IntroductionMesenchymal stem cells (MSCs) are promising candidates for cell-based therapies. Human platelet lysate represents an efficient alternative to fetal bovine serum for clinical-scale expansion of MSCs. Different media used in culture processes should maintain the biological characteristics of MSCs during multiple passages. However, bone marrow-derived MSCs and adipose tissue-derived MSCs have not yet been directly compared with each other under human platelet lysate conditions. This study aims to conduct a direct head-to-head comparison of the biological characteristics of the two types of MSCs under human platelet lysate-supplemented culture conditions for their ability to be used in regenerative medicine applications.MethodsThe bone marrow- and adipose tissue-derived MSCs were cultured under human platelet lysate conditions and their biological characteristics evaluated for cell therapy (morphology, immunophenotype, colony-forming unit-fibroblast efficiency, proliferation capacity, potential for mesodermal differentiation, secreted proteins, and immunomodulatory effects).ResultsUnder human platelet lysate-supplemented culture conditions, bone marrow- and adipose tissue-derived MSCs exhibited similar fibroblast-like morphology and expression patterns of surface markers. Adipose tissue-derived MSCs had greater proliferative potential than bone marrow-derived MSCs, while no significantly difference in colony efficiency were observed between the two types of cells. However, bone marrow-derived MSCs possessed higher capacity toward osteogenic and chondrogenic differentiation compared with adipose tissue-derived MSCs, while similar adipogenic differentiation potential wase observed between the two types of cells. There were some differences between bone marrow- and adipose tissue-derived MSCs for several secreted proteins, such as cytokine (interferon-γ), growth factors (basic fibroblast growth factor, hepatocyte growth factor, and insulin-like growth factor-1), and chemokine (stem cell-derived factor-1). Adipose tissue-derived MSCs had more potent immunomodulatory effects than bone marrow-derived MSCs.ConclusionsAdipose tissue-derived MSCs have biological advantages in the proliferative capacity, secreted proteins (basic fibroblast growth factor, interferon-γ, and insulin-like growth factor-1), and immunomodulatory effects, but bone marrow-derived MSCs have advantages in osteogenic and chondrogenic differentiation potential and secreted proteins (stem cell-derived factor-1 and hepatocyte growth factor); these biological advantages should be considered systematically when choosing the MSC source for specific clinical application.

Background and ObjectivesThe exosomes released by mesenchymal stromal cells (MSCs) in classical FBS-containing media have been demonstrated as an alternative, cell-free therapy in various diseases including inflammatory bowel disease (IBD). It has been found that the function of exosomes is affected by culture condition. We previously developed a serum-free, xeno-free and chemically defined medium, and umbilical cord-derived MSCs in this medium retained the immunosuppressive capability.MethodsIn this study, we evaluated the immunosuppressive function of exosomes from MSCs (MSC-Exo) in defined medium and their therapeutic effect on treating colitis.Results and ConclusionsIn vitro studies indicated that MSC-Exo reduced the concentration of pro-inflammatory cytokines IFN-γ, TNF-α and IL-1β, and increased the secretion of anti-inflammatory cytokines TGF-β1 and IL-10, but no significant change of inhibitory effect on peripheral blood mononuclear cells proliferation was shown. In vivo experimental colitis showed that administration of MSC-Exo was able to significantly ameliorate the disease activity index score, weight loss, colon shortening, and the histological colitis score through up-regulation anti-inflammatory responses and down-regulation of inflammatory responses. Moreover, the use of MSC-Exo (200 μg) led to an improved therapeutic efficacy when compared with MSCs at a dose of 1×106 cells. Our findings indicate that the exosomes from MSCs in defined medium possess a certain degree of immunosuppressive effect in vitro and exhibit a therapeutic capability in a mouse model of DSS-induced colitis through suppressing inflammation mechanism.

BackgroundCord Blood (CB) has been considered a promising source of natural killer (NK) cells for cellular immunotherapy. However, it is difficult to expand the large numbers of highly pure NK cells from CB without cell sorting and feeder cells/multiple cytokines. In this study, we try to develop a simple, safe and economical method for ex vivo expansion and purification of NK cells from CB without cell sorting and feeder cells/multiple cytokines.ResultsThe large numbers (mean: 1.59 × 1010) of highly pure (≥90%) NK cells from CB could be obtained through interleukin-2, group A streptococcus and zoledronate stimulation of mononuclear cells using the 21-day culture approach. When compared to resting NK cells, expanded NK cells were a higher expression of activating receptors CD16, NKG2D, NKp30, NKp44, NKp46 and activating markers CD62L and CD69, while the inhibitory receptors, CD158a and CD158b remained largely unchanged. In addition, these cells showed a higher concentration of IFN-γ, TNF-α and GM-CSF secretion and cytotoxicity to K562 cells and acute myeloid leukemia targets than resting NK cells.ConclusionWe develop a simple, safe and economical method to obtain high yield, purity, and functionality NK cells from CB without cell sorting and feeder cells/multiple cytokines.

BACKGROUND BRAF V600E mutated colorectal cancer (CRC) is prone to peritoneal and distant lymph node metastasis and this correlates with a poor prognosis. The BRAF V600E mutation is closely related to the formation of an immunosuppressive microenvironment. However, the correlation between BRAF V600E mutation and changes in local immune microenvironment of CRC is not clear. AIM To explore the effect and mechanism of BRAF V600E mutant on the immune microenvironment of CRC. METHODS Thirty patients with CRC were included in this study: 20 in a control group and 10 in a treatment group. The density of microvessels and microlymphatic vessels, and M2 subtype macrophages in tumor tissues were detected by immunohistochemistry. Screening and functional analysis of exosomal long noncoding RNAs (lncRNAs) were performed by transcriptomics. The proliferation and migration of human umbilical vein endothelial cells (HUVECs) and human lymphatic endothelial cells (HLECs) were detected by CCK-8 assay and scratch test, respectively. The tube-forming ability of endothelial cells was detected by tube formation assay. The macrophage subtypes were obtained by flow cytometry. The expression of vascular endothelial growth factor (VEGF)-A, basic fibroblast growth factor (bFGF), transforming growth factor (TGF)-β1, VEGF-C, claudin-5, occludin, zonula occludens (ZO)-1, fibroblast activation protein, and α-smooth muscle actin was assessed by western blot analysis. The levels of cytokines interleukin (IL)-6, TGF-β1, and VEGF were assessed by enzyme-linked immunosorbent assay. RESULTS BRAF V600E mutation was positively correlated with the increase of preoperative serum carbohydrate antigen 19-9 ( P < 0.05), and with poor tumor tissue differentiation in CRC ( P < 0.01). Microvascular density and microlymphatic vessel density in BRAF V600E mutant CRC tissues were higher than those in BRAF wild-type CRC ( P < 0.05). The number of CD163 + M2 macrophages in BRAF V600E mutant CRC tumor tissue was markedly increased ( P < 0.05). Compared with exosomes from CRC cells with BRAF gene silencing, the expression of 13 lncRNAs and 192 mRNAs in the exosomes from BRAF V600E mutant CRC cells was upregulated, and the expression of 22 lncRNAs and 236 mRNAs was downregulated ( P < 0.05). The biological functions and signaling pathways predicted by differential lncRNA target genes and differential mRNAs were closely related to angiogenesis, tumor cell proliferation, differentiation, metabolism, and changes in the microenvironment. The proliferation, migration, and tube formation ability of HU...