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Padmaja D, Rajegowda H, Chethan B, Krishnamurthy P, Khan RUR, Suchetan P, Lokanath N, Somashekar M, Jayashankar B. New thioether-hydrazide based ONS donor Schiff base and its Pd(II) complex: Synthesis, crystal structure, thermal analysis, hirshfeld surface analysis, quantum chemical studies and molecular docking. J Mol Struct 2023. [DOI: 10.1016/j.molstruc.2023.135041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Qin X, Hakenjos JM, MacKenzie KR, Barzi M, Chavan H, Nyshadham P, Wang J, Jung SY, Guner JZ, Chen S, Guo L, Krishnamurthy P, Bissig KD, Palmer S, Matzuk MM, Li F. Metabolism of a Selective Serotonin and Norepinephrine Reuptake Inhibitor Duloxetine in Liver Microsomes and Mice. Drug Metab Dispos 2022; 50:128-139. [PMID: 34785568 PMCID: PMC8969139 DOI: 10.1124/dmd.121.000633] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 10/12/2021] [Indexed: 11/25/2022] Open
Abstract
Duloxetine (DLX) is a dual serotonin and norepinephrine reuptake inhibitor, widely used for the treatment of major depressive disorder. Although DLX has shown good efficacy and safety, serious adverse effects (e.g., liver injury) have been reported. The mechanisms associated with DLX-induced toxicity remain elusive. Drug metabolism plays critical roles in drug safety and efficacy. However, the metabolic profile of DLX in mice is not available, although mice serve as commonly used animal models for mechanistic studies of drug-induced adverse effects. Our study revealed 39 DLX metabolites in human/mouse liver microsomes and mice. Of note, 13 metabolites are novel, including five N-acetyl cysteine adducts and one reduced glutathione (GSH) adduct associated with DLX. Additionally, the species differences of certain metabolites were observed between human and mouse liver microsomes. CYP1A2 and CYP2D6 are primary enzymes responsible for the formation of DLX metabolites in liver microsomes, including DLX-GSH adducts. In summary, a total of 39 DLX metabolites were identified, and species differences were noticed in vitro. The roles of CYP450s in DLX metabolite formation were also verified using human recombinant cytochrome P450 (P450) enzymes and corresponding chemical inhibitors. Further studies are warranted to address the exact role of DLX metabolism in its adverse effects in vitro (e.g., human primary hepatocytes) and in vivo (e.g., Cyp1a2-null mice). SIGNIFICANCE STATEMENT: This current study systematically investigated Duloxetine (DLX) metabolism and bioactivation in liver microsomes and mice. This study provided a global view of DLX metabolism and bioactivation in liver microsomes and mice, which are very valuable to further elucidate the mechanistic study of DLX-related adverse effects and drug-drug interaction from metabolic aspects.
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Affiliation(s)
- Xuan Qin
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - John M Hakenjos
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - Kevin R MacKenzie
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - Mercedes Barzi
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - Hemantkumar Chavan
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - Pranavanand Nyshadham
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - Jin Wang
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - Sung Yun Jung
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - Joie Z Guner
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - Si Chen
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - Lei Guo
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - Partha Krishnamurthy
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - Karl-Dimiter Bissig
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - Stephen Palmer
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - Martin M Matzuk
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
| | - Feng Li
- Center for Drug Discovery, Department of Pathology & Immunology (X.Q., J.M.H., K.R.M., P.N., J.Z.G., S.P., M.M.M., F.L.), NMR and Drug Metabolism Core, Advanced Technology Cores (K.R.M., F.L.), Department of Pharmacology & Chemical Biology (K.R.M., J.W., M.M.M., F.L.), and Department of Molecular & Cellular Biology (S.Y.J., K.-D.B., F.L.), Baylor College of Medicine, Houston, Texas; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (M.B., K.-D.B.); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas (H.C., P.K.); and Division of Biochemical Toxicology, National Center for Toxicological Research/US Food and Drug Administration (FDA), Jefferson, Arkansas (S.C., L.G.)
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Anton-Vazquez V, Smith M, Mehra V, Avenoso D, Krishnamurthy P, Kulasekararaj A, Potter V, Pagliuca A, Zuckerman M. Human parainfluenza virus type 3 infections in a haemato-oncology unit: social distancing measures needed in outpatient clinics. J Hosp Infect 2021; 116:60-68. [PMID: 34400235 DOI: 10.1016/j.jhin.2021.07.011] [Citation(s) in RCA: 3] [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: 05/11/2021] [Revised: 06/30/2021] [Accepted: 07/27/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Human parainfluenza virus type 3 (HPIV3) infections are associated with high mortality in immunocompromised settings, especially in bone marrow transplant recipients. Asymptomatic infection and lack of effective antiviral treatment makes HPIV3 prevention and treatment a real challenge. AIM To retrospectively investigate the epidemiological characteristics, clinical characteristics and outcomes of 51 haematology patients with confirmed HPIV3 infections, detected between February and May 2019 in the haematology unit at King's College Hospital, London. METHODS Between February and May 2019, HPIV3 RNA was detected in combined nose and throat swab samples collected from 51 symptomatic haematology patients, 41 of whom attended the haematology outpatient unit. Clinical data were reviewed retrospectively and a timeline of patients' appointments drawn up to investigate transmission. Sequencing analysis was performed on 14 stored samples. FINDINGS Fifty-one patients were identified with HPIV3 infection. Mean age was 54 years (SD: 12; range: 19-72) and 60% (31/51) were male. There were 41 (80%) bone marrow transplant recipients, 24 had an allograft, and 17 an autograft. Thirty-day and 3-month mortality post HPIV3 was 6% and 14%, respectively. Lower respiratory tract infection and inpatient acquisition were associated with higher mortality (6/7 vs 1/7, P = 0.010; and 5/7 vs 2/7, P = 0.031). Onset of HPIV3 infection in patients within 6 days of attending the clinic was associated with the clusters identified in phylogenetic analysis (64% (9/14) vs 21% (8/37); odds ratio: 6.5 (confidence interval: 95% 1.7-25); P = 0.006). CONCLUSION Timelines suggested community transmission, but also possible transmission patterns within the outpatients and subsequent nosocomial transmission within the same ward. Early recognition of HPIV3 infection and the use of polymerase chain reaction and sequence analysis is fundamental in identifying respiratory virus outbreaks and person-to-person transmission. Careful planning of outpatient clinic attendance is required to minimize contact and prevent respiratory virus transmission in immunosuppressed patients.
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Affiliation(s)
- V Anton-Vazquez
- South London Specialist Virology Centre, King's College Hospital, London, UK.
| | - M Smith
- South London Specialist Virology Centre, King's College Hospital, London, UK
| | - V Mehra
- Department of Haematology, King's College Hospital NHS Foundation Trust, London, UK
| | - D Avenoso
- Department of Haematology, King's College Hospital NHS Foundation Trust, London, UK
| | - P Krishnamurthy
- Department of Haematology, King's College Hospital NHS Foundation Trust, London, UK
| | - A Kulasekararaj
- Department of Haematology, King's College Hospital NHS Foundation Trust, London, UK
| | - V Potter
- Department of Haematology, King's College Hospital NHS Foundation Trust, London, UK
| | - A Pagliuca
- Department of Haematology, King's College Hospital NHS Foundation Trust, London, UK
| | - M Zuckerman
- South London Specialist Virology Centre, King's College Hospital, London, UK
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Abouleish AE, Vinta SR, Shabot SM, Patel NV, Hurwitz EE, Krishnamurthy P, Simon M. Improving agreement of ASA physical status class between pre-anesthesia screening and day of surgery by adding institutional-specific and ASA-approved examples: a quality improvement project. Perioper Med (Lond) 2020; 9:34. [PMID: 33292640 PMCID: PMC7677831 DOI: 10.1186/s13741-020-00162-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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: 05/01/2020] [Accepted: 10/29/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND A successful anesthesia pre-assessment clinic needs to identify patients who need further testing, evaluation, and optimization prior to the day of surgery to avoid delays and cancelations. Although the ASA Physical Status Classification system (ASA PS) has been used widely for over 50 years, it has poor interrater agreement when only using the definitions. In 2014, ASA-approved examples for each ASA physical status class (ASA PS). In this quality improvement study, we developed and evaluated the effectiveness of institutional-specific examples on interrater reliability between anesthesia pre-anesthesia clinic (APAC) and the day of surgery evaluation (DOS). METHODS A multi-step, multi-year quality improvement project was performed. Step 1, pre-intervention, was a retrospective review to determine the percentage agreement of ASA PS assignment between APAC and DOS for adult and pediatric patients. Step 2 was a retrospective review of the step 1 cases where the ASA PS assignment differed to determine which medical conditions were valued differently and then develop institutional-specific examples for medical conditions not addressed by ASA-approved examples. Step 3 was to educate clinicians about the newly implemented examples and how they should be used as a guide. Step 4, post-intervention, was a retrospective review to determine if the examples improved agreement between APAC and DOS ASA PS assignments. Weighted Kappa coefficient was used to measure of interrater agreement excluding chance agreement. RESULTS Having only ASA PS definitions available, APAC and DOS agreement was only 74% for adults (n = 737) and 63% for pediatric patients (n = 216). For adults, 20 medical co-morbidity categories and, for pediatric patients, 9 medical co-morbidity categories accounted for > 90% the differences in ASA PS. After development and implementation of institutional-specific examples with ASA-approved examples, the percentage agreement increased for adult patients (n = 795) to 91% and for pediatric patients (n = 239) to 84%. Weighted Kappa coefficients increased significantly for all patients (from 0.62 to 0.85, p < .0001), adult patients (from 0.62 to 0.86, p < .0001), and pediatric patients (from 0.48 to 0.78, p < .0001). CONCLUSIONS ASA-approved examples do not address all medical conditions that account for differences in the assignment of ASA PS between pre-anesthesia screening and day of anesthesia evaluation at our institution. The process of developing institutional-specific examples addressed the medical conditions that caused differences in assignment at one institution. The implementation of ASA PS examples improved consistency of assignment, and therefore communication of medical conditions of patients presenting for anesthesia care.
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Affiliation(s)
- Amr E. Abouleish
- Department of Anesthesiology, University of Texas Medical Branch, Medical Branch, 301 University Blvd. Rt 0877, Galveston, TX 77555 USA
| | - Sandhya R. Vinta
- Department of Anesthesiology, University of Texas Medical Branch, Medical Branch, 301 University Blvd. Rt 0877, Galveston, TX 77555 USA
| | - Sarah M. Shabot
- Department of Anesthesiology, University of Texas Medical Branch, Medical Branch, 301 University Blvd. Rt 0877, Galveston, TX 77555 USA
| | - Nikul V. Patel
- Department of Anesthesiology, University of Texas Medical Branch, Medical Branch, 301 University Blvd. Rt 0877, Galveston, TX 77555 USA
| | - Erin E. Hurwitz
- Affiliated Anesthesiologists, LLC, Oklahoma City, OK 73120 USA
| | | | - Michelle Simon
- Department of Anesthesiology, University of Texas Medical Branch, Medical Branch, 301 University Blvd. Rt 0877, Galveston, TX 77555 USA
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Hah JM, Trafton JA, Narasimhan B, Krishnamurthy P, Hilmoe H, Sharifzadeh Y, Huddleston JI, Amanatullah D, Maloney WJ, Goodman S, Carroll I, Mackey SC. Efficacy of motivational-interviewing and guided opioid tapering support for patients undergoing orthopedic surgery (MI-Opioid Taper): A prospective, assessor-blind, randomized controlled pilot trial. EClinicalMedicine 2020; 28:100596. [PMID: 33294812 PMCID: PMC7700897 DOI: 10.1016/j.eclinm.2020.100596] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
BACKGROUND Postoperative opioid use can lead to chronic use and misuse. Few studies have examined effective approaches to taper postoperative opioid use while maintaining adequate analgesia. METHODS This randomized, assessor-blinded, pilot trial of postoperative motivational interviewing and guided opioid tapering support (MI-Opioid Taper) added to usual care (UC) enrolled patients undergoing total hip or knee arthroplasty at a single U.S. academic medical center. MI-Opioid Taper involved weekly (to seven weeks) and monthly (to one year) phone calls until patient-reported opioid cessation. Opioid tapering involved 25% weekly dose reductions. The primary feasibility outcome was study completion in the group to which participants were randomized. The primary efficacy outcome, time to baseline opioid use, was the first of five consecutive days of return to baseline preoperative dose. Intention-to-treat analysis with Cox proportional hazards regression was adjusted for operation. ClinicalTrials.gov registration: NCT02070003. FINDINGS From November 26, 2014, to April 27, 2018, 209 patients were screened, and 104 patients were assigned to receive MI-Opioid Taper (49 patients) or UC only (55 patients). Study completion after randomization was similar between groups (96.4%, 53 patients receiving UC, 91.8%, 45 patients receiving MI-Opioid Taper). Patients receiving MI-Opioid Taper had a 62% increase in the rate of return to baseline opioid use after surgery (HR 1.62; 95%CI 1.06-2.46; p = 0•03). No trial-related adverse events occurred. INTERPRETATION In patients undergoing total joint arthroplasty, MI-Opioid Taper is feasible and future research is needed to establish the efficacy of MI-Opioid Taper to promote postoperative opioid cessation. FUNDING National Institute on Drug Abuse.
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Affiliation(s)
- Jennifer M. Hah
- Division of Pain Medicine, Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University, 1070 Arastradero Rd., Suite 200, Stanford, CA 94304, United States
- Corresponding author.
| | - Jodie A. Trafton
- Psychiatry and Behavioral Sciences, Stanford University, Director, VA Program Evaluation and Resource Center, VHA Office of Mental Health and Suicide Prevention, Menlo Park, CA, United States
| | - Balasubramanian Narasimhan
- Department of Statistics, Department of Biomedical Data Sciences, Stanford University, Stanford CA, United States
| | - Partha Krishnamurthy
- Department of Marketing and Entrepreneurship, C. T. Bauer College of Business, University of Houston, Houston, Texas, United States
| | - Heather Hilmoe
- Stanford Systems Neuroscience and Pain Lab, Stanford University, Stanford, California, United States
| | - Yasamin Sharifzadeh
- Stanford Systems Neuroscience and Pain Lab, Stanford University, Stanford, California, United States
| | - James I. Huddleston
- Department of Orthopaedic Surgery, Stanford University, Stanford, California, United States
| | - Derek Amanatullah
- Department of Orthopaedic Surgery, Stanford University, Stanford, California, United States
| | | | - Stuart Goodman
- Department of Orthopaedic Surgery and (by courtesy) Bioengineering, Department of Orthopaedic Surgery, Stanford University, United States
| | - Ian Carroll
- Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University, Stanford, California, United States
| | - Sean C. Mackey
- Division of Pain Medicine, Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University, United States
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Romman A, Doulatram G, Doctor N, Krishnamurthy P. Sensitivity and specificity of SOAPP-SF questionnaire for predicting aberrant urine drug screen. Reg Anesth Pain Med 2020; 45:763-764. [DOI: 10.1136/rapm-2019-101179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/30/2020] [Accepted: 02/04/2020] [Indexed: 11/04/2022]
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7
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Li C, He C, Xu Y, Xu H, Tang Y, Chavan H, Duan S, Artigues A, Laird Forrest M, Krishnamurthy P, Han S, Holzbeierlein JM, Li B. Alternol eliminates excessive ATP production by disturbing Krebs cycle in prostate cancer. Prostate 2019; 79:628-639. [PMID: 30663084 PMCID: PMC6644699 DOI: 10.1002/pros.23767] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 12/28/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Alternol is a natural compound isolated from fermentation products of a mutant fungus. Our previous studies demonstrated that Alternol specifically kills cancer cells but spares benign cells. METHODS To investigate the mechanism underlying alternol-induced cancer cell-specific killing effect, we took a comprehensive strategy to identify Alternol's protein targets in prostate cancer cells, including PC-3, C4-2, and 22RV1, plus benign BPH1 cell lines. Major experimental techniques included biotin-streptavidin pulldown assay coupled with mass-spectrometry, in vitro enzyme activity assay for Krebs cycle enzymes and gas chromatography-mass spectrometry (GC-MS) for metabolomic analysis. RESULTS Among 14 verified protein targets, four were Krebs cycle enzymes, fumarate hydratase (FH), malate dehydrogenase-2 (MDH2), dihydrolipoamide acetyltransferase (DLAT) in pyruvate dehydrogenase complex (PDHC) and dihydrolipoamide S-succinyltransferase (DLST) in a-ketoglutarate dehydrogenase complex (KGDHC). Functional assays revealed that PDHC and KGDHC activities at the basal level were significantly higher in prostate cancer cells compared to benign prostate BPH1 cells, while alternol treatment reduced their activities in cancer cells close to the levels in BPH1 cells. Although FH and MDH2 activities were comparable among prostate cancer and benign cell lines at the basal level, Alternol treatment largely increased their activities in cancer cells. Metabolomic analysis revealed that Alternol treatment remarkably reduced the levels of malic acid, fumaric acid, and isocitric acid and mitochondrial respiration in prostate cancer cells. Alternol also drastically reduced mitochondrial respiration and ATP production in PC-3 cells in vitro or in xenograft tissues but not in BPH1 cells or host liver tissues. CONCLUSIONS Alternol interacts with multiple Krebs cycle enzymes, resulting in reduced mitochondrial respiration and ATP production in prostate cancer cells and xenograft tissues, providing a novel therapeutic strategy for prostate cancer treatment.
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Affiliation(s)
- Changlin Li
- Institute of Precision Medicine, Jining Medical University, Jining, China
- Department of Urology, The University of Kansas Medical Center, Kansas City, Kansas
| | - Chenchen He
- Department of Urology, The University of Kansas Medical Center, Kansas City, Kansas
- Department of Radiation Oncology, The First Affiliated Hospital, Xi’An Jiaotong University School of Medicine, Xi’An, China
| | - Ying Xu
- Department of Urology, The University of Kansas Medical Center, Kansas City, Kansas
| | - Haixia Xu
- Department of Urology, The University of Kansas Medical Center, Kansas City, Kansas
| | - Yuzhe Tang
- Department of Urology, The University of Kansas Medical Center, Kansas City, Kansas
| | - Hemantkumar Chavan
- Department of Pharmacology, Toxicology & Therapeutics, The University of Kansas Medical Center, Kansas City, Kansas
| | - Shaofeng Duan
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, Kansas
| | - Antonio Artigues
- Department of Biochemistry & Molecular Biology, The University of Kansas Medical Center, Kansas City, Kansas
| | - Marcus Laird Forrest
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, Kansas
| | - Partha Krishnamurthy
- Department of Pharmacology, Toxicology & Therapeutics, The University of Kansas Medical Center, Kansas City, Kansas
| | - Suxia Han
- Department of Radiation Oncology, The First Affiliated Hospital, Xi’An Jiaotong University School of Medicine, Xi’An, China
| | | | - Benyi Li
- Department of Urology, The University of Kansas Medical Center, Kansas City, Kansas
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8
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Agbas A, Krishnamurthy P, Michaelis ML, Michaelis EK. Mitochondrial Electron Transfer Cascade Enzyme Activity Assessment in Cultured Neurons and Select Brain Regions. ACTA ACUST UNITED AC 2019; 80:e73. [PMID: 30951613 PMCID: PMC6585421 DOI: 10.1002/cptx.73] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Measurement of the electron transfer cascade (ETC) enzyme activities and their kinetic profiles is important in assessing mitochondrial function in the nervous system in health and disease or following exposure to toxic agents. The optimization of enzymatic assays for brain tissues and neurons is critical to the development of high-throughput assay formats. This article describes a step-by-step protocol for reliable and reproducible assessment of ETC enzyme kinetics (Complex I-IV) for mitochondria from small quantities of tissue from different brain regions, such as the hippocampus, cerebellum, and frontal cortex, or from neurons in culture. Methods for differential and density gradient centrifugation are detailed for isolating cell body and synaptic mitochondria from brain, as well as measurement of ETC activities in microwell plate or single-cuvette format using spectrophotometric methods. Easy-to follow assay layouts and useful tips are presented, allowing the user to perform these assays in under 3 hr. © 2019 by John Wiley & Sons, Inc.
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Affiliation(s)
- Abdulbaki Agbas
- Department of Biosciences, Kansas City University of Medicine and Biosciences, Kansas City, Missouri
| | - Partha Krishnamurthy
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Mary L Michaelis
- Higuchi Biosciences Center and University of Kansas Alzheimer's Disease Center, Lawrence, Kansas
| | - Elias K Michaelis
- Higuchi Biosciences Center and University of Kansas Alzheimer's Disease Center, Lawrence, Kansas
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9
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Lynch JA, Fukuda Y, Krishnamurthy P, Wijaya J, Wang Y, Herras A, Cheepala S, Bao J, Nourse A, Milasta S, Neale G, Zheng J, Green D, Chi H, Schuetz J. Heme Interaction with the Pyruvate Dehydrogenase Complex: A Novel Strategy to Promote Hypoxic Survival. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.652.12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Yu Fukuda
- Pharm SciSt Jude Children's Research HospitalMemphisTN
| | | | - Juwina Wijaya
- Pharm SciSt Jude Children's Research HospitalMemphisTN
| | - Yao Wang
- Pharm SciSt Jude Children's Research HospitalMemphisTN
| | - Andras Herras
- Molecular Interraction AnalysisSt Jude Children's Research HospitalMemphisTN
| | | | - Ju Bao
- Structural BiologySt Jude Children's Research HospitalMemphisTN
| | - Amanda Nourse
- Molecular Interaction AnalysisSt Jude Children's Research HospitalMemphisTN
| | | | - Geoffrey Neale
- Hartwell CenterSt Jude Children's Research HospitalMemphisTN
| | - Jie Zheng
- Hartwell CenterSt Jude Children's Research HospitalMemphisTN
| | - Douglas Green
- ImmunologySt Jude Children's Research HospitalMemphisTN
| | - Hongbo Chi
- Molecular Interraction AnalysisSt Jude Children's Research HospitalMemphisTN
| | - John Schuetz
- Pharm SciSt Jude Children's Research HospitalMemphisTN
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10
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Wang H, Ni HM, Chao X, Ma X, Rodriguez YA, Chavan H, Wang S, Krishnamurthy P, Dobrowsky R, Xu DX, Jaeschke H, Ding WX. Double deletion of PINK1 and Parkin impairs hepatic mitophagy and exacerbates acetaminophen-induced liver injury in mice. Redox Biol 2019; 22:101148. [PMID: 30818124 PMCID: PMC6395945 DOI: 10.1016/j.redox.2019.101148] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [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: 12/15/2018] [Revised: 02/16/2019] [Accepted: 02/17/2019] [Indexed: 01/05/2023] Open
Abstract
Mitochondria damage plays a critical role in acetaminophen (APAP)-induced necrosis and liver injury. Cells can adapt and protect themselves by removing damaged mitochondria via mitophagy. PINK1-Parkin pathway is one of the major pathways that regulate mitophagy but its role in APAP-induced liver injury is still elusive. We investigated the role of PINK1-Parkin pathway in hepatocyte mitophagy in APAP-induced liver injury in mice. Wild-type (WT), PINK1 knockout (KO), Parkin KO, and PINK1 and Parkin double KO (DKO) mice were treated with APAP for different time points. Liver injury was determined by measuring serum alanine aminotransferase (ALT) activity, H&E staining as well as TUNEL staining of liver tissues. Tandem fluorescent-tagged inner mitochondrial membrane protein Cox8 (Cox8-GFP-mCherry) can be used to monitor mitophagy based on different pH stability of GFP and mCherry fluorescent proteins. We overexpressed Cox8-GFP-mCherry in mouse livers via tail vein injection of an adenovirus Cox8-GFP-mCherry. Mitophagy was assessed by confocal microscopy for Cox8-GFP-mCherry puncta, electron microscopy (EM) analysis for mitophagosomes and western blot analysis for mitochondrial proteins. Parkin KO and PINK1 KO mice improved the survival after treatment with APAP although the serum levels of ALT were not significantly different among PINK1 KO, Parkin KO and WT mice. We only found mild defects of mitophagy in PINK1 KO or Parkin KO mice after APAP, and improved survival in PINK1 KO and Parkin KO mice could be due to other functions of PINK1 and Parkin independent of mitophagy. In contrast, APAP-induced mitophagy was significantly impaired in PINK1-Parkin DKO mice. PINK1-Parkin DKO mice had further elevated serum levels of ALT and increased mortality after APAP administration. In conclusion, our results demonstrated that PINK1-Parkin signaling pathway plays a critical role in APAP-induced mitophagy and liver injury. Cox8-GFP-mCherry is a novel molecular probe to monitor mitophagy in cultured hepatocytes and in mouse livers. . Double deletion of PINK1 and Parking exacerbates acetaminophen-induced liver injury and mortality in mice.
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Affiliation(s)
- Hua Wang
- Department of Toxicology, School of Public Health, Anhui Medical University, Hefei City, Anhui Province, 230032, China; Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Hong-Min Ni
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Xiaojuan Chao
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Xiaowen Ma
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Yssa Ann Rodriguez
- Department of Pharmacology and Toxicology, University of Kansas, Lawrence, KS, 66045, USA
| | - Hemantkumar Chavan
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Shaogui Wang
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Partha Krishnamurthy
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Rick Dobrowsky
- Department of Pharmacology and Toxicology, University of Kansas, Lawrence, KS, 66045, USA
| | - De-Xiang Xu
- Department of Toxicology, School of Public Health, Anhui Medical University, Hefei City, Anhui Province, 230032, China
| | - Hartmut Jaeschke
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, 66160, USA.
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11
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Kumar RP, Ray S, Home P, Saha B, Bhattacharya B, Wilkins HM, Chavan H, Ganguly A, Milano-Foster J, Paul A, Krishnamurthy P, Swerdlow RH, Paul S. Regulation of energy metabolism during early mammalian development: TEAD4 controls mitochondrial transcription. Development 2018; 145:dev.162644. [PMID: 30201685 DOI: 10.1242/dev.162644] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [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: 12/28/2017] [Accepted: 08/31/2018] [Indexed: 12/27/2022]
Abstract
Early mammalian development is crucially dependent on the establishment of oxidative energy metabolism within the trophectoderm (TE) lineage. Unlike the inner cell mass, TE cells enhance ATP production via mitochondrial oxidative phosphorylation (OXPHOS) and this metabolic preference is essential for blastocyst maturation. However, molecular mechanisms that regulate establishment of oxidative energy metabolism in TE cells are incompletely understood. Here, we show that conserved transcription factor TEAD4, which is essential for pre-implantation mammalian development, regulates this process by promoting mitochondrial transcription. In developing mouse TE and TE-derived trophoblast stem cells (TSCs), TEAD4 localizes to mitochondria, binds to mitochondrial DNA (mtDNA) and facilitates its transcription by recruiting mitochondrial RNA polymerase (POLRMT). Loss of TEAD4 impairs recruitment of POLRMT, resulting in reduced expression of mtDNA-encoded electron transport chain components, thereby inhibiting oxidative energy metabolism. Our studies identify a novel TEAD4-dependent molecular mechanism that regulates energy metabolism in the TE lineage to ensure mammalian development.
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Affiliation(s)
- Ram P Kumar
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Soma Ray
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Pratik Home
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Biswarup Saha
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Bhaswati Bhattacharya
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Heather M Wilkins
- University of Kansas Alzheimer's Disease Center and the Departments of Neurology, Molecular and Integrative Physiology, and Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Hemantkumar Chavan
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
| | - Avishek Ganguly
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Jessica Milano-Foster
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Arindam Paul
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Partha Krishnamurthy
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
| | - Russell H Swerdlow
- University of Kansas Alzheimer's Disease Center and the Departments of Neurology, Molecular and Integrative Physiology, and Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Soumen Paul
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA .,Institute of Reproductive Health and Regenerative Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
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12
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Chao X, Wang S, Zhao K, Li Y, Williams JA, Li T, Chavan H, Krishnamurthy P, He XC, Li L, Ballabio A, Ni HM, Ding WX. Impaired TFEB-Mediated Lysosome Biogenesis and Autophagy Promote Chronic Ethanol-Induced Liver Injury and Steatosis in Mice. Gastroenterology 2018; 155:865-879.e12. [PMID: 29782848 PMCID: PMC6120772 DOI: 10.1053/j.gastro.2018.05.027] [Citation(s) in RCA: 207] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 04/16/2018] [Accepted: 05/10/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Defects in lysosome function and autophagy contribute to the pathogenesis of alcoholic liver disease. We investigated the mechanisms by which alcohol consumption affects these processes by evaluating the functions of transcription factor EB (TFEB), which regulates lysosomal biogenesis. METHODS We performed studies with GFP-LC3 mice, mice with liver-specific deletion of TFEB, mice with disruption of the transcription factor E3 gene (TFE3-knockout mice), mice with disruption of the Tefb and Tfe3 genes (TFEB and TFE3 double-knockout mice), and Tfebflox/flox albumin cre-negative mice (controls). TFEB was overexpressed from adenoviral vectors or knocked down with small interfering RNAs in mouse livers. Mice were placed on diets of regular ethanol feeding plus an acute binge to induce liver damage (ethanol diet); some mice also were given injections of torin-1, an inhibitor of the kinase activity of the mechanistic target of rapamycin (mTOR). Liver tissues were collected and analyzed by immunohistochemistry, immunoblots, and quantitative real-time polymerase chain reaction to monitor lysosome biogenesis. We analyzed levels of TFEB in liver tissues from patients with alcoholic hepatitis and from healthy donors (controls) by immunohistochemistry. RESULTS Liver tissues from mice on the ethanol diet had lower levels of total and nuclear TFEB compared with control mice, and hepatocytes had decreased lysosome biogenesis and autophagy. Hepatocytes from mice on the ethanol diet had increased translocation of mTOR into lysosomes, resulting in increased mTOR activation. Administration of torin-1 increased liver levels of TFEB and decreased steatosis and liver injury induced by ethanol. Mice that overexpressed TFEB in the liver developed less severe ethanol-induced liver injury and had increased lysosomal biogenesis and mitochondrial bioenergetics compared with mice carrying a control vector. Mice with knockdown of TFEB and TFEB-TFE3 double-knockout mice developed more severe liver injury in response to the ethanol diet than control mice. Liver tissues from patients with alcohol-induced hepatitis had lower nuclear levels of TFEB than control tissues. CONCLUSIONS We found that ethanol feeding plus an acute binge decreased hepatic expression of TFEB, which is required for lysosomal biogenesis and autophagy. Strategies to block mTOR activity or increase levels of TFEB might be developed to protect the liver from ethanol-induced damage.
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Affiliation(s)
- Xiaojuan Chao
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Shaogui Wang
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Katrina Zhao
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Yuan Li
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Jessica A Williams
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Tiangang Li
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Hemantkumar Chavan
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Partha Krishnamurthy
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Xi C He
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Linheng Li
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Andrea Ballabio
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli, Naples, Italy,Medical Genetics, Department of Translational Medicine, Federico II University, Naples, Italy,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Hong-Min Ni
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA,Correspondence to: Wen-Xing Ding, Ph.D., Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, MS 1018, 3901 Rainbow Blvd., Kansas City, Kansas 66160, Phone: 913-588-9813; Fax: 913-588-7501, ; Hong-Min Ni, MD., Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, MS 1018 3901 Rainbow Blvd., Kansas City, Kansas 66160, Phone: 913-588-9813; Fax: 913-588-7501,
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas.
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13
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Kumar D, New J, Vishwakarma V, Joshi R, Enders J, Lin F, Dasari S, Gutierrez WR, Leef G, Ponnurangam S, Chavan H, Ganaden L, Thornton MM, Dai H, Tawfik O, Straub J, Shnayder Y, Kakarala K, Tsue TT, Girod DA, Van Houten B, Anant S, Krishnamurthy P, Thomas SM. Cancer-Associated Fibroblasts Drive Glycolysis in a Targetable Signaling Loop Implicated in Head and Neck Squamous Cell Carcinoma Progression. Cancer Res 2018; 78:3769-3782. [PMID: 29769197 DOI: 10.1158/0008-5472.can-17-1076] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 12/13/2017] [Accepted: 05/11/2018] [Indexed: 12/21/2022]
Abstract
Despite aggressive therapies, head and neck squamous cell carcinoma (HNSCC) is associated with a less than 50% 5-year survival rate. Late-stage HNSCC frequently consists of up to 80% cancer-associated fibroblasts (CAF). We previously reported that CAF-secreted HGF facilitates HNSCC progression; however, very little is known about the role of CAFs in HNSCC metabolism. Here, we demonstrate that CAF-secreted HGF increases extracellular lactate levels in HNSCC via upregulation of glycolysis. CAF-secreted HGF induced basic FGF (bFGF) secretion from HNSCC. CAFs were more efficient than HNSCC in using lactate as a carbon source. HNSCC-secreted bFGF increased mitochondrial oxidative phosphorylation and HGF secretion from CAFs. Combined inhibition of c-Met and FGFR significantly inhibited CAF-induced HNSCC growth in vitro and in vivo (P < 0.001). Our cumulative findings underscore reciprocal signaling between CAF and HNSCC involving bFGF and HGF. This contributes to metabolic symbiosis and a targetable therapeutic axis involving c-Met and FGFR.Significance: HNSCC cancer cells and CAFs have a metabolic relationship where CAFs secrete HGF to induce a glycolytic switch in HNSCC cells and HNSCC cells secrete bFGF to promote lactate consumption by CAFs. Cancer Res; 78(14); 3769-82. ©2018 AACR.
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Affiliation(s)
- Dhruv Kumar
- Department of Otolaryngology, University of Kansas Medical Center, Kansas City, Kansas
| | - Jacob New
- Department of Otolaryngology, University of Kansas Medical Center, Kansas City, Kansas.,Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas
| | - Vikalp Vishwakarma
- Department of Otolaryngology, University of Kansas Medical Center, Kansas City, Kansas
| | - Radhika Joshi
- Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Jonathan Enders
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas
| | - Fangchen Lin
- Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Sumana Dasari
- Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Wade R Gutierrez
- Department of Otolaryngology, University of Kansas Medical Center, Kansas City, Kansas
| | - George Leef
- Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | | | - Hemantkumar Chavan
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Lydia Ganaden
- Department of Otolaryngology, University of Kansas Medical Center, Kansas City, Kansas
| | - Mackenzie M Thornton
- Department of Otolaryngology, University of Kansas Medical Center, Kansas City, Kansas
| | - Hongying Dai
- Health Services & Outcomes Research, Children's Mercy Hospital, Kansas City, Missouri
| | - Ossama Tawfik
- Department of Pathology, University of Kansas Medical Center, Kansas City, Kansas
| | - Jeffrey Straub
- Department of Otolaryngology, University of Kansas Medical Center, Kansas City, Kansas
| | - Yelizaveta Shnayder
- Department of Otolaryngology, University of Kansas Medical Center, Kansas City, Kansas
| | - Kiran Kakarala
- Department of Otolaryngology, University of Kansas Medical Center, Kansas City, Kansas
| | - Terance Ted Tsue
- Department of Otolaryngology, University of Kansas Medical Center, Kansas City, Kansas
| | - Douglas A Girod
- Department of Otolaryngology, University of Kansas Medical Center, Kansas City, Kansas
| | - Bennett Van Houten
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Shrikant Anant
- Department of Surgery, University of Kansas Medical Center, Kansas City, Kansas.,Department of Cancer Biology, University of Kansas Medical Center, Kansas City, Kansas
| | - Partha Krishnamurthy
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Sufi Mary Thomas
- Department of Otolaryngology, University of Kansas Medical Center, Kansas City, Kansas. .,Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas.,Department of Cancer Biology, University of Kansas Medical Center, Kansas City, Kansas
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14
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Tan EP, McGreal SR, Graw S, Tessman R, Koppel SJ, Dhakal P, Zhang Z, Machacek M, Zachara NE, Koestler DC, Peterson KR, Thyfault JP, Swerdlow RH, Krishnamurthy P, DiTacchio L, Apte U, Slawson C. Sustained O-GlcNAcylation reprograms mitochondrial function to regulate energy metabolism. J Biol Chem 2017; 292:14940-14962. [PMID: 28739801 DOI: 10.1074/jbc.m117.797944] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [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: 05/22/2017] [Revised: 07/20/2017] [Indexed: 01/31/2023] Open
Abstract
Dysfunctional mitochondria and generation of reactive oxygen species (ROS) promote chronic diseases, which have spurred interest in the molecular mechanisms underlying these conditions. Previously, we have demonstrated that disruption of post-translational modification of proteins with β-linked N-acetylglucosamine (O-GlcNAcylation) via overexpression of the O-GlcNAc-regulating enzymes O-GlcNAc transferase (OGT) or O-GlcNAcase (OGA) impairs mitochondrial function. Here, we report that sustained alterations in O-GlcNAcylation either by pharmacological or genetic manipulation also alter metabolic function. Sustained O-GlcNAc elevation in SH-SY5Y neuroblastoma cells increased OGA expression and reduced cellular respiration and ROS generation. Cells with elevated O-GlcNAc levels had elongated mitochondria and increased mitochondrial membrane potential, and RNA-sequencing analysis indicated transcriptome reprogramming and down-regulation of the NRF2-mediated antioxidant response. Sustained O-GlcNAcylation in mouse brain and liver validated the metabolic phenotypes observed in the cells, and OGT knockdown in the liver elevated ROS levels, impaired respiration, and increased the NRF2 antioxidant response. Moreover, elevated O-GlcNAc levels promoted weight loss and lowered respiration in mice and skewed the mice toward carbohydrate-dependent metabolism as determined by indirect calorimetry. In summary, sustained elevation in O-GlcNAcylation coupled with increased OGA expression reprograms energy metabolism, a finding that has potential implications for the etiology, development, and management of metabolic diseases.
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Affiliation(s)
- Ee Phie Tan
- From the Departments of Biochemistry and Molecular Biology
| | | | | | | | | | | | - Zhen Zhang
- From the Departments of Biochemistry and Molecular Biology
| | - Miranda Machacek
- From the Departments of Biochemistry and Molecular Biology.,Pathology and Laboratory Medicine, and
| | - Natasha E Zachara
- the Department of Biological Chemistry, The Johns Hopkins University of Medicine, Baltimore, Maryland 21205
| | | | | | | | - Russell H Swerdlow
- Neurology, University of Kansas Medical Center and.,University of Kansas Alzheimer's Disease Center, Kansas City, Kansas 64108 and
| | - Partha Krishnamurthy
- Pharmacology, Toxicology and Therapeutics.,University of Kansas Alzheimer's Disease Center, Kansas City, Kansas 64108 and
| | | | | | - Chad Slawson
- From the Departments of Biochemistry and Molecular Biology, .,University of Kansas Alzheimer's Disease Center, Kansas City, Kansas 64108 and
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15
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Karathedath S, Rajamani BM, Musheer Aalam SM, Abraham A, Varatharajan S, Krishnamurthy P, Mathews V, Velayudhan SR, Balasubramanian P. Role of NF-E2 related factor 2 (Nrf2) on chemotherapy resistance in acute myeloid leukemia (AML) and the effect of pharmacological inhibition of Nrf2. PLoS One 2017; 12:e0177227. [PMID: 28505160 PMCID: PMC5432104 DOI: 10.1371/journal.pone.0177227] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 04/24/2017] [Indexed: 12/30/2022] Open
Abstract
Cytarabine (Ara-C) and Daunorubicin (Dnr) forms the backbone of acute myeloid leukemia (AML) therapy. Drug resistance and toxic side effects pose a major threat to treatment success and hence alternate less toxic therapies are warranted. NF-E2 related factor-2 (Nrf2), a master regulator of antioxidant response is implicated in chemoresistance in solid tumors. However, little is known about the role of Nrf2 in AML chemoresistance and the effect of pharmacological inhibitor brusatol in modulating this resistance. Primary AML samples with high ex-vivo IC50 to Ara-C, ATO, Dnr had significantly high NRF2 RNA expression. Gene-specific knockdown of NRF2 improved sensitivity to these drugs in resistant AML cell lines by decreasing the expression of downstream antioxidant targets of Nrf2 by compromising the cell’s ability to scavenge the ROS. Treatment with brusatol, a pharmacological inhibitor of Nrf2, improved sensitivity to Ara-C, ATO, and Dnr and reduced colony formation capacity. AML cell lines stably overexpressing NRF2 showed increased resistance to ATO, Dnr and Ara-C and increased expression of downstream targets. This study demonstrates that Nrf2 could be an ideal druggable target in AML, more so to the drugs that function through ROS, suggesting the possibility of using Nrf2 inhibitors in combination with chemotherapeutic agents to modulate drug resistance in AML.
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Affiliation(s)
| | | | | | - Ajay Abraham
- Department of Haematology, Christian Medical College, Vellore, India
| | | | - Partha Krishnamurthy
- Department of Pharmacology, Toxicology and Therapeutics, Kansas University Medical Centre, Kansas City, Kansas, United States of America
| | - Vikram Mathews
- Department of Haematology, Christian Medical College, Vellore, India
| | - Shaji Ramachandran Velayudhan
- Department of Haematology, Christian Medical College, Vellore, India
- Centre for Stem Cell Research, Christian Medical College, Vellore, India
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16
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Hanumanthappa N, Krishnamurthy P, Amalraj J, Anchaneyan P, Kumar A, Ramamurthy S. 95P Radiotherapy (RT) for breast cancer patients- clinical implementation of the first ever Tomotherapy-H in a tertiary cancer centre in India. Ann Oncol 2016. [DOI: 10.1093/annonc/mdw575.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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17
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Swayne R, Enoch D, Aliyu S, Crawley C, Krishnamurthy P, Craig J, Follows G, Uttenthal B, Babar J, Sander CR. P266 Outcomes from the introduction of fungal biomarkers to the neutropenic fever pathway in a tertiary haematology department. Thorax 2016. [DOI: 10.1136/thoraxjnl-2016-209333.409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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18
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Hanumanthappa N, Krishnamurthy P, Amalraj J, Anchaneyan P, Kumar A, Ramamurthy S. 95P Radiotherapy (RT) for breast cancer patients- clinical implementation of the first ever Tomotherapy-H in a tertiary cancer centre in India. Ann Oncol 2016. [DOI: 10.1016/s0923-7534(21)00255-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Li J, Wang Y, Matye DJ, Chavan H, Krishnamurthy P, Li F, Li T. Sortilin 1 Modulates Hepatic Cholesterol Lipotoxicity in Mice via Functional Interaction with Liver Carboxylesterase 1. J Biol Chem 2016; 292:146-160. [PMID: 27881673 DOI: 10.1074/jbc.m116.762005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [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: 10/04/2016] [Revised: 11/19/2016] [Indexed: 12/13/2022] Open
Abstract
The liver plays a key role in cholesterol metabolism. Impaired hepatic cholesterol homeostasis causes intracellular free cholesterol accumulation and hepatocyte injury. Sortilin 1 (SORT1) is a lysosomal trafficking receptor that was identified by genome-wide association studies (GWAS) as a novel regulator of cholesterol metabolism in humans. Here we report that SORT1 deficiency protected against cholesterol accumulation-induced liver injury and inflammation in mice. Using an LC-MS/MS-based proteomics approach, we identified liver carboxylesterase 1 (CES1) as a novel SORT1-interacting protein. Mechanistic studies further showed that SORT1 may regulate CES1 lysosomal targeting and degradation and that SORT1 deficiency resulted in higher liver CES1 protein abundance. Previous studies have established an important role of hepatic CES1 in promoting intracellular cholesterol mobilization, cholesterol efflux, and bile acid synthesis. Consistently, high cholesterol atherogenic diet-challenged Sort1 knock-out mice showed less hepatic free cholesterol accumulation, increased bile acid synthesis, decreased biliary cholesterol secretion, and the absence of gallstone formation. SORT1 deficiency did not alter hepatic ceramide and fatty acid metabolism in high cholesterol atherogenic diet-fed mice. Finally, knockdown of liver CES1 in mice markedly increased the susceptibility to high cholesterol diet-induced liver injury and abolished the protective effect against cholesterol lipotoxicity in Sort1 knock-out mice. In summary, this study identified a novel SORT1-CES1 axis that regulates cholesterol-induced liver injury, which provides novel insights that improve our current understanding of the molecular links between SORT1 and cholesterol metabolism. This study further suggests that therapeutic inhibition of SORT1 may be beneficial in improving hepatic cholesterol homeostasis in metabolic and inflammatory liver diseases.
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Affiliation(s)
- Jibiao Li
- From the Department of Pharmacology, Toxicology and Therapeutics, Kansas University Medical Center, Kansas City, Kansas 66160 and
| | - Yifeng Wang
- From the Department of Pharmacology, Toxicology and Therapeutics, Kansas University Medical Center, Kansas City, Kansas 66160 and
| | - David J Matye
- From the Department of Pharmacology, Toxicology and Therapeutics, Kansas University Medical Center, Kansas City, Kansas 66160 and
| | - Hemantkumar Chavan
- From the Department of Pharmacology, Toxicology and Therapeutics, Kansas University Medical Center, Kansas City, Kansas 66160 and
| | - Partha Krishnamurthy
- From the Department of Pharmacology, Toxicology and Therapeutics, Kansas University Medical Center, Kansas City, Kansas 66160 and
| | - Feng Li
- the Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030
| | - Tiangang Li
- From the Department of Pharmacology, Toxicology and Therapeutics, Kansas University Medical Center, Kansas City, Kansas 66160 and
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Bhushan B, Chavan H, Borude P, Xie Y, Du K, McGill MR, Lebofsky M, Jaeschke H, Krishnamurthy P, Apte U. Dual Role of Epidermal Growth Factor Receptor in Liver Injury and Regeneration after Acetaminophen Overdose in Mice. Toxicol Sci 2016; 155:363-378. [PMID: 28123000 DOI: 10.1093/toxsci/kfw213] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Epidermal growth factor receptor (EGFR) plays a crucial role in hepatocyte proliferation. Its role in acetaminophen (APAP)-mediated hepatotoxicity and subsequent liver regeneration is completely unknown. Role of EGFR after APAP-overdose in mice was studied using pharmacological inhibition strategy. Rapid, sustained and dose-dependent activation of EGFR was noted after APAP-treatment in mice, which was triggered by glutathione depletion. EGFR-activation was also observed in primary human hepatocytes after APAP-treatment, preceding elevation of toxicity markers. Treatment of mice with an EGFR-inhibitor (EGFRi), Canertinib, 1h post-APAP resulted in robust inhibition of EGFR-activation and a striking reduction in APAP-induced liver injury. Metabolic activation of APAP, formation of APAP-protein adducts, APAP-mediated JNK-activation and its mitochondrial translocation were not altered by EGFRi. Interestingly, EGFR rapidly translocated to mitochondria after APAP-treatment. EGFRi-treatment abolished mitochondrial EGFR activity, prevented APAP-mediated mitochondrial dysfunction/oxidative-stress and release of endonucleases from mitochondria, which are responsible for DNA-damage/necrosis. Treatment with N-acetylcysteine (NAC), 4h post-APAP in mice did not show any protection but treatment of EGFRi in combination with NAC showed decrease in liver injury. Finally, delayed treatment with EGFRi, 12-h post-APAP, did not alter peak injury but caused impairment of liver regeneration resulting in sustained injury and decreased survival after APAP overdose in mice. Impairment of regeneration was due to inhibition of cyclinD1 induction and cell cycle arrest. Our study has revealed a new dual role of EGFR both in initiation of APAP-injury and in stimulation of subsequent compensatory regeneration after APAP-overdose.
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Affiliation(s)
- Bharat Bhushan
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Hemantkumar Chavan
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Prachi Borude
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Yuchao Xie
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Kuo Du
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Mitchell R McGill
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Margitta Lebofsky
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Hartmut Jaeschke
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Partha Krishnamurthy
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Udayan Apte
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160
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21
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Wang Y, Ding Y, Li J, Chavan H, Matye D, Ni HM, Chiang JY, Krishnamurthy P, Ding WX, Li T. Targeting the Enterohepatic Bile Acid Signaling Induces Hepatic Autophagy via a CYP7A1-AKT-mTOR Axis in Mice. Cell Mol Gastroenterol Hepatol 2016; 3:245-260. [PMID: 28275691 PMCID: PMC5331786 DOI: 10.1016/j.jcmgh.2016.10.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [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: 05/27/2016] [Accepted: 10/13/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Hepatic cholesterol accumulation and autophagy defects contribute to hepatocyte injury in fatty liver disease. Bile acid synthesis is a major pathway for cholesterol catabolism in the liver. This study aims to understand the molecular link between cholesterol and bile acid metabolism and hepatic autophagy activity. METHODS The effects of cholesterol and cholesterol 7α-hydroxylase (CYP7A1) expression on autophagy and lysosome function were studied in cell models. The effects and mechanism of disrupting enterohepatic bile acid circulation on hepatic autophagy were studied in mice. RESULTS The results first showed differential regulation of hepatic autophagy by free cholesterol and cholesterol ester, whereby a modest increase of cellular free cholesterol, but not cholesterol ester, impaired lysosome function and caused marked autolysosome accumulation. We found that CYP7A1 induction, either by cholestyramine feeding in mice or adenovirus-mediated CYP7A1 expression in hepatocytes, caused strong autophagy induction. Mechanistically, we showed that CYP7A1 expression markedly attenuated growth factor/AKT signaling activation of mechanistic target of rapamycin (mTOR), but not amino acid signaling to mTOR in vitro and in vivo. Metabolomics analysis further found that CYP7A1 induction not only decreased hepatic cholesterol but also altered phospholipid and sphingolipid compositions. Collectively, these results suggest that CYP7A1 induction interferes with growth factor activation of AKT/mTOR signaling possibly by altering membrane lipid composition. Finally, we showed that cholestyramine feeding restored impaired hepatic autophagy and improved metabolic homeostasis in Western diet-fed mice. CONCLUSIONS This study identified a novel CYP7A1-AKT-mTOR signaling axis that selectively induces hepatic autophagy, which helps improve hepatocellular integrity and metabolic homeostasis.
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Key Words
- 4EBP-1, eukaryotic translation initiation factor 4E-binding protein 1
- ACAT, acyl-CoA:cholesterol acyltransferase
- CE, cholesterol ester
- CQ, chloroquine
- CYP7A1, cholesterol 7α-hydroxylase
- ChTM, cholestyramine
- Cholesterol
- Cholestyramine
- DIO, diet-induced obesity
- ER, endoplasmic reticulum
- FC, free cholesterol
- Fatty Liver
- GSK3β, glycogen synthase kinase 3β
- HMGCR, HMG-CoA reductase
- LC3, microtubule-associated protein 1A/1B-light chain 3
- LDLR, low-density lipoprotein receptor
- LMP, lysosome membrane permeabilization
- Nuclear Receptor
- PI, phosphatidylinositol
- PM, plasma membrane
- S6, tibosomal protein S6
- SREBP, sterol response element binding protein
- mRNA, messenger RNA
- mTOR, the nutrient sensing mechanistic target of rapamycin
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Affiliation(s)
- Yifeng Wang
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Yifeng Ding
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Jibiao Li
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Hemantkumar Chavan
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - David Matye
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Hong-Min Ni
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - John Y.L. Chiang
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio
| | - Partha Krishnamurthy
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Tiangang Li
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas,Correspondence Address correspondence to: Tiangang Li, PhD, Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, Kansas 66160. fax: (913) 588-7501.Department of PharmacologyToxicology and TherapeuticsUniversity of Kansas Medical Center3901 Rainbow BoulevardKansas CityKansas 66160
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22
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Du K, Ramachandran A, Weemhoff JL, Chavan H, Xie Y, Krishnamurthy P, Jaeschke H. Editor's Highlight: Metformin Protects Against Acetaminophen Hepatotoxicity by Attenuation of Mitochondrial Oxidant Stress and Dysfunction. Toxicol Sci 2016; 154:214-226. [PMID: 27562556 DOI: 10.1093/toxsci/kfw158] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [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: 02/07/2023] Open
Abstract
Overdose of acetaminophen (APAP) causes severe liver injury and even acute liver failure in both mice and human. A recent study by Kim et al. (2015, Metformin ameliorates acetaminophen hepatotoxicity via Gadd45β-dependent regulation of JNK signaling in mice. J. Hepatol. 63, 75-82) showed that metformin, a first-line drug to treat type 2 diabetes mellitus, protected against APAP hepatotoxicity in mice. However, its exact protective mechanism has not been well clarified. To investigate this, C57BL/6J mice were treated with 400 mg/kg APAP and 350 mg/kg metformin was given 0.5 h pre- or 2 h post-APAP. Our data showed that pretreatment with metformin protected against APAP hepatotoxicity, as indicated by the over 80% reduction in plasma alanine aminotransferase (ALT) activities and significant decrease in centrilobular necrosis. Metabolic activation of APAP, as indicated by glutathione depletion and APAP-protein adducts formation, was also slightly inhibited. However, 2 h post-treatment with metformin still reduced liver injury by 50%, without inhibition of adduct formation. Interestingly, neither pre- nor post-treatment of metformin inhibited c-jun N-terminal kinase (JNK) activation or its mitochondrial translocation. In contrast, APAP-induced mitochondrial oxidant stress and dysfunction were greatly attenuated in these mice. In addition, mice with 2 h post-treatment with metformin also showed significant inhibition of complex I activity, which may contribute to the decreased mitochondrial oxidant stress. Furthermore, the protection was reproduced in JNK activation-absent HepaRG cells treated with 20 mM APAP followed by 0.5 or 1 mM metformin 6 h later, confirming JNK-independent protection mechanisms. Thus, metformin protects against APAP hepatotoxicity by attenuating the mitochondrial oxidant stress and subsequent mitochondrial dysfunction, and may be a potential therapeutic option for APAP overdose patients.
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Affiliation(s)
- Kuo Du
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Anup Ramachandran
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - James L Weemhoff
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Hemantkumar Chavan
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Yuchao Xie
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Partha Krishnamurthy
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
| | - Hartmut Jaeschke
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas
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23
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Shen H, Liu T, Jiang H, Titsch C, Taylor K, Kandoussi H, Qiu X, Chen C, Sukrutharaj S, Kuit K, Mintier G, Krishnamurthy P, Fancher RM, Zeng J, Rodrigues AD, Marathe P, Lai Y. Cynomolgus Monkey as a Clinically Relevant Model to Study Transport Involving Renal Organic Cation Transporters: In Vitro and In Vivo Evaluation. Drug Metab Dispos 2015; 44:238-49. [DOI: 10.1124/dmd.115.066852] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/19/2015] [Indexed: 01/12/2023] Open
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Lockwood DN, Krishnamurthy P, Pannikar V, Penna G. Reply to the role of contact tracing and prevention strategies in the interruption of leprosy transmission. LEPROSY REV 2015. [DOI: 10.47276/lr.86.1.124] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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25
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Lockwood DNJ, Krishnamurthy P, Pannikar V, Penna G. Reply to the role of contact tracing and prevention strategies in the interruption of leprosy transmission. LEPROSY REV 2015; 86:124-125. [PMID: 26065157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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26
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Chavan H, Li F, Tessman R, Mickey K, Dorko K, Schmitt T, Kumer S, Gunewardena S, Gaikwad N, Krishnamurthy P. Functional coupling of ATP-binding cassette transporter Abcb6 to cytochrome P450 expression and activity in liver. J Biol Chem 2015; 290:7871-86. [PMID: 25623066 DOI: 10.1074/jbc.m114.605386] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Although endogenous mechanisms that negatively regulate cytochrome P450 (P450) monooxygenases in response to physiological and pathophysiological signals are not well understood, they are thought to result from alterations in the level of endogenous metabolites, involved in maintaining homeostasis. Here we show that homeostatic changes in hepatic metabolite profile in Abcb6 (mitochondrial ATP-binding cassette transporter B6) deficiency results in suppression of a specific subset of hepatic P450 activity. Abcb6 null mice are more susceptible to pentobarbital-induced sleep and zoxazolamine-induced paralysis, secondary to decreased expression and activity of Cyp3a11 and Cyp2b10. The knock-out mice also show decrease in both basal and xeno-inducible expression and activity of a subset of hepatic P450s that appear to be related to changes in hepatic metabolite profile. These data, together with the observation that liver extracts from Abcb6-deficient mice suppress P450 expression in human primary hepatocytes, suggest that this mouse model may provide an opportunity to understand the physiological signals and the mechanisms involved in negative regulation of P450s.
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Affiliation(s)
| | - Feng Li
- From the Departments of Pharmacology, Toxicology and Therapeutics
| | - Robert Tessman
- From the Departments of Pharmacology, Toxicology and Therapeutics
| | - Kristen Mickey
- From the Departments of Pharmacology, Toxicology and Therapeutics
| | - Kenneth Dorko
- From the Departments of Pharmacology, Toxicology and Therapeutics, the Cell Isolation Core, University of Kansas Medical Center, Kansas City, Kansas 66160 and
| | | | | | | | - Nilesh Gaikwad
- the Departments of Nutrition and Environmental Toxicology and the West Coast Metabolomics Center, University of California, Davis, California 95616
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Krishnamurthy P, Khare A, Klenck SC, Norton PJ. Survival Modeling of Discontinuation From Psychotherapy: A Consumer Decision-Making Perspective. J Clin Psychol 2014; 71:199-207. [DOI: 10.1002/jclp.22122] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Mackie A, Vaughan E, Verma S, Krishnamurthy P, Ramirez V, Ito A, Abramova T, Misener S, Kishore R. Chronic ethanol consumption impacts post-AMI cardiac function and modulates gene expression in cardiac cell types through alteration of histone 3 lysine 79 methylation. Alcohol 2013. [DOI: 10.1016/j.alcohol.2013.09.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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29
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Chavan H, Khan MMT, Tegos G, Krishnamurthy P. Efficient purification and reconstitution of ATP binding cassette transporter B6 (ABCB6) for functional and structural studies. J Biol Chem 2013; 288:22658-69. [PMID: 23792964 DOI: 10.1074/jbc.m113.485284] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [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: 12/21/2022] Open
Abstract
The mitochondrial ATP binding cassette transporter ABCB6 has been associated with a broad range of physiological functions, including growth and development, therapy-related drug resistance, and the new blood group system Langereis. ABCB6 has been proposed to regulate heme synthesis by shuttling coproporphyrinogen III from the cytoplasm into the mitochondria. However, direct functional information of the transport complex is not known. To understand the role of ABCB6 in mitochondrial transport, we developed an in vitro system with pure and active protein. ABCB6 overexpressed in HEK293 cells was solubilized from mitochondrial membranes and purified to homogeneity. Purified ABCB6 showed a high binding affinity for MgATP (Kd = 0.18 μM) and an ATPase activity with a Km of 0.99 mM. Reconstitution of ABCB6 into liposomes allowed biochemical characterization of the ATPase including (i) substrate-stimulated ATPase activity, (ii) transport kinetics of its proposed endogenous substrate coproporphyrinogen III, and (iii) transport kinetics of substrates identified using a high throughput screening assay. Mutagenesis of the conserved lysine to alanine (K629A) in the Walker A motif abolished ATP hydrolysis and substrate transport. These results suggest a direct interaction between mitochondrial ABCB6 and its transport substrates that is critical for the activity of the transporter. Furthermore, the simple immunoaffinity purification of ABCB6 to near homogeneity and efficient reconstitution of ABCB6 into liposomes might provide the basis for future studies on the structure/function of ABCB6.
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Affiliation(s)
- Hemantkumar Chavan
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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30
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Polireddy K, Khan MMT, Chavan H, Young S, Ma X, Waller A, Garcia M, Perez D, Chavez S, Strouse JJ, Haynes MK, Bologa CG, Oprea TI, Tegos GP, Sklar LA, Krishnamurthy P. A novel flow cytometric HTS assay reveals functional modulators of ATP binding cassette transporter ABCB6. PLoS One 2012; 7:e40005. [PMID: 22808084 PMCID: PMC3393737 DOI: 10.1371/journal.pone.0040005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 05/30/2012] [Indexed: 11/18/2022] Open
Abstract
ABCB6 is a member of the adenosine triphosphate (ATP)-binding cassette family of transporter proteins that is increasingly recognized as a relevant physiological and therapeutic target. Evaluation of modulators of ABCB6 activity would pave the way toward a more complete understanding of the significance of this transport process in tumor cell growth, proliferation and therapy-related drug resistance. In addition, this effort would improve our understanding of the function of ABCB6 in normal physiology with respect to heme biosynthesis, and cellular adaptation to metabolic demand and stress responses. To search for modulators of ABCB6, we developed a novel cell-based approach that, in combination with flow cytometric high-throughput screening (HTS), can be used to identify functional modulators of ABCB6. Accumulation of protoporphyrin, a fluorescent molecule, in wild-type ABCB6 expressing K562 cells, forms the basis of the HTS assay. Screening the Prestwick Chemical Library employing the HTS assay identified four compounds, benzethonium chloride, verteporfin, tomatine hydrochloride and piperlongumine, that reduced ABCB6 mediated cellular porphyrin levels. Validation of the identified compounds employing the hemin-agarose affinity chromatography and mitochondrial transport assays demonstrated that three out of the four compounds were capable of inhibiting ABCB6 mediated hemin transport into isolated mitochondria. However, only verteporfin and tomatine hydrochloride inhibited ABCB6's ability to compete with hemin as an ABCB6 substrate. This assay is therefore sensitive, robust, and suitable for automation in a high-throughput environment as demonstrated by our identification of selective functional modulators of ABCB6. Application of this assay to other libraries of synthetic compounds and natural products is expected to identify novel modulators of ABCB6 activity.
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Affiliation(s)
- Kishore Polireddy
- Department of Pharmacology, Toxicology, and Therapeutics, The University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Mohiuddin Md. Taimur Khan
- Center for Molecular Discovery, University of New Mexico, Albuquerque, New Mexico, United States of America
- Division of Biocomputing, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, United States of America
- Department of Pathology, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Hemantkumar Chavan
- Department of Pharmacology, Toxicology, and Therapeutics, The University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Susan Young
- Center for Molecular Discovery, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Xiaochao Ma
- Department of Pharmacology, Toxicology, and Therapeutics, The University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Anna Waller
- Center for Molecular Discovery, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Matthew Garcia
- Center for Molecular Discovery, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Dominique Perez
- Center for Molecular Discovery, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Stephanie Chavez
- Center for Molecular Discovery, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Jacob J. Strouse
- Center for Molecular Discovery, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Mark K. Haynes
- Center for Molecular Discovery, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Cristian G. Bologa
- Center for Molecular Discovery, University of New Mexico, Albuquerque, New Mexico, United States of America
- Division of Biocomputing, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, United States of America
| | - Tudor I. Oprea
- Center for Molecular Discovery, University of New Mexico, Albuquerque, New Mexico, United States of America
- Division of Biocomputing, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, United States of America
| | - George P. Tegos
- Center for Molecular Discovery, University of New Mexico, Albuquerque, New Mexico, United States of America
- Department of Pathology, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Dermatology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Larry A. Sklar
- Center for Molecular Discovery, University of New Mexico, Albuquerque, New Mexico, United States of America
- Division of Biocomputing, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, United States of America
- Department of Pathology, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Partha Krishnamurthy
- Department of Pharmacology, Toxicology, and Therapeutics, The University of Kansas Medical Center, Kansas City, Kansas, United States of America
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Chavan H, Krishnamurthy P. Polycyclic aromatic hydrocarbons (PAHs) mediate transcriptional activation of the ATP binding cassette transporter ABCB6 gene via the aryl hydrocarbon receptor (AhR). J Biol Chem 2012; 287:32054-68. [PMID: 22761424 DOI: 10.1074/jbc.m112.371476] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Liver is endowed with a mechanism to induce hepatic cytochromes P450 (CYP450s) in response to therapeutic drugs and environmental contaminants, leading to increased detoxification and elimination of the xenobiotics. Each CYP450 is composed of an apoprotein moiety and a heme prosthetic group, which is required for CYP450 activity. Thus, under conditions of CYP450 induction, there is a coordinate increase in heme biosynthesis to compensate for the increased expression of CYP450s. ABCB6, a mitochondrial ATP binding cassette transporter, which regulates coproporphyrinogen transport from the cytoplasm into the mitochondria to complete heme biosynthesis, represents a previously unrecognized rate-limiting step in heme biosynthesis. However, it is not known if exposure to drugs and environmental contaminants induces ABCB6 expression, to assure an adequate and apparently coordinated supply of heme for the generation of functional cytochrome holoprotein. In the present study, we demonstrate that polycyclic aromatic hydrocarbons (PAHs), the widely distributed environmental toxicants shown to induce porphyrin accumulation causing hepatic porphyria, up-regulate ABCB6 expression in both mice and humans. Using siRNA technology and Abcb6 knock-out mice, we demonstrate that PAH-mediated increase in hepatic porphyrins is compromised in the absence of ABCB6. Moreover, in vivo studies in aryl hydrocarbon receptor (AhR) knock-out mice demonstrate that PAH induction of ABCB6 is mediated by AhR. Promoter activation studies combined with electrophoretic mobility shift assay and chromatin immunoprecipitation assay demonstrate direct interactions between the AhR binding sites in the ABCB6 promoter and the AhR receptor, implicating drug activation mechanisms for ABCB6 similar to those found in inducible cytochrome P450s. These studies are the first to describe direct transcriptional activation of both mouse and human ABCB6 by xenobiotics.
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Affiliation(s)
- Hemantkumar Chavan
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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Nagi W, Lim Z, Krishnamurthy P, Potter V, Tindell V, Reiff-Zall L, Abdullah A, Lea N, Kenyon M, Marsh J, Ho A, Mufti G, Pagliuca A. Alemtuzumab based reduced intensity conditioning allogeneic haematopoietic stem cell transplantation for myelofibrosis. Leuk Res 2011; 35:998-1000. [DOI: 10.1016/j.leukres.2011.02.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 02/10/2011] [Accepted: 02/14/2011] [Indexed: 11/17/2022]
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Pinto R, Potter V, Tindell V, Krishnamurthy P, Marsh J, Ireland R, Pagliuca A, Mufti G, Lim Z. 332 Outcomes of reduced intensity conditioning HSCT for lower-risk MDS: King's college hospital experience. Leuk Res 2011. [DOI: 10.1016/s0145-2126(11)70334-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Pandav CS, Krishnamurthy P, Sankar R, Yadav K, Palanivel C, Karmarkar MG. A review of tracking progress towards elimination of iodine deficiency disorders in Tamil Nadu, India. Indian J Public Health 2011; 54:120-5. [PMID: 21245580 DOI: 10.4103/0019-557x.75733] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Iodine deficiency disorders (IDD) are significant health problem in India. But there is dearth of regional/state level information for the same. OBJECTIVE This study was designed to study the current status of IDD in Tamil Nadu. MATERIALS AND METHODS A cross-sectional community-based survey was conducted in the state of Tamil Nadu. The study population was children in the age group of 6-12 years and the probability proportional to size 30 cluster methodology was used for sample selection. The parameters studied were prevalence of goiter, urinary iodine excretion, and iodine content in salt at the household level. RESULTS A total of 1230 children aged between 6 and 12 years were studied. The total goiter rate was 13.5% (95% CI: 11.1-14.9). The median urinary iodine excretion was found to be 89.5 μg/L (range, 10.2-378 μg/L). The 56% of the urinary iodine excretion values were <100 μg/L. The proportion of households consuming adequately iodized salt (iodine content ≥ 15 parts per million) was 18.2% (95% CI: 16.1-20.5). CONCLUSION The total goiter rate of 13.5% and median urinary iodine excretion of 89.5 μg/L is indicative of iodine deficiency in Tamil Nadu.
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Affiliation(s)
- Chandrakant S Pandav
- Centre for Community Medicine, All India Institute of Medical Sciences, International Council for Control of Iodine Deficiency Disorders, New Delhi, India.
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Krishnamurthy P, D. Schuetz J. The Role of ABCG2 and ABCB6 in Porphyrin Metabolism and Cell Survival. Curr Pharm Biotechnol 2011; 12:647-55. [DOI: 10.2174/138920111795163995] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Accepted: 04/22/2010] [Indexed: 11/22/2022]
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Chavan H, Oruganti M, Krishnamurthy P. The ATP-binding cassette transporter ABCB6 is induced by arsenic and protects against arsenic cytotoxicity. Toxicol Sci 2011; 120:519-28. [PMID: 21266531 DOI: 10.1093/toxsci/kfr008] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Arsenic, an environmental carcinogen, remains a major public health problem. Arsenic damages biological systems through multiple mechanisms, including the generation of reactive oxygen species. ABCB6 is an ATP-binding cassette transporter that is highly expressed in cells resistant to arsenic. We have recently demonstrated that ABCB6 expression protects against cellular stressors. In the present study, we evaluated the significance of ABCB6 expression to arsenic toxicity both in mice and in cell culture. We show that sodium arsenite induces ABCB6 expression in a dose-dependent manner both in mice fed sodium arsenite in drinking water and in cells exposed to sodium arsenite in vitro. Arsenite-induced ABCB6 expression was transcriptionally regulated, but this induction was not mediated by the redox-sensitive transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf2). We demonstrate that, in HepG2 and Hep3B cells, knockdown of ABCB6 expression using ABCB6-specific small interfering RNA sensitized the cells to arsenite toxicity. In contrast, stable overexpression of ABCB6 conferred a strong survival advantage toward arsenite-induced oxidative stress. Collectively, these results, obtained by both loss of function and gain of function analysis, suggest that ABCB6 expression in response to sodium arsenite might be an endogenous protective mechanism activated to protect cells against arsenite-induced oxidative stress.
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Affiliation(s)
- Hemantkumar Chavan
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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Abstract
C-reactive protein (CRP), an inflammatory marker of cardiovascular risk, is often elevated in major depressive disorder (MDD). The magnitude and consistency of this elevation have not been previously characterized in premenopausal women with MDD. The aim of the study was to prospectively assess plasma CRP levels, body composition, endocrine and metabolic parameters, and depressive status in premenopausal women with MDD (n=77) and controls (n=41), aged 21 to 45. Women were enrolled in a 12-month, controlled study of bone turnover, the P.O.W.E.R. ( Premenopausal, Osteoporosis, Women, Al Endronate, Dep Ression) Study. Blood samples were taken at Baseline, Month 6, and Month 12. Most subjects with MDD were in clinical remission. These women tended to have consistently higher CRP levels than controls over 12 months (p=0.077). BMI was positively related to log[CRP] in women with MDD only. Nine women with MDD had CRP levels greater than 10 mg/l, a value associated with a very high cardiovascular risk. This subset was obese and had significantly higher triglycerides, total cholesterol, LDL-cholesterol, fasting insulin, and HOMA-IR than the rest of women with MDD. The variations in CRP levels over time were high (intra- and inter-individual coefficients of variations of approximately 30-50% and approximately 70-140%, respectively). No control had CRP levels greater than 10 mg/l. Depression was associated with increased plasma CRP in women with MDD. The clinical significance of abnormal plasma CRP for cardiovascular risk needs to be assessed in large prospective studies of women with depression.
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Affiliation(s)
- G Cizza
- Clinical Endocrine Section, Clinical Endocrinology Branch, NIDDK, NIH, DHHS, Bethesda, MD 20892-1613, USA.
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Lynch J, Fukuda Y, Krishnamurthy P, Du G, Schuetz JD. Cell survival under stress is enhanced by a mitochondrial ATP-binding cassette transporter that regulates hemoproteins. Cancer Res 2009; 69:5560-7. [PMID: 19549895 DOI: 10.1158/0008-5472.can-09-0078] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The ATP-binding cassette (ABC) transporter ABCB6 localizes to the mitochondria, where it imports porphyrins and up-regulates de novo porphyrin synthesis. If ABCB6 also increases the intracellular heme concentration, it may broadly affect the regulation and physiology of cellular hemoproteins. We tested whether the ability of ABCB6 to accelerate de novo porphyrin biosynthesis alters mitochondrial and extramitochondrial heme levels. ABCB6 overexpression increased the quantity of cytosolic heme but did not affect mitochondrial heme levels. We then tested whether the increased extramitochondrial heme would increase the concentration and/or activity of cellular hemoproteins (hemoglobin, catalase, and cytochrome c oxidase). ABCB6 overexpression increased the activity and quantity of hemoproteins found in several subcellular compartments, and reduction of ABCB6 function (by small interfering RNA or knockout) reversed these findings. In complementary studies, suppression of ABCB6 expression sensitized cells to stress induced by peroxide and cyanide, whereas overexpression of ABCB6 protected against both stressors. Our findings show that the ability of ABCB6 to increase cytosolic heme levels produces phenotypic changes in hemoproteins that protect cells from certain stresses. Collectively, these findings have implications for the health and survival of both normal and abnormal cells, which rely on heme for multiple cellular processes.
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Affiliation(s)
- John Lynch
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-3678, USA
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Oruganti M, Krishnamurthy P. Interaction of Abcb6 with Cytochrome P450s. FASEB J 2009. [DOI: 10.1096/fasebj.23.1_supplement.688.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Krishnamurthy P, Schwab M, Takenaka K, Nachagari D, Morgan J, Leslie M, Du W, Boyd K, Cheok M, Nakauchi H, Marzolini C, Kim RB, Poonkuzhali B, Schuetz E, Evans W, Relling M, Schuetz JD. Transporter-mediated protection against thiopurine-induced hematopoietic toxicity. Cancer Res 2008; 68:4983-9. [PMID: 18593894 DOI: 10.1158/0008-5472.can-07-6790] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Thiopurines are effective immunosuppressants and anticancer agents, but intracellular accumulation of their active metabolites (6-thioguanine nucleotides, 6-TGN) causes dose-limiting hematopoietic toxicity. Thiopurine S-methyltransferase deficiency is known to exacerbate thiopurine toxicity. However, many patients are highly sensitive to thiopurines for unknown reasons. We show that multidrug-resistance protein 4 (Mrp4) is abundant in myeloid progenitors and tested the role of the Mrp4, an ATP transporter of monophosphorylated nucleosides, in this unexplained thiopurine sensitivity. Mrp4-deficient mice experienced Mrp4 gene dosage-dependent toxicity caused by accumulation of 6-TGNs in their myelopoietic cells. Therefore, Mrp4 protects against thiopurine-induced hematopoietic toxicity by actively exporting thiopurine nucleotides. We then identified a single-nucleotide polymorphism (SNP) in human MRP4 (rs3765534) that dramatically reduces MRP4 function by impairing its cell membrane localization. This SNP is common (>18%) in the Japanese population and indicates that the increased sensitivity of some Japanese patients to thiopurines may reflect the greater frequency of this MRP4 SNP.
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Affiliation(s)
- Partha Krishnamurthy
- Department of Pharmaceutical Sciences and Animal Resource Center, St Jude Children's Research Hospital, Memphis, Tenessee 38105, USA
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Kroger A, Pannikar V, Htoon MT, Jamesh A, Katoch K, Krishnamurthy P, Ramalingam K, Jianping S, Jadhav V, Gupte MD, Manickam P. International open trial of uniform multi-drug therapy regimen for 6 months for all types of leprosy patients: rationale, design and preliminary results. Trop Med Int Health 2008; 13:594-602. [PMID: 18346026 DOI: 10.1111/j.1365-3156.2008.02045.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To describe the rationale, design and preliminary results of an open trial of 6 months uniform multi-drug therapy (U-MDT) for all types of leprosy patients assuming a cumulative relapse rate not exceeding 5% over 5 years of follow-up. METHODS We intended to recruit 2500 patients each in multi-bacillary (MB) and pauci-bacillary (PB) groups from India (five centres) and China (two centres). Standardized clinical criteria were used to assess skin lesions in the field. RESULTS A total of 2912 patients enrolled from November 2003 to May 2007 (India, 2746; China, 166). MB patients constituted 39% and 3% had grade 2 disability. During follow-up, 27 patients (0.9%) developed new lesions. Of these, 78% were on account of reactions. Six patients had clinically confirmed relapse. Clofazimine-related skin pigmentation was short-lived and was acceptable to patients. We analysed data for clinical status of skin lesions. About 2.9% of patients were lost to follow-up; 85.9% completed treatment, of whom 19% had inactive skin lesions. PB patients responded better than MB patients (27%vs. 6%; P < 0.001). At the end of the first (n = 2013) and second year (n = 807) of follow-up post-U-MDT, in 49% and 46% patients, lesions were inactive, respectively (59% and 57% in PB, 37% and 28% in MB; P < 0.001). CONCLUSION U-MDT appears to be promising with respect to clinical status of skin lesions.
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Affiliation(s)
- Axel Kroger
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR), WHO, Switzerland
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Krishnamurthy P, Romagni P, Torvik S, Gold PW, Charney DS, Detera-Wadleigh S, Cizza G. Glucocorticoid receptor gene polymorphisms in premenopausal women with major depression. Horm Metab Res 2008; 40:194-8. [PMID: 18246526 DOI: 10.1055/s-2007-1004541] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Glucocorticoid receptor gene polymorphisms are associated with glucocorticoid hypersensitivity and visceral obesity. Perturbations in HPA axis sensitivity to glucocorticoids implicated in the pathogenesis of major depression may result from functional alterations in the glucocorticoid receptor gene. We 1) examined the prevalence of genotype distribution of specific polymorphisms of the glucocorticoid receptor gene (Bcl1, N363S, rs33388, rs33389) in a subset of women from the P.O.W.E.R. Study (which enrolled 21- to 45-year-old premenopausal women with major depression and healthy controls) and 2) explored whether such polymorphisms were associated with visceral obesity and insulin resistance. Women with major depression had a higher body mass index, a higher waist:hip ratio, and more body fat than did controls. No differences were observed in plasma and urinary cortisol or in insulin sensitivity. The G/G genotype of the Bcl1 polymorphism was significantly more common (p<0.03) in women with major depression (n=52) than in controls (n=29). In addition, GG homozygotes (depressed n=10; controls n=2) had higher waist:hip ratios than did non-GG carriers (p<0.02). N363S, rs33388, and rs33389 polymorphisms were not different between groups. In conclusion, premenopausal women with both major depression and the GG genotype of the Bcl1 polymorphism had greater abdominal obesity compared with non-GG carriers.
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Affiliation(s)
- P Krishnamurthy
- Clinical Endocrinology Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA
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Madhavan K, Vijayakumaran P, Ramachandran L, Manickam C, Rajmohan R, Mathew J, Krishnamurthy P. Sustainable leprosy related disability care within integrated general health services: findings from Salem District, India. LEPROSY REV 2007; 78:353-361. [PMID: 18309709] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The main focus of leprosy control has been case detection and treatment delivery with relative neglect of prevention of disability. Absence of reliable data and lack of research have added to the problem. This raised concerns about the capacity of the general health system to address the needs of people living with leprosy-related disabilities. In this prospective study appropriate services for people living with leprosy-related disabilities were introduced in the form of self-care training, guidance and monitoring by the general health staff facilitated by a non-governmental organisation leprosy centre in a district in south India with a population of 3.1 million (estimated in 2005). The staff identified 1232 people with leprosy-related disabilities and trained them in self-care. Follow-up assessments indicated that 86% were found to be practising self-care regularly and all the 239 general health workers were found to be actively involved. The most heartening outcome was the healing of plantar ulcers in 70% of people at the 1-year follow up. This intervention is sustainable because of the simplicity of the procedures and the involvement of all health staff including supervisors.
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Sunkad M, Jha SK, Krishnamurthy P. A REVIEW OF THE TREND IN LEPROSY NEW CASE DETECTION IN AN INDIAN VILLAGE OVER 23 YEARS. LEPROSY REV 2007. [DOI: 10.47276/lr.78.2.171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Sunkad M, Jha SK, Krishnamurthy P. A review of the trend in leprosy new case detection in an Indian village over 23 years. LEPROSY REV 2007; 78:171-2. [PMID: 17824493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
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Abstract
Heme, a complex of iron and protoporphyrin IX (PPIX), senses and utilizes oxygen in nearly all living cells. It is an essential component of various hemoproteins, including those involved in oxygen transport and storage (hemoglobin, myoglobin), electron transfer, drug and steroid metabolism (cytochromes), and signal transduction (nitric oxide synthases, guanylate cyclases). The movement of heme into and within cells was thought to occur by diffusion. However, the chemical properties of heme make diffusion too slow to keep pace with biological processes, and accumulation of heme and its pre-cursor porphyrins in membranes can be deleterious. Due to pro-oxidant effects, heme may cause damage to DNA, proteins, the cytoskeleton and membrane lipids. The intracellular localization and concentrations of protoporphyrins and heme are tightly regulated, and elevated levels are linked to pathologic conditions (e.g., anemia, lead poisoning, thalassemias) associated with the formation of membrane lipid-damaging, reactive oxygen species. Until recently a mechanism to transport heme and protoporphyrins into organelles of mammalian cells had not been identified. In this review, we focus on the roles of the recently identified heme/porphyrin transport proteins heme carrier protein 1 (HCP1), FLVCR, Abcg2 and Abcb6 and discuss how these transporters contribute to intracellular heme and porphyrin homeostasis.
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Affiliation(s)
- Partha Krishnamurthy
- Department of Pharmaceutical Sciences, MS 313, St. Jude Children's Research Hospital, 332. N. Lauderdale Avenue, Memphis, TN 38105, USA
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Govinda KR, Vijayakumaran P, Krishnamurthy P, Bevanur MS. Effective participation of TB sanatoria in Revised National TB Control Programme (DOTS) in a metropolitan city. Indian J Tuberc 2007; 54:30-5. [PMID: 17455421] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
BACKGROUND Revised National TB Control Programme has been implemented since 1998 in Bangalore metropolitan city which has several big general hospitals, including two TB sanatoria which attract a large number of respiratory symptomatic and TB patients. Till recently there was significant loss of patients for follow up because of lack of mechanism to reach the patients, good recording practices and linkage with district TB control office. OBJECTIVE To establish an effective referral mechanism between TB sanatoria and peripheral health institutions of the government for providing un-interrupted supervised treatment (DOT) to all newly detected TB patients. METHOD TB sanatoria remain as "islands" when Reyised National TB Control Programme (RNTCP) with DOTS strategy is implemented. Damien Foundation India Trust (DFIT) provided a Technical Support Team (one medical consultant and three supervisors) to assist in implementation of RNTCP in the district. DFIT liaised with both partners and established procedures for recording correct address, informing health institutions and Senior TB Supervisors (STS) and monitoring referrals. Referral slip and a copy of treatment card were given to patients. One copy of treatment card was sent to respective health facility. Initially the number of STS was not adequate to follow up the patients. The supervisors of Technical Support Team ensured that they were treated in peripheral health institutions or near patients' residence. All STS were in position one year after initiation of this effort. RESULTS The referral system is functional. Case holding improved from about 50% to 85% during 2002-2005 by effective transfer through referrals. CONCLUSION Interfacing of NGO between district TB control office and TB sanatoria enabled the establishment of effective collaboration. Initial reluctance was replaced by complete participation in the TB control programme.
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Affiliation(s)
- K R Govinda
- Technical Support Team - RNTCP, Bangalore Urban district
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Krishnamurthy P. Diagnosis of leprosy. J Indian Med Assoc 2006; 104:680-1, 685. [PMID: 17474284] [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] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Of all the diagnoses of dermatological disorders, the leprosy is perhaps the easiest one to be done on one side but difficult also on the other side. Proper history taking in the diagnosis is very important. Clinical examination is intended to find out if the patient has any skin or nerve lesion. The most important is the definite sensory deficit in the skin lesions which if present confirms the diagnosis of leprosy. Nerve examination necessitates to see the involvement of peripheral nerves eg, ulnar, lateral popliteal, posterior tibial, median or facial. In the routine diagnosis of cases, slit-skin smear from skin lesions and ear lobes is generally not required. The presence of any cardinal sign, related to skin patch or nerve, confirms the diagnosis.
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Shivakumar M, Prabhakarareddy B, Rajaprasannakumar A, Vijayakumaran P, Krishnamurthy P. Repeated sputum microscopy is not essential for monitoring tuberculosis treatment response. Int J Tuberc Lung Dis 2006; 10:1296-8. [PMID: 17131792] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023] Open
Abstract
SETTING This study was conducted in two districts in India where DOTS has been implemented. There are 39 microscopy centres in Anantpur district and 34 in Nellore district (one per 100,000 population), each with a trained microscopist. Periodic follow-up sputum microscopy is performed for all tuberculosis (TB) patients on treatment, with two sputum specimens examined on each follow-up. Results are recorded in a laboratory register. OBJECTIVE To determine whether examining two sputum specimens for follow-up is useful for assessing treatment outcome. DESIGN A retrospective study using data from laboratory registers of all microscopy centres for 2002 in Anantpur and 2003 (January-June) in Nellore. RESULTS Of 5086 follow-up examinations done in Anantpur and 1028 in Nellore, 8% were acid-fast bacilli positive. One additional positive result was obtained on examination of a second sputum specimen. This result did not significantly add to the assessment of treatment outcome. CONCLUSION The yield of a second on-the-spot sputum specimen is negligible, provided that the first smear is from an overnight specimen. From the data available, it is evident that repeated follow-up smears are not essential for documenting treatment outcome.
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Affiliation(s)
- M Shivakumar
- Technical Support Team, Anantpur, Andra Pradesh, India
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Abstract
ABC (ATP-binding cassette) transporters have diverse roles in many cellular processes. These diverse roles require the presence of conserved membrane spanning domains and nucleotide binding domains. Bcrp (Abcg2) is a member of the ATP binding cassette family of plasma membrane transporters that was originally discovered for its ability to confer drug resistance in tumor cells. Subsequent studies showed Bcrp expression in normal tissues and high expression in primitive stem cells. Bcrp expression is induced under low oxygen conditions consistent with its high expression in tissues exposed to low oxygen environments. Moreover, Bcrp interacts with heme and other porphyrins. This finding and its regulation by hypoxia suggests it may play a role in protecting cells/tissue from protoporphyrin accumulation under hypoxia. These observations are strengthened by the fact that porphyrins accumulate in tissues of the Bcrp knockout mouse. It is possible that humans with loss of function Bcrp alleles may be more susceptible to porphyrin-induced phototoxicity. We propose that Bcrp plays a role in porphyrin homoeostasis and regulates survival under low oxygen conditions.
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Affiliation(s)
- Partha Krishnamurthy
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, 332 N. Lauderdale Ave., Memphis, TN 38105-2794 , USA
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