A5062814947- Advanced Fluorescence Microscopy Techniques
- Cardiac electrophysiology and arrhythmias
- Ion channel regulation and function
- Spectroscopy Techniques in Biomedical and Chemical Research
- Cell Image Analysis Techniques
- Optical Imaging and Spectroscopy Techniques
- Advanced Biosensing Techniques and Applications
- Single-cell and spatial transcriptomics
- Photoacoustic and Ultrasonic Imaging
- Photoreceptor and optogenetics research
- Connexins and lens biology
- Spectroscopy and Chemometric Analyses
- Cardiovascular Effects of Exercise
- Spectroscopy and Quantum Chemical Studies
- Protein Kinase Regulation and GTPase Signaling
- Advanced biosensing and bioanalysis techniques
- Neuroscience and Neuropharmacology Research
- Cardiomyopathy and Myosin Studies
- Orbital Angular Momentum in Optics
- Wound Healing and Treatments
- Lipid Membrane Structure and Behavior
- Bacterial biofilms and quorum sensing
- Pregnancy and preeclampsia studies
- Animal Disease Management and Epidemiology
- melanin and skin pigmentation
University of California, Irvine
2020-2025
Beckman Laser Institute and Medical Clinic
2024-2025
Universitat Politècnica de Catalunya
2012-2024
Irvine University
2024
Fluor (United States)
2020-2023
Northwest University
2022
Institut de Recerca Sant Joan de Déu
2017
Libin Cardiovascular Institute of Alberta
2013
University of Calgary
2013
University of Otago
2013
Cardiac ryanodine receptor (RyR2) gain-of-function mutations cause catecholaminergic polymorphic ventricular tachycardia, a condition characterized by prominent ectopy in response to catecholamine stress, which can be reproduced on exercise stress testing (EST). However, reports of sudden cardiac death (SCD) have emerged EST-negative individuals who loss-of-function (LOF) RyR2 mutations. The clinical relevance LOF including their pathogenic mechanism, diagnosis, and treatment are all...
Abstract Multiplexed mRNA profiling in the spatial context provides new information enabling basic research and clinical applications. Unfortunately, existing transcriptomics methods are limited due to either low multiplexing or complexity. Here, we introduce a spatialomics technology, termed Multi Omic Single-scan Assay with Integrated Combinatorial Analysis (MOSAICA), that integrates situ labeling of protein markers cells tissues combinatorial fluorescence spectral lifetime encoded probes,...
Phospholamban (PLN) is an inhibitor of cardiac sarco(endo)plasmic reticulum Ca²⁺ ATPase. PLN knockout (PLN-KO) enhances sarcoplasmic load and leak. Conversely, PLN-KO accelerates sequestration aborts arrhythmogenic spontaneous waves (SCWs). An important question whether these seemingly paradoxical effects exacerbate or protect against Ca²⁺-triggered arrhythmias.We investigate the impact on SCWs, triggered activities, stress-induced ventricular tachyarrhythmias (VTs) in a mouse model...
In several cellular systems, the phasor FLIM approach has shown existence of more than 2 components in same pixel, a typical example being free and bound NADH. order to properly quantify concentrations spatial distributions fluorescence associated with different molecular species we developed general method resolve 3 4 pixel using approach. The is based on law linear combination valid after transformation decay curves phasors for each image. principle, rule an arbitrary number components....
GSLab addresses the need for effective image analysis tools in fluorescence microscopy by providing an open-source platform that enhances traditional phasor with advanced features. Key capabilities include machine learning-based clustering, real-time monitoring, and quantitative unmixing of fluorescent species. Designed both commercial custom systems, provides researchers comprehensive lifetime spectral to tackle complex biological problems.
Beat-to-beat alternations in the amplitude of cytosolic Ca2+ transient (Ca2+ alternans) are thought to be primary cause cardiac alternans that can lead arrhythmias and sudden death. Despite its important role arrhythmogenesis, mechanism underlying remains poorly understood. Here, we investigated ryanodine receptor (RyR2), major release channel responsible for transients, alternans. Using a unique mouse model harboring suppression-of-function (SOF) RyR2 mutation (E4872Q), assessed effect...
Macromolecular crowding is crucial for cellular homeostasis. In vivo studies of macromolecular and water dynamics are needed to understand their roles in physiology fate determination. the lens essential normal optics, an understanding its regulation will help prevent cataract presbyopia. Here, we combine use nanoenvironmental sensor [6-acetyl-2-dimethylaminonaphthalene (ACDAN)] visualize with aquaporin 0 zebrafish mutants that disrupt regulation. Spectral phasor analysis ACDAN fluorescence...
A loss-of-function cardiac ryanodine receptor (RyR2) mutation, I4855M+/-, has recently been linked to a new disorder termed RyR2 Ca2+ release deficiency syndrome (CRDS) as well left ventricular noncompaction (LVNC). The mechanism by which causes CRDS extensively studied, but the underlying loss-of-function-associated LVNC is unknown. Here, we determined impact of CRDS-LVNC-associated RyR2-I4855M+/- mutation on structure and function.We generated mouse model expressing mutation. Histological...
Ca2+ alternans plays an essential role in cardiac that can lead to ventricular fibrillation, but the mechanism underlying remains undefined. Increasing evidence suggests results from alternations inactivation of RyR2 (ryanodine receptor 2). However, what inactivates and how leads are unknown.To determine CaM (calmodulin) on intact working mouse hearts.We used vivo local gene delivery approach alter function by directly injecting adenoviruses expressing CaM-wild type, a loss-of-function...
Fluorescence lifetime imaging microscopy (FLIM) may reveal subcellular spatial maps of key molecular species. Yet, such a quantitative picture life necessarily demands high photon budgets at every pixel under the current analysis paradigm, thereby increasing acquisition time and photodamage to sample. Motivated by recent developments in computational statistics, we provide direct means update our knowledge species different lifetimes from arrivals, while accounting for experimental features...
The cardiac Ca(2+) release channel (ryanodine receptor, RyR2) plays an essential role in excitation-contraction coupling muscle cells. Effective and stable critically depends not only on the expression of RyR2, but also its distribution. Despite importance, little is known about distribution organization RyR2 living To study cardiomyocytes, we generated a knock-in mouse model expressing GFP-tagged (GFP-RyR2). Confocal imaging live ventricular myocytes isolated from GFP-RyR2 heart revealed...
The phasor approach is used in fluorescence lifetime imaging microscopy for several purposes, notably to calculate the metabolic index of single cells and tissues. An important feature that it a fit-free method allowing immediate easy interpret analysis images. In recent paper, we showed three or four intensity fractions exponential components can be resolved each pixel an image by using simple algebra, provided component phasors are known. This only makes use rule linear combination rather...
FRET microscopy experiments demonstrate supramolecular assembly of teixobactin molecules on Bacillus subtilis , providing further evidence that is a antibiotic.
Fluorescence lifetime imaging microscopy (FLIM) has become a standard tool in the quantitative characterization of subcellular environments. However, FLIM analyses face several challenges. First, spatial correlations between pixels are often ignored as signal from individual is analyzed independently thereby limiting resolution. Second, existing methods deduce photon ratios instead absolute maps. Next, number fluorophore species contributing to unknown, while excited state lifetimes with <1...
Reduced protein expression of the cardiac ryanodine receptor type 2 (RyR2) is thought to affect susceptibility stress-induced ventricular tachyarrhythmia (VT) and alternans, but direct evidence for role RyR2 in VT alternans lacking. Here, we used a mouse model (crrm1) that expresses reduced level determine impact on VT, hypertrophy, sudden death. Electrocardiographic analysis revealed after injection relatively high doses caffeine epinephrine (agents commonly stress test), wild-type (WT)...
Hyperspectral imaging (HSI) is a paramount technique in biomedical science, however, unmixing and quantification of each spectral component challenging task. Traditional relies on algorithms that need spectroscopic parameters from the fluorescent species sample. The phasor-based multi-harmonic method requires only empirical measurement pure to compute pixel-wise photon fraction every component. Using simulations, we demonstrate feasibility approach for up 5 components explore use adding 6th...
PKA (protein kinase A)-mediated phosphorylation of cardiac RyR2 (ryanodine receptor 2) has been extensively studied for decades, but the physiological significance remains poorly understood. Recent determination high-resolution 3-dimensional structure in complex with CaM (calmodulin) reveals that major site RyR2, serine-2030 (S2030), is located within a structural pathway CaM-dependent inactivation RyR2. This novel insight points to possible role which underlies termination Ca2+ release and...
We present an automatic image processing framework to study moving intracellular structures from live cell fluorescence microscopy. The system includes the identification of static and dynamic time-lapse images using data clustering as well trajectory objects with a probabilistic tracking algorithm. method has been successfully applied mitochondrial movement in neurons. approach provides excellent performance under different experimental conditions is robust common sources noise including...
ABSTRACT Bovine leukemia virus (BLV) is a B-lymphotropic oncogenic retrovirus of the genus Deltaretrovirus that infects dairy cattle worldwide and causative agent enzootic bovine leukosis. BLV demonstrates remarkably low efficiency in infecting cells via free viral particles derived from infected B cells, as virions are rarely detected bloodstream cattle. However, transmission efficacy significantly increases upon establishment direct cell-to-cell interactions. Syncytium formation assays...
This study addresses challenges in Optical Metabolic Imaging due to dim signals, overlapping spectra, and similar lifetimes of NADH FAD autofluorescent molecules. A Phasor-based S-FLIM-SHG microscope is introduced, enabling simultaneous acquisition Hyperspectral (HSI), Fluorescence Lifetime Microscopy (FLIM), Second Harmonic Generation imaging (SHG). The microscope's design efficiently detects scattered photons from complex samples it particularly competent at detection SHG signal. novel...