Activation of Hippo Pathway Damages Slit Diaphragm by Deprivation of Ajuba Proteins.

SIGNIFICANCE STATEMENT: Nuclear exclusion of the cotranscription factor YAP, which is a consequence of activation of the Hippo signaling pathway, leads to FSGS and podocyte apoptosis. Ajuba proteins play an important role in the glomerular filtration barrier by keeping the Hippo pathway inactive. In nephrocytes from Drosophila melanogaster , a well-established model system for podocyte research, Ajuba proteins ensure slit diaphragm (SD) formation and function. Hippo pathway activation leads to mislocalization of Ajuba proteins, decreased SD formation, rearrangement of the actin cytoskeleton, and increased SD permeability. Targeting the kinases of the Hippo pathway with specific inhibitors in the glomerulus could, therefore, be a promising strategy for therapy of FSGS. BACKGROUND: The highly conserved Hippo pathway, which regulates organ growth and cell proliferation by inhibiting transcriptional cofactors YAP/TAZ, plays a special role in podocytes, where activation of the pathway leads to apoptosis. The Ajuba family proteins (Ajuba, LIM domain-containing protein 1 (LIMD1) and Wilms tumor protein 1-interacting protein [WTIP]) can bind and inactivate large tumor suppressor kinases 1 and 2, (LATS1/2) two of the Hippo pathway key kinases. WTIP, furthermore, connects the slit diaphragm (SD), the specialized cell-cell junction between podocytes, with the actin cytoskeleton. METHODS: We used garland cell nephrocytes of Drosophila melanogaster to monitor the role of Ajuba proteins in Hippo pathway regulation and structural integrity of the SD. Microscopy and functional assays analyzed the interplay between Ajuba proteins and LATS2 regarding expression, localization, interaction, and effects on the functionality of the SD. RESULTS: In nephrocytes, the Ajuba homolog Djub recruited Warts (LATS2 homolog) to the SD. Knockdown of Djub activated the Hippo pathway. Reciprocally, Hippo activation reduced the Djub level. Both Djub knockdown and Hippo activation led to morphological changes in the SD, rearrangement of the cortical actin cytoskeleton, and increased SD permeability. Knockdown of Warts or overexpression of constitutively active Yki prevented these effects. In podocytes, Hippo pathway activation or knockdown of YAP also decreased the level of Ajuba proteins. CONCLUSIONS: Ajuba proteins regulate the structure and function of the SD in nephrocytes, connecting the SD protein complex to the actin cytoskeleton and maintaining the Hippo pathway in an inactive state. Hippo pathway activation directly influencing Djub expression suggests a self-amplifying feedback mechanism.

Prognostic implication of myocardial perfusion and contractile reserve in end-stage renal disease: A direct comparison of myocardial perfusion scintigraphy and dobutamine stress echocardiography.

BACKGROUND: We aimed to compare the prognostic value of myocardial perfusion scintigraphy (MPS) and dobutamine stress echocardiography (DSE) in patients with end-stage renal disease (ESRD) without known coronary artery disease. METHODS: Two-hundred twenty-nine ESRD patients who applied for kidney transplantation at our centre were prospectively evaluated by MPS and DSE. The primary endpoint was a composite of myocardial infarction (MI) or all-cause mortality. The secondary endpoint included MI or coronary revascularization (CR) not triggered by MPS or DSE at baseline. RESULTS: MPS detected reversible ischemia in 31 patients (13.5%) and fixed perfusion defects in 13 (5.7%) patients. DSE discovered stress-induced wall motion abnormalities (WMAs) in 28 (12.2%) and at rest in 18 (7.9%) patients. MPS and DSE results agreed in 85.6% regarding reversible defects (κ = 0.358; P < .001) and in 90.8% regarding fixed defects (κ = 0.275; P < .001). Coronary angiography detected relevant stenosis > 50% in only 15 of 38 patients (39.5%) with pathological findings in MPS and/or DSE. At a median follow-up of 8 years and 10 months, the primary endpoint occurred in 70 patients (30.6%) and the secondary endpoint in 24 patients (10.5%). The adjusted Cox hazard ratios (HRs) for the primary endpoint were 1.77 (95% CI 1.02-3.08; P = .043) for perfusion defects in MPS and 1.36 (95% CI 0.78-2.37; P = ns) for WMA in DSE. The secondary endpoint was significantly correlated with the findings of both modalities, MPS (HR 3.21; 95% CI 1.35-7.61; P = .008) and DSE (HR 2.67; 95% CI 1.15-6.20; P = .022). CONCLUSION: Perfusion defects in MPS are a stronger determinant of all-cause mortality, MI and the need for future CR compared with WMAs in DSE. Given the complementary functional information provided by MPS vs DSE, results are sometimes contradictory, which may indicate differences in the underlying pathophysiology.

Coronary artery calcium burden, carotid atherosclerotic plaque burden, and myocardial blood flow in patients with end-stage renal disease: A non-invasive imaging study combining PET/CT and 3D ultrasound.

BACKGROUND: Imaging-based measures of atherosclerosis such as coronary artery calcium score (CACS) and coronary flow reserve (CFR) as well as carotid atherosclerotic plaque burden (cPB) are predictors of cardiovascular events in the general population. The objective of this study was to correlate CACS, cPB, myocardial blood flow (MBF), and CFR in patients with end-stage renal disease (ESRD). METHODS AND RESULTS: 39 patients (mean age 53 ± 12 years) with ESRD prior to kidney transplantation were enrolled. MBF and CFR were quantified at baseline and under hyperemia by 13N-NH3-PET/CT. CACS was calculated from low-dose CT scans acquired for PET attenuation correction. cPB was assessed by 3D ultrasound. Uni- and multivariate regression analyses between these and clinical parameters were performed. Median follow-up time for clinical events was 4.4 years. Kaplan-Meier survival estimates with log-rank test were performed with regards to cardiovascular (CV) events and death of any cause. CACS and cPB were associated in ESRD patients (r = 0.48; p ≤ 0.01). While cPB correlated with age (r = 0.43; p < 0.01), CACS did not. MBFstress was negatively associated with age (r = 0.44; p < 0.01) and time on dialysis (r = 0.42; p < 0.01). There were negative correlations between MBFstress and CACS (r = - 0.62; p < 0.001) and between MBFstress and cPB (r = - 0.43; p < 0.01). Age and CACS were the strongest predictors for MBFstress. CFR was impaired (< 2.0) in eight patients who also presented with higher cPB and higher CACS compared to those with a CFR > 2.0 (p = 0.06 and p = 0.4). In contrast to MBFstress, there was neither a significant correlation between CFR and CACS (r = - 0.2; p = 0.91) nor between CFR and cPB (r = - 0.1; p = 0.55). CV event-free survival was associated with reduced CFR and MBFstress (p = 0.001 and p < 0.001) but not with cPB or CACS. CONCLUSIONS: CACS, cPB, and MBFstress are associated in patients with ESRD. Atherosclerosis is earlier detected by MBFstress than by CFR. CV event-free survival is associated with impaired CFR and MBFstress.

Facing the challenges of chronic pruritus: a report from a multi-disciplinary medical itch centre in Germany.

The complex nature and difficult-to-establish aetiology of chronic pruritus (CP) makes it challenging to provide medical care for patients with CP. This challenge can only be met with a multidisciplinary approach. The first multidisciplinary Itch Centre in Germany was established at the University of Münster in 2002 to meet the needs of this patient population. More than 2,500 outpatients and 400 inpatients are diagnosed and receive treatment each year. To ensure evidence-based medical care, an electronic system for medical documentation and patient-reported outcomes was established. Automated data transfer to a research database enables comprehensive data analysis. Our translational research has characterized peripheral and central itch mechanisms, provided novel clustering of CP patients, and identified novel target-specific therapies (e.g. neurokinin 1 receptor-antagonist). The multidisciplinary approach, combined with basic, clinical and translational research, enables comprehensive medical care of patients as well as implementation of high-quality experimental and clinical studies.

Prevalence of unknown atrial fibrillation in patients with risk factors.

AIMS: Atrial fibrillation (AF) is the most common cardiac arrhythmia. 'Silent', undiagnosed AF is often only detected with the first complication, e.g. a stroke. Detection of 'silent' AF prior to the first cerebrovascular event would be valuable to institute adequate therapy and prevent complications related to AF. We performed a simple electrocardiography (ECG) screening for silent AF in patients at risk for AF. METHODS AND RESULTS: One hundred and thirty-two adult patients (76 male; age: 64 ± 14, mean ± SD) without known AF presenting to the diabetes, hypertension, and dyslipidaemia clinics (76 outpatients in the different clinics), or to the stroke unit (56 stroke survivors) at the University Hospital Muenster were screened for unknown AF using a simple patient-operated, single-channel ECG recorder (Omron hcg-801-e, Germany). Silent AF was found in 7/132 patients (5.3%; four stroke survivors, two diabetics, one patient with hypertension, median CHADS2 score: 2 (25-75 quartiles 1-3). The prevalence of AF was higher in patients with multiple risk factors for stroke and AF: AF was found in 3% (1/32) patient with hypertension and no other risk factors for AF, but in 7% (5/71) patients with two risk factors including stroke patients (diabetes and hypertension, stroke, or stroke and hypertension), and in 11% (1/9) with stroke, hypertension, and diabetes. Standard ECG did not detect further patients with AF. CONCLUSION: A simple ECG screening could help to detect 'silent' AF prior to the first cerebrovascular events, especially in patients with multiple cardiovascular conditions. Larger studies of such a screening are warranted.

Structured Delirium Management in the Hospital.

BACKGROUND: Delirium is a common and serious complication of inpatient hospital care in older patients. The current approaches to prevention and treatment followed in German hospitals are inconsistent. The aim of this study was to test the effectiveness of a standardized multiprofessional approach to the management of delirium in inpatients. METHODS: The patients included in the study were all >65 years old, were treated for at least 3 days on an internal medicine, trauma surgery, or orthopedic ward at Münster University Hospital between January 2016 and December 2017, and showed cognitive deficits on standardized screening at the time of admission (a score of ≤=25 on the Montreal Cognitive Assessment [MoCA] test). Patients in the intervention group received standardized delirium prevention and treatment measures; those in the control group did not. The primary outcomes measured were the incidence and duration of delirium during the hospital stay; the secondary outcomes measured were cognitive deficits relevant to daily living at 12 months after discharge (MoCA and Instrumental Activities of Daily Living [I-ADL]). RESULTS: The data of 772 patients were analyzed. Both the rate and the duration of delirium were lower in the intervention group than in the control group (6.8% versus 20.5%, odds ratio 0.28, 95% confidence interval [0.18; 0.45]; 3 days [interquartile range, IQR 2-4] versus 6 days [IQR 4-8]). A year after discharge, the patients with delirium in the intervention group showed fewer cognitive deficits relevant to daily living than those in the control group (I-ADL score 2.5 [IQR 2-4] versus 1 [IQR 1-2], P = 0.02). CONCLUSION: Structured multiprofessional management reduces the incidence and duration of delirium and lowers the number of lasting cognitive deficits relevant to daily living after hospital discharge.

Case Report: Management of a Multidrug-Resistant CMV-Strain in a Renal Transplant Recipient by High-Dose CMV-Specific Immunoglobulins, Modulation in Immunosuppression, and Induction of CMV-Specific Cellular Immunity.

The management of multidrug-resistant strains of cytomegalovirus after solid organ transplantation is challenging. This case report demonstrates the successful treatment of a multidrug-resistant strain of cytomegalovirus that may represent a valuable option for problematic cases. This report illustrates the emergence of a multidrug-resistant cytomegalovirus (CMV) UL54 mutant strain in a renal transplant recipient with severe lymphopenia and thrombocytopenia. We show that the combined treatment with high-dose intravenous cytomegalovirus-specific immunoglobulins (CMV-IVIG) after the switch to a mammalian target of rapamycin (mTOR)-inhibitor and cyclosporine A was a successful treatment alternative to direct antiviral treatment with high-dose ganciclovir and foscarnet. This treatment was associated with a quantitative induction of CMV-specific CD4 and CD8 T cells that showed maturation in phenotype and functionality with decreasing viral load. Our case report illustrates that high-dose CMV-IVIG and conversion of immunosuppressive drugs to mTOR inhibitors and cyclosporine A can be a successful treatment in a situation where the use of direct antiviral drugs was considered insufficient.

Acute Kidney Injury: A Frequently Underestimated Problem in Perioperative Medicine.

BACKGROUND: Surgical patients are getting older with increasing comorbidity. Acute kidney injury (AKI) is a commonly underesti- mated perioperative complication. 2-18% of hospitalized patients and 22-57% of patients in the intensive care unit develop AKI. Even though it has a major impact on patients' outcomes, it goes unrecognized in 57-75.6% of cases. METHODS: This review is based on pertinent papers retrieved by a selective search in PubMed and the Cochrane Library employ- ing the searching terms "acute kidney injury," "biomarker," "perioperative," "renal function," and "KDIGO." RESULTS: The pathophysiology of AKI is complex. Conventional biomarkers are either not specific enough (urine output) or not sensitive enough (serum creatinine) for timely diagnosis. In view of the pathophysiology of the condition and the limited treat- ment options for it, the early detection of subclinical AKI (kidney damage without functional impairment) would seem to be a reasonable first step toward the prevention of worsening or permanent renal injury. New biomarkers of damage enable the early initiation of nephroprotective interventions. According to the "Kidney Disease: Improving Global Outcomes" (KDIGO) statement, a multimodal treatment approach is needed, including, among other things, optimization of hemodynamics and the discontinu- ation of nephrotoxic drugs. CONCLUSION: It is essential to identify patients at risk and sensitize the treating personnel to the implementation of the guidelines. The incorporation of new biomarkers into routine clinical practice is also reasonable and necessary. Future clinical trials must show in what form these biomarkers should be used (singly or collectively).

How rapid is rapid? Exemplary results of real-life rapid rule-out troponin timing in troponin-positive acute coronary syndromes without persistent ST-segment elevation in two contrasting German chest pain unit facilities.

AIM: To analyse the timing of cardiac troponin (cTn) measurements in high-risk and cTn-positive acute coronary syndromes without persistent ST-segment elevation (NSTE-ACS) in two structurally different German chest pain units (CPUs), contrasting an urban university maximum care and a rural regional primary care facility. METHODS: All patients encoded as NSTEMI during the year 2013 were retrospectively enrolled in two centres: site (I)--centre of maximum care in an urban university setting and site (II)--centre of primary care in a rural regional care setting. Data acquisition included time intervals from admission to baseline cTn and first and second cTn control as well as type and timing of invasive management. RESULTS: The median times (site I vs. site II) from admission to cTn result announcement were 26.5 vs. 33.0 min (p = 0.02) for baseline, 4 vs. 4 h (p = 0.43) for the first and 11.0 vs. 16.5 h (p = 0.03) for the second control. Timely announcement, as recommended by guidelines, was available in 86.9% at baseline, 59.4% for the first or 41.1% for the second cTn control. Rates and timing of invasive management were independent from the time point of positive cTn announcement (p = 0.51 and p = 0.68, respectively). CONCLUSIONS: German CPUs provide timely identification of cTn-positive patients in a narrow and guideline-adherent time frame using a rapid rule-out protocol. Especially, baseline and early cTn timing was comparable between the urban university maximum care and the rural regional primary care facility without relevant impact on guideline-conforming invasive management, underlining the high standard of care in those highly professional institutions.

Impact of copeptin on diagnosis, risk stratification, and intermediate-term prognosis of acute coronary syndromes.

BACKGROUND: The aim of the current study was to evaluate the diagnostic and intermediate-term prognostic impact of C-terminal portion of provasopressin (copeptin) in combination with troponin I. METHODS: In this prospective single-center study we recruited a total of 230 unselected patients with suspected recent acute coronary syndrome (ACS) presenting consecutively at our chest pain unit. Troponin I and copeptin levels were determined at presentation and after 3-6 h. Follow-up was performed after 180 days. RESULTS: Acute myocardial infarction (AMI) was the final diagnosis in 107 patients (STEMI: 24, NSTEMI: 83). The median copeptin level was significantly higher in patients having AMI than in those without (20.83 vs. 12.2 pmol/L, p < 0.0001). A troponin I level <0.04 ng/mL in combination with copeptin <14 pmol/L at admission ruled out AMI with an negative predictive value (NPV) of 97.3 %. p = 0.0045 for the added value of copeptin to troponin I. Kaplan-Meier analysis showed that copeptin levels above the diagnostic cut-off were associated with an elevated intermediate-term (180 days) mortality (p = 0.019), while no patient with copeptin values below the cut-off died. Univariate Cox regression analysis identified copeptin as strong predictor of intermediate-term mortality (HR 4.28, 95 % CI 1.58-11.6, p = 0.004). The predictive performance for prediction of 180-day mortality was significantly better if copeptin was included (C-index of 0.80) compared with that of troponin alone (C-index 0.78, p = 0.01 for the added value of copeptin to troponin I). CONCLUSIONS: Additional assessment of copeptin allows a rapid and reliable exclusion of AMI and improves diagnostic accuracy in myocardial ischemia. This study showed for the first time that copeptin provides valuable predictive information for risk stratification and intermediate-term outcome in ACS patients.