Effects of stem cell factor on in vitro growth of buffalo oocytes.

Stem cell factor (SCF) plays important roles in primordial follicle activation, oocyte growth and survival, granulosa cell proliferation, theca cell recruitment, and ovarian steroidogenesis. The aim of this study was to investigate the effect of SCF on in vitro growth of buffalo oocytes. Oocyte-granulosa cell complexes (OGCs) were dissected from early antral follicles of slaughtered buffalo ovaries and cultured for 6 days in media supplemented with 0, 50 or 100 ng/mL SCF. In vitro grown oocytes were further cultured for in vitro maturation for 24 h. The results showed that SCF significantly (P < 0.05) increased oocyte diameter in vitro. The percentages of surviving oocytes were 60, 81 and 92 in 0, 50 and 100 ng/mL SCF supplemented group, respectively. SCF promoted formation of antrum-like structures in culture. The results also showed that SCF enhanced the maturation of in vitro grown buffalo oocytes. Here, 14% in vitro grown oocytes reached metaphase II (MII) stage in 50 ng/mL SCF supplemented group, whereas the percentage was increased to 26% in 100 ng/mL SCF treated group. These results show that SCF supports the growth, viability and nuclear maturation of buffalo oocytes in vitro.

Stem cell factor and granulocyte colony-stimulating factor promote brain repair and improve cognitive function through VEGF-A in a mouse model of CADASIL.

Cerebral autosomal dominant arteriopathy with subcortical infarct and leukoencephalopathy (CADASIL) is a cerebral small vascular disease caused by NOTCH3 gene mutation in vascular smooth muscle cells (VSMCs), leading to ischemic stroke and vascular dementia. To date, the pathogenesis of CADASIL remains poorly understood, and there is no treatment that can slow the progression of CADASIL. Using a transgenic mouse model of CADASIL (TgNotch3R90C), this study reveals novel findings for understanding CADASIL pathogenesis that decreased cerebral vascular endothelial growth factor (VEGF/VEGF-A) is linked to reduced cerebral blood vessel density. Reduced endothelial cell (EC) proliferation and angiogenesis are seen in TgNotch3R90C mouse brain-isolated ECs. Decreased dendrites, axons, and synapses in the somatosensory and motor cortex layer 2/3 and in the hippocampal CA1, and reduced neurogenesis in both the subventricular zone and subgranular zone occur in 15-month-old TgNotch3R90C mice. These reductions in neuron structures, synapses, and neurogenesis are significantly correlated to decreased cerebral vasculature in the corresponding areas. Impaired spatial learning and memory in TgNotch3R90C mice are significantly correlated with the reduced cerebral vasculature, neuron structures, and synapses. Repeated treatment of stem cell factor and granulocyte colony-stimulating factor (SCF+G-CSF) at 9 and 10 months of age improves cognitive function, increases cerebral VEGF/VEGF-A, restores cerebral vasculature, and enhances regeneration of neuronal structures, synaptogenesis and neurogenesis in TgNotch3R90C mice. Pretreatment with Avastin, an angiogenesis inhibitor by neutralizing VEGF-A, completely eliminates the SCF+G-CSF-enhanced cognitive function, vascular and neuronal structure regeneration, synaptogenesis and neurogenesis in TgNotch3R90C mice. SCF+G-CSF-enhanced EC proliferation and angiogenesis in TgNotch3R90C mouse brain-isolated ECs are also blocked by Avastin pretreatment. These data suggest that SCF+G-CSF treatment may repair Notch3R90C mutation-damaged brain through the VEGF-A-mediated angiogenesis. This study provides novel insight into the involvement of VEGF/VEGF-A in the pathogenesis of CADASIL and sheds light on the mechanism underlying the SCF+G-CSF-enhanced brain repair in CADASIL.

Study of stem cell homing & self-renewal marker gene profile of ex vivo expanded human CD34+ cells manipulated with a mixture of cytokines & stromal cell-derived factor 1.

BACKGROUND & OBJECTIVES: Next generation transplantation medicine aims to develop stimulating cocktail for increased ex vivo expansion of primitive hematopoietic stem and progenitor cells (HSPC). The present study was done to evaluate the cocktail GF (Thrombopoietin + Stem Cell factor + Flt3-ligand) and homing-defining molecule Stromal cell-derived factor 1 (SDF1) for HSPC ex vivo expansion. METHODS: Peripheral blood stem cell (n=74) harvests were analysed for CD34hiCD45lo HSPC. Immunomagnetically enriched HSPC were cultured for eight days and assessed for increase in HSPC, colony forming potential in vitro and in vivo engrafting potential by analyzing human CD45+ cells. Expression profile of genes for homing and stemness were studied using microarray analysis. Expression of adhesion/homing markers were validated by flow cytometry/ confocal microscopy. RESULTS: CD34hiCD45lo HSPC expansion cultures with GF+SDF1 demonstrated increased nucleated cells (n=28, P+ cells (n=8, P=0.021) and increased colony forming units (cfu) compared to unstimulated and GF-stimulated HSPC. NOD-SCID mice transplanted with GF+SDF1-HSPC exhibited successful homing/engraftment (n=24, PInterpretation & conclusions: Cocktail of cytokines and SDF1 showed good potential to successfully expand HSPC which exhibited enhanced ability to generate multilineage cells in short-term and long-term repopulation assay. This cocktail-mediated stem cell expansion has potential to obviate the need for longer and large volume apheresis procedure making it convenient for donors.

Role of stem cell factor in the regulation of ICC proliferation and detrusor contraction in rats with an underactive bladder.

Stem cell factor (SCF) is critical in regulating the proliferation, differentiation and function of the interstitial cells of Cajal (ICCs), which are closely associated with smooth muscle dysfunction. The present study aimed to examine the effect of SCF on ICC proliferation and detrusor contraction in rats with an underactive bladder. Sprague­Dawley rats were divided into four groups comprising control, control+SCF, detrusor underactivity (DU), and DU+SCF groups. The ICC count was determined using immunofluorescence; serum levels of SCF were determined using an enzyme­linked immunosorbent assay; mRNA and protein levels of c­kit and SCF in tissues were assessed using reverse transcription­quantitative polymerase chain reaction and western blot analyses, respectively. Detrusor contractility was determined using muscle strips, based on the contraction amplitude and frequency determined in each specimen. Significantly fewer ICCs were observed in the DU group, in addition to decreased expression levels of SCF and c­kit, compared with the control group. In addition, the detrusor contraction frequency and amplitude were markedly reduced. However, the administration of SCF significantly increased the number of ICCs, and the levels of SCF and c­kit in animals with DU, and resulted in markedly amplified detrusor contraction frequency and amplitude. Similarly, the number of ICCs and levels of SCF and c­kit were higher in the control+SCF group, compared with the control group. Overall, these findings suggested that exogenous SCF improved the organ dysfunction caused by reduced ICC number, providing a novel approach for organ repair.

Stem cell factor promotes in vitro ovarian follicle development in the domestic cat by upregulating c-kit mRNA expression and stimulating the phosphatidylinositol 3-kinase/AKT pathway.

In the present study we examined the effects of stem cell factor (SCF; 50 vs 100ngmL-1) alone or in combination with epidermal growth factor (EGF; 100ngmL-1) on: (1) the in vitro viability and growth of cat follicles within ovarian cortices; (2) phosphatidylinositol 3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MAPK) phosphorylation; and (3) c-kit and FSH receptor (FSHr) mRNA expression. At 100ngmL-1, SCF increased (P≤0.05) the percentage and size of secondary follicles after 14 days of in vitro culture and sustained AKT phosphorylation after 3 days incubation. EGF suppressed this beneficial effect and reduced (P≤0.05) the percentage of structurally normal follicles and FSHr expression when combined with 100ngmL-1 SCF. Expression of c-kit mRNA was higher (P≤0.05) in the presence of 100ngmL-1 SCF compared with fresh follicles and cohorts cultured under other conditions. A c-kit inhibitor suppressed follicle growth and reduced AKT phosphorylation. Collectively, the results demonstrate that SCF promotes cat follicle development by upregulating c-kit mRNA expression and AKT phosphorylation. EGF suppresses the stimulating effect of SCF, leading to downregulation of FSHr expression.

Cytokine therapy-mediated neuroprotection in a Friedreich's ataxia mouse model.

OBJECTIVES: Friedreich's ataxia is a devastating neurological disease currently lacking any proven treatment. We studied the neuroprotective effects of the cytokines, granulocyte-colony stimulating factor (G-CSF) and stem cell factor (SCF) in a humanized murine model of Friedreich's ataxia. METHODS: Mice received monthly subcutaneous infusions of cytokines while also being assessed at monthly time points using an extensive range of behavioral motor performance tests. After 6 months of treatment, neurophysiological evaluation of both sensory and motor nerve conduction was performed. Subsequently, mice were sacrificed for messenger RNA, protein, and histological analysis of the dorsal root ganglia, spinal cord, and cerebellum. RESULTS: Cytokine administration resulted in significant reversal of biochemical, neuropathological, neurophysiological, and behavioural deficits associated with Friedreich's ataxia. Both G-CSF and SCF had pronounced effects on frataxin levels (the primary molecular defect in the pathogenesis of the disease) and a regulators of frataxin expression. Sustained improvements in motor coordination and locomotor activity were observed, even after onset of neurological symptoms. Treatment also restored the duration of sensory nerve compound potentials. Improvements in peripheral nerve conduction positively correlated with cytokine-induced increases in frataxin expression, providing a link between increases in frataxin and neurophysiological function. Abrogation of disease-related pathology was also evident, with reductions in inflammation/gliosis and increased neural stem cell numbers in areas of tissue injury. INTERPRETATION: These experiments show that cytokines already clinically used in other conditions offer the prospect of a novel, rapidly translatable, disease-modifying, and neuroprotective treatment for Friedreich's ataxia. Ann Neurol 2017;81:212-226.

In vivo correction of anaemia in ß-thalassemic mice by γPNA-mediated gene editing with nanoparticle delivery.

The blood disorder, ß-thalassaemia, is considered an attractive target for gene correction. Site-specific triplex formation has been shown to induce DNA repair and thereby catalyse genome editing. Here we report that triplex-forming peptide nucleic acids (PNAs) substituted at the γ position plus stimulation of the stem cell factor (SCF)/c-Kit pathway yielded high levels of gene editing in haematopoietic stem cells (HSCs) in a mouse model of human ß-thalassaemia. Injection of thalassemic mice with SCF plus nanoparticles containing γPNAs and donor DNAs ameliorated the disease phenotype, with sustained elevation of blood haemoglobin levels into the normal range, reduced reticulocytosis, reversal of splenomegaly and up to 7% ß-globin gene correction in HSCs, with extremely low off-target effects. The combination of nanoparticle delivery, next generation γPNAs and SCF treatment may offer a minimally invasive treatment for genetic disorders of the blood that can be achieved safely and simply by intravenous administration.

Delayed application of the haematopoietic growth factors G-CSF/SCF and FL reduces neonatal excitotoxic brain injury.

BACKGROUND: Developmental brain injury results in cognitive and motor deficits in the preterm infant. Enhanced glutamate release and subsequent receptor activation are major pathogenetic factors. The effect of haematopoietic growth factors, such as granulocyte colony-stimulating factor (G-CSF), stem cell factor (SCF) and flt-3 ligand (FL) on neonatal brain injury is controversially discussed. Timing of treatment is known to be a crucial factor. Based on the hypothesis that an exacerbation of injury is caused by administration of substances in the acute phase, the objective of this study was to evaluate the effect of delayed administration of G-CSF/SCF and FL to protect against excitotoxic brain injury in vivo. METHODS: In an established neonatal mouse model of excitotoxic brain injury, we evaluated the effect of daily intraperitoneal doses of G-CSF/SCF or FL, starting 60 h after the excitotoxic insult. RESULTS: Intraperitoneal injections of G-CSF/SCF and FL, given 60 h after the excitotoxic insult, significantly reduced lesion size at postnatal days 10, 18 and 90. G-CSF/SCF treatment resulted in a decrease in apoptotic cell death indicated by reduced caspase-3 activation. G-CSF/SCF and FL treatment did not affect apoptosis-inducing factor-dependent apoptosis or cell proliferation. CONCLUSION: We show that delayed systemic treatment with the haematopoietic growth factors G-CSF/SCF and FL protects against N-methyl-D-aspartate receptor-mediated developmental excitotoxic brain damage. Our results suggest that neuroprotective effects in this neonatal animal model of excitotoxic brain injury depend on the timing of drug administration after the insult.

Granulocyte-colony stimulating factor in combination with stem cell factor confers greater neuroprotection after hypoxic-ischemic brain damage in the neonatal rats than a solitary treatment.

Neonatal hypoxia-ischemia (HI) is a devastating condition resulting in neuronal cell death and often culminates in neurological deficits. Granulocyte-colony stimulating factor (G-CSF) has been shown to have neuroprotective activity via inhibition of apoptosis and inflammation in various stroke models. Stem cell factor (SCF) regulates hematopoietic stem cells in the bone marrow and has been reported to have neuroprotective properties in an experimental ischemic stroke model. In this study we aim to determine the protective effects of G-CSF in combination with SCF treatment after experimental HI. Seven-day old Sprague-Dawley rats were subjected to unilateral carotid artery ligation followed by 2.5 hours of hypoxia. Animals were randomly assigned to five groups: Sham (n=8), Vehicle (n=8), HI with G-CSF treatment (n=9), HI with SCF treatment (n=9) and HI with G-CSF+SCF treatment (coadministration group; n=10). G-CSF (50 µg/kg), SCF (50 µg/kg) and G-CSF+SCF (50 µg/kg) were administered intraperitoneally 1 hour post HI followed by daily injection for 4 consecutive days (five total injections). Animals were euthanized 14 days after HI for neurological testing. Additionally assessment of brain, heart, liver, spleen and kidney atrophy was performed. Both G-CSF and G-CSF+SCF treatments improved body growth and decreased brain atrophy at 14 days post HI. No significant differences were found in the peripheral organ weights between groups. Finally, the G-CSF+SCF coadministration group showed significant improvement in neurological function. Our data suggest that administration of G-CSF in combination with SCF not only prevented brain atrophy but also significantly improved neurological function.

The role of stem cell factor and granulocyte-colony stimulating factor in treatment of stroke.

Stroke is a serious cerebrovascular disease that causes high mortality and persistent disability in adults worldwide. Stroke is also an enormous public health problem and a heavy public financial burden in the United States. Treatment for stroke is very limited. Thrombolytic therapy by tissue plasminogen activator (tPA) is the only approved treatment for acute stroke, and no effective treatment is available for chronic stroke. Developing new therapeutic strategies, therefore, is a critical need for stroke treatment. This article summarizes the discovery of new routes of treatment for acute and chronic stroke using two hematopoietic growth factors, stem cell factor (SCF) and granulocyte-colony stimulating factor (G-CSF). In a study of acute stroke, SCF and G-CSF alone or in combination displays neuroprotective effects in an animal model of stroke. SCF appears to be the optimal treatment for acute stroke as the functional outcome is superior to G-CSF alone or in combination (SCF+G-CSF); however, SCF+G-CSF does show better functional recovery than G-CSF. In a chronic stroke study, the therapeutic effects of SCF and G-CSF alone or in combination appear differently as compared with their effects on the acute stroke. SCF+G-CSF induces stable and long-lasting functional improvement; SCF alone also improves functional outcome but its effectiveness is less than SCF+G-CSF, whereas G-CSF shows no therapeutic effects. Although the mechanism by which SCF+G-CSF repairs the brain in chronic stroke remains poorly understood, our recent findings suggest that the SCF+G-CSF-induced functional improvement in chronic stroke is associated with a contribution to increasing angiogenesis and neurogenesis through bone marrow-derived cells and the direct effects on stimulating neurons to form new neuronal networks. These findings would assist in developing new treatment for stroke. The article presents some promising patents on role of stem cell factor and granulocyte-colony stimulating factor in treatment of stroke.

A degradable, bioactive, gelatinized alginate hydrogel to improve stem cell/growth factor delivery and facilitate healing after myocardial infarction.

Despite remarkable effectiveness of reperfusion and drug therapies to reduce morbidity and mortality following myocardial infarction (MI), many patients have debilitating symptoms and impaired left ventricular (LV) function highlighting the need for improved post-MI therapies. A promising concept currently under investigation is intramyocardial injection of high-water content, polymeric biomaterial gels (e.g., hydrogels) to modulate myocardial scar formation and LV adverse remodeling. We propose a degradable, bioactive hydrogel that forms a unique microstructure of continuous, parallel capillary-like channels (Capgel). We hypothesize that the innovative architecture and composition of Capgel can serve as a platform for endogenous cell recruitment and drug/cell delivery, therefore facilitating myocardial repair after MI.

Revisiting emergency anti-apoptotic cytokinotherapy: erythropoietin synergizes with stem cell factor, FLT-3 ligand, trombopoietin and interleukin-3 to rescue lethally-irradiated mice.

We have re-evaluated the benefit of using erythropoietin (Epo) as a pleiotropic cytokine to counteract hematological and extra-hematological toxicity following lethal irradiation. B6D2F1 mice were exposed to a dose of 9 Gy gamma radiation resulting in 90% mortality at 30 days, and then injected with stem cell factor, FLT-3 ligand, thrombopoietin and interleukin-3 [i.e. SFT3] at two and 24 hours with or without Epo (1,000 IU/kg) at 2 hours and day 8. As controls, two groups of irradiated mice were given only Epo or Phosphate-buffered saline. Epo synergized with SFT3 to rescue lethally-irradiated mice from radiation-induced death (survival: 60%, 95% and 5% respectively for SFT3, SFT3+Epo and controls at 30 days, p<0.05), whereas Epo alone exhibited no protective effect. Hematopoietic parameters did not differ significantly between SFT3 and SFT3+Epo groups during the animal death period. Some beneficial effects on gastro-intestinal toxicity were noticed following administration of Epo, although lung, liver and kidney were not protected. Further studies are necessary to understand fully the mechanisms involved in these effects of Epo in order to optimize treatment with cytokines following high-dose irradiation.

Prevention of chemotherapy-induced anemia and thrombocytopenia by constant administration of stem cell factor.

PURPOSE: Chemotherapy-induced apoptosis of immature hematopoietic cells is a major cause of anemia and thrombocytopenia in cancer patients. Although hematopoietic growth factors such as erythropoietin and colony-stimulating factors cannot prevent the occurrence of drug-induced myelosuppression, stem cell factor (SCF) has been previously shown to protect immature erythroid and megakaryocytic cells in vitro from drug-induced apoptosis. However, the effect of SCF in vivo as a single myeloprotective agent has never been elucidated. EXPERIMENTAL DESIGN: The ability of SCF to prevent the occurrence of chemotherapy-induced anemia and thrombocytopenia was tested in a mouse model of cisplatin-induced myelosuppression. To highlight the importance of maintaining a continuous antiapoptotic signal in immature hematopoietic cells, we compared two treatment schedules: in the first schedule, SCF administration was interrupted during chemotherapy treatment and resumed thereafter, whereas in the second schedule, SCF was administered without interruption for 7 days, including the day of chemotherapy treatment. RESULTS: The administration of SCF to cisplatin-treated mice could preserve bone marrow integrity, inhibit apoptosis of erythroid and megakaryocytic precursors, prevent chemotherapy-induced anemia, and rapidly restore normal platelet production. Treatment with SCF increased the frequency of Bcl-2/Bcl-XL-positive bone marrow erythroid cells and sustained Akt activation in megakaryocytes. Myeloprotection was observed only when SCF was administered concomitantly with cisplatin and kept constantly present during the days following chemotherapy treatment. CONCLUSIONS: SCF treatment can prevent the occurrence of chemotherapy-induced anemia and thrombocytopenia in mice, indicating a potential use of this cytokine in the supportive therapy of cancer patients.

Combined effects of interleukin-7 and stem cell factor administration on lymphopoiesis after murine bone marrow transplantation.

The decreased ability of the thymus to generate T cells after bone marrow transplantation (BMT) is a clinically significant problem. Interleukin (IL)-7 and stem cell factor (SCF) induce proliferation, differentiation, and survival of thymocytes. Although previous studies have shown that administration of recombinant human IL-7 (rhIL-7) after murine and human BMT improves thymopoiesis and immune function, whether administration of SCF exerts similar effects is unclear. To evaluate independent or combinatorial effects of IL-7 and SCF in post-BMT thymopoiesis, bone marrow (BM)-derived mesenchymal stem cells transduced ex vivo with the rhIL-7 or murine SCF (mSCF) genes were cotransplanted with T cell-depleted BM cells into lethally irradiated mice. Although rhIL-7 and mSCF each improved immune reconstitution, the combination treatment had a significantly greater effect than either cytokine alone. Moreover, the combination treatment significantly increased donor-derived common lymphoid progenitors (CLPs) in BM, suggesting that transplanted CLPs expand more rapidly in response to IL-7 and SCF and may promote immune reconstitution. Our findings demonstrate that IL-7 and SCF might be therapeutically useful for enhancing de novo T cell development. Furthermore, combination therapy may allow the administration of lower doses of IL-7, thereby decreasing the likelihood of IL-7-mediated expansion of mature T cells.

Stem cell mobilization and collection for induction of mixed chimerism and renal allograft tolerance in cynomolgus monkeys.

BACKGROUND: We have previously observed that donor bone marrow hematopoietic stem cells successfully induce transient mixed chimerism and renal allograft tolerance following non-myeloablative conditioning of the recipient. Stem cells isolated from the peripheral blood (PBSC) may provide similar benefits. We sought to determine the most effective method of mobilizing PBSC for this approach and the effects of differing conditioning regimens on their engraftment. METHODS: A standard dose (10 µg/kg) or high dose (100 µg/kg) of granulocyte colony-stimulating factor (GCSF) with or without stem cell factor (SCF) was administered to the donor, and PBSC were collected by leukapheresis. Cynomolgus monkey recipients underwent a nonmyeloablative conditioning regimen (total body irradiation, thymic irradiation, and ATG) with splenectomy (splenectomy group) or a short course of anti-CD154 antibody (aCD154) (aCD154 group). Recipients then received combined kidney and PBSC transplantation and a 1-mo post-transplant course of cyclosporine. RESULTS: Treatments with either two cytokines (GCSF+SCF) or high dose GCSF provided significantly more hematopoietic progenitor cells than standard dose GCSF alone. Recipients in the aCD154 group developed significantly higher myeloid and lymphoid chimerism (P < 0.0001 and P = 0.0002, respectively) than those in the splenectomy group. Longer term renal allograft survival without immunosuppression was also observed in the aCD154 group, while two of three recipients in the splenectomy group rejected their allografts soon after discontinuation of immunosuppression. CONCLUSIONS: Protocols including administration of two cytokines (GCSF + SCF) or high dose GCSF alone significantly mobilized more PBSC than standard dose GCSF alone. The recipients of PBSC consistently developed excellent chimerism and survived long-term without immunosuppression, when treated with CD154 blockade.

Efficacy of the coadministration of granulocyte colony-stimulating factor and stem cell factor in the activation of intrinsic cells after spinal cord injury in mice.

OBJECT: Granulocyte colony-stimulating factor (G-CSF) is a hematopoietic cytokine that induces undifferentiated stem cells from the bone marrow (BM) into the peripheral blood. Stem cell factor (SCF) is also a hematopoietic cytokine that stimulates the differentiation and proliferation of neural stem cells and has neuroprotective effects. In cerebrally infarcted mice, the combination of G-CSF and SCF promotes the differentiation of BM-derived cells into neural cells, stimulates the proliferation of intrinsic neural stem cells, and improves motor function. The object of this study was to investigate the effects of these cytokines on BM stem cells, intrinsic cells, and motor function recovery in spinal cord-injured mice. METHODS: For marking BM-derived cells, the authors induced contusive spinal cord injury in mice transplanted with BM cells from green fluorescent protein (GFP)-transgenic mice after whole-body irradiation. These mice were treated with G-CSF and SCF in the subacute injury phase. Bromodeoxyuridine (BrdU) was injected into these mice to label proliferating cells. The cell numbers and phenotype of the BM-derived cells were evaluated, and the change in intrinsic cells (proliferation, accumulation, and differentiation) was noted using immunohistological analysis at 4 weeks postinjury (wpi). A behavior analysis was conducted until 12 wpi using the Basso, Beattie, Bresnahan locomotor rating scale. RESULTS: In the SCF + G-CSF group, improvement in hindlimb motor function was significantly greater than in the SCF group, G-CSF group, and sham-treatment (vehicle) group after 8 wpi. At 4 wpi, the number of GFP+ BM-derived cells induced in the lesion did not significantly differ between groups. At 4 wpi, the authors evaluated perilesional GFP− intrinsic spinal cord cells. The number of GFP− and F4/80+ cells was significantly greater in the SCF + G-CSF group than in the other 3 groups. As compared with the sham group, the number of NG2+/BrdU+ cells was significantly increased in the SCF + G-CSF group. CONCLUSIONS: In this study, the combined administration of SCF and G-CSF in traumatic spinal cord injury not only improved motor function, but also induced the accumulation of intrinsic microglia and the active proliferation of intrinsic oligodendrocyte precursor cells.

Pimecrolimus induces apoptosis of mast cells in a murine model of cutaneous mastocytosis.

BACKGROUND: Cutaneous mastocytosis (CM) is a common type of mastocytosis. Current treatment of CM is generally symptomatic. Pimecrolimus has been demonstrated as an effective anti-inflammatory drug for the treatment of inflammatory skin diseases, but whether it treats CM remains unknown. METHODS: The murine model of CM was induced by subcutaneous injection of 100 µg/kg recombinant murine stem cell factor (rmSCF) for a total of 17 days in Balb/c mice. Beginning on the 8th day, treatment with pimecrolimus 1% cream or vehicle was performed topically and daily for 10 days. The clinical signs of CM were scored, and pathological analysis was performed with toluidine blue staining and hematoxylin and eosin staining. The in situ apoptotic mast cells (MCs) were studied by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. The cutaneous histamine level was measured by ELISA. RESULTS: In the rmSCF-treated mice, the clinical signs of CM, including erythema, wheal after rubbing lesion skins, and increased thickness of skin, were obvious compared to control mice, and were reduced after pimecrolimus treatment. The numbers of cutaneous MCs and neutrophils were significantly greater in mice with CM than in control mice, and pimecrolimus treatment decreased the numbers of MCs but not neutrophils. Extensive apoptosis of cutaneous MCs was observed in pimecrolimus-treated mice. The cutaneous histamine level was elevated in the mice with CM compared with healthy controls, and was lowered after treatment with pimecrolimus. CONCLUSIONS: Pimecrolimus effectively treats CM by reducing the density of cutaneous MCs and the subsequent histamine production through inducing MCs apoptosis.

Embryonic stem cells as a model for studying melanocyte development.

Melanocytes are neural crest-derived pigment-producing cells that reside in the inner ear, in the uveal tract, in hair follicles, and in the skin. The main function of melanocytes is to provide pigmentation through melanin production and secretion to the immediate surrounding area. Although much is known about mature melanocyte function and regulation, particularly in the skin, little is known with regard to the signals and gene expression patterns that ensue upon melanocyte development and differentiation from embryonic precursors. The ability to examine these patterns in an in vitro specified setting through the use of embryonic stem cells holds great potential for understanding melanocyte biology. In this chapter, we outline our procedures for the differentiation of human embryonic stem cells toward mature pigment-producing melanocytes that express the appropriate melanocytic markers and home to the epidermal basal layer in 3D skin reconstructs.

Stem cell factor prevents neuronal cell apoptosis after acute spinal cord injury.

STUDY DESIGN: A rat spinal cord injury (SCI) model and immunohistochemistry were used to examine the levels of expression of stem cell factor and c-kit. In addition, we examined whether intraperitoneal administration of stem cell factor could prevent neural cells apoptosis after acute SCI. OBJECTIVE: To evaluate the antiapoptotic effect of stem cell factor after SCI. SUMMARY OF BACKGROUND DATA: It is well known that the mode of delayed neuronal and glial cell death after SCI is apoptosis. Inhibition of apoptosis might thus promote neurologic improvement after SCI. Stem cell factor and its receptor c-kit exhibit pleiotropic effects in early hematopoiesis, and are also known to prevent hematopoietic progenitor cell apoptosis. Stem cell factor has recently been reported to be a survival factor for neural stem cells in vitro. We examined the levels of expression of stem cell factor and c-kit in normal and injured rat spinal cord. In addition, we examined whether stem cell factor prevents neural cell apoptosis after acute SCI. METHODS: We examined the expression of stem cell factor and c-kit in spinal cord after injury by quantitative RT-PCR and immunohistochemistry. Antiapoptotic effects of stem cell factor were examined using rats with SCI that received stem cell factor intraperitoneally, and were examined immunohistochemically with anticleaved PARP antibody and antiactive caspase-3 antibody between 1 and 3 days after injury. RESULTS: Upregulation of stem cell factor and c-kit expression occured after SCI. We also found that neurons express stem cell factor, and neurons and oligodendrocytes express c-kit after SCI. In addition, intraperitoneal administration of stem cell factor prevented spinal neural cells apoptosis after injury. CONCLUSION: These findings suggest the possibility that stem cell factor, a hematopoietic cytokine, could be useful as an agent for treatment of SCI.