Biology subjects

Giblin, J.

Publications and source records attributed to Giblin, J..

6 recordsLinked to original sources

bioRxiv2026

Combination siRNA delivery as a therapeutic strategy for ADPKD

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic kidney disease worldwide, characterized by progressive cyst growth and inflammation, yet effective targeted therapies remain limited. Here we show that TMEM16A and MCP-1, key mediators of cyst-lining epithelial expansion and inflammatory macrophage recruitment respectively, are consistently upregulated in cyst-lining collecting duct (CD) epithelia across murine, porcine, and human ADPKD models. In human ADPKD patient cells, although individual silencing of TMEM16A or MCP-1 transcripts reduced cyst growth, combined silencing produced superior therapeutic efficacy, establishing the rationale for evaluating dual-target delivery. To achieve dual gene silencing in the kidneys, we delivered Tmem16a and Mcp-1 siRNA using peptide amphiphile micelles (PAMs), an ultrasmall nanoparticle platform that enables efficient renal targeting. To redirect siRNA-loaded PAMs to CD epithelia, we functionalized their surface with a CD-targeting peptide (CDM), which enabled preferential accumulation in cyst-lining CD epithelia. In an inducible Pkd1-deficient mouse model, co-delivery of CDMs loaded with Tmem16a and Mcp-1 siRNA reduced kidney enlargement, cystic burden, tubular injury, and macrophage infiltration, with efficacy exceeding non-targeted siRNA delivery at equivalent doses. CDM demonstrated enhanced uptake in primary human ADPKD patient-derived CD cells and dual gene silencing reduced target gene expression and cyst expansion, establishing translational relevance. These findings establish CD peptide-functionalized micelles as a route to cell-type-selective RNAi in the kidney, delivering siRNA to cyst-lining CD cells. Furthermore, because both targets, TMEM16A and MCP-1, are transcribed within CD cells, our siRNA-loaded CD-targeting micelles silence two drivers of cyst expansion, and their simultaneous suppression represents an effective therapeutic strategy for ADPKD.

bioengineering↗

bioRxiv2026

Collecting Duct-Targeted Lipid Nanoparticles Deliver Pkd2 mRNA to Restore Polycystin-2 and Attenuate ADPKD

Autosomal dominant polycystic kidney disease (ADPKD), a leading genetic cause of kidney failure, is caused by mutations in the PKD1 or PKD2 genes, resulting in functional polycystin 1 (PC1) or polycystin 2 (PC2) deficiency, and is characterized by progressive cyst expansion in the kidneys. However, no approved therapy directly restores polycystin expression, and current treatments target downstream pathways rather than the genetic defect. Gene replacement therapy offers a direct route to functional rescue, but efficient delivery to cyst-lining renal epithelia remains a major barrier. To meet this challenge, we developed a lipid nanoparticle (LNP) that incorporates a collecting duct (CD) targeting peptide (CD LNPs) to enable delivery of Pkd2 mRNA (CD-mPkd2) to renal CD epithelia, the predominant site of cyst origin. CD LNPs increased renal accumulation and targeted CD cells in vivo, outperforming non-targeted formulations. In a Pkd2-deficient mouse model, repeated administration of CD-mPkd2 induced reversal of established cystic disease, restored renal architecture, and reduced the fibrotic and inflammatory microenvironment characteristic of ADPKD. Furthermore, CD-mPkd2 was well tolerated without detectable off-target toxicity. Given that PC2 supplementation can attenuate disease in Pkd1-deficient models, we further demonstrate that a single dose of CD-mPkd2 reduces cyst burden and improves renal function across this distinct genetic background. These findings establish CD-mPkd2 as a potential therapeutic strategy for ADPKD across genetic backgrounds.

bioengineering↗

bioRxiv2022

High Throughput Detection of Capillary Stalling Events with Bessel Beam Two-Photon Microscopy

Disruptions in capillary flow have the potential to drive pathology across numerous diseases. But our understanding of the temporal and spatial dynamics of these events are hindered by slow volumetric imaging rates and the reliance on laborious manual analysis to process data. To address the challenges of increasing volumetric imaging speed, we use a custom-built Bessel beam two-photon microscope for efficient volumetric imaging of the capillary network. We demonstrate its ability to continuously monitor roughly 200 capillaries for capillary flow stoppages (i.e. stalling events) at a frame rate of approximately 0.5 Hz and develop a semi-automated correlation-based approach for identifying these stalling events. We applied our system and algorithm in a photothrombotic model of stroke and show elevated levels of stalling 1-week post-stroke in regions both within and outside of the stroke region, demonstrating that stalling may have impacts on stroke recovery that extend past the acute stage.

neuroscience↗

bioRxiv2022

High-throughput deep tissue two-photon microscopy at kilohertz frame rates

Strategies to image biological phenomena at millisecond time scales are generally technically challenging and suffer from compromises between imaging field-of-view, depth penetration and excitation efficiency in thick tissue. We present a simple and cost-effective solution that enables a conventional video-rate two-photon microscope (2PM) to perform 2D scanning at kilohertz frame rates, while preserving all the benefits of standard 2PM, which we demonstrate by imaging neurovascular dynamics in mouse brains.

bioengineering↗

bioRxiv2022

Measuring Capillary Flow Dynamics using Interlaced Two-Photon Volumetric Scanning

Two photon microscopy and optical coherence tomography (OCT) are two standard methods for measuring flow speeds of red blood cells in microvessels, particularly in animal models. However, traditional two photon microscopy lacks the depth of field to adequately capture the full volumetric complexity of the cerebral microvasculature and OCT lacks the specificity offered by fluorescent labeling. In addition, the traditional raster scanning technique utilized in both modalities requires a balance of image frame rate and field of view, which severely limits the study of RBC velocities in the microvascular network. Here, we overcome this by using a custom two photon system with an axicon based Bessel beam to obtain volumetric images of the microvascular network with fluorescent specificity. We combine this with a novel scan pattern that generates pairs of frames with short time delay sufficient for tracking red blood cell flow in capillaries. We track flow speed in 10 or more capillaries simultaneously at 1 Hz in a 237 m x 237m x 120 m volume and quantify both spatial and temporal variability in speed. We also demonstrate the ability to track flow speed changes around stalls in capillary flow.

bioengineering↗

bioRxiv2017

Reverse-Correlation Analysis of Mechanosensation Circuit in C. elegans Reveals Temporal and Spatial Encoding

Animals must integrate the activity of multiple mechanoreceptors to navigate complex environments. In Caenorhabditis elegans, the general roles of the mechanosensory neurons have been defined, but most studies involve end-point or single-time-point measurements, and thus lack dynamical information. Here, we formulate a set of unbiased quantitative characterizations of the mechanosensory system by using reverse correlation analysis on behavior. We use a custom tracking, selective illumination, and optogenetics platform to compare two mechanosensory systems: the gentle-touch (TRNs) and harsh-touch (PVD) circuits. This method yields characteristic linear filters that allow for prediction of behavioral responses. The resulting filters are consistent with previous findings, and further provide new insights on the dynamics and spatial encoding of the systems. Our results suggest that the tiled network of the gentle-touch neurons has better resolution for spatial encoding than the harsh-touch neurons. Additionally, linear-nonlinear models accurately predict behavioral responses based only on sensory neuron activity. Our results capture the overall dynamics of behavior induced by the activation of sensory neurons, providing simple transformations that quantitatively characterize these systems. Furthermore, this platform can be extended to capture the behavioral dynamics induced by any neuron or other excitable cells in the animal.\n\nAuthor SummaryAnimals constantly integrate the activity of neurons throughout their bodies to choose the most appropriate behavior. A key goal in quantitative neuroscience is to characterize and predict how neuronal circuits control and modulate behavior. C. elegans, a nematode with a fully mapped connectome, is an ideal model organism for elucidating the links between neuronal circuits and behavior. However, many studies relating activity in neurons to behavior rely on spontaneous behavior and lack information about their dynamics. In this study, we formulate unbiased quantitative characterizations of sensory neurons in C. elegans using with reverse correlation analysis with a white noise stimulus. We use optogenetics to stimulate body touch sensory neurons in freely moving worms, and provide quantitative descriptions that capture the dynamic transformations between sensory neuron activity and behavioral outputs. Our results are consistent with previous findings, and additionally provide new insights on the spatial encoding of these systems. Our system provides a simple platform for characterizing the behavioral output due to specific neurons, and can be extended to any excitable cell in the animal.

bioengineering↗