Title:Impact of Diabetes in Blood-Testis and Blood-Brain Barriers: Resemblances and Differences
Volume: 8
Issue: 6
Author(s): Marco G. Alves, Pedro F. Oliveira, Silvia Socorro and Paula I. Moreira
Affiliation:
Keywords:
Diabetes, blood-brain barrier, blood-testis barrier, glucose metabolism, Sertoli cells, insulin, brain, hypertension, hypoglycemia, ionic changes, prostaglandins.
Abstract: Blood-tissue barriers prevent an uncontrolled exchange of large molecules between adjacent but metabolically
separated compartments. There are several known barriers and two of the most important and tightest blood-tissue barriers
are the blood-testis barrier (BTB) and the blood-brain barrier (BBB). Under normal conditions these barriers, formed by
tight junctions between adjacent cells, control the entry of substances and metabolites. However, hyperglycemia and other
diabetes-related complications, such as hypertension, impair the function of these biological barriers with dramatic consequences.
Although both, BBB and BTB, are responsible for the maintenance of different biological processes, they have
some remarkable similarities not always explored when looking at metabolic-related diseases such as diabetes. These barriers
possess their own glucose sensing machinery, suffer a tied hormonal control and have specific mechanisms to counteract
hyper- and hypoglycemia. In BBB and BTB the insulin signaling is also distinct from other tissues and organs thus
evidencing their importance in protecting against or exacerbating the effects of diabetes on glucose metabolism. The control
of glucose and lactate levels in brain and testis highlights the role of these barriers in protecting against peripheral glucose
and lactate fluctuations that occur in the diabetic individual. We review the role of BBB and BTB in the control of
glucose and metabolic dysfunction caused by diabetes in the brain and seminiferous epithelium. Gaining a better understanding
of the molecular mechanisms through which glucose metabolism disrupts BBB and BTB function may highlight
new opportunities for the treatment of diabetic complications in brain and male reproductive function.
