Proteomics and Nucleotide Profiling as Tools for Biomarker and Drug Target Discovery.

Proteomics has gone through tremendous development during recent decades [...].

Early pregnancy levels of gingival crevicular fluid matrix metalloproteinases-8 and -9 are associated with the severity of periodontitis and the development of gestational diabetes mellitus.

BACKGROUND: Gestational diabetes mellitus (GDM) is increasing worldwide and women with a history of GDM are at risk of developing type 2 diabetes which is a risk factor for periodontitis. The aim of this study was to explore the association between the concentrations of matrix metalloproteinase (MMP)-8 and -9 in gingival crevicular fluid (GCF) during early pregnancy with the periodontal diagnosis and the risk of GDM development. METHODS: A prospective cohort study, including 314 women, enrolled at 11 to 14 weeks of pregnancy was conducted. A complete maternal/obstetric and periodontal exam was performed, and GCF samples were obtained for the MMP-8 and -9 determination by Multiplex Elisa Assays. Mann-Whitney test; Spearman's correlation and log-binomial regression model estimated the association between MMPs concentration in GCF and GDM. RESULTS: Fourteen percent of the pregnancies were diagnosed with GDM. An increase in the concentration of MMP-8 and -9 in women with periodontitis stage III and IV compared to periodontitis stage I was observed (99.31 ng/mL [IQR: 85.32] versus 71.95 ng/mL [IQR: 54.04], and 262.4 ng/mL [IQR: 312.55] versus 114.1 ng/mL [IQR: 184.94], respectively). Women who developed GDM showed increased concentrations of MMP-8 and -9 in GCF since the beginning of pregnancy (P = 0.0381; P = 0.0302, respectively). MMP-8 concentration in GCF was associated with GDM (RR: 1.19; P = 0.045; CI 95% 1.00 to 1.40; and RR: 1.20; P = 0.063; CI 95% 0.99 to 1.45 in the adjusted model). CONCLUSION(S): GCF concentrations of MMP-8 and -9 at early of pregnancy are increased in women with severe periodontitis and associated with the GDM development.

Compartmentalized profiling of amniotic fluid cytokines in women with preterm labor.

OBJECTIVE: Amniotic fluid cytokines have been implicated in the mechanisms of preterm labor and birth. Cytokines can be packaged within or on the surface of extracellular vesicles. The main aim of this study was to test whether the protein abundance internal to and on the surface of extracellular vesicles changes in the presence of sterile intra-amniotic inflammation and proven intra-amniotic infection in women with preterm labor as compared to the women with preterm labor without either intra-amniotic inflammation or proven intra-amniotic infection. STUDY DESIGN: Women who had an episode of preterm labor and underwent an amniocentesis for the diagnosis of intra-amniotic infection or intra-amniotic inflammation were classified into three groups: 1) preterm labor without either intra-amniotic inflammation or proven intra-amniotic infection, 2) preterm labor with sterile intra-amniotic inflammation, and 3) preterm labor with intra-amniotic infection. The concentrations of 38 proteins were determined on the extracellular vesicle surface, within the vesicles, and in the soluble fraction of amniotic fluid. RESULTS: 1) Intra-amniotic inflammation, regardless of detected microbes, was associated with an increased abundance of amniotic fluid cytokines on the extracellular vesicle surface, within vesicles, and in the soluble fraction. These changes were most prominent in women with proven intra-amniotic infection. 2) Cytokine changes on the surface of extracellular vesicles were correlated with those determined in the soluble fraction; yet the magnitude of the increase was significantly different between these compartments. 3) The performance of prediction models of early preterm delivery based on measurements on the extracellular vesicle surface was equivalent to those based on the soluble fraction. CONCLUSIONS: Differential packaging of amniotic fluid cytokines in extracellular vesicles during preterm labor with sterile intra-amniotic inflammation or proven intra-amniotic infection is reported herein for the first time. The current study provides insights into the biology of the intra-amniotic fluid ad may aid in the development of biomarkers for obstetrical disease.

Method Development for the Detection of Human Myostatin by High-Resolution and Targeted Mass Spectrometry.

Myostatin, a highly conserved secretory protein, negatively regulates muscle development, affecting both the proliferation and differentiation of muscle cells. Proteolytic processing of the myostatin precursor protein generates a myostatin pro-peptide and mature protein. Dimerization of the mature myostatin protein creates the active form of myostatin. Myostatin dimer activity can be inhibited by noncovalent binding of two monomeric myostatin pro-peptides. This ability for myostatin to self-regulate as well as the altered expression of myostatin in states of abnormal health (e.g., muscle wasting) support the need for specific detection of myostatin forms. Current protein detection methods (e.g., Western blot) rely greatly on antibodies and are semiquantitative at best. Tandem mass spectometry (as in this study) provides a highly specific method of detection, enabling the characterization of myostatin protein forms through the analysis of discrete peptides fragments. Utilizing the scheduled high-resolution multiple reaction monitoring paradigm (sMRMHR; AB SCIEX 5600 TripleTOF) we identified the lower limit of quantitation (LLOQ) of both mature (DFGLDCDEHSTESR) and pro-peptide regions (ELIDQYDVQR) as 0.19 nmol/L. Furthermore, scheduled multiple reaction monitoring (sMRM; AB SCIEX QTRAP 5500) identified a LLOQ for a peptide of the pro-peptide region (LETAPNISK) as 0.16 nmol/L and a peptide of the mature region (EQIIYGK) as 0.25 nmol/L.

Temporal expression of antioxidants in human cervicovaginal fluid associated with spontaneous labor.

Proteomic analysis of human cervicovaginal fluid (CVF) by 2D electrophoresis revealed significant differential expression of several major antioxidant enzymes during late pregnancy and term labor. Temporal quantitative changes of total antioxidant capacity (TAC), Cu,Zn superoxide dismutase (Cu,Zn SOD) and thioredoxin-1 (Trx-1) with impending term labor were investigated, and the potential of these biomarkers as individual and multiple predictors of labor was determined. The TAC of CVF (n = 193) was 8-fold significantly lower in labor, and approximately 2-fold significantly lower at 0-7, 8-14, 15-21, and 22-28 days, compared with >or=29 days prior to labor onset (p < 0.001). The expression of Cu,Zn SOD (n = 170) was 1.5- to 1.9-fold significantly decreased in labor (p < 0.001). Trx-1 (n = 163) was 2.8- to 5.1-fold significantly lower in labor (p = 0.002). The combination of TAC and Cu,Zn SOD produced the best predictive efficacy with 74% sensitivity and 95% specificity to predict term labor within 3 days of onset. These findings suggest that labor is associated with increased oxidative stress well before its onset and is reflected in the human CVF. The biomarkers identified in this study could serve as predictors of labor and offer potential strategies for novel therapeutics.

Protein profiling the effects of in vitro hyperoxic exposure on fetal rabbit lung.

The aim of this study was to test the hypothesis that acute in vitro exposure of prematurely delivered fetal rabbit lungs to hyperoxic conditions will induce the expression of an adaptive cassette of proteins that mediates antioxidant and inflammatory processes. To test this hypothesis, ex situ fetal rabbit lung explants were prepared from New Zealand white rabbits delivered by cesarean section on day 29 of gestation and incubated under air (21% O2; 5% CO2) or hyperoxic (95% O2; 5% CO2) atmospheres. Total tissue protein was extracted following incubation and subjected to 2-DE. Using this technique, 1500-2000 protein spots were resolved per gel. Treatment-dependent, differentially expressed proteins were identified by image analysis (Melanie II) and MALDI-TOF MS and MALDI-MS/MS. The analysis identified 12 protein spots that were differentially expressed by 1.5-fold or more (p<0.05) by exposure to hyperoxic conditions. Six of these differentially expressed proteins were identified as vimentin, annexin I, inorganic pyrophosphatase, prohibitin, an N-terminal fragment of ATP synthase and heat shock protein 27. The data obtained are consistent with the roles of these proteins in mediating cellular response to oxidative stress and in regulating cell proliferation.