A recent study published by the group of Dr Natasha Hill in the journal Scientific Reports entitled ‘A holistic approach to dissecting SPARC family protein complexity reveals FSTL-1 as an inhibitor of pancreatic cell growth’ explores the complexity of the SPARC family of proteins and their role in the pancreas.
The first author of the study, Katrina Viloria is final year PhD student and she explains the main findings of the study:
“The SPARC family of proteins are matricellular proteins known to regulate the matrix and extracellular interaction with cells. SPARC proteins share structural and functional similarities and there is growing evidence of regulatory interactions within the family thus the pressing need for a holistic analysis of the SPARC family. SPARC is well known to be involved in pancreatic cancer and diabetes, however little is known about the extended family.
In this study, we show that Hevin, SPOCKs and SMOCs are strongly expressed in the pancreatic ducts, blood vessels, and in islets, particularly showing strong intracellular staining in islet cells, despite being secreted matricellular proteins. The SPARC family may therefore play important roles in islet growth and function. FSTL-1 on the other hand was localized to stromal cells, showing similar expression to SPARC. We show for the first time that FSTL-1 inhibits pancreatic cancer growth.
“We also detected multiple cell-type specific isoforms of the SPARC family in pancreatic cells. Further bioinformatics analysis revealed that the SPARC protein family is capable of extensive post translational modifications and alternative splicing, a process that produces multiple versions or isoforms from each protein. We also suggest for the first time that SPARC proteins may produce intracellular variants that lack a signal peptide which may have distinct roles in islet function. This study underlines the importance of addressing the complexity of the SPARC family in understanding their role in the pancreas particularly in islet function and diabetes.”
This study also follows on from a previous paper published by Katrina Viloria and Natasha Hill last year, which analysed the significance of alternative splicing in the wider matricellular protein family.