Multi-level regulation of myotubularin-related protein-2 phosphatase activity by myotubularin-related protein-13/set-binding factor-2

Mutations in myotubularin-related protein-2 (MTMR2) or MTMR13/set-binding factor-2 (SBF2) genes are responsible for the severe autosomal recessive hereditary neuropathies, Charcot-Marie-Tooth disease (CMT) types 4B1 and 4B2, both characterized by reduced nerve conduction velocities, focally folded myelin sheaths and demyelination. MTMRs form a large family of conserved dual-specific phosphatases with enzymatically active and inactive members. We show that homodimeric active Mtmr2 interacts with homodimeric inactive Sbf2 in a tetrameric complex. This association dramatically increases the enzymatic activity of the complexed Mtmr2 towards phosphatidylinositol 3-phosphate and phosphatidylinositol 3,5-bisphosphate. Mtmr2 and Sbf2 are considerably, but not completely, co-localized in the cellular cytoplasm. On membranes of large vesicles formed under hypo-osmotic conditions, Sbf2 favorably competes with Mtmr2 for binding sites. Our data are consistent with a model suggesting that, at a given cellular location, Mtmr2 phosphatase activity is highly regulated, being high in the Mtmr2/Sbf2 complex, moderate if Mtmr2 is not associated with Sbf2 or functionally blocked by competition through Sbf2 for membrane-binding site

Mtmr13/Sbf2-deficient mice: an animal model for CMT4B2

Charcot-Marie-Tooth (CMT) disease denotes a large group of genetically heterogeneous hereditary motor and sensory neuropathies and ranks among the most common inherited neurological disorders. Mutations in the Myotubularin-Related Protein-2 (MTMR2) or MTMR13/Set-Binding Factor-2 (SBF2) genes are associated with the autosomal recessive disease subtypes CMT4B1 or CMT4B2. Both forms of CMT share similar features including a demyelinating neuropathy associated with reduced nerve conduction velocity (NCV) and focally folded myelin. Consistent with a common disease mechanism, the homodimeric MTMR2 acts as a phosphoinositide D3-phosphatase with phosphatidylinositol (PtdIns) 3-phosphate and PtdIns 3,5-bisphosphate as substrates while MTMR13/SBF2 is catalytically inactive but can form a tetrameric complex with MTMR2, resulting in a strong increase of the enzymatic activity of complexed MTMR2. To prove that MTMR13/SBF2 is the disease-causing gene in CMT4B2 and to provide a suitable animal model, we have generated Mtmr13/Sbf2-deficient mice. These animals reproduced myelin outfoldings and infoldings in motor and sensory peripheral nerves as the pathological hallmarks of CMT4B2, concomitant with decreased motor performance. The number and complexity of myelin misfoldings increased with age, associated with axonal degeneration, and decreased compound motor action potential amplitude. Prolonged F-wave latency indicated a mild NCV impairment. Loss of Mtmr13/Sbf2 did not affect the levels of its binding partner Mtmr2 and the Mtmr2-binding Dlg1/Sap97 in peripheral nerves. Mice deficient in Mtmr13/Sbf2 together with known Mtmr2-deficient animals will be of major value to unravel the disease mechanism in CMT4B and to elucidate the critical functions of protein complexes that are involved in phosphoinositide-controlled processes in peripheral nerve

Randomised controlled non-inferiority trial of primary care-based facilitated access to an alcohol reduction website: cost-effectiveness analysis

To evaluate the 12-month costs and quality-adjusted life years (QALYs) gained to the Italian National Health Service of facilitated access to a website for hazardous drinkers compared with a standard face-to-face brief intervention (BI)

Randomised controlled non-inferiority trial of primary care based facilitated access to an alcohol reduction website (EFAR-FVG)

Introduction There is a strong body of evidence demonstrating effectiveness of brief interventions by primary care professionals for risky drinkers but implementation levels remain low. Facilitated access to an alcohol reduction website constitutes an innovative approach to brief intervention, offering a time-saving alternative to face to face intervention, but it is not known whether it is as effective. Objective To determine whether facilitated access to an alcohol reduction website is equivalent to face to face intervention. Methods Randomised controlled non-inferiority trial for risky drinkers comparing facilitated access to a dedicated website with face to face brief intervention conducted in primary care settings in the Region of Friuli Venezia-Giulia, Italy. Adult patients are given a leaflet inviting them to log on to a website to complete the AUDIT-C alcohol screening questionnaire. Screen positives are requested to complete an online trial module including consent, baseline assessment and randomisation to either standard intervention by the practitioner or facilitated access to an alcohol reduction website. Follow up assessment of risky drinking is undertaken online at 1 month, 3 months and 1 year using the full AUDIT questionnaire. Proportions of risky drinkers in each group will be calculated and non-inferiority assessed against a specified margin of 10%. The trial is being undertaken as an initial pilot and a subsequent main trial. Results 12 practices have participated in the pilot, and more than 1300 leaflets have been distributed. 89 patients have been recruited to the trial with a one month follow-up rate of 79%. Discussion The findings of the pilot study suggest that the trial design is feasible, though modifications will be made to optimize performance in the main trial which will commence in January 2014. Plans are concurrently underway to replicate the trial in Australia, and potentially in the UK and Spain

Download Your Doctor: Implementation of a Digitally Mediated Personal Physician Presence to Enhance Patient Engagement With a Health-Promoting Internet Application.

BACKGROUND: Brief interventions delivered in primary health care are effective in reducing excessive drinking; online behavior-changing technique interventions may be helpful. Physicians may actively encourage the use of such interventions by helping patients access selected websites (a process known as "facilitated access"). Although the therapeutic working alliance plays a significant role in the achievement of positive outcomes in face-to-face psychotherapy and its development has been shown to be feasible online, little research has been done on its impact on brief interventions. Strengthening patients' perception of their physician's endorsement of a website could facilitate the development of an effective alliance between the patient and the app. OBJECTIVE: We describe the implementation of a digitally mediated personal physician presence to enhance patient engagement with an alcohol-reduction website as part of the experimental online intervention in a noninferiority randomized controlled trial. We also report the feedback of the users on the module. METHODS: The Download Your Doctor module was created to simulate the personal physician presence for an alcohol-reduction website that was developed for the EFAR-FVG trial conducted in the Italian region of Friuli-Venezia-Giulia. The module was designed to enhance therapeutic alliance and thus improve outcomes in the intervention group (facilitated access to the website). Participating general and family practitioners could customize messages and visual elements and upload a personal photo, signature, and video recordings. To assess the perceptions and attitudes of the physicians, a semistructured interview was carried out 3 months after the start of the trial. Participating patients were invited to respond to a short online questionnaire 12 months following recruitment to investigate their evaluation of their online experiences. RESULTS: Nearly three-quarters (23/32, 72%) of the physicians interviewed chose to customize the contents of the interaction with their patients using the provided features and acknowledged the ease of use of the online tools. The majority of physicians (21/32, 57%) customized at least the introductory photo and video. Barriers to usage among those who did not customize the contents were time restrictions, privacy concerns, difficulties in using the tools, and considering the approach not useful. Over half (341/620, 55.0%) of participating patients completed the optional questionnaire. Many of them (240/341, 70.4%) recalled having noticed the personalized elements of their physicians, and the majority of those (208/240, 86.7%) reacted positively, considering the personalization to be of either high or the highest importance. CONCLUSIONS: The use of a digitally mediated personal physician presence online was both feasible and welcomed by both patients and physicians. Training of the physicians seems to be a key factor in addressing perceived barriers to usage. Further research is recommended to study the mechanisms behind this approach and its impact. TRIAL REGISTRATION: Clinicaltrials.gov NCT 01638338; https://clinicaltrials.gov/ct2/show/NCT01638338 (Archived by WebCite at http://www.webcitation.org/6f0JLZMtq)

A randomized controlled non-inferiority trial of primary care-based facilitated access to an alcohol reduction website (EFAR-FVG): preliminary results

Background The effectiveness of brief interventions for risky drinkers by GPs is well documented.[1] However, implementation levels remain low. Facilitated access to an alcohol reduction website offers an alternative to standard face-to-face intervention, but it is unclear whether it is as effective.[2] This study evaluates whether online brief intervention, through GP facilitated access to an alcohol reduction website for risky drinkers, is not inferior to the face-to-face brief intervention conducted by GPs. Material and methods In a northern Italy region participating GPs actively encouraged all patients age 18 attending their practice, to access an online screening website based on AUDIT-C.[3] Those screening positive underwent a baseline assessment with the AUDIT-10[4] and EQ-5D[5] questionnaires and subsequently, were randomly assigned to receive either online counselling on the alcohol reduction website (intervention) or face-to-face intervention based on the brief motivational interview[6] by their GP (control). Follow-up took place at 3 and 12 months and the outcome was calculated on the basis of the proportion of risky drinkers in each group according to the AUDIT-10. Results More than 50% (n= 3974) of the patients who received facilitated access logged-on to the website and completed the AUDIT-C. Just under 20% (n = 718) screened positive and 94% (n= 674) of them completed the baseline questionnaires and were randomized. Of the 310 patients randomized to the experimental Internet intervention, 90% (n = 278) logged-on to the site. Of the 364 patients of the control group, 72% (263) were seen by their GP. A follow-up rate of 94% was achieved at 3 months. Conclusions The offer of GP facilitated access to an alcohol reduction website appears to be an effective way of identifying risky drinkers and enabling them to receive brief intervention

Randomised controlled non-inferiority trial of primary care-based facilitated access to an alcohol reduction website

Background: Brief interventions (BIs) delivered in primary care have been shown to be effective in reducing risky drinking, but implementation is limited. Facilitated access to a digital application offers a novel alternative to face-to-face intervention, but its relative effectiveness is unknown.Methods: Primary care-based, non-inferiority, randomised controlled trial comparing general practitioner (GP) facilitated access to an interactive alcohol reduction website (FA) with face-to-face BI for risky drinking. Patients screening positive on the short Alcohol Use Disorders Identification Test (AUDIT-C) were invited to participate in the trial. Assessment at baseline, 3 months and 12 months was carried out using AUDIT and EQ-5D-5L questionnaires. Findings: 58 participating GPs approached 9080 patients of whom 4529 (49.9%) logged on, 3841 (84.8%) undertook screening, 822 (21.4%) screened positive and 763 (19.9%) were recruited. 347 (45.5%) were allocated to FA and 416 (54.5%) to BI. At 3 months, subjects in FA group with an AUDIT score of ≥8 reduced from 95 (27.5%) to 85 (26.8%) while those in BI group increased from 123 (20.6%) to 141 (37%). Differences between groups were principally due to responses to AUDIT question 10. Analysis of primary outcome indicated non-inferiority of FA compared with BI, and prespecified subgroup analysis indicated benefits for older patients and those with higher levels of computer literacy and lower baseline severity. Additional analyses undertaken to take account of bias in response to AUDIT question 10 failed to support non-inferiority within the prespecified 10% boundary.Interpretation: Prespecified protocol-driven analyses of the trial indicate that FA is non-inferior to BI; however, identified bias in the outcome measure and further supportive analyses question the robustness of this finding. It is therefore not possible to draw firm conclusions from this trial, and further research is needed to determine whether the findings can be replicated using more robust outcome measures.Trial registration number NCT01638338; Results

Charcot-Marie-Tooth type 4B2 demyelinating neuropathy in miniature Schnauzer dogs caused by a novel splicing SBF2 (MTMR13) genetic variant: a new spontaneous clinical model

This study reports the first genetic variant in Miniature Schnauzer dogs responsible for the occurrence of a demyelinating peripheral neuropathy with abnormally folded myelin. This discovery establishes a genotype/phenotype correlation in affected Miniature Schnauzers that can be used for the diagnosis of these dogs. It further supports the dog as a natural model of a human disease; in this instance, Charcot-Marie-Tooth disease. It opens avenues to search the biological mechanisms responsible for the disease and to test new therapies in a non-rodent large animal model. In particular, recent gene editing methods that led to the restoration of dystrophin expression in a canine model of muscular dystrophy could be applied to other canine models such as this before translation to humans