'Lost cells' offer obesity clue

The ability of a cell to sense its position within a tissue may help explain why some people become obese, scientists believe.

An international team is focusing on an inherited syndrome that causes obesity in children, among other symptoms.

They suspect that part of the problem could be faults in cells in the part of the brain that controls appetite.

 

The cells may lack normal location sense and migrate to the wrong place, they told Nature Genetics.

The condition the researchers are studying is called Bardet-Biedl syndrome, or BBS, but they believe their work could shed light on obesity in general.

 

Children born with BBS are obese and go blind and develop kidney failure.

Past work has uncovered at least eight faulty genes that can cause the disorder, but it is still not clear exactly how.

 

Professor Peter Beales from University College London Institute of Child Health, working with colleagues from Canada, France and the US, has discovered a possible cell function that may go amiss in BBS.

By looking at a mouse model of BBS, they found there were problems with tiny hair-like projections

on cells, known as cilia.

 

These hairs are important for telling the cell where in the body it is positioned in relation to other cells. Without this function the cell can get lost.

They believe such malfunction could play a role in the symptoms of BBS and its related obesity.

Professor Beales said: "There could be problems with the cilia on neurons on the brain in areas such as the hypothalamus, the region involved in appetite control.

 

"If these are not functioning properly, neurons could end up in the wrong position."

He added: "Our research may facilitate the understanding of more common forms of childhood obesity."

 

Dr Bradley Yoda from the University of Alabama at Birmingham, US, said: "Until recently we've been missing the connection between how cilia may be involved in these pathologies and developmental abnormalities.

 

"The work by this group of investigators has provided some novel and important insights into this question by showing the involvement of the BSS proteins, which function in the cilia, in a pathway known as planer cell polarity (PCP).

 

"The PCP pathway has major influences on how cells orient themselves, how they migrate in an embryo and consequently on how the entire organism becomes arranged.

"Thus, their finding will help explain some of the severe phenotypes that result in cases where cilia function is disrupted."