Effect of bioactive glass air-abrasion on the wettability and osteoblast proliferation on sandblasted and acid-etched titanium surfaces

The aim of this study was to evaluate the hydrophilicity, surface free energy, and proliferation and viability of human osteoblast-like MC3T3-E1 cells on sandblasted and acid-etched titanium surfaces after air-abrasion with 45S5 bioactive glass, zinc-containing bioactive glass, or inert glass. Sandblasted and acid-etched titanium discs were subjected to air-abrasion with 45S5 bioactive glass, experimental bioactive glass (Zn4), or inert glass. Water contact angles and surface free energy were evaluated. The surfaces were studied with preosteoblastic MC3T3-E1 cells. Air-abrasion with either type of glass significantly enhanced the hydrophilicity and surface free energy of the sandblasted and acid-etched titanium discs. The MC3T3-E1 cell number was higher for substrates air-abraded with Zn4 bioactive glass and similar to that observed on borosilicate coverslips (controls). Confocal laser scanning microscopy images showed that MC3T3-E1 cells did not spread as extensively on the sandblasted and acid-etched and bioactive glass-abraded surfaces as they did on control surfaces. However, for 45S5- and Zn4-treated samples, the cells spread most at the 24 h time point and changed their morphology to more spindle-like when cultured further. Air-abrasion with bioactive glass and inert glass was shown to have a significant effect on the wettability and surface free energy of the surfaces under investigation. Osteoblast cell proliferation on sandblasted and acid-etched titanium discs was enhanced by air-abrasion with 45S5 bioactive glass and experimental Zn4 bioactive glass compared with air-abrasion with inert glass or no air-abrasion

Mitogen-activated protein kinase (MAPK) pathway regulates branching by remodeling epithelial cell adhesion : MAPK Activity Controls Epithelial Adhesion In Vivo

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Targeting beta 1-integrin inhibits vascular leakage in endotoxemia

Loss of endothelial integrity promotes capillary leakage in numerous diseases, including sepsis, but there are no effective therapies for preserving endothelial barrier function. Angiopoietin-2 (ANGPT2) is a context-dependent regulator of vascular leakage that signals via both endothelial TEK receptor tyrosine kinase (TIE2) and integrins. Here, we show that antibodies against beta 1-integrin decrease LPS-induced vascular leakage in murine endotoxemia, as either a preventative or an intervention therapy. beta 1-integrin inhibiting antibodies bound to the vascular endotheliumin vivo improved the integrity of endothelial cell-cell junctions and protected mice from endotoxemia-associated cardiac failure, without affecting endothelial inflammation, serum proinflammatory cytokine levels, or TIE receptor signaling. Moreover, conditional deletion of a single allele of endothelial beta 1-integrin protected mice from LPS-induced vascular leakage. In endothelial mono-layers, the inflammatory agents thrombin, lipopolysaccharide (LPS), and IL-1 beta decreased junctional vascular endothelial (VE)-cadherin and induced actin stress fibers via beta 1- and alpha 5-integrins and ANGPT2. Additionally, beta 1-integrin inhibiting antibodies prevented inflammation-induced endothelial cell contractility and monolayer permeability. Mechanistically, the inflammatory agents stimulated ANGPT2-dependent translocation of alpha 5 beta 1-integrin into tensin-1-positive fibrillar adhesions, which destabilized the endothelial monolayer. Thus, beta 1-integrin promotes endothelial barrier disruption during inflammation, and targeting beta 1-integrin signaling could serve as a novel means of blocking pathological vascular leak.Peer reviewe

The critical effects of matrices on cultured carcinoma cells : Human tumor-derived matrix promotes cell invasive properties

The interaction between squamous cell carcinoma (SCC) cells and the tumor microenvironment (TME) plays a major role in cancer progression. Therefore, understanding the TME is essential for the development of cancer therapies. We used four (primary and metastatic) head and neck (HN) SCC cell lines and cultured them on top of or within 5 matrices (mouse sarcoma-derived Matrigel (R), rat collagen, human leiomyoma-derived Myogel, human fibronectin and human fibrin). We performed several assays to study the effects of these matrices on the HNSCC behavior, such as proliferation, migration, and invasion, as well as cell morphology, and molecular gene profile. Carcinoma cells exhibited different growth patterns depending on the matrix. While fibrin enhanced the proliferation of all the cell lines, collagen did not. The effects of the matrices on cancer cell migration were cell line dependent. Carcinoma cells in Myogel-collagen invaded faster in scratch wound invasion assay. On the other hand, in the spheroid invasion assay, three out of four cell lines invaded faster in Myogel-fibrin. These matrices significantly affected hundreds of genes and a number of pathways, but the effects were cell line dependent. The matrix type played a major role in HNSCC cell phenotype. The effects of the ECMs were either constant, or cell line dependent. Based on these results, we suggest to select the most suitable matrix, which provides the closest condition to the in vivo TME, in order to get reliable results in in vitro experiments.Peer reviewe

Aging and serum exomiR content in women-effects of estrogenic hormone replacement therapy

Exosomes participate in intercellular messaging by transporting bioactive lipid-, protein-and RNA-molecules and -complexes. The contents of the exosomes reflect the physiological status of an individual making exosomes promising targets for biomarker analyses. In the present study we extracted exosome microRNAs (exomiRs) from serum samples of premenopausal women (n = 8) and monozygotic postmenopausal twins (n = 10 female pairs), discordant for the use of estrogenic hormone replacement therapy (HRT), in order to see whether the age or/and the use of HRT associates with exomiR content. A total of 241 exomiRs were detected by next generation sequencing, 10 showing age, 14 HRT and 10 age + HRT-related differences. When comparing the groups, differentially expressed miRs were predicted to affect cell proliferation processes showing inactivation with younger age and HRT usage. MiR-106-5p, -148a-3p, -27-3p, -126-5p, -28-3p and -30a-5p were significantly associated with serum 17 beta-estradiol. MiRs formed two hierarchical clusters being indicative of positive or negative health outcomes involving associations with body composition, serum 17 beta-estradiol, fat-, glucose-and inflammatory markers. Circulating exomiR clusters, obtained by NGS, could be used as indicators of metabolic and inflammatory status affected by hormonal changes at menopause. Furthermore, the individual effects of HRT-usage could be evaluated based on the serum exomiR signature.Peer reviewe

Feasibility of mechanical extrusion to coat nanoparticles with extracellular vesicle membranes

Biomimetic functionalization to confer stealth and targeting properties to nanoparticles is a field of intense study. Extracellular vesicles (EV), sub-micron delivery vehicles for intercellular communication, have unique characteristics for drug delivery. We investigated the top-down functionalization of gold nanoparticles with extracellular vesicle membranes, including both lipids and associated membrane proteins, through mechanical extrusion. EV surface-exposed membrane proteins were confirmed to help avoid unwanted elimination by macrophages, while improving autologous uptake. EV membrane morphology, protein composition and orientation were found to be unaffected by mechanical extrusion. We implemented complementary EV characterization methods, including transmission- and immune-electron microscopy, and nanoparticle tracking analysis, to verify membrane coating, size and zeta potential of the EV membrane-cloaked nanoparticles. While successful EV membrane coating of the gold nanoparticles resulted in lower macrophage uptake, low yield was found to be a significant downside of the extrusion approach. Our data incentivize more research to leverage EV membrane biomimicking as a unique drug delivery approach in the near future

Dynamic MAPK/ERK Activity Sustains Nephron Progenitors through Niche Regulation and Primes Precursors for Differentiation

The in vivo niche and basic cellular properties of nephron progenitors are poorly described. Here we studied the cellular organization and function of the MAPK/ERK pathway in nephron progenitors. Live-imaging of ERK activity by a Forster resonance energy transfer biosensor revealed a dynamic activation pattern in progenitors, whereas differentiating precursors exhibited sustained activity. Genetic experiments demonstrate that MAPK/ERK activity controls the thickness, coherence, and integrity of the nephron progenitor niche. Molecularly, MAPK/ERK activity regulates niche organization and communication with extracellular matrix through PAX2 and ITGA8, and is needed for CITED1 expression denoting undifferentiated status. MAPK/ERK activation in nephron precursors propels differentiation by priming cells for distal and proximal fates induced by the Wnt and Notch pathways. Thus, our results demonstrate a mechanism through which MAPK/ERK activity controls both progenitor maintenance and differentiation by regulating a distinct set of targets, which maintain the biomechanical milieu of tissue-residing progenitors and prime precursors for nephrogenesis.Peer reviewe

Functional human cell-based vascularised cardiac tissue model for biomedical research and testing

Cardiomyocytes derived from human induced pluripotent stem cells (hiPSC) are widely used in in vitro biomedical research and testing. However, fully matured, adult cardiomyocyte characteristics have not been achieved. To improve the maturity and physiological relevance of hiPSC-derived cardiomyocytes, we co-cultured them with preconstructed vascular-like networks to form a functional, human cell-based cardiac tissue model. The morphology and gene expression profiles indicated advanced maturation in the cardiac tissue model compared to those of a cardiomyocyte monoculture. The cardiac tissue model’s functionality was confirmed by measuring the effects of 32 compounds with multielectrode array and comparing results to human data. Our model predicted the cardiac effects with a predictive accuracy of 91%, sensitivity of 90% and specificity of 100%. The correlation between the effective concentration (EC50) and the reported clinical plasma concentrations was 0.952 (R2 = 0.905). The developed advanced human cell-based cardiac tissue model showed characteristics and functionality of human cardiac tissue enabling accurate transferability of gained in vitro data to human settings. The model is standardized and thus, it would be highly useful in biomedical research and cardiotoxicity testing.publishedVersionPeer reviewe

Increased levels of systemic LPS-positive bacterial extracellular vesicles in patients with intestinal barrier dysfunction

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