Complicated urinary tract infection is associated with uroepithelial expression of proinflammatory protein S100A8

PATHWAYS ASSOCIATED WITH POSITIVE SEPSIS SURVIVAL OUTCOMES IN AFRICAN AMERICAN/BLACK AND NON-HISPANIC WHITE PATIENTS WITH URINARY TRACT INFECTION

ABSTRACT

Urinary tract infections (UTIs) are a common cause of sepsis worldwide. Annually, more than 60,000 US deaths can be attributed to sepsis secondary to UTIs, and African American/Black adults have higher incidence and case-fatality rates than non-Hispanic White adults. Molecular-level factors that may help partially explain differences in sepsis survival outcomes between African American/Black and Non-Hispanic White adults are not clear. In this study, patient samples (N = 166) from the Protocolized Care for Early Septic Shock cohort were analyzed using discovery-based plasma proteomics. Patients had sepsis secondary to UTIs and were stratified according to self-identified racial background and sepsis survival outcomes. Proteomics results suggest patient heterogeneity across mechanisms driving survival from sepsis secondary to UTIs. Differentially expressed proteins (n = 122, false discovery rate-adjusted P < 0.05) in Non-Hispanic White sepsis survivors were primarily in immune system pathways, while differentially expressed proteins (n = 47, false discovery rate-adjusted P < 0.05) in African American/Black patients were mostly in metabolic pathways. However, in all patients, regardless of racial background, there were 16 differentially expressed proteins in sepsis survivors involved in translation initiation and shutdown pathways. These pathways are potential targets for prognostic intervention. Overall, this study provides information about molecular factors that may help explain disparities in sepsis survival outcomes among African American/Black and Non-Hispanic White patients with primary UTIs.

Distribution pattern of local immune cells within the lower urinary tract of male sheep lambs

The local immunity of the lower urinary tract (LUT) is often presumed to influence the development of ascending infections and local inflammation. Due to small ruminants being at a higher risk of developing obstructive urolithiasis after early castration, a relationship is expected to exist between disturbed local immunity, castration and disease. However, the underlying pathophysiology and histological correlation of this assumption are unknown. This study examines the local cellular immunity of the LUT in male lambs with respect to castration status or a recent history of obstructive urolithiasis. Various tissue samples were taken and examined. The sample consisted of 34 male lambs, aged six months (n = 11 early and n = 11 late castration; n = 12 intact) and eight rams that had undergone necropsy due to fatal outcome after obstructive urolithiasis. Immunohistochemical stainings for CD3-T-cells, CD79α-B-cells and MAC 387-macrophages were performed and compared among the groups. Whereas no global group differences were evident, significant differences were found for the localizations (P = 0.002) with a significant interaction between group and localization (P = 0.004). The immunohistochemical results suggest that castration did not affect the cell number, but did have an effect on the distribution pattern of local T-cells within the urethra. In the urolithiasis cases, a reduction of CD3-positive cells along the middle part of the urethra was noticeable.

The iron hand of uropathogenic Escherichia coli: the role of transition metal control in virulence

The role of iron as a critical nutrient in pathogenic bacteria is widely regarded as having driven selection for iron acquisition systems among uropathogenic Escherichia coli (UPEC) isolates. Carriage of multiple transition metal acquisition systems in UPEC suggests that the human urinary tract manipulates metal-ion availability in many ways to resist infection. For siderophore systems in particular, recent studies have identified new roles for siderophore copper binding as well as production of siderophore-like inhibitors of iron uptake by other, competing bacterial species. Among these is a process of nutritional passivation of metal ions, in which uropathogens access these vital nutrients while simultaneously protecting themselves from their toxic potential. Here, we review these new findings within the current understanding of UPEC transition metal acquisition.

Disruption of the S41 peptidase gene in mycoplasma mycoides capri impacts proteome profile, H(2)O(2) production, and sensitivity to heat shock

Members of the Mycoplasma mycoides cluster are among the most virulent of the mycoplasmas, causing worldwide economically significant diseases of cattle and goats. A distinguishing phenotype among the members of the cluster is the ability to degrade casein. The MMCAP2_0241 gene, an S41 peptidase, confers the proteolytic phenotype in Mycoplasma mycoides subsp. capri GM12. In order to determine the impact of disruption of the gene, we used differential proteome profiling to compare the M. mycoides subsp. capri wild type with a mutant lacking the proteolytic phenotype. Disruption of MMCAP2_0241 resulted in altered phenotypes reminiscent of M. mycoides subsp. mycoides SC and had significant impacts on the proteome profile of the microbe. The mutant exhibited increased production of hydrogen peroxide, decreased lactate dehydrogenase activity, and increased sensitivity to heat shock.

Cytokines in the host response to Candida vaginitis: Identifying a role for non-classical immune mediators, S100 alarmins

Vulvovaginal candidiasis (VVC), caused by Candida albicans, affects a significant number of women during their reproductive years. More than two decades of research have been focused on the mechanisms associated with susceptibility or resistance to symptomatic infection. Adaptive immunity by Th1-type CD4(+) T cells and downstream cytokine responses are considered the predominant host defense mechanisms against mucosal Candida infections. However, numerous clinical and animal studies have indicated no or limited protective role of cells and cytokines of the Th1 or Th2 lineage against vaginal infection. The role for Th17 is only now begun to be investigated in-depth for VVC with results already showing significant controversy. On the other hand, a clinical live-challenge study and an established animal model have shown that a symptomatic condition is intimately associated with the vaginal infiltration of polymorphonuclear leukocytes (PMNs) but with no effect on vaginal fungal burden. Subsequent studies identified S100A8 and S100A9 alarmins as key chemotactic mediators of the acute PMN response. These chemotactic danger signals appear to be secreted by vaginal epithelial cells upon interaction and early adherence of Candida. Thus, instead of a putative immunodeficiency against Candida involving classical immune cells and cytokines of the adaptive response, the pathological inflammation in VVC is now considered a consequence of a non-productive innate response initiated by non-classical immune mediators.

Proteomics and pathway analyses of the milk fat globule in sheep naturally infected by Mycoplasma agalactiae provide indications of the in vivo response of the mammary epithelium to bacterial infection

Milk fat globules (MFGs) are vesicles released in milk as fat droplets surrounded by the endoplasmic reticulum and apical cell membranes. During formation and apocrine secretion by lactocytes, various amounts of cytoplasmic crescents remain trapped within the released vesicle, making MFGs a natural sampling mechanism of the lactating cell contents. With the aim of investigating the events occurring in the mammary epithelium during bacterial infection, the MFG proteome was characterized by two-dimensional difference gel electrophoresis (2-D DIGE), SDS-PAGE followed by shotgun liquid chromatography-tandem mass spectrometry (GeLC-MS/MS), label-free quantification by the normalized spectral abundance factor (NSAF) approach, Western blotting, and pathway analysis, using sheep naturally infected by Mycoplasma agalactiae. A number of protein classes were found to increase in MFGs upon infection, including proteins involved in inflammation and host defense, cortical cytoskeleton proteins, heat shock proteins, and proteins related to oxidative stress. Conversely, a strikingly lower abundance was observed for proteins devoted to MFG metabolism and secretion. To our knowledge, this is the first report describing proteomic changes occurring in MFGs during sheep infectious mastitis. The results presented here offer new insights into the in vivo response of mammary epithelial cells to bacterial infection and open the way to the discovery of protein biomarkers for monitoring clinical and subclinical mastitis.

Ureaplasma parvum infection alters filamin A dynamics in host cells

Background

Ureaplasmas are among the most common bacteria isolated from the human urogenital tract. Ureaplasmas can produce asymptomatic infections or disease characterized by an exaggerated inflammatory response. Most investigations have focused on elucidating the pathogenic potential of Ureaplasma species, but little attention has been paid to understanding the mechanisms by which these organisms are capable of establishing asymptomatic infection.

Methods

We employed differential proteome profiling of bladder tissues from rats experimentally infected with U. parvum in order to identify host cell processes perturbed by colonization with the microbe. Tissues were grouped into four categories: sham inoculated controls, animals that spontaneously cleared infection, asymptomatic urinary tract infection (UTI), and complicated UTI. One protein that was perturbed by infection (filamin A) was used to further elucidate the mechanism of U. parvum-induced disruption in human benign prostate cells (BPH-1). BPH-1 cells were evaluated by confocal microscopy, immunoblotting and ELISA.

Results

Bladder tissue from animals actively colonized with U. parvum displayed significant alterations in actin binding proteins (profilin 1, vinculin, α actinin, and filamin A) that regulate both actin polymerization and cell cytoskeletal function pertaining to focal adhesion formation and signal transduction (Fisher's exact test, P < 0.004; ANOVA, P < 0.02). This phenomenon was independent of clinical profile (asymptomatic vs. complicated UTI). We selected filamin A as a target for additional studies. In the BPH-1 model, we confirmed that U. parvum perturbed the regulation of filamin A. Specifically, infected BPH-1 cells exhibited a significant increase in filamin A phosphorylated at serine²¹⁵² (P ≤ 0.01), which correlated with impaired proteolysis of the protein and its normal intracellular distribution.

Conclusion

Filamin A dynamics were perturbed in both models of infection. Phosphorylation of filamin A occurs in response to various cell signaling cascades that regulate cell motility, differentiation, apoptosis and inflammation. Thus, this phenomenon may be a useful molecular marker for identifying the specific host cell pathways that are perturbed during U. parvum infection.

Porcine S100A8 and S100A9: molecular characterizations and crucial functions in response to Haemophilus parasuis infection

S100 calcium-binding protein A8 (S100A8) and S100 calcium-binding protein A9 (S100A9) are pivotal mediators of inflammatory and protective anti-infection responses for the mammalian host. In this study, we present the molecular cloning of porcine S100A8 (pS100A8) and porcine S100A9 (pS100A9). Both genes comprise 3 exons and 2 introns and are located on pig chromosome 4q21-q23 (closely linked to SW512). Homology comparison to other mammalian species affirmed that critical functional amino acids for post-transcriptional modification, inflammatory regulation, and formation of heterodimeric complexes exist in pS100A8 and pS100A9. Under normal conditions, both genes are preferentially expressed in porcine immune or immune-related organs, e.g., bone marrow, spleen, lymph nodes, and lung. Upon stimulation in porcine whole blood cultures with LPS or Poly(I:C), they are dramatically induced. Interestingly, the maximum increase of mRNA levels in blood cultures of Meishan pigs is significantly greater than that in Duroc pigs. We previously showed that pS100A8 and pS100A9 mRNA were up-regulated following Haemophilus parasuis (HPS) infection. We herein further confirm their up-regulation at the protein level in multiple HPS infected tissues (spleen, lung and liver). Functional cluster and network analysis based on our previous microarray data discovered that CEBPB may be one of the key transcription factors. A pS100A8/pS100A9-CASP3-SLC1A2 pathway regulating lipid metabolism was found. Both of their pro- and anti-inflammatory functions in response to HPS infection are highlighted.

The role of Genital Mycoplasmas for the development of urogenital pathology in children

Modern data of the epidemiological aspects and clinical peculiarities of inflammatory urogenital diseases caused by genital mycoplasmas in children are represented. Contemporary methods of laboratory diagnostics and therapy for inflammatory urogenital diseases caused by genital mycoplasmas are described.

S100A8/A9 is not involved in host defense against murine urinary tract infection

Background

Inflammation is commonly followed by the release of endogenous proteins called danger associated molecular patterns (DAMPs) that are able to warn the host for eminent danger. S100A8/A9 subunits are DAMPs that belong to the S100 family of calcium binding proteins. S100A8/A9 complexes induce an inflammatory response and their expression correlates with disease severity in several inflammatory disorders. S100A8/A9 promote endotoxin- and Escherichia (E.) coli-induced sepsis showing its contribution in systemic infection. The role of S100A8/A9 during a local infection of the urinary tract system caused by E. coli remains unknown.

Methodology/Principal Findings

We investigated the contribution of S100A8/A9 in acute urinary tract infection (UTI) by instilling 2 different doses of uropathogenic E. coli transurethrally in wild type (WT) and S100A9 knockout (KO) mice. Subsequently, we determined bacterial outgrowth, neutrophilic infiltrate and inflammatory mediators in bladder and kidney 24 and 48 hours later. UTI resulted in a substantial increase of S100A8/A9 protein in bladder and kidney tissue of WT mice. S100A9 KO mice displayed similar bacterial load in bladder or kidney homogenate compared to WT mice using 2 different doses at 2 different time points. S100A9 deficiency had little effect on the inflammatory responses to E. Coli-induced UTI infection, as assessed by myeloperoxidase activity in bladder and kidneys, histopathologic analysis, and renal and bladder cytokine concentrations.

Conclusions

We show that despite high S100A8/A9 expression in bladder and kidney tissue upon UTI, S100A8/A9 does not contribute to an effective host response against E. Coli in the urinary tract system.