Curcumin inhibits the formation of capillary-like tubes by rat lymphatic endothelial cells

The natural pigments curcumin and berberine have been shown to exhibit a variety of pharmacologic effects including anti-inflammatory, anti-cancer, and anti-metastatic properties. Here, we investigated the anti-lymphangiogenic effect with an in vitro tube-forming model using conditionally immortalized lymphatic endothelial TR-LE cells, a newly established cell line originating from the thoracic duct of a transgenic rat expressing the temperature-sensitive SV40 large T-antigen. Curcumin, but not berberine, exhibited a dose-dependent inhibition of the formation of capillary-like tubes by TR-LE cells without affecting cell viability and adhesion to Matrigel. To address the molecular mechanisms involved, we performed experiments with specific inhibitors against putative targets of curcumin, including IkappaB kinase (IKK), epidermal growth factor receptor (EGFR), phosphatidylinositol-3 kinase (PI3K)/Akt, and matrix metalloproteinases (MMPs). While the IKK-2 inhibitor VI and EGFR tyrosine kinase inhibitors gefitinib and PD153035 had no effect, both the PI3K inhibitor LY294002 and the MMP inhibitor GM6001 shortened the tubes by approximately 50%. Western blot analysis and gelatin zymography revealed that curcumin, but not berberine, has an inhibitory effect on the phosphorylation of Akt and enzymatic activity of MMP-2 in TR-LE cells. These results suggest that curcumin exerts its inhibitory effect on lymphangiogenesis partly through Akt and MMP-2.     

Attenuation of nitric oxide- and prostaglandin-independent vasodilation of retinal arterioles induced by acetylcholine in streptozotocin-treated rats

Diabetes alters retinal hemodynamics, but little is known about the impact of diabetes on the role of endothelium-derived hyperpolarizing factor (EDHF) in the regulation of retinal circulation. Therefore, we examined how diabetes affects the nitric oxide- and prostaglandin-independent vasodilation of retinal arterioles induced by acetylcholine. Male Wistar rats were treated with streptozotocin (80 mg/kg, i.p.) and experiments were performed 6-8 weeks later. Under artificial ventilation, rats were treated with tetrodotoxin (100 microg/kg, i.v.) to eliminate any nerve activity and prevent movement of the eye. Methoxamine was used to maintain adequate systemic circulation. Fundus images were captured by a digital camera that was equipped with a special objective lens. The vasodilator responses of retinal arterioles were assessed by measuring changes in diameters of the vessels. In streptozotocin-induced diabetic rats and the age-matched controls, acetylcholine increased diameters of retinal arterioles in a dose-dependent manner. The vasodilator responses to acetylcholine in diabetic rats were smaller than those in control rats. The nitric oxide- and prostaglandin-independent vasodilation of retinal arterioles observed under treatment with combination of N(G)-nitro-l-arginine methyl ester (30 mg/kg, i.v.) and indomethacin (5 mg/kg, i.v.) were also attenuated by diabetes. Diabetes did not alter the dilator responses of retinal arterioles to sodium nitroprusside and forskolin. These results suggest that diabetes impairs EDHF-mediated vasodilation of retinal arterioles induced by acetylcholine. The impaired EDHF-mediated vasodilation may contribute to alteration of retinal hemodynamics in diabetes.     

High prevalence of gastroesophageal reflux disease with minimal mucosal change in asthmatic patients

It is known that the prevalence of gastroesophageal reflux disease (GERD) in asthmatic patients is high. Although an endoscopic diagnosis of GERD based on the established Los Angeles (LA) classification requires the detection of erosive mucosal breaks, there are patients with GERD who have prominent erythema of the esophageal membrane without erosive mucosal breaks. Non-erosive mucosal change denotes the minimal change of the discoloring type of reflux esophagitis. This study was undertaken to determine the prevalence of GERD in asthmatic patients using the LA classification with the inclusion of minimal change, compared to the prevalence determined using the established LA classification without minimal change. The presence of GERD in asthmatic patients (n = 78), non-asthmatic disease control patients (n = 56), and healthy subjects (n = 150) was evaluated by endoscopic examination. The frequency of GERD in asthmatic patients based on the LA classification with minimal change was higher (54/78, 69.2%) than in asthmatic patients based on the LA classification without minimal change (37/78, 47.4%) (p < 0.05). The prevalence of GERD in asthmatic patients (69.2%) was higher than that in disease control patients (17/56, 30.4%) and healthy subjects (27/150, 18.0%) based on the LA classification with minimum change. These data indicate that asthmatic patients have a high frequency of GERD. In addition, without the inclusion of minimum change to the diagnosis of GERD, the prevalence of GERD appears to be underestimated in asthmatic patients. Therefore, physicians should carefully observe asthmatic patients with minimal change on endoscopy.     

Novel fish hypothalamic neuropeptides stimulate the release of gonadotrophins and growth hormone from the pituitary of sockeye salmon

We recently identified a cDNA encoding three novel fish hypothalamic neuropeptides, having LPXRF-NH(2) from the goldfish brain. In this study, to clarify the physiological functions of these three LPXRFamide peptides (gfLPXRFa-1, -2, and -3), we analysed the localisation and hypophysiotrophic activity of these peptides using sockeye salmon, Oncorhynchus nerka, in which immunoassay systems for several anterior pituitary hormones have been developed. gfLPXRFa-immunoreactive cell bodies were detected in the nucleus posterioris periventricularis of the hypothalamus and immunoreactive fibres were distributed in various brain regions and the pituitary. We also detected gfLPXRFa-immunoreactivity in the pituitary by competitive enzyme-linked immunosorbent assay combined with reversed-phase HPLC. These three gfLPXRFamide peptides stimulated the release of FSH, LH and GH, but did not affect the release of prolactin (PRL) and somatolactin (SL) from cultured pituitary cells. These results suggest that novel fish hypothalamic LPXR-Famide peptides exist in the brain and pituitary of sockeye salmon and stimulate the release of gonadotrophins and GH from the pituitary.     

Brain SPECT analysis by 3D-SSP and phenotype of Parkinson's disease

OBJECTIVES: We hypothesize that the regional pattern of blood flow reduction in the brain is different between tremor-dominant Parkinson's disease (PD) and postural instability gait difficulty (PIGD)-dominant PD. We therefore investigated the association of phenotypes in untreated PD with brain perfusion on SPECT using three-dimensional stereotactic surface projection (3D-SSP) technique. PATIENTS AND METHODS: Thirty-three patients who had PD without dementia (12 men and 21 women with a mean age of 67.1+/-6.4 years) were included in this study. Their symptoms were rated using the Unified Parkinson's Disease Rating Scale (UPDRS). Patients were grouped in two phenotypes: tremor and PIGD-dominant groups based on UPDRS components. Around the same time, all patients were examined by N-isopropyl-p[123I] iodoamphetamine single photon emission computed tomography (123I-IMP SPECT), and obtained images were analyzed with 3D-SSP using an image-analysis software, NEUROSTAT. Data on brain surface perfusion extracted by 3D-SSP analysis were compared between the PD patients and the normal control group. The same comparisons were made for subgroups of PD patients. RESULTS: Cerebral perfusion was decreased at the anterior cingulate cortex and primary visual cortex of the PD patients, and especially by the pixel-by-pixel comparison, perfusion was significantly decreased at the right anterior cingulate cortex compared with the normal controls. In the PIGD-dominant group, more severe hypoperfusion was seen at the same regions. In the tremor-dominant group, significant hypoperfusion was not seen compared with the normal controls. CONCLUSIONS: The regional pattern of blood flow reduction in the brain was found to be different between tremor-dominant PD and PIGD-dominant PD. These regional differences were considered to suggest different and disease-specific combinations of underlying pathophysiological and neurochemical processes.