👤 Heike Jacobi

Spinocerebellar ataxia type 3 (SCA3) is one of the most common dominantly inherited ataxias worldwide. Despite research advances, no approved disease-modifying treatment exists, and management focuses on symptom alleviation and functional capacity maximization. Symptomatic treatment guidelines are scarce, leaving decisions to physicians' discretion. The lack of studies on SCA3 symptom management hinders therapy standardization. The aim of this study was to investigate medication-usage patterns among SCA3 mutation carriers and controls included in the multicentric European Spinocerebellar Ataxia Type-3/Machado-Joseph Disease Initiative (ESMI) cohort. We conducted a retrospective cross-sectional analysis of the medication taken by ESMI participants enrolled in the study between 2016 and 2023. Medication being used at the most recent follow-up visit available was categorized according to the Anatomical Therapeutic Chemical system. Comparisons between groups were performed using nonparametric tests for continuous variables and Fisher's exact test for categorical variables. In addition, a retrospective longitudinal analysis was conducted to study the impact of medication subclasses on disease progression, using linear mixed-effects models adjusted for relevant covariates. A total of 474 participants were included, comprising 344 SCA3 mutation carriers and 130 controls. Compared with controls, SCA3 subjects took more vitamins, mineral supplements, muscle relaxants, and medications targeting the nervous system. Psychoanaleptics and vitamins were introduced early in the disease course, whereas most other subclasses were initiated in mid-to-late stages, coinciding with the onset of neurological symptoms. Substantial disparities in medication usage were observed across the study centers. None of the medication subclasses commonly used by patients with SCA3 showed a significant impact on disease progression. This is the first study to explore medication usage patterns in SCA3 mutation carriers. Our study provides a comprehensive overview of the medications administered in SCA3 and underscores the importance of collaborative efforts toward achieving standardized clinical practices in the management of this disease. Show less

Base editors can correct disease-causing genetic variants. After a neonate had received a diagnosis of severe carbamoyl-phosphate synthetase 1 deficiency, a disease with an estimated 50% mortality in early infancy, we immediately began to develop a customized lipid nanoparticle-delivered base-editing therapy. After regulatory approval had been obtained for the therapy, the patient received two infusions at approximately 7 and 8 months of age. In the 7 weeks after the initial infusion, the patient was able to receive an increased amount of dietary protein and a reduced dose of a nitrogen-scavenger medication to half the starting dose, without unacceptable adverse events and despite viral illnesses. No serious adverse events occurred. Longer follow-up is warranted to assess safety and efficacy. (Funded by the National Institutes of Health and others.). Show less

Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone that augments insulin secretion in pancreatic β-cells via its glucose-dependent insulinotropic polypeptide receptor (GIPR). Recent genome-wide association studies identified a single nucleotide variant (SNV) in the GIPR encoding gene (GIPR), rs1800437, that is associated with obesity and insulin resistance. In the present study, we tested whether GIPR variants contribute to obesity and disturb glucose homeostasis or diabetes in specific patient populations. Exon sequencing of GIPR was performed in 164 children with obesity and insulin resistance and in 80 children with paediatric-onset diabetes of unknown origin. The Study of Health in Pomerania (SHIP) cohort, comprising 8320 adults, was screened for the GIPR variant Arg217Leu. GIPR variants were expressed in COS-7 cells and cAMP production was measured upon stimulation with GIP. Cell surface expression was determined by ELISA. Protein homology modelling of the GIPR variants was performed to extract three-dimensional information of the receptor. A heterozygous missense GIPR variant Arg217Leu (rs200485112) was identified in a patient of Asian ancestry. Functional characterization of Arg217Leu revealed reduced surface expression and signalling after GIP challenge. The homology model of the GIPR structure supports the observed functional relevance of Arg217Leu. In vitro functional studies and protein homology modelling indicate a potential relevance of the GIPR variant Arg217Leu in receptor function. The heterozygous variant displayed partial co-segregation with diabetes. Based on these findings, we suggest that GIPR variants may play a role in disturbed glucose homeostasis and may be of clinical relevance in homozygous patients. Show less

Because dietary arachidonate (ARA) and its eicosanoid derivatives are major regulators of intestinal homeostasis and repair following injury, we evaluated the effects of dietary ARA on desaturation and elongation of (13)C-18:2(n-6) and mRNA abundance of Δ-6-desaturase (FADS2), elongase (ELOVL5), and Δ-5-desaturase (FADS1) in liver and intestine. Day-old pigs (n = 96) were fed milk-based formula containing 0, 0.5, 2.5, or 5% ARA or 5% eicosapentaenoic acid of total fatty acids for 4, 8, and 16 d. In liver, the desaturation rate [nmol/(g tissue⋅h)] of (13)C-18:2(n-6) to (13)C-18:3(n-6) decreased 56% between 4 and 16 d but was not affected by diet. Whereas accumulation in (13)C-20:3(n-6) also decreased with age by 67%, it increased linearly with increasing dietary ARA (P < 0.06). In comparison, intestinal flux was ~50% less than liver flux and was unaffected by age, but desaturation to (13)C-18:3(n-6) increased linearly (by 57%) in pigs fed ARA diets (P < 0.001), equaling the rate observed in sow-fed controls. In both liver and intestine, alternate elongation to (13)C-20:2(n-6) (via Δ-8-desaturase) was markedly elevated in pigs fed the 0% ARA diet compared with all other dietary treatments (P < 0.01). Transcript abundance of FADS2, ELOVL5, and FADS1 was not affected in liver by diet (P > 0.05) but decreased precipitously between birth and d 4 (~70%; P < 0.05). In contrast, intestinal abundance of FADS2 and FADS1 increased 60% from d 4 to 16. In conclusion, dietary ARA regulated the desaturase-elongase pathway in a tissue-specific manner. In liver, ARA had modest effects on (n-6) fatty acid flux, and intestinal FADS2 activity and mRNA increased. Additionally, hepatic flux decreased with postnatal age, whereas intestinal flux did not change. Show less