Punicalagin protects bovine endometrial epithelial cells against lipopolysaccharide-induced inflammatory injury

Downregulation of XBP1s aggravates lipopolysaccharide-induced inflammation by promoting NF-κB and NLRP3 pathways' activation in goat endometrial epithelial cells

After delivery, bacterial contamination and uterine tissue degeneration in animals can lead to the development of uterine diseases, such as endometritis, accompanied by endoplasmic reticulum stress (ERS). Increasing evidence suggests that spliced X-box binding protein 1 (XBP1s), a critical component of ERS, is involved in several pathological processes in various organisms. However, the specific molecular mechanisms by which XBP1s mediates the inflammatory response in goat endometrial epithelial cells (gEECs) remain largely unknown. In the present study, XBP1s protein was induced into the nucleus in the lipopolysaccharide (LPS, 5 μg/mL)-induced inflammatory response of gEECs. Lipopolysaccharide-induced expression and nucleation of XBP1s were reduced by the inhibition of Toll-like receptor 4 (TLR4) using TAK-242 (1 μM; a TLR4 inhibitor). Expression and nucleation of XBP1s were similarly reduced when the activity of inositol-requiring enzyme 1α (IRE1α) was inhibited using 4μ8C (10 μM; an IRE1α inhibitor). In addition, inhibition of IRE1a increased IL-1β, TNF-α, and IL-8 levels and secretion of IL-6 induced by LPS. Notably, phosphorylation of nuclear factor kappa-B (NF-κB) P65 protein and expression of NOD-like receptor thermal protein domain associated protein 3 (NLRP3) were similarly increased. Furthermore, knockdown of XBP1s in gEECs consistently promoted NF-κB P65 protein phosphorylation, NLRP3 protein expression, and inflammatory cytokine secretion. In summary, the current results suggest that in the LPS-induced inflammatory response in gEECs, LPS generates intracellular signaling cascades in gEECs via TLR4, which may promote XBP1s protein expression and nucleation by activating IRE1a. However, downregulation of XBP1s expression exacerbates inflammation by promoting activation of the NF-κB and NLRP3 inflammatory vesicle pathways. These results will potentially contribute to the treatment and prevention of endometritis in ruminants.

Effect of VD3 on cell proliferation and the Wnt signaling pathway in bovine endometrial epithelial cells treated with lipopolysaccharide

Vitamin D (VD) deficiency plays an important role in the occurrence and development of various uterine diseases. At present, most studies on the mechanism of VD in the Wnt signaling pathway focus on cancer, while there are no relevant reports on its mechanism in endometritis. This study investigated the effect of vitamin D3 (VD3) on the Wnt signaling pathway in endometrial epithelial cells (BEECs) induced by lipopolysaccharide (LPS). BEECs obtained from bovine uteri were treated with VD3 (0, 50 ng/mL) and LPS (0, 10, 100 ng/mL) separately or in combination, and treated with the Wnt signaling pathway inhibitor IWR-1 to study the mechanism of action. The proliferation of BEECs was evaluated by a CCK-8 assay. qRT-PCR was used to assess the gene expression of Wnt pathway-related factors, including MYC, PCNA, LGR5, GREM1, β-catenin, FZD7, FZD2, Wnt4 and VDR. The results showed that VD3 had no significant effect on cell proliferation (P > 0.05); LPS inhibited BEEC proliferation in a time- and dose-dependent manner, and cells treated with LPS at different concentrations for 24-48 h in combination with VD3 promoted cell proliferation to varying degrees. IWR-1 inhibited cell proliferation in a time- and concentration-dependent manner, while LPS + IWR-1 treatment also significantly promoted cell proliferation after VD3 treatment (P < 0.01). The qRT-PCR results showed that the expression of Wnt4 and PCNA genes showed different trends with different LPS concentrations for stimulation, and the expression of the MYC and GREM1 genes was only stimulated by high-dose (100 ng/mL) LPS stimulation. The expression of FZD7, LGR5, FZD2 and β-catenin was upregulated by LPS at both concentrations. LPS + VD3 significantly downregulated the expression of the Wnt pathway-related genes MYC, PCNA, LGR5, GREM1 and β-catenin (P < 0.001), Wnt4 and FZD2 (P < 0.01), and significantly upregulated the expression of VDR (P < 0.05). After LPS + IWR-1 treatment, the expression of the β-catenin (P < 0.01) and LGR5 (P < 0.05) genes was significantly downregulated, while the Wnt4 (P < 0.01) and VDR (P < 0.001) genes were significantly upregulated, MYC was downregulated but without a significant difference (P > 0.05). In conclusion, VD3 treatment can mitigate the LPS-induced abnormal expression of Wnt signaling pathway genes in BEECs, showing that the Wnt pathway may be a protective pathway of VD3 against LPS-induced gene overexpression in BEECs. The results suggest that VD3 may play a regulatory role in pathways other than the Wnt signaling pathway. Whether VD3 affects the Wnt signaling pathway by affecting Wnt4 gene expression requires further study.

The bioactivity and applications of pomegranate peel extract: A review

Pomegranate peel (PP) is a by-product in the processing of pomegranate products, which is usually discarded as a waste. However, a large number of researches have shown that pomegranate peel extract (PPE) is rich in a variety of phenolic substances, among which ellagic acid (EA), as one of the main active components, has significant biological activities, such as anti-oxidation, anti-tumor, anti-inflammatory, neuroprotection, anti-viral, and anti-bacterial. We analyzed the mechanism of EA's biological activity, and discussed its application in the food industry, for instance, food preservation, food additives, and functional foods. Combined with the research status of PPE, we discussed the limitations and development potential of PPE, in order to provide theoretical reference and scientific basis for the development and utilization of pomegranate by-products. PRACTICAL APPLICATIONS: Pomegranate peel (PP), the inedible part of the fruit, is usually treated as waste. In recent years, researchers have been committed to exploring various bioactive ingredients in PP and exploring its potential benefits to human health, which has far-reaching significance. In this paper, the chemical constituents of polyphenols in PP were reviewed, mainly focusing on the biological activity and mechanism of ellagic acid (EA). We reviewed the applications and invention patents of pomegranate peel extract (PPE) in food field, including food preservation, food additive, and functional foods, providing reference for the recycling and reuse of PP.

Antifungal and Anti-inflammatory Effect of Punicalagin on Murine Aspergillus fumigatus Keratitis

PURPOSE

This study aimed to investigate the anti-inflammatory effect and antifungal effect of punicalagin in murine fungal keratitis.

METHODS

We used in vitro and in vivo protocols to assess the anti-inflammatory effect and antifungal effect of punicalagin. In vitro, time kill and mycelial stain were done. In vivo, murine fungal keratitis was established and treated with PBS or PUN. Clinical scores were taken on days 1, 3, and 5 post infection. The mRNA and protein levels of inflammatory factors were detected by RT-PCR and Western blot, and the number and location of macrophages were analyzed by flow cytometry and immunofluorescence. Also, fungal plate counting was used to assess the antifungal effect. The DCFH-DA fluorescence probe detected the ROS level.

RESULTS

In vitro, PUN showed activity against A.fumigatus. (A.F.), with MIC90 values of 250 μg/ml, and significantly reduced A.F. biofilm formation (p < .001). In vivo, the mouse fungal keratitis model after punicalagin treatment exhibited less disease, lower clinical scores (p < .05), lower reduced macrophage infiltrate (p < .001), and fungal load (p < .001) than those treated with PBS. Treatment with punicalagin also reduced the mRNA expression and protein level of pro-inflammatory factors. At the cellular level, PUN significantly reduced the mRNA expression of inflammatory factors and ROS production caused by the stimulation of mycelia in RAW264.7 (p < .001).

CONCLUSIONS

The results show that punicalagin is beneficial in the treatment of murine fungal keratitis. The mechanism of its anti-inflammatory effect was synthetical, including antifungal activity, an inhibitory effect of proinflammatory factor and macrophages, and anti-oxidation.

Punicalagin Regulates Signaling Pathways in Inflammation-Associated Chronic Diseases

Inflammation is a complex biological defense system associated with a series of chronic diseases such as cancer, arthritis, diabetes, cardiovascular and neurodegenerative diseases. The extracts of pomegranate fruit and peel have been reported to possess health-beneficial properties in inflammation-associated chronic diseases. Punicalagin is considered to be the major active component of pomegranate extracts. In this review we have focused on recent studies into the therapeutic effects of punicalagin on inflammation-associated chronic diseases and the regulatory roles in NF-κB, MAPK, IL-6/JAK/STAT3 and PI3K/Akt/mTOR signaling pathways. We have concluded that punicalagin may be a promising therapeutic compound in preventing and treating inflammation-associated chronic diseases, although further clinical studies are required.

Punicalagin attenuates osteoarthritis progression via regulating Foxo1/Prg4/HIF3α axis

BACKGROUND

Punicalagin (PUN) is a common anti-inflammatory polyphenol. However, the function and mechanism of PUN in osteoarthritis remains unknown.

METHODS

Chondrocytes were isolated from rats, and confirmed by toluidine blue staining and immunofluorescence. Chondrocytes were challenged by lipopolysaccharide (LPS), and rat osteoarthritis model was established by Hulth method. The secretion of inflammatory factors, cell viability and apoptosis were tested via enzyme linked immunosorbent assay (ELISA), MTT and flow cytometry. The levels of forkhead box O1 (Foxo1), proteoglycan 4 (Prg4), hypoxia-inducible factor-3α (HIF3α), autophagy-related genes or extracellular matrix (ECM)-related proteins were examined via quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blot or immunohistochemistry. The cartilage tissue damage was assessed via hematoxylin-eosin (HE) staining, toluidine blue staining and terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick and labeling (TUNEL) staining.

RESULTS

LPS triggered inflammatory injury in chondrocytes. PUN promoted autophagy to mitigate LPS-induced inflammatory injury. Foxo1 silence attenuated the effect of PUN on LPS-mediated autophagy inhibition and inflammatory injury. Promotion of Prg4/HIF3α axis abolished the influence of Foxo1 knockdown on LPS-mediated chondrocytes injury. PUN mitigated the inflammatory injury in rat osteoarthritis model by promoting autophagy and inhibiting inflammation and ECM degradation via Foxo1/Prg4/HIF3α axis.

CONCLUSION

PUN attenuates LPS-induced chondrocyte injury and osteoarthritis progression by regulating Foxo1/Prg4/HIF3α axis.

Lipopolysaccharide stimulates bovine endometrium explants through toll‑like receptor 4 signaling and PGE2 synthesis

Bovine endometrium infection with gram-negative bacteria commonly causes uterine diseases. Previous studies indicate that prostaglandin E₂ (PGE₂) is an inflammatory mediator in bacterial endometritis. However, the mechanism underlying lipopolysaccharide (LPS)-induced inflammatory response regulation in bovine endometrial explants remains elusive. In the present study, bovine explants were pre-treated with 15-hydroxyprostaglandin dehydrogenase (15-PGDH) inhibitors before LPS stimulation. PGE₂ secretion, prostaglandin synthetase, pro-inflammatory factor, damage-associated molecular pattern (DAMP), and related signaling pathway factor levels were evaluated. Using 15-PGDH inhibitors pre-treatment, LPS-treated bovine endometrial explants exhibited augmentation of PGE₂ and DAMP expression, and upregulation of various signaling pathway factors. Protein kinase A (PKA), extracellular-signal-regulated kinase, and c-Jun N-terminal kinase phosphorylation and degradation of nuclear transcription factor-κB (NF-κB) inhibitors were induced in the pre-treated endometrial explants. The mechanism underlying LPS-induced PGE₂ accumulation acting as a pro-inflammatory mediator through toll-like receptor 4 signaling in bovine explants could involve the PKA, mitogen-activated protein kinase, and NF-κB pathways.

Activation of alpha7 nicotinic acetylcholine receptor protects bovine endometrial tissue against LPS-induced inflammatory injury via JAK2/STAT3 pathway and COX-2 derived prostaglandin E2

Bovine endometritis is one of the major postpartum diseases associated with infertility and subfertility, decreasing the benefit of dairy industry. It is important to develop alternate therapies for endometritis in the context of drug residues in the milk and hormone disorder in the estrous cycle. α7 nicotine acetylcholine receptor has been identified as the core of 'cholinergic anti-inflammatory pathway (CAP)', which is a potential drug target to inflammatory diseases. However, there has been still no study on its anti-inflammatory effects and mechanism on lipopolysaccharide (LPS)-induced bovine endometritis. This study aimed to demonstrate the underlying anti-inflammatory effects and mechanism of α7-nACh receptor on LPS-induced inflammation in bovine endometrial tissues cultured in vitro. The results suggested that activation of α7-nACh receptor significantly suppressed the mRNA expression levels of interleukin 1β (IL-1β), IL-6, IL-8, and tumor necrosis factor alpha (TNF-α) in bovine endometrial tissues. Western blot and enzyme-linked immunosorbent assay (ELISA) detection results showed that activation of α7-nACh receptor inhibited LPS-induced phosphorylation of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3). Moreover, α7-nACh receptor agonist decreased the expression of cyclooxygenase 2 (COX-2) and microsomal prostaglandin E synthase-1(mPGES-1), as well as prostaglandin E₂ (PGE₂) secretion. Interestingly, in COX-2 inhibition experiment, activation of α7-nACh receptor increased COX-2 expression and PGE₂ production, compared with COX-2 inhibitor treatment. In conclusion, activation of the cholinergic system through α7-nACh receptor agonist has suppressed inflammation of bovine endometrial tissues via JAK2/STAT3 pathway and potential COX-2-derived PGE₂.

Punicalagin Exerts Protective Effects against Ankylosing Spondylitis by Regulating NF-κB-TH17/JAK2/STAT3 Signaling and Oxidative Stress

Background

Ankylosing spondylitis (AS) is a chronic inflammatory disease characterized by sacroiliitis and spinal rigidity of the axial joints. The role of oxidative stress and increased proinflammatory cytokines is well documented in AS pathogenesis. Punicalagin (2,3-hexahydroxydiphenoyl-gallagyl-D-glucose), an ellagitannin widely present in pomegranates, is found to exhibit potent anti-inflammatory, antiproliferative, and antioxidative effects. The present study was undertaken to investigate the effects of punicalagin in a rodent model of AS.

Methods

BALB/c mice induced spondylitis were sacrificed 24 h after the last injection of proteoglycan extract. Histological scoring was done to assess the degree of the disease. The expression of JAK2/STAT3 proteins and proteins of the nuclear factor-κB (NF-κB) pathway was determined by immunoblotting. Serum levels of inflammatory mediators—TNF-α, IL-1β, IL-6, IL-17A, and IL-23—were assessed. Levels of lipid peroxidation and reactive oxygen species (ROS) were quantified. Antioxidant status as a measure of activities of antioxidant enzymes—catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD)—was determined.

Results

Punicalagin effectively improved antioxidant status and decreased lipid peroxidation, ROS production, and serum levels of inflammatory mediators. NF-κB pathway and JAK2/STAT3 signaling were significantly (p < 0.05) downregulated. Punicalagin effectively regulated the production of cytokines by the Th17 cells and the IL-17A/IL-23 axis.

Conclusion

The observations suggest that punicalagin exerts a protective role in AS via reducing oxidative stress and regulating NF-κB/TH17/JAK2/STAT3 signal. Punicalagin thus could be explored further as a potent candidate compound in the treatment of AS.

Punicalagin Protects Diabetic Nephropathy by Inhibiting Pyroptosis Based on TXNIP/NLRP3 Pathway

Diabetic nephropathy is a diabetic complication caused by chronic inflammation. As the primary polyphenol in pomegranate, punicalagin is believed to have significant anti-inflammatory properties. In this study, we established a mice model for diabetes induced by high-fat diet (HFD)/ streptozotocin (STZ) to verify the protective effect of punicalagin in vivo. The results show that the blood urea nitrogen (BUN), serum creatinine (CREA), and the urine albumin to creatinine ratio (UACR) were significantly decreased in diabetic mice after punicalagin intervention, and the symptoms of glomerular interstitial hyperplasia and glomerular hypertrophy were alleviated. Pyroptosis is an essential manner of programmed cell death in the inflammatory response; the expression of pyroptosis-related proteins such as interleukin-1 (IL-1β), cysteinyl aspartate-specific protease-1 (caspase-1), gasdermin D (GSDMD), and nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain containing protein 3 (NLRP3) was decreased in our study, which proved that the administration of punicalagin for eight weeks can significantly inhibit pyroptosis in mice. In addition, punicalagin reduced high glucose-mediated protein expressions of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) and alleviated mitochondria damage. Low expression of NOX4 inhibits the dissociation of thioredoxin (Trx) and thioredoxin-interacting protein (TXNIP) and the suppression of NLRP3 inflammasome activation. To summarize, our study provided evidence that punicalagin can alleviate diabetic nephropathy, and the effect is associated with downregulating the expression of NOX4, inhibiting TXNIP/NLRP3 pathway-mediated pyroptosis, suggesting its therapeutic implications for complications of diabetes.

Protective Effects of Punicalagin on Osteoporosis by Inhibiting Osteoclastogenesis and Inflammation via the NF-κB and MAPK Pathways

Postmenopausal osteoporosis is a worldwide disease characterized by reduced bone mineral density and increased fracture risk. Inflammatory bone loss due to excessive osteoclast bone resorption is significant in the pathogenesis and development of osteoporosis. Punicalagin (PUN) is a pomegranate fruit derivative and has potential anti-inflammatory effects. However, the effect of PUN on osteoporotic bone loss has yet to be clarified. In this study, we investigated the effect of PUN on RANKL-induced osteoclast formation and bone resorption in vitro, as well as its potential therapeutic effect on ovariectomized-induced bone loss in vivo. PUN was demonstrated to suppress osteoclast formation and bone resorptive function dose-dependently, while osteoclast-specific genes were also downregulated by PUN. In vivo micro-CT and histopathological staining showed that the OVX procedure led to significant bone loss characterized by decreased bone parameters and increased osteoclast numbers, while PUN treatment dramatically prevented these changes. Furthermore, PUN treatment effectively inhibited proinflammatory cytokine expression in vitro. Mechanistically, PUN maintained bone mass via suppressing nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathway activation. Collectively, our observations provide evidence that PUN is a potential candidate for the treatment of osteoporosis.

PGE2 increases inflammatory damage in Escherichia coli-infected bovine endometrial tissue in vitro via the EP4-PKA signaling pathway

Endometritis is the most common bovine uterine disease following parturition. The role of prostaglandin E2 (PGE2) in the regulation of endometrial inflammation and repair is well understood. Excess PGE2 is also generated in multiple inflammatory diseases, including endometritis. However, it remains unclear whether PGE2 is associated with pathogen-induced inflammatory damage to the endometrium. To clarify the role of PGE2 in pathogen-induced inflammatory damage, this study evaluated the production of PGE2, inflammatory factors, and damage-associated molecular patterns (DAMPs) in cultured Escherichia coli-infected bovine endometrial tissue. PGE2 production was significantly higher in E. coli-infected tissue, and in E. coli-infected tissue treated with 15-prostaglandin dehydrogenase (15-PGDH) inhibitors, as compared to uninfected tissue. Phospholipase A2 (PLA2), cyclooxygenase-2 (COX-2), and microsomal prostaglandin E synthase-1 (mPGES-1) were also upregulated in E. coli-infected tissue, while concentrations of arachidonic acid (AA), leukotrienes, DAMPs, and other proinflammatory factors increased. The accumulation of PGE2 clearly damaged the cultured tissue. Treatment with the COX-2, mPGES-1, EP4, and protein kinase A (PKA) inhibitors decreased the production of PGE2, inflammatory factors, and DAMPs, simultaneously alleviating the E. coli-induced endometrial tissue damage. Therefore, the PGE2 that was generated by COX-2 and mPGES-1 accumulated, and this pathogenic PGE2 increased inflammatory damage by upregulating inflammatory factors and DAMPs in E. coli-infected bovine endometrial tissue. This upregulation of inflammatory factors and DAMPs might be regulated by the EP4-PKA signaling pathway.

Different effects of cortisol on pro-inflammatory gene expressions in LPS-, heat-killed E.coli-, or live E.coli-stimulated bovine endometrial epithelial cells

Background

Bacterial infections are common in postpartum dairy cows. Cortisol level has been observed to increase in dairy cows during peripartum period, and is associated with the endometrial innate immunity against pathogens like E.coli. However, the mechanism underlying how cortisol regulates E.coli-induced inflammatory response in bovine endometrial epithelial cells (BEEC) remains elusive.

Results

Cortisol decreased the expressions of IL1β, IL6, TNF-α, IL8, and TLR4 mRNA in BEEC treated with LPS or heat-killed E.coli, but up-regulated these gene expressions in BEEC stimulated by live E.coli.

Conclusion

Cortisol exerted the anti-inflammatory action on LPS- or heat-killed E.coli-stimulated BEEC, but the pro-inflammatory action on live E.coli-induced BEEC.

A New Possible Mechanism by Which Punicalagin Protects against Liver Injury Induced by Type 2 Diabetes Mellitus: Upregulation of Autophagy via the Akt/FoxO3a Signaling Pathway

The aim of this study was to investigate the protective effect of punicalagin (PU), which is a main component of pomegranate polyphenols, against liver injury induced by Type 2 diabetes mellitus (T2DM) and to explore the molecular mechanism based on autophagy in vivo and in vitro. In T2DM mice, we found that PU significantly improved liver histology, reversed serum biochemical abnormalities, and increased the autophagosome number in the liver. In HepG2 cells cultured in a high-glucose environment, PU upregulated the glucose uptake level. Both in vivo and in vitro, PU upregulated the expression of autophagy-related proteins, such as LC3b and p62, and reduced the phosphorylated Akt/total Akt and phosphorylated FoxO3a/total FoxO3a protein ratios, and these effects were enhanced by LY294002 (a PI3K/Akt inhibitor). In summary, our current findings suggest that PU protects against liver injury induced by T2DM by restoring autophagy through the Akt/FoxO3a signaling pathway.

Catalpol ameliorates LPS-induced endometritis by inhibiting inflammation and TLR4/NF-κB signaling

Catalpol is the main active ingredient of an extract from Radix rehmanniae, which in a previous study showed a protective effect against various types of tissue injury. However, a protective effect of catalpol on uterine inflammation has not been reported. In this study, to investigate the protective mechanism of catalpol on lipopolysaccharide (LPS)-induced bovine endometrial epithelial cells (bEECs) and mouse endometritis, in vitro and in vivo inflammation models were established. The Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway and its downstream inflammatory factors were detected by enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), western blot (WB), and immunofluorescence techniques. The results from ELISA and qRT-PCR showed that catalpol dose-dependently reduced the expression of pro-inflammatory cytokines such as tumor necrosis factor α (TNF-α), interleukin (IL)-1β, and IL-6, and chemokines such as C-X-C motif chemokine ligand 8 (CXCL8) and CXCL5, both in bEECs and in uterine tissue. From the experimental results of WB, qRT-PCR, and immunofluorescence, the expression of TLR4 and the phosphorylation of NF-κB p65 were markedly inhibited by catalpol compared with the LPS group. The inflammatory damage to the mouse uterus caused by LPS was greatly reduced and was accompanied by a decline in myeloperoxidase (MPO) activity. The results of this study suggest that catalpol can exert an anti-inflammatory impact on LPS-induced bEECs and mouse endometritis by inhibiting inflammation and activation of the TLR4/NF-κB signaling pathway.

LP induced/mediated PGE2 synthesis through activation of the ERK/NF-κB pathway contributes to inflammatory damage triggered by Escherichia coli-infection in bovine endometrial tissue

The bovine endometrium is constantly challenged with pathogenic bacteria, especially with Escherichia coli. In previous studies, we showed that prostaglandin E₂ (PGE₂) synthesis was increased in E. coli-infected bovine endometrial tissue, which promoted the development of inflammatory damage. However, the molecular mechanism underlying this accumulation of PGE₂ remained undefined. Lipoprotein (LP) is one of critical outer membrane protein in E. coli, which regulates inflammatory response. In this study, we determined the role of LP in PGE₂ accumulation in bovine endometrial tissue by infecting the tissue with wild endometrial pathogenic E. coli and E. coli LP deletion mutant (JE5505) strains. We demonstrate that JE5505 was less effective than pathogenic E. coli in inducing the production of PGE_2,IL-6, TNF-α, HMGB-1, and HABP1 and that the induction of cytokines was dependent on the activation of MAPKs, as revealed by rapid phosphorylation of ERK1/2/NF-κB in the endometrial tissues, furthermore, LP also induced PGE₂ synthessis and cytokine secretion. Additionally, ERK and NF-κB inhibitors significantly inhibited PGE₂ production and cytokine secretion and reduced or attenuated tissue damage in JE5505-infected and LP induced endometrial tissues. What is more important, we reported PGE₂ introduction increased the expression of pro-inflammatory factors and DAMPs in E. coli-infected bovine endometrial tissue. Taken together, these results indicate that LP is involved in the accumulation of PGE₂ through the activation of the ERK/NF-κB pathway that induces the production of pro-inflammatory factors and damage-associated molecular patterns (DAMPs) in E. coli-infected bovine endometrial tissue. These results should help in better understanding and management of postpartum inflammatory diseases in dairy cows.

Ureaplasma urealyticum-derived lipid-associated membrane proteins introduce IL-6, IL-8, and TNF-α cytokines into human amniotic epithelial cells via Toll-like receptor 2

OBJECTIVE

The purpose of this study was to determine the role of Ureaplasma urealyticum-derived lipid-associated membrane proteins (LAMPs) in the host innate immune system, specifically their effect on Toll-like receptors (TLRs).

METHODS

LAMPs were derived from U. urealyticum strains, and human amniotic epithelial cells (HAECs) were isolated from healthy full-term placentas. Cytokine concentrations were determined by enzyme-linked immunosorbent assay (ELISA) and TLR2 mRNA by real-time PCR. Expression of TLR2 was confirmed by Western blotting and immunohistochemistry.

RESULTS

LAMPs induced HAECs to produce inflammatory cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α. Cytokine production was reduced after blocking TLR2 using TLR2 inhibitor (anti-hTLR2-IgA).

CONCLUSIONS

LAMPs isolated from U. urealyticum induced TLR2-dependent up-regulation of inflammatory genes and cytokines in HAECs.

Structural uterine changes in postpartum endometritis in cows

AIM

The purpose of this work was to study the dynamics of structural manifestations of acute cases of postpartum endometritis in cows.

MATERIALS AND METHODS

The light and electron microscopy methods were used when studying structural changes in the endometrium in case of postpartum endometritis in seven cows. Sections of endometrial specimens for light microscopy, 5-7 µm thick, were stained with hematoxylin and eosin and also by Van Gieson's. For electron microscopy, semi-thin sections were stained with Azur-2 in combination with basic fuchsin, as well as contrasting by lead citrate and uranyl acetate.

RESULTS

As a result of the study, we have established the following: Necrobiosis of the epithelial layer of the mucosa, cellular infiltration with shaped elements of blood in the functional layer, swelling of the cells of the uterine gland, and single microbial cells on the surface of the mucosa. We have noted edema of the stroma of the functional layer of the endometrium, swelling of the epithelial layer of the endometrial mucosa, and swelling of fibroblastic and lymphoid cells. Ultrastructural changes in endometrial cells in case of acute postpartum endometritis in cows are accompanied by the destruction of microvilli on the apical surface of the epithelium, an abundance of coccal microflora on the surface of the epithelium, necrobiosis of epithelial cells, and partial edema of the nucleus, and cytoplasm of the histiocyte.

CONCLUSION

We had established that acute purulent-catarrhal dystrophic processes were observed in the structural organization of the endometrium. In the depth of catarrhal mucus on the surface of the endometrium, there was an abundance of bacterial flora, with diplococci being prevalent. In ultrastructural organization of the endometrium, we observed deep dystrophic and necrobiotic processes in the parenchyma and endometrial stroma, as well as exudative processes with a change in the integrity of the microcirculatory bed. Thus, to prevent an inflammatory process from turning into a latent form, it is necessary to detect acute postpartum endometritis promptly using diagnostic methods taking into account the obtained parameters of the dynamics of structural changes in the uterine tissues.