Biology subjects

Vartiainen, P.

Publications and source records attributed to Vartiainen, P..

2 recordsLinked to original sources

bioRxiv2021

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↗

bioRxiv2021

An EMG-assisted Muscle-Force Driven Finite Element Analysis Pipeline to Investigate Joint- and Tissue-Level Mechanical Responses in Functional Activities: Towards a Rapid Assessment Toolbox

Joint tissue mechanics (e.g., stress and strain) are believed to have a major involvement in the onset and progression of musculoskeletal disorders, e.g., knee osteoarthritis (KOA). Accordingly, considerable efforts have been made to develop musculoskeletal finite element (MS-FE) models to estimate highly-detailed tissue mechanics that predict cartilage degeneration. However, creating such models is time-consuming and requires advanced expertise. This limits these complex, yet promising MS-FE models to research applications with few participants and making the models impractical for clinical assessments. Also, these previously developed MS-FE models are not assessed for any activities other than the gait. This study introduces and validates a semi-automated rapid state-of-the-art MS-FE modeling and simulation toolbox incorporating an electromyography (EMG) assisted MS model and a muscle-force driven FE model of the knee with fibril-reinforced poro(visco)elastic cartilages and menisci. To showcase the usability of the pipeline, we estimated joint- and tissue-level knee mechanics in 15 KOA individuals performing different daily activities. The pipeline was validated by comparing the estimated muscle activations and joint mechanics to existing experimental data. Also, to examine the importance of EMG-assisted MS analyses, results were compared against outputs from the same FE models but driven by static-optimization-based MS models. The EMG-assisted MS-FE pipeline bore a closer resemblance to experiments, compared to the static-optimization-based MS-FE pipeline. More importantly, the developed pipeline showed great potentials as a rapid MS-FE analysis toolbox to investigate multiscale knee mechanics during different activities of individuals with KOA.

biophysics↗