Anti-inflammatory effects of intranasal cyclosporine for allergic rhinitis in a mouse model

Mast cell-mediated mechanistic pathways in organ transplantation

Adaptive immunity has gained importance in transplant immunology for years, based on models in which T-cells orchestrate the immune responses during rejection. Most recently, researches revealed that innate immune cells, including mast cells (MCs) also play a pivotal role in allograft rejection. MC mediated immunoregulatory responses influence the innate and adaptive immune responses. Their capability to produce an array of both pro-inflammatory and anti-inflammatory mediators, expressing a wide range of costimulatory molecules in addition to acting as antigen-presenting cells (APCs), make them effective immune cells far beyond their classical role as primary orchestrator cells of allergy. Activated regulatory Tcells (Treg) cells contribute to MC recruitment into grafts by releasing interleukin (IL)-9. Tregs are capable of stabilizing MCs and suppressing IgE mediated degranulation through interaction of Treg expressing OX40 with MCs expressing OX40L. MCs in turn release transforming growth factor (TGF)-β and IL-10 which possess suppressive properties. Thus, these cells can suppress the proliferation of T-cells and support the generation of Tregs. MCs in addition to orchestrating immune responses in grafts by cell-to-cell interactions with variety of immune cells, cause histologic changes, mainly fibrosis by releasing mediators such as histamine, fibroblast growth factor-2 (FGF-2), TGF-β, chymase, and cathepsin G. The role of MCs in transplant rejection remains controversial. The accumulation of MCs in rejected grafts suggests that they play a role in preventing graft tolerance, and contribute to the progression of chronic rejection of allografts. However, high expression of MC-related gene products in tolerant grafts and their known interaction with Tregs on the other hand, support the notion that they are an integral component in achieving peripheral tolerance.

Establishment and verification of a mouse model of nasal wound healing

OBJECTIVES

Poor wound healing as reflected by the development of synechia and osteitis after endoscopic sinus surgery may trigger disease recurrence. Animal models provide insights into the pathogenesis of poor wound healing and may aid in the development of new therapeutics. Here, we established a mouse model of nasal wound healing and confirmed its utility.

STUDY DESIGN

Animal study.

METHODS

Unilateral intranasal wounds were induced using a small interdental brush in 6-week-old C57BL/6 mice. Forty-five mice were divided into three groups (each n = 15): one control and two experimental groups (intranasal vs. intraperitoneal dexamethasone). Mice were sacrificed on days 2, 14, and 28 after injury (each n = 5). Serial changes in nasal wound histopathology were described, and intergroup differences were analyzed.

RESULTS

On day 2, mucosal detachment, hemorrhage, and exudate were observed. On day 14, synechiae featuring neo-osteogenesis (bone lacunae, osteoblasts, and multinucleated osteoclasts) between the septum and the maxilloturbinate were prominent, followed by wound maturation on day 28: fewer lacunae and smaller osteoblasts. Macrophages were evident only on day 2, and lymphocytes were predominant on day 28. The amount of exudate on day 2 and the synechial area on day 28 were significantly reduced in mice that received dexamethasone systemically compared with control mice, with similar trends in those treated intranasally.

CONCLUSION

Our mouse model of nasal wound healing was characterized by the development of bony synechia and neo-osteogenesis, not soft-tissue synechia. The model may be useful in the assessment of novel therapeutics to prevent those wounds.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:E266-E271, 2019.

Effect of cyclosporin A intervention on the immunological mechanisms of coronary heart disease and restenosis

The present study aimed to investigate the effect of cyclosporin A (CSA) intervention on the immunological mechanisms underlying coronary heart disease (CHD) and restenosis (RS) in rabbits. A total of 48 rabbits were randomly divided into normal control (N), N + CSA, CHD model, CHD + CSA, RS model and RS + CSA groups. Rabbits in the respective groups received different treatments prior to sacrifice at the end of week 12. Iliac arteries were harvested from the rabbits for morphological analysis and to determine the mRNA and protein expression levels of cluster of differentiation (CD) 40/CD40 ligand (CD40L), CD134/CD134 ligand (CD134L) and inflammatory factors, including matrix metalloproteinase (MMP)-1, MMP-9, vascular cell adhesion protein (VCAM)-1, interleukin (IL)-6 and tumor necrosis factor (TNF)-α, by reverse transcription-quantitative polymerase chain reaction and immunohistochemical staining. As compared with the N group, the mRNA expression levels of MMP-9, VCAM-1 and TNF-α were significantly increased in the CHD and RS groups (P<0.05), but were significantly decreased in the groups with CSA intervention, as compared with those without CSA intervention (P<0.05). Conversely, there were no significant differences in the expression levels of MMP-1 and IL-6 among the six groups, although a decreasing trend of IL-6 expression was observed following intervention with CSA. Furthermore, there were significant differences in the mRNA and protein expression levels of CD40/CD40L and CD134/CD134L among the N, CHD and RS groups (P<0.05), and between the groups with and without CSA intervention. The present study demonstrated that CSA intervention exerted beneficial effects on CHD and RS, and further studies are required to investigate the mechanisms underlying the effects of CSA on CHD.