Critical effects on binding of epidermal growth factor produced by amino acid substitutions

Dietary Supplementation of EGF Ameliorates the Negatively Effects of LPS on Early-Weaning Piglets: From Views of Growth Performance, Nutrient Digestibility, Microelement Absorption and Possible Mechanisms

Simple Summary

This study aims to investigate how epidermal growth factor (EGF) attenuates the effect of lipopolysaccharide (LPS) on the growth performance, nutrient digestibility, microelement absorption of early-weaned pigs. A total of 48 early weaned piglets were randomly distributed to four groups consisting of a 2 × 2 factorial design. The main factors were the level of LPS (H_LPS = high LPS: 100 μg/kg body weight; Z_LPS = low LPS: 0 μg/kg body weight) and EGF (H_EGF = high EGF: 2 mg/kg diet; Z_EGF = low EGF: 0 mg/kg diet). Each group had four replicates and each replicate consisted of three piglets. The results showed that H_LPS level decreased the growth performance and the apparent digestibility of crude fat, while H_EGF level increased the average daily feed intake. The concentration of most microelements in the gastrointestinal tract chyme and feces were increased by H_LPS level and decreased by H_EGF level. The expression levels of most microelement transport-relative genes in the mucosa of gastrointestinal tissues were decreased by H_LPS level and increased by H_EGF level. In conclusion, dietary EGF could attenuate the negative effect of LPS exposure on the apparent digestibility of crude fat and microelement absorption through changing the expression levels of microelement transport-relative genes. EGF can be used as an additive to increase the essential trace elements absorption in the early weaning piglets.

Abstract

Epidermal growth factor (EGF) plays an important role in nutrients absorption. However, whether it can be an effective additive to improve the growth performance and nutrients absorption in lipopolysaccharide (LPS) challenged early weaning piglets is still unknown. A 14-days trial was conducted to investigate how EGF attenuates the effect of LPS on the growth performance, nutrient digestibility, microelement absorption of early-weaned pigs, and study the underlying mechanism. A total of 48 early weaned piglets, aged 25 days, were randomly distributed to four groups (control, EGF, LPS and EGF + LPS groups) consisting of a 2 × 2 factorial design. The main factors were the level of LPS (H_LPS = high LPS: 100 μg/kg body weight; Z_LPS = low LPS: 0 μg/kg body weight) and EGF (H_EGF = high EGF: 2 mg/kg diet; Z_EGF = low EGF: 0 mg/kg diet). Each group had four replicates and each replicate consisted of three piglets. The results showed that piglets injected with H_LPS level significantly decreased the average daily gain (ADG), and significantly increased the feed conversion ratio (FCR) compared with the piglets injected with Z_LPS level, while piglets fed H_EGF level significantly increased the average daily feed intake (ADFI) compared with the piglets fed Z_EGF level (p < 0.05). Piglets injected with H_LPS level significantly decreased the apparent digestibility of crude fat compared with the piglets injected with Z_LPS level (p < 0.05). Piglets injected with H_LPS level significantly increased the concentration of most microelements in the gastrointestinal tract chyme and feces, and significantly decreased the expression levels of most microelement transport-relative genes in the mucosa of gastrointestinal tissues compared with the piglets injected with Z_LPS level (p < 0.05). Piglets fed H_EGF level significantly decreased the concentration of microelement in the gastrointestinal tract chyme and feces, and significantly increased the expression levels of the microelement transport-relative genes in the mucosa of gastrointestinal tissues compared with the piglets fed Z_EGF level (p < 0.05). In conclusion, dietary EGF could attenuate the negative effect of LPS exposure on the apparent digestibility of crude fat and microelement absorption of early-weaning piglets. EGF and LPS influenced the absorption of essential trace element through changing the expression levels of microelement transport-relative genes in the mucosa of gastrointestinal tissues. In the early weaning piglets, EGF can be used as an additive to increase the essential trace elements absorption.

Statistical analysis/theoretical investigations of novel vascular endothelial growth factor of Davanoide from Scolymus grandifloras Desf as potent anti-angiogenic drug properties

Many pro-angiogenic factors acting directly or indirectly on the proliferation and differentiation of endothelial cells have been highlighted, in particular: VEGF ('Vascular Endothelial Growth Factor'), FGF ('Fibroblast Growth Factor'), PDGF ('Platelet-Derived Growth Factor'), VEGF exerts its pro-angiogenic activity by binding to the surface of receptors with tyrosine kinase activity (VEGFR). The first objective of this study was to elucidate the composition of the essential oil of the roots of Scolymus grandifloras Desf. The second aim was to describe the intra-species variation in essential oil composition in natural populations of 21 oil samples from different Algerian locations using statistical analysis and bioinformatical study of VEGFR inhibition. The essential oil isolated from the root parts, was a really source of Davanoide compounds. The results of the docking simulation revealed that davanone (Ligand 13) has an affinity to interact with cDNA, VEGF and its receptors. The ADMET properties and BOILED-Egg plot validate the compound 13 pass the brain barrier and have high absorption in the intestines with good bioavailability. The findings of this study contribute to the pharmacological knowledge and the therapeutic efficacy of davanone and can initiate the development of new anti-angiogenic drugs. Results showed that essential oil of Scolymus grandiflorus presented a large level of percentage of davanone, davanol D1 and 2-hydroxy davanone. These components may be a new source of nontoxic anticancer agents. However, an additional in vitro and/or in vivo experimental study should make it possible to verify the theoretical results obtained in silico.Communicated by Ramaswamy H. Sarma.

Comparative in vitro/theoretical studies on the anti-angiogenic activity of date pollen hydro-alcoholic extract: Highlighting the important roles of its hot polyphenols

Introduction: Date palm pollen (DPP) is the male reproductive soft powder from date flowers widely used as the valuable dietary supplement to fortify the size of testis and ovarian to increase the power of sex. This part of date palm significantly exhibited anti-diabetic, anti-inflammation and protective effects against male and female infertility. Though the anticancer activity of date fruits was previously reported, the DPP anti-angiogenic effects were not reported, and as the first study, its inhibitory effects were examined in the current study.

Methods: The DPP soft powder was collected to prepare its hydro-alcoholic extract to examine its anti-angiogenic activity in an in vitro model. At different concentrations, the cytotoxicity of the prepared extract was examined on human umbilical vein endothelial cells (HUVECs) using lactate dehydrogenase method. Cell proliferation was determined using the MTT assay and cytodex-3D model in collagen gel was used to assay its possible anti-angiogenic activity. The expression of VEGF, MMP-2 and MMP-9 genes was measured using real-time polymerase chain reaction (PCR). Finally, molecular docking simulation was used to highlight the possible role of DPP polyphenols to interact with the associated receptors.

Results: The prepared hydro-alcoholic extract exhibited significant anti-angiogenic activity in a dose-dependent manner and decreased the endothelial cell proliferation. The calculated IC₅₀ value for the examined extract in angiogenesis model was 260 µg·mL, respectively. Also, the expression of VEGF, MMP-2 and MMP-9 genes were significantly decreased. Docking simulation results unveiled that the isolated DPP polyphenols have the affinity to interact with ctDNA, VEGF and its receptors.

Conclusion: The DPP is the new source of non-toxic anti-cancer agents to use as a dietary supplement in the pre-treatment of cancer.

Human EGF-derived direct and reverse short linear motifs: conformational dynamics insight into the receptor-binding residues

Short linear motifs (SLiMs) have been recognized to perform diverse functions in a variety of regulatory proteins through the involvement in protein-protein interactions, signal transduction, cell cycle regulation, protein secretion, etc. However, detailed molecular mechanisms underlying their functions including roles of definite amino acid residues remain obscure. In our previous studies, we demonstrated that conformational dynamics of amino acid residues in oligopeptides derived from regulatory proteins such as alpha-fetoprotein (AFP), carcino-embryonic antigen (CEA), and pregnancy specific β1-glycoproteins (PSGs) contributes greatly to their biological activities. In the present work, we revealed the 22-member linear modules composed of direct and reverse AFP_14-20-like heptapeptide motifs linked by CxxGY/FxGx consensus motif within epidermal growth factor (EGF), growth factors of EGF family and numerous regulatory proteins containing EGF-like modules. We showed, first, the existence of similarity in amino acid signatures of both direct and reverse motifs in terms of their physicochemical properties. Second, molecular dynamics (MD) simulation study demonstrated that key receptor-binding residues in human EGF in the aligned positions of the direct and reverse motifs may have similar distribution of conformational probability densities and dynamic behavior despite their distinct physicochemical properties. Third, we found that the length of a polypeptide chain (from 7 to 53 residues) has no effect, while disulfide bridging and backbone direction significantly influence the conformational distribution and dynamics of the residues. Our data may contribute to the atomic level structure-function analysis and protein structure decoding; additionally, they may provide a basis for novel protein/peptide engineering and peptide-mimetic drug design.