Biology subjects

Keeley, D. P.

Publications and source records attributed to Keeley, D. P..

3 recordsLinked to original sources

bioRxiv2021

Hemicentin mediated type IV collagen assembly strengthens juxtaposed basement membrane linkage

Basement membrane (BM) matrices surround and separate most tissues. However, through poorly understood mechanisms, BMs of adjacent tissues can also stably link to support organ structure and function. Using endogenous knock-in fluorescent proteins, conditional RNAi, optogenetics, and quantitative live imaging, we identified matrix proteins mediating a BM linkage (B-LINK) between the uterine utse and epidermal seam cell BMs in Caenorhabditis elegans that supports the uterus during egg-laying. We found that hemicentin is secreted by the utse and promotes fibulin-1 assembly to jointly initiate the B-LINK. During egg-laying, however, both proteins decline in levels and are not required for B-LINK maintenance. Instead, we discovered that hemicentin also promotes type IV collagen assembly, which accumulates to high levels during egg-laying and sustains the B-LINK during the mechanically active egg-laying period. This work reveals mechanisms underlying BM-BM connection maturation and identifies a crucial function for hemicentin and fibulin-1 in initiating attachment and type IV collagen in strengthening this specialized form of tissue linkage. SummaryTissue attachment through linking juxtaposed basement membranes (BMs) is crucial for the structure and function of many organs. Gianakas et al. identify a key role for hemicentin and fibulin-1 in initiating BM-BM attachment and type IV collagen in stabilizing this linkage and allowing it to resist high mechanical loads.

developmental biology↗

bioRxiv2021

Fluorogenic EXO-Probe Aptamers for Imaging and Tracking Exosomal RNAs

Small extracellular vesicles (sEVs), or exosomes, play important roles in physiological and pathological cellular communication. sEVs contain both short and long non-coding RNAs that regulate gene expression and epigenetic processes. Studying the intricacies of sEV function and RNA-based communication requires tools capable of labeling sEV RNA. Here we developed a novel genetically encodable reporter system for tracking sEV RNAs comprising an sEV-loading RNA sequence, termed the EXO-Code, fused to a fluorogenic RNA Mango aptamer for RNA imaging. This fusion construct allowed the visualization and tracking of RNA puncta and colocalization with markers of multivesicular bodies; imaging RNA puncta within sEVs; and quantification of sEVs. This technology represents a useful and versatile tool to interrogate the role of sEVs in cellular communication via RNA trafficking to sEVs, cellular sorting decisions, and sEV RNA cargo transfer to recipient cells.

bioengineering↗

bioRxiv2021

Micro-Meta App: an interactive software tool to facilitate the collection of microscopy metadata based on community-driven specifications

For the information content of microscopy images to be appropriately interpreted, reproduced, and meet FAIR (Findable Accessible Interoperable and Reusable) principles, they should be accompanied by detailed descriptions of microscope hardware, image acquisition settings, image pixel and dimensional structure, and instrument performance. Nonetheless, the thorough documentation of imaging experiments is significantly impaired by the lack of community-sanctioned easy-to-use software tools to facilitate the extraction and collection of relevant microscopy metadata. Here we present Micro-Meta App, an intuitive open-source software designed to tackle these issues that was developed in the context of nascent global bioimaging community organizations, including BioImaging North America (BINA) and QUAlity Assessment and REProducibility in Light Microscopy (QUAREP-LiMi), whose goal is to improve reproducibility, data quality and sharing value for imaging experiments. The App provides a user-friendly interface for building comprehensive descriptions of the conditions utilized to produce individual microscopy datasets as specified by the recently proposed 4DN-BINA-OME tiered-system of Microscopy Metadata model. To achieve this goal the App provides a visual guide for a microscope-user to: 1) interactively build diagrammatic representations of hardware configurations of given microscopes that can be easily reused and shared with colleagues needing to document similar instruments. 2) Automatically extracts relevant metadata from image files and facilitates the collection of missing image acquisition settings and calibration metrics associated with a given experiment. 3) Output all collected Microscopy Metadata to interoperable files that can be used for documenting imaging experiments and shared with the community. In addition to significantly lowering the burden of quality assurance, the visual nature of Micro-Meta App makes it particularly suited for training users that have limited knowledge of the intricacies of light microscopy experiments. To ensure wide-adoption by microscope-users with different needs Micro-Meta App closely interoperates with MethodsJ2 and OMERO.mde, two complementary tools described in parallel manuscripts.

bioinformatics↗