Transplantation Of Fibroblasts Research Articles

Transplantation of Cultivated Fibroblasts on a Backing of Xenogenic Tissue in the Treatment of Wounds.

IntroductionTrophic ulcers are a common health problem, and there are numerous treatment methods. Irreversible damage in the skin, subcutaneous tissue, and fascia with long-term ulcer existence make standard autotransplantation inneffective. Skin grafts are often complicated by partial or complete rejection of skin flaps. The aim of this study was to examine the feasibility of using transplanted cultivated allogenic fibroblasts on the backing of a cellularless xenogenic fabric for wound healing.MethodsTransplantation of cultured embryonic fibroblasts on a backing of xenogenic tissue was used in the complex treatment of trophic ulcers for stimulation of regenerative processes. Decellularization xenogenic film was previously held. Then allogenic fibroblasts were cultivated on the surface of collagen-elastin matrix. Since 2013, we treated 12 patients with giant ulcers caused by the following: lymphedema (2 patients), vascular disease (3 patients), diabetes (2 patients), after injury (4 patients), and radiation ulcer (1 patient). Dimensions of ulcers were from 150 to 600 cm2. Duration of the lower limb ulcers ranged from 8 months to 10 years. For a number of years, all patients were on a complex therapy, which had not resulted in healing wounds. During the operation when excision of granulation tissue was performed, plastic wounds perforated with the ratio 1:2 autoskin. Xenogenic fabric with cultured fibroblasts was applied on top. In this case, xenogenic film protected the skin from drying, created optimal microclimate, and cultured fibroblasts stimulating regeneration and improving engraftment.ResultsThe first redress was held on the fifth day. In all cases, the results of engraftment skin grafts achieved maximum possible (100%) and optimal (90%). Complete epithelialization of the cell perforation was seen in five patients on the fifth day and three on seventh day after skin plastics. Average period of inpatient treatment was 20.7 days. All patients were discharged with healed wounds.ConclusionThus, the treatment of trophic ulcers can be successfully solved using advances in biotechnology. Transplantation of cultivated allogenic fibroblasts on a backing of cellularless xenogenic fabric shows good clinical results due to the stimulation of regenerative processes and creates the optimum environment for autotransplants.

Delayed animal aging through the recovery of stem cell senescence by platelet rich plasma

Aging is related to loss of functional stem cell accompanying loss of tissue and organ regeneration potentials. Previously, we demonstrated that the life span of ovariectomy-senescence accelerated mice (OVX-SAMP8) was significantly prolonged and similar to that of the congenic senescence-resistant strain of mice after platelet rich plasma (PRP)/embryonic fibroblast transplantation. The aim of this study is to investigate the potential of PRP for recovering cellular potential from senescence and then delaying animal aging. We first examined whether stem cells would be senescent in aged mice compared to young mice. Primary adipose derived stem cells (ADSCs) and bone marrow derived stem cells (BMSCs) were harvested from young and aged mice, and found that cell senescence was strongly correlated to animal aging. Subsequently, we demonstrated that PRP could recover cell potential from senescence, such as promote cell growth (cell proliferation and colony formation), increase osteogenesis, decrease adipogenesis, restore cell senescence related markers and resist the oxidative stress in stem cells from aged mice. The results also showed that PRP treatment in aged mice could delay mice aging as indicated by survival, body weight and aging phenotypes (behavior and gross morphology) in term of recovering the cellular potential of their stem cells compared to the results on aged control mice. In conclusion these findings showed that PRP has potential to delay aging through the recovery of stem cell senescence and could be used as an alternative medicine for tissue regeneration and future rejuvenation.

Allogenous skin fibroblast transplantation enhances excisional wound healing following alloxan diabetes in sheep, a randomized controlled trial

BackgroundHealing of skin wound is a multi-factorial and complex process. Treatment of diabetic wounds is still a major clinical challenge. Recently, stem cell transplantation to chronic wounds is favored. The objective of this study was to evaluate effects of pre-labeled allogenous skin fibroblasts on healing of ovine diabetic wound model. MethodsEight 4-month-old Iranian Makoui wethers were used in this study. Alloxan monohydrate was used for induction of diabetes. In each wether two excisional wound were created on dorsum of the animal. Wounds of one side were randomly chosen as treatment group (n = 8), and wounds of the other side were considered as control group (n = 8). Pre-labeled skin fibroblasts with bromodeoxyuridine were used in wounds of one side as treatment. Photographs were taken in distinct times for planimetric evaluation. Wound samples were taken for BrdU detection and histopathologic evaluations on day 21 post-wounding. ResultsThe planimetric study showed closure of fibroblast treated wounds is significantly faster than control group (P < 0.05). Immunohistochemical staining with anti-bromodeoxyuridine antibody indicated presence of transplanted cells in the wounds. Histopathologic evaluations of H&E stained sections disclosed significantly increasing of re-epithelialization, number of fibroblasts, and number of blood vessels in treatment group in comparison to control group (P < 0.05). ConclutionThe results of this study indicated that allogenous skin fibroblast transplantation can positively affect wound healing in diabetic sheep.

Transplantation of Cyclic Stretched Fibroblasts Accelerates the Wound-Healing Process in Streptozotocin-Induced Diabetic Mice

Mechanical stimulation is a known modulator of survival and proliferation for many cells, including endothelial cells, smooth muscle cells, and bone marrow-derived mesenchymal stem cells. In this study, we found that mechanical strain prevents apoptosis and increases the adhesive ability of dermal fibroblasts in vitro and thus confers the survival advantage in vivo after transplantation of fibroblasts into the full-thickness wound of diabetic mice. Cyclic stretch at a frequency of 0.5 Hz and maximum elongation of 20% stimulates cellular survival mediated by the activation of extracellular signal-regulated kinases (ERKs), c-Jun N-terminal kinases (JNKs), and the serine/threonine kinase Akt (AKT). Stretching of the fibroblasts increases the synthesis of extracellular matrix proteins and the formation of denser focal adhesion structures, both of which are required for fibroblast adhesion. The stretched fibroblasts also upregulate the expression of vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1α (SDF-1α), which enhanced wound healing in vivo. Indeed, preconditioning with mechanical stretch allows better survival of the transplanted fibroblasts, when compared to unstretched control cells, in the wound environment of mice with streptozotocin-induced diabetes and thus accelerates the wound-healing process in these mice.

Skin Electroporation of a Plasmid Encoding hCAP-18/LL-37 Host Defense Peptide Promotes Wound Healing

Host defense peptides, in particular LL-37, are emerging as potential therapeutics for promoting wound healing and inhibiting bacterial growth. However, effective delivery of the LL-37 peptide remains limiting. We hypothesized that skin-targeted electroporation of a plasmid encoding hCAP-18/LL-37 would promote the healing of wounds. The plasmid was efficiently delivered to full-thickness skin wounds by electroporation and it induced expression of LL-37 in the epithelium. It significantly accelerated reepithelialization of nondiabetic and diabetic wounds and caused a significant VEGFa and interleukin (IL)-6 induction. IL-6 was involved in LL-37-mediated keratinocyte migration in vitro and IL-6 neutralizing antibodies delivered to mice were able to suppress the wound healing activity of the hCAP-18/LL-37 plasmid. In a hindlimb ischemia model, electroporation of the hCAP-18/LL-37 plasmid increased blood perfusion, reduced muscular atrophy, and upregulated the angiogenic chemokines VEGFa and SDF-1a, and their receptors VEGF-R and CXCR-4. These findings demonstrate that a localized gene therapy with LL-37 is a promising approach for the treatment of wounds.

Cell type specific interleukin-6 induced responses in tumor keratinocytes and stromal fibroblasts are essential for invasive growth

Interleukin-6 (IL-6) is one of the major inflammatory interleukins that has been linked to cancer progression. In our model for human skin squamous cell carcinoma (SCC), IL-6 expression is strongly upregulated upon progression from benign tumors to highly malignant, metastasizing SCCs. We now demonstrate that IL-6 promotes malignant and invasive tumor growth in human skin SCCs by inducing cell type specific cytokine profiles in tumor keratinocytes and stromal fibroblasts, activating the latter towards a tumor associated fibroblast (TAF) phenotype. In three-dimensional organotypic cocultures in vitro invasive growth of IL-6 overexpressing tumor keratinocytes, is associated with increased expression of matrix metalloproteinase-2 (MMP-2), MMP-14 and tissue inhibitor of metalloproteinases-2, and clearly depends on IL-6 activated fibroblasts. IL-6-induced secretion of monocyte chemotactic protein-1 (MCP-1) in tumor keratinocytes and of hepatocyte growth factor in fibroblasts is crucial for regulating expression and activation of MMP-2. This functional role of IL-6 is confirmed in vivo. Here MMP-14 and MMP-2 expression occur exclusively in surface transplants of IL-6 overexpressing keratinocytes and fibroblasts are identified as important source of MMP-2. Our data indicate that tumor keratinocytes derived IL-6 activates stromal fibroblasts towards a TAF phenotype, promoting tumor invasion via enhanced expression and activation of MMP-2.

Autologous fibroblast transplantation

As the main functional cells in dermis,fibroblasts play an important role in the anti-aging process of skin.Basic studies have demonstrated high survival rate and favorable safety of transplanted autologous fibroblasts.The vitality and function of transplanted fibroblasts are affected by multiple factors,including microenvironment,other dermal cells,genes,proteins and even cytokines.Besides,clinical trials have shown that autologous cultured fibroblast transplantation is effective for the improvement of wrinkles,depressed scars,and even ulcers. Key words: Fibroblasts; Transplantation,autologous; Cell culture techniques

Transplantation of Autologous Olfactory Ensheathing Cells in Complete Human Spinal Cord Injury

Numerous studies in animals have shown the unique property of olfactory ensheathing cells to stimulate regeneration of lesioned axons in the spinal cord. In a Phase I clinical trial, we assessed the safety and feasibility of transplantation of autologous mucosal olfactory ensheathing cells and olfactory nerve fibroblasts in patients with complete spinal cord injury. Six patients with chronic thoracic paraplegia (American Spinal Injury Association class A-ASIA A) were enrolled for the study. Three patients were operated, and three served as a control group. The trial protocol consisted of pre- and postoperative neurorehabilitation, olfactory mucosal biopsy, culture of olfactory ensheathing cells, and intraspinal cell grafting. Patient's clinical state was evaluated by clinical, neurophysiological, and radiological tests. There were no adverse findings related to olfactory mucosa biopsy or transplantation of olfactory ensheathing cells at 1 year after surgery. There was no evidence of neurological deterioration, neuropathic pain, neuroinfection, or tumorigenesis. In one cell-grafted patient, an asymptomatic syringomyelia was observed. Neurological improvement was observed only in transplant recipients. The first two operated patients improved from ASIA A to ASIA C and ASIA B. Diffusion tensor imaging showed restitution of continuity of some white matter tracts throughout the focus of spinal cord injury in these patients. The third operated patient, although remaining ASIA A, showed improved motor and sensory function of the first spinal cords segments below the level of injury. Neurophysiological examinations showed improvement in spinal cord transmission and activity of lower extremity muscles in surgically treated patients but not in patients receiving only neurorehabilitation. Observations at 1 year indicate that the obtaining, culture, and intraspinal transplantation of autologous olfactory ensheathing cells were safe and feasible. The significance of the neurological improvement in the transplant recipients and the extent to which the cell transplants contributed to it will require larger numbers of patients.

Skeletal myoblast transplantation on gene expression profiles of insulin signaling pathway and mitochondrial biogenesis and function in skeletal muscle

AimThe study aims to investigate the gene expression profiling of insulin signaling pathway and mitochondrial biogenesis and function in the skeletal muscle of KK mice. MethodsKK mice were divided into the following groups: KK control group, basal medium (M199) only; KK fibroblast group, with human fibroblast transplantation; KK myoblast group, with human skeletal myoblast transplantation. C57BL mice received hSkM transplantation as a normal control. Cells were transplanted into mice hind limb skeletal muscle. All animals were treated with cyclosporine for 6 weeks only. The mice were sacrificed in a fasting state at 12 weeks after treatment. Hind limb skeletal muscle was harvested and used for study of gene expression profiling. ResultshSkMs survived extensively in mice skeletal muscle at 12 weeks after cell transplantation. Glucose tolerance test showed a significant decrease of blood glucose in the mice of KK myoblast group compared to the KK control and fibroblast groups. Transcriptional patterns of insulin signaling pathway showed alterations in KK myoblast as compared with KK control group (23 genes), KK fibroblast group (7 genes), and C57BL group (8 genes). Transcriptional patterns of mitochondrial biogenesis and function also had alterations in KK myoblast as compared with KK control group (27 genes), KK fibroblast group (9 genes), and C57BL group (6 genes). ConclusionsThese data demonstrated for the first time that hSKM transplantation resulted in a change of gene transcript in multiple genes involved in insulin signaling pathway and mitochondrial biogenesis and function.

A multilevel screening strategy defines a molecular fingerprint of proregenerative olfactory ensheathing cells and identifies SCARB2, a protein that improves regenerative sprouting of injured sensory spinal axons.

Olfactory ensheathing cells (OECs) have neuro-restorative properties in animal models for spinal cord injury, stroke, and amyotrophic lateral sclerosis. Here we used a multistep screening approach to discover genes specifically contributing to the regeneration-promoting properties of OECs. Microarray screening of the injured olfactory pathway and of cultured OECs identified 102 genes that were subsequently functionally characterized in cocultures of OECs and primary dorsal root ganglion (DRG) neurons. Selective siRNA-mediated knockdown of 16 genes in OECs (ADAMTS1, BM385941, FZD1, GFRA1, LEPRE1, NCAM1, NID2, NRP1, MSLN, RND1, S100A9, SCARB2, SERPINI1, SERPINF1, TGFB2, and VAV1) significantly reduced outgrowth of cocultured DRG neurons, indicating that endogenous expression of these genes in OECs supports neurite extension of DRG neurons. In a gain-of-function screen for 18 genes, six (CX3CL1, FZD1, LEPRE1, S100A9, SCARB2, and SERPINI1) enhanced and one (TIMP2) inhibited neurite growth. The most potent hit in both the loss- and gain-of-function screens was SCARB2, a protein that promotes cholesterol secretion. Transplants of fibroblasts that were genetically modified to overexpress SCARB2 significantly increased the number of regenerating DRG axons that grew toward the center of a spinal cord lesion in rats. We conclude that expression of SCARB2 enhances regenerative sprouting and that SCARB2 contributes to OEC-mediated neuronal repair.

Enhanced neuroregenerative effects by scaffold for the treatment of a rat spinal cord injury with Wnt3a-secreting fibroblasts

Wnt proteins are bifunctional axon guidance molecules, several of which appear to mediate guidance of corticospinal tract axons along the spinal cord. Here, we studied increasing effect on regeneration by Wnt-containing alginate scaffolds on spinal cord injury (SCI). A total of 32 rats were injured at the T7-8 level with an NYU impactor. According to transplantation materials, rats were classified into four groups: a Wnt3a-secreting fibroblast transplantation group (Wnt group, n = 8), a Wnt3a-secreting fibroblast with alginate transplantation group (Wnt + alginate group, n = 8), an alginate transplantation group (alginate group, n = 8), and a contusion-only group (sham group, n = 8). Behavioral tests were performed on the first, second, and third days after injury, and then weekly for 8 weeks. Five of the eight rats from each group were selected for manganese-enhanced magnetic resonance imaging (ME-MRI). Two rats from each group were examined for GAP43 and MAP2 expression using monoclonal and polyclonal primary antibodies, respectively. Seven weeks after transplantation (8 weeks after SCI), Wnt + alginate group rats achieved an average Basso-Beattie-Bresnahan locomotor score of 19.0, which was significantly higher than that of other groups. ME-MRI at 8 weeks after SCI revealed significantly higher relative signal intensities in the Wnt + alginate group. Gap43 and Map2 immunostaining, showed strong positive in the Wnt + alginate group. The Wnt + alginate complex exerted significantly enhanced recovery in a rat SCI model compared to alginate or Wnt3a alone. These results suggest that alginate scaffolds facilitate the regeneration of axon working with Wnt3a protein that promotes regeneration of the injured spinal cord.

Transplantation of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells or Their Conditioned Medium Prevents Bone Loss in Ovariectomized Nude Mice

Umbilical cord blood (UCB) has recently been recognized as a new source of mesenchymal stem cells (MSCs) for use in stem cell therapy. We studied the effects of systemic injection of human UCB-MSCs and their conditioned medium (CM) on ovariectomy (OVX)-induced bone loss in nude mice. Ten-week-old female nude mice were divided into six groups: Sham-operated mice treated with vehicle (Sham-Vehicle), OVX mice subjected to UCB-MSCs (OVX-MSC), or human dermal fibroblast (OVX-DFB) transplantation, OVX mice treated with UCB-MSC CM (OVX-CM), zoledronate (OVX-Zol), or vehicle (OVX-Vehicle). Although the OVX-Vehicle group exhibited significantly less bone mineral density (BMD) gain compared with the Sham-Vehicle group, transplantation of hUCB-MSCs (OVX-MSC group) has effectively prevented OVX-induced bone mass attenuation. Notably, the OVX-CM group also showed BMD preservation comparable to the OVX-MSC group. In addition, microcomputed tomography analysis demonstrated improved trabecular parameters in both the OVX-MSC and OVX-CM groups compared to the OVX-Vehicle or OVX-DFB group. Histomorphometric analysis showed increased bone formation parameters, accompanied by increased serum procollagen type-I N-telopeptide levels in OVX-MSC and OVX-CM mice. However, cell-trafficking analysis failed to demonstrate engraftment of MSCs in bone tissue 48 h after cell infusion. In vitro, hUCB-MSC CM increased alkaline phosphatase (ALP) activity in human bone marrow-derived MSCs and mRNA expression of collagen type 1, Runx2, osterix, and ALP in C3H10T1/2 cells. Furthermore, hUCB-MSC CM significantly increased survival of osteocyte-like MLO-Y4 cells, while it inhibited osteoclastic differentiation. To summarize, transplantation of hUCB-MSCs could effectively prevent OVX-mediated bone loss in nude mice, which appears to be mediated by a paracrine mechanism rather than direct engraftment of the MSCs.

Electroacupuncture and Lumbar Transplant of GDNF-Secreting Fibroblasts Synergistically Attenuate Hyperalgesia after Sciatic Nerve Constriction

Electroacupuncture (EA) has been shown to induce potent analgesic effects on neuropathic pain in both patients and rodents. Cell therapy to release antinociceptive agents near the pain processing centers of the spinal cord is a promising next step in the development of treatment modalities. This study investigated the effects of the combination of EA and cell therapy by glial cell line-derived neurotrophic factor (GDNF) on neuropathic pain in rats. The hyperalgesic state was induced by chronic constriction injury (CCI) of the sciatic nerve and fibroblasts genetically modified to secrete bioactive GDNF (FBs-GDNF) were used for cell therapy. Fifty-eight rats with neuropathic pain were randomly divided into five groups (CCI+PBS, n = 11; CCI+FBs-GDNF, n = 12; CCI+EA+PBS, n = 11; CCI+EA+FBs-pLNCX2, n = 12; CCI+EA+FBs-GDNF, n = 12). On the 7th day after CCI, the rats received intrathecal transplantation of FBs-GDNF or control fibroblasts (FBs-pLNCX2). In the meantime, EA was administered once every other day from the 7th day after CCI surgery for 21 days. The paw withdrawal latency (PWL) to radiant heat was measured every other day. The results showed that the ipsilateral PWL of the rats from all three EA treatment groups significantly increased starting on the 12th day compared with the PBS control group. Strikingly, the group which received EA treatment and FBs-GDNF transplantation (CCI+EA+FBs-GDNF) showed a significantly decreased thermal hyperalgesia after 2 weeks post CCI surgery compared with the groups which received EA treatment and FBs-pLNCX2 transplantation (CCI+EA+FBs-pLNCX2) or PBS (CCI+EA+PBS) as well as the FBs-GDNF transplantation group without EA treatment (CCI+FBs-GDNF). Our data suggest that EA and cell therapy can synergistically attenuate hyperalgesia in neuropathic pain rats.

Brain-Derived Neurotrophic Factor-Transfected and Nontransfected 3T3 Fibroblasts Enhance Migratory Neuroblasts and Functional Restoration in Mice With Intracerebral Hemorrhage

Neurogenesis via the activation of endogenous neural progenitor cells is a potential treatment strategy for brain injury, including intracerebral hemorrhage (ICH). We assessed the efficacy of combined cell and brain-derived neurotrophic factor (BDNF) treatment in a mouse model of ICH induced by intracerebral collagenase injection. Complementary DNAs of mouse BDNF were transfected into cell lines of 3T3 fibroblasts. The expression and bioactivity of BDNF were analyzed by immunocytochemistry, Western blot, ELISA, and functional assays. Hematoma area and brain tissue loss were assessed by magnetic resonance imaging. The BDNF-transfected or nontransfected 3T3 fibroblasts were implanted as a growth factor source in mice with ICH. Neurogenesis and functional recovery were evaluated 15 days after ICH. The BDNF-treated mice had the most doublecortin-positive cells near lesions and the least brain tissue loss in all groups. Both cell treatment groups had abundant newly proliferative glial fibrillary acidic protein-positive cells and better functional improvement than controls. These results indicate that fibroblast transplantation, together with recombinant BDNF treatment, after ICH is beneficial in mice. The early functional recovery may result from the growth factors that are provided or evoked by the implanted grafts. These results suggest a potential approach for combining gene and cell therapy for ICH treatment.

The Heme Oxygenase 1 Inducer (CoPP) Protects Human Cardiac Stem Cells against Apoptosis through Activation of the Extracellular Signal-regulated Kinase (ERK)/NRF2 Signaling Pathway and Cytokine Release

Intracoronary delivery of c-kit-positive human cardiac stem cells (hCSCs) is a promising approach to repair the infarcted heart, but it is severely limited by the poor survival of donor cells. Cobalt protoporphyrin (CoPP), a well known heme oxygenase 1 inducer, has been used to promote endogenous CO generation and protect against ischemia/reperfusion injury. Therefore, we determined whether preconditioning hCSCs with CoPP promotes CSC survival. c-kit-positive, lineage-negative hCSCs were isolated from human heart biopsies. Lactate dehydrogenase release assays demonstrated that preconditioning CSCs with CoPP markedly enhanced cell survival after oxidative stress induced by H(2)O(2), concomitant with up-regulation of heme oxygenase 1, COX-2, and anti-apoptotic proteins (BCL2, BCL2-A1, and MCL-1) and increased phosphorylation of NRF2. Apoptotic cytometric assays showed that pretreatment of CSCs with CoPP enhanced the cells' resistance to apoptosis induced by oxidative stress. Conversely, knocking down HO-1, COX-2, or NRF2 by shRNA gene silencing abrogated the cytoprotective effects of CoPP. Further, preconditioning CSCs with CoPP led to a global increase in release of cytokines, such as EGF, FGFs, colony-stimulating factors, and chemokine ligand. Conditioned medium from cells pretreated with CoPP conferred naive CSCs remarkable resistance to apoptosis, demonstrating that cytokines released by preconditioned cells play a key role in the anti-apoptotic effects of CoPP. Preconditioning CSCs with CoPP also induced an increase in the phosphorylation of Erk1/2, which are known to modulate multiple pro-survival genes. These results potentially provide a simple and effective strategy to enhance survival of CSCs after transplantation and, therefore, their efficacy in repairing infarcted myocardium.

Autologous fibroblast transplantation at the vesico-ureteral junction as potential reconstructive cell replacement in an animal model

To evaluate the cellular survival of donor fibroblasts after transplantation at the vesico-ureteral junction (VUJ) and to analyse their potential for reconstructive cell replacement in an animal model as autologous fibroblasts have been used as soft tissue augmentation material for scared and damaged tissue. Muscles biopsies were procured from the lower limb muscles of 4 pigs; cytoplasm of fibroblasts was labelled with nano-sized iron oxide particles. Six weeks after taking of the muscle biopsies, fibroblast transplantation was performed, 3×10(6) cells suspended in transplantation medium (in 1-ml syringes) were injected at the VUJ using the modified STING technique. Animals were killed 8weeks later; seeded fibroblasts were identified using prussian blue staining protocol; histological evaluation and morphological analysis were performed by light microscopy (Mayer's haematoxylin-eosin staining); and bladders were scanned by MRI for visualization and localization of the iron-labelled donor cells. Donor fibroblast cell colonization and cellular viability at the VUJ was demonstrated by MRI and histochemically indicating cellular uptake of iron particles at the VUJ. It was also evident that transplanted fibroblasts integrate into the extracellular matrix of the distal ureter augmenting ureteral host tissue. Labelled implanted autologous fibroblasts were visualized by staining procedure as well as MRI scan demonstrating persistence at the VUJ, suggesting that in vitro expanded fibroblasts survived in vivo after transplantation.

Transplantation of mesenchymal stem cells and fibroblasts in a bio‐compatible matrix corrects defective dermal remodeling

Curative molecular therapies are needed to correct matrix dysfunctions that results in scar formation upon healing. Mesenchymal stem cell transplantation has been reported to enhance healing however the mechanism for this response is unknown. The possibilities include the restorative paracrine effects of MSC synthesized soluble factors on dermal cells and matrix expression. This study examines the influence MSC's have on matrix remodeling in vivo. We recently developed a chronic wound scar model based on the absence of wound resolution through CXCR3 signaling axis; these mice develop sterile chronic inflammation and hypertrophic scars. Using fibroblasts encapsulated with MSC's in a biocompatible matrix, we determined that fibroblasts could overcome endogenous deficiencies and generate a more physiological dermal tissue. Xenotransplantation of CXCR3−/− mouse fibroblast and hMSC's into wounds of CXCR3−/− mouse scarring model revealed an increase in survival and reduced apoptosis, enhanced healing response, correction of matrix regeneration, and reduced inflammation during the first 30 days. Changes in matrix and soluble signals were also examined. These data suggest in situ matrix composition and mature matrix generation regulates scarring. This study provides insight into conceptual therapies of cell transplantation, by altering soluble factors, as viable for antifibrotic treatment.

Morphofunctional Evaluation of the Effect of Transplantation of Allogeneic Fibroblasts on Healing of Burn Wounds in Albino Outbred Mice and Mutant Hr hr /Hr hr Mice

Morphofunctional evaluation of the effect of transplantation of allogeneic fibroblasts on skin regeneration after burn injury in albino outbred mice and mutant Hr(hr)/Hr(hr) (nude) mice was carried out using the radioautographic method. The pronounced stimulating effect of allogeneic fibroblasts on healing of burn wound observed in mice of both groups can be attributed to the action of bioactive substances released from destructed allogeneic fibroblasts and stimulating proliferation of stem/progenitor cells in the wound (epithelial cells in skin appendages and dermal cells in microvessel walls) at the early stages of healing.

Human dental pulp-derived stem cells promote locomotor recovery after complete transection of the rat spinal cord by multiple neuro-regenerative mechanisms

Spinal cord injury (SCI) often leads to persistent functional deficits due to loss of neurons and glia and to limited axonal regeneration after injury. Here we report that transplantation of human dental pulp stem cells into the completely transected adult rat spinal cord resulted in marked recovery of hind limb locomotor functions. Transplantation of human bone marrow stromal cells or skin-derived fibroblasts led to substantially less recovery of locomotor function. The human dental pulp stem cells exhibited three major neuroregenerative activities. First, they inhibited the SCI-induced apoptosis of neurons, astrocytes, and oligodendrocytes, which improved the preservation of neuronal filaments and myelin sheaths. Second, they promoted the regeneration of transected axons by directly inhibiting multiple axon growth inhibitors, including chondroitin sulfate proteoglycan and myelin-associated glycoprotein, via paracrine mechanisms. Last, they replaced lost cells by differentiating into mature oligodendrocytes under the extreme conditions of SCI. Our data demonstrate that tooth-derived stem cells may provide therapeutic benefits for treating SCI through both cell-autonomous and paracrine neuroregenerative activities.

Creation of myocardial fibrosis by transplantation of fibroblasts primed with survival factors

One of the major obstacles in the creation of myocardial fibrosis using fibroblasts is massive cell death after cell injection. To overcome this problem, a method that delivers fibroblasts primed with survival factors was studied. Cardiac fibroblasts were isolated from wild-type male C57BL/6 mice. Female mice were randomly placed into the following three groups: 1) fibroblasts transfected with β-galactosidase-containing adenovirus (control group), 2) fibroblasts treated with a necrosis inhibitor (NI group), and 3) fibroblasts transfected with Akt-containing adenovirus (Akt group). Pretreated cells were transplanted into the recipient heart by direct injection after a thoracotomy. Quantitative real-time PCR and morphometric analysis were performed to investigate the effects of survival factor priming on the induction of cell engraftment and fibrosis. In addition, a canine model was used to investigate the development of fibrosis and conduction modification using autologous dermal fibroblasts. The NI and Akt groups showed a better engraftment rate: 13 (NI group) and 7 (Akt group) times greater at 21 days compared with the control group. Increased fibrosis and conduction delay were also observed in the NI and Akt groups compared with the control group. Survival factor priming increased cellular engraftment and enhanced the efficacy of cell transplantation. Delivery of fibroblasts primed with survival factors might be a promising approach to develop conduction modification as a novel strategy to treat arrhythmias.