RNAi modulation of placental sFLT1 for the treatment of preeclampsia

Preeclampsia is a placentally induced hypertensive disorder of pregnancy that is associated with substantial morbidity and mortality to mothers and fetuses. Clinical manifestations of preterm preeclampsia result from excess circulating soluble vascular endothelial growth factor receptor FLT1 (sFLT1 or sVEGFR1) of placental origin. Here we identify short interfering RNAs (siRNAs) that selectively silence the three sFLT1 mRNA isoforms primarily responsible for placental overexpression of sFLT1 without reducing levels of full-length FLT1 mRNA. Full chemical stabilization in the context of hydrophobic modifications enabled productive siRNA accumulation in the placenta (up to 7% of injected dose) and reduced circulating sFLT1 in pregnant mice (up to 50%). In a baboon preeclampsia model, a single dose of siRNAs suppressed sFLT1 overexpression and clinical signs of preeclampsia. Our results demonstrate RNAi-based extrahepatic modulation of gene expression with nonformulated siRNAs in nonhuman primates and establish a path toward a new treatment paradigm for patients with preterm preeclampsia.

Increased salt sensitivity in offspring of pregnancies complicated by experimental preeclampsia

Preeclampsia is a hypertensive disorder of pregnancy known to increase the risk of cardiovascular disease in mothers and offspring. Offspring exposed to a suboptimal intrauterine environment may experience altered fetal programming and subsequent long-term cardiovascular changes. This study investigated changes in the vascular response in offspring from experimental preeclampsia (EPE) induced by uterine artery ligation, in the absence of fetal growth restriction, compared to normal baboon pregnancies (controls), following a high salt diet challenge. After 1 week of standard diet (containing <1% salt), animals were fed a high salt diet (6%) for 2 weeks. Systolic and diastolic blood pressure (SBP, DBP), aldosterone, renin and creatinine clearance were evaluated in EPE (n = 6, 50% male) and control (n = 6, 50% male) offspring. A repeated measures analysis was performed, and P < 0.05 was considered significant. At baseline, there were no differences between the groups in any parameter (EPE, mean age and weight 3.2 ± 1.2 years, 6.8 ± 1.0 kg, respectively; Control, 2.9 ± 0.8 years, 7.1 ± 1.5 kg). After salt loading the EPE group had significantly higher SBP (92 ± 5 mm Hg) compared to the control group (83 ± 4 mm Hg, P = 0.03). Aldosterone concentration was higher in the EPE group despite the same salt excretion and no difference in renal function. Salt sensitivity may differ in offspring from hypertensive pregnancies due to fetal programming. This could have long-term consequences for cardiovascular health of EPE offspring and further research is required to determine the exact pathological mechanisms.

CD83 is a new potential biomarker and therapeutic target for Hodgkin lymphoma

Chemotherapy and hematopoietic stem cell transplantation are effective treatments for most Hodgkin lymphoma patients, however there remains a need for better tumor-specific target therapy in Hodgkin lymphoma patients with refractory or relapsed disease. Herein, we demonstrate that membrane CD83 is a diagnostic and therapeutic target, highly expressed in Hodgkin lymphoma cell lines and Hodgkin and Reed-Sternberg cells in 29/35 (82.9%) Hodgkin lymphoma patient lymph node biopsies. CD83 from Hodgkin lymphoma tumor cells was able to trogocytose to surrounding T cells and, interestingly, the trogocytosing CD83+T cells expressed significantly more programmed death-1 compared to CD83-T cells. Hodgkin lymphoma tumor cells secreted soluble CD83 that inhibited T-cell proliferation, and anti-CD83 antibody partially reversed the inhibitory effect. High levels of soluble CD83 were detected in Hodgkin lymphoma patient sera, which returned to normal in patients who had good clinical responses to chemotherapy confirmed by positron emission tomography scans. We generated a human anti-human CD83 antibody, 3C12C, and its toxin monomethyl auristatin E conjugate, that killed CD83 positive Hodgkin lymphoma cells but not CD83 negative cells. The 3C12C antibody was tested in dose escalation studies in non-human primates. No toxicity was observed, but there was evidence of CD83 positive target cell depletion. These data establish CD83 as a potential biomarker and therapeutic target in Hodgkin lymphoma.

A Cross-Sectional Study of Ageing and Cardiovascular Function over the Baboon Lifespan

Background

Ageing is associated with changes at the molecular and cellular level that can alter cardiovascular function and ultimately lead to disease. The baboon is an ideal model for studying ageing due to the similarities in genetic, anatomical, physiological and biochemical characteristics with humans. The aim of this cross-sectional study was to investigate the changes in cardiovascular profile of baboons over the course of their lifespan.

Methods

Data were collected from 109 healthy baboons (Papio hamadryas) at the Australian National Baboon Colony. A linear regression model, adjusting for sex, was used to analyse the association between age and markers of ageing with P < 0.01 considered significant.

Results

Male (n = 49, 1.5–28.5 years) and female (n = 60, 1.8–24.6 years) baboons were included in the study. Age was significantly correlated with systolic (R² = 0.23, P < 0.001) and diastolic blood pressure (R² = 0.44, P < 0.001), with blood pressure increasing with age. Age was also highly correlated with core augmentation index (R² = 0.17, P < 0.001) and core pulse pressure (R² = 0.30, P < 0.001). Creatinine and urea were significantly higher in older animals compared to young animals (P < 0.001 for both). Older animals (>12 years) had significantly shorter telomeres when compared to younger (<3 years) baboons (P = 0.001).

Conclusion

This study is the first to demonstrate that cardiovascular function alters with age in the baboon. This research identifies similarities within cardiovascular parameters between humans and baboon even though the length of life differs between the two species.