American Journal of Pathology最新文献

Under diabetic conditions, hyperglycemia significantly disrupts oxygen metabolism, leading to widespread retinal hypoxia that affects all retinal cell types. The human retina is structurally complex, comprising multiple layers of metabolically active cells. Diabetic retinas are especially vulnerable to tissue oxygen pressure fluctuations, making them more susceptible to hypoxia-related damage. We have found that diabetic retinas experience hyperglycemia induced retinal hypoxia. Early detection of retinal hypoxia could improve outcomes in diabetic retinopathy (DR) and help prevent irreversible vision loss. However, conventional imaging tools such as optical coherence tomography and fluorescein angiography lack the sensitivity to detect hypoxic changes before permanent irreparable damage occurs. This review explores emerging technologies aimed at detecting (i) retinal hypoxia, and also (ii) vascular oxygenation, as two separate imaging objectives. It highlights Dr. Robert Linsenmeier's pioneering work using invasive microelectrodes to map oxygen distribution across retinal layers and focuses on the development of HYPOX-4, a novel, highly sensitive molecular imaging probe for detecting hypoxia in the living diabetic retinas. Additionally, this review provides an overview of other emerging technologies for imaging oxygenation in the diabetic retina, including retinal oximetry, phosphorescence lifetime imaging, functional MRI and photoacoustic imaging, which may collectively enhance our understanding and management of DR.

Organotypic retinal explant cultures are a valuable experimental tool for investigating neuroretinal diseases and advancing therapeutic strategies. Ex vivo methods preserve the natural architecture and intercellular interactions of the retina while enabling precise manipulations of the microenvironment, a distinct advantage over traditional in vitro two-dimensional cell models. Compared with in vivo animal and human studies, retinal explants offer ethical and cost-effective advantages, serving as bridge models for both animal to human and preclinical to clinical studies. This review explores the application of retinal explants in retinal disease research, covering emerging technologies, specific neurodegenerative diseases, human explants, and future directions. Technologies including gene therapy, electrophysiology, live imaging, stem cell transplantation, nanoparticle delivery, optogenetics, and artificial intelligence exhibit ready integrated into explant models and rapid advancement. Although retinal explants do not replicate the full systemic context of the eye, they represent powerful localized models for efficient study of retinal physiology and pathophysiology. With these advantages, retinal explants can be used as a translational platform capable of accelerating the development and validation of retinal therapies.

Metastasis is a major threat in breast cancer, often involving lymph node (LN) dissemination. However, the cellular composition and signaling networks within the metastatic microenvironment remain incompletely characterized, resulting in limited understanding of the molecular mechanisms driving LN metastasis. In this study, a comprehensive single-cell atlas of metastatic niches was constructed using single-cell RNA-sequencing data from 78 primary breast tumors and their paired LN metastatic samples. Among the epithelial cell subpopulations, distinct clusters representing early-disseminated cancer cells were identified. Notably, profound metabolic reprogramming and immune modulation was observed during the malignant transformation of epithelial cells, which may contribute to the invasive and metastatic phenotype of early-disseminated cancer cells. Furthermore, the communication network within the metastatic microenvironment has also been delineated systematically, where crosstalk among lymphocyte, macrophage, and epithelial cells drove immunosuppressive features of LN metastasis. To explore potential therapeutic interventions, computational drug repositioning was conducted and four tyrosine kinase receptor inhibitors were identified that may target key interactions within this crosstalk. These results were validated using spatial transcriptomics data of four metastatic LN tissue sections from an integrated single-cell RNA-sequencing cohort. Collectively, this study discussed the cellular architecture and regulatory interplay underlying LN metastasis in breast cancer, offering novel insights that may inform targeted therapeutic strategies for patients with metastatic disease.

Cellular heterogeneity plays a critical role in tissues and diseases, including cancer. Single-cell technologies are required to provide detailed information about the phenotype and genotype of individual cells. Despite several approaches to analyzing different analytes at the single-cell level, it is challenging to assess DNA, RNA, and protein simultaneously. Here, a single-cell triomics method to assess DNA, RNA, and proteins from the same cell using a targeted sequencing approach is shown. Breast cancer cells cultured in monolayers and in patient-derived scaffolds that mimic in vivo-like growth conditions, both with and without chemotherapy treatment, were analyzed. Data showed that DNA, RNA, and protein biomarkers could be reliably analyzed, providing biological insights into breast cancer cell heterogeneity. In addition, chemotherapy treatment caused changes in subpopulations and expressions of biomarkers. Furthermore, cells growing in patient-derived scaffolds generated from various breast cancers affected cell heterogeneity and drug resistance differently as a result of the unique tumor-specific microenvironments. The data show that single-cell triomics provides new means to assess cancer cell heterogeneity at DNA, RNA, and protein levels.

Acute pancreatitis (AP) is a common, potentially severe inflammatory disease of the pancreas. Although environmental triggers such as alcohol and gallstones are well known, only a subset of exposed individuals develop AP, suggesting that genetic or intrinsic factors contribute to disease onset and severity. Endoplasmic reticulum (ER) stress has emerged as a key pathogenic mechanism in AP due to the essential role of the ER in protein synthesis, folding, and degradation (proteostasis). Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an ER stress-inducible protein highly expressed in the pancreas and critical for proteostasis, but its role in AP remains unclear. To investigate this, pancreas-specific Manf knockout mice were generated using the Cre/loxP system and subjected them to caerulein- or alcohol-induced AP. In both models, MANF deficiency worsened pancreatic injury, as evidenced by elevated ER stress markers [phosphorylated eukaryotic initiation factor 2 alpha (p-eIF2α) and glucose-regulated protein 78 (GRP78)], apoptosis (cleaved caspase-3), inflammation (IL-6 and tumor necrosis factor α), regeneration (Ki67), and elevated pancreatic lipase levels. In the caerulein model, male Manf knockout mice exhibited higher oxidative stress and macrophage infiltration than female mice. In the alcohol model, both sexes showed increased inflammation and macrophage infiltration, but oxidative stress and high mobility group box 1 expression were again more prominent in male mice. These findings suggest that MANF contributes to pancreatic resilience under stress conditions and may influence sex-dependent responses during AP.

Hematopoietic stem cell (HSC) aging leads to hematological dysfunction and diseases, but the regulatory factors involved remain incompletely characterized. In this study, the HSC Aging-Associated TFs Catalog System model was developed to identify transcription factors (TFs) that resist HSC aging. This approach revealed RORA as a key aging-negative-associated TF. Rora deletion in HSCs caused aged phenomes and functionally impaired their reconstitutive capacity. Additionally, Rora deficiency impaired leukemia stem cell proliferation and prevented chronic myelogenous leukemia. These findings establish RORA as a critical regulator in maintaining HSC function and provide insights into its therapeutic potential in hematological disorders.