Search Results (456)

The laminin-derived nonapeptide CDPGYIGSR contains the bioactive YIGSR motif, historically associated with inhibition of tumor cell adhesion, invasion, angiogenesis, and laminin-receptor-mediated cell responses. Although these activities have often been attributed to the 37/67 kDa laminin receptor/RPSA axis, the molecular identity and organization of the laminin-binding receptor system remain debated. This uncertainty makes it essential to define the intrinsic conformational preferences of CDPGYIGSR in solution before assigning a unique receptor-bound structure. In this study, temperature replica-exchange molecular dynamics (T-REMD) simulations in explicit solvent are employed to characterize the solution conformational ensemble of CDPGYIGSR. Free energy landscape analysis, clustering, and structural descriptors reveal a predominant compact bend-like backbone arrangement, together with alternative low-lying conformational states within a heterogeneous ensemble. Rather than assuming a single bioactive conformation, the conformational ensemble is analyzed in terms of structural features that are consistent with available NMR observations and reported structure–activity relationships. Importantly, the most populated conformations in solution do not necessarily correspond to the bioactive state upon receptor binding. Instead, a subset of conformations sharing common structural motifs, including a central backbone bend and specific residue exposure patterns, may represent states compatible with receptor recognition. These results provide an ensemble-based structural framework that connects simulation-derived conformational motifs with available NMR observations and structure–activity data, supporting a recognition-compatible ensemble model in which compact preorganized states may contribute to receptor binding. Full article

Epidermolysis bullosa (EB) is a group of genetic diseases characterized by skin fragility. Although therapeutic options aim to accelerate wound-healing, improvement is needed; therefore, birch bark and propolis were investigated due to their beneficial biological properties. A representative ethanolic extract was analyzed by reversed-phase high-performance liquid chromatography with diode array detection (RP-HPLC-DAD) for chemical profiling of the raw materials. A hydrophobic natural deep eutectic solvent (HNaDES) for birch bark extraction, as well as a hydrogel and a bigel enriched with propolis and birch bark extract, were prepared and characterized by Fourier transform infrared (FT-IR) spectroscopy. Cytotoxicity and wound-healing potential were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and scratch assays in six human keratinocyte cell lines: two from healthy individuals, two from recessive dystrophic ΕΒ patients (RDEB), and two from laminin-332-deficient junctional EB patients (JEB). RP-HPLC-DAD revealed the presence of phenolic compounds (e.g., chrysin, pinocembrin, pinobanksin) and pentacyclic triterpenes (e.g., betulin and betulinic acid), characteristic of propolis and birch bark, respectively. FT-IR confirmed HNaDES formation and indicated physical interactions within the gels. All systems exhibited no cytotoxicity at 1 μg/mL and increased cell vitality. Moreover, in keratinocytes derived from JEB patients, hydrogel improved wound- healing significantly at 24 h, whereas bigel showed significant improvement at 8 h. The developed systems could be promising topical treatments. Full article

Intercellular communication is crucial for the coordination of skeletal muscle development. However, the intricate signaling networks that regulate chicken myogenesis are not yet fully elucidated. In this study, we utilized CellChat analysis on single-cell and single-nucleus RNA sequencing data to systematically delineate cell–cell communication patterns across five critical developmental stages of chicken skeletal muscle: embryonic day 4 (E4), day 6 (E6), day 12 (E12), day 18 (E18), and post-hatch day 30 (P30). Our findings indicate that communication architectures are highly stage-specific, with mesenchymal cells acting as the predominant signaling hub during the early embryonic stages (E4–E6), whereas fibro-adipogenic progenitors become the principal communicators during mid-to-late embryogenesis (E12–E18). At E4, the communication network was relatively simple, comprising 51 ligand–receptor pairs primarily involving the neural cell adhesion molecule, slit guidance ligand, and midkine (MK) signaling pathways between myogenic progenitors and mesenchymal cells. By E6, the network had expanded significantly, encompassing 6237 ligand–receptor pairs across 51 signaling pathways, which coincided with the emergence of multiple myogenic lineages. Peak communication complexity was observed at E12, characterized by 11,675 ligand–receptor pairs and 61 signaling pathways, reflecting the secondary wave of myogenesis. Comparative analysis across developmental stages revealed key signaling transitions: the pleiotrophin and MK pathways were predominantly active during the early phase of myogenic commitment (E4–E6), whereas the collagen, laminin, and adhesion G protein-coupled receptor L pathways were more prominent during the secondary myogenesis phase (E6–E12). Notably, a significant shift in communication patterns was observed from E12 to E18, marked by a reduction in developmental pathway signaling and an increase in immune-related communications. By P30, the communication network had stabilized into a homeostatic state, centered on interactions among myofibers, stromal cells, and the vascular system. This comprehensive atlas of intercellular communication offers novel insights into the signaling dynamics underpinning chicken skeletal muscle development. Full article

The extracellular matrix (ECM) regulates skeletal muscle development through biochemical signaling and mechanical interactions. While Matrigel supplementation is commonly used to enhance engineered muscle formation, the contribution of specific ECM proteins remain incompletely defined in 3D systems. Here, we evaluated the effects of laminin and fibronectin supplementation on myogenic differentiation in collagen type I hydrogels and assessed their influence on passive tissue compaction and alignment in 3D constructs. Two-dimensional collagen hydrogels supplemented with increasing concentrations (0–100 µg/mL) of laminin or fibronectin were screened to maximize the myoblast fusion index. These concentrations were incorporated into 3D myocyte-seeded hydrogels cultured between flexible posts to quantify passive compaction forces via cantilever mechanics. Fibronectin supplementation (10 µg/mL) resulted in significantly greater early post displacement and sustained passive compaction compared to laminin-supplemented and unsupplemented controls. Constructs cultured under tension between posts exhibited enhanced alignment, with fibronectin further increasing the proportion of fibers oriented within 0–20° of the tension axis. Together, these findings demonstrate that fibronectin enhances early passive compaction dynamics and tension-mediated alignment in collagen-based skeletal muscle constructs. These results provide insight into how specific ECM components influence 3D tissue organization and may inform the design of engineered muscle models for regenerative applications. Full article

Asthma is characterized by persistent airway epithelial dysfunction and remodelling of the reticular basement membrane (RBM). In healthy airways, the RBM is primarily composed of the extracellular matrix (ECM) proteins laminin and collagen-IV, but in remodelled asthmatic airways, the RBM has increased deposition of collagen-I, -III and fibronectin. Here, we systematically compared the effects of collagen-I, -III, -IV, fibronectin, laminin, and bovine serum albumin (BSA) control on bronchial epithelial cells (BECs) from six healthy controls and seven individuals with asthma. Epithelial attachment, spreading and barrier function were assessed in real time over 72 h using electrical cell–substrate impedance sensing. Cell culture supernatants were analyzed for release of epithelial cytokines, thymic stromal lymphopoietin (TSLP), interleukin (IL)-6, IL-8, and IL-11 using ELISA. BECs from both control and asthma donors had faster cell attachment, spreading, and barrier formation on collagen-I, -III, -IV, and fibronectin compared to laminin and BSA. BECs from both control and asthma donors cultured on collagen -I and -III produced more TSLP, but had no effect on IL-6, IL-8, and IL-11 expression. In summary, remodelling of the RBM in asthma may promote epithelial barrier formation whilst simultaneously enhancing epithelial-derived Th2 inflammation through increased TSLP release. Full article

Dietary polyphenols such as quercetin, resveratrol, and (−)-epigallocatechin-3-gallate (EGCG) have shown neuroprotective effects in epidemiologic and experimental studies of Alzheimer’s disease (AD), although clinical evidence remains limited. This review highlights the importance of investigating glucuronide and sulfate conjugates of these polyphenols, as well as their intestinal microbial metabolites, at bioavailable low nanomolar concentrations, particularly those capable of reaching the brain. Although many in vitro studies use micromolar concentrations of aglycones, the relevance of such concentrations to neuroprotection remains uncertain. While polyphenols are redox-sensitive, their direct antioxidant or prooxidant effects may be limited at nanomolar concentrations. Instead, their neuroprotective actions appear to be mediated through high-affinity interactions with molecular targets such as the 67-kDa laminin receptor (67LR). This receptor binds both aglycones and conjugates at low nanomolar concentrations through a peptide G region containing glycosaminoglycan- and palindromic sequence-related motifs. The same region also binds the prion–amyloid-β complex, suggesting that polyphenols may antagonize amyloid-β binding and thereby prevent its neurotoxicity. The peptide G region may also function as a redox sensor. Binding of polyphenols to 67LR activates cAMP signaling and downstream neuroprotective pathways involving CREB, SIRT1, and protein phosphatase 2A. In addition, nanomolar concentrations of resveratrol and quercetin inhibit quinone reductase 2, an enzyme associated with cognitive decline and reported to be elevated in AD. Given their low bioavailability in the brain and their distinct molecular targets, combining multiple polyphenols at low doses may produce additive or synergistic effects, enhance efficacy, and minimize potential toxicity in the prevention of AD. Full article

Preeclampsia (PE) is a severe pregnancy-specific hypertensive disorder characterized by immune microenvironment dysregulation at the maternal–fetal interface, with decidual macrophage phenotypic imbalance being a key pathological feature. The Ghrelin/growth hormone secretagogue receptor-1a (GHSR-1a) axis exerts immunomodulatory and anti-inflammatory effects, but its role in regulating decidual macrophage infiltration and phenotypic marker expression in PE remains unclear. In this study, we first detected the expression of the Ghrelin/GHSR-1a axis in decidual tissues from 10 healthy pregnant women and 12 PE patients via immunohistochemistry (IHC). We then established a lipopolysaccharide (LPS)-induced PE-like rat model to investigate the axis’s functional role and underlying mechanisms. Intriguingly, clinical analysis revealed a severity-dependent compensatory escalation of the Ghrelin/GHSR-1a axis in PE decidual tissues, potentially representing an endogenous antagonistic response to pregnancy-associated pathological stress. In the animal model, exogenous Ghrelin supplementation reversed LPS-induced PE-like phenotypes, including hypertension, proteinuria, fetal growth restriction (FGR), and placental dysfunction, and alleviated pathological damage to the maternal liver, kidney, and placenta. Mechanistically, Ghrelin modulated decidual macrophage phenotypic marker expression by downregulating the M1 marker CD86 and upregulating the M2 marker CD163 and promoted trophoblast invasion and spiral artery remodeling by restoring laminin, α-cytokeratin 7 (α-CK7), and α-smooth muscle actin (α-SMA) expression in placental tissue. All protective effects of Ghrelin were abrogated by co-administration of D-lys-3-GHRP-6, a specific GHSR-1a antagonist, confirming the dependence on the Ghrelin/GHSR-1a axis. Collectively, our findings suggest that the Ghrelin/GHSR-1a axis is compensatorily upregulated in PE and may exert a protective role by regulating decidual macrophage phenotypic marker expression and improving placental function, providing preliminary evidence that this axis merits further investigation as a potential research target for PE. Full article

Background: Vasculogenic mimicry (VM) is a tumor-driven vascularization strategy in which aggressive cancer cells form perfusable, endothelium-independent channels that support tumor growth, metastasis, and therapy resistance. VM is prevalent in triple-negative breast cancer (TNBC), but within this group of tumors, VM heterogeneity is underexplored. Likewise, VM competence and its relationship to classical endothelial angiogenesis (EA) remain incompletely understood. Methods: Here, as a proof of concept, we combine functional analysis of three molecularly distinct TNBC cell lines with a panel-wide DepMap transcriptomic survey to characterize VM heterogeneity. Results: Using an in vitro tube formation assay, we show that the VM-competent TNBC cell lines MDA-MB-231 and MDA-MB-231-4175 form robust 3D vessel-like networks in a matrigel matrix, whereas the VM-incompetent line MDA-MB-468 does not. As a control, we use an immortalized endothelial cell line, 3B-11, that forms classical EA vessel-like networks. Moreover, we visualize VM (Laminin-5⁺) and EA (CD31⁺) markers in vessel-like networks of VM-competent TNBC xenografts using immunohistochemical staining and show that while they are distinctly labeled, they can also coexist to form mosaic-like vessels. Then, we use DepMap-based transcription profiles and reveal that VM competence is associated with a distinct signature. Interestingly, VM and EA transcription profiles partially overlap, yet they also remain transcriptionally distinct, with inferred mechanistic divergence, with VM being more associated with cancer cell stemness (CSC), epithelial-to-mesenchymal transition (EMT), and extracellular matrix (ECM) remodeling programs and EA being more associated with vessel strength. In addition, VM-competent TNBC cells display migration patterns and transcriptomic features consistent with endothelial-like mechanosensitivity. Conclusions: Together, these findings indicate that VM is a distinct, heterogeneous, and therapy-relevant state in TNBC that complements classical angiogenesis. Finally, the mechanistic distinction between VM and EA programs made here will motivate future studies on dual-targeting strategies that inhibit both vascularization processes while also motivating future studies on VM for precision treatment in TNBC. Full article

Skeletal muscle satellite cells (SMSCs) are essential for embryonic myogenesis and postnatal muscle regeneration; however, their cellular heterogeneity and transcriptional dynamics during avian development remain largely unexplored. Here, we performed single-cell RNA sequencing (scRNA-seq) on 42,886 cells isolated from goose leg muscles across four embryonic stages (E13, E15, E18, and E23), with each stage comprising pooled tissues from four female embryos. Unbiased clustering resolved 22 transcriptionally distinct clusters representing six major cell types—satellite cells, myocytes, fibro-adipogenic progenitors, endothelial cells, immune cells, and Schwann cells—with satellite cells being the most abundant. Satellite cells were further subdivided into three functional states (quiescent, activated, and proliferative/differentiating), which followed a continuous, linear pseudotime trajectory from early to late embryonic stages. This trajectory was marked by a progressive downregulation of stemness-associated regulators (e.g., PAX7) and upregulation of myogenic commitment and differentiation factors (e.g., MYF5, MYOD1, and MYOG), faithfully mirroring chronological development. Cell–cell communication analysis revealed that quiescent satellite cells exhibited the most extensive intercellular signaling networks (e.g., FGFR, Ephrin, collagen, CADM), whereas activated and proliferative/differentiating cells showed progressively diminished communication capacity. Across developmental stages, the contribution intensities of key signaling pathways—including SEMA6, CDH, FGF, LAMININ, MK, MPZ, CADM, FN1, and COLLAGEN—varied significantly among satellite cell states, indicating state-specific responsiveness to microenvironmental cues. Collectively, these findings demonstrate that satellite cells dynamically coordinate extrinsic signal integration with intrinsic differentiation programs to achieve orderly myogenic progression. This study provides a high-resolution single-cell atlas of goose SMSC development, uncovering subpopulation heterogeneity, state-specific molecular signatures, and key signaling pathways, with important implications for avian muscle biology and genetic improvement of poultry. Full article

Introduction: Glioblastoma (GBM) is the most aggressive primary tumor of the central nervous system and is highly resistant to temozolomide (TMZ). Rutin is a potent antioxidant with immunomodulatory and anti-glioma effects in vitro, although its mechanisms of action remain incompletely understood. This study investigated the effects of rutin on morphology, viability, redox balance, and pro-tumoral signaling in GBM 2D cultures and 3D spheroids, as well as its association with TMZ sensitivity. Methods: GL15 and U343 human GBM cell lines and primary astrocytes were treated with rutin (5–30 μM) and/or TMZ (125–4000 μM). Cell metabolic activity and viability were assessed by MTT, PI/DiOC18(3) or PI/Hoechst. Cell migration was assessed from spheroid-derived cells, and extracellular matrix (ECM) components (fibronectin and laminin) were evaluated by immunofluorescence. Intracellular reactive oxygen species (ROS) were measured by DCFH-DA fluorescence. IL-6, STAT3, NOS2, and IDO1 gene expression were determined by RT-qPCR, and protein expression of MMP2, fibronectin, STAT3, PI3K, and AKT by Western blotting. Nitric oxide (NO) and L-kynurenine levels were quantified in the supernatant by colorimetric assays. Results: Rutin reduced cell viability and enhanced TMZ cytotoxicity in both 2D and 3D cultures, while exerting selective effects by increasing metabolic activity and attenuating TMZ-induced effects in non-tumoral primary astrocytes. In 3D spheroids, rutin affected structural organization and reduced spheroid-derived cell migration, accompanied by changes in ECM components, including MMP2, fibronectin, and laminin. Rutin decreased intracellular ROS levels and suppressed the TMZ-induced increase in ROS and NOS signaling. These effects were accompanied by modulation of IL-6/STAT3 signaling, along with reduced STAT3, PI3K, and AKT protein levels. Rutin also modulated immunometabolic parameters, including extracellular L-kynurenine and nitric oxide levels, and enhanced TMZ responsiveness following pre-sensitization. Conclusions: Rutin enhances TMZ responsiveness by modulating interconnected pro-tumoral mechanisms, including redox balance, pro-survival signaling, ECM remodeling and migratory behavior, and immunometabolic pathways linked to chemoresistance, supporting its potential as an adjuvant therapeutic strategy. Full article

Microglia are brain immune cells that phagocytose cell debris and beta-amyloid plaques in patients with Alzheimer’s disease. They develop from round amoeboid cells into ramified microglia or large macrophages, which can be studied in three-dimensional organotypic mouse brain slices. In a recent publication, we showed for the first time that we can track GFAP+ astrocytes and laminin+ vessels in organotypic brain slices using live-cell imaging . The aim of the present study was to use microcontact printing on organotypic brain slices to label microglia with Iba1 and CD11b antibodies and visualise them through live-cell imaging. We show that microglia can be easily labelled with antibodies and tracked via live-cell fluorescence microscopy for up to 20 days. Incubation in lipopolysaccharide (LPS) or granulocyte–macrophage colony-stimulating factor (GM-CSF) stimulates the migration of round amoeboid microglia, whereas interleukin-10 induces their differentiation into ramified forms. Taken together, we show the first-time live cell imaging of microglia in organotypic mouse brain slices using microcontact printing. Full article

Background: Corneal organoids derived from pluripotent stem cells have emerged as powerful tools for studying corneal development, disease modeling, and regenerative medicine applications. While previous protocols have successfully generated corneal tissue structures, there remains a need for three-dimensional models that recapitulate the complex cellular architecture and diversity of native human cornea. Methods: We developed a modified spontaneous three-dimensional corneal organoid model using human embryonic stem cells (hESCs) through an adapted Self-formed Ectoderm Autonomous Multi-zone (SEAM) protocol. hESCs were cultured as spheroids in ultra-low-binding plates under normoxic conditions and differentiated over 7–8 weeks. Organoids were characterized using immunofluorescence staining for corneal-specific markers and single-cell RNA sequencing to assess cellular composition and gene expression patterns. Results: Approximately 20% of organoids developed transparent regions characteristic of corneal tissue by day 30 of differentiation. Immunofluorescence analysis revealed spatially organized expression of corneal markers, including ZO-1 and E-cadherin in the outermost epithelial layers, P63α-positive putative limbal stem cells at the epithelial–stromal interface, vimentin-positive stromal cells in the interior, and laminin-1 deposition that suggests Bowman’s membrane formation. The organoids expressed cornea-specific keratins (K3, K12, and K15) and the master regulator PAX6 in appropriate cellular compartments. Single-cell RNA sequencing identified 18 distinct cell clusters, including three corneal epithelium subclusters with differential expression of MUC16, KRT12, and ΔNp63α, two stromal populations with distinct inflammatory profiles, and a corneal endothelium cluster. Transcriptomic analysis confirmed expression of key corneal genes, including AQP3, CDH1, multiple keratins, mucins, and extracellular matrix components (HAS2, CD34, CD44, COL8A1, and KERA). Conclusions: This three-dimensional spheroid-based putative corneal organoid model successfully recapitulates the multilayered architecture and cellular diversity of human cornea, including stratified epithelium, putative limbal stem cells, stroma, and endothelium in spatially appropriate arrangements. The model demonstrates molecular signatures consistent with native corneal tissue and provides a valuable platform for studying corneal development, disease mechanisms, and potential therapeutic applications. Future optimization to improve organoid formation efficiency and functional maturation will enhance the utility of this system for both basic research and translational medicine. Full article

Background and Objectives: Peripheral nerve adaptation to different pathological conditions is accompanied by the remodelling of the nerve’s extracellular matrix (ECM). Ischemic conditions caused by peripheral vascular disease are known to affect the function of peripheral nerves; however, the morphological changes to their ECM remain insufficiently examined and understood. Bearing in mind that alterations in collagen I, collagen IV, and laminin content may compromise peri- and endoneurial integrity, the aim of our study was to analyse whether peripheral vascular disease (PVD) induces distinct ECM alterations in the human sural nerve compared with the adaptive remodelling observed in ageing. Materials and Methods: The study aimed to determine the amount of type I and IV collagen and laminin in the perineurium and endoneurium of human peripheral nerves from patients with PVD and to compare the results with those of the age-matched controls. Twenty human sural nerves were harvested from cadavers and amputated limbs—10 from each—and were further distributed into two age groups: below and over 75 years of age. The sural nerve tissue samples were stained immunohistochemically for collagen I, collagen IV, and laminin. We measured the percentage content of these ECM components in the perineurium and endoneurium. For morphometric analysis, we used ImageJ software v1.54d. Results: Perineurial collagen type I and laminin were decreased in the older PVD group, relative to both the younger PVD and the older age group. Within the endoneurium, the expression of collagen type IV was higher in older PVD patients, while both collagen type I and laminin were deposited in lower amounts in the same group compared with the younger PVD group. Conclusions: These findings suggest that age-related ECM remodelling in the peripheral nerve may be impaired under ischemic conditions in older adults, with implications for surgical grafting strategies or neural conduit therapies aimed at promoting functional regeneration. Full article

Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes and can lead to severe visual impairment. Based on disease severity, DR is classified into no clinically apparent diabetic retinopathy (NDR), non-proliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy (PDR). Although nearly all retinal cell types are involved in DR progression, the dominant cell populations and their pathophysiological changes at each stage remain unclear. By integrating bulk and single-cell transcriptomic data from human and mouse retinas, this study revealed the following: (1) In the NDR stage, photoreceptors exhibit significant changes in ribosomal pathways. (2) In the NPDR stage, endothelial cells and pericytes show marked transcriptional alterations, accompanied by enhanced LAMININ signaling in cell-cell communication. (3) At the PDR stage, neural and glial cells are extensively involved in disease progression, with notable changes in ANGPTL signaling. Additionally, this study observed DR-specific subtypes of endothelial cells and pericytes and potentially identifies gene signatures in macroglia cells that correlate with disease duration. The altered expression of several key genes in early diabetic retina was confirmed by qPCR. These findings may offer a comprehensive view of the cellular and molecular landscape underlying DR and may suggest potential targets. Full article

Background: An emerging tool to better simulate the complexity of tumour biology in vitro is 3D culture models. Several approaches have been introduced, yet many face challenges such as technical complexity or limited ability to reproduce critical tumour traits. Modular tissue engineering is a well-known method in tissue transplantation, where it has been used to develop various healthy tissue constructs. In this study, we set out to adapt this established approach to fabricate cancer microtissues and to assess their effectiveness as a tumour model that can capture essential features of cancer biology and drug-treatment response. Methods: Two triple-negative breast cancer (TNBC) cell lines, HCC1806 and MDA-MB-231, were cultured in microtissues and assessed for viability, cell death, generation of hypoxia and response to chemotherapy. To benchmark our model, we utilized flow cytometry to analyze the CD44⁺/CD24⁻ cancer stem cell (CSC) phenotype across microtissues, 2D monolayers, and established 3D models, including spheroids, collagen domes, and laminin-rich domes. Results: The cells showed sustained cell viability with minimal cell death, along with natural development of tumour properties, such as hypoxia. Crucially, flow cytometry revealed a cell-line-dependent regulation of the CD44⁺/CD24⁻ phenotype, underscoring the complex influence of the 3D microenvironment on stem cell regulation. Furthermore, by screening the model with standard anti-breast cancer chemotherapeutics, we observed drug resistance at concentrations comparable to those used in the clinic. Conclusions: Our model offers the unique ability to spontaneously reproduce fundamental features of tumours in vitro, capturing the cellular heterogeneity and reprogramming that drive clinical drug resistance. Full article