Circadian regulation of intracellular G-protein signalling mediates intercellular synchrony and rhythmicity in the suprachiasmatic nucleus

Synchronous oscillations of thousands of cellular clocks in the suprachiasmatic nucleus (SCN), the circadian centre, are coordinated by precisely timed cell–cell communication, the principle of which is largely unknown. Here we show that the amount of RGS16 (regulator of G protein signalling 16), a protein known to inactivate Gαi, increases at a selective circadian time to allow time-dependent activation of intracellular cyclic AMP signalling in the SCN. Gene ablation of Rgs16 leads to the loss of circadian production of cAMP and as a result lengthens circadian period of behavioural rhythm. The temporally precise regulation of the cAMP signal by clock-controlled RGS16 is needed for the dorsomedial SCN to maintain a normal phase-relationship to the ventrolateral SCN. Thus, RGS16-dependent temporal regulation of intracellular G protein signalling coordinates the intercellular synchrony of SCN pacemaker neurons and thereby defines the 24 h rhythm in behaviour

Change in brain plasmalogen composition by exposure to prenatal undernutrition leads to behavioral impairment of rats.

Epidemiological studies suggest that poor nutrition during pregnancy influences offspring predisposition to experience developmental and psychiatric disorders. Animal studies have shown that maternal undernutrition leads to behavioral impairment, which is linked to alterations in monoaminergic systems and inflammation in the brain. In this study, we focused on the ethanolamine plasmalogen of the brain as a possible contributor to behavioral disturbances observed in offspring exposed to maternal undernutrition. Maternal food or protein restriction between gestational day (GD) 5.5 and GD 10.5 resulted in hyperactivity of rat male adult offspring. Genes related to the phospholipid biosynthesis were found to be activated in the prefrontal cortex (PFC), but not in the nucleus accumbens or striatum, in the offspring exposed to prenatal undernutrition. Corresponding to these gene activations, increased ethanolamine plasmalogen (18:0p-22:6) was observed in the PFC using mass spectrometry imaging. A high number of crossings and the long time spent in the center area was observed in the offspring exposed to prenatal undernutrition and was mimicked in adult rats via the intravenous injection of ethanolamine plasmalogen (18:0p-22:6) incorporated into the liposome. Additionally, plasmalogen (18:0p-22:6) increased only in the PFC, and not in the nucleus accumbens or striatum. These results suggest that brain plasmalogen is one of the key molecules to control behavior and its injection using liposome is a potential therapeutic approach for cognitive impairment.Significance Statement:Maternal undernutrition correlates to developmental and psychiatric disorders. Here, we found that maternal undernutrition in early pregnancy led to hyperactivity in rat male offspring and induced gene activation of phospholipid-synthesizing enzyme and elevation of ethanolamine plasmalogen (18:0p-22:6) level in the prefrontal cortex (PFC). Intravenous injection of ethanolamine plasmalogen (18:0p-22:6) incorporated into the liposome maintained crossing activity and was circumscribed to the center area for a long time period, in prenatally undernourished offspring with aberrant behavior. Furthermore, the amount of ethanolamine plasmalogen (18:0p-22:6) increased in the PFC of the rat after injection. Our result suggests that brain plasmalogen is one of the key molecules to control behavior and that its injection using liposome is a potential therapeutic approach for cognitive impairment

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

Role of α2δ3 in Cellular Synchronization of the Suprachiasmatic Nucleus Under Constant Light Conditions

By the effort to identify candidate signaling molecules important for the formation of robust circadian rhythms in the suprachiasmatic nucleus (SCN), the mammalian circadian center, here we characterize the role of α2δ proteins, synaptic molecules initially identified as an auxiliary subunit of the voltage dependent calcium channel, in circadian rhythm formation. In situ hybridization study demonstrated that type 3 α2δ gene (α2δ3) was strongly expressed in the SCN. Mice without this isoform (Cacna2d3⁻/⁻) did not maintain proper circadian locomotor activity rhythms under a constant light (LL) condition, whereas under a constant dark (DD) condition, these mice showed a similar period length and similar light-responsiveness as compared to wild type mice. Reflecting this behavioral phenotype, Cacna2d3⁻/⁻ mice showed a severely impaired Per1 expression rhythm in the SCN under LL, but not under DD. Cultured SCN slices from Per1-luc transgenic Cacna2d3⁻/⁻ mice revealed reduced synchrony of Per1-luc gene expression rhythms among SCN neurons. These findings suggest that α2δ3 is essential for synchronized cellular oscillations in the SCN and thereby contributes to enhancing the sustainability of circadian rhythms in behavior

Glucosamine induces autophagy via an mTOR-independent pathway.

Autophagy is a cellular process that nonspecifically degrades cytosolic components and is involved in many cellular responses. We found that amino sugars with a free amino group such as glucosamine, galactosamine and mannosamine induced autophagy via an mTOR-independent pathway. Glucosamine-induced autophagy at concentrations of at least 500 microM to over 40 mM. In the presence of 40 mM glucosamine, autophagy induction was initiated at 6h and reached a plateau at 36 h. Glucosamine-induced autophagy could remove accumulated ubiquitin-conjugated proteins as well as 79-glutamine repeats. Therefore, orally administered glucosamine could contribute to the prevention of neurodegenerative diseases and promotion of antiaging effects

Serotonin receptor 4 (5-hydroxytryptamine receptor Type 4) regulates expression of estrogen receptor beta and cell migration in hormone-naive prostate cancer

Background: Estrogens are considered to potentially play some roles in the development and progression of prostate cancer through estrogen receptor beta (ERβ). However, additional factors which could influence the clinical outcome of the patients through modulating these steroid signalings have also been proposed. Among these, increased expression of serotonin receptor especially that of 5-hydroxytryptamine receptor Type 4 (5-HTR4) has been recently proposed to be involved in autocrine/paracrine mechanisms of castration-resistant prostate cancer, but the presence and clinical significance of 5-HTR4 in hormone-naive prostate cancer (HNPC) and its interaction with hormonal signaling pathways have remained virtually unknown. Materials and Methods: We evaluated the status of 5-HTR4 in 112 human HNPC cases (acinar adenocarcinoma) using immunohistochemistry and correlated the findings with clinicopathological features of individual patients and the status of androgen receptor (AR) and ERβ. To further elucidate its underlying mechanisms, androgen-dependent human prostate carcinoma cell line, LNCaP, expressing 5-HTR4, was treated by 5-HTR4 agonist. Results: 5-HTR4 immunoreactivity was detected in 34% of prostate cancer cases examined (38/112) and was significantly correlated with the status of ERβ but not with that of AR and other clinicopathological factors of the patients. Results of in vitro studies demonstrated that 24 h incubation with 5-HTR4 agonist (10 nM) increased the expression level of ERβ messenger RNA compared to controls. 5-HTR4 agonist (100 nM) significantly inhibited LNCaP carcinoma cell migration (P < 0.05). Conclusion: Results of our present study indicated that 5-HTR4 signaling upregulated ERβ expression in HNPCs and could impact on biological processes in HNPC

MALDI imaging mass spectrometry revealed atropine distribution in the ocular tissues and its transit from anterior to posterior regions in the whole-eye of rabbit after topical administration.

It is essential to elucidate drug distribution in the ocular tissues and drug transit in the eye for ophthalmic pharmaceutical manufacturers. Atropine is a reversible muscarinic receptor used to treat various diseases. However, its distribution in ocular tissues is still incompletely understood. Matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS) evaluates drug distribution in biological samples. However, there have been few investigations of drug distribution in ocular tissues, including whole-eye segments. In the present study, we explored the spatial distribution of atropine in the whole-eye segment by MALDI-IMS, and then evaluated the changes in atropine level along the anterior-posterior and superior-inferior axes. A 1% atropine solution was administered to a rabbit and after 30 min, its eye was enucleated, sectioned, and analyzed by MALDI-IMS. Atropine accumulated primarily in the tear menisci but was found at substantially lower concentrations in the tissue surrounding the conjunctival sacs. Relative differences in atropine levels between the anterior and posterior regions provided insights into the post-instillation behavior of atropine. Atropine signal intensities differed among corneal layers and between the superior and inferior eyeball regions. Differences in signal intensity among tissues indicated that the drug migrated to the posterior regions via a periocular-scleral route. Line scan analysis elucidated atropine transit from the anterior to the posterior region. This information is useful for atropine delivery in the ocular tissues and indicates that MALDI-IMS is effective for revealing drug distribution in whole-eye sections

Circadian characteristics of mice depleted with GPR7

金沢大学医薬保健研究域医学系GPR7, now known as a receptor of neuropeptide B and neuropeptide W, is expressed in neurons of the suprachiasmatic nucleus (SCN), the mammalian circadian center. By the quantitative in situ hybridization, we demonstrated that GPR7 mRNA showed a significant circadian rhythm in the SCN showing a peak at early subjective night in both light-dark and constant dark. We characterized the circadian feature of GPR7-knockout mice, but the period length and the phase-dependent phase shift to light exposure were not disordered in GPR7-knockout mice. Moreover, the food-anticipatory behavior in restricted feeding schedule was observed in this gene-deleted mouse similar to wild-type. These results indicate that the role of GPR7 may be subtle or limited in relation to the circadian clock despite its robust expression in the SCN