The first central precocious puberty proteomic profiles revealed multiple metabolic networks and novel key disease-associated proteins

The Role of Genetics in Central Precocious Puberty: Confirmed and Potential Neuroendocrine Genetic and Epigenetic Contributors and Their Interactions with Endocrine Disrupting Chemicals (EDCs)

Despite the growing prevalence of central precocious puberty (CPP), most cases are still diagnosed as “idiopathic” due to the lack of identifiable findings of other diagnostic etiology. We are gaining greater insight into some key genes affecting neurotransmitters and receptors and how they stimulate or inhibit gonadotropin-releasing hormone (GnRH) secretion, as well as transcriptional and epigenetic influences. Although the genetic contributions to pubertal regulation are more established in the hypogonadotropic hypogonadism (HH) literature, cases of CPP have provided the opportunity to learn more about its own genetic influences. There have been clinically confirmed cases of CPP associated with gene mutations in kisspeptin and its receptor (KISS1, KISS1R), Delta-like noncanonical Notch ligand 1 (DLK1), and the now most commonly identified genetic cause of CPP, makorin ring finger protein (MKRN3). In addition to these proven genetic causes, a number of other candidates continue to be evaluated. After reviewing the basic clinical aspects of puberty, we summarize what is known about the various genetic and epigenetic causes of CPP as well as discuss some of the potential effects of endocrine disrupting chemicals (EDCs) on some of these processes.

Integrated analysis of proteomics and metabolomics in girls with central precocious puberty

BACKGROUND

Central precocious puberty (CPP) is a multifactorial and complex condition. Traditional studies focusing on a single indicator cannot always elucidate this panoramic condition but these may be revealed by using omics techniques.

OBJECTIVE

Proteomics and metabolomics analysis of girls with CPP were compared to normal controls and the potential biomarkers and pathways involved were explored.

METHODS

Serum proteins and metabolites from normal girls and those with CPP were compared by LC-MS/MS. Multivariate and univariate statistical analysis were used to identify the differentially expressed proteins (DEPs) and differentially expressed metabolites (DEMs). Functional annotation and pathway enrichment analysis were performed by using GO and KEGG databases, and candidate markers were screened. Finally, bioinformatic analysis was used to integrate the results of proteomics and metabolomics to find the key differential proteins, metabolites and potential biomarkers of CPP.

RESULTS

134 DEPs were identified in girls with CPP with 71 up- and 63 down-regulated, respectively. Up-regulated proteins were enriched mainly in the extracellular matrix, cell adhesion and cellular protein metabolic processes, platelet degranulation and skeletal system development. The down-regulated proteins were mainly enriched in the immune response. Candidate proteins including MMP9, TIMP1, SPP1, CDC42, POSTN, COL1A1, COL6A1, COL2A1 and BMP1, were found that may be related to pubertal development. 103 DEMs were identified, including 42 up-regulated and 61 down-regulated metabolites which were mainly enriched in lipid and taurine metabolic pathways. KGML network analysis showed that phosphocholine (16:1(9Z)/16:1(9Z)) was involved in arachidonic acid, glycerophospholipid, linoleic acid and α-linolenic acid metabolism and it may be used as a biomarker of CPP.

CONCLUSIONS

Our study is the first to integrate proteomics and metabolomics to analyze the serum of girls with CPP and we found some key differential proteins and metabolites as well as a potential biomarker for this condition. Lipid metabolism pathways are involved and these may provide a key direction to further explore the molecular mechanisms and pathogenesis of CPP.