ADAR1 deaminase contributes to scheduled skeletal myogenesis progression via stage-specific functions.

Adenosine deaminases acting on RNA 1 (ADAR1) catalyzes cellular RNA adenosine-to-inosine editing events on structured RNA molecules. In line with this critical role, ADAR1 exhibits ubiquitous expression and is essential for embryonic development. However, regulation and developmental significance of this RNA editor in a spatiotemporal context are largely elusive. Here we unveil a novel tissue-specific role of ADAR1 in skeletal myogenesis. ADAR1 expression displayed programmed alteration that is coordinated with differentiation cues, and mediated negatively by miRNA-1/206. Coincidently, ADAR1 exerts stage-dependent functions-suppression of apoptosis at the onset of differentiation and preservation of timely myotube formation through later phase. Furthermore, the post-transcriptional aspect of its myogenic role was illustrated by the spectrum of binding RNAs, as revealed by high-throughput approach, as well as by direct regulation of myogenesis-associated targets such as dynamin 1/2 (Dnm1/2) and annexin A4. Consequently, maintenance of target gene expression profiles likely contributes to a state of cytoskeleton and membrane dynamics that is amenable to myoblast morphogenesis. Collectively, these findings uncover a critical link of ADAR1 to myogenesis, and further highlight an epigenetic mechanism by which ADAR1 and miR-1/206 interplay to control scheduled myoblast-myotube transition.

The role of DAB2IP in androgen receptor activation during prostate cancer progression.

Altered androgen-receptor (AR) expression and/or constitutively active AR are commonly associated with prostate cancer (PCa) progression. Targeting AR remains a focal point for designing new strategy of PCa therapy. Here, we have shown that DAB2IP, a novel tumor suppressor in PCa, can inhibit AR-mediated cell growth and gene activation in PCa cells via distinct mechanisms. DAB2IP inhibits the genomic pathway by preventing AR nuclear translocation or phosphorylation and suppresses the non-genomic pathway via its unique functional domain to inactivate c-Src. Also, DAB2IP is capable of suppressing AR activation in an androgen-independent manner. In addition, DAB2IP can inhibit several AR splice variants showing constitutive activity in PCa cells. In DAB2IP(-/-) mice, the prostate gland exhibits hyperplastic epithelia, in which AR becomes more active. Consistently, DAB2IP expression inversely correlates with AR activation status particularly in recurrent or metastatic PCa patients. Taken together, DAB2IP is a unique intrinsic AR modulator in normal cells, and likely can be further developed into a therapeutic agent for PCa.

Acupuncture versus topiramate in chronic migraine prophylaxis: a randomized clinical trial.

BACKGROUND: The aim of this study was to investigate the efficacy and tolerability of acupuncture compared with topiramate treatment in chronic migraine (CM) prophylaxis. METHODS: A total of 66 consecutive and prospective CM patients were randomly divided into two treatment arms: 1) acupuncture group: acupuncture administered in 24 sessions over 12 weeks (n = 33); and 2) topiramate group: a 4-week titration, initiated at 25 mg/day and increased by 25 mg/day weekly to a maximum of 100 mg/day followed by an 8-week maintenance period (n = 33). RESULTS: A significantly larger decrease in the mean monthly number of moderate/severe headache days (primary end point) from 20.2 ± 1.5 days to 9.8 ± 2.8 days was observed in the acupuncture group compared with 19.8 ± 1.7 days to 12.0 ± 4.1 days in the topiramate group (p < .01) Significant differences favoring acupuncture were also observed for all secondary efficacy variables. These significant differences still existed when we focused on those patients who were overusing acute medication. Adverse events occurred in 6% of acupuncture group and 66% of topiramate group. CONCLUSION: We suggest that acupuncture could be considered a treatment option for CM patients willing to undergo this prophylactic treatment, even for those patients with medication overuse.

Androgen induces expression of the multidrug resistance protein gene MRP4 in prostate cancer cells.

Multidrug resistance-associated proteins (MRPs) may mediate multidrug resistance in tumor cells. Using a gene array analysis, we have identified MRP4 as an androgen receptor (AR)-regulated gene. Dihydrotestosterone induced MRP4 expression in both androgen-dependent and -independent LNCaP cells, whereas there was little detectable expression in PC-3 or normal prostate epithelial cells. Disruption of MRP4 expression renders LNCaP cells more sensitive to the cytotoxic effects of methotrexate but not etoposide. Analysis of human tissues showed detectable MRP4 expression only in metastatic prostate cancer. These results suggest that AR induction of MRP4 mediates resistance of PC cells to nucleotide-based chemotherapeutic drugs.

Chromosomal instability by beta-catenin/TCF transcription in APC or beta-catenin mutant cells.

Adenomatous polyposis coli (APC/Apc) gene encodes a key tumor suppressor whose mutations activate beta-catenin/T-cell factor (TCF)-mediated transcription (canonical Wnt signaling). Here, we show that Wnt signaling can cause chromosomal instability (CIN). As an indicator of CIN, we scored anaphase bridge index (ABI) in mouse polyps and ES cells where Wnt signaling was activated by Apc or beta-catenin mutations. We found three to nine times higher ABI than in wild-type controls. Furthermore, karyotype analysis confirmed that the Wnt signal-activated ES cells produced new chromosomal aberrations at higher rates; hence CIN. Consistently, expression of dominant-negative TCFs in these cells reduced their ABI. We also found that Wnt signal activation increased phosphorylation of Cdc2 (Cdk1) that inhibited its activity, and suppressed apoptosis upon exposure of the cells to nocodazole or colcemid. The data suggest that Wnt signaling stimulates the cells to escape from mitotic arrest and apoptosis, resulting in CIN. In human gastric cancer tissues with nuclear beta-catenin, ABI was significantly higher than in those without. These results collectively indicate that beta-catenin/TCF-mediated transcription itself increases CIN through dysregulation of G2/M progression.

c-Jun enhancement of androgen receptor transactivation is associated with prostate cancer cell proliferation.

Androgens and the androgen receptor (AR) are involved in the growth and progression of prostate cancer. Our previous studies suggest that the proto-oncoprotein c-Jun is an AR coactivator that stimulates AR transactivation by mediating receptor dimerization and subsequent DNA binding. To study the physiological relevance of this c-Jun activity on AR, we have generated stable LNCaP cell lines expressing different levels of c-Jun. These cell lines exhibit a direct correlation between endogenous c-Jun levels and AR transcriptional activity and expression of endogenous androgen-regulated genes. Disruption by antisense RNA of endogenous c-Jun expression in LNCaP cells strongly compromises the androgen-dependent proliferation of these cells. In contrast, expression of a c-Jun mutant, which is fully active in coactivation of AR but deficient in AP-1 transactivation, significantly enhances androgen-dependent proliferation. This finding indicates that the coactivation function of c-Jun is sufficient for regulating androgen-induced growth of LNCaP cells. c-Jun also enhances AR transactivtion in androgen-independent LNCaP cells, which closely mimic hormone-refractory prostate cancer cells in gene expression and growth behavior. Importantly, siRNA-mediated repression of endogenous c-Jun expression results in markedly reduced growth of these cells, strongly suggesting an important biological role for c-Jun in hormone-refractory prostate cancer.

A luciferase transgenic mouse model: visualization of prostate development and its androgen responsiveness in live animals.

Numerous mouse models of prostate carcinogenesis have been developed, but hitherto there has been no model in which the prostate gland could be imaged in live animals. The transgenic model generated here targeted mouse prostate gland using a firefly luciferase enzyme under the control of a small but highly active and specific supra prostate-specific antigen (sPSA) promoter. We evaluated postnatal prostate development, involution and androgen-induced restoration of prostate growth in adult transgenic mice using bioluminescence imaging. Results of our study showed that: (i) the prostate gland of male offspring did not yield a significant bioluminescence signal until after sexual maturity. Luciferase was detected in the luminal epithelial cells of the ventral and dorsolateral lobes of the prostate gland and caput epididymis, with little or no activity in 18 other organs evaluated. (ii) While a constant high level of bioluminescence was detected in the mouse prostate from 5 to 35 weeks of age, a slight drop in bioluminescence was detected at 36 to 54 weeks. (iii) Upon castration, the luciferase activity signal associated with mouse prostate detected by a cooled charge-coupled device camera was dramatically reduced. This signal could be rapidly restored to pre-castration levels after androgen administration. Androgen-induced luciferase activity subsided to nearly basal levels 5 days following the last injection. These data demonstrate that a bioluminescent mouse model with luciferase activity restricted to the prostate gland under the control of a (sPSA) promoter can be used on a real-time basis in live animals to investigate the development and responsiveness of the prostate gland to exogenously administered androgen. This model can be extended to detect the responsiveness of the prostate gland to therapy and used as a founder strain to visualize tumors in hosts with different genetic backgrounds.

Morin sulphates/glucuronides enhance macrophage function in microgravity culture system.

BACKGROUND: The immune system changes significantly in astronauts during and after space flight. Although the mechanism has not been defined, it is reasonable to begin developing effective countermeasures to the physiological consequences of spaceflight, especially immunosuppression. Many studies have been published about the effect of flavonoids on immune modulation. Thus, the aim of this study was to develop whether flavonoids could be the effective countermeasures to the immunosuppression caused by microgravity. MATERIALS AND METHODS: We used a rotating wall vessel 3D (three-dimensional) culture system which recreates some of the culture conditions that occur during microgravity to study the effects of microgravity on the function of macrophages and assess the modulating effects of flavonoids on microgravity-induced macrophage dysfunction. RESULTS: We demonstrated 65% and 80% reduction in mitogen-induced nitric oxide and cytokine production of 3D-cultured macrophages, compared to conventional two-dimensional (2D)-cultured cells. Moreover, the microgravity-induced macrophage dysfunction was not restored by transferring cells from 3D to 2D culture. However, the addition of morin sulphates/glucuronides in 3D culture compensated for the loss of macrophage function. CONCLUSION: The result presented here suggests for the first time that an immune-modulatory strategy using flavonoid supplements such as morin would benefit the health of astronauts.

Prediction of poststroke dementia.

OBJECTIVE: To investigate prospectively the frequency and clinical determinants of poststroke dementia (PSD) in a cohort of consecutive ischemic stroke inpatients in southern Taiwan. METHODS: A standard stroke evaluation protocol was conducted at admission and 3 months after an ischemic stroke. The protocol included clinical, neurologic, neurobehavioral, and functional assessments as well as neuroimaging examinations. Diagnoses were made according to the Neurologic Adaptation of the 10th edition of the International Classification of Diseases criteria for dementia. RESULTS: Excluding patients with prestroke dementia, a total of 283 patients were surveyed at 3 months after stroke; 26 (9.2%) of them met the criteria for PSD. The correlates of PSD in logistic regression analyses were age 65 years or older (odds ratio [OR] 6.6) vs <65 years, previous occupation as a laborer (OR 3.3), prior stroke (OR 3.1), left carotid vascular territory (OR 12.5) vs vertebrobasilar and unknown territories, moderate to severe stroke severity (OR 3.4), and cognitive impairment (OR 4.5) and poorer functional status at admission (OR 4.5). Based on the significant predictors identified, the logistic regression model correctly classified PSD in 93.4% of subjects. CONCLUSION: The lower frequency of PSD in this study from Taiwan compared with previous studies from Western countries may have been due to the relatively younger age of the elderly population and the use of stricter diagnostic criteria.

Comparison of the psychometric characteristics of the functional independence measure, 5 item Barthel index, and 10 item Barthel index in patients with stroke.

OBJECTIVES: To compare the reliability, validity, and responsiveness of the motor subscale of the functional independence measure (FIM), the original 10 item Barthel index (BI), and the 5 item short form BI (BI-5) in inpatients with stroke receiving rehabilitation. METHODS: 118 inpatients with stroke at a rehabilitation unit participated in the study. The patients were tested with the FIM motor subscale and original BI at admission to the rehabilitation ward and before discharge from the hospital. The distribution, internal consistency, concurrent validity, and responsiveness of each measure were examined. RESULTS: The BI and FIM motor subscale showed acceptable distribution, high internal consistency (alpha coefficient > or = 0.84), high concurrent validity (Spearman's correlation coefficient, r(s) > or = 0.92, intraclass correlation coefficient (ICC) > or = 0.83), and high responsiveness (standardised response mean > or = 1.2, p < 0.001). The BI-5 exhibited a notable floor effect at admission but this was not found at discharge. The BI-5 showed acceptable internal consistency at admission and discharge (alpha coefficient > or = 0.71). The concurrent validity of the BI-5 was poor to fair at admission (r(s) = 0.74, ICC < or = 0.55) but was good at discharge (r(s) > or = 0.92, ICC > or = 0.74). It is noted that the responsiveness of the BI-5 was as high as that of the BI and the FIM motor subscale. CONCLUSIONS: The results showed that the BI and FIM motor subscale had very acceptable and similar psychometric characteristics. The BI-5 appeared to have limited discriminative ability at admission, particularly for patients with severe disability; otherwise the BI-5 had very adequate psychometric properties. These results may provide information useful in the selection of activities of daily living measures for both clinicians and researchers.

Effects of young barley leaf extract and antioxidative vitamins on LDL oxidation and free radical scavenging activities in type 2 diabetes.

BACKGROUND: The effects of supplementation of young barley leaf extract (BL) and/or antioxidative vitamins C and E on different low-density lipoprotein (LDL) subfractions susceptibility to oxidation and free radical scavenging activities in patients with type 2 diabetes were evaluated. METHODS: Thirty-six type 2 diabetic patients were enrolled in this study. The subjects received one of the following supplements daily for 4 weeks: 15 g BL, 200 mg vitamin C and 200 mg vitamin E (CE), or BL plus CE (BL + CE). RESULTS: The lucigenin-chemiluminescence (CL) and luminol-CL levels in blood were significantly reduced in all groups. Vitamin E content of LDL subfractions increased significantly following supplements, especially for BL + CE group. The percent increase of lag times in the BL + CE was significantly higher than those in the BL or CE group. The antioxidative effect of BL + CE was the greatest for small, dense LDL (Sd-LDL) with further increases in percentage of lag times 4 folds compared to BL alone. CONCLUSION: Our results indicate that supplementation with BL may help to scavenge oxygen free radicals, save the LDL-vitamin E content, and inhibit LDL oxidation. Furthermore, the addition of vitamins C and E to BL can inhibit the Sd-LDL oxidation more effectively, which may protect against vascular diseases in type 2 diabetic patients.