The Role of Insulin-like Growth Factor-Axis and Mitotic Index in South Indian Neonates with Small for Gestational Age

Abstract

Objective

IGF-axis and mitotic capacity of cells play a vital role in fetal growth. We compared IGF1, IGF2, and IGFBP3 protein levels, mitotic indices, IGFR1 and IGFR2 mRNA expression in appropriate for gestational age (AGA) and small for gestational age (SGA) neonates of Indian women.

Methods

Cord blood (n = 80) and placental samples (n = 40) were collected from AGA and SGA neonates. Plasma IGF1, IGF2, and IGFBP3 proteins were measured by ELISA. IGFR1 and IGFR2 mRNA expression in the placenta were analyzed by qRT-PCR. Cord blood was cultured in vitro and mitotic index was obtained.

Results

IGF1 (p = 1), and IGF2 (p = 0.69) protein levels did not differ, whereas IGFBP3 (p = 0.02) was significantly less in SGA compared to AGA neonates. Down-regulation of IGFR1 (3.9-folds) and IGFR2 (2.8-folds) mRNA and reduced mitotic index of lymphocytes was observed in SGA (p = 0.001) compared to AGA neonates.

Conclusion

Our results showed that, SGA neonates displayed down-regulated IGFR1 and IGFR2 mRNA, decreased IGFBP3 protein and mitotic index.

Keywords:

• Appropriate for Gestational age
• Insulin-like growth factor
• Mitotic index
• Small for gestational age
• Umbilical cord blood

Acknowledgments

We acknowledge the nursing staff Ms. Manjula and Ms. Mala, Department of Obstetrics and Gynaecology, RLJH, Kolar, Karnataka, India, who helped to collect the samples.

Disclosure statement

The authors declared that there are no conflicts of interest.

Additional information

Funding

The study received infrastructure support from Sri Devaraj Urs Academy of Higher Education and Research (Deemed to be a University), Kolar-563 103, Karnataka, India.