Oxidative Stress and Atopic Dermatitis.

Atopic dermatitis is a common chronic/chronically relapsing inflammatory skin disease, with increasing worldwide prevalence. Etiopathogenesis is complex and multifactorial, with a mix of genetic, immunological and environmental aspects. Like in other chronic inflammatory diseases, oxidative stress plays an important pathogenetic role. We reviewed in vivo research studies on humans about oxidative stress and atopic dermatitis. Although sometimes contrasting, overall, they suggest that oxidative stress may have a significant role in atopic dermatitis, but our understanding is still incomplete, at least concerning in vivo data, because of limitations of available literature. Research consists of 33 papers published in 28 years, was not always performed on large study populations, represents a limited number of countries and ethnicities-not always in proportion to their size-and is scattered over multiple papers that, in the majority of cases, cannot be pooled and/or compared because many biomarkers were studied, in different tissues and with different methods. Further, larger studies appear warranted and necessary to shed more light on this aspect of atopic dermatitis, which is important not only to improve our understanding of this disease, but also for potential clinical and therapeutic implications.

Hydrogen Peroxide Insular Dodecameric and Pentameric Clusters in Peroxosolvate Structures.

Peroxosolvates of 2-aminonicotinic acid (I) and lidocaine N-oxide (II) including the largest insular hydrogen peroxide clusters were isolated and their crystal structures were determined by single-crystal X-ray diffraction. An unprecedented dodecameric hydrogen peroxide insular cluster was found in I. An unusual cross-like pentameric cluster was observed in the structure of II. The topology of the (H2 O2 )12 assembly was never observed for small-molecule clusters. In I and II new double and triple cross-orientational disorders of H2 O2 were found. Cluster II is the first example of a peroxosolvate crystal structure containing H2 O2 molecules with a homoleptic hydrogen peroxide environment. In II, a hydrogen bond between an H2 O2 molecule and a peptide group -CONH⋅⋅⋅O2 H2 was observed for the first time.

The human Nox4: gene, structure, physiological function and pathological significance.

Increased generation of reactive oxygen species (ROS) has been implicated in the pathogenesis of a variety of diseases such as cardiovascular diseases and cancer. NADPH oxidase (Nox), a multicomponent enzyme, has been identified as one of the key sources of ROS. Nox4, one of the seven members of Nox family (Nox1, Nox2, Nox3, Nox4, Nox5, Duox1 and Duox2), has been extensively investigated in recent years. Its unique structures result in the constitutive generation of hydrogen peroxide (H2O2) as the main product. As a key oxygen sensor, Nox4-derived H2O2 plays diverse roles in cell proliferation, migration and death. Increased expression of Nox4 in cancer has been observed, which participates in metastasis, angiogenesis and apoptosis. Expression of Nox4 in endothelial cells actively mediated endothelial activation, dysfunction and injury, which contributes to the development of atherosclerosis, hypertension, cardiac hypertrophy and among others. This article explores the experimental studies related to the gene, structure, physiological function and pathological significance of Nox4. As Nox4 might serve as a potential target for the therapy of cardiovascular diseases and cancer, the Nox4 inhibitor is also discussed in this article.

Protection of δ-opioid receptor stimulation against injured myocardial cells by hydrogen peroxide / 中国药理学与毒理学杂志

AIM To study protective effect of [D-Ala~2, D-Leu~5]-enkephalin (DADLE) against hydrogen peroxide (H_2O_2) induced myocardial cell injury and its possible mechanisms. METHODS Myocardial cells were isolated from neonatal rats and cultured for 48 h. Then the cells were randomly assigned into normal control, H_2O_2（200 μmol·L~(-1)）, H_2O_2+DADLE(1 μmol·L~(-1)), H_2O_2+DADLE +naltrindole(10 μmol·L~(-1)) and H_2O_2+DADLE +U0126(10 nmol·L~(-1)) groups and cultured for another 48 h.[~3H]TdR incorporation assay and flow cytometry were used to measure the cell proliferation and apoptosis rate. The lactate dehydrogenase (LDH) activities in culture supernatant measured by using LDH activity kit. The superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in cells were measured with xanthine oxidase method and color reaction of thiobarbituric acid, respectively. The expressions of extracellular signal-regulated kinase (ERK) and phosphorylated-ERK (p-ERK) were observed with Western blot. RESULTS ① Compared with normal control group, the incorporation of [~3H]TdR in myocardial cells of H_2O_2 group was significantly lower, apoptosis rate was higher, LDH activity and MDA content in cells were higher, while SOD activity in cells was lower. In addition, the ratio of IA_( p-ERK) /IA_( ERK) was decreased. ② Compared with H_2O_2 group, the incorporation of ［3H］TdR in H_2O_2+DADLE group was significantly higher, apoptosis rate was lower, LDH activity and MDA content in cells decreased, while SOD activity increased significantly. The ratio of IA_( p-ERK) /IA_( ERK) was increased. ③ δ-Opioid receptor antagonist naltrindole and ERK antagonist U0126 inhibited this effect of DADLE on the above index changes induced by H_2O_2. CONCLUSION The δ-opioid receptor has protective effect against H_2O_2-induced myocardial cell injury, and its possible mechanism may be related to its promotion of antioxide capacity and ERK phosphorylation.

PRELIMINARY STUDIES ON LIVE YEAST CELL DERIVATIVE / 微生物学通报

Live Yeast Cell Derivative (LYCD) was based on a living cells response to a controlled injury, which stimulated it to produce protective substance to increase cellular respiration and wound healing The experiment suggested that LYCD had the ability to improve cellular respiration, and this ability became strongest after the cell was treated with H 2O 2 for 15min, while the quantity of reduced glutathione (GSH) in LYCD reached the highest at 30min By contrast, almost the same biological activity of LYCD was observed under different stress conditions