Differential gene expression of Wharton's jelly-derived mesenchymal cells mediated by graphene oxide in basal and osteo-induced media

BACKGROUND

Graphene oxide (GO) is widespread in scaffold engineering owing to its extraordinary properties such as multiple oxygen functional groups, high hydrophilicity ability and biocompatibility. It is known to promote differentiation in mesenchymal stem cells, but concomitant comparison of its modulation on the expression profiles of Wharton's jelly (WJ)-MSC surface markers, lineage differentiation, and epigenetic regulatory genes in basal and induced condition are still lacking. Unraveling the fundamental mechanisms is essential for the effective utilization of WJ-MSCs incorporated with GO in therapy. This study aims to explore the unique gene expression profiles and epigenetic characteristics of WJ-MSCs influenced by GO.

METHODS AND RESULTS

The characterized GO-coated coverslip served as a substrate for culturing WJ-MSCs. In addition to investigating the impact of GO on cell proliferation and differentiation, we conducted a gene expression study using PCR array, while epigenetic control was assessed through bisulfite sequencing and Western blot analysis. Our findings indicate that the presence of GO maintained the proliferation and survival of WJ-MSCs. In the absence of induction, GO led to minor lipid and glycosaminoglycan deposition in WJ-MSCs. This was evidenced by the sustained expression of pluripotency and lineage-specific genes, demethylation at the OCT4 promoter, and a decrease in H3K9 methylation. In osteo-induced condition, the occurrence of osteogenesis appeared to be guided by BMP/TGF and ERK pathway activation, accompanied by the upregulation of osteogenic-related genes and downregulation of DNMT3b.

CONCLUSIONS

GO in osteo-induced condition create a favorable microenvironment that promotes the osteogenesis of WJ-MSCs by influencing genetic and epigenetic controls. This helps in advancing our knowledge on the use of GO as priming platform and WJ-MSCs an alternate source for bone repair and regeneration.

Human Mesenchymal Stromal Cells Derived from Perinatal Tissues: Sources, Characteristics and Isolation Methods

Mesenchymal stromal/stem cells (MSCs) derived from perinatal tissues have become indispensable sources for clinical applications due to their superior properties, ease of accessibility and minimal ethical concerns. MSCs isolated from different placenta (PL) and umbilical cord (UC) compartments exhibit great potential for stem cell-based therapies. However, their biological activities could vary due to tissue origins and differences in differentiation potentials. This review provides an overview of MSCs derived from various compartments of perinatal tissues, their characteristics and current isolation methods. Factors affecting the yield and purity of MSCs are also discussed as they are important to ensure consistent and unlimited supply for regenerative medicine and tissue engineering.

Production of Lectins from Marine Algae: Current Status, Challenges, and Opportunities for Non-Destructive Extraction

Marine algae are an excellent source of novel lectins. The isolation of lectins from marine algae expands the diversity in structure and carbohydrate specificities of lectins isolated from other sources. Marine algal lectins have been reported to have antiviral, antitumor, and antibacterial activity. Lectins are typically isolated from marine algae by grinding the algal tissue with liquid nitrogen and extracting with buffer and alcohol. While this method produces higher yields, it may not be sustainable for large-scale production, because a large amount of biomass is required to produce a minute amount of compound, and a significant amount of waste is generated during the extraction process. Therefore, non-destructive extraction using algal culture water could be used to ensure a continuous supply of lectins without exclusively disrupting the marine algae. This review discusses the traditional and recent advancements in algal lectin extraction methods over the last decade, as well as the steps required for large-scale production. The challenges and prospects of various extraction methods (destructive and non-destructive) are also discussed.

Stem Hexane Extract of Strobilanthes crispus Induces Apoptosis in Triple-Negative Breast Cancer Cell Line

Strobilanthes crispus is known to possess multiple health beneficial effects and reported to be traditionally used as medicine in several countries. This study was to investigate the anti-proliferative effects of S. crispus leaves and stem extracts on MDA-MB-231 by examining their effects on apoptosis pathway. The chemical compounds were extracted from leaves and stems using methanol followed by solvent partitioning. Two extracts were found to prevent MDA-MB-231 cell growth at the IC₅₀ of 45 μg/mL and 60 μg/mL, respectively, for leaf water (LW) and stem hexane (SH) extracts. Results showed that SH extract induces apoptosis by suppressing the protein expression of BCL-2 while the expression of pro-apoptotic proteins such as BAX and caspase nine were unchanged. Decrease of cyclin A2 in SH-treated cells suggested this effect was associated with the dysregulation of cell cycle. However, LW extract showed no effects on apoptosis and cell cycle arrest in the treated cells. Taken together, our results showed SH extract of S. crispus exhibiting their anti-proliferative activities by modulating apoptosis and cell cycle, but the underlying mechanisms exerted by LW extract requires further investigation.

Phyla nodiflora L. Extracts Induce Apoptosis and Cell Cycle Arrest in Human Breast Cancer Cell Line, MCF-7

Phyla nodiflora L. has been used as medicinal remedies for various ailments due to its antioxidant, anti-inflammatory, anti-bacterial, anti-tumor activity. Previously, we found that the plant extracts induced DNA fragmentation in MCF-7. This study was to investigate the modes of action of P. nodiflora in inhibiting breast cancer cells using leaf ethyl acetate (EA leaf), stem ethyl acetate (EA stem) and stem methanol (Met stem) extracts. The MTT assay showed that the anti-proliferative effects of P. nodiflora extracts were selective towards MCF-7 with a minimal effect on MCF10A. Morphological changes such as cell shrinkage and nuclear condensation were observed in treated cells. We found that induction of apoptosis by EA leaf and EA stem was mitochondrial-dependent while loss of mitochondrial membrane potential was not found in Met stem-treated cells. In addition, the expression levels of AIFM1, CASP9, CFLAR, and IGF1R were altered after treatment. Decreased BCL-2 expression was found in treated cells while BAX and caspases' expression was upregulated or maintained. All extracts caused perturbation of cell cycle at S phase by dysregulating the expression of cell cycle regulators such as CDKs and cyclins. Our findings indicate that P. nodiflora inhibits MCF-7 cells by inducing apoptosis and perturbing cell cycle.

The Advancement of Biomaterials in Regulating Stem Cell Fate

Stem cells are well-known to have prominent roles in tissue engineering applications. Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) can differentiate into every cell type in the body while adult stem cells such as mesenchymal stem cells (MSCs) can be isolated from various sources. Nevertheless, an utmost limitation in harnessing stem cells for tissue engineering is the supply of cells. The advances in biomaterial technology allows the establishment of ex vivo expansion systems to overcome this bottleneck. The progress of various scaffold fabrication could direct stem cell fate decisions including cell proliferation and differentiation into specific lineages in vitro. Stem cell biology and biomaterial technology promote synergistic effect on stem cell-based regenerative therapies. Therefore, understanding the interaction of stem cell and biomaterials would allow the designation of new biomaterials for future clinical therapeutic applications for tissue regeneration. This review focuses mainly on the advances of natural and synthetic biomaterials in regulating stem cell fate decisions. We have also briefly discussed how biological and biophysical properties of biomaterials including wettability, chemical functionality, biodegradability and stiffness play their roles.

Chemical composition and cytotoxic properties of Clinacanthus nutans root extracts

CONTEXT

Clinacanthus nutans Lindau (Acanthaceae) is a medicinal plant that has been reported to have anti-inflammatory, antiviral, antimicrobial and antivenom activities. In Malaysia, it has been widely claimed to be effective in various cancer treatments but scientific evidence is lacking.

OBJECTIVE

This study investigates the chemical constituents, anti-proliferative, and apoptotic properties of C. nutans root extracts.

MATERIALS AND METHODS

The roots were subjected to solvent extraction using methanol and ethyl acetate. The anti-proliferative effects of root extracts were tested at the concentrations of 10 to 50 μg/mL on MCF-7 and HeLa by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay for 72 h. Morphological changes were observed under light microscope. Pro-apoptotic effects of root extracts were examined using flow cytometric analysis and RT-PCR. The chemical compositions of root extracts were detected using GC-MS.

RESULTS

The proliferation of MCF-7 cells was inhibited with the IC₅₀ values of 35 and 30 μg/mL, respectively, for methanol and ethyl acetate root extracts. The average inhibition of HeLa cells was ∼25%. Induction of apoptosis in MCF-7 was supported by chromatin condensation, down-regulation of BCL2 and unaltered expression of BAX. However, only ethyl acetate extract caused the loss of mitochondrial membrane potential. GC-MS analysis revealed the roots extracts were rich with terpenoids and phytosterols.

DISCUSSION AND CONCLUSIONS

The results demonstrated that root extracts promote apoptosis by suppressing BCL2 via mitochondria-dependent or independent manner. The identified compounds might work solely or cooperatively in regulating apoptosis. However, further studies are required to address this.

ANTIOXIDANT AND ANTICANCER PROPERTIES OF SOLVENT PARTITIONED EXTRACTS OF Phyla nodiflora L

We previously found that the crude extracts of Phyla nodiflora L. are capable to inhibit cancer cells. In this study, we reassessed their anticancer properties after solvent partition extraction of the methanolic extracts. We also determined their total phenolic content (TPC) and total flavonoid content (TFC). Water, ethyl acetate and methanolic extracts showed higher TPC and TFC than chloroform or hexane extracts. Most of stem extracts exhibited higher antioxidant activity than the leaf extracts except for leaf methanolic extracts. Six of the extracts showed 50% growth inhibition at the concentration of 36-80 µg/ml. Both stem and leaf ethyl acetate extracts showed profound inhibition. They also caused DNA fragmentation in MCF-7 cells, indicating the occurrence of apoptosis. Our findings demonstrated that liquid-liquid partition has successfully separated methanolic extracts into several fractions with antioxidant and anticancer properties. This will facilitate the future investigation in identifying bioactive compounds for chemotherapeutic intervention.

Urgent endoscopy is associated with lower mortality in high-risk but not low-risk nonvariceal upper gastrointestinal bleeding

BACKGROUND AND STUDY AIMS

The role of urgent endoscopy in high-risk nonvariceal upper gastrointestinal bleeding (NVUGIB) is unclear. The aim of this study was to determine whether esophagogastroduodenoscopy (EGD) performed sooner than the currently recommended 24 h in high-risk patients presenting with NVUGIB is associated with lower all-cause in-hospital mortality.

METHODS

All adult patients undergoing EGD for the indications of coffee-grounds vomitus, hematemesis or melena at a university hospital over an 18-month period were enrolled. Patients with variceal and lower gastrointestinal bleeding were excluded. Data were prospectively collected.

RESULTS

A total of 934 patients were included. The area under the receiver operating characteristic curve (AUROC) for the Glasgow-Blatchford score (GBS) was 0.813 for predicting all-cause in-hospital mortality, with a cut-off score of ≥ 12 resulting in 90 % specificity. In low-risk patients with GBS < 12, presentation-to-endoscopy time in those who died and in those who survived was similar. In high-risk patients with GBS of ≥ 12, presentation-to-endoscopy time was significantly longer in those who died than in those who survived. Multivariate analysis of the high-risk cohort showed presentation-to-endoscopy time to be the only factor associated with all-cause in-hospital mortality. For high-risk patients, the AUROC for presentation-to-endoscopy time in predicting all-cause in-hospital mortality was 0.803, with a sensitivity of 100 % at the cut-off time of 13 h. All-cause in-hospital mortality in high-risk patients was significantly higher in those with presentation-to-endoscopy time of > 13 h compared with those undergoing endoscopy in < 13 h from presentation (44 % vs. 0 %; P < 0.001).

CONCLUSIONS

Endoscopy within 13 h of presentation was associated with lower mortality in high-risk but not low-risk NVUGIB.