Polymeric micelles, which are formed by the self-assembly of block copolymers, can load various substances and have received attention as drug carriers. Negatively charged nucleic acids such as DNA or RNA are some of the drugs delivered by polyion complex-based polymeric micelles (polyplex micelles). Polyplex micelles are expected to be nonviral gene carriers instead of viral vectors, which have several problems including safety, the limited size of the loading gene, and productivity. In this review, recent studies by our group on smart polyplex micelles delivering genes will be introduced.

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Whether or not alkaline reduced water (ARW) has a positive effect on obesity is unclear. This study aims to prove the positive effect of ARW in high-fat (HF) diet-induced obesity (DIO) in C57BL/6 mice model. Toward this, obesity was induced by feeding the C57BL/6 male mice with high-fat diet (w/w 45% fat) for 12 weeks. Thereafter, the animals were administered with either ARW or tap water. Next, the degree of adiposity and DIO-associated parameters were assessed: clinico-pathological parameters, biochemical measurements, histopathological analysis of liver, the expression of cholesterol metabolism-related genes in the liver, and serum levels of adipokine and cytokine. We found that ARW-fed mice significantly ameliorated adiposity: controlled body weight gain, reduced the accumulation of epididymal fats and decreased liver fats as compared to control mice. Accordingly, ARW coordinated the level of adiponectin and leptin. Further, mRNA expression of cytochrome P450 (CYP)7A1 was upregulated. In summary, our data shows that ARW intake inhibits the progression of HF-DIO in mice. This is the first note on anti-obesity effect of ARW, clinically implying the safer fluid remedy for obesity control.

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The aim of this study was to determine whether α-lipoic acid (LA) is effective in blunting the detrimental effect of light to transformed retinal ganglion cells (RGC-5 cells) in culture. In this study, RGC-5 cells were exposed to light (400–760 nm; 1000 lx) for 48 h with or without LA. For cell assessment, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 4-[3-(-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetzolio]-1,3-benzene disulfonate (WST-1) reduction assays were used to assess cell and mitochondrial viability respectively. Furthermore, cells were stained for reactive oxygen species (ROS), Apoptosis DNA breakdown and Apoptosis membrane alteration. Antioxidant-capacity, glutathione (GSH) and gluthathione-S-transferase (GST) were determined as well. Light reduced cell viability, affected mitochondrial function, increased the number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL)-positive cells and enhanced labelling for ROS. These effects were all attenuated by the presence of LA. LA also stimulated GSH and GST. These findings support the view that light can affect mitochondria which could lead to retinal ganglion cell apoptosis and LA can blunt by decreasing ROS generation and stimulating GSH and GST.

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It has been reported that the activity of mitochondrial aconitase (m-aconitase) is rapidly inhibited in a variety of cells when exposed to nitric oxide (NO). In present study, we found that NO significantly increased the number of surviving neurons via enhanced mitochondrial functions with simultaneous addition of the [Fe(II)(β-citryl-L-glutamate; β-CG)] complex. In vitro, a variety of aconitase-inhibitors, such as fluorocitrate, cyanide ion, ferricyanide ([Fe(CN)₆]), and various oxidants including superoxide anion, inhibited the activity of m-aconitase even in the presence of Fe(II), whereas a NO-donor, nitroprusside (SNP) ([Fe(CN)₅NO]), was the only agent that significantly increased activity of that enzyme. Therefore, it is reasonable to assume that NO released from SNP promotes Fe-dependent activation of aconitase. All other tested NO-donors, including 3-morpholino-sydnonimine (SIN), Deta NONOate (NOC18), and NaNO₂, also promoted activation of m-aconitase in time- and dose-dependent manners in the presence of Fe(II). The promoting effects of the NO-donors on activation disappeared with the addition of NO-scavengers. In intact mitochondria, all tested NO-donors promoted reactivation of aconitase in a dose-dependent manner in the presence of Fe(II), whereas that was not seen in its absence. These findings suggest that NO released from NO-donors promotes Fe-dependent activation of aconitase. In mixed neuronal and glial cultures, NO-donors except for SNP enhanced mitochondrial activity at low concentrations. Furthermore, simultaneous addition of the [Fe(II)(β-CG)] complex significantly enhanced those activities and greatly increased the number of surviving neurons. Thus, NO can carry Fe ions into m-aconitase via the guide of the tag of β-CG addressed to the enzyme.

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The roots of Gypsophila oldhamiana are rich in triterpenoid saponins with antitumor properties. Although previous reports have revealed the anticancer potency of some Gypsophila species, the underlying molecular mechanisms of this activity have not been studied in detail. The purpose of the present study was to prepare a triterpenoid saponin-rich G. oldhamiana root extract (TGOE) determined by LC-electrospray ionization (ESI)-MSⁿ for biological studies and to evaluate the different anti-proliferative activities and apoptotic effects of TGOE on human hepatoma SMMC-7721 and normal human hepatic L02 cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that TGOE selectively inhibited the proliferation of SMMC-7721 cells in a dose-dependent manner with IC₅₀ value of 19.50±3.63 µg/mL, while the cytotoxic effects of TGOE on L02 cells were much lower with IC₅₀ value of 40.48±3.74 µg/mL. Analysis of apoptotic morphological changes and flow cytometry indicated that TGOE might preferentially induce apoptosis in SMMC-7721 cells, while exhibited much lower effects on L02 cells. Western blot analysis showed that the different apoptotic effects of TGOE on SMMC-7721 and L02 cells were due to different protein regulation of caspase-3 and mitogen activated protein kinases (MAPKs). TGOE significantly activated caspase-3 and increased the phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), while decreased the phosphorylation of p38 in SMMC-7721 cells. However, the expression of these proteins was not statistically changed in L02 cells, except for the up-regulation of p38 phosphorylation. These results suggest that TGOE may have potential beneficial effects against hepatocellular carcinoma.

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Red ginseng (the steamed root of Panax ginseng C.A. MEYER, Araliaceae), which contains ginsenosides as its main constituents, is frequently used to treat tumor, inflammation, diabetes, stress and acquired immunodeficiency syndrome in Asian countries. Of these ginsenosides, only protopanaxadiol compound K has been reported to abolish the cytoprotective phenotype of human immunodeficiency virus type 1 (HIV-1)-transfected human macrophages. Here, we investigated the anti-cytoprotective effect of protopanaxatriol ginsenoside Rh1 on Tat-expressing cytoprotective CHME5 cells and D3-infected human primary macrophages. Treatment with ginsenoside Rh1 in the presence of lipopolysaccharide/cycloheximide (LPS/CHX) potently abolished the cytoprotective phenotype of Tat-transduced CHME5 cells as well as D3-infected human primary macrophages. Ginsenoside Rh1 significantly inhibited LPS/CHX-induced Akt phosphorylation, as well as mammalian target of rapamycin and Bcl-2-associated death promoter activation in both cell types. Furthermore, ginsenoside Rh1 inhibited pyruvate dehydrogenase lipoamide kinase isozyme 1 (PDK-1) phosphorylation. However, ginsenoside Rh1 did not inhibit phosphoinositide 3-kinase phosphorylation. Ginsenosides Rh1 in the presence of miltefosine (5 µM) additively increased the anti-cytoprotective activity against HIV-1 Tat-expressing macrophages. On the basis of these findings, we propose that ginsenoside Rh1 could possibly eliminate HIV-1 infected macrophages by inhibiting the PDK1/Akt pathway.

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This study aimed to show if two different sulphur containing drugs sulbutiamine and acetylcysteine (NAC) could attenuate the effects of two different insults being serum deprivation and glutamate/buthionine sulfoximine (GB)-induced death to transformed retinal ganglion cell line (RGC-5) in culture. Cells were exposed to either 5 mM of GB for 24 h or serum deprivation for 48 h with inclusion of either NAC or sulbutiamine. Cell viability, microscopic evidence for apoptosis, caspase 3 activity, reactive oxygen species (ROS), glutathione (GSH), catalase and gluthathione-S-transferase (GST) were determined. The effects of NAC and sulbutiamine on the oxidative stress related transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf-2) levels and its dependent phase II enzyme haemeoxygenase-1 (HO-1) were carried out using Western blot and quantitative-polymerase chain reaction (PCR). NAC and sulbutiamine dose-dependently attenuated serum deprivation-induced cell death. However NAC but not sulbutiamine attenuated GB-induced cell death. NAC and sulbutiamine both independently stimulated the GSH and GST production but scavenged different types of ROS with different efficacy. Moreover only sulbutiamine stimulated catalase and significantly increased Nrf-2 and HO-1 levels. In addition, the pan caspase inhibitor, benzoylcarbonyl-Val-Ala-Asp-fluoromethyl ketone (z-VAD-fmk) attenuated the negative effect of serum deprivation while the necroptosis inhibitor (necrostatin-1) counteracted solely an insult of GB. The neuroprotective actions of NAC and sulbutiamine in GB or serum-deprivation insult are therefore different.

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Schwann cell injury is observed in diabetic neuropathy. It is speculated that glycolaldehyde (GA), a precursor of advanced glycation end products (AGEs), contributes to the pathogenesis and development of diabetic neuropathy. Here, we demonstrated for the first time that GA at near-physiological concentration decreased the viability of rat Schwann cells. In contrast, methylglyoxal, glyoxal, and 3-deoxyglucosone, all of which are AGE precursors, had no effects on cell viability. It is well known that methylglyoxal causes oxidative damage. In the present study, however, GA failed to induce reactive oxygen species production in Schwann cells. The addition of glutathione (GSH) or N-acetyl-L-cysteine protected Schwann cells from the loss of viability induced by GA. Moreover, GA increased intracellular GSH level and γ-glutamylcysteine synthetase mRNA level. Flow cytometric analysis revealed that GA increased multidrug-resistance-associated protein 1 (MRP1) level as well. Moreover, we demonstrated that the knockdown of MRP1 with small interfering RNA (siRNA) enhanced the loss of cell viability induced by GA. Taken together, these findings suggest that MRP1, together with GSH, plays an important role in the GA-induced toxicity in Schwann cells.

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Telekin, a eudesmane-type sesquiterpene lactone compound isolated from Chinese folk medicine Carpesium divaricatum, has been reported to strongly inhibit the proliferation of cancer cells. In this study, the involvement of a mitochondria-mediated pathway in the pro-apoptotic action of telekin was investigated in human hepatocellular carcinoma cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays showed that telekin exhibited excellent anti-proliferation activity in hepatocellular carcinoma cells and low cytotoxicity to normal hepatocyte cells. Telekin-induced apoptosis was characterized by chromatin condensation, formation of apoptotic bodies, and exposure of phosphatidylserine on the extracellular surface, as revealed by 4,6-diamidino-2-phenylindole (DAPI) nuclear staining and flow cytometry. Flow cytometry analysis showed that telekin induced the loss of mitochondrial membrane potential (MMP), as well as increased the levels of intracellular free calcium and reactive oxygen species (ROS). Additionally, Western blot results demonstrated that telekin induced the decrease in Apaf-1 and Bcl-2 expression, increase in Bax expression, release of cytochrome C, and activation of caspase-9 and caspase-3 in HepG-2 cells. These findings indicate that telekin activates the mitochondria-mediated apoptotic pathway in hepatocellular carcinoma cells and may merit further investigation as a potential therapeutic agent for the treatment of hepatocellular carcinoma.

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Erythropoietin (EPO), an essential hormone for erythropoiesis, can provide protection against myocardial ischemia/reperfusion (I/R) injury and hypoxic apoptosis. GATA-4 is a zinc finger transcription factor, and its activation and post-translational modification are essential components in the transcriptional response to hypoxia. GATA-4 has also been reported to play a role in the cellular mechanisms of EPO-induced myocardial protection against I/R injury. In this study, we aimed to investigate the influence of EPO on GATA-4 protein stability and post-translational modification under hypoxic conditions without reperfusion. EPO induced cell viability under long-term hypoxia. EPO significantly increased phosphorylation of GATA-4 via the extracellular signal-regulated kinase (ERK) signaling pathway and reduced hypoxia-induced GATA-4 ubiquitination, which enhanced GATA-4 stability under hypoxia. ERK activation by over-expression of constitutively active mitogen-activated protein kinase 1 (MEK1) strongly increased GATA-4 phosphorylation and its protein levels and decreased GATA-4 ubiquitination under hypoxia. Despite ERK activation, GATA-4 ubiquitination was not affected under hypoxia in a GATA-4-S105A mutant. Under hypoxic condition without reperfusion, EPO-induced ERK activation was associated with post-translational modification of GATA-4, mediated by enhancement of phosphorylation of GATA-4 at Ser-105. Subsequent attenuation of GATA-4 ubiquitination led to increases in GATA-4 protein stability, which resulted in increased cell viability under hypoxia.

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Ultraviolet (UV) radiation from sunlight induces matrix metalloproteinase (MMP) expression, which are responsible for collagenous extracellular matrix proteins breakdown in skin, causing photoaging. Sauchinone is reported to have various bioactivity such as antioxidative, hepatoprotective, and anti-inflammatory effects. In the present study, we investigated the protective effect of sauchinone against UVB (50 mJ/cm²)-induced photoaging in HaCaT human epidermal keratinocytes. Sauchinone, at 5–40 µM, significantly protected keratinocytes against UVB-induced damage as assessed by cell viability and toxicity assay. Additionally, sauchinone, at 20–40 µM, prevented the upregulation of MMP-1 proteins and reduction of type 1 collagen induced by UVB. Other assays revealed that, in keratinocytes, sauchinone decreased reactive oxygen species (ROS) production and increased glutathione levels and heme oxygenase-1. Sauchinone also inhibited UVB-induced phosphorylation of mitogen-activated protein kinase (MAPK) signaling pathways. These results demonstrated that sauchinone protects skin keratinocytes through inhibition of extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38 MAPK signaling via upregulation of oxidative defense enzymes.

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We characterize umbelliferone, a derivative of 2,4-dihydroxycoumaric acid, as a substrate of polyphenol oxidase. This enzyme hydroxylates umbelliferone to esculetin, its o-diphenol, and then oxidizes it to o-quinone. The findings show that umbelliferone, an intermediate in one of the coumarin biosynthesis pathways, may be transformed into its o-diphenol, esculetin, which is also an intermediate in the same pathway. The activity of the enzyme on umbelliferone was followed by measuring the consumption of oxygen, spectrophotometrically and by HPLC. Kinetic constants characterizing the hydroxylation process were: k_cat=0.09±0.02 s⁻¹ and K_m=0.17±0.06 mM. The o-diphenol, esculetin, was a better substrate and when its oxidation was followed spectrophotometrically, the kinetic constants were: k_cat=1.31±0.25 s⁻¹ and K_m=0.035±0.002 mM. Both compounds therefore can be considered as alternative substrates to L-tyrosine and L-3,4-dihydroxyphenylalanine (L-DOPA), since both indirectly inhibit melanogenesis.

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In this study, the pharmacokinetic and pharmacodynamic properties of Lys³⁵, Met^N-terminal, and Lys¹⁷-mono-PEGylated recombinant human granulocyte colony stimulating factor (rhG-CSF) positional isomers were evaluated in rats. The in vitro biological activities of Lys³⁵, Met^N-terminal, and Lys¹⁷-mono-PEGylated rhG-CSF were determined by examining NFS-60 cell proliferation. Plasma concentrations of rhG-CSF and white blood cell (WBC) counts and absolute neutrophil conunt (ANC) were measured and pharmacokinetic and pharmacodynamic properties were determined after a single subcutaneous administration of the Lys³⁵, Met^N-terminal, or Lys¹⁷ isomers at 0.1 mg/kg in rats. The in vitro biological activities of Lys³⁵, Met^N-terminal, and Lys¹⁷-mono-PEGylated rhG-CSF individual positional isomers were 20.1%, 37.4%, and 15.3%, respectively, that of rhG-CSF. However, all three mono-PEGylated rhG-CSF isomers had a greater blood half-life (T_1/2) and in vivo efficacy as determined by WBC counts and ANC than rhG-CSF, but no significant difference was observed between the three isomers. In conclusion, Lys³⁵, Met^N-terminal, and Lys¹⁷-mono-PEGylated rhG-CSF individual positional isomers exhibit an enhanced the in vivo pharmacokinetics and pharmacodynamics. Furthermore, three isomers have comparable in vivo pharmacokinetic and pharmacodynamic properties, but their in vitro biological activities are PEGylation site dependent.

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Pyrrole-imidazole (PI) polyamides are a novel group of gene-silencing compounds, which bind to a minor groove of double stranded (ds)DNA in a sequence-specific manner. To explore the RNA binding properties of PI polyamides targeting rat transforming growth factor-β1 (TGF-β1 Polyamide) and influenza A virus (PA polyamide), we designed dsRNAs with an identical sequence to the target DNA and analyzed RNA binding properties of the polyamide. Biacore assay showed fast binding of TGF-β1 Polyamide to the dsRNA, whereas mismatch polyamide did not bind to the dsRNA. Dissociation equilibrium constant (KD) value was 6.7×10⁻⁷ of the target dsRNA. These results indicate that PI polyamide could bind to RNA with a 2 log lower binding affinity than its DNA-binding affinity. We designed a PI polyamide targeting the panhandle stem region of influenza A virus. KD value of the PI polyamide to dsRNA targeting influenza A virus was 4.6×10⁻⁷. Gel-shift assay showed that TGF-β1 and PA polyamides bound to the appropriate dsDNA, whereas these PI polyamides did not show obvious gel-shift with the appropriate dsRNA. Structural modeling suggests that PI polyamide binds to the appropriate B-form dsDNA in the minor groove, whereas it does not fit in the minor groove to dsRNA. Thus PI polyamides have a lower binding affinity with target dsRNA than they do with dsDNA. The distinct binding properties of PI polyamides to dsRNA and dsDNA may be associated with differences of secondary structure and chemical binding properties between target RNA and DNA.

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RecQ5, a member of the RecQ helicase family, maintains genome stability via participation in many DNA metabolic processes including DNA repair, DNA resolution, and RNA transcription, processes occurring in the nucleus. Previously, we reported that RecQ5 and Rad51, also involved in DNA repair, become co-localized in nuclei when co-expressed in cultured cells. Nuclear localization of RecQ5 appears to be important for cellular function along with Rad51. However, little is known about the nuclear localization of RecQ5. Here, we generated enhanced green fluorescent protein (EGFP)-tagged RecQ5 transgenic flies and analyzed localization of this protein in early embryos by live imaging. In syncytial embryos, RecQ5 was localized synchronously in interphase nuclei, and spread repeatedly over the embryos in mitosis. Thus, RecQ5 was transported into nuclei at the early interphase. Furthermore, we examined the subcellular localization of a series of truncated forms of Drosophila RecQ5 in cultured cells to determine the nuclear localization signal (NLS). Entire coding or deleted RecQ5 sequences of various sizes were ligated into EGFP vectors, which were then used to transfect cultured Drosophila cells. The region responsible for nuclear localization of Drosophila RecQ5 contained a short stretch of positively charged basic amino acids, 2 of which were particularly important for the nuclear localization. This stretch was sufficient for nuclear localization when fused with EGFP. Although the NLS of Drosophila RecQ5 was distinct from that of human RECQL5 in terms of position and amino acid sequence, this fly RecQ5 protein was translocated into the nucleus by an NLS.

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Diacylglycerol acyltransferase 2 (DGAT2) is one of two distinct DGAT enzymes that catalyze the last step in triacylglycerol (TG) synthesis. Findings from previous studies suggest that inhibition of DGAT2 is a promising strategy for the treatment of hepatic steatosis and insulin resistance. Here, we identified compound 122 as a potent and selective inhibitor of human DGAT2, which appeared to act competitively against oleoyl-CoA in vitro. The selective inhibition of DGAT2 was also confirmed by the reductions in enzymatic activity and de novo TG synthesis in DGAT2-overexpressing HEK293 cells and hepatic cells HepG2. Compound 122, as a newly identified inhibitor of DGAT2, will be useful for the research on DGAT2-related lipid metabolism as well as the development of therapeutic drug for several metabolic diseases.

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We examined the ability of Aeromonas hydrophila to lyse elastin. Eight of 13 strains showed elastolytic activity on agar medium containing elastin and 5 strains did not. In order to examine the involvement of the metalloprotease of A. hydrophila (AMP) in elastolytic activity, we made the amp-deletion mutant strain from an elastolytic strain. The elastolytic activity of the strain decreased with this deletion. The analysis of AMP released into the culture supernatant showed that AMP appeared outside of the cell as the intermediate consisting of a mature domain and carboxy terminal (C-terminal) propeptide domain. Further analysis showed that the intermediate has the ability to lyse elastin and that loss of the C-terminal domain causes loss of the elastolytic activity of the intermediate. We then determined the nucleotide sequence of the amps of all strains used in this study. Phylogenetic analysis revealed that these AMPs were divided into three groups. The AMPs from elastolytic strains belong to group I or group II, and AMPs from non-elastolytic strains belong to group III. The distance between group I and group II is small, but group III is located separately from groups I and II. Comparison of the amino acid residues of the C-terminal domain revealed that there are 13 amino acid residues specific to the C-terminal domain of group III. This indicates that the conformation of the C-terminal propeptide domain formed by these specific amino acid residues is important for AMP to express elastolytic activity.

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In this study, a novel dry small interfering RNA (siRNA) powder for inhalation, containing chitosan and mannitol, was prepared using the supercritical carbon dioxide (CO₂) technique. Although the siRNA/chitosan powder was difficult to disperse because of a long needle-like structure, it could be reduced to fragments of 10–20 µm by manual grinding, which allowed for administration into mice. Electrophoresis revealed that the supercritical CO₂ technique and manual grinding didn’t greatly affect the integrity of the siRNA. Furthermore, the siRNA was more stable in the lungs than in blood, suggesting the utility of pulmonary delivery. Biodistribution experiments using Cy5.5-labeled siRNA demonstrated that pulmonary administration of the powder achieved a prolonged exposure of the siRNA/chitosan complex on the lung epithelial surface at a higher concentration. For the evaluation of the in-vivo gene silencing effect of the siRNA/chitosan powder, mice bearing colon26/Luc cells were used. The powder significantly inhibited the increase in luminescence intensity in the lungs, but the siRNA/chitosan solution and a non-specific dry siRNA/chitosan powder didn't, indicating the effective and specific gene silencing against the tumor cells metastasized in the lungs of mice by the siRNA/chitosan powder. These results strongly indicate that inhalable dry siRNA powders have the possibility of effective pulmonary gene silencing and that the supercritical CO₂ technique can be applied to the production.

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Atherosclerosis is caused by many factors, one of which is oxidative stress. We recently demonstrated that systemic oxidative stress increased secretory sphingomyelinase (sSMase) activity and generated ceramides in the plasma of diabetic rats. In addition, we also showed that the total ceramide level in human plasma correlated with the level of oxidized low-density lipoprotein. To investigate the relationship between ceramide species and atherogenesis during aging, we compared age-related changes in ceramide metabolism in apolipoprotein E knock out mice (apoE^−/−) and wild type mice (WT). Although the total plasma ceramide level was higher in apoE^−/− than that in WT at all ages, it decreased with increasing age. sSMase activity increased at 65 weeks (w) of age in both strains of mice. When apoE^−/− developed atherosclerosis at 15 w of age, C18:0, C22:0, and C24:0 ceramide levels in the apoE^−/− aorta significantly increased. Furthermore, at 65 w of age C16:0 and C24:1 ceramide levels were significantly higher than those in WT. These results suggested that elevation in levels of specific ceramide species due to sSMase activity contributed to atherogenesis during aging.

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Our recent work has shown that cannabidiol (CBD) exhibits the most potent direct inhibition of human cytochrome P450 1A1 (CYP1A1) among the CYP enzymes examined. However, the mechanism underlying this CBD inhibition remains to be clarified. Thus, to elucidate the structural requirements for the potent inhibition by CBD, the effects of CBD and its structurally related compounds on CYP1A1 activity were investigated with recombinant human CYP1A1. Olivetol, which corresponds to the pentylresorcinol moiety of CBD, inhibited the 7-ethoxyresorufin O-deethylase activity of CYP1A1; its inhibitory effect (IC₅₀=13.8 µM) was less potent than that of CBD (IC₅₀=0.355 µM). In contrast, d-limonene, which corresponds to the terpene moiety of CBD, only slightly inhibited CYP1A1 activity. CBD-2′-monomethyl ether (CBDM) and CBD-2′,6′-dimethyl ether inhibited CYP1A1 activity with IC₅₀ values of 4.07 and 23.0 µM, respectively, indicating that their inhibitory effects attenuated depending on the level of methylation on the free phenolic hydroxyl groups in the pentylresorcinol moiety of CBD. Cannabidivarin inhibited CYP1A1 activity, although its inhibitory potency (IC₅₀=1.85 µM) was lower than that of CBD. The inhibitory effects of Δ⁹-tetrahydrocannabinol and cannabielsoin (IC₅₀s ≈10 µM), which contain a free phenolic hydroxyl group and are structurally constrained, were less potent than that of CBDM, which contains a free phenolic hydroxyl group and is rotatable between pentylresorcinol and terpene moieties. These results suggest that the pentylresorcinol structure in CBD may have structurally important roles in direct CYP1A1 inhibition, although the whole structure of CBD is required for overall inhibition.

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FLJ00018, a heterotrimeric guanosine 5′-triphosphate (GTP)-binding protein (G protein) Gβγ subunit-activated guanine nucleotide exchange factor for Rho family small GTPases, regulates cellular responses, including cell morphological changes and gene transcriptional regulation, and targets the cellular membranes. FLJ00018 contains a Dbl homology (DH) domain in addition to a pleckstrin homology (PH) domain. Here we show that the PH domain of FLJ00018 is required for FLJ00018-induced, serum response element-dependent gene transcription. Although the PH domain of KIAA1415/P-Rex1, another Gβγ subunit-activated guanine nucleotide exchange factor for Rho family small GTPases, binds to phosphatidylinositol 3,4,5-triphosphate and phosphatidylinositol 3,4-bisphosphate, the PH domain of FLJ00018 binds to polyphosphoinositides including phosphatidylinositol 4,5-bisphosphate, and phosphatidic acid. These results suggest that FLJ00018 is targeted via its PH domain to cellular membranes.

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The pharmacological profile of BR-A-657, 2-n-butyl-5-dimethylamino-thiocarbonyl-methyl-6-methyl-3-{[2-(1H-tetrazole-5-yl)biphenyl-4-yl]methyl}-pyrimidin-4(3H)-one, a new nonpeptide AT₁-selective angiotensin receptor antagonist, has been investigated in a variety of in vitro and in vivo experimental models. In the present study, BR-A-657 displaced [¹²⁵I][Sar¹-Ile⁸]angiotensin II (Ang II) from its specific binding sites to AT₁ subtype receptors in membrane fractions of HEK-293 cells with an IC₅₀ of 0.16 nM. In a functional assay using isolated rabbit thoracic aorta, BR-A-657 inhibited the contractile response to Ang II (pD′₂: 9.15) with a significant reduction in the maximum. In conscious rats, BR-A-657 (0.01, 0.1, 1 mg/kg; intravenously (i.v.)) dose-dependently antagonized Ang II-induced pressor responses. In addition, BR-A-657 dose-dependently decreased mean arterial pressure in furosemide-treated rats and renal hypertensive rats. Moreover, BR-A-657 given orally at 1 and 3 mg/kg reduced blood pressure in conscious renal hypertensive rats. Taken together, these findings indicate that BR-A-657 is a potent and specific antagonist of Ang II at the AT₁ receptor subtype, and reveal the molecular basis responsible for the marked lowering of blood pressure in conscious rats.

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Serum total cholesterol amounts in the stroke-prone hypertensive rat (SHRSP) strain are lower than in the normotensive control strain, Wistar-Kyoto (WKY) rat. To understand the strain difference, constitutive gene expression levels of hepatic cholesterol biosynthetic enzymes in male 8-week-old SHRSP and WKY rats were comparatively examined by DNA microarray and real-time reverse transcription-polymerase chain reaction (RT-PCR) analyses. Of 22 cholesterol biosynthetic enzyme genes, expression levels of 8 genes, Pmvk, Idi1, Fdps, Fdft1, Sqle, Lss, Sc4mol, and Hsd17b7, in SHRSP were less than 50% those of the WKY rats; especially, the expression level of Sqle gene, encoding squalene epoxidase, a rate-limiting enzyme in cholesterol biosynthesis pathway, was about 20%. The gene expression level of sterol regulatory element-binding protein-2 (SREBP-2), which functions as a transcription factor upregulating gene expression of cholesterol biosynthetic enzymes, in SHRSP was about 70% of that in WKY rats. These results demonstrate the possibility that the lower serum total cholesterol level in SHRSP is defined by lower gene expression of most hepatic cholesterol biosynthetic enzymes. In particular, decreased gene expression level of Sqle gene might be the most essential factor. Moreover, the broad range of lowered rates of these genes in SHRSP suggests that the abnormal function and/or expression not only of SREBP-2 but also of one or more other transcription factors for those gene expressions exist in SHRSP.

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The patient is a 3-year-old boy who received living-donor liver transplantation (LDLT) for hepatoblastoma, with his mother as the donor. Oral tacrolimus was started at a dose of 0.3 mg every 12 h from day 1, with the dosage adjusted on the basis of trough concentrations. The levels of aspartate aminotransferase (AST), alanine transferase (ALT), and total bilirubin (T-bil) were 110 U/L, 182 U/L, and 12.6 mg/dL, respectively, when chronic rejection (CR) was pathologically diagnosed. Then, sirolimus at a dose of 1.0 mg/d was added to the tacrolimus-based regimen. The T-bil level rapidly decreased to 5.4 mg/dL, without changes in AST and ALT. Because the intracellular receptor of sirolimus and tacrolimus is FK506-binding protein 12, we switched tacrolimus to cyclosporine at a dose of 60 mg/d to avoid competitive inhibition between these 2 drugs. The target trough concentration of sirolimus and cyclosporine was set to around 15 ng/mL and 180 ng/mL, respectively. The concentration/dose ratio of sirolimus was significantly correlated with the blood cyclosporine level (r=0.5293, p<0.05), suggesting the pharmacokinetic interaction between these 2 drugs. Thereafter, the levels of AST and ALT as well as the T-bil were successfully decreased to 73 U/L, 83 U/L, and 3.0 mg/dL, respectively. These results suggest that sirolimus therapy in combination with cyclosporine may be an effective treatment against CR after liver transplantation.

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