Mesenchimal Stromal Cells Research Articles

Adrenergic Modulation of Hematopoiesis.

Hematopoiesis produce every day billions of blood cells and takes place in the bone marrow (BM) by the proliferation and differentiation of hematopoietic stem cells (HSC). HSC are found mainly adjacent to the BM vascular sinusoids where endothelial cells and mesenchimal stromal cells promote HSC maintenance by producing a variety of factors. Other cell types that regulate HSC niches include sympathetic nerves, non-myelinating Schwann cells and a variety of mature hematopoietic cells such as macrophages, neutrophils, and megakaryocytes. This review will focus on the role of adrenergic signals, i.e. of catecholamines, in the regulation of the HSC niche. The available evidence is rather controversial possibly due to the fact that adrenergic receptors are expressed by many cellular components of the niche and also by the often neglected observation that catecholamines may be produced and released also by the BM cells themselves. In addition one has to consider that, physiologically, the sympathetic nervous system (SNS) activity follows a circadian rhythmicity as driven by the suprachiasmatic nucleus (SCN) of the hypothalamus but may be also activated by cognitive and non-cognitive environmental stimuli. The adrenergic modulation of hematopoiesis holds a considerable potential for pharmacological therapeutic approaches in a variety of hematopoietic disorders and for HSC transplantation however the complexity of the system demands further studies. Graphical Abstract Sympathetic nerve termini may release NE while mature BM cells may release norepinephrine (NE) and / or epinephrine (E). Both may bind to β-adrenergic receptor (AR) expressed in nestin+MSC in the hematopoietic stem cell (HSC) niche and regulate the physiological trafficking of HSC by modulating the expression of CXCL12 and SCF. Both NE and E may also activate Lin - c-Kit+ Sca-1+ (LKS) cell via another AR. In addition, NE may also signal to α1-AR expressed in pre-B cells which by TGF-β secretion might regulate proliferation of their lymphoid progenitors in an autocrine manner and/or inhibit myeloid progenitors.

Stroke and Mesenchimal Stromal Cells: Mechanisms of Neuroprotection and Future Prospects

Stroke and Mesenchimal Stromal Cells: Mechanisms of Neuroprotection and Future Prospects

Toxic influence of detergents on human mesenchimal stromal cells during graft repopulation

Detergents are effective decellularization agents in order to obtain cell-free matrixes. However, the toxicity of residual detergent prevents the adhesion of cells to the matrix and the realization of their functions. In this study, the degree of influence of residual detergents on mesenchymal stromal cells after a series of washes was investigated. The human pulmonary valve were treated in three ways: 1% solution of sodium dodecyl sulfate, 1% solution of sodium deoxycholate and a combination of these solutions with the reduction of the concentration to 0.5%. After each of 8 steps washing buffer were collected. We investigated influence of residual detergents on cytotoxicity and effect on the metabolic activity of MSCs. Histologic analysis showed sufficient tissue decellularization in all groups. Matrixes were washed by successive incubations with 200 ml of phosphate buffer. Detergent concentrations in all samples ceased to be toxic only to the 4-cycle wash, and had no effect on the metabolism and viability of human MSCs. After 4-8 washing cycles decellularized pulmonary trunk fragments were successfully settled by mesenchymal stromal cells. Thus, a few successive washing fabrics pulmonary valve after decellularization reduce residual detergent to a safe level and lead to successful repopulation of acellular scaffolds with MSCs.

Effect of the bone marrow multipotent mesenchimal stromal cells to the neural tissue after ischemic injury in vitro

Stem cells application in neural system injuries is an actual and prospective scientific field of modern regenerative medicine. In recent years much attention has been paid for study of regenerative effects of multipotent mesenchymal stromal cells (MMSCs) from different sources on injured tissues.The aim of our study was to determine the level of tissue damage in hippocampus after in vitro model of ischemia and to investigate the effect of bone marrow MMSСs in non-contact co-culture with ischemic neural tissue. The ischemic injury of neural tissue in vitro was modeling in organotypic hippocampal slice culture (OHCs) by oxygen-glucose deprivation (OGD).Immunohistochemical analysis after 24 hours of BM-MMSCs co-cultivation with OHCs after ischemia showed a significant reduction of caspase-3-positive dead neural cells, as compared to those in ischemic damage without BM-MMSCs co-cultivation, and reducing of glial cells activation. After co-cultivation of OHCs after OGD with BM-MMSCs there remained cytoarchitectonics of the neural tissue.Analyzing of our data, the neuroprotective effects of BM-MMSCs in non-contact co-cultivation with ischemic hippocampal organotypic slice culture is shown.

In vivo detection of polyomaviruses JCV and SV40 in mesenchymal stem cells from human umbilical cords

Multipotent stromal cells are present in the Wharton's jelly matrix (WJSC) of the umbilical cord and can be used as an allogeneic source of cells to treat immunological disorders. Recently it was demonstrated that adult bone marrow (BM)-derived mesenchimal stromal cells (MSC) are susceptible to infection with viruses showing potential oncogenic properties, such as the polyomavirus JC (JCV). The aim of this study was to investigate the presence of human polyomaviruses (JCV, BK Virus-BKV, SV40, and Merkel cell polyomavirus-MCPyV) in WJSC, and explore the risk of infection. MSC samples from 35 umbilical cords were investigated by quantitative Real Time PCRs for the presence of DNA sequences of JCV, BKV, SV40, and MCPyV. JCV DNA was detected in 1/35 (2.8%) of MSC samples, while SV40 DNA was found in 3/35 (8.6%) of the examined samples. None of the samples showed sequences of BKV and MCPyV. The present study demonstrates the in vivo ability of polyomaviruses to infect WJSC. Since the therapeutic approach with the WJSC has high potentiality and a more intensive use can be easily hypothesized, the need to develop consensus guidelines to detect rare viral infections in MSC is pressing.

Impact of various modifications of biodegradable membranous scaffolds surface on multipotent mesenchimal stromal cells adhesion and viability

Designing a hybrid vascular graft using biocompatible and biodegradable polymers is one of the ways to fill the market with vascular grafts of a small diameter necessary for coronary artery bypass surgery. Good adhesive properties of cultivated cells and low cytotoxicity of biopolymers can improve biocompatibility of polymer-based vascular grafts. The impact of protein modification of membranous polyhydroxyalkanoate and polycaprolactone scaffolds surface on their adhesive properties and cytotoxicity to multipotent mesenchimal stromal cells was evaluated. We used the following compositions of membranous scaffolds: № 1 polyhydroxybutyrate valerate ММ 2 307 kDa with polycaprolactone ММ 80 000 kDa, № 2 had the same composition but was made using a magnetic stirrer, №3 polyhydroxybutyrate ММ 541 kDa with polycaprolactone ММ 80 000 kDa and № 4 polycaprolactone ММ 80 000 kDa only. Premodification of scaffolds surfaces with 75, 50 and 25% fetal calf serum was found to significantly reduce cytotoxicity of scaffold № 4 and improve the adhesive properties of scaffolds № 1, 2 and 3. Premodification with fibronectin (10 µg/ml) mostly improved the adhesive properties of scaffolds № 1—4.

Targeting ctla-4 directly on melanoma cells: A possible novel perspective in the immunotherapy of cutaneous melanoma

e22138 Background: CTLA-4 (CD152) is an omodimeric membrane glycoprotein which behaves as the major negative regulator of T cell-mediated immune response. CTLA-4 inhibitory function in T cells mainly occurs upon engagement with the B7 ligands expressed on antigen presenting cells, resulting in inhibition of cytokine production and T cell proliferation. CTLA-4 expression has also been documented in established human melanoma cell lines and primary melanoma tumours. The aim of this study was to investigate the expression and functional role of CTLA-4 in primary melanoma cultures derived from biopsies of metastatic melanoma patients. Methods: Seven primary cultures were derived from melanoma samples by mechanical tissue dissociation, enzymatic digestion and filtration of single cell suspensions. Flow cytometry (FACS) with an anti-melanoma (MCSP) mAb was used to assess the growth of melanoma cells. CTLA-4 expression analysis was performed by FACS and real-time PCR. Cytokine secretion and apoptotic cells were evaluated by Elisa and Annexin V/PI staining after treatment with an agonistic anti-CTLA-4 mAb (3D5). The angiogenic property of melanoma culture supernatants was evaluated on mesenchimal stromal cells (msc) isolated from human thoracic aortas. All the study was approved by our Institutional Ethics Committee and patients gave written informed consent. Results: Constitutive CTLA-4 expression was found on all melanoma cultures with variable intensity at both the protein and transcript levels. CTLA-4 expressed by these cells is functional as its ligation, with an anti-CTLA-4 agonistic mAb, is able to induce inhibition of cell proliferation, due to apoptosis induction, and of IL-8, TNF-alpha and VEGF cytokine secretion. Moreover, CTLA-4 ligation down-modulates the ability of melanoma culture supernatants to induce angiogenic differentiation of msc as detected by the acquisition of their endothelial phenotype. Conclusions: Given the physiologic inhibitory function of CTLA-4, our results suggest its possible role in the functional biology of melanoma and open up the possibility of an anti-melanoma immunotherapy based on targeting CTLA-4 directly on tumour cells as this might allow inhibition of tumour cell growth and angiogenesis. No significant financial relationships to disclose.

Influence of oxygen on three different types of telomerized cells derived from a single donor

Three primary cell cultures were derived from a single donor: skin fibroblasts (SF), dermal papilla cells (DP), and mesenchimal stromal cells from lipoaspirate (LA). After a high efficiency introduction of the gene of human telomerase catalytic component (hTERT) in lentiviral construct, we obtained three different strains of immortalized cells. All cells were cultured in a low oxygen (3%) environment. When telomerized cells were grown in atmospheric conditions (21% oxygen), growth retardation was observed after a period of 18–40 days. SF-hTERT and DP-hTERT overcame this retardation. In 30–45 days the rate of their growth became as high as it was in 3% oxygen. LA-hTERT cells were incapable to restore the previous growth rate and after several passages ceased proliferation. We found that telomerized cells were heterogeneous in their ability to form colonies at low density (3 cells per 1 cm2): they made 0–9 population doublings in 7 days. At the same time, mean growth rate of SF-hTERT did not change, while the growth of DP-hTERT and LA-hTERT cells was considerably accelerated in comparison with their growth in mass culture. Transfer of telomerized cells to 21% oxygen reduced their ability to form colonies to a different extent. The total number of cells grown in 21% oxygen was 3 times less than the number grown in 3% oxygen for SF-hTERT and DP-hTERT, and 6 times less for LA-hTERT. Original cells (with the exception of LA) were more sensitive to oxygen level than the corresponding telomerized cells. The total number of cells of all three strains (SF, DP, LA) grown in 21% oxygen was 6–7 times less. We discuss the reasons of incapability of LA-hTERT cells to adapt to atmospheric oxygen.