LC-MS/MS analysis provides new insights into early childhood health and development

By Dr. Chinta SidharthanReviewed by Lily Ramsey, LLMMay 30 2024

Type 1 diabetes is one of the most common endocrine disorders among the pediatric population. It is an autoimmune disease where the immune system destroys the pancreatic β-cells and no longer produces enough insulin.

In a recent study published in iScience, researchers examined the impact of a hydrolyzed formula dietary intervention on β-cell autoimmunity development.

They conducted proteomic analyses of serum samples from mother-infant dyads to determine associations between maternal proteomic changes and type 1 diabetes in infants.

​​​​​​​Study: Serum proteomics of mother-infant dyads carrying HLA-conferred type 1 diabetes risk. Image Credit: SeventyFour/Shutterstock.com

Background

Type 1 diabetes is a common pediatric endocrine disorder caused by the destruction of the insulin-producing pancreatic β-cells found in the islets of Langerhans.

The alleles found at the human leukocyte antigen (HLA) loci DQB1 and DRB1 determine the susceptibility to type 1 diabetes. The increase in the incidence rates of type 1 diabetes has intensified the focus on the prediction, prevention, and early treatment of the disease.

Given that the priming of the infant’s immune system begins in utero and continues during infancy, understanding the biochemical changes that occur in the fetal stages and during the early developmental stages can help understand the underlying mechanisms and pathologies of type 1 diabetes.

Apart from establishing predictive biomarkers, dietary interventions to prevent the onset and progression of the disease have also been explored in various studies.

About the study

In the present study, the researchers compared the impact of a hydrolyzed formula dietary intervention with that of formula based on regular cow’s milk among infants with type 1 diabetes susceptibility based on the HLA-DQB1 and DRB1 alleles.

Additionally, they conducted proteomic analyses of serum samples obtained from mother-infant dyads to understand maternal proteome changes and their associations with type 1 diabetes in the infant.

The risk groups based on the HLA loci were selected by screening parents for HLA-defined type 1 diabetes risk through genotyping. The type 1 diabetes risk of the infant was assessed through cord blood genotyping.

Serum samples from the mothers were collected when the third trimester began, at delivery, and three months postpartum. In contrast, cord blood samples were obtained at birth, and serum samples of the infants were subsequently collected every three months for a year.

These samples included 12 from the group receiving the hydrolyzed casein-based formula and ten from the group receiving the regular cow’s milk-based formula.

These serum samples and 40 additional samples collected from infants from both dietary intervention groups at nine months of age were subjected to liquid chromatography, mass spectrometry, and proteomic analyses.

The relative abundance of various targets including gamma-glutamyl hydrolase (GGH), paraoxonase 3 (PON3), peptidoglycan recognition protein 2 (PGLYRP2), mannose-associated serine protease 1 (MASP1), and ficolin-3 (FCN3), and immunoglobulin Kappa Variable 2D-30 (KVD30) Kappa Variable 2-40 (KV240), and Lambda Variable 4-03 (LV403) were assessed using selected reaction monitoring mass spectrometry.

Additionally, infants were subjected to the lactulose-mannitol test at nine months of age to determine intestinal permeability.

Stool samples collected from the infants were also used to analyze the levels of human beta-defensin-2 (HBD-2) and fecal calprotectin.

Major findings

The study found that while the hydrolyzed casein-based formula did not have any impact on β-cell autoimmunity or lower the risk of type 1 diabetes, it was effective in decreasing the permeability of the intestine and improving the intestinal epithelium integrity.

Proteomic analyses of serum samples from the mothers indicated significant proteomic changes associated with the pregnancy, with discernible differences between the serum proteome obtained during the third trimester, pregnancy, and three months postpartum.

These differences were observed largely in pregnancy-associated proteins such as oxytocinase, chorionic somatomammotropin hormones 1 and 2, and pregnancy-specific glycoproteins.

Similar differences were observed between the maternal serum proteome and the cord blood samples. The pregnancy-specific glycoproteins were not found in the cord blood proteome, neither were acute phase proteins such as C-reactive protein and serum amyloid A2.

In contrast, multiple inositol polyphosphate phosphatase, prolactin, and hemoglobin subunit zeta were only found in the cord blood proteome. However, all the serum samples found the immunoglobulin kappa chain variable proteins.

Clear differences associated with age were also observed in the serum samples obtained from the infants during the first year of development, especially in the immunoglobulin proteins.

The researchers believe these trends could result from a developing immune system and dietary antigen exposure. Additionally, fibroblast-derived protein PI16 and apolipoprotein A4 expression in the infant’s serum proteome decreased with age.

Conclusions

The study revealed discernible differences in maternal serum proteomes across various pregnancy and postpartum stages, between maternal and cord blood proteomes, and in the serum proteomes of the infants at various developmental stages during the first year.

Furthermore, the dietary intervention consisting of extensively hydrolyzed casein-based formula was not found to lower the risk of type 1 diabetes or impact β-cell autoimmunity.

However, it did decrease intestinal permeability, which was believed to be a result of lower dietary antigen exposure.