A novel polymorphism in the MCP-1 gene regulatory region that influences MCP-1 expression

Monocyte chemotactic protein-1 (MCP-1) and growth factors called into question as markers of prolonged psychosocial stress

BACKGROUND

Psychosocial stress is becoming a major contributor to increased mental ill-health and sick leave in many countries. Valid markers of chronic stress would be valuable for diagnostic and prognostic purposes. A recent study suggested monocyte chemotactic protein-1 (MCP-1), epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) as markers of chronic stress. We aimed to confirm these potential biomarkers of prolonged psychosocial stress in female patients.

METHODOLOGY/PRINCIPAL FINDINGS

Circulating levels of MCP-1, EGF and VEGF, along with several other cytokines, were measured in plasma from 42 female patients suffering from exhaustion due to prolonged psychosocial stress and 42 control subjects, using a protein biochip immunoassay. There were no significant differences between patients and controls in any of the cytokines or growth factors analyzed. Furthermore, when using a different protein bioassay and reanalyzing MCP-1 and VEGF in the same samples, markedly different levels were obtained. To further explore if inflammation is present in patients with exhaustion, the classical inflammatory marker C-reactive protein (CRP) was measured in another group of patients (n=89) and controls (n=88) showing a small but significant increase of CRP levels in the patients.

CONCLUSIONS/SIGNIFICANCE

MCP-1, EGF and VEGF may not be suitable markers of prolonged psychosocial stress as previously suggested. Furthermore, significant differences were obtained when using two different protein assays measuring the same samples, indicating that comparing studies where different analytic techniques have been used might be difficult. Increased levels of CRP indicate that low-grade inflammation might be present in patients with exhaustion due to prolonged stress exposure but this inflammation does not seem to be reflected by increase in circulating MCP-1 or other cytokines measured.

Association of monocyte chemoattractant protein-1 -2518 polymorphism with metabolic syndrome in a South Indian cohort

BACKGROUND

Previous reports have indicated an association of monocyte chemoattractant protein-1 (MCP-1) with risk factors for atherosclerosis and coronary artery disease (CAD). Because some of these risk factors form components of metabolic syndrome, in the present study, we investigated the association of an important promoter region polymorphism of MCP-1, A-2518G, and its serum levels with metabolic syndrome in a South Indian cohort.

METHODS

The study comprised of 126 healthy subjects aged 30-59 years from South India. Subjects were classified on the basis of presence or absence of metabolic syndrome and metabolic syndrome components as per the International Diabetes Federation definition. MCP-1 genotyping was done by polymerase chain reaction restriction fragment-length polymorphism, and serum levels were estimated by enzyme-linked immunosorbent assay.

RESULTS

The MCP-1 -2518G allele frequency in the study population was 32.9% and the mean MCP-1 serum levels were 523 +/- 272.3 pg/mL. Subjects with metabolic syndrome showed an increased presence of the MCP-1 -2518G allele in comparison to those without metabolic syndrome (odds ratio [OR] = 5.03, P = 0.02). The association was related to a higher proportion of this allele in subjects with increased waist circumference (OR = 3.78, P = 0.05).

CONCLUSIONS

The MCP-1 -2518G allele may be contributing to atherosclerosis and CAD by conferring an increased risk to metabolic syndrome and/or obesity.

Urine osteoprotegerin and monocyte chemoattractant protein-1 in lupus nephritis

OBJECTIVE

Renal biopsy is the "gold standard" to determine renal activity in systemic lupus erythematosus (SLE), but it is expensive, invasive, and carries risk. Osteoprotegerin (OPG) is produced by the heart, lungs, kidney, and bone. Monocyte chemoattractant protein-1 (MCP-1), a chemotactic cytokine, is involved in the progression of glomerular and tubulointerstitial injury. We investigated both urine OPG and MCP-1 as potential biomarkers for lupus nephritis.

METHODS

Our subjects, 87 patients with SLE (88% women; 48% African American, 41% Caucasian, 11% other), mean age 44 years, were followed monthly to quarterly. Urinary OPG (pg/ml) and MCP-1 (pg/ml) were measured (Luminex MAP bead assay).

RESULTS

OPG concentrations were strongly associated with global disease activity and with both renal activity on a visual analog scale (VAS) (p = 0.0006) and renal disease activity descriptors of the SELENA SLEDAI, including hematuria (p = 0.001) and a positive anti-dsDNA (p = 0.013). MCP-1 was also associated with the renal VAS (p = 0.032), renal disease activity descriptors of SELENA SLEDAI, including hematuria (p = 0.027), and with a positive anti-dsDNA (p = 0.016). We also examined the relationship between the biomarkers and having a urine protein to creatinine ratio (pr/cr) > or = 0.5. Among patients with medium or high OPG, 46% had urine pr/cr > or = 0.5, compared to only 23% among those with low OPG (p = 0.032). The 2 biomarkers were strongly correlated with each other (Spearman correlation coefficient 0.77, p < 0.0001).

CONCLUSION

The lack of availability of urine biomarkers has hampered development of new therapies for lupus nephritis. Urine MCP-1 and OPG were both associated with measures of lupus renal disease activity. Medium or high levels of OPG were predictive of a urine protein/creatinine ratio of > or = 0.5. Further study, including longitudinal assessment and correlation with concurrent renal biopsies, is necessary before this assay can be used in the routine clinic setting.

Folate/homocysteine phenotypes and MTHFR 677C>T genotypes are associated with serum levels of monocyte chemoattractant protein-1

Monocyte chemoattractant protein-1 (MCP-1) is a chemokine that recruits monocytes into the subendothelial cell layer in atherosclerotic lesions. Elevated homocysteine (hyperhomocysteinemia), which is usually associated with low-folate status, is a known risk factor for many pathologies with inflammatory etiologies. The present study was undertaken to examine whether there are associations between MCP-1 concentrations and folate/Hcy phenotype or methylenetetrahydrofolate reductase (MTHFR) 677C>T genotype in healthy young adults. In females, MCP-1 concentrations were positively correlated with Hcy and negatively correlated with both serum and red blood cell folate; female smokers and MTHFR 677T carriers had particularly elevated MCP-1 concentrations. Similar relationships were not seen in males. These findings may have implications for understanding the female predominance observed for a range of autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis.

Short CommunicationThe MCP-1 Promoter -2518 Polymorphism in Behcet's Disease: Correlation Between Allele Types, MCP-1 Production and Clinical Symptoms among Korean Patients

OBJECTIVE

To compare the G vs. A variation at the MCP-1 promoter -2518 position among normal Koreans and Behcet patients, and to investigate possible association of this polymorphism with disease pathogenesis.

METHODS

The allele type of -2518 polymorphism was determined by restriction fragment length polymorphism of Pvu II. The level of MCP-1 in serum and culture supernatent was measured by sandwich ELISA.

RESULTS

The average serum level of MCP-1 in Behcet patients was 2.37 times higher than in normal controls. The serum MCP-1 concentration was higher in G-allele carriers than in AA homozygotes, and symptoms accompanying graver cases of Behcet's disease, such as gastrointestinal inflammation and uveitis, were more frequent in patients with the G-allele. However, the frequency of G-allele in patient group was not higher than that in healthy Koreans, probably due to the dominance of G-allele in general Korean population. When stimulated in vitro with IL-1beta and LPS, the mononuclear cells from patients carrying the G-allele showed a steeper increase in MCP-1 production than the boost observed in AA homozygotes.

CONCLUSION

Although the allele frequency of MCP-1 promoter -2518 polymorphism is not likely to be the reason for the elevated serum MCP-1 level in Korean patients with Behcet's disease, it is possible that proinflammatory factors induced in patients' serum cause stronger activation of MCP-1 expression from the G-type promoter, as well as increased incidence of uveitis and gastric ulcer, among carriers of the G-allele.

Single nucleotide polymorphisms in monocyte chemoattractant protein-1 and its receptor act synergistically to increase the risk of carotid atherosclerosis

BACKGROUND

Monocyte chemoattractant protein 1 (MCP-1), acting in concert with its receptor chemokine receptor 2 (CCR2), promotes recruitment of macrophages into atherosclerotic plaque. We examined whether single nucleotide polymorphism (SNP) variants in the MCP-1 or CCR2 genes independently or in combination are associated with carotid artery atherosclerosis in an African American population at increased risk of vascular disease.

METHODS

Four SNPs in MCP-1 and 1 in CCR2 were genotyped. Carotid artery duplex ultrasonography was used to identify the presence or absence of carotid plaque >1 mm. The study population included 325 apparently healthy 30- to 59-year-old black siblings of 185 probands with premature coronary artery disease (<60 years old). Associations between each independent SNP and the presence of carotid plaque were examined using multivariate logistic regression models adjusted for age, sex, educational level, diabetes, smoking, hypertension, obesity, low-density lipoprotein cholesterol and non-independence within families. Interactions between SNPs in the MCP-1 gene and the SNP in the CCR2 gene were examined by multivariate analysis.

RESULTS

Siblings were 32% males, with a mean age of 46 +/- 7 years, and 77 (24%) demonstrated carotid plaque. In multivariate analyses, the CC genotype of MCP-1 SNP rs2857656 was independently associated with plaque (p = 0.05). Subjects who had both the MCP-1 CC genotype and were heterozygotic or homozygotic for the CCR2 V64I genotype (rs1799864; n = 12) had an even higher risk of carotid atherosclerosis (odds ratio 6.14, 95% confidence interval 1.82-20.73; p = 0.0037).

CONCLUSION

The MCP-1 rs2857656 CC genotype is independently associated with carotid artery plaque in African American from families with premature coronary artery disease. The combination of the MCP-1 CC homozygous genotype and the homozygotic or heterozygote CCR2 V64I genotype is associated with a particularly high prevalence of carotid artery plaque.

Association of monocyte chemoattractant protein 1 gene polymorphism with susceptibility to nonfamilial idiopathic dilated cardiomyopathy

BACKGROUND

The cytotoxic action of leukocytes is known to be a probable cause of the cardiac myocyte damage seen in idiopathic dilated cardiomyopathy (IDC). Monocyte chemoattractant protein 1 (MCP-1) contributes to enhanced leukocyte recruitment and activation resulting in chronic damage of cardiomyocytes. MCP-1 has been reported to be dynamically regulated in IDC and may contribute to the deterioration of left ventricular function. In addition, a polymorphism at -2518 (G/A) in the MCP-1 gene affects the level of MCP-1 expression in response to an inflammatory stimulus.

METHODS AND RESULTS

We genotyped the polymorphism at -2518 G/A in the MCP-1 gene in 73 Japanese patients with nonfamilial IDC and 349 healthy controls. The distribution of the MCP-1 genotypes in the IDC patients differed significantly from the controls (p=0.016). In a dominant G allele model, there was a significant difference in the distribution of genotypes between the two groups (p<0.01). The odds ratio for nonfamilial IDC associated with the GG vs. non-GG genotype was 10.4 (95% CI=1.7-64.5) after adjustment for the confounding factors.

CONCLUSIONS

These findings suggest that the G allele at -2518 in the MCP-1 gene may be a novel genetic marker of susceptibility to nonfamilial IDC.

Sequential evaluation of serum monocyte chemotactic protein 1 among asymptomatic state and acute exacerbation and remission of asthma in children

BACKGROUND

Monocyte chemotactic protein 1 (MCP-1) plays an important role in various immune and allergic disorders since it is a potent chemo-attractant for inflammatory cells, such as eosinophils, memory T cells, and monocytes.

OBJECTIVE

To investigate serum MCP-1 during asymptomatic state and acute attacks of bronchial asthma.

METHODS

In this longitudinal cohort design study, sequential serum levels of MCP-1 were measured by a sandwich enzyme-linked immunosorbent assay (ELISA). Twenty-four asthma patients' MCP-1 levels were examined at 5 time points: during the asymptomatic phase, in an acute wheezing episode, and at 1 week, 1 month, and 2 months after acute asthma attack. Fifteen children without asthma were enrolled as control.

RESULTS

During the asymptomatic phase of asthma, serum MCP-1 levels were significantly higher than that of normal controls (329.57 +/- 99.20 pg/ml vs. 213.63 +/- 77.29 pg/ml, p = 0.001). In comparison with the asymptomatic phase, the serum MCP-1 levels during the acute asthma attack were significantly higher (682.88 +/- 88.45 pg/ml vs. 329.57 +/- 99.20 pg/ml, p < 0.001). After treatment of acute asthma exacerbation, all of the serum MCP-1 levels declined within 1 week, but were still higher than control 2 months later.

CONCLUSION

In asthma patients, the consistently elevated serum levels of MCP-1 suggest its role in the pathogenesis of bronchial asthma - not only in the chronic inflammatory processes, but also in acute asthma attack exacerbation. These findings suggest a possible role for MCP-1 in the pathogenesis of asthma and a potential role for its use in anti-asthma treatment in the future.

The impact of immune gene polymorphisms in kidney and liver transplantation

Since the completion of the Human Genome Project, it has become clear that genetic variation exists among individuals that can affect functional gene expression. This finding raises the possibility that differences in genetic phenotypes may account for the interindividual responses seen in the context of the alloimmune response. This review highlights studies examining the relative role of immunologic gene polymorphism in the context of renal and liver transplant outcomes (eg, acute rejection and graft survival). Furthermore, it examines the limitations and pitfalls in the study designs and concludes with the potential of single nucleotide polymorphism analysis in the future care of transplant recipients.

Polymorphisms of the methylenetetrahydrofolate reductase, vascular endothelial growth factor, endothelial nitric oxide synthase, monocyte chemoattractant protein-1 and apolipoprotein E genes are not associated with carotid intima-media thickness

BACKGROUND

Single nucleotide polymorphisms in the 5,10-methylenetetrahydrofolate reductase (MTHFR), vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS), monocyte chemoattractant protein-1 (MCP-1) and apolipoprotein E (ApoE) genes appear to be a genetic risk factor for atherosclerosis. Common carotid intima-media thickness (cIMT) provides information on the severity of atherosclerosis.

OBJECTIVE

To investigate the relationship between cIMT and gene polymorphisms associated with atherosclerosis in Turkish patients with coronary artery disease (CAD).

METHODS

Sixty-two patients with angiographically diagnosed stable CAD were divided into two groups according to their cIMT values (group 1: n=35, cIMT of 1 mm or greater; group 2: n=27, cIMT of less than 1 mm). MTHFR 677 C/T, VEGF --460 C/T, eNOS 894 G/T, MCP-1 --2518 A/G and ApoE (E2, E3 and E4) gene polymorphisms (where A is adenine, C is cytosine, G is guanine and T is thymine) were analyzed by polymerase chain reaction and restriction fragment length polymorphism. Evaluations of cardiovascular risk factors and coronary atherosclerotic lesions were performed in all patients. Serum homocysteine and high-sensitivity C-reactive protein were measured and compared between the two groups.

RESULTS

Serum high-sensitivity C-reactive protein (P=0.04) and homocysteine (P=0.006) levels were higher in group 1 than in group 2. The ratio of multivessel CAD and previous myocardial infarction was significantly higher in group 1 than in group 2 (P=0.014). In the study population, no significant difference in cIMT was observed according to the polymorphisms studied. Only hyperhomocysteinemia (OR 1.17 [95% CI 1.01 to 1.35], P=0.033) and previous myocardial infarction (OR 3.76 [95% CI 1.10 to 12.81], P=0.034) maintained a significant correlation with cIMT on multiple logistic regression analysis.

CONCLUSION

cIMT is increased in patients with hyperhomocysteinemia, inflammation and extended CAD. MTHFR 677 C/T, VEGF --460 C/T, eNOS 894 G/T, MCP-1 --2518 A/G and ApoE single nucleotide polymorphisms were not associated with increased cIMT.

Association of IL6 and CCL2 gene polymorphisms with the outcome of allogeneic haematopoietic stem cell transplantation

Various polymorphisms of non-HLA genes have recently been investigated as candidate risk factors in allogeneic haematopoietic SCT (aHSCT). Our study aimed at exploring possible associations of IL6 and CCL2 single nucleotide polymorphisms (SNP) with aHSCT outcome. A total of 166 HLA-identical aHSCT pairs recruited in were genotyped for IL6 -174 G/C, IL6 -597 G/A, CCL2 -2518 A/G and CCL2 -2076 A/T SNPs by PCR with sequence-specific primers (PCR-SSP). The association between IL6 -174 GG genotype and increased risk of acute GVHD was found in whole study group (P=0.03) and in the subgroup of related aHSCT (P=0.01), association between IL6 -597 GG genotype and the occurrence of acute GVHD was detected only in the related aHSCT pairs (P=0.02). Furthermore, reduction in OS was revealed among recipients possessing IL6 -174(*)G allele in the group of related aHSCT pairs (P=0.04). Presence of CCL2 -2076 TT genotype was associated with decrease of OS (P=0.04) and increase of TRM (P=0.02) in patients transplanted by related donor. These results, in the context of previous findings, suggest that IL6 gene polymorphisms may be associated with aHSCT outcome, particularly in patients transplanted from a related donor.

Chemokine-enhanced chemotaxis of lymphangioleiomyomatosis cells with mutations in the tumor suppressor TSC2 gene

Lymphangioleiomyomatosis (LAM) is characterized by cystic lung destruction caused by LAM cells (smooth-muscle-like cells) that have mutations in the tumor suppressor genes tuberous sclerosis complex (TSC) 1 or 2 and have the capacity to metastasize. Since chemokines and their receptors function in chemotaxis of metastatic cells, we hypothesized that LAM cells may be recruited by chemokine(s) in the lung. Quantification of 25 chemokines in bronchoalveolar lavage fluid from LAM patients and healthy volunteers revealed that concentrations of CCL2, CXCL1, and CXCL5 were significantly higher in samples from LAM patients than those from healthy volunteers. In vitro, CCL2 or MCP-1 induced selective migration of cells, showing loss of heterozygosity of TSC2 from a heterogeneous population of cells grown from explanted LAM lungs. Additionally, the frequencies of single-nucleotide polymorphisms in the CCL2 gene promoter region differed significantly in LAM patients and healthy volunteers (p = 0.018), and one polymorphism was associated significantly more frequently with the decline of lung function. The presence (i.e., potential functionality) of chemokine receptors was evaluated using immunohistochemistry in lung sections from 30 LAM patients. Expression of chemokines and these receptors varied among LAM patients and differed from that seen in some cancers (e.g., breast cancer and melanoma cells). These observations are consistent with the notion that chemokines such as CCL2 may serve to determine mobility and specify the site of metastasis of the LAM cell.

The role of host genetics in the susceptibility for HIV-associated neurocognitive disorders

Despite progress in the treatment of the Human Immunodeficiency virus (HIV), there continues to be a high prevalence of infected individuals who develop neurocognitive deficits and disorders. Our understanding of the potential cause of HIV-associated neurocognitive disorders (HAND) continues to develop on many fronts. Among them is the study of host genetics. Here, we review the most current information regarding the association between host genetics and risk for HIV infection, AIDS, and HAND. We focus on the role of dopamine dysfunction in the etiology of HAND, and propose a number of genetic polymorphisms within genes related to dopaminergic functioning and other neurobiological factors that may confer vulnerability or protection against HAND.

Investigation of chromosome 17 candidate genes in susceptibility to TB in a South African population

Chromosome 17 is known to contain TB susceptibility genes. Polymorphisms in two of these genes, namely NOS2A and CCL2, have been associated with TB in various populations. To investigate a possible association of gene variants with TB in the South African Coloured population we genotyped SNPs from NOS2A and CCL2 in over 800 TB cases and controls. We found a significant association between TB and two haplotypes, containing the functional rs9282799 and rs8078340 SNPs, in the NOS2A promoter. The T allele of rs8078340, found in the haplotype over-represented in cases (p=0.015, p(c)=0.038, OR=1.4, 95% CI [1.1-1.8]), was previously shown to decrease the quantity of DNA-protein complex bound as well as the duration of binding and may decrease nitric oxide (NO) production. The C allele of rs8078340 was present in the haplotype more frequent in controls (p=0.011, p(c)=0.029, OR=1.4, 95% CI [1.1-1.8]). In the single-point analysis of NOS2A, rs2779249 (previously associated with TB in Brazilians) and the functional rs8078340 were nominally associated with disease. No association was found between any of the other SNPs or haplotypes studied and TB. This study presents evidence that haplotypes in the NOS2A promoter influence susceptibility to TB and confirms the importance of NO production in the disease.

Genetic polymorphisms of RANTES, IL1-A, MCP-1 and TNF-A genes in patients with prostate cancer

BACKGROUND

Inflammation has been implicated as an etiological factor in several human cancers, including prostate cancer. Allelic variants of the genes involved in inflammatory pathways are logical candidates as genetic determinants of prostate cancer risk. The purpose of this study was to investigate whether single nucleotide polymorphisms of genes that lead to increased levels of pro-inflammatory cytokines and chemokines are associated with an increased prostate cancer risk.

METHODS

A case-control study design was used to test the association between prostate cancer risk and the polymorphisms TNF-A-308 A/G (rs 1800629), RANTES-403 G/A (rs 2107538), IL1-A-889 C/T (rs 1800587) and MCP-1 2518 G/A (rs 1024611) in 296 patients diagnosed with prostate cancer and in 311 healthy controls from the same area.

RESULTS

Diagnosis of prostate cancer was significantly associated with TNF-A GA + AA genotype (OR, 1.61; 95% CI, 1.09-2.64) and RANTES GA + AA genotype (OR, 1.44; 95% CI, 1.09-2.38). A alleles in TNF-A and RANTES influenced prostate cancer susceptibility and acted independently of each other in these subjects. No epistatic effect was found for the combination of different polymorphisms studied. Finally, no overall association was found between prostate cancer risk and IL1-A or MCP-1 polymorphisms.

CONCLUSION

Our results and previously published findings on genes associated with innate immunity support the hypothesis that polymorphisms in proinflammatory genes may be important in prostate cancer development.

The up-regulation of monocyte chemoattractant protein-1 (MCP-1) in Ea.hy 926 endothelial cells under long-term low folate stress is mediated by the p38 MAPK pathway

OBJECTIVE

Monocyte chemoattractant protein-1 (MCP-1), encoded by the CCL2 gene, plays an important role in the initiation and progression of atherosclerosis. Ea.hy 926 endothelial cells grown under low folate conditions (LO cells) synthesize more MCP-1 mRNA and secrete more MCP-1 protein than folate-replete control cells (HI cells). We investigated the mechanisms underlying the modulation of MCP-1 expression by long-term "folate stress".

METHODS AND RESULTS

CCL2 transcription, assessed using promoter-reporter assays, is up-regulated in LO cells relative to HI cells, whereas MCP-1 mRNA stability is unchanged. This quantitative transcriptional bias under chronic low folate conditions is not attributable to differences in active NF-kappaB, but is associated with elevated levels of both total p38 and phospho-p38 that are detectable by Western immunoblotting. Transient, acute methotrexate-mediated folate depletion or exposure to high concentrations of homocysteine (Hcy) had no effect on MCP-1 synthesis by Ea.hy 926 cells. The p38 inhibitor SB-203580 abolished the excess MCP-1 production by LO cells. The quantitative transcriptional bias of CCL2 in LO cells was retained following massive induction by TNF-alpha.

CONCLUSION

During long-term folate stress, p38 is the primary determinant of CCL2 transcription. Long-term folate insufficiency "primes" Ea.hy 926 endothelial cells to have a quantitatively more vigorous response to cytokine-mediated inflammatory stress.

MCP-1 and CCR2 gene polymorphisms in Czech patients with allergic disorders

Several lines of evidence suggest that chemokines play an important role in asthma and allergy. We analysed polymorphisms at -2518A/G and -2076A/T of MCP-1 and V64I of CCR2 gene in healthy subjects (n = 306) and allergic patients (n = 332). Allele and genotype frequencies did not differ significantly between groups. Nevertheless, MCP-1 variants were associated with allergen sensitization. The results suggest that MCP-1, but not CCR2 gene variants, may participate in the pathogenesis of allergic phenotypes at least in the Caucasian population.

Genetic and biochemical determinants of serum concentrations of monocyte chemoattractant protein-1, a potential neural tube defect risk factor

BACKGROUND

Women with the AA genotype at the (-2518)A>G promoter polymorphism of CCL-2, which encodes the potent pro-inflammatory chemokine monocyte chemoattractant protein 1 (MCP-1), may be at increased risk for having offspring affected by spina bifida. As the A allele at this locus has been associated with decreased transcription of MCP-1 mRNA relative to the G allele, the observed genetic association suggests that the risk of spina bifida may be increased in the offspring of women with low MCP-1 levels. The present study was undertaken to identify potential determinants of MCP-1 levels in women of reproductive age.

METHODS

A small cohort of Caucasian and African-American women of reproductive age was recruited to participate in an exploratory investigation of the determinants of several disease-related, biochemical phenotypes, including MCP-1. Subjects completed a brief questionnaire and provided a fasting blood sample for biochemical and genetic studies. Potential biochemical, genetic, and lifestyle factors were assessed for their association with MCP-1 levels using linear regression analyses.

RESULTS

In this cohort, MCP-1 levels were significantly higher in Caucasians as compared to African-Americans. Further, among women of both races, there was evidence that MCP-1 levels were associated with smoking status, MTHFR 677C>T genotype, and red blood cell tetrahydrofolate levels.

CONCLUSIONS

The results of these analyses indicate that, if maternal CCL-2 genotype is related to the risk of spina bifida, this relationship is likely to be more complex than initially hypothesized, perhaps depending upon folate intake, MTHFR 677C>T genotype, the distribution of folate derivatives, and immune/inflammatory activity.

Polymorphism in the microglial cell-mobilizing CX3CR1 gene is associated with survival in patients with glioblastoma

PURPOSE

Few reliable prognostic molecular markers have been characterized for glioblastoma multiforme (GBM), considered the deadliest of human cancers. We hypothesized that genetic polymorphisms in chemokines and their receptors, which together control microglial cell mobilization, may influence survival.

METHODS

Distributions of one polymorphism of the chemokine CCL2 (-2518A<G) and two polymorphisms of the chemokine receptor CX3CR1 (termed V249I and T280M) were determined in a prospective series of 230 patients with GBM and correlated with overall survival. The replication study used data from a retrospective series of 106 additional patients with GBM. The extent of microglial cell infiltration was assessed by immunochemistry in 102 tumor specimens.

RESULTS

Survival analysis showed that the common CX3CR1-I249 allele was an independent favorable prognostic factor in both groups, prospective and retrospective, with hazard ratios of 0.619 (95% CI, 0.451 to 0.850; P = .0031) and 0.354 (95% CI, 0.217 to 0.580; P < .0001), respectively. This beneficial effect was observed only in patients who underwent surgery. Patients with only this CX3CR1-I249 allele had a substantially longer mean survival (23.5 v 14.1 months; P < .0001). The CCL2-2518G allele was not associated with patient survival. Immunohistochemical analysis of primary tumor biopsies showed that the common CX3CR1 variant allele was associated with reduced microglial cell infiltration.

CONCLUSION

The common CX3CR1 allelic variant was associated with increased GBM survival and with reduced tumor infiltration by microglia. The CX3CR1 polymorphism does not seem to be a risk factor for GBM but may prove useful in predicting survival.

Functional gene polymorphisms in canadian aboriginal populations with high rates of tuberculosis

The present study determined whether a pattern of functional single-nucleotide polymorphisms (SNPs) was present that could predispose a Dené cohort to a suboptimal response to Mycobacterium tuberculosis. Compared with a Caucasian cohort, the Dené and Cree were found to maintain a significantly higher frequency of SNPs associated with low expression of vitamin D receptor (VDR), interferon (IFN)-gamma (+874), and tumor necrosis factor-alpha (-308) and high production of monocyte chemoattractant protein (MCP)-1 (-2518) and interleukin (IL)-6 (-174). Given the roles played by IFN-gamma and VDR in facilitating macrophage containment of M. tuberculosis and the opposing role of MCP-1 and IL-6, the observed allelic variation by ethnicity may in part contribute to the high rates of tuberculosis among the Dené.

Recognition of genetic factors influencing the progression of hepatitis C : potential for personalized therapy

Infection with hepatitis C virus (HCV) is a major cause of chronic liver disease. Hepatic fibrosis may develop in subjects with chronic HCV infection, culminating in cirrhosis and an increased risk of hepatocellular carcinoma. The rate of development of fibrosis varies substantially between individuals; while it is influenced by a number of demographic and environmental factors, these account for only a small proportion of the variability. There are no clinical markers or tests that predict the rate of fibrosis progression in an individual subject. Thus, there has been increasing interest in the influence of host genetic factors on the rate of disease progression, and whether a genetic signature can be developed to reliably identify individuals at risk of severe disease. Numerous case-control, candidate gene, allele-association studies have examined the relationship between host single nucleotide polymorphisms or other genetic mutations and fibrosis in patients with chronic HCV infection. However, these studies have generally been irreproducible and disappointing. As seen with genetic studies for other diseases, small study cohorts and poor study design have contributed to limited meaningful findings. The successful determination of genetic signatures for fibrosis progression in chronic HCV will require multicenter collaborations using genome-wide association studies, with large, phenotypically well-defined sample sets. While these studies will require a significant financial commitment, a successful outcome offers the potential for personalized therapy and better patient management.

Polymorphisms affecting gene transcription and mRNA processing in pharmacogenetic candidate genes: detection through allelic expression imbalance in human target tissues

BACKGROUND

Genetic variation in mRNA expression plays a critical role in human phenotypic diversity, but it has proven difficult to detect regulatory polymorphisms - mostly single nucleotide polymorphisms (rSNPs). Additionally, variants in the transcribed region, termed here 'structural RNA SNPs' (srSNPs), can affect mRNA processing and turnover. Both rSNPs and srSNPs cause allelic mRNA expression imbalance (AEI) in heterozygous individuals. We have used AEI to discover and characterize regulatory polymorphisms in OPRM1, TPH2, MDR1, DRD2, and VKORC1. The objective of this study was to use AEI to determine the extent of cis-regulatory factors in pharmacogenetic genes.

METHODS

We applied a rapid and accurate AEI methodology for testing 42 genes implicated in cardiovascular and central nervous system diseases, and affecting drug metabolism and transport. Each gene was analyzed in physiologically relevant human autopsy tissues, including brain, heart, liver, intestines, and lymphocytes.

RESULTS

Substantial AEI was observed in approximately 55% of the surveyed genes. Focusing on cardiovascular candidate genes in human hearts, AEI analysis revealed frequent cis-acting regulatory factors in ACE and SOD2 mRNA expression, having potential clinical significance. SNP scanning to locate regulatory polymorphisms in a number of genes failed to support several previously proposed promoter SNPs discovered with use of reporter gene assays in heterologous tissues, while srSNPs appear more frequent than expected. Computational analysis of mRNA folding indicates that approximately 90% of srSNPs affect mRNA folding, and hence potentially function.

CONCLUSION

Our results indicate that both rSNPs and srSNPs represent a still largely untapped reservoir of variants that contribute to human phenotypic diversity.

CCL2 increases X4-tropic HIV-1 entry into resting CD4+ T cells

During human immunodeficiency virus type 1 (HIV-1) infection, there is a strong positive correlation between CCL2 levels and HIV viral load. To determine whether CCL2 alters HIV-1 infection of resting CD4(+) T cells, we infected purified resting CD4(+) T cells after incubation with CCL2. We show that CCL2 up-regulates CXCR4 on resting CD4(+) T cells in a CCR2-dependent mechanism, and that this augmentation of CXCR4 expression by CCL2 increases the ability of these cells to be chemoattracted to CXCR4 using gp120 and renders them more permissive to X4-tropic HIV-1 infection. Thus, CCL2 has the capacity to render a large population of lymphocytes more susceptible to HIV-1 late in the course of infection.

A polymorphism in the CCL2 chemokine gene is associated with asthma risk: a case-control and a family study in Tunisia

Asthma is a complex genetic disorder characterized by chronic airway inflammation. We hypothesized that genetic polymorphisms in chemokines and their receptors alter leukocyte mobilization and may thus influence the risk and severity of childhood asthma. Distributions of the chemokine CCL2-2578G, CCL2-927C, CCR2-V64I, CX3CR1-V249I and CX3CR1-T280M receptor polymorphisms were examined in a case-control study of 121 children with asthma and 226 age-matched healthy controls and then replicated in a family study of 99 simplex families (297 individuals). The case-control study revealed that the CCL2-2578G allele was less frequent in children with than in those without asthma (P=0.0012). No association with asthma was found for the CCL2-927, CCR2 or CX3CR1 polymorphisms. The finding in the family study that the CCL2-2578G allele was transmitted less often by heterozygous parents to their children with asthma (P=0.0016) confirms the association of CCL2-2578G with asthma risk. Biochemical studies indicated that plasma CCL2 concentrations were higher in both patients (P=0.0214) and controls (P=0.001) carrying the G allele than in subjects with other polymorphisms. Both case-control and family-based studies suggest a protective effect of allele CCL2-2578G in Tunisian asthmatic children.

Profiling of genetic variations in inflammation pathway genes in relation to bladder cancer predisposition

PURPOSE

Compelling evidence has indicated that inflammation plays an important role in cancer development. We sought to test the hypothesis that common sequence variants in the inflammation pathway modulate bladder cancer risk.

EXPERIMENTAL DESIGN

We genotyped 59 potentially functional single nucleotide polymorphisms from 35 candidate inflammation genes in a case-control study including 635 Caucasian bladder cancer patients and 635 matched controls.

RESULTS

The most significant finding was in the 3'-untranslated region of PTGS2 (exon10+837T>C, rs5275), which was associated with a significantly reduced risk (odds ratio, 0.68; 95% confidence interval, 0.54-0.87; P=0.002) and remained significant after multiple comparison adjustment. Consistently, the most common PTGS2 haplotype containing the common allele of exon10+837T>C was associated with a significantly increased risk (odds ratio, 1.27; 95% confidence interval, 1.06-1.52; P=0.008). In contrast, the haplotypes containing at least one variant allele of exon10+837T>C were all associated with a decreased risk. In a combined analysis to assess the cumulative effects of inflammation single nucleotide polymorphisms on bladder cancer risk, we found that in the anti-inflammation pathway, but not in the proinflammation pathway, when compared with individuals with a few adverse alleles, individuals with more adverse alleles had a significantly increased risk in a dose-dependent manner (P(trend)=0.012). To further elucidate the functional mechanism of these associations, we redefined the adverse alleles based on literature-reported functional results and found that individuals with a higher number of inflammation-enhancing alleles in the anti-inflammation pathway exhibited a greater bladder cancer risk.

CONCLUSIONS

Our results strongly suggest that common variants in inflammation genes affect bladder cancer susceptibility individually and jointly.

Polymorphisms of the MCP-1 and HSP70-2 genes in Korean patients with alcoholic chronic pancreatitis

Alcoholic chronic pancreatitis (ACP) develops in only a small number of alcoholics. Monocyte chemotactic protein-1 (MCP-1) and heat-shock protein 70-2 (HSP70-2) polymorphisms have been reported to be associated with the severity of acute pancreatitis. However, their role in pathogenesis of ACP has not been investigated. A genetic association study for susceptibility and severity was performed on 79 male Korean ACP patients and 82 male controls. MCP-1 and HSP70-2 genotypes were determined using a fluorescence polarization detection method. The genotypes and G allele frequencies were no different in patients and controls. However, MCP-1 G allele had an effect on the development of severe ACP, when its frequency was compared in mild to moderate and severe ACP (29.6 vs. 56.0%, P = 0.02). The MCP-1 and HSP70-2 polymorphisms do not play a major role in the development of ACP in Koreans. However, MCP-1 polymorphism may be associated with the severity of ACP.

Prep1/Pbx2 complexes regulate CCL2 expression through the -2578 guanine polymorphism

CC-chemokine ligand 2 (CCL2) is the major chemoattractant protein that recruits monocytes to sites of inflammation and increased expression of CCL2 is associated with numerous inflammatory diseases including human immunodeficiency virus-associated dementia (HIV-D). The -2578 guanine polymorphism in the CCL2 promoter has been associated with increased expression of CCL2 as well as pathogenesis of HIV-D; however, the molecular mechanism of regulation is unknown. We propose a molecular model for -2578 G-regulated CCL2 expression in astrocytes, which are major producers of CCL2 in the brain. The -2578 G polymorphism creates a consensus-binding site for the transcriptional regulator Prep1, which along with binding partner Pbx2, preferentially binds the -2578 G allele. CCL2 promoters harboring the G allele under unstimulated conditions exhibit a lower basal activity compared to the ancestral A allele. Upon interleukin-1 beta stimulation, Prep1/Pbx2 complexes maintain the ability to bind -2578 G alleles, yet transcription levels from promoters that harbor the A or G allele are equally activated, suggesting that the -2578 region does not influence CCL2 transcription under proinflammatory conditions. Therefore, promoters that harbor the -2578 G allele undergo a higher fold induction and by extension, individuals homozygous for -2578 G would be expected to exhibit hyper-responsive CCL2 phenotypes during periods of inflammation.

Mcp-1, eNOS, tPA and PAI-1 gene polymorphism and correlation of genotypes and phenotypes in hepatopulmonary syndrome

AIM

The aim of this case-control study was to investigate both the distribution of MCP-1, eNOS, tPA and PAI-1 gene polymorphism and correlation of genotypes and phenotypes.

METHOD

Between September 1997-January 2005, 20 patients with HPS (group 1) were compared with a group of cirrhotic patients (group 2, n = 19) as well as unrelated healthy controls (group 3, n = 59) in respect to MCP1, eNOS, tPA and PAI-1 gene polymorphism frequency distribution.

RESULTS

MCP1-2518G allele carriage in patients with HPS was higher than in controls (P = 0.01). In non-HPS cirrhotic patients, eNOS Glu298Asp, Asp gene carriers and frequency of Asp alleles were detected to be considerably higher than in patients with HPS and healthy controls (P < 0.05).

CONCLUSION

HPS is more common in patients with MCP-1 2518G gene carriage; conversely it is less frequent in patients with high frequency of eNOS 298Asp allele and eNOS 298Asp carriage.

Association of MCP-1 and CCR2 polymorphisms with the risk of late acute rejection after renal transplantation in Korean patients

Among the factors modulating transplant rejection, chemokines and their respective receptors deserve special attention. Increased expression of monocyte chemoattractant protein-1 (MCP-1) and its corresponding receptor (chemokine receptor-2, CCR2) has been implicated in renal transplant rejection. To determine the impact of the MCP-1-2518G and CCR2-64I genotypes on renal allograft function, 167 Korean patients who underwent transplantation over a 25-year period were evaluated. Genomic DNA was genotyped using polymerase chain reaction followed by restriction fragment length polymorphism analysis. Fifty-five (32.9%) patients were homozygous for the MCP-1-2518G polymorphism. Nine (5.4%) patients were homozygous for the CCR2-64I polymorphism. None of the investigated polymorphism showed a significant shift in long-term allograft survival. However, a significant increase was noted for the risk of late acute rejection in recipients who were homozygous for the MCP-1-2518G polymorphism (OR, 2.600; 95% CI, 1.125–6.012; P = 0.022). There was also an association between the MCP-1-2518G/G genotype and the number of late acute rejection episodes (P = 0.024). Although there was no difference in the incidence of rejection among recipients stratified by the CCR2-V64I genotype, recipients with the CCR2-V64I GG genotype in combination with the MCP-1-2518G/G genotype had a significantly higher risk of acute or late acute rejection among the receptor-ligand combinations (P = 0.006, P = 0.008, respectively). The MCP-1 variant may be a marker for risk of late acute rejection in Korean patients.

Asthma from a pharmacogenomic point of view

Pharmacogenomics, a fascinating, emerging area of biomedical research is strongly influenced by growing availability of genomic databases, high-throughput genomic technologies, bioinformatic tools and artificial computational modelling approaches. One main area of pharmacogenomics is the discovery of new drugs and drug targets with molecular genetic, genomic or even bioinformatic methods; the other is the study of how genomic differences influence the variability in patients' responses to drugs. From a genetic point of view, asthma is multifactorial, which means that the susceptibility to the disease is determined by interactions between multiple genes, and involves important non-genetic factors such as the environment for their expression. In this review, we summarize collective evidence from linkage and association studies that have consistently reported suggestive linkage or association of asthma or its associated phenotypes to polymorphic markers and single nucleotide polymorphisms in selected chromosomes. Genes that have been found implicated in the disease are potential new drug targets and several pharmacological investigations are underway to utilize these new discoveries. Next, we will focus on the inter-individual variability in anti-asthmatic drug responses and review the recent results in this topic.

The genetics of atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a complex genetic disorder influenced by environmental factors. The mode of inheritance and genes involved are not clear.

RESULTS

This report here is focusing on the current progress in searching the disease-susceptibility genes of AD via both the linkage studies and candidate gene approaches. Genome-wide linkage studies have identified multiple susceptibility loci on 3q and 17q. Candidate region linkage studies identify other susceptibility loci on 5q23-33, 11q13, and 13q12-14. At least 28 candidate genes have to date been verified in association studies, but only association with genes of interleukin (IL)-4, IL-13, IL-4RA, mast cell chymase, and serine protease inhibitor, kazal-type 5 have been replicated in more than two different studies. More halpotype tests and family-based association studies may help to shed more light for the candidate gene approach.

CONCLUSION

Determining the candidate susceptibility genes for AD is not only helping understanding the pathophysiology but also affecting the response to therapy, which is important in pharmacogenetics. The effect of environmental trigger may also have to be considered to elucidate the real face of the disease.

Environmental and genetic modifiers of the progression to fibrosis and cirrhosis in hemochromatosis

Hereditary hemochromatosis is a genetic disorder of iron metabolism leading to inappropriate iron absorption and iron loading in various organs especially the liver. Despite the genetic mutation being relatively common in those of Anglo Celtic descent, cirrhosis of the liver occurs in only a small proportion of affected individuals. The risk of hepatic fibrosis and cirrhosis relates to the degree of iron loading with threshold hepatic iron concentrations being identified from population studies. However, other environmental and possibly genetic factors appear to modify this risk. Excess alcohol consumption appears to be one of the most important cofactors with steatosis and coexistent viral infection also implicated. Genetic polymorphisms in genes associated with fibrogenesis, antioxidant activity, and inflammation have been investigated in several different forms of chronic liver disease. The variability in the expression of these genes that predispose patients with hemochromatosis to increased risk of severe liver disease is the subject of ongoing investigations. Clearly the progression of iron loading to cirrhosis marks a crucial stage in the natural history of a patient's disease and therefore therapy and prognosis. This review explores recent developments in knowledge of environmental and genetic modifiers of this process.

MCP-1/CCL2: a new diagnostic marker and therapeutic target for progressive renal injury in diabetic nephropathy

Despite current therapies, many diabetic patients will suffer from declining renal function in association with progressive kidney inflammation. Recently, animal model studies have demonstrated that kidney macrophage accumulation is a critical factor in the development of diabetic nephropathy. However, specific anti-inflammatory strategies are not yet being considered for the treatment of patients with diabetic renal injury. This review highlights the chemokine monocyte chemoattractant protein-1 (MCP-1)/CC-chemokine ligand 2 as a major promoter of inflammation, renal injury, and fibrosis in diabetic nephropathy. Researchers have found that diabetes induces kidney MCP-1 production and that urine MCP-1 levels can be used to assess renal inflammation in this disease. In addition, genetic deletion and molecular blocking studies in rodents have identified MCP-1 as an important therapeutic target for treating diabetic nephropathy. Evidence also suggests that a polymorphism in the human MCP-1 gene is associated with progressive kidney failure in type 2 diabetes, which may identify patients at higher risk who need additional therapy. These findings provide a strong rationale for developing specific therapies against MCP-1 and inflammation in diabetic nephropathy.

MCP-1 Promoter Polymorphism at 2518 is associated with metastasis of nasopharyngeal carcinoma after treatment

PURPOSE

We herein examined whether the single nucleotide polymorphism (SNP) at -2518 of the MCP-1 gene promoter region influences clinical outcomes among nasopharyngeal carcinoma (NPC) patients.

EXPERIMENTAL DESIGN

The study population consisted of 411 NPC patients without metastasis at diagnosis. All patients were treated at the Chang Gung Memorial Hospital from March 1994 to November 2004. The MCP-1 SNP-2518 genotype of each patient was determined by TaqMan genotyping kit. Statistical analyses were conducted to compare disease-specific survival (DSS), progression-free survival (PFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) of patients according to genotype. MCP-1 expression in tumor biopsies was examined by immunohistochemistry.

RESULTS

Among 411 NPC patients, carriers of AA and AG genotypes were prone to distant metastasis than that of GG genotype (hazard ratio, 2.21; P = 0.017, and hazard ratio, 2.23; P = 0.005, for AA and AG genotype, respectively) after initial radiotherapy. No genotype-specific significant difference was found in DSS, PFS, and LRFS. Furthermore, immunohistochemistry revealed that MCP-1 expression level was higher in NPC tumor cells from GG carriers compared with those from AA and AG carriers.

CONCLUSIONS

MCP-1 SNP-2518 may be a valuable genetic marker for assessing the risk of developing distant metastasis after the radiotherapy in NPC patients. Carriers of A allele may require more aggressive chemotherapy implicating a potential marker for personalized medicine. We speculate that a regulatory SNP may be associated with the distant metastasis of NPC. Validation studies are warranted.

Association between the -2518G/A polymorphism in the monocyte chemoattractant protein-1 (MCP-1) gene and myocardial infarction in Tunisian patients

BACKGROUND

Monocyte chemoattractant protein-1 (MCP-1; gene name CCL2) has been suggested to play an important role in the initiation of atherosclerosis by recruiting monocytes to sites of injured endothelium. Recently, single nucleotide polymorphisms (SNPs) in the MCP-1 regulatory region have been identified. Controversial results regarding the association of the -2518G/A polymorphism of the MCP-1 gene with coronary artery disease (CAD) have been reported. In the present study, we examined a possible association between the -2518G/A polymorphism of the MCP-1 gene and myocardial infarction (MI) in a sample of the Tunisian population.

METHODS

A total of 319 Tunisian patients with MI and 467 healthy controls were included in the study. The SNP of the MCP-1 gene was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.

RESULTS

Patients with MI had significantly higher frequency of the AG+GG genotypes compared to controls [42.9% vs. 35.8%; OR (95%CI), 1.34 (1.00-1.79); p=0.04]. The MI patient group showed a significant higher frequency of the G allele compared to the controls [0.242 vs. 0.195; OR (95%CI), 1.31(1.02-1.68), p=0.03]. The association between the -2518G/A polymorphism of the MCP-1 gene and MI was no longer significant after adjustment for other well-established risk factors.

CONCLUSION

The present study showed a significant but not independent association between the -2518G/A polymorphism of the MCP-1 gene (presence of G allele) and MI in the Tunisian population.

Genetic variability of major inflammatory mediators has no impact on the outcome of kidney transplantation

BACKGROUND

Functionally relevant polymorphisms in genes of the Th1 and Th2-inflammatory pathway influence the susceptibility to acute rejection (AR), chronic allograft nephropathy (CAN), and subclinical rejection (SR) as well as graft survival after renal transplantation. Because these findings have not been validated, we sought confirmatory evidence of these associations in a larger group of renal transplant recipients.

METHODS

A total of 436 kidney transplant recipients were genotyped for 9 single nucleotide polymorphisms (TNF-alpha-308G/A, MCP-1-2518A/G, RANTES-403G/A, -109T/C and -28C/G, CCR2+190G/A, IFN-gamma+874A/T, TGF-beta+869T/C and +915G/C) and for the 32-bp indel polymorphism in CCR5. The effects of these polymorphisms on the incidence of AR, SR, CAN and graft survival were analyzed in single locus and haplotype models.

RESULTS

Single locus analysis revealed that there was no significant difference in the distribution of the genotype frequencies between patients with and without AR, and between patients with CAN or SR, and individuals without CAN. Furthermore, no influence of any of the polymorphisms on the long-term graft survival was observed. Haplotype [TGF-beta +869G; TGF-beta +915C] seemed to be associated with the presence of SR (odds ratio: 3.45, 95% confidence interval: 1.19 - 9.99, P=0.023), but the association was nonsignificant due to the insufficient power.

CONCLUSION

In contrast to previous allelic association studies, neither of the polymorphisms has been associated with the outcome of kidney transplantation in the single locus analysis nor in the haplotype model. Our findings reinforce the need for more rigorous research compliant with the currently accepted standards for polymorphism-disease association studies.

Can CCL2 serum levels be used in risk stratification or to monitor treatment response in systemic sclerosis?

OBJECTIVE

The chemokine CCL2 has been consistently found to be up-regulated in systemic sclerosis. To explore the potential value of serum CCL2 measurement in disease assessment, we have compared CCL2 levels with clinical phenotype and investigated effect of therapy on circulating CCL2.

METHODS

Serum samples from a well characterised cohort of 94 systemic sclerosis (SSc) patients, 16 patients with primary Raynaud phenomenon and 11 healthy controls were examined by ELISA. Our cohort of patients included 50 patients with limited cutaneous (lc)SSc (20 with lcSSc alone and 30 with pulmonary arterial hypertension-lcSSc), and 44 with diffuse cutaneous (dc)SSc, 30 of which had early-onset dcSSc.

RESULTS

Serum levels of CCL2 were increased in both major SSc subsets. In early stage dcSSc 18/30 (60%) cases demonstrated markedly elevated CCL2, and this was associated with anti-topoisomerase or anti-RNA polymerase I/III antibody reactivity, and with greater frequency of major organ-based complications. Elevation of CCL2 serum levels in the lcSSc subset was not associated with pulmonary arterial hypertension, although there was a trend for reduction following treatment with prostacyclin analogues or bosentan.

CONCLUSION

These findings suggest that the CCL2/CCR2 axis is a potential therapeutic target in SSc, particularly in the early dcSSc subset. CCL2 measurement may be useful for risk stratification in early stage disease, but its value in disease monitoring is questionable.

The G(-2518)A polymorphism of monocyte chemotactic protein-1 (MCP-1) and its serum and peritoneal fluid levels in Korean women with endometriosis

OBJECTIVES

To investigate the associations between endometriosis and the G(-2518)A polymorphism of monocyte chemotactic protein-1 (MCP-1), and serum and peritoneal fluid MCP-1 levels in Korean women.

STUDY DESIGN

The G(-2518)A polymorphism of MCP-1 was analyzed by restriction fragment length polymorphism in 105 women with and in 101 women without endometriosis. Serum and peritoneal fluid MCP-1 levels were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The genotype frequencies of the MCP-1 G (-2518)A polymorphism were GG 36.9%, AG 52.9%, and AA 10.2%. MCP-1 genotype frequencies and serum and peritoneal fluid MCP-1 levels were similar in those with or without endometriosis and were not dependent on disease stage. A significant correlation was found between serum and peritoneal fluid levels of MCP-1. However, no differences were found between MCP-1 genotypes in terms of serum and peritoneal fluid MCP-1 levels.

CONCLUSIONS

Serum and peritoneal fluid MCP-1 levels and the G (-2518)A MCP-1 polymorphism were found not to be associated with endometriosis in Korean women.

Mycobacterium tuberculosis, macrophages, and the innate immune response: does common variation matter?

Despite the discovery of the tuberculosis (TB) bacillus over 100 years ago and the availability of effective drugs for over 50 years, there remain a number of formidable challenges for controlling Mycobacterium tuberculosis (MTb). Understanding the genetic and immunologic factors that influence human susceptibility could lead to novel insights for vaccine development as well as diagnostic advances to target treatment to those who are at risk for developing active disease. Although a series of studies over the past 50 years suggests that host genetics influences resistance to TB, a comprehensive understanding of which genes and variants are associated with susceptibility is only partially understood. In this article, we review recent advances in our understanding of human variation of the immune system and its effects on macrophage function and influence on MTb susceptibility. We emphasize recent discoveries in human genetic studies and correlate these findings with efforts to understand how these variants alter the molecular and cellular functions that regulate the macrophage response to MTb.

The chemokine network. II. On how polymorphisms and alternative splicing increase the number of molecular species and configure intricate patterns of disease susceptibility

In this second review on chemokines, we focus on the polymorphisms and alternative splicings and on their consequences in disease. Because chemokines are key mediators in the pathogenesis of inflammatory, autoimmune, vascular and neoplastic disorders, a large number of studies attempting to relate particular polymorphisms of chemokines to given diseases have already been conducted, sometimes with contradictory results. Reviewing the published data, it becomes evident that some chemokine genes that are polymorphic have alleles that are found repeatedly, associated with disease of different aetiologies but sharing some aspects of pathogenesis. Among CXC chemokines, single nucleotide polymorphisms (SNPs) in the CXCL8 and CXCL12 genes stand out, as they have alleles associated with many diseases such as asthma and human immunodeficiency virus (HIV), respectively. Of CC chemokines, the stronger associations occur among alleles from SNPs in CCL2 and CCL5 genes and a number of inflammatory conditions. To understand how chemokines contribute to disease it is also necessary to take into account all the isoforms resulting from differential splicing. The first part of this review deals with polymorphisms and the second with the diversity of molecular species derived from each chemokine gene due to alternative splicing phenomena. The number of molecular species and the level of expression of each of them for every chemokine and for each functionally related group of chemokines reaches a complexity that requires new modelling algorithms akin to those proposed in systems biology approaches.

MCP-1, RANTES, and SDF-1 polymorphisms in Mexican patients with systemic lupus erythematosus

Chemokines and cytokines play an important role in the inflammatory development and progression of autoimmune diseases. The aim of the present study was to evaluate the role of MCP-1, SDF-1, and RANTES polymorphisms as susceptibility markers for systemic lupus erythematosus (SLE) in a group of Mexican patients. MCP-1-2518, SDF-1 G801A, and RANTES-28 polymorphisms were determined in 242 patients with SLE and 220 ethnically matched healthy controls by the polymerase chain reaction-restriction fragment length polymorphism technique. The differences between patients and healthy controls were evaluated by chi(2), Fisher's exact test, and Woolf method for odds ratio. A moderately increased frequency of MCP-1-2518 A allele (p = 0.033, pC = NS) and AA genotype (p = 0.017, pC = NS) existed in SLE patients compared with healthy controls. There was a relationship between polymorphisms and some clinical and laboratory characteristics. SLE patients with and without antiphospholipid syndrome demonstrated different distribution of SDF-1 G801A genotype frequencies. On the other hand, patients with leukopenia, anti-dsDNA, and antiphospholipid autoantibodies demonstrated different MCP-1-2518 genotype distribution compared with patients without these features. Our results suggest that MCP-1 polymorphism is moderately associated with the genetic susceptibility to SLE in Mexican individuals. The polymorphisms could be related to specific clinical and laboratory characteristics in these patients.

Monocyte chemoattractant protein-1 promoter -2518 polymorphism is associated with post-challenge insulin and glucose levels in non-diabetic Japanese subjects

We investigated that the association of MCP-1 polymorphism at position -2518 with insulin sensitivity and insulin secretion by measuring the fasting and post-challenge glucose and insulin levels during 75g OGTT in 409 non-diabetic Japanese subjects. The blood sampling was performed before glucose loading and after 30 and 120 min. Polymorphism was evaluated by PCR-RFLP method by genomic DNA isolated from peripheral blood leukocytes. The genotype distribution was 44.8% for G/G, 46.0% for G/A and 9.2% for A/A. The plasma glucose levels were significantly increased in A/A as compared to G/G (p<0.05), but it was not compared with G/A at 120 min. The serum insulin levels were significantly increased in A/A as compared to G/A (p<0.05) or G/G (p<0.05) at 30 min. Moreover, the serum insulin levels in A/A were significantly increased compared with G/A (p<0.02) or G/G (p<0.005) at 120 min. Elevation in post-challenge glucose (120 min) and insulin levels (30 and 120 min) suggests that reduced insulin sensitivity during glucose loading occurs in subjects with A/A polymorphism. The present study demonstrates that the A/A polymorphism of the MCP-1 gene at position -2518 is associated with insulin resistance during glucose loading in non-diabetic Japanese subjects.

Risk of carotid atherosclerosis associated with genetic polymorphisms of apolipoprotein E and inflammatory genes among arsenic exposed residents in Taiwan

Arsenic had been reported to be associated with carotid atherosclerosis. However, there were few studies to evaluate the association between the susceptible gene of lipid metabolism and inflammation and carotid atherosclerosis among arsenic exposure residents. The aim of the study was to investigate the associations between the genetic polymorphisms of APOE and MCP-1 and the risk of carotid atherosclerosis among residents of Lanyang Basin in Taiwan which was a newly confirmed arsenic-endemic area. In total, 479 residents who had been genotyped of these two genes and examined the severity of carotid atherosclerosis were included in this study. The study subjects with carotid intima media thickness (IMT) >or=1.0 mm or with the observable plaque in the extracranial carotid artery were diagnosed as carotid atherosclerosis. A significantly age- and gender-adjusted odds ratio of 2.0 for the development of carotid atherosclerosis was observed in study subjects with epsilon4 allele of APOE than those without epsilon4 allele. Compared with study subjects who carried wild genotypes of APOE and MCP-1, those with both risk genotypes of APOE and MCP-1 had 2.5-fold risk of carotid atherosclerosis after adjustment for age and gender, revealing a significant dose-response relationship between number of risk genotypes of these genes and risk of carotid atherosclerosis. Additionally, study subjects with two risk genotypes of APOE and MCP-1 and either had ingested well water contained arsenic level >10 microg/L or had arsenic exposure >0.22 mg/L-year would have strikingly highest risk of 10.3-fold and 15.7-fold, respectively, for the development carotid atherosclerosis, showing significant joint effect of arsenic exposure and risk genotypes of APOE and MCP-1.