KINATEST-ID: a pipeline to develop phosphorylation-dependent terbium sensitizing kinase assays

Nonreceptor protein tyrosine kinases (NRTKs) are essential for cellular homeostasis and thus are a major focus of current drug discovery efforts. Peptide substrates that can enhance lanthanide ion luminescence upon tyrosine phosphorylation enable rapid, sensitive screening of kinase activity, however design of suitable substrates that can distinguish between tyrosine kinase families is a huge challenge. Despite their different substrate preferences, many NRTKs are structurally similar even between families. Furthermore, the development of lanthanide-based kinase assays is hampered by incomplete understanding of how to integrate sequence selectivity with metal ion binding, necessitating laborious iterative substrate optimization. We used curated proteomic data from endogenous kinase substrates and known Tb(3+)-binding sequences to build a generalizable in silico pipeline with tools to generate, screen, align, and select potential phosphorylation-dependent Tb(3+)-sensitizing substrates that are most likely to be kinase specific. We demonstrated the approach by developing several substrates that are selective within kinase families and amenable to high-throughput screening (HTS) applications. Overall, this strategy represents a pipeline for developing efficient and specific assays for virtually any tyrosine kinase that use HTS-compatible lanthanide-based detection. The tools provided in the pipeline also have the potential to be adapted to identify peptides for other purposes, including other enzyme assays or protein-binding ligands.

Affective neural response to restricted interests in autism spectrum disorders

BACKGROUND

Restricted interests are a class of repetitive behavior in autism spectrum disorders (ASD) whose intensity and narrow focus often contribute to significant interference with daily functioning. While numerous neuroimaging studies have investigated executive circuits as putative neural substrates of repetitive behavior, recent work implicates affective neural circuits in restricted interests. We sought to explore the role of affective neural circuits and determine how restricted interests are distinguished from hobbies or interests in typical development.

METHODS

We compared a group of children with ASD to a typically developing (TD) group of children with strong interests or hobbies, employing parent report, an operant behavioral task, and functional imaging with personalized stimuli based on individual interests.

RESULTS

While performance on the operant task was similar between the two groups, parent report of intensity and interference of interests was significantly higher in the ASD group. Both the ASD and TD groups showed increased BOLD response in widespread affective neural regions to the pictures of their own interest. When viewing pictures of other children's interests, the TD group showed a similar pattern, whereas BOLD response in the ASD group was much more limited. Increased BOLD response in the insula and anterior cingulate cortex distinguished the ASD from the TD group, and parent report of the intensity and interference with daily life of the child's restricted interest predicted insula response.

CONCLUSIONS

While affective neural network response and operant behavior are comparable in typical and restricted interests, the narrowness of focus that clinically distinguishes restricted interests in ASD is reflected in more interference in daily life and aberrantly enhanced insula and anterior cingulate response to individuals' own interests in the ASD group. These results further support the involvement of affective neural networks in repetitive behaviors in ASD.

Continuation of metformin in the first trimester of women with polycystic ovarian syndrome is not associated with increased perinatal morbidity

This study aimed to assess the perinatal outcome, especially foetal growth, following the continuation of metformin during the first trimester of pregnancy. All women with polycystic ovary syndrome (PCOS) treated with metformin in the first trimester and who delivered a baby weighing 500 g or more between 2003 and 2005 were studied. Subjects were matched for age and parity with randomly selected controls. The perinatal outcomes studied were: growth parameters, gestational age, congenital defects, hypoglycaemia and neonatal unit admission. Sixty-six pregnancies were compared with 66 controls; all had singleton deliveries. There was no difference in mean birth weight between the metformin and the control groups (p=0.84). The percentage of small (<10th centile) and large (>90th centile) for gestational age babies was lower in the metformin group. In the metformin group, there were no major congenital malformations and 24% of the babies were admitted to the neonatal intensive care unit (NICU) compared with 27% of the babies in the control group (non-significant). Neonatal hypoglycaemia was less common in the metformin group (18.5% vs. 24.5%) and fewer babies required intravenous glucose therapy (6.3% vs. 12%). We found no evidence that the continuation of metformin in the first trimester of pregnancy was associated with an adverse foetal outcome.