Human Hsp40 proteins, DNAJA1 and DNAJA2, as potential targets of the immune response triggered by bacterial DnaJ in rheumatoid arthritis

Hsp40 proteins of bacterial and human origin are suspected to be involved in the pathogenesis of rheumatoid arthritis (RA). It has been shown that sera of RA patients contain increased levels of antibodies directed to bacterial and human Hsp40s. The aim of this work was to explore immunological similarities between the bacterial (DnaJ) and human (DNAJA1 and DNAJA2) Hsp40 proteins in relation to their possible involvement in the RA. Using polyclonal antibodies directed against a full-length DnaJ or its domains, against DNAJA1 and DNAJA2, as well as monoclonal anti-DnaJ antibodies, we found immunological similarities between the bacterial and human Hsp40s. Both ELISA and Western blotting showed that these similarities were not restricted to the conserved J domains but were also present in the C-terminal variable regions. We also found a positive correlation between the levels of the anti-DnaJ and anti-DNAJA1 antibodies in the sera of RA patients. This finding supports the molecular mimicry hypothesis that human Hsp40 could be the targets of antibodies originally directed against bacterial DnaJ in RA. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12192-013-0407-1) contains supplementary material, which is available to authorized users

Time- and Dose-Dependent Induction of HSP70 in Lemna minor Exposed to Different Environmental Stressors

The objective of this study was to examine the influence of different stressors, including cadmium (heavy metal), anthracene (polycyclic aromatic hydrocarbon—PAH) and chloridazon (herbicide), on population growth and biosynthesis of cytoplasmic HSP70 in Lemna minor (duckweed) in short (4 h)- and long (7 days)-term tests. A heat shock response was confirmed in Lemna exposed to high temperature: 35, 37.5, 40, or 42.5°C in short-term (4 h) treatments. The chemicals tested stimulated the biosynthesis of the cytoplasmic HSP70 protein in a concentration-dependent way (0.5–5 μM), higher in fronds exposed to lower doses of stressors. Additionally, production of HSP70 was greater after 4 h of incubation than after 7 days. The results suggest that HSP70 could be applied as a non-specific and sensitive detector of stress induced by different chemicals at concentrations below those that produce the type of response observed in classical cytotoxicity tests, such as growth inhibition

Heat Shock Protein 70 as a Double Agent Acting Inside and Outside the Cell: Insights into Autoimmunity

Heat shock proteins (Hsp) are a diverse group of constitutive and/or stress-induced molecules that are categorized into several classes on the basis of their molecular weight. Mammalian Hsp have been mostly regarded as intracellular chaperones that mediate a range of essential cellular functions, including proper folding of newly synthesized polypeptides, refolding of denatured proteins, protein transport, and stabilization of native proteins’ structures. The well-characterized and highly evolutionarily conserved, stress-inducible 70-kDa heat shock protein (Hsp70), is a key molecular chaperone that is overexpressed in the cell in response to stress of various origin. Hsp70 exhibits an immunosuppressive activity via, e.g., downregulation of the nuclear factor-kappa B (NF-κB) activation, and pharmacological induction of Hsp70 can ameliorate the autoimmune arthritis development in animal models. Moreover, Hsp70 might be passively or actively released from the necrotic or stressed cells, respectively. Highly immunogenic extracellular Hsp70 has been reported to impact both the innate and adaptive immune responses, and to be implicated in the autoimmune reaction. In addition, preclinical studies revealed that immunization with highly conserved Hsp70 peptides could be regarded as a potential treatment target for autoimmune arthritis, such as the rheumatoid arthritis, via induction of antigen-specific regulatory T helper cells (also called Treg). Here, a dual role of the intra- and extracellular Hsp70 is presented in the context of the autoimmune reaction

Regulatory effects of 1,25-dihydroxyvitamin D3 on vascular smooth muscle cells

Inflammatory response has been recognized as a central feature in the development and progression of atherosclerosis, and VSMCs (Vascular Smooth Muscle Cells) - the main cellular component of media, play an important role in this process. Many reports indicate that the biologically active vitamin D metabolite - 1,25-dihydroxyvitamin D3 (1,25(OH)2D3 = calcitriol), besides its well established role in calcium homeostasis, plays an essential role in the regulation of the inflammation process. The aim of this study was to determine the regulatory effects of calcitriol, applied at two supra-physiological doses (10 nM and 100 nM), in VSMC culture. Secretion of the pro-inflammatory cytokines, IL-6 and TNF-α, was significantly attenuated in calcitriol-treated VSMC culture, but the level of anti-inflammatory TGF-β was generally unchanged. Since in advanced atherosclerosis lesions several cell types, including VSMCs, overproduce the HSP70 chaperone protein, we also checked the effects of calcitriol on its synthesis. The presence of 1,25(OH)2D3 did not affect HSP70 synthesis under physiological conditions but the synthesis of HSP70 in VSMCs exposed to heat shock was significantly inhibited by calcitriol (=100 nM). We observed that 1,25(OH)2D3 induced SOD 1 activity, stimulated the expression of IκB-α, and did not influence the level of NF-κB-p65 in VSMCs. The results of our study suggest that 1,25(OH)2D3 may serve as a natural anti-inflammatory agent and may therefore play a beneficial role in the physiology of VSMC in some contexts of atherosclerosis

Heat Shock Protein 90 (Hsp90) and Hsp70 as Potential Therapeutic Targets in Autoimmune Skin Diseases

Over a hundred different autoimmune diseases have been described to date, which can affect every organ in the body, including the largest one, the skin. In fact, up to one-fifth of the world’s population suffers from chronic, noninfectious inflammatory skin diseases, the development of which is significantly influenced by an autoimmune response. One of the hallmarks of autoimmune diseases is the loss of immune tolerance, which leads to the formation of autoreactive lymphocytes or autoantibodies and, consequently, to chronic inflammation and tissue damage. The treatment of autoimmune skin diseases mainly focuses on immunosuppression (using, e.g., corticosteroids) but almost never leads to the development of permanent mechanisms of immune tolerance. In addition, current therapies and their long-term administration may cause serious adverse effects. Hence, safer and more effective therapies that bring sustained balance between pro- and anti-inflammatory responses are still desired. Both intra- and extracellular heat shock proteins (Hsps), specifically well-characterized inducible Hsp90 and Hsp70 chaperones, have been highlighted as therapeutic targets for autoimmune diseases. This review presents preclinical data on the involvement of Hsp90 and Hsp70 in modulating the immune response, specifically in the context of the treatment of selected autoimmune skin diseases with emphasis on autoimmune bullous skin diseases and psoriasis

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Inhibitory effects of heat shock protein 90 blockade on proinflammatory human Th1 and Th17 cell subpopulation

Vitamin D status in patients with rheumatoid arthritis: a correlation analysis with disease activity and progression, as well as serum IL-6 levels

Objectives. Recent epidemiological studies suggested an association between a poor vitamin D [25(OH)D] status, inflammatory mediators, and rheumatoid arthritis (RA). We have recently proposed that pro-inflammatory interleukin 6 (IL-6) may represent a good marker for disease activity of RA. The aim of this study was to investigate the relationship between serum 25(OH)D levels and disease activity, joint damage, as well as serum IL-6 levels in a Polish RA population. Materials and Methods. Serum 25(OH)D levels were measured in 35 female RA patients and 38 age- and gender-matched healthy controls. Statistical correlations between 25(OH)D levels and the disease activity score 28 (DAS 28), joint damage based on the Steinbrocker criteria, as well as serum IL-6 levels were performed. Results. There was no statistically significant difference between levels of 25(OH)D in RA (16.89±8.57 ng/ml) and healthy controls (14.12±7.51 ng/ml), and the vitamin D deficiency (<20 ng/ml) was found in 71.43% of RA patients and 73.68 % of healthy controls. While vitamin D status did not correlate with DAS 28 (r=0.265, p=0.149) and joint damage based on the Steinbrocker criteria (r=0.367, p=0.065), a positive correlation between 25(OH)D and IL-6 (r=0.537, p=0.002) was observed in RA. Conclusion. Although further studies on a larger group of patients will be needed to confirm the data presented here, it seems that hypovitaminosis D is common in the RA patients and middle-aged non-RA healthy women in the Polish population. 25(OH)D levels were similar in the RA patients and age- and gender-matched healthy controls, and were not associated with joint damage and disease activity in patients

Vitamin D status in patients with rheumatoid arthritis: a correlation analysis with disease activity and progression, as well as serum IL-6 levels

Objectives. Recent epidemiological studies suggested an association between a poor vitamin D [25(OH)D] status, inflammatory mediators, and rheumatoid arthritis (RA). We have recently proposed that pro-inflammatory interleukin 6 (IL-6) may represent a good marker for disease activity of RA. The aim of this study was to investigate the relationship between serum 25(OH)D levels and disease activity, joint damage, as well as serum IL-6 levels in a Polish RA population. Materials and Methods. Serum 25(OH)D levels were measured in 35 female RA patients and 38 age- and gender-matched healthy controls. Statistical correlations between 25(OH)D levels and the disease activity score 28 (DAS 28), joint damage based on the Steinbrocker criteria, as well as serum IL-6 levels were performed. Results. There was no statistically significant difference between levels of 25(OH)D in RA (16.89±8.57 ng/ml) and healthy controls (14.12±7.51 ng/ml), and the vitamin D deficiency (<20 ng/ml) was found in 71.43% of RA patients and 73.68 % of healthy controls. While vitamin D status did not correlate with DAS 28 (r=0.265, p=0.149) and joint damage based on the Steinbrocker criteria (r=0.367, p=0.065), a positive correlation between 25(OH)D and IL-6 (r=0.537, p=0.002) was observed in RA. Conclusion. Although further studies on a larger group of patients will be needed to confirm the data presented here, it seems that hypovitaminosis D is common in the RA patients and middle-aged non-RA healthy women in the Polish population. 25(OH)D levels were similar in the RA patients and age- and gender-matched healthy controls, and were not associated with joint damage and disease activity in patients

Cytokines of the Th1 and Th2 type in sera of rheumatoid arthritis patients; correlations with anti-Hsp40 immune response and diagnostic markers

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease which affects approximately 1% of the population worldwide. Recent research on the role of heat shock proteins (Hsps) in RA development indicates that they may have pro- or anti-inflammatory effect, most probably via modulating cytokine secretion. We investigated type Th1 (INFγ, TNFα, IL-2) and type Th2 (IL-10, IL-6, IL-4) cytokine levels in sera of RA patients and healthy controls, using flow cytometric bead array assay, and searched for correlations between the cytokine levels and serum antibodies against bacterial (DnaJ) and human (Hdj1, Hdj2 and Hdj3) Hsp40 proteins, as well as clinical and laboratory parameters. The levels of all cytokines studied were significantly increased in RA patients; the highest increase relative to healthy controls (7-fold) was observed for IL-6 and its levels correlated positively with the antibodies directed to DnaJ and to the C-terminal domain of Hdj2, and with diagnostic parameters (DAS 28, Steinbrocker RTG criteria, ARA/7, ESR, TEN, SW and GH). INFγ levels correlated negatively with DAS 28, ESR, TEN and SW. No correlations were found for TNFα, IL-2 or IL-4. Our results support the hypothesis of Hsp40 involvement in RA as well as indicate that IL-6 serum level is a good marker of the RA activity