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1.
J Obstet Gynaecol Res ; 49(12): 2938-2945, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37667814

ABSTRACT

AIM: To explore the electrophysiological characteristics of the independent muscles in the pelvic floor muscle (PFM) group of postpartum women with diastasis recti abdominis (DRA) and analyze the correlation between the rectus abdominis interval and PFM function. METHODS: A total of 133 women who underwent postpartum re-examination from August 2021 to July 2022 were collected. The participants were divided into DRA and control groups based on the occurrence of DRA on ultrasonography. General data of the participants were collected, and the multisite surface electromyography (sEMG) assessment of the PFMs was performed using a intravaginal novel airbag-type stretchable electrode array device developed by the team. The sEMG characteristics of the different PFMs in the two groups were compared, and the correlation between the maximum rectus abdominis interval and the sEMG parameters of different PFMs was analyzed. RESULTS: There were no differences in the baseline demographics and incidence of pelvic floor dysfunction between the two groups (p > 0.05). The mean amplitude of vaginal sphincter endurance contraction in the DRA group was significantly lower than that in the control group (28.44 ± 15.59 vs. 22.03 [12.22, 28.00], p < 0.05). Spearman's rank correlation analysis showed a weak negative correlation between the maximum rectus abdominis interval and the endurance contraction mean amplitude of the urethral and external anal sphincters (r = -0.173, -0.217, p < 0.05). CONCLUSIONS: Patients with DRA had weakened PFM endurance, and there was a weak negative correlation between the maximum rectus abdominis interval and the endurance contraction mean amplitude of the PFM.


Subject(s)
Diastasis, Muscle , Rectus Abdominis , Humans , Female , Rectus Abdominis/diagnostic imaging , Pelvic Floor/diagnostic imaging , Electromyography , Postpartum Period
2.
Int J Biol Sci ; 19(2): 393-411, 2023.
Article in English | MEDLINE | ID: mdl-36632462

ABSTRACT

Asthenoteratozoospermia is one of the major factors for male infertility, whereas the causes of large numbers of cases are still unknown. We identified compound heterozygous variants of FSIP2 in three unrelated individuals from a cohort of 105 patients with asthenoteratozoospermia by exome sequencing. Deleterious FSIP2 variations caused severe disassembly of the fibrous sheath and axonemal defects. Intriguingly, spermatozoa in our study manifested "super-length" mitochondrial sheaths, increased levels of the mitochondrial sheath outer membrane protein TOMM20 and decreased mitochondrial ATP consumption. Dislocation or deletion of the annulus and reduction or dislocation of the annulus protein SEPT4 were also observed. While the lengthened mitochondrial sheaths were not presented in men harboring SEPT4 variants. Furthermore, female partners of two of three men achieved successful pregnancies following intracytoplasmic sperm injection (ICSI). Overall, we presume that FSIP2 may not only serve as a structural protein of the fibrous sheath but also as an intra-flagellar transporter involving in the axonemal assembly, mitochondrial selection and the termination of mitochondrial sheath extension during spermatogenesis, and ICSI is an effective treatment for individuals with FSIP2-associated asthenoteratozoospermia.


Subject(s)
Asthenozoospermia , Axonemal Dyneins , Mitochondria , Seminal Plasma Proteins , Female , Humans , Male , Pregnancy , Asthenozoospermia/genetics , Spermatogenesis/genetics , Spermatozoa/ultrastructure , Seminal Plasma Proteins/genetics , Axonemal Dyneins/genetics , Sperm Injections, Intracytoplasmic , Mitochondria/ultrastructure
3.
Sci Total Environ ; 867: 161472, 2023 Apr 01.
Article in English | MEDLINE | ID: mdl-36638985

ABSTRACT

Previous studies have reported potential adverse effects of exposure to ambient air pollutants on semen quality in infertile men, but studies on the general population have been limited and inconsistent, and the pollutants that play a major role remain unclear. This study aimed to explore the potential association between exposure to six air pollutants (PM2.5, PM10, NO2, SO2, O3 and CO) during different sperm development periods and semen quality among the general population, and to explore the interaction between different air pollutant exposures. We included 1515 semen samples collected from the Human Sperm Bank. We improved individuals' exposure level estimation by combining inverse distance weighting (IDW) interpolation with satellite remote sensing data. Multivariate linear regression models, restricted cubic spline functions and double-pollutant models were used to assess the relationship between exposure to six air pollutants and sperm volume, concentration, total sperm number and sperm motility. A negative association was found between SO2 exposure and progressive motility and total motility during 0-90 lag days and 70-90 lag days, and SO2 exposure during 10-14 lag days adversely affected sperm concentration and total sperm number. Sensitive analyses for qualified sperm donors and the double-pollutant models obtained similar results. Additionally, there were nonlinear relationships between exposure to PM, NO2, O3, CO and a few semen parameters, with NO2 and O3 exposure above the threshold showing negative correlations with total motility and progressive motility, respectively. Our study suggested that SO2 may play a dominant role in the adverse effects of ambient air pollutants on semen quality in the general population by decreasing sperm motility, sperm concentration and total sperm number. Also, even SO2 exposure lower than the recommended standards of the World Health Organization (WHO) could still cause male reproductive toxicity, which deserves attention.


Subject(s)
Air Pollutants , Air Pollution , Environmental Pollutants , Humans , Male , Air Pollutants/toxicity , Air Pollutants/analysis , Sulfur Dioxide/toxicity , Sulfur Dioxide/analysis , Semen Analysis , Environmental Pollutants/analysis , Nitrogen Dioxide/toxicity , Nitrogen Dioxide/analysis , Air Pollution/adverse effects , Air Pollution/analysis , Particulate Matter/analysis , Semen , Sperm Motility , China/epidemiology , Environmental Exposure/analysis
4.
Clin Genet ; 102(2): 130-135, 2022 08.
Article in English | MEDLINE | ID: mdl-35543642

ABSTRACT

Male infertility is an increasingly serious health problem affecting couples of reproductive age. Mutations in axoneme-associated genes cause male infertility. Dynein arm proteins are essential in sustaining normal axonemes and promote flagellar motility. However, the function of DNAH7 in male fertility in vivo remains unclear. Herein, we showed that DNAH7 disruption in humans results in male infertility, which was characterised by multiple morphological abnormalities of sperm flagella. The axoneme structure of the sperm from a DNAH7-deficient patient revealed the loss of inner dynein arms. Moreover, the mitochondria of the sperm flagella detached and dispersed outside the axoneme, leading to abnormalities in the mitochondrial sheath in the mid-piece region. Live birth was achieved via intracytoplasmic sperm injection. Thus, DNAH7 is critical for axoneme and mitochondrial development in human sperm. These findings further clarify the spectrum of DNAH7 biology and provide new insights for diagnosing infertility and treating patients harbouring DNAH7 mutations.


Subject(s)
Dyneins/genetics , Infertility, Male , Dyneins/metabolism , Humans , Infertility, Male/genetics , Loss of Function Mutation , Male , Mitochondria/genetics , Mitochondria/metabolism , Mutation , Semen/metabolism , Sperm Tail/metabolism , Spermatozoa/metabolism
5.
Adv Sci (Weinh) ; 9(20): e2200315, 2022 07.
Article in English | MEDLINE | ID: mdl-35521971

ABSTRACT

Stimulated Raman scattering (SRS) microscopy is an emerging technology that provides high chemical specificity for endogenous biomolecules and can circumvent common constraints of fluorescence microscopy including limited capabilities to probe small biomolecules and difficulty resolving many colors simultaneously. However, the resolution of SRS microscopy remains governed by the diffraction limit. To overcome this, a new technique called molecule anchorable gel-enabled nanoscale Imaging of Fluorescence and stimulated Raman scattering microscopy (MAGNIFIERS) that integrates SRS microscopy with expansion microscopy (ExM) is described. MAGNIFIERS offers chemical-specific nanoscale imaging with sub-50 nm resolution and has scalable multiplexity when combined with multiplex Raman probes and fluorescent labels. MAGNIFIERS is used to visualize nanoscale features in a label-free manner with CH vibration of proteins, lipids, and DNA in a broad range of biological specimens, from mouse brain, liver, and kidney to human lung organoid. In addition, MAGNIFIERS is applied to track nanoscale features of protein synthesis in protein aggregates using metabolic labeling of small metabolites. Finally, MAGNIFIERS is used to demonstrate 8-color nanoscale imaging in an expanded mouse brain section. Overall, MAGNIFIERS is a valuable platform for super-resolution label-free chemical imaging, high-resolution metabolic imaging, and highly multiplexed nanoscale imaging, thus bringing SRS to nanoscopy.


Subject(s)
Nonlinear Optical Microscopy , Vibration , Animals , Humans , Mice , Microscopy/methods , Nonlinear Optical Microscopy/methods , Proteins , Spectrum Analysis, Raman/methods
6.
Reprod Biol Endocrinol ; 20(1): 5, 2022 Jan 03.
Article in English | MEDLINE | ID: mdl-34980136

ABSTRACT

BACKGROUND: Potassium channels are important for the structure and function of the spermatozoa. As a potassium transporter, the mSlo3 is essential for male fertility as Slo3 knockout male mice were infertile with the series of functional defects in sperm cells. However, no pathogenic variant has been detected in human SLO3 to date. Here we reported a human case with homozygous SLO3 mutation. The function of SLO3 in human sperm and the corresponding assisted reproductive strategy are also investigated. METHODS: We performed whole-exome sequencing analysis from a large cohort of 105 patients with asthenoteratozoospermia. The effects of the variant were investigated by quantitative RT-PCR, western blotting, and immunofluorescence assays using the patient spermatozoa. Sperm morphological and ultrastructural studies were conducted using haematoxylin and eosin staining, scanning and transmission electron microscopy. RESULTS: We identified a homozygous missense variant (c.1237A > T: p.Ile413Phe) in the sperm-specific SLO3 in one Chinese patient with male infertility. This SLO3 variant was rare in human control populations and predicted to be deleterious by multiple bioinformatic tools. Sperm from the individual harbouring the homozygous SLO3 variant exhibited severe morphological abnormalities, such as acrosome hypoplasia, disruption of the mitochondrial sheath, coiled tails, and motility defects. The levels of SLO3 mRNA and protein in spermatozoa from the affected individual were reduced. Furthermore, the acrosome reaction, mitochondrial membrane potential, and membrane potential during capacitation were also afflicted. The levels of acrosome marker glycoproteins and PLCζ1 as well as the mitochondrial sheath protein HSP60 and SLO3 auxiliary subunit LRRC52, were significantly reduced in the spermatozoa from the affected individual. The affected man was sterile due to acrosome and mitochondrial dysfunction; however, intra-cytoplasmic sperm injection successfully rescued this infertile condition. CONCLUSIONS: SLO3 deficiency seriously impact acrosome formation, mitochondrial sheath assembly, and the function of K+ channels. Our findings provided clinical implications for the genetic and reproductive counselling of affected families.


Subject(s)
Acrosome/pathology , Asthenozoospermia/genetics , Infertility, Male/genetics , Acrosome Reaction/genetics , Adult , Asthenozoospermia/pathology , China , Cohort Studies , Consanguinity , Family Characteristics , Female , Homozygote , Humans , Infertility, Male/pathology , Infertility, Male/therapy , Large-Conductance Calcium-Activated Potassium Channels , Male , Membrane Potential, Mitochondrial/genetics , Mitochondria/metabolism , Mitochondria/pathology , Mitochondrial Membranes/pathology , Mutation, Missense , Pedigree , Pregnancy , Sperm Injections, Intracytoplasmic , Spermatozoa/abnormalities , Spermatozoa/pathology
7.
Am J Hum Genet ; 107(3): 514-526, 2020 09 03.
Article in English | MEDLINE | ID: mdl-32791035

ABSTRACT

Multiple morphological abnormalities of the sperm flagella (MMAF) is a severe form of asthenoteratozoospermia. Although recent studies have revealed several MMAF-associated genes and demonstrated MMAF to be a genetically heterogeneous disease, at least one-third of the cases are still not well understood for their etiology. Here, we identified bi-allelic loss-of-function variants in CFAP58 by using whole-exome sequencing in five (5.6%) unrelated individuals from a cohort of 90 MMAF-affected Chinese men. Each of the men harboring bi-allelic CFAP58 variants presented typical MMAF phenotypes. Transmission electron microscopy demonstrated striking flagellar defects with axonemal and mitochondrial sheath malformations. CFAP58 is predominantly expressed in the testis and encodes a cilia- and flagella-associated protein. Immunofluorescence assays showed that CFAP58 localized at the entire flagella of control sperm and predominantly concentrated in the mid-piece. Immunoblotting and immunofluorescence assays showed that the abundances of axoneme ultrastructure markers SPAG6 and SPEF2 and a mitochondrial sheath protein, HSP60, were significantly reduced in the spermatozoa from men harboring bi-allelic CFAP58 variants. We generated Cfap58-knockout mice via CRISPR/Cas9 technology. The male mice were infertile and presented with severe flagellar defects, consistent with the sperm phenotypes in MMAF-affected men. Overall, our findings in humans and mice strongly suggest that CFAP58 plays a vital role in sperm flagellogenesis and demonstrate that bi-allelic loss-of-function variants in CFAP58 can cause axoneme and peri-axoneme malformations leading to male infertility. This study provides crucial insights for understanding and counseling of MMAF-associated asthenoteratozoospermia.


Subject(s)
Abnormalities, Multiple/genetics , Asthenozoospermia/genetics , Axoneme/genetics , Infertility, Male/genetics , Intercellular Signaling Peptides and Proteins/genetics , Abnormalities, Multiple/pathology , Alleles , Animals , Asthenozoospermia/physiopathology , Axoneme/pathology , CRISPR-Cas Systems/genetics , Cell Cycle Proteins/genetics , Homozygote , Humans , Infertility, Male/pathology , Loss of Function Mutation/genetics , Loss of Heterozygosity/genetics , Male , Mice , Mice, Knockout , Microtubule Proteins/genetics , Mitochondria/genetics , Sperm Tail/metabolism , Sperm Tail/pathology , Testis/metabolism , Testis/pathology , Exome Sequencing
8.
Nat Protoc ; 15(5): 1649-1672, 2020 05.
Article in English | MEDLINE | ID: mdl-32238952

ABSTRACT

In pathology, microscopy is an important tool for the analysis of human tissues, both for the scientific study of disease states and for diagnosis. However, the microscopes commonly used in pathology are limited in resolution by diffraction. Recently, we discovered that it was possible, through a chemical process, to isotropically expand preserved cells and tissues by 4-5× in linear dimension. We call this process expansion microscopy (ExM). ExM enables nanoscale resolution imaging on conventional microscopes. Here we describe protocols for the simple and effective physical expansion of a variety of human tissues and clinical specimens, including paraffin-embedded, fresh frozen and chemically stained human tissues. These protocols require only inexpensive, commercially available reagents and hardware commonly found in a routine pathology laboratory. Our protocols are written for researchers and pathologists experienced in conventional fluorescence microscopy. The conventional protocol, expansion pathology, can be completed in ~1 d with immunostained tissue sections and 2 d with unstained specimens. We also include a new, fast variant, rapid expansion pathology, that can be performed on <5-µm-thick tissue sections, taking <4 h with immunostained tissue sections and <8 h with unstained specimens.


Subject(s)
Acrylic Resins , Hydrogels/chemical synthesis , Microscopy, Fluorescence/methods , Nanotechnology/methods , Pathology/methods , Humans
9.
Cell Metab ; 29(4): 856-870.e7, 2019 04 02.
Article in English | MEDLINE | ID: mdl-30686744

ABSTRACT

The reactions catalyzed by the delta-5 and delta-6 desaturases (D5D/D6D), key enzymes responsible for highly unsaturated fatty acid (HUFA) synthesis, regenerate NAD+ from NADH. Here, we show that D5D/D6D provide a mechanism for glycolytic NAD+ recycling that permits ongoing glycolysis and cell viability when the cytosolic NAD+/NADH ratio is reduced, analogous to lactate fermentation. Although lesser in magnitude than lactate production, this desaturase-mediated NAD+ recycling is acutely adaptive when aerobic respiration is impaired in vivo. Notably, inhibition of either HUFA synthesis or lactate fermentation increases the other, underscoring their interdependence. Consistent with this, a type 2 diabetes risk haplotype in SLC16A11 that reduces pyruvate transport (thus limiting lactate production) increases D5D/D6D activity in vitro and in humans, demonstrating a chronic effect of desaturase-mediated NAD+ recycling. These findings highlight key biologic roles for D5D/D6D activity independent of their HUFA end products and expand the current paradigm of glycolytic NAD+ regeneration.


Subject(s)
Fatty Acids, Unsaturated/metabolism , Glycolysis , NAD/metabolism , Animals , Cells, Cultured , Delta-5 Fatty Acid Desaturase , Female , HEK293 Cells , Humans , Male , Mice , Mice, Inbred C57BL , Middle Aged
10.
Sensors (Basel) ; 18(10)2018 Oct 18.
Article in English | MEDLINE | ID: mdl-30340418

ABSTRACT

A method for gas⁻solid two-phase flow pattern identification in horizontal pneumatic conveying pipelines is proposed based on an electrostatic sensor array (ESA) and artificial neural network (ANN). The ESA contains eight identical arc shaped electrodes. Numerical simulation is conducted to discuss the contributions of the electrostatic signals to the flow patterns according to the error recognition rate, and the results show that the amplitudes of the output signals from each electrode of the ESA can give important information on the particle distribution and further infer the flow patterns. In experiments, the average values and standard deviations of the eight output signals' amplitudes are respectively extracted as the inputs of the ANN to identify four kinds of flow patterns in a pneumatic conveying pipeline, which are fully suspended flow, stratified flow, dune flow and slug flow. Results show that for any one of those two input values, the correct rates of the ANN model are all 100%.

11.
J Proteome Res ; 12(10): 4478-89, 2013 Oct 04.
Article in English | MEDLINE | ID: mdl-23961999

ABSTRACT

The complete genome of the solvent tolerant Staphylococcus warneri SG1 was recently published. This Gram-positive bacterium is tolerant to a large spectrum of organic solvents including short-chain alcohols, alkanes, esters and cyclic aromatic compounds. In this study, we applied a two-dimensional liquid chromatography (2D-LC) mass spectrometry (MS) shotgun approach, in combination with quantitative 2-MEGA (dimethylation after guanidination) isotopic labeling, to compare the proteomes of SG1 grown under butanol-free and butanol-challenged conditions. In total, 1585 unique proteins (representing 65% of the predicted open reading frames) were identified, covering all major metabolic pathways. Of the 967 quantifiable proteins by 2-MEGA labeling, 260 were differentially expressed by at least 1.5-fold. These proteins are involved in energy metabolism, oxidative stress response, lipid and cell envelope biogenesis, or have chaperone functions. We also applied differential isotope labeling LC-MS to probe metabolite changes in key metabolic pathways upon butanol stress. This is the first comprehensive proteomic and metabolomic study of S. warneri SG1 and presents an important step toward understanding its physiology and mechanism of solvent tolerance.


Subject(s)
Bacterial Proteins/metabolism , Butanols/metabolism , Proteome/metabolism , Staphylococcus/metabolism , Adaptation, Physiological , Amines/metabolism , Butanols/pharmacology , Carboxylic Acids/metabolism , Cell Membrane/drug effects , Cell Membrane/metabolism , Citric Acid Cycle , Energy Metabolism , Metabolome , Metabolomics , Microbial Viability , Phenols/metabolism , Proteomics , Staphylococcus/drug effects , Stress, Physiological
12.
IEEE Trans Biomed Eng ; 59(9): 2613-8, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22801485

ABSTRACT

The feasibility of characterization of human blood fibrinogen levels using optical coherence tomography (OCT) was investigated. Three groups of blood samples were reconstituted of red blood cells: 1) phosphate-buffered saline; 2) plasma with its intrinsic fibrinogen removed and commercial fibrinogen added; and 3) native plasma with various fibrinogen levels (0-12 g/L). OCT signal slope (OCTSS) of blood was extracted from OCT depth-reflectivity profiles. Effects of hematocrit (HCT) and blood flow on OCTSS of the blood under various fibrinogen concentrations were also studied. The results of blood flowing at 5 mm/s showed that OCTSS of all the three groups at HCT of 40% decreases with the increasing fibrinogen concentration up to a certain level, i. e., >8, 6, and 4 g/L for groups 1, 2, and 3, respectively. The blood of group 2 at HCTs of 30%, 40%, and 50% had a rapid decrease in OCTSS in the range of fibrinogen concentration of 0-2, 0-6, and 0-10 g/L, respectively. OCTSS value of blood flowing at 2.5 mm/s was lower than that at 5 mm/s at each fibrinogen concentration. In conclusion, OCTSS has a strong correlation with plasma fibrinogen concentration, and has the potential to identify the abnormal level of human blood fibrinogen.


Subject(s)
Blood Physiological Phenomena , Fibrinogen/analysis , Tomography, Optical Coherence/methods , Adult , Fibrinogen/metabolism , Hematocrit , Humans , Male , Models, Biological , Sodium Chloride
13.
J Biomed Opt ; 16(9): 096002, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21950916

ABSTRACT

This study investigates the optical properties of human blood during the coagulation process under statics using optical coherence tomography (OCT). OCT signal slope (OCTSS) and 1∕e light penetration depth (d(1∕e)) were obtained from the profiles of reflectance versus depth. Results showed that both OCTSS and d(1∕e) were able to sensitively differentiate various stages of blood properties during coagulating. After 1 h clotting, OCTSS decreased by 47.0%, 15.0%, 13.7%, and 8.5% and d(1∕e) increased by 34.7%, 29.4%, 24.3%, and 22.9% for the blood samples at HCT of 25%, 35%, 45%, and 55%, respectively. The slope of d(1∕e) versus time (S(r), ×10(-4) mm∕s), associated with clot formation rate decreased from 6.0 ± 0.3, 3.7 ± 0.5 to 2.3 ± 0.4 with the increasing of HCT from 35%, 45%, to 55%. The clotting time (t(c)) from the d(1∕e) evolution curves was estimated to be 1969 ± 92 s, 375 ± 12 s, 455 ± 11 s, and 865 ± 47 s for the blood of 25%, 35%, 45%, and 55%. This study demonstrates that the parameters (t(c) and S(r)) from the variations in d(1∕e) had better sensitivity and smaller standard deviation. Furthermore, blood hematocrit affecting backscattering properties of blood during coagulation was capable of being discerned by OCT parameters. It is concluded that OCT is a potential technique to quantify and follow the liquid-gel transition of blood during clotting.


Subject(s)
Blood Coagulation Tests/methods , Blood Coagulation/physiology , Tomography, Optical Coherence/methods , Adult , Hematocrit , Humans , Phase Transition , Sensitivity and Specificity
14.
Xenobiotica ; 41(7): 530-7, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21524190

ABSTRACT

This study compared the hepatic glucuronidation of Picroside II in different species and characterized the glucuronidation activities of human intestinal microsomes (HIMs) and recombinant human UDP-glucuronosyltransferases (UGTs) for Picroside II. The rank order of hepatic microsomal glucuronidation activity of Picroside II was rat > mouse > human > dog. The intrinsic clearance of Picroside II hepatic glucuronidation in rat, mouse and dog was about 10.6-, 6.0- and 2.3-fold of that in human, respectively. Among the 12 recombinant human UGTs, UGT1A7, UGT1A8, UGT1A9 and UGT1A10 catalyzed the glucuronidation. UGT1A10, which are expressed in extrahepatic tissues, showed the highest activity of Picroside II glucuronidation (K(m) = 45.1 µM, V(max) = 831.9 pmol/min/mg protein). UGT1A9 played a primary role in glucuronidation in human liver microsomes (HLM; K(m) = 81.3 µM, V(max) = 242.2 pmol/min/mg protein). In addition, both mycophenolic acid (substrate of UGT1A9) and emodin (substrate of UGT1A8 and UGT1A10) could inhibit the glucuronidation of Picroside II with the half maximal inhibitory concentration (IC(50)) values of 173.6 and 76.2 µM, respectively. Enzyme kinetics was also performed in HIMs. The K(m) value of Picroside II glucuronidation was close to that in recombinant human UGT1A10 (K(m) = 58.6 µM, V(max) = 721.4 pmol/min/mg protein). The intrinsic clearance was 5.4-fold of HLMs. Intestinal UGT enzymes play an important role in Picroside II glucuronidation in human.


Subject(s)
Biocatalysis , Cinnamates/metabolism , Glucuronides/metabolism , Glucuronosyltransferase/metabolism , Iridoid Glucosides/metabolism , Microsomes, Liver/metabolism , Recombinant Proteins/metabolism , Animals , Chromatography, High Pressure Liquid , Cinnamates/chemistry , Dogs , Glucuronides/chemistry , Humans , Intestinal Mucosa/metabolism , Iridoid Glucosides/chemistry , Isoenzymes/metabolism , Kinetics , Male , Mice , Rats , Species Specificity , Substrate Specificity
15.
Drug Metab Pharmacokinet ; 24(6): 523-8, 2009.
Article in English | MEDLINE | ID: mdl-20045987

ABSTRACT

Glycyrrhetinic acid, the active metabolite of glycyrrhizin, is primarily eliminated by glucuronidation reaction in vivo. In spite of the widespread clinical use of glycyrrhizin, UDP-glucuronosyltransferase (UGT) isoforms involved in the glucuronidation of this drug are still unknown. This report identifies and characterizes the UGT isoforms responsible for glycyrrhetinic acid glucuronidation. In the enzymatic kinetic experiment performed with pooled human liver microsomes (HLMs), K(m) was 39.4 microM and V(max) was 609.2 pmol/min/mg protein. Of the baculosomes expressing 12 recombinant UGTs investigated, UGT1A1, 1A3, 2B4 and 2B7 showed catalytic activity and UGT1A3 exhibited the highest activity. K(m) values of recombinant UGT1A3 and 2B7 were 3.4 and 4.4 microM, respectively. Both imipramine (typical substrate of UGT1A3 and 1A4) and flurbiprofen (typical substrate of UGT2B7) inhibit the glucuronidation of glycyrrhetinic acid. Estimated IC(50) values were 138 microM for flurbiprofen and 207 microM for imipramine in the inhibition of the glucuronidation of glycyrrhetinic acid in HLMs. These results suggest that glycyrrhetinic acid glucuronidation is primarily mediated by UGT1A1, 1A3, 2B4 and 2B7.


Subject(s)
Flurbiprofen/metabolism , Glucuronosyltransferase/metabolism , Glycyrrhetinic Acid/metabolism , Dose-Response Relationship, Drug , Glycyrrhizic Acid/metabolism , Humans , Kinetics , Metabolic Clearance Rate , Microsomes, Liver/drug effects , Microsomes, Liver/metabolism , Protein Isoforms/metabolism
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