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Biology subjects

Hata, S.

Publications and source records attributed to Hata, S..

At least 19 recordsLinked to original sources

Gap junctions in the alimentary tract regulate reproductive span in C. elegans

Aging does not occur uniformly throughout an organism but is instead differentially regulated across distinct physiological systems. In particular, reproductive aging is often temporally distinct from somatic aging and exhibits species-specific trajectories, suggesting that different physiological functions may age independently. Here we show that mutation of inx-20, an innexin family gene encoding a gap junction component, markedly extends reproductive span, with only a minor increase in overall lifespan. Furthermore, this extension of reproductive span persists in a feminized genetic background, thereby precluding the possibility that it is driven by altered sperm dynamics. inx-20 is expressed in a specific subset of cells within the alimentary tract, and its expression is selectively repressed in a fraction of these cells during dauer diapause, suggesting a role in nutrient responses. Genetic analyses suggest that inx-20 operates via a distinct mechanism that does not intersect with the TGF-{beta} and IIS-FOXO pathways, which are established regulators of reproductive span. Collectively, our results suggest that gap junctions in the alimentary tract are a selective determinant of reproductive span, capable of extending it substantially without a commensurate effect on lifespan.

genetics↗

AKIP1 is an inner scaffold component required for centriole integrity

Centrioles are microtubule-based organelles that play crucial roles in various biological processes, including cell division, ciliogenesis and flagellar assembly. These functions require the preservation of centriole structural integrity, yet the molecular mechanisms that maintain this integrity remain incompletely understood. In this study, through large-scale gene co-dependency analysis and ultrastructure expansion microscopy (U-ExM), we identified A-kinase interacting protein 1 (AKIP1) as a novel component of the centriole inner scaffold, a luminal structural framework that supports centriole integrity. Analysis of large-scale functional genomic data from DepMap placed AKIP1 in a functional cluster with the inner scaffold components POC1A, POC1B, and POC5. Consistently, AKIP1 colocalizes with these clustered inner scaffold components in the central core region of centrioles, forming a multicomponent interaction network. We further show that AKIP1 is recruited to centrioles during G2 phase, subsequent to the recruitment of other inner scaffold components, and that its centriolar localization depends on these components. AKIP1 depletion leads to defects in centriolar microtubules and abnormal centriole morphology. Together, our findings establish AKIP1 as a downstream component of the inner scaffold that contributes to the maintenance of centriole integrity.

cell biology↗

Pathway-Centric Integration of CRISPR Fitness with Molecular Features Draws Cancer State Maps

Cancer cells display heterogeneous pathway activity that shapes therapeutic vulnerability, but mapping it remains challenging. Transcriptomic scores do not directly measure functional activity, and CRISPR knockout data alone lack molecular interpretability. We introduce StateMap, a pathway-centric framework integrating gene expression and genome-wide CRISPR knockout fitness data from the Cancer Dependency Map. For a given pathway, StateMap selects features by co-dependency and mutual information, then projects cell lines into a low-dimensional space reflecting pathway activity and molecular state. Applied to the Hippo pathway, it resolved five functional states refining the YAP-on/YAP-off dichotomy. Notably, the Hippo-strong state showed selective dependence on integrin V{beta}5; ITGAV depletion triggered Hippo-dependent cell aggregation and G1 arrest via enhanced cell-cell adhesion. Machine learning transfer to TCGA identified a matching subtype with poor prognosis, nominated NNMT as a biomarker, and predicted sensitivity to the V inhibitor Cilengitide. StateMap enables pathway-specific state mapping and discovery of state-selective therapeutic vulnerabilities.

cancer biology↗

Co-targeting an AMPK--MAPK axis reprograms CAFs and suppresses PDAC

Pancreatic ductal adenocarcinoma (PDAC) is a fatal cancer characterized by limited therapeutic options and a highly treatment-resistant tumor microenvironment. Beyond tumor-intrinsic genetic alterations, growing evidence indicates that host-microbiome interactions influence cancer progression through microbial metabolites. However, how microbiome-derived metabolites influence oncogenic signaling in PDAC remains unclear. Here, integrated profiling revealed a consistent reduction of the microbial metabolite acetic acid in fecal samples from treatment-naive patients with PDAC and in a genetically defined Drosophila model recapitulating key PDAC driver alterations. Acetic acid activates AMP-activated protein kinase, and pharmacological activation of this pathway together with inhibition of mitogen-activated protein kinase signaling suppressed tumor growth in fly and mouse models. Combined pathway targeting restored AMPK activity and suppressed cancer-associated fibroblast activation. These findings identify a microbiome-associated metabolic vulnerability in PDAC and suggest that coordinated targeting of metabolic and oncogenic signaling may restrain tumor progression and improve therapeutic strategies.

cancer biology↗

Actin Painting: a multicolor fluorescence staining method highlighting cell type-specific differences in the composition of filamentous actin architectures.

Actin is a major structural component of the cytoskeleton in eukaryotic cells, and filamentous actin (F-actin) forms a variety of types of cellular structures. Many actin probes have been developed to visualize F-actin architectures in eukaryotic cells. However, it is known that double-stained images of F-actin obtained by two different types of actin probes often show partial inconsistencies. While developing actin probes, we observed that the merged images of three distinct actin probes, each labeled with a different fluorescent dye (red, green and blue), enabled various F-actin architectures to be distinguished based on color. This differentiation arises from slight variations in the distribution of each actin probe, and results in a unique color combination of actin probes that reflects the relative intensities of the three fluorescent dyes. In this report, we introduce a new cell staining method, named Actin Painting, which exploits the unique affinity of actin-binding molecules in each actin probe to F-actin architectures. This technique allows the classification of various cell types based on their specific actin cytoskeleton.

cell biology↗

MitoNEET reduces the mitochondrial oxidative phosphorylation during epithelial-mesenchymal transition

Mitochondrial functions range from catabolic to anabolic, which are tightly coordinated to meet cellular demands for proliferation and motility. MitoNEET is a mitochondrial outer membrane protein with a CDGSH domain and is involved in mitochondrial function. Epithelial-to-mesenchymal transition (EMT) is the process in which cells lose their epithelial characteristics and acquire mesenchymal traits, such as motility, which is a vital step for organism development and wound-healing. Cellular motility is associated with high ATP consumption owing to lamellipodia formation, which is supported by upregulated oxidative phosphorylation (OXPHOS) capacity. However, how mitoNEET is involved in the regulation of OXPHOS capacity and subsequent cellular motility remains unclear. Here we show that loss of mitoNEET regulation during EMT impairs both OXPHOS enhancement and cell motility in non-transformed NMuMG mouse mammary gland epithelial cells. We found that mitoNEET is downregulated during EMT, and that the aberrant expression of mitoNEET abolishes the upregulation of OXPHOS, leading to the inhibition of cell motility. Furthermore, we found that mitoNEET topology may be crucial for the regulation of the mitochondrial electron transfer chain, suggesting an additional regulatory pathway for OXPHOS capacity. Our results demonstrate that mitochondrial OXPHOS capacity during EMT is partly regulated by the dynamics of the outer membrane protein. We believe that our findings are the first step towards understanding the mechanisms by which mitochondrial outer membrane protein topology affects organelle functions.

cell biology↗

Latent mitotic vulnerability of AML cells induced by therapeutic agents

Acute myeloid leukemia (AML) is a hematopoietic malignancy with a poor prognosis. Understanding the unidentified properties of AML cells is beneficial for the identification of novel therapeutic strategies for AML. In this study, we uncover the vulnerabilities of AML cells in mitosis when exposed to therapeutic agents. Through comparative analysis of large-scale data quantifying drug effects on cancer cell proliferation, the drug targeting the cell cycle and mitosis are predicted to possess high cytotoxicity against AML cell lines. Consistently, live-cell imaging with microwell devices demonstrates that clinical drugs targeting the cell cycle processes, such as idarubicin, pevonedistat and vincristine, potently induce mitotic cell death in AML cells. While these therapeutic agents also induce cell death through S/G2 phase arrest, the cytotoxic effects during mitosis are notably more pronounced. Furthermore, by employing additional inhibition of Chk1 to override the G2/M checkpoint, the AML cells stalled in the S/G2 phase prematurely enter mitosis, resulting in a significant increase in cell death. Collectively, these results unveiled the latent mitotic vulnerabilities of AML cells, providing a basis for developing novel therapeutic interventions.

cancer biology↗

Comprehensive analysis of end-modified long dsDNA donors in CRISPR-mediated endogenous tagging

CRISPR-mediated endogenous tagging is a powerful gene editing technique for studying protein dynamics and function in their native cellular environment. While the use of 5 modified DNA donors has emerged as a promising strategy to improve the typically low efficiency of knock-in gene editing, the underlying mechanisms remain poorly understood. In this study, we conducted a comprehensive analysis of end-modified long linear dsDNA donors in CRISPR-mediated endogenous tagging in human non-transformed cells. In-depth analysis of repair patterns reveals that 5 biotinylation of dsDNA donors significantly reduces imprecise insertions, thereby enhancing homology-directed repair (HDR)-mediated precise insertion efficiency. Notably, the impact of biotinylation on repair patterns resembles that of non-homologous end joining (NHEJ) pathway inhibition, suggesting its role in preventing NHEJ-mediated mis-integration. Moreover, combining biotin modification with NHEJ inhibitor treatment further improves bi-allelic knock-in efficiency. Overall, this study provides novel insights into the mechanisms by which 5 modifications enhance precise knock-ins and demonstrates their potential for achieving high-efficient, prercise endogenous tagging in human cells.

cell biology↗

Multimodal mechanisms of human centriole engagement and disengagement

The DNA and the centrioles are the only cellular structures that uniquely replicate to produce identical copies, which is crucial for proper chromosome segregation in mitosis. A new centriole termed "daughter" is progressively assembled adjacent to a pre-existing, "mother" centriole. Only after the daughter centriole is structurally completed as an identical copy, it disengages from its mother to become the core of a new functional centrosome. The mechanisms preventing precocious disengagement of the immature copy have been previously unknown. Here, we identify three key centriole-associated mechanisms that maintain the mother-daughter engagement: the cartwheel, the torus, and the pericentriolar material pathways. Among these, the torus is critical for establishing the characteristic orthogonal engagement between the mother and daughter centrioles. Furthermore, we show that the engagement mediated by the cartwheel and the torus pathways is released stepwise through structural changes in the daughter centriole, known as centriole blooming and centriole distancing, respectively. Disruption at any stage of these structural transitions leads to the failure of all subsequent steps, ultimately blocking centriole disengagement and centrosome conversion at the end of mitosis. Overall, this study provides a comprehensive understanding of how the maturing daughter centriole progressively disengages from its mother through multiple maturation steps, to ensure its complete structure and conversion into an independent centrosome.

cell biology↗

Flow zoometry of Drosophila

Drosophila serves as a highly valuable model organism across numerous fields including genetics, immunology, neuroscience, cancer biology, and developmental biology. Central to Drosophila-based biological research is the ability to perform comprehensive genetic or chemical screens. However, this research is often limited by its dependence on laborious manual handling and analysis, making it prone to human error and difficult to discern statistically significant or rare events amid the noise of individual variations resulting from genetic and environmental factors. In this article we present flow zoometry, a whole-animal equivalent of flow cytometry for large-scale, individual-level, high-content screening of Drosophila. Our flow zoometer automatically clears the tissues of Drosophila melanogaster, captures three-dimensional (3D) multi-color fluorescence tomograms of single flies with single-cell volumetric resolution at an unprecedented throughput of over 1,000 animals within 48 hours (24 hr for clearing; 24 hr for imaging), and performs AI-enhanced data-driven analysis - a task that would traditionally take months or years with manual techniques. To demonstrate its broad applications, we employed the flow zoometer in various laborious screening assays, including those in toxicology, genotyping, and tumor screening. Flow zoometry represents a pivotal evolution in high-throughput screening technology: previously from molecules to cells, now from cells to whole animals. This advancement serves as a foundational platform for "statistical spatial biology", to improve empirical precision and enable serendipitous discoveries across various fields of biology.

bioengineering↗

Comparable analysis of multiple DNA double-strand break repair pathways in CRISPR-mediated endogenous tagging

CRISPR-mediated endogenous tagging, utilizing the homology-directed repair (HDR) of DNA double-strand breaks (DSBs) with exogenously incorporated donor DNA, is a powerful tool in biological research. Inhibition of the non-homologous end joining (NHEJ) pathway has been proposed as a promising strategy for improving the low efficiency of accurate knock-in via the HDR pathway. However, the influence of alternative DSB repair pathways on gene knock-in remains to be fully explored. In this study, our long-read amplicon sequencing analysis reveals various patterns of imprecise repair in CRISPR/Cas-mediated knock-in, even under conditions where NHEJ is inhibited. Suppression of the microhomology-mediated end joining (MMEJ) or the single strand annealing (SSA) repair mechanisms leads to a reduction in distinct patterns of imprecise repair, thereby elevating the efficiency of accurate knock-in. Furthermore, a novel reporter system shows that the SSA pathway contributes to a specific pattern of imprecise repair, known as asymmetric HDR. Collectively, our study uncovers the involvement of multiple DSB repair pathways in CRISPR/Cas-mediated gene knock-in and proposes alternative approaches to enhance the efficiency of precise gene knock-in.

genomics↗

An antioxidant screen identifies ascorbic acid for prevention of light-induced mitotic prolongation in live cell imaging

Phototoxicity is an important issue in fluorescence live imaging of light-sensitive cellular processes such as mitosis, especially in high spatiotemporal resolution microscopy that often requires high-intensity illumination. Among several approaches to reduce phototoxicity, the addition of antioxidants to the imaging media has been used as a simple and effective method. However, it remains unknown what are the optimal antioxidants that could prevent phototoxicity-induced defects during mitosis in fluorescence live cell microscopy. In this study, we analyzed the impact of phototoxicity on the mitotic progression in fluorescence live imaging of human diploid cells and performed a screen to identify the most efficient antioxidative agents that reduce it. Quantitative analysis shows that high amounts of light illumination cause various mitotic defects such as prolonged mitosis and delays of chromosome alignment and centrosome separation. Among several antioxidants known to reduce cellular phototoxicity, our screen reveals that ascorbic acid significantly alleviates these phototoxic effects in mitosis. Furthermore, we demonstrate that the addition of ascorbic acid to the imaging media enables fluorescence imaging of mitotic events at very high temporal resolution without obvious photodamage. Thus, this study provides a simple and practical method to effectively reduce the phototoxic effects on mitotic processes in fluorescence live cell imaging.

cell biology↗

ssDNA is not superior to dsDNA as long HDR donors for CRISPR-mediated endogenous gene tagging in human diploid cells

Recent advances in CRISPR technology have enabled us to perform gene knock-in in various species and cell lines. CRISPR-mediated knock-in requires donor DNA which serves as a template for homology-directed repair (HDR). For knock-in of short sequences or base substitutions, ssDNA donors are frequently used among various other forms of HDR donors, such as linear dsDNA. However, for insertion of long transgenes such as fluorescent reporters in human cells, the optimal type of HDR donors remains unclear. In this study, we established a simple and efficient CRISPR-mediated knock-in method for long transgenes using linear dsDNA and ssDNA donors, and systematically compared the performance of these two donors for endogenous gene tagging in human non-transformed diploid cells. Quantification using flow cytometry revealed higher efficiency of fluorescent tagging with dsDNA donors than with ssDNA. By analyzing knock-in outcomes using long-read amplicon sequencing and a classification framework, a variety of mis-integration events were detected regardless of the donor type. Importantly, the ratio of precise insertion was higher with dsDNA donors than with ssDNA. Moreover, in off-target integration analyses, dsDNA and ssDNA were comparably prone to non-homologous integration. These results indicate that ssDNA is not superior to dsDNA as long HDR donors for gene knock-in in human cells.

cell biology↗

Quantitative analysis of CRISPR-del for complete gene knockout in human diploid cells

The advance of CRISPR/Cas9 technology has enabled us easily to generate gene knockout cell lines by introducing insertion/deletion mutations (indels) at the target site via the error-prone non-homologous end joining repair system. Frameshift-promoting indels can disrupt gene functions by generation of a premature stop codon. However, there is growing evidence that targeted genes are not always knocked-out by the indel-based gene disruption. In this study, we established a pipeline of CRISPR-del, which induces a large chromosomal deletion by cutting two different target sites, to perform "complete" gene knockout efficiently in non-transformed human diploid RPE1 cells. By optimizing several procedures, the CRISPR-del pipeline allowed us to generate knockout cell lines harboring bi-allelic large chromosomal deletions in a high-throughput manner. Quantitative analyses show that the frequency of gene deletion with this approach is much higher than that of conventional CRISPR-del methods. The lengths of the deleted genomic regions demonstrated in this study are longer than those of 95% of the human protein-coding genes. Furthermore, the pipeline enables the generation of a model cell line having a bi-allelic cancer-associated chromosomal deletion. Overall, these data lead us to propose that the CRISPR-del pipeline is a high-throughput approach for performing "complete" gene knockout in RPE1 cells.

cell biology↗

SCFFbxw5 targets MCAK in G2/M to facilitate ciliogenesis in the following cell cycle

The microtubule depolymerase Kif2C/MCAK plays important roles in various cellular processes and is frequently overexpressed in different cancer types. Despite the importance of its correct abundance, remarkably little is known about how MCAK levels are regulated in cells. Using comprehensive screening on protein microarrays, we identified 161 candidate substrates of the multi-subunit ubiquitin E3 ligase SCFFbxw5, including MCAK. In vitro reconstitution assays demonstrate that MCAK and its closely related orthologs Kif2A and Kif2B become efficiently polyubiquitylated by neddylated SCFFbxw5 and Cdc34, without requiring preceding modifications. In cells, SCFFbxw5 targets MCAK for proteasomal degradation specifically during G2/M. While this seems largely dispensable for mitotic progression, loss of Fbxw5 leads to increased MCAK levels at basal bodies, which impair formation of primary cilia in the following G1. We have thus identified a novel regulatory event of ciliogenesis that occurs already within the G2/M phase of the preceding cell cycle.

cell biology↗

Suppression of amyloid-β secretion from neurons by cis-9, trans-11-octadecadienoic acid, an isomer of conjugated linoleic acid

Conjugated linoleic acid (CLA) comprises several geometric and positional isomers of the parental linoleic acid (LA). Two of the isomers, cis-9, trans-11 CLA (c9,t11 CLA) and trans-10, cis-12 CLA (t10,c12 CLA) exert various biological activities. However, the effect of CLA on generation of neurotoxic amyloid-{beta} (A{beta}) protein remains unclear. We found that c9,t11CLA significantly suppressed generation of A{beta} in primary cultures of mouse neurons. CLA treatment did not affect the levels of {beta}-site APP-cleaving enzyme 1 (BACE1), a component of active {gamma}-secretase complex presenilin 1 amino-terminal fragment (PS1 NTF), or A{beta} protein precursor (APP) in cultured neurons. BACE1 activity in lysate of neurons treated with c9,t11 CLA, but not t10,c12 CLA, decreased slightly, although c9,t11 CLA did not directly affect the activity of recombinant BACE1. Interestingly, localization of BACE1 and APP in early endosomes increased in neurons treated with c9,t11 CLA; concomitantly, the localization of both proteins was reduced in late endosomes, where APP is predominantly cleaved by BACE1. c9,t11 CLA and t10,c12 CLA appeared to be incorporated into membrane phospholipids, as the level of CLA-containing lysophosphatidylcholine (CLA-LPC) increased dramatically in neurons incubated with CLA. Taken together, our findings indicate that accumulation of c9,t11 CLA-LPC, but not t10,c12 CLA-LPC, in neuronal membranes suppresses amyloidogenic cleavage of APP, thereby contributing to preservation of brain neurons by suppressing neurotoxic A{beta} production in aged subjects.

biochemistry↗

Cep57 and Cep57L1 cooperatively maintain centriole engagement during interphase to ensure proper centriole duplication cycle

Centrioles duplicate in the interphase only once per cell cycle. Newly formed centrioles remain associated with their mother centrioles. The two centrioles disengage at the end of mitosis, which licenses centriole duplication in the next cell cycle. Therefore, timely centriole disengagement is critical for the proper centriole duplication cycle. However, the mechanisms underlying centriole engagement during interphase are poorly understood. Here, we show that Cep57 and Cep57L1 cooperatively maintain centriole engagement during interphase. Co-depletion of Cep57 and Cep57L1 induces precocious centriole disengagement in the interphase without compromising cell cycle progression. The disengaged daughter centrioles convert into centrosomes during interphase in a Plk1-dependent manner. Furthermore, the centrioles reduplicate and the centriole number increases, which results in chromosome segregation errors. Overall, these findings demonstrate that the maintenance of centriole engagement by Cep57 and Cep57L1 during interphase is crucial for the tight control of centriole copy number and thus for proper chromosome segregation.

cell biology↗

DONSON, a gene responsible for microcephalic primordial dwarfism, ensures proper centriole duplication cycle by maintaining centriole engagement during interphase.

Microcephalic primordial dwarfism (MPD) is a genetic disorder characterized by short stature and microcephaly. MPD-related genes are known to regulate centrosome biogenesis, DNA replication or the DNA damage response. Although some of the MPD-related proteins that are implicated in DNA replication localize to centrosomes, how these proteins affect centrosome biogenesis remains mostly elusive. Here, we revisit the potential function of these DNA replication mediators in human centrosome biogenesis. Among these proteins, depletion of DONSON leads to excessive number of centrosomes in interphase, caused by precocious centriole disengagement. Such disengaged centrioles are converted to centrosomes, followed by centriole reduplication during interphase. These extra centrosomes lead to abnormal spindle formation and chromosome segregation errors. Importantly, similar defects are observed in MPD patients cells with DONSON mutations, suggesting a possible cause of the disease. Overall, these results indicate that DONSON is involved in regulating the centriole duplication cycle by ensuring the maintenance of centriole engagement during interphase.

cell biology↗