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 x 10(6) 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.

BACKGROUND & AIMS Capillarization, characterized by loss of differentiation of liver sinusoidal endothelial cell (LSEC), precedes the onset of hepatic fibrosis. We investigated whether restoring differentiation to LSEC in liver affects their interactions with hepatic stellate cells (HSCs) and thereby promotes quiescence of HSCs and regression of fibrosis. METHODS Rat LSECs were cultured with inhibitors and/or agonists and examined by scanning electron microscopy for fenestrae in sieve plates. Cirrhosis was induced in rats using thioacetamide, followed by administration of BAY 60-2770, an activator of soluble guanylate cyclase (sGC). Fibrosis was assessed by Sirius red staining; expression of α-smooth muscle actin was measured by immunoblot analysis. RESULTS Maintenance of LSEC differentiation requires vascular endothelial growth factor-A stimulation of nitric oxide (NO)-dependent signaling (via sGC and cGMP) and NO-independent signaling. In rats with thioacetamide-induced cirrhosis, BAY 60-2770 accelerated the complete reversal of capillarization (restored differentiation of LSEC) without directly affecting activation of HSC or fibrosis. Restoration of differentiation to LSEC led to quiescence of HSC and regression of fibrosis, in the absence of further exposure to BAY 60-2770. Activation of sGC with BAY 60-2770, prevented progression of cirrhosis, despite continued administration of thioacetamide. CONCLUSIONS Differentiation of LSEC has an important role in activation of HSC and the fibrotic process in rats.

Summary Accumulating evidence suggests that co-deletion of tumor suppressor genes Pten and p53 plays a crucial role in the development of castration-resistant prostate cancer in vivo. However, the molecular mechanism underlying Pten/p53-deficiency driven prostate tumorigenesis remains incompletely understood. Building upon insights gained from our studies with Pten/p53-deficient mouse embryonic fibroblasts (MEFs), we report here that hexokinase 2 (HK2) is selectively upregulated by the combined loss of Pten and p53 in prostate cancer cells. Mechanistically, Pten deletion increases HK2 mRNA translation through activation of the AKT-mTORC1-4EBP1 axis and p53 loss enhances HK2 mRNA stability through inhibition of miR143 biogenesis. Genetic studies demonstrate that HK2-mediated aerobic glycolysis, known as the Warburg effect, is required for Pten/p53-deficiency driven tumor growth in xenograft mouse models of prostate cancer. Our findings suggest that HK2 might be a therapeutic target for prostate cancer patients carrying Pten and p53 mutations.