The in vitro role of tumour necrosis factor-alpha and interleukin-6 in the hypothalamic-pituitary gonadal axis

The adipocyte derived hormone leptin has been implicated as an important nutritional signal to the reproductive system, but the role of other adipocyte related cytokines is not clear. Tumour necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6 are present in adipose tissue and released into the circulation where plasma levels correlate positively with body mass index and body fat mass. These cytokines could play a role in signalling nutritional status to the hypothalamic-pituitary-gonadal axis. We investigated the effects of TNF-alpha and IL-6 on basal and luteinizing hormone releasing hormone (LHRH) stimulated luteineizing hormone (LH) release from cultured anterior pituitary cells, harvested from either proestrus female or male Wistar rats. We examined the effects of TNF-alpha and IL-6 on LHRH release from hypothalamic explants harvested from proestrus female and male rats in vitro. IL-6 significantly suppressed LHRH stimulated LH release from male dispersed pituitaries throughout the dose range, but did not influence basal LH release. IL-6 had no effect on basal or LHRH stimulated LH release in dispersed pituitaries from proestrus females. By contrast, TNF-alpha significantly suppressed LHRH stimulated LH release in dispersed pituitaries from proestrus female rats in a dose responsive manner, but did not influence basal LH release. TNF-alpha had no effect on basal or LHRH stimulated LH release in dispersed pituitaries from male rats. TNF-alpha and IL-6 had no effect on LHRH release from male hypothalamic explants in vitro. TNF-alpha and IL-6 had no effect on LHRH release from proestrus female hypothalamic explants in vitro. TNF-alpha and IL-6 have differential effects in dispersed pituitaries harvested from males and proestrus female rats. TNF-alpha and IL-6 may be important in mediating some of the nutritional effects on the reproductive axis by acting at the level of the anterior pituitary rather than the hypothalamus.     

Ameliorating Effect of Akebia quinata Fruit Extracts on Skin Aging Induced by Advanced Glycation End Products

The accumulation of free radicals and advanced glycation end products (AGEs) in the skin plays a very important role in skin aging. Both are known to interact with each other. Therefore, natural compounds or extracts that possess both antioxidant and antiglycation activities might have great antiageing potential. Akebia quinata fruit extract (AQFE) has been used to treat urinary tract inflammatory disease in traditional Korean and Chinese medicines. In the present study, AQFE was demonstrated to possess antioxidant and antiglycation activity. AQFE protects human dermal fibroblasts (HDFs) from oxidative stress and inhibits cellular senescence induced by oxidative stress. We also found that AQFE inhibits glycation reaction between BSA and glucose. The antiglycation activity of AQFE was dose-dependent. In addition, the antiglycation activity of AQFE was confirmed in a human skin explant model. AQFE reduced CML expression and stimulated fibrillin-1 expression in comparison to the methyglyoxal treatment. In addition, the possibility of the extract as an anti-skin aging agent has also been clinically validated. Our analysis of the crow’s feet wrinkle showed that there was a decrease in the depth of deep furrows in RI treated with AQFE cream over an eight-week period. The overall results suggest that AQFE may work as an anti-skin aging agent by preventing oxidative stress and other complications associated with AGEs formation.     

Direct sampling of cystic fibrosis lungs indicates that DNA-based analyses of upper-airway specimens can misrepresent lung microbiota

Recent work using culture-independent methods suggests that the lungs of cystic fibrosis (CF) patients harbor a vast array of bacteria not conventionally implicated in CF lung disease. However, sampling lung secretions in living subjects requires that expectorated specimens or collection devices pass through the oropharynx. Thus, contamination could confound results. Here, we compared culture-independent analyses of throat and sputum specimens to samples directly obtained from the lungs at the time of transplantation. We found that CF lungs with advanced disease contained relatively homogenous populations of typical CF pathogens. In contrast, upper-airway specimens from the same subjects contained higher levels of microbial diversity and organisms not typically considered CF pathogens. Furthermore, sputum exhibited day-to-day variation in the abundance of nontypical organisms, even in the absence of clinical changes. These findings suggest that oropharyngeal contamination could limit the accuracy of DNA-based measurements on upper-airway specimens. This work highlights the importance of sampling procedures for microbiome studies and suggests that methods that account for contamination are needed when DNA-based methods are used on clinical specimens.     

Ganglioside GM1 overcomes serum inhibition of neuritic outgrowth

Considerable variations in both neuritic and non-neuronal cell outgrowths of ganglionic expiant cultures are imposed when different substrata and medium supplements are used. Therefore, a neuritic response to exogenous agents such as gangliosides may be better, or exclusively revealed under selected combinations of medium and substratum. We have surveyed a number of different ganglia for their ability to display a neuritic response to ganglioside GM1 and the culture conditions under which such a display may take place. GM1 can recognizably promote neurite extension from embryonic day 8 chick dorsal root ganglia, day 11 sympathetic ganglia, and day 8 ciliary ganglia. Demonstration of such effects, however, requires an appropriate balance between promoting and inhibiting influences by other extrinsic influences (culture substrata, neuronotrophic factors, serum inhibitors) thereby allowing for improvement by the ganglioside. Different ganglia require different combinations of those influences. Ciliary ganglia, for example, will show a GM1 response on a polyornithine substratum in medium supplemented with the chick eye Ciliary Neuronotrophic Factor and 1% fetal calf serum, but not with 10% serum or no serum. The effective concentration range for GM1 is in accord with previously reported serum binding data. These, and other data are consistent with an action of GM1 in executing a neurite program, rather than an imposition of the program itself.     

Glutamic acid induces luteinizing hormone releasing hormone release via alpha receptors

Glutamic acid (GA) and norepinephrine (NE) stimulate luteinizing hormone-releasing hormone (LHRH) release via release of nitric oxide (NO) from NOergic neurons in the arcuatemedian eminence region. To determine if GA releases LHRH via direct stimulation of NOergic neurons, or via stimulation of noradrenergic terminals, arcuate median eminence explants from male rats were incubated with various compounds, and the LHRH release into the medium was measured. GA-induced release of LHRH was completely blocked by phentolamine (1 μM), an alpha receptor blocker, which, by itself, had no effect on the release. Nitroprusside (NP), which spontaneously releases NO, more than doubled LHRH release. To determine if alpha receptors on the LHRH neuron are required for the action of NP, the tissue was incubated with phentolamine, plus NP. Phentolamine had no effect on the LHRH-releasing action of NP. The results are interpreted to mean that GA activates the release of NE from the noradrenergic terminals. This acts on alpha receptors on the NOergic neuron to produce the release of NO. This NO diffuses to the LHRH terminals and induces release of LHRH.     

Patterns of secretion of human chorionic gonadotrophin by superfused placental explants and the embryo--placental relationship following maternal use of medications.

There is great concern regarding maternal exposure to medications, especially in the first trimester of pregnancy because of the possible teratogenic effects. In the present study we have examined the consequences of maternal drug exposure in vivo upon placental secretion patterns of human chorionic gonadotrophin (HCG) and the relationship between the embryo and placenta in vitro. This was examined in samples obtained from various drug-exposed women following elective pregnancy termination at 8-9 weeks. The patterns of HCG secretion in superfused placental explants were different from those seen in control explants (without use of any medication). This was shown by changes in the pulse pattern and pulse frequency. In addition, the exposure of placental explants to various embryonic tissues modified HCG secretion in static cultures. In superfusion, co-perfusion with embryonic spinal cord tissue increased HCG secretion as opposed to that seen in similar incubations made with embryonic spinal cord tissue obtained from healthy women. Thus, our data suggest that maternal drug exposure alters both spontaneous hormone secretion by the placenta and the recently described embryo--placental relationship in vitro.     

An improved method of establishing human fibroblast cultures from explants

Summary A method of using cover slips in establishing human fibroblast cultures from explants is described. This procedure has three important advantages. Firstly, the cover slips with cells may be removed from the explants and transferred without the use of trypsin. Secondly, cells grow out from the explants within 48 hours and ready to be transferred within two weeks. Thirdly, it eliminates the problems of detachment of the explants from culture dishes.     

Serum- and substratum-dependent modulation of neuritic growth

Explants of embryonic day 8 (E8) chicken dorsal root ganglia (DRG) have been cultured with medium containing serum or the serum-free supplement N1 on one of three substrata: collagen, polyornithine (PORN), or PORN exposed to a polyornithine-binding neurite-promoting factor (PNPF-PORN). Replicate cultures were maintained with or without nerve growth factor (NGF). NGF elicited its classical neuritic outgrowth on all three substrata in serum-containing or serum-free medium. In the absence of NGF, however, a gradation of increasing neurite growth was seen with: PNPF-PORN greater than PORN greater than collagen. This response occurred in both media. In addition, the neuritic halo in each instance was markedly more developed in the absence of serum, especially on PNPF-PORN. Nonneuronal behaviors reflected both serum and substratum influences: thus, nonneuronal outgrowth consisted mainly of flat cells with serum and collagen, was nonexistent with serum and PORN or PNPF-PORN, and involved mostly Schwann-like scattered cells in the absence of serum on any one substratum. The serum-dependent behaviors of ganglionic neurites were examined further with explants from chicken E11 sympathetic ganglia. A single substratum was used (PORN), without exogenous trophic factor. Neurite outgrowth was depressed by the presence of fetal calf serum, thus supporting the generality of this phenomenon. Lastly, PC12 cells, a clonal line of rat pheochromocytoma, will grow neurites in the presence of NGF after 48 hr in serum-free, but not serum-containing media. Addition of serum to serum-free cultures at this time results in the rapid and complete retraction of neurites.     

基于计算机辅助药物设计方法探究敦煌消痹止痛酊治疗骨关节炎的物质基础

目的 采用皮肤渗透性参数计算、复杂网络分析、分子对接、分子动力学模拟等计算机辅助药物设计结合化学分析、体外生物试验的“干湿”结合策略探究敦煌消痹止痛酊治疗骨关节炎(osteoarthritis,OA)的物质基础。方法 选择被实验证实的中药来源的可透皮化合物,利用Schrödinger软件Qikprop模块进行皮肤渗透性参数计算,建立透皮参数范围标准,并筛选敦煌消痹止痛酊中满足条件的化合物。对敦煌消痹止痛酊进行功效分组,通过靶点反向预测-复杂网络分析-KEGG通路富集分析探讨不同功效组治疗OA的潜在靶点及KEGG通路。采用分子对接的方法对方中符合皮肤渗透性参数范围的成分进行虚拟筛选,挑选化合物进行酶活性测定、ADMET计算、皮肤渗透性测定、细胞试验、外植体试验研究。结果 全方得到潜在透皮成分为69个,复杂网络分析结果显示活血组治疗OA的特有靶点主要为VEGFA、IGF1R及HIF-1α等,主要KEGG通路为Ras、RAP1等。清热组治疗OA的特有靶点主要为TLR9、IL-6及ADAMTS5等,主要KEGG通路涉及TNF、NF-κB等信号通路;分子对接-酶活性-细胞试验结果显示,升麻素、欧前胡素和香草酸对COX-2具有抑制活性,可以抑制软骨细胞PGE2的合成。在软骨外植体模型中,升麻素可以有效缓解软骨损伤;体外透皮试验显示,升麻素12 h内皮肤累积渗透量达到128.1 μg·cm^-2,透皮吸收百分率为28.2%。分子动力学模拟结果显示,升麻素与COX-2的氨基酸残基TYR 355、LEU 384、SER 530形成较为稳定的氢键作用,与PHE 518形成较为稳定的疏水相互作用。结论 本研究采用计算机辅助药物设计联合多种化学生物实验技术的“干湿”结合策略初步阐明了敦煌消痹止痛酊治疗OA的物质基础,为外用中药的研究提供参考。