MERC Proteins in Saliva and GCF in Periodontal Disease (ELISA Study)

NCT07601685 | Completed

• 2 other identifiers: IUCTEC.2024/06TDH-2024-3464
• Study Type: observational
• Target: 48
• Locations: 1 country
• Sites: 1

Brief Summary

This observational cross-sectional study investigates the levels of mitochondria-endoplasmic reticulum contact site (MERC) proteins in saliva and gingival crevicular fluid (GCF) of individuals with different periodontal conditions. MERCs are specialized regions where mitochondria and the endoplasmic reticulum physically connect, and they play important roles in calcium signaling, oxidative stress regulation, and cell death (apoptosis). Disruption of these contact sites has been linked to inflammatory diseases, including periodontal disease. The study includes 48 systemically healthy, non-smoking adults divided into three groups: periodontally healthy (n=16), gingivitis (n=16), and Stage III Grade B periodontitis (n=16). Five MERC-associated proteins (VAPB, PTPIP51, IP3R, GRP75, and VDAC) are measured in GCF and saliva samples using ELISA. Additionally, caspase-3 (a marker of apoptosis), reactive oxygen species (a marker of oxidative stress), and calcium levels are measured to explore relationships between MERC proteins and key cellular processes involved in periodontal tissue destruction. The purpose of this study is to determine whether MERC protein levels differ across periodontal conditions and to evaluate their associations with clinical periodontal parameters, oxidative stress, calcium metabolism, and apoptosis.

Conditions

Periodontitis; Biomarker Discovery and Validation; Pathways; Gingivitis and Periodontal Diseases

Keywords

MERC; Mitochondria-Endoplasmic Reticulum Contact; VAPB; PTPIP51; IP3R; GRP75; VDAC; Caspase-3; Reactive Oxygen Species; Calcium; Gingival Crevicular Fluid; Saliva; ELISA; Oxidative Stress; Apoptosis

Outcome Measures

Primary Outcomes (22)

• GCF VAPB Levels

  Concentrations and total amounts of VAPB in gingival crevicular fluid measured by ELISA.

  At baseline (single visit)

• Salivary VAPB Levels

  Concentrations of VAPB (pg/mL) in unstimulated whole saliva measured by ELISA.

  At baseline (single visit)

• GCF PTPIP51 Levels

  Concentrations and total amounts of PTPIP51 in gingival crevicular fluid measured by ELISA.

  At baseline (single visit)

• Salivary PTPIP51 Levels

  Concentrations of PTPIP51 (ng/L) in unstimulated whole saliva measured by ELISA.

  At baseline (single visit)

• GCF IP3R Levels

  Concentrations and total amounts of IP3R in gingival crevicular fluid measured by ELISA.

  At baseline (single visit)

• Salivary IP3R Levels

  Concentrations of IP3R (ng/mL) in unstimulated whole saliva measured by ELISA.

  At baseline (single visit)

• GCF GRP75 Levels

  Concentrations and total amounts of GRP75 in gingival crevicular fluid measured by ELISA.

  At baseline (single visit)

• Salivary GRP75 Levels

  Concentrations of GRP75 (ng/mL) in unstimulated whole saliva measured by ELISA.

  At baseline (single visit)

• GCF VDAC Levels

  Concentrations and total amounts of VDAC in gingival crevicular fluid measured by ELISA.

  At baseline (single visit)

• Salivary VDAC Levels

  Concentrations of VDAC (ng/mL) in unstimulated whole saliva measured by ELISA.

  At baseline (single visit)

• GCF Caspase-3 Levels

  Concentrations and total amounts of caspase-3 (ng/mL) in gingival crevicular fluid measured by ELISA.

  At baseline (single visit)

• Salivary Caspase-3 Levels

  Concentrations of caspase-3 (ng/mL) in unstimulated whole saliva measured by ELISA.

  At baseline (single visit)

• GCF Reactive Oxygen Species Levels

  Concentrations and total amounts of reactive oxygen species (ROS) in gingival crevicular fluid measured by ELISA.

  At baseline (single visit)

• Salivary Reactive Oxygen Species Levels

  Concentrations of reactive oxygen species (ROS) in unstimulated whole saliva measured by ELISA.

  At baseline (single visit)

• GCF Calcium Levels

  Concentrations and total amounts of calcium (µmol/mL) in gingival crevicular fluid measured by ELISA.

  At baseline (single visit)

• Salivary Calcium Levels

  Concentrations of calcium (µmol/mL) in unstimulated whole saliva measured by ELISA.

  At baseline (single visit)

• Plaque Index

  Plaque Index (PI) recorded at sampling sites.

  At baseline (single visit)

• Gingival Index

  Gingival Index (GI) recorded at sampling sites.

  At baseline (single visit)

• Probing Depth

  Probing Depth (PD) recorded at sampling sites.

  At baseline (single visit)

• Bleeding on Probing

  Bleeding on Probing (BOP%) recorded at sampling sites.

  At baseline (single visit)

• Clinical Attachment Level

  Clinical Attachment Level (CAL) recorded at sampling sites.

  At baseline (single visit)

• Gingival Crevicular Fluid Volume

  Gingival crevicular fluid (GCF) volume measured at sampling sites.

  At baseline (single visit)

Study Arms (3)

Periodontally Healthy

Systemically healthy, non-smoking individuals with no history of periodontal disease. Inclusion criteria: ≥20 teeth, probing depth (PD) ≤3 mm at all sites, bleeding on probing (BOP) \<10%, and radiographic CEJ-to-alveolar bone crest distance ≤3 mm in ≥95% of teeth. n=16 (8 females, 8 males).

Diagnostic Test: ELISA Biomarker Analysis; Diagnostic Test: Calcium Measurement

Gingivitis

Systemically healthy, non-smoking individuals with gingival inflammation but no attachment loss. Inclusion criteria: ≥20 teeth, PD ≤3 mm at all sites, BOP ≥30%, and radiographic CEJ-to-alveolar bone crest distance ≤3 mm in ≥95% of teeth. n=16 (8 females, 8 males).

Diagnostic Test: ELISA Biomarker Analysis; Diagnostic Test: Calcium Measurement

Stage III Grade B Periodontitis

Systemically healthy, non-smoking individuals with Stage III Grade B periodontitis. Inclusion criteria: ≥15 teeth, \>30% of teeth affected, PD ≥6 mm, CAL ≥5 mm, vertical bone loss ≥3 mm, Class II/III furcation involvement, radiographic bone loss extending to the middle third or beyond (≥33%), and bone loss-to-age ratio between 0.25 and 1.00. n=16 (8 females, 8 males).

Diagnostic Test: ELISA Biomarker Analysis; Diagnostic Test: Calcium Measurement

Interventions

ELISA Biomarker Analysis DIAGNOSTIC_TEST

Levels of MERC-associated proteins (VAPB, PTPIP51, IP3R, GRP75, VDAC), caspase-3, reactive oxygen species, and calcium were measured in gingival crevicular fluid and unstimulated whole saliva samples using commercially available ELISA kits. Absorbance was read at 450 nm. No therapeutic intervention was applied; this is an observational biomarker measurement study.

Gingivitis; Periodontally Healthy; Stage III Grade B Periodontitis

Calcium Measurement DIAGNOSTIC_TEST

Calcium levels were measured in gingival crevicular fluid and unstimulated whole saliva samples using a commercially available ELISA kit (ELK Biotechnology, China). Concentrations were expressed as μmol/mL and total amounts as μmol/30s. Analytical range: 0.15-40 μmol/mL. No therapeutic intervention was applied.

Gingivitis; Periodontally Healthy; Stage III Grade B Periodontitis

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Systemically healthy, non-smoking individuals aged 18-65 years who presented to the Department of Periodontology, Faculty of Dentistry, Inonu University, Malatya, Turkiye for examination and/or treatment between January 2024 and May 2024. Participants were classified into three groups based on the 2017 World Workshop criteria: periodontally healthy (n=16), gingivitis (n=16), and Stage III Grade B periodontitis (n=16), with equal sex distribution (8 males and 8 females per group).

You may qualify if:

• Systemically healthy individuals aged 18-65 years
• Non-smokers or smoking cessation more than 5 years ago
• Healthy group: No history of periodontal disease, ≥20 teeth, probing depth (PD) ≤3 mm at all sites, bleeding on probing (BOP) \<10%, radiographic CEJ-to-alveolar bone crest distance ≤3 mm in ≥95% of teeth
• Gingivitis group: No history of periodontal disease, ≥20 teeth, PD ≤3 mm at all sites, BOP ≥30%, radiographic CEJ-to-alveolar bone crest distance ≤3 mm in ≥95% of teeth
• Periodontitis group: ≥15 teeth, \>30% of teeth affected by periodontal disease, PD ≥6 mm, clinical attachment loss (CAL) ≥5 mm, vertical bone loss ≥3 mm, Class II or III furcation involvement, radiographic alveolar bone loss extending to the middle third or beyond (≥33%), bone loss-to-age ratio between 0.25 and 1.00

You may not qualify if:

• Periodontal treatment or antibiotic use within the past 6 months
• Fewer than 20 teeth (excluding third molars)
• Presence of any systemic disease
• Current smoking or cessation within the past 5 years
• Use of immunosuppressive medication
• Alcohol consumption
• Regular medication use
• Pregnancy or lactation
• Need for antibiotic prophylaxis prior to dental procedures
• Prosthetic restorations on the teeth selected for sampling

Sponsors & Collaborators

• Inonu University: lead
• Harvard University: collaborator
• University of Minnesota: collaborator

Study Sites (1)

Inönü University Faculty of Dentistry, Department of Periodontology

Malatya, Malatya, 44210, Turkey (Türkiye)

Location

Related Publications (6)

• Chapple ILC, Mealey BL, Van Dyke TE, Bartold PM, Dommisch H, Eickholz P, Geisinger ML, Genco RJ, Glogauer M, Goldstein M, Griffin TJ, Holmstrup P, Johnson GK, Kapila Y, Lang NP, Meyle J, Murakami S, Plemons J, Romito GA, Shapira L, Tatakis DN, Teughels W, Trombelli L, Walter C, Wimmer G, Xenoudi P, Yoshie H. Periodontal health and gingival diseases and conditions on an intact and a reduced periodontium: Consensus report of workgroup 1 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions. J Periodontol. 2018 Jun;89 Suppl 1:S74-S84. doi: 10.1002/JPER.17-0719.

  PMID: 29926944 BACKGROUND

• Papapanou PN, Sanz M, Buduneli N, Dietrich T, Feres M, Fine DH, Flemmig TF, Garcia R, Giannobile WV, Graziani F, Greenwell H, Herrera D, Kao RT, Kebschull M, Kinane DF, Kirkwood KL, Kocher T, Kornman KS, Kumar PS, Loos BG, Machtei E, Meng H, Mombelli A, Needleman I, Offenbacher S, Seymour GJ, Teles R, Tonetti MS. Periodontitis: Consensus report of workgroup 2 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions. J Clin Periodontol. 2018 Jun;45 Suppl 20:S162-S170. doi: 10.1111/jcpe.12946.

  PMID: 29926490 BACKGROUND

• Lim D, Dematteis G, Tapella L, Genazzani AA, Cali T, Brini M, Verkhratsky A. Ca2+ handling at the mitochondria-ER contact sites in neurodegeneration. Cell Calcium. 2021 Sep;98:102453. doi: 10.1016/j.ceca.2021.102453. Epub 2021 Aug 5.

  PMID: 34399235 BACKGROUND

• Lee S, Min KT. The Interface Between ER and Mitochondria: Molecular Compositions and Functions. Mol Cells. 2018 Dec 31;41(12):1000-1007. doi: 10.14348/molcells.2018.0438. Epub 2018 Dec 12.

  PMID: 30590907 BACKGROUND

• Kirmizigul OA, Sabanci A, Disli F, Yildiz S, Milward MR, Aral K. Evaluation of the role of mitofusin-1 and mitofusin-2 in periodontal disease. J Periodontol. 2024 Jan;95(1):64-73. doi: 10.1002/JPER.23-0072. Epub 2023 Jul 24.

  PMID: 37436713 BACKGROUND

• Aral K, Milward MR, Cooper PR. Gene expression profiles of mitochondria-endoplasmic reticulum tethering in human gingival fibroblasts in response to periodontal pathogens. Arch Oral Biol. 2021 Aug;128:105173. doi: 10.1016/j.archoralbio.2021.105173. Epub 2021 May 27.

  PMID: 34058723 BACKGROUND

Biospecimen

Retention: SAMPLES WITHOUT DNA

Gingival crevicular fluid (GCF) collected from the sulcus/pocket of three single-rooted teeth per participant using standardized paper strips (Periopaper, Oraflow Inc., USA) with absorbed volume measured by Periotron 8000. Unstimulated whole saliva collected using the passive drooling method for 5 minutes. All samples stored in phosphate-buffered saline at -80°C until ELISA analysis.

MeSH Terms

Conditions

Periodontitis; Gingivitis; Periodontal Diseases; Spinocerebellar Ataxias

Condition Hierarchy (Ancestors)

Mouth Diseases; Stomatognathic Diseases; Infections; Gingival Diseases; Cerebellar Ataxia; Cerebellar Diseases; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Spinocerebellar Degenerations; Spinal Cord Diseases; Heredodegenerative Disorders, Nervous System; Neurodegenerative Diseases; Ataxia; Dyskinesias; Neurologic Manifestations; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Study Officials

• Cüneyt A Aral, Professor, DDS, PhD

  Inonu University

  STUDY CHAIR

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Periodontology, Inonu University Faculty of Dentistry

Study Record Dates

• First Submitted: May 13, 2026
• First Posted: May 22, 2026
• Study Start: January 10, 2024
• Primary Completion: January 1, 2025
• Study Completion: April 1, 2025
• Last Updated: May 22, 2026

Record last verified: 2026-05

Locations

TU (1)