Tubulin-folding cofactor E deficiency is associated with vascular dysfunction and endoplasmatic reticulum stress of vascular smooth muscle cells

Introduction

Endothelial function assessed via flow mediated dilatation (FMD) has shown to predict risk in individuals with established cardiovascular diseases, whereas its predictive value is uncertain in the setting primary prevention.

Purpose

The aim of the current work was to discover and evaluate novel mediators of vascular dysfunction in the general population and in conditional knock-out transgenic animal models.

Methods

In order to identify novel targets that were negatively correlated with FMD and investigate their contribution in vascular function, a Genome Wide Association Study (GWAS) of 5,000 participants was performed and subsequently immune cell-, endothelial- and vascular smooth muscle cell (VSMCs)-targeted conditional knockout mouse models were generated and characterized.

Results

GWAS analysis revealed that single nucleotide polymorphisms (SNPs) in the tubulin folding cofactor E (TBCE) gene were negatively correlated with FMD and TBCE expression in the peripheral blood mononuclear cells (PBMCs). Myelomonocytic cell-targeted TBCE deficiency did not lead to any vascular dysfunction in vivo in the LysM+Cre+/−TBCEfl/fl mice. Endothelial-targeted TBCE deficiency led to an NLR family pyrin domain containing 3 (NLRP3)-dependent activation of the inflammasome in the endothelial cells of Tie2-ERT2Cre+/−TBCEfl/fl mice. Importantly, VSMC-targeted TBCE deficiency was associated with endothelial dysfunction, increased aortic wall thickness and endoplasmatic reticulum (ER) stress-mediated VSMC hyperproliferation in vivo (SMMHC-ERT2Cre+/−TBCEfl/fl), paralleled by calnexin upregulation. Administration of the blood pressure hormone angiotensin II exacerbated the vascular dysfunction and phenotype. Administration of the ER stress modulator tauroursodeoxycholic acid to the SMMHC-ERT2Cre+/−TBCEfl/fl mice reversed vascular dysfunction, paralleled by induction of Raptor/Beclin-1-dependent autophagy both in vitro and in vivo.

Conclusion

TBCE and tubulin homeostasis in the vascular musculature seem to be novel markers of vascular function and represent a new druggable target for the treatment of ER-stress-mediated vascular dysfunction.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): This work was supported by grants of the German Federal Ministry for Education and Research (BMBF01EO1003 and BMBF01EO1503), the DFG Major Research Instrumentation Programme (DFG INST 371/47-1 FUGG) as well as the Boehringer Ingelheim Foundation. PW received funds from the German Research Foundation in support of his work (DFG WE4361-4-1 and WE 4361/7-1). KS, TM and PW are PIs of the DZHK.

Predictors and prognosis of RV function in pulmonary hypertension due to heart failure with reduced ejection fraction

Background and aims

Failure of right ventricular (RV) function worsens outcome in pulmonary hypertension (PH). The adaptation of RV contractility to afterload, the RV-pulmonary artery (PA) coupling, is defined by the ratio of RV end-systolic to PA elastances (Ees/Ea). Using pressure volume loop (PV-L) technique we aimed to identify an Ees/Ea cutoff predictive for overall survival and to assess hemodynamic and morphologic conditions for adapted RV function in secondary PH due to Heart Failure with Reduced Ejection Fraction (HFREF).

Methods

This post hoc analysis is based on 112 patients of the prospective Magdeburger Resynchronization Responder Trial. All patients underwent right and left heart echocardiography, and a baseline PV-L and RV catheter measurement. A subgroup of patients (n=50) without a pre-implanted cardiac device underwent MRI at baseline.

Results

The analysis revealed that 0.68 is an optimal Ees/Ea cutoff (area under the curve: 0.697, p<0.001) predictive for overall survival (median follow up = 4.7 years, Ees/Ea ≥0.68 vs. <0.68, log-rank 8.9, p=0.003. In patients with PH (n=76, 68%) Multivariate Cox-regression demonstrated the independent prognostic value of RV-Ees/Ea in PH patients (HR 0.2, p<0.038). Patients without PH (n=36, 32%) and those with PH but RV-Ees/Ea ≥0.68 showed comparable RV-Ees/Ea ratios (0.88 vs. 0.9, p=0.39), RV size/function, and survival. In contrast, secondary PH with RV-PA coupling ratio Ees/Ea <0.68 corresponded extremely close to cut-off values that define RV dilatation/remodeling (RVEDV >160ml, RV-mass/volume-ratio <0.37 g/ml) and dysfunction (RVEF <38%, TAPSE <16mm, FAC <42%, and stroke-volume/end-systolic volume ratio <0.59) and is associated with a dramatically increased short and medium-term all-cause mortality. Independent predictors of prognostically unfavorable RV-PA coupling (Ees/Ea <0.68) in secondary PH were a preexistent dilated RV (end-diastolic volume >171ml, odds ratio, OR 0.96, p=0.021), high pulsatile load (PA compliance <2.3 ml/mmHg, OR 8.6, p=0.003), and advanced systolic left heart failure (left ventricular (LV) ejection fraction <30%, OR 1.23, p=0.028).

Conclusions

The RV-PA coupling ratio Ees/Ea predicts overall survival in PH due to HFREF and is mainly affected by pulsatile load, RV remodeling and LV dysfunction. Prognostically favorable coupling (RV-Ees/Ea ≥0.68) in PH was associated with preserved RV size/function and mid-term survival, comparable to HFREF without PH.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Boston Scientific

Failure to Show a Temperature-Dependent Vascular Stability during Hemofiltration

The effect of different blood temperatures on the vascular stability during hemofiltration was evaluated in 10 patients being in the regular chronic hemofiltration program. In contrast to recent data, no differences could be observed with regard to the heart rate, systolic blood pressure or mean arterial pressure, when the blood returned to the patient either with a temperature of 34.68°C or 36.22°C. According to these data it is therefore presently not justified to consider differences in the blood temperature as a critical determinant for the vascular stability during HF.

Influence of Membranes on Generation of β2 M and Release of Leukocyte Lysosomal Enzymes

Normal leukocyte functional capacity was investigated by evaluation of phagocytosis of opsonised yeast cells in a radiometric test system. After incubation with dialysis membranes (different cellulosic membranes, polysulfon membrane (PS), polymethylmetacrylate membrane (PMMN), the phagocytosis index, expressed as percent decrease with respect to initial values without membrane, decreased by 10%–25%. The most pronounced effect was observed with PS, cuprophane, modified cellulose and PMMA. The results are not related to differences in the viability of PMN during the test procedure; dead PMN amounted to about 4–6.5%. A significant increase in β-NAG and β-Gluc activities was released in the supernatants of the phagocytosis suspensions. This increase activity can be explained by the phagocytosis of PMN but it was not influenced by membrane contact. There was no influence of membrane contact or phagocytosis activity of PMN on the β2M concentration in the supernatant demonstrating that no in vitro generation during incubation with either membrane exists.

Estimating active layer thickness and volumetric water content from ground penetrating radar measurements in Barrow, Alaska

Ground penetrating radar (GPR) has emerged as an effective tool for estimating active layer thickness (ALT) and volumetric water content (VWC) within the active layer. In August 2013, we conducted a series of GPR and probing surveys using a 500 MHz antenna and metallic probe around Barrow, Alaska. We collected about 15 km of GPR data and 1.5 km of probing data. Here, we describe the GPR data processing workflow from raw GPR data to the estimated ALT and VWC. We include the corresponding uncertainties for each measured and estimated parameter. The estimated average GPR-derived ALT was 41 cm, with a standard deviation of 9 cm. The average probed ALT was 40 cm, with a standard deviation of 12 cm. The average GPR-derived VWC was 0.65, with a standard deviation of 0.14.

Uncertainty in the response of terrestrial carbon sink to environmental drivers undermines carbon-climate feedback predictions

Terrestrial ecosystems play a vital role in regulating the accumulation of carbon (C) in the atmosphere. Understanding the factors controlling land C uptake is critical for reducing uncertainties in projections of future climate. The relative importance of changing climate, rising atmospheric CO2, and other factors, however, remains unclear despite decades of research. Here, we use an ensemble of land models to show that models disagree on the primary driver of cumulative C uptake for 85% of vegetated land area. Disagreement is largest in model sensitivity to rising atmospheric CO2 which shows almost twice the variability in cumulative land uptake since 1901 (1 s.d. of 212.8 PgC vs. 138.5 PgC, respectively). We find that variability in CO2 and temperature sensitivity is attributable, in part, to their compensatory effects on C uptake, whereby comparable estimates of C uptake can arise by invoking different sensitivities to key environmental conditions. Conversely, divergent estimates of C uptake can occur despite being based on the same environmental sensitivities. Together, these findings imply an important limitation to the predictability of C cycling and climate under unprecedented environmental conditions. We suggest that the carbon modeling community prioritize a probabilistic multi-model approach to generate more robust C cycle projections.

Patterns of correlation of facial shape with physiological measurements are more integrated than patterns of correlation with ratings

This article exploits a method recently incorporated in the geometric morphometric toolkit that complements previous approaches to quantifying the facial features associated with specific body characteristics and trait attribution during social perception. The new method differentiates more globally encoded from more locally encoded information by a summary scaling dimension that is estimated by fitting a line to the plot of log bending energy against log variance explained, partial warp by partial warp, for some sample of varying shapes. In the present context these variances come from the regressions of shape on some exogenous cause or effect of form. We work an example involving data from male faces. Here the regression slopes are steepest, and the sums of explained variances over the uniform component, partial warp 1 and partial warp 2 are greatest, for the conventional body mass index, followed by cortisol and, lastly, perceived health. This suggests that physiological characteristics may be represented at larger scale (global patterns), whereas cues in perception are of smaller scale (local patterns). Such a polarity within psychomorphospace, the global versus the focal, now has a metric by which patterns of morphology can be modeled in both biological and psychological studies.

Hammersmith Functional Motor Scale and Motor Function Measure-20 in non ambulant SMA patients

The aim of this prospective longitudinal multi centric study was to evaluate the correlation between the Hammersmith Functional Motor Scale and the 20 item version of the Motor Function Measure in non ambulant SMA children and adults at baseline and over a 12 month period. Seventy-four non-ambulant patients performed both measures at baseline and 49 also had an assessment 12 month later. At baseline the scores ranged between 0 and 40 on the Hammersmith Motor function Scale and between 3 and 45 on the Motor Function Measure 20. The correlation between the two scales was 0.733. The 12 month changes ranged between -11 and 4 for the Hammersmith and between -11 and 7 for the Motor Function Measure 20. The correlation between changes was 0.48. Our results suggest that both scales provide useful information although they appeared to work differently at the two extremes of the spectrum of abilities. The Hammersmith Motor Function Scale appeared to be more suitable in strong non ambulant patients, while the Motor Function Measures appeared to be more sensitive to capture activities and possible changes in the very weak patients, including more items capturing axial and upper limb activities. The choice of these measures in clinical trials should therefore depend on inclusion criteria and magnitude of expected changes.