Jieli Chen

Therapeutic Benefit of Intravenous Administration of Bone Marrow Stromal Cells After Cerebral Ischemia in Rats

Background and Purpose— We tested the hypothesis that intravenous infusion of bone marrow derived-marrow stromal cells (MSCs) enter the brain and reduce neurological functional deficits after stroke in rats. Methods— Rats (n=32) were subjected to 2 hours of middle cerebral artery occlusion (MCAO). Test groups consisted of MCAO alone (group 1, n=6); intravenous infusion of 1×106 MSCs at 24 hours after MCAO (group 2, n=6); or infusion of 3×106 MSCs (group 3, n=7). Rats in groups 1 to 3 were euthanized at 14 days after MCAO. Group 4 consisted of MCAO alone (n=6) and group 5, intravenous infusion of 3×106 MSCs at 7 days after MCAO (n=7). Rats in groups 4 and 5 were euthanized at 35 days after MCAO. For cellular identification, MSCs were prelabeled with bromodeoxyuridine. Behavioral tests (rotarod, adhesive-removal, and modified Neurological Severity Score [NSS]) were performed before and at 1, 7, 14, 21, 28, and 35 days after MCAO. Immunohistochemistry was used to identify MSCs or cells derived from MSCs in brain and other organs. Results— Significant recovery of somatosensory behavior and Neurological Severity Score (P <0.05) were found in animals infused with 3×106 MSCs at 1 day or 7 days compared with control animals. MSCs survive and are localized to the ipsilateral ischemic hemisphere, and a few cells express protein marker phenotypic neural cells. Conclusions— MSCs delivered to ischemic brain tissue through an intravenous route provide therapeutic benefit after stroke. MSCs may provide a powerful autoplastic therapy for stroke.

Human marrow stromal cell therapy for stroke in rat: Neurotrophins and functional recovery

ObjectiveTo test the effect of IV-injected human bone marrow stromal cells (hMSC) on neurologic functional deficits after stroke in rats. Methods Rats were subjected to transient middle cerebral artery occlusion and IV injected with 3 × 106 hMSC 1 day after stroke. Functional outcome was measured before and 1, 7, and 14 days after stroke. Mixed lymphocyte reaction and the development of cytotoxic T lymphocytes measured the immune rejection of hMSC. A monoclonal antibody specific to human cellular nuclei (mAb1281) was used to identify hMSC and to measure neural phenotype. ELISA analyzed neurotrophin levels in cerebral tissue from hMSC-treated or nontreated rats. Bromodeoxyuridine injections were used to identify newly formed cells. Results Significant recovery of function was found in rats treated with hMSC at 14 days compared with control rats with ischemia. Few (1 to 5%) hMSC expressed proteins phenotypic of brain parenchymal cells. Brain-derived neurotrophic factor and nerve growth factor significantly increased, and apoptotic cells significantly decreased in the ischemic boundary zone; significantly more bromodeoxyuridine-reactive cells were detected in the subventricular zone of the ischemic hemisphere of rats treated with hMSC. hMSC induced proliferation of lymphocytes without the induction of cytotoxic T lymphocytes. ConclusionNeurologic benefit resulting from hMSC treatment of stroke in rats may derive from the increase of growth factors in the ischemic tissue, the reduction of apoptosis in the penumbral zone of the lesion, and the proliferation of endogenous cells in the subventricular zone.

Intravenous Administration of Human Bone Marrow Stromal Cells Induces Angiogenesis in the Ischemic Boundary Zone After Stroke in Rats

Abstract— We tested the hypothesis that intravenous infusion of human bone marrow stromal cells (hMSCs) promotes vascular endothelial growth factor (VEGF) secretion, VEGF receptor 2 (VEGFR2) expression and angiogenesis in the ischemic boundary zone (IBZ) after stroke. hMSCs (1×106) were intravenously injected into rats 24 hours after middle cerebral artery occlusion (MCAo). Laser scanning confocal microscopy (LSCM), immunohistochemistry and ELISA were performed to assay angiogenesis and levels of human and rat VEGF in the host brain, respectively. In addition, capillary-like tube formation was measured using mouse brain-derived endothelial cells (MBDECs). Morphological and three dimensional image analyses revealed significant (P <0.05) increases in numbers of enlarged and thin walled blood vessels and numbers of newly formed capillaries at the boundary of the ischemic lesion in rats (n=12) treated with hMSCs compared with numbers in rats (n=12) treated with PBS. ELISA measurements showed that treatment with hMSCs significantly (P <0.05) raised endogenous rat VEGF levels in the IBZ from 10.5±1.7 ng/mL in the control group to 17.5±1.6 ng/mL in the hMSC-treated group. In addition, treatment with hMSCs increased endogenous VEGFR2 immunoreactivity. In vitro, when MBDECs were incubated with the supernatant obtained from cultured hMSCs, capillary-like tube formation was significantly (P <0.01) induced. However, hMSC-induced capillary-like tube formation was significantly (P <0.01) inhibited when the endothelial cells were incubated with the supernatant from hMSCs in the presence of a neutralizing anti-VEGFR2. These data suggest that treatment of stroke with hMSCs enhances angiogenesis in the host brain and hMSC-enhanced angiogenesis is mediated by increases in levels of endogenous rat VEGF and VEGFR2.

Spinal cord injury in rat: treatment with bone marrow stromal cell transplantation.

We tested the hypothesis that transplantation of bone marrow stromal cells (MSCs) into the spinal cord after a contusion injury promotes functional outcome. Rats (n = 31) were subjected to a weight driven implant injury. MSCs or phosphate buffered saline was injected into the spinal cord I week after injury. Sections of tissue were analyzed by double-labeled immunohistochemistry for MSC identification. Functional outcome measurements using the Basso-Beattie-Bresnehan score were performed weekly to 5 weeks post-injury. The data indicate significant improvement in functional outcome in animals treated with MSC transplantation compared to control animals. Scattered cells derived from MSCs expressed neural protein markers. These data suggest that transplantation of MSCs may have a therapeutic role after spinal cord injury.

Intravenous bone marrow stromal cell therapy reduces apoptosis and promotes endogenous cell proliferation after stroke in female rat

The present study investigates the induction of neurogenesis, reduction of apoptosis, and promotion of basic fibroblast growth factor (bFGF) expression as possible mechanisms by which treatment of stroke with bone marrow stromal cells (MSCs) improves neurological functional recovery. Additionally, for the first time, we treated cerebral ischemia in female rats with intraveneous administration of MSCs. Female rats were subjected to 2 hr of middle cerebral artery occlusion (MCAo), followed by an injection of 3 × 106 male (for Y chromosome labeling) rat MSCs or phosphate‐buffered saline (PBS) into the tail vein 24 hr after MCAo. All animals received daily injection of bromodeoxyuridine (BrdU; 50 mg/kg, i.p.) for 13 days after treatment for identification of newly synthesized DNA. Animals were sacrificed at 14 days after MCAo. Behavioral tests (rotarod and adhesive‐removal tests) were performed. In situ hybridization, immunohistochemistry, and terminal deoxynucleotidyltransferase (TdT)‐mediated dUTP‐biotin nick‐end labeling (TUNEL) were performed to identify transplanted MSCs (Y chromosome), BrdU, bFGF, and apoptotic cells in the brain. Significant recovery of behavior was found in MSC‐treated rats at 7 days in the somatosensory test and at 14 days in the motor test after MCAo compared with control, PBS‐treated animals (P < .05). MSCs were found to survive and preferentially localize to the ipsilateral ischemic hemisphere. Significantly more BrdU‐positive cells were located in the subventricular zone (P < .05), and significantly fewer apoptotic cells and more bFGF immunoreactive cell were found in the ischemic boundary area (P < .05) of MSC‐treated rats than in PBS‐treated animals. Here we demonstrate that intravenously administered male MSCs increase bFGF expression, reduce apoptosis, promote endogenous cellular proliferation, and improve functional recovery after stroke in female rats.

Therapeutic benefit of intracerebral transplantation of bone marrow stromal cells after cerebral ischemia in rats

We tested the hypothesis that bone marrow stromal cells (MSCs) transplanted into the ischemic boundary zone, survive, differentiate and improve functional recovery after middle cerebral artery occlusion (MCAo). MSCs were harvested from adult rats and cultured with or without nerve growth factor (NGF). For cellular identification, MSCs were prelabeled with bromodeoxyuridine (BrdU). Rats (n=24) were subjected to 2 h of MCAo, received grafts at 24 h and were euthanized at 14 days after MCAo. Test groups consisted of: (1) control-MCAo alone (n=8); (2) intracerebral transplantation of MSCs (n=8); (3) intracerebral transplantation of MSCs cultured with NGF (n=8). Immunohistochemistry was used to identify cells from MSCs. Behavioral tests (rotarod, adhesive-removal and modified neurological severity score [NSS]) were performed before and after MCAo. The data demonstrate that MSCs survive, migrate and differentiate into phenotypic neural cells. Significant recovery of somatosensory behavior (p<0.05) and NSS (p<0.05) were found in animals transplanted with MSCs compared with control animals. Animals that received MSCs cultured with NGF displayed significant recovery in motor (p<0.05), somatosensory (p<0.05) and NSS (p<0.05) behavioral tests compared with control animals. Our data suggest that intracerebral transplantation of MSCs may provide a powerful autoplastic therapy for stroke.

Statins induce angiogenesis, neurogenesis, and synaptogenesis after stroke

We demonstrate that the 3‐hydroxy‐3‐methyl‐glutaryl‐coenzyme A (HMG‐CoA) reductase inhibitors atorvastatin and simvastatin enhance functional outcome and induce brain plasticity when administered after stroke to rats. With atorvastatin treatment initiated 1 day after stroke, animals exhibited significant increases in vascular endothelial growth factor, cyclic guanosine monophosphate, angiogenesis, endogenous cell proliferation and neurogenesis, and an increase in the synaptic protein, synaptophysin. Atorvastatin‐induced angiogenesis in a tube formation assay was reduced by an antibody against the vascular endothelial growth factor receptor 2 (FIK‐1) and by the nitric oxide synthase inhibitor, N‐mono‐methyl‐L‐arginine (L‐NAME). Atorvastatin also induced phosphorylation of Akt and Erk in cultured primary cortical neurons. These data indicate that atorvastatin induced brain plasticity and has neurorestorative activity after experimental stroke. Ann Neurol 2003

Intrastriatal Transplantation of Bone Marrow Nonhematopoietic Cells Improves Functional Recovery After Stroke in Adult Mice

The authors transplanted adult bone marrow nonhematopoietic cells into the striatum after embolic middle cerebral artery occlusion (MCAO). Mice (n = 23; C57BL/6J) were divided into four groups: (1) mice (n = 5) were subjected to MCAO and transplanted with bone marrow nonhematopoietic cells (prelabeled by bromodeoxyuridine, BrdU) into the ischemic striatum, (2) MCAO alone (n = 8), (3) MCAO with injection of phosphate buffered saline (n = 5), and (4) bone marrow nonhematopoietic cells injected into the normal striatum (n = 5). Mice were killed at 28 days after stroke. BrdU reactive cells survived and migrated a distance of approximately 2.2 mm from the grafting areas toward the ischemic areas. BrdU reactive cells expressed the neuronal specific protein NeuN in 1% of BrdU stained cells and the astrocytic specific protein glial fibrillary acidic protein (GFAP) in 8% of the BrdU stained cells. Functional recovery from a rotarod test (P < 0.05) and modified neurologic severity score tests (including motor, sensory, and reflex;P < 0.05) were significantly improved in the mice receiving bone marrow nonhematopoietic cells compared with MCAO alone. The current findings suggest that the intrastriatal transplanted bone marrow nonhematopoietic cells survived in the ischemic brain and improved functional recovery of adult mice even though infarct volumes did not change significantly. Bone marrow nonhematopoietic cells may provide a new avenue to promote recovery of injured brain.

Treatment of stroke in rat with intracarotid administration of marrow stromal cells.

Objective: To measure the therapeutic efficacy for the treatment of stroke with intra-arterial administration of bone marrow stromal cells (MSC). Background: MSC have characteristics of stem and progenitor cells. The hypothesis that MSC injected into the internal carotid artery after stroke enter into ischemic brain and improve neurologic recovery was tested. Methods: Twenty-five adult Wistar rats were subjected to transient (2-hour) middle cerebral artery occlusion alone (n = 9), or treated with intracarotid arterial injection of 200 μL phosphate-buffered saline (n = 8) or 2 × 106 MSC in 200 μL phosphate-buffered saline (n = 8) 1 day after ischemia. MSC were harvested and isolated from additional adult rats and then cultured and labeled with bromodeoxyuridine. Rats were subjected to neurologic functional tests (adhesive-removal, modified neurologic severity scores) before and at 1, 7, and 14 days after middle cerebral artery occlusion. Immunohistochemistry was used to identify cell-specific proteins of bromodeoxyuridine-reactive MSC. Results: Bromodeoxyuridine-reactive cells (∼21% of 2 × 106 injected MSC) distributed throughout the territory of the middle cerebral artery by 14 days after ischemia. Some bromodeoxyuridine-reactive cells expressed proteins characteristic of astrocytes and neurons. Rats with intra-arterial transplantation of MSC exhibited improvement on the adhesive-removal test (p < 0.05) and the modified neurologic severity scores (p < 0.05) at 14 days compared with controls. Conclusions: MSC injected intra-arterially are localized and directed to the territory of the middle cerebral artery, and these cells foster functional improvement after cerebral ischemia.

Ischemic rat brain extracts induce human marrow stromal cell growth factor production.

Intravenous administration of human bone marrow stromal cells (hMSCs) after middle cerebral artery occlusion (MCAo) in rats provides functional benefit. We tested the hypothesis that these functional benefits are derived in part from hMSC production of growth and trophic factors. Quantitative sandwich enzyme‐linked immunosorbent assay (ELISA) of hMSCs cultured with normal and MCAo brain extracts were performed. hMSCs cultured in supernatant derived from ischemic brain extracts increased production of brain‐derived neurotrophic factor (BDNF), nerve growth factor (NGF), vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF). These neurotrophins and angiogenic growth factors increased in a post‐ischemia time‐dependent manner. The hMSC capacity to increase expression of growth and trophic factors may be the key to the benefit provided by transplanted hMSCs in the ischemic brain.