ACP1 and Th Class of Immunological Disease: Evidence of Interaction with Gender

Systematic review reveals multiple sexually antagonistic polymorphisms affecting human disease and complex traits

An evolutionary model for sex differences in disease risk posits that alleles conferring higher risk in one sex may be protective in the other. These sexually antagonistic (SA) alleles are predicted to be maintained at frequencies higher than expected under purifying selection against unconditionally deleterious alleles, but there are apparently no examples in humans. Discipline-specific terminology, rather than a genuine lack of such alleles, could explain this disparity. We undertook a two-stage review of evidence for SA polymorphisms in humans using search terms from (i) evolutionary biology and (ii) biomedicine. Although the first stage returned no eligible studies, the second revealed 51 genes with sex-opposite effects; 22 increased disease risk or severity in one sex but protected the other. Those with net positive effects occurred at higher frequencies. None were referred to as SA. Our review reveals significant communication barriers to fields as a result of discipline-specific terminology.

The role of phospho-tyrosine signaling in platelet biology and hemostasis

Platelets are small enucleated cell fragments specialized in the control of hemostasis, but also playing a role in angiogenesis, inflammation and immunity. This plasticity demands a broad range of physiological processes. Platelet functions are mediated through a variety of receptors, the concerted action of which must be tightly regulated, in order to allow specific and timely responses to different stimuli. Protein phosphorylation is one of the main key regulatory mechanisms by which extracellular signals are conveyed. Despite the importance of platelets in health and disease, the molecular pathways underlying the activation of these cells are still under investigation. Here, we review current literature on signaling platelet biology and in particular emphasize the newly emerging role of phosphatases in these processes.

Modulation of TCR Signaling by Tyrosine Phosphatases: From Autoimmunity to Immunotherapy

Early TCR signaling is dependent on rapid phosphorylation and dephosphorylation of multiple signaling and adaptor proteins, leading to T cell activation. This process is tightly regulated by an intricate web of interactions between kinases and phosphatases. A number of tyrosine phosphatases have been shown to modulate T cell responses and thus alter T cell fate by negatively regulating early TCR signaling. Mutations in some of these enzymes are associated with enhanced predisposition to autoimmunity in humans, and mouse models deficient in orthologous genes often show T cell hyper-activation. Therefore, phosphatases are emerging as potential targets in situations where it is desirable to enhance T cell responses, such as immune responses to tumors. In this review, we summarize the current knowledge about tyrosine phosphatases that regulate early TCR signaling and discuss their involvement in autoimmunity and their potential as targets for tumor immunotherapy.

Regulation of CD4+ T Cell Signaling and Immunological Synapse by Protein Tyrosine Phosphatases: Molecular Mechanisms in Autoimmunity

T cell activation and effector function is mediated by the formation of a long-lasting interaction established between T cells and antigen-presenting cells (APCs) called immunological synapse (IS). During T cell activation, different signaling molecules as well as the cytoskeleton and the endosomal compartment are polarized to the IS. This molecular dynamics is tightly regulated by phosphorylation networks, which are controlled by protein tyrosine phosphatases (PTPs). While some PTPs are known to be important regulators of adhesion, ligand discrimination or the stimulation threshold, there is still little information about the regulatory role of PTPs in cytoskeleton rearrangements and endosomal compartment dynamics. Besides, spatial and temporal regulation of PTPs and substrates at the IS is only barely known. Consistent with an important role of PTPs in T cell activation, multiple mutations as well as altered expression levels or dynamic behaviors have been associated with autoimmune diseases. However, the precise mechanism for the regulation of T cell activation and effector function by PTPs in health and autoimmunity is not fully understood. Herein, we review the current knowledge about the regulatory role of PTPs in CD4⁺ T cell activation, IS assembly and effector function. The potential molecular mechanisms mediating the action of these enzymes in autoimmune disorders are discussed.

Association between phosphatase related gene variants and coronary artery disease: case-control study and meta-analysis

Recent studies showed that the serum alkaline phosphatase is an independent predictor of the coronary artery disease (CAD). In this work, we aimed to summarize the association between three phosphatase related single nucleotide polymorphisms (rs12526453, rs11066301 and rs3828329) and the risk of CAD in Han Chinese. Our results showed that the rs3828329 of the ACP1 gene was closely related to the risk of CAD in Han Chinese (OR = 1.45, p = 0.0006). This significant association of rs3828329 with CAD was only found in the females (Additive model: OR = 1.80, p = 0.001; dominant model: OR = 1.69, p = 0.03; recessive model: OR = 1.96, p = 0.0008). Moreover, rs3828329 was likely to exert its effect in females aged 65 years and older (OR = 2.27, p = 0.001). Further meta-analyses showed that the rs12526453 of PHACTR11 gene (OR = 1.14, p < 0.0001, random-effect method) and the rs11066301 of PTPN11 gene (OR = 1.15, p < 0.0001, fixed-effects method) were associated with CAD risk in multiple populations. Our results showed that the polymorphisms rs12526453 and rs11066301 are significantly associated with the CAD risk in multiple populations. The rs3828329 of ACP1 gene is also a risk factor of CAD in Han Chinese females aged 65 years and older.

Gender differences in autoimmune disease

Autoimmune diseases are a range of diseases in which the immune response to self-antigens results in damage or dysfunction of tissues. Autoimmune diseases can be systemic or can affect specific organs or body systems. For most autoimmune diseases there is a clear sex difference in prevalence, whereby females are generally more frequently affected than males. In this review, we consider gender differences in systemic and organ-specific autoimmune diseases, and we summarize human data that outlines the prevalence of common autoimmune diseases specific to adult males and females in countries commonly surveyed. We discuss possible mechanisms for sex specific differences including gender differences in immune response and organ vulnerability, reproductive capacity including pregnancy, sex hormones, genetic predisposition, parental inheritance, and epigenetics. Evidence demonstrates that gender has a significant influence on the development of autoimmune disease. Thus, considerations of gender should be at the forefront of all studies that attempt to define mechanisms that underpin autoimmune disease.

Regulation of TCR signalling by tyrosine phosphatases: from immune homeostasis to autoimmunity

More than half of the known protein tyrosine phosphatases (PTPs) in the human genome are expressed in T cells, and significant progress has been made in elucidating the biology of these enzymes in T-cell development and function. Here we provide a systematic review of the current understanding of the roles of PTPs in T-cell activation, providing insight into their mechanisms of action and regulation in T-cell receptor signalling, the phenotypes of their genetically modified mice, and their possible involvement in T-cell-mediated autoimmune disease. Our projection is that the interest in PTPs as mediators of T-cell homeostasis will continue to rise with further functional analysis of these proteins, and PTPs will be increasingly considered as targets of immunomodulatory therapies.

Relation between objective measures of atopy and myocardial infarction in the United States

BACKGROUND

Although rodent studies indicate that atherosclerosis is a T(H)1-mediated disease and that atopic T(H)2 immunity is atheroprotective, findings in humans are conflicting. Total IgE (tIgE) is associated with atherosclerotic disease but has limited specificity for atopy.

OBJECTIVE

Our aim was to determine the relation between atopy, as indicated by a broad panel of serum allergen-specific IgE (sIgE), and past myocardial infarction (MI) in a sample representative of the US population.

METHODS

Data were analyzed from 4002 participants aged ≥ 20 years from the 2005-2006 National Health and Nutrition Examination Survey.

RESULTS

Subjects reporting a history of MI had lower summed sIgE (5.51 vs 7.71 kU/L; P < .001) and were less likely to have ≥ 1 positive sIgE test (29.9% vs 44.6%; P = .02) or current hay fever (3.3% vs 7.6%; P = .002). After adjustment for age, sex, race/ethnicity, diabetes mellitus, hypertension, family history of MI, smoking, total/high-density lipoprotein cholesterol, body mass index, and C-reactive protein, the odds ratio (OR) for MI was 0.91 (95% CI, 0.85-0.97) per positive sIgE; 0.70 (95% CI, 0.57-0.85) per 2-fold increase in sum[sIgE]; and 0.82 (95% CI, 0.69-0.98) per 10% increase in the ratio of sum[sIgE] to tIgE. Analysis with 7 data-driven, prespecified allergen clusters found that house dust mite is the only allergen cluster for which sIgE is associated with reduced odds for MI (fully adjusted OR, 0.36; 95% CI, 0.20-0.64).

CONCLUSION

Serum sIgE is inversely related to MI in the US population in a manner independent of multiple coronary risk factors.

Lack of association of ACP1 gene with inflammatory bowel disease: a case-control study

The red cell acid phosphatease (ACP1) gene, which encodes a low molecular weight phosphotyrosine phosphatase (LMW-PTP), has been suggested as a common genetic factor of autoimmunity. In the present study, we aimed to investigate the possible influence of ACP1 polymorphisms in the susceptibility of inflammatory bowel disease (IBD). A total of 1271 IBD Spanish patients [720 Crohn's disease (CD) and 551 ulcerative colitis (UC)] and 1877 healthy subjects were included. Four single-nucleotide polymorphisms (SNPs), rs10167992, rs11553742, rs7576247 and rs3828329, were genotyped using TaqMan SNP genotyping assays. Common ACP1 alleles (i.e. ACP1*A, ACP1*B and ACP1*C) were determined by two of these SNPs. After the analysis, no evidence of association of the ACP1 genetic variants was found with CD or UC. Therefore, our results suggest that the ACP1 gene may not play a relevant role in the development of IBD.

Mucosal healing predicts late outcomes after the first course of corticosteroids for newly diagnosed ulcerative colitis

BACKGROUND & AIMS

It is uncertain whether mucosal healing after the first course of corticosteroids therapy predicts outcome in patients with ulcerative colitis (UC). We evaluated whether early clinical and endoscopic responses to this therapy are associated with late outcomes in UC.

METHODS

Patients with newly diagnosed UC who were prescribed corticosteroid therapy (n = 157) were followed up for 5 years. They were evaluated using clinical (Powel-Tuck [PT]) and endoscopic (Baron) indexes after 3 and 6 months, then every 6 months. Outcomes at month 3 (early response) were used to identify patients with complete (group A: PT, 0-1; Baron, 0), partial (group B: PT, 0-1; Baron, 1-3), or no response (group C: persistence of clinical and endoscopic activity). The association between early and late outcomes was assessed.

RESULTS

After 5 years, there were significant differences between complete and partial responders in the rates of hospitalization (25% in group A vs 48.7% in group B; P = .0152; odds ratio [OR], 2.85; 95% confidence interval [CI], 1.21-6.72), immunosuppression therapy (5% in group A vs 25.6% in group B; P = .0030; OR, 6.55; 95% CI, 1.67-25.67), colectomy (3.3% in group A vs 18.0% in group B; P = .0265; OR, 6.34; 95% CI, 1.24-32.37), and their combination (26.7% in group A vs 48.7% in group B; P = .0249; OR, 2.61; 95% CI, 1.12-6.11). After multivariate analysis, lack of mucosal healing was the only factor associated with negative outcomes at 5 years (immunosuppressors: hazard risk [HR], 10.581; 95% CI, 2.193-51.039; P = .0033; hospitalization: HR, 3.634; 95% CI, 1.556-8.485; P = .0029; colectomy: HR, 8.397; 95% CI, 1.278-55.186; P = .0268).

CONCLUSIONS

No mucosal healing after corticosteroid therapy is associated with a more aggressive disease course.

Evidence for sex-specific associations between variation in acid phosphatase locus 1 (ACP1) and insulin sensitivity in Mexican-Americans

CONTEXT

Acid phosphatase locus 1 (ACP1) is a low molecular weight tyrosine phosphatase that has been shown to be an important regulator of insulin receptor signaling.

OBJECTIVE

We tested whether variation in ACP1 is associated with type 2 diabetes-related traits in 1035 individuals in 339 Mexican-American families of probands with or without a previous diagnosis of gestational diabetes mellitus (GDM).

DESIGN

Study participants were phenotyped by oral glucose tolerance test (for glucose and insulin level) and iv glucose tolerance test (for insulin sensitivity and acute insulin response) and had dual-energy x-ray absorptiometry scans to assess body composition. Six tag single nucleotide polymorphisms (SNPs) were identified from among 15 SNPs genotyped across the ACP1 region. SNPs were tested for association with phenotypes using a likelihood ratio test under a variance components framework.

RESULTS

After Bonferroni correction, none of the SNPs were associated with type 2 diabetes mellitus-related phenotypes. However, we observed a significant sex-specific effect of rs3828329. Among males, rs3828329 was significantly associated with fasting insulin (Bonferroni P = 0.007) and insulin sensitivity (Bonferroni P = 0.019) and marginally associated with 2-h insulin (Bonferroni P = 0.058) and percentage body fat (Bonferroni P = 0.09).

CONCLUSIONS

There were no significant associations in females. We conclude that variation in ACP1 is associated with fasting insulin and insulin sensitivity in a sex-specific manner.