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BioRxiv : the Preprint Server For... Mar 2024Primary angle closure glaucoma (PACG) affects more than 20 million people worldwide, with an increased prevalence in south-east Asia. In a prior haplotype-based GWAS, we...
Primary angle closure glaucoma (PACG) affects more than 20 million people worldwide, with an increased prevalence in south-east Asia. In a prior haplotype-based GWAS, we identified a novel genic region, significantly associated with PACG. In the current study, we have extended our perception of involvement in glaucomatous neurodegeneration in a zebrafish model, through investigating phenotypic consequences pertinent to retinal degeneration upon knockdown of cntnap5 by translation-blocking morpholinos. While cntnap5 knockdown was successfully validated using an antibody, immunofluorescence followed by western blot analyses in cntnap5-morphant (MO) zebrafish revealed increased expression of acetylated tubulin indicative of perturbed cytoarchitecture of retinal layers. Moreover, significant loss of Nissl substance is observed in the neuro-retinal layers of cntnap5-MO zebrafish eye, indicating neurodegeneration. Additionally, in spontaneous movement behavioural analysis, cntnap5-MO zebrafish have a significantly lower average distance traversed in light phase compared to mismatch-controls, whereas no significant difference was observed in the dark phase, corroborating with vision loss in the cntnap5-MO zebrafish. This study provides the first direct functional evidence of a putative role of in visual neurodegeneration.
PubMed: 38903068
DOI: 10.1101/2024.03.14.583830 -
Science Advances Jun 2024Noise-induced hearing loss (NIHL) is a common sensorineural hearing impairment that lacks U.S. Food and Drug Administration-approved drugs. To fill the gap in effective...
Noise-induced hearing loss (NIHL) is a common sensorineural hearing impairment that lacks U.S. Food and Drug Administration-approved drugs. To fill the gap in effective screening models, we used an in silico transcriptome-based drug screening approach, identifying 22 biological pathways and 64 potential small molecule treatments for NIHL. Two of these, afatinib and zorifertinib [epidermal growth factor receptor (EGFR) inhibitors], showed efficacy in zebrafish and mouse models. Further tests with EGFR knockout mice and EGF-morpholino zebrafish confirmed their protective role against NIHL. Molecular studies in mice highlighted EGFR's crucial involvement in NIHL and the protective effect of zorifertinib. When given orally, zorifertinib was found in the perilymph with favorable pharmacokinetics. In addition, zorifertinib combined with AZD5438 (a cyclin-dependent kinase 2 inhibitor) synergistically prevented NIHL in zebrafish. Our results underscore the potential for in silico transcriptome-based drug screening in diseases lacking efficient models and suggest EGFR inhibitors as potential treatments for NIHL, meriting clinical trials.
Topics: Animals; ErbB Receptors; Zebrafish; Transcriptome; Mice; Hearing Loss, Noise-Induced; Disease Models, Animal; Computer Simulation; Protein Kinase Inhibitors; Humans; Drug Evaluation, Preclinical; Mice, Knockout; Gene Expression Profiling
PubMed: 38896614
DOI: 10.1126/sciadv.adk2299 -
Molecules (Basel, Switzerland) Jun 2024Spinal muscular atrophy (SMA) is a severe neuromuscular disorder that is caused by mutations in the survival motor neuron 1 () gene, hindering the production of... (Review)
Review
Spinal muscular atrophy (SMA) is a severe neuromuscular disorder that is caused by mutations in the survival motor neuron 1 () gene, hindering the production of functional survival motor neuron (SMN) proteins. Antisense oligonucleotides (ASOs), a versatile DNA-like drug, are adept at binding to target RNA to prevent translation or promote alternative splicing. Nusinersen is an FDA-approved ASO for the treatment of SMA. It effectively promotes alternative splicing in pre-mRNA transcribed from the gene, an analog of the gene, to produce a greater amount of full-length SMN protein, to compensate for the loss of functional protein translated from . Despite its efficacy in ameliorating SMA symptoms, the cellular uptake of these ASOs is suboptimal, and their inability to penetrate the CNS necessitates invasive lumbar punctures. Cell-penetrating peptides (CPPs), which can be conjugated to ASOs, represent a promising approach to improve the efficiency of these treatments for SMA and have the potential to transverse the blood-brain barrier to circumvent the need for intrusive intrathecal injections and their associated adverse effects. This review provides a comprehensive analysis of ASO therapies, their application for the treatment of SMA, and the encouraging potential of CPPs as delivery systems to improve ASO uptake and overall efficiency.
Topics: Cell-Penetrating Peptides; Humans; Muscular Atrophy, Spinal; Oligonucleotides, Antisense; Animals; Oligonucleotides; Survival of Motor Neuron 2 Protein; Survival of Motor Neuron 1 Protein; Blood-Brain Barrier
PubMed: 38893532
DOI: 10.3390/molecules29112658 -
Molecules (Basel, Switzerland) May 2024A set of 2-aryl-9-H or methyl-6-morpholinopurine derivatives were synthesized and assayed through radioligand binding tests at human A, A, A, and A adenosine receptor...
A set of 2-aryl-9-H or methyl-6-morpholinopurine derivatives were synthesized and assayed through radioligand binding tests at human A, A, A, and A adenosine receptor subtypes. Eleven purines showed potent antagonism at A, A, dual A/A, A/A, or A/A adenosine receptors. Additionally, three compounds showed high affinity without selectivity for any specific adenosine receptor. The structure-activity relationships were made for this group of new compounds. The 9-methylpurine derivatives were generally less potent but more selective, and the 9H-purine derivatives were more potent but less selective. These compounds can be an important source of new biochemical tools and/or pharmacological drugs.
Topics: Humans; Structure-Activity Relationship; Purinergic P1 Receptor Antagonists; Receptors, Purinergic P1; Molecular Structure; Adenine; Morpholines; Purines; CHO Cells
PubMed: 38893418
DOI: 10.3390/molecules29112543 -
International Journal of Molecular... May 2024Sigma non-opioid intracellular receptor 1 (Sigma-1R) is an intracellular chaperone protein residing on the endoplasmic reticulum at the mitochondrial-associated membrane...
Sigma non-opioid intracellular receptor 1 (Sigma-1R) is an intracellular chaperone protein residing on the endoplasmic reticulum at the mitochondrial-associated membrane (MAM) region. Sigma-1R is abundant in the brain and is involved in several physiological processes as well as in various disease states. The role of Sigma-1R at the blood-brain barrier (BBB) is incompletely characterized. In this study, the effect of Sigma-1R activation was investigated in vitro on rat brain microvascular endothelial cells (RBMVEC), an important component of the blood-brain barrier (BBB), and in vivo on BBB permeability in rats. The Sigma-1R agonist PRE-084 produced a dose-dependent increase in mitochondrial calcium, and mitochondrial and cytosolic reactive oxygen species (ROS) in RBMVEC. PRE-084 decreased the electrical resistance of the RBMVEC monolayer, measured with the electric cell-substrate impedance sensing (ECIS) method, indicating barrier disruption. These effects were reduced by pretreatment with Sigma-1R antagonists, BD 1047 and NE 100. In vivo assessment of BBB permeability in rats indicates that PRE-084 produced a dose-dependent increase in brain extravasation of Evans Blue and sodium fluorescein brain; the effect was reduced by the Sigma-1R antagonists. Immunocytochemistry studies indicate that PRE-084 produced a disruption of tight and adherens junctions and actin cytoskeleton. The brain microcirculation was directly visualized in vivo in the prefrontal cortex of awake rats with a miniature integrated fluorescence microscope (aka, miniscope; Doric Lenses Inc.). Miniscope studies indicate that PRE-084 increased sodium fluorescein extravasation in vivo. Taken together, these results indicate that Sigma-1R activation promoted oxidative stress and increased BBB permeability.
Topics: Animals; Receptors, sigma; Blood-Brain Barrier; Sigma-1 Receptor; Rats; Reactive Oxygen Species; Endothelial Cells; Male; Mitochondria; Calcium; Morpholines; Brain; Cells, Cultured
PubMed: 38791182
DOI: 10.3390/ijms25105147 -
Biosensors Apr 2024Zebrafish larvae have emerged as a valuable model for studying heart physiology and pathophysiology, as well as for drug discovery, in part thanks to its transparency,...
Zebrafish larvae have emerged as a valuable model for studying heart physiology and pathophysiology, as well as for drug discovery, in part thanks to its transparency, which simplifies microscopy. However, in fluorescence-based optical mapping, the beating of the heart results in motion artifacts. Two approaches have been employed to eliminate heart motion during calcium or voltage mapping in zebrafish larvae: the knockdown of cardiac troponin T2A and the use of myosin inhibitors. However, these methods disrupt the mechano-electric and mechano-mechanic coupling mechanisms. We have used ratiometric genetically encoded biosensors to image calcium in the beating heart of intact zebrafish larvae because ratiometric quantification corrects for motion artifacts. In this study, we found that halting heart motion by genetic means (injection of morpholino) or chemical tools (incubation with -aminoblebbistatin) leads to bradycardia, and increases calcium levels and the size of the calcium transients, likely by abolishing a feedback mechanism that connects contraction with calcium regulation. These outcomes were not influenced by the calcium-binding domain of the gene-encoded biosensors employed, as biosensors with a modified troponin C (Twitch-4), calmodulin (mCyRFP1-GCaMP6f), or the photoprotein aequorin (GFP-aequorin) all yielded similar results. Cardiac contraction appears to be an important regulator of systolic and diastolic Ca levels, and of the heart rate.
Topics: Animals; Zebrafish; Calcium; Biosensing Techniques; Myocardial Contraction; Larva; Heart; Troponin T; Zebrafish Proteins; Troponin C
PubMed: 38785693
DOI: 10.3390/bios14050219 -
Nature Communications May 2024Hypomyelinating leukodystrophy (HLD) is an autosomal recessive disorder characterized by defective central nervous system myelination. Exome sequencing of two siblings...
Hypomyelinating leukodystrophy (HLD) is an autosomal recessive disorder characterized by defective central nervous system myelination. Exome sequencing of two siblings with severe cognitive and motor impairment and progressive hypomyelination characteristic of HLD revealed homozygosity for a missense single-nucleotide variant (SNV) in EPRS1 (c.4444 C > A; p.Pro1482Thr), encoding glutamyl-prolyl-tRNA synthetase, consistent with HLD15. Patient lymphoblastoid cell lines express markedly reduced EPRS1 protein due to dual defects in nuclear export and cytoplasmic translation of variant EPRS1 mRNA. Variant mRNA exhibits reduced METTL3 methyltransferase-mediated writing of N-methyladenosine (mA) and reduced reading by YTHDC1 and YTHDF1/3 required for efficient mRNA nuclear export and translation, respectively. In contrast to current models, the variant does not alter the sequence of mA target sites, but instead reduces their accessibility for modification. The defect was rescued by antisense morpholinos predicted to expose mA sites on target EPRS1 mRNA, or by mA modification of the mRNA by METTL3-dCas13b, a targeted RNA methylation editor. Our bioinformatic analysis predicts widespread occurrence of SNVs associated with human health and disease that similarly alter accessibility of distal mRNA mA sites. These results reveal a new RNA-dependent etiologic mechanism by which SNVs can influence gene expression and disease, consequently generating opportunities for personalized, RNA-based therapeutics targeting these disorders.
Topics: Female; Humans; Male; Adenosine; Hereditary Central Nervous System Demyelinating Diseases; Homozygote; Methyltransferases; Mutation, Missense; Nerve Tissue Proteins; RNA Splicing Factors; RNA, Messenger; RNA-Binding Proteins
PubMed: 38769304
DOI: 10.1038/s41467-024-48549-x -
Frontiers in Cell and Developmental... 2024Prohibitin (PHB) is an essential scaffold protein that modulates signaling pathways controlling cell survival, metabolism, inflammation, and bone formation. However,...
Prohibitin (PHB) is an essential scaffold protein that modulates signaling pathways controlling cell survival, metabolism, inflammation, and bone formation. However, its specific role in periodontium development remains less understood. This study aims to elucidate the expression pattern and function of PHB in periodontium development and its involvement in alveolar bone formation. Immunolocalization of PHB in the periodontium of postnatal (PN) mice were examined. morpholino was micro-injected into the right-side mandible at PN5, corresponding to the position where the alveolar bone process forms in relation to the lower first molar. The micro-injection with a scramble control (PF-127) and the left-side mandibles were used as control groups. Five days post-micro-injection, immunohistochemical analysis and micro-CT evaluation were conducted to assess bone mass and morphological changes. Additionally, expression patterns of signaling molecules were examined following downregulation using 24-h cultivation of developing dental mesenchyme at E14.5. The immunostaining of PHB showed its localization in the periodontium at PN5, PN8, and PN10. The cultivation of dental mesenchyme resulted in alterations in Bmps, Runx2, and Wnt signalings after knock-down. At 5 days post-micro-injection, knocking down showed weak immunolocalizations of runt-related transcription factor (RUNX2) and osteocalcin (OCN). However, knocking down led to histological alterations characterized by decreased bone mass and stronger localizations of Ki67 and PERIOSTIN in the periodontium compared 1 to control groups. The micro-CT evaluation showed decreased bone volume and increased PDL space in the knock-down specimens, suggesting its regulatory role in bone formation. The region-specific localization of PHB in the margin where alveolar bone forms suggests its involvement in alveolar bone formation and the differentiation of the periodontal ligament. Overall, our findings suggest that plays a modulatory role in alveolar bone formation by harmoniously regulating bone-forming-related signaling molecules during periodontium development.
PubMed: 38756696
DOI: 10.3389/fcell.2024.1369634 -
Biomedicine & Pharmacotherapy =... Jun 2024Antisense oligonucleotide (ASO) has emerged as a promising therapeutic approach for treating central nervous system (CNS) disorders by modulating gene expression with...
Antisense oligonucleotide (ASO) has emerged as a promising therapeutic approach for treating central nervous system (CNS) disorders by modulating gene expression with high selectivity and specificity. However, the poor permeability of ASO across the blood-brain barrier (BBB) diminishes its therapeutic success. Here, we designed and synthesized a series of BBB-penetrating peptides (BPP) derived from either the receptor-binding domain of apolipoprotein E (ApoE) or a transferrin receptor-binding peptide (THR). The BPPs were conjugated to phosphorodiamidate morpholino oligomers (PMO) that are chemically analogous to the 2'-O-(2-methoxyethyl) (MOE)-modified ASO approved by the FDA for treating spinal muscular atrophy (SMA). The BPP-PMO conjugates significantly increased the level of full-length SMN2 in the patient-derived SMA fibroblasts in a concentration-dependent manner with minimal to no toxicity. Furthermore, the systemic administration of the most potent BPP-PMO conjugates significantly increased the expression of full-length SMN2 in the brain and spinal cord of SMN2 transgenic adult mice. Notably, BPP8-PMO conjugate showed a 1.25-fold increase in the expression of full-length functional SMN2 in the brain. Fluorescence imaging studies confirmed that 78% of the fluorescently (Cy7)-labelled BPP8-PMO reached brain parenchyma, with 11% uptake in neuronal cells. Additionally, the BPP-PMO conjugates containing retro-inverso (RI) D-BPPs were found to possess extended half-lives compared to their L-counterparts, indicating increased stability against protease degradation while preserving the bioactivity. This delivery platform based on BPP enhances the CNS bioavailability of PMO targeting the SMN2 gene, paving the way for the development of systemically administered neurotherapeutics for CNS disorders.
Topics: Animals; Blood-Brain Barrier; Oligonucleotides, Antisense; Humans; Apolipoproteins E; Mice, Transgenic; Mice; Morpholinos; Survival of Motor Neuron 2 Protein; Muscular Atrophy, Spinal; Drug Delivery Systems; Fibroblasts; Brain; Peptides; Cell-Penetrating Peptides
PubMed: 38749176
DOI: 10.1016/j.biopha.2024.116737 -
BioRxiv : the Preprint Server For... May 2024Propranolol reduces experimental murine cerebral cavernous malformations (CCMs) and prevents embryonic caudal venous plexus (CVP) lesions in zebrafish that follow mosaic...
Propranolol reduces experimental murine cerebral cavernous malformations (CCMs) and prevents embryonic caudal venous plexus (CVP) lesions in zebrafish that follow mosaic inactivation of . Because morpholino silencing of the β1 adrenergic receptor () prevents the embryonic CVP lesion, we proposed that plays a role in CCM pathogenesis. Here we report that zebrafish exhibited 86% fewer CVP lesions and 87% reduction of CCM lesion volume relative to wild type brood mates at 2dpf and 8-10 weeks stage, respectively. Treatment with metoprolol, a β1 selective antagonist, yielded a similar reduction in CCM lesion volume. zebrafish embryos exhibited reduced heart rate and contractility and reduced CVP blood flow. Similarly, slowing the heart and eliminating the blood flow in CVP by administration of 2,3-BDM suppressed the CVP lesion. In sum, our findings provide genetic and pharmacological evidence that the therapeutic effect of propranolol on CCM is achieved through β1 receptor antagonism.
PubMed: 38746306
DOI: 10.1101/2024.05.05.592554