Potencies of topical glucocorticoids to mediate genomic and nongenomic effects on human peripheral blood mononuclear cells

Nongenomic glucocorticoid effects and their mechanisms of action in vertebrates

Glucocorticoids (GC) act on multiple organ systems to regulate a variety of physiological processes in vertebrates. Due to their immunosuppressive and anti-inflammatory actions, glucocorticoids are an attractive target for pharmaceutical development. Accordingly, they are one of the most widely prescribed classes of therapeutics. Through the classical mechanism of steroid action, glucocorticoids are thought to mainly affect gene transcription, both in a stimulatory and suppressive fashion, regulating de novo protein synthesis that subsequently leads to the physiological response. However, over the past three decades multiple lines of evidence demonstrate that glucocorticoids may work through rapid, nonclassical mechanisms that do not require alterations in gene transcription or translation. This review assimilates evidence across the vertebrate taxa on the diversity of nongenomic actions of glucocorticoids and the membrane-associated cellular mechanisms that may underlie rapid glucocorticoid responses to include potential binding sites characterized to date.

How to mechanistically explain the CONDOR study data

Results of the CONDOR study suggest that in osteoarthritis and rheumatoid arthritis patients at elevated risk of gastrointestinal (GI) events, treatment with celecoxib, a cyclooxygenase (COX)-2 selective non-steroidal anti-inflammatory drug (NSAID), demonstrated significantly lower toxicity in the upper and lower (GI) tract when compared to the non-selective NSAID diclofenac plus a proton-pump-inhibitor (PPI), omeprazole. According to current knowledge, traditional NSAIDs (tNSAIDs) as non-selective COX-inhibitors exert their damaging effects on the upper GI tract, largely by reduction of the COX-1 related synthesis of gastro-protective prostaglandins. Thus, the question arises, how NSAIDs do exert their damaging effects especially in the lower GI tract and how to explain the reduced risk of a COX-2 selective inhibitor, celecoxib. Here we hypothesize, that the toxicity of celecoxib on enteral mucosa cells is lower than observed with other NSAIDs, and can be explained COX-independently by typical physicochemical properties of the NSAID substances (e.g., acidic, lipophilic, amphiphilic, surfactant properties). As a consequence these features account for differences in (1) uncoupling effects on mitochondria, (2) effects on cell membrane integrity, and/or (3) formation of "toxic micelles" with bile salts. The evidence for these differences is mainly based on experimental findings. However, several phenomena show differences in extent (e.g., uncoupling effects). The reduced toxicity appears to be rather a substance-specific characteristic. This is an unconditional reason to carry on investigating these phenomena in experimental and large-scale clinical trials.

Clobetasol propionate (Dermovate) gives new opportunities in the treatment ofdermatoses

The author provides a review of literature covering studies of the efficacy and safety of a very powerful topical corticosteroid - clobetasol propionate (Dermovate). It surpasses most topical glucocorticoids by its action and efficacy for steroid-responsive dermatoses. The drug has several forms convenient for use for different localizations. It is a drug of choice for medium and severe psoriasis. It is efficient in treatment of a wide range of torpid dermatoses as well as dermatoses resistant to other topical drugs. This drug is safe under the condition of its reasonable administration. The development of serious complications is possible only in case of long-term administration of extremely high doses.

Rapid onset of bronchodilation with formoterol/beclomethasone Modulite and formoterol/budesonide Turbuhaler as compared to formoterol alone in patients with COPD

In the present study, we examined whether there is a difference in the onset of bronchodilatation between formoterol/beclomethasone 12/200 μg Modulite and formoterol/budesonide 9/320 μg Turbuhaler in patients with COPD. We enrolled 28 patients with stable COPD. Both formoterol/beclomethasone and formoterol/budesonide elicited a larger mean FEV₁-AUC₀₋₁₅min than formoterol alone, whereas there was no significant difference between their FEV₁-AUC₀₋₁₅min. Also the change in FEV₁ 15 min after inhalation of formoterol/beclomethasone combination or formoterol/budesonide combination was greater than that induced by formoterol alone. This study confirms the rapid effect of the inhaled corticosteroid component when combined with formoterol and indicates that the onset of bronchodilation of formoterol/beclomethasone Modulite and formoterol/budesonide Turbuhaler are similar and greater than formoterol alone in patients with COPD.

Non-genomic rapid inhibition of Na+/H+-exchange 1 and apoptotic immunosuppression in human T cells by glucocorticoids

Glucocorticoids (GCs) have been employed as immunosuppressive agents for many years. However, it is still unclear how GCs instantly uncouple T cells from acute stressful inflammatory. In terms of time scale, the genomic activity of the classic GC receptor cannot fulfill this role under crisis; but a rapid non-genomic response can. In a previous study, intracellular acidification was found to be due to a rapid non-genomic inhibition of Na(+)/H(+)-exchange 1 (NHE1) and this event led to the immunosuppression of T cell proliferation by progesterone. The aim of this study was to examine whether there is a rapid acidification response caused by an inhibition of NHE1 activity and to explore the differential non-genomic effect on immunosuppression of hydrocortisone and dexamethasone. The IC(50) values for NHE1-dependent pH(i) recovery by hydrocortisone and dexamethasone are 250 and 1 nM, respectively. Co-stimulation of GCs with phytohemagglutinin (PHA) is able to inhibit PHA-induced IL-2 secretion, IL-4 secretion, and T-cell proliferation. Furthermore, apoptosis in PHA-activated T cells is not induced by hydrocortisone but by dexamethasone. The mechanism of immunosuppression on proliferation by dexamethasone was found to be different of hydrocortisone and seems to involve cytotoxicity against T cells. Moreover, apoptosis induced by dexamethasone and impermeable dexamethasone-bovine serum albumin suggests that the apoptotic immunosuppression occurs through both the plasma membrane and cytoplasmic sites. The rapid inhibitory responses triggered by GCs would seem to release T cells instantly when an acute stress-related response is needed. Nonetheless, the apoptotic immunosuppression by dexamethasone is attributable to its severe cytotoxicity.

The role of oral beclometasone dipropionate in the treatment of gastrointestinal Graft-versus-Host Disease

Graft-versus-host disease (GVHD) after allogeneic stem-cell transplantation causes significant morbidity and mortality. An important site of GVHD is the gastrointestinal (GI) tract because development of acute GI GVHD is prognostic of overall survival. The standard of care to treat acute GI GVHD is systemic corticosteroids and immunosuppressants; however, the use of these therapies can cause life-threatening opportunistic infections. To limit the adverse effects of systemic immunosuppression, the topically active corticosteroid beclometasone dipropionate has been investigated in case studies and in randomized placebo-controlled trials for the treatment of acute GI GVHD. In this review, we appraise these studies with beclometasone dipropionate, and discuss future randomized studies to clarify the role of beclometasone dipropionate for the treatment and prevention of acute GVHD. At present, more data are required before the addition of beclometasone dipropionate to systemic corticosteroids for the treatment of acute GVHD can be considered the standard of care.

Oral beclomethasone dipropionate: a topically active corticosteroid for the treatment of gastrointestinal graft-versus-host disease following allogeneic hematopoietic cell transplantation

Beclomethasone dipropionate (BDP) is a topically active anti-inflammatory corticosteroid. Oral BDP is metabolized in the intestine to a potent metabolite, 17-beclomethasone monopropionate (17-BMP). An oral formulation (orBec; DOR BioPharma), consisting of a gastric release and an enteric-coated pill, was studied in patients with acute gastrointestinal graft-versus-host disease, an inflammatory disorder that is common after allogeneic hematopoietic cell transplantation. Randomized trials demonstrated that orBec is safe and effective in treating acute gastrointestinal graft-versus-host disease (GVHD) when used with a short induction course of prednisone, reducing the risk of GVHD treatment failure by > 60% and reducing mortality 1 year after randomization by 45%, with fewer deaths due to infection and recurrent malignancy. The type of conditioning and the type of donor had no effect on the frequency of GVHD treatment failure during the 80-day study period; the greatest benefit in terms of survival was among patients who had received reduced-intensity conditioning therapy and among those who received a graft from other than a human leukocyte antigen-matched sibling. orBec controls the intestinal inflammatory process of GVHD and avoids prolonged exposure to prednisone, which is the present standard of care. Oral BDP is the only therapy to be studied in the last 30 years to effectively treat acute GVHD and reduce mortality.

Recognition of Glycoprotein Peroxidase via Con A-Carrying Self-Assembly Layer on Gold

We have successfully fabricated a self-assembled layer of concanavalin A (Con A) on a gold surface for recognition of glycoproteins. The type IV Con A is covalently bound to 11-mercaptoundecanoic acid (MUA) on gold with a 2-(5-norbornene-2,3-dicarboximido)-1,1,3,3-tetramethyluronium tetrafluoroborate (TNTU) linkage. The binding interaction between glycoproteins and self-assembled Con A is studied using horseradish peroxidase (HRP) as a model glycoprotein. Voltammetric, electrochemical impedance studies, and photometric activity measurements show the presence of both specific and nonspecific bindings of HRP to the Con A interface. The specific binding is attributed to the Con A-sugar interaction where Con A selectively recognizes the glycosylation sites of HRP. The catalytic current of the HRP-loaded electrode, because of catalytic oxidation of thionine in the presence of hydrogen peroxide (H2O2), is found to be proportional to the HRP concentrations in the incubation solution. A linear correlation coefficient of 0.993 was obtained over a wide HRP concentration range of 12.5 microg/mL to 1 mg/mL. The approach described in this study provides a simple yet selective means to immobilize glycoproteins on a solid support. The specific binding achieved is desirable in biosensor fabrication, glycoprotein separation, recognition, and purification as well as in drug-releasing systems.