T细胞和B细胞对骨代谢的影响

免疫系统的T、B细胞通过影响破骨细胞的激活与分化,影响骨重建过程。Th17细胞可促进破骨细胞分化,Treg细胞可抑制破骨细胞生成,Th1/2细胞则可能具有双向作用。在不同疾病环境下,B细胞具有促进或抑制破骨细胞的作用。类风湿关节炎患者的T细胞促进破骨细胞生成,使成熟成骨细胞无法形成,导致类风湿关节炎特征性的骨丢失。绝经后骨质疏松患者T、B细胞高表达RANKL,引起破骨细胞分化增殖,雌激素可能通过抑制RANKL/RANK/OPG轴起抗骨丢失作用。     

破骨细胞分化发育中的信号转导及转录因子研究进展

破骨细胞是骨组织中特有的一种多核细胞,在骨吸收过程中起重要作用。破骨细胞分化过程中,巨噬细胞集落刺激因子（M-CSF）与细胞核因子κB受体活化因子配基（RANKL）结合于细胞表面受体上,提供破骨细胞存活、增殖的信号并激活相应的信号转导通路,使分化中的破骨细胞表达特异性基因,使成熟的破骨细胞执行骨吸收功能。在此过程中,转录因子（PU．1）、核转录因子κB（NF-κB）、活化T细胞核因子c1（NFATc1）、     

阻断酸敏感离子通道1a对酸诱导的破骨细胞形成及其骨吸收的影响

目的观察酸敏感离子通道1a(acid-sensing ion channel 1a,ASIC1a)介导酸诱导的破骨细胞形成和骨吸收的作用。方法建立巨噬细胞集落刺激因子(maerophage colony stimulating factor,M-CSF)和细胞分化因子(receptor activator of nuclear foetor-κB ligand,RANKL)体外诱导骨髓单核细胞分化为破骨细胞,慢病毒为载体转染细胞沉默ASIC1a,并通过抗酒石酸酸性磷酸酶(tartrate-resistant acid phosphatase,TRACP)染色和骨吸收实验检测破骨细胞的形成及其骨吸收功能,采用Western blotting法检测活化T细胞核因子c1(nuclear factor of activated T-cells cytoplasmic 1,NFATc1)蛋白的表达。结果阻断ASIC1a可明显抑制酸诱导的破骨细胞的形成及其骨吸收功能(P=0.000),阻断ASIC1a可抑制酸诱导的NFATc1蛋白表达(P=0.000)。结论阻断ASIC1a对酸诱导的破骨细胞形成和骨吸收具有明显抑制作用,其机制可能是抑制转录因子NFATc1蛋白的表达。     

糖尿病对大鼠种植体周围OPG和RANKL表达的影响

建立糖尿病大鼠实验动物模型成功后，将大鼠分为糖尿病种植组（T组），糖尿病对照组（T0组），正常种植组（C组），正常对照组（C0组）。T组及C组的胫骨近骺端种植纯钛种植体，分别于植入后1、2周处死动物，采用免疫组化和实时定量PCR方法检测种植体周围骨组织中骨保护因子（OPG）和破骨细胞核因子kB受体活化因子配体（RANKL）的表达。结果OPG和RANKL表达在骨基质、成骨细胞及骨髓基质细胞中，T、C组阳性信号增强，髓腔内更加明显；T、T0组大鼠皮质骨孔隙明显多于C、C0组。T、C组第1、2周OPG均较C0组增加，T组第2周比T0组增加；T组第1、2周RANKL均比C0、T0组增加（p均〈0．05）。提示糖尿病可能通过OPG和RANKL通路使种植体植入周围骨组织中破骨细胞的形成增加，削弱了糖尿病种植体与周围骨组织的骨整合。     

雌激素对成骨细胞、破骨细胞作用的新进展

成骨细胞和破骨细胞均表达雌激素受体,但雌激素对两者的作用远未阐明.雌激素能诱导成骨细胞产生骨保护素(osteoprotegerin,OPG).当雌激素缺乏时,T细胞分泌TNF和IL-7等增加,作用于破骨细胞加速骨丢失;绝经后FSH升高,可直接作用于破骨细胞增强其功能.雌激素亦可通过非基因组效应减缓成骨细胞凋亡,加速破骨细胞凋亡.最近研究发现,雌激素通过ERα可直接阻止骨丢失,可能机制是诱导成骨细胞和破骨细胞表达FasL,以旁分泌和自分泌的方式促进破骨细胞凋亡.     

甲状旁腺素相关肽对骨髓基质细胞中RANKL及OPG基因的表达影响

目的 研究甲状旁腺素相关肽(PTHrP)对骨髓基质细胞RANKL／OPG基因表达的影响。方法 分离小鼠骨髓细胞后，45ng／ml的PTHrP刺激，第6天时观察破骨细胞生成情况。90ng／mlPTHrP刺激贴壁鼠骨髓基质细胞3d和6d，实时荧光PCR检测破骨细胞分化因子RANKL及骨保护素OPG基因的表达情况。结果在PTHrP的刺激下，大量破骨细胞生成。骨髓基质细胞在PTHrP的刺激下，RANKI基因表达升高，OPG基因表达降低。结论 PTHrP刺激破骨细胞生成是通过上调RANKI基因表达，下调OPG基因的表达实现的。     

骨质疏松相关基因在骨质疏松中的作用

骨质疏松（osteoporosis OP)是以骨质量的丢失以及骨组织的退变为特征的骨代谢疾病。近年来，骨质疏松相关基因如：维生素D受体（VDR）基因型，雌激素受体（ER）基因型，I型胶原A1（COLIAI）基因型，骨钙素基因，白细胞介素基因等在骨质疏松的形成和转归方面的作用日益成为人们关注的焦点。 雌激素可以增加破骨细胞的产物－转移生长因子β1（TGF-β1）在骨中富含，对病人带有的T等位基因发挥作用。中国妇女的BMD与VDR基因型有关。白细胞介素1（IL－1）是促进皮骨细胞的骨吸收作用因子，它随雌激素的减少而增加；在成骨细胞中近似于对雌激素的受体后效应，还可以促进破骨细胞凋亡，这种多效性维持着骨的稳态（homeostasis）。     

RANKL诱导破骨细胞前体细胞分化成熟

目的 用核因子-κB受体活化因子配体(RANKL)诱导破骨细胞前体细胞分化成熟,建立获取成熟破骨细胞的方法.方法 用破骨细胞前体细胞RAW264.7细胞为模型,RANKL诱导培养4～9 d,抗酒石酸酸性磷酸酶(TRAP)染色观察TRAP阳性多核细胞形成,罗丹明-鬼笔环肽荧光染色观察纤维性肌动蛋白(F-actin)环,DAPI染色观察细胞核,甲苯胺蓝染色观察牛骨片表面的吸收陷窝情况.结果 RANKL可诱导RAW264.7细胞形成TRAP染色阳性的多核细胞,形成F-actin环,骨片吸收陷窝明显.结论 RANKL可诱导RAW264.7细胞向成熟破骨细胞分化,该诱导模型可用于破骨细胞分化研究.     

类风湿关节炎滑膜细胞向破骨细胞分化实验研究

目的观察类风湿关节炎(RA)滑膜组织中破骨细胞来源以及核因子κB受体活化子配体(RANKL)在诱导破骨细胞分化过程中的作用。方法取6例RA和6名正常关节的滑膜组织,用胶原酶消化法获得滑膜细胞,通过免疫磁珠法分选获得CD68+/-滑膜细胞。用外源性RANKL16μg/L、巨细胞集落刺激因子(M-CSF)25μg/L及地塞米松醋酸酯1×10-8mol/L诱导各组滑膜细胞分化。通过抗酒石酸酸性磷酸酶(TRAP)染色、降钙素受体(CTR)免疫荧光检测、骨吸收陷窝形成方法鉴定破骨细胞。并在RA滑膜CD68+细胞中加入0~8ng/ml梯度浓度的RANKL,观察不同浓度RANKL对RA滑膜CD68+细胞分化的影响。结果RA滑膜CD68+细胞在RANKL诱导14d后,RA滑膜CD68+细胞组出现CTR阳性、TRAP染色阳性细胞并有骨吸收陷窝形成。RA滑膜CD68+细胞在体外经RANKL诱导后分化形成的破骨细胞功能与RANKL剂量有关。结论RA滑膜组织中前体破骨细胞来源于滑膜CD68+细胞,在体外RANKL诱导下可以分化为成熟破骨细胞。RANKL体外诱导剂量影响RA滑膜CD68+细胞分化功能。     

巴戟天含药血清对成骨-破骨细胞共育体系原癌基因、核心结合因子1mRNA表达的影响

目的观察不同浓度巴戟天含药血清对体外培养成骨-破骨细胞共育体系中原癌基因(C-FOS)、核心结合因子(Cbfa)1 mRNA表达的影响。方法提取24 h内新生SD乳鼠颅盖骨分离培养成骨细胞,采用5周龄SD大鼠双侧股骨、胫骨的骨髓基质细胞,加入集落细胞刺激因子(M-CSF)和细胞核因子κB受体活化因子配体(RANKL)诱导培养破骨细胞。采用碱性磷酸酶(ALP)染色鉴定成骨细胞,抗酒石酸酸性磷酸酶(TRAP)染色、骨吸收陷窝甲苯胺蓝染色、电镜扫描等鉴定破骨细胞,体外建立成骨-破骨细胞共育体系,设置低、中、高三种浓度巴戟天含药血清组和不含药血清组,干预3 d后提取各组总RNA,应用逆转录-聚合酶链反应(RT-PCR)方法测定各组C-FOS、Cbfa1 mRNA表达量。结果不同浓度巴戟天含药大鼠血清对成骨-破骨细胞共育体系C-FOS有抑制作用,对Cbfa1 mRNA的表达有促进作用。高浓度含药血清组两者的表达差异显著(P<0.05,P<0.000 1)。结论巴戟天含药血清可抑制成骨-破骨细胞共育体系C-FOS的表达,促进Cbfa1 mRNA的表达,从而达到降低破骨细胞分化成熟及骨吸收活性,促进骨形成。     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Variabilité des concentrations plasmatiques de l’angiotensinogène et risque d’hypertension artérielle chez le rat transgénique

Aim

Genetic polymorphisms of the human angiotensinogen gene are frequent and may induce up to 30% increase of plasma angiotensinogen concentrations with a blood pressure increase of up to 5 mmHg. Their role for the pathogenesis of human arterial hypertension remains unclear. High plasma angiotensinogen levels could increase the sensitivity to other blood pressure stressors.

Methods

Male transgenic rats with a 9-fold increase of plasma angiotensinogen concentrations and male non-transgenic rats aged 10 weeks were treated or not with NG-Nitro-L-arginine-methyl ester for 3 weeks in their drinking water (n = 3/group). Systolic blood pressure and body weight were measured at baseline and at the end of the study when left ventricular weight and ventricular expression of angiotensin I-converting enzyme and procollagen Iα1 were determined (polymerase chain reaction).

Results

At baseline, transgenic rats had +18 mmHg higher bood pressure and –8% lower body weight compared to non-transgenic rats (P < 0.05) without significant changes for the vehicle groups throughout the study (P > 0.05). NG-Nitro-L-arginine-methyl ester increased blood pressure, left ventricular weight and left ventricular weight indexed for body weight by +41%, +17.6% and +18.6% (P < 0.05) in transgenic and +25%, +5.3% and +6.7% (P > 0.05) in non-transgenic rats compared to untreated animals, respectively. Cardiac gene expression showed no differences between groups (P > 0.05).

Conclusion

Increased plasma angiotensinogen levels may sensitize to additional blood pressure stressors. Our preliminary results point towards an independent role of angiotensinogen in the pathogenesis of human hypertension and associated end-organ damage.