RESUMEN
INTRODUCTION: Hyaluronan (HA) is a major component of the skin that exerts a variety of biological functions. Inter-α-trypsin inhibitor heavy chain (ITIH) proteins comprise a family of hyaladherins of which ITIH5 has recently been described in skin, where it plays a functional role in skin morphology and inflammatory skin diseases including allergic contact dermatitis (ACD). OBJECTIVE: The current study focused on the ITIH5-HA interaction and its potential clinical and functional impact in extracellular matrix (ECM) stabilization. METHODS: Studying the molecular effects of ITIH5 in skin, we established skin models comprising murine skin cells of Itih5 knockout mice and corresponding wild-type controls. In addition, human dermal fibroblasts with an ITIH5 knockdown as well as a murine recombinant Itih5 protein were established to examine the interaction between ITIH5 and HA using in vitro adhesion and HA degradation assays. To understand more precisely the role of ITIH5 in inflammatory skin diseases such as ACD, we generated ITIH5 knockout cells of the KeratinoSens® cell line. RESULTS: Using murine skin models, ITIH5 knockdown fibroblasts, and a reactive oxygen species (ROS)-mediated HA degradation assay, we proved that ITIH5 binds to HA, thereby acting as a stabilizer of HA. Moreover, microarray profiling revealed the impact of ITIH5 on biological processes such as skin development and ECM homeostasis. Performing the in vitro KeratinoSens skin sensitization assay, we detected that ITIH5 decreases the sensitizing potential of moderate and strong contact sensitizers. CONCLUSION: Taken together, our experiments revealed that ITIH5 forms complexes with HA, thereby on the one hand stabilizing HA and facilitating the formation of ECM structures and on the other hand modulating inflammatory responses.
Asunto(s)
Dermatitis Alérgica por Contacto/metabolismo , Fibroblastos/metabolismo , Ácido Hialurónico/metabolismo , Proteínas Inhibidoras de Proteinasas Secretoras/metabolismo , Piel/metabolismo , Animales , Adhesión Celular , Células Cultivadas , Dermatitis Alérgica por Contacto/genética , Dermatitis Alérgica por Contacto/patología , Eugenol/farmacología , Matriz Extracelular/metabolismo , Fibroblastos/patología , Humanos , Ratones Endogámicos BALB C , Ratones Noqueados , Unión Proteica , Proteínas Inhibidoras de Proteinasas Secretoras/deficiencia , Proteínas Inhibidoras de Proteinasas Secretoras/genética , Piel/patología , Tiazoles/farmacologíaRESUMEN
PURPOSE: Female reproductive events, including ovulation, menstruation, implantation, and delivery, are physiologically characterized by deep tissue remodeling and display hallmark signs of inflammation. This review discusses the pleiotropic roles played by bikunin in human reproduction. METHODS: A comprehensive literature search of the Medline/PubMed database was performed on the following topics: bikunin structure, roles in pathophysiological conditions and involvement in human reproduction, and usefulness as a marker of gestational complications or as a drug to improve pregnancy outcomes. RESULTS: Bikunin is a small chondroitin sulfate proteoglycan found in blood, urine, and amniotic and cerebrospinal fluids, known for its anti-inflammatory and anti-proteolytic activities. Its levels are usually low, but they can increase several-fold in both acute and chronic inflammatory diseases. Bikunin plays key roles in reproductive events, such as cumulus-oocyte complex formation, pregnancy, and delivery. Its levels have been associated with the most common pregnancy complications such as preterm delivery, pre-eclampsia, and gestational diabetes mellitus. Finally, its intravaginal administration has been reported to reduce the risk of preterm delivery and to improve neonatal outcomes. CONCLUSIONS: Because of its pleiotropic roles in several reproductive events and its association with some life-threatening pathological conditions of pregnancy, bikunin may represent a non-invasive marker for improving follow-up and early diagnosis. Studies showing its usefulness as a drug for reducing the risk of preterm delivery and improving neonatal outcomes have yielded interesting results that deserve to be investigated through further research.
Asunto(s)
alfa-Globulinas/metabolismo , alfa-Globulinas/uso terapéutico , Proteoglicanos Tipo Condroitín Sulfato/metabolismo , Trabajo de Parto Prematuro/tratamiento farmacológico , Complicaciones del Embarazo/metabolismo , Inhibidores de Proteasas/uso terapéutico , Fenómenos Fisiológicos Reproductivos , Femenino , Humanos , EmbarazoRESUMEN
Bioprosthetic heart valves (BHVs), derived from glutaraldehyde crosslinked (GLUT) porcine aortic valve leaflets or bovine pericardium (BP), are used to replace defective heart valves. However, valve failure can occur within 12-15 years due to calcification and/or progressive structural degeneration. We present a novel fabrication method that utilizes carbodiimide, neomycin trisulfate, and pentagalloyl glucose crosslinking chemistry (TRI) to better stabilize the extracellular matrix of BP. We demonstrate that TRI-treated BP is more compliant than GLUT-treated BP. GLUT-treated BP exhibited permanent geometric deformation and complete alteration of apparent mechanical properties when subjected to induced static strain. TRI BP, on the other hand, did not exhibit such permanent geometric deformations or significant alterations of apparent mechanical properties. TRI BP also exhibited better resistance to enzymatic degradation in vitro and calcification in vivo when implanted subcutaneously in juvenile rats for up to 30 days.
Asunto(s)
Bioprótesis , Carbodiimidas/farmacología , Reactivos de Enlaces Cruzados/farmacología , Fijadores/farmacología , Implantación de Prótesis de Válvulas Cardíacas/instrumentación , Prótesis Valvulares Cardíacas , Taninos Hidrolizables/farmacología , Neomicina/farmacología , Pericardio/efectos de los fármacos , Pericardio/trasplante , Fijación del Tejido/métodos , Animales , Fenómenos Biomecánicos , Calcinosis/etiología , Calcinosis/patología , Bovinos , Glutaral/farmacología , Supervivencia de Injerto , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Xenoinjertos , Masculino , Ratas Sprague-Dawley , Resistencia a la Tracción , Factores de Tiempo , Trasplante HeterólogoRESUMEN
Transglutaminases (denoted TG or TGM) are externalized from cells via an unknown unconventional secretory pathway. Here, we show for the first time that purinergic signaling regulates active secretion of TG2 (also known as TGM2), an enzyme with a pivotal role in stabilizing extracellular matrices and modulating cell-matrix interactions in tissue repair. Extracellular ATP promotes TG2 secretion by macrophages, and this can be blocked by a selective antagonist against the purinergic receptor P2X7 (P2X7R, also known as P2RX7). Introduction of functional P2X7R into HEK293 cells is sufficient to confer rapid, regulated TG2 export. By employing pharmacological agents, TG2 release could be separated from P2X7R-mediated microvesicle shedding. Neither Ca(2+) signaling alone nor membrane depolarization triggered TG2 secretion, which occurred only upon receptor membrane pore formation and without pannexin channel involvement. A gain-of-function mutation in P2X7R associated with autoimmune disease caused enhanced TG2 externalization from cells, and this correlated with increased pore activity. These results provide a mechanistic explanation for a link between active TG2 secretion and inflammatory responses, and aberrant enhanced TG2 activity in certain autoimmune conditions.