TGF-beta proteins are main regulators of blood vessel development and maintenance. Here, we report an unprecedented link between TGF-beta signaling and arterial hypertension based on the analysis of mice mutant for Emilin1, a cysteine-rich secreted glycoprotein expressed in the vascular tree. Emilin1 knockout animals display increased blood pressure, increased peripheral vascular resistance, and reduced vessel size. Mechanistically, we found that Emilin1 inhibits TGF-beta signaling by binding specifically to the proTGF-beta precursor and preventing its maturation by furin convertases in the extracellular space. In support of these findings, genetic inactivation of Emilin1 causes increased TGF-beta signaling in the vascular wall. Strikingly, high blood pressure observed in Emilin1 mutants is rescued to normal levels upon inactivation of a single TGF-beta1 allele. This study highlights the importance of modulation of TGF-beta availability in the pathogenesis of hypertension.

The mechanisms underlying sterol transport in mammalian cells are poorly understood. In particular, how cholesterol internalized from HDL is made available to the cell for storage or modification is unknown. Here, we describe three ER-resident proteins (Aster-A, -B, -C) that bind cholesterol and facilitate its removal from the plasma membrane. The crystal structure of the central domain of Aster-A broadly resembles the sterol-binding fold of mammalian StARD proteins, but sequence differences in the Aster pocket result in a distinct mode of ligand binding. The Aster N-terminal GRAM domain binds phosphatidylserine and mediates Aster recruitment to plasma membrane-ER contact sites in response to cholesterol accumulation in the plasma membrane. Mice lacking Aster-B are deficient in adrenal cholesterol ester storage and steroidogenesis because of an inability to transport cholesterol from SR-BI to the ER. These findings identify a nonvesicular pathway for plasma membrane to ER sterol trafficking in mammals.

Chromatin modifications are sensitive to environmental and nutritional stimuli. Abnormalities in epigenetic regulation are associated with metabolic disorders such as obesity and diabetes that are often linked with defects in oxidative metabolism. Here, we evaluated the potential of class-specific synthetic inhibitors of histone deacetylases (HDACs), central chromatin-remodeling enzymes, to ameliorate metabolic dysfunction. Cultured myotubes and primary brown adipocytes treated with a class I–specific HDAC inhibitor showed higher expression of Pgc-1α, increased mitochondrial biogenesis, and augmented oxygen consumption. Treatment of obese diabetic mice with a class I– but not a class II–selective HDAC inhibitor enhanced oxidative metabolism in skeletal muscle and adipose tissue and promoted energy expenditure, thus reducing body weight and glucose and insulin levels. These effects can be ascribed to increased Pgc-1α action in skeletal muscle and enhanced PPARγ/PGC-1α signaling in adipose tissue. In vivo ChIP experiments indicated that inhibition of HDAC3 may account for the beneficial effect of the class I–selective HDAC inhibitor. These results suggest that class I HDAC inhibitors may provide a pharmacologic approach to treating type 2 diabetes.

Paired helical filaments (PHF) are the principal pathologic components of neurofibrillary tangles in Alzheimer's disease (AD). To reproduce the formation of PHF in tissue culture, we stably expressed human tau with and without pathogenic mutations in human SH-SY5Y cells and exposed them for 5 days to aggregated synthetic ␤-amyloid peptide (A␤ 42 ). This caused a decreased solubility of tau along with the generation of PHF-like tau-containing filaments. These were 20 nm wide and had periodicities of 130 -140 nm in the presence of P301L mutant tau or 150 -160 nm in the presence of wild-type tau. Mutagenesis of the phosphoepitope serine 422 of tau prevented both the A␤ 42 -mediated decrease in solubility and the generation of PHF-like filaments, suggesting a role of serine 422 or its phosphorylation in tau filament formation. Together, our data underscore a role of A␤ 42 in the formation of PHF-like filaments. Our culture system will be useful to map phosphoepitopes of tau involved in PHF formation and to identify and characterize modifiers of the tau pathology. Further adaptation of the system may allow the screening and validation of compounds designed to prevent PHF formation. Neurofibrillary tangles (NFT)1 are abundant in many neurodegenerative diseases, including Alzheimer's disease (AD) and frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17) caused by mutations in the tau gene (1-3). NFT are composed of filamentous aggregates that include paired helical filaments (PHF) and narrow twisted ribbons. These are made of the microtubule-associated protein tau (4, 5). Tau in these filaments is hyperphosphorylated both at physiological sites and at additional, pathological sites. Phosphorylation of tau is associated with the dissociation of tau from microtubules and with its relocalization from axons to cell bodies and dendrites. Pathologic increases in this pool of soluble tau, along with conformational changes of the natively unfolded tau, are initial critical steps in the assembly of the more insoluble pathological tau filaments.Transgenic mice expressing pathogenic mutations of human tau generate a few low abundant NFT (6, 7), and both intracerebral microinjections of ␤-amyloid into P301L mutant tau transgenic mice and co-expression of mutant amyloid precursor protein greatly accelerate the rate of NFT formation in mice (8,9). These data established a mechanistic relationship of ␤-amyloid toxicity with NFT formation.To circumvent the inherent limitations of the above in vivo experiments (including poor breeding of doubly transgenic mice as well as stereotaxic techniques) and to establish PHF formation in tissue culture, we expressed both wild-type and mutant forms of human tau in human SH-SY5Y cells and exposed them to preparations of aggregated synthetic ␤-amyloid. We were able to produce bona fide PHF-like tau filaments within 5 days of tissue culture. EXPERIMENTAL PROCEDURESSite-directed Mutagenesis-The longest human 4-repeat tau isoform, htau40, was cloned into the pRc/RSV expression ve...

Plasma membranes of animal cells are enriched for cholesterol. Cholesterol-dependent cytolysins (CDCs) are pore forming toxins secreted by bacteria that target membrane cholesterol for their effector function. Phagocytes are essential for clearance of CDC-producing bacteria; however, mechanisms these cells use to evade the deleterious effects of CDCs are largely unknown. Here, we report that interferon (IFN) signals convey resistance to CDC-induced pores on macrophages Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:http://www.nature.com/authors/editorial_policies/license.html#terms

Background & Aims Great interest has been raised by the possible protective role of vitamin D in coronavirus disease 2019 (COVID-19), but objective data on 25(OH)vitamin D deficiency in hospitalized COVID-19 patients are not conclusive. The aim of this study was to determine the prevalence of 25(OH)vitamin D deficiency in COVID-19 patients admitted to an Italian referral hospital and explore its association with clinical outcomes and the markers of disease severity. Methods In this single-center cohort study, 129 consecutive adult COVID-19 patients hospitalized in an Italian referral center were enrolled from March to April 2020. 25(OH)Vitamin D serum levels were assessed 48 hours since hospital admission and categorized into: normal (≥30 ng/mL), insufficient (<30 - ≥20 ng/mL), moderately deficient (<20 - ≥10 ng/mL), severely deficient (<10 ng/mL). Results The prevalence of 25(OH)vitamin D insufficiency, moderate deficiency and severe deficiency was 13.2%, 22.5% and 54.3%, respectively. 25(OH)Vitamin D deficiency (<20 ng/mL) was not associated with COVID-19 clinical features and outcomes. Unexpectedly, after adjusting for major confounders, a significant positive association between increasing 25(OH)vitamin D levels and in-hospital mortality (on a continuous logarithmic scale, odds ratio=1.73 [95% CI, 1.11 to 2.69]; P=.016) was observed. Conclusions Very low 25(OH)vitamin D levels were highly prevalent and suggestive of deficiency among our hospitalized severe COVID-19 patients, but low 25(OH)vitamin D levels were not associated with outcome variables. Whether 25(OH)vitamin D adequacy may influence clinical outcomes in COVID-19 and the unexpected correlation between higher 25(OH)vitamin D levels and mortality require further investigations by large intervention trials.

Alzheimer's disease (AD) is characterized histopathologically by beta-amyloid-containing plaques, neurofibrillary tangles (NFT), reduced synaptic density, and neuronal loss in selected brain areas. Plaques consist of aggregates of a small peptide termed Abeta which is derived by proteolysis of the larger amyloid precursor protein APP, whereas NFT are composed of hyperphosphorylated forms of the microtubule-associated protein tau. Tau pathology in the presence of scant or no beta-amyloid plaques characterizes additional neurodegenerative disorders collectively called tauopathies. In the course of plaque and NFT formation, the major proteinaceous components of these lesions undergo post-translational modifications. In the case of tau, these include phosphorylation of mainly serine and threonine, but also tyrosine residues. In addition, tau is subject to ubiquitination, nitration, truncation, prolyl isomerization, association with heparan sulfate proteoglycan, glycosylation, glycation and modification by advanced glycation end-products (AGEs). This review aims to provide insight into the complexity of tau modifications in human tauopathies such as AD and frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17). Selected aspects of the post-translational modification of tau have been reproduced in transgenic animal models. Most of this work has been done in mice, but insight has also been gained from studies in the sea lamprey, the nematode C. elegans and Drosophila. Attempts have been made to link specific post-translational modifications with tau aggregation and nerve cell dysfunction.

Objective: To develop a consensus on the diagnostic criteria for chronic endometritis (CE) at hysteroscopy (HSC), and to evaluate these proposed criteria in a randomized-controlled observer study. Design: Systematic review of studies evaluating the diagnostic accuracy of HSC in CE diagnosis; Delphi consensus on hysteroscopic diagnostic criteria for CE; randomized-controlled observer study to evaluate the reproducibility of the proposed diagnostic criteria. Setting: Not applicable. Participant(s): Experts from different countries were involved in the systematic review and contributed to the Delphi consensus. Physicians from different countries were involved in the observer study. Intervention(s): After reaching consensus on the diagnostic criteria, the Delphi poll created a questionnaire including 100 hysteroscopic pictures (50 from women with CE [domain 1] and 50 from women without CE [domain 2]), with a single question per picture (Answer_A: suggestive of CE; answer B: not suggestive of CE). A total of 200 physicians were invited to take part in the observer study. Before completing the questionnaire, physicians were randomized to receive a description of the diagnostic criteria (group A) or no such information (group B). Main Outcome Measure(s): The primary outcome was to compare the questionnaire scores for the two groups of observers. The secondary outcome was to assess the interobserver agreement in the diagnosis of CE in each group. Result(s): A total of 126 physicians completed the questionnaire (62 in group A and 64 in group B). Observers in group A obtained higher total scores compared with those in group B (P< .001). Specifically, group A showed higher mean score in domain 1 (P< .001), but not in domain 2 (P¼ .975). A substantial agreement was found among observers in group A (intraclass correlation coefficient [ICC] 0.78), whereas a fair agreement was found among observers in group B (ICC 0.40). Conclusion(s):This randomized-controlled observer study found a positive impact of our criteria on physicians' ability to recognize CE. (Fertil Steril Ò 2019;112:162-73. Ó2019 by American Society for Reproductive Medicine.) El resumen está disponible en Español al final del artículo.