Search Results (1,700)

Regulated cardiomyocyte death is a central contributor to myocardial infarction (MI)-associated injury. Mixed lineage kinase domain-like protein (MLKL), a key effector of necroptosis, has been implicated in cardiovascular disease; however, its role in MI remains incompletely defined. MLKL expression was evaluated in hypoxia-treated cardiomyocytes, infarcted murine hearts, and human cardiac tissue. MLKL function was investigated using siRNA-mediated knockdown in neonatal mouse cardiomyocytes and genetic deletion in mice subjected to left anterior descending (LAD) coronary artery ligation. Apoptosis- and pyroptosis-related signaling were assessed by immunoblotting and immunostaining. RIP3 expression and regulation were examined at both protein and mRNA levels, and the RIP3 inhibitor GSK’872 was used to assess pathway dependence. MLKL expression was increased in hypoxic cardiomyocytes, infarcted mouse hearts, and human failing cardiac tissue. Unexpectedly, MLKL deficiency was associated with aggravated myocardial injury, impaired cardiac function, and increased fibrosis following MI. Mechanistically, MLKL deficiency was associated with increased RIP3 protein abundance without a corresponding increase in RIP3 mRNA, consistent with post-transcriptional regulation. Further analyses indicated that MLKL deficiency reduced RIP3 ubiquitination and impaired proteasome-mediated degradation, resulting in RIP3 stabilization. Elevated RIP3 levels were accompanied by increased expression of apoptosis- and pyroptosis-related proteins, particularly at early time points after MI. Pharmacological inhibition of RIP3 with GSK’872 was associated with reduced apoptosis- and pyroptosis-related signaling and improved cardiac function. MLKL deficiency is associated with stabilization of RIP3 and enhanced activation of apoptosis- and pyroptosis-related signaling following MI, contributing to aggravated myocardial injury. These findings support a regulatory role for the MLKL–RIP3 axis in cardiomyocyte death and suggest that targeting RIP3 may represent a potential therapeutic strategy in myocardial infarction. Full article

Mammals and reptiles possess a metanephric kidney as the terminal renal organ for homeostasis of solutes and waste products. The development of the metanephric kidney has primarily been studied in mammalian model systems. Little is known about the conservation of metanephric kidney formation in non-mammalian species such as reptiles. Uniquely, reptiles maintain kidney progenitor cell populations throughout life and continually develop new nephrons, the functional unit of the kidney. The red-eared slider turtle, Trachemys scripta elegans, was utilized to investigate the conservation of reptilian metanephric kidney development. The nephron progenitor cell (NPC) marker, Six2, was detected in whole-mount turtle kidneys in a similar pattern to mammals. However, there were differences in progenitor cell niche morphology where turtle NPC populations formed distinct elongated rows instead of the rosette-like morphology found in the mouse. The pattern of NPC populations in the embryonic turtle kidney was maintained in the adult turtle. Whole-genome bisulfite sequencing was performed on cortical tissue containing the NPC populations from adult turtle kidneys and compared to those of adult mice. Significant conservation of gene methylation was detected in adult cortical tissue between the two species, although unique signatures were detected in turtle samples related to DNA repair and β-catenin signaling. This suggests a high level of conservation of metanephric kidney development at the genetic level. Full article

Dengue fever (DF) is an acute mosquito-borne infectious disease caused by dengue virus (DENV), primarily transmitted by Aedes aegypti and Aedes albopictus. Nearly 4 billion people worldwide are at risk of infection, and the 2024 epidemic reached an unprecedented scale. Severe cases can lead to hemorrhage, shock, and even death, prompting the WHO to classify it as a potential pandemic pathogen. Current prevention and control measures face prominent bottlenecks, including limited applicable populations for vaccines, lack of specific antiviral drugs, and increasing insecticide resistance in mosquito vectors. Notably, susceptible animal models serve as core tools for elucidating the pathogenic mechanisms of dengue virus, screening antiviral drugs, and evaluating vaccine protective efficacy, holding irreplaceable significance. This review systematically summarizes the characteristics, application scenarios, and research progress of mainstream and potential susceptible animal models, including non-human primates, mice, pigs, tree shrews, and bats. It covers model systems with different immune statuses, genetically modified types, and species-specific traits. Among these, mouse models are the most widely used due to their high flexibility and controllable cost, while non-human primate models have become key carriers for preclinical vaccine evaluation by virtue of their high homology with human immune responses. However, current models generally suffer from core bottlenecks, such as incomplete simulation of core severe phenotypes, insufficient restoration of immune mechanisms, unclear viral receptor mechanisms, and lack of unified standards for inoculation doses and evaluation indicators. These limitations make it difficult to accurately replicate key severe disease mechanisms, including antibody-dependent enhancement (ADE) and cytokine storms. Future model development should focus on core requirements—including intact immunity, broad-spectrum susceptibility, and accurate simulation of clinical pathological features—prioritize solving the simulation challenges of ADE and cytokine storms, and establish standardized experimental systems and evaluation criteria. By comprehensively summarizing the advantages and limitations of the existing models, this review provides a systematic reference for the optimization and upgrading of dengue virus-susceptible animal models. It also holds important guiding significance for promoting the in-depth development of basic dengue research, innovation in prevention and control technologies, and clinical transformation and application. Full article

Tumor initiation and metastatic progression are driven by context-dependent genetic alterations that disrupt tumor suppressor pathways, metabolic homeostasis, and signaling networks. However, the initial drivers that transform normal cells into malignant ones and their context dependency remain elusive. To address this, we aimed to systematically identify and characterize these drivers across cancer types, species, and microenvironments. We constructed customized clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) knockout (KO) libraries targeting high-frequency mutated and downregulated genes associated with liver hepatocellular carcinoma (LIHC) and breast carcinoma (BRCA) and conducted parallel functional screens in non-cancerous mouse and human fibroblast cell lines under two-dimensional (2D), three-dimensional (3D), and in vivo conditions. Strikingly, TP53 and NF1 emerged as pan-context drivers consistently enriched across immortalization, tumorigenesis, and metastasis in both LIHC and BRCA settings, while most other identified drivers were largely species-, tissue-, and microenvironment-specific with limited cross-model overlap. Despite this heterogeneity, all drivers converge on core pathways including epigenetic regulation, metabolic reprogramming, and growth factor signaling. Unlike prior studies on established cancer cells, this work defines the genetic barriers restricting the malignant transformation of primary normal cells, offering a new framework for early cancer evolution. Full article

Hydroxyurea (HU) is a ribonucleotide reductase inhibitor widely used for the treatment of sickle cell disease and myeloproliferative disorders, yet a precise nitric oxide (NO) synthase (NOS)-dependent mechanism remains incompletely defined. The role of NOS3 in HU-mediated proliferation, cell cycle, and apoptosis was analyzed in HEL92.1.7 erythroleukemic cells and primary mouse erythroid progenitors upon genetic knockdown/knockout and pharmacological NOS2/NOS3 inhibition. NOS3 expression, phosphorylation, NO and citrulline production, and protein nitrosylation were assessed via immunoblotting and biochemical assays. Computational docking and molecular dynamics simulations were performed to examine the interaction between HU and NOS3. HU enhanced NOS3 expression and phosphorylation, leading to increased NO and citrulline production. Computational analysis predicted HU binding within the NOS3 active site, whereas functional activation was AKT1-dependent. A biotin switch assay revealed cooperative NOS2-/NOS3-mediated protein nitrosylation under HU treatment. NOS3 depletion or inhibition abrogated HU-induced S-phase accumulation and restored cell proliferation. NOS3 protein depletion increased late apoptosis in erythroleukemic cells, while in murine erythroid cells, both Nos3 deficiency and inhibition decreased early and increased late apoptosis. NOS2 and NOS3 act as complementary mediators of proliferation and apoptosis, with NOS3 playing a distinct role in HU-induced proliferation arrest in erythroid cells. These findings highlight the therapeutic potential of NOS targeting to enhance the efficacy of HU and overcome resistance in hematologic malignancies. Full article

The conversion of primed pluripotent stem cells to a naive-like state has emerged as a critical strategy for enhancing developmental potential and broadening applications in regenerative medicine. Conditioned media (CM)-based approaches provide a supportive microenvironment enriched with secreted factors that may facilitate this state transition without extensive genetic or chemical manipulation. In this study, we investigated the potential of human Wharton’s Jelly-derived mesenchymal stem cell-conditioned media (hWJ-MSCs-CM) and mouse embryonic fibroblasts CM (MEFs-CM) to support the conversion of primed rhesus monkey embryonic stem cells (rhESCs) into a naive-like state. The rhESCs were cultured under feeder-free and feeder conditions using both hWJ-MSCs-CM and MEFs-CM, exhibiting distinct morphological changes during conversion. Immunofluorescence analysis demonstrated the expression of pluripotency and naive markers under both conditions. Gene expression analysis further confirmed the upregulation of naive-specific genes and downregulation of primed markers, with statistically significant differences between groups. Additionally, epigenetic reprogramming was assessed, revealing differential effects of the CM sources on the reversion to a naive state. These findings highlight the potential of hWJ-MSCs-CM as a supportive system for naive-like state induction in primate ESCs. Full article

Pneumocystis is a respiratory fungal pathogen that causes life-threatening pneumonia in immunocompromised patients. While Pneumocystis can colonize healthy hosts by resisting and transiently evading innate immunity, a functional adaptive immune response is essential to prevent progressive infection. Impairments in adaptive immunity, particularly defects in CD4⁺ T cell function, are strongly associated with the development of severe Pneumocystis pneumonia (PCP) in humans and a wide range of mammalian species. Immune activation by Pneumocystis has strong genetic determinants, and a major gap in our understanding of PCP pathogenesis lies in uncovering the mechanisms by which Pneumocystis escapes alveolar macrophages and evades pulmonary innate immunity. Prior research determined that FVB/NJ mice display an unusual resistance to Pneumocystis infection. Further susceptibility testing across several inbred mouse strains revealed that the AKR/J strain, which is phylogenetically distant from the FVB/NJ strain, also exhibits a rarely described form of protective innate immunity against PCP. Notably, the mechanism of AKR/J resistance does not require CD4⁺ or CD8⁺ T lymphocytes. However, depleting alveolar macrophages prior to infection rendered AKR/J mice susceptible to PCP, highlighting the critical role of macrophages for this protective innate immune response. These novel findings establish the AKR/J inbred strain as a valuable model for investigating the interaction between Pneumocystis and macrophages, offering a unique opportunity to explore how these interactions lead to differential outcomes between resistant and susceptible mouse strains. Additionally, it may offer key insights into the mechanisms by which Pneumocystis evades macrophage-mediated innate immunity in the majority of mammalian hosts, including humans. Full article

Aging and stress-related factors affect sperm DNA methylation in regions associated with genes responsible for embryonic development. The stochastic epigenetic variation hypothesis holds potential to explain these patterns, proposing that, in response to stressors, naturally variable methylation regions (VMRs) associated with morphogenetic genes exhibit increased methylation variation to diversify phenotypes and improve the chances of survival of the genetic lineage. Here, we test predictions from this hypothesis using mouse and rat sperm DNA methylation data from publicly available sources. Specifically, we identify VMRs and analyze their overlap with regions differentially methylated (DMRs) in response to aging, stressors, and with various genomic elements. We demonstrate that the nature of the DNA regions, rather than the nature of the stressor, determines the response of the sperm methylome to aging and stress, and propose a model that explains shifts in methylation within VMRs through stochastic changes, whereby initially hypermethylated regions lose methylation and initially hypomethylated regions gain methylation. VMRs are depleted of open chromatin regions and histones in male germ cells and are enriched for a binding motif for ZFP42, an epigenetic remodeler. This knowledge may open opportunities for the development of interventions to control epigenetic information transfer via germ cells. Full article

Hyperuricemia is associated with liver dysfunction, yet its molecular mechanisms remain unclear. This study investigated high uric acid (HUA)-induced hepatocyte injury using a hyperuricemia mouse model (HUM) and uric acid (UA)-treated L02 cells. HUM exhibited elevated aspartate aminotransferase (AST)/alanine aminotransferase (ALT) and pathological liver changes. Transmission electron microscopy (TEM) confirmed ferroptotic hallmarks, including mitochondrial shrinkage and increased membrane density. UA exposure upregulated NADPH oxidase 4 (NOX4), increased reactive oxygen species (ROS), and promoted lipid peroxidation (LPO), accompanied by intracellular Fe²⁺ accumulation. Mechanistically, UA increased hypoxia-inducible factor-2α (HIF-2α) expression, subsequently upregulating iron transporters divalent metal transporter 1 (DMT1) and transferrin receptor (TFRC). Deferoxamine (DFO) treatment effectively reversed Fe²⁺ overload and alleviated oxidative stress. Notably, pharmacological inhibition or genetic knockdown of HIF-2α specifically suppressed DMT1 upregulation and restored iron homeostasis, while TFRC expression remained unaffected. Blocking the HIF-2α/DMT1 axis significantly reduced LPO and mitochondrial dysfunction. These findings demonstrate that HUA induces hepatocyte ferroptosis through HIF-2α-mediated DMT1 upregulation, leading to Fe²⁺ overload and mitochondrial impairment. This study identifies the HIF-2α/DMT1 pathway as a key driver of HUA-induced liver injury and a potential therapeutic target. Full article

Background/Objectives: Heterotopic ossification (HO), the aberrant formation of bone within soft tissues, arises either from rare genetic mutations or more commonly from traumatic insults. It is a major cause of morbidity not only in individuals harboring causative mutations, but also in those undergoing musculoskeletal surgery or trauma and in soldiers sustaining blast or burn injuries. Bone morphogenetic protein (BMP) signaling is a central driver of both hereditary and acquired forms of HO. Primary cilia are nonmotile, antenna-like organelles that extend from the cell surface and serve as crucial sensory and signaling hubs by concentrating key pathway components within a confined volume at the ciliary tip. However, their functional role in the pathogenesis of traumatic HO remains poorly understood. Methods: We investigate the role of primary cilia in traumatic HO using a genetically modified mouse model and cellular model. Results: We demonstrate that BMP signaling is attenuated when primary cilia function is disrupted. Both ciliation frequency and ciliary length were reduced in Scleraxis-CreERT2; Intraflagellar transport 88 ^{floxed/floxed} (Scx-CreERT2;Ift88^fl/fl) tenocytes. Deletion of Ift88 effectively suppressed pathological BMP signaling and inhibited HO formation. Conclusions: These findings establish that functional primary cilia are required for traumatic HO development and highlight ciliary regulation as a potential therapeutic avenue for preventing or mitigating post-traumatic HO. Full article

Background/Objectives: Congenital anomalies of the kidney and urinary tract (CAKUTs) represent the leading cause of pediatric chronic kidney disease, yet the molecular mechanisms underlying these malformations remain incompletely understood. While genetic studies have identified numerous CAKUT-associated genes, conventional knockout approaches often result in embryonic lethality or fail to reveal tissue-specific gene functions. This review aims to synthesize findings from conditional knockout mouse studies that have elucidated the spatiotemporal requirements of key signaling pathways during kidney development. Methods: We conducted a narrative synthesis of studies employing Cre-loxP conditional gene targeting in mouse models, identified through systematic searches of PubMed and cross-referencing of key primary research. Studies were selected based on their use of lineage-specific Cre drivers (Six2-Cre, Hoxb7-Cre, Foxd1-Cre) to investigate nephron progenitor maintenance, ureteric bud branching morphogenesis, and stromal–epithelial interactions. Results: Conditional knockout studies have redefined CAKUT pathogenesis as a disorder of dose-dependent signaling, temporal regulation, and inter-compartmental communication. WNT/β-catenin signaling operates in a biphasic, dose-dependent manner in nephron progenitors, with Six2-Cre-mediated β-catenin deletion causing premature progenitor depletion. BMP and FGF pathways demonstrate dose-dependent and context-specific functions in progenitor maintenance, while GDNF/RET signaling is essential for ureteric bud outgrowth and branching. Importantly, stromal-specific deletions have uncovered non-cell-autonomous mechanisms regulating nephron formation. Haploinsufficiency studies demonstrate that partial pathway disruption can reduce nephron endowment without overt CAKUT, predisposing to adult-onset hypertension and chronic kidney disease. Conclusions: Conditional gene targeting has mechanistically redefined CAKUT from a collection of structural malformations to a spectrum of disorders arising from quantitative perturbations in lineage-specific signaling networks. These findings establish that phenotypic severity is determined by the degree of pathway disruption, the developmental timing of insult, and the compartment affected, providing a framework for interpreting oligogenic interactions and variable penetrance in human CAKUTs. Full article

Inflammatory bowel disease (IBD) is triggered by genetic predisposition and chronic inflammation, with aberrant activation of the innate immune complex NLRP3 inflammasome playing a pivotal role in its pathogenesis. In this study, we investigated the effects of a hot water extract from the brown alga Endarachne binghamiae (EB-WE) on the inhibition of NLRP3 inflammasome activation, with a focus on its antioxidant properties, in various inflammation models. In bone marrow-derived macrophages (BMDMs), NLRP3 inflammasome activation was induced using LPS and ATP, and EB-WE pretreatment (100, 200 µg/mL) significantly reduced the secretion of IL-1β and IL-18. Confocal immunofluorescence analysis further confirmed that EB-WE suppressed the formation of the NLRP3-ASC/caspase-1 complex. Furthermore, the in vivo anti-IBD efficacy of EB-WE was assessed using a DSS-induced mouse model, in which colonic inflammation and NLRP3-mediated responses were prominent. Oral administration of EB-WE (2 or 5 mg/day) markedly ameliorated clinical symptoms, such as weight loss, diarrhea, and rectal bleeding, and significantly reduced the disease activity index (DAI). EB-WE also decreased serum pro-inflammatory cytokine levels and the expression of NLRP3 inflammasome-related molecules in colon tissue at both the gene and protein levels. In both BMDMs and the IBD mouse model, we further analyzed the upstream regulatory pathway involving NOX2-iNOS. EB-WE efficiently inhibited the activation of the NOX-iNOS axis and NF-κB phosphorylation, thereby alleviating inflammasome activation associated with DSS-induced oxidative stress and neutrophil/macrophage infiltration. Collectively, these results demonstrate that EB-WE effectively suppresses the formation and activation of the NLRP3 inflammasome by modulating the NOX-iNOS axis and the NF-κB pathway via antioxidant mechanisms. These findings suggest that EB-WE holds promise as a novel marine-derived natural therapeutic agent for the treatment of chronic inflammatory diseases. Full article

Constitutively active KRAS mutations are highly prevalent in lung cancers, but the direct role of its downstream phosphatidylinositol 3-kinase (PI3K) pathway in tumor progression remains unclear. A previous study established the requirement for PIK3CA, the alpha catalytic isoform, in lung tumor development in mouse models with an intact Trp53 tumor suppressor. In this study, we further investigated the requirement of PIK3CA for tumor growth both in vitro and in vivo. We first generated a “KPA” cell line by genetically deleting Pik3ca from a murine lung adenocarcinoma “KP” cell line harboring oncogenic Kras^G12D and lacking Trp53. We also examined the requirement for STK11, a tumor suppressor and metabolic regulator frequently co-mutated with KRAS in lung cancer. We found that Pik3ca is not required for cell survival and growth in vitro, even under anchorage-independent conditions, but reduced the growth rate by 15%. We next orthotopically implanted KP and KPA cells into syngeneic mice and found that PIK3CA is absolutely required for tumor progression, even in the absence of Trp53. Implantation of KP cells, or a “KPS” cell line lacking the Stk11 gene, led to rapid tumor growth and death of all host animals. In contrast, mice implanted with KPA cells all survived with no detectable lung tumors. The gene expression profiles from cultured cell lines suggest oxidative stress as a potential vulnerability of KPA cells. Indeed, we found KPA cells were more sensitive to hydrogen peroxide and diethyl maleate-induced oxidative stress as compared to KP and KPS cells. Together, these results indicate that PIK3CA is not required for lung cancer cell growth induced by mutant KRAS in vitro but is essential for in vivo progression and growth. Full article

Swine influenza virus (SIV) continues to evolve and possesses notable zoonotic potential, making it an important respiratory pathogen of concern for both the global swine industry and public health. Owing to antigenic drift, genetic reassortment, and regional lineage diversity, vaccine efficacy against SIV shows marked variability across different epidemiological contexts. Therefore, establishing appropriate animal models to dissect its pathogenic mechanisms, transmission characteristics, and immune response patterns is of critical importance. This review systematically summarises the animal models commonly used in SIV research, including mice, ferrets, guinea pigs, pigs, and non-human primates, and provides an integrated analysis across three core dimensions: pathological manifestations, viral replication kinetics, and immune architecture. The evidence indicates that substantial inter-model differences exist in pulmonary lesion distribution, transmission efficiency, mucosal immune development, and cellular immune complexity, which in turn define their functional roles in mechanistic studies, transmission research, and vaccine evaluation. Building on this framework, this review further emphasises the value of a tiered, multi-model strategy in SIV research. In vitro systems and mouse models are well suited for early mechanistic exploration and preliminary vaccine screening; ferret and guinea pig models facilitate the evaluation of transmission dynamics; and the pig model, as the natural host system, remains the critical platform for confirming protective efficacy, identifying potential immunopathological risks, and assessing translational relevance. Importantly, the potential occurrence of vaccine-associated enhanced respiratory disease under antigen-mismatched conditions highlights the need to evaluate both protective performance and immunological safety during vaccine development. Overall, rational integration of evidence across multiple models, anchored to the natural host, will improve the predictability and translational reliability of SIV vaccine research. Full article

Autism Spectrum Disorder (ASD) is a developmental disorder that manifests a broad variability of phenotypes. The underlying factors contributing to the diverse presentation of autistic phenotypes remain poorly understood. Studies have shown that environmental and genetic factors could contribute to ASD. Additionally, there is a sex bias in the disorder, where the prevalence in males is higher than in females. But it is still unknown how exposure to similar risk factors can lead to different phenotypes. The three-hit theory states that the vulnerability of an individual to develop ASD is modulated by the interplay between genetic predisposition, sex, and environmental insults. To better understand this phenomenon, we investigated whether an environmental insult, via maternal immune activation (MIA) during pregnancy could influence the development of the autistic-like phenotype in a genetically predisposed mouse strain, contactin-associated protein-like 2 (CNTNAP2) knockout. CNTNAP2 knockout, sex, and maternal immune activation had significantly additive effects on repetitive/stereotyped and social behavior in the offspring, while working memory and sensory gating were not affected by hits. These results indicate that genetics, sex, and environment interact to influence autistic-like phenotypes in a behavior-specific manner. Full article