Hypoxia, Serum Starvation, and TNF-α Can Modify the Immunomodulation Potency of Human Adipose-Derived Stem Cells.

INTRODUCTION: Adipose-derived stem cells (ADSCs) are mesenchymal stem cells (MSCs) that are found in adipose tissues, which are easily obtained from liposuction procedures using an enzyme mixture. The adhering cells are then selectively cultivated. ADSCs have great potential in regenerative medicine because they are plentiful, easily accessible, and less invasive. They also have an impressive proliferation ability and can be differentiated into mesenchymal lineages and trans-differentiating into many other cell types. In particular, they have extraordinary abilities in immunomodulation. This study aimed to investigate the effects of culture conditions (hypoxia, starvation, and TNF-α treatment) on the immunomodulation of human ADSCs. METHODS: Human ADSCs were expanded in vitro in the standard condition before they were cultured in different stress conditions. ADSCs from passages fifth were confirmed as MSCs by some standard assays suggested by the International Society for Cell and Gene Therapy. These MSCs were used to culture in four different stress conditions: hypoxia, serum starvation, and TNF-α treatment in 48 h. After treatments, MSCs were used to evaluate their immunomodulation capacity using MSCs mixed lymphocyte reaction assay, and the concentrations of IDO, PGE2, IL-6, and IL-10 were secreted in the culture medium. RESULTS: In different stress conditions, ADSCs exhibited different responses related to their immunomodulation. In serum starvation, ADSCs exerted a strong secretion of IDO and PGE2, whereas they showed strong IL-6 secretion in the TNF-α-supplemented medium. When exposed to lymphocytes, ADSCs caused an increase in the ratio of regulatory T cells (Tregs), and co-culture lymphocytes with ADSCs induced in hypoxic malnutrition conditions increased the IL-10 level the most. In addition, when exposed to dendritic cells (DCs), ADSCs inhibited the mature marker expressions of the DCs. CONCLUSION: The current research showed that ADSCs change their immunomodulation properties to survive in in vitro culture environments. Treatment of ADSCs in the starvation medium for 48 h can increase the immunomodulation of ADSCs.

Cyclic and linear siloxanes in indoor air from several northern cities in Vietnam: Levels, spatial distribution and human exposure.

Earlier studies have reported the occurrence of cyclic and linear siloxanes in personal care and household products. Nevertheless, there is a lack of information on the occurrence of siloxanes in indoor air. In this study, four cyclic and six linear siloxanes were measured in 97 indoor air samples collected from various micro-environments in four cities in northern, Vietnam, during September 2016 to January 2017. The total concentrations of siloxanes (TSi) in particulate and gas phases ranged from 141 to 7220 µg g-1 (mean: 1880) and 23.8-1580 ng m-3 (mean: 321), respectively. The total concentrations of cyclic siloxanes (TCSi), linear siloxanes (TLSi), and TSi in indoor air were 1.91-1500 ng m-3, 21.8-817 ng m-3, and 41.8-1950 ng m-3, respectively. The highest mean concentration of siloxanes was found in indoor air from hair salons in Hanoi. The concentrations of siloxanes in air collected from homes in Hanoi were higher than those from other smaller cities such as Bacninh, Thaibinh, and Tuyenquang. The human exposures to siloxanes through inhalation were estimated for various age groups based on the measured concentrations. The mean inhalation exposure doses to total siloxanes for infants, toddlers, children, teenagers, and adults were 352, 219, 188, 132, and 95.9 ng kg-bw-1 d-1, respectively.

Occurrence of phthalate diesters in indoor air from several Northern cities in Vietnam, and its implication for human exposure.

Phthalates are used as plasticizers to impart flexibility of plastics. Because of their toxicity, human exposure to phthalates is a concern. Little is known on the occurrence of and inhalation exposure to phthalates in indoor air. In this study, ten phthalates were measured in 97 indoor air samples collected from Northern Vietnam during September 2016 to January 2017. The mean concentrations of total phthalates (i.e., sum of ten phthalates) in particulate and gas phases ranged from 95.2 to 13,100µgg-1 and from 57.0 to 14,900ngm-3, respectively. In bulk indoor air samples (i.e., gas plus particulate phase), the mean concentration of total phthalates ranged from 106 to 16,000ngm-3 (mean: 1040ngm-3). Diethyl phthalate (DEP) was found at the highest concentration in indoor air at a concentration range of below the method quantitation limit (MQL) to 12,400ngm-3 (mean: 376). Among various microenvironments, indoor air collected from hair salons contained the highest concentrations of phthalates (range: 596 to 16,000ngm-3). Among the four northern Vietnamese cities studied, the highest concentrations of phthalates were found in indoor air samples from Hanoi. The calculated mean inhalation exposure doses to phthalates for infants, toddlers, children, teenagers, and adults were 780, 485, 416, 292, and 213ngkg-bw-1d-1, respectively.

Targeting breast cancer stem cells by dendritic cell vaccination in humanized mice with breast tumor: preliminary results.

BACKGROUND: Breast cancer (BC) is one of the leading cancers in women. Recent progress has enabled BC to be cured with high efficiency. However, late detection or metastatic disease often renders the disease untreatable. Additionally, relapse is the main cause of death in BC patients. Breast cancer stem cells (BCSCs) are considered to cause the development of BC and are thought to be responsible for metastasis and relapse. This study aimed to target BCSCs using dendritic cells (DCs) to treat tumor-bearing humanized mice models. MATERIALS AND METHODS: NOD/SCID mice were used to produce the humanized mice by transplantation of human hematopoietic stem cells. Human BCSCs were injected into the mammary fat pad to produce BC humanized mice. Both hematopoietic stem cells and DCs were isolated from the human umbilical cord blood, and immature DCs were produced from cultured mononuclear cells. DCs were matured by BCSC-derived antigen incubation for 48 hours. Mature DCs were vaccinated to BC humanized mice with a dose of 10(6) cells/mice, and the survival percentage was monitored in both treated and untreated groups. RESULTS: The results showed that DC vaccination could target BCSCs and reduce the tumor size and prolong survival. CONCLUSION: These results suggested that targeting BCSCs with DCs is a promising therapy for BC.