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Sorensen, K. K.

Publications and source records attributed to Sorensen, K. K..

3 recordsLinked to original sources

Long-term 2D monoculture of primary mouse LSEC preserves scavenging capacity and enables siRNA knockdown of Mrc1

Liver sinusoidal endothelial cells (LSEC) rapidly dedifferentiate in 2D-monoculture, losing their high endocytic activity and characteristic morphology, limiting their use in mechanistic studies. We established and validated culture conditions that preserve LSEC endocytic capacity for at least 10 days, enabling efficient in vitro siRNA-mediated gene silencing. Mouse LSEC were cultured in 5% oxygen, growth media partially exchanged daily and assessed for cell viability, endocytic capacity, morphology and ultrastructure. Despite typical culture-induced defenestration, the cells showed high viability and efficient endocytosis via scavenger-receptors. This allowed for siRNA-mediated mannose receptor knockdown exemplified by 96% and 76% reduction in Mrc1 mRNA and protein expression at 72h (validated by qPCR and Western blot), with functional assays confirming decreased mannose-receptor-mediated endocytosis. Extended maintenance of LSEC viability and functions, previously restricted to complex co-culture systems, provide a practical platform for investigating LSEC-specific molecular mechanisms and hepatic sinusoid physiology.

cell biology↗

Venom-inspired somatostatin receptor 4 (SSTR4) agonists as new drug leads for peripheral pain conditions

Persistent pain affects one in five people worldwide, often with severely debilitating consequences. Current treatment options, which can be effective for mild or acute pain, are ill-suited for moderate-to-severe persistent pain, resulting in an urgent need for new therapeutics. In recent years, the somatostatin receptor 4 (SSTR4), which is expressed in sensory neurons of the peripheral nervous system, has emerged as a promising target for pain relief. However, the presence of several closely related receptors with similar ligand-binding surfaces complicates the design of receptor-specific agonists. In this study, we report the discovery of a potent and selective SSTR4 peptide, consomatin Fj1, derived from extensive venom gene datasets from marine cone snails. Consomatin Fj1 is a mimetic of the endogenous hormone somatostatin and contains a minimized binding motif that provides stability and drives peptide selectivity. Peripheral administration of synthetic consomatin Fj1 provided analgesia in mouse models of postoperative and neuropathic pain. Using structure-activity studies, we designed and functionally evaluated several Fj1 analogs, resulting in compounds with improved potency and selectivity. Our findings present a novel avenue for addressing persistent pain through the design of venom-inspired SSTR4-selective pain therapeutics. One Sentence SummaryVenom peptides from predatory marine mollusks provide new leads for treating peripheral pain conditions through a non-opioid target.

pharmacology and toxicology↗

SorCS2 binds progranulin and regulates motor axon outgrowth

Motor neuron development requires an orchestrated action of trophic factors and guidance cues for axons to reach their targets. Here, we identify SorCS2 as a novel receptor for progranulin (PGRN) that is required for motor axon outgrowth in zebrafish and mice. In both species motor neurons express SorCS2, and PGRN is produced in cells juxta-positioned the projecting axon, but in mice the neurons also co-express PGRN. In zebrafish, sorcs2 knockdown produces stunted and aberrantly branched motor axons, and in Sorcs2-/- mice, forelimb innervation and motor neuron regeneration are substantially perturbed; phenotypes also observed in fish and mice lacking PGRN. SorCS2 binds PGRN and while motor neuron cultures from wildtype mice respond to exogenous PGRN by axon outgrowth, knockout neurons are unresponsive. Remarkably, when co-expressed in the same cells, SorCS2 controls secretion of PGRN. We conclude that SorCS2 navigates motor neuron development and enables axon regeneration through binding of PGRN.

developmental biology↗