Biology subjects

Han, J. W.

Publications and source records attributed to Han, J. W..

5 recordsLinked to original sources

bioRxiv2026

The mycotoxin zearalenone couples secondary metabolism to N-acetylglucosamine catabolism

Fungal secondary metabolites are often viewed as terminal products of specialized metabolism, yet how their production influences the physiology of the producing organism remains poorly understood. Here, we show that zearalenone (ZEA) production is functionally coupled to N-acetylglucosamine (GlcNAc) catabolism in Fusarium graminearum. Transcriptome profiling of a ZEB2-overexpressing strain revealed enrichment of GlcNAc metabolic functions, and exogenous ZEA induced key catabolic genes independently of Zeb2. Among pathway components, NAG, encoding GlcNAc-6-phosphate deacetylase, was critical for GlcNAc utilization, and its loss caused severe GlcNAc-dependent growth inhibition. Genetic impairment of NAG was poorly tolerated under elevated ZEA pathway activity. Conversely, NAG overexpression increased tolerance to exogenous ZEA and alleviated the growth defect associated with ZEB2 overexpression. Together, these findings reveal a functional connection between secondary metabolite production and primary nutrient metabolism and suggest that ZEA-associated metabolic remodeling contributes to the fitness of the producing fungus.

molecular biology↗

bioRxiv2026

Transcriptome dissection of the Zeb2-associated network reveals a role for NRPS15 in zearalenone biosynthesis in Fusarium graminearum

Fungal secondary metabolites, including mycotoxins, play important roles in fungal biology and represent major concerns for food and feed safety. Zearalenone (ZEA) is an estrogenic polyketide mycotoxin produced by several Fusarium species, yet the genetic network governing its production remains poorly characterized. Here, we investigated genes associated with ZEA production in Fusarium graminearum using two complementary transcriptomic approaches. Time-resolved transcriptome analysis revealed transcriptional changes preceding detectable ZEA accumulation. Temporal clustering further revealed coordinated changes in primary metabolism, transcriptional regulation, carbohydrate utilization, and stress- and transport-associated pathways during ZEA-inducing cultivation. Genotype-based transcriptome analysis of ZEB2 deletion and overexpression strains subsequently identified Zeb2-responsive genes. Functional screening identified NRPS15, encoding a previously uncharacterized nonribosomal peptide synthetase-like protein adjacent to the ZEA biosynthetic cluster, as an important contributor to ZEA production. Deletion of NRPS15 markedly reduced ZEA production and expression of PKS4, PKS13, ZEB1, and ZEB2. NRPS15 expression did not restore ZEA production in the absence of Zeb2. NRPS15 orthologs were conserved in several ZEA-producing Fusarium species, and deletion of NRPS15 substantially reduced ZEA production in Fusarium culmorum. These findings expand the functional genetic context of ZEA production beyond the canonical four-gene biosynthetic cluster.

molecular biology↗

bioRxiv2026

Chirality-Driven Photonic PCR Enables Label-Free Genetic Amplification

Photonic polymerase chain reaction (PCR) offers a rapid alternative to conventional thermal cycling for genetic amplification, but current platforms are limited by low photothermal conversion efficiencies and a dependence on bulky fluorescent monitoring systems. Here we report a chirality-driven photonic amplification paradigm that achieves both accelerated nucleic acid replication and direct, label-free detection. By leveraging chiral plasmonic nanoparticles, we exploit their elevated absorption cross-sections to achieve exceptional light-to-heat conversion and rapid thermal relaxation, significantly accelerating heating and cooling rates during cycling. We show that localized chiral near-fields generated by these chiral plasmonic nanoparticles optimize DNA polymerase conformational dynamics, lowering the activation energy barrier for synthesis and boosting amplification efficiency. Furthermore, by tracking the reaction with circular dichroism spectroscopy, we directly monitor the intrinsic chiroptical signature of amplifying DNA, completely eliminating the need for external fluorescent dyes or labeled probes. We validate this system using SARS-CoV-2 E-gene plasmid DNA templates, demonstrating rapid, label-free amplification and single-copy detection within clinically relevant timelines. By bridging asymmetric photothermal dynamics with chiral-field-induced enzymatic activation, this work translates chiroplasmonic materials from fundamental physics into high-performance, point-of-care molecular diagnostics.

bioengineering↗

bioRxiv2026

Human iPSCs and iPSC-Derived Endothelial Cells from PAD Patients and Healthy Donors Exhibit Comparable Characteristics and Potency: Implications for Autologous Cell Therapy in Peripheral Artery Disease

BACKGROUND: Peripheral artery disease (PAD) can lead to amputation in advanced cases, making cell therapy using human induced pluripotent stem cells (hiPSCs) a promising therapeutic option. hiPSC-derived endothelial cells (hiPSC-ECs) have shown favorable effects in treating experimental ischemic cardiovascular disease. An autologous approach for PAD patients is preferable to avoid immunological reactions. However, it is yet unknown whether hiPSCs and hiPSC-ECs derived from PAD patients have similar characteristics and potency compared to those derived from non-PAD donors. Therefore, we explored whether there are significant differences in the characteristics and potency of hiPSCs and hiPSC-ECs between non-PAD donors and PAD patients. METHODS: We generated hiPSCs from the blood of non-PAD donors and patients with PAD. We determined the pluripotency of hiPSCs using qRT-PCR, flow cytometry, immunostaining, RNA-seq, and teratoma formation assay. The genetic stability of hiPSCs was confirmed by G-banding karyotyping. We then differentiated hiPSCs into endothelial cells (ECs) in a clinically compatible manner. We compared the characteristics and therapeutic potency of hiPSC-ECs derived from non-PAD and PAD groups using qRT-PCR, flow cytometry, immunostaining, and RNA-seq. In vitro endothelial functions were determined by nitric oxide (NO) production and capillary network formation. Therapeutic potency and incorporation of engrafted hiPSC-ECs were evaluated in a hindlimb ischemia model. RESULTS: We successfully generated hiPSCs from the blood of seven non-PAD donors and eight PAD patients. Both non-PAD and PAD-derived hiPSCs exhibited similar expression levels of pluripotency markers. All hiPSCs, regardless of the group, formed teratomas and showed normal karyotypes. RNA-seq analyses revealed similar gene expression profiles between the groups. hiPSC-ECs derived from both non-PAD and PAD donors exhibited similar expression levels of EC markers at both the gene and protein levels. RNA-seq analyses showed no significant overall differences in gene expression profiles between the groups. Functional analyses demonstrated similar endothelial characteristics and function in hiPSC-ECs from both groups. Both groups showed similar perfusion recovery, limb salvage, and vessel-forming capacity. Engrafted hiPSC-ECs from both groups also exhibited similar angiogenic and vessel-forming capabilities. CONCLUSIONS: Our study demonstrated no significant differences in hiPSCs and hiPSC-ECs derived from non-PAD donors and PAD patients in terms of molecular and cell biological characteristics, therapeutic effects, and vessel-forming capability. Our study indicates that hiPSCs and hiPSC-ECs derived from PAD patients can serve as a novel platform for autologous cell therapy.

cell biology↗

bioRxiv2025

TCR signaling via NFATc1 constrains IL-15-induced NK-like activation of human memory CD8+ T cells

Here we investigated the regulatory mechanisms of TCR-independent bystander activation and NK-like cytotoxicity of human memory CD8+ T cells. We found that TCR signals suppressed characteristic features of IL-15-induced CD8+ T-cell activation, including increased NKG2D expression and upregulation of genes related to NK cytotoxicity and IFN response. Moreover, ionomycin suppressed IL-15-induced bystander activation and NK-like cytotoxicity, indicating that Ca2+-calcineurin signaling is responsible for TCR-mediated suppression of IL-15-induced bystander activation. In detail, NFATc1 suppressed IL-15-induced bystander activation via binding to AP-1 that is necessary for the IL-15-induced upregulation of NK cytotoxicity-related genes. Consistent with these results, calcineurin inhibitors enhanced IL-15-induced NKG2D expression in the presence of TCR signals. Additionally, we defined genes upregulated by IL-15 and downregulated by concurrent TCR signals as an IL-15-induced bystander activation gene set, and found that this gene signature was upregulated in bystander CD8+ T cells from patients with hepatitis A virus infection. This study paves the way for further investigation of bystander CD8+ T-cell activation in various pathological conditions, and its regulation. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=191 HEIGHT=200 SRC="FIGDIR/small/632884v2_ufig1.gif" ALT="Figure 1"> View larger version (60K): org.highwire.dtl.DTLVardef@1e6c320org.highwire.dtl.DTLVardef@114a23eorg.highwire.dtl.DTLVardef@1a7b9edorg.highwire.dtl.DTLVardef@9faccc_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LITCR signaling downregulates IL-15-induced transcriptomic features related to NK-like bystander activation of human memory CD8+ T cells via the Ca2+-calcineurin pathway. C_LIO_LINFATc1 suppresses IL-15-induced bystander activation via binding to AP-1, which is responsible for IL-15-induced NK-like cytotoxic activity. C_LIO_LICalcineurin inhibitors cannot suppress IL-15-induced bystander CD8+ T-cell activation, and paradoxically increase IL-15-induced NKG2D expression in the presence of TCR signals. C_LIO_LIGenes upregulated by IL-15 and downregulated by concurrent TCR signals define the gene set of bystander CD8+ T-cell activation, which was validated in disease contexts. C_LI

immunology↗