NANOCRYSTALLINE HYDROXYAPATITE PREPARED AT DIFFERENT PRECURSOR CONCENTRATIONS: THERMAL STABILITY, MORPHOLOGY AND IN VITRO CELLULAR RESPONSE

Apoptosis, along with proliferation, is a form of lymphocyte response to activating stimuli. In the early stages of cell differentiation, the apoptotic response prevails and it results to the formation of tolerance to inductor antigen. Mature lymphocytes proliferate in response to stimulation and it means the initial stage in the development of the immune response. Since in this case apoptosis and proliferation acts as alternative processes, their ratio can serve as a measure of the effectiveness of the cellular response to activating signals. The resistance of autoreactive T-cells to apoptosis is the main key point in the development of type 1 diabetes mellitus (T1DM). Autoreactive T-cells migrates from the bloodstream to the islet tissue of the pancreas and take an active part in b cells destruction. The resistance of autoreactive effector T-cells to apoptosis may suggest their high proliferative potential. Therefore, the comparative evaluation of apoptosis and proliferation of peripheral blood lymphocytes can give a more complete picture of their functional state and thus will help to reveal the causes of ineffective peripheral blood T-ceiis apoptosis in patients with T1DM and will help to understand more deeply the pathogenesis of the disease. in this article, the features of proliferative response of peripheral blood T-cells in patients with T1DM and in individuals with high risk of developing T1DM have been studied. Apoptosis of T-cell subpopulations has been investigated. The correlation between the apoptotic markers and the intensity of spontaneous and activation- induced in vitro T-cells proliferation of was revealed. it was determined, that autoreactive peripheral blood T-cells were resistant to apoptosis and demonstrated the increased proliferative potential in patients with T1DM and in individuals with high risk of developing T1DM.

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Tetracalcium Phosphate/Monetite/Calcium Sulfate Hemihdrate Biocement Powder Mixtures Prepared by the One-Step Synthesis for Preparation of Nanocrystalline Hydroxyapatite Biocement-Properties and In Vitro Evaluation

Materials ◽

10.3390/ma14092137 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2137

Author(s):

Lubomir Medvecky ◽

Maria Giretova ◽

Radoslava Stulajterova ◽

Lenka Luptakova ◽

Tibor Sopcak

Keyword(s):

Simulated Body Fluid ◽

Body Fluid ◽

Calcium Sulfate ◽

Powder Mixtures ◽

Liquid Component ◽

Tetracalcium Phosphate ◽

Nanocrystalline Hydroxyapatite ◽

One Step ◽

Calcium Sulfate Hemihydrate

A modified one-step process was used to prepare tetracalcium phosphate/monetite/calcium sulfate hemihydrate powder cement mixtures (CAS). The procedure allowed the formation of monetite and calcium sulfate hemihydrate (CSH) in the form of nanoparticles. It was hypothesized that the presence of nanoCSH in small amounts enhances the in vitro bioactivity of CAS cement in relation to osteogenic gene markers in mesenchymal stem cells (MSCs). The CAS powder mixtures with 15 and 5 wt.% CSH were prepared by milling powder tetracalcium phosphate in an ethanolic solution of both orthophosphoric and sulfuric acids. The CAS cements had short setting times (around 5 min). The fast setting of the cement samples after the addition of the liquid component (water solution of NaH2PO4) was due to the partial formation of calcium sulfate dihydrate and hydroxyapatite before soaking in SBF with a small change in the original phase composition in cement powder samples after milling. Nanocrystalline hydroxyapatite biocement was produced by soaking of cement samples after setting in simulated body fluid (SBF). The fast release of calcium ions from CAS5 cement, as well as a small rise in the pH of SBF during soaking, were demonstrated. After soaking in SBF for 7 days, the final product of the cement transformation was nanocrystalline hydroxyapatite. The compressive strength of the cement samples (up to 30 MPa) after soaking in simulated body fluid (SBF) was comparable to that of bone. Real time polymerase chain reaction (RT-PCR) analysis revealed statistically significant higher gene expressions of alkaline phosphatase (ALP), osteonectin (ON) and osteopontin (OP) in cells cultured for 14 days in CAS5 extract compared to CSH-free cement. The addition of a small amount of nanoCSH (5 wt.%) to the tetracalcium phosphate (TTCP)/monetite cement mixture significantly promoted the over expression of osteogenic markers in MSCs. The prepared CAS powder mixture with its enhanced bioactivity can be used for bone defect treatment and has good potential for bone healing.

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A rapid, parasite-dependent cellular response to Dirofilaria immitis in the Mongolian jird (Meriones unguiculatus)

Parasites & Vectors ◽

10.1186/s13071-020-04455-x ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Christopher C. Evans ◽

Katherine M. Day ◽

Yi Chu ◽

Bridget Garner ◽

Kaori Sakamoto ◽

...

Keyword(s):

Cellular Response ◽

Dirofilaria Immitis ◽

Cell Attachment ◽

Early Response ◽

Meriones Unguiculatus ◽

Filarial Parasite ◽

Immune Mediated ◽

Secretory Products ◽

Species Specific

Abstract Background The Mongolian jird (Meriones unguiculatus) has long been recognized as a permissive host for the filarial parasite Brugia malayi; however, it is nonpermissive to another filarial parasite, canine heartworm (Dirofilaria immitis). By elucidating differences in the early response to infection, we sought to identify mechanisms involved in the species-specific clearance of these parasites. We hypothesized that the early clearance of D. immitis in intraperitoneal infection of the jird is immune mediated and parasite species dependent. Methods Jird peritoneal exudate cells (PECs) were isolated and their attachment to parasite larvae assessed in vitro under various conditions: D. immitis and B. malayi cultured separately, co-culture of both parasites, incubation before addition of cells, culture of heat-killed parasites, and culture with PECs isolated from jirds with mature B. malayi infection. The cells attaching to larvae were identified by immunohistochemistry. Results In vitro cell attachment to live D. immitis was high (mean = 99.6%) while much lower for B. malayi (mean = 5.56%). This species-specific attachment was also observed when both filarial species were co-cultured, with no significant change from controls (U(9, 14) = 58.5, p = 0.999). When we replicated these experiments with PECs derived from jirds subcutaneously infected with B. malayi, the results were similar (99.4% and 4.72% of D. immitis and B. malayi, respectively, exhibited cell attachment). Heat-killing the parasites significantly reduced cell attachment to D. immitis (mean = 71.9%; U(11, 14) = 7.5, p < 0.001) while increasing attachment to B. malayi (mean = 16.7%; U(9, 15) = 20, p = 0.002). Cell attachment to both species was reduced when larvae were allowed a 24-h pre-incubation period prior to the addition of cells. The attaching cells were identified as macrophages by immunohistochemistry. Conclusions These results suggest a strongly species-dependent response from which B. malayi could not confer protection by proxy in co-culture. The changes in cell attachment following heat-killing and pre-incubation suggest a role for excretory/secretory products in host immune evasion and/or antigenicity. The nature of this attachment is the subject of ongoing study and may provide insight into filarial host specificity.

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The Radiation-Induced Regenerative Response of Adult Tissue-Specific Stem Cells: Models and Signaling Pathways

Cancers ◽

10.3390/cancers13040855 ◽

2021 ◽

Vol 13 (4) ◽

pp. 855

Author(s):

Paola Serrano Martinez ◽

Lorena Giuranno ◽

Marc Vooijs ◽

Robert P. Coppes

Keyword(s):

Signaling Pathways ◽

Progenitor Cells ◽

Tissue Regeneration ◽

Normal Tissue ◽

Cellular Response ◽

Adult Tissue ◽

Tissue Specific ◽

Radiation Induced

Radiotherapy is involved in the treatment of many cancers, but damage induced to the surrounding normal tissue is often inevitable. Evidence suggests that the maintenance of homeostasis and regeneration of the normal tissue is driven by specific adult tissue stem/progenitor cells. These tasks involve the input from several signaling pathways. Irradiation also targets these stem/progenitor cells, triggering a cellular response aimed at achieving tissue regeneration. Here we discuss the currently used in vitro and in vivo models and the involved specific tissue stem/progenitor cell signaling pathways to study the response to irradiation. The combination of the use of complex in vitro models that offer high in vivo resemblance and lineage tracing models, which address organ complexity constitute potential tools for the study of the stem/progenitor cellular response post-irradiation. The Notch, Wnt, Hippo, Hedgehog, and autophagy signaling pathways have been found as crucial for driving stem/progenitor radiation-induced tissue regeneration. We review how these signaling pathways drive the response of solid tissue-specific stem/progenitor cells to radiotherapy and the used models to address this.

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Rapid Fabrication of Microfluidic Devices for Biological Mimicking: A Survey of Materials and Biocompatibility

Micromachines ◽

10.3390/mi12030346 ◽

2021 ◽

Vol 12 (3) ◽

pp. 346

Author(s):

Hui Ling Ma ◽

Ana Carolina Urbaczek ◽

Fayene Zeferino Ribeiro de Souza ◽

Paulo Augusto Gomes Garrido Carneiro Leão ◽

Janice Rodrigues Perussi ◽

...

Keyword(s):

Shear Stress ◽

Cell Viability ◽

Cellular Response ◽

Fluid Shear Stress ◽

Umbilical Vein ◽

Microfluidic Devices ◽

In Vitro Assays ◽

Stress Effect

Microfluidics is an essential technique used in the development of in vitro models for mimicking complex biological systems. The microchip with microfluidic flows offers the precise control of the microenvironment where the cells can grow and structure inside channels to resemble in vivo conditions allowing a proper cellular response investigation. Hence, this study aimed to develop low-cost, simple microchips to simulate the shear stress effect on the human umbilical vein endothelial cells (HUVEC). Differentially from other biological microfluidic devices described in the literature, we used readily available tools like heat-lamination, toner printer, laser cutter and biocompatible double-sided adhesive tapes to bind different layers of materials together, forming a designed composite with a microchannel. In addition, we screened alternative substrates, including polyester-toner, polyester-vinyl, glass, Permanox® and polystyrene to compose the microchips for optimizing cell adhesion, then enabling these microdevices when coupled to a syringe pump, the cells can withstand the fluid shear stress range from 1 to 4 dyne cm2. The cell viability was monitored by acridine orange/ethidium bromide (AO/EB) staining to detect live and dead cells. As a result, our fabrication processes were cost-effective and straightforward. The materials investigated in the assembling of the microchips exhibited good cell viability and biocompatibility, providing a dynamic microenvironment for cell proliferation. Therefore, we suggest that these microchips could be available everywhere, allowing in vitro assays for daily laboratory experiments and further developing the organ-on-a-chip concept.

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Effects of Platelet-Rich Plasma on Cellular Populations of the Central Nervous System: The Influence of Donor Age

International Journal of Molecular Sciences ◽

10.3390/ijms22041725 ◽

2021 ◽

Vol 22 (4) ◽

pp. 1725

Author(s):

Diego Delgado ◽

Ane Miren Bilbao ◽

Maider Beitia ◽

Ane Garate ◽

Pello Sánchez ◽

...

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Cellular Response ◽

Platelet Rich Plasma ◽

Biological Response ◽

In Vitro Models ◽

Molecular Composition ◽

Cellular Models ◽

The Central Nervous System

Platelet-rich plasma (PRP) is a biologic therapy that promotes healing responses across multiple medical fields, including the central nervous system (CNS). The efficacy of this therapy depends on several factors such as the donor’s health status and age. This work aims to prove the effect of PRP on cellular models of the CNS, considering the differences between PRP from young and elderly donors. Two different PRP pools were prepared from donors 65–85 and 20–25 years old. The cellular and molecular composition of both PRPs were analyzed. Subsequently, the cellular response was evaluated in CNS in vitro models, studying proliferation, neurogenesis, synaptogenesis, and inflammation. While no differences in the cellular composition of PRPs were found, the molecular composition of the Young PRP showed lower levels of inflammatory molecules such as CCL-11, as well as the presence of other factors not found in Aged PRP (GDF-11). Although both PRPs had effects in terms of reducing neural progenitor cell apoptosis, stabilizing neuronal synapses, and decreasing inflammation in the microglia, the effect of the Young PRP was more pronounced. In conclusion, the molecular composition of the PRP, conditioned by the age of the donors, affects the magnitude of the biological response.

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The Interactome of Cancer-Related Lysyl Oxidase and Lysyl Oxidase-Like Proteins

Cancers ◽

10.3390/cancers13010071 ◽

2020 ◽

Vol 13 (1) ◽

pp. 71

Author(s):

Sylvain D. Vallet ◽

Coline Berthollier ◽

Romain Salza ◽

Laurent Muller ◽

Sylvie Ricard-Blum

Keyword(s):

Protein Folding ◽

Cancer Progression ◽

Cellular Response ◽

Lysyl Oxidase ◽

Chaperone Activity ◽

Cross Linking ◽

Binding Assays ◽

Vessel Development ◽

New Interactions

The members of the lysyl oxidase (LOX) family are amine oxidases, which initiate the covalent cross-linking of the extracellular matrix (ECM), regulate ECM stiffness, and contribute to cancer progression. The aim of this study was to build the first draft of the interactome of the five members of the LOX family in order to determine its molecular functions, the biological and signaling pathways mediating these functions, the biological processes it is involved in, and if and how it is rewired in cancer. In vitro binding assays, based on surface plasmon resonance and bio-layer interferometry, combined with queries of interaction databases and interaction datasets, were used to retrieve interaction data. The interactome was then analyzed using computational tools. We identified 31 new interactions and 14 new partners of LOXL2, including the α5β1 integrin, and built an interactome comprising 320 proteins, 5 glycosaminoglycans, and 399 interactions. This network participates in ECM organization, degradation and cross-linking, cell-ECM interactions mediated by non-integrin and integrin receptors, protein folding and chaperone activity, organ and blood vessel development, cellular response to stress, and signal transduction. We showed that this network is rewired in colorectal carcinoma, leading to a switch from ECM organization to protein folding and chaperone activity.

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Hydrothermal synthesis of nanocrystalline hydroxyapatite–graphene nanosheet on Ti-6Al-7Nb: mechanical and in vitro corrosion performance

Journal of Materials Science Materials in Medicine ◽

10.1007/s10856-021-06514-w ◽

2021 ◽

Vol 32 (4) ◽

Author(s):

Oktay Yigit ◽

Burak Dikici ◽

Niyazi Ozdemir

Keyword(s):

Hydrothermal Reaction ◽

Hybrid Coatings ◽

Stoichiometric Ratio ◽

Corrosion Performance ◽

Graphene Nanosheet ◽

Graphene Layers ◽

Nanocrystalline Hydroxyapatite ◽

One Step ◽

Nano Size

AbstractThe hybrid coatings containing the graphene nano-sheet (GNS) and nano-hydroxyapatite (nHA) phases have been successfully synthesized on Ti6Al7Nb alloys by a one-step hydrothermal method. The hydrothermal reaction was carried out for 24 h at 200 °C. The GNS ratio has been altered as 1, 3, 5 and 7 wt.% in the coatings and, the results have compared with non- GNS containing coatings. The effect of the GNS ratio on the microstructure, hardness, and in vitro corrosion responses has been investigated in detail. The characterizations of the coatings were carried out by SEM, EDS, AFM, XRD and, FTIR. The corrosion behavior of the hybrid coatings was compared in Kokubo’s solution at 37 °C by using potentiodynamic polarization tests. The results showed that the hydroxyapatite phases were deposed on the graphene layers with nano-size nucleation with its Ca/P stoichiometric ratio. The best hydrophilicity (~52°) property has been obtained in nHA/3GNS coatings. In addition, the corrosion rates of coatings increased in the following order: nHA/3GNS < nHA/1GNS < nHA/7GNS < nHA/5GNS < only nHA.

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The Role of Biomimetic Hypoxia on Cancer Cell Behaviour in 3D Models: A Systematic Review

Cancers ◽

10.3390/cancers13061334 ◽

2021 ◽

Vol 13 (6) ◽

pp. 1334

Author(s):

Ye Liu ◽

Zahra Mohri ◽

Wissal Alsheikh ◽

Umber Cheema

Keyword(s):

Systematic Review ◽

Cellular Response ◽

3D Culture ◽

3D Models ◽

In Vitro Models ◽

Research Findings ◽

Tissue Models

The development of biomimetic, human tissue models is recognized as being an important step for transitioning in vitro research findings to the native in vivo response. Oftentimes, 2D models lack the necessary complexity to truly recapitulate cellular responses. The introduction of physiological features into 3D models informs us of how each component feature alters specific cellular response. We conducted a systematic review of research papers where the focus was the introduction of key biomimetic features into in vitro models of cancer, including 3D culture and hypoxia. We analysed outcomes from these and compiled our findings into distinct groupings to ascertain which biomimetic parameters correlated with specific responses. We found a number of biomimetic features which primed cancer cells to respond in a manner which matched in vivo response.

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Targeting of p38 Mitogen-Activated Protein Kinases to MEF2 Transcription Factors

Molecular and Cellular Biology ◽

10.1128/mcb.19.6.4028 ◽

1999 ◽

Vol 19 (6) ◽

pp. 4028-4038 ◽

Cited By ~ 172

Author(s):

Shen-Hsi Yang ◽

Alex Galanis ◽

Andrew D. Sharrocks

Keyword(s):

Transcription Factors ◽

Transcriptional Activation ◽

Cellular Response ◽

Map Kinases ◽

Biological Response ◽

Extracellular Signals ◽

Extracellular Signal ◽

Mitogen Activated Protein

ABSTRACT Mitogen-activated protein (MAP) kinase-mediated signalling to the nucleus is an important event in the conversion of extracellular signals into a cellular response. However, the existence of multiple MAP kinases which phosphorylate similar phosphoacceptor motifs poses a problem in maintaining substrate specificity and hence the correct biological response. Both the extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) subfamilies of MAP kinases use a second specificity determinant and require docking to their transcription factor substrates to achieve maximal substrate activation. In this study, we demonstrate that among the different MAP kinases, the MADS-box transcription factors MEF2A and MEF2C are preferentially phosphorylated and activated by the p38 subfamily members p38α and p38β2. The efficiency of phosphorylation in vitro and transcriptional activation in vivo of MEF2A and MEF2C by these p38 subtypes requires the presence of a kinase docking domain (D-domain). Furthermore, the D-domain from MEF2A is sufficient to confer p38 responsiveness on different transcription factors, and reciprocal effects are observed upon the introduction of alternative D-domains into MEF2A. These results therefore contribute to our understanding of signalling to MEF2 transcription factors and demonstrate that the requirement for substrate binding by MAP kinases is an important facet of three different subclasses of MAP kinases (ERK, JNK, and p38).

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