Mossner, J. | bioRxiv Science

bioRxiv2019

Genetic analysis of the STIM1 gene in chronic pancreatitis

Chronic pancreatitis is a complex disease that involves many factors, both genetic and environmental. Over the past two decades, molecular genetic analysis of five genes that are highly expressed in human pancreatic acinar cells, namely PRSS1, PRSS2, SPINK1, CTRC and CTRB1/CTRB2, has established that a trypsin-dependent pathway plays a key role in the etiology of chronic pancreatitis. Since Ca2+ deregulation can lead to intracellular trypsin activation in experimental acute pancreatitis, we analyzed STIM1 (encoding stromal interaction molecule-1, the main regulator of Ca2+ homeostasis in pancreatic acinar cells) as a candidate modifier gene in French, German and Chinese patients with chronic pancreatitis. The French and German subjects were analyzed by Sanger sequencing whereas the Chinese subjects were analyzed by targeted next-generation sequencing confirmed by Sanger sequencing. A total of 37 rare coding variants (35 missense and 2 nonsense) were identified, which were enriched in patients as compared with controls [2.28% (47/2,057) vs. 0.99% (33/3,322); odds ratio = 2.33, P = 0.0001]. This is the first large case-control study to demonstrate a putative association of rare STIM1 coding variants with chronic pancreatitis. Functional analysis will be required to clarify whether or not the rare STIM1 variants detected predispose to pancreatitis.

genetics↗

bioRxiv2017

Distinct contributions of three GABAergic interneuron populations to a mouse model of Rett Syndrome.

BackgroundRett Syndrome is a devastating neurodevelopmental disorder resulting from mutations in the gene MeCP2. MeCP2 is a transcriptional regulator active in many cell types throughout the brain. However, mutations of MeCP2 restricted to GABAergic cell types largely replicate the behavioral phenotypes associated with mouse models of Rett Syndrome, suggesting a key role for inhibitory interneurons in the pathophysiology underlying this disorder.\n\nMethodsWe generated conditional deletions of MeCP2 from each of three major classes of GABAergic interneurons, the parvalbumin (PV), somatostatin (SOM), and vasoactive intestinal peptide (VIP)-expressing cells, along with a pan-interneuron deletion from all three GABAergic populations. We examined seizure incidence, mortality, and performance on several key behavioral assays.\n\nResultsWe find that each interneuron class makes a contribution to the seizure phenotype associated with Rett Syndrome. PV, SOM, and VIP interneurons made partially overlapping contributions to deficits in motor behaviors. We find little evidence for elevated anxiety associated with any of the conditional deletions. However, MeCP2 deletion from VIP interneurons causes a unique deficit in marble burying. Furthermore, VIP interneurons make a distinct contribution to deficits in social behavior.\n\nConclusionsWe find an unanticipated contribution of VIP interneuron dysfunction to the MeCP2 loss-of-function model of Rett Syndrome. Together, our findings suggest a complex interaction between GABAergic dysfunction and behavioral phenotypes in this neurodevelopmental disorder.

neuroscience↗