Oral Administration of Bovine Lactoferrin-Derived Lactoferricin (Lfcin) B Could Attenuate Enterohemorrhagic <i>Escherichia coli</i> O157:H7 Induced Intestinal Disease through Improving Intestinal Barrier Function and Microbiota

Hua

et al. 2019

Sci Rep

Self Cite

The zoonotic enterohaemorrhagic Escherichia coli (EHEC) O157:H7 can disrupt intestinal epithelial barrier function and in turn leading to serious intestinal and systemic disease. PR39 could effectively inhibit the growth of Gram-negative bacteria, but there is little knowledge of its effects on intestinal barrier function and the microbiota in E . coli -challenged mice. In this study, an intestinal disease caused by EHEC O157:H7 was established, to analyze the effect of PR39 on EHEC O157:H7 induced intestinal epithelial barrier injury and disorder. Interestingly, PR39 attenuated EHEC O157:H7-induced systemic symptoms and significantly decreased mortality and the degree of E . coli shedding in faeces. Furthermore, the infiltration index of macrophages and neutrophils in intestine of the PR39 treatment group were obviously attenuated, along with the level of apoptosis. PR39 treatment group had distinctly improved tight junction associated proteins’ expression after EHEC O157:H7 caused injury. Additionally, the sequencing analysis of cecum microbiota showed that PR39 altered the abnormal increase in Bacteroides caused by EHEC O157:H7 and promoted the growth of probiotics such as Lactobacillus . In conclusion, cathelicidin-derived PR39 could effectively improve EHEC O157:H7-induced epithelial barrier injury, and dysfunction of immune and microbiota homeostasis in the intestinal tract, indicating that PR39 could be an excellent potential drug for zoonotic EHEC O157:H7-related intestinal disease.

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Cathelicidin- derived PR39 protects enterohemorrhagic Escherichia coli O157:H7 challenged mice by improving epithelial function and balancing the microbiota in the intestine

Hua

et al. 2019

Sci Rep

Self Cite

“…Recently, a therapeutic effect of bovine LFcin after oral intake was reported for the prevention of enterohemorrhagic E. coli (EHEC) infection in a mouse model [59], demonstrating, like numerous other studies, the potential of this antimicrobial peptide in veterinary and human medicine (reviewed in [34]). However, neither different amounts of polySia nor different polySia DPs can influence this ability of LFcin.…”

Section: Resultsmentioning

confidence: 79%

The Bovine Antimicrobial Peptide Lactoferricin Interacts with Polysialic Acid without Loss of Its Antimicrobial Activity against Escherichia coli

Kühnle

Galuska

Zlatina

et al. 2019

Animals

Simple Summary: Bovine milk contains a high concentration of the protein lactoferrin. It is an important antimicrobial biomolecule, which is also present in other bodily fluids like blood and semen. However, not only the intact protein but also its cleavage products have antimicrobial activity. Perhaps, the best-known cleavage product of lactoferrin is the peptide lactoferricin that has significant antimicrobial capacity against a broad range of pathogens such as enterohemorrhagic Escherichia coli (EHEC). Interestingly, lactoferricin can interact with the sugar polymer polysialic acid, which is also present in milk, blood, and semen. In the present study, we tested if the binding to polysialic acid influences the biological activity of bovine lactoferricin. Remarkably, neither different amounts of polysialic acid nor different chain lengths of this sugar polymer influenced the antimicrobial activity of lactoferricin. The ability of polysialic acid to bind and not inactivate lactoferricin may allow the development of novel endogenous and biodegradable polysialylated surfaces and/or hydrogels, which can be loaded with the antimicrobial peptide lactoferricin for biomedical applications in veterinary and human medicine. Abstract:The lactoferrin-derived peptide lactoferricin (LFcin) belongs to the family of antimicrobial peptides, and its bovine form has already been successfully applied to counteract enterohemorrhagic Escherichia coli (EHEC) infection. Recently, it was described that LFcin interacts with the sugar polymer polysialic acid (polySia) and that the binding of lactoferrin to polySia is mediated by LFcin, included in the N-terminal domain of lactoferrin. For this reason, the impact of polySia on the antimicrobial activity of bovine LFcin was investigated. Initially, the interaction of LFcin was characterized in more detail by native agarose gel electrophoresis, demonstrating that a chain length of 10 sialic acid residues was necessary to bind LFcin, whereas approximately twice-as-long chains were needed to detect binding of lactoferrin. Remarkably, the binding of polySia showed, independently of the chain length, no impact on the antimicrobial effects of LFcin. Thus, LFcin binds polySia without loss of its protective activity as an antimicrobial peptide.Lactoferrin can be excreted by epithelial cells, and the highest amounts have been determined in breast milk [8,9]. Besides epithelial cells, neutrophil granulocytes belong to the major producer of lactoferrin and, thus, high concentrations of lactoferrin can be found at inflammatory hotspots [7,8,10].Recently, the linear carbohydrate polysialic acid (polySia) has been identified as a probable binding partner for lactoferrin [11,12]. The building units of this polysaccharide are sialic acids, a group of α-keto acids with a nine-carbon backbone [13]. The sialic acid residues are mainly attached to each other via α2, 9 and/or α2,8 linkages [14]. In mammals, however, only α2,8-linked polymers, consisting of N-acetylneuraminic acid (Neu5Ac) residues, seem to be ...

“…Moreover, the imbalance in intestinal microbiota in functional gastrointestinal disorders (FGIDs) has been proven to increase the level of intestinal endotoxins and the production of pro-in ammatory factors as a result of damage caused to the intestinal mucosal barrier and changes in intestinal permeability, which lead to chronic low-grade in ammation and a decrease in the pH of the intestinal environment [24,25]. In our experiments, no differences in the bacterial phyla were found between HSP patients and healthy children, but signi cant changes in composition and structure were detected between gut microbial families of HSP patients and controls.…”

Section: Discussionmentioning

confidence: 99%

Effect of gut microbiota from Henoch-Schönlein Purpura patients on acid-sensitive ion channel 3 expression and intestinal motility in Germ-free rats

Zhao

yan

et al. 2020

Preprint

Background It has been proven that intestinal microbiota alterations and acid-sensing ion channels are associated with the development of Henoch-Schönlein Purpura (HSP) and that the brain-gut axis, which involves the gut microbiota, plays important roles in many diseases. However, there have been no reports published on changes in ASIC3 expression caused by gut microbial composition and its impact on the development of HSP. This study was to investigate the impact of the intestinal microbiota in children with abdominal HSP on ASIC3 expression and interactions between the microbiota and ASIC3 expression on the development of HSP. Methods Feces collected from HSP children and healthy children at the First Affiliated Hospital of Anhui Medical University were made into fecal microbial solutions. Germ-free rats were randomly assigned to either the control or HSP groups. The HSP group of rats were administered the fecal microbiota solution of HSP children, while the control group rats were administered the fecal microbiota solution of healthy children. Abdominal withdrawal reflex (AWR) and intestinal propulsion rate of the rats were used to determine visceral sensitivity. Composition of the gut microbiota of HSP children was determined using 16S rRNA gene sequencing. ASIC3 expression in the dorsal root ganglion (DRG) was ascertained through real-time PCR as well as western blotting analysis. Results The results showed a reduction in the number of species and abundance in the intestinal microbiota of children with HSP. Visceral sensitivity and intestinal propulsion rate of HSP group rats increased significantly, compared with the control group. ASIC3 mRNA and protein levels in the DRG of the spinal cord of rats in the HSP group were found to be upregulated. Conclusions The microbiota dysbiosis of HSP patients could stimulate ASIC3 expression in the DRG of the spinal cord, which in turn affected intestinal motility. These results suggested that regulation of the brain-gut axis may show potential for the development of therapies that can prevent or treat HSP children, especially patients with severe gastrointestinal manifestations.