dentistry journal Review Human Gingival Crevicular Fluids (GCF) Proteomics: An Overview Zohaib Khurshid 1,*, Maria Mali 2, Mustafa Naseem 3, Shariq Najeeb 4 and Muhammad Sohail Zafar 5,6 1 Prosthodontics and Implantology, College of Dentistry, King Faisal University, Al-Ahsa 31982, Saudi Arabia 2 Department of Orthodontics, Fatima Jinnah Dental College, Karachi 78650, Pakistan; [email protected] 3 Preventive Dental Sciences, College of Dentistry, Dar-Al-Uloom University, Riyadh 13314, Saudi Arabia; [email protected] 4 Department of Dentistry, Riyadh Consultative Clinics, Riyadh 11313, Saudi Arabia; [email protected] 5 Department of Restorative Dentistry, College of Dentistry, Al-Taibah University, Medina Munawwarah 41311, Saudi Arabia; [email protected] 6 Department of Dental Materials, Islamic International Dental College, Riphah International University, Islamabad 44000, Pakistan * Correspondence: [email protected]; Tel.: +966-550-293-747 Academic Editor: Jukka Meurman Received: 21 January 2017; Accepted: 18 February 2017; Published: 22 February 2017 Abstract: Like other fluids of the human body, a gingival crevicular fluid (GCF) contains proteins, a diverse population of cells, desquamated epithelial cells, and bacteria from adjacent plaque. Proteomic tools have revolutionized the characterization of proteins and peptides and the detection of early disease changes in the human body. Gingival crevicular fluids (GCFs) are a very specific oral cavity fluid that represents periodontal health. Due to their non-invasive sampling, they have attracted proteome research and are used as diagnostic fluids for periodontal diseases and drug analysis. The aim of this review is to explore the proteomic science of gingival crevicular fluids (GCFs), their physiology, and their role in disease detection. Keywords: proteomics; proteins; biomarkers; gingival crevicular fluids (GCFs); dentistry 1. Introduction Proteomic science aids in different areas of biomedical and clinical sciences with tools such as polyacrylamide gel electrophoresis (PAGE), high-pressure liquid chromatography (HPLC), mass spectrometry (MS), matrix-assisted laser desorption ionization (MALDI), and surface-enhanced laser desorption/ionization mass spectrometry (SELDI-MS) [1]. This science provides an understanding of healthy and diseased states of the human body through protein nature. Protein builds the human body and is known as the “working horses” of a cell. The ‘proteome’ is the cell’s proteins content. In short, proteomics is the discovery technology that rescues the understanding of the molecular behaviour of protein activity and how they respond to the process of a disease. Human body fluids such as blood, cerebrospinal fluid (CSF), saliva, gingival crevicular fluid (GCF), sera, urine, vaginal secretion, breast milk, sputum, peritoneal fluid, pleural fluid, and pericardial fluids are approved clinical samples for the diagnosis and maintenance of a disease state [2]. Human gingival crevicular fluid (GCF) was discovered in the nineteenth century, and its composition and oral defense mechanism were demonstrated by Brill and Björn in 1959 [3]. GCF is a physiological fluid that is classified as inflammatory exudate by many investigators, and some suggest it is an altered tissue transudate in a normal healthy state (see Figure1). Originally, they originate Dent. J. 2017, 5, 12; doi:10.3390/dj5010012 www.mdpi.com/journal/dentistry Dent. J. 2017, 5, 12 2 of 9 Dent. J. 2017, 5, 12 2 of 8 Dent. J. 2017, 5, 12 2 of 9 originate from the gingival plexus of blood vessels in the gingival corium and are subjacent to the originatefromepithelium the gingivalfrom lining the plexus ofgingival the ofdental–gingival bloodplexus vessels of blood inspace. thevessels gingival Its incomposition the corium gingival and and corium are flow subjacent and were are demonstrated to subjacent the epithelium to theby epitheliumliningWaerhaug of the inlining dental–gingival1952 of[4,5]. the Later, dental–gingival space.in 1974, Its Alfano composition space. presented Its composition and two flow mechanisms were and demonstrated flow based were on demonstrated byGCF Waerhaug origination by in 1952Waerhaugthat [include4,5]. 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Figure 1. The anatomical location of gingival crevicular fluid (GCF) in a healthy subject. Figure 1. TheThe anatomical anatomical location location of gingival crev crevicularicular fluid fluid (GCF) in a healthy subject. 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The amount ThisThis of compositionGCF production variesvaries is between betweenquite small periodontium periodontium and varies in in healthy accordinghealthy and and diseasedto diseasedthe size conditions conditionsof the [9gingival]. The[9]. The amount sulcus. amount of GCFFew of GCFproductioninvestigators production is quitehave ismeasured small quite and small variesGCF, and and according allvaries observations toaccording the size have of to the differedthe gingival size due sulcus.of tothe the Fewgingival variation investigators sulcus. in the haveGCFFew investigatorsmeasuredsamples collected. GCF, have and measured all observations GCF, and have all differedobservations due tohave the differed variation due in theto the GCF variation samples in collected. the GCF samples collected. Figure 2. IllustrationIllustration describing describing the composition of gingival crevicular fluidsfluids (GCFs). Figure 2. Illustration describing the composition of gingival crevicular fluids (GCFs). One group reported that the mean GCF volume ranged from 0.43 to 1.56 μµL in the proximal spacesOne from group the reported molar teeth that [[10].10the]. mean Another GCF group volume collected ranged GCF from from 0.43 sulcusto 1.56 ofμ L slightly in the proximal inflamedinflamed spacesgingiva from and reported the molar approximately teeth [10]. Another 0.1 mg group in 3 min collected [11], [11], which GCF is from the amount sulcus of of slightly GCF affected inflamed by gingivamechanical and factors,reported habitats approximately (tobacco, 0.1 smoke, mg in and 3 min shisha), [11], circadian which is theperiodicity, amount of sex GCF hormones, affected and by mechanicalperiodontal factors, surgeries habitats (see Table (tobacco,1 1).). Engelberg Engelberg smoke, and et et al. shisha),al. experimentedexperimented circadian onperiodicity,on dogsdogs byby inducingsexinducing hormones, aa carboncarbon and periodontalgelatine mixture surgeries into the (see blood Table stream 1). 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