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Concept: Mesenchyme



Isolated chondral defects have a limited capacity to heal and predispose to the development of osteoarthritis. Current surgical management can be unpredictable in outcome. Improved understanding of the action of mesenchymal stem cells (MSCs) has seen renewed interest in their role in cartilage repair. A 26-year-old athlete presented with a post-traumatic, isolated patella chondral defect. The patient underwent an arthroscopy with removal of a chondral loose body. After failure to symptomatically improve 12 months following surgery, the patient received intra-articular autologous adipose-derived mesenchymal stem cell (ADMSC) therapy.

Concepts: Bone, Osteoarthritis, Mesenchyme, Bone marrow, Stem cells, Knee, Mesenchymal stem cell, Stem cell


The majority of the protocols for cardiomyocyte differentiation of MSC use 5-azacytidine as an inducer. As transforming growth factor β1 and 5-azacytidine share similar target signaling pathways, we examined whether transforming growth factor β1 can play a role in cardiac differentiation process in human mesenchymal stem cell of bone marrow origin.

Concepts: Mesenchyme, Cell, Cell division, Stem cells, Cellular differentiation, Mesenchymal stem cell, Stem cell, Bone marrow


OBJECTIVE.: Fecal incontinence reduces the quality of life of many women but has no long-term cure. Research on mesenchymal stem cell (MSC)-based therapies has shown promising results. The primary aim of this study was to evaluate functional recovery after treatment with MSCs in two animal models of anal sphincter injury. METHODS.: Seventy virgin female rats received a sphincterotomy (SP) to model episiotomy, a pudendal nerve crush (PNC) to model the nerve injuries of childbirth, a sham SP, or a sham PNC. Anal sphincter pressures and electromyography (EMG) were recorded after injury but before treatment and 10days after injury. Twenty-four hours after injury, each animal received either 0.2ml saline or 2million MSCs labelled with green fluorescing protein (GFP) suspended in 0.2ml saline, either intravenously (IV) into the tail vein or intramuscularly (IM) into the anal sphincter. RESULTS.: MSCs delivered IV after SP resulted in a significant increase in resting anal sphincter pressure and peak pressure, as well as anal sphincter EMG amplitude and frequency 10days after injury. MSCs delivered IM after SP resulted in a significant increase in resting anal sphincter pressure and anal sphincter EMG frequency but not amplitude. There was no improvement in anal sphincter pressure or EMG with in animals receiving MSCs after PNC. GFP-labelled cells were not found near the external anal sphincter in MSC-treated animals after SP. CONCLUSION.: MSC treatment resulted in significant improvement in anal pressures after SP but not after PNC, suggesting that MSCs could be utilized to facilitate recovery after anal sphincter injury.

Concepts: Adipocyte, Mesenchyme, Sphincter, Defecation, Stem cells, Bone marrow, Stem cell, Mesenchymal stem cell


We researched the survival of bone marrow-derived mesenchymal stem cells (MSCs) and the results of MSCs' injected into decompensated bladders in a rabbit model.

Concepts: Cell biology, Adipocyte, Mesenchyme, Cell division, Stem cells, Bone marrow, Mesenchymal stem cell, Stem cell


It is currently controversially discussed whether mesenchymal stem cells (MSC) facilitate cartilage regeneration in vivo by a progenitor- or a nonprogenitor-mediated mechanism. Here, we describe a potentially novel unbiased in vivo cell tracking system based on transgenic donor and corresponding immunocompetent marker-tolerant recipient mouse and rat lines in inbred genetic backgrounds. Tolerance of recipients was achieved by transgenic expression of an immunologically neutral but physicochemically distinguishable variant of the marker human placental alkaline phosphatase (ALPP). In this dual transgenic system, donor lines ubiquitously express WT, heat-resistant ALPP protein, whereas recipient lines express a heat-labile ALPP mutant (ALPPE451G) resulting from a single amino acid substitution. Tolerance of recipient lines to ALPP-expressing cells and tissues was verified by skin transplantation. Using this model, we show that intraarticularly injected MSC contribute to regeneration of articular cartilage in full-thickness cartilage defects mainly via a nonprogenitor-mediated mechanism.

Concepts: Cell, Protein, Mesenchyme, Stem cells, Gene, Bone marrow, Mesenchymal stem cell, Stem cell


Division of large, immature alveolar structures into smaller, more numerous alveoli increases the surface area available for gas exchange. Alveolar division requires precise epithelial-mesenchymal interactions. However, few experimental models exist for studying how these cell-cell interactions produce changes in 3-dimensional structure. Here we report an epithelial-mesenchymal cell co-culture model where 3-dimensional peaks form with similar cellular orientation as alveolar structures in vivo. Co-culturing fetal mouse lung mesenchyme with A549 epithelial cells produced tall peaks of cells covered by epithelia with cores of mesenchymal cells. These structures did not form when using adult lung fibroblasts. Peak formation did not require localized areas of cell proliferation or apoptosis. Mesenchymal cells co-cultured with epithelia adopted an elongated cell morphology closely resembling myofibroblasts within alveolar septa in vivo. Because inflammation inhibits alveolar formation, we tested the effects of E. coli lipopolysaccharide on 3-dimensional peak formation. Confocal and time-lapse imaging demonstrated that lipopolysaccharide reduced mesenchymal cell migration, resulting in fewer, shorter peaks with mesenchymal cells present predominantly at the base. This epithelial-mesenchymal co-culture model may therefore prove useful in future studies of mechanisms regulating alveolar morphogenesis.

Concepts: Bone marrow, Endothelium, Stem cell, Lung, Developmental biology, Mesenchymal stem cell, Epithelium, Mesenchyme


Overgrowths of epithelial, ectomesenchymal, and/or mesenchymal elements of the tooth-forming apparatus are quite variable with respect to their histopathologic characteristics and biological behaviors. Investigations of a variety of odontogenic lesions have led to an enhanced comprehension of many salient diagnostic features. This discussion provides an update with respect to the understanding of odontogenic tumors and tumor-like malformations and attempts to assist pathologists in the recognition and classification of these lesions.

Concepts: Molecular biology, Greek loanwords, Mesenchymal stem cell, Understanding, Mesenchyme, Odontogenic, Pathology, Anatomical pathology


Galvanotaxis, the migratory response of cells in response to electrical stimulation, has been implicated in development and wound healing. The use of mesenchymal stem cells (MSCs) from the synovium (synovium-derived stem cells, SDSCs) has been investigated for repair strategies. Expansion of SDSCs is necessary to achieve clinically relevant cell numbers; however, the effects of culture passage on their subsequent cartilaginous extracellular matrix production are not well understood.

Concepts: Cell division, Mesenchyme, Extracellular matrix, Wound healing, Stem cells, Bone marrow, Mesenchymal stem cell, Stem cell


Impaired endogenous stem cell repair capacity is hypothesized to be a biologic basis of frailty. Therapies that restore regenerative capacity may therefore be beneficial. This Phase 1 study evaluated the safety and potential efficacy of intravenous, allogeneic, human mesenchymal stem cell (allo-hMSC)-based therapy in patients with aging frailty.

Concepts: Mesenchyme, Therapy?, Therapy, Cell, Stem cells, Bone marrow, Stem cell, Mesenchymal stem cell