Tacrolimus treatment of atopic eczema/dermatitis syndrome

Manipulating the expression of SARP family regulator BulZ and its target gene product to increase tacrolimus production

Tacrolimus (FK506), an effective immunosuppressant, is widely used in the treatment of autoimmune diseases. In this study, we identified that BulZ, a Streptomyces antibiotic regulatory protein (SARP) family regulator, acted as a positive regulator for spore differentiation and tacrolimus production. A knockout of bulZ resulted in a 47.5% decrease of tacrolimus production and a delay of spore differentiation. Using quantitative real-time PCR (qRT-PCR) analysis and electrophoretic mobility shift assays (EMSAs), it was found that BulZ directly activated the transcriptions of bulZ and bulS2, a putative γ-butyrolactone (GBL) synthetase, and bulS2 was shown to play a positive role in tacrolimus biosynthesis. Meanwhile, BulZ was able to indirectly regulate the transcriptions of the cluster-linked activator genes tcs7 and fkbN, as well as the GBL receptor gene bulR1. STSU_RS22595, which encoded a WhiB family transcriptional regulator, was found to be a previously unknown potential target gene of BulZ based on a whole-genome search of the conserved sequence (5'-TSVAVVVNVNBTSRAGNN-3') of the SARP-binding motifs. Although overexpression of STSU_RS22595 did not result in an obvious enhancement of tacrolimus yield, STSU_RS22595 might have important effects on the spore differentiation process. Finally, co-overexpression of bulZ and its target gene bulS2 improved tacrolimus production by 36% compared to the control strain, reaching 324 mg/L. The insights obtained in this study will help further elucidate the regulatory mechanism of tacrolimus biosynthesis and provide new avenues for further improvement of tacrolimus production.

FK506 suppresses hypoxia‑induced inflammation and protects tight junction function via the CaN‑NFATc1 signaling pathway in retinal microvascular epithelial cells

The present study aimed to identify whether FK506 suppresses hypoxia‑induced inflammation and protects tight junction function via the calcineurin‑nuclear factor of activated T‑cells 1 (CaN‑NFATc1) signaling pathway in mouse retinal microvascular endothelial cells (mRMECs). The mRMECs were treated with FK506 at different concentrations following the induction of hypoxia. Trans‑epithelial electrical resistance (TEER) and cell permeability were examined to measure the integrity of the tight junctions. The concentrations of inflammatory cytokines were measured using reverse transcription‑quantitative polymerase chain reaction analysis and enzyme‑linked immunosorbent assays. The protein expression levels of zonula occludens‑1 (ZO‑1) and nuclear factor of activated T‑cell 1 (NFATc1) were identified using immunofluorescent microscopy and western blot analysis. The TEER value was decreased following hypoxia, but increased following treatment with FK506 (1 and 10 µM) for 24 and 48 h. The protein expression of ZO‑1 was also increased following FK506 treatment for 24 h at 1 and 10 µM. By contrast, following treatment with FK506 (1 and 10 µM) for 24 and 48 h, the elevated cell permeability in the hypoxia group was significantly downregulated. Similarly, the concentrations of inflammatory cytokines, including cyclooxygenase‑2, inducible nitric oxide synthase, monocyte chemoattractant protein‑1, interleukin‑6, intercellular adhesion molecule‑1 and vascular cell adhesion molecule‑1, were downregulated following treatment with FK506 for 24 h at 1 and 10 µM. Following treatment with FK506, the level of total NFATc1 was downregulated and the level of phosphorylated NFATc1 was upregulated. Taken together, FK506 suppressed injury to the tight junctions and downregulated the expression of inflammatory cytokines in hypoxia‑induced mRMECs via the CaN‑NFATc1 signaling pathway. This suggests a potentially effective therapy for hypoxia‑induced retinal microangiopathy.

Oral evening primrose oil and borage oil for eczema

BACKGROUND

Eczema is a chronic inflammatory skin condition, which usually develops in early childhood. Many children outgrow this disorder as they reach secondary school age, and although It may improve with age, there is no cure. Constant itch makes life uncomfortable for those with this condition, no matter what age they are, so it may have a significant effect on a person's quality of life. Its prevalence seems to be increasing as populations move from rural locations to cities. Some people, who do not see an adequate improvement or fear side-effects of conventional medical products, try complementary alternatives to conventional treatment. This is a review of evening primrose oil (EPO) and borage oil (BO) taken orally (by mouth); these have been thought to be beneficial because of their gamma-linolenic acid content.

OBJECTIVES

To assess the effects of oral evening primrose oil or borage oil for treating the symptoms of atopic eczema.

SEARCH METHODS

We searched the following databases up to August 2012: Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 1946), EMBASE (from 1974), AMED (from 1985), and LILACS (from 1982). We also searched online trials registers and checked the bibliographies of included studies for further references to relevant trials. We corresponded with trial investigators and pharmaceutical companies to try to identify unpublished and ongoing trials. We performed a separate search for adverse effects of evening primrose oil and borage oil in November 2011.

SELECTION CRITERIA

All randomised controlled, parallel, or cross-over trials investigating oral intake of evening primrose oil or borage oil for eczema.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied eligibility criteria, assessed risk of bias, and extracted data. We pooled dichotomous outcomes using risk ratios (RR), and continuous outcomes using the mean difference (MD). Where possible, we pooled study results using random-effects meta-analysis and tested statistical heterogeneity using both the Chi(²) test and the I(²) statistic test. We presented results using forest plots with 95% confidence intervals (CI).

MAIN RESULTS

A total of 27 studies (1596 participants) met the inclusion criteria: 19 studies assessed evening primrose oil, and 8 studies assessed borage oil. For EPO, a meta-analysis of results from 7 studies showed that EPO failed to significantly increase improvement in global eczema symptoms as reported by participants on a visual analogue scale of 0 to 100 (MD -2.22, 95% CI -10.48 to 6.04, 176 participants, 7 trials) and a visual analogue scale of 0 to 100 for medical doctors (MD -3.26, 95% CI -6.96 to 0.45, 289 participants, 8 trials) compared to the placebo group.Treatment with BO also failed to significantly improve global eczema symptoms compared to placebo treatment as reported by both participants and medical doctors, although we could not conduct a meta-analysis as studies reported results in different ways. With regard to the risk of bias, the majority of studies were of low risk of bias; we judged 67% of the included studies as having low risk of bias for random sequence generation; 44%, for allocation concealment; 59%, for blinding; and 37%, for other biases.

IMPLICATIONS FOR PRACTICE

Oral borage oil and evening primrose oil lack effect on eczema; improvement was similar to respective placebos used in trials. Oral BO and EPO are not effective treatments for eczema.In these studies, along with the placebos, EPO and BO have the same, fairly common, mild, transient adverse effects, which are mainly gastrointestinal.The short-term studies included here do not examine possible adverse effects of long-term use of EPO or BO. A case report warned that if EPO is taken for a prolonged period of time (more than one year), there is a potential risk of inflammation, thrombosis, and immunosuppression; another study found that EPO may increase bleeding for people on Coumadin® (warfarin) medication.

IMPLICATIONS FOR RESEARCH

Noting that the confidence intervals between active and placebo treatment are narrow, to exclude the possibility of any clinically useful difference, we concluded that further studies on EPO or BO for eczema would be hard to justify.This review does not provide information about long-term use of these products.

Tacrolimus (FK506) prevents early retinal neovascularization in streptozotocin-induced diabetic mice

Diabetic retinopathy is a complex disease that has potential involvement of inflammatory in its pathogenesis. We hypothesized that tacrolimus (FK506), one of the potent immunosuppressive agent, could be effective against diabetic retinopathy, which involves significant inflammation. The aim of the present study was to investigate the effects of FK506 in early retinal changes of streptozotocin-induced diabetic mice. The effect of FK506 treatment (10 μg per eye for one week) was evaluated by TNF-a, VEGF, iNOS and COX-2 protein levels measurement, neovascularization, and the activation of NF-kB in the retina. Increased amounts of cytokines, neovascularization, inflammatory markers and activation of NF-kB were observed in retina from diabetic mice. FK506 treatment significantly lowered retinal TNF-a, VEGF, iNOS and COX-2. Further, treatment with FK506 significantly suppressed diabetes-related neovascularization, as well as the activation of NF-kB. These data demonstrated that FK506 attenuates the degree of retinal inflammation and preserving the neovascularization in early diabetic mice.

Topical calcineurin inhibitors in atopic dermatitis: a systematic review and meta-analysis

OBJECTIVES

To build a critical appraisal of the available literature to evaluate the effectiveness of topical calcineurin inhibitors in treatment of atopic dermatitis (AD), in comparison to topical corticosteroids (TCs) and/or placebo.

REVIEW METHODS

DESIGN

systematic review and meta-analysis.

DATA SOURCES

electronic search of MEDLINE Pubmed along the last 10 years (1997-2006).

STUDY SELECTION

randomized control trials of TCIs reporting efficacy outcomes, in comparison to TCs or vehicle (placebo) or both.

DATA SYNTHESIS

of 210 articles, 19 studies were included, 10 for tacrolimus and 9 for pimecrolimus, involving 7378 patients of whom 2771 applied tacrolimus, 1783 applied pimecrolimus, and 2824 were controls. Both drugs were significantly more effective than a vehicle. However, two long-term trials comparing demonstrated the value of pimecrolimus in reduction of flares and steroid-sparing effect after 6 months. Compared to TCs, both 0.1% and 0.03% tacrolimus ointments were as effective as moderate potency TCs, and more effective than a combined steroid regimen. Tacrolimus was more effective than mild TCs.

CONCLUSIONS

TCIs in AD are more effective than placebo. Although less effective than TCs, pimecrolimus has its value in long-term maintenance and as a steroid-sparing agent in AD, whenever used early enough, at first appearance of erythema and/or itching. In treatment of moderate to severe AD, topical tacrolimus is as effective as moderately potent TCs, and more effective than mild preparations. Chronic AD lesions of the face and flexures are the most justified indication for topical calcineurin inhibitors.

Role of bacterial pathogens in atopic dermatitis

The skin of atopic dermatitis (AD) patients exhibits a striking susceptibility to colonization and infection with Staphylococcus aureus. This review summarizes our understanding about the role of S. aureus in AD. Indeed, S. aureus colonization is both a cause and a consequence of allergic skin inflammation. The mechanisms that allergic skin inflammation of AD promotes the increase of S. aureus colonization include skin barrier dysfunction, increased synthesis of the extracellular matrix adhesins for S. aureus, and defective innate immune responses due to decreased production of endogenous antimicrobial peptides. On the other hand, the exotoxins secreted by S. aureus are superantigens. Staphylococcal superantigens (SsAgs) may penetrate the skin barrier and contribute to the persistence and exacerbation of allergic skin inflammation in AD through the stimulation of massive T cells, the role of allergens, direct stimulation of antigen-presenting cells and keratinocytes, the expansion of skin-homing cutaneous lymphocyte-associated antigen-positive T cells, and the augmentation of allergen-induced skin inflammation. SsAgs also induce corticosteroid resistance. In therapeutic interventions, anti-inflammatory therapy alone is very effective in reducing S. aureus colonization on the skin, but antibiotic treatment alone is unable to improve the allergic skin inflammation of AD. Therefore, we recommend the combination therapy of anti-inflammatory drugs and antibiotics in the AD patients with secondary bacterial infection, exacerbated AD, or poorly controlled AD. However, when AD is well controlled by anti-inflammatory drugs alone, we do not recommend the antibiotic therapy.

Relative impact of CD4+CD25+ regulatory T cells and tacrolimus on inhibition of T-cell proliferation in patients with atopic dermatitis

BACKGROUND

It has been established recently that CD4+CD25+ regulatory T cells (Tregs) play an important role in controlling various immune responses. Immunosuppressive drugs are often used to treat immune dysregulation but are frequently associated with undesirable side-effects.

OBJECTIVES

We examined the suppressive capacity of circulating Tregs in patients with atopic dermatitis (AD). Combined effects of Tregs and tacrolimus on the inhibition of T-cell proliferation in vitro were also assessed.

METHODS

CD4+CD25+ and CD4+CD25- T cells were isolated from peripheral blood mononuclear cells using immunomagnetic beads. CD4+CD25- T cells were stimulated with purified protein derivative (PPD) or house dust mite allergen (Der p1) for 6 or 7 days, respectively. A dose range of tacrolimus and CD4+CD25+ T cells were added separately, or together. Proliferation was measured by (3)H-thymidine incorporation.

RESULTS

CD4+CD25+ T cells from normal controls and patients with AD are anergic and inhibit the proliferation of CD4+CD25- T cells in response to PPD and Der p1 in vitro in a dose-dependent manner. Addition of tacrolimus and Tregs together showed significantly stronger inhibition of proliferation than either on their own. This was true for both antigens and both in normal controls and in patients with AD.

CONCLUSIONS

CD4+CD25+ T cells in patients with AD have normal suppressive activity compared with healthy controls. Tregs and tacrolimus have additive effects on the inhibition of proliferation in response to PPD and Der p1.

Atopic dermatitis--more than a simple skin disorder

PURPOSE

To describe atopic dermatitis (AD) in relation to a case study, the diagnostic criteria, complications, prevalence, future implications, and management for the primary care provider.

DATA SOURCES

Extensive literature review on the condition, supplemented with an actual case study.

CONCLUSIONS

Although there are many scientific studies done on AD, the exact pathogenesis and cure for this condition are still to be discovered. It is usually chronic and has some fatal sequelae in those who have been exposed to viral infections. Asthma, allergic rhinitis (AR), and AD are considered the atopic triad. Further studies that may help improve medical providers' understanding of AD are going on and offer hope to those afflicted by this disorder.

IMPLICATIONS FOR PRACTICE

Children over 5 years old may have outgrown their symptoms, so it is best to diagnose this condition at an early age to provide better management outcomes. Because it is part of an atopic triad, the nurse practitioner must think beyond the presenting skin condition to consider possible respiratory system conditions. AD may herald the onset of asthma and AR.

FK506 suppresses E-selectin, ICAM-1 and VCAM-1 expression on vascular endothelial cells by inhibiting tumor necrosis factor alpha secretion from peripheral blood mononuclear cells

FK506 suppresses activation of T cells; however, it down-regulates E-selectin, ICAM-1 and VCAM-1 expression in inflamed tissues. In this study, we investigated the effect of FK506 on expression of those adhesion molecules on human vascular endothelial cells (HMVEC). Culture supernatant from peripheral blood mononuclear cells (PBMC) stimulated with anti-CD3 plus anti-CD2 antibodies effectively induced the expression of E-selectin, ICAM-1 and VCAM-1 on HMVEC, and treatment with FK506 down-regulated their expression. Culture supernatant contained tumor necrosis factor (TNF) alpha and interleukin (IL)-1beta, which effectively induced adhesion molecules, and FK506 suppressed both cytokine secretions. TNFalpha content in culture supernatant was parallel to the induction of adhesion molecules by the culture supernatant. IL-1beta content was not enough to induce those adhesion molecules. Anti-TNFalpha antibody completely inhibited those expressions. FK506 did not inhibit either TNFalpha- or IL-1beta-induced expression of adhesion molecules, or viability of HMVEC. These results indicate that FK506 suppresses migration of inflammatory cells through the inhibition of TNFalpha secretion from leukocytes.

Novel cyclosporin derivatives featuring enhanced skin penetration despite increased molecular weight

Topical cyclosporin A (CsA, 1) is not effective in the treatment of skin diseases, due to its low skin penetration. Following a prodrug strategy, a series of novel derivatives of 1 and of 2-[O-(2-hydroxyethyl)-d-Ser(8)]-CsA (SDZ IMM 125, 5) with potentially enhanced skin penetration properties were synthesized, in order to achieve higher levels of the active parent drugs in the skin. Permeation through skin and prodrug/drug levels in the skin were measured in vitro using rat and human skin. Introduction of a polar side chain, either in the form of a positively charged quaternary amine, a negatively charged phosphate or sulfate, or an amphiphilic phosphocholine moiety, generally increased permeability. Maximal increase in permeability through skin relative to CsA was up to 300-fold with rat skin, and up to 16-fold with human skin. Penetration into skin, as evaluated by measurement of prodrug/drug concentrations in the skin after 48 h, could be enhanced up to 14-fold (rat and human skin). Increases of permeation rates and skin concentrations showed no strict correlation. Using the phosphate 10 as prodrug, a 2.5-fold higher concentration of the active parent compound (5) could be achieved in rat skin as when administering 5 itself. The results demonstrate that in contrast with the '500 Dalton rule', which postulates poor skin penetration of molecules larger than 500 Da, high skin permeation can be achieved also with compounds of a molecular weight in the range between 1200 and 1600 Da. Results also indicate that in principle higher skin levels of active drug can be attained with a prodrug strategy in this class of compounds.

Pimecrolimus: a review of its use in atopic dermatitis

Pimecrolimus (Elidel) is a topically active, nonsteroid, calcineurin inhibitor that has shown efficacy in controlling symptoms of atopic dermatitis in adult and pediatric patients. Topical pimecrolimus 1% cream is approved in the US for the short-term and intermittent long-term treatment of mild-to-moderate atopic dermatitis in non-immunocompromised patients aged >/=2 years who do not respond well to, or may have adverse effects with, conventional treatments. Pimecrolimus 1% cream is an effective and well tolerated treatment for atopic dermatitis in infants, children, adolescents, and adults. Pimecrolimus is effective at reducing the incidence of disease flares and, thus, the need for rescue treatment with topical corticosteroids. The drug also improves the health-related quality of life (HR-QOL) of children and adolescents, and improves the QOL of parents of children with atopic dermatitis. Furthermore, pimecrolimus does not cause skin atrophy, a problem commonly associated with topical corticosteroids, and is not associated with clinically relevant systemic adverse events. Thus, topical pimecrolimus 1% cream is an effective treatment option for the management of mild-to-moderate atopic dermatitis.