Search Results (68)

The aim of the study was to define radiobiological effects of single and fractionated low doses in normal fibroblasts in 40 patients with squamous cell carcinoma of the head and neck (HNSCC) treated with induction chemotherapy combined with low-dose fractionated radiation (LDFR) and to answer the question regarding the role of low-dose hyper-radiosensitivity (HRS) in these effects. HRS status was determined using flow cytometry-based clonogenic survival assay (cells were irradiated with doses 0.1–4 Gy of 6 MV X-rays). Radiobiological effects (cell kill, kinetics of DSB recognition and repair, chemopotentiation) of LDFR 4x0.5 Gy and a single dose of 2, 0.5 and 0.2 Gy were estimated by clonogenic, pATM and γH2AX foci assays. HRS response was demonstrated for normal fibroblasts in 6 of the 40 HNSCC patients. For all assessed biological parameters, significant interindividual differences were observed. The presence of HRS had no effect on the chemopotentiating effects of LDFR 4x0.5 Gy, which were similar to that after 2 Gy. There was also no association between HRS and the maximum number of pATM and γH2AX foci induced by single (0.2, 0.5, 2 Gy) or fractionated low doses 4x0.5 Gy. Significantly higher percentages of residual pATM and γH2AX foci observed after LDFR 4x0.5 Gy than after 2 Gy were independent of HRS. HRS is a rare finding (15%) in normal fibroblasts from HNSCC patients; therefore, it is of rather little importance in healthy late-reacting connective tissues. Moreover, the fibroblast response to single and fractionated low doses (alone or in combination with carboplatin and paclitaxel) appeared more dependent on individual radiosensitivity than on HRS. Full article

Background/Objectives: DNA polymerase ε (Pol ε), encoded by POLE1, plays a pivotal role in high-fidelity DNA replication and in coordinating DNA repair. While pathogenic exonuclease-domain variants are well established in cancer, biallelic POLE1 variants remain largely unexplored in non-malignant human cells. Methods: Here, we analyzed primary fibroblasts derived from a skin biopsy of a compound-heterozygous patient carrying two POLE1 variants. Western blot analysis confirmed detectable Pol ε protein levels, indicating preserved protein expression despite the underlying variants. Results: Nevertheless, functional alterations were observed across multiple independent assays. Compared with healthy control fibroblasts, this patient-derived Pol ε fibroblast line exhibited reduced clonogenic survival following ionizing radiation. Surviving fractions were consistently lower across radiation doses from 2 to 4 Gy, with an approximately twofold reduction at 2 Gy and progressively greater differences at higher doses. The isoeffect dose corresponding to 10% survival was reduced relative to pooled control fibroblasts. In addition, chromosomal breakage was increased, supporting altered processing of radiation-induced DNA damage in this cellular model. Live-cell imaging and senescence assays revealed delayed proliferation and an increased proportion of senescent or senescence-like cells under baseline and genotoxic stress conditions, including enhanced senescence-associated β-galactosidase activity. Flow-cytometric analysis demonstrated S phase accumulation and G2/M arrest, consistent with replication stress and cell-cycle perturbation. Immunofluorescence staining revealed increased γH2AX foci, consistent with persistent DNA double strand breaks. RAD51 foci formation was not reduced; instead, increased RAD51 recruitment was observed under combined cisplatin and irradiation treatment, arguing against a primary defect in RAD51-mediated homologous recombination. POLE1-variant fibroblasts also showed impaired proliferative recovery, reduced wound closure, increased γH2AX accumulation following cisplatin exposure, suggesting heightened susceptibility to DNA crosslinking stress. Conclusions: Collectively, these findings provide the first functional characterization of a patient-derived POLE1-variant fibroblast cell line and indicate that altered Pol ε function may influence cellular responses to genotoxic stress. While based on primary fibroblasts from a single compound-heterozygous patient, validation in additional patient-derived or isogenic models will be required to determine the broader relevance of these findings. Full article

Atrial fibrillation (AF) is the most common sustained heart rhythm disorder. It is estimated that AF affects over 52 million people worldwide, with its prevalence expected to double in the next four decades. AF significantly increases the risk of stroke and heart failure, contributing to 340,000 excess deaths annually. Beyond these life-threatening complications, AF results in limitations in physical, emotional, and social well-being causing significant reductions in quality of life and resulting in 8.4 million disability-adjusted life-years per year, highlighting the wide-ranging impact of AF on public health. Moreover, AF is increasingly recognized for its association with cognitive decline and dementia. AF is a chronic and progressive disease characterized by rapid and erratic electrical activity in the atria, often in association with structural changes in the heart tissue. AF is often initiated by triggered activity, often from ectopic foci in the pulmonary veins. These triggered impulses may initiate AF via: (1) sustained rapid firing with secondary disorganization into fibrillatory waves, or (2) by triggering micro re-entrant circuits around the pulmonary venous-LA junction and within the atrial body. In each instance, AF perpetuation necessitates the presence of a vulnerable atrial substrate, which perpetuates and stabilizes re-entrant circuits through a combination of slowed and heterogeneous conduction, as well as functional conduction abnormalities (e.g., fibrosis disrupting tissue integrity, and abnormalities in the intercalated disks disrupting effective cell-to-cell coupling). The re-entry wavelength, determined by conduction velocity and refractory period, is shortened by slowed conduction, favoring AF maintenance. One major factor contributing to these changes is the disruption of the extracellular matrix (ECM), which is induced by atrial fibrosis. Fibrosis-driven disruption of the ECM, especially in the heart and blood vessels, is commonly caused by conditions such as aging, hypertension, diabetes, smoking, and chronic inflammatory or autoimmune diseases. These factors lead to excessive collagen and protein deposition by activated fibroblasts (i.e., myofibroblasts), resulting in increased tissue stiffness, maladaptive remodeling, and impaired organ function. Fibrosis typically occurs when cardiac fibroblasts are activated to myofibroblasts, resulting in the deposition of excessive collagen and other proteins. This change in ECM interferes with the normal electrical function of the heart by creating irregular, fibrotic regions. AF and atrial fibrosis have a reciprocal relationship: AF promotes fibrosis through fibroblast activation and extracellular matrix buildup, while atrial fibrosis can sustain and perpetuate AF, contributing to higher rates of AF recurrence after treatments such as catheter ablation or cardioversion. Full article

Breast cancer is the most common cancer in women, depending on the sub-type of breast cancer treatment options are different. After completing adjuvant therapy, there are patients who may relapse even many years later. This review examines minimal residual disease, defined as small, microscopic foci of cancer cells that have survived curative treatment, have disseminated to distant tissues, and implanted there. However, the cancer cells do not exist alone but are a small part of the tumour microenvironment, described as an ecosystem. This includes stromal cells, immunosuppressive regulatory T-cells, myeloid derived suppression cells, cancer associated fibroblasts, tumour associated macrophages. The balance of the immunosuppressive tumour microenvironment and the anti-tumour immune response will determine if there is a future relapse. The interactions between the cancer cells and the tumour microenvironment are dynamic and change with time. Most therapeutic options involve therapies directed against tumour cells, only in the last few years has there been attention on the dynamic effects of the tumour microenvironment and the cancer cells on disease progression and the possibility of decreasing the risk of metastatic disease. This article reviews the latest development in preventing metastatic disease by influencing the tumour microenvironment; at best eliminating cancer cells or at least prolonging the latent period of cancer cell dormancy. Full article

Cellular senescence is a heterogeneous and dynamic state characterised by stable proliferation arrest, macromolecular damage and metabolic remodelling. Although markers such as SA-β-galactosidase staining, yH2AX foci and p53 activation are widely used as de facto standards, they are imperfect and differ in terms of sensitivity, specificity and dependence on context. We present a multifactorial imaging platform integrating scanning electron, flow cytometry and high-resolution confocal microscopy. This allows us to identify senescence phenotypes in three in vitro models: replicative ageing via serial passaging; dose-graded genotoxic stress under serum deprivation; and primary fibroblasts from young and elderly donors. We present a multimodal imaging framework to characterise senescence-associated phenotypes by integrating LysoTracker and MitoTracker microscopy and SA-β-gal/FACS, p16INK4a immunostaining provides independent confirmation of proliferative arrest. Combined nutrient deprivation and genotoxic challenge elicited the most pronounced and concordant organelle alterations relative to single stressors, aligning with age-donor differences. Our approach integrates structural and functional readouts across modalities, reducing the impact of phenotypic heterogeneity and providing reproducible multiparametric endpoints. Although the framework focuses on a robustly validated panel of phenotypes, it is extensible by nature and sensitive to distributional shifts. This allows both drug-specific redistribution of established markers and the emergence of atypical or transient phenotypes to be detected. This flexibility renders the platform suitable for comparative studies and the screening of senolytics and geroprotectors, as well as for refining the evolving landscape of senescence-associated states. Full article

Background and Objectives: Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease with few effective treatments. In its pathogenesis, damage-associated molecular patterns are released and recognized by Toll-like receptors (TLRs); all TLRs except TLR3 transduce signals through MyD88. Research has shown that autophagy participates in the progression of pulmonary fibrosis, and MyD88 is closely associated with autophagy. However, whether targeting MyD88 can affect fibrosis progression by regulating autophagy during lung fibrosis remains unclear. Materials and Methods: TJ-M2010-5 (TJ-5) is a small molecular derivative of aminothiazole that inhibits MyD88 homodimerization. A bleomycin-induced pulmonary fibrosis model in mice was established, and a human lung fibroblast cell line MRC-5 was cultured, and the mechanism of fibrosis induced by TGF-β1 was studied. TJ-5 and the autophagy inhibitor 3-MA were used to intervene. Results: Our study indicated that TJ-5 suppressed fibrosis foci formation and collagen deposition in fibrotic lungs, effectively increased the survival rate of bleomycin-stimulated mice from 40.0% to 80.0%, and repressed lung fibroblast activation in vitro. Subsequently, TJ-5 could trigger autophagy, as indicated by increased autophagosomes, LC3B-II and Beclin-1 promotion, and p62 degradation. Moreover, inhibition of TJ-5-induced autophagy by 3-MA reversed the anti-fibrosis effect of TJ-5. Furthermore, the autophagy-related pathways PI3K/AKT/mTOR and MAPK/mTOR were inhibited under TJ-5 intervention. Conclusions: Our findings demonstrated that the mechanism of TJ-5 in alleviating lung fibrosis was through triggering MyD88-related autophagy, and TJ-5 may be therapeutically useful for the clinical treatment of IPF. Full article

Background/Objectives: Pompia is an ancient, endemic citrus ecotype native to Sardinia (Italy), characterized by distinctive morphology and high content of bioactive compounds. Despite increasing interest, several aspects of this fruit, including its histological characteristics, remain poorly understood. This study aims to address this gap by investigating the anatomical features and spatial distribution of secretory cavities involved in essential oil (EO) production and accumulation, while also evaluating the EO’s chemical profile and associated biological activity. Methods: Pompia peel (flavedo and albedo) was subjected to histological analysis through fixation, dehydration, resin inclusion and sectioning. Sections were stained with 0.05% toluidine blue and observed under a light microscope to measure different parameters of secretory cavities. Essential oil (EO) was obtained from Pompia peel by hydrodistillation and characterized by gas chromatography–mass spectrometry (GC–MS) analysis. The biological activity of Pompia EO was assessed in vitro using NIH/3T3 fibroblasts, where wound-healing was evaluated by scratch assay and anti-senescence effects by β-galactosidase and γH2AX activity. Results: Microscopic analysis of the peel revealed pronounced variability in depth and size of the secretory cavities, along with the presence of lenticel-like structures in the epidermis. GC–MS analysis showed that Pompia EO is dominated by limonene (89%), with minor compounds including myrcene, geranial and neral. In vitro biological assays demonstrated that the EO promotes cell migration in a wound-healing model at concentrations ≥ 12.5 µg/mL and reduces markers of cellular senescence, including β-galactosidase activity and γH2AX foci, in etoposide-induced senescent fibroblasts. Conclusions: Overall, this study provides the first histological characterization of Pompia peel and confirms the bioactive potential of its EO. These findings support future applications in skin regeneration and anti-aging strategies and contribute to the valorization of this underexplored Citrus ecotype. Full article

High-grade serous ovarian cancer (HGSOC) is an aggressive gynecological malignancy characterized by intraperitoneal spread and chemotherapy resistance. Chemotherapies have demonstrated limited effectiveness in HGSOC, underscoring the urgent need to evaluate how the tumor microenvironment (TME) was reshaped by chemotherapy in different sites of tumor foci. In this study, we performed single-cell transcriptomic analysis to explore the TME in samples obtained from various sites of tumor foci, with or without the history of Neoadjuvant chemotherapy (NACT). We discovered that chemotherapy reshaped the tumor immune microenvironment, evident through the reduction in human leukocyte antigen (HLA) diversity and the increase in PDCD1/CD274 in CD8_ANXA1, LAMP3+ dendritic cell (DC_LAMP3), and EREG+ monocytes (mono_EREG). Moreover, cancer.cell.2, cancer-associated C3+ fibroblasts (CAF_C3), and Fibrocyte_CD34, which are prone to accumulate in the metastatic site and post-NACT group, harbored poor clinical outcome, reflected in the immune exclusion and tumor progression signaling. Cell–cell communication identified a stronger interaction between cancer.cell.2 and CAF_C3, as well as Fibrocyte_CD34, in post-NACT samples, indicating that chemotherapy reshapes pre-existing cell clusters in a site-dependent manner. Our findings suggest that chemotherapy and sites of foci were critical for the transcriptional reprogramming of pre-existed cell clusters. Our study offers a single-cell phenotype data substrate from which to develop a personalized combination of chemotherapy and immunotherapy. Full article

In a susceptible individual, persistent, low-level injury to the airway epithelium initiates an exaggerated wound repair response, ultimately leading to idiopathic pulmonary fibrosis (IPF). The mechanisms driving this fibroproliferative response are not fully understood. Here, we review recent spatially resolved transcriptomics and proteomics studies that provide insight into two distinct matricellular microenvironments important in this pathological fibroproliferation. First, in response to alveolar epithelial injury, alveolar differentiation intermediate (ADI) basal cells arising from Secretoglobin (Scgb1a1) progenitors re-populate the injured alveolus remodeling the extracellular matrix (ECM). ADI cells exhibit an interconnected cellular stress response involving the unfolded protein response (UPR), epithelial–mesenchymal transition (EMT) and senescence pathways. These pathways reprogram cellular metabolism to support fibrillogenic ECM remodeling. In turn, the remodeled ECM tonically stimulates EMT in the ADI population, perpetuating the transitional cell state. Second, fibroblastic foci (FF) are a distinct microenvironment composed of activated aberrant “basaloid” cells supporting transition of adjacent mesenchyme into hyaluronan synthase (HAS^hi)-expressing fibroblasts and myofibroblasts. Once formed, FF are the major matrix-producing factories that invade and disrupt the alveolar airspace, forming a mature scar. In both microenvironments, the composition and characteristics of the ECM drive persistence of atypical epithelium sustaining matrix production. New approaches to monitor cellular trans-differentiation and matrix characteristics using positron emission tomography (PET)–magnetic resonance imaging (MRI) and optical imaging are described, which hold the potential to monitor the effects of therapeutic interventions to modify the ECM. Greater understanding of the bidirectional interrelationships between matrix and cellular phenotypes will identify new therapeutics and diagnostics to affect the outcomes of this lethal disease. Full article

Background/Objectives: MBNL1 is an RNA-binding protein involved in RNA metabolism, including splicing. It colocalizes with RNA foci, a pathological hallmark of myotonic dystrophy, and plays a central role in its disease mechanism. Moreover, MBNL1 has been implicated in other neuromuscular disorders and cancers. In these pathological and biochemical studies, the detection of MBNL1 using antibodies is essential. Given that MBNL1 has multiple splicing-derived isoforms, different antibodies may recognize distinct isoforms. This study aims to compare six commercially available antibodies regarding their specificity in Western blotting, colocalization with RNA foci, and suitability for immunoprecipitation. Methods: Western blot analysis was performed using MBNL1 isoforms and deletion mutants expressed in HEK293 cells, as well as endogenous MBNL1 from various cell lines. RNA fluorescence in situ hybridization (FISH) and immunofluorescence (IF) were conducted in DM1 model cells and patient-derived fibroblasts to assess MBNL1 colocalization with RNA foci. Immunoprecipitation experiments were performed in HEK293 cells to evaluate antibody suitability for protein isolation. Results: Western blot analysis revealed that different antibodies target distinct regions of MBNL1, with three recognizing exon 3 and the remaining antibodies recognizing exon 4, exon 5, and exon 6, respectively. In the FISH-IF experiments, the clarity of RNA foci colocalization varied depending on the antibody used, with some antibodies failing to detect colocalization. The immunoprecipitation analysis showed that four antibodies were able to isolate endogenous MBNL1. Conclusions: This study clarifies the recognition properties and application suitability of MBNL1 antibodies, providing a valuable resource for research on MBNL1-related diseases and RNA metabolism. Full article

Acute myocardial infarction, a leading cause of death globally, is often associated with cardiometabolic disorders such as atherosclerosis and metabolic syndrome. Metabolic treatment of these disorders can improve cardiac outcomes, as exemplified by the GLP-1 agonist semaglutide. Fibroblast growth factor 21 (FGF21), a novel metabolic regulator, plays pivotal roles in lipid mobilization and energy conversion, reducing lipotoxicity, inflammation, mitochondrial health, and subsequent tissue damage in organs such as the liver, pancreas, and heart. Here, we test the therapeutic efficacy of FGF21 in mice with ischemia–reperfusion (I/R) injury, a model of acute myocardial infarction. We employed the strategic method of coating the FGF21-encapsulating liposomal nanoparticles with a neutrophil membrane designed to camouflage FGF21 from macrophage-mediated efferocytotic clearance and promote its targeted accumulation at I/R foci due to the inherent neutrophilic attraction to the inflammatory site. Our findings revealed that the coated FGF21 nanoparticles markedly accumulated within the lesions with a prolonged half-life, in additional to the liver, leading to substantial improvements in cardiac performance by enhancing mitochondrial energetic function and reducing oxidative stress, inflammation, and cell death. Therefore, our research highlights a viable strategy for the enhanced delivery of therapeutical FGF21 analogs to lesions beyond the liver following myocardial infarction. Full article

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease characterized by repetitive alveolar injuries with excessive deposition of extracellular matrix (ECM) proteins. A crucial need in understanding IPF pathogenesis is identifying cell types associated with histopathological regions, particularly local fibrosis centers known as fibroblast foci. To address this, we integrated published spatial transcriptomics and single-cell RNA sequencing (scRNA-seq) transcriptomics and adopted the Query method and the Overlap method to determine cell type enrichments in histopathological regions. Distinct fibroblast cell types are highly associated with fibroblast foci, and transitional alveolar type 2 and aberrant KRT5-/KRT17+ (KRT: keratin) epithelial cells are associated with morphologically normal alveoli in human IPF lungs. Furthermore, we employed laser capture microdissection-directed mass spectrometry to profile proteins. By comparing with another published similar dataset, common differentially expressed proteins and enriched pathways related to ECM structure organization and collagen processing were identified in fibroblast foci. Importantly, cell type enrichment results from innovative spatial proteomics and scRNA-seq data integration accord with those from spatial transcriptomics and scRNA-seq data integration, supporting the capability and versatility of the entire approach. In summary, we integrated spatial multi-omics with scRNA-seq data to identify disease-associated cell types and potential targets for novel therapies in IPF intervention. The approach can be further applied to other disease areas characterized by spatial heterogeneity. Full article

Fibrotic focus is a pivotal morphofunctional unit in developing fibrosis in various tissues. For most fibrotic diseases, including progressive forms, the foci are considered unable to remodel and contribute to the worsening of prognosis. Unfortunately, the dynamics of the fibrotic focus formation and resolution remains understudied. A number of data suggest that the key cell type for focus formation are activated stromal cells marked by fibroblast activated protein alpha (FAPα) due to their high capacity for extracellular matrix (ECM) remodeling. We evaluated the dynamics of fibrotic focus formation and the contribution of the main cell types, including FAPα+ cells, in this process using a murine model of bleomycin-induced lung fibrosis. We revealed the very early appearance of FAPα+ cells in lungs after injury and assumed their important involvement to the myofibroblast pool formation. During the first month after bleomycin administration, FAPα+ cells colocalize with CD206+ M2 macrophages. Interestingly, during the reversion stage, we unexpectedly observed the specific structured foci formed by CD90+FAPα+ cells, which we suggested calling “remodeling foci”. Our findings highlight the crucial role of activated stromal cells in fibrosis initiation, progression, and reversion and provide emerging issues regarding the novel targets for antifibrotic therapy. Full article

Lung cancer continues to have one of the highest morbidity and mortality rates of any cancer. Although radiochemotherapy, in combination with immunotherapy, has significantly improved overall survival, new treatment options are urgently needed. However, preclinical radiotherapy testing is often performed in animal models, which has several drawbacks, including species-specific differences and ethical concerns. To replace animal models, this study used a micro-extrusion bioprinting approach to generate a three-dimensional (3D) human lung cancer model consisting of lung tumor cells embedded in human primary lung fibroblasts for radiotherapy research. The models were placed in a mouse phantom, i.e., a 3D-printed mouse model made of materials that mimic the X-ray radiation attenuation rates found in mice. In radiotherapy experiments, the model demonstrated a selective cytotoxic effect of X-rays on tumor cells, consistent with findings in 2D cells. Furthermore, the analysis of metabolic activity, cell death, apoptosis, and DNA damage-induced γH2AX foci formation revealed different results in the 3D model inside the phantom compared to those observed in irradiated models without phantom and 2D cells. The proposed setup of the bioprinted 3D lung model inside the mouse phantom provides a physiologically relevant model system to study radiation effects. Full article

Children with cancer previously treated with radiotherapy face the likelihood of side effects that can be debilitating or fatal. This study aimed to assess the long-term effect of medulloblastoma radiotherapy on the DNA double-strand break (DSB) repair capability of primary fibroblasts derived from lung biopsies of previously irradiated young sheep. This study included biopsies from three control and five irradiated sheep. The treated sheep had previously received spinal radiotherapy at a total dose of 28 Gy, which is equivalent to pediatric medulloblastoma treatment. Lung biopsies were taken 4 years post-irradiation from high-dose (HD, >18 Gy) and low-dose (LD, <2 Gy) regions. Fifteen cell lines were extracted (six control, four LD and five HD). The cells were irradiated, and DNA DSB repair was analyzed by immunofluorescence. Clonogenic, trypan blue and micronuclei assays were performed. Both the HD and LD cell lines had a significantly higher number of residual γH2AX foci 24 h and a significant decrease in pATM activity post-irradiation compared to the control. There was no statistically significant difference in the clonogenic assay, trypan blue and micronuclei results. Our study showed that a previous irradiation can impair the DNA DSB repair mechanism of ovine lung fibroblasts. Full article