👤 James P Sanders

Identifying strategies to mitigate age-associated cognitive decline is crucial. High-velocity power training enhances physical function in older adults and cognitive training has mixed cognitive benefits, however the combined effects of these interventions remain uncertain. This 18-month cluster randomized controlled trial investigated whether dual-task functional power training (DT-FPT) enhances cognition in older adults and assessed if responses differ by apolipoprotein-E and brain-derived neurotrophic factor (BDNF) polymorphisms. Twenty-two independent-living retirement communities (300 residents, ≥65y at increased falls risk) were randomized to 12-months of group-based DT-FPT (6-months supervised +6-months maintenance, 45-60 minutes, 2/week) performed simultaneously with cognitive and/or motor tasks, followed by 6-months follow-up, or usual care control (CON). Cognitive domains were assessed using CogState at baseline, 6, 12 and 18-months. Z-scores were created to form composites for psychomotor-attention, learning-working memory and global cognition. BDNF and APOE polymorphism data were obtained from blood samples. Overall, 223 (74%) participants completed the 18-month intervention; mean exercise adherence was 50% at 6-months and 40% at 12-months. Net benefits in choice reaction time and attention (0.17 SD, P = 0.016), psychomotor-attention (0.19 SD, P = 0.029), and a composite of psychomotor-attention, learning-working memory (0.11 SD, P = 0.046) were detected in DT-FPT vs CON after the 6-month supervised phase. At 12 and 18 months, benefits from DT-FPT relative to CON were extended to visual learning (0.29 SD, P = 0.013; 0.27 SD, P = 0.008) and learning-working memory (0.13 SD, P = 0.047; 0.18 SD, P = 0.013). CON exhibited a 0.19 SD net benefit for executive function (P = 0.003) after 18 months. BDNF Met carriers at 18 months showed improved working memory (0.35 SD, P = 0.042) and learning-working memory (0.37 SD, P = 0.011) in DT-FPT versus CON. In older retirement living residents, DT-FPT may improve cognitive domains critical for functional independence, with genotype potentially influencing these outcomes.Australian New Zealand Clinical Trials Registry (ACTRN12613001161718). This project was funded by the National Health and Medical Research Council (NHMRC) (APP1046267). Show less

To understand the relative contributions of 5' UTR elements to translation output, we performed a comprehensive analysis of upstream open reading frames (uORFs) in the 5' UTRs of the BDNF (brain-derived neurotrophic factor) transcripts. Predicted uORFs were identified in 14 out of 17 BDNF RefSeq transcript isoforms, and we experimentally validated five of these transcripts as being uORF-repressed, suggesting that uORF elements play an important role in shaping the protein output from this locus. We explored several approaches to disrupt BDNF uORF function. Deletion of a 5' UTR exon in BDNF v11 (containing eight predicted uORFs), in order to simulate an exon skipping outcome, resulted in pronounced upregulation in a reporter construct system. This effect was found to be partially uORF-dependent but was also dependent on the disruption of an RNA secondary structure element. However, this transcript variant was found to not be expressed in human brain. Conversely, direct disruption of a single uORF start codon in the widely expressed BDNF v4 transcript variant using an adenine base editing approach resulted in a ∼1.8-fold upregulation of endogenous BDNF protein expression in cell culture. This study characterizes uORF-mediated regulation of the BDNF locus and demonstrates the potential for BDNF protein upregulation via base editing-mediated uORF disruption. Show less

Low-density lipoprotein cholesterol (LDL-C) levels <100 mg/dL are generally considered normal. We tested the controversial hypothesis that a subset of individuals with 'normal' LDL-C levels may have a non-negligible risk of coronary artery disease (CAD) due to inherited factors, including monogenic variants and polygenic risk scores (PGS). A retrospective analysis of a prospective cohort from the Genomic Health Initiative at Endeavor Health, including 7880 participants without a prior diagnosis of CAD and not on statins at recruitment. Participants were stratified by baseline LDL-C levels and followed for incident CAD. The association of CAD risk with carrier status for pathogenic/likely pathogenic (P/LP) variants in Among participants, 31.2 % had LDL-C <100 mg/dL (normal), 39.5 % had LDL-C 100-129 mg/dL, and 29.3 % had LDL-C ≥130 mg/dL. Over a median follow-up of 8 years, CAD was diagnosed in 5.3 %, 6.9 %, and 7.6 % of participants in these LDL-C groups, respectively. Among those with normal LDL-C, CAD incidence rose to 9.5 % in individuals with high genetic risk (P/LP variants and/or high PGS). Genetic risk was significantly associated with CAD in multivariable models ( Individuals with 'normal' LDL-C levels can have substantial CAD risk if they carry high genetic risk. These findings underscore the importance of incorporating genetic information into CAD risk assessment, even among those with traditionally normal lipid profiles. Show less

Fatty acids are important as structural components, energy sources, and signaling mediators. While studies have extensively explored genetic regulation of fatty acids in serum and other bodily fluids, their regulation within adipose tissue, a crucial regulator of cardiovascular and metabolic health, remains unclear. Here, we investigated the genetic regulation of 18 fatty acids in subcutaneous adipose tissue from 569 female twins from TwinsUK. Using twin models, the heritability of fatty acids ranged from 5% to 59%, indicating a substantial genetic regulation of fatty acid levels within adipose tissue, which was also tissue specific in many cases. Genome-wide association studies identified 10 significant loci, in SCD, ADAMTSL1, ZBTB41, SNTB1, EXOC6B, ACSL3, LINC02055, MKRN2/TSEN2, FADS1, and HAPLN across 13 fatty acids or fatty acid product-to-precursor ratios. Using adipose gene expression and methylation, which were concurrently measured in these samples, we detected five fatty acid-associated signals that colocalized with expression quantitative trait locus (eQTL) and methylation quantitative trait locus (meQTL) signals, highlighting fatty acids that are regulated by molecular processes within adipose tissue. We explored links between polygenic scores of common metabolic traits and adipose fatty acid levels and identified associations between polygenic scores of BMI, body-fat distribution, and triglycerides and several fatty acids, indicating these risk scores impact local adipose tissue content. Overall, our results identified local genetic regulation of fatty acids within adipose tissue and highlighted their links with renal and cardio-metabolic health. Show less

Current genetic testing for coronary artery disease (CAD) primarily targets monogenic variants in individuals with severe hypercholesterolemia. Whether supplementing monogenic testing with polygenic risk scores for CAD and Lp(a; lipoprotein[a]) levels [PRS A genetic probability for CAD (GenProb In the UK Biobank development cohort, PVs, polygenic risk scores for CAD and PRS GenProb Show less

Increasing physical activity is recommended for secondary stroke prevention. Remote telehealth delivery of complex stroke interventions (e.g. exercise) offers potential to meet the challenges of accessible stroke care for all survivors. However, the feasibility of remotely evaluating recommended outcomes, such as device-measured physical activity via wearable technology, is unknown. Furthermore, the effectiveness of physical activity interventions aimed at improving long-term physical activity for people with stroke is unclear. To evaluate the feasibility of remote measurement of physical activity via a research grade wearable device in the ENAbLE Pilot trial and report the effect of the physical activity intervention on device- and self-report measure physical activity. Analyses of secondary outcomes from a randomised trial (ENAbLE Pilot ACTRN12620000189921) involving adults more than 3 months to 10 years post stroke or TIA who were able to walk independently (with or without aid). Physical activity was measured using the International Physical Activity Questionnaire (IPAQ; self-report measure) and activPAL physical activity device. Feasibility outcomes included proportion of the IPAQ collected, and proportion of activPAL devices returned and days of valid data. To assess the effect of the intervention on physical activity outcomes, we used descriptive statistics and linear mixed models. Nearly all self-report (99%) and over three quarters (80%) of device-based measurements were available for analyses. No statistically significant differences in device measured physical activity were identified between participants who received the physical activity intervention and those who did not at the 3- or 6-month timepoints. Participants who undertook the physical activity intervention were more active at 12-months than non-physical activity intervention participants (activPAL measured time spent in moderate to vigorous physical activity (MVPA) 0.31 95% CI [0.07 to 0.55] hours/day, light physical activity (LPA) 0.22 [0.05 to 0.39] hours/day and daily step count 2321 [578 to 4064] steps). No statistically significant differences between groups were identified in the type of physical activity undertaken (IPAQ data), except at 12-months, when walking activity was greater in physical activity intervention participants. Remote measurement of physical activity using a wearable device after stroke and via self-report is feasible. The piloted physical activity intervention shows potential to improve physical activity. 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

Left pulmonary artery (LPA) sling is a rare congenital anomaly in which the LPA abnormally originates from the right pulmonary artery (RPA) and courses between the trachea and esophagus to reach the left pulmonary hilum. This anomaly is frequently associated with tracheobronchial and other cardiovascular anomalies and patients may manifest with varying airway and cardiovascular symptoms. Surgical repair is often required for symptomatic patients. Clinical outcomes largely depend on the extent and severity of coexisting anomalies, particularly tracheobronchial abnormalities. We report 2 autopsy cases of LPA sling, 1 pre- and 1 post-surgical repair. Comprehensive autopsy examination was crucial for confirmation of the clinical diagnoses and identification of a rare surgical complication. Show less

We report herein a phase Ib trial to determine the safety, tolerability, and antitumor activity of erdafitinib, a pan-FGFR tyrosine kinase inhibitor, with fulvestrant and palbociclib in patients with hormone receptor-positive/HER2-negative metastatic breast cancers (NCT03238196). Thirteen patients were enrolled on the escalation phase in a traditional 3 + 3 trial design to determine the maximum tolerated dose (MTD). Subsequently, 22 patients were treated at the established MTD during the expansion phase. All patients had received prior treatment with cyclin-dependent kinase-4/6 inhibitors and endocrine therapy, and 29 showed FGFR pathway alterations in their tumors. The MTD of erdafitinib was 6 mg taken orally once daily when combined with palbociclib and fulvestrant. The triple combination showed clinically manageable tolerability. Most common adverse events were neutropenia, likely attributable to palbociclib, and oral mucositis and hyperphosphatemia, attributable to erdafitinib. Three patients showed a partial response, one of them lasting more than 2.5 years, despite lacking detectable FGFR1 to FGFR4 somatic alterations. FGFR1 amplification was not associated with response to FGFR inhibition, but high FGFR1 protein expression, measured by IHC, correlated with longer progression-free survival within the FGFR1-amplified cohort. There was no correlation between FGFR1 copy number and FGFR1 protein levels in specimens from metastatic sites, potentially highlighting the need for a more recent metastatic tumor biopsy for biomarker evaluation. The trial endpoint was met establishing the MTD of erdafitinib at 6 mg. Whereas the triplet regimen may pose tolerability challenges, alterative doublets with selective FGFR1 inhibitors in patients with FGFR1-dependent tumors, possibly administered in sequence, are worthy of further investigation. Show less

Megacystis-Microcolon-Intestinal Hypoperistalsis Syndrome (MMIHS) is a rare genetic visceral myopathy, with a historically high mortality rate. Its genetic and phenotypic variability and management options remain poorly characterized. This study correlates genotype with phenotype and subsequently analyzes treatment and outcome of patients with pediatric-onset MMIHS. We retrospectively analyzed 26 MMIHS patients (median age 97 months, 62% female) with molecular diagnostics in 19 patients at a German quaternary intestinal rehabilitation center followed between 2012 and 2025. In this second-largest pediatric MMIHS cohort worldwide, genotype correlated with severity and outcomes, with Show less

Owing to the recognition of previously unknown pathogenic gene variants and reclassification of longer-known variants, gene distribution in patients with hypertrophic cardiomyopathy (HCM) is ever-changing. Conflicting data make the role of genotype in risk stratification unclear. We evaluated genotype distribution and genotype-phenotype correlations in all adult patients with HCM seen at our HCM Center of Excellence from March 31, 2010, to April 30, 2023. We also evaluated a composite outcome, including all-cause mortality, stroke, implantable cardioverter-defibrillator placement, heart failure hospitalization, left ventricular assist device implantation, heart transplantation, septal myectomy, and alcohol septal ablation, based on genotype status. All-cause mortality was separately analyzed. Of 827 patients with HCM, genotyping was completed in 754 (91.2 %). We identified 202 (27 %) genotype-positive (Gen-P), 163 (22 %) variant of unknown significance (VUS), and 389 (51 %) genotype-negative (Gen-N) patients. Mean ages were 47, 57, and 58 years, respectively. The most common gene implicated was MYBPC3 (63 %). More patients were on optimal medical treatment after following up with our HCM center. Electrocardiographic, Holter, echocardiographic, and cardiac magnetic resonance imaging characteristics differed based on genotype status. The composite outcome was worse in Gen-P than Gen-N (HR 1.84, p<0.001). Although analysis of all-cause mortality showed survival was different for Gen-P and VUS patients than for Gen-N patients, this difference was not statistically significant. MYBPC3 was the most common gene implicated. Outcomes were worse in Gen-P patients. Centers of Excellence play an important role in the optimal medical management of patients with HCM. Show less

Thirteen American Hereford cattle were reported blind with presumed onset when ~12-mo-old. All blind cattle shared a common ancestor through both the maternal and paternal pedigrees, suggesting a recessive genetic origin. Given the pedigree relationships and novel phenotype, we characterized the ophthalmo-pathologic changes associated with blindness and identified the responsible gene variant. Ophthalmologic examinations of 5 blind cattle revealed retinal degeneration. Histologically, 2 blind cattle had loss of the retinal photoreceptor layer. Whole-genome sequencing (WGS) of 7 blind cattle and 9 unaffected relatives revealed a 1-bp frameshift deletion in ceroid lipofuscinosis neuronal 3 ( Show less

Phospholipase C gamma 2 (PLCγ2) plays important roles in cell signaling downstream of various membrane receptors. PLCγ2 contains a multidomain inhibitory region critical for its regulation, while it has remained unclear how these domains contribute to PLCγ2 activity modulation. Here we determined three structures of human PLCγ2 in autoinhibited states, which reveal dynamic interactions at the autoinhibition interface, involving the conformational flexibility of the Src homology 3 (SH3) domain in the inhibitory region, and its previously unknown interaction with a carboxyl-terminal helical domain in the core region. We also determined a structure of PLCγ2 bound to the kinase domain of fibroblast growth factor receptor 1 (FGFR1), which demonstrates the recognition of FGFR1 by the nSH2 domain in the inhibitory region of PLCγ2. Our results provide structural insights into PLCγ2 regulation that will facilitate future mechanistic studies to understand the entire activation process. Show less

The number of adults living with cystic fibrosis (CF) has already increased significantly because of drastic improvements in life expectancy attributable to advances in treatment, including the development of highly effective modulator therapy. Chronic airway inflammation in CF contributes to morbidity and mortality, and aging processes like inflammaging and cell senescence influence CF pathology. Our results show that single-cell RNA sequencing data, human primary bronchial epithelial cells from non-CF and CF donors, a CF bronchial epithelial cell line, and Cftr-knockout (Cftr-/-) rats all demonstrated increased cell senescence markers in the CF bronchial epithelium. This was associated with upregulation of fibroblast growth factor receptors (FGFRs) and mitogen-activated protein kinase (MAPK) p38. Inhibition of FGFRs, specifically FGFR4 and to some extent FGFR1, attenuated cell senescence and improved mucociliary clearance, which was associated with MAPK p38 signaling. Mucociliary dysfunction could also be improved using a combination of senolytics in a CF ex vivo model. In summary, FGFR/MAPK p38 signaling contributes to cell senescence in CF airways, which is associated with impaired mucociliary clearance. Therefore, attenuation of cell senescence in the CF airways might be a future therapeutic strategy improving mucociliary dysfunction and lung disease in an aging population with CF. Show less

Short-chain fatty acids, including butyrate, have multiple metabolic benefits in individuals who are lean but not in individuals with metabolic syndrome, with the underlying mechanisms still being unclear. We aimed to investigate the role of gut microbiota in the induction of metabolic benefits of dietary butyrate. We performed antibiotic-induced microbiota depletion of the gut and fecal microbiota transplantation (FMT) in APOE*3-Leiden.CETP mice, a well-established translational model for developing human-like metabolic syndrome, and revealed that dietary butyrate reduced appetite and ameliorated high-fat diet-induced (HFD-induced) weight gain dependent on the presence of gut microbiota. FMT from butyrate-treated lean donor mice, but not butyrate-treated obese donor mice, into gut microbiota-depleted recipient mice reduced food intake, attenuated HFD-induced weight gain, and improved insulin resistance. 16S rRNA and metagenomic sequencing on cecal bacterial DNA of recipient mice implied that these effects were accompanied by the selective proliferation of Lachnospiraceae bacterium 28-4 in the gut as induced by butyrate. Collectively, our findings reveal a crucial role of gut microbiota in the beneficial metabolic effects of dietary butyrate as strongly associated with the abundance of Lachnospiraceae bacterium 28-4. Show less

Coordinated programs of gene expression drive brain development. It is unclear which transcriptional programs, in which cell-types, are affected in neuropsychiatric disorders such as schizophrenia. Here we integrate human genetics with transcriptomic data from differentiation of human embryonic stem cells into cortical excitatory neurons. We identify transcriptional programs expressed during early neurogenesis in vitro and in human foetal cortex that are down-regulated in DLG2 Show less

The palmitoyl acyltransferase (PAT) ZDHHC14 is highly expressed in the hippocampus and is the only PAT predicted to bind Type-I PDZ domain-containing proteins. However, ZDHHC14's neuronal roles are unknown. Here, we identify the PDZ domain-containing Membrane-associated Guanylate Kinase (MaGUK) PSD93 as a direct ZDHHC14 interactor and substrate. PSD93, but not other MaGUKs, localizes to the axon initial segment (AIS). Using lentiviral-mediated shRNA knockdown in rat hippocampal neurons, we find that ZDHHC14 controls palmitoylation and AIS clustering of PSD93 and also of Kv1 potassium channels, which directly bind PSD93. Neurodevelopmental expression of ZDHHC14 mirrors that of PSD93 and Kv1 channels and, consistent with ZDHHC14's importance for Kv1 channel clustering, loss of ZDHHC14 decreases outward currents and increases action potential firing in hippocampal neurons. To our knowledge, these findings identify the first neuronal roles and substrates for ZDHHC14 and reveal a previously unappreciated role for palmitoylation in control of neuronal excitability. Show less

The purpose of this study was to investigate the effect of knee extension/flexion and fatigue on muscle co-activation of the Rectus Femoris (RF) and Biceps Femoris (BF) during the eggbeater kick. Ten national level male water polo players executed eggbeater kicks at maximum effort for the duration of the test. The eggbeater kick cycle was divided into four phases (FLX1, FLX2, EXT1, EXT2). Surface electromyographs were recorded from RF and BF. EMG activity normalized to the maximum voluntary isometric contraction, muscle co-activation (CCI) and angular velocity (AV) of the right and left knee were calculated. Highest levels of RCCI and LCCI were observed during final phase of flexion (FLX2) and initial phase of extension (EXT1) (p<0.05). FLX2 and final phase of extension (EXT2) revealed the highest AV during the cycle. A decrease in CCI was observed with fatigue for FLX2 while AV was reduced for all phases. During the cycle RF and BF act as agonist/antagonist to accelerate and decelerate knee flexion/extension. The high AV and low CCI levels observed for EXT2 might increase joint instability and consequent risk of injury. This knowledge provides a better understanding of the mechanisms involved in stabilizing and controlling the knee during underwater movement. Show less

Over 1,500 gene mutations are known to cause hypertrophic cardiomyopathy (HCM). Previous studies suggest that cardiac β-myosin heavy chain (MYH7) gene mutations are commonly associated with a more severe phenotype, compared to cardiac myosin binding protein-C (MYBPC3) gene mutations with milder phenotype, incomplete penetrance and later age of onset. Compound mutations can worsen the phenotype. This study aimed to validate these comparative differences in a large cohort of individuals and families with HCM. We performed genome-phenome correlation among 80 symptomatic HCM patients, 35 asymptomatic carriers and 35 non-carriers, using an 18-gene clinical diagnostic HCM panel. A total of 125 mutations were identified in 14 genes. MYBPC3 and MYH7 mutations contributed to 50.0% and 24.4% of the HCM patients, respectively, suggesting that MYBPC3 mutations were the most frequent cause of HCM in our cohort. Double mutations were found in only nine HCM patients (7.8%) who were phenotypically indistinguishable from single-mutation carriers. Comparisons of clinical parameters of MYBPC3 and MYH7 mutants were not statistically significant, but asymptomatic carriers had high left ventricular ejection fraction and diastolic dysfunction when compared to non-carriers. The presence of double mutations increases the risk for symptomatic HCM with no change in severity, as determined in this study subset. The pathologic effects of MYBPC3 and MYH7 were found to be independent of gene mutation location. Furthermore, HCM pathology is independent of protein domain disruption in both MYBPC3 and MYH7. These data provide evidence that MYBPC3 mutations constitute the preeminent cause of HCM and that they are phenotypically indistinguishable from HCM caused by MYH7 mutations. Show less

Inconsistent effects of fish oil supplementation on plasma lipids may be influenced by genetic variation. We investigated 12 single nucleotide polymorphisms (SNPs) associated with dyslipidaemia in genome-wide association studies, in 310 participants randomised to treatment with placebo or 0.45, 0.9 and 1.8 g/day eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA) (1.51:1) in a 12-month parallel controlled trial. Effects of risk alleles were assessed as trait-specific genetic predisposition scores (GPS) and singly. GPS were positively associated with baseline concentrations of plasma total cholesterol, low-density-lipoprotein cholesterol and triglyceride (TG) and negatively with high-density-lipoprotein cholesterol. The TG-GPS was associated with 0.210 mmol/L higher TG per risk allele (P < 0.0001), but no effects of single TG SNPs were significant at baseline. After treatment with EPA and DHA, TG-GPS was associated with 0.023 mmol/L lower TG per risk allele (P = 0.72). No interactions between GPS and treatment were significant; however, FADS1 SNP rs174546 C/T interaction with treatment was a significant determinant of plasma TG concentration (P = 0.047, n = 267). Concentration differed between genotype groups after the 1.8 g/day dose (P = 0.026), decreasing by 3.5 (95 % CI -15.1 to 8.2) % in non-carriers of the risk T-allele (n = 30) and by 21.6 (95 % CI -32.1 to -11.2) % in carriers (n = 37), who showed a highly significant difference between treatments (P = 0.007). Carriers of the FADS1 rs174546 risk allele could benefit from a high intake of EPA and DHA in normalising plasma TG. Show less

Cardiac myocyte hypertrophy is the main compensatory response to chronic stress on the heart. p90 ribosomal S6 kinase (RSK) family members are effectors for extracellular signal-regulated kinases that induce myocyte growth. Although increased RSK activity has been observed in stressed myocytes, the functions of individual RSK family members have remained poorly defined, despite being potential therapeutic targets for cardiac disease. To demonstrate that type 3 RSK (RSK3) is required for cardiac myocyte hypertrophy. RSK3 contains a unique N-terminal domain that is not conserved in other RSK family members. We show that this domain mediates the regulated binding of RSK3 to the muscle A-kinase anchoring protein scaffold, defining a novel kinase anchoring event. Disruption of both RSK3 expression using RNA interference and RSK3 anchoring using a competing muscle A-kinase anchoring protein peptide inhibited the hypertrophy of cultured myocytes. In vivo, RSK3 gene deletion in the mouse attenuated the concentric myocyte hypertrophy induced by pressure overload and catecholamine infusion. Taken together, these data demonstrate that anchored RSK3 transduces signals that modulate pathologic myocyte growth. Targeting of signaling complexes that contain select kinase isoforms should provide an approach for the specific inhibition of cardiac myocyte hypertrophy and for the development of novel strategies for the prevention and treatment of heart failure. Show less

Delta-5 and delta-6 desaturases (D5D and D6D) are key enzymes in endogenous synthesis of long-chain PUFAs. In this sample of healthy subjects (n = 310), genotypes of single nucleotide polymorphisms (SNPs) rs174537, rs174561, and rs3834458 in the FADS1-FADS2 gene cluster were strongly associated with proportions of LC-PUFAs and desaturase activities estimated in plasma and erythrocytes. Minor allele carriage associated with decreased activities of D5D (FADS1) (5.84 × 10(-19) ≤ P ≤ 4.5 × 10(-18)) and D6D (FADS2) (6.05 × 10(-8) ≤ P ≤ 4.20 × 10(-7)) was accompanied by increased substrate and decreased product proportions (0.05 ≤ P ≤ 2.49 × 10(-16)). The significance of haplotype association with D5D activity (P = 2.19 × 10(-17)) was comparable to that of single SNPs, but haplotype association with D6D activity (P = 3.39 × 10(-28)) was much stronger. In a randomized controlled dietary intervention, increasing eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) intake significantly increased D5D (P = 4.0 × 10(-9)) and decreased D6D activity (P = 9.16 × 10(-6)) after doses of 0.45, 0.9, and 1.8 g/day for six months. Interaction of rs174537 genotype with treatment was a determinant of D5D activity estimated in plasma (P = 0.05). In conclusion, different sites at the FADS1-FADS2 locus appear to influence D5D and D6D activity, and rs174537 genotype interacts with dietary EPA+DHA to modulate D5D. Show less

Autism spectrum disorders are a genetically heterogeneous constellation of syndromes characterized by impairments in reciprocal social interaction. Available somatic treatments have limited efficacy. We have identified inactivating mutations in the gene BCKDK (Branched Chain Ketoacid Dehydrogenase Kinase) in consanguineous families with autism, epilepsy, and intellectual disability. The encoded protein is responsible for phosphorylation-mediated inactivation of the E1α subunit of branched-chain ketoacid dehydrogenase (BCKDH). Patients with homozygous BCKDK mutations display reductions in BCKDK messenger RNA and protein, E1α phosphorylation, and plasma branched-chain amino acids. Bckdk knockout mice show abnormal brain amino acid profiles and neurobehavioral deficits that respond to dietary supplementation. Thus, autism presenting with intellectual disability and epilepsy caused by BCKDK mutations represents a potentially treatable syndrome. Show less

Obesity is globally prevalent and highly heritable, but its underlying genetic factors remain largely elusive. To identify genetic loci for obesity susceptibility, we examined associations between body mass index and ∼ 2.8 million SNPs in up to 123,865 individuals with targeted follow up of 42 SNPs in up to 125,931 additional individuals. We confirmed 14 known obesity susceptibility loci and identified 18 new loci associated with body mass index (P < 5 × 10⁻⁸), one of which includes a copy number variant near GPRC5B. Some loci (at MC4R, POMC, SH2B1 and BDNF) map near key hypothalamic regulators of energy balance, and one of these loci is near GIPR, an incretin receptor. Furthermore, genes in other newly associated loci may provide new insights into human body weight regulation. Show less

Using the genome-wide association approach in individuals of European ancestry, we and others recently identified single-nucleotide polymorphisms (SNPs) at 19 loci as associated with blood lipids; 8 of these loci were novel. Whether these same SNPs associate with lipids in a broader range of ethnicities is unknown. We genotyped index SNPs at 19 loci in the Third United States National Health and Nutrition Examination Survey (n=7159), a population-based probability sample of the United States comprised primarily of non-Hispanic blacks, Mexican Americans, and non-Hispanic whites. We constructed ethnic-specific residual blood lipid levels after adjusting for age and gender. Ethnic-specific linear regression was used to test the association of genotype with blood lipids. To summarize the statistical evidence across 3 racial groups, we conducted a fixed-effects variance-weighted meta-analysis. After exclusions, there were 1627 non-Hispanic blacks, 1659 Mexican Americans, and 2230 non-Hispanic whites. At 5 loci (1p13 near CELSR2/PSRC1/SORT1, HMGCR, CETP, LPL, and APOA5), the index SNP was associated with low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, or triglycerides in all 3 ethnic groups. At the remaining loci, there was mixed evidence by ethnic group. In meta-analysis, we found that, at 14 of the 19 loci, SNPs exceeded a nominal P<0.05. At 5 loci including the recently discovered region on 1p13 near CELSR2/PSRC1/SORT1, the same SNP discovered in whites associates with blood lipids in non-Hispanic blacks and Mexican Americans. For the remaining loci, fine mapping and resequencing will be required to definitively evaluate the relevance of each locus in individuals of African and Hispanic ancestries. Show less