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Biology subjects

Qiao, G.

Publications and source records attributed to Qiao, G..

9 recordsLinked to original sources

PerturbTrace: Evaluating Feedback Use by AI Co-Scientist Agents in Perturbation Discovery

Recent advances in AI co-scientists have brought LLM agents into closed-loop experimental design. However, whether these agents use feedback from earlier rounds to revise subsequent experimental decisions remains unclear. We address this question with PerturbTrace, which evaluates each round-to-round transition through Feedback-to-State, State-to-Action, and Action-to-Outcome. These stages assess whether feedback is reflected in the agent's rationale and perturbation-selection strategy, whether the stated strategy guides the next perturbation batch, and whether that batch yields more hits than expected under random sampling. We evaluate four LLM agents on 17 screen-derived tasks and compare them with random selection, active learning, and LLM-guided Bayesian optimization baselines. Each agent outperforms the strongest non-agent method on at least 15 of the 17 tasks, yet controlled evaluations across six tasks show no consistent advantage from true feedback over random or no feedback. Among 576 transitions under true or random feedback, only 43 (7.5%) complete the full Feedback-State-Action-Outcome sequence, including 25 under random feedback. These findings show that high final recall does not necessarily indicate effective feedback use. They also highlight the need to evaluate closed-loop scientific agents by both their discovery performance and whether feedback changes their subsequent decisions.

bioinformatics↗

Real-time in vivo imaging of rodent brain response to hypoperfusion enabled by remotely controlled elastomeric micro-balloons

Current preclinical models of ischemic stroke in mice do not permit simultaneous and continuous in vivo brain imaging during the peri-stroke period, therefore missing critical pathophysiological events that could be pivotal for stroke management at the early stage. Here we report remote control of the blood flow of cerebral arteries in live mice continuously at different states to induce stroke in a precise, reliable, and reversible manner. The sub-millimeter scale micro-balloons can expand more than four times their initial diameter, featuring a monolithic elastomeric wall with selectively stiffened regions for controlled inflation and elasticity depending on the target vessels. By allowing for the control of common carotid artery diameter through a cuff pressing against the artery, the micro-balloon recapitulates clinically relevant haemodynamics in a mouse model of global brain ischemia, evidenced by real-time imaging of the brain through intravital microscopy and magnetic resonance imaging. The presented micro-balloons hold significant potential to improve the treatment of stroke patients for minimally invasive intervention and in vivo imaging of the pathophysiological events in the peri-stroke phase.

bioengineering↗

Intravital Multimodal Imaging of Human Cortical Organoids for Chronic Stroke Treatment in Mice

Chronic stroke leads to enduring neurological deficits and remains a major clinical challenge. Human induced pluripotent stem cell (hiPSC)-derived cortical organoids (COs) offer promise for regenerative therapies, yet their application in chronic stroke remains understudied, in part due to limited tools for monitoring graft in vivo. Here, we present a Multimodal Imaging Platform for Organoid Tracking (MIPOT), which integrates MRI, bioluminescence imaging, light microscopy, and two-photon fluorescence microscopy to noninvasively track transplanted COs in the post-stroke brain over time. Using MIPOT, we verified precise delivery of COs into cleaned stroke cavities, observed progressive declines in viability within the first 10 days, and introduced labeling methods for functional in vivo tracking of COs at subcellular resolution. By 4 weeks post-transplantation, histological analysis revealed survival of COs in the cerebral cortex. Notably, COs engrafted into the hippocampus displayed enhanced maturation, underscoring the role of local microenvironments in graft integration. MIPOT enables dynamic, noninvasive evaluation of hiPSC COs in chronic stroke, providing a foundation for mechanistic studies and translational development of organoid-based therapies.

neuroscience↗

OPTRACE: Optical Imaging Guided Transplantation and Tracking of Cells in the Mouse Brain

Intracerebral cell transplantation holds great promise for treating stroke and other neurological disorders, but progress is hindered by challenges in precise cell delivery and limited methods for monitoring post-engraftment dynamics. To address these limitations, we introduce OPTRACE (OPtical imaging-guided Transplantation and tRAcking of CElls), a two-step framework that integrates precision delivery with longitudinal in vivo tracking to advance cell therapy. During transplantation, OPTRACE enables real-time visualization using cost-effective translucent glass micropipettes, guided by predictive modeling to optimize delivery parameters. A novel pulse-elevation injection technique further enhances the precision of superficial cortical engraftment. Following transplantation, multicolor labeling combined with two-photon fluorescence microscopy permits longitudinal single-cell tracking, revealing host microglial responses, and altered neuronal calcium signaling at the graft interface. By unifying high-resolution delivery and tracking strategies, OPTRACE provides a powerful platform for elucidating engraftment biology and accelerating the development of effective cell-based interventions for neurological diseases.

bioengineering↗

DICAR-JP Regulates Ribosome Migration, a New Theory of Mitochondrial Protein Production

BackgroundDICAR plays a cardioprotection of diabetic models. DICAR-JP, a short sequence of DICAR, may represent DICARs active functional domain. NAC is necessary for the heart tissue development. Addtionally, OGDHL is a metabolism regulator. In this study, we examine a new mechanism of DICAR via NAC/OGDHL on regulating cardiomyocyte metabolism in DCM. We also sought to elucidate the function of DICAR/DICAR-JP in modulating NAC-dependent production of OGDHL nascent peptides and their mitochondrial translocation, and we also aimed to optimize the DICAR-JP sequence to be better therapy on DCM. MethodsSPR was to investigate the binding interaction between DICAR-JP and NAC. The function of DICAR-JP and DICAR-JP45 on OGDHL nascent peptide transfection was detected by in vitro translation approach. Biotin-DICAR-JP was transfected to study the function of DICAR-JP, NAC and OGDHL. Untargeted metabolomics was utilized to characterize the metabolic reprogramming of cardiomyocytes. AAV9-DICAR-JP and DICAR-JP45 were constructed and administered to db/db mice for 1-2 months to assess their cardioprotective effects detected by Echocardiography confirmed mouse cardiac function. ResultsOur findings demonstrated that DICAR-JP be the functional domain that interacts with NAC to regulate OGDHL nascent peptide expression. Disruption of OGDHL expression reversed the metabolic reprogramming observed in diabetic cardiomyocytes, highlighting its crucial role in maintaining cardiac metabolic homeostasis. DICAR-JP facilitated the translocation of OGDHL nascent peptides from the cytoplasm to the mitochondria, leading us to hypothesize that DICAR-JP plays a key role in regulating ribosomal migration from the endoplasmic reticulum to the mitochondria. We refer to this process as the Ribosome Migration. In our studies using AAV9-mediated DICAR-JP and DICAR-JP45 overexpression in heart tissue. DICAR-JP and DICAR-JP45 both exhibited significant cardioprotective effects against diabetic cardiomyopathy (DCM), comparable to those observed with Empagliflozin. ConclusionsIn a conclusion, we propose a new endogenous nucleic acid candidate drug library, and a new molecular framework, the Ribosome Migration, which implicates the DICAR-JP/NAC/OGDHL nascent peptide axis in metabolic reprogramming related to DCM. This theory constructs a new mitochondrion protein from nuclear original protein. Moreover, DICAR-JP45 shows strong potential as a nucleic acid-based therapeutic candidate for treating DCM. Novelty and SignificanceO_ST_ABSWhat Is Known?C_ST_ABSDICAR is a new protective circular noncoding RNA for diabetic cardiomyopathy. NAC is located in ribosome and regulates new peptide production, which is also a key factor in heart tissue development. OGDHL can regulate different energy metabolism in mitochondria. What New Information Does This Article Contribute?DICAR-JP is the functional domain that interacts with NAC to regulate OGDHL nascent peptide expression. There is an interaction between DICAR-JP and NAC. DICAR-JP sequence is protected by NAC and NAC function is mediated by DICAR-JP. We called this RNA functional domain. OGDHL expression reversed the metabolic reprogramming observed in diabetic cardiomyocytes, highlighting its crucial role in maintaining cardiac metabolic homeostasis. DICAR-JP takes part in tanscription and translocation of OGDHL nascent peptides from the cytoplasm to the mitochondria via plasma ribosome. We call this process the Ribosome Migration Theory. DICAR-JP and DICAR-JP45 both exhibited significant cardioprotective effects against diabetic cardiomyopathy (DCM), comparable to those observed with Dapagliflozin (DAPA). Our study revealed a novel molecular framework, the Ribosome Migration Theory, which implicates the DICAR-JP/NAC/OGDHL nascent peptide axis in metabolic reprogramming related to DCM. Moreover, DICAR-JP45 shows strong potential as a nucleic acid-based therapeutic candidate for treating DCM.

pharmacology and toxicology↗

scKEPLM: Knowledge enhanced large-scale pre-trained language model for single-cell transcriptomics

The success of large-scale pre-trained language models in the Natural Language Processing (NLP) domain has encouraged their adoption in genomics and single-cell biology. Developing pre-trained models using the rapidly growing single-cell transcriptomic data helps to unravel the intricate language of cells. However, current single-cell pre-trained models primarily focus on learning gene and cell representations from extensive gene expression data, failing to fully comprehend the biological significance of the gene expression patterns and cell types they identify, which leads to limited interpretability and transferability. We propose scKEPLM, a knowledge-enhanced single-cell pre-training language model integrates a biology knowledge graph into the single-cell transcriptome pre-training process. scKEPLM covers over 41 million single-cell RNA sequences and 8.9 million gene relations. Through parallel pre-training of single-cell transcriptome sequences and genetic knowledge, combined with a Gaussian cross-attention mechanism, scKEPLM precisely aligns cell semantics with genetic information, to learn more accurate and comprehensive representations of single-cell transcriptomes. The introduction of knowledge enhancement has improved the identification of important genes in cells by scKEPLM, and greatly enriched the understanding of cell function and disease mechanism. The scKEPLM model has achieved state-of-the-art performance in more than 12 downstream tasks, including gene annotation, cell annotation, and drug response prediction, demonstrating strong generalization and transferability. Further exploration of the models interpretability demonstrates its adaptability to variations in gene expression patterns within cells under various physiological or pathological conditions.

bioinformatics↗

Precision-Cut Liver Slices as an ex vivo model to evaluate antifibrotic therapies for liver fibrosis and cirrhosis

BackgroundPrecision-Cut Liver Slices (PCLS) are an ex vivo culture model developed to study hepatic drug metabolism. One of the main benefits of this model is that it retains the structure and cellular composition of the native liver. PCLS also represents a potential model system to study liver fibrosis in a setting that more closely approximates in vivo pathology than in vitro methods. The aim of this study was to assess whether responses to antifibrotic interventions can be detected and quantified with PCLS. MethodsPCLS of 250 m thickness were prepared from four different murine fibrotic liver models: choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD), thioacetamide (TAA), diethylnitrosamine (DEN), and carbon tetrachloride (CCl4). PCLS were treated with 5 M Erlotinib for 72 hours. Histology and gene expression were then compared with in vivo murine experiments and TGF-{beta}1 activated hepatic stellate cells (HSCs). These types of PCLS characterization were also evaluated in PCLS from human cirrhotic liver. ResultsPCLS viability in culture was stable for 72 hours. Treatment of erlotinib, an EGFR inhibitor significantly inhibited the expression of profibrogenic genes Il6, Col1a1 and Timp1 in PCLS from CDAHFD-induced cirrhotic mice, and Il6, Col1a1 and Tgfb1 in PCLS from TAA-induced cirrhotic rats. Erlotinib treatment of PCLS from DEN-induced cirrhotic rats inhibited the expression of Col1a1, Timp1, Tgfb1 and Il6, which was consistent with the impact of erlotinib on Col1a1 and Tgfb1 expression in in vivo DEN-induced cirrhosis. Erlotinib treatment of PCLS from CCl4-induced cirrhosis caused reduced expression of Timp1, Col1a1 and Tgfb1, which was consistent with the effect of erlotinib in in vivo CCl4-induced cirrhosis. In addition, in HSCs at PCLS from normal mice, TGF-{beta}1 treatment upregulated Acta2 (SMA), while treatment with erlotinib inhibited the expression of Acta2. Similar expression results were observed in TGF-{beta}1 treated in vitro HSCs. Expression of MMPs and TIMPs, key regulators of fibrosis progression and regression, were also significantly altered under erlotinib treatment in PCLS. Expression changes under erlotinib treatment were also corroborated with PCLS from human cirrhosis samples. ConclusionThe responses to antifibrotic interventions can be detected and quantified with PCLS at the gene expression level. The antifibrotic effects of erlotinib are consistent between PCLS models of murine cirrhosis and those observed in vivo and in vitro. Similar effects were also reproduced in PCLS derived from patients with cirrhosis. PCLS is an excellent model to assess antifibrotic therapies that is aligned with the principles of Replacement, Reduction and Refinement (3Rs).

cell biology↗

A modular chemigenetic calcium indicator enables in vivo functional imaging with near-infrared light

Genetically encoded fluorescent calcium indicators have revolutionized neuroscience and other biological fields by allowing cellular-resolution recording of physiology during behavior. However, we currently lack bright, genetically targetable indicators in the near infrared that can be used in animals. Here, we describe WHaloCaMP, a modular chemigenetic calcium indicator built from bright dye-ligands and protein sensor domains that can be genetically targeted to specific cell populations. Fluorescence change in WHaloCaMP results from reversible quenching of the bound dye via a strategically placed tryptophan. WHaloCaMP is compatible with rhodamine dye-ligands that fluoresce from green to near-infrared, including several dye-ligands that efficiently label the central nervous system in animals. When bound to a near-infrared dye-ligand, WHaloCaMP1a is more than twice as bright as jGCaMP8s, and shows a 7x increase in fluorescence intensity and a 2.1 ns increase in fluorescence lifetime upon calcium binding. We use WHaloCaMP1a with near-infrared fluorescence emission to image Ca2+ responses in flies and mice, to perform three-color multiplexed functional imaging of hundreds of neurons and astrocytes in zebrafish larvae, and to quantitate calcium concentration using fluorescence lifetime imaging microscopy (FLIM).

neuroscience↗

ARS2-directed alternative splicing mediates CD28 driven T cell glycolysis and effector function

CD8 T cell activation prompts extensive transcriptome remodeling underlying effector differentiation and function. Regulation of transcriptome composition by the mitogen-inducible nuclear cap-binding complex (CBC) adaptor protein ARS2 has critical cell type-specific consequences, including thymic T cell survival. Here we show that ARS2 was upregulated by CD28 during activation of peripheral T cells, was essential for anti-tumor immunity, and facilitated T cell activation-induced alternative splicing. The novel splicing function of ARS2 was mediated at least in part by recruitment of splicing factors to nascent transcripts including the M2 isoform of pyruvate kinase (Pkm2), a key determinant of CD8 T cell effector properties. Notably, ARS2-directed Pkm2 splicing occurred days after stimulation of PI3K-indepdendent CD28 signaling and increased glycolysis beyond levels determined by PI3K signaling during T cell priming. Thus, ARS2-directed Pkm2 splicing represents a mechanism by which CD28 drives glycolytic metabolism, allowing for optimal effector cytokine production and T cell anti-tumor immunity.

immunology↗