Search Results (82)

Background: Advanced glycation end-products (AGEs) are formed and deposited in tissues, contributing to various disorders, including diabetes, other metabolic diseases, and aging. A new epitope, AGE10, was identified in human and animal tissues using a monoclonal antibody raised against synthetic melibiose-derived glycation end-products (MAGE), which were synthesized under anhydrous conditions with bovine serum albumin or myoglobin. The biology of the AGE10 epitope, particularly its role in diseases and in cancer tissues, is not well understood. Methods: The study was aimed at investigating the immunohistochemical recognition of AGE10 with the MoAb-anti-MAGE antibody. Results: Data obtained show that AGE10 is recognized in striated muscles but not in tumors of muscular origin. AGE10 is also stained in both normal and cancerous salivary glands and in adenomas of the large intestine. The staining is cytoplasmic. Discussion: Our approach may provide a methodology for cell biology research; AGE10 may be related to an advanced lipoxidation end-product; further investigation of MAGE may clarify disease mechanisms, support the development of novel therapeutic strategies. Conclusions: The key finding is that antibodies recognize mainly the epitope in epithelial and some mesenchymal tissues. Thus, the potential for AGE10 as a diagnostic marker is limited. The implications concern the biology of this epitope, the unique tissue distribution, and a role in cellular metabolism. Full article

Bioengineered functional salivary tissues can advance regenerative therapies, preclinical drug testing, and the fundamental understanding of salivary gland dysfunction. Current salivary tissue models are typically Matrigel-based, hydrogel-based or scaffold-free organoid systems, with limited physiological relevance or mimicry of cell-cell and cell-extracellular matrix (ECM) interactions. We previously developed elastin-alginate cryoelectrospun scaffolds (CES) that resemble the topography and viscoelastic properties of healthy salivary ECM, and validated their potential for stromal cell culture, delivery, and in vitro fibrosis modeling. Here, we evaluated the utility of CES to support 3D cocultures of salivary gland epithelial and mesenchymal cells in vitro. We compared CES with honeycomb-like topography (CES-H) to densely packed electrospun nanofibers (NFs) and CES with fibrous topography (CES-F) for their ability to support SIMS epithelial cell attachment, morphology, 3D clustering, phenotype and organization into distinct clusters when cocultured with stromal cells. Both CES-F and CES-H supported epithelial cell attachment and clustering; in particular, CES-H most effectively supported the self-organization of epithelial and stromal cells into distinct 3D clusters resembling the structure of native salivary tissue. Stromal cells were essential for maintaining the phenotype of epithelial cells cultured on CES-H, laying the foundation for the development of in vitro tissue models. Full article

Diabetes is a significant risk factor for bisphosphonate-related osteonecrosis of the jaw (BRONJ), a severe oral complication with limited treatment options. Salivary testing offers a noninvasive approach for monitoring BRONJ risk; however, few studies have investigated salivary biomarkers in BRONJ. This study screened salivary biomarkers that reflect the progression of BRONJ under diabetic conditions. A diabetic BRONJ rat model was established to screen for diabetes-related biochemical biomarkers in saliva. Streptozotocin (STZ) administration elevated blood glucose and glycated albumin levels and altered lipid and renal function markers, confirming diabetes induction. Subsequent zoledronic acid (ZA) administration and extraction of the maxillary first molar delayed epithelialization, inflammatory cell infiltration, bone exposure, and necrosis in extraction sockets, indicating successful establishment of a diabetic BRONJ model. This model showed reductions in submandibular and sublingual gland size, as well as in acinar cell number. Although salivary secretion volume was reduced, saliva samples were successfully collected from all groups. Screening identified elevated urea nitrogen (UN) and total ketone bodies (T-KB) in the STZ + ZA group. These findings suggest that salivary UN and T-KB may reflect disease progression and serve as potential biomarkers for predicting BRONJ risk under diabetic conditions. Full article

Background/Objectives: Salivary volatile organic compounds (VOCs) are promising noninvasive biomarkers for a wide range of diseases. While glandular saliva, secreted by salivary glands, is a relatively pure biofluid, whole saliva is a complex mixture containing oral microbiota, food debris, and desquamated epithelial cells. Therefore, a comprehensive comparison of the VOC profiles of these two types of saliva is essential to identify biologically relevant compounds. In this study, we aimed to establish a reliable method for VOC profiling from small saliva volumes and identify VOCs that reflect the biological differences between glandular and whole saliva. Methods: We developed a protocol combining MonoTrap extraction with dichloromethane, allowing the analysis of VOCs from just 100 µL of saliva. To address the issue of sampling-derived artifacts, we implemented a two-step blank analysis to systematically exclude compounds originating from the collection device. Results: Our analysis successfully identified a total of 72 VOCs. Following blank analysis, we systematically excluded 15 artifacts originating from the sampling device. Subsequent orthogonal partial least squares discriminant analysis (OPLS-DA) and Wilcoxon signed-rank test (using variable importance for prediction (VIP) > 1.0 and q < 0.05) identified 10 key VOCs that were significantly higher in whole saliva than in glandular saliva. These compounds included isobutyric acid, isovaleric acid, 4-methylvaleric acid, 3-phenylpropionic acid, indole, skatole, methyl mercaptan, 1-propanol, δ-valerolactam, and acetaldehyde. Most of these compounds originate from the metabolic activities of the oral microbiome, suggesting that the distinct VOC profile of whole saliva is predominantly influenced by microbial activity. Conclusions: Our findings demonstrated the effectiveness of this method for identifying biologically relevant VOCs from relatively small sample volumes. The identified VOC profiles highlight the contribution to the discovery of non-invasive biomarkers for oral health and serve as a solid foundation for future research into clinical applications. Full article

This study explores immunophenotypic and angiogenic profiles in salivary gland tumors (SGTs), focusing on epithelial–mesenchymal dynamics and immune–stromal interactions. Immunohistochemical analysis of E-cadherin, Vimentin, mast cell tryptase (MCT), CD300a, CK18, CD31, and vascular endothelial growth factor (VEGF) was performed in normal salivary tissue, pleomorphic adenomas (PA), and squamous cell carcinomas (SCCs) to assess epithelial plasticity, mast cell (MC) involvement, and vascular remodeling. Normal glands showed compartmentalized E-cadherin (epithelial) and Vimentin (mesenchymal) expression, with stromal MCs positive for MCT and CD300a. PA exhibited reduced E-cadherin, increased Vimentin, and atypical co-localization of CK18 with MCT/CD300a in ductal cells, indicating immune–epithelial plasticity. SCC displayed epithelial–mesenchymal transition (EMT), architectural disruption, and reduced MCT/CD300a. Notably, diminished MCT may reflect either decreased MCs density or prior degranulation, with possible diffuse MCT in stroma. Angiogenic profiling showed maximal CD31 in PA and minimal in SCC, while VEGF peaked in normal tissue, suggesting deregulated angiogenesis. SGT progression involves immune–epithelial plasticity, vascular deregulation, and stromal reprogramming. Immune marker localization within epithelial cells challenges histogenetic models and may inform prognostic assessment and targeted therapeutic strategies. Full article

Objectives: Lepidium meyenii Walpers (LMW), a high-altitude plant, is known to stimulate hormone release, counteract neurodegeneration, and protect against oxidative stress. Saliva is vital for oral health, and reduced production leads to xerostomia, often caused by aging, radiation, or Sjögren’s syndrome. Key pathological features include mesenchymal fibrosis and acinar atrophy, largely regulated by the TGF-β1 pathway. Current treatments are limited, with many patients relying on artificial saliva. Developing therapies to restore salivary function could offer significant benefits. Methods: In this study, we assessed the protective effects of LMW extract (LMWE) in irradiated C57BL/6J mice and TGF-β1-treated rat parotid acinar cells (Par-C10) using histological, molecular, bioenergetic, and 3D organoid analyses to evaluate salivary gland regeneration and lineage-specific differentiation. Results: LMWE significantly restored gland weight, shortened secretion lag time, and increased amylase activity in irradiated mice. Histological and molecular analyses showed reduced acinar atrophy and fibrosis, preservation of epithelial polarity, and upregulation of Mist1, AQP5, and amylase. In vitro, LMWE protected Par-C10 cells from TGF-β1-induced senescence, preserved mitochondrial membrane potential, and improved epithelial barrier function. In 3D organoid cultures of Par-C10 cells embedded in matrix, (1E,4Z)-1-(2,4-dihydroxyphenyl)-5-(3,4-dihydroxyphenyl) penta-1,4-dien-3-one (DHPPD) and (Z)-N-phenyldodec-2-enamide (E4Z-PD)-selectively enhanced acinar and ductal lineage differentiation, respectively. Conclusions: These results suggest that LMWE promotes salivary gland regeneration through antioxidative and lineage-specific mechanisms and may represent a safe and effective therapeutic strategy for xerostomia. Full article

Sjögren’s disease (SjD) is an autoimmune disease of exocrine tissues. Prior research has shown that ETS proto-oncogene 1 (ETS1), STAT1, and IL33 may contribute to the disease’s pathology. However, the regulatory mechanisms of these genes remain poorly characterized. Our objective was to explore the mechanisms of SjD pathology and to identify dysfunctional regulators of these genes by immunostimulation of SjD and sicca relevant cell lines. We used immortalized salivary gland epithelial cell lines (iSGECs) from Sjögren’s disease (pSS1) and sicca (nSS2) patients, previously developed in our lab, and control cell line A253 to dose with immunostimulants IFN-γ or poly(I:C) (0 to 1000 ng/mL and 0 to 1000 µg/mL, respectively) over a 72 h time course. Gene expression was determined using qRT-PCR delta-delta-CT method based on glyceraldehyde-3-phosphate dehydrogenase (GAPDH) for mRNA and U6 small nuclear RNA 1 (U6) for miRNA, using normalized relative fold changes 48 h post-immunostimulation. Protein expression was quantified 72 h post-stimulation by Western blotting. Reference-based RNA-seq of immunostimulated pSS1 and nSS2 cells was performed to characterize the reactome of genes conserved across all used doses. The expression of ETS1 and STAT1 protein was upregulated (p < 0.05) in IFN-γ-treated pSS1 and nSS2, as compared to A253 cells. IFN-γ-treated nSS2 cell showed significant IL33 upregulation. Also, IL33 had a correlated (p < 0.01) U-shaped response for low-mid-range doses for IFN-γ- and poly(I:C)-treated pSS1 cells. RNA-seq showed 175 conserved differentially expressed (DE) genes between nSS2 and pSS1 immunostimulated cells. Of these, 44 were shown to interact and 39 were more abundant (p < 0.05) in pSS1 cells. Western blotting demonstrated nSS2 cells expressing ETS1 uniformly across treatments compared to pSS1 cells, despite similar mRNA abundance. miR-145b and miR-193b were significantly under-expressed in IFN-γ-treated nSS2 cells compared to pSS1 cells (p < 0.01). ETS1 and IL33 showed disproportionate mRNA and protein abundances between immunostimulated Sjögren’s disease-derived (pSS1), and sicca-derived (nSS2) cell lines. Such differences could be explained by higher levels of miR-145b and miR-193b present in pSS1 cells. Also, RNA-seq results suggested an increased sensitivity of pSS1 cells to immunostimulation. These results reflect current pathobiology aspects, confirming the relevance of immortalized salivary gland epithelial cell lines. Full article

Three-dimensional (3D) spheroid cultures are crucial for modeling salivary gland (SG) morphogenesis and advancing regenerative medicine. This study evaluated the effects of varying ratios of mouse SG-derived epithelial cells co-cultured with human dermal fibroblasts (hDFs), identifying a 2:1 ratio (spheroids containing 67% EpCAM^pos cells with 33% hDFs) as optimal for preserving native SG-derived epithelial cell phenotypes. At this ratio, 67% EpCAM^pos spheroids maintained structural integrity and demonstrated a significant reduction in apoptosis and senescence markers, specifically, cleaved caspase-3 (Cc3) and Serpine1, alongside an enhanced expression of the progenitor marker Keratin 5 (KRT5). This highlights the pivotal role of fibroblasts in supporting epithelial cell function in 3D cultures. These spheroids provide a useful model for developing SG tissues that closely mimic physiological properties. Despite promising results, these findings are preliminary and require further validation under diverse conditions and across different SG models. Full article

Head and neck cancers (HNCs) arise from anatomically adjacent sites and subsites, with varying etiological factors, diagnostic strategies, prognoses, and treatment approaches. While conventional squamous cell carcinoma (SCC) is the most common histology in the head and neck district, HNCs encompass a variety of rare histopathological entities, categorized into epithelial tumors such as salivary gland cancers, sinonasal tumors, neuroendocrine tumors, malignant odontogenic tumors, and SCC variants versus non-epithelial tumors including soft tissue sarcomas, mucosal melanomas, and hematological malignancies. Rare HNCs (R-HNCs) represent a diagnostic and clinical challenge, requiring histopathological expertise, the availability of peculiar molecular analysis, and the personalization of local and systemic treatments, all guided by a multidisciplinary tumor board. Here, we provide a comprehensive literature review on R-HNCs, emphasizing key histopathological and molecular characteristics that are crucial for guiding treatment decisions. An insight about the latest developments in systemic treatments is also reported. Full article

In Sjögren’s disease (SjD), the salivary glandular epithelial cells can induce the chemotaxis of B cells by secreting B-cell chemokines such as C-X-C motif chemokine ligand 13 (CXCL13). Syndecan-1 (SDC-1) is a major transmembrane heparan sulfate proteoglycan (HSPG) predominantly expressed on epithelial cells that binds to and regulates heparan sulfate (HS)-binding molecules, including chemokines. We aimed to determine whether SDC-1 plays a role in the pathogenesis of SjD by acting on the binding of HS to B-cell chemokines. To assess changes in glandular inflammation and SDC-1 concentrations in the submandibular gland (SMG) and blood, female NOD/ShiLtJ and sex- and age-matched C57BL/10 mice were used. In the SMG of NOD/ShiLtJ mice, inflammatory responses were identified at 8 weeks of age, but increased SDC-1 concentrations in the SMG and blood were observed at 6 weeks of age, when inflammation had not yet started. As the inflammation of the SMG worsened, the SDC-1 concentrations in the SMG and blood increased. The expression of the CXCL13 and its receptor C-X-C chemokine receptor type 5 (CXCR5) began to increase in the SMG at 6 weeks of age and continued until 12 weeks of age. Immunofluorescence staining in SMG tissue and normal murine mammary gland cells confirmed the co-localization of SDC-1 and CXCL13, and SDC-1 formed a complex with CXCL13 in an immunoprecipitation assay. Furthermore, NOD/ShiLtJ mice were treated with 5 mg/kg HS intraperitoneally thrice per week for 6–10 weeks of age, and the therapeutic effects in the SMG were assessed at the end of 10 weeks of age. NOD/ShiLtJ mice treated with HS showed attenuated salivary gland inflammation with reduced B-cell infiltration, germinal center formation and CXCR5 expression. These findings suggest that SDC-1 plays a pivotal role in the pathogenesis of SjD by binding to CXCL13 through the HS chain. Full article

Head and neck cancers (HNCs) constitute a wide range of malignancies originating from the epithelial lining of the upper aerodigestive tract, including the oral cavity, pharynx, larynx, nasal cavity, paranasal sinuses, and salivary glands. Although lymphomas affecting this region are not conventionally classified as HNCs, they may occur in lymph nodes or mucosa-associated lymphoid tissues within the head and neck. Oncogenic viruses play a crucial role in HNC onset. Human papillomavirus (HPV) is extensively studied for its association with oropharyngeal cancers; nevertheless, other oncogenic viruses also contribute to HNC development. This review provides an overview of the epidemiology, pathogenesis, and advancements in detection methods of oncogenic viruses associated with HNCs, recognizing HPV’s well-established role while exploring additional viral connections. Notably, Epstein–Barr virus is linked to nasopharyngeal carcinoma and lymphomas. Human herpesvirus 8 is implicated in Kaposi’s sarcoma, and Merkel cell polyomavirus is associated with subsets of HNCs. Additionally, hepatitis viruses are examined for their potential association with HNCs. Understanding the viral contributions in the head and neck area is critical for refining therapeutic approaches. This review underlines the interaction between viruses and malignancies in this region, highlighting the necessity for ongoing research to elucidate additional mechanisms and enhance clinical outcomes. Full article

Sjögren’s syndrome is a multisystemic autoimmune disease that mainly affects the exocrine glands, causing dryness of the eyes and the mouth as the principal symptoms. Non-coding RNAs (ncRNAs), once regarded as genomic “junk”, are now appreciated as important molecular regulators of gene expression, not least in Sjögren’s syndrome and other autoimmune diseases. Here we review research into the causative roles of microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) on immunological responses, inflammation, and salivary gland epithelial cell function in Sjögren’s syndrome patients. These ncRNAs represent promising new therapeutic targets for treating the disease and possibly as biomarkers for early diagnosis. Full article

Elevated oxidative stress can play a pivotal role in autoimmune diseases by exacerbating inflammatory responses and tissue damage. In Sjögren’s disease (SjD), the contribution of oxidative stress in the disease pathogenesis remains unclear. To address this question, we created mice with a tamoxifen-inducible conditional knockout (KO) of a critical antioxidant enzyme, superoxide dismutase 2 (Sod2), in the salivary glands (i-sg-Sod2 KO mice). Following tamoxifen treatment, Sod2 deletion occurred primarily in the ductal epithelium, and the salivary glands showed a significant downregulation of Sod2 expression. At twelve weeks post-treatment, salivary glands from the i-sg-Sod2 KO mice exhibited increased 3-Nitrotyrosine staining. Bulk RNA-seq revealed alterations in gene expression pathways related to ribosome biogenesis, mitochondrial function, and oxidative phosphorylation. Significant changes were noted in genes characteristic of salivary gland ionocytes. The i-sg-Sod2 KO mice developed reversible glandular hypofunction. However, this functional loss was not accompanied by glandular lymphocytic foci or circulating anti-nuclear antibodies. These data demonstrate that although localized oxidative stress in salivary gland ductal cells was insufficient for SjD development, it induced glandular dysfunction. The i-sg-Sod2 KO mouse resembles patients classified as non-Sjögren’s sicca and will be a valuable model for deciphering oxidative-stress-mediated glandular dysfunction and recovery mechanisms. Full article

Sjögren’s Disease (SjD) is an autoimmune disease of the exocrine tissues. Etiological events result in the loss of epithelial homeostasis alongside extracellular matrix (ECM) destruction within the salivary and lacrimal glands, followed by immune cell infiltration. In this review, we have assessed the current understanding of epithelial–mesenchymal transition (EMT)-associated changes within the salivary epithelium potentially involved in salivary dysfunction and SjD pathogenesis. We performed a PubMed literature review pertaining to the determination of pathogenic events that lead to EMT-related epithelial dysfunction and signaling in SjD. Molecular patterns of epithelial dysfunction in SjD salivary glands share commonalities with EMT mediating wound healing. Pathological changes altering salivary gland integrity and function may precede direct immune involvement while perpetuating MMP9-mediated ECM destruction, inflammatory mediator expression, and eventual immune cell infiltration. Dysregulation of EMT-associated factors is present in the salivary epithelium of SjD and may be significant in initiating and perpetuating the disease. In this review, we further highlight the gap regarding mechanisms that drive epithelial dysfunction in salivary glands in the early or subclinical pre-lymphocytic infiltration stages of SjD. Full article

Our goal was to investigate the effects of epidermal growth factor (EGF) and interferons (IFNs) on signal transducer and activator of transcription STAT1 and STAT4 mRNA and active phosphorylated protein expression in Sjögren’s syndrome cell culture models. iSGECs (immortalized salivary gland epithelial cells) and A253 cells were treated with EGF, IFN-alpha, -beta, -gamma, or mitogen-activated protein kinase p38 alpha (p38-MAPK) inhibitor for 0–24–48–72 h. STAT1 and STAT4 mRNA expression was quantified by qRT-PCR. Untreated and treated cells were compared using the delta-delta-CT method based on glyceraldehyde-3-phosphate dehydrogenase (GAPDH) normalized relative fold changes. phospho-tyrosine-701-STAT1 and phospho-serine-721-STAT4 were detected by Western blot analysis. STAT4 mRNA expression decreased 48 h after EGF treatment in A253 cells, immortalized salivary gland epithelial cells iSGECs nSS2 (sicca patient origin), and iSGECs pSS1 (anti-SSA negative Sjögren’s Syndrome patient origin). EGF and p38-MAPK inhibitor decreased A253 STAT4 mRNA levels. EGF combined with IFN-gamma increased phospho-STAT4 and phospho-STAT1 after 72 h in all cell lines, suggesting additive effects for phospho-STAT4 and a major effect from IFN-gamma for phospho-STAT1. pSS1 and nSS2 cells responded differently to type I and type II interferons, confirming unique functional characteristics between iSGEC cell lines. EGF/Interferon related pathways might be targeted to regulate STAT1 and STAT4 expression in salivary gland epithelial cells. Further investigation is required learn how to better target the Janus kinases/signal transducer and activator of transcription proteins (JAK/STAT) pathway-mediated inflammatory response in Sjögren’s syndrome. Full article