Association between the growth arrest-specific 6 (Gas6) gene polymorphism c.834 + 7G>A and preeclampsia

Lung Inflammation Is Associated with Preeclampsia Development in the Rat

Preeclampsia (PE) is an obstetric complication associated with significant health implications for the fetus and mother. Studies have shown a correlation between lung disease development and PE. Gas6 protein is expressed in the lung and placenta, and binds to the AXL Tyrosine kinase receptor. Recently, our laboratory utilized Gas6 to induce preeclamptic-like conditions in rats. Our objective was to determine the role of Gas6/AXL signaling in the maternal lung during PE development. Briefly, pregnant rats were divided into control, Gas6, or Gas6 + R428 (an AXL inhibitor). Immunofluorescence was performed to determine AXL expression. Bronchoalveolar lavage fluid (BALF) was procured for the assessment of inflammatory cell secretion. Western blot was performed to detect signaling molecules and ELISA determined inflammatory cytokines. We observed increased proteinuria and increased blood pressure in Gas6-treated animals. AXL was increased in the lungs of the treated animals and BALF fluid revealed elevated total protein abundance in Gas6 animals. Extracellular-signal regulated kinase (ERK) and protein kinase B (AKT) signaling in the lung appeared to be mediated by Gas6 as well as the secretion of inflammatory cytokines. We conclude that Gas6 signaling is capable of inducing PE and that this is associated with increased lung inflammation.

Dietary Intake and Genetic Background Influence Vitamin Needs during Pregnancy

Numerous approaches demonstrate how nutritional intake can be sufficient to ensure the necessary supply of vitamins. However, it is evident that not all vitamins are contained in all foods, so it is necessary either to combine different food groups or to use a vitamin supplement to be well-fed. During pregnancy, deficiencies are often exacerbated due to increased energy and nutritional demands, causing adverse outcomes in mother and child. Micronutrient supplementation could lead to optimal pregnancy outcomes being essential for proper metabolic activities that are involved in tissue growth and functioning in the developing fetus. In order to establish adequate vitamin supplementation, various conditions should be considered, such as metabolism, nutrition and genetic elements. This review accurately evaluated vitamin requirements and possible toxic effects during pregnancy. Much attention was given to investigate the mechanisms of cell response and risk assessment of practical applications to improve quality of life. Importantly, genetic studies suggest that common allelic variants and polymorphisms may play an important role in vitamin metabolism during pregnancy. Changes in gene expression of different proteins involved in micronutrients’ metabolism may influence the physiological needs of the pregnant woman.

Gas6 drives Zika virus-induced neurological complications in humans and congenital syndrome in immunocompetent mice

Zika virus (ZIKV) has the ability to cross placental and brain barriers, causing congenital malformations in neonates and neurological disorders in adults. However, the pathogenic mechanisms of ZIKV-induced neurological complications in adults and congenital malformations are still not fully understood. Gas6 is a soluble TAM receptor ligand able to promote flavivirus internalization and downregulation of immune responses. Here we demonstrate that there is a correlation between ZIKV neurological complications with higher Gas6 levels and the downregulation of genes associated with anti-viral response, as type I IFN due to Socs1 upregulation. Also, Gas6 gamma-carboxylation is essential for ZIKV invasion and replication in monocytes, the main source of this protein, which was inhibited by warfarin. Conversely, Gas6 facilitates ZIKV replication in adult immunocompetent mice and enabled susceptibility to transplacental infection. Our data indicate that ZIKV promotes the upregulation of its ligand Gas6, which contributes to viral infectivity and drives the development of severe adverse outcomes during ZIKV infection.

Growth arrest-specific protein-6/AXL signaling induces preeclampsia in rats†

Preeclampsia (PE) is a complicated obstetric complication characterized by increased blood pressure, decreased trophoblast invasion, and inflammation. The growth arrest-specific 6 (Gas6) protein is known to induce dynamic cellular responses and is elevated in PE. Gas6 binds to the AXL tyrosine kinase receptor and AXL-mediated signaling is implicated in proliferation and migration observed in several tissues. Our laboratory utilized Gas6 to induce preeclamptic-like conditions in pregnant rats. Our objective was to determine the role of Gas6/AXL signaling as a possible model of PE. Briefly, pregnant rats were divided into three groups that received daily intraperitoneal injections (from gestational day 7.5 to 17.5) of phosphate buffered saline (PBS), Gas6, or Gas6 + R428 (an AXL inhibitor administered from gestational day 13.5 to 17.5). Animals dispensed Gas6 experienced elevated blood pressure, increased proteinuria, augmented caspase-3-mediated placental apoptosis, and diminished trophoblast invasion. Gas6 also enhanced expression of several PE-related genes and a number of inflammatory mediators. Gas6 further enhanced placental oxidative stress and impaired mitochondrial respiration. Each of these PE-related characteristics was ameliorated in dams and/or their placentae when AXL inhibition by R428 occurred in tandem with Gas6 treatment. We conclude that Gas6 signaling is capable of inducing PE and that inhibition of AXL prevents disease progression in pregnant rats. These results provide insight into pathways associated with PE that could be useful in the clarification of potential therapeutic approaches.

Association study between GAS6 gene polymorphisms and risk of preeclampsia in Chinese population

CONTEXT AND OBJECTIVE

Preeclampsia is a pregnancy-specific disorder associated with pro-inflammatory and pro-thrombotic events. The growth arrest-specific 6 (GAS6) has been implicated in systemic inflammation and coagulation. Common genetic polymorphisms of GAS6 gene have previously been reported. The aim of this study was to investigate the association of GAS6 gene polymorphisms with the risk of preeclampsia in Chinese subjects.

STUDY DESIGN

The case-control population consists of 551 subjects. The genotyping of the single-nucleotide polymorphisms of GAS6 gene, GAS6 834 +7G/A(rs8191974) and +1332C/T (rs1803628), was carried out on genomic DNA using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) analysis.

RESULTS

There were significant differences in the +1332C/T genotype and allele frequencies between the patients with preeclampsia and the controls (P=0.03 and 0.02, respectively). The +1332 TT genotype was found to be protective from the development of preeclampsia (odds ratios 0.271, 95% confidence interval 0.077-0.953; P=0.03). Further analysis showed that the TT genotype of the GAS6 +1332C/T conferred a risk of severe preeclampsia (OR=0.597, 95% confidence interval 0.416-0.855; P=0.01). However, there were no differences in the 834+7G/A genotype and allele frequencies between the patients with preeclampsia and the controls.

CONCLUSION

Our data suggest that a TT genotype at +1332C/T polymorphism might be associated with decreased risk for preeclampsia, but the 834+7G/A polymorphism is not associated with the disorder, in the Chinese population.