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Matsumoto, I.

Publications and source records attributed to Matsumoto, I..

10 recordsLinked to original sources

Circulating miR-1285-3p promotes age-associated B cell differentiation through the OXPHOS-IKZF2 axis in SLE

Age-associated B cells (ABCs) expand in systemic lupus erythematosus (SLE) and contribute to pathogenic humoral immunity, but the mechanisms that restrain their differentiation remain unclear. Here, we identify the transcription factor IKZF2 (Helios) as a regulator that limits ABC differentiation. Transcriptomic and functional analyses showed that suppression of oxidative phosphorylation (OXPHOS) in B cells promoted ABC differentiation and was accompanied by reduced IKZF2 expression. Pharmacologic modulation of mitochondrial metabolism further demonstrated that OXPHOS inhibition promoted, whereas OXPHOS activation restrained, ABC differentiation. Integrative analyses revealed reduced IKZF2 expression in selected B cell subsets from patients with SLE. Functional suppression of IKZF2 enhanced ABC differentiation and attenuated the inhibitory effects of OXPHOS activation, indicating that IKZF2 mediates metabolic control of B cell fate. Mechanistically, IKZF2 restrained early ABC-associated gene programs, including ITGAX and TBX21. Circulating miR-1285-3p in small extracellular vesicles, elevated in SLE, suppressed OXPHOS and recapitulated these effects. Together, these findings identify an OXPHOS-IKZF2 axis that restrains pathogenic B cell differentiation and links extracellular microRNA-mediated metabolic stress to ABC formation in SLE. One-sentence summarySmall EV-associated miR-1285-3p in SLE promotes ABC differentiation by suppressing OXPHOS and relieving IKZF2-mediated restraint.

immunology↗

Gustatory-neuron-supplied R-spondin-2 is required for taste bud replenishment

Taste buds undergo continuous cell turnover throughout life, and taste cell replenishment relies strictly on innervation, a phenomenon first described almost 150 years ago. Recently, we provided evidence that R-spondin 2 (Rspo2) may be the long-sought gustatory neuron-supplied factor that regulates taste stem cell activity, via its interaction with taste stem/progenitor cell-expressed receptor Rnf43/Znrf3. Yet, whether gustatory-neuron-supplied Rspo2 is strictly required for taste tissue maintenance has not been resolved. Here, we set out to determine the necessity of gustatory-neuron-supplied Rspo2 in taste tissue homeostasis using genetic approaches. We used a mouse line that harbors the neomycin-resistance gene (NeoR) in one of the intron regions of the Rspo2 gene, which results in reduced expression of Rspo2. The number of taste buds is significantly reduced in these mice, compared to wild-type mice, in both anterior and posterior tongue. This phenotypic change was completely reversed by removing NeoR from the Rspo2 gene, thus making it normal. We also combined adeno-associated virus (AAV)-based delivery of Cre recombinase with a mouse line amenable to Cre-based ablation of the Rspo2 exons encoding the receptor-binding domains. Such deletion of Rspo2 in the nodose-petrosal-jugular ganglion complex led to nearly complete loss of taste buds in the circumvallate papilla. Thus, we demonstrate that Rspo2 is the long-sought gustatory-neuron-supplied factor that acts on taste stem cells to maintain taste tissue homeostasis. SignificanceWe have known for 150 years that innervation is required to induce and maintain cell replacement in taste buds. Until recently, the identity of the inducing factor produced by neurons was unknown. We have shown that R-spondin alone is sufficient to substitute for neuronal input to induce taste bud regeneration. Using a genetic loss-of-function approach, we now demonstrate that gustatory-neuron-expressed Rspo2 is required to maintain taste tissue homeostasis. Altogether, our work reveals that Rspo2 is the long-sought neuron-supplied factor that regulates the activity of taste stem/progenitor cells.

neuroscience↗

Metaplastic tuft cells transdifferentiate to neural-like progenitor cells in the progression of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) is partly initiated through the transdifferentiation of acinar cells to metaplastic ducts that act as precursors of neoplasia and cancer. Tuft cells are solitary chemosensory cells not found in the normal pancreas but arise in metaplasia and neoplasia, diminishing as neoplastic lesions progress to carcinoma. Metaplastic tuft cells (mTCs) function to suppress tumor progression through communication with the tumor microenvironment, but their fate during progression is unknown. To determine the fate of mTCs during PDA progression, we have created a lineage tracing model that uses a tamoxifen-inducible tuft-cell specific Pou2f3CreERT/+ driver to induce transgene expression, including the lineage tracer tdTomato or the oncogene Myc. mTC lineage trace models of pancreatic neoplasia and carcinoma were used to follow mTC fate. We found that mTCs, in the carcinoma model, transdifferentiate into neural-like progenitor cells (NRPs), a cell type associated with poor survival in PDA patients. Using conditional knock-out and overexpression systems, we found that Myc activity in mTCs is necessary and sufficient to induce this Tuft-to-Neuroendocrine-Transition (TNT).

cancer biology↗

Inflammation induces bitter taste oversensitization via epigenetic changes in Tas2r gene clusters

T2R bitter receptors, encoded by Tas2r genes, are not only critical for bitter taste signal transduction but also important for defense against bacteria and parasites. However, little is known about whether and how Tas2r gene expression are regulated. Here we show that, in an inflammation model mimicking bacterial infection, the expression of many Tas2rs are significantly up-regulated and mice displayed markedly increased neural and behavioral responses to bitter compounds. Using single-cell assays for transposase-accessible chromatin with sequencing (scATAC-seq), we found that the chromatin accessibility of Tas2rs was highly cell type specific and inflammation increased the accessibility of many Tas2rs. scATAC-seq also revealed substantial chromatin remodeling in immune response genes in taste tissue stem cells, suggesting potential long-term effects. Together, our results suggest an epigenetic mechanism connecting inflammation, Tas2r gene regulation, and altered bitter taste, which may explain heightened bitter taste that can occur with infections and cancer treatments.

neuroscience↗

Alveolar regeneration following viral infection is independent of tuft cells

Severe injuries following viral infection cause lung epithelial destruction with the presence of ectopic basal progenitor cells (EBCs), although the exact function of EBCs remains controversial. We and others previously showed the presence of ectopic tuft cells in the disrupted alveolar region following severe influenza infection. Here, we further revealed that the ectopic tuft cells are derived from EBCs. This process is amplified by Wnt signaling inhibition but suppressed by Notch inhibition. Further analysis revealed that p63-CreER labeled population de novo arising during regeneration includes alveolar epithelial cells when Tamoxifen was administrated after viral infection. The generation of the p63-CreER labeled alveolar cells is independent of tuft cells, demonstrating segregated differentiation paths of EBCs in lung repair. EBCs and ectopic tuft cells can also be found in the lung parenchyma post SARS-CoV-2 infection, suggesting a similar response to severe injuries in humans.

cell biology↗

Injury-induced pulmonary tuft cells are heterogenous, arise independent of key Type 2 cytokines, and are dispensable for dysplastic repair

While the lung bears significant regenerative capacity, severe viral pneumonia can chronically impair lung function by triggering dysplastic remodeling. The connection between these enduring changes and chronic disease remains poorly understood. We recently described the emergence of tuft cells within Krt5+ dysplastic regions after influenza injury. Using bulk and single cell transcriptomics, we characterized and delineated multiple distinct tuft cell populations that arise following influenza clearance. Distinct from intestinal tuft cells which rely on Type 2 immune signals for their expansion, neither IL-25 nor IL-4R signaling are required to drive tuft cell development in dysplastic/injured lungs. Furthermore, tuft cells were also observed upon bleomycin injury, suggesting that their development may be a general response to severe lung injury. While intestinal tuft cells promote growth and differentiation of surrounding epithelial cells, in the lungs of tuft cell deficient mice, Krt5+ dysplasia still occurs, goblet cell production is unchanged, and there remains no appreciable contribution of Krt5+ cells into more regionally appropriate alveolar Type 2 cells. Together, these findings highlight unexpected differences in signals necessary for lung tuft cell amplification and establish a framework for future elucidation of tuft cell functions in pulmonary health and disease.

cell biology↗

Tuft cell-produced cysteinyl leukotrienes and IL-25 synergistically drivelung type 2 inflammation

Aeroallergen sensing by airway epithelial cells can trigger pathogenic immune responses leading to chronic type 2 inflammation, the hallmark of airway diseases such as asthma. Airway tuft cells are specialized chemosensory epithelial cells and the dominant source of the epithelial cytokine IL-25 in the trachea and of cysteinyl leukotrienes (CysLTs) in the naive murine nasal mucosa. The interaction of IL-25 and CysLTs and the contribution of tuft cell-derived CysLTs to the development of allergen-triggered inflammation in the airways has not been clarified. Here we show that inhalation of LTC4 in combination with a subthreshold dose of IL-25 leads to dramatic synergistic induction of type 2 inflammation throughout the lungs, causing rapid eosinophilia, dendritic cell (DC) and inflammatory type 2 innate lymphoid cell (ILC2) expansion, and goblet cell metaplasia. While lung eosinophilia is dominantly mediated through the classical CysLT receptor CysLT1R, type 2 cytokines and activation of innate immune cells require signaling through both CysLT1R and CysLT2R. Tuft cell-specific deletion of the terminal enzyme requisite for CysLT production, Ltc4s, was sufficient to reduce both the innate immune response in the lung - eosinophilia, KLRG1+ ILC2 activation and DC recruitment - and the systemic immune response in the draining lymph nodes after inhalation of the mold aeroallergen Alternaria. Our findings identify surprisingly potent synergy of CysLTs and IL-25 downstream of aeroallergen-trigged activation of airway tuft cells leading to a highly polarized type 2 immune response and further implicate airway tuft cells as powerful modulators of type 2 immunity in the lungs. One Sentence SummaryTuft cells produce two highly synergistic mediators: LTC4 and IL-25 to cooperatively induce allergen-driven airway inflammation.

immunology↗

Insulin-dependent maturation of newly generated olfactory sensory neurons after injury

Loss of olfactory sensory neurons (OSNs) after injury to the olfactory epithelium (OE) triggers the generation of OSNs that are incorporated into olfactory circuits to restore olfactory sensory perception. This study addresses how insulin receptor-mediated signaling affects the functional recovery of OSNs after OE injury. Insulin levels were reduced in mice by ablating the pancreatic beta cells via streptozotocin injections. These streptozotocin-induced diabetic and control mice were then intraperitoneally injected with the olfactotoxic drug methimazole to selectively ablate OSNs. The OE of diabetic and control mice regenerated similarly until day 14 after injury. Thereafter, the OE of diabetic mice contained fewer mature and more apoptotic OSNs than control mice. Functionally, diabetic mice showed reduced electro-olfactogram responses and their olfactory bulbs had fewer c-Fos-active cells following odor stimulation, as well as performed worse in an odor-guided task compared to control mice. Insulin administered intranasally during day 8 to 13 after injury was sufficient to rescue recovery of OSNs in diabetic mice compared to control levels, while insulin administration between days 1 - 6 did not. During this critical time window on day 8 - 13 after injury, insulin receptors are highly expressed and intranasal application of insulin receptor antagonist inhibits regeneration. Furthermore, an insulin-enriched environment could facilitate regeneration even in non-diabetic mice. These results indicate that insulin facilitates the regeneration of OSNs after injury and suggest a critical stage during recovery (8 - 13 days after injury) during which the maturation of newly generated OSNs is highly dependent on and promoted by insulin. Significance StatementAlthough insulin receptor signaling is known to influence on cellular processes such as proliferation and apoptosis, it is poorly understood whether the insulin influences the regeneration of olfactory sensory neurons (OSNs) after injury. We compared the maturation processes of new OSNs after the methimazole-induced loss of pre-existing OSNs between diabetic and control mice. The results show that the regeneration of new OSNs depend on sufficient insulin levels during a specific temporal window, when insulin receptor expression is highly upregulated. Furthermore, an insulin-enriched environment via nasal insulin application during the critical period facilitates OSNs regeneration even in non-diabetic mice. The present results have implications for intranasal application of insulin as potential clinical therapeutics to facilitate OSNs regeneration after the injury.

neuroscience↗

Tuft cells restrain pancreatic tumorigenesis through paracrine eicosanoid signaling

Despite numerous advances in our understanding of pancreatic ductal adenocarcinoma (PDA) genetics and biology, this disease is expected to become the second leading cause of cancer-related U.S. deaths within the next few years. Incomplete understanding of how it arises precludes development of early detection and interception strategies to improve therapeutic outcomes. Acinar to ductal metaplasia involving genesis of tuft cells is one early step in PDA formation, but their functional significance has remained obscure due to their rarity and a lack of methods and relevant animal models for their molecular and functional analysis. Here, we show that deletion of tuft cell master regulator Pou2f3 eliminates pancreatic tuft cells and increases fibrosis, alters immune cell activation, and accelerates disease progression. We demonstrate that tuft cell expression of the prostaglandin D2 synthase Hpgds restrains pancreatic disease progression in early stages by inhibiting stromal activation. Analyses of human data sets are consistent with mouse studies. We propose that tuft cells and, by inference, the associated metaplastic lesions, play a protective role early in pancreatic tumorigenesis. SignificanceWe find that tuft cell formation in response to oncogenic Kras is protective and restrains tumorigenesis through local production of anti-inflammatory substances, including paracrine prostaglandin D2 signaling to the stroma. Our findings establish tuft cells as a metaplasia-induced tumor suppressive cell type.

cancer biology↗

SMAD3 Determines Conventional versus Plasmacytoid Dendritic Cell Fates

Transforming growth factor (TGF)-{beta} plays crucial roles in differentiation of dendritic cells (DC). However, molecular mechanisms how TGF-{beta} regulates DC differentiation remain largely unknown. Here, we show that selective repression of one of the TGF-{beta} receptor-regulated SMADs (R-SMADs), SMAD3 directs conventional DC (cDC) differentiation, whereas maintenance of SMAD3 is indispensable for plasmacytoid DC (pDC) differentiation. Expression of SMAD3 was specifically downregulated in CD115+ common DC progenitor (CDP), pre-cDCs and cDCs. SMAD3 deficient mice showed a significant reduction in pre-pDCs and pDCs with increased CDP, pre-cDCs and cDCs. SMAD3 upregulated the pDC-related genes: SPI-B, E2-2 and IKAROS, while it repressed FLT3 and the cDC-related genes: IRF4 and ID2. STAT3 and a SMAD transcriptional co-repressor, c-SKI repressed SMAD3 for cDC differentiation, whereas canonical SMAD-mediated TGF-{beta} signalling maintained SMAD3 for pDC differentiation. Thus, SMAD3 is the pivotal determinant to bifurcate cDC and pDC differentiation in the steady-state condition.

immunology↗