Ultrasound-guided Intracardiac Injection of Human Mesenchymal Stem Cells to Increase Homing to the Intestine for Use in Murine Models of Experimental Inflammatory Bowel Diseases

Crohn&#39;s disease (CD) is a common chronic inflammatory disease of the small and large intestines. Murine and human mesenchymal stem cells (MSCs) have ...

Case Western Reserve University

Fibrin has been used extensively in cell encapsulation because it has important biological properties. Keratinocyte encapsulation in fibrin is a widely used technique in skin tissue engineering. The production of growth factors (EGF, TGF-beta1 and PDGF-BB) was evaluated when keratinocytes are encapsulated in fibrin. Secretions of TGF-beta1 and PDGF-BB increased more than five times compared to monolayer cultures. Encapsulated cells secreted about 80% active form of TGF-beta1 (monolayer cells only secreted inactive form). An enhanced secretion of TGF-beta1 and PDGF-BB was found in encapsulated cells, showing that fibrin capsules are favourable for the production of these growth factors.

Growth factor production from fibrin-encapsulated human keratinocytes.

A lot of effort has been developed to bypass the use of embryonic stem cells (ES) in human therapies, because of several concerns and ethical issues. Some unsolved problems of using stem cells for human therapies, excluding the human embryonic origin, are: how to regulate cell plasticity and proliferation, immunological compatibility, potential adverse side-effects when stem cells are systemically administrated, and the in vivo signals to rule out a specific cell fate after transplantation. Currently, it is known that almost all tissues of an adult organism have somatic stem cells (SSC). Whereas ES are primary involved in the genesis of new tissues and organs, SSC are involved in regeneration processes, immuno-regulatory and homeostasis mechanisms. Although the differentiating potential of ES is higher than SSC, several studies suggest that some types of SSC, such as mesenchymal stem cells (MSC), can be induced epigenetically to differentiate into tissue-specific cells of different lineages. This unexpected pluripotency and the variety of sources that they come from, can make MSC-like cells suitable for the treatment of diverse pathologies and injuries. New hopes for cell therapy came from somatic/mature cells and the discovery that could be reprogrammed to a pluripotent stage similar to ES, thus generating induced pluripotent stem cells (iPS). For this, it is necessary to overexpress four main reprogramming factors, Sox2, Oct4, Klf4 and c-Myc. The aim of this review is to analyze the potential and requirements of cellular based tools in human therapy strategies, focusing on the advantage of using MSC over iPS.

Cell therapy using induced pluripotent stem cells or somatic stem cells: this is the question.

Gelatin-/chitosan-/hyaluronan-based biomaterials are used in tissue engineering as cell scaffolds. Three gamma radiation doses (1, 10 and 25 kGy) were applied to scaffolds for sterilization. Microstructural changes of the irradiated polymers were evaluated by using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). A dose of 25 kGy produced a rough microstructure with a reduction of the porosity (from 99 to 96 %) and pore size (from 160 to 123 μm). Radiation also modified the glass transition temperature between 31.2 and 42.1 °C (1 and 25 kGy respectively). Human skin cells cultivated on scaffolds irradiated with 10 and 25 kGy proliferated at 48 h and secreted transforming growth factor β3 (TGF-β3). Doses of 0 kGy (non-irradiated) or 1 kGy did not stimulate TGF-β3 secretion or cell proliferation. The specific growth rate and lactate production increased proportionally to radiation dose. The use of an appropriate radiation dose improves the cell scaffold properties of biomaterials.

Improvement of human skin cell growth by radiation-induced modifications of a Ge/Ch/Ha scaffold.

Articular cartilage repair and regeneration provides a substantial challenge in Regenerative Medicine because of the high degree of morphological and mechanical complexity intrinsic to hyaline cartilage due, in part, to its extracellular matrix. Cartilage remains one of the most difficult tissues to heal; even state-of-the-art regenerative medicine technology cannot yet provide authentic cartilage resurfacing. Mesenchymal stem cells (MSCs) were once believed to be the panacea for cartilage repair and regeneration, but despite years of research, they have not fulfilled these expectations. It has been observed that MSCs have an intrinsic differentiation program reminiscent of endochondral bone formation, which they follow after exposure to specific reagents as a part of current differentiation protocols. Efforts have been made to avoid the resulting hypertrophic fate of MSCs; however, so far, none of these has recreated a fully functional articular hyaline cartilage without chondrocytes exhibiting a hypertrophic phenotype. We reviewed the current literature in an attempt to understand why MSCs have failed to regenerate articular cartilage. The challenges that must be overcome before MSC-based tissue engineering can become a front-line technology for successful articular cartilage regeneration are highlighted.

Chondrogenic differentiation of mesenchymal stem cells: challenges and unfulfilled expectations.

Mesenchymal stem cells (MSCs) can be isolated from dental tissues, such as pulp and periodontal ligament; the dental apical papilla (DAP) is a less-studied MSC source. These dental-derived MSCs are of great interest because of their potential as an accessible source for cell-based therapies and tissue-engineering (TE) approaches. Much of the interest regarding MSCs relies on the trophic-mediated repair and regenerative effects observed when they are implanted. TGFβ3 is a key growth factor involved in tissue regeneration and scarless tissue repair. We hypothesized that human DAP-derived MSCs (hSCAPs) can produce and secrete TGFβ3 in response to micro-environmental cues. For this, we encapsulated hSCAPs in different types of matrix and evaluated TGFβ3 secretion. We found that dynamic changes of cell-matrix interactions and mechanical stress that cells sense during the transition from a monolayer culture (two-dimensional, 2D) towards a three-dimensional (3D) culture condition, rather than the different chemical composition of the scaffolds, may trigger the TGFβ3 secretion, while monolayer cultures showed almost 10-fold less secretion of TGFβ3. The study of these interactions is provided as a cornerstone in designing future strategies in TE and cell therapy that are more efficient and effective for repair/regeneration of damaged tissues. Copyright © 2015 John Wiley & Sons, Ltd.

TGFβ3 secretion by three-dimensional cultures of human dental apical papilla mesenchymal stem cells.

Skeleton and liver are preferred organs for cancer dissemination in metastatic melanoma negatively impacting quality of life, therapeutic success and overall survival rates. At the target organ, the local microenvironment and cell-to-cell interactions between invading and resident stromal cells constitute critical components during the establishment and progression of metastasis. Mesenchymal stem cells (MSCs) possess, in addition to their cell progenitor function, a secretory capacity based on cooperativity with other cell types in injury sites including primary tumors (PT). However, their role at the target organ microenvironment during cancer dissemination is not known. We report that local MSCs, acting as pericytes, regulate the extravasation of melanoma cancer cells (MCC) specifically to murine bone marrow (BM) and liver. Intra-arterially injected wild-type MCC fail to invade those selective organs in a genetic model of perturbed pericyte coverage of the vasculature (PDGF-B(ret/ret)), similar to CD146-deficient MCC injected into wild type mice. Invading MCC interact with resident MSCs/pericytes at the perivascular space through co-expressed CD146 and Sdf-1/CXCL12-CXCR4 signaling. Implanted engineered bone structures with MSCs/pericytes deficient of either Sdf-1/CXCL12 or CD146 become resistant to invasion by circulating MCC. Collectively, the presence of MSCs/pericytes surrounding the target organ vasculature is required for efficient melanoma metastasis to BM and liver.

Mesenchymal stem cells regulate melanoma cancer cells extravasation to bone and liver at their perivascular niche.

Cellular differentiation comprises a progressive, multistep program that drives cells to fabricate a tissue with specific and site distinctive structural and functional properties. Cartilage constitutes one of the potential differentiation lineages that mesenchymal stem cells (MSCs) can follow under the guidance of specific bioactive agents. Single agents such as transforming growth factor beta (TGF-β) and bone morphogenetic protein 2 in unchanging culture conditions have been historically used to induce in vitro chondrogenic differentiation of MSCs. Despite the expression of traditional chondrogenic biomarkers such as type II collagen and aggrecan, the resulting tissue represents a transient cartilage rather than an in vivo articular cartilage (AC), differing significantly in structure, chemical composition, cellular phenotypes, and mechanical properties. Moreover, there have been no comprehensive, multicomponent parameters to define high-quality and functional engineered hyaline AC. To address these issues, we have taken an innovative approach based on the molecular interrogation of human neonatal articular cartilage (hNAC), dissected from the knees of 1-month-old cadaveric specimens. Subsequently, we compared hNAC-specific transcriptional regulatory elements and differentially expressed genes with adult human bone marrow (hBM) MSC-derived three-dimensional cartilage structures formed in vitro. Using microarray analysis, the transcriptome of hNAC was found to be globally distinct from the transient, cartilage-like tissue formed by hBM-MSCs in vitro. Specifically, over 500 genes that are highly expressed in hNAC were not expressed at any time point during in vitro human MSC chondrogenesis. The analysis also showed that the differences were less variant during the initial stages (first 7 days) of the in vitro chondrogenic differentiation program. These observations suggest that the endochondral fate of hBM-MSC-derived cartilage may be rerouted at earlier stages of the TGF-β-stimulated chondrogenic differentiation program. Based on these analyses, several key molecular differences (transcription factors and coded cartilage-related proteins) were identified in hNAC that will be useful as molecular inductors and identifiers of the in vivo AC phenotype. Our findings provide a new gold standard of a molecularly defined AC phenotype that will serve as a platform to generate novel approaches for AC tissue engineering.

Transcriptome-Wide Analyses of Human Neonatal Articular Cartilage and Human Mesenchymal Stem Cell-Derived Cartilage Provide a New Molecular Target for Evaluating Engineered Cartilage.

Rodrigo A. Somoza

Department of Biology - Skeletal Research Center

Case Western Reserve University

Ultrasound-guided Intracardiac Injection of Human Mesenchymal Stem Cells to Increase Homing to the Intestine for Use in Murine Models of Experimental Inflammatory Bowel Diseases

Rodrigo A. Somoza

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Biology - Skeletal Research Center

Case Western Reserve University

Ultrasound-guided Intracardiac Injection of Human Mesenchymal Stem Cells to Increase Homing to the Intestine for Use in Murine Models of Experimental Inflammatory Bowel Diseases

Department of Biology - Skeletal Research Center