Deletion of translin (Tsn) induces robust adiposity and hepatic steatosis without impairing glucose tolerance.

OBJECTIVE: Translin knockout (KO) mice display robust adiposity. Recent studies indicate that translin and its partner protein, trax, regulate the microRNA and ATM kinase signaling pathways, both of which have been implicated in regulating metabolism. In the course of characterizing the metabolic profile of these mice, we found that they display normal glucose tolerance despite their elevated adiposity. Accordingly, we investigated why translin KO mice display this paradoxical phenotype. METHODS: To help distinguish between the metabolic effects of increased adiposity and those of translin deletion per se, we compared three groups: (1) wild-type (WT), (2) translin KO mice on a standard chow diet, and (3) adiposity-matched WT mice that were placed on a high-fat diet until they matched translin KO adiposity levels. All groups were scanned to determine their body composition and tested to evaluate their glucose and insulin tolerance. Plasma, hepatic, and adipose tissue samples were collected and used for histological and molecular analyses. RESULTS: Translin KO mice show normal glucose tolerance whereas adiposity-matched WT mice, placed on a high-fat diet, do not. In addition, translin KO mice display prominent hepatic steatosis that is more severe than that of adiposity-matched WT mice. Unlike adiposity-matched WT mice, translin KO mice display three key features that have been shown to reduce susceptibility to insulin resistance: increased accumulation of subcutaneous fat, increased levels of circulating adiponectin, and decreased Tnfα expression in hepatic and adipose tissue. CONCLUSIONS: The ability of translin KO mice to retain normal glucose tolerance in the face of marked adipose tissue expansion may be due to the three protective factors noted above. Further studies aimed at defining the molecular bases for this combination of protective phenotypes may yield new approaches to limit the adverse metabolic consequences of obesity.

Deletion of the microRNA-degrading nuclease, translin/trax, prevents pathogenic vascular stiffness.

Vascular stiffness plays a key role in the pathogenesis of hypertension. Recent studies indicate that the age-associated reduction in miR-181b levels in vascular smooth muscle cells (VSMCs) contributes to increased vascular stiffness. As these findings suggest that inhibiting degradation of miR-181b might prevent vascular stiffening, we have assessed whether the microRNA-degrading translin/trax (TN/TX) complex mediates degradation of miR-181b in the aorta.We found that TN-/- mice display elevated levels of miR-181b expression in the aorta. Therefore, we tested whether TN deletion prevents vascular stiffening in a mouse model of hypertension, induced by chronic high-salt intake (4%NaCl in drinking water for 3 wk; HSW). TN-/- mice subjected to HSW stress do not show increased vascular stiffness, as monitored by pulse wave velocity and tensile testing. The protective effect of TN deletion in the HSW paradigm appears to be mediated by its ability to increase miR-181b in the aorta since HSW decreases levels of miR-181b in WT mice, but not in TN KO mice. We demonstrate for the first time that interfering with microRNA degradation can have a beneficial impact on the vascular system and identify the microRNA-degrading TN/TX RNase complex as a potential therapeutic target in combatting vascular stiffness.NEW & NOTEWORTHY While the biogenesis and mechanism of action of mature microRNA are well understood, much less is known about the regulation of microRNA via degradation. Recent studies have identified the protein complex, translin(TN)/trax(TX), as a microRNA-degrading enzyme. Here, we demonstrate that TN/TX is expressed in vascular smooth muscle cells. Additionally, deletion of the TN/TX complex selectively increases aortic miR-181b and prevents increased vascular stiffness caused by ingestion of high-salt water. To our knowledge, this is first report describing the role of a microRNA RNAse in cardiovascular biology or pathobiology.

Trax: A versatile signaling protein plays key roles in synaptic plasticity and DNA repair.

Translin-associated protein X (TSNAX), also called trax, was first identified as a protein that interacts with translin. Subsequent studies demonstrated that these proteins form a heteromeric RNase complex that mediates degradation of microRNAs, a pivotal finding that has stimulated interest in understanding the role of translin and trax in cell signaling. Recent studies addressing this question have revealed that trax plays key roles in both synaptic plasticity and DNA repair signaling pathways. In the context of synaptic plasticity, trax works together with its partner protein, translin, to degrade a subset of microRNAs. Activation of the translin/trax RNase complex reverses microRNA-mediated translational silencing to trigger dendritic protein synthesis critical for synaptic plasticity. In the context of DNA repair, trax binds to and activates ATM, a central component of the double-stranded DNA repair process. Thus, these studies focus attention on trax as a critical signaling protein that interacts with multiple partners to impact diverse signaling pathways. To stimulate interest in deciphering the multifaceted role of trax in cell signaling, we summarize the current understanding of trax biology and highlight gaps in our knowledge about this protean protein.

Rapid reversal of translational silencing: Emerging role of microRNA degradation pathways in neuronal plasticity.

As microRNAs silence translation, rapid reversal of this process has emerged as an attractive mechanism for driving de novo protein synthesis mediating neuronal plasticity. Herein, we summarize recent studies identifying neuronal stimuli that trigger rapid decreases in microRNA levels and reverse translational silencing of plasticity transcripts. Although these findings indicate that neuronal stimulation elicits rapid degradation of selected microRNAs, we are only beginning to decipher the molecular pathways involved. Accordingly, we present an overview of several molecular pathways implicated in mediating microRNA degradation: Lin-28, translin/trax, and MCPIP1. As these degradation pathways target distinct subsets of microRNAs, they enable neurons to reverse silencing rapidly, yet selectively.

A pilot randomized trial of levator injections versus physical therapy for treatment of pelvic floor myalgia and sexual pain.

INTRODUCTION AND HYPOTHESIS: Our aim was to determine the effects of pelvic floor physical therapy (PT) and levator-directed trigger-point injections (LTPI) on sexual function and levator-related pelvic pain. STUDY DESIGN: A randomized trial among women with pelvic floor myalgia (PFM) was performed wherein participants received either PT or LTPI. Pain was assessed and 1 month posttreatment completion. Levator-based pain was assessed using a numeric rating scale (NRS) and the Patient Global Impression of Improvement (PGI-I) scale. Sexual function was assessed using the Female Sexual Function Index (FSFI). RESULTS: Twenty-nine women completed the study (17 had PT, 12 had LTPI). Both groups reported reduction in vaginal pain: mean NRS change from baseline of 4.47 [standard deviation (SD) 2.12) for PT and 4.67 (SD 1.72) for LTPI (p = 0.8)]. A >50 % improvement in NRS was documented among 59 % of women receiving PT and 58 % receiving LTPI (p = 1.0). Consistent with NRS scores, mean PGI-I score was 2.50 (SD 1.17) for PT and 2.17 (SD 1.01) for LTPI (p = 0.5). Mean change in FSFI favored PT [PT +8.87 (SD 5.60), LTPI +4.00 (SD 5.24), p = 0.04], reflecting improvement in the sexual pain domain favoring PT (p = 0.02). However, the time in weeks to effect improvement favored LTPI if controlling for the degree of change in NRS (p = 0.01) and FSFI (p = 0.01). CONCLUSIONS: Vaginal myalgia and sex-related pain improved with pelvic floor PT and LTPI. Time-to-effect improvement and significance of therapy are dependent on treatment type.

Adenosine A2A Receptor Regulates microRNA-181b Expression in Aorta: Therapeutic Implications for Large-Artery Stiffness.

Background The identification of large-artery stiffness as a major, independent risk factor for cardiovascular disease-associated morbidity and death has focused attention on identifying therapeutic strategies to combat this disorder. Genetic manipulations that delete or inactivate the translin/trax microRNA-degrading enzyme confer protection against aortic stiffness induced by chronic ingestion of high-salt water (4%NaCl in drinking water for 3 weeks) or associated with aging. Therefore, there is heightened interest in identifying interventions capable of inhibiting translin/trax RNase activity, as these may have therapeutic efficacy in large-artery stiffness. Methods and Results Activation of neuronal adenosine A2A receptors (A2ARs) triggers dissociation of trax from its C-terminus. As A2ARs are expressed by vascular smooth muscle cells (VSMCs), we investigated whether stimulation of A2AR on vascular smooth muscle cells promotes the association of translin with trax and, thereby increases translin/trax complex activity. We found that treatment of A7r5 cells with the A2AR agonist CGS21680 leads to increased association of trax with translin. Furthermore, this treatment decreases levels of pre-microRNA-181b, a target of translin/trax, and those of its downstream product, mature microRNA-181b. To check whether A2AR activation might contribute to high-salt water-induced aortic stiffening, we assessed the impact of daily treatment with the selective A2AR antagonist SCH58261 in this paradigm. We found that this treatment blocked aortic stiffening induced by high-salt water. Further, we confirmed that the age-associated decline in aortic pre-microRNA-181b/microRNA-181b levels observed in mice also occurs in humans. Conclusions These findings suggest that further studies are warranted to evaluate whether blockade of A2ARs may have therapeutic potential in treating large-artery stiffness.

Writing an effective and supportive recommendation letter.

Writing recommendation letters on behalf of students and other early-career researchers is an important mentoring task within academia. An effective recommendation letter describes key candidate qualities such as academic achievements, extracurricular activities, outstanding personality traits, participation in and dedication to a particular discipline, and the mentor's confidence in the candidate's abilities. In this Words of Advice, we provide guidance to researchers on composing constructive and supportive recommendation letters, including tips for structuring and providing specific and effective examples, while maintaining a balance in language and avoiding potential biases.

Building and sustaining mentor interactions as a mentee.

Mentorship is experience and/or knowledge-based guidance. Mentors support, sponsor and advocate for mentees. Having one or more mentors when you seek advice can significantly influence and improve your research endeavours, well-being and career development. Positive mentee-mentor relationships are vital for maintaining work-life balance and success in careers. Early-career researchers (ECRs), in particular, can benefit from mentorship to navigate challenges in academic and nonacademic life and careers. Yet, strategies for selecting mentors and maintaining interactions with them are often underdiscussed within research environments. In this Words of Advice, we provide recommendations for ECRs to seek and manage mentorship interactions. Our article draws from our experiences as ECRs and published work, to provide suggestions for mentees to proactively promote beneficial mentorship interactions. The recommended practices highlight the importance of identifying mentorship needs, planning and selecting multiple and diverse mentors, setting goals, and maintaining constructive, and mutually beneficial working relationships with mentors.

Trends in inpatient urinary incontinence surgery in the USA, 1998-2007.

INTRODUCTION AND HYPOTHESIS: This study was conducted to assess national rates in stress urinary incontinence (SUI) surgery in the USA from 1998 to 2007. METHODS: We utilized the 1998-2007 Nationwide Inpatient Sample and assessed women aged 20 years and older who underwent SUI surgery based on the International Classification of Diseases, 9th Revision (ICD-9) procedure and diagnosis codes. RESULTS: The total number of SUI surgeries performed during this 10-year period was 759,821. The annual number of procedures increased from 37,953 in 1998 to 94,910 in 2007. The type of SUI surgery performed also changed (p < 0.001). In 1998, retropubic suspensions represented 52.3%, decreasing to 13.8% in 2007. "Other repair of SUI" (ICD-9 59.79) comprised 22.4% in 1998, increasing to 75.2% in 2007, likely representing midurethral slings. CONCLUSIONS: The total number and incidence rates of SUI surgeries have increased from 1998 to 2007. The type of SUI surgery performed has also changed significantly, likely secondary to adoption of midurethral slings.

Elevated body fat increases amphetamine accumulation in brain: evidence from genetic and diet-induced forms of adiposity.

Despite the high prevalence of obesity, little is known about its potential impact on the pharmacokinetics of psychotropic drugs. In the course of investigating the role of the microRNA system on neuronal signaling, we found that mice lacking the translin/trax microRNA-degrading enzyme display an exaggerated locomotor response to amphetamine. As these mice display robust adiposity in the context of normal body weight, we checked whether this phenotype might reflect elevated brain levels of amphetamine. To assess this hypothesis, we compared plasma and brain amphetamine levels of wild type and Tsn KO mice. Furthermore, we checked the effect of diet-induced increases in adiposity on plasma and brain amphetamine levels in wild type mice. Brain amphetamine levels were higher in Tsn KO mice than in wild type littermates and correlated with adiposity. Analysis of the effect of diet-induced increases in adiposity in wild type mice on brain amphetamine levels also demonstrated that brain amphetamine levels correlate with adiposity. Increased adiposity displayed by Tsn KO mice or by wild type mice fed a high-fat diet correlates with elevated brain amphetamine levels. As amphetamine and its analogues are widely used to treat attention deficit disorder, which is associated with obesity, further studies are warranted to assess the impact of adiposity on amphetamine levels in these patients.

Degradation of Premature-miR-181b by the Translin/Trax RNase Increases Vascular Smooth Muscle Cell Stiffness.

[Figure: see text].

Vaginal hysterectomy for the prolapsed uterus.

Although most gynecologists are comfortable performing vaginal hysterectomy in the patient without significant uterovaginal prolapse, vaginal hysterectomy for the prolapsed uterus poses unique challenges and requires an increased awareness of deviations in pelvic anatomy that may result. This review article discusses the background of vaginal hysterectomy performed for uterovaginal prolapse, the pathophysiology of uterovaginal prolapse, preoperative assessment of the patient with uterovaginal prolapse, surgical technique, ureteral anatomy, techniques to avoid injury to the ureter at the time of vaginal hysterectomy for uterovaginal prolapse, and other relevant considerations.

Genetic inactivation of the translin/trax microRNA-degrading enzyme phenocopies the robust adiposity induced by Translin (Tsn) deletion.

OBJECTIVE: Deletion of Translin (Tsn) from mice induces an unusual metabolic profile characterized by robust adiposity, normal body weight and glucose tolerance. Translin (TN) protein and its partner, trax (TX), form the TN/TX microRNA-degrading enzyme. Since the microRNA system plays a prominent role in regulating metabolism, we reasoned that the metabolic profile displayed by Tsn KO mice might reflect dysregulation of microRNA signaling. METHODS: To test this hypothesis, we inserted a mutation, E126A, in Tsnax, the gene encoding TX, that abolishes the microRNA-degrading enzymatic activity of the TN/TX complex. In addition, to help define the cell types that drive the adiposity phenotype, we have also generated mice with floxed alleles of Tsn or Tsnax. RESULTS: Introduction of the E126A mutation in Tsnax does not impair expression of TN or TX proteins or their co-precipitation. Furthermore, these mice display selective increases in microRNAs that match those induced by Tsn deletion, confirming that this mutation in Tsnax inactivates the microRNA-degrading activity of the TN/TX complex. Mice homozygous for the Tsnax (E126A) mutation display a metabolic profile that closely mimics that of Tsn KO mice. Selective deletion of Tsn or Tsnax from either adipocytes or hepatocytes, two candidate cell types, does not phenocopy the elevated adiposity displayed by mice with constitutive Tsn deletion or the Tsnax (E126A) mutation. Furthermore, global, conditional deletion of Tsn in adulthood does not elicit increased adiposity. CONCLUSION: Taken together, these findings indicate that inactivation of the TN/TX microRNA-degrading enzyme during development is necessary to drive the robust adiposity displayed by Tsn KO mice.

Hospital-based surveillance of invasive pneumococcal disease among young children in urban Nepal.

BACKGROUND: Streptococcus pneumoniae is a leading cause of pneumonia and meningitis in young children. Before implementation of the pneumococcal conjugate vaccine in developing countries, there is an urgent need to provide regional epidemiological data on pneumococcal disease. The aims of this study were to determine the prevalence and serotype distribution of invasive pneumococcal disease among young children hospitalized in urban Nepal. METHODS: Children aged 2 months to 5 years who were admitted to Patan Hospital, Kathmandu, with fever and/or suspected pneumonia, meningitis, or bacteremia were recruited. Blood culture specimens were collected from all participants. In cases of suspected meningitis, cerebrospinal fluid specimens were cultured and were tested for S. pneumoniae antigen. RESULTS: A total of 885 children were recruited during the 21-month study period. Of these, 76 (9%) had meningitis and 498 (56%) had pneumonia, on the basis of clinical criteria. Radiographically confirmed pneumonia occurred in 354 (40%), and probable or definite meningitis occurred in 47 (5%). S. pneumoniae was isolated in specimens from 17 (2%) of the children. Serotypes 1 and 12A were isolated most frequently, and only 1 of 17 isolates had a serotype contained in the currently available 7-valent pneumococcal conjugate vaccine. CONCLUSIONS: More than 60% of children aged <5 years who were admitted with fever and/or suspected invasive bacterial disease in urban Nepal had the clinical syndromes of meningitis and/or pneumonia. A new generation of pneumococcal vaccines that prevent infection with a broader range of serotypes may be necessary to most effectively control pneumococcal disease in young children in Kathmandu.

Multiple Pathways Mediate MicroRNA Degradation: Focus on the Translin/Trax RNase Complex.

The discovery of the microRNA system has revolutionized our understanding of translational control. Furthermore, growing appreciation of the pivotal role that de novo translation plays in activity-dependent synaptic plasticity has fueled interest among neuroscientists in deciphering how the microRNA system impacts neuronal signaling and the pathophysiology of neuropsychiatric disorders. Although we have a general understanding of how the microRNA system operates, many key questions remain. In particular, the biosynthesis of microRNAs and their role in translational silencing are fairly well understood. However, much less is known about how microRNAs are degraded and silencing is reversed, crucial aspects of microRNA signaling. In contrast to microRNA synthesis which is mediated almost exclusively by a single pathway that culminates in Dicer, recent studies indicate that there are multiple pathways of microRNA degradation that target different subpopulations of microRNAs. While the Lin-28 pathway of microRNA degradation has been investigated extensively, the translin/trax RNase complex has emerged recently as another pathway mediating microRNA degradation. Accordingly, we summarize herein key features of the translin/trax RNase complex as well as important gaps in our understanding of its regulation and function that are the focus of ongoing studies.

Physical activity and urinary incontinence among healthy, older women.

OBJECTIVE: To examine the association between physical activity and risk of developing urinary incontinence (UI). METHODS: Prospective analysis from the Nurses' Health Study of women aged 54-79 years. Physical activity was reported in 1986 and biennially afterward. To determine stable, long-term activity levels, data were averaged across all questionnaires (bottom quintile: 6.2 metabolic equivalent task hours per week or less; top quintile: more than 28.6 metabolic equivalent task hours per week). From 2000 to 2002, 2,355 cases of incident UI were identified using self-reports of leaking urine. Type of incontinence was determined from questions regarding the circumstances during which leaking occurred. We estimated adjusted odds ratios (ORs) of developing incontinence across quintiles of physical activity levels using logistic regression, controlling for numerous potential confounding factors. RESULTS: Increasing levels of total physical activity were significantly associated with a reduced risk of UI (top versus bottom quintile of metabolic equivalent task hours per week, OR 0.81, 95% confidence interval [CI] 0.71-0.93; P for trend across quintiles <.01). Walking, which constituted approximately half of total physical activity among our participants, was related to 26% lower risk of developing UI (top versus bottom quintile, OR 0.74, 95% CI 0.63-0.88; P for trend across quintiles <.01). Specifically, total physical activity and walking were associated with a significant reduction in stress UI (physical activity: P for trend =.01; walking: P for trend =.01), but neither was related to incidence of urge UI (P for trend =.8 and P for trend =.3, respectively). CONCLUSION: Physical activity was associated with a significant reduction in UI. Results appeared somewhat stronger for stress UI than urge UI. LEVEL OF EVIDENCE: II.

Racial characteristics of women undergoing surgery for pelvic organ prolapse in the United States.

OBJECTIVE: This study was undertaken to compare the prevalence, demographics, and complications of pelvic organ prolapse surgery across races in the United States. STUDY DESIGN: Data from the 2003 National Census and the 2003 National Hospital Discharge Survey were used to determine rates of prolapse surgery, demographic characteristics, morbidity, and mortality across races. RESULTS: In 2003, 199,698 women underwent prolapse surgery. Rates of prolapse surgery per 10,000 women were 14.8, 5.6, and 8.7 in women of white, black, and other races. By geographic region, surgical rates per 10,000 white vs black women differed most in the West (16.0 vs 0.8). Of black women, 27% were on public assistance, compared with 5.9% and 9.6% women of white and other races. Complications occurred in 19.4%, 34.1%, and 27.4% of women of white, black, other races. Mortality was uncommon for all races. CONCLUSION: Racial disparities between white and black women undergoing prolapse surgery appear to exist.

Prevalence and Surgical Outcomes of Macular Hole in Eyes with Age-Related Macular Degeneration.

PURPOSE: To report the prevalence and surgical outcomes of macular holes (MHs) in eyes with age-related macular degeneration (AMD). DESIGN: Interventional, retrospective, consecutive case series. PARTICIPANTS: Patients with MH and concurrent non-neovascular (NNV) or neovascular (NV) AMD. METHODS: The records of 27 912 patients diagnosed with AMD between 2009 and 2014 at Associated Retinal Consultants were reviewed. Demographic data, visual acuity (VA), funduscopic examination, and optical coherence tomography were reviewed in those with a concurrent diagnosis of MH. MAIN OUTCOME MEASURES: The VA and MH closure status. RESULTS: A total of 15 196 patients with NNV and 12 716 patients with NV AMD were identified. A total of 199 eyes (0.7%) had MHs (160 NNV [1.1%]; 39 NV [0.3%]). Mean time to diagnosis of MH after the initial visit was 11.2 months (7.1 NNV; 24.8 NV). A total of 127 eyes underwent surgical repair (106 NNV; 21 NV). The final closure rate in those who underwent vitrectomy was 89.8% (91.5% NNV; 81.0% NV) and 25.0% in those who were observed (18.5% NNV, P < 0.0001; 44.4% NV, P = 0.02). Preoperative logarithm of the minimum angle of resolution VAs in NNV and NV AMD was 0.8±0.4 and 0.8±0.5, respectively, and final VA was 0.6±0.5 (P < 0.001) and 0.9±0.6 (P = 0.52), respectively. Mean follow-up time was 5.0 years. CONCLUSIONS: The prevalence of MH was higher in eyes with NNV AMD than in those with NV AMD. The surgical closure rate was comparable in both groups, but VA improvement reached statistical significance only in the NNV AMD group.