Retinoic Acid Grafted to Hyaluronic Acid Activates Retinoid Gene Expression and Removes Cholesterol from Cellular Membranes.

All-trans-retinoic acid (atRA) is a potent ligand that regulates gene expression and is used to treat several skin disorders. Hyaluronic acid (HA) was previously conjugated with atRA (HA-atRA) to obtain a novel amphiphilic compound. HA-atRA forms micelles that incorporate hydrophobic molecules and facilitate their transport through the skin. The aim of this study was to determine the influence of HA-atRA on gene expression in skin cells and to compare it with that of unbound atRA. Gene expression was investigated using microarrays and a luciferase system with a canonical atRA promoter. HA-atRA upregulated gene expression similarly to atRA. However, HA-atRA activated the expression of cholesterol metabolism genes, unlike atRA. Further investigation using HPLC and filipin III staining suggested that the treated cells induced cholesterol synthesis to replenish the cholesterol removed from the cells by HA-atRA. HA modified with oleate (HA-C18:1) removed cholesterol from the cells similarly to HA-atRA, suggesting that the cholesterol removal stemmed from the amphiphilic nature of the two derivatives. HA-atRA induces retinoid signaling. Thus, HA-atRA could be used to treat skin diseases, such as acne and psoriasis, where the combined action of atRA signaling and anti-inflammatory cholesterol removal may be potentially beneficial.

Hyaluronan polymeric micelles for topical drug delivery.

Nanosized materials offer promising strategy for topical drug delivery due to their enhancing effect on drug percutaneous transport across the stratum corneum barrier. In this work, polymeric micelles made from hydrophobized hyaluronic acid (HA) were probed for skin delivery. Compared to non-polymeric micelle solutions containing similar drug amount, in vitro skin penetration analysis indicated 3 times larger deposition of drug in the epidermis and 6 times larger drug deposition in the dermis after 5h of topical treatment in Franz diffusion cells. The drug deposition was further increased with prolonged time of topical treatment. Laser confocal microscopy revealed the accumulation of both, the HA forming the vehicle and the payload, in the epidermis and dermis. Although fluorescent labeling of the HA would suggest co-transport of the HA and the drug, loading FRET pair dyes in the micellar core clearly demonstrated gradual micelle disruption with increasing skin depth. Transcellular penetration was the predominant pathway for the loaded drug. The HA polymeric micelles also demonstrated increased bioactivity of loaded compound in vitro and in vivo. In addition, the loaded micelles were found to be stable in cream formulations and thus they have great potential for topical applications for cosmetic and pharmaceutical purposes.

Dynamic alterations of bone marrow cytokine landscape of myelodysplastic syndromes patients treated with 5-azacytidine.

Myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal stem cell disorders characterized by ineffective hematopoiesis frequently progressing into acute myeloid leukemia (AML), with emerging evidence implicating aberrant bone marrow (BM) microenvironment and inflammation-related changes. 5-azacytidine (5-AC) represents standard MDS treatment. Besides inhibiting DNA/RNA methylation, 5-AC has been shown to induce DNA damage and apoptosis in vitro. To provide insights into in vivo effects, we assessed the proinflammatory cytokines alterations during MDS progression, cytokine changes after 5-AC, and contribution of inflammatory comorbidities to the cytokine changes in MDS patients. We found that IL8, IP10/CXCL10, MCP1/CCL2 and IL27 were significantly elevated and IL12p70 decreased in BM of MDS low-risk, high-risk and AML patients compared to healthy donors. Repeated sampling of the high-risk MDS patients undergoing 5-AC therapy revealed that the levels of IL8, IL27 and MCP1 in BM plasma were progressively increasing in agreement with in vitro experiments using several cancer cell lines. Moreover, the presence of inflammatory diseases correlated with higher levels of IL8 and MCP1 in low-risk but not in high-risk MDS. Overall, all forms of MDS feature a deregulated proinflammatory cytokine landscape in the BM and such alterations are further augmented by therapy of MDS patients with 5-AC.

Cytokine tumor necrosis factor-alpha A promoter gene polymorphism at position -308 G-->A and pediatric inflammatory bowel disease: implications in ulcerative colitis and Crohn's disease.

OBJECTIVES: Our pilot study aimed to determine the effect of tumor necrosis factor-alpha (TNF-alpha) 308 G-->A promoter single-nucleotide polymorphism in pediatric inflammatory bowel disease (IBD), its influence on inflammatory activity and the clinical manifestations. METHODS: We obtained genomic DNA from 164 subjects, 82 with long-standing IBD aged 8 to 18 years: 46 with Crohn disease (CD) and 36 with ulcerative colitis (UC). Eighty-two healthy children served as the control population. Genotyping was determined by using a restriction enzyme-based assay. TNF-alpha 308 G-->A polymorphism was assessed in terms of inflammatory (C-reactive protein [CRP]) and disease activity. The latter was assessed by the Pediatric Crohn's Disease Activity Index (PCDAI) and the Truelove index for CD and UC, respectively. RESULTS: Significant differences in TNF-alpha 308 A polymorphism were found between the IBD group and controls (P < 0.05) and the UC group and controls (P < 0.001). No differences were noted between TNF-alpha 308 A polymorphism and clinical characteristics in UC. The frequency of the -308 A allele of TNF was not different in CD compared with that in the control group. The frequency of TNF-alpha 308 A genotype was significantly higher in CD patients with predominantly stenosing/penetrating disease compared with patients without complications (P < 0.001) and healthy controls (P < 0.01). In CD patients, those carrying TNF -308 A had a significant increase in CRP (P < 0.05) and the PCDAI (P < 0.05). In CD, CRP levels strongly correlated with the PCDAI (r = 0.6150, P < 0.001). In UC, significant differences among the mean levels of CRP (P < 0.05) and disease activity (P < 0.001) related to TNF-alpha 308 A polymorphism were found. Allele distribution (odds ratio, 12.9; CI, 1.18-140.81, P < 0.001) and CRP serum levels (odds ratio, 1.020; CI, 1.00-1.04, P < 0.001) were independently associated with CD complications. CONCLUSIONS: Although not necessarily dictating IBD initiation, the TNF-alpha 308 A polymorphism may play a role in modifying the CD phenotype. The polymorphism may influence disease activity as well as more intense inflammatory activity in both forms of IBD and may modify the progression of chronic digestive tract inflammation.