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  1. Article: Fah Knockout Animals as Models for Therapeutic Liver Repopulation.

    Grompe, Markus

    Advances in experimental medicine and biology

    2017  Volume 959, Page(s) 215–230

    Abstract: Several animal models of Fah deficiency have been developed, including mice, pigs and most recently rats. Initially, the murine models were developed with the intent to mirror the human disease for pathophysiologic and therapeutic studies. However, it ... ...

    Abstract Several animal models of Fah deficiency have been developed, including mice, pigs and most recently rats. Initially, the murine models were developed with the intent to mirror the human disease for pathophysiologic and therapeutic studies. However, it soon became apparent that Fah-positive hepatocytes have a potent selective growth advantage in mutant liver and can extensively repopulate the diseased organ. For this reason, Fah mutant mice have become a workhorse for liver biology and are widely used in liver stem cell and hepatic gene therapy research. Immune deficient Fah-knockout mice can be repopulated with human hepatocytes, creating "mice with human livers". These chimeric animals have become an important preclinical model for infectious diseases, metabolism and gene therapy. The potent expansion of human hepatocytes in Fah knockout mice has given rise to the concept of using Fah mutants as living bioreactors to produce large quantities of fully mature hepatocytes. As a consequence, larger animal models of Fah deficiency have recently been developed.
    Language English
    Publishing date 2017
    Publishing country United States
    Document type Journal Article
    ISSN 2214-8019 ; 0065-2598
    ISSN (online) 2214-8019
    ISSN 0065-2598
    DOI 10.1007/978-3-319-55780-9_20
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Liver stem cells, where art thou?

    Grompe, Markus

    Cell stem cell

    2014  Volume 15, Issue 3, Page(s) 257–258

    Abstract: Facultative liver stem cells have long been thought to be an important source of new hepatocytes during chronic liver injury. This longstanding paradigm is being challenged by two papers discussed herein (Schaub et al., 2014; Yanger et al., 2014). ...

    Abstract Facultative liver stem cells have long been thought to be an important source of new hepatocytes during chronic liver injury. This longstanding paradigm is being challenged by two papers discussed herein (Schaub et al., 2014; Yanger et al., 2014).
    Language English
    Publishing date 2014-09-04
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2375354-7
    ISSN 1875-9777 ; 1934-5909
    ISSN (online) 1875-9777
    ISSN 1934-5909
    DOI 10.1016/j.stem.2014.08.004
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Complete correction of murine phenylketonuria by selection-enhanced hepatocyte transplantation.

    Vonada, Anne / Wakefield, Leslie / Martinez, Michael / Harding, Cary O / Grompe, Markus / Tiyaboonchai, Amita

    bioRxiv : the preprint server for biology

    2023  

    Abstract: Hepatocyte transplantation for genetic liver diseases has several potential advantages over gene therapy. However, low efficiency of cell engraftment has limited its clinical implementation. This problem could be overcome by selectively expanding ... ...

    Abstract Hepatocyte transplantation for genetic liver diseases has several potential advantages over gene therapy. However, low efficiency of cell engraftment has limited its clinical implementation. This problem could be overcome by selectively expanding transplanted donor cells until they replace enough of the liver mass to achieve therapeutic benefit. We previously described a gene therapy method to selectively expand hepatocytes deficient in cytochrome p450 reductase (Cypor) using acetaminophen (APAP). Because Cypor is required for the transformation of APAP to a hepatotoxic metabolite, Cypor deficient cells are protected from toxicity and are able to expand following APAP-induced liver injury. Here, we apply this selection system to correct a mouse model of phenylketonuria (PKU) by cell transplantation. Hepatocytes from a wildtype donor animal were edited in vitro to create Cypor deficiency and then transplanted into PKU animals. Following selection with APAP, blood phenylalanine concentrations were fully normalized and remained stable following APAP withdrawal. Cypor-deficient hepatocytes expanded from <1% to ~14% in corrected animals, and they showed no abnormalities in blood chemistries, liver histology, or drug metabolism. We conclude that APAP-mediated selection of transplanted hepatocytes is a potential therapeutic for PKU with long-term efficacy and a favorable safety profile.
    Language English
    Publishing date 2023-08-28
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2023.08.27.554228
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Complete correction of murine phenylketonuria by selection-enhanced hepatocyte transplantation.

    Vonada, Anne / Wakefield, Leslie / Martinez, Michael / Harding, Cary O / Grompe, Markus / Tiyaboonchai, Amita

    Hepatology (Baltimore, Md.)

    2023  Volume 79, Issue 5, Page(s) 1088–1097

    Abstract: Background and aims: Hepatocyte transplantation for genetic liver diseases has several potential advantages over gene therapy. However, the low efficiency of cell engraftment has limited its clinical implementation. This problem could be overcome by ... ...

    Abstract Background and aims: Hepatocyte transplantation for genetic liver diseases has several potential advantages over gene therapy. However, the low efficiency of cell engraftment has limited its clinical implementation. This problem could be overcome by selectively expanding transplanted donor cells until they replace enough of the liver mass to achieve therapeutic benefit. We previously described a gene therapy method to selectively expand hepatocytes deficient in cytochrome p450 reductase (Cypor) using acetaminophen (APAP). Because Cypor is required for the transformation of APAP to a hepatotoxic metabolite, Cypor-deficient cells are protected from toxicity and are able to expand following APAP-induced liver injury. Here, we apply this selection system to correct a mouse model of phenylketonuria by cell transplantation.
    Approach and results: Hepatocytes from a wild-type donor animal were edited in vitro to create Cypor deficiency and then transplanted into phenylketonuric animals. Following selection with APAP, blood phenylalanine concentrations were fully normalized and remained stable following APAP withdrawal. Cypor-deficient hepatocytes expanded from < 1% to ~14% in corrected animals, and they showed no abnormalities in blood chemistries, liver histology, or drug metabolism.
    Conclusions: We conclude that APAP-mediated selection of transplanted hepatocytes is a potential therapeutic for phenylketonuria with long-term efficacy and a favorable safety profile.
    MeSH term(s) Mice ; Animals ; Acetaminophen ; Hepatocytes/metabolism ; Liver/pathology ; Phenylketonurias/metabolism ; Phenylketonurias/pathology ; Disease Models, Animal ; Chemical and Drug Induced Liver Injury/pathology ; Mice, Inbred C57BL
    Chemical Substances Acetaminophen (362O9ITL9D)
    Language English
    Publishing date 2023-10-12
    Publishing country United States
    Document type Journal Article
    ZDB-ID 604603-4
    ISSN 1527-3350 ; 0270-9139
    ISSN (online) 1527-3350
    ISSN 0270-9139
    DOI 10.1097/HEP.0000000000000631
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Tissue stem cells: new tools and functional diversity.

    Grompe, Markus

    Cell stem cell

    2012  Volume 10, Issue 6, Page(s) 685–689

    Abstract: The detailed understanding of adult tissue stem cells has significance for both regenerative medicine and oncology. This perspective will discuss how major advances in our ability to identify and monitor these cells, which include genetic lineage tracing, ...

    Abstract The detailed understanding of adult tissue stem cells has significance for both regenerative medicine and oncology. This perspective will discuss how major advances in our ability to identify and monitor these cells, which include genetic lineage tracing, FACS purification, and robust in vitro clonogenic assays, have changed our view of their roles in many organs. Label retention and quiescence are no longer considered obligatory stem cell features. Furthermore, some tissues have more than one type of stem cell, each used in only particular situations of regenerative stress. Thus, there is no "one size fits all" adult tissue stem cell paradigm.
    MeSH term(s) Adult ; Adult Stem Cells/cytology ; Adult Stem Cells/physiology ; Adult Stem Cells/transplantation ; Cell- and Tissue-Based Therapy ; Humans ; Regeneration
    Language English
    Publishing date 2012-06-14
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Review
    ZDB-ID 2375354-7
    ISSN 1875-9777 ; 1934-5909
    ISSN (online) 1875-9777
    ISSN 1934-5909
    DOI 10.1016/j.stem.2012.04.006
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Replication stress increases mitochondrial metabolism and mitophagy in FANCD2 deficient fetal liver hematopoietic stem cells.

    Mochizuki-Kashio, Makiko / Otsuki, Noriko / Fujiki, Kota / Abdelhamd, Sherif / Kurre, Peter / Grompe, Markus / Iwama, Atsushi / Saito, Kayoko / Nakamura-Ishizu, Ayako

    Frontiers in oncology

    2023  Volume 13, Page(s) 1108430

    Abstract: Fanconi Anemia (FA) is an inherited bone marrow (BM) failure disorder commonly diagnosed during school age. However, in murine models, disrupted function of FA genes leads to a much earlier decline in fetal liver hematopoietic stem cell (FL HSC) number ... ...

    Abstract Fanconi Anemia (FA) is an inherited bone marrow (BM) failure disorder commonly diagnosed during school age. However, in murine models, disrupted function of FA genes leads to a much earlier decline in fetal liver hematopoietic stem cell (FL HSC) number that is associated with increased replication stress (RS). Recent reports have shown mitochondrial metabolism and clearance are essential for long-term BM HSC function. Intriguingly, impaired mitophagy has been reported in FA cells. We hypothesized that RS in FL HSC impacts mitochondrial metabolism to investigate fetal FA pathophysiology. Results show that experimentally induced RS in adult murine BM HSCs evoked a significant increase in mitochondrial metabolism and mitophagy. Reflecting the physiological RS during development in FA, increase mitochondria metabolism and mitophagy were observed in FANCD2-deficient FL HSCs, whereas BM HSCs from adult FANCD2-deficient mice exhibited a significant decrease in mitophagy. These data suggest that RS activates mitochondrial metabolism and mitophagy in HSC.
    Language English
    Publishing date 2023-03-07
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2649216-7
    ISSN 2234-943X
    ISSN 2234-943X
    DOI 10.3389/fonc.2023.1108430
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: Strong ubiquitous micro-promoters for recombinant adeno-associated viral vectors.

    Chai, Sunghee / Wakefield, Leslie / Norgard, Mason / Li, Bin / Enicks, David / Marks, Daniel L / Grompe, Markus

    Molecular therapy. Methods & clinical development

    2023  Volume 29, Page(s) 504–512

    Abstract: Significant progress has been made in developing recombinant adeno-associated virus (rAAV) for clinical gene therapy. While rAAV is a versatile gene delivery platform, its packaging limit of 4.7 kb limits the diseases it can target. Here, we report two ... ...

    Abstract Significant progress has been made in developing recombinant adeno-associated virus (rAAV) for clinical gene therapy. While rAAV is a versatile gene delivery platform, its packaging limit of 4.7 kb limits the diseases it can target. Here, we report two unusually small promoters that enable the expression of larger transgenes than standard promoters. These micro-promoters are only 84 (MP-84) and 135 bp (MP-135) in size but have activity in most cells and tissues comparable to the CAG promoter, the strongest ubiquitous promoter to date. MP-84- and MP-135-based rAAV constructs displayed robust activity in cultured cells from the three different germ-layer lineages. In addition, reporter gene expression was documented in human primary hepatocytes and pancreatic islets and in multiple mouse tissues
    Language English
    Publishing date 2023-05-17
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2872938-9
    ISSN 2329-0501 ; 2329-0501
    ISSN (online) 2329-0501
    ISSN 2329-0501
    DOI 10.1016/j.omtm.2023.05.013
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  8. Article ; Online: Self-cleaving guide RNAs enable pharmacological selection of precise gene editing events in vivo.

    Tiyaboonchai, Amita / Vonada, Anne / Posey, Jeffrey / Pelz, Carl / Wakefield, Leslie / Grompe, Markus

    Nature communications

    2022  Volume 13, Issue 1, Page(s) 7391

    Abstract: Expression of guide RNAs in the CRISPR/Cas9 system typically requires the use of RNA polymerase III promoters, which are not cell-type specific. Flanking the gRNA with self-cleaving ribozyme motifs to create a self-cleaving gRNA overcomes this limitation. ...

    Abstract Expression of guide RNAs in the CRISPR/Cas9 system typically requires the use of RNA polymerase III promoters, which are not cell-type specific. Flanking the gRNA with self-cleaving ribozyme motifs to create a self-cleaving gRNA overcomes this limitation. Here, we use self-cleaving gRNAs to create drug-selectable gene editing events in specific hepatocyte loci. A recombinant Adeno Associated Virus vector targeting the Albumin locus with a promoterless self-cleaving gRNA to create drug resistance is linked in cis with the therapeutic transgene. Gene expression of both are dependent on homologous recombination into the target locus. In vivo drug selection for the precisely edited hepatocytes allows >30-fold expansion of gene-edited cells and results in therapeutic levels of a human Factor 9 transgene. Importantly, self-cleaving gRNA expression is also achieved after targeting weak hepatocyte genes. We conclude that self-cleaving gRNAs are a powerful system to enable cell-type specific in vivo drug resistance for therapeutic gene editing applications.
    MeSH term(s) Humans ; RNA, Guide, CRISPR-Cas Systems/genetics ; Gene Editing ; Homologous Recombination ; RNA, Catalytic/genetics ; Transgenes
    Chemical Substances RNA, Guide, CRISPR-Cas Systems ; RNA, Catalytic
    Language English
    Publishing date 2022-11-30
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-022-35097-5
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  9. Article: Cell networks in the mouse liver during partial hepatectomy.

    Li, Bin / Rodrigo-Torres, Daniel / Pelz, Carl / Innes, Brendan / Canaday, Pamela / Chai, Sunghee / Zandstra, Peter / Bader, Gary D / Grompe, Markus

    bioRxiv : the preprint server for biology

    2023  

    Abstract: In solid tissues homeostasis and regeneration after injury involve a complex interplay between many different cell types. The mammalian liver harbors numerous epithelial and non-epithelial cells and little is known about the global signaling networks ... ...

    Abstract In solid tissues homeostasis and regeneration after injury involve a complex interplay between many different cell types. The mammalian liver harbors numerous epithelial and non-epithelial cells and little is known about the global signaling networks that govern their interactions. To better understand the hepatic cell network, we isolated and purified 10 different cell populations from normal and regenerative mouse livers. Their transcriptomes were analyzed by bulk RNA-seq and a computational platform was used to analyze the cell-cell and ligand-receptor interactions among the 10 populations. Over 50,000 potential cell-cell interactions were found in both the ground state and after partial hepatectomy. Importantly, about half of these differed between the two states, indicating massive changes in the cell network during regeneration. Our study provides the first comprehensive database of potential cell-cell interactions in mammalian liver cell homeostasis and regeneration. With the help of this prediction model, we identified and validated two previously unknown signaling interactions involved in accelerating and delaying liver regeneration. Overall, we provide a novel platform for investigating autocrine/paracrine pathways in tissue regeneration, which can be adapted to other complex multicellular systems.
    Language English
    Publishing date 2023-07-18
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2023.07.16.549116
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: In vivo tracing of the Cytokeratin 14 lineages using self-cleaving guide RNAs and CRISPR/Cas9.

    Tiyaboonchai, Amita / Wakefield, Leslie / Vonada, Anne / May, Catherine L / Dorrell, Craig / Enicks, David / Sairavi, Anusha / Kaestner, Klaus H / Grompe, Markus

    Developmental biology

    2023  Volume 504, Page(s) 120–127

    Abstract: The current gold-standard for genetic lineage tracing in transgenic mice is based on cell-type specific expression of Cre recombinase. As an alternative, we developed a cell-type specific CRISPR/spCas9 system for lineage tracing. This method relies on ... ...

    Abstract The current gold-standard for genetic lineage tracing in transgenic mice is based on cell-type specific expression of Cre recombinase. As an alternative, we developed a cell-type specific CRISPR/spCas9 system for lineage tracing. This method relies on RNA polymerase II promoter driven self-cleaving guide RNAs (scgRNA) to achieve tissue-specificity. To demonstrate proof-of-principle for this approach a transgenic mouse was generated harbouring a knock-in of a scgRNA into the Cytokeratin 14 (Krt14) locus. Krt14 expression marks the stem cells of squamous epithelium in the skin and oral mucosa. The scgRNA targets a Stop cassette preceding a fluorescent reporter in the Ai9-tdtomato mouse. Ai9-tdtomato reporter mice harbouring this allele along with a spCas9 transgene demonstrated precise marking of the Krt14 lineage. We conclude that RNA polymerase II promoter driven scgRNAs enable the use of CRISPR/spCas9 for genetic lineage tracing.
    MeSH term(s) Animals ; Mice ; CRISPR-Cas Systems/genetics ; Integrases/genetics ; Keratin-14/genetics ; Keratin-14/metabolism ; Mice, Transgenic ; Promoter Regions, Genetic/genetics ; RNA Polymerase II/genetics ; RNA Polymerase II/metabolism
    Chemical Substances Integrases (EC 2.7.7.-) ; Keratin-14 ; RNA Polymerase II (EC 2.7.7.-) ; Krt14 protein, mouse
    Language English
    Publishing date 2023-10-07
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 1114-9
    ISSN 1095-564X ; 0012-1606
    ISSN (online) 1095-564X
    ISSN 0012-1606
    DOI 10.1016/j.ydbio.2023.09.011
    Database MEDical Literature Analysis and Retrieval System OnLINE

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