Aescin protection of human vascular endothelial cells exposed to cobalt chloride mimicked hypoxia and inflammatory stimuli

Human vascular endothelial cells (HUVECs) were exposed to CoCl2 as an in vitro model of hypoxia. Expression of VCAM-1 (vascular cell adhesion molecule), reduction of PECAM-1 (platelet endothelial cell adhesion molecule) and cytoskeletal changes without alterations in cell viability were observed. HUVECs were also exposed to Escherichia coli lipopolysaccaride (LPS) as an in vitro model of inflammation: significant IL-6 release was measured. Pre-treatment of HUVECs with aescin prevented, in a concentration-dependent fashion (0.1-1 microM), the action of CoCl2 on VCAM-1 and PECAM-1, also preserving endothelial cell morphology. Furthermore, aescin pre-treatment reduced IL-6 release from LPS-activated vascular endothelium

GLUCOCORTICOIDS DEPRESS ACTIVITY-DEPENDENT EXPRESSION OF BDNF MESSENGER-RNA IN HIPPOCAMPAL-NEURONS

Glucocorticoid hormones are important regulators of brain development and ageing, and can impair the capacity of hippocampal neurones to survive various neurological insults. Here we show that dexamethasone, a synthetic glucocorticoid, prevents activity-dependent increases of brain-derived neurotrophic factor (BDNF) mRNA in cultures of rat hippocampal neurones. In situ hybridization was used to evaluate the levels of BDNF mRNA. Up-regulation of BDNF mRNA triggered by depolarization with high potassium, or exposure to the glutamate receptor agonist kainic acid, resulted both from higher levels of expression in neurones and from new recruitment of cells. These data suggest that the known ability of glucocorticoids to exacerbate neuronal injury following ischaemia and other metabolic insults could be due to antagonism of regulatory mechanisms governing neurotrophin levels in the brain

TIME-COURSE, LOCALIZATION AND PHARMACOLOGICAL MODULATION OF IMMEDIATE-EARLY INDUCIBLE GENES, BRAIN-DERIVED NEUROTROPHIC FACTOR AND TRKB MESSENGER-RNAS IN THE RAT-BRAIN FOLLOWING PHOTOCHEMICAL STROKE

A focal, unilateral thrombotic stroke was produced in the rat sensorimotor cortex. The time course of expression and localization of the immediate early inducible genes: c-fos, c-jun, zif268; nerve growth factor, brain-derived neurotrophic factor and the related tyrosine kinase high-affinity receptor (trkB) messenger RNAs were studied by in situ hybridization. The levels of messenger RNAs for c-fos, zif268, brain-derived neurotrophic factor (but not nerve growth factor) and trkB were consistently increased in cortex ipsilaterally to the lesion, while c-jun messenger RNA content was only slightly increased. The brain-derived neurotrophic factor messenger RNA was increased from 2 to 18 h following the stroke, mainly in cells having a normal morphological appearance. The trkB messenger RNA displayed temporal and spatial increases similar to brain-derived neurotrophic factor messenger RNA. The time course and pattern of expression of immediate early inducible gene and trophic factor messenger RNAs did not clearly support a causal relationship between these two families of factors. The observed messenger RNA increases were greatly attenuated by the non-competitive N-methyl-D-aspartate-sensitive glutamate receptor antagonist (+)-5-methyl-10,11-dihydroxy-5H-dibenzo(a,d)cyclohepten-5,10-imine , but substantially unaffected by the non-N-methyl-D-aspartate receptor antagonist 2,3-dihydroxy-6-nitrosulphanoylbenzoquinoxaline. The results suggest a major contribution of N-methyl-D-aspartate-sensitive glutamate receptor activation to the transcriptionally directed events subsequent to stroke. Future studies should clarify the contribution of these processes to either the progression of neuronal degeneration or the establishment of protective compensatory responses

ERbeta expression in normal, adenomatous and carcinomatous tissues of patients with familial adenomatous polyposis

Objectives. The APC gene mutation triggers familial adenomatous polyposis (FAP) and approximately 80% of sporadic colorectal cancers. FAP summarizes the natural history of colorectal cancer because low-and high-grade dysplastic lesions and adenocarcinoma are simultaneously present in the same patients free from individual and environmental variability factors. Estrogen receptor beta (ER beta) has recently been suggested as the most likely mediator of estrogen-related anti-carcinogenic effects in Apc(Min-/+) mice and humans. In this study we assessed the ER beta expression in the intestinal mucosa of FAP patients to verify its possible involvement in tumor progression in colorectal cancer. Material and methods. ER beta and ER alpha expression, cell proliferation (Ki-67) and apoptosis (TUNEL), were evaluated on archival biopsy material from six patients with FAP who underwent colectomy. Results. A progressive significant decrease of ER beta expression was observed in the different stages of the disease as compared to normal mucosa (p < 0.001). Interestingly, a decreased ER beta expression was directly correlated with apoptosis (r = 0.76, p < 0.001), and inversely correlated with cell proliferation (r = 0.54, p < 0.05). Conclusions. ER beta expression is related to the severity of the disease, supporting the role of ER beta as a relevant biomarker of tumor progression and possible chemopreventive target in patients at risk of colonic neoplasia

PHOTOCHEMICAL STROKE AND BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) MESSENGER-RNA EXPRESSION

In situ hybridization and Northern blotting were used to study the expression of brain-derived neurotrophic factor (BDNF) mRNA in the rat brain following photochemical stroke. A focal thrombotic lesion of the sensorimotor cortex was produced by intravenously injecting the light-sensitive dye rose bengal and exposing the skull to a controlled beam of light. Four hours after the light exposure the level of BDNF mRNA was increased in the hippocampus and cortex ipsilateral and perifocal to the lesion. The stroke-induced BDNF mRNA increase was prevented by the non-competitive glutamate receptor blocker dizocilpine (MK-801). The results indicate that the activation of N-methyl-D-aspartate (NMDA)-sensitive glutamate receptors is involved in the stroke-triggered stimulation of BDNF mRNA increase