Altered Differentiation of Tendon-Derived Stem Cells in Diabetic Conditions Mediated by Macrophage Migration Inhibitory Factor.

The purpose of our study was to evaluate the role of macrophage migration inhibitory factor (MIF) in the differentiation of tendon-derived stem cells (TdSCs) under hyperglycemic conditions. In the in vivo experiment, rats were classified into diabetic (DM) and non-DM groups depending on the intraperitoneal streptozotocin (STZ) or saline injection. Twelve-week after STZ injection, the supraspinatus tendon was harvested and prepared for histological evaluation and real-time reverse transcription polymerase chain reaction for osteochondrogenic (aggrecan, BMP-2, and Sox9) and tenogenic (Egr1, Mkx, scleraxis, type 1 collagen, and Tnmd) markers. For the in vitro experiment, TdSCs were isolated from healthy rat Achilles tendons. Cultured TdSCs were treated with methylglyoxal and recombinant MIF or MIF gene knockdown to determine the effect of hyperglycemic conditions and MIF on the differentiation function of TdSCs. These conditions were classified into four groups: hyperglycemic-control group, hyperglycemic-recombinant-MIF group, hyperglycemic-knockdown-MIF group, and normal-control group. The mRNA expression of osteochondrogenic and tenogenic markers was compared among the groups. In the in vivo experiment, the mRNA expression of all osteochondrogenic and tenogenic differentiation markers in the DM group was significantly higher and lower than that in the non-DM group, respectively. Similarly, in the in vitro experiments, the expression of all osteochondrogenic and tenogenic differentiation markers was significantly upregulated and downregulated, respectively, in the hyperglycemic-control group compared to that in the normal-control group. The hyperglycemic-knockdown-MIF group demonstrated significantly decreased expression of all osteochondrogenic differentiation markers and increased expression of only some tenogenic differentiation markers compared with the hyperglycemic-control group. In contrast, the hyperglycemic-recombinant-MIF group showed significantly increased expression of all osteochondrogenic differentiation markers, but no significant difference in any tenogenic marker level, compared to the hyperglycemic-control group. These results suggest that tendon homeostasis could be affected by hyperglycemic conditions, and MIF appears to alter the differentiation of TdSCs via enhancement of the osteochondrogenic differentiation in hyperglycemic conditions. These are preliminary findings, and must be confirmed in a further study.

Expression of macrophage migration inhibitory factor in footpad skin lesions with diabetic neuropathy.

Background Diabetic neuropathy originating in distal lower extremities is associated with pain early in the disease course, overwhelming in the feet. However, the pathogenesis of diabetic neuropathy remains unclear. Macrophage migration inhibitory factor has been implicated in the onset of neuropathic pain and the development of diabetes. Objective of this study was to observe pain syndromes elicited in the footpad of diabetic neuropathy rat model and to assess the contributory role of migration inhibitory factor in the pathogenesis of diabetic neuropathy. Methods Diabetic neuropathy was made in Sprague Dawley rats by streptozotocin. Pain threshold was evaluated using von Frey monofilaments for 24 weeks. On comparable experiment time after streptozotocin injection, all footpads were prepared for following procedures; glutathione assay, terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling staining, immunohistochemistry staining, real-time reverse transcription polymerase chain reaction, and Western blot. Additionally, human HaCaT skin keratinocytes were treated with methylglyoxal, transfected with migration inhibitory factor/control small interfering RNA, and prepared for real-time reverse transcription polymerase chain reaction and Western blot. Results As compared to sham group, pain threshold was significantly reduced in diabetic neuropathy group, and glutathione was decreased in footpad skin, simultaneously, cell death was increased. Over-expression of migration inhibitory factor, accompanied by low expression of glyoxalase-I and intraepidermal nerve fibers, was shown on the footpad skin lesions of diabetic neuropathy. But, there was no significance in expression of neurotransmitters and inflammatory mediators such as transient receptor potential vanilloid 1, mas-related G protein coupled receptor D, nuclear factor kappa B, tumor necrosis factor-alpha, and interleukin-6 between diabetic neuropathy group and sham group. Intriguingly, small interfering RNA-transfected knockdown of the migration inhibitory factor gene in methylglyoxal-treated skin keratinocytes increased expression of glyoxalase-I and intraepidermal nerve fibers in comparison with control small interfering RNA-transfected cells, which was decreased by induction of methylglyoxal. Conclusions Our findings suggest that migration inhibitory factor can aggravate diabetic neuropathy by suppressing glyoxalase-I and intraepidermal nerve fibers on the footpad skin lesions and provoke pain. Taken together, migration inhibitory factor might offer a pharmacological approach to alleviate pain syndromes in diabetic neuropathy.

Single-Cell Profiling Reveals Immune-Based Mechanisms Underlying Tumor Radiosensitization by a Novel Mn Porphyrin Clinical Candidate, MnTnBuOE-2-PyP5+ (BMX-001).

Manganese porphyrins reportedly exhibit synergic effects when combined with irradiation. However, an in-depth understanding of intratumoral heterogeneity and immune pathways, as affected by Mn porphyrins, remains limited. Here, we explored the mechanisms underlying immunomodulation of a clinical candidate, MnTnBuOE-2-PyP5+ (BMX-001, MnBuOE), using single-cell analysis in a murine carcinoma model. Mice bearing 4T1 tumors were divided into four groups: control, MnBuOE, radiotherapy (RT), and combined MnBuOE and radiotherapy (MnBuOE/RT). In epithelial cells, the epithelial-mesenchymal transition, TNF-α signaling via NF-кB, angiogenesis, and hypoxia-related genes were significantly downregulated in the MnBuOE/RT group compared with the RT group. All subtypes of cancer-associated fibroblasts (CAFs) were clearly reduced in MnBuOE and MnBuOE/RT. Inhibitory receptor-ligand interactions, in which epithelial cells and CAFs interacted with CD8+ T cells, were significantly lower in the MnBuOE/RT group than in the RT group. Trajectory analysis showed that dendritic cells maturation-associated markers were increased in MnBuOE/RT. M1 macrophages were significantly increased in the MnBuOE/RT group compared with the RT group, whereas myeloid-derived suppressor cells were decreased. CellChat analysis showed that the number of cell-cell communications was the lowest in the MnBuOE/RT group. Our study is the first to provide evidence for the combined radiotherapy with a novel Mn porphyrin clinical candidate, BMX-001, from the perspective of each cell type within the tumor microenvironment.

Excessive walking exercise precipitates diabetic neuropathic foot pain: hind paw suspension treadmill exercise experiment in a rat model.

The harmful effects of excessive mechanical loading on diabetic neuropathy and the reason diabetic neuropathic symptoms are common in feet are unclear. In this study, the hind paw suspension treadmill exercise model was used in rats to investigate whether mechanical loading applied to the front paws precipitates neuropathic pain, especially in diabetic conditions. Thirty-two rats were divided into six groups according to the presence of diabetes (DM) and the intensity of mechanical loading applied to the front paws: DM-Hi (high-intensity); DM-Lo (low-intensity); DM-No (non-mechanical loading); Sham-Hi; Sham-Lo; and Sham-No. DM was induced by streptozotocin injection. For high-intensity or low-intensity mechanical loading, treadmill walking exercise was conducted with or without hind paw suspension, respectively. The mechanical withdrawal threshold of the front paw decreased significantly after 8 weeks only in the DM mechanical loading groups (DM-Hi and DM-Lo), and high-intensity loading more significantly decreased the front-paw withdrawal threshold than low-intensity loading. In the DM-Hi group only, macrophage migration inhibitory factor (MIF) increased significantly, and intra-epidermal nerve fibers (IENF) in the front paws decreased significantly. In diabetic conditions, mechanical overloading such as excessive walking is likely to precipitate mechanical allodynia and damage IENF¸ which could explain why diabetic neuropathic symptoms are common in feet. This finding might be related to up-regulation of intracellular signaling cascades such as MIF, rather than inflammatory processes.

Therapeutic effects of topical application of ozone on acute cutaneous wound healing.

This study was undertaken to evaluate the therapeutic effects of topical ozonated olive oil on acute cutaneous wound healing in a guinea pig model and also to elucidate its therapeutic mechanism. After creating full-thickness skin wounds on the backs of guinea pigs by using a 6 mm punch biopsy, we examined the wound healing effect of topically applied ozonated olive oil (ozone group), as compared to the pure olive oil (oil group) and non-treatment (control group). The ozone group of guinea pig had a significantly smaller wound size and a residual wound area than the oil group, on days 5 (P<0.05) and 7 (P<0.01 and P<0.05) after wound surgery, respectively. Both hematoxylin-eosin staining and Masson-trichrome staining revealed an increased intensity of collagen fibers and a greater number of fibroblasts in the ozone group than that in the oil group on day 7. Immunohistochemical staining demonstrated upregulation of platelet derived growth factor (PDGF), transforming growth factor-beta (TGF-beta) and vascular endothelial growth factor (VEGF) expressions, but not fibroblast growth factor expression in the ozone group on day 7, as compared with the oil group. In conclusion, these results demonstrate that topical application of ozonated olive oil can accelerate acute cutaneous wound repair in a guinea pig in association with the increased expression of PDGF, TGF-beta, and VEGF.

Epigallocatechin-3-gallate improves Dermatophagoides pteronissinus extract-induced atopic dermatitis-like skin lesions in NC/Nga mice by suppressing macrophage migration inhibitory factor.

Epigallocatechin-3-gallate (EGCG) has been shown to exert anti-inflammatory effects on the inflammatory skin conditions. However, little is known about its effect on atopic dermatitis (AD). We first attempted to assess the anti-inflammatory effect of topical application of EGCG in vivo AD model using NC/Nga mice and to determine whether EGCG exerts the anti-inflammatory effect by inhibiting macrophage migration inhibitory factor (MIF) and other cytokines that are related to immune dysregulation in the pathogenesis of AD. Murine AD-like skin lesions were made by painting Dermatophagoides pteronissinus extract (DPE). The effects of EGCG treatment were assessed by total clinical severity score and ear thickness, and by histological grading. In addition, the mRNA and protein expression of the cytokines including MIF were measured by real-time RT-PCR and immunohistochemistry. The serum levels of MIF and IgE were measured by ELISA. In the AD mouse model, EGCG significantly reduced the total clinical severity score and ear thickness (p<0.05). The histological grading was also markedly improved. The mRNA expression of MIF, TNF-alpha, IFN-gamma, IL-2 and IL-12 p40, but not of IL-4, IL-5 and IL-13 in the lesions was significantly reduced by EGCG (p<0.05). On the immunohistochemistry, EGCG also markedly diminished the expression of MIF, TNF-alpha and IFN-gamma. The serum MIF and IgE production was significantly reduced by EGCG (p<0.05). These results demonstrate that topical application of EGCG may improve the AD-like skin lesions by suppressing MIF and T helper 1 cytokines. Taken together, it is suggested that EGCG may be a potential therapeutic modality for AD.

The Expression of NMDA Receptor 1 Correlates with Clinicopathological Parameters in Cutaneous Squamous Cell Carcinoma.

BACKGROUND: Ionotropic glutamate receptors of the N-methyl-D-aspartate receptor (NMDAR) type are expressed on keratinocytes and play a role in the proliferation, differentiation, and cornification of keratinocytes. However, the expression profile of NMDAR and its role in cutaneous malignancy is unclear. OBJECTIVE: We analyzed the expression of NMDAR-1 in cutaneous squamous cell carcinoma (SCC) and investigated the relationship between NMDAR-1 expression and clinicopathological parameters. METHODS: Thirty-two patients with biopsy-proven cutaneous SCC were enrolled in this study. Each patient was analyzed for tumor diameter, location, local recurrence, and metastasis by conducting a chart review. The SCC specimens were histologically divided into differentiated and undifferentiated groups based on Broders' system. NMDAR-1 expression was examined by performing immunohistochemistry, and the relative staining intensity in the SCCs was graded into 5 levels. According to the staining intensity of NMDAR-1, the specimens were categorized into two groups: the higher group and the lower group. RESULTS: Fifteen (88%) of 17 tumors in the higher group were differentiated SCC, whereas 14 (93%) of 15 tumors in the lower group were undifferentiated SCC. In addition, NMDAR-1 expression was inversely correlated with metastasis (p=0.049). Local recurrence was associated with a lower staining intensity, but the results were not statistically significant. CONCLUSION: Our results demonstrate that NMDAR-1 expression in cutaneous SCC is significantly correlated with its differentiation and metastasis. Therefore, it may be a prognostic indicator for cutaneous SCC.