Photopharmacological Applications for Cherenkov Radiation Generated by Clinically Used Radionuclides

Translational photopharmacological applications are limited through irradiation by light showing wavelengths within the bio-optical window. To achieve sufficient tissue penetration, using wavelengths >500 nm is mandatory. Nevertheless, the majority of photopharmacological compounds respond to irradiation with more energetic UV light, which shows only a minor depth of tissue penetration in the µm range. Thus, we became interested in UV light containing Cherenkov radiation (CR) induced as a by-product by clinically employed radionuclides labeling specific tissues. Therefore, CR may be applicable in novel photopharmacological approaches. To provide evidence for the hypothesis, we verified the clinically established radionuclides 68Ga and 90Y but not 18F in clinically used activities to be capable of generating CR in aqueous solutions. We then investigated whether the generated CR was able to photoactivate the caged kinase inhibitor cagedAZD5438 as a photoresponsive model system. Herein, 21% uncaging of the model system cagedAZD5438 occurred by incubation with 90Y, along with a non-specific compound decomposition for 68Ga and partly for 90Y. The findings suggest that the combination of a clinically employed radionuclide with an optimized photoresponsive agent could be beneficial for highly focused photopharmacological therapies

Pharmacological and genetic manipulations of Ca2+ signaling have contrasting effects on auxin-regulated trafficking

A large part of a plants’ developmental plasticity relies on the activities of the phytohormone auxin and the regulation of its own distribution. This process involves a cohort of transcriptional and non-transcriptional effects of auxin on polar auxin transport, regulating the abundancy, biochemical activity and polar localization of the molecular components, predominantly PIN auxin exporters. While the transcriptional auxin signaling cascade has been well characterized, the mechanism and role of non-transcriptional auxin signaling remains largely elusive. Here, we addressed the potential involvement of auxin-induced Ca2+ signaling in auxin’s inhibitory effect on PIN endocytic trafficking. On the one hand, exogenous manipulations of Ca2+ availability and signaling effectively antagonized auxin effects suggesting that auxin-induced Ca2+ signaling is required for inhibition of internalization. On the other hand, we addressed the auxin-mediated inhibition of PIN internalization in the auxin signaling (tir1afb2,3) or Ca2+ channel (cngc14) mutants. These mutants were strongly defective in auxin-triggered Ca2+ signaling, but not in auxin-inhibited internalization. These data imply that, while Ca2+ signaling may be required for normal PIN trafficking, auxin-mediated increase in Ca2+ signaling is not a direct part of a downstream mechanism that mediates auxin effects on Brefeldin A-visualized PIN intercellular aggregation. These contrasting results obtained by comparing the mutant analysis versus the exogenous manipulations of Ca2+ availability and signaling illustrate the critical importance of genetics to unravel the role of Ca2+ in a process of interest

Author Guide for Addressing Animal Methods Bias in Publishing

There is growing recognition that animal methods bias, a preference for animal‐based methods where they are not necessary or where nonanimal‐based methods may already be suitable, can impact the likelihood or timeliness of a manuscript being accepted for publication. Following April 2022 workshop about animal methods bias in scientific publishing, a coalition of scientists and advocates formed a Coalition to Illuminate and Address Animal Methods Bias (COLAAB). The COLAAB has developed this guide to be used by authors who use nonanimal methods to avoid and respond to animal methods bias from manuscript reviewers. It contains information that researchers may use during 1) study design, including how to find and select appropriate nonanimal methods and preregister a research plan, 2) manuscript preparation and submission, including tips for discussing methods and choosing journals and reviewers that may be more receptive to nonanimal methods, and 3) the peer review process, providing suggested language and literature to aid authors in responding to biased reviews. The author's guide for addressing animal methods bias in publishing is a living resource also available online at animalmethodsbias.org, which aims to help ensure fair dissemination of research that uses nonanimal methods and prevent unnecessary experiments on animals

Recruitment and Baseline Characteristics of Participants in the AgeWell.de Study: A Pragmatic Cluster-Randomized Controlled Lifestyle Trial against Cognitive Decline

Targeting dementia prevention, first trials addressing multiple modifiable risk factors showed promising results in at-risk populations. In Germany, AgeWell.de is the first large-scale initiative investigating the effectiveness of a multi-component lifestyle intervention against cognitive decline. We aimed to investigate the recruitment process and baseline characteristics of the AgeWell.de participants to gain an understanding of the at-risk population and who engages in the intervention. General practitioners across five study sites recruited participants (aged 60-77 years, Cardiovascular Risk Factors, Aging, and Incidence of Dementia/CAIDE dementia risk score ≥ 9). Structured face-to-face interviews were conducted with eligible participants, including neuropsychological assessments. We analyzed group differences between (1) eligible vs. non-eligible participants, (2) participants vs. non-participants, and (3) between intervention groups. Of 1176 eligible participants, 146 (12.5%) dropped out before baseline; the study population was thus 1030 individuals. Non-participants did not differ from participants in key sociodemographic factors and dementia risk. Study participants were M = 69.0 (SD = 4.9) years old, and 52.1% were women. The average Montreal Cognitive Assessment/MoCA score was 24.5 (SD = 3.1), indicating a rather mildly cognitively impaired study population; however, 39.4% scored ≥ 26, thus being cognitively unimpaired. The bandwidth of cognitive states bears the interesting potential for differential trial outcome analyses. However, trial conduction is impacted by the COVID-19 pandemic, requiring adjustments to the study protocol with yet unclear methodological consequences

Function of the anion transporter AtCLC-d in the trans-Golgi network

Anion transporting proteins of the CLC type are involved in anion homeostasis in a variety of organisms. CLCs from Arabidopsis have been shown to participate in nitrate accumulation and storage. In this study, the physiological role of the functional chloride transporter AtCLC-d from Arabidopsis was investigated. AtCLC-d is weakly expressed in various tissues, including the root. When transiently expressed as a GFP fusion in protoplasts, it co-localized with the VHA-a1 subunit of the proton-transporting V-type ATPase in the trans-Golgi network (TGN). Stable expression in plants showed that it co-localized with the endocytic tracer dye FM4-64 in a brefeldin A-sensitive compartment. Immunogold electron microscopy confirmed the localization of AtCLC-d to the TGN. Disruption of the AtCLC-d gene by a T-DNA insertion did not affect the nitrate and chloride contents. The overall morphology of these clcd-1 plants was similar to that of the wild-type, but root growth on synthetic medium was impaired. Moreover, the sensitivity of hypocotyl elongation to treatment with concanamycin A, a blocker of the V-ATPase, was stronger in the clcd-1 mutant. These phenotypes could be complemented by overexpression of AtCLC-d in the mutant background. The results suggest that the luminal pH in the trans-Golgi network is adjusted by AtCLC-d-mediated transport of a counter anion such as Cl− or NO3−

Cyclic dynamics drive summer movement ecology of snowshoe hares (Lepus americanus)

Animals exhibit dynamic movement and activity in response to environmental variation including changes in reproductive opportunities, predation risk, or food availability. Yet, it remains unclear which factors are primary in affecting animal movement, and whether the relative importance of these factors are consistent through time. We tracked snowshoe hares (Lepus americanus) using GPS telemetry during eight summers spanning a hare population cycle (2015–2022) in southwestern Yukon, Canada, to determine associations between environmental variation and hare movement and home range size. Hare density varied 25-fold during the study and home range size increased markedly during low hare density, especially for males. Both sexes retained similar core space use and linearity of movements, but at low densities males had greater and more variable movement rates and time spent travelling. Trail cameras revealed that annual changes in hare movement were also correlated with relative abundance of lynx (Lynx canadensis) and coyotes (Canis latrans). However, hare detection rates within a season were not closely associated with seasonal variation in predator detection. Observed differences between male and female hares in some metrics highlighted that different life histories and reproductive behavior are likely the main drivers of hare movement dynamics. Therefore, fitness rewards associated with successful mate search and reproduction appear to outweigh risks associated with increased movement, even in highly variable environments where costs of prioritizing reproduction-related activities are notably high and variable