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  1. Article: RNA-Binding Protein Motifs Predict microRNA Secretion and Cellular Retention in Hypothalamic and Other Cell Types.

    He, Wenyuan / Belsham, Denise D

    Biomedicines

    2024  Volume 12, Issue 4

    Abstract: Cellular microRNAs (miRNAs) can be selectively secreted or retained, adding another layer to their critical role in regulating human health and disease. To date, select RNA-binding proteins (RBPs) have been proposed to be a mechanism underlying miRNA ... ...

    Abstract Cellular microRNAs (miRNAs) can be selectively secreted or retained, adding another layer to their critical role in regulating human health and disease. To date, select RNA-binding proteins (RBPs) have been proposed to be a mechanism underlying miRNA localization, but the overall relevance of RBPs in systematic miRNA sorting remains unclear. This study profiles intracellular and small extracellular vesicles' (sEVs) miRNAs in NPY-expressing hypothalamic neurons. These findings were corroborated by the publicly available sEV and intracellular miRNA profiles of white and brown adipocytes, endothelium, liver, and muscle from various databases. Using experimentally determined binding motifs of 93 RBPs, our enrichment analysis revealed that sEV-originating miRNAs contained significantly different RBP motifs than those of intracellularly retained miRNAs. Multiple RBP motifs were shared across cell types; for instance, RBM4 and SAMD4 are significantly enriched in neurons, hepatocytes, skeletal muscle, and endothelial cells. Homologs of both proteins physically interact with Argonaute1/2 proteins, suggesting that they play a role in miRNA sorting. Machine learning modelling also demonstrates that significantly enriched RBP motifs could predict cell-specific preferential miRNA sorting. Non-optimized machine learning modeling of the motifs using Random Forest and Naive Bayes in all cell types except WAT achieved an area under the receiver operating characteristic (ROC) curve of 0.77-0.84, indicating a high predictive accuracy. Given that the RBP motifs have a significant predictive power, these results underscore the critical role that RBPs play in miRNA sorting within mammalian cells and reinforce the importance of miRNA sequencing in preferential localization. For the future development of small RNA therapeutics, considering these RBP-RNA interactions could be crucial to maximize delivery effectiveness and minimize off-target effects.
    Language English
    Publishing date 2024-04-12
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2720867-9
    ISSN 2227-9059
    ISSN 2227-9059
    DOI 10.3390/biomedicines12040857
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: The Involvement of the microRNAs miR-466c and miR-340 in the Palmitate-Mediated Dysregulation of Gonadotropin-Releasing Hormone Gene Expression.

    Nkechika, Vanessa / Zhang, Ningtong / Belsham, Denise D

    Genes

    2024  Volume 15, Issue 4

    Abstract: Diets high in saturated fatty acids are associated with obesity and infertility. Palmitate, the most prevalent circulating saturated fatty acid, is sensed by hypothalamic neurons, contributing to homeostatic dysregulation. Notably, palmitate elevates the ...

    Abstract Diets high in saturated fatty acids are associated with obesity and infertility. Palmitate, the most prevalent circulating saturated fatty acid, is sensed by hypothalamic neurons, contributing to homeostatic dysregulation. Notably, palmitate elevates the mRNA levels of gonadotropin-releasing hormone (
    MeSH term(s) MicroRNAs/genetics ; Gonadotropin-Releasing Hormone/genetics ; Gonadotropin-Releasing Hormone/metabolism ; Animals ; Palmitates/metabolism ; Mice ; Gene Expression Regulation/drug effects ; GATA4 Transcription Factor/genetics ; GATA4 Transcription Factor/metabolism ; Neurons/metabolism ; Neurons/drug effects ; CCAAT-Enhancer-Binding Protein-beta/genetics ; CCAAT-Enhancer-Binding Protein-beta/metabolism ; Hypothalamus/metabolism
    Chemical Substances MicroRNAs ; Gonadotropin-Releasing Hormone (33515-09-2) ; Palmitates ; Mirn466 microRNA, mouse ; GATA4 Transcription Factor ; CCAAT-Enhancer-Binding Protein-beta ; Gata4 protein, mouse
    Language English
    Publishing date 2024-03-23
    Publishing country Switzerland
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2527218-4
    ISSN 2073-4425 ; 2073-4425
    ISSN (online) 2073-4425
    ISSN 2073-4425
    DOI 10.3390/genes15040397
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Npy transcription is regulated by noncanonical STAT3 signaling in hypothalamic neurons: Implication with lipotoxicity and obesity.

    He, Wenyuan / Loganathan, Neruja / Tran, Andy / Belsham, Denise D

    Molecular and cellular endocrinology

    2024  Volume 586, Page(s) 112179

    Abstract: Neuropeptide Y (Npy) is an abundant neuropeptide expressed in the central and peripheral nervous systems. NPY-secreting neurons in the hypothalamic arcuate nucleus regulate energy homeostasis, and Npy mRNA expression is regulated by peripheral nutrient ... ...

    Abstract Neuropeptide Y (Npy) is an abundant neuropeptide expressed in the central and peripheral nervous systems. NPY-secreting neurons in the hypothalamic arcuate nucleus regulate energy homeostasis, and Npy mRNA expression is regulated by peripheral nutrient and hormonal signals like leptin, interleukin-6 (IL-6), and fatty acids. This study demonstrates that IL-6, which phosphorylates tyrosine 705 (Y705) of STAT3, decreased Npy mRNA in arcuate immortalized hypothalamic neurons. In parallel, inhibitors of STAT3-Y705 phosphorylation, stattic and cucurbitacin I, robustly upregulated Npy mRNA. Chromatin-immunoprecipitation showed high baseline total STAT3 binding to multiple regulatory regions of the Npy gene, which are decreased by IL-6 exposure. The STAT3-Npy interaction was further examined in obesity-related pathologies. Notably, in four different hypothalamic neuronal models where palmitate potently stimulated Npy mRNA, Socs3, a specific STAT3 activity marker, was downregulated and was negatively correlated with Npy mRNA levels (R
    MeSH term(s) Humans ; Neuropeptide Y/genetics ; Neuropeptide Y/metabolism ; Leptin/pharmacology ; Leptin/metabolism ; Interleukin-6/genetics ; Interleukin-6/metabolism ; Hypothalamus/metabolism ; Obesity/metabolism ; Arcuate Nucleus of Hypothalamus/metabolism ; Neurons/metabolism ; RNA, Messenger/genetics ; STAT3 Transcription Factor/metabolism
    Chemical Substances Neuropeptide Y ; Leptin ; Interleukin-6 ; RNA, Messenger ; STAT3 protein, human ; STAT3 Transcription Factor
    Language English
    Publishing date 2024-02-20
    Publishing country Ireland
    Document type Journal Article
    ZDB-ID 187438-x
    ISSN 1872-8057 ; 0303-7207
    ISSN (online) 1872-8057
    ISSN 0303-7207
    DOI 10.1016/j.mce.2024.112179
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Promise and Perils of MicroRNA Discovery Research: Working Toward Quality Over Quantity.

    McIlwraith, Emma K / He, Wenyuan / Belsham, Denise D

    Endocrinology

    2023  Volume 164, Issue 9

    Abstract: Since the first microRNA (miRNA) was described in 1993 in the humble worm Caenorhabditis elegans, the miRNA field has boomed, with more than 100 000 related patents filed and miRNAs now in ongoing clinical trials. Despite an advanced understanding of the ...

    Abstract Since the first microRNA (miRNA) was described in 1993 in the humble worm Caenorhabditis elegans, the miRNA field has boomed, with more than 100 000 related patents filed and miRNAs now in ongoing clinical trials. Despite an advanced understanding of the biogenesis and action of miRNAs, applied miRNA research faces challenges and irreproducibility due to a lack of standardization. This review provides guidelines regarding miRNA investigation, while focusing on the pitfalls and considerations that are often overlooked in prevailing applied miRNA research. These include miRNA annotation and quantification, to modulation, target prediction, validation, and the study of circulating miRNAs.
    MeSH term(s) Animals ; MicroRNAs/genetics ; Caenorhabditis elegans/genetics ; RNA, Messenger/genetics
    Chemical Substances MicroRNAs ; RNA, Messenger
    Language English
    Publishing date 2023-07-15
    Publishing country United States
    Document type Review ; Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 427856-2
    ISSN 1945-7170 ; 0013-7227
    ISSN (online) 1945-7170
    ISSN 0013-7227
    DOI 10.1210/endocr/bqad111
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Palmitate alters miRNA content of small extracellular vesicles secreted from NPY/AgRP-expressing hypothalamic neurons.

    McIlwraith, Emma K / Belsham, Denise D

    Brain research

    2023  Volume 1810, Page(s) 148367

    Abstract: Exosomes (sEVs) are extracellular vesicles involved in the pathogenesis of obesity. Notably, exosomal microRNAs (miRNAs) have emerged as crucial mediators of communication between cells and are involved in the development of obesity. One region of the ... ...

    Abstract Exosomes (sEVs) are extracellular vesicles involved in the pathogenesis of obesity. Notably, exosomal microRNAs (miRNAs) have emerged as crucial mediators of communication between cells and are involved in the development of obesity. One region of the brain known to be dysregulated in obesity is the hypothalamus. It coordinates whole-body energy homeostasis through stimulation and inhibition of the orexigenic neuropeptide (NPY)/agouti-related peptide (AgRP) neurons and anorexigenic proopiomelanocortin (POMC) neurons. A role for hypothalamic astrocytic exosomes in communication with POMC neurons was previously elucidated. Yet, it was unknown whether NPY/AgRP neurons secreted exosomes. We previously established that the saturated fat palmitate alters the intracellular levels of miRNAs and we now questioned whether palmitate would also alter the miRNA content of exosomal miRNAs. We found that the mHypoE-46 cell line secreted particles consistent with the size of exosomes and that palmitate altered levels of a spectrum of miRNAs associated with exosomes. The predicted KEGG pathways of the collective miRNA predicted targets included fatty acid metabolism and type II diabetes mellitus. Of note, one of these altered secreted miRNAs was miR-2137, which was also altered within the cells. We also found that while sEVs collected from the mHypoE-46 neurons increased Pomc mRNA in the mHypoA-POMC/GFP-2 cells after 48 h, the effect was absent with sEVs isolated following palmitate treatment, indicating another potential route by which palmitate promotes obesity. Hypothalamic neuronal exosomes may therefore play a role in the control of energy homeostasis that may be disrupted in obese conditions.
    MeSH term(s) Humans ; Agouti-Related Protein/metabolism ; Diabetes Mellitus, Type 2/metabolism ; Extracellular Vesicles/metabolism ; Hypothalamus/metabolism ; Neurons/metabolism ; Neuropeptide Y/metabolism ; Obesity/metabolism ; Palmitates/pharmacology ; Palmitates/metabolism ; Pro-Opiomelanocortin/metabolism
    Chemical Substances Agouti-Related Protein ; Neuropeptide Y ; Palmitates ; Pro-Opiomelanocortin (66796-54-1)
    Language English
    Publishing date 2023-04-11
    Publishing country Netherlands
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1200-2
    ISSN 1872-6240 ; 0006-8993
    ISSN (online) 1872-6240
    ISSN 0006-8993
    DOI 10.1016/j.brainres.2023.148367
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Palmitate alters miR-2137 and miR-503-5p to induce orexigenic Npy in hypothalamic neuronal cell models: Rescue by oleate and docosahexaenoic acid.

    McIlwraith, Emma K / Belsham, Denise D

    Journal of neuroendocrinology

    2023  Volume 35, Issue 5, Page(s) e13271

    Abstract: MicroRNAs (miRNAs) are short noncoding RNA implicated in the pathogenesis of obesity. One cause of obesity is excess exposure to the saturated fatty acid palmitate that can alter miRNA levels in the periphery. Palmitate also promotes obesity by acting on ...

    Abstract MicroRNAs (miRNAs) are short noncoding RNA implicated in the pathogenesis of obesity. One cause of obesity is excess exposure to the saturated fatty acid palmitate that can alter miRNA levels in the periphery. Palmitate also promotes obesity by acting on the hypothalamus, the central coordinator of energy homeostasis, to dysregulate hypothalamic feeding neuropeptides and induce ER stress and inflammatory signaling. We hypothesized that palmitate would alter hypothalamic miRNAs that control genes involved in energy homeostasis thereby contributing to the obesity-promoting effects of palmitate. We found that palmitate upregulated 20 miRNAs and downregulated six miRNAs in the orexigenic NPY/AgRP-expressing mHypoE-46 cell line. We focused on delineating the roles of miR-2137 and miR-503-5p, as they were strongly up- and downregulated by palmitate, respectively. Overexpression of miR-2137 increased Npy mRNA levels and downregulated Esr1 levels, while increasing C/ebpβ and Atf3 mRNA. Inhibiting miR-2137 had the opposite effect, except on Npy, which was unchanged. The most downregulated miRNA by palmitate, miR-503-5p, negatively regulated Npy mRNA levels. Exposure to the unsaturated fatty acids oleate or docosahexaenoic acid completely or partially blocked the effects of palmitate on miR-2137 and miR-503-5p as well as Npy, Agrp, Esr1, C/ebpβ and Atf3. MicroRNAs may therefore contribute to palmitate actions in dysregulating NPY/AgRP neurons. Effectively combating the deleterious effects of palmitate is crucial to help prevent or reduce the impact of obesity.
    MeSH term(s) Agouti-Related Protein ; Cyclic AMP Response Element-Binding Protein ; Docosahexaenoic Acids/pharmacology ; Hypothalamus ; MicroRNAs/genetics ; Neurons ; Obesity ; Oleic Acid/pharmacology ; Palmitates/pharmacology ; RNA, Messenger ; Animals ; Mice
    Chemical Substances Agouti-Related Protein ; Cyclic AMP Response Element-Binding Protein ; Docosahexaenoic Acids (25167-62-8) ; MicroRNAs ; Oleic Acid (2UMI9U37CP) ; Palmitates ; RNA, Messenger
    Language English
    Publishing date 2023-05-20
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1007517-3
    ISSN 1365-2826 ; 0953-8194
    ISSN (online) 1365-2826
    ISSN 0953-8194
    DOI 10.1111/jne.13271
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  7. Article ; Online: Immunofluorescence of GFAP and TNF-α in the Mouse Hypothalamus.

    Dalvi, Prasad S / Belsham, Denise D

    Bio-protocol

    2021  Volume 11, Issue 13, Page(s) e4078

    Abstract: Immunofluorescence is a reliable method for identifying specific proteins in neuronal and glial cell populations of the hypothalamus. Several immunofluorescence protocols are available to detect protein markers and neuropeptides in the hypothalamus; ... ...

    Abstract Immunofluorescence is a reliable method for identifying specific proteins in neuronal and glial cell populations of the hypothalamus. Several immunofluorescence protocols are available to detect protein markers and neuropeptides in the hypothalamus; however, published methods may vary in subtle details that can potentially impact the final outcome of the procedure. Here, we provide a detailed protocol suitable for thin cryostat sections, which has been successful for specific antibodies directed against key markers of hypothalamic neurons and glial cells. We include every detail concerning brain tissue collection, processing, sectioning, and labeling with optimal dilutions of antibodies with the aim of reducing non-specific background. Our background-optimized immunostaining protocol has been routinely used in the lab and allows efficient detection of specific neuropeptides, glial cells, and markers of inflammation and endoplasmic reticulum stress in the hypothalamus.
    Language English
    Publishing date 2021-07-05
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2833269-6
    ISSN 2331-8325 ; 2331-8325
    ISSN (online) 2331-8325
    ISSN 2331-8325
    DOI 10.21769/BioProtoc.4078
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  8. Article ; Online: Bisphenol A Alters the Levels of miRNAs That Directly and/or Indirectly Target Neuropeptide Y in Murine Hypothalamic Neurons.

    Mak, Kimberly W Y / He, Wenyuan / Loganathan, Neruja / Belsham, Denise D

    Genes

    2023  Volume 14, Issue 9

    Abstract: The hypothalamus is a vital regulator of energy homeostasis. Orexigenic neuropeptide Y (NPY) neurons within the hypothalamus can stimulate feeding and suppress energy expenditure, and dysregulation of these neurons may contribute to obesity. We ... ...

    Abstract The hypothalamus is a vital regulator of energy homeostasis. Orexigenic neuropeptide Y (NPY) neurons within the hypothalamus can stimulate feeding and suppress energy expenditure, and dysregulation of these neurons may contribute to obesity. We previously reported that bisphenol A (BPA), an endocrine disruptor with obesogenic properties, alters
    Language English
    Publishing date 2023-09-08
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2527218-4
    ISSN 2073-4425 ; 2073-4425
    ISSN (online) 2073-4425
    ISSN 2073-4425
    DOI 10.3390/genes14091773
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  9. Article ; Online: Immortal orexin cell transplants restore motor-arousal synchrony during cataplexy.

    Pintwala, Sara K / Fraigne, Jimmy J / Belsham, Denise D / Peever, John H

    Current biology : CB

    2023  Volume 33, Issue 8, Page(s) 1550–1564.e5

    Abstract: Waking behaviors such as sitting or standing require suitable levels of muscle tone. But it is unclear how arousal and motor circuits communicate with one another so that appropriate motor tone occurs during wakefulness. Cataplexy is a peculiar condition ...

    Abstract Waking behaviors such as sitting or standing require suitable levels of muscle tone. But it is unclear how arousal and motor circuits communicate with one another so that appropriate motor tone occurs during wakefulness. Cataplexy is a peculiar condition in which muscle tone is involuntarily lost during normal periods of wakefulness. Cataplexy therefore provides a unique opportunity for identifying the signaling mechanisms that synchronize motor and arousal behaviors. Cataplexy occurs when hypothalamic orexin neurons are lost in narcolepsy; however, it is unclear if motor-arousal decoupling in cataplexy is directly or indirectly caused by orexin cell loss. Here, we used genomic, proteomic, chemogenetic, electrophysiological, and behavioral assays to determine if grafting orexin cells into the brain of cataplectic (i.e., orexin
    MeSH term(s) Mice ; Animals ; Cataplexy/therapy ; Orexins/genetics ; Orexins/metabolism ; Proteomics ; Arousal/physiology ; Wakefulness/physiology ; Dorsal Raphe Nucleus ; Cell Transplantation
    Chemical Substances Orexins
    Language English
    Publishing date 2023-04-11
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1071731-6
    ISSN 1879-0445 ; 0960-9822
    ISSN (online) 1879-0445
    ISSN 0960-9822
    DOI 10.1016/j.cub.2023.03.077
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  10. Article ; Online: Phenylbutyric acid robustly increases Npy mRNA expression in hypothalamic neurons by increasing H3K9/14 acetylation at the Npy promoter.

    Krunic, Andre / Loganathan, Neruja / Nkechika, Vanessa / Belsham, Denise D

    Biochemical and biophysical research communications

    2023  Volume 658, Page(s) 18–26

    Abstract: Phenylbutyric acid (PBA) is a commonly used inhibitor of endoplasmic reticulum stress, as well as a histone deacetylase (HDAC) inhibitor, that increases hypothalamic expression of orexigenic neuropeptide Y (Npy). Elucidation of the dose-response ... ...

    Abstract Phenylbutyric acid (PBA) is a commonly used inhibitor of endoplasmic reticulum stress, as well as a histone deacetylase (HDAC) inhibitor, that increases hypothalamic expression of orexigenic neuropeptide Y (Npy). Elucidation of the dose-response relationship and mechanism of action of PBA may position this compound as a potential therapeutic for eating disorders where Npy is dysregulated, such as anorexia nervosa. The hypothalamic neuronal model mHypoE-41 was exposed to PBA (5 μM-5 mM) to assess the maximal Npy upregulation. Transcription factors and histone acetylation-related genes were assessed by qRT-PCR, as well as the involvement estrogen receptors (ER) using siRNA knockdown. Changes in global and Npy promoter-specific H3K9/14 acetylation were detected using western analysis and chromatin immunoprecipitation. Treatment with 5 mM PBA led to a 10-fold and 206-fold increase in Npy mRNA at 4 and 16 h, respectively, as well as increased NPY secretion. This induction was not observed with another orexigenic neuropeptide Agrp. PBA significantly increased the expression of Foxo1, Socs3 and Atf3 and the ERs Esr1 and Esr2 mRNA, but the PBA-mediated induction of Npy was not dependent on ERα or ERβ. PBA induced histone H3K9/14 acetylation at 3 distinct Npy promoter regions, suggesting increased Npy transcriptional activation due to a more open chromatin structure. We also report changes in Hdac mRNAs by PBA and the fatty acid palmitate, highlighting the importance of epigenetic regulation in Npy transcription. Overall, we conclude that PBA has strong orexigenic potential and can robustly and specifically induce Npy in hypothalamic neurons through a mechanism likely involving histone H3 acetylation.
    MeSH term(s) Neuropeptide Y/genetics ; Neuropeptide Y/metabolism ; Histones/metabolism ; Epigenesis, Genetic ; Acetylation ; Hypothalamus/metabolism ; Neurons/metabolism ; Promoter Regions, Genetic ; RNA, Messenger/genetics ; RNA, Messenger/metabolism
    Chemical Substances Neuropeptide Y ; Histones ; 4-phenylbutyric acid (7WY7YBI87E) ; RNA, Messenger
    Language English
    Publishing date 2023-03-24
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 205723-2
    ISSN 1090-2104 ; 0006-291X ; 0006-291X
    ISSN (online) 1090-2104 ; 0006-291X
    ISSN 0006-291X
    DOI 10.1016/j.bbrc.2023.03.031
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