Effect of Non-chirurgical Periodontal Treatment on the Innate and Adaptive Immunity From a Gender Perspective: Potential Therapeutic Implications of microRNAs

Blood, gingival crevicular fluid (GCF), and saliva samples will be collected from patients at baseline and 12 weeks after non-surgical periodontal treatment. From fasting blood samples (12h), peripheral blood mononuclear cells (PBMCs) and neutrophil fractions will be isolated using an immunomagnetic method, following the manufacturer's protocol, and plasma and serum will be stored at -80°C until analysis. LUNA-FL will be used to determine cell count and viability (acridine orange and propidium iodide double stain) in cell samples. GCF samples will be collected in duplicate by carefully inserting sterile paper points into the periodontal pocket 1 mm for 30 s. The volume will be determined using the Periotron 8000 and stored at -80°C for future determinations. Unstimulated saliva will be collected in RNase-free tubes by expectoration, and after centrifugation, the supernatant will be stored at -80°C for microRNA (miRNA) analysis.

Clinical periodontal parameters of probing pockets depth (PD), millimetres of clinical attachment level (CAL), bleeding on probing (BOP), simplified plaque index of Silness and Löe, and simplified calculus index of Greene and Vermillion will be determined using a conventional manual periodontal probe (UNC-15 PCP). A periodontal examination will be performed to measure PD, CAL, and BOP at six sites per tooth for all teeth, excluding third molars, as previously described. Patients will be interviewed about their medical history, lifestyle habits (smoking, frequency of tooth brushing, physical activity), and sociodemographic characteristics. Weight, height, and blood pressure will be measured using standardized methods. Biochemical parameters of carbohydrate metabolism - glucose, insulin, glycated hemoglobin (A1c) -, lipid profile - total cholesterol, LDL, HDL, triglycerides (TG), apolipoproteins AI and B -, emerging inflammatory and cardiovascular risk markers - C-Reactive Protein (CRP), C3c, and retinol-binding protein 4 (RBP4) -, and complete blood count will be determined at the hospital's Clinical Analysis Service.

For detection of differences in protein expression, cells will be incubated in lysis buffer with protease and phosphatase inhibitors (RIPA Buffer) for 15 minutes at 4 degrees celsius (°C). The supernatant will be collected after centrifugation for 15 minutes at 16,000g. The total protein concentration will be quantified using a bicinchoninic acid (BCA) protein assay. Aliquots of 25 µg of protein will be resolved on 8-16% gradient SDS-polyacrylamide gels and transferred to nitrocellulose membranes. Target proteins will be detected by incubating the membranes with anti-actin, JNK, NFkB, MCP1, GPX-1, NLRP3, ASC, procaspase 1, caspase 1, NADPH oxidase, catalase, GPX1, SOD1, Beclin, ATG5-ATG12, p62, LC3 I, LC3 II, Pink1, GRP78, eIF2alpha, IRE1 alpha, ATF6, CHOP, PGC1 alpha, mTFA, VDAC, Complex I, II, III, IV and V. The protein signal will be detected by chemiluminescence and analyzed by densitometry.

Inflammasome complex assembly (first stage of activation) through co-localization studies of NLRP3-ASC in PBMCs will be conducted using the confocal and/or fluorescence microscopy. Briefly, PBMCs will be seeded on coverslips coated with Poly-D-Lysine, fixed with paraformaldehyde (PFA) 4% for 20 minutes, permeabilized with Triton X-100 for 20 minutes and blocking with Phosphate-buffered saline buffer-Bovine serum albumn (PBS-BSA) 3% for 1 hour at room temperature. Hybridization with specific primary antibodies (diluted in PBS-BSA 1%) will be carry out overnight at 4 ºC and then, secondary antibodies conjugated with AlexaFluor fluorophores will be incubated for 1 hour in the dark at room temperature. Stained samples will be transferred the coverslip onto microscope slide and conserved in anti-fade fluorescence mounting medium.

Circulating levels of cytokines, adhesion molecules and serum oxidative stress markers will be measured in serum samples, but for secretome studies 1x10^6 PBMCs will be previously incubated in 1 mL RPMI with 10% fetal bovine serum (FBS) for 4 hours (37°C, 5% CO2) to obtain the supernatant. Both serums and supernatants will be analyzed with a Luminex® 200 analyzer system following the Milliplex® MAP Kit manufacturer's procedure. These same determinations will be carried out on GCF and serum/plasma samples from patients.