Understanding Saliva: Yesterday, to-day and to-morrow

Josie A. Beeley

ABSTD Amsterdam, April 2016

Saliva • The fluid which keeps our mouths healthy

• And our guts

• And our bodies too

“A little goes a long way”

“A little goes a long way”

“You don’t miss it until it’s gone”

(Leo Sreebny)

What has changed over 50 years?

•The basics have hardly changed at all •Those basics are still needed to understand saliva •Our understanding of saliva has been revolutionised •So what will the future hold?

Physical Properties of Saliva

• Parotid saliva – watery fluid

• Submandibular / sublingual – viscous!

Properties of Saliva

• Rheological - physical chemistry

• pH buffering – inorganic chemistry

• Ca++ buffering – biological chemistry

• Protective - immunology

• Modulation of flora – microbiology

What saliva are you working with?

• Duct Saliva?

• Parotid?

• Submandibular / Sublingual?

• Minor Gland?

• Mixed Saliva (Oral Fluid)?

• Do the authors know?

• Have they considered this?

Is albumin a major salivary protein?

YES /NO NO

Albumin in saliva is from crevicular fluid!

Proteins then (as seen on gels)…..

•Ptyalin (amylase)

•Lysozyme

•Gustin

•Not much else!

1980’s……………..

•EtOH accidentally omitted from destain •Only with Commassie Blue R-250 •Proine rich proteins revealed •Pink staining •Comprise 2/3 protein in duct saliva •Polymorphisms too!

(8 subjects)

1D - SDS PAGE of Human Parotid Saliva

Venn diagrams showing the overlapping peptide and protein identifications between

WS, parotid/SMSL,and plasma. (A) Peptide identifications; (B) protein identifications.

Yan et al., 2009.

2D gel for Mass Spectrometry……

Minor Proteins……. Minor in content But minor in role??

Dual function proteins…

•Gustin / carbonic anhydrase

•Statherin antimicrobial proteins

•PRP Ps1 tannin binding and Gp120 - AIDS

•Histatin 1 cyclic histatin 1 (1,000 more active than EGF!!)

Histatin 1 - another dual function molecule??

• Histatin 1 Linear 39-mer peptide with candicidal activity

Enhances wound healing (wound closure) S. aureus Sortase A cyclises the polypeptide

• Cyclic histatin 1 + G-G 1,000X more active (enhances cell spreading & migration

but not cell division)

(Enno Veerman et al., 2011)

And defensins in human saliva too!!!!

Xerostomia

•Little relation to aging

•Autoimmune disorders

•Salivary gland disease

•Radiotherapy

•Drug induced

•Etc.

The Future????? •Artificial salivas - gene cloning of salivary proteins?

•What is the true role of PRPs?

•Personalised polymorphisms so personalised oral therapies?

•Gene therapy?

•?????

A treatment for xerostomia ?

Keep

Integrated

Saliva teaching

Simple

Keep

Integrated

Saliva teaching

Simple