Selenium levels in human plasma and hair in northern poland

The aim of this study was to (1) estimate the concentration of selenium in the plasma of 146 residents (65 men and 81 women) and in the hair of 34 persons from the Gdańsk region in northern Poland, aged 19–70 and (2) compare the obtained results with data corresponding to healthy populations living in different European countries. Selenium in plasma was determined by atomic absorption spectrometry using the hydride generation method. The mean selenium concentration in plasma of the investigated persons was 73.3 ± 14.1 μg/L, 76.7 ± 13.2 μg/L in men, and 70.4 ± 14.7 μg/L in women. No age — dependent differences in plasma selenium were found in the investigated population. In 20% of the investigated persons, the selenium level in plasma was lower than 60 μg/L. The mean selenium concentration in hair was 0.30 ± 0.11 μg/g. A positive, statistically significant correlation between selenium concentrations in the plasma and hair of the investigated persons was found. The obtained results indicate that the selenium level in significant part of this population is suboptimal and should be elevated by supplementation with this element.     

Molecular species of epidermal growth factor carrying immunosuppressive activity

The suppression of antibody formation to sheep red cells in mice by partially purified fractions of mouse submaxillary gland was shown to be caused by epidermal growth factor (EGF). Purification of EGF by the method of Savage and Cohen resolved three components referred to as EGF a, EGF b, and EGF c. All three induced premature eye opening in neonatal mice, but only EGF a (identified as EGF 1-53) had full immunosuppressive activity. EGF c was shown by micropeptide mapping of chymotryptic and thermolytic digests and amino-terminal analysis to differ from EGF a only by the presence of beta-aspartyl instead of an asparaginyl residue. EGF b differed from EGF a in that it lacked the N-terminal asparagine. EGF shortened enzymatically at its carboxy terminal by two or five amino acids did not have any immunosuppressive activity. These findings suggest that, in contrast to some other biological effects of EGF, intact amino and carboxy terminals are required for the expression of immunosuppressive activity.     

小柴胡汤加减联合奥美拉唑对慢性胃炎具有治疗增效作用

本研究选取本院收治的慢性胃炎患者114例并根据治疗方法不同分为对照组和观察组。对照组患者采用奥美拉唑治疗,观察组患者采用奥美拉唑联合小柴胡汤加减治疗,分析小柴胡汤加减联合奥美拉唑对慢性胃炎血清表皮生长因子(EGF)、胃黏膜氧化酶-2 (COX-2)蛋白表达情况的影响及护理对策。研究结果表明,治疗前两组患者胃镜检查充血水肿、糜烂、黏膜白相、颗粒增生发生率比较无统计学差异(p>0.05);治疗后,观察组患者各项指标发生率低于对照组(p<0.05);治疗前,两组患者血清EGF、Bcl-2、CRP和胃黏膜COX-2、P-p65表达水平比较无统计学差异(p>0.05),治疗后发现观察组患者血清EGF水平高于对照组,血清Bcl-2、CRP和胃黏膜COX-2、P-p65表达水平低于对照组(p<0.05);治疗前,两组患者在躯体功能、躯体职能、躯体疼痛、情感职能、心理健康评分等生活质量评分上比较无统计学差异(p<0.05),治疗后,观察组患者各项评分高于对照组(p>0.05)。本研究初步结论说明,小柴胡汤加减联合奥美拉唑治疗慢性胃炎疗效显著,可改善患者血清EGF、Bcl-2和胃黏膜COX-2表达水平,提高患者生活质量。     

ARAP1 association with CIN85 affects epidermal growth factor receptor endocytic trafficking

Background information. ARAP1 is an Arf (ADP‐ribosylation factor)‐directed GAP (GTPase‐activating protein) that inhibits the trafficking of EGFR (epidermal growth factor receptor) to the early endosome. To further understand the function of ARAP1, we sought to identify proteins that interact with ARAP1. Results. Here we report that ARAP1 associates with the CIN85 (Cbl‐interacting protein of 85 kDa). Arg⁸⁶ and Arg⁹⁰ of ARAP1 and the SH3 (Src homology 3) domains of CIN85 are necessary for the interaction. We found that a mutant of ARAP1 with reduced affinity for CIN85 does not efficiently rescue the effect of reduced ARAP1 expression on EGFR trafficking to the early endosome. Reduced expression of CIN85 has a similar effect as reduced expression of ARAP1 on traffic of the EGFR. Cbl proteins regulate the endocytic trafficking of the EGFR by mediating ubiquitination of the EGFR. Overexpression of ARAP1 reduced ubiquitination of the EGFR by Cbl and slowed Cbl‐dependent degradation of the EGFR. Reduced expression of ARAP1 accelerated degradation of EGFR but did not affect the level of ubiquitination of the receptor that was detected. Conclusion. ARAP1 interaction with CIN85 regulates endocytic trafficking of the EGFR and affects ubiquitination of EGFR. We propose a model in which the ARAP1‐CIN85 complex drives exit of EGF—EGFR–Cbl complex from a pre‐early endosome into a pathway distinct from the early endosome/lysosome pathway.     

Structure,function, aging and turnover of aggrecan in the intervertebral disc

Background

Aggrecan is the major non-collagenous component of the intervertebral disc. It is a large proteoglycan possessing numerous glycosaminoglycan chains and the ability to form aggregates in association with hyaluronan. Its abundance and unique molecular features provide the disc with its osmotic properties and ability to withstand compressive loads. Degradation and loss of aggrecan result in impairment of disc function and the onset of degeneration.

Scope of review

This review summarizes current knowledge concerning the structure and function of aggrecan in the normal intervertebral disc and how and why these change in aging and degenerative disc disease. It also outlines how supplementation with aggrecan or a biomimetic may be of therapeutic value in treating the degenerate disc.

Major conclusions

Aggrecan abundance reaches a plateau in the early twenties, declining thereafter due to proteolysis, mainly by matrix metalloproteinases and aggrecanases, though degradation of hyaluronan and non-enzymic glycation may also participate. Aggrecan loss is an early event in disc degeneration, although it is a lengthy process as degradation products may accumulate in the disc for decades. The low turnover rate of the remaining aggrecan is an additional contributing factor, preventing protein renewal. It may be possible to retard the degenerative process by restoring the aggrecan content of the disc, or by supplementing with a bioimimetic possessing similar osmotic properties.

General significance

This review provides a basis for scientists and clinicians to understand and appreciate the central role of aggrecan in the function, degeneration and repair of the intervertebral disc.     

Purification of Porcine Hair Keratin Subunits and Their Immobilization for Use as Cell Culture Substrates

We purified both the type I subunit and type II subunit of porcine hair keratin and compared their ability to form a uniform film of reconstituted keratin on a culture plate, and their effect on a model of neural cells. We observed the surface of the keratin-immobilized plate using a scanning electron microscope (SEM) and measured water contact angles to characterize the surface. We cultured PC12 cells on plates on which crude keratin, the type I subunit, or the type II subunit were immobilized. The water contact angles were slightly different from each other. The cells proliferated well on all three keratin-immobilized plates. The type II subunit showed a tendency to inhibit the differentiation of PC12 cells significantly as an extension of the cell shapes and neurite outgrowth in comparison with the crude extract and the type I subunit. The type I subunit and the type II subunit showed slight differences in cell differentiation, but not in cell proliferation.     

DNA topoisomerase activities in concanavalin A-stimulated lymphocytes

Topoisomerase activities have been measured in nuclear extracts of concanavalin A-stimulated lymphocytes. In parallel with the wave of DNA synthesis, type II topoisomerase activity was considerably increased. After 72 h treatment, this activity was stimulated approx. 20-fold over the activity in untreated cells. In contrast, type I topoisomerase was poorly stimulated after 24 h treatment, and 4-5-fold after 72 h. These findings, together with our previous results on regenerating rat liver, suggest a major role of topoisomerase II in DNA replication.     

Characterization of a thy1.2 GFP transgenic mouse reveals a tissue-specific organization of the spinal dorsal horn

In this study, transgenic mice in which membrane-linked enhanced green fluorescent protein (mGFP) is expressed from the Thy1.2 promoter were used. In these mice, a subpopulation of small to medium sized DRG neurons double stained for IB4 but not for CGRP. Most of the peripheral terminals traversed the dermis and ramify within the epidermis and form superficial terminals. Within the spinal cord, these afferents terminated exclusively within the substantia gelatinosa (SG). A second fibre type in the skin also expressed mGFP, and formed club-shaped endings towards the bases of hairs. Injury to the sciatic nerve resulted in mGFP loss from the SG ipsilateral to the nerve injury, but also in the corresponding region contralaterally. Together, these findings reveal the specificity of connectivity of a defined subpopulation of DRG sensory neurons innervating the epidermis and this will facilitate analysis of their physiological functions.     

Novel matrine derivative MD-1 attenuates hepatic fibrosis by inhibiting EGFR activation of hepatic stellate cells

Matrine (MT), the effective component of Sophora flavescens Ait, has been shown to have anti-inflammation, immune-suppressive, anti-tumor, and anti-hepatic fibrosis activities. However, the pharmacological effects of MT still need to be strengthened due to its relatively low efficacy and short half-life. In the present study, we report a more effective thio derivative of MT, MD-1, and its inhibitory effects on the activation of hepatic stellate cells (HSCs) in both cell culture and animal models. Cytological experiments showed that MD-1 can inhibit the proliferation of HSC-T6 cells with a half-maximal inhibitory concentration (IC50) of 62 μmol/L. In addition, MD-1 more strongly inhibits the migration of HSC-T6 cells compared to MT and can more effectively induce G0/G1 arrest and apoptosis. Investigating the biological mechanisms underlying anti-hepatic fibrosis in the presence of MD-1, we found that MD-1 can bind the epidermal growth factor receptor (EGFR) on the surface of HSC-T6 cells, which can further inhibit the phosphorylation of EGFR and its downstream protein kinase B (Akt), resulting in decreased expression of cyclin D1 and eventual inhibition of the activation of HSC-T6 cells. Furthermore, in rats with dimethylnitrosamine (DMN)-induced hepatic fibrosis, MD-1 slowed the development and progression of hepatic fibrosis, protecting hepatic parenchymal cells and improving hepatic functions. Therefore, MD-1 is a potential drug for anti-hepatic fibrosis.