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Biology subjects

Yano, M.

Publications and source records attributed to Yano, M..

11 recordsLinked to original sources

Highly plastic macrophage niches orchestrate acquired quiescence and reactivation in breast-cancer bone metastasis

Recurrence and metastasis remain major causes of cancer mortality, sustained by therapy-resistant micrometastatic cells. Bone is a frequent site of breast-cancer relapse, yet the cues that reawaken disseminated cells remain poorly defined. We identify a previously unrecognized, highly plastic CXCL16 macrophage population that integrates tumor-associated macrophage programs found in distant metastatic sites such as lung and brain with non-tumor disease-associated traits in bone marrow. These CXCL16 macrophages establish a transient niche that restrains disseminated cancer-cell proliferation. Single-cell transcriptomics delineate functional remodeling of myeloid niches within the bone metastatic microenvironment: a CXCL16 macrophage niche that transiently constrains metastatic growth, and G-CSF macrophage and neutrophil niches that reignite tumor outgrowth. In primary tumors, cancer-associated fibroblasts (CAFs) aberrantly secrete G-CSF in response to cancer-cell signals, expanding G-CSF-receptor-positive subset of cancer cells with high metastatic potential. In advanced human bone metastases, CXCL16 macrophages localize to CAF-rich stroma but are excluded from cancer-cell clusters, indicating immune evasion. Together, these findings uncover CAF-bone-marrow cross-talk as a therapeutic target linking stromal inflammation, immune remodeling, and metastatic progression.

cancer biology↗

Elucidation of the mechanism of byproduct DNA synthesis in whole-transcript amplification by poly-A tagging and development of its specific suppression

Poly-A tagging is a whole-transcript amplification method that uses terminal transferase to add poly-A to single-stranded cDNA in a non-template-dependent manner, and is used in highly sensitive single-cell RNA-seq. However, this method has long been reported to amplify byproduct DNA derived from reverse-transcription primers, particularly under conditions of low RNA abundance, leading to experimental complexity and reduced accuracy in quantifying gene expression. In this study, we elucidated the mechanism by which byproduct DNA is amplified at the molecular level and developed a new strategy of suppressing it named Suppression Tagging (SupTag). SupTag makes use of TdT, which has extremely low extension efficiency at the 3' recessive end, to stabilize dA/dT base pairs and inhibit poly-A extension of oligo-dT primers, thereby preventing the formation of precursor DNA for byproduct DNA. We demonstrated that SupTag can specifically suppress byproduct DNA using chemicals such as tetramethylammonium chloride (TMAC), modified nucleotides (e.g., 2F-dATP), and Super T-modified reverse-transcription primers. SupTag improves usability by streamlining purification processes and prevents reductions in sequence read output and quantitative sensitivity caused by byproduct DNA. Additionally, SupTag demonstrated the ability to suppress byproduct DNA amplification without using suppression PCR and is compatible with cDNA amplification introducing different adapter sequences at both ends. This study presents a novel suppression method based on the mechanism of amplification of byproduct DNA in the poly-A tagging method, providing a practical technology enabling high-precision transcriptomic analysis from low-abundance RNA.

molecular biology↗

CRISPR/Cas9-mediated genome editing reveals the involvement of a polyphenol oxidase in the shikonin-specific biosynthesis in Lithospermum erythrorhizon

Shikonin, a 1,4-naphthoquinone derivative produced by several Boraginaceae species, exhibits unique pharmacological properties and is used as a natural dye. The regulatory factors of shikonin production have been demonstrated using a cell culture system of Lithospermum erythrorhizon. Among these factors, copper is known to be the strongest enhancer of shikonin production. Although shikonin biosynthesis has been studied for over 40 years, the steps of naphthalene ring formation are still unknown, as is the reason for the effect of copper. In this study, we explored candidate genes associated with shikonin production using a PCR-select subtraction experiment. Polyphenol oxidase (PPO), a dicopper-dependent oxidoreductase, was highlighted because it showed synchronous expression with shikonin production. Transcriptome analysis of hairy roots and cultured cells of this plant revealed that, of the five PPO genes expressed in L. erythrorhizon, only PPO1 showed a strong correlation with shikonin production. Next, we generated genome-edited hairy roots of LePPO1 using CRISPR/Cas9-mediated mutagenesis to analyze its impact on shikonin derivative and other specialized metabolite production. The results showed that shikonin content was markedly reduced in all LePPO1-ge lines. Interestingly, the content of deoxyshikonofuran, a hydroquinone derivative and shunt product that branches after GHQ-3''-OH in the shikonin biosynthetic pathway, remained unaffected in the LePPO1-ge lines. These findings suggest that LePPO1 participates in naphthalene ring formation and explain why a copper ion is crucial for shikonin biosynthesis.

biochemistry↗

Dynamic activity of Erg promotes aging of the hematopoietic system

Hematopoiesis changes to adapt to the physiology of development and aging. Temporal changes in hematopoiesis parallel age-dependent incidences of blood diseases. Several heterochronic regulators of hematopoiesis have been identified, but how the master transcription factor (TF) circuitry of definitive hematopoietic stem cells (HSCs) adapts over the lifespan is unknown. Here, we show that expression of the ETS family TF Erg is adult-biased, and that programmed upregulation of Erg expression during juvenile to adult aging is evolutionarily conserved and required for complete implementation of adult patterns of HSC self-renewal and myeloid, erythroid, and lymphoid differentiation. Erg deficiency maintains fetal transcriptional and epigenetic programs, and persistent juvenile phenotypes in Erg haploinsufficient mice are dependent on deregulation of the fetal-biased TF Hmga2. Finally, Erg haploinsufficiency in the adult results in fetal-like resistance to leukemogenesis. Overall, we identify a mechanism whereby HSC TF networks are rewired to specify stage-specific hematopoiesis, a finding directly relevant to age-biased blood diseases. SUMMARYThe hematopoietic system undergoes a process of coordinated aging from the juvenile to adult states. Here, we find that expression of ETS family transcription factor Erg is temporally regulated. Impaired upregulation of Erg during the hematopoietic maturation results in persistence of juvenile phenotypes.

developmental biology↗

Scg2 drives reorganization of the corticospinal circuit with spinal premotor interneurons to recover motor function after stroke

Brain injuries such as stroke damage neural circuitry and lead to functional deficits. Spared motor pathways are often reorganized and contribute to functional recovery; however, the connectivity and molecular mechanisms that drive the reorganization are largely unknown. Here, we demonstrate structural and functional connectivity reformed by spared corticospinal axons after stroke and determine a key secretory protein that drives the reorganization. We first found that corticospinal axons innervate specific areas of the denervated cervical cord after stroke. Anatomical and photometric analyses reveal that the axons reconnect to premotor V2a interneurons. Kinematic analyses of forelimb movements and chemogenetic silencing reveal their contribution to motor recovery. Translated mRNA expression analyses of V2a interneurons and astrocytes in the denervated cervical cord reveal diverse transcripts upregulated in the rewiring process. In particular, a secretory protein Scg2 is upregulated by injury-induced purinergic ATP signals and rehabilitative training-induced neural activity and possesses an ability to promote axon growth via cAMP and S6 signaling. Scg2 overexpression in the denervated cervical cord enhances axon rewiring, while the Scg2 knockdown attenuates it. The present data reveal the neural substrate and molecular mechanism essential to induce reorganization and recovery of the motor system, providing fundamental therapeutic targets for CNS injuries.

neuroscience↗

The Neurophysiological Modality Effect in Native and Second Language Processing: An ERP Study

Experimental psychology has long discussed the modality effect, whereby the stimulus modality significantly affects retention of the information presented. In neurolinguistics, however, the effect of stimulus modality on language processing has gained little attention. We conducted a multi-modal event-related potential (ERP) experiment on both native and non-native Spanish speakers to investigate the possibility of a neurophysiological modality effect in language processing. Using morphosyntactically violated and orthographically/phonologically violated stimuli, we elicited a robust N400 and P600 in native speakers. We showed that the N400 has consistent features across modalities, while the P600 has modality-specific features. Specifically, the auditory evoked P600 was characterized by a more gradual slope and a later peak than the visual evoked P600. We discuss this in detail along with other modality effects observed post sensory perception. Among second language (L2) learner groups, those with higher proficiency exhibited more nativelike neurophysiological responses in both modalities when compared to those with lower proficiency. We additionally observed fewer modality-specific differences in low proficiency learners than in higher proficiency learners suggesting that modality-specific specialization in language processing comes with increased proficiency. We further discuss the question of modality-specific differences in the process of neurophysiological nativization, whereby L2 learners ERPs become increasingly on nativelike.

neuroscience↗

Isoform-specific mutation in Dystonin-b gene causes late-onset protein aggregate myopathy and cardiomyopathy

Dystonin (DST), which encodes cytoskeletal linker proteins, express three tissue-selective isoforms: neural DST-a, muscular DST-b, and epithelial DST-e. DST mutations cause different disorders including hereditary sensory and autonomic neuropathy 6 (HSAN-VI) and epidermolysis bullosa simplex; however, etiology of the muscle phenotype in DST-related diseases has been unclear. Because DST-b contains all of the DST-a-encoding exons, known HSAN-VI mutations could affect both DST-a and DST-b isoforms. To investigate the specific function of DST-b in striated muscles, we generated a Dst-b-specific mutant mouse model harboring a nonsense mutation. Dst-b mutant mice exhibited late-onset protein aggregate myopathy and cardiomyopathy without neuropathy. We observed desmin aggregation, focal myofibrillar dissolution, and mitochondrial accumulation in striated muscles, which are common characteristics of myofibrillar myopathy. We also found nuclear inclusions containing p62, ubiquitin, and SUMO proteins with nuclear envelope invaginations as a unique pathological hallmark in Dst-b mutation-induced cardiomyopathy. RNA sequencing analysis revealed changes in expression of genes responsible for cardiovascular functions. In silico analysis identified DST-b alleles with nonsense mutations in populations worldwide, suggesting that some unidentified hereditary myopathy and cardiomyopathy are caused by DST-b mutations. Here, we demonstrate that the Dst-b isoform is essential for long-term maintenance of striated muscles.

pathology↗

In Vitro Proliferation and Long-Term Preservation of Functional Primary Rat Hepatocytes in Cell Fibers

Primary hepatocytes are essential cellular resource for drug screening and medical transplantation. Since culture systems for them have already succeeded in reconstituting the biomimetic microenvironment, acquiring additional capabilities both to expand primary hepatocytes and to handle them easily would be expected as progress to the next stage. This paper describes a culture system for primary rat hepatocytes that is equipped with scalability and handleability relying on cell fiber technology. Cell fibers are cell-laden core-shell hydrogel microfibers; in the core regions, cells are embedded in extracellular matrix proteins, cultured three-dimensionally, and exposed to soluble growth factors in the culture medium through the hydrogel shells. By encapsulating primary rat hepatocytes within cell fibers, we first demonstrated they increase in number while keeping their viability and their hepatic specific functions for up to thirty days of subsequent culture. Then, we demonstrated the potency of the primary rat hepatocytes that proliferate in cell fibers not only as cell-based sensors to detect drugs that damage hepatic functions and hepatocellular processes but also as transplants to improve the plasma albumin concentrations of congenital analbuminemia. Therefore, our culture system could serve for innovating strategies and promising developments in applying primary hepatocytes to both pharmaceutical and medical fields.

bioengineering↗

Non-invasive human skin transcriptome analysis using mRNA in skin surface lipids

Non-invasive acquisition of mRNA data from the skin would be extremely useful for understanding skin physiology and diseases. Inspired by the holocrine process, in which the sebaceous glands secrete cell contents into the sebum, we focused on the possible presence of mRNAs in skin surface lipids (SSLs). We found that measurable human mRNAs exist in SSLs, where sebum protects them from degradation by RNases. The AmpliSeq transcriptome analysis was modified to measure SSL-RNAs, and our results revealed that SSL-RNAs predominantly contained mRNAs derived from sebaceous glands, epidermis, and hair follicles. Analysis of SSL-RNAs non-invasively collected from patients with atopic dermatitis revealed significantly increased expression of inflammation-related genes and decreased expression of terminal differentiation-related genes, consistent with the results of previous reports. Further, we found that lipid synthesis-related genes were downregulated in the sebaceous glands of patients with atopic dermatitis. These results indicate that the analysis of SSL-RNAs is promising to understand the pathophysiology of skin diseases.

molecular biology↗

Identification of hub molecules of FUS-ALS by Bayesian gene regulatory network analysis of iPSC model: iBRN

Fused in sarcoma/translated in liposarcoma (FUS) is a causative gene of amyotrophic lateral sclerosis (ALS). Mutated FUS causes accumulation of DNA damage and cytosolic stress granule (SG) formation, thereby motor neuron (MN) death. However, key molecular aetiology remains unclear. Here, we applied a novel platform technology, iBRN, "Non-biased" Bayesian gene regulatory network analysis based on induced pluripotent stem cell (iPSC)-derived cell model, to elucidate the molecular aetiology using transcriptome of iPSC-derived MNs harboring FUSH517D. iBRN revealed "hub molecules", which strongly influenced transcriptome network, such as miR-125b-5p-TIMELESS axis and PRKDC for the molecular aetiology. Next, we confirmed miR-125b-5p-TIMELESS axis in FUSH517D MNs such that miR-125b-5p regulated several DNA repair-related genes including TIMELESS. In addition, we validated both introduction of miR-125b-5p and knocking down of TIMELESS caused DNA damage in the cell culture model. Furthermore, PRKDC was strongly associated with FUS mis-localization into SGs by DNA damage under impaired DNA-PK activity. Collectively, our iBRN strategy provides the first compelling evidence to elucidate molecular aetiology in neurodegenerative diseases. HighlightsO_LIA new platform technology, "iBRN", Bayesian gene regulatory network analysis based on iPSC cells C_LIO_LIiBRN identifies hub molecules to strongly influence the gene network in FUS-ALS C_LIO_LIPRKDC specifically acts as a guardian against FUS mis-localization during DNA damage stress C_LIO_LImiR-125b-5p-TIMELESS axis regulates DNA repair-related genes in FUS-ALS. C_LI

neuroscience↗

MCM10 compensates for Myc-induced DNA replication stress in breast cancer stem-like cells

Cancer stem-like cells (CSCs) are responsible for the drug resistance of tumors and recurrence while they experience DNA replication stress. However, the underlying mechanisms that cause DNA replication stress in CSCs and how they compensate for this stress remain unclear. Here we provide evidence that upregulated c-Myc expression induces stronger DNA replication stress in patient-derived breast CSCs than in differentiated cancer cells. Our results suggest critical roles for mini-chromosome maintenance protein 10 (MCM10), which is a firing (activating) factor of the DNA replication origins, to compensate for the DNA replication stress. Expression levels of MCM10 are upregulated in CSCs and maintained by c-Myc. c-Myc-dependent collisions may take place between RNA transcription and DNA replication machinery in nuclei, thereby causing DNA replication stress. MCM10 may activate dormant replication origins close to the collisions to ensure replication progression. Moreover, patient-derived breast CSCs were dependent on MCM10 for their maintenance even after enrichment for CSCs that were resistant to paclitaxel, the standard chemotherapeutic agent. In addition, MCM10 depletion decreased the growth of cancer cells but not normal cells. Therefore, MCM10 is likely to robustly compensate for DNA replication stress and facilitate genome duplication in the S-phase in cancer cells, which is more pronounced in CSCs. We provide a preclinical rationale to target the c-Myc-MCM10 axis to prevent drug resistance and recurrence.

cancer biology↗