Effects of Substance P and Neurokinin A on the Contractile Activity of Inflamed Porcine Uterus.

Disturbances in uterine contractile activity contribute to the development of inflammation, and recent evidence indicates that tachykinins, including substance P (SP) and neurokinin A (NKA), are involved in controlling uterine function. Here, we determined the effect of Escherichia coli (E. coli)-induced inflammation on expression of protein receptor subtypes for substance P (NK1R) and neurokinin A (NK2R) in the pig myometrium as well as their role in contractility of inflamed uterus. The severe acute endometritis developed in the E. coli group and the expression of NK1R and NK2R proteins increased in the myometrium. Compared to the pre-administration period, SP (10-6 M) reduced the amplitude and frequency in the myometrium of the E. coli group and the amplitude was higher and the frequency was lower versus other groups. NKA reduced the amplitude and increased the frequency in endometrium/myometrium of the E. coli group. In this group, the amplitude was lower and the frequency was higher than in the CON and SAL groups. Our research showed that NK2R (10-6 M) antagonist application abolished the NKA inhibitory effect on uterine amplitude. The application of the NK1R (10-5 M) antagonist together with SP revealed that the inhibitory effect of SP on uterine contractility is achieved independently of the NKR1. Additionally, taking into account the fact that NKA shows an inhibitory effect with the use of NK2R on uterine amplitude suggests the possibility of therapeutic use of the antagonist as a drug increasing uterine contractility in inflammation.

Profile for mRNA transcript abundances in the pig endometrium where inflammation was induced by Escherichia coli.

Uterine inflammation is a common reproductive disorder in domestic animals, leading to disturbances in many reproductive processes and economic losses. More information on inflammatory pathways, however, is needed to understand mechanisms of uterine inflammation. The aim of the study was to investigate transcriptomic profiles of the pig endometrium affected by inflammation. On day 3 of the estrous cycle (day 0 = initial day of study), saline or Escherichia coli suspension were injected into uterine horns. In endometrial tissues collected 8 days later, microarray analysis results indicated there were 189 differentially abundant mRNA transcripts (DEGs, 95 in relatively greater and 94 in lesser abundance) after saline injections compared with samples where there was severe acute inflammation. Relative abundance of mRNA transcripts for proteins assigned to inflammatory response, movement of phagocytes, quantity of phagocytes, leukocyte migration and adhesion of immune cells and many other functions related to inflammation were different in the Escherichia coli-treated endometrium than in samples from gilts treated with saline. Among others, S100A9, SLC11A1, CCL15, CCL3L3, CCR1, CD48, CD163, THBS1, KIT, ITGB3, JAK3 and NFKB2 mRNA transcripts were in relatively greater abundance and there were those in relatively lesser abundance including IL24, FGG, SST, CXCL16 and CREB. In this study, for the first time, there was detection of alterations in the transcriptome of the inflamed pig endometrium which may be an important finding for maintaining uterine homeostasis and functions. Results form the basis for future studies focusing on regulation of uterine inflammation in animals and women.

Ectromelia virus suppresses expression of cathepsins and cystatins in conventional dendritic cells to efficiently execute the replication process.

BACKGROUND: Cathepsins are a group of endosomal proteases present in many cells including dendritic cells (DCs). The activity of cathepsins is regulated by their endogenous inhibitors - cystatins. Cathepsins are crucial to antigen processing during viral and bacterial infections, and as such are a prerequisite to antigen presentation in the context of major histocompatibility complex class I and II molecules. Due to the involvement of DCs in both innate and adaptive immune responses, and the quest to understand the impact of poxvirus infection on host cells, we investigated the influence of ectromelia virus (ECTV) infection on cathepsin and cystatin levels in murine conventional DCs (cDCs). ECTV is a poxvirus that has evolved many mechanisms to avoid host immune response and is able to replicate productively in DCs. RESULTS: Our results showed that ECTV-infection of JAWS II DCs and primary murine GM-CSF-derived bone marrow cells down-regulated both mRNA and protein of cathepsin B, L and S, and cystatin B and C, particularly during the later stages of infection. Moreover, the activity of cathepsin B, L and S was confirmed to be diminished especially at later stages of infection in JAWS II cells. Consequently, ECTV-infected DCs had diminished ability to endocytose and process a soluble antigen. Close examination of cellular protein distribution showed that beginning from early stages of infection, the remnants of cathepsin L and cystatin B co-localized and partially co-localized with viral replication centers (viral factories), respectively. Moreover, viral yield increased in cDCs treated with siRNA against cathepsin B, L or S and subsequently infected with ECTV. CONCLUSIONS: Taken together, our results indicate that infection of cDCs with ECTV suppresses cathepsins and cystatins, and alters their cellular distribution which impairs the cDC function. We propose this as an additional viral strategy to escape immune responses, enabling the virus to replicate effectively in infected cells.