Polymorphisms in the TNFA and IL6 Genes Represent Risk Factors for Autoimmune Thyroid Disease

Background

Autoimmune thyroid disease (AITD) comprises diseases including Hashimoto''s thyroiditis and Graves'' disease, both characterized by reactivity to autoantigens causing, respectively, inflammatory destruction and autoimmune stimulation of the thyroid-stimulating hormone receptor. AITD is the most common thyroid disease and the leading form of autoimmune disease in women. Cytokines are key regulators of the immune and inflammatory responses; therefore, genetic variants at cytokine-encoding genes are potential risk factors for AITD.

Methods

Polymorphisms in the IL6-174 G/C (rs1800795), TNFA-308 G/A (rs1800629), IL1B-511 C/T (rs16944), and IFNGR1-56 T/C (rs2234711) genes were assessed in a case-control study comprising 420 Hashimoto''s thyroiditis patients, 111 Graves'' disease patients and 735 unrelated controls from Portugal. Genetic variants were discriminated by real-time PCR using TaqMan SNP genotyping assays.

Results

A significant association was found between the allele A in TNFA-308 G/A and Hashimoto''s thyroiditis, both in the dominant (OR = 1.82, CI = 1.37–2.43, p-value = 4.4×10⁻⁵) and log-additive (OR = 1.64, CI = 1.28–2.10, p-value = 8.2×10⁻⁵) models. The allele C in IL6-174 G/C is also associated with Hashimoto''s thyroiditis, however, only retained significance after multiple testing correction in the log-additive model (OR = 1.28, CI = 1.06–1.54, p-value = 8.9×10⁻³). The group with Graves'' disease also registered a higher frequency of the allele A in TNFA-308 G/A compared with controls both in the dominant (OR = 1.85, CI = 1.19–2.87, p-value = 7.0×10⁻³) and log-additive (OR = 1.69, CI = 1.17–2.44, p-value = 6.6×10⁻³) models. The risk for Hashimoto''s thyroiditis and Graves'' disease increases with the number of risk alleles (OR for two risk alleles is, respectively, 2.27 and 2.59).

Conclusions

This study reports significant associations of genetic variants in TNFA and IL6 with the risk for AITD, highlighting the relevance of polymorphisms in inflammation-related genes in the etiopathogenesis of AITD.     

Role of mitogen-activated protein kinases and tyrosine kinases on IL-1-Induced NF-kappaB activation and iNOS expression in bovine articular chondrocytes.

Nitric oxide (NO), produced by the inducible isoform of the NO synthase (iNOS), plays an important role in the pathophysiology of arthritic diseases. This work aimed at elucidating the role of the mitogen-activated protein kinases (MAPK), p38MAPK and p42/44MAPK, and of protein tyrosine kinases (PTK) on interleukin-1beta (IL-1)-induced iNOS expression in bovine articular chondrocytes. The specific inhibitor of the p38MAPK, SB 203580, effectively inhibited IL-1-induced iNOS mRNA and protein synthesis, as well as NO production, while the specific inhibitor of the p42/44MAPK, PD 98059, had no effect. These responses to IL-1 were also inhibited by treatment of the cells with the tyrosine kinase inhibitors, genistein and tyrphostin B42, which also prevented IL-1-induced NF-kappaB activation. The p38MAPK inhibitor, SB 203580, had no effect on IL-1-induced NF-kappaB activation. Finally, the p42/44MAPK inhibitor, PD 98059, prevented IL-1-induced AP-1 activation in a concentration that did not inhibit iNOS expression. In conclusion, this study shows that (1) PTK are part of the signaling pathway that leads to IL-1-induced NF-kappaB activation and iNOS expression; (2) the p38MAPK cascade is required for IL-1-induced iNOS expression; (3) the p42/44MAPK and AP-1 are not involved in IL-1-induced iNOS expression; and (4) NF-kappaB and the p38MAPK lie on two distinct pathways that seem to be independently required for IL-1-induced iNOS expression. Hence, inhibition of any of these two signaling cascades is sufficient to prevent iNOS expression and the subsequent production of NO in articular chondrocytes.     

Colonic Mucosal Proteome Signature Reveals Reduced Energy Metabolism and Protein Synthesis but Activated Autophagy during Anorexia‐Induced Malnutrition in Mice

Anorexia nervosa is an eating disorder often associated with intestinal disorders. To explore the underlying mechanisms of these disorders, the colonic proteome was evaluated during activity‐based anorexia. Female C57Bl/6 mice were randomized into three groups: Control, Limited Food Access (LFA) and Activity‐Based Anorexia (ABA). LFA and ABA mice had a progressive limited access to food but only ABA mice had access to an activity wheel. On colonic mucosal protein extracts, a 2D PAGE‐based comparative proteomic analysis was then performed and differentially expressed proteins were identified by LC‐ESI‐MS/MS. Twenty‐seven nonredundant proteins that were differentially expressed between Control, LFA, and ABA groups were identified. ABA mice exhibited alteration of several mitochondrial proteins involved in energy metabolism such as dihydrolipoyl dehydrogenase and 3‐mercaptopyruvate sulfurtransferase. In addition, a downregulation of mammalian target of rapamycin (mTOR) pathway was observed leading, on the one hand, to the inhibition of protein synthesis, evaluated by puromycin incorporation and mediated by the increased phosphorylation of eukaryotic elongation factor 2, and on the other hand, to the activation of autophagy, assessed by the increase of the marker of autophagy, form LC3‐phosphatidylethanolamine conjugate/Cytosolic form of Microtubule‐associated protein 1A/1B light chain 3 (LC3II/LC3I) ratio. Colonic mucosal proteome is altered during ABA suggesting a downregulation of energy metabolism. A decrease of protein synthesis and an activation of autophagy were also observed mediated by mTOR pathway.     

Glutamate-gated chloride channel subunit cDNA sequencing of Cochliomyia hominivorax (Diptera: Calliphoridae): cDNA variants and polymorphisms

The New World screwworm (NWS) Cochliomyia hominivorax (Coquerel) is one of the major myiasis-causing flies that injures livestock and leads to losses of ~US$ 2.7 billions/year in the Neotropics. Ivermectin (IVM), a macrocyclic lactone (ML), is the most used preventive insecticide for this parasite and targets the glutamate-gated chloride (GLUCLα) channels. Several authors have associated altered GluClα homologues to MLs resistance in invertebrates, although studies about resistance in NWS are limited to other genes. Here, we aimed to characterise the NWS GluClα (ChGluClα) cDNA and to search for alterations associated with IVM resistance in NWS larvae from a bioassay. The open reading frame of the ChGluClα comprised 1,359 bp and encoded a sequence of 452 amino acids. The ChGluClα cDNAs of the bioassay larvae showed different sequences that could be splice variants, which agree with the occurrence of alternative splicing in GluClα homologues. In addition, we found cDNAs with premature stop codons and the K242R SNP, which occurred more frequently in the surviving larvae and was located close to mutation (L256F) involved in ML resistance. Although these alterations were in low frequency, the ChGluClα sequencing will allow further studies to find alterations in the gene of resistant natural populations.     

Isolation ofBacillus schlegelii,a thermophilic,hydrogen oxidizing,aerobic autotroph,from geothermal and nongeothermal environments

Thermophilic hydrogen-oxidizing strains forming round, terminal endospores were isolated from geothermal areas. They were neutrophilic and facultatively autotrophic. They resembledBacillus schlegelii, a thermophilic hydrogen bacterium found so far only in cold environments. Phenotypic similarities, as well as DNA G+C content and DNA:DNA homologies, clearly revealed that the isolated strains belonged to the taxospeciesB. schlegelii. Hence, the strains ofB. schlegelii found in cold environments are probably allochthonous, their origin being geothermal and volcanic areas.     

CXCL-16, IL-17, and bone morphogenetic protein 2 (BMP-2) are associated with overweight and obesity conditions in middle-aged and elderly women

Background

The current concept of overweight/obesity is most likely related to a combination of increased caloric intake and decreased energy expenditure. Widespread inflammation, associated with both conditions, appears to contribute to the development of some obesity-related comorbidities. Interventions that directly or indirectly target individuals at high risk of developing obesity have been largely proposed because of the increasing number of overweight/obese cases worldwide. The aim of the present study was to assess CXCL16, IL-17, and BMP-2 plasma factors in middle-aged and elderly women and relate them to an overweight or obese status. In total, 117 women were selected and grouped as eutrophic, overweight, and obese, according to anthropometric parameters. Analyses of anthropometric and circulating biochemical parameters were followed by plasma immunoassays for CXCL-16, IL-17, and BMP-2.

Results

Plasma mediators increased in all overweight and obese individuals, with the exception of BMP-2 in the elderly group, whereas CXCL16 levels were shown to differentiate overweight and obese individuals. Overweight and/or obese middle-aged and elderly individuals presented with high LDL, triglycerides, and glycemia levels. Anthropometric parameters indicating increased-cardiovascular risk were positively correlated with CXCL-16, BMP-2, and IL-17 levels in overweight and obese middle-aged and elderly individuals.

Conclusion

This study provides evidence that CXCL-16, IL-17, and BMP-2 are potential plasma indicators of inflammatory status in middle-aged and elderly women; therefore, further investigation of obesity-related comorbidities is recommended. CXCL16, in particular, could be a potential marker for middle-aged and elderly individuals transitioning from eutrophic to overweight body types, which represents an asymptomatic and dangerous condition.

     

S1 pocket fingerprints of human and bacterial methionine aminopeptidases determined using fluorogenic libraries of substrates and phosphorus based inhibitors

Methionyl aminopeptidases (MetAPs) are metallo-dependent proteases responsible for removing of N-terminal methionine residue of peptides and proteins during protein maturation and activation. In this report we use a comprehensive strategy to screen the substrate specificity of three methionyl aminopeptidases: Homo sapiens MetAP-1, Homo sapiens MetAP-2 and Escherichia coli MetAP-1. By utilizing a 65-membered fluorogenic substrate library consisting of natural and unnatural amino acids we established detailed substrate preferences of each enzyme in the S1 pocket. Our results show that this pocket is highly conserved for all investigated MetAPs, very stringent for methionine, and that several unnatural amino acids with methionine-like characteristics were also well hydrolyzed by MetAPs. The substrate-derived results were verified using several phosphonate and phosphinate-based inhibitors.     

Molecular evidence and clinical importance of β‐arrestins expression in patients with acromegaly

β‐arrestins seem to have a role in endocytosis and desensitization of somatostatin receptor subtype 2 (sst2) and could be associated with the responsiveness to somatostatin receptor ligands (SRL) in patients with acromegaly. To investigate the in vivo correlation between β‐arrestins 1 and 2 with sst2, sst5 and dopamine receptor subtype 2 (D2) expressions, and the association of β‐arrestins with response to first‐generation SRL and invasiveness in somatotropinomas. β‐arrestins 1 and 2, sst2, sst5 and D2 mRNA expressions were evaluated by quantitative real‐time RT‐PCR on tumoral tissue of 96 patients. Moreover, sst2 and sst5 protein expressions were also evaluated in 40 somatotropinomas by immunohistochemistry. Response to SRL, defined as GH <1 μg/l and normal IGF‐I levels, was assessed in 40 patients. The Knosp‐Steiner criteria were used to define invasiveness. Median β‐arrestin 1, β‐arrestin 2, sst2, sst5 and D2 mRNA copy numbers were 478; 9375; 731; 156 ; and 3989, respectively. There was a positive correlation between β‐arrestins 1 and 2 (R = 0.444, P < 0.001). However, no correlation between β‐arrestins and sst2, sst5 (mRNA and protein levels) or D2 was found. No association was found between β‐arrestins expression and SRL responsiveness or tumour invasiveness. Although previous data suggest a putative correlation between β‐arrestins and sst2, our data clearly indicated that no association existed between β‐arrestins and sst2, sst5 or D2 expression, nor with response to SRL or tumour invasiveness. Therefore, further studies are required to clarify whether β‐arrestins have a role in the response to treatment with SRL in acromegaly.