Orford, M. | Search bioRxiv

bioRxiv2020

Beclin-1-mediated activation of autophagy improves proximal and distal urea cycle disorders.

Urea cycle disorders (UCD) are inherited defects in clearance of waste nitrogen with high morbidity and mortality. Novel and more effective therapies for UCD are needed. Studies in mice with constitutive activation of autophagy unraveled Beclin-1 as druggable candidate for therapy of hyperammonemia. Next, we investigated efficacy of cell penetrating autophagy inducing Tat-Beclin-1 (TB-1) peptide for therapy of the two most common UCD, namely ornithine transcarbamylase (OTC) and argininosuccinate lyase (ASL) deficiencies. TB-1 reduced urinary orotic acid and hyperammonemia, and improved survival under protein-rich diet in spf-ash mice, a model of OTC deficiency (proximal UCD). In AslNeo/Neo mice, a model of ASL deficiency (distal UCD), TB-1 increased ureagenesis, reduced argininosuccinate, and improved survival. Moreover, it alleviated hepatocellular injury and decreased both cytoplasmic and nuclear glycogen accumulation in AslNeo/Neo mice. In conclusion, Beclin-1-dependent activation of autophagy improved biochemical and clinical phenotypes of proximal and distal defects of the urea cycle.

genetics↗

bioRxiv2019

Engineering transplantable jejunal mucosal grafts using primary patient-derived organoids from children with intestinal failure

Intestinal failure (IF), following extensive anatomical or functional loss of small intestine (SI), has debilitating long-term effects on infants and children with this condition. Priority of care is to increase the childs length of functional intestine, jejunum in particular, to improve nutritional independence. Here we report a robust protocol for reconstruction of autologous intestinal mucosal grafts using primary IF patient materials. Human jejunal intestinal organoids derived from paediatric IF patients can be expanded efficiently in vitro with region-specific markers preserved after long-term culture. Decellularized human intestinal matrix with intact ultrastructure is used as biological scaffolds. Proteomic and Raman spectroscopic analyses reveal highly analogous biochemical composition of decellularized human SI and colon matrix, implying that they can both be utilised as scaffolds for jejunal graft reconstruction. Indeed, seeding of primary human jejunal organoids to either SI or colonic scaffolds in vitro can efficiently reconstruct functional jejunal grafts with persistent disaccharidase activity as early as 4 days after seeding, which can further survive and mature after transplantation in vivo. Our findings pave the way towards regenerative medicine for IF patients.

bioengineering↗