Hyperstable EGF-like bleogen derived from cactus accelerates corneal healing in rats

Abstract

Corneal scarring reduces corneal transparency, compromises vision, and is a major cause of vision loss worldwide. Epidermal growth factor (EGF), which is the prototypic member of the EGF receptor (EGFR) agonists, is present in tears to provide repair and regeneration. Recently, we discovered bleogen pB1 in the cactus plant Pereskia bleo and showed that it is a non-canonical and hyperstable EGFR agonist with EGF-like wound healing properties for diabetic rats. Here, we apply bleogen pB1 to accelerate corneal wound healing in rats. To assess the corneal healing effects of bleogen pB1, we induced an acute alkali burn to the right eye of male Wistar rats. After five consecutive ophthalmic applications, fluorescein staining and opacity scores of the bleogen pB1-treated, and the positive control EGF-treated groups improved significantly compared to the saline control group. Immunohistochemical analyses revealed that infiltrated CD68+ macrophages and the expression of the myofibroblast marker alpha smooth muscle actin (α-SMA) were significantly decreased in the bleogen pB1- and the EGF-treated groups. By employing a differential gene expression analysis of bleogen pB1- and EGF-treated keratinocytes through RNA-seq, we demonstrated that bleogen pB1 or EGF treatments can affect the expression of genes associated with inflammatory responses and extracellular matrix remodeling. Taken together, our results indicate that the plant-derived EGFR agonist bleogen pB1 can produce similar effects to those of EGF in accelerating corneal wound healing as well as in reducing persistent inflammation and myofibroblast accumulation in the cornea.

Ultrafast Biomimetic Oxidative Folding of Cysteine‐rich Peptides and Microproteins in Organic Solvents

“… Effects of redox reagents, peptide to redox reagent ratio, and peptide concentration in the organic oxidative folding reaction of bleogen pB1: (A) HPLC profiles of the organic oxidative folding of bleogen pB1 (Seq: ZCKPNGAKCTEISIPPCCSNFCLRYAGQKSGTCANR) [4d,5c,16] with or without reducing cysteamine/oxidizing cystamine. Reaction condition of organic oxidative folding: 90 % morpholine, 10 % DMSO, and S‐reduced‐peptide: cysteamine: cystamine (1 : 100 : 10, mol/mol) at 4 °C.…”

“…Examples include venom toxins, antimicrobial peptides, and hevein‐like peptides, many of which were first isolated from medicinal plants and then chemically synthesized in our laboratory. The selected panel included seven six‐cysteine CRPs (bleogen pB1, [4d,5c,16] roseltide rT1, [4a,c] roseltide rT7, [4b] alstotide aS1, [17] linaclotide, [18] ziconotide, [19] and bovine pancreatic trypsin inhibitor (BPTI), [20] two cyclic CRPs (kalata B1 and B2, [15,21] one eight‐cysteine CRPs (lybatide 1), [22] and one ten‐cysteine CRP (EAFP1 from Eucommia antifungal peptide) [23] . Linaclotide and ziconotide are examples of FDA‐approved therapeutic CRPs, for the treatment of irritable bowel disease and chronic pain, respectively.…”

Ultrafast Biomimetic Oxidative Folding of Cysteine‐rich Peptides and Microproteins in Organic Solvents

“… Rate vs percentage of various organic bases in organic the oxidative folding of bleogen pB1 and kalata B1. The rates of organic oxidative folding of (A) bleogen pB1 (Seq: 9) [4d,5c,16] or (B) kalata B1 (Seq: cyclic [GLPVCGETCVGGTCNTPGCTCSWPVCTRN]) [9a,15] were determined using binary mixtures of increasing concentrations of morpholine (pKa 8.5) or 1‐methylimidazole (pKa 7.1) in pyridine (pKa 5.2). The reaction rates in pyridine were too slow (t=>24 h) to monitor directly but could be extrapolated using 90 % pyridine and 10 % DMSO.…”

Broad-spectrum ginsentides are principal bioactives in unraveling the cure-all effects of ginseng

“…Guided by traditional medicines, we have identified orally-active disulfide-rich peptides or microproteins from medicinal plants. These microproteins, with 6–10 cysteine residues and a molecular weight of 2–4 kDa, are bioactives that show potential as therapeutic leads for cardiovascular diseases, stress, frailty, and other chronic and age-related diseases 16 , 17 , 29 , 39 , 66 . Previously, we identified ginsentides as a group of plant-derived peptides or microproteins found in different ginseng species 18 .…”