is a low-molecular-weight thiol antioxidant and potent inhibitor of nuclear factor-kappaB (NF-kappaB) activation. It has been shown to attenuate local harmful effects of ischemia/reperfusion (I/R) injury in many organs. In recent animal studies, a delaying effect of remote organ I/R injury on the healing of colonic anastomoses has been demonstrated. In this study we investigated whether PDTC prevents harmful systemic effects of superior mesenteric I/R on left colonic anastomosis in rats.

METHODS

Anastomosis of the left colon was performed in 40 rats randomly allocated into the following four groups: (1) Sham-operated group (group I, n = 10)-simultaneously with colonic anastomosis, the superior mesenteric artery and collateral branches divided from the celiac axis and the inferior mesenteric artery were isolated but not occluded. (2) Sham+PDTC group (group II, n = 10)-identical to sham-operated rats except for the administration of PDTC (100 mg/kg IV bolus) 30 minutes prior to commencing the experimental period. (3) I/R group (group III, n = 10)-60 minutes of intestinal I/R by superior mesenteric artery occlusion. (4) PDTC-treated group (group IV, n = 10)-PDTC 100 mg/kg before and after the I/R. On postoperative day 6, all animals were sacrificed, and anastomotic bursting pressures were measured in vivo. Tissue samples were obtained for investigation of anastomotic hydroxyproline (HP) contents, perianastomotic malondialdehyde (MDA) levels, myeloperoxidase activity (MPO), and glutathione (GSH) level.

RESULTS

There was a statistically significant decrease in anastomotic bursting pressure values, tissue HP content and GSH level, along with an increase in MDA level and MPO activity in group III, when compared to groups I, II, and IV (p < 0.05). However, PDTC treatment led to a statistically significant increase in anastomotic bursting pressure values, tissue HP content and GSH level, along with a decrease in MDA level and MPO activity in group IV (p < 0.05).

CONCLUSIONS

This study showed that PDTC treatment significantly prevented the delaying effect of remote organ I/R injury on anastomotic healing in the colon. Further clinical studies are needed to clarify whether PDTC may be a useful therapeutic agent for increasing the safety of the anastomosis during particular operations where remote organ I/R injury occurs.

Refinement of cardiac NMR imaging in awake hamsters: proof of feasibility and characterization of cardiomyopathy

The goal of this study was to demonstrate the feasibility of cardiac NMR imaging in conscious hamsters and its usefulness in evaluating cardiac abnormalities in a small-animal model of cardiomyopathy. Awake hamsters, controls and cardiomyopathic ones (CHF 147), were immobilized in a dedicated holder. Half-Fourier single-shot FSE imaging, with outer-volume suppression and 'black-blood' contrast provided images free from motion artifact with good visualization of cardiac anatomy at any point in the cardiac cycle. Series of double-oblique views were acquired with or without electrocardiograph gating. Image acquisition time was 55 ms, with an in-plane resolution of 470 x 625 microm2. Left ventricular volumes, ejection fraction, and myocardium NMR signal heterogeneity were compared in CHF 147 and control hearts. Left ventricles of CHF 147 hamsters were dilated, as indicated by the increase in end-diastolic cavity volume (299 +/- 79 mm3 compared with the controls (141 +/- 39 mm3; P = 0.0002). Left ventricular ejection fraction was largely reduced (45 +/- 9% vs 86 +/- 4%; P < 0.0001). The NMR signal distribution at an effective echo time of 41 ms was more heterogeneous in the myocardial wall of CHF 147 hamsters than in controls (1.87 +/- 0.37 a.u. vs 0.98 +/- 0.12 a.u., respectively; P = 0.0002). This study is a refinement of animal experimentation, as it demonstrates for the first time that characteristic features of cardiac pathology can be evaluated with ultra-fast NMR imaging in conscious small rodents.

Dysfunction of dysferlin-deficient hearts

Mutations in the gene encoding dysferlin cause limb-girdle muscular dystrophy 2B (LGMD2B), a disorder that is believed to spare the heart. We observed dilated cardiomyopathy in two out of seven LGMD2B patients and cardiac abnormalities in three others. Cardiac biopsies showed that dysferlin was completely absent from the sarcolemma and appeared to be trapped within the cardiomyocytes. SJL/J mice (33-week-old) had diminished end-systolic pressure and reduced dP/dt; however, the hearts were histologically normal. Gene expression profiles of cardiac tissue were obtained and later confirmed by quantitative RT-PCR. Dysferlin-deficient and control mice had different gene expression patterns in terms of cardiomyocyte Z-disc and signal transduction proteins. CapZ, LIM-domain-binding protein 3 (LDB3, MLP), cypher (ZASP), desmin, and the cardiac ankyrin-repeated protein (CARP) were differentially expressed, compared to controls. Mechanical stress induced by the nonselective beta-adrenergic agonist isoproterenol (5 mg/kg body weight) given daily for 10 days resulted in reduced fractional shortening and increased cardiac fibrosis in SJL/J mice as compared to controls. Isoproterenol also caused metalloproteinase-2 upregulation in SJL/J mice. In A/J mice, the effect of isoproterenol injection was even more dramatic and lead to premature death as well as marked sarcolemmal injury as demonstrated by Evans blue dye penetration. Our data suggest that disturbances in dysferlin as well as Z-line proteins and transcription factors particularly under mechanical stress cause cardiomyopathy.

Effects of rosiglitazone on plasma brain natriuretic peptide levels and myocardial performance index in patients with type 2 diabetes mellitus

Thiazolidinediones (TZD) have become a powerful tool for lowering insulin resistance. The problem of cardiovascular adverse events including fluid retention and risk of heart failure should be well known and recognised. We aimed to evaluate the long-term effects of rosiglitazone on cardiac function and fluid dynamics. Forty-six type 2 diabetic patients were randomised to treatment with rosiglitazone or metformin or to a control group. There are no significant differences between the groups in the duration of diabetes, HbA1c, plasma brain natriuretic peptide (BNP) levels, body mass index and myocardial performance indexes (MPIs) before the treatment. After three and six months all these parameters were repeated. Rosiglitazone increased plasma BNP levels and worsened MPIs 3 months after the start of treatment. Also left ventricular end-systolic volume increased and weight gain was observed. But these results were statistically non-significant (all p>0.05). When we continued rosiglitazone treatment to six months the increase in BNP levels became soft and statistically significant improvements were seen in MPIs (p<0.01). Also left ventricular end-systolic volume decreased significantly (p=0.004) and weight gain was stopped. In patients with type 2 diabetes, TZD treatment might have slight adverse effects on ventricular contractility and fluid dynamics at the beginning of the therapy. However, these changes seem to stabilise in the long term.

Sjogrens syndrome as failed local immunohomeostasis: prospects for cell-based therapy

Sjogrens syndrome has been estimated to affect between 0.2% and 2% or more of the population. It is an autoimmune disease with the hallmark histopathology of focal, periductal, and perivascular CD4(+) cell infiltration of the lacrimal and salivary glands. The immunohistopathology is typically associated with severe lacrimal and salivary dysfunctions, which contribute to debilitating ocular surface and oral symptoms. The quality of life of patients with Sjogrens syndrome often is degraded further by serious, multisystemic manifestations, and they are subject to a forty-fold increased risk of developing B cell lymphomas. In normal lacrimal glands, secretory epithelial cells, autoimmune effector lymphocytes, and regulatory lymphocytes can be seen as collaborating to maintain a local immunohomeostasis. The epithelium contributes by secreting immunomodulatory paracrine factors and also by continuously exposing autoantigens, which thereby become available for uptake by professional antigen presenting cells (APCs). Local or systemic perturbations may initiate autoimmune pathophysiology by impairing the replacement of normally-turning-over regulatory cells, by altering epithelial production of immunomodulatory paracrine factors, by inducing intact epithelial cells to begin secreting previously cryptic epitopes (epitopes that previously were not available to bind to major histocompatibility complex (MHC) molecules and so could not be recognized by T cell antigen receptors), and by inducing epithelial cells to begin expressing MHC Class II molecules and presenting formerly cryptic epitopes directly to CD4(+) cells. This process has been modeled ex vivo with mixed cell reactions comprised of isolated epithelial cells and autologous lymphocytes. This development has occurred as studies of anterior chamber-associated immune deviation (ACAID) and other immunoregulatory phenomena have elucidated the origins and functions of several different kinds of regulatory lymphocytes and shown that regulatory lymphocytes can be generated ex vivo. It now is possible to envision strategies for exploiting each possible mode of epithelial autoantigen exposure to produce therapeutic regulatory cells that might be capable of re-establishing normal immunohomeostasis. Consideration of the hypothetical therapies identifies a number of basic questions that warrant investigation.

Pyrrolidine Dithiocarbamate Reduces Lung Injury Caused by Mesenteric Ischemia/Reperfusion in a Rat Model

BACKGROUND

Pyrrolidine dithiocarbamate (PDTC) is a low-molecular thiol antioxidant and potent inhibitor of nuclear factor-kappaB (NF-kappaB) activation. It has been shown to attenuate local harmful effects of ischemia/reperfusion (I/R) injury in many organs. In this study, we aimed to study the effect of PDTC on lung reperfusion injury induced by superior mesenteric occlusion.

METHODS

Male Wistar-albino rats randomized into three groups: (1) sham-operated control group (n = 12), laparotomy without I/R injury; (2) intestinal ischemia/reperfusion (I/R) group (n = 12), 60 min of ischemia by superior mesenteric occlusion followed by 2 h of reperfusion; and (3) I/R+PDTC-treated group (n = 12), 100 mg/kg injection of PDTC intravenously, 30 min after the commencement of reperfusion. Evans blue dye was injected to half of rats in all groups before the induction of I/R. We assessed the degree of pulmonary tissue injury biochemically by measuring malondialdehyde (MDA), glutathione (GSH), and nitric oxide (NO) levels, and histopathologically by establishing pulmonary neutrophil sequestration and acute lung injury scoring. Pulmonary edema was evaluated by Evans blue dye extravasation, as well as lung tissue wet/dry weight ratios.

RESULTS

Pyrrolidine dithiocarbamate treatment significantly reduced the MDA and NO levels, and increased the GSH levels in the lung parenchyma, biochemically (p < 0.05), and atteneuated the pulmonary parenchymal damage, histopathologically (p < 0.05). However, pulmonary neutrophil sequestration was not affected by postischemic treatment with PDTC (p > 0.05). Pyrrolidine dithiocarbamate administration also significantly alleviated the formation of pulmonary edema, as evidenced by the decreased Evans blue dye extravasation and organ wet/dry weight ratios (p < 0.05).

CONCLUSIONS

This study showed that postischemic treatment with PDTC significantly attenuated the lung reperfusion injury. Further clinical studies are needed for better understanding of the specific mechanisms of PDTC protection against I/R-related organ injury and to clarify whether PDTC may be a useful therapeutic agent during particular operations where remote organ I/R injury occurs.

Induction of PPAR gamma mRNA and protein expression by rosiglitazone in chronic cyclosporine nephropathy in the rat

PURPOSE

We recently reported that rosiglitazone (RGTZ), a peroxisome proliferator-activated receptor gamma (PPARgamma) agonist, has a protective effect against cyclosporine (CsA)- induced renal injury. Here we report the effect of RGTZ on peroxisome proliferator-activated receptor gamma (PPARgamma) expression in an experimental model of chronic cyclosporine (CsA) nephropathy.

MATERIALS AND METHODS

Chronic CsA nephropathy was induced in Sprague-Dawley rats by administering CsA (15mg/kg per day) for 28 days, and control rats were treated with vehicle (VH group, olive oil 1mL/kg per day) for 28 days. RGTZ (3mg/kg) was concurrently administered via gavage to the CsA and VH groups. Expression of PPARgamma mRNA and protein was evaluated with RT-PCR, immunohistochemistry, and immunoblotting.

RESULTS

PPARgamma mRNA expression was similar to the level of PPARgamma protein constitutively expressed in the kidneys of the VH treated rats, with expression in the glomerular epithelial, distal tubular cells, and collecting tubular cells. PPARgamma protein expression in CsA-treated rat kidneys was significantly less than in the VH group. However, concomitant administration of RGTZ restored PPARgamma protein expression in the kidneys of the CsA- reated rats.

CONCLUSION

Exogenous administration of RGTZ treatment upregulates PPARgamma expression and that this mechanism may play a role in protecting against CsA-induced renal injury.

[Diagnosis and therapy of sepsis]

A recent survey conducted by the publicly funded Competence Network Sepsis (Sep- Net) reveals that severe sepsis and/or septic shock occurs in 75,000 inhabitants (110 out of 100,000) and sepsis in 79,000 inhabitants (116 out of 100,000) in Germany annually. This illness is responsible for approx. 60,000 deaths and ranges as the third most frequent cause of death after acute myocardial infarction. Direct costs for the intensive care of patients with severe sepsis alone amount to approx. 1.77 billion euros, which means that about 30% of the budget in intensive care is used to treat severe sepsis. However, until now German guidelines for the diagnosis and therapy of severe sepsis did not exist. Therefore, the German Sepsis Society initiated the development of guidelines which are based on international recommendations by the International Sepsis Forum (ISF) and the Surviving Sepsis Campaign (SSC) and take into account the structure and organisation of the German health care system. Priority was given to the following guideline topics: a) diagnosis, b) prevention, c) causative therapy, d) supportive therapy, e) adjunctive therapy. The guidelines development process was carefully planned and strictly adhered to according to the requirements of the Working Group of Scientific Medical Societies (AWMF).

Research in Dry Eye: Report of the Research Subcommittee of the International Dry Eye WorkShop (2007)

Members of the DEWS Research Subcommittee reviewed research into the basic mechanisms underlying dry eye disease. Evidence was evaluated concerning the tear film, lacrimal gland and accessory lacrimal glands, ocular surface epithelia (including cornea and conjunctiva), meibomian glands, lacrimal duct system and the immune system. Consideration was given to both animal and human research data. Results are presented as a series of information matrices, identifying what is known and providing supporting references. An attempt is made to identify areas for further investigation.

Effects of pyrrolidine dithiocarbamate on healing of colonic anastomoses in the cecal ligation and puncture model of intraperitoneal sepsis in rats

INTRODUCTION

Pyrrolidine dithiocarbamate (PDTC) is a low-molecular thiol antioxidant and potent inhibitor of nuclear factor-kappaB (NF-kappaB) activation. In recent animal studies, the delaying effect of intraperitoneal sepsis on healing of colonic anastomoses has been demonstrated. In this study, we aimed to investigate the effects of PDTC on healing of colonic anastomoses in the presence of intraperitoneal sepsis induced by a rodent model of cecal ligation and puncture (CLP).

METHODS

Anastomosis of the left colon was performed on the day following CLP in 30 rats that were divided into three groups: sham-operated control (laparotomy and cecal mobilization, group I, n =10), cecal ligation and puncture (CLP) (group II, n = 10), PDTC-treated group (100 mg/kg IV before construction of the colonic anastomosis) (group III, n = 10). On postoperative day 6, all animals were sacrificed, and anastomotic bursting pressures were measured in vivo. Tissue samples were obtained for further investigation of colonic anastomotic hydroxyproline (HP) contents, perianastomotic myeloperoxidase (MPO) activity, and malondialdehyde (MDA) and glutathione (GSH) levels.

RESULTS

There was a statistically significant increase in the activity of MPO and MDA levels in the CLP group (group II) along with a decrease in GSH levels, colonic anastomotic HP contents, and bursting pressure values when compared to controls (group I). However, PDTC treatment led to a statistically significant increase in the tissue HP contents, GSH levels, and colonic anastomotic bursting pressure values, along with a decrease in MPO activity and MDA levels in group III (p < 0.05).

CONCLUSIONS

This study showed that PDTC treatment significantly prevented the delaying effect of CLP-induced intraperitoneal sepsis on anastomotic healing in the colon. Further clinical studies are needed to clarify whether PDTC may be a useful therapeutic agent to increase the safety of the anastomosis during particular operations where sepsis-induced injury occurs.