Integrin Conformational Dynamics and Mechanotransduction

The function of the integrin family of receptors as central mediators of cell-extracellular matrix (ECM) and cell–cell adhesion requires a remarkable convergence of interactions and influences. Integrins must be anchored to the cytoskeleton and bound to extracellular ligands in order to provide firm adhesion, with force transmission across this linkage conferring tissue integrity. Integrin affinity to ligands is highly regulated by cell signaling pathways, altering affinity constants by 1000-fold or more, via a series of long-range conformational transitions. In this review, we first summarize basic, well-known features of integrin conformational states and then focus on new information concerning the impact of mechanical forces on these states and interstate transitions. We also discuss how these effects may impact mechansensitive cell functions and identify unanswered questions for future studies

Serum Concentrations of Trace Elements in Patients with Ulcerative Colitis

Introduction: Nutritional status of patients with inflammatory bowel disease is estimated to be lower than optimal. This study was designed to compare the serum level of some trace elements in patients with ulcerative colitis (UC). Materials and methods: This cross-sectional study was performed in 2015-2016, on 60 recently diagnosed UC patients (30 with active UC and 30 with inactive UC) who were recruited from registry of the Golestan Research Center of Gastroenterology and Hepatology (Gorgan, Iran) through simple random sampling. Thirty healthy individuals were also recruited as controls. Demographic data and disease activity index were recorded through a checklist. Serum levels of copper (Cu), zinc (Zn), selenium (Se) and magnesium (Mg) were measured by atomic absorption spectroscopy. Data were analyzed using SPSS 16 at significance level of 0.05. Results: Mean serum level of Cu in the patients (0.75±0.25 mg/L) was significantly lower than in the controls (1.11±0.3 mg/L) (P=0001). Similarly, mean serum level of Mg in the patients (15.84±4.3 mg/L) was significantly lower than in the controls (19.48±15.7 mg/L) (P=0.001). Mean serum level of Se was slightly higher among the UC patients, while mean serum level of Zn was slightly lower in the UC patients compared with the controls. Conclusions: Our results show that UC patients have significantly lower Cu and Mg levels compared to healthy individuals. However, serum Zn and Se levels do not differ significantly between the UC patients and the control individuals. Further studies are required to confirm the results of this study