Comparative serum proteome analysis reveals potential early pregnancy-specific protein biomarkers in pigs

Abstract

In this study, the comparative serum proteome profile of Day 5, 12 and 16 of gestation, representing three early embryonic events, namely formation, elongation and implantation of blastocysts, and non-pregnant control were explored by a label-free quantitation-based mass spectrometric approach to identify early pregnancy biomarkers in pigs. A total of 131 proteins were identified with respect to different groups, out of which 105 were found to be differentially expressed proteins (DEPs). Among the DEPs, 54 and 66 proteins were found to be up and downregulated respectively in early pregnancy groups (fold change >2) and the maximum number of upregulated proteins was observed in the Day 12 pregnancy stage. Functional classification and pathway analysis of the DEPs revealed involvement of most of the proteins in complement and coagulation cascades, metabolic processes and immune and inflammatory responses. Proteins such as glutathione peroxidise (GPX), pregnancy zone protein (PZP), thrombospondin-1 (THBS1), α-1-antitrypsin (AAT) and mannose-binding lectin C (MBLC) were differentially expressed during early pregnancy and actively involved in different pregnancy-related activities. To the best of our knowledge, this is the first report on comparative serum protein profiling of different early pregnancy stages in pigs and our results provide a set of proteins that can be used as potential biomarkers for early pregnancy diagnosis in pigs.

Quantitative analysis of the serum proteome during early pregnancy in mares

“…This protein plays a key role in inflammation, permeability, angiogenesis, tumor metastasis, and cell proliferation (Rauch et al, 2013). Previous studies also hypothesized that VWF could be important in maternal recognition and embryogenesis of pregnancy in cattle (Beindorff et al, 2010), buffaloes (Balhara et al, 2014), and pigs (De et al, 2019). Furthermore, the expression of CALD1 and FBLN-5 was unique in the serum of early pregnant mares.…”

“…The functional classification of DEPs shows the similar BPs of metabolic process as previous reports of uterine proteome on horses (Smits et al, 2018), and serum proteome on donkeys (Deng et al, 2020) and pigs (De et al, 2019). Meanwhile, binding and extracellular region was the most represented MF and CC terms, respectively.…”

Reactive oxygen and nitrogen species regulate porcine embryo development during pre-implantation period: A mini-review

“…A previous study of pigs indicated that gene expression of glutathione peroxidase 1 ( GPX1 ), microsomal glutathione S-transferase 1 ( MGST1 ) and cytoplasmic copper-zinc superoxide dismutase ( SOD1 ) increased during conceptus elongation ( Blomberg et al., 2005 ). Similarly, a serum proteome-based study of pigs also demonstrated that GPX3 and copper-containing acute-phase protein increased during this period ( De et al., 2019 ). Mun et al.…”

Generation of reference serum proteome map for monitoring swine health

“…To enrich LAPs, ProteoMiner TM kit (Bio-Rad, Hercules, CA, USA) with hexapeptide ligand library was employed according to the manufacturer's instruction. Protein sample was subjected to nano ESI-LC MS/MS analysis thrice (technical replicates) for their identification at Valerian Chem Private Limited, New Delhi, India, following the procedure mentioned in our previous study (De et al 2019).…”

“…Proteins including glutathione peroxidase, pregnancy zone protein, thrombospondin-1, serpins, mannose-binding lectin-C etc. have been reported to be potential biomarkers for physiological processes like pregnancy (Jalali et al 2016, Kolakowska et al 2017, De et al 2019. Whereas, vitronectin was proposed as potential biomarker to predict feed efficiency in young pigs (Grubbs et al 2016).…”