Salivary proteome signatures in the early and middle stages of human pregnancy with term birth outcome
Amit Dey, Bhoj Kumar, Abhishek Singh, Prakash Ranjan, Ramachandran Thiruvengadam, Bapu Koundinya Desiraju, Pallavi Kshetrapal, Nitya Wadhwa, Shinjini Bhatnagar, Faraz Rashid, Dipankar Malakar, Dinakar M. Salunke, Tushar Kanti Maiti, GARBH-Ini Study Group*, Bhabatosh Das, Sumit Misra, Balakrish G. Nair, Uma Chandra Mouli Natchu, Satyajit Rath, Kanika Sachdeva, Shailaja Sopory, Amanpreet Singh, Dharmendra Sharma, Vineeta Bal, Arindam Maitra, Partha P. Majumder, Monika Bahl, Sunita Sharma, Umesh Kumar Mehta, Brahmdeep Sindhu, Sugandha Arya, Rekha Bharti, Harish Chellani, Pratima Mittal, Siddarth Ramji, Reva Tripathi, Anju Garg, Ashok Khurana, Smriti Hari, Yashdeep Gupta, Nikhil Tandon, Rakesh Gupta
Abstract
The establishment and maintenance of pregnancy in humans proceed through a continuous change of biochemical and biophysical processes. It requires a constant interaction between the fetus and the maternal system. The present prospective study aims to elucidate changes in salivary proteome from the early to middle stages of term pregnancy, and establishing an expressional trajectory for modulated proteins. To date, a comprehensive characterization of the longitudinal salivary proteome in pregnancy has not been performed and it is our immediate interest. In the discovery phase, maternal saliva (N = 20) at 6-13, 18-21, and 26-29 weeks of gestation was analyzed using level-free proteomics (SWATH-MS) approach. The expression levels of 65 proteins were found to change significantly with gestational age and distributed into two distinct clusters with a unique expression trajectory. The results revealed that altered proteins are involved in maternal immune modulation, metabolism, and host defense mechanism. Further, verification of 12 proteins was employed using targeted mass spectrometry (MRM-MS) in a separate subset of saliva (N = 14). The MRM results of 12 selected proteins confirmed a similar expression pattern as in SWATH-MS analysis. Overall, the results not only demonstrate the longitudinal maternal saliva proteome for the first time but also set the groundwork for comparative analysis between term birth and adverse pregnancy outcomes.