Construction of ceRNA regulatory network in mice with Echinococcosis-induced allergic reactions

BACKGROUND

Cystic echinococcosis (CE) is a common chronic zoonotic parasitic disease infected with the Echinococcus granulosus. This study aimed to construct the competitive endogenous RNA (ceRNA) network and investigate the mechanism of mice in echinococcosis sensitization.

METHODS

The animal model of echinococcosis was established in mice, and the RNA sequencing was then performed using cysts. The differentially expressed RNAs (DERNAs: DEmRNAs, DEmiRNAs, and DElncRNAs) were screened between anaphylactic mice or non-anaphylactic mice and controls, respectively. The interactions of two DERNAs groups were identified and the ceRNA network was constructed. Moreover, the potential biological functions and pathways of the DEmRNAs were explored by enrichment analyses. Finally, the qRT-PCR and the western blot were performed to validate the expression levels of key RNAs and proteins.

RESULTS

A total of 285 common DEmRNAs, 157 common DElncRNAs and 4 common DEmiRNAs were observed. CeRNA network contained 3 DElncRNAs, 4 DEmiRNAs, and 27 DEmRNAs corporately. Enrichment results revealed that the functions of DEmRNAs focus on biological functions and pathways that specifically interact with the immune inflammatory response. In addition, the expression of 1700099I09Rik, let-7a-5p, Ccl28 and IL-13 was validated by RT-qPCR and western blot.

CONCLUSION

In this study, ceRNA network associated with CE sensitization in mice was constructed. The DEmRNAs in this network may be key clues for the immune mechanism of CE sensitization.

Canine atopic dermatitis - what have we learned?

Canine atopic dermatitis is a complex multifactorial disease. Here, Tim Nuttall, Maarja Uri and Richard Halliwell, representing three generations of veterinary dermatologists, describe the research underpinning our understanding of the condition and highlight its relevance to clinical practice.

IL-4 up-regulates epidermal chemotactic, angiogenic, and pro-inflammatory genes and down-regulates antimicrobial genes in vivo and in vitro: relevant in the pathogenesis of atopic dermatitis

Atopic dermatitis (AD) is a common chronic inflammatory skin disease. Although the pathogenesis of AD is not fully understood, we and others have shown that IL-4 plays a key role. In this study we aimed to identify keratinocyte genes regulated by IL-4 that may play important roles in the pathophysiology of AD. HaCat cells were treated with IL-4 at various concentrations for 24h, and PCR gene array on inflammation/autoimmunity was performed three times for analysis of differential gene expression. Of all the 370 genes examined, 32 and 53 genes are up- and down-regulated, respectively. Specifically related to AD, chemokines CCL3L1, CCL8, CCL24, CCL25, CCL26, CXCL6 and CXCL16 are up-regulated by IL-4. Pro-inflammatory factors, such as IL-19, IL-20, IL-1α, IL-12Rβ2, IL-25, IL-31RA, OSMR and nitric oxide synthase 2, are also up-regulated. In addition, IL-4 up-regulates VEGFA, a pro-angiogenic factor. In contrast, antimicrobial peptides (AMPs) or factors involved in APM production, such as IFN-κ, S100s, Toll-like receptors, and several chemokines are down-regulated. Similarly IL-4 also down-regulates TNF-α, lymphotoxin-β, an IgE suppressor, TNFSF18, a T-cells function regulator, and the glucocorticoid receptor. On the in vivo level, real-time RT-PCR on the selected genes confirmed that IL-4 up-regulates chemokines, proinflammatory cytokines while it suppresses AMP production related genes in the skin obtained from IL-4 Tg mice. Detailed examination of these genes will delineate their specific roles in chemotaxis, inflammation, angiogenesis and AMP production, all of which may contribute to the development and progression of AD.

Augmentation of CCL17 and CCL28 gene expression by TNF-alpha, IL-1beta, or IFN-gamma in cultured canine keratinocytes

Keratinocytes produce inflammatory mediators that are involved in the pathogenesis of skin disorders such as atopic dermatitis (AD). In particular, the CC chemokines, thymus and activation regulated chemokine (TARC)/CCL17 and mucosae-associated epithelial chemokine (MEC)/CCL28 are considered to play an important role in the lesional infiltration of lymphocytes in canine AD. However, there have been no reports on the regulatory mechanisms of CCL17 and CCL28 transcription in canine keratinocytes. In this study, we investigated whether CCL17 and CCL28 transcription in cultured keratinocytes is induced by TNF-alpha, IL-1beta, or IFN-gamma. It was found that CCL17 mRNA transcription is augmented by TNF-alpha only, whereas the CCL28 mRNA level could be increased by TNF-alpha, IL-1beta, or IFN-gamma. The present study suggests that pro-inflammatory cytokines are important inducing factors for the production of CCL17 and CCL28 in the lesional skin of dogs with AD.

Immunization of proteins from Toxascaris leonina adult worm inhibits allergic specific Th2 response

Recently, the influence of parasitic infections on the incidence of allergic diseases has become the focus of increased attention. In order to ascertain whether parasite-derived proteins could inhibit the allergic specific Th2 response, we applied excretory-secretory protein (Tl-ES) or total protein (Tl-TP) of the adult worm Toxascaris leonina to asthma model mice prior to or simultaneously with OVA challenge, after which we assessed the OVA-specific Th2 responses. The group subjected to immunization with Tl-ES and Tl-TP (immunized group) evidenced a thinning of the bronchial epithelial and muscle layer, a disruption and shedding of epithelial cells, a reduction in the number of goblet cells, and a reduction in mucus production as compared to the group treated with Tl-ES coupled with OVA challenge (challenge with OVA groups) and the OVA-induced asthma group. The administration of Tl-ES and Tl-TP, regardless of injection time, was shown to inhibit the recruitment of inflammatory cells into the airway, and in particular, macrophages, neutrophils, and lymphocytes were significantly reduced as the result of the parasite proteins. However, the total number of eosinophils was slightly reduced as the result of the administration of parasite proteins. Sensitization and OVA challenge was shown to accelerate the secretion of Th2 cytokines (IL-4 and IL-5) within the lung, but in the immunized groups, those levels were lower. The administration of Tl-TP and OVA challenge group also evidenced a significant reduction in IL-4 levels as compared to the OVA-challenged group. The concentrations of Th2 cytokines in the Tl-ES and OVA challenge group were more similar to those observed in the OVA-challenged group. The concentration of IL-10 and TGF-beta in the lung was decreased substantially in the OVA-only challenge group, but the Tl-TP immunized group exhibited significantly induced IL-10 cytokine. OVA-specific IgG2a, IgG1, and IgE levels in the immunized groups were significantly lower than those detected in the OVA-challenged group. In conclusion, parasite-derived protein is able to inhibit OVA-specific Th2 responses, and in particular, immunization with parasite proteins exerts a more profound protective effect than is seen with the treatment of allergic reactions. The results of our study are encouraging in terms of our further understanding of the molecular basis of immune evasion by nematodes.