Increased poly(ADP-ribose) polymerase (PARP)-1 expression and activity are associated with inflammation but not goblet cell metaplasia in murine models of allergen-induced airway inflammation.

Inflammation plays a key role in lung injury and in the pathogenesis of asthma. Two murine models of allergic airway inflammation-sensitization and challenge to ovalbumin (OVA) and intratracheal exposure to interleukin-13 (IL13)-were used to evaluate the expression of poly(ADP-ribose) polymerase-1 (PARP-1) in allergic airway inflammation. Inflammation is prominent in OVA-induced allergic asthma, but this inflammation is greatly reduced by a PARP-1 inhibitor and almost eliminated when PARP-1 knockout mice are subjected to the OVA model. The present study temporally evaluated PARP-1 protein expression, localization, and activity, as well as inflammation and goblet cell metaplasia (GCM), in murine lungs following a single OVA challenge or IL13 exposure. Following OVA challenge PARP-1 protein expression and activity were greatly increased, being maximal at 3 to 5 days following OVA exposure and beginning to decrease by day 8. These changes correlated with the timing and degree of inflammation and GCM. In contrast, PARP-1 protein or activity did not change following single IL13 exposure, though GCM was manifested without inflammation. This study demonstrates that both PARP-1 protein and activity are increased by allergen-activated inflammatory mediators, excluding IL13, and that PARP-1 increase does not appear necessary for GCM, one of the characteristic markers of allergic airway inflammation in murine models.

Pembrolizumab Combined With Either Docetaxel or Gemcitabine in Patients With Advanced or Metastatic Platinum-Refractory Urothelial Cancer: Results From a Phase I Study.

INTRODUCTION: Cytotoxic chemotherapy might prime urothelial cancer (UC) to checkpoint inhibition, prompting a trial of chemotherapy with the programmed death receptor-1 inhibitor pembrolizumab. PATIENTS AND METHODS: Patients with advanced, platinum-refractory UC received pembrolizumab and either docetaxel (arm A) or gemcitabine (arm B). Primary end points were assessments of maximum tolerated dose and dose-limiting toxicity (DLT). Secondary end points were overall response rate (ORR) and progression-free survival (PFS). RESULTS: Twelve patients were enrolled in the initial cohorts; 6 in each arm. One DLT was seen in each arm: Grade 3 hypophosphatemia (arm A), Grade 3 diarrhea (arm B). Adverse events of Grade >3 were observed in 7 (54%), the most common being anemia (6; 50%), fatigue (6; 50%), hyponatremia (4; 33%) and neutropenia (3; 25%), with no treatment-related deaths. There were 5 confirmed responses (1 complete, 4 partial), with an ORR of 42% and disease control rate (DCR) of 58%. Arm A had an ORR of 50% and DCR of 67%, whereas arm B had an ORR of 33% and DCR of 50%. Median PFS was 4.8, 5.7, and 3.7 months for the overall cohort, arm A, and arm B, respectively. CONCLUSION: Pembrolizumab with either docetaxel or gemcitabine is feasible for treatment of platinum-refractory advanced UC patients. Preliminary efficacy was observed. Further examination is warranted.

Localization and expression of MUC5B and MUC7 mucins in pediatric sinus mucosa.

OBJECTIVES: The purpose of this study was to analyze the secretory cell population and distribution of MUC5B and MUC7 mucins in the sinus mucosa of pediatric patients with and without chronic rhinosinusitis (CRS). METHODS: Sinus mucosal specimens were collected at surgery in a pediatric tertiary care facility. Histologic, immunohistochemical, and morphometric analyses were performed on sinus mucosa of 20 children with CRS and 7 children without CRS. RESULTS: A significant increase in the area of submucosal glands was evident in the sinus mucosa of children with CRS as compared to controls. MUC5B and MUC7 mucins were expressed in the submucosal glands, as well as in goblet cells, in the sinus mucosa of both populations. No differences in MUC5B or MUC7 expression were observed when mucin expression was normalized to glandular area. CONCLUSIONS: Children with CRS have an increased number of submucosal glands, indicating that glandular mucins contribute to mucus overproduction in CRS. MUC5B and MUC7 mucins, which have previously been considered only glandular mucins, are also expressed in goblet cells in the sinus mucosa.

Immunohistochemical analyses of MUC5AC mucin expression in sinus mucosa of children with sinusitis and controls.

OBJECTIVES: The purpose of this study was to analyze MUC5AC protein expression in sinus mucosal specimens of children with and without chronic sinusitis. METHODS: Morphometric, histologic, and immunohistochemical analyses were carried out on sinus mucosa of 7 children with chronic sinusitis and 6 children without sinusitis. RESULTS: MUC5AC protein was expressed in a subset of goblet cells in the surface epithelium, but not in the submucosal glands in either pediatric population. The number of goblet cells that expressed MUC5AC mucin was not significantly different in patients with and without chronic sinusitis. All specimens had similar numbers of goblet cells in the surface epithelium. CONCLUSIONS: The data demonstrate that neither goblet cell hyperplasia nor increased MUC5AC expression occurs in the sinus mucosa of children with chronic sinusitis. This suggests that in contrast to asthma, in which goblet cell hyperplasia is present in the lower respiratory tract, mucus hypersecretion in pediatric chronic sinusitis may involve other secretory cells, eg, submucosal glandular cells, and mucins secreted by these glandular cells.

Acute airway distress from endotracheal intubation injury in the pediatric aerodigestive tract.

OBJECTIVES: Two unusual cases of pediatric aerodigestive tract trauma postintubation with subsequent complications are described. Pediatric retropharyngeal dissection from trauma has not been reported previously. METHODS: We conducted a retrospective chart review in a pediatric tertiary care center. RESULTS: A 6-year-old girl underwent attempted nasotracheal intubation. She sustained retropharyngeal dissection, receiving positive pressure ventilation before this injury was noted. She developed subcutaneous emphysema. The child was managed conservatively and did well. An 8-year-old boy sustained a 4-cm laceration of his posterior trachea, developing pneumomediastinum after intubation. On transfer to our institution, he underwent direct laryngobronchoscopy and was reintubated with the tip of the endotracheal tube distal to the laceration. Postoperatively, the child accidentally pulled his tube and coughed, resulting in severe subcutaneous emphysema with increased pneumomediastinum. An emergent tracheotomy was performed. The patient subsequently did well. CONCLUSION: A higher index of suspicion with more careful surveillance may prevent further morbidity.

Histologic characteristics and mucin immunohistochemistry of cystic fibrosis sinus mucosa.

OBJECTIVES: To evaluate the histologic characteristics of paranasal sinus mucosa of a disease control population and children with chronic rhinosinusitis and cystic fibrosis (CRS/CF) (1) to determine whether goblet cell (GC) hyperplasia and/or submucosal gland (SMG) hyperplasia occur in pediatric CRS/CF and (2) to compare expression and localization of MUC5AC and MUC5B mucins in the sinus mucosa of both cohorts. DESIGN: Histologic and morphometric analyses of paranasal sinus mucosa were used to quantify the number of GCs and mucin-expressing cells. Digital imaging was used to evaluate the SMG area. Immunohistochemistry was performed to identify the cellular localization of MUC5AC and MUC5B mucins, and confocal microscopy was used to determine whether MUC5AC and MUC5B mucins were expressed in the same secretory cells. SETTING: Children's National Medical Center, Washington, DC. PARTICIPANTS: Twenty-one children with CRS/CF who underwent endoscopic sinus surgical procedures and 18 children who underwent craniofacial resection or neurosurgical procedures for abnormalities other than sinusitis. RESULTS: A statistically significant increased area (4.4-fold) of SMGs was detected in the sinus mucosa of patients with CRS/CF compared with the controls (P = .02). Neither GC hyperplasia nor increased expression of MUC5AC was observed in the CRS/CF group. MUC5AC was expressed only in a subpopulation of GCs in both cohorts, and MUC5B was expressed in a subpopulation of GCs as well as in SMGs. There was a positive trend toward increased glandular MUC5B expression in the CRS/CF cohort. Colocalization of MUC5AC and MUC5B expression was observed in a subset of GCs. CONCLUSIONS: Significant SMG hyperplasia and a trend toward increased glandular MUC5B expression exist in children with CRS/CF. This suggests that SMG hyperplasia and glandular MUC5B mucin contribute to mucus overproduction in the sinus mucosa of this population.

Expression profiling of inflammatory mediators in pediatric sinus mucosa.

OBJECTIVE: To evaluate gene expression by microarray analyses of inflammatory mediators in the sinus mucosa of children with and without chronic rhinosinusitis (CRS). DESIGN: Prospective molecular genetics analysis. SETTING: Children's National Medical Center, Washington, DC. SUBJECTS: Eleven patients with CRS who underwent endoscopic sinus surgery and 10 control children who underwent craniofacial resection or neurosurgical procedures. MAIN OUTCOME MEASURES: Gene expression levels of sinus tissue from 6 patients with CRS and 6 controls and messenger RNA expression levels of upregulated inflammatory/immune response genes, as well as cytokines of interest, determined by quantitative reverse transcription-polymerase chain reaction. RESULTS: Gene expression using the Plier algorithm yielded the most consistent grouping of samples: 96 genes were significantly upregulated more than 2-fold, and 123 genes were downregulated by at least 50% in the CRS sinus tissues compared with controls (P < .05). GeneSpring analysis demonstrated significant changes in several ontology categories in the CRS samples, including inflammatory/immune response genes. The chemokines CXCL13 and CXCL5, serum amyloid A, serpin B4, and defensin beta1 were highly upregulated (> or =5-fold). Increased expression of these genes was validated by quantitative reverse transcription-polymerase chain reaction in an independent set of tissues. Expression levels of interleukins 5, 6, and 8 were similar in both cohorts; these results were validated by reverse transcription-polymerase chain reaction. CONCLUSIONS: Microarray analyses of sinus mucosa in children with CRS showed an increased expression of inflammatory genes involved in innate and adaptive immune systems. This technology can be successfully used to identify genes implicated in the pathogenesis of pediatric CRS.

Temporal analysis of goblet cells and mucin gene expression in murine models of allergic asthma.

In murine models of allergic asthma, mice repeatedly exposed to allergens or interleukin (IL)13 have numerous goblet cells in their airway epithelium, in contrast to healthy naïve mice. This study evaluated whether a single airway exposure of ovalbumin or IL13 would produce goblet cell metaplasia. Following ovalbumin challenge, airway goblet cells were present by 1 day, increased further by day 2 and day 3, and decreased by day 8. Following IL13 exposure, some goblet cells were detected at 6 hours and increased by 18 and 48 hours. Goblet transition cells, which are morphologically but not histologically similar to goblet cells, were observed at 6 and 18 hours following IL13 exposure and day 1 following ovalbumin challenge. Increased Muc5ac and Muc2 mRNA expression occurred following ovalbumin or IL13, but not saline, exposure. Mucin transcripts were localized to goblet cells in the surface airway epithelium. Muc5ac protein was expressed in some goblet transition and goblet cells. Overall, these data demonstrated that a single airway exposure to ovalbumin or IL13 is sufficient to generate goblet cell metaplasia and thus increase mucin gene expression in two strains of mice.