Search

Pt-containing meta - and para -linked poly(phenyleneethynylene)s were synthesized by the dehydrochlorination coupling polymerization of PtCl 2 (PBu 3 ) 2 with m - and p -diethynylbenzenes. The formed polymers were sintered at 900 °C to obtain Pt-graphene hybrids, whose structures were examined by Raman scattering spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) measurements. Shapes─facets, terraces, and steps─with average diameters of 2.0-3.4 μm were observed by field emission scanning electron microscopy (FE-SEM). The Pt-graphene hybrids moderately adsorbed CO 2 and O 2 and slightly adsorbed ethylene and methane. Epoxidation of stilbene was carried out using Pt-graphene hybrids as catalysts to obtain stilbene oxide.

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) plays an important role in regulating the expression of glucocorticoid actions in target tissues. Overexpression of 11β-HSD1 in mouse adipose tissue causes a metabolic syndrome-like phenotype, leading to hypertension. Although, many 11β-HSD1 inhibitors have been studied, few have shown a clear ameliorative effect against hypertension. We investigated whether JTT-654, a novel 11β-HSD1 inhibitor, ameliorated hypertension and elucidated the underlying mechanisms. JTT-654 showed inhibitory effects on angiotensinogen production in cortisone-treated 3T3-L1 adipocytes and in a rat model. JTT-654 improved hypertension not only in cortisone-treated rats and spontaneously hypertensive rats (SHR), but also in SHR/NDmcr-cp rats. In the SHR study, JTT-654 and losartan showed the same degree of antihypertensive efficacy. In addition, JTT-654 ameliorated diabetic nephropathy by suppressing renal angiotensinogen production in SHR/NDmcr-cp rats. These effects of JTT-654 were independent of its insulin-sensitizing effects, and similar effects were not observed for pioglitazone, an insulin sensitizer. Moreover, JTT-654 did not affect normotension or hypothalamus-pituitary-adrenal (HPA) axis function in normal Sprague-Dawley rats. Our results indicate that JTT-654 ameliorates hypertension and diabetic nephropathy by inhibiting 11β-HSD1 in the adipose tissue, liver, and kidney., (Copyright © 2024 The Authors. Production and hosting by Elsevier B.V. All rights reserved.)

Supramolecular gels are promising as chemosensors, drug delivery systems and oil gelators. The present paper deals with photoluminescent supramolecular gels derived from phenylenediamine hydrochlorides. N -(3,5-Diaminobenzoyl)-L-alanine dodecyl ester dihydrochlorides (1L) underwent gelation in tetrahydrofuran (THF) and CHCl 3 , but not in C1-C4 alcohols, dimethyl sulfoxide (DMSO) and N,N -dimethylformamide (DMF). Compound 1L emitted blue fluorescence in the sol state and green fluorescence in the gel state. A THF solution of 1L exhibited absorption and emission maxima at wavelengths 94-104 nm and 92-110 nm longer than those in other solvents, such as methanol and ethanol, that cause no gelation of 1L. Particles with hydrodynamic diameters around 13 nm were detected in a THF solution ( c = 1.0 mM) of 1L. The gelation of 1L in THF and CHCl 3 , and the lack of gelation in MeOH were supported by molecular dynamics simulations and dynamic light scattering measurements. N -(3,5-Diaminobenzoyl)-L-alanine dodecyl ester (1L'), an HCl-free analogous compound of 1L, underwent no gelation in THF and CHCl 3 , indicating the necessity of the ammonium salt structure for gelation. The UV-vis absorption and photoluminescence spectroscopic peaks of 1L red-shifted upon aggregation, which was supported by TD-DFT calculations of monomeric and dimeric models of 1L.

Platinum-containing macrocycles (platinacycles) have gained attention due to their unique photoelectric properties. In the present study, a novel conjugated platinacycle was synthesized by the dehydrochlorination coupling reaction of a bipyridine dichloroplatinum(II) complex and a 3,6-diethynylcarbazol derivative. The structure of the platinacycle was confirmed by 1 H/ 13 C, 1 H- 1 H COSY, HMQC, HMBC, DEPT NMR spectroscopies in conjunction with DFT calculations, IR spectroscopy and MALDI-TOF mass spectrometry. The platinacycle exhibited a UV-vis absorption around 540 nm assignable to ligand-ligand charge transfer, and birefringence in DMF, possibly due to alignment of molecules.

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is the only enzyme that converts inactive glucocorticoids to active forms and plays an important role in the regulation of glucocorticoid action in target tissues. JTT-654 is a selective 11β-HSD1 inhibitor and we investigated its pharmacological properties in cortisone-treated rats and non-obese type 2 diabetic Goto-Kakizaki (GK) rats because Asians, including Japanese, are more likely to have non-obese type 2 diabetics. Systemic cortisone treatment increased fasting plasma glucose and insulin levels and impaired insulin action on glucose disposal rate and hepatic glucose production assessed by hyperinsulinemic-euglycemic clamp, but all these effects were attenuated by JTT-654 administration. Cortisone treatment also reduced basal and insulin-stimulated glucose oxidation in adipose tissue, increased plasma glucose levels after administration of the pyruvate, the substrate of gluconeogenesis, and increased liver glycogen content. Administration of JTT-654 also inhibited all of these effects. Cortisone treatment decreased basal and insulin-stimulated 2-deoxy-D-[1- 3 H]-glucose uptake in 3T3-L1 adipocytes and increased the release of free fatty acids and glycerol, a gluconeogenic substrate, from 3T3-L1 adipocytes, and JTT-654 significantly attenuated these effects. In GK rats, JTT-654 treatment significantly reduced fasting plasma glucose and insulin levels, enhanced insulin-stimulated glucose oxidation in adipose tissue, and suppressed hepatic gluconeogenesis as assessed by pyruvate administration. These results demonstrated that glucocorticoid was involved in the pathology of diabetes in GK rats, as in cortisone-treated rats, and that JTT-654 ameliorated the diabetic conditions. Our results suggest that JTT-654 ameliorates insulin resistance and non-obese type 2 diabetes by inhibiting adipose tissue and liver 11β-HSD1.

L-Tyrosine diketopiperazine (DKP) derivative 1 was synthesized, and the aggregation and photoluminescence behaviors were examined. A solution of 1 in tetrahydrofuran (THF) gradually became viscous at room temperature, and turned into the gel state 5 hours after preparation, as confirmed by dynamic viscoelasticity measurement. A solution of 1 in THF exhibited photoluminescence. Fibrous patterns were observed by transmission electron, atomic force and fluorescence microscopies. Dynamic light scattering, semiempirical molecular orbital and density functional theory calculations, as well as molecular dynamics simulations, indicated aggregate formation. This was attributed to intermolecular hydrogen bonding, mainly between the DKP moieties and partly between the urethane moieties, resulting in π-orbital overlap of the terminal phenyl groups leading to photoluminescence.

Atherogenesis has been recognized as a risk factor for lethal cardiovascular diseases. Plasma low-density lipoprotein levels are correlated to the occurrence of atherosclerosis, and their control is critical for both the prevention and treatment of these diseases. Phospholipid transfer protein (PLTP) is one of the key regulators of lipoprotein metabolism; PLTP-deficient mice exhibit decreased apolipoprotein B (apoB)-containing lipoprotein secretion and atherosclerosis, indicating the validity of PLTP as a promising therapeutic target. Here, we demonstrate a high-throughput screening (HTS) method to identify a novel chemotype of PLTP inhibitors. Instead of using recombinant proteins, we used human plasma as a source of enzymes in the first screening, so as to efficiently exclude promiscuous inhibitors. The selected compounds were further confirmed to target PLTP both biochemically and biophysically and were shown to inhibit apoB secretion from hepatic cells with no apparent toxicity. We believe that our approach is suitable for filtering out nonspecific inhibitors at an earlier stage of screening campaigns and that these compounds should have potential to be developed into drugs to treat dyslipidemia.

Staurosporine is one of the most potent and well known inhibitors of protein kinases, and it is often used to study the involvement of protein kinases in signal transduction pathways. We now report that staurosporine can induce the production of hepatocyte growth factor (HGF) independently of protein kinase inhibition. Staurosporine markedly stimulated the production of HGF in various cell types, including human skin fibroblasts. Its effect was accompanied by up-regulation of HGF gene expression. The inhibition of protein kinases appears not to be involved in staurosporine-induced HGF production, because other protein kinase inhibitors, K-252a, H-7, GF 109203X and genistein, had no HGF-inducing activity. UCN-01, 7-hydroxystaurosporine, which differs from staurosporine only in its aglycone moiety, also showed HGF-inducing activity, and inactive K-252a differs from staurosporine only in its sugar moiety. These results indicate that the sugar moiety, a six-atom ring structure, is important in the HGF-inducing activity of staurosporine. Experiments were then carried out to determine whether the characteristics of staurosporine-induced HGF production have similarities to those of HGF production stimulated by other HGF inducers. The effect of staurosporine like that of 8-bromo-cAMP and that of cholera toxin was marked in human skin fibroblasts from all four different sources, whereas the effects of epidermal growth factor and phorbol 12-myristate 13-acetate were variable depending on cells. The net increase in HGF production induced by staurosporine was not reduced in protein kinase C-depleted human skin fibroblasts. Moreover, synergistic induction of HGF was detected between staurosporine and interferon-gamma as well as between 8-bromo-cAMP and interferon-gamma. Staurosporine, however, did not increase intracellular cAMP levels in human skin fibroblasts. These results indicate that staurosporine induced HGF in different cell types via a signaling pathway similar to the cAMP-mediated pathway without increasing cAMP levels.

This study evaluated JTT-705, S-[2-([[1-(2-ethylbutyl)cyclohexyl]carbonyl]amino)phenyl]2-methylpropanethioate, as a cholesteryl ester transfer protein (CETP) inhibitor in several animal species. In vitro, JTT-705 inhibited plasma CETP activities of humans, rabbits, hamsters, cynomolgus monkeys and marmosets with IC(50) values of 5.5, 1.0, 11.7, 2.4 and 6.3 microM, respectively. The thiol form (JTP-25203) also inhibited those activities with IC(50) values of 2.8, 0.44, 0.52, 1.3 and 1.1 microM, respectively. Following oral administration to normolipidemic animals (rabbits, hamsters and marmosets), JTT-705 reduced plasma CETP activity, increased high density lipoprotein cholesterol (HDL-cholesterol), and decreased the ratio of non-HDL-cholesterol to HDL-cholesterol (atherogenic index) in all species. In marmosets, JTT-705 increased slow alpha-migrating lipoprotein (apolipoprotein E-rich HDL) in agarose gel electrophoresis, indicating that HDL metabolism in JTT-705-treated marmosets is similar to that in CETP-deficient humans. These results indicate that JTT-705 can be expected to inhibit plasma CETP activity and improve plasma lipoprotein profiles in a wide range of animal species, including humans.

Induction of hepatocyte growth factor/scatter factor (HGF/SF) may be one of the critical steps in organ regeneration, wound healing, and embryogenesis. We previously reported the production of HGF/SF from various human leukemia cell lines and a high level of the growth factor in blood and bone marrow plasma from patients with various types of leukemia. We determined here the effects of hematopoietic cytokines on HGF/SF production in human leukemia cell lines, KG-1, a myeloid cell line, and RPMI-8226, a B cell line. Interferon (IFN)-gamma remarkably stimulated HGF/SF production in both cell lines at concentrations of more than 0.1 or 1 IU/ml. IFN-alpha and IFN-beta were as effective as IFN-gamma in RPMI-8226 cells, but less than IFN-gamma in KG-1 cells. HGF/SF gene expression in KG-1 cells was also up-regulated by IFN-gamma. Granulocyte colony-stimulating factor (G-CSF), granulocyte/macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-5 and IL-6 had no effect on HGF/SF production in the 2 leukemia cell lines. We also determined the effects of HGF/SF inducers known for human fibroblasts on the growth factor production in leukemia cells. Out of phorbol 12-myristate 13-acetate (PMA), cholera toxin, IL-1 beta, and tumor necrosis factor (TNF)-alpha, the former three were as effective as IFN-gamma in KG-1 cells, but only TNF-alpha stimulated HGF/SF production in RPMI-8226 cells, whose effect was less than those of IFN-alpha, IFN-beta, and IFN-gamma. The effect of IFN-gamma in KG-1 cells was synergistic with that of PMA. In contrast with the effect in leukemia cells, HGF/SF induction by IFN-gamma in human skin fibroblasts was much less than that by PMA or cholera toxin. These results indicated that IFN-gamma is a potent inducer of HGF/SF in human leukemia cells. This finding suggests the presence of a homeostatic control mechanism in liver regeneration and repair: hepatic injury, DNA synthesis inhibition, or apoptosis caused by IFN-gamma is subsequently overcome by cytokine-induced HGF/SF, a potent promoter of liver DNA synthesis.

This report describes surgical observation and histopathological findings in a case of a 44-year-old male with leiomyoma of the iris in his left eye which had initiated from uveitis. In view of clinical efficiency and electron microscopic detection of leiomyoma, it is recommended that the tumour be excised after freezing coagulation. For confirmative diagnosis of leiomyoma of the iris, an electron microscopic detection is necessary to demonstrate the characteristic findings including cells with cigar-shaped nuclei, cytoplasmic and plasma-lemmal density, fine filaments, surface-connected vesicles and basement membrane.