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  1. Article ; Online: Transcriptional characterization of iPSC-derived microglia as a model for therapeutic development in neurodegeneration.

    Ramaswami, Gokul / Yuva-Aydemir, Yeliz / Akerberg, Brynn / Matthews, Bryan / Williams, Jenna / Golczer, Gabriel / Huang, Jiaqi / Al Abdullatif, Ali / Huh, Dann / Burkly, Linda C / Engle, Sandra J / Grossman, Iris / Sehgal, Alfica / Sigova, Alla A / Fremeau, Robert T / Liu, Yuting / Bumcrot, David

    Scientific reports

    2024  Volume 14, Issue 1, Page(s) 2153

    Abstract: Microglia are the resident immune cells in the brain that play a key role in driving neuroinflammation, a hallmark of neurodegenerative disorders. Inducible microglia-like cells have been developed as an in vitro platform for molecular and therapeutic ... ...

    Abstract Microglia are the resident immune cells in the brain that play a key role in driving neuroinflammation, a hallmark of neurodegenerative disorders. Inducible microglia-like cells have been developed as an in vitro platform for molecular and therapeutic hypothesis generation and testing. However, there has been no systematic assessment of similarity of these cells to primary human microglia along with their responsiveness to external cues expected of primary cells in the brain. In this study, we performed transcriptional characterization of commercially available human inducible pluripotent stem cell (iPSC)-derived microglia-like (iMGL) cells by bulk and single cell RNA sequencing to assess their similarity with primary human microglia. To evaluate their stimulation responsiveness, iMGL cells were treated with Liver X Receptor (LXR) pathway agonists and their transcriptional responses characterized by bulk and single cell RNA sequencing. Bulk transcriptome analyses demonstrate that iMGL cells have a similar overall expression profile to freshly isolated human primary microglia and express many key microglial transcription factors and functional and disease-associated genes. Notably, at the single-cell level, iMGL cells exhibit distinct transcriptional subpopulations, representing both homeostatic and activated states present in normal and diseased primary microglia. Treatment of iMGL cells with LXR pathway agonists induces robust transcriptional changes in lipid metabolism and cell cycle at the bulk level. At the single cell level, we observe heterogeneity in responses between cell subpopulations in homeostatic and activated states and deconvolute bulk expression changes into their corresponding single cell states. In summary, our results demonstrate that iMGL cells exhibit a complex transcriptional profile and responsiveness, reminiscent of in vivo microglia, and thus represent a promising model system for therapeutic development in neurodegeneration.
    MeSH term(s) Humans ; Microglia/metabolism ; Induced Pluripotent Stem Cells ; Pluripotent Stem Cells ; Transcription Factors/metabolism ; Neurodegenerative Diseases/genetics ; Neurodegenerative Diseases/metabolism
    Chemical Substances Transcription Factors
    Language English
    Publishing date 2024-01-25
    Publishing country England
    Document type Journal Article
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-024-52311-0
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Author Correction: Transcriptional characterization of iPSC-derived microglia as a model for therapeutic development in neurodegeneration.

    Ramaswami, Gokul / Yuva-Aydemir, Yeliz / Akerberg, Brynn / Matthews, Bryan / Williams, Jenna / Golczer, Gabriel / Huang, Jiaqi / Al Abdullatif, Ali / Huh, Dann / Burkly, Linda C / Engle, Sandra J / Grossman, Iris / Sehgal, Alfica / Sigova, Alla A / Fremeau, Robert T / Liu, Yuting / Bumcrot, David

    Scientific reports

    2024  Volume 14, Issue 1, Page(s) 9346

    Language English
    Publishing date 2024-04-23
    Publishing country England
    Document type Published Erratum
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-024-60234-z
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Methods to Identify and Characterize siRNAs Targeting Serpin A1 In Vitro and In Vivo Using RNA Interference.

    Milstein, Stuart / Qian, Kun / Zhang, Linying / Sehgal, Alfica

    Methods in molecular biology (Clifton, N.J.)

    2017  Volume 1639, Page(s) 115–126

    Abstract: RNAi is a powerful tool that can be used to probe gene function as well as for therapeutic intervention. We describe a workflow and methods to identify screen and select potent and specific siRNAs in vitro and in vivo using qPCR-based methods as well as ... ...

    Abstract RNAi is a powerful tool that can be used to probe gene function as well as for therapeutic intervention. We describe a workflow and methods to identify screen and select potent and specific siRNAs in vitro and in vivo using qPCR-based methods as well as an AAT activity assay. We apply these techniques to a set of siRNAs targeting rat AAT, and use this set to exemplify the cell-based and in vivo data that can be generated using these methods.
    MeSH term(s) Animals ; Cell Line ; DNA, Complementary/genetics ; Female ; Gene Knockdown Techniques ; Humans ; Mice ; Molecular Biology/methods ; RNA Interference ; RNA, Small Interfering/metabolism ; Rats ; Reproducibility of Results ; Transfection ; alpha 1-Antitrypsin/genetics ; alpha 1-Antitrypsin/metabolism
    Chemical Substances DNA, Complementary ; RNA, Small Interfering ; alpha 1-Antitrypsin
    Language English
    Publishing date 2017-07-20
    Publishing country United States
    Document type Journal Article
    ISSN 1940-6029
    ISSN (online) 1940-6029
    DOI 10.1007/978-1-4939-7163-3_11
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Thrombin generation in plasma of patients with haemophilia A and B with inhibitors: Effects of bypassing agents and antithrombin reduction.

    Livnat, Tami / Sehgal, Alfica / Qian, Kun / Van Nguyen, Huy / Madigan, Kate / Sorensen, Benny / Kenet, Gili

    Blood cells, molecules & diseases

    2020  Volume 82, Page(s) 102416

    Abstract: Antithrombin (AT) reduction has been shown to improve thrombin generation (TG) in haemophilia with or without inhibitors. As treatment with bypassing agents (BPAs) may be required in patients with breakthrough bleeding while receiving AT-lowering therapy, ...

    Abstract Antithrombin (AT) reduction has been shown to improve thrombin generation (TG) in haemophilia with or without inhibitors. As treatment with bypassing agents (BPAs) may be required in patients with breakthrough bleeding while receiving AT-lowering therapy, we assessed TG in platelet-poor plasma samples from haemophilia patients in the presence of BPA (recombinant activated factor VII [rFVIIa; 1.25 or 2.5 μg mL
    MeSH term(s) Adolescent ; Adult ; Antithrombins/blood ; Blood Coagulation Factor Inhibitors/blood ; Child ; Child, Preschool ; Hemophilia A/blood ; Hemophilia B/blood ; Humans ; Infant ; Male ; Middle Aged ; Prospective Studies ; Thrombin/metabolism
    Chemical Substances Antithrombins ; Blood Coagulation Factor Inhibitors ; Thrombin (EC 3.4.21.5)
    Language English
    Publishing date 2020-02-11
    Publishing country United States
    Document type Clinical Trial ; Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1237083-6
    ISSN 1096-0961 ; 1079-9796
    ISSN (online) 1096-0961
    ISSN 1079-9796
    DOI 10.1016/j.bcmd.2020.102416
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Progesterone receptor membrane component 1 (PGRMC1) binds and stabilizes cytochromes P450 through a heme-independent mechanism.

    McGuire, Meredith R / Mukhopadhyay, Debaditya / Myers, Stephanie L / Mosher, Eric P / Brookheart, Rita T / Kammers, Kai / Sehgal, Alfica / Selen, Ebru S / Wolfgang, Michael J / Bumpus, Namandjé N / Espenshade, Peter J

    The Journal of biological chemistry

    2021  Volume 297, Issue 5, Page(s) 101316

    Abstract: Progesterone receptor membrane component 1 (PGRMC1) is a heme-binding protein implicated in a wide range of cellular functions. We previously showed that PGRMC1 binds to cytochromes P450 in yeast and mammalian cells and supports their activity. Recently, ...

    Abstract Progesterone receptor membrane component 1 (PGRMC1) is a heme-binding protein implicated in a wide range of cellular functions. We previously showed that PGRMC1 binds to cytochromes P450 in yeast and mammalian cells and supports their activity. Recently, the paralog PGRMC2 was shown to function as a heme chaperone. The extent of PGRMC1 function in cytochrome P450 biology and whether PGRMC1 is also a heme chaperone are unknown. Here, we examined the function of Pgrmc1 in mouse liver using a knockout model and found that Pgrmc1 binds and stabilizes a broad range of cytochromes P450 in a heme-independent manner. Proteomic and transcriptomic studies demonstrated that Pgrmc1 binds more than 13 cytochromes P450 and supports maintenance of cytochrome P450 protein levels posttranscriptionally. In vitro assays confirmed that Pgrmc1 KO livers exhibit reduced cytochrome P450 activity consistent with reduced enzyme levels. Mechanistic studies in cultured cells demonstrated that PGRMC1 stabilizes cytochromes P450 and that binding and stabilization do not require PGRMC1 binding to heme. Importantly, Pgrmc1-dependent stabilization of cytochromes P450 is physiologically relevant, as Pgrmc1 deletion protected mice from acetaminophen-induced liver injury. Finally, evaluation of Y113F mutant Pgrmc1, which lacks the axial heme iron-coordinating hydroxyl group, revealed that proper iron coordination is not required for heme binding, but is required for binding to ferrochelatase, the final enzyme in heme biosynthesis. PGRMC1 was recently identified as the causative mutation in X-linked isolated pediatric cataract formation. Together, these results demonstrate a heme-independent function for PGRMC1 in cytochrome P450 stability that may underlie clinical phenotypes.
    MeSH term(s) Amino Acid Substitution ; Animals ; Cytochrome P-450 Enzyme System/genetics ; Cytochrome P-450 Enzyme System/metabolism ; Enzyme Stability ; HeLa Cells ; Heme/genetics ; Heme/metabolism ; Humans ; Membrane Proteins/genetics ; Membrane Proteins/metabolism ; Mice ; Mice, Knockout ; Mutation, Missense ; Receptors, Progesterone/genetics ; Receptors, Progesterone/metabolism
    Chemical Substances Membrane Proteins ; PGRMC1 protein, human ; PGRMC1 protein, mouse ; Receptors, Progesterone ; Heme (42VZT0U6YR) ; Cytochrome P-450 Enzyme System (9035-51-2)
    Language English
    Publishing date 2021-10-20
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2997-x
    ISSN 1083-351X ; 0021-9258
    ISSN (online) 1083-351X
    ISSN 0021-9258
    DOI 10.1016/j.jbc.2021.101316
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Opportunities and challenges for innovative and equitable healthcare.

    Ecker, David J / Aiello, Clarice D / Arron, Joseph R / Bennett, C Frank / Bernard, Amy / Breakefield, Xandra O / Broderick, Timothy J / Callier, Shawneequa L / Canton, Barry / Chen, Janice S / Fishburn, C Simone / Garrett, Banning / Hecht, Sidney M / Janowitz, Tobias / Kliegman, Melinda / Krainer, Adrian / Louis, Chrystal U / Lowe, Christopher / Sehgal, Alfica /
    Tozan, Yesim / Tracey, Kevin J / Urnov, Fyodor / Wattendorf, Daniel / Williams, Thomas W / Zhao, Xuanhe / Hayden, Michael R

    Nature reviews. Drug discovery

    2024  Volume 23, Issue 5, Page(s) 321–322

    MeSH term(s) Humans ; Delivery of Health Care ; Health Equity ; Healthcare Disparities ; COVID-19/epidemiology
    Language English
    Publishing date 2024-02-26
    Publishing country England
    Document type Journal Article ; News
    ZDB-ID 2062954-0
    ISSN 1474-1784 ; 1474-1776
    ISSN (online) 1474-1784
    ISSN 1474-1776
    DOI 10.1038/d41573-024-00032-4
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Liver as a target for oligonucleotide therapeutics.

    Sehgal, Alfica / Vaishnaw, Akshay / Fitzgerald, Kevin

    Journal of hepatology

    2013  Volume 59, Issue 6, Page(s) 1354–1359

    Abstract: Oligonucleotide-based therapeutics are an emerging class of drugs that hold the promise for silencing "un-druggable" targets,thus creating unique opportunities for innovative medicines. As opposed to gene therapy, oligonucleotides are considered to be ... ...

    Abstract Oligonucleotide-based therapeutics are an emerging class of drugs that hold the promise for silencing "un-druggable" targets,thus creating unique opportunities for innovative medicines. As opposed to gene therapy, oligonucleotides are considered to be more akin to small molecule therapeutics because they are small,completely synthetic in origin, do not integrate into the host genome,and have a defined duration of therapeutic activity after which effects recover to baseline. They offer a high degree of specificity at the genetic level, thereby reducing off-target effects.At the same time, they provide a strategy for targeting any gene in the genome, including transcripts that produce mutated proteins.Oligonucleotide-based therapeutics include short interfering RNA (siRNA), that degrade target mRNA through RISC mediated RNAi; anti-miRs, that target miRNAs; miRNA mimics, that regulate target mRNA; antisense oligonucleotides, that may be working through RNAseH mediated mRNA decay; mRNA upregulation,by targeting long non-coding RNAs; and oligonucleotides induced alternative splicing [1]. All these approaches require some minimal degree of homology at the nucleic acid sequence level for them to be functional. The different mechanisms of action and their relevant activity are outlined in Fig. 1. Besides homology,RNA secondary structure has also been exploited in the case of ribozymes and aptamers, which act by binding to nucleic acids or proteins, respectively. While there have been many reports of gene knockdown and gene modulation in cell lines and mice with all these methods, very few have advanced to clinical stages.The main obstacle to date has been the safe and effective intracellular delivery of these compounds in higher species, including humans. Indeed, their action requires direct interaction with DNA/RNA within the target cell so even when one solves the issues of tissue and cellular access, intracellular/intranuclear location represents yet another barrier to overcome. To date,hepatic delivery of oligonucleotides has been the area with greatest progress, and thus we have focused on liver-targeted therapeutics that have shown promise at the preclinical and/or clinical level.The liver is the largest internal organ in the body, playing a central role in metabolism, detoxification, synthesis, and secretion of major plasma proteins (carrier proteins, coagulation factors,complement components, hormones, and apolipoproteins),and iron homeostasis. It is therefore not surprising that a large number of disease targets reside in the liver where they are susceptible to modulation by oligonucleotide therapies.
    MeSH term(s) Angiopoietin-like Proteins ; Angiopoietins/physiology ; Cholesterol, LDL/blood ; Humans ; Liver Diseases/drug therapy ; Oligonucleotides/therapeutic use ; Oligonucleotides, Antisense/therapeutic use
    Chemical Substances ANGPTL3 protein, human ; Angiopoietin-like Proteins ; Angiopoietins ; Cholesterol, LDL ; Oligonucleotides ; Oligonucleotides, Antisense
    Language English
    Publishing date 2013-12
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 605953-3
    ISSN 1600-0641 ; 0168-8278
    ISSN (online) 1600-0641
    ISSN 0168-8278
    DOI 10.1016/j.jhep.2013.05.045
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Discovery and Targeting of the Signaling Controls of

    Schwartz, Brian E / Rajagopal, Vaishnavi / Smith, Cynthia / Cohick, Evan / Whissell, Gavin / Gamboa, Mario / Pai, Rutuja / Sigova, Alla / Grossman, Iris / Bumcrot, David / Sasidharan, Kavitha / Romeo, Stefano / Sehgal, Alfica / Pingitore, Piero

    Cells

    2020  Volume 9, Issue 10

    Abstract: Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are emerging worldwide epidemics, projected to become the leading cause of liver transplants. The strongest genetic risk factor for NAFLD/NASH susceptibility and ... ...

    Abstract Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are emerging worldwide epidemics, projected to become the leading cause of liver transplants. The strongest genetic risk factor for NAFLD/NASH susceptibility and progression is a single-nucleotide polymorphism (SNP) in the patatin-like phospholipase domain-containing 3 gene (
    MeSH term(s) Animals ; Humans ; Male ; Mice ; Non-alcoholic Fatty Liver Disease/genetics ; Phospholipases A2, Calcium-Independent/metabolism ; Signal Transduction ; Transfection
    Chemical Substances PNPLA3 protein, mouse (EC 3.1.1.3) ; Phospholipases A2, Calcium-Independent (EC 3.1.1.4)
    Language English
    Publishing date 2020-10-07
    Publishing country Switzerland
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2661518-6
    ISSN 2073-4409 ; 2073-4409
    ISSN (online) 2073-4409
    ISSN 2073-4409
    DOI 10.3390/cells9102247
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article: Oxygen-dependent, alternative promoter controls translation of tco1⁺ in fission yeast

    Sehgal, Alfica / Hughes, Bridget T / Espenshade, Peter J

    Nucleic acids research. 2008 Apr., v. 36, no. 6

    2008  

    Abstract: Eukaryotic cells respond to changes in environmental oxygen supply by increasing transcription and subsequent translation of gene products required for adaptation to low oxygen. In fission yeast, the ortholog of mammalian sterol regulatory element ... ...

    Abstract Eukaryotic cells respond to changes in environmental oxygen supply by increasing transcription and subsequent translation of gene products required for adaptation to low oxygen. In fission yeast, the ortholog of mammalian sterol regulatory element binding protein (SREBP), called Sre1, activates low-oxygen gene expression and is essential for anaerobic growth. Previous studies in multiple organisms indicate that SREBP transcription factors function as positive regulators of gene expression by increasing transcription. Here, we describe a unique mechanism by which activation of Sre1-dependent transcription downregulates protein expression under low oxygen. Paradoxically, Sre1 inhibits expression of tco1⁺ gene product by activating its transcription. Under low oxygen, Sre1 directs transcription of tco1⁺ from an alternate, upstream promoter and inhibits expression of the normoxic tco1⁺ transcript. The resulting low-oxygen transcript contains an additional 751 nt in the 5' untranslated region that is predicted to form a stable, complex secondary structure. Interestingly, polysome profile experiments revealed that this new longer transcript is translationally silent, leading to a decrease in Tco1 protein expression under low oxygen. Together, these results describe a new mechanism for oxygen-dependent control of gene expression and provide an example of negative regulation of protein expression by an SREBP homolog.
    Keywords 5' untranslated regions ; Schizosaccharomyces pombe ; binding proteins ; eukaryotic cells ; gene expression ; gene expression regulation ; genes ; mammals ; oxygen ; protein synthesis ; sterols ; transcription (genetics) ; transcription factors ; translation (genetics)
    Language English
    Dates of publication 2008-04
    Size p. 2024-2031.
    Document type Article
    ZDB-ID 186809-3
    ISSN 0301-5610 ; 0305-1048
    ISSN 0301-5610 ; 0305-1048
    DOI 10.1093/nar/gkn027
    Database NAL-Catalogue (AGRICOLA)

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  10. Article ; Online: Oxygen-dependent, alternative promoter controls translation of tco1+ in fission yeast.

    Sehgal, Alfica / Hughes, Bridget T / Espenshade, Peter J

    Nucleic acids research

    2008  Volume 36, Issue 6, Page(s) 2024–2031

    Abstract: Eukaryotic cells respond to changes in environmental oxygen supply by increasing transcription and subsequent translation of gene products required for adaptation to low oxygen. In fission yeast, the ortholog of mammalian sterol regulatory element ... ...

    Abstract Eukaryotic cells respond to changes in environmental oxygen supply by increasing transcription and subsequent translation of gene products required for adaptation to low oxygen. In fission yeast, the ortholog of mammalian sterol regulatory element binding protein (SREBP), called Sre1, activates low-oxygen gene expression and is essential for anaerobic growth. Previous studies in multiple organisms indicate that SREBP transcription factors function as positive regulators of gene expression by increasing transcription. Here, we describe a unique mechanism by which activation of Sre1-dependent transcription downregulates protein expression under low oxygen. Paradoxically, Sre1 inhibits expression of tco1(+) gene product by activating its transcription. Under low oxygen, Sre1 directs transcription of tco1(+) from an alternate, upstream promoter and inhibits expression of the normoxic tco1(+) transcript. The resulting low-oxygen transcript contains an additional 751 nt in the 5' untranslated region that is predicted to form a stable, complex secondary structure. Interestingly, polysome profile experiments revealed that this new longer transcript is translationally silent, leading to a decrease in Tco1 protein expression under low oxygen. Together, these results describe a new mechanism for oxygen-dependent control of gene expression and provide an example of negative regulation of protein expression by an SREBP homolog.
    MeSH term(s) 5' Untranslated Regions/chemistry ; Gene Expression Regulation, Fungal ; Nucleic Acid Conformation ; Oxygen/metabolism ; Promoter Regions, Genetic ; Protein Biosynthesis ; Schizosaccharomyces/genetics ; Schizosaccharomyces/metabolism ; Schizosaccharomyces pombe Proteins/biosynthesis ; Schizosaccharomyces pombe Proteins/genetics ; Schizosaccharomyces pombe Proteins/metabolism ; Sterol Regulatory Element Binding Proteins/metabolism
    Chemical Substances 5' Untranslated Regions ; Schizosaccharomyces pombe Proteins ; Sre1 protein, S pombe ; Sterol Regulatory Element Binding Proteins ; Oxygen (S88TT14065)
    Language English
    Publishing date 2008-02-14
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 186809-3
    ISSN 1362-4962 ; 1362-4954 ; 0301-5610 ; 0305-1048
    ISSN (online) 1362-4962 ; 1362-4954
    ISSN 0301-5610 ; 0305-1048
    DOI 10.1093/nar/gkn027
    Database MEDical Literature Analysis and Retrieval System OnLINE

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