135 research outputs found

    Sp1 up-regulates cAMP-response-element-binding protein expression during retinoic acid-induced mucous differentiation of normal human bronchial epithelial cells.

    Get PDF
    CREB [CRE (cAMP-response element)-binding protein] is an important transcription factor that is differentially regulated in cells of various types. We recently reported that RA (retinoic acid) rapidly activates CREB without using RARs (RA receptors) or RXRs (retinoid X receptors) in NHTBE cells (normal human tracheobronchial epithelial cells). However, little is known about the role of RA in the physiological regulation of CREB expression in the early mucous differentiation of NHTBE cells. In the present study, we report that RA up-regulates CREB gene expression and that, using 5\u27-serial deletion promoter analysis and mutagenesis analyses, two Sp1 (specificity protein 1)-binding sites located at nt -217 and -150, which flank the transcription initiation site, are essential for RA induction of CREB gene transcription. Furthermore, we found that CREs located at nt -119 and -98 contributed to basal promoter activity. Interestingly, RA also up-regulated Sp1 in a time- and dose-dependent manner. Knockdown of endogenous Sp1 using siRNA (small interfering RNA) decreased RA-induced CREB gene expression. However, the converse was not true: knockdown of CREB using CREB siRNA did not affect RA-induced Sp1 gene expression. We conclude that RA up-regulates CREB gene expression during the early stage of NHTBE cell differentiation and that RA-inducible Sp1 plays a major role in up-regulating human CREB gene expression. This result implies that co-operation of these two transcription factors plays a crucial role in mediating early events of normal mucous cell differentiation of bronchial epithelial cells

    Effect of the secondary structure in the Euglena gracilis chloroplast ribulose-bisphosphate carboxylase/oxygenase messenger RNA on translational initiation.

    Get PDF
    The results reported in the previous paper indicate that the translational start site of the Euglena gracilis chloroplast mRNA for the large subunit of ribulose-bisphosphate carboxylase/oxygenase (rbcL) is not defined by primary sequence elements (Koo, J.S., and Spremulli, L.L. (1994) J. Biol. Chem. 269, 7494-7500). In the work presented here, the effects of secondary structure in the 5'-untranslated leader of the rbcL mRNA have been examined. Only weak secondary structure can be detected in the 5'-untranslated leader of the rbcL message by enzymatic and computer analysis. Further reduction of the weak secondary structure of this message by site-directed mutagenesis does not significantly affect the ability of this message to participate in initiation complex formation. The secondary structure near the translational start site was increased by the introduction of an inverted repeat sequence and by site-directed mutagenesis. Messages with increased secondary structure are much less active in initiation complex formation if the structural element introduced is within approximately 10 nucleotides of the start codon. These results suggest that the translational start site in this chloroplast mRNA is specified by the presence of an AUG codon in an unstructured or weakly structured region of the mRNA. No specific sequences around the start codon, either upstream or immediately downstream, were found to have important information directing the chloroplast ribosome to the start site of this mRNA

    Analysis of the translational initiation region on the Euglena gracilis chloroplast ribulose-bisphosphate carboxylase/oxygenase (rbcL) messenger RNA

    Get PDF
    The chloroplast mRNAs from Euglena gracilis fall into two classes. One group of mRNAs from this organelle contains a Shine-Dalgarno sequence 5' to the start codon, while the other group of mRNAs does not have a conserved sequence signal in the 5'-untranslated region. To investigate the start signals for E. gracilis chloroplast mRNAs that do not carry a Shine-Dalgarno sequence, 90 S initiation complex formation has been studied using a series of transcripts carrying the wild-type translational start site of ribulose-bisphosphate carboxylase/ oxygenase (rbcL) or mutated derivatives of this site

    A comparative analysis of data generated using two different target preparation methods for hybridization to high-density oligonucleotide microarrays

    Get PDF
    BACKGROUND: To generate specific transcript profiles, one must isolate homogenous cell populations using techniques that often yield small amounts of RNA, requiring researchers to employ RNA amplification methods. The data generated by using these methods must be extensively evaluated to determine any technique dependent distortion of the expression profiles. RESULTS: High-density oligonucleotide microarrays were used to perform experiments for comparing data generated by using two protocols, an in vitro transcription (IVT) protocol that requires 5 μg of total RNA and a double in vitro transcription (dIVT) protocol that requires 200 ng of total RNA for target preparation from RNA samples extracted from a normal and a cancer cell line. In both cell lines, about 10% more genes were detected with IVT than with dIVT. Genes were filtered to exclude those that were undetected on all arrays. Hierarchical clustering using the 9,482 genes that passed the filter showed that the variation attributable to biological differences between samples was greater than that introduced by differences in the protocols. We analyzed the behavior of these genes separately for each protocol by using a statistical model to estimate the posterior probability of various levels of fold change. At each level, more differentially expressed genes were detected with IVT than with dIVT. When we checked for genes that had a posterior probability greater than 99% of fold change greater than 2, in data generated by IVT but not dIVT, more than 60% of these genes had posterior probabilities greater than 90% in data generated by dIVT. Both protocols identified the same functional gene categories to be differentially expressed. Differential expression of selected genes was confirmed using quantitative real-time PCR. CONCLUSION: Using nanogram quantities on total RNA, the usage of dIVT protocol identified differentially expressed genes and functional categories consistent with those detected by the IVT protocol. There was a loss in sensitivity of about 10% when detecting differentially expressed genes using the dIVT protocol. However, the lower amount of RNA required for this protocol, as compared to the IVT protocol, renders this methodology a highly desirable one for biological systems where sample amounts are limiting

    Induction of the Cytochrome P450 Gene CYP26 during Mucous Cell Differentiation of Normal Human Tracheobronchial Epithelial Cells

    Get PDF
    ABSTRACT In this study, the expression of CYP26 is examined in relation to retinoid-induced mucosecretory differentiation in human tracheobronchial epithelial (HTBE) cells and compared with that in human lung carcinoma cell lines. In HTBE cells, retinoic acid (RA) inhibits squamous differentiation and induces mucous cell differentiation as indicated by the suppression of transglutaminase I and increased expression of the mucin gene MUC2. The latter is accompanied by increased expression of CYP26 mRNA. RA is required but not sufficient to induce RAR␤, CYP26, and MUC2 mRNA because induction is only observed in confluent but not in logarithmic cultures, suggesting that additional factors are critical in their regulation. CYP26 mRNA can be induced by the RAR-selective retinoid 4-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-anthracenyl)-benzoic acid (TTAB) but not by the RXR-selective retinoid SR11217 or the antiactivator-protein 1-selective retinoid SR11302. RAR␣-, ␤-, and ␥-selective retinoids are able to induce CYP26; this induction is inhibited by the RAR␣-selective antagonist Ro41-5253. TTAB is able to induce CYP26 mRNA expression in only a few of the lung carcinoma cell lines tested. The lack of CYP26 induction in many carcinoma cell lines may relate to previously reported defects in the retinoid-signaling pathway. The induction of CYP26 correlated with increased metabolism of RA into 18-hydroxy-, 4-oxo-, and 4-hydroxy-RA. The latter metabolite was shown to be able to induce MUC2 and MUC5AC expression in HTBE cells. Our results demonstrate that in normal HTBE cells, CYP26 expression is closely associated with mucous cell differentiation and that many lung carcinoma cells exhibit increased RA metabolism and a defective regulation of CYP26

    Problematic Use of Alcohol and Online Gaming as Coping Strategies During the COVID-19 Pandemic: A Mini Review

    Get PDF
    The COVID-19 (coronavirus disease 2019) pandemic has dramatically changed our daily lives and activities, including those originally intended to serve for leisure and pleasure. Drinking and online gaming became coping behaviors used to rescue ourselves from the stress and restricted lifestyle during the COVID-19 pandemic. However, frequent drinking and gaming can result in the pathological consequences of addiction. Those affected use the stimuli not to obtain pleasure, but rather to avoid the displeasure induced by stress and previous use, often unsuccessfully. This review aims to provide an overview of recent longitudinal cohort studies on alcohol and gaming use during the COVID-19 pandemic, as well as to analyze how the pandemic has affected alcohol and gaming use. There was a substantial risk of alcohol and online gaming overuse during the lockdown, which may depend on the pandemic's duration or overuse patterns. Previous studies have shown that increased alcohol consumption and online gaming are associated with heightened stress and anxiety levels caused by social isolation/quarantine. Over time, frequent or excessive alcohol consumption and gaming could lead to an increased risk of more serious mental health problems. Every effort should be made to mitigate mental health problems and ensure adequate adaptation to these exceptional circumstances. Therefore, it would be helpful to encourage physical activity, social interaction, and collaboration to facilitate psychological and physical health. © Copyright © 2021 Xu, Park, Kang, Choi and Koo.1

    Correlation of clinical parameters with endolymphatic hydrops on MRI in Meniere's disease

    Get PDF
    A clinical diagnosis of Ménière's disease (MD) is made based on medical history and audiometry findings. The 1995 American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) guidelines requires histopathological confirmation of endolymphatic hydrops (EH) for a diagnosis of “certain” MD. Symptoms such as dizziness and ear fullness are important diagnostic features; however, the descriptions provided by patients are frequently vague and non-specific. A recently developed magnetic resonance imaging (MRI) protocol to document EH is, therefore, useful for the evaluation of inner ear status in patients with MD. In this study, patients with MD were assessed using MRI and the HYDROPS (HYbriD of Reversed image Of Positive endolymph signal and native image of positive perilymph Signal) protocol to investigate the effectiveness of MRI for visualization of the endolymphatic space in the diagnosis of MD by correlating clinical laboratory parameters with the grade of EH. Of the 123 patients with MD recruited in this study, 80 had definite MD, 11 had probable MD, and 32 had possible MD based on the 1995 AAO-HNS guidelines. The EH grade based on HYDROPS MRI was determined independently by two otorhinolaryngologists and compared with several clinical parameters, including the diagnostic scale of MD (1995 AAO-HNS guidelines), pure tone average (PTA), low tone average (LTA), canal paresis (CP) on the caloric test, and disease duration. Cochlear hydrops and vestibular hydrops were detected in 58 and 80% of 80 definite MD ears, in 33 and 58% of 12 probable MD ears, and in 5 and 27% of 37 possible MD ears, respectively. The proportion of higher hydrops grades increased significantly with grade according to the MD diagnostic scale (p < 0.0001). Both PTA and LTA were significantly higher in patients with hydrops grade 2 than hydrops grade 0 in both the cochlea and the vestibule. CP was significantly higher in patients with grade 2 than grade 0 vestibular hydrops. Disease duration was not associated with hydrops grade. Radiological evaluation of MD using the HYDROPS protocol is useful for evaluation of the extent and severity of EH in the diagnosis of MD based on its pathophysiological mechanism

    Social isolation impairs the prefrontal-nucleus accumbens circuit subserving social recognition in mice

    Get PDF
    Although medial prefrontal cortex (mPFC) is known to play important roles in social behaviors, how early social experiences affect the mPFC and its subcortical circuit remains unclear. We report that mice singly housed (SH) for 8 weeks after weaning show a social recognition deficit, even after 4 weeks of resocialization. In SH mice, prefrontal infralimbic (IL) neurons projecting to the shell region of nucleus accumbens (NAcSh) show decreased excitability compared with group-housed (GH) mice. NAcSh-projecting IL neurons are activated when GH mice encounter a familiar conspecific, which is not observed in SH mice. Chemogenetic inhibition of NAcSh-projecting IL neurons in normal mice impairs social recognition without affecting social preference, whereas activation of these neurons reverses social recognition deficit in SH mice. Our findings demonstrate that early social experience critically affects mPFC IL-NAcSh projection, the activation of which is required for social recognition by encoding information for social familiarity. © 2021 The Author(s)1

    Abnormal Vestibular Evoked Myogenic Potentials in Medial Medullary Infarction

    Get PDF
    Background The medial vestibulospinal tract (MVST), which descends in the medial longitudinal fasciculus (MLF), may mediate the vestibular evoked myogenic potentials (VEMPs) in the contracting sternocleidomastoid muscle. We report herein abnormal VEMPs in a patient with medial medullary infarction (MMI) that appeared to involve the MLF. Case Report A patient with infarction involving the right medial medulla showed decreased p13-n23 amplitude and increased p13/n23 latencies of the VEMPs on the right side. These abnormal VEMPs recorded in all MMI patient support the theory that VEMPs are mediated by the MVST contained within the MLF. Conclusions VEMPs may represent a valuable tool for investigating vestibular dysfunction originating from the saccule, even ill patients with central vestibulopathies, which is not readily defined by conventional vestibular function tests. J Clin Neurol 2009;5:101-103This study was supported by a grant of the Korea Health 21 R&D Project, Ministry of Health & Welfare, Republic of Korea (A080750). The authors thank Jong-Hee Lee for experimental assistance.Kim JS, 2005, NEUROLOGY, V65, P1294Welgampola MS, 2005, NEUROLOGY, V64, P1682Newlands SD, 2003, J COMP NEUROL, V466, P31, DOI 10.1002/cne.10876Chen CH, 2003, LARYNGOSCOPE, V113, P990Murofushi T, 1999, ARCH OTOLARYNGOL, V125, P660Murofushi T, 1996, ARCH OTOLARYNGOL, V122, P845WILSON VJ, 1995, J VESTIBUL RES-EQUIL, V5, P147MUROFUSHI T, 1995, EXP BRAIN RES, V103, P174ROBERTSON DD, 1995, J OTOLARYNGOL, V24, P3COLEBATCH JG, 1994, J NEUROL NEUROSUR PS, V57, P190COLEBATCH JG, 1992, NEUROLOGY, V42, P1635AKAIKE T, 1983, BRAIN RES, V259, P217FERNANDEZ C, 1976, J NEUROPHYSIOL, V39, P970POMPEIANO O, 1957, ARCH ITAL BIOL, V95, P166
    corecore