Dehydroepiandrosterone protects endothelial cells against inflammatory events induced by urban particulate matter and titanium dioxide nanoparticles

Menopause, androgens, and cardiovascular ageing: a narrative review

Cardiovascular disease is the leading cause of death worldwide; however, women tend to be less affected than men during their reproductive years. The female cardiovascular risk increases significantly around the time of the menopausal transition. The loss of the protective action of ovarian oestrogens and the circulating androgens has been implicated in possibly inducing subclinical and overt changes in the cardiovascular system after the menopausal transition. In vitro studies performed in human or animal cell lines demonstrate an adverse effect of testosterone on endothelial cell function and nitric oxide bioavailability. Cohort studies evaluating associations between testosterone and/or dehydroepiandrosterone and subclinical vascular disease and clinical cardiovascular events show an increased risk for women with more pronounced androgenicity. However, a mediating effect of insulin resistance is possible. Data on cardiovascular implications following low-dose testosterone treatment in middle-aged women or high-dose testosterone supplementation for gender affirmatory purposes remain primarily inconsistent. It is prudent to consider the possible adverse association between testosterone and endothelial function during the decision-making process of the most appropriate treatment for a postmenopausal woman.

Titanium dioxide nanoparticles induce endothelial cell apoptosis via cell membrane oxidative damage and p38, PI3K/Akt, NF-κB signaling pathways modulation

BACKGROUND

Titanium dioxide nanoparticles (TiO₂ NPs) are widely used nanoparticles. Despite, several studies investigated the toxic effects of TiO₂ NPs on HUVECs, the results are contradictory and the possible underlying mechanisms remain unclear.

METHODS

In the present study, we conducted an in vitro study to re-evaluate the possible toxic effects of TiO₂ NPs on HUVECs including cell viability, lipids peroxidation, intracellular signaling pathways and nitric oxide syntheses enzymes.

RESULTS

Our results demonstrated that, TiO₂ NPs were internalized to HUVECs and induce intracellular reactive oxygen species production and cell membrane oxidative damage at the higher concentration. TiO₂ NPs induce IKKα/β and Akt phosphorylation and p38 dephosphorylation. After 24 h treatment, pro-inflammatory cytokines, adhesion molecules and chemokine upregulated significantly. TiO₂ NPs have no significant effects on eNOS enzymatic activation and iNOS gene expression. At cellular level, apoptosis is the main process that occur in response to TiO2 NPs treatment. HUVECs pretreatment with N-acetyl-l-cysteine (NAC) ameliorate the toxic effects of TiO₂ NPs that indicate the oxidative stress is essential in TiO₂ NPs -induced toxicity. Total antioxidant capacity show a trend to increase in response to TiO₂ NPs exposure.

CONCLUSIONS

Taken together, this study confirmed the effects of TiO₂ NPs on endothelial cells and proposed multiple underlying mechanisms including cell membrane oxidative damage and intracellular processes.

Urban particulate matter induces the expression of receptors for early and late adhesion molecules on human monocytes

Exposure to urban particulate matter (PM) is correlated with increases in the emergence of health services due to adverse events and deaths and is mainly related to cardiorespiratory complications. The translocation of particles from the lung into circulation has been proposed as a factor that may trigger systemic effects. Monocytes may be exposed to PM, and if the monocytes are activated, then they are likely to adhere to endothelial cells in a distant organ due to the expression of receptors for adhesion molecules. In the present study, we evaluated the expression of receptors for adhesion molecules (sLe^x, PSGL-1, LFA-1, VLA-4 and α_Vβ₃) in monocytes (U937 cells) exposed for 3 or 18 h to PM₁₀ (0.001, 0.003, 0.010, 0.030, 0.300, 3 or 30 µg/mL). Exposed cells were co-cultured with human endothelial cells that were naive or previously exposed to the same particles. When U937 cells were exposed to PM₁₀, similar levels of expression for early and late receptors for adhesion molecules were observed from 30 ng/mL as those induced by TNF-α. Cells exposed to particles at concentrations above 30 ng/mL were more adhesive to naive or exposed human endothelial cells. Taken together, our results suggest that it is plausible that activated monocytes may play a role in systemic effects induced by PM₁₀ due to the size distribution of the particles and the concentrations required to trigger the expression of receptors for adhesion molecules in monocytes.

Dehydroepiandrosterone and Addiction

Drug addiction has a great negative influence on society, both social and economic burden. It was widely thought that addicts could choose to stop using drugs if only they had some self-control and principles. Nowadays, science has changed this view, defining drug addiction as a complex brain disease that affects behavior in many ways, both biological and psychological. Currently there is no ground-breaking reliable treatment for drug addiction. For more than a decade we are researching an alternative approach for intervention with drug craving and relapse to its usage, using DHEA, a well-being and antiaging food supplement. In this chapter we navigate through the significant therapeutic effect of DHEA on the brain circuits that control addiction and on behavioral performance both in animal models and addicts. We suggest that an integrative program of add-on DHEA treatment may further enable to dynamically evaluate the progress of rehabilitation of an individual patient, in a comprehensive assessment. Such a program may boost and support the detoxification and rehabilitation process, and help patients regain a normal life in a shorter amount of time.

Preparation, characterizations and anti-pollutant activity of 7,3',4'-trihydroxyisoflavone nanoparticles in particulate matter-induced HaCaT keratinocytes

Background

7,3',4'-Trihydroxyisoflavone (734THI), a secondary metabolite derived from daidzein in soybean, possesses several biological activities, including antioxidant, skin whitening and anti-atopic dermatitis properties, but the poor aqueous solubility of 734THI has limited its application in medicine and cosmetic industry.

Methods

The aim of the present study was to improve the physicochemical properties of 734THI using planetary ball mill preparation under a solvent-free process to improve its solubility and anti-pollutant activity.

Results

734THI nanoparticle powder (734THIN) was successfully prepared by the planetary ball mill technique using polyvinylpyrrolidone K30 as the excipient. 734THIN effectively increased the aqueous solubility and cellular uptake of 734THI by improving its physicochemical properties, including particle size reduction, crystalline-amorphous transformation and intermolecular hydrogen bonding with polyvinylpyrrolidone K30. In addition, 734THIN inhibited the overexpression of COX-2 and MMP-9 by downregulating MAPK pathway signaling in particulate matter-exposed HaCaT keratinocytes, while raw 734THI in PBS with low aqueous solubility did not show any anti-inflammatory or antiaging activity.

Conclusion

734THIN may be used as an additive in anti-pollutant skin care products for preventing particulate matter-induced inflammation and aging in skin.

The disease-modifying effect of dehydroepiandrosterone in different stages of experimentally induced osteoarthritis: a histomorphometric study

Background

Osteoarthritis (OA) is likely to become an increasing burden in the coming decades. Various agents have been developed to slow the progression of OA, and are collectively known as ‘disease-modifying drugs’, however, there is still little reliable evidence that such agents will be successful. Dehydroepiandrosterone (DHEA), a sex hormone precursor, has been recently proven as protective agent against OA, but the exact mechanism is still unkown. In the current study, the effects of weekly intra-articular injections of DHEA in preventing the progression of existing cartilage degeneration in an OA rabbit model were evaluated. The aim of the current study is to demonstrate the feature of its disease-modifying efficacy during OA progression.

Methods

Thirty male New Zealand white rabbits were used in this study. An anterior cruciate ligament transection (ACLT) model was used to create a progressive OA model in twenty rabbits. The animals were treated with DHEA or a placebo and were necropsied at 9 and 16 weeks. Ten rabbits receiving sham operations served as controls. The articular cartilage of the medial femoral condyle (MFC), lateral femoral condyle (LFC), medial tibial plateau (MTP) and lateral tibial plateau (LTP) was evaluated macroscopically and histologically.

Results

In the joints of the sham-operated rabbits, few histological changes were detected on the articular surfaces of the femoral condyles and tibial plateaus. ACLT obviously induced erosive changes on the cartilage surfaces. Compared to the placebo group, the macroscopic and Mankin score analyses demonstrated that the DHEA treatment markedly reduced the cartilage lesions and delayed cartilage degeneration in the four regions of the knee at 9 weeks after operation (macroscopic score: MFC P = 0.013; LFC P = 0.048; MTP P = 0.045; LTP P = 0.02, Mankin score: MFC P = 0.012; LFC P = 0.034; MTP P = 0.016; LTP P = 0.002). At 16 weeks, DHEA demonstrated chondroprotective effects on the lateral compartment of the knee compared to the placebo group, whereas the cartilage degeneration at the medial compartment of the knee did not differ among the groups (macroscopic score: LFC P = 0.046; LTP = 0.034, Mankin score: LFC P = 0.005; LTP P = 0.002).

Conclusion

The disease-modifying efficacy of DHEA aganist OA is time-specific and site-dependent. DHEA could be used as a disease-modifying strategy to limit the progression of OA, especially in the middle stage.

HTCC-modified nanoclay for tissue engineering applications: a synergistic cell growth and antibacterial efficiency

This paper deals with the synthesis of a biocompatible chitosan ammonium salt N-(2-hydroxy) propyl-3-trimethylammonium chitosan chloride (HTCC) and using it in montmorillonite ion-exchange process. HTCC-modified montmorillonite (Mt) with different chemical ratios was successfully synthesized, and their characteristics have been verified by XRD and FTIR analyses. Produced samples have been evaluated in terms of antibacterial efficiency and biocompatibility (cell culture test). Antibacterial efficiency of synthesized HTCC/Mt samples has been confirmed against both gram negative bacteria (Escherichia coli) and gram positive bacteria (Staphylococcus aureus). The results disclosed that the antibacterial efficiency of HTCC-modified montmorillonite was unexpectedly even more than HTCC. This excellent synergistic effect has been referred to entrapping bacteria between the intercalated structures of HTCC-modified montmorillonite. Then HTCC on clay layers can seriously attack and damage the entrapped bacteria. An extraordinary biocompatibility, cell attachment, and cell growth even more than tissue culture polystyrene (TCPS) have been recorded in the case of this novel kind of modified clay. Due to existing concerns about serious and chronic infections after implant placement, this natural-based bioactive and antibacterial modified clay can be used in electrospun nanofibers and other polymeric implants with promising mechanical properties for tissue engineering applications.