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Matthias Wahle

Publications and source records attributed to Matthias Wahle.

7 recordsLinked to original sources
PubMed2006

Association of PTPN22 1858 single-nucleotide polymorphism with rheumatoid arthritis in a German cohort: higher frequency of the risk allele in male compared to female patients.

The functional single-nucleotide polymorphism (SNP) of the gene PTPN22 is a susceptibility locus for rheumatoid arthritis (RA). The study presented here describes the association of the PTPN22 1858T allele with RA in a German patient cohort; 390 patients with RA and 349 controls were enrolled in the study. For 123 patients, clinical and radiographic documentation over 6 years was available from the onset of disease. Genotyping of the PTPN22 1858 SNP was performed using an restriction fragment length polymorphism PCR-based genotyping assay. The odds ratio to develop RA was 2.57 for carriers of the PTPN22 1858T allele (95% confidence interval (CI) 1.85-3.58, p < 0.001), and 5.58 for homozygotes (95% CI 1.85-16.79). The PTPN22 1858T allele was significantly associated not only with rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) positive RA, but also with RF and anti-CCP negative disease. The frequency of the PTPN22 1858T allele was increased disproportionately in male patients (53.8% compared to 33.0% in female patients, p < 0.001), and the resulting odds ratio for male carriers was increased to 4.47 (95% CI 2.5-8.0, p < 0.001). Moreover, within the male patient population, the rare allele was significantly associated with the HLA-DRB1 shared epitope (p = 0.01). No significant differences in disease activity or Larsen scores were detected. The results provide further evidence that the PTPN22 1858T allele is associated with RA irrespective of autoantibody production. The increased frequency of the risk allele in male patients and its association with the shared epitope indicate that the genetic contribution to disease pathogenesis might be more prominent in men.

Arthritis, Rheumatoid↗
PubMed2006

Failure of catecholamines to shift T-cell cytokine responses toward a Th2 profile in patients with rheumatoid arthritis.

To further understand the role of neuro-immunological interactions in the pathogenesis of rheumatoid arthritis (RA), we studied the influence of sympathetic neurotransmitters on cytokine production of T cells in patients with RA. T cells were isolated from peripheral blood of RA patients or healthy donors (HDs), and stimulated via CD3 and CD28. Co-incubation was carried out with epinephrine or norepinephrine in concentrations ranging from 10(-5) M to 10(-11) M. Interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha, interleukin (IL)-4, and IL-10 were determined in the culture supernatant with enzyme-linked immunosorbent assay. In addition, IFN-gamma and IL-10 were evaluated with intracellular cytokine staining. Furthermore, basal and agonist-induced cAMP levels and catecholamine-induced apoptosis of T cells were measured. Catecholamines inhibited the synthesis of IFN-gamma, TNF-alpha, and IL-10 at a concentration of 10(-5) M. In addition, IFN-gamma release was suppressed by 10(-7) M epinephrine. Lower catecholamine concentrations exerted no significant effect. A reduced IL-4 production upon co-incubation with 10(-5) M epinephrine was observed in RA patients only. The inhibitory effect of catecholamines on IFN-gamma production was lower in RA patients as compared with HDs. In RA patients, a catecholamine-induced shift toward a Th2 (type 2) polarised cytokine profile was abrogated. Evaluation of intracellular cytokines revealed that CD8-positive T cells were accountable for the impaired catecholaminergic control of IFN-gamma production. The highly significant negative correlation between age and catecholamine effects in HDs was not found in RA patients. Basal and stimulated cAMP levels in T-cell subsets and catecholamine-induced apoptosis did not differ between RA patients and HDs. RA patients demonstrate an impaired inhibitory effect of catecholamines on IFN-gamma production together with a failure to induce a shift of T-cell cytokine responses toward a Th2-like profile. Such an unfavorable situation is a perpetuating factor for inflammation.

Adult↗
PubMed2006

Sequence variants of the CRH 5'-flanking region: effects on DNA-protein interactions studied by EMSA in PC12 cells.

Recently, studies in adult rheumatoid arthritis patients have shown an association with four single-nucleotide polymorphisms (SNPs) in the 3.7-kb regulatory region of human corticotropin-releasing hormone (hCRH) gene located at positions -3531, -3371, -2353, and -684 bp. Three of these novel polymorphisms are in absolute linkage disequilibrium, resulting in three combined alleles, named A1B1, A2B1, and A2B2. To study whether the described polymorphic nucleotide sequences in the 5' region of the hCRH gene interfere with binding of nuclear proteins, an electric mobility shift assay (EMSA) was performed. At position -2353 bp, a specific DNA protein complex was detected for the wild-type sequence only, possibly interfering with a binding site for the activating transcription factor 6 (ATF6). In contrast, no difference could be detected for the other SNPs. However, at position -684, a quantitative difference in protein binding due to cAMP incubation could be observed. To further investigate whether these SNPs in the CRH promoter are associated with an altered regulation of the CRH gene, we performed a luciferase reporter gene assay with transiently transfected rat pheochromocytoma cells PC12. Incubation with 8-Br-cAMP alone or in combination with cytokines enhanced significantly the promoter activity in PC12 cells. The promoter haplotypes studied exhibited a differential capacity to modulate CRH gene expression. In all our experiments, haplotype A1B1 showed the most pronounced influence on promoter activity. Taken together, our results demonstrate a differential binding capacity of nuclear proteins of the promoter polymorphisms resulting in a different gene regulation. Most probably the SNP at position -2,353 plays a major role in mediating these differences.

5' Flanking Region↗
PubMed2005

Influence of catecholamines on cytokine production and expression of adhesion molecules of human neutrophils in vitro.

The impact of catecholamines on cytokine production and expression of adhesion molecules by human neutrophils was evaluated in vitro. Neutrophils were separated from venous blood of healthy subjects. The generation of intracellular cyclic adenosine monophosphate (cAMP) and Ca2+ was determined after incubation with catecholamines. Resting and lipopolysaccharide (LPS)-activated neutrophils were tested for synthesis of interleukins (IL-6, IL-8) and tumor necrosis factor alpha (TNF-alpha). In addition, the expression of the adhesion molecules CD15, CD44, and CD54 was evaluated in resting and activated neutrophils. Increasing concentrations (1 nM-1 mM) of epinephrine (EPI) were used to study the influence of activation of beta2-adrenergic receptors (beta2R) on cytokine production and adhesion molecule expression. Incubation with catecholamines induced an increase in cAMP but not Ca2+ in neutrophils. Only IL-8 was detected following stimulation with LPS and was unchanged upon co-incubation with EPI. The expression of CD15 and CD44 decreased spontaneously in vitro. The density of CD44 increased in the presence of very high doses of EPI (1 mM). Expression of CD54 on resting neutrophils increased upon activation. The density of CD54 on activated neutrophils was reduced upon co-incubation with 1 mM EPI for 6 h. However, 1 mM EPI for 12 and 18 h decreased the spontaneous loss of CD54 on resting neutrophils. Beta2R are functionally coupled to signalling cascades in human neutrophils. Nevertheless, the impact of catecholamines on IL-8 synthesis and expression of CD15, CD44, and CD54 is limited.

Antigens, CD↗
PubMed2005

Autonomic dysfunction in rheumatic diseases.

Patients who have rheumatic diseases often present with dysfunctions that are related to the autonomic nervous system (ANS) and are due to peripheral autonomic neuropathy or central changes. This article describes the prevalence of autonomic dysfunctions in patients who have rheumatic diseases. In the second part of this article, another form of ANS dysfunction-complex regional pain syndromes-is demonstrated. Clinically, these syndromes are characterized by pain (spontaneous, hyperalgesia, allodynia); active movement disorders, including an increased physiologic tremor, abnormal regulation of blood flow and sweating, edema of skin and subcutaneous tissues; and trophic changes of skin, appendages of skin, and subcutaneous tissues. In conclusion, this discussion shows that alterations of the ANS occur in rheumatic and related diseases, that these alterations may be involved in the pathogenesis of these diseases, and that we need more refined methods to study the changes that are related to the ANS.

Autonomic Dysreflexia↗
PubMed2004

Ex vivo homeostatic proliferation of CD4+ T cells in rheumatoid arthritis is dysregulated and driven by membrane-anchored TNFalpha.

The systemic CD4(+) T cell compartment in patients with rheumatoid arthritis (RA) is characterized by TCR repertoire contraction, shortened telomere lengths, and decreased numbers of recent thymic emigrants, suggesting a disturbed CD4(+) T cell homeostasis. In mice, homeostatic proliferation of peripheral CD4(+) T cells is regulated by TCR interaction with self peptide-MHC complexes (pMHC) and can be reproduced in vitro. We have established an ex vivo model of homeostatic proliferation, in which self-replication of human CD4(+) T cells is induced by cell-cell contact with autologous monocytes. In healthy individuals, blockade of TCR-pMHC class II contact resulted in decreased CD4(+) T cell division. In contrast, homeostatic proliferation in RA patients was not inhibited by pMHC blockade, but increased during the initial culture period. The anti-TNF-alpha Ab cA2 inhibited homeostasis-driven ex vivo proliferation in healthy controls and in RA patients. In addition, treatment of RA patients with infliximab decreased the ex vivo rate of homeostatic proliferation of CD4(+) T cells. Our results suggest a disturbed regulation of CD4(+) T cell homeostasis leading to the repertoire aberrations reported in RA. Membrane-anchored TNF-alpha appears to be a cell-cell contact-dependent stimulus of homeostatic proliferation of CD4(+) T cells, possibly favoring self-replication of autoreactive CD4(+) T cells in patients with RA.

Adult↗