ABSTRACT
A moment analysis method was developed for the study of solute permeation at the interface of spherical molecular aggregates. At first, new moment equations were developed for determining the partition equilibrium constant (Kp) and permeation rate constants (kin and kout) of solutes from the first absolute (µ1A) and second central (µ2C) moments of elution peaks measured by using high-performance liquid chromatography (HPLC). Then, the method was applied to the analysis of mass transfer phenomena of three solutes, i.e., hydroquinone, resorcinol, and catechol, at the interface of sodium dodecylsulfate (SDS) micelles. HPLC data were measured by using an ODS column and an aqueous phosphate buffer solution (pH = 7.0) as the mobile phase solvent. Pulse response experiments were conducted while changing SDS concentration (5 - 20 mmol dm-3) in the mobile phase under the conditions that the surface of ODS stationary phase was dynamically coated by SDS monomers. In order to demonstrate the effectiveness of the moment analysis method using HPLC, the values of Kp, kin, and kout were determined for the three solutes as 35 - 69, 2.4 × 10-8 - 1.4 × 10-6 m s-1, and 7.0 × 10-10 - 2.1 × 10-8 m s-1, respectively. Their values increase with an increase in the hydrophobicity of the solutes. The method has some advantages for the study of interfacial solute permeation of molecular aggregates. For example, neither immobilization nor chemical modification of both solute molecules and molecular aggregates is required when elution peaks are measured by using HPLC. Interfacial solute permeation takes place in the mobile phase without any chemical reaction or physical action on molecular aggregates. The values of Kp, kin, and kout were analytically determined from those of µ1A and µ2C by using the moment equations. The results of this study must contribute to the dissemination of an opportunity for studying the interfacial solute permeation of molecular aggregates to many researchers because of extremely high versatility of HPLC.
Subject(s)
Resorcinols , Sodium Dodecyl Sulfate , Chromatography, High Pressure Liquid/methods , Sodium Dodecyl Sulfate/chemistry , Resorcinols/chemistry , Micelles , Hydroquinones/chemistry , Catechols/chemistry , Kinetics , PermeabilityABSTRACT
Osteoporosis is caused by imbalance between osteogenesis and bone resorption, thus, osteogenic drugs and resorption inhibitors are used for treatment of osteoporosis. The present study examined the effects of (R)-4-(1-hydroxyethyl)-3-{4-[2-(tetrahydropyran-4-yloxy)ethoxy]phenoxy}benzamide (KY-273), a diphenyl ether derivative, on CDK8/19 activity, osteoblast differentiation and femoral bone using micro-computed tomography in female rats. KY-273 potently inhibited CDK8/19 activity, promoted osteoblast differentiation with an increase in alkaline phosphatase (ALP) activity, and gene expression of type I collagen, ALP and BMP-4 in mesenchymal stem cells (ST2 cells). In female rat femur, ovariectomy decreased metaphyseal trabecular bone volume (Tb.BV), mineral content (Tb.BMC), yet had no effect on metaphyseal and diaphyseal cortical bone volume (Ct.BV), mineral content (Ct.BMC) and strength parameters (BSPs). In ovaries-intact and ovariectomized rats, oral administration of KY-273 (10 mg/kg/d) for 6 weeks increased metaphyseal and diaphyseal Ct.BV, Ct.BMC, and BSPs without affecting medullary volume (Med.V), but did not affect Tb.BV and Tb.BMC. In ovariectomized rats, alendronate (3 mg/kg/d) caused marked restoration of Tb.BV, Tb.BMC and structural parameters after ovariectomy, and increased metaphyseal but not diaphyseal Ct.BV, Ct.BMC, and BSPs. In ovaries-intact and ovariectomized rats, by the last week, KY-273 increased bone formation rate/bone surface at the periosteal but not the endocortical side. These findings indicate that KY-273 causes osteogenesis in cortical bone at the periosteal side without reducing Med.V. In conclusion, KY-273 has cortical-bone-selective osteogenic effects by osteoblastogenesis via CDK8/19 inhibition in ovaries-intact and ovariectomized rats, and is an orally active drug candidate for bone diseases such as osteoporosis in monotherapy and combination therapy.
Subject(s)
Mesenchymal Stem Cells , Osteoporosis , Humans , Rats , Female , Animals , Osteogenesis , Bone Density , Rats, Sprague-Dawley , X-Ray Microtomography , Osteoporosis/drug therapy , Ovariectomy , Minerals/pharmacology , Cyclin-Dependent Kinase 8ABSTRACT
Hurler syndrome, a type of Mucopolysaccharidosis type I, is an inherited disorder caused by the accumulation of glycosaminoglycans (GAG) due to a deficiency in lysosomal α-L-iduronidase (IDUA), resulting in multiorgan dysfunction. In many patients with Hurler syndrome, IDUA proteins are not produced due to nonsense mutations in their genes; therefore, readthrough-inducing compounds, such as gentamycin, are expected to restore IDUA proteins by skipping the premature termination codon. In the present study, we synthesized a series of chromenopyridine derivatives to identify novel readthrough-inducing compounds. The readthrough-inducing activities of synthesized compounds were examined by measuring cellular IDUA activities and GAG concentrations in Hurler syndrome patient-derived cells. Compounds with a difluorophenyl group at the 2-position of chromenopyridine, a cyclobutyl group at the 3-position, and a basic side chain or basic fused ring exhibited excellent readthrough-inducing activities. KY-640, a chromenopyridine derivative with a tetrahydroisoquinoline sub-structure, increased the cellular IDUA activities of patient-derived cells by 3.2-fold at 0.3 µM and significantly reduced GAG concentrations, and also significantly increased enzyme activity in mouse models, suggesting its therapeutic potential in patients with Hurler syndrome.
Subject(s)
Mucopolysaccharidosis I , Mice , Animals , Humans , Mucopolysaccharidosis I/drug therapy , Mucopolysaccharidosis I/genetics , Codon, NonsenseABSTRACT
Osteoporosis is treated with oral and parenteral bone resorption inhibitors such as bisphosphonates, and parenteral osteogenic drugs including parathyroid hormone (PTH) analogues and anti-sclerostin antibodies. In the present study, we synthesized KY-054, a 4,6-substituted coumarin derivative, and found that it potently promoted osteoblast differentiation with an increase in alkaline phosphatase (ALP) activity at 0.01-1 µM in mouse-derived mesenchymal stem cells (ST2 cells) and rat bone marrow-derived mesenchymal stem cells (BMSCs). In the ovariectomized (OVX) rats, KY-054 (10 mg/kg/d, 8 weeks) increased plasma bone-type ALP activity, suggesting in vivo promoting effects on osteoblast differentiation and/or activation. In dual-energy X-ray absorption (DEXA) scanning, KY-054 significantly increased the distal and diaphyseal femurs areal bone mineral density (aBMD) that was decreased by ovariectomy, indicating its beneficial effects on bone mineral contents (BMC) and/or bone volume (BV). In micro-computed tomography (micro-CT) scanning, KY-054 had no effect on metaphysis trabecular bone loss and microarchitecture parameters weakened by ovariectomy, but instead increased metaphysis and diaphysis cortical bone volume (Ct.BV) and cortical BMC (Ct.BMC) without reducing medullary volume (Med.V), resulting in increased bone strength parameters. It is concluded that KY-054 preferentially promotes metaphysis and diaphysis cortical bone osteogenesis with little effect on metaphysis trabecular bone resorption, and is a potential orally active osteogenic anti-osteoporosis drug candidate.
Subject(s)
Osteogenesis , Osteoporosis , Rats , Female , Animals , Mice , Humans , X-Ray Microtomography , Bone and Bones , Bone Density , Femur , Osteoporosis/drug therapy , Cortical Bone , OvariectomyABSTRACT
The emergence of drug-resistant viruses is a serious concern in current chemotherapy for human immunodeficiency virus type-1 (HIV-1) infectious diseases. Hence, antiviral drugs aiming at targets that are different from those of approved drugs are still required, and the RNase H activity of HIV-1 reverse transcriptase is a suitable target. In this study, a search of a series of natural compounds was performed to identify the RNase H inhibitors. Three compounds were found to block the RNase H enzymatic activity. A laccaic acid skeleton was observed in all three natural compounds. A hydroxy phenyl group is connected to an anthraquinone backbone in the skeleton. An acetamido-ethyl, amino-carboxy-ethyl, and amino-ethyl are bound to the phenyl in laccaic acids A, C, and E, respectively. Laccaic acid C showed a 50% inhibitory concentration at 8.1 µM. Laccaic acid C also showed inhibitory activity in a cell-based viral proliferation assay. Binding structures of these three laccaic acids were determined by X-ray crystallographic analysis using a recombinant protein composed of the HIV-1 RNase H domain. Two divalent metal ions were located at the catalytic center in which one carbonyl and two hydroxy groups on the anthraquinone backbone chelated two metal ions. Molecular dynamics simulations were performed to examine the stabilities of the binding structures. Laccaic acid C showed the strongest binding to the catalytic site. These findings will be helpful for the design of potent inhibitors with modification of laccaic acids to enhance the binding affinity.
Subject(s)
HIV Infections , Ribonuclease H , Humans , Ribonuclease H/metabolism , Ions , Anthraquinones/pharmacology , Reverse Transcriptase Inhibitors/pharmacology , Reverse Transcriptase Inhibitors/chemistryABSTRACT
The readthrough mechanism, which skips the premature termination codon and restores the biosynthesis of the defective enzyme, is an emerging therapeutic tactic for nonsense mutation-related diseases, such as Hurler syndrome, a type of mucopolysaccharidosis. In the present study, novel triaryl derivatives were synthesized and their readthrough-inducing activities were evaluated by a luciferase reporter assay with a partial α-L-iduronidase (IDUA) DNA sequence containing the Q70X nonsense mutation found in Hurler syndrome and by measuring the enzyme activity of IDUA knockout cells transfected with the mutant IDUA gene. KY-516, a representative compound in which the meta position carboxyl group of the left ring of the clinically used ataluren was converted to the para position sulfamoylamino group, the central ring to triazole, and the right ring to cyanobenzene, exhibited the most potent readthrough-inducing activity in the Q70X/luciferase reporter assay. In Q70X mutant IDUA transgenic cells, KY-516 significantly increased enzyme activity at 0.1 µM. After the oral administration of KY-516 (10 mg/kg), the highest plasma concentration of KY-516 was above 5 µM in rats. These results indicate that KY-516, a novel triaryl derivative, exhibits potent readthrough-inducing activity and has potential as a therapeutic agent for Hurler syndrome.
Subject(s)
Mucopolysaccharidosis I , Animals , Rats , Mucopolysaccharidosis I/drug therapy , Mucopolysaccharidosis I/genetics , Codon, Nonsense , Administration, Oral , Biological Assay , TriazolesABSTRACT
To establish a simple and nondestructive method for measuring plant wound-healing ability, we characterized the fluorescence characteristics of wounds on hypocotyl of soybean seedlings during healing process. Wounds were manually created on the stem of soybean seedlings 7 days after sowing. The fluorescence time-series characteristics of the wounds were measured until 96 h after wounding using excitation emission matrix (EEM) and fluorescence images excited by wavelength of 365 nm. In the EEM of wounds, three main fluorescence peaks were observed, and the intensity decreased with time after wounding. The reddish color due to chlorophyll in fluorescence images also decreased with healing process. In addition, microscopic observation of the wounded tissue using a confocal laser microscope showed that the intensity of lignin or suberin like fluorescence increased with healing time, which might have blocked the excitation light. These results suggest that UV-excited fluorescence can be a new indicator of the healing ability of plant tissues.
Subject(s)
Glycine max , Seedlings , Wound Healing , Time Factors , Optical ImagingABSTRACT
Introduction. Carcinoma with sarcomatoid components is a highly malignant tumor exhibiting both epithelial and stromal malignant differentiation. Its tumorigenesis is associated with epithelial-mesenchymal transition (EMT), and phenotypic changes from carcinoma to sarcoma are associated with TP53 mutations. Case presentation. A 73-year-old female with bloody stool was diagnosed with rectal adenocarcinoma. She underwent trans-anal mucosal resection. Histopathologically, the tumor cells showed 2 morphologically distinct populations. One was composed of well-formed to fused glands or cribriform glands and was considered a moderately differentiated adenocarcinoma. The other consisted of pleomorphic discohesive atypical tumor cells with spindle and/or giant cell features, which was considered a sarcomatous tumor. Immunohistochemistry analysis showed that E-cadherin expression changed from positive to negative in the sarcomatous component. On the other hand, ZEB1 and SLUG were positive. Finally, she was diagnosed with carcinoma with a sarcomatoid component. We performed a mutation analysis by next genome sequencing and found KRAS and TP53 mutations in both carcinomatous and sarcomatous components. Conclusions. Immunohistochemistry and mutation analyses revealed tumorigenesis of rectal carcinoma with sarcomatoid components correlated with EMT and TP53 mutations.
Subject(s)
Adenocarcinoma , Carcinoma , Carcinosarcoma , Sarcoma , Female , Humans , Aged , Immunohistochemistry , Sarcoma/pathology , Adenocarcinoma/diagnosis , Adenocarcinoma/genetics , Adenocarcinoma/pathology , Carcinogenesis , Carcinosarcoma/pathologySubject(s)
Granulosa Cell Tumor , Ovarian Neoplasms , Humans , Female , Granulosa Cell Tumor/pathology , Mesentery/pathologyABSTRACT
BACKGROUND: Communication skills are a necessary competency in veterinary medicine, and shared decision-making (SDM) between practitioners and patients is becoming increasingly important in veterinary practice as in human medicine. There are few studies that have quantitatively measured SDM in veterinary health care, and the relationship between SDM and consultation satisfaction is unknown. The purpose of this study was to investigate the status of SDM implementation in veterinary hospitals and the relationship between SDM implementation and consultation satisfaction among pet owners. We conducted a cross-sectional study using self-administered questionnaires among pet owners and veterinarians. In total, 77 pet owners who visited a veterinary clinic and 14 veterinarians at the clinics participated in this study. After a veterinary clinic visit, owners were asked to rate their decision-making preferences using the Shared Decision Making Questionnaire for patients (SDM-Q-9) adapted for veterinary medicine, as well as their satisfaction with the consultation. The corresponding veterinarians were asked to complete the veterinary version of the survey (SDM-Q-Doc). RESULTS: Most pet owners (64.9%) preferred SDM in veterinary consultations. Cronbach's alpha coefficient of 0.84 for the veterinary SDM-Q-9 and 0.89 for the veterinary SDM-Q-Doc both confirmed high reliability. The Spearman's correlation coefficient between the SDM-Q-9 and consultation satisfaction was 0.526 (p < 0.001), which was significant. The SDM-Q-Doc was not significantly correlated with either the SDM-Q-9 or pet owner consultation satisfaction. We conducted a sensitivity analysis of correlations among veterinarians; responses on the SDM-Q-Doc to examine the association between the SDM-Q-Doc and SDM-Q-9 and owner satisfaction; the results remained the same and no association was found. CONCLUSIONS: Our findings suggest that evaluation of SDM among pet owners was associated with their satisfaction with veterinary consultation. Veterinarians may be able to improve the satisfaction level of pet owners by adopting a consultation method that increases SDM. We did not consider the content of veterinary care or the number of visits to the veterinary clinic; future studies should be conducted to confirm the validity of our results.
Subject(s)
Decision Making, Shared , Veterinarians , Animals , Cross-Sectional Studies , Decision Making , Humans , Patient Participation , Personal Satisfaction , Referral and Consultation , Reproducibility of Results , Surveys and QuestionnairesABSTRACT
Staphylococcal superantigen-like 12 (SSL12) is reported to evoke the degranulation in murine mast cells. The allelic variant of SSL12 in the genome of reference strain NCTC8325 induced the degranulation of murine mast cells, that of MRSA252 strain did not, nevertheless relatively high sequence similarity (82%). To identify responsible amino acid residues of SSL12 for mast cell activation, we created a series of domain swap mutants and amino acid substitution mutants between the active and inactive variants. The mutants that harbored oligonucleotide/oligosaccharide binding (OB)-fold domain of the active variant activated mast cells. The replacement at position 56 (L56F) in the OB-fold domain diminished the mast cell stimulatory activity, and the combinatorial substitutions L56F/K92E, L56F/D95S, and L56F/S100V abolished the stimulatory activities of the mutant that harbored OB-fold domain of the active variant and the intact active variant. These indicate that the responsive elements of SSL12 for mast cell activation are in the OB-fold of SSL12, and L56 would be an essential amino acid residue for the activation of mast cells. The findings would contribute to the understanding of the molecular mechanism of SSL12 for mast cell activation and the development of toxoids preventing allergic inflammations associated with Staphylococcus aureus.
Subject(s)
Staphylococcal Infections , Superantigens , Amino Acids/metabolism , Animals , Mast Cells/metabolism , Mice , Staphylococcal Infections/metabolism , Staphylococcus aureus/chemistry , Staphylococcus aureus/genetics , Staphylococcus aureus/metabolism , Superantigens/genetics , Superantigens/metabolismABSTRACT
The nucleolus is the site of ribosome assembly and formed through liquid-liquid phase separation. Multiple ribosomal DNA (rDNA) arrays are bundled in the nucleolus, but the underlying mechanism and significance are unknown. In the present study, we performed high-content screening followed by image profiling with the wndchrm machine learning algorithm. We revealed that cells lacking a specific 60S ribosomal protein set exhibited common nucleolar disintegration. The depletion of RPL5 (also known as uL18), the liquid-liquid phase separation facilitator, was most effective, and resulted in an enlarged and un-separated sub-nucleolar compartment. Single-molecule tracking analysis revealed less-constrained mobility of its components. rDNA arrays were also unbundled. These results were recapitulated by a coarse-grained molecular dynamics model. Transcription and processing of ribosomal RNA were repressed in these aberrant nucleoli. Consistently, the nucleoli were disordered in peripheral blood cells from a Diamond-Blackfan anemia patient harboring a heterozygous, large deletion in RPL5 Our combinatorial analyses newly define the role of RPL5 in rDNA array bundling and the biophysical properties of the nucleolus, which may contribute to the etiology of ribosomopathy.
Subject(s)
Cell Nucleolus , Ribosomal Proteins , Cell Nucleolus/genetics , Cell Nucleolus/metabolism , DNA, Ribosomal/genetics , DNA, Ribosomal/metabolism , Humans , Ribosomal Proteins/genetics , Ribosomal Proteins/metabolismABSTRACT
mRNA expression varies in human cancers. Such altered mRNA expression is negatively regulated by the expression of microRNAs (miRNAs), which play an important role in human tumorigenesis. According to this theory, inverse mRNA/miRNA expression may be a direct driver of cancer development, and certain genetic events may occur prior to the development of any discernible histological abnormalities. We examined the inverse expression between mRNAs and their corresponding miRNAs in colorectal cancer (CRC) and adjacent normal mucosa and performed pathway analysis to identify mRNA/miRNA networks. The cancer samples were divided into first (20 cases) and second (24 cases) cohorts, and 48 samples were obtained from two sections of the normal mucosa adjacent to the tumors from the second cohort. We investigated mRNAs with commonly altered expression in CRC and adjacent normal mucosa using isolated cancer glands and normal crypts from the first cohort, compared with that of distal normal crypts, using an array-based method. As a result, significant inverse correlations between CEACAM1 and miRNA-7114-5p and between AK1 and miRNA-6780-5p were found in CRC and adjacent normal mucosa. We validated these correlations in the second cohort using RT-PCR. To confirm these findings, transfection and immunohistochemical assays were also performed, which verified the inverse correlation between CEACAM1 and miRNA-7114-5p. Our findings suggest that the inverse correlations between the CEACAM1/miRNA-7114-5p and possibly AK1/miRNA-6780-5p pairs play an important role in early CRC development, and may help identify potential molecular targets for early detection of CRC.
Subject(s)
Colorectal Neoplasms , MicroRNAs , Colorectal Neoplasms/pathology , Gene Expression Regulation, Neoplastic , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Mucous Membrane/metabolism , Mucous Membrane/pathology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Transcription Factors/metabolismABSTRACT
In eukaryotic nuclei, most genes are transcribed by RNA polymerase II (RNAP2), whose regulation is a key to understanding the genome and cell function. RNAP2 has a long heptapeptide repeat (Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7), and Ser2 is phosphorylated on an elongation form. To detect RNAP2 Ser2 phosphorylation (RNAP2 Ser2ph) in living cells, we developed a genetically encoded modification-specific intracellular antibody (mintbody) probe. The RNAP2 Ser2ph-mintbody exhibited numerous foci, possibly representing transcription "factories," and foci were diminished during mitosis and in a Ser2 kinase inhibitor. An in vitro binding assay using phosphopeptides confirmed the mintbody's specificity. RNAP2 Ser2ph-mintbody foci were colocalized with proteins associated with elongating RNAP2 compared with factors involved in the initiation. These results support the view that mintbody localization represents the sites of RNAP2 Ser2ph in living cells. RNAP2 Ser2ph-mintbody foci showed constrained diffusional motion like chromatin, but they were more mobile than DNA replication domains and p300-enriched foci, suggesting that the elongating RNAP2 complexes are separated from more confined chromatin domains.
Subject(s)
Molecular Imaging , RNA Polymerase II/metabolism , RNA Probes/metabolism , Transcription, Genetic , Cell Nucleus/metabolism , Cell Survival , HeLa Cells , Humans , Interphase , Phosphorylation , Phosphoserine/metabolismABSTRACT
In eukaryotic nuclei, chromatin loops mediated through cohesin are critical structures that regulate gene expression and DNA replication. Here, we demonstrate a new method to see endogenous genomic loci using synthetic zinc-finger proteins harboring repeat epitope tags (ZF probes) for signal amplification via binding of tag-specific intracellular antibodies, or frankenbodies, fused with fluorescent proteins. We achieve this in two steps: First, we develop an anti-FLAG frankenbody that can bind FLAG-tagged proteins in diverse live-cell environments. The anti-FLAG frankenbody complements the anti-HA frankenbody, enabling two-color signal amplification from FLAG- and HA-tagged proteins. Second, we develop a pair of cell-permeable ZF probes that specifically bind two endogenous chromatin loci predicted to be involved in chromatin looping. By coupling our anti-FLAG and anti-HA frankenbodies with FLAG- and HA-tagged ZF probes, we simultaneously see the dynamics of the two loci in single living cells. This shows a close association between the two loci in the majority of cells, but the loci markedly separate from the triggered degradation of the cohesin subunit RAD21. Our ability to image two endogenous genomic loci simultaneously in single living cells provides a proof of principle that ZF probes coupled with frankenbodies are useful new tools for exploring genome dynamics in multiple colors.
Subject(s)
Cell Nucleus , Chromatin , Chromatin/genetics , Epitopes , Genomics , ZincABSTRACT
Peroxisome proliferator-activated receptor γ (PPARγ) modulators are expected to exert anti-diabetic effects without PPARγ-related adverse effects, such as fluid retention, weight gain, and bone loss. The present study showed that the novel tetrazole derivative KY-903 exerted similar selective PPARγ partial agonist properties to INT-131, a known PPARγ modulator, in transactivation assays, and decreased plasma glucose and triglyceride levels with increases in adiponectin levels in diabetic KK-Ay mice. These effects were similar to those of pioglitazone. Pioglitazone, but not KY-903, increased adipose tissue and heart weights. In pre-adipocytes (3T3-L1), KY-903, in contrast to pioglitazone, increased adiponectin mRNA levels without adipocyte differentiation, indicating anti-diabetic effects via adiponectin without adipogenesis. In ovariectomized rats fed a high-fat diet (OVX/HFD), KY-903 and pioglitazone decreased plasma triglyceride and non-esterified fatty acid levels and increased adiponectin levels, indicating insulin sensitization via adiponectin. KY-903 reduced body weight gain and adipose tissue weight, while pioglitazone increased heart weight and markedly reduced bone mineral density. In mesenchymal stem cell-like ST2 cells, KY-903 slightly reduced osteoblast differentiation without adipocyte differentiation, while pioglitazone markedly reduced it with adipocyte differentiation. In conclusion, KY-903 is a novel PPARγ modulator that exerts anti-diabetic effects without body weight gain or cardiac hypertrophy in diabetic mice and anti-obesity effects with minor bone loss in OVX/HFD, possibly due to increases in adiponectin levels without adipogenesis.
Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/pharmacology , Obesity/drug therapy , PPAR gamma/agonists , 3T3-L1 Cells , Adipogenesis/drug effects , Adiponectin/analysis , Adiponectin/metabolism , Animals , Blood Glucose/drug effects , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/genetics , Diet, High-Fat/adverse effects , Disease Models, Animal , Drug Evaluation, Preclinical , Female , Hypoglycemic Agents/therapeutic use , Lipid Metabolism/drug effects , Male , Mice , Mice, Transgenic , Obesity/blood , Obesity/etiology , PPAR gamma/metabolism , Pioglitazone/pharmacology , Pioglitazone/therapeutic use , Rats , Tetrazoles/chemistry , Triglycerides/blood , Triglycerides/metabolism , Weight Gain/drug effectsABSTRACT
A novel series of 7-substituted-2-[3-(2-furyl)acryloyl]-6-tetrazolyl-1,2,3,4-tetrahydroisoquinoline derivatives were synthesized to clarify structure-activity relationships for peroxisome proliferator-activated receptor γ (PPARγ) partial agonist activity and identify more efficacious PPARγ partial agonists with minor adverse effects. Among the derivatives synthesized, compound 26v with a 2-(2,5-dihydropyrrol-1-yl)-5-methyloxazol-4-ylmethoxy group at the 7-position of the tetrahydroisoquinoline structure exhibited stronger PPARγ agonist and antagonist activities (EC50 = 6 nM and IC50 = 101 nM) than previously reported values for compound 1 (EC50 = 13 nM and IC50 = 512 nM). Compound 26v had very weak protein tyrosine phosphatase 1B (PTP1B) inhibitory activity and showed higher oral absorption (Cmax = 11.4 µg/mL and area under the curve (AUC) = 134.7 µg·h/mL) than compound 1 (Cmax = 7.0 µg/mL and AUC = 63.9 µg·h/mL) in male Sprague-Dawley (SD) rats. A computational docking calculation revealed that 26v bound to PPARγ in a similar manner to that of compound 1. In male Zucker fatty rats, 26v and pioglitazone at 10 and 30 mg/kg for 4 weeks similarly reduced plasma triglyceride levels, increased plasma adiponectin levels, and attenuated increases in plasma glucose levels in the oral glucose tolerance test, while only pioglitazone decreased hematocrit values. In conclusion, 6-tetrazolyl-1,2,3,4-tetrahydroisoquinoline derivatives provide a novel scaffold for selective PPARγ partial agonists and 26v attenuates insulin resistance possibly by adiponectin enhancements with minor adverse effects.