Characterization of macrophage polarization in periodontal disease

Abstract

Aim To explore the M1/M2 status of macrophage polarization from healthy, gingivitis, and periodontitis patient samples. Materials and methods Gingival biopsies were collected from 42 individuals (14 gingivitis, 18 periodontitis, and 10 healthy samples) receiving periodontal therapy. Histomorphology analysis was performed with haematoxylin and eosin staining. Immunofluorescence was performed using a combination of CD68 (macrophages), iNOS (M1), and CD206 (M2) in order to acquire changes in macrophage polarization at a single‐cell resolution. Macrophages were quantified under microscopy using narrow wavelength filters to detect Alexa 488, Alexa 568, Alexa 633 fluorophores, and Hoechst 33342 to identify cellular DNA content. Results Gingivitis and periodontitis samples showed higher levels of macrophages compared with healthy samples. Unexpectedly, periodontitis samples displayed lower levels of macrophages dispersed in the stromal tissues compared with gingivitis samples; however, it remained higher than healthy tissues. The polarization of macrophages appears to be reduced in periodontitis and showed similar levels to those observed in healthy tissues. Conclusions Our study found that gingivitis and periodontitis differ from each other by the levels of macrophage infiltrate, but not by changes in macrophage polarization.

Characterization of macrophages infiltrating peri‐implantitis lesions

“…Here, we investigated the macrophages content within peri‐implantitis lesions and compared it with our previously reported cohort of periodontitis patients (Garaicoa‐Pazmino et al, ). Our results showed that soft tissues from periodontitis have an inflammatory infiltrate containing significant levels of CD68 + macrophages.…”

“…Xue and colleagues used the transcriptional activation states of macrophage in M1 vs. M2 to identify nine distinct macrophage activation programs (Xue et al, ). Such findings could explain the double‐positive staining of macrophages with iNOS and CD206, which were noted in the present and previous study by our group (Garaicoa‐Pazmino et al, ).…”

“…After evaluation and clinical indication for implant removal, patients were informed about the study conditions and signed written consent for the surgical procedure. Biopsy from periodontitis patients was previously reported (Garaicoa‐Pazmino et al, ).…”

“…Patients with periodontitis were also excluded if presenting with uncontrolled systemic disease or conditions known to alter bone metabolism (i.e., osteoporosis, osteopenia, hyperparathyroidism, or Paget's disease), pregnancy, history of oral cancer, sepsis or adverse outcomes to oral procedures, long‐term use of antibiotics over 2 weeks in the past two months, smokers, former smokers, and patients taking medications known to modify bone metabolism. Inclusion criteria for periodontitis patients were previously reported (Garaicoa‐Pazmino et al, ).…”

“…Tissue sections of 5 µm were prepared for histological examination. Periodontitis tissue samples were obtained at the University of Michigan School of Dentistry between September 2015 and March 2018 (Garaicoa‐Pazmino et al, ). The periodontitis samples were obtained from the most accessible target lesions associated with traditional periodontal flap procedures.…”