Systematic comparison of the human saliva and plasma proteomes

Department of Biological Chemistry, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA, USA
PROTEOMICS - CLINICAL APPLICATIONS (Impact Factor: 2.96). 12/2008; 3(1):116 - 134. DOI: 10.1002/prca.200800140


The proteome of human salivary fluid has the potential to open new doors for disease biomarker discovery. A recent study to comprehensively identify and catalog the human ductal salivary proteome led to the compilation of 1166 proteins. The protein complexity of both saliva and plasma is large, suggesting that a comparison of these two proteomes will provide valuable insight into their physiological significance and an understanding of the unique and overlapping disease diagnostic potential that each fluid provides. To create a more comprehensive catalog of human salivary proteins, we have first compiled an extensive list of proteins from whole saliva (WS) identified through MS experiments. The WS list is thereafter combined with the proteins identified from the ductal parotid, and submandibular and sublingual (parotid/SMSL) salivas. In parallel, a core dataset of the human plasma proteome with 3020 protein identifications was recently released. A total of 1939 nonredundant salivary proteins were compiled from a total of 19 474 unique peptide sequences identified from whole and ductal salivas; 740 out of the total 1939 salivary proteins were identified in both whole and ductal saliva. A total of 597 of the salivary proteins have been observed in plasma. Gene ontology (GO) analysis showed similarities in the distributions of the saliva and plasma proteomes with regard to cellular localization, biological processes, and molecular function, but revealed differences which may be related to the different physiological functions of saliva and plasma. The comprehensive catalog of the salivary proteome and its comparison to the plasma proteome provides insights useful for future study, such as exploration of potential biomarkers for disease diagnostics.

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Available from: Mireya Gonzalez, Sep 29, 2015
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    • "Thus, high throughput proteomics holds promise for disease-associated biomarker identification [157] and substantial progress has been made in the proteomic analysis of saliva through a combination of sophisticated approaches to protein separation and advances in mass spectrometry technology [157, 158]. The salivary proteome has now been identified; it contains some 1166 proteins [159] and proteomic studies confirm the commonality of the salivary proteome and plasma proteins [159, 160]. Proteomic approaches have already identified salivary biomarkers of both Sjogren's syndrome and oral cancer [19, 161, 162]. "
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    ABSTRACT: Periodontitis is a chronic inflammatory condition of the tissues that surround and support the teeth and is initiated by inappropriate and excessive immune responses to bacteria in subgingival dental plaque leading to loss of the integrity of the periodontium, compromised tooth function, and eventually tooth loss. Periodontitis is an economically important disease as it is time-consuming and expensive to treat. Periodontitis has a worldwide prevalence of 5-15% and the prevalence of severe disease in western populations has increased in recent decades. Furthermore, periodontitis is more common in smokers, in obesity, in people with diabetes, and in heart disease patients although the pathogenic processes underpinning these links are, as yet, poorly understood. Diagnosis and monitoring of periodontitis rely on traditional clinical examinations which are inadequate to predict patient susceptibility, disease activity, and response to treatment. Studies of the immunopathogenesis of periodontitis and analysis of mediators in saliva have allowed the identification of many potentially useful biomarkers. Convenient measurement of these biomarkers using chairside analytical devices could form the basis for diagnostic tests which will aid the clinician and the patient in periodontitis management; this review will summarise this field and will identify the experimental, technical, and clinical issues that remain to be addressed before such tests can be implemented.
    04/2014; 2014:593151. DOI:10.1155/2014/593151
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    • "With the salivary proteome including thousands of non-redundant proteins identified (Loo et al, 2010), it is clear that their functions are diverse and many, as is reflected in the significant body of original work, as well as that summarized in several recent outstanding review articles. Some of these resources are listed below, and the reader is encouraged to refer to them especially on the subjects of the functions of saliva (Aps and Martens, 2005; Groschl, 2009; Salles et al, 2011); the composition of the salivary proteome (Groschl, 2008; Yan et al, 2009; Loo et al, 2010); and diagnostics values of saliva (Malamud, 2011; Pfaffe et al, 2011; Spielmann and Wong, 2011; Schapher et al, 2011). The subject of the current review, on the other hand, is less explored and it is related to a small but prominent category of salivary peptides – hormonal modulators of energy intake and output , hereafter referred to as metabolic hormones. "
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    ABSTRACT: The salivary proteome consists of thousands of proteins, which include, among others, hormonal modulators of energy intake and output. Although the functions of this prominent category of hormones in whole body energy metabolism are well characterized, their functions in the oral cavity, whether as a salivary component, or when expressed in taste cells, are less studied and poorly understood. The respective receptors for the majority of salivary metabolic hormones have been also shown to be expressed in salivary glands (SGs), taste cells, or other cells in the oral mucosa. This review provides a comprehensive account of the gastrointestinal hormones, adipokines, and neuropeptides identified in saliva, SGs, or lingual epithelium, as well as their respective cognate receptors expressed in the oral cavity. Surprisingly, few functions are assigned to salivary metabolic hormones, and these functions are mostly associated with the modulation of taste perception. Because of the well-characterized correlation between impaired oral nutrient sensing and increased energy intake and body mass index, a conceptually provocative point of view is introduced, whereupon it is argued that targeted changes in the composition of saliva could affect whole body metabolism in response to the activation of cognate receptors expressed locally in the oral mucosa.
    Oral Diseases 08/2012; 19(3). DOI:10.1111/odi.12015 · 2.43 Impact Factor
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    • "To tentatively reduce sample complexity and to remove bacteria and cellular debris, a centrifugation step is generally introduced in saliva treatment for proteomic analysis (reviewed in [7]). Nonetheless, no standardized procedure for saliva handling has yet been established albeit the technological improvements achieved in proteomics applied to the characterization of saliva composition, which allowed the identification of more than 3000 different species in this biological fluid [8] [9] [10] [11]. "
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    ABSTRACT: The present study aimed the evaluation of saliva sample pre-treatment, in particular the sample clearance usually performed by centrifugation, to the contribution of salivary proteome and peptidome. Using in-gel and off-gel approaches, a large content of salivary proteins was detected in the pellet fraction that is usually discarded. In addition, chaotropic/detergent treatment in combination with sonication, before the centrifugation step, resulted in salivary complex disruption and consequently in the extraction of high amounts of proteins. Based on this data, we suggest the use of urea/detergent with sonication as a standard saliva sample pre-treatment procedure. We also described a procedure to extract salivary peptides which can be performed even after saliva sample treatment with chaotropic/detergents. In overall, we reported for the first time the contribution of the pellet fraction to the whole saliva proteome. iTRAQ analysis highlighted a higher number of different peptides as well as distinct quantities of each protein class when after sample treatment with urea and sonication, acetone precipitation followed by solubilization with acetonitrile/HCl was performed.
    Journal of proteomics 07/2012; 75(17):5140-65. DOI:10.1016/j.jprot.2012.05.045 · 3.89 Impact Factor
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