Citations

The role of adipose tissue (AT) inflammation in AT function in humans is unclear. We tested whether AT macrophage (ATM) content, cytokine gene expression, and senescent cell burden (markers of AT inflammation) predict AT insulin resistance measured as the insulin concentration that suppresses lipolysis by 50% (IC50). We studied 86 volunteers with normal weight or obesity at baseline and a subgroup of 25 volunteers with obesity before and after weight loss. There was a strong positive relationship between IC50 and abdominal subcutaneous and femoral fat cell size (FCS). The positive, univariate relationships between IC50 and abdominal AT inflammatory markers CD68, CD14, CD206 ATM/100 adipocytes, senescent cells, IL-6, and TNF-α mRNA were not significant after adjustment for FCS. A 10% weight loss significantly reduced IC50; however, there was no reduction in adipose ATM content, senescent cells, or cytokine gene expression. Our study suggests that commonly used markers of AT inflammation are not causally linked to AT insulin resistance, whereas FCS is a strong predictor of AT insulin resistance with respect to lipolysis.

Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are transcription cofactors implicated in the contractile and profibrotic activation of fibroblasts. Fibroblast contractile function is important in alveologenesis and in lung wound healing and fibrosis. As paralogs, YAP and TAZ may have independent or redundant roles in regulating transcriptional programs and contractile function. Using IMR-90 lung fibroblasts, microarray analysis, and traction microscopy, we tested whether independent YAP or TAZ knockdown alone was sufficient to limit transcriptional activation and contraction in vitro. Our results demonstrate limited effects of knockdown of either YAP or TAZ alone, with more robust transcriptional and functional effects observed with combined knockdown, consistent with cooperation or redundancy of YAP and TAZ in transforming growth factor β1 (TGFβ1)-induced fibroblast activation and contractile force generation. The transcriptional responses to combined YAP/TAZ knockdown were focused on a relatively small subset of genes with prominent overrepresentation of genes implicated in contraction and migration. To explore potential disease relevance of our findings, we tested primary human lung fibroblasts isolated from patients with idiopathic pulmonary fibrosis and confirmed that YAP and TAZ combined knockdown reduced the expression of three cytoskeletal genes, ACTA2, CNN1, and TAGLN. We then compared the contribution of these genes, along with YAP and TAZ, to contractile function. Combined knockdown targeting YAP/TAZ was more effective than targeting any of the individual cytoskeletal genes in reducing contractile function. Together, our results demonstrate that YAP and TAZ combine to regulate a multigene program that is essential to fibroblast contractile function.

BACKGROUND: Idiopathic recurrent pericarditis (IRP) is a debilitating condition that can be recalcitrant to conventional therapy. Some patients develop steroid dependency with the attendant risks of systemic side effects and increased future recurrence. Anakinra is a recombinant human interleukin-1 receptor antagonist that reduces systemic inflammatory responses. The aim of this study was to evaluate the therapeutic role of anakinra in IRP. Methods: We retrospectively studied consenting patients with treatment refractory IRP who received anakinra, between January 2009 and November 2013. The primary end points were symptom resolution and steroid discontinuation. Results: Nine patients were followed for a median of 16.8 (IQR 1.3-24) months. Study subjects were predominantly female (7 [78%]) with a median age of 53 (IQR 38 - 58) years. All 9 patients had failed maximum tolerated doses of NSAIDs, colchicine and prednisone (median dose 20 mg [IQR 15 - 22.5]). Primary symptom was chest pain in 9 (100%), with concurrent dyspnea in 5 (56%) patients. Symptom duration prior to anakinra initiation was 24 (IQR 13 - 71) months. Indication for anakinra was steroid sparing agent in 7 (78%) and symptom control in 2 (22%) patients. The dosage was 100 mg once daily via subcutaneous injection. Baseline LVEF was 62% (IQR 59% - 67%). Echocardiographic findings include pericardial effusion in 3 (33%), pericardial thickening in 6 (67%), and constrictive physiology in 4 (44%). Pericardial enhancement on cardiac MRI was seen in 7 (78%) patients. All 9 patients (100%) had symptom improvement with complete resolution in 8 (89%) and partial resolution in 1 (11%) patient. At last follow up, all 9 (100%) patients had discontinued NSAIDs and colchicine, 5 (56%) patients discontinued and 4 (44%) had reduced prednisone dosage. All patients remained on anakinra at the end of follow up. The only reported side effect was transient injection site reaction in 4 (44%) patients. In 2 (22%) patients, attempted anakinra weaning was unsuccessful due to symptomatic flare after 6 weeks. Conclusion: Anakinra is an effective alternative agent for the management of steroid dependent IRP. It provides remarkable symptomatic amelioration, limits steroid dependency, and is associated with minimal side effects.

Background: Isovolumic contraction time (ICT) and pre-ejection period (PEP) are altered by electrical conduction delay as well as impaired contractility. An abnormal PEP has been used to select patients for cardiac resynchronization therapy (CRT), however, the predictive value of PEP for reverse remodeling (RR) has not been reported. The purpose of this study is to determine the predictive value of ICT and PEP for the RR in a prospective, single center CRT registry. Methods: Prospective registry of all heart failure patients undergoing CRT with echo pre-implant and at 3 and 6 months after implant. PEP was measured from the ECG Q wave onset to the aortic valve opening from the left ventricular outflow tract pulsed-wave Doppler tracing. The timing interval from the QRS onset to mitral valve closure was measured (mitral valve closure time). ICT was calculated as PEP-mitral valve closure time. RR was defined as >15% reduction in end-systolic volume (ESV) measured by biplane Simpson’s method. Death due to cardiac cause and heart transplantation during the 6 month period were considered as a non-response in the receiver-operating characteristics (ROC)analysis. Results: Echocardiography data was available in 83 patients at 3 and 59 patients at 6 month after CRT. RR occurred in 42 patients (51%) at 3 months and in 32 (54%) patients at 6 months By ROC analysis, the area under the curve (AUC) for predicting RR was 0.74 for ICT (p<0.001) and 0.73 for PEP (p=0.001) (See table ). ICT>123 ms yielded a very high specificity of 90–93% to predict responders at 6 month after CRT either in entire population or after excluding the patients with atrial fibrillation. Conclusion: A prolonged ICT is highly specific for predicting reverse remodeling after CRT although it is found in a limited number of patients. A strategy employing a screening ICT measurement may identify patients highly likely to achieve reverse remodeling after CRT, but can not be used to exclude patients for CRT. ROC analysis

Background : Dyssynchrony indexes derived from time to peak systolic velocity and time to peak strain have been reported to predict left ventricular reverse remodeling (RR) after cardiac resynchronization therapy (CRT). The predictive characteristics of these indices have not been validated in a variety of clinical settings. Our objective was to determine the predictive value of strain and tissue velocity derived dyssynchrony indices for RR or clinical response to CRT in a prospective single-center CRT registry. Methods : Prospective registry of all heart failure patients (pts) undergoing CRT with echo before and 3 and 6 months after CRT. Color -coded tissue Doppler imaging in 12 segments was used to calculate the standard deviation of time to peak strain (Tϵ-SD) and time to peak systolic velocity (Tv-SD). RR was defined as a decrease in end systolic volume (ESV; biplane Simpson’s method) ≥15%. Indices were assessed with receiver-operating characteristics (ROC) analysis and the area under the curve (AUC) calculated in all pts and excluding those with atrial fibrillation at implant. Results : To date, of the first 87 patients, 4 died (classified as non-responder); 83 pts had 3 and 59 pts had 6 month echocardiography follow-up. Tϵ-SD (93%) and Tv-SD (98%) were feasible in most pts. RR occurred in 42 pts (51%) at 3 month and 32 patients (54%) at 6 month follow-up. See table . Tϵ-SD was superior to Tv-SD for prediction of RR in all pts and in those without atrial fibrillation. Findings were similar regardless of ischemic (68% of patients) or non-ischemic etiology. Neither baseline Tϵ-SD nor Tv-SD correlated with the improvement in clinical response measured by the change in six minute walk distance or peak VO 2 at 3 or 6 month after CRT (data not shown). Conclusions : In this single center experience, mechanical dyssynchrony measured by strain imaging but not tissue velocity imaging was predictive of RR. Neither index predicted clinical response.

Background: Effect of CRT on the timing of regional myocardial strain is not fully described. We aimed to explore the effect of CRT on the timing of regional myocardial strain using speckle tracking echocardiography (STE). Methods: STE and tissue Doppler imaging were performed in 91 patients before and 6 month after CRT. Time to peak longitudinal strain (Tϵ) from the onset of QRS was measured in 16 segments from three apical views. Time to peak systolic tissue velocity (Tv) was also measured in 12 basal and mid segments. Reverse remodeling was defined as 10% reduction in end-systolic volume. Results: At baseline, Tϵ and Tv demonstrated specific pattern with earlier septal and delayed lateral contraction (Figure ). Tϵ in responders showed significantly earlier timing in mid inferoseptal (p=0.003) and anteroseptal segments (base, P=0.005, mid P=0.007) than in nonresponders, whereas the timing of free wall did not differ between responders and non-responders. After CRT, Tϵ in earlier segments (inferoseptal, anteroseptal and inferior wall) prolonged significantly (p<0.001), whereas other segments did not change timing. Accordingly, SD of Tϵ in 12 segments reduced after CRT (110±46 ms vs. 81±36 ms, p<0.001). Tv did not change in all segments and SD of Tv did not improve after CRT (43±16 vs. 46±16 ms, p=0.20). Conclusions: Simultaneous electrical activation of LV free wall and septum with CRT achieves mechanical synchronization by delaying the timing of earlier contracting segment rather than directly shortening the timing in lateral wall. This could be explained by the increased wall stress on the septum as it contracts simultaneously with the opposing LV free wall. Figure. Change in Regional Timing in Strain and Peak Velocity

Background: Cardiac resynchronization therapy (CRT) improves global systolic function in left ventricle. However, the impact of CRT on regional myocardial function is less clear. The aim of this study, therefore, is to evaluate regional changes in myocardial strain after CRT. Methods: Speckle tracking echocardiography (STE) was performed in 91 patients before and 6 month after CRT. Peak longitudinal strain was measured in 18 segments at base, mid and apex in three apical views. Left ventricular end-systolic volume (ESV) was measured by biplane Simpson’s method and reverse remodeling was defined as 10 % reduction in ESV at 6 month after CRT. Results: Peak strain improved in basal and mid segments of medial walls (basal inferoseptal, anteroseptal and inferior segments, p<0.05, mid inferoseptal and inferior segments: p<0.01) in entire group after CRT, with a greater degree of improvement in CRT responders than in nonresponders (Figure ). There was no significant improvement in free wall strain, with significant reduction in basal inferolateral segment after CRT (P=0.047) in entire group. Nonresponders had significant reduction in strain at the mid anterolateral segment (P=0.004) (Figure ). Strain of the apical segments also did not improve. Conclusions: CRT induces reverse remodeling by enhancing regional myocardial function in the septum, but suppresses the function in the free wall. Lack of reverse remodeling after CRT was characterized by the reduced function in lateral segments without improvement in septal function..

Significance By evaluating children with a malformed cerebral cortex, we identified an ATPase pump (ATP1A3) with an early role in brain development. The ATP1A3 pump maintains the physiological concentration of sodium and potassium ions in cells, a process critical for osmotic equilibrium and membrane potential across several developing cell populations. We employed single-cell sequencing approaches to identify key enrichments for ATP1A3 expression during human cortex development. Unravelling this early cell-type–specific pathophysiology in the developing brain offers a potential basis for the treatment of ATP1A3 -related diseases affecting prenatal and early childhood development.

AbstractObjectiveAdipose tissue (AT) senescence is associated with AT dysfunction in rodents, but little is known about human AT senescence. The study goal was to define the distribution of senescent cells in two subcutaneous depots and understand relationships with adiposity and inflammation.MethodsSixty‐three volunteers (48 females) underwent abdominal and femoral subcutaneous fat biopsies. Fat cell size, senescent cells using senescence‐associated β‐galactosidase staining per 100 nucleated cells (percentage), and mRNA expression of four cytokines were measured.ResultsThere was a larger proportion of senescent cells in femoral than abdominal subcutaneous AT (mean difference 1.6% [95% CI: 0.98%‐2.3%], p < 0.001), and the percentage of femoral AT senescent cells was greater in women than men (median 3.9% vs. 2.1%, p < 0.01). There was a positive correlation between senescence and fat cell size in abdominal (rs = 0.44, p < 0.001) and femoral (rs = 0.35, p = 0.007) AT depots. Abdominal AT tumor necrosis factor alpha (rs = 0.49, p < 0.01) and interleukin‐1β (rs = 0.44, p = 0.01) expression was positively correlated with abdominal, but not femoral, AT senescence.ConclusionsIn human subcutaneous AT, there are more senescent cells in femoral than abdominal depots; abdominal AT senescent cells are more associated with inflammatory signals than femoral AT senescent cells.

AbstractYes‐associated protein (YAP) and PDZ‐binding motif (TAZ) have emerged as important regulators of pathologic fibroblast activation in fibrotic diseases. Agonism of Gαs‐coupled G protein coupled receptors (GPCRs) provides an attractive approach to inhibit the nuclear localization and function of YAP and TAZ in fibroblasts that inhibits or reverses their pathological activation. Agonism of the dopamine D1 GPCR has proven effective in preclinical models of lung and liver fibrosis. However, the molecular mechanisms coupling GPCR agonism to YAP and TAZ inactivation in fibroblasts remain incompletely understood. Here, using human lung fibroblasts, we identify critical roles for the cAMP effectors EPAC1/2, the small GTPase RAP2c, and the serine/threonine kinase MAP4K7 as the essential elements in the downstream signaling cascade linking GPCR agonism to LATS1/2‐mediated YAP and TAZ phosphorylation and nuclear exclusion in fibroblasts. We further show that this EPAC/RAP2c/MAP4K7 signaling cascade is essential to the effects of dopamine D1 receptor agonism on reducing fibroblast proliferation, contraction, and extracellular matrix production. Targeted modulation of this cascade in fibroblasts may prove a useful strategy to regulate YAP and TAZ signaling and fibroblast activities central to tissue repair and fibrosis.