In models of acute lung injury, CXC chemokine receptor 2 (CXCR2) mediates migration of polymorphonuclear leukocytes (PMNs) into the lung. Since CXCR2 ligands, including CXCL1 and CXCL2/3, are chemotactic for PMNs, CXCR2 is thought to recruit PMNs by inducing chemotactic migration. In a model of PMN recruitment to the lung, aerosolized bacterial LPS inhalation induced PMN recruitment to the lung in wild-type mice, but not in littermate CXCR2–/– mice. Surprisingly, lethally irradiated wild-type mice reconstituted with CXCR2–/– BM still showed about 50% PMN recruitment into bronchoalveolar lavage fluid and into lung interstitium, but CXCR2–/– mice reconstituted with CXCR2–/– BM showed no PMN recruitment. Conversely, CXCR2–/– mice reconstituted with wild-type BM showed a surprisingly large defect in PMN recruitment, inconsistent with a role of CXCR2 on PMNs alone. Cell culture, immunohistochemistry, flow cytometry, and real-time RT-PCR were used to show expression of CXCR2 on pulmonary endothelial and bronchial epithelial cells. The LPS-induced increase in lung microvascular permeability as measured by Evans blue extravasation required CXCR2 on nonhematopoietic cells. Our data revealed what we believe to be a previously unrecognized role of endothelial and epithelial CXCR2 in LPS-induced PMN recruitment and lung injury.
1 February 2013 in American Journal of Surgical Pathology
High-risk human papillomavirus (HPV) is an established cause of head and neck carcinomas arising in the oropharynx. The presence of HPV has also been reported in some carcinomas arising in the sinonasal tract, but little is known about their overall incidence or their clinicopathologic profile. The surgical pathology archives of The Johns Hopkins Hospital were searched for all carcinomas arising in the sinonasal tract from 1995 to 2011, and tissue microarrays were constructed. p16 immunohistochemical analysis and DNA in situ hybridization for high-risk types of HPV were performed. Demographic and clinical outcome data were extracted from patient medical records. Of 161 sinonasal carcinomas, 34 (21%) were positive for high-risk HPV DNA, including type 16 (82%), type 31/33 (12%), and type 18 (6%). HPV-positive carcinomas consisted of 28 squamous cell carcinomas and variants (15 nonkeratinizing or partially keratinizing, 4 papillary, 5 adenosquamous, 4 basaloid), 1 small cell carcinoma, 1 sinonasal undifferentiated carcinoma, and 4 carcinomas that were difficult to classify but exhibited adenoid cystic carcinoma-like features. Immunohistochemistry for p16 was positive in 59/161 (37%) cases, and p16 expression strongly correlated with the presence of HPV DNA: 33 of 34 (97%) HPV-positive tumors exhibited high p16 expression, whereas only 26 of 127 (20%) HPV-negative tumors were p16 positive (P<0.0001). The HPV-related carcinomas occurred in 19 men and 15 women ranging in age from 33 to 87 years (mean, 54 y). A trend toward improved survival was observed in the HPV-positive group (hazard ratio=0.58, 95% confidence interval [0.26, 1.28]). The presence of high-risk HPV in 21% of sinonasal carcinomas confirms HPV as an important oncologic agent of carcinomas arising in the sinonasal tract. Although nonkeratinizing squamous cell carcinoma is the most common histologic type, there is a wide morphologic spectrum of HPV-related disease that includes a variant that resembles adenoid cystic carcinoma. The distinctiveness of these HPV-related carcinomas of the sinonasal tract with respect to risk factors, clinical behavior, and response to therapy remains to be clarified.
Background— Mice lacking leukocyte type 12/15-lipoxygenase (12/15-LO) show reduced atherosclerosis in several models. 12/15-LO is expressed in a variety of cells, including vascular cells, adipocytes, macrophages, and cardiomyocytes. The purpose of this study was to determine which cellular source of 12/15-LO is important for atherosclerosis. Methods and Results— Bone marrow from 12/15-LO −/− /apoE −/− mice was transplanted into apoE −/− mice and vice versa. Deficiency of 12/15-LO in bone marrow cells protected apoE −/− mice fed a Western diet from atherosclerosis to the same extent as complete absence of 12/15-LO, although plasma 8,12- iso -iPF 2α -IV, a measure of lipid peroxidation, remained elevated. 12/15-LO −/− /apoE −/− mice regained the severity of atherosclerotic lesion typical of apoE −/− mice after replacement of their bone marrow cells with bone marrow from apoE −/− mice. Peritoneal macrophages obtained from wild-type but not 12/15-LO −/− mice caused endothelial activation in the presence of native LDL. Absence of 12/15-LO decreased the ability of macrophages to form foam cells when exposed to LDL. Conclusions— We conclude that macrophage 12/15-LO plays a dominant role in the development of atherosclerosis by promoting endothelial inflammation and foam cell formation.