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Experimental Eye Research Jul 2024Müller glia and microglia are capable of phagocytosing fragments of retinal cells in response to retinal injury or degeneration. However, the direct evidence for their...
Müller glia and microglia are capable of phagocytosing fragments of retinal cells in response to retinal injury or degeneration. However, the direct evidence for their mutual interactions between Müller glia and microglia in the progression of retinal degeneration (RD) remains largely unclear. This study aims to construct a progressive RD mouse model and investigate the activated pattern of Müller glia and the interplay between Müller glia and microglia in the early stage or progression of RD. A Prohibitin 2 (Phb2) photoreceptor-specific knockout (RKO) mouse model was generated by crossing Phb2 mice with Rhodopsin-Cre mice. Optical Coherence Tomography (OCT), histological staining, and Electroretinography (ERG) assessed retinal structure and function, and RKO mice exhibited progressive RD from six weeks of age. In detail, six-week-old RKO mice showed no significant retinal impairment, but severe vision dysfunction and retina thinning were shown in ten-week-old RKO mice. Furthermore, RKO mice were sensitive to Light Damage (LD) and showed severe RD at an early age after light exposure. Bulk retina RNA-seq analysis from six-week-old control (Ctrl) and RKO mice showed reactive retinal glia in RKO mice. The activated pattern of Müller glia and the interplay between Müller glia and microglia was visualized by immunohistology and 3D reconstruction. In six-week-old RKO mice or light-exposed Ctrl mice, Müller glia were initially activated at the edge of the retina. Moreover, in ten-week-old RKO mice or light-exposed six-week-old RKO mice with severe photoreceptor degeneration, abundant Müller glia were activated across the whole retinas. With the progression of RD, phagocytosis of microglia debris by activated Müller glia were remarkably increased. Altogether, our study establishes a Phb2 photoreceptor-specific knockout mouse model, which is a novel mouse model of RD and can well demonstrate the phenotype of progressive RD. We also report that Müller glia in the peripheral retina is more sensitive to the early damage of photoreceptors. Our study provides more direct evidence for Müller glia engulfing microglia debris in the progression of RD due to photoreceptor Phb2 deficiency.
Topics: Animals; Retinal Degeneration; Microglia; Mice; Ependymoglial Cells; Electroretinography; Repressor Proteins; Mice, Knockout; Disease Models, Animal; Tomography, Optical Coherence; Prohibitins; Photoreceptor Cells, Vertebrate; Mice, Inbred C57BL; Phagocytosis
PubMed: 38763352
DOI: 10.1016/j.exer.2024.109935 -
Age-related and species-specific methylation changes in the protein-coding marmoset sperm epigenome.Aging Cell May 2024The sperm epigenome is thought to affect the developmental programming of the resulting embryo, influencing health and disease in later life. Age-related methylation...
The sperm epigenome is thought to affect the developmental programming of the resulting embryo, influencing health and disease in later life. Age-related methylation changes in the sperm of old fathers may mediate the increased risks for reproductive and offspring medical problems. The impact of paternal age on sperm methylation has been extensively studied in humans and, to a lesser extent, in rodents and cattle. Here, we performed a comparative analysis of paternal age effects on protein-coding genes in the human and marmoset sperm methylomes. The marmoset has gained growing importance as a non-human primate model of aging and age-related diseases. Using reduced representation bisulfite sequencing, we identified age-related differentially methylated transcription start site (ageTSS) regions in 204 marmoset and 27 human genes. The direction of methylation changes was the opposite, increasing with age in marmosets and decreasing in humans. None of the identified ageTSS was differentially methylated in both species. Although the average methylation levels of all TSS regions were highly correlated between marmosets and humans, with the majority of TSS being hypomethylated in sperm, more than 300 protein-coding genes were endowed with species-specifically (hypo)methylated TSS. Several genes of the glycosphingolipid (GSL) biosynthesis pathway, which plays a role in embryonic stem cell differentiation and regulation of development, were hypomethylated (<5%) in human and fully methylated (>95%) in marmoset sperm. The expression levels and patterns of defined sets of GSL genes differed considerably between human and marmoset pre-implantation embryo stages and blastocyst tissues, respectively.
PubMed: 38757354
DOI: 10.1111/acel.14200 -
PLoS Computational Biology May 2024The eukaryotic mRNA life cycle includes transcription, nuclear mRNA export and degradation. To quantify all these processes simultaneously, we perform thiol-linked...
The eukaryotic mRNA life cycle includes transcription, nuclear mRNA export and degradation. To quantify all these processes simultaneously, we perform thiol-linked alkylation after metabolic labeling of RNA with 4-thiouridine (4sU), followed by sequencing of RNA (SLAM-seq) in the nuclear and cytosolic compartments of human cancer cells. We develop a model that reliably quantifies mRNA-specific synthesis, nuclear export, and nuclear and cytosolic degradation rates on a genome-wide scale. We find that nuclear degradation of polyadenylated mRNA is negligible and nuclear mRNA export is slow, while cytosolic mRNA degradation is comparatively fast. Consequently, an mRNA molecule generally spends most of its life in the nucleus. We also observe large differences in the nuclear export rates of different 3'UTR transcript isoforms. Furthermore, we identify genes whose expression is abruptly induced upon metabolic labeling. These transcripts are exported substantially faster than average mRNAs, suggesting the existence of alternative export pathways. Our results highlight nuclear mRNA export as a limiting factor in mRNA metabolism and gene regulation.
Topics: RNA, Messenger; Humans; Cell Nucleus; Active Transport, Cell Nucleus; RNA Stability; 3' Untranslated Regions; Cell Line, Tumor; Cytosol
PubMed: 38753883
DOI: 10.1371/journal.pcbi.1012059 -
Anais Da Academia Brasileira de Ciencias 2024In pursuit of potential agents to treat Chagas disease and leishmaniasis, we report the design, synthesis, and identification novel naphthoquinone hydrazide-based...
In pursuit of potential agents to treat Chagas disease and leishmaniasis, we report the design, synthesis, and identification novel naphthoquinone hydrazide-based molecular hybrids. The compounds were subjected to in vitro trypanocide and leishmanicidal activities. N'-(1,4-Dioxo-1,4-dihydronaphthalen-2-yl)-3,5-dimethoxybenzohydrazide (13) showed the best performance against Trypanosoma cruzi (IC50 1.83 µM) and Leishmania amazonensis (IC50 9.65 µM). 4-Bromo-N'-(1,4-dioxo-1,4-dihydronaphthalen-2-yl)benzohydrazide (16) exhibited leishmanicidal activity (IC50 12.16 µM). Regarding trypanocide activity, compound 13 was low cytotoxic to LLC-MK2 cells (SI = 95.28). Furthermore, through molecular modeling studies, the cysteine proteases cruzain, rhodesain and CPB2.8 were identified as the potential biological targets.
Topics: Naphthoquinones; Trypanosoma cruzi; Trypanocidal Agents; Drug Design; Leishmania; Hydrazines; Animals; Antiprotozoal Agents; Parasitic Sensitivity Tests; Inhibitory Concentration 50; Structure-Activity Relationship; Cysteine Endopeptidases
PubMed: 38747836
DOI: 10.1590/0001-3765202420230375 -
Open Biology May 2024The neuronal cell adhesion molecule contactin-4 () is genetically associated with autism spectrum disorder (ASD) and other psychiatric disorders. -deficient mouse models...
The neuronal cell adhesion molecule contactin-4 () is genetically associated with autism spectrum disorder (ASD) and other psychiatric disorders. -deficient mouse models have previously shown that CNTN4 plays important roles in axon guidance and synaptic plasticity in the hippocampus. However, the pathogenesis and functional role of CNTN4 in the cortex has not yet been investigated. Our study found a reduction in cortical thickness in the motor cortex of mice, but cortical cell migration and differentiation were unaffected. Significant morphological changes were observed in neurons in the M1 region of the motor cortex, indicating that CNTN4 is also involved in the morphology and spine density of neurons in the motor cortex. Furthermore, mass spectrometry analysis identified an interaction partner for CNTN4, confirming an interaction between CNTN4 and amyloid-precursor protein (APP). Knockout human cells for CNTN4 and/or APP revealed a relationship between CNTN4 and APP. This study demonstrates that CNTN4 contributes to cortical development and that binding and interplay with APP controls neural elongation. This is an important finding for understanding the physiological function of APP, a key protein for Alzheimer's disease. The binding between CNTN4 and APP, which is involved in neurodevelopment, is essential for healthy nerve outgrowth.
Topics: Animals; Mice; Amyloid beta-Protein Precursor; Humans; Mice, Knockout; Contactins; Neurons; Motor Cortex; Protein Binding; Cell Movement
PubMed: 38745463
DOI: 10.1098/rsob.240018 -
Nature Communications May 2024The role of the hippocampus in spatial navigation has been primarily studied in nocturnal mammals, such as rats, that lack many adaptations for daylight vision. Here we...
The role of the hippocampus in spatial navigation has been primarily studied in nocturnal mammals, such as rats, that lack many adaptations for daylight vision. Here we demonstrate that during 3D navigation, the common marmoset, a new world primate adapted to daylight, predominantly uses rapid head-gaze shifts for visual exploration while remaining stationary. During active locomotion marmosets stabilize the head, in contrast to rats that use low-velocity head movements to scan the environment as they locomote. Pyramidal neurons in the marmoset hippocampus CA3/CA1 regions predominantly show mixed selectivity for 3D spatial view, head direction, and place. Exclusive place selectivity is scarce. Inhibitory interneurons are predominantly mixed selective for angular head velocity and translation speed. Finally, we found theta phase resetting of local field potential oscillations triggered by head-gaze shifts. Our findings indicate that marmosets adapted to their daylight ecological niche by modifying exploration/navigation strategies and their corresponding hippocampal specializations.
Topics: Animals; Callithrix; Spatial Navigation; Hippocampus; Male; Locomotion; Vision, Ocular; Pyramidal Cells; Head Movements; Interneurons; Female; Behavior, Animal; CA1 Region, Hippocampal
PubMed: 38744848
DOI: 10.1038/s41467-024-48374-2 -
Biomedicine & Pharmacotherapy =... Jun 2024Glaucoma, the leading cause of irreversible blindness worldwide, is characterized by neurodegeneration and neuroinflammation with retinal NAD/NADP and GSH decline....
Glaucoma, the leading cause of irreversible blindness worldwide, is characterized by neurodegeneration and neuroinflammation with retinal NAD/NADP and GSH decline. Nicotinamide adenine dinucleotide (NAD)/NAD phosphate (NADP) and glutathione (GSH) are two redox reducers in neuronal and glial metabolism. However, therapeutic strategies targeting NAD/NADP or GSH do not exert ideal effects, and the underlying mechanisms are still poorly understood. We assessed morphological changes in retinal ganglion cells (RGCs), the affected neurons in glaucoma, and Müller cells, the major glial cells in the retina, as well as the levels of phosphorylated p38 (p-p38) and Caspase-3 in glaucoma patients. We constructed a modified chronic ocular hypertensive rat model and an oxygen-glucose deprivation (OGD) cell model. After applying NADPH and N-acetylcysteine (NAC), a precursor to cysteine, the rate-limiting substrate in GSH biosynthesis, to cells, apoptosis, axonal damage and peroxidation were reduced in the RGCs of the NAC group and p-p38 levels were decreased in the RGCs of the NADPH group, while in stimulated Müller cells cultured individually or cocultured with RGCs, gliosis and p38/MAPK, rather than JNK/MAPK, activation were inhibited. The results were more synergistic in the rat model, where either NADPH or NAC showed crossover effects on inhibiting peroxidation and p38/MAPK pathway activation. Moreover, the combination of NADPH and NAC ameliorated RGC electrophysiological function and prevented Müller cell gliosis to the greatest extent. These data illustrated conjoined mechanisms in glaucomatous RGC injury and Müller cell gliosis and suggested that NADPH and NAC collaborate as a neuroprotective and anti-inflammatory combination treatment for glaucoma and other underlying human neurodegenerative diseases.
Topics: Animals; NADP; p38 Mitogen-Activated Protein Kinases; Ocular Hypertension; Acetylcysteine; Rats; Male; Retinal Ganglion Cells; Rats, Sprague-Dawley; Glaucoma; Neuroinflammatory Diseases; Humans; Ependymoglial Cells; Disease Models, Animal; MAP Kinase Signaling System; Apoptosis; Chronic Disease; Neuroprotective Agents; Cells, Cultured; Lipid Peroxidation
PubMed: 38735082
DOI: 10.1016/j.biopha.2024.116711 -
Medical Image Analysis Jul 2024Prostate cancer is the second most frequent cancer in men worldwide after lung cancer. Its diagnosis is based on the identification of the Gleason score that evaluates... (Comparative Study)
Comparative Study
Prostate cancer is the second most frequent cancer in men worldwide after lung cancer. Its diagnosis is based on the identification of the Gleason score that evaluates the abnormality of cells in glands through the analysis of the different Gleason patterns within tissue samples. The recent advancements in computational pathology, a domain aiming at developing algorithms to automatically analyze digitized histopathology images, lead to a large variety and availability of datasets and algorithms for Gleason grading and scoring. However, there is no clear consensus on which methods are best suited for each problem in relation to the characteristics of data and labels. This paper provides a systematic comparison on nine datasets with state-of-the-art training approaches for deep neural networks (including fully-supervised learning, weakly-supervised learning, semi-supervised learning, Additive-MIL, Attention-Based MIL, Dual-Stream MIL, TransMIL and CLAM) applied to Gleason grading and scoring tasks. The nine datasets are collected from pathology institutes and openly accessible repositories. The results show that the best methods for Gleason grading and Gleason scoring tasks are fully supervised learning and CLAM, respectively, guiding researchers to the best practice to adopt depending on the task to solve and the labels that are available.
Topics: Neoplasm Grading; Humans; Deep Learning; Prostatic Neoplasms; Male; Algorithms; Image Interpretation, Computer-Assisted
PubMed: 38728903
DOI: 10.1016/j.media.2024.103191 -
The Journal of General Physiology Jun 2024In this Viewpoint, Holt, Fettiplace, and Müller weigh the evidence supporting a role for PIEZO and TMC channels in mechanosensory transduction in inner ear hair cells.
In this Viewpoint, Holt, Fettiplace, and Müller weigh the evidence supporting a role for PIEZO and TMC channels in mechanosensory transduction in inner ear hair cells.
Topics: Hair Cells, Auditory; Animals; Humans; Mechanotransduction, Cellular; Ion Channels
PubMed: 38727631
DOI: 10.1085/jgp.202413585 -
The Journal of Clinical Investigation May 2024Newborn mammalian cardiomyocytes quickly transition from a fetal to an adult phenotype that utilizes mitochondrial oxidative phosphorylation but loses mitotic capacity....
Newborn mammalian cardiomyocytes quickly transition from a fetal to an adult phenotype that utilizes mitochondrial oxidative phosphorylation but loses mitotic capacity. We tested whether forced reversal of adult cardiomyocytes back to a fetal glycolytic phenotype would restore proliferative capacity. We deleted Uqcrfs1 (mitochondrial Rieske iron-sulfur protein, RISP) in hearts of adult mice. As RISP protein decreased, heart mitochondrial function declined, and glucose utilization increased. Simultaneously, the hearts underwent hyperplastic remodeling during which cardiomyocyte number doubled without cellular hypertrophy. Cellular energy supply was preserved, AMPK activation was absent, and mTOR activation was evident. In ischemic hearts with RISP deletion, new cardiomyocytes migrated into the infarcted region, suggesting the potential for therapeutic cardiac regeneration. RNA sequencing revealed upregulation of genes associated with cardiac development and proliferation. Metabolomic analysis revealed a decrease in α-ketoglutarate (required for TET-mediated demethylation) and an increase in S-adenosylmethionine (required for methyltransferase activity). Analysis revealed an increase in methylated CpGs near gene transcriptional start sites. Genes that were both differentially expressed and differentially methylated were linked to upregulated cardiac developmental pathways. We conclude that decreased mitochondrial function and increased glucose utilization can restore mitotic capacity in adult cardiomyocytes, resulting in the generation of new heart cells, potentially through the modification of substrates that regulate epigenetic modification of genes required for proliferation.
Topics: Animals; Myocytes, Cardiac; Mice; Cell Proliferation; Mitochondria, Heart; Mice, Knockout; Electron Transport Complex III; Glucose
PubMed: 38722697
DOI: 10.1172/JCI165482