bioRxiv Science⌕ Search

Biology subjects

Feng, W.

Publications and source records attributed to Feng, W..

At least 37 records · Page 2Linked to original sources

Coiled-coil-mediated phase separation of Spef1 for non-centrosomal microtubule organization and function

Central-pair microtubules (CP-MTs) are non-centrosomal MTs essential for planar beat pattern of cilia. The CP-MT formation requires the MT-associated protein Spef1, but the underlying molecular mechanism remains unclear. Here, we show that Spef1 undergoes liquid-liquid phase separation (LLPS) to facilitate non-centrosomal MT assembly by enriching tubulins. The LLPS of Spef1 is mediated by its C-terminal coiled-coil (CC) domain. Crystallography reveals that the Spef1-CC domain forms a parallel CC dimer with a unique charge distribution pattern on the surface. The dimerization capacity and charge distribution of Spef1-CC are both critical for controlling in-vitro LLPS. Disruption of the dimerization capacity abolishes ciliary functions of Spef1. In contrast, a charge-changing mutant with attenuated LLPS still supports the CP-MT formation but results in cilia with abnormal beat pattern. Thus, the CC-mediated LLPS of Spef1 provides a mechanistic explanation for its prominent role in controlling non-centrosomal CP-MT organization and function in the axoneme. Significance statementThe MT-associated protein Spef1 is a new essential player for the non-centrosomal CP-MT formation in motile cilia and flagella. This study reveals the unexpected LLPS feature of Spef1, leading to forming biomolecular condensates that enrich tubulins to facilitate non-centrosomal MT assembly. Spef1-CC contains a unique charge-distribution pattern, together with its dimerization capacity, contributing to multivalent interactions for initiating LLPS. The LLPS property of Spef1 is important for CP-MT formation and Spef1-mediated ciliary function. The formation of Spef1-LLPS condensates indicates that they work as MT nucleation centers and tubulin sources for the continuous growth of CP-MTs or repairing CP-MTs damaged during ciliary beating, and suggests that LLPS may be a common process for generating and organizing non-centrosomal CP-MTs in the axoneme.

cell biology↗

Hierarchical Coordination of Polymerase Theta and RAD51 Resolves Clustered Replication Fork Collapse

The essential role of polymerase theta (Pol{theta})-mediated end joining (TMEJ), an alternative double strand break repair pathway, has been primarily studied in homologous recombination (HR)-deficient contexts(1, 2). Here, we uncover an indispensable role for TMEJ in HR-proficient mammalian cells during the repair of interstrand crosslinks (ICLs). We show that Pol{theta} is recruited downstream of canonical ICL repair steps--including ICL unhooking, RAD51 loading, and RAD51 ubiquitylation--and localizes to sites of unresolved HR through interactions with ubiquitylated RAD51 filaments. Using genomic scar profiling and targeted ICL repair assays, we find that TMEJ resolves a minor subset of lesions that are not amenable to HR repair, such as clustered ICLs that can induce two-ended replication fork collapse. These findings reveal a RAD51 ubiquitylation-dependent mechanism for Pol{theta} recruitment and establish TMEJ as a hierarchically deployed DNA repair pathway that safeguards genome stability when HR is insufficient to resolve replication-associated DNA damage. Short SummaryPol{theta} is recruited via RAD51 ubiquitylation to resolve clustered ICLs that generate HR-refractory replication fork collapse.

cell biology↗

miR-486-3p ameliorates aging-related impaired angiogenesis in adult moyamoya disease by targeting Forkhead Box O4

ObjectiveInvestigate miR-486-3ps role in alleviating age-related angiogenic decline in Moyamoya disease (MMD) by regulating senescent endothelial cells. MethodsClinical analysis of 151 MMD patients correlated age with postoperative angiogenesis (DSA grading). Senescent HUVECs (SA-{beta}-gal>80%) exhibited elevated SASP factors (IL-6/IL-8/MCP-1). Functional assays (EdU/Transwell/Matrigel) and bioinformatics identified miR-486-3p targets, validated via luciferase/Western blot. ResultsPatients [&ge;]35 years had 3.67-fold higher risk of poor angiogenesis (OR=3.67). Senescent HUVECs showed 10-16-fold higher SASP secretion (p<0.01). miR-486-3p overexpression increased proliferation (EdU+25%), migration (1.7-fold), and tube formation (+40% branches) in senescent cells (p<0.01) and enhanced angiogenesis in vivo (p<0.001). miR-486-3p directly targeted FOXO4, reducing its luciferase activity (-35%) and protein levels (-37%) (p<0.01), suppressing SASP. ConclusionmiR-486-3p enhances post-revascularization angiogenesis in MMD by inhibiting FOXO4-mediated SASP, offering a therapeutic target and predictive biomarker.

molecular biology↗

Deciphering the Sequence Basis and Application of Transcriptional Initiation Regulation in Plant Genomes Through Deep Learning

Transcription initiation is a critical regulatory step in plant gene expression, yet its sequence determinants remain largely elusive. Here we introduce GenoRetriever, an interpretable deep learning model that deciphers the sequence basis of transcriptional initiation regulation across plant genomes. Trained on STRIPE-seq data from 16 soybean tissues and six other crop species, GenoRetriever identifies 27 core sequence motifs that govern transcription start site (TSS) selection and usage. The model predicts TSS locations and usage levels with high accuracy, as validated by in silico motif insertions, saturation mutagenesis, and CRISPR-Cas9 promoter editing. It further reveals that 31.85% of natural variation between wild and domesticated soybean drives shifts in promoter motif usage during domestication, and uncovers lineage-specific motif effects between monocots and dicots. This interpretable model and its user-friendly web server for promoter analysis and design make GenoRetriever both a methodological innovation and practical tool for plant functional genomics and crop improvement.

plant biology↗

Histone 3 lysine 36 trimethylation by SETD2 shapes an epigenetic landscape in intestinal stem cells to orchestrate lipid metabolism and prevent cell senescence.

The self-renewal capacity of intestinal stem cells (ISCs) declines with aging, leading to a loss of homeostasis and an increased susceptibility to intestinal diseases. Despite the established significance of lipid metabolism and epigenetic regulation in ISC function, the molecular mechanisms that connect these processes to aging-related ISC dysfunction remain elusive. Here, we demonstrate that Histone 3 lysine 36 trimethylation (H3K36me3) caused by SETD2 is critical for ISC stemness. We found that H3K36me3 deficiency results in reduced ISC proliferation and differentiation, disrupts fatty acid oxidation (FAO) metabolism, and induces ISC senescence. Mechanistically, the loss of H3K36me3 triggers the activity of the SWI/SNF chromatin remodeling complex and leads to increased chromatin accessibility and enhancer activation, which alters FAO- and senescence-related gene expression. Importantly, we discover that metabolic intervention can prevent the senescence of ISC due to H3K36me3 deficiency. Our findings reveal a crucial role for H3K36me3 in maintaining the epigenetic landscape that orchestrates FAO metabolism and determines intestinal stem cell functions, emphasizing the role of FAO as a key modulator between H3K36me3 and ISC aging, suggesting that metabolic intervention may help mitigate age-related ISC dysfunction.

cell biology↗

Non-invasive skin topical delivery of hyaluronan

Hyaluronic acid (HA), a key glycosaminoglycan in the skin extracellular matrix, diminishes with aging, leading to dryness, wrinkles, and loss of elasticity. While subcutaneous HA injection remains the standard treatment, it is invasive and associated with complications. Here, we developed a zwitterionic polymer-based nanogel system (HA/OP) for noninvasive transdermal HA delivery. The nanogels, formed by complexing HA with poly[2-(N-oxide-N,N-diethylamino)ethyl methacrylate] (OP), exhibited pH-responsive behavior, remaining stable at weakly acidic skin surface pH ([~]5) but dissociating in neutral dermal environments. HA/OP nanogels efficiently permeated the stratum corneum via sebum-assisted enrichment and para-corneocyte transport, followed by transcytosis and enhanced paracellular penetration mediated by myosin light-chain kinase (MLCK) upregulation. This enabled deep HA deposition in the dermis and subcutaneous tissue, significantly improving skin hydration and reducing wrinkles in hairless mice without irritation. Our findings present a safe, needle-free strategy for topical HA delivery, addressing a major unmet need in cosmetic and dermatological applications.

bioengineering↗

Systematic Identification of Microtubule Inner Proteins Reveals JPT2 as a Key Regulator of Lumen Microenvironment and Drug Sensitivity

Microtubules are primarily studied for the interactions of proteins that bind to their outer surfaces and ends, while the regulatory mechanisms within the microtubule lumen, particularly in singlet microtubules critical for essential cellular processes, remain largely unexplored. Our study provides the first systematic identification of key regulatory proteins within the single microtubule lumen. Using proximity-dependent biotin identification (Bio-ID) coupled with mass spectrometry, we identified candidate microtubule inner proteins (MIPs), including Jupiter microtubule-associated homolog 2 (JPT2). JPT2 binds directly to microtubules and specifically localizes within the lumen, where it modulates the luminal environment by inhibiting acetylase MEC17 and independently affects the binding and efficacy of Paclitaxel. Furthermore, our screening identified additional MIPs that influence cellular sensitivity to Paclitaxel, indicating a link between luminal regulation and drug responsiveness. These discoveries reveal JPT2s critical role in singlet microtubule regulation and suggest new therapeutic targets for enhancing cancer drug sensitivity.

cell biology↗

Cited4a limits cardiomyocyte dedifferentiation and proliferation during zebrafish heart regeneration

Cardiac regeneration involves the interplay of complex interactions between many different cell types, including cardiomyocytes. The exact mechanism that enables cardiomyocytes to undergo dedifferentiation and proliferation to replace lost cells has been intensely studied. Here we report a single nuclear RNA sequencing profile of the injured zebrafish heart and identify distinct cardiomyocyte populations in the injured heart. These cardiomyocyte populations have diverse functions, including stress response, myofibril assembly, proliferation and contraction. The contracting cardiomyocyte population also involves the activation of maturation pathways as an early response to injury. This intriguing finding suggests that constant maintenance of a distinctive terminally differentiated cardiomyocyte population is important for cardiac function during regeneration. To test this hypothesis, we determined that cited4a, a p300/CBP transcriptional coactivator, is induced after injury in the mature cardiomyocyte population. Moreover, loss-of-cited4a mutants presented increased dedifferentiation, proliferation and accelerated heart regeneration. Thus, suppressing cardiomyocyte maturation pathway activity in injured hearts could be an approach to promote heart regeneration.

developmental biology↗

Lack of Ameliorative Effect of Chronic Oral Nicotine on Olfactory Dysfunction in Young Adult Presenilin-1/2 Double Knockout Mice of a Dementia Model

Olfactory dysfunction is a prevalent and early feature of neurodegenerative diseases including Alzheimers disease while the features and underlying mechanisms remain inadequately understood. This investigation aimed to elucidate the olfactory function characteristics of presenilin-1/2 double knockout (DKO) mice, an established mouse model of dementia. Through a series of behavioral tests on DKO and wildtype (WT) mice at 2 and 6 months of age, we assessed their abilities in odor detection, discrimination, and olfactory memory. The findings revealed a substantial deficit in odor detection in 2-month-old DKO mice compared to WT mice, with a noteworthy age-related deterioration observed from 2 to 6 months. Although DKO mice exhibited normal odor discrimination and olfactory memory capabilities at 2 months, these functions declined with age, falling significantly lower levels than observed in WT mice by the age of 6 months. Subsequently, 2-month-old DKO and WT mice underwent a 4-month chronic nicotine treatment through drinking water. This intervention failed to ameliorate olfactory dysfunctions in DKO mice and exhibited no significant impact on WT mice, despite a discernible trend of a potential negative effect. In summary, this behavioral study elucidates that Presenilin-1/2 double knockout impairs odor detection in young adult mice and accelerates declines of olfactory discrimination and memory. The chronic administration of nicotine did not effectively mitigate olfactory function deficiencies in young adult DKO mice, and the results also highlight age as an important contributing factor.

animal behavior and cognition↗

Assessing Conformation Validity and Rationality of Deep Learning-Generated 3D Molecules

Recent advancements in artificial intelligence (AI) have revolutionized the field of 3D molecule generation. However, the lack of effective evaluation methods for 3D conformations limits further improvements. Current techniques, in order to achieve the necessary speed for evaluating large numbers of AI-generated molecules, often rely on empirical geometric metrics that do not adequately capture various conformational anomalies, or on molecular mechanics (MM) energy metrics that exhibit low accuracy and lack atomic or torsional details. To address this gap, we propose a two-stage approach that achieves both high speed and quantum mechanical (QM) level accuracy. The first stage, termed the validity test, employs an AI-derived force field to identify atoms with elevated energy resulting from implausible neighboring environments. The second stage, known as the rationality test, utilizes a deep learning network trained on data with density functional theory (DFT) accuracy to detect rotatable bonds with high torsional energies. To demonstrate the functionality of our evaluation system, we applied our approach to five recently reported 3D molecule generation AI models across 102 targets in Directory of Useful Decoys-Enhanced (DUD-E) dataset. To facilitate accessibility for the academic community, our method is available as an open-source package.

bioinformatics↗

Irx3/5 define the cochlear sensory domain and regulate vestibular and cochlear sensory patterning in the mammalian inner ear

The mammalian inner ear houses the vestibular and cochlear sensory organs dedicated to sensing balance and sound, respectively. These distinct sensory organs arise from a common prosensory region, but the mechanisms underlying their divergence remain elusive. Here, we showed that two evolutionarily conserved homeobox genes, Irx3 and Irx5, are required for the patterning and segregation of the saccular and cochlear sensory domains, as well as for the formation of auditory sensory cells. Irx3/5 were highly expressed in the cochlea, their deletion resulted in a significantly shortened cochlea with a loss of the ductus reuniens that bridged the vestibule and cochlea. Remarkably, ectopic vestibular hair cells replaced the cochlear non-sensory structure, the Greater Epithelial Ridge. Moreover, most auditory sensory cells in the cochlea were transformed into hair cells of vestibular identity, with only a residual organ of Corti remaining in the mid-apical region of Irx3/5 double knockout mice. Conditional temporal knockouts further revealed that Irx3/5 are essential for controlling cochlear sensory domain formation before embryonic day 14. Our findings demonstrate that Irx3/5 regulate the patterning of vestibular and cochlear sensory cells, providing insights into the separation of vestibular and cochlear sensory organs during mammalian inner ear development.

developmental biology↗

NSD2 promotes cell durotaxis and drives the transition from PKD to tubulocystic renal cell carcinoma through integrin/FAK/AKT signaling

Renal cell carcinoma (RCC) is one of the most common malignancies in the urinary system. NSD2 is an H3K36-specific di-methyltransferase which has been reported to participate in diverse biological processes and human tumors. However, its role in RCC remains unclear. Here, we found that NSD2 is highly expressed in RCC, which is associated with poor survival in RCC patients. NSD2 facilitates the transition from Myc-induced polycystic kidney disease to tubulocystic renal cell carcinoma (TCRCC), which is a rare RCC subtype with distinctive clinicopathologic and genetic characterizations. The mice with kidney-specific overexpression of MYC and NSD2 (KMN) display severe cyst burden at only 6 weeks of age, and develop into TCRCC at 12 weeks of age. Mechanistically, NSD2 transcriptionally upregulates the expressions of integrins (Itga4 and Itga11), to further activate the FAK/AKT pathway. In addition, we found that NSD2 enhances the cell proliferation on the stiff matrix of PEGDA hydrogel. Moreover, inhibition of FAK signaling relieves the symptoms of KMN mice, and significantly rescues the enhanced cell proliferation caused by NSD2 overexpression in vitro. Together, our findings highlight an epigenetic mechanism by which NSD2 regulates TCRCC tumorigenesis through the integrin/FAK/AKT pathway. This study may also pave the way for the development of targeted, patient-tailored therapies for TCRCC patients with NSD2 amplification or high expression.

cancer biology↗

PointTree: Automatic and accurate reconstruction of long-range axonal projections of single-neuron

Single-neuron axonal projections reveal the route map of neuron output and provide a key cue for understanding how information flows across the brain. Reconstruction of single-neuron axonal projections requires intensive manual operations in tens of terabytes of brain imaging data, and is highly time-consuming and labor-intensive. The main issue lies in the need for precise reconstruction algorithms to avoid reconstruction errors, yet current methods struggle with densely distributed axons, focusing mainly on skeleton extraction. To overcome this, we introduce a point assignment-based method that uses cylindrical point sets to accurately represent axons and a minimal information flow tree model to suppress the snowball effect of reconstruction errors. Our method successfully reconstructs single-neuron axonal projections across hundreds of GBs (Gigabytes) images with an average of 80% F1-score, while current methods only provide less than 40% F1-score reconstructions from a few hundred MBs (Megabytes) images. This huge improvement is helpful for high-throughput mapping of neuron projections.

neuroscience↗

Distinct duration and diet dependent lipid profiles and renal complicationsin GCK-MODY

Heterozygous inactivating mutations in the glucokinase (GCK) gene cause one of the most common types of maturity-onset diabetes of the young type 2 (MODY2), also named GCK-MODY. Studies suggest that, unlike other types of diabetes, patients with GCK-MODY do not have increased risk of diabetic complications and therefore do not typically require antihyperglycemic therapy. However, long-term outcomes of GCK-MODY on lipid profiles and chronic complications under different dietary scenarios remain unclear. Herein, using a knock-in mouse model expressing a novel MODY causing mutation GCK-Q26L (GCKMut), we examined age- and diet-related lipid profiles and diabetic complications. We found that, although GCKMut mice exhibited mild elevated blood glucose, the lipid profiles, body fat composition, and diabetic kidney disease (DKD) were initially improved in high-fat-diet (HFD) fed mice at the age of 28 weeks, supporting potential beneficial effects of GCKMut on lipid metabolism and kidney health. Unexpectedly however, those protective effects diminished by 40 weeks, and became more severe dyslipidemia and kidney injury associated with renal fibrosis and inflammation at 60-week-old mice fed with normal diet (ND) or HFD. Those findings revealed distinct duration- and diet-dependent effects of inactivating GCK mutation on lipid profiles and DKD, highlighting previously unrealized long-term chronic complications in GCK-MODY.

physiology↗

Development of a DNA-encoded library screening method DEL Zipper to empower the study of RNA-targeted chemical matter

To date, RNA-targeted chemical matter is under explored due to a lack of robust screening assays. In this study, we present a novel RNA-targeted small molecule screening approach using a specialized DNA-encoded library (DEL). Our findings reveal that the specialized DEL library, called "DEL Zipper", can significantly reduce single-stranded DNA-RNA region interaction signals during various kinds of RNA selection. By performing the selection against both G-quadruplex, we have identified novel hits that interact with RNA targets and the results are validated through binding. This study demonstrates that the "DEL Zipper" method is a robust screening assay that has potential for discovering small molecule ligands for diverse RNA targets.

molecular biology↗

Inducible biosynthesis of bacterial cellulose in recombinant Enterobacter sp. FY-07

Bacterial cellulose (BC) is an extracellular polysaccharide with myriad unique properties, such as high purity, water-holding capacity and biocompatibility, making it attractive in materials science. However, genetic engineering techniques for BC-producing microorganisms are rare. Herein, the electroporation-based gene transformation and the {lambda} Red-mediated gene knockout method with a nearly 100% recombination efficiency were established in the fast-growing and BC hyperproducer Enterobacter sp. FY-07. This genetic manipulation toolkit was validated by inactivating the protein subunit BcsA in the cellulose synthase complex. Subsequently, the inducible BC-producing strains from glycerol were constructed through inducible expression of the key gene fbp in the gluconeogenesis pathway, which recovered more than 80% of the BC production. Finally, the BC properties analysis results indicated that the induced-synthesized BC pellicles were looser, more porous and reduced crystallinity, which could further broaden the application prospects of BC. To our best knowledge, this is the first attempt to construct the completely inducible BC-producing strains. Our work paves the way for increasing BC productivity by metabolic engineering and broadens the available fabrication methods for BC-based advanced functional materials.

synthetic biology↗

CAMSAP3 Forms Dimers via its lapha-helix Domain that Directly Stabilize Non-centrosomal Microtubule Minus Ends

Microtubules are vital components of the cytoskeleton. Their plus ends are dynamic and respond to changes in cell morphology, while the minus ends are stable and serve a crucial role in microtubule seeding and maintaining spatial organization. In mammalian cells, the calmodulin-regulated spectrin-associated proteins (CAMSAPs), play a key role in directly regulating the dynamics of non-centrosomal microtubules minus ends. However, the molecular mechanisms are not yet fully understood. Our study reveals that CAMSAP3 forms dimers through its C-terminal -helix; this dimerization not only enhances the microtubule-binding affinity of the CKK domain but also enables the CKK domain to regulate the dynamics of microtubules. Furthermore, CAMSAP3 also specializes in decorating at the minus end of microtubules through the combined action of the microtubule-binding domain (MBD) and the C-terminal -helix, thereby achieving dynamic regulation of the minus ends of microtubules. These findings are crucial for advancing our understanding and treatment of diseases associated with non-centrosomal microtubules. SignificanceOur study reveals the molecular mechanism of how CAMSAP3, a key regulator of non-centrosomal microtubule dynamics, directly regulates the dynamics of non-centrosomal microtubule minus ends through CKK domain. CAMSAP3 forms dimers through its C-terminal -helix, which enhances the CKK domain of CAMSAP3 binding to microtubule minus ends and confers stability of them. This finding is not limited to CAMSAP3, but can also be applied to the understanding of the regulation of non-centrosomal microtubule minus end stability by CAMSAP family proteins. Our findings deepen our comprehension of cellular structure and function, offering insights into the role of microtubules in cellular integrity and disease. This study fills a significant knowledge gap and lays the foundation for future research into the complex balance of microtubule dynamics required for cellular health and disease prevention.

cell biology↗

The Iroquois (Iro/Irx) homeobox genes are conserved Hox targets involved in motor neuron development

The Iroquois (Iro/Irx) homeobox genes encode transcription factors with fundamental roles in animal development. Despite their link to various congenital conditions in humans, our understanding of Iro/Irx gene expression, function, and regulation remains incomplete. Here, we conducted a systematic expression analysis of all six mouse Irx genes in the embryonic spinal cord. We found five Irx genes (Irx1, Irx2, Irx3, Irx5, and Irx6) to be confined mostly to ventral spinal domains, offering new molecular markers for specific groups of post-mitotic motor neurons (MNs). Further, we engineered Irx2, Irx5, and Irx6 mouse mutants and uncovered essential but distinct roles for Irx2 and Irx6 in MN development. Last, we found that the highly conserved regulators of MN development across species, the HOX proteins, directly control Irx gene expression both in mouse and C. elegans MNs, critically expanding the repertoire of HOX target genes in the developing nervous system. Altogether, our study provides important insights into Iro/Irx expression and function in the developing spinal cord, and uncovers an ancient gene regulatory relationship between HOX and Iro/Irx genes.

developmental biology↗