The HLA class II Allele DRB1*1501 is over-represented in patients with idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is a progressive and medically refractory lung disease with a grim prognosis. Although the etiology of IPF remains perplexing, abnormal adaptive immune responses are evident in many afflicted patients. We hypothesized that perturbations of human leukocyte antigen (HLA) allele frequencies, which are often seen among patients with immunologic diseases, may also be present in IPF patients.

Methods/Principal Findings

HLA alleles were determined in subpopulations of IPF and normal subjects using molecular typing methods. HLA-DRB1*15 was over-represented in a discovery cohort of 79 Caucasian IPF subjects who had lung transplantations at the University of Pittsburgh (36.7%) compared to normal reference populations. These findings were prospectively replicated in a validation cohort of 196 additional IPF subjects from four other U.S. medical centers that included both ambulatory patients and lung transplantation recipients. High-resolution typing was used to further define specific HLA-DRB1*15 alleles. DRB1*1501 prevalence in IPF subjects was similar among the 143 ambulatory patients and 132 transplant recipients (31.5% and 34.8%, respectively, p = 0.55). The aggregate prevalence of DRB1*1501 in IPF patients was significantly greater than among 285 healthy controls (33.1% vs. 20.0%, respectively, OR 2.0; 95%CI 1.3–2.9, p = 0.0004). IPF patients with DRB1*1501 (n = 91) tended to have decreased diffusing capacities for carbon monoxide (DL_CO) compared to the 184 disease subjects who lacked this allele (37.8±1.7% vs. 42.8±1.4%, p = 0.036).

Conclusions/Significance

DRB1*1501 is more prevalent among IPF patients than normal subjects, and may be associated with greater impairment of gas exchange. These data are novel evidence that immunogenetic processes can play a role in the susceptibility to and/or manifestations of IPF. Findings here of a disease association at the HLA-DR locus have broad pathogenic implications, illustrate a specific chromosomal area for incremental, targeted genomic study, and may identify a distinct clinical phenotype among patients with this enigmatic, morbid lung disease.     

Deletion of insulin-degrading enzyme elicits antipodal, age-dependent effects on glucose and insulin tolerance

Background

Insulin-degrading enzyme (IDE) is widely recognized as the principal protease responsible for the clearance and inactivation of insulin, but its role in glycemic control in vivo is poorly understood. We present here the first longitudinal characterization, to our knowledge, of glucose regulation in mice with pancellular deletion of the IDE gene (IDE-KO mice).

Methodology

IDE-KO mice and wild-type (WT) littermates were characterized at 2, 4, and 6 months of age in terms of body weight, basal glucose and insulin levels, and insulin and glucose tolerance. Consistent with a functional role for IDE in insulin clearance, fasting serum insulin levels in IDE-KO mice were found to be ∼3-fold higher than those in wild-type (WT) controls at all ages examined. In agreement with previous observations, 6-mo-old IDE-KO mice exhibited a severe diabetic phenotype characterized by increased body weight and pronounced glucose and insulin intolerance. In marked contrast, 2-mo-old IDE-KO mice exhibited multiple signs of improved glycemic control, including lower fasting glucose levels, lower body mass, and modestly enhanced insulin and glucose tolerance relative to WT controls. Biochemically, the emergence of the diabetic phenotype in IDE-KO mice correlated with age-dependent reductions in insulin receptor (IR) levels in muscle, adipose, and liver tissue. Primary adipocytes harvested from 6-mo-old IDE-KO mice also showed functional impairments in insulin-stimulated glucose uptake.

Conclusions

Our results indicate that the diabetic phenotype in IDE-KO mice is not a primary consequence of IDE deficiency, but is instead an emergent compensatory response to chronic hyperinsulinemia resulting from complete deletion of IDE in all tissues throughout life. Significantly, our findings provide new evidence to support the idea that partial and/or transient inhibition of IDE may constitute a valid approach to the treatment of diabetes.     

Large scale association analysis identifies three susceptibility loci for coronary artery disease

Genome wide association studies (GWAS) and their replications that have associated DNA variants with myocardial infarction (MI) and/or coronary artery disease (CAD) are predominantly based on populations of European or Eastern Asian descent. Replication of the most significantly associated polymorphisms in multiple populations with distinctive genetic backgrounds and lifestyles is crucial to the understanding of the pathophysiology of a multifactorial disease like CAD. We have used our Lebanese cohort to perform a replication study of nine previously identified CAD/MI susceptibility loci (LTA, CDKN2A-CDKN2B, CELSR2-PSRC1-SORT1, CXCL12, MTHFD1L, WDR12, PCSK9, SH2B3, and SLC22A3), and 88 genes in related phenotypes. The study was conducted on 2,002 patients with detailed demographic, clinical characteristics, and cardiac catheterization results. One marker, rs6922269, in MTHFD1L was significantly protective against MI (OR=0.68, p=0.0035), while the variant rs4977574 in CDKN2A-CDKN2B was significantly associated with MI (OR=1.33, p=0.0086). Associations were detected after adjustment for family history of CAD, gender, hypertension, hyperlipidemia, diabetes, and smoking. The parallel study of 88 previously published genes in related phenotypes encompassed 20,225 markers, three quarters of which with imputed genotypes The study was based on our genome-wide genotype data set, with imputation across the whole genome to HapMap II release 22 using HapMap CEU population as a reference. Analysis was conducted on both the genotyped and imputed variants in the 88 regions covering selected genes. This approach replicated HNRNPA3P1-CXCL12 association with CAD and identified new significant associations of CDKAL1, ST6GAL1, and PTPRD with CAD. Our study provides evidence for the importance of the multifactorial aspect of CAD/MI and describes genes predisposing to their etiology.     

Knowledge of Mange among Masai Pastoralists in Kenya

Background

Pastoralists in low-income countries usually live in close proximity to their animals and thus represent an important repository of information about livestock disease. Since wild and domestic animals often mix freely whilst grazing, pastoralists are also able to observe first-hand the diseases that are present in wildlife and as such are key informants in disease outbreaks in sylvatic animals. We report here the findings of the first study of the knowledge and role of Masai pastoralists in mange in wildlife and livestock in Masai Mara, Kenya.

Methodology/Principal Findings

In this paper we describe the knowledge of mange accrued by 56 Masai pastoralists in Kenya and how they respond to it in both wildlife and livestock. In total, 52 (93%) pastoralists had a clear idea of the clinical appearance of mange, 13 (23%) understood its aetiology and 37 (66%) knew that mites were the causal agent. Thirty-nine (69%) believed that mange cross-infection between domestic and wild animals occurs, while 48 (85%) had observed mange in domestic animals including sheep (77%), goats (57%), dogs (24%) and cattle (14%). The pastoralists had also observed wild animals infected with mange, above all lions (19%), gazelles (14%), cheetahs (12%) and wildebeests (2%). In 68% of cases Masai pastoralists treat mange infection or apply control measures, most commonly via the topical use of acaricides (29%) and/or the reporting of the outbreak to the veterinary authorities (21%). In the period 2007–2011, Kenya Wildlife Service received 24 warnings of 59 wild animals with mange-like lesions from the Masai Mara pastoralist community. The reported species were cheetah, lion, wild dog, Thomson’s gazelle and wildebeest.

Conclusion

Masai pastoralists have good knowledge of mange epidemiology and treatment. Their observations and the treatments they apply are valuable in the control of this disease in both wild and domestic animals.     

Identification of triazolopyridazinones as potent p38α inhibitors

Structure-activity relationship (SAR) investigations of a novel class of triazolopyridazinone p38α mitogen activated protein kinase (MAPK) inhibitors are disclosed. From these studies, increased in vitro potency was observed for 2,6-disubstituted phenyl moieties and N-ethyl triazolopyridazinone cores due to key contacts with Leu108, Ala157 and Val38. Further investigation led to the identification of three compounds, 3g, 3j and 3m that are highly potent inhibitors of LPS-induced MAPKAP kinase 2 (MK2) phosphorylation in 50% human whole blood (hWB), and possess desirable in vivo pharmacokinetic and kinase selectivity profiles.     

Microsatellite-based genotyping of MHC class II DRB1 gene in Iberian and Alpine ibex

In an analysis of a microsatellite locus (OLADRB1) linked to the MHC DRB1 gene of Iberian and Alpine ibex (Capra pyrenaica and Carpa ibex), we detected strong linkage disequilibrium between both loci. The allele length polymorphism at OLADRB1 was unambiguously linked to a particular DRB1 allele. This allowed us to develop a DRB-STR matching method for both ibex species. Validation of the DRB-STR matching method was performed in 160 Iberian ibex from Spain and 98 Alpine ibex from Switzerland and Italy. This simple and relatively inexpensive protocol may find wide applications in a variety of research areas (e.g., mate choice, pathogen-driven selection) and in the biological conservation and management of the Western European ibex populations.     

A New Genetically Encoded Single-Chain Biosensor for Cdc42 Based on FRET,Useful for Live-Cell Imaging

Cdc42 is critical in a myriad of cellular morphogenic processes, requiring precisely regulated activation dynamics to affect specific cellular events. To facilitate direct observations of Cdc42 activation in live cells, we developed and validated a new biosensor of Cdc42 activation. The biosensor is genetically encoded, of single-chain design and capable of correctly localizing to membrane compartments as well as interacting with its upstream regulators including the guanine nucleotide dissociation inhibitor. We characterized this new biosensor in motile mouse embryonic fibroblasts and observed robust activation dynamics at leading edge protrusions, similar to those previously observed for endogenous Cdc42 using the organic dye-based biosensor system. We then extended our validations and observations of Cdc42 activity to macrophages, and show that this new biosensor is able to detect differential activation patterns during phagocytosis and cytokine stimulation. Furthermore, we observe for the first time, a highly transient and localized activation of Cdc42 during podosome formation in macrophages, which was previously hypothesized but never directly visualized.     

Differential susceptibility ofSclerotium cepivorum Berk. to some synthesized visnagin sulfonamide derivates

Twenty-five visnagin sulfonamide derivatives were testedin vitro against sclerotial germination, growth and cellulolytic activity ofSclerotium cepivorum Berk. The effectiveness of the derivatives depends on the concentration and the substituent introduced to the title compounds. The introduction of SO₂Cl₂ to C₉ of visnagin induced high toxicity than introducing SO₂NH₂. Compounds with sulfonyl piperidine or sulfonyl morpholine gave small toxicity only at 30 and 75 μg cm⁻³. Addition of N-aryl ring to visnagin-9-sulfonamide rendered the title compound to be more toxic. The substitution of the N-aryl ring bym-CH₃,m-Cl orp-Cl enhanced the toxicity, while its substitution witho-CH₃,p-CH₃,p-Br,o-OCH₃ orm-OCH₃ caused a drop in the toxicity as compared to compounds with unsubstituted aryl ring. Visnagin sulfonamide derivatives having azole rings were strongly inhibitory for sclerotial germination, growth, sclerotial formation and cellulolytic activity, even when applied at 4 μg cm⁻³. The most toxic one was that having dimethyl isoxazole. The cleavage of γ-pyrone ring led to a decline in the toxicity as compared with the other sulfonamide derivatives. Communicated by J. ŠPAK