Prothymosin α Lacking the Nuclear Localization Signal as an Effective Gene Therapeutic Strategy in Collagen-Induced Arthritis

Antibodies of the immunoglobulin a isotype to novel antigens in early axial spondyloarthritis

Introduction

There is an unmet need for biomarkers to identify patients with axial spondyloarthritis (axSpA). Increasing evidence suggest the presence of autoantibodies in a subset of axSpA patients. The aim of this study was to identify novel IgA antibodies in early axSpA patients and to determine their diagnostic potential in combination with previously determined IgG antibodies against UH (Hasselt University)-axSpA-IgG antigens.

Methods

An axSpA cDNA phage display library constructed from axSpA hip synovium, was used to screen for novel IgA antibodies in plasma from early axSpA patients. The presence of these antibodies against novel UH-axSpA-IgA antigens was determined in two independent axSpA cohorts, in healthy controls and in patients with chronic low back pain.

Results

We identified antibodies to 7 novel UH-axSpA-IgA antigens, of which 6 correspond to non-physiological peptides and 1 to the human histone deacetylase 3 (HDAC3) protein. IgA antibodies against 2 of these 7 novel UH-axSpA-IgA antigens and IgG antibodies against 2 of the previously identified antigens were significantly more present in early axSpA patients from the UH cohort (18/70, 25.7%) and the (Bio)SPAR cohort (26/164, 15.9%), compared to controls with chronic low back pain (2/66, 3%). Antibodies to this panel of 4 antigens were present in 21.1% (30/142) of patients with early axSpA from the UH and (Bio)SPAR cohorts. The positive likelihood ratio for confirming early axSpA using antibodies to these 4 UH-axSpA antigens was 7.0. So far, no clinical correlation between the novel identified IgA antibodies and inflammatory bowel disease could be identified.

Discussion

In conclusion, screening an axSpA cDNA phage display library for IgA reactivity resulted in the identification of 7 novel UH-axSpA-IgA antigens, of which 2 show promising biomarker potential for the diagnosis of a subset of axSpA patients, in combination with previously identified UH-axSpA-IgG antigens.

The S100A7 nuclear interactors in autoimmune diseases: a coevolutionary study in mammals

S100A7, a member of the S100A family of Ca²⁺-binding proteins, is considered a key effector in immune response. In particular, S100A7 dysregulation has been associated with several diseases, including autoimmune disorders. At the nuclear level, S100A7 interacts with several protein-binding partners which are involved in transcriptional regulation and DNA repair. By using the BioGRID and GAAD databases, S100A7 nuclear interactors with a putative involvement in autoimmune diseases were retrieved. We selected fatty acid-binding protein 5 (FABP5), autoimmune regulator (AIRE), cystic fibrosis transmembrane conductance regulator (CFTR), chromodomain helicase DNA-binding protein 4 (CHD4), epidermal growth factor receptor (EGFR), estrogen receptor 1 (ESR1), histone deacetylase 2 (HDAC2), v-myc avian myelocytomatosis viral oncogene homolog (MYC), protection of telomeres protein 1 (POT1), telomeric repeat-binding factor (NIMA-interacting) 1 (TERF1), telomeric repeat-binding factor 2 (TERF2), and Zic family member 1 (ZIC1). Linear correlation coefficients between interprotein distances were calculated with MirrorTree. Coevolution clusters were also identified with the use of a recent version of the Blocks in Sequences (BIS2) algorithm implemented in the BIS2Analyzer web server. Analysis of pair positions identified interprotein coevolving clusters between S100A7 and the binding partners CFTR and TERF1. Such findings could guide further analysis to better elucidate the function of S100A7 and its binding partners and to design drugs targeting for these molecules in autoimmune diseases.

Gene therapy in rheumatoid arthritis: Strategies to select therapeutic genes

Significant advances have been achieved in recent years to ameliorate rheumatoid arthritis (RA) in animal models using gene therapy approaches rather than biological treatments. Although biological agents serve as antirheumatic drugs with suppressing proinflammatory cytokine activities, they are usually accompanied by systemic immune suppression resulting from continuous or high systemic dose injections of biological agents. Therefore, gene transfer approaches have opened an interesting perspective to deliver one or multiple genes in a target-specific or inducible manner for the sustained intra-articular expression of therapeutic products. Accordingly, many studies have focused on gene transferring methods in animal models by using one of the available approaches. In this study, the important strategies used to select effective genes for RA gene therapy have been outlined. Given the work done in this field, the future looks bright for gene therapy as a new method in the clinical treatment of autoimmune diseases such as RA, and by ongoing efforts in this field, we hope to achieve feasible, safe, and effective treatment methods.

Deletion of Nuclear Localizing Signal Attenuates Proinflammatory Activity of Prothymosin-Alpha and Enhances Its Neuroprotective Effect on Transient Ischemic Stroke

Post-ischemic inflammation plays an important role in the progression of ischemia/reperfusion injuries. Prothymosin-α (ProT) can protect cells from necrotic death following ischemia; however, its immunostimulatory actions may counteract the neuroprotective effect. We proposed that ProTΔNLS, synthesized by deleting its nuclear localizing signal (NLS) at the C-terminal of ProT, can attenuate the immunostimulatory activity and has more salient neuroprotective effect. In this study, we examined the therapeutic effects of ProT and ProTΔNLS in a transient middle cerebral artery occlusion (tMCAO) model of rats. Rats that had sustained 90 min of tMCAO were treated with GST-vehicle, ProT, or ProTΔNLS. Therapeutic outcomes were evaluated by infarction volume assay and behavioral assessment. Changes to inflammatory mediators, including tumor necrosis factor α (TNF-α), interleukin-10 (IL-10), and myeloperoxidase (MPO) were evaluated by enzyme-linked immunosorbent assay. Activated matrix metalloproteinases 2 (MMP-2) and 9 (MMP-9) levels were evaluated by gelatin zymography. Microglial activation was identified by double-immunostaining for Iba-1 and CD68. Our results showed that while both ProT and ProTΔNLS reduce infarction volume and improve functional outcome, ProTΔNLS provides the best therapeutic outcome. ProT increases TNF-α but decreases IL-10 secretion after ischemic injury, reflecting its pro-inflammatory activity. ProTΔNLS suppresses expression of TNF-α, MPO, and activity of MMPs in ischemic brain tissue. It also suppresses activation of microglia in penumbral cortex. These data demonstrate the immunesuppressive activities of ProTΔNLS. In conclusion, ProT has pro-inflammatory effect that may counteract its neuroprotective effect. Deletion of NLS from ProT may attenuate post-ischemic inflammation and enhance the neuroprotective effects of ProT.

Adenovirus-mediated prothymosin α gene transfer inhibits the development of atherosclerosis in ApoE-deficient mice

Prothymosin α (ProT) is involved in regulating expression of the oxidative stress-protective genes and it also exerts immunomodulatory activities. In this study, we investigated the therapeutic effects of ProT gene transfer on atherosclerosis in endothelial cells and in ApoE-deficient mice. Adenoviruses encoding mouse ProT (AdProT) were used for the management of atherosclerosis. In vitro, the effects of ProT on antioxidant gene expressions and the protection effect against oxidant-mediated injury in endothelial cells were examined. In vivo, AdProT were administered intraventricularly into the heart of ApoE(-/-) mice. Histopathological and immunohistochemical assessments of the aortic tissues were performed. Expressions of HO-1 and antioxidant genes in the aortic tissues were also determined. Our results demonstrated that ProT gene transfer increased antioxidant gene expressions, eNOS expression and NO release, as well as reduced the reactive oxygen species production in endothelial cells. Intraventricular administration of AdProT reduced the lesion formation, increased expressions of HO-1 and SOD genes, and reduced infiltrating macrophages in the aorta of ApoE(-/-) mice. This study suggests that ProT gene transfer may have the therapeutic potential for the management of atherosclerosis via inducing antioxidant gene expressions, eNOS expression and NO release, reducing ROS production and macrophage infiltration in endothelium.

Prothymosin α overexpression contributes to the development of pulmonary emphysema

Emphysema is one of the disease conditions that comprise chronic obstructive pulmonary disease. Prothymosin α transgenic mice exhibit an emphysema phenotype, but the pathophysiological role of prothymosin α in emphysema remains unclear. Here we show that prothymosin α contributes to the pathogenesis of emphysema by increasing acetylation of histones and nuclear factor-kappaB, particularly upon cigarette smoke exposure. We find a positive correlation between prothymosin α levels and the severity of emphysema in prothymosin α transgenic mice and emphysema patients. Prothymosin α overexpression increases susceptibility to cigarette smoke-induced emphysema, and cigarette smoke exposure further enhances prothymosin α expression. We show that prothymosin α inhibits the association of histone deacetylases with histones and nuclear factor-kappaB, and that prothymosin α overexpression increases expression of nuclear factor-kappaB-dependent matrix metalloproteinase 2 and matrix metalloproteinase 9, which are found in the lungs of patients with chronic obstructive pulmonary disease. These results demonstrate the clinical relevance of prothymosin α in regulating acetylation events during the pathogenesis of emphysema.

Pulmonary emphysema obstruct airflow in the lung and often develop in smokers. Here Su et al. show that prothymosin α contributes to emphysema development through alterations in the acetylation of histones and the transcription factor NF-κB, and that exposure to cigarette smoke increases prothymosin α expression.

Suppression of collagen-induced arthritis by intra-articular lentiviral vector-mediated delivery of Toll-like receptor 7 short hairpin RNA gene

Knockdown of Toll-like receptors (TLRs) is a novel therapeutic strategy in treating patients with rheumatoid arthritis (RA). We examined the effects of lentiviral vector-mediated delivery of TLR7 short hairpin RNA gene (Lt.shTLR7) on collagen-induced arthritis (CIA). After being immunized on days 0 and 7, Sprague-Dawley rats received intra-articular (i.a.) injection of Lt.shTLR7 or scramble control vector on days 7 and 10. The therapeutic effects were evaluated by measuring ankle circumferences, articular index, and radiographic and histological scores on killing on day 16. Microvessel densities, vascular endothelial growth factor (VEGF) levels, pro-inflammatory cytokine concentrations and T-cell numbers within the synovial tissues were measured. Moreover, VEGF and pro-inflammatory cytokine concentrations in culture supernatants from TLR7-transfected synovial fibroblasts (SFs) stimulated with imiquimod or endogenous ligands were examined. There were significant reduction in ankle circumferences, articular indexes, and radiographic and histological scores. Microvessel densities, VEGF concentrations, interleukin (IL)-1β and IL-6 levels and T-cell densities within synovial tissues were significantly lower. Induction of VEGF, IL-1β and IL-6 production from stimulated SFs was significantly suppressed. Taken together, these data demonstrate the effects of i.a. lentiviral vector-mediated delivery of shTLR7 RNA gene on inhibition of CIA, and implicate the manipulation of TLR7 as a potential therapeutic strategy in RA patients.

Amelioration of experimental arthritis by a telomerase-dependent conditionally replicating adenovirus that targets synovial fibroblasts

OBJECTIVE

Synovial fibroblasts (SFs) play a pivotal role in the pathogenesis of rheumatoid arthritis (RA). It has been documented that the phenotype of rheumatoid synovium is similar, in many respects, to that of an aggressive tumor. In this study, a novel, genetically engineered adenovirus was designed to lyse SFs that exhibit high telomerase activity and p53 mutations, and its effects as a novel therapeutic strategy were assessed in an experimental arthritis model.

METHODS

An E1B-55-kd-deleted adenovirus driven by the human telomerase reverse transcriptase promoter was constructed (designated Ad.GS1). Cytolysis of SFs and productive replication of Ad.GS1 in the SFs of rats with collagen-induced arthritis (CIA), as well as the SFs of patients with RA (RASFs), were assessed in vitro and in vivo. Treatment responses, as well as the presence of disease-related cytokines and enzymes in the ankle joints, were determined in the murine model.

RESULTS

Ad.GS1 replicated in and induced cytolysis of human RASFs and SFs from arthritic rats, but spared normal fibroblasts. Bioluminescence imaging in vivo also demonstrated replication of Ad.GS1 in arthritic rat joints, but not in normal rat joints. Intraarticular administration of Ad.GS1 significantly reduced the ankle circumference, articular index scores, radiographic scores, and histologic scores and decreased the production of interleukin-1beta, matrix metalloproteinase 9, and prolyl 4-hydroxylase in rats with CIA compared with their control counterparts.

CONCLUSION

This study is the first to demonstrate the amelioration of arthritic symptoms by a novel, telomerase-dependent adenovirus in the rat CIA model, an experimental model that resembles human RA. In addition, the results suggest that because of its ability to induce cytolysis of SFs, this virus may be further explored as a therapeutic agent in patients with RA.

Perspectives on the use of gene therapy for chronic joint diseases

Advances in molecular and cellular biology have identified a wide variety of proteins including targeted cytokine inhibitors, immunomodulatory proteins, cytotoxic mediators, angiogenesis inhibitors, and intracellular signalling molecules that could be of great benefit in the treatment of chronic joint diseases, such as osteo- and rheumatoid arthritis. Unfortunately, protein-based drugs are difficult to administer effectively. They have a high rate of turnover, requiring frequent readministration, and exposure in non-diseased tissue can lead to serious side effects. Gene transfer technologies offer methods to enhance the efficacy of protein-based therapies, enabling the body to produce these molecules locally at elevated levels for extended periods. The proof of concept of gene therapies for arthritis has been exhaustively demonstrated in multiple laboratories and in numerous animal models. This review attempts to condense these studies and to discuss the relative benefits and limitations of the methods proposed and to discuss the challenges toward translating these technologies into clinical realities.

Aberrant prothymosin-alpha expression in human bladder cancer

OBJECTIVES

To investigate the prothymosin-alpha (PTMA) expression in human bladder cancer using tissue microarrays.

METHODS

Two tissue microarray slides of 50 bladder tumors and 42 paired normal adjacent tissues were investigated using immunohistochemical staining. The staining distribution was categorized as negative, nuclear, cytoplasmic, and mixed expression. Quantitative immunoreactivity was measured using image analysis, as represented by the integrated optical density for each tissue core.

RESULTS

In 36 of 42 normal adjacent tissues, positive PTMA immunoreactivity could be seen in some nuclei of the normal urothelial cells, but not, or only minimally, in the cytoplasm and underlying submucosal tissues. A statistically significant enhancement of PTMA expression was found in bladder tumors of each grade compared with the normal adjacent tissue (P < .0001 for normal adjacent tissues vs grade 1, 2, or 3 tumors, paired t test). Of 48 transitional cell carcinoma specimens, only 4 (8.3%) were graded as negative and 44 (91.7%) were positive for PTMA expression, including nuclear (n = 8), cytoplasmic (n = 12), and mixed expression (n = 24) patterns. A statistically significant correlation was found between high grade and mixed expression (P = 0.0020, chi(2) test).

CONCLUSIONS

Increased PTMA expression was found in human bladder cancers compared with the paired normal adjacent bladder tissue. The distribution of PTMA expression was changed in high-grade tumors. The clinical significance of such an aberrant PTMA expression in bladder cancer is worthy of additional investigation.

Gene therapy for arthritis

Arthritis is among the leading causes of disability in the developed world. There remains no cure for this disease and the current treatments are only modestly effective at slowing the disease's progression and providing symptomatic relief. The clinical effectiveness of current treatment regimens has been limited by short half-lives of the drugs and the requirement for repeated systemic administration. Utilizing gene transfer approaches for the treatment of arthritis may overcome some of the obstacles associated with current treatment strategies. The present review examines recent developments in gene therapy for arthritis. Delivery strategies, gene transfer vectors, candidate genes, and safety are also discussed.