Publications by authors named "Alex Chen"

Abnormal valve development is the most common congenital heart malformation. The transcription factor Sox7 plays a critical role in the development of vascular and cardiac septation. However, it remains unclear whether Sox7 is required for heart valve development.

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Immune checkpoint inhibitors (ICI) have become integral to treatment of non-small cell lung cancer (NSCLC). However, reliable biomarkers predictive of immunotherapy efficacy are limited. Here, we introduce HistoTME, a novel weakly supervised deep learning approach to infer the tumor microenvironment (TME) composition directly from histopathology images of NSCLC patients.

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Transient exposure to ketamine can trigger lasting changes in behavior and mood. We found that brief ketamine exposure causes long-term suppression of futility-induced passivity in larval zebrafish, reversing the "giving-up" response that normally occurs when swimming fails to cause forward movement. Whole-brain imaging revealed that ketamine hyperactivates the norepinephrine-astroglia circuit responsible for passivity.

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T cell immune tolerance is established in part through the activity of the Auto-immune Regulator (AIRE) transcription factor in the medullary Thymic Epithelial Cells (mTEC) of the thymus. AIRE induces expression of SELF peripheral tissue-specific antigens for presentation to naïve T cells to promote activation/deletion of potentially autoreactive T cells. We show, for the first time to our knowledge, that tumors mimic the role of AIRE in mTEC to evade immune rejection.

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Purpose: To develop and evaluate a multimodal approach including clinical parameters and biparametric MRI-based artificial intelligence (AI) model for determining the necessity of prostate biopsy in patients with PI-RADS 3 lesions.

Methods: This retrospective study included a prospectively recruited patient cohort with PI-RADS 3 lesions who underwent prostate MRI and MRI/US fusion-guided biopsy between April 2019 and February 2024 in a single institution. The study examined demographic data, PSA and PSA density (PSAD) levels, prostate volumes, prospective PI-RADS v2.

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Article Synopsis
  • - Regulatory CD8 T cells (CD8 Treg) usually help control harmful CD4 T cells, but in autoimmune diseases, they often fail, partly due to inhibitory receptors that limit their activation.
  • - A new bispecific antibody called MTX-101 targets these inhibitory receptors and CD8 T cells to enhance the ability of CD8 Treg to eliminate pathogenic CD4 T cells in various experimental models.
  • - In studies, MTX-101 improved CD8 Treg activity, reduced harmful CD4 T cell expansion, and protected tissues from damage without triggering excessive inflammation, showing promise for treating autoimmune disorders.
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Macrophages represent an important viral reservoir in HIV-1-infected individuals. Different from T cells, HIV-1 assembly in macrophages occurs at intracellular compartments termed virus-containing compartments (VCCs). Our previous research in HeLa cells - in which assembly resembles that found in infected T cells - suggested that late endosomes/lysosomes (LELs) play a role in HIV-1 trafficking towards its assembly sites.

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Abdominal aortic aneurysm (AAA) is a life-threatening condition, but effective medications to prevent its progression and rupture are currently lacking. The nuclear receptor pregnane-X-receptor (PXR) plays a crucial role in vascular homeostasis. However, the role of PXR in AAA development remains unknown.

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  • Pulmonary hypertension (PH) is a severe disease linked to damage in blood vessels of the lungs and involves the degradation of important proteins, such as BMPR2, by the enzyme cathepsin L, leading to cell death through a process called pyroptosis.
  • Research showed that cathepsin L levels are significantly higher in patients with pulmonary arterial hypertension, and its inhibition in animal models of PH improved conditions related to the disease, including reduced pressure in the heart and enhanced blood vessel health.
  • The study concludes that cathepsin L contributes to the progression of PH by degrading BMPR2, which triggers a cascade leading to programmed cell death in endothelial cells, highlighting a potential therapeutic target for treating PH.
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Prostate cancer is one of the most prevalent malignancies in the world. While deep learning has potential to further improve computer-aided prostate cancer detection on MRI, its efficacy hinges on the exhaustive curation of manually annotated images. We propose a novel methodology of semisupervised learning (SSL) guided by automatically extracted clinical information, specifically the lesion locations in radiology reports, allowing for use of unannotated images to reduce the annotation burden.

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PD-1 is a key negative regulator of CD8 T cell activation and is highly expressed by exhausted T cells in cancer and chronic viral infection. Although PD-1 blockade can improve viral and tumor control, physiological PD-1 expression prevents immunopathology and improves memory formation. The mechanisms driving high PD-1 expression in exhaustion are not well understood and could be critical to disentangling its beneficial and detrimental effects.

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Aging is one of the biggest risk factors for cancer development. More than 85% of all cancers occur in individuals above 55 years old, often accompanied by age-associated immune defects. Previous studies on the tumor microenvironment during aging have identified several factors, such as the roles of fibroblasts, immunosuppression, and metastasis.

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  • Diabetic neuropathic pain (DNP) is a common complication of diabetes, causing significant pain and suffering in patients, particularly in the distal limbs.
  • A study comparing serum metabolite levels revealed that branched-chain amino acids (BCAA) are significantly lower in DNP patients compared to those with type 2 diabetes but without neuropathy.
  • Research in mouse models showed that BCAA deficiency leads to increased expression of L-type amino acid transporter 1 (LAT1), which disrupts potassium channel functioning and enhances neuronal excitability, leading to DNP symptoms; BCAA supplementation or LAT1 inhibition can alleviate these symptoms.
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Article Synopsis
  • - Both neurons and glia use neuromodulatory substances to communicate, but how they compute information in these networks is not fully understood.
  • - In larval zebrafish, norepinephrine causes quick excitation followed by delayed behavior inhibition, which is partially mediated by astroglial release of ATP that converts to adenosine to suppress behavior.
  • - This study, along with another involving mice, highlights the important role of astroglial purinergic signaling in regulating behavior and brain activity transitions driven by norepinephrine, showcasing a conserved mechanism across species.
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Purpose: To evaluate the intra-fractional tumor motion in lung stereotactic body radiotherapy (SBRT) with deep inspiration breath-hold (DIBH), and to investigate the adequacy of the current planning target volume (PTV) margins.

Methods: Twenty-eight lung SBRT patients with DIBH were selected in this study. Among the lesions, twenty-three were at right or left lower lobe, two at right middle lobe, and three at right or left upper lobe.

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Article Synopsis
  • The text discusses the increasing importance of optical recording for studying molecular dynamics in biology, aided by advancements in biosensors and microscopy.* -
  • It introduces AQuA2, a new data analysis platform powered by machine learning, designed to accurately and efficiently analyze complex data from live imaging.* -
  • AQuA2 enables the identification of molecular activities and functional units, with applications demonstrated in various biological contexts, such as studying neuron and astroglia interactions and signal patterns in mouse spinal cords.*
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Cardiac dysfunction, an early complication of endotoxemia, is the major cause of death in intensive care units. No specific therapy is available at present for this cardiac dysfunction. Here, we show that the N-terminal gasdermin D (GSDMD-N) initiates mitochondrial apoptotic pore and cardiac dysfunction by directly interacting with cardiolipin oxidized by complex II-generated reactive oxygen species (ROS) during endotoxemia.

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Background: Familial hypertrophic cardiomyopathy has severe clinical complications of heart failure, arrhythmia, and sudden cardiac death. Heterozygous single nucleotide variants (SNVs) of sarcomere genes such as are the leading cause of this type of disease. CRISPR-Cas13 (clustered regularly interspaced short palindromic repeats and their associated protein 13) is an emerging gene therapy approach for treating genetic disorders, but its therapeutic potential in genetic cardiomyopathy remains unexplored.

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The etiology and effect of age-related immune dysfunction in cancer is not completely understood. Here we show that limited priming of CD8 T cells in the aged tumor microenvironment (TME) outweighs cell-intrinsic defects in limiting tumor control. Increased tumor growth in aging is associated with reduced CD8 T cell infiltration and function.

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Objective: To report a novel anatomical pattern of autoimmune encephalitis characterized by strictly unilateral cortical inflammation and a clinical picture overlapping with late-onset Rasmussen's encephalitis.

Methods: We retrospectively gathered data of patients identified at two tertiary referral academic centers who met inclusion criteria.

Results: We identified twelve cases (average age 65, +/- 19.

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Chronic inflammatory and immune responses play key roles in the development and progression of chronic obstructive pulmonary disease (COPD). PANoptosis, as a unique inflammatory cell death modality, is involved in the pathogenesis of many inflammatory diseases. We aim to identify critical PANoptosis-related biomarkers and explore their potential effects on respiratory tract diseases and immune infiltration landscapes in COPD.

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Objectives: Sepsis is a life-threatening infectious disease in which an immune inflammatory response is triggered. The potential effect of ferroptosis-related genes (FRGs) in inflammation of sepsis remained unclear. We focused on identifying and validating core FRGs and their association with immune infiltration in blood from currently all patients with sepsis.

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The efficacy of extracranial-intracranial (EC-IC) bypass in preventing ischemic stroke progression and recurrence is controversial. As per the current hypothesis, EC-IC bypass is most beneficial for patients with persistent hemodynamic insufficiency. Hence, various approaches have been used to evaluate hemodynamic insufficiency, including repeated single photon emission CT (SPECT) imaging or continuous monitoring of cerebral flow with transcranial Doppler ultrasound (TCD).

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