1
|
Chu SC, Chen PN, Chen JR, Yu CH, Hsieh YS, Kuo DY. Role of hypothalamic leptin-LepRb signaling in NPY-CART-mediated appetite suppression in amphetamine-treated rats. Horm Behav 2018; 98:173-182. [PMID: 29307696 DOI: 10.1016/j.yhbeh.2017.12.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/22/2017] [Accepted: 12/29/2017] [Indexed: 12/15/2022]
Abstract
Leptin is an adipose tissue hormone which plays an important role in regulating energy homeostasis. Amphetamine (AMPH) is a drug of appetite suppressant, which exerts its effect by decreasing the expression of hypothalamic neuropeptide Y (NPY) and increasing that of cocaine- and amphetamine-regulated transcript (CART). This study investigated whether leptin, the leptin receptor (LepRb) and the signal transducer and activator of transcription-3 (STAT3) were involved in NPY/CART-mediated appetite suppression in AMPH-treated rats. Rats were given AMPH daily for four days, and changes in the levels of blood leptin and hypothalamic NPY, CART, LepRb, Janus kinases 2 (JAK2), and STAT3 were assessed and compared. During the AMPH treatment, blood leptin levels and hypothalamic NPY expression decreased, with the largest reduction observed on Day 2. By contrast, the expression of hypothalamic CART, LepRb, JAK2, and STAT3 increased, with the maximum response on Day 2. Furthermore, the binding activity of pSTAT3/DNA increased and was expressed in similar pattern to that of CART, LepRb, and JAK2. An intracerebroventricular infusion of NPY antisense 60min prior to AMPH treatment increased the levels of leptin, as well as the expression in LepRb, JAK2, and CART, whereas an infusion of STAT3 antisense decreased these levels and the expression of these parameters. The results suggest that blood leptin and hypothalamic LepRb-JAK2-STAT3 signaling involved in NPY-CART-regulated appetite suppression in AMPH-treated rats. The findings may aid understanding the role of leptin-LepRb during the treatment of anorectic drugs.
Collapse
Affiliation(s)
- Shu-Chen Chu
- Department of Food Science, Central Taiwan University of Science and Technology, Taichung City 406, Taiwan
| | - Pei-Ni Chen
- Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Chung Shan Medical University Hospital, Taichung City 40201, Taiwan
| | - Jeng-Rung Chen
- Department of Veterinary Medicine, National Chung Hsing University, Taichung City 40201, Taiwan
| | - Ching-Han Yu
- Department of Physiology, Chung Shan Medical University, Chung Shan Medical University Hospital, Taichung City 40201, Taiwan
| | - Yih-Shou Hsieh
- Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Chung Shan Medical University Hospital, Taichung City 40201, Taiwan
| | - Dong-Yih Kuo
- Department of Physiology, Chung Shan Medical University, Chung Shan Medical University Hospital, Taichung City 40201, Taiwan.
| |
Collapse
|
2
|
Moravcová S, Červená K, Pačesová D, Bendová Z. Identification of STAT3 and STAT5 proteins in the rat suprachiasmatic nucleus and the Day/Night difference in astrocytic STAT3 phosphorylation in response to lipopolysaccharide. J Neurosci Res 2015; 94:99-108. [PMID: 26420542 DOI: 10.1002/jnr.23673] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/01/2015] [Accepted: 09/08/2015] [Indexed: 12/12/2022]
Abstract
Signal transducers and activators of transcription (STAT) proteins regulate many aspects of cellular physiology from growth and differentiations to immune responses. Using immunohistochemistry, we show the daily rhythm of STAT3 protein in the rat suprachiasmatic nucleus (SCN), with low but significant amplitude peaking in the morning. We also reveal the strong expression of STAT5A in astrocytes of the SCN and the STAT5B signal in nonastrocytic cells. Administration of lipopolysaccharide (LPS) acutely induced phosphorylation of STAT3 on Tyr705 during both the day and the night and induced phosphorylation on Ser727 but only after the daytime application. The LPS-induced phospho-STAT3 (Tyr705) remained elevated for 24 hr after the daytime application but declined within 8 hr when LPS was applied at night.
Collapse
Affiliation(s)
- Simona Moravcová
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Kateřina Červená
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Dominika Pačesová
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Zdeňka Bendová
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| |
Collapse
|
3
|
Chu SC, Chen PN, Hsieh YS, Yu CH, Lin MH, Lin YH, Kuo DY. Involvement of hypothalamic PI3K-STAT3 signalling in regulating appetite suppression mediated by amphetamine. Br J Pharmacol 2015; 171:3223-33. [PMID: 24597972 DOI: 10.1111/bph.12667] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 02/20/2014] [Accepted: 02/26/2014] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Appetite suppression induced by amphetamine has been attributed to its inhibition of neuropeptide Y (NPY) neurons and activation of pro-opiomelanocortin (POMC) neurons in the hypothalamus. This study examined whether STAT3 was involved in these actions of amphetamine. EXPERIMENTAL APPROACH Rats were given amphetamine daily for 4 days. Changes in the expression of NPY, POMC, melanocortin MC3 receptors, PI3K and STAT3 in the hypothalamus were assessed by RT-PCR and Western blotting. Antisense oligonucleotides to STAT3 were also used. KEY RESULTS Expression of NPY decreased with a maximum effect day 2 of amphetamine treatment. Expression of POMC, MC3 receptors, PI3K and STAT3 increased with a maximum response on day 2. Moreover, phosphorylation of STAT3 and its DNA binding activity increased and was expressed in a similar pattern. Infusion (i.c.v.) of STAT3 antisense at 60 min before amphetamine treatment, partly blocked amphetamine-induced anorexia and modulated expression of NPY, POMC, MC3 receptors and PI3K, indicating the involvement of STAT3 in amphetamine-treated rats. CONCLUSIONS AND IMPLICATIONS Hypothalamic PI3K-STAT3 signalling participated in the regulation of NPY- and POMC-mediated appetite suppression. These findings may contribute to a better understanding of anorectic drugs.
Collapse
Affiliation(s)
- Shu-Chen Chu
- Department of Food Science, Central Taiwan University of Science and Technology, Taichung City, Taiwan
| | | | | | | | | | | | | |
Collapse
|
4
|
Xu J, Nash RJ, Frey TK. Cellular responses to Sindbis virus infection of neural progenitors derived from human embryonic stem cells. BMC Res Notes 2014; 7:757. [PMID: 25343994 PMCID: PMC4307679 DOI: 10.1186/1756-0500-7-757] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 10/10/2014] [Indexed: 11/12/2022] Open
Abstract
Background Sindbis virus (SINV) causes age-dependent encephalitis in mice, and therefore serves as a model to study viral encephalitis. SINV is used as a vector for the delivery of genes into selected neural stem cell lines; however, the toxicity and side effects of this vector have rarely been discussed. In this context, we investigated the cellular responses of human embryonic stem cell (hESCs) derived neural progenitors (hNPCs) to SINV infection by assessing susceptibility of the cells to SINV infection, analyzing the effect of infection on cell proliferation and cell death, and examining the impact of SINV infection on hNPCs markers of stemness. Findings We found that hNPCs are highly susceptible to SINV infection. Upon infection, the viruses induced apoptosis to hNPCs while not affecting the expression of cell proliferation markers. Lastly, SINV infections result in significant changes in the expression of key regulators of hNPCs’ plasticity and homeostasis. Conclusion The robust and versatile signaling, proliferation, and other cell responses of hESCs-derived hNPCs to virus infection demonstrated that it is a good model to study the pathogenesis of viral-induced neurodevelopmental and degenerative diseases. On the other hand, the toxicity of SINV to hNPCs cells cannot be ignored, and therefore extra care should be taken when using SINV as a vector to deliver genes into human stem cell lines.
Collapse
Affiliation(s)
| | | | - Teryl K Frey
- Department of Biology, Georgia State University, Atlanta, GA, USA.
| |
Collapse
|
5
|
Targeting oxidative stress in the hypothalamus: the effect of transcription factor STAT3 knockdown on endogenous antioxidants-mediated appetite control. Arch Toxicol 2014; 89:87-100. [DOI: 10.1007/s00204-014-1252-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 04/15/2014] [Indexed: 12/18/2022]
|
6
|
Gaber ZB, Butler SJ, Novitch BG. PLZF regulates fibroblast growth factor responsiveness and maintenance of neural progenitors. PLoS Biol 2013; 11:e1001676. [PMID: 24115909 PMCID: PMC3792860 DOI: 10.1371/journal.pbio.1001676] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Accepted: 08/29/2013] [Indexed: 12/31/2022] Open
Abstract
A transcription factor called Promyelocytic Leukemia Zinc Finger (PLZF) calibrates the balance between spinal cord progenitor maintenance and differentiation by enhancing their sensitivity to mitogens that are present in developing embryos. Distinct classes of neurons and glial cells in the developing spinal cord arise at specific times and in specific quantities from spatially discrete neural progenitor domains. Thus, adjacent domains can exhibit marked differences in their proliferative potential and timing of differentiation. However, remarkably little is known about the mechanisms that account for this regional control. Here, we show that the transcription factor Promyelocytic Leukemia Zinc Finger (PLZF) plays a critical role shaping patterns of neuronal differentiation by gating the expression of Fibroblast Growth Factor (FGF) Receptor 3 and responsiveness of progenitors to FGFs. PLZF elevation increases FGFR3 expression and STAT3 pathway activity, suppresses neurogenesis, and biases progenitors towards glial cell production. In contrast, PLZF loss reduces FGFR3 levels, leading to premature neuronal differentiation. Together, these findings reveal a novel transcriptional strategy for spatially tuning the responsiveness of distinct neural progenitor groups to broadly distributed mitogenic signals in the embryonic environment. The embryonic spinal cord is organized into an array of discrete neural progenitor domains along the dorsoventral axis. Most of these domains undergo two periods of differentiation, first producing specific classes of neurons and then generating distinct populations of glial cells at later times. In addition, each of these progenitors pools exhibit marked differences in their proliferative capacities and propensity to differentiate to produce the appropriate numbers and diversity of neurons and glia needed to form functional neural circuits. The mechanisms behind this regional control of neural progenitor behavior, however, remain unclear. In this study, we identify the transcription factor Promyelocytic Leukemia Zinc Finger (PLZF) as a critical regulator of this process in the chick spinal cord. We show that PLZF is initially expressed by all spinal cord progenitors and then becomes restricted to a central domain, where it helps to limit the rate of neuronal differentiation and to preserve the progenitor pool for subsequent glial production. We also demonstrate that PLZF acts by promoting the expression of Fibroblast Growth Factor (FGF) Receptor 3, thereby enhancing the proliferative response of neural progenitors to FGFs present in developing embryos. Together, these findings reveal a novel developmental strategy for spatially controlling neural progenitor behavior by tuning their responsiveness to broadly distributed growth-promoting signals in the embryonic environment.
Collapse
Affiliation(s)
- Zachary B. Gaber
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
- Broad Center for Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
- Molecular Biology Interdepartmental Graduate Program, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
| | - Samantha J. Butler
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
- Broad Center for Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Bennett G. Novitch
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
- Broad Center for Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
- Molecular Biology Interdepartmental Graduate Program, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
- * E-mail:
| |
Collapse
|
7
|
Gallicano GI. Modeling to optimize terminal stem cell differentiation. SCIENTIFICA 2013; 2013:574354. [PMID: 24278782 PMCID: PMC3820305 DOI: 10.1155/2013/574354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 12/18/2012] [Indexed: 06/02/2023]
Abstract
Embryonic stem cell (ESC), iPCs, and adult stem cells (ASCs) all are among the most promising potential treatments for heart failure, spinal cord injury, neurodegenerative diseases, and diabetes. However, considerable uncertainty in the production of ESC-derived terminally differentiated cell types has limited the efficiency of their development. To address this uncertainty, we and other investigators have begun to employ a comprehensive statistical model of ESC differentiation for determining the role of intracellular pathways (e.g., STAT3) in ESC differentiation and determination of germ layer fate. The approach discussed here applies the Baysian statistical model to cell/developmental biology combining traditional flow cytometry methodology and specific morphological observations with advanced statistical and probabilistic modeling and experimental design. The final result of this study is a unique tool and model that enhances the understanding of how and when specific cell fates are determined during differentiation. This model provides a guideline for increasing the production efficiency of therapeutically viable ESCs/iPSCs/ASC derived neurons or any other cell type and will eventually lead to advances in stem cell therapy.
Collapse
Affiliation(s)
- G. Ian Gallicano
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University Medical Center, Washington, DC 20057, USA
| |
Collapse
|
8
|
Hyndman BD, Gujral TS, Krieger JR, Cockburn JG, Mulligan LM. Multiple functional effects of RET kinase domain sequence variants in Hirschsprung disease. Hum Mutat 2012; 34:132-42. [PMID: 22837065 DOI: 10.1002/humu.22170] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 07/16/2012] [Indexed: 01/08/2023]
Abstract
The REarranged during Transfection (RET) gene encodes a receptor tyrosine kinase required for maturation of the enteric nervous system. RET sequence variants occur in the congenital abnormality Hirschsprung disease (HSCR), characterized by absence of ganglia in the intestinal tract. Although HSCR-RET variants are predicted to inactivate RET, the molecular mechanisms of these events are not well characterized. Using structure-based models of RET, we predicted the molecular consequences of 23 HSCR-associated missense variants and how they lead to receptor dysfunction. We validated our predictions in biochemical and cell-based assays to explore mutational effects on RET protein functions. We found a minority of HSCR-RET variants abrogated RET kinase function, while the remaining mutants were phosphorylated and transduced intracellular signals. HSCR-RET sequence variants also impacted on maturation, stability, and degradation of RET proteins. We showed that each variant conferred a unique combination of effects that together impaired RET protein activity. However, all tested variants impaired RET-mediated cellular functions, including cell transformation and migration. Our data indicate that the molecular mechanisms of impaired RET function in HSCR are highly variable. Although a subset of variants cause loss of RET kinase activity and downstream signaling, enzymatic inactivation is not the sole mechanism at play in HSCR.
Collapse
Affiliation(s)
- Brandy D Hyndman
- Division of Cancer Biology and Genetics, Cancer Research Institute, and Department of Pathology and Molecular Medicine, Queen's University, Kingston, ON, Canada
| | | | | | | | | |
Collapse
|