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Biology subjects

Wu, C.-S.

Publications and source records attributed to Wu, C.-S..

9 recordsLinked to original sources

A latent hydrazone switch turns SP2509 into an optical timer of cell fate

Epigenetic inhibitors can reprogram cell states, but their activity is usually governed by fixed dose-response relationships rather than by user-defined temporal commands. Here we show that SP2509, an established reversible LSD1/KDM1A inhibitor, contains a latent ortho-hydroxy acylhydrazone switch that converts this known scaffold into an optical timer for chromatin-dependent cell fate. Irradiation at 430 nm enriches a less active cis-associated state under near-physiological conditions, whereas dark relaxation regenerates the more active trans-associated state with a half-life of 6.5 hours. This reversible conformational change reduces recombinant LSD1 inhibition by approximately 7-fold and is transmitted to H3K9me2 accumulation, proliferation, senescence and apoptosis. Reciprocal light-dark switching experiments reveal a reversible window for senescence-associated arrest in MGC-803 cells and tune population-level entry into apoptosis in OCI-AML3 cells. RNA-seq endpoint comparisons further distinguish photostate-associated transcriptional states, with dark trans-SP2509 producing stronger stress-survival and apoptosis-linked programs than cells maintained under cis-SP2509 conditions. These findings establish latent hydrazone photoisomerization as a compact strategy for converting a static epigenetic inhibitor into a kinetic regulator of chromatin-dependent cell-fate transitions.

biochemistry↗

NAD+ reduction in glutamatergic neurons triggers fatty acid catabolism and neuroinflammation in the brain, mitigated by SARM1 deletion

The importance of NAD+ homeostasis for neuronal health has been emphasized by studies on nicotinamide mononucleotide adenylyl transferase 2 (NMNAT2), a NAD+-synthesizing enzyme, and sterile alpha and TIR motif-containing protein 1 (SARM1), a NAD+ hydrolase. NMNAT2 declines caused by neurodegenerative insults activate SARM1 to degenerate axons. To elucidate the impact of the NMNAT2-SARM1 axis on brain energy metabolism, we employed multi-omics approaches to investigate the metabolic effects caused by neuronal NMNAT2 loss. The loss of NMNAT2 in glutamatergic neurons results in a striking metabolic shift in the cerebral cortex from glucose to lipid catabolism, reduced lipid abundance, and pronounced neurodegenerative phenotypes. Proteomic analysis found that neuronal NMNAT2 loss altered levels of glial enzymes central to glucose and lipid metabolism. Genetic deletion of SARM1 in NMNAT2-deficient mice restores lipid metabolism and mitigates neurodegeneration. Taken together, we show that neuronal NAD+ reduction leads to SARM1-dependent maladaptive adaptations in both neurons and glia.

neuroscience↗

Phylogenomic inference suggests differential deep time phylogenetic signals from nuclear and organellar genomes in gymnosperms

The living gymnosperms include about 1,100 species in five major groups: cycads, ginkgo, gnetophytes, Pinaceae (conifers I), and cuppressophytes (conifers II). Molecular phylogenetic studies have yet to reach a unanimously agreed relationship among them. Moreover, cytonuclear phylogenetic incongruence has been repeatedly observed in gymnosperms. We collated a comprehensive data set from available genomes and added our own high-quality assembly of a species from Podocarpaceae (the 2nd largest conifer family) to increase sampling width. We used these data to infer reconciled nuclear species phylogenies using two separate methods to ensure robustness of our conclusions. We also reconstructed organelle phylogenomic trees from 41 mitochondrial and 82 plastid genes. Our nuclear phylogeny consistently recovers the Ginkgo-cycads clade as the first lineage split from other gymnosperm clades and the Pinaceae as sister to gnetophytes (the Gnepines hypothesis). In contrast, the mitochondrial tree places cycads as the earliest lineage in gymnosperms and gnetophytes as sister to cupressophytes (the Gne-cup hypothesis) while the plastomic tree supports the Ginkgo-cycads clade and Gnetophytes as the sister to Cupressophytes. We also examined the effect of mitochondrial RNA editing sites on the gymnosperm phylogeny by manipulating the nucleotide and amino acid sequences at these sites. Only complete removal of editing sites has an effect on phylogenetic inference, leading to a closer congruence between mitogenomic and nuclear phylogenies. This suggests that RNA editing sites carry a phylogenetic signal with distinct evolutionary traits.

evolutionary biology↗

The natural tannins oligomeric proanthocyanidins and punicalagin are potent inhibitors of infection by SARS-CoV-2 in vitro

The COVID-19 pandemic continues to infect people worldwide. While the vaccinated population has been increasing, the rising breakthrough infection persists in the vaccinated population. For living with the virus, the dietary guidelines to prevent virus infection are worthy of and timely to develop further. Tannic acid has been demonstrated to be an effective inhibitor of coronavirus and is under clinical trial. Here we found that two other members of the tannins family, oligomeric proanthocyanidins (OPCs) and punicalagin, are also potent inhibitors against SARS-CoV-2 infection with different mechanisms. OPCs and punicalagin showed inhibitory activity against omicron variants of SARS-CoV-2 infection. The water extractant of the grape seed was rich in OPCs and also exhibited the strongest inhibitory activities for viral entry of wild-type and other variants in vitro. Moreover, we evaluated the inhibitory activity of grape seed extractants (GSE) supplementation against SARS-CoV-2 viral entry in vivo and observed that serum samples from the healthy human subjects had suppressive activity against different variants of SARS-CoV-2 vpp infection after taking GSE capsules. Our results suggest that natural tannins acted as potent inhibitors against SARS-CoV-2 infection, and GSE supplementation could serve as healthy food for infection prevention. HighlightsO_LIOPCs and Punicalagin had inhibitory activity against omicron variants of SARS-CoV-2 infection. C_LIO_LIOPCs serve as a dual inhibitor of the viral Mpro and the cellular TMPRSS2 protease. C_LIO_LIPunicalagin possesses the most potent activity to suppress the Mpro and block the interaction of the viral spike protein and human ACE2. C_LIO_LIOPCs-enriched grape seed extractant exhibited inhibitory activities for viral entry of wild-type and other variants of SARS-CoV-2. C_LIO_LIThe daily intake of grape seed extractants may be able to prevent SARS-CoV-2 infection. C_LI

microbiology↗

Auxin Plays a Role in the Adaptation of Rice to Anaerobic Germination and Seedling Establishment

Auxin is well known to stimulate coleoptile elongation and rapid seedling growth in the air. However, its role in regulating rice germination and seedling establishment under submergence is largely unknown. Previous studies have shown that excessive levels of IAA frequently cause the inhibition of plant growth and development. In the present study, the high-level accumulation of endogenous IAA is observed under submergence in the dark, stimulating rice coleoptile elongation but limiting the root and primary leaf growth during anaerobic germination (AG). We found that oxygen and light can reduce IAA levels, promote the seedling establishment and enhance rice AG tolerance. miRNA microarray profiling and RNA gel blot analysis results show that the expression of miR167 is negatively regulated by submergence; it subsequently modulates the accumulation of free IAA through the miR167-ARF-GH3 pathway. The OsGH3-8 encodes an IAA-amido synthetase that functions to prevent free IAA accumulation. Reduced miR167 levels or overexpressing OsGH3-8 increase auxin metabolism, reduce endogenous levels of free IAA and enhance rice AG tolerance. The present study reveals that poor seed germination and seedling growth inhibition resulting from excessive IAA accumulation would cause intolerance to submergence in rice, suggesting that a certain threshold level of auxin is essential for rice AG tolerance.

plant biology↗

RNA LEVER Mediates Long-Range Regulation of ε-globin by Keeping PRC2 in Check

Polycomb Repressive Complex 2 (PRC2) is an epigenetic regulator required for gene silencing during embryonic development. Previous studies have reported that PRC2 interacts with RNA in a promiscuous manner, but the biological functions of such interaction are unknown. Here we present a seesaw mechanism for the regulation of {varepsilon}-globin through inactivating EZH2 by an upstream non-coding RNA (LEVER). We show that LEVER, a non-coding RNA identified by RNA immunoprecipitation sequencing (RIP-seq) of the PRC2 core subunit EZH2 and Nanopore sequencing, binds PRC2 and thereby prevents the accumulation of H3K27 methylation along the genomic region where LEVER RNA is transcribed. The open chromatin within the LEVER locus in turn competes for the chromatin interaction between the {varepsilon}-globin promoter and the Locus Control Region (LCR), working as a negative regulatory element of {varepsilon}-globin expression. Hence, LEVER RNA negatively regulates {varepsilon}-globin by sequestering PRC2 from repressing the LEVER locus, which is a competitor of the {varepsilon}-globin-LCR interaction.

molecular biology↗

Myeloid lncRNA LOUP Mediates Opposing Regulatory Effects of RUNX1 and RUNX1-ETO in t(8;21) AML

The mechanism underlying cell type-specific gene induction conferred by ubiquitous transcription factors as well as disruptions caused by their chimeric derivatives in leukemia is not well understood. Here we investigate whether RNAs coordinate with transcription factors to drive myeloid gene transcription. In an integrated genome-wide approach surveying for gene loci exhibiting concurrent RNA- and DNA-interactions with the broadly expressed transcription factor RUNX1, we identified the long noncoding RNA LOUP. This myeloid-specific and polyadenylated lncRNA induces myeloid differentiation and inhibits cell growth, acting as a transcriptional inducer of the myeloid master regulator PU.1. Mechanistically, LOUP recruits RUNX1 to both the PU.1 enhancer and the promoter, leading to the formation of an active chromatin loop. In t(8;21) acute myeloid leukemia, wherein RUNX1 is fused to ETO, the resulting oncogenic fusion protein RUNX1-ETO limits chromatin accessibility at the LOUP locus, causing inhibition of LOUP and PU.1 expression. These findings highlight the important role of the interplay between cell type-specific RNAs and transcription factors as well as their oncogenic derivatives in modulating lineage-gene activation and raise the possibility that RNA regulators of transcription factors represent alternative targets for therapeutic development. KEY POINTSO_LIlncRNA LOUP coordinates with RUNX1 to induces PU.1 long-range transcription, conferring myeloid differentiation and inhibiting cell growth. C_LIO_LIRUNX1-ETO limits chromatin accessibility at the LOUP locus, causing inhibition of LOUP and PU.1 expression in t(8;21) AML. C_LI

cancer biology↗

Enlarged and highly repetitive plastome of Lagarostrobos and plastid phylogenomics of Podocarpaceae

Podocarpaceae is the largest family in cupressophytes (conifers II), but their plastid genomes (plastomes) are poorly studied, with plastome data currently existing for only four of the 19 Podocarpaceous genera. In this study, we assembled the plastomes from representatives of eight additional genera, including Afrocarpus, Dacrydium, Lagarostrobos, Lepidothamnus, Microstrobos, Phyllocladus, Prumnopitys, and Saxegothaea. We found that Lagarostrobos, a monotypic genus native to Tasmania, has the largest plastome among any cupressophytes studied to date (151,496 bp). Plastome enlargement in Lagarostrobos coincides with increased intergenic spacers, repeats, and duplicated genes. Among Podocarpaceae, Lagarostrobos has the most rearranged plastome, but its substitution rates are modest. Plastid phylogenomic analyses clarify the positions of previously conflicting Podocarpaceous genera. Tree topologies firmly support the division of Podocarpaceae into two sister clades: (1) the Prumnopityoid clade and (2) the clade containing Podocarpoid, Dacrydioid, Microstrobos, and Saxegothaea. The Phyllocladus is nested within the Podocarpaceae, thus familial status of the monotypic Phyllocladaceae is not supported.

evolutionary biology↗

Stout camphor tree genome fills gaps in understanding of flowering plant genome and gene family evolution

We present reference-quality genome assembly and annotation for the stout camphor tree (SCT; Cinnamomum kanehirae [Laurales, Lauraceae]), the first sequenced member of the Magnoliidae comprising four orders (Laurales, Magnoliales, Canellales, and Piperales) and over 9,000 species. Phylogenomic analysis of 13 representative seed plant genomes indicates that magnoliid and eudicot lineages share more recent common ancestry relative to monocots. Two whole genome duplication events were inferred within the magnoliid lineage, one before divergence of Laurales and Magnoliales and the other within the Lauraceae. Small scale segmental duplications and tandem duplications also contributed to innovation in the evolutionary history of Cinnamomum. For example, expansion of terpenoid synthase subfamilies within the Laurales spawned the diversity of Cinnamomum monoterpenes and sesquiterpenes.

genomics↗