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Kanninen, K. M.

Publications and source records attributed to Kanninen, K. M..

6 recordsLinked to original sources

Alzheimer's Disease-Associated Proteomic Changes in Olfactory Stem Cells Show Pathway-Level Transcriptomic Overlap

Alzheimer's disease (AD) is a progressive, neurodegenerative disorder and the leading cause of dementia worldwide. Although recent therapeutic advances have provided some disease-modifying potential, there is currently no curative treatment for AD, highlighting the need for improved disease models and early biomarkers. Olfactory mucosal stem cells, which can be expanded in vitro as olfactory neurosphere-derived (ONS) cells, represent a promising source for biomarker discovery because olfactory tissue is more accessible than central nervous system tissue and has been reported to exhibit AD-related pathological changes. In this study, we used subcellular fractionation-based proteomics, reconstructed bulk proteomics and integrated transcriptomic-proteomic analyses to characterise alterations in ONS cells derived from healthy control, mild cognitive impairment (MCI) and AD individuals. Fraction-specific proteomics identified cytoplasmic and nuclear-enriched protein abundance changes, including alterations in proteins and pathways associated with cytoskeletal organisation, RNA processing, intracellular trafficking, autophagy and mitochondrial/metabolic processes. Reduced LC3B abundance in cytoplasmic AD ONS cells was supported by western blot analysis, although LC3B abundance alone does not indicate altered autophagic flux. Reconstructed bulk proteomics identified 40 FDR-significant proteins in AD compared with HC, defining an AD-associated protein signature enriched for extracellular matrix, cytoskeletal, organelle-associated and RNA-processing pathways. Despite proteomic enrichment of mitochondrial and metabolic pathways, Seahorse Mito Stress Test analysis did not identify significant group-level differences in mitochondrial respiration. Integrated transcriptomic-proteomic analysis revealed partial RNA-protein concordance and pathway-level overlap across disease-associated processes. Together, these findings support the use of patient-derived ONS cells as a model for investigating AD- and MCI-associated molecular changes and highlight protein signatures for further validation.

neuroscience↗

Proteomic insights into mental health status: plasma markers in young adults

Global emphasis on enhancing prevention and treatment strategies necessitates increased understanding of biological mechanisms of psychopathology. Plasma proteomics is a powerful tool that has been applied in the context of specific mental disorders for biomarker identification. The p-factor, also known as the "general psychopathology factor", is a concept in psychopathology suggesting that there is a common underlying factor that contributes to the development of various forms of mental disorders. It has been proposed that the p-factor can be used to understand the overall mental health status of an individual. Here we aimed to discover plasma proteins associated with the p-factor in 775 young adults in the FinnTwin12 cohort. Using liquid chromatography-tandem mass spectrometry, 14 proteins with a significant connection with the p-factor were identified, 9 of which were linked to epidermal growth factor receptor (EGFR) signalling. This exploratory study provides new insight into biological alterations associated with mental health status in young adults.

neuroscience↗

An Alzheimer's disease patient-derived olfactory cell model identifies gene expression changes associated with cognition

An early symptom of Alzheimers disease (AD) is an impaired sense of smell, for which the molecular basis remains elusive. Here, we generated human olfactory neurosphere-derived (ONS) cells from people with AD and mild cognitive impairment (MCI), and performed global RNA sequencing to determine gene expression changes. ONS cells expressed markers of neuroglial differentiation, providing a unique cellular model to explore early AD-associated disease pathways. Our transcriptomics data from ONS cells revealed differentially expressed genes (DEGs) associated with cognitive processes in AD cells compared to MCI, or matched healthy controls (HC). A-Kinase Anchoring Protein 6 (AKAP6) was the most significantly altered gene in AD compared to both MCI and HC, and has been linked to cognitive function. The greatest change in gene expression of all DEGs occurred between AD and MCI. Gene pathway analysis revealed defects in multiple cellular processes with aging, intellectual deficiency and alternative splicing being the most significantly dysregulated in AD ONS cells. Our results demonstrate that ONS cells can provide a cellular model for AD that recapitulates disease-associated differences. We have revealed potential novel genes, including AKAP6 that may have a role in AD, particularly MCI to AD transition, and should be further examined.

neuroscience↗

Alzheimer's disease alters astrocytic functions related to neuronal support andtranscellular internalization of mitochondria

Under physiological conditions in vivo astrocytes internalize and degrade neuronal mitochondria in a process called transmitophagy. Mitophagy is widely reported to be impaired in neurodegeneration but it is unknown whether and how transmitophagy is altered in Alzheimers disease (AD). Here we report that the internalization and degradation of neuronal mitochondria are significantly increased in astrocytes isolated from aged AD mouse brains. We also demonstrate for the first time a similar phenomenon between human neurons and AD astrocytes, and in murine hippocampi in vivo. The results suggest the involvement of S100a4 in impaired mitochondrial transfer between neurons and aged AD astrocytes. Significant increases in the mitophagy regulator Ambra1 were observed in the aged AD astrocytes. These findings demonstrate altered neuron-supporting functions of aged AD astrocytes and provide a starting point for studying the molecular mechanisms of transmitophagy in AD.

neuroscience↗

Subacute Inhalation of Ultrafine Particulate Matter Triggers Inflammation Without Altering Amyloid Beta Load in 5xFAD mice.

Epidemiological studies reveal that air pollution exposure may exacerbate neurodegeneration. Ultrafine particles (UFPs) are pollutants that remain unregulated in ambient air by environmental agencies. Due to their small size (<100nm), UFPs have the most potential to cross the bodily barriers and thus impact the brain. However, little information exists about how UFPs affect brain function. Alzheimers disease (AD) is the most common form of dementia, which has been linked to air pollutant exposure, yet limited information is available on the mechanistic connection between them. This study aims to decipher the effects of UFPs in the brain and periphery using the 5xFAD mouse model of AD. In our study design, AD mice and their wildtype littermates were subjected to 2-weeks inhalation exposure of UFPs in a whole-body chamber. That subacute exposure did not affect the blood-brain barrier integrity or amyloid-beta accumulation. However, when multiple cytokines were analyzed, we found increased levels of proinflammatory cytokines in the brain and periphery, with a predominant alteration of interferon-gamma in response to UFP exposure in both genotypes. Following exposure, mitochondrial superoxide dismutase was significantly upregulated only in the 5xFAD hippocampi, depicting oxidative stress induction in the exposed AD mouse group. These data demonstrate that short-term exposure to inhaled UFPs induces inflammation without affecting amyloid-beta load. This study provides a better understanding of adverse effects caused by short-term UFP exposure in the brain and periphery, also in the context of AD. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=138 SRC="FIGDIR/small/459017v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@479511org.highwire.dtl.DTLVardef@18bc59aorg.highwire.dtl.DTLVardef@15a0240org.highwire.dtl.DTLVardef@49f911_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

Disease specific alterations in the olfactory mucosa of patients with Alzheimer's disease

Olfactory dysfunction manifests early in several neurodegenerative disorders. Olfaction is orchestrated by olfactory mucosal cells located in the upper nasal cavity. However, it is unclear how this tissue reflects key neurodegenerative features in Alzheimers disease. Here we report that Alzheimers disease olfactory mucosal cells obtained from live individuals secrete toxic amyloid-beta. We detail cell-type-specific gene expression patterns, unveiling 147 differentially expressed disease-associated genes compared to the cognitively healthy controls, and 5 distinct populations in globose basal cell -, myofibroblast-, and fibroblast/ stromal - like cells in vitro. Overall, coordinated alteration of RNA and protein metabolism, inflammatory processes and signal transduction were observed in multiple cell populations, suggesting a key role in pathophysiology. Our results demonstrate the potential of olfactory cell cultures in modelling Alzheimers disease advocate their use for diagnostic purposes. Moreover, for the first time we provide single cell data on olfactory mucosa in Alzheimers disease for investigating molecular and cellular mechanisms associated with the disease.

neuroscience↗