Background: Numerous pieces of evidence have indicated that thoracic aortic dissection (TAD) is an inflammatory disease. Sphingosine-1-phosphate receptor 2 (S1PR2) signaling is a driver in multiple inflammatory diseases. Here, we examined the S1PR2 expression in TAD lesions and explored the effect of interfering with S1PR2 on TAD formation and progression. Methods: Aorta specimens and blood samples were collected from patients with TAD and matched controls. The expression of S1PR1, S1PR2, and S1PR3 was examined. The effect of inhibiting S1PR2 on TAD was evaluated in a TAD mouse model induced by β-aminopropionitrile fumarate (BAPN) and AngII. The presence of sphingosine kinase 1 (SPHK1), S1P, and neutrophil extracellular traps (NETs) was investigated. Further, the possible association between S1PR2 signaling and NETs in TAD was analyzed. Results: In the aortic tissues of patients with TAD and a mouse model, the S1PR2 expression was significantly up-regulated. In the TAD mouse model, JTE013, a specific S1PR2 antagonist, not only blunted the TAD formation and aortic rupture, but also preserved the elastic fiber architecture, reduced the smooth muscle cells apoptosis level, and mitigated the aortic wall inflammation. Augmented tissue protein expression of SPHK1, citrullinated histone H3 (CitH3, a specific marker of NETs), and serum S1P, CitH3 were detected in TAD patients. Surgical repair normalized the serum S1P and CitH3 levels. Immunofluorescence staining revealed that S1PR2 colocalized with NETs. The protein expression levels of SPHK1 and serum S1P levels positively correlated with the protein expression and serum levels of CitH3, separately. Furthermore, JTE013 treatment reduced NETs accumulation. Conclusion: Inhibiting S1PR2 attenuates TAD formation and prevents aortic rupture. Targeting S1PR2 may provide a promising treatment strategy against TAD.
Aldosterone is one of the most essential hormones synthesized by the adrenal gland because it regulates water and electrolyte balance. G protein–coupled estrogen receptor (GPER) is a newly discovered aldosterone receptor, which is proposed to mediate the non-genomic pathways of aldosterone while the hormone simultaneously interacts with mineralocorticoid receptor. In contrast to its cardio-protective role in postmenopausal women via its interaction with estrogen, GPER seems to trigger vasoconstriction effects and can further induce water and sodium retention in the presence of aldosterone, indicating two entirely different binding sites and effects for estrogen and aldosterone. Accumulating evidence also points to a role of aldosterone in mediating hypertension and its risk factors via the interaction with GPER. Therefore, with this review, we aimed to summarize the research on these interactions to help (1) elucidate the role of GPER activated by aldosterone in the blood vessels, heart, and kidney; (2) compare the non-genomic actions between aldosterone and estrogen mediated by GPER; and (3) address the potential of GPER as a new promising therapeutic target for aldosterone-induced hypertension.
Background and Purpose Hypertension has been the leading preventable cause of premature death worldwide. The aim of this study was to design a more efficient vaccine against novel targets for the treatment of hypertension. Experimental Approach The epitope CE12, derived from the human L‐type calcium channel (Ca V 1.2), was designed and conjugated with Qβ bacteriophage virus‐like particles to test the efficacy in hypertensive animals. Further, the hepatitis B core antigen (HBcAg)‐CE12‐CQ10 vaccine, a bivalent vaccine based on HBcAg virus‐like particles and targeting both human angiotensin AT 1 receptors and Ca V 1.2 channels, was developed and evaluated in hypertensive rodents. Key Results The Qβ‐CE12 vaccine effectively decreased the BP in hypertensive rodents. A monoclonal antibody against CE12 specifically bound to L‐type calcium channels and inhibited channel activity. Injection with monoclonal antibody against CE12 effectively reduced the BP in angiotensin II‐induced hypertensive mice. The HBcAg‐CE12‐CQ10 vaccine showed antihypertensive effects in hypertensive mice and relatively superior antihypertensive effects in spontaneously hypertensive rats and ameliorated L‐NAME‐induced renal injury. In addition, no obvious immune‐mediated damage or electrophysiological adverse effects were detected. Conclusion and Implications Immunotherapy against both AT 1 receptors and Ca V 1.2 channels decreased the BP in hypertensive rodents effectively and provided protection against hypertensive target organ damage without obvious feedback activation of renin‐angiotensin system or induction of dominant antibodies against the carrier protein. Thus, the HBcAg‐CE12‐CQ10 vaccine may provide a novel and promising therapeutic approach for hypertension.
The alpha1A-adrenergic receptor (α1A-AR) regulates various vascular functions and participates in the pathogenesis of primary hypertension. However, highly specific and subtype-selective antagonists of α1A-AR have not been developed. Two novel antibodies against the short peptides CP-7, which is located in the second extracellular loop of α1A-AR, and CPE-8, which is located in the third extracellular loop of α1A-AR, were prepared. The two antibodies specifically bound to α1A-AR. However, neither antibody prevented [3H]-epinephrine or [3H]-prazosin from binding to the receptor. In vitro, the anti-CP-7 antibody inhibited Ca2+-dependent signal transduction processes including protein kinase C translocation and extracellular signal-regulated kinase (ERK1/2) phosphorylation induced by phenylephrine (PHE). The anti-CP-7 antibody decreased the beating rates of neonatal rat cardiomyocytes with or without PHE stimulation and reduced the blood pressure of spontaneously hypertensive rats that were immunized with CP-7-keyhole limpet haemocyanin. The anti-CP-7 antibody specifically inhibited the activation of α1A-AR both in vitro and in vivo. No competition binding was found between anti-CP-7 and [3H]-epinephrine or [3H]-prazosin. An antibody that specifically inhibits a receptor could be useful in research on G-protein-coupled receptors that lack specific antagonists. The antibody against the epitope CP-7 might have potential in a therapeutic application for treating primary hypertension.
Immune checkpoint inhibitors (ICIs) have now emerged as a mainstay of treatment for various cancer. Along with the development of ICIs, immune-related adverse effects (irAEs) have been the subject of wide attention. The cardiac irAE, a rare but potentially fatal and fulminant effect, have been reported recently. This article retrospectively reviewed 10 cases from our hospital with cardiac irAEs, with severity ranging from asymptomatic troponin-I elevations to cardiac conduction abnormalities and even fulminant myocarditis. In our series, all the cases were solid tumors and lung cancer was the most frequent cancer type (4,40%). In total, three (30.0%) patients experienced more than one type of life-threatening complication. A systemic corticosteroid was given to nine patients (90.0%). The majority of cases (7, 70%) were performed at an initial dose of 1-2 mg/kg/day. Two (20.0%) patients were admitted to ICU, three (30.0%) patients were put on mechanical ventilation, two (20.0%) patients received the plasma exchange therapy, and one patient was implanted with a pacemaker. Two (20.0%) of the patients succumbed and died, with a median duration of 7.5 days (IQR5.0-10.0) from diagnosis of cardiac irAE to death. Based on these results, we recommend that clinicians be alert to cardiac irAEs, including performing cardiovascular examinations before ICI treatment to accurately diagnose suspected myocarditis, enabling immediate initiation of immunosuppressive therapy to improve prognosis.
Increasing evidence supports a role for cytokines as chemical signals in the CNS, either under normal conditions or in the pathologic state. CNS levels of the cytokine interleukin-6 (IL-6) are known to be elevated in several diseases associated with developmental disorders and may contribute to the pathological state. To investigate the potential role of IL-6 in such disorders, neuronal effects of IL-6 were examined during development using an in vitro model system, cultured rat cerebellar granule neurons. The cultures were prepared from 8 d postnatal rat pups and exposed chronically to IL-6 (5 ng/ml) by addition to the culture medium. Neuronal effects of IL-6 were assessed by a comparison of calcium signals produced in control and IL-6 treated neurons by the glutamate receptor agonists NMDA and domoate and by K+ depolarization. IL-6 treatment significantly enhanced the response to NMDA and altered the developmental pattern of NMDA sensitivity, whereas only minor changes were observed for the response to domoate and K+. Reducing extracellular calcium and depleting intracellular stores significantly decreased the amplitude of the response to NMDA in control and IL-6 treated neurons. However, the IL-6 treated neurons were significantly more sensitive to these treatments than control neurons. These results suggest that elevated levels of IL-6 can significantly alter CNS neuron development and response to excitatory transmitters, and that IL-6 pretreatment selectively enhances the intracellular calcium responses to NMDA by altering the relative contribution of extracellular calcium influx and release of calcium from stores to the calcium signal.
The angiotensin II type 1 receptor (AT1R) signaling pathway is reported to modulate glucose metabolism. Targeting AT1R, our group invented ATRQβ-001 vaccine, a novel immunotherapeutic strategy to block the activation of AT1R. Here, we evaluated the therapeutic efficacy of ATRQβ-001 vaccine in insulin resistance, and investigated the mechanism. Our results showed that ATRQβ-001 vaccine and specific monoclonal antibody against epitope ATR-001 (McAb-ATR) decreased fasting serum insulin concentration and improved glucose and insulin tolerance in ob/ob mice. These beneficial effects were verified in high-fat diet-induced obese mice. McAb-ATR activated insulin signaling in skeletal muscle and insulin-resistant C2C12 myotubes without affecting liver or white adipose tissue of ob/ob mice. Mechanistically, the favorable impact of McAb-ATR on insulin resistance was abolished in db/db mice and in C2C12 myotubes with leptin receptor knockdown. AT1R knockdown also eradicated the effects of McAb-ATR in C2C12 myotubes. Furthermore, McAb-ATR treatment was able to activate the leptin receptor-mediated JAK2/STAT3 signaling in skeletal muscle of ob/ob mice and C2C12 myotubes. Additionally, angiotensin II downregulated the leptin signaling in skeletal muscle of ob/ob and diet-induced obese mice. We demonstrated that ATRQβ-001 vaccine and McAb-ATR improved whole-body insulin resistance and regulated glucose metabolism in skeletal muscle in a leptin receptor-dependent manner. Our data suggest that immunotherapy targeting AT1R is a novel strategy for treating insulin resistance.