Total glucosides of paeony improves the immunomodulatory capacity of MSCs partially via the miR-124/STAT3 pathway in oral lichen planus
Introduction
Mesenchymal stem cells (MSCs) are adult stem cells, which were first isolated and identified in the bone marrow (BM). MSCs have now been found in many other tissues, such as adipose, umbilical cord blood, dental pulp and oral mucosa [[1], [2], [3], [4]].
MSCs have been reported to be fibroblast-like cells that positively express CD105, CD73 and CD90, while negatively expressing CD45, CD34, CD14 or CD11b, CD79a or CD19 and HLA-DR [5]. For their self-renewal, multipotency and immunomodulatory properties, MSCs are an attractive tool for regenerative medicine and immune-related diseases. To date, MSCs have been used to treat several immune-related diseases in clinical and experimental trials, such as graft-versus-host disease (GVHD), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and inflammatory bowel disease (IBD) [[6], [7], [8], [9]]. Most cases have obtained favourable outcomes. However, some studies have shown that the inflammatory microenvironment affects the immunomodulatory function of MSCs [[10], [11], [12], [13]]. This might be due to a poor survival rate of MSCs, leading to the weakened immunoregulatory properties and treatment efficacy.
Oral lichen planus (OLP) is recognised as a chronic inflammatory disease that involves oral mucosa and may be accompanied by skin lesions, which has no obvious cause [14]. The prevalence of OLP in the general adult population is 0.5–3% and often found in middle-aged female patients [15]. Moreover, it has a frequency of malignant transformation between 0.4% and 5% [[16], [17], [18]]. In terms of the pathogenesis of OLP, some studies have shown that uncertain stimulations can activate dendritic cells. They produced interleukin IL-12, IL-18 and tumour necrosis factor alpha (TNF-α) to home T cells to lesions and activate T cell differentiation into Th1 and Th17 cells. These cells secrete many inflammatory mediators, including IL-6, IL-8 and TNF-α, finally leading to OLP lesions [14]. MSCs in OLP tissues were first isolated in our previous study [1]. However, whether the functions of OLP-derived MSCs (OLP-MSCs) are impaired and the relationship between the function of OLP-MSCs and the progression of OLP remain largely unknown.
Total glucosides of paeony (TGP) is an effective constituent purified and extracted from the dried root of Paeonia. Paeonia lactiflora, which is called “Shao Yao” in Chinese, has been widely used in China as a therapeutic drug for pain, congestion and inflammation [19]. Studies show that TGP dramatically impacts immune-related diseases, such as RA, psoriasis and SLE [[20], [21], [22]]. TGP can increase synoviocyte proliferation and reduce IL-1β, TNF-α, IL-2 and IL-6 expression and increase IL-4, IL-10 and TGF-β expression through the cAMP [23,24] and NF-κB pathways [25]. In clinical therapy, TGP has been proven as a safe and effective drug for OLP with rare side effects [26]. However, the effect of TGP on OLP-MSCs has not yet been investigated.
Several studies have shown that microRNAs (miRs) play a very important role in regulating inflammation-related diseases [[27], [28], [29]]. miRs are non-coding transcripts of 18–25 nucleotides. miR-124 is a member of miRNAs. In traumatic brain injury (TBI), miR-124-3p in microglial exosomes after TBI can inhibit neuronal inflammation and contribute to neurite outgrowth via inhibiting mTOR signalling [28]. In addition, phosphorylated signal transducer and activator of transcription 3 (p-STAT3) would be decreased if increased miR-124-3p expression in IBD [30]. Similar reports show that overexpression of miR-124-3p downregulates inflammatory cytokine by blocking nuclear factor (NF)-κB signalling [31]. Moreover, miR124-3p expression the affects the self-renewal of mouse embryonic stem cells by inhibiting the MEK/ERK pathway [32].However, the effect of miR-124-3p on the immunomodulatory function of MSCs has not been reported so far.
In this study, the effect of TGP on OLP-MSCs will be investigated to further explore its possible mechanisms. We also investigated whether function of MSCs primed with TGP is enhanced via the miR-124-3p/STAT3 pathway and whether TGP may recover the damaged immunomodulatory function of OLP-MSCs.
Section snippets
OLP clinical specimen collection
OLP tissues biopsied from the buccal mucosa of OLP patients. OLP diagnoses agreed with the modified World Health Organisation diagnostic criteria for OLP [31]. Normal oral mucosal tissues were obtained from patients who underwent the crown lengthening surgery or mucous retention cyst resection. Samples were obtained between September 2016 and March 2017 and stored at a biobank at the Peking University School of Stomatology. The following inclusion criteria were used: OLP patients confirmed by
Expression of IL-6, TNF-α, TGF-β and IL-10 in OLP and normal sub-epithelial lamina tissues
To verify the expression of IL-6, TNF-α, TGF-β and IL-10 in OLP and normal sub-epithelial lamina tissues, immunohistochemical staining was performed. As shown in Fig. 1, compared with normal sub-epithelial lamina, four cytokines all expressed significantly higher in OLP tissues, which confirmed that the OLP microenvironment co-exists between pro-inflammatory and anti-inflammatory cytokines.
Production of IL-6, TNF-α, TGF-β and IL-10 in N-MSCs and OLP-MSCs
To explore the effect of the OLP microenvironment on MSCs, we performed reverse transcription (RT)-PCR and
Discussion
OLP is a chronic inflammatory disease characterised by dense sub-epithelial lymphocytic infiltration, increased number of intra-epithelial lymphocytes and degeneration of basal keratinocytes. Additionally, it prevails among 40-60-year-old female patients [16,33]. In this study, OLP tissues expressed more IL-6, TNF-α, and IL-10 than control. Given that OLP has a high morbidity in people more than 40 years old and has complex inflammation conditions. It is unknown whether anything of OLP-MSCs has
Conflict of interest
All authors have read the journal’s policy on the disclosure of potential conflicts of interest and have none to declare.
Acknowledgments
This study was supported by the National Natural Science Foundation of China (nos. 81441034 and 81772873), Foundation of Capital Health Development (2014-2-4102 and 2011-4025-02), and Beijing Natural Science Foundation (nos. 7172240 and 7182181).
References (46)
- et al.
External factors influencing mesenchymal stem cell fate in vitro
Eur. J. Cell Biol.
(2017) - et al.
Minimal criteria for defining multipotent mesenchymal stromal cells. The International Society for cellular therapy position statement
Cytotherapy
(2006) - et al.
TNF-alpha inhibitor reverse the effects of human umbilical cord-derived stem cells on experimental arthritis by increasing immunosuppression
Cell. Immunol.
(2012) Etiology and pathogenesis of oral lichen planus: an overview
Oral Surg. Oral Med. Oral Pathol. Oral Radiol.
(2016)Oral lichen planus
Otolaryngol. Clin. North Am.
(2011)- et al.
Total glucosides of paeony for rheumatoid arthritis: a systematic review of randomized controlled trials
Complement. Ther. Med.
(2017) - et al.
Paeoniflorin suppressed IL-22 via p38 MAPK pathway and exerts anti-psoriatic effect
Life Sci.
(2017) - et al.
Total glucosides of paeony induces regulatory CD4(+)CD25(+) T cells by increasing Foxp3 demethylation in lupus CD4(+) T cells
Clin. Immunol.
(2012) - et al.
Effects and mechanisms of total glucosides of paeony on synoviocytes activities in rat collagen-induced arthritis
J. Ethnopharmacol.
(2009) - et al.
Paeoniflorin induced immune tolerance of mesenteric lymph node lymphocytes via enhancing beta 2-adrenergic receptor desensitization in rats with adjuvant arthritis
Int. Immunopharmacol.
(2007)