Search bioRxiv⌕ Search

Biology subjects

Corona, C.

Publications and source records attributed to Corona, C..

8 recordsLinked to original sources

Peripheral anatomy of the dolphin ear and associated nervous structures: insights from macroscopic dissection, DICE-{micro}CT, histology, and confocal microscopy

The peripheral auditory system of dolphins comprises specialised bony, fatty, vascular, and neural structures adapted for underwater hearing and diving physiology. These include the external ear canal, acoustic fat bodies, sinuses, and associated neurovascular networks, which together support sound conduction, protection, and possibly sensory functions. Despite advances in gross anatomical description, the detailed integration of these tissues, particularly the innervation, neurovascular organisation, and their functional implications, remains poorly understood. Previous studies have described the presence of sensory nerve formations and vascular plexuses, but their arrangement, connectivity, and relation to each other are unresolved. Here, we combine macroscopic dissection, DICE-{micro}CT, histology, and high-resolution confocal microscopy to characterise several neurovascular and sensory components of the dolphin peripheral auditory system in several delphinid species. Macroscopic dissection and DICE-{micro}CT revealed the traditional acoustic fat body distribution with detailed morphology of the posterolateral extension that is not well-known. The cranial nerve distribution, and specifically the mandibular nerve branching patterns, are described in detail. Confocal microscopy uncovered a stratified neurovascular plexus around the external ear canal with a complex sensory system comprising lamellar corpuscles, Merkel cell-neurite complexes, and intraepithelial nerve fibres. Notably, the lamellar corpuscles formed a continuous, three-dimensional neural network with frequent merging and splitting of axonal bundles, shared perineuria, and vascular integration, features not observed in previous studies. Our findings demonstrate that the dolphin external ear canal and surrounding structures form a sophisticated, multimodal somatosensory organ, integrating structural, vascular, and neural specialisations likely adapted for proprioceptive mechanosensation in the aquatic environment. This study provides insights into the integration of the various components of the peripheral hearing apparatus. Future studies integrating anatomical, electrophysiological, and biomechanical approaches are needed to fully elucidate these adaptations.

neuroscience↗

Targeting Neuromuscular Junction Regeneration is a Therapeutic Strategy in ALS

Instability and denervation of the neuromuscular junction (NMJ) are early events in Amyotrophic Lateral Sclerosis (ALS), likely reflecting a progressive decline in the regenerative capacity of motor neurons (MNs) and their environment. To investigate this, we evaluated NMJ regeneration throughout disease progression in SOD1G93A mice following reversible axon terminal degeneration induced by -Latrotoxin. In parallel, we monitored the expression of CXCR4, a GPCR upregulated during axonal regeneration, and tested whether its pharmacological activation could mitigate ALS- related functional decline. We found that NMJ regenerative capacity is largely preserved during pre- and early symptomatic stages, and remains active in subsets of NMJs even at later stages. CXCR4 is expressed at axon terminals from early disease stages, declining only at end stage. Its expression is conserved across ALS models, including SOD1G93A pigs, hiPSC-derived MN with ALS mutations, and biopsies from sporadic ALS patients. CXCR4 stimulation improved motor function, NMJ innervation, MN survival, and respiratory performance in ALS mice, and axon outgrowth in iPSC-derived MN. These findings identify the NMJ and CXCR4 as viable therapeutic targets in ALS.

neuroscience↗

Deep learning-driven morphology analysis enables label-free classification of therapeutic agent- naive versus resistant cancer cells

Therapeutic drug treatments of solid tumors are often undermined by various resistance mechanisms. Identification of drug-resistance phenotypes at the single cell level is challenging because conventional molecular methods are cell-destructive, labor-intensive, and cost-prohibitive. To overcome these challenges, we developed an orthogonal approach to drug-resistance phenotyping, through the use of deep-learning-driven morphology analysis of single, high resolution cell images. Specifically, we trained deep learning-based drug resistance classifiers using cell images from 5 different cell lines that were rendered resistant to 5 different therapeutic agents, using a foundation model framework. With high accuracy, the classifier correctly predicted naive or resistance phenotypes across all cancer types and across all the therapeutic agent types (chemotherapeutic, targeted) tested. These results showed that morphology can capture complex phenotype information in the context of drug treatment. To demonstrate the potential clinical utility of the drug resistance classifier, it was applied to a dissociated tumor biopsy and the resulting phenotype predictions were in close concordance with scRNASeq analysis of the biopsy. Our study highlights the potential of deep-learning-driven morphology analysis to provide complex phenotype information, and ultimately shape oncology drug treatment strategies at the patient-level in a clinical context.

cancer biology↗

Label-Free Melanoma Phenotype Classification Using Artificial Intelligence-Based Morphological Profiling

Melanomas are the deadliest skin cancers, in part due to cellular plasticity and heterogeneity. Intratumoral heterogeneity drives varied mutable phenotypes, specifically "melanocytic" and "mesenchymal" cell states, which result in differential functional properties and drug responses. Definitive and rigorous classification of these phenotypic states has been challenging with conventional biomarker-based methods, and high-parameter molecular methods are cell-destructive, labor-intensive, and time-consuming. To overcome these technical and practical limitations, we utilized label-free artificial intelligence-based morphological profiling to classify live melanoma cells into melanocytic and mesenchymal phenotypes based on high resolution imaging of single cells. To predict the phenotypes of single melanoma cells based on morphology alone, we developed the AI-based Melanoma Phenotype Classifier trained with 19 patient-derived cell lines with known melanocytic or mesenchymal transcriptional profiles. To link phenotypic state with high-dimensional morphological profiles, cells were subjected to genetic and chemical perturbations known to shift phenotypic states. The AI classifier successfully predicted phenotypic shifts which were confirmed by single-cell RNA-Seq (scRNA-Seq). These results demonstrate that correlations between melanoma cell phenotypes and morphological changes are detectable by AI. Additionally, the Melanoma Phenotype Classifier was applied to dissociated tumor biopsy samples and characterization of phenotypic heterogeneity was supported by scRNA-Seq transcriptional profiles. This work establishes a link between cell morphology and melanoma phenotypes, laying the groundwork for the use of a label-free morphology-based method for phenotyping live melanoma cells combined with additional analyses.

cancer biology↗

Biomimetic human lung alveolar interstitium chip with extended longevity

Determining the mechanistic causes of lung diseases, developing new treatments thereof, and assessing toxicity whether from chemical exposures or engineered nanomaterials would benefit significantly from a preclinical human lung alveolar interstitium model of physiological relevance. The existing preclinical models have limitations because they fail to replicate the key anatomical and physiological characteristics of human alveoli. Thus, a human lung alveolar interstitium chip was developed to imitate key alveolar microenvironmental factors including: an electrospun nanofibrous membrane as the analogue of the basement membrane for co-culture of epithelial cells with fibroblasts embedded in 3D collagenous gels; physiologically relevant interstitial matrix stiffness; interstitial fluid flow; and 3D breathing-like mechanical stretch. The biomimetic chip substantially improved epithelial barrier function compared to transwell models. Moreover, the chip having a gel made of a collagen I-fibrin blend as the interstitial matrix sustained the interstitium integrity and further enhanced the epithelial barrier resulting in a longevity that extended beyond eight weeks. The assessment of multiwalled carbon nanotube toxicity on the chip was in line with the animal study.

bioengineering↗

Retinoschisin deficiency induces persistent aberrant waves of activity affecting neuroglial signaling in the retina

Genetic disorders which present during development make treatment strategies particularly challenging because there is a need to disentangle primary pathophysiology from downstream dysfunction caused at key developmental stages. To provide a deeper insight into this question, we studied a mouse model of X-linked juvenile retinoschisis (XLRS), an early onset inherited condition caused by mutations in the RS1 gene encoding retinoschisin (RS1) and characterized by cystic retinal lesions and early visual deficits. Using an unbiased approach in expressing the fast intracellular calcium indicator GCaMP6f in neuronal, glial, and vascular cells of the retina of mice lacking RS1, we found that initial cyst formation is paralleled by the appearance of aberrant spontaneous neuro-glial signals as early as postnatal day 13. These presented as glutamate-driven wavelets of neuronal activity and sporadic radial bursts of activity by Muller glia, spanning all retinal layers and disrupting light-induced signaling. This study highlights a critical role for RS1 in early retinal development with a potential to disrupt circuit formation to central targets. Additionally, it confers a functional role to RS1 beyond the scope of an adhesion molecule and identifies an early onset for dysfunction, a potential temporal target for therapeutic intervention and diagnosis. Significance Statement/ HighlightsO_LIPhotoreceptor inner segments express Rs1 at P5, after which RS1 protein is detected in the inner segments by P9 and throughout the retina at later ages, with structural abnormalities observed by optical coherence tomography at P13 in Rs1 mutant mouse models. C_LIO_LIAberrant glutamate-driven wavelets identified by GCaMP6f-based analyses are a novel pathophysiological feature of RS1 deficient mice that emerge after maximal RS1 expression. C_LIO_LIMuller glia display abnormal radial glutamate-driven coordinated and sporadic bursts of activity in RS1-deficient mice. C_LIO_LIThese data identify a novel pathophysiological feature of RS1-deficient mice and define a window where treatments might be most effective. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=127 SRC="FIGDIR/small/457777v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@3f27eborg.highwire.dtl.DTLVardef@55e5a4org.highwire.dtl.DTLVardef@1577435org.highwire.dtl.DTLVardef@8e55b3_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

AAV-BR1 targets endothelial cells in the retina to reveal their morphological diversity and to deliver Cx43.

Endothelial cells (ECs) are key players in the development and maintenance of the vascular tree, the establishment of the blood brain barrier and control of blood flow. Disruption in ECs is an early and active component of vascular pathogenesis. However, our ability to selectively target ECs in the CNS for identification and manipulation is limited. Here, in the mouse retina, a tractable model of the CNS, we utilized a recently developed AAV-BR1 system to identify distinct classes of ECs along the vascular tree using a GFP reporter. We then developed an inducible EC-specific ectopic Connexin 43 (Cx43) expression system using AAV-BR1-CAG-DIO-Cx43-P2A-DsRed2 in combination with a mouse line carrying inducible CreERT2 in ECs. We targeted Cx43 because its loss has been implicated in microvascular impariment in numerous diseases such as diabetic retinopathy and vascular edema. GFP-labeled ECs were numerous, evenly distributed along the vascular tree and their morphology was polarized with respect to the direction of blood flow. After tamoxifen induction, ectopic Cx43 was specifically expressed in ECs. Similarly to endogenous Cx43, ectopic Cx43 was localized at the membrane contacts of ECs and it did not affect tight junction proteins. The ability to enhance gap junctions in ECs provides a precise and potentially powerful tool to treat microcirculation deficits, an early pathology in numerous diseases.

neuroscience↗

Retina-specific targeting of pericytes reveals structural diversity and enables control of capillary blood flow

Pericytes are a unique class of mural cells essential for angiogenesis, maintenance of the vasculature and are key players in microvascular pathology. However, their diversity and specific roles are poorly understood, limiting our insight into vascular physiology and the ability to develop effective therapies. Here, in the mouse retina, a tractable model of the CNS, we evaluated distinct classes of mural cells along the vascular tree for both structural characterization and physiological manipulation of blood flow. To accomplish this, we first tested three inducible mural cell-specific mouse lines using a sensitive Ai14 reporter and tamoxifen application either by a systemic injection, or by local administration in the form of eye drops. Across three lines, under either the PDGFRb or NG2 promoter, the specificity and pattern of Cre activation varied significantly. In particular, a mouse line with Cre under the NG2 promoter resulted in sparse TdTomato labeling of mural cells, allowing for an unambiguous characterization of anatomical features of individual sphincter cells and capillary pericytes. Furthermore, in one PDGFRb line, we found that focal eye drop application of tamoxifen led to an exclusive Cre-activation in pericytes, without affecting arterial mural cells. We then used this approach to boost capillary blood flow by selective expression of Halorhodopsin, a highly precise hyperpolarizing optogenetic actuator. The ability to exclusively target capillary pericytes may prove a precise and potentially powerful tool to treat microcirculation deficit, a common pathology in numerous diseases.

neuroscience↗