The activity of the light-oxygen-voltage/helix-turn-helix (LOV-HTH) photoreceptor EL222 is regulated through protein-protein and protein-DNA interactions, both triggered by photo-excitation of its flavin mononucleotide (FMN) cofactor. To gain molecular-level insight into the photocycle of EL222, we applied complementary methods: macromolecular X-ray crystallography (MX), nuclear magnetic resonance (NMR) spectroscopy, optical spectroscopies (infrared and UV-visible), molecular dynamics/metadynamics (MD/metaD) simulations, and protein engineering using noncanonical amino acids. Kinetic experiments provided evidence for two distinct EL222 conformations (lit1 and lit2) that become sequentially populated under illumination. These two lit states were assigned to covalently bound N5 protonated, and noncovalently bound hydroquinone forms of FMN, respectively. Only subtle structural differences were observed between the monomeric forms of all three EL222 species (dark, lit1, and lit2). While the dark state is largely monomeric, both lit states undergo monomer-dimer exchange. Furthermore, molecular modeling revealed differential dynamics and interdomain separation times arising from the three FMN states (oxidized, adduct, and reduced). Unexpectedly, all three EL222 species can associate with DNA, but only upon blue-light irradiation, a high population of stable complexes is obtained. Overall, we propose a model of EL222 activation where photoinduced changes in the FMN moiety shift the population equilibrium toward an open conformation that favors self-association and DNA-binding.
- MeSH
- Bacterial Proteins chemistry metabolism MeSH
- DNA-Binding Proteins chemistry metabolism MeSH
- DNA * chemistry metabolism MeSH
- Flavin Mononucleotide * chemistry metabolism MeSH
- Flavins chemistry metabolism MeSH
- Kinetics MeSH
- Protein Conformation MeSH
- Crystallography, X-Ray MeSH
- Oxidation-Reduction * MeSH
- Molecular Dynamics Simulation MeSH
- Light * MeSH
- Thermosynechococcus metabolism MeSH
- Transcription Factors metabolism chemistry MeSH
- Protein Binding MeSH
- Publication type
- Journal Article MeSH
INTRODUCTION: Multiple Sclerosis (MS), a debilitating central nervous system (CNS) disorder, is characterized by inflammation, demyelination, and neuronal degeneration. Despite advancements in immunomodulatory treatments, neuroprotective or restorative strategies remain inadequate. Our research is focusing on the potential of the positive allosteric modulator of AMPA receptors (AMPA-PAM), PF4778574, in addressing MS symptoms. METHODS: We utilized the MOG35-55 induced experimental autoimmune encephalomyelitis (EAE) model in C57BL6J mice to examine PF4778574's therapeutic and prophylactic efficacy. Our comprehensive approach included clinical scoring, optical coherence tomography (OCT), optomotor response (OMR) and histological assessments. Additionally, we explored the effects of PF4778574 in comparison and in combination with the immunomodulatory agent fingolimod, and investigated the impact on Cuprizone induced toxic demyelination. RESULTS: Prophylactic administration of PF4778574 showed notable improvement in clinical EAE indices and reduction in neuronal loss. While it did not diminish microglial activity, it reduced demyelinated areas in optic nerves and in the corpus callosum. Both PF4778574 and fingolimod significantly enhanced clinical EAE scores and decreased demyelination. However, their combination did not yield additional benefits. In the cuprizone model, PF4778574 increased oligodendrocyte precursor and mature myelin-forming cells, suggesting a pro-remyelinating effect. DISCUSSION: PF4778574 demonstrates promise in mitigating EAE effects, especially in terms of clinical disability and demyelination. These results suggest AMPA-PAMs as potential targets of interest for MS treatment beyond immunomodulatory approaches.
- MeSH
- Allosteric Regulation MeSH
- Receptors, AMPA * metabolism MeSH
- Demyelinating Diseases drug therapy metabolism MeSH
- Encephalomyelitis, Autoimmune, Experimental * drug therapy metabolism immunology MeSH
- Fingolimod Hydrochloride pharmacology therapeutic use MeSH
- Disease Models, Animal MeSH
- Mice, Inbred C57BL * MeSH
- Mice MeSH
- Multiple Sclerosis * drug therapy metabolism immunology MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Measuring the transduction of electrical signals within neurons is a key capability in neuroscience. Fluorescent voltage sensitive dyes (VSDs) were early tools that complemented classical electrophysiology by enabling the optical recording of membrane potential changes from many cells simultaneously. Recent advances in the VSD field have led to bright and highly sensitive sensors that can be targeted to the desired cell populations in live brain tissue. Despite this progress, recently, protein-based genetically encoded voltage indicators (GEVIs) have become the go-to tools for targeted voltage imaging in complex environments. In this Perspective, we summarize progress in developing targetable VSDs, discuss areas where these synthetic sensors are or could become relevant, and outline hurdles that need to be overcome to promote the routine use of targetable VSDs in neuroscience research.
- MeSH
- Action Potentials physiology drug effects MeSH
- Fluorescent Dyes MeSH
- Humans MeSH
- Membrane Potentials physiology MeSH
- Neurons * physiology MeSH
- Voltage-Sensitive Dye Imaging methods trends MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
- Research Support, N.I.H., Extramural MeSH
Quantitative genomic mapping of DNA damage may provide insights into the underlying mechanisms of damage and repair. Sequencing based approaches are bound to the limitations of PCR amplification bias and read length which hamper both the accurate quantitation of damage events and the ability to map them to structurally complex genomic regions. Optical Genome mapping in arrays of parallel nanochannels allows physical extension and genetic profiling of millions of long genomic DNA fragments, and has matured to clinical utility for characterization of complex structural aberrations in cancer genomes. Here we present a new mapping modality, Repair-Assisted Damage Detection - Optical Genome Mapping (RADD-OGM), a method for single-molecule level mapping of DNA damage on a genome-wide scale. Leveraging ultra-long reads to assemble the complex structure of a sarcoma cell-line genome, we mapped the genomic distribution of oxidative DNA damage, identifying regions more susceptible to DNA oxidation. We also investigated DNA repair by allowing cells to repair chemically induced DNA damage, pinpointing locations of concentrated repair activity, and highlighting variations in repair efficiency. Our results showcase the potential of the method for toxicogenomic studies, mapping the effect of DNA damaging agents such as drugs and radiation, as well as following specific DNA repair pathways by selective induction of DNA damage. The facile integration with optical genome mapping enables performing such analyses even in highly rearranged genomes such as those common in many cancers, a challenging task for sequencing-based approaches.
- MeSH
- Bromates toxicity MeSH
- Humans MeSH
- Chromosome Mapping * instrumentation methods MeSH
- Microfluidic Analytical Techniques * instrumentation methods MeSH
- Cell Line, Tumor MeSH
- Nanotechnology * instrumentation methods MeSH
- DNA Repair genetics MeSH
- Oxidative Stress drug effects genetics MeSH
- DNA Damage * genetics MeSH
- Gene Expression Regulation MeSH
- Gene Expression Profiling MeSH
- Toxicogenetics * instrumentation methods MeSH
- DNA Copy Number Variations MeSH
- Single Molecule Imaging * instrumentation methods MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Single-photon optogenetics enables precise, cell-type-specific modulation of neuronal circuits, making it a crucial tool in neuroscience. Its miniaturization in the form of fully implantable wide-field stimulator arrays enables long-term interrogation of cortical circuits and bears promise for brain-machine interfaces for sensory and motor function restoration. However, achieving selective activation of functional cortical representations poses a challenge, as studies show that targeted optogenetic stimulation results in activity spread beyond one functional domain. While recurrent network mechanisms contribute to activity spread, here we demonstrate with detailed simulations of isolated pyramidal neurons from cats of unknown sex that already neuron morphology causes a complex spread of optogenetic activity at the scale of one cortical column. Since the shape of a neuron impacts its optogenetic response, we find that a single stimulator at the cortical surface recruits a complex spatial distribution of neurons that can be inhomogeneous and vary with stimulation intensity and neuronal morphology across layers. We explore strategies to enhance stimulation precision, finding that optimizing stimulator optics may offer more significant improvements than the preferentially somatic expression of the opsin through genetic targeting. Our results indicate that, with the right optical setup, single-photon optogenetics can precisely activate isolated neurons at the scale of functional cortical domains spanning several hundred micrometers.
- MeSH
- Cats MeSH
- Models, Neurological MeSH
- Cerebral Cortex physiology cytology MeSH
- Neurons physiology MeSH
- Optogenetics * methods MeSH
- Pyramidal Cells physiology MeSH
- Photic Stimulation methods MeSH
- Animals MeSH
- Check Tag
- Cats MeSH
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
STUDY QUESTION: Can oocyte functionality be assessed by observing changes in their intracytoplasmic lipid droplets (LDs) profiles? SUMMARY ANSWER: Lipid profile changes can reliably be detected in human oocytes; lipid changes are linked with maternal age and impaired developmental competence in a mouse model. WHAT IS KNOWN ALREADY: In all cellular components, lipid damage is the earliest manifestation of oxidative stress (OS), which leads to a cascade of negative consequences for organelles and DNA. Lipid damage is marked by the accumulation of LDs. We hypothesized that impaired oocyte functionality resulting from aging and associated OS could be assessed by changes in LDs profile, hereafter called lipid fingerprint (LF). STUDY DESIGN, SIZE, DURATION: To investigate if it is possible to detect differences in oocyte LF, we subjected human GV-stage oocytes to spectroscopic examinations. For this, a total of 48 oocytes derived from 26 young healthy women (under 33 years of age) with no history of infertility, enrolled in an oocyte donation program, were analyzed. Furthermore, 30 GV human oocytes from 12 women were analyzed by transmission electron microscopy (TEM). To evaluate the effect of oocytes' lipid profile changes on embryo development, a total of 52 C57BL/6 wild-type mice and 125 Gnpat+/- mice were also used. PARTICIPANTS/MATERIALS, SETTING, METHODS: Human oocytes were assessed by label-free cell imaging via coherent anti-Stokes Raman spectroscopy (CARS). Further confirmation of LF changes was conducted using spontaneous Raman followed by Fourier transform infrared (FTIR) spectroscopies and TEM. Additionally, to evaluate whether LF changes are associated with developmental competence, mouse oocytes and blastocysts were evaluated using TEM and the lipid dyes BODIPY and Nile Red. Mouse embryonic exosomes were evaluated using flow cytometry, FTIR and FT-Raman spectroscopies. MAIN RESULTS AND THE ROLE OF CHANCE: Here we demonstrated progressive changes in the LF of oocytes associated with the woman's age consisting of increased LDs size, area, and number. LF variations in oocytes were detectable also within individual donors. This finding makes LF assessment a promising tool to grade oocytes of the same patient, based on their quality. We next demonstrated age-associated changes in oocytes reflected by lipid peroxidation and composition changes; the accumulation of carotenoids; and alterations of structural properties of lipid bilayers. Finally, using a mouse model, we showed that LF changes in oocytes are negatively associated with the secretion of embryonic exosomes prior to implantation. Deficient exosome secretion disrupts communication between the embryo and the uterus and thus may explain recurrent implantation failures in advanced-age patients. LIMITATIONS, REASONS FOR CAUTION: Due to differences in lipid content between different species' oocytes, the developmental impact of lipid oxidation and consequent LF changes may differ across mammalian oocytes. WIDER IMPLICATIONS OF THE FINDINGS: Our findings open the possibility to develop an innovative tool for oocyte assessment and highlight likely functional connections between oocyte LDs and embryonic exosome secretion. By recognizing the role of oocyte LF in shaping the embryo's ability to implant, our original work points to future directions of research relevant to developmental biology and reproductive medicine. STUDY FUNDING/COMPETING INTEREST(S): This research was funded by National Science Centre of Poland, Grants: 2021/41/B/NZ3/03507 and 2019/35/B/NZ4/03547 (to G.E.P.); 2022/44/C/NZ4/00076 (to M.F.H.) and 2019/35/N/NZ3/03213 (to Ł.G.). M.F.H. is a National Agency for Academic Exchange (NAWA) fellow (GA ULM/2019/1/00097/U/00001). K.F. is a Diamond Grant fellow (Ministry of Education and Science GA 0175/DIA/2019/28). The open-access publication of this article was funded by the Priority Research Area BioS under the program "Excellence Initiative - Research University" at the Jagiellonian University in Krakow. The authors declare no competing interest. TRIAL REGISTRATION NUMBER: N/A.
- MeSH
- Adult MeSH
- Embryonic Development physiology MeSH
- Humans MeSH
- Lipid Droplets metabolism MeSH
- Lipid Metabolism MeSH
- Mice, Inbred C57BL * MeSH
- Mice MeSH
- Oocytes * metabolism MeSH
- Oxidative Stress MeSH
- Spectrum Analysis, Raman MeSH
- Aging metabolism MeSH
- Microscopy, Electron, Transmission MeSH
- Maternal Age MeSH
- Animals MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
MicroRNAs (miRNAs) are small non-coding RNAs (18-22 nucleotides) that regulate gene expression and are associated with various diseases, including Laryngeal Cancer (LCa), which has a high mortality rate due to late diagnosis. Traditional methods for miRNA detection present several drawbacks (time-consuming steps, high cost and high false positive rate). Early-stage diagnosis and selective detection of miRNAs remain challenging. This study proposes a 3D flexible biosensor that combines nanofibers (NFs), gold nanoparticles (AuNPs), and an inverse molecular sentinel (iMS) for enzyme-free, SERS-based detection of miRNA-223-3p, evaluated as a potential LCa biomarker. The electrospun flexible nanofibers decorated with AuNPs enhance Raman signal. Selective detection of miRNA-223-3p is achieved by immobilizing an iMS-DNA probe labeled with a Raman reporter (Cyanine 3) on the AuNPs. The iMS distinctive stem-and-loop structure undergoes a conformational change upon interaction with the miRNA-223-3p, producing an "on to off" SERS signal. The proposed sensor demonstrated a linear detection range from 10 to 250 fM, with a limit of detection (LOD) of 19.50 ± 0.05 fM. The sensor selectivity was confirmed by analyzing the SERS signal behaviour in the presence of both Non-complementary miRNA and miRNA with three mismatched base pairs. This easily fabricable sensor requires no amplification and offers key advantages, including sensitivity, flexibility, and cost-effectiveness.
- MeSH
- Biosensing Techniques * methods MeSH
- Early Detection of Cancer methods MeSH
- Metal Nanoparticles * chemistry MeSH
- Humans MeSH
- Limit of Detection MeSH
- MicroRNAs * analysis genetics MeSH
- Laryngeal Neoplasms * diagnosis genetics MeSH
- Nanofibers * chemistry MeSH
- Spectrum Analysis, Raman * methods MeSH
- Gold * chemistry MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Autoři popisují klinický případ pacientky s metastazujícím melanomem, u níž se v samém počátku cílené léčby enkorafenibem a binimetinibem objevila oční toxicita ve formě bilaterálního odloučení zevních vrstev sítnice. Subjektivní obtíže se zrakem odezněly do 2 měsíců a kontrolní OCT potvrdilo reparaci odloučení. Cílená léčba dabrafenibem a trametinibem v další linii léčby nevykázala příznaky oční toxicity. Diskutována je oční toxicita cílené léčby u melanomu, její typy, závažnost a management. Při každé návštěvě pacienta léčeného cílenou léčbou BRAF a MEK inhibitorem byl měl být pacient tázán na subjektivní obtíže se zrakem. Pro včasnou a správnou diagnostiku oční toxicity je nutná úzká spolupráce se specialistou v oboru oftalmologie.
The authors describe a clinical case of a patient with metastatic melanoma treated with the targeted therapy by encorafenib and binimetinib. In the very beginning of the treatment, the ocular toxicity in the form of the bilateral detachment of the outer retinal layers was detected. Subjective symptoms disappeared in 2 months and follow-up OCT confirmed the restoration of the detachment. The targeted therapy with dabrafenib and trametinib in the subsequent line of the treatment was not complicated by the symptoms of the ocular toxicity. The article discusses the ocular toxicity of the targeted therapy in melanoma, its types, grading, and management. During each patient's visit in case the patient is treated with the targeted therapy by BRAF and MEK inhibitor, the patient should be asked about any subjective vision impairment. The close cooperation with the ophthalmology specialist is crucial for the early and correct diagnosis of the ocular toxicity.
- MeSH
- Molecular Targeted Therapy adverse effects MeSH
- Middle Aged MeSH
- Humans MeSH
- Melanoma * diagnosis drug therapy MeSH
- Mitogen-Activated Protein Kinase Kinases antagonists & inhibitors adverse effects therapeutic use MeSH
- Retinal Diseases diagnosis therapy MeSH
- Drug-Related Side Effects and Adverse Reactions MeSH
- Tomography, Optical Coherence MeSH
- Antineoplastic Agents administration & dosage therapeutic use toxicity MeSH
- Antineoplastic Combined Chemotherapy Protocols administration & dosage adverse effects therapeutic use MeSH
- Proto-Oncogene Proteins B-raf antagonists & inhibitors administration & dosage therapeutic use MeSH
- Toxic Optic Neuropathy diagnosis veterinary MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Female MeSH
- Publication type
- Case Reports MeSH
Ramanovu spektroskopii lze v chemii použít nejen k určování chemického složení, ale také pro získávání dalších informací o struktuře materiálu. Ve spektrech semikrystalických polymerů lze nalézt vzájemně odlišné pásy charakteristické pro krystalickou nebo amorfní fázi, stanovit z nich krystalinitu a z ní odhadnout míru degradace polymeru. V předložené studii byly vyhodnoceny změny raménka pásu na vlnočtu 1733 cm−1 v Ramanových spektrech vlákna z poly(p-dioxanonu) podrobeného hydrolytické degradaci. Pro různě dlouhé doby degradace byly vypočteny obsahy ploch pod raménkem tohoto pásu a též byl proveden jeho modelový rozklad na předpokládané píky krystalické a amorfní fáze. Obsahy ploch pod raménkem i parametry modelových píků byly porovnány s hodnotami krystalinity získanými pomocí diferenční skenovací kalorimetrie, přičemž bylo dosaženo dobré shody. Tato práce ukazuje příklad využití Ramanovy spektroskopie při studiu hydrolytické degradace polymerů.
Raman spectroscopy can be used in chemistry not just to determine chemical composition, but also to obtain further information on the material structure. In the spectra of semi-crystalline polymers, distinct bands characteristic of the crystalline or the amorphous phase can be found, the degree of crystallinity determined from them, and the degree of polymer degradation estimated from the crystallinity. In the present study, changes in the 1733 cm−1 band shoulder in Raman spectra of poly(p-dioxanone) fibres subjected to hydrolytic degradation were evaluated. For different degradation periods, the areas under the shoulder of this band were calculated and a model deconvolution of this band into assumed crystalline and amorphous peaks was also performed. The areas under the shoulder, as well as the model peaks' parameters, were compared with the crystallinity values obtained by differential scanning calorimetry, achieving a good agreement. This work shows an example of using Raman spectroscopy when studying the hydrolytic degradation of polymers.
Introduction: Rheumatoid arthritis (RA) is a chronic autoimmune disease with unknown cause. It mainly affects joints and, without proper treatment, negatively impacts their movement, causes painful deformities, and reduces the patients' quality of life. Current treatment options consist of various types of disease-modifying antirheumatic drugs (DMARDs), however 20-30% of patients are partially resistant to them. Therefore, development of new drugs is necessary. Possible option are compounds exhibiting their action via endocannabinoid system, which plays an important role in pain and inflammation modulation. One such compound - cannabidiol (CBD) has already been shown to attenuate synovitis in animal model of RA in in vivo studies. However, it has low bioavailability due to its low water solubility and lipophilicity. This issue can be addressed by preparation of a lipid containing formulation targeting lymphatic system, another route of absorption in the body. Materials and Methods: CBD-containing emulsion was prepared by high-shear homogenization and its droplet size distribution was analysed by optical microscopy. The relative oral bioavailability compared to oil solution as well as total availability of CBD were assessed in a cross-over study in rats and absorption of CBD via lymphatic system was observed. The effect of CBD on the animal model of RA was determined. Results: Compared to oil solution, the emulsion exhibited higher absolute oral bioavailability. Significant lymphatic transport of CBD was observed in all formulations and the concentrations in lymph were calculated. The therapeutic effect of CBD on RA was confirmed as an improvement in clinical symptoms as well as morphological signs of disease activity were observed during the study. Conclusion: In this work, we prepared a simple stable emulsion formulation, determined the pharmacokinetic parameters of CBD and calculated its absolute bioavailability in rats. Moreover, we successfully tested the pharmaceutical application of such a formulation and demonstrated the positive effect of CBD in an animal model of RA.
- MeSH
- Administration, Oral MeSH
- Pain drug therapy MeSH
- Emulsions MeSH
- Cannabidiol * pharmacology chemistry MeSH
- Cross-Over Studies MeSH
- Rats MeSH
- Quality of Life MeSH
- Arthritis, Rheumatoid * drug therapy MeSH
- Water MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH