Isolation and characterization of simian immunodeficiency virus from mandrills in Africa and its relationship to other human and simian immunodeficiency viruses

Two isolates of simian retrovirus related to the human immunodeficiency virus (HIV) were obtained from apparently healthy mandrills, Papio (Mandrillus) sphinx, in western equatorial Africa. This virus, designated SIVMND (simian immunodeficiency virus from mandrills), appeared morphologically similar to HIV by electron microscopy, showed Mg2+-dependent reverse transcriptase activity, and induced cytopathic effect in human CD4-positive cells. Western blotting (immunoblotting) analyses revealed that the gag and pol products of SIVMND showed cross-reactivity with those of known HIVs and SIVs. Molecular clones covering full-length viral DNA were obtained from closed circular extrachromosomal DNA of SIVMND-infected cells. By clone-on-clone hybridization with known retroviruses of the HIV and SIV groups, SIVMND showed similar cross-hybridization with HIV-1, HIV-2, SIVAGM (African green monkey-derived SIV), and SIVMAC (rhesus macaque-derived SIV) in the gag and pol regions only at low stringency but not at high stringency, a result indicating that SIVMND is a new member of the HIV-SIV group. The existence of distinct SIVs in different monkey species suggest that recent interspecies transfer of HIV-SIV is unlikely in nature.

Zinc is an essential trace element for spermatogenesis

Zinc (Zn) plays important roles in various biological activities but there is little available information regarding its functions in spermatogenesis. In our current study, we further examined the role of Zn during spermatogenesis in the Japanese eel (Anguilla japonica). Human CG (hCG) was injected into the animals to induce spermatogenesis, after which the concentration of Zn in the testis increased in tandem with the progression of spermatogenesis. Staining of testicular cells with a Zn-specific fluorescent probe revealed that Zn accumulates in germ cells, particularly in the mitochondria of spermatogonia and spermatozoa. Using an in vitro testicular organ culture system for the Japanese eel, production of a Zn deficiency by chelation with N,N,N',N'-tetrakis (2-pyridylemethyl)ethylenediamine (TPEN) caused apoptosis of the germ cells. However, this cell death was rescued by the addition of Zn to the cultures. Furthermore, an induced deficiency of Zn by TPEN chelation was found to inhibit the germ cell proliferation induced by 11-ketotestosterone (KT), a fish specific androgen, 17alpha,20beta-dihydroxy-4-pregnen-3-one (DHP), the initiator of meiosis in fish, and estradiol-17beta (E2), an inducer of spermatogonial stem-cell renewal. We also investigated the effects of Zn deficiency on sperm motility and observed that TPEN treatment of eel sperm suppressed the rate and duration of their motility but that co-treatment with Zn blocked the effects of TPEN. Our present results thus suggest that Zn is an essential trace element for the maintenance of germ cells, the progression spermatogenesis, and the regulation of sperm motility.

Follicle-stimulating hormone induces spermatogenesis mediated by androgen production in Japanese eel, Anguilla japonica

Follicle-stimulating hormone (FSH) plays important roles in spermatogenesis. However, the biologic activity of FSH can vary in different vertebrate classes, and the definitive function of FSH has not been established. In this study, we investigated the functions of FSH on spermatogenesis using an in vitro culture system for Japanese eel testis. The eel Fsh receptor was expressed in testis tissue during the whole process of spermatogenesis, mainly by Leydig cells that produce steroid hormones and by Sertoli cells surrounding type A spermatogonia and early type B spermatogonia. In an in vitro organ culture, recombinant eel Fsh (r-eFsh) induced complete spermatogenesis from the proliferation of spermatogonia to spermiogenesis during 36 days of culture; also, spermatozoa were observed in the testicular fragments. Spermatogenesis induced by r-eFsh was inhibited by trilostane, a specific inhibitor of 3beta-hydroxysteroid dehydrogenase. However, trilostane did not inhibit spermatogenesis induced by 11-ketotestosterone. These results clearly show that the main function of FSH in eel is to induce spermatogenesis via stimulating androgen production.

Phylogenetic subtypes of human T-lymphotropic virus type I and their relations to the anthropological background

Isolates of human T-lymphotropic virus type I (HTLV-I) were phylogenetically analyzed from native inhabitants in India and South America (Colombia and Chile) and from Ainu (regarded as pure Japanese descendants from the preagricultural "Jomon" period). Their genomes were partially sequenced together with isolates from Gabon in central Africa and from Ghana in West Africa. The phylogenetic tree was constructed from the sequence data obtained and those of previously reported HTLV-I isolates and simian T-lymphotropic virus type I (STLV-I) isolates. The heterogeneity of HTLV-I was recently recognized, and one major type, generally called the "cosmopolitan" type, contained Japanese, Caribbean, and West African isolates. The phylogenetic tree constructed in the present study has shown that this cosmopolitan type can be further grouped into three lineages (subtypes A, B, and C). Subtype A consists of some Caribbean, two South American, and some Japanese isolates, including that from the Ainu, in addition to an Indian isolate, and subtype B consists of other Japanese isolates in addition to another Indian isolate, suggesting that there might be at least two ancestral lineages of the Japanese HTLV-I. Subtype A implies a close connection of the Caribbean and South American natives with the Japanese and thereby a possible migration of the lineage to the American continent via Beringia in the Paleolithic era. Subtype C consists of the West African and other Caribbean isolates, indicating that not all but part of the Caribbean strains directly originated from West Africa probably during the period of slave trade. The tree also has shown that the HTLV-I isolate from Gabon in central Africa forms a cluster with STLV-I from a chimpanzee, suggesting a possible interspecies transmission between man and the chimpanzee in the past. No specific clustering was observed in the tree in relation to manifestations of the disease such as adult T-cell leukemia and HTLV-I-related neurological disorders. Thus, the topology of the phylogenetic tree reflects the movement of people carrying the virus in the past.

Involvement of sex steroid hormones in the early stages of spermatogenesis in Japanese huchen (Hucho perryi )

In higher vertebrates, considerable progress has been made in understanding the endocrine regulation of puberty; however, in teleosts, the regulatory mechanisms of spermatogenesis during the first annual cycle remain unclear. The present study was conducted to understand the regulatory mechanisms of spermatogenesis throughout the different stages of the first spermatogenic cycle and to check the ability of various steroids and hormones to induce in vitro spermatogonial proliferation in Japanese huchen (Hucho perryi ). The results indicate that the serum level of 11-ketotestosterone (11-KT) was positively associated with germ cell type; the level first began to rise with the appearance of late-type B spermatogonia and continued to increase gradually throughout the active spermatogenic stages and spermiogenesis, reaching a peak value 2 wk before spawning, and then declined. During the spermatogenic stages, the serum concentration of 17alpha,20beta-dihydroxy-4-pregnen-3-one (17alpha,20beta-DP) was undetectable. Only a small peak was detected with the appearance of spermatocytes and spermatids, and at the time of spawning, the level increased dramatically, reaching its maximum value with the onset of milt production. Despite the high variation in serum levels of 17beta-estradiol (E2) both between months and among the individuals, E2 was found during the whole reproductive cycle. From these results, we concluded that 1) 11-KT is necessary for the initiation of spermatogenesis and sperm production, and it probably plays a role in spermiation, 2) 17alpha,20beta-DP is essential for the final maturation stage, could play a significant role in the mitosis phase and meiosis process, and probably participates in the regulation of spawning behavior, and 3) estrogen is an indispensable male hormone that plays a physiological role in some aspects of testicular functions, especially during the mitotic phase. The three steroids were also able to induce DNA synthesis, spermatogonial renewal, and/or spermatogonial proliferation in vitro.

Higher hematocrit improves cerebral outcome after deep hypothermic circulatory arrest

BACKGROUND

Various degrees of hemodilution are currently in clinical use during deep hypothermic circulatory arrest to counteract deleterious rheologic effects linked with brain injury by previous reports.

MATERIAL AND METHODS

Seventeen piglets were randomly assigned to three groups. Group I piglets (n = 7) received colloid and crystalloid prime (hematocrit < 10%), group II piglets (n = 5) received blood and crystalloid prime (hematocrit 20%), group III piglets (n = 5) received blood prime (hematocrit 30%). All groups underwent 60 minutes of deep hypothermic circulatory arrest at 15 degrees C with continuous magnetic resonance spectroscopy and near-infrared spectroscopy Neurologic recovery was evaluated for 4 days (neurologic deficit score 0, normal, to 500, brain death; overall performance category 1, normal, to 5, brain death). Neurohistologic score (0, normal, to 5+, necrosis) was assessed after the animals were euthanized on day 4.

RESULTS

Group I had significant loss of phosphocreatine and intracellular acidosis during early cooling (phosphocreatine in group I, 86.3% +/- 26.8%; group II, 117.3% +/- 8.6%; group III, 110.9% +/- 2.68%; p = 0.0008; intracellular pH in group I, 6.95 +/- 0.18; group II, 7.28 +/- 0.04; group III, 7.49 +/- 0.04; p = 0.0048). Final recovery was the same for all groups. Cytochrome aa3 was more reduced in group I during deep hypothermic circulatory arrest than in either of the other groups (group I, -43.6 +/- 2.6; group II, -16.0 +/- 5.2; group III, 1.3 +/= 3.1; p < 0.0001). Neurologic deficit score was best preserved in group III (p < 0.05 group II vs group III) on the first postoperative day, although this difference diminished with time and all animals were neurologically normal after 4 days. Histologic assessment was worst among group I in neocortex area (group I, 1.33 +/- 0.3; group II, 0.22 +/- 0.1; group III, 0.40 +/- 0.2, p < 0.05, group I vs group II; p = 0.0287, group I vs group III).

CONCLUSION

Extreme hemodilution during cardiopulmonary bypass may cause inadequate oxygen delivery during early cooling. The higher hematocrit with a blood prime is associated with improved cerebral recovery after deep hypothermic circulatory arrest.

Electrolyzed-reduced water scavenges active oxygen species and protects DNA from oxidative damage

Active oxygen species or free radicals are considered to cause extensive oxidative damage to biological macromolecules, which brings about a variety of diseases as well as aging. The ideal scavenger for active oxygen should be 'active hydrogen'. 'Active hydrogen' can be produced in reduced water near the cathode during electrolysis of water. Reduced water exhibits high pH, low dissolved oxygen (DO), extremely high dissolved molecular hydrogen (DH), and extremely negative redox potential (RP) values. Strongly electrolyzed-reduced water, as well as ascorbic acid, (+)-catechin and tannic acid, completely scavenged O.-2 produced by the hypoxanthine-xanthine oxidase (HX-XOD) system in sodium phosphate buffer (pH 7.0). The superoxide dismutase (SOD)-like activity of reduced water is stable at 4 degrees C for over a month and was not lost even after neutralization, repeated freezing and melting, deflation with sonication, vigorous mixing, boiling, repeated filtration, or closed autoclaving, but was lost by opened autoclaving or by closed autoclaving in the presence of tungsten trioxide which efficiently adsorbs active atomic hydrogen. Water bubbled with hydrogen gas exhibited low DO, extremely high DH and extremely low RP values, as does reduced water, but it has no SOD-like activity. These results suggest that the SOD-like activity of reduced water is not due to the dissolved molecular hydrogen but due to the dissolved atomic hydrogen (active hydrogen). Although SOD accumulated H2O2 when added to the HX-XOD system, reduced water decreased the amount of H2O2 produced by XOD. Reduced water, as well as catalase and ascorbic acid, could directly scavenge H2O2. Reduce water suppresses single-strand breakage of DNA b active oxygen species produced by the Cu(II)-catalyzed oxidation of ascorbic acid in a dose-dependent manner, suggesting that reduced water can scavenge not only O2.- and H2O2, but also 1O2 and .OH.

Sequence of a novel simian immunodeficiency virus from a wild-caught African mandrill

Since the isolation of an HIV-2-related virus from captive macaques (SIVMAC), the origin of human immunodeficiency viruses, a much debated subject, has been attributed to monkeys. The sequence of SIVAGM, which is derived from a naturally infected African green monkey, shows equal relatedness to HIV-1 and HIV-2, suggesting that the derivation of these viruses from SIVAGM is unlikely. Recent sequence analysis of SIV from a captive sooty mangabey (SIVMAC), however, shows its close relatedness to HIV-2 and SIVMAC, indicating a possible origin of HIV-2 and SIVMAC from SIVSM (refs 4, 7, 9). We report here the sequence of a novel simian lentivirus, SIVMND, isolated from a wild-caught mandrill in Africa. It is distinct from the three other main groups, HIV-1, HIV-2/SIVMAC/SIVSM and SIVAGM, and therefore represents a fourth main group of primate lentiviruses. Phylogenetic analysis indicates that these four main virus groups might have diverged from a common ancestor at about the same time, long before the spread of AIDS in humans.

Metal-dependent alpha-helix formation promoted by the glycine-rich octapeptide region of prion protein

Prion diseases share a common feature in that the normal cellular prion protein (PrP(C)) converts to a protease-resistant isoform PrP(Sc). The alpha-helix-rich C-terminal half of PrP(C) is partly converted into beta-sheet in PrP(Sc). We have examined by Raman spectroscopy the structure of an octapeptide PHGGGWGQ that appears in the N-terminal region of PrP(C) and a longer peptide containing the octapeptide region. The peptides do not assume any regular structure without divalent metal ions, whereas Cu(II) binding to the HGGG segment induces formation of alpha-helical structure on the C-terminal side of the peptide chain. The N-terminal octapeptide of prion protein may be a novel structural motif that acts as a promoter of alpha-helix formation.

Bruton's tyrosine kinase regulates apoptosis and JNK/SAPK kinase activity

Mast cells derived from Bruton's tyrosine kinase (Btk)-defective xid or btk null mice showed greater expansion in culture containing interleukin-3 (IL-3) than those from wild-type (wt) mice. Although the proliferative response to IL-3 was not significantly different between the wt and xid mast cells, xid and btk null mast cells died by apoptosis more slowly than their wt counterparts upon IL-3 deprivation. Consistent with these findings, the apoptosis-linked c-Jun N-terminal kinase/stress-activated protein kinase (JNK) activity was compromised in these btk-mutated cells upon Fc(epsilon)RI crosslinking or upon stimulation with IL-3 or with stem cell factor. p38 activity was less severely, but significantly, affected by btk mutation, whereas extracellular signal-regulated kinases were not affected by the same mutation. Btk-mediated regulation of apoptosis and JNK activity was confirmed by reconstitution of btk null mutant mast cells with the wt btk cDNA. Furthermore, growth factor withdrawal induced the activation and sustained activity of JNK in wt mast cells, while JNK activity was consistently lower in btk-mutated mast cells. These results support the notion that Btk regulates apoptosis through the JNK activation.

Regulation by orexin of feeding behaviour and locomotor activity in the goldfish

Orexin is a hypothalamic neuropeptide that is implicated in the regulation of feeding behaviour and the sleep-wakefulness cycle in mammals. However, in spite of a growing body of knowledge concerning orexin in mammals, the orexin system and its function have not been well studied in lower vertebrates. In the present study, we first examined the effect of feeding status on the orexin-like immunoreactivity (orexin-LI) and the expression of orexin mRNA in the goldfish brain. The number of cells showing orexin-LI in the hypothalamus of goldfish brain showed a significant increase in fasted fish and a significant decrease in glucose-injected fish. The expression level of orexin mRNA in the brains of fasted fish increased compared to that of fed fish. We also examined the effect of an i.c.v. injection of orexin or an anti-orexin serum on food intake and locomotor activity in the goldfish. Administration of orexin by i.c.v. injection induced a significant increase of food intake and locomotor activity, whereas i.p. injection of glucose or i.c.v. injection of anti-orexin serum decreased food consumption. These results indicate that the orexin functions as an orexigenic factor in the goldfish brain.

A missense mutation in the cholesteryl ester transfer protein gene with possible dominant effects on plasma high density lipoproteins

Plasma HDL are a negative risk factor for atherosclerosis. Cholesteryl ester transfer protein (CETP; 476 amino acids) transfers cholesteryl ester from HDL to other lipoproteins. Subjects with homozygous CETP deficiency caused by a gene splicing defect have markedly elevated HDL; however, heterozygotes have only mild increases in HDL. We describe two probands with a CETP missense mutation (442 D:G). Although heterozygous, they have threefold increases in HDL concentration and markedly decreased plasma CETP mass and activity, suggesting that the mutation has dominant effects on CETP and HDL in vivo. Cellular expression of mutant cDNA results in secretion of only 30% of wild type CETP activity. Moreover, coexpression of wild type and mutant cDNAs leads to inhibition of wild type secretion and activity. The dominant effects of the CETP missense mutation during cellular expression probably explains why the probands have markedly increased HDL in the heterozygous state, and suggests that the active molecular species of CETP may be multimeric.

Effect of caspase inhibitors on myocardial infarct size and myocyte DNA fragmentation in the ischemia-reperfused rat heart

OBJECTIVE

Caspase family proteases are recognized as key mediators of apoptosis. However, the role of caspases in the ischemia-reperfused heart remains uncertain. We evaluated the effect of caspase inhibitors on myocardial infarct size and the myocyte DNA fragmentation in the ischemia-reperfused rat hearts.

METHODS

Three groups of Sprague-Dawley rats (n = 7, each) were subjected to 30 min of ischemia followed by 6 h of reperfusion. One of the following drugs: (1) YVAD-aldehyde, a caspase-1-like protease inhibitor (3.5 mg/kg; YVAD), (2) DEVD-aldehyde, a caspase-3-like protease inhibitor (3.5 mg/kg, DEVD), (3) vehicle (140 microliters/kg) was administered intravenously 5 min prior to the ischemia in each group. Myocardial infarct size was defined by triphenyltetrazolium chloride (TTC) staining. Immunohistochemical staining by in situ nick end labeling (TUNEL) of cardiomyocytes and DNA electrophoresis were used for detecting DNA fragmentation. Ultrastructural analysis was done by electron microscopy. The caspase activity was measured in the myocardium of both groups.

RESULTS

The percentage of TUNEL-positive myocyte nuclei (%AP) was quantified by microscopy. A ladder pattern was detected by electrophoresis of DNA from the risk area and TUNEL-positive myocytes were seen in the risk area. The %AP was significantly reduced from 20 +/- 1% to 12 +/- 3% by YVAD and to 10 +/- 3% by DEVD (both P < 0.01). However, caspase inhibitors did not significantly change the infarct size. Electronmicrograph showed similar salcolemmal and mitochondrial damage in both group. The caspase activity was blocked by DEVD at 4 h after reperfusion.

CONCLUSION

Myocyte DNA fragmentation and caspase activation was inhibited by caspase inhibitors without reduction of the infarct size in ischemia-reperfused rat hearts.

Direct observation of ferromagnetic spin polarization in gold nanoparticles

We report the first direct observation of ferromagnetic spin polarization of Au nanoparticles with a mean diameter of 1.9 nm using x-ray magnetic circular dichroism (XMCD). Owing to the element selectivity of XMCD, only the gold magnetization is explored. Magnetization of gold atoms as estimated by XMCD shows a good agreement with results obtained by conventional magnetometry. This evidences intrinsic spin polarization in nanosized gold.

Spermatogenesis-preventing substance in Japanese eel

Under fresh-water cultivation conditions, spermatogenesis in the Japanese eel is arrested at an immature stage before initiation of spermatogonial proliferation. A single injection of human chorionic gonadotropin can, however, induce complete spermatogenesis, which suggests that spermatogenesis-preventing substances may be present in eel testis. To determine whether such substances exist, we have applied a subtractive hybridisation method to identify genes whose expression is suppressed after human chorionic gonadotropin treatment in vivo. We found one previously unidentified cDNA clone that was downregulated by human chorionic gonadotropin, and named it ‘eel spermatogenesis related substances 21’ (eSRS21). A homology search showed that eSRS21 shares amino acid sequence similarity with mammalian and chicken Müllerian-inhibiting substance. eSRS21 was expressed in Sertoli cells of immature testes, but disappeared after human chorionic gonadotropin injection. Expression of eSRS21 mRNA was also suppressed in vitro by 11-ketotestosterone, a spermatogenesis-inducing steroid in eel. To examine the function of eSRS21 in spermatogenesis, recombinant eSRS21 produced by a CHO cell expression system was added to a testicular organ culture system. Spermtogonial proliferation induced by 11-ketotestosterone in vitro was suppressed by recombinant eSRS21. Furthermore, addition of a specific anti-eSRS21 antibody induced spermatogonial proliferation in a germ cell/somatic cell co-culture system. We conclude that eSRS21 prevents the initiation of spermatogenesis and, therefore, suppression of eSRS21 expression is necessary to initiate spermatogenesis. In other words, eSRS21 is a spermatogenesis-preventing substance.

New antidiabetic compounds, mangiferin and its glucoside

Mangiferin (MF) and its glucosides (mangiferin-7-O-beta-glucoside) (MG) isolated from Anemarrhena asphodeloides Bunge rhizome, were tested for their antidiabetic activity in KK-Ay mice, an animal model of non-insulin-dependent diabetes mellitus (NIDDM). MF and MG lowered the blood glucose level of KK-Ay mice after oral administration. However, no affect on the blood glucose level in normal mice was seen, indicating that MF and MG are useful in treating NIDDM. In addition, MF or MG improved hyperinsulinemia in KK-Ay mice. From these findings, it seems likely that MF and MG exert their its antidiabetic activity by increasing insulin sensitivity.

Progestin is an essential factor for the initiation of the meiosis in spermatogenetic cells of the eel

Meiosis is an indispensable process of sexual reproduction. However, detailed information on the regulatory mechanisms that initiate meiosis is not available. Progestins are important steroids regulating final maturation in male and female vertebrates. In male teleosts, it is known that progestin induces spermiation and sperm maturation. However, a role for progestin in early spermatogenesis or meiosis has not yet been described. In this study, we examined the functions of progestin on the initiation of meiosis in male Japanese eel. A natural progestin in teleost fish 17alpha,20beta-dihydroxy-4-pregnen-3-one (DHP) and its receptors were present in the testis at an early stage of spermatogenesis. By using an eel testicular culture system, DHP was shown to induce DNA replication in spermatogonia. Although 11-ketotestosterone, a known initiator of spermatogenesis, also stimulated DNA synthesis in spermatogonia, antibodies against DHP prevented DNA replication when added during the period in which meiosis was initiated. DHP treatment also induced the expression of meiosis-specific markers, such as DmcI and Spo11. Furthermore, Spo11 expression and synaptonemal complexes, specific features of the meiotic prophase, were detected in testicular fragments cultured with DHP in some germ cells that showed morphological characteristics of undifferentiated spermatogonia. We conclude that DHP, a progestin, is an essential factor for the initiation of meiosis.

Hypoglycemic activity of the fruit of the Momordica charantia in type 2 diabetic mice

The antidiabetic activity of Momordica charantia L. (Cucurbitaceae) was investigated in KK-Ay mice, an animal model with type 2 diabetes with hyperinsulinemia. The water extract of the fruit of Momordica charantia L. (MC) reduced the blood glucose of KK-Ay mice 3 weeks after oral administration (p<0.01) and also significantly lowered the serum insulin of KK-Ay mice under similar conditions (p<0.01). However, MC did not affect the blood glucose in normal mice. MC-treated KK-Ay mice blood glucose significantly decreased in an insulin tolerance test. Moreover, the muscle content of facilitative glucose transporter isoform 4 (GLUT4) protein content in the plasma membrane fraction from muscle significantly increased in the orally MC-treated mice when compared with that of the controls (p<0.01). These results suggest that the antidiabetic effect of MC is derived, at least in part, from a decrease in insulin resistance because of the increase of GLUT4 protein content in the plasma membrane of the muscle.

Mutational analysis of the human immunodeficiency virus type 2 (HIV-2) genome in relation to HIV-1 and simian immunodeficiency virus SIV (AGM)

We constructed an infectious molecular clone of the human immunodeficiency virus type 2 (HIV-2) and generated nine frameshift mutants corresponding to nine open reading frames identified so far. Three structural (gag, pol, env) and two regulative (tat, rev) gene mutants were not infectious, whereas vif, vpx, vpr, and nef genes were dispensable for infectivity. All of the mutants except env and rev were cytopathic in CD4+ human leukemia cells. In transfection assays, the expression of HIV-2 long terminal repeat was activated by infectious clones of HIV-1, HIV-2, and simian immunodeficiency virus from African green monkey but not by the tat mutants. However, an HIV-2 tat mutant could produce small amounts of virus proteins and particles in contrast to a rev mutant, which directed no detectable synthesis of virus proteins and virions.

Curcumin activates human glutathione S-transferase P1 expression through antioxidant response element

Curcumin is a plant-derived diferuloylmethane compound extracted from Curcuma longa, possessing antioxidative and anticarcinogenic properties. Antioxidants and oxidative stress are known to induce the expression of certain classes of detoxification enzymes. Since the upregulation of detoxifying enzymes affects the drug metabolism and cell defense system, it is important to understand the gene regulation by such agents. In this study, we demonstrated that curcumin could induce the expression of human glutathione S-transferase P1 (GSTP1). In HepG2 cells treated with 20muM curcumin, the level of GSTP1 mRNA was significantly increased. In luciferase reporter assays, curcumin augmented the promoter activity of a reporter construct carrying 336bp upstream of the 5'-flanking region of the GSTP1 gene. Mutation analyses revealed that the region including antioxidant response element (ARE), which overlaps AP1 in sequence, was essential to the response to curcumin. While the introduction of a wild-type Nrf2 expression construct augmented the promoter activity of the GSTP1 gene, co-expression of a dominant-negative Nrf2 abolished the responsiveness to curcumin. In addition, curcumin activated the expression of the luciferase gene from a reporter construct carrying multiple ARE consensus sequences but not one with multiple AP1 sites. In a gel mobility shift assay with an oligonucleotide with GSTP1 ARE, an increase in the amount of the binding complex was observed in the nuclear extracts of curcumin-treated HepG2 cells. These results suggested that ARE is the primary sequence for the curcumin-induced transactivation of the GSTP1 gene. The induction of GSTP1 may be one of the mechanisms underlying the multiple actions of curcumin.

Adrenergic control of the force-frequency relation

This article briefly reviews recent experimental studies which show that beta-adrenergic receptor stimulation produces an important enhancement of the force-frequency relation on myocardial contractility. The basic property of the force-frequency effect to progressively enhance myocardial contractility as heart rate increases is augmented at each level of increasing adrenergic stimulation. This newly described intrinsic mechanism for the control of cardiac inotropic state, graded beta-adrenergic amplification of the force-frequency relation, is strongly manifested during normal exercise and infusion of a beta-adrenergic agonist at rest, and it influences both systolic and diastolic ventricular function. Significant impairment of adrenergic amplification of the force-frequency relation is observed in experimental heart failure and could contribute to impaired cardiac function during stress or exercise in this setting.

TGFbeta2 acts as an "activator" molecule in reaction-diffusion model and is involved in cell sorting phenomenon in mouse limb micromass culture

It was previously speculated that TGFbeta acts as an "activator"-molecule in chondrogenic pattern formation in the limb micromass culture system, but its precise role and relationship with the cell sorting phenomenon have not been properly studied. In the present study, we examined whether the TGFbeta2 molecule satisfies the necessary conditions for an "activator"-molecule in the reaction-diffusion model. Firstly, we showed that TGFbeta2 became localized at chondrogenic sites during the establishment of a chondrogenic pattern, and exogenous TGFbeta2 promoted chondrogenesis when added in the culture medium. Secondly, TGFbeta2 protein was shown to promote the production of its own mRNA after 3 hr, indicating that a positive feedback mechanism exists which may be responsible for the emergence of the chondrogenic pattern. We then found that when locally applied with beads, TGFbeta2 suppressed chondrogenesis around the beads, indicating it induces the lateral inhibitory mechanism, which is a key element for the formation of the periodic pattern. We also examined the possible effects of TGFbeta2 on the cell sorting phenomenon and found that TGFbeta2 exerts differential chemotactic activity on proximal and distal mesenchyme cells of the limb bud, and at very early phases of differentiation TGFbeta2 promotes the expression of N-cadherin protein which is known to be involved in pattern formation in this culture system. These findings suggest that TGFbeta2 acts as an "activator"-like molecule in chondrogenic pattern formation in vitro, and is possibly responsible for the cell sorting phenomenon.

Glycosylation site binding protein and protein disulfide isomerase are identical and essential for cell viability in yeast

Glycosylation site binding protein (GSBP) has been shown to be identical to protein disulfide isomerase (PDI; EC 5.3.4.1) in a variety of multicellular organisms. We have utilized immunological and biochemical techniques to determine if GSBP and PDI are identical in yeast. Antiserum prepared against yeast GSBP identified in microsomes by its ability to be labeled with a peptide photoaffinity probe was found to recognize PDI purified from yeast. Moreover, this purified yeast PDI was found to be specifically labeled by the photoaffinity probe originally used to identify GSBP in a variety of eukaryotes. On the basis of these observations, we conclude that yeast GSBP and PDI are the same protein. The structure of the yeast PDI gene revealed a product with sequence similarity to higher eukaryotic PDI/GSBP. Disruption of this gene in yeast resulted in a recessive lethal mutation, indicating that PDI/GSBP is required for cell viability.

Functional modulation of the glucocorticoid receptor and suppression of NF-kappaB-dependent transcription by ursodeoxycholic acid

Ursodeoxycholic acid (UDCA) is the current mainstay of treatment for various liver diseases including primary biliary cirrhosis. UDCA acts as a bile secretagogue, cytoprotective agent, immunomodulator, and inhibitor of cellular apoptosis. Despite this cumulative evidence of the cytoprotective and immunosuppressive effects of UDCA, both the target molecule and pathway of UDCA action remain unknown. We previously described that, in the absence of glucocorticoid ligand, UDCA activates the glucocorticoid receptor (GR) into DNA binding species but does not elicit its transactivational function in a transient transfection assay. Here we further studied the molecular mechanism of UDCA action and revealed that the ligand binding domain of the GR is responsible for UDCA-dependent nuclear translocation of the GR. Indeed, we demonstrated that UDCA acts on the distinct region of the ligand binding domain when compared with the classical GR agonist dexamethasone, resulting in loss of coactivator recruitment and differential regulation of gene expression by the GR. Our data clearly indicated that UDCA, at least in part via activation of the GR, suppresses NF-kappaB-dependent transcription through the intervention of GR-p65 interaction. Together with the established clinical safety of UDCA, we may propose that UDCA could be a prototypical compound for development of a novel and selective GR modifier.

The influence of age and sex on ulnar variance

Ulnar variance was measured in 325 normal wrists and 41 wrists with Kienböck's disease. A positive correlation between ulnar variance and age was confirmed in normal wrists, and it was lower in males than in females. Therefore, studies comparing ulnar variance in abnormal and normal wrists require carefully selected age- and sex-matched controls. There was no significant difference in ulnar variance between Japanese with normal wrists and those affected by Kienböck's disease, when the effects of sex and age were taken into account. Based on these results, we believe that ulnar variance is highly unlikely to be an important predisposing factor in Kienböck's disease.