Research Article
James O. Park, Carlos A. Lopez, Vinay K. Gupta, Charles K. Brown, Helena J. Mauceri, Thomas E. Darga, Abdullah Manan, Samuel Hellman, Mitchell C. Posner, Donald W. Kufe, Ralph R. Weichselbaum
Research Article
Paul A. Crossey, Claire C. Pillai, John P. Miell
Research Article
Manabu Shirai, Tomoaki Osugi, Hideyuki Koga, Yoshikazu Kaji, Eiki Takimoto, Issei Komuro, Junichi Hara, Takeshi Miwa, Keiko Yamauchi-Takihara, Yoshihiro Takihara
Research Article
Simona Nanni, Michela Narducci, Linda Della Pietra, Fabiola Moretti, Annalisa Grasselli, Piero De Carli, Ada Sacchi, Alfredo Pontecorvi, Antonella Farsetti
Research Article
Duarte C. Barral, José S. Ramalho, Ross Anders, Alistair N. Hume, Holly J. Knapton, Tanya Tolmachova, Lucy M. Collinson, David Goulding, Kalwant S. Authi, Miguel C. Seabra
Research Article
Charles R. Roe, Lawrence Sweetman, Diane S. Roe, France David, Henri Brunengraber
Research Article
Junichi Sadoshima, Olivier Montagne, Qian Wang, Guiping Yang, Jill Warden, Jing Liu, Gen Takagi, Vijaya Karoor, Chull Hong, Gary L. Johnson, Dorothy E. Vatner, Stephen F. Vatner
Research Article
Clive R. Pullinger, Celeste Eng, Gerald Salen, Sarah Shefer, Ashok K. Batta, Sandra K. Erickson, Andrea Verhagen, Christopher R. Rivera, Sean J. Mulvihill, Mary J. Malloy, John P. Kane
We recently showed that human skin fibroblasts internalize fluorescent analogues of the glycosphingolipids lactosylceramide and globoside almost exclusively by a clathrin-independent mechanism involving caveolae. In contrast, a sphingomyelin analogue is internalized approximately equally via clathrin-dependent and caveolar routes. Here, we further characterized the caveolar pathway for glycosphingolipids, showing that Golgi targeting of sphingolipids internalized via caveolae required microtubules and phosphoinositol 3-kinases and was inhibited in cells expressing dominant-negative Rab7 and Rab9 constructs. In addition, overexpression of wild-type Rab7 or Rab9 (but not Rab11) in Niemann-Pick type C (NP-C) lipid storage disease fibroblasts resulted in correction of lipid trafficking defects, including restoration of Golgi targeting of fluorescent lactosylceramide and endogenous GM1 ganglioside, and a dramatic reduction in intracellular cholesterol stores. Our results demonstrate a role for Rab7 and Rab9 in the Golgi targeting of glycosphingolipids and suggest a new therapeutic approach for restoring normal lipid trafficking in NP-C cells.
Amit Choudhury, Michel Dominguez, Vishwajeet Puri, Deepak K. Sharma, Keishi Narita, Christine L. Wheatley, David L. Marks, Richard E. Pagano
Tissue-type plasminogen activator (tPA) is a highly specific serine proteinase expressed in the CNS during events that require neuronal plasticity. In this study we demonstrate that endogenous tPA mediates the progression of kainic acid–induced (KA-induced) seizures by promoting the synchronization of neuronal activity required for seizure spreading, and that, unlike KA-induced cell death, this activity is plasminogen-independent. Specifically, seizure induction by KA injection into the amygdala induces tPA activity and cell death in both hippocampi, and unilateral treatment of rats with neuroserpin, a natural inhibitor of tPA in the brain, enhances neuronal survival in both hippocampi. Inhibition of tPA within the hippocampus by neuroserpin treatment does not prevent seizure onset but instead markedly delays the progression of seizure activity in both rats and wild-type mice. In tPA-deficient mice, seizure progression is significantly delayed, and neuroserpin treatment does not further delay seizure spreading. In contrast, plasminogen-deficient mice show a pattern of seizure spreading and a response to neuroserpin that is similar to that of wild-type animals. These findings indicate that tPA acts on a substrate other than plasminogen and that the effects of neuroserpin on seizure progression and neuronal cell survival are mediated through the inhibition of tPA.
Manuel Yepes, Maria Sandkvist, Timothy A. Coleman, Elizabeth Moore, Jiang-Young Wu, David Mitola, Thomas H. Bugge, Daniel A. Lawrence