Proline-rich tyrosine kinase Pyk2 regulates deep vein thrombosis

Deep vein thrombosis results from the cooperative action of leukocytes, platelets, and endothelial cells. The proline-rich tyrosine kinase Pyk2 regulates platelet activation and supports arterial thrombosis. In this study, we combined pharmacological and genetic approaches to unravel the role of Pyk2 in venous thrombosis. We found that mice lacking Pyk2 almost completely failed to develop deep venous thrombi upon partial ligation of the inferior vena cava. Pyk2-deficient platelets displayed impaired exposure of phosphatidylserine and tissue factor expression by endothelial cells and monocytes was completely prevented by inhibition of Pyk2. In human umbilical vein endothelial cells (HUVEC), inhibition of Pyk2 hampered IL-1β-induced expression of VCAM and P-selectin, and von Willebrand factor release. Pyk2-deficient platelets showed defective adhesion on von Willebrand factor and reduced ability to bind activated HUVEC under flow. Moreover, inhibition of Pyk2 in HUVEC strongly reduced platelet adhesion. Similarly, Pyk2-deficient neutrophils were unable to efficiently roll and adhere to immobilized endothelial cells under venous flow conditions. Moreover, platelets and neutrophils from Pyk2-knockout mice showed defective ability to form heterogeneous aggregates upon stimulation, while platelet monocyte interaction occurred normally. Consequently, platelet neutrophil aggregates, abundant in blood of wild-type mice upon inferior vena cava ligation, were virtually undetectable in Pyk2-knockout mice. Finally, we found that expression of Pyk2 was required for NETosis induced by activated platelets. Altogether our results demonstrate a critical role of Pyk2 in the regulation of the coordinated thromboinflammatory responses of endothelial cells, leukocytes and platelets leading to venous thrombosis. Pyk2 may represent a novel promising target in the treatment of deep vein thrombosis.     

Color Conversion Light-Emitting Diodes Based on Carbon Dots: A Review

This paper reviews the state-of-the-art technologies, characterizations, materials (precursors and encapsulants), and challenges concerning multicolor and white light-emitting diodes (LEDs) based on carbon dots (CDs) as color converters. Herein, CDs are exploited to achieve emission in LEDs at wavelengths longer than the pump wavelength. White LEDs are typically obtained by pumping broad band visible-emitting CDs by an UV LED, or yellow–green-emitting CDs by a blue LED. The most important methods used to produce CDs, top-down and bottom-up, are described in detail, together with the process that allows one to embed the synthetized CDs on the surface of the pumping LEDs. Experimental results show that CDs are very promising ecofriendly candidates with the potential to replace phosphors in traditional color conversion LEDs. The future for these devices is bright, but several goals must still be achieved to reach full maturity.     

HOXD8 hypermethylation as a fully sensitive and specific biomarker for biliary tract cancer detectable in tissue and bile samples

Background Biliary tract cancers (BTC) are rare but highly aggressive tumours with poor prognosis, usually detected at advanced stages. Herein, we aimed at identifying BTC-specific DNA methylation alterations.Methods Study design included statistical power and sample size estimation. A genome-wide methylation study of an explorative cohort (50 BTC and ten matched non-tumoral tissue samples) has been performed. BTC-specific altered CpG islands were validated in over 180 samples (174 BTCs and 13 non-tumoral controls). The final biomarkers, selected by a machine-learning approach, were validated in independent tissue (18 BTCs, 14 matched non-tumoral samples) and bile (24 BTCs, five non-tumoral samples) replication series, using droplet digital PCR.Results We identified and successfully validated BTC-specific DNA methylation alterations in over 200 BTC samples. The two-biomarker panel, selected by an in-house algorithm, showed an AUC > 0.97. The best-performing biomarker (chr2:176993479-176995557), associated with HOXD8, a pivotal gene in cancer-related pathways, achieved 100% sensitivity and specificity in a new series of tissue and bile samples.Conclusions We identified a novel fully efficient BTC biomarker, associated with HOXD8 gene, detectable both in tissue and bile by a standardised assay ready-to-use in clinical trials also including samples from non-invasive matrices.Subject terms: Diagnostic markers, Biliary tract cancer     

Female sexual behavior is disrupted in a preclinical mouse model of PCOS via an attenuated hypothalamic nitric oxide pathway

Women with polycystic ovary syndrome (PCOS) frequently experience decreased sexual arousal, desire, and sexual satisfaction. While the hypothalamus is known to regulate sexual behavior, the specific neuronal pathways affected in patients with PCOS are not known. To dissect the underlying neural circuitry, we capitalized on a robust preclinical animal model that reliably recapitulates all cardinal PCOS features. We discovered that female mice prenatally treated with anti-Müllerian hormone (PAMH) display impaired sexual behavior and sexual partner preference over the reproductive age. Blunted female sexual behavior was associated with increased sexual rejection and independent of sex steroid hormone status. Structurally, sexual dysfunction was associated with a substantial loss of neuronal nitric oxide synthase (nNOS)-expressing neurons in the ventromedial nucleus of the hypothalamus (VMH) and other areas of hypothalamic nuclei involved in social behaviors. Using in vivo chemogenetic manipulation, we show that nNOS^VMH neurons are required for the display of normal sexual behavior in female mice and that pharmacological replenishment of nitric oxide restores normal sexual performance in PAMH mice. Our data provide a framework to investigate facets of hypothalamic nNOS neuron biology with implications for sexual disturbances in PCOS.

Polycystic ovary syndrome (PCOS) is a highly prevalent disease affecting 5 to 18% of women of reproductive age worldwide (1, 2). PCOS is diagnosed upon the presence of at least two out of three prime features: high circulating levels of androgens (hyperandrogenism), menstrual irregularities (oligo-anovulation), and polycystic-like ovarian morphology (2, 3). Beyond its implications leading to female infertility, the disease is associated with several metabolic disruptions, cardiovascular diseases, and psychosocial disorders (4). Among these neurological implications, it has become clear that approximately 30% or more of patients with PCOS experience sexual dysfunctions, with clinical studies reporting a high risk of low sexual arousal, desire, and satisfaction and impaired lubrication and orgasm (5–9). These symptoms allude to disturbances in brain circuits controlling sexual function in the context of PCOS.Neural circuits driving female sexual behaviors are conserved among vertebrate species operating under the influence of sex steroid hormone modulation, which is paramount for partner interaction, receptivity, and sexual performance (10, 11). Indeed, gonadal sex hormones are implicated in shaping circuit architecture in the hypothalamus during development and activating these neonatally programmed circuits over reproductive adult life in many species (12–16). The hypothalamus integrates sensorial stimuli and autonomic arousal from endogenous sex drive cues (e.g., estrous phase, energy status, hormone milieu, genital stimulation) to convey this information to other brain areas and peripheral nerves (10, 17). The ventromedial nucleus of the hypothalamus (VMH) is considered the hub of specialized neurons, with intrinsic properties driving different components of sexual behavior (18–21). The VMH harbors neurons expressing neuronal nitric oxide synthase (nNOS), the enzyme responsible for the production of nitric oxide (NO), a key gaseous neurotransmitter that stimulates female sexual behavior (22, 23) and communicates with other circuits within the social brain (24, 25). Despite current advances unraveling novel pathways in the female sexual brain with specific behavioral responses, there is a clear lack of knowledge on how disturbances in these circuits may participate in sexual dysfunctions affecting one-third of women with PCOS.Growing evidence indicates that androgen excess in utero induces a developmental reprogramming of the female fetal brain toward the manifestation of PCOS traits later in life (26–29). Some studies have suggested that the clinical signs of hyperandrogenism have detrimental sexual effects (5), indicating a negative correlation between androgen levels and sexual function in PCOS. In recent years, it has been proposed that prenatal anti-Müllerian hormone excess may trigger gestational hyperandrogenism via the inhibition of placental aromatase (29, 30) and that women with PCOS display higher circulating levels of androgens and AMH during pregnancy as compared to healthy women (29, 31). Prenatal AMH-treated mice (PAMH) reliably recapitulate all the mouse equivalents of the PCOS Rotterdam criteria (29, 32) and are thus a preclinical model to mimic the human PCOS condition. PAMH female mice also display pronounced neuroendocrine dysfunction leading to exacerbated luteinizing hormone (LH) secretion (29), as in women with PCOS (33), denoting the presence of prenatally reprogrammed defects within the gonadotropin-releasing hormone (GnRH) neuronal network. Thus, prenatal AMH excess–mediated disruptions in the female brain may be key to understanding the pathophysiology of PCOS.Here, we investigated whether prenatal AMH excess could underpin defects in sex circuits promoting sexual dysfunction in PCOS-like female mice. We uncovered a profound decrease of nNOS and progesterone receptor (PR) expression in the VMH. These anatomical changes were also associated with significant impairment of sexual receptivity in PCOS-like female mice. Nevertheless, normal sexual function in PAMH female mice was restored to control levels upon peripheral injection of NO donor. Performing a series of acute functional manipulations in freely moving female mice, we showed that chemogenetic silencing of nNOS^VMH neurons in control female mice recapitulates PCOS-like sexual dysfunctions. Taken together, we unveiled a brain pathway potentially underpinning the etiology of low sexual drive in PCOS while pointing to prospective therapeutic approaches to rescue normal sexual function in these women.