ABSTRACT
The muscleblind-like (MBNL) family of proteins are key developmental regulators of alternative splicing. Sequestration of MBNL proteins by expanded CUG/CCUG repeat RNA transcripts is a major pathogenic mechanism in the neuromuscular disorder myotonic dystrophy (DM). MBNL1 contains four zinc finger (ZF) motifs that form two tandem RNA binding domains (ZF1-2 and ZF3-4) which each bind YGCY RNA motifs. In an effort to determine the differences in function between these domains, we designed and characterized synthetic MBNL proteins with duplicate ZF1-2 or ZF3-4 domains, referred to as MBNL-AA and MBNL-BB, respectively. Analysis of splicing regulation revealed that MBNL-AA had up to 5-fold increased splicing activity while MBNL-BB had 4-fold decreased activity compared to a MBNL protein with the canonical arrangement of zinc finger domains. RNA binding analysis revealed that the variations in splicing activity are due to differences in RNA binding specificities between the two ZF domains rather than binding affinity. Our findings indicate that ZF1-2 drives splicing regulation via recognition of YGCY RNA motifs while ZF3-4 acts as a general RNA binding domain. Our studies suggest that synthetic MBNL proteins with improved or altered splicing activity have the potential to be used as both tools for investigating splicing regulation and protein therapeutics for DM and other microsatellite diseases.
Subject(s)
Alternative Splicing , Protein Engineering/methods , RNA Precursors/metabolism , RNA-Binding Proteins/metabolism , RNA/metabolism , Base Sequence , Binding Sites/genetics , HEK293 Cells , HeLa Cells , Humans , Myotonic Dystrophy/genetics , Myotonic Dystrophy/therapy , Nucleotide Motifs/genetics , RNA/genetics , RNA Precursors/genetics , RNA-Binding Motifs/genetics , RNA-Binding Proteins/genetics , Zinc Fingers/geneticsABSTRACT
Cardiac patients' beliefs about the causes of their illness may influence their receptivity to psychosocial interventions. The purpose of this study was to determine whether depression or anxiety influence patients' attributions about the causes of their heart disease. The primary hypothesis was that depressed or anxious patients are more likely to endorse negative emotions as among the causes of their heart disease than are patients who are not depressed or anxious. Sixty-nine patients with documented ischemic heart disease recruited from an exercise stress testing laboratory completed the Beck Depression and Anxiety Inventories and a heart disease attribution checklist. Univariate analyses confirmed that patients who are depressed or anxious are more likely than other patients to endorse negative emotions as causes of their heart disease. Anxiety but not depression was retained as an independent predictor of negative emotion attributions in a logistic regression analysis. We conclude that mood state influences cardiac patients' beliefs about the causes of their heart disease.
Subject(s)
Anxiety/psychology , Depression/psychology , Heart Diseases/etiology , Aged , Culture , Female , Humans , Male , Middle Aged , Psychology , Surveys and QuestionnairesABSTRACT
OBJECTIVE: Depression is a common problem in patients with obstructive sleep apnea. The objective of this study was to examine whether depression is independently associated with lower self-reported sleep quality in patients with obstructive sleep apnea (OSA), after controlling for polysomnographic measures of sleep. METHODS: The sample comprised 135 patients who had been referred to a university teaching hospital's multidisciplinary sleep medicine center for polysomnographic evaluation of OSA. The median age of the subjects was 45 (mean age, 46 years) 55% were female, 69% were white, 31% were black, and their mean body mass index was 37.9 +/- 11.2 kg/m2. Self-reported sleep quality during the past 2 weeks was assessed by the insomnia severity index. Polygraphic measures of sleep quality included the respiratory disturbance index, sleep onset latency, arousals for no apparent reason, sleep efficiency, and periodic leg movements associated with arousal. Depressive symptoms were assessed by the Beck Depression Inventory. RESULTS: None of the polygraphic measures of sleep quality was related to self-reported sleep quality or depression. Oxygen desaturation was correlated with self-reported sleep quality (r = 0.21, p =.02). Depression correlated with self-reported sleep quality (r = 0.55, p <.0001). In a multiple regression analysis, depression remained a significant predictor of self-reported sleep quality after controlling for all of the polysomnographic measures of sleep quality (F = 9.65, partial r2 = 0.28 p =.0001). CONCLUSION: Depression is a better predictor of self-reported sleep quality than are polysomnographic measures of sleep in patients with OSA.
