Oral delivery of novel human IGF-1 bioencapsulated in lettuce cells promotes musculoskeletal cell proliferation, differentiation and diabetic fracture healing

Abstract

Human insulin-like growth factor-1 (IGF-1) plays important roles in development and regeneration of skeletal muscles and bones but requires daily injections or surgical implantation. Current clinical IGF-1 lacks e-peptide and is glycosylated, reducing functional efficacy. In this study, codon-optimized Pro-IGF-1 with e-peptide (fused to GM1 receptor binding protein CTB or cell penetrating peptide PTD) was expressed in lettuce chloroplasts to facilitate oral delivery. Pro-IGF-1 was expressed at high levels in the absence of the antibiotic resistance gene in lettuce chloroplasts and was maintained in subsequent generations. In lyophilized plant cells, Pro-IGF-1 maintained folding, assembly, stability and functionality up to 31 months, when stored at ambient temperature. CTB-Pro-IGF-1 stimulated proliferation of human oral keratinocytes, gingiva-derived mesenchymal stromal cells and mouse osteoblasts in a dose-dependent manner and promoted osteoblast differentiation through upregulation of ALP, OSX and RUNX2 genes. Mice orally gavaged with the lyophilized plant cells significantly increased IGF-1 levels in sera, skeletal muscles and was stable for several hours. When bioencapsulated CTB-Pro-IGF-1 was gavaged to femoral fractured diabetic mice, bone regeneration was significantly promoted with increase in bone volume, density and area. This novel delivery system should increase affordability and patient compliance, especially for treatment of musculoskeletal diseases.

Green giant—a tiny chloroplast genome with mighty power to produce high‐value proteins: history and phylogeny

“…Codon optimised expression of angiotensin‐converting enzyme 2 not only helped to treat pulmonary hypertension, but has also now been tested in the clinic to treat COVID‐19 patients (Daniell, 2020), as discussed in depth below. Codon‐optimized expression of a novel human insulin‐like growth factor in lettuce chloroplasts promoted musculoskeletal cell proliferation, differentiation and diabetic bone fracture healing (Park et al ., 2020). The expression level of enzymes in chloroplasts and the efficacy exceeded current products made in fermentation systems using almost all evaluation criteria, without any need for purification (Daniell et al ., 2019c; Kumari et al ., 2019).…”

Heat stress alters muscle protein and amino acid metabolism and accelerates liver gluconeogenesis for energy supply in broilers

“…Insulin-like growth factor-1 ( IGF-1 ) has pleiotropic effects including the regulation of body growth and mediation of the energy metabolism ( Park et al., 2020 ; Riis et al., 2020 ). The level of circulating IGF-1 possesses a positive regulation on body growth achieved by binding IGF-1 receptor ( IGF-1R ) and activating its downstream signaling pathway ( Elis et al., 2010 ; François et al., 2017 ).…”

From conception to COVID‐19: an arduous journey of tribulations of racism and triumphs

“…The plant cell wall efficiently protects vaccine antigens from digestive enzymes and acidic pH, and gut microbes digest plant cell walls to release antigens in the gut lumen. Recent advances include expression of human blood proteins after codon optimization (Kwon et al , 2016, 2018) in marker‐free lettuce plants, stability of expression in the absence of antibiotic resistance genes and functional efficacy in animal disease models (Daniell et al , 2020; Park et al , 2020). In addition to raising the profile of plant biology in the medical field by featuring plant research on covers of medical journals or on featured editorials, these projects received funding from Bayer, Novo Nordisk, Shire, Takeda and NIH SMARTT program to produce clinical grade materials, conduct third party toxicology/pharmacokinetic/regulatory studies at Stanford Research Institute and results of these studies have been published recently (Daniell et al , 2020; Herzog et al , 2017).…”