CCL2/MCP-I genotype-phenotype relationship in latent tuberculosis infection

Among the known biomarkers, chemokines, secreted by activated macrophages and T cells, attract groups of immune cells to the site of infection and may determine the clinical outcome. Association studies of CCL-2/MCP-1 -2518 A/G functional SNP linked to high and low phenotypes with tuberculosis disease susceptibility have shown conflicting results in tuberculosis. Some of these differences could be due the variability of latent infection and recent exposure in the control groups. We have therefore carried out a detailed analysis of CCL-2 genotype SNP -2518 (A/G transition) with plasma CCL-2 levels and related these levels to tuberculin skin test positivity in asymptomatic community controls with no known exposure to tuberculosis and in recently exposed household contacts of pulmonary tuberculosis patients. TST positivity was linked to higher concentrations of plasma CCL2 (Mann Whitney U test; p = 0.004) and was more marked when the G allele was present in TST+ asymptomatic controls (A/G; p = 0.01). Recent exposure also had a significant effect on CCL-2 levels and was linked to the G allele (p = 0.007). Therefore association studies for susceptibility or protection from disease should take into consideration the PPD status as well as recent exposure of the controls group used for comparison. Our results also suggest a role for CCL-2 in maintaining the integrity of granuloma in asymptomatic individuals with latent infection in high TB burden settings. Therefore additional studies into the role of CCL-2 in disease reactivation and progression are warranted.     

Nucleotide variation at Msn and Alas2, two genes flanking the centromere of the X chromosome in humans

The centromeric region of the X chromosome in humans experiences low rates of recombination over a considerable physical distance. In such a region, the effects of selection may extend to linked sites that are far away. To investigate the effects of this recombinational environment on patterns of nucleotide variability, we sequenced 4581 bp at Msn and 4697 bp at Alas2, two genes situated on either side of the X chromosome centromere, in a worldwide sample of 41 men, as well as in one common chimpanzee and one orangutan. To investigate patterns of linkage disequilibrium (LD) across the centromere, we also genotyped several informative sites from each gene in 120 men from sub-Saharan Africa. By studying X-linked loci in males, we were able to recover haplotypes and study long-range patterns of LD directly. Overall patterns of variability were remarkably similar at these two loci. Both loci exhibited (i) very low levels of nucleotide diversity (among the lowest seen in the human genome); (ii) a strong skew in the distribution of allele frequencies, with an excess of both very-low and very-high-frequency derived alleles in non-African populations; (iii) much less variation in the non-African than in the African samples; (iv) very high levels of population differentiation; and (v) complete LD among all sites within loci. We also observed significant LD between Msn and Alas2 in Africa, despite the fact that they are separated by approximately 10 Mb. These observations are difficult to reconcile with a simple demographic model but may be consistent with positive and/or purifying selection acting on loci within this large region of low recombination.     

Invasive aspergillosis promotes tumor growth and severity in a tumor-bearing mouse model

Invasive aspergillosis increases in chronic immunosuppressive diseases such as cancer. There is little information about the mechanisms by which Aspergillus infection affects the immune regulation and microenvironment of cancer cells. Hence, this study was aimed at investigating the effect of invasive aspergillosis on immunosurveillance, metastasis, and prognosis of cancer in tumor-bearing mice. After implantation of mouse mammary tumor in BALB/c mice, they were infected with Aspergillus conidia intravenously. For comparison, groups of mice were experimentally infected with Aspergillus conidia or implanted with tumor cells separately. Seven days after Aspergillus infection, the serum levels of tissue inhibitor of metalloproteinase-1 (TIMP-1) were measured by ELISA, and subsequently regulatory T lymphocytes were analyzed by flow cytometry. The survival of animals and mean tumor size were then determined. Our results indicated that tumor sizes in mice increased significantly after infection with Aspergillus conidia. Moreover, invasive aspergillosis enhanced the population of regulatory lymphocytes and level of TIMP-1. This study supports the idea that massive Aspergillus infection could stimulate tumor growth and increases the possibility of a bad prognosis. As a result, treatment of Aspergillus infection could be considered an important issue for efficient cancer therapy.     

Interaction of native and apo-carbonic anhydrase with hydrophobic adsorbents: A comparative structure-function study

Our previous studies indicated that native carbonic anhydrase does not interact with hydrophobic adsorbents and that it acquires this ability upon denaturation. In the present study, an apo form of the enzyme was prepared by removal of zinc and a comparative study was performed on some characteristic features of the apo and native forms by far- and near-UV circular dichroism (CD), intrinsic fluorescent spectroscopy, 1-anilino naphthalene-8-sulfonate (ANS) binding, fluorescence quenching by acrylamide, and Tm measurement. Results indicate that protein flexibility is enhanced and the hydrophobic sites become more exposed upon conversion to the apo form. Accordingly, the apo structure showed a greater affinity for interaction with hydrophobic adsorbents as compared with the native structure. As observed for the native enzyme, heat denaturation of the apo form promoted interaction with alkyl residues present on the adsorbents and, by cooling followed by addition of zinc, catalytically-active immobilized preparations were obtained.     

The α2 isoform of the Na,K-pump is important for intercellular communication, agonist-induced contraction, and EDHF-like response in rat mesenteric arteries

The specific role of different isoforms of the Na,K-pump in the vascular wall is still under debate. We have previously suggested that the α(2) isoform of the Na,K-pump (α(2)), Na(+), Ca(2+)-exchange (NCX), and connexin43 form a regulatory microdomain in smooth muscle cells (SMCs), which controls intercellular communication and contractile properties of the vascular wall. We have tested this hypothesis by downregulating α(2) in cultured SMCs and in small arteries with siRNA in vivo. Intercellular communication was assessed by using membrane capacitance measurements. Arteries transfected in vivo were tested for isometric and isobaric force development in vitro; [Ca(2+)](i) was measured simultaneously. Cultured rat SMCs were well-coupled electrically, but 10 μM ouabain uncoupled them. Downregulation of α(2) reduced electrical coupling between SMCs and made them insensitive to ouabain. Downregulation of α(2) in small arteries was accompanied with significant reduction in NCX expression. Acetylcholine-induced relaxation was not different between the groups, but the endothelium-dependent hyperpolarizing factor-like component of the response was significantly diminished in α(2)-downregulated arteries. Micromolar ouabain reduced in a concentration-dependent manner the amplitude of norepinephrine (NE)-induced vasomotion. Sixty percent of the α(2)-downregulated arteries did not have vasomotion, and vasomotion in the remaining 40% was ouabain insensitive. Although ouabain increased the sensitivity to NE in the control arteries, it had no effect on α(2)-downregulated arteries. In the presence of a low NE concentration the α(2)-downregulated arteries had higher [Ca(2+)](i) and tone. However, the NE EC50 was reduced under isometric conditions, and maximal contraction was reduced under isometric and isobaric conditions. The latter was caused by a reduced Ca(2+)-sensitivity. The α(2)-downregulated arteries also had reduced contraction to vasopressin, whereas the contractile response to high K(+) was not affected. Our results demonstrate the importance of α(2) for intercellular coupling in the vascular wall and its involvement in the regulation of vascular tone.     

The Interaction Between Intrathecal Administration of Low Doses of Palmitoylethanolamide and AM251 in Formalin-Induced Pain Related Behavior and Spinal Cord IL1-β Expression in Rats

Most of the modulating effects of cannabinoids on pain are through putative cannabinoid CB1 and CB2 receptors. However, the involvement of other receptors is also suggested. Cannabinoid compounds with analgesic activity such as palmitoylethanolamide (PEA) show low affinity to CB1 and CB2 receptors, yet selectively activate GPR55 receptors. The objective of the present study was to evaluate the possible role of spinal CB1 and GPR55 receptors on antinociceptive activity of PEA in formalin test as well as in the spinal expression of IL1-β in rat. Intrathecal (i.t.) administration of PEA (1, 10 μg) significantly decreased both pain-related scores in formalin test and IL1-β expression in rat spinal cord. Pretreatment of rats with low doses of CB1 receptor antagonist/GPR55 receptor agonist AM251 (10, 100 ng; i.t.), did not attenuated the effect of PEA, yet even significantly increased the effect of PEA on IL1-β expression in rat spinal cord. Interestingly, i.t. administration of low doses of AM251 per se significantly decreased both pain related behavior and spinal IL1-β expression in formalin test. These findings suggest the possible involvement of receptors other than CB1 receptors in spinal pain pathways, such as GPR55, in pain modulating activity of cannabinoids.     

Programmed death-1 gene polymorphism (PD-1.5 C/T) is associated with colon cancer

Programmed death-1 (PD-1), expressed by activated T cells, is a negative regulator of T lymphocytes. The associations of the immune response-related genes with cancer have been demonstrated. In this study, the PD-1.5 C/T (+7785) polymorphism was investigated in 200 colorectal cancer patients and 200 healthy individuals as controls by nested polymerase chain reaction-restriction fragment length polymorphism method. The genotype and allele frequencies at PD-1.5 position were not significantly different between control individuals and the overall colorectal cancer patients. However, subdivision of the patients by the location (175 colon cancer and 25 rectal cancer) revealed a significant difference between colon cancer patients and healthy individuals (p=0.026), and between colon and rectal cancer patients (p=0.017). The frequency of the CT genotype was significantly higher in colon cancer patients than in control individuals (58.3% vs. 44.8%, Bonferroni corrected p-value=0.024; OR=1.74; 95% CI=1.15-2.62), and in rectal cancer patients (58.3% vs. 28.0%, Bonferroni corrected p-value=0.012; OR=3.59; 95% CI=1.42-9.04). Characteristics of the patients including age, sex, tumor grade and stage were not associated with the PD-1.5 polymorphism. Our results show a significant association between PD-1.5 polymorphism and colon cancer. Larger numbers of patients are required to investigate comprehensively the association of rectal cancer with PD-1.5 polymorphism.     

The dual behavior of heat shock protein 70 and asymmetric dimethylarginine in relation to serum CRP levels in type 2 diabetes

Background

Experimental evidence suggests that heat shock proteins (HSP) and asymmetric dimethylarginine (ADMA) are induced in the state of chronic inflammation and stress conditions. They are both inhibitors of nitric oxide synthase (NOS). The aim of this study was to evaluate the correlation between ADMA and HSP70, in patients with type 2 diabetes with respect to serum levels of C reactive protein (CRP).

Methods

We quantified serum HSP70, ADMA and CRP in 80 newly-diagnosed patients with type 2 diabetes plus 80 age-, sex and BMI-matched healthy controls. The patients and controls were also stratified into groups of high and low CRP levels (cut-point: 2.5 mg/ml).

Results

Patients with type 2 diabetes had significantly higher serum HSP70 (0.52 [0.51–0.66] vs. 0.27 [0.26–0.36], p < 0.001), ADMA (0.86 [0.81–0.92] vs. 0.72 [0.71–0.85], p < 0.05) and CRP (2.9 [1.7–3.4] vs. 1.6[1.2–2.3], p < 0.05) compared with healthy controls. Serum HSP70 and ADMA levels were significantly correlated in patients with high CRP levels (r = 0.89, p < 0.01), whereas there were no correlation in patients with low CRP (r = − 0.37, p = 0.07) and controls. This correlation was significant (r = 0.77, p < 0.001) in patients with high CRP and also in patients with low CRP levels (r = − 0.51, p < 0.05), after multiple adjustments for LDL and HDL levels.

Discussion

We showed that, in a state of high inflammation; serum levels of ADMA parallel the HSP70 levels. However in low inflammation, they are negatively correlated. The duality in HSP70 and ADMA correlation may be related to the duality of NOS function in low and high CRP levels.