The current diabetes mellitus pandemic constitutes an important global health problem. Reductions in the mass and function of β-cells contribute to most of the pathophysiology underlying diabetes. Thus, physiological control of blood glucose levels can be adequately restored by replacing functioning β-cell mass. Sources of functional islets for transplantation are limited, resulting in great interest in the development of alternate sources, and recent progress regarding cell fate change via utilization of extracellular vesicles, also known as exosomes and microvesicles, is notable. Thus, this study investigated the therapeutic capacity of extracellular vesicle-mimetic nanovesicles (NVs) derived from a murine pancreatic β-cell line. To differentiate insulin-producing cells effectively, a three-dimensional in vivo microenvironment was constructed in which extracellular vesicle-mimetic NVs were applied to subcutaneous Matrigel platforms containing bone marrow (BM) cells in diabetic immunocompromised mice. Long-term control of glucose levels was achieved over 60 days, and differentiation of donor BM cells into insulin-producing cells in the subcutaneous Matrigel platforms, which were composed of islet-like cell clusters with extensive capillary networks, was confirmed along with the expression of key pancreatic β-cell markers. The resectioning of the subcutaneous Matrigel platforms caused a rebound in blood glucose levels and confirmed the source of functioning β-cells. Thus, efficient differentiation of therapeutic insulin-producing cells was attained in vivo through the use of extracellular vesicle-mimetic NVs, which maintained physiological glucose levels.

Introduction Dental mesenchymal stem cells (dMSCs) may differentiate into odontoblast-like cells and form mineralized nodules. In the current study, we investigated the effects of senescence on odontogenic differentiation of dMSCs. Methods dMSCs were serially subcultured until senescence. Telomere lengths and telomerase activities were determined by quantitative PCR. Expression of genes involved in cell proliferation and differentiation, e.g., Bmi-1, p16INK4A, osteocalcin (OC), dentin sialoprotein (DSP), bone sialoprotein (BSP), and dentin matrix protein-1 (DMP-1) were assayed by Western blotting and quantitative reverse transcription PCR. Exogenous Bmi-1 was expressed in dMSC using retroviral vectors. Odontogenic differentiation was assayed by alkaline phosphatase (ALP) activity. Results Subculture-induced replicative senescence of dMSCs led to reduced expression of Bmi-1, OC, DSPP, and BSP compared with rapidly proliferating cells, while p16INK4A level increased. The cells exhibited progressive loss of telomeric DNA during subculture, presumably due to lack of telomerase activity. Bmi-1 transduction did not affect proliferation of cells, but enhanced the expression of OC and DSPP in the late passage cultures. Bmi-1-transduced cells also demonstrated enhanced ALP activity and mineralized nodule formation. Conclusions These results indicate that dMSCs lose their odontogenic differentiation potential during senescence, in part, by reduced Bmi-1 expression.

Background: There is growing interest in the effect of postoperative analgesics on oncological outcomes after cancer surgery. We investigated the impact of tramadol after breast cancer surgery on recurrence and mortality and explored the mechanism by which tramadol affects cultured breast cancer cells in vitro. Methods: Electronic medical records of patients who underwent breast cancer surgery between November 2005 and December 2010 at Severance Hospital in Korea were reviewed. Cox regression analyses were used to identify factors related to postoperative recurrence and mortality. We performed the sensitivity test with propensity score matching to adjust for selection bias. In addition, we investigated the effects of tramadol on human breast adenocarcinoma ) cells via assessment of cell viability, clonogenic assay, and cell cycle analysis in vitro. Results: Of 2588 breast cancer patients, 36.4% had received tramadol. Those who received tramadol had a 0.71-fold decreased risk of recurrence and a 0.56-fold decrease in mortality. The MCF-7 cell viability assays showed that tramadol had an anti-proliferative effect by cell cycle arrest, suppressing colony formation, and regulation of oestrogen and progesterone receptors. Tramadol induced apoptosis of MCF-7 cells via extracellular signal-regulated kinases by decreasing of 5-hydroxytryptamine (HT) 2B receptor and transient receptor potential vanilloid-1 expression. Conclusions: After breast cancer surgery, patients who received tramadol had a decreased risk of postoperative recurrence and mortality. The anti-tumour effect of tramadol appears to involve inhibition of proliferation, induction of apoptosis, and effects on 5-HT 2B receptor and TRPV-1.

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Emerging evidence indicates the pronounced role of inflammasome activation linked to reactive oxygen species (ROS) in the sterile inflammatory response triggered by ischemia/reperfusion (I/R) injury. Ethyl pyruvate (EP) is an antioxidant and conveys myocardial protection against I/R injury, while the exact mechanisms remain elusive. We aimed to investigate the effect of EP on myocardial I/R injury through mechanisms related to ROS and inflammasome regulation. The rats were randomly assigned to four groups: (1) sham, (2) I/R-control (IRC), (3) EP-pretreatment + I/R, and (4) I/R + EP-posttreatment. I/R was induced by a 30 min ligation of the left anterior descending artery followed by 4 h of reperfusion. EP (50 mg/kg) was administered intraperitoneally at 1 h before ischemia (pretreatment) or upon reperfusion (posttreatment). Both pre- and post-EP treatment resulted in significant reductions in myocardial infarct size (by 34% and 31%, respectively) and neutrophil infiltration. I/R-induced myocardial expressions of NADPH oxidase-4, carnitine palmitoyltransferase 1A, and thioredoxin-interacting protein (TXNIP) were mitigated by EP. EP treatment was associated with diminished inflammasome activation (NOD-like receptor 3 (NLRP3), apoptosis-associated speck-like protein, and caspase-1) and interleukin-1β induced by I/R. I/R-induced phosphorylation of ERK and p38 were also mitigated with EP treatments. In H9c2 cells, hypoxia-induced TXNIP and NLRP3 expressions were inhibited by EP and to a lesser degree by U0126 (MEK inhibitor) and SB203580 (p38 inhibitor) as well. EP's downstream protective mechanisms in myocardial I/R injury would include mitigation of ROS-mediated NLRP3 inflammasome upregulation and its associated pathways, partly via inhibition of hypoxia-induced phosphorylation of ERK and p38.