1,721,021 research outputs found
Study of the effects of hyaluronan biosynthesis Inhibition by 4-methylumbelliferone on human Aortic smooth muscle cells.
No full textAfter atherogenic injury aortic smooth muscle cells (AoSMCs) which are normally located within the tunica media of blood vessels begin to synthesize high levels of extracellular matrix (ECM) components such as hyaluronan (HA), that is involved in the modulation of AoSMCs behaviour. During aging the onset of cardiovascular diseases increases dramatically and, in a cell aging in vitro model we found that in aged AoSMC HA synthesis is upregulated, enhancing their migration. Since HA strongly affects neointima formation we investigated the effect of HA synthesis inhibition by 4-methylumbelliferone (4MU), a natural derivative of coumarin, known to inhibit HA synthesis in some cell lines.
AoSMC treated with 4MU showed a dose dependent reduction of HA synthesis that could be related both to a reduced genetic expression of the key enzymes involved in its biosynthesis and to a reduction of the cellular pool of UDP-glucuronic acid, caused by the glucuronidation of this chemical by UGTs, that we found to be constitutively expressed and active in AoSMC. Gene expression analysis by Real-Time RT-PCR revealed that 4MU treatment dramatically reduces HAS2 expression: to confirm the key role of this enzyme in HA biosynthesis we abrogated its expression by means of siRNA, obtaining comparable results. As cellular migration is a key event in neointima invasion, we investigated 4MU effects on both cell migration and gelatinolytic activity. MMP2 is a MMP involved in matrix remodeling, playing a key role in AoSMC migration: 4MU does not affect MMP2 activity in AoSMC, moreover it determined a strong inhibition of cellular migration. As the addition of exogenous HA restored the migratory potential of this cells, we demonstrated, by means of a blocking antibody, the pivotal role of CD44 in this process. To investigate which cellular pathways were altered by 4MU treatment we performed a whole genome expression study using microarrays from Celera-Applied Biosystems and we found that 4MU treatment induced an alteration of p53 and cell cycle pathways. Moreover we found that 4MU treatment induced a reduction of cell proliferation and an increase of cell mortality by apoptosis, as shown by annexin-V staining, FACS analysis and PARP western blot. In order to verify the role of 4MU in the apoptotic process we performed rescue experiments by adding exogenous HMW-HA during treatment. Interestingly we found that 4MU induced apoptosis can be rescued by addition of exogenous HMW-HA to cell culture. Growing evidence of HA involvement in various human pathologies raises the question how to modulate its synthesis in tissues: these data introduce the possibility to reach this objective using a molecule already available in human therapy like 4MU
Vitamin D: A Nutraceutical Supplement at the Crossroad Between Respiratory Infections and COVID-19
Get PDFEven though in mid-2023 the World Health Organization declared the end of the public health emergency of international concern status for COVID-19, many areas of uncertainty about SARS-CoV-2 infection pathophysiology remain. Although in the last 4 years pharmaceutical industries widely invested in the development of effective antiviral treatments and vaccines, large disparities in their availability worldwide still exist, thus fostering the investigation of nutritional supplements as adjuvant therapeutic approaches for disease management, especially in resource-limited settings. During the COVID-19 pandemic, vitamin D has been widely used as an over-the-counter solution to improve disease evolution, thanks to its known immunomodulatory and anti-inflammatory actions. Ecological and observational studies support a relationship between hypovitaminosis D and COVID-19 negative outcomes and, according to this evidence, several research groups investigated the role of vitamin D supplementation in protecting from SARS-CoV-2 infection and/or improving disease evolution. This narrative review is intended to offer insights into the existing data on vitamin D’s biological effects in respiratory infections, especially in COVID-19. Furthermore, it will also offer a brief overview of the complex interplay between vitamin D and vaccine-elicited immune response, with special attention to anti-COVID-19 vaccines
Near-infrared laser increases MDPC-23 odontoblast-like cells proliferation by activating redox sensitive pathways
No full textNear infrared laser is known to induce biostimulatory effects, resulting in cell proliferation enhancement. Although
such positive effect is widely exploited in various clinical applications, molecular mechanisms involved
are still poorly understood. The aim of the study was to investigate the ability of laser stimulation to increase
cell proliferation through an early activation of three redox sensitive pathways, namely Nrf-2, NF-κB and ERK
in a rat odontoblast-like cell line (MDPC-23 cells).
MDPC-23 cells were irradiated with different energy settings (0–50 J, corresponding to 0–32.47 J/cm2) and cell
proliferation was evaluated by cell counting. Nrf-2, NF-κB and ERK signaling pathways activation was investigated
through Western blot analysis.
Our results show that a single 25 J laser stimulation is able to increase cell proliferation and that this effect could
be increased by repeating the stimulation twicewith a time lapse of 24 h. Western blot experiments demonstrated
that laser stimulation is able to induce an early activation response in intracellular signaling, with an overlapping
time pattern between the three considered pathways.
Results discussed in this paper reveal a complex mechanism underlying near-infrared induced increase in preodontoblasts
proliferation, involving three survival pathways that can act both separately or through reciprocal
crosstalk. In particular, data presented suggest an important role for ERK pathway that could act directly by stimulating
cell proliferation but can also induce both Nrf-2 and NF-κB activation, acting as a critical cellular checkpoint
in response to imbalanced redox state generated by a laser induced increase in ROS production
Epiregulin-loaded PLGA nanoparticles increase human keratinocytes proliferation: preliminary data
Get PDFOBJECTIVE:Epiregulin is a member of the epidermal growth factor (EGF) family produced by keratinocytes: the aim of this study was to investigate the ability of biocompatible nanoparticles loaded with such growth factor to increase human keratinocytes proliferation.
MATERIALS AND METHODS:Different PLGA (Poly-d,l-lactide-co-glycolide)-nanoparticles (NPs) formulations have been characterized in size and zeta potential by dynamic light scattering (DLS) analysis. The ability of the different PLGA-NPs formulations to adhere onto dental surfaces has been tested, and epiregulin-enriched PLGA-NPs has been produced. Epiregulin release from NPs has been tested by enzyme-linked immunosorbent (ELISA) assay and the proliferative effects of epiregulin-NPs on human keratinocytes have been evaluated.
RESULTS:DLS analysis revealed a different size distribution depending on the PLA/PGA (poly lactic acid/poly glycolic acid) ratio used. 50:50 PLGA-NPs exhibited the smaller size and the best dental adhesive ability. Moreover, such epiregulin-loaded NPs was able to increase cell proliferation.
CONCLUSIONS:Direct dental pocket drug delivery implies the NPs solution loading onto the dental surface at the cement-enamel junction level: 50:50 PLGA-NPs, with their small size and excellent adhesive ability, represent an interesting tool to deliver epiregulin directly where there is the need for epithelial proliferation. These results describe a possible strategy for periodontal pocket delivery of Epiregulin-loaded PLGA-NPs and might provide a new approach for the treatment of gingival recession, where gingival epithelium proliferation is needed
In vitro toxicity of photodynamic antimicrobial chemotherapy on human keratinocytes proliferation
No full textPre-odontoblast proliferation induced by near-infrared laser stimulation
Get PDFOBJECTIVE: Laser therapy is known to stimulate cell proliferation and differentiation, an effect called "biostimulation". Although many clinical applications of laser therapy take advantage from such positive effect, the underlying molecular mechanisms are not fully understood. The aim of this work was to investigate the effect of near-infrared laser stimulation on rat pre-odontoblast cells (MDPC-23 cells) and the molecular mechanism/s involved.
MATERIALS AND METHODS: MDPC-23 cells were stimulated with a near-infrared (980 nm) laser source with different energy settings (1-50 J, corresponding to 0.65-32.47 J/cm2) and cell proliferation was evaluated by manual count. ERK 1/2 pathway activation was evaluated by Western blot analysis.
RESULTS: 1-10 J stimulation (corresponding to 0.65-6.5 J/cm2) significantly increase MDPC-23 cell proliferation and such effect seems to be mediated by ERK 1/2 signalling pathway activation, showing a key role of ERK 1/2 pathway in mediating the proliferative response induced by laser stimulation.
CONCLUSIONS: Near infrared laser stimulation with low energies (1-10 J) is able to increase cell proliferation through ERK 1/2 signalling pathway activation. At the same time, higher energy stimulation (25-50 J) induces an initial toxic effect, probably activating pro-apoptotic signalling molecules, downstream ERK 1/2 kinase. Such results foster the application of this therapeutic approach in different clinical settings in which a regenerative tissue response is needed
Textile industry manufacturing by-products induce human melanoma cell proliferation via ERK1/2 activation
Get PDFOBJECTIVES:
Textiles used to make clothing can represent a source, often ignored, of chemicals potentially noxious to both skin and the whole organism. Among the most frequently produced potentially noxious chemical manufacturing by-products are formaldehyde (FA), nickel (Ni) and hexavalent chromium (Cr); they are of potential clinical interest as all are known to be carcinogenic to humans and to be potent skin sensitizers. The aim of this study was to investigate, in vitro, effects of these potentially dangerous compounds on two different melanoma cell lines. In particular, attention was focused on A375P, a poorly metastatic and low invasive cell line and SK-MEL-28, a highly metastatic cell line.
MATERIALS AND METHODS:
Effects of these compounds was evaluated on A375P and SK-MEL-28 cells. FA (1-5 × 10(-5) m), NiSO4 (10(-6) -10(-3) m), K2 Cr2 O7 (10(-7) -10(-6) m) effects on cell proliferation were evaluated by cell counting, while ERK pathway involvement was evaluated by Western blot analysis.
RESULTS:
Low concentrations of the chemicals, covering a range that corresponds to commonly accepted limits in textile production, induced a significant increase in cell proliferation concomitant with transient activation of phosphorylated ERK expression.
CONCLUSIONS:
Data obtained suggest that increasing attention must be focused on these by-products' potentially harmful effects in chemical manufacturing of clothes and accessories, that remain for long periods of time, in contact with human skin
Nicotine stimulation increases proliferation and matrix metalloproteinases-2 and -28 expression in human dental pulp cells
No full textDental pulp is the specialized tissue responsible for maintaining tooth viability. When tooth mineralized matrix is damaged, pulp is exposed to a plethora of environmental stimuli. In particular, in smokers, pulp become exposed to very high concentrations of nicotine. The aim of this study was to investigate the effect of direct nicotine stimulation on human dental pulp cell proliferation. Moreover, as it is known that nicotine could upregulate the expression of matrix metalloproteinases (MMPs), enzymes involved in pulpal inflammation, the effects of nicotine stimulation on MMP-2 and MMP-28 gene expression have also been investigated
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