Osteopontin binds and modulates functions of eosinophil-recruiting chemokines.

BACKGROUND: Allergic asthma is characterized by eosinophilic inflammation and airway obstruction. There is also an increased risk of pulmonary infection caused by Streptococcus pneumoniae, in particular during severe asthma where high levels of the glycoprotein, osteopontin (OPN), are present in the airways. Eosinophils can be recruited by chemokines activating the receptor CCR3 including eotaxin-1/CCL11, eotaxin-2/CCL24, eotaxin-3/CCL26, RANTES/CCL5, and MEC/CCL28. In addition to inducing chemotaxis, several of these molecules have defensin-like antibacterial properties. This study set out to elucidate the functional consequences of OPN binding to eosinophil-recruiting chemokines. METHODS: Antibacterial activities of the chemokines were investigated using viable count assays and electron microscopy. Binding studies were performed by means of surface plasmon resonance. The potential interference of OPN with antibacterial, receptor-activating, and lipopolysaccharide-neutralizing abilities of these chemokines was investigated. RESULTS: We found that OPN bound all eosinophil-recruiting chemokines with high affinity except for CCL5. The eosinophil-recruiting chemokines all displayed bactericidal activity against S. pneumoniae, but only CCL26 and CCL28 retained high antibacterial activity in the presence of sodium chloride at physiologic concentrations. Preincubation of the chemokines with OPN strongly inhibited their antibacterial activity against S. pneumoniae but did not affect their ability to activate CCR3. All chemokines investigated showed LPS-neutralizing activity that was impaired by OPN only in the case of CCL24. CONCLUSIONS: The data suggest that OPN may impair host defense activities of the chemokines without affecting their eosinophil-recruiting properties. This could be one mechanism explaining the increased vulnerability to acquire pneumococcal infection in parallel with sustained allergic inflammation in asthma.

Eotaxin-3 (CCL26) exerts innate host defense activities that are modulated by mast cell proteases.

BACKGROUND: During bacterial infections of the airways, a Th1-profiled inflammation promotes the production of several host defense proteins and peptides with antibacterial activities including ß-defensins, ELR-negative CXC chemokines, and the cathelicidin LL-37. These are downregulated by Th2 cytokines of the allergic response. Instead, the eosinophil-recruiting chemokines eotaxin-1/CCL11, eotaxin-2/CCL24, and eotaxin-3/CCL26 are expressed. This study set out to investigate whether these chemokines could serve as innate host defense molecules during allergic inflammation. METHODS: Antibacterial activities of the eotaxins were investigated using viable count assays, electron microscopy, and methods assessing bacterial permeabilization. Fragments generated by mast cell proteases were characterized, and their potential antibacterial, receptor-activating, and lipopolysaccharide-neutralizing activities were investigated. RESULTS: CCL11, CCL24, and CCL26 all showed potent bactericidal activity, mediated through membrane disruption, against the airway pathogens Streptococcus pneumoniae, Staphylococcus aureus, Nontypeable Haemophilus influenzae, and Pseudomonas aeruginosa. CCL26 retained bactericidal activity in the presence of salt at physiologic concentrations, and the region holding the highest bactericidal activity was the cationic and amphipathic COOH-terminus. Proteolysis of CCL26 by chymase and tryptase, respectively, released distinct fragments of the COOH- and NH2 -terminal regions. The COOH-terminal fragment retained antibacterial activity while the NH2 -terminal had potent LPS-neutralizing properties in the order of CCL26 full-length protein. An identical fragment to NH2 -terminal fragment generated by tryptase was obtained after incubation with supernatants from activated mast cells. None of the fragments activated the CCR3-receptor. CONCLUSIONS: Taken together, the findings show that the eotaxins can contribute to host defense against common airway pathogens and that their activities are modulated by mast cell proteases.

Midkine in host defence.

UNLABELLED: Midkine (MK) shares several features in common with antibacterial proteins of the innate immune system. These include growth factor properties, heparin-binding regions and effects on immune cells, such as recruitment and activation of neutrophils and macrophages. Indeed, recent research has demonstrated potent bactericidal and fungicidal activities of MK. This protein is constitutively expressed at relevant concentrations at barriers of the body, such as the skin and the large airways, where the body first encounters potential pathogens. The antibacterial properties of MK orthologues are preserved during evolution, as exemplified by miple2 of Drosophila. In addition to retinoic acid, promoters of MK gene expression include factors present at sites of infection, reactive oxygen species, activation of the transcription factor NF-κB and hypoxia. In the light of the development of resistance in pathogenic bacteria to conventional antibiotics, MK is an interesting molecule that could serve as a template in developing novel therapeutic strategies against bacterial and fungal infections, either alone or in combination with conventional antibiotics. LINKED ARTICLES: This article is part of a themed section on Midkine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-4.

Circular vs. three-quadrant hemorrhoidectomy for end-stage hemorrhoids: short- and long-term outcomes of a prospective randomized trial.

PURPOSE: Circumferential excisional hemorrhoidectomy (CEH) enables the surgeon to remove the encircling hemorrhoids completely. The purpose of this study is to compare the efficacy of CEH with that of Ferguson hemorrhoidectomy (FH) for end-stage hemorrhoids. METHODS: Between February 1998 and December 2011, a prospective randomized trial was conducted with 688 patients who presented with end-stage hemorrhoids and underwent FH or CEH at our center. RESULTS: The patient demographics, mean operative times, lengths of hospital stay, and cumulative rates of postoperative complications were similar in the study groups. Significant differences were revealed in the incidence of postoperative hemorrhage (9 vs. 0 patients in the FH and CEH groups, respectively; p = 0.002) and in the tendency to form anal stricture (15 vs. 32 patients in the FH and CEH groups, respectively; p = 0.02). However, all cases of anal strictures were easily managed by digital dilatations. At a mean follow-up of 7.4 (range, 1-14) years, accessible patients from the CEH group remained symptom free, whereas 126 of 308 patients in the FH group indicated that they had recurrent hemorrhoidal symptoms. CONCLUSION: Without increasing postoperative complications, CEH demonstrates an advantage compared with FH, with regard to reducing the rate of recurrence to 0 through complete hemorrhoid removal.

Circumferential excisional hemorrhoidectomy for extensive acute thrombosis: a 14-year experience.

BACKGROUND: Recurrence and/or complications after 3-quadrant hemorrhoidectomy or stapled hemorrhoidopexy still remain a challenging problem. This challenge is even greater for massive hemorrhoidal thrombosis leading to edema, ulceration, and/or gangrene. To address this challenge, we developed a further modification of the Whitehead procedure termed circumferential excisional hemorrhoidectomy. The proposed procedure allows access to a submucoanodermal/skin workspace that provides a "view from inside" the hemorrhoidal disease, and therefore facilitates the precise excision of even each hemorrhoidal vein while preserving the overlying normal tissues. OBJECTIVE: This study aimed to describe the circumferential excisional hemorrhoidectomy procedure and to demonstrate its results in patients presenting with total hemorrhoidal thrombosis. DESIGN, SETTINGS, PATIENTS: This prospective, descriptive study was conducted with 294 consecutive patients who underwent urgent circumferential excisional hemorrhoidectomy at our coloproctological center from January 1996 to June 2009. INTERVENTION: Circumferential excisional hemorrhoidectomy involves the stripping and excision of hemorrhoids from the submucoanodermal space with reconstruction of the anal canal by the use of an undermined irregular/zigzag-shaped mucoanodermal flap and accurately trimmed skin. MAIN OUTCOME MEASURES: The main outcome measures were the surgical outcomes and complications. RESULTS: The mean patient age was 41.7 for both sexes. There were 215 men and 79 women. The mean operative time was 26.4 (range, 17-43) minutes. In terms of postoperative complications, there were 39 (13.2%) urinary retentions, 1 (0.3%) fecal impaction, and 3 (1%) delayed complete wound epithelization. The mean hospital stay was 3.1 (range, 2-5) days, and the mean time off from work was 10 (range, 7-18) days. At the fifth week after surgery, digital rectal examination revealed easily dilated mild stricture in 26 (8.8%) patients. At a mean follow-up of 6.8 (range, 2-14) years, 271 (92.2%) accessible patients were actually symptom-free. LIMITATION: This study did not have a control group. CONCLUSION: Circumferential excisional hemorrhoidectomy is an anatomically safe surgical procedure with a low rate of complications and no recurrences, even after a long-term follow-up.