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Voskoboynik, Y.

Publications and source records attributed to Voskoboynik, Y..

6 recordsLinked to original sources

Lifelong Invertebrate Chordate Central Nervous System Regeneration is Driven by a Migrating Pool of Conserved Neural Stem Cells Program

Adult central nervous systems (CNS) are generally constrained by limited cellular replacement. How regenerating organisms integrate structural maintenance with continuous, cyclic renewal remains unresolved. Here, we leverage the colonial chordate Botryllus schlosseri which completely resorbs and regenerates its entire CNS de novo weekly. Combining indexed single-cell sorting, Smart-seq3 sequencing, spatial mapping, and temporal deconvolution, our studies suggest that this continuous CNS renewal is mediated by an intrinsic pool of lineage-restricted neural stem cells. Single-cell analysis resolved a conserved SOX2/NOTCH1/NEUROG1 prospective progenitor continuum alongside mature excitability-defined neurons. Brain aging drives a phase-specific desynchronization of this regenerative program, inducing early hyper-activation followed by a sudden collapse. Finally, syngeneic transplantation and in vivo tracking show that neural-complex-derived cells persist after vascular delivery and localize to developing bud and neural-associated territories, with injury-associated accumulation near the neural gland. This work establishes a spatiotemporal framework for lifelong chordate CNS renewal and aging.

cell biology↗

Germline stem cell isolation, lineage tracing, and aging in a protochordate

Germline stem cells (GSCs), the source of gametes, are the only stem cells capable of passing genes to future generations and are therefore considered units of natural selection. Yet, the factors that influence GSC fitness, and thus govern GSC competition, which exist in both protochordates and mammals, remain poorly understood. We studied how aging affects GSC fitness in the protochordate Botryllus schlosseri, an evolutionary crosspoint between invertebrates and vertebrates. GSCs were isolated and distinguished from developing and mature gametes using flow cytometry and scRNA-Seq, facilitated by a new PacBio genome assembly. Moreover, their function was validated through a novel lineage tracing approach that combines membrane-labeled GSC transplantation with scRNA-Seq. Leveraging our method to isolate them, single-cell transcriptomics showed significant age-related changes between young and old GSCs. Spermatids and sperm, however, showed minimal changes, suggesting that reproductive aging is governed by GSCs rather than by gametes. Reduced expressions of markers like DDX4 and PIWIL1 in aged GSCs mirrored trends in mammalian datasets, pointing to a conserved GSC-driven aging mechanism across chordate evolution. This study provides new techniques that lay the foundation to investigate further drivers of GSC fitness and highlights fertility-related genes as promising targets for therapies to preserve reproductive health.

cell biology↗

Electrical Stimulation Rejuvenates Tunicates: Altered Stem Cell and Immune Activity

Applicable methods of rejuvenating organisms and improving resistance to environmental stimuli are needed. During attempts to synchronize heart rates in unhealthy colonial chordates, we observed morphological rejuvenation. While the importance of endogenously generated bioelectric currents in development is well-established1,2, and exogenously applied current has shown promise in regenerative medicine3,4,5,6,7,8,9, a model that robustly increases longevity and fertility while providing detailed mechanistic insights has not been reported. Here, we report the establishment of such a model using pulsatile electrical current (PEC) in Botryllus schlosseri, an established colonial chordate model10,11,12,13,14,15. PEC treatment significantly improved survival, morphological integrity, stem cell mediated regeneration, and gonad production in Botryllus. Transcriptomic analysis revealed pathway changes associated with cellular metabolism, cell cycle, stem cell activity, DNA repair, and immune modulation. Notably, PEC-induced expression patterns resemble the exercise-induced macrophage-associated transcriptional response previously observed across several mammalian species16,17. This transcriptomic signature correlated with an increase in immune-cell-containing populations. These findings demonstrate that PEC can improve longevity, vitality, and reproduction in an established model renowned for defining broadly applicable biological principles. These studies offer insights into novel strategies for promoting healthy aging and organismal survival.

developmental biology↗

Polypyrimidine Tract-Binding Protein 1 (PTBP1) regulates CD4 T cell Activation independent of its role in proliferation

Our previous work found that the RNA binding protein polypyrimidine tract-binding protein (PTBP1) is critical for regulating multiple events in T cell activation including changes in proliferation, and expression of activation markers and cytokines. These changes corresponded to the regulation of the ERK1/2 and NF-{kappa}B pathways as well as through changes in steady-state RNA levels. Because proliferation is critical for driving T cell activation, it was unclear whether PTBP1 was required for optimal activation per se or whether changes were secondary to a requirement for initiating/sustaining proliferation. To address this question, the human T cell lymphoma cell line, Jurkat, which recapitulates many of the molecular events of TCR-induced activation, was used to understand how PTBP1 impacts early events in T cell activation with ongoing proliferation. Using two phenotypically distinct Jurkat subclones (D1.1 and B2.7), we first profiled global RNA expression patterns using RNAseq analysis and found marked differences between the two cell lines with the D1.1 line giving a more antigen-experienced phenotype. Reducing PTBP1 by shPTB expression, to 60% WT levels resulted in no significant decrease in proliferation in the two subclones. However, we observed that PTBP1 was required for both optimal expression of activation markers, CD25, CD38, CD69, and CD40L, and signaling through the ERK1/2, P38 and AKT pathways. Importantly, limiting PTBP1 had different effects on the activation signals for each cell line suggesting that the differentiation state of the cell is a critical factor in understanding the role of PTBP1 in T cell activation. This was further reinforced by our finding that PTBP1 regulated distinct groups of genes specific for each line. Together, our findings suggest that PTBP1 regulates specific T cell activation responses independent of its role in proliferation and that the initial phenotype of the T cell plays an essential role in the dependency of the cell on PTBP1 for driving these changes.

immunology↗

Stemness activity underlying whole brain regeneration in a basal chordate

Central nervous system (CNS) regeneration extent is highly diverse across the metazoans, with adult mammals demonstrating limited ability1,2. Understanding how neurons regenerate following injury remains a central challenge in regenerative medicine. Although conserved pathways associated with neural regeneration have been identified3,4, a study describing the stepwise morphogenetic changes that take place throughout a complete CNS regeneration is lacking. Utilizing the highly regenerative tunicate model Polycarpa mytiligera5, we characterized the morphological, cell proliferation, and transcriptomic dynamics that lead to entire CNS regeneration. The regenerated CNS of adult P. mytiligera expressed key neurodevelopmental markers that are not otherwise present in the adult CNS. Removal of the entire CNS resulted in high cell proliferation in the regenerated area. Transcriptome analysis revealed enhanced stem-cell related gene activity, with high expression of P53 and piRNA pathways preceding the activation of Notch, Wnt, and Nanos pathways. The CNS regeneration atlas created here depicts the transcriptomic landscape of the entire CNS regeneration process, revealing the core pathways that regulate neuronal response to injury, and the regeneration stage at which they are most pronounced. The molecular and cellular mechanisms controlling regenerative capacity that this atlas reveals could be used to develop approaches to enhancing neurogenesis in closely-related chordate species, including humans.

developmental biology↗

Global Age-Specific Patterns of Cyclic Gene Expression Revealed by Tunicate Transcriptome Atlas

Expression levels of circadian clock genes, which regulate 24-hour rhythms of behavior and physiology, have been shown to change with age. However, a study holistically linking aging and circadian gene expression is missing. Using the colonial chordate Botryllus schlosseri, we combined transcriptome sequencing and stem cell-mediated aging phenomena to test how circadian gene expression changes with age. This revealed that B. schlosseri clock and clock-controlled genes oscillate organism-wide, with daily, age-specific amplitudes and frequencies. These age-related, circadian patterns persist at the tissue level, where dramatic variations in cyclic gene expression of tissue profiles link to morphological and cellular aging phenotypes. Similar cyclical expression differences were found in hundreds of pathways associated with known hallmarks of aging, as well as pathways that were not previously linked to aging. The atlas we developed points to alterations in circadian gene expression as a key regulator of aging. One Sentence SummaryThe Ticking Clock: Systemic changes in circadian gene expression correlates with wide-ranging phenotypes of aging

developmental biology↗