Researchers are one step closer to
unravelling why salivary glands stop working because of disease or
damage from treatment of diseases.
Salivary glands are essential for lubrication, defence and
beginning digestion in the mouth. The largest of the salivary glands,
the parotid, secretes important proteins into the saliva.
Douglas Darling, professor in oral health and rehabilitation at
the University of Louisville School of Dentistry, and his team have
identified a protein sorting mechanism used by the salivary gland.
The discovery could open the way to advanced therapies for patients
with damaged or dysfunctional salivary glands because of radiation
therapy, prescription drugs or Sjogren's Syndrome, defined by two most
common symptoms - dry eyes and a dry mouth.
As with all salivary glands, the parotid has multiple secretion
pathways. Therefore, it must sort proteins destined for saliva into the
correct pathway for secretion. This can be tricky as there are seven
possible pathways, reports the Journal of Dental Research.
One pathway takes proteins to the salivary duct, other pathways carry
different proteins to the 'back' side of the cell to be secreted into
the blood or to form a supportive matrix for the cells.
Transport along these pathways occurs by sorting the proteins
into vesicles (hollow membrane sacs) that carry their 'cargo' to the
correct destination, according to a Louisville statement.
Conventional thought was that cargo proteins are moved into the forming vesicles by attaching to sorting receptor proteins.
Darling and his team suggest the reason no salivary sorting receptor protein has been found is that it may not exist. IANS
