Threonine 149 Phosphorylation Enhances ΔFosB Transcriptional Activity to Control Psychomotor Responses to Cocaine

Stable changes in neuronal gene expression have been studied as mediators of addicted states. Of particular interest is the transcription factor ΔFosB, a truncated and stable FosB gene product whose expression in nucleus accumbens (NAc), a key reward region, is induced by chronic exposure to virtually all drugs of abuse and regulates their psychomotor and rewarding effects. Phosphorylation at Ser[superscript 27] contributes to ΔFosB's stability and accumulation following repeated exposure to drugs, and our recent work demonstrates that the protein kinase CaMKIIα phosphorylates ΔFosB at Ser[superscript 27] and regulates its stability in vivo. Here, we identify two additional sites on ΔFosB that are phosphorylated in vitro by CaMKIIα, Thr[superscript 149] and Thr[superscript 180], and demonstrate their regulation in vivo by chronic cocaine. We show that phosphomimetic mutation of Thr[superscript 149] (T149D) dramatically increases AP-1 transcriptional activity while alanine mutation does not affect transcriptional activity when compared with wild-type (WT) ΔFosB. Using in vivo viral-mediated gene transfer of ΔFosB-T149D or ΔFosB-T149A in mouse NAc, we determined that overexpression of ΔFosB-T149D in NAc leads to greater locomotor activity in response to an initial low dose of cocaine than does WT ΔFosB, while overexpression of ΔFosB-T149A does not produce the psychomotor sensitization to chronic low-dose cocaine seen after overexpression of WT ΔFosB and abrogates the sensitization seen in control animals at higher cocaine doses. We further demonstrate that mutation of Thr[superscript 149] does not affect the stability of ΔFosB overexpressed in mouse NAc, suggesting that the behavioral effects of these mutations are driven by their altered transcriptional properties

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Gamma frequency entrainment attenuates amyloid load and modifies microglia

Changes in gamma oscillations (20-50 Hz) have been observed in several neurological disorders. However, the relationship between gamma oscillations and cellular pathologies is unclear. Here we show reduced, behaviourally driven gamma oscillations before the onset of plaque formation or cognitive decline in a mouse model of Alzheimer's disease. Optogenetically driving fast-spiking parvalbumin-positive (FS-PV)-interneurons at gamma (40 Hz), but not other frequencies, reduces levels of amyloid-β (Aβ)[subscript 1-40] and Aβ [subscript 1-42] isoforms. Gene expression profiling revealed induction of genes associated with morphological transformation of microglia, and histological analysis confirmed increased microglia co-localization with Aβ. Subsequently, we designed a non-invasive 40 Hz light-flickering regime that reduced Aβ[subscript 1-40] and Aβ[subscript 1-42] levels in the visual cortex of pre-depositing mice and mitigated plaque load in aged, depositing mice. Our findings uncover a previously unappreciated function of gamma rhythms in recruiting both neuronal and glial responses to attenuate Alzheimer's-disease-associated pathology.National Institutes of Health (U.S.) (Grant 1R01EY023173)National Institutes of Health (U.S.) (Grant 1DP1NS087724)National Institutes of Health (U.S.) (Grant RF1AG047661)National Institutes of Health (U.S.) (Grant ROIGM104948

Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

Background: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. Methods: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). Findings: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92). Interpretation: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention

Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

Background: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. Methods: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). Findings: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92). Interpretation: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention

Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

BACKGROUND: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. METHODS: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). FINDINGS: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29-146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0- 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25-1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39-1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65-1·60]; p=0·92). INTERPRETATION: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention. FUNDING: British Heart Foundation

Bacterial Artificial Chromosome (BAC) Array CGH Study of B-CLL Patients with 17p13 Deletion.

Abstract B-cell chronic lymphocytic leukaemia is characterised by a highly variable clinical course. Clone specific chromosomal imbalances have a significant prognostic ability with deletion of 17p13 being associated with advanced disease and resistance to therapy, deletion of 11q with progressive disease and extensive lymphadenopathy, deletion of 13q14 on its own with good prognosis and trisomy 12 with atypical morphology and an intermediate prognosis. In the MRC CLL 4 trial, a randomised study of conventional therapy with chlorambucil vs fludarabine either on its own or in combination with cyclophosphamide, 7% (40/580) of patients had deletions at 17p13. In this study 17p13 deletion was associated with the worst clinical outcome. However, considerable heterogeneity in clinical behaviour was observed with 60% dying within 1 year and 18 % alive at 3 years. This raises the question of whether other genetic variants co-segregating with 17p- modulate clinical behaviour. In order to investigate these possibilities we have identified seven patients with 17p13.1 deletion and screened them for p53 mutation. Using FISH they were screened for deletions of 11q22, 13q14 and trisomy12. One had an associated deletion at 11q22 and four at 13q14. Trisomy 12 was not detected in this group. Subsequently a global genome analyses using a 5.8K BAC array CGH platforms was carried out looking for regions of amplifications and deletions. Using this system to characterise the 17p deletion region further we were able to show that deletions were present at 17 p11.2, 17 p12–13.1 and 17p13.2–3. with variation in site and extent of deletion. These findings suggest that although the p53 gene on 17p13.1 is considered the target gene in this deletion, more than 1 gene in the region could be involved in contributing to poor prognosis. We are investigating whether this may contribute to the differential outcome in this group. Considering changes at other sites in the genome we have shown amplifications at 2p14–p25(1/7), 5q23(1/7), 6q14(1/7), 7q21(1/7), 8q24(1/7), 11p15(1/7), 11q13(1/7), 12p13(1/7), 16p12 –13(2/7), 17q21.2–q21.31(2/7) and deletions at 3p12.3–p26(1/7), 6q14–q22(2/7), 6q16–25(1/7), 9p21–p22.3(1/7), 9q31–q33(1/7), 11q13–22/23.1(1/7), 11q25(1/7), 12q13(1/7), 13q14.3–q21.1(4/7) 13q13.1–q13.3(1/7), 18p11.2–13.3(2/7) and 20p11.21–13 (1/7). Chromosomal sites recurrently involved in the 7 patients or known to be involved in CLL are in bold. Multiple cases with either amplification at 17q or deletion of 13q and 18p suggest that oncogene and tumour suppressor genes may be located at these regions. The zygosity states of these regions and the genes contained within them will be examined further and presented. The presence of multiple changes in the genome of CLL with 17p deletion is suggestive of genomic instability in this disease subgroup. We will compare these findings with changes in CLLs lacking such deletions. In addition we will analyse more cases to define recurrent genetic events contributing to this poor risk group of CLL and the deletion pattern on 17p together with p53 inactivation by mutation.</jats:p

Brn3b regulates the formation of fear-related midbrain circuits and defensive responses to visual threat.

Defensive responses to visually threatening stimuli represent an essential fear-related survival instinct, widely detected across species. The neural circuitry mediating visually triggered defensive responses has been delineated in the midbrain. However, the molecular mechanisms regulating the development and function of these circuits remain unresolved. Here, we show that midbrain-specific deletion of the transcription factor Brn3b causes a loss of neurons projecting to the lateral posterior nucleus of the thalamus. Brn3b deletion also down-regulates the expression of the neuropeptide tachykinin 2 (Tac2). Furthermore, Brn3b mutant mice display impaired defensive freezing responses to visual threat precipitated by social isolation. This behavioral phenotype could be ameliorated by overexpressing Tac2, suggesting that Tac2 acts downstream of Brn3b in regulating defensive responses to threat. Together, our experiments identify specific genetic components critical for the functional organization of midbrain fear-related visual circuits. Similar mechanisms may contribute to the development and function of additional long-range brain circuits underlying fear-associated behavior

Combined aCGH and Mutational Analysis of CLL Patients with 17p Deletion.

Abstract We have utilised aCGH (Breakthrough Breast Cancer Research Centre 5.8K array) and mutational analysis of the TP53 gene (exons 4–10) on 74 cases of CLL to define the extent of deletion at 17p, TP53 mutational status, additional genomic changes, and how this affects clinical outcome. 17p- cases were selected by FISH (n=37, Vysis LSI P53 probe) and 37 cases were selected as being representative of the survival curve of CLL patients without 17p-. FISH identified 22 cases with TP53- in ≥ 50% of cells, 4 cases with TP53- 20–50% and 11 cases with TP53- ≤ 20%. aCGH can detect abnormalities present in &gt;50% of cells and all of the TP53- cases greater than 50% by FISH were detected with deletion ranging between 6-20Mb in length, the majority encompassing the entire p-arm. In addition aCGH detected deletion of 17p in 5/15 cases with TP53- &lt;50%, and 2/37 with no detectable TP53- by FISH, these deletions clustered at 17p13.3 and 17p11.2, and did not involve the TP53 gene. Cases with 17p- &gt;20% have a poor clinical outcome (median survival 11 months, median progression free survival 3 months), the majority of these (85%) also have a mutation of TP53 whereas in cases with ≤ 20% 17p- only 10% were mutated. The 17p- group was characterised by additional recurrent deletions involving 18p, 20p and 22q, which tended to occur as single additional events. Understanding the order in which these events occur is important, 18p- was found in 6 cases, 2 of which had &lt;50% 17p- by FISH, suggesting that 18p- is present in a higher percentage of cells and by implication occurs prior to the 17p deletion, a similar finding was also present for the 20p- cases. 18p deletion varied in length between 5.9Mb and 12Mb, with the minimally deleted region (MDR) involving a 2.5Mb region spanning 18p11.23-p11.22. 20p- was found in 8 cases of which 3 covered almost the entire p-arm, and 5 formed 2 clusters at each end of the p-arm. 22q- was found in 8 cases, with only 1 outside of the 17p- group. Out of these 8 cases with deletion, 6 covered almost the complete q-arm but a MDR was difficult to define, however if the non-17p- case is excluded the MDR covers 1.4Mb at 22q12.3. Recurrent abnormalities were also found on other chromosomes, but did not differ between the two groups. These included regions with previously identified abnormalities; trisomy 12 (n=11), loss of 6q14.1–24.3 (n=11), loss of 11q12.1–25 (n=17) and loss of 13q12.1–21.1 (n=6) as well as detection of novel abnormalities; gain of 4p16.3–16.1 (n=23), gain of 11p15.5–15.3 (n=22), gain of 22q11.21–13.33 (n=22) and deletions on chromosome 9 (n=9). These results show that deletion of TP53 and mutation of the other allele are critical adverse prognostic factors. We have also defined a genetic background (18p-, 20p- and 22q-) on which these changes arise.</jats:p