To Be Or Not to Be: the “Smoker’s Paradox” – An in-Vitro Study

Background/Aims: Clinical studies have reported a better outcome of smokers after myocardial infarction compared to non-smokers. The data are controversial, as some clinical studies did not observe this effect. The cell biological processes involved, which might account for a ‘Smoker’s Paradox’, have not been investigated yet. Therefore, the aim was to elucidate the effect of cigarette smoke on the viability of cardiomyocytes in the context of hypoxia and reperfusion. Methods: HL-1 cells were incubated with different concentrations of cigarette smoke extract (CSE) and subjected to hypoxia/reperfusion to further evaluate influence of CSE on viability of HL-1 cells using flow cytometry analyses, Western Blot and immunofluorescence staining. Results: Incubation with CSE led to a concentration-dependent reduction in HL-1 viability. Adding hypoxia as a stressor enhanced cell death. Caspase-independent apoptosis was the observed type of cell death partly induced by P53 and apoptosis-inducing-factor. Yet a significant increase in LDH release in cardiomyocytes incubated with 4%, 8% and 16% CSE suggests necrosis with rapid DNA depletion. Interestingly, after hypoxia a decreased LDH release under lower CSE concentrations was observed. Moreover, a concentration-dependent increase in proliferation and a trend for increased ATP availability under hypoxic conditions was shown. Conclusions: The trend for less LDH release in hypoxia after low-level CSE incubation might represent a switch from necrosis to apoptosis, which in combination with the increase in metabolic activity and ATP availability might account for the ‘Smoker’s Paradox’. These findings could partly explain inconsistent results of previous clinical studies as the data showed strong evidence for the crucial relevance of the amount of cigarettes smoked. We are in need of future studies distinguishing between different types of smokers to finally verify or falsify the ‘Smoker’s Paradox’.

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18-kDa Translocator Protein Ligands Protect H9C2 Cardiomyocytes from Cigarette Smoke-induced Cell Death: In Vitro Study

In Vivo ◽

10.21873/invivo.11807 ◽

2020 ◽

Vol 34 (2) ◽

pp. 549-556

Author(s):

RAFAEL NAGLER ◽

NIDAL ZEINEH ◽

MAYA AZRAD ◽

NASRA YASSIN ◽

ABRAHAM WEIZMAN ◽

...

Keyword(s):

Cell Death ◽

Cigarette Smoke ◽

In Vitro Study ◽

Vitro Study ◽

Translocator Protein ◽

Protein Ligands ◽

H9c2 Cardiomyocytes

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The influence of cigarette smoke on colour stability and friction property of aesthetic orthodontic wires—In vitro study

International Orthodontics ◽

10.1016/j.ortho.2020.05.005 ◽

2020 ◽

Vol 18 (3) ◽

pp. 555-560

Author(s):

Flávio Mendonça Copello ◽

Lincoln Issamu Nojima ◽

Margareth Maria Gomes Souza ◽

Matheus Melo Pithon ◽

Antônio Carlos Oliveira Ruellas ◽

...

Keyword(s):

Cigarette Smoke ◽

In Vitro Study ◽

Vitro Study ◽

Colour Stability ◽

Friction Property ◽

Orthodontic Wires

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Human Neuronal Cell Lines as An In Vitro Toxicological Tool for the Evaluation of Novel Psychoactive Substances

International Journal of Molecular Sciences ◽

10.3390/ijms22136785 ◽

2021 ◽

Vol 22 (13) ◽

pp. 6785

Author(s):

Valeria Sogos ◽

Paola Caria ◽

Clara Porcedda ◽

Rafaela Mostallino ◽

Franca Piras ◽

...

Keyword(s):

Cell Death ◽

Neuronal Cell ◽

In Vitro Study ◽

Dependent Manner ◽

Novel Psychoactive Substances ◽

Psychoactive Substances ◽

Concentration Dependent Manner ◽

Mechanisms Of Toxicity ◽

Neuronal Cell Lines

Novel psychoactive substances (NPS) are synthetic substances belonging to diverse groups, designed to mimic the effects of scheduled drugs, resulting in altered toxicity and potency. Up to now, information available on the pharmacology and toxicology of these new substances is very limited, posing a considerable challenge for prevention and treatment. The present in vitro study investigated the possible mechanisms of toxicity of two emerging NPS (i) 4′-methyl-alpha-pyrrolidinoexanophenone (3,4-MDPHP), a synthetic cathinone, and (ii) 2-chloro-4,5-methylenedioxymethamphetamine (2-Cl-4,5-MDMA), a phenethylamine. In addition, to apply our model to the class of synthetic opioids, we evaluated the toxicity of fentanyl, as a reference compound for this group of frequently abused substances. To this aim, the in vitro toxic effects of these three compounds were evaluated in dopaminergic-differentiated SH-SY5Y cells. Following 24 h of exposure, all compounds induced a loss of viability, and oxidative stress in a concentration-dependent manner. 2-Cl-4,5-MDMA activates apoptotic processes, while 3,4-MDPHP elicits cell death by necrosis. Fentanyl triggers cell death through both mechanisms. Increased expression levels of pro-apoptotic Bax and caspase 3 activity were observed following 2-Cl-4,5-MDMA and fentanyl, but not 3,4-MDPHP exposure, confirming the different modes of cell death.

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Marginal Adaptation and Micropermeability of Class II Cavities Restored with Three Different Types of Resin Composites—A Comparative Ten-Month In Vitro Study

Polymers ◽

10.3390/polym13101660 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1660

Author(s):

Sevda Mihailova Yantcheva

Keyword(s):

Methylene Blue ◽

In Vitro Study ◽

Sem Analysis ◽

Marginal Adaptation ◽

Resin Composites ◽

Polymerization Shrinkage ◽

Gingival Margin ◽

Different Types ◽

Ageing Period

The development of composite materials is subject to the desire to overcome polymerization shrinkage and generated polymerization stress. An indicator characterizing the properties of restorative materials, with specific importance for preventing secondary caries, is the integrity and durability of marginal sealing. It is a reflection of the effects of polymerization shrinkage and generated stress. The present study aimed to evaluate and correlate marginal integrity and micropermeability in second-class cavities restored with three different types of composites, representing different strategies to reduce polymerization shrinkage and stress: nanocomposite, silorane, and bulk-fill composite after a ten-month ageing period. Thirty standardized class ΙΙ cavities were prepared on extracted human molars. Gingival margins were 1 mm apical to the cementoenamel junction. Cavities were randomly divided into three groups, based on the composites used: FiltekUltimate-nanocomposite; Filtek Silorane LS-silorane; SonicFill-bulk-fill composite. All specimens were subjected to thermal cycles after that, dipped in saline for 10-mounds. After ageing, samples were immersed in a 2% methylene blue. Thus prepared, they were covered directly with gold and analyzed on SEM for assessment of marginal seal. When the SEM analysis was completed, the teeth were included into epoxy blocks and cut longitudinally on three slices for each cavity. An assessment of microleakage on stereomicroscope followed. Results were statistically analyzed. For marginal seal evaluation: F.Ultimate and F.Silorane differ statistically with more excellent results than SonicFill for marginal adaptation to the gingival margin, located entirely in the dentin. For microleakage evaluation: F.Ultimate and F.Silorane differ statistically with less microleakage than SonicFill. Based on the results obtained: a strong correlation is found between excellent results for marginal adaptation to the marginal gingival ridge and micropermeability at the direction to the axial wall. We observe a more significant influence of time at the gingival margin of the cavities. There is a significant increase in the presence of marginal fissures (p = 0.001). A significant impact of time (p < 0.000) and of the material (p < 0.000) was found in the analysis of the microleakage.

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Antioxidant and Hypolipidemic Activity of Açai Fruit Makes It a Valuable Functional Food

Antioxidants ◽

10.3390/antiox10010040 ◽

2020 ◽

Vol 10 (1) ◽

pp. 40

Author(s):

Anna Virginia Adriana Pirozzi ◽

Paola Imbimbo ◽

Antonella D’Agostino ◽

Virginia Tirino ◽

Rosario Finamore ◽

...

Keyword(s):

Functional Food ◽

Subcutaneous Fat ◽

Cell Models ◽

Alcoholic Fatty Liver ◽

Hypoxic Conditions ◽

Tnf Α ◽

Different Types ◽

Vitro Model ◽

Alcoholic Fatty Liver Disease

Several plant extracts are acquiring increasing value because of their antioxidant activity and hypolipidemic properties. Among them, great interest has been recently paid to açai fruit as a functional food. The aim of this study was to test the ability of açai extract in reducing oxidative stress and modulating lipid metabolism in vitro using different cell models and different types of stress. In fact, lipid peroxidation as evaluated in a HepG2 model was reduced five-fold when using 0.25 µg/mL of extract, and it was further reduced (20-fold) with the concentration increase up to 2.5 µg/mL. With the non alcoholic fatty liver disease (NAFLD)in vitro model, all concentrations tested showed at least a two-fold reduced fat deposit. In addition, primary adipocytes challenged with TNF-α under hypoxic conditions to mimic the persistent subcutaneous fat, treated with açai extract showed an approximately 40% reduction of fat deposit. Overall, our results show that açai is able to counteract oxidative states in all the cell models analysed and to prevent the accumulation of lipid droplets. No toxic effects and high stability overtime were highlighted at the concentrations tested. Therefore, açai can be considered a suitable support in the prevention of different alterations of lipid and oxidative metabolism responsible for fat deposition and metabolic pathological conditions.

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