The role of heat shock protein 70 in vitamin D receptor function

We previously demonstrated that the 1alpha,25-dihydroxyvitamin D(3) receptor (VDR) interacts with the constitutive heat shock protein, hsc70 in vitro, and with DnaK (Biochem. Biophys. Res. Commun. 260, 446-452, 1999). The biological significance of VDR-heat shock protein interactions, however, is unknown. To examine the role of such interactions in eukaryotic cells, we heterologously expressed VDR and RXRalpha together with a vitamin D-responsive reporter system in Saccharomyces cerevisiae and examined the consequences of heat shock protein 70 gene (SSA) deletion in these cells. We show that heterologously expressed VDR associates with the yeast cytosolic hsp70 protein, Ssa1p. Deletion of the SSA2, SSA3, and SSA4 genes and reduction of Ssa1p activity, reduces the intracellular concentrations of the VDR and its heterodimeric partner, RXRalpha and reduces the activity of a vitamin D-dependent gene. Hsp70-like chaperone proteins play a role in controlling concentrations of the VDR within the cell.

Mechanism for the transcriptional repression by c-Myc on PDGF (β)-receptor

c-Myc plays a key role in the cell cycle dependent control of the PDGF (β)-receptor mRNA. The mouse platelet-derived growth factor (PDGF) (β)-receptor promoter contains a CCAAT motif, and NF-Y plays an essential role in its transcription. Coexpression of c-Myc represses PDGF (β)-receptor luciferase reporter activity, and the CCAAT motif in the promoter is indispensable for this repression. Here we show that c-Myc binds NF-Y subunits, YB and YC, by immunoprecipitation from cotransfected COS-1 cells. The in vitro-translated c-Myc also binds the glutathione S-transferase (GST)-NF-YB fusion protein and GST-NF-YC, but not GST-NF-YA. The most C-terminal region of HAP domains of NF-YB and NF-YC, and the Myc homology boxes, but not the C-terminal bHLHZip domain, are indispensable for the coimmunoprecipitation, and also for the repression of PDGF (β)-receptor. c-Myc binds NF-Y complex without affecting the efficiency of NF-Y binding to DNA. However, the expression of Myc represses the transcriptional activation of NF-YC when fused to the GAL4 DNA binding domain. Furthermore, this repression was seen only when Myc homology boxes are present, and NF-YC contains the c-Myc binding region.

Interaction with p53 enhances binding of cisplatin-modified DNA by high mobility group 1 protein

A nonhistone chromosomal protein, high mobility group (HMG) 1, is ubiquitous in higher eukaryotic cells and binds preferentially to cisplatin-modified DNA. HMG1 also functions as a coactivator of p53, a tumor suppressor protein. We investigated physical interactions between HMG1 and p53 and the influence of p53 on the ability of HMG1 to recognize damaged DNA. Using immunochemical coprecipitation, we observed binding of HMG1 and p53. Interaction between HMG1 and p53 required the HMG A box of HMG1 and amino acids 363-376 of p53. Cisplatin-modified DNA binding by HMG1 was significantly enhanced by p53. An HMG1-specific antibody that recognized the A box of this protein also stimulated cisplatin-modified DNA binding. These data suggest that an interaction with either p53 or antibody may induce conformational change in the HMG1 A box that optimizes DNA binding by HMG1. Interaction of p53 with HMG1 after DNA damage may promote activation of specific HMG1 binding to damaged DNA in vivo and provide a molecular link between DNA damage and p53-mediated DNA repair.

Partial purification and characterization of polyphenol oxidase from banana (Musa sapientum L.) peel

Polyphenol oxidase (EC 1.10.3.1, o-diphenol: oxygen oxidoreductase, PPO) of banana (Musa sapientum L.) peel was partially purified about 460-fold with a recovery of 2.2% using dopamine as substrate. The enzyme showed a single peak on Toyopearl HW55-S chromatography. However, two bands were detected by staining with Coomassie brilliant blue on PAGE: one was very clear, and the other was faint. Molecular weight for purified PPO was estimated to be about 41 000 by gel filtration. The enzyme quickly oxidized dopamine, and its Km value (Michaelis constant) for dopamine was 3.9 mM. Optimum pH was 6.5 and the PPO activity was quite stable in the range of pH 5-11 for 48 h. The enzyme had an optimum temperature at 30 degrees C and was stable up to 60 degrees C after heat treatment for 30 min. The enzyme activity was strongly inhibited by sodium diethyldithiocarbamate, potassium cyanide, L-ascorbic acid, and cysteine at 1 mM. Under a low buffer capacity, the enzyme was also strongly inhibited by citric acid and acetic acid at 10 mM.

Y box-binding protein-1 binds preferentially to single-stranded nucleic acids and exhibits 3'-->5' exonuclease activity

We have previously shown that Y box-binding protein-1 (YB-1) binds preferentially to cisplatin-modified Y box sequences. Based on structural and biochemical data, we predicted that this protein binds single-stranded nucleic acids. In the present study we confirmed the prediction and also discovered some unexpected functional features of YB-1. We found that the cold shock domain of the protein is necessary but not sufficient for double-stranded DNA binding while the C-tail domain interacts with both single-stranded DNA and RNA independently of the cold shock domain. In an in vitro translation system the C-tail domain of the protein inhibited translation but the cold shock domain did not. Both in vitro pull-down and in vivo co-immunoprecipitation assays revealed that YB-1 can form a homodimer. Deletion analysis mapped the C-tail domain of the protein as the region of homodimerization. We also characterized an intrinsic 3'-->5' DNA exonuclease activity of the protein. The region between residues 51 and 205 of its 324-amino acid extent is required for full exonuclease activity. Our findings suggest that YB-1 functions in regulating DNA/RNA transactions and that these actions involve different domains.

Pharmacokinetics of a new parenteral oligosaccharide antibiotic, SCH27899 (Ziracin), in healthy subjects

The pharmacokinetic properties of an everninomicin antibiotic (SCH27899; Ziracin) were studied with healthy Japanese male volunteers by single (1, 3, 6, and 9 mg/kg of body weight) and multiple 60-min intravenous infusions (3, 6, and 9 mg/kg once daily for 10 consecutive days following a 2-day interval after the initial dose). At single doses the peak serum concentration and the area under the serum concentration-time curve linearly increased with the dose. While total body clearance (CL; 31.2 to 45.6 ml/kg/h) and percent cumulative urinary recovery as unchanged drug (4.9 to 7.1%) were rather constant irrespective of doses, the terminal half-life of gamma phase (t(1/2 gamma); 14.2 to 19.6 h) were slightly prolonged at the higher two doses compared with the lower two doses. With repeated doses of SCH27899, a statistically significant decrease and increase were found in CL and t(1/2 gamma) of about 36 and 21%, respectively, although these changes may be clinically irrelevant. The most commonly reported adverse events were local reactions such as erythema, pain, and palpable venous cord of mild to moderate degree around the injection site, which could be managed by changing the injection sites.

Interleukin 18 induces a synergistic enhancement of interferon gamma production in mixed murine spleen cell-tumor cell cultures: role of endogenous interleukin 12

Interleukin 18 (IL-18) reportedly synergizes with IL-12 and IL-10 for interferon gamma (IFN-gamma) synthesis and natural killer (NK) cell activity, respectively. Here we show that IL-18 alone induces low level IFN-gamma production by unstimulated Balb/c mouse spleen cells, but production is enhanced synergistically in cocultures of spleen cells and allogeneic living or fixed Yac-1 cells. Spleen cells could be primed with IL-18 prior to coculture with Yac-1 cells for IFN-gamma production, which also was observed in cocultures containing either syngeneic or xenogeneic tumor cells. IFN-gamma production in stimulated cocultures was abrogated almost completely by anti-IL-12 antibody and was unrelated to spleen cell lytic activity. IL-10 moderately inhibited IFN-gamma production induced by IL-18. Therefore, in spleen cell and tumor cell cocultures exposed to IL-18, high levels of IFN-gamma are produced by the spleen cells arising from a synergistic interaction between the exogenous IL-18 and endogenous IL-12; however, this activity is unrelated to the spleen cell lytic activity.

Transcriptional activation of the human HMG1 gene in cisplatin-resistant human cancer cells

The nonhistone chromosomal protein, high mobility group 1 (HMG1), which is ubiquitously expressed in higher eukaryotic cells, preferentially binds to cisplatin-modified DNA. The observation that HMG1 is overexpressed in cisplatin-resistant human cancer cells suggests that cisplatin resistance may be closely associated with HMG1. To decipher the mechanism of HMG1 overexpression in cisplatin-resistant cells, we isolated two overlapping genomic DNA clones containing the entire human HMG1 gene. These clones, which span approximately 15 kb of contiguous DNA, include 5 kb of the 5' flanking region as well as the entire coding sequence. We sequenced 1500 bp upstream of the first exon. The segment proximal to the transcription initiation site did not contain a TATA box but did possess an activating transcription factor site, an activator protein-2 site, one CCAAT box, and two CCAAT-binding transcription factor/nuclear factor-1 (CTF/NF-1) sites. HMG1 promoter activity was 3-10-fold higher in cisplatin-resistant KB-CP20 cells than in parental KB cells. An in vivo footprint experiment showed several differences of dimethyl sulfate modifications between KB and KB-CP20 cells in the area around the CTF/NF-1 sites. In addition, electrophoretic gel mobility shift assays showed that binding of a nuclear factor from cisplatin-resistant cells to the CTF/NF-1 site was significantly higher than the binding of the same factor from parental cells. Semiquantitative reverse transcription-PCR and Western blot analysis also showed that expression of CTF/NF-1 was 3-20-fold higher in the resistant cell line than in its parental counterpart. These findings suggest that, in cisplatin-resistant cells, the expression of HMG1 gene product is enhanced at the transcriptional level and that this probably occurs through the enhanced expression of the CCAAT binding factor, CTF/NF-1.

Translational control by the ER transmembrane kinase/ribonuclease IRE1 under ER stress

Under conditions of endoplasmic reticulum (ER) stress, mammalian cells induce both translational repression and the unfolded protein response that transcriptionally activates genes encoding ER-resident molecular chaperones. To date, the only known pathway for translational repression in response to ER stress has been the phosphorylation of eIF-2alpha by the double-stranded RNA-activated protein kinase (PKR) or the transmembrane PKR-like ER kinase (PERK). Here we report another pathway in which the ER transmembrane kinase/ribonuclease IRE1beta induces translational repression through 28S ribosomal RNA cleavage in response to ER stress. The evidence suggests that both pathways are important for efficient translational repression during the ER stress response.

Interferon gamma-dependent induction of thymidine phosphorylase/platelet-derived endothelial growth factor through gamma-activated sequence-like element in human macrophages

Thymidine phosphorylase (TP), an enzyme involved in the reversible conversion of thymidine to thymine, is identical to platelet-derived endothelial cell growth factor. TP expression in cancer cells and/or infiltrated macrophages is associated with microvessel density and poor clinical prognosis in patients with various tumor types. However, how TP expression is up-regulated in human tumors is unclear. Of various inflammatory cytokines, such as tumor necrosis factor alpha (TNF-alpha), interleukin 1 alpha (IL-1alpha), and interferon gamma (IFN-gamma), we observed that IFN-gamma most effectively increased the expression of TP in cultured human monocytic U937 cells. Transient transfection of the various deletion constructs of the TP promoter showed that the presence of the -474 to -355 sequence containing gamma-activated sequence-like element was essential for IFN-gamma-dependent activation of the TP gene. Furthermore, the IFN-gamma-dependent transcriptional activity of the promoter construct containing mutations in the gamma-activated sequence-like element was significantly decreased. An electrophoretic mobility shift assay showed that IFN-gamma increased signal transducers and activators of transcription 1 binding to gamma-activated sequence-like element in the TP promoter. IFN-gamma could be a mediator of TP expression in infiltrated monocyte/macrophages, and those monocyte/macrophages expressing TP might play an important role in malignancy and angiogenesis in various human tumors.

Discrimination of Brin Abscess and Cystic Tumor by In Vivo Proton Magnetic Resonance Spectroscopy

Proton magnetic resonance (MR) spectroscopy was evaluated for the differentiation of brain abscesses and cystic brain tumors. Proton MR spectroscopy was performed in vivo in two patients with brain abscess and eight patients with various cystic brain tumors (anaplastic astrocytoma, glioblastoma, and metastatic brain tumor). MR imaging with contrast medium demonstrated ring-like enhanced mass lesions in all patients. The various resonance peaks in proton MR spectra were assigned to metabolites according to chemical shifts. Treatment of the cystic brain lesions was based on the information from proton MR spectroscopy. Aspirated pus from one patient with brain abscess was examined using ex vivo proton MR spectroscopy. The in vivo spectra of brain abscess contained resonance peaks attributed to acetate, lactate, alanine, amino acids, and lipids in both cases, and an additional peak of succinate in one case. In vivo spectra of the neoplasms contained resonance peaks corresponding to lactate, lipids, choline, creatine, and N-acetyl aspartate. Proton MR spectroscopy is useful for discriminating brain abscess from cystic tumors with similar neuroimaging appearance, which is very important for determining the treatment strategy.

Medicinal foodstuffs. XXII. Structures of oleanane-type triterpene oligoglycosides, pisumsaponins I and II, and kaurane-type diterpene oligoglycosides, pisumosides A and B, from green peas, the immature seeds of Pisum sativum L

Two new oleanane-type triterpene oligoglycosides, pisumsaponins I and II, and two new kaurane-type diterpene oligoglycosides, pisumosides A and B, were isolated from the immature seeds (green peas) of Pisum sativum L. together with soyasaponin I, bersimoside I, dehydrosoyasaponin I, and their 6'-methyl esters. The structures of pisumsaponins and pisumosides were determined on the basis of chemical and physicochemical evidence as 22-O-malonylsoyasapogenol B 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-galactopyranosyl(1-->2)-beta-D-glucopyranosiduronic acid (22-O-malonylsoyasaponin I), sandosapogenol 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-galactopyranosyl(1-->2)-beta-D-glucopyranosiduronic acid, 17-O-beta-D-glucopyranosyl-6beta,7beta,13gamma,17-tetrahydroxy-19-kauranoic acid 19-O-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranoside, and 6beta,7beta,13beta,17-tetrahydroxy-19-kauranoic acid 19-O-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranoside, respectively.

Identification of a novel mammalian endoplasmic reticulum-resident KDEL protein using an EST database motif search

Several endoplasmic reticulum (ER)-resident proteins contain a unique C-terminal sequence (KDEL) which is required for the retention of these proteins in the ER. By searching a mouse EST database for records containing the nucleotide sequence encoding the KDEL motif, we extracted cDNAs encoding putative novel ER-resident proteins in addition to all of the known ER proteins bearing the KDEL motif. Using the sequence information obtained by this database search, we cloned the cDNA encoding a novel KDEL motif-bearing protein, ER protein 58 (EP58), sharing no significant homology to any of the known ER-resident proteins. Subcellular localization of EP58 in the ER was confirmed by cytoimmunofluorescence studies using epitope-tagged EP58. The EP58 gene was primarily expressed in embryo, placenta, and adult heart. Neither heat shock nor ER stress as tested here was sufficient to induce expression of the EP58 gene. A putative role of the N-terminal half of EP58 in protein-protein interaction is suggested by its similarity to the filamin rod domain. Similarity of the EP58 sequence with bacterial and fungus proteins suggests a possible role for EP58 in polysaccharide biosynthesis.

Dissociation of Kar2p/BiP from an ER sensory molecule, Ire1p, triggers the unfolded protein response in yeast

The unfolded protein response (UPR) is a signal transduction pathway induced by a variety of endoplasmic reticulum (ER) stresses and functions to maintain homeostasis of the cellular membrane in eukaryotes. Various ER stresses result in the accumulation of unfolded proteins in the ER, which is sensed by the transmembrane protein kinase/ribonuclease Ire1p that transmits a signal from the ER to the nucleus in Saccharomyces cerevisiae. Here we report that the yeast ER chaperone Kar2p/BiP, a member of the HSP70 family found in the ER, directly regulates the UPR by the interaction with Ire1p. In the absence of ER stress, Kar2p binds the lumenal domain of Ire1p and keeps Ire1p in an inactive unphosphorylated state. Upon exposure of cells to ER stresses, Kar2p is released from Ire1p, resulting in activation of Ire1p and signal transduction to the nucleus. Subsequently, KAR2 mRNA is induced and Kar2p accumulates in the ER in a time-dependent manner, restoring the system to the basal state. This negative autoregulation is similar to the regulation of mammalian cytosolic chaperone Hsp70 via its interaction with heat shock factor 1.

Direct interaction of p53 with the Y-box binding protein, YB-1: a mechanism for regulation of human gene expression

The Y-box binding protein, YB-1, belongs to a family of multifunctional proteins which regulate gene expression on both transcriptional and translational levels. The tumor suppressor gene p53 displays growth suppressive properties by regulating gene expression through transcriptional regulation. We now demonstrate that YB-1 directly interacts with p53 using an in vitro pull-down assay. Using immunochemical co-precipitation methods, we also found that the two proteins are bound in vivo. Deletion analysis showed that three independent domains of YB-1, one at the N-terminal and two at the C-terminal, interact with p53. Conversely, a 14 amino acid sequence at the C-terminal of p53 was required for its interaction with YB-1. Gel mobility shift assays showed that the interaction of YB-1 with p53 stimulated the sequence-specific DNA binding of p53 to its consensus sequence. By contrast, this interaction inhibited the binding of YB-1. Using a p53-responsive p21 promoter linked to a reporter gene, it can be shown that antisense expression of YB-1 inhibits the induction of this promoter by p53 in transient transfection assays. These findings delineate a straightforward mechanism for gene expression through p53-YB-1 interaction.

Depressor effect by exercise training is associated with amelioration of hyperinsulinemia and sympathetic overactivity

OBJECTIVE

In hypertensive subjects, exercise training is a therapeutic modality that not only lowers blood pressure but also corrects metabolic abnormality, such as hyperinsulinemia. Insulin causes sympatho-excitation via the modification of baroreflex, norepinephrine release, or central sympathetic outflow. However, the link between neural and metabolic changes by exercise training in hypertensive patients remains unknown. The aim of this study was to examine whether or not the blood pressure lowering effect of exercise training is associated with the improvement of insulin sensitivity in conjunction with the inhibition of sympathetic tone in hypertensive patients.

METHODS

We evaluated plasma insulin levels, arterial baroreflex function and humoral parameters before and after exercise training. Twenty-nine patients with essential hypertension under hospitalization participated in the study. Before and after three weeks of exercise training (75% max VO2, 6 min, q.i.d.), 24-hour blood pressure recordings, arterial baroreflex function testing and 75 g glucose tolerance tests were conducted. Area under the curve of insulin (sigma insulin) to glucose load was calculated as an index of hyperinsulinemia.

RESULTS

Three weeks of exercise training decreased the 24-hour mean arterial pressure, heart rate and sigma insulin, and improved barorefiex function. There was a significant correlation between the reduction of arterial pressure and the change in sigma insulin. Furthermore, the reduction of sigma insulin was correlated with the improvement of baroreflex function and with the decrease in heart rate.

CONCLUSIONS

Exercise training lowered the arterial pressure, with parallel changes in heart rate, baroreflex function and insulin resistance. The correction of sympathetic overactivity was closely associated with the amelioration of hyperinsulinemia. Our results suggest that the improvement of neuro-metabolic factors may be involved in the depressor effect caused by exercise training.

MRI of gynaecological solid masses

Differential diagnosis of gynaecological masses is sometimes difficult, as there are so many histological types. However, magnetic resonance characteristics of some gynaecological tumours have been reported past several years. On the basis of the recent literature, we have made a decision tree for differential diagnosis of solid gynaecological tumours, in which there are some important divergences. Bilateral disease and invasive growth are malignant signs in most cases. Specific findings for different tumour types include: fibrovascular septa in dysgerminomas; preserving ovarian follicles in round cell tumours; pseudolobular patterns in young patients in sclerosing stromal tumours; and extremely hypointense masses on T2WI in Brenner tumours. Distinguishing between sex-cord stromal tumours, Brenner tumours and metastatic tumours may be hard, however, especially in middle age, because they all tend to show well-demarcated, hypointense masses on T2WI. Disproportionately clear zonal anatomy of the uterus, enlarged uterus and thickened endometrium, which are indirect findings of oestrogen-producing tumours, are useful diagnostic findings in children and postmenopausals.

Medicinal foodstuffs. XIX. Absolute stereostructures of canavalioside, a new Ent-kaurane-type diterpene glycoside, and gladiatosides A1, A2, A3, B1, B2, B3, C1, and C2, new acylated flavonol glycosides, from sword bean, the seeds of Canavalia gladiata

A new ent-kaurane-type glycoside, canavalioside, and eight new acylated flavonol glycosides, gladiatosides A1, A2, A3, B1, B2, B3, C1, and C2, were isolated from the seed of Canavalia gladiata together with robinin, kaempferol 3-O-beta-D-galactopyranosyl-7-O-alpha-L-rhamnopyranoside, and kaikasaponin III. The absolute stereostructures of canavalioside and gladiatosides A1, A2, B1, B2, B3, C1, and C2 were elucidated on the basis of chemical and physicochemical evidence.

Pharmacokinetics of a parenteral carbapenem, biapenem, in patients with end-stage renal disease and influence of haemodialysis

The effects of haemodialysis on the pharmacokinetics of a carbapenem, biapenem, were evaluated in five patients with end-stage renal disease, who received 1 h iv infusions of 300 mg biapenem on both the days on and off 4 h haemodialysis. With haemodialysis, plasma biapenem exhibited two elimination phases, one during and the other after haemodialysis with half-lives of 1.16 +/- 0.12 and 3.33 +/- 0. 91 h, respectively. Ninety percent of biapenem was removed from blood to dialysate. Without haemodialysis, plasma biapenem was mono-exponentially eliminated with a half-life of 4.35 +/- 1.30 h.

Tryptanthrin inhibits nitric oxide and prostaglandin E(2) synthesis by murine macrophages

Nitric oxide (NO) and prostaglandins have been implicated in the pathogenesis of several inflammatory diseases. In this study, we investigated the effect of tryptanthrin (6,12-dihydro-6, 12-dioxoindolo-(2,1-b)-quinazoline), an antimicrobial and antitumoral plant compound isolated from Porigonum tinctorium, on NO and prostaglandin E(2) production by interferon-gamma and lipopolysaccharide-stimulated murine macrophage-like RAW 264.7 cells. Tryptanthrin markedly inhibited both NO and prostaglandin E(2) production in a dose-dependent manner. Tryptanthrin at 20 microM fully inhibited expression of inducible NO synthase, suggesting that the inhibitory effect on NO synthesis was mediated by inhibited expression of the enzyme. On the other hand, tryptanthrin had no effect on the levels of cyclooxygenase-2 protein, but inhibited cyclooxygenase enzyme activity with a ICM(50) value of 1.5 microM. Thus, tryptanthrin has the dual functions of inhibiting both NO and prostaglandin E(2) production by activated macrophages, suggesting that tryptanthrin exhibits anti-inflammatory properties.

Proliferative response of peripheral blood mononuclear cells and levels of antibody to recombinant protein from Propionibacterium acnes DNA expression library in Japanese patients with sarcoidosis

BACKGROUND AND AIM OF THE WORK

The causes of sarcoidosis are unknown. Propionibacterium acnes has been isolated from sarcoid lesions, and many genomes of P. acnes or P. granulosum have been detected in all biopsy samples tested from Japanese patients with sarcoidosis. We searched for protein antigens from propionibacteria that caused immune responses in patients with sarcoidosis but not in subjects without sarcoidosis.

METHODS

A lambda gt11 genomic DNA expression library of P. acnes was screened with sera from patients with sarcoidosis. Antibodies to a recombinant protein from the insert recovered by the screening were measured in serum and bronchoalveolar lavage (BAL) fluid from patients with or without sarcoidosis by an immunofluorescence-based method. Peripheral blood mononuclear cells from patients with and without sarcoidosis were used to examine the lymphoproliferative response to the protein.

RESULTS

Of 180,000 plaques screened, two clones coded for an identical recombinant protein, termed RP35, were recognized by sera. RP35 was the C-terminal region of P. acnes trigger factor. RP35 caused sarcoidosis specific proliferation of the mononuclear cells from 9 (18%) of the 50 patients with sarcoidosis; in a similar way, purified protein derived from Mycobacterium tuberculosis evoked specific responses in 8 (38%) of 21 patients with tuberculosis. Serum levels of IgG and IgA antibodies to RP35 were high in patients with sarcoidosis and other lung diseases. In BAL fluid levels IgG or IgA antibodies were high in 7 (18%) and 15 (39%), respectively, of 38 patients with sarcoidosis, and in 2 (3%) and 2 (3%), respectively, of 63 patients with other lung diseases.

CONCLUSIONS

The RP35 protein from P. acnes causes a cellular immune response in some patients with sarcoidosis but not in subjects without sarcoidosis.

Structure and functional analysis of the human STAT3 gene promoter: alteration of chromatin structure as a possible mechanism for the upregulation in cisplatin-resistant cells

STAT3 is involved in the signal transduction activated by various cytokines and growth factors. We found that the STAT3 gene is overexpressed in cisplatin-resistant cells. We isolated a genomic fragment containing the 5'-portion of the human STAT3 gene using a bubble PCR method. Using the bubble PCR product as a probe, one genomic clone was isolated. The nucleotide sequence of the first exon and the 1800 base pairs (bps) preceding it was determined. The promoter region of the human STAT3 gene is highly homologous to the corresponding region of the mouse STAT3 gene; several potential factor binding sites such as CRE/ATF, SBE, and GC boxes are also well conserved between human and mouse. A transient expression assay using the luciferase reporter gene showed that the sequence from -403 to +102 possesses maximal promoter activity, and transcription of the STAT3 gene was significantly higher in cisplatin-resistant cells than in parental cisplatin-sensitive cells. Deletion of the region between -261 and -167 resulted in significant loss of promoter activity in both parental and cisplatin-resistant cells. In vivo footprint analysis revealed several protein bindings; however, no significant differences were observed between drug-sensitive and drug-resistant cells. MNase digestion revealed that several open or active nucleosomes were only detected in cisplatin-resistant cells. These results suggest that STAT3 promoter function in a highly structured chromatin environment requires a complex interaction of several transcriptional factors.

Polygonum tinctorium extract suppresses nitric oxide production by activated macrophages through inhibiting inducible nitric oxide synthase expression

Despite its beneficial role in host defense mechanisms, excessive nitric oxide (NO) production by activated macrophages has been implicated in several inflammatory diseases. To clarify the mechanisms of anti-inflammatory activities of Polygonum tinctorium, we evaluated whether extracts of P. tinctorium could modulate the production of NO by activated macrophages. An AcOEt extract of P. tinctorium markedly inhibited NO synthesis by interferon-gamma (IFN-gamma)/lipopolysaccharide (LPS)-stimulated murine peritoneal macrophages and the macrophage-like cell line RAW 264.7 in a dose-dependent manner. Inhibition of NO synthesis was achieved by reducing inducible NO synthase (iNOS) expression at protein and mRNA levels. However, the AcOEt extract of P. tinctorium failed to inhibit NO synthesis when iNOS was already expressed following stimulation with IFN-gamma and LPS. The AcOEt extract also exhibited inhibitory activity on iNOS expression in human lung epithelial A549 cells stimulated with a combination of IFN-gamma, TNF-alpha and IL-1 beta without affecting the expression of constitutive isoforms of NOS. Furthermore, in vivo injection of the AcOEt extract of P. tinctorium into LPS-treated mice significantly reduced NO synthesis by peritoneal exudate cells under ex vivo conditions. These results suggest that P. tinctorium extract may be a potential therapeutic modulator of NO synthesis in various pathological conditions.