RESUMO
BACKGROUND: The ATP2B1 gene encodes for a calcium pump, which plays a role in removing Ca2+ from cells and maintaining intracellular Ca2+ homeostasis. Reduction of the intracellular Ca2+ concentration in CD4+ T cells is thought to reduce the severity of colitis, while elevation of Ca2+ in CD4+ T cells induces T cell hyperactivity. Our aim was to clarify the role of ATP2B1 in CD4+ T cells and in inflammatory bowel disease development. METHODS: A murine CD4+ T cell-specific knockout (KO) of ATP2B1 was created using a Cre-loxP system. CD4+ T cells were isolated from thymus, spleen, and blood using fluorescence-activated cell sorting. To quantify messenger RNA levels, quantitative real-time polymerase chain reaction was performed. RESULTS: Although the percentages of CD4+ T cells in both KO mouse spleen and blood decreased compared with those of the control samples, both T-bet (a T helper 1 [Th1] activity marker) and GATA3 (a Th2 activity marker) expression levels were further increased in KO mouse blood CD4+ T cells (vs control blood). Diarrhea and colonic wall thickening (with mucosal changes, including crypt distortion) were seen in KO mice but not in control mice. Prior to diarrhea onset, the KO mouse colon length was already noted to be shorter, and the KO mouse stool water and lipid content were higher than that of the control mice. Tumor necrosis factor α and gp91 expressions were increased in KO mouse colon. CONCLUSIONS: Lack of ATP2B1 in CD4+ T cells leads to Th1 and Th2 activation, which contributes to colitis via elevation of tumor necrosis factor α and oxidative stress.
ATP2B1 deficiency in CD4+ T cells leads to T helper 1/T helper 2 activation, which in turn increases tumor necrosis factor α and oxidative stress. These changes contribute to colitis, which is characterized by diarrhea and colonic wall thickening.
RESUMO
PURPOSE: Aiming at complete excision of cholesteatoma during trympanomastoidectomy and therefore reducing the risk of recurrence, intraoperative imaging techniques are required to assist the visualization of cholesteatoma residue. Galectin-7 has been demonstrated to be a biomarker for cholesteatoma matrix and used for intraoperatively identifying the excision margins. METHODS: A galectin-7-targeted DNA-aptamer library was generated for labeling the cholesteatoma matrix using cell-systematic evolution of ligands by an exponential enrichment technique. The binding characteristics of the identified aptamers were analyzed, and structure optimization of the identified aptamers was carried out both in silico and in vitro. FINDINGS: A fluorophore-labeled structure-optimized DNA fragment was commercially synthesized as a non-invasive aptamer-based probe for intraoperative lesion detection. Using galectin-7-aptamer-guided molecular imaging, the excision margins of cholesteatoma matrix and surrounding normal tissue were successfully achieved within 15-20 min. CONCLUSIONS: Galectin-7-targeted aptamers could benefit molecular imaging-guided surgical treatment, which would enable clinicians to not only intraoperatively detect the locations of cholesteatoma matrix in the middle ear, but also assess the postoperative response of the expression profile to therapy. It is highly expected that further efforts for rational design and development should be directed towards the development of clinically translatable aptamer-based imaging agents.