👤 Leah Steinberg

Biased agonism of the glucagon-like peptide-1/glucose-dependent insulinotropic polypeptide receptors (GLP-1R/GIPR) yields greater weight loss and better glycemic control than unbiased agonism in preclinical models. To evaluate whether biased agonism translates into improved efficacy for weight loss and glycemic control in clinical settings, we developed and characterized CT-388, a unimolecular peptide-based dual GLP-1R/GIPR agonist that is cAMP signal-biased at both receptors. In cell-based assays, CT-388 activated GLP-1R and GIPR with both having minimal receptor internalization vs their native ligands. CT-388 improved glycemic control in mice and monkeys, and reduced bodyweight, suppressed appetite, and improved metabolic dysfunction-associated steatohepatitis pathology in mice. In a phase 1, double-blind, randomized, placebo-controlled clinical study (NCT04838405) of CT-388 (subcutaneously administered single doses [0.5-7.5 mg] or 4 once-weekly doses [5-12 mg]) in otherwise healthy participants with overweight or obesity, CT-388 was generally well tolerated with a safety profile consistent with other incretin-based therapies; most treatment-emergent adverse events were mild or moderate. Glycemic parameters were improved during fasting conditions and an oral glucose tolerance test. The mean percent change in bodyweight from baseline to day 29 was -4.7% to -8.0% across CT-388 doses vs -0.5% with placebo. CT-388 pharmacokinetics supported once-weekly dosing. In conclusion, CT-388 demonstrated strong translatability from preclinical to clinical studies with consistent pharmacokinetics and pharmacodynamics across multiple species. In clinical settings, 4 weeks of CT-388 treatment produced clinically meaningful weight loss and improved glycemic control with favorable tolerability. These findings warrant further clinical evaluation of CT-388 for treating obesity and type 2 diabetes. Show less

The assessment of serious illness communication (SIC) competence has, to date, primarily utilized tools that are profession-specific and not explicitly designed using competency-based or person-centered frameworks. To address these gaps, we developed and validated a new tool, the Assessment of Clinical Encounters - Communication Tool (ACE-CT). We convened a national panel of interprofessional SIC experts to develop and validate the ACE-CT using a three-phase multi-method approach. Phase 1 focused on item development through review of existing validated tools, and a Bayesian process in which panel members assessed item quality and item-domain correlation. Phase 2 involved item refinement and preliminary validation through stimulated recall interviews using a think-aloud technique. Phase 3 consisted of psychometric analyses for which panel members used the tool to assess video-recorded standardized patient encounters from interprofessional clinicians completing a SIC professional development intervention. In Phase 1, 37 relevant items from previously validated tools were identified, of which 11 items were removed due to redundance. Through the Bayesian process, 14 items were removed and 1 item was generated. Through Phase 2, 2 items were generated, 2 items were combined into 1, and remaining items were refined to optimize measurability and understandability. In Phase 3, reliability was demonstrated through evidence of high internal consistency and moderate reproducibility, both over time and across raters. The tool was found to be responsive and have sound construct validity through evidence of congruence, convergence and credibility. Raters found the tool to be intuitive, easy to complete, and that it accurately captured their perception of the quality of communication observed. The ACE-CT provides a reliable and valid approach to assessing SIC competence among interprofessional clinicians. Through its person-centered orientation, the ACE-CT provides an opportunity to objectively assess elements of SIC that patients and families value. Show less

Glucose-dependent insulinotropic polypeptide (GIP) communicates information on energy availability from the gut to peripheral tissues. Disruption of its signaling in myeloid immune cells during high-fat diet (HFD)-induced obesity impairs energy homeostasis due to the unrestrained metabolically deleterious actions of S100A8/A9 alarmin. White adipose tissue (WAT) type 2 immune cell networks are important for maintaining metabolic and energy homeostasis and limiting obesity-induced inflammation. Nevertheless, the consequences of losing immune cell GIP receptor (GIPR) signaling on type 2 immunity in WAT remains unknown. Bone marrow (BM) chimerism was used to generate mice with GIPR ( Show less

RAB GTPases are central modulators of membrane trafficking. They are under the dynamic regulation of activating guanine exchange factors (GEFs) and inactivating GTPase-activating proteins (GAPs). Once activated, RABs recruit a large spectrum of effectors to control trafficking functions of eukaryotic cells. Multiple proteomic studies, using pull-down or yeast two-hybrid approaches, have identified a number of RAB interactors. However, due to the Show less

The 17q21.31 inversion polymorphism exists either as direct (H1) or inverted (H2) haplotypes with differential predispositions to disease and selection. We investigated its genetic diversity in 2,700 individuals, with an emphasis on African populations. We characterize eight structural haplotypes due to complex rearrangements that vary in size from 1.08-1.49 Mb and provide evidence for a 30-kb H1-H2 double recombination event. We show that recurrent partial duplications of the KANSL1 gene have occurred on both the H1 and H2 haplotypes and have risen to high frequency in European populations. We identify a likely ancestral H2 haplotype (H2') lacking these duplications that is enriched among African hunter-gatherer groups yet essentially absent from West African populations. Whereas H1 and H2 segmental duplications arose independently and before human migration out of Africa, they have reached high frequencies recently among Europeans, either because of extraordinary genetic drift or selective sweeps. Show less

Recurrent deletions have been associated with numerous diseases and genomic disorders. Few, however, have been resolved at the molecular level because their breakpoints often occur in highly copy-number-polymorphic duplicated sequences. We present an approach that uses a combination of somatic cell hybrids, array comparative genomic hybridization, and the specificity of next-generation sequencing to determine breakpoints that occur within segmental duplications. Applying our technique to the 17q21.31 microdeletion syndrome, we used genome sequencing to determine copy-number-variant breakpoints in three deletion-bearing individuals with molecular resolution. For two cases, we observed breakpoints consistent with nonallelic homologous recombination involving only H2 chromosomal haplotypes, as expected. Molecular resolution revealed that the breakpoints occurred at different locations within a 145 kbp segment of >99% identity and disrupt KANSL1 (previously known as KANSL1). In the remaining case, we found that unequal crossover occurred interchromosomally between the H1 and H2 haplotypes and that this event was mediated by a homologous sequence that was once again missing from the human reference. Interestingly, the breakpoints mapped preferentially to gaps in the current reference genome assembly, which we resolved in this study. Our method provides a strategy for the identification of breakpoints within complex regions of the genome harboring high-identity and copy-number-polymorphic segmental duplication. The approach should become particularly useful as high-quality alternate reference sequences become available and genome sequencing of individuals' DNA becomes more routine. Show less

We identified a marker in LINGO1 showing genome-wide significant association (P = 1.2 x 10(-9), odds ratio = 1.55) with essential tremor. LINGO1 has potent, negative regulatory influences on neuronal survival and is also important in regulating both central-nervous-system axon regeneration and oligodendrocyte maturation. Increased axon integrity observed in Lingo1 mouse [corrected] knockout models highlights the potential role of LINGO1 in the pathophysiology of ET [corrected] Show less

Deletions within the neurexin 1 gene (NRXN1; 2p16.3) are associated with autism and have also been reported in two families with schizophrenia. We examined NRXN1, and the closely related NRXN2 and NRXN3 genes, for copy number variants (CNVs) in 2977 schizophrenia patients and 33 746 controls from seven European populations (Iceland, Finland, Norway, Germany, The Netherlands, Italy and UK) using microarray data. We found 66 deletions and 5 duplications in NRXN1, including a de novo deletion: 12 deletions and 2 duplications occurred in schizophrenia cases (0.47%) compared to 49 and 3 (0.15%) in controls. There was no common breakpoint and the CNVs varied from 18 to 420 kb. No CNVs were found in NRXN2 or NRXN3. We performed a Cochran-Mantel-Haenszel exact test to estimate association between all CNVs and schizophrenia (P = 0.13; OR = 1.73; 95% CI 0.81-3.50). Because the penetrance of NRXN1 CNVs may vary according to the level of functional impact on the gene, we next restricted the association analysis to CNVs that disrupt exons (0.24% of cases and 0.015% of controls). These were significantly associated with a high odds ratio (P = 0.0027; OR 8.97, 95% CI 1.8-51.9). We conclude that NRXN1 deletions affecting exons confer risk of schizophrenia. Show less