Adenosine kinase inhibition selectively promotes rodent and porcine islet β-cell replication

Diabetes is a pathological condition characterized by relative insulin deficiency, persistent hyperglycemia, and, consequently, diffuse micro- and macrovascular disease. One therapeutic strategy is to amplify insulin-secretion capacity by increasing the number of the insulin-producing β cells without triggering a generalized proliferative response. Here, we present the development of a small-molecule screening platform for the identification of molecules that increase β-cell replication. Using this platform, we identify a class of compounds [adenosine kinase inhibitors (ADK-Is)] that promote replication of primary β cells in three species (mouse, rat, and pig). Furthermore, the replication effect of ADK-Is is cell type-selective: treatment of islet cell cultures with ADK-Is increases replication of β cells but not that of α cells, PP cells, or fibroblasts. Short-term in vivo treatment with an ADK-I also increases β-cell replication but not exocrine cell or hepatocyte replication. Therefore, we propose ADK inhibition as a strategy for the treatment of diabetes.Stem Cell and Regenerative Biolog

Genome-wide gene expression profiling identifies overlap with malignant adrenocortical tumours and novel mechanisms of inefficient steroidogenesis in familial ACTH-independent macronodular adrenal hyperplasia.

ACTH-independent macronodular adrenal hyperplasia (AIMAH) is a rare cause of sporadic or familial late-onset Cushing's syndrome. It is a cytologically benign disease, of unknown pathogenesis, and characterised by inefficient steroidogenesis, ascribed to differential cellular localisation of steroidogenic enzymes. The objectives were to determine the molecular mechanisms involved in the pathogenesis of familial AIMAH tumours and the mechanisms of their inefficient steroidogenesis. Using Affymetrix Human GeneChip® HumanGene 1.0 ST arrays, we compared the genome-wide gene expression profile of two AIMAH nodules from each of three affected siblings with normal adrenal cortex and analysed the data for differential expression and using Ingenuity Pathway Analysis, Gene Set Enrichment Analysis and Motif Activity Response Analysis. Expression profiling identified: (i) that amongst the most highly differentially expressed genes were ones known to have involvement in tumorigenesis and metastasis; (ii) enrichment for differentially expressed genes in sporadic AIMAH and other benign and malignant adrenocortical tumours and (iii) reduced activity of key transcriptional regulators (Steroidogenic factor-1, SF-1 and transcription factor Sp1, Sp1) of steroidogenic enzymes. Genome-wide gene expression studies of familial AIMAH nodules have identified overlap with malignant adrenocortical tumours, which is intriguing given the benign biological behaviour of these tumours. This requires further study. Novel mechanisms of inefficient steroidogenesis were also identified

New findings in pancreatic and intestinal endocrine development to advance regenerative medicine

Purpose of review: We highlight some of the major recent advances that have been made towards understanding the mechanisms that control endocrine differentiation and cell identity in the pancreas and intestine. Recent findings: Notch signaling plays a complex role in the fate choice between endocrine, duct, and acinar lineages in the developing pancreas. New approaches to dissecting the role of mesenchymal cells in the developing endocrine pancreas reveal inhibitory signals from the endothelium. Epigenetic mechanisms represent another layer of control over pancreatic development and [beta] cell identity. Further details on the transcriptional control of enteroendocrine cell development have emerged and revealed a surprising role for FoxO1 in restraining insulin expression in the gut. Incremental progress is being made in the field of directed differentiation of embryonic stem cells to pancreatic [beta] cells and the first reported differentiation of human embryonic stem cells into intestinal organoids containing enteroendocrine cells represents a major breakthrough. Summary: Greater knowledge of the fundamental processes controlling endocrine development in the pancreas and intestine has the potential to advance the field of regenerative medicine by providing a pathway to successfully create cell types of clinical interest.Stem Cell and Regenerative Biolog

Physicians’ Perspectives on Palliative Care for Patients With End‐Stage Liver Disease: A National Survey Study

Specialty palliative care (PC) is underused for patients with end-stage liver disease (ESLD). We sought to examine attitudes of hepatologists and gastroenterologists about PC for patients with ESLD. We conducted a cross-sectional survey of these specialists who provide care to patients with ESLD. Participants were recruited from the American Association for the Study of Liver Diseases membership directory. Using a questionnaire adapted from prior studies, we examined physicians' attitudes about PC and whether these attitudes varied based on patients' candidacy for liver transplantation. We identified predictors of physicians' attitudes about PC using linear regression. Approximately one-third of eligible physicians (396/1236, 32%) completed the survey. Most (95%) believed that centers providing care to patients with ESLD should have PC services, and 86% trusted PC clinicians to care for their patients. Only a minority reported collaborating frequently with inpatient (32%) or outpatient (11%) PC services. Most believed that when patients hear the term PC, they feel scared (94%) and anxious (87%). Most (83%) believed that patients would think nothing more could be done for their underlying disease if a PC referral was suggested. Physicians who believed that ESLD is a terminal condition (B = 1.09; P = 0.006) reported more positive attitudes about PC. Conversely, physicians with negative perceptions of PC for transplant candidates (B = -0.22; standard error = 0.05; P < 0.001) reported more negative attitudes toward PC. In conclusion, although most hepatologists and gastroenterologists believe that patients with ESLD should have access to PC, they reported rarely collaborating with PC teams and had substantial concerns about patients' perceptions of PC. Interventions are needed to overcome misperceptions of PC and to promote collaboration with PC clinicians for patients with ESLD

Congresspeople in the Courtroom: Analysis of the use of Constitutional Complaints by Members of Congress in Colombia 1992-2015

The relationship between legislative and judicial branches in constitutional democracies has been the subject of several academic debates. Nevertheless, this literature has made little reference to congresspeople’s role as active subjects in judicial scenarios, especially when they present complaints against legislation enacted during their incumbency. This study seeks to address the question of why members of the Colombian Congress make use of constitutional review to overturn laws that they took part in debating. Through the use of quantitative and qualitative analysis, this paper explains how the use of constitutional complaints by members of congress is not limited to a political strategy of opposition by independents and opposition parties, but also serves members of the governing coalition for at least three different purposes: i) to deviate from the political approach of the Executive bill when they do not agree with the contents or when the reforms affect the interests of their constituency; ii) to “clean up” Executive bills of content introduced by the opposition during the law-making process; and iii) to advance certain points of their own political agenda, avoiding the political cost of opposing the reform as it passes through the legislative process