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Biology subjects

Fu, F.

Publications and source records attributed to Fu, F..

11 recordsLinked to original sources

Genetic legacy in soil seedbanks after grassland conversion to plantation forests: evidence from Potentilla freyniana

Semi-natural grasslands are important ecosystems supporting biodiversity in Japan, but their area has declined rapidly due to land-use change and abandonment of traditional management practices such as mowing and burning. Although the conservation of genetic diversity is essential for the long-term persistence of grassland plants, little is known about the genetic diversity retained in soil seedbanks following conversion of grasslands to plantation forests. In this study, we compared the genetic diversity and population structure of above-ground and soil seedbank populations of the grassland perennial forb Potentilla freyniana across three sites in each of three land-use types: burned grasslands, deciduous plantation forests, and evergreen plantation forests (plantation ages approximately 21-62 years) on the Kaida Plateau, central Japan. Soil seedbank populations were obtained from soil samples through germination experiments, and genetic analyses were conducted using newly developed simple sequence repeat (SSR) markers. Genetic diversity was assessed using expected heterozygosity, allelic richness, and private allelic richness, population structure was evaluated using analysis of molecular variance (AMOVA), STRUCTURE analyses, and pairwise FST. Soil seedbank populations maintained levels of genetic diversity comparable to those of above-ground populations, and no significant differences were detected between the two population types. Furthermore, soil seedbank populations in evergreen plantation forests, where above-ground individuals of P. freyniana were absent, retained genetic diversity comparable to that observed in burned grasslands. AMOVA detected no significant genetic differentiation between above-ground and soil seedbank populations. These results suggest that high levels of genetic diversity can persist in soil seedbank populations for decades after forest establishment and highlight the potential importance of soil seedbanks as genetic resources for grassland restoration.

ecology↗

Serine Stabilizes SLC7A11 and Enhances Cystine Influx to Protect Against Acute Pancreatitis

Lethal sterile inflammatory diseases are linked to amino acid metabolism, but the role of serine remains unclear. Here, we show that dysregulated serine metabolism and reduced plasma serine levels correlate with disease severity of acute pancreatitis (AP) in patients and mouse models. Elevating serine levels via exogenous serine supplementation or pancreatic phosphoglycerate dehydrogenase (PHGDH) overexpression mitigates pancreatic injury, whereas a serine deprivation diet or pancreatic PHGDH knockdown exacerbates AP. Serine prevents cell death and oxidative stress in pancreatic acinar cells, human induced pluripotent stem cells-derived pancreatic organoids and mouse pancreatic tissue. Serine enhances cysteine and glutathione biosynthesis primarily by promoting solute carrier family 7 member 11 (SLC7A11)-dependent cystine uptake rather than by serving as a direct substrate. Mechanistically, the E3 ubiquitin ligase NEDD4 mediates ubiquitination and degradation of SLC7A11, whereas serine binds to NEDD4 and thereby inhibits SLC7A11 degradation. Similarly to serine, pharmacological inhibition of NEDD4 alleviates lipid peroxidation and pancreatic injury. These findings identify serine as a critical signaling regulator of SLC7A11 stability and oxidative stress, and provides a new therapeutic strategy for AP and associated sterile inflammatory disorders. HighlightsAcute pancreatitis (AP) is linked to abnormal serine metabolism and serine depletion. Serine prevents cell death in AP acinar cells, human pancreatic organoids and mice. Serine promotes SLC7A11-dependent cystine uptake and glutathione levels in acinar cells. Serine reduces NEDD4-mediated ubiquitination of SLC7A11. In briefSerine protects against cell death and pancreatic injury in acute pancreatitis by stabilizing SLC7A11 through disruption of NEDD4-mediated ubiquitination in acinar cells.

pharmacology and toxicology↗

Visual Analysis of Cell Death in Bladder Cancer -- A Bibliometrics-Based Comprehensive Study

Cell death mechanisms offer therapeutic strategies for bladder cancer, yet lack comprehensive bibliometric analysis. Map global research trends and hotspots in bladder cancer cell death mechanisms via bibliometrics. We analyzed 5,392 publications (1991-2024) from Web of Science using VOSviewer (co- authorship/keyword clustering), CiteSpace (citation bursts), and GraphPad Prism (statistics). Metrics included: (1) Temporal trends, (2) Country/institution contributions, (3) Journal impact, (4) Citation dynamics, (5) Collaboration networks, (6) Conceptual hotspots. China and the US led research output. Top institutions:University of Texas System (USA; 178 publications), UTMD Anderson Cancer Center (USA; 123), Nanjing Medical University (China; 122), Journal of Urology had the highest output (106 publications); Cancer Research (IF:12.5) the highest impact. Kim Wun-Jae was the most productive author (37 articles); Jemal A the most co-cited (446 citations). Keyword and citation analyses revealed emerging integration of cell death mechanisms with immunotherapy (IT) and photodynamic therapy (PDT) to overcome chemoresistance. This study delineates the evolution of bladder cancer cell death research and identifies IT/PDT as promising resistance-overcoming strategies grounded in targeted cell death pathways.

cancer biology↗

Spatiotemporal regulation of ciliary outer dynein arm biogenesis and the role of PIH homologs

Outer Dynein Arm complex (ODA) powers motile cilia that are indispensable for fundamental processes, including embryogenesis, reproduction, and respiration. The ODA subunits: heavy (HC), intermediate (IC), and light chains (LC), are known to preassemble in the cytoplasm with the help of Dynein Axonemal Assembly Factors (DNAAFs). The mechanistic details underlying functional ODA assembly and the specific roles of DNAAFs in orchestrating subunit translation, folding, and assembly are still poorly defined. Using Trypanosoma brucei as a model, we showed that ODA preassembly is coupled to HC translation, during which ICs post-translationally associate with translating HCs to form co-translational assembly sites. PIH1D1, a DNAAF and a PIH family protein, concentrates at these cotranslational assembly sites. Without PIH1D1, HC protein levels are reduced, leaving the IC-LC complex stranded in the cytoplasm. We propose that PIH1D1 generates specialised compartments to assist the co-translational folding of HCs and enable their assembly with the other ODA subunits. Our study highlights spatial compartmentalization as a conserved strategy that interweaves translation, folding, and assembly to ensure ordered and timely ODA formation during ciliogenesis.

cell biology↗

Intratumoral Resident Microbes Directly Participate in Resistance to EGFR-TKI Targeted Drug Therapy through Metabolism in NSCLC

EGFR-TKIs targeted therapy represents a cornerstone in the treatment of non-small cell lung cancer (NSCLC). Nonetheless, a subset of patients inevitably develops acquired resistance to EGFR-TKIs, posing a significant clinical challenge. An increasing number of evidence has documented the presence of microbial communities within tumor microenvironments, but the potential interplay between tumor-resident microbiota and resistance to EGFR-TKIs remains poorly understood. Here, we report that prolonged EGFR-TKIs treatment markedly alters the diversity of tumor-resident microbiota, characterized by a notable enrichment of Bacillus mycoides and Pseudomonas veronii. In vitro experiments revealed that co-culture of gefitinib with either B. mycoides or P. veronii significantly attenuated its tumor-suppressive efficacy, both in vitro and in vivo. Mechanistically, gefitinib underwent extensive biotransformation in the presence of these bacteria, yielding redox derivatives and conjugation products, which collectively diminished its antitumor activity. Specifically, B. mycoides metabolized gefitinib into B.mPM9-C33 H45 Cl F N3 O4, while P. veronii generated P.vPM2-C24 H29 Cl N4 O3, both of which were consistently detected in in vivo and in vitro models. Furthermore, heterologous expression of maltose acetyltransferase from B. mycoides in E. coli BL21 conferred the capacity to metabolize gefitinib, underscoring the enzymatic basis of this metabolic conversion. Collectively, these findings demonstrate that B. mycoides and P. veronii drive tumor resistance to EGFR-TKIs through metabolic inactivation of the drug, unveiling a previously unrecognized role of tumor-resident microbiota in modulating therapeutic responses and providing novel insights into the mechanisms underlying EGFR-TKIs resistance in NSCLC.

microbiology↗

Super-resolution vibrational imaging using expansion stimulated Raman scattering microscopy

Stimulated Raman scattering (SRS) microscopy is an emerging technology that provides high chemical specificity for endogenous biomolecules and can circumvent common constraints of fluorescence microscopy including limited capabilities to probe small biomolecules and difficulty resolving many colors simultaneously due to spectral overlap. However, the resolution of SRS microscopy remains governed by the diffraction limit. To overcome this, we describe a new technique called Molecule Anchorable Gel-enabled Nanoscale Imaging of Fluorescence and stImulatEd Raman Scattering microscopy (MAGNIFIERS), that integrates SRS microscopy with expansion microscopy (ExM). ExM is a powerful strategy providing significant improvement in imaging resolution by physical magnification of hydrogel-embedded preserved biological specimens. MAGNIFIERS offers chemical-specific nanoscale imaging with sub-50 nm resolution and has scalable multiplexity when combined with multiplex Raman probes and fluorescent labels. We used MAGNIFIERS to visualize nanoscale features in a label-free manner with C-H vibration of proteins, lipids and DNA in a broad range of biological specimens, from mouse brain, liver and kidney to human lung organoid. In addition, we applied MAGNIFIERS to track nanoscale features of protein synthesis in protein aggregates using metabolic labeling of small metabolites. Finally, we used MAGNIFIERS to demonstrate 8-color nanoscale imaging in an expanded mouse brain section. Overall, MAGNIFIERS is a valuable platform for super-resolution label-free chemical imaging, high-resolution metabolic imaging, and highly multiplexed nanoscale imaging, thus bringing SRS to nanoscopy.

bioengineering↗

Wound-like tumor periphery in human breast cancer predicts a convergent drug nonresponse

A significant portion of breast cancer patients are nonresponsive to well-established drugs and destined for a poor outcome regardless of molecular subtype. Although several (multiparameter) molecular markers have predicted their resistance to some of these drugs, profound uniparameter markers predictive of a convergent nonresponse to all these drugs remain elusive. We employ co-registered standard-multiphoton histology to representatively sample a few peripheral niches of the primary tumor, so that hundreds of patients can be stratified with either a wound-like or non-wound tumor periphery. With no fitting variable, this simple uniparameter morphological marker is: (a) highly sensitive and specific to predict a multidrug-nonresponsive phenotype that accounts for the majority of recurrence or death, independent of the molecular subtype or related adjuvant drug selection, clinical endpoint (disease-free versus overall survival), and hosting medical center; (b) robust against intratumor heterogeneity and valid at the earliest clinicopathological stage; and (c) dominant in predicting prognosis in the context of routine clinicopathological markers. Considering the mechanistic link between a wound-like extracellular matrix and a microenvironment supporting migratory or mesenchymal tumor cells, we attribute these unusual capabilities to an epithelial-mesenchymal transition nature of the morphological marker long sought after by pathologists.

pathology↗

Lack of authentic atrial fibrillation in commonly used murine atrial fibrillation models

The mouse is a useful preclinical species for evaluating disease etiology due to the availability of a wide variety of genetically modified strains and the ability to perform disease-modifying manipulations. In order to better characterize atrial fibrillation (AF), we profiled several commonly used murine AF models. We initially evaluated a pharmacological model of acute carbachol (CCh) treatment plus atrial burst pacing in C57BL/6 mice. In an effort to observe micro-reentrant circuits indicative of authentic AF, we employed optical mapping imaging in isolated mouse hearts. While CCh reduced atrial refractoriness and increased atrial tachyarrhythmia vulnerability, the left atrial (LA) excitation patterns were rather regular without reentrant circuits or wavelets. Therefore, the atrial tachyarrhythmia resembled high frequency atrial flutter, not typical AF per se. We next examined both a chronic angiotensin II (Ang II) infusion model and the surgical model of transverse aortic constriction (TAC), which have both been reported to induce atrial and ventricular structural changes that serve as a substrates for micro-reentrant AF. Although we observed some extent of atrial remodeling such as fibrosis or enlarged LA diameter, burst pacing-induced atrial tachyarrhythmia vulnerability did not differ from control mice in either model. This again suggested that an AF-like pathophysiology is difficult to demonstrate in the mouse. To continue searching for a valid murine AF model, we studied mice with a cardiac-specific deficiency (KO) in liver kinase B1 (Cardiac-LKB1), which has been reported to exhibit spontaneous AF. Indeed, the electrocardiograms (ECG) of conscious Cardiac-LKB1 KO mice exhibited no P waves and had irregular RR intervals, which are characteristics of AF. Histological evaluation of Cardiac-LKB1 KO mice revealed dilated and fibrotic atria, again consistent with AF. However, atrial electrograms and optical mapping revealed that electrical activity was limited to the sino-atrial node area with no electrical conduction into the atrial myocardium beyond. Thus, Cardiac-LKB KO mice have severe atrial myopathy or atrial standstill, but not AF. In summary, the atrial tachyarrhythmias we observed in the four murine models were distinct from typical human AF, which often exhibits micro- or macro-reentrant atrial circuits. Our results suggest that the four murine AF models we examined are poor representations of human AF, and raise a cautionary note about the use of any murine model to study AF.

physiology↗

Quantitative Visualization of Hypoxia and Proliferation Gradients Within Histological Tissue Sections

The formation of hypoxic microenvironments within solid tumors is known to contribute to radiation resistance, chemotherapy resistance, immune suppression, increased metastasis, and an overall poor prognosis. It is therefore crucial to understand the spatial and molecular mechanisms that contribute to tumor hypoxia formation to improve the efficacy of radiation treatment, develop hypoxia-directed therapies, and increase patient survival. The objective of this study is to present a number of complementary novel methods for quantifying tumor hypoxia and proliferation, especially in relation to the location of perfused blood vessels.\n\nMultiplexed immunofluorescence staining can produce whole slide scanned image datasets that are amenable for computational pathology analysis. A standard marker analysis strategy is to take a positive pixel count approach, in which a threshold for positive stain is used to compute a positive area fraction for hypoxia. This work is a reassessment of that approach, utilizing not only cell segmentation but also distance to nearest blood vessel in order to incorporate spatial information into the analysis. We describe a reproducible pipeline for the visualization and quantitative analysis of hypoxia using a vessel distance analysis approach. This methodological pipeline can serve to further elucidate the relationship between vessel distance and microenvironment-linked markers such as hypoxia and proliferation, can help to quantify parameters relating to oxygen consumption and hypoxic tolerance in tissues, as well as potentially serve as a hypothesis generating tool for future studies testing hypoxia-linked markers.

bioinformatics↗

Multiplexed imaging of immune cells in staged multiple sclerosis lesions by mass cytometry

Multiple Sclerosis (MS) is characterized by demyelinated and inflammatory lesions in the brain and spinal cord. Lesions contain immune cells with variable phenotypes and functions. Here we use imaging mass cytometry (IMC) to enable the simultaneous imaging of 15+ proteins within 11 staged MS lesions. Using this approach, we demonstrated that the majority of demyelinating macrophage-like cells in active lesions were derived from the resident microglial pool. Although CD8+ T cells predominantly infiltrated the lesions, CD4+ T cells were also abundant but localized closer to blood vessels. B cells with a predominant switched memory phenotype were enriched across all lesion stages and were found to preferentially infiltrate the tissue as compared to unswitched B cells which localized to the vasculature. We propose that IMC will enable a comprehensive analysis of single-cell phenotypes, their functional states and cell-cell interactions in relation to lesion morphometry and demyelinating activity in the MS brain.

immunology↗

Cancer-Induced Immunosuppression can enable Effectiveness of Immunotherapy through Bistability Generation: a mathematical and computational Examination

Cancer immunotherapies rely on how interactions between cancer and immune system cells are constituted. The more essential to the emergence of the dynamical behavior of cancer growth these are, the more effectively they may be used as mechanisms for interventions. Mathematical modeling can help unearth such connections, and help explain how they shape the dynamics of cancer growth. Here, we explored whether there exist simple, consistent properties of cancer-immune system interaction (CISI) models that might be harnessed to devise effective immunotherapy approaches. We did this for a family of three related models of increasing complexity. To this end, we developed a base model of CISI, which captures some essential features of the more complex models built on it. We find that the base model and its derivates can plausibly reproduce biological behavior that is consistent with the notion of an immunological barrier. This behavior is also in accord with situations in which the suppressive effects exerted by cancer cells on immune cells dominate their proliferative effects. Under these circumstances, the model family may display a pattern of bistability, where two distinct, stable states (a cancer-free, and a full-grown cancer state) are possible. Increasing the effectiveness of immune-caused cancer cell killing may remove the basis for bistability, and abruptly tip the dynamics of the system into a cancer-free state. Additionally, in combination with the administration of immune effector cells, modifications in cancer cell killing may be harnessed for immunotherapy without the need for resolving the bistability. We use these ideas to test immunotherapeutic interventions in silico in a stochastic version of the base model. This bistability-reliant approach to cancer interventions might offer advantages over those that comprise gradual declines in cancer cell numbers.

cancer biology↗