Interrelationships among brain,endocrine and immune response in ageing and successful ageing: role of metallothionein III isoform

Metallothionein-III (MT-III) a brain-specific member of metallothionein family contributes to zinc neuronal homeostasis, and zinc is an important regulator of many brain functions, including the activity of hormone realising factors by hippocampus. Among them, somatostatin is pivotal because affecting thyroid hormones turnover and consequently thymic and peripheral immune efficiency (Natural Killer, NK) cell activity. Somatostatin is in turn affected by somatomedin-C, which is also zinc-dependent. Therefore, somatomedin-C may be a marker of somatostatin status in the hippocampus. MTs sequester and release zinc in transient stress, as it may occur in young age, to protect cells by reactive oxygen species. In order to accomplish this task, MTs are induced by IL-6 for a prompt immune and anti-inflammatory response. During ageing, MTs are high with a role of sequester of zinc, but with very limited role in zinc release because stress-like condition and inflammation is persistent. Therefore, high MTs may become to protective in young age to harmful during ageing leading to low zinc ion bioavailability for many body homeostatic mechanisms, including brain function. As a consequence, an altered physiological cascade from the brain (upstream) to endocrine and immune system (downstream) may occur. The aim of this work is to study the role of MT-III in the interrelationships among brain-endocrine-immune response in ageing and successful ageing. The main results are: (1) MT-III and IL-6 gene expressions increase in the hippocampus from old mice, in comparison with young and very old mice. (2) Somatomedin-C plasma levels decrease in old mice in comparison with young and very old mice. (3) Low zinc ion bioavailability (tested by the ratio total thymulin/active thymulin) is coupled with altered thyroid hormone turnover and depressed IL-2 in old mice in comparison with young and very old mice. (4) 'In vitro' experiments display more increments on NK cells activity by adding zinc-bound active thymulin than T3 alone. In conclusion, low MT-III in the hippocampus from young and very old mice leads to good zinc ion bioavailability that it is upstream coupled with normal hippocampal function affecting downstream normal thyroid hormones turnover and satisfactory NK cell activity, via complete saturation of zinc-bound active thymulin molecules. Therefore, a correct MTs homeostasis is pivotal for brain-endocrine-immune response in order to reach successful ageing.     

猕猴骨髓干细胞动员后外周血干细胞、免疫细胞亚群及细胞因子变化

目的:观察GM-CSF动员猕猴骨髓干细胞后外周血干细胞、免疫细胞亚群和细胞因子含量的动态变化,为临床干细胞动员及用于治疗疾病提供参考依据.方法:健康猕猴连续5 d,皮下注射GM-CSF 8 μg/(kg·d),分别于0、2、4、6、8、10 d采集外周血,血细胞分析仪计数白细胞(WBC)总数、淋巴细胞和中性粒细胞比例,流式细胞术(FCM)测定CD34 、CD133 、CD3 、CD4 、CD8 、CD56 细胞比例,酶联免疫分析法测定血清TNF-α、IL-1β、IL-2含量.结果:WBC、中性粒细胞、CD34 、CD133 细胞数量和比例均同步升高(P＜0.01),到动员第6天时达到高峰,细胞数量分别为正常水平的6.4、9.1、117和163.3倍,其中CD34 、CD133 第8天时恢复正常,而WBC、中性粒细胞仍高于正常水平(P＜0.05).CD3 、CD4 、CD8 、CD56 细胞的数量增加,细胞数在第6天时分别为动员前的4.1、4.0、2.9和4.3倍,但比例下降(P＜0.01),到第6天达到最低(P＜0.001),随后逐渐升高至正常以上水平并持续至第10天(P＜0.05).TNF-α、IL-1β、IL-2浓度于动员后6 d内明显升高(P＜0.01),其中TNF-α、IL-1β浓度至8 d恢复正常(P＞0.05),IL-2浓度升高幅度较大并至少持续至第10天(P＜0.01).结论:连续5 d动员猕猴骨髓干细胞可使外周血中CD34 、CD133 细胞比率短暂升高,WBC、中性粒细胞比例持续升高,使CD3 、CD4 、CD8 、CD56 细胞绝对数增加,TNF-α、IL-1β、IL-2浓度升高,表明GM-CSF动员猕猴骨髓干细胞可在细胞和免疫调节因子水平提高免疫功能.     

Effect of ageing on pulmonary inflammation, airway hyperresponsiveness and T and B cell responses in antigen-sensitized and -challenged mice

BACKGROUND: The effect of ageing on several pathologic features of allergic asthma (pulmonary inflammation, eosinophilia, mucus hypersecretion), and their relationship with airway hyperresponsiveness (AHR) is not well characterized. OBJECTIVE: To evaluate lung inflammation, mucus metaplasia and AHR in relationship with age in murine models of allergic asthma comparing young and older mice. METHODS: Young (6 weeks) and older (6, 12, 18 months) BALB/c mice were sensitized and challenged with ovalbumin (OVA). AHR and bronchoalveolar fluid (BALF), total inflammatory cell count and differential were measured. To evaluate mucus metaplasia, quantitative PCR for the major airway mucin-associated gene, MUC-5AC, from lung tissue was measured, and lung tissue sections stained with periodic acid-Schiff (PAS) for goblet-cell enumeration. Lung tissue cytokine gene expression was determined by quantitative PCR, and systemic cytokine protein levels by ELISA from spleen-cell cultures. Antigen-specific serum IgE was determined by ELISA. RESULTS: AHR developed in both aged and young OVA-sensitized/challenged mice (OVA mice), and was more significantly increased in young OVA mice than in aged OVA mice. However, BALF eosinophil numbers were significantly higher, and lung histology showed greater inflammation in aged OVA mice than in young OVA mice. MUC-5AC expression and numbers of PAS+ staining bronchial epithelial cells were significantly increased in the aged OVA mice. All aged OVA mice had increased IL-5 and IFN-gamma mRNA expression in the lung and IL-5 and IFN-gamma protein levels from spleen cell cultures compared with young OVA mice. OVA-IgE was elevated to a greater extent in aged OVA mice. CONCLUSIONS: Although pulmonary inflammation and mucus metaplasia after antigen sensitization/challenge occurred to a greater degree in older mice, the increase in AHR was significantly less compared with younger OVA mice. Antigen treatment produced a unique cytokine profile in older mice (elevated IFN-gamma and IL-5) compared with young mice (elevated IL-4 and IL-13). Thus, the airway response to inflammation is lessened in ageing animals, and may represent age-associated events leading to different phenotypes in response to antigen provocation.     

Lymphocyte activation in human ageing: V. Acquisition of response to T cell growth factor and production of growth factors by mitogen-stimulated lymphocytes

In order to ascertain why the T cell proliferative response declines with ageing, the age-related quality of the interleukin II (Il-2)-mediated signal during lymphocyte activation was investigated in mitogen-stimulated peripheral blood mononuclear cells (PBMC) from old (over 70 years) and adult (20-40 years) subjects. Both the Il-2 properties of supernatants produced by phytohaemagglutinin (PHA)-stimulated PBMC on Il-2 sensitive cells and the PHA-induced transformation in Il-2 sensitive T cells were decreased in the old subjects. Supplements with human Il-2 enhanced the DNA synthesis by PHA-, concanavalin-A-, or pokeweed-mitogen-activated lymphocytes in the two groups of subjects. The addition of Il-2 to old cultures restored a response similar to that observed in adults cells cultured without exogenous Il-2. The similarity of the dose-response curves to interleukin II indicated the unaltered affinity of the specific membrane receptors to the humoral factors. These findings strongly suggest that the immune deficiency commonly found in the elderly results principally from a selective alteration of the hormonal step of lymphocyte activation.     

Effects of plane of nutrition and arginine on ovarian follicles in non-pregnant sheep: Cell proliferation,and expression of endothelial nitric oxide and its receptor

The aim of this study was to investigate the role of the nitric oxide (NO) system in ovarian function, by determining if arginine (Arg) supplementation impacts follicle number, cell proliferation, and expression of the NO system members in nutritionally compromised ewes. Ewes were randomly assigned into maintenance (C, 100% requirements), excess (O; 2xC), or restricted (U; 0.6xC) diets 8 weeks prior to Arg treatment. Ewes were individually fed twice daily with pelleted diets. Ewes from each nutritional group were randomly assigned to one of two treatments: saline or Arg, which was initiated on day 0 of the estrous cycle and administered 3 times per day. Ovaries were collected at the early-luteal, mid-luteal and late-luteal/follicular phases of the estrous cycle to determine 1) the number of surface follicles, 2) follicle cell proliferation marked by Ki67 protein expression, and 3) expression of endothelial nitric oxide (eNOS; NOS3) and soluble guanylyl cyclase beta (sGC; GUCY1B3) protein and mRNA in granulosa (G) and theca (T) layers using immunohistochemistry followed by image analysis and qPCR, respectively. During nutritional treatment, C maintained body weight, O gained 6±1.2 kg, and U lost 14±1.3 kg. Our data show that: 1) Ki67 was expressed in all ovarian compartments, eNOS protein was detected in blood vessels of T and stroma, and sGC protein was detected in T cells, and blood vessels of T layer and other ovarian compartments; 2) plane of nutrition affected the number of surface follicles, and thus folliculogenesis, cell proliferation in the T layer, eNOS and sGC protein expression in T, and NOS3 and GUCY1B3 mRNA expression in G; 3) Arg treatment affected cell proliferation in G and T, eNOS and sGC protein expression in T, mRNA expression of NOS3 in T in all groups, and GUCY1B3 in G depending on the stage of the estrous cycle; and 4) G and T cell proliferation, and expression of eNOS and sGC protein in T was affected by the stage of the estrous cycle. Our data demonstrated that plane of nutrition and Arg are involved in the regulation of follicular functions in non-pregnant sheep.     

A review of the equine age-related changes in the immune system: Comparisons between human and equine aging,with focus on lung-specific immune-aging

The equine aging process involves many changes to the immune system that may be related to genetics, the level of nutrition, the environment and/or an underlying subclinical disease. Geriatric horses defined as horses above the age of 20, exhibit a decline in body condition, muscle tone and general well-being. It is not known whether these changes contribute to decreased immune function or are the result of declining immune function. Geriatric years are characterized by increased susceptibility to infections and a reduced antibody response to vaccination as a result of changes in the immune system. Humans and horses share many of these age-related changes, with only a few differences. Thus, inflamm-aging and immunosenescence are well-described phenomena in both human and equine research, particularly in relation to the peripheral blood and especially the T-cell compartment. However, the lung is faced with unique challenges because of its constant interaction with the external environment and thus may not share similarities to peripheral blood when considering age-related changes in immune function. Indeed, recent studies have shown discrepancies in cytokine mRNA and protein expression between the peripheral blood and bronchoalveolar lavage immune cells. These results provide important evidence that age-related immune changes or ‘dys-functions’ are organ-specific.     

The effects of biofeedback-assisted relaxation on cell-mediated immunity,cortisol, and white blood cell count in healthy adult subjects

The effect of biofeedback-assisted relaxation on cell-mediated immunity, cortisol, and white blood cell count was investigated in healthy adults under low-stress conditions. Fourteen subjects were trained with biofeedback-assisted relaxation for 4 weeks, while 17 subjects were controls. The group trained in relaxation techniques showed increased blastogenesis, decreased white blood cell count, due to decreased neutrophils, and no change in cortisol in comparison to the control group. Subjects with lower initial anxiety scores and forehead muscle tension levels showed larger increases in blastogenesis and larger decreases in neutrophils than subjects with higher initial anxiety and muscle tension levels.