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Miyoshi, E.

Publications and source records attributed to Miyoshi, E..

16 recordsLinked to original sources

Hypoxia reduces induced LRIG1 protein despite sustained mRNA induction in colorectal cancer organoids

LRIG1 is a negative regulator of receptor tyrosine kinase (RTK) signaling that promotes tumor suppression by driving degradation of EGFR and other RTKs. Inducing LRIG1 expression has therefore been proposed as a strategy to limit cancer cell survival under hypoxia. However, whether hypoxia itself affects LRIG1 expression remains unclear. Here, we investigated how hypoxia affects LRIG1 expression and protein abundance in human cancer datasets and colorectal cancer organoids. Analysis of The Cancer Genome Atlas data across gastrointestinal and other cancers revealed an inverse association between LRIG1 mRNA expression and a hypoxia gene signature that persisted after adjustment for global gene expression. We previously showed that BMPR inhibition induces LRIG1 and suppresses colorectal cancer organoid growth through LRIG1. Under hypoxia, this growth inhibition in colorectal cancer organoids was attenuated, and LRIG1 protein accumulation was reduced despite sustained mRNA induction. Pre-induced LRIG1 protein declined within 3 h of hypoxic exposure in organoids, and ectopically expressed LRIG1 similarly decreased in HEK293 cells. Pharmacological HIF1 inhibition did not prevent LRIG1 protein loss under hypoxia, whereas HIF1 stabilization did not reproduce it under normoxia, suggesting limited HIF1 involvement. Bafilomycin A1 restored LRIG1 protein levels, whereas chloroquine and the proteasome inhibitor MG132 did not, implicating a bafilomycin A1-sensitive lysosomal process. Notably, the hypoxia-induced decrease in LRIG1 was not accompanied by a decrease in total EGFR. These findings suggest that hypoxia limits LRIG1 protein induction, potentially constraining strategies that rely on LRIG1 induction in cancer treatment.

biochemistry↗

Prohaptoglobin Promotes Pancreatic Cancer Progression by sustaining YAP Activity

Background & AimsProhaptoglobin (proHp), a precursor of haptoglobin (Hp), has recently emerged as a cancer-associated biomarker, but its functional role in pancreatic cancer remains unclear. We investigated whether proHp promotes malignant phenotypes of pancreatic cancer and explored signaling pathways involved. MethodsSerum proHp was examined in patients with pancreatic cancer and healthy controls. HP expression in pancreatic tumors and cell lines was analyzed using transcriptomic datasets. ProHp function was evaluated using PSN1 HP knockout (HPKO) cells, exogenous proHp supplementation, xenograft models, and RNA sequencing of PSN1 wild-type and HPKO cells. YAP activity was assessed by target gene expression, subcellular localization, YAP overexpression, and inhibition of YAP-TEAD interaction. ResultsSerum proHp was significantly elevated in patients with pancreatic cancer, and a subset of tumors and pancreatic cancer cell lines showed HP expression comparable to liver, indicating a tumor-derived source of proHp. In PSN1 cells, HPKO reduced motility, whereas exogenous proHp partially rescued this defect and enhanced motility in additional pancreatic cancer cell lines. Wild-type PSN1 cells continued to proliferate beyond confluence and formed rapidly growing xenograft tumors, which were abolished in HPKO cells. At high density, wild-type cells maintained YAP-related gene expression and nuclear YAP despite Hippo activation, whereas HPKO exhibited reduced nuclear YAP, indicating noncanonical YAP regulation by proHp. YAP restoration in HPKO cells rescued high-density proliferation and cell motility, while a YAP-TEAD inhibitor selectively reduced high-density proliferation of wild-type but not HPKO cells. ConclusionProHp promotes pancreatic cancer progression in a context-dependent manner by sustaining YAP activity and enabling cells to partially overcome contact-dependent growth inhibition. SynopsisProhaptoglobin, a precursor of haptoglobin, is elevated in pancreatic cancer and produced by tumor cells. It promotes cell motility, supports tumor growth under high-density conditions, and maintains YAP-dependent transcription that overrides contact-dependent growth inhibition. What You Need to Know BackgroundProhaptoglobin, a precursor of haptoglobin, is elevated in pancreatic cancer, but its tumor-derived origin and functional role are unknown. We examined whether prohaptoglobin drives progression by sustaining YAP signaling. ImpactWe show that tumor-derived prohaptoglobin sustains nuclear YAP activity, allowing pancreatic cancer cells to bypass contact inhibition and proliferate, revealing prohaptoglobin as a context-dependent driver rather than a passive biomarker. Future DirectionsDefining how prohaptoglobin engages upstream Hippo-YAP regulators and whether prohaptoglobin-YAP signaling is targetable in vivo may uncover new biomarkers and therapeutic vulnerabilities for pancreatic cancer.

cancer biology↗

Enterococcus faecalis is involved in the progression of the early stages of latent chronic pancreatitis surrounding pancreatic cancer tissue

(Objective) In our previous research, we identified latent chronic pancreatitis in the normal tissue surrounding pancreatic cancer. We also discovered the presence of Enterococcus faecalis (E. faecalis), a type of intestinal bacterium, in the pancreatic fluid and tissue of pancreatic cancer patients, suggesting it may be one of the factors contributing to the development of latent chronic pancreatitis. In this study, we performed pathological analyses to investigate its characteristics and investigate a possibility of E. faecalis infection. (Methods) Pathological analyses were performed, using 16 cases of pancreatic cancer and intraductal papillary mucinous neoplasia (IPMN) involving lesions in the pancreas tail. The involvement of E. faecalis was investigated with immunohistochemical analysis and serological methods. (Results) All cases exhibited inflammatory changes in pancreatic tissue without a clinical diagnosis of chronic pancreatitis, along with macrophage infiltration. These changes did not significantly differ according to preoperative treatment. DNA encoding E. faecalis 16s ribosomal RNA was detected in many cases, however, a positive immunostaining to E. faecalis was observed in only a few cases. Serum capsular polysaccharide (CPS) antibody levels exceeding the mean values were observed in patients with established chronic pancreatitis, while the level was not correlated with E. faecalis immunostaining. (Conclusion) These results suggest the E. faecalis infection is involved in the early stage of the progression of chronic latent pancreatitis and the diagnostic technology incorporating novel multi-biomarkers may be useful for identifying high-risk individuals for future pancreatic cancer development.

cancer biology↗

Upregulation of Calbindin in Adult Inhibitory Neurons Reactivates Critical Period Plasticity in Mouse Visual Cortex

Critical periods are windows of peak learning performance where heightened synaptic plasticity enables fast, robust reorganization in juvenile brain circuits. Unlike adult plasticity which requires ongoing, persistent change in sensory experience, cortical representations can be rapidly changed during critical periods and have enduring effects. Transplantation of GABAergic inhibitory neurons has been shown to restore critical period plasticity to recipient circuits by triggering signalling changes within host inhibitory neurons. Here we transcriptionally profiled host inhibitory neurons in mouse primary visual cortex (V1) to detect gene expression changes during transplant-induced plasticity. Gene ontology enrichment analysis of differentially-expressed (DE) transcripts in host inhibitory neurons revealed synaptic plasticity- and inhibitory neuron development-related profiles. We assessed the protein expression of a top DE candidate, the calcium-binding protein Calbindin (Calb1), across transplant conditions and developmental stages. We found high Calb1 expression during the V1 critical period and during transplant-induced plasticity. To assess the functional significance of transplant-reactivated DE gene activity on visual cortical plasticity, we developed a set of AAVs to manipulate Calb1 expression specifically within inhibitory neurons. Using intrinsic signal imaging to measure ocular dominance plasticity, we found that Calb1 levels in V1 inhibitory neurons determine the extent of visual cortical plasticity. Our study provides evidence that direct induction of critical period-stage gene expression patterns in inhibitory neurons restores juvenile plasticity in targeted adult cortical circuits.

neuroscience↗

FUT8 mediated core fucosylation modulates growth related functions of LRP1 in liver cancer cells

Fucosylation is a cancer-associated glycosylation change, and core fucosylation of N-glycans catalyzed by the 1,6-fucosyltransferase FUT8, has been closely linked to tumor progression, metastasis, drug resistance, and poor prognosis. However, the core-fucosylated proteins that directly support hepatocarcinogenesis are not fully defined. In a KRAS-G12D-driven mouse liver cancer model, we observed increased fucosylation and FUT8 upregulation, and glycoproteomic analysis of fucose-enriched fractions identified low-density lipoprotein receptor-related protein 1 (LRP1) as a prominent core-fucosylated protein in tumor tissue. In immortalized mouse hepatocytes, genetic or pharmacological inhibition of FUT8 markedly increased Lrp1 mRNA and protein, indicating that loss of core fucosylation is accompanied by robust upregulation of LRP1. In human HepG2 cells, LRP1 knockout suppressed cell proliferation and markedly altered colony morphology, leading to compact rounded clusters instead of the typical polygonal pattern. It also reduced EGFR protein and further inhibited proliferation of HepG2 cell. These findings identify LRP1 as a FUT8-dependent core-fucosylated receptor in experimental hepatocarcinogenesis and suggest that the FUT8-LRP1 axis contributes to the maintenance of proliferative signaling in hepatoma cells.

cancer biology↗

Functional Impact of Glycosylation and Splicing Variants of LRIG1 on EGFR Proteostasis in Cancer

LRIG1, a membrane glycoprotein, has emerged as a significant stem cell marker and negative regulator of receptor tyrosine kinases (RTKs), including EGFR. Glycosylation is a major post-translational modification, which plays a crucial role in protein function and stability. In cancer biology, abnormal glycosylation can serve as a biomarker and contribute to pathogenesis. We aimed to investigate the effects of glycosylation on LRIG1 functions. Through database analysis and experimental approaches, we focused on evolutionarily conserved glycosylation sites of LRIG1, particularly N74 in humans. We found that a mutation of the N74 glycosylation site (N74Q) enhances LRIG1s binding to EGFR and promotes EGFR degradation. Furthermore, we identified a naturally occurring splice variant of LRIG1 lacking exon 2, which includes the N74 site, that shows similar enhanced EGFR binding and degradation. Analysis of TCGA data revealed that exon 2 skipping in LRIG1 occurs in various cancers, with higher levels correlating with poorer survival in breast and ovarian cancers. Our findings suggest that the absence of glycosylation at N74 enhances LRIG1-EGFR binding, providing an example of glycosylation negatively regulating protein-protein interaction. This mechanism, achieved through alternative splicing, provides insights into the importance of glycosylation deficiency in cancer biology.

biochemistry↗

Single-nucleus multi-omics identifies shared and distinct pathways in Pick's and Alzheimer's disease

The study of transcriptomic and epigenomic variations in neurodegenerative diseases, particularly tauopathies like Picks disease (PiD) and Alzheimers disease (AD), offers insights into their underlying regulatory mechanisms. Here, we identified critical regulatory changes driving disease progression, revealing potential therapeutic targets. Our comparative analyses uncovered disease-enriched non-coding regions and genome-wide transcription factor (TF) binding differences, linking them to target genes. Notably, we identified a distal human-gained enhancer (HGE) associated with E3 ubiquitin ligase (UBE3A), highlighting disease-specific regulatory alterations. Additionally, fine-mapping of AD risk genes uncovered loci enriched in microglial enhancers and accessible in other cell-types. Shared and distinct TF binding patterns were observed in neurons and glial cells across PiD and AD. We validated our findings using CRISPR to excise a predicted enhancer region in UBE3A and developed an interactive database, scROAD, to visualize predicted single-cell TF occupancy and regulatory networks. TeaserComparative studies in AD and PiD reveal critical regulatory changes and identify risk gene associations for PiD.

neuroscience↗

Spatial and single-nucleus transcriptomic analysis of genetic and sporadic forms of Alzheimer's Disease

The pathogenesis of Alzheimers disease (AD) depends on environmental and heritable factors, with remarkable differences evident between individuals at the molecular level. Here we present a transcriptomic survey of AD using spatial transcriptomics (ST) and single-nucleus RNA-seq in cortical samples from early-stage AD, late-stage AD, and AD in Down Syndrome (AD in DS) donors. Studying AD in DS provides an opportunity to enhance our understanding of the AD transcriptome, potentially bridging the gap between genetic mouse models and sporadic AD. Our analysis revealed spatial and cell-type specific changes in disease, with broad similarities in these changes between sAD and AD in DS. We performed additional ST experiments in a disease timecourse of 5xFAD and wildtype mice to facilitate cross-species comparisons. Finally, amyloid plaque and fibril imaging in the same tissue samples used for ST enabled us to directly link changes in gene expression with accumulation and spread of pathology.

neuroscience↗

Metabolic clogging of mannose triggers genomic instability via dNTP loss in human cancer cells

Mannose has anti-cancer activity that inhibits cell proliferation and enhances the efficacy of chemotherapy. How mannose exerts its anti-cancer activity, however, remains poorly understood. Here, using genetically engineered human cancer cells that permit the precise control of mannose metabolic flux, we demonstrate that the large influx of mannose exceeding its metabolic capacity induced metabolic remodeling, leading to the generation of slow-cycling cells with limited deoxyribonucleoside triphosphates (dNTPs). This metabolic remodeling impaired dormant origin firing required to rescue stalled forks by cisplatin, thus exacerbating replication stress. Importantly, pharmacological inhibition of de novo dNTP biosynthesis was sufficient to retard cell cycle progression, sensitize cells to cisplatin, and inhibit dormant origin firing, suggesting dNTP loss-induced genomic instability as a central mechanism for the anti-cancer activity of mannose.

cancer biology↗

High dimensional co-expression networks enable discovery of transcriptomic drivers in complex biological systems

Biological systems are immensely complex, organized into a multi-scale hierarchy of functional units based on tightly-regulated interactions between distinct molecules, cells, organs, and organisms. While experimental methods enable transcriptome-wide measurements across millions of cells, the most ubiquitous bioinformatic tools do not support systems-level analysis. Here we present hdWGCNA, a comprehensive framework for analyzing co-expression networks in high dimensional transcriptomics data such as single-cell and spatial RNA-seq. hdWGCNA provides built-in functions for network inference, gene module identification, functional gene enrichment analysis, statistical tests for network reproducibility, and data visualization. In addition to conventional single-cell RNA-seq, hdWGCNA is capable of performing isoform-level network analysis using long-read single-cell data. We showcase hdWGCNA using publicly available single-cell datasets from Autism spectrum disorder and Alzheimers disease brain samples, identifying disease-relevant co-expression network modules in specific cell populations. hdWGCNA is directly compatible with Seurat, a widely-used R package for single-cell and spatial transcriptomics analysis, and we demonstrate the scalability of hdWGCNA by analyzing a dataset containing nearly one million cells.

bioinformatics↗

Hepatocyte Differentiation From Mouse Liver Ductal Organoids By Transducing Four Liver-Specific Transcription Factors

Background & AimsHepatocyte sources that are expandable in vitro are required for liver regenerative medicine and to elucidate the mechanisms underlying the physiological functions of the liver. Liver ductal organoids (LDOs) comprise liver tissue stem cells with a bipotential capacity to differentiate into hepatocyte and cholangiocyte lineages, and can thus serve as a hepatocyte source. However, using current differentiation methods LDOs differentiate into immature hepatocytes while retaining strong cholangiocyte characteristics. We thus investigated an alternative differentiation method for LDOs to achieve hepatocyte maturation. MethodsWe extracted 12 candidate transcription factors to induce hepatocyte differentiation by comparing their gene expression in LDOs and liver tissues. After evaluating the effects of these transcription factors on LDOs, we analyzed the comprehensive gene expression profile, protein expression, and hepatic function in the transduced organoids. ResultsWe identified a combination of four transcription factors, Hnf4a, Foxa1, Prox1, and Hlf, which upregulated hepatic lineage markers and downregulated cholangiocyte markers. Differentiation-induced LDOs showed more hepatocyte-specific characteristics than those with the conventional method, enhancing the transition from cholangiocyte to hepatocyte lineage and hepatic functions, such as liver-specific protein synthesis, lipid droplet deposition, and ammonia detoxification. ConclusionTransduction of the four transcription factors (Hnf4a, Foxa1, Prox1, Hlf) is a promising strategy to promote the differentiation of LDOs to obtain mature hepatocyte-like cells with better functionality.

cell biology↗

Integrated transcriptome analysis of Huntingtons disease iPSC-derived and mouse astrocytes implicates dysregulated synaptogenesis, actin, and astrocyte maturation

Huntingtons disease (HD) is a neurodegenerative disease caused by an expanded CAG repeat within the Huntingtin (HTT) gene having dysregulated cellular homeostasis in the central nervous system, particularly in the striatum and cortex. Astrocytes establish and maintain neuronal functions through the secretion of soluble factors and physical interactions with other neurovascular unit cell types. Under pathological conditions, astrocytes can become reactive, causing cell state transitions that affect brain function. To investigate transitions between cellular states in unaffected and HD astrocytes at high resolution, single-nuclei RNA-sequencing (snRNA-seq) was performed on human HD patient induced pluripotent stem cell (iPSC)-derived astrocytes and on striatal and cortical tissue from a rapidly progressing HD mouse model (R6/2). Analysis of HD human and mouse astrocytes revealed both models have alterations in morphology, glutamate uptake, and dysregulation of astrocyte identity and maturation, whereas dysregulated actin-mediated signaling was unique to human iPSC-derived astrocytes. Representative proteins showed altered levels by Western. In both species, HD transcriptional changes reveal potential astrocyte maturation deficits that were potentially driven by astrogliogenesis transcription factors, including ATF3 and NFIA. When perturbed in a drosophila model of HD, knockdown of NFIA in glia rescued the climbing deficit. These data further support the hypothesis that mutant HTT induces dysregulated astrocyte cell states resulting in dysfunctional astrocytic properties, suggests that some of these states are cell autonomous and maybe unique to human HD, and implicate ATF3 and maturation deficits in HD pathogenesis.

neuroscience↗

Single nuclei RNAseq analysis of HD mouse models and human brain reveals impaired oligodendrocyte maturation and potential role for thiamine metabolism

The complexity of affected brain regions and cell types is a challenge for Huntingtons disease (HD) treatment. Here we used single nucleus RNA sequencing (snRNAseq) to investigate mechanism of pathology in the cortex and striatum from R6/2 mice at 8 and 12w and in three regions of human HD post-mortem tissue. We identified cell type-specific and cell agnostic signatures and found changes suggesting oligodendrocytes (OLs) and oligodendrocyte precursors (OPCs) were arrested in intermediate maturation states. OL-lineage regulators OLIG1 and OLIG2 were negatively correlated with CAG length in human OPCs, and ATACseq analysis of HD mouse NeuN-negative cells showed decreased accessibility of sites regulated by OL maturation genes. Glucose and lipid metabolism were implicated in abnormal cell maturation and PRKCE and Thiamine Pyrophosphokinase 1 were identified as central genes. High dose thiamine/biotin treatment of R6/1 HD mice to target thiamine metabolism not only restored OL maturation, but also rescued pathology in neurons. These findings reveal insights into HD OL pathology that spans multiple brain regions and link OL maturation deficits to abnormal thiamine metabolism.

neuroscience↗

Enterococcus spp. have higher fitness for survival, in a pH-dependent manner, in pancreatic juice among duodenal bacterial flora

ObjectivesBacterial infection is involved in the progression of many gastrointestinal diseases, including cancer; however, how and which bacteria colonize in pancreatic juice and tissue have yet to be elucidated. Recently, we reported that Enterococcus faecalis exists in the pancreatic juice and tissues of patients with chronic pancreatic disease. Here, we investigated the survival of E. faecalis in duodenal juice with different pH conditions. MethodsPancreatic juice samples from 62 patients with cancers of the duodeno-pancreato-biliary region were evaluated for the presence of E. faecalis. 16S ribosomal RNA PCR and 16S-based metagenome analyses were performed to determine the bacterial composition. The survival of E. faecalis in various pancreatic juice conditions was evaluated. ResultsOf 62 samples, 27% (17/62) were positive for Enterococcus spp., among which 71% (12/17) contained E. faecalis. Enterococcus spp. showed the highest fitness for survival in alkaline pancreatic juice among various bacterial species. The microbiome of pancreatic juice from patients with pancreatic and bile duct cancer showed diversity, but Enterococcus spp. were enriched among duodenal tumors and intraductal papillary mucinous neoplasms. ConclusionsAlkalinity is important for the selective survival of E. faecalis among microbiota. E. faecalis may induce pancreatic inflammation with changes in pancreatic juice conditions.

microbiology↗

The scaffold-dependent function of RIPK1 in dendritic cells promotes injury-induced colitis

Receptor interacting protein kinase 1 (RIPK1) is a cytosolic multidomain protein that controls cell life and death. While RIPK1 promotes cell death through its kinase activity, it also functions as a scaffold protein to promote cell survival by inhibiting FADD-caspase 8-dependent apoptosis and RIPK3-MLKL-dependent necroptosis. This pro-survival function is highlighted by excess cell death and a perinatal lethality in Ripk1-/- mice. Recently, loss of function mutation of RIPK1 was found in patients with immunodeficiency and inflammatory bowel diseases. Hematopoietic stem cell transplantation restored not only immunodeficiency but also intestinal inflammatory pathology, indicating that RIPK1 in hematopoietic cells is critical to maintain intestinal immune homeostasis. Here, we generated dendritic cell (DC)-specific Ripk1-/- mice in a genetic background with loss of RIPK1 kinase activity and found that the mice developed spontaneous colonic inflammation characterized by increased neutrophil infiltration. In addition, these mice were highly resistant to injury-induced colitis. The increased neutrophil infiltration in the colon and the resistance to colitis were restored by dual inactivation of RIPK3 and FADD, but not by inhibition of RIPK3, MLKL, or ZBP1 alone. Altogether, these results reveal a scaffold activity-dependent role of RIPK1 in protecting colonic DCs from apoptotic insults and maintenance of colonic immune homeostasis.

immunology↗

Integrative genomics approach identifies conserved transcriptomic networks in Alzheimer’s disease

Alzheimers disease (AD) is a devastating neurological disorder characterized by changes in cell-type proportions and consequently marked alterations of the transcriptome. Here we use a data-driven systems biology approach across multiple cohorts of human AD, encompassing different brain regions, and integrate with multi-scale datasets comprising of DNA methylation, histone acetylation, transcriptome- and genome-wide association studies as well as quantitative trait loci to define the genetic architecture of AD. We perform co-expression network analysis across more than twelve hundred human brain samples, identifying robust AD-associated dysregulation of the transcriptome, unaltered in normal human aging. We further integrate co-expression modules with single-cell transcriptome generated from 27,321 nuclei from postmortem human brain to identify AD-specific transcriptional changes and assess cell-type proportion changes in the human AD brain. We also show that genetic variants of AD are enriched in a glial AD-associated module and identify key transcription factors regulating co-expressed modules. Additionally, we validate our results in multiple published human AD datasets which are easily accessible using our online resource (https://swaruplab.bio.uci.edu/consensusAD).

neuroscience↗