Extracellular Matrix Structure and Interaction with Immune Cells in Adult Astrocytic Tumors.

The extracellular matrix (ECM) is a dynamic set of molecules produced by the cellular component of normal and pathological tissues of the embryo and adult. ECM acts as critical regulator in various biological processes such as differentiation, cell proliferation, angiogenesis, and immune control. The most frequent primary brain tumors are gliomas and by far the majority are adult astrocytic tumors (AATs). The prognosis for patients with these neoplasms is poor and the treatments modestly improves survival. In the literature, there is a fair number of studies concerning the composition of the ECM in AATs, while the number of studies relating the composition of the ECM with the immune regulation is smaller. Circulating ECM proteins have emerged as a promising biomarker that reflect the general immune landscape of tumor microenvironment and may represent a useful tool in assessing disease activity. Given the importance it can have for therapeutic and prognostic purposes, the aim of our study is to summarize the biological properties of ECM components and their effects on the tumor microenvironment and to provide an overview of the interactions between major ECM proteins and immune cells in AATs. As the field of immunotherapy in glioma is quickly expanding, we retain that current data together with future studies on ECM organization and functions in glioma will provide important insights into the tuning of immunotherapeutic approaches.

Food Safety Assessment and Nutraceutical Outcomes of Dairy By-Products: Ovine Milk Whey as Wound Repair Enhancer on Injured Human Primary Gingival Fibroblasts.

The valorization of milk whey appears to be a promising strategy for managing by-products from dairy food industries, which incur demanding economic costs for treatment and/or disposal. Thanks to its numerous bioactive components, whey is expected to be increasingly incorporated into foods in the future. We investigated the safety of ovine milk whey through in vitro experiments on human primary gingival fibroblast (HGF-1) proliferation and wound healing. Fibroblasts play a crucial role in the repair processes from the late inflammatory phase until the final stages. Cells treated with varying concentrations of ovine whey (0.01%, 0.1%, 1%, and 10%) were able to close wounds more rapidly than vehicle-treated cells. Time- and dose-dependent responses were observed in cell populations exposed to ovine whey. Specifically, wounds treated with 0.1% and 10% milk whey showed better migratory capabilities compared to those treated with 0.01% and 1% milk whey after 24 and 48 h. In addition, ovine milk whey stimulates extracellular matrix deposition, as evidenced by the increasing levels of CD44 antigen density evaluated through FACS analysis, as well as COL1A1 expression measured both via RT-qPCR and immunofluorescence. This phenomenon was particularly evident at concentrations of 0.01% and 10%. Ensuring quality and safety has become a major concern for health authorities in the food industry. Our findings suggest that ovine milk whey is safe and possesses regenerative properties. It facilitates tissue re-establishment following exposure to environmental stress, particularly accelerating gingival wound closure.

Novel insights into the pharmacological modulation of human periodontal ligament stem cells by the amino-bisphosphonate Alendronate.

Alendronate (ALN) is a second-generation bisphosphonate widely used for osteoporosis and cancer-induced bone lesions. Many studies have confirmed a strong relationship between osteonecrosis of the jaws (ONJ) development and oral bisphosphonates, especially ALN, although the molecular mechanisms underlying this pathology have not yet been elucidated. The reduction in bone turnover and vascularization usually observed in ONJ are the result of ALN action on different cell types harboured in oral microenvironment, such as osteoclasts, endothelial cells, and periodontal ligament stem cells (PDLSCs). In this perspective, the present study aims to investigate the effects of different ALN concentrations (2 µM, 5 µM, 10 µM, 25 µM, 50 µM) on the phenotype and functional properties of human PDLSCs (hPDLSCs). hPDLSCs showed a decrease in cell viability (MTT assay) only when treated with ALN concentration of 10 µM or larger for 48 h and 72 h. Cell cycle analysis revealed a moderate increase in proportion of S-phase cells after exposure to low ALN concentration (2-5 µM), an effect that was reverted after exposure to 10-50 µM ALN. Conversely, cell death was evidenced via Annexin V/PI assay at very high concentration of ALN (50 µM) after 4 days of treatment. In addition, we explored whether the effects of ALN on hPDLSCs growth and survival can be mediated by its ability to modulate oxidative stress. To this, we quantified the intracellular ROS amount and lipid peroxidation by using DCF probe and Bodipy staining, respectively. Flow cytometry analysis showed that ALN induced a dose-dependent reduction of intracellular oxidative stress and lipid peroxidation upon treatment with low concentrations at both 48 h and 72 h. Increased levels of oxidative stress was reported at 50 µM ALN and was also confirmed via TEM analysis. Despite the stability of the cellular immunophenotype, hPDLSCs showed impaired mobility after ALN exposure. Chronic exposure (7-14 days) to ALN in the range of 2-10 µM significantly decreased the expression of the differentiation-related factors ALP, RUNX2, COLI, and OPN as well as the osteogenic ability of hPDLSCs compared with untreated cells. Conversely, higher doses were found to be neutral. Our findings indicated that the effects of ALN on hPDLSCs behavior are dose-dependent and suggest a role for oxidative stress in ALN-induced cell death that may lead to novel therapeutic approaches for ONJ.

Utilization of Dairy By-Products as a Source of Functional and Health Compounds-The Role of Ovine Colostrum and Milk Whey on Chronic Myeloid Leukemia Cells.

Nowadays, the search for food products that promote consumers' health has gained interest, and dairy by-products, due to their biological quality, could have a prominent position among products with health benefits. However, little is known about their activity on cancer cells. This study aimed to provide evidence about the effect of ovine colostrum and milk whey on K562 cells, a model of the human chronic myeloid leukemia cell line. The exposure of K562 cells to a single administration of sheep by-products at different concentrations for three days and three treatments for three days was carried out. Using a flow cytometric approach, we found that CD235a expression remained stable in the cells exposed to ovine whey (milk and colostrum) at concentrations ranging from 1 ng/mL to 100 µg/mL, after three days from one or three administrations, respectively. A significant reduction in fluorescent cells was observed in the populations exposed to 1 mg/mL of both milk and colostrum at the same time points. In these conditions, the size and granularity of the leukemic cells also changed, with a substantial reduction in the number of actively dividing cells in the S phase of the cell cycle. This phenomenon was highlighted by the Annexin V/PI cytofluorimetric test, which is able to provide quantitative results regarding the population of cells in early or late apoptosis or necrotic cells after exposure to a single dose or three doses of colostrum or sheep whey for three days, respectively. This report showed that both colostrum and milk whey were able to modify the phenotypic profile and cell cycle of the K562 cell line, inducing apoptosis at the highest concentration.

A Review of Novel Strategies for Human Periodontal Ligament Stem Cell Ex Vivo Expansion: Are They an Evidence-Based Promise for Regenerative Periodontal Therapy?

Periodontitis is a gingiva disease sustained by microbially associated and host-mediated inflammation that results in the loss of the connective periodontal tissues, including periodontal ligament and alveolar bone. Symptoms include swollen gingiva, tooth loss and, ultimately, ineffective mastication. Clinicians utilize regenerative techniques to rebuild and recover damaged periodontal tissues, especially in advanced periodontitis. Human periodontal ligament stem cells (hPDLSCs) are considered an appealing source of stem cells for regenerative therapy in periodontium. hPDLSCs manifest the main properties of mesenchymal stem cells, including the ability to self-renew and to differentiate in mesodermal cells. Significant progress has been made for clinical application of hPDLSCs; nevertheless, some problems remain, including the small number of cells isolated from each sample. In recent decades, hPDLSC ex vivo expansion and differentiation have been improved by modifying cell culture conditions, especially with the supplementation of cytokines' or growth factors' mix, chemicals, and natural compounds, or by using the decellularized extracellular matrix. Here, we analyzed the changes in stemness properties and differentiation potential of hPDLSCs when culturing in alternative media. In addition, we focused on the possibility of replacing FBS with human emoderivates to minimize the risks of xenoimmunization or zoonotic transmission when cells are expanded for therapeutic purposes.