Lung tissue expression of epithelial injury markers is associated with acute lung injury severity but does not discriminate sepsis from ARDS.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is a common cause of respiratory failure in critically ill patients, and diffuse alveolar damage (DAD) is considered its histological hallmark. Sepsis is one of the most common aetiology of ARDS with the highest case-fatality rate. Identifying ARDS patients and differentiate them from other causes of acute respiratory failure remains a challenge. To address this, many studies have focused on identifying biomarkers that can help assess lung epithelial injury. However, there is scarce information available regarding the tissue expression of these markers. Evaluating the expression of elafin, RAGE, and SP-D in lung tissue offers a potential bridge between serological markers and the underlying histopathological changes. Therefore, we hypothesize that the expression of epithelial injury markers varies between sepsis and ARDS as well as according to its severity. METHODS: We compared the post-mortem lung tissue expression of the epithelial injury markers RAGE, SP-D, and elafin of patients that died of sepsis, ARDS, and controls that died from non-pulmonary causes. Lung tissue was collected during routine autopsy and protein expression was assessed by immunohistochemistry. We also assessed the lung injury by a semi-quantitative analysis. RESULTS: We observed that all features of DAD were milder in septic group compared to ARDS group. Elafin tissue expression was increased and SP-D was decreased in the sepsis and ARDS groups. Severe ARDS expressed higher levels of elafin and RAGE, and they were negatively correlated with PaO2/FiO2 ratio, and positively correlated with bronchopneumonia percentage and hyaline membrane score. RAGE tissue expression was negatively correlated with mechanical ventilation duration in both ARDS and septic groups. In septic patients, elafin was positively correlated with ICU admission length, SP-D was positively correlated with serum lactate and RAGE was correlated with C-reactive protein. CONCLUSIONS: Lung tissue expression of elafin and RAGE, but not SP-D, is associated with ARDS severity, but does not discriminate sepsis patients from ARDS patients.

Evaluation of Elafin Immunohistochemical Expression as Marker of Cervical Cancer Severity.

INTRODUCTION: The main risk factor for the development of cervical cancer (CC) is persistent infection by human papillomavirus (HPV) oncogenic types. In order to persist, HPV exhibits a plethora of immune evasion mechanisms. PI3/Elafin (Peptidase Inhibitor 3) is an endogenous serine protease inhibitor involved in epithelial protection against pathogens. PI3/Elafin's role in CC is still poorly understood. MATERIALS AND METHODS: In the present study, we addressed PI3/Elafin protein detection in 123 CC samples by immunohistochemistry and mRNA expression in several datasets available at Gene Expression Omnibus and The Cancer Genome Atlas platforms. RESULTS: We observed that PI3/Elafin is consistently downregulated in CC samples when compared to normal tissue. Most of PI3/Elafin-positive samples exhibited this protein at the plasma membrane. Besides, high PI3/Elafin expression at the cellular membrane was more frequent in in situ stages I + II than in invasive cervical tumor stages III + IV. This indicates that PI3/Elafin expression is gradually lost during the CC progression. Of note, advanced stages of CC were more frequently associated with a more intense PI3/Elafin reaction in the nuclei and cytoplasm. CONCLUSION: Our results suggest that PI3/Elafin levels and subcellular localization may be used as a biomarker for CC severity.

Expression of Elafin in Dermatitis Herpetiformis.

BACKGROUND: Elafin is a serine protease inhibitor that has various epithelial cell regulatory and immunomodulatory effects including inactivation of neutrophil elastases. This later role originated the interest of elafin in certain neutrophil-rich dermatoses. Interestingly, it has been speculated that elafin has a protective role by slowing the deamidation process of gliadin in celiac disease (CD), despite the typical absence of neutrophils in intestinal histologic samplings. Dermatitis herpetiformis (DH) is a chronic recurrent vesicular dermatitis associated with gluten hypersensitivity and also characterized by a neutrophilic infiltrate and granular immunoglobulin A deposits in papillary dermis. MATERIALS AND METHODS: We selected 31 formalin-fixed paraffin-embedded skin specimens of DH that demonstrated typical immunopathologic findings and probed them with rabbit polyclonal immunoglobulinG antielafin antibodies through standard immunohistochemistry analysis. Negative controls consisted of normal skin from elbow and knee surgical re-excisions specimen lacking residual tumor. Positive controls included skin biopsies of active plaque psoriasis, Sweet syndrome, and pyoderma gangrenosum. RESULTS: Similar to what has been previously reported in intestinal sampling of patients with active CD, abnormal expression of elafin was noted in virtually all probed skin biopsies of DH patients with active cutaneous disease. CONCLUSION: Under normal circumstances, keratinocytes overexpress elafin to downregulate a neutrophil mediated inflammatory response. The deficient expression of elafin in the aforementioned probed DH specimens correlates with previous similar elafin underexpression in intestinal samples of active CD. These histological findings suggest that these 2 gluten mediated disorders carry an abnormal elafin underexpression during disease activity.

High Expression of Antiviral Proteins in Mucosa from Individuals Exhibiting Resistance to Human Immunodeficiency Virus.

BACKGROUND: Several soluble factors have been reported to have the capacity of inhibiting HIV replication at different steps of the virus life cycle, without eliminating infected cells and through enhancement of specific cellular mechanisms. Yet, it is unclear if these antiviral factors play a role in the protection from HIV infection or in the control of viral replication. Here we evaluated two cohorts: i) one of 58 HIV-exposed seronegative individuals (HESNs) who were compared with 59 healthy controls (HCs), and ii) another of 13 HIV-controllers who were compared with 20 HIV-progressors. Peripheral blood, oral and genital mucosa and gut-associated lymphoid tissue (GALT) samples were obtained to analyze the mRNA expression of ELAFIN, APOBEC3G, SAMHD1, TRIM5α, RNase 7 and SerpinA1 using real-time PCR. RESULTS: HESNs exhibited higher expression of all antiviral factors in peripheral blood mononuclear cells (PBMCs), oral or genital mucosa when compared with HCs. Furthermore, HIV-controllers exhibited higher levels of SerpinA1 in GALT. CONCLUSIONS: These findings suggest that the activity of these factors is compartmentalized and that these proteins have a predominant role depending on the tissue to avoid the infection, reduce the viral load and modulate the susceptibility to HIV infection.

Expression of elafin in fallopian tubes of ectopic pregnancies is reduced.

Elafin is a natural antimicrobial molecule member of the antileukoproteinase (Trappin) family that is normally expressed in the mucosa of human fallopian tubes and neutrophils. Ectopic pregnancy is a condition in which neutrophil influx is present. Current data on elafin expression on fallopian tubes with ectopic pregnancy do not differentiate the expression of elafin in these 2 compartments. The objective of this study was to analyze the protein expression of elafin on epithelial mucosa of fallopian tubes with and without ectopic pregnancy using immunohistochemical analysis. Tissue sections of ectopic pregnancies (n=10) and normal tubes (n=10) were analyzed for the intensity of the staining with 3,3'-diaminobenzidine using ImageJ software. Statistical analysis was performed using unpaired t test and analysis of covariance. Elafin expression (mean ± SD) in the mucosa of fallopian tubes was 73.3 ± 19.7 (control) versus 48.9 ± 17.8 (ectopic pregnancy) (P=0.009). The immunoexpression of elafin is reduced in tubal epithelium of ectopic pregnancies, compared with nonectopic pregnancy tubes.

Elafin expression in mucosa of fallopian tubes is altered by hydrosalpinx.

Elafin is a natural antimicrobial molecule and a member of the antileukoproteinase (Trappin) family. It is normally expressed in the mucosae of fallopian tubes. Hydrosalpinx is a chronic inflammatory process of the fallopian tubes. The objective of this study is to compare the localization of elafin protein and levels of elafin messenger RNA (mRNA) in the mucosa of oviducts with and without hydrosalpinx. Immunohistochemical analysis was performed on tissue sections of hydrosalpinx (n = 10) and normal tubes (n = 22) from paraffin-embedded blocks, obtained from patients who underwent salpingectomy for benign conditions. The main outcome measure was the intensity of staining with 3,3'-diaminobenzidine calculated by ImageJ software and mRNA expression by real-time polymerase chain reaction. The mean intensity of elafin (mean ± standard deviation) in mucosae of the fallopian tubes was 69.68 ± 24.55 in controls and 32.03±18.16 in patients with hydrosalpinx (P < .0001). Elafin mRNA levels were reduced in hydrosalpinx, although not significantly (P = .05, n = 9 from each group). Therefore, tubal epithelium of women with hydrosalpinx seems to have a lower expression of elafin, an elastase inhibitor and a natural antimicrobial molecule, compared to normal tubes.

Periodontal treatment downregulates protease-activated receptor 2 in human gingival crevicular fluid cells.

Protease-activated receptor 2 (PAR2) is implicated in the pathogenesis of chronic inflammatory diseases, including periodontitis; it can be activated by gingipain and produced by Porphyromonas gingivalis and by neutrophil protease 3 (P3). PAR2 activation plays a relevant role in inflammatory processes by inducing the release of important inflammatory mediators associated with periodontal breakdown. The effects of periodontal treatment on PAR2 expression and its association with levels of proinflammatory mediators and activating proteases were investigated in chronic periodontitis patients. Positive staining for PAR2 was observed in gingival crevicular fluid cells and was reflective of tissue destruction. Overexpression of PAR2 was positively associated with inflammatory clinical parameters and with the levels of interleukin-6 (IL-6), IL-8, tumor necrosis factor alpha, matrix metalloprotease 2 (MMP-2), MMP-8, hepatocyte growth factor, and vascular endothelial growth factor. Elevated levels of gingipain and P3 and decreased levels of dentilisin and the protease inhibitors secretory leukocyte protease inhibitor and elafin were also associated with PAR2 overexpression. Healthy periodontal sites from individuals with chronic periodontitis showed diminished expression of PAR2 mRNA and the PAR2 protein (P < 0.05). Furthermore, periodontal treatment resulted in decreased PAR2 expression and correlated with decreased expression of inflammatory mediators and activating proteases. We concluded that periodontal treatment resulted in decreased levels of proteases and that proinflammatory mediators are associated with decreased PAR2 expression, suggesting that PAR2 expression is influenced by the presence of periodontal infection and is not a constitutive characteristic favoring periodontal inflammation.

The influence of hydrosalpinx on endometrial elafin expression.

The endometrium of women with hydrosalpinx has an increased number of neutrophils and lower expression of elafin, an elastase inhibitor and natural antimicrobial molecule. These findings suggest that women with hydrosalpinx have a reduced antimicrobial and antielastase activity.