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ABSTRACT: The efficacy of 1α,25-dihydroxyvitamin D3 (Vit-D) limits its topical use despite its profound effects on cellular differentiation, proliferation and immunomodulation. Therefore, in search for a more effective analog of Vit-D, in this study we have evaluated the antiproliferative and proapoptotic effects of 1α,25-Dihydroxyvitamin D3-3-bromoacetate (BE). Proliferation and apoptosis studies in normal human epidermal keratinocytes (NHEK) were done by MTT, CFSE dilution and Annexin V assays. Western blot and RT-PCR were done to determine its effect on signal transduction. A reconstructed human epidermis (RHE) model was used to further validate BE's therapeutic role in psoriasis. BE was significantly more potent than an equivalent concentration of Vit-D in inhibiting growth and survival of human keratinocytes. The antimitotic effect was found to be due to inhibition of phosphorylation of AKT and its downstream target, mTOR. In the RHE model, BE reversed IL22-induced psoriasiform changes more effectively than Vit-D. Interestingly, BE inhibited the IL22-induced gene expression of AKT1, MTOR, chemokines (IL-8, RANTES) and psoriasin (S100A7) more significantly than Vit-D. These results suggest the potential of BE as a prospective therapeutic agent for psoriasis.Journal of Investigative Dermatology accepted article preview online, 11 January 2013; doi:10.1038/jid.2013.3.
Journal of Investigative Dermatology 01/2013; · 6.31 Impact Factor
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ABSTRACT: Muscle inflammation and weakness are the key features of idiopathic inflammatory myopathies (IIMs). In addition IIMs are frequently associated with cutaneous and pulmonary involvement. In clinical practice the three common inflammatory myopathies we come across are polymyositis (PM), dermatomyositis (DM) and inclusion body myositis (IBM). The Bohan and Peter criteria combine clinical, laboratory, and pathologic features to define PM and DM. They did not recognize inclusion body myositis (IBM) or other inflammatory myopathies, such as granulomatous and eosinophilic myositis. Thus the disease spectrum is wide and IIMs are a heterogeneous group of autoimmune disorders. To address these issues in this article we have discussed the currently developing newer classifications of IIMs.
Indian Journal of Dermatology 09/2012; 57(5):366-70.
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ABSTRACT: Interleukin 22 (IL-22), a relatively new cytokine has been found to induce significant proliferation of human keratinocytes and fibroblast like synoviocytes (FLS) and thus plays an important role in the pathogenesis of autoimmune diseases like psoriasis and rheumatoid arthritis (RA) which are characterized by hyperproliferation of keratinocytes and FLS respectively. PI3K/Akt/mTOR signaling cascade plays crucial role in cell growth and survival. Therefore our objective was to see the regulatory role of PI3K/Akt/mTOR signaling cascade in IL-22 induced proliferation of keratinocytes and FLS.
Normal human epidermal keratinocytes (NHEK) and FLS were isolated from skin of healthy volunteer's undergone plastic surgery and synovial tissue of psoriatic arthritis (PsA) and RA patients respectively. IL-22 induced proliferation of NHEK and FLS was measured by MTT assay. Phosphorylation of Akt/mTOR was determined by western blot assay and further confirmed by real time polymerase chain reaction (RT-PCR).
We observed that IL-22 induced significant proliferation of NHEK and FLS which was effectively inhibited by dual kinase (PI3K/mTOR) inhibitor, NVP-BEZ235 and specific mTOR inhibitor, Rapamycin. In NHEK and FLS, IL-22 significantly induced phosphorylation of Akt and mTOR which was effectively blocked by Rapamycin and NVP-BEZ235. Further we did RT-PCR in NHEK and found that IL-22 significantly upregulated AKT1 and MTOR gene.
These results show that IL-22 induced proliferation of NHEK and FLS is dependent on PI3K/Akt/mTOR signaling pathway. This novel observation provides the scope to develop new therapeutics targeting PI3K/Akt/mTOR signaling pathway in autoimmune diseases like psoriasis and rheumatoid arthritis.
Cytokine 07/2012; 60(1):38-42. · 3.02 Impact Factor
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ABSTRACT: Psoriasis and psoriatic arthritis are chronic inflammatory diseases of unknown etiology, affecting 2-3% of the world population. Initially, psoriasis was thought to be a hyper-proliferation disorder of keratinocytes only, but as time passed, the role of immune system became more evident and now both diseases are considered autoimmune disorders. In last few years, the discovery of interleukin (IL)-23/Th17 axis in pathophysiology of psoriatic diseases shifts the cytokine paradigm from Th1 to Th17 cytokines, focused mainly on IL-17 and IL-22. Therapeutic experiences strongly support the use of cytokine antagonists as an important modality in the treatment of psoriatic arthritis and plaque psoriasis. Studies examining these therapeutic agents which target different steps of the psoriatic inflammatory cascade have also shown significant efficacy. The relatively new IL-23/Th17 axis in psoriatic diseases got more importance with the success of ustekinumab, a new monoclonal antibody against IL-12 and IL-23. In IL-17 and IL-22 knock-out and transgenic mouse models, it has been found that recombinant IL-23 fails to produce epidermal hyperplasia which resembles psoriasis. Also, some success in animal models of psoriasis was found with anti IL-17A and anti IL-22. More studies are needed to validate the efficacy and safety of these cytokine antagonists in psoriatic diseases. Using a historical perspective and a chess game as an analogy, the main objective of this review is to summarize the central role of some of these cytokines in psoriasis pathophysiology and to develop a strategic approach to new therapeutic weapons within the armamentarium of psoriasis treatment.
Clinical Reviews in Allergy & Immunology 03/2012; · 3.68 Impact Factor
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ABSTRACT: Interleukin-22 (IL-22) is a cytokine of IL-10 family with significant proliferative effect on different cell lines. Immunopathological role of IL-22 has been studied in rheumatoid arthritis (RA) and psoriasis. Here we are reporting the functional role of IL-22 in the inflammatory and proliferative cascades of psoriatic arthritis (PsA).
From peripheral blood and synovial fluid (SF) of PsA (n = 15), RA (n = 15) and osteoarthritis (OA, n = 15) patients, mononuclear cells were obtained and magnetically sorted for CD3+ T cells. Fibroblast like synoviocytes (FLS) were isolated from the synovial tissue of PsA (n = 5), RA (n = 5) and OA (n = 5) patients. IL-22 levels in SF and serum were measured by enzyme linked immunosorbent assay (ELISA). Proliferative effect of human recombinant IL-22 (rIL-22) on FLS was assessed by MTT (3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, a yellow tetrazole) and CFSE dilution (Carboxyfluorescein succinimidyl ester) assays. Expression of IL-22Rα1 in FLS was determined by western blot.
IL-22 levels were significantly elevated in SF of PsA patients (17.75 ± 3.46 pg/ml) compared to SF of OA (5.03 ± 0.39 pg/ml), p < 0.001. In MTT and CFSE dilution assays, rIL-22 (MTT, OD: 1.27 ± 0.06) induced significant proliferation of FLS derived from PsA patients compared to media (OD: 0.53 ± 0.02), p < 0.001. In addition, rIL-22 induced significantly more proliferation of FLS in presence of TNF-α. IL-22Rα1 was expressed in FLS of PsA, RA and OA patients. Anti IL-22R antibody significantly inhibited the proliferative effect of rIL-22. Further we demonstrated that activated synovial T cells of PsA and RA patients produced significantly more IL-22 than those of OA patients.
SF of PsA patients have higher concentration of IL-22 and rIL-22 induced marked proliferation of PsA derived FLS. Moreover combination of rIL-22 and TNF-α showed significantly more proliferative effect on FLS. IL-22Rα1 was expressed in FLS. Successful inhibition of IL-22 induced FLS proliferation by anti IL-22R antibody suggests that blocking of IL-22/IL-22R interaction may be considered as a novel therapeutic target for PsA.
Arthritis research & therapy 03/2012; 14(2):R65. · 4.27 Impact Factor
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ABSTRACT: Increasing evidence supports an important role for inflammation in all phases of atherosclerosis, from initiation of the fatty streak to final culmination in acute coronary syndromes. Numerous inflammatory biomarkers including cell adhesion molecules, cytokines, chemokines, and acute-phase reactants such as fibrinogen, serum amyloid A, and C-reactive protein (CRP) have been shown to predict cardiovascular (CVD) events. Several prospective studies have shown a consistent and robust relationship between levels of high-sensitivity CRP and the risk of future CVD events. Toll-like receptors are pattern recognition receptors and members of the innate immune system that contribute to inflammation and appear to play key roles in atherosclerosis. Lipoprotein-associated phospholipase A2 may also be an independent CVD risk factor. Psoriasis has been associated with an increasing risk for atherosclerosis, including coronary artery disease and stroke. Patients with psoriasis have a 5-year shorter life expectancy, most frequently due to CVD. Psoriasis is associated with a chronic inflammatory state and with elevated levels of CRP and other inflammatory cytokines and these may play a causative role in the increased risk of psoriatic patients for CVD. Patients with psoriasis may represent an emerging risk population and patients with moderate to severe psoriasis should be screened and aggressively treated for CVD risk factors.
Clinical Reviews in Allergy & Immunology 02/2012; · 3.68 Impact Factor
