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Hornigold, D.

Publications and source records attributed to Hornigold, D..

2 recordsLinked to original sources

Reversible peptide self-assembly enables sustained drug delivery with tuneable pharmacokinetics

Therapeutic peptides combine high target specificity with potent biological activity.1 However, treatment success is often limited by rapid clearance and the need for frequent injections.2, 3 This challenge is particularly acute for therapeutic peptides used in obesity, where clinical benefit must be balanced against dose-dependent adverse effects. In nature, these constraints are overcome by storing hormones as reversible fibrils,4 but pharmacokinetic control is essential for widespread adoption of bio-inspired self-assembled depots for therapeutic peptides. Here, we show that tuneable pharmacokinetics can be achieved and modelled by mapping the fundamental chemical parameters of reversibly self-assembly in vitro. We demonstrate this approach for the amylin analogue pramlintide. Amylin analogues are under development for the next generation of diabetes and obesity treatments, with improved mechanism of action e.g. preserving lean body mass.5-8 Pramlintide is an approved drug with a well-established safety profile, however, it has a comparable half-life to native amylin.8-12 In a pilot study, we achieve in vitro-in vivo correlation, increasing the half-life of pramlintide 20-82-fold in rats, while controlling burst release. These findings demonstrate that the optimisation of pharmacokinetics can be decoupled from peptide engineering, establishing a generalisable framework for generating long-acting peptide formulations by emulating native storage mechanisms.

biophysics↗

Relaxin/insulin-like family peptide receptor 4 (Rxfp4) expressing hypothalamic neurons modulate food intake and preference in mice

Relaxin/insulin-like-family peptide receptor-4 (RXFP4), the cognate receptor for insulin-like peptide 5 (INSL5), has been implicated in feeding behaviour as Rxfp4 knockout mice display shorter meal durations and reduced high fat diet (HFD) intake. Here, we generated transgenic Rxfp4-Cre mice to explore Rxfp4 expression and physiology. Using this model, we identified Rxfp4 expression in the central nervous system, including in the ventromedial hypothalamus (VMH). Intra-VMH infusion of INSL5 increased HFD and highly palatable liquid meal intake (HPM) of ad libitum fed wildtype mice. Single-cell RNA-sequencing of VMH Rxfp4-expressing cells (RXFP4VMH) defined a cluster of Rxfp4-labelled neurons expressing Esr1, Tac1 and Oxtr, alongside known appetite-modulating neuropeptide receptors (Mc4r, Cckar and Nmur2). Viral tracing demonstrated RXFP4VMH neural projections to the bed nucleus of the stria terminalis, paraventricular hypothalamus, paraventricular thalamus and central nucleus of the amygdala. Utilising designer receptors exclusively activated by designer drugs (DREADDs), we found that whole body chemogenetic inhibition (Di) of Rxfp4-expressing cells, mimicking native INSL5-RXFP4 signalling, increased intake of HFD and HPM, whilst activation (Dq), either at whole body level or specifically within the VMH, reduced HFD and HPM intake and altered food preference. Ablating VMH Rxfp4-expressing cells recapitulated the lower HFD intake phenotype of Rxfp4 knockout mice, resulting in reduced body weight. These findings identify a discrete Rxfp4-expressing neuronal population as a key regulator of food intake and preference and reveal hypothalamic RXFP4 signalling as a target for feeding behaviour manipulation.

physiology↗