Investigating the effect of excess caffeine exposure on placental angiogenesis using chicken ’functional‘ placental blood vessel network

Abstract

It is now known that over-consumption of caffeine by pregnant mothers could have detrimental effects on normal fetal development. However, it remains obscure how caffeine's harmful effect impacts directly or indirectly on the developing embryo/fetus through damaging placenta development. In this study, we demonstrated the morphological similarities between the yolk sac and chorioallantoic membranes (CAM) of chick embryos and the villi of the mammalian placenta. Using the chick yolk sac and the CAM as a model, we found that 5-15 µmol per egg of caffeine exposure inhibited angiogenesis. Under the same condition, cell proliferation in extraembryonic mesoderm was reduced while apoptosis was enhanced. Semi-quantitative RT-PCR analysis revealed that caffeine treatment down-regulated VEGF, VEGFR2, PIGF, IGF2 and NRP1 expression, but up-regulated Ang1 and Ang2 expression. We performed in situ hybridization to show VE-cadherin expression and as to demonstrate the blood vessels in the CAM and yolk sac membranes. This distribution of the VE-cadherin(+) blood vessels was determined to be reduced after caffeine treatment. Furthermore, MDA activity was induced after caffeine exposure, but GSH-PX activity was inhibited after caffeine exposure; SOD activity was unchanged as compared with the control. In summary, our results suggest that caffeine exposure could negatively impact on angiogenesis in the chick yolk sac and CAM by targeting angiogenesis-related genes. Some of these genes are also involved in regulating excess ROS generation. The results implied that the negative impact of caffeine on fetal development was partly attributed to impaired placental angiogenesis.

Angiogenesis is repressed by ethanol exposure during chick embryonic development

“…It has been reported that ethanol could easily penetrate the mammalian placenta and causes teratogenicity in young fetuses (Perez et al, 2006). In our previously study, we demonstrated the morphological and gene expression similarities between the yolk sac of chick embryo and the villi of mammalian placenta (Ma et al, 2015). Thus, negative impact of ethanol on the yolk sac of the chick embryo was partly similar with ethanol-impaired placental angiogenesis.…”

“…In this context, the cardiovascular system is the earliest structure to develop in the embryo, so it is the most vulnerable to alcohol insult. In our previously study, we demonstrated the morphological and gene expression similarities between the yolk sac of chick embryo and the villi of mammalian placenta (Ma et al, 2015). Hence, it was important that we investigate the effects of ethanol on angiogenesis using the chick embryo as a model.…”

Lipopolysaccharides (LPS) Induced Angiogenesis During Chicken Embryogenesis is Abolished by Combined ETA/ETB Receptor Blockade

“…The areas occupied by the blood vessel plexus were quantified using an IPP 6.0 image analysis program. The BVD was expressed as the percentage of area occupied by the blood vessel over the whole area under the microscopic field as previously described [8][9][10][11]. Statistical analysis Cellular Physiology and Biochemistry Cellular Physiology and Biochemistry of all the experimental data generated was performed using a SPSS 13.0 statistical package program for Windows.…”

Caffeine Intake during Pregnancy: What Are the Real Evidences?

“…Caffeine intake is negatively associated with gestational changes in animals, such as lower rates of fertilization and embryonic implantation, low birth and placental weight, greater number of stillbirths, increased expression of apoptotic markers and altered placental and bone formation [9,27,[40][41][42][43][44][45][46] ( Table 1).…”

“…Huang and colleagues, [27] by inducing a dose-dependent consumption of 180 mg/kg of caffeine during pregnancy in Wistar rats, observed edematous regions in the endoplasmic reticulum, expansion of the cisterns of the rough endoplasmic reticulum, ribosomes degranulation and heterochromatin condensation in thophoblast cells. It was also observed an increased apoptosis and inhibitions of angiogenesis following exposure to a "chicken functional placenta" by excessive of caffeine intake [46]. The term "chicken functional placenta" was adopted by the authors of that study from the observation of morphological similarity between the yolk sac and the choriallantoic membranes of a bird compared to the villi of a mammalian placenta.…”