The Parkinson's disease-associated GPR37 receptor interacts with striatal adenosine A2A receptor controlling its cell surface expression and function in vivo

G protein-coupled receptor 37 (GPR37) is an orphan receptor associated to Parkinson's disease (PD) neuropathology. Here, we identified GPR37 as an inhibitor of adenosine A2A receptor (A2AR) cell surface expression and function in vivo. In addition, we showed that GPR37 and A2AR do oligomerize in the striatum. Thus, a close proximity of GPR37 and A2AR at the postsynaptic level of striatal synapses was observed by double-labelling post-embedding immunogold detection. Indeed, the direct receptor-receptor interaction was further substantiated by proximity ligation in situ assay. Interestingly, GPR37 deletion promoted striatal A2AR cell surface expression that correlated well with an increased A2AR agonist-mediated cAMP accumulation, both in primary striatal neurons and nerve terminals. Furthermore, GPR37−/− mice showed enhanced A2AR agonist-induced catalepsy and an increased response to A2AR antagonist-mediated locomotor activity. Overall, these results revealed a key role for GPR37 controlling A2AR biology in the striatum, which may be relevant for PD management

The CDR1 and other regions of immunoglobulin light chains are hot spots for amyloid aggregation

Immunoglobulin light chain-derived (AL) amyloidosis is a debilitating disease without known cure. Almost nothing is known about the structural factors driving the amyloidogenesis of the light chains. This study aimed to identify the fibrillogenic hotspots of the model protein 6aJL2 and in pursuing this goal, two complementary approaches were applied. One of them was based on several web-based computational tools optimized to predict fibrillogenic/aggregation-prone sequences based on different structural and biophysical properties of the polypeptide chain. Then, the predictions were confirmed with an ad-hoc synthetic peptide library. In the second approach, 6aJL2 protein was proteolyzed with trypsin, and the products incubated in aggregation-promoting conditions. Then, the aggregation-prone fragments were identified by combining standard proteomic methods, and the results validated with a set of synthetic peptides with the sequence of the tryptic fragments. Both strategies coincided to identify a fibrillogenic hotspot located at the CDR1 and β-strand C of the protein, which was confirmed by scanning proline mutagenesis analysis. However, only the proteolysis-based strategy revealed additional fibrillogenic hotspots in two other regions of the protein. It was shown that a fibrillogenic hotspot associated to the CDR1 is also encoded by several κ and λ germline variable domain gene segments. Some parts of this study have been included in the chapter “The Structural Determinants of the Immunoglobulin Light Chain Amyloid Aggregation”, published in Physical Biology of Proteins and Peptides, Springer 2015 (ISBN 978-3-319-21687-4)

The Parkinson’s disease-associated GPR37 receptor interacts with striatal adenosine A2A receptor controlling its cell surface expression and function in vivo

Abstract G protein-coupled receptor 37 (GPR37) is an orphan receptor associated to Parkinson’s disease (PD) neuropathology. Here, we identified GPR37 as an inhibitor of adenosine A2A receptor (A2AR) cell surface expression and function in vivo. In addition, we showed that GPR37 and A2AR do oligomerize in the striatum. Thus, a close proximity of GPR37 and A2AR at the postsynaptic level of striatal synapses was observed by double-labelling post-embedding immunogold detection. Indeed, the direct receptor-receptor interaction was further substantiated by proximity ligation in situ assay. Interestingly, GPR37 deletion promoted striatal A2AR cell surface expression that correlated well with an increased A2AR agonist-mediated cAMP accumulation, both in primary striatal neurons and nerve terminals. Furthermore, GPR37−/− mice showed enhanced A2AR agonist-induced catalepsy and an increased response to A2AR antagonist-mediated locomotor activity. Overall, these results revealed a key role for GPR37 controlling A2AR biology in the striatum, which may be relevant for PD management

Identification of novel vaccine candidates against cryptosporidiosis of neonatal bovines by reverse vaccinology

The apicomplexan protozoan Cryptosporidium parvum is an important causative agent of diarrhea of neonatal bovines. Vaccination has been proposed as an advantageous strategy against cryptosporidiosis of calves since besides protection against disease it has also the potential to prevent dissemination of infective oocysts into the environment. Antigens anchored to the parasite surface via glycosylphosphatidylinositol (GPI) are implicated in host cell attachment and invasion and represent promising vaccine candidates. A reverse vaccinology approach was employed to (i) identify the GPI-anchored proteome of C. parvum using available web-based bioinformatic tools and (ii) characterize previously unrecognized novel vaccine antigens. Altogether, 14 putative GPI-anchored proteins could be determined of which CpH1 and CpSUB2 as well as GP60 were further characterized. Sequencing and comparison of GP60, CpH1, and CpSUB1 alleles amplified from different geographic isolates showed a high degree of conservation. All three antigens were recombinant expressed and immunoblotted using sera of 12 Cryptosporidium-infected calves sampled at age periods 1–11 and 12–28 days after birth. Specific antibody reactions against the studied antigens were detected in all analyzed calves, demonstrating their immunreactivity and expression, and recognition in vivo at an early stage of host infection. Besides the acknowledged GP60 vaccinogen, the presented reverse vaccinology approach reveals the additional vaccine candidates CpH1 and CpSUB1 for inclusion into a subunit vaccine formulation.Fil: Tomazic, Mariela Luján. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas; ArgentinaFil: Rodriguez, A. E.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas; ArgentinaFil: Lombardelli, Joaquín Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Patología Animal; ArgentinaFil: Poklépovich Caride, Tomás Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas; ArgentinaFil: Garro, C.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas; ArgentinaFil: Galarza, R.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Tiranti, Karina Ivana. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Patología Animal; ArgentinaFil: Florin-Christensen, Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas; Argentina. Universidad de Morón. Facultad de Ciencias Exactas, Químicas y Naturales; ArgentinaFil: Schnittger, Leonhard. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas; Argentina. Universidad de Morón. Facultad de Ciencias Exactas, Químicas y Naturales; Argentin