Effects of Transglutaminase 2 Inhibition on Ventilator-Induced Lung Injury

This study was performed to examine the role of transglutaminase 2 (TG2) in ventilator-induced lung injury (VILI). C57BL/6 mice were divided into six experimental groups: 1) control group; 2) lipopolysaccharide (LPS) group; 3) lung protective ventilation (LPV) group; 4) VILI group; 5) VILI with cystamine, a TG2 inhibitor, pretreatment (Cyst+VILI) group; and 6) LPV with cystamine pretreatment (Cyst+LPV) group. Acute lung injury (ALI) score, TG2 activity and gene expression, inflammatory cytokines, and nuclear factor-kappaB (NF-kappaB) activity were measured. TG2 activity and gene expression were significantly increased in the VILI group (P < 0.05). Cystamine pretreatment significantly decreased TG2 activity and gene expression in the Cyst+VILI group (P < 0.05). Inflammatory cytokines were higher in the VILI group than in the LPS and LPV groups (P < 0.05), and significantly lower in the Cyst+VILI group than the VILI group (P < 0.05). NF-kappaB activity was increased in the VILI group compared with the LPS and LPV groups (P < 0.05), and significantly decreased in the Cyst+VILI group compared to the VILI group (P = 0.029). The ALI score of the Cyst+VILI group was lower than the VILI group, but the difference was not statistically significant (P = 0.105). These results suggest potential roles of TG2 in the pathogenesis of VILI.

Enfermedad celiaca: estudio descriptivo en la Clínica Anglo Americana / Celiac disease: descriptive study in the Anglo American clinic

INTRODUCCIÓN: La enfermedad celiaca (EC) es una condición en la que la ingesta de gluten desencadena una respuesta de autoinmunidad que genera aplanamiento de las vellosidades intestinales causando malabsorción. La prevalencia mundial es de aproximadamente 1%. En nuestro país no es conocida MATERIALES Y MÉTODOS: Estudio retrospectivo, descriptivo y observacional realizado en la Clínica Angloamericana entre Septiembre del 2004 y Febrero 2012. Se revisaron las historias clínicas, reportes endoscópicos y reportes de biopsias duodenales de los pacientes con anti Transglutaminasa tisular (TTG) positiva, mayores de 18 años. Resultados: Se estudiaron 39 casos, siendo 26 (66.7%) mujeres y 13 (33.3%) varones. La edad media de diagnóstico fue 61.25 años. Los síntomas fueron diarrea crónica en 32 (82.1%), dolor abdominal en 22 (56.4%), distensión abdominal en 14 (35.9%) y otros en menor frecuencia. Ocho (20.5%) pacientes presentaron anemia. Solo 5 (12.8%) pacientes presentaron hallazgos endoscópicos compatibles con EC. La clasificación Marsh de las biopsias duodenales fueron 0: 5 (12.7%), I: 1 (2.6%), II: 0 (0%), III A: 20 (51.3%), III B: 12 (30.8%) y III C: 1 (2.6%). CONCLUSIONES: La EC debe ser considerada como diagnóstico diferencial de pacientes con síntomas gastrointestinales inespecíficos de larga data, teniendo en cuenta también sus manifestaciones extraintestinales. Para el diagnóstico debe utilizarse la anti TTG como prueba inicial y posteriormente realizar una biopsia duodenal para estadiaje.

BACKGROUND: Celiac disease (CD) is a condition in which gluten intake develops an autoimmune response genetaring intestinal villous atrophy, causing malabsorption. Prevalence worlwide is approximately 1%, in our country it is not known. MATERIAL AND METHODS: Retrospective, descriptive, observational study in Anglo American Clinic between September 2004 and February 2012. We reviewed the medical charts, upper Gl endoscopy reports and duodenal biopsy reports of all patients with positive anti TTG results, who were older than 18 years of age. RESULTS: We studied 39 cases, 26 (66.7%) women and 13 (33.3%) men. Mean age was 61.25 years. The symptoms were chronic diarrhea in 32 (82.1%), abdominal pain in 22 (56.4%), abdominal distention in 14 (35.9%), and others in lower frequency. Eight (20.5%) patients had anemia. Just 5 (12.8%) had upper endoscopy findings consistent with CD, and Marsh classification was: 0: 5 (12.7%), l: 1 (2.6%), ll: 0 (0%), llll A: 20 (51.3%), lll B: 12 (30.8%) y lll C: 1 (2.6%). CONCLUSIONS: CD should be considered as a differential diagnosis of patients with non-specific-long-term gastrointestinal symptoms, extraintestinal symptoms should also be taken into account. Diagnosis should be made with anti TTG as the initial test and posteriorly with a duodenal biopsy for staging.

A Novel Therapeutic Target in Inflammatory Uveitis: Transglutaminase 2 Inhibitor

PURPOSE: Our goal was to investigate the effects of inhibition of transglutaminase 2 (TGase 2) on endotoxin-induced uveitis (EIU) METHODS: EIU was induced in female Lewis rats by single footpad injections of 200 microgram of lipopolysaccharide (LPS). TGase 2 inhibitors were administered intraperitoneally 30 minutes before and at the time of LPS administration. Rats were sacrificed 24 hours after injection, and the effects of the TGase 2 inhibitors were evaluated by the number of intraocular inflammatory cells present on histologic sections and by measuring the TGase 2 activity and TGase products in the aqueous humor (AqH). TGase 2 substrates were also assayed in AqH from uveitis patients. RESULTS: Clinical indications of EIU, the number of cells present on histologic sections, and TGase 2 activity in AqH increased in a time-dependent manner, peaking 24 hours after LPS injection. Inflammation in EIU was significantly reversed by treatment with TGase inhibitors. A 23-kDa cross-linked TGase substrate was identified in the AqH from EIU rats and uveitis patients. MALDI-TOF analysis showed that this substrate in uveitis patients was human Ig kappa chain C region. CONCLUSIONS: TGase 2 activity and its catalytic product were increased in the AqH of EIU rats. TGase 2 inhibition attenuated the degree of inflammation in EIU. Safe and stable TGase inhibitors may have great potential for the treatment of inflammatory uveitis.

Different inhibition characteristics of intracellular transglutaminase activity by cystamine and cysteamine

The treatment of cystamine, a transglutaminase (TGase) inhibitor, has beneficial effects in several diseases including CAG-expansion disorders and cataract. We compared the inhibition characteristics of cystamine with those of cysteamine, a reduced form of cystamine expected to be present inside cells. Cystamine is a more potent inhibitor for TGase than cysteamine with different kinetics pattern in a non- reducing condition. By contrast, under reducing conditions, the inhibitory effect of cystamine was comparable with that of cysteamine. However, cystamine inhibited intracellular TGase activity more strongly than cysteamine despite of cytoplasmic reducing environment, suggesting that cystamine itself inhibits in situ TGase activity by forming mixed disulfides.

Calpain inhibitors reduce the cornified cell envelope formation by inhibiting proteolytic processing of transglutaminase 1

Calpain I (mu-calpain) and II (m-calpain) are well known calcium-activated neutral cysteine proteases. Many reports have shown that activation of calpain is related to cataract formation, neuronal degeneration, blood clotting, ischemic injuries, muscular dystrophy and cornified cell envelope (CE) formation. Here, we report that insoluble CE formation was reduced after treatment with calpain I inhibitor (N-acetyl-leucyl-leucyl-norleucinal) on normal human epidermal keratinocytes (NHEK), whereas serine and thiol protease inhibitors had no effect on the reduction of CE. When NHEK cells were confluent, keratinocytes were treated with various concentrations (0.5 microM-0.5 mM) of calpain I inhibitor or serine and thiol protease inhibitors under calcium induced differentiation. Insoluble CE formation was reduced about 90% in the 50 microM calpain inhibitor I treated group by day 9 of culture, whereas insoluble CE was reduced only 10% in the same condition. Interestingly TGase activity was blocked by 90% in the 0.5 mM calpain inhibitor treated group within 72 h, whereas TGase activity was retained by 80% in the 0.5 mM serine protease inhibitor treated group at 7 day treatment. Therefore it can be suggested that cysteine protease calpains might be responsible for the activation of the TGase 1 enzyme to complete insoluble CE formation during epidermal differentiation.