Abscisic acid induced a negative geotropic response in dark-incubated Chlamydomonas reinhardtii

© 2019, The Author(s). The phytohormone abscisic acid (ABA) plays a role in stresses that alter plant water status and may also regulate root gravitropism and hydrotropism. ABA also exists in the aquatic algal progenitors of land plants, but other than its involvement in stress responses, its physiological role in these microorganisms remains elusive. We show that exogenous ABA significantly altered the HCO3− uptake of Chamydomonas reinhardtii in a light-intensity-dependent manner. In high light ABA enhanced HCO3− uptake, while under low light uptake was diminished. In the dark, ABA induced a negative geotropic movement of the algae to an extent dependent on the time of sampling during the light/dark cycle. The algae also showed a differential, light-dependent directional taxis response to a fixed ABA source, moving horizontally towards the source in the light and away in the dark. We conclude that light and ABA signal competitively in order for algae to position themselves in the water column to minimise photo-oxidative stress and optimise photosynthetic efficiency. We suggest that the development of this response mechanism in motile algae may have been an important step in the evolution of terrestrial plants and that its retention therein strongly implicates ABA in the regulation of their relevant tropisms

Chimeric Activators and Repressors Define HY5 Activity and Reveal a Light-Regulated Feedback Mechanism

The first exposure to light marks a crucial transition in plant development. This transition relies on the transcription factor HY5 controlling a complex downstream growth program. Despite its importance, its function in transcription remains unclear. Previous studies have generated lists of thousands of potential target genes and competing models of HY5 transcription regulation. In this work, we carry out detailed phenotypic and molecular analysis of constitutive activator and repressor HY5 fusion proteins. Using this strategy, we were able to filter out large numbers of genes that are unlikely to be direct targets, allowing us to eliminate several proposed models of HY5's mechanism of action. We demonstrate that the primary activity of HY5 is promoting transcription, and that this function relies on other, likely light-regulated, factors. In addition, this approach reveals a molecular feedback loop via the COP1/SPA E3-ubiquitin ligase complex suggesting novel mechanism which maintains low HY5 in the dark, primed for rapid accumulation to reprogram growth upon light exposure. Our strategy is broadly adaptable to the study of transcription factor activity. Lastly, we show that modulating this feedback loop can generate significant phenotypic diversity in both Arabidopsis and tomato

Electroacupuncture for Fatigue, Sleep, and Psychological Distress in Breast Cancer Patients with Aromatase Inhibitor-related Arthralgia: A Randomized Trial

BACKGROUND Although fatigue, sleep disturbance, depression, and anxiety are associated with pain in breast cancer patients, it is unknown whether acupuncture can decrease these comorbid symptoms in cancer patients with pain. The objective of this study was to evaluate the effect of electroacupuncture (EA) on fatigue, sleep, and psychological distress in breast cancer survivors who experience joint pain related to aromatase inhibitors (AIs). METHODS The authors performed a randomized controlled trial of an 8‐week course of EA compared with a waitlist control (WLC) group and a sham acupuncture (SA) group in postmenopausal women with breast cancer who self‐reported joint pain attributable to AIs. Fatigue, sleep disturbance, anxiety, and depression were measured using the Brief Fatigue Inventory (BFI), the Pittsburgh Sleep Quality Index (PSQI), and the Hospital Anxiety and Depression Scale (HADS). The effects of EA and SA versus WLC on these outcomes were evaluated using mixed‐effects models. RESULTS Of the 67 randomly assigned patients, baseline pain interference was associated with fatigue (Pearson correlation coefficient [r]=0.75; P \u3c .001), sleep disturbance (r=0.38; P=.0026), and depression (r=0.58; P \u3c .001). Compared with the WLC condition, EA produced significant improvements in fatigue (P=.0095), anxiety (P=.044), and depression (P=.015) and a nonsignificant improvement in sleep disturbance (P=.058) during the 12‐week intervention and follow‐up period. In contrast, SA did not produce significant reductions in fatigue or anxiety symptoms but did produce a significant improvement in depression compared with the WLC condition (P=.0088). CONCLUSIONS Compared with usual care, EA produced significant improvements in fatigue, anxiety, and depression; whereas SA improved only depression in women experiencing AI‐related arthralgia. Cancer 2014;120:3744–3751. © 2014 American Cancer Society

Electroacupuncture for fatigue, sleep, and psychological distress in breast cancer patients with aromatase inhibitor‐related arthralgia: A randomized trial

BACKGROUND Although fatigue, sleep disturbance, depression, and anxiety are associated with pain in breast cancer patients, it is unknown whether acupuncture can decrease these comorbid symptoms in cancer patients with pain. The objective of this study was to evaluate the effect of electroacupuncture (EA) on fatigue, sleep, and psychological distress in breast cancer survivors who experience joint pain related to aromatase inhibitors (AIs). METHODS The authors performed a randomized controlled trial of an 8‐week course of EA compared with a waitlist control (WLC) group and a sham acupuncture (SA) group in postmenopausal women with breast cancer who self‐reported joint pain attributable to AIs. Fatigue, sleep disturbance, anxiety, and depression were measured using the Brief Fatigue Inventory (BFI), the Pittsburgh Sleep Quality Index (PSQI), and the Hospital Anxiety and Depression Scale (HADS). The effects of EA and SA versus WLC on these outcomes were evaluated using mixed‐effects models. RESULTS Of the 67 randomly assigned patients, baseline pain interference was associated with fatigue (Pearson correlation coefficient [r]=0.75; P \u3c .001), sleep disturbance (r=0.38; P=.0026), and depression (r=0.58; P \u3c .001). Compared with the WLC condition, EA produced significant improvements in fatigue (P=.0095), anxiety (P=.044), and depression (P=.015) and a nonsignificant improvement in sleep disturbance (P=.058) during the 12‐week intervention and follow‐up period. In contrast, SA did not produce significant reductions in fatigue or anxiety symptoms but did produce a significant improvement in depression compared with the WLC condition (P=.0088). CONCLUSIONS Compared with usual care, EA produced significant improvements in fatigue, anxiety, and depression; whereas SA improved only depression in women experiencing AI‐related arthralgia. Cancer 2014;120:3744–3751. © 2014 American Cancer Society

Electroacupuncture for Fatigue, Sleep, and Psychological Distress in Breast Cancer Patients with Aromatase Inhibitor-related Arthralgia: A Randomized Trial

BACKGROUND Although fatigue, sleep disturbance, depression, and anxiety are associated with pain in breast cancer patients, it is unknown whether acupuncture can decrease these comorbid symptoms in cancer patients with pain. The objective of this study was to evaluate the effect of electroacupuncture (EA) on fatigue, sleep, and psychological distress in breast cancer survivors who experience joint pain related to aromatase inhibitors (AIs). METHODS The authors performed a randomized controlled trial of an 8‐week course of EA compared with a waitlist control (WLC) group and a sham acupuncture (SA) group in postmenopausal women with breast cancer who self‐reported joint pain attributable to AIs. Fatigue, sleep disturbance, anxiety, and depression were measured using the Brief Fatigue Inventory (BFI), the Pittsburgh Sleep Quality Index (PSQI), and the Hospital Anxiety and Depression Scale (HADS). The effects of EA and SA versus WLC on these outcomes were evaluated using mixed‐effects models. RESULTS Of the 67 randomly assigned patients, baseline pain interference was associated with fatigue (Pearson correlation coefficient [r]=0.75; P \u3c .001), sleep disturbance (r=0.38; P=.0026), and depression (r=0.58; P \u3c .001). Compared with the WLC condition, EA produced significant improvements in fatigue (P=.0095), anxiety (P=.044), and depression (P=.015) and a nonsignificant improvement in sleep disturbance (P=.058) during the 12‐week intervention and follow‐up period. In contrast, SA did not produce significant reductions in fatigue or anxiety symptoms but did produce a significant improvement in depression compared with the WLC condition (P=.0088). CONCLUSIONS Compared with usual care, EA produced significant improvements in fatigue, anxiety, and depression; whereas SA improved only depression in women experiencing AI‐related arthralgia. Cancer 2014;120:3744–3751. © 2014 American Cancer Society

Fluorescence circadian imaging reveals a PDF-dependent transcriptional regulation of the Drosophila molecular clock

Circadian locomotor behaviour is controlled by a pacemaker circuit composed of clock-containing neurons. To interrogate the mechanistic relationship between the molecular clockwork and network communication critical to the operation of the Drosophila circadian pacemaker circuit, we established new fluorescent circadian reporters that permit single-cell recording of transcriptional and post-transcriptional rhythms in brain explants and cultured neurons. Live-imaging experiments combined with pharmacological and genetic manipulations demonstrate that the neuropeptide pigment-dispersing factor (PDF) amplifies the molecular rhythms via time-of-day- and activity-dependent upregulation of transcription from E-box-containing clock gene promoters within key pacemaker neurons. The effect of PDF on clock gene transcription and the known role of PDF in enhancing PER/TIM stability occur via independent pathways downstream of the PDF receptor, the former through a cAMP-independent mechanism and the latter through a cAMP-PKA dependent mechanism. These results confirm and extend the mechanistic understanding of the role of PDF in controlling the synchrony of the pacemaker neurons. More broadly, our results establish the utility of the new live-imaging tools for the study of molecular-neural interactions important for the operation of the circadian pacemaker circuit

Circadian rhythms in neuronal activity propagate through output circuits

24hr rhythms in behavior are organized by a network of circadian pacemaker neurons. Rhythmic activity in this network is generated by intrinsic rhythms in clock neuron physiology and communication between clock neurons. However, it is poorly understood how the activity of a small number of pacemaker neurons is translated into rhythmic behavior of the whole animal. To understand this, we screened for signals that could identify circadian output circuits in Drosophila. We found that Leucokinin neuropeptide (LK) and its receptor (LK-R) are required for normal behavioral rhythms. This LK/LK-R circuit connects pacemaker neurons to brain areas that regulate locomotor activity and sleep. Our experiments revealed that pacemaker neurons impose rhythmic activity and excitability on LK and LK-R expressing neurons. We also found pacemaker neuron-dependent activity rhythms in DH44-expressing neurons, a second circadian output pathway. We conclude that rhythmic clock neuron activity propagates to multiple downstream circuits to orchestrate behavioral rhythms