Neuroimmune mechanisms in autism etiology - untangling a complex problem using human cellular models.

Autism spectrum disorder (ASD) affects 1 in 36 people and is more often diagnosed in males than in females. Core features of ASD are impaired social interactions, repetitive behaviors and deficits in verbal communication. ASD is a highly heterogeneous and heritable disorder, yet its underlying genetic causes account only for up to 80% of the cases. Hence, a subset of ASD cases could be influenced by environmental risk factors. Maternal immune activation (MIA) is a response to inflammation during pregnancy, which can lead to increased inflammatory signals to the fetus. Inflammatory signals can cross the placenta and blood brain barriers affecting fetal brain development. Epidemiological and animal studies suggest that MIA could contribute to ASD etiology. However, human mechanistic studies have been hindered by a lack of experimental systems that could replicate the impact of MIA during fetal development. Therefore, mechanisms altered by inflammation during human pre-natal brain development, and that could underlie ASD pathogenesis have been largely understudied. The advent of human cellular models with induced pluripotent stem cell (iPSC) and organoid technology is closing this gap in knowledge by providing both access to molecular manipulations and culturing capability of tissue that would be otherwise inaccessible. We present an overview of multiple levels of evidence from clinical, epidemiological, and cellular studies that provide a potential link between higher ASD risk and inflammation. More importantly, we discuss how stem cell-derived models may constitute an ideal experimental system to mechanistically interrogate the effect of inflammation during the early stages of brain development.

The Warburg micro syndrome protein RAB3GAP1 modulates neuronal morphogenesis and interacts with axon elongation end ER-Golgi trafficking factors.

RAB3GAP1 is GTPase activating protein localized to the ER and Golgi compartments. In humans, mutations in RAB3GAP1 are the most common cause of Warburg Micro syndrome, a neurodevelopmental disorder associated with intellectual disability, microcephaly, and agenesis of the corpus callosum. We found that downregulation of RAB3GAP1 leads to a reduction in neurite outgrowth and complexity in human stem cell derived neurons. To further define the cellular function of RAB3GAP1, we sought to identify novel interacting proteins. We used a combination of mass spectrometry, co-immunoprecipitation and colocalization analysis and identified two novel interactors of RAB3GAP1: the axon elongation factor Dedicator of cytokinesis 7 (DOCK7) and the TATA modulatory factor 1 (TMF1) a modulator of Endoplasmic Reticulum (ER) to Golgi trafficking. To define the relationship between RAB3GAP1 and its two novel interactors, we analyzed their localization to different subcellular compartments in neuronal and non-neuronal cells with loss of RAB3GAP1. We find that RAB3GAP1 is important for the sub-cellular localization of TMF1 and DOCK7 across different compartments of the Golgi and endoplasmic reticulum. In addition, we find that loss of function mutations in RAB3GAP1 lead to dysregulation of pathways that are activated in response to the cellular stress like ATF6, MAPK, and PI3-AKT signaling. In summary, our findings suggest a novel role for RAB3GAP1 in neurite outgrowth that could encompass the regulation of proteins that control axon elongation, ER-Golgi trafficking, as well as pathways implicated in response to cellular stress.

Management of necrotising fasciitis within a burns centre: do outcomes differ?

INTRODUCTION: Many similarities exist between the care of necrotising fasciitis (NF) and burn injury patients. Each group represents a small but complex cohort requiring multiple theatre trips, specialist reconstruction, meticulous wound care and multidisciplinary management. Over a six-year period, we sought to examine the clinical outcomes of NF patients managed within a burns centre against those managed by a plastic surgery service. METHODS: A retrospective case-note review was performed for all identifiable patients referred to our institution's designated burns centre or plastic surgery service between 2008-2014. Patient characteristics, length of stay, wound-related and clinical outcomes were extracted and descriptively presented with statistical analysis performed for survival and length of stay. RESULTS: Twenty-nine patients were included in the study (burns centre [B]: 17 patients; plastic surgery service [P]: 12 patients). Median total length of stay (B: 37 vs. P: 50 days, P=0.38), local length of stay (27 vs. 19 days, P=0.29) and survival till discharge (94.4% vs. 100%, P=0.73) demonstrated no statistically significant difference. CONCLUSION: Caring for NF patients within a burns centre facilitated easier access to specialist reconstructive expertise and multidisciplinary care but did not lead to statistically significant differences in length of stay or survival. The management of NF within a burns centre facilitated provision of high-quality care to a highly challenging patient group.

Exploring methods the for selection and integration of stakeholder views in the development of core outcome sets: a case study in reconstructive breast surgery.

BACKGROUND: The development and use of core outcome sets (COSs) in trials may improve data synthesis and reduce outcome reporting bias. The selection of outcomes in COSs is informed by views of key stakeholders, yet little is known about the role and influence of different stakeholders' views during COS development. We report an exploratory case study examining how stakeholder selection and incorporation of stakeholders' views may influence the selection of outcomes for a COS in reconstructive breast surgery (RBS). We also make recommendations for future considerations. METHODS: Key stakeholder groups and subgroups were identified from the literature and expert opinion by the COS management group. They included health care professionals, subdivided by profession (breast and plastic surgeons, specialist nurses and psychologists) and patients, subdivided according to type of surgery received, timing of reconstruction, time since surgery and patient age. All participated in a survey in which they were asked to prioritise outcomes. Outcomes were prioritised using a 9-point scale from 1 (not important) to 9 (extremely important). The proportion of (1) all participants, ignoring stakeholder group (single heterogeneous panel analysis), (2) 'professional' and 'patient' groups separately (two heterogeneous panels), ignoring prespecified subgroups and (3) each participant subgroup separately (multiple homogeneous panel analysis) rating each item 'extremely important' was summarised and compared to explore how selection and integration of stakeholder views may influence outcome prioritisation. RESULTS: There were many overlaps between items rated as most important by all groups. Specific stakeholders, however, prioritised specific concerns and a broader range of outcomes were prioritised when the subgroups were considered separately. For example, two additional outcomes were prioritised when patient and professional groups were considered separately and eight additional outcomes were identified when the views of the individual subgroups were explored. In general, patient subgroups preferentially valued additional clinical outcomes, including unplanned surgery, whereas professional subgroups prioritised additional psychosocial issues including body image. CONCLUSION: Stakeholder groups value different outcomes. Selection of groups, therefore, is important. Our recommendations for robust and transparent stakeholder selection and integration of stakeholder views may aid future COS developers in the design and conduct of their studies and improve the validity and value of future COS.

Radial dyssynchrony assessed by cardiovascular magnetic resonance in relation to left ventricular function, myocardial scarring and QRS duration in patients with heart failure.

BACKGROUND: Intuitively, cardiac dyssynchrony is the inevitable result of myocardial injury. We hypothesized that radial dyssynchrony reflects left ventricular remodeling, myocardial scarring, QRS duration and impaired LV function and that, accordingly, it is detectable in all patients with heart failure. METHODS: 225 patients with heart failure, grouped according to QRS duration of <120 ms (A, n = 75), between 120-149 ms (B, n = 75) or >or=150 ms (C, n = 75), and 50 healthy controls underwent assessment of radial dyssynchrony using the cardiovascular magnetic resonance tissue synchronization index (CMR-TSI = SD of time to peak inward endocardial motion in up to 60 myocardial segments). RESULTS: Compared to 50 healthy controls (21.8 +/- 6.3 ms [mean +/- SD]), CMR-TSI was higher in A (74.8 +/- 34.6 ms), B (92.4 +/- 39.5 ms) and C (104.6 +/- 45.6 ms) (all p < 0.0001). Adopting a cut-off CMR-TSI of 34.4 ms (21.8 plus 2xSD for controls) for the definition of dyssynchrony, it was present in 91% in A, 95% in B and 99% in C. Amongst patients in NYHA class III or IV, with a LVEF<35% and a QRS>120 ms, 99% had dyssynchrony. Amongst those with a QRS<120 ms, 91% had dyssynchrony. Across the study sample, CMR-TSI was related positively to left ventricular volumes (p < 0.0001) and inversely to LVEF (CMR-TSI = 178.3 e (-0.033 LVEF) ms, p < 0.0001). CONCLUSION: Radial dyssynchrony is almost universal in patients with heart failure. This vies against the notion that a lack of response to CRT is related to a lack of dyssynchrony.