Therapeutic Potential of Local and Systemic Adipose-Derived Mesenchymal Stem Cell Injections in a Rat Model of Experimental Periodontitis: Implications for Cardiac Function

Abstract

Periodontitis is a common inflammatory disease that not only damages periodontal tissues but also induces systemic effects, including cardiac dysfunction. Mesenchymal stem cells (MSCs) offer regenerative potential due to their ability to differentiate, modulate immune responses, and secrete anti-inflammatory factors. However, the relative efficacy of local versus systemic MSC administration remains unclear. This study evaluated the therapeutic effects of adipose-derived MSCs (AD-MSCs) in a rat model of experimental periodontitis, comparing local and systemic administration. AD-MSCs were characterized based on morphology, surface marker expression, and differentiation potential. Ligature-induced periodontitis was established over 60 days, after which AD-MSCs (1 × 10⁶ cells) were administered either supraperiosteally (local group) or intravenously (systemic group). Periodontal regeneration was assessed through clinical, radiographic, and histopathological analyses, while cardiac function was evaluated using echocardiography and histopathological examinations. Results demonstrated that local AD-MSC administration provided superior therapeutic benefits compared to systemic delivery. Locally administered cells significantly enhanced bone regeneration, reduced inflammation, and improved periodontal tissue architecture. In contrast, systemic administration offered moderate benefits but was less effective in restoring periodontal integrity. Similarly, in the heart, local treatment resulted in greater improvements in systolic function, as indicated by enhanced ejection fraction and fractional shortening, along with reduced myocardial fibrosis. Although systemic administration also provided cardioprotective effects, diastolic dysfunction persisted in both treatment groups. In conclusion, local AD-MSC administration proved more effective in regenerating periodontal tissues and mitigating cardiac dysfunction, highlighting its potential as an optimized therapeutic strategy for periodontitis and its systemic complications.

Keywords: H&E staining; Masson’s trichrome staining; adipose-derived mesenchymal stem cells; cardiac dysfunction; echocardiography; myocardial fibrosis; periodontitis; radiography.

Figure 1

Representative image illustrating the morphology of rat AD-MSCs. At passage 4, the AD-MSCs displayed a spindle-shaped, fibroblast-like structure. Scale bar: 100 μm.

Figure 2

Phenotypic characterization of AD-MSCs. Flow cytometric analysis shows that the cultured AD-MSCs express CD29 and CD90, while lacking CD45 expression.

Figure 3

Multilineage differentiation of rat AD-MSCs. Adipogenesis was confirmed by Oil Red O staining, chondrogenesis by Alcian Blue staining, and osteogenesis by Alizarin Red staining. Scale bar: 100 μm.

Figure 4

Clinical assessment of alveolar bone loss in experimental groups. (A–D) Gross images of molar regions: (A) control group, (B) model group, (C) local AD-MSC-treated group, and (D) systemic AD-MSC-treated group. Red and yellow dashed lines indicate the cemento-enamel junction (CEJ) and alveolar bone crest (ABC), respectively. (E) Quantitative measurement of bone loss (mm) across groups. **** p < 0.0001, ** p < 0.01, ns = not significant.

Figure 5

Radiographic analysis of alveolar bone levels. (A–D) Representative radiographs of mandibular regions: (A) control group, (B) model group, (C) local AD-MSC-treated group, and (D) systemic AD-MSC-treated group. Brackets indicate bone loss measured as the distance from the cemento-enamel junction (CEJ) to the alveolar bone crest. Arrows highlight bone loss in the interproximal and interradicular regions.

Figure 6

Histopathological analysis of mandibular first molar tissues using H&E staining. (A) Control group showing intact tissue architecture with no inflammation or bone loss. (B) Model group displaying severe apical migration of the junctional epithelium and disorganized periodontal ligament (PDL). (C) Local treatment group showing partial restoration of tissue structure and reduced inflammation. (D) Systemic treatment group showing moderate recovery with less inflammation and structural improvement compared to the local group. Arrowheads indicate the position of the junctional epithelium in all panels. Scale bar: 100 μm. Abbreviations: C: cementum, R: tooth root, AB: alveolar bone, PDL: periodontal ligament.

Figure 7

Histopathological analysis of mandibular tissues (periodontal ligament) using Masson’s trichrome staining. (A) Control group showing dense, well-organized collagen fibers. (B) Model group displaying sparse and disorganized collagen fibers. (C) Local treatment group demonstrating improved collagen density and organization. (D) Systemic treatment group exhibiting increased collagen deposition but less organization compared to the local group. Scale bar: 100 μm. Abbreviations: R: tooth root, PDL: periodontal ligament.

Figure 8

Histopathological analysis of cardiac tissues using Hematoxylin and Eosin (H&E) staining. (A) Control group showing normal cardiac morphology with well-organized cardiomyocytes. (B) Model group exhibiting inflammatory cell infiltration and cell degeneration. (C) Local AD-MSC injection group demonstrating improved cardiac morphology with reduced inflammation and partial restoration of tissue organization. (D) Systemic AD-MSC injection group showing reduced inflammation and partial recovery of myocardial architecture (Green arrow: inflammatory cell infiltration; black arrow: degenerated cells). Scale bar: 100 μm.

Figure 9

Histopathological analysis of cardiac tissues using Masson’s trichrome staining. (A) Control group showing minimal collagen deposition, indicating the absence of fibrosis. (B) Model group displaying significant collagen deposition and fibrosis. (C) Local AD-MSC injection group exhibiting minimal fibrosis and improved structural integrity of cardiomyocytes. (D) Systemic AD-MSC injection group showing reduced fibrosis compared to the model group but with slightly higher collagen deposition than the local injection group. Scale bar: 100 μm.

Figure 10

Conventional echocardiographic analysis in the experimental groups. (A) Ejection fraction (EF%), (B) fractional shortening (FS%), (C) E/A ratio, (D) deceleration time (DecT), and (E) isovolumic relaxation time (IVRT). Data are presented as mean ± SD. Statistical significance is indicated as follows: * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001, ns = not significant. Comparisons are shown between the control, model, local AD-MSC-treated, and systemic AD-MSC-treated groups.

Figure 11

Overview of the experimental design.