Comparative functional analysis of aquaporins/glyceroporins in mammals and anurans

Maintenance of fluid homeostasis is critical to establishing and maintaining normal physiology. The landmark discovery of membrane water channels (aquaporins; AQPs) ushered in a new area in osmoregulatory biology that has drawn from and contributed to diverse branches of biology, from molecular biology and genomics to systems biology and evolution, and from microbial and plant biology to animal and translational physiology. As a result, the study of AQPs provides a unique and integrated backdrop for exploring the relationships between genes and genome systems, the regulation of gene expression, and the physiologic consequences of genetic variation. The wide species distribution of AQP family members and the evolutionary conservation of the family indicate that the control of membrane water flux is a critical biological process. AQP function and regulation is proving to be central to many of the pathways involved in individual physiologic systems in both mammals and anurans. In mammals, AQPs are essential to normal secretory and absorptive functions of the eye, lung, salivary gland, sweat glands, gastrointestinal tract, and kidney. In urinary, respiratory, and gastrointestinal systems, AQPs are required for proper urine concentration, fluid reabsorption, and glandular secretions. In anurans, AQPs are important in mediating physiologic responses to changes in the external environment, including those that occur during metamorphosis and adaptation from an aquatic to terrestrial environment and thermal acclimation in anticipation of freezing. Therefore, an understanding of AQP function and regulation is an important aspect of an integrated approach to basic biological research

New insights into disease pathogenesis in crusted (Norwegian) scabies: the skin immune response in crusted scabies

United Kingdo

Nasal polyp cell populations and fungal-specific peripheral blood lymphocyte proliferation in allergic fungal sinusitis

Background: Allergic fungal sinusitis (AFS) is considered a different disease from other polypoid chronic rhinosinusitis diseases (CRS) with eosinophilic mucus (EM) termed eosinophilic mucus chronic rhinosinusitis (EMCRS). To substantiate this, studies on cellular responses to fungi and sinus mucosal inflammatory cell populations in AFS and other EMCRS diseases are required. This study was designed to examine polyp inflammatory cell populations and peripheral blood fungal-specific T-cell responses in AFS, other EMCRS subgroups (defined later), and polypoid CRS without EM. Methods: A prospective study was performed. Clinical characteristics, including CRS symptoms, sinus computed tomography (CT) scans, allergy status, intraoperative endoscopy, presence of EM, and fungal culture results were used to define patient groups. Polyps and peripheral blood were examined for populations of eosinophils, lymphocytes (CD4+, CD8+ T cells, natural killer cells, and B cells), and neutrophils using immunohistochemistry, cytospin preparations and flow cytometry. Fungal-specific peripheral blood lymphocyte proliferation was examined in AFS patients, other EMCRS patients, CRS patients, and controls. Results: There was no significant difference in the percentage of cell populations and fungal-specific lymphocyte proliferation between AFS and other EMCRS diseases. However, AFS and other EMCRS polyps had a higher percentage of eosinophils and CD8+ T cells whereas CRS polyps had higher CD4+ T cells. Fungal-specific lymphocyte proliferation was significantly greater in AFS and other EMCRS patients regardless of fungal allergy, whereas in CRS and controls, higher proliferation was observed in fungal-allergic individuals. Conclusion: These findings question the basis for differentiating AFS from other EMCRS diseases based on fungal allergy and fungi in EM. Fungal-specific cellular response was present in AFS and other EMCRS diseases, different from that associated with fungal allergy, suggesting a nonallergic fungal immune response. Increased CD8+ T cells in EMCRS polyps signify a different type of inflammation to CRS that may be driven by CD8+ T cells.Harshita Pant, Dimitra Beroukas, Frank E. Kette, William B. Smith, Peter J. Wormald, Peter J. Macardl

Histopathological and ultrastructural features of dermal telangiectasias in systemic sclerosis

Aims: To investigate the histological, ultrastructural and immunohistochemical features of the vascular lining of dermal telangiectasia, a characteristic clinical finding in scleroderma. Methods: Standard histological, electron microscopic and immunohistological techniques were used to examine dermal telangiectasias in five patients with limited scleroderma, the most common scleroderma variant in Caucasian populations. Results: The telangiectasias were dilated postcapillary venules located in the papillary and superficial reticular dermis. The vessel walls consisted of non‐fenestrated endothelial cells surrounded by a variable number of pericytes and smooth muscle cells. There were no unique ultrastructural features. Thickened collagen fibres in the reticular or deep dermis were seen in all but one patient, although in variable and generally minimal quantities. Surrounding infiltrating inflammatory cells were scarce. No enhanced endothelial staining was obtained with antibodies directed against endoglin, endothelin, E‐selectin and ICAM‐1 suggesting a resting or inactivated state. Conclusion: The immunohistological and ultrastructural features of the lining endothelium of established telangiectasias in long‐standing, limited scleroderma appear benign. It would be of interest to examine telangiectasias in the early phase of their formation. Alternatively, other explanations need to be explored in understanding the aetiopathogenesis of telangiectasia in scleroderma.Jennifer G. Walker, John Stirling, Dimitra Beroukas, Kencana Dharmapatni, David R. Haynes, Malcolm D. Smith, Michael J. Ahern and Peter J. Roberts-Thomso

Expression of Jak3, STAT1, STAT4, and STAT6 in inflammatory arthritis: unique Jak3 and STAT4 expression in dendritic cells in seropositive rheumatoid arthritis

BACKGROUND: Modulation of Jak‐STAT signalling may provide an effective therapeutic strategy in inflammatory arthritis. OBJECTIVE: To document Jak‐STAT expression in a cohort of patients with active rheumatoid arthritis (RA), spondyloarthritis (SpA), and osteoarthritis (OA) and compare these subsets with normal synovial tissue. METHODS: Synovial tissue biopsy specimens from patients with RA, OA, and SpA and histologically normal tissue (n = 10 in each arthritis group) were examined for the presence of Jak3, STAT1, STAT4, and STAT6 expression using immunohistochemistry. Phenotyping was performed using immunohistochemistry and immunofluorescence. Clinical and serological characteristics of patients with RA expressing Jak3‐STAT4 were assessed. RESULTS: STAT1, STAT4, and Jak3 protein expression was generally increased in inflammatory arthritis. In contrast, STAT6 expression was relatively heterogeneous. A subpopulation of CD1a positive dendritic cells unique to seropositive patients with RA was detected. These cells showed intense protein expression for Jak3, STAT4, and STAT6. CONCLUSION: CD1a positive dendritic cells intensely express Jak3, STAT4, and STAT6 in seropositive RA tissue and may be an alternative marker for dendritic cells in their early stages of activation as well as providing a tool for identifying RA at the level of the synovium. Jak3 inhibition may be a potential therapeutic target to prevent dendritic cell maturation in RA. STAT1 expression is increased in inflammatory arthritis, suggesting that its pro‐apoptotic and anti‐inflammatory effects cannot effectively counteract inflammation. STAT6 expression is heterogeneous in synovium, suggesting a possible homoeostatic role in addition to any anti‐inflammatory effects

Changes in synovial tissue Jak‐STAT expression in rheumatoid arthritis in response to successful DMARD treatment

BACKGROUND: Modulation of Jak‐STAT signalling may provide an effective therapeutic strategy in inflammatory arthritis (IA). OBJECTIVE: To examine the effect of successful disease‐modifying antirheumatic drug (DMARD) treatment on the expression of Jak‐STAT in a cohort of patients with active rheumatoid arthritis. METHODS: Synovial tissue biopsy specimens from 16 patients with active rheumatoid arthritis, taken before and after initiation of DMARD treatment, were examined for the presence of janus kinase (Jak)3, signal transducer and activator of transcription (STAT)1, STAT4 and STAT6 expression using immunohistochemistry. RESULTS: Successful treatment with DMARDs results in reduction in STAT1 expression in the lining, and STAT1 and STAT6 in the sublining of rheumatoid arthritis synovial tissue. Although the overall expression of STAT4 and Jak3 was not significantly altered by DMARD treatment, there was a significant reduction in the expression of the STAT4 and Jak3 bright cells, thought to be an activated dendritic cell subpopulation. CONCLUSION: Results show that Jak3, STAT1, STAT4 expression and STAT6 sublining expression decrease in response to successful treatment of rheumatoid arthritis with standard DMARDs. Therefore, altering the expression of these pathways may represent an alternative treatment option, either through promoting up‐regulation of inhibitory pathways, or suppressing inflammatory paths