Tacrolimus-Induced BMP/SMAD Signaling Associates With Metabolic Stress-Activated FOXO1 to Trigger ß-Cell Failure.

Active maintenance of ß-cell identity through fine-tuned regulation of key transcription factors ensures ß-cell function. Tacrolimus, a widely used immunosuppressant, accelerates onset of diabetes after organ transplantation, but underlying molecular mechanisms are unclear. Here we show that tacrolimus induces loss of human ß-cell maturity and ß-cell failure through activation of the BMP/SMAD signaling pathway when administered under mild metabolic stress conditions. Tacrolimus-induced phosphorylated SMAD1/5 acts in synergy with metabolic stress-activated FOXO1 through formation of a complex. This interaction is associated with reduced expression of the key ß-cell transcription factor MAFA and abolished insulin secretion, both in vitro in primary human islets and in vivo in human islets transplanted into high-fat diet-fed mice. Pharmacological inhibition of BMP signaling protects human ß-cells from tacrolimus-induced ß-cell dysfunction in vitro. Furthermore, we confirm that BMP/SMAD signaling is activated in protocol pancreas allograft biopsies from recipients on tacrolimus. To conclude, we propose a novel mechanism underlying the diabetogenicity of tacrolimus in primary human ß-cells. This insight could lead to new treatment strategies for new-onset diabetes and may have implications for other forms of diabetes.

Vascular Damage and Kidney Transplant Outcomes: An Unfriendly and Harmful Link.

Kidney transplant (KT) is the treatment of choice for most patients with chronic kidney disease, but this has a high cardiovascular mortality due to traditional and nontraditional risk factors, including vascular calcification. Inflammation could precede the appearance of artery wall lesions, leading to arteriosclerosis and clinical and subclinical atherosclerosis in these patients. Additionally, mineral metabolism disorders and activation of the renin-angiotensin system could contribute to this vascular damage. Thus, understanding the vascular lesions that occur in KT recipients and the pathogenic mechanisms involved in their development could be crucial to optimize the therapeutic management and outcomes in survival of this population. This review focuses on the following issues: (1) epidemiological data framing the problem; (2) atheromatosis in KT patients: subclinical and clinical atheromatosis, involving ischemic heart disease, congestive heart failure, stroke and peripheral vascular disease; (3) arteriosclerosis and vascular calcifications; and (4) potential pathogenic mechanisms and their therapeutic targets.

Plasma matrix metalloproteinase 9 as an early surrogate biomarker of advanced colorectal neoplasia / Metaloproteinasa 9 como biomarcador plasmático de neoplasia colorrectal avanzada

INTRODUCTION: Matrix metalloproteinases (MMPs) are overexpressed at different stages of colorectal carcinogenesis and could serve as early surrogate biomarkers of colorectal neoplasia. OBJECTIVE: To assess the utility of plasma MMP2 and MMP9 levels in the detection of advanced colorectal neoplasia and their correlation with tissue levels. METHODS: We analysed blood and tissue samples from patients with non-advanced adenomas (n = 25), advanced adenomas (n = 25), colorectal cancer (n = 25) and healthy controls (n = 75). Plasma and tissue gelatinase levels were determined by Luminex XMAP technology and gelatin zymography. Receiver operating characteristic (ROC) curve analysis was used to calculate the optimum cut-off for the detection of advanced colorectal neoplasia. RESULTS: Plasma MMP2 levels were similar between groups whatever the type of lesion. Plasma MMP9 levels were significantly higher in patients with neoplastic lesions than in healthy controls (median 292.3 ng/ml vs. 139.08 ng/ml, P < 0.001). MMP9 levels were also higher in colorectal cancer than in non-advanced adenomas (median 314.6 ng/ml vs. 274.3 ng/ml, P = 0.03). There was a significant correlation between plasma and tissue levels of MMP9 (r =0.5, P < 0.001). The plasma MMP9 cut-off range with the highest diagnostic accuracy was between 173 ng/ml and 204 ng/ml (AUC = 0.80 [95% CI: 0.72-0.86], P < 0.001; sensitivity, 80-86% and specificity, 57-67%). CONCLUSION: Plasma MMP9 could be a surrogate biomarker for the early detection of advanced colorectal neoplasia, although its diagnostic performance could be increased by combination with other biomarkers

INTRODUCCIÓN: Las metaloproteinasas (MMP) son proteínas que se sobreexpresan en diferentes etapas de la carcinogénesis colorrectal y podrían ser biomarcadores de neoplasia colorrectal. OBJETIVO: Evaluar la utilidad de MMP2 y MMP9 en plasma para detectar neoplasia colorrectal avanzada y su correlación con los niveles tisulares. MÉTODOS: Se analizaron muestras de sangre y tejido en pacientes con adenomas no avanzados (n = 25), adenomas avanzados (n = 25), cáncer colorrectal (n = determinaron mediante tecnología xMAP Luminex y zimografía con gelatina. Se utilizaron curvas ROC para calcular el punto de corte óptimo para neoplasia colorrectal avanzada. RESULTADOS: Los niveles de MMP2 fueron similares en las distintas lesiones. Los niveles de MMP9 fueron significativamente superiores en los pacientes con lesiones neoplásicas comparados con controles sanos (mediana de 292,3 ng/ml vs. 139,08 ng/ml; p < 0,001). Los niveles de MMP9 fueron más altos en los cánceres colorrectales que en adenomas no avanzados (mediana de 314,6 ng/ml vs. 274,3 ng/ml; p = 0,03). Se observó correlación entre los niveles plasmáticos y tisulares de MMP9 (r = 0,5; p < 0,001). El rango de MMP9 plasma con mayor precisión diagnóstica fue 173-204 ng/ml (AUC = 0,80 [IC 95%: 0,72-0,86], p < 0,001; sensibilidad 80-86% y especificidad 57-67%). CONCLUSIÓN: Los niveles en plasma de MMP9 podrían ser un biomarcador útil para detectar neoplasia colorrectal avanzada. La combinación con otros biomarcadores podría aumentar su rendimiento diagnóstico

Plasma matrix metalloproteinase 9 as an early surrogate biomarker of advanced colorectal neoplasia.

INTRODUCTION: Matrix metalloproteinases (MMPs) are overexpressed at different stages of colorectal carcinogenesis and could serve as early surrogate biomarkers of colorectal neoplasia. OBJECTIVE: To assess the utility of plasma MMP2 and MMP9 levels in the detection of advanced colorectal neoplasia and their correlation with tissue levels. METHODS: We analysed blood and tissue samples from patients with non-advanced adenomas (n=25), advanced adenomas (n=25), colorectal cancer (n=25) and healthy controls (n=75). Plasma and tissue gelatinase levels were determined by Luminex XMAP technology and gelatin zymography. Receiver operating characteristic (ROC) curve analysis was used to calculate the optimum cut-off for the detection of advanced colorectal neoplasia. RESULTS: Plasma MMP2 levels were similar between groups whatever the type of lesion. Plasma MMP9 levels were significantly higher in patients with neoplastic lesions than in healthy controls (median 292.3ng/ml vs. 139.08ng/ml, P<0.001). MMP9 levels were also higher in colorectal cancer than in non-advanced adenomas (median 314.6ng/ml vs. 274.3ng/ml, P=0.03). There was a significant correlation between plasma and tissue levels of MMP9 (r=0.5, P<0.001). The plasma MMP9 cut-off range with the highest diagnostic accuracy was between 173ng/ml and 204ng/ml (AUC=0.80 [95% CI: 0.72-0.86], P<0.001; sensitivity, 80-86% and specificity, 57-67%). CONCLUSION: Plasma MMP9 could be a surrogate biomarker for the early detection of advanced colorectal neoplasia, although its diagnostic performance could be increased by combination with other biomarkers.

Glucose homeostasis changes and pancreatic ß-cell proliferation after switching to cyclosporin in tacrolimus-induced diabetes mellitus.

BACKGROUND: Switching to cyclosporine A may result in a reversion of tacrolimus-induced diabetes mellitus. However, mechanisms underlying such a reversion are still unknown. METHODS: Obese Zucker rats were used as a model for tacrolimus-induced diabetes mellitus. A cohort of 44 obese Zucker rats received tacrolimus for 11 days (0.3mg/kg/day) until diabetes development; then: (a)22 rats were euthanized at day 12 and were used as a reference group (tacrolimus-day 12), and (b)22 rats on tacrolimus were shifted to cyclosporin (2.5mg/kg/day) for 5 days (tacrolimus-cyclosporin). An additional cohort of 22 obese Zucker rats received the vehicle for 17 days and were used as a control group. All animals underwent an intraperitoneal glucose tolerance test at the end of the study. RESULTS: ß-cell proliferation, apoptosis and Ins2 gene expression were evaluated. Compared to rats in tacrolimus-day 12 group, those in tacrolimus-cyclosporin group showed a significant improvement in blood glucose levels in all assessment points in intraperitoneal glucose tolerance test. Diabetes decreased from 100% in tacrolimus-day 12 group to 50% in tacrolimus-cyclosporin group. Compared to tacrolimus-day 12 group, rats in tacrolimus-cyclosporin group showed an increased ß-cell proliferation, but such an increase was lower than in rats receiving the vehicle. Ins2 gene expressions in rats receiving tacrolimus-cyclosporin and rats receiving the vehicle were comparable. CONCLUSION: An early switch from tacrolimus to cyclosporin in tacrolimus-induced diabetes mellitus resulted in an increased ß-cell proliferation and reversion of diabetes in 50% of cases.

Artery Wall Assessment Helps Predict Kidney Transplant Outcome.

BACKGROUND: Kidney transplant recipients have high cardiovascular risk, and vascular inflammation may play an important role. We explored whether the inflammatory state in the vessel wall was related to carotid intima-media thickness (c-IMT) and patient survival following kidney transplantation. METHODS: In this prospective observational cohort study we measured c-IMT and expression of proinflammatory cytokines and adhesion molecules in the inferior epigastric artery in 115 kidney transplant candidates. Another c-IMT measurement was done 1-year post-transplantation in 107. By stepwise multiple regression analysis we explored factors associated with baseline c-IMT and their changes over time. Multivariate Cox regression analysis was constructed to identify risk factors for mortality. RESULTS: A worse cardiovascular profile (older age, smoker, diabetic, carotid plaque, systolic blood pressure and vascular calcification) and higher VCAM-1 levels were found in patients in the highest baseline c-IMT tertile, who also had a worse survival. Factors independently related to baseline c-IMT were age (ß=0.369, P<0.0001), fasting glucose (ß=0.168, P=0.045), smoking (ß=0.228, P=0.003) and VCAM-1 levels (ß=0.244, P=0.002). Independent factors associated with c-IMT measurement 1-year post-transplantation were baseline c-IMT (ß=-0.677, P<0.0001), post-transplant diabetes (ß=0.225, P=0.003) and triglycerides (ß=0.302, P=0.023). Vascular VCAM-1 levels were associated with increased risk of mortality in bivariate and multivariate Cox regression. Notably, nearly 50% of patients showed an increase or maintenance of high c-IMT 1 year post-transplantation and these patients experienced a higher mortality (13 versus 3.5%; P=0.021). CONCLUSION: A worse cardiovascular profile and a higher vascular VCAM-1 protein levels at time of KT are related to subclinical atheromatosis. This could lead to a higher post-transplant mortality. Pre-transplant c IMT, post-transplant diabetes and triglycerides at 1-year post-transplantation may condition a high c-IMT measurement post-transplantation, which may decrease patient survival.

Cambios en la homeostasis de la glucosa y la proliferación de la célula beta pancreática tras el cambio a ciclosporina en la diabetes inducida por tacrolimus / Glucose homeostasis changes and pancreatic beta-cell proliferation after switching to cyclosporin in tacrolimus-induced diabetes mellitus

Antecedentes: El cambio a ciclosporinaA podría revertir la diabetes inducida por tacrolimus. Sin embargo, los mecanismos de esta reversibilidad se desconocen. Métodos: Usamos como modelo de diabetes inducida por tacrolimus las ratas Zucker obesas. Un grupo de 44 ratas Zucker obesas fue tratado con tacrolimus durante 11 días (0,3mg/kg/día) hasta que desarrollaron diabetes; posteriormente, a)22 fueron sacrificadas a día 12 como grupo referencia (tacrolimus-d12), y b)en otras 22 el tacrolimus fue reemplazado por ciclosporina (2,5mg/kg/día) durante 5 días (tacrolimus-ciclosporina). Veintidós ratas Zucker obesas recibieron vehículo durante 17 días (grupo control). A todos los animales se les realizó una sobrecarga intraperitoneal de glucosa al final del experimento. Resultados: Se analizó la proliferación de la célulaβ, la apoptosis y la expresión del gen Ins2. En el grupo tacrolimus-ciclosporina, los niveles de glucemia mejoraron significativamente en cada punto del test intraperitoneal de glucosa comparados con el grupo tacrolimus-d12. La diabetes se redujo del 100% en los tacrolimus-d12 hasta el 50% en tacrolimus-ciclosporina. La proliferación de las células β en tacrolimus-ciclosporina se incrementó en comparación con tacrolimus-d12, pero fue menor que en los tratados con vehículo. La expresión génica de Ins2en tacrolimus-ciclosporina fue comparable a los tratados con el vehículo. Conclusión: El cambio temprano de tacrolimus por ciclosporina en la diabetes inducida por tacrolimus incrementa la proliferación de la célulaβ y revierte la diabetes en un 50% de los casos (AU)

Background: Switching to cyclosporinA may result in a reversion of tacrolimus-induced diabetes mellitus. However, mechanisms underlying such a reversion are still unknown. Methods: Obese Zucker rats were used as a model for tacrolimus-induced diabetes mellitus. A cohort of 44 obese Zucker rats received tacrolimus for 11 days (0.3mg/kg/day) until diabetes development; then: (a)22 rats were euthanized at day 12 and were used as a reference group (tacrolimus-day 12), and (b)22 rats on tacrolimus were shifted to cyclosporin (2.5mg/kg/day) for 5 days (tacrolimus-cyclosporin). An additional cohort of 22 obese Zucker rats received the vehicle for 17 days and were used as a control group. All animals underwent an intraperitoneal glucose tolerance test at the end of the study. Results: β-cell proliferation, apoptosis and Ins2 gene expression were evaluated. Compared to rats in tacrolimus-day 12 group, those in tacrolimus-cyclosporin group showed a significant improvement in blood glucose levels in all assessment points in intraperitoneal glucose tolerance test. Diabetes decreased from 100% in tacrolimus-day 12 group to 50% in tacrolimus-cyclosporin group. Compared to tacrolimus-day 12 group, rats in tacrolimus-cyclosporin group showed an increased β-cell proliferation, but such an increase was lower than in rats receiving the vehicle. Ins2 gene expressions in rats receiving tacrolimus-cyclosporin and rats receiving the vehicle were comparable. Conclusion: An early switch from tacrolimus to cyclosporin in tacrolimus-induced diabetes mellitus resulted in an increased β-cell proliferation and reversion of diabetes in 50% of cases (AU)

Type 1 diabetes increases the expression of proinflammatory cytokines and adhesion molecules in the artery wall of candidate patients for kidney transplantation.

OBJECTIVE: Diabetes may accelerate atheromatosis in uremic patients. Our aim was to assess the influence of type 1 diabetes on the atheromatosis-related inflammation in patients with chronic kidney disease (CKD). RESEARCH DESIGN AND METHODS: We analyzed the expression of proinflammatory cytokines and adhesion molecules in the inferior epigastric artery walls of type 1 diabetic patients with CKD (n = 22) and compared it with nondiabetic uremic patients (n = 92) at the time of kidney transplantation. We evaluated the expression of interleukin (IL)-6, monocyte chemotractant protein (MCP)-1, vascular cell adhesion molecule (VCAM)-1, intercellular adhesion molecule-1, and the activation of nuclear factor-κß p65 (NFkB-p65). Common carotid intima-media thickness (c-IMT) was determined by conventional echography. RESULTS: IL-6, MCP-1, and VCAM-1 proteins were elevated in type 1 diabetic patients compared with nondiabetic subjects (P < 0.05). The nuclear localization of NFkB-p65 was higher in type 1 diabetic patients (P < 0.01) and correlated with the levels of MCP-1 in this group (r = 0.726, P < 0.001). Arterial fibrosis correlated with IL-6 and MCP-1 levels (r = 0.411, P < 0.001 and r = 0.378, P = 0.001). A significant correlation was observed between VCAM-1 levels and both the degree of arterial narrowing and c-IMT. CONCLUSIONS: Type 1 diabetes produces a proinflammatory state in the arteries of end-stage CKD patients, with increased levels of IL-6, MCP-1, and VCAM-1, as well as a greater degree of p65 activation, which are associated with more severe vascular lesions and higher c-IMT. Although causality is not demonstrated, these findings support the major role of inflammation in type 1 diabetic patients with CKD.