Search

Associations between human genetic variation and clinical phenotypes have become a foundation of biomedical research. Most repositories of these data seek to be disease-agnostic and therefore lack disease-focused views. The Type 2 Diabetes Knowledge Portal (T2DKP) is a public resource of genetic datasets and genomic annotations dedicated to type 2 diabetes (T2D) and related traits. Here, we seek to make the T2DKP more accessible to prospective users and more useful to existing users. First, we evaluate the T2DKP's comprehensiveness by comparing its datasets with those of other repositories. Second, we describe how researchers unfamiliar with human genetic data can begin using and correctly interpreting them via the T2DKP. Third, we describe how existing users can extend their current workflows to use the full suite of tools offered by the T2DKP. We finally discuss the lessons offered by the T2DKP toward the goal of democratizing access to complex disease genetic results.

Background & Aims Serum microRNA (miRNA) levels are known to change in non-alcoholic fatty liver disease (NAFLD) and may serve as useful biomarkers. This study aimed to profile miRNAs comprehensively at all NAFLD stages. Methods We profiled 2,083 serum miRNAs in a discovery cohort (183 cases with NAFLD representing the complete NAFLD spectrum and 10 population controls). miRNA libraries generated by HTG EdgeSeq were sequenced by Illumina NextSeq. Selected serum miRNAs were profiled in 372 additional cases with NAFLD and 15 population controls by quantitative reverse transcriptase PCR. Results Levels of 275 miRNAs differed between cases and population controls. Fewer differences were seen within individual NAFLD stages, but miR-193a-5p consistently showed increased levels in all comparisons. Relative to NAFL/non-alcoholic steatohepatitis (NASH) with mild fibrosis (stage 0/1), 3 miRNAs (miR-193a-5p, miR-378d, and miR378d) were increased in cases with NASH and clinically significant fibrosis (stages 2–4), 7 (miR193a-5p, miR-378d, miR-378e, miR-320b, miR-320c, miR-320d, and miR-320e) increased in cases with NAFLD activity score (NAS) 5–8 compared with lower NAS, and 3 (miR-193a-5p, miR-378d, and miR-378e) increased but 1 (miR-19b-3p) decreased in steatosis, activity, and fibrosis (SAF) activity score 2–4 compared with lower SAF activity. The significant findings for miR-193a-5p were replicated in the additional cohort with NAFLD. Studies in Hep G2 cells showed that following palmitic acid treatment, miR-193a-5p expression decreased significantly. Gene targets for miR-193a-5p were investigated in liver RNAseq data for a case subgroup (n = 80); liver GPX8 levels correlated positively with serum miR-193a-5p. Conclusions Serum miR-193a-5p levels correlate strongly with NAFLD activity grade and fibrosis stage. MiR-193a-5p may have a role in the hepatic response to oxidative stress and is a potential clinically tractable circulating biomarker for progressive NAFLD. Lay summary MicroRNAs (miRNAs) are small pieces of nucleic acid that may turn expression of genes on or off. These molecules can be detected in the blood circulation, and their levels in blood may change in liver disease including non-alcoholic fatty liver disease (NAFLD). To see if we could detect specific miRNA associated with advanced stages of NAFLD, we carried out miRNA sequencing in a group of 183 patients with NAFLD of varying severity together with 10 population controls. We found that a number of miRNAs showed changes, mainly increases, in serum levels but that 1 particular miRNA miR-193a-5p consistently increased. We confirmed this increase in a second group of cases with NAFLD. Measuring this miRNA in a blood sample may be a useful way to determine whether a patient has advanced NAFLD without an invasive liver biopsy., Graphical abstract, Highlights • Serum miRNA was sequenced in 183 NAFLD cases of varying severity and 10 population controls. • Plasma levels of miR-193a-5p were significantly increased in patients with advanced fibrosis, high NAS scores, or high SAF scores. • Other miRNAs including miR378d and miR378e were also significantly increased in certain comparisons. • The findings for miR-193a-5p were replicated in a cohort of 372 additional NAFLD cases.

The UK Biobank Exome Sequencing Consortium (UKB-ESC) is a private-public partnership between the UK Biobank (UKB) and eight biopharmaceutical companies that will complete the sequencing of exomes for all ~500,000 UKB participants. Here, we describe the early results from ~200,000 UKB participants and the features of this project that enabled its success. The biopharmaceutical industry has increasingly used human genetics to improve success in drug discovery. Recognizing the need for large-scale human genetics data, as well as the unique value of the data access and contribution terms of the UKB, the UKB-ESC was formed. As a result, exome data from 200,643 UKB enrollees are now available. These data include ~10 million exonic variants-a rich resource of rare coding variation that is particularly valuable for drug discovery. The UKB-ESC precompetitive collaboration has further strengthened academic and industry ties and has provided teams with an opportunity to interact with and learn from the wider research community.

The UK Biobank Exome Sequencing Consortium (UKB-ESC) is a unique private/public partnership between the UK Biobank and eight biopharma companies that will sequence the exomes of all ∼500,000 UK Biobank participants. Here we describe early results from the exome sequence data generated by this consortium for the first ∼200,000 UKB subjects and the key features of this project that enabled the UKB-ESC to come together and generate this data.Exome sequencing data from the first 200,643 UKB enrollees are now accessible to the research community. Approximately 10M variants were observed within the targeted regions, including: 8,086,176 SNPs, 370,958 indels and 1,596,984 multi-allelic variants. Of the ∼8M variants observed, 84.5% are coding variants and include 2,139,318 (25.3%) synonymous, 4,549,694 (53.8%) missense, 453,733 (5.4%) predicted loss-of-function (LOF) variants (initiation codon loss, premature stop codons, stop codon loss, splicing and frameshift variants) affecting at least one coding transcript. This open access data provides a rich resource of coding variants for rare variant genetic studies, and is particularly valuable for drug discovery efforts that utilize rare, functionally consequential variants.Over the past decade, the biopharma industry has increasingly leveraged human genetics as part of their drug discovery and development strategies. This shift was motivated by technical advances that enabled cost-effective human genetics research at scale, the emergence of electronic health records and biobanks, and a maturing understanding of how human genetics can increase the probability of successful drug development. Recognizing the need for large-scale human genetics data to drive drug discovery, and the unique value of the open data access policies and contribution terms of the UK Biobank, the UKB-ESC was formed. This precompetitive collaboration has further strengthened the ties between academia and industry and provided teams an unprecedented opportunity to interact with and learn from the wider research community.

Understanding the interaction between humans and mosquitoes is a critical area of study due to the phenomenal burdens on public health from mosquito-transmitted diseases. In this study, we conducted the first genome-wide association studies (GWAS) of self-reported mosquito bite reaction size (n = 84,724), itchiness caused by bites (n = 69,057), and perceived attractiveness to mosquitoes (n = 16,576). In total, 15 independent significant (P

Summary: Ion channels control sperm navigation within the female reproductive tract and, thus, are critical for their ability to find and fertilize an egg. The flagellar calcium channel CatSper controls sperm hyperactivated motility and is dependent on an alkaline cytoplasmic pH. The latter is accomplished by either proton transporters or, in human sperm, via the voltage-gated proton channel Hv1. To provide concerted regulation, ion channels and their regulatory proteins must be compartmentalized. Here, we describe flagellar regulatory nanodomains comprised of Hv1, CatSper, and its regulatory protein ABHD2. Super-resolution microscopy revealed that Hv1 is distributed asymmetrically within bilateral longitudinal lines and that inhibition of this channel leads to a decrease in sperm rotation along the long axis. We suggest that specific distribution of flagellar nanodomains provides a structural basis for the selective activation of CatSper and subsequent flagellar rotation. The latter, together with hyperactivated motility, enhances the fertility of sperm. : Miller et al. use super-resolution microscopy, electrophysiology, and electron microscopy to show that the sperm proton channel Hv1 forms bilateral lines positioned asymmetrically down the sperm flagellum. Hv1 inhibition leads to a decrease in sperm rotation, suggesting an important role for this channel in sperm motility. Keywords: hydrogen voltage-gated channel 1, Hv1, CatSper, STORM, super-resolution imaging, ion channels, rotation, sperm flagellum

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease worldwide. NAFLD patients have excessive liver fat (steatosis), without other liver diseases and without excessive alcohol consumption. NAFLD consists of a spectrum of conditions: benign steatosis or non-alcoholic fatty liver (NAFL), steatosis accompanied by inflammation and fibrosis or nonalcoholic steatohepatitis (NASH), and cirrhosis. Given a lack of clinical biomarkers and its asymptomatic nature, NASH is under-diagnosed. We use electronic health records from the Optum Analytics to (1) identify patients diagnosed with benign steatosis and NASH, and (2) train machine learning classifiers for NASH and healthy (non-NASH) populations to (3) predict NASH disease status on patients diagnosed with NAFL. Summarized temporal lab data for alanine aminotransferase, aspartate aminotransferase, and platelet counts, with basic demographic information and type 2 diabetes status were included in the models.

Author(s): Lishko, Polina V; Mannowetz, Nadja; Mundt, Nadine; Miller, Melissa; Kenny, Samuel; Xu, Ke; Bjoerkgren, Ida T

Steroids regulate cell proliferation, tissue development, and cell signaling via two pathways: a nuclear receptor mechanism and genome-independent signaling. Sperm activation, egg maturation, and steroid-induced anesthesia are executed via the latter pathway, the key components of which remain unknown. Here, we present characterization of the human sperm progesterone receptor that is conveyed by the orphan enzyme α/β hydrolase domain-containing protein 2 (ABHD2). We show that ABHD2 is highly expressed in spermatozoa, binds progesterone, and acts as a progesterone-dependent lipid hydrolase by depleting the endocannabinoid 2-arachidonoylglycerol (2AG) from plasma membrane. The 2AG inhibits the sperm calcium channel (CatSper), and its removal leads to calcium influx via CatSper and ensures sperm activation. This study reveals that progesterone-activated endocannabinoid depletion by ABHD2 is a general mechanism by which progesterone exerts its genome-independent action and primes sperm for fertilization.

Through a targeted recruitment 23andMe has collected DNA and patient-reported symptoms from more than 10,000 subjects reporting a physician-verified diagnosis of PD. This study evaluated the potential of self-report, web-based questionnaires to rapidly assess disease natural history and symptomology in genetically-defined PD populations. While average age-at-diagnosis was significantly lower in GBA mutation carriers compared to idiopathic PD, or iPD (idiopathic PD, defined as no GBA mutations and no LRRK2 G2019S mutation), there were no significant differences in symptoms. Conversely, LRRK2 G2019S carrier status significantly associated with reporting of milder daily symptoms of lightheadedness and several differences were observed at a false discovery rate LRRK2 G2019S carriers suggest differences in underlying pathophysiology and/or disease progression in LRRK2 carriers compared to iPD. Importantly, we confirm previous findings in PD genetic subsets where disease characteristics were ascertained through clinical exam. Overall, these data support the effective use of self-report and genetic data to rapidly analyze information from a large disease population or difficult to identify genetic subgroups.

ObjectiveMethodsThis study aimed to investigate the value of imaging-based multivariable body composition profiling by describing its association with coronary heart disease (CHD), type 2 diabetes (T2D), and metabolic health on individual and population levels. The first 6,021 participants scanned by UK Biobank were included. Body composition profiles (BCPs) were calculated, including abdominal subcutaneous adipose tissue, visceral adipose tissue (VAT), thigh muscle volume, liver fat, and muscle fat infiltration (MFI), determined using magnetic resonance imaging. Associations between BCP and metabolic status were investigated using matching procedures and multivariable statistical modeling. ResultsConclusionsMatched control analysis showed that higher VAT and MFI were associated with CHD and T2D (Pamp;lt;0.001). Higher liver fat was associated with T2D (Pamp;lt;0.001) and lower liver fat with CHD (Pamp;lt;0.05), matching on VAT. Multivariable modeling showed that lower VAT and MFI were associated with metabolic health (Pamp;lt;0.001), and liver fat was nonsignificant. Associations remained significant adjusting for sex, age, BMI, alcohol, smoking, and physical activity. Body composition profiling enabled an intuitive visualization of body composition and showed the complexity of associations between fat distribution and metabolic status, stressing the importance of a multivariable approach. Different diseases were linked to different BCPs, which could not be described by a single fat compartment alone. Funding Agencies|Pfizer Inc.

Author(s): Mannowetz, Nadja; Miller, Melissa R; Kenny, Samuel J; Mansell, Steven A; Wojcik, Michal; Zucker, Robert S; Xu, Ke; Lishko, Polina V

Background and PurposeTransient receptor potential canonical (TRPC) channels play important roles in a broad array of physiological functions and are involved in various diseases. However, due to a lack of potent subtype-specific inhibitors the exact roles of TRPC channels in physiological and pathophysiological conditions have not been elucidated.

STUDY QUESTION Does a man (patient 1) with a previously described deficiency in principle cation channel of sperm (CatSper) function have a mutation in the CatSper-epsilon (CATSPERE) and/or CatSper-zeta (CATSPERZ) gene? SUMMARY ANSWER Patient 1 has a homozygous in-frame 6-bp deletion in exon 18 (c.2393_2398delCTATGG, rs761237686) of CATSPERE. WHAT IS KNOWN ALREADY CatSper is the principal calcium channel of mammalian spermatozoa. Spermatozoa from patient 1 had a specific loss of CatSper function and were unable to fertilize at IVF. Loss of CatSper function could not be attributed to genetic abnormalities in coding regions of seven CatSper subunits. Two additional subunits (CatSper-epsilon (CATPSERE) and CatSper-zeta (CATSPERZ)) were recently identified, and are now proposed to contribute to the formation of the mature channel complex. STUDY DESIGN, SIZE, DURATION This was a basic medical research study analysing genomic data from a single patient (patient 1) for defects in CATSPERE and CATSPERZ. PARTICIPANTS/MATERIALS, SETTING, METHODS The original exome sequencing data for patient 1 were analysed for mutations in CATSPERE and CATSPERZ. Sanger sequencing was conducted to confirm the presence of a rare variant. MAIN RESULTS AND THE ROLE OF CHANCE Patient 1 is homozygous for an in-frame 6-bp deletion in exon 18 (c.2393_2398delCTATGG, rs761237686) of CATSPERE that is predicted to be highly deleterious. LIMITATIONS, REASONS FOR CAUTION The nature of the molecular deficit caused by the rs761237686 variant and whether it is exclusively responsible for the loss of CatSper function remain to be elucidated. WIDER IMPLICATIONS OF THE FINDINGS Population genetics are available for a significant number of predicted deleterious variants of CatSper subunits. The consequence of homozygous and compound heterozygous forms on sperm fertilization potential could be significant. Selective targeting of CatSper subunit expression maybe a feasible strategy for the development of novel contraceptives. STUDY FUNDING/COMPETING INTEREST(S) This study was funded by project grants from the MRC (MR/K013343/1 and MR/012492/1), Chief Scientist Office/NHS research Scotland. This work was also supported by NIH R01GM111802, Pew Biomedical Scholars Award 00028642 and Packer Wentz Endowment Will to P.V.L. C.L.R.B is the editor-in-chief of Molecular Human Reproduction, has received lecturing fees from Merck and Ferring, and is on the Scientific Advisory Panel for Ohana BioSciences. C.L.R.B was chair of the World Health Organization Expert Synthesis Group on Diagnosis of Male infertility (2012–2016).

The calcium channel of sperm (CatSper) is essential for sperm hyperactivated motility and fertility. The steroid hormone progesterone activates CatSper of human sperm via binding to the serine hydrolase ABHD2. However, steroid specificity of ABHD2 has not been evaluated. Here, we explored whether steroid hormones to which human spermatozoa are exposed in the male and female genital tract influence CatSper activation via modulation of ABHD2. The results show that testosterone, estrogen, and hydrocortisone did not alter basal CatSper currents, whereas the neurosteroid pregnenolone sulfate exerted similar effects as progesterone, likely binding to the same site. However, physiological concentrations of testosterone and hydrocortisone inhibited CatSper activation by progesterone. Additionally, testosterone antagonized the effect of pregnenolone sulfate. We have also explored whether steroid-like molecules, such as the plant triterpenoids pristimerin and lupeol, affect sperm fertility. Interestingly, both compounds competed with progesterone and pregnenolone sulfate and significantly reduced CatSper activation by either steroid. Furthermore, pristimerin and lupeol considerably diminished hyperactivation of capacitated spermatozoa. These results indicate that (i) pregnenolone sulfate together with progesterone are the main steroids that activate CatSper and (ii) pristimerin and lupeol can act as contraceptive compounds by averting sperm hyperactivation, thus preventing fertilization.

Transient receptor potential canonical 3/6/7 (TRPC3/6/7) are highly homologous receptor-operated non-selective cation channels. Despite their physiological significance, very few selective and potent agonists are available for functional examination of these channels. Using a cell-based high throughput screening approach, a lead compound with the pyrazolopyrimidine skeleton was identified as a TRPC6 agonist. Synthetic schemes for the lead and its analogues were established, and structural–activity relationship studies were carried out. A series of potent and direct agonists of TRPC3/6/ 7 channels were identified, and among them, 4m–4p have a potency order of TRPC3 > C7 > C6, with 4n being the most potent with an EC50 of

TASK-1 is a two-pore domain potassium channel that is important to modulating cell excitability, most notably in the context of neuronal pathways. In order to leverage TASK-1 for therapeutic benefit, its physiological role needs better characterization; however, designing selective inhibitors that avoid the closely related TASK-3 channel has been challenging. In this study, a series of bis-amide derived compounds were found to demonstrate improved TASK-1 selectivity over TASK-3 compared to reported inhibitors. Optimization of a marginally selective hit led to analog 35 which displays a TASK-1 IC50 = 16 nM with 62-fold selectivity over TASK-3 in an orthogonal electrophysiology assay.

Circulating immunoreactive trypsinogen (IRT), a biomarker of exocrine pancreatic disease in cystic fibrosis (CF), is elevated in most CF newborns. In those with severe CF transmembrane conductance regulator (CFTR) genotypes, IRT declines rapidly in the first years of life, reflecting progressive pancreatic damage. Consistent with this progression, a less elevated newborn IRT measure would reflect more severe pancreatic disease, including compromised islet compartments, and potentially increased risk of CF-related diabetes (CFRD). We show in two independent CF populations that a lower newborn IRT estimate is associated with higher CFRD risk among individuals with severe CFTR genotypes, and we provide evidence to support a causal relationship. Increased loge(IRT) at birth was associated with decreased CFRD risk in Canadian and Colorado samples (hazard ratio 0.30 [95% CI 0.15–0.61] and 0.39 [0.18–0.81], respectively). Using Mendelian randomization with the SLC26A9 rs7512462 genotype as an instrumental variable since it is known to be associated with IRT birth levels in the CF population, we provide evidence to support a causal contribution of exocrine pancreatic status on CFRD risk. Our findings suggest CFRD risk could be predicted in early life and that maintained ductal fluid flow in the exocrine pancreas could delay the onset of CFRD.

Background Cow's milk intake has been inconsistently associated with islet autoimmunity (IA) and type 1 diabetes (T1D) development. Genetic and environmental factors may modify the effect of cow's milk on IA and T1D risk.

The existence of pleiotropy in disorders with multi-organ involvement can suggest therapeutic targets that could ameliorate overall disease severity. Here we assessed pleiotropy of modifier genes in cystic fibrosis (CF). CF, caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, affects the lungs, liver, pancreas and intestines. However, modifier genes contribute to variable disease severity across affected organs, even in individuals with the same CFTR genotype. We sought to determine whether SLC26A9, SLC9A3 and SLC6A14, that contribute to meconium ileus in CF, are pleiotropic for other early-affecting CF co-morbidities. In the Canadian CF population, we assessed evidence for pleiotropic effects on (1) pediatric lung disease severity (n = 815), (2) age at first acquisition of Pseudomonas aeruginosa (P. aeruginosa) (n = 730), and (3) prenatal pancreatic damage measured by immunoreactive trypsinogen (n = 126). A multiple-phenotype analytic strategy assessed evidence for pleiotropy in the presence of phenotypic correlation. We required the same alleles to be associated with detrimental effects. SLC26A9 was pleiotropic for meconium ileus and pancreatic damage (p = 0.002 at rs7512462), SLC9A3 for meconium ileus and lung disease (p = 1.5 × 10(-6) at rs17563161), and SLC6A14 for meconium ileus and both lung disease and age at first P. aeruginosa infection (p = 0.0002 and p = 0.006 at rs3788766, respectively). The meconium ileus risk alleles in SLC26A9, SLC9A3 and SLC6A14 are pleiotropic, increasing risk for other early CF co-morbidities. Furthermore, co-morbidities affecting the same organ tended to associate with the same genes. The existence of pleiotropy within this single disorder suggests that complementary therapeutic strategies to augment solute transport will benefit multiple CF-associated tissues.

© 2015 American Chemical Society. The basal fungus Allomyces macrogynus (A. Macrogynus) produces motile male gametes displaying well-studied chemotaxis toward their female counterparts. This chemotaxis is driven by sirenin, a sexual pheromone released by the female gametes. The pheromone evokes a large calcium influx in the motile gametes, which could proceed through the cation channel of sperm (CatSper) complex. Herein, we report the total synthesis of sirenin in 10 steps and 8% overall yield and show that the synthetic pheromone activates the CatSper channel complex, indicated by a concentration-dependent increase in intracellular calcium in human sperm. Sirenin activation of the CatSper channel was confirmed using whole-cell patch clamp electrophysiology with human sperm. Based on this proficient synthetic route and confirmed activation of CatSper, analogues of sirenin can be designed as blockers of the CatSper channel that could provide male contraceptive agents.

We investigated whether free fatty acids (FFA) mediate the association between adiposity and insulin resistance in the Hispanic-American families of the Insulin Resistance Atherosclerosis Family Study.In 815 Hispanic individuals in the Insulin Resistance Atherosclerosis Family Study, we tested for association between the following: 1) levels of adiposity [body mass index (BMI), visceral and sc adipose tissue area (VAT and SAT)] and circulating levels of FFA; 2) levels of circulating FFA and insulin sensitivity (S(I)); and 3) levels of adiposity and S(I), additionally testing to see whether levels of FFA mediated or modified the relationship between adiposity and S(I.)After adjusting for age, sex, clinic site, and admixture, increasing levels of BMI, VAT, and SAT were weakly associated with increasing levels of circulating FFA (BMI: P = 0.024; VAT: P = 2.33 × 10(-3); SAT: P = 0.018; percent variation explained: ∼1.00%). Increasing levels of circulating FFA were associated with decreasing S(I) (P = 8.10 × 10(-11)). Increasing BMI, VAT, and SAT were also associated with decreasing S(I) (BMI: P = 4.98 × 10(-71); VAT: P = 1.48 × 10(-64); SAT: P = 4.21 × 10(-62)), but this relationship was not significantly mediated by FFA. VAT, but not BMI or SAT, interacts with levels of FFA to influence S(I) (P = 0.021).Although levels of circulating FFA are associated both with increasing adiposity and decreasing S(I), they do not appear to mediate the association between levels of adiposity and S(I) in this large cohort of Hispanic-Americans. These results may indicate that FFA contribute to insulin resistance independent of adiposity.

The S4 transmembrane segment in voltage-gated ion channels, a highly basic alpha helix, responds to changes in membrane potential and induces channel opening. Earlier work by others indicates that the S4 segment interacts with lipids in plasma membrane, but its mechanism is unclear. Working with synthetic tryptophan-labeled S4 peptides, we characterized binding of autonomous S4 to lipid membranes. The binding free energy (5.2 +/- 0.2 kcal/mol) of the peptide-lipid interaction was estimated from the apparent dissociation constants, determined from the changes in anisotropy of tryptophan fluorescence induced by addition of lipid vesicles with 30 mol% phosphatidylglycerol. The results are in good agreement with the prediction based on the Wimley-White hydrophobicity scale for interfacial (IF) binding of an alpha-helical peptide to the lipid bilayer (6.98 kcal/mol). High salt inhibited the interaction, thus indicating that the peptide/membrane interaction has both electrostatic and non-electrostatic components. Furthermore, the synthetic S4 corresponding to the Shaker potassium channel was found to spontaneously penetrate into the negatively charged lipid membrane to a depth of about 9 A. Our results revealed important biophysical parameters that influence the interaction of S4 with the membrane: they include fluidity, surface charge, and surface pressure of the membrane, and the at helicity and regular spacing of basic amino-acid residues in the S4 sequence.

Severe liver disease affects 4.5% to 10% of individuals with cystic fibrosis (CF) and is the third-leading cause of death. Liver transplantation (LT) is an accepted therapy, but the effects of liver disease and LT on pulmonary function in patients with CF are controversial. Our aim was to characterize changes in pulmonary function in LT patients with CF. Using mixed effect models, we analyzed pulmonary function before and after transplantation in 168 LT patients and 840 non-LT patients with CF who were matched by age, sex, pancreatic status, infections with US CF Foundation Patient Registry data (1989-2007). The primary outcome was the change in the forced expiratory volume in 1 second (FEV(1); percent predicted) in LT and non-LT in the 3-years periods before or after transplantation; second we compared FEV(1) changes. In the 3 years before transplantation, LT had lower initial FEV(1) values (71.5% ± 1.9%, P < 0.001) and a slower decline (+0.1% ± 0.4%/year, P < 0.001) than non-LT (79.6% ± 1.3% and -1.3% ± 0.2%/year, respectively). There was no difference in the FEV(1) decline after transplantation (-1.4% ± 0.4%/year for LT versus -2.1% ± 0.2%/year for non-LT, P = 0.14). Both the (P = 0.003) and (P = 0.001) had a slower FEV(1) decline in the period before transplantation versus after transplantation. In conclusion, pulmonary function is lower and declines more slowly in patients with CF before LT versus, but parallels the decline in non-LT after transplantation. LT is neither beneficial nor detrimental to pulmonary function in CF but returns FEV(1) decline to the same trajectory found for matched non-LT individuals with CF.

Type 1 diabetes is an autoimmune disease characterized by the destruction of the insulin producing beta cells in the pancreatic islets. Islet autoimmunity (IA) precedes and is strongly predictive of type 1 diabetes development (1); and it is likely that both genetic and environmental factors play a role in the development of IA and subsequent progression to type 1 diabetes. In the Diabetes Autoimmunity Study of the Young (DAISY), a longitudinal observational study following otherwise healthy children who are at increased risk of developing type 1 diabetes, we reported that higher omega-3 fatty acid intake was associated with a lower risk of IA [hazard ratios (HR): 0.45], and likewise, that higher percentage of omega-3 fatty acid in the erythrocyte membrane was associated with a lower risk of IA (HR: 0.63) (2). Given this association as well as the findings that children with type 1 diabetes were less likely than controls to have received fish oil in infancy (3) and had decreased percentage of docosahexaenoic acid (DHA) in erythrocyte membranes (4) as compared to controls, an obvious next question is whether omega-3 fatty acid intake or percentage of omega-3 fatty acid in erythrocyte membranes are associated with lower risk of type 1 diabetes in children who already have IA. Researchers, along with physicians and parents of children who test autoantibody positive, are likely to consider many possible ways to delay or prevent the onset of type 1 diabetes once autoimmunity has developed. This analysis would provide important information for efforts examining feasibility of interventional approaches in terms of timing and target population.

In this observational study, we compared erythrocyte membrane fatty acids in infants consuming formula supplemented with docosahexaenoic acid (DHA) and arachidonic acid (ARA) with those consuming other types of milks. In 110 infants who were participants in a cohort study of otherwise healthy children at risk for developing type 1 diabetes, erythrocytes were collected at approximately 9 months of age, and fatty acid content was measured as a percentage of total lipids. Parents reported the type of milk the infants consumed in the month of and prior to erythrocyte collection: infant formula supplemented with ARA and DHA (supplemented formula), formula with no ARA and DHA supplements (non-supplemented formula), breast milk, or non-supplemented formula plus breast milk. Membrane DHA (4.42 versus 1.79, P < 0.001) and omega-3 fatty acid (5.81 versus 3.43, P < 0.001) levels were higher in infants consuming supplemented versus non-supplemented formula. Omega-6 fatty acids were lower in infants consuming supplemented versus non-supplemented formula (26.32 versus 29.68, P = 0.023); ARA did not differ between groups. Infants given supplemented formula had higher DHA (4.42 versus 2.81, P < 0.001) and omega-3 fatty acids (5.81 versus 4.45, P = 0.008) than infants drinking breast milk. In infants whose mothers did not receive any dietary advice, use of supplemented formula is associated with higher omega-3 and lower omega-6 fatty acid status.

The incidence of obesity and overweight has reached epidemic levels in the United States and developed countries worldwide. Even more alarming is the increasing prevalence of metabolic diseases in younger children and adolescents. Infants born to obese, overweight, and diabetic mothers (even when normal weight) have increased adiposity and are at increased risk of later metabolic disease. In addition to maternal glucose, hyperlipidemia and inflammation may contribute to the childhood obesity epidemic through fetal metabolic programming, the mechanisms of which are not well understood. Pregravid obesity, when combined with normal changes in maternal metabolism, may magnify increases in inflammation and blood lipids, which can have profound effects on the developing embryo and the fetus in utero. Fetal exposure to excess blood lipids, particularly saturated fatty acids, can activate proinflammatory pathways, which could impact substrate metabolism and mitochondrial function, as well as stem cell fate, all of which affect organ development and the response to the postnatal environment. Fetal and neonatal life are characterized by tremendous plasticity and the ability to respond to environmental factors (nutrients, oxygen, hormones) by altering gene expression levels via epigenetic modifications. Given that lipids act as both transcriptional activators and signaling molecules, excess fetal lipid exposure may regulate genes involved in lipid sensing and metabolism through epigenetic mechanisms. Epigenetic regulation of gene expression is characterized by covalent modifications to DNA and chromatin that alter gene expression independent of gene sequence. Epigenetic modifications can be maintained through positive and negative feedback loops, thereby creating stable changes in the expression of metabolic genes and their main transcriptional regulators. The purpose of this article is to review current literature on maternal-fetal lipid metabolism and maternal obesity outcomes and to suggest some potential mechanisms for fetal metabolic programming in key organ systems that regulate postnatal energy balance, with an emphasis on epigenetics and the intrauterine environment.

During transit through the female reproductive tract, mammalian spermatozoa are exposed to increasing concentrations of progesterone (P4) released by the cumulus oophorus. P4 triggers massive calcium influx into human sperm through activation of the sperm-specific calcium channel CatSper. These properties of human spermatozoa are thought to be unique since CatSper is not progesterone sensitive in rodent sperm. Here, by performing patch clamp recording from spermatozoa from rhesus macaque for the first time, we report that they express P4-sensitive CatSper channel identically to human sperm and react to P4 by inducing responsiveness to zona pellucida, unlike human sperm, which respond directly to P4. We have also determined the physiologic levels of P4 capable of inducing capacitation-associated changes in macaque sperm. Progesterone (1 μM) induced up to a 3-fold increase in the percentage of sperm undergoing the zona pellucida-induced acrosome reaction with the lowest threshold as low as 10 nM of P4. Submicromolar levels of P4 induced a dose-dependent increase in curvilinear velocity and lateral head displacement, while sperm protein tyrosine phosphorylation was not altered. Macaque spermatozoa exposed to 10 μM of P4 developed fully hyperactivated motility. Similar to human sperm, on approaching cumulus mass and binding to zona pellucida, macaque spermatozoa display hyperactivation and undergo an acrosome reaction that coincides with the rise in the sperm intracellular calcium. Taken together, these data indicate that P4 accelerates the completion of capacitation and provides evidence of spermatozoa "priming" as they move into a gradient of progesterone in search for the oocyte.

© 2014 Elsevier Ltd. Motility and fertilization potential of mammalian sperm are regulated by ion homeostasis which in turn is under tight control of ion channels and transporters. Sperm intracellular pH, membrane voltage and calcium concentration ([Ca2+]i) are all important for sperm activity within the female reproductive tract. While all mammalian sperm are united in their goal to find and fertilize an egg, the molecular mechanisms they utilize for this purpose are diverse and differ between species especially on the level of ion channels. Recent direct recording from sperm cells of different species indicate the differences between rodent, non-human primate, ruminant, and human sperm on the basic levels of their ion channel regulation. In this review we summarize the current knowledge about ion channel diversity of the animal kingdom and concentrate our attention on flagellar ion channels of mammalian sperm.

In this observational study, we compared erythrocyte membrane fatty acids in infants consuming formula supplemented with docosahexaenoic acid (DHA) and arachidonic acid (ARA) with those consuming other types of milks. In 110 infants who were participants in a cohort study of otherwise healthy children at risk for developing type 1 diabetes, erythrocytes were collected at approximately 9 months of age, and fatty acid content was measured as a percent of total lipids. Parents reported the type of milk the infants consumed in the month of and prior to erythrocyte collection – infant formula supplemented with ARA and DHA (supplemented formula), formula with no ARA and DHA supplements (non-supplemented formula), breast-milk, or non-supplemented formula plus breast-milk. Membrane DHA (4.42 versus 1.79, p < 0.001) and omega-3 fatty acid (5.81 versus 3.43, p < 0.001) levels were higher in infants consuming supplemented versus non-supplemented formula. Omega-6 fatty acids were lower in infants consuming supplemented versus non-supplemented formula (26.32 versus 29.68, p = 0.023); ARA did not differ between groups. Infants given supplemented formula had higher DHA (4.42 versus 2.81, p < 0.001) and omega-3 fatty acids (5.81 versus 4.45, p = 0.008) than infants drinking breast-milk. In infants whose mothers did not receive any dietary advice, use of supplemented formula is associated with higher omega-3 and lower omega-6 fatty acid status.

The IKKbeta/NF-kappaB pathway is known to play an important role in inflammatory response and has also recently been implicated in the process of insulin resistance. We hypothesized that one or more variants in the IkappaBalpha gene (NFKBIA) or surrounding untranslated regions would be associated with insulin sensitivity (S(I)) in Hispanic-American families. We tested for association between 25 single-nucleotide polymorphisms (SNPs) in and near NFKBIA and S(I) in 981 individuals in 90 Hispanic-American families from the Insulin Resistance Atherosclerosis (IRAS) Family Study. SNP rs1951276 in the 3' flanking region of NFKBIA was associated with S(I) in the San Antonio (SA) sample after adjusting for age, gender, and admixture (uncorrected P = 1.69 x 10(-5); conservative Bonferroni correction P = 3.38 x 10(-4)). Subjects with at least one A allele for NFKBIA rs1951276 had approximately 29% lower S(I) compared to individuals homozygous for the G allele in the SA sample. Although not statistically significant, the effect was in the same direction in the San Luis Valley (SLV) sample alone (P = 0.348) and was significant in the combined SA and SLV samples (P = 5.37 x 10(-4); presence of A allele associated with approximately 20% lower S(I)). In SA, when adjusted for subcutaneous adipose tissue area (SAT, cm(2)), the association was modestly attenuated (P = 1.25 x 10(-3)), but the association remained highly significant after adjustment for visceral adipose tissue area (VAT, cm(2); P = 4.41 x 10(-6)). These results provide corroborating evidence that the NF-kappaB/IKKbeta pathway may mediate obesity-induced insulin resistance in humans.

STUDY QUESTION Are significant abnormalities of CatSper function present in IVF patients with normal sperm concentration and motility and if so what is their functional significance for fertilization success? SUMMARY ANSWER Sperm with a near absence of CatSper current failed to respond to activation of CatSper by progesterone and there was fertilization failure at IVF. WHAT IS KNOWN ALREADY In human spermatozoa, Ca2+ influx induced by progesterone is mediated by CatSper, a sperm-specific Ca2+ channel. A suboptimal Ca2+ influx is significantly associated with, and more prevalent in, men with abnormal semen parameters, and is associated with reduced fertilizing capacity. However, abnormalities in CatSper current can only be assessed directly using electrophysiology. There is only one report of a CatSper-deficient man who showed no progesterone potentiated CatSper current. A CatSper 2 genetic abnormality was present but there was no information on the [Ca2+]i response to CatSper activation by progesterone. Additionally, the semen samples had indicating significant abnormalities (oligoasthenoteratozoospermia) multiple suboptimal functional responses in the spermatozoon. As such it cannot be concluded that impaired CatSper function alone causes infertility or that CatSper blockade is a potential safe target for contraception. STUDY DESIGN, SIZE, DURATION Spermatozoa were obtained from donors and subfertile IVF patients attending a hospital assisted reproductive techniques clinic between January 2013 and December 2014. In total 134 IVF patients, 28 normozoospermic donors and 10 patients recalled due to a history of failed/low fertilization at IVF took part in the study. PARTICIPANTS/MATERIALS, SETTING, METHODS Samples were primarily screened using the Ca2+ influx induced by progesterone and, if cell number was sufficient, samples were also assessed by hyperactivation and penetration into viscous media. A defective Ca2+ response to progesterone was defined using the 99% confidence interval from the distribution of response amplitudes in normozoospermic donors. Samples showing a defective Ca2+ response were further examined in order to characterize the potential CatSper abnormalities. In men where there was a consistent and robust failure of calcium signalling, a direct assessment of CatSper function was performed using electrophysiology (patch clamping), and a blood sample was obtained for genetic analysis. MAIN RESULTS AND THE ROLE OF CHANCE A total of 101/102 (99%) IVF patients and 22/23 (96%) donors exhibited a normal Ca2+ response. The mean (±SD) normalized peak response did not differ between donors and IVF patients (2.57 ± 0.68 [n = 34 ejaculates from 23 different donors] versus 2.66 ± 0.68 [n = 102 IVF patients], P = 0.63). In recall patients, 9/10 (90%) showed a normal Ca2+ response. Three men were initially identified with a defective Ca2+ influx. However, only one (Patient 1) had a defective response in repeat semen samples. Electrophysiology experiments on sperm from Patient 1 showed a near absence of CatSper current and exon screening demonstrated no mutations in the coding regions of the CatSper complex. There was no increase in penetration of viscous media when the spermatozoa were stimulated with progesterone and importantly there was failed fertilization at IVF. LIMITATIONS, REASONS FOR CAUTION A key limitation relates to working with a specific functional parameter (Ca2+ influx induced by progesterone) in fresh sperm samples from donors and patients that have limited viability. Therefore, for practical, technical and logistical reasons, some men (∼22% of IVF patients) could not be screened. As such the incidence of significant Ca2+ abnormalities induced by progesterone may be higher than the ∼1% observed here. Additionally, we used a strict definition of a defective Ca2+ influx such that only substantial abnormalities were selected for further study. Furthermore, electrophysiology was only performed on one patient with a robust and repeatable defective calcium response. This man had negligible CatSper current but more subtle abnormalities (e.g. currents present but significantly smaller) may have been present in men with either normal or below normal Ca2+ influx. WIDER IMPLICATIONS OF THE FINDINGS These data add significantly to the understanding of the role of CatSper in human sperm function and its impact on male fertility. Remarkably, these findings provide the first direct evidence that CatSper is a suitable and specific target for human male contraception. STUDY FUNDING/COMPETING INTEREST(S) Initial funding was from NHS Tayside, Infertility Research Trust, TENOVUS, Chief Scientist Office NRS Fellowship, the Wellcome Trust, University of Abertay. The majority of the data were obtained using funding from a MRC project grant (# 4190). The authors declare that there is no conflict of interest. TRIAL REGISTRATION NUMBER Not applicable.

Objectives To test the hypothesis that multiple constituents of the apical plasma membrane residing alongside the causal cystic fibrosis (CF) transmembrane conductance regulator protein, including known CF modifiers SLC26A9 , SLC6A14 , and SLC9A3 , would be associated with prenatal exocrine pancreatic damage as measured by newborn screened (NBS) immunoreactive trypsinogen (IRT) levels. Study design NBS IRT measures and genome-wide genotype data were available on 111 subjects from Colorado, 37 subjects from Wisconsin, and 80 subjects from France. Multiple linear regression was used to determine whether any of 8 single nucleotide polymorphisms (SNPs) in SLC26A9 , SLC6A14 , and SLC9A3 were associated with IRT and whether other constituents of the apical plasma membrane contributed to IRT. Results In the Colorado sample, 3 SLC26A9 SNPs were associated with NBS IRT (min P = 1.16 × 10 −3 ; rs7512462), but no SLC6A14 or SLC9A3 SNPs were associated ( P > .05). The rs7512462 association replicated in the Wisconsin sample ( P = .03) but not in the French sample ( P = .76). Furthermore, rs7512462 was the top-ranked apical membrane constituent in the combined Colorado and Wisconsin sample. Conclusions NBS IRT is a biomarker of prenatal exocrine pancreatic disease in patients with CF, and a SNP in SLC26A9 accounts for significant IRT variability. This work suggests SLC26A9 as a potential therapeutic target to ameliorate exocrine pancreatic disease.

Flagella potassium channel of sperm (KSper) is required for successful fertilization. In mice the dominant K+ conductance is via KCNU1 or Slo3, a pH regulated K+ channel. In humans KSper is activated by Ca2+, not pH, and is inhibited by scorpion toxin. Based on these unique properties, it was suggest that Slo1 (KCNMA1) underlies the molecular identity of human KSper. Recent conflicting work indicated that human KSper maybe a Ca2+ sensitive Slo3 variant. Due to the lack of a Ca2+ sensing domain in the structure of Slo3, it seems unlikely that it would be activated by Ca2+. Therefore to address this conundrum, we characterized a KSper defective patient and present here the molecular composition of this channel complex. Infertile patients attending Ninewells Hospital, Dundee, were screened for KSper current (IK+) by using sperm patch-clamp method. One out of 13 patients showed a complete loss of IK+ and was insensitive to changes in intracellular Ca2+. MiSeq genome analysis showed no mutations in KCNMA1 but a single nucleotide polymorphism (SNP) at position 768 (W768R) in KCNU1 was present. Electrophysiological assessment of heterologously expressed mutated KCNU1 in CHO cells cloned from human spermatozoa showed no loss IK+. Further analysis of patient genome showed additional mutation in auxiliary subunits which were not present in fertile donors. Co-expression of mutated subunits in CHO cells showed a complete loss of IK+ identical to patient. Interestingly, we were unable to show Ca2+ activated IK+ in CHO cells with wild type KCNU1. This suggests human KSper may be more complex than initially thought and requires an additional Ca2+ sensitive module for channel activation.

Mammalian spermatozoa are unable to fertilize an oocyte immediately after their deposit in the female genital tract. To gain competence to fertilize, they must undergo a gradual maturation process termed capacitation that is accompanied by: 1) sperm intracellular alkalinization, evoked by proton extrusion through proton channels; 2) elevation of the intracellular [Ca2+], evoked by calcium influx through calcium ion channels, and 3) membrane hyperpolarization that is evoked by K+ efflux. Whereas the proton and calcium channels of human sperm are identified as Hv1 and CatSper, the identity of the principal potassium channel of human sperm (hKSper) was unknown. Potassium channels are indispensable for normal sperm physiology as they regulate cell membrane potential and cell motility. Recently, a pH-sensitive sperm K+ channel, encoded by the Slo3 gene was shown to be regulated by intracellular alkalinization and essential for male fertility in mice. It has been assumed, but never proven, that the K+ channel of human sperm has a similar molecular identity. Here we present full electrophysiological and pharmacological characterization of hKSper in both mature and developing human spermatozoa, and report that the molecular identity of hKSper is different from that of mouse KSper. In human sperm, the KSper current is conveyed by the big conductance, calcium-activated potassium channel (Slo1) which differs from mouse Slo3 in both its regulation and functional relationship with other sperm ion channels.

Aims/hypothesis South Asians have a two- to fivefold higher risk of developing type 2 diabetes than those of white European descent. Greater central adiposity and storage of fat in deeper or ectopic depots are potential contributing mechanisms. We collated existing and new data on the amount of subcutaneous (SAT), visceral (VAT) and liver fat in adults of South Asian and white European descent to provide a robust assessment of potential ethnic differences in these factors. Methods We performed a systematic review of the Embase and PubMed databases from inception to August 2021. Unpublished imaging data were also included. The weighted standardised mean difference (SMD) for each adiposity measure was estimated using random-effects models. The quality of the studies was assessed using the ROBINS-E tool for risk of bias and overall certainty of the evidence was assessed using the GRADE approach. The study was pre-registered with the OSF Registries (https://osf.io/w5bf9). Results We summarised imaging data on SAT, VAT and liver fat from eight published and three previously unpublished datasets, including a total of 1156 South Asian and 2891 white European men, and 697 South Asian and 2271 white European women. Despite South Asian men having a mean BMI approximately 0.5–0.7 kg/m2 lower than white European men (depending on the comparison), nine studies showed 0.34 SMD (95% CI 0.12, 0.55; I2=83%) more SAT and seven studies showed 0.56 SMD (95% CI 0.14, 0.98; I2=93%) more liver fat, but nine studies had similar VAT (−0.03 SMD; 95% CI −0.24, 0.19; I2=85%) compared with their white European counterparts. South Asian women had an approximately 0.9 kg/m2 lower BMI but 0.31 SMD (95% CI 0.14, 0.48; I2=53%) more liver fat than their white European counterparts in five studies. Subcutaneous fat levels (0.03 SMD; 95% CI −0.17, 0.23; I2=72%) and VAT levels (0.04 SMD; 95% CI −0.16, 0.24; I2=71%) did not differ significantly between ethnic groups in eight studies of women. Conclusions/interpretation South Asian men and women appear to store more ectopic fat in the liver compared with their white European counterparts with similar BMI levels. Given the emerging understanding of the importance of liver fat in diabetes pathogenesis, these findings help explain the greater diabetes risks in South Asians. Funding There was no primary direct funding for undertaking the systematic review and meta-analysis. Graphical abstract

Mammalian sperm motility and fertility potential are regulated by ion homeostasis which is controlled by a suite of ion permeable channels and transporters working in concert. While all mammalian sperm share in their goal to navigate the female reproductive tract in search of an egg, the molecular regulation of this process is extremely diverse and differs dramatically among species. Here we report that electrophysiological recordings from sperm cells of different species illustrate marked differences between rodent, human and ruminant sperm on the basis of their ion channel make-up and regulation. Furthermore, localization patterning of ion channels along the length of sperm flagella show species specific configuration. It is from these observed differences that we can now begin to explain the disparity in motility parameters among species as well as determine the effect proper spatiotemporal regulation of ion concentrations have on proper sperm motility.

Voltage sensor domain (VSD) plays a key role in the channel conductance of the voltage-gated ion channels. Out of four transmembrane segments in VSD, cationic fourth transmembrane segment (S4) is the principal voltage sensor. Various models based on X-ray crystallography and site directed mutagenesis studies have shown that S4 segment, in response to the membrane potential, undergoes a conformational rotatory motion in the hydrophobic core of the lipid bilayer. Functional studies using whole-cell/ patch clamp techniques have detailed the conductance properties of the channel. However, the exact mechanism of membrane interaction and orientation of the cationic S4 segment in the non-polar lipid bilayer is yet to be understood. Direct experimental evidence using native S4 segment and liposomes, without any other energetic cofactors, would allow a direct test of the underlying mechanism of localization of S4 in the lipid bilayer. We used various fluorescence techniques to study the interaction and penetrative depth of the native S4 peptide in the lipid bilayer. Detail information concerning autonomous partition of S4 peptides in lipids will be discussed.