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Nishikawa T, Bell A, Brooks JM, Setoyama K, Melis M, Han B, Fukumitsu K, Handa K, Tian J, Kaestner KH, Vodovotz Y, Locker J, Soto-Gutierrez A, Fox IJ. Resetting the transcription factor network reverses terminal chronic hepatic failure. J Clin Invest 2015; 125:1533-44. [PMID: 25774505 DOI: 10.1172/jci73137] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 01/22/2015] [Indexed: 12/16/2022] Open
Abstract
The cause of organ failure is enigmatic for many degenerative diseases, including end-stage liver disease. Here, using a CCl4-induced rat model of irreversible and fatal hepatic failure, which also exhibits terminal changes in the extracellular matrix, we demonstrated that chronic injury stably reprograms the critical balance of transcription factors and that diseased and dedifferentiated cells can be returned to normal function by re-expression of critical transcription factors, a process similar to the type of reprogramming that induces somatic cells to become pluripotent or to change their cell lineage. Forced re-expression of the transcription factor HNF4α induced expression of the other hepatocyte-expressed transcription factors; restored functionality in terminally diseased hepatocytes isolated from CCl4-treated rats; and rapidly reversed fatal liver failure in CCl4-treated animals by restoring diseased hepatocytes rather than replacing them with new hepatocytes or stem cells. Together, the results of our study indicate that disruption of the transcription factor network and cellular dedifferentiation likely mediate terminal liver failure and suggest reinstatement of this network has therapeutic potential for correcting organ failure without cell replacement.
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Serra MP, Marongiu F, Sini M, Laconi E. Hepatocyte senescence in vivo following preconditioning for liver repopulation. Hepatology 2012; 56:760-8. [PMID: 22392699 DOI: 10.1002/hep.25698] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 02/23/2012] [Indexed: 12/20/2022]
Abstract
UNLABELLED In the retrorsine (RS)-based model of massive liver repopulation, preexposure to this naturally occurring alkaloid is sufficient to prime normal host parenchymal cells to be slowly replaced by transplanted normal hepatocytes. The basis for this striking effect is yet to be fully elucidated. In the present studies the possible involvement of cell senescence was investigated. Fischer 344 rats were treated according to the RS-based protocol for hepatocyte transplantation, i.e., two doses of RS, 2 weeks apart, and were killed at 4 or 8 weeks after treatment. Control groups were given saline. Expression of senescence-associated beta-galactosidase was greatly induced in hepatocytes exposed to RS. In addition, several other changes that have been related to cell senescence were observed: these included markers of persistent activation of a DNA damage response, an increased expression of mammalian target of rapamycin, and positive regulators of the cell cycle, together with the induction of p21 and p27 cyclin-dependent kinase inhibitors. Furthermore, RS treatment increased levels of interleukin-6 in the liver, consistent with the activation of a senescence-associated secretory phenotype. CONCLUSION These findings indicate that RS induces hepatocyte senescence in vivo. We propose that cell senescence and the associated secretory phenotype can contribute to the selective growth of transplanted hepatocytes in this system.
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Affiliation(s)
- Maria Paola Serra
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
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Liu L, Yannam GR, Nishikawa T, Yamamoto T, Basma H, Ito R, Nagaya M, Dutta-Moscato J, Stolz DB, Duan F, Kaestner KH, Vodovotz Y, Soto-Gutierrez A, Fox IJ. The microenvironment in hepatocyte regeneration and function in rats with advanced cirrhosis. Hepatology 2012; 55:1529-39. [PMID: 22109844 PMCID: PMC3700584 DOI: 10.1002/hep.24815] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Accepted: 10/29/2011] [Indexed: 12/26/2022]
Abstract
UNLABELLED In advanced cirrhosis, impaired function is caused by intrinsic damage to the native liver cells and from the abnormal microenvironment in which the cells reside. The extent to which each plays a role in liver failure and regeneration is unknown. To examine this issue, hepatocytes from cirrhotic and age-matched control rats were isolated, characterized, and transplanted into the livers of noncirrhotic hosts whose livers permit extensive repopulation with donor cells. Primary hepatocytes derived from livers with advanced cirrhosis and compensated function maintained metabolic activity and the ability to secrete liver-specific proteins, whereas hepatocytes derived from cirrhotic livers with decompensated function failed to maintain metabolic or secretory activity. Telomere studies and transcriptomic analysis of hepatocytes recovered from progressively worsening cirrhotic livers suggest that hepatocytes from irreversibly failing livers show signs of replicative senescence and express genes that simultaneously drive both proliferation and apoptosis, with a later effect on metabolism, all under the control of a central cluster of regulatory genes, including nuclear factor κB and hepatocyte nuclear factor 4α. Cells from cirrhotic and control livers engrafted equally well, but those from animals with cirrhosis and failing livers showed little initial evidence of proliferative capacity or function. Both, however, recovered more than 2 months after transplantation, indicating that either mature hepatocytes or a subpopulation of adult stem cells are capable of full recovery in severe cirrhosis. CONCLUSION Transplantation studies indicate that the state of the host microenvironment is critical to the regenerative potential of hepatocytes, and that a change in the extracellular matrix can lead to regeneration and restoration of function by cells derived from livers with end-stage organ failure.
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Affiliation(s)
- Liping Liu
- Department of Surgery, University of Nebraska Medical Center, Omaha, NE
| | | | - Taichiro Nishikawa
- Department of Surgery, Children’s Hospital of Pittsburgh and McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA
| | | | - Hesham Basma
- Department of Surgery, University of Nebraska Medical Center, Omaha, NE
| | - Ryotaro Ito
- Department of Surgery, Children’s Hospital of Pittsburgh and McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Masaki Nagaya
- Department of Surgery, Children’s Hospital of Pittsburgh and McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Joyeeta Dutta-Moscato
- Department of Surgery, University of Pittsburgh and Center for Inflammation and Regenerative Modeling, McGowan Institute for Regenerative Medicine, Pittsburgh, PA
| | - Donna B. Stolz
- Department of Cell Biology and Physiology, University of Pittsburgh, Pittsburgh, PA
| | - Fenghai Duan
- Center for Statistical Sciences, Brown University, Providence RI
| | - Klaus H. Kaestner
- Department of Genetics, University of Pennsylvania, Philadelphia, PA
| | - Yoram Vodovotz
- Department of Surgery, University of Pittsburgh and Center for Inflammation and Regenerative Modeling, McGowan Institute for Regenerative Medicine, Pittsburgh, PA
| | - Alejandro Soto-Gutierrez
- Department of Surgery, Children’s Hospital of Pittsburgh and McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Ira J. Fox
- Department of Surgery, Children’s Hospital of Pittsburgh and McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA
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Oertel M. Fetal liver cell transplantation as a potential alternative to whole liver transplantation? J Gastroenterol 2011; 46:953-65. [PMID: 21698354 DOI: 10.1007/s00535-011-0427-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 05/02/2011] [Indexed: 02/04/2023]
Abstract
Because organ shortage is the fundamental limitation of whole liver transplantation, novel therapeutic options, especially the possibility of restoring liver function through cell transplantation, are urgently needed to treat end-stage liver diseases. Groundbreaking in vivo studies have shown that transplanted hepatocytes are capable of repopulating the rodent liver. The two best studied models are the urokinase plasminogen activator (uPA) transgenic mouse and the fumarylacetoacetate hydrolase (FAH)-deficient mouse, in which genetic modifications of the recipient liver provide a tissue environment in which there is extensive liver injury and selection pressure favoring the proliferation and survival of transplanted hepatocytes. Because transplanted hepatocytes do not significantly repopulate the (near-)normal liver, attention has been focused on finding alternative cell types, such as stem or progenitor cells, that have a higher proliferative potential than hepatocytes. Several sources of stem cells or stem-like cells have been identified and their potential to repopulate the recipient liver has been evaluated in certain liver injury models. However, rat fetal liver stem/progenitor cells (FLSPCs) are the only cells identified to date that can effectively repopulate the (near-)normal liver, are morphologically and functionally fully integrated into the recipient liver, and remain viable long-term. Even though primary human fetal liver cells are not likely to be routinely used for clinical liver cell repopulation in the future, using or engineering candidate cells exhibiting the characteristics of FLSPCs suggests a new direction in developing cell transplantation strategies for therapeutic liver replacement. This review will give a brief overview concerning the existing animal models and cell sources that have been used to restore normal liver structure and function, and will focus specifically on the potential of FLSPCs to repopulate the liver.
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Laconi S, Doratiotto S, Montisci S, Pani P, Laconi E. Repopulation by endogenous hepatocytes does not reconstitute liver mass in rats treated with retrorsine. Cell Transplant 2009; 17:1415-21. [PMID: 19364078 DOI: 10.3727/096368908787648128] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The retrorsine (RS)-based model for massive liver repopulation was laid on the hypothesis that transplanted cells can proliferate in the recipient liver if the growth capacity of endogenous hepatocytes is persistently impaired. In order to directly test this hypothesis, we examined the long-term response to 2/3 partial hepatectomy (PH) in rats pretreated with RS, according to the protocol for liver repopulation. Rats were given RS or saline and 4 weeks later they underwent PH; they were killed up to 16 weeks thereafter. Liver weights, liver DNA, and protein content were significantly lower in the RS group throughout the experimental time considered (e.g., at 16 weeks post-PH relative liver weight was 1.99 +/- 0.30% in RS group vs. 3.06 +/- 0.5% in controls). Regenerative nodules were present in RS-treated livers; they occupied about 3% of the liver at 2 weeks post-PH and this value increased to nearly 50% at 8 weeks and to > 95% at 16 weeks. In conclusion, RS-treated rat liver is unable to recover its original mass for several months following PH, despite the development of regenerative nodules. This long-lasting effect is likely to contribute to the growth of transplanted hepatocytes, leading to massive liver repopulation.
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Affiliation(s)
- Sergio Laconi
- Department of Biomedical Sciences and Biotechnology, Section of Experimental Pathology, University of Cagliari, Cagliari, Italy
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Mukhopadhyay S, Sehgal PB. Discordant regulatory changes in monocrotaline-induced megalocytosis of lung arterial endothelial and alveolar epithelial cells. Am J Physiol Lung Cell Mol Physiol 2006; 290:L1216-26. [PMID: 16414977 DOI: 10.1152/ajplung.00535.2005] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Monocrotaline (MCT) causes pulmonary hypertension in the rat by a mechanism characterized by megalocytosis (enlarged cells with enlarged endoplasmic reticulum and Golgi and a cell cycle arrest) of pulmonary arterial endothelial (PAEC), arterial smooth muscle, and type II alveolar epithelial cells. In cell culture, although megalocytosis is associated with a block in entry into mitosis in both lung endothelial and epithelial cells, DNA synthesis is stimulated in endothelial but inhibited in epithelial cells. The molecular mechanism(s) for this dichotomy are unclear. While MCTP-treated PAEC and lung epithelial (A549) cells both showed an increase in the “promitogenic” transcription factor STAT3 levels and in the IL-6-induced nuclear pool of PY-STAT3, this was transcriptionally inactive in A549 but not in PAEC cells. This lack of transcriptional activity of STAT3 in A549 cells correlated with the cytoplasmic sequestration of the STAT3 coactivators CBP/p300 and SRC1/NcoA in A549 cells but not in PAEC. Both cell types displayed a Golgi trafficking block, loss of caveolin-1 rafts, and increased nuclear Ire1α, but an incomplete unfolded protein response (UPR) with little change in levels of UPR-induced chaperones including GRP78/BiP. There were discordant alterations in cell cycle regulatory proteins in the two cell types such as increase in levels of both cyclin D1 and p21 simultaneously, but with a decrease in cdc2/cdk1, a kinase required for entry into mitosis. While both cell types showed increased cytoplasmic geminin, the DNA synthesis-initiating protein Cdt1 was predominantly nuclear in PAEC but remained cytoplasmic in A549 cells, consistent with the stimulation of DNA synthesis in the former but an inhibition in the latter cell type. Thus differences in cell type-specific alterations in subcellular trafficking of critical regulatory molecules (such as CBP/p300, SRC1/NcoA, Cdt1) likely account for the dichotomy of the effects of MCTP on DNA synthesis in endothelial and epithelial cells.
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Affiliation(s)
- Somshuvra Mukhopadhyay
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY 10595, USA
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Pitzalis S, Doratiotto S, Greco M, Montisci S, Pasciu D, Porcu G, Pani P, Laconi S, Laconi E. Cyclin D1 is up-regulated in hepatocytes in vivo following cell-cycle block induced by retrorsine. J Hepatol 2005; 43:485-90. [PMID: 16023250 DOI: 10.1016/j.jhep.2005.03.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Revised: 03/10/2005] [Accepted: 03/16/2005] [Indexed: 12/04/2022]
Abstract
BACKGROUND/AIMS We reported massive liver repopulation by transplanted hepatocytes in rats given retrorsine (RS), a pyrrolizidine alkaloid which blocks proliferation of resident cells. In these studies, molecular alterations induced by RS on hepatocyte cell cycle were investigated. METHODS Animals were treated according to the protocol for liver repopulation, i.e. two injections of RS (30 mg/kg) followed by two-thirds partial hepatectomy (PH) and were sacrificed at various time points thereafter. Livers were analyzed for the expression of cell cycle-related genes. RESULTS Prior to PH, increased cyclin D1 mRNA and protein levels were found in livers of RS-treated rats. Expression of PCNA was also increased; however, DNA synthesis was not significantly changed. Other cyclins, including cyclin B and cyclin E, were not induced. Cyclin D1 expression increased in controls post-PH and then declined by 48 h, as expected. By contrast, no such modulation of cyclin D1 levels was seen in RS group receiving PH and expression remained high at 48 h, without mitotic division. CONCLUSIONS Exposure to RS is able to block cell cycle progression after cyclin D1 and PCNA induction, but prior to S phase. Such persistent block outside the resting phase may contribute to the selective replacement of resident cells during liver repopulation.
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Affiliation(s)
- Sabrina Pitzalis
- Section of Experimental Pathology, Department of Biomedical Sciences and Biotechnology, University of Cagliari, Via Porcell, 4, 09125 Cagliari, Italy
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Abstract
Pyrrolizidine alkaloids initiate disease in the lung (pulmonary hypertension), liver (veno-occlusive disease and cirrhosis), and kidneys (afferent arteriolar block and mesangiolysis) by inducing a megalocytotic phenotype in target endothelial and parenchymal cells. A "hit-and-run" type of exposure to the bioactive pyrrolizidine results, within 2-3 days, in enlarged cells with large nuclei and enlarged Golgi and endoplasmic reticulum, while the cells remain in G2/M block. In the present study, we recapitulated monocrotaline pyrrole (MCTP)-induced megalocytosis in cultures of bovine pulmonary arterial endothelial cells (PAEC), human Hep3B hepatocytes, human type II-like alveolar epithelial cells (A549), and human pulmonary arterial smooth muscle cells (PASMC) and investigated the subcellular mechanism involved. There was an inverse relationship between reduction in caveolin (Cav)-1 levels and stimulation of promitogenic STAT3 and ERK1/2 cell signaling. In megalocytotic PAEC, the Golgi scaffolding protein GM130 was shifted from membranes with heavy density to those with a lighter density. This lighter Golgi fraction was enriched for hypo-oligomeric Cav-1, indicating dysfunctional trafficking of cargo. Immunofluorescence imaging studies confirmed the trapping of Cav-1 in a GM130-positive Golgi compartment. There was an increase in Ser25 phosphorylation of GM130 (typically a prelude to Golgi fragmentation and mitosis) and increased association between pGM130, cdc2 kinase, and Cav-1. Nevertheless, megalocytotic MCTP-treated cells showed reduced entry into mitosis upon stimulation with 2-methoxyestradiol (2-ME), reduced 2-ME-induced Golgi fragmentation, and a slowing of Golgi reassembly after nocodazole-induced fragmentation. These data suggest that a disruption of the trafficking and mitosis sensor functions of the Golgi may represent the subcellular mechanism leading to MCTP-induced megalocytosis ("the Golgi blockade hypothesis").
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Affiliation(s)
- Mehul Shah
- Dept. of Cell Biology and Anatomy, New York Medical College, 201 Basic Sciences Bldg., Valhalla, NY 10595, USA
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Avril A, Pichard V, Bralet MP, Ferry N. Mature hepatocytes are the source of small hepatocyte-like progenitor cells in the retrorsine model of liver injury. J Hepatol 2004; 41:737-43. [PMID: 15519645 DOI: 10.1016/j.jhep.2004.07.029] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2004] [Revised: 07/12/2004] [Accepted: 07/22/2004] [Indexed: 02/08/2023]
Abstract
BACKGROUND/AIMS Mature hepatocytes divide to restore liver mass after injury. However, when hepatocyte division is impaired by retrorsine poisoning, regeneration proceeds from another cell type: the small hepatocyte-like progenitor cells (SHPCs). Our aim was to test whether SHPCs could originate from mature hepatocytes. METHODS Mature hepatocytes were genetically labeled using retroviral vectors harboring the beta-galactosidase gene. After labeling, retrorsine was administered to rats followed by a partial hepatectomy to trigger regeneration. A liver biopsy was performed one month after surgery and rats were sacrificed one month later. RESULTS We observed the proliferation of small hepatocytes arranged in clusters in liver biopsies. These cells expressed Ki67 antigen and displayed a high mitotic index. At sacrifice, regeneration was completed and clusters had merged. A significant proportion of clusters also expressed beta-galactosidase demonstrating their origin from labeled mature hepatocytes. Finally, the overall proportion of beta-galactosidase positive cells was identical at the time of hepatectomy as well as in liver biopsy and at sacrifice. CONCLUSIONS The constant proportion of beta-galactosidase positive cells during the regeneration process demonstrates that mature hepatocytes are randomly recruited to proliferate and compensate parenchyma loss in this model. Furthermore, mature hepatocytes are the source of SHPC after retrorsine injury.
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Affiliation(s)
- Audrey Avril
- Biothérapies Hépatiques, CIC-INSERM 00-04, CHU Hôtel-Dieu, 44093 Nantes Cedex 01, France
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Ogawa K, Ochoa ER, Borenstein J, Tanaka K, Vacanti JP. The generation of functionally differentiated, three-dimensional hepatic tissue from two-dimensional sheets of progenitor small hepatocytes and nonparenchymal cells. Transplantation 2004; 77:1783-9. [PMID: 15223892 DOI: 10.1097/01.tp.0000131153.78169.24] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The authors' laboratory has investigated tissue engineering of the liver as a novel approach for treating end-stage liver disease. Fabrication of thick, viable, three-dimensional liver tissue is limited by the lack of vascularity in the tissue-engineered constructs. To overcome this limitation, the authors fabricated three-dimensional, vascularized liver tissue in vivo from two-dimensional cell sheets created from small hepatocytes (SHC) and nonparenchymal cells (NPC) implanted into rat omentum. METHODS SHC and NPC were cultured on a silicon wafer and lifted as monolayer cell sheets. After maximal hepatotrophic stimulation was induced in the host by injecting retrorsine, creating a portacaval shunt, and performing a partial hepatectomy, these sheets were placed onto the omentum and then rolled into a three-dimensional cylinder. RESULTS New tissue consisting of both hepatocytes and bile duct-like structures formed by 2 weeks, and the mass of hepatocytes increased in size up to 2 months. The hepatocytes in these constructs were immunohistochemically positive for albumin and transferrin, and bile duct-like structures were positive for gamma-glutamyl transpeptidase, which suggests that they possess liver-specific function. Electron microscopy also revealed structures resembling bile canaliculi. CONCLUSIONS Functional, morphologically complex new tissue was generated from morphologically simple monolayer cell sheets of SHC and NPC. These results represent an essential step toward the design of tissue-engineered complex vascularized thick tissue.
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Affiliation(s)
- Kohei Ogawa
- Department of Surgery, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA
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Laconi S, Pillai S, Porcu PP, Shafritz DA, Pani P, Laconi E. Massive liver replacement by transplanted hepatocytes in the absence of exogenous growth stimuli in rats treated with retrorsine. Am J Pathol 2001; 158:771-7. [PMID: 11159214 PMCID: PMC1850302 DOI: 10.1016/s0002-9440(10)64019-9] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/06/2000] [Indexed: 02/07/2023]
Abstract
A strategy for hepatocyte transplantation was recently developed whereby massive replacement of the recipient liver is achieved after a combined treatment with retrorsine, a pyrrolizidine alkaloid, and partial hepatectomy. We now investigated whether liver repopulation could occur in this animal model in the absence of any exogenous growth stimuli (eg, partial hepatectomy) for the transplanted cells. Dipeptidyl-peptidase type IV-deficient (DPPIV-) rats were used as recipients. Rats were given two injections of retrorsine (30 mg/kg each, 2 weeks apart), followed by transplantation of 2 x 10(6) hepatocytes isolated from a normal, syngeneic, DPPIV+ donor. At 2 weeks after transplantation, clusters of DPPIV+ hepatocytes occupied 3.3 +/- 0.9% of host liver, increasing to 38.2 +/- 6.3% at 2 months, and to 65.9 +/- 8.8% at 5 months. By 1 year, >95% of the original hepatocytes were replaced by donor-derived cells. Serum parameters related both to hepatocyte function and integrity (including glucose, bilirubin, total proteins, cholinesterase, alanine aminotransferase, and alkaline phosphatase) were in the normal range in retrorsine-treated and repopulated animals. These results provide further insights toward developing strategies for effective liver repopulation by transplanted hepatocytes with reduced toxicity for the host and potential clinical applicability.
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Affiliation(s)
- S Laconi
- Dipartimento di Scienze Mediche e Biotecnologie, Sezione di Patologia Sperimentale, Università di Cagliari, Cagliari, Italy
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Abstract
Retrorsine is a member of the pyrrolizidine alkaloid (PA) family of naturally occurring compounds found in a large number of plant species worldwide. The cytotoxic, mutagenic, and antimitotic effects of PAs have made them targets for studies designed to determine their potential contributions to carcinogen esis and their usefulness for anticancer therapy. Evidence from the literature suggests that bioactivation of PAs by liver cytochrome P450 (CYP) enzymes is required for their toxicity. However, the specific CYP isozymes that are involved in retrorsine metabolism have not been identified. To address this issue, we administered retrorsine to a cohort of young adult male rats and examined induction or enhanced expression of mRNA and protein for widely studied hepatic CYP isoforms spanning four families together with the essential enzyme CYP reductase. The protein levels of normally expressed CYPs 1A2, 2B1/2, and 2E1 increase significantly in rat liver microsomes from retrorsine-treated rats compared to untreated control rats (P < 0. 05), but protein levels of CYP 4A3, CYP 3A1, and CYP reductase were unchanged after retrorsine treatment. In addition, CYP 1A1 mRNA and protein, which are not detectable in the livers of control rats, were induced after retrorsine exposure. The results of the present study demonstrate enhanced or induced expression of hepatic CYPs 1A1, 1A2, 2E1, and 2B1/2 in response to retrorsine exposure in rats, suggesting that one or more of these enzymes may be involved in retrorsine metabolism.
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Affiliation(s)
- G J Gordon
- Department of Pathology and Laboratory Medicine Curriculum in Toxicology, UNC Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina, 27599, USA
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Kaihara S, Borenstein J, Koka R, Lalan S, Ochoa ER, Ravens M, Pien H, Cunningham B, Vacanti JP. Silicon micromachining to tissue engineer branched vascular channels for liver fabrication. Tissue Eng 2000; 6:105-17. [PMID: 10941206 DOI: 10.1089/107632700320739] [Citation(s) in RCA: 266] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
To date, many approaches to engineering new tissue have emerged and they have all relied on vascularization from the host to provide permanent engraftment and mass transfer of oxygen and nutrients. Although this approach has been useful in many tissues, it has not been as successful in thick, complex tissues, particularly those comprising the large vital organs such as the liver, kidney, and heart. In this study, we report preliminary results using micromachining technologies on silicon and Pyrex surfaces to generate complete vascular systems that may be integrated with engineered tissue before implantation. Using standard photolithography techniques, trench patterns reminiscent of branched architecture of vascular and capillary networks were etched onto silicon and Pyrex surfaces to serve as templates. Hepatocytes and endothelial cells were cultured and subsequently lifted as single-cell monolayers from these two-dimensional molds. Both cell types were viable and proliferative on these surfaces. In addition, hepatocytes maintained albumin production. The lifted monolayers were then folded into compact three-dimensional tissues. Thus, with the use microfabrication technology in tissue engineering, it now seems feasible to consider lifting endothelial cells as branched vascular networks from two-dimensional templates that may ultimately be combined with layers of parenchymal tissue, such as hepatocytes, to form three-dimensional conformations of living vascularized tissue for implantation.
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Affiliation(s)
- S Kaihara
- Department of Surgery, Harvard Medical School and the Massachusetts General Hospital, Boston, Massachusetts 02114, USA
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Gordon GJ, Coleman WB, Hixson DC, Grisham JW. Liver regeneration in rats with retrorsine-induced hepatocellular injury proceeds through a novel cellular response. Am J Pathol 2000; 156:607-19. [PMID: 10666390 PMCID: PMC1850042 DOI: 10.1016/s0002-9440(10)64765-7] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The adult rodent liver contains at least two recognized populations of cells with stem-like properties that contribute to liver repair/regeneration under different pathophysiological circumstances: (i) unipotential committed progenitor cells (differentiated hepatocytes and biliary epithelial cells) and (ii) multipotential nonparenchymal progenitor cells (oval cells). In retrorsine-induced hepatocellular injury the capacity of fully differentiated rat hepatocytes to replicate is severely impaired and massive proliferation of oval cells does not occur. Nevertheless, retrorsine-exposed rats can replace their entire liver mass after 2/3 surgical partial hepatectomy through the emergence and expansion of a population of small hepatocyte-like progenitor cells that expresses phenotypic characteristics of fetal hepatoblasts, oval cells, and fully differentiated hepatocytes, but differ distinctly from each type of cell. The activation, proliferation, and complete regeneration of normal liver structure from small hepatocyte-like progenitor cells have not been recognized in other models of liver injury characterized by impaired hepatocyte replication. We suggest that the selective emergence and expansion of small hepatocyte-like progenitor cells observed in the retrorsine model reflect a novel mechanism of complete liver regeneration in the adult rat. Furthermore, we suggest that these cells may represent a novel progenitor cell population that (i) responds to liver deficit when the replication capacity of differentiated hepatocytes is impaired, (ii) expresses an extensive proliferative capacity, (iii) can give rise to large numbers of progeny hepatocytes, and (iv) can restore tissue mass.
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Affiliation(s)
- G J Gordon
- Department of Pathology, Curriculum in Toxicology, UNC Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
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Affiliation(s)
- E Laconi
- Department of Medical Sciences, University of Cagliari, Oncology Hospital "A. Businco," Cagliari, Italy.
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Laconi S, Curreli F, Diana S, Pasciu D, De Filippo G, Sarma DS, Pani P, Laconi E. Liver regeneration in response to partial hepatectomy in rats treated with retrorsine: a kinetic study. J Hepatol 1999; 31:1069-74. [PMID: 10604581 DOI: 10.1016/s0168-8278(99)80320-1] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND/AIM We have designed an experimental model in which transplantation of normal hepatocytes into rats previously treated with retrorsine (a naturally-occurring pyrrolizidine alkaloid) results in near-complete replacement of the recipient liver by donor-derived cells. Two/thirds partial hepatectomy was found to be essential for this process to occur. To probe this finding, in the present study we describe the kinetics of liver regeneration in response to partial hepatectomy in rats given retrorsine. METHODS Six-weeks-old male Fisher 344 rats received retrorsine (2 injections of 30 mg/kg each, i.p., 2 weeks apart), or the vehicle. Four weeks after the last injection, partial hepatectomy was performed and rats were killed at 1, 2, 3, 6, and 15 days thereafter. RESULTS At time zero, i.e. prior to partial hepatectomy, liver weight and total liver DNA content were significantly lower in retrorsine-treated animals compared to controls (DNA content: 19.2+/-1.7 vs. 25.7+/-1.1 mg/liver). Diffuse megalocytosis (enlarged hepatocytes) was present in the group exposed to retrorsine. By day 3 post-partial hepatectomy liver DNA content in control animals had more than doubled compared to day 1 values (20.2+/-1.5 vs. 8.8+/-1.2), while very little increase was seen in retrorsine-treated rats at the same time points (7.6+/-0.4 vs. 6.1+/-0.2). At 2 weeks after partial hepatectomy, total DNA content returned close to normal levels in the control group (26.9+/-1.0 mg/liver); however, the value was still very low in animals receiving retrorsine (9.1+/-0.7). Data on BrdU labeling were consistent with this pattern and indicated that DNA synthesis following partial hepatectomy was largely inhibited in the retrorsine group. Similarly, no mitotic response was observed in hepatocytes following partial hepatectomy in animals exposed to retrorsine. CONCLUSIONS These results clearly indicate that retrorsine exerts a strong and persistent cell cycle block on hepatocyte proliferation. Further, these results are in agreement with the hypothesis that selective proliferation of transplanted hepatocytes in retrorsine-treated animals is dependent, at least in part, on the persistent cell cycle block imposed by the alkaloid on endogenous parenchymal cells.
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Affiliation(s)
- S Laconi
- Istituto di Patologia Sperimentale, Università di Cagliari, Italy
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Oren R, Dabeva MD, Karnezis AN, Petkov PM, Rosencrantz R, Sandhu JP, Moss SF, Wang S, Hurston E, Laconi E, Holt PR, Thung SN, Zhu L, Shafritz DA. Role of thyroid hormone in stimulating liver repopulation in the rat by transplanted hepatocytes. Hepatology 1999; 30:903-13. [PMID: 10498641 DOI: 10.1002/hep.510300418] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Recently, we reported near-complete repopulation of the rat liver by transplanted hepatocytes using retrorsine (RS), a pyrrolizidine alkaloid that alkylates cellular DNA and blocks proliferation of resident hepatocytes, followed by transplantation of normal hepatocytes in conjunction with two-thirds partial hepatectomy (PH). Because two-thirds PH is not feasible for use in humans, in the present study, we evaluated the ability of thyroid hormone (triiodothyronine [T(3)]), a known hepatic mitogen, to stimulate liver repopulation in the retrorsine model. Because T(3) initiates morphogenesis in amphibians through a process involving both cell proliferation and apoptosis, we also determined whether apoptosis might play a role in the mechanism of hepatocyte proliferation induced by T(3). Following hepatocyte transplantation and repeated injections of T(3), the number of transplanted hepatocytes in the liver of RS-pretreated animals increased progressively to repopulate 60% to 80% of parenchymal cell mass in 60 days. We show further that T(3) treatment augments proliferation of normal hepatocytes, as evidenced by increased histone 3 mRNA and cyclin-dependent kinase 2 (cdk2) expression, and this is followed by apoptosis. These combined effects of T(3) lead to selective proliferation of transplanted hepatocytes in RS-pretreated rats, while endogenous hepatocytes, which are blocked in their proliferative capacity by RS, mainly undergo apoptosis. Thus, T(3) can replace PH in the RS-based rat liver repopulation model and therefore represents a significant advance in developing methods for hepatocyte transplantation.
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Affiliation(s)
- R Oren
- The Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, NY, USA
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Pani P, Laconi S, Pillai S, Scintu F, Curreli F, Shafritz DA, Laconi E. Direct hyperplasia does not enhance the kinetics of liver repopulation in a new model of hepatocyte transplantation in the rat. J Hepatol 1999; 31:354-9. [PMID: 10453951 DOI: 10.1016/s0168-8278(99)80235-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
BACKGROUND/AIMS We have recently developed a new model of extensive liver repopulation by transplanted hepatocytes following exposure to pyrrolizidine alkaloids. In the present study, the effect of 2/3 partial hepatectomy (PH) and that of a potent direct liver mitogen, lead nitrate, were compared in their ability to modulate the kinetics of liver repopulation. METHODS Fischer 344 rats deficient in enzymatic activity for dipeptidyl-peptidase IV (DPPIV-) were used as cell transplantation recipients. They were given 2 doses of the pyrrolizidine alkaloid retrorsine (30 mg/kg, i.p.), 2 weeks apart, followed 2 weeks later by transplantation of 2 x 10(6) hepatocytes (via the portal vein), freshly isolated from a normal congeneic DPPIV+ donor. PH was carried out or a single injection of lead nitrate (100 micromol/kg, i.v.) was administered 2 weeks post-transplantation. Liver samples obtained at different time points post-treatment were processed histochemically for DPPIV activity. RESULTS The percent of liver sections occupied by DPPIV+ hepatocytes was <1% at the time of PH or lead nitrate administration. In animals which underwent PH, it increased to 33.4+/-5.7% at 2 weeks and to 55.6+/-8.5% at 1 month. However, in animals receiving lead nitrate, these percentages were only 3.3+/-1.3% at 2 weeks and 16.2+/-3.9% at 1 month. Repeated injections of lead nitrate had no additional effect. Further experiments indicated that an acute mitogenic response to lead nitrate was present in transplanted cells, while resident hepatocytes were inhibited by retrorsine. CONCLUSIONS These results indicate that direct mitogenic signals (such as those induced by lead nitrate), and compensatory signals (such as those elicited by PH), are not equally effective on kinetics of liver repopulation in this system. The possible reasons for these differential effects are discussed.
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Affiliation(s)
- P Pani
- Istituto di Patologia Sperimentale, Università di Cagliari, Italy
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Abstract
Recently, we described a new strategy for hepatocyte transplantation, using retrorsine/partial hepatectomy (PH) in a DPPIV- mutant Fischer rat model. Treatment of rats with retrorsine, a pyrrolizidine alkaloid, blocks endogenous hepatocytes from proliferating, so that after exposure to this agent coupled with PH and hepatocyte transplantation, transplanted hepatocytes selectively repopulate the liver. In the present study, we determined whether this method of cell transplantation can restore biosynthetic and physiological function in the liver by transplanting normal hepatocytes into rats genetically deficient in albumin synthesis, the Nagase analbuminic rat (NAR). After hepatocyte transplantation, albumin mRNA and protein were identified in the liver by in situ hybridization and immunohistochemistry, respectively, and serum albumin levels were determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Western blot, and enzyme-linked immunosorbent assay (ELISA) methods. At 1 month posttransplantation, large clusters of cells expressing albumin mRNA and protein were identified in the liver, representing approximately 50% of hepatocytes for albumin mRNA and approximately 61% for protein. At 2 months' posttransplantation, cells expressing albumin mRNA represented approximately 77% of hepatocyte mass, and cells expressing albumin protein represented approximately 81% of total hepatocyte mass. Hepatocyte-transplanted NAR also exhibited normal or near-normal serum albumin levels (3.0 +/- 0.2 g/dL). High levels of serum albumin were sustained for the 2-month duration of experiments. These results demonstrate the ability of this protocol for hepatocyte transplantation to restore a major biosynthetic and physiological function of the liver, and suggest its potential use as a method to treat genetic-based or acquired liver diseases.
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Affiliation(s)
- R Oren
- The Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx 10461, NY, USA
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Laconi E, Oren R, Mukhopadhyay DK, Hurston E, Laconi S, Pani P, Dabeva MD, Shafritz DA. Long-term, near-total liver replacement by transplantation of isolated hepatocytes in rats treated with retrorsine. Am J Pathol 1998; 153:319-29. [PMID: 9665494 PMCID: PMC1852941 DOI: 10.1016/s0002-9440(10)65574-5] [Citation(s) in RCA: 294] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Genetically marked hepatocytes from dipeptidyl peptidase (DPP) IV+ Fischer 344 rats were transplanted into the liver of DPPIV- mutant Fischer 344 rats after a combined treatment with retrorsine, a pyrrolizidine alkaloid that blocks the hepatocyte cell cycle, and two-thirds partial hepatectomy. In female rats, clusters of proliferated DPPIV+ hepatocytes containing 20 to 50 cells/cluster, mostly derived from single transplanted cells, were evident at 2 weeks, increasing in size to hundreds of cells per cluster at 1 month and 1000 to several thousand cells per cluster at 2 months, representing 40 to 60% of total hepatocyte mass. This level of hepatocyte replacement remained constant for up to 1 year, the duration of experiments conducted. In male rats, liver replacement occurred more rapidly and was more extensive, with transplanted hepatocytes representing 10 to 15% of hepatocyte mass at 2 weeks, 40 to 50% at 1 month, 90 to 95% at 2 months, 98% at 4 months, and 99% at 9 months. Transplanted hepatocytes were integrated into the parenchymal plates, exhibited unique hepatic biochemical functions, and fully reconstituted a normal hepatic lobular structure. The extensive proliferation of transplanted cells in this setting of persistent inhibition of resident hepatocytes represents a new general model to study basic aspects of liver repopulation with potential applications in chronic liver disease and ex vivo gene therapy.
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Affiliation(s)
- E Laconi
- Istituto di Patologia Sperimentale, Ospedale Oncologico A Businco, University of Cagliari, Italy
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Peterson JE, Payne A, Culvenor CC. Heliotropium europaeum poisoning of sheep with low liver copper concentrations and the preventive efficacy of cobalt and antimethanogen. Aust Vet J 1992; 69:51-6. [PMID: 1316747 DOI: 10.1111/j.1751-0813.1992.tb07448.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In a field experiment in the Mallee district of Victoria, Merlno xBorder Leicester ewes and wethers grazed Heliotropium europaeum (heliotrope) over periods of 3 to 4 months in 4 successive years. By the end of the second year 12% (14 of 120) of the sheep had died; after 4 years the loss attributable to heliotrope was between 18% and 35%. Mortality was not affected by intraruminal treatment with cobalt or antimethanogen. At the end of the experiment the highest concentration of copper in the liver was 1.95 mmol/kg wet weight (approximately 413 micrograms/g dry weight). The relatively low mortality from primary heliotrope poisoning and the low concentration of copper in the liver of sheep grazing the plant are discussed in relation to the contrasting situation that prevails in the Riverina area of New South Wales. The importance of local environmental factors in the management of heliotrope grazing by sheep is emphasised, particularly in relation to the number of seasons in which the plant may be a major component of the diet.
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Affiliation(s)
- J E Peterson
- CSIRO Division of Animal Health, Animal Health Research Laboratory, Parkville, Victoria
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Abstract
Young Merino wethers were used to determine the effects of copper and heliotrope, fed together or separately, on the development of toxicity and the concentration of trace elements in the liver and kidney. In one experiment copper and heliotrope were given concurrently, in a second experiment heliotrope was fed for 12 weeks and copper administration commenced 8 weeks later. The 10 sheep fed heliotrope alone did not show signs of clinical illness but one died and was found to have severe liver damage. Eleven sheep were given copper alone and three developed the clinical signs and lesions of haemolysis. Fourteen sheep were given copper and heliotrope and 13 became ill. Of these, three developed haemolysis, eight became jaundiced and two became weak without developing jaundice. The concentrations of copper in the livers of control and heliotrope-treated sheep, were comparable. In the animals given copper alone, the concentration of copper in the liver was twice as high as that in controls and in those given heliotrope and copper, it was three times as high as in the liver of control sheep. Feeding heliotrope alone induced the histological changes of pyrrolizidine alkaloid toxicity in the liver, but this was not associated with an excessive accumulation of copper or the development of clinical illness. However, it did predispose the animals to the effects of a second toxin since giving heliotrope and copper concurrently, or giving copper subsequent to feeding heliotrope, markedly enhanced the toxicity of the two substances and caused an excessive accumulation of copper in the liver.
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Affiliation(s)
- J M Howell
- School of Veterinary Studies, Murdoch University, Western Australia
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Abstract
A field grazing trial was undertaken to monitor the health and production of crossbred sheep grazing pasture where Echium plantagineum constituted a considerable proportion of the available forage. The trial, conducted for 19 months over successive grazing seasons, demonstrated a significant difference in production, with sheep on the E. plantagineum pasture being lighter and growing less wool compared with sheep on Echium-free pasture. No mortalities involving pyrrolizidine alkaloid poisoning were recorded in sheep grazing E. plantagineum, although there was histological evidence of moderately severe liver damage associated with high liver copper concentrations in at least one sheep following the grazing of large quantities of the plant.
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Affiliation(s)
- J T Seaman
- New South Wales Department of Agriculture and Fisheries, Agricultural Research and Veterinary Centre, Orange
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Ord MJ, Herbert A, Mattocks AR. The ability of bifunctional and monofunctional pyrrole compounds to induce sister-chromatid exchange (SCE) in human lymphocytes and mutations in Salmonella typhimurium. Mutat Res 1985; 149:485-93. [PMID: 3887149 DOI: 10.1016/0027-5107(85)90167-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The ability to induce sister-chromatid exchange (SCE) in human lymphocytes and mutations in Salmonella typhimurium has been assessed for 4 pyrrole compounds. Three of the compounds, 2,3-bishydroxymethyl-1-methylpyrrole (BHMP), 2-hydroxymethyl-1-methylpyrrole (2HMP) and 3-hydroxymethyl-1-methylpyrrole (3HMP) are synthetic pyrrolic alcohols; the fourth compound, dehydroretronecine (DHR) is a metabolite of several naturally occurring pyrrolizidine alkaloids. The activity of these compounds was compared with that of mitomycin C (MMC) and decarbamoyl mitomycin C (DCMMC), chemicals related structurally to the pyrrole compounds. All 6 compounds caused an increase in the numbers of SCEs. Whereas the bifunctional pyrroles, DHR and BHMP, and the mitomycins, MMC and DCMMC, increased levels of SCEs by 8-12 times control levels, the monofunctional pyrroles gave increases of only 2 times. Three of the 4 pyrrole compounds (DHR, BHMP and 3HMP) induced mutations in the Salmonella typhimurium base substitution strain TA92, the fourth (2HMP) was not found to be mutagenic in any of the 8 strains used. The mitomycins induced mutations in the frameshift strain TA94 in addition to the base substitution strain TA92, with DCMMC always more mutagenic and less cytotoxic than MMC. All bifunctional compounds induced more mutations and were less cytotoxic in strains containing an efficient excision-repair system. With the pyrrole compounds numbers of SCEs and mutations were only increased when using chemical concentrations significantly higher than those required for the mitomycins: more than twice as high to produce significant numbers of SCEs and more than 100 times as high to produce equal numbers of mutations.
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Hayes MA, Roberts E, Jago MV, Safe SH, Farber E, Cameron RC. Influences of various xenobiotic inducers on cytocidal toxicity of lasiocarpine and senecionine in primary cultures of rat hepatocytes. J Toxicol Environ Health 1984; 14:683-94. [PMID: 6440999 DOI: 10.1080/15287398409530617] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The influences of in vivo pretreatment with phenobarbitone (PB), 3-methylcholanthrene (3-MC), 2,2',4,4',5,5'-hexachlorobiphenyl (HCBP), and 3,3',4,4'-tetrachlorobiphenyl (TCBP) on cytocidal hepatotoxicity of two pyrrolizidine alkaloids, lasiocarpine (LC) and senecionine (SC), were compared in short-term primary cultures of rat hepatocytes. Toxicity was measured by release of lactate dehydrogenase (LDH) into culture medium at 24 h. LC was slightly more toxic to control hepatocytes than SC in the graded response range of 10-160 microM. PB and HCBP (a PB-type polychlorobiphenyl inducer) similarly potentiated toxicity of SC, and each diminished the degree to which cell killing by LC and SC was inhibited by SKF-525-A. By comparison, 3-MC and TCBP (a 3-MC-type PCB inducer) each diminished toxicity of SC but had little effect on toxicity of LC. Alpha-naphthoflavone (ANF) potentiated toxicity of both LC and SC in hepatocytes induced by 3-MC or TCBP but had little effect on responses of hepatocytes induced by either PB or HDBP. These results indicate that xenobiotics that induce similar patterns of cytochrome P-450 isozymes have qualitatively similar modulating influences on cytocidal hepatotoxicity of pyrrolizidine alkaloids in primary cultures. However, the observed modulating effects could not be explained solely on the basis of altered activation rates by the cytochrome P-450 species known to be induced by the various xenobiotics.
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Mattocks AR. Liver cell enlargement in rats given hydroxymethyl pyrroles analogous to pyrrolizidine alkaloid metabolites, followed later by the hepatotoxin dimethylnitrosamine. Toxicol Lett 1981; 8:201-5. [PMID: 7268803 DOI: 10.1016/0378-4274(81)90101-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Male rats aged 4-5 weeks were given single doses of pyrrolic alcohols having alkylating properties similar to those of pyrrolizidine alkaloid metabolites, followed several days later by one of the hepatotoxins dimethylnitrosamine (DMN), thioacetamide (TA) or carbon tetrachloride. After 24-32 days the livers of animals given the pyrroles 1-methyl-2,3-bishydroxymethylpyrrole (II) or 1-phenyl-5-methyl-2,3-bishydroxymethylpyrrole (V) and then DMN, contained enlarged parenchymal cells (megalocytes) similar to those seen in chronic pyrrolizidine alkaloid poisoning. At this time such abnormal cells were not found in rats given any of the other pyrroles followed by DMN, or compound II and then TA or CCl4.
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Mattocks AR, Legg RF. Antimitotic activity of dehydroretronecine, a pyrrolizidine alkaloid metabolite, and some analogous compounds, in a rat liver parenchymal cell line. Chem Biol Interact 1980; 30:325-36. [PMID: 7379211 DOI: 10.1016/0009-2797(80)90055-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The actions of 13 pyrrolic alcohols with similar chemical properties have been tested on cultured liver cells. Two, dehydroretronecine and dehydrosupinidine, were putative metabolites of hepatotoxic pyrrolizidine alkaloids; the remainder were synthetic. All were either mono- or bi-functional alkylating agents. Groups of cells were exposed to the compounds and were later stimulated to divide by changing the medium, then fixed, stained, and the proportions of cells in mitosis counted and compared with those in similarly treated control cells. Eleven compounds partially or completely inhibited cell division at concentrations of 10(-4) M or less. Bifunctional compounds, including dehydroretronecine and 2,3-bis-hydroxymethyl-1-methylpyrrole, had the highest antimitotic activity coupled with lowest cytotoxicity. The least chemically reactive compound, 3-hydroxymethyl-1-methylpyrrole, was neither antimitotic nor cytotoxic, whereas the monofunctional alkylating agents with highest reactivity, such as 3-hydroxymethyl-1,2-dimethylpyrrole, were the most toxic to the cells. The mitotic block occurred at a post-synthetic stage of the cell cycle, and affected cells could grow to a giant size.
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Peristianis GC, Austwick PK, Carter RL. An ultrastructural investigation of nephrotoxicity in rats induced by feeding cultures of Penicillium verrucosum var. cyclopium. Virchows Arch B Cell Pathol 1978; 28:321-37. [PMID: 103297 DOI: 10.1007/bf02889081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A renal tubular lesion was induced in male rats by giving them a culture homogenate or culture filtrate of Penicillium verrucosum var. cyclopium by gastric gavage for 20 days. The fungus was obtained from stored maize in an area of endemic nephropathy in Bulgaria. Changes in the proximal convoluted tubules were studied by light and electron microscopy. The lesion was confined to the pars recta in the outer stripe of the outer zone of the medulla. It consisted of degeneration and necrosis of epithelial cells, prominent karyomegaly, arrested mitotic divisions and production of binucleate and tetranucleate tubular cells. Two patterns of degeneration occurred with comparable frequency: a vesicular form with pyknotic nucleus and electron lucent degeneration. Nuclei of the epithelial cells in affected tubules contained segregated nucleoli. The necrotic cells were replaced by actively regenerating cells derived from adjacent viable epithelium. The similarity between the tubular lesions induced in rats and the changes found in patients with Balkan endemic nephropathy is discussed.
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Gopinath C, Ford EJ. The effect of ragwort (Senecio jacobea) on the liver of the domestic fowl (Gallus domesticus) : a histopathological and enzyme histochemical study. Br Poult Sci 1977; 18:137-41. [PMID: 143983 DOI: 10.1080/00071667708416340] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
1. Twenty-five 1-week-old male chicks were fed for 6 weeks on a standard diet incorporating 7% dried and ground ragwort (Senecio jacobea). The chicks received the standard diet for a further 6 weeks whilst a control group of 25 similar birds received the standard diet throughout. 2. Two birds from each group were killed at intervals of about 1 week and their livers were examined histologically and histochemically. 3. Ragwort feeding caused megalocytosis, focal necrosis, focal hyperplasia and portal fibrosis. There were no veno-occlusive changes. 4. As the lesion progressed there was an overall loss of enzyme activity especially in the areas of necrosis. The groups of small hyperplastic cells showed normal or increased activity and there was increased enzyme activity in the megalocytes. 5. The development of groups of proliferating cells may be a prelude to the neoplastic changes described in earlier reports of longer term studies of the effects of pyrolizidine alkaloids on the liver of chicks.
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Samuel A, Jago MV. Localization in the cell cycle of the antimitotic action of the pyrrolizidine alkaloid, lasiocarpine and of its metabolite, dehydroheliotridine. Chem Biol Interact 1975; 10:185-97. [PMID: 1126005 DOI: 10.1016/0009-2797(75)90112-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The antimitotic action of the pyrrolizidine alkaloid lasiocarpine on rat liver parenchyma was investigated using as the experimental model the wave of mitosis produced in liver by a single dose of thioacetamide. A single low dose of lasiocarpine administered two weeks before the thioacetamide, almost completely inhibited the mitotic wave without inhibiting to the same extent the preceding wave of DNA synthesis. By the use of selective inhibitors and radioisotope labelling, the location of the mitotic block was found to be either in the latter half of the DNA synthetic phase, S, or early in G2, the post-synthetic phase. The mitotic wave was similarly inhibited by pretreatment of the rats with a single injection of dehydroheliotridine, a pyrrolic metabolite of heliotridine-based pyrrolizidine alkaloids.
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Black DN, Jago MV. Interaction of dehydroheliotridine, a metabolite of heliotridine-based pyrrolizidine alkaloids, with native and heat-denatured deoxyribonucleic acid in vitro. Biochem J 1970; 118:347-53. [PMID: 4319542 PMCID: PMC1179198 DOI: 10.1042/bj1180347] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Dehydroheliotridine, a major pyrrolic metabolite of heliotridine-based pyrrolizidine alkaloids, interacted with both native and heat-denatured DNA in vitro under mildly acid conditions to form a soluble non-diffusible complex as shown by spectral data. The complex formed with heat-denatured DNA was more resistant than heat-denatured DNA alone to the combined action of deoxyribonuclease and phosphodiesterase. Analysis of the resistant fractions suggested the presence of at least one base not obtained from DNA alone.
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