Regulatory T cells are paramount effectors in progesterone regulation of embryo implantation and fetal growth

Published: June 8, 2023Progesterone (P4) is essential for embryo implantation, but the extent to which the pro-gestational effects of P4 depend on the maternal immune compartment is unknown. Here, we investigate whether regulatory T cells (Treg cells) act to mediate luteal phase P4 effects on uterine receptivity in mice. P4 antagonist RU486 administered to mice on days 0.5 and 2.5 post coitum (dpc) to model luteal phase P4 deficiency caused fewer CD4+Foxp3+ Treg cells and impaired Treg functional competence, along with dysfunctional uterine vascular remodeling and perturbed placental development in mid-gestation. These effects were linked with fetal loss and fetal growth restriction, accompanied by a Th1/CD8-skewed T cell profile. Adoptive transfer at implantation of Treg cells - but not T conventional (Tconv) cells - alleviated fetal loss and fetal growth restriction by mitigating adverse effects of reduced P4 signaling on uterine blood vessel remodeling and placental structure, and restoring maternal T cell imbalance. These findings demonstrate an essential role for Treg cells in mediating P4 effects at implantation, and indicate that Treg cells are a sensitive and critical effector mechanism through which P4 drives uterine receptivity to support robust placental development and fetal growth.Ella S. Green, Lachlan M. Moldenhauer, Holly M. Groome, David J. Sharkey, Peck Y. Chin, Alison S. Care, Rebecca L. Robker, Shaun R. McColl, and Sarah A., Robertso

Radiotherapy exposure directly damages the uterus and causes pregnancy loss

Female cancer survivors are significantly more likely to experience infertility than the general population. It is well established that chemotherapy and radiotherapy can damage the ovary and compromise fertility, yet the ability of cancer treatments to induce uterine damage, and the underlying mechanisms, have been understudied. Here, we show that in mice total-body γ-irradiation (TBI) induced extensive DNA damage and apoptosis in uterine cells. We then transferred healthy donor embryos into ovariectomized adolescent female mice that were previously exposed to TBI to study the impacts of radiotherapy on the uterus independent from effects to ovarian endocrine function. Following TBI, embryo attachment and implantation were unaffected, but fetal resorption was evident at midgestation in 100% of dams, suggesting failed placental development. Consistent with this hypothesis, TBI impaired the decidual response in mice and primary human endometrial stromal cells. TBI also caused uterine artery endothelial dysfunction, likely preventing adequate blood vessel remodeling in early pregnancy. Notably, when pro-apoptotic protein Puma-deficient (Puma–/–) mice were exposed to TBI, apoptosis within the uterus was prevented, and decidualization, vascular function, and pregnancy were restored, identifying PUMA-mediated apoptosis as a key mechanism. Collectively, these data show that TBI damages the uterus and compromises pregnancy success, suggesting that optimal fertility preservation during radiotherapy may require protection of both the ovaries and uterus. In this regard, inhibition of PUMA may represent a potential fertility preservation strategy.Meaghan J. Griffiths, Sarah A. Marshall, Fiona L. Cousins, Lauren R. Alesi, Jordan Higgins, Saranya Giridharan, Urooza C. Sarma, Ellen Menkhorst, Wei Zhou, Alison S. Care, Jacqueline F. Donoghue, Sarah J. Holdsworth-Carson, Peter A.W. Rogers, Evdokia Dimitriadis, Caroline E. Gargett, Sarah A. Robertson, Amy L. Winship, and Karla J. Hut

Developing core elements and checklist items for global hospital antimicrobial stewardship programmes:a consensus approach

International audienc

Respiratory Self-Care:Identifying Current Challenges and Future Potentials for Digital Technology to Support People with Chronic Respiratory Conditions

Chronic respiratory conditions (CRCs) are life-long diseases affecting millions of people worldwide. They have a huge impact on individuals’ everyday lives, resulting in a number of physical and emotional challenges. Self-management interventions for CRCs are thought to provide empowerment and improve quality of life. However, despite the number of people living with CRCs, most self-management tools in previous HCI work have been designed without the insight of those affected by the conditions. In this paper, we contribute to the literature by investigating the experiences and everyday challenges faced by those with CRCs, through the involvement of 156 participants via interviews and an anonymous survey. Our findings reveal the self-care challenges of CRCs and the reactive management approaches taken by participants. We conclude by providing a set of design implications that support the design of future self-management tools for CRCs

Mechanisms of uterine artery dysfunction in pregnancy complications

Pregnancy is a unique condition, and the vascular processes that are required for this undertaking are both complex and extensive. In this review, we discuss the vascular adaptations which occur in the maternal uterine arterial bed to maintain blood supply to the fetal-placental unit. In complicated pregnancies, inadequate remodeling of the uterine arteries, hormonal imbalances, and pre-existing conditions such as obesity, hypertension, diabetes etc. may lead to maladaptations of the uterine vasculature that includes increased vasoconstriction and endothelial dysfunction. Ultimately, uterine artery dysfunction results in increased vascular resistance impeding blood flow to the fetal-placental unit and limiting fetal growth and development. A strong association exists between poor fetal development in utero and later life health issues, which can include obesity, poor neurological development, and enhanced susceptibility to cardiovascular disease. Therefore, the detrimental outcomes of a complicated pregnancy are far-reaching and significantly impact the health of the population as a whole. Many treatment options to improve maternal uterine artery function and ameliorate the impact on the fetus are being considered. A particular difficulty in treating complicated pregnancies is the presence of not 1 but (at least) 2 patients. Novel approaches are required to successfully improve pregnancy outcomes and minimize the impact on later life health.Jude S. Morton, Alison S. Care, and Sandra T. Davidg

Macrophages are essential for maintenance of corpus luteum function in early pregnancy

Abstract no. 158Alison S. Care , Melinda J. Jasper , Wendy V. Ingman , and Sarah A. Robertso

Immune determinants of endometrial receptivity: a biological perspective

Abstract not availableSarah A.Robertson Ph.D., Lachlan M.Moldenhauer, Ph.D, .Ella S.Green, Ph.D., Alison S.Care, Ph.D., M. Louise Hull M.B.Ch.B., Ph.D

Reduction in regulatory T cells in early pregnancy causes uterine artery dysfunction in mice

Preeclampsia, fetal growth restriction, and miscarriage remain important causes of maternal and perinatal morbidity and mortality. These complications are associated with reduced numbers of a specialized T lymphocyte subset called regulatory T cells (Treg cells) in the maternal circulation, decidua, and placenta. Treg cells suppress inflammation and prevent maternal immunity toward the fetus, which expresses foreign paternal alloantigens. Treg cells are demonstrated to contribute to vascular homeostasis, but whether Treg cells influence the vascular adaptations essential for a healthy pregnancy is unknown. Thus, using a mouse model of Treg-cell depletion, we investigated the hypothesis that depletion of Treg cells would cause increased inflammation and aberrant uterine artery function. Here, we show that Treg-cell depletion resulted in increased embryo resorption and increased production of proinflammatory cytokines. Mean arterial pressure exhibited greater modulation by NO in Treg cell-deficient mice because the L-NG-nitroarginine methyl ester-induced increase in mean arterial pressure was 46% greater compared with Treg cell-replete mice. Uterine artery function, which is essential for the supply of nutrients to the placenta and fetus, demonstrated dysregulated hemodynamics after Treg-cell depletion. This was evidenced by increased uterine artery resistance and pulsatility indices and enhanced conversion of bET-1 (big endothelin-1) to the active and potent vasoconstrictor, ET-1 (endothelin-1). These data demonstrate an essential role for Treg cells in modulating uterine artery function during pregnancy and implicate Treg-cell control of maternal vascular function as a key mechanism underlying normal fetal and placental development.Alison S. Care, Stephane L. Bourque, Jude S. Morton, Emma P. Hjartarson, Sarah A. Robertson and Sandra T. Davidg

Increased susceptibility to cardiovascular disease in offspring born from dams of advanced maternal age

Poster - T-177Christy-Lynn M Cooke, Alison S Care, Jude S Morton, Amin Shah, Laura M Reyes, Sandra T Davidg

Perinatal resveratrol supplementation to spontaneously hypertensive rat dams mitigates the development of hypertension in adult offspring

This study was undertaken to determine whether perinatal maternal resveratrol (Resv)--a phytoalexin known to confer cardiovascular protection--could prevent the development of hypertension and improve vascular function in adult spontaneously hypertensive rat offspring. Dams were fed either a control or Resv-supplemented diet (4 g/kg diet) from gestational day 0.5 until postnatal day 21. Indwelling catheters were used to assess blood pressure and vascular function in vivo; wire myography was used to assess vascular reactivity ex vivo. Perinatal Resv supplementation in dams had no effect on fetal body weights, albeit continued maternal treatment postnatally resulted in growth restriction in offspring by postnatal day 21; growth restriction was no longer evident after 5 weeks of age. Maternal perinatal Resv supplementation prevented the onset of hypertension in adult offspring (-18 mm Hg; P=0.007), and nitric oxide synthase inhibition (with L-NG-nitroarginine methyl ester) normalized these blood pressure differences, suggesting improved nitric oxide bioavailability underlies the hemodynamic alterations in the Resv-treated offspring. In vivo and ex vivo, vascular responses to methylcholine were not different between treatment groups, but prior treatment with L-NG-nitroarginine methyl ester attenuated the vasodilation in untreated, but not Resv-treated adult offspring, suggesting a shift toward nitric oxide-independent vascular control mechanisms in the treated group. Finally, bioconversion of the inactive precursor big endothelin-1 to active endothelin-1 in isolated mesenteric arteries was reduced in Resv-treated offspring (-28%; P<0.05), and this difference could be normalized by L-NG-nitroarginine methyl ester treatment. In conclusion, perinatal maternal Resv supplementation mitigated the development of hypertension and causes persistent alterations in vascular responsiveness in spontaneously hypertensive rats.Alison S. Care, Miranda M. Sung, Sareh Panahi, Ferrante S. Gragasin, Jason R.B. Dyck, Sandra T. Davidge and Stephane L. Bourqu