Sphingosine-1-phosphate lyase expression in embryonic and adult murine tissues

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid involved in immunity, inflammation, angiogenesis, and cancer. S1P lyase (SPL) is the essential enzyme responsible for S1P degradation. SPL augments apoptosis and is down-regulated in cancer. SPL generates a S1P chemical gradient that promotes lymphocyte trafficking and as such is being targeted to treat autoimmune diseases. Despite growing interest in SPL as a disease marker, antioncogene, and pharmacological target, no comprehensive characterization of SPL expression in mammalian tissues has been reported. We investigated SPL expression in developing and adult mouse tissues by generating and characterizing a β-galactosidase-SPL reporter mouse combined with immunohistochemistry, immunoblotting, and enzyme assays. SPL was expressed in thymic and splenic stromal cells, splenocytes, Peyer's Patches, colonic lymphoid aggregates, circulating T and B lymphocytes, granulocytes, and monocytes, with lowest expression in thymocytes. SPL was highly expressed within the CNS, including arachnoid lining cells, spinal cord, choroid plexus, trigeminal nerve ganglion, and specific neurons of the olfactory bulb, cerebral cortex, midbrain, hindbrain, and cerebellum. Expression was detected in brown adipose tissue, female gonads, adrenal cortex, bladder epithelium, Harderian and preputial glands, and hair follicles. This unique expression pattern suggests SPL has many undiscovered physiological functions apart from its role in immunity.     

VEGF gene mRNA expression in patients with coronary artery disease

To assess the expression of vascular endothelium growth factor (VEGF) mRNA in unstimulated peripheral blood mononuclear cells of patients with and without coronary artery disease (CAD). We also studied whether the functional VEGF -2,578C/A polymorphism may influence the level of VEGF mRNA expression in individuals undergoing coronary angiography because chest pain. We assessed 50 consecutive patients with angiographically confirmed CAD (CAD+). Also, 50 consecutive individuals with normal coronary studies were included in the study for comparison. VEGF mRNA expression was examined using quantitative real-time PCR and genotyping for VEGF -2,578C/A was performed using ARMS-PCR technique. VEGF mRNA expression was significantly decreased in CAD+ patients when compared to CAD- individuals (p = 0.01). The frequency of VEGF -2578 allele C and genotype CC was increased in CAD+ patients. In this regard, homozygosity for the CC genotype was more commonly observed in CAD+ (30 %) than in those without CAD disease (18 %). However, the difference was slightly out of the range of significance (p = 0.1). In addition, a trend for reduction in the expression of VEGF mRNA was observed when patients carrying the VEGF -2,578AA genotype were compared with those VEGF -2,578AC heterozygous or those homozygous for the VEGF -2,578CC genotype. VEGF gene expression is decreased in individuals with CAD+ disease. The VEGF -2,578C/A polymorphism may influences the expression of VEGF.     

A spectrum of novel NPHS1 and NPHS2 gene mutations in pediatric nephrotic syndrome patients from Pakistan

Background

Mutations in the NPHS1 and NPHS2 genes are among the main causes of early-onset and familial steroid resistant nephrotic syndrome respectively. This study was carried out to assess the frequencies of mutations in these two genes in a cohort of Pakistani pediatric NS patients.

Methods

Mutation analysis was carried out by direct sequencing of the NPHS1 and NPHS2 genes in 145 nephrotic syndrome (NS) patients. This cohort included 36 samples of congenital or infantile onset NS cases and 39 samples of familial cases obtained from 30 families.

Results

A total of 7 homozygous (6 novel) mutations were found in the NPHS1 gene and 4 homozygous mutations in the NPHS2 gene. All mutations in the NPHS1 gene were found in the early onset cases. Of these, one patient has a family history of NS. Homozygous p.R229Q mutation in the NPHS2 gene was found in two children with childhood-onset NS.

Conclusions

Our results show a low prevalence of disease causing mutations in the NPHS1 (22% early onset, 5.5% overall) and NPHS2 (3.3% early onset and 3.4% overall) genes in the Pakistani NS children as compared to the European populations. In contrast to the high frequency of the NPHS2 gene mutations reported for familial SRNS in Europe, no mutation was found in the familial Pakistani cases. To our knowledge, this is the first comprehensive screening of the NPHS1 and NPHS2 gene mutations in sporadic and familial NS cases from South Asia.     

Association of the ACE-II genotype with the risk of nephrotic syndrome in Pakistani children

Nephrotic syndrome is a common pediatric glomerular disease associated with heavy proteinuria. Since, the angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism is a putative genetic risk factor for NS, in this study, ACE (I/D) polymorphism was analyzed in 268 NS and 223 control samples by a PCR-based method. The genotypic and allelic frequencies were determined and the association between ACE I/D polymorphism and NS was evaluated. The frequency distribution of the II, ID and DD genotypes was 82 (30.6%), 128 (47.8%) and 58 (21.6%) in the NS patients and 9 (4.0%), 171 (76.7%) and 43 (19.3%) in the control samples respectively. In the Pakistani pediatric NS population, the II genotypic and allelic frequencies were found to be significantly associated with the disease (OR = 6.755; C.I = 3-14.9). No significant association was found between this polymorphism and the response to standard steroid therapy. Thus, in contrast to reports from other parts of the world, the II genotype was found to be significantly associated with NS in the Indian and Malay populations and in the Pakistani population described here. To our knowledge, this is the first report from Pakistan describing the association of the ACE I/D polymorphism with pediatric NS. On the basis of these results, it is suggested that analysis of the ACE (I/D) polymorphism should be performed for the early diagnosis in the high risk NS patients in South Asia.     

Investigation of the role of endosomal Toll-like receptors in murine collagen-induced arthritis reveals a potential role for TLR7 in disease maintenance

The hepatitis C virus (HCV) is both hepatotropic and lymphotropic, responsible for a great number of hepatic and extrahepatic immune-system disorders that comprise the so-called HCV syndrome. HCV-associated rheumatic diseases are characterized by frequent clinico-serological overlap; therefore, correct classification of individual patients is necessary before therapeutic decisions are made. This is particularly difficult to do, however, because of the coexistence of viral infection and complex autoimmune alterations. In this context, mixed cryoglobulinemia syndrome (MCs) represents the prototype of virus-related autoimmune-lymphoproliferative diseases. MCs can be treated at different levels by means of etiological treatment with antivirals (peg-interferon-alpha plus ribavirin) aimed at HCV eradication and/or pathogenetic/symptomatic treatments directed to both immune-system alterations and the vasculitic process (rituximab, cyclophosphamide, steroids, plasmapheresis, and so on). In clinical practice, the therapeutic strategy should be modulated according to severity/activity of the MCs and possibly tailored to each individual patient's conditions. Cryoglobulinemic skin ulcers may represent a therapeutic challenge, which should be managed by means of both local and systemic treatments. HCV-associated arthritis should be differentiated from the simple comorbidity of HCV infection and classical rheumatoid arthritis. It may be treated with low doses of steroids and/or hydroxychloroquine; the use of biologics (rituximab) may be considered in more severe cases. Primary Sj?gren's syndrome is rarely associated with HCV infection, while sicca syndrome and myalgia are frequently detectable in hepatitis C patients, with or without cryoglobulinemic vasculitis. Other autoimmune rheumatic disorders (poly/dermatomyositis, polyarteritis nodosa, osteosclerosis, fibromyalgia, and so on) have been reported as potentially associated with HCV infection in patient populations from different countries, suggesting the role of genetic and/or environmental co-factors. The therapeutic approach to these disorders should be decided according to each individual patient's evaluation, including hepatic, virological, and immunological findings.     

Investigation of the role of endosomal Toll-like receptors in murine collagen-induced arthritis reveals a potential role for TLR7 in disease maintenance

Introduction

Endosomal toll-like receptors (TLRs) have recently emerged as potential contributors to the inflammation observed in human and rodent models of rheumatoid arthritis (RA). This study aims to evaluate the role of endosomal TLRs and in particular TLR7 in the murine collagen induced arthritis (CIA) model.

Methods

CIA was induced by injection of collagen in complete Freund''s adjuvant. To investigate the effect of endosomal TLRs in the CIA model, mianserin was administered daily from the day of disease onset. The specific role of TLR7 was examined by inducing CIA in TLR7-deficient mice. Disease progression was assessed by measuring clinical score, paw swelling, serum anti-collagen antibodies histological parameters, cytokine production and the percentage of T regulatory (T_reg) cells.

Results

Therapeutic administration of mianserin to arthritic animals demonstrated a highly protective effect on paw swelling and joint destruction. TLR7^-/- mice developed a mild arthritis, where the clinical score and paw swelling were significantly compromised in comparison to the control group. The amelioration of arthritis by mianserin and TLR7 deficiency both corresponded with a reduction in IL-17 responses, histological and clinical scores, and paw swelling.

Conclusions

These data highlight the potential role for endosomal TLRs in the maintenance of inflammation in RA and support the concept of a role for TLR7 in experimental arthritis models. This study also illustrates the potential benefit that may be afforded by therapeutically inhibiting the endosomal TLRs in RA.     

Differential inflammatory response to inhaled lipopolysaccharide targeted either to the airways or the alveoli in man

Endotoxin (Lipopolysaccharide, LPS) is a potent inducer of inflammation and there is various LPS contamination in the environment, being a trigger of lung diseases and exacerbation. The objective of this study was to assess the time course of inflammation and the sensitivities of the airways and alveoli to targeted LPS inhalation in order to understand the role of LPS challenge in airway disease.In healthy volunteers without any bronchial hyperresponsiveness we targeted sequentially 1, 5 and 20 μg LPS to the airways and 5 μg LPS to the alveoli using controlled aerosol bolus inhalation. Inflammatory parameters were assessed during a 72 h time period. LPS deposited in the airways induced dose dependent systemic responses with increases of blood neutrophils (peaking at 6 h), Interleukin-6 (peaking at 6 h), body temperature (peaking at 12 h), and CRP (peaking at 24 h). 5 μg LPS targeted to the alveoli caused significantly stronger effects compared to 5 μg airway LPS deposition. Local responses were studied by measuring lung function (FEV(1)) and reactive oxygen production, assessed by hydrogen peroxide (H(2)O(2)) in fractionated exhaled breath condensate (EBC). FEV(1) showed a dose dependent decline, with lowest values at 12 h post LPS challenge. There was a significant 2-fold H(2)O(2) induction in airway-EBC at 2 h post LPS inhalation. Alveolar LPS targeting resulted in the induction of very low levels of EBC-H(2)O(2).Targeting LPS to the alveoli leads to stronger systemic responses compared to airway LPS targeting. Targeted LPS inhalation may provide a novel model of airway inflammation for studying the role of LPS contamination of air pollution in lung diseases, exacerbation and anti-inflammatory drugs.     

Myocardial Chemokine Expression and Intensity of Myocarditis in Chagas Cardiomyopathy Are Controlled by Polymorphisms in CXCL9 and CXCL10

Background

Chronic Chagas cardiomyopathy (CCC), a life-threatening inflammatory dilated cardiomyopathy, affects 30% of the approximately 8 million patients infected by Trypanosoma cruzi. Even though the Th1 T cell-rich myocarditis plays a pivotal role in CCC pathogenesis, little is known about the factors controlling inflammatory cell migration to CCC myocardium.

Methods and Results

Using confocal immunofluorescence and quantitative PCR, we studied cell surface staining and gene expression of the CXCR3, CCR4, CCR5, CCR7, CCR8 receptors and their chemokine ligands in myocardial samples from end-stage CCC patients. CCR5+, CXCR3+, CCR4+, CCL5+ and CXCL9+ mononuclear cells were observed in CCC myocardium. mRNA expression of the chemokines CCL5, CXCL9, CXCL10, CCL17, CCL19 and their receptors was upregulated in CCC myocardium. CXCL9 mRNA expression directly correlated with the intensity of myocarditis, as well as with mRNA expression of CXCR3, CCR4, CCR5, CCR7, CCR8 and their ligands. We also analyzed single-nucleotide polymorphisms for genes encoding the most highly expressed chemokines and receptors in a cohort of Chagas disease patients. CCC patients with ventricular dysfunction displayed reduced genotypic frequencies of CXCL9 rs10336 CC, CXCL10 rs3921 GG, and increased CCR5 rs1799988CC as compared to those without dysfunction. Significantly, myocardial samples from CCC patients carrying the CXCL9/CXCL10 genotypes associated to a lower risk displayed a 2–6 fold reduction in mRNA expression of CXCL9, CXCL10, and other chemokines and receptors, along with reduced intensity of myocarditis, as compared to those with other CXCL9/CXCL10 genotypes.

Conclusions

Results may indicate that genotypes associated to reduced risk in closely linked CXCL9 and CXCL10 genes may modulate local expression of the chemokines themselves, and simultaneously affect myocardial expression of other key chemokines as well as intensity of myocarditis. Taken together our results may suggest that CXCL9 and CXCL10 are master regulators of myocardial inflammatory cell migration, perhaps affecting clinical progression to the life-threatening form of CCC.     

Climate driven egg and hatchling mortality threatens survival of eastern Pacific leatherback turtles

Egg-burying reptiles need relatively stable temperature and humidity in the substrate surrounding their eggs for successful development and hatchling emergence. Here we show that egg and hatchling mortality of leatherback turtles (Dermochelys coriacea) in northwest Costa Rica were affected by climatic variability (precipitation and air temperature) driven by the El Ni?o Southern Oscillation (ENSO). Drier and warmer conditions associated with El Ni?o increased egg and hatchling mortality. The fourth assessment report of the Intergovernmental Panel on Climate Change (IPCC) projects a warming and drying in Central America and other regions of the World, under the SRES A2 development scenario. Using projections from an ensemble of global climate models contributed to the IPCC report, we project that egg and hatchling survival will rapidly decline in the region over the next 100 years by ～50-60%, due to warming and drying in northwestern Costa Rica, threatening the survival of leatherback turtles. Warming and drying trends may also threaten the survival of sea turtles in other areas affected by similar climate changes.