Plasmodium berghei calcium-dependent protein kinase 3 is required for ookinete gliding motility and mosquito midgut invasion

Apicomplexan parasites critically depend on a unique form of gliding motility to colonize their hosts and to invade cells. Gliding requires different stage and species-specific transmembrane adhesins, which interact with an intracellular motor complex shared across parasite stages and species. How gliding is regulated by extracellular factors and intracellular signalling mechanisms is largely unknown, but current evidence suggests an important role for cytosolic calcium as a second messenger. Studying a Plasmodium berghei gene deletion mutant, we here provide evidence that a calcium-dependent protein kinase, CDPK3, has an important function in regulating motility of the ookinete in the mosquito midgut. We show that a cdpk3(–) parasite clone produces morphologically normal ookinetes, which fail to engage the midgut epithelium, due to a marked reduction in their ability to glide productively, resulting in marked reduction in malaria transmission to the mosquito. The mutant was successfully complemented with an episomally maintained cdpk3 gene, restoring mosquito transmission to wild-type level. cdpk3(–) ookinetes maintain their full genetic differentiation potential when microinjected into the mosquito haemocoel and cdpk3(–) sporozoites produced in this way are motile and infectious, suggesting an ookinete-limited essential function for CDPK3

Epiblastic Cited2 deficiency results in cardiac phenotypic heterogeneity and provides a mechanism for haploinsufficiency

AIMS: Deletion of the transcription factor Cited2 causes penetrant and phenotypically heterogenous cardiovascular and laterality defects and adrenal agenesis. Heterozygous human CITED2 mutation is associated with congenital heart disease, suggesting haploinsufficiency. Cited2 functions partly via a Nodal-->Pitx2c pathway controlling left-right patterning. In this present study we investigated the primary site of Cited2 function and mechanisms of haploinsufficiency. METHODS AND RESULTS: A Cited2 conditional allele enabled its deletion in particular cell lineages in mouse development. A lacZ reporter cassette allowed indication of deletion. Congenic Cited2 heterozygous mice were used to investigate haploinsufficiency. Embryos were examined by magnetic resonance imaging, by sectioning and by quantitative real-time polymerase chain reaction (qRT-PCR). Epiblast-specific deletion of Cited2 using Sox2Cre recapitulated penetrant and phenotypically heterogenous cardiovascular and laterality defects. Neural crest-specific deletion using Wnt1Cre affected cranial ganglia but not cardiac development. Mesodermal deletion with Mesp1Cre resulted in low penetrance of septal defect. Mesodermal deletion with T-Cre resulted in adrenal agenesis, but infrequent cardiac septal and laterality defects. beta-Galatactosidase staining and qRT-PCR demonstrated the efficiency and location of Cited2 deletion. Murine Cited2 heterozygosity is itself associated with cardiac malformation, with three of 45 embryos showing ventricular septal defect. Cited2 gene expression in E13.5 hearts was reduced 2.13-fold in Cited2(+/-) compared with wild-type (P = 2.62 x 10(-6)). The Cited2 target gene Pitx2c was reduced 1.5-fold in Cited2(+/-) (P = 0.038) hearts compared with wild-type, and reduced 4.9-fold in Cited2(-/-) hearts (P = 0.00031). Pitx2c levels were reduced two-fold (P = 0.009) in Cited2(+/-) embryos, in comparison with wild-type. Cited2 and Pitx2c expression were strongly correlated in wild-type and Cited2(+/-) hearts (Pearson rank correlation = 0.68, P = 0.0009). Cited2 expression was reduced 7474-fold in Sox2Cre deleted hearts compared with controls (P = 0.00017) and Pitx2c was reduced 3.1-fold (P = 0.013). Deletion of Cited2 with Mesp1Cre resulted in a 130-fold reduction in cardiac Cited2 expression compared with control (P = 0.0002), but Pitx2c expression was not affected. CONCLUSION: These results indicate that phenotypically heterogenous and penetrant cardiac malformations in Cited2 deficiency arise from a primary requirement in epiblast derivatives for left-right patterning, with a secondary cell-autonomous role in the mesoderm. Cardiac malformation associated with Cited2 haploinsufficiency may occur by reducing expression of key Cited2 targets such as Pitx2c

Comprehensive nationwide incidence and prevalence trends of atrial fibrillation in Finland

Peer reviewe

Socioeconomic disparities in use of rhythm control therapies in patients with incident atrial fibrillation : A Finnish nationwide cohort study

Background: In patients with atrial fibrillation (AF), socioeconomic disparities have been reported in the use of oral anticoagulant therapy and outcomes, but whether income also affects the utilization of antiarrhythmic therapies (AATs) for rhythm control is unknown. We assessed the hypothesis that AF patients with higher income are more likely to receive AATs.Methods: The nationwide retrospective registry based FinACAF cohort study covers all patients with AF from all levels of care in Finland. Patients were divided in AF diagnosis year and age-group specific income quintiles according to their highest annual income during 2004-2018. The primary outcome was the use of any AAT, including cardioversion, catheter ablation, and fulfilled antiarrhythmic drug (AAD) prescription.Results: We identified 188 175 patients (mean age 72.6 +/- 13.0 years; 49.6% female) with incident AF during 2010-2018. Patients in higher income quintiles had consistently higher use of all AAT modalities. When compared to patients in the lowest income quintile, the adjusted incidence rate ratios (95% CI) in the highest quintile were 1.53 (1.48-1.59) for any AAT, 1.71 (1.61-1.81) for AADs, 1.43 (1.37-1.49) for cardioversion, and 2.00 (1.76-2.27) for catheter ablation. No temporal change during study period was observed in the magnitude of income disparities in AAT use, except for a decrease in income-related differences in the use of AADs.Conclusion: Profound income-related disparities exist in AAT use among patients with AF in Finland, especially in the use catheter ablation.Peer reviewe

Mental health conditions and use of rhythm control therapies in patients with atrial fibrillation : a nationwide cohort study

Objectives Mental health conditions (MHCs) have been associated with undertreatment of unrelated medical conditions, but whether patients with MHCs face disparities in receiving rhythm control therapies for atrial fibrillation (AF) is currently unknown. We assessed the hypothesis that MHCs are associated with a lower use of antiarrhythmic therapies (AATs). Design A nationwide retrospective registry-based cohort study. Setting The Finnish AntiCoagulation in Atrial Fibrillation cohort included records on all patients with AF in Finland during 2007-2018 identified from nationwide registries covering all levels of care as well as drug purchases. MHCs of interest were diagnosed depression, bipolar disorder, anxiety disorder, schizophrenia and any MHC. Participants We identified 239 222 patients (mean age 72.6 +/- 13.2 years; 49.8% women) with incident AF, in whom the prevalence of any MHC was 19.9%. Outcomes Primary outcome was use of any AAT, including cardioversion, catheter ablation, and fulfilled antiarrhythmic drug (AAD) prescription. Results Lower overall use of any AAT emerged in patients with any MHC than in those without MHC (16.9% vs 22.9%, p Conclusions Among patients with AF, a clear disparity exists in AAT use between those with and without MHCs.Peer reviewe

Rural–Urban differences in Use of Rhythm Control Therapies in Patients with Incident Atrial Fibrillation: A Finnish Nationwide Cohort Study

Background: Rural–urban disparities have been reported in the access, utilization, and quality of healthcare. We aimed to assess whether use of antiarrhythmic therapies (AATs) in patients with atrial fibrillation (AF) differs between those with rural and urban residence. Methods: The registry-based FinACAF cohort covers all patients with AF from all levels of care in Finland. Patients were divided into rural and urban categories and into urbanization degree tertiles based on their municipality of residence at the time of AF diagnosis. The primary outcome was the use of any AAT, including cardioversion, catheter ablation, and fulfilled antiarrhythmic drug (AAD) prescription. Results: We identified 177,529 patients (49.9% female, mean age 73.0 (SD13.0) years) with incident AF during 2010–2018. Except for AADs, the differences in AAT use were nonsignificant when patients were stratified according to the rural–urban classification system (urban vs. rural adjusted incidence rate ratios (aIRRs) with 95% CIs for any AAT 1.01 (0.99–1.03), AADs 1.11 (1.07–1.15), cardioversion 1.01 (0.98–1.03), catheter ablation 1.05 (0.98–1.12)). However, slightly higher use of all rhythm control modalities was observed in the highest urbanization degree tertile when compared to the lowest tertile (aIRRs with 95% Cis for any AAT 1.06 (1.03–1.08), AADs 1.18 (1.14–1.23), cardioversion 1.05 (1.02–1.08), catheter ablation 1.10 (1.02–1.19)). Conclusions: This nationwide retrospective cohort study observed that urban residence is associated with higher use of AADs in patients with incident AF. Otherwise, the observed disparities were only marginal, suggesting that in the use of rhythm control therapies, no large rural–urban inequity exists in Finland

From segment to somite: segmentation to epithelialization analyzed within quantitative frameworks

One of the most visually striking patterns in the early developing embryo is somite segmentation. Somites form as repeated, periodic structures in pairs along nearly the entire caudal vertebrate axis. The morphological process involves short- and long-range signals that drive cell rearrangements and cell shaping to create discrete, epithelialized segments. Key to developing novel strategies to prevent somite birth defects that involve axial bone and skeletal muscle development is understanding how the molecular choreography is coordinated across multiple spatial scales and in a repeating temporal manner. Mathematical models have emerged as useful tools to integrate spatiotemporal data and simulate model mechanisms to provide unique insights into somite pattern formation. In this short review, we present two quantitative frameworks that address the morphogenesis from segment to somite and discuss recent data of segmentation and epithelialization

Biallelic inherited SCN8A variants, a rare cause of SCN8A‐related developmental and epileptic encephalopathy

ObjectiveMonoallelic de novo gain‐of‐function variants in the voltage‐gated sodium channel SCN8A are one of the recurrent causes of severe developmental and epileptic encephalopathy (DEE). In addition, a small number of de novo or inherited monoallelic loss‐of‐function variants have been found in patients with intellectual disability, autism spectrum disorder, or movement disorders. Inherited monoallelic variants causing either gain or loss‐of‐function are also associated with less severe conditions such as benign familial infantile seizures and isolated movement disorders. In all three categories, the affected individuals are heterozygous for a SCN8A variant in combination with a wild‐type allele. In the present study, we describe two unusual families with severely affected individuals who inherited biallelic variants of SCN8A.MethodsWe identified two families with biallelic SCN8A variants by diagnostic gene panel sequencing. Functional analysis of the variants was performed using voltage clamp recordings from transfected ND7/23 cells.ResultsWe identified three probands from two unrelated families with DEE due to biallelic SCN8A variants. Each parent of an affected individual carried a single heterozygous SCN8A variant and exhibited mild cognitive impairment without seizures. In both families, functional analysis demonstrated segregation of one allele with complete loss‐of‐function, and one allele with altered biophysical properties consistent with partial loss‐of‐function.SignificanceThese studies demonstrate that SCN8A DEE may, in rare cases, result from inheritance of two variants, both of which exhibit reduced channel activity. In these families, heterozygosity for the dominant variants results in less severe disease than biallelic inheritance of two variant alleles. The clinical consequences of variants with partial and complete loss of SCN8A function are variable and likely to be influenced by genetic background.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153117/1/epi16371_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153117/2/epi16371.pd