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Ding, S.

Publications and source records attributed to Ding, S..

At least 19 recordsLinked to original sources

Rotavirus NSP1 activates human NLRP1 inflammasome

While inflammasomes detect and defend against pathogens, the precise mechanisms by which enteric viruses trigger these complexes, and the specific viral components involved remain incompletely understood. In this study, we demonstrate that rotavirus infection robustly induced human NLRP1 inflammasome activation via p38 mitogen-activated protein kinase (MAPK)-dependent and -independent pathways. Utilizing cell lines reconstituted with NLRP1 signaling and reverse genetics-rescued recombinant rotaviruses, we identified non-structural protein 1 (NSP1), a well-characterized viral antagonist of host interferon signaling, as an activator of the NLRP1 inflammasome in the absence of double-stranded RNA. Domain mapping analysis revealed that the C-terminus of NSP1 but not the C-terminal IRF3-binding site was essential for triggering inflammasome activation. Mechanistically, we show that NSP1 induced the proteasomal degradation of NLRP1 to elicit its activation, a process dependent on host neddylation pathways and the Cullin-3/Elongin B/C ubiquitin ligase complex. Together, these findings suggest that RV engages parallel NLRP1 surveillance pathways, including a p38-dependent response to infection, and a novel NSP1-dependent pathway involving the ubiquitin-proteosome system, where a viral strategy aimed at host protein degradation inadvertently trips the human NLRP1 inflammasome wire.

microbiology↗

Matrix Viscoelasticity Regulates the Stemness and Multilineage differentiation of Primary Neural Progenitor-Stem Cells in 3D

Neural progenitor-stem cells (NPSCs) reside in mechanically dynamic brain microenvironments and give rise to neurons, astrocytes, and oligodendrocytes. Although recent studies have shown that matrix viscoelasticity can influence neural maturation and neurogenic differentiation, its role in primary NPSCs beyond neurogenesis remains less defined. How matrix viscoelasticity or stress relaxation regulates primary NPSC stemness, neuronal and glial differentiation, and the associated matrix-cell mechanotransduction pathways are not well understood. Here, we use alginate hydrogels with independently tunable stiffness and stress relaxation properties to investigate how matrix stress relaxation regulates the fate of primary subventricular zone (SVZ)-derived NPSCs in 3D. The results suggested that matrices with faster stress relaxation enhances stemness maintenance, radial glial-like marker expression, and differentiation of NPSCs toward neuronal, astrocytic, and oligodendrocytic lineages in the corresponding biochemical environments. In mixed neuronal/astrocytic differentiation conditions, fast-relaxing matrices preferentially promote neuronal differentiation. Mechanistically, NPSC responses to matrix stress relaxation involve integrin-mediated adhesion, actomyosin contractility, actin polymerization, and Piezo1 activity, with distinct contributions across differentiation lineages. Together, these findings reveal how matrix stress relaxation regulates primary NPSC stemness and multilineage differentiation through multiple mechanotransduction pathways in 3D.

neuroscience↗

Excessive cholesterol accumulation in microglia increases neuronal synaptic vulnerability to amyloid-beta

Cholesterol efflux is an important determinant of cellular lipid homeostasis. However, how microglial excessive cholesterol accumulation affects neuronal synaptic integrity remains poorly understood, particularly in the context of Alzheimer's disease. Here, we utilized a conditional knockout mouse model targeting the cholesterol transporters ABCA1 and ABCG1 in microglia. The microglia-specific ABCA1/ABCG1 deficiency triggered marked cholesterol accumulation, microglial hypertrophy, downregulation of the homeostatic marker P2ry12, and upregulation of the reactivity-associated marker CD11b, indicating shift toward a reactive phenotype. This phenotype was accompanied by increased reactive oxygen species, consistent with enhanced oxidative stress in ABCA1/ABCG1-deficient microglia compared with control. Using organotypic hippocampal slice cultures, we investigated the downstream neuronal outcomes of microglial ABCA1/ABCG1 deficiency. Under basal conditions, microglial ABCA1/ABCG1 knockdown did not significantly alter dendritic spine density in CA1 pyramidal neurons. However, upon exposure to amyloid-beta (A{beta}) stress, microglial ABCA1/ABCG1 deficiency markedly exacerbated dendritic spine loss in CA1 pyramidal neurons. Taken together, our findings highlight an important role for ABCA1/ABCG1-dependent cholesterol efflux in maintaining microglial homeostasis and limiting neuronal synaptic vulnerability to A{beta}-associated stress. These results support further investigation of microglial cholesterol transport as a potential target for preserving synaptic resilience in Alzheimer's disease.

neuroscience↗

Neutrophils rapidly release nucleoli-stored IFNα during infection

Type I interferons (IFN-I) are critical for antiviral defense but can drive severe pathology when dysregulated. Excess IFN-I is associated with prominent neutrophil accumulation; however, the contribution of neutrophils to IFN-I overproduction remains underexplored. In all cell types previously studied, IFN-I is synthesized de novo following sensing of microbial or host-derived inflammatory stimuli. Contrary to this paradigm, we find that neutrophils express IFN during development and store it in the nucleolus, a membrane-less intranuclear condensate classically functioning in ribosome biogenesis. TLR-mediated bacterial sensing induces a nucleolar stress response in neutrophils that triggers rapid release of nucleoli-stored IFN independent of de novo protein synthesis. These findings reveal that neutrophils have repurposed the nucleolus as a cytokine storage and secretory organelle, identify the first naturally occurring immunoregulatory function of nucleolar stress, and provide insight into the relationship between detrimental IFN-I levels and neutrophil accumulation.

immunology↗

Benthic diatoms navigate shear flows via hydrodynamic rolling and active gliding

Navigating fluid flow is a fundamental challenge for microbial life across diverse aquatic environments. While rheotaxis in swimming microorganisms has been extensively studied, it remains unresolved whether near-bed shear merely perturbs gliding motility or instead provides directional cues for active navigation on surfaces. Here we show that the benthic diatom Navicula cryptocephala utilises a purely mechanical strategy to achieve downstream rheotaxis and anisotropic spreading on submerged surfaces. Single-cell ellipsoidal tracking reveals a direction-dependent angular response that reorients gliding cells towards the downstream direction. Using interference reflection microscopy, we further reveal that shear induces rolling of obliquely gliding cells, laterally shifting the cell-substrate contact site. This shift renders raphe-based propulsion non-collinear with substrate friction, generating a downstream-restoring yaw torque. Crucially, our results rule out alternative explanations based on longitudinal shifts of the raphe contact site or direct hydrodynamic yaw torque. A minimal stochastic model confirms that this mechanical reorientation alone is sufficient to reproduce the observed drift and diffusion patterns, without invoking either orientation-dependent switching between motility states or orientation-dependent dwell times of those states. Our findings uncover a mechanism by which ambient shear is converted into directional guidance for active surface motility, providing new insights into microbial transport, retention, and resilience on submerged surfaces.

biophysics↗

Coronavirus envelope protein drives iron sensing disorder by hijacking the TAp73-FDXR axis

Iron overload is increasingly recognized as a critical contributor to coronavirus pathogenesis1, yet the underlying induction mechanisms remain unclear. Here, we uncover a fundamental pathway by which coronavirus drives IRP1 RNA-binding activity to induce iron accumulation2 via targeting the TAp73-FDXR axis. Specifically, coronavirus infection represses transcription of FDXR (encoding the key rate-limiting enzyme in host iron-sulfur cluster synthesis3), thereby impairing host iron-sulfur cluster generation to trigger the functional conversion of the cytosolic aconitase 1 (ACO1) into iron-regulatory protein 1 (IRP1)4, ultimately leading to the hosts persistently false perception of iron deficiency. We identify TAp73 as the primary transcription factor governing FDXR expression, and demonstrate that the coronavirus envelope protein (CoV-E) orchestrates TAp73 nuclear export. Subsequently, CoV-E binds TAp73 through a critical valine residue within its C-terminal PBM domain, inducing the K48-linked ubiquitination and proteasomal degradation of TAp73. Furthermore, we developed a CoV-E-targeting molecule, DPTP-FC, which blocks CoV-E-TAp73 interaction via forming steric hindrance and effectively alleviates iron accumulation and tissue damage caused by PEDV, PDCoV, and SARS-CoV-2 infection. Our study reveals the central role of the TAp73-FDXR axis in CoV-induced iron accumulation, highlighting CoV-E as an attractive antiviral target and DPTP-FC as a promising therapeutic candidate.

microbiology↗

Therapeutic targeting inflammation linking periodontitis and atherosclerotic comorbidities using cell-free DNA-capturing nanomaterials

Periodontitis-associated systemic inflammation makes it a great challenge to explore therapeutic options applicable to periodontitis and atherosclerotic comorbidities. Here, we identify the crucial role of cell-free DNA (cfDNA) that underlies these comorbidities. Hypothesizing cfDNA as a therapeutic target, we engineer polyamidoamine dendrimer-functionalized nanomaterials to modulate such local-systemic inflammatory crosstalk. Periodontium-originated DNA can be systemically captured by cationic nanomaterials, and capturing cfDNA, whether locally or systemically, alleviates both periodontitis and atherosclerosis prior to severe atherosclerotic development in vivo. The transcriptomic and single-cell RNA sequencing analyses together reveal that cfDNA-capturing nanomaterials regulate inflammatory foam cell transformation in macrophages by modulating the expression of lipid-related foamy markers Spp1 and Fabp4. This study provides a proof of concept for cfDNA-driven periodontitis-atherosclerosis crosstalk, and offers a cfDNA-capturing nanoplatform for therapeutic intervention targeting periodontitis and atherosclerotic comorbidities in a holistic fashion.

immunology↗

Metformin Stabilizes the Abdominal Aorta in Aneurysm by Restoring VSMC Mitochondrial Homeostasis via the AMPK-SIRT1-PGC-1α Axis

BACKGROUNDAbdominal aortic aneurysm (AAA) is a life-threatening condition with >80% mortality upon rupture and no effective pharmacotherapy available. Despite epidemiological evidence linking metformin use to reduced AAA progression, its mechanism remains elusive. Notably, peroxisome proliferator-activated receptor {gamma} coactivator 1 (PGC-1, encoded by Ppargc1a) is downregulated in human AAA, yet its functional role in metformins protection is unknown. METHODSWe employed porcine pancreatic elastase (PPE)-induced murine AAA, VSMC-specific Ppargc1a knockout (Ppargc1aVSMC-KO), primary VSMC senescence models, and pharmacological inhibition (Compound C for AMPK; Ex-527 for SIRT1) to define the AMPK-SIRT1-PGC-1 axis. RESULTSMetformin significantly inhibited AAA expansion, suppressed VSMC senescence (p53/p21{downarrow}, SA-{beta}-gal{downarrow}), and preserved contractile phenotype (SMTN{uparrow}, IL-6/TNF-{downarrow}). Crucially, all benefits were abrogated in Ppargc1aVSMC-KO mice, which exhibited accelerated aneurysm growth, mitochondrial fragmentation, ATP depletion, and ROS accumulation. Mechanistically, metformin activated AMPK/SIRT1 to upregulate PGC-1; AMPK or SIRT1 inhibition blocked this cascade and reversed protection. CONCLUSIONMetformin restrains AAA by restoring VSMC mitochondrial homeostasis via the AMPK/SIRT1[->]PGC-1 axis, positioning PGC-1 as a non-redundant, cell-autonomous guardian against vascular degeneration. These findings provide a mechanistic foundation for repurposing metformin and developing PGC-1-targeted therapies in AAA.

cell biology↗

Hyperhomocysteinemia does not increase the risk of intracerebral hemorrhage in hypertensive mice

ObjectiveHyperhomocysteinemia (HHcy) affects approximately 75% of the population in China, and there is currently controversy regarding whether HHcy increases the risk of hemorrhagic stroke. This study aims to investigate the effects of high homocysteine (Hcy) levels on cerebral hemorrhage in hypertensive mice by administering homocysteine to them. MethodsMale C57BL/6 mice at 8 months of age were used in the experiment. The study was divided into two groups: the Hcy + AngII + L - NAME group and the AngII + L - NAME group. Magnetic resonance imaging (MRI) was performed when the mice exhibited signs of cerebral hemorrhage.After the hemorrhage, anesthesia was induced to euthanize the animals, and then the brain tissue was fixed. The total rearing period was 18 weeks. The relationship between homocysteine and stroke was described by plotting survival curves. The location and quantity of cerebral hemorrhage were determined through histopathological staining. ResultsThe serum Hcy concentration of mice fed with Hcy for 6 weeks increased to 23.07 mol/L, and the blood pressure ranged from 170 to 180 mmHg. The number of deaths due to cerebral hemorrhage was 10 in both the AngII + L - NAME + Hcy group and the AngII + L - NAME group. The p - value of the survival curves between the two groups was 0.162, indicating no statistically significant difference. ConclusionThe results demonstrated that elevated homocysteine levels did not influence the incidence of intracerebral hemorrhage in hypertensive mice. Hyperhomocysteinemia does not increase the risk of intracerebral hemorrhage in hypertensive mice

neuroscience↗

Injury-transduced SerpinOLs modulate neuroinflammation and glial activation in the diseased and non-diseased CNS

Oligodendroglial dysfunction is common in CNS diseases and injuries, but the molecular and functional responses of oligodendroglia to CNS pathologies remain poorly defined. Here, we report that oligodendrocytes (OLs) respond to demyelinating diseases by dysregulating serine protease inhibitor clade A member 3N (SERPINA3N). Homeostatic OLs transition to Serpina3n-expressing OLs (SerpinOLs) under other diseased conditions including stroke, endotoxicity, neurodegeneration, neurotrauma, and non-diseased healthy aging conditions. Mechanistically, general neuroinflammation or inflammatory mediators is insufficient for SerpinOL transition. Instead, oligodendrocyte damage/injury, even in the absence of neuroinflammation or glial activation, is sufficient for the transition. Phenotypically, SerpinOLs are characterized by molecular signatures of inflammatory and immune regulation and STAT3 signaling activation. Functionally, SerpinOLs exacerbate neuroinflammation and promote glial activation toward pro-inflammatory and neurodegenerative states. Together, our findings suggest SerpinOLs are a common population of injury-transduced OLs that amplify neuroinflammation and glial activation in the diseased and non-diseased CNS through SERPINA3N secretion. Our findings provide new insights into myelination-independent role of OLs in regulating CNS pathophysiology.

neuroscience↗

An Advanced Humanized Systemic Lupus Erythematosus Model Enables Parallel Profiling of B Cell-Targeted Therapies

B cell-targeted therapies represent a transformative frontier for systemic lupus erythematosus (SLE) intervention, yet clinical recommendation of specific treatment is hampered by the challenge to perform head-to-head comparisons of efficacy-toxicity trade-offs and tissue-specific impacts in patients. To address this gap, an advanced Toll-like receptor 7 (TLR7) agonist-induced SLE model is developed in a NCG-M (NOD-Prkdcem26Cd52Il2rgem26Cd22Rosa26em1Cin(hCSF2&IL3&KITLG)/Gpt) human immune system (HIS) mice. This model enables parallel evaluation of multiple B cell-directed therapies within a controlled cohort study. It recapitulates core SLE pathologies--including immune effector cell augmentation, autoantibody production and glomerulonephritis--within 2 months, demonstrating greater severity and clinical fidelity than conventional pristane-induced systems. Validated through replication of clinical responses to rituximab and belimumab, the platform directly compares two emerging modalities: universal chimeric antigen receptor-T cells (UCAR-T) elicits delayed but profound B-cell reset correlating with superior reduction in renal pathology and autoantibodies, while T cell engagers (TCEs) mediate rapid yet partial B-cell depletion and transient efficacy. UCAR-T concurrently induces greater acute inflammatory responses, aligning with its distinct toxicity profile. By resolving therapy-specific effects on human immune dynamics and symptom control, this study empowers context-specific therapeutic selection for SLE, advancing tailored management strategies.

immunology↗

ProChoreo: De novo Binder Design from Conformational Ensembles with Generative Deep Learning

Deep learning has transformed protein structure prediction and de novo protein design; however, most existing frameworks operate on a single static conformation and underutilize the conformational heterogeneity that governs protein binding and function. We introduce ProChoreo, a generalizable framework for de novo binder design that explicitly incorporates conformational ensembles. ProChoreo is pretrained with multimodal contrastive learning to align protein sequences with corresponding molecular dynamics (MD)-derived ensembles, producing a shared latent representation that captures both sequence-level and dynamic structural information. This representation is then integrated into an autoregressive generator to design protein binders conditioned on receptor sequences. Designed binders are evaluated using Boltz 1 for complex structure and interaction quality, followed by MD simulations of complexes with two representative receptors: the human sweet taste receptor TAS1R2 and FGFR2. ProChoreo designs binders that encode conformational features, highlighting dynamics-informed design as a route to protein design.

bioinformatics↗

Two orthogonal MAP3K-driven pathways of NLRP1 inflammasome activation revealed by poisonous beetles.

Environmental toxins that cause irritant dermatitis remain poorly understood as activators of innate immune pathways. Here, we identify rove beetle (Paederus) and blister beetle (Meloidae) toxins as previously unrecognized triggers of the human NLRP1 inflammasome in keratinocytes. Rove beetles, likely through the ribosome inhibitor pederin, activate NLRP1 via translational stalling and the ZAK-dependent ribotoxic stress response. In contrast, the phosphatase inhibitor cantharidin from blister beetles induces NLRP1 through TAK1-driven hyperphosphorylation of its linker region, independent of ZAK. In their hyperactivated states, ZAK and TAK1 share overlapping phosphosites on the NLRP1 disordered linker, including a common essential TZ motif. In addition, we show that TAK1 and ZAK are jointly responsible for NLRP1 linker phosphorylation and activation caused by dsRNA and CHIKV infection. These findings reveal medically relevant insect toxins as activators of NLRP1, and uncover parallel MAP3 kinase pathways as converging upstream activating signals for the human NLRP1 inflammasome. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=172 HEIGHT=200 SRC="FIGDIR/small/701189v1_ufig1.gif" ALT="Figure 1000"> View larger version (50K): org.highwire.dtl.DTLVardef@ee34b9org.highwire.dtl.DTLVardef@c79ec9org.highwire.dtl.DTLVardef@189c373org.highwire.dtl.DTLVardef@17ec853_HPS_FORMAT_FIGEXP M_FIG C_FIG KEY POINTSTwo dermatitis-causing beetle species induce NLRP1-driven pyroptosis of human keratinocytes Rove beetles, likely via pederin, activate NLRP1 via ribosome inhibition and ZAK[a]-driven RSR Cantharidin from blister beetles activates human via TAK1-, instead of ZAK[a]-driven hyperphosphorylation of the NLRP1 linker region Shared phosphosites by TAK1 and ZAK[a] on NLRP1 contribute to dsRNA-driven NLRP1 activation

immunology↗

Demonstrating and engineering the de novo synthesis of two aromatic chemicals estragole and anethole in Escherichia coli

Estragole and anethole are the major flavoring and aroma components of the essential oils extracted from basil (Ocimum basilicum L.), anise (Pimpinella anisum), star anise (Illicium verum), and fennel (Foeniculum vulgare). Besides, they also exhibit bioactivities, such as antioxidation, antimicrobial, immunomodulation, inti-inflammation, and anti-diabetes. These properties make them being faced with substantial applications in the industries of food, cosmetics, pharmaceutics, and agriculture. Commercial estragole and anethole are currently obtained from extraction from their original plants, which suffers from unstable quality and resources. Microbial synthesis is a promising alternative approach to sustainably obtain estragole and anethole, but has not been achieved. In this study, we modularly redesigned the synthetic pathways based on the Escherichia coli chassis. Firstly, a p-coumaryl alcohol over-accumulator (436.28 mg/L) was engineered to facilitate the validation of the undemonstrated downstream module. De novo biosynthesis of estragole and anethole was achieved by stepwise analysis and BioBricks assembly. The intracellular availability of S-adenosyl-L-methionine (SAM) was revealed to be the key limiting factor, and was enhanced by deregulating the synthesis. Finally, the productions of estragole and anethole were improved by 246.88% and 202.44% compared with the initial strains. This study represents the first synthesis of estragole and anethole in microbial chassis, and the demonstration of microbial synthesis of propenyl phenols. Besides, it provided an alternative sustainable approach to obtain flavoring and aroma chemicals.

synthetic biology↗

Signal peptidase complex mediates rotavirus VP7 processing and virion assembly

For viruses that replicate in the proximity of or bud at the endoplasmic reticulum (ER) associated membranes, proper processing of their glycoproteins is critical for successful infection. Rotavirus outer capsid protein VP7 is an ER-resident protein. However, its N-terminal signal peptide is removed by an unknown proteolytic mechanism. In this study, we leveraged tandem affinity purification followed by high-resolution mass spectrometry to profile host proteins that interact with VP7. We identified members of the signal peptidase complex (SPC) family as important host factors that facilitate rotavirus infection. CRISPR knockout or siRNA knockdown of distinct SPC subunits resulted in significant decrease in infectious rotavirus titers in a viral strain- and cell type-independent manner. While viral transcription, translation, and replication were not altered in the absence of SPC, we observed formation of abnormal viral particles by transmission electron microscopy (TEM) in SPCS1 knockout cells. Mechanistically, loss of SPC proteins led to inefficient cleavage of VP7 signal peptide and severely impaired the final steps of virion maturation and assembly. Additionally, we identified residue E256 within VP7 as a key site for SPC binding. An E to R mutation abolished VP7 interaction with SPC and subsequently led to reduced viral infectivity. Taken together, these findings define SPC as a novel regulator of VP7 maturation and rotavirus assembly and highlight its role as a novel cellular target for potentially broad-spectrum antiviral therapeutic development. Author summaryPrevious reports demonstrated that SPC is involved in the replication cycles of several members of the flavivirus family and human T-cell leukemia virus type 1 (HTLV-1). As an ER-resident outer capsid protein, rotavirus VP7 must undergo proper post-translational modifications, including the cleavage of its N-terminal signal peptide, to be functionally incorporated into mature virions. However, the processing mechanism remains unknown. For the first time, our study identifies SPC as an essential regulator of rotavirus assembly by mediating the cleavage of the VP7 signal peptide. Loss of SPC impairs VP7 signal peptide cleavage and maturation, thereby disrupting correct virion assembly and reducing infectious particle production. Using Alphafold3, we predicted the VP7 residue E256 to be at the binding interface with SPC complex. Experimentally, mutation of glutamic acid to arginine (E256R) substantially weakens this interaction and results in reduced viral propagation. Our findings unveil a novel post-translational checkpoint in rotavirus regulated by SPC and underscore the promise of SPC as a broad-spectrum antiviral target, especially for rotavirus, flavivirus, and HTLV-1, whose viral glycoproteins and structural proteins require SPC processing for proper maturation.

microbiology↗

Pharmacological Induction of Irreversible Senescence in Drug-Tolerant Persister Cells Prevents Tumor Relapse

Despite substantial advances in targeted therapies, most patients with advanced cancers ultimately relapse. This relapse is frequently seeded by drug-tolerant persister cells (DTPs), which persist as minimal residual disease (MRD) by adopting a reversible quiescent state and later reacquire proliferative capacity under ongoing treatment. To address this, we sought to convert quiescent DTPs into an irreversible, non-proliferative state by pharmacologically inducing senescence. Through large-scale chemical screening and combination optimization, we identified SAHA plus tilorone dihydrochloride (SIC) as a regimen that robustly induces senescence in melanoma DTPs and abolishes their proliferative potential in vitro. Mechanistically, SAHA relieves HDAC1-mediated repression of HMGA2, a key senescence driver, while tilorone synergistically inhibits autophagy to promote a fully senescent state. In a melanoma xenograft mouse model receiving MAPK-targeted therapy, SIC treatment significantly suppressed MRD progression. Importantly, SIC also induced robust senescence across diverse DTP models irrespective of tumor origin, mutational background, or prior treatment. Collectively, these findings provide proof-of-concept that converting DTPs from reversible quiescence to permanent senescence represents an effective strategy to prevent relapse under targeted therapy and position SIC as a broadly applicable pharmacological approach for durable control of residual disease in advanced cancers.

cancer biology↗

Progressive Loss of Astrocytic AIBP Expression during Alzheimer's Disease Pathology

Astrocytes and microglia play crucial roles in mediating neuroinflammation during Alzheimers disease (AD) progression. ApoA-I binding protein (APOA1BP, also known as AIBP/NAXE) attenuates neuroinflammation by blocking amyloid {beta}-induced TLR4 inflammaraft formation and oxidative stress. Apoa1bp knockout in APP/PS1 mice exacerbates microgliosis, increases amyloid plaque burden, neuronal cell loss, and reduces survival at 6 months. Although APOA1BP mRNA is ubiquitously expressed in humans, its cell-type-specific distribution in the brain remains unclear. To examine AIBP protein expression in the human brain, we performed immunohistochemistry on hippocampal sections from postmortem brain specimens from subjects aged 75-96 of both sexes. Using GFAP and IBA1 to label astrocytes and microglia, respectively, we found that AIBP protein was highly expressed in astrocytes, but not in microglia. Stratification of subjects by Braak stage (I-II, III-IV, V-VI) revealed a progressive decline in astrocytic AIBP expression with advancing AD pathology. Meta-analysis of RNA-seq profiling indicated enriched Apoa1bp expression in adult mouse astrocytes. Systemic Apoa1bp knockout in the APP/PS1 mouse exacerbated astrogliosis. These findings demonstrate that AIBP is predominantly expressed in astrocytes and its expression declines with AD progression, suggesting a potential role for AIBP in astrocyte-mediated neuroprotection and AD pathogenesis.

neuroscience↗

Accurate and efficient phylogenetic inference through end-to-end deep learning

Accurate phylogenetic inference is crucial for understanding evolutionary relationships among species. Deep learning technique has been introduced for phylogenetic inference; however, the existing deep learning-based approaches either suffer from limited accuracy as they split inference into several disjoint stages, or exhibit low efficiency and hardly apply to the cases with over 20 species. Here we present an accurate and efficient approach to phylogenetic inference. Our approach, called NeuralNJ, employs an end-to-end framework that directly constructs phylogenetic trees from the input taxa, thus effectively avoiding the inaccuracy incurred by the split inference stages. The key innovation of NeuralNJ lies in its learnable neighbor joining mechanism, which iteratively joins neighbors guided by learned priority scores and thereby achieves accurate tree reconstruction. The inference accuracy is further enhanced through incorporating reinforcement learning-based tree search. Using both simulated and empirical data as representatives, we demonstrate that NeuralNJ can effectively infer phylogenetic tree with improved computational efficiency and reconstruction accuracy. The study paves the way to accurate and efficient phylogenetic inference for hundreds of taxa in complex evolutionary scenarios.

bioinformatics↗