Search Results (613)

Hyaluronan (HA) is a ubiquitous extracellular matrix (ECM) component that is gaining significant attention for its diverse roles in cell signalling and disease. The biological functions of HA are dependent on its molecular weight (M_w): low M_w polysaccharide chains drive stimulatory processes such as inflammation and angiogenesis, whereas high M_w HA is stabilising and anti-inflammatory. Growing evidence indicates that HA is integral to brain function. The composition of HA in the brain is regulated by the balance of enzymatic synthesis and degradation, mediated by different isoforms of hyaluronan synthase (HAS) and hyaluronidase (HYAL) respectively. Fluctuating expression of the genes encoding the HAS and HYAL enzymes has been implicated in neuropathology and ageing, with some studies providing evidence towards epigenetic regulation of these genes. The regulatory environment of the brain confers a unique balance of enhanced protection alongside the requirement for maximum flexibility. This scoping review focuses on summarising current knowledge regarding epigenetic regulation of HAS and HYAL genes in neural contexts, as well as identifying gaps in knowledge against which future research can be directed. Understanding how these genes are regulated, particularly through epigenetic mechanisms, provides insight into how HA is regulated in the brain, facilitating understanding regarding its function in brain health and disease. Full article

Skin aging is driven by both intrinsic and extrinsic factors, including ultraviolet (UV) radiation and environmental stressors. Tumor necrosis factor-alpha (TNF-α) is a key pro-aging cytokine that promotes reactive oxygen species (ROS) production, leading to collagen degradation and inflammatory responses in skin cells. In this study, we investigated the protective effects of Prunus persica flower extract and its major constituents (1–4) against TNF-α–induced oxidative and inflammatory responses in human dermal fibroblasts (HDFs) and human epidermal keratinocytes (HEKs). In HDFs, the extract and isolated compounds significantly suppressed TNF-α–induced ROS generation and matrix metalloproteinase-1 (MMP-1) secretion while enhancing collagen synthesis. Notably, mandelamide (4) markedly reduced MMP-1 secretion (from 7.53 ± 0.28 to 2.97 ± 0.12, p < 0.001) and restored collagen levels (from 3.3 ± 0.03 to 19.1 ± 0.58, p < 0.001). In HEKs, mandelamide attenuated the production of inflammatory mediators under TNF-α stimulation and further suppressed MMP expression while restoring the mRNA expression of hyaluronan synthase genes under TNF-α/ interferon-γ (IFN-γ) co-stimulation. Importantly, mandelamide exhibited selective activity under inflammatory conditions without affecting basal cellular states. Collectively, these findings demonstrate that mandelamide is a key bioactive constituent of Prunus persica (P. persica) flowers and exerts protective effects against inflammation-associated skin aging through the modulation of oxidative stress and extracellular matrix homeostasis. Full article

Inflammation and oxidative stress play important roles in alcohol-induced liver injury. Hyaluronan (HA), a naturally occurring polysaccharide proven to exhibit antioxidant and anti-inflammatory functions, has garnered growing research attention in the field of food in recent years. This study demonstrates that long-term oral administration of HA exerts a protective effect against acute alcohol-induced liver injury (AALI). The findings showed that oral administration of 30, 600, and 1250 kDa HA for 2 and 4 weeks all increased serum and liver HA levels in rats and regulated the composition and abundance of gut microbiota. Meanwhile, oral HA could alleviate the symptoms of liver injury caused by alcohol, including increasing glutathione (GSH) levels, reducing malondialdehyde (MDA) and triglyceride (TG) levels, and decreasing the content of inflammatory factors interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) compared with the AALI model mice. Furthermore, HA could inhibit the increase in reactive oxygen species (ROS) levels in AML12 cells induced by alcohol and improve the survival rate of alcohol-damaged AML12 cells. In conclusion, this study found that oral administration of HA could increase serum and liver HA levels and has a protective effect on AALI, suggesting the application of HA in health foods for hangover relief and liver protection. Full article

Objective: This study aims to analyze the dynamic changes in lymphatic endothelial cell (LEC) markers during the progression of intervertebral disk degeneration (IDD) and to investigate their association with the progression of IDD. Method: In this study, intervertebral disk (IVD) specimens were first collected from patients who underwent open lumbar fusion surgery for spinal fractures (control group, n = 10) and lumbar disk herniation (IDD group, n = 10). Concurrently, a mouse IDD model was established, and IVD specimens were collected from mouse in the Sham group and the IDD group 1, 3, and 6 weeks after modeling (n = 5 per group at each time point). Pathological morphological changes in human and mouse IVD specimens were observed using Hematoxylin and Eosin (H&E) and Masson’s Trichrome staining. The degree of degeneration in the mouse IVD specimens was quantified using a histopathological scoring system. Subsequently, real-time quantitative polymerase chain reaction (RT-qPCR), immunohistochemistry (IHC), and immunofluorescence (IF) staining were employed to examine LEC markers in IVD tissue, including lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), podoplanin (PDPN), prospero homeobox protein 1 (PROX-1), and vascular endothelial growth factor receptor 3 (VEGFR-3), as well as matrix metabolism-related markers such as matrix metalloproteinase 13 (MMP-13) and collagen II (Col II). Finally, we performed Spearman’s rank correlation analysis between the histopathological scores of all mouse IVD specimens and the corresponding expression levels of LEC markers. Results: In human IVD tissue, expression levels of LYVE-1, PDPN, PROX-1, and VEGFR-3 were extremely low in the normal group. In contrast, expression of these markers was significantly upregulated in the IDD group. In the mouse IDD model, compared with the Sham group at the same time point, the IDD group exhibited higher histopathological scores in IVD tissue, accompanied by upregulation of LYVE-1, PDPN, PROX-1, and MMP-13, as well as downregulation of Col II. In-depth analysis revealed that these differences between the Sham and IDD groups were not static but exhibited a dynamic pattern of increasing magnitude over time. Concurrently, as the modeling period progressed, the histopathological scores of mouse IVD in the IDD group, as well as the expression levels of LYVE-1, PDPN, PROX-1, and MMP-13, showed a progressive upward trend, while Col II expression progressively decreased. In addition, Spearman’s rank correlation analysis revealed that the expression levels of LYVE-1, PDPN, and PROX-1 in mouse IVD tissue were all significantly positively correlated with histopathological scores. Conclusions: In the process of IDD, the dynamic upregulation of LEC markers is highly consistent with its severity in the time dimension. At the same time, there was also a significant positive correlation between the expression level of LEC markers and the severity of IDD. Taken together, these findings suggest that the dynamic upregulation of LEC markers may be potentially associated with the pathological progression of IDD. Full article

Atherosclerosis remains the leading cause of death worldwide and imposes a major healthcare burden. Physiologically, elimination of cholesterol from the arterial wall depends on reverse cholesterol transport (RCT). RCT requires access to HDL and apolipoprotein A-I (ApoA-I) to lesional macrophages/foam cells. The endothelial glycocalyx is a dynamic and injury-sensitive layer of proteoglycans and glycosaminoglycans (including hyaluronan). It contributes to vascular barrier properties, leukocyte adhesion, mechanotransduction, and macromolecular transport. In atherosclerosis, glycocalyx structure and function are altered; this may facilitate entry/retention of atherogenic lipoproteins and may also alter transport conditions relevant to cholesterol efflux pathways. This article presents a mechanistic hypothesis: short, transient, systemic hyaluronidase exposure could temporarily remodel glycocalyx/extracellular matrix components and thereby facilitate conditions permissive for regulated transport processes relevant to RCT. However, the proposed link between glycocalyx remodeling and improved lesional cholesterol efflux remains theoretical. Direct in vivo evidence that the endothelial glycocalyx is a dominant barrier limiting HDL- or ApoA-I-mediated cholesterol efflux from plaque macrophages is currently limited. Moreover, glycocalyx degradation is widely associated with endothelial dysfunction, increased permeability, inflammation, and thrombosis, all of which could aggravate rather than ameliorate atherosclerosis. Human pharmacokinetic data indicate a very short plasma half-life of circulating hyaluronidase activity, suggesting that any systemic enzymatic effect is brief. Nevertheless, the biological consequences of repeated degradation–regeneration cycles, especially in high-risk states such as diabetes, inflammation, oxidative stress, or chronic kidney disease, remain incompletely understood. Evidence supporting clinical benefit in atherosclerosis is currently limited to heterogeneous animal experiments, historical uncontrolled reports, and a small number of anecdotal case observations, whereas randomized trials have only been performed in other settings such as acute myocardial infarction and do not establish efficacy for plaque regression. We therefore provide a balanced evaluation of knowns, uncertainties, alternative interpretations, potential risks, dosing unknowns, and a translational research agenda including mechanistic preclinical studies, biomarker development, imaging, and carefully designed early-phase clinical investigation. Full article

Hyaluronan (HA) is a major extracellular matrix glycosaminoglycan essential for tissue integrity, immune homeostasis, and host defense. Many microbial pathogens exploit host HA by producing hyaluronidases (Hyls), enzymes that degrade HA to promote tissue invasion, nutrient acquisition, immune modulation, and biofilm formation. Unlike mammalian Hyls, microbial Hyls predominantly function as β-elimination lyases, generating unsaturated disaccharides and oligosaccharides with distinct biological activities. Recent mechanistic and structural insights reveal that distinct microbial Hyl variants uniquely shape host–microbe interactions and disease outcomes. This review focuses on microbial Hyls, specifically bacterial Hyls, emphasizing their roles in host immune regulation and inflammatory diseases, particularly in Cutibacterium acnes-mediated acne pathogenesis. We also discuss emerging therapeutic strategies targeting the HA-Hyl axis to modulate inflammation, highlighting their potential as a foundation for novel human therapeutics. Full article

Injectable skin boosters currently in use mainly provide short-lived volumization or depend on inflammation-mediated collagen stimulation, raising concerns regarding durability and safety. Injectable particulate human acellular dermal matrix (phADM) is a biologically derived extracellular matrix scaffold designed to support constructive dermis remodeling. This randomized, split-face, double-blinded clinical trial evaluated the efficacy of phADM as a facial skin booster in 20 adults with moderate cheek roughness. phADM was injected on one facial side, with hyaluronic acid serving as the contralateral control. Multiple skin parameters were assessed over 20 weeks using validated imaging and biophysical instruments. Mechanistic validation was conducted using complementary in vitro, ex vivo human skin, and in vivo rat models. Clinically, the phADM-treated side demonstrated greater improvements in skin density, volume, elasticity, wrinkle depth, pore area, hydration, and barrier-related parameters at multiple time points compared with HA. In ex vivo human skin, phADM showed homogeneous dermal distribution and preservation of extracellular matrix architecture, along with restoration of basement membrane-associated proteins following UVB irradiation. In vivo rat studies revealed fibroblast infiltration and localized neocollagenesis within the implanted matrix. In vitro assays further indicated enhanced fibroblast proliferation and extracellular matrix synthesis, increased hyaluronan production, suppression of pro-inflammatory cytokines in activated macrophages, and downregulation of melanogenesis-related genes in melanoma cells. No serious adverse events were observed during the clinical study. These findings indicate that phADM functions as a restorative skin booster that promotes durable dermis remodeling and functional rejuvenation with a favorable safety profile. Full article

Glioblastoma (GBM) is an extremely aggressive and incurable primary tumor of the brain. GBM is characterized by interpatient and intratumoral heterogeneity, making this cancer particularly resistant to therapy and likely to recur. Mapping the complex dynamics that underpin the development and evolution of gliomas with human-based in vitro models is difficult. This study aimed to generate 3D glioma patient-derived tumor constructs (PTCs) using a clinically relevant, Matrigel-free, hyaluronic acid system, evaluate their suitability in drug screening assays, and determine the stability of their genetic profiles compared to originating tumors. In this study, we utilized a synthetically modified hyaluronic acid and gelatin hydrogel system to generate tumor constructs containing cells from clinical glioma biospecimens. PTCs were characterized phenotypically, after which they were deployed in chemotherapy drug screens using temozolomide (TMZ) and a P53 activator compound. Drug responses of these 3D cultures were compared with 2D cultures, as well as PTCs that were generated after passaging in 2D. RNA sequencing was used to evaluate genetic parity between PTCs or 2D cultures with originating tumor tissues, using The Cancer Genome Atlas (TCGA) GBM subpopulations for subcategorizing. PTCs were created successfully from five World Health Organization (WHO) grade 4, two grade 3, and two grade 2 gliomas. PTCs were maintained with high viability. Chemotherapy drug screens demonstrated that expected TMZ responses were observed for Isocitrate dehydrogenase (IDH) mutant diffuse gliomas while drug response was variable for IDH wildtype GBM PTCs. PTCs demonstrated stable drug response over time, while 2D passaging resulted in significant shifts in drug sensitivity. RNA sequencing revealed maintenance of subpopulation signatures for PTCs which clustered with their originating patient tumor tissue. In contrast, 2D cultures largely clustered together regardless of the patient. Our PTC approach utilizes a defined hydrogel biomaterial system that maintains the genotypic and drug response characteristics of patient tumors making this an ideal ex vivo model for translational applications. Full article

This narrative review outlines the structure and essential functions of ocular proteoglycans (PGs) in visual processing as documented in the extensive literature on this subject matter. The eye, as one of the most complex sensory organs, relies on the coordinated activity of various tissues and cell types, with PGs playing a central role in facilitating communication and maintaining tissue function. These molecules stabilise ocular tissues; for example, SPACRCAN (IMPG2) and hyaluronan aggregates in the interphotoreceptor matrix protect photoreceptors from oxidative stress. Specialised heparan sulfate PGs, such as pikachurin, eyes-shut, and the neurexin family, stabilise synapses and ensure synaptic specificity and plasticity. Pikachurin is particularly important for the rapid transmission of visual signals at the bipolar ribbon synapse. A diverse array of chondroitin sulfate (aggrecan, versican, neurocan, brevican, phosphacan, NG2), keratan sulfate (SV2), and heparan sulfate (perlecan, agrin, collagen XVIII) PGs are differentially expressed in ocular tissues, contributing to tissue stability and homeostasis. In the cornea, sclera, and choroid, small leucine-rich repeat PGs (SLRPs) maintain three-dimensional structure, corneal transparency, and tissue function through interactions with cytokines and growth factors. The vitreous humour contains opticin and nyctalopin, which support the nutrition of avascular regions and facilitate bipolar ribbon synapse signalling. Ultimately, the effectiveness of the eye as a visual organ depends significantly on the functional roles of its constituent PGs. Full article

Background: Fructans are fructose-based polysaccharides with diverse biological activities; however, their direct activity on skin cells remains unresolved. This study investigated the biological activity of fructan extracted from rakkyo (Allium chinense) (RF) and examined its effects on extracellular matrix (ECM) metabolism, particularly collagen and hyaluronan synthesis, in human dermal fibroblasts. Methods: RF was prepared from fresh rakkyo bulbs by aqueous extraction, alkaline clarification, and membrane filtration. The average molecular weight and structural characteristics of RF were analyzed using size-exclusion chromatography and ¹³C NMR spectroscopy. Normal human dermal fibroblasts (NHDFs) were treated with RF by culturing cells in RF-supplemented medium (0.1–1.0 mg/mL). Cell viability and viable cell number were evaluated using the thiazolyl blue tetrazolium bromide and trypan blue exclusion assays, respectively. Expression of ECM-related genes was analyzed by qRT-PCR, and collagen and hyaluronan production were quantified by Sirius Red staining and ELISA. Results: RF had an average molecular weight of approximately 11,500 Da and consisted of nearly equal proportions of inulin- and levan-type fructans. RF (≤1 mg/mL) increased the number of viable cells and markedly upregulated collagen, type I, alpha 1 (COL1A1) and hyaluronic acid synthase 2 (HAS2) expression while downregulating Hyal1 expression. After 9 days of treatment, the cumulative production of type I collagen and hyaluronic acid increased by 3.8- and 1.3-fold, respectively, as compared with controls. Upregulation of lysyl oxidase (LOX) mRNA suggested enhanced collagen cross-linking, whereas MMP-1 showed only modest induction. Conclusions: Rakkyo-derived fructan directly stimulates collagen and hyaluronan synthesis in dermal fibroblasts, likely through regulation of ECM-related genes. These results suggest that rakkyo-derived fructan modulates ECM-related readouts in NHDFs under controlled in vitro conditions. Further validation in more complex skin models and in vivo studies is necessary. Full article

Glycosylation depends on luminal nucleotide sugars delivered by solute carrier 35 (SLC35) transporters. SLC35A3 is a uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) transporter. In humans, biallelic mutations in SLC35A3 cause arthrogryposis, mental retardation, and seizures (AMRS). To define how loss of SLC35A3 function reshapes the neural glycome, we profiled N-, O-, and glycosaminoglycans (GAGs) in Slc35a3 knockout mouse brains. N- and O-glycans were analyzed by MALDI-TOF MS, and GAG disaccharides were quantified by anion-exchange HPLC. Knockout mouse brains exhibited attenuation of complex-type N-glycans with a reciprocal rise in high-mannose species, as revealed by MALDI-TOF MS profiling. In contrast, ConA lectin blotting showed no significant change, consistent with its preferential detection of mannose-rich glycans. Branching analysis revealed loss of tri- and tetra-antennary structures compared with biantennary species. O-glycan profiling showed core-2-type species (Hex₂HexNAc₂ backbone) decreased. The dominant disialyl core-1 remained stable. Total GAG output (chondroitin/dermatan sulfate, heparan sulfate, and hyaluronan) was preserved. These findings support a microdomain model in which SLC35A3 acts as a locally effective supplier of UDP-GlcNAc to MGAT4 (branching N-acetylglucosaminyltransferase that installs the β1,4-GlcNAc arm) in the brain, while alternative routes buffer UDP-GlcNAc delivery for GAG and mucin-type O-glycan biosynthesis. Accordingly, AMRS may be attributed to impaired higher-order N-glycan branching in the brain. Full article

Background: Stromal hyaluronic acid (HA) poses a physical barrier and protects tumor cells from immune surveillance. Stroma targeting with pegylated human recombinant PH20 hyaluronidase (PEGPH20) demonstrated improved infiltration of cytotoxic T-lymphocytes and delivery of chemotherapy and PD1/PD-L1 antibodies in tumor models. This multicenter phase II study of PEGPH20 plus pembrolizumab evaluated the efficacy, safety and immune and stromal biomarkers in patients with HA-high refractory metastatic pancreatic ductal adenocarcinoma (mPDA). Patients and Methods: Patients were treated with PEGPH20 3 µg/kg IV weekly and pembrolizumab 200 mg IV in 3-week cycles. Tumor and blood samples were collected at baseline and on-study for biomarker analyses. Results: Between May and November 2019, 38 patients were screened and 8 treated, with median age 68 years (range 60–73) and median two (range 1–4) prior therapies. The study was closed to accrual early by pharmaceutical sponsor. Treatment was well tolerated, with expected grade 1/2 musculoskeletal toxicities. Best response was stable disease in 2 of 7 evaluable patients (29%). Median overall and progression-free survival were 7.2 months (95% CI 1.2–11.8) and 1.5 months (95% CI 0.9–4.4), respectively. Prolonged survival (range 10.2–27.6 months) occurred in patients treated with subsequent chemotherapy. Higher baseline tumor T cell receptor (TCR) clonality correlated with longer survival. Conclusions: Pembrolizumab with PEGPH20 was safe but did not have significant efficacy in refractory HA-high metastatic PDA. Full article

Background: Multiple sclerosis (MS) is a neuroinflammatory disease characterized by autoimmune-driven inflammation in the central nervous system that damages axons and destroys myelin. It is difficult to diagnose multiple sclerosis due to its complexity, and different people may react differently to different treatments. While the exact cause of multiple sclerosis (MS) and the reasons for its increasing prevalence remain unclear, it is widely believed that a combination of genetic predisposition and environmental influences plays a significant role. Methods: Finding biomarkers for complicated diseases like multiple sclerosis (MS) is made more promising by the emergence of network and system biology technologies. Currently, using tools like Network Analyst to apply network-based gene expression profiling provides a novel approach to finding potential medication targets followed by molecular docking and MD Simulations. Results: There were 1200 genes found to be differentially expressed, with CD44 showing the highest degree score of 15, followed by CDC42 and SNAP25 genes, each with a degree score of 14. To explore the regulatory kinases involved in the protein–protein interaction network, we utilized the X2K online tool. The present study examines the binding interactions and the dynamic stability of four ligands (Obeticholic acid, Chlordiazepoxide, Dextromethorphan, and Hyaluronic acid) in the Hyaluronan binding site of the human CD44 receptor using molecular docking and molecular dynamics (MD) simulations. Docking studies demonstrated a significant docking score for Obeticholic acid (−6.3 kcal/mol), underscoring its medicinal potential. MD simulations conducted over a 100 ns period corroborated these results, revealing negligible structural aberrations (RMSD 1.3 Å) and consistent residue flexibility (RMSF 0.7 Å). Comparative examinations of RMSD, RMSF, Rg, and β-factor indicated that Obeticholic acid exhibited enhanced stability and compactness, establishing it as the most promising choice. Conclusions: This integrated method underscores the significance of dynamic validations for dependable drug design aimed at CD44 receptor-mediated pathways. Future experimental techniques are anticipated to further hone these findings, which further advance our understanding of putative biomarkers in multiple sclerosis (MS). Full article

Understanding how inner development capacities are embodied at biological levels remains an underexplored dimension of planetary health research. The aim of this viewpoint is to provide transdisciplinary integration across neuroscience, cell biology, education, and social systems toward addressing planetary health challenges. Despite growing recognition of the Inner Development Goals (IDG) framework as complementary to the UN Sustainable Development Goals, the biophysical dynamics underlying personal and collective transformation remain largely unexplored. This viewpoint presents key molecular pathways that may underpin the Embodied Neuroplastic Resilience Model (ENRM) via calcium signaling and hyaluronan (the CHA axis). This viewpoint explores educational and therapeutic implications while simultaneously illuminating how socioeconomic inequalities constrain access to neuroplasticity-supporting practices. Four key conclusions emerge: (1) The CHA axis provides a compelling mechanistic framework for understanding how bodily experiences can reshape neural circuits through calcium signaling and hyaluronic acid matrix dynamics; (2) Mapping molecular mechanisms to complex human inner development capacities remains provisional, requiring further interdisciplinary investigation; (3) Socioeconomic inequality creates structural barriers to neuroplasticity and inner development, necessitating an integrated approach that connects mechanistic understanding with equitable access to transformative practices; (4) Enhanced understanding of embodied neuroplasticity must serve compassion and systemic transformation, moving beyond individual optimization toward collective well-being. By bridging neuroscience and sustainability frameworks, this viewpoint calls for a nuanced understanding of inner development that transcends individual optimization and emphasizes collective transformation. Full article

Skin photoaging, marked by structural and functional changes, is mainly caused by long-term ultraviolet (UV) exposure. This study sought to create hydroxytyrosol (HT)-loaded soluble microneedles (HT MNs) and thoroughly assess their anti-photoaging effects and underlying mechanisms in vitro and in vivo. The optimized HT MNs, featuring tips with 10% HT + 5% hyaluronic acid (HA) and a backing layer of 10% polyvinyl pyrrolidone (PVP), demonstrated robust mechanical strength (withstanding an axial force of 10 N without fracture), adequate penetration depth (>200 μm), and efficient skin self-recovery post-removal. In vitro, HT MNs notably boosted cell viability, reduced reactive oxygen species (ROS) levels, and suppressed senescence-associated β-galactosidase (A-β-Gal) expression in UVA-exposed human skin fibroblasts (HSF). In vivo, in a UVA + UVB-irradiated mouse model, HT MNs significantly enhanced skin hydration and elasticity, increased collagen density (confirmed by Masson staining), decreased malondialdehyde (MDA) content, and elevated the activities of glutathione (GSH), catalase (CAT), and glutathione peroxidase (GSH-Px). Western blot analysis further revealed that HT MNs upregulated the expression of collagen type I alpha 1 (COL1A1), elastin (ELN), hyaluronan synthase 2 (HAS2), and filaggrin (FLG), while downregulating matrix metalloproteinase 1. Overall, these findings suggest that HT MNs effectively mitigate UV-induced photoaging through antioxidant, anti-senescence, and extracellular matrix (ECM)-regulating mechanisms, underscoring their potential as a novel transdermal anti-photoaging therapy. Full article