Junctophilin-2 (JP2) is a structural protein required for normal excitation-contraction (E-C) coupling. After cardiac stress, JP2 is cleaved by the calcium ion-dependent protease calpain, which ...disrupts the E-C coupling ultrastructural machinery and drives heart failure progression. We found that stress-induced proteolysis of JP2 liberates an N-terminal fragment (JP2NT) that translocates to the nucleus, binds to genomic DNA, and controls expression of a spectrum of genes in cardiomyocytes. Transgenic overexpression of JP2NT in mice modifies the transcriptional profile, resulting in attenuated pathological remodeling in response to cardiac stress. Conversely, loss of nuclear JP2NT function accelerates stress-induced development of hypertrophy and heart failure in mutant mice. These data reveal a self-protective mechanism in failing cardiomyocytes that transduce mechanical information (E-C uncoupling) into salutary transcriptional reprogramming in the stressed heart.
RATIONALE:The transverse tubule (T-tubule) system is the ultrastructural substrate for excitation–contraction coupling in ventricular myocytes; T-tubule disorganization and loss are linked to ...decreased contractility in end stage heart failure (HF).
OBJECTIVE:We sought to examine (1) whether pathological T-tubule remodeling occurs early in compensated hypertrophy and, if so, how it evolves during the transition from hypertrophy to HF; and (2) the role of junctophilin-2 in T-tubule remodeling.
METHODS AND RESULTS:We investigated T-tubule remodeling in relation to ventricular function during HF progression using state-of-the-art confocal imaging of T-tubules in intact hearts, using a thoracic aortic banding rat HF model. We developed a quantitative T-tubule power (TTpower) index to represent the integrity of T-tubule structure. We found that discrete local loss and global reorganization of the T-tubule system (leftward shift of TTpower histogram) started early in compensated hypertrophy in left ventricular (LV) myocytes, before LV dysfunction, as detected by echocardiography. With progression from compensated hypertrophy to early and late HF, T-tubule remodeling spread from the LV to the right ventricle, and TTpower histograms of both ventricles gradually shifted leftward. The mean LV TTpower showed a strong correlation with ejection fraction and heart weight to body weight ratio. Over the progression to HF, we observed a gradual reduction in the expression of a junctophilin protein (JP-2) implicated in the formation of T-tubule/sarcoplasmic reticulum junctions. Furthermore, we found that JP-2 knockdown by gene silencing reduced T-tubule structure integrity in cultured adult ventricular myocytes.
CONCLUSIONS:T-tubule remodeling in response to thoracic aortic banding stress begins before echocardiographically detectable LV dysfunction and progresses over the development of overt structural heart disease. LV T-tubule remodeling is closely associated with the severity of cardiac hypertrophy and predicts LV function. Thus, T-tubule remodeling may constitute a key mechanism underlying the transition from compensated hypertrophy to HF.
Tisotumab vedotin is a first-in-human antibody–drug conjugate directed against tissue factor, which is expressed across multiple solid tumour types and is associated with poor clinical outcomes. We ...aimed to establish the safety, tolerability, pharmacokinetic profile, and antitumour activity of tisotumab vedotin in a mixed population of patients with locally advanced or metastatic (or both) solid tumours known to express tissue factor.
InnovaTV 201 is a phase 1–2, open-label, dose-escalation and dose-expansion study done at 21 centres in the USA and Europe. Patients (aged ≥18 years) had relapsed, advanced, or metastatic cancer of the ovary, cervix, endometrium, bladder, prostate, oesophagus, squamous cell carcinoma of the head and neck or non-small-cell lung cancer; an Eastern Cooperative Oncology Group performance status of 0–1; and had relapsed after or were not eligible to receive the available standard of care. No specific tissue factor expression level was required for inclusion. In the dose-escalation phase, patients were treated with tisotumab vedotin between 0·3 and 2·2 mg/kg intravenously once every 3 weeks in a traditional 3 + 3 design. In the dose-expansion phase, patients were treated at the recommended phase 2 dose. The primary endpoint was the incidence of adverse events, including serious adverse events, infusion-related, treatment-related and those of grade 3 or worse, and study drug-related adverse events, analysed in all patients who received at least one dose of tisotumab vedotin (full analysis population). This trial is registered with ClinicalTrials.gov, number NCT02001623, and is closed to new participants with follow-up ongoing.
Between Dec 9, 2013, and May 18, 2015, 27 eligible patients were enrolled to the dose-escalation phase. Dose-limiting toxicities, including grade 3 type 2 diabetes mellitus, mucositis, and neutropenic fever, were seen at the 2·2 mg/kg dose; therefore, 2·0 mg/kg of tisotumab vedotin intravenously once every 3 weeks was established as the recommended phase 2 dose. Between Oct 8, 2015, and April 26, 2018, 147 eligible patients were enrolled to the dose-expansion phase. The most common (in ≥20% of patients) treatment-emergent adverse events of any grade were epistaxis (102 69% of 147 patients), fatigue (82 56%), nausea (77 52%), alopecia (64 44%), conjunctivitis (63 43%), decreased appetite (53 36%), constipation (52 35%), diarrhoea (44 30%), vomiting (42 29%), peripheral neuropathy (33 22%), dry eye (32 22%), and abdominal pain (30 20%). The most common adverse events of grade 3 or worse were fatigue (14 10% of 147 patients), anaemia (eight 5%), abdominal pain (six 4%), hypokalaemia (six 4%), conjunctivitis (five 3%), hyponatraemia (five 3%), and vomiting (five 3%). 67 (46%) of 147 patients had a treatment-emergent serious adverse event. 39 (27%) of 147 patients had a treatment-emergent serious adverse event related to the study drug. Infusion-related reactions occurred in 17 (12%) of 147 patients. Across tumour types, the confirmed proportion of patients who achieved an objective response was 15·6% (95% CI 10·2–22·5; 23 of 147 patients). There were nine deaths across all study phases (three in the dose-escalation phase and six in the dose-expansion phase); only one case of pneumonia in the dose-expansion phase was considered possibly related to study treatment.
Tisotumab vedotin has a manageable safety profile with encouraging preliminary antitumour activity across multiple tumour types in heavily pretreated patients. Continued evaluation of tisotumab vedotin is warranted in solid tumours.
Genmab A/S.
This prospective, single-site study aimed to assess the corresponding change in monocular visual acuity with induced astigmatic defocus in subjects implanted with a small-aperture intraocular lens ...(IOL).
Ten subjects with a mean age of 65.1 years were recruited. Eleven eyes of these 10 subjects were implanted (9 unilaterally, 1 bilaterally) with an IC-8 small-aperture IOL. Baseline manifest refraction and best-corrected distance visual acuity were measured with a Snellen chart (Tumbling E chart). Astigmatic defocus was induced in the same axis as the manifest sphere-cylinder refraction or at 180° for a spherical refraction. Cylinder defocus was reduced in 0.50 D steps from -2.50 D, and distance visual acuity was measured at each level of defocus.
Mean distance visual acuity was 0.08 logarithm of minimum angle of resolution (logMAR) ±0.08 (20/24) at 1.50 D of defocus, 0.18 logMAR ±0.08 (20/30) at 2.00 D of defocus, and 0.24 logMAR ±0.07 (20/35) at 2.50 D of defocus. Eight out of 10 subjects achieved 20/25 or better vision with 1.50 D of cylinder defocus, and all subjects were 20/30 or better. Ten out of 11 subjects were 20/40 or better with 2.50 D of defocus.
The IC-8 IOL shows good tolerance to astigmatic defocus with minimal effect on visual acuity. Overall, 20/25 or better distance acuity was maintained through 1.50 D cylinder defocus.
BACKGROUND—Cardiac dysfunction in failing hearts of human patients and animal models is associated with both microtubule densification and transverse-tubule (T-tubule) remodeling. Our objective was ...to investigate whether microtubule densification contributes to T-tubule remodeling and excitation–contraction coupling dysfunction in heart disease.
METHODS AND RESULTS—In a mouse model of pressure overload–induced cardiomyopathy by transaortic banding, colchicine, a microtubule depolymerizer, significantly ameliorated T-tubule remodeling and cardiac dysfunction. In cultured cardiomyocytes, microtubule depolymerization with nocodazole or colchicine profoundly attenuated T-tubule impairment, whereas microtubule polymerization/stabilization with taxol accelerated T-tubule remodeling. In situ immunofluorescence of heart tissue sections demonstrated significant disorganization of junctophilin-2 (JP2), a protein that bridges the T-tubule and sarcoplasmic reticulum membranes, in transaortic banded hearts as well as in human failing hearts, whereas colchicine injection significantly preserved the distribution of JP2 in transaortic banded hearts. In isolated mouse cardiomyocytes, prolonged culture or treatment with taxol resulted in pronounced redistribution of JP2 from T-tubules to the peripheral plasma membrane, without changing total JP2 expression. Nocodazole treatment antagonized JP2 redistribution. Moreover, overexpression of a dominant-negative mutant of kinesin 1, a microtubule motor protein responsible for anterograde trafficking of proteins, protected against JP2 redistribution and T-tubule remodeling in culture. Finally, nocodazole treatment improved Ca handling in cultured myocytes by increasing the amplitude of Ca transients and reducing the frequency of Ca sparks.
CONCLUSION—Our data identify a mechanistic link between microtubule densification and T-tubule remodeling and reveal microtubule-mediated JP2 redistribution as a novel mechanism for T-tubule disruption, loss of excitation–contraction coupling, and heart failure.
Summary
Background
The European League Against Rheumatism/American College of Rheumatology classification criteria for inflammatory myopathies are able to classify patients with skin‐predominant ...dermatomyositis (DM). However, approximately 25% of patients with skin‐predominant DM do not meet two of the three hallmark skin signs and fail to meet the criteria.
Objectives
To develop a set of skin‐focused classification criteria that will distinguish cutaneous DM from mimickers and allow a more inclusive definition of skin‐predominant disease.
Methods
An extensive literature review was done to generate items for the Delphi process. Items were grouped into categories of distribution, morphology, symptoms, antibodies, histology and contextual factors. Using REDCap™, participants rated these items in terms of appropriateness and distinguishing ability from mimickers. The relevance score ranged from 1 to 100, and the median score determined a rank‐ordered list. A prespecified median score cut‐off was decided by the steering committee and the participants. There was a pre‐Delphi and two rounds of actual Delphi.
Results
There were 50 participating dermatologists and rheumatologists from North America, South America, Europe and Asia. After a cut‐off score of 70 during the first round, 37 of the initial 54 items were retained and carried over to the next round. The cut‐off was raised to 80 during round two and a list of 25 items was generated.
Conclusions
This project is a key step in the development of prospectively validated classification criteria that will create a more inclusive population of patients with DM for clinical research.
What's already known about this topic?
Proper classification of patients with skin‐predominant dermatomyositis (DM) is indispensable in the appropriate conduct of clinical/translational research in the field.
The only validated European League Against Rheumatism/American College of Rheumatology criteria for idiopathic inflammatory myopathies are able to classify skin‐predominant DM. However, a quarter of amyopathic patients still fail the criteria and does not meet the disease classification.
What does this study add?
A list of 25 potential criteria divided into categories of distribution, morphology, symptomatology, pathology and contextual factors has been generated after several rounds of consensus exercise among experts in the field of DM.
This Delphi project is a prerequisite to the development of a validated classification criteria set for skin‐predominant DM.
Linked Comment: Fernandez. Br J Dermatol 2020; 182:274–275.
Esophageal adenocarcinoma (EAC) is a poor-prognosis cancer type with rapidly rising incidence. Understanding of the genetic events driving EAC development is limited, and there are few molecular ...biomarkers for prognostication or therapeutics. Using a cohort of 551 genomically characterized EACs with matched RNA sequencing data, we discovered 77 EAC driver genes and 21 noncoding driver elements. We identified a mean of 4.4 driver events per tumor, which were derived more commonly from mutations than copy number alterations, and compared the prevelence of these mutations to the exome-wide mutational excess calculated using non-synonymous to synonymous mutation ratios (dN/dS). We observed mutual exclusivity or co-occurrence of events within and between several dysregulated EAC pathways, a result suggestive of strong functional relationships. Indicators of poor prognosis (SMAD4 and GATA4) were verified in independent cohorts with significant predictive value. Over 50% of EACs contained sensitizing events for CDK4 and CDK6 inhibitors, which were highly correlated with clinically relevant sensitivity in a panel of EAC cell lines and organoids.
The aims of this study were to elucidate the influence of common genetic variants on childhood attention-deficit/hyperactivity disorder (ADHD) symptoms, to identify genetic variants that explain its ...high heritability, and to investigate the genetic overlap of ADHD symptom scores with ADHD diagnosis.
Within the EArly Genetics and Lifecourse Epidemiology (EAGLE) consortium, genome-wide single nucleotide polymorphisms (SNPs) and ADHD symptom scores were available for 17,666 children (<13 years of age) from nine population-based cohorts. SNP-based heritability was estimated in data from the three largest cohorts. Meta-analysis based on genome-wide association (GWA) analyses with SNPs was followed by gene-based association tests, and the overlap in results with a meta-analysis in the Psychiatric Genomics Consortium (PGC) case-control ADHD study was investigated.
SNP-based heritability ranged from 5% to 34%, indicating that variation in common genetic variants influences ADHD symptom scores. The meta-analysis did not detect genome-wide significant SNPs, but three genes, lying close to each other with SNPs in high linkage disequilibrium (LD), showed a gene-wide significant association (p values between 1.46 × 10(-6) and 2.66 × 10(-6)). One gene, WASL, is involved in neuronal development. Both SNP- and gene-based analyses indicated overlap with the PGC meta-analysis results with the genetic correlation estimated at 0.96.
The SNP-based heritability for ADHD symptom scores indicates a polygenic architecture, and genes involved in neurite outgrowth are possibly involved. Continuous and dichotomous measures of ADHD appear to assess a genetically common phenotype. A next step is to combine data from population-based and case-control cohorts in genetic association studies to increase sample size and to improve statistical power for identifying genetic variants.
Depriving microorganisms of bioavailable iron is a promising strategy for new anti-infective agents. The new, highly water-soluble, low molecular weight co-polymer DIBI was developed to selectively ...bind iron(iii) ions as a tris chelate and acts as a standalone anti-infective. Minimum inhibitory concentration (MIC) studies show DIBI is effective against representative reference strains for Gram-positive and Gram-negative bacteria
and
, and the fungus
. Compared to the small molecule iron chelators, deferiprone and deferoxamine, DIBI outclassed these by factors of 100 to 1000 for inhibition of initial growth. DIBI and a series of related co-polymers (
of 2-9 kDa) were synthesized
reversible addition-fragmentation chain transfer (RAFT) polymerization of a chelating 3-hydroxypyridin-4-one (HPO) methacrylamide monomer and
-vinylpyrrolidone (NVP). Full incorporation of the HPO monomer into the co-polymers from the reaction solution was determined by
H NMR spectroscopy and ranged from 4.6 to 25.6 mol%. UV-vis spectroscopy showed that all the HPO in DIBI binds readily to iron(iii) in a tris chelate mode to the maximum theoretical iron(iii) binding capacity of the co-polymer. Chemical characterization including single crystal X-ray diffraction analyses of the
-benzyl protected and the functional HPO monomer are discussed. By design, DIBI is highly water soluble; the highest mass fraction in water tested was 70% w/w, without the need of organic co-solvents.
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