Targeting VEGF-A/VEGFR2 Y949 Signaling-Mediated Vascular Permeability Alleviates Hypoxic Pulmonary Hypertension.

BACKGROUND: Pulmonary hypertension (PH) is associated with increased expression of VEGF-A (vascular endothelial growth factor A) and its receptor, VEGFR2 (vascular endothelial growth factor 2), but whether and how activation of VEGF-A signal participates in the pathogenesis of PH is unclear. METHODS: VEGF-A/VEGFR2 signal activation and VEGFR2 Y949-dependent vascular leak were investigated in lung samples from patients with PH and mice exposed to hypoxia. To study their mechanistic roles in hypoxic PH, we examined right ventricle systolic pressure, right ventricular hypertrophy, and pulmonary vasculopathy in mutant mice carrying knock-in of phenylalanine that replaced the tyrosine at residual 949 of VEGFR2 (Vefgr2Y949F) and mice with conditional endothelial deletion of Vegfr2 after chronic hypoxia exposure. RESULTS: We show that PH leads to excessive pulmonary vascular leak in both patients and hypoxic mice, and this is because of an overactivated VEGF-A/VEGFR2 Y949 signaling axis. In the context of hypoxic PH, activation of Yes1 and c-Src and subsequent VE-cadherin phosphorylation in endothelial cells are involved in VEGFR2 Y949-induced vascular permeability. Abolishing VEGFR2 Y949 signaling by Vefgr2Y949F point mutation was sufficient to prevent pulmonary vascular permeability and inhibit macrophage infiltration and Rac1 activation in smooth muscle cells under hypoxia exposure, thereby leading to alleviated PH manifestations, including muscularization of distal pulmonary arterioles, elevated right ventricle systolic pressure, and right ventricular hypertrophy. It is important that we found that VEGFR2 Y949 signaling in myeloid cells including macrophages was trivial and dispensable for hypoxia-induced vascular abnormalities and PH. In contrast with selective blockage of VEGFR2 Y949 signaling, disruption of the entire VEGFR2 signaling by conditional endothelial deletion of Vegfr2 promotes the development of PH. CONCLUSIONS: Our results support the notion that VEGF-A/VEGFR2 Y949-dependent vascular permeability is an important determinant in the pathogenesis of PH and might serve as an attractive therapeutic target pathway for this disease.

Detection of serum antibody levels after inoculation of an inactivated SARS-CoV-2 vaccine / 预防医学

Objective @#To investigate the serum levels of antibodies against SARS-CoV-2 after inoculation of an inactivated SARS-CoV-2 vaccine, so as to provide insights into the evaluation of the vaccine immunogenicity. @*Methods @#In this single-arm Objective performance criteria trial, residents aged 18 to 59 years and inoculated with an inactivated SARS-CoV-2 vaccine in Xihu District, Hangzhou City from October to December of 2020 were selected using a cluster sampling method. Blood samples were collected prior to inoculation, 14 and 28 days post-inoculation of the first dose, and 28 days post-inoculation of the second dose. Serum levels of anti-SARS-CoV-2 IgM and IgG antibodies were detected using the magnetic particle-based chemiluminescence immunoassay. The seroconversion of antibodies and dynamic changes of antibody levels were analyzed.@*Results @#Totally 310 participants were enrolled, including 133 subjects on day 14 post-inoculation of the first dose, 97 subjects on day 28 post-inoculation of the first dose and 254 subjects on day 28 post-inoculation of the second dose. The seroconversion rates of anti-SARS-CoV-2 IgG antibody were 6.02%, 28.87% and 98.43%, and the median IgG antibody levels were 1.76 ( interquartile range, 3.25 ), 5.69 ( 9.95 ) and 52.05 ( 47.60 ) AU/mL ( P<0.05 ), respectively, while the seroconversion rates of anti-SARS-CoV-2 IgM antibody were 9.02%, 11.34% and 12.99%, and the median IgG antibody levels were 1.89 ( 3.28 ), 2.06 ( 4.71 ) and 2.65 ( 4.01 ) AU/mL ( P>0.05 ), respectively. In addition, higher serum levels of anti-SARS-CoV-2 IgG and IgM antibodies were detected post-inoculation relative to pre-inoculation ( P<0.05 ), and higher serum IgG antibody levels were found in subjects aged 18 to 39 years than in those aged 40 to 59 years ( P<0.05 ). @*Conclusions @#Inoculation of two doses of the inactivated SARS-CoV-2 vaccine achieves a high immunogenicity among residents aged 18 to 59 years 28 days post-inoculation, and the anti-SARS-CoV-2 IgM antibody is detectable in some residents following inoculation of the first dose.

Fear Memory Recall Potentiates Opiate Reward Sensitivity through Dissociable Dopamine D1 versus D4 Receptor-Dependent Memory Mechanisms in the Prefrontal Cortex.

Disturbances in prefrontal cortical (PFC) dopamine (DA) transmission are well established features of psychiatric disorders involving pathological memory processing, such as post-traumatic stress disorder and opioid addiction. Transmission through PFC DA D4 receptors (D4Rs) has been shown to potentiate the emotional salience of normally nonsalient emotional memories, whereas transmission through PFC DA D1 receptors (D1Rs) has been demonstrated to selectively block recall of reward- or aversion-related associative memories. In the present study, using a combination of fear conditioning and opiate reward conditioning in male rats, we examined the role of PFC D4/D1R signaling during the processing of fear-related memory acquisition and recall and subsequent sensitivity to opiate reward memory formation. We report that PFC D4R activation potentiates the salience of normally subthreshold fear conditioning memory cues and simultaneously potentiates the rewarding effects of systemic or intra-ventral tegmental area (VTA) morphine conditioning cues. In contrast, blocking the recall of salient fear memories with intra-PFC D1R activation, blocks the ability of fear memory recall to potentiate systemic or intra-VTA morphine place preference. These effects were dependent upon dissociable PFC phosphorylation states involving calcium-calmodulin-kinase II or extracellular signal-related kinase 1-2, following intra-PFC D4 or D1R activation, respectively. Together, these findings reveal new insights into how aberrant PFC DAergic transmission and associated downstream molecular signaling pathways may modulate fear-related emotional memory processing and concomitantly increase opioid addiction vulnerability.SIGNIFICANCE STATEMENT Post-traumatic stress disorder is highly comorbid with addiction. In this study, we use a translational model of fear memory conditioning to examine how transmission through dopamine D1 or D4 receptors, in the prefrontal cortex (PFC), may differentially control acquisition or recall of fear memories and how these mechanisms might regulate sensitivity to the rewarding effects of opioids. We demonstrate that PFC D4 activation not only controls the salience of fear memory acquisition, but potentiates the rewarding effects of opioids. In contrast, PFC D1 receptor activation blocks recall of fear memories and prevents potentiation of opioid reward effects. Together, these findings demonstrate novel PFC mechanisms that may account for how emotional memory disturbances might increase the addictive liability of opioid-class drugs.