Serum levels of vasoactive intestinal peptide as a prognostic marker in early arthritis

VIP/VPAC Axis Expression in Immune-Mediated Inflammatory Disorders: Associated miRNA Signatures

Few studies have considered immune-mediated inflammatory disorders (IMID) together, which is necessary to adequately understand them given they share common mechanisms. Our goal was to investigate the expression of vasoactive intestinal peptide (VIP) and its receptors VPAC1 and VPAC2 in selected IMID, analyze the effect of biological therapies on them, and identify miRNA signatures associated with their expression. Serum VIP levels and mRNA of VPAC and miRNA expression in peripheral blood mononuclear cells were analyzed from 52 patients with psoriasis, rheumatoid arthritis, Graves’ disease, or spondyloarthritis and from 38 healthy subjects. IMID patients showed higher levels of VIP and increased expression of VPAC2 compared to controls (p < 0.0001 and p < 0.0192, respectively). Receiver operating characteristic curve analysis showed that the levels of VIP or VPAC2 expression were adequate discriminators capable of identifying IMID. Treatment of IMID patients with anti-TNFα and anti-IL12/23 significantly affected serum VIP levels. We identified miRNA signatures associated with levels of serum VIP and VPAC2 expression, which correlated with IMID diagnosis of the patients. The results indicate that the expression of VIP/VPAC2 is able of identify IMIDs and open up a line of research based on the association between the VIP/VPAC axis and miRNA signatures in immune-mediated diseases.

Efficacy, safety and cost-effectiveness of methotrexate, adalimumab or their combination in non-infectious non-anterior uveitis: a protocol for a multicentre, randomised, parallel three arms, active-controlled, phase III open label with blinded outcome assessment study

INTRODUCTION

Non-infectious uveitis include a heterogeneous group of sight-threatening and incapacitating conditions. Their correct management sometimes requires the use of immunosuppressive drugs (ISDs), prescribed in monotherapy or in combination. Several observational studies showed that the use of ISDs in combination could be more effective than and as safe as their use in monotherapy. However, a direct comparison between these two treatment strategies has not been carried out yet.

METHODS AND ANALYSIS

The Combination THerapy with mEthotrexate and adalImumAb for uveitis (CoTHEIA) study is a phase III, multicentre, prospective, randomised, single-blinded with masked outcome assessment, parallel three arms with 1:1:1 allocation, active-controlled, superiority study design, comparing the efficacy, safety and cost-effectiveness of methotrexate, adalimumab or their combination in non-infectious non-anterior uveitis. We aim to recruit 192 subjects. The duration of the treatment and follow-up will last up to 52 weeks, plus 70 days follow-up with no treatment. The complete and maintained resolution of the ocular inflammation will be assessed by masked evaluators (primary outcome). In addition to other secondary measurements of efficacy (quality of life, visual acuity and costs) and safety, we will identify subjects' subgroups with different treatment responses by developing prediction models based on machine learning techniques using genetic and proteomic biomarkers.

ETHICS AND DISSEMINATION

The protocol, annexes and informed consent forms were approved by the Reference Clinical Research Ethic Committee at the Hospital Clínico San Carlos (Madrid, Spain) and the Spanish Agency for Medicines and Health Products. We will elaborate a dissemination plan including production of materials adapted to several formats to communicate the clinical trial progress and findings to a broad group of stakeholders. The promoter will be the only access to the participant-level data, although it can be shared within the legal situation.

TRIAL REGISTRATION NUMBER

2020-000130-18; NCT04798755.

The Neuropeptide VIP Limits Human Osteoclastogenesis: Clinical Associations with Bone Metabolism Markers in Patients with Early Arthritis

We aimed to evaluate the direct action of VIP on crucial molecules involved in human osteoclast differentiation and function. We also investigated the relationship between VIP serum levels and bone remodeling mediators in early arthritis patients. The expression of VIP receptors and osteoclast gene markers in monocytes and in vitro differentiated osteoclasts was studied by real-time PCR. NFATc1 activity was measured using a TransAM^® kit. Osteoclastogenesis was confirmed by quantification of tartrate-resistant acid phosphatase positive multinucleated cells. OsteoAssay^® Surface Multiple Well Plate was used to evaluate bone-resorbing activity. The ring-shaped actin cytoskeleton and the VPAC1 and VPAC2 expression were analyzed by immunofluorescence. We described the presence of VIP receptors in monocytes and mature osteoclasts. Osteoclasts that formed in the presence of VIP showed a decreased expression of osteoclast differentiation gene markers and proteolytic enzymes involved in bone resorption. VIP reduced the resorption activity and decreased both β3 integrin expression and actin ring formation. Elevated serum VIP levels in early arthritis patients were associated with lower BMD loss and higher serum OPG concentration. These results demonstrate that VIP exerts an anti-osteoclastogenic action impairing both differentiation and resorption activity mainly through the negative regulation of NFATc1, evidencing its bone-protective effects in humans.

Significance of serum VIP and PACAP in multiple sclerosis: an exploratory case-control study

BACKGROUND

Multiple sclerosis (MS) is a chronic inflammatory neurodegenerative disease of the central nervous system. Vasoactive and intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP) are neuropeptides that play roles in anti-inflammation and neuroprotection in MS. In this study, we aimed to determine the serum levels of VIP and PACAP in MS patients versus healthy controls and to correlate them with demographics and clinical characteristics.

METHODS

Serum samples were collected from MS patients (n = 145) and healthy controls (n = 73) to measure serum levels VIP and PACAP.

RESULTS

VIP serum levels were lower in MS patients than healthy controls (p < 0.001). Serum PACAP levels were the same among the two groups. Gender-based analysis showed that VIP levels were lower in healthy females (1238.840 pg/ml) than healthy males (3300.105 pg/ml; p < 0.001), and PACAP serum levels were significantly lower in male MS patients (48,516.214 fg/ml) than female MS patients (62,466.400 fg/ml; p = 0.029). ROC curve suggested that serum VIP level can discriminate patients with MS from healthy controls. Relapsing-remitting MS, progressive-MS, and clinically isolated syndrome groups were different in age, MS disease duration, EDSS score, and VIP levels (p < 0.05). MS disease type and history of previous relapses in the preceding 24 months predicted serum VIP levels, while gender predicted PACAP levels.

CONCLUSION

VIP serum levels are decreased in MS patients and can be used to differentiate between MS patients and healthy controls. Further studies with larger sample sizes are required to investigate VIP as a marker to reflect MS disease progression.

Factors Associated with Health-Related Quality of Life in Psoriatic Arthritis Patients: A Longitudinal Analysis

INTRODUCTION

Psoriatic arthritis (PsA) is considered a multifaceted disease, with patients reporting low health-related quality of life (HRQoL). Data on disease burden are substantial and there exists a need for properly designed studies to learn more about the evolution of HRQoL in this condition. This study aims to identify factors associated to HRQoL evolution in PsA patients followed-up in a real-world setting in Spain.

METHODS

We conducted a retrospective longitudinal observational study including incident patients from the rheumatology outpatient clinic of Hospital Clínico San Carlos (Madrid, Spain), diagnosed for the first time of PsA, defined as having received any ICD9/ICD10 diagnosis code of PsA, from 2007 to 2016, and followed-up until loss of follow-up, death, or November 2017. The influence of demographic and clinical variables in baseline HRQoL [assessed with the Rosser Classification Index (RCI)] was analyzed using bivariable and multivariable generalized linear models. The influence of those variables and of treatment-related factors in repeated measures of HRQoL was analyzed using bivariable and multivariable generalized estimating equations (GEE) models nested by patient.

RESULTS

Two hundred and thirty patients were included in the analysis, with 3384 registered visits. At baseline, older age, a previous diagnosis of obesity, and the presence of enthesitis were significantly associated with worse HRQoL. During follow-up, using an exchangeable working correlation structure, the presence of enthesitis was also associated with worse HRQoL, coefficient (95% CI) - 0.006 (- 0.01 to - 0.002), p = 1.00E-03; conversely, treatment with methotrexate or antimalarials was associated with better HRQoL with 0.007 (0.001-0.014), p = 0.020 and 0.003 (0.001-0.005), p = 3.00E-03, respectively.

CONCLUSIONS

Musculoskeletal manifestations and comorbidities exert a deleterious effect in HRQoL of PsA patients. Therefore, the optimal management of this condition needs to also address these manifestations in order to try to restore the QoL of these patients.

Proteomic Analysis of Synovial Fibroblasts and Articular Chondrocytes Co-Cultures Reveals Valuable VIP-Modulated Inflammatory and Degradative Proteins in Osteoarthritis

Osteoarthritis (OA) is the most common musculoskeletal disorder causing a great disability and a reduction in the quality of life. In OA, articular chondrocytes (AC) and synovial fibroblasts (SF) release innate-derived immune mediators that initiate and perpetuate inflammation, inducing cartilage extracellular matrix (ECM) degradation. Given the lack of therapies for the treatment of OA, in this study, we explore biomarkers that enable the development of new therapeutical approaches. We analyze the set of secreted proteins in AC and SF co-cultures by stable isotope labeling with amino acids (SILAC). We describe, for the first time, 115 proteins detected in SF-AC co-cultures stimulated by fibronectin fragments (Fn-fs). We also study the role of the vasoactive intestinal peptide (VIP) in this secretome, providing new proteins involved in the main events of OA, confirmed by ELISA and multiplex analyses. VIP decreases proteins involved in the inflammatory process (CHI3L1, PTX3), complement activation (C1r, C3), and cartilage ECM degradation (DCN, CTSB and MMP2), key events in the initiation and progression of OA. Our results support the anti-inflammatory and anti-catabolic properties of VIP in rheumatic diseases and provide potential new targets for OA treatment.

Comparative Study of Senescent Th Biomarkers in Healthy Donors and Early Arthritis Patients. Analysis of VPAC Receptors and Their Influence

Pro-inflammatory CD4⁺CD28⁻ T cells are characteristic of immunosenescence, but also of several autoimmune/inflammatory diseases. Vasoactive intestinal peptide (VIP) acts as an anti-inflammatory and immunomodulatory mediator on these cells. Our objective was to study the mutual influence between senescent Th cells and VIP axis in early arthritis (EA), comparing with non-EA donors. We characterized the correlation between senescent Th cells and clinic parameters of EA as well as the behavior of senescent Th biomarkers by real-time PCR. Clinical data were systematically recorded at baseline and after 6 months of follow-up. The number of CD4⁺CD28⁻ T cells measured by sorting is higher in patients who initially meet ACR classification criteria for rheumatoid arthritis (RA) compared to those who were classified as undifferentiated arthritis (UA). A slight positive correlation between EA CD4⁺CD28⁻ T cells and CRP or ESR and a negative correlation with bone mineral density were found. Th senescent biomarkers in EA CD4⁺CD28⁻ T cells were similar to donors, however some of them increased after 6 months of follow-up. VPAC receptors were analyzed by real-time PCR and immunofluorescence, and CD4⁺CD28⁻ T cells showed higher expression of VPAC₂ and lower of VPAC₁, VPAC₂ showing a significant increased expression in EA cells. Sorted CD4⁺CD28⁻ T cells were in vitro expanded in presence of VIP, wherein VIP increased senescent biomarker CD27, while it diminished CD57 or NKG2 senescent biomarkers. Our study demonstrates for the first time the existence of a link between senescent Th cells and the VIP axis.

VIP conditions human endometrial receptivity by privileging endoplasmic reticulum stress through ATF6α pathway

Endometrial stromal cells undergo endoplasmic reticulum (ER) stress and unfolded protein response (UPR) during the decidualization linked with the inflammation and angiogenesis processes. Considering VIP (vasoactive intestinal peptide) induces the decidualization program, we studied whether modulates the ER/UPR pathways to condition both processes for embryo implantation. When Human Endometrial Stromal Cell line (HESC) were decidualized by VIP we observed an increased expression of ATF6α, an ER stress-sensor, and UPR markers, associated with an increase in IL-1β production. Moreover, AEBSF (ATF6α -inhibitor pathway) prevented this effect and decreased the expansion index in the in vitro model of implantation. VIP-decidualized cells also favor angiogenesis accompanied by a strong downregulation in thrombospondin-1. Finally, ATF6α, VIP and VPAC2-receptor expression were reduced in endometrial biopsies from women with recurrent implantation failures in comparison with fertile. In conclusion, VIP privileged ATF6α-pathway associated with a sterile inflammatory response and angiogenesis that might condition endometrial receptivity.

Efficacy, safety and cost-effectiveness of a web-based platform delivering the results of a biomarker-based predictive model of biotherapy response for rheumatoid arthritis patients: a protocol for a randomized multicenter single-blind active controlled clinical trial (PREDIRA)

BACKGROUND

Rheumatoid arthritis (RA) is one of the leading chronic inflammatory rheumatism. First-line therapy with synthetic disease-modifying antirheumatic drugs (sDMARD) is insufficiently effective in 40% of cases and these patients are treated with biotherapies. The increased use of these drugs each year is becoming a public health issue with considerable economic burden. This cost is 20 times higher than that of sDMARD. However, among patients treated with biotherapies, clinical practice shows that about one third will not respond to the selected drug. In nonresponse cases, practitioners currently have no choice but to perform an empirical switching between different treatments, because no tool capable of predicting the response or nonresponse to these molecules is currently available.

METHODS

The study is a prospective, phase III, controlled, multicenter, and randomized, single-blind (patient) clinical trial, including RA patients with a previous failure to anti-TNF therapies. The main objective is the analysis of the clinical and pharmacoeconomic impact after 6 months of treatment. Intervention arm: prescription of biotherapy (rituximab, adalimumab, abatacept) using SinnoTest® software, a prediction software based on proteomic biomarkers. Control arm: prescription of biotherapy based on current practice, without the SinnoTest® software (any biotherapy). In addition, a substudy will be carried out within this trial to generate a biobank and further analyze the proteomic profile of the patients and their modification throughout the study.

DISCUSSION

This clinical trial study will be the first validation study of a biotherapy response prediction software, bringing personalized medicine into the management of RA. We expect that the findings from this study will bring several benefits for the patient and the Health Care System.

TRIAL REGISTRATION

ClincalTrials.gov NCT04147026 . Registered on 31 October, 2019.

Vasoactive intestinal peptide axis is dysfunctional in patients with Graves' disease

Vasoactive intestinal peptide (VIP) is a neuropeptide with potent immunoregulatory properties. Reduced serum VIP levels and alterations in VIP receptors/signaling on immune cells have been associated with different inflammatory/autoimmune diseases. However, its role in autoimmune thyroid diseases (AITD) remains unknown. This study examined the interrelationship between VIP system, autoimmune background and thyroid hormones in peripheral immune cells in patients with AITD. Only Graves' disease (GD) patients showed significantly lower serum VIP levels when compared to healthy subjects and to Hashimoto's thyroiditis patients. Serum VIP levels were lower at the onset of GD, showing a significant negative correlation with thyroid hormone levels. The expression of VIP receptors, VPAC1 and VPAC2, was significantly upregulated in peripheral blood mononuclear cells (PBMC) from GD patients. There was an impairment of VIP signalling in these patients, probably attributable to a dysfunction of VPAC1 with preservation of VPAC2. The correlation between VPAC1 and thyroid hormone receptor expression in PBMC from healthy subjects was lost in GD patients. In summary, the VIP system is altered in peripheral immune cells of GD patients and this finding is associated with different thyroid hormone receptor patterns, showing a dynamic inter-regulation and a prominent role of VIP in this setting.

A Clinical Approach for the Use of VIP Axis in Inflammatory and Autoimmune Diseases

The neuroendocrine and immune systems are coordinated to maintain the homeostasis of the organism, generating bidirectional communication through shared mediators and receptors. Vasoactive intestinal peptide (VIP) is the paradigm of an endogenous neuropeptide produced by neurons and endocrine and immune cells, involved in the control of both innate and adaptive immune responses. Exogenous administration of VIP exerts therapeutic effects in models of autoimmune/inflammatory diseases mediated by G-protein-coupled receptors (VPAC1 and VPAC2). Currently, there are no curative therapies for inflammatory and autoimmune diseases, and patients present complex diagnostic, therapeutic, and prognostic problems in daily clinical practice due to their heterogeneous nature. This review focuses on the biology of VIP and VIP receptor signaling, as well as its protective effects as an immunomodulatory factor. Recent progress in improving the stability, selectivity, and effectiveness of VIP/receptors analogues and new routes of administration are highlighted, as well as important advances in their use as biomarkers, contributing to their potential application in precision medicine. On the 50th anniversary of VIP's discovery, this review presents a spectrum of potential clinical benefits applied to inflammatory and autoimmune diseases.

Activation of Th lymphocytes alters pattern expression and cellular location of VIP receptors in healthy donors and early arthritis patients

Vasoactive Intestinal Peptide (VIP) is an important immunomodulator of CD4⁺ cells in normal and pathological conditions, which exerts its anti-inflammatory and immunomodulatory actions through VPAC receptors, VPAC₁ and VPAC₂. Only a decrease in the expression of VPAC₁ mRNA on Th cells upon activation has been reported. Thus, the deepening in the knowledge of the behavior of these receptors may contribute to the design of new therapies based on their activation and/or blockade. In this study, we describe the expression pattern, cellular location and functional role of VIP receptors during the activation of human Th cells in healthy conditions and in early arthritis (EA). The protein expression pattern of VPAC₁ did not change with the activation of Th lymphocytes, whereas VPAC₂ was up-regulated. In resting cells, VPAC₁ was located on the plasma membrane and nucleus, whereas it only appeared in the nucleus in activated cells. VPAC₂ was always found in plasma membrane location. VIP receptors signaled through a PKA-dependent pathway in both conditions, and also by a PKA-independent pathway in activated cells. Both receptors exhibit a potent immunomodulatory capacity by controlling the pathogenic profile and the activation markers of Th cells. These results highlight a novel translational view in inflammatory/autoimmune diseases.

An Overview of VPAC Receptors in Rheumatoid Arthritis: Biological Role and Clinical Significance

The axis comprised by the Vasoactive Intestinal Peptide (VIP) and its G protein-coupled receptors (GPCRs), VPAC1, and VPAC2, belong to the B1 family and signal through Gs or Gq proteins. VPAC receptors seem to preferentially interact with Gs in inflammatory cells, rather than Gq, thereby stimulating adenylate cyclase activity. cAMP is able to trigger various downstream pathways, mainly the canonical PKA pathway and the non-canonical cAMP-activated guanine nucleotide exchange factor (EPAC) pathway. Classically, the presence of VPACs has been confined to the plasma membrane; however, VPAC1 location has been described in the nuclear membrane in several cell types such as activated Th cells, where they are also functional. VPAC receptor signaling modulates a number of biological processes by tipping the balance of inflammatory mediators in macrophages and other innate immune cells, modifying the expression of TLRs, and inhibiting MMPs and the expression of adhesion molecules. Receptor signaling also downregulates coagulation factors and acute-phase proteins, promotes Th2 over Th1, stimulates Treg abundance, and finally inhibits a pathogenic Th17 profile. Thus, the VIP axis signaling regulates both the innate and adaptive immune responses in several inflammatory/autoimmune diseases. Rheumatoid arthritis (RA) is a complex autoimmune disease that develops on a substrate of genetically susceptible individuals and under the influence of environmental factors, as well as epigenetic mechanisms. It is a heterogeneous disease with different pathogenic mechanisms and variable clinical forms between patients with the same diagnosis. The knowledge of VIP signaling generated in both animal models and human ex vivo studies can potentially be translated to clinical reality. Most recently, the beneficial effects of nanoparticles of VIP self-associated with sterically stabilized micelles have been reported in a murine model of RA. Another novel research area is beginning to define the receptors as biomarkers in RA, with their expression levels shown to be associated with the activity of the disease and patients-reported impairment. Therefore, VPAC expression together VIP genetic variants could allow patients to be stratified at the beginning of the disease with the purpose of guiding personalized treatment decisions.

Regulatory role of capsaicin-sensitive peptidergic sensory nerves in the proteoglycan-induced autoimmune arthritis model of the mouse

Objective

The regulatory role of capsaicin-sensitive peptidergic sensory nerves has been shown in acute inflammation, but little is known about their involvement in T/B-cell driven autoimmune arthritis. This study integratively characterized the function of these nerve endings in the proteoglycan-induced chronic arthritis (PGIA), a translational model of rheumatoid arthritis.

Methods

Peptidergic afferents were defunctionalized by resiniferatoxin (RTX) pretreatment in BALB/c mice, PGIA was induced by repeated antigen challenges. Hind paw volume, arthritis severity, grasping ability and the mechanonociceptive threshold were monitored during the 17-week experiment. Myeloperoxidase activity, vascular leakage and bone turnover were evaluated by in vivo optical imaging. Bone morphology was assessed using micro-CT, the intertarsal small joints were processed for histopathological analysis.

Results

Following desensitization of the capsaicin-sensitive afferents, ankle edema, arthritis severity and mechanical hyperalgesia were markedly diminished. Myeloperoxidase activity was lower in the early, but increased in the late phase, whilst plasma leakage and bone turnover were not altered. Desensitized mice displayed similar bone spurs and erosions, but increased trabecular thickness of the tibia and bony ankylosis of the spine. Intertarsal cartilage thickness was not altered in the model, but desensitization increased this parameter in both the non-arthritic and arthritic groups.

Conclusion

This is the first integrative in vivo functional and morphological characterization of the PGIA mouse model, wherein peptidergic afferents have an important regulatory function. Their overall effect is proinflammatory by increasing acute inflammation, immune cell activity and pain. Meanwhile, their activation decreases spinal ankylosis, arthritis-induced altered trabecularity, and cartilage thickness in small joints.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1364-5) contains supplementary material, which is available to authorized users.

Complex Role of Capsaicin-Sensitive Afferents in the Collagen Antibody-Induced Autoimmune Arthritis of the Mouse

Capsaicin-sensitive afferents have complex regulatory functions in the joints orchestrated via neuropeptides. This study aimed to determine their role in the collagen-antibody induced rheumatoid arthritis model. Capsaicin-sensitive nerves were defunctionalized by the capsaicin receptor agonist resiniferatoxin in C57Bl/6 mice. Arthritis was induced by the ArithroMab antibody cocktail and adjuvant. Arthritis was monitored by measuring body weight, joint edema by plethysmometry, arthritis severity by clinical scoring, mechanonociceptive threshold by plantar esthesiometry, thermonociceptive threshold by hot plate, cold tolerance by paw withdrawal latency from 0 °C water. Grasping ability was determined by the wire-grid grip test. Bone structure was evaluated by in vivo micro-CT and histology. Arthritic animals developed a modest joint edema, mechanical and cold hyperalgesia, weight loss, and a diminished grasping function, while thermal hyperalgesia is absent in the model. Desensitised mice displayed reduced arthritis severity, edema, and mechanical hyperalgesia, however, cold hyperalgesia was significantly greater in this group. Arthritic controls displayed a transient decrease of bone volume and an increased porosity, while bone density and trabecularity increased in desensitised mice. The activation of capsaicin-sensitive afferents increases joint inflammation and mechanical hyperalgesia, but decreases cold allodynia. It also affects inflammatory bone structural changes by promoting bone resorption.

Vasoactive intestinal peptide degradation might influence Interleukin-17 expression in cardiac chagasic patients

The vasoactive intestinal peptide (VIP) expression is lower in cardiac chagasic patients and is related to worse cardiac function. The reduction of VIP in patients with Chagas disease may be a result of its enhanced degradation. To test this hypothesis, the tryptase and chymase expression was evaluated. We also related VIP levels with interleukin-17 (IL-17) expression since VIP may modulate IL-17 production. Plasma levels of chymase were higher in chagasic patients. Conversely, VIP/chymase and VIP/tryptase ratios were lower in chagasic patients when compared to non-infected individuals. Besides, the VIP/chymase ratio was lower in chagasic cardiac patients in comparison with the indeterminate group. A positive correlation between tryptase and chymase levels was observed in chagasic cardiac patients. In relation to IL-17, we observed a higher expression of this cytokine in the cardiac form of the disease than in the indeterminate form. IL-17/VIP ratio was higher in the cardiac form in comparison with non-infected or indeterminate form. These results suggest that the low levels of VIP observed in chagasic patients could be due to an increased production of chymase and/or to the additive effect of the interaction between chymase and tryptase in the cardiac form. Moreover, the decreased VIP expression may contribute to the increase of IL-17 in chagasic cardiac patients.

Contribution of the bone and cartilage/soft tissue components of the joint damage to the level of disability in rheumatoid arthritis patients: a longitudinal study

The study aims to analyze the association between the bone and cartilage/periarticular components of the radiographic joint damage and disability over the course of disease, in a cohort of rheumatoid arthritis (RA) patients from a day-to-day clinical practice. The secondary aim is to study the role of demographic and disease-related variables in this association. We performed a retrospective longitudinal study including 736 RA patients. Disability was assessed with the health assessment questionnaire (HAQ), and radiographic joint damage of hands and wrists with the Sharp van-der-Heijde score (total (SHS), erosion (ES), and narrowing/(sub)luxation (NSLS) components]. Generalized estimating equations models, adjusted by disease activity, demographic and disease-related variables, were used to test the relationship between SHS and medium-term (median value of the HAQs performed in the following year after each radiograph) and long-term (set of HAQ measures performed during follow-up, at least 1 year apart from the first x-ray) disability. Interaction terms between the SHS and demographic and disease-related variables were introduced in the models. To account for multiple testing, Bonferroni correction was applied. NSLS was independently associated with medium-term disability, even after Bonferroni correction. We observed significant and positive interactions between NSLS and age at x-ray, and with the ES. SHS showed no association with long-term disability. The cartilage/soft tissue component of the radiographic joint damage seems to exert a much more important role in medium-term disability than the erosive component. This association could be modulated by the age at the x-ray and by the magnitude of the erosive damage.

Immunomodulatory Roles of PACAP and VIP: Lessons from Knockout Mice

A bidirectional cross-talk is established between the nervous and immune systems through common mediators including neuropeptides, neurotransmitters, and cytokines. Among these, PACAP and VIP are two highly related neuropeptides widely distributed in the organism with purported immunomodulatory actions. Due to their well-known anti-inflammatory properties, administration of these peptides has proven to be beneficial in models of acute and chronic inflammatory diseases. Nevertheless, the relevance of the endogenous source of these peptides in the modulation of immune responses remains to be elucidated. The development of transgenic mice with specific deletions in the genes coding for these neuropeptides (Vip and Adcyap1) or for their G-protein-coupled receptors VPAC1, VPAC2, and PAC1 (Vipr1, Vipr2, Adcyap1r1) has allowed to address this question, underscoring the complexity of the immunoregulatory properties of PACAP and VIP. The goal of this review is to integrate the existing information on the immune phenotypes of mice deficient for PACAP, VIP, or their receptors, to provide a global view on the roles of these endogenous neuropeptides during immunological health and disease.

The Anti-Inflammatory Mediator, Vasoactive Intestinal Peptide, Modulates the Differentiation and Function of Th Subsets in Rheumatoid Arthritis

Genetic background, epigenetic modifications, and environmental factors trigger autoimmune response in rheumatoid arthritis (RA). Several pathogenic infections have been related to the onset of RA and may cause an inadequate immunological tolerance towards critical self-antigens leading to chronic joint inflammation and an imbalance between different T helper (Th) subsets. Vasoactive intestinal peptide (VIP) is a mediator that modulates all the stages comprised between the arrival of pathogens and Th cell differentiation in RA through its known anti-inflammatory and immunomodulatory actions. This “neuroimmunopeptide” modulates the pathogenic activity of diverse cell subpopulations involved in RA as lymphocytes, fibroblast-like synoviocytes (FLS), or macrophages. In addition, VIP decreases the expression of pattern recognition receptor (PRR) such as toll-like receptors (TLRs) in FLS from RA patients. These receptors act as sensors of pathogen-associated molecular pattern (PAMP) and damage-associated molecular pattern (DAMP) connecting the innate and adaptive immune system. Moreover, VIP modulates the imbalance between Th subsets in RA, decreasing pathogenic Th1 and Th17 subsets and favoring Th2 or Treg profile during the differentiation/polarization of naïve or memory Th cells. Finally, VIP regulates the plasticity between theses subsets. In this review, we provide an overview of VIP effects on the aforementioned features of RA pathology.

Vasoactive intestinal peptide gene polymorphisms, associated with its serum levels, predict treatment requirements in early rheumatoid arthritis

We previously reported that early arthritis (EA) patients with low vasoactive intestinal peptide (VIP) serum levels demonstrate a worse clinical disease course. In this study, we analysed whether variants in the VIP gene correlated with its serum levels and clinical EA parameters. The VIP gene was sequenced in patients with extremely high/low VIP levels, measured by enzyme immunoassay. Sixteen single nucleotide polymorphisms (SNPs) were differentially distributed between both groups, which were subsequently genotyped in two patients’ sets. We observed that patients with rs688136 CC genotype showed higher VIP levels in both discovery (n = 91; p = 0.033) and validation populations (n = 131; p = 0.007). This effect was attenuated by the presence of minor alleles rs35643203 and rs12201140, which showed a clear trend towards low VIP level association (p = 0.118 and p = 0.049, respectively). Functional studies with miR-205-5p, which has a target site in the 3′ UTR close to rs688136, revealed a miRNA-mediated regulatory mechanism explaining the higher VIP gene expression in homozygous patients. Moreover, patients with an rs688136 CC genotype and no minor alleles of the other polymorphisms required less treatment (p = 0.009). We concluded that the identification of polymorphisms associated with VIP serum levels would complement the clinical assessment of the disease severity in rheumatoid arthritis patients.

[Expression of vasoactive intestinal peptide in peripheral blood of children with hand, foot and mouth disease]

OBJECTIVE

To investigate the expression of vasoactive intestinal peptide (VIP) in peripheral blood of children with hand, foot and mouth disease and its significance.

METHODS

According to the condition of the disease, 86 children with hand, foot and mouth disease were classified into phase 1 group (19 children) and phase 2 group (67 children). ELISA was used to measure the concentrations of plasma VIP, interferon-γ (IFN-γ), and interleukin-4 (IL-4) in peripheral blood. Flow cytometry was used to measure CD3⁺, CD4⁺, and CD8⁺ T lymphocyte subsets. RT-PCR was used for qualitative detection of enterovirus 71 (EV71) RNA in stool.

RESULTS

Compared with the phase 1 group, the phase 2 group had a significantly higher positive rate of EV71-RNA (P<0.05) and significantly higher serum levels of IgG, IgA, IgM, and C3 (P<0.05). The phase 2 group had significantly lower proportions of peripheral CD3⁺, CD4⁺, and CD8⁺ T lymphocyte subsets than the phase 1 group (P<0.05), as well as significantly lower proportion of peripheral B cells and CD4⁺/CD8⁺ ratio than the phase 1 group (P<0.05). The phase 2 group also had a significantly lower concentration of VIP in peripheral blood than the phase 1 group (P<0.05). In the 86 children with hand, foot and mouth disease, the concentration of VIP in peripheral blood was positively correlated with the proportion of CD4⁺ T lymphocyte subset and CD4⁺/CD8⁺ ratio (r=0.533 and 0.532 respectively; P<0.05).

CONCLUSIONS

VIP may be an important marker of the severity of hand, foot and mouth disease.

[Expression of vasoactive intestinal peptide in peripheral blood of children with hand, foot and mouth disease]

OBJECTIVE

To investigate the expression of vasoactive intestinal peptide (VIP) in peripheral blood of children with hand, foot and mouth disease and its significance.

METHODS

According to the condition of the disease, 86 children with hand, foot and mouth disease were classified into phase 1 group (19 children) and phase 2 group (67 children). ELISA was used to measure the concentrations of plasma VIP, interferon-γ (IFN-γ), and interleukin-4 (IL-4) in peripheral blood. Flow cytometry was used to measure CD3+, CD4+, and CD8+ T lymphocyte subsets. RT-PCR was used for qualitative detection of enterovirus 71 (EV71) RNA in stool.

RESULTS

Compared with the phase 1 group, the phase 2 group had a significantly higher positive rate of EV71-RNA (P<0.05) and significantly higher serum levels of IgG, IgA, IgM, and C3 (P<0.05). The phase 2 group had significantly lower proportions of peripheral CD3+, CD4+, and CD8+ T lymphocyte subsets than the phase 1 group (P<0.05), as well as significantly lower proportion of peripheral B cells and CD4+/CD8+ ratio than the phase 1 group (P<0.05). The phase 2 group also had a significantly lower concentration of VIP in peripheral blood than the phase 1 group (P<0.05). In the 86 children with hand, foot and mouth disease, the concentration of VIP in peripheral blood was positively correlated with the proportion of CD4+ T lymphocyte subset and CD4+/CD8+ ratio (r=0.533 and 0.532 respectively; P<0.05).

CONCLUSIONS

VIP may be an important marker of the severity of hand, foot and mouth disease.

VIP impairs acquisition of the macrophage proinflammatory polarization profile

This study tested the hypothesis that vasoactive intestinal peptide (VIP) is able to modify the macrophage inflammatory profile, thus supporting its therapeutic role in autoimmune diseases. Macrophages are innate immune cells that display a variety of functions and inflammatory profiles in response to the environment that critically controls their polarization. Deregulation between the pro- and anti-inflammatory phenotypes has been involved in different pathologies. Rheumatoid arthritis (RA) is an autoimmune disease, in which macrophages are considered central effectors of synovial inflammation, displaying a proinflammatory profile. VIP is a pleiotropic neuropeptide with proven anti-inflammatory actions. As modulation of the macrophage phenotype has been implicated in the resolution of inflammatory diseases, we evaluated whether VIP is able to modulate human macrophage polarization. In vitro-polarized macrophages by GM-CSF (GM-MØ), with a proinflammatory profile, expressed higher levels of VIP receptors, vasoactive intestinal polypeptide receptors 1 and 2 (VPAC1 and VPAC2, respectively), than macrophages polarized by M-CSF (M-MØ) with anti-inflammatory activities. RA synovial macrophages, according to their GM-CSF-like polarization state, expressed both VPAC1 and VPAC2. In vitro-generated GM-MØ exposed to VIP exhibited an up-regulation of M-MØ gene marker expression, whereas their proinflammatory cytokine profile was reduced in favor of an anti-inflammatory function. Likewise, in GM-MØ, generated in the presence of VIP, VIP somehow changes the macrophages physiology profile to a less-damaging phenotype. Therefore, these results add new value to VIP as an immunomodulatory agent on inflammatory diseases.

Clinical Relevance of VPAC1 Receptor Expression in Early Arthritis: Association with IL-6 and Disease Activity

Background

The vasoactive intestinal peptide (VIP) receptors VPAC1 and VPAC2 mediate anti-inflammatory and immunoregulatory responses in rheumatoid arthritis (RA). Data on the expression of these receptors could complement clinical assessment in the management of RA. Our goal was to investigate the correlation between expression of both receptors and the 28-Joint Disease Activity Score (DAS28) in peripheral blood mononuclear cells (PBMCs) from patients with early arthritis (EA). We also measured expression of IL-6 to evaluate the association between VIP receptors and systemic inflammation.

Methods

We analyzed 250 blood samples collected at any of the 5 scheduled follow-up visits from 125 patients enrolled in the Princesa Early Arthritis Register Longitudinal study. Samples from 22 healthy donors were also analyzed. Sociodemographic, clinical, and therapeutic data were systematically recorded. mRNA expression levels were determined using real-time PCR. Then, longitudinal multivariate analyses were performed.

Results

PBMCs from EA patients showed significantly higher expression of VPAC2 receptors at baseline compared to healthy donors (p<0.001). With time, however, VPAC2 expression tended to be significantly lower while VPAC1 receptor expression increased in correlation with a reduction in DAS28 index. Our results reveal that more severe inflammation, based on high levels of IL-6, is associated with lower expression of VPAC1 (p<0.001) and conversely with increased expression of VPAC2 (p<0.001). A major finding of this study is that expression of VPAC1 is lower in patients with increased disease activity (p = 0.001), thus making it possible to differentiate between patients with various degrees of clinical disease activity.

Conclusion

Patients with more severe inflammation and higher disease activity show lower levels of VPAC1 expression, which is associated with patient-reported impairment. Therefore, VPAC1 is a biological marker in EA.

VIP and CRF reduce ADAMTS expression and function in osteoarthritis synovial fibroblasts

ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family is known to play an important role in the pathogenesis of osteoarthritis (OA), working on aggrecan degradation or altering the integrity of extracellular matrix (ECM). Thus, the main purpose of our study was to define the role of vasoactive intestinal peptide (VIP) and corticotrophin-releasing factor (CRF), as immunoregulatory neuropeptides, on ADAMTS production in synovial fibroblasts (SF) from OA patients and healthy donors (HD). OA- and HD-SF were stimulated with pro-inflammatory mediators and treated with VIP or CRF. Both neuropeptides decreased ADAMTS-4, -5, -7 and -12 expressions, aggrecanase activity, glycosaminoglycans (GAG), and cartilage oligomeric matrix protein (COMP) degradation after stimulation with fibronectin fragments (Fn-fs) in OA-SF. After stimulation with interleukin-1β, VIP reduced ADAMTS-4 and -5, and both neuropeptides decreased ADAMTS-7 production and COMP degradation. Moreover, VIP and CRF reduced Runx2 and β-catenin activation in OA-SF. Our data suggest that the role of VIP and CRF on ADAMTS expression and cartilage degradation could be related to the OA pathology since scarce effects were produced in HD-SF. In addition, their effects might be greater when a degradation loop has been established, given that they were higher after stimulation with Fn-fs. Our results point to novel OA therapies based on the use of neuropeptides, since VIP and CRF are able to stop the first critical step, the loss of cartilage aggrecan and the ECM destabilization during joint degradation.

Th17 polarization of memory Th cells in early arthritis: the vasoactive intestinal peptide effect

Several studies in humans indicate the implication of Th17 cells in RA. Therapies targeting their pathogenicity, as well as their plasticity to the Th17/1 phenotype, could ameliorate the progression of the pathology. The neuroendocrine environment has a major impact on the differentiation of lymphoid cells. VIP is present in the microenvironment of the joint, and its known therapeutic effects are supported by several studies on RA. We examine the ability of VIP to modulate the differentiation of Th17 cells. Peripheral blood CD4(+)CD45RO(+) T cells from HD and eRA patients were expanded under Th17-polarizing conditions in the presence of TGF-β. After 7 days, the higher IL-17A, IL-21, and IL-9 levels and lower IL-22 levels indicate the nonpathogenic profile for Th17 cells in HD. In contrast, Th17 cells from eRA patients produced significantly more IL-22 and IFN-γ, and these cells show a more Th17/1 profile, indicating a pathogenic phenotype. Interestingly, when VIP was present in the Th17 conditioned medium, increased levels of IL-10 and IL-9 were detected in HD and eRA patients. VIP also reduced the levels of IL-22 in eRA patients. These data suggest that VIP reduces the pathogenic profile of the Th17-polarized cells. This effect was accompanied by an increased in the Treg/Th17 profile, as shown by the increase levels of Foxp3. In conclusion, this report addresses a novel and interesting question on the effect of VIP on human Th17 cells and adds clinical relevance by analyzing, in parallel, HD and eRA patients.

Biomarkers predicting a need for intensive treatment in patients with early arthritis

The heterogeneous nature of rheumatoid arthritis (RA) complicates early recognition and treatment. In recent years, a growing body of evidence has demonstrated that intervention during the window of opportunity can improve the response to treatment and slow—or even stop—irreversible structural changes. Advances in therapy, such as biologic agents, and changing approaches to the disease, such as the treat to target and tight control strategies, have led to better outcomes resulting from personalized treatment to patients with different prognostic markers. The various biomarkers identified either facilitate early diagnosis or make it possible to adjust management to disease activity or poor outcomes. However, no single biomarker can bridge the gap between disease onset and prescription of the first DMARD, and traditional biomarkers do not identify all patients requiring early aggressive treatment. Furthermore, the outcomes of early arthritis cohorts are largely biased by the treatment prescribed to patients; therefore, new challenges arise in the search for prognostic biomarkers. Herein, we discuss the value of traditional and new biomarkers and suggest the need for intensive treatment as a new surrogate marker of poor prognosis that can guide therapeutic decisions in the early stages of RA.

Vasoactive Intestinal Peptide in Early Spondyloarthritis: Low Serum Levels as a Potential Biomarker for Disease Severity

Spondyloarthritis (SpA) is a family of inflammatory diseases sharing clinical, genetic, and radiological features. While crucial for tailoring early interventions, validated prognostic biomarkers are scarce in SpA. We analyze the correlation between serum levels of vasoactive intestinal peptide (VIP) and disease activity/severity in patients with early chronic inflammatory back pain. The study population comprised 54 patients enrolled in our early chronic inflammatory back pain register. We collected demographic information, clinical data, laboratory data, and imaging findings. VIP levels were measured by enzyme immunoassay in serum samples from 162 visits. The association between independent variables and VIP levels was analyzed using longitudinal multivariate analysis nested by patient and visit. No significant differences were observed in VIP levels between these two groups. Lower levels of VIP were significantly associated with a higher Bath Ankylosing Spondylitis Disease Activity Index (BASFI) score, presence of bone edema in magnetic resonance imaging (MRI) scan, and lower hemoglobin levels. Coexistence of cutaneous psoriasis was independently associated with lower VIP levels, and similar trend was observed for enthesitis. We conclude that SpA patients with low serum VIP levels had worse 2-year disease outcome, suggesting that serum VIP levels could be a valid prognostic biomarker.

The neuropeptide vasoactive intestinal peptide: direct effects on immune cells and involvement in inflammatory and autoimmune diseases

Neuropeptides represent an important category of endogenous contributors to the establishment and maintenance of immune deviation in the immune-privileged organs such as the CNS and in the control of acute inflammation in the peripheral immune organs. Vasoactive intestinal peptide (VIP) is a major immunoregulatory neuropeptide widely distributed in the central and peripheral nervous system. In addition to neurones, VIP is synthesized by immune cells which also express VIP receptors. Here, we review the current information on VIP production and VIP-receptor-mediated effects in the immune system, the role of endogenous and exogenous VIP in inflammatory and autoimmune disorders and the present and future VIP therapeutic approaches.

The pathogenic Th profile of human activated memory Th cells in early rheumatoid arthritis can be modulated by VIP

Our aim is to study the behavior of memory Th cells (Th17, Th17/1, and Th1 profiles) from early rheumatoid arthritis (eRA) patients after their in vitro activation/expansion to provide information about its contribution to RA chronicity. Moreover, we analyzed the potential involvement of vasoactive intestinal peptide (VIP) as an endogenous healing mediator. CD4(+)CD45RO(+) T cells from PBMCs of HD and eRA were activated/expanded in vitro in the presence/absence of VIP. FACS, ELISA, RT-PCR, and immunocytochemistry analyses were performed. An increase in CCR6(+)/RORC(+) cells and in RORC-proliferating cells and a decrease in T-bet-proliferating cells and T-bet(+)/RORC(+) cells were shown in eRA. mRNA expression of IL-17, IL-2, RORC, RORA, STAT3, and Tbx21 and protein secretion of IL-17, IFNγ, and GM-CSF were higher in eRA. VIP decreased the mRNA expression of IL-22, IL-2, STAT3, Tbx21, IL-12Rβ2, IL-23R, and IL-21R in HD and it decreased IL-21, IL-2, and STAT3 in eRA. VIP decreased IL-22 and GM-CSF secretion and increased IL-9 secretion in HD and it decreased IL-21 secretion in eRA. VPAC2/VPAC1 ratio expression was increased in eRA. All in all, memory Th cells from eRA patients show a greater proportion of Th17 cells with a pathogenic Th17 and Th17/1 profile compared to HD. VIP is able to modulate the pathogenic profile, mostly in HD. Our results are promising for therapy in the early stages of RA because they suggest that targeting molecules involved in the pathogenic Th17, Th17/1, and Th1 phenotypes and targeting VIP receptors could have a therapeutic effect modulating these subsets.

KEY MESSAGES

Th17 cells are more important than Th1 in the contribution to pathogenesis in eRA patients. Pathogenic Th17 and Th17/1 profile are abundant in activated/expanded memory Th cells from eRA patients. VIP decreases the pathogenic Th17, Th1, and Th17/1 profiles, mainly in healthy donors. The expression of VIP receptors is reduced in eRA patients respect to healthy donors, whereas the ratio of VPAC2/VPAC1 expression is higher.