ingest cdrApp 2017-08-15T23:17:01.012Z d91e81c8-5a8a-4e8a-976c-cad4e396e5ee modifyDatastreamByValue RELS-EXT fedoraAdmin 2017-08-15T23:17:32.795Z Setting exclusive relation modifyDatastreamByValue RELS-EXT fedoraAdmin 2017-08-15T23:17:48.804Z Setting exclusive relation addDatastream MD_TECHNICAL fedoraAdmin 2017-08-15T23:17:58.924Z Adding technical metadata derived by FITS modifyDatastreamByValue RELS-EXT fedoraAdmin 2017-08-15T23:18:17.245Z Setting exclusive relation addDatastream MD_FULL_TEXT fedoraAdmin 2017-08-15T23:18:27.271Z Adding full text metadata extracted by Apache Tika modifyDatastreamByValue RELS-EXT fedoraAdmin 2017-08-15T23:18:45.079Z Setting exclusive relation modifyDatastreamByValue RELS-EXT cdrApp 2017-08-22T13:59:06.709Z Setting exclusive relation modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2017-11-06T16:10:40.874Z modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2018-01-25T03:13:03.222Z modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2018-01-27T03:51:26.260Z modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2018-03-13T23:38:05.491Z modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2018-05-16T21:11:39.700Z modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2018-07-10T22:11:20.026Z modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2018-07-17T18:20:04.958Z modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2018-08-08T17:46:46.359Z modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2018-08-15T14:54:00.047Z modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2018-08-16T17:56:58.585Z modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2018-09-21T15:26:22.432Z modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2018-09-26T18:23:28.407Z modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2018-10-11T19:12:19.347Z modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2019-02-28T02:42:15.068Z modifyDatastreamByValue MD_DESCRIPTIVE cdrApp 2019-03-19T21:59:28.571Z Leah Norona Author Curriculum in Toxicology School of Medicine TEMPORAL CHARACTERIZATION OF A THREE-DIMENSIONAL BIOPRINTED MODEL PROVIDES NEW INSIGHT INTO EARLY EVENTS UNDERLYING COMPOUND-INDUCED FIBROTIC LIVER INJURY Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. Summer 2017 2017 Toxicology 3D bioprinted liver, compound-induced fibrosis, in vitro, liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text Leah Norona Author Curriculum in Toxicology School of Medicine Temporal Characterization of a Three-Dimensional Bioprinted Model Provides New Insight into Early Events Underlying Compound-Induced Fibrotic Liver Injury Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. Summer 2017 2017 Toxicology 3D bioprinted liver, compound-induced fibrosis, in vitro, liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text Leah Norona Creator Curriculum in Toxicology School of Medicine Temporal Characterization of a Three-Dimensional Bioprinted Model Provides New Insight into Early Events Underlying Compound-Induced Fibrotic Liver Injury Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. Summer 2017 2017 Toxicology 3D bioprinted liver, compound-induced fibrosis, in vitro, liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text Leah Norona Creator Curriculum in Toxicology School of Medicine Temporal Characterization of a Three-Dimensional Bioprinted Model Provides New Insight into Early Events Underlying Compound-Induced Fibrotic Liver Injury Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. Summer 2017 2017 Toxicology 3D bioprinted liver, compound-induced fibrosis, in vitro, liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text Leah Norona Creator Curriculum in Toxicology School of Medicine Temporal Characterization of a Three-Dimensional Bioprinted Model Provides New Insight into Early Events Underlying Compound-Induced Fibrotic Liver Injury Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. 2017-08 2017 Toxicology 3D bioprinted liver, compound-induced fibrosis, in vitro, liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text Leah Norona Creator Curriculum in Toxicology School of Medicine Temporal Characterization of a Three-Dimensional Bioprinted Model Provides New Insight into Early Events Underlying Compound-Induced Fibrotic Liver Injury Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. 2017 Toxicology 3D bioprinted liver, compound-induced fibrosis, in vitro, liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text 2017-08 Leah Norona Creator Curriculum in Toxicology School of Medicine Temporal Characterization of a Three-Dimensional Bioprinted Model Provides New Insight into Early Events Underlying Compound-Induced Fibrotic Liver Injury Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. 2017 Toxicology 3D bioprinted liver, compound-induced fibrosis, in vitro, liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text 2017-08 Leah Norona Creator Curriculum in Toxicology School of Medicine Temporal Characterization of a Three-Dimensional Bioprinted Model Provides New Insight into Early Events Underlying Compound-Induced Fibrotic Liver Injury Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. 2017 Toxicology 3D bioprinted liver, compound-induced fibrosis, in vitro, liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text 2017-08 Leah Norona Creator Curriculum in Toxicology School of Medicine Temporal Characterization of a Three-Dimensional Bioprinted Model Provides New Insight into Early Events Underlying Compound-Induced Fibrotic Liver Injury Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. 2017 Toxicology 3D bioprinted liver, compound-induced fibrosis, in vitro, liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text 2017-08 Leah Norona Creator Curriculum in Toxicology School of Medicine Temporal Characterization of a Three-Dimensional Bioprinted Model Provides New Insight into Early Events Underlying Compound-Induced Fibrotic Liver Injury Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. 2017 Toxicology 3D bioprinted liver, compound-induced fibrosis, in vitro, liver fibrosis eng Doctor of Philosophy Dissertation Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text 2017-08 University of North Carolina at Chapel Hill Degree granting institution Leah Norona Creator Curriculum in Toxicology School of Medicine Temporal Characterization of a Three-Dimensional Bioprinted Model Provides New Insight into Early Events Underlying Compound-Induced Fibrotic Liver Injury Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. 2017 Toxicology 3D bioprinted liver, compound-induced fibrosis, in vitro, liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text 2017-08 Leah Norona Creator Curriculum in Toxicology School of Medicine Temporal Characterization of a Three-Dimensional Bioprinted Model Provides New Insight into Early Events Underlying Compound-Induced Fibrotic Liver Injury Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. 2017 Toxicology 3D bioprinted liver, compound-induced fibrosis, in vitro, liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text 2017-08 Leah Norona Creator Curriculum in Toxicology School of Medicine Temporal Characterization of a Three-Dimensional Bioprinted Model Provides New Insight into Early Events Underlying Compound-Induced Fibrotic Liver Injury Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. 2017 Toxicology 3D bioprinted liver; compound-induced fibrosis; in vitro; liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text 2017-08 Leah Norona Creator Curriculum in Toxicology School of Medicine Temporal Characterization of a Three-Dimensional Bioprinted Model Provides New Insight into Early Events Underlying Compound-Induced Fibrotic Liver Injury Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. 2017 Toxicology 3D bioprinted liver, compound-induced fibrosis, in vitro, liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text 2017-08 Leah Norona Creator Curriculum in Toxicology School of Medicine Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. 2017 Toxicology 3D bioprinted liver; compound-induced fibrosis; in vitro; liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Toxicology Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text 2017-08 Leah Norona Creator Curriculum in Toxicology School of Medicine Hepatic fibrosis develops from a series of complex and cumulative interactions among resident and recruited cells in response to sustained injury, making it a challenge to replicate using standard preclinical models. To understand early resident cell-mediated events that occur during this response, we took a three-dimensional approach using commercially available bioprinted liver tissues (ExVive3DTM Human Liver, Organovo) composed of primary human hepatocytes (HCs), endothelial cells (ECs), and hepatic stellate cells (HSCs). Because these cultures sustain important cell interactions and liver-specific functions over an extended period, we assessed the utility to recapitulate fundamental aspects of fibrogenesis following exposure to prototype fibrogenic agents. We first demonstrate compelling evidence of methotrexate-, TGF-β1-, and thioacetamide-induced fibrogenesis following two weeks of exposure with the rapid accumulation of collagen accompanied by transient cytokine release, HSC activation, and time-dependent upregulation of fibrosis-associated genes. To resolve early compound-induced effects, tissues were maintained post-manufacturing and allowed to reach steady-state cytokine production prior to dosing. Although tissue viability/function was not significantly altered, collagen deposition was attenuated suggesting the cytokine milieu post-manufacturing may influence the progression of the response. Temporal differences in LDH (general injury) and ALT (HC-specific injury) suggest HC injury precedes general, sustained injury following repeated methotrexate exposure. To understand the role of resident macrophages in modulating this response, Kupffer cells (KCs) were incorporated into the model. The pattern of general injury in the modified model suggests KCs shorten the injury window and reduce collagen deposition at the mid timepoint. These findings implicate the modulatory role of KCs during early exposure but suggest they may play a bimodal role during later phases where increased collagen deposition was observed. Because fibrosis is a dynamic response, recovery was also assessed. Monitoring of injury/functional markers following removal of the etiological agent suggests the model retains some biochemical capacity to recover. However, the two-week recovery timeframe may not have been sufficient to visualize collagen regression. This work lays the foundation for a well-defined, dynamic model of compound-induced liver fibrosis that will provide mechanistic insight into the early events underlying fibrogenesis and may inform the development of therapeutic strategies to prevent or reverse fibrosis. 2017 Toxicology 3D bioprinted liver; compound-induced fibrosis; in vitro; liver fibrosis eng Doctor of Philosophy Dissertation University of North Carolina at Chapel Hill Graduate School Degree granting institution Paul Watkins Thesis advisor William Coleman Thesis advisor David Gerber Thesis advisor Stephanie Padilla Thesis advisor Carol Otey Thesis advisor Sharon Presnell Thesis advisor text 2017-08 Norona_unc_0153D_17262.pdf uuid:600cd764-ba56-492b-a568-dc7d92ca02ce 2017-07-20T15:16:22Z proquest 2019-08-15T00:00:00 application/pdf 18677336 yes