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Krasner A, Stolen M, Rotstein D, Fire S. Contaminant Exposure and Liver and Kidney Lesions in North American River Otters in the Indian River Lagoon, Florida. TOXICS 2024; 12:684. [PMID: 39330612 PMCID: PMC11435442 DOI: 10.3390/toxics12090684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Revised: 09/11/2024] [Accepted: 09/18/2024] [Indexed: 09/28/2024]
Abstract
The harmful algal bloom (HAB) liver toxin microcystin (MC) and trace element biomagnification were previously detected in organisms in the Indian River Lagoon (IRL), Florida. Since there are no routine screening programs for these contaminants, liver tissue from North American river otters (Lontra canadensis), an important sentinel species in the IRL, was screened for MC via enzyme-linked immunoassay (ELISA), followed by confirmatory analyses via liquid-chromatography/mass spectrometry methods (LC-MS/MS). Liver and kidney samples were evaluated for trace element (As, Cd, Co, Cu, Fe, Hg, Mn, Mo, Pb, Se, Tl, and Zn) bioaccumulation via inductively coupled plasma mass spectrometry (ICP-MS). Histopathologic evaluation of the liver and kidney was conducted to assess possible correlation with toxic insults. Forty-three river otters were evaluated (2016-2022). Microcystin was not detected in any river otter sample (n = 37). Of those tested for trace element bioaccumulation (n = 22), no sample measured above provided reference ranges or estimated toxic thresholds for this species. There were no statistically significant patterns observed based on season, year, or age class, but sex had a small influence on trace element levels in the kidney. One individual had a kidney Cu level (52 μg/g dry weight) higher than any previously reported for this species. Trace elements were detected at presumed background levels providing baselines for future monitoring. For otters with available histopathologic evaluation (n = 28), anomalies indicative of contaminant exposure (non-specific inflammation, necrosis, and/or lipidosis) were present in the liver and kidney of 18% and 4% of individuals, respectively. However, since these lesions were not linked to abnormal trace element bioaccumulation or MC exposure, other causes (e.g., infectious disease) should be considered.
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Affiliation(s)
- Ami Krasner
- Department of Biological Sciences, Florida Institute of Technology, Melbourne, FL 32901, USA
| | - Megan Stolen
- Blue World Research Institute, Cocoa, FL 32927, USA
| | | | - Spencer Fire
- Department of Biological Sciences, Florida Institute of Technology, Melbourne, FL 32901, USA
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Bechtold BJ, Lynch KD, Oyanna VO, Call MR, White LA, Graf TN, Oberlies NH, Clarke JD. Pharmacokinetic Effects of Different Models of Nonalcoholic Fatty Liver Disease in Transgenic Humanized OATP1B Mice. Drug Metab Dispos 2024; 52:355-367. [PMID: 38485280 PMCID: PMC11023818 DOI: 10.1124/dmd.123.001607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 03/05/2024] [Accepted: 03/07/2023] [Indexed: 03/21/2024] Open
Abstract
Organic anion transporting polypeptide (OATP) 1B1 and OATP1B3 (collectively, OATP1B) transporters encoded by the solute carrier organic anion transporter (SLCO) genes mediate uptake of multiple pharmaceutical compounds. Nonalcoholic steatohepatitis (NASH), a severe form of nonalcoholic fatty liver disease (NAFLD), decreases OATP1B abundance. This research characterized the pathologic and pharmacokinetics effects of three diet- and one chemical-induced NAFLD model in male and female humanized OATP1B mice, which comprises knock-out of rodent Oatp orthologs and insertion of human SLCO1B1 and SLCO1B3. Histopathology scoring demonstrated elevated steatosis and inflammation scores for all NAFLD-treatment groups. Female mice had minor changes in SLCO1B1 expression in two of the four NAFLD treatment groups, and pitavastatin (PIT) area under the concentration-time curve (AUC) increased in female mice in only one of the diet-induced models. OATP1B3 expression decreased in male and female mice in the chemical-induced NAFLD model, with a coinciding increase in PIT AUC, indicating the chemical-induced model may better replicate changes in OATP1B3 expression and OATP substrate disposition observed in NASH patients. This research also tested a reported multifactorial pharmacokinetic interaction between NAFLD and silymarin, an extract from milk thistle seeds with notable OATP-inhibitory effects. Males showed no change in PIT AUC, whereas female PIT AUC increased 1.55-fold from the diet alone and the 1.88-fold from the combination of diet with silymarin, suggesting that female mice are more sensitive to pharmacokinetic changes than male mice. Overall, the humanized OATP1B model should be used with caution for modeling NAFLD and multifactorial pharmacokinetic interactions. SIGNIFICANCE STATEMENT: Advanced stages of NAFLD cause decreased hepatic OATP1B abundance and increase systemic exposure to OATP substrates in human patients. The humanized OATP1B mouse strain may provide a clinically relevant model to recapitulate these observations and predict pharmacokinetic interactions in NAFLD. This research characterized three diet-induced and one drug-induced NAFLD model in a humanized OATP1B mouse model. Additionally, a multifactorial pharmacokinetic interaction was observed between silymarin and NAFLD.
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Affiliation(s)
- Baron J Bechtold
- Department of Pharmaceutical Sciences (B.J.B., K.D.L., V.O.O., M.R.C., J.D.C.) and Washington Animal Disease Diagnostic Laboratory (L.A.W.), Washington State University, Pullman, Washington; and Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina (T.N.G., N.H.O.)
| | - Katherine D Lynch
- Department of Pharmaceutical Sciences (B.J.B., K.D.L., V.O.O., M.R.C., J.D.C.) and Washington Animal Disease Diagnostic Laboratory (L.A.W.), Washington State University, Pullman, Washington; and Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina (T.N.G., N.H.O.)
| | - Victoria O Oyanna
- Department of Pharmaceutical Sciences (B.J.B., K.D.L., V.O.O., M.R.C., J.D.C.) and Washington Animal Disease Diagnostic Laboratory (L.A.W.), Washington State University, Pullman, Washington; and Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina (T.N.G., N.H.O.)
| | - M Ridge Call
- Department of Pharmaceutical Sciences (B.J.B., K.D.L., V.O.O., M.R.C., J.D.C.) and Washington Animal Disease Diagnostic Laboratory (L.A.W.), Washington State University, Pullman, Washington; and Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina (T.N.G., N.H.O.)
| | - Laura A White
- Department of Pharmaceutical Sciences (B.J.B., K.D.L., V.O.O., M.R.C., J.D.C.) and Washington Animal Disease Diagnostic Laboratory (L.A.W.), Washington State University, Pullman, Washington; and Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina (T.N.G., N.H.O.)
| | - Tyler N Graf
- Department of Pharmaceutical Sciences (B.J.B., K.D.L., V.O.O., M.R.C., J.D.C.) and Washington Animal Disease Diagnostic Laboratory (L.A.W.), Washington State University, Pullman, Washington; and Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina (T.N.G., N.H.O.)
| | - Nicholas H Oberlies
- Department of Pharmaceutical Sciences (B.J.B., K.D.L., V.O.O., M.R.C., J.D.C.) and Washington Animal Disease Diagnostic Laboratory (L.A.W.), Washington State University, Pullman, Washington; and Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina (T.N.G., N.H.O.)
| | - John D Clarke
- Department of Pharmaceutical Sciences (B.J.B., K.D.L., V.O.O., M.R.C., J.D.C.) and Washington Animal Disease Diagnostic Laboratory (L.A.W.), Washington State University, Pullman, Washington; and Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina (T.N.G., N.H.O.)
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Dolce A, Della Torre S. Sex, Nutrition, and NAFLD: Relevance of Environmental Pollution. Nutrients 2023; 15:nu15102335. [PMID: 37242221 DOI: 10.3390/nu15102335] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/12/2023] [Accepted: 05/13/2023] [Indexed: 05/28/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease and represents an increasing public health issue given the limited treatment options and its association with several other metabolic and inflammatory disorders. The epidemic, still growing prevalence of NAFLD worldwide cannot be merely explained by changes in diet and lifestyle that occurred in the last few decades, nor from their association with genetic and epigenetic risk factors. It is conceivable that environmental pollutants, which act as endocrine and metabolic disruptors, may contribute to the spreading of this pathology due to their ability to enter the food chain and be ingested through contaminated food and water. Given the strict interplay between nutrients and the regulation of hepatic metabolism and reproductive functions in females, pollutant-induced metabolic dysfunctions may be of particular relevance for the female liver, dampening sex differences in NAFLD prevalence. Dietary intake of environmental pollutants can be particularly detrimental during gestation, when endocrine-disrupting chemicals may interfere with the programming of liver metabolism, accounting for the developmental origin of NAFLD in offspring. This review summarizes cause-effect evidence between environmental pollutants and increased incidence of NAFLD and emphasizes the need for further studies in this field.
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Affiliation(s)
- Arianna Dolce
- Department of Pharmaceutical Sciences, University of Milan, 20133 Milan, Italy
| | - Sara Della Torre
- Department of Pharmaceutical Sciences, University of Milan, 20133 Milan, Italy
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Hernandez BY, Zhu X, Nagata M, Loo L, Chan O, Wong LL. Cyanotoxin exposure and hepatocellular carcinoma. Toxicology 2023; 487:153470. [PMID: 36863303 PMCID: PMC10358828 DOI: 10.1016/j.tox.2023.153470] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 02/20/2023] [Accepted: 02/27/2023] [Indexed: 03/04/2023]
Abstract
Cyanobacteria are ubiquitous in aquatic and terrestrial environments worldwide and include a number of species producing tumor-promoting hepatotoxins. Human exposure to cyanobacteria and cyanotoxins primarily occurs though ingestion of contaminated drinking water and food sources. In a Northeast U.S. population, we recently reported an independent association of oral cyanobacteria with risk of hepatocellular carcinoma (HCC). In a cross-sectional study of 55 HCC patients in Hawaii, U.S.A., serum microcystin/nodularin (MC/NOD), cylindrospermopsin (CYN), and anabaenopeptin (AB) were measured by ELISA. In a subset of 16 patients, cyanotoxin levels were compared by tumor expression of over 700 genes analyzed via the Nanostring nCounter Fibrosis panel. MC/NOD, CYN, and AB were detected in all HCC patients. MC/NOD and CYN levels significantly varied by etiology with the highest levels in cases attributed to metabolic risk factors, specifically, hyperlipidemia, type 2 diabetes, and non-alcoholic fatty liver disease/non-alcoholic steatohepatitis. Cyanotoxin levels were significantly positively correlated with tumor expression of genes functioning in PPAR signaling and lipid metabolism. Our study provides novel albeit limited evidence that cyanotoxins may a role in the pathogenesis of HCC through the dysregulation of lipid metabolism and progression of hepatic steatosis.
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Affiliation(s)
- Brenda Y Hernandez
- University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, United States.
| | - Xuemei Zhu
- University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, United States
| | - Michelle Nagata
- University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, United States
| | - Lenora Loo
- University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, United States
| | - O Chan
- University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, United States
| | - Linda L Wong
- University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI, United States
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Antioxidant Therapy Significantly Attenuates Hepatotoxicity following Low Dose Exposure to Microcystin-LR in a Murine Model of Diet-Induced Non-Alcoholic Fatty Liver Disease. Antioxidants (Basel) 2022; 11:antiox11081625. [PMID: 36009344 PMCID: PMC9404967 DOI: 10.3390/antiox11081625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/13/2022] [Accepted: 08/17/2022] [Indexed: 12/15/2022] Open
Abstract
We have previously shown in a murine model of Non-alcoholic Fatty Liver Disease (NAFLD) that chronic, low-dose exposure to the Harmful Algal Bloom cyanotoxin microcystin-LR (MC-LR), resulted in significant hepatotoxicity including micro-vesicular lipid accumulation, impaired toxin metabolism as well as dysregulation of the key signaling pathways involved in inflammation, immune response and oxidative stress. On this background we hypothesized that augmentation of hepatic drug metabolism pathways with targeted antioxidant therapies would improve MC-LR metabolism and reduce hepatic injury in NAFLD mice exposed to MC-LR. We chose N-acetylcysteine (NAC, 40 mM), a known antioxidant that augments the glutathione detoxification pathway and a novel peptide (pNaKtide, 25 mg/kg) which is targeted to interrupting a specific Src-kinase mediated pro-oxidant amplification mechanism. Histological analysis showed significant increase in hepatic inflammation in NAFLD mice exposed to MC-LR which was attenuated on treatment with both NAC and pNaKtide (both p ≤ 0.05). Oxidative stress, as measured by 8-OHDG levels in urine and protein carbonylation in liver sections, was also significantly downregulated upon treatment with both antioxidants after MC-LR exposure. Genetic analysis of key drug transporters including Abcb1a, Phase I enzyme-Cyp3a11 and Phase II metabolic enzymes-Pkm (Pyruvate kinase, muscle), Pklr (Pyruvate kinase, liver, and red blood cell) and Gad1 (Glutamic acid decarboxylase) was significantly altered by MC-LR exposure as compared to the non-exposed control group (all p ≤ 0.05). These changes were significantly attenuated with both pNaKtide and NAC treatment. These results suggest that MC-LR metabolism and detoxification is significantly impaired in the setting of NAFLD, and that these pathways can potentially be reversed with targeted antioxidant treatment.
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Hernandez BY, Biggs J, Zhu X, Sotto P, Nagata M, Mendez AJP, Paulino Y. Environmental Exposure to Cyanobacteria Hepatotoxins in a Pacific Island Community: A Cross-Sectional Assessment. Microorganisms 2022; 10:1607. [PMID: 36014026 PMCID: PMC9412653 DOI: 10.3390/microorganisms10081607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 08/05/2022] [Accepted: 08/06/2022] [Indexed: 12/03/2022] Open
Abstract
(1) Background: Cyanobacteria produce a wide range of secondary metabolites, including tumor-promoting hepatotoxins. We recently reported evidence of an independent association between oral cyanobacteria and hepatocellular carcinoma in a U.S. population. We sought to characterize the nature, sources, and health correlates of cyanotoxin exposure in the U.S. Pacific Island territory of Guam, which has a high incidence of liver cancer. (2) Methods: Seventy-four adult males and females were enrolled in a cross-sectional study to quantify cyanotoxins in saliva, urine, and blood and their correlation with health behaviors, medical history, and environmental exposures. Plant samples were collected from locations throughout the island. Microcystin/nodularin (MC/NOD), cylindrospermopsin (CYN), and anabaenopeptin (AB) were measured in biospecimens and in plant extracts by ELISA. (3) Results: Overall, among study participants MC/NOD were detected in 53.9% of saliva, 7.5% of urine, and 100% of serum.; CYN in 40.0% of saliva, 100.0% of urine, and 70.4% of serum; AB in 30.8% of saliva, 85% of urine, and 92.6% of serum. Salivary MC/NOD levels were significantly higher in individuals using municipal tap water as their primary source of drinking water; both salivary and urinary MC/NOD levels were higher in those not using store-bought/commercial water. Urine MC/NOD levels were highest among individuals consuming fruits and vegetables exclusively from local sources. Urine MC/NOD levels were elevated in individuals with hypertension and hyperlipidemia and salivary MC/NOD in those with recent alcohol consumption. Cyanotoxins were prevalent in plant samples including MC/NOD (46.6%), CYN (35.1%), and AB (51.7%). (4) Conclusions: Our study provides evidence that exposure to cyanobacterial hepatotoxins, including tumor promoters, may be prevalent in Guam and may originate from environmental sources. Population-based epidemiologic studies are needed to investigate the role of cyanotoxins in liver cancer development.
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Affiliation(s)
- Brenda Y. Hernandez
- University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI 96813, USA
| | - Jason Biggs
- University of Guam Cancer Research Center, Mangilao, GU 96913, USA
| | - Xuemei Zhu
- University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI 96813, USA
| | - Patrick Sotto
- University of Guam Cancer Research Center, Mangilao, GU 96913, USA
| | - Michelle Nagata
- University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI 96813, USA
| | | | - Yvette Paulino
- University of Guam Cancer Research Center, Mangilao, GU 96913, USA
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Lad A, Breidenbach JD, Su RC, Murray J, Kuang R, Mascarenhas A, Najjar J, Patel S, Hegde P, Youssef M, Breuler J, Kleinhenz AL, Ault AP, Westrick JA, Modyanov NN, Kennedy DJ, Haller ST. As We Drink and Breathe: Adverse Health Effects of Microcystins and Other Harmful Algal Bloom Toxins in the Liver, Gut, Lungs and Beyond. Life (Basel) 2022; 12:life12030418. [PMID: 35330169 PMCID: PMC8950847 DOI: 10.3390/life12030418] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 03/03/2022] [Accepted: 03/08/2022] [Indexed: 12/19/2022] Open
Abstract
Freshwater harmful algal blooms (HABs) are increasing in number and severity worldwide. These HABs are chiefly composed of one or more species of cyanobacteria, also known as blue-green algae, such as Microcystis and Anabaena. Numerous HAB cyanobacterial species produce toxins (e.g., microcystin and anatoxin—collectively referred to as HAB toxins) that disrupt ecosystems, impact water and air quality, and deter recreation because they are harmful to both human and animal health. Exposure to these toxins can occur through ingestion, inhalation, or skin contact. Acute health effects of HAB toxins have been well documented and include symptoms such as nausea, vomiting, abdominal pain and diarrhea, headache, fever, and skin rashes. While these adverse effects typically increase with amount, duration, and frequency of exposure, susceptibility to HAB toxins may also be increased by the presence of comorbidities. The emerging science on potential long-term or chronic effects of HAB toxins with a particular emphasis on microcystins, especially in vulnerable populations such as those with pre-existing liver or gastrointestinal disease, is summarized herein. This review suggests additional research is needed to define at-risk populations who may be helped by preventative measures. Furthermore, studies are required to develop a mechanistic understanding of chronic, low-dose exposure to HAB toxins so that appropriate preventative, diagnostic, and therapeutic strategies can be created in a targeted fashion.
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Affiliation(s)
- Apurva Lad
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
| | - Joshua D. Breidenbach
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
| | - Robin C. Su
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
| | - Jordan Murray
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
| | - Rebecca Kuang
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
| | - Alison Mascarenhas
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
| | - John Najjar
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
| | - Shivani Patel
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
| | - Prajwal Hegde
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
| | - Mirella Youssef
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
| | - Jason Breuler
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
| | - Andrew L. Kleinhenz
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
| | - Andrew P. Ault
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Judy A. Westrick
- Lumigen Instrumentation Center, Department of Chemistry, Wayne State University, Detroit, MI 48202, USA;
| | - Nikolai N. Modyanov
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
| | - David J. Kennedy
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
- Correspondence: (D.J.K.); (S.T.H.); Tel.: +1-419-383-6822 (D.J.K.); +1-419-383-6859 (S.T.H.)
| | - Steven T. Haller
- College of Medicine and Life Science, University of Toledo, Toledo, OH 43614, USA; (A.L.); (J.D.B.); (R.C.S.); (J.M.); (R.K.); (A.M.); (J.N.); (S.P.); (P.H.); (M.Y.); (J.B.); (A.L.K.); (N.N.M.)
- Correspondence: (D.J.K.); (S.T.H.); Tel.: +1-419-383-6822 (D.J.K.); +1-419-383-6859 (S.T.H.)
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Hernandez BY, Zhu X, Risch HA, Lu L, Ma X, Irwin ML, Lim JK, Taddei TH, Pawlish KS, Stroup AM, Brown R, Wang Z, Wong LL, Yu H. Oral Cyanobacteria and Hepatocellular Carcinoma. Cancer Epidemiol Biomarkers Prev 2022; 31:221-229. [PMID: 34697061 PMCID: PMC8755591 DOI: 10.1158/1055-9965.epi-21-0804] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/22/2021] [Accepted: 10/14/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Gut microbial alterations have been linked to chronic liver disease and hepatocellular carcinoma (HCC). The role of the oral microbiome in liver cancer development has not been widely investigated. METHODS Bacterial 16S rRNA sequences were evaluated in oral samples from 90 HCC cases and 90 controls who were a part of a larger U.S. case-control study of HCC among patients diagnosed from 2011 to 2016. RESULTS The oral microbiome of HCC cases showed significantly reduced alpha diversity compared with controls (Shannon P = 0.002; Simpson P = 0.049), and beta diversity significantly differed (weighted Unifrac P = 0.004). The relative abundance of 30 taxa significantly varied including Cyanobacteria, which was enriched in cases compared with controls (P = 0.018). Cyanobacteria was positively associated with HCC [OR, 8.71; 95% confidence interval (CI), 1.22-62.00; P = 0.031] after adjustment for age, race, birthplace, education, smoking, alcohol, obesity, type 2 diabetes, Hepatitis C virus (HCV), Hepatitis B virus (HBV), fatty liver disease, aspirin use, other NSAID use, laboratory batch, and other significant taxa. When stratified by HCC risk factors, significant associations of Cyanobacteria with HCC were exclusively observed among individuals with negative histories of established risk factors as well as females and college graduates. Cyanobacterial genes positively associated with HCC were specific to taxa producing microcystin, the hepatotoxic tumor promotor, and other genes known to be upregulated with microcystin exposure. CONCLUSIONS Our study provides novel evidence that oral Cyanobacteria may be an independent risk factor for HCC. IMPACT These findings support future studies to further examine the causal relationship between oral Cyanobacteria and HCC risk.
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Affiliation(s)
- Brenda Y Hernandez
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, Hawaii.
| | - Xuemei Zhu
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, Hawaii
| | - Harvey A Risch
- Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale School of Medicine, New Haven, Connecticut
| | - Lingeng Lu
- Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale School of Medicine, New Haven, Connecticut
| | - Xiaomei Ma
- Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale School of Medicine, New Haven, Connecticut
| | - Melinda L Irwin
- Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale School of Medicine, New Haven, Connecticut
| | - Joseph K Lim
- Yale Liver Center and Section of Digestive Diseases, Department if Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Tamar H Taddei
- Yale Liver Center and Section of Digestive Diseases, Department if Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Karen S Pawlish
- New Jersey State Cancer Registry, New Jersey Department of Health, Trenton, New Jersey
| | - Antoinette M Stroup
- New Jersey State Cancer Registry, New Jersey Department of Health, Trenton, New Jersey
- Department of Biostatistics and Epidemiology, Rutgers School of Public Health, The State University of New Jersey, Piscataway, New Jersey
- Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey
| | - Robert Brown
- Department of Medicine, Joan & Sanford I. Weill Medical College of Cornell University, New York, New York
- Vagelos College of Physicians & Surgeons, Columbia University Irving Medical Center, New York, New York
| | - Zhanwei Wang
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, Hawaii
| | - Linda L Wong
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, Hawaii
- Department of Surgery, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii
| | - Herbert Yu
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, Hawaii
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9
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Arman T, Baron JA, Lynch KD, White LA, Aldan J, Clarke JD. MCLR-elicited hepatic fibrosis and carcinogenic gene expression changes persist in rats with diet-induced nonalcoholic steatohepatitis through a 4-week recovery period. Toxicology 2021; 464:153021. [PMID: 34740672 PMCID: PMC8629135 DOI: 10.1016/j.tox.2021.153021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/08/2021] [Accepted: 10/29/2021] [Indexed: 12/30/2022]
Abstract
Nonalcoholic steatohepatitis (NASH) causes liver extracellular matrix (ECM) remodeling and is a risk factor for fibrosis and hepatocellular carcinoma (HCC). Microcystin-LR (MCLR) is a hepatotoxin produced by fresh-water cyanobacteria that causes a NASH-like phenotype, liver fibrosis, and is also a risk factor for HCC. The focus of the current study was to investigate and compare hepatic recovery after cessation of MCLR exposure in healthy versus NASH animals. Male Sprague-Dawley rats were fed either a control or a high fat/high cholesterol (HFHC) diet for eight weeks. Animals received either vehicle or 30 μg/kg MCLR (i.p: 2 weeks, alternate days). Animals were euthanized at one of three time points: at the completion of the MCLR exposure period and after 2 and 4 weeks of recovery. Histological staining suggested that after four weeks of recovery the MCLR-exposed HFHC group had less steatosis and more fibrosis compared to the vehicle-exposed HFHC group and MCLR-exposed control group. RNA-Seq analysis revealed dysregulation of ECM genes after MCLR exposure in both control and HFHC groups that persisted only in the HFHC groups during recovery. After 4 weeks of recovery, MCLR hepatotoxicity in pre-existing NASH persistently dysregulated genes related to cellular differentiation and HCC. These data demonstrate impaired hepatic recovery and persistent carcinogenic changes after MCLR toxicity in pre-existing NASH.
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Affiliation(s)
- Tarana Arman
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA, 99202, United States
| | - J Allen Baron
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA, 99202, United States
| | - Katherine D Lynch
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA, 99202, United States
| | - Laura A White
- Washington Animal Disease Diagnostic Laboratory, Washington State University, Pullman, WA, 99164, United States
| | - Johnny Aldan
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA, 99202, United States
| | - John D Clarke
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA, 99202, United States.
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10
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Palikova M, Kopp R, Kohoutek J, Blaha L, Mares J, Ondrackova P, Papezikova I, Minarova H, Pojezdal L, Adamovsky O. Cyanobacteria Microcystis aeruginosa Contributes to the Severity of Fish Diseases: A Study on Spring Viraemia of Carp. Toxins (Basel) 2021; 13:601. [PMID: 34564605 PMCID: PMC8473110 DOI: 10.3390/toxins13090601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 08/25/2021] [Accepted: 08/25/2021] [Indexed: 11/28/2022] Open
Abstract
Fish are exposed to numerous stressors in the environment including pollution, bacterial and viral agents, and toxic substances. Our study with common carps leveraged an integrated approach (i.e., histology, biochemical and hematological measurements, and analytical chemistry) to understand how cyanobacteria interfere with the impact of a model viral agent, Carp sprivivirus (SVCV), on fish. In addition to the specific effects of a single stressor (SVCV or cyanobacteria), the combination of both stressors worsens markers related to the immune system and liver health. Solely combined exposure resulted in the rise in the production of immunoglobulins, changes in glucose and cholesterol levels, and an elevated marker of impaired liver, alanine aminotransferase (ALT). Analytical determination of the cyanobacterial toxin microcystin-LR (MC-LR) and its structurally similar congener MC-RR and their conjugates showed that SVCV affects neither the levels of MC in the liver nor the detoxification capacity of the liver. MC-LR and MC-RR were depurated from liver mostly in the form of cysteine conjugates (MC-LR-Cys, MC-RR-Cys) in comparison to glutathione conjugates (LR-GSH, RR-GSH). Our study brought new evidence that cyanobacteria worsen the effect of viral agents. Such inclusion of multiple stressor concept helps us to understand how and to what extent the relevant environmental stressors co-influence the health of the fish population.
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Affiliation(s)
- Miroslava Palikova
- Department of Ecology and Diseases of Zoo Animals, Game, Fish and Bees, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences Brno, 61242 Brno, Czech Republic; (M.P.); (I.P.); (H.M.)
- Department of Zoology, Fisheries, Hydrobiology and Apiculture, Faculty of Agronomy, Mendel University in Brno, 61300 Brno, Czech Republic; (R.K.); (J.M.)
| | - Radovan Kopp
- Department of Zoology, Fisheries, Hydrobiology and Apiculture, Faculty of Agronomy, Mendel University in Brno, 61300 Brno, Czech Republic; (R.K.); (J.M.)
| | - Jiri Kohoutek
- RECETOX (Research Centre for Toxic Compounds in the Environment), Faculty of Science, Masaryk University, 62500 Brno, Czech Republic; (J.K.); (L.B.)
| | - Ludek Blaha
- RECETOX (Research Centre for Toxic Compounds in the Environment), Faculty of Science, Masaryk University, 62500 Brno, Czech Republic; (J.K.); (L.B.)
| | - Jan Mares
- Department of Zoology, Fisheries, Hydrobiology and Apiculture, Faculty of Agronomy, Mendel University in Brno, 61300 Brno, Czech Republic; (R.K.); (J.M.)
| | - Petra Ondrackova
- Department of Infectious Diseases and Preventive Medicine, Veterinary Research Institute, 62100 Brno, Czech Republic; (P.O.); (L.P.)
| | - Ivana Papezikova
- Department of Ecology and Diseases of Zoo Animals, Game, Fish and Bees, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences Brno, 61242 Brno, Czech Republic; (M.P.); (I.P.); (H.M.)
- Department of Zoology, Fisheries, Hydrobiology and Apiculture, Faculty of Agronomy, Mendel University in Brno, 61300 Brno, Czech Republic; (R.K.); (J.M.)
| | - Hana Minarova
- Department of Ecology and Diseases of Zoo Animals, Game, Fish and Bees, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences Brno, 61242 Brno, Czech Republic; (M.P.); (I.P.); (H.M.)
- Department of Infectious Diseases and Preventive Medicine, Veterinary Research Institute, 62100 Brno, Czech Republic; (P.O.); (L.P.)
| | - Lubomir Pojezdal
- Department of Infectious Diseases and Preventive Medicine, Veterinary Research Institute, 62100 Brno, Czech Republic; (P.O.); (L.P.)
| | - Ondrej Adamovsky
- RECETOX (Research Centre for Toxic Compounds in the Environment), Faculty of Science, Masaryk University, 62500 Brno, Czech Republic; (J.K.); (L.B.)
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11
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Arman T, Clarke JD. Microcystin Toxicokinetics, Molecular Toxicology, and Pathophysiology in Preclinical Rodent Models and Humans. Toxins (Basel) 2021; 13:toxins13080537. [PMID: 34437407 PMCID: PMC8402503 DOI: 10.3390/toxins13080537] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 07/23/2021] [Accepted: 07/27/2021] [Indexed: 02/06/2023] Open
Abstract
Microcystins are ubiquitous toxins produced by photoautotrophic cyanobacteria. Human exposures to microcystins occur through the consumption of contaminated drinking water, fish and shellfish, vegetables, and algal dietary supplements and through recreational activities. Microcystin-leucine-arginine (MCLR) is the prototypical microcystin because it is reported to be the most common and toxic variant and is the only microcystin with an established tolerable daily intake of 0.04 µg/kg. Microcystin toxicokinetics is characterized by low intestinal absorption, rapid and specific distribution to the liver, moderate metabolism to glutathione and cysteinyl conjugates, and low urinary and fecal excretion. Molecular toxicology involves covalent binding to and inhibition of protein phosphatases, oxidative stress, cell death (autophagy, apoptosis, necrosis), and cytoskeleton disruption. These molecular and cellular effects are interconnected and are commonly observed together. The main target organs for microcystin toxicity are the intestine, liver, and kidney. Preclinical data indicate microcystins may also have nervous, pulmonary, cardiac, and reproductive system toxicities. Recent evidence suggests that exposure to other hepatotoxic insults could potentiate microcystin toxicity and increase the risk for chronic diseases. This review summarizes the current knowledge for microcystin toxicokinetics, molecular toxicology, and pathophysiology in preclinical rodent models and humans. More research is needed to better understand human toxicokinetics and how multifactorial exposures contribute to disease pathogenesis and progression.
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12
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Arman T, Lynch KD, Goedken M, Clarke JD. Sub-chronic microcystin-LR renal toxicity in rats fed a high fat/high cholesterol diet. CHEMOSPHERE 2021; 269:128773. [PMID: 33143886 PMCID: PMC8276626 DOI: 10.1016/j.chemosphere.2020.128773] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/24/2020] [Accepted: 10/25/2020] [Indexed: 05/16/2023]
Abstract
Microcystin-LR (MCLR) is a liver and kidney toxin produced by cyanobacteria. Recently, it was demonstrated that MCLR exposure drives the progression of high fat/high cholesterol (HFHC) induced nonalcoholic fatty liver disease (NAFLD) to a more severe state. NAFLD is also a risk factor for chronic kidney disease (CKD), and the current study investigated MCLR renal toxicity in the context of an HFHC diet. Sprague Dawley rats were fed either a control diet or an HFHC diet for 10 weeks. After 6 weeks of diet, animals were administered either vehicle, 10 μg/kg, or 30 μg/kg MCLR via intraperitoneal injection every other day for 4 weeks. HFHC diet alone increased the renal glomerular change histopathology score, and 30 μg/kg MCLR exposure increased this score in both the control group and the HFHC group. In contrast, 30 μg/kg MCLR caused greater proteinuria and cast formation and decreased protein phosphatase 1 and 2A protein expression in the HFHC group. Urinary excretion of KIM-1 increased, but albumin and tamm-horsfall protein did not change after MCLR exposure. The general concordance between KIM-1, polyuria, proteinuria, and renal casts after MCLR exposure suggests that proximal tubule cell damage contributed to these connected pathologies. The control group adapted to repeated MCLR exposure by increasing the urinary elimination of MCLR and its metabolites, whereas this adaptation was blunted in the HFHC group. These data suggest an HFHC diet may increase the severity of certain MCLR-elicited renal toxicities.
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Affiliation(s)
- Tarana Arman
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA, 99202, USA
| | - Katherine D Lynch
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA, 99202, USA
| | - Michael Goedken
- Department of Pharmacology and Toxicology, Rutgers University, Piscataway, NJ, 08901, USA
| | - John D Clarke
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA, 99202, USA.
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13
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Li Z, Zhang J, Zhang Y, Zhou L, Zhao J, Lyu Y, Poon LH, Lin Z, To KKW, Yan X, Zuo Z. Intestinal absorption and hepatic elimination of drugs in high-fat high-cholesterol diet-induced non-alcoholic steatohepatitis rats: exemplified by simvastatin. Br J Pharmacol 2020; 178:582-599. [PMID: 33119943 DOI: 10.1111/bph.15298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 10/12/2020] [Accepted: 10/20/2020] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND AND PURPOSE Altered drug pharmacokinetics is a significant concern in non-alcoholic steatohepatitis (NASH) patients. Although high-fat high-cholesterol (HFHC) diet-induced NASH (HFHC-NASH) rats could simulate the typical dysregulation of cholesterol in NASH patients, experimental investigation on the altered drug pharmacokinetics in this model are limited. Thus, the present study comprehensive investigates the nature of such altered pharmacokinetics using simvastatin as the model drug. EXPERIMENTAL APPROACH Pharmacokinetic profiles of simvastatin and its active metabolite simvastatin acid together with compartmental pharmacokinetic modelling were used to identify the key factors involved in the altered pharmacokinetics of simvastatin in HFHC-NASH rats. Experimental investigations via in situ single-pass intestinal perfusion and intrahepatic injection of simvastatin were carried out. Histology, Ces1 activities and mRNA/protein levels of Oatp1b2/CYP2c11/P-gp in the small intestine/liver of healthy and HFHC-NASH rats were compared. KEY RESULTS Reduced intestinal absorption and more extensive hepatic elimination in HFHC-NASH rats resulted in less systemic exposures of simvastatin/simvastatin acid. In the small intestine of HFHC-NASH rats, thicker intestinal wall with more collagen fibres, increased Ces1 activity and up-regulated P-gp protein decreased the permeability of simvastatin, accelerated the hydrolysis of simvastatin and promoted the efflux of simvastatin acid respectively. In the liver of HFHC-NASH rats, higher hepatic P-gp expression accelerated the hepatic elimination of simvastatin. CONCLUSION AND IMPLICATIONS Altered histology, Ces1 activity and P-gp expression in the small intestine/liver were identified to be the major contributing factors leading to less systemic exposure of drugs in HFHC-NASH rats, which may be applicable to NASH patients.
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Affiliation(s)
- Ziwei Li
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Jun Zhang
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Yufeng Zhang
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Limin Zhou
- School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong
| | - Jiajia Zhao
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Yuanfeng Lyu
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Long Hin Poon
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Zhixiu Lin
- School of Chinese Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Kenneth Kin Wah To
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Xiaoyu Yan
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Zhong Zuo
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
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14
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Chronic Low Dose Oral Exposure to Microcystin-LR Exacerbates Hepatic Injury in a Murine Model of Non-Alcoholic Fatty Liver Disease. Toxins (Basel) 2019; 11:toxins11090486. [PMID: 31450746 PMCID: PMC6783870 DOI: 10.3390/toxins11090486] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/15/2019] [Accepted: 08/19/2019] [Indexed: 12/17/2022] Open
Abstract
Microcystins are potent hepatotoxins that have become a global health concern in recent years. Their actions in at-risk populations with pre-existing liver disease is unknown. We tested the hypothesis that the No Observed Adverse Effect Level (NOAEL) of Microcystin-LR (MC-LR) established in healthy mice would cause exacerbation of hepatic injury in a murine model (Leprdb/J) of Non-alcoholic Fatty Liver Disease (NAFLD). Ten-week-old male Leprdb/J mice were gavaged with 50 μg/kg, 100 μg/kg MC-LR or vehicle every 48 h for 4 weeks (n = 15–17 mice/group). Early mortality was observed in both the 50 μg/kg (1/17, 6%), and 100 μg/kg (3/17, 18%) MC-LR exposed mice. MC-LR exposure resulted in significant increases in circulating alkaline phosphatase levels, and histopathological markers of hepatic injury as well as significant upregulation of genes associated with hepatotoxicity, necrosis, nongenotoxic hepatocarcinogenicity and oxidative stress response. In addition, we observed exposure dependent changes in protein phosphorylation sites in pathways involved in inflammation, immune function, and response to oxidative stress. These results demonstrate that exposure to MC-LR at levels that are below the NOAEL established in healthy animals results in significant exacerbation of hepatic injury that is accompanied by genetic and phosphoproteomic dysregulation in key signaling pathways in the livers of NAFLD mice.
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15
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Arman T, Lynch KD, Montonye ML, Goedken M, Clarke JD. Sub-Chronic Microcystin-LR Liver Toxicity in Preexisting Diet-Induced Nonalcoholic Steatohepatitis in Rats. Toxins (Basel) 2019; 11:E398. [PMID: 31323923 PMCID: PMC6669744 DOI: 10.3390/toxins11070398] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/02/2019] [Accepted: 07/04/2019] [Indexed: 02/07/2023] Open
Abstract
Microcystin-LR (MCLR) is a hepatotoxic cyanotoxin reported to cause a phenotype similar to nonalcoholic steatohepatitis (NASH). NASH is a common progressive liver disease that advances in severity due to exogenous stressors such as poor diet and toxicant exposure. Our objective was to determine how sub-chronic MCLR toxicity affects preexisting diet-induced NASH. Sprague-Dawley rats were fed one of three diets for 10 weeks: control, methionine and choline deficient (MCD), or high fat/high cholesterol (HFHC). After six weeks of diet, animals received vehicle, 10 µg/kg, or 30 µg/kg MCLR via intraperitoneal injection every other day for the final 4 weeks. Incidence and severity scoring of histopathology endpoints suggested that MCLR toxicity drove NASH to a less fatty and more fibrotic state. In general, expression of genes involved in de novo lipogenesis and fatty acid esterification were altered in favor of decreased steatosis. The higher MCLR dose increased expression of genes involved in fibrosis and inflammation in the control and HFHC groups. These data suggest MCLR toxicity in the context of preexisting NASH may drive the liver to a more severe phenotype that resembles burnt-out NASH.
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Affiliation(s)
- Tarana Arman
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA 99202, USA
| | - Katherine D Lynch
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA 99202, USA
| | - Michelle L Montonye
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA 99202, USA
| | - Michael Goedken
- Department of Pharmacology and Toxicology, Rutgers University, Piscataway, NJ 08901, USA
| | - John D Clarke
- Department of Pharmaceutical Sciences, Washington State University, Spokane, WA 99202, USA.
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