Fusion Of Bone Marrow-derived Cells Research Articles

Aberrant cerebellar Purkinje cell function repaired in vivo by fusion with infiltrating bone marrow-derived cells

Bone marrow-derived cells are known to infiltrate the adult brain and fuse with cerebellar Purkinje cells. Histological observations that such heterotypic cell fusion events are substantially more frequent following cerebellar injury suggest they could have a role in the protection of mature brain neurons. To date, the possibility that cell fusion can preserve or restore the structure and function of adult brain neurons has not been directly addressed; indeed, though frequently suggested, the possibility of benefit has always been rather speculative. Here we report, for the first time, that fusion of a bone marrow-derived cell with a neuron in vivo, in the mature brain, results in the formation of a spontaneously firing neuron. Notably, we also provide evidence supporting the concept that heterotypic cell fusion acts as a biological mechanism to repair pathological changes in Purkinje cell structure and electrophysiology. We induced chronic central nervous system inflammation in chimeric mice expressing bone marrow cells tagged with enhanced green fluorescent protein. Subsequent in-depth histological analysis revealed significant Purkinje cell injury. In addition, there was an increased incidence of cell fusion between bone marrow-derived cells and Purkinje cells, revealed as enhanced green fluorescent protein-expressing binucleate heterokaryons. These fused cells resembled healthy Purkinje cells in their morphology, soma size, ability to synthesize the neurotransmitter gamma-aminobutyric acid, and synaptic innervation from neighbouring cells. Extracellular recording of spontaneous firing ex vivo revealed a shift in the predominant mode of firing of non-fused Purkinje cells in the context of cerebellar inflammation. By contrast, the firing patterns of fused Purkinje cells were the same as in healthy control cerebellum, indicating that fusion of bone marrow-derived cells with Purkinje cells mitigated the effects of cell injury on electrical activity. Together, our histological and electrophysiological results provide novel fundamental insights into physiological processes by which nerve cells are protected in adult life.

Cell Fusion along the Anterior-Posterior Neuroaxis in Mice with Experimental Autoimmune Encephalomyelitis.

BackgroundIt is well documented that bone marrow-derived cells can fuse with a diverse range of cells, including brain cells, under normal or pathological conditions. Inflammation leads to robust fusion of bone marrow-derived cells with Purkinje cells and the formation of binucleate heterokaryons in the cerebellum. Heterokaryons form through the fusion of two developmentally differential cells and as a result contain two distinct nuclei without subsequent nuclear or chromosome loss.AimIn the brain, fusion of bone marrow-derived cells appears to be restricted to the complex and large Purkinje cells, raising the question whether the size of the recipient cell is important for cell fusion in the central nervous system. Purkinje cells are among the largest neurons in the central nervous system and accordingly can harbor two nuclei.ResultsUsing a well-characterized model for heterokaryon formation in the cerebellum (experimental autoimmune encephalomyelitis - a mouse model of multiple sclerosis), we report for the first time that green fluorescent protein-labeled bone marrow-derived cells can fuse and form heterokaryons with spinal cord motor neurons. These spinal cord heterokaryons are predominantly located in or adjacent to an active or previously active inflammation site, demonstrating that inflammation and infiltration of immune cells are key for cell fusion in the central nervous system. While some motor neurons were found to contain two nuclei, co-expressing green fluorescent protein and the neuronal marker, neuron-specific nuclear protein, a number of small interneurons also co-expressed green fluorescent protein and the neuronal marker, neuron-specific nuclear protein. These small heterokaryons were scattered in the gray matter of the spinal cord.ConclusionThis novel finding expands the repertoire of neurons that can form heterokaryons with bone marrow-derived cells in the central nervous system, albeit in low numbers, possibly leading to a novel therapy for spinal cord motor neurons or other neurons that are compromised in the central nervous system.

Establishment of circulating tumor cell lines

The specificity of circulating tumor cell (CTC) such as epithelial-mesenchymal transition,fusion of bone marrow-derived cells,resistance anoikis determines the necessity of cell cultivating.The produced cell lines can provide good material basis for further research of malignant tumor metastasis,also provide individualized targeted therapy for patients with a new direction. Key words: Neoplasm circulating cells; Cell culture techniques; Cell line, tumor

Fusion of bone marrow-derived cells with cancer cells: metastasis as a secondary disease in cancer

This perspective article highlights the leukocyte-cancer cell hybrid theory as a mechanism for cancer metastasis. Beginning from the first proposal of the theory more than a century ago and continuing today with the first proof for this theory in a human cancer, the hybrid theory offers a unifying explanation for metastasis. In this scenario, leukocyte fusion with a cancer cell is a secondary disease superimposed upon the early tumor, giving birth to a new, malignant cell with a leukocyte-cancer cell hybrid epigenome.

Mild Cerebellar Neurodegeneration of Aged Heterozygous PCD Mice Increases Cell Fusion of Purkinje and Bone Marrow-Derived Cells

Bone marrow-derived cells have different plastic properties, especially regarding cell fusion, which increases with time and is prompted by tissue injury. Several recessive mutations, including Purkinje Cell Degeneration, affect the number of Purkinje cells in homozygosis; heterozygous young animals have an apparently normal phenotype but they undergo Purkinje cell loss as they age. Our findings demonstrate that heterozygous pcd mice undergo Purkinje cell loss at postnatal day 300, this slow but steadily progressing cell death starting sooner than has been reported previously and without massive reactive gliosis or inflammation. Here, transplantation of bone marrow stem cells was performed to assess the arrival of bone marrow-derived cells in the cerebellum in these heterozygous mice. Our results reveal that a higher number of cell fusion events occurs in heterozygous animals than in the controls, on days 150 and 300 postnatally. In sum, this study indicates that mild cell death promotes the fusion of bone marrow-derived cells with surviving Purkinje neurons. This phenomenon suggests new therapies for long-lasting neurodegenerative disorders.

Phenotypic characteristics of hybrid cells produced by cell fusion of porcine adrenal chromaffin cells with human mesenchymal stem cells: a preliminary study

Background and purpose: Transplantation of adrenal chromaffin cells (CCs) that release endogenous opioid peptides and catecholamines produces significant antinociceptive effects in patients with terminal cancer pain. In clinical practice, however, obtaining a sufficient number of chromaffin cells may not be possible because of the limited availability of human adrenal tissue. Recent works have shown that fusion of bone marrow-derived cells with differentiated cells can occur spontaneously in vivo and acquire the phenotype of the recipient cells. In this study, we investigated the possibility of producing chromaffin-like cells by fusing human bone marrow-derived mesenchymal stem cells (MeSCs) with post-mitotic porcine CCs in vitro with the application of polyethylene glycol (PEG).Methods and results: Before cell-to-cell fusion was initiated, MeSCs and CCs were labeled by fluorescence dyes DiO (green) and Dil (red), respectively. The hybrid cells generated by PEG-mediated fusion expressed a DiO and Dil double-staining with estimated fusion efficiency at ∼40% of the total cell population. Further immunocytochemical examination for tyrosine hydroxylase and methionine enkephalin (markers for CCs) demonstrated positive immuno-reactivity in these hybrid cells 2 weeks post-fusion. More interestingly, some of the hybrid cells showed bromodeoxyuridine (BrdU)-positive immunostaining in the nuclei.Discussion: Our results show that these hybrid cells fused by CCs and MeSCs express some characteristics of the CC phenotype. A subpopulation of these hybrid cells are dividing cells with positive BrdU immunostaining, suggesting that a novel cellular production could be developed by a "reprogramming" mechanism through the application of targeted cell fusion strategies.

Bone marrow progenitor cells contribute to repair and remodeling of the lung and heart in a rat model of progressive pulmonary hypertension

Infusion of bone marrow stem or progenitor cells may provide powerful therapies for injured tissues such as the lung and heart. We examined the potential of bone marrow-derived (BMD) progenitor cells to contribute to repair and remodeling of lung and heart in a rat monocrotaline (MCT) model of pulmonary hypertension. Bone marrow from green fluorescent protein (GFP)-transgenic male rats was transplanted into GFP-negative female rats. The chimeric animals were injected with MCT to produce pulmonary hypertension. Significant numbers of male GFP-positive BMD cells engrafted in the lungs of MCT-treated rats. Microarray analyses and double-immunohistochemistry demonstrated that many of the cells were interstitial fibroblasts or myofibroblasts, some of the cells were hematopoietic cells, and some were pulmonary epithelial cells (Clara cells), vascular endothelial cells, and smooth muscle cells. A few BMD cells fused with pulmonary cells from the host, but the frequency was low. In the hypertrophied hearts of MCT-treated rats, we found a significant increase in the relative numbers of BMD cells in the right ventricle wall as compared with the left ventricle. Some of the BMD cells in the right ventricle were vascular cells and cardiomyocytes. We report BMD cardiomyocytes with a normal chromosome number, fusion of BMD cells with host cardiomyocytes, and, in some cases, nuclear fusion.

Induction and Survival of Binucleated Purkinje Neurons by Selective Damage and Aging

Fusion of bone marrow-derived cells with adult Purkinje cells in the cerebellum gives rise to binucleated Purkinje cells. Whether fusion can be modulated by epigenetic factors and whether fused neurons are stable has remained unclear. Here, we show that in mice and rats, partial ablation of Purkinje cells and local microglial activation in the absence of structural damage to the cerebellum increase the rate of fusion. Moreover, mouse Purkinje cells once fused with bone marrow-derived cells are viable for at least 7 months. We also show that cerebellar irradiation is unnecessary for the generation of binucleated Purkinje cells after bone marrow grafting. Moreover, binucleated Purkinje cells can be found in aged mice that did not receive any treatment, suggesting that fusion events occasionally occur throughout the whole lifespan of healthy, unmanipulated individuals. However, in aged chimeric mice that, after bone marrow transplant, have the majority of their nucleated blood cells fluorescent, the number of binucleated fluorescent Purkinje cells is two orders of magnitude less than the total number of binucleated Purkinje cells. This suggests that, in the majority of heterokaryons, either the incoming nucleus is quickly inactivated or fusion is not the only way to generate a binucleated Purkinje cell.

Bone marrow-derived cells fuse with normal and transformed intestinal stem cells

Transplanted adult bone marrow-derived cells (BMDCs) have been shown to adopt the phenotype and function of several nonhematopoietic cell lineages and promote tumorigenesis. Beyond its cancer enhancing potential, cell fusion has recently emerged as an explanation of how BMDCs regenerate diseased heptocytes, contribute to Purkinje neurons and skeletal and cardiac muscle cells, and participate in skin and heart regeneration. Although bone marrow-derived epithelial cells also have been observed in the intestine, fusion as a mechanism has not been investigated. Here, we show that transplanted BMDCs fuse with both normal and neoplastic intestinal epithelium. Long-term repopulation by donor-derived cells was detected in all principal intestinal epithelial lineages including enterocytes, goblet cells, Paneth cells, and enteroendocrine cells, suggesting that the fusion partners of the BMDCs are long-lived intestinal progenitors or stem cells. Fusion of BMDCs with neoplastic epithelium did not result in tumor initiation. Our findings suggest an unexpected role for BMDCs in both regeneration and tumorigenesis of the intestine.

Bone Marrow-Derived Cells Contribute to Epithelial Engraftment during Wound Healing

Recent findings suggest that bone marrow-derived cells (BMDC) may contribute to tissue maintenance throughout the body. However, it is not yet known whether marrow-derived epithelial cells are capable of undergoing proliferation. Our laboratory has shown that BMDC engraft as keratinocytes in the skin at low levels (</= 1%) in the absence of injury. Here we show that skin damage affects the degree of engraftment of BMDC as keratinocytes and that the keratinocytes are actively cycling. Female mice reconstituted with sex-mismatched BM were wounded by punch biopsy and incision. At the wound site, engraftment of BMDC as epidermal cells increased within 1 day, and continued to increase to approximately 4% by 3 weeks after injury. Using a Cre-lox system, fusion of BMDC with epithelial cells was ruled out. BMDC-derived epithelial cells at the wound edges expressed Ki67, a marker for actively cycling cells, and this proliferation correlated with an increase in the number of donor-derived cells within the wound. Donor-derived cytokeratin 5-expressing cells were rare, suggesting that BMDC do not engraft as epidermal stem cells, and the level of engraftment peaked and then decreased over time, further suggesting that BMDC may assist in early wound healing by engrafting as transit-amplifying cells, which then differentiate into keratinocytes.