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
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
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
Smelling the dark proteome: functional characterization of PITH domain-containing protein 1 (C1orf128) in olfactory metabolism
(American Chemical Society, 2020) Lachén Montes, Mercedes; Mendizuri, Naroa; Ausín, Karina; Pérez Mediavilla, Alberto; Azkargorta, Mikel; Fernández Irigoyen, Joaquín; Santamaría Martínez, Enrique; Iloro, Ibon; Elortza, Félix; Kondo, Hiroyuki; Ohigashi, Izumi; Ferrer, Isidro; Torre, Rafael de la; Robledo, Patricia; Ciencias de la Salud; Osasun Zientziak; Gobierno de Navarra / Nafarroako Gobernua; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The Human Proteome Project (HPP) consortium aims to functionally characterize the dark proteome. On the basis of the relevance of olfaction in early neurodegeneration, we have analyzed the dark proteome using data mining in public resources and omics data sets derived from the human olfactory system. Multiple dark proteins localize at synaptic terminals and may be involved in amyloidopathies such as Alzheimer's disease (AD). We have characterized the dark PITH domain-containing protein 1 (PITHD1) in olfactory metabolism using bioinformatics, proteomics, in vitro and in vivo studies, and neuropathology. PITHD1-/- mice exhibit olfactory bulb (OB) proteome changes related to synaptic transmission, cognition, and memory. OB PITHD1 expression increases with age in wild-type (WT) mice and decreases in Tg2576 AD mice at late stages. The analysis across 6 neurological disorders reveals that olfactory tract (OT) PITHD1 is specifically upregulated in human AD. Stimulation of olfactory neuroepithelial (ON) cells with PITHD1 alters the ON phosphoproteome, modifies the proliferation rate, and induces a pro-inflammatory phenotype. This workflow applied by the Spanish C-HPP and Human Brain Proteome Project (HBPP) teams across the ON-OB-OT axis can be adapted as a guidance to decipher functional features of dark proteins. Data are available via ProteomeXchange with identifiers PXD018784 and PXD021634.
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.
Open Access
Sex-divergent effects on the NAD+-dependent deacetylase sirtuin signaling across the olfactory-entorhinal-amygdaloid axis in Alzheimer's and Parkinson's diseases
(BMC, 2023) Cartas Cejudo, Paz; Lachén Montes, Mercedes; Ferrer, Isidro; Fernández Irigoyen, Joaquín; Santamaría Martínez, Enrique; Ciencias de la Salud; Osasun Zientziak
Background Smell impairment is one of the earliest features in Alzheimer’s (AD) and Parkinson’s diseases (PD). Due to sex diferences exist in terms of smell and olfactory structures as well as in the prevalence and manifestation of both neurological syndromes, we have applied olfactory proteomics to favor the discovery of novel sex-biased physio-pathological mechanisms and potential therapeutic targets associated with olfactory dysfunction. Methods SWATH-MS (sequential window acquisition of all theoretical fragment ion spectra mass spectrometry) and bioinformatic workfows were applied in 57 post-mortem olfactory tracts (OT) derived from controls with no known neurological history (n=6F/11M), AD (n=4F/13M) and PD (n=7F/16M) subjects. Complementary molecular analyses by Western-blotting were performed in the olfactory bulb (OB), entorhinal cortex (EC) and amygdala areas. Results 327 and 151 OT diferentially expressed proteins (DEPs) were observed in AD women and AD men, respec‑ tively (35 DEPs in common). With respect to PD, 198 DEPs were identifed in PD women, whereas 95 DEPs were detected in PD men (20 DEPs in common). This proteome dyshomeostasis induced a disruption in OT protein interac‑ tion networks and widespread sex-dependent pathway perturbations in a disease-specifc manner, among them Sirtuin (SIRT) signaling. SIRT1, SIRT2, SIRT3 and SIRT5 protein levels unveiled a tangled expression profle across the olfactory–entorhinal–amygdaloid axis, evidencing disease-, sex- and brain structure-dependent changes in olfactory protein acetylation. Conclusions Alteration in the OT proteostasis was more severe in AD than in PD. Moreover, protein expression changes were more abundant in women than men independent of the neurological syndrome. Mechanistically, the tangled SIRT profle observed across the olfactory pathway-associated brain regions in AD and PD indicates difer‑ ential NAD (+)-dependent deacetylase mechanisms between women and men. All these data shed new light on diferential olfactory mechanisms across AD and PD, pointing out that the evaluation of the feasibility of emerging sirtuin-based therapies against neurodegenerative diseases should be considered with caution, including further sex dimension analyses in vivo and in clinical studies.
Open Access
Deregulated transcription and proteostasis in adult mapt knockout mouse
(MDPI, 2023) Andrés Benito, Pol; Flores, África; Busquet-Areny, Sara; Carmona, Margarita; Ausín, Karina; Cartas Cejudo, Paz; Lachén Montes, Mercedes; Río, José Antonio del; Fernández Irigoyen, Joaquín; Santamaría Martínez, Enrique; Ferrer, Isidro; Ciencias de la Salud; Osasun Zientziak
Transcriptomics and phosphoproteomics were carried out in the cerebral cortex of B6.Cg-Mapttm1(EGFP)Klt (tau knockout: tau-KO) and wild-type (WT) 12 month-old mice to learn about the effects of tau ablation. Compared with WT mice, tau-KO mice displayed reduced anxiety-like behavior and lower fear expression induced by aversive conditioning, whereas recognition memory remained unaltered. Cortical transcriptomic analysis revealed 69 downregulated and 105 upregulated genes in tau-KO mice, corresponding to synaptic structures, neuron cytoskeleton and transport, and extracellular matrix components. RT-qPCR validated increased mRNA levels of col6a4, gabrq, gad1, grm5, grip2, map2, rab8a, tubb3, wnt16, and an absence of map1a in tau-KO mice compared with WT mice. A few proteins were assessed with Western blotting to compare mRNA expression with corresponding protein levels. Map1a mRNA and protein levels decreased. However, ¿-tubulin III and GAD1 protein levels were reduced in tau-KO mice. Cortical phosphoproteomics revealed 121 hypophosphorylated and 98 hyperphosphorylated proteins in tau-KO mice. Deregulated phosphoproteins were categorized into cytoskeletal (n = 45) and membrane proteins, including proteins of the synapses and vesicles, myelin proteins, and proteins linked to membrane transport and ion channels (n = 84), proteins related to DNA and RNA metabolism (n = 36), proteins connected to the ubiquitin-proteasome system (UPS) (n = 7), proteins with kinase or phosphatase activity (n = 21), and 22 other proteins related to variegated pathways such as metabolic pathways, growth factors, or mitochondrial function or structure. The present observations reveal a complex altered brain transcriptome and phosphoproteome in tau-KO mice with only mild behavioral alterations.