Design and synthesis of tricyclic tetrahydroquinolines as a new series of nonsteroidal selective androgen receptor modulators (SARMs)

Some tricyclic tetrahydroquinolines (THQs) were found to have the potential of a new series of nonsteroidal selective androgen receptor modulators (SARMs). Compound 5b was first designed and synthesized under our hypothesis based on a four-point pharmacophoric requirement of the 3-carbonyl, 18-methyl, 17-hydroxyl, and 13-quaternary carbon groups of dihydrotestosterone (DHT). It was revealed that this compound exhibits not only a strong androgen receptor (AR) agonistic activity (EC₅₀ = 9.2 nM) but also the highest selectivity in binding affinity to AR among the steroid hormone receptors. Furthermore, this compound showed a weak virilizing effect with retention of the desired anabolic effect as compared with DHT in vivo.     

Tetrahydroquinolines as a novel series of nonsteroidal selective androgen receptor modulators: structural requirements for better physicochemical and biological properties

A rationally designed tetrahydroquinoline (1) for nonsteroidal selective androgen receptor modulators was modified for the exploration of promising compounds by Grieco three-component condensation using various dienophiles. Based on the in vitro effects and physicochemical properties of the synthesized compounds, compound 4c was selected for further study. Compound 4c increased the femoral bone mineral density as much as DHT, but it reduced the uterus effect compared with DHT in ovariectomized rats. Thus, compound 4c has desirable osteoanabolic effects with weak undesirable effects on the uterus in a female osteoporosis model.     

Gamma-irradiated influenza virus uniquely induces IFN-I mediated lymphocyte activation independent of the TLR7/MyD88 pathway

Background

We have shown previously in mice, that infection with live viruses, including influenza/A and Semliki Forest virus (SFV), induces systemic partial activation of lymphocytes, characterized by cell surface expression of CD69 and CD86, but not CD25. This partial lymphocytes activation is mediated by type-I interferons (IFN-I). Importantly, we have shown that γ-irradiated SFV does not induce IFN-I and the associated lymphocyte activation.

Principal Findings

Here we report that, in contrast to SFV, γ-irradiated influenza A virus elicits partial lymphocyte activation in vivo. Furthermore, we show that when using influenza viruses inactivated by a variety of methods (UV, ionising radiation and formalin treatment), as well as commercially available influenza vaccines, only γ-irradiated influenza virus is able to trigger IFN-I-dependent partial lymphocyte activation in the absence of the TLR7/MyD88 signalling pathways.

Conclusions

Our data suggest an important mechanism for the recognition of γ-irradiated influenza vaccine by cytosolic receptors, which correspond with the ability of γ-irradiated influenza virus to induce cross-reactive and cross-protective cytotoxic T cell responses.     

Molecular properties of rod and cone visual pigments from purified chicken cone pigments to mouse rhodopsin in situ.

We have investigated the molecular properties of rod and cone visual pigments to elucidate the differences in the molecular mechanism(s) of the photoresponses between rod and cone photoreceptor cells. We have found that the cone pigments exhibit a faster pigment regeneration and faster decay of meta-II and meta-III intermediates than the rod pigment, rhodopsin. Mutagenesis experiments have revealed that the amino acid residues at positions 122 and 189 in the opsins are the determinants for these differences. In order to study the relationship between the molecular properties of visual pigments and the physiology of rod photoreceptors, we used mouse rhodopsin as a model pigment because, by gene-targeting, the spectral properties of the pigment can be directly correlated to the physiology of the cells. In the present paper, we summarize the spectroscopic properties of cone pigments and describe our studies with mouse rhodopsin utilizing a high performance charge coupled device (CCD) spectrophotometer.     

Dual functions of the steroid hormone receptor coactivator 3 in modulating resistance to thyroid hormone

Mutations of the thyroid hormone receptor beta (TRbeta) gene cause resistance to thyroid hormone (RTH). RTH is characterized by increased serum thyroid hormone associated with nonsuppressible thyroid-stimulating hormone (TSH) and impaired growth. It is unclear how the actions of TRbeta mutants are modulated in vivo to affect the manifestation of RTH. Using a mouse model of RTH that harbors a knockin mutation of the TRbeta gene (TRbetaPV mouse), we investigated the effect of the steroid hormone receptor coactivator 3 (SRC-3) on RTH. In TRbetaPV mice deficient in SRC-3, dysfunction of the pituitary-thyroid axis and hypercholesterolemia was lessened, but growth impairment of RTH was worsened. The lessened dysfunction of the pituitary-thyroid axis was attributed to a significant decrease in growth of the thyroid and pituitary. Serum insulin-like growth factor 1 (IGF-1) was further reduced in TRbetaPV mice deficient in SRC-3. This effect led to reduced signaling of the IGF-1/phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway that is known to mediate cell growth and proliferation. Thus, SRC-3 modulates RTH by at least two mechanisms, one via its role as a receptor coregulator and the other via its growth regulatory role through the IGF-1/PI3K/AKT/mTOR signaling.     

Tumor-derived interleukin (IL)-6 induced anti-tumor effect in immune-compromised hosts

Tumor-derived cytokines, such as interleukin (IL)-6, function in the context of tumor-to-host interactions, and their functions in immune-compromised hosts need to be addressed in the light of ever- increasing number of patients under immunosuppression. We studied the effects, in immune-comprised animals, of tumor-derived IL-6 on tumor growth using an experimental tumor vaccination model. Murine mammary carcinoma FM3A clone 25 (CL25) cells, which neither produce IL-6 nor express IL-6 receptors, were used. cDNA for murine IL-6 (mIL-6) was introduced to the CL25 cells, resulting in a high-producer (mIL-6H) clone. In the severe combined immune-deficient (SCID) mice, the inoculation 3 weeks earlier of mIL-6H to a dorsal flank site suppressed the growth of the CL25 cells at the opposite flank site; a tumor-derived IL-6-mediated vaccination effect occurred. In the T-cell-deficient nude mice, the inoculations 4 weeks earlier of mIL-6H suppressed the growth of CL25, but the simultaneous inoculation of these transfectants did not affect the growth of CL25. Reducing the number of inoculated transfectants or a shorter vaccination period obscured the suppressive effect. The amounts of circulating tumor-reactive immunoglobulin did not correlate with the suppressive effect. The subcutaneous injection of the anti-CD40 antibody generated a further suppression of tumor growth in the mIL-6H-inoculated, but not in the mock-inoculated, T-cell-deficient mice. In the immune-competent hosts, a suppressive effect was not observed. Natural killer (NK) activity was augmented in the spleen of mIL-6H-inoculated scid mice. This study indicated a possible vaccination effect with tumor-derived IL-6 in immune-compromised hosts.     

Multi-gene gateway clone design for expression of multiple heterologous genes in living cells: conditional gene expression at near physiological levels

Using Multisite Gateway five-DNA-fragment constructs vectors that enable expression of two tandemly situated cDNAs on a single plasmid were developed. Heterologous protein production in cells was achieved by modulating respective cDNA expression to pre-determined and different levels. Optimization of cDNA expression at near physiological protein levels was achieved using promoters from four cell cycle-dependent genes. In comparison with conventionally available promoters, EF-1alpha or CMV, the promoters used in this study were able to modulate cDNA expression levels over a magnitude of approximately 10 or 100-fold, respectively. In transiently transfected cells, two different proteins (CPalpha1 and CPbeta2), which form a heterodimer, each labeled with a different-colored fluorescent protein, were successfully synthesized at pre-determined levels from their respective cDNAs. The above vectors were designed to contain an FRT/Flp recombination site for integration onto chromosomes and for establishment of stable clones in HeLa cells by site-specific recombination. In the stable transformant cells produced only about 4% of the protein production levels measured in the transiently transformed cells. The biological significance of these observations is discussed.     

Low ethanol consumption induces enhancement of insulin sensitivity in liver of normal rats

Moderate amounts of alcohol intake have been reported to have a protective effect on the cardiovascular system and this may involve enhanced insulin sensitivity. We established an animal model of increased insulin sensitivity by low ethanol consumption and here we investigated metabolic parameters and molecular mechanisms potentially involved in this phenomenon. For that, Wistar rats have received drinking water either without (control) or with 3% ethanol for four weeks. The effect of ethanol intake on insulin sensitivity was analyzed by insulin resistance index (HOMA-IR), intravenous insulin tolerance test (IVITT) and lipid profile. The role of liver was investigated by the analysis of insulin signaling pathway, GLUT2 gene expression and tissue glycogen content. Rats consuming 3% ethanol showed lower values of HOMA-IR and plasma free fatty acids (FFA) levels and higher hepatic glycogen content and glucose disappearance constant during the IVITT. Neither the phosphorylation of insulin receptor (IR) and insulin receptor substrate-1 (IRS-1), nor its association with phosphatidylinositol-3-kinase (PI3-kinase), was affected by ethanol. However, ethanol consumption enhanced liver IRS-2 and protein kinase B (Akt) phosphorylation (3 times, P<0.05), which can be involved in the 2-fold increased (P<0.05) hepatic glycogen content. The GLUT2 protein content was unchanged. Our findings point out that liver plays a role in enhanced insulin sensitivity induced by low ethanol consumption.