Activation of Free Fatty Acid Receptor 4 (FFA4) Ameliorates Ovalbumin-Induced Allergic Asthma by Suppressing Activation of Dendritic and Mast Cells in Mice

Epidemiological and clinical studies have suggested that intake of n-3 polyunsaturated fatty acids (PUFA) reduces the incidence of allergic airway diseases and improves pulmonary function in patients with allergic asthma. However, the pharmacological targets of PUFA have not been elucidated upon. We investigated whether free fatty acid receptor 4 (FFA4, also known as GPR120) is a molecular target for beneficial PUFA in asthma therapy. In an ovalbumin (OVA)-induced allergic asthma model, compound A (a selective agonist of FFA4) was administrated before OVA sensitization or OVA challenge in FFA4 wild-type (WT) and knock-out (KO) mice. Compound A treatment of RBL-2H3 cells suppressed mast cell degranulation in vitro in a concentration-dependent manner. Administration of compound A suppressed in vivo allergic characteristics in bronchoalveolar lavage fluid (BALF) and lungs, such as inflammatory cytokine levels and eosinophil accumulation in BALF, inflammation and mucin secretion in the lungs. Compound A-induced suppression was not only observed in mice treated with compound A before OVA challenge, but in mice treated before OVA sensitization as well, implying that compound A acts on mast cells as well as dendritic cells. Furthermore, this suppression by compound A was only observed in FFA4-WT mice and was absent in FFA4-KO mice, implying that compound A action is mediated through FFA4. Activation of FFA4 may be a therapeutic target of PUFA in allergic asthma by suppressing the activation of dendritic cells and mast cells, suggesting that highly potent specific agonists of FFA4 could be a novel therapy for allergic asthma.     

基于超高效液相色谱的改良直接肽反应试验预测化学物皮肤致敏性

建立基于超高效液相色谱改良直接肽反应试验预测化学物致敏性并提高检测效率和通量。选择8种已知皮肤致敏性化合物与半胱氨酸多肽或赖氨酸多肽反应24 h,通过基于超高效液相色谱或高效液相色谱的检测系统计算得到多肽消耗率预测受试物皮肤致敏性。结果显示,基于超高效液相色谱的改良直接多肽反应试验能正确区分8种化学物为皮肤致敏物或非致敏物,且节省检测时间,提高检测通量,同时色谱峰分离度更高。     

DNA Methylation Levels in Mononuclear Leukocytes from the Mother and Her Child Are Associated with IgE Sensitization to Allergens in Early Life

DNA methylation changes may predispose becoming IgE-sensitized to allergens. We analyzed whether DNA methylation in peripheral blood mononuclear cells (PBMC) is associated with IgE sensitization at 5 years of age (5Y). DNA methylation was measured in 288 PBMC samples from 74 mother/child pairs from the birth cohort ALADDIN (Assessment of Lifestyle and Allergic Disease During INfancy) using the HumanMethylation450BeadChip (Illumina). PBMCs were obtained from the mothers during pregnancy and from their children in cord blood, at 2 years and 5Y. DNA methylation levels at each time point were compared between children with and without IgE sensitization to allergens at 5Y. For replication, CpG sites associated with IgE sensitization in ALADDIN were evaluated in whole blood DNA of 256 children, 4 years old, from the BAMSE (Swedish abbreviation for Children, Allergy, Milieu, Stockholm, Epidemiology) cohort. We found 34 differentially methylated regions (DMRs) associated with IgE sensitization to airborne allergens and 38 DMRs associated with sensitization to food allergens in children at 5Y (Sidak p ≤ 0.05). Genes associated with airborne sensitization were enriched in the pathway of endocytosis, while genes associated with food sensitization were enriched in focal adhesion, the bacterial invasion of epithelial cells, and leukocyte migration. Furthermore, 25 DMRs in maternal PBMCs were associated with IgE sensitization to airborne allergens in their children at 5Y, which were functionally annotated to the mTOR (mammalian Target of Rapamycin) signaling pathway. This study supports that DNA methylation is associated with IgE sensitization early in life and revealed new candidate genes for atopy. Moreover, our study provides evidence that maternal DNA methylation levels are associated with IgE sensitization in the child supporting early in utero effects on atopy predisposition.     

胰岛素经皮给药研究的新进展

经皮给药是胰岛素一种理想的给药方式,但是皮肤角质层的阻力、胰岛素分子在皮肤中的积累以及促渗方法的安全性等限制了胰岛素的经皮给药。作者分析了胰岛素经皮给药的优势和存在的问题,从减小角质层阻力、强化被动扩散和应用传递体为透皮给药载体3个方面,综述了近几年来国内外在胰岛素的经皮给药的研究上取得的最新进展,指出了存在的问题和研究的趋势。     

Traumatic Acid Reduces Oxidative Stress and Enhances Collagen Biosynthesis in Cultured Human Skin Fibroblasts

Traumatic acid (TA) is a plant hormone (cytokinin) that in terms of chemical structure belongs to the group of fatty acids derivatives. It was isolated from Phaseolus vulgaris. TA activity and its influence on human cells and organism has not previously been the subject of research. The aim of this study was to examine the effects of TA on collagen content and basic oxidative stress parameters, such as antioxidative enzyme activity, reduced glutathione, thiol group content, and lipid peroxidation in physiological conditions. The results show a stimulatory effect of TA on tested parameters. TA caused a decrease in membrane phospholipid peroxidation and exhibited protective properties against ROS production. It also increases protein and collagen biosynthesis and its secretion into the culture medium. The present findings reveal that TA exhibits multiple and complex activity in fibroblast cells in vitro. TA, with its activity similar to unsaturated fatty acids, shows antioxidant and stimulatory effects on collagen biosynthesis. It is a potentially powerful agent with applications in the treatment of many skin diseases connected with oxidative stress and collagen biosynthesis disorders.     

Skin permeability of compounds loaded within dissolving microneedles dependent on composition of sodium hyaluronate and carboxymethyl cellulose

Dissolving microneedles are transdermal delivery systems designed to mechanically penetrate the skin and fully dissolve in the skin in a minimally invasive manner. In this study, the skin permeability of compounds encapsulated in microneedles was controlled by changing the composition of microneedle materials. Sodium hyaluronate (SH) and carboxymethyl cellulose (CMC) were chosen as structural materials and amylopectin was used to increase the mechanical strength of microneedles. To determine the effect of microneedle composition on skin permeability, microneedle properties such as mechanical strength and solubility were investigated according to various compositions of SH and CMC. When the CMC fraction in the needle increased, the mechanical strength of the microneedle increased, leading to high skin permeability of rhodamine B, a model compound. Using microneedles, significantly higher skin permeability of niacinamide was also obtained. These results indicate that the microneedles developed in this study improved the skin permeability of compounds loaded in the needle, and the skin permeability could be tuned by changing the composition of microneedle materials.     

Effect of gadolinium chloride on liver regeneration following thioacetamide-induced necrosis in rats

Gadolinium chloride (GD) attenuates drug-induced hepatotoxicity by selectively inactivating Kupffer cells. The effect of GD was studied in reference to postnecrotic liver regeneration induced in rats by thioacetamide (TA). Rats, intravenously pretreated with a single dose of GD (0.1 mmol/Kg), were intraperitoneally injected with TA (6.6 mmol/Kg). Hepatocytes were isolated from rats at 0, 12, 24, 48, 72 and 96 h following TA intoxication, and samples of blood and liver were obtained. Parameters related to liver damage were determined in blood. In order to evaluate the mechanisms involved in the post-necrotic regenerative state, the time course of DNA distribution and ploidy were assayed in isolated hepatocytes. The levels of circulating cytokine TNFα was assayed in serum samples. TNFα was also determined by RT-PCR in liver extracts. The results showed that GD significantly reduced the extent of necrosis. The effect of GD induced noticeable changes in the post-necrotic regeneration, causing an increased percentage of hepatocytes in S phase of the cell cycle. Hepatocytes increased their proliferation as a result of these changes. TNFα expression and serum level were diminished in rats pretreated with GD. Thus, GD pre-treatment reduced TA-induced liver injury and accelerated postnecrotic liver regeneration. No evidence of TNFα implication in this enhancement of hepatocyte proliferation and liver regeneration was found. These results demonstrate that Kupffer cells are involved in TA-induced liver damage, as well as and also in the postnecrotic proliferative liver states.     

Previous Influenza Infection Exacerbates Allergen Specific Response and Impairs Airway Barrier Integrity in Pre-Sensitized Mice

In this study we assessed the effects of antigen exposure in mice pre-sensitized with allergen following viral infection on changes in lung function, cellular responses and tight junction expression. Female BALB/c mice were sensitized to ovalbumin and infected with influenza A before receiving a second ovalbumin sensitization and challenge with saline, ovalbumin (OVA) or house dust mite (HDM). Fifteen days post-infection, bronchoalveolar inflammation, serum antibodies, responsiveness to methacholine and barrier integrity were assessed. There was no effect of infection alone on bronchoalveolar lavage cellular inflammation 15 days post-infection; however, OVA or HDM challenge resulted in increased bronchoalveolar inflammation dominated by eosinophils/neutrophils or neutrophils, respectively. Previously infected mice had higher serum OVA-specific IgE compared with uninfected mice. Mice previously infected, sensitized and challenged with OVA were most responsive to methacholine with respect to airway resistance, while HDM challenge caused significant increases in both tissue damping and tissue elastance regardless of previous infection status. Previous influenza infection was associated with decreased claudin-1 expression in all groups and decreased occludin expression in OVA or HDM-challenged mice. This study demonstrates the importance of the respiratory epithelium in pre-sensitized individuals, where influenza-infection-induced barrier disruption resulted in increased systemic OVA sensitization and downstream effects on lung function.     

Raw Milk-Induced Protection against Food Allergic Symptoms in Mice Is Accompanied by Shifts in Microbial Community Structure

The mechanism underlying the allergy-protective effects of raw cow’s milk is still unknown, but the modulation of the gut microbiome may play a role. The effects of consuming raw cow’s milk or processed milk on fecal microbial communities were therefore characterized in an experimental murine model. C3H/HeOuJ mice were treated with raw milk, pasteurized milk, skimmed raw milk, pasteurized milk supplemented with alkaline phosphatase (ALP), or phosphate-buffered saline (PBS) for eight days prior to sensitization and challenge with ovalbumin (OVA). Fecal samples were collected after milk exposure and after OVA sensitization, and microbiomes were characterized using 16S ribosomal RNA gene amplicon sequencing. Treatment with raw milk prior to OVA sensitization increased the relative abundance of putative butyrate-producing bacteria from the taxa Lachnospiraceae UCG-001, Lachnospiraceae UCG-008, and Ruminiclostridium 5 (Clostridial clusters XIVa and IV), while it decreased the relative abundance of Proteobacterial genera such as Parasutterella, a putative pro-inflammatory bacterial genus. This effect was observed after eight days of raw milk exposure and became more pronounced five weeks later, after allergic sensitization in the absence of milk. Similar trends were observed after treatment with skimmed raw milk. Conversely, the feeding of pasteurized milk led to a loss of allergy protection and a putative dysbiotic microbiome. The addition of ALP to pasteurized milk restored the protective effect observed with raw milk and mitigated some of the microbial community alterations associated with milk pasteurization. Raw milk-induced protection against food allergic symptoms in mice is accompanied by an increased relative abundance of putative butyrate-producing Clostridiales and a decreased relative abundance of putative pro-inflammatory Proteobacteria. Given the safety concerns regarding raw milk consumption, this knowledge is key for the development of new, microbiologically safe, preventive strategies to reduce the incidence of allergic diseases.     

壳聚糖季铵盐修饰的辅酶Q10纳米结构脂质载体的制备及表征

为了增强运载辅酶Q10的纳米结构脂质载体(CoQ10-NLC)的透皮效果,采用促渗剂——壳聚糖季铵盐(QCS)对CoQ10-NLC进行了表面修饰,并结合QCS分子链的自聚集行为,明确了壳聚糖季铵盐修饰的包载辅酶Q10的纳米脂质体(QCS-CoQ10-NLC)的形成机制,得到了粒径在500 nm左右的脂质载体。进一步通过体外透皮实验,考察了QCS-CoQ10-NLC的透皮吸收效果。结果显示,经质量分数0.5%的QCS修饰后,脂质载体可将CoQ10在皮肤中的渗透总量由1.36μg/cm~2显著增加至5.14μg/cm~2。     

Chitosan-coated liposomes for enhanced skin permeation of resveratrol

In this study, chitosan-coated liposomes were investigated for use in enhanced transdermal delivery of resveratrol. Particle size, entrapment efficiency, stability, and skin-permeation efficiency were evaluated. The particle size was seen to increase on coating with chitosan, with higher concentrations of coating solution forming larger particles. The zeta potential of the liposomes also followed the same trend, i.e., it changed from a negative value for uncoated liposomes to increasingly positive values for the chitosan-coated ones. The chitosan coating was seen to increase the stability of the liposomes by preventing their aggregation. Transdermal delivery of uncoated and 0.1% chitosan-coated liposomes containing 0.1% resveratrol was investigated using Franz diffusion cells. The proportions of resveratrol that permeated the animal skin were 40.42% and 30.84% for the coated and uncoated liposomes, respectively. This increased skin-permeation efficiency with the coating could be explained by the tendency of positively charged liposomes to interact more strongly with the skin surface. These results indicate that chitosan-coated liposomes could be an effective transdermal delivery system for delaying skin aging using resveratrol.     

Elastic and Ultradeformable Liposomes for Transdermal Delivery of Active Pharmaceutical Ingredients (APIs)

Administration of active pharmaceutical ingredients (APIs) through the skin, by means of topical drug delivery systems, is an advanced therapeutic approach. As the skin is the largest organ of the human body, primarily acting as a natural protective barrier against permeation of xenobiotics, specific strategies to overcome this barrier are needed. Liposomes are nanometric-sized delivery systems composed of phospholipids, which are key components of cell membranes, making liposomes well tolerated and devoid of toxicity. As their lipid compositions are similar to those of the skin, liposomes are used as topical, dermal, and transdermal delivery systems. However, permeation of the first generation of liposomes through the skin posed some limitations; thus, a second generation of liposomes has emerged, overcoming permeability problems. Various mechanisms of permeation/penetration of elastic/ultra-deformable liposomes into the skin have been proposed; however, debate continues on their extent/mechanisms of permeation/penetration. In vivo bioavailability of an API administered in the form of ultra-deformable liposomes is similar to the bioavailability achieved when the same API is administered in the form of a solution by subcutaneous or epi-cutaneous injection, which demonstrates their applicability in transdermal drug delivery.     

Microemulsion of erythromycine for transdermal drug delivery

The aim of this work was to prepare an erythromycin (EM) microemulsion (EM‐ microemulsion) for transdermal EM delivery using isotropic mixtures of oil and aqueous phases. The prepared EM‐microemulsion is a white dispersion, with a suitable viscosity for transdermal delivery. In stability experiments, the EM‐microemulsion showed no marked change in appearance for up to 3 weeks at 25°C. In accelerated stability experiments at 37 and 60°C, however, precipitated crystalline EM particles were observed in the EM‐microemulsion. Diffusion of EM into the skin exhibited a first order release profile. Fluorescein (FL)‐microemulsion penetrated to the dermis layer of skin. In conclusion, we confirmed that EM‐microemulsion could serve as an excellent transdermal carrier of EM. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Optimization of square microneedle arrays for increasing drug permeability in skin

Microneedles array is a new transdermal drug delivery technique designed to create holes in the epidermis and penetrate the stratum corneum, thus avoiding the high resistance of this barrier. Microneedles have been shown to increase the skin permeability of drugs with no or little pain. However, the skin permeability of epidermis while using microneedle arrays has yet to be fully studied. In some cases, microneedle and microneedle array designs which were developed based on certain criteria (e.g., material of the microneedles) have to be related to other criteria (e.g., drug permeability in skin, skin thickness, etc.). Therefore, in order to determine the optimum design of the microneedle arrays, the effect of different factors (e.g., number of the microneedle, surface area of the patch, etc.) along with skin permeability by using microneedles should be determined accurately. In this work, an optimization framework for transdermal delivery of high molecular weight drug from microneedle is presented. The outputs of this framework have allowed us to identify the optimum design of various microneedles. Data from this optimization algorithm is then used to predict skin permeability of high molecular weight injected into the skin from a microneedle system. The effect of the optimized microneedles on blood drug concentration has been determined. The outcome of this study is useful to propose an optimum design based on different measurement (e.g., variation of skin thickness) for transdermal delivery of drugs.     

海蜇、牛骨和鳕鱼皮胶原肽的透皮吸收性能研究

以海蜇、牛骨和鳕鱼皮胶原为原料,采用酶解制备了不同分子量(1 kDa和1~3 kDa)的6种胶原肽。利用透皮扩散试验仪,考察了时间、分子量及质量浓度对胶原肽透皮吸收性的影响,通过荧光显微镜观察了异硫氰酸荧光素(FITC)标记的胶原肽对小鼠皮肤的透皮吸收过程。结果表明,6种胶原肽的质量浓度均为10 g/L时,其在24 h时透皮吸收能力由大到小依次为:1 kDa鳕鱼皮胶原肽、1 kDa牛骨胶原肽、1 kDa海蜇胶原肽、1~3 kDa海蜇胶原肽、1~3kDa牛骨胶原肽和1~3 kDa鳕鱼皮胶原肽;1 kDa胶原肽透皮吸收能力优于1~3 kDa胶原肽。牛骨和海蜇胶原肽的质量浓度越大,透皮吸收性越好,而鳕鱼皮胶原肽则相反。3种来源胶原肽单位面积累积透过量均随时间延长而增加,分子量越大透皮吸收性能越差。     

Hydrogels containing redispersible spray-dried melatonin-loaded nanocapsules: a formulation for transdermal-controlled delivery

The aim of the present study was to develop a transdermal system for controlled delivery of melatonin combining three strategies: nanoencapsulation of melatonin, drying of melatonin-loaded nanocapsules, and incorporation of nanocapsules in a hydrophilic gel. Nanocapsules were prepared by interfacial deposition of the polymer and were spray-dried using water-soluble excipients. In vitro drug release profiles were evaluated by the dialysis bag method, and skin permeation studies were carried out using Franz cells with porcine skin as the membrane. The use of 10% (w/v) water-soluble excipients (lactose or maltodextrin) as spray-drying adjuvants furnished redispersible powders (redispersibility index approximately 1.0) suitable for incorporation into hydrogels. All formulations showed a better controlled in vitro release of melatonin compared with the melatonin solution. The best controlled release results were achieved with hydrogels prepared with dried nanocapsules (hydrogels > redispersed dried nanocapsules > nanocapsule suspension > melatonin solution). The skin permeation studies demonstrated a significant modulation of the transdermal melatonin permeation for hydrogels prepared with redispersible nanocapsules. In this way, the additive effect of the different approaches used in this study (nanoencapsulation, spray-drying, and preparation of semisolid dosage forms) allows not only the control of melatonin release, but also transdermal permeation.     

Mechanism and determinants of nanoparticle penetration through human skin

The ability of nanoparticles to penetrate the stratum corneum was the focus of several studies. Yet, there are controversial issues available for particle penetration due to different experimental setups. Meanwhile, there is little known about the mechanism and determinants of their penetration. In this paper the penetration of four model gold nanoparticles of diameter 6 and 15 nm, differing in surface polarity and the nature of the vehicle, through human skin was studied using multiphoton microscopy. This is in an attempt to profoundly investigate the parameters governing particle penetration through human skin. Our results imply that nanoparticles at this size range permeate the stratum corneum in a similar manner to drug molecules, mainly through the intercellular pathways. However, due to their particulate nature, permeation is also dependent on the complex microstructure of the stratum corneum with its tortuous aqueous and lipidic channels, as shown from our experiments performed using skin of different grades of barrier integrity. The vehicle (toluene-versus-water) had a minimal effect on skin penetration of gold nanoparticles. Other considerations in setting up a penetration experiment for nanoparticles were also studied. The results obtained are important for designing a new transdermal carrier and for a basic understanding of skin-nanoparticle interaction.     

Skin Mast Cell-Driven Ceramides Drive Early Apoptosis in Pre-Symptomatic Eczema in Mice

Atopic dermatitis (AD or eczema) is the most common chronic inflammatory skin disorder worldwide. Ceramides (Cer) maintain skin barrier functions, which are disrupted in lesional skin of AD patients. However, Cer status during the pre-lesional phase of AD is not well defined. Using a variation of human AD-like preclinical model consisting of a 7-day topical exposure to ovalbumin (OVA), or control, we observed elevation of Cer C16 and C24. Skin mRNA quantification of enzymes involved in Cer metabolism [Cer synthases (CerS) and ceramidases (Asah1/Asah2)], which revealed augmented CerS 4, 5 and 6 and Asah1. Given the overall pro-apoptotic nature of Cer, local apoptosis was assessed, then quantified using novel morphometric measurements of cleaved caspase (Casp)-3-restricted immunofluorescence signal in skin samples. Apoptosis was induced in response to OVA. Because apoptosis may occur downstream of endoplasmic reticulum (ER) stress, we measured markers of ER stress-induced apoptosis and found elevated skin-associated CHOP protein upon OVA treatment. We previously substantiated the importance of mast cells (MC) in initiating early skin inflammation. OVA-induced Cer increase and local apoptosis were prevented in MC-deficient mice; however, they were restored following MC reconstitution. We propose that the MC/Cer axis is an essential pathogenic feature of pre-lesional AD, whose targeting may prevent disease development.     

三氮吲哚利嗪对氯化银乳剂光谱增感性能的影响

三氮吲哚利嗪（ＴＡＩ）是一种常用的银盐感光材料的稳定剂，许多研究表明ＴＡＩ在化学增感或光谱增感乳剂中具有超增感作用［１，２］，另有报道，它与光谱增感染料两者之间的添加次序对增感效果有很大的影响［１，６，７］．在Ｔａｎｉ的研究中［１］，在光谱增感后的乳...