Tau, Glial Fibrillary Acidic Protein, and Neurofilament Light Chain as Brain Protein Biomarkers in Cerebrospinal Fluid and Blood for Diagnosis of Neurobiological Diseases.

Neurological damage is the pathological substrate of permanent disability in various neurodegenerative disorders. Early detection of this damage, including its identification and quantification, is critical to preventing the disease's progression in the brain. Tau, glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL), as brain protein biomarkers, have the potential to improve diagnostic accuracy, disease monitoring, prognostic assessment, and treatment efficacy. These biomarkers are released into the cerebrospinal fluid (CSF) and blood proportionally to the degree of neuron and astrocyte damage in different neurological disorders, including stroke, traumatic brain injury, multiple sclerosis, neurodegenerative dementia, and Parkinson's disease. Here, we review how Tau, GFAP, and NfL biomarkers are detected in CSF and blood as crucial diagnostic tools, as well as the levels of these biomarkers used for differentiating a range of neurological diseases and monitoring disease progression. We also discuss a biosensor approach that allows for the real-time detection of multiple biomarkers in various neurodegenerative diseases. This combined detection system of brain protein biomarkers holds significant promise for developing more specific and accurate clinical tools that can identify the type and stage of human neurological diseases with greater precision.

Blepharoptosis among Korean adults: age-related prevalence and threshold age for evaluation.

BACKGROUND: To evaluate the prevalence of blepharoptosis among Korean adults and the characteristics of blepharoptosis patients, and to determine an appropriate age threshold for recommending blepharoptosis evaluation. METHODS: The Korean National Health and Nutrition Examination Survey (KNHANES-V) was conducted in 2010-2012. We extracted data on 17,878 Korean adults aged more than and equal to 19 years included in KNHANES-V, and determined blepharoptosis prevalence according to age, to determine the cutoff age for recommending blepharoptosis evaluation. We also determined the possible association between blepharoptosis and obesity parameters, such as body mass index (BMI) and waist circumference (WC). RESULTS: There was astrong association between older age and the prevalence of blepharoptosis. The cutoff age for recommending blepharoptosis evaluation was 63 years for males, 70 years for females, and 66 years for all patients. Patients with a high BMI and large WC had a higher prevalence of blepharoptosis in all age groups except for those aged over 80 years. The association of blepharoptosis with BMI according to age group showed that in the 50-59 and 60-69 years age groups, blepharoptosis prevalence and BMI were higher. However, in the 70-79 and 80-89 years age groups, extremely obese patients (BMI > 30) showed a decreased blepharoptosis prevalence. CONCLUSIONS: Moderate to severe blepharoptosis can result in poor visual function and exacerbate headaches and depression, leading to decreased quality of life. This study proposed an appropriate age threshold for recommending evaluation of patients with blepharoptosis among the general population of Korea.

miR-206 Mediates YAP-Induced Cardiac Hypertrophy and Survival.

RATIONALE: In Drosophila, the Hippo signaling pathway negatively regulates organ size by suppressing cell proliferation and survival through the inhibition of Yorkie, a transcriptional cofactor. Yes-associated protein (YAP), the mammalian homolog of Yorkie, promotes cardiomyocyte growth and survival in postnatal hearts. However, the underlying mechanism responsible for the beneficial effect of YAP in cardiomyocytes remains unclear. OBJECTIVES: We investigated whether miR-206, a microRNA known to promote hypertrophy in skeletal muscle, mediates the effect of YAP on promotion of survival and hypertrophy in cardiomyocytes. METHODS AND RESULTS: Microarray analysis indicated that YAP increased miR-206 expression in cardiomyocytes. Increased miR-206 expression induced cardiac hypertrophy and inhibited cell death in cultured cardiomyocytes, similar to that of YAP. Downregulation of endogenous miR-206 in cardiomyocytes attenuated YAP-induced cardiac hypertrophy and survival, suggesting that miR-206 plays a critical role in mediating YAP function. Cardiac-specific overexpression of miR-206 in mice induced hypertrophy and protected the heart from ischemia/reperfusion injury, whereas suppression of miR-206 exacerbated ischemia/reperfusion injury and prevented pressure overload-induced cardiac hypertrophy. miR-206 negatively regulates Forkhead box protein P1 expression in cardiomyocytes and overexpression of Forkhead box protein P1 attenuated miR-206-induced cardiac hypertrophy and survival, suggesting that Forkhead box protein P1 is a functional target of miR-206. CONCLUSIONS: YAP increases the abundance of miR-206, which in turn plays an essential role in mediating hypertrophy and survival by silencing Forkhead box protein P1 in cardiomyocytes.

Structure-activity relationships of amide-phosphonate derivatives as inhibitors of the human soluble epoxide hydrolase.

Structure-activity relationships of amide-phosphonate derivatives as inhibitors of the human soluble epoxide hydrolase (sEH) were investigated. First, a series of alkyl or aryl groups were substituted on the carbon alpha to the phosphonate function in amide compounds to see whether substituted phosphonates can act as a secondary pharmacophore. A tert-butyl group (16) on the alpha carbon was found to yield most potent inhibition on the target enzyme. A 4-50-fold drop in inhibition was induced by other substituents such as aryls, substituted aryls, cycloalkyls, and alkyls. Then, the modification of the O-substituents on the phosphonate function revealed that diethyl groups (16 and 23) were preferable for inhibition to other longer alkyls or substituted alkyls. In amide compounds with the optimized diethylphosphonate moiety and an alkyl substitution such as adamantane (16), tetrahydronaphthalene (31), or adamantanemethane (36), highly potent inhibitions were gained. In addition, the resulting potent amide-phosphonate compounds had reasonable water solubility, suggesting that substituted phosphonates in amide inhibitors are effective for both inhibition potency on the human sEH and water solubility as a secondary pharmacophore.

Discovery of functional elements in 12 Drosophila genomes using evolutionary signatures.

Sequencing of multiple related species followed by comparative genomics analysis constitutes a powerful approach for the systematic understanding of any genome. Here, we use the genomes of 12 Drosophila species for the de novo discovery of functional elements in the fly. Each type of functional element shows characteristic patterns of change, or 'evolutionary signatures', dictated by its precise selective constraints. Such signatures enable recognition of new protein-coding genes and exons, spurious and incorrect gene annotations, and numerous unusual gene structures, including abundant stop-codon readthrough. Similarly, we predict non-protein-coding RNA genes and structures, and new microRNA (miRNA) genes. We provide evidence of miRNA processing and functionality from both hairpin arms and both DNA strands. We identify several classes of pre- and post-transcriptional regulatory motifs, and predict individual motif instances with high confidence. We also study how discovery power scales with the divergence and number of species compared, and we provide general guidelines for comparative studies.

Breast Tissue Reconstruction Using Polycaprolactone Ball Scaffolds in a Partial Mastectomy Pig Model.

BACKGROUND: Breast cancer patients suffer from lowered quality of life (QoL) after surgery. Breast conservancy surgery (BCS) such as partial mastectomy is being practiced and studied as an alternative to solve this problem. This study confirmed breast tissue reconstruction in a pig model by fabricating a 3-dimensional (3D) printed Polycaprolactone spherical scaffold (PCL ball) to fit the tissue resected after partial mastectomy. METHODS: A 3D printed Polycaprolactone spherical scaffold with a structure that can help adipose tissue regeneration was produced using computer-aided design (CAD). A physical property test was conducted for optimization. In order to enhance biocompatibility, collagen coating was applied and a comparative study was conducted for 3 months in a partial mastectomy pig model. RESULTS: In order to identify adipose tissue and fibroglandular tissue, which mainly constitute breast tissue, the degree of adipose tissue and collagen regeneration was confirmed in a pig model after 3 months. As a result, it was confirmed that a lot of adipose tissue was regenerated in the PCL ball, whereas more collagen was regenerated in the collagen-coated Polycaprolactone spherical scaffold (PCL-COL ball). In addition, as a result of confirming the expression levels of TNF-a and IL-6, it was confirmed that PCL ball showed higher levels than PCL-COL ball. CONCLUSION: Through this study, we were able to confirm the regeneration of adipose tissue through a 3-dimensional structure in a pig model. Studies were conducted on medium and large-sized animal models for the final purpose of clinical use and reconstruction of human breast tissue, and the possibility was confirmed.

Celf4 controls mRNA translation underlying synaptic development in the prenatal mammalian neocortex.

Abnormalities in neocortical and synaptic development are linked to neurodevelopmental disorders. However, the molecular and cellular mechanisms governing initial synapse formation in the prenatal neocortex remain poorly understood. Using polysome profiling coupled with snRNAseq on human cortical samples at various fetal phases, we identify human mRNAs, including those encoding synaptic proteins, with finely controlled translation in distinct cell populations of developing frontal neocortices. Examination of murine and human neocortex reveals that the RNA binding protein and translational regulator, CELF4, is expressed in compartments enriched in initial synaptogenesis: the marginal zone and the subplate. We also find that Celf4/CELF4-target mRNAs are encoded by risk genes for adverse neurodevelopmental outcomes translating into synaptic proteins. Surprisingly, deleting Celf4 in the forebrain disrupts the balance of subplate synapses in a sex-specific fashion. This highlights the significance of RNA binding proteins and mRNA translation in evolutionarily advanced synaptic development, potentially contributing to sex differences.

Making sense of mRNA landscapes: Translation control in neurodevelopment.

Like all other parts of the central nervous system, the mammalian neocortex undergoes temporally ordered set of developmental events, including proliferation, differentiation, migration, cellular identity, synaptogenesis, connectivity formation, and plasticity changes. These neurodevelopmental mechanisms have been characterized by studies focused on transcriptional control. Recent findings, however, have shown that the spatiotemporal regulation of post-transcriptional steps like alternative splicing, mRNA traffic/localization, mRNA stability/decay, and finally repression/derepression of protein synthesis (mRNA translation) have become just as central to the neurodevelopment as transcriptional control. A number of dynamic players act post-transcriptionally in the neocortex to regulate these steps, as RNA binding proteins (RBPs), ribosomal proteins (RPs), long non-coding RNAs, and/or microRNA. Remarkably, mutations in these post-transcriptional regulators have been associated with neurodevelopmental, neurodegenerative, inherited, or often co-morbid disorders, such as microcephaly, autism, epilepsy, intellectual disability, white matter diseases, Rett-syndrome like phenotype, spinocerebellar ataxia, and amyotrophic lateral sclerosis. Here, we focus on the current state, advanced methodologies and pitfalls of this exciting and upcoming field of RNA metabolism with vast potential in understanding fundamental neurodevelopmental processes and pathologies. This article is categorized under: Translation > Translation Regulation RNA in Disease and Development > RNA in Disease RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.

Extrinsic Regulators of mRNA Translation in Developing Brain: Story of WNTs.

Extrinsic molecules such as morphogens can regulate timed mRNA translation events in developing neurons. In particular, Wingless-type MMTV integration site family, member 3 (Wnt3), was shown to regulate the translation of Foxp2 mRNA encoding a Forkhead transcription factor P2 in the neocortex. However, the Wnt receptor that possibly mediates these translation events remains unknown. Here, we report Frizzled member 7 (Fzd7) as the Wnt3 receptor that lays downstream in Wnt3-regulated mRNA translation. Fzd7 proteins co-localize with Wnt3 ligands in developing neocortices. In addition, the Fzd7 proteins overlap in layer-specific neuronal subpopulations expressing different transcription factors, Foxp1 and Foxp2. When Fzd7 was silenced, we found decreased Foxp2 protein expression and increased Foxp1 protein expression, respectively. The Fzd7 silencing also disrupted the migration of neocortical glutamatergic neurons. In contrast, Fzd7 overexpression reversed the pattern of migratory defects and Foxp protein expression that we found in the Fzd7 silencing. We further discovered that Fzd7 is required for Wnt3-induced Foxp2 mRNA translation. Surprisingly, we also determined that the Fzd7 suppression of Foxp1 protein expression is not Wnt3 dependent. In conclusion, it is exhibited that the interaction between Wnt3 and Fzd7 regulates neuronal identity and the Fzd7 receptor functions as a downstream factor in ligand Wnt3 signaling for mRNA translation. In particular, the Wnt3-Fzd7 signaling axis determines the deep layer Foxp2-expressing neurons of developing neocortices. Our findings also suggest that Fzd7 controls the balance of the expression for Foxp transcription factors in developing neocortical neurons. These discoveries are presented in our manuscript within a larger framework of this review on the role of extrinsic factors in regulating mRNA translation.

MSL cis-spreading from roX gene up-regulates the neighboring genes.

The male-specific lethal (MSL) complex in Drosophila melanogaster paints the male X chromosome in a manner that is both cis and trans to induce 2-fold hypertranscription of the X chromosome. To characterize the upregulation of gene expression by MSL cis-spreading, we measured the expressional change of neighboring genes by microarray when the genes were bound by MSL complexes that spread from an autosomal roX transgene. Genes within a 200kb region that includes roX transgenes were upregulated concurrently with MSL cis-spreading. Conversely, there was almost no expressional change in genes from other regions. RT-PCR and ChIP analyses confirmed that the approximately 2-fold gene hypertranscription was due to MSL cis-spreading. We also demonstrated that upregulation of the neighboring gene could rescue haplo-insufficient phenotypes of the Minute mutant, such as short bristle, delayed adult eclosion and decreased viability. These results indicate that the hypertranscription by MSL cis-spreading is a general mechanism that occurs in several tissue types. Our molecular and genetic data suggest that cis-spreading of the MSL complex from high-affinity sites including the roX gene results in upregulation of the neighboring genes, which are targets for dosage compensation in the male X chromosome.

Regulation of the catalytic function of topoisomerase II alpha through association with RNA.

Topoisomerase IIalpha interacts with numerous nuclear factors, through which it is engaged in diverse nuclear events such as DNA replication, transcription and the formation or maintenance of heterochromatin. We previously reported that topoisomerase IIalpha interacts with RNA helicase A (RHA), consistent with a recent view that topoisomerases and helicases function together. Intrigued by our observation that the RHA-topoisomerase IIalpha interaction is sensitive to ribonuclease A, we explored whether the RHA-topoisomerase IIalpha interaction can be recapitulated in vitro using purified proteins and a synthetic RNA. This work led us to an unexpected finding that an RNA-binding activity is intrinsically associated with topoisomerase IIalpha. Topoisomerase IIalpha stably interacted with RNA harboring a 3'-hydroxyl group but not with RNA possessing a 3'-phosphate group. When measured in decatenation and relaxation assays, RNA binding influenced the catalytic function of topoisomerase IIalpha to regulate DNA topology. We discuss a possible interaction of topoisomerase IIalpha with the poly(A) tail and G/U-rich 3'-untranslated region (3'-UTR) of mRNA as a key step in transcription termination.

Translational derepression of Elavl4 isoforms at their alternative 5' UTRs determines neuronal development.

Neurodevelopment requires precise regulation of gene expression, including post-transcriptional regulatory events such as alternative splicing and mRNA translation. However, translational regulation of specific isoforms during neurodevelopment and the mechanisms behind it remain unknown. Using RNA-seq analysis of mouse neocortical polysomes, here we report translationally repressed and derepressed mRNA isoforms during neocortical neurogenesis whose orthologs include risk genes for neurodevelopmental disorders. We demonstrate that the translation of distinct mRNA isoforms of the RNA binding protein (RBP), Elavl4, in radial glia progenitors and early neurons depends on its alternative 5' UTRs. Furthermore, 5' UTR-driven Elavl4 isoform-specific translation depends on upstream control by another RBP, Celf1. Celf1 regulation of Elavl4 translation dictates development of glutamatergic neurons. Our findings reveal a dynamic interplay between distinct RBPs and alternative 5' UTRs in neuronal development and underscore the risk of post-transcriptional dysregulation in co-occurring neurodevelopmental disorders.

Longer lifespan in the Rpd3 and Loco signaling results from the reduced catabolism in young age with noncoding RNA.

Downregulation of Rpd3 (histone deacetylase) or Loco (regulator of G-protein signaling protein) extends Drosophila lifespan with higher stress resistance. We found rpd3-downregulated long-lived flies genetically interact with loco-upregulated short-lived flies in stress resistance and lifespan. Gene expression profiles between those flies revealed that they regulate common target genes in metabolic enzymes and signaling pathways, showing an opposite expression pattern in their contrasting lifespans. Functional analyses of more significantly changed genes indicated that the activities of catabolic enzymes and uptake/storage proteins are reduced in long-lived flies with Rpd3 downregulation. This reduced catabolism exhibited from a young age is considered to be necessary for the resultant longer lifespan of the Rpd3- and Loco-downregulated old flies, which mimics the dietary restriction (DR) effect that extends lifespan in the several species. Inversely, those catabolic activities that break down carbohydrates, lipids, and peptides were high in the short lifespan of Loco-upregulated flies. Long noncoding gene, dntRL (CR45923), was also found as a putative target modulated by Rpd3 and Loco for the longevity. Interestingly, this dntRL could affect stress resistance and lifespan, suggesting that the dntRL lncRNA may be involved in the metabolic mechanism of Rpd3 and Loco signaling.

An evolutionarily conserved domain of roX2 RNA is sufficient for induction of H4-Lys16 acetylation on the Drosophila X chromosome.

The male-specific lethal (MSL) complex, which includes two noncoding RNA on X (roX)1 and roX2 RNAs, induces histone H4-Lys16 acetylation for twofold hypertranscription of the male X chromosome in Drosophila melanogaster. To characterize the role of roX RNAs in this process, we have identified evolutionarily conserved functional domains of roX RNAs in several Drosophila species (eight for roX1 and nine for roX2). Despite low homology between them, male-specific expression and X chromosome-specific binding are conserved. Within roX RNAs of all Drosophila species, we found conserved primary sequences, such as GUUNUACG, in the 3' end of both roX1 (three repeats) and roX2 (two repeats). A predicted stem-loop structure of roX2 RNA contains this sequence in the 3' stem region. Six tandem repeats of this stem-loop region (72 nt) of roX2 were enough for targeting the MSL complex and inducing H4-Lys16 acetylation on the X chromosome without other parts of roX2 RNA, suggesting that roX RNAs might play important roles in regulating enzymatic activity of the MSL complex.

Stress resistance and lifespan enhanced by downregulation of antimicrobial peptide genes in the Imd pathway.

Biological behaviors and longevity of ectothermic animals are remarkably influenced by ambient temperature. Development at 18°C significantly enhances the stress resistance of adult flies with more accumulation of nutrients (especially fat) in the body than development at 25°C. Gene expression analysis between the flies developed at 18°C and 25°C revealed that the Immune deficiency (Imd) pathway, including the downstream antimicrobial peptides (AMPs), is downregulated in the flies developed at 18°C. When hypomorphic imd mutant flies with reduced AMP expressions were developed at 25°C, they showed induced stress resistance with higher fat content in the body similar to the wild-type flies developed at 18°C. However, severe hypomorphic imd mutants could not enhance stress resistance due to the downregulation of another downstream JNK pathway that expresses stress tolerance genes. Interestingly, the downregulation of AMP genes, itself, extended lifespan with increased stress resistance. Especially, fat body-specific downregulation of Imd AMP genes exhibited a longer lifespan with higher heat resistance. The fat body is known to function in metabolic homeostasis, stress tolerance, growth, and longevity in Drosophila. Here, we provide the first evidence that mild downregulation of the Imd pathway with AMP genes increases fat content, stress resistance, and lifespan in adult flies.

Appropriate Amount of Regular Exercise Is Associated with a Reduced Mortality Risk.

PURPOSE: This study aimed at investigating whether there is a continuous dose-response relationship between the amount of physical activity (PA) and longevity benefit. METHODS: We evaluated the records of 23,257,723 Koreans age ≥20 yr who had undergone one biennial medical evaluation by the National Health Insurance Corporation. Participants with ≥20 min of vigorous or ≥30 min of moderate PA or walking were stratified into four groups: 0 d·wk; 1-3 d·wk; 4 to 5 d·wk; and 6-7 d·wk. After calculating total metabolic equivalent task-hours per week (MET·h·wk), we created eight categories of MET-hours per week (0, 0.1-4.9, 5.0-9.9, 10.0-14.9, 15.0-19.9, 20.0-24.9, 25.0-29.9, and ≥30.0). Multivariate Cox proportional hazard analyses were performed. RESULTS: A reverse J-shaped risk curve was observed, with the lowest mortality risk in the participants exercising 4 to 5 d·wk (reference). Participants who did not exercise at all and those who exercised with a PA frequency of 1 to 3 d·wk or 6 to 7 d·wk showed a significantly increased mortality risk compared with the reference group. When we repeated the Cox analysis among the 8 MET·h·wk categories with the participants reporting 20.0 to 24.9 MET·h·wk of PA as the reference group, we found that those with physical inactivity and 25.0-29.9 or ≥30.0 MET·h·wk of PA showed a higher mortality risk than the reference group. These relationships were persistently observed after adjustment for confounders. CONCLUSIONS: An appropriate amount of regular exercise in each specific type of PA was associated with the lowest risk of mortality. The inactive participants showed an increased mortality risk, and daily PA did not show any additional benefit in the mortality risk.

Gender-specific relationship between alcohol consumption and injury in the South Korean adults: A nationwide cross-sectional study.

Alcohol-related injuries have been concerned worldwide. However, there have been no large cross-sectional epidemiologic studies. The aim of this study was to investigate the association between alcohol and the prevalence of injury according to gender in a representative sample of the South Korean population. This cross-sectional study was based on data obtained in the Korea National Health and Nutrition Examination Survey from 2010 to 2012. In total, 15,249 Korean adults (7128 men and 8112 women) aged 19 years or older were enrolled. Injury was defined as the incidence of an injury or intoxication within the year before completing the survey questionnaire. Univariate and multiple logistic regression analyses were conducted to analyze the relationship between alcohol consumption and the prevalence of injury. Heavy alcohol consumption and high-risk drinking were associated with a higher prevalence of injury in women (adjusted odds ratio [aOR] and corresponding 95% confidence interval [CI]: 2.48 [1.321, 4.656], 1.816 [1.136, 2.929], respectively), and Alcohol Use Disorders Identification Test (AUDIT) scores ≥20 were associated with a higher prevalence of injury in both men and women (aOR and 95% CI: 1.425 [1.004, 2.024] and 3.71 [2.067, 6.66], respectively). According to the AUDIT scores results, women who were injured reported significantly more high-risk drinking behaviors per month compared with those who were not injured. Gender disparities in the relationship between alcohol and the prevalence of injury were found. Indeed, future research using a prospective design should examine the causal relationship between alcohol consumption and the prevalence injury according to gender to confirm that alcohol is a risk factor for injury and to identify the possible mechanisms underlying this phenomenon.

Socioeconomic Disparities in the Prevalence of Blepharoptosis in the South Korean Adult Population Based on a Nationwide Cross-Sectional Study.

PURPOSE: We investigated the association between socioeconomic status (SES) and the prevalence of blepharoptosis in a representative South Korean population. METHODS: This cross-sectional study was based on data obtained in the Korea National Health and Nutrition Examination Survey from 2010 to 2012. In total, 17,178 Korean adults (7,261 men and 9,917 women) aged 19 years or older were enrolled. Blepharoptosis was defined as a marginal reflex distance 1 (MDR 1) lower than 2 mm. Household income and education level were used as indicators of SES. Univariate and multiple logistic regression analyses were conducted to analyze the relationship between SES and the prevalence of blepharoptosis. RESULTS: Household income was inversely associated with the prevalence of blepharoptosis in women [adjusted odds ratio (aOR) and corresponding 95% confidence interval (95% CI) was 1.894 (1.336, 2.685)], and educational level was inversely associated with blepharoptosis in both men and women [aORs and 95% CIs were 1.572 (1.113, 2.219) and 1.973 (1.153, 3.376), respectively]. After adjusting for household income and educational level, low SES was associated with a high prevalence of blepharoptosis in women only. CONCLUSIONS: Socioeconomic disparities in the prevalence of blepharoptosis were found among women. Indeed, future research using a prospective design to determine the causal relationship between SES and blepharoptosis may identify SES as a risk factor for this condition.

Suicidal ideation among postmenopausal women on hormone replacement therapy: The Korean National Health and Nutrition Examination Survey (KNHANES V) from 2010 to 2012.

BACKGROUND: Suicide is a major public health problem around the world. Some studies have found that hormone replacement therapy (HRT) is associated with depression in postmenopausal women. Depression is a well-known risk factor for suicide; therefore, we investigated the relationship between HRT and suicidal ideation in postmenopausal Korean women. METHODS: We included 2286 postmenopausal women with or without HRT from the Korean National Health and Nutrition Examination Survey 2010-2012. The use and duration of HRT and mental health status, including stress, depressive mood, and suicidal ideation and attempts, were assessed by self-report questionnaires. RESULTS: The proportion of participants with depressive mood and suicidal ideation was higher in the HRT group than the non-HRT group (all p values<0.05). As the duration of HRT increased, the percentage of participants with suicidal ideation increased (p for trend=0.006). After adjusting for all covariates, the odds ratio (95% confidence intervals) for suicidal ideation was 1.742 (1.223-2.482) in the women with HRT, compared to women without HRT. HRT duration longer than 10 years was associated with suicidal ideation (odds ratio=2.089 and 95% confidence intervals=1.069-4.084). LIMITATIONS: The cross-sectional design, a possibility of incorrect answer about menopausal status, and no assessment of the type of HRT are the main limitations of this study. CONCLUSION: Postmenopausal women receiving HRT, especially for more than 10 years, showed increased suicidal ideation compared with postmenopausal women without HRT. Physicians should pay attention to mood symptoms and suicidal ideation in postmenopausal women with HRT.

Variable splicing of non-coding roX2 RNAs influences targeting of MSL dosage compensation complexes in Drosophila.

The non-coding roX1 and roX2 RNAs are components of the MSL dosage compensation complex in Drosophila. We found that multiple species of roX2 RNA are produced by alternative splicing, with one major and at least 20 different minor forms associated with MSL proteins. The alternative forms are generated by variable usage of multiple 5' and 3' splice sites between two common exons. This alternative splicing is evolutionarily conserved in several distant Drosophila species in spite of differences in primary sequences. Transgenic constructs expressing individual major or minor D. melanogaster roX2 species display low steady-state levels of roX2 RNA, weak accumulation of MSL complex on the X chromosome, and low rescue of male-specific roX(-) lethality. Increased expression of individual roX2 forms using the constitutive Hsp83 promoter results in increased transgenic rescue of roX(-) mutant male flies. However, although males survive they are delayed in their development. In addition, MSL complexes still show low affinity for the X chromosome and abnormal accumulation at the transgenic site of synthesis of the individual roX2 alternative splice form. Taken together, these results suggest an important role for roX2 RNA splicing in optimal MSL complex assembly or function.