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Pedersen, S. L.

Publications and source records attributed to Pedersen, S. L..

3 recordsLinked to original sources

The SorCS2-derived macrocycle TT-P34 drives neuroprotection in animal models of neurodegeneration

Mitochondria are critical for sustaining the high energy demands of neuronal activity and their dysregulation is a hallmark of neurodegeneration. Targeting pathways of neurotrophic signaling is a well-established therapeutic strategy to enhance mitochondrial function and mitigate neurodegeneration. The VPS10p domain receptor, SorCS2, has recently emerged as a receptor with neurotrophic signaling capabilities. Here, we design and develop novel SorCS2-derived macrocyclic peptides mimicking receptor activation in vivo. We show that SorCS2-peptides enhance both neurotrophic support and boost metabolism by activating CREB and AMPK in a CAMKK2-dependent manner. This leads to upregulation of the key transcription factors PGC1 and TFEB and consequentially mitochondrial biogenesis. Furthermore, we show that the lipidated SorCS2 macrocycle, TT-P34, rescues motor behavioral deficits and preserves synaptic and mitochondrial signatures in the zQ175 mouse model of Huntingtons Disease. In addition, treating a MPTP-induced mouse model of Parkinsons Disease leads to amelioration of behavioral deficits and reduction of dopaminergic loss. Finally, we demonstrate that TT-P34 crosses the blood-brain barrier in non-human primates, and estimate human therapeutic dosing by pharmacodynamic modelling. Together, our findings support the use of TT-P34 as a novel disease-modifying therapy targeting SorCS2-receptor signaling to prevent neurodegeneration.

neuroscience↗

The hepcidin-ferroportin axis influences mitochondrial function, proliferation, and migration in pulmonary artery endothelial and smooth muscle cells

RationaleElevated circulating hepcidin levels have been reported in patients with pulmonary artery hypertension (PAH). Hepcidin has been shown to promote proliferation of human pulmonary artery smooth muscle cells (PASMCs) in vitro, suggesting a potential role in PAH pathogenesis. However, the role of human pulmonary artery endothelial cells (PAECs) as either a source of hepcidin, or the effect of hepcidin on PAECfunction has not previously been described. ObjectiveTo define the role of the hepcidin-ferroportin axis on the phenotype of pulmonary artery endothelial cells Methods and resultsPAECs treated with hepcidin, or IL-6 were investigated for both ferroportin and hepcidin release and regulation with immunofluorescence, mRNA levels and cellular release assays. Effects of hepcidin on PASMC and PAEC mitochondrial function was investigated using immunofluorescence and seahorse assay. Migration and proliferation of PASMC treated with conditioned media from hPAEC treated with hepcidin was investigated using the Xcelligence system and other tools. PAECs express ferroportin; hepcidin treatment of PAECs results in mitochondrial iron accumulation and intracellular hepcidin biosynthesis and release. Conditioned media from hepcidin treated PAECs causes PASMCs to down regulate ferroportin expression whilst promoting migration and proliferation. Inhibition of hepcidin in PAEC conditioned media limits these responses. PASMC cellular and mitochondrial iron retention are associated with migratory and proliferative responses. ConclusionsThe Hepcidin-ferroportin axis is present and operational in PAECs. Modulation of this axis shows distinct differences in responses seen between PAECS and PASMCs. Stimulation of this axis in PAECS with hepcidin may well institute proliferative and migratory responses in PASMCs of relevance to pathogenesis of PAH offering a potential therapeutic target.

cell biology↗

Using eDNA to biomonitor the fish community in a tropical oligotrophic lake

Environmental DNA (eDNA) is an effective approach for detecting vertebrates and plants, especially in aquatic ecosystems, but prior studies have largely examined eDNA in cool temperate settings. By contrast, this study employs eDNA to survey the fish fauna in tropical Lake Bacalar (Mexico) with the additional goal of assessing the possible presence of invasive fishes, such as Amazon sailfin catfish. Sediment and water samples were collected from eight stations in Lake Bacalar on three occasions over a 4-month interval. Each sample was stored in the presence or absence of lysis buffer to compare eDNA recovery. Short fragments (184-187 bp) of the cytochrome c oxidase I (COI) gene were amplified using fusion primers and then sequenced on Ion Torrent PGM and S5 before their source species were determined using a custom reference sequence database constructed on BOLD. In total, eDNA sequences were recovered from 75 species of vertebrates including 47 fishes, 15 birds, 7 mammals, 5 reptiles, and 1 amphibian. Although all species are known from this region, 6 fish species represent new records for the study area, while 2 require verification. Sequences for five species (2 birds, 2 mammals, 1 reptile) were only detected from sediments, while sequences from 52 species were only recovered from water. Because DNA from the Amazon sailfin catfish was not detected, we used a mock eDNA experiment to confirm our methods were appropriate for its detection. We developed protocols that enabled the recovery of eDNA from tropical oligotrophic aquatic ecosystems, and confirmed their effectiveness in detecting diverse species of vertebrates including an invasive species of Amazon catfish.

molecular biology↗