Relaxin (RLN) is a systemic hormone from the corpus luteum, and its levels remain low during normal human gestation. Indeed, elevation of circulating RLN has long been associated with preterm birth, for which there has been no physiological explanation. Recent studies have shown that RLN suppresses endotoxin-induced cytokine secretion from THP-1 monocytic cells by acting on the glucocorticoid receptor (GR), but its effects on primary macrophages are unknown. Therefore, in the present study, we examined the effects of RLN on cytokine secretion from primary decidual macrophages (DMs) obtained at term before labor. Unlike THP-1 cells, RLN had no effects on the cytokine responses induced by either lipopolysaccharide (LPS) or interleukin (IL) 1B, mimicking infection-induced or sterile inflammation, respectively. However, RLN alone for 4 h significantly decreased (P < 0.05) colony-stimulating factor 2 (CSF2; also known as granulocyte-macrophage colony-stimulating factor) and IL8 but for 24 h significantly increased IL6 (P < 0.01). We show that DMs express both the RLN receptor (RXFP1) and the GR. RLN suppression of CSF2 and IL8 was sensitive to the GR-antagonist mifepristone (RU-486). However, RLN activation of RXFP1 induced a dose-dependent cAMP response, which when mimicked by forskolin also caused significantly increased (P < 0.05) secretion of IL6. Thus, RLN may be anti-inflammatory in DMs via activation of the GR but proinflammatory via activation of RXFP1 and cAMP. In summary, we have shown that RLN targeting DMs may modulate proinflammatory cytokine secretion at the maternal-fetal interface and contribute to the localized inflammatory response associated with parturition in women.

Stokes (2014) The calcium release-activated calcium channel Orai1 represents a crucial component in hypertrophic compensation and the development of dilated cardiomyopathy, Channels, 8:1,[35][36][37][38][39][40][41][42][43]

Zika Virus (ZIKV), a virus with no severe clinical symptoms or sequelae previously associated with human infection, became a public health threat following an epidemic in French Polynesia 2013–2014 that resulted in neurological complications associated with infection. Although no treatment currently exists, several vaccines using different platforms are in clinical development. These include nucleic acid vaccines based on the prM-E protein from the virus and purified formalin-inactivated ZIKV vaccines (ZPIV) which are in Phase 1/2 clinical trials. Using a recombinant subunit platform consisting of antigens produced in Drosophila melanogaster S2 cells, we have previously shown seroconversion and protection against viremia in an immunocompetent mouse model. Here we demonstrate the efficacy of our recombinant subunits in a non-human primate (NHP) viremia model. High neutralizing antibody titers were seen in all protected macaques and passive transfer demonstrated that plasma from these NHPs was sufficient to protect against viremia in mice subsequently infected with ZIKV. Taken together our data demonstrate the immunogenicity and protective efficacy of the recombinant subunit vaccine candidate in NHPs as well as highlight the importance of neutralizing antibodies in protection against ZIKV infection and their potential implication as a correlate of protection.

Heart failure is becoming a global epidemic. It exerts a staggering toll on quality of life, and substantial medical and economic impact. In a pre-clinical model of cardiac hypertrophy and heart failure, we were able to overcome loss of heart function by administering the TRPV1 antagonist BCTC (4-(3-Chloro-2-pyridinyl)-N-[4-(1,1-dimethylethyl)phenyl]-1-piperazinecarboxamide). The results presented here identify TRPV1 antagonists as new treatment options for cardiac hypertrophy and heart failure.

Two-pore channels (TPC1, 2, and 3) are recently identified endolysosmal ion channels, but remain poorly characterized. In this study, we show for the first time a role for TPC1 in cytokinesis, the final step in cell division. HEK 293 T-REx cells inducibly overexpressing TPC1 demonstrated a lack of proliferation accompanied by multinucleation and an increase in G2/M cycling cells. Increased TPC1 was associated with a concomitant accumulation of active RhoGTP and a decrease in phosphorylated myosin light chain (MLC). Finally, we demonstrated a novel interaction between TPC1 and citron kinase (CIT). These results identify TPC1 as a central component of cytokinetic control, specifically during abscission, and introduce a means by which the endolysosomal system may play an active role in this process.

Activation of the atrial natriuretic signaling pathway is intrinsic to the pathological responses associated with a range of cardiovascular diseases that stress the heart, especially those involved in sustained cardiac pressure overload which induces hypertrophy and the pathological remodeling that frequently leads to heart failure. We identify transient receptor potential cation channel, subfamily V, member 1, as a regulated molecular component, and therapeutic target of this signaling system. Data show that TRPV1 is a physical component of the natriuretic peptide A, cGMP, PKG signaling complex, interacting with the Natriuretic Peptide Receptor 1 (NPR1), and upon binding its ligand, Natriuretic Peptide A (NPPA, ANP) TRPV1 activation is subsequently suppressed through production of cGMP and PKG mediated phosphorylation of the TRPV1 channel. Further, inhibition of TRPV1, with orally delivered drugs, suppresses chamber and myocyte hypertrophy, and can longitudinally improve in vivo heart function in mice exposed to chronic pressure overload induced by transverse aortic constriction, reversing pre-established hypertrophy induced by pressure load while restoring chamber function. TRPV1 is a physical and regulated component of the natriuretic peptide signaling system, and TRPV1 inhibition may provide a new treatment strategy for treating, and reversing the loss of function associated with cardiac hypertrophy and heart failure.

Intrauterine infection frequently leads to preterm birth (PTB), with the pathophysiology involving activation of the innate immune system and its associated inflammatory response. The choriodecidua produces relaxin (RLN) and elevated levels are associated with preterm premature rupture of the fetal membranes. However, it is not increased in bacterially-mediated PTB, but may act as an endogenous sterile inflammatory mediator. Elevated systemic RLN levels from the corpus luteum are also associated with PTB, but the mechanism is unknown. In clinical obstetrics, intrauterine inflammation or infection can coexist with elevated RLN. Therefore, in this study, we further characterized the effects of RLN alone or together with an inflammatory mediator on the production of IL1B, CSF2 (GM-CSF), IL6, IL8 and TNF, from chorionic cytotrophoblasts (CyT), decidual fibroblasts (DF) and stromal cells (DSC), using interleukin-1 beta (IL1B) to mimic sterile inflammation or lipopolysaccharide (LPS) for bacterial infection. Endogenous differences between the cells showed that the CyT expressed more and the RXFP1, its receptor RXFP1 splice variant D. CyT also showed the most robust cAMP response to RLN with increased IL6 secreted after 4 h, preceded by increased transcription at 1 h, likely due to activation of RXFP1 and cAMP. When all cell types were treated with IL1B and RLN, RLN augmented secretion of IL6 and IL8 from CyT and DF, but not DSC. Similarly, RLN augmented LPS-induced IL6 secretion from CyT and DF. Despite the structural similarity between TLR4 and RXFP1, blocking TLR4 in CyT had no effect on RLN-induced IL6 secretion, suggesting specific activation of RXFP1. Thus, we have shown that in the presence of a low level of intrauterine inflammation/infection, elevated RLN could act on the CyT and DF to augment the inflammatory response, contributing to the pathophysiology of PTB.

Epidermodysplasia verruciformis (EV) is a rare genodermatosis characterized by increased sensitivity to infection by the β-subtype of human papillomaviruses (β-HPVs), causing persistent, tinea versicolor-like dermal lesions. In a majority of affected individuals, these macular lesions progress to invasive cutaneous squamous cell carcinoma (CSCC) in sun-exposed areas. While mutations in transmembrane channel-like 6 (TMC6 / EVER1) and 8 (TMC8 / EVER2) have been causally linked to EV, their molecular functions are unclear. It is likely that their protective effects involve regulation of the β-HPV life cycle, host keratinocyte apoptosis vs. survival balance and/or T-cell interaction with infected host cells.