RNA interference therapeutics targeting angiotensinogen ameliorate preeclamptic phenotype in rodent models

Preeclampsia, with the hallmark features of new-onset hypertension and proteinuria after 20 weeks of gestation, is a major cause of fetal and maternal morbidity and mortality. Studies have demonstrated a role for the renin-angiotensin system (RAS) in its pathogenesis; however, small-molecule RAS blockers are contraindicated because of fetal toxicity. We evaluated whether siRNA targeting maternal hepatic angiotensinogen (Agt) could ameliorate symptoms of preeclampsia without adverse placental or fetal effects in 2 rodent models. The first model used a cross of females expressing human Agt with males expressing human renin, resulting in upregulation of the circulating and uteroplacental RAS. The second model induced ischemia/reperfusion injury and subsequent local and systemic inflammation by surgically reducing placental blood flow midgestation (reduced uterine perfusion pressure [RUPP]). These models featured hypertension, proteinuria, and fetal growth restriction, with altered biomarkers. siRNA treatment ameliorated the preeclamptic phenotype in both models, reduced blood pressure, and improved intrauterine growth restriction, with no observed deleterious effects on the fetus. Treatment also improved the angiogenic balance and proteinuria in the transgenic model, and it reduced angiotensin receptor activating antibodies in both. Thus, an RNAi therapeutic targeting Agt ameliorated the clinical sequelae and improved fetal outcomes in 2 rodent models of preeclampsia

Crucial Role for BAFF-BAFF-R Signaling in the Survival and Maintenance of Mature B Cells

Defects in the expression of either BAFF (B cell activating factor) or BAFF-R impairs B cell development beyond the immature, transitional type-1 stage and thus, prevents the formation of follicular and marginal zone B cells, whereas B-1 B cells remain unaffected. The expression of BAFF-R on all mature B cells might suggest a role for BAFF-R signaling also for their in vivo maintenance. Here, we show that, 14 days following a single injection of an anti-BAFF-R mAb that prevents BAFF binding, both follicular and marginal zone B cell numbers are drastically reduced, whereas B-1 cells are not affected. Injection of control, isotype-matched but non-blocking anti-BAFF-R mAbs does not result in B cell depletion. We also show that this depletion is neither due to antibody-dependent cellular cytotoxicity nor to complement-mediated lysis. Moreover, prevention of BAFF binding leads to a decrease in the size of the B cell follicles, an impairment of a T cell dependent humoral immune response and a reduction in the formation of memory B cells. Collectively, these results establish a central role for BAFF-BAFF-R signaling in the in vivo survival and maintenance of both follicular and marginal zone B cell pools

Governing shipping externalities : Baltic ports in the process of SOx emission reduction

This paper analyses the debate which has unfolded in the Baltic Sea Region regarding the reduction of sulphur content in vessel fuels, in order to illustrate how tightening environmental regulation challenges traditional forms of maritime governance. Using an interactive governance approach, this study reconstructs the process of sulphur emission reduction as a complex multi-stakeholder interaction in multiple contexts. The empirical investigation has drawn on documentary material from around the Baltic region, including Russia, and has applied the method of qualitative content analysis. The empirical study focuses on two interlinked questions: (1) How sulphur emission reduction policies are being anticipated by maritime industry, in particular by Baltic ports and (2) How port adaptation strategies are tied into Baltic local and energy contexts. Addressing these questions highlights the role of polycentricity in shipping governance and explains how the same universal international regulations can produce varying patterns of governance. The paper concludes that policy-making shall take an account of the fact that the globalized shipping industry is nevertheless locally and sectorally embedded.Peer reviewe

Cracking the BAFF code.

The tumour necrosis factor (TNF) family members B cell activating factor (BAFF) and APRIL (a proliferation-inducing ligand) are crucial survival factors for peripheral B cells. An excess of BAFF leads to the development of autoimmune disorders in animal models, and high levels of BAFF have been detected in the serum of patients with various autoimmune conditions. In this Review, we consider the possibility that in mice autoimmunity induced by BAFF is linked to T cell-independent B cell activation rather than to a severe breakdown of B cell tolerance. We also outline the mechanisms of BAFF signalling, the impact of ligand oligomerization on receptor activation and the progress of BAFF-depleting agents in the clinical setting

Intestinal bacteria condition dendritic cells to promote IgA production

Immunoglobulin (Ig) A represents the predominant antibody isotype produced at the intestinal mucosa, where it plays an important role in limiting the penetration of commensal intestinal bacteria and opportunistic pathogens. We show in mice that Peyer's Patch-derived dendritic cells (PP-DC) exhibit a specialized phenotype allowing the promotion of IgA production by B2 cells. This phenotype included increased expression of the retinaldehyde dehydrogenase 1 (RALDH1), inducible nitric oxide synthase (iNOS), B cell activating factor of the tumor necrosis family (BAFF), a proliferation-inducing ligand (APRIL), and receptors for the neuropeptide vasoactive intestinal peptide (VIP). The ability of PP-DC to promote anti-CD40 dependent IgA was partially dependent on retinoic acid (RA) and transforming growth factor (TGF)-beta, whilst BAFF and APRIL signaling were not required. Signals delivered by BAFF and APRIL were crucial for CD40 independent IgA production, although the contribution of B2 cells to this pathway was minimal. The unique ability of PP-DC to instruct naïve B cells to differentiate into IgA producing plasma cells was mainly imparted by the presence of intestinal commensal bacteria, and could be mimicked by the addition of LPS to the culture. These data indicate that exposure to pathogen-associated molecular patterns present on intestinal commensal bacteria condition DC to express a unique molecular footprint that in turn allows them to promote IgA production

RNAi-mediated rheostat for dynamic control of AAV-delivered transgenes

Here the authors propose an RNA interference-based switch for dynamic control of AAV transgene expression. In this approach, transgene expression may be silenced by RNAi and subsequently recovered using REVERSIR oligonucleotides