lncRNA PCAT1 might coordinate ZNF217 to promote CRC adhesion and invasion through regulating MTA2/MTA3/Snai1/E-cadherin signaling

LncRNA prostate cancer-associated transcript 1 (PCAT1) is a well-known oncogene, but the mechanisms of exosomes PCAT1 in colorectal cancer (CRC) remain largely unknown. Thus, the mechanisms of exosomes lncRNA PCAT1 were investigated. The expressions of exosomes lncRNA PCAT1 in tissues from stage 0-I and stage II-III CRC patients, and intestinal epithelial cell line FHC and two CRC cell lines, HT29 and HCT8 were measured by real-time quantitative PCR. The effects of lncRNA PCAT1 on adhesion and invasion of two CRC cell lines were investigated by cell-matrix adhesion and transwell assays. In addition, the target of PCAT1 (ZNF217) was validated using an RNA immune precipitation assay. Finally, the protein levels of MTA2, MTA3, SNAI1, and E-cadherin in normal participants, stage 0-I and stage II-III CRC patients, as well as two cell lines with stable ZNF217 knockdown were investigated by western blotting. The plasma exosomal lncRNA PCAT1 was found to be significantly increased in the CRC tissues and cell lines. In addition, lncRNA PCAT1 knockdown significantly inhibited the adhesion and invasion of HT29 and HCT8 cells. RIP assay results showed lncRNA PCAT1 could target ZNF217, and downregulation of lncRNA PCAT1 could decrease the protein expressions of ZNF217 in two CRC cells lines. Moreover, ZNF217 knockdown significantly decreased MTA2, MTA3, and SNAI1 expressions, but increased E-cadherin expressions in both CRC cells lines. Exosomal lncRNA PCAT1 can promote the adhesion and invasion of CRC cells, and PCAT1 overexpression may lead to ZNF217 upregulation that regulates EMT-related MTA2/MTA3/Snai1/E-cadherin signaling

Resistance-Nodulation-Cell Division (RND) Transporter AcrD Confers Resistance to Egg White in Salmonella enterica Serovar Enteritidis

The excellent survival ability of Salmonella enterica serovar Enteritidis (S. Enteritidis) in egg white leads to outbreaks of salmonellosis frequently associated with eggs and egg products. Our previous proteomic study showed that the expression of multidrug efflux RND transporter AcrD in S. Enteritidis was significantly up-regulated (4.06-fold) in response to an egg white environment. In this study, the potential role of AcrD in the resistance of S. Enteritidis to egg white was explored by gene deletion, survival ability test, morphological observation, Caco-2 cell adhesion and invasion. It was found that deletion of acrD had no apparent effect on the growth of S. Enteritidis in Luria-Bertani (LB) broth but resulted in a significant (p < 0.05) decrease in resistance of S. Enteritidis to egg white and a small number of cell lysis. Compared to the wild type, a 2-log population reduction was noticed in the ΔacrD mutant with different initial concentrations after incubation with egg white for 3 days. Furthermore, no significant difference (p > 0.05) in the adhesion and invasion was found between the wild type and ΔacrD mutant in LB broth and egg white, but the invasion ability of the ΔacrD mutant in egg white was significantly (p < 0.05) lower than that in LB broth. This indicates that acrD is involved in virulence in Salmonella. Taken together, these results reveal the importance of AcrD on the resistance of S. Enteritidis to egg white.

Salmonella enterica serovar Typhimurium chitinases modulate the intestinal glycome and promote small intestinal invasion

Salmonella enterica serovar Typhimurium (Salmonella) is one of the leading causes of food-borne illnesses worldwide. To colonize the gastrointestinal tract, Salmonella produces multiple virulence factors that facilitate cellular invasion. Chitinases have been recently emerging as virulence factors for various pathogenic bacterial species and the Salmonella genome contains two annotated chitinases: STM0018 (chiA) and STM0233. However, the role of these chitinases during Salmonella pathogenesis is unknown. The putative chitinase STM0233 has not been studied previously and only limited data exists on ChiA. Chitinases typically hydrolyze chitin polymers, which are absent in vertebrates. However, chiA expression was detected in infection models and purified ChiA cleaved carbohydrate subunits present on mammalian surface glycoproteins, indicating a role during pathogenesis. Here, we demonstrate that expression of chiA and STM0233 is upregulated in the mouse gut and that both chitinases facilitate epithelial cell adhesion and invasion. Salmonella lacking both chitinases showed a 70% reduction in invasion of small intestinal epithelial cells in vitro. In a gastroenteritis mouse model, chitinase-deficient Salmonella strains were also significantly attenuated in the invasion of small intestinal tissue. This reduced invasion resulted in significantly delayed Salmonella dissemination to the spleen and the liver, but chitinases were not required for systemic survival. The invasion defect of the chitinase-deficient strain was rescued by the presence of wild-type Salmonella, suggesting that chitinases are secreted. By analyzing N-linked glycans of small intestinal cells, we identified specific N-acetylglucosamine-containing glycans as potential extracellular targets of Salmonella chitinases. This analysis also revealed differential abundance of Lewis X-containing glycans that is likely a result of host cell modulation due to the detection of Salmonella chitinases. Similar glycomic changes elicited by chitinase deficient strains indicate functional redundancy of the chitinases. Overall, our results demonstrate that Salmonella chitinases contribute to intestinal adhesion and invasion through modulation of the host glycome.Author SummarySalmonella Typhimurium infection is one of the leading causes of food-borne illnesses worldwide. In order for Salmonella to effectively cause disease, it has to invade the epithelial cells lining the intestinal tract. This invasion step allows Salmonella to replicate efficiently, causing further tissue damage and inflammation. In susceptible patients, Salmonella can spread past the intestines and infect peripheral organs. It is essential to fully understand the invasion mechanism used by Salmonella to design better treatments for infection. Here, we demonstrate that the two chitinases produced by Salmonella are involved in this invasion process. We show that Salmonella chitinases interact with surface glycans of intestinal epithelial cells and promote adhesion and invasion. Using a mouse infection model, we show that Salmonella chitinases are required for the invasion of the small intestine and enhance the dissemination of Salmonella to other organs. This study reveals an additional mechanism by which Salmonella invades and causes infection.

Bidirectional Interaction Between Cancer Cells and Platelets Provides Potential Strategies for Cancer Therapies

Platelets are essential components in the tumor microenvironment. For decades, clinical data have demonstrated that cancer patients have a high risk of thrombosis that is associated with adverse prognosis and decreased survival, indicating the involvement of platelets in cancer progression. Increasing evidence confirms that cancer cells are able to induce production and activation of platelets. Once activated, platelets serve as allies of cancer cells in tumor growth and metastasis. They can protect circulating tumor cells (CTCs) against the immune system and detachment-induced apoptosis while facilitating angiogenesis and tumor cell adhesion and invasion. Therefore, antiplatelet agents and platelet-based therapies should be developed for cancer treatment. Here, we discuss the mechanisms underlying the bidirectional cancer-platelet crosstalk and platelet-based therapeutic approaches.

Phage Therapy Related Microbial Succession Associated with Successful Clinical Outcome for a Recurrent Urinary Tract Infection

We rationally designed a bacteriophage cocktail to treat a 56-year-old male liver transplant patient with complex, recurrent prostate and urinary tract infections caused by an extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) (UCS1). We screened our library for phages that killed UCS1, with four promising candidates chosen for their virulence, mucolytic properties, and ability to reduce bacterial resistance. The patient received 2 weeks of intravenous phage cocktail with concomitant ertapenem for 6 weeks. Weekly serum and urine samples were collected to track the patient’s response. The patient tolerated the phage therapy without any adverse events with symptom resolution. The neutralization of the phage activity occurred with sera collected 1 to 4 weeks after the first phage treatment. This was consistent with immunoassays that detected the upregulation of immune stimulatory analytes. The patient developed asymptomatic recurrent bacteriuria 6 and 11 weeks following the end of phage therapy—a condition that did not require antibiotic treatment. The bacteriuria was caused by a sister strain of E. coli (UCS1.1) that remained susceptible to the original phage cocktail and possessed putative mutations in the proteins involved in adhesion and invasion compared to UCS1. This study highlights the utility of rationally designed phage cocktails with antibiotics at controlling E. coli infection and suggests that microbial succession, without complete eradication, may produce desirable clinical outcomes.

A Cranberry Concentrate Decreases Adhesion and Invasion of Escherichia coli (AIEC) LF82 In Vitro

While many beneficial host–microbiota interactions have been described, imbalanced microbiota in the gut is speculated to contribute to the progression and recurrence of chronic inflammatory diseases such as Crohn’s disease (CD). This in vitro study evaluated the impact of a cranberry concentrate Type M (CTM) on adherent-invasive Escherichia coli (AIEC) LF82, a pathobiont associated with CD. Different stages of pathogenic infection were investigated: (i) colonization of the mucus layer, and (ii) adhesion to and (iii) invasion of the epithelial cells. Following 48 h of fecal batch incubation, 0.5 and 1 mM of CTM significantly altered AIEC LF82 levels in a simulated mucus layer, resulting in a decrease of 50.5% in the untreated blank, down to 43.0% and 11.4%, respectively. At 1 mM of CTM, the significant decrease in the levels of AIEC LF82 coincided with a stimulation of the metabolic activity of the background microbiota. The increased levels of health-associated acetate (+7.9 mM) and propionate levels (+3.5 mM) suggested selective utilization of CTM by host microorganisms. Furthermore, 1 mM of both fermented and unfermented CTM decreased the adhesion and invasion of human-derived epithelial Caco-2 cells by AIEC LF82. Altogether, this exploratory in vitro study demonstrates the prebiotic potential of CTM and supports its antipathogenic effects through direct and/or indirect modulation of the gut microbiome.

A Review on In vitro Cell Culture Model for Bacterial Adhesion and Invasion: From Simple Monoculture to Co-Culture Human Intestinal Epithelium Model

Aim: This paper reviews the different in vitro models of human intestinal epithelium that have been utilized for studying the adhesion and invasion properties. Problem Statement: The cell adhesion and invasion are the key mechanisms of bacterial pathogenicity that determines their possible routes of transmission. Numerous investigations related to the adhesion and invasion ability of bacterial isolates have been reported on monoculture human intestinal cells. However, the use of monoculture cells has several major disadvantages, such as the inability to reproduce the complex structure that defines the intestine and the inability to accurately predict the mechanism of bacterial adhesion and invasion. Approach: Co-culture models of human intestine have been developed as an alternative to improve the monoculture epithelial cell for adhesion and invasion studies, which provide more flexibility and overcome some of the limitations Conclusion: With the use of diverse in vitro approach, it could provide thorough information on different ability of bacterial adhesion and invasion and it could help to clarify the intricacy of host-pathogen interactions that underpin bacterial pathogenesis.

Role of Phosphorylcholine in Streptococcus Pyogenes Adherence to Epithelial Cells

Background: This study aimed to evaluate the influence of Phosphorylcholine (PC) expression on the adherence and invasion of Streptococcus pyogenes (S. pyogenes) to epithelial cells to clarify the potential effectiveness of a vaccine targeting PC. Methods: Eight clinical strains of S. pyogenes were cultured overnight, and PC expression was evaluated by fluorescence-activated cell sorting. Bacterial adherence and invasion were examined using Detroit 562 cells. An anti-PC-specific monoclonal antibody (TEPC-15) was used to inhibit bacterial PC, and a platelet-activating factor receptor (PAF-R) antagonist (ABT-491) was used to inhibit cellular PAF-R. Additionally, amplification of the emm gene was performed using polymerase chain reaction with the standard primers. Results: The level of PC expressed on the S. pyogenes surfaces differed in each strain. Furthermore, PC expression was different even in the same emm type. Adherence assay experiments showed that there was a significant negative correlation between TEPC-15 and ABT-491 inhibitory effects and PC expression in S. pyogenes. Similarly, intracellular invasion assay experiments showed that there was a significant negative correlation between TEPC-15 and ABT-491 inhibitory effects and PC expression in S. pyogenes. Conclusion: The present study suggests that PC is involved in the cell adhesion and invasion of S. pyogenes, regardless of the emm type.