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Gut Mar 2021Shortage of organ donors, a critical challenge for treatment of end-stage organ failure, has motivated the development of alternative strategies to generate organs in...
OBJECTIVE
Shortage of organ donors, a critical challenge for treatment of end-stage organ failure, has motivated the development of alternative strategies to generate organs in vitro. Here, we aim to describe the hepatorganoids, which is a liver tissue model generated by three-dimensional (3D) bioprinting of HepaRG cells and investigate its liver functions in vitro and in vivo.
DESIGN
3D bioprinted hepatorganoids (3DP-HOs) were constructed using HepaRG cells and bioink, according to specific 3D printing procedures. Liver functions of 3DP-HOs were detected after 7 days of differentiation in vitro, which were later transplanted into Fah-deficient mice. The in vivo liver functions of 3DP-HOs were evaluated by survival time and liver damage of mice, human liver function markers and human-specific debrisoquine metabolite production.
RESULTS
3DP-HOs broadly acquired liver functions, such as ALBUMIN secretion, drug metabolism and glycogen storage after 7 days of differentiation. After transplantation into abdominal cavity of mouse model of liver injury, 3DP-HOs further matured and displayed increased synthesis of liver-specific proteins. Particularly, the mice acquired human-specific drug metabolism activities. Functional vascular systems were also formed in transplanted 3DP-HOs, further enhancing the material transport and liver functions of 3DP-HOs. Most importantly, transplantation of 3DP-HOs significantly improved the survival of mice.
CONCLUSIONS
Our results demonstrated a comprehensive proof of principle, which indicated that 3DP-HO model of liver tissues possessed in vivo hepatic functions and alleviated liver failure after transplantation, suggesting that 3D bioprinting could be used to generate human liver tissues as the alternative transplantation donors for treatment of liver diseases.
Topics: Animals; Bioprinting; Cell Differentiation; Cell Proliferation; Cell Survival; Disease Models, Animal; Graft Survival; Liver; Liver Failure; Liver Function Tests; Liver Transplantation; Mice; Printing, Three-Dimensional; Survival Rate
PubMed: 32434830
DOI: 10.1136/gutjnl-2019-319960 -
Pharmacogenomics Nov 2021Genetic variation in the gene encoding CYP2D6 is used to guide drug prescribing in clinical practice. However, genetic variants in CYP2D6 show substrate-specific effects...
Genetic variation in the gene encoding CYP2D6 is used to guide drug prescribing in clinical practice. However, genetic variants in CYP2D6 show substrate-specific effects that are currently not accounted for. With a systematic literature, we retrieved 22 original studies describing experiments focusing on alleles (*1, *2, *10 and *17) and substrates. Allele activity (clearance of the allele of interest divided by the clearance of the wildtype) was extracted. The results support the hypothesis of the existence of substrate specificity of the *17-allele (higher debrisoquine clearance), a subtle effect of the *10-allele (lower dextromethorphan clearance) but no substrate-specific effect of the *2-allele. Although our results support substrate specificity, for most substrates data are too sparse and require further studies.
Topics: Alleles; Cytochrome P-450 CYP2D6; Debrisoquin; Genetic Variation; Humans; Isoenzymes; Substrate Specificity
PubMed: 34569808
DOI: 10.2217/pgs-2021-0093 -
International Journal of Cancer May 2011Parkinson's disease (PD) is a neurodegenerative disorder characterized by a loss of melanin-positive, dopaminergic neurons in the substantia nigra. Although there is... (Review)
Review
Parkinson's disease (PD) is a neurodegenerative disorder characterized by a loss of melanin-positive, dopaminergic neurons in the substantia nigra. Although there is convincing epidemiologic evidence of a negative association between PD and most cancers, a notable exception to this is that melanoma, a malignant tumor of melanin-producing cells in skin, occurs with higher-than-expected frequency among subjects with PD and that melanoma patients are more likely to have PD. A clear biological explanation for this epidemiological observation is lacking. Here, we present a comprehensive review of published literature exploring the association between PD and melanoma. On the basis of published findings, we conclude that (i) changes in pigmentation including melanin synthesis and/or melanin synthesis enzymes, such as tyrosinase and tyrosine hydroxylase, play important roles in altered vulnerability for both PD and melanoma; (ii) changes of PD-related genes such as Parkin, LRRK2 and α-synuclein may increase the risk of melanoma; (iii) changes in some low-penetrance genes such as cytochrome p450 debrisoquine hydroxylase locus, glutathione S-transferase M1 and vitamin D receptor could increase the risk for both PD and melanoma and (iv) impaired autophagy in both PD and melanoma could also explain the association between PD and melanoma. Future studies are required to address whether altered pigmentation, PD- or melanoma-related gene changes and/or changes in autophagy function induce oncogenesis or apoptosis. From a clinical point of view, early diagnosis of melanoma in PD patients is critical and can be enhanced by periodic dermatological surveillance, including skin biopsies.
Topics: Humans; Incidence; Melanoma; Parkinson Disease; Risk Factors
PubMed: 21207412
DOI: 10.1002/ijc.25912 -
Canadian Medical Association Journal Jan 1977Clonidine, propranolol, bethanidine and debrisoquine effectively decrease blood pressure by suppressing renin secretion or interfering with function of the sympathetic... (Review)
Review
Clonidine, propranolol, bethanidine and debrisoquine effectively decrease blood pressure by suppressing renin secretion or interfering with function of the sympathetic nervous system. In man these compounds exert an antihypertensive effect within several hours or days and their duration of action is sufficient to permit administration twice or thrice daily. Clonidine and propranolol are especially useful if sexual dysfunction or postural hypotension is undesirable. Although bethanidine and debrisoquine may produce these adverse effects, they are beneficial in severe hypertension and produce fewer side effects than guanethidine. Clonidine frequently causes sedation, and rebound hypertension may occur with sudden cessation of therapy. Injudicious use of propranolol may provoke heart failure or asthma in susceptible individuals. The combination of a thiazide diuretic with propranolol and one of hydralazine, bethanidine and debrisoquine may be used to treat severe or complicated hypertension.
Topics: Antihypertensive Agents; Bethanidine; Clonidine; Debrisoquin; Female; Humans; Hypertension; Male; Propranolol
PubMed: 343894
DOI: No ID Found -
The Israel Medical Association Journal... Dec 2004Melanoma is the leading cause of death from skin tumors worldwide, with an annual increase in incidence over the past decade. The molecular mechanisms involved in... (Review)
Review
Melanoma is the leading cause of death from skin tumors worldwide, with an annual increase in incidence over the past decade. The molecular mechanisms involved in melanoma pathogenesis are beginning to be unraveled. While a family history of melanoma and exposure to ultraviolet irradiation have been known for years as risk factors in melanoma development, the precise genes involved in inherited predisposition were defined only in the past decade. Germline mutations in two genes that play a pivotal role in controlling cell cycle and division--CDKN2A and cyclin-dependent kinase 4 (CDK4)--have been detected in autosomal, dominant, high penetrance familial melanoma cases. In addition to these two highly penetrant genes, germline mutations and polymorphisms in a few low penetrance genes have been reported in familial melanoma cases: melanocortin-1 receptor, epidermal growth factor, glutathione s-transferase M1, cytochrome p450 debrisoquine hydroxylase locus (CYP2D6) and vitamin D receptor.
Topics: Cytochrome P-450 CYP2D6; Epidermal Growth Factor; Genes, p16; Genetic Predisposition to Disease; Glutathione Transferase; Humans; Melanoma; Penetrance; Receptor, Melanocortin, Type 1; Receptors, Calcitriol
PubMed: 15609895
DOI: No ID Found -
Environmental Health Perspectives Jun 1997Cytochrome P450 (CYP) enzymes catalyze the generation of reactive species capable of binding with cellular macromolecules, leading to acute and delayed toxicity. Since... (Review)
Review
Cytochrome P450 (CYP) enzymes catalyze the generation of reactive species capable of binding with cellular macromolecules, leading to acute and delayed toxicity. Since individual CYP forms differ markedly in their substrate preferences and regulation, the expression profiles of CYP in various cell types are important determinants in tissue-specific toxicity. The highest concentrations of most forms of CYP are found in liver, but they are also present in many extrahepatic organs. Liver is also a target organ in which CYP-mediated activation and toxic outcome have been most convincingly linked. Prime examples are paracetamol-induced hepatotoxicity and aflatoxin B1-associated hepatic cancer. In contrast to liver, most extrahepatic tissues are composed of multiple call types, which make experimental approaches difficult. Also the low abundance of individual forms is a challenge in the study of extrahepatic CYP-related toxicity. Recent years have witnessed the emergence of molecular biological techniques, e.g., reverse transcriptase-polymerase chain reactions, which facilitate the study of low abundant CYP forms in human tissues. Nevertheless, in the end we need definite information on the expression of activity, and for this purpose enzyme-specific substrates, reactions, and inhibitors and other methods to detect proteins and associated activities are needed. In humans, it is important to measure activities of specific enzymes in vivo. For this purpose, two approaches are currently available. Metabolism and/or elimination of enzyme-specific drugs can be employed. In cases in which genetic background determines the presence or absence of a specific enzyme, phenotyping and genotyping tests can be devised, e.g., for CYP2D6 (debrisoquine hydroxylation) polymorphism.
Topics: Biotransformation; Brain; Cloning, Molecular; Cytochrome P-450 Enzyme System; Hazardous Substances; Humans; Leukocytes; Liver; Lung; Organ Specificity; Polymerase Chain Reaction
PubMed: 9255560
DOI: 10.1289/ehp.97105s4767 -
Drug Metabolism and Pharmacokinetics Apr 2004Metabolic capacities for debrisoquin, sparteine, mephenytoin, nifedipine, and midazolam, which are substrates of polymorphic CYP2D6, CYP2C19, and CYP3A, have been... (Review)
Review
Metabolic capacities for debrisoquin, sparteine, mephenytoin, nifedipine, and midazolam, which are substrates of polymorphic CYP2D6, CYP2C19, and CYP3A, have been reported to exhibit, in many cases, remarkable interindividual and ethnic differences. These ethnic differences are partly associated with genetic differences. In the case of the drug transporter ABCB1/MDR1, interindividual differences in its transporter activities toward various clinical drugs are also attributed to several ABCB1/MDR1 genetic polymorphisms. In this review, the existence and frequency of various low-activity alleles of drug metabolizing enzymes as well as populational drug metabolic capacities are compared among several different races or ethnicities. Distribution of nonsynonymous ABCB1/MDR1 SNPs and haplotype frequency in various races are summarized, with the association of nonsynonymous SNPs with large functional alterations as a rare event.
Topics: ATP Binding Cassette Transporter 1; ATP-Binding Cassette Transporters; Aryl Hydrocarbon Hydroxylases; Cytochrome P-450 CYP2C19; Cytochrome P-450 CYP2D6; Cytochrome P-450 CYP3A; Ethnicity; Genes, MDR; Humans; Mixed Function Oxygenases; Oxidation-Reduction; Oxidoreductases, N-Demethylating; Polymorphism, Genetic
PubMed: 15499174
DOI: 10.2133/dmpk.19.83 -
Scandinavian Journal of Work,... 1992Many chemical carcinogens need activation by drug metabolizing enzymes, principally cytochrome P450 enzymes, to become capable of binding to deoxyribonucleic acid and... (Review)
Review
Many chemical carcinogens need activation by drug metabolizing enzymes, principally cytochrome P450 enzymes, to become capable of binding to deoxyribonucleic acid and initiating the carcinogenic process. The activity and inducibility of drug metabolizing enzymes are regulated by interplay between genetic, host, and environmental factors. Consequently, individual differences in cancer susceptibility might be explained somewhat by genetic differences in metabolic activation. Three examples, the induction of aryl hydrocarbon (benzo[a]pyrene) hydroxylase by polycyclic aromatic hydrocarbons, polymorphic debrisoquine/sparteine oxidation, and polymorphic acetylation, are briefly reviewed. Despite useful animal models and promising early human findings, no consensus has been reached about the significance of genetically based differences in drug metabolism in cancer etiology. It is expected that, with the use of molecular biological methods, the genetic background of study subjects can be investigated without bias caused by the disease, age, treatment, or other factors which have plagued investigations thus far.
Topics: Acetylation; Animals; Antipyrine; Aryl Hydrocarbon Hydroxylases; Carcinogens; Debrisoquin; Forecasting; Humans; Lung Neoplasms; Metabolism; Polymorphism, Genetic; Sparteine; Urinary Bladder Neoplasms
PubMed: 1411373
DOI: No ID Found -
Environmental Health Perspectives Apr 1988This paper assesses the capacity of animal models to predict human response to carcinogenic agents with consideration for the heterogeneity of humans. It is widely... (Review)
Review
This paper assesses the capacity of animal models to predict human response to carcinogenic agents with consideration for the heterogeneity of humans. It is widely accepted that human susceptibility to toxic substances, including carcinogens, is highly variable. Conventional rodent models are usually highly inbred and valued for their ability to display characteristic homogeneity. Current practice assumes that the homogeneity of response to toxic agents, including carcinogens, in the rodent model will be representative of humans. The issue then becomes, To which of the broad spectrum of human responses are specific animal models likely to be related? This paper examines the extent of human heterogeneity over a broad range of biochemical characteristics (e.g., aryl hydrocarbon hydroxylase activity, epoxide hydrase activity, beta-glucuronidase activity, debrisoquine hydroxylation, DNA-adduct formation) with emphasis on those biochemical characteristics that affect responses to carcinogens. Examples are presented to compare the heterogeneity of selected animal models for these biochemical characteristics as they relate to the spectrum of human responses noted above. The paper presents a theoretical perspective for determining to which part of the human population response spectrum common animal models are most likely to be extrapolated.
Topics: Animals; Carcinogens; Disease Models, Animal; Humans; Species Specificity
PubMed: 3289908
DOI: 10.1289/ehp.887755 -
British Journal of Pharmacology Mar 2021The metabolic activity of cytochrome P450 (CYP) 2D6 is highly variable and CYP2D6 genotypes insufficiently explain the extensive and intermediate metabolic phenotypes,...
BACKGROUND AND PURPOSE
The metabolic activity of cytochrome P450 (CYP) 2D6 is highly variable and CYP2D6 genotypes insufficiently explain the extensive and intermediate metabolic phenotypes, limiting the prediction of drug response plus adverse drug reactions. Since CYP2D6 prototypic substrates are positively charged, the aim of this study was to evaluate the organic cation transporters (OCTs) and multidrug and toxin extrusion proteins (MATEs) as potential contributors to the variability of CYP2D6 hydroxylation of debrisoquine, dextromethorphan, diphenhydramine, perhexiline and sparteine.
EXPERIMENTAL APPROACH
OCT1/SLC22A1-, OCT2/SLC22A2-, OCT3/SLC22A3-, MATE1/SLC47A1-, and MATE2K/SLC47A2-overexpressing cell lines were used to investigate the transport of the selected drugs. Individuals from a study cohort, well defined with respect to CYP2D6 genotype and sparteine pharmacokinetics, were genotyped for the common OCT1 variants rs12208357 (OCT1-R61C), rs34130495 (OCT1-G401S), rs202220802 (OCT1-Met420del), rs34059508 (OCT1-G465R), OCT2 variant rs316019 (OCT2-A270S) and MATE1 variant rs2289669. Sparteine pharmacokinetics was stratified according to CYP2D6 and OCT1, OCT2 or MATE1 genotype.
KEY RESULTS
OCTs and MATE1 transport sparteine and debrisoquine with high affinity in vitro, but OCT- and MATE1-dependent transport of dextromethorphan, diphenhydramine and perhexiline was not detected. Sparteine and debrisoquine transport depends on OCT1 genotype; however, sparteine pharmacokinetics is independent from OCT1 genotype.
CONCLUSIONS AND IMPLICATIONS
Some drugs that are substrates of CYP2D6 are also substrates of OCTs and MATE1, suggesting overlapping specificities. Variability in sparteine hydroxylation in extensive and intermediate metabolizers cannot be explained by OCT1 genetic variants indicating presence of other factors. Dose-dependent toxicities of dextromethorphan, diphenhydramine and perhexiline appear to be independent from OCTs and MATEs.
Topics: Cations; Cytochrome P-450 CYP2D6; Humans; Organic Cation Transport Proteins; Organic Cation Transporter 2; Pharmaceutical Preparations; Phenotype
PubMed: 33434947
DOI: 10.1111/bph.15370