Ultrastructural characteristics and immune profile of equine MSCs from fetal adnexa

Both in human and equine species, mesenchymal stem cells (MSCs) from amniotic membrane (AM) and Wharton\ue2\u80\u99s jelly (WJ), may be particularly useful for immediate use or in later stages of life, after cryopreservation in cell bank. The aim of this study was to compare equine AM- and WJ-MSCs in vitro features that may be relevant for their clinical employment. MSCs were more easily isolated from WJ, even if MSCs derived from AM exhibited more rapid proliferation (P< 0.05). Osteogenic and chondrogenic differentiation were more prominent in MSCs derived from WJ. This is also suggested by the lower adhesion of AM cells, demonstrated by the greater volume of spheroids after hanging drop culture (P< 0.05). Data obtained by PCR confirmed the immunosuppressive function of AM and WJ-MSCs and the presence of active genes specific for anti-inflammatory and angiogenic factors (IL-6, IL 8, IL-\uce\ub21). For the first time, by means of transmission electron microscopy (TEM), we ascertained that equine WJ-MSCs constitutively contain a very impressive number of large vesicular structures, scattered throughout the cytoplasm. Moreover, an abundant extracellular fibrillar matrix was located in the intercellular spaces among WJ-MSCs. Data recorded in this study reveal that MSCs from different fetal tissues have different characteristics that may drive their therapeutic use. These finding could be noteworthy for horses as well as for other mammalian species, including humans

Angiogenic and anti-inflammatory properties of micro-fragmented fat tissue and its derived mesenchymal stromal cells.

BACKGROUND: Adipose-derived mesenchymal stromal cells (Ad-MSCs) are a promising tool for advanced cell-based therapies. They are routinely obtained enzymatically from fat lipoaspirate (LP) as SVF, and may undergo prolonged ex vivo expansion, with significant senescence and decline in multipotency. Besides, these techniques have complex regulatory issues, thus incurring in the compelling requirements of GMP guidelines. Hence, availability of a minimally manipulated, autologous adipose tissue would have remarkable biomedical and clinical relevance. For this reason, a new device, named Lipogems® (LG), has been developed. This ready-to-use adipose tissue cell derivate has been shown to have in vivo efficacy upon transplantation for ischemic and inflammatory diseases. To broaden our knowledge, we here investigated the angiogenic and anti-inflammatory properties of LG and its derived MSC (LG-MSCs) population. METHODS: Human LG samples and their LG-MSCs were analyzed by immunohistochemistry for pericyte, endothelial and mesenchymal stromal cell marker expression. Angiogenesis was investigated testing the conditioned media (CM) of LG (LG-CM) and LG-MSCs (LG-MSCs-CM) on cultured endothelial cells (HUVECs), evaluating proliferation, cord formation, and the expression of the adhesion molecules (AM) VCAM-1 and ICAM-1. The macrophage cell line U937 was used to evaluate the anti-inflammatory properties, such as migration, adhesion on HUVECs, and release of RANTES and MCP-1. RESULTS: Our results indicate that LG contained a very high number of mesenchymal cells expressing NG2 and CD146 (both pericyte markers) together with an abundant microvascular endothelial cell (mEC) population. Substantially, both LG-CM and LG-MSC-CM increased cord formation, inhibited endothelial ICAM-1 and VCAM-1 expression following TNFα stimulation, and slightly improved HUVEC proliferation. The addition of LG-CM and LG-MSC-CM strongly inhibited U937 migration upon stimulation with the chemokine MCP-1, reduced their adhesion on HUVECs and significantly suppressed the release of RANTES and MCP-1. CONCLUSIONS: Our data indicate that LG micro-fragmented adipose tissue retains either per se, or in its embedded MSCs content, the capacity to induce vascular stabilization and to inhibit several macrophage functions involved in inflammation

Could hypoxia influence basic biological properties and ultrastructural features of adult canine mesenchymal stem /stromal cells?

The aim of the present study was to compare canine adipose tissue mesenchymal stem cells cultured under normoxic (20% O2) and not severe hypoxic (7% O2) conditions in terms of marker expression, proliferation rate, differentiation potential and cell morphology. Intra-abdominal fat tissue samples were recovered from 4 dogs and cells isolated from each sample were cultured under hypoxic and normoxic conditions. Proliferation rate and adhesion ability were determined, differentiation towards chondrogenic, osteogenic and adipogenic lineages was induced; the expression of CD44, CD34, DLA-DQA1, DLA-DRA1 was determined by PCR, while flow cytometry analysis for CD90, CD105, CD45 and CD14 was carried out. The morphological study was performed by transmission electron microscopy. Canine AT-MSCs, cultured under different oxygen tensions, maintained their basic biological features. However, under hypoxia, cells were not able to form spheroid aggregates revealing a reduction of their adhesivness. In both conditions, MSCs mainly displayed the same ultrastructural morphology and retained the ability to produce membrane vesicles. Noteworthy, MSCs cultivated under hypoxya revealed a huge shedding of large complex vesicles, containing smaller round-shaped vesicles. In our study, hypoxia partially influences the basic biological properties and the ultrastructural features of canine mesenchymal stem /stromal cells. Further studies are needed to clarify how hypoxia affects EVs production in term of amount and content in order to understand its contribution in tissue regenerative mechanisms and the possible employment in clinical applications. The findings of the present work could be noteworthy for canine as well as for other mammalian species

Equine Adipose-Derived Mesenchymal Stromal Cells Release Extracellular Vesicles Enclosing Different Subsets of Small RNAs

Background. Equine adipose-derived mesenchymal stromal cells (e-AdMSC) exhibit attractive proregenerative properties strongly related to the delivery of extracellular vesicles (EVs) that enclose different kinds of molecules including RNAs. In this study, we investigated small RNA content of EVs produced by e-AdMSC with the aim of speculating on their possible biological role. Methods. EVs were obtained by ultracentrifugation of the conditioned medium of e-AdMSC of 4 subjects. Transmission electron microscopy and scanning electron microscopy were performed to assess their size and nanostructure. RNA was isolated, enriched for small RNAs (<200 nt), and sequenced by Illumina technology. After bioinformatic analysis with state-of-the-art pipelines for short sequences, mapped reads were used to describe EV RNA cargo, reporting classes, and abundances. Enrichment analyses were performed to infer involved pathways and functional categories. Results. Electron microscopy showed the presence of vesicles ranging in size from 30 to 300 nm and expressing typical markers. RNA analysis revealed that ribosomal RNA was the most abundant fraction, followed by small nucleolar RNAs (snoRNAs, 13.67%). Miscellaneous RNA (misc_RNA) reached 4.57% of the total where Y RNA, RNaseP, and vault RNA represented the main categories. miRNAs were sequenced at a lower level (3.51%) as well as protein-coding genes (1.33%). Pathway analyses on the protein-coding fraction revealed a significant enrichment for the “ribosome” pathway followed by “oxidative phosphorylation.” Gene Ontology analysis showed enrichment for terms like “extracellular exosome,” “organelle envelope,” “RNA binding,” and “small molecule metabolic process.” The miRNA target pathway analysis revealed the presence of “signaling pathways regulating pluripotency of stem cells” coherent with the source of the samples. Conclusion. We herein demonstrated that e-AdMSC release EVs enclosing different subsets of small RNAs that potentially regulate a number of biological processes. These findings shed light on the role of EVs in the context of MSC biology