Reinvestigation of the virulence of Rhodococcus equi isolates from patients with and without AIDS.

Rhodococcus equi emerged as a zoonotic pathogen of human immunodeficiency virus-infected patients over the last three decades. Two virulence plasmid types of R. equi, pVAPA and pVAPB associated with equine and porcine isolates, have been recognized, and more recently, pVAPN, a novel host-associated virulence plasmid in R. equi, was found in bovine and caprine isolates. We reinvestigated 39 previously reported isolates of R. equi from patients with and without acquired immunodeficiency syndrome (AIDS) by detecting vapA, vapB and vapN using PCR and plasmid profiling. After excluding one isolate that could not be cultured from frozen storage, eight isolates carried a virulence plasmid encoding vapA (pVAPA), 10 carried a virulence plasmid encoding vapB (pVAPB), seven carried a virulence plasmid encoding vapN (pVAPN) and 13 were negative for those genes. Of the 29 isolates from patients with AIDS, 7, 10 and 5 harboured pVAPA, pVAPB and pVAPN respectively. Among nine isolates from patients without AIDS, one and two harboured pVAPA and pVAPN respectively. This study demonstrated that pVAPN-positive R. equi existed in human isolates before 1994 and reaffirmed that equine-associated pVAPA-positive, porcine-associated pVAPB-positive and bovine- or caprine-associated pVAPN-positive R. equi are widely spread globally. Because domestic animals might be major sources of human infection, further research is needed to reveal the prevalence of pVAPN-positive R. equi infection in cattle and goats.

Skin cancer prevention: a possible role of 1,25dihydroxyvitamin D3 and its analogs.

We previously reported that the natural hormone 1,25dihydroxyvitamin D3 (1,25(OH)(2)D(3)) protects human skin cells from ultraviolet radiation (UVR)-induced apoptosis. UVR-induced pre-mutagenic cyclobutane pyrimidine dimers are diminished in number from 0.5h after cessation of UVR in all skin cell types, by treatment with three different Vitamin D compounds: by 1,25(OH)(2)D(3), by the rapid acting, low calcemic analog, 1alpha,25(OH)(2)lumisterol(3) (JN) and by the low calcemic but transcriptionally active hybrid analog 1alpha-hydroxymethyl-16-ene-24,24-difluoro-25-hydroxy-26,27-bis-homovitamin D3 QW-1624F2-2 (QW), which may explain the enhanced cell survival. The rapid response antagonist analog 1beta,25(OH)(2)D(3) (HL) abolished the photoprotective effects of 1,25(OH)(2)D(3) whilst a genomic antagonist, (23S)-25-dehydro-1alpha-hydroxyvitamin D(3)-26,23-lactone (TEI-9647), had no effect. UVR increased p53 expression in human skin cells, whilst concurrent treatment with 1,25(OH)(2)D(3) further enhanced this effect several fold, at 3 and 6h after UVR. Combined with previously reported lower nitrite levels with 1,25(OH)(2)D(3), this increased p53 expression may favor DNA repair over apoptosis. We now report that topical application of 1,25(OH)(2)D(3) or QW also suppressed solar simulated UV (SSUVR-induced pyrimidine dimers in the epidermis of irradiated hairless Skh:HR1 mice, measured 24h after irradiation. Furthermore, UVR-induced immunosuppression in the mice was markedly reduced by topical application of either 1,25(OH)(2)D(3) or QW. These preliminary results show, for the first time, a protective effect of Vitamin D compounds against DNA photodamage in vivo.

Depressive mood is independently related to stroke and cardiovascular events in a community.

By means of a multivariate Cox model, we investigated the predictive value of a depressive mood on vascular disease risk in middle-aged community-dwelling people. In 224 people (88 men and 136 women; mean age: 56.8 +/- 11.2 years) of U town, Hokkaido (latitude: 43.45 degrees N, longitude: 141.85 degrees E), a chronoecological health watch was started in April 2001. Consultations were repeated every 3 months. Results at the November 30, 2004 follow-up are presented herein. 7-day/24-h blood pressure (BP) and heart rate (HR) monitoring started on a Thursday, with readings taken at 30-min intervals between 07:00 h and 22:00 h and at 60-min intervals between 22:00 h and 07:00 h. Data stored in the memory of the monitor (TM-2430-15, A and D company, Japan) were retrieved and analyzed on a personal computer with a commercial software for this device. Subjects were asked to answer a self-administered questionnaire inquiring about 15 items of a depression scale, at the start of study and again after 1-2 years. Subjects with a score higher by at least two points at the second versus first screening were classified as having a depressive mood. The other subjects served as the control group. The mean follow-up time was 1064 days, during which four subjects suffered an adverse vascular outcome (myocardial infarction: one man and one woman; stroke: two men). Among the variables used in the Cox proportional hazard models, a depressive mood, assessed by the Geriatric Depression Scale (GDS), as well as the MESOR of diastolic (D) BP (DBP-MESOR) and the circadian amplitude of systolic (S) BP (SBP-Amplitude) showed a statistically significant association with the occurrence of adverse vascular outcomes. The GDS score during the second but not during the first session was statistically significantly associated with the adverse vascular outcome. In univariate analyses, the relative risk (RR) of developing outcomes was predicted by a three-point increase in the GDS scale (RR = 3.088, 95% CI: 1.375-6.935, P = 0.0063). Increases of 5 mmHg in DBP-MESOR and of 3 mmHg in SBP-Amplitude were associated with RRs of 2.143 (95% CI: 1.232-3.727, P = 0.0070) and 0.700 (95% CI: 0.495-0.989, P = 0.0430), respectively. In multivariate analyses, when both the second GDS score and the DBP-MESOR were used as continuous variables in the same model, GDS remained statistically significantly associated with the occurrence of cardiovascular death. After adjustment for DBP-MESOR, a three-point increase in GDS score was associated with a RR of 2.172 (95% CI: 1.123-4.200). Monday endpoints of the 7-day profile showed a statistically significant association with adverse vascular outcomes. A 5 mmHg increase in DBP on Monday was associated with a RR of 1.576 (95% CI: 1.011-2.457, P = 0.0446). The main result of the present study is that in middle-aged community-dwelling people, a depressive mood predicted the occurrence of vascular diseases beyond the prediction provided by age, gender, ABP, lifestyle and environmental conditions, as assessed by means of a multivariate Cox model. A depressive mood, especially enhanced for 1-2 years, was associated with adverse vascular outcomes. Results herein suggest the clinical importance of repetitive assessments of a depressive mood and the need to take sufficient care of depressed subjects. Another result herein is that circadian and circaseptan characteristics of BP variability measured 7-day/24-h predicted the occurrence of vascular disease beyond the prediction provided by age, gender, depressive mood and lifestyle, as assessed by means of a multivariate Cox model. Earlier, we showed that the morning surge in BP on Mondays was statistically significantly higher compared with other weekdays. Although a direct association between the Monday surge in BP and cardiovascular events could not be demonstrated herein, it is possible that the BP surge on Monday mornings may also trigger cardiovascular events. We have shown that depressive people exhibit a more prominent circaseptan variation in SBP, DBP and the double product (DP) compared to non-depressed subjects. In view of the strong relation between depression and adverse cardiac events, studies should be done to ascertain that depression is properly diagnosed and treated. Chronodiagnosis and chronotherapy can reduce an elevated blood pressure and improve the altered variability in BP and HR, thus reducing the incidence of adverse cardiac events. This recommendation stands at the basis of chronomics, focusing on prehabilitation in preference to rehabilitation, as a public service offered in several Japanese towns.

25-Dehydro-1alpha-hydroxyvitamin D3-26,23S-lactone antagonizes the nuclear vitamin D receptor by mediating a unique noncovalent conformational change.

(23S)-25-dehydro-1alpha-Dihydroxyvitamin D3-26,23-lactone (TEI-9647; MK) has been reported to antagonize the 1alpha,25-dihydroxyvitamin D3 nuclear receptor (VDR)- mediated increase in transcriptional activity. Using a transient transfection system incorporating the osteocalcin VDRE (vitamin D response element) in Cos-1 cells, we found that 20 nM MK antagonizes VDR-mediated transcription by 50% when driven by 1 nM 1alpha,25(OH)2D3. Four analogs of 1alpha,25(OH)2D3, also at 1 nM, were antagonized 25 to 39% by 20 nM MK. However, analogs with 16-ene/23-yne or 20-epi modifications, which have a significantly lower agonist ED50 for the VDR than 1alpha,25(OH)2D3, were antagonized by 20 nM MK only at 100 pM or 10 pM, respectively. One possible mechanism for antagonism is that the 25-dehydro alkene of MK might covalently bind the ligand-binding site of the VDR rendering it inactive. Utilization of a ligand exchange assay, however, demonstrated that MK bound to VDR is freely exchanged with 1alpha,25(OH)2D3 in vitro. These data support the apparent correlation between VDR transcriptional activation by agonists and the effective range of MK antagonism by competition. Furthermore, protease sensitivity analysis of MK bound to VDR indicates the presence of a unique conformational change in the VDR ligand-binding domain, showing a novel doublet of VDR fragments centered at 34 kDa, whereas 1alpha,25(OH)2D3 as a ligand produces only a single 34-kDa fragment. In comparison, the natural metabolite 1alpha,25-dihydroxyvitamin D3-26,23-lactone yields only the 30-kDa fragment that is produced by all ligands to varying degrees. Collectively, these results support that MK is a potent partial antagonist of the VDR for 1alpha,25(OH)2D3 and its analogs when in appropriate excess of the agonist.

1 alpha,25-Dihydroxyvitamin D3[1 alpha,25-(OH)2D3]-26,23-lactone inhibits 1,25-(OH)2D3-mediated fusion of mouse bone marrow mononuclear cells.

Vitamin D3 and its hormonally active metabolite 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] can be metabolized to a number of daughter metabolites, including 1 alpha,25-(OH)2D3-26,23-lactone; this latter compound has four diastereoisomers. The 23(S),25(R)-lactone (naturally occurring) and the 23(R),25(S)-1 alpha,25-(OH)2D3-26,23-lactone are both known to be able to inhibit bone resorption induced by 1 alpha,25-(OH)2D3 under in vivo or in vitro conditions. To understand the mechanism of the inhibitory action of these two isomers on bone resorption we investigated the effects of 1 alpha,25-(OH)2D3-26,23-lactone on unfractionated mouse bone marrow cells in vitro. The addition of 1 alpha,25-(OH)2D3 to these cultures dose-dependently stimulated the formation of multinucleated cells over a range of 10(-9) - 10(-7) M. The 23(S),25(S)- and 23(R),25(R)-1 alpha,25-(OH)2D3-26,23-lactones also increased the number of multinucleated cells, whereas the 23(S),25(R)- and 23(R),25(S)-1 alpha,25-(OH)2D3-26,23-lactones failed to do so. In addition, these latter two diastereomers inhibited the 1 alpha,25-(OH)2D3 stimulation of multinucleated cell formation, although the 23(S),25(S)- and 23(R),25(R)-1 alpha,25-(OH)2D3-26,23-lactones and 24R,25-(OH)2D3 did not. These multinucleated cells responded to calcitonin and contained tartrate-resistant acid phosphatase, both of which are characteristic of osteoclasts. The present data suggest that inhibition of multinucleated cell formation is the mechanism by which the 23(S),25(R)- or 23(R),25(S)-1 alpha,25-(OH)2D3-26,23-lactone inhibits bone resorption induced by 1 alpha,25-(OH)2D3.

Effects of 1,25-dihydroxyvitamin D3 on osteoblastic MC3T3-E1 cells.

1,25-Dihydroxyvitamin D3 [1,25-(OH)2D3] was examined for a possible stimulative effect on osteoblastic MC3T3-E1 cells. During the early period of culture, 1,25-(OH)2D3 had a stimulative effect. During the growth phase, however, the steroid had little effect on either the protein or DNA content of the cultures. 1,25-(OH)2D3 increased bone-liver-kidney-type alkaline phosphatase activity in a dose-related manner up to a concentration of 5 pg/ml; the increase was 2.2-fold over the control value. Studies on the effect of actinomycin D or cycloheximide treatment indicated that the vitamin may enhance de novo synthesis of ALP. The steroid also stimulated type I collagen production dose dependently via an increase in collagen synthesis rather than by inhibition of collagen degradation. MC3T3-E1 cells have a specific receptor for 1,25-(OH)2D3 which has a dissociation constant of 4.17 X 10(-11) M and a sedimentation coefficient of 3.67S. The receptor concentration varied with the period of culture, being higher during the growth phase and lower at confluence, but its affinity did not change. The results indicate that 1,25-(OH)2D3 has a direct specific anabolic effect on osteoblastic cells in vitro during the growth phase and that this effect is related to receptor concentration.

Biological activity assessment of 1 alpha,25-dihydroxyvitamin D3-26,23-lactone and its intermediate metabolites in vivo and in vitro.

The biological activity of 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3], 23(S)25(R)-1 alpha,25(OH)2D3-26,23-lactone, and three intermediate metabolites of the lactone in vivo and in vitro was comparatively examined. The three intermediate metabolites, 1 alpha,25(R)26(OH)3D3, 1 alpha,23(S)25(R)26(OH)4D3, and 23(S)25(R)-1 alpha,25(OH)2D3-26,23-lactol, stimulated increases, as did 1 alpha,25(OH)2D3, in intestinal calcium transport and serum calcium level in vitamin D-deficient rats fed a low-calcium diet. On the other hand, 23(S)25(R)-1 alpha,25(OH)2D3-26,23-lactone increased the calcium transport but decreased the serum calcium level. 1 alpha,25(OH)2D3,23(S)25(R)-Lactone and the other three metabolites stimulated multinucleate cell formation from hematopoietic blast cells in a manner correlated with their binding affinities for the 1 alpha,25(OH)2D3 receptor. But 23(S)25(R)-lactone did not show any inhibitory effect on the multinucleate cell formation induced by 1 alpha,25(OH)2D3 in contrast to the results obtained from unfractionated marrow cultures. Conditioned medium obtained from 23(S)25(R)-lactone-treated MC3T3-E1 cells inhibited the formation, probably by the action of some inhibitory factors elaborated by the cells treated with the lactone, whereas conditioned medium obtained from 1 alpha,25(OH)2D3 or other metabolite-treated MC3T3-E1 cells stimulated the formation. These findings suggest that 23(S)25(R)-1 alpha,25(OH)2D3-26,23-lactone might inhibit bone resorption through an inhibition of osteoclastic cell formation and that other vitamin D3 metabolites stimulate bone resorption by development of new osteoclastic cells in addition to indirect osteoclast activation.

Antagonistic Actions in Vivo of (23S)-25-Dehydro-1alpha-Hydroxyvitamin D(3-)26,23-Lactone on Calcium Metabolism Induced by 1alpha,25-Dihydroxyvitamin D(3).

The vitamin D analog, (23S)-25-dehydro-1alpha-hydroxyvitamin D(3)-26,23-lactone (TEI-9647), is an antagonist of the 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)] nuclear receptor (VDR)-mediated differentiation of human leukemia (HL-60) cells. To clarify whether TEI-9647 could function as an antagonist of 1alpha,25(OH)(2)D(3) in vivo, we investigated in vitamin D-deficient (-D) rats the effects of single doses of TEI-9647 on several parameters of calcium metabolism modulated by 1alpha,25(OH)(2)D(3). TEI-9647 (50 microgram/kg iv) acting alone slightly, but significantly, stimulated intestinal calcium transport (ICA) and bone calcium mobilization (BCM) only at 8 h, but not at 24 h. In contrast, TEI-9647 dose-dependently inhibited ICA and BCM stimulated by an iv dose of 0.25 microgram/kg 1alpha,25(OH)(2)D(3) after 24 h, but not after 8 h. With respect to serum PTH levels, the administration of either TEI-9647, 50 microgram/kg, or 1alpha,25(OH)(2)D(3), 0.25 microgram/kg, began to decrease the circulating levels by 4 h, which reached a nadir 24 h after administration. But, when TEI-9647 and 1alpha,25(OH)(2)D(3) were simultaneously administered to -D rats, the TEI-9647 dose-dependently reversed the inhibition of PTH secretion caused by 1alpha,25(OH)(2)D(3), 0.25 microgram/kg, at 8 and 24 h after the treatment. In separate experiments, the daily iv administration of 20 microgram/kg of TEI-9647 alone to +D rats for 2 weeks resulted in no significant changes in the prevailing serum Ca(2+) concentration. But doses of 1-20 microgram/kg of TEI-9647 in combination with 0.5 microgram/kg of 1alpha,25(OH)(2)D(3), for 2 weeks, dose-dependently and significantly suppressed the serum calcium concentration increase caused by the 1alpha,25(OH)(2)D(3). Collectively, these results show that TEI-9647 acting alone displays in vivo weak agonistic actions, but when administered in combination with 1alpha,25(OH)(2)D(3), is a potent antagonist of three genomic-mediated calcium metabolism parameters. We conclude that TEI-9647 can also function as an antagonist of 1alpha,25(OH)(2)D(3) in vivo in the rat.

Effect of 24,25-dihydroxyvitamin D3 on 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] metabolism in vitamin D-deficient rats infused with 1,25-(OH)2D3.

Previous studies revealed that administration of 24,25-dihydroxyvitamin D3 [24,25-(OH)2D3] to calcium (Ca)-deficient rats causes a dose-dependent reduction in markedly elevated serum 1,25-(OH)2D3 level. Although the results suggested that the metabolism of 1,25-(OH)2D3 was accelerated by 24,25-(OH)2D3, those experiments could not define whether the enhanced metabolism of 1,25-(OH)2D3 played a role in the reduction in the serum 1,25-(OH)2D3 level. In the present study, in order to address this issue more specifically, serum 1,25-(OH)2D3 was maintained solely by exogenous administration through miniosmotic pumps of 1,25-(OH)2D3 into vitamin D-deficient rats. Thus, by measuring the serum 1,25-(OH)2D3 concentration, the effect of 24,25-(OH)2D3 on the MCR of 1,25-(OH)2D3 could be examined. Administration of 24,25-(OH)2D3 caused a dose-dependent enhancement in the MCR of 1,25-(OH)2D3, and 1 microgram/100 g rat.day 24,25-(OH)2D3, which elevated serum 24,25-(OH)2D3 to 8.6 +/- 1.3 ng/ml, significantly increased MCR and suppressed serum levels of 1,25-(OH)2D3. The effect of 24,25-(OH)2D3 on 1,25-(OH)2D3 metabolism developed with a rapid time course, and the recovery of iv injected [1 beta-3H]1,25-(OH)2D3 in blood was significantly reduced within 1 h. In addition, there was an increase in radioactivity in the water-soluble fraction of serum as well as in urine, suggesting that 1,25-(OH)2D3 is rapidly degraded to a water-soluble metabolite(s). Furthermore, the reduction in serum 1,25-(OH)2D3 was associated with a reduction in both serum and urinary Ca levels. Because the conversion of [3H]24,25-(OH)2D3 to [3H]1,24,25-(OH)2D3 or other metabolites was minimal in these rats, 24,25-(OH)2D3 appears to act without being converted into other metabolites. These results demonstrate that 24,25-(OH)2D3 rapidly stimulates the metabolism of 1,25-(OH)2D3 and reduces its serum level. It is suggested that 24,25-(OH)2D3 plays a role in modifying serum 1,25-(OH)2D3 concentrations by affecting the metabolism of 1,25-(OH)2D3 and may have a therapeutic values in the treatment of hypercalcemia or hypercalciuria caused by 1,25-(OH)2D3 excess.

Human osteoblasts in culture metabolize both 1 alpha, 25-dihydroxyvitamin D3 and its precursor 25-hydroxyvitamin D3 into their respective lactones.

1 alpha, 25-Dihydroxyvitamin D3 [1 alpha, 25-(OH)2D3], the hormonal form of vitamin D3, is further metabolized in the kidney and intestine through the carbon 24 (C-24) oxidation pathway initiated by C-24 hydroxylation, and the carbon 23 (C-23) oxidation pathway initiated by C-23 hydroxylation. The C-24 oxidation pathway leading to the formation of calcitroic acid has been previously reported to be present in bone cells, but the C-23 oxidation pathway leading to the formation of 1 alpha, 25-(OH)2D3-26,23-lactone has not been described in bone cells, even though 1 alpha, 25-(OH)2D3-26,23-lactone is noted to have a significant effect on bone formation. Therefore, in the present study, we investigated the production of 1 alpha, 25-(OH)2D3-26,23-lactone in normal human osteoblasts, and our studies revealed that human osteoblasts possess the activity of both 24- and 23-hydroxylases constitutively. Thus, 1 alpha, 24(R),25-(OH)3D3, 1 alpha, 25-(OH)2-24-oxo-D3, 1 alpha, 23(S), 25-(OH)3-24-oxo-D3, 1 alpha, 23-(OH)2-24,25,26,27-tetranor D3, and calcitroic acid formed through the C-24 oxidation pathway and 1 alpha, 23(S),25-(OH)3D3 and 1 alpha, 25-(OH)2D3-26,23-lactone formed through the C-23 oxidation pathway were detected under basal conditions. Also, the synthesis of these metabolites was increased significantly when the cells were treated with 1 alpha, 25-(OH)2D3 (50 nM) for 24 h before incubation with the tracer. As 25-hydroxyvitamin D3 (25OHD3) follows similar side-chain modifications as 1 alpha, 25-(OH)2D3, the metabolism of 25OHD3 in normal human osteoblasts was studied under basal conditions. We found that 25OHD3 was also metabolized through both C-24 and C-23 oxidation pathways, resulting in significant synthesis of 24(R),25-(OH)2D3 along with 25OH-24-oxo-D3, 23(S),25-(OH)2-24-oxo-D3, 23(S),25-(OH)2D3, and 25OHD3-26,23-lactone. Under the same experimental conditions, we looked for 1 alpha, 25-(OH)2D3 synthesis, as earlier studies have shown production of 1 alpha, 25-(OH)2D3 in human bone cells. During a time-course study ranging from 1-24 h, we found that by 2 h, the 24(R), 25-(OH)2D3 concentration rose and accumulated considerably during the following 24 h, but 1 alpha, 25-(OH)2D3 did not accumulate at any time. However, other 1-hydroxylated metabolites, 1 alpha, 23(S),25-(OH)3D3, 1 alpha, 23(S),25-(OH)3-24-oxo-D3, as well as 1 alpha, 25-(OH)2D3-26,23-lactone were detected.(ABSTRACT TRUNCATED AT 400 WORDS)

23(S),25(R)-1,25-dihydroxyvitamin D3-26,23-lactone stimulates murine bone formation in vivo.

23(S),25(R)-1,25-Dihydroxyvitamin D3-26,23-lactone (1,25-lactone) has been shown to have unique actions different from those of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. In contrast to 1,25-(OH)2D3, 1,25-lactone causes a significant reduction in the serum Ca2+ level, stimulates collagen production in an osteoblastic cell line, and inhibits bone resorption induced by 1,25-(OH)2D3. A possible effect of 1,25-lactone on bone formation was examined in experiments on ectopic bone formation using a bone-inducing factor derived from Dunn osteosarcomas. 1,25-Lactone, a metabolite of 1,25-(OH)2D3, increased [3H]proline uptake at the stage of chondrogenesis and 85Sr uptake during bone formation. Significantly enlarged bone was also induced by this compound 3 weeks after implantation. These results suggest that the 1,25-lactone may be able to stimulate bone formation under in vivo conditions.

The stereochemical configuration of the natural 23,25,26-trihydroxyvitamin D3.

Four possible diastereoisomers of 23,25,26-trihydroxyvitamin D3 were synthesized and compared with the natural metabolite. The 4 synthetic diastereoisomers could be separated into 4 peaks by high-performance liquid chromatography. The natural 23,25,26-trihydroxyvitamin D3 comigrated with 23(S),25(R),26-trihydroxyvitamin D3. This result unequivocally demonstrates that the stereochemistry of the natural 23,25,26-trihydroxyvitamin D3 has the 23(S) and 25(R) configuration.

1alpha,25-dihydroxyvitamin D(3)-26,23-lactone analogs antagonize differentiation of human leukemia cells (HL-60 cells) but not of human acute promyelocytic leukemia cells (NB4 cells).

We examined the effects of two novel 1alpha,25-dihydroxyvitamin D(3)-26,23-lactone (1alpha,25-(OH)(2)D(3)-26,23-lactone) analogs on 1alpha,25(OH)(2)D(3)-induced differentiation of human leukemia HL-60 cells thought to be mediated by the genomic action of 1alpha, 25-dihydroxyvitamin D(3) (1alpha,25-(OH)(2)D(3)) and of acute promyelocytic leukemia NB4 cells thought to be mediated by non-genomic actions of 1alpha,25-(OH)(2)D(3). We found that the 1alpha,25-(OH)(2)D(3)-26,23-lactone analogs, (23S)-25-dehydro-1alpha-hydroxyvitamin D(3)-26,23-lactone (TEI-9647) and (23R)-25-dehydro-1alpha-hydroxyvitamin D(3)-26,23-lactone (TEI-9648), inhibited differentiation of HL-60 cells induced by 1alpha,25-(OH)(2)D(3). However, 1beta-hydroxyl diastereomers of these analogs, i.e. (23S)-25-dehydro-1beta-hydroxyvitamin D(3)-26, 23-lactone (1beta-TEI-9647) and (23R)-25-dehydro-1beta-hydroxyvitamin D(3)-26,23-lactone (1beta-TEI-9648), did not inhibit differentiation of HL-60 cells caused by 1alpha,25-(OH)(2)D(3). A separate study showed that the nuclear vitamin D receptor (VDR) binding affinities of the 1-hydroxyl diastereomers were about 200 and 90 times weaker than that of 1alpha-hydroxyl diastereomers, respectively. Moreover, none of these lactone analogs inhibited NB4 cell differentiation induced by 1alpha,25-(OH)(2)D(3). In contrast, 1beta,25-dihydroxyvitamin D(3) (1beta,25-(OH)(2)D(3)) and 1beta,24R-dihydroxyvitamin D(3) (1beta,24R-(OH)(2)D(3)) inhibited NB4 cell differentiation but not HL-60 cell differentiation. Collectively, the results suggested that 1-hydroxyl lactone analogs, i.e. TEI-9647 and TEI-9648, are antagonists of 1alpha,25-(OH)(2)D(3), specifically for the nuclear VDR-mediated genomic actions, but not for non-genomic actions.

Chemistry and antimicrobial activity of caryoynencins analogs.

Caryoynencins (1) are antibiotics isolated from liquid cultures of a plant pathogen, Pseudomonas caryophylli, and are unstable C18 carboxylic acids with a conjugated dienetetrayne structure. Enyne analogs of caryoynencins were synthesized from monosilylated 1,3-butadiyne 2 (n = 2), 1,3,5-hexatriyne 2 (n = 3), and 1,3,5,7-octatetrayne 2 (n = 4) by alkynyl metal addition to 2,4-hexadienal (3) followed by allylic rearrangement and deprotection. Tetraynol 5 (n = 4) thus obtained was resolved by enzyme reactions. The conjugated dienetetrayne compounds are mixtures of 3E,5E- and 3E,5Z-isomers, which equilibrate by room light. 13C-NMR chemical shifts of polyynes obey simple rules, which can be used for signal assignments. Antimicrobial activities of conjugated enynes and related compounds were examined. The tetrayne analog 6 (n = 4) possesses potent antibacterial and antifungal activities, while triyne and diyne analogs 6 (n = 3 and 2) are less active. Chirality does not affect the activities. An isomeric enyne compound, 2,4-tetradecadiene-7,9,11,13-tetrayn-6-ol (8), showed potent activity against Tricophyton.

Synthesis, biological evaluation, and conformational analysis of A-ring diastereomers of 2-methyl-1,25-dihydroxyvitamin D(3) and their 20-epimers: unique activity profiles depending on the stereochemistry of the A-ring and at C-20.

All eight possible A-ring diastereomers of 2-methyl-1, 25-dihydroxyvitamin D(3) (2) and 2-methyl-20-epi-1, 25-dihydroxyvitamin D(3) (3) were convergently synthesized. The A-ring enyne synthons 19 were synthesized starting with methyl (S)-(+)- or (R)-(-)-3-hydroxy-2-methylpropionate (8). This was converted to the alcohol 14 as a 1:1 epimeric mixture in several steps. After having been separated by column chromatography, each isomer led to the requisite A-ring enyne synthons 19 again as 1:1 mixtures at C-1. Coupling of the resulting A-ring enynes 20a-h with the CD-ring portions 5a,b in the presence of a Pd catalyst afforded the 2-methyl analogues 2a-h and 3a-h in good yield. In this way, all possible A-ring diastereomers were synthesized. The synthesized analogues were biologically evaluated both in vitro and in vivo. The potency was highly dependent on the stereochemistry of each isomer. In particular, the alpha alpha beta-isomer 2g exhibited 4-fold higher potency than 1 alpha,25-dihydroxyvitamin D(3) (1) both in bovine thymus VDR binding and in elevation of rat serum calcium concentration and was twice as potent as the parent compound in HL-60 cell differentiation. Furthermore, its 20-epimer, that is, 20-epi-alpha alpha beta 3g, exhibited exceptionally high activities: 12-fold higher in VDR binding affinity, 7-fold higher in calcium mobilization, and 590-fold higher in HL-60 cell differentiation, as compared to 1 alpha,25-dihydroxyvitamin D(3) (1). Accordingly, the double modification of 2-methyl substitution and 20-epimerization resulted in unique activity profiles. Conformational analysis of the A-ring by (1)H NMR and an X-ray crystallographic analysis of the alpha alpha beta-isomer 2g are also described.

Suppression of the number of aberrant crypt foci of rat colorectum by ingestion of sugar beet fiber regardless of administration of anti-asialo GM1.

Anti-asialo GM1 serum (AGM1) reduces natural killer (NK) activity in vitro and in vivo. We investigated the effect of ingestion of sugar beet fiber (SBF) on 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) and whether the effect was maintained under NK-reducing conditions by AGM1 injection. The ingestion of SBF decreased the number of ACF in the colorectum at 4 weeks after treatment with DMH. Dietary SBF had a suppressive effect on the formation of ACF regardless of the administration of AGM1. These results suggest that the suppressive effect created by the ingestion of SBF may overwhelm the effect of AGM1 treatment on ACF formation.

Isolation and identification of 1alpha-hydroxy-24-oxovitamin D3 and 1alpha,23-dihydroxy-24-oxovitamin D3: metabolites of 1alpha,24(R)-dihydroxyvitamin D3 produced in rat kidney.

1alpha,24(R)-Dihydroxyvitamin D3 [1alpha,24(R)(OH)2D3], a synthetic vitamin D3 analog, has been developed as a drug for topical use in the treatment of psoriasis. At present, the target tissue metabolism of 1alpha,24(R)(OH)2D3 is not understood completely. In our present study, we investigated the metabolism of 1alpha,24(R)(OH)2D3 in the isolated perfused rat kidney. The results indicated that 1alpha,24(R)(OH)2D3 is metabolized in rat kidney into several metabolites, of which 1alpha,24(R),25-trihydroxyvitamin D3, 1alpha,25-dihydroxy-24-oxovitamin D3, 1alpha,23(S),25-trihydroxy-24-oxovitamin D3, and 1alpha,23-dihydroxy-24,25,26,27-tetranorvitamin D3 are similar to the previously known metabolites of 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3]. In addition to these aforementioned metabolites, we also identified two new metabolites, namely 1alpha-hydroxy-24-oxovitamin D3 and 1alpha,23-dihydroxy-24-oxovitamin D3. The two new metabolites do not possess the C-25 hydroxyl group. Thus, the metabolism of 1alpha,24(R)(OH)2D3 into both 25-hydroxylated and non-25-hydroxylated metabolites suggests that 1alpha,24(R)(OH)2D3 is metabolized in the rat kidney through two pathways. The first pathway is initiated by C-25 hydroxylation and proceeds further via the C-24 oxidation pathway. The second pathway directly proceeds via the C-24 oxidation pathway without prior hydroxylation at the C-25 position. Furthermore, we demonstrated that rat kidney did not convert 1alpha-hydroxyvitamin D3 [1alpha(OH)D3] into 1alpha,25(OH)2D3. This finding indicates that the rat kidney does not possess the classical vitamin D3-25-hydroxylase (CYP27) activity. However, from our present study it is apparent that prior hydroxylation of 1alpha(OH)D3 at the C-24 position in the 'R' orientation allows 25-hydroxylation to occur. At present, the enzyme responsible for the C-25 hydroxylation of 1alpha,24(R)(OH)2D3 is unknown. Our observation that the side chain of 1alpha,24(R)(OH)2D3 underwent 24-ketonization and 23-hydroxylation even in the absence of the C-25 hydroxyl group suggests that 1alpha,25(OH)2D3-24-hydroxylase (CYP24) can perform some steps of the C-24 oxidation pathway without prior C-25 hydroxylation. Thus, we speculate that CYP24 may be playing a dual role in the metabolism of 1alpha,24(R)(OH)2D3.

Effects of diastereoisomers of 1,25-dihydroxyvitamin D3-26,23-lactone on alkaline phosphatase and collagen synthesis in osteoblastic cells.

The effects of the four diastereoisomers of 1,25-dihydroxyvitamin D3-26,23-lactone (1,25-(OH)2D3-26,23-lactone) on alkaline phosphatase (AP) activity and collagen and noncollagen protein synthesis were examined in cultures of the osteoblastic clone MC3T3-E1 cell line. The four lactone diastereoisomers had little effect on the protein and DNA content of the cells. The 23(S),25(S)- and 23(R),25(R)-1,25-(OH)2D3-26,23-lactones increased AP activity in a linear dose-dependent fashion. Maximal effects were observed at 100 and 1000 pg/ml, respectively. In contrast, the naturally occurring 23(S),25(R)-, 1,25-(OH)2D3-26,23-lactone and the 23(R),25(S)-1,25-(OH)2D3-26,23-lactone showed biphasic stimulatory effects on AP activity. At both 80 and 10,000 pg/ml, they stimulated maximum increases in alkaline phosphatase activity. At 80 pg/ml the 23(S),25(R)- and 23(R),25(S)-isomers stimulated an increase in collagen synthesis, while at 10,000 pg/ml these isomers and 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) did not. Moreover, these two isomers (at 10,000 pg/ml) plus insulin or dexamethasone had an additive effect on AP activity, but not at 80 pg/ml. At 80 pg/ml but not at 10,000 pg/ml, the 23(S),25(R)-isomer had an additive effect on AP activity with the simultaneous addition of 25-hydroxyvitamin D3. Relative to 1,25-(OH)2D3, the binding affinities of 23(S),25(S)-, 23(R),25(R)-, 23(S),25(R)- and 23(R),25(S)-1,25-(OH)2D3-26,23-lactones were calculated to be 1/13.0, 1/131.8, 1/805.2, and 1/1083.3, respectively. No metabolites could be detected in the medium when [1-3H]23(S),25(R)-1,25-(OH)2D3-26,23-lactone (the naturally occurring diastereoisomer) was added to the cultures. However, the stimulative effects of 1,25-(OH)2D3 and the 23(S),25(R)-isomer at both concentrations were completely abolished by L-1-tosyl-amido-2-phenylethyl chloromethyl ketone. These results indicate that 1,25-(OH)2D3-lactone has a stimulative effect on osteoblastic cell functions in vitro. The naturally occurring 23(S),25(R)-1,25-(OH)2D3-lactone acts biphasically and may act on bone metabolism in vivo, possibly through a 1,25-(OH)2D3-receptor-mediated pathway.

Malignant pleural mesothelioma produces functional granulocyte-colony stimulating factor.

We report a patient with diffuse malignant pleural mesothelioma showing marked elevation of neutrophils. The level of serum granulocyte-colony stimulating factor (G-CSF) was elevated (138 pg/mL; normal range, < 20 pg/mL). The patient died 6 weeks after disease progression had been noted, and immunohistochemistry using a specific monoclonal antibody against recombinant G-CSF at autopsy demonstrated that the malignant mesothelioma cells actually produced G-CSF. Only three cases of malignant pleural mesothelioma, including the current patient, have been reported to produce G-CSF. We demonstrated an elevated serum level of G-CSF and G-CSF-bearing tumor cells by immunochemistry.

Dietary sugar beet fiber ameliorates diarrhea as an acute gamma-radiation injury in rats.

Gamma radiation induces diarrhea as an acute injury. We have studied whether ingestion of sugar beet fiber influences radiation-induced diarrhea. Abdominal irradiation with gamma rays induced diarrhea in male Wistar/ST rats from 2 to 7 days after a single sublethal dose. The body weight of the irradiated rats was decreased temporarily at 4 days after irradiation regardless of the ingestion of sugar beet fiber. At day 8, it returned to almost the same level as that of unirradiated rats. A change in daily food intake resulted in a pattern similar to that for body weight. Dietary sugar beet fiber had little significant effect on the changes in body weight and daily food intake, and its ingestion significantly decreased gamma-ray-induced diarrhea. Changes in biochemical and histological parameters in intestinal mucosa (small intestine, cecum and colon) were not greatly influenced by the ingestion of sugar beet fiber through the periods of diarrhea. It was concluded that dietary sugar beet fiber ameliorated the diarrhea induced by abdominal irradiation. We suggest that the inhibitory effect of the ingestion of sugar beet fiber is due to its effects on the luminal environment, such as support for bacterial function in the luminal contents in the colon of animals that ingest sugar beet fiber.