We describe the tripeptide neutrophil chemoattractant N-acetyl Pro-Gly-Pro (PGP), derived from the breakdown of extracellular matrix (ECM), which shares sequence and structural homology with an important domain on alpha chemokines. PGP caused chemotaxis and production of superoxide through CXC receptors, and administration of peptide caused recruitment of neutrophils (PMNs) into lungs of control, but not CXCR2-deficient mice. PGP was generated in mouse lung after exposure to lipopolysaccharide, and in vivo and in vitro blockade of PGP with monoclonal antibody suppressed PMN responses as much as chemokine-specific monoclonal antibody. Extended PGP treatment caused alveolar enlargement and right ventricular hypertrophy in mice. PGP was detectable in substantial concentrations in a majority of bronchoalveolar lavage samples from individuals with chronic obstructive pulmonary disease, but not control individuals. Thus, PGP's activity links degradation of ECM with neutrophil recruitment in airway inflammation, and PGP may be a biomarker and therapeutic target for neutrophilic inflammatory diseases.
Prolyl endopeptidase (PE), a protease that cleaves after proline residues in oligopeptides, is highly active in brain and degrades neuropeptides in vitro. We have recently demonstrated that PE, in concert with MMP's, can generate PGP (prolineglycine-proline), a novel, neutrophil chemoattractant, from collagen. In this study, we demonstrate that human peripheral blood neutrophils contain PE, which is constitutively active, and can generate PGP de novo from collagen after activation with LPS. This novel, pro-inflammatory role for PE raises the possibility of a self-sustaining pathway of neutrophilic inflammation and may provide biomarkers and therapeutic targets for diseases caused by chronic, neutrophilic inflammation.
Lung transplantation is a therapeutic modality frequently utilized in end-stage lung disease. Unfortunately, lung transplant recipients have poor clinical outcomes, often due to the development of chronic rejection in the transplanted allograft. This process is characterized by neutrophil influx and extracellular matrix remodeling leading to luminal obstruction and airway inflammation. The molecular mechanisms underlying chronic rejection are poorly understood and disease-specific biomarkers are lacking. We report that in addition to increased levels of interleukin-8 (IL-8), the level of neutrophil chemoattractant proline-glycine-proline (PGP) is elevated in chronic rejection patient bronchoalveolar lavage (BAL) fluid and correlates with loss of lung function. The enzymes responsible for generating PGP, matrix metalloproteases-8 and -9 (MMP-8, -9) and prolyl endopeptidase (PE), are also elevated in chronic rejection samples. Together, IL-8 and PGP account for most of the neutrophil chemoattractant capacity seen in chronic rejection BAL fluid. Using specific neutralizing antibodies to both IL-8 and PGP, we demonstrate that PGP is the major neutrophil chemoattractant found in BAL fluid from individuals at the time of chronic rejection. These findings highlight the influence of a matrix-derived neutrophil chemoattractant in post-transplantation organ rejection and provide opportunities for the development of unique diagnostics and therapeutics to potentially improve disease outcomes.
Competency-based education (CBE) provides a framework for nursing programs including those educating nurse practitioners (NPs). The basic assumption of CBE is that the student will demonstrate acquisition of the identified essential knowledge, skills, and attitudes expected for the designated educational process before leaving the learning environment. The work done to date in developing competencies and progression indicators provides the critical basis to move toward a common language and clear expectations for the continuum of linear progression of proficiency. Entrustable professional activities (EPAs) are built on competencies and stated as measurable activities that providers can be expected to do, at varying levels of competence or trust or supervision, and allow the faculty member, preceptor, or supervisor to make decisions as to what teaching methods and level of supervision are needed. Numerous methods are used to measure competency in clinical skill knowledge, performance, and practice readiness including clinical preceptor feedback, objective structured clinical examination, and simulation, just to name a few. NP programs continue to struggle with the education practice gap between theory and the actual provision of care. The discussion about novel and reliable methods for measurement of competencies must address the strategic importance of a consensus about when, where, and how students can obtain the appropriate amount and type of experience and supervision required in the transition to independent practice. There is also a significant need for processes and standardized guidelines that can contribute to EPA development.
To determine the degree ofsimilarity between pituitary and lymphocyte proopliomelanocortin, the lymphocyte mRNA was reverse transcribed, cloned, and sequenced. Murine lymphocyte mRNA was first purified by oligo(dT)-cellulose affinity chromatography and was reverse transcribed by using a selective 3' antisense oligonucleotide primer directed at the boundary between the translated/nontranslated region on the 3' end of exon 3.
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