The effect of G-CSF in a myocardial ischemia reperfusion model rat

Granulocyte Colony-Stimulating Factor Prevents Ischemia/Reperfusion-Induced Ovarian Injury in Rats: Evaluation of Histological and Biochemical Parameters

Granulocyte colony-stimulating factor (G-CSF) is a glycoprotein commonly used in the field of medicine to treat neutropenia. Granulocyte colony-stimulating factor has also crucial roles in ameliorating the ischemia/reperfusion (I/R) injury in particular tissues. In this study, we aimed to investigate the protective effect of G-CSF on ovarian damage in experimental ovarian I/R injury. Thirty adult female rats were used. Rats were separated randomly into 5 groups; Group 1: sham group (abdominal wall was opened and closed surgically), Group 2: torsion group with 3-hour ischemia using vascular clips. Group 3: torsion + G-CSF group with 3-hour ischemia 30 minutes after the administration intraperitoneal (i.p.) of 100 µg/kg of G-CSF. Group 4: torsion-detorsion group with 3 hour ischemia and 3 hour reperfusion. Group 5: torsion-detorsion + G-CSF group with 3 hour ischemia followed by 100 µg/kg of G-CSF i.p. administration 30 minutes prior to 3 hour of detorsion/reperfusion. Ovarian tissue damage was scored on histopathology. Ovarian tissue malondialdehyde (MDA) was measured biochemically. In comparison with the sham group, both the torsion and torsion-detorsion groups had significantly higher scores for follicular degeneration, vascular congestion, edema, hemorrhage, and leukocyte infiltration (P < .05). When compared group torsion-detorsion + G-CSF to group torsion-detorsion, parameters aforementioned significantly decreased in group torsion-detorsion + G-CSF (P < .05). Granulocyte colony-stimulating factor has also decreased MDA levels notably both in the torsion + G-CSF and torsion-detorsion + G-CSF groups (P < .05, P < .01). Our experimental study suggests that G-CSF can be a novel agent for the treatment of ovarian I/R injury.

Generation and characterization of transgenic mouse mesenchymal stem cell lines expressing hIGF-1 or hG-CSF

Mesenchymal stem cells (MSC) are promising tools in the fields of cell therapy and regenerative medicine. In addition to their differentiation potential, MSC have the ability to secrete bioactive molecules that stimulate tissue regeneration. Thus, the overexpression of cytokines and growth factors may enhance the therapeutic effects of MSC. Here we generated and characterized mouse bone marrow MSC lines overexpressing hG-CSF or hIGF-1. MSC lines overexpressing hG-CSF or hIGF-1 were generated through lentiviral vector mediated gene transfer. The expression of hG-CSF or hIGF-1 genes in the clones produced was quantified by qRT-PCR, and the proteins were detected in the cell supernatants by ELISA. The cell lines displayed cell surface markers and differentiation potential into adipocytes, osteocytes and chondrocytes similar to the control MSC cell lines, indicating the conservation of their phenotype even after genetic modification. IGF-1 and G-CSF transgenic cells maintained immunosuppressive activity. Finally, we performed a comparative gene expression analysis by qRT-PCR array in the cell lines expressing hIGF-1 and hG-CSF when compared to the control cells. Our results demonstrate that the cell lines generated may be useful tools for cell therapy and are suitable for testing in disease models.

Pretreatment of Adipose Derived Stem Cells with Curcumin Facilitates Myocardial Recovery via Antiapoptosis and Angiogenesis

The poor survival rate of transplanted stem cells in ischemic myocardium has limited their therapeutic efficacy. Curcumin has potent antioxidant property. This study investigates whether prior curcumin treatment protects stem cells from oxidative stress injury and improves myocardial recovery following cells transplantation. Autologous Sprague-Dawley rat adipose derived mesenchymal stem cells (ADSCs) were pretreated with or without curcumin. The hydrogen peroxide/serum deprivation (H2O2/SD) medium was used to mimic the ischemic condition in vitro. Cytoprotective effects of curcumin on ADSCs were evaluated. Curcumin pretreatment significantly increased cell viability and VEGF secretion, and decreased cell injury and apoptosis via regulation of PTEN/Akt/p53 and HO-1 signal proteins expression. The therapeutic potential of ADSCs implantation was investigated in myocardial ischemia-reperfusion injury (IRI) model. Transplantation of curcumin pretreated ADSCs not only resulted in better heart function, higher cells retention, and smaller infarct size, but also decreased myocardial apoptosis, promoted neovascularization, and increased VEGF level in ischemic myocardium. Together, priming of ADSCs with curcumin improved tolerance to oxidative stress injury and resulted in enhancement of their therapeutic potential of ADSCs for myocardial repair. Curcumin pretreatment is a promising adjuvant strategy for stem cells transplantation in myocardial restoration.

Granulocyte colony-stimulating factor with or without stem cell factor extends time to premature ovarian insufficiency in female mice treated with alkylating chemotherapy

OBJECTIVE

To examine gonadal protective properties of granulocyte colony-stimulating factor (G-CSF) alone or in combination with stem cell factor (SCF) in female mice treated with high-dose alkylating chemotherapy.

DESIGN

Experimental laboratory animal study.

SETTING

Tertiary care academic hospital and research institute.

ANIMAL(S)

Six- and 8-week-old C57Bl/6 female mice.

INTERVENTION(S)

Adult female mice were treated with [1] cyclophosphamide and busulfan (CTx), [2] CTx + G-CSF/SCF, [3] CTx + G-CSF, or [4] normal saline and dimethyl sulfoxide (DMSO; vehicle control).

MAIN OUTCOME MEASURE(S)

Follicle counts, microvessel density, cellular response to DNA damage, and litter production.

RESULT(S)

G-CSF ± SCF increased microvessel density and decreased follicle loss in CTx-treated female mice compared with CTx-only treated female mice. Mice administered CTx alone exhibited premature ovarian insufficiency, with only 28% of mice producing two litters. However, 100% of mice receiving CTx with G-CSF + SCF, and 80% of mice receiving CTx + G-CSF alone produced at least three litters and 20% of mice in each group produced five litters.

CONCLUSION(S)

Treatment of mice with G-CSF decreases chemotherapy-induced ovarian follicle loss and extends time to premature ovarian insufficiency in female mice. Further studies are needed to validate these preclinical results in humans and compare efficacy with the established GnRH analogue treatments.

Ischemia/reperfusion injury promotes and granulocyte-colony stimulating factor inhibits migration of bone marrow-derived stem cells to endometrium

The endometrium is a dynamic tissue that undergoes repeated rounds of regeneration in each reproductive (estrous or menstrual) cycle. We have previously shown that bone marrow (BM)-derived stem cells engraft the endometrium in rodents and humans; however, it is not known if these cells contribute physiologically to uterine cyclic regeneration or alternatively are primarily involved in uterine repair in response to injury. Here we performed male-to-female BM transplant and tested the ability of uterine injury to recruit BM-derived cells to endometrium in the presence and absence of sex steroids. Uterine ischemia/reperfusion injury resulted in an ~2-fold increase in BM-derived stem cell recruitment to the endometrium. The effect was independent of sex steroids or the existence of an estrous cycle. BM-derived mesenchymal stem cells (MSCs) are involved in uterine repair after injury, but not the cyclic regeneration of the endometrium in the estrous/menstrual cycle. Granulocyte-colony stimulating factor (G-CSF) is used to increase BM mobilization for transplant and has been proposed as a means of mobilizing stem cells to the uterus. Here G-CSF treatment led to decreased BM engraftment of the uterus after injury, likely by favoring mobilization of hematopoietic stem cells over the MSCs. G-CSF is unlikely to be of benefit in repair of uterine injury in humans. Taken together, we demonstrate that ischemic injury drives BM MSC engraftment of the uterus, independent of estrous cycle, sex steroids, or G-CSF.

Hematopoietic cytokines for cardiac repair: mobilization of bone marrow cells and beyond

Hematopoietic cytokines, traditionally known to influence cellular proliferation, differentiation, maturation, and lineage commitment in the bone marrow, include granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor, stem cell factor, Flt-3 ligand, and erythropoietin among others. Emerging evidence suggests that these cytokines also exert multifarious biological effects on diverse nonhematopoietic organs and tissues. Although the precise mechanisms remain unclear, numerous studies in animal models of myocardial infarction (MI) and heart failure indicate that hematopoietic cytokines confer potent cardiovascular benefits, possibly through mobilization and subsequent homing of bone marrow-derived cells into the infarcted heart with consequent induction of myocardial repair involving multifarious mechanisms. In addition, these cytokines are also known to exert direct cytoprotective effects. However, results from small-scale clinical trials of G-CSF therapy as a single agent after acute MI have been discordant and largely disappointing. It is likely that cardiac repair following cytokine therapy depends on a number of known and unknown variables, and further experimental and clinical studies are certainly warranted to accurately determine the true therapeutic potential of such therapy. In this review, we discuss the biological features of several key hematopoietic cytokines and present the basic and clinical evidence pertaining to cardiac repair with hematopoietic cytokine therapy.

JAK redux: a second look at the regulation and role of JAKs in the heart

A number of type 1 receptor cytokine family members protect the heart from acute and chronic oxidative stress. This protection involves activation of two intracellular signaling cascades: the reperfusion injury salvage kinase (RISK) pathway, which entails activation of phosphatidylinositol 3-kinase (PI3-kinase) and ERK1/2, and JAK-STAT signaling, which involves activation of transcription factor signal transducer and activator of transcription 3 (STAT3). Obligatory for activation of both RISK and STAT3 by nearly all of these cytokines are the kinases JAK1 and JAK2. Yet surprisingly little is known about how JAK1 and JAK2 are regulated in the heart or how they couple to PI3-kinase activation. Although the JAKs are linked to antioxidative stress programs in the heart, we recently reported that these kinases are inhibited by oxidative stress in cardiac myocytes. In contrast, others have reported that cardiac JAK2 is activated by acute oxidative stress by an undefined process. Here we summarize recent insights into the regulation of JAK1 and JAK2. Besides oxidative stress, inhibitory regulation involves phosphorylation, nitration, and intramolecular restraints. Stimulatory regulation involves phosphorylation and adaptor proteins. The net effect of stress on JAK activity in the heart likely represents the sum of both inhibitory and stimulatory processes, along with their dynamic interaction. Thus the regulation of JAKs in the heart, once touted as the paragon of simplicity, is proving rather complicated indeed, requiring a second look. It is our contention that a better understanding of the regulation of this kinase family that is implicated in cardiac protection could translate into effective therapeutic strategies for preventing myocardial damage or repairing the injured heart.

G-CSF therapy with mobilization of bone marrow stem cells for myocardial recovery after acute myocardial infarction--a relevant treatment?

This review of adjunctive therapy with subcutaneous granulocyte-colony stimulating factor (G-CSF) to patients with acute myocardial infarction (AMI) focus on the cardioprotective effects and potential mechanisms of G-CSF and discuss the therapeutic potential of G-CSF. All clinical trials published in peer-reviewed journals identified through PubMed are discussed. G-CSF treatment seems to be safe, and initial unblinded trials in patients with AMI were encouraging. However, larger double-blind placebo-controlled trials have not been able to demonstrate improved myocardial recovery after G-CSF treatment. Current controversies in interpretation of the results include 1) importance of direct cardiac effect of G-CSF vs indirect through bone marrow stem and progenitor cell mobilization, 2) importance of timing of G-CSF therapy, 3) importance of G-CSF dose, and 4) importance of cell types mobilized from the bone-marrow. Cell-based therapies to improve cardiac function remain promising and further experimental and clinical studies are warranted to determine the future role of G-CSF.