Remodeling of the Fibrillation Pathway of α-Synuclein by Interaction with Antimicrobial Peptide LL-III.

Liquid-liquid phase separation (LLPS) has emerged as a key mechanism for intracellular organization, and many recent studies have provided important insights into the role of LLPS in cell biology. There is also evidence that LLPS is associated with a variety of medical conditions, including neurodegenerative disorders. Pathological aggregation of α-synuclein, which is causally linked to Parkinson's disease, can proceed via droplet condensation, which then gradually transitions to the amyloid state. We show that the antimicrobial peptide LL-III is able to interact with both monomers and condensates of α-synuclein, leading to stabilization of the droplet and preventing conversion to the fibrillar state. The anti-aggregation activity of LL-III was also confirmed in a cellular model. We anticipate that studying the interaction of antimicrobial-type peptides with liquid condensates such as α-synuclein will contribute to the understanding of disease mechanisms (that arise in such condensates) and may also open up exciting new avenues for intervention.

Use and duration of chemotherapy and its impact on survival in early-stage ovarian cancer.

OBJECTIVE: Although 5-year survival for early-stage ovarian cancer is favorable, prognosis at recurrence is poor, necessitating appropriate initial management. We examined the patterns of care and the impact of the duration of chemotherapy on survival for women with early-stage ovarian cancer. METHODS: We used the SEER-Medicare database to identify women ≥ 65 years of age with stage I ovarian cancer diagnosed from 1992 to 2009. Patients were categorized as low-risk (non-clear cell histology, stage IA or IB, grade 1 or 2) or high-risk (clear cell histology, grade 3, or stage IC). We used multivariable logistic regression models to determine predictors of chemotherapy use and duration and Cox proportional hazards models to evaluate the effect of chemotherapy use and duration on survival. RESULTS: We identified 1394 patients. Among low-risk patients, 32.9% received adjuvant chemotherapy and the use of chemotherapy increased with time. Among high-risk patients, 71.9% received adjuvant chemotherapy; 44.2% had ≤ 3 months of treatment, and 55.8% had > 3 months of treatment. Older patients were less likely to receive chemotherapy, while those with higher stage and grade were more likely to receive chemotherapy (P<0.05 for all). Among high-risk patients, the duration of chemotherapy did not impact overall (HR=0.93, 95% CI, 0.67-1.27) or cancer specific (HR=0.93; 95% CI, 0.61-1.42) survival. CONCLUSIONS: Among early-stage ovarian cancer patients, practice patterns are widely divergent. Extended duration chemotherapy does not appear to impact survival for women with high-risk disease.

Opa1 processing is dispensable in mouse development but is protective in mitochondrial cardiomyopathy.

Mitochondrial fusion and fission accompany adaptive responses to stress and altered metabolic demands. Inner membrane fusion and cristae morphogenesis depends on optic atrophy 1 (Opa1), which is expressed in different isoforms and is cleaved from a membrane-bound, long to a soluble, short form. Here, we have analyzed the physiological role of Opa1 isoforms and Opa1 processing by generating mouse lines expressing only one cleavable Opa1 isoform or a non-cleavable variant thereof. Our results show that expression of a single cleavable or non-cleavable Opa1 isoform preserves embryonic development and the health of adult mice. Opa1 processing is dispensable under metabolic and thermal stress but prolongs life span and protects against mitochondrial cardiomyopathy in OXPHOS-deficient Cox10-/- mice. Mechanistically, loss of Opa1 processing disturbs the balance between mitochondrial biogenesis and mitophagy, suppressing cardiac hypertrophic growth in Cox10-/- hearts. Our results highlight the critical regulatory role of Opa1 processing, mitochondrial dynamics, and metabolism for cardiac hypertrophy.

The impact of risk perceptions and belief in conspiracy theories on COVID-19 pandemic-related behaviours.

Throughout the COVID-19 pandemic, conspiracy theories about the virus spread rapidly, and whilst governments across the globe put in place different restrictions and guidelines to contain the pandemic, these were not universally adhered to. This research examined the association between pandemic related risk perceptions, belief in conspiracy theories, and compliance with COVID-19 public guidelines amongst a UK sample (n = 368). Participants rated their level of concern for a series of potential risks during the pandemic (to the economy, personal health, freedom, media integrity and health risk to others). Participants also rated their level of belief in different conspiracy theories and self-reported their behaviour during the first UK lockdown. Mediational analyses showed that stronger belief in conspiracy theories was associated with perceptions of lower risk to health and higher risk to the economy and freedom, which in turn were associated with lower compliance with COVID-19 related governmental guidelines. Perception of information transparency risks did not mediate the association between belief in conspiracy theories and compliant behaviours. These results highlight the key role that risk perception may play in translating belief in conspiracy theories into low compliance with governmental COVID-19 related guidelines. Our findings suggest new patterns with respect to the relationship between conspiracy theory adherence and salience of different risk perceptions amidst the pandemic, which could have implications for the development of public health messaging and communication interventions.

P-Type ATPase Apt1 of the Fungal Pathogen Cryptococcus neoformans Is a Lipid Flippase of Broad Substrate Specificity.

Lipid flippases of the P4-ATPase family are ATP-driven transporters that translocate lipids from the exoplasmic to the cytosolic leaflet of biological membranes. In the encapsulated fungal pathogen Cryptococcus neoformans, the P4-ATPase Apt1p is an important regulator of polysaccharide secretion and pathogenesis, but its biochemical characterization is lacking. Phylogenetic analysis revealed that Apt1p belongs to the subclade of P4A-ATPases characterized by the common requirement for a ß-subunit. Using heterologous expression in S. cerevisiae, we demonstrate that Apt1p forms a heterodimeric complex with the C. neoformans Cdc50 protein. This association is required for both localization and activity of the transporter complex. Lipid flippase activity of the heterodimeric complex was assessed by complementation tests and uptake assays employing fluorescent lipids and revealed a broad substrate specificity, including several phospholipids, the alkylphospholipid miltefosine, and the glycolipids glucosyl- and galactosylceramide. Our results suggest that transbilayer lipid transport in C. neoformans is finely regulated to promote fungal virulence, which reinforces the potential of Apt1p as a target for antifungal drug development.

The identification of orally bioavailable thrombopoietin agonists.

Recently, we disclosed a series of potent pyrimidine benzamide-based thrombopoietin receptor agonists. Unfortunately, the structural features required for the desired activity conferred physicochemical properties that were not favorable for the development of an oral agent. The physical properties of the series were improved by replacing the aminopyrimidinyl group with a piperidine-4-carboxylic acid moiety. The resulting compounds possessed favorable in vivo pharmacokinetic properties, including good bioavailability.

Use of Impella Recover 2.5 left ventricular assist device in patients with cardiogenic shock or undergoing high-risk percutaneous coronary intervention procedures: experience of a high-volume center.

AIM: Percutaneous coronary interventions are increasingly applied to high-risk patients. The availability of hemodynamic support devices offers a promising option to prevent and treat low-output syndrome in these patients. The aim of this study was to evaluate the feasibility, safety and efficacy of the Impella Recover'' LP 2.5 left ventricular assist device in patients with cardiogenic shock or undergoing high-risk percutaneous coronary interventions. METHODS: Eleven patients presenting cardiogenic shock (N=6) or scheduled for high-risk percutaneous revascularization (N=5) were evaluated. The Impella pump was successfully implanted in all patients, except one. When implanted, the device was correctly positioned in the left ventricle and remained in a stable position. RESULTS: Bleedings occurred in 7 patients (5 of them presented cardiogenic shock), while renal failure and severe thrombocytopenia were observed in 4 and 1 patients respectively, all with cardiogenic shock. During high-risk procedures, the Impella pump succeeded in obtaining hemodynamic stability, while in only two patients with cardiogenic shock the device determined a significant improvement of hemodynamic variables. All elective patients and two patients with cardiogenic shock were discharged from the hospital and were still alive at 30-day follow-up. CONCLUSION: These data, although preliminary due to the limited sample size, demonstrated the feasibility, safety and efficacy of the Impella Recover LP 2.5 during high-risk percutaneous procedures, even though the benefits of prophylactic deployment of such a system have to be further investigated. The use of Impella Recover LP 2.5 in patients with cardiogenic shock is feasible and safe, however it maybe insufficient in reversing an advanced cardiogenic shock which, probably, has to be treated with more powerful left ventricular assist devices.

Venture wire control catheter in percutaneous treatment of complex coronary bifurcation. A case report.

We present a case report of a man with atherosclerotic involvement of a left main trifurcation treated by the Venture wire control catheter. The patient was submitted to primary percutaneous transluminal coronary angioplasty (PTCA) in a primary center for acute occlusion of the left anterior descending artery, then he was transferred to our tertiary center to perform left main trifurcation revascularization that was unsuccessful by traditional approach. In our high volume center (operator >600 PTCA/year) as well, the attempts at crossing the lesion with a number of different guidewires failed because of the extreme angulation of the circumflex artery. At last, a successful attempt was reached using the Venture wire control, a low profile catheter with a tip that can be deflected up to 90 degrees . Once the lesion was crossed and wiring of other branches obtained, crush stenting of the left anterior descending artery and intermediate ramus and T-stent of the circumflex artery were performed with an optimal angiographic result.

Potent, selective spiropyrrolidine pyrimidinetrione inhibitors of MMP-13.

Explorations in the pyrimidinetrione series of MMP-13 inhibitors led to the discovery of a series of spiro-fused compounds that are potent and selective inhibitors of MMP-13. While other spiro-fused motifs are hydrolytically unstable, presumably due to electronic destabilization of the pyrimidinetrione ring, the spiropyrrolidine series does not share this liability. Greater than 100-fold selectivity versus other MMP family members was achieved by incorporation of an extended aryl-heteroaryl P1'group. When dosed as the sodium salt, these compounds displayed excellent oral absorption and pharmacokinetic properties. Despite the selectivity, a representative of this series produced fibroplasia in a 14 day rat study.

Resynchronization of mitral valve annular segments reduces functional mitral regurgitation in cardiac resynchronization therapy.

AIM: Cardiac resynchronization therapy (CRT) reduces the severity of functional mitral regurgitation (FMR) in patients with heart failure and left bundle branch block. Our hypothesis was that the induction of a more synchronous mitral valve anulus contraction can be a mechanism of FMR reduction in CRT patients. METHODS: An echo tissue Doppler imaging (TDI) examination was performed at baseline and 6 months after biventricular pacing system implant in 30 patients (4 females and 26 males, 74.1+/-6.1 years) with dilatative or ischemic chronic heart failure, NYHA class = or >III, ejection fraction (EF) = or <35% and QRS = or >140 ms. EF, Myocardial Performance Index (MPI), left end-diastolic and systolic volumes (LVEDV, LVESV), mitral regurgitation jet area/left atrial area (JA/LAA), effective regurgitant orifice area (EROA), mitral anulus contraction (MAC) were evaluated. Using TDI, at the 6 left ventricle (LV) basal segments the time to the peak myocardial sustained systolic velocity (Ts) and the standard deviation (SD) of TS were evaluated. RESULTS: At 6 months follow-up NYHA class, EF, MPI were significantly improved, LV volumes were reduced. FMR degree, evaluated both as JA/LAA and EROA, was significantly reduced. This effect was associated with the 6 basal segments resynchronization and with a more effective annular contraction. CONCLUSIONS: Our data show that CRT by resynchronizing left ventricular basal segments produces a more effective mitral valve annulus contraction and contributes to FMR improvement. Further studies need to evaluate if this could be taken into account as new therapeutic perspective of functional mitral valve regurgitation.

The glycophorin A transmembrane sequence within integrin αvß3 creates a non-signaling integrin with low basal affinity that is strongly adhesive under force.

Integrin heterodimeric cell adhesion and signaling receptors bind ligands of the extracellular matrix and relay signals bidirectionally across cell membranes. Thereby, integrins adopt multiple conformational and functional states that control ligand binding affinity and linkage to cytosolic/cytoskeletal proteins. Here, we designed an integrin chimera encompassing the strongly dimerizing transmembrane domain (TMD) of glycophorin A (GpA) in the context of the otherwise unaltered integrin αvß3. We hypothesized that this chimera should have a low basal affinity to soluble ligand but should be force-activatable. By cellular expression of this chimera, we found a decreased integrin affinity to a soluble peptide ligand and inhibited intracellular signaling. However, under external forces applied by an atomic force microscope or by a spinning disc device causing shear forces, the mutant caused stronger cell adhesion than the wild-type integrin. Our results demonstrate that the signaling- and migration-incapable integrin αvß3-TMD mutant TMD-GpA shows the characteristics of a primed integrin state, which is of low basal affinity in the absence of forces, but may form strong bonds in the presence of forces. Thus, TMD-GpA may mimic a force-activatable signaling intermediate.

The feasibility of a structured cognitive training protocol to address progressive cognitive decline in individuals with vascular dementia.

PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, better known as CADASIL, is a rare, genetic form of early-onset vascular dementia. The purpose of this study was to use a modified version of Attention Process Training--II (APT-II; Sohlberg, Johnson, Paule, Raskin, & Mateer, 2001) with an individual with early-stage CADASIL. METHOD: APT-II, modified to include strategy training, was applied in an A-B, multiple-probe design for an individual who had been diagnosed with early-stage CADASIL. Outcome measures included pre-post neuropsychological testing of attention, memory, and executive function; within-treatment probes of visual and auditory attention; and a measure of subjective experience of cognitive functioning in daily living. RESULTS: The participant demonstrated nominal gains on visual and auditory attention probes but improved performance on several posttreatment measures of processing speed and executive function. The participant also reported substantially improved functional outcomes following the intervention protocol. CONCLUSION: This case illustrates the potential utility of behavioral intervention for individuals with CADASIL and highlights issues for speech-language pathologists to consider when using structured cognitive training protocols in the setting of progressive cognitive decline. These data suggest that further controlled studies for treating this population are warranted.

Pyrimidine benzamide-based thrombopoietin receptor agonists.

A series of pyrimidine benzamide-based thrombopoietin receptor agonists is described. The lead molecule contains a 2-amino-5-unsubstituted thiazole, a group that has been associated with idiosyncratic toxicity. The potential for metabolic oxidation at C-5 of the thiazole, the likely source of toxic metabolites, was removed by substitution at C-5 or by replacing the thiazole with a thiadiazole. Potency in the series was improved by modifying the substituents on the pyrimidine and/or on the thiazole or thiadiazole pendant aryl ring. In vivo examination revealed that compounds from the series are not highly bioavailable. This is attributed to low solubility and poor permeability.

Discovery of 3-OH-3-methylpipecolic hydroxamates: potent orally active inhibitors of aggrecanase and MMP-13.

A series of 3-hydroxy-3-methylpipecolic hydroxamate inhibitors of MMP-13 and aggrecanase was designed based on the observation of increased aggrecanase activity with substitution at the 3-position of the piperidine ring. Potency versus aggrecanase was optimized by modification of the benzyloxyarylsulfonamide group that binds in the S1' pocket. These compounds also possess markedly improved bioavailability and lower metabolic clearance compared to analogous 3,3-dimethyl-5-hydroxypipecolic hydroxamates. These improvements are attributed to lowered lipophilicity proximal to the metabolically labile hydroxamic acid. Synthesis, structure activity relationships, and in vivo efficacy data are described.

Potent pyrimidinetrione-based inhibitors of MMP-13 with enhanced selectivity over MMP-14.

Through the use of computational modeling, a series of pyrimidinetrione-based inhibitors of MMP-13 was designed based on a lead inhibitor identified through file screening. Incorporation of a biaryl ether moiety at the C-5 position of the pyrimidinetrione ring resulted in a dramatic enhancement of MMP-13 potency. Protein crystallography revealed that this moiety binds in the S(1)(') pocket of the enzyme. Optimization of the C-4 substituent of the terminal aromatic ring led to incorporation of selectivity versus MMP-14 (MT-1 MMP). Structure activity relationships of the biaryl ether substituent are presented as is pharmacokinetic data for a compound that meets our in vitro potency and selectivity goals.

3-Hydroxy-4-arylsulfonyltetrahydropyranyl-3-hydroxamic acids are novel inhibitors of MMP-13 and aggrecanase.

N-Hydroxy-3-hydroxy-4-arylsulfonyltetrahydropyranyl-3-carboxamides were designed as novel inhibitors of MMP-13 and aggrecanase based on known endocyclic hydroxamate inhibitors of matrix metalloproteinases. These compounds offer favorable physicochemical properties and low metabolic clearance. Synthesis and structure-activity relationships are reported.