bioRxiv Science⌕ Search

Biology subjects

Bateman, J.

Publications and source records attributed to Bateman, J..

5 recordsLinked to original sources

The cellular basis of mitochondrial stress signaling in the brain

Neuronal vulnerability to stress is highly cell-type specific, but the underlying mechanisms are poorly understood. Here we show that the ability to activate endoplasmic reticulum (ER) stress signaling is encoded by the relative mitochondrial metabolic activity of neurons. Genetically inducing mitochondrial dysfunction in the Drosophila brain caused the emergence of a novel cluster of neurons, detected using single nuclear RNA-sequencing, that activated the ER unfolded protein response (UPR). UPR activation occurred only in neurons with high mitochondrial activity. Unexpectedly, mitochondria-ER contacts were also abundant in the neurons that activated the UPR but virtually undetectable in neurons with low mitochondrial activity. In the human brain, strikingly, excitatory neurogranin neurons had the highest mitochondrial activity and triggered the UPR. The selective activation of the UPR only in neurons with high mitochondrial activity is therefore conserved. This study reveals the remarkable dependence on the inherent oxidative metabolic activity of neurons to activate the UPR.

neuroscience↗

Modification of the microstructure of the CERN- CLEAR-VHEE beam at the picosecond scale modifies ZFE morphogenesis but has no impact on hydrogen peroxide production.

FLASH has emerged as a significant breakthrough for the future of radiation oncology, as it reduces complications while preserving the tumor killing efficacy. To define the beam parameters for future clinical translation, Very High Energy Electrons (VHEE) delivered at CLEAR and able to reach deep seated tumors were used in conjunction with a FLASH-validated Intermediate Energy Electron (IIE) beam and a 160-225 keV X-ray beam, collectively able to deliver dose rates spanning from 1 Gy/min to 1011 Gy/s. High-throughput chemical assays were used to investigate radiochemical effects of FLASH, while zebrafish embryos served as a model to evaluate its impact on biological outcomes and morphogenesis. This study is the first comprehensive exploration investigating the impact of a large range of dose rates and various temporal parameters from early physico-chemical events to a complex biological system. Data derived at CLEAR revealed that the intensity of the bunch is a critical factor for observing the sparing effect of FLASH and uncovered an unforeseen biological response when electrons are delivered over the picosecond timescale. Present data also suggests that scanning with high intensity beamlets will be optimal for the future clinical translation of FLASH. HighlightsTo investigate the physics parameters required to trigger the FLASH sparing effect, CLEAR/VHEE/CERN beam macro/microstructure was varied. We show that delivery at the picosecond scale: - reduces alteration in the morphogenesis of zebrafish embryos, but - has no impact on secondary hydrogen peroxide production, Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=175 HEIGHT=200 SRC="FIGDIR/small/629203v1_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@1df896aorg.highwire.dtl.DTLVardef@b6b824org.highwire.dtl.DTLVardef@1f35964org.highwire.dtl.DTLVardef@171d60f_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

Amputation Triggers Long-Range Epidermal Permeability Changes in Evolutionarily Distant Regenerative Organisms

Previous studies have reported that amputation invokes body-wide responses in regenerative organisms, but most have not examined the implications of these changes beyond the region of tissue regrowth. Specifically, long-range epidermal responses to amputation are largely uncharacterized, with research on amputation-induced epidermal responses in regenerative organisms traditionally being restricted to the wound site. Here, we investigate the effect of amputation on long-range epidermal permeability in two evolutionarily distant, regenerative organisms: axolotls and planarians. We find that amputation triggers a long-range increase in epidermal permeability in axolotls, accompanied by a long-range epidermal downregulation in MAPK signaling. Additionally, we provide functional evidence that pharmacologically inhibiting MAPK signaling in regenerating planarians increases long-range epidermal permeability. These findings advance our knowledge of body-wide changes due to amputation in regenerative organisms and warrant further study on whether epidermal permeability dysregulation in the context of amputation may lead to pathology in both regenerative and non-regenerative organisms. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=167 SRC="FIGDIR/small/610385v2_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@81b022org.highwire.dtl.DTLVardef@52c2e9org.highwire.dtl.DTLVardef@17a5f93org.highwire.dtl.DTLVardef@118b8f6_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

A paradigm for regulation at the effector interface with RNA-binding proteins

RNA-binding proteins (RBPs) are key regulators of gene expression, but how RBPs convey regulatory instructions to the core effectors of RNA processing is unclear. Here we document the existence and functions of a multivalent RBP-effector interface. We show that the effector interface of a deeply conserved RBP with an essential role in metazoan development, Unkempt, is mediated by a novel type of dual-purpose peptide motifs that can contact two different surfaces of interacting proteins. Unexpectedly, we find that the multivalent contacts do not merely serve effector recruitment but are required for the accuracy of RNA recognition by the recruiting RBP. Systems analyses reveal that multivalent RBP-effector contacts can repurpose the principal activity of an effector for a different function, as we demonstrate for reuse of the central eukaryotic mRNA decay factor CCR4-NOT in translational control. Our study establishes the molecular assembly and functional principles of an RBP-effector interface, with implications for the evolution and function of RBP-operated regulatory networks.

molecular biology↗

Cartilage microRNA dysregulation during the onset and progression of mouse osteoarthritis overlaps with patient disease candidates

To explore the role of microRNAs in osteoarthritis (OA), we conducted microRNA expression profiling on micro-dissected tibial cartilage and subchondral bone in a mouse model of OA produced by medial meniscus destabilization (DMM). DMM mice had characteristic cartilage degeneration, subchondral bone sclerosis and osteophyte formation. While subchondral bone showed no microRNA dysregulation, 139 microRNAs were differentially expressed in DMM cartilage at 1 and/or 6 weeks after OA initiation. To prioritize OA-candidates, dysregulated microRNAs with human orthologues were filtered using paired microRNA:mRNA expression analysis to identify those with corresponding changes in mRNA target transcripts in the DMM cartilage. An important cohort overlapped with microRNAs identified in human end-stage OA. Comparisons with microRNAs dysregulation in DMM mouse cartilage where aggrecan cleavage was genetically-ablated demonstrated that all were independent of aggrecan breakdown, earmarking these as important to the critical stages of OA initiation. Our comprehensive analyses identified high-priority microRNA candidates that have potential as human OA-biomarkers and therapeutic targets.\n\nSUMMARYKung et al. conducted global analysis of microRNA dysregulation in joint tissues of a well-established mouse osteoarthritis model. Stringent filtering against human microRNA orthologues, integrated mRNA target analysis and comparison with published studies on human end-stage osteoarthritis identified microRNA candidates of potential clinical relevance.

cell biology↗