The effect of Klotho protein on biological behavior of JEG-3 cells

Objective: The Klotho protein is associated with various aging-related diseases. Previous studies have shown that Klotho expression is reduced in placental and cord blood samples from growth-restricted fetuses, but the underlying mechanisms affecting fetal development remain unclear. This study investigates the effects of Klotho protein on the human placental choriocarcinoma cell line (JEG-3) and explores the mechanisms involved.

Methods: The JEG-3 cell line, which retains characteristics of trophoblast cells, is widely used to study pregnancy-related pathologies. Placental trophoblast cells act as "multifunctional hubs" at the maternal-fetal interface, performing transportation, endocrine regulation, and immune modulation. The GH/IGF-1 pathway plays a crucial role in embryonic growth and immune tolerance, and its abnormal activation is linked to preeclampsia and fetal growth restriction. To investigate the impacts of Klotho protein on the functional characteristics of JEG-3 cells, we designed two experimental setups concentrating on the low expression and high expression of Klotho protein. The research examined the expression levels of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) in JEG-3 cells, along with changes in multiple cellular functions, under these two experimental conditions.

Results: qPCR and flow cytometry analyses showed that in the Klotho low - expression (KL -) tests, the levels of IGF - 1 mRNA in the KL - group were significantly elevated (P < 0.01, P < 0.05), while the levels of GH mRNA were significantly reduced (P < 0.001, P < 0.0001). The cell scratch test demonstrated that the cell migration capacity in the KL - group was improved (P < 0.05). The Cell Counting Kit - 8 (CCK8) test verified an increase in cell viability (P < 0.0001). Reactive Oxygen Species (ROS) detection showed a significant rise in ROS levels (P < < 0.001). The glucose uptake experiment indicated a decrease in glucose uptake in the KL - group (P < 0.0001). The human recombinant Klotho protein was over - expressed in the JEG - 3 cell line. Quantitative polymerase chain reaction (qPCR) and flow cytometry analyses disclosed that in the rKL + group, the levels of IGF - 1 were lowered and the levels of GH were raised (P < 0.05, P < 0.05). The cell scratch test showed that the cell migration rate in the rKL + group was diminished (P < 0.01). The CCK8 test confirmed a decrease in cell viability (P < 0.0001). The ROS detection indicated a significant decrease in ROS levels (P < 0.05). The glucose uptake experiment showed a increase in glucose uptake (P < 0.0001).

Conclusions: Klotho protein affects the expression of GH and IGF-1 in JEG-3 cells, leading to the dysfunction of GH/IGF-1 axis, which subsequently impacts the proliferation, migration, anti-inflammatory response, and glucose metabolism of placental trophoblast cells, ultimately affecting placental function and fetal intrauterine development.

Summary sentence: Reduced Klotho protein expression in JEG-3 cells leads to increased IGF-1, decreased GH, enhanced cell proliferation and migration, elevated inflammatory responses, and metabolic imbalances, potentially contributing to placental dysfunction in growth-restricted fetuses.

Cell experiments; Growth hormone; Human placental choriocarcinoma cells; Insulin-like growth factor-1; Klotho protein.