Irit Szaingurten-Solodkin

TGF-β signaling through SMAD2/3 induces the quiescent microglial phenotype within the CNS environment

Microglia are myeloid‐derived cells that colonize the central nervous system (CNS) at early stages of development and constitute up to 20% of the glial populations throughout life. While extensive progress has been recently made in identifying the cellular origin of microglia, the mechanism whereby the cells acquire the unique ramified and quiescent phenotype within the CNS milieu remains unknown. Here, we show that upon co‐culturing of either CD117+/Lin− hematopoietic progenitors or CD11c+ bone marrow derived cells with organotypic hippocampal slices or primary glia, the cells acquire a ramified morphology concomitant with reduced levels of CD86, MHCII, and CD11c and up‐regulation of the microglial cell–surface proteins CX3CR1 and Iba‐1. We further demonstrate that the transforming growth factor beta (TGF‐β) signaling pathway via SMAD2/3 phosphorylation is essential for both primary microglia and myeloid‐derived cells in order to acquire their quiescent phenotype. Our study suggests that the abundant expression of TGF‐β within the CNS during development and various inflammatory processes plays a key role in promoting the quiescent phenotype of microglia and may thus serve as a target for therapeutic strategies aimed at modulating the function of microglia in neurodegenerative diseases such as Alzheimers and prion.

Reduction of cPLA2alpha overexpression: an efficient anti-inflammatory therapy for collagen-induced arthritis.

Cytosolic phospholipase A2α (cPLA2) plays an important role in the development of several inflammatory diseases. The aim of the present study is to determine whether inhibition of cPLA2 expression, using specific antisense oligonucleotides against cPLA2 (antisense), is efficient in reducing inflammation after its development. Two mouse models of inflammation were included in the study: thioglicolate peritonitis and collagen‐induced arthritis (CIA). The antisense was found to be specific and efficient in inhibiting cPLA2 expression and NADPH oxidase activity ex vivo in peritoneal phagocytes. Immunoblotting and immunohistochemistry analysis showed a significant elevation in cPLA2 expression in the inflamed joints of collagen‐induced arthritis mice localized in cell infiltrate, chondrocytes and the surrounding skin and skeletal muscle. Similarly, the cPLA2 metabolite, leukotriene B4, accumulated in the peritoneal cavity of mice with peritonitis. Inhibition of elevated cPLA2 expression after development of inflammation by intravenous administration of antisense resulted in a dramatic reduction in inflammation and a significant reduction in neutrophils recruitment to the site of inflammation in both mouse models of inflammation. Our results demonstrate the critical role of cPLA2 for the duration of inflammation and suggest that inhibition of cPLA2 expression by antisense oligonucleotides may serve as an efficient treatment of inflammatory diseases.

Regulatory role of cytosolic phospholipase A2α in NADPH oxidase activity and in inducible nitric oxide synthase induction by aggregated Aβ1–42 in microglia

In Alzheimers disease, extracellular deposits of amyloid β1–42 (Aβ1–42) may induce activation of microglial cells by releasing proinflammatory factors that contribute to the neurodegeneration process. Since the activation of cytosolic phospholipase A2α (cPLA2α) has been reported in inflammatory conditions, its role in primary rat microglial cell activated by aggregated Aβ1–42 was elucidated. The results of the present study show that activation of microglia by 5 μM aggregated Aβ1–42 (as evident by the amoeboid morphology and increased CD68 immunofluorescence reactivity) caused an immediate activation of cPLA2α, measured by its phosphorylated form and its specific activity, followed by a gradual elevation of its expression and activity during 24 h. Inhibition of cPLA2α expression and activity by the presence of 1 μM specific antisense resulted in a significant decrease in NADPH oxidase activity that releases superoxides, PGE2 formation, iNOS expression, and NO production, indicating a major role for cPLA2α in the regulation of these inflammatory processes. NADPH oxidase activity, which is under cPLA2α regulation, was found to upregulate cPLA2α and COX‐2 protein expression through the redox‐sensitive NFκB activation as evident by its phosphorylation on Ser‐536, resulting in increased PGE2 formation. The secreted PGE2 induced the synthesis of iNOS and the production of NO through the PKA‐CREB pathway. Taken together, our results suggest that the response of cPLA2α to aggregated Aβ1–42 is probably a key player in the oxidative stress present in AD, regulating potent oxidative agents: the production of superoxides by NADPH oxidase and NO formation by iNOS.

Gestational Diabetes Mellitus Is a Significant Risk Factor for Long-Term Maternal Renal Disease

CONTEXT Gestational diabetes mellitus (GDM) was found to be an independent risk factor for recurrent long-term type 2 diabetes mellitus, cardiovascular morbidity, and vascular endothelial dysfunction. However, data on the link between GDM and future risk for long-term maternal renal disease are limited. OBJECTIVE The purpose of this study was to investigate whether GDM poses a risk for subsequent long-term maternal renal morbidity. DESIGN A population-based noninterventional study compared the incidence of future renal morbidity in a cohort of women with and without previous GDM. Deliveries occurred during a 25-year period, with a mean follow-up duration of 11.2 years. SETTING The study was conducted at the Soroka University Medical Center. PARTICIPANTS The study population was composed of all singleton pregnancies in women who delivered between January 1988 and December 2013. MAIN OUTCOME MEASURE The main outcome was diagnosis of renal morbidities. RESULTS Of 97,968 women who met the inclusion criteria, 9542 (9.7%) had at least 1 previous pregnancy with GDM. Using a Kaplan-Meier survival curve, we show that women with GDM had higher rates of total renal morbidity (0.1% vs 0.2%, for no GDM and with GDM, respectively; odds ratio, 2.3, 95% confidence interval, 1.4-3.7; P < .001). In addition, we found a significant dose-response association (using the χ(2) test for trends) between the number of pregnancies with GDM and future risk for renal morbidity (0.1%, 0.2%, and 0.4% for no GDM, 1 episode of GDM, and 2 episodes of GDM, respectively; P < .001). In a Cox proportional hazards model, adjusted for confounders, GDM was independently associated with future renal morbidity. CONCLUSION GDM is a significant risk factor for future maternal renal morbidity. The risk is more substantial for patients with recurrent episodes of GDM.

The effects of pravastatin on the normal human placenta: Lessons from ex-vivo models.

Introduction Research in animal models and preliminary clinical studies in humans support the use of pravastatin for the prevention of preeclampsia. However, its use during pregnancy is still controversial due to limited data about its effect on the human placenta and fetus. Methods In the present study, human placental cotyledons were perfused in the absence or presence of pravastatin in the maternal reservoir (PraM). In addition, placental explants were treated with pravastatin for 5, 24 and 72 h under normoxia and hypoxia. We monitored the secretion of placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin (sEng), endothelial nitric oxide synthase (eNOS) expression and activation and the fetal vasoconstriction response to angiotensin-II. Results The concentrations of PlGF, sFlt-1 and sEng were not significantly altered by pravastatin in PraM cotyledons and in placental explants compared to control. Under hypoxic conditions, pravastatin decreased sFlt-1 concentrations. eNOS expression was significantly increased in PraM cotyledons but not in pravastatin-treated placental explants cultured under normoxia or hypoxia. eNOS phosphorylation was not significantly affected by pravastatin. The feto-placental vascular tone and the fetal vasoconstriction response to angiotensin-II, did not change following exposure of the maternal circulation to pravastatin. Conclusion We found that pravastatin does not alter the essential physiological functions of the placenta investigated in the study. The relevance of the study lays in the fact that it expands the current knowledge obtained thus far regarding the effect of the drug on the normal human placenta. This data is reassuring and important for clinicians that consider the treatment of high-risk patients with pravastatin, a treatment that exposes some normal pregnancies to the drug.

Gestational diabetes mellitus is a significant risk factor for long-term ophthalmic morbidity

PurposeTo investigate whether patients with a history of gestational diabetes mellitus (GDM) have an increased risk for long-term ophthalmic morbidity.MethodsDesign a population-based study compared the incidence of long-term maternal ophthalmic morbidity in a cohort of women with and without a history of GDM. Setting Soroka University Medical Center. Participants: All singleton pregnancies of women who delivered between 1988 and 2013. Main outcome measure(s) Diagnosis of ophthalmic morbidity. Analyses A Kaplan–Meier survival curve was used to estimate cumulative incidence of ophthalmic morbidity. Cox proportional hazards models were used to estimate the adjusted hazard ratios (HR) for ophthalmic morbidity.ResultsDuring the study period, 104,751 deliveries met the inclusion criteria; 9.4% (n = 9888) of which occurred in patients with a diagnosis of GDM during at least one of their pregnancies. Patients with GDM had a significantly higher incidence of ophthalmic morbidity such as glaucoma, diabetic retinopathy, and retinal detachment compared with controls (0.1 vs. 0.02%, p < 0.001; 0.2 vs. 0.04%, p < 0.001; 0.2 vs. 0.1%, p < 0.001, respectively). Patients with concurrent GDM and preeclampsia had a significantly higher incidence of total ophthalmic complications compared to patients with GDM only (1 vs. 0.6%, respectively, p < 0.001). Using Kaplan–Meier survival curve, patients with a previous diagnosis of GDM had significantly higher cumulative incidence of ophthalmic morbidity (p < 0.001, log-rank test). In the Cox proportional hazards model, a history of GDM remained independently associated with ophthalmic morbidity (adjusted HR 2.0; 95% CI 1.5–2.8; p < 0.001).ConclusionsGDM is an independent risk factor for long-term maternal ophthalmic morbidity.

Preeclampsia and Future Risk for Maternal Ophthalmic Complications

Objective To investigate whether patients with a history of preeclampsia have an increased risk of long-term ophthalmic complications. Study Design A population-based study comparing the incidence of long-term maternal ophthalmic complications in a cohort of women with and without a history of preeclampsia. Results During the study period, a total of 103,183 deliveries met the inclusion criteria; 8.1% (n = 8,324) occurred in patients with a diagnosis of preeclampsia during at least one of their pregnancies. Patients with preeclampsia had a significantly higher incidence of long-term ophthalmic morbidity such as diabetic retinopathy and retinal detachment. In addition, a positive linear correlation was found between the severity of preeclampsia and the prevalence of future ophthalmic morbidities (0.3 vs. 0.5 vs. 2.2%, respectively). Kaplan-Meier survival curve indicated that women with preeclampsia had higher rates of total ophthalmic morbidity (0.2 vs. 0.4%, for no preeclampsia and with preeclampsia, respectively; odds ratio = 2.06, 95% confidence interval: 1.42-2.99; p < 0.001). In a Cox proportional hazards model, adjusted for confounders, a history of preeclampsia remained independently associated with ophthalmic complications. Conclusion Preeclampsia is an independent risk factor for long-term maternal ophthalmic morbidity, specifically diabetic retinopathy and retinal detachment. This risk is more substantial depending on the severity of the disease.

Obesity during pregnancy and long-term risk for ophthalmic morbidity – a population-based study with a follow-up of more than a decade

Abstract Objective: To investigate whether patients with a history of obesity during pregnancy have an increased risk for subsequent long-term ophthalmic complications, after controlling for diabetes and preeclampsia. Methods: A population-based study compared the incidence of long-term maternal ophthalmic complications in a cohort of women with and without a history of obesity during pregnancy. Deliveries occurred between the years 1988 and 2013, with a mean follow-up duration of 12 years. Results: During the study period 106 220 deliveries met the inclusion criteria; 2.2% (n = 2353) occurred in patients with a diagnosis of obesity during at least one of their pregnancies. These patients had a significantly higher incidence of ophthalmic complications in total and specifically of diabetic retinopathy. Using a Kaplan–Meier survival curve, we found that patients with a history of obesity during pregnancy had a significantly higher cumulative incidence of ophthalmic complications. Using a Cox proportional hazards model, adjusted for confounders such as maternal age, preeclampsia and diabetes mellitus, we found obesity during pregnancy remained independently associated with ophthalmic complications (adjusted HR, 2.4; 95% CI, 1.4–4.2; p = 0.003). Conclusion: Obesity during pregnancy is an independent risk factor for long-term ophthalmic complications, and specifically diabetic retinopathy.

Detection of S100B in maternal blood before and after fetal death

S100B is a brain damage biomarker. When measured immediately after birth, it reflects neonatal brain damage following asphyxia. In this study, we used feticide as a novel model of fetal brain damage. We examined whether such damage is reflected by a rise in S100B in maternal blood before delivery.