SUMMARY Though much is known about the cellular and molecular components of the circadian clock, output pathways that couple clock cells to overt behaviors have not been identified. We conducted a screen for circadian-relevant neurons in the Drosophila brain, and report here that cells of the pars intercerebralis (PI), a functional homologue of the mammalian hypothalamus, comprise an important component of the circadian output pathway for rest:activity rhythms. GRASP analysis demonstrates that PI cells are connected to the clock through a polysynaptic circuit extending from pacemaker cells to PI neurons. Molecular profiling of relevant PI cells identified the corticotropin releasing factor (CRF) homologue, DH44, as a circadian output molecule that is specifically expressed by PI neurons and required for normal rest:activity rhythms. Notably, selective activation or ablation of just 6 DH44+ PI cells causes arrhythmicity. These findings delineate a circuit through which clock cells can modulate locomotor rhythms.

Organisms must utilize multiple mechanisms to maintain energetic homeostasis in the face of limited nutrient availability. One mechanism involves activation of the heterotrimeric AMP-activated protein kinase (AMPK), a cell-autonomous sensor to energetic changes regulated by ATP to AMP ratios. We examined the phenotypic consequences of reduced AMPK function, both through RNAi knockdown of the gamma subunit (AMPKγ) and through expression of a dominant negative alpha (AMPKα) variant in Drosophila melanogaster. Reduced AMPK signaling leads to hypersensitivity to starvation conditions as measured by lifespan and locomotor activity. Locomotor levels in flies with reduced AMPK function were lower during unstressed conditions, but starvation-induced hyperactivity, an adaptive response to encourage foraging, was significantly higher than in wild type. Unexpectedly, total dietary intake was greater in animals with reduced AMPK function yet total triglyceride levels were lower. AMPK mutant animals displayed starvation-like lipid accumulation patterns in metabolically key liver-like cells, oenocytes, even under fed conditions, consistent with a persistent starved state. Measurements of O2 consumption reveal that metabolic rates are greater in animals with reduced AMPK function. Lastly, rapamycin treatment tempers the starvation sensitivity and lethality associated with reduced AMPK function. Collectively, these results are consistent with models that AMPK shifts energy usage away from expenditures into a conservation mode during nutrient-limited conditions at a cellular level. The highly conserved AMPK subunits throughout the Metazoa, suggest such findings may provide significant insight for pharmaceutical strategies to manipulate AMPK function in humans.

SUMMARYIn Drosophila, two related G-protein-coupled receptors are members of the corticotropin releasing factor (CRF) receptor subfamily. We have previously reported that one of these receptors, encoded by CG8422 is a functional receptor for a diuretic hormone, DH 44 . Here, we report that the other CRF receptor subfamily member, encoded by CG12370, is also a receptor for the DH 44 neuropeptide. The lines of evidence to support this identification include increases in cAMP levels due to CG12370 receptor activation and the recruitment of β-arrestin-GFP to the plasma membrane in response to DH 44 application. We compared these features of the receptors DH44-R2 (encoded by CG12370) and DH44-R1 (encoded by CG8422) and found fundamental differences in signaling, association with the arrestins, and peptide sensitivity. We found that the sensitivity of DH44-R2 to the DH 44 peptide is lower than that of DH44-R1, specifically an estimated EC 50 of 7.98E-07 mol l -1 for DH 44 by DH44-R2 to an EC 50 of 5.12E-09 mol l -1 by DH44-R1 and found that previous reports on the sensitivity of the tubule to DH 44 is in agreement with our measurements of DH44-R2 sensitivity. We employed a specific RNAi construct to selectively knock-down DH44-R2 expression and this led to heightened sensitivity to osmotic challenges. The functional characterization of this diuretic hormone receptor in Drosophila demonstrates a high degree of conservation of CRF-like signaling.

This study reports on data sourced from patients with biopsy-confirmed CCCA and examines the relationships between various factors and severity of CCCA. The findings demonstrate that duration of hair loss is positively associated with severity of disease and that androgen-related conditions are prevalent in those affected with CCCA.

Introduction and aims Unresolved social diffi culties are prevalent in oncology patients, can impact on well-being and undermine ability to cope with the larger stressors of disease and treatment. Information may deal with psychosocial issues without over-burdening staff. A randomised pilot study investigated the impact of a specifi cally designed Support Services Information Pack (SSIP) on levels of social distress in routine practice. Methods The SSIP was designed and evaluated. Adult patients receiving active treatment were randomised to intervention or control group. The Social Diffi culties Inventory (SDI-21) assessed the severity of social diffi culties at baseline and after the last of four review consultations. The intervention group received the SSIP prior to the second consultation. The sum of 16 of the SDI-21 items was used to provide an overall index of social distress (SD-16, range 0 to 44). All participants were interviewed on completion. Counts were taken of the number that used the SSIP. Analysis of covariance tests compared mean SD-16 scores. Results Participants: 165 patients were approached, 88 consented and 75 completed the study. Complete SD-16 data was available for 70 patients. The SSIP was not extensively used; the majority of patients read it but took no action, but may use it in future (67%). The mean SD-16 scores were 8.53 for the intervention group (95% CI 7.1 to 9.9) and 8.25 for the control group (CI 6.7 to 9.8). Conclusion During this pilot study the SSIP was not used. Timing of delivery of the intervention will be investigated in future trials.