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Liao, F.

Publications and source records attributed to Liao, F..

13 recordsLinked to original sources

Cerebrovascular Single-Nucleus RNA-Seq Reveals Heat Shock Activation and Vascular Remodeling in Alzheimer's Disease and Primary Tauopathies

Cerebrovascular alterations are widely observed in both Alzheimers Disease (AD) and primary tauopathies. Here, we hypothesized that mechanisms of cerebrovascular alterations are shared between AD and primary tauopathies. We performed single-nucleus RNA sequencing of postmortem human inferior temporal gyrus to characterize transcriptomic changes across cerebrovascular cell types in AD and primary tauopathies (Corticobasal Degeneration, Picks disease, and Progressive Supranuclear Palsy). Differential gene expression analyses revealed disease-specific transcriptional programs across vascular cell populations. However, genes involved in the heat-shock response were consistently upregulated across all diseases, suggesting a conserved cerebrovascular stress response during neurodegeneration. We further identified marked cerebrovascular remodeling in AD relative to primary tauopathies, along with dysregulation of genes mapping to AD risk loci in endothelial cells. Transcriptomic findings were validated using tissue clearing, light-sheet microscopy, and immunofluorescence quantification of vascular markers. These results define a conserved vascular stress program alongside AD-specific remodeling, highlighting the vasculature as a therapeutic target in neurodegeneration.

neuroscience↗

Molecular Imaging of the TGF-β Activating Integrin αvβ6 Detects Chronic Lung Allograft Dysfunction

TGF-{beta}-activating integrins promote solid-organ fibrosis, suggesting their use as a molecular marker of disease. Chronic lung allograft dysfunction (CLAD), a progressive fibrotic complication that limits lung transplant survival, is driven by intragraft TGF-{beta} activation. However, the expression patterns of TGF-{beta}-activating integrins remain undefined in lung transplants. Single-cell RNA sequencing in a mouse CLAD model revealed high levels of the TGF-{beta}-activating integrin v{beta}6, which was mainly localized to fibrosis-associated Krt8+ transitional alveolar cells (AT1/2), while tolerant transplants lacked both v{beta}6 expression and Krt8+AT1/2 cells. Molecular imaging with a newly developed positron emission tomography radiotracer specific for v{beta}6, [64Cu]Cu-DOTA-A20-K16R, showed significantly higher uptake in CLAD versus tolerant transplants. In contrast, [64Cu]Cu-DOTA-A20-K16R allograft uptake was reduced by treatments that lowered v{beta}6 expression and CLAD severity. Finally, [64Cu]Cu-DOTA-A20-K16R autoradiographic analysis on human explanted lungs with CLAD showed elevated activity that correlated with v{beta}6 expression. Collectively, these findings demonstrate the potential utility of v{beta}6 molecular imaging to detect CLAD pathogenesis.

immunology↗

Point mutation in sensor triples zinc levels in Sorghum bicolor

Zinc (Zn) deficiency is widespread in agricultural soils and it is also a common nutritional problem in humans. We previously discovered a Zn Sensor Motif (ZSM) in the Arabidopsis F-bZIP transcription factors, bZIP19 and bZIP23, which impacts the concentration of Zn in Arabidopsis plants. Sorghum (Sorghum bicolor (L.) Moench) is one of the most important cereals crops worldwide and here, using a large-scale sorghum mutant library, we report the identification of variants with a ZSM point mutation. We show that a cysteine substitution in the ZSM of the sorghum bZIP19/23 homolog causes a three-fold increase in Zn levels in sorghum seeds with no visible developmental penalty. Our work provides the first evidence that modulating the F-bZIP ZSM is a promising strategy for Zn biofortification in crops. This discovery paves the way to generate Zn biofortified crops and alleviate the global problems of Zn deficient soils and Zn malnutrition.

plant biology↗

Swine wastewater drives dissemination of high-risk blaNDM-positive Escherichia coli clones

Swine wastewater can accelerate the spread of antibiotic-resistant bacteria among animals, the environment, and humans. Therefore, the molecular epidemiological characteristics of carbapenemase-producing E. coli isolates from swine wastewater was investigated. In this study, a total of 100 no-cloning carbapenemase-producing (blaNDM-1, blaNDM-5 and blaOXA-48-like) E. coli isolates were recovered from 316 swine wastewater samples collected from 29 swine farm in Shandong, China. Of which, two isolates that co-harbored blaOXA-48-like and mcr-1, as well as five isolates that co-harbored blaNDM-5 and tet(X4). All isolates were multidrug-resistant (MDR), with a majority exhibiting resistance to meropenem, ciprofloxacin, imipenem and gentamicin. Whole genome sequencing (WGS) analysis indicated that these isolates were belonged to 12 distinct sequence types (STs), with the most prevalent STs being ST10 and ST5299. Additionally, Phylogenomic analysis revealed that clonal spread of blaNDM-positive ST10 E. coli isolates at swine wastewater in multiple cities, including Binzhou, Dezhou, Heze and Weihai. Meanwhile, a notable divergence in SNPs was observed in isolates from this study and public database, which indicates that these blaNDM-positive E. coli isolates have high genetic diversity. In addition, WGS analysis further revealed that blaNDM co-existed with other antibiotic resistance genes, conferring resistance to twelve classes of antimicrobials. This study underscores the importance of surveillance for blaNDM-harboring microbes in swine wastewater, and continuous monitoring in swine wastewater is essential for ensure human and environmental health. IMPORTANCEThe study described the NDM-positive E. coli strains isolated from swine wastewater, where it was associated with antibiotic exposure. Notably, swine wastewater was increasingly considered to be related to CRE hosts. Pathogens originating from this source can be transmitted to humans via direct and indirect contact, as well as through the ingestion or inhalation of contaminated water or aerosols. In addition, under the selective pressure of antibiotics, the co-harbored of blaOXA-48-like and mcr-1, blaNDM-5 and tet(X4) genes within the same host bacterium signifies the emergence of an extremely MDR pathogen, posing a grave threat to public health. Consequently, the monitoring of blaNDM in swine wastewater is critical for containing the transmission and persistence of carbapenem-resistant pathogens.

microbiology↗

Atg16l1 promotes lung transplant tolerance by regulating glycolysis in macrophages

Lung transplant survival is limited by the development of chronic lung allograft dysfunction (CLAD), a type of graft rejection that lacks effective treatments. Autophagy plays a crucial role in maintaining cellular homeostasis. In a single-nucleotide polymorphism screen, we found that lung recipients with two copies of a common hypofunctional genetic variant of autophagy-related 16-like 1 rs2241880 (ATG16L1T300A/T300A), known to deplete this protein from macrophages, were more likely to develop early CLAD. To understand this, we used a mouse orthotopic lung transplant model. Recipients encoding myeloid cell-specific deletion of Atg16l1 (Atg16l1{Delta}/{Delta}) or who harbor an engineered orthologous mutation (Atg16l1T316A/T316A) showed similar susceptibility to CLAD. Transcript profiling and mitochondrial tracking studies indicated that increased mitochondrial damage and decreased autophagic removal of mitochondria in Atg16l1-deficient macrophages were associated with heightened activation of the hypoxia-inducible factor 1 (Hif1) pathway and accumulation of glycolytic transcripts. Metabolic analysis revealed reduced oxidative phosphorylation, increased glycolytic activity, and higher IL-1{beta} expression in Atg16l1-deficient macrophages. Notably, the development of CLAD in Atg16l1{Delta}/{Delta} lung recipients could be significantly prevented by additionally deleting Hif1 in myeloid cells or by treating with the glycolysis inhibitor 2-deoxyglucose. Our results show how a common autophagy-related genetic variant disrupts macrophage metabolism and impairs lung transplant tolerance, pointing toward potential therapeutic strategies to combat CLAD.

immunology↗

An SR45-dependent exonic splicing enhancer is essential for regulating alternative splicing in Arabidopsis

Alternative splicing (AS) is a critical gene regulatory mechanism that underpins developmental plasticity and environmental adaptation in eukaryotes. Although numerous cis-elements and trans-factors governing AS have been characterized in animals, their functional roles in plants remain largely unexplored. We previously identified the Arabidopsis sot5 mutant, which exhibits leaf virescence due to a mutation in the conserved 5 splice site (5ss) of intron 7. Here, through characterization of a suppressor of sot5 (E61), we found that E61 harbors a G to A mutation in exon 8 of the SOT5 gene. Interestingly, this mutation creates a synonymous codon but disrupts the exonic splicing enhancer (ESE) motif (AAGAAGA), thereby reducing the splicing efficiency of the adjacent intron 7. Retention of this intron produces a functional protein that rescues the sot5 virescent phenotype. We confirmed the causal role of this ESE by using a cytidine base editor (CBE) to convert the ESE sequence to AAGAAAA or AAAAAAA in sot5. The edited plants phenocopied the suppressor E61. Genetic analyses revealed that mutations of SR45 encoding an RNA-binding protein but not its paralog SR45a similarly rescues the sot5 phenotype by impairing intron 7 splicing. Furthermore, we demonstrated that SR45 directly binds to the ESE motif in vitro, and that mutating the proximal ESEs in intron 2 of another SR45 target, GPDHC1 (Glycerol-3-Phosphate Dehydrogenase C1), recapitulates the splicing defect observed in the sr45 mutant. These findings establish that SR45 specifically recognizes AAG-repeat ESEs to enhance the splicing of adjacent weak introns, revealing a potent strategy for fine-tuning gene expression through targeted editing of splicing regulatory elements for crop improvement.

molecular biology↗

Impaired complement regulation drives chronic lung allograft dysfunction after lung transplantation.

A greater understanding of chronic lung allograft dysfunction (CLAD) pathobiology, the primary cause of mortality after lung transplantation, is needed to improve outcomes. The complement system links innate to adaptive immune responses and is activated early post-lung transplantation to form the C3 convertase, a critical enzyme that cleaves the central complement component C3. We hypothesized that LTx recipients with a genetic predisposition to enhanced complement activation have worse CLAD-free survival mediated through increased adaptive alloimmunity. We interrogated a known functional C3 polymorphism (C3R102G) that increases complement activation through impaired C3 convertase inactivation in two independent LTx recipient cohorts. C3R102G, identified in at least one out of three LTx recipients, was associated with worse CLAD-free survival, particularly in the subset of recipients who developed donor-specific antibodies (DSA). In a mouse orthotopic lung transplantation model, impaired recipient complement regulation resulted in more severe obstructive airway lesions when compared to wildtype controls, despite only moderate differences in graft-infiltrating effector T cells. Impaired complement regulation promoted the intragraft accumulation of memory B cells and antibody-secreting cells, resulting in increased DSA levels. In summary, genetic predisposition to complement activation is associated with B cell activation and worse CLAD-free survival. BRIEF SUMMARYLung transplant recipients genetically predisposed to impaired complement regulation demonstrate worse chronic rejection-free survival. This phenotype is associated with intragraft B cell-activation and donor-specific antibodies.

immunology↗

The Arabidopsis PPR protein EMB1006 interacts with both EMB1270 and CFM2 to facilitate plastid clpP1 intron2 splicing

Plastid intron splicing is an essential step for gene expression. Although many nucleus-encoded splicing factors have been identified for plastid intron splicing, how these proteins coordinately regulate intron splicing is unclear. Here we found that EMB1006, an Arabidopsis P-type PPR protein, is required for splicing several plastid introns including clpP1 intron 2 by analyzing the level of intron retention in its knockdown lines and RIP-qPCR (RNA immunoprecipitation and quantitative PCR) assay. In addition, RNA electrophoretic mobility shift assay (REMSA) showed that EMB1006 specifically binds to the sequence UUACCAAACGU close to the 3 end of clpP1 exon 2 in vitro. Furthermore, yeast two hybrid (Y2H), split luciferase complementation (Split-LUC) and semi-in vivo pull-down assays showed that EMB1006 interacts with both EMB1270 and CFM2, which also interact each other. Taken together, our data indicate that EMB1006 forms a complex with EMB1270 and CFM2 to facilitate clpP1 intron 2 splicing in chloroplasts.

plant biology↗

Astrocyte transcriptomic changes along the spatiotemporal progression of Alzheimer's disease

Astrocytes play a critical role in brain homeostasis and normal functions but their changes along the spatiotemporal progression of Alzheimers disease (AD) neuropathology remain largely unknown. Here we performed single-nucleus RNA-sequencing on brain regions along the stereotypical progression of AD pathology from donors ranging the entire normal aging-AD continuum comprising 628,943 astrocyte nuclei from 32 donors across 5 brain regions. We discovered temporal gene-expression-trajectories with gene sets differentially activated at various disease stages. Surprisingly, a gene set enriched in proteostasis and energy metabolism, was upregulated in late-stage but unexpectedly returned to baseline levels in end-stage, suggesting exhaustion of response in "burnt-out" astrocytes. The spatial gene-expression-trajectories revealed that astrocytic genes of tripartite synapses are dysregulated in parallel to the stereotypical progression of tangle pathology across regions. We identified astrocyte heterogeneity across brain regions with a continuum from homeostatic to reactive cells through "intermediate" transitional states. These findings suggest complex astrocytic dysfunction in AD neurodegeneration.

neuroscience↗

Reprogramming Alveolar Macrophage Responses to TGF-β Reveals CCR2+ Monocyte Activity that Promotes Bronchiolitis Obliterans Syndrome

Bronchiolitis obliterans syndrome (BOS) is a major impediment to lung transplant survival and is generally resistant to medical therapy. Extracorporeal photophoresis (ECP) is an immunomodulatory therapy that shows promise in stabilizing BOS patients but its mechanisms of action are unclear. In a mouse lung transplant model, we show that ECP blunts alloimmune responses and inhibits BOS through lowering airway TGF-{beta} bioavailability without altering its expression. Surprisingly, ECP-treated leukocytes are engulfed primarily by alveolar macrophages (AM), which become reprogrammed to become less responsive to TGF-{beta} and reduce TGF-{beta} bioavailability through secretion of the TGF-{beta} antagonist Decorin. In untreated recipients, high airway TGF-{beta} activity stimulates AM to express CCL2 leading to CCR2+ monocyte-driven BOS development. Moreover, we find TGF-{beta} receptor 2-dependent differentiation of CCR2+ monocytes is required for the generation of monocyte-derived AM, which in turn promote BOS by expanding tissue-resident memory CD8+ T cells that inflict airway injury through Blimp-1-mediated Granzyme B expression. Thus, through studying the effects of ECP, we have identified an AM functional plasticity that controls a TGF-{beta}-dependent network, which couples CCR2+ monocyte recruitment and differentiation to alloimmunity and BOS. Alveolar macrophage plasticity can be harnessed to prevent Bronchiolitis Obliterans Syndrome.

immunology↗

A Phosphorus-Limitation Induced, Functionally Conserved DUF506 Protein is a Repressor of Root Hair Elongation in Arabidopsis thaliana

Root hairs (RHs) function in nutrient and water acquisition, root metabolite exudation, soil anchorage and plant-microbe interactions. Longer or more abundant RHs are potential breeding traits for developing crops that are more resource-use efficient and can improve soil health. RH elongation is controlled by both environmental and endogenous factors. While many genes are known to promote RH elongation, relatively little is known about genes and mechanisms that constrain RH growth. Here we demonstrate that a DOMAIN OF UNKNOWN FUNCTION 506 (DUF506) protein, AT3G25240, negatively regulates Arabidopsis thaliana RH growth. The AT3G25240 gene is strongly and specifically induced during P-limitation. Mutants of this gene, which we call REPRESSOR OF EXCESSIVE ROOT HAIR ELONGATION 1 (RXR1), have much longer RHs, while over-expression of the gene results in much shorter RHs. RXR1 physically interacts with a Rab-GTPase (RXR2), and an rxr2 mutant phenocopies the rxr1 mutant. Overexpression of a Brachypodium distachyon RXR1 homolog resulted in repression of RH elongation in Brachypodium. Taken together, our results reveal a DUF506-GTPase module with a prominent role in repression of RH elongation that is conserved in monocots and dicots.

plant biology↗

The Arabidopsis bZIP19 and bZIP23 transcription factors act as zinc-sensors to control plant zinc status

Zinc (Zn) is an essential micronutrient for plants and animals because of its structural and catalytic roles in many proteins. Zn deficiency affects ca. two billion people, mainly those living on plant-based diets that rely on crops from Zn deficient soils. Plants maintain adequate Zn levels through tightly regulated Zn homeostasis mechanisms, involving Zn uptake, distribution and storage, but it was not known how they sense Zn status. We use in vitro and in planta approaches to show that the Arabidopsis thaliana F-group bZIP transcription factors bZIP19 and bZIP23, which are the central regulators of the Zn deficiency response, act as Zn sensors by binding Zn2+ ions to a Zn sensor motif (ZSM). Deletions or modifications of this ZSM disrupts Zn binding, leading to a constitutive transcriptional Zn deficiency response, which causes a significant increase in plant and seed Zn accumulation. Since the ZSM is highly conserved in F-bZIPs across land plants, the identification of the first plant Zn-sensor will promote new strategies to improve the Zn nutritional quality of plant-derived food and feed, and contribute to tackle the global Zn deficiency health problem.Competing Interest StatementThe authors have declared no competing interest.View Full Text

plant biology↗

Emergence of V1 connectivity pattern and Hebbian rule in a performance-optimized artificial neural network

The connectivity pattern and function of the recurrent connections in the primary visual cortex (V1) have been studied for a long time. But the underlying mechanism remains elusive. We hypothesize that the recurrent connectivity is a result of performance optimization in recognizing images. To test this idea, we added recurrent connections within the first convolutional layer in a standard convolutional neural network, mimicking the recurrent connections in the V1, then trained the network for image classification using the back-propagation algorithm. We found that the trained connectivity pattern was similar to those discovered in biological experiments. According to their connectivity, the neurons were categorized into simple and complex neurons. The recurrent synaptic weight between two simple neurons is determined by the inner product of their receptive fields, which is consistent with the Hebbian rule. Functionally, the recurrent connections linearly amplify the feedforward inputs to simple neurons and determine the properties of complex neurons. The agreement between the model results and biological findings suggests that it is possible to use deep learning to further our understanding of the connectome.

neuroscience↗