Heterogeneity of cellular inflammatory responses in ageing white matter and relationship to Alzheimer’s and small vessel disease pathologies

Abstract: White matter lesions (WML) are common in the ageing brain, often arising in a field effect of diffuse white matter abnormality. Although WML are associated with cerebral small vessel disease (SVD) and Alzheimer’s disease (AD), their cause and pathogenesis remain unclear. The current study tested the hypothesis that different patterns of neuroinflammation are associated with SVD compared to AD neuropathology by assessing the immunoreactive profile of the microglial (CD68, IBA1 and MHC‐II) and astrocyte (GFAP) markers in ageing parietal white matter (PARWM) obtained from the Cognitive Function and Ageing Study (CFAS), an ageing population‐representative neuropathology cohort. Glial responses varied extensively across the PARWM with microglial markers significantly higher in the subventricular region compared to either the middle‐zone (CD68 p = 0.028, IBA1 p < 0.001, MHC‐II p < 0.001) or subcortical region (CD68 p = 0.002, IBA1 p < 0.001, MHC‐II p < 0.001). Clasmatodendritic (CD) GFAP+ astrocytes significantly increased from the subcortical to the subventricular region (p < 0.001), whilst GFAP+ stellate astrocytes significantly decreased (p < 0.001). Cellular reactions could be grouped into two distinct patterns: an immune response associated with MHC‐II/IBA1 expression and CD astrocytes; and a more innate response characterised by CD68 expression associated with WML. White matter neuroinflammation showed weak relationships to the measures of SVD, but not to the measures of AD neuropathology. In conclusion, glial responses vary extensively across the PARWM with diverse patterns of white matter neuroinflammation. Although these findings support a role for vascular factors in the pathogenesis of age‐related white matter neuroinflammation, additional factors other than SVD and AD pathology may drive this. Understanding the heterogeneity in white matter neuroinflammation will be important for the therapeutic targeting of age‐associated white matter damage

Effectiveness of a national quality improvement programme to improve survival after emergency abdominal surgery (EPOCH): a stepped-wedge cluster-randomised trial

Background: Emergency abdominal surgery is associated with poor patient outcomes. We studied the effectiveness of a national quality improvement (QI) programme to implement a care pathway to improve survival for these patients. Methods: We did a stepped-wedge cluster-randomised trial of patients aged 40 years or older undergoing emergency open major abdominal surgery. Eligible UK National Health Service (NHS) hospitals (those that had an emergency general surgical service, a substantial volume of emergency abdominal surgery cases, and contributed data to the National Emergency Laparotomy Audit) were organised into 15 geographical clusters and commenced the QI programme in a random order, based on a computer-generated random sequence, over an 85-week period with one geographical cluster commencing the intervention every 5 weeks from the second to the 16th time period. Patients were masked to the study group, but it was not possible to mask hospital staff or investigators. The primary outcome measure was mortality within 90 days of surgery. Analyses were done on an intention-to-treat basis. This study is registered with the ISRCTN registry, number ISRCTN80682973. Findings: Treatment took place between March 3, 2014, and Oct 19, 2015. 22 754 patients were assessed for elegibility. Of 15 873 eligible patients from 93 NHS hospitals, primary outcome data were analysed for 8482 patients in the usual care group and 7374 in the QI group. Eight patients in the usual care group and nine patients in the QI group were not included in the analysis because of missing primary outcome data. The primary outcome of 90-day mortality occurred in 1210 (16%) patients in the QI group compared with 1393 (16%) patients in the usual care group (HR 1·11, 0·96–1·28). Interpretation: No survival benefit was observed from this QI programme to implement a care pathway for patients undergoing emergency abdominal surgery. Future QI programmes should ensure that teams have both the time and resources needed to improve patient care. Funding: National Institute for Health Research Health Services and Delivery Research Programme

Effectiveness of a national quality improvement programme to improve survival after emergency abdominal surgery (EPOCH): a stepped-wedge cluster-randomised trial

BACKGROUND: Emergency abdominal surgery is associated with poor patient outcomes. We studied the effectiveness of a national quality improvement (QI) programme to implement a care pathway to improve survival for these patients. METHODS: We did a stepped-wedge cluster-randomised trial of patients aged 40 years or older undergoing emergency open major abdominal surgery. Eligible UK National Health Service (NHS) hospitals (those that had an emergency general surgical service, a substantial volume of emergency abdominal surgery cases, and contributed data to the National Emergency Laparotomy Audit) were organised into 15 geographical clusters and commenced the QI programme in a random order, based on a computer-generated random sequence, over an 85-week period with one geographical cluster commencing the intervention every 5 weeks from the second to the 16th time period. Patients were masked to the study group, but it was not possible to mask hospital staff or investigators. The primary outcome measure was mortality within 90 days of surgery. Analyses were done on an intention-to-treat basis. This study is registered with the ISRCTN registry, number ISRCTN80682973. FINDINGS: Treatment took place between March 3, 2014, and Oct 19, 2015. 22 754 patients were assessed for elegibility. Of 15 873 eligible patients from 93 NHS hospitals, primary outcome data were analysed for 8482 patients in the usual care group and 7374 in the QI group. Eight patients in the usual care group and nine patients in the QI group were not included in the analysis because of missing primary outcome data. The primary outcome of 90-day mortality occurred in 1210 (16%) patients in the QI group compared with 1393 (16%) patients in the usual care group (HR 1·11, 0·96-1·28). INTERPRETATION: No survival benefit was observed from this QI programme to implement a care pathway for patients undergoing emergency abdominal surgery. Future QI programmes should ensure that teams have both the time and resources needed to improve patient care. FUNDING: National Institute for Health Research Health Services and Delivery Research Programme

The development of an isoform-specific JNK3 inhibitor

Mitogen-activated protein kinases (MAPK) are involved in a variety of signal transduction mechanisms as a response to a wide range of cellular stress stimuli. The ASK/MKK/JNK protein kinase cascade is involved in such signal transduction. The dysfunction of these cascades has been identified to impact downstream signaling effectors linked with the onset of neurodegeneration and cancer. c-Jun N-terminal kinases (JNK) are attractive therapeutic targets due to the rising interest in developing treatment for these diseases. Among the ten JNK isoforms (JNK1a/ß-1/2; JNK2a/ß-1,2; JNK3a-1/2), the two JNK3 isoforms' tissue distribution are near exclusive to the Central Nervous System (CNS). The objective of this work is to develop an isoform specific JNK3 inhibitor based on the structural protein interactions of JNK3 with its upstream kinases. Based on preliminary kinase assays comparing JNK3a2 and JNK2a2, it was supported that the novel Maltose Binding Protein (MBP)-fusion peptide inhibitor MBP-NJ40 was successful in isoform specificity in favor of JNK3a2. Another novel MBP-fusion peptide inhibitor, MBP-NJ20, was also investigated in its efficacy to inhibit JNK3a2. The half-maximal inhibitory concentration (IC50) of both MBP-NJ40 and MBP-NJ20 when analyzed were comparable to each other. This suggests that these inhibitors are successful novel candidates for controlled inhibition of JNK3a2

*WINNER* Identifying patterns in the culturable skin microbiome of Appalachian salamanders

Batrachochytrium dendrobatidis (Bd) is a fungal pathogen that has devastated amphibian populations worldwide.  However, in the eastern United States, salamander populations persist in the presence of this fungus with relatively low rates of infection.  We hypothesize that probiotic species within the salamander cutaneous microbiome protect their host by inhibiting growth of Bd.  During previous work, we identified cutaneous defenses of salamanders by isolating bacteria from skin swabs and challenging them against Bd.  The objectives of our current work are to (1) characterize the microbiome through 16S sequencing techniques, and (2) determine whether the culturable microbiome differs based on host species and/or habitat. Salamanders belonging to the genera Desmognathus (n = 8), Eurycea (n = 7), and Plethodon (n = 7) were sampled in the Great Smoky Mountains National Park. From their skin swabs, we obtained and sequenced a total of 110 bacterial isolates. Bioinformatics analyses were conducted using the software mothur, and a two-way permutated multivariate analysis of variance was conducted in Primer7. Preliminary results indicate that differentiation exists between the microbiome of terrestrial and aquatic salamanders. In addition, 81% of inhibitory isolates occurred on Plethodon glutinosus salamanders, and Gram-positive bacilli accounted for 38% of inhibitory isolates. During future work, we will compare our findings to the high-throughput sequencing dataset to confirm if these patterns hold true.  We hope our work will pinpoint the best candidate probiotics and help establish a procedure for treating amphibians infected with Bd

Data from: Rev7 and 53BP1/Crb2 prevent RecQ helicase-dependent hyper-resection of DNA double-strand breaks

Poly(ADP ribose) polymerase inhibitors (PARPi) target cancer cells deficient in homology-directed repair of DNA double-strand breaks (DSBs). In preclinical models, PARPi resistance is tied to altered nucleolytic processing (resection) at the 5' ends of a DSB. For example, loss of 53BP1 or Rev7/MAD2L2/FANCV derepresses resection to drive PARPi resistance, although the mechanisms are poorly understood. Long-range resection can be catalyzed by two machineries: the exonuclease Exo1, or the combination of a RecQ helicase and Dna2. Here, we develop a single cell microscopy assay that allows the distinct phases and machineries of resection to be interrogated simultaneously in living S. pombe cells. Using this assay, we find that the 53BP1 orthologue and Rev7 specifically repress long-range resection through the RecQ helicase-dependent pathway, thereby preventing hyper-resection. These results suggest that 'rewiring' of BRCA1-deficient cells to employ an Exo1-independent hyper-resection pathway is a driver of PARPi resistance

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