Enrique Torre - Academia.edu (original) (raw)

Papers by Enrique Torre

Journal of Biological Chemistry, 2003

Coat proteins cycle between soluble and membranebound locations at the time of vesicle biogenesis... more Coat proteins cycle between soluble and membranebound locations at the time of vesicle biogenesis and act to regulate the assembly of the vesicle coat that determines the specificity in cargo selection and the destination of the vesicle. A transmembrane cargo protein, an Arf GTPase, and a coat protein (e.g. COPs, APs, or GGAs) are minimal components required for budding of vesicles. Munc18 interacting proteins (MINTs) are a family of three proteins implicated in the localization of receptors to the plasma membrane. We show that MINTs bind Arfs directly, co-localize with Arf and the Alzheimer's precursor protein (␤-APP) to regions of the Golgi/trans-Golgi network, and can co-immunoprecipitate clathrin. We demonstrate that MINTs bind Arfs through a region of the PTB domain and the PDZ2 domain, and Arf-MINT interaction is necessary for the increased cellular levels of ␤-APP produced by MINT overexpression. Knockdown (small interference RNA) experiments implicate ␤-APP as a transmembrane cargo protein that works together with MINTs. We propose that MINTs are a family of Arf-dependent, vesicle-coat proteins that can regulate the traffic of ␤-APP.

Journal of Biological Chemistry, 2019

Growth-associated protein 43 (GAP-43) plays a central role in the formation of presynaptic termin... more Growth-associated protein 43 (GAP-43) plays a central role in the formation of presynaptic terminals, synaptic plasticity, and axonal growth and regeneration. During development, GAP-43 is found in axonal extensions of most neurons. In contrast, in the mature brain, its expression is restricted to a few presynaptic terminals and scattered axonal growth cones. Urokinase-type plasminogen activator (uPA) is a serine proteinase that, upon binding to its receptor (uPAR), catalyzes the conversion of plasminogen into plasmin and activates signaling pathways that promote cell migration, proliferation, and survival. In the developing brain, uPA induces neuritogenesis and neuronal migration. In contrast, the expression and function of uPA in the mature brain are poorly understood. However, recent evidence reveals that different forms of injury induce release of uPA and expression of uPAR in neurons and that uPA/uPAR binding triggers axonal growth and synapse formation. Here we show that bindi...

Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism, Mar 1, 2018

Cerebral ischemia causes the presynaptic release of tissue-type plasminogen activator (tPA). The ... more Cerebral ischemia causes the presynaptic release of tissue-type plasminogen activator (tPA). The postsynaptic density (PSD) is a postsynaptic structure that provides a matrix where signaling transduction of excitatory synapses takes place. The postsynaptic density protein-95 (PSD-95) is the most abundant scaffolding protein in the postsynaptic density (PSD), where it modulates the postsynaptic response to the presynaptic release of glutamate by regulating the anchoring of glutamate receptors to the PSD. We found that tPA induces the local translation of PSD-95 mRNA and the subsequent recruitment of PSD-95 protein to the PSD, via plasminogen-independent activation of TrkB receptors. Our data show that PSD-95 is removed from the PSD during the early stages of cerebral ischemia, and that this effect is abrogated by either the release of neuronal tPA, or intravenous administration of recombinant tPA (rtPA). We report that the effect of tPA on PSD-95 is associated with inhibition of the ...

The Journal of biological chemistry, Feb 17, 2017

Axonal injury is a common cause of neurological dysfunction. Unfortunately, in contrast to axons ... more Axonal injury is a common cause of neurological dysfunction. Unfortunately, in contrast to axons from the peripheral nervous system, the limited capacity of regeneration of central nervous system (CNS) axons is a major obstacle for functional recovery in patients suffering neurological diseases that involve the subcortical white matter. Urokinase-type plasminogen activator (uPA) is a serine proteinase that upon binding to the urokinase-type plasminogen activator receptor (uPAR) catalyzes the conversion of plasminogen into plasmin on the cell surface. uPAR expression increases after an injury, and signaling through uPAR promotes tissue remodeling. However, it is yet unknown whether uPA binding to uPAR has an effect on axonal recovery in the CNS. Here, we used in vitro and in vivo models of CNS axonal injury to test the hypothesis that uPA binding to uPAR promotes axonal regeneration in the CNS. We found that newly formed growth cones from axons re-emerging from an axonal injury expre...

Neuroscience, 2016

The release of the serine proteinase tissue-type plasminogen activator (tPA) from the presynaptic... more The release of the serine proteinase tissue-type plasminogen activator (tPA) from the presynaptic terminal of cerebral cortical neurons plays a central role in the development of synaptic plasticity, adaptation to metabolic stress and neuronal survival. Our earlier studies indicate that by inducing the recruitment of the cytoskeletal protein βII-spectrin and voltage-gated calcium channels to the active zone (AZ), tPA promotes Ca 2+-dependent translocation of synaptic vesicles (SVs) to the synaptic release site where they release their load of neurotransmitters into the synaptic cleft. Here we used a combination of in vivo and in vitro experiments to investigate whether this effect leads to depletion of SVs in the presynaptic terminal. Our data indicate that tPA promotes SVs endocytosis via a mechanism that does not require the conversion of plasminogen into plasmin. Instead, we show that tPA induces calcineurin (CaN)-mediated dynamin I dephosphorylation, which is followed by dynamin I-induced recruitment of the actin binding protein profilin II to the presynaptic membrane, and profilin II-induced F-actin formation. We report that this tPA-induced sequence of events leads to the association of newly formed SVs with F-actin clusters in the endocytic zone. In summary, the data presented here indicate that following the exocytotic release of neurotransmitters tPA activates the mechanism whereby SVs are retrieved from the presynaptic membrane and endocytosed to replenish the pool of vesicles available for a new cycle of exocytosis. Together, these results indicate that in cerebral cortical neurons tPA plays a central role coupling SVs exocytosis and endocytosis.

Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism, 2015

The active zone (AZ) is a thickening of the presynaptic membrane where exocytosis takes place. Ch... more The active zone (AZ) is a thickening of the presynaptic membrane where exocytosis takes place. Chemical synapses contain neurotransmitter-loaded synaptic vesicles (SVs) that at rest are tethered away from the synaptic release site, but after the presynaptic inflow of Ca(+2) elicited by an action potential translocate to the AZ to release their neurotransmitter load. We report that tissue-type plasminogen activator (tPA) is stored outside the AZ of cerebral cortical neurons, either intermixed with small clear-core vesicles or in direct contact with the presynaptic membrane. We found that cerebral ischemia-induced release of neuronal tPA, or treatment with recombinant tPA, recruits the cytoskeletal protein βII-spectrin to the AZ and promotes the binding of SVs to βII-spectrin, enlarging the population of SVs in proximity to the synaptic release site. This effect does not require the generation of plasmin and is followed by the recruitment of voltage gated calcium channels (VGCC) to th...

Cell Transplantation, 2007

The dogma that the adult central nervous system (CNS) is nonpermissive to axonal regeneration is ... more The dogma that the adult central nervous system (CNS) is nonpermissive to axonal regeneration is beginning to fall in the face of increased understanding of the molecular and cellular biology of axon outgrowth. It is now appreciated that axon growth is regulated by a combination of extracellular factors related to the milieu of the developing or adult CNS and the presence of injury, and intracellular factors related to the “growth state” of the developing or regenerating neuron. Several critical points of convergence within the developing or regenerating neuron for mediating intracellular cell signaling effects on the growth cone cytoskeleton have been identified, and their modulation has produced marked increases in axon outgrowth within the “nonpermissive” milieu of the adult injured CNS. One such critical convergence point is the small GTPase RhoA, which integrates signaling events produced by both myelin-associated inhibitors (e.g., NogoA) and astroglial-derived inhibitors (chon...

The EMBO journal, 2003

Huntingtin interacting protein 1 (HIP1) is a recently identified component of clathrin-coated ves... more Huntingtin interacting protein 1 (HIP1) is a recently identified component of clathrin-coated vesicles that plays a role in clathrin-mediated endocytosis. To explore the normal function of HIP1 in vivo, we created mice with targeted mutation in the HIP1 gene (HIP1(-/-)). HIP1(-/-) mice develop a neurological phenotype by 3 months of age manifest with a failure to thrive, tremor and a gait ataxia secondary to a rigid thoracolumbar kyphosis accompanied by decreased assembly of endocytic protein complexes on liposomal membranes. In primary hippocampal neurons, HIP1 colocalizes with GluR1-containing AMPA receptors and becomes concentrated in cell bodies following AMPA stimulation. Moreover, a profound dose-dependent defect in clathrin-mediated internalization of GluR1-containing AMPA receptors was observed in neurons from HIP1(-/-) mice. Together, these data provide strong evidence that HIP1 regulates AMPA receptor trafficking in the central nervous system through its function in clathr...

Proceedings of the National Academy of Sciences, 1991

Neuronal gene expression is known to be modulated by functional activity. This modulation is thou... more Neuronal gene expression is known to be modulated by functional activity. This modulation is thought to play a key role in determining the differentiation of developing neurons and regulating the operation of mature neurons. Here we describe a regulation of astroglial gene expression by neuronal activity. We report that intense neuronal activity (electrically induced seizures) in rat hippocampus leads to rapid and dramatic increases in mRNA for glial fibrillary acidic protein (GFAP), an astroglia-specific intermediate filament protein. GFAP mRNA levels increased at sites of stimulation as well as in areas that were synaptically activated by the resultant seizures. When seizures were induced repetitively for many days, levels of GFAP mRNA remained chronically elevated. However, GFAP mRNA returned to control levels within a few days after the cessation of stimulation. The coupling between astroglial gene expression and neuronal activity may be a mechanism through which neuronal activi...

Neurobiology of Disease, 2002

Molecular and Cellular Neuroscience, 2000

Huntingtin-associated protein-1 (HAP1) binds more tightly to mutant huntingtin, but its function ... more Huntingtin-associated protein-1 (HAP1) binds more tightly to mutant huntingtin, but its function and distribution in neurites are not clear. Using PC12 cells and cultured hippocampal neurons, we found that two HAP1 isoforms, HAP1-A and HAP1-B, have different subcellular localizations. While most HAP1-B is diffusely distributed within the cytoplasm, HAP1-A is enriched in the growth cones and neuritic puncta of developing neurons. In mature neurons and adult brain neurons, however, HAP1-A is concentrated in axon terminals and associated with synaptic vesicles. Transfection of HAP1-A in PC12 cells significantly promotes neurite extension, with HAP1-A distributed in the distal regions of the growing neurites. Cotransfection of mutant huntingtin with HAP1-A in PC12 cells results in the accumulation of HAP1-A on huntingtin aggregates and the inhibition of neurite promotion by HAP1-A. This study suggests that HAP1-A has a function in neuritic development and synaptic function and that mutant huntingtin may alter this function.

Journal of Histochemistry & Cytochemistry, 2003

Stigmoid bodies (SBs) are structures in the cytoplasm of neurons. SBs are mostly found in the hyp... more Stigmoid bodies (SBs) are structures in the cytoplasm of neurons. SBs are mostly found in the hypothalamic region of the rat and contain a protein called huntingtin-associated protein 1 (HAP1). In a recent publication, large cytoplasmic structures were shown to be immunoreactive for a type I receptor called SorLA/LR11. By light microscopic analysis, these structures appeared similar to SBs in size and in brain regional and subcellular localization. To determine whether these large puncta correspond to HAP1-containing SBs, we used antibodies specific to various domains of the apolipoprotein receptor LR11 to perform immunocytochemistry in rat and mouse brain tissue. Transfection studies using HeLa cells were conducted to demonstrate the specificity of the antibodies. We found that, in both species, antibodies to the domain II (or VSP10 for vacuolar sorting protein 10 domain) of LR11 immunoreact with large cytoplasmic structures. Co-localization immunolabeling experiments in rat brain ...

Gastroenterology, 2008

Background and Aims-The isolation and culture of primary enteric neurons is a difficult process a... more Background and Aims-The isolation and culture of primary enteric neurons is a difficult process and yields a small number of neurons. We developed fetal (IM-FEN) and postnatal (IM-PEN) enteric neuronal cell lines using the H-2K b-tsA58 transgenic mice that have a temperature sensitive mutation of the SV-40 large tumor antigen gene under the control of an interferon γ-inducible H-2K b promoter element. Methods-Enteric neuronal precursors were isolated from the intestines of E13-mouse fetuses and second day post natal mice using magnetic immunoselection with a p75 NTR antibody. The cells were maintained at the permissive temperature, 33°C and IFN-γ for 24 or 48 h and then transferred to 39°C in the presence of GDNF for 7 days for further differentiation. Neuronal markers were assessed by RT-PCR, western blot and immunocytochemistry. Neuronal function was assessed by transplanting these cells into the colons of Piebald or nNOS −/− mice. Results-Expression analysis of cells showed the presence of neuronal markers peripherin, PGP9.5, HuD, Tau, synaptic marker Synaptophysin, characteristic receptors of enteric neurons, Ret and 5-HT receptor subtypes at 33°C and 39°C. Nestin, S-100β and α-SMA were minimally expressed at 39°C. GDNF resulted in increased phosphorylation of Akt in these cells, similar to primary enteric neurons. Transplantation of cells into the piebald or nNOS −/− mice colon improved colonic motility. Conclusions-We have developed novel enteric neuronal cell lines that have neuronal characteristics similar to primary enteric neurons. These cells can help us in understanding newer therapeutic options for Hirschsprung's disease.

Experimental Neurology, 2006

Cell, 2008

The brain produces two brain-derived neurotrophic factor (BDNF) transcripts, with either short or... more The brain produces two brain-derived neurotrophic factor (BDNF) transcripts, with either short or long 3 0 untranslated regions (3 0 UTRs). The physiological significance of the two forms of mRNAs encoding the same protein is unknown. Here, we show that the short and long 3 0 UTR BDNF mRNAs are involved in different cellular functions. The short 3 0 UTR mRNAs are restricted to somata, whereas the long 3 0 UTR mRNAs are also localized in dendrites. In a mouse mutant where the long 3 0 UTR is truncated, dendritic targeting of BDNF mRNAs is impaired. There is little BDNF in hippocampal dendrites despite normal levels of total BDNF protein. This mutant exhibits deficits in pruning and enlargement of dendritic spines, as well as selective impairment in long-term potentiation in dendrites, but not somata, of hippocampal neurons. These results provide insights into local and dendritic actions of BDNF and reveal a mechanism for differential regulation of subcellular functions of proteins.

The Journal of Neuroscience, 2020

Circulation, 2011

Background— Urokinase-type plasminogen activator (uPA) has recently been implicated in the pathog... more Background— Urokinase-type plasminogen activator (uPA) has recently been implicated in the pathogenesis of ischemia-reperfusion (I/R) injury. The underlying mechanisms remain largely unclear. Methods and Results— Using in vivo microscopy on the mouse cremaster muscle, I/R-elicited firm adherence and transmigration of neutrophils were found to be significantly diminished in uPA-deficient mice and in mice treated with the uPA inhibitor WX-340, but not in uPA receptor (uPAR)–deficient mice. Interestingly, postischemic leukocyte responses were significantly reduced on blockade of the integrin CD11b/Mac-1, which also serves as uPAR receptor. Using a cell transfer technique, postischemic adherence and transmigration of wild-type leukocytes were significantly decreased in uPA-deficient animals, whereas uPA-deficient leukocytes exhibited a selectively reduced transmigration in wild-type animals. On I/R or stimulation with recombinant uPA, >90% of firmly adherent leukocytes colocalized wi...

Journal of Cell Science

Urokinase-type plasminogen activator (uPA; encoded by Plau) is a serine proteinase that, in the c... more Urokinase-type plasminogen activator (uPA; encoded by Plau) is a serine proteinase that, in the central nervous system, induces astrocytic activation. β-Catenin is a protein that links the cytoplasmic tail of cadherins to the actin cytoskeleton, thus securing the formation of cadherin-mediated cell adhesion complexes. Disruption of cell–cell contacts leads to the detachment of β-catenin from cadherins, and β-catenin is then degraded by the proteasome following its phosphorylation by GSK3β. Here, we show that astrocytes release uPA following a scratch injury, and that this uPA promotes wound healing via a plasminogen-independent mechanism. We found that uPA induces the detachment of β-catenin from the cytoplasmic tail of N-cadherin (NCAD; also known as CDH2) by triggering its phosphorylation at Tyr654. Surprisingly, this is not followed by degradation of β-catenin because uPA also induces the phosphorylation of the low density lipoprotein receptor-related protein 6 (LRP6) at Ser1490,...

Supplemental material, sj-pdf-1-jcb-10.1177_0271678X211002297 for Urokinase-type plasminogen acti... more Supplemental material, sj-pdf-1-jcb-10.1177_0271678X211002297 for Urokinase-type plasminogen activator promotes N-cadherin-mediated synaptic recovery in the ischemic brain by Ariel Diaz, Paola Merino, Patrick McCann, Manuel A Yepes, Laura G Quiceno, Enrique Torre, Amelia Tomkins, Xiaodong Zhang, Chadwick M Hales, Frank C Tong and Manuel Yepes in Journal of Cerebral Blood Flow & Metabolism