Biology subjects

Qin, D.

Publications and source records attributed to Qin, D..

At least 19 recordsLinked to original sources

bioRxiv2026

The Par complex regulates apical-basal cell polarity through modulation of FAK signaling homeostasis

Cell polarity complexes are essential for embryogenesis, but their regulatory mechanisms during early developmental transitions remain incompletely understood. Here, we individually deleted the Crumbs, Par, and Scrib polarity complexes in mouse embryonic stem cells (mESCs). While loss of any single complex did not affect pluripotency or proliferation, deletion of Par complex disrupted the naive-to-primed transition and impaired subsequent differentiation, particularly lumen formation in neural tube organoids. Mechanistically, Par complex deficiency led to hyperphosphorylation of focal adhesion kinase (FAK) at the primed stage, driving a morphological shift from flat monolayer clusters to dome-shaped colonies. FAK inhibition rescued the aberrant morphology. Upstream, Par complex loss increased AKT phosphorylation, which remodeled extracellular matrix (ECM) and regulated integrin signaling via FURIN-LEFTY, ultimately modulating FAK activity. In addition, conditioned medium from wild-type cells partially rescued differentiation defects in Par knockout cells in a LEFTY-dependent manner. These phenotypes were consistently observed in naive-to-primed transition, neural stem cell differentiation, embryoid body formation, teratoma assays, and neural tube organoid differentiation. Together, these findings establish a Par complex-AKT-FURIN-LEFTY-ECM-integrin-FAK signaling cascade that links apical-basal polarity to early lineage specification and morphogenesis, providing a mechanistic framework for how polarity cues are translated into developmental outcomes. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/722465v1_ufig1.gif" ALT="Figure 1"> View larger version (64K): org.highwire.dtl.DTLVardef@179e0adorg.highwire.dtl.DTLVardef@8d83bdorg.highwire.dtl.DTLVardef@c425fforg.highwire.dtl.DTLVardef@19a8ee5_HPS_FORMAT_FIGEXP M_FIG C_FIG Significance StatementThis study elucidates the molecular mechanism by which the Par complex regulates the establishment of cell polarity. The authors demonstrate that the Par complex promotes the expression of the protein convertase FURIN via AKT signaling, thereby enhancing the maturation and secretion of LEFTY protein. This process remodels the ECM and modulates integrin signaling, ultimately regulating FAK activity and controlling the establishment of cell polarity. These findings reveal how polarity cues govern early lineage specification and morphogenesis, with implications across multiple developmental contexts.

developmental biology↗

bioRxiv2026

A Single-Cell Temporal Atlas of Mouse Nasal Embryonic Development

The mammals breathe and perceive odors through anatomically and functionally distinct respiratory and olfactory regions of the nose; however, how the early embryo endows this system remains largely unknown. Here, we present a temporal high-resolution single-cell RNA sequencing (scRNA-seq) atlas of mouse nasal development, comprising 183,247 cells collected from 20 embryos spanning embryonic day 10.5 (E10.5) to E18.5. We identified 7 major cell clusters and 52 molecularly defined subtypes, including previously unrecognized rare populations and niche-derived signaling components involved in progenitor cell maintenance. Lineage reconstruction of epithelial and mesenchymal compartments revealed dynamic cell fate transitions and highlighted candidate regulators of lineage specification, including Foxa1 as a regulator of nasal respiratory ciliated epithelium differentiation. Integration with adult nasal epithelium datasets further delineated transcriptional dynamics of olfactory stem cells. This study provides a molecular roadmap of nasal development and offers a valuable resource for future research into nasal biology and regenerative strategies.

developmental biology↗

bioRxiv2026

Chromatin context-dependent deacetylation by the asymmetric Rpd3L

The regulation of gene expression requires precise control of chromatin-associated complexes that respond to diverse structural and epigenetic cues. The Rpd3 Large (Rpd3L) complex is a Sin3 histone deacetylase (HDAC) complex that dynamically adapt to chromatin states to reinforce transcriptional silencing, yet the mechanisms governing the catalytic activation in chromatin context-dependent manner remain unclear. Here we present the cryo-EM structure of Rpd3L bound to both mono- and di-nucleosome substrate at near-atomic resolution, uncovering a substrate-guided allosteric activation mechanism. Rpd3L adopts an asymmetric architecture, in which the proximal catalytic module anchors the first nucleosome, while the Sin3 PAH domains engage linker DNA to reposition a second nucleosome. This spatial configuration brings the distal catalytic module into proximity with chromatin and unlocks its latent deacetylase activity. Biochemical and mass spectrometry analyses confirm that dual nucleosome engagement selectively enhances Rpd3L activity and broadens substrate specificity. Together, these findings establish a hierarchical mechanism by which Rpd3L interprets histone modifications and nucleosome organization to modulate its enzymatic output at promoter regions. Our study provides a framework for understanding higher-order chromatin repression mechanisms by chromatin-regulation complexes and co-repressors.

molecular biology↗

bioRxiv2025

Structural basis for BCL7B-mediated ncBAF-nucleosome engagement

The mammalian SWI/SNF family of chromatin remodelers comprises BRG1/BRM-associated factor (cBAF), Polybromo-associated BAF (PBAF), and non-canonical BAF (ncBAF) complexes, which slide and disassemble nucleosomes to regulate gene expression and chromatin structure dependent on ATP hydrolysis energy. While the chromatin engagement mechanisms of cBAF and PBAF have been structurally resolved, the molecular architecture governing ncBAF interaction with chromatin remains elusive. In this study, by integrating cryo-electron microscopy, biochemical assays and cross-linking mass spectrometry, we resolved the conformational transition of ncBAF-nucleosome complexes from nucleotide-free to nucleotide-bound states. Our analyses establish BCL7 proteins as dynamic molecular tethers connecting the ARP module to the nucleosomal acidic patch and demonstrate that BCL7B promotes ncBAF-mediated nucleosome remodeling, with BRG1-catalyzed ATP hydrolysis triggering conformational changes that modulate BCL7-mediated histone association. Structurally and biochemically, we further demonstrate that {beta}-actin within the BCL7-containing ARP module retains ATP hydrolysis activity, rendering its exposed pointed end structurally compatible with incorporation into the barbed end of nuclear actin filaments, which provides a potential molecular basis for coordinating nuclear actin networks with chromatin remodeling. Collectively, our findings unravel a dynamic role of BCL7 in regulating ncBAF-mediated chromatin remodeling and establish a distinct chromatin engagement mode of ncBAF from that of cBAF/PBAF.

molecular biology↗

bioRxiv2025

When Animals Turn Inside Out: The Eversion of Bloodworms

Bloodworms, Glycera dibranchiata, possess an eversible proboscis that normally remains concealed within their bodies but explosively everts if the worm attacks or burrows. How does the bloodworm evert quickly and reliably? In a series of experiments, we characterize bloodworm kinematics, pressure, and material properties to estimate the criteria for eversion safely without rupture of the proboscis. We predict the proboscis can withstand pressures 50 times higher and bending strains up to three times higher than the respective values observed. We also present a dimensional analysis of eversion, finding that everting animals, from frogs to snails to sharks, do not satisfy Froudes law for equivalence of velocities. Our findings may help inspire the development of pressure-driven soft robots with efficient retraction capabilities.

biophysics↗

bioRxiv2025

Unravelling drug resistant proteotypes through phenotype-resolved proteomics of single-cell derived colonies

Drug resistance remains a major cause of treatment failure and disease progression and is closely linked to intratumoral heterogeneity. Mass spectrometry (MS)-based single-cell proteomics (SCP) can resolve drug-resistant cell states, but current methods lack clonal and phenotype information and are often confounded by cell-cycle and cell-size effects. Here, we introduce PhenoSCoP, a microscopy-guided discovery proteomics framework that profiles single-cell-derived colonies to map proteomic heterogeneity while preserving clonal origin and image-defined phenotypes. In head and neck squamous cell carcinoma models, PhenoSCoP distinguished heritable clone-intrinsic cisplatin (CP) response programs from adaptive treatment-induced changes, uncovered pre-existing resistant-like proteotypes in treatment-naive populations, and identified an NDUFB11-associated mitochondrial vulnerability in a resistant clone. In patient-derived primary HNSCC cells, CP-tolerant cells resolved into two proteomic states with distinct phenotypes and high or low S100A7/A8/A9 expression. These programs were also detected in HNSCC patient tissues and, in an illustrative matched progression case, increased across metastatic sites. PhenoSCoP therefore provides a phenotype-resolved framework for discovering stable and adaptive proteotypes associated with therapeutic response.

systems biology↗

bioRxiv2025

Male germline vulnerability to DNA damage causes sex-biased mutation

In many vertebrates the male germline mutation rate is higher than that of females, so-called male mutation bias, the causes of which are central to numerous molecular evolution debates including the relationship between life history traits and the mutation rate and the cause of the generation time effect. The male bias was classically considered a consequence of the higher number of cell divisions in the male germline, but recently multiple lines of evidence find this to be an inadequate explanation. The revived damage-induced hypothesis posits that males are either more prone to germline damage or less likely to repair damage, leading to more mutations. The model predicts that, when males and females are treated with approximately equal levels of mutagenic stress, the male germline will accumulate more mutations. Here we provide the first test of the damage hypothesis by exposing male and female mice to mutagenic chemicals with both untreated and a non-mutagenic (PBS) controls, assaying de novo mutations via parent-offspring whole-genome sequencing. As predicted, in the instances where the mutagens caused a net increase to the mutation rate, it went up more in male germline. Comparison with established mutational signatures reveals differential involvement of the base excision repair (BER) pathway. Similarly, transcriptome analysis finds higher expression levels of DNA repair genes in ovary compared to testis for those genes in the BER pathway, a difference that becomes more extreme on administration of mutagens. As parental age, hence number of germline cell divisions, is controlled, we conclude that the male mutation bias is, at least in part, owing to differential damage repair with lower base excision repair in males playing a significant role.

evolutionary biology↗

bioRxiv2025

Comparative Temporal Transcriptomic Analysis of SOD1 Mutations in iPSC-Motor Neurons

Mutations in the SOD1 gene are among the most significant genetic contributors to amyotrophic lateral sclerosis (ALS), with different variants linked to varying disease severity. To investigate the molecular mechanisms driving this variability, we conducted RNA sequencing on spinal motor neurons (MNs) differentiated from isogenic human induced pluripotent stem cell (iPSC) lines engineered via CRISPR/Cas9. These lines carried two representative SOD1 heterogenous mutations, D91A and G94A, and were analyzed at Days 10 and 20 of neuronal maturation stage to capture the temporal changes of gene expression. We aim to explore how these mutations affect MN function, identify distinct molecular pathways that may explain the variable severity of ALS, and investigate the role of translation and metabolic dysregulation in disease progression.

bioinformatics↗

bioRxiv2025

Unveiling the pathogenicity of Cunninghamella echinulata SMH-1 and its bioactive metabolites through metabolomics: Dual-action disruption of Solenopsis invicta mitochondrial bioenergetics and cuticular integrity

The invasive red imported fire ant, Solenopsis invicta, poses significant ecological and economic challenges, necessitating sustainable alternatives to conventional pest control. This study evaluates the biocontrol potential of Cunninghamella echinulata isolate SMH-1, an entomopathogenic fungus, through integrated morphological, biochemical, and metabolomic analyses. Light and scanning electron microscopy elucidated infection dynamics, revealing conidial germination, cuticular penetration, and systemic hyphal proliferation, culminating in complete cadaver colonization. At 1x10 conidia/mL, SMH-1 achieved 100% mortality in S. invicta workers within 7 days, with virulence maintained across thermal gradients (10-30{degrees}C). Acetone extracts of SMH- 1 induced dose-dependent lethality, reaching 100% mortality at 1,000 mg/L. Nineteen significantly differentiated metabolites were identified from phospholipids category through UPLC/MS analysis of isolate SMH-1. The derived compounds also showed strong potential against S. invicta, among which dihydrocoumarin caused 100% mortality over 12-days of exposure. The bioactivity of isolate SMH-1 (Conidia), (extracts) and (dihydrocoumarin) against S. invicta revealed significantly differentiated metabolites as (Sulfolithocholylglycine, PE(18_1(9Z)_0_0), CE(12:0), LysoPI(18:1(9Z)/0:0) and Hydroxydestruxin B), (Tropine, lignoceric acid, 9-deoxy-9-methylene-16,16-dimethyl-PGE2, Flecainide and Jubanine B), and (3-O-alpha-D-Glucopyranuronosyl-D-xylose, Rilmakalim, 2-Amino-3-methyl-1-butanol, 2,4-Dimethyl-1,3-oxazole-5-carboxylic acid and Caffeinol), respectively. Citrate cycle (TCA) was significantly impacted by differential expression of pyruvate, pyruvic acid, succinic acid and fumaric acid. These findings underscore SMH-1s multifaceted biocontrol potential, combining direct pathogenicity, thermo-tolerance, and metabolite-mediated toxicity. By delineating host-pathogen interactions and metabolic disruptions, this work advances C. echinulata isolate SMH-1 as a sustainable candidate for integrated S. invicta management, offering an eco-friendly alternative to synthetic insecticides. Author SummaryInvasive fire ants (S. invicta) threaten ecosystems and agriculture worldwide, and current chemical controls often harm the environment. In this study, we explored a natural alternative: a soil-dwelling fungus called Cunninghamella echinulata (strain SMH-1). We discovered that this fungus can kill fire ants with remarkable efficiency. When applied directly, its spores caused 100% ant mortality within a week, even under varying temperatures. We also identified key fungal compounds, including dihydrocoumarin, which are lethal to ants. By studying how the fungus invades and disrupts the ants biology-such as breaking down their protective outer layers and interfering with their energy production, we revealed why SMH-1 is so effective. Our findings highlight SMH-1s potential as a safe, eco-friendly biocontrol agent. This fungus could reduce reliance on synthetic pesticides, offering farmers and communities a sustainable tool to combat fire ant invasions while protecting biodiversity. Our work bridges lab discoveries and real-world pest management, paving the way for greener solutions in agriculture and ecosystem conservation.

microbiology↗

bioRxiv2025

Multimodal brain cell atlas across the adult macaque lifespan

High-throughput single-cell omics of non-human primate tissues present a remarkable opportunity to study primate brain aging. Here, we introduce a transcriptomic and chromatin accessibility landscape of 1,985,317 cells from eight brain regions of 13 cynomolgus female monkeys spanning adult lifespan including exceptionally old individuals up to 29-years old. This dataset uncovers dynamic molecular changes in critical brain functions such as synaptic communication and axon myelination, exhibiting a high degree of cell type and brain region specificity. We identify the multicellular networks of the pons and medulla as a previously unrecognized hotspot for aging. Furthermore, comparative analyses with human neurodegeneration datasets highlight both shared and distinct mechanisms contributing to aging and disease. In addition, we uncover transcription factors implicated in monkey brain aging and pinpoint aging-regulated loci linked to longevity and neurodegeneration. This spatiotemporal atlas will advance our understanding of primate brain aging and its broader implications for health and disease.

neuroscience↗

bioRxiv2025

Neoadjuvant anti-4-1BB confers protection against spontaneous metastasis through low-affinity intratumor CD8+ T cells in triple-negative breast cancer

Neoadjuvant immunotherapy seeks to harness the primary tumor as a source of relevant tumor antigens to enhance systemic anti-tumor immunity through improved immunological surveillance. Despite having revolutionized the treatment of patients with high-risk early-stage triple-negative breast cancer (TNBC), a significant portion of patients remain unresponsive and succumb to metastatic recurrence post-treatment. Here, we found that optimally scheduled neoadjuvant administration of anti-4-1BB monotherapy was able to counteract metastases and prolong survival following surgical resection. Phenotypic and transcriptional profiling revealed enhanced 4-1BB expression on tumor-infiltrating intermediate (Tint), relative to progenitor (Tprog) and terminally exhausted (Tterm) T cells. Furthermore, Tint was enriched in low-affinity T cells. Treatment with anti-4-1BB drove clonal expansion of Tint, with reduced expression of tissue-retention marker CD103 in Tprog. This was accompanied by increased TCR clonotype sharing between paired tumors and pre-metastatic lungs. Further interrogation of sorted intratumor T cells confirmed enhanced T cell egress into circulation following anti-4-1BB treatment. In addition, gene signature extracted from anti-4-1BB treated Tint was consistently associated with improved clinical outcomes in BRCA patients. Combinatorial neoadjuvant anti-4-1BB and ablation of tumor-derived CXCL16 resulted in enhanced therapeutic effect. These findings illustrate the intratumor changes underpinning the efficacy of neoadjuvant anti-4-1BB, highlighting the reciprocity between local tissue-retention and distant immunologic fortification, suggesting treatment can reverse the siphoning of intratumor T cells to primary tumor, enabling redistribution to distant tissues and subsequent protection against metastases.

immunology↗

bioRxiv2024

Evaluating the Radiation Sensitivity Index and 12-chemokine gene expression signature for clinical use in a CLIA laboratory

BackgroundThe radiation sensitivity index (RSI) and 12-chemokine gene expression signature (12CK GES) are two gene expression signatures (GES) that were previously developed to predict tumor radiation sensitivity or identify the presence of tertiary lymphoid structures in tumors, respectively. To advance the use of these GES into clinical trial evaluation, their assays must be assessed within the context of the Clinical Laboratory Improvement Amendments (CLIA) process. MethodsUsing HG-U133Plus 2.0 arrays, we first established CLIA laboratory proficiency. Then the accuracy (limit of detection and macrodissection impact), precision (variability by time and operator), sample type (surgery vs. biopsy), and concordance with reference laboratory were evaluated. ResultsRSI and 12CK GES were reproducible (RSI: 0.01 mean difference, 12CK GES 0.17 mean difference) and precise with respect to time and operator. Taken together, the reproducibility analysis of the scores indicated a median RSI difference of 0.06 (6.47% of range) across samples and a median 12CK GES difference of 0.92 (12.29% of range). Experiments indicated that the lower limit of input RNA is 5 ng. Reproducibility with a second CLIA laboratory demonstrated reliability with the median RSI score difference of 0.065 (6% of full range) and 12CK GES difference of 0.93 (12 % of observed range). ConclusionsOverall, under CLIA, RSI and 12CK GES were demonstrated by the Moffitt Cancer Center Advanced Diagnostic Laboratory to be reproducible GES for clinical usage.

genomics↗

bioRxiv2024

Cerebrospinal Fluid Dynamics: Uncovering Alternative Blood Vessel Clearance Mechanisms

The pathways that run along the olfactory nerves crossing the cribriform plate and connecting to lymphatic vessels in the nasal cavity, have been identified as a crucial route for cerebrospinal fluid (CSF) outflow. However, the presence of a CSF efflux pathway through blood vessels in this region has yet to be clarified. This study aimed to elucidate the anatomical connections between the subarachnoid space and the bloodstream at the nasal epithelium and the venous drainage routes of the nasal epithelium in mice. Our findings demonstrated that CSF tracers could be drained not only through lymphatic vessels in the nasal cavity and cervical lymph nodes (CLNs), but also through the blood vessels in this area that extend to its venous drainage routes, including the facial and jugular veins. Additionally, we showed that ligation of CLNs neither impeded the influx and efflux of CSF tracers nor exacerbated Alzheimers disease (AD)-related pathology in AD mice. Our work reveals a previously unrecognized pathway for CSF drainage through blood vessels within the nasal mucosa. These findings provide insight into the efficient removal of waste products, facilitating optimal functioning of neural tissue within the susceptible tissue of our brains.

neuroscience↗

bioRxiv2023

Activating SRC/MAPK signaling via 5-HT1A receptor contributes to the effect of vilazodone on improving thrombocytopenia

Thrombocytopenia caused by long-term radiotherapy and chemotherapy exists in cancer treatment. Previous research demonstrates that 5-Hydroxtrayptamine (5-HT) and its receptors induces the formation of megakaryocytes (MKs) and platelets. However, the relationships between 5-HT1A receptor (5-HTR1A) and MKs is unclear so far. We screened and investigated the mechanism of vilazodone as a 5-HTR1A partial agonist in promoting MK differentiation and evaluated its therapeutic effect in thrombocytopenia. We employed a drug screening model based on machine learning (ML) to screen the megakaryocytopoiesis activity of VLZ. The effects of Vilazodone (VLZ) on megakaryocytopoiesis were verified in HEL and Meg-01 cells. Tg (itga2b: eGFP) zebrafish was performed to analyze the alterations in thrombopoiesis. Moreover, we established a thrombocytopenia mice model to investigate VLZ administration accelerates platelet recovery and function. We carried out network pharmacology, Western blot and immunofluorescence to demonstrate the potential targets and pathway of VLZ. VLZ has been predicted to have a potential biological action. Meanwhile, VLZ administration promotes MK differentiation and thrombopoiesis in cells and zebrafish models. Progressive experiments showed that VLZ has a potential therapeutic effect on radiation-induced thrombocytopenia in vivo. The network pharmacology and associated mechanism study indicated that SRC and MAPK signaling are both involved in the processes of megakaryopoiesis facilitated by VLZ. Furthermore, the expression of 5-HTR1A during megakaryocyte differentiation is closely related to the activation of SRC and MAPK. Our findings demonstrated that the expression of 5-HTR1A on MK, VLZ could bind to the 5-HTR1A receptor and further regulate the SRC/MAPK signaling pathway to facilitate megakaryocyte differentiation and platelet production, which provides new insights into the alternative therapeutic options for thrombocytopenia.

pharmacology and toxicology↗

bioRxiv2023

An automated and fast sample preparation workflow for laser microdissection guided ultrasensitive proteomics

Spatial tissue proteomics integrating whole-slide imaging, laser microdissection and ultrasensitive mass spectrometry is a powerful approach to link cellular phenotypes to functional proteome states in (patho)physiology. To be applicable to large patient cohorts and low sample input amounts, including single-cell applications, loss-minimized and streamlined end-to-end workflows are key. We here introduce an automated sample preparation protocol for laser microdissected samples utilizing the cellenONE(R) robotic system, which has the capacity to process 192 samples in three hours. Following laser microdissection collection directly into the proteoCHIP LF 48 or EVO 96 chip, our optimized protocol facilitates lysis, formalin de-crosslinking and tryptic digest of low-input archival tissue samples. The seamless integration with the Evosep ONE LC system by centrifugation allows on-the-fly sample clean-up, particularly pertinent for laser microdissection workflows. We validate our method in human tonsil archival tissue, where we profile proteomes of spatially-defined B-cell, T-cell and epithelial microregions of 4,000 {micro}m2 to a depth of [~]2,000 proteins and with high cell type specificity. We finally provide detailed equipment templates and experimental guidelines for broad accessibility.

systems biology↗

bioRxiv2023

AKAP8 interacting with DDX5 to regulate R-loop balance involves in lung carcinoma cell growth

Triple-nucleotide chain of RNA:DNA hybrid structure R-loop is formed during transcription process which is closely associated with transcriptional regulation, transcriptional termination, epigenetic modifications, and structure of chromatin. Dysregulation of R-loop formation or resolution may disturb normal DNA replication or RNA transcription, leading to associated progress of disease. Herein, we found A-kinase-anchoring protein 8 (AKAP8) bind with R-loop structure in cell. Knock down of AKAP8 showed perturbation of balance of genomic R-loop formation and gene transcription. Evidences was shown that AKAP8 interacted with R-loop resolution protein ATP-dependent DEAD box RNA helicase DDX5 and increased chromatin associated DDX5 level. Finally, AKAP8 promoted UCP2 transcription and resolved R-loop level of its promoter region, and contributed to cell growth of adenocarcinomic human alveolar basal epithelial cell line A549, which may provide clues for poor prognosis of lung adenocarcinoma in high AKAP8 expression patients.

cell biology↗

bioRxiv2023

Transcriptome-wide analysis of the function of Ded1 in translation preinitiation complex assembly in a reconstituted in vitro system

We have developed a deep sequencing-based approach, Rec-Seq, that allows simultaneous monitoring of ribosomal 48S pre-initiation complex (PIC) formation on every mRNA in the translatome in an in vitro reconstituted system. Rec-Seq isolates key early steps in translation initiation in the absence of all other cellular components and processes. Using this approach we show that the DEAD-box ATPase Ded1 promotes 48S PIC formation on the start codons of >1000 native mRNAs, most of which have long, structured 5-untranslated regions (5UTRs). Remarkably, initiation measured in Rec-Seq was enhanced by Ded1 for most mRNAs previously shown to be highly Ded1-dependent by ribosome profiling of ded1 mutants in vivo, demonstrating that the core translation functions of the factor are recapitulated in the purified system. Our data do not support a model in which Ded1acts by reducing initiation at alternative start codons in 5UTRs and instead indicate it functions by directly promoting mRNA recruitment to the 43S PIC and scanning to locate the main start codon. We also provide evidence that eIF4A, another essential DEAD-box initiation factor, is required for efficient PIC assembly on almost all mRNAs, regardless of their structural complexity, in contrast to the preferential stimulation by Ded1 of initiation on mRNAs with long, structured 5UTRs.

biochemistry↗

bioRxiv2023

In vivo Ontogeny of human forebrain neural progenitor cell grafts in adult rats: an immunohistological study

A thorough understanding of the cell behaviors of the human neural grafts is fundamental to exploit them to achieve cell therapy for recovering brain functions. Here by using immunohistological staining, we trace the cell fate of the intrastriatal human neural progenitor cell (NPC) grafts up to 9 months in adult rats, with multiple examining time points to provide a unified working time frame for future transplantation study. Lots of Nestin+/Sox2+ human cells continuously migrate along the white matter tracts into distal brain parenchyma even long time after transplantation, providing a potential for curing diffuse brain damage. Further analysis reveals a significant heterogeneity of the long-term sustained neural stem cells (NSC)/NPCs that progressing throughout different stages, mimicking the neural development of human forebrain. More importantly, the initial GFAP expression in human grafts marks the NSC progression instead of terminal astrocyte differentiation. The distally migrating human cells continuously show the capability to produce new neurons, albeit at a low efficiency in the intact brain. Further investigations in neural disease models are needed. Such study would benefit neural cell therapy with regarding to the optimization of the transplantation strategy and choosing of acting mode by neural grafts (e.g. via cell replacement or ex vivo gene therapy).

cell biology↗