A5001215925- Advanced Fluorescence Microscopy Techniques
- Estrogen and related hormone effects
- Receptor Mechanisms and Signaling
- Alzheimer's disease research and treatments
- bioluminescence and chemiluminescence research
- Advanced Biosensing Techniques and Applications
- Optical Imaging and Spectroscopy Techniques
- Computational Drug Discovery Methods
- Neuropeptides and Animal Physiology
- Cell Image Analysis Techniques
- Glioma Diagnosis and Treatment
- RNA Interference and Gene Delivery
- Hedgehog Signaling Pathway Studies
- DNA and Nucleic Acid Chemistry
- Neurotransmitter Receptor Influence on Behavior
- Lipid Membrane Structure and Behavior
- Nuclear Receptors and Signaling
- Cancer Genomics and Diagnostics
- Viral Infectious Diseases and Gene Expression in Insects
- Effects and risks of endocrine disrupting chemicals
- Bioinformatics and Genomic Networks
- Photochromic and Fluorescence Chemistry
- Organic Chemistry Cycloaddition Reactions
- Spectroscopy Techniques in Biomedical and Chemical Research
- Neuroinflammation and Neurodegeneration Mechanisms
Karolinska Institutet
2019-2025
Karolinska University Hospital
2024
Hokkaido University
2010-2018
OLIG2-expressing tumor stem cells have been shown to drive recurrence in Sonic Hedgehog (SHH)-subgroup medulloblastoma (MB) and patients urgently need specific therapies target this cell population. Here, we investigate the therapeutic potential of brain-penetrant orally bioavailable, OLIG2 inhibitor CT-179, using SHH-MB explant organoids, PDX GEM models. We find that CT-179 disrupts dimerization, phosphorylation DNA binding alters cell-cycle kinetics, increasing differentiation apoptosis....
Abstract Hyperosmotic stress activates in live cells numerous processes and also promotes intracellular protein/RNA aggregation phase separation. However, the time course extent of these changes remain largely uncharacterized. To investigate dynamic macromolecular crowding (MMC) induced by hyperosmotic cells, we used fluorescence lifetime imaging microscopy correlation spectroscopy (FCS) to quantify local environment measuring diffusion monomeric enhanced green fluorescent protein (eGFP),...
Glucocorticoid receptor (GRα) is a well-known ligand-dependent transcription-regulatory protein. The classic view that unliganded GRα resides in the cytoplasm, relocates to nucleus after ligand binding, and then associates with specific DNA sequence, namely glucocorticoid response element (GRE), activate gene as homodimer. It still puzzle, however, whether forms homodimer cytoplasm or before binding that. To quantify homodimerization of GRα, we constructed spectrally different fluorescent...
Functional fluorescence microscopy imaging (fFMI), a time-resolved (21 μs/frame) confocal technique without scanning, is developed for quantitative characterization of fast reaction-transport processes in solution and live cells. The method based on massively parallel correlation spectroscopy (FCS). Simultaneous excitation fluorescent molecules multiple spots the focal plane achieved using diffractive optical element (DOE). Fluorescence from DOE-generated 1024 illuminated detected...
Several lines of evidence suggest that a characteristic the neuropathology Alzheimer's disease (AD) is aggregation amyloid beta peptides (Aβ), fragments human precursor protein (hAPP). The dominating species are Aβ40 and Aβ42 with 40 42 amino acids, respectively. Aβ initially forms soluble oligomers continue to expand protofibrils, suggestively neurotoxic intermediates, thereafter turn into insoluble fibrils markers disease. Using powerful tool pharmacophore simulation, we selected small...
Aggregated forms of the amyloid-β (Aβ) peptides which form protofibrils and fibrils in brain are signatures Alzheimer's disease (AD). Aggregates also recognized by microglia, early phases may be protective later contribute to pathology. We have identified several small molecules, decoys interfere with Aβ oligomerization induce other aggregation trajectories leading aggregated macrostructures non-toxic.
Hemoglobin (Hb), a life-sustaining and highly abundant erythrocyte protein, is not readily fluorescent. A few studies have already reported Two-Photon Excited Fluorescence (TPEF) of Hb, however, the mechanisms through which Hb becomes fluorescent upon interaction with ultrashort laser pulses are completely understood. Here, we characterized photophysically this on thin film erythrocytes using fluorescence spectroscopy single-photon/two-photon absorption, UV-VIS single-photon absorption...
Standard neuropathologic analysis of Alzheimer's brain relies on traditional fluorescence microscopy, which suffers from limited spatial resolution due to light diffraction. As a result, it fails reveal intricate details amyloid plaques. While electron microscopy (EM) offers higher resolution, its extensive sample preparation, involving fixation, dehydration, embedding, and sectioning, can introduce artifacts distortions in the complex tissue. Moreover, EM lacks molecular specificity has...
Glucocorticoid receptor α (GR) binds to the promoter regions of target genes as a homodimer and activates its transcriptional process. Though homodimerization is thought be initial essential process, dissociation constant for GR remains controversial. To quantify (enhanced green fluorescence protein) EGFP–(glucocorticoid receptor) GR, particle brightness in lysates from single cell was estimated fraction homodimeric EGFP–GR using correlation spectroscopy microwells. Fitting data with...
Recurrence is the primary life-threatening complication for medulloblastoma (MB). In Sonic Hedgehog (SHH)-subgroup MB, OLIG2-expressing tumor stem cells drive recurrence. We investigated anti-tumor potential of small-molecule OLIG2 inhibitor CT-179, using SHH-MB patient-derived organoids, xenograft (PDX) tumors and mice genetically-engineered to develop SHH-MB. CT-179 disrupted dimerization, DNA binding phosphorylation altered cell cycle kinetics
Naltrexone (NTX), a homolog of the opiate antidote naloxone, is an orally active long-acting general opioid receptor antagonist used in treatment dependence. NTX also found to relieve craving for alcohol and one few FDA-approved medications use disorder (AUD). While it was early on established that acts by blocking binding endogenous peptide ligands released alcohol, experimental evidence emerged could not be fully accounted this explanation alone, suggesting may have additional modes...
Significance Transcription factors in the bHLH family are potentially relevant for tumor growth. Activation requires homodimerization or heterodimerization. Thus, dimerization step is a likely significant drug target. The oligodendrocyte transcription factor 2 (OLIG2) overexpressed gliomas. Here, we developed fluorescence cross-correlation spectroscopy protocol to examine 10 compounds selected using pharmacophore-based computational strategy targeting OLIG2 dimerization. We showed that...
Compartmentalization and integration of molecular processes through diffusion are basic mechanisms which cells perform biological functions. To characterize these in live cells, quantitative ultrasensitive analytical methods with high spatial temporal resolution needed. Here, we present scanning-free confocal microscopy single-molecule sensitivity, (∼10 μs/frame), fluorescence lifetime imaging capacity, developed by integrating massively parallel correlation spectroscopy (mpFCS/FLIM);...
Glucocorticoid receptor (GR) is a hormone-activated transcription regulatory protein involved in metabolism as well adrenocortical responses to psychosocial stress. Ligand-activated GR localizes the nucleus, where homodimers regulate gene via direct binding glucocorticoid response elements (GREs). The role of transcriptional activation has not yet been elucidated. In this study, we determined concentration homodimer, and its dissociation constant (Kd), at single-cell level, by using...
Nucleocytoplasmic transport of transcription factors is vital for normal cellular function, and its breakdown a major contributing factor in many diseases. The glucocorticoid receptor (GR) an evolutionarily conserved, ligand-dependent that regulates homeostasis response to stress important target therapeutics inflammation cancer. In unstimulated cells, the GR resides cytoplasm bound other molecules large multiprotein complex. Upon stimulation with endogenous or synthetic ligands,...
Biochemical data have shown aggregated G protein-coupled receptor 37 (GPR37) in the cytoplasm and Lewy bodies Parkinson's disease (PD). Properly folded GPR37 at plasma membrane appears to be neuroprotective. GPR37, its homologue GPR37L1, are orphan receptors their homo- hetero-dimers not been established. We therefore examined GPR37L1 dimerization extended studies of multimerization live cells. In this study, we investigated cells using three quantitative imaging methods: Fluorescence...
Quantitative confocal fluorescence microscopy imaging without scanning is developed for the study of fast dynamical processes. The method relies on use massively parallel Fluorescence Correlation Spectroscopy (mpFCS). Simultaneous excitation fluorescent molecules across specimen achieved by passing a single laser beam through Diffractive Optical Element (DOE) to generate quadratic illumination matrix 32×32 light sources. from 1024 illuminated spots detected in arrangement matching detector...
Quantitative confocal fluorescence microscopy imaging without scanning is developed for the study of fast dynamical processes. The method relies on use massively parallel Fluorescence Correlation Spectroscopy (mpFCS). Simultaneous excitation fluorescent molecules across specimen achieved by passing a single laser beam through Diffractive Optical Element (DOE) to generate quadratic illumination matrix 32·32 light sources. from 1024 illuminated spots detected in arrangement matching detector...
Abstract Thioflavin-T (THT) is a common and indispensable tool for the study of amyloid pathologies protein aggregation, both in vitro histological samples. In this we expand use THT beyond its canonical usage staining plaques demonstrate novel as an easy rapid stain comparable to fluorescent Nissl staining, allowing clear discernment neuronal cell bodies also nucleoli fixed tissue live cells. We believe that value any lab studies central nervous system (CNS) tissues. Furthermore, show could...