Biallelic loss-of-function variants in PLD1 cause congenital right-sided cardiac valve defects and neonatal cardiomyopathy

Congenital heart disease is the most common type of birth defect, accounting for one-third of all congenital anomalies. Using whole-exome sequencing of 2718 patients with congenital heart disease and a search in GeneMatcher, we identified 30 patients from 21 unrelated families of different ancestries with biallelic phospholipase D1 (PLD1) variants who presented predominantly with congenital cardiac valve defects. We also associated recessive PLD1 variants with isolated neonatal cardiomyopathy. Furthermore, we established that p.1668F is a founder variant among Ashkenazi Jews (allele frequency of -.2%) and describe the phenotypic spectrum of PLD1-associated congenital heart defects. PLD1 missense variants were overrepresented in regions of the protein critical for catalytic activity, and, correspondingly, we observed a strong reduction in enzymatic activity for most of the mutant proteins in an enzymatic assay. Finally, we demonstrate that PLD1 inhibition decreased endothelial-mesenchymal transition, an established pivotal early step in valvulogenesis. In conclusion, our study provides a more detailed understanding of disease mechanisms and phenotypic expression associated with PLD1 loss of function.Genetics of disease, diagnosis and treatmen

Phase Behavior of Aqueous Na-K-Mg-Ca-CI-NO3 Mixtures: Isopiestic Measurements and Thermodynamic Modeling

A comprehensive model has been established for calculating thermodynamic properties of multicomponent aqueous systems containing the Na{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, Cl{sup -}, and NO{sub 3}{sup -} ions. The thermodynamic framework is based on a previously developed model for mixed-solvent electrolyte solutions. The framework has been designed to reproduce the properties of salt solutions at temperatures ranging from the freezing point to 300 C and concentrations ranging from infinite dilution to the fused salt limit. The model has been parameterized using a combination of an extensive literature database and new isopiestic measurements for thirteen salt mixtures at 140 C. The measurements have been performed using Oak Ridge National Laboratory's (ORNL) previously designed gravimetric isopiestic apparatus, which makes it possible to detect solid phase precipitation. Water activities are reported for mixtures with a fixed ratio of salts as a function of the total apparent salt mole fraction. The isopiestic measurements reported here simultaneously reflect two fundamental properties of the system, i.e., the activity of water as a function of solution concentration and the occurrence of solid-liquid transitions. The thermodynamic model accurately reproduces the new isopiestic data as well as literature data for binary, ternary and higher-order subsystems. Because of its high accuracy in calculating vapor-liquid and solid-liquid equilibria, the model is suitable for studying deliquescence behavior of multicomponent salt systems

Prolonged cold preservation augments vascular injury independent of renal transplant immunogenicity and function

Prolonged cold preservation augments vascular injury independent of renal transplant immunogenicity and function.BackgroundWhile prolonged cold ischemia has detrimental effects on graft survival, the mechanisms remain unclear. We tested whether or not cold preservation enhances intragraft inflammatory responses and vascular injury.MethodsRat renal grafts were cold preserved in University of Wisconsin solution for 2, 4, 6, 12, 24, and 48 hours, and then transplanted into syngeneic recipients and harvested after 24 hours. Frozen sections were examined histologically and stained for vascular cellular adhesion molecule-1 (VCAM-1), platelet-endothelial cell adhesion molecule-1 (PECAM-1), major histocompatibility complex (MHC) class II, tissue factor, leukocyte function associated molecule-1 (LFA-1), very late antigen-4 (VLA-4), as well as for inflammatory cells.ResultsFunction did not differ between isografts preserved for shorter (2 to 6 hours) or longer times (12 to 24 hours). Neutrophil influx and that of LFA-1–positive cells showed similar increases in all groups. Compared with short preservation groups, the long preserved grafts had more VLA-4–positive ED-1+ monocytic infiltrates adjacent to vessels expressing VCAM-1 (P ≤ 0.001). Increased preservation duration had no effect on infiltration with recipient ED-2+ macrophages, MHC class II-positive cells, or dendritic cells. Decreased color intensity and continuity of PECAM-1 staining indicated loss of endothelial integrity in grafts preserved for longer than six hours. Intensity in VCAM-1 staining increased progressively in grafts preserved for more than six hours and was localized predominantly on the endothelium of elastic vessels. Endothelial cells, vascular smooth muscle cells, and monocytes expressed increasingly more tissue factor in grafts preserved for more than six hours, revealing enhanced intragraft procoagulant capacity. Furthermore, grafts with preservation times of more than six hours developed more severe vascular endothelial injury and worse tubular necrosis scores (P ≤ 0.001) compared with grafts with shorter preservation times.ConclusionsBecause of the prominent vascular injury, strategies for endothelial protection should be attempted in grafts with long preservation times in clinical renal transplantation

Sex-specific mTOR signaling determines sexual dimorphism in myocardial adaptation in normotensive DOCA-salt model

The deoxycorticosterone acetate (DOCA)-salt mouse model exhibits adverse cardiac remodeling in male mice and cardiac protection in female mice, even when blood pressure is normalized. We hypothesized that intact mammalian target of rapamycin (mTOR) signaling is necessary for cardiac protection in females. We first tested sex differences and intracellular signaling after mTOR targeting with rapamycin in wild-type mice. Radio-telemetric blood pressure was maintained at normal for 6 weeks. Rapamycin significantly reduced left ventricular hypertrophy, preserved ejection fraction, inhibited fibrosis, and maintained capillary structure in male mice. Decreased mTORC1 and increased mTORC2 activity were detected in rapamycin-treated male mice compared with vehicle controls. In contrast, female mice developed dilative left ventricular hypertrophy, cardiac fibrosis, and capillary loss similar to DOCA-salt females lacking the estrogen receptor {beta} (ER{beta}(-/-)) that we described earlier. Because rapamycin downregulated ER{beta} in female mice, we next studied ER{beta}(-/-) normotensive DOCA-salt females. Vehicle-treated wild-type females maintained their high constitutive mTORC1 and mTORC2 in response to DOCA-salt. In contrast to males, both mTORCs were decreased by rapamycin, in particular mTORC2 by 60%. ER{beta}(-/-) DOCA-salt females showed similar mTORC1 and mTORC2 response patterns. We suggest that ERβ-dependent regulation involves sex-specific use of mTOR signaling branches. Maintenance of both mTORC1 and mTORC2 signaling seems to be essential for adaptive cardiac remodeling in females and supports a rationale for sex-specific therapeutic strategies in left ventricular hypertrophy