Chronic Restraint Stress Inhibits Hair Growth via Substance P Mediated by Reactive Oxygen Species in Mice

Backgrounds

Solid evidence has demonstrated that psychoemotional stress induced alteration of hair cycle through neuropeptide substance P (SP) mediated immune response, the role of reactive oxygen species (ROS) in brain-skin-axis regulation system remains unknown.

Objectives

The present study aims to investigate possible mechanisms of ROS in regulation of SP-mast cell signal pathway in chronic restraint stress (CRS, a model of chronic psychoemotional stress) which induced abnormal of hair cycle.

Methods and Results

Our results have demonstrated that CRS actually altered hair cycle by inhibiting hair follicle growth in vivo, prolonging the telogen stage and delaying subsequent anagen and catagen stage. Up-regulation of SP protein expression in cutaneous peripheral nerve fibers and activation of mast cell were observed accompanied with increase of lipid peroxidation levels and reduction of the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in CRS mice skin. In addition, SP receptor antagonist (RP67580) reduced mast cell activations and lipid peroxidation levels as well as increased GSH-Px activity and normalized hair cycle. Furthermore, antioxidant Tempol (a free radical scavenger) also restored hair cycle, reduced SP protein expression and mast cell activation.

Conclusions

Our study provides the first solid evidence for how ROS play a role in regulation of psychoemotional stress induced SP-Mast cell pathway which may provide a convincing rationale for antioxidant application in clinical treatment with psychological stress induced hair loss.     

束缚应激对大鼠同型半胱氨酸代谢的影响

为了探讨束缚应激对大鼠血清含硫氨基酸代谢的影响,根据同型半胱氨酸(Hcy)水平,将32只雄性Wistar大鼠分为对照组(control)、束缚应激组(RS)、1%蛋氨酸组(1%Met)和1%蛋氨酸+束缚应激组(1%Met+RS)。采用高压液相色谱法检测血清中的Hcy、半胱氨酸(Cys)和还原型谷胱甘肽(GSH)含量,采用全自动氨基酸分析仪测定血清中蛋氨酸(Met)和牛磺酸(Tau)含量。结果显示,RS组大鼠血清Hcy、Cys和GSH含量随着束缚时间延长而降低,且较对照组和1%蛋氨酸组有显著性差异(p<0.05);RS组大鼠血清Met和Tau含量较对照组和1%蛋氨酸组则显著升高(p<0.05)。束缚应激可能降低血清抗氧化能力和总Hcy水平。     

Effect of Chronic Psychological Stress on Liver Metastasis of Colon Cancer in Mice

Metastasis to the liver is a main factor in colorectal cancer mortality. Previous studies suggest that chronic psychological stress is important in cancer progression, but its effect on liver metastasis has not been investigated. To address this, we established a liver metastasis model in BALB/c nude mice to investigate the role of chronic stress in liver metastasis. Our data suggest that chronic stress elevates catecholamine levels and promotes liver metastasis. Chronic stress was also associated with increased tumor associated macrophages infiltration into the primary tumor and increased the expression of metastatic genes. Interestingly, β-blocker treatment reversed the effects of chronic stress on liver metastasis. Our results suggest the β-adrenergic signaling pathway is involved in regulating colorectal cancer progression and liver metastasis. Additionally, we submit that adjunctive therapy with a β-blocker may complement existing colorectal cancer therapies.     

罗格列酮对裸鼠移植性人肝癌细胞生长的抑制作用

目的:研究罗格列酮(rosiiglitazone,ROZ)对裸鼠体内人肝癌SMMC7721细胞增殖的影响.方法:建立人肝癌裸鼠移植瘤模型,实验动物分为罗格列酮治疗组及对照组.观察罗格列酮对移植瘤体积和重量的变化,采用光镜观察移植瘤细胞形态学变化,流式细胞术检测移植瘤细胞周期分布,免疫组织化学和蛋白印迹检测瘤组织内增殖细胞核抗原(proliferating cellnuclear antigen,PCNA)蛋白表达变化.结果:罗格列酮在体内能明显抑制移植瘤的生长,抑瘤率为50.81%;组织学显示治疗组瘤细胞异型性降低,核质比下降;流式细胞术分析显示,对照组移植瘤细胞处于G2/M期细胞为13.1%,与对照组比较,治疗组处于G2/M期细胞显著增多(29.1%).免疫组织化学和蛋白印迹检测均显示检测显示,经罗格列酮处理后,裸鼠移植瘤组织PCNA蛋白表达明显下调(P＜0.05).结论:罗格列酮可体内抑制人肝癌SMMC7721细胞增殖,并使癌细胞阻滞于G2/M期.     

The Effect of Social Stress on Chronic Pain Perception in Female and Male Mice

The current investigations on social stress primarily point to the negative health consequences of being in a stressful social hierarchy. The repetitive nature of such stressors seems to affect behavioral response to pain both in rodents and humans. Moreover, a large discrepancy in the possibility of social stresses affecting pain perception in the two genders exists. The present study examined the effect of chronic social stress on nociceptive responses of both sexes by implementing of food deprivation, food intake inequality and unstable social status (cage-mate change every 3 days) for a period of 14 days in 96 Balb/c mice. In this regard we injected 20 µl formalin 2% into the plantar surface of hind paw at the end of stress period and scored pain behaviors of all subjects, then serum concentrations of proinflammatory cytokines were measured. Our results showed that there was significant difference in chronic phase of formalin test following implementation of food deprivation and inequality (P<0.05) as compared to control group, so that pain perception was decreased considerably and this decline in inequality exposed subjects was well above isolated ones (P<0.05); whereas unstable social situation did not affect pain perception. Moreover, IL-1 and IL-6 concentrations in serum of stressed mice of both genders were well above control group (p<0.05). Finally, despite chronic pain perception in control and unstable male subjects was larger than females; the decrease of chronic pain perception in male stressed animals (poverty and inequality experienced subjects) was much more than stressed females. These results revealed that although food deprivation and social inequality can induce hypoalgesia, some socioeconomic situations like social instability don''t affect pain sensation, whereas there were similar increases of proinflammatory cytokines level in all socially stressed subjects. In addition, males display larger hypoalgesic responses to inequality as compared with females.     

Effect of Chronic Pain on Fentanyl Self-Administration in Mice

The development of opioid addiction in subjects with established chronic pain is an area that is poorly understood. It is critically important to clearly understand the neurobiology associated with propensity toward conversion to addiction under conditions of chronic pain. To pose the question whether the presence of chronic pain influences motivation to self-administer opioids for reward, we applied a combination of rodent models of chronic mechanical hyperalgesia and opioid self-administration. We studied fentanyl self-administration in mice under three conditions that induce chronic mechanical hyperalgesia: inflammation, peripheral nerve injury, and repeated chemotherapeutic injections. Responding for fentanyl was compared among these conditions and their respective standard controls (naïve condition, vehicle injection or sham surgery). Acquisition of fentanyl self-administration behavior was reduced or absent in all three conditions of chronic hyperalgesia relative to control mice with normal sensory thresholds. To control for potential impairment in ability to learn the lever-pressing behavior or perform the associated motor tasks, all three groups were evaluated for acquisition of food-maintained responding. In contrast to the opioid, chronic hyperalgesia did not interfere with the reinforcing effect of food. These studies indicate that the establishment of chronic hyperalgesia is associated with reduced or ablated motivation to seek opioid reward in mice.     

Acute Restraint Stress Enhances Calcium Mobilization and Glutamate Exocytosis in Cerebrocortical Synaptosomes from Mice

Acute stress is known to enhance the memory of events that are potentially threatening to the organisms. Glutamate, the most abundant excitatory neurotransmitter in the mammalian central nervous system, plays a critical role in learning and memory formation and calcium (Ca²⁺) plays an essential role in transmitter release from nerve terminals (synaptosomes). In the present study, we investigated the effects of acute restraint stress on cytosolic free Ca²⁺ concentration ([Ca²⁺]_i) and glutamate release in cerebrocortical synaptosomes from mice. Acute restraint stress caused a significant increase in resting [Ca²⁺]_i and significantly enhanced the ability of the depolarizing agents K⁺ and 4-aminopyridine (4-AP) to increase [Ca²⁺]_i. It also brought about a significant increase in spontaneous (unstimulated) glutamate release and significantly enhanced K⁺- and 4-AP-induced Ca²⁺-dependent glutamate release. The pretreatment of synaptosomes with a combination of ω-agatoxin IVA (a P-type Ca²⁺ channel blocker) and ω-conotoxin GVIA (an N-type Ca²⁺ channel blocker) completely suppressed the enhancements of [Ca²⁺]_i and Ca²⁺-dependent glutamate release in acute restraint-stressed mice. These results indicate that acute restraint stress enhances K⁺- or 4-AP-induced glutamate release by increasing [Ca²⁺]_i via stimulation of Ca²⁺ entry through P- and N-type Ca²⁺ channels.     

Effects of Chronic Restraint Stress on Feeding Behavior and on Monoamine Levels in Different Brain Structures in Rats

Monoaminergic systems are important modulators of the responses to stress. Stress may influence feeding behavior, and the involvement of monoamines in the control of food intake is well recognized. We investigated the effects induced by chronic-restraint stress, 1 h a day, for 40 days, on eating behavior and on monoamines in distinct brain structures. Increased consumption of sweet pellets, and not of peanuts, was observed. Dopamine (DA), serotonin (5–HT), and their metabolites were measured by HPLC-EC. After chronic restraint, the results observed were decreased 5–HT in hippocampus, with increased 5–HIAA/5–HT; decreased 5–HIAA levels in cortex; reduction in DA in hippocampus, and increased levels in amygdala and hypothalamus; HVA increased in cortex, as well as HVA/DA ratio, while DOPAC/DA decreased. HVA decreased in hypothalamus, as well as HVA/DA, and DOPAC/DA and HVA/DA decreased in the amygdala. These results suggest that restraint stress differentially affects the activity of central dopaminergic and serotonergic neurons, and this may be related to the effects observed in eating behavior.     

Effects of Organic Copper on Growth Performance and Oxidative Stress in Mice

Biological Trace Element Research - Copper (Cu) has been used as a feed additive for many years. However, high Cu amounts can cause oxidative stress and adversely affect animal performance. Such...     

3-D Visualization and Quantitation of Microvessels in Transparent Human Colorectal Carcinoma

Microscopic analysis of tumor vasculature plays an important role in understanding the progression and malignancy of colorectal carcinoma. However, due to the geometry of blood vessels and their connections, standard microtome-based histology is limited in providing the spatial information of the vascular network with a 3-dimensional (3-D) continuum. To facilitate 3-D tissue analysis, we prepared transparent human colorectal biopsies by optical clearing for in-depth confocal microscopy with CD34 immunohistochemistry. Full-depth colons were obtained from colectomies performed for colorectal carcinoma. Specimens were prepared away from (control) and at the tumor site. Taking advantage of the transparent specimens, we acquired anatomic information up to 200 μm in depth for qualitative and quantitative analyses of the vasculature. Examples are given to illustrate: (1) the association between the tumor microstructure and vasculature in space, including the perivascular cuffs of tumor outgrowth, and (2) the difference between the 2-D and 3-D quantitation of microvessels. We also demonstrate that the optically cleared mucosa can be retrieved after 3-D microscopy to perform the standard microtome-based histology (H&E staining and immunohistochemistry) for systematic integration of the two tissue imaging methods. Overall, we established a new tumor histological approach to integrate 3-D imaging, illustration, and quantitation of human colonic microvessels in normal and cancerous specimens. This approach has significant promise to work with the standard histology to better characterize the tumor microenvironment in colorectal carcinoma.     

不同时程束缚水浸应激对大鼠胃排空的影响

目的研究不同时程慢性束缚水浸应激对大鼠胃排空的影响。方法48只雄性150 g左右SD大鼠被随机分为6组,即实验3、72、8 d组和对照3、72、8 d组,每组8只。实验期间,每日观察大鼠体重、一般状况及行为学指标。实验组23℃水域箱内束缚水浸1 h/d,对照组自由摄食饮水。采用半固体排空实验（阿拉伯胶炭糊）来检测胃排空率,数据录入SPSS 13.0进行分析处理。结果①体重增加情况：不同组别和不同应激时间这两个因素对体重增加的影响差异均有显著性。②胃排空率：对照各组间比较均无统计学差异。3 d组间（实验3d组与对照3 d组）大鼠胃排空率无差异;而7 d组间和28 d组间比较则明显异常。随着应激时间的延长,实验组胃排空率呈现了先增高（7 d时）后降低（28 d）的变化趋势,且实验3 d组与7 d组、7 d组与28 d组间比较均有明显的统计学意义,而3 d组与28 d组比较则无统计学差异。结论不同时程的慢性束缚水浸应激可以导致大鼠胃排空率改变;随着应激时间的延长,呈现先上升后下降的规律。     

Effects of Restraint Stress on Iron,Zinc, Calcium,and Magnesium Whole Blood Levels in Mice

Objective Study the effects of acute and chronic restraint stress on the whole blood concentrations of iron (Fe), zinc (Zn), calcium (Ca), and magnesium (Mg) in mice. Materials and methods Single or repeat restraints were applied to mice to induce acute or chronic stress. The levels of elements in whole blood were determined by flame atomic absorption spectrometry. Results The levels of Fe, Zn, Ca, and Mg in blood in the acute-stress group were 351, 5.05, 60, and 44 μg/ml, respectively, and those in the corresponding control group were 391, 5.90, 59, and 45 μg/ml, respectively. The levels of blood Fe, Zn, Ca, and Mg in the chronic-tress group were 291, 3.62, 59, and 40 μg/ml, respectively, and those in the corresponding control group were 393, 4.82, 48, and 43 μg/ml, respectively. The levels of Fe and Zn in the blood of both the acute-stress and the chronic-stress groups were significantly lower (P < 0.05) than that in the control groups. The Ca level in whole blood was significantly (P < 0.05) higher in the chronic-stress group than that in the control group. Conclusion Acute and chronic restraint stress can cause changes in blood levels of Fe and Zn in mice.     

Modification of Seed Growth in Soybean by Physical Restraint: Effect on Leaf Senescence

Crafts-Brandner, S. J. and Egli, D. B. 1987. Modification ofseed growth in soybean by physical restraint. Effect on leafsenescence.—J. exp. Bot. 38: 2043–2049. The effect of total plant sink size on leaf senescence in soybean[Glycine max (L.) Merrill] was investigated by using a simple,non-destructive method to decrease seed growth rate and totalplant fruit sink size without altering fruit or seed number.The treatment consisted of placing plastic pod restriction devices(PPRD), which were made from plastic drinking straws (6·35mm diameter), over the fruits so that all of the seeds werecontained within the PPRD's. The treatment did not alter thetime of initiation of leaf senescence for two cultivars (McCalland Maple Amber), but decreased the rate of leaf senescencebased on declines in chlorophyll, ribulose-l,5-hi'sphosphatecarboxylase/oxygenase level and carbon dioxide exchange rate.The treatment also delayed seed maturation. At the time of seedmaturation, the plants still retained green leaves. In a separate experiment, one seed in each fruit (40% of theseeds on the plant) was not restrained by the PPRD's. This treatmentled to an intermediate rate of leaf senescence compared to controland complete seed restriction treatments. The results indicatedthat, for the cultivars examined (1) leaf senescence was initiatedat the same time regardless of sink size (2) the rate of leafsenescence could be modified by altering sink size and (3) seedmaturation could occur without complete leaf yellowing and leafabscission. The effect of the PPRD treatments on leaf senescencewere similar to results obtained when fruits were physicallyremoved, which indicated that physical removal of fruits doesnot lead to artefacts due to wounding of the plants. Key words: Glycine max L, senescence, source-sink     

Combined Effect of Neutron and Proton Radiations on the Growth of Solid Ehrlich Ascites Carcinoma and Remote Effects in Mice

Doklady Biochemistry and Biophysics - The combined effect of the irradiation with a proton pencil scanning beam (PBS) at a total dose of 80 Gy and neutron radiation at a dose of 5 Gy on the growth...     

结直肠癌中DNA甲基化研究进展

CpG岛是人类基因组中富含CpG二核苷酸的DNA序列,主要位于基因启动子区,大小约为100-1000bp,与约60％编码基因相关。DNA中CpG岛甲基化可导致抑癌基因的表观遗传学转录失活,直接参与肿瘤的发生机制。近年来,甲基化已成为表观遗传学研究的焦点。我们简要综述了DNA甲基化在结直肠癌中的研究进展。     

Generation of Subcutaneous and Intrahepatic Human Hepatocellular Carcinoma Xenografts in Immunodeficient Mice

In vivo experimental models of hepatocellular carcinoma (HCC) that recapitulate the human disease provide a valuable platform for research into disease pathophysiology and for the preclinical evaluation of novel therapies. We present a variety of methods to generate subcutaneous or orthotopic human HCC xenografts in immunodeficient mice that could be utilized in a variety of research applications. With a focus on the use of primary tumor tissue from patients undergoing surgical resection as a starting point, we describe the preparation of cell suspensions or tumor fragments for xenografting. We describe specific techniques to xenograft these tissues i) subcutaneously; or ii) intrahepatically, either by direct implantation of tumor cells or fragments into the liver, or indirectly by injection of cells into the mouse spleen. We also describe the use of partial resection of the native mouse liver at the time of xenografting as a strategy to induce a state of active liver regeneration in the recipient mouse that may facilitate the intrahepatic engraftment of primary human tumor cells. The expected results of these techniques are illustrated. The protocols described have been validated using primary human HCC samples and xenografts, which typically perform less robustly than the well-established human HCC cell lines that are widely used and frequently cited in the literature. In comparison with cell lines, we discuss factors which may contribute to the relatively low chance of primary HCC engraftment in xenotransplantation models and comment on technical issues that may influence the kinetics of xenograft growth. We also suggest methods that should be applied to ensure that xenografts obtained accurately resemble parent HCC tissues.     

PLGA-5-氟尿嘧啶缓释微球治疗结直肠癌裸鼠的探讨

目的研究PLGA-5-氟尿嘧啶缓释微球瘤周给药对结直肠癌移植瘤的治疗效果。方法将60只结直肠癌荷瘤鼠随机分为6组,每组10只。A、B组瘤周注射PLGA-5-氟尿嘧啶缓释微球,5-氟尿嘧啶剂量分别为200mg/kg和100 mg/kg;C、D组瘤周注射5-氟尿嘧啶注射液,5-氟尿嘧啶剂量分别为200 mg/kg和100 mg/kg;E组瘤周注射PLGA微球,800 mg/kg;F组不给予任何治疗。于0、3、6、9、12、15d观察裸鼠生存状况、称体重、测量肿瘤大小。15d时处死动物,称瘤重,计算抑瘤率,绘制肿瘤生长曲线;取血行白细胞计数、肝肾功能检查。结果A、B组肿瘤生长曲线平缓,15 d时A、B组肿瘤体积与C、D、E、F组比较,结果差异有显著性,C、D组肿瘤体积与E、F组比较差异无显著性;A、B组抑瘤率分别为75%和62%,与C、D组比较,结果差异有显著性;A、B、C、D、E组体重在0 d及15 d与F组比较,差异无显著性,15 d时各组白细胞计数及肝肾功能检查值均在正常范围。结论PLGA-5-氟尿嘧啶缓释微球瘤周给药能有效抑制结直肠癌移植瘤的生长,且无明显的毒副作用。