Differential proteomic analysis of human glioblastoma and neural stem cells reveals HDGF as a novel angiogenic secreted factor

Presence in glioblastomas of cancer cells with normal neural stem cell (NSC) properties, tumor initiating capacity, and resistance to current therapies suggests that glioblastoma stem-like cells (GSCs) play central roles in glioblastoma development. We cultured human GSCs endowed with all features of tumor stem cells, including tumor initiation after xenograft and radio-chemoresistance. We established proteomes from four GSC cultures and their corresponding whole tumor tissues (TTs) and from human NSCs. Two-dimensional difference gel electrophoresis and tandem mass spectrometry revealed a twofold increase of hepatoma-derived growth factor (HDGF) in GSCs as compared to TTs and NSCs. Western blot analysis confirmed HDGF overexpression in GSCs as well as its presence in GSC-conditioned medium, while, in contrast, no HDGF was detected in NSC secretome. At the functional level, GSC-conditioned medium induced migration of human cerebral endothelial cells that can be blocked by anti-HDGF antibodies. In vivo, GSC-conditioned medium induced neoangiogenesis, whereas HDGF-targeting siRNAs abrogated this effect. Altogether, our results identify a novel candidate, by which GSCs can support neoangiogenesis, a high-grade glioma hallmark. Our strategy illustrates the usefulness of comparative proteomic analysis to decipher molecular pathways, which underlie GSC properties.     

Reconstitution of ATP-dependent aminophospholipid translocation in proteoliposomes.

In addition to ion-pumping ATPases, most plasma membranes of animal cells contain a Mg2+ ATPase activity, the function of which is unknown. This enzyme, of apparent molecular mass 110 kDa, was purified from human erythrocyte membranes by a series of column chromatographic procedures after solubilization in Triton X-100. When reincorporated into artificial bilayers formed from phosphatidylcholine, it was able to transport a spin-labeled phosphatidylserine analogue from the inner to the outer membrane leaflet provided Mg2+ ATP was present in the incubation mixture. The ATP-dependent transport of the phosphatidylethanolamine analogue required the presence of an anionic phospholipid (e.g., phosphatidylinositol) in the outer membrane leaflet. In contrast the transmembrane distribution of spin-labeled phosphatidylcholine was unaffected in the same experimental conditions. This transmembrane movement of aminophospholipid analogues was inhibited by treatment of the proteoliposomes with a sulfhydryl reagent. We conclude that the Mg2+ ATPase is sufficient for the biochemical expression of the aminophospholipid translocase activity, which is responsible for the inward transport of phosphatidylserine and phosphatidylethanolamine within the erythrocyte membrane. The presence of this transport activity in many animal cell plasma membranes provides a function for the Mg2+ ATPase borne by these membranes.     

Pancreatic exocrine responses to secretin, 2-deoxyglucose, a meal, and ethanol after coeliac ganglionectomy in the conscious dog.

The effects of coeliac ganglionectomy on pancreatic exocrine responses to graded doses of secretin, intravenous 2-deoxyglucose 100 mg/kg, ethanol 0.56 g/kg, and 1 g/kg, and to a meat meal were studied in conscious dogs (weight 11 to 27 kg). Five animals underwent coeliac ganglionectomy and up to seven control animals were studied. Coeliac ganglionectomy increased four-fold the pancreatic fluid response to secretin. The early part of the fluid response to 2-deoxyglucose was reduced, but there was no effect on the protein response to 2-deoxyglucose. In controls, ethanol 0.56 g/kg stimulated pancreatic secretion, to nearly double the basal level, but after coeliac ganglionectomy this dose of ethanol inhibited secretion to one third of basal values. There was no effect of coeliac ganglionectomy on pancreatic response to ethanol 1 g/kg. After coeliac ganglionectomy the early response to a meal was increased by 100% for fluid output and by 50% for protein secretion, but from 10 minutes to two hours after the meal there was no effect on pancreatic response. These data shed further light on the mode of action of ethanol on pancreatic secretion, and they indicate that therapeutic coeliac ganglia ablation in man is unlikely to be detrimental to physiological pancreatic secretion.     

Angina without involvement of large coronary trunks and precapillary pulmonary hypertension in a patient with periarteritis nodosa

A patient affected with periarteritis nodosa and angina, presented a normal coronary angiography of the coronary trunks and an alteration of the left ventricular systolic function, improved by nicardipine, as well as a pre-capillary pulmonary hypertension with isolated, right cardiac repercussions, without pulmonary fibrosis nor thromboembolic disease. In addition, he presented three transient cerebral ischaemic accidents, with different localizations, which could not be related to a right aneurysm of the sylvian artery. Isolated precapillary pulmonary hypertension, without pulmonary fibrosis, which is not described in the course of periarteritis nodosa, seems related to an arteriolar involvement which is the known substratum of other visceral involvement in periarteritis nodosa. Improvement of the left ventricular function with nicardipine, administered acutely, suggest a partially reversible disorder of the coronary microcirculation.     

Asymmetric lateral mobility of phospholipids in the human erythrocyte membrane.

The fluorescent phospholipid 1-acyl-2-[12-(7-nitrobenz-2-oxa-1,3-diazol-4- yl)aminododecanoyl]phosphatidylcholine (NBD-phosphatidylcholine) and the corresponding aminophospholipid derivatives (NBD-phosphatidylethanolamine and NBD-phosphatidylserine) were introduced in the human erythrocyte membrane by a nonspecific phospholipid exchange protein purified from corn. The lateral mobility of the fluorescent phospholipids was measured by using an extension of the classical photobleaching recovery technique that takes advantage of a modulated fringe pattern and provides a high sensitivity. In intact erythrocytes and in ghosts resealed in the presence of ATP, the fluorescence-contrast curves after photobleaching decayed biexponentially corresponding to two lateral diffusion constants. With NBD-phosphatidylcholine, the majority of the signal corresponded to a "slow" component (1.08 X 10(-9) cm2/sec at 20 degrees C), whereas with the amino derivatives the majority of the signal corresponded to a "fast" component (5.14 X 10(-9) cm2/sec at 20 degrees C). If the ghosts were resealed without ATP, the fast component of the aminophospholipids disappeared. We interpret these results as follows: (i) Provided the cells or the ghosts contain ATP, the three fluorescent phospholipids distribute spontaneously between inner and outer leaflets as endogenous phospholipids, namely NBD-phosphatidylcholine is located in the outer leaflet, while both aminophospholipids are preferentially located in the inner leaflet. (ii) The viscosity of the inner leaflet of human erythrocyte membranes is lower than that of the outer leaflet.     

Bone marrow transplantation prolongs survival after relapse in aggressive-lymphoma patients treated with the LNH-84 regimen.

PURPOSE: Of the 737 patients with aggressive lymphoma who were treated with the LNH-84 regimen, 244 with progressive disease after complete remission or partial response were analyzed retrospectively to determine the influence of intensive chemotherapy with bone marrow transplantation (BMT) on survival. PATIENTS AND METHODS: Forty-four patients were treated with salvage chemotherapy, followed by autologous bone marrow transplantation (ABMT) in 40 and allogeneic BMT in four. The other 200 patients were treated with chemotherapy only. RESULTS: Salvage treatment produced an objective response in 57% of the patients; 23% achieved a second complete remission. Median overall survival was longer for patients who were treated with ABMT than for those who were treated with chemotherapy only (12.4 v 6.7 months), as was median freedom from progression (FFP) survival (7.7 v 4 months). In multiparametric analysis, ABMT and normal initial lactic dehydrogenase (LDH) level were the primary parameters associated with longer survival. This is also true when (1) only patients younger than 60 years of age, (2) only patients who responded to salvage regimen, or (3) only patients with both conditions were included in the analysis. Patients who were not transplanted had a 1.69 to 2.26 relative risk of dying from their disease compared with those who were treated with intensive chemotherapy plus ABMT. CONCLUSION: This study produced more evidence of the favorable impact of intensive chemotherapy with bone marrow rescue on survival in lymphoma patients who had relapsed.     

Transbilayer mobility and distribution of red cell phospholipids during storage.

We studied phospholipid topology and transbilayer mobility in red cells during blood storage. The distribution of phospholipids was determined by measuring the reactivity of phosphatidylethanolamine with fluorescamine and the degradation of phospholipids by phospholipase A2 and sphingomyelinase C. Phospholipid mobility was measured by determining transbilayer movements of spin-labeled phospholipids. We were unable to detect a change in the distribution of endogenous membrane phospholipids in stored red cells even after 2-mo storage. The rate of inward movement of spin-labeled phosphatidylethanolamine and phosphatidylserine was progressively reduced, whereas that for phosphatidylcholine was increased. These changes in phospholipid translocation correlated with a fall in cellular ATP. However, following restoration of ATP, neither the rate of aminophospholipid translocation nor the transbilayer movement of phosphatidylcholine were completely corrected. Taken together, our findings demonstrate that red cell storage alters the kinetics of transbilayer mobility of phosphatidylserine, phosphatidylethanolamine, and phosphatidylcholine, the activity of the aminophospholipid translocase, but not the asymmetric distribution of endogenous membrane phospholipids, at least at a level detectable with phospholipases. Thus, if phosphatidylserine appearance on the outer monolayer is a signal for red cell elimination, the amount that triggers macrophage recognition is below the level of detection upon using the phospholipase technique.