1
|
Lang AL, Nissanka N, Louzada RA, Tamayo A, Pereira E, Moraes CT, Caicedo A. A Defect in Mitochondrial Complex III but Not in Complexes I or IV Causes Early β-Cell Dysfunction and Hyperglycemia in Mice. Diabetes 2023; 72:1262-1276. [PMID: 37343239 PMCID: PMC10451017 DOI: 10.2337/db22-0728] [Citation(s) in RCA: 0] [Impact Index Per Article: 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] [Received: 08/24/2022] [Accepted: 06/04/2023] [Indexed: 06/23/2023]
Abstract
Mitochondrial metabolism and oxidative respiration are crucial for pancreatic β-cell function and stimulus secretion coupling. Oxidative phosphorylation (OxPhos) produces ATP and other metabolites that potentiate insulin secretion. However, the contribution of individual OxPhos complexes to β-cell function is unknown. We generated β-cell-specific, inducible OxPhos complex knock-out (KO) mouse models to investigate the effects of disrupting complex I, complex III, or complex IV on β-cell function. Although all KO models had similar mitochondrial respiratory defects, complex III caused early hyperglycemia, glucose intolerance, and loss of glucose-stimulated insulin secretion in vivo. However, ex vivo insulin secretion did not change. Complex I and IV KO models showed diabetic phenotypes much later. Mitochondrial Ca2+ responses to glucose stimulation 3 weeks after gene deletion ranged from not affected to severely disrupted, depending on the complex targeted, supporting the unique roles of each complex in β-cell signaling. Mitochondrial antioxidant enzyme immunostaining increased in islets from complex III KO, but not from complex I or IV KO mice, indicating that severe diabetic phenotype in the complex III-deficient mice is causing alterations in cellular redox status. The present study highlights that defects in individual OxPhos complexes lead to different pathogenic outcomes. ARTICLE HIGHLIGHTS Mitochondrial metabolism is critical for β-cell insulin secretion, and mitochondrial dysfunction is involved in type 2 diabetes pathogenesis. We determined whether individual oxidative phosphorylation complexes contribute uniquely to β-cell function. Compared with loss of complex I and IV, loss of complex III resulted in severe in vivo hyperglycemia and altered β-cell redox status. Loss of complex III altered cytosolic and mitochondrial Ca2+ signaling and increased expression of glycolytic enzymes. Individual complexes contribute differently to β-cell function. This underscores the role of mitochondrial oxidative phosphorylation complex defects in diabetes pathogenesis.
Collapse
Affiliation(s)
- Anna L. Lang
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL
| | - Nadee Nissanka
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL
| | - Ruy A. Louzada
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL
| | - Alejandro Tamayo
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL
- Department of Molecular Cell and Developmental Biology, University of Miami Miller School of Medicine, Miami, FL
| | - Elizabeth Pereira
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL
| | - Carlos T. Moraes
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL
| | - Alejandro Caicedo
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL
- Department of Molecular Cell and Developmental Biology, University of Miami Miller School of Medicine, Miami, FL
| |
Collapse
|
2
|
Plastini MJ, Desu HL, Ascona MC, Lang AL, Saporta MA, Brambilla R. Transcriptional abnormalities in induced pluripotent stem cell-derived oligodendrocytes of individuals with primary progressive multiple sclerosis. Front Cell Neurosci 2022; 16:972144. [PMID: 36246526 PMCID: PMC9554611 DOI: 10.3389/fncel.2022.972144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 08/16/2022] [Indexed: 11/13/2022] Open
Abstract
Multiple sclerosis (MS) is the most common neurological disorder in young adults and is classically defined as a chronic inflammatory demyelinating disease of the central nervous system (CNS). Although MS affects millions of people worldwide, its underlying cause remains unknown making discovery of effective treatments challenging. Whether intrinsic or extrinsic factors contribute to MS initiation and progression is still unclear. This is especially true for primary progressive MS (PPMS), the rarest form of the disease, in which progressive and irreversible loss of neurological function is often observed in the absence of an overt immune-inflammatory response. To test the hypothesis that intrinsic dysfunction in oligodendrocytes (OLs), the primary targets of damage in MS, may contribute to PPMS etiopathology, we differentiated human induced pluripotent stem cell (hiPSC) lines derived from PPMS and healthy individuals into mature OLs to compare their transcriptional profile. PPMS derived OLs displayed hundreds of differentially expressed genes compared to control OLs, many associated with cell adhesion, apoptosis and inflammation, including the inflammasome component Nlrp2, which was highly upregulated. NLRP2 immunoreactivity in OLs was confirmed in post-mortem PPMS brain tissues, with higher expression than in control tissues. Altogether, our findings suggest that mature OLs in PPMS affected individuals carry intrinsic abnormalities that could contribute, at least in part, to the pathophysiology of this form of the disease.
Collapse
Affiliation(s)
- Melanie J. Plastini
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
- The Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Haritha L. Desu
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
- The Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Maureen C. Ascona
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
- The Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Anna L. Lang
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Mario A. Saporta
- The Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, United States
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Roberta Brambilla
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
- The Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, United States
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
- BRIDGE-Brain Research-Inter-Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
- *Correspondence: Roberta Brambilla,
| |
Collapse
|
3
|
Schnegelberger RD, Lang AL, Arteel GE, Beier JI. Environmental toxicant-induced maladaptive mitochondrial changes: A potential unifying mechanism in fatty liver disease? Acta Pharm Sin B 2021; 11:3756-3767. [PMID: 35024304 PMCID: PMC8727895 DOI: 10.1016/j.apsb.2021.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/29/2021] [Accepted: 08/19/2021] [Indexed: 12/14/2022] Open
Abstract
Occupational and environmental exposures to industrial chemicals are well known to cause hepatotoxicity and liver injury. However, despite extensive evidence showing that exposure can lead to disease, current research approaches and regulatory policies fail to address the possibility that subtle changes caused by low level exposure to chemicals may also enhance preexisting conditions. In recent years, the conceptual understanding of the contribution of environmental chemicals to liver disease has progressed significantly. Mitochondria are often target of toxicity of environmental toxicants resulting in multisystem disorders involving different cells, tissues, and organs. Here, we review persistent maladaptive changes to mitochondria in response to environmental toxicant exposure as a mechanism of hepatotoxicity. With better understanding of the mechanism(s) and risk factors that mediate the initiation and progression of toxicant-induced liver disease, rational targeted therapy can be developed to better predict risk, as well as to treat or prevent this disease.
Collapse
Affiliation(s)
- Regina D. Schnegelberger
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Anna L. Lang
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Gavin E. Arteel
- Department of Medicine, Division of Gastroenterology, Hepatology & Nutrition, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Juliane I. Beier
- Department of Medicine, Division of Gastroenterology, Hepatology & Nutrition, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Environmental & Occupational Health, University of Pittsburgh, Pittsburgh, PA 15213, USA
| |
Collapse
|
4
|
Lang M, Li MD, Jiang KZ, Yoon BC, Mendoza DP, Flores EJ, Rincon SP, Mehan WA, Conklin J, Huang SY, Lang AL, Giao DM, Leslie-Mazwi TM, Kalpathy-Cramer J, Little BP, Buch K. Severity of Chest Imaging is Correlated with Risk of Acute Neuroimaging Findings among Patients with COVID-19. AJNR Am J Neuroradiol 2021; 42:831-837. [PMID: 33541897 DOI: 10.3174/ajnr.a7032] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 12/11/2020] [Indexed: 01/03/2023]
Abstract
BACKGROUND AND PURPOSE Severe respiratory distress in patients with COVID-19 has been associated with higher rate of neurologic manifestations. Our aim was to investigate whether the severity of chest imaging findings among patients with coronavirus disease 2019 (COVID-19) correlates with the risk of acute neuroimaging findings. MATERIALS AND METHODS This retrospective study included all patients with COVID-19 who received care at our hospital between March 3, 2020, and May 6, 2020, and underwent chest imaging within 10 days of neuroimaging. Chest radiographs were assessed using a previously validated automated neural network algorithm for COVID-19 (Pulmonary X-ray Severity score). Chest CTs were graded using a Chest CT Severity scoring system based on involvement of each lobe. Associations between chest imaging severity scores and acute neuroimaging findings were assessed using multivariable logistic regression. RESULTS Twenty-four of 93 patients (26%) included in the study had positive acute neuroimaging findings, including intracranial hemorrhage (n = 7), infarction (n = 7), leukoencephalopathy (n = 6), or a combination of findings (n = 4). The average length of hospitalization, prevalence of intensive care unit admission, and proportion of patients requiring intubation were significantly greater in patients with acute neuroimaging findings than in patients without them (P < .05 for all). Compared with patients without acute neuroimaging findings, patients with acute neuroimaging findings had significantly higher mean Pulmonary X-ray Severity scores (5.0 [SD, 2.9] versus 9.2 [SD, 3.4], P < .001) and mean Chest CT Severity scores (9.0 [SD, 5.1] versus 12.1 [SD, 5.0], P = .041). The pulmonary x-ray severity score was a significant predictor of acute neuroimaging findings in patients with COVID-19. CONCLUSIONS Patients with COVID-19 and acute neuroimaging findings had more severe findings on chest imaging on both radiographs and CT compared with patients with COVID-19 without acute neuroimaging findings. The severity of findings on chest radiography was a strong predictor of acute neuroimaging findings in patients with COVID-19.
Collapse
Affiliation(s)
- M Lang
- Department of Radiology (M.L., M.D.L., B.C.Y., D.P.M., E.J.F., S.P.R., W.A.M., J.C., S.Y.H., J.K.-C., B.P.L., K.B.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - M D Li
- Department of Radiology (M.L., M.D.L., B.C.Y., D.P.M., E.J.F., S.P.R., W.A.M., J.C., S.Y.H., J.K.-C., B.P.L., K.B.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - K Z Jiang
- School of Medicine (K.Z.J.), Baylor College of Medicine, Houston, Texas
| | - B C Yoon
- Department of Radiology (M.L., M.D.L., B.C.Y., D.P.M., E.J.F., S.P.R., W.A.M., J.C., S.Y.H., J.K.-C., B.P.L., K.B.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - D P Mendoza
- Department of Radiology (M.L., M.D.L., B.C.Y., D.P.M., E.J.F., S.P.R., W.A.M., J.C., S.Y.H., J.K.-C., B.P.L., K.B.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - E J Flores
- Department of Radiology (M.L., M.D.L., B.C.Y., D.P.M., E.J.F., S.P.R., W.A.M., J.C., S.Y.H., J.K.-C., B.P.L., K.B.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - S P Rincon
- Department of Radiology (M.L., M.D.L., B.C.Y., D.P.M., E.J.F., S.P.R., W.A.M., J.C., S.Y.H., J.K.-C., B.P.L., K.B.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - W A Mehan
- Department of Radiology (M.L., M.D.L., B.C.Y., D.P.M., E.J.F., S.P.R., W.A.M., J.C., S.Y.H., J.K.-C., B.P.L., K.B.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - J Conklin
- Department of Radiology (M.L., M.D.L., B.C.Y., D.P.M., E.J.F., S.P.R., W.A.M., J.C., S.Y.H., J.K.-C., B.P.L., K.B.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.,Athinoula A. Martinos Center for Biomedical Imaging (J.C., S.Y.H., J.K.-C.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - S Y Huang
- Department of Radiology (M.L., M.D.L., B.C.Y., D.P.M., E.J.F., S.P.R., W.A.M., J.C., S.Y.H., J.K.-C., B.P.L., K.B.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.,Athinoula A. Martinos Center for Biomedical Imaging (J.C., S.Y.H., J.K.-C.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - A L Lang
- Department of Anesthesia, Critical Care, and Pain Medicine (A.L.L.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - D M Giao
- Harvard Medical School (D.M.G.), Boston, Massachusetts
| | | | - J Kalpathy-Cramer
- Department of Radiology (M.L., M.D.L., B.C.Y., D.P.M., E.J.F., S.P.R., W.A.M., J.C., S.Y.H., J.K.-C., B.P.L., K.B.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.,Athinoula A. Martinos Center for Biomedical Imaging (J.C., S.Y.H., J.K.-C.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - B P Little
- Department of Radiology (M.L., M.D.L., B.C.Y., D.P.M., E.J.F., S.P.R., W.A.M., J.C., S.Y.H., J.K.-C., B.P.L., K.B.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - K Buch
- Department of Radiology (M.L., M.D.L., B.C.Y., D.P.M., E.J.F., S.P.R., W.A.M., J.C., S.Y.H., J.K.-C., B.P.L., K.B.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| |
Collapse
|
5
|
Lang M, Buch K, Li MD, Mehan WA, Lang AL, Leslie-Mazwi TM, Rincon SP. Leukoencephalopathy Associated with Severe COVID-19 Infection: Sequela of Hypoxemia? AJNR Am J Neuroradiol 2020; 41:1641-1645. [PMID: 32586959 DOI: 10.3174/ajnr.a6671] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 05/30/2020] [Indexed: 12/18/2022]
Abstract
There is increasing evidence to suggest that complications of coronavirus disease 2019 (COVID-19) infection are not only limited to the pulmonary system but can also involve the central nervous system. Here, we report 6 critically ill patients with COVID-19 infection and neuroimaging findings of leukoencephalopathy. While these findings are nonspecific, we postulate that they may be a delayed response to the profound hypoxemia the patients experienced due to the infection. No abnormal enhancement, hemorrhage, or perfusion abnormalities were noted on MR imaging. In addition, Severe Acute Respiratory Syndrome coronavirus 2 was not detected in the CSF collected from the 2 patients who underwent lumbar puncture. Recognition of COVID-19-related leukoencephalopathy is important for appropriate clinical management, disposition, and prognosis.
Collapse
Affiliation(s)
- M Lang
- From the Departments of Radiology (M.L., K.B., M.D.L., W.A.M., Jr, S.P.R.)
| | - K Buch
- From the Departments of Radiology (M.L., K.B., M.D.L., W.A.M., Jr, S.P.R.)
| | - M D Li
- From the Departments of Radiology (M.L., K.B., M.D.L., W.A.M., Jr, S.P.R.)
| | - W A Mehan
- From the Departments of Radiology (M.L., K.B., M.D.L., W.A.M., Jr, S.P.R.)
| | - A L Lang
- Anesthesia, Critical Care, and Pain Medicine (A.L.L.)
| | - T M Leslie-Mazwi
- Neurosurgery and Neurology (T.M.L.-M.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - S P Rincon
- From the Departments of Radiology (M.L., K.B., M.D.L., W.A.M., Jr, S.P.R.)
| |
Collapse
|
6
|
Kaelin BR, McKenzie CM, Hempel KW, Lang AL, Arteel GE, Beier JI. Adipose tissue-liver crosstalk during pathologic changes caused by vinyl chloride metabolites in mice. Toxicol Appl Pharmacol 2020; 399:115068. [PMID: 32445754 DOI: 10.1016/j.taap.2020.115068] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/06/2020] [Accepted: 05/19/2020] [Indexed: 12/20/2022]
Abstract
Volatile organic compounds (VOCs), such as vinyl chloride (VC), can be directly toxic at high concentrations. However, we have shown that 'nontoxic' exposures to VC and its metabolite chloroethanol (CE) enhances experimental non-alcoholic fatty liver disease (NAFLD), suggesting an unpredicted interaction. Importantly, VOC exposure has been identified as a potential risk factor for the development of obesity and its sequelae in humans. As there is a known axis between adipose and hepatic tissue in NAFLD, the impact of CE on white adipose tissue (WAT) inflammation and lipolysis was investigated. Mice were administered CE (or vehicle) once, after 10 weeks of being fed high-fat or low-fat diet (LFD). CE significantly enhanced hepatic steatosis and inflammation caused by HFD. HFD significantly increased the size of epididymal fat pads, which was enhanced by CE. The relative size of adipocyte lipid droplets increased by HFD + CE, which was also correlated with increased expression of lipid-associated proteins (e.g., PLINs). CE also enhanced HFD-induced indices of WAT inflammation, and ER stress. Hepatic-derived circulating FGF21, a major modulator of WAT lipolysis, which is hypothesized to thereby regulate hepatic steatosis, was significantly increased by CE in animals fed HFD. Taken together these data support the hypothesis that environmental toxicant exposure can exacerbate the severity of NAFLD/NASH, involving the liver-adipose axis in this process. Specifically, CE enhances local inflammation and alters lipid metabolism and WAT-mediated hepatic steatosis due to changes in WAT lipolysis.
Collapse
Affiliation(s)
- Brenna R Kaelin
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, United States of America; Hepatobiology and Toxicology Program, University of Louisville, Louisville, KY 40292, United States of America.
| | - Collin M McKenzie
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, United States of America; Hepatobiology and Toxicology Program, University of Louisville, Louisville, KY 40292, United States of America.
| | - Karl W Hempel
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, United States of America; Hepatobiology and Toxicology Program, University of Louisville, Louisville, KY 40292, United States of America.
| | - Anna L Lang
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, United States of America; Hepatobiology and Toxicology Program, University of Louisville, Louisville, KY 40292, United States of America.
| | - Gavin E Arteel
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Pittsburgh, Pittsburgh, PA 15213, United States of America; Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA 15213, United States of America.
| | - Juliane I Beier
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Pittsburgh, Pittsburgh, PA 15213, United States of America; Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA 15213, United States of America.
| |
Collapse
|
7
|
Lang AL, Goldsmith WT, Schnegelberger RD, Arteel GE, Beier JI. Vinyl Chloride and High-Fat Diet as a Model of Environment and Obesity Interaction. J Vis Exp 2020. [PMID: 31984951 DOI: 10.3791/60351] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Vinyl chloride (VC), an abundant environmental contaminant, causes steatohepatitis at high levels, but is considered safe at lower levels. Although several studies have investigated the role of VC as a direct hepatotoxicant, the concept that VC modifies sensitivity of the liver to other factors, such as nonalcoholic fatty liver disease (NAFLD) caused by high-fat diet (HFD) is novel. This protocol describes an exposure paradigm to evaluate the effects of chronic, low-level exposure to VC. Mice are acclimated to low-fat or high-fat diet one week prior to the beginning of the inhalation exposure and remain on these diets throughout the experiment. Mice are exposed to VC (sub-OSHA level: <1 ppm) or room air in inhalation chambers for 6 hours/day, 5 days/week, for up to 12 weeks. Animals are monitored weekly for body weight gain and food consumption. This model of VC exposure causes no overt liver injury with VC inhalation alone. However, the combination of VC and HFD significantly enhances liver disease. A technical advantage of this co-exposure model is the whole-body exposure, without restraint. Moreover, the conditions more closely resemble a very common human situation of a combined exposure to VC with underlying nonalcoholic fatty liver disease and therefore support the novel hypothesis that VC is an environmental risk factor for the development of liver damage as a complication of obesity (i.e., NAFLD). This work challenges the paradigm that the current exposure limits of VC (occupational and environmental) are safe. The use of this model can shed new light and concern on the risks of VC exposure. This model of toxicant-induced liver injury can be used for other volatile organic compounds and to study other interactions that may impact the liver and other organ systems.
Collapse
Affiliation(s)
- Anna L Lang
- Department of Pharmacology and Toxicology, University of Louisville; Hepatobiology and Toxicology Program, University of Louisville
| | - William T Goldsmith
- Department of Physiology and Pharmacology, West Virginia University; Center for Inhalation Toxicology, West Virginia University
| | - Regina D Schnegelberger
- Department of Pharmacology and Chemical Biology, University of Pittsburgh; Pittsburgh Liver Research Center, University of Pittsburgh
| | - Gavin E Arteel
- Pittsburgh Liver Research Center, University of Pittsburgh; Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Pittsburgh
| | - Juliane I Beier
- Pittsburgh Liver Research Center, University of Pittsburgh; Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Pittsburgh;
| |
Collapse
|
8
|
Lang AL, Krueger AM, Schnegelberger RD, Kaelin BR, Rakutt MJ, Chen L, Arteel GE, Beier JI. Rapamycin attenuates liver injury caused by vinyl chloride metabolite chloroethanol and lipopolysaccharide in mice. Toxicol Appl Pharmacol 2019; 382:114745. [PMID: 31499194 DOI: 10.1016/j.taap.2019.114745] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/26/2019] [Accepted: 09/04/2019] [Indexed: 01/09/2023]
Abstract
Vinyl chloride (VC) is a prevalent environmental toxicant that is rapidly metabolized within the liver. Its metabolites have been shown to directly cause hepatic injury at high exposure levels. We have previously reported that VC metabolite, chloroethanol (CE), potentiates liver injury caused by lipopolysaccharide (LPS). Importantly, that study showed that CE alone, while not causing damage per se, was sufficient to alter hepatic metabolism and increase mTOR phosphorylation in mice, suggesting a possible role for the mTOR pathway. Here, we explored the effect of an mTOR inhibitor, rapamycin, in this model. C57BL/6 J mice were administered CE, followed by rapamycin 1 h and LPS 24 h later. As observed previously, the combination of CE and LPS significantly enhanced liver injury, inflammation, oxidative stress, and metabolic dysregulation. Rapamycin attenuated not only inflammation, but also restored the metabolic phenotype and protected against CE + LPS-induced oxidative stress. Importantly, rapamycin protected against mitochondrial damage and subsequent production of reactive oxygen species (ROS). The protective effect on mitochondrial function by rapamycin was mediated, by restoring the integrity of the electron transport chain at least in part, by blunting the deactivation of mitochondrial c-src, which is involved mitochondrial ROS production by electron transport chain leakage. Taken together, these results further demonstrate a significant role of mTOR-mediated pathways in VC-metabolite induced liver injury and provide further insight into VC-associated hepatic damage. As mTOR mediated pathways are very complex and rapamycin is a more global inhibitor, more specific mTOR (i.e. mTORC1) inhibitors should be considered in future studies.
Collapse
Affiliation(s)
- Anna L Lang
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, United States of America; Hepatobiology and Toxicology Program, University of Louisville, Louisville, KY 40292, United States of America.
| | - Austin M Krueger
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, United States of America.
| | - Regina D Schnegelberger
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, United States of America; Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA 15213, United States of America.
| | - Brenna R Kaelin
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, United States of America.
| | - Maxwell J Rakutt
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, United States of America.
| | - Liya Chen
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, United States of America; Hepatobiology and Toxicology Program, University of Louisville, Louisville, KY 40292, United States of America.
| | - Gavin E Arteel
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA 15213, United States of America; Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Pittsburgh, Pittsburgh, PA 15213, United States of America.
| | - Juliane I Beier
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA 15213, United States of America; Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Pittsburgh, Pittsburgh, PA 15213, United States of America.
| |
Collapse
|
9
|
Lang AL, Beier JI. Interaction of volatile organic compounds and underlying liver disease: a new paradigm for risk. Biol Chem 2019; 399:1237-1248. [PMID: 29924722 DOI: 10.1515/hsz-2017-0324] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 06/14/2018] [Indexed: 01/07/2023]
Abstract
Occupational and environmental exposures to industrial chemicals are known to cause hepatotoxicity and liver injury, in humans and in animal models. Historically, research has focused on severe acute liver injury (e.g. fulminant liver failure) or endstage diseases (e.g. cirrhosis and HCC). However, it has become recently recognized that toxicants can cause more subtle changes to the liver. For example, toxicant-associated steatohepatitis, characterized by hepatic steatosis, and inflammation, was recently recognized in an occupational cohort exposed to vinyl chloride. At high occupational levels, toxicants are sufficient to cause liver damage and disease even in healthy subjects with no comorbidities for liver injury. However, it is still largely unknown how exposure to toxicants initiate and possibly more importantly exacerbate liver disease, when combined with other factors, such as underlying non-alcoholic fatty liver disease caused by poor diet and/or obesity. With better understanding of the mechanism(s) and risk factors that mediate the initiation and progression of toxicant-induced liver disease, rational targeted therapy can be developed to better predict risk, as well as to treat or prevent this disease. The purpose of this review is to summarize established and proposed mechanisms of volatile organic compound-induced liver injury and to highlight key signaling events known or hypothesized to mediate these effects.
Collapse
Affiliation(s)
- Anna L Lang
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, USA.,Hepatobiology and Toxicology Program, University of Louisville, Louisville, KY 40292, USA.,University of Louisville Alcohol Research Center, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Juliane I Beier
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, USA.,Hepatobiology and Toxicology Program, University of Louisville, Louisville, KY 40292, USA.,University of Louisville Alcohol Research Center, University of Louisville Health Sciences Center, Louisville, KY 40292, USA.,Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| |
Collapse
|
10
|
Chen L, Lang AL, Poff GD, Ding WX, Beier JI. Vinyl chloride-induced interaction of nonalcoholic and toxicant-associated steatohepatitis: Protection by the ALDH2 activator Alda-1. Redox Biol 2019; 24:101205. [PMID: 31026768 PMCID: PMC6479707 DOI: 10.1016/j.redox.2019.101205] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 04/10/2019] [Accepted: 04/14/2019] [Indexed: 12/20/2022] Open
Abstract
Vinyl chloride (VC), an abundant environmental contaminant causes steatohepatitis at high levels, but is considered safe at lower (i.e., sub-OSHA) levels. However, we have previously shown that even lower VC levels exacerbate experimental nonalcoholic fatty liver disease (NAFLD) caused by high-fat diet (HFD). Mitochondrial oxidative injury and subsequent metabolic dysfunction appeared to play key roles in mediating this interaction. Mitochondrial aldehyde dehydrogenase 2 (ALDH2) serves as a key line of defense against endogenous and exogenous reactive aldehydes. The current study therefore tests the hypothesis that allosteric activation of ALDH2 with Alda-1 will protect against VC-enhanced NAFLD. Mice were exposed to low VC concentrations (<1 ppm), or room air for 6 h/day, 5 days/week for 12 weeks, while on HFD or low-fat control diet (LFD). Some mice received Alda-1 (20 mg/kg i.p., 3 × /week) for the last 3 weeks of diet/VC exposure. Indices of liver injury, oxidative stress, metabolic and mitochondrial (dys)function were measured. As observed previously, low-dose VC did not cause liver injury in control mice; while liver injury caused by HFD was enhanced by VC. VC decreased hepatic ALDH2 activity of mice fed HFD. Alda-1 attenuated oxidative stress, liver injury, and dysmetabolism in mice exposed to HFD+VC under these conditions. Importantly, alterations in mitochondrial function caused by VC and HFD were diminished by Alda-1. Previous studies have indicated that liver injury caused by HFD is mediated, at least in part, by enhanced mitochondrial autophagy (mitophagy). Here, Alda-1 suppressed PINK1/PARKIN-mediated mitophagy. Taken together, these results support the hypothesis that ALDH2 is a critical defense against mitochondrial injury caused by VC in experimental NAFLD. The ALDH2 activator Alda-1 conferred protection against liver damage under these conditions, most likely via increasing clearance of aldehydes and preserving mitochondrial respiratory function. VC, combined with HFD impairs ALDH2 function, causing an accumulation of endogenous aldehydes and oxidative stress in vivo. VC metabolite chloroacetaldehyde directly blocks ALDH2 activity in vitro. Alda-1 treatment reverses pre-established liver injury, oxidative stress and metabolic dysregulation caused by VC and HFD. Alda-1 increases overall autophagy caused by VC+HFD, but decreases mitophagy, likely to preserve mitochondrial function.
Collapse
Affiliation(s)
- Liya Chen
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY, 40202, USA; Hepatobiology and Toxicology Program, University of Louisville Health Sciences Center, Louisville, KY, 40202, USA; University of Louisville Alcohol Research Center, University of Louisville Health Sciences Center, Louisville, KY, 40202, USA.
| | - Anna L Lang
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY, 40202, USA; Hepatobiology and Toxicology Program, University of Louisville Health Sciences Center, Louisville, KY, 40202, USA; University of Louisville Alcohol Research Center, University of Louisville Health Sciences Center, Louisville, KY, 40202, USA.
| | - Gavin D Poff
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY, 40202, USA; Hepatobiology and Toxicology Program, University of Louisville Health Sciences Center, Louisville, KY, 40202, USA; University of Louisville Alcohol Research Center, University of Louisville Health Sciences Center, Louisville, KY, 40202, USA.
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, 66160, USA.
| | - Juliane I Beier
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
| |
Collapse
|
11
|
Colter BT, Garber HF, Fleming SM, Fowler JP, Harding GD, Hooven MK, Howes AA, Infante SK, Lang AL, MacDougall MC, Stegman M, Taylor KR, Curran CP. Ahr and Cyp1a2 genotypes both affect susceptibility to motor deficits following gestational and lactational exposure to polychlorinated biphenyls. Neurotoxicology 2019; 65:125-134. [PMID: 29409959 DOI: 10.1016/j.neuro.2018.01.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 01/16/2018] [Accepted: 01/21/2018] [Indexed: 02/04/2023]
Abstract
Polychlorinated biphenyls (PCBs) are persistent organic pollutants known to cause adverse health effects and linked to neurological deficits in both human and animal studies. Children born to exposed mothers are at highest risk of learning and memory and motor deficits. We developed a mouse model that mimics human variation in the aryl hydrocarbon receptor and cytochrome P450 1A2 (CYP1A2) to determine if genetic variation increases susceptibility to developmental PCB exposure. In our previous studies, we found that high-affinity AhrbCyp1a2(-/-) and poor-affinity AhrdCyp1a2(-/-) knockout mice were most susceptible to learning and memory deficits following developmental PCB exposure compared with AhrbCyp1a2(+/+) wild type mice (C57BL/6J strain). Our follow-up studies focused on motor deficits, because human studies have identified PCBs as a potential risk factor for Parkinson's disease. Dams were treated with an environmentally relevant PCB mixture at gestational day 10 and postnatal day 5. We used a motor battery that included tests of nigrostriatal function as well as cerebellar function, because PCBs deplete thyroid hormone, which is essential to normal cerebellar development. There was a significant effect of PCB treatment in the rotarod test with impaired performance in all three genotypes, but decreased motor learning as well in the two Cyp1a2(-/-) knockout lines. Interestingly, we found a main effect of genotype with corn oil-treated control Cyp1a2(-/-) mice performing significantly worse than Cyp1a2(+/+) wild type mice. In contrast, we found that PCB-treated high-affinity Ahrb mice were most susceptible to disruption of nigrostriatal function with the greatest deficits in AhrbCyp1a2(-/-) mice. We conclude that differences in AHR affinity combined with the absence of CYP1A2 protein affect susceptibility to motor deficits following developmental PCB exposure.
Collapse
Affiliation(s)
- Breann T Colter
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Helen Frances Garber
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Sheila M Fleming
- Department of Psychology and Neurology, University of Cincinnati, Cincinnati, OH, 45267, USA
| | - Jocelyn Phillips Fowler
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Gregory D Harding
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Molly Kromme Hooven
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Amy Ashworth Howes
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Smitha Krishnan Infante
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Anna L Lang
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | | | - Melinda Stegman
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Kelsey Rae Taylor
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA
| | - Christine Perdan Curran
- Department of Biological Sciences, Northern Kentucky University, Highland Heights, KY, 41076, USA.
| |
Collapse
|
12
|
Liang Y, Lang AL, Zhang J, Chen J, Wang K, Chen L, Beier JI, Qian Y, Cai L. Exposure to Vinyl Chloride and Its Influence on Western Diet-Induced Cardiac Remodeling. Chem Res Toxicol 2018; 31:482-493. [PMID: 29727174 PMCID: PMC6167925 DOI: 10.1021/acs.chemrestox.8b00043] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [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: 12/11/2022]
Abstract
Obesity, usually caused by high fat diets (HFD), is a major public health issue worldwide, causing obesity associated cardiomyopathy. Moreover, the environmental toxicant vinyl chloride (VC) can exacerbate HFD-induced fatty liver disease. However, whether VC serves to enhance obesity-associated cardiomyopathy remains unclear. This study aims to investigate the interaction of western diet (WD) containing relatively low fat (42%) with VC on cardiac remodeling and its underling mechanisms. Adult male C57BL/6J mice were exposed to WD coinhalation of low-dose VC (<1 ppm/d) for 12 weeks. Results showed that WD feeding for 12 weeks caused slight cardiac systolic dysfunction without significant hypertrophy or fibrosis, even with VC. Nevertheless, WD upregulated NF-κB function and expression of IL-1β and PAI-1, while VC showed no significant impact on these effects. In contrast, WD together with VC significantly increased the expression of CHOP and TGF-β1, key markers for endoplasmic reticulum stress and profibrotic cytokine, respectively. In summary, exposure to low-dose of environmental toxicant VC while a WD is consumed for a relatively short time does not have significant impact on cardiac remodeling except for a mild systolic dysfunction of the heart.
Collapse
Affiliation(s)
- Yaqin Liang
- Department of Pediatrics, First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China
- Department of Pediatrics, Pediatric Research Institute, University of Louisville Alcohol Research Center, University of Louisville, Louisville, Kentucky 40292, United States
| | - Anna L. Lang
- Department of Pharmacology and Toxicology, University of Louisville Alcohol Research Center, University of Louisville, Louisville, Kentucky 40292, United States
- Department of Hepatobiology and Toxicology Program, University of Louisville Alcohol Research Center, University of Louisville, Louisville, Kentucky 40292, United States
| | - Jian Zhang
- Department of Pediatrics, Pediatric Research Institute, University of Louisville Alcohol Research Center, University of Louisville, Louisville, Kentucky 40292, United States
- The Center of Cardiovascular Disorders, The First Hospital of the Jilin University, Changchun 130021, China
| | - Jing Chen
- Department of Pediatrics, Pediatric Research Institute, University of Louisville Alcohol Research Center, University of Louisville, Louisville, Kentucky 40292, United States
| | - Kai Wang
- Department of Pediatrics, First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China
- Department of Pediatrics, Pediatric Research Institute, University of Louisville Alcohol Research Center, University of Louisville, Louisville, Kentucky 40292, United States
| | - Liya Chen
- Department of Pharmacology and Toxicology, University of Louisville Alcohol Research Center, University of Louisville, Louisville, Kentucky 40292, United States
- Department of Hepatobiology and Toxicology Program, University of Louisville Alcohol Research Center, University of Louisville, Louisville, Kentucky 40292, United States
| | - Juliane I. Beier
- Department of Pharmacology and Toxicology, University of Louisville Alcohol Research Center, University of Louisville, Louisville, Kentucky 40292, United States
- Department of Hepatobiology and Toxicology Program, University of Louisville Alcohol Research Center, University of Louisville, Louisville, Kentucky 40292, United States
| | - Yan Qian
- Department of Pediatrics, First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China
| | - Lu Cai
- Department of Pediatrics, Pediatric Research Institute, University of Louisville Alcohol Research Center, University of Louisville, Louisville, Kentucky 40292, United States
- Department of Pharmacology and Toxicology, University of Louisville Alcohol Research Center, University of Louisville, Louisville, Kentucky 40292, United States
- The Center of Cardiovascular Disorders, The First Hospital of the Jilin University, Changchun 130021, China
| |
Collapse
|
13
|
Lang AL, Chen L, Poff GD, Ding WX, Barnett RA, Arteel GE, Beier JI. Vinyl chloride dysregulates metabolic homeostasis and enhances diet-induced liver injury in mice. Hepatol Commun 2018; 2:270-284. [PMID: 29507902 PMCID: PMC5831023 DOI: 10.1002/hep4.1151] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 12/15/2017] [Accepted: 12/31/2017] [Indexed: 12/28/2022] Open
Abstract
Vinyl chloride (VC), a common industrial organochlorine and environmental pollutant, has been shown to directly cause hepatic angiosarcoma and toxicant‐associated steatohepatitis at high exposure levels. However, the impact of lower concentrations of VC on the progression of underlying liver diseases (e.g., nonalcoholic fatty liver disease [NAFLD]) is unclear. Given the high prevalence of NAFLD in the United States (and worldwide) population, this is an important concern. Recent studies by our group with VC metabolites suggest a potential interaction between VC exposure and underlying liver disease to cause enhanced damage. Here, a novel mouse model determined the effects of VC inhalation at levels below the current Occupational Safety and Health Administration limit (<1 ppm) in the context of NAFLD to better mimic human exposure and identify potential mechanisms of VC‐induced liver injury. VC exposure caused no overt liver injury in mice fed a low‐fat diet. However, in mice fed a high‐fat diet (HFD), VC significantly increased liver damage, steatosis, and increased neutrophil infiltration. Moreover, VC further enhanced HFD‐induced oxidative and endoplasmic reticulum stress. Importantly, VC exposure dysregulated energy homeostasis and impaired mitochondrial function, even in mice fed a low‐fat diet. In toto, the results indicate that VC exposure causes metabolic stress that sensitizes the liver to steatohepatitis caused by HFD. Conclusion: The hypothesis that low‐level (below the Occupational Safety and Health Administration limit) chronic exposure to VC by inhalation enhances liver injury caused by an HFD is supported. Importantly, our data raise concerns about the potential for overlap between fatty diets (i.e., Western diet) and exposure to VC and the health implications of this co‐exposure for humans. It also emphasizes that current safety restrictions may be insufficient to account for other factors that can influence hepatotoxicity. (Hepatology Communications 2018;2:270‐284)
Collapse
Affiliation(s)
- Anna L Lang
- Department of Pharmacology and Toxicology University of Louisville Health Sciences Center Louisville KY.,Hepatobiology and Toxicology Program University of Louisville Health Sciences Center Louisville KY.,University of Louisville Alcohol Research Center University of Louisville Health Sciences Center Louisville KY
| | - Liya Chen
- Department of Pharmacology and Toxicology University of Louisville Health Sciences Center Louisville KY.,Hepatobiology and Toxicology Program University of Louisville Health Sciences Center Louisville KY.,University of Louisville Alcohol Research Center University of Louisville Health Sciences Center Louisville KY
| | - Gavin D Poff
- Department of Pharmacology and Toxicology University of Louisville Health Sciences Center Louisville KY.,Hepatobiology and Toxicology Program University of Louisville Health Sciences Center Louisville KY
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics University of Kansas Medical Center Kansas City KS
| | - Russel A Barnett
- Kentucky Institute for the Environment and Sustainable Development University of Louisville Louisville KY
| | - Gavin E Arteel
- Department of Pharmacology and Toxicology University of Louisville Health Sciences Center Louisville KY.,Hepatobiology and Toxicology Program University of Louisville Health Sciences Center Louisville KY.,University of Louisville Alcohol Research Center University of Louisville Health Sciences Center Louisville KY
| | - Juliane I Beier
- Department of Pharmacology and Toxicology University of Louisville Health Sciences Center Louisville KY.,Hepatobiology and Toxicology Program University of Louisville Health Sciences Center Louisville KY.,University of Louisville Alcohol Research Center University of Louisville Health Sciences Center Louisville KY
| |
Collapse
|
14
|
Schaefer TL, Davenport MH, Grainger LM, Robinson CK, Earnheart AT, Stegman MS, Lang AL, Ashworth AA, Molinaro G, Huber KM, Erickson CA. Acamprosate in a mouse model of fragile X syndrome: modulation of spontaneous cortical activity, ERK1/2 activation, locomotor behavior, and anxiety. J Neurodev Disord 2017; 9:6. [PMID: 28616095 PMCID: PMC5467053 DOI: 10.1186/s11689-017-9184-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 01/13/2017] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Fragile X Syndrome (FXS) occurs as a result of a silenced fragile X mental retardation 1 gene (FMR1) and subsequent loss of fragile X mental retardation protein (FMRP) expression. Loss of FMRP alters excitatory/inhibitory signaling balance, leading to increased neuronal hyperexcitability and altered behavior. Acamprosate (the calcium salt of N-acetylhomotaurinate), a drug FDA-approved for relapse prevention in the treatment of alcohol dependence in adults, is a novel agent with multiple mechanisms that may be beneficial for people with FXS. There are questions regarding the neuroactive effects of acamprosate and the significance of the molecule's calcium moiety. Therefore, the electrophysiological, cellular, molecular, and behavioral effects of acamprosate were assessed in the Fmr1-/y (knock out; KO) mouse model of FXS controlling for the calcium salt in several experiments. METHODS Fmr1 KO mice and their wild-type (WT) littermates were utilized to assess acamprosate treatment on cortical UP state parameters, dendritic spine density, and seizure susceptibility. Brain extracellular-signal regulated kinase 1/2 (ERK1/2) activation was used to investigate this signaling molecule as a potential biomarker for treatment response. Additional adult mice were used to assess chronic acamprosate treatment and any potential effects of the calcium moiety using CaCl2 treatment on behavior and nuclear ERK1/2 activation. RESULTS Acamprosate attenuated prolonged cortical UP state duration, decreased elevated ERK1/2 activation in brain tissue, and reduced nuclear ERK1/2 activation in the dentate gyrus in KO mice. Acamprosate treatment modified behavior in anxiety and locomotor tests in Fmr1 KO mice in which control-treated KO mice were shown to deviate from control-treated WT mice. Mice treated with CaCl2 were not different from saline-treated mice in the adult behavior battery or nuclear ERK1/2 activation. CONCLUSIONS These data indicate that acamprosate, and not calcium, improves function reminiscent of reduced anxiety-like behavior and hyperactivity in Fmr1 KO mice and that acamprosate attenuates select electrophysiological and molecular dysregulation that may play a role in the pathophysiology of FXS. Differences between control-treated KO and WT mice were not evident in a recognition memory test or in examination of acoustic startle response/prepulse inhibition which impeded conclusions from being made about the treatment effects of acamprosate in these instances.
Collapse
Affiliation(s)
- Tori L Schaefer
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| | - Matthew H Davenport
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| | - Lindsay M Grainger
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| | - Chandler K Robinson
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| | - Anthony T Earnheart
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| | - Melinda S Stegman
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA.,Present address: Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229 USA
| | - Anna L Lang
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA.,Present address: Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40202 USA
| | - Amy A Ashworth
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA.,Present address: BlackbookHR, Cincinnati, OH 45202 USA
| | - Gemma Molinaro
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Kimberly M Huber
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Craig A Erickson
- Division of Psychiatry, MLC 7004, Cincinnati Children's Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229-3039 USA
| |
Collapse
|
15
|
Anders LC, Yeo H, Kaelin BR, Lang AL, Bushau AM, Douglas AN, Cave M, Arteel GE, McClain CJ, Beier JI. Role of dietary fatty acids in liver injury caused by vinyl chloride metabolites in mice. Toxicol Appl Pharmacol 2016; 311:34-41. [PMID: 27693805 DOI: 10.1016/j.taap.2016.09.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 09/24/2016] [Accepted: 09/27/2016] [Indexed: 02/09/2023]
Abstract
BACKGROUND Vinyl chloride (VC) causes toxicant-associated steatohepatitis at high exposure levels. Recent work by this group suggests that underlying liver disease may predispose the liver to VC hepatotoxicity at lower exposure levels. The most common form of underlying liver disease in the developed world is non-alcoholic fatty liver disease (NAFLD). It is well-known that the type of dietary fat can play an important role in the pathogenesis of NAFLD. However, whether the combination of dietary fat and VC/metabolites promotes liver injury has not been studied. METHODS Mice were administered chloroethanol (CE - a VC metabolite) or vehicle once, 10weeks after being fed diets rich in saturated fatty acids (HSFA), rich in poly-unsaturated fatty acids (HPUFA), or the respective low-fat control diets (LSFA; LPUFA). RESULTS In control mice, chloroethanol caused no detectable liver injury, as determined by plasma transaminases and histologic indices of damage. In HSFA-fed mice, chloroethanol increased HSFA-induced liver damage, steatosis, infiltrating inflammatory cells, hepatic expression of proinflammatory cytokines, and markers of endoplasmic reticulum (ER) stress. Moreover, markers of inflammasome activation were increased, while markers of inflammasome inhibition were downregulated. In mice fed HPUFA all of these effects were significantly attenuated. CONCLUSIONS Chloroethanol promotes inflammatory liver injury caused by dietary fatty acids. This effect is far more exacerbated with saturated fat, versus poly-unsaturated fat; and strongly correlates with a robust activation of the NLRP3 inflammasome in the saturated fed animals only. Taken together these data support the hypothesis that environmental toxicant exposure can exacerbate the severity of NAFLD/NASH.
Collapse
Affiliation(s)
- Lisanne C Anders
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Department of Medicine, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Heegook Yeo
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Brenna R Kaelin
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Anna L Lang
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Adrienne M Bushau
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Amanda N Douglas
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Matt Cave
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Department of Medicine, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Hepatobiology and Toxicology Program, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Diabetes and Obesity Center, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Robley Rex Louisville VAMC, Louisville, KY 40206, USA
| | - Gavin E Arteel
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Hepatobiology and Toxicology Program, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Craig J McClain
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Department of Medicine, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Hepatobiology and Toxicology Program, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Diabetes and Obesity Center, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Robley Rex Louisville VAMC, Louisville, KY 40206, USA
| | - Juliane I Beier
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Hepatobiology and Toxicology Program, University of Louisville Health Sciences Center, Louisville, KY 40292, USA.
| |
Collapse
|
16
|
Anders LC, Lang AL, Anwar-Mohamed A, Douglas AN, Bushau AM, Falkner KC, Hill BG, Warner NL, Arteel GE, Cave M, McClain CJ, Beier JI. Vinyl Chloride Metabolites Potentiate Inflammatory Liver Injury Caused by LPS in Mice. Toxicol Sci 2016; 151:312-23. [PMID: 26962056 DOI: 10.1093/toxsci/kfw045] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Vinyl chloride (VC) is a ubiquitous environmental contaminant for which human risk is incompletely understood. We have previously reported that high occupational exposure to VC directly caused liver damage in humans. However, whether VC may also potentiate liver injury from other causes is not known. C57Bl/6J mice were administered chloroethanol (CE), a major metabolite of VC, and lipopolysaccharide (LPS) 24 h after CE. Samples were harvested for determination of liver damage, inflammation, and changes in carbohydrate and lipid metabolism. In mice, CE exposure alone caused no detectable liver damage. LPS exposure caused inflammatory liver damage, oxidative stress, lipid accumulation, and glycogen depletion; the effect of all of these variables was potentiated by CE pre-exposure. In vitro experiments suggest that VC metabolite chloroacetaldehyde (CAA) directly damages mitochondria, which may explain the sensitization effect observed in vivo Moreover, co-exposure of cells to CAA and TNFα caused increased cell death, supporting the hypothesis of sensitization by VC metabolites. Taken together, these data demonstrate that exposure to VC/metabolites at levels that are not overtly hepatotoxic can potentiate liver injury caused by another hepatotoxicant. This serves as proof-of-concept that VC hepatotoxicity may be modified by an additional metabolic stress such as endotoxemia, which commonly occurs in acute (eg, sepsis) and chronic (eg, NAFLD) diseases.
Collapse
Affiliation(s)
- Lisanne C Anders
- *Department of Pharmacology and Toxicology Department of Medicine
| | | | | | | | | | | | | | - Nikole L Warner
- Department of Microbiology and Immunology, University of Louisville Health Sciences Center, Louisville, Kentucky 40292; and
| | | | - Matt Cave
- *Department of Pharmacology and Toxicology Department of Medicine Robley Rex Louisville VAMC, Louisville, Kentucky 40206
| | - Craig J McClain
- *Department of Pharmacology and Toxicology Department of Medicine Robley Rex Louisville VAMC, Louisville, Kentucky 40206
| | | |
Collapse
|
17
|
Abstract
OBJECTIVE Today's medical school graduates have significant deficits in physical examination skills. Medical educators have been searching for methods to effectively teach and maintain these skills in students. The objective of this study was to determine if an auscultation curriculum centered on a portable multimedia CD-ROM was effective in producing and maintaining significant gains in cardiac auscultatory skills. DESIGN Controlled cohort study. PARTICIPANTS All 168 third-year medical students at 1 medical school in an academic medical center. INTERVENTIONS Students were tested before and after exposure to 1 or more elements of the auscultation curriculum: teaching on ward/clinic rotations, CD-ROM comprehensive cases with follow-up seminars, and a CD-ROM 20-case miniseries. The primary outcome measures were student performance on a 10-item test of auscultation skill (listening and identifying heart sound characteristics) and a 30-item test of auscultation knowledge (factual questions about auscultation). A subset of students was tested for attenuation effects 9 or 12 months after the intervention. RESULTS Compared with the control group (1 month clinical rotation alone), students who were also exposed to the CD-ROM 20-case miniseries had significant improvements in auscultation skills scores (P < .05), but not knowledge. Additional months of clerkship, comprehensive CD-ROM cases, and follow-up seminars increased auscultation knowledge beyond the miniseries alone (P < .05), but did not further improve auscultation skills. Students' auscultation knowledge diminished one year after the intervention, but auscultation skills did not. CONCLUSION In addition to the standard curriculum of ward and conference teaching, portable multimedia tools may help improve quality of physical examination skills.
Collapse
Affiliation(s)
- D T Stern
- Department of Internal Medicine, VA Ann Arbor Healthcare System, Ann Arbor, Mich., USA.
| | | | | | | | | | | |
Collapse
|
18
|
Lang AL, Tsai YL, Mayer CL, Patton KC, Palmer CJ. Multiplex PCR for detection of the heat-labile toxin gene and shiga-like toxin I and II genes in Escherichia coli isolated from natural waters. Appl Environ Microbiol 1994; 60:3145-9. [PMID: 7944359 PMCID: PMC201782 DOI: 10.1128/aem.60.9.3145-3149.1994] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [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: 01/28/2023] Open
Abstract
A triplex PCR method was developed to simultaneously amplify a heat-labile toxin sequence (LT) of 258 bp, a shiga-like toxin I sequence (SLT I) of 130 bp, and a shiga-like toxin II sequence (SLT II) of 346 bp from toxigenic strains of Escherichia coli. This method was used to screen 377 environmental E. coli isolates from marine waters or estuaries located in Southern California and North Carolina for enterotoxigenic or enterohemorrhagic E. coli strains. Of the 377 E. coli screened, one isolate was found to belong to the enterotoxigenic group, since it contained a LT homologous sequence, and one isolate was found to belong to the enterohemorrhagic group, since it contained a SLT I homologous sequence. None was found to contain SLT II homologous sequences. The pathogenicity of the positive environmental E. coli isolates was confirmed by standard bioassays with Y-1 adrenal cells and Vero cells to confirm toxin production. Our results suggest that toxigenic E. coli occurs infrequently in environmental waters and that there is a low public health risk from toxigenic E. coli in coastal waters.
Collapse
Affiliation(s)
- A L Lang
- Environmental Sciences Laboratory, County Sanitation Districts of Orange County, Fountain Valley, California 92728-8127
| | | | | | | | | |
Collapse
|
19
|
Palmer CJ, Tsai YL, Lang AL, Sangermano LR. Evaluation of colilert-marine water for detection of total coliforms and Escherichia coli in the marine environment. Appl Environ Microbiol 1993; 59:786-90. [PMID: 8481005 PMCID: PMC202190 DOI: 10.1128/aem.59.3.786-790.1993] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [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: 01/31/2023] Open
Abstract
A test that allows for early detection of fecally contaminated coastal water would enhance public health protection. Colilert-Marine Water (Colilert-MW; Environetics, Branford, Conn.) is a rapid 24-h test that has recently been developed to detect total coliforms and Escherichia coli in coastal water. We performed a premarketing evaluation of the Colilert-MW product, testing it in parallel with the multiple tube fermentation (MTF) method for 86 coastal water samples in southern California. Statistical analysis was performed by using paired t tests and linear regression. Bacterial isolates were evaluated by biochemical and genetic analysis. The results of this study showed a strong correlation between the traditional MTF and the Colilert-MW method for detection of total coliforms (r = 0.95) and E. coli (r = 0.89) in ocean water samples. Paired t-test results indicated that the Colilert-MW and MTF were equivalent in detecting E. coli and that the Colilert-MW may be more sensitive in the detection of total coliforms. We conclude that Colilert-MW would be a useful tool with which to monitor coastal beach water.
Collapse
Affiliation(s)
- C J Palmer
- County Sanitation Districts of Orange County, Fountain Valley, California 92728-8127
| | | | | | | |
Collapse
|
20
|
Abstract
Sulfate translocation in soybean (Glycine max L. Merr) was investigated. More than 90% of the sulfate entering the shoot system was recoverable in one or two developing trifoliate leaves. In young plants, the first trifoliate leaf contained between 10 to 20 times as much sulfate as the primary leaves, even though both types of leaf had similar rates of transpiration and photosynthesis. We conclude that most of the sulfate entering mature leaves is rapidly loaded into the phloem and translocated to sinks elsewhere in the plant. This loading was inhibited by carbonylcyanide m-chlorophenylhydrazone and selenate. At sulfate concentrations below 0.1 millimolar, more than 95% of the sulfate entering primary leaves was exported. At higher concentrations the rate of export increased but so did the amount of sulfate remaining in the leaves. Removal of the first trifoliate leaf increased two-fold the transport of sulfate to the apex, indicating that these are competing sinks for sulfate translocated from the primary leaves. The small amount of sulfate transported into the mesophyll cells of primary leaves is a result of feedback regulation by the intracellular sulfate pool, not a consequence of their metabolic inactivity. For example, treatment of plants with 2 millimolar aminotriazole caused a 700 nanomoles per gram fresh weight increase in the glutathione content of primary leaves, but had no effect on sulfate aquisition.
Collapse
Affiliation(s)
- I K Smith
- Department of Botany, Ohio University, Athens, Ohio 45701
| | | |
Collapse
|
21
|
Abstract
A method is described for the decoloration and partial solubilization of plant tissue with 2% sodium hypochlorite. Following treatment of the digest with ammonia, the samples are suitable for the determination of 3H, 14C, and 35S by liquid scintillation counting. The color quenching is negligible and counting efficiencies are high: 30-40% for 3H and 90-95% for 14C.
Collapse
Affiliation(s)
- I K Smith
- Department of Botany, Ohio University, Athens 45701
| | | |
Collapse
|