Circadian rhythm of melatonin release in pineal gland culture: arg-vasopressin inhibits melatonin release

The mammalian pineal gland is known to receive a noradrenergic sympathetic efferent signal from the suprachiasmatic nucleus (SCN) via the superior cervical ganglion. Arg-vasopressin (AVP) containing neurons in the SCN is one of the output paths of circadian information to the other brain areas. AVP release from the SCN is suppressed by melatonin. In turn, we determined the direct effect of AVP on melatonin release using pineal gland explant culture. AVP (1 μM) suppressed melatonin release. Noradrenaline stimulated melatonin release was attenuated by AVP. In turn, the expression of the melatonin synthesis enzyme arylalkylamine N-acetyltransferase mRNA in the rat SCN was reported. We measured melatonin content in the SCN in rats kept under the light–dark cycle and constant dim light. Melatonin in the SCN was higher during the dark period than that in the light. A similar tendency was also observed in the SCN of animals kept under a constant dim light. It was suggested that the reciprocal regulation of melatonin release and AVP release occurs in the SCN and pineal gland.     

组织贴块法人的支气管上皮细胞的原代培养

目的 通过组织贴块法建立人的支气管上皮细胞原代培养的方法.方法 采用无血清支气管上皮培养基,对经手术切除获得的支气管进行组织贴块法培养获得的细胞进行原代培养和传代,通过倒置显微镜以及细胞免疫化学观察和鉴定细胞.结果 此方法获得的细胞成活率高、纯度高,细胞呈扁平、多边形,象铺路的鹅卵石样分布.细胞角蛋白表达阳性.结论 组织贴块法是一种简便、有效的培养人的支气管上皮细胞的方法,无血清培养基可提供满意的生长条件,提高上皮细胞的纯度,为进一步研究不同的呼吸系统疾病提供了良好的模型.     

从脊柱内镜手术摘除组织中分离髓核间充质干细胞及其生物学特征鉴定

目的:利用经皮内镜下腰椎间盘切除术获取来源明确的髓核组织,结合组织块培养法高效分离培养人髓核间充质干细胞(human nucleus pulposus mesenchymal stem cells,hNP-MSCs),并鉴定其生物学特征。方法:收集6例腰间盘突出症手术摘除的髓核组织,利用组织块培养法分离培养。取第3~6代生长良好的细胞用于实验,采用CCK-8检测增殖能力;用流式细胞术检测细胞表面标志物;并分别向成骨、成脂和成软骨方向诱导分化,用油红O染色、茜素红染色及阿利新蓝染色对分化结果进行检测。结果:成功从椎间盘内镜摘除的髓核组织中分离培养具有增殖能力的细胞,流式细胞术检测显示细胞高表达CD29、CD44、CD90、CD73和CD105等间充质干细胞抗原,不表达造血干细胞标志CD34和CD45。生长曲线显示符合正常间充质干细胞增殖特征。茜素红染色、阿利新蓝染色及油红O染色均呈阳性,说明分离培养的细胞具有向成骨、成软骨和成脂肪诱导分化的能力。结论:首次结合椎间盘内镜微创手术和组织块培养法,体外高效分离培养了具有自我更新能力和多向分化潜能的hNP-MSCs。     

Mesenchymal stem cell-like cells from children foreskin inhibit the growth of SGC-7901 gastric cancer cells

Mesenchymal stem cells (MSCs) become a research hotspot in recent years because of their roles in regenerative medicine and tissue injury repair. However, the limited source for MSCs hampers its clinical application. In this study, we isolated and identified human mesenchymal stem cell-like cells from foreskin (hFMSCs) by explant culture. HFMSCs had similar morphology and immunophenotype to that of human bone marrow derived-mesenchymal stem cells. HFMSCs formed colonies after 9 days of inoculation and could be propagated for more than 50 passages. HFMSCs had a normal karyotype and high G0/G1 phase independent of passage number. Further, hFMSCs could be induced to differentiate into osteocytes and adipocytes. We found that the growth of SGC-7901 (human gastric adenocarcinoma) cells could be suppressed by simultaneous injection of hFMSCs in vivo. HFMSCs also inhibited SGC-7901 cell proliferation in vitro. HFMSC co-injection resulted in a decrease in PCNA-positive and an increase in apoptotic tumor cells. HFMSCs derived conditioned medium inhibited the expression of BCL-2 while increased the expression of BAX and caspase-3 in SGC-7901 cells. Taken together, our findings suggest that children foreskin is a new source for MSCs and hFMSCs could inhibit gastric cancer cell growth both in vitro and in vivo.     

Histochemical and electrophysiological evidence for estrogen receptors on cultured astrocytes: colocalization with cholinergic receptors

By means of autoradiographic and immunohistochemical methods it was demonstrated that astrocytes in explant and primary cultures of rat neocortex, hippocampus, preoptic area and spinal cord express estrogen alpha- and beta-receptors. Immunoreactivity was mainly distributed over the soma, the nuclei being more intensely stained. Combined autoradiographic and immunohistochemical studies as well as double-immunostaining revealed a colocalization of estrogen alpha- and beta-receptors on many astrocytes. There was also a coexistence of estrogen receptors and cholinergic muscarinic and nicotinic sites. Electrophysiological investigations have shown that 17beta-estradiol induced hyperpolarizations on the majority of astrocytes in explant cultures of hippocampus and spinal cord, providing evidence for the existence of functional estrogen receptors on these cells. Furthermore, on the same astrocytes, 17beta-estradiol, muscarine and nicotine caused hyperpolarizations, suggesting a coexistence of receptors for estrogen and the cholinergic agonists on glial cells. The presence of glial estrogen receptors and their colocalization with cholinergic receptors is discussed with respect to the effects of these neurotransmitters/neuromodulators in development and maturation of the central nervous system, as well as to neurodegenerative events such as Alzheimer's disease.     

Explant culture: an efficient method to isolate adipose-derived stromal cells for tissue engineering

Enzymatic digestion, the commonly used method of adipose-derived stromal cells isolation, is time consuming and expensive, especially when applied to large volumes of tissue. In the present study, the characteristics of the cells obtained by adipose tissue explant culture were studied. We found that adipose tissue fragments could adhere onto the growth surface of flasks in a very short time after plating and that fibroblast-like cells migrated from the explants and reached confluence. Morphologic analysis and surface markers expression suggested the mesenchymal origin of the cells derived from adipose tissue explants. After in vitro expansion these cells were successfully induced into adipogenic, osteogenic, and chondrogenic lineages, which demonstrated their multipotency. The high growth rate and colony-forming efficiency of explant-derived cells were similar to those of cells obtained by digestion. Furthermore, explant culture gave higher yield of cells than digestion method after primary culture. The experiment of ectopic adipogenesis in nude mice suggested the prospects for tissue engineering of these cells. In conclusion, we obtained multipotent stromal cells from adipose tissue by explant culture, and this method was simple, time saving, and gave a high yield of cells. Therefore, explant culture can be used as an effective way to isolate adipose-derived stromal cells for tissue engineering.     

Cell proliferation in explant cultures of malignant gliomas

Summary Primary explant cultures were grown from human malignant gliomas. Ten-day cultures contained pleomorphic tumour cells with overlapping processes and contaminating elements, consisting chiefly of fibroblasts which grew in sheets of contact-inhibited cells. Cultures pulse-labelled with thymidine-H³ for one hour showed labelling in many fibroblast nuclei. Virtually no labelling was seen in the cells of apparent tumour origin. Most labelled cells were concentrated near the explant. Results are discussed in relation to the mode of outgrowth of the different cell types.     

抗癌中药制剂局部注射对裸鼠人肝癌细胞核DNA含量的影响

应用自动化图像分析技术对裸鼠人肝癌经局部注射抗癌中药制剂治疗的肝癌细胞核DNA含量进行定量测定,结果表明:经局部治疗后的DNA相时含量均下降(由22.57降到16.13,15.86),与对照组间盖异有显著意义(P<0.01),病理组织学改变为癌组织坏死,纤维组织增生及炎细胞浸润。因此作者认为,洲定DNA含量和组织病理学观察,对抗癌药物疗效的评价,具有重要意义。     

Colocalization of androgen, estrogen and cholinergic receptors on cultured astrocytes of rat central nervous system

By means of immunohistochemical and electrophysiological methods, we have investigated the presence of androgen receptors on astrocytes in explant and primary cultures from various regions of rat central nervous system. Our studies have shown that a great number of astrocytes and neurones express androgen receptors as recognized by a specific monoclonal antibody. Immunoreactivity was mainly distributed over the soma of the astrocytes, the nuclei being intensely stained. In contrast, glial processes were only faintly stained or not stained. Double-immunostaining studies have provided evidence for a colocalization of androgen and estrogen alpha- and beta-receptors on many astrocytes. Furthermore, there was also a coexistence of glial androgen receptors with cholinergic muscarinic and nicotinic sites. Our immunohistochemical findings are supported by electrophysiological investigations demonstrating that 5alpha-androstan, 17beta-estradiol as well as the cholinergic agonists muscarine and nicotine caused hyperpolarizations on the same astrocytes. Our studies suggest that there is a coexistence of functional receptors for androgen, estrogen as well as for the cholinergic agonists on glial cells. Further investigations are needed to elucidate the physiological role of glial androgen, estrogen and cholinergic receptors and to define their function in neurodegenerative diseases.     

Influence of rheumatoid synovial fluid and cells on proteoglycans in human cartilage explants. Modulation by piroxicam

Summary We have studied the effects of cell-free rheumatoid synovial fluid (RASF) and the conditioned medium (CM) from these cells on the proteoglycans (PGs) of normal human cartilage and the influence which piroxicam might have on these processes. Both RASF and the CM from RASF cells enhanced the PG release from the cartilage explants. The effects of the above mentioned fluids on the cartilage PG content depended on the metabolic state of the cartilage i.e. correlated inversely with the PG synthesis. Whether this was due to the presence of anabolic and catabolic factors in these fluids is discussed. Piroxicam had no adverse effect on the PGs of human cartilage in vitro. Piroxicam prevented the cartilage PG depletion when it was induced by the CM from RASF cells.