WE43 magnesium-based alloy is modified and investigated for biodegradable gene-eluting stent applications as it is an ideal engineering material with good mechanical properties and offers better ...biocompatibility compared to aluminium/zinc (AZ) alloys. In this work, polycaprolactone (PCL) is coated on WE43 using two different solvents via ultrasonic atomization spray coating. For better adhesion of this PCL to the surface, anodization was performed on WE43 to increase bonding strength. Spray coating parameters such as solution concentration, number of spray passes, and atomizing power were optimized for the best coating performance. Characterizations on the coatings showed that both acetone and dichloromethane are suitable for spray coating PCL, but acetone is slightly better, and it is also safer and easier to use. The porous microstructure of oxides formed by anodization increased the bonding adhesion between PCL and WE43. PCL covering these oxides led to enhanced anticorrosion properties as this hydrophobic polymer decreased the water uptake and increased the corrosion resistance. This significantly improved corrosion resistance also maintains the mechanical properties of the WE43 as the mass loss decreased by a factor of four times after PCL coating, helping to keep the mechanical integrity of WE43. Having the oxide layer beneath the PCL coating prevented it from peeling off. Subsequent in vitro cell viability results showed that the PCL layer enhanced the viability of HAoEC cells.
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•Acetone is preferred over dichloromethane for spray coating of polycaprolactone.•Anodization increases the adhesion of polycaprolactone to WE43.•Anodization coupled with polycaprolactone decreases corrosion.•Polycaprolactone coating covers the porous oxide layer, leading to lower hydrogen formation.•Polycaprolactone enhances the biocompatibility of WE43.
The present investigation reports on the chemical composition of Cudrania tricuspidata fruit essential oil (CTEO) and examines its possible antimicrobial mode of action against food-borne pathogenic ...bacteria. The CTEO was obtained by hydrodistillation of C. tricuspidata fruits using a microwave-assisted extraction technique. Gas chromatography-mass spectrometry analysis of the CTEO resulted in the determination of 29 different compounds, representing 94.46% of the total oil. The CTEO (1000 μg/disc) showed potential antibacterial effect as diameters of inhibition zones (15.0 ± 0.1–21.0 ± 1.0 mm) against the tested food-borne pathogenic bacteria including Bacillus cereus ATCC 13061, Staphylococcus aureus ATCC 12600, Listeria monocytogenes ATCC 7644, Salmonella typhimurium ATCC 43174 and Escherichia coli O157:H7 ATCC 43889. The minimum inhibitory (MIC) and minimum bactericidal (MBC) concentration values of CTEO against the tested bacteria were found in the range of 250–1000 μg/mL, respectively. Also the CTEO had potential inhibitory effect on the cell viability of the tested pathogens at MIC concentration. The SEM analysis showed the inhibitory effect of CTEO as confirmed by considerable morphological alterations on the cell wall B. cereus ATCC 13061 and E. coli O157:H7 ATCC 43889. In addition, the CTEO revealed its mode of action on membrane integrity as confirmed by release of extracellular ATP, loss of 260-nm absorbing materials and leakage of potassium ions against food-borne pathogenic bacteria. These findings suggest that CTEO showed a broad-spectrum of antibacterial efficacy and compromise its mode of action on membrane integrity.
► Food-borne pathogens have become the major cause of illness world-wide. ► Antibacterial mode of action of CTEO was studied against food-borne pathogens. ► Characterization of essential oil was done by GC–MS analysis. ► The oil severely affected membrane permeability of the target pathogens. ► Morphological changes in the bacterial cells were confirmed by SEM observations.
Follicle-stimulating hormone (FSH) stimulates the proliferation, survival, and estradiol synthesis of granulosa cells by binding to their G protein-coupled receptors. Although FSH activates ...sphingosine kinase-1 (SPHK1) to induce sphingosine-1-phosphate (S1P) synthesis, which is required to mediate the proliferative and survival effect of this gonadotrophin, the mechanisms, and the role of S1P in estradiol synthesis have not been reported. This study aimed to evaluate the importance of FSH-induced S1P synthesis as a mediator of the effects of this gonadotrophin on granulosa cell viability and steroidogenesis and to determine if FSH-induced S1P synthesis depends on estradiol, cAMP, PKA, or PKC. To achieve these objectives, we tested the effects of FSH, a sphingosine kinase-1 inhibitor (SKI-178), estradiol and inhibitors of aromatase, cAMP, PKA, and PKC (Formestane, MDL-12330A, H-89 dihydrochloride hydrate and Calphostin C respectively), on granulosa cell viability, S1P and estradiol production, and the mRNA expression of CYP19A1 and STAR in four in vitro culture experiments. The addition of FSH (1 ng/mL) increased (P < 0.05) granulosa cells number and S1P concentration in the culture media. Conversely, the addition of SKI-178 (10 μM) reduced (P < 0.05) S1P concentration negating the effect of FSH on cell viability. Inhibition of PKC and PKA, but not cAMP, reduced (P < 0.05) S1P secretion of FSH treated granulosa cells. It is important to note that the reduction in S1P secretion was strong (49 %) with the use of the PKC inhibitor. The use of formestane (10 μg) did not modify (P > 0.05) S1P secretion in FSH-treated cells; however, the addition of 5 or 10 ng/mL of estradiol increased (P < 0.05) S1P secretion. Finally, FSH increased (P < 0.05) estradiol concentration in the culture media, but this effect was not blocked by the inhibition of S1P synthesis. Similarly, FSH, SKI-178 or their combination did not modify the mRNA expression of CYP19A1 and STAR. In conclusion, S1P synthesis is stimulated FSH in granulosa cells and mediated mainly by PKC. S1P in turn promotes the granulosa cell viability, however, this does not influence estradiol synthesis. Additionally, estradiol synthesis induced by FSH is not essential for S1P synthesis, however high estradiol concentration may stimulate S1P production by granulosa cells.
In recent years, stimuli-responsive degradation has emerged as a desirable design criterion for functional hydrogels to tune the release of encapsulated payload as well as ensure degradation of the ...gel upon completion of its function. Herein, redox-responsive hydrogels with a well-defined network structure were obtained using a highly efficient thiol-disulfide exchange reaction. In particular, gelation occurred upon combining thiol-terminated tetra-arm polyethylene glycol (PEG) polymers with linear telechelic PEG-based polymers containing pyridyl disulfide units at their chain ends. Rapid gelation proceeds with good conversions (>85%) to yield macroporous hydrogels possessing high water uptake. Furthermore, due to the presence of the disulfide linkages, the thus-obtained hydrogels can self-heal. The obtained hydrogels undergo complete degradation when exposed to environments rich in thiol-containing agents such as dithiothreitol (DTT) and L-glutathione (GSH). Also, the release profile of encapsulated protein, namely, bovine serum albumin, can be tuned by varying the molecular weight of the polymeric precursors. Additionally, it was demonstrated that complete dissolution of the hydrogel to rapidly release the encapsulated protein occurs upon treating these hydrogels with DTT. Cytotoxicity evaluation of the hydrogels and their degradation products indicated the benign nature of these hydrogels. Additionally, the cytocompatible nature of these materials was also evident from a live/dead cell viability assay. One can envision that the facile fabrication and their ability to degrade on-demand and release their payload will make these benign polymeric scaffolds attractive for various biomedical applications.
Ataxia‐telangiectasia (A‐T) is an autosomal recessive primary immunodeficiency (PID) disease that is caused by mutations in ataxia‐telangiectasia mutated (ATM) gene encoding a serine/threonine ...protein kinase. A‐T patients represent a broad range of clinical manifestations including progressive cerebellar ataxia, oculocutaneous telangiectasia, variable immunodeficiency, radiosensitivity, susceptibility to malignancies, and increased metabolic diseases. This congenital disorder has phenotypic heterogeneity, and the severity of symptoms varies in different patients based on severity of mutations and disease progression. The principal role of nuclear ATM is the coordination of cellular signaling pathways in response to DNA double‐strand breaks, oxidative stress, and cell cycle checkpoint. The pathogenesis of A‐T is not limited to the role of ATM in the DNA damage response (DDR) pathway, and it has other functions mainly in the hematopoietic cells and neurons. ATM adjusts the functions of organelles such as mitochondria and peroxisomes and also regulates angiogenesis and glucose metabolisms. However, ATM has other functions in the cells (especially cell viability) that need further investigations. In this review, we described functions of ATM in the nucleus and cytoplasm, and also its association with some disorder formation such as neurologic, immunologic, vascular, pulmonary, metabolic, and dermatologic complications.
MicroRNAs (miRs) are key modulators of cellular processes such as proliferation, apoptosis, as well as anti-cancer immune responses. Here, we evaluated the role of miR-424-5p in breast cancer (BC) ...and investigated its effects on T cell-related immune response.
BC tissues and cell lines were prepared and the expression of miR-424-5p and PD-L1, as well as the underlying molecular pathways, were assessed via qRT-PCR and western blotting. The MTT assay and flow cytometry were used to assess the effect of miR-424-5p on proliferation, apoptosis, autophagy, and cell cycle progression. The co-culture of T cells with MDA-MB-231 was performed for evaluating the role of miR-424-5p in rescuing T cell exhaustion.
The results indicated the down-regulation of miR-424-5p and up-regulation of PD-L1 expression in BC tissue specimens. MiR-424-5p transfection into PD-L1 overexpressing MDA-MB-231 cells decreased the expression of PD-L1. Also, miR-424-5p could reduce MDA-MB-231 cell viability through modulating apoptosis and autophagy pathways. Furthermore, miR-424-5p transfection leads to decreased colony formation and increased cell number at the G2/M phase. Western blot analysis illustrated that miR-424-5p could exert its anti-proliferative effect via modulating PTEN/PI3K/AKT/mTOR pathway. Moreover, it was demonstrated that suppression of PD-L1 by miR-424-5p could participate in regulating the expression of effector cytokines in T cells.
MiR-424-5p could be considered as a potential tumor-suppressor miR in regulating BC cellular growth, apoptosis, and T cell-related immune response through targeting PD-L1, and its downstream mediators. Therefore, we recognized miR-424-5p as a promising candidate for miR restoration therapy in BC patients.
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•There is a negative correlation between miR-424-5p and PD-L1 in breast cancer.•miR-424-5p could reduce breast cancer cell viability via modulating apoptosis and autophagy.•miR-424-5p could exert its anti-proliferative effect via regulating PTEN/PI3K/AKT/mTOR axis.•miR-424-5p could regulate the expression of cytokines in T cells via targeting PD-L1.
Exosomal miRNAs activates hepatic stellate cell (HSC) and promote fibrosis. miR-222 was found to be increased in hepatitis B virus (HBV)-infected hepatocytes, and ferroptosis was reported to ...ameliorate liver fibrosis (LF). Although miR-222 and ferroptosis have been implicated in LF, the association between miR-222 and ferroptosis and how they coordinate to regulate LF are still not explicit. This study investigates the roles of miR-222 and transferrin receptor (TFRC) in LF. Lipid reactive oxygen species (ROS) level was analyzed by flow cytometry. FerroOrange staining was used to measure intracellular iron level. Luciferase reporter assay was adopted to confirm the binding of miR-222 and TFRC. Real-time quantitative PCR and immunoblots were applied to analyze gene and protein expression. The results showed that supplementation of exosomes derived from HBV-infected LO2 cells remarkably enhanced LX-2 cell activation, evidenced by elevated hydroxyprolin (Hyp) secretion and α-SMA and COL1A2 expression. miR-222 was significantly increased in HBV-Exo. Overexpressing miR-222 upregulated cell viability, secretion of Hpy, and expression of α-SMA and COL1A2, which were all blocked by overexpression of TFRC. Further study showed that TFRC was a target of miR-222, and miR-222 promoted LX-2 cell activation through suppressing TFRC-induced ferroptosis in LX-2 cells. Exosomal miR-222 derived from HBV-infected hepatocytes promoted LF through inhibiting TFRC and TFRC-induced ferroptosis. This study emphasizes the significance of miR-222/TFRC axis in LF and suggests new insights in clinical decision making while treating LF.
Graphical abstract
Exosomes derived from HBV-infected LO2 cells promote LX-2 cell activation and liver fibrosis in mouse
Exosomal miR-222 derived from HBV-infected LO2 cells promotes LX-2 cell activation
TFRC is a target of miR-222 and inhibits LX-2 cell activation induced by miR-222
miR-222 promotes LX-2 cell activation through inhibiting TFRC-induced ferroptosis
The tyrosine kinase inhibitor lenvatinib is used to treat advanced hepatocellular carcinoma (HCC). Ferroptosis is a type of cell death characterized by the iron‐dependent accumulation of lethal lipid ...reactive oxygen species (ROS). Nuclear factor erythroid‐derived 2‐like 2 (Nrf2) protects HCC cells against ferroptosis. However, the mechanism of lenvatinib‐induced cytotoxicity and the relationships between lenvatinib resistance and Nrf2 are unclear. Thus, we investigated the relationship between lenvatinib and ferroptosis and clarified the involvement of Nrf2 in lenvatinib‐induced cytotoxicity. Cell viability, lipid ROS levels, and protein expression were measured using Hep3B and HuH7 cells treated with lenvatinib or erastin. We examined these variables after silencing fibroblast growth factor receptor‐4 (FGFR4) or Nrf2 and overexpressing‐Nrf2. We immunohistochemically evaluated FGFR4 expression in recurrent lesions after resection and clarified the relationship between FGFR4 expression and lenvatinib efficacy. Lenvatinib suppressed system Xc− (xCT) and glutathione peroxidase 4 (GPX4) expression. Inhibition of the cystine import activity of xCT and GPX4 resulted in the accumulation of lipid ROS. Silencing‐FGFR4 suppressed xCT and GPX4 expression and increased lipid ROS levels. Nrf2‐silenced HCC cells displayed sensitivity to lenvatinib and high lipid ROS levels. In contrast, Nrf2‐overexpressing HCC cells displayed resistance to lenvatinib and low lipid ROS levels. The efficacy of lenvatinib was significantly lower in recurrent HCC lesions with low‐FGFR4 expression than in those with high‐FGFR4 expression. Patients with FGFR4‐positive HCC displayed significantly longer progression‐free survival than those with FGFR4‐negative HCC. Lenvatinib induced ferroptosis by inhibiting FGFR4. Nrf2 is involved in the sensitivity of HCC to lenvatinib.
Regulation of ferroptosis by fibroblast growth factor receptor 4 (FGFR4) and nuclear factor erythroid‐derived 2‐like 2 (Nrf2) in hepatocellular carcinoma GPX4, glutathione peroxidase 4.
Severe acute respiratory syndrome coronavirus (SARS-CoV), an enveloped single-stranded positive-sense RNA virus, is a member of the genus
Betacoronavirus
, family Coronaviridae. The SARS-CoV envelope ...protein E is a small (∼8.4 kDa) channel-forming membrane protein whose sequence is highly conserved between SARS-CoV and SARS-CoV-2. As a viroporin, it is involved in various aspects of the virus life cycle including assembly, budding, envelope formation, virus release, and inflammasome activation. Here, SARS-CoV E protein was recombinantly expressed in HEK293 cells and channel activity and the effects of viroporin inhibitors studied using patch-clamp electrophysiology and a cell viability assay. We introduced a membrane-directing signal peptide to ensure transfer of recombinant E protein to the plasma membrane. E protein expression induced transmembrane currents that were blocked by various inhibitors. In an ion-reduced buffer system, currents were proton-dependent and blocked by viroporin inhibitors rimantadine and amantadine. I-V relationships of recombinant E protein were not pH-dependent in a classical buffer system with high extracellular Na
+
and high intracellular K
+
. E-protein mediated currents were inhibited by amantadine and rimantadine, as well as 5-(N,N-hexamethylene)amiloride (HMA). We tested a total of 10 flavonoids, finding inhibitory activity of varying potency. Epigallocatechin and quercetin were most effective, with IC
50
values of 1.5 ± 0.1 and 3.7 ± 0.2 nM, respectively, similar to the potency of rimantadine (IC
50
= 1.7 ± 0.6 nM). Patch-clamp results were independently verified using a modified cell viability assay for viroporin inhibitors. These results contribute to the development of novel antiviral drugs that suppress virus activity and proliferation.
Cellulose fiber–reinforced composite scaffolds have recently become an interesting target for biomedical and tissue engineering (TE) applications. Cassava bagasse, a fibrous solid residue obtained ...after the extraction of cassava starch and soluble sugars, has been explored as a potential source of cellulose and has been successfully used to enhance the mechanical properties of gelatin scaffolds for TE purposes. This study assessed the cytocompatibility of the cassava microfiber–gelatin composite scaffold using human embryonic kidney cells (HEK 293) and a breast cancer cell line (MDA MB 231) under ISO 10993-5 standards. The viability of cells within the composite scaffold was analyzed through MTT assay. The growth of HEK 293, as well as the cell morphology, was not affected by the presence of cellulose within the composite, whereas the growth of breast cancer cells appeared to be inhibited with noticeable changes in cell morphology. These findings suggest that the presence of the cassava fiber in gelatin is not cytotoxic to HEK 293 cells. Thus, the composite is suitable for TE purposes when using normal cells. On the contrary, the presence of the fiber in gelatin elicited a cytotoxic effect in MDA MB 231 cells. Thus, the composite may not be considered for three-dimensional (3D) tumor cell studies requiring cancer cell growth. However, further studies are required to explore the use of the fiber from cassava bagasse for its anticancer cell properties, as observed in this study.
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