Determination of selected parameters for non-specific and specific immunity in cows with subclinical endometritis

A systematic review of predictive, diagnostic, and prognostic biomarkers for detecting reproductive diseases in cattle using traditional and omics approaches

Reproductive diseases and illnesses pose significant challenges in cattle farming, affecting fertility, milk production, and overall herd health. In recent years, the integration of various omics approaches, including transcriptomics, proteomics, metagenomics, miRNAomics, and metabolomics, has revolutionized the study of these conditions. This systematic review summarised the findings from studies that investigated reproductive disease biomarkers in both male and female cattle. After extracting 6137 studies according to exclusion and inclusion criteria, a total of 60 studies were included in this review. All studies identified were associated with female cattle and none were related to reproductive diseases in bulls. The analysis highlights specific biomarkers, metabolic pathways, and microbial compositions associated with bovine reproductive disease conditions, providing valuable insights into the underlying molecular mechanisms of disease. Pro-inflammatory cytokines such as IL-1β, IL-8, IL-4, IL-6, TNFα and acute-phase response proteins such as SAA and HP have been identified as promising biomarkers for bovine reproductive diseases. However, further research is needed to validate these markers clinically and to explore potential strategies for improving cow reproductive health. The role of bulls as carriers of venereal diseases has been underestimated in the current literature and therefore needs more attention to understand their impact on infectious reproductive diseases of female cattle.

Naringin attenuates inflammatory injury to the bovine endometrium by regulating the endoplasmic reticulum stress-PI3K/AKT-autophagy axis

Background: Endometritis seriously affects maternal reproductive health and fertility. Natural compounds have the characteristics of high efficiency and low residue in disease treatment. We aimed to discover and reveal the pharmacological effects of naringin, which is widely present in food and plants, on endometritis. Methods: Based on network pharmacology, the potential targets and pathways of naringin's actions on endometritis were predicted. Animal in vivo experiments were conducted to examine the inflammatory response of lipopolysaccharides (LPSs) in uterine tissue and the therapeutic effect of naringin. An in vitro primary bovine endometrial epithelial cell inflammation and drug treatment model was constructed. The production of reactive oxygen species (ROS) was measured using DCFH-DA, and the effect of naringin on LPS-induced endometritis was evaluated using HE staining, real-time quantitative PCR, Western blot, and immunofluorescence staining methods. Results: Naringin alleviated LPS-induced inflammatory injury and oxidative stress in the endometrium of mice and bovine endometrial epithelial cells (bEECs). Furthermore, in vitro studies were carried out to reveal the potential anti-inflammatory mechanisms of naringin based on network pharmacology. We found that naringin significantly inhibited LPS-stimulated endoplasmic reticulum stress (ERS)-related gene and protein expression, thus reducing the unfolded protein response (UPR). Furthermore, treatment of naringin attenuated the autophagic flux induced by ERS. In a further study, we observed that PI3K/AKT pathway inhibitors or ERS inducers partially reverse naringin's inhibition of autophagy and cell apoptosis. Conclusion: It is demonstrated that naringin suppresses autophagy by directly inhibiting the ERS-PI3K/AKT axis and exerting anti-inflammatory and antioxidant effects in endometritis. These findings provide novel insights into the pathogenesis of endometritis, highlighting potential therapeutic targets of traditional herbs and compounds.

Efficiency of conventional and nanoparticle oxytetracycline in treatment of clinical endometritis in postpartum dairy cows

The incidence of clinical endometritis in dairy cows postpartum is one of the important reasons for financial losses in the dairy industry. The costs of treatment, milk losses, infertility, repeated breeding, and high annual culling rate of dairy cows present immediate losses in case of treatment failure. The commonly used therapeutic methods for clinical endometritis have not been successful nor have given definitive solutions to overcome the complications of the disease in dairy cows. Therefore, it was necessary to propose an innovative treatment program to overcome the reasons for the failure and lack of effectiveness of the treatment of clinical endometritis. This was tackled in the current study; oxytetracycline with different concentrations, oxytetracycline 5% (OTCC5%), oxytetracycline 20% (OTCC20%), and oxytetracycline 20% nanoparticles (OTC-NPs) were used for the treatment of clinical endometritis. Diagnosis of clinical endometritis was based on the assessment of high serum concentration of pro-inflammatory cytokines, acute phase protein, increased endometrium thickness, and intrauterine discharges with different degrees of echogenicity monitored by ultrasonography. Application of OTC-NPs revealed a decrease in serum concentration of pro-inflammatory cytokines (IL-1, IL-6, and TNF-α) and acute phase proteins compared to OTCC20% and OTCC5% groups. The improvement achieved by OTC-NPs may be attributed to the reduction of OTC particles into nano size which facilitates its tissue bioavailability, dispersion, penetration power to deeper tissues, and its more broad-spectrum activities. These activities were clearly apparent after the evacuation of uterine contents using a single dose of PGF2α. The OTC-NPs revealed a reduction in serum concentration of cytokines compared to OTCC20% and OTCC5% groups arranged as follows: 10.11, 25.45, 35.56 for IL-1; 99, 300, 319 for IL-6; 1.01, 4.40, 8.06 for CRP; and 46, 183, 266 for TNF-α. Furthermore, an increase in serum concentration of albumin (3.34) was obtained by OTC-NPs compared to OTCC5% (1.70). This improvement can be taken as evidence of liver resumption functions and inflammatory reactions. On the other side, globulin concentration recorded an increase like albumin and total proteins in OTC-NPs compared to others. A reduction in the endometrium thickness in OTC-NPs with the disappearance of intrauterine discharges was monitored by ultrasonography. This confirmed the subsiding of clinical endometritis in OTC-NPs group. Moreover, a significant improvement in conception and pregnancy rate in OTC-NPs compared to other groups were observed.

Effect of Inonotus obliquus polysaccharide on composition of the intestinal flora in mice with acute endometritis

Inonotus obliquus Polysaccharide (IOP) is a large molecule extracted from Inonotus obliqus, a medicinal fungus, which has a wide range of biological activities and has been shown to be associated with inflammation. The purpose of this study is to investigate whether IOP can help to reduce acute endometritis by regulating intestinal flora. We observed pathological changes in mice with endometritis following treatment with IOP and evaluated changes in the levels of interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α), and further studied the effects of IOP on the intestinal flora of endometritis mice using 16S rRNA high-throughput sequencing. The results showed that IOP improved the condition of uterine tissues and reduced the release of pro-inflammatory cytokines. Meanwhile, the 16S rRNA sequencing results showed that IOP could regulate the changes in intestinal microflora at the level of genera, possibly by changing the relative abundance of some genera.

MicroRNA: Could It Play a Role in Bovine Endometritis?

Endometritis in dairy cows is a major economic problem worldwide; without advances in lifestyle management and drug treatment, it causes high morbidity and death. Micro ribonucleic acid (miRNAs) these days is seen as an important part of gene control networks. It is a class of small nucleotides 20-25, single-stranded RNA molecules. In endometritis, the inflammatory response caused by the gram-negative bacteria Escherichia coli (E. coli) alters the expression of miRNA which can regulate the innate immune system. This manuscript reviews (1) the interaction of miRNAs with the signaling of NF-κB and dysregulation of miRNAs and NF-κB activity in endometritis and (2) the activity of miR-let-7c, miR-148a, and miR-488 in NF-κB activation and their effect on endometritis. Cows with reduced immunity are more vulnerable to transition diseases, such as endometritis. During post-partum, cows undergo stress, metabolic disorders, hormonal imbalance, negative energy balance, and changes in diet. One of the many categories of regulatory molecules, which explain its natural function and pathological impact on NF-κB dysregulation, is important to inform the complexity of the immune system and to develop treatments for endometritis. It shows that miRNAs could have multiple applications in veterinary medicine. Nevertheless, a comprehensive study of is essential which should be aimed at exploring the role of microRNA at physiological level and its effect due to dysfunction and dysregulation.

Adaptive immunity in the postpartum uterus: Potential use of vaccines to control metritis

After parturition, dairy cows rely on an effective innate immune response, through the actions of neutrophils, macrophages, and antimicrobial peptides, to clear the uterus from pathogenic bacteria, such as E. coli, Bacteroides spp, F. necrophorum and T. pyogenes. However, the role of adaptive immunity in the postpartum uterus is less understood. In this review, we explore concepts of mucosal adaptive immunity and discuss recent findings regarding the efficacy of vaccines to reduce metritis in dairy cows. Areas of lymphocytic aggregates are seen throughout the bovine reproductive tract after parturition, but it is unknown if their development is influenced by previous exposure to pathogens or other intrinsic factors. Through the actions of Treg cells and γδ T cells, the uterus is an immune-tolerant environment during pregnancy. After parturition, the dynamics in the endometrial and circulating lymphocytic populations differ among cows that develop uterine diseases and healthy counterparts. However, the functionality of those cells has not yet been determined. It has been hypothesized that cows that fail to switch their uterine environment from an anti-inflammatory state prior to parturition to a pro-inflammatory state after calving are more susceptible to uterine infections. Given the nature of metritis related pathogens and the importance of innate immunity to uterine defense mechanisms, we speculate that an adaptive immunity biased towards a Th1/Th17 cellular response will provide best protection against uterine infections. Few studies have evaluated the efficacy of immunization in reducing the incidence of metritis in dairy cows revealing inconsistent findings.

miR-148a suppresses inflammation in lipopolysaccharide-induced endometritis

Endometritis is a postnatal reproductive disorder disease, which leads to great economic losses for the modern dairy industry. Emerging evidence indicates that microRNAs (miRNAs) play a pivotal role in a variety of diseases and have been identified as critical regulators of the innate immune response. Recent miRNome profile analysis revealed an altered expression level of miR‐148a in cows with endometritis. Therefore, the present study aims to investigate the regulatory role of miR‐148a in the innate immune response involved in endometritis and estimate its potential therapeutic value. Here, we found that miR‐148a expression in lipopolysaccharide (LPS)‐stimulated endometrial epithelial cells was significantly decreased. Our results also showed that overexpression of miR‐148a using agomiR markedly reduced the production of pro‐inflammatory cytokines, such as IL‐1β and TNF‐α. Moreover, overexpression of miR‐148a also suppressed NF‐κB p65 activation by targeting the TLR4‐mediated pathway. Subsequently, we further verified that miR‐148a repressed TLR4 expression by binding to the 3′‐UTR of TLR4 mRNA. Additionally, an experimental mouse endometritis model was employed to evaluate the therapeutic value of miR‐148a. In vivo studies suggested that up‐regulation of miR‐148a alleviated the inflammatory conditions in the uterus as evidenced by H&E staining, qPCR and Western blot assays, while inhibition of miR‐148a had inverse effects. Collectively, pharmacologic stabilization of miR‐148a represents a novel therapy for endometritis and other inflammation‐related diseases.

Oridonin Ameliorates Lipopolysaccharide-Induced Endometritis in Mice via Inhibition of the TLR-4/NF-κBpathway

Endometritis is a health threat to both humans and animals and poses a huge economic burden. Oridonin (Ori) is a natural diterpenoid isolated from the traditional Chinese herb Rabdosiarubescens (R. rubescens) and has multiple health-promoting effects, including antioxidant, anti-inflammatory, and antitumor effects. There is little evidence showing that Ori can effectively treat endometritis, and the relevant mechanisms need to be further clarified. In this study, we investigated the effects of Ori on LPS-induced endometritis in vivo. Additionally, we examined the effects of Ori on LPS-stimulated mouse endometrial epithelial cells (mEECs). The results showed that Ori treatment significantly alleviated LPS-induced endometritis and reduced the activity of myeloperoxidase. ELISA and qPCR results indicated that Ori dose-dependently decreased the expression of TNF-α, IL-1β, and IL-6 both in tissues and in mEECs. In addition, Ori was found to inhibit LPS-induced TLR4/NF-κB signaling pathway activation. These results suggest that Ori effectively attenuates LPS-induced endometritis by inhibiting the TLR4/NF-κB signaling pathway and that Ori might be an effective drug for the prevention and treatment of LPS-induced endometritis.

Engeletin Alleviates Lipopolysaccharide-Induced Endometritis in Mice by Inhibiting TLR4-mediated NF-κB Activation

Engeletin (dihydrokaempferol 3-rhamnoside) is a flavanonol glycoside. It can be found in the skin of white grapes and white wine and is widely distributed in southeast Asia, and the leaves are used in a tea. Here, we explored the impact of engeletin against the inflammatory reaction in a lipopolysaccharide (LPS)-induced endometritis mouse model. Engeletin treatment significantly attenuated uterus damage and decreased myeloperoxidase activity. ELISA and qPCR assays showed that engeletin dose-dependently suppressed the expression of TNF-α, IL-1β, and IL-6. Molecular studies also demonstrated that the levels of iNOS, COX-2, and TLR4, along with their downstream molecules MyD88, IRAK1, TRAF6, and TAK1, were also suppressed by engeletin. In addition, engeletin treatment inhibited NF-κB signaling-pathway activation. Moreover, immunofluorescence analysis demonstrated that engeletin suppressed NF-κB-p65 nuclear translocation. These data indicated the protective action of engeletin against LPS-stimulated endometritis in mice via negative regulation of pro-inflammatory mediators via the TLR4-regulated NF-κB pathway.

TIIA attenuates LPS-induced mouse endometritis by suppressing the NF-κB signaling pathway

Endometritis is one of the main diseases that harms the dairy cow industry. Tanshinone IIA (TIIA), a fat-soluble alkaloid isolated from Salviae miltiorrhizae, has been reported to have potent anti-inflammatory properties. However, the anti-inflammatory effects of TIIA on a mouse model of lipopolysaccharide (LPS)-induced endometritis remain to be elucidated. The purpose of the present study was to investigate the effects of TIIA on LPS-induced mouse endometritis. TIIA was intraperitoneally injected 1 h before and 12 h after perfusion of LPS into the uterus. A histological examination was then performed, and the concentrations of myeloperoxidase (MPO) and nitric oxide (NO) in the uterine tissue were determined. The levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in a homogenate of the uterus were detected by enzyme-linked immunosorbent assay. The extent of phosphorylation of IκBα and p65 was detected by Western blotting. TIIA markedly reduced the infiltration of neutrophils, suppressed MPO activity and the concentration of NO, and attenuated the expression of TNF-α and IL-1β. Furthermore, TIIA inhibited the phosphorylation of the nuclear factor-kappa B (NF-κB) p65 subunit and the degradation of its inhibitor IκBα. All the results suggest that TIIA has strong anti-inflammatory effects on LPS-induced mouse endometritis.

Inflammatory cytokine and acute phase protein concentrations in the peripheral blood and uterine washings of cows with subclinical endometritis in the late postpartum period

The aim of the study was to evaluate the concentrations of proinflammatory cytokines: tumor necrosis factor (TNF-α) and interleukin-6 (IL-6), anti-inflammatory cytokine interleukin-10 (IL-10), and acute phase proteins (APPs)—haptoglobin (Hp) and serum amyloid A (SAA) in serum and uterine washings of cows with subclinical endometritis, and compare them to healthy animals. The study was performed on 24 cows on day 60 after delivery. The cows were divided into two groups based on the results of cytological tests: 12 cows with subclinical endometritis and 12 healthy cows. Experimental material consisted of blood serum and uterine washings. The levels of the following cytokines in the study material were determined with ELISA: TNF-α, IL-6, IL-10 and APPs - Hp and SAA. The results show that the levels of TNF-α (p < 0.01), IL-6, IL-10 as well as SAA and Hp were significantly higher in the serum of cows with subclinical endometritis compared to the controls (p < 0.001). Uterine washings had significantly higher levels of IL-6, IL-10, and Hp in the experimental cows compared to the controls (p < 0.001). The demonstrated differences in the concentration of cytokines and APP between cows with subclinical endometritis and healthy cows, in both the serum and uterine washings, may suggest the usefulness of these parameters in the diagnosis of subclinical endometritis in cows in the late postpartum period.

The concentrations of inflammatory cytokines and acute-phase proteins in the peripheral blood and uterine washings in cows with pyometra

The development of pyometra in cows depends largely on the state of local immunity of the uterus. The objective of the study was to evaluate the concentration of the following proinflammatory cytokines: tumour necrosis factor (TNF-α) and interleukin-6 (IL-6); anti-inflammatory cytokine: interleukin-10 (IL-10); and acute-phase proteins (APPs): haptoglobin (Hp) and serum amyloid A (SAA), in serum and uterine washings in cows with pyometra and healthy animals. The study was performed on 20 cows divided into two groups based on the results of cytological and ultrasonographic tests: a pyometra and a healthy group (10 cows per group). Experimental material consisted of blood serum and uterine washings. The levels of the following cytokines, TNF-α, IL-6, IL-10 and APPs - Hp and SAA, in the study material were determined by ELISA. The results showed that the values of TNF-α, IL-6, IL-10 as well as SAA and Hp were significantly higher in serum of cows with pyometra compared to controls (p < 0.001). The uterine washings had significantly higher levels of IL-6, IL-10, and Hp in pyometra cows compared to the control (p < 0.001). Our results indicate that it is possible to monitor the course of pyometra in cows based on the evaluation of the concentration of cytokines and Hp in the serum and uterine washings. Simultaneous evaluation of selected indicators of antagonistic interaction can be helpful in determining the current status of local immunity of the uterus. On this basis, it could be possible to properly select an adjunctive therapy in the form of immunomodulating preparations.

Inflammatory cytokines and acute-phase proteins concentrations in the peripheral blood and uterus of cows that developed endometritis during early postpartum

The aim of the study was to evaluate the level of proinflammatory cytokines (tumor necrosis factor-α [TNF-α], interleukin-6 [IL-6]), anti-inflammatory cytokine (interleukin-10 [IL-10]), and acute-phase proteins (haptoglobin [Hp] and serum amyloid A [SAA]) in serum and uterine washings in cows that developed endometritis during the early postpartum period. The study was carried out on 40 cows. The experimental group consisted of 20 cows with subclinical endometritis and the control group of 20 cows without endometritis. Analyses in both groups of cows were carried out at 5, 22, and 40 days postpartum (DPP). Experimental material consisted of the blood serum and uterine washings. The levels of the following cytokines: TNF-α, IL-6, IL-10 and acute-phase proteins: Hp and SAA were determined using ELISA. Our study reported that the levels of TNF-α, IL-6, IL-10, Hp, and SAA at 22 DPP were higher in cows with subclinical endometritis (P < 0.001). The levels of TNF-α (P = 0.01), IL-6 and IL-10 (P = 0.001), and Hp (P < 0.001) at 40 DPP were higher in cows with subclinical endometritis compared to healthy cows. The level of IL-10 in uterine washings at 5 DPP was higher (P = 0.001), whereas of SAA was lower (P = 0.01) in cows with subclinical endometritis. At 22 DPP, the levels of IL-6, IL-10, and Hp were higher (P < 0.001) in cows with endometritis. At 40 DPP, the level of TNF-α was lower, whereas these of IL-10 and Hp were elevated (P < 0.001) in cows with endometritis compared to healthy cows. The results indicate that the evaluation of the levels of cytokines and Hp in serum, but primarily in uterine washings, can be an important diagnostic indicator in cows that developed subclinical endometritis. High levels of IL-10 in cows with subclinical endometritis may contribute to the weakening of local resistance mechanisms of the uterus and lead to the persistence of the inflammation in the postpartum period. The present study also shows that the simultaneous examination of selected parameters of antagonistic interactions allows for better assessment of the current state of local immunity in the uterus.