The biology of RAGE and its ligands: Uncovering mechanisms at the heart of diabetes and its complications

The interaction of glucose-modified and inflammation-promoting ligands with the receptor for advanced glycation end products (RAGE) is emerging as a central mechanism contributing to the diverse complications of diabetes. These ligands, particularly in oligomeric form, bind to RAGE and transduce intracellular signals. The consequences of this interaction, as elucidated in cultured cells and animal models, include upregulation of inflammatory and tissue-degradative pathways. Pharmacologic antagonism of RAGE may hold promise for the treatment of diabetic complications.     

Effect of early caffeine on neurodevelopmental outcome of very low-birth weight newborns

Objectives: The objective of this study is to evaluate the effect of early caffeine therapy started within the first 48?h of life on neurodevelopmental outcome in very low birth weight (VLBW) newborns.

Study design: VLBW newborns received either caffeine therapy within first 48?h of life (Early group), after 3rd day of life (Late group) or no caffeine during first month of life as per clinical team. A cohort of these newborns (n?=?160) who survived were evaluated using Bayley Scale of Infant Development III (BSID III) developmental testing between 18 and 22 months of corrected age.

Results: VLBW newborns in the “Early group” had significantly better composite, cognitive, language and motor BSID III scores as compared to those in “Late group” and no caffeine group. Composite BSID III scores were unchanged in the presence or absence of chorioamnionitis for “Early group”, while the BSID III scores were significantly lower in the presence of acute chorioamnionitis in “Late group” and no caffeine group.

Conclusions: Early caffeine therapy was associated with better BSID III scores in a cohort of VLBW newborns. Newborns with acute chorioamnionitis benefited from early caffeine therapy.     

Apoptotic cells trigger a membrane-initiated pathway to increase ABCA1

Macrophages clear millions of apoptotic cells daily and, during this process, take up large quantities of cholesterol. The membrane transporter ABCA1 is a key player in cholesterol efflux from macrophages and has been shown via human genetic studies to provide protection against cardiovascular disease. How the apoptotic cell clearance process is linked to macrophage ABCA1 expression is not known. Here, we identified a plasma membrane–initiated signaling pathway that drives a rapid upregulation of ABCA1 mRNA and protein. This pathway involves the phagocytic receptor brain-specific angiogenesis inhibitor 1 (BAI1), which recognizes phosphatidylserine on apoptotic cells, and the intracellular signaling intermediates engulfment cell motility 1 (ELMO1) and Rac1, as ABCA1 induction was attenuated in primary macrophages from mice lacking these molecules. Moreover, this apoptotic cell–initiated pathway functioned independently of the liver X receptor (LXR) sterol–sensing machinery that is known to regulate ABCA1 expression and cholesterol efflux. When placed on a high-fat diet, mice lacking BAI1 had increased numbers of apoptotic cells in their aortic roots, which correlated with altered lipid profiles. In contrast, macrophages from engineered mice with transgenic BAI1 overexpression showed greater ABCA1 induction in response to apoptotic cells compared with those from control animals. Collectively, these data identify a membrane-initiated pathway that is triggered by apoptotic cells to enhance ABCA1 within engulfing phagocytes and with functional consequences in vivo.     

Bile duct thrombi in hepatocellular carcinoma: is aggressive surgery worthwhile?

Introduction

Obstructive jaundice as a result of bile duct tumour thrombus (BDTT) is an unusual clinical entity and an uncommon presenting feature of hepatocellular carcinoma (HCC). This study evaluates the outcome of hepatectomy for HCC with obstructive jaundice as a result of BDTT in non-cirrhotic livers.

Methods

Between 1997 and 2012, out of 426 patients with HCC in non-cirrhotic livers, 39 patients with BDTT (Group I n = 39), who underwent a hepatectomy, were analysed and compared with the non-BDTT group (Group II n = 387).

Results

The demographic profile and biochemical parameters between Group I and Group II were compared; apart from the presence of jaundice at presentation and an elevated serum bilirubin, there were no significant differences. Post-operative morbidity and mortality were 11 (28.2%) and 2 (5.1%), respectively, in Group I. There were no differences between the groups with regards to the operative variables and short-term outcomes. The 1-, 3- and 5-year survival rates in Group I were 82%, 48% and 10%, respectively, with a median survival of 28.6 months and were significantly poorer than Group II (90%, 55% and 38%, respectively, with a median survival of 39.2 months).

Conclusion

The mere presence of BDTT in HCC does not indicate an advanced or inoperable lesion. When technically feasible, a formal hepatic resection is the preferred first-line treatment option in these patients.     

Receptor for advanced glycation end products and the cardiovascular complications of diabetes and beyond: lessons from AGEing.

The presence of elevated blood glucose levels characterizes the diabetic state. Hyperglycemia may be caused by a number of underlying factors; however, the consequences of chronically elevated glucose are similar. Both the macrovasculature and microvasculature are exquisitely sensitive to the long-term effects of elevated blood glucose. Cardiovascular disease remains the leading cause of morbidity and mortality in diabetes, regardless of the underlying cause of hyperglycemia. Although other substrates, such as DNA, are susceptible to glycation, this article addresses the impact of nonenzymatic glycation on the proteome. The impact of Advanced Glycation End products (AGEs) on alteration of protein function and signal transduction mechanisms contributes to the pathogenesis of diabetes complications. This suggests that blocking the generation or molecular impact of AGEs may modulate the complications of diabetes.