Cytokine profiles of umbilical cord blood mononuclear cells upon in vitro stimulation with lipopolysaccharides of different vaginal gram-negative bacteria

An altered gut microbiome in pre-eclampsia: cause or consequence

Hypertensive disorders of pregnancy, including pre-eclampsia, are a leading cause of serious and debilitating complications that affect both the mother and the fetus. Despite the occurrence and the health implications of these disorders there is still relatively limited evidence on the molecular underpinnings of the pathophysiology. An area that has come to the fore with regard to its influence on health and disease is the microbiome. While there are several microbiome niches on and within the body, the distal end of the gut harbors the largest of these impacting on many different systems of the body including the central nervous system, the immune system, and the reproductive system. While the role of the microbiome in hypertensive disorders, including pre-eclampsia, has not been fully elucidated some studies have indicated that several of the symptoms of these disorders are linked to an altered gut microbiome. In this review, we examine both pre-eclampsia and microbiome literature to summarize the current knowledge on whether the microbiome drives the symptoms of pre-eclampsia or if the aberrant microbiome is a consequence of this condition. Despite the paucity of studies, obvious gut microbiome changes have been noted in women with pre-eclampsia and the individual symptoms associated with the condition. Yet further research is required to fully elucidate the role of the microbiome and the significance it plays in the development of the symptoms. Regardless of this, the literature highlights the potential for a microbiome targeted intervention such as dietary changes or prebiotic and probiotics to reduce the impact of some aspects of these disorders.

Neonatal immune cells have heightened responses following in-utero exposure to chorioamnionitis or COVID-19

BACKGROUND

Chorioamnionitis alters neonatal immune responses. Gestational COVID-19 infection is associated with adverse pregnancy outcomes, but its impact on neonatal immunity is unclear. We hypothesized that gestational COVID-19 exposure would result in exaggerated neonatal immune responses, similar to chorioamnionitis-exposed neonates.

METHODS

Term umbilical cord blood mononuclear cells (CBMCs) were isolated from neonates exposed to chorioamnionitis, gestational COVID-19 or unexposed controls. CBMCs were cultured and stimulated with heat-killed Escherichia coli, Streptococcus agalactiae or Staphylococcus epidermidis. A multiplexed protein assay was used to measure cytokine levels in cell culture supernatants and flow cytometry was used to evaluate cellular-level cytokine expression.

RESULTS

Both chorioamnionitis-exposed and COVID-19 exposed CBMCs demonstrated upregulation of IL-1β and IL-6 compared to unexposed CBMCs, while only COVID-19 exposure resulted in IL-8 upregulation. There were no differences between chorioamnionitis-exposed and COVID-19 exposed CBMCs when these groups were directly compared. Flow cytometry demonstrated immune cell subset specific differences in cytokine expression between the exposure groups.

CONCLUSION

The fetal/neonatal response to maternal inflammation differed based on immune cell subset and etiology of inflammation, but the global neonatal cytokine responses were similar between exposure groups. This suggests that targeting perinatal inflammation rather than the specific etiology may be a possible therapeutic approach.

IMPACT

Neonatal immune cells have similar pathogen-associated global cytokine responses, but different cell-level immune responses, following in-utero exposure to chorioamnionitis or COVID-19. This is the first study to directly compare immune responses between neonates exposed to chorioamnionitis and COVID-19. This suggests that the fetal/neonatal cellular response to perinatal inflammation differs based on the etiology and severity of maternal inflammation, but still results in a similar overall inflammatory profile regardless of the cause of perinatal inflammation.

Clinical Characteristics of Uncomplicated Acute Pyelonephritis Caused by Escherichia coli and Klebsiella pneumoniae

INTRODUCTION

This study compared the clinical characteristics and antimicrobial susceptibility of uncomplicated acute pyelonephritis (APN) caused by Escherichia coli and Klebsiella pneumoniae.

METHODS

We retrospectively reviewed the medical records of patients with uncomplicated APNs caused by E. coli and K. pneumoniae admitted to Keimyung University Dongsan Hospital between February 2014 and December 2021.

RESULTS

We enrolled 497 patients (372 with E. coli infection, 125 with K. pneumoniae infection). Male, healthcare-associated infection, solid tumors, liver cirrhosis, chronic renal disease, solid organ transplantation, and antibiotic usage within the last 3 months were more strongly associated with K. pneumoniae uncomplicated APNs than with E. coli. Bacteremia and fever occurred more frequently in E. coli uncomplicated APNs. Antimicrobial resistance rates to piperacillin/tazobactam and carbapenem were higher in K. pneumoniae. Antimicrobial resistance rates to aztreonam and ciprofloxacin were lower in K. pneumoniae. Thirty-day mortality was more observed in K. pneumoniae group in univariate analysis, but this difference was not observed after adjustment. Male sex, ultimately fatal disease in McCabe, and prior antibiotic use within 3 months were more associated with K. pneumoniae.

CONCLUSIONS

Male, underlying diseases, and prior antibiotic use was more associated with K. pneumoniae. Further study will be needed that microbiome of each situation and the related with the distribution of the strains.

Emerging role of toll-like receptors signaling and its regulators in preterm birth: a narrative review

INTRODUCTION

Despite intensive research, preterm birth (PTB) rates have not decreased significantly in recent years due to a lack of understanding of the underlying causes and insufficient treatment options for PTB. We are committed to finding promising biomarkers for the treatment of PTB.

METHODS

An extensive search of the literature was conducted with MEDLINE/PubMed, and in total, 151 studies were included and summarized in the present review.

RESULTS

Substantial evidence supports that the infection and/or inflammatory cascade associated with infection is an early event in PTB. Toll-like receptor (TLR) is a prominent pattern recognition receptor (PRR) found on both immune and non-immune cells, including fetal membrane cells. The activation of TLR downstream molecules, followed by TLR binding to its ligand, is critical for infection and inflammation, leading to the involvement of the TLR signaling pathway in PTB. TLR ligands are derived from microbial components and molecules released by damaged and dead cells. Particularly, TLR4 is an essential TLR because of its ability to recognize lipopolysaccharide (LPS). In this comprehensive overview, we discuss the role of TLR signaling in PTB, focus on numerous host-derived genetic and epigenetic regulators of the TLR signaling pathway, and cover ongoing research and prospective therapeutic options for treating PTB by inhibiting TLR signaling.

CONCLUSION

This is a critical topic because TLR-related molecules and mechanisms may enable obstetricians to better understand the physiological changes in PTB and develop new treatment and prevention strategies.

Induction of Angiogenesis by Genetically Modified Human Umbilical Cord Blood Mononuclear Cells

Stimulating the process of angiogenesis in treating ischemia-related diseases is an urgent task for modern medicine, which can be achieved through the use of different cell types. Umbilical cord blood (UCB) continues to be one of the attractive cell sources for transplantation. The goal of this study was to investigate the role and therapeutic potential of gene-engineered umbilical cord blood mononuclear cells (UCB-MC) as a forward-looking strategy for the activation of angiogenesis. Adenovirus constructs Ad-VEGF, Ad-FGF2, Ad-SDF1α, and Ad-EGFP were synthesized and used for cell modification. UCB-MCs were isolated from UCB and transduced with adenoviral vectors. As part of our in vitro experiments, we evaluated the efficiency of transfection, the expression of recombinant genes, and the secretome profile. Later, we applied an in vivo Matrigel plug assay to assess engineered UCB-MC's angiogenic potential. We conclude that hUCB-MCs can be efficiently modified simultaneously with several adenoviral vectors. Modified UCB-MCs overexpress recombinant genes and proteins. Genetic modification of cells with recombinant adenoviruses does not affect the profile of secreted pro- and anti-inflammatory cytokines, chemokines, and growth factors, except for an increase in the synthesis of recombinant proteins. hUCB-MCs genetically modified with therapeutic genes induced the formation of new vessels. An increase in the expression of endothelial cells marker (CD31) was revealed, which correlated with the data of visual examination and histological analysis. The present study demonstrates that gene-engineered UCB-MC can be used to stimulate angiogenesis and possibly treat cardiovascular disease and diabetic cardiomyopathy.

The Molecular and Histopathological Assessment of Inflammatory Status in Very and Extremely Premature Infants: A Prospective Study

Prematurity comes with a varying range of complications, implying a high prevalence of complications and mortality and depending on the severity of prematurity and the sustained inflammation among these infants, which recently sparked an important scientific interest. The primary objective of this prospective study was to establish the degree of inflammation in very (VPIs) and extremely preterm infants (EPIs) in association with the histology findings of the umbilical cord (UC), while the secondary objective was to study the inflammatory markers in the neonates' blood as predictors of fetal inflammatory response (FIR). A total of thirty neonates were analyzed, ten of them being born extremely premature (<28 weeks of gestation) and twenty very premature (28-32 weeks of gestation). The EPIs had considerably higher levels of IL-6 at birth than VPIs (638.2 pg/mL vs. 151.1 pg/mL). The CRP levels at delivery did not vary substantially across groups; however, after days, the EPIs had significantly higher CRP levels (11.0 mg/dL vs. 7.2 mg/dL). In contrast, the LDH was considerably higher in the extremely preterm infants at birth and four days after birth. Surprisingly, the proportions of infants with pathologically increased inflammatory markers did not differ between the EPIs and VPIs. The LDH increased considerably in both groups, although the CRP levels increased exclusively among the VPIs. The stage of inflammation in the UC did not vary substantially between the EPIs and VPIs. The majority of infants were identified with Stage 0 UC inflammation (40% in EPI vs. 55% in VPIs). There was a substantial correlation link between gestational age and newborn weight and a significant inverse correlation among gestational age and IL-6 and LDH levels. There was a strong negative association between weight and IL-6 (rho = -0.349) and LDH (rho = -0.261). The stage of the UC inflammation demonstrated a statistically significant direct connection with IL-6 (rho = 0.461) and LDH (rho = 0.293), but none with the CRP. Further studies involving a bigger population size of preterm newborns are required to validate the findings and analyze more inflammatory markers, while prediction models on inflammatory markers that are measured expectantly, before the onset of preterm labor, need to be created.

Vancomycin-induced gut microbiota dysbiosis aggravates allergic rhinitis in mice by altered short-chain fatty acids

OBJECTIVE

This study aims to explore how gut microbiota dysbiosis affects allergic rhinitis (AR) and whether short-chain fatty acids (SCFAs) play a role in this process.

METHODS

A mouse gut microbiota dysbiosis model was established by adding vancomycin to drinking water for 2 weeks before ovalbumin (OVA) sensitization. Then an OVA-alum AR mouse model was established by intraperitoneal OVA injection followed by nasal excitation. Hematoxylin and eosin (H&E) staining was performed to observe pathological changes in nasal and colon tissues of AR mice. Serum levels of total-IgE, OVA-sIgE, IL-4, IL-5, IL-10, and TGF-β1 were measured. The composition and diversity of the mouse gut microbiota were observed by 16S rDNA sequencing. Levels of SCFAs in feces were determined using SCFA-targeted metabolomics. Sodium butyrate (NaB) was added daily to mice on a low-fiber basal diet 2 weeks before the first sensitization, until the end of the study.

RESULTS

After gut microbiota dysbiosis, serum levels of the total IgE, OVA-sIgE, IL-4, and IL-5 in AR mice were significantly increased, compared with the control group. The composition and diversity of gut microbiota were significantly altered after gut microbiota dysbiosis, with the fecal SCFAs significantly reduced as well. The reduced bacterial genera after gut microbiota dysbiosis, such as Ruminococcus and Lactobacillus, were significantly and positively correlated with SCFAs. In contrast, the increased genera in the Van group, such as Escherichia-Shigella and Klebsiella, were significantly negatively correlated with SCFAs in feces. NaB treatment significantly reduced total-IgE, OVA-sIgE, IL-4, and IL-5 levels in serum, and inflammatory infiltration of the nasal and colon mucosa. In addition, serum levels of IL-10 and TGF-β1 increased significantly after NaB treatment. Foxp3 protein in the colon was upregulated considerably after NaB intervention.

CONCLUSION

Vancomycin-induced gut microbiota dysbiosis increased susceptibility and severity of AR, which is significantly related to reduced SCFA-producing bacteria, fecal SCFAs, and specific bacterial taxa. In addition, it was found that NaB alleviated low dietary fiber base-fed symptoms and immune status in AR mice.

Strategies for Biomaterial-Based Spinal Cord Injury Repair via the TLR4-NF-κB Signaling Pathway

The repair and motor functional recovery after spinal cord injury (SCI) has remained a clinical challenge. Injury-induced gliosis and inflammation lead to a physical barrier and an extremely inhibitory microenvironment, which in turn hinders the recovery of SCI. TLR4-NF-κB is a classic implant-related innate immunomodulation signaling pathway and part of numerous biomaterial-based treatment strategies for SCI. Numerous experimental studies have demonstrated that the regulation of TLR4-NF-κB signaling pathway plays an important role in the alleviation of inflammatory responses, the modulation of autophagy, apoptosis and ferroptosis, and the enhancement of anti-oxidative effect post-SCI. An increasing number of novel biomaterials have been fabricated as scaffolds and carriers, loaded with phytochemicals and drugs, to inhibit the progression of SCI through regulation of TLR4-NF-κB. This review summarizes the empirical strategies for the recovery after SCI through individual or composite biomaterials that mediate the TLR4-NF-κB signaling pathway.

A novel photoreactive DNA-binding dye for detecting viable Klebsiella pneumoniae in powdered infant formula

In addition to Cronobacter spp., Klebsiella pneumoniae is another opportunistic bacterial pathogen present in powdered infant formula (PIF) that can cause pneumonia, septicemia, and other diseases. In this study, a rapid and specific method based on a fluorescence probe was developed for detecting viable K. pneumoniae in PIF samples via the combination of recombinase-aided amplification (RAA) with thiazole orange monoazide (TOMA) dye (the TOMA-RAA assay hereafter). As a novel photosensitive DNA-intercalating dye, TOMA was used to penetrate bacterial cells, including both dead and viable cells, as verified by confocal laser scanning microscopy and fluorescent emission spectrometry. Importantly, the RAA assay exhibited good performance in detecting K. pneumoniae within 40 min at 39°C. Under optimal conditions, the TOMA-RAA assay can detect as low as 2.6 × 10³ cfu/mL of K. pneumoniae in pure culture and 2.3 × 10⁴ cfu/g of K. pneumoniae in spiked PIF sample. After 3 h of pre-enrichment, 3 × 10⁰ cfu/g of K. pneumoniae can be detected. Furthermore, the TOMA-RAA assay displayed an excellent anti-interference ability to nontarget bacteria. In short, the proposed method has great potential application for the rapid and accurate detection of viable K. pneumoniae in PIF.

The Role of 17β-Estrogen in Escherichia coli Adhesion on Human Vaginal Epithelial Cells via FAK Phosphorylation

Estrogen, the predominant sex hormone, has been found to be related to the occurrence of vaginal infectious diseases. However, its role in the occurrence and development of bacterial vaginitis caused by Escherichia coli is still unclear. The objective of this study was to investigate the role of 17β-estrogen in E. coli adhesion on human vaginal epithelial cells. The vaginal epithelial cell line VK2/E6E7 was used to study the molecular events induced by estrogen between E. coli and cells. An adhesion study was performed to evaluate the involvement of the estrogen-dependent focal adhesion kinase (FAK) activation with cell adhesion. The phosphorylation status of FAK and estrogen receptor α (ERα) upon estrogen challenge was assessed by Western blotting. Specific inhibitors for ERα were used to validate the involvement of ERα-FAK signaling cascade. The results showed that, following stimulation with 1,000 nM estrogen for 48 h, transient activation of ERα and FAK was observed, as was an increased average number of E. coli cells adhering to vaginal epithelial cells. In addition, estrogen-induced activation of ERα and FAK was inhibited by the specific inhibitor of ERα, especially when the inhibitor reached a 10 μM concentration and acted for 1 h, and a decrease in the number of adherent E. coli cells was observed simultaneously. However, this inhibitory effect diminished as the concentration of estrogen increased. In conclusion, FAK and ERα signaling cascades were associated with the increasing E. coli adherence to vaginal epithelial cells, which was promoted by a certain concentration of estrogen.

Perinatal Gram-Positive Bacteria Exposure Elicits Distinct Cytokine Responses In Vitro

During pregnancy, infections caused by the gram-positive bacteria Enterococcus faecalis (E. faecalis), Streptococcus agalacticae (S. agalacticae), and Staphylococcus aureus (S. aureus) are major reasons for preterm labor, neonatal prematurity, meningitis, or sepsis. Here, we propose cytokine responses to bacterial infections by the immature perinatal immune system as central players in the pathogenesis of preterm birth and neonatal sepsis. We aimed to close the gap in knowledge about such cytokine responses by stimulating freshly isolated umbilical blood mononuclear cells (UBMC) with lysates of E. faecalis, S. agalacticae, and S. aureus collected from pregnant women in preterm labor. Bacterial lysates and, principally, S. aureus and S. agalacticae distinctly triggered most of the eleven inflammatory, anti-inflammatory, TH1/TH2 cytokines, and chemokines quantified in UBMC culture media. Chemokines depicted the most robust induction. Among them, MIP-1β was further enhanced in UBMC from female compered to male newborn infants. Due to its stability and high levels, we investigated the diagnostic value of IL-8. IL-8 was critically upregulated in cord blood of preterm neonates suffering from infections compared to gestational age-matched controls. Our results provide novel clues about perinatal immunity, underscoring a potential value of IL-8 for the timely detection of infections and suggesting that MIP-1β constitutes an early determinant of sex-specific immunity, which may contribute, e.g., to male's vulnerability to preterm birth.

Host Innate Immune Responses to Acinetobacter baumannii Infection

Acinetobacter baumannii has emerged as a major threat to global public health and is one of the key human pathogens in healthcare (nosocomial and community-acquired)-associated infections. Moreover, A. baumannii rapidly develops resistance to multiple antibiotics and is now globally regarded as a serious multidrug resistant pathogen. There is an urgent need to develop novel vaccines and immunotherapeutics as alternatives to antibiotics for clinical management of A. baumannii infection. However, our knowledge of host immune responses to A. baumannii infection and the identification of novel therapeutic targets are significantly lacking. This review highlights the recent advances and critical gaps in our understanding how A. baumannii interacts with the host innate pattern-recognition receptors, induces a cascade of inflammatory cytokine and chemokine responses, and recruits innate immune effectors (such as neutrophils and macrophages) to the site of infection for effective control of the infection. Such knowledge will facilitate the identification of new targets for the design and development of effective therapeutics and vaccines to fight this emerging threat.

Short-chain fatty acids accompanying changes in the gut microbiome contribute to the development of hypertension in patients with preeclampsia

Preeclampsia (PE) is regarded as a pregnancy-associated hypertension disorder that is related to excessive inflammatory responses. Although the gut microbiota (GM) and short-chain fatty acids (SCFAs) have been related to hypertension, their effects on PE remain unknown. We determined the GM abundance and faecal SCFA levels by 16S ribosomal RNA (rRNA) sequencing and gas chromatography, respectively, using faecal samples from 27 patients with severe PE and 36 healthy, pregnant control subjects. We found that patients with PE had significantly decreased GM diversity and altered GM abundance. At the phylum level, patients with PE exhibited decreased abundance of Firmicutes albeit increased abundance of Proteobacteria; at the genus level, patients with PE had lower abundance of Blautia, Eubacterium_rectale, Eubacterium_hallii, Streptococcus, Bifidobacterium, Collinsella, Alistipes, and Subdoligranulum, albeit higher abundance of Enterobacter and Escherichia_Shigella. The faecal levels of butyric and valeric acids were significantly decreased in patients with PE and significantly correlated with the above-mentioned differential GM abundance. We predicted significantly increased abundance of the lipopolysaccharide (LPS)-synthesis pathway and significantly decreased abundance of the G protein-coupled receptor (GPCR) pathway in patients with PE, based on phylogenetic reconstruction of unobserved states (PICRUSt). Finally, we evaluated the effects of oral butyrate on LPS-induced hypertension in pregnant rats. We found that butyrate significantly reduced the blood pressure (BP) in these rats. In summary, we provide the first evidence linking GM dysbiosis and reduced faecal SCFA to PE and demonstrate that butyrate can directly regulate BP in vivo, suggesting its potential as a therapeutic agent for PE.