Wnt3a upregulates brain-derived insulin by increasing NeuroD1 via Wnt/beta-catenin signaling in the hypothalamus

Background: Insulin plays diverse roles in the brain. Although insulin produced by pancreatic β-cells that crosses the blood-brain barrier is a major source of brain insulin, recent studies suggest that insulin is also produced locally within the brain. However, the mechanisms underlying the production of brain-derived insulin (BDI) are not yet known. Results: Here, we examined the effect of Wnt3a on BDI production in a hypothalamic cell line and hypothalamic tissue. In N39 hypothalamic cells, Wnt3a treatment significantly increased the expression of the Ins2 gene, which encodes the insulin isoform predominant in the mouse brain, by activating Wnt/β-catenin signaling. The concentration of insulin was higher in culture medium of Wnt3a-treated cells than in that of untreated cells. Interestingly, neurogenic differentiation 1 (NeuroD1), a target of Wnt/β-catenin signaling and one of transcription factors for insulin, was also induced by Wnt3a treatment in a time- and dose-dependent manner. In addition, the treatment of BIO, a GSK3 inhibitor, also increased the expression of Ins2 and NeuroD1. Knockdown of NeuroD1 by lentiviral shRNAs reduced the basal expression of Ins2 and suppressed Wnt3a-induced Ins2 expression. To confirm the Wnt3a-induced increase in Ins2 expression in vivo, Wnt3a was injected into the hypothalamus of mice. Wnt3a increased the expression of NeuroD1 and Ins2 in the hypothalamus in a manner similar to that observed in vitro. Conclusion: Taken together, these results suggest that BDI production is regulated by the Wnt/β-catenin/NeuroD1 pathway in the hypothalamus. Our findings will help to unravel the regulation of BDI production in the hypothalamus.1

Valosin-containing protein is a key mediator between autophagic cell death and apoptosis in adult hippocampal neural stem cells following insulin withdrawal

Background: Programmed cell death (PCD) plays essential roles in the regulation of survival and function of neural stem cells (NSCs). Abnormal regulation of this process is associated with developmental and degenerative neuronal disorders. However, the mechanisms underlying the PCD of NSCs remain largely unknown. Understanding the mechanisms of PCD in NSCs is crucial for exploring therapeutic strategies for the treatment of neurodegenerative diseases. Result: We have previously reported that adult rat hippocampal neural stem (HCN) cells undergo autophagic cell death (ACD) following insulin withdrawal without apoptotic signs despite their normal apoptotic capabilities. It is unknown how interconnection between ACD and apoptosis is mediated in HCN cells. Valosin-containing protein (VCP) is known to be essential for autophagosome maturation in mammalian cells. VCP is abundantly expressed in HCN cells compared to hippocampal tissue and neurons. Pharmacological and genetic inhibition of VCP at basal state in the presence of insulin modestly impaired autophagic flux, consistent with its known role in autophagosome maturation. Of note, VCP inaction in insulin-deprived HCN cells significantly decreased ACD and down-regulated autophagy initiation signals with robust induction of apoptosis. Overall autophagy level was also substantially reduced, suggesting the novel roles of VCP at initial step of autophagy. Conclusion: Taken together, these data demonstrate that VCP may play an essential role in the initiation of autophagy and mediation of crosstalk between ACD and apoptosis in HCN cells when autophagy level is high upon insulin withdrawal. This is the first report on the role of VCP in regulation of NSC cell death. Elucidating the mechanism by which VCP regulates the crosstalk of ACD and apoptosis will contribute to understanding the molecular mechanism of PCD in NSCs. © 2016 Yeo et al.1

Significance of albumin to globulin ratio as a predictor of febrile urinary tract infection after ureteroscopic lithotripsy

Background We aimed to analyze the effectiveness of albumin to globulin ratio (AGR) in predicting postoperative febrile urinary tract infection (fUTI) after ureteroscopic lithotripsy (URS) and retrograde intrarenal surgery (RIRS). Methods From January 2013 to May 2018, 332 patients underwent URS and RIRS. The rate of postoperative fUTI and risk factors for postoperative fUTI were analyzed using logistic regression. Patients were divided into postoperative fUTI and non-postoperative fUTI (non-fUTI) groups. AGR with other demographic and perioperative data were compared between the two groups to predict the development of fUTI after URS. Results Of the 332 patients, postoperative fUTI occurred in 41 (12.3%). Preoperative pyuria, microscopic hematuria, diabetes mellitus, hypoalbuminemia, and hyperglobulinemia were more prevalent in the fUTI group. Patients in the fUTI group had larger stone size, lower preoperative AGR, longer operation time, and longer preoperative antibiotic coverage period. In a multivariable logistic analysis, preoperative pyuria, AGR, and stone size were independently correlated with postoperative fUTI (p<0.001, p=0.008, and p=0.041, respectively). Receiver operating curve analysis showed that the cutoff value of AGR that could predict a high risk of fUTI after URS was 1.437 (sensitivity, 77.3%; specificity, 76.9%), while the cutoff value of stone size was 8.5 mm (sensitivity, 55.3%; specificity, 44.7%). Conclusion This study demonstrated that preoperative pyuria, AGR, and stone size can serve as prognostic factors for predicting fUTI after URS

Manipulating magnetism in the topological semimetal EuCd2As2

EuCd2As2 is a magnetic semimetal that has the potential of manifesting nontrivial electronic states, depending on its low temperature magnetic ordering. Here, we report the successful synthesis of single crystals of EuCd2As2 that order ferromagnetically or antiferromagnetically depending on the level of band filling, thus allowing for the use of magnetism to tune the topological properties within the same host. We explored their physical properties via magnetization, electrical transport, heat capacity, and angle-resolved photoemission spectroscopy measurements and conclude that EuCd2As2 is an excellent, tunable system for exploring the interplay of magnetic ordering and topology

정중융기로 투사하는 소세포성 신경분비세포에서 발현되는 뇌 유래 인슐린의 뇌하수체 전엽 내 성장호르몬 생산 조절

insulin, hypothalamic paraventricular nucleus (PVN), median eminence (ME), parvocellular neurosecretory neuron, restraint stress (RS), pituitary, growth hormone (GH)췌장에서 생성되어 혈액으로 분비되는 인슐린은 포도당, 단백질 및 지질대사 조절에 중요한 역할을 하는 펩티드 호르몬이다. 혈장 인슐린 수치의 증가는 간의 포도당 생성 감소, 근육 내 포도당 흡수 효율 향상, 근육 내 단백질 분해 능력 저하 및 지방 조직 내 지질 분해 억제를 초래한다. 뿐만 아니라, 뇌에서 인슐린은 세포증식 및 분화, 신경보호, 신경조절, 기억 및 인지에도 영향을 미친다. 특히, 시상하부에서 인슐린은 특정 시상하부 신경세포들의 활성 조절을 촉발시킴으로써 음식 섭취, 체중 증가 및 에너지 소비를 음성적으로 조절하는 것으로도 잘 알려져 있다. 흥미롭게도, 인슐린이 췌장뿐만 아니라 시상하부를 포함한 다양한 뇌 영역들에서도 소량 합성될 수 있음을 보여주는 여러 연구 논문들이 1970년대부터 지금까지 꾸준히 발표되어 왔다. 그러나 이러한 뇌 유래 인슐린 (brain-derived insulin)이 시상하부를 구성하는 여러 신경핵들 중에서 정확히 어느 신경핵 내에서 만들어지는 지와, 여기서 국소적으로 만들어진 시상하부 인슐린이 어떠한 생리적인 기능을 가지는지는 여전히 의문으로 남아있었다. 본 연구는 쥐 시상하부에서 인슐린을 발현하는 신경세포체가 뇌실곁핵 (PVN) 내에 위치하며, 이 신경세포의 축삭이 정중융기 (ME)로 투사됨을 확인함으로써, 인슐린을 만들어내는 새로운 소세포성 신경분비세포 (parvocellular neurosecretory neuron)를 정의하였다. 뇌실곁핵 인슐린 신경세포 (PVN insulin neuron)의 약 85 %가 코르티코트로핀 분비 호르몬 (CRH)을 공동 발현하고, 이 코르티코트로핀 분비 호르몬을 인슐린과 함께 정중융기로 운반하였다. 코르티코트로핀 분비 호르몬 발현과 대조적으로, 뇌실곁핵에서의 인슐린 발현은 급성 구속 스트레스 (acute RS)에 의해 억제되었다. 이러한 급성 구속 스트레스에 의한 뇌실곁핵 내 인슐린의 발현 억제는 뇌하수체 성장호르몬 (Gh) mRNA 수준과 혈청 성장호르몬 농도를 모두 감소시켰으며, 이는 뇌실곁핵 인슐린의 과발현에 의해 약화되었다. 유사하게, 뇌실곁핵에 인슐린의 발현을 억제시키는 바이러스를 주입하자 뇌하수체 성장호르몬의 유전자 발현 및 분비가 하향 조절 되었다. 이번 연구 결과는 정상 조건과 스트레스 조건 모두에서, 뇌실곁핵의 소세포성 신경분비세포에서 합성 되는 인슐린이 뇌하수체 성장호르몬 생산 조절에 중요한 역할을 하고 있음을 시사한다. 따라서 이 논문은 뇌 유래 인슐린의 새로운 생리적인 기능을 밝혀내며, 시상하부–뇌하수체 조절에서 시상하부 인슐린, 특히 뇌실곁핵 인슐린의 역할을 더 잘 이해할 수 있도록 도와준다. |Insulin, produced by pancreatic β-cells and secreted into the bloodstream, is an influential and instrumental anabolic hormone that controls glucose, protein, and lipid metabolism. The increment of plasma insulin levels results in increased inhibition of hepatic glucose production, enhanced efficiency of glucose uptake in the muscle, decreased the capacity of protein degradation in the muscle, and reduced rate of lipolysis in the adipose tissue. Furthermore, in the brain, insulin has effect on cell proliferation and differentiation, neuroprotection, neuromodulation, memory, and cognition. In particular, insulin triggers the modulation of certain hypothalamic neuronal activity, negatively controlling food intake, weight gain, and energy expenditure. Although pancreatic β-cells are considered the major source of insulin in the brain, the evidence has mounted that small amounts of insulin can also be synthesized locally in various brain regions such as the choroid plexus, cerebellum, cerebral cortex, striatum, olfactory bulb, hippocampus, and hypothalamus. Recent studies have revealed regulatory mechanisms underlying insulin gene expression in the hypothalamus. However, the precise hypothalamic sub-regions that are involved in insulin production and the physiological roles of locally produced insulin in the hypothalamus still remain elusive. Herein, I show that in the mouse hypothalamus, the perikarya of insulin-positive neurons are located in the paraventricular nucleus (PVN) and their axons project to the external zone of the median eminence (ME)these findings define novel parvocellular neurosecretory PVN insulin neurons. 85% of PVN insulin neurons co-expressed corticotrophin-releasing hormone (CRH) and transported CRH along with insulin to the ME. Contrary to CRH expression, insulin expression in the PVN was inhibited by acute restraint stress (RS). The acute RS-induced inhibition of PVN insulin expression decreased both pituitary growth hormone (Gh) mRNA level and serum GH concentration, which were attenuated by overexpression of PVN insulin. Similarly, knockdown of PVN insulin down-regulated pituitary GH gene expression and secretion. These results suggest that in both normal and stressful conditions, insulin synthesized in parvocellular neurosecretory neurons of the PVN plays an important role in the regulation of pituitary GH production. Thus, this thesis unveils a new physiological function of brain-derived insulin, and helps a better understanding of the role of hypothalamic insulin, especially PVN insulin in hypothalamic–pituitary regulation.YAbstract i List of Contents iii List of Tables vi List of Figures vii List of abbreviations ix Ⅰ. Introduction 1 1. Insulin 1 1.1 Biosynthesis & Processing 1 1.2 Functions 3 1.3 Local synthesis in the brain 3 2. Hypothalamic paraventricular nucleus (PVN) 5 2.1 Anatomy & Functions 5 2.2 Parvocellular neurosecretory neuron 6 3. Hypothalamic median eminence (ME) 6 4. Anterior pituitary 8 5. Hypothalamic-pituitary regulation 8 5.1 Stress response: hypothalamic-pituitary-adrenal (HPA) axis 8 5.2 Growth & Development: hypothalamic-pituitary-somatotropic (HPS) axis 9 6. Aims of the study 10 Ⅱ. Materials & Method 11 1. Animals 11 2. Injection (i.p.) of Fluorogold (FG) 11 3. Injection of GFP-expressing lentivirus into the PVN 12 4. Injection (i.c.v.) of colchicine 12 5. Food deprivation 13 6. Restraint stress (RS) 13 7. Immunofluorescence staining 13 8. In situ hybridization 15 9. Electron microscopic immunohistochemistry 16 10. Preparation of lentiviral shRNAs and Ins2-overexpressing lentivirus 18 11. Administration of lentiviral shRNAs and Ins2-overexpressing lentivirus in to the PVN 18 12. Micro-dissection of PVN for RNA extraction 19 13. RNA extraction and gene expression analysis by qRT-PCR 19 14. Serum GH, corticosterone, and insulin analysis 21 15. Immunoblot analysis 21 16. Experimental design 22 17. Statistics 23 18. Study approval 23 Ⅲ. Results 24 1. The hippocampus and cerebral cortex express insulin. 24 2. Hypothalamic insulin is synthesized mainly in the PVN neurons. 24 3. C-peptide, a proxy for processed insulin, is located specifically in the ME neurosecretory nerve terminals within the hypothalamus. 32 4. PVN insulin neurons send their nerve terminals to the external zone of the ME. 35 5. A subset of PVN insulin neurons co-expresses CRH or SST. 41 6. PVN neurons expressing both insulin and CRH co-transport these proteins into the ME. 41 7. Acute RS inhibits PVN insulin expression. 45 8. PVN insulin supports pituitary GH production. 48 9. Acute RS–induced suppression of PVN insulin expression attenuates pituitary GH production. 49 Ⅳ. Discussion 55 Ⅴ. Conclusion 61 Ⅵ. References 63 Abstract in Korean 72DoctordCollectio

Optimal Color Lighting for Scanning Images of Flat Panel Display using Simplex Search

A system for inspecting flat panel displays (FPDs) acquires scanning images using multiline charge-coupled device (CCD) cameras and industrial machine vision. Optical filters are currently installed in front of these inspection systems to obtain high-quality images. However, the combination of optical filters required is determined manually and by using empirical methods; this is referred to as passive color control. In this study, active color control is proposed for inspecting FPDs. This inspection scheme requires the scanning of images, which is achieved using a mixed color light source and a mixing algorithm. The light source utilizes high-power light emitting diodes (LEDs) of multiple colors and a communication port to dim their level. Mixed light illuminates an active-matrix organic light-emitting diode (AMOLED) panel after passing through a beam expander and after being shaped into a line beam. The image quality is then evaluated using the Tenenbaum gradient after intensity calibration of the scanning images. The dimming levels are determined using the simplex search method which maximizes the image quality. The color of the light was varied after every scan of an AMOLED panel, and the variation was iterated until the image quality approached a local maximization. The number of scans performed was less than 225, while the number of dimming level combinations was 20484. The proposed method can reduce manual tasks in setting-up inspection machines, and hence is useful for the inspection machines in FPD processes

Generating Selected Color using RGB, Auxiliary Lights, and Simplex Search

A mixed light source generates various colors, with the potential to adjust intensities of multiple LEDs, which makes it possible to generate arbitrary colors. Currently, PCs and OSs provide color selection windows that can obtain the RGB or HSL color coordinates of a user’s selection. Mixed light sources are usually composed of LEDs in the primary colors, with LEDs in auxiliary colors such as white and yellow used in a few cases. When using auxiliary color LEDs, the number of LED inputs, the dimming levels, is larger than the number of elements in the color coordinate, which causes an under-determined problem. This study proposed how to determine the dimming levels of LEDs based on the selected color. Commercial LEDs have di_erent optical power values and impure color coordinates, even if they are RGB. Hence, the characteristics of the LEDs were described using a linear model derived from the tri-stimulus values (an XYZ color coordinate model) and dimming levels. Color mixing models were derived for the arbitrary number of auxiliary color LEDs. The under-determined problem was solved using a simplex search method without an inverse matrix operation. The proposed method can be applied to a machine vision system and an RGBW light mixer for semiconductor inspection. The dimming levels, obtained using the proposed method were better than derived using other methods