Endothelial progenitor cells (EPCs) clinical applications have been well reported. However, due to low number of EPCs that could be isolated, EPCs expansion study became one of the main focuses. Some optimized mediums to culture EPCs were currently available. However, the proliferation signaling pathway is not clearly disclosed yet. Peripheral blood was collected from eight healthy subjects, followed by mononuclear cells (MNCs) isolation. MNCs were then prepared and cultured for 2 days. After that, non-adherent cells were harvested and further cultured for 3 days. Resulted colony-forming unit (CFU)-Hill colonies were documented and enumerated under an inverted light microscope. To detect membrane markers, immunofluorescence was performed to detect CD34, VEGFR-2, and CD133. Cell documentation was conducted under a fluorescence microscope. To check cell proliferation, XTT Cell Proliferation Assay Kit was used according to kit insert. To detect possible activation of p44/42 MAPK, western blot was performed to detect p44/42 MAPK and phosphorylated p44/42 MAPK. All visualized bands were captured and quantified. Our results showed that EPCs markers (CD34, CD133 and VEGFR-2) were detected in 3 days culture. From XTT cell proliferation assay and CFU enumeration results, we found that EPCs proliferated significantly (p = 0.012) with addition of supplement. Phosphorylated-p42 MAPK expression of EPCs treated with supplement was significantly higher than the one of EPCs without treatment. Significant inhibition of p42 MAPK phosphorylation by U0126 was observed (p = 0.012). By pretreatment of U0126, number of viable cells and CFUs treated with supplement was significantly decreased (p = 0.012). Our results showed that MEK-dependent p42 MAPK pathway might play an important role in EPCs proliferation.

BACKGROUND: Secreted factors contained in conditioned media (CM) of human umbilical cord blood mesenchymal stem cells (hUCB-MSCs) known as secretome, was suspected to have important roles in regulating cells. This study was conducted to investigate the role of CM-hUCB-MSCs-derived secretome in apoptosis and growth of HeLa cells.METHODS: HeLa cells were treated with secretome in various concentrations (0, 0.2, 2 and 20%) for 24 and 48 hours. Trypan blue exclusion assay was performed to detect cell viability. Meanwhile sub-G1 apoptotic assay was performed to detect apoptotic cells. The transition of mitochondrial transmembrane potential (TMP), which occurs in the apoptotic process, was analyzed by mitochondrial membrane potential (ΔΨM) assay. Both sub-G1 and ΔΨM assays were performed using FACSCanto flow cytometer. Statistical analyses were conducted using IBM SPSS Statistics to detect significance level at p<0.05.RESULTS: Secretome significantly induced cell death starting at concentration of 0.2% within a 24-hour period (p<0.05). Secretome significantly induced cell death in concentration and time dependent manner (p<0.05). The cell death was then confirmed as apoptosis through sub-G1 analysis. Due to the underlying apoptotic mechanism, we found distinct decrease of TMP, indicating an increase in mitochondrial membrane permeability of HeLa cells. In addition, we found that HeLa cell growth was inhibited partially by secretome.CONCLUSION: Taken together, we conclude that CMhUCB-MSCs-derived secretome significantly induced apoptosis of HeLa cells in a concentration and time dependent manner through mitochondrial apoptotic pathway. The secretome might also play important role in inhibiting HeLa cell growth.KEYWORDS: umbilical cord blood, mesenchymal stem cell, secretome, apoptosis, growth, cancer

BACKGROUND: A population of circulating Endothelial Progenitor Cells (EPCs) has been reported to play important role in maintaining endothelial function and integrity. Since EPCs culture is crucial and an optimized medium is currently available. Therefore we conducted a study to investigate whether stable angina subjects peripheral blood-derived EPCs could be cultured in this medium. Here, we performed study to detect EPCs characteristics and extracellular signalregulated kinase (Erk)1/2 Mitogen-Activated Protein Kinase (MAPK) pathway as possible underlying pathway for EPCs proliferation.METHODS: Peripheral blood EPCs from 8 stable angina subjects were cultured in an optimized medium with/without addition of supplement for 1 or 3 days. Then, the membrane of cultured EPCs were detected with immunofluorescence method for CD34, Vascular Endothelial Growth Factor Receptor 2 (VEGFR-2) and CD133. Colony forming unit (CFU) enumeration was performed. XTT Cell proliferation assay was performed to assess EPCs growth after 1 and 3-days culture. The western blot analysis was performed to detect possible activation of Erk1/2 MAPK.RESULTS: Number of EPCs and CFU cultured for 3 days were significantly higher than the ones cultured for 1 day (p=0.012). EPCs membrane markers from stable angina subjects were detected as well as CFUs were formed. There were significant increase of EPCs number, CFUs number and phosphorylated-Erk2 amount when the groups with and without supplement were compared (p<0.05). Meanwhile U0126, a MAPK Erk1/2 (MEK1/2) inhibitor, significantly inhibited the supplement-induced EPCs number, CFUs number and phosphorylated-Erk2 amount (p<0.05).CONCLUSION: Our results showed that ERK2 MAPK signaling pathway might play an important role in supplement-induced peripheral blood EPCs proliferation in subjects with stable angina.KEYWORDS: endothelial progenitor cell, EPC, p42, Erk2, proliferation

BACKGROUND: Bromelain is a sulfhydryl proteolytic enzyme that can hydrolyze protein, protease or peptide. Bromelain can be found in pineapple stem, fruit and core. Bromelain is composed of 212 amino acid residues with cysteine-25 forming a polypeptide chain that can hydrolyze peptide bonds by H2O. In medicine, bromelain has been developed as antibiotic, cancer drug, anti-inflammatory agent and immunomodulator. In dentistry, bromelain has potential to reduce plaque formation on the teeth and to irrigate root canal.METHODS: Pineapple core was dried for 3 days to get simplicia. Then simplicia was extracted with water solvent for 24 hours. After that, the macerated-pineapple core crude extract-derived bromelain (PCB) was separated by Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) followed by Coomassie Brilliant Blue (CBB) staining to ensure the presence of bromelain. In cytotoxic test, NIH-3T3 fibroblast cultures were treated with extracts in various concentrations to for 24 or 48 hours. Number of fibroblasts was calculated using 3-(4,5-dimethylthiazol-2- yl)-2,5-Diphenyltetrazolium bromide (MTT) assay.RESULTS: Pineapple core extraction using maceration method produced relative high yield (concentration: 1.5424 g/mL) of bromelain, which was confirmed by CBB staining results with the molecular weight of 33 kDa. Based on cytotoxic test results of PCB on NIH-3T3 fibroblasts, 24-hours-incubation LD50 was 95.7 g/L, while 48-hours-incubation LD50 was 51.1 g/L.CONCLUSION: PCB has low cytotoxic effect in NIH-3T3 fibroblasts.KEYWORDS: bromelain, pineapple, extract, cytotoxic, MTT

Impairment of the endothelial progenitor cells (EPCs) ability to proliferate and migrate in the patients with coronary heart disease (CHD) is partly caused by oxidative stress. This research evaluates the effect of treatment with Ipomoea batatas L./purple sweet potato (PSP) extract and l-ascorbic acid on the proliferation and migration of impaired EPCs. EPCs were isolated from CHD patient’s peripheral blood. EPCs culture were cultivated and divided into control (untreated), PSP extract treatment (dose 1 and 25 μg/mL), and l-ascorbic acid treatment (dose 10 and 250 μg/mL) groups for 48 h. EPCs proliferation was analyzed with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation assay, and migration was evaluated with the cell migration assay kit. Statistical tests were evaluated using SPSS 25.0. This research showed that EPCs proliferation and migration was significantly higher in all PSP extract and l-ascorbic acid treatment compared to the control (p < 0.001). EPCs migration on treatment with a PSP extract dose of 25 μg/mL was significantly higher compared to the treatment with l-ascorbic acid dose of 250 μg/mL (303,000 ± 1000 compared to 215,000 ± 3000 cells, p< 0.001). In conclusion, both treatments with PSP extract and l-ascorbic acid can improve the proliferation and migration of impaired EPCs. At the dose of 25 μg/mL, PSP extract seems to be superior to the l-ascorbic acid dose of 250 μg/mL to improve EPCs migration.