Sounding the alarmins-The role of alarmin cytokines in asthma.

The alarmin cytokines thymic stromal lymphopoietin (TSLP), interleukin (IL)-33, and IL-25 are epithelial cell-derived mediators that contribute to the pathobiology and pathophysiology of asthma. Released from airway epithelial cells exposed to environmental triggers, the alarmins drive airway inflammation through the release of predominantly T2 cytokines from multiple effector cells. The upstream positioning of the alarmins is an attractive pharmacological target to block multiple T2 pathways important in asthma. Blocking the function of TSLP inhibits allergen-induced responses including bronchoconstriction, airway hyperresponsiveness, and inflammation, and subsequent clinical trials of an anti-TSLP monoclonal antibody, tezepelumab, in asthma patients demonstrated improvements in lung function, airway responsiveness, inflammation, and importantly, a reduction in the rate of exacerbations. Notably, these improvements were observed in patients with T2-high and with T2-low asthma. Clinical trials blocking IL-33 and its receptor ST2 have also shown improvements in lung function and exacerbation rates; however, the impact of blocking the IL-33/ST2 axis in T2-high versus T2-low asthma is unclear. To date, there is no evidence that IL-25 blockade is beneficial in asthma. Despite the considerable overlap in the cellular functions of IL-25, IL-33, and TSLP, they appear to have distinct roles in the immunopathology of asthma.

Mechanistic analysis of the role of BLCA-4 in bladder cancer pathobiology.

Analysis of alterations in nuclear structure associated with bladder cancer has revealed specific changes associated with the disease. This includes the identification of six bladder cancer-specific proteins and the successful development of urine-based immunoassays for the detection of two of these biomarkers, BLCA-1 and BLCA-4. The purpose of this study is to examine the functional aspects of BLCA-4 and its potential role in bladder cancer pathobiology. Sequence analysis of BLCA-4 reveals that it is a member of the ETS transcription factor family and that it seems to associate with transcription factors. To examine the effects of this protein, the gene encoding BLCA-4 was stably transfected into human urothelial cells. BLCA-4 expression was confirmed by both PCR and Western blot analysis. BLCA-4 overexpressing clones exhibit a 4.3-fold greater proliferation rate than vector only controls or untransfected cells. Microarray analysis comparing gene expression patterns between overexpressing clones and vector only controls revealed that numerous genes were up-regulated in cells that overexpress BLCA-4. Up-regulated genes included interleukin-1alpha (IL-1alpha), IL-8, and thrombomodulin, and the protein expression of these genes was confirmed by immunoblots. This information has provided a potential model of BLCA-4 action. Overexpression of BLCA-4 seems to increase the growth rate in cells and also causes cells to express a more tumorigenic phenotype.

Antibacterial activity within degradation products of biological scaffolds composed of extracellular matrix.

Biological scaffolds composed of extracellular matrix (ECM) have been shown to be resistant to deliberate bacterial contamination in preclinical in vivo studies. The present study evaluated the degradation products resulting from the acid digestion of ECM scaffolds for antibacterial effects against clinical strains of Staphylococcus aureus and Escherichia coli. The ECM scaffolds were derived from porcine urinary bladder (UBM-ECM) and liver (L-ECM). These biological scaffolds were digested with acid at high temperatures, fractionated using ammonium sulfate precipitation, and tested for antibacterial activity in a standardized in vitro assay. Degradation products from both UBM-ECM and L-ECM demonstrated antibacterial activity against both S. aureus and E. coli. Specific ammonium sulfate fractions that showed antimicrobial activity varied for the 2 different ECM scaffold types. The results of this study suggest that several different low-molecular-weight peptides with antibacterial activity exist within ECM and that these peptides may help explain the resistance to bacterial infection provided by such biological scaffolds.

Degradation products of extracellular matrix affect cell migration and proliferation.

Biologic scaffolds composed of extracellular matrix (ECM) are utilized in numerous regenerative medicine applications to facilitate the constructive remodeling of tissues and organs. The mechanisms by which the host remodeling response occurs are not fully understood, but recent studies suggest that both constituent growth factors and biologically active degradation products derived from ECM play important roles. The objective of the present study was to determine if degradation of ECM scaffold materials in vitro by methods that are biochemically and physiologically relevant can yield products that possess chemotactic and/or mitogenic activities for fully differentiated mammalian endothelial cells and undifferentiated multipotential progenitor cells. ECM harvested from porcine urinary bladder was degraded enzymatically with pepsin/hydrochloric acid or papain. The ECM degradation products were tested for chemoattractant properties utilizing either 48-well chemotaxis filter migration microchambers or fluorescence-based filter migration assays, and were tested for mitogenic properties in cell proliferation assays. Results showed that ECM degradation products possessed chemotactic and mitogenic activities for multipotential progenitor cells and that the same degradation products inhibited both chemotaxis and proliferation of differentiated endothelial cells. These findings support the concept that degradation products of ECM bioscaffolds are important modulators of the recruitment and proliferation of appropriate cell types during the process of ECM scaffold remodeling.

Use of the novel marker BLCA-1 for the detection of bladder cancer.

PURPOSE: Bladder cancer specific nuclear structural alterations have been identified. We examined the expression pattern of one of these proteins, BLCA-1, in tissue and urine samples from individuals with bladder cancer as well as in samples from normal controls. MATERIALS AND METHODS: BLCA-1 sequence data were used to produce antibodies to this protein, which were used in immunoblot and enzyme-linked immunosorbent assays. RESULTS: BLCA-1 was detectable in tissue from patients with bladder cancer but not in normal adjacent areas of the bladder or in normal donor bladder tissue. This protein was also detectable in the urine of patients with bladder cancer by immunoblot and immunoassay. Using a cutoff of 0.025 optical density units (absorbance value) BLCA-1 was detected in 20 of 25 urine samples from patients with bladder cancer but in only 6 of 46 normal, high risk, prostate or renal cancer samples tested, resulting in a test with 80% sensitivity and 87% specificity. Expression of this protein did not appear to correlate with tumor grade. CONCLUSIONS: This research indicates that BLCA-1 is a urine based marker of bladder cancer which may be useful for the detection of this disease.