Biology subjects

Higashi, Y.

Publications and source records attributed to Higashi, Y..

8 recordsLinked to original sources

bioRxiv2025

LARP6 Promotes Features of Plaque Stability and Smooth Muscle Cell Survival in Atherosclerosis

IntroductionAcute plaque rupture or erosion followed by luminal thrombosis is a major cause of myocardial infarction and sudden cardiac death. Vulnerable plaques are characterized by a thin fibrous cap and reduced numbers of smooth muscle cells (SMCs). SMCs are essential for plaque stability, as they synthesize collagen and support fibrous cap structure. Our previous work demonstrated that insulin-like growth factor-1(IGF-1) enhances plaque stability and upregulates La ribonucleoprotein domain family member 6 (Larp6), a collagen mRNA-binding protein in SMCs. However, the specific role of Larp6 in atherosclerotic plaque stability remains undefined. MethodsIn vitro, human aortic SMCs (hAoSMCs) were used to investigate the molecular mechanism underlying IGF-1 regulation of LARP6. Using the Myh11 promotor we generated SMC specific Larp6 overexpression mice on an ApoE-/- background (SMC-Larp6) to assess effects on plaque stability. Bulk RNA sequencing data from human atherosclerotic plaques (GSE120521) were analyzed to compare stable and vulnerable plaques. ResultsIGF-1 regulates LARP6 through phosphorylation and downregulation of microRNAs. Plaques from SMC-Larp6 mice exhibited a significantly higher collagen content, accompanied by a thicker fibrous cap and a smaller necrotic core, increased presence of SMCs, without changes in overall plaque burden compared to controls. LARP6 overexpression in hAoSMCs significantly increased cell proliferation and survival under oxidative stress and promoted collagen accumulation by enhancing collagen synthesis. RNA sequencing analysis of human atherosclerotic plaques revealed reduced expression of LARP6 and downregulation of extracellular matrix-related pathways in unstable plaques, underscoring the clinical relevance of these findings. ConclusionsLarp6 overexpression promotes SMC survival, collagen synthesis and features of plaque stability under atherosclerotic conditions. These findings suggest that Larp6 is a potential therapeutic target for stabilization of atherosclerotic plaques.

pathology↗

bioRxiv2025

ZEB2 signaling is essential for ureteral smooth muscle cell differentiation and maintenance

Mowat-Wilson Syndrome (MWS) is a multiple congenital anomaly syndrome caused by mutations in the ZEB2, which plays a critical role in cell fate determination and differentiation during development. Congenital anomalies of the kidney and urinary tract (CAKUT) have been reported in MWS patients. However, the role of ZEB2 in urinary tract development and the cellular and molecular mechanism underlining the CAKUT phenotypes in MWS remains unknown. We performed ZEB2 protein expression analysis in the developing mouse ureter. We generated Zeb2 ureteral mesenchyme-specific conditional knockout mice by crossing Zeb2 floxed mice with Tbx18Cre mice (Zeb2 cKO) and analyzed the urinary tract phenotypes in Zeb2 cKO mice and wild-type littermate controls by gross and histological examination. Ureteral cellular and molecular phenotypes were studied using TAGLN, ACTA2, FOXD1, POSTN, CDH1, TBX18, and SOX9 ureteral cell-specific markers. We found that ZEB2 is expressed in TBX18+ ureteral mesenchymal cells during mouse ureter development. Deletion of Zeb2 in developing ureteral mesenchymal cells causes hydroureter and hydronephrosis phenotypes, leading to obstructive uropathy, kidney failure, and early mortality. Cellular and molecular marker analyses showed that the TAGLN+ACTA2+ ureteral smooth muscle cells (SMCs) layer is not formed in Zeb2 cKO mice at E15.5, but the FOXD1+ and POSTN+ tunica adventitia cells layer is significantly expanded compared to wild-type controls. CDH1+ urothelium cells are reduced considerably in the Zeb2 cKO ureters at E15.5. Mechanistically, we found that Zeb2 cKO mice have significantly decreased TBX18 expression but an increased SOX9 expression in the developing ureter at E14.5 and E15.5 compared to wild-type littermate controls. Our results show that ZEB2 is essential for ureter development by maintaining ureteral mesenchymal cell differentiation into normal ureteral SMCs. Our study also shed new light on the pathological mechanism underlying the developmental abnormalities of the urinary tract phenotypes in MWS patients. Author SummaryHydroureter and hydronephrosis are common congenital anomalies with high incidence (1:100 to 1:500) that can lead to obstructive uropathy and renal failure in the pediatric population. Mowat-Wilson Syndrome (MWS), caused by heterozygous mutations in the ZEB2 gene, is a genetic disease with multiple congenital developmental defects, including hydroureter and hydronephrosis. However, the molecular function of ZEB2 in ureter development and pathogenesis of hydroureter and hydronephrosis remains unknown. Here, we show that ZEB2 is expressed in the developing ureteral mesenchymal cells, and deletion of ZEB2 in ureteral mesenchymal cells leads to ureteral smooth muscle cell loss, which is replaced by tunica adventitia cells causing hydroureter and hydronephrosis phenotype. Hence, our work not only demonstrates the critical role of ZEB2 in ureter development but also provides molecular mechanisms of urinary tract anomalies in MWS patients.

developmental biology↗

bioRxiv2024

Adaptive evolution of sesquiterpene deoxyphomenone in mycoparasitism by Hansfordia pulvinata associated with horizontal gene transfer from Aspergillus species

Leaf mold caused by the ascomycete fungus Cladosporium fulvum is a devastating disease of tomato plants. The mycoparasitic fungus Hansfordia pulvinata is an effective biocontrol agent that parasitizes C. fulvum hyphae on leaves and secretes 13-deoxyphomenone, an eremophilane-type sesquiterpene, which was also identified as a sporulation-inducing factor in Aspergillus oryzae. Here, we identified deoxyphomenone biosynthesis (DPH) gene clusters conserved in both H. pulvinata and Aspergillus section Flavi including A. oryzae and A. flavus. Functional disruption of DPH1 orthologous genes encoding sesquiterpene cyclase in H. pulvinata, A. oryzae and its close relative A. flavus revealed that deoxyphomenone in H. pulvinata had exogenic antifungal activity against the host fungus C. fulvum and controlled endogenic sporulation in Aspergillus species. Deoxyphomenone also inhibited mycelial growth of C. fulvum and the non-host tomato pathogen Pseudocercospora fuligena. Complete DPH clusters, highly similar to those in H. pulvinata, were exclusive to Aspergillus section Flavi, while species in other Aspergillus sections contained fragmented DPH clusters. A comparative genomics analysis revealed that these DPH gene clusters share a common origin and are horizontally transferred across large taxonomic distances from an ancestor of Aspergillus to H. pulvinata. Our results suggest that, after horizontal transfer, H. pulvinata maintained the DPH cluster as the inhibitory effect of deoxyphomenone on spore germination and mycelial growth contributed to its mycoparasitism on the host fungus C. fulvum.

microbiology↗

bioRxiv2022

INSULIN-LIKE GROWTH FACTOR I REDUCES CORONARY ATHEROSCLEROSIS IN PIGS WITH FAMILIAL HYPERCHOLESTEROLEMIA

ObjectiveAlthough murine models of coronary atherosclerotic disease (CAD) have been used extensively to determine mechanisms, limited new therapeutic options have emerged. Pigs with familial hypercholesterolemia (FH pigs) develop complex coronary atheromas that are almost identical to human lesions. We reported previously that insulin-like growth factor 1 (IGF-1) reduced aortic atherosclerosis and promoted features of stable plaque in a murine model. We tested IGF-1 effects in atherosclerotic FH pigs to consider use of IGF-1 to treat CAD in humans. FH pigs were administered with IGF-1 for 6 months. Atherosclerosis was quantified by serial intravascular ultrasound (IVUS) and histology, plaque composition - by immunohistochemistry. We used spatial transcriptomics (ST) analysis to identify global transcriptome changes in advanced plaque compartments and to obtain mechanistic insights into IGF-1 effects. ResultsIGF-1-injected FH pigs had 1.8-fold increase in total circulating IGF-1 levels compared to control. IGF-1 decreased relative coronary atheroma (IVUS) and lesion cross-sectional area (histology). IGF-1 induced vascular hypertrophy and reduced circulating triglycerides, markers of systemic oxidative stress and pro-atherogenic CXCL12 chemokine levels. IGF-1 increased fibrous cap thickness, and reduced necrotic core size, macrophage content, and cell apoptosis, changes consistent with promotion of a stable plaque phenotype. IGF-1 suppressed FOS/FOSB factors and gene expression of MMP9 and CXCL14 in plaque macrophages, suggesting possible involvement of these molecules in IGF-1s effect on atherosclerosis. ConclusionsIGF-1 reduced coronary plaque burden and promoted features of stable plaque in a pig model, providing support for consideration of clinical trials. ST profiling of plaques provided novel insights into potential mechanisms.

cell biology↗

bioRxiv2021

Excretion of triacylglycerol as a matrix lipid facilitating apoplastic accumulation of a lipophilic metabolite shikonin.

Plants produce a large variety of lipophilic metabolites, many of which are secreted by cells and accumulated in apoplasts. The mechanism of secretion remains largely unknown, because hydrophobic metabolites, which may form oil droplets or crystals in cytosol, inducing cell death, cannot be directly secreted by transporters. Moreover, some secondary metabolic lipids react with cytosolic components leading to their decomposition. Lipophilic metabolites should thus be solubilized by matrix lipids and compartmentalized by membrane lipids. The mechanism of lipophilic metabolite secretion was assessed using shikonin, a red naphthoquinone lipid, in Lithospermum erythrorhizon. Cell secretion of shikonin also involved the secretion of about 30% of triacylglycerol (TAG), composed predominantly of saturated fatty acids. Shikonin production was associated with the induction of large amounts of the membrane lipid phosphatidylcholine. Together with in vitro reconstitution, these findings suggest a novel role for TAG as a matrix lipid for the secretion of lipophilic metabolites.

plant biology↗

bioRxiv2021

Dynamic product-precursor relationships underlie cuticular lipid accumulation on maize silks

The hydrophobic cuticle is the first line of defense between aerial portions of a plant and the external environment. On maize silks, the cuticular cutin matrix is infused with cuticular lipids, consisting of a homologous series of very-long-chain fatty acids (VLCFAs), aldehydes, and hydrocarbons that serve as precursors, intermediates, and end-products of the elongation, reduction, and decarbonylation reactions of the hydrocarbon-producing pathway. To deconvolute the potentially confounding impacts of the silk microenvironment and silk development on the hydrocarbon-producing pathway, spatio-temporal cuticular lipid profiling was conducted on the agronomically important inbreds B73 and Mo17, and their reciprocal hybrids. Statistical interrogation via multivariate analyses of the metabolite abundances of the hydrocarbon-producing pathway demonstrate that the cellular VLCFA pool is positively correlated with the cuticular lipid metabolome, and this metabolome is primarily affected by the silk microenvironment and the plant genotype. Moreover, genotype has a major effect on the pathway, with increased cuticular hydrocarbon and concomitant reduction of cuticular VLCFA accumulation on B73 silks, suggesting that conversion of VLCFAs to hydrocarbons is more effective in B73 than Mo17. Statistical modeling of the ratios between cuticular hydrocarbons and cuticular VLCFAs reveals the complexity of the product-precursor ratio relationship, demonstrating a significant role of precursor chain length. Longer-chain VLCFAs are preferentially utilized as precursors for hydrocarbon biosynthesis. Collectively, these findings demonstrate maize silks as an effective and novel system for dissection of the complex dynamics of cuticular lipid accumulation in plants. One-sentence SummaryThe product-precursor ratios in the cuticular hydrocarbon-producing pathway are impacted by fatty acid precursor chain length, plant genotype and the spatio-temporal dynamic gradients of maize silks.

plant biology↗

bioRxiv2020

MS-DIAL 4: accelerating lipidomics using an MS/MS, CCS, and retention time atlas

To the EditorWe formulated mass spectral fragmentations of lipids across 117 lipid subclasses and included ion mobility tandem mass spectrometry (MS/MS) to provide a comprehensive lipidome atlas with retention time, collision cross section, and MS/MS information. The all-in-one solution from import of raw MS data to export of a common output format (mztab-M) was packaged in MS-DIAL 4 (http://prime.psc.riken.jp/) providing an enhanced standardized untargeted lipidomics procedure following lipidomics standards initiative (LSI) semi-quantitative definitions and shorthand notation system of lipid structures with a 1-2% estimated false discovery rate, which will contribute to harmonizing lipidomics data across laboratories to accelerate lipids research.

bioinformatics↗

bioRxiv2019

Transcriptome Analysis of Desquamative Interstitial Pneumonia (DIP)

Desquamative interstitial pneumonia (DIP) is a rare diffuse parenchymal lung disease of unclear etiology. A recent study showed that mice overexpressing granulocyte macrophage colony-stimulating factor (GM-CSF) in lungs develop DIP-like disease, suggesting that pulmonary GM-CSF may be involved in the pathogenesis of DIP. To determine if GM-CSF is involved in human DIP lungs, we performed transcriptome analysis on human DIP lung tissue. We also extended transcriptome analysis to respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), which has been thought to be in the same spectrum of disease. The analysis revealed that DIP has a distinct transcriptome profile compared to both RB-ILD and non-diseased lung controls. It also suggested that GM-CSF was a key upstream regulator in the DIP transcriptome and that the GM-CSF signaling pathway was highly activated in DIP tissue. Further bioinformatics analysis using xCell, a novel computational method that assesses enrichments of individual cell types based on gene expression, suggested that DIP is enriched for gene signatures of macrophages and other immune cells such as dendritic cells and B cells. In conclusion, our analysis shows that DIP is characterized by a GM-CSF signature, and thus GM-CSF is likely to be involved in the pathogenesis of DIP. Our analysis also suggests that immune cells other than alveolar macrophages, such as B cells, may also be involved in the pathogenesis of DIP.

molecular biology↗