Paola Agui Gonzalez
@biodonostia.org
Clinical Research Associate at the Clinical Research Platform
HRI Biogipuzkoa
RESEARCH, TEACHING, or OTHER INTERESTS
Cell Biology, Neuroscience, Biochemistry, Genetics and Molecular Biology
Scopus Publications
Scopus Publications
Rodica Pena, Sarah L. Bluhm, Silke Ammerschubert, Paola Agüi-Gonzalez, Silvio O. Rizzoli, Stefan Scheu, and Andrea Polle
Springer Science and Business Media LLC
AbstractCarbon allocation of trees to ectomycorrhizas is thought to shape forest nutrient cycling, but the sink activities of different fungal taxa for host resources are unknown. Here, we investigate fungal taxon-specific differences in naturally composed ectomycorrhizal (EM) communities for plant-derived carbon and nitrogen. After aboveground dual labeling of young beech with 15N and 13C, ectomycorrhizas formed with different fungal taxa exhibit strong differences in label enrichment. Secondary Ion Mass Spectrometry (SIMS) imaging of nitrogen in cross sections of ectomycorrhizas demonstrates plant-derived 15N in both root and fungal structures. Isotope enrichment in ectomycorrhizas correlates with that in the corresponding ectomycorrhiza-attached lateral root, supporting fungal taxon-specific N and C fluxes in ectomycorrhizas. The enrichments with 13C and 15N in the symbiosis decrease with increasing C/N ratio of ectomycorrhizas, converging to zero at high C/N. The relative abundances of EM fungal species on roots are positively correlated with 13C enrichment, demonstrating higher fitness of stronger than of less C-demanding symbioses. Overall, our results support that differences among the C/N ratios in ectomycorrhizas formed with different fungal species regulate the supply of the symbioses with host-derived carbon and provide insights on functional traits of ectomycorrhizas, which are important for major ecosystem processes.
Martin Meschkat, Anna M. Steyer, Marie-Theres Weil, Kathrin Kusch, Olaf Jahn, Lars Piepkorn, Paola Agüi-Gonzalez, Nhu Thi Ngoc Phan, Torben Ruhwedel, Boguslawa Sadowski,et al.
Springer Science and Business Media LLC
AbstractMyelin, the electrically insulating sheath on axons, undergoes dynamic changes over time. However, it is composed of proteins with long lifetimes. This raises the question how such a stable structure is renewed. Here, we study the integrity of myelinated tracts after experimentally preventing the formation of new myelin in the CNS of adult mice, using an inducible Mbp null allele. Oligodendrocytes survive recombination, continue to express myelin genes, but they fail to maintain compacted myelin sheaths. Using 3D electron microscopy and mass spectrometry imaging we visualize myelin-like membranes failing to incorporate adaxonally, most prominently at juxta-paranodes. Myelinoid body formation indicates degradation of existing myelin at the abaxonal side and the inner tongue of the sheath. Thinning of compact myelin and shortening of internodes result in the loss of about 50% of myelin and axonal pathology within 20 weeks post recombination. In summary, our data suggest that functional axon-myelin units require the continuous incorporation of new myelin membranes.
Selda Kabatas Glowacki, Paola Agüi-Gonzalez, Shama Sograte-Idrissi, Sebastian Jähne, Felipe Opazo, Nhu T. N. Phan, and Silvio O. Rizzoli
Royal Society of Chemistry (RSC)
We developed here an iodine-containing probe that can be used to identify the molecules of interest in secondary ion mass spectrometry (SIMS) by simple immunolabelling procedures.
Tal M. Dankovich, Rahul Kaushik, Linda H. M. Olsthoorn, Gabriel Cassinelli Petersen, Philipp Emanuel Giro, Verena Kluever, Paola Agüi-Gonzalez, Katharina Grewe, Guobin Bao, Sabine Beuermann,et al.
Springer Science and Business Media LLC
AbstractThe brain extracellular matrix (ECM) consists of extremely long-lived proteins that assemble around neurons and synapses, to stabilize them. The ECM is thought to change only rarely, in relation to neuronal plasticity, through ECM proteolysis and renewed protein synthesis. We report here an alternative ECM remodeling mechanism, based on the recycling of ECM molecules. Using multiple ECM labeling and imaging assays, from super-resolution optical imaging to nanoscale secondary ion mass spectrometry, both in culture and in brain slices, we find that a key ECM protein, Tenascin-R, is frequently endocytosed, and later resurfaces, preferentially near synapses. The TNR molecules complete this cycle within ~3 days, in an activity-dependent fashion. Interfering with the recycling process perturbs severely neuronal function, strongly reducing synaptic vesicle exo- and endocytosis. We conclude that the neuronal ECM can be remodeled frequently through mechanisms that involve endocytosis and recycling of ECM proteins.
Paola Agüi-Gonzalez, Tal M. Dankovich, Silvio O. Rizzoli, and Nhu T. N. Phan
MDPI AG
Nanoscale imaging with the ability to identify cellular organelles and protein complexes has been a highly challenging subject in the secondary ion mass spectrometry (SIMS) of biological samples. This is because only a few isotopic tags can be used successfully to target specific proteins or organelles. To address this, we generated gold nanoprobes, in which gold nanoparticles are conjugated to nanobodies. The nanoprobes were well suited for specific molecular imaging using NanoSIMS at subcellular resolution. They were demonstrated to be highly selective to different proteins of interest and sufficiently sensitive for SIMS detection. The nanoprobes offer the possibility of correlating the investigation of cellular isotopic turnover to the positions of specific proteins and organelles, thereby enabling an understanding of functional and structural relations that are currently obscure.
Paola Agüi-Gonzalez, Bao Guobin, Maria A. Gomes de Castro, Silvio O. Rizzoli, and Nhu T. N. Phan
American Chemical Society (ACS)
The cellular functions of lipids in the neuronal plasma membranes have been increasingly acknowledged, particularly their association to neuronal processes and synaptic plasticity. However, the knowledge of their regulatory mechanisms in neuronal cells remains sparse. To address this, we investigated the lipid organization of the plasma membranes of hippocampal neurons in relation to neuronal activity using secondary ion mass spectrometry imaging. The neurons were treated with drugs, particularly tetrodotoxin (TTX) and bicuculline (BIC), to induce chronic activation and silencing. Distinct lipid organization was found in the plasma membrane of the cell body and the neurites. Moreover, significant alterations of the levels of the membrane lipids, especially ceramides, phosphatidylserines, phosphatidic acids, and triacylglycerols, were observed under the TTX and BIC treatments. We suggest that many types of membrane lipids are affected by, and may be involved in, the regulation of neuronal function.
Felix Lange, Paola Agüi-Gonzalez, Dietmar Riedel, Nhu T. N. Phan, Stefan Jakobs, and Silvio O. Rizzoli
Public Library of Science (PLoS)
Electron microscopy (EM) has been employed for decades to analyze cell structure. To also analyze the positions and functions of specific proteins, one typically relies on immuno-EM or on a correlation with fluorescence microscopy, in the form of correlated light and electron microscopy (CLEM). Nevertheless, neither of these procedures is able to also address the isotopic composition of cells. To solve this, a correlation with secondary ion mass spectrometry (SIMS) would be necessary. SIMS has been correlated in the past to EM or to fluorescence microscopy in biological samples, but not to CLEM. We achieved this here, using a protocol based on transmission EM, conventional epifluorescence microscopy and nanoSIMS. The protocol is easily applied, and enables the use of all three technologies at high performance parameters. We suggest that CLEM-SIMS will provide substantial information that is currently beyond the scope of conventional correlative approaches.
Sebastian Jähne, Fabian Mikulasch, Helge G.H. Heuer, Sven Truckenbrodt, Paola Agüi-Gonzalez, Katharina Grewe, Angela Vogts, Silvio O. Rizzoli, and Viola Priesemann
Elsevier BV
Paola Agüi-Gonzalez, Sebastian Jähne, and Nhu T. N. Phan
Royal Society of Chemistry (RSC)
Secondary ion mass spectrometry (SIMS) has been increasingly recognized as a powerful technique for visualizing molecular architectures in the fields of neurobiology and cell biology.
Selda Kabatas, Paola Agüi-Gonzalez, Rena Hinrichs, Sebastian Jähne, Felipe Opazo, Ulf Diederichsen, Silvio O. Rizzoli, and Nhu T. N. Phan
Royal Society of Chemistry (RSC)
Specific labeling of cellular proteins with fluorinated nanobodies enables their visualization in nanoSIMS.
Selda Kabatas, Paola Agüi‐Gonzalez, Kim‐Ann Saal, Sebastian Jähne, Felipe Opazo, Silvio O. Rizzoli, and Nhu T. N. Phan
Wiley
AbstractBoron has been employed in materials science as a marker for imaging specific structures by electron energy loss spectroscopy (EELS) or secondary ion mass spectrometry (SIMS). It has a strong potential in biological analyses as well; however, the specific coupling of a sufficient number of boron atoms to a biological structure has proven challenging. Herein, we synthesize tags containing closo‐1,2‐dicarbadodecaborane, coupled to soluble peptides, which were integrated in specific proteins by click chemistry in mammalian cells and were also coupled to nanobodies for use in immunocytochemistry experiments. The tags were fully functional in biological samples, as demonstrated by nanoSIMS imaging of cell cultures. The boron signal revealed the protein of interest, while other SIMS channels were used for imaging different positive ions, such as the cellular metal ions. This allows, for the first time, the simultaneous imaging of such ions with a protein of interest and will enable new biological applications in the SIMS field.