Upregulation of TLR-4 and proinflammatory cytokine transcripts as diagnostic indicator of endometritis in buffaloes

Therapeutic Role of miR-30a in Lipoteichoic Acid-Induced Endometritis via Targeting the MyD88/Nox2/ROS Signaling

Staphylococcus aureus (S. aureus), a notorious pathogenic bacterium prevalent in the environment, causes a wide range of inflammatory diseases such as endometritis. Endometritis is an inflammatory disease in humans and mammals, which prolongs uterine involution and causes great economic losses. MiR-30a plays an importan trole in the process of inflammation; however, the regulatory role of miR-30a in endometritis is still unknown. Here, we first noticed that there was an increased level of miR-30a in uterine samples of cows with endometritis. And then, bovine endometrial epithelial (BEND) cells stimulated with the virulence factor lipoteichoic acid (LTA) from S. aureus were used as an in vitro endometritis model to explore the potential role of miR-30a in the pathogenesis of endometritis. Our data showed that the induction of the miR-30a expression is dependent on NF-κB activation, and its overexpression significantly decreased the levels of IL-1β and IL-6. Furthermore, we observed that the overexpression of miR-30a inhibited its translation by binding to 3′−UTR of MyD88 mRNA, thus preventing the activation of Nox2 and NF-κB and ROS accumulation. Meanwhile, in vivo studies further revealed that upregulation of miR-30a using chemically synthesized agomirs alleviates the inflammatory conditions in an experimental mouse model of endometritis, as indicated by inhibition of ROS and NF-κB. Taken together, these findings highlight that miR-30a can attenuate LTA-elicited oxidative stress and inflammatory responses through the MyD88/Nox2/ROS/NF-κB pathway and may aid the future development of novel therapies for inflammatory diseases caused by S. aureus, including endometritis.

Curcumin inhibits lipopolysaccharide and lipoteichoic acid-induced expression of proinflammatory cytokines and production of PGE2 in the primary bubaline endometrial stromal cells

Infection of the uterus with Gram-positive Trueperella pyogenes and Gram-negative Escherichia coli is a common cause of postpartum endometritis in the cattle and buffalo and the condition is treated with antimicrobial drugs. The presence of drug residues in the milk and development of resistant bacteria necessitate the evaluation of alternate therapies for endometritis. Accordingly, we tested the immunomodulatory effect of curcumin in the bubaline endometrial stromal cells after treatment with the lipoteichoic acid (LTA) of Gram-positive Staphylococcus aureus and lipopolysaccharide (LPS) of Gram-negative E. coli that activate toll-like receptors (TLR-2 and TLR-4, respectively). Confluent primary culture of endometrial stromal cells was treated with LTA (1 µg/mL) and/or LPS (0.1 µg/mL), in the presence or absence of curcumin (30 µM for 24 h). PGE₂ was assayed in the supernatant and the relative expression of proinflammatory cytokines (PICs) (IL1B, IL6, IL8 and TNFA) transcripts were quantified using real-time PCR. LTA was not effective in stimulating PGE₂ production or upregulating the PIC expression except IL8. LTA+LPS increased PGE₂ production and upregulated IL6 and IL8 genes. Curcumin inhibited the basal and LTA+LPS induced production of PGE₂ and upregulation of PIC production. It was apparent that LPS, but not LTA, is a potent stimulator of PGE₂ from the bubaline endometrial stromal cells. Curcumin downregulated the expression of LPS and/or LTA induced PICs and PGE₂ and may be an alternate to antimicrobial drugs for the therapeutic management of endometritis.

Characterization of immunological, biochemical and inflammatory response of clinical and subclinical endometritis in ewes in the subtropics

Pluriparus Ossimi (n = 50) ewes were used to investigate the immune profile of the affected ewes to accurately diagnose clinical and subclinical endometritis and associations with biochemical variables. Ewes were slaughtered and animals were classified into control (no fertility problems), subclinical endometritis (SCE) and clinical endometritis (CE) groups based on pre-slaughter determinations of conception failure. Serum was collected from ewes to estimate concentrations of pro-inflammatory cytokines including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8) as well as nitric oxide (NO) concentration. The results from immunological evaluations indicated there were greater (P < 0.001) serum concentrations of IL-6, IL-8, TNF-α and NO in ewes classified with SCE and CE as compared to ewes of the control group. Furthermore, values for concentrations of TNF-α were positively correlated with IL-6 and IL-8 concentrations in ewes of the SCE and CE groups. In ewes classified with CE and SCE there were greater (P < 0.01) concentrations of blood glucose, ALT, AST, urea and creatinine than in ewes of the control group. It is concluded that serum pro-inflammatory cytokines IL-6, IL-8, and TNF-α are diagnostic markers for CE and SCE in ewes and serve as a criterion for different inflammatory complications in ewes classified as having CE or SCE.

Immunomodulatory effect of curcumin on lipopolysaccharide- and/or flagellin-induced production of prostaglandin E2 and relative expression of proinflammatory cytokines in the primary bubaline endometrial stromal cells

Developing alternate therapies for bovine endometritis is important in the context of drug residues in the milk and emergence of antimicrobial resistant bacteria. In this regard, we studied the immunomodulatory effect of curcumin 30 µM, on lipopolysaccharide- (LPS) and/or flagellin (100 ng/ml each)-induced prostaglandin E₂ (PGE₂ ) and proinflammatory cytokines (PIC) using primary bubaline endometrial stromal cells. After 24 hr treatment, the supernatant was assayed for PGE₂ while cells were used for relative quantification of cytokines like IL-1β, IL-6, IL-8 and TNF α transcripts using a control group as calibrator. LPS was found to possess potent stimulatory effect on PGE₂ production, whereas the flagellin was not as potent as LPS in stimulating the PGE₂ production either per se or in combination with LPS. LPS markedly up-regulated the transcripts of IL-8 and IL-6 as compared to IL-1β and TNF α in the bubaline endometrial stromal cells. Except for IL-8, flagellin did not up-regulate other PICs. There was no additive effect between LPS and flagellin on the up-regulation of inflammatory cytokines. Curcumin inhibited the LPS-induced up-regulation of PIC with strong down-regulation of IL-8. The inhibitory effects of curcumin on the inflammatory mediators suggest a potential in the treatment of bovine endometritis.

Expression of pathogen recognition receptors and pro-inflammatory cytokine transcripts in clinical and sub-clinical endometritis cows

The present study was carried out to examine the expression profile of pathogen recognition receptors (CD14 and toll-like receptor 4) and pro-inflammatory cytokines (IL-1β, IL-6, IL-8, and TNFα) in endometrial tissue of cows with endometritis at different stages of estrous cycle. Genital tracts were collected from 60 cows at slaughter from the killing village. The genitalia were examined for clinical endometritis (CE) and subclinical endometritis (SCE) through physical examination, white side test of cervico-vaginal mucus, endometrial cytology and histopathology. The stage of estrous cycle for each genitalia was determined by visual examination of both the ovaries and classified as either follicular (F) or luteal (L). Depending on the degree of inflammation and stage of estrous cycle, the genitalia were categorized in four groups i.e., FCE, FSCE, LCE, and LSCE with six genitalia in each group. Furthermore, 12 healthy genitalia comprise of six each of follicular (FN) and luteal (LN) were included as control. Endometrial tissue scrapings were collected ex vivo from all the genitalia. Total RNA was extracted and cDNA was transcribed for each sample and relative quantification of mRNA of target genes was done by real-time PCR. The results revealed a significant up-regulation of CD14 (11 fold) and IL-8 (13 fold) in follicular stage and IL-6 (8 fold) and TNFα (29 fold) in luteal stages in SCE cows. However, the majority of pro-inflammatory cytokine and pathogen recognition receptors expressed at significant higher level in both follicular and luteal stages in cows with CE. Thus, it is concluded that the endometrial transcripts of pathogen recognition receptors and pro-inflammatory cytokines expressed differentially in cows with endometritis, whereas the fold change is dependent on the severity of inflammation and the stage of cyclicity. Therefore, endometrial transcript profile with a defined threshold level could be used as a possible diagnostic marker in cows with SCE.