Bruner, S. | bioRxiv Science

bioRxiv2025

Cytoplasmic CaMKIIδ-B prevents myocardial recovery in heart failure

Restoration of cardiac function in patients with advanced heart failure is rare, and the molecular processes that regulate recovery are unknown. To identify potential mechanisms, we studied paired myocardial samples before and after left ventricular assist device therapy, where significant cardiac functional recovery occurred in [~]25% of patients. We found that expression of the nuclear B isoform of Ca2+/calmodulin-dependent protein kinase II{delta} (CaMKII{delta}-B) inversely correlated with recovery. Furthermore, increased phosphorylation near the CaMKII{delta}-B nuclear localization signal in non-responders prevented its auto-activation dependent nuclear translocation. Expression of a cytoplasm-restricted CaMKII{delta}-B in cardiomyocytes dramatically remodeled the phospho-proteome and impaired contractility, while a nuclear-competent version did not. Modulating CaMKII{delta} subcellular localization may thus represent a therapeutic strategy for advanced heart failure.

physiology↗

bioRxiv2020

Novel insights from point-dendrometers in an urban setting: linking environmental variation to fluctuations in stem radius.

BackgroundReal-time monitoring of tree growth can provide novel information about trees in urban/suburban areas and the myriad ecosystem services they provide. By monitoring irrigated specimen trees we test the hypothesis that in trees with sufficient water, growth is governed by environmental factors regulating energy gain rather than by factors related to water use. MethodsInternet enabled, high-resolution dendrometers were installed on three trees in Southampton, NY. The instruments, along with a weather station, streamed data to a project web page that was updated once an hour. (https://ecosensornetwork.com). Growing periods were determined using a Hidden Markov Model based on Zweifel et al.s (2016) zero-growth model. Linear models and conditional inference trees correlated environmental variables to growth magnitude and rate of growth. ResultsGrowth was governed by the interacting environmental variables of air temperature, soil moisture, VPD and took place primarily at night. Radial growth of spruce began April 14 after the accumulation of 69.7 {degrees}C growing degrees days and ended September 7th. Cedar growth began later (April 26th), after the accumulation of 160.6 {degrees}C and ended later (November 3rd). During the observation period, these three modest suburban trees sequestered 108.3 kg of CO2. ConclusionsThough irrigated, residential tree growth in our experiment was affected by environmental factors relating to both water use and energy gain through photosynthesis. Linking tree growth to fluctuations in environmental conditions facilitates the development of a predictive understanding useful for ecosystem management and growth forecasting across future altering climates.

ecology↗