Affiliations: Department of Surgical, Oncological and
Gastroenterological Sciences, 2nd Surgical Clinic, University of Padova,
Padova, Italy | Department of Nanomedicine, The Methodist Hospital
Research Institute, Houston, TX, USA | Istituto di Ricerca Pediatrica-Cittá della
Speranza, Padova, Italy | CNR-ISTM, C.so Stati Uniti 4, Padova, Italy | Department of Pharmaceutical Sciences, Largo
Meneghetti 2, Padova, Italy
Note: [] Corresponding author: Mirto Foletto, MD, Department of Surgical,
Oncological and Gastroenterological Sciences, 2nd Surgical Clinic, University
of Padova, Via Giustiniani 2, Padova 35128, Italy. Tel.: +39 049-8212075; Fax:
+39 049-651891; E-mail: mirto.foletto@unipd.it
Abstract: BACKGROUND: Obesity is currently epidemic in many countries
worldwide and is strongly related to diabetes and cardiovascular disease. Mass
spectrometry, in particular matrix-assisted laser desorption/ionization time of
flight (MALDI-TOF) is currently used for detecting different pattern of
expressed protein. This study investigated the differences in low molecular
weight (LMW) peptide profiles between obese and normal-weight subjects in
combination with multivariate statistical analysis. MATERIALS: Serum samples of 60 obese patients and 10 healthy
subjects were treated by cut-off membrane (30000 Da) to remove the most
abundant proteins. The filtrates containing the LMW protein/peptides were
analyzed by MALDI-TOF mass spectrometry. Dataset was elaborated to align and
normalize the spectra. We performed cluster analysis and principal component
analysis to detect some ionic species that could characterize and classify the
subject groups. RESULTS: We observed a down-expression of ionic species at m/z
655.94 and an over-expression of species at m/z 1518.78, 1536.77, 1537.78 and
1537.81 in obese patients. Furthermore we found some ionic species that can
distinguish obese patients with diabetes from those with normal glucose level.
CONCLUSION: Serum peptide profile of LMW associate with multivariate
statistical approach was revealed as a promising tool to discriminate and
characterize obese patients and it was able to stratify them in relation to
comorbidity that usually are associated with this disease. Further research
involving a larger sample will be required to validate these findings.
Keywords: Obesity, MALDI-TOF, serum profile, principal component analysis, cluster analysis
