Open Access
Neuroanatomical quantitative proteomics reveals common pathogenic biological routes between amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD)
(MDPI, 2019) Iridoy Zulet, Marina; Zubiri, Irene; Zelaya Huerta, María Victoria; Martínez, Leire; Ausín, Karina; Lachén Montes, Mercedes; Santamaría Martínez, Enrique; Fernández Irigoyen, Joaquín; Jericó Pascual, Ivonne; Ciencias de la Salud; Osasun Zientziak; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
(1) Background: Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are neurodegenerative disorders with an overlap in clinical presentation and neuropathology. Common and differential mechanisms leading to protein expression changes and neurodegeneration in ALS and FTD were studied trough a deep neuroproteome mapping of the spinal cord. (2) Methods: A liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis of the spinal cord from ALS-TAR DNA-binding protein 43 (TDP-43) subjects, ubiquitin-positive frontotemporal lobar degeneration (FTLD-U) subjects and controls without neurodegenerative disease was performed. (3) Results: 281 differentially expressed proteins were detected among ALS versus controls, while 52 proteins were dysregulated among FTLD-U versus controls. Thirty-three differential proteins were shared between both syndromes. The resulting data was subjected to network-driven proteomics analysis, revealing mitochondrial dysfunction and metabolic impairment, both for ALS and FTLD-U that could be validated through the confirmation of expression levels changes of the Prohibitin (PHB) complex. (4) Conclusions: ALS-TDP-43 and FTLD-U share molecular and functional alterations, although part of the proteostatic impairment is region-and disease-specific. We have confirmed the involvement of specific proteins previously associated with ALS (Galectin 2 (LGALS3), Transthyretin (TTR), Protein S100-A6 (S100A6), and Protein S100-A11 (S100A11)) and have shown the involvement of proteins not previously described in the ALS context (Methanethiol oxidase (SELENBP1), Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN-1), Calcyclin-binding protein (CACYBP) and Rho-associated protein kinase 2 (ROCK2)). © 2018 by the authors. Licensee MDPI, Basel, Switzerland.
Open Access
Familial globular glial tauopathy linked to MAPT mutations: molecular neuropathology and seeding capacity of a prototypical mixed neuronal and glial tauopathy
(Springer, 2020) Ferrer, Isidro; Andrés Benito, Pol; Zelaya Huerta, María Victoria; Erro Aguirre, María Elena; Carmona, Margarita; Ausín, Karina; Lachén Montes, Mercedes; Fernández Irigoyen, Joaquín; Santamaría Martínez, Enrique; Río, José Antonio del; Ciencias de la Salud; Osasun Zientziak; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Globular glial tauopathy (GGT) is a progressive neurodegenerative disease involving the grey matter and white matter (WM) and characterized by neuronal deposition of hyper-phosphorylated, abnormally conformed, truncated, oligomeric 4Rtau in neurons and in glial cells forming typical globular astrocyte and oligodendrocyte inclusions (GAIs and GOIs, respectively) and coiled bodies. Present studies centre on four genetic GGT cases from two unrelated families bearing the P301T mutation in MAPT and one case of sporadic GGT (sGGT) and one case of GGT linked to MAPT K317M mutation, for comparative purposes. Clinical and neuropathological manifestations and biochemical profiles of phospho-tau are subjected to individual variations in patients carrying the same mutation, even in carriers of the same family, independently of the age of onset, gender, and duration of the disease. Immunohistochemistry, western blotting, transcriptomic, proteomics and phosphoproteomics, and intra-cerebral inoculation of brain homogenates to wild-type (WT) mice were the methods employed. In GGT cases linked to MAPT P301T mutation, astrocyte markers GFAP, ALDH1L1, YKL40 mRNA and protein, GJA1 mRNA, and AQ4 protein are significantly increased; glutamate transporter GLT1 (EAAT2) and glucose transporter (SLC2A1) decreased; mitochondrial pyruvate carrier 1 (MPC1) increased, and mitochondrial uncoupling protein 5 (UCP5) almost absent in GAIs in frontal cortex (FC). Expression of oligodendrocyte markers OLIG1 and OLIG2mRNA, and myelin-related genes MBP, PLP1, CNP, MAG, MAL, MOG, and MOBP are significantly decreased in WM; CNPase, PLP1, and MBP antibodies reveal reduction and disruption of myelinated fibres; and SMI31 antibodies mark axonal damage in the WM. Altered expression of AQ4, GLUC-t, and GLT-1 is also observed in sGGT and in GGT linked to MAPT K317M mutation. These alterations point to primary astrogliopathy and oligodendrogliopathy in GGT. In addition, GGT linked to MAPT P301T mutation proteotypes unveil a proteostatic imbalance due to widespread (phospho)proteomic dearrangement in the FC and WM, triggering a disruption of neuron projection morphogenesis and synaptic transmission. Identification of hyper-phosphorylation of variegated proteins calls into question the concept of phospho-tau-only alteration in the pathogenesis of GGT. Finally, unilateral inoculation of sarkosyl-insoluble fractions of GGT homogenates from GGT linked to MAPT P301T, sGGT, and GGT linked to MAPT K317M mutation in the hippocampus, corpus callosum, or caudate/putamen in wild-type mice produces seeding, and time- and region-dependent spreading of phosphorylated, non-oligomeric, and non-truncated 4Rtau and 3Rtau, without GAIs and GOIs but only of coiled bodies. These experiments prove that host tau strains are important in the modulation of cellular vulnerability and phenotypes of phospho-tau aggregates.
Open Access
Olfactory bulb proteomics reveals widespread proteostatic disturbances in mixed dementia and guides for potential serum biomarkers to discriminate alzheimer disease and mixed dementia phenotypes
(MDPI, 2021) Lachén Montes, Mercedes; Íñigo-Marco, Ignacio; Cartas Cejudo, Paz; Fernández Irigoyen, Joaquín; Santamaría Martínez, Enrique; Ciencias de la Salud; Osasun Zientziak; Gobierno de Navarra / Nafarroako Gobernua
The most common form of mixed dementia (MixD) is constituted by abnormal protein deposits associated with Alzheimer's disease (AD) that coexist with vascular disease. Although olfactory dysfunction is considered a clinical sign of AD-related dementias, little is known about the impact of this sensorial impairment in MixD at the molecular level. To address this gap in knowledge, we assessed olfactory bulb (OB) proteome-wide expression in MixD subjects (n = 6) respect to neurologically intact controls (n = 7). Around 9% of the quantified proteins were differentially expressed, pinpointing aberrant proteostasis involved in synaptic transmission, nucleoside monophosphate and carbohydrate metabolism, and neuron projection regeneration. In addition, network-driven proteomics revealed a modulation in cell-survival related pathways such as ERK, AKT, and the PDK1-PKC axis. Part of the differential OB protein set was not specific of MixD, also being deregulated across different tauopathies, synucleinopathies, and tardopathies. However, the comparative functional analysis of OB proteome data between MixD and pure AD pathologies deciphered commonalities and differences between both related phenotypes. Finally, olfactory pro-teomics allowed to propose serum Prolow-density lipoprotein receptor-related protein 1 (LRP1) as a candidate marker to differentiate AD from MixD phenotypes.
Open Access
Early-onset molecular derangements in the olfactory bulb of Tg2576 mice: novel insights into the stress-responsive olfactory kinase dynamics in Alzheimer’s disease
(Frontiers Media, 2019) Lachén Montes, Mercedes; González Morales, Andrea; Palomino Alonso, Maialen; Ausín, Karina; Gómez-Ochoa, Marta; Zelaya Huerta, María Victoria; Ferrer, Isidro; Pérez Mediavilla, Alberto; Fernández Irigoyen, Joaquín; Santamaría Martínez, Enrique; Ciencias de la Salud; Osasun Zientziak; Gobierno de Navarra / Nafarroako Gobernua; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The olfactory bulb (OB) is the first processing station in the olfactory pathway. Despite smell impairment, which is considered an early event in Alzheimer’s disease (AD), little is known about the initial molecular disturbances that accompany the AD development at olfactory level. We have interrogated the time-dependent OB molecular landscape in Tg2576 AD mice prior to the appearance of neuropathological amyloid plaques (2-, and 6-month-old), using combinatorial omics analysis. The metabolic modulation induced by overproduction of human mutated amyloid precursor protein (APP) clearly differs between both time points. Besides the progressive perturbation of the APP interactome, functional network analysis unveiled an inverse regulation of downstream extracellular signal-regulated kinase (ERK1/2), and p38 mitogen-activated protein kinase (MAPK) routes in 2-month-old Tg2576 mice with respect to wild-type (WT) mice. In contrast, Akt and MAPK kinase 4 (SEK1)/ stress-activated protein kinase (SAPK) axis were parallel activated in the OB of 6-months-old-Tg2576 mice. Furthermore, a survival kinome profiling performed during the aging process (2-, 6-, and 18-month-old) revealed that olfactory APP overexpression leads to changes in the activation dynamics of protein kinase A (PKA), and SEK1/MKK4-SAPK/JNK between 6 and 18 months of age, when memory deficits appear and AD pathology is well established in transgenic mice. Interestingly, both olfactory pathways were differentially activated in a stage-dependent manner in human sporadic AD subjects with different neuropathological grading. Taken together, our data reflect the early impact of mutated APP on the OB molecular homeostasis, highlighting the progressive modulation of specific signaling pathways during the olfactory amyloidogenic pathology.
Open Access
Amyloid-driven tau accumulation on mitochondria potentially leads to cognitive deterioration in Alzheimer’s disease
(MDPI, 2021) Cuadrado-Tejedor, Mar; Pérez-González, Marta; Alfaro-Ruiz, Rocío; Badesso, Sara; Sucunza, Diego; Espelosín, María; Ursúa, Susana; Lachén Montes, Mercedes; Fernández Irigoyen, Joaquín; Santamaría Martínez, Enrique; Luján, Rafael; García-Osta, Ana; Ciencias de la Salud; Osasun Zientziak; Gobierno de Navarra / Nafarroako Gobernua
Despite the well-accepted role of the two main neuropathological markers (β-amyloid and tau) in the progression of Alzheimer’s disease, the interaction and specific contribution of each of them is not fully elucidated. To address this question, in the present study, an adeno-associated virus (AAV9) carrying the mutant P301L form of human tau, was injected into the dorsal hippocampi of APP/PS1 transgenic mice or wild type mice (WT). Three months after injections, memory tasks, biochemical and immunohistochemical analysis were performed. We found that the overexpression of hTauP301L accelerates memory deficits in APP/PS1 mice, but it did not affect memory function of WT mice. Likewise, biochemical assays showed that only in the case of APP/PS1-hTauP301L injected mice, an important accumulation of tau was observed in the insoluble urea fraction. Similarly, electron microscopy images revealed that numerous clusters of tau immunoparticles appear at the dendrites of APP/PS1 injected mice and not in WT animals, suggesting that the presence of amyloid is necessary to induce tau aggregation. Interestingly, these tau immunoparticles accumulate in dendritic mitochondria in the APP/PS1 mice, whereas most of mitochondria in WT injected mice remain free of tau immunoparticles. Taken together, it seems that amyloid induces tau aggregation and accumulation in the dendritic mitochondria and subsequently may alter synapse function, thus, contributing to accelerate cognitive decline in APP/PS1 mice.
Open Access
Amyotrophic lateral sclerosis is accompanied by protein derangements in the olfactory bulb-tract axis
(MDPI, 2020) Lachén Montes, Mercedes; Mendizuri, Naroa; Ausín, Karina; Andrés Benito, Pol; Ferrer, Isidro; Fernández Irigoyen, Joaquín; Santamaría Martínez, Enrique; Ciencias de la Salud; Osasun Zientziak; Gobierno de Navarra / Nafarroako Gobernua, Ref. 0011-1411-2020-000028
Amyotrophic lateral sclerosis (ALS) is a fatal disease characterized by progressive muscle paralysis due to the degeneration of upper and lower motor neurons. Recent studies point out an involvement of the non-motor axis during disease progression. Despite smell impairment being considered a potential non-motor finding in ALS, the pathobiochemistry at the olfactory level remains unknown. Here, we applied an olfactory quantitative proteotyping approach to analyze the magnitude of the olfactory bulb (OB) proteostatic imbalance in ALS subjects (n = 12) with respect to controls (n = 8). Around 3% of the quantified OB proteome was differentially expressed, pinpointing aberrant protein expression involved in vesicle-mediated transport, macroautophagy, axon development and gliogenesis in ALS subjects. The overproduction of olfactory marker protein (OMP) points out an imbalance in the olfactory signal transduction in ALS. Accompanying the specific overexpression of glial fibrillary acidic protein (GFAP) and Bcl-xL in the olfactory tract (OT), a tangled disruption of signaling routes was evidenced across the OB–OT axis in ALS. In particular, the OB survival signaling dynamics clearly differ between ALS and frontotemporal lobar degeneration (FTLD), two faces of TDP-43 proteinopathy. To the best of our knowledge, this is the first report on high-throughput molecular characterization of the olfactory proteostasis in ALS.
Open Access
Progressive modulation of the human olfactory bulb transcriptome during Alzheimer´s disease evolution: novel insights into the olfactory signaling across proteinopathies
(Impact Journals, 2017) Lachén Montes, Mercedes; Zelaya Huerta, María Victoria; Segura, Víctor; Fernández Irigoyen, Joaquín; Santamaría Martínez, Enrique; Ciencias de la Salud; Osasun Zientziak; Gobierno de Navarra / Nafarroako Gobernua, PC025; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Alzheimer´s disease (AD) is characterized by progressive dementia, initially presenting olfactory dysfunction. Despite the olfactory bulb (OB) is the first central structure of the olfactory pathway, we lack a complete molecular characterization of the transcriptional events that occurs in this olfactory area during AD progression. To address this gap in knowledge, we have assessed the genome-wide expression in postmortem OBs from subjects with varying degree of AD pathology. A stagedependent deregulation of specific pathways was observed, revealing transmembrane transport, and neuroinflammation as part of the functional modules that are disrupted across AD grading. Potential drivers of neurodegeneration predicted by networkdriven transcriptomics were monitored across different types of dementia, including progressive supranuclear palsy (PSP), mixed dementia, and frontotemporal lobar degeneration (FTLD). Epidermal growth factor receptor (EGFR) expression was significantly increased in the OB of AD and mixed dementia subjects. Moreover, a significant increment in the activation of signal transducer and activator of transcription 3 (STAT3) was exclusively detected in advanced AD stages, whereas total STAT3 levels were specifically overexpressed in mixed dementia. Furthermore, transcription factors deregulated in the OB of mixed dementia subjects such as cAMP Responsive Element Binding Protein 1 (CREB1) and AP-1 Transcription Factor Subunit (c-Jun) were not differentially modulated at olfactory level across AD grading. On the other hand, olfactory expression of this signal transducer panel was unchanged in PSP and FTLD subjects. Taken together, this study unveils cross-disease similarities and differences for specific signal transducers, providing mechanistic clues to the intriguing divergence of AD pathology across proteinopathies.
Open Access
Olfactory characterization and training in older adults: protocol study
(Frontiers Media, 2021) Zambom Ferraresi, Fabíola; Zambom Ferraresi, Fabrício; Fernández Irigoyen, Joaquín; Lachén Montes, Mercedes; Cartas Cejudo, Paz; Lasarte, Juan José; Casares, Noelia; Fernández, Secundino; Cedeño Veloz, Bernardo Abel; Maravi Aznar, Enrique; Uzcanga Lacabe, María Iciar; Galbete Jiménez, Arkaitz; Santamaría Martínez, Enrique; Martínez Velilla, Nicolás; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Gobierno de Navarra / Nafarroako Gobernua
The aim of this article is to present the research protocol for a prospective cohort study that will assess the olfactory function and the effect of an intervention based on olfactory training in healthy very old adults (≥75 years old). A convenience sample of 180 older people (50% female) will be recruited in three different environments: hospitalized control group (CH) with stable acute illness (n = 60); ambulatory control group (CA) of community-based living (n = 60); and an experimental odor training group (EOT) from nursing homes (n = 60). The odor training (OT) intervention will last 12 weeks. All the volunteers will be assessed at baseline; CA and EOT groups will also be assessed after 12 weeks. The primary end point will be change in olfactory capacity from baseline to 12 weeks period of intervention or control. The intervention effects will be assessed with the overall score achieved in Sniffin Sticks Test (SST) – Threshold, Discrimination, and Identification (TDI) extended version. Secondary end points will be changes in cognitive tasks, quality of life, mood, immune status, and functional capacity. All these measurements will be complemented with an immune fitness characterization and a deep proteome profiling of the olfactory epithelium (OE) cultured ex vivo. The current study will provide additional evidence to support the implementation of olfactory precision medicine and the development of immunomodulatory nasal therapies based on non-invasive procedures. The proposed intervention will also intend to increase the knowledge about the olfactory function in very elderly people, improve function and quality of life, and promote the recovery of the health.
Open Access
Impact of medication use on olfactory performance in older adults
(Frontiers Media, 2025-04-03) Izco-Cubero, Maite; Zambom Ferraresi, Fabíola; Zambom Ferraresi, Fabrício; Fernández González de la Riva, María Luisa; Santamaría Martínez, Enrique; Fernández Irigoyen, Joaquín; Lachén Montes, Mercedes; Lasarte, Juan José; Uzcanga Lacabe, María Iciar; Fernández, Secundino; Sanjurjo San Martín, Gloria; Maravi Aznar, Enrique; Martínez Velilla, Nicolás; Ciencias de la Salud; Osasun Zientziak; Gobierno de Navarra / Nafarroako Gobernua
Introduction: Olfactory dysfunction impacts quality of life, safety, and nutrition. Despite its relevance among older adults, the role of medications in influencing olfactory performance remains understudied. This research investigates whether olfactory alterations in older adults are associated with the type or number of medications prescribed. Methods: An observational cross-sectional study was conducted with 107 participants (mean age of 86.1 ± 5.1 years). Olfactory performance was evaluated using the Sniffin’ Sticks Test (SST). Functional capacity, cognitive function and the number and type of medications were also assessed. Results: The analysis demonstrated a correlation between better olfactory performance and higher cognitive function. An inverse correlation was found between the age of participants and olfactory identification. While polypharmacy (intake of five or more medications) did not show a significant association with olfactory dysfunction, the intake of laxatives was associated with poorer olfactory threshold performance (−1.21, 95% CI −2.07 to −0.34; p = 0.008). In contrast, proton pump inhibitors (PPIs) (1.14, 95% CI 0.07 to 2.21; p = 0.04) and vitamin D (1.09, 95% CI 0.03 to 2.15; p = 0.04) intake were linked to improved olfactory identification. Discussion: These findings suggest that certainmedications influence olfactory performance; however, further research is needed to clarify the effects of different drug classes on olfaction.
Open Access
Olfactory bulb neuroproteomics reveals a chronological perturbation of survival routes and a disruption of prohibitin complex during Alzheimer's disease progression
(Springer Nature, 2017) Lachén Montes, Mercedes; González Morales, Andrea; Zelaya Huerta, María Victoria; Pérez Valderrama, Estela; Ausín, Karina; Ferrer, Isidro; Fernández Irigoyen, Joaquín; Santamaría Martínez, Enrique; Ciencias de la Salud; Osasun Zientziak; Gobierno de Navarra / Nafarroako Gobernua, PC025; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Olfactory dysfunction is among the earliest features of Alzheimer’s disease (AD). Although neuropathological abnormalities have been detected in the olfactory bulb (OB), little is known about its dynamic biology. Here, OB- proteome analysis showed a stage-dependent synaptic proteostasis impairment during AD evolution. In addition to progressive modulation of tau and amyloid precursor protein (APP) interactomes, network-driven proteomics revealed an early disruption of upstream and downstream p38 MAPK pathway and a subsequent impairment of Phosphoinositide-dependent protein kinase 1 (PDK1)/Protein kinase C (PKC) signaling axis in the OB from AD subjects. Moreover, a mitochondrial imbalance was evidenced by a depletion of Prohibitin-2 (Phb2) levels and a specific decrease in the phosphorylated isoforms of Phb1 in intermediate and advanced AD stages. Interestingly, olfactory Phb subunits were also deregulated across different types of dementia. Phb2 showed a specific up-regulation in mixed dementia, while Phb1 isoforms were down-regulated in frontotemporal lobar degeneration (FTLD). However, no differences were observed in the olfactory expression of Phb subunits in progressive supranuclear palsy (PSP). To sum up, our data reflect, in part, the missing links in the biochemical understanding of olfactory dysfunction in AD, unveiling Phb complex as a differential driver of neurodegeneration at olfactory level.