Modulation of LXR signaling altered the dynamic activity of human colon adenocarcinoma cancer stem cells in vitro

Background: The expansion and metastasis of colorectal cancers are closely associated with the dynamic growth of cancer stem cells (CSCs). This study aimed to explore the possible effect of LXR (a regulator of glycolysis and lipid hemostasis) in the tumorgenicity of human colorectal CD133 cells. Methods: Human HT-29 CD133+ cells were enriched by MACS and incubated with LXR agonist (T0901317) and antagonist (SR9243) for 72 h. Cell survival was evaluated using MTT assay and flow cytometric analysis of Annexin-V. The proliferation rate was measured by monitoring Ki-67 positive cells using IF imaging. The modulation of LXR was studied by monitoring the activity of all factors related to ABC transporters using real-time PCR assay and western blotting. Protein levels of metabolic enzymes such as PFKFB3, GSK3β, FASN, and SCD were also investigated upon treatment of CSCs with LXR modulators. The migration of CSCs was monitored after being exposed to LXR agonist using scratch and Transwell insert assays. The efflux capacity was measured using hypo-osmotic conditions. The intracellular content of reactive oxygen species was studied by DCFH-DA staining. Results: Data showed incubation of CSCs with T0901317 and SR9243 reduced the viability of CD133 cells in a dose-dependent manner compared to the control group. The activation of LXR up-regulated the expression and protein levels of ABC transporters (ABCA1, ABCG5, and ABCG8) compared to the non-treated cells (p < 0.05). Despite these effects, LXR activation suppressed the proliferation, clonogenicity, and migration of CD133 cells, and increased hypo-osmotic fragility (p < 0.05). We also showed that SR9243 inhibited the proliferation and clonogenicity of CD133 cells through down-regulating metabolic enzymes PFKFB3, GSK3β, FASN, and SCD as compared with the control cells (p < 0.05). Intracellular ROS levels were increased after the inhibition of LXR by SR9243 (p < 0.05). Calling attention, both T0901317 and SR9243 compounds induced apoptotic changes in cancer stem cells (p < 0.05). Conclusions: The regulation of LXR activity can be considered as a selective targeting of survival, metabolism, and migration in CSCs to control the tumorigenesis and metastasis in patients with advanced colorectal cancers

Melatonin and prolonged physical activity attenuated the detrimental effects of diabetic condition on murine cardiac tissue

In this study, the combined effects of four-week swimming training and melatonin were examined on the oxidative response, inflammation, apoptosis, and angiogenesis capacity of cardiac tissue in the mouse model of diabetes. The mice were randomly allocated into five groups (n = 10 per group) as follows: Control; Diabetic group; Diabetic + Melatonin group; Diabetic + Exercise group; and Diabetic + Exercise + Melatonin group. 50 mg/kg streptozotocin was intraperitoneally administrated. In melatonin-treated groups, melatonin was injected intraperitoneally at 3 mg/kg body weight for four weeks and twice weekly. Swimming exercises were performed for four weeks. We measured cardiac superoxide dismutase, glutathione peroxidase enzymes, malondialdehyde, and total antioxidant capacity. The expression of tumor necrosis factor-α, Caspase�3, Sirtuin1, and Connexin-43 was measured using real-time PCR analysis. The vascular density was analyzed by immunohistochemistry using CD31 and α-smooth muscle actin antibodies. The combination of melatonin and exercise elevated cardiac superoxide dismutase, glutathione peroxidase coincided with the reduction of malondialdehyde and increase of total antioxidant capacity as compared to the diabetic mice (p &lt; 0.05). In Diabetic + Exercise + Melatonin mice, tumor necrosis factor-α, Caspase�3 was significantly down-regulated compared to the Diabetic group (p &lt; 0.05). Melatonin and exercise suppressed the expression of Connexin-43 and Sirtuin1 in diabetic mice in comparison with the control mice (p &lt; 0.05). H &amp; E staining showed necrosis and focal hyperemia reduction in the Diabetic + Exercise + Melatonin group compared to the Diabetic group. Data showed a decrease of CD31+ and α-smooth muscle actin+ vessels in the Diabetic group as compared to the normal samples (p &lt; 0.05). The number of CD31+ vessels, but not α-smooth muscle actin+ type, increased in the Diabetic + Exercise + Melatonin group compared to the Diabetic mice. These data demonstrated that exercise along with melatonin administration could diminish the detrimental effects of diabetes on cardiac tissue via using different mechanisms. © 2021 Elsevier Lt

Synthesis and in vitro evaluation of thermosensitive hydrogel scaffolds based on (PNIPAAm-PCL-PEG-PCL-PNIPAAm)/Gelatin and (PCL-PEG-PCL)/Gelatin for use in cartilage tissue engineering

Background: Biodegradable thermosensitive hydrogel scaffolds based on novel three-block PCL-PEG-PCL and penta block PNIPAAm-PCL-PEG-PCL-PNIPAAm copolymers blended with gelatin were prepared and examined on functional behavior of chondrocytes. Methods: In this work, we compared two different thermosensitive hydrogel scaffolds (PNIPAAm-PCL-PEG-PCL-PNIPAAm)/Gelatin and (PCL-PEG-PCL)/Gelatin prepared by TIPS (thermally induced phase separation) method. The feature of copolymers was characterized by FT-IR, 1 H NMR. The lower critical solution temperatures (LCSTs) of aqueous solutions of copolymers were measured by cloud point (turbidity) measurements. We also examined water absorption capacity and swelling ratio. Mechanical features of the prepared hydrogels were evaluated by stress-strain measurements. Thereafter, isolated chondrocytes were cultured on each scaffold for a period of 10&nbsp;days and cell arrangement and morphology studied pre-and post-plating. Cell survival assay was done by using MTT assay. The transcription level of genes Sox-9, Collagen-II, COMP, MMP-13 and oligomeric matrix protein was monitored by real-time PCR assay. The samples were also stained by Toluidine blue method to monitor the synthesis of proteoglycan. Results: Data demonstrated an increased survival rate in cells coated seeded on scaffolds, especially (PNIPAAm-PCL-PEG-PCL-PNIPAAm)/Gelatin as compared to control cells on the plastic surface. (PNIPAAm-PCL-PEG-PCL-PNIPAAm)/Gelatin had potential to increase the expression of genes Sox-6, Collagen-II, COMP and after 10&nbsp;days in vitro. Conclusion: Thermosensitive PCEC/Gel and (PNIPAAm-PCEC-PNIPAAm)/Gel hydrogel scaffolds that fabricated by TIPS method possesses useful hydrophilic properties for growth and cell embedding and secretion of extracellular matrix. It can serve as an ideal strategy to promote the formation of cartilage tissue

Quercetin alleviates high glucose-induced damage on human umbilical vein endothelial cells by promoting autophagy

Background: Quercetin, a flavonoid antioxidant, has been found to exert therapeutic effects in diabetic condition. Autophagy represents a homeostatic cellular mechanism for the turnover of unfolds proteins and damaged organelles through a lysosome-dependent degradation manner. We speculated that quercetin could protect endothelial cells against high glucose-induced damage by promoting autophagic responses. Methods: HUVECs viability was evaluated by MTT method. Griess and TBARS assays were used to monitor the levels of NO and MDA, respectively. Intracellular ROS generation was determined in DCFDA-stained cells analyzed by flow cytometry. To investigate the role of quercetin in endothelial cell migratory behavior, we used a scratch test. The level of autophagy proteins LC3, Beclin-1 and P62 were measured by western blotting technique. Results: Our results showed that quercetin had the potential to increase cell survival after exposure to high glucose (P &lt; 0.05). Total levels of oxidative stress markers were profoundly decreased and the activity of GSH was increased by quercetin (P &lt; 0.05). High glucose suppressed HUVECs migration to the scratched area (P &lt; 0.05). However, a significant stimulation in cell migration was observed after exposure to quercetin (P &lt; 0.05). Based on data, autophagy was blocked at the late stage by high glucose concentration while quercetin enhanced autophagic response by reducing the P62 level coincided with the induction of Beclin-1 and LC3-II to LC3-I ratio (P &lt; 0.05). All these beneficial effects were reversed by 3-methyladenine as an autophagy inhibitor. Conclusion: Together, our data suggest that quercetin could protect HUVECs from high glucose induced-damage possibly by activation of the autophagy response

3D-printed microneedles in biomedical applications

Conventional needle technologies can be advanced with emerging nano- and micro-fabrication methods to fabricate microneedles. Nano-/micro-fabricated microneedles seek to mitigate penetration pain and tissue damage, as well as providing accurately controlled robust channels for administrating bioagents and collecting body fluids. Here, design and 3D printing strategies of microneedles are discussed with emerging applications in biomedical devices and healthcare technologies. 3D printing offers customization, cost-efficiency, a rapid turnaround time between design iterations, and enhanced accessibility. Increasing the printing resolution, the accuracy of the features, and the accessibility of low-cost raw printing materials have empowered 3D printing to be utilized for the fabrication of microneedle platforms. The development of 3D-printed microneedles has enabled the evolution of pain-free controlled release drug delivery systems, devices for extracting fluids from the cutaneous tissue, biosignal acquisition, and point-of-care diagnostic devices in personalized medicine

Distinct Tie2 tyrosine phosphorylation sites dictate phenotypic switching in endothelial progenitor cells

Angiogenesis is a regulated process involving the proliferation, migration, and remodeling of different cell types particularly mature endothelial and their progenitor cells, nominated as endothelial progenitor cells (EPCs). Tie2/Tek is a tyrosine kinase receptor expressed by endothelial cells that induces signal transduction pathways involved in endothelial biology. To address the potential importance of the various tyrosine residues of Tie2 in EPC development, we generated a series of Tie2 tyrosine mutated (Y1106F, Y1100F, and Y1111F) EPCs and then assess the biological features of these cells. Clonogenic, tubulogenic, proliferative, migratory, and functional properties of these cells were analyzed. Next, GFP-positive EPCs containing Tie2 tyrosine mutations were systemically transplanted into sublethaly irradiated mice to analyze the potency of these cells for marrow reconstitution. We found that mutation in the Tie2 tyrosine 1106 residue directed EPCs toward a mature endothelial phenotype, which was associated with augmented tubulogenic and migratory properties, and increased phosphorylation of the active site (tyrosine 992) as well as increased vascular perfusion in the in vivo Matrigel plug assay. Moreover, transplantation of 1106 Tie2 mutant EPCs failed to reconstitute the bone marrow after myeloablation, whereas transplantation of EPCs with the 1100 or 1111 Tie2 tyrosine mutation resulted in bone marrow engraftment, leading to improved survival of recipient mice. Our findings demonstrate that the tyrosine 1106 residue in Tie2 plays a key role to maintain the stemness features of EPCs. © 2018 Wiley Periodicals, Inc

Modulatory effect of photobiomodulation on stem cell epigenetic memory: a highlight on differentiation capacity

Differentiation potential of stem cells into various lineages makes these cells as promising sources to treat multiple diseases. In this regard, the use of different strategies and protocols to increase differentiation capacity is highly demanded. Low-level laser therapy, a relatively noninvasive technique, has the capacity to accelerate the healing of numerous injuries and a portion of restorative capacity could be correlated with the stem cell activation and differentiation. Several mechanisms have been diagnosed to participate in orientation of stem cells to functional mature cells. Among them, the status of DNA methylation orchestrates the maintenance of tissue-specific gene expression during the differentiation procedure. DNA methylation is a momentous event in embryogenesis and functional maturation. This review article highlighted the potency of laser irradiation (low-level intensities) in the differentiation of stem cells by modulation of methylation. The analysis of these modalities could help us to understand the underlying mechanisms participating in the therapeutic effects of photobiomodulation. © 2019, Springer-Verlag London Ltd., part of Springer Nature

Metformin Effect on Endocan Biogenesis in Human Endothelial Cells Under Diabetic Condition

Background and aim: Endocan is a novel endothelium-derived proteoglycan and may play a role in endothelial cells activity under diabetic conditions. Here, we evaluated the effect of high glucose concentration (30 mmol glucose) on endocan level in presence or absence of metformin in human umbilical vein endothelial cells (HUVECs). Methods: Cells were incubated with 30 mmol glucose for 72 h. High glucose content, metformin (2.5 to 500 mmol) and compound C (10 mmol) effects were assessed on cell viability. HUVECs migration was studied by scratch test. The changes in endocan expression and protein level were evaluated by RT-PCR, ELISA and flow cytometry assays. Griess reaction was used to measure NO levels. Functional activity of endothelial cells was monitored related to lipoprotein lipase activity using Dil-Ac-LDL uptake. p-AMPK/AMPK ratio was assessed by western blotting. Results: Cells viability significantly was reduced under high glucose condition (p < 0.05). 30 mmol glucose inhibited HUVECs migration, whereas these features were improved by 50 mmol metformin (p < 0.05). Endocan transcription and protein levels were increased in diabetic HUVECs exposed to metformin (p < 0.05). Metformin increased NO production in HUVECs under high glucose condition (p < 0.001). Metformin increased LDL uptake capacity under high glucose condition (p < 0.05). The addition of compound C blunted these effects. Western blot analysis confirmed the increase of p-AMPK/AMPK ratio in metformin-treated cells. Conclusion: Data demonstrated that metformin could promote angiogenic potential of endothelial cells which its reduction is a main cause in the development of diabetic foot ulcer, probably by the regulation of endocan dynamics under high glucose conditio