Tacrolimus abrogates TGF-β1-induced type I collagen production in normal human fibroblasts through suppressing p38MAPK signalling pathway: implications on treatment of chronic atopic dermatitis lesions

Immunolocalization of Matrix Metalloproteinases 2 and 9 and Their Inhibitors in the Hearts of Rats Treated with Immunosuppressive Drugs-An Artificial Intelligence-Based Digital Analysis

BACKGROUND

Immunosuppressive agents represent a broad group of drugs, such as calcineurin inhibitors, mTOR inhibitors, and glucocorticosteroids, among others. These drugs are widely used in a number of conditions, but lifelong therapy is crucial in the case of organ recipients to prevent rejection. To further increase the safety and efficacy of these agents, their off-target mechanisms of action, as well as processes underlying the pathogenesis of adverse effects, need to be thoroughly investigated. The aim of this study was to examine the impact of various combinations of cyclosporine/tacrolimus/mycophenolate with rapamycin and steroids (CRG, TRG, MRG), on the morphology and morphometry of rats' cardiomyocytes, together with the presence of cardiac collagen and the immunoexpression of MMPs and TIMPs.

METHODS

Twenty-four rats were divided into four groups receiving different immunosuppressive regiments. After six months of treatment, the hearts were collected and analyzed.

RESULTS

Cardiomyocytes from the CRG cohorts demonstrated the most pronounced morphological alterations. In addition, chronic immunosuppression reduced the width and length of cardiac cells. However, immunosuppressive therapy did not alter the presence of cardiac collagen fibers. Nevertheless, we observed significant alterations regarding MMP/TIMP homeostasis.

CONCLUSIONS

Chronic immunosuppression seems to disturb the MMP/TIMP balance in aspects of immunolocalization in the hearts of rats. Further studies are required to analyze other mechanisms and pathways affected by the use of immunosuppressants.

Tacrolimus ameliorates bleomycin-induced pulmonary fibrosis by inhibiting M2 macrophage polarization via JAK2/STAT3 signaling

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease of unknown cause and characterized by excessive proliferation of fibroblasts and the irregular remodeling of extracellular matrix (ECM), which ultimately cause the severe distortion of the alveolar architecture. The median survival of IPF patients is 2-5 years. IPF patients are predominantly infiltrated by M2 macrophages during the course of disease development and progression. Predominantly accumulation of M2 macrophages accelerates fibrosis progression by secreting multiple cytokines that promote fibroblast to myofibroblast transition. In the process of M2 macrophage polarization, JAK2/STAT3 signaling plays a key role, thus, targeting activated macrophages to inhibit the pro-fibrotic phenotype is considered as an approach to the potential treatment of IPF. Tacrolimus is a macrolide antibiotic that as a specific inhibitor of T-lymphocyte function and has been used widely as an immunosuppressant in human organ transplantation. In this study we explored the potential effect and mechanism of tacrolimus on pulmonary fibrosis in vivo and vitro. Here, we found that tacrolimus is capable of suppressing M2 macrophages polarization by inhibiting pro-fibrotic factors secreted by M2 macrophages. This effect further alleviates M2-induced myofibroblast activation, thus resulting in a decline of collagen deposition, pro-fibrotic cytokines secretion, recovering of lung function, ultimately relieving the progression of fibrosis in vivo. Mechanistically, we found that tacrolimus can inhibit the activation of JAK2/STAT3 signaling by targeting JAK2. Our findings indicate a potential anti-fibrotic effect of tacrolimus by regulating macrophage polarization and might be meaningful in clinical settings.

Homing of vertebral‐delivered mesenchymal stromal cells for degenerative intervertebral discs repair – an in vivo proof‐of‐concept study

Introduction

Cell transplantation shows promising results for intervertebral disc (IVD) repair, however, contemporary strategies present concerns regarding needle puncture damage, cell retention, and straining the limited nutrient availability. Mesenchymal stromal cell (MSC) homing is a natural mechanism of long-distance cellular migration to sites of damage and regeneration. Previous ex vivo studies have confirmed the potential of MSC to migrate over the endplate and enhance IVD-matrix production. In this study, we aimed to exploit this mechanism to engender IVD repair in a rat disc degeneration model.

Methods

Female Sprague Dawley rats were subjected to coccygeal disc degeneration through nucleus pulposus (NP) aspiration. In part 1; MSC or saline was transplanted into the vertebrae neighboring healthy or degenerative IVD subjected to irradiation or left untouched, and the ability to maintain the IVD integrity for 2 and 4 weeks was assessed by disc height index (DHI) and histology. For part 2, ubiquitously GFP expressing MSC were transplanted either intradiscally or vertebrally, and regenerative outcomes were compared at days 1, 5, and 14 post-transplantation. Moreover, the homing potential from vertebrae to IVD of the GFP⁺ MSC was assessed through cryosection mediated immunohistochemistry.

Results

Part 1 of the study revealed significantly improved maintenance of DHI for IVD vertebrally receiving MSC. Moreover, histological observations revealed a trend of IVD integrity maintenance. Part 2 of the study highlighted the enhanced DHI and matrix integrity for discs receiving MSC vertebrally compared with intradiscal injection. Moreover, GFP rates highlighted MSC migration and integration in the IVD at similar rates as the intradiscally treated cohort.

Conclusion

Vertebrally transplanted MSC had a beneficial effect on the degenerative cascade in their neighboring IVD, and thus potentially present an alternative administration strategy. Further investigation will be needed to determine the long-term effects, elucidate the role of cellular homing versus paracrine signaling, and validate our observations on a large animal model.

Assessment of serum concentrations of matrix metalloproteinase 1, matrix metalloproteinase 2 and tissue inhibitors of metalloproteinases 1 in atopic dermatitis in correlation with disease severity and epidermal barrier parameters

Introduction

Matrix metalloproteinases (MMPs) are a group of proteolytic enzymes, conditioning the integrity of skin cells, however, their role in the inflammatory process of atopic dermatitis (AD) and the direct effect on the epidermal barrier parameters remain unexplained.

Aim

To assess MMP-1, MMP-2, tissue inhibitors of metalloproteinases (TIMP)-1 concentrations in blood serum in the context of transepidermal water loss (TEWL) and stratum corneum hydration in AD. Moreover, serum levels of MMPs and TIMP-1 were analysed in relation to the Eczema Area and Severity Index (EASI).

Material and methods

Forty-three AD patients and 22 control group subjects have been investigated. Serum concentrations of MMP-1, MMP-2, and TIMP-1 have been evaluated with ELISA. TEWL and stratum corneum hydration have been assessed with a TM300 Tewameter and a CM825 Corneometer. Skin lesions in patients with AD have been evaluated with the Eczema Area and Severity Index.

Results

MMP-1 and MMP-2 serum concentrations were significantly higher in the AD group. The results of TIMP-1 serum concentration were similar for both groups. The correlation between the serum concentration and the EASI was demonstrated only for MMP-2 for patients with severe and moderate AD. Patients with AD and TIMP-1 serum concentration greater than MMP-1 presented lower TEWL and higher epidermal hydration.

Conclusions

The results of this study warrant further investigation. The predominance of TIMP-1 over MMP-1 in blood serum can potentially limit TEWL and maintain the proper water content of the epidermis. Future work is necessary to establish how reliable the role of MMP-2 concentration is as an indicator of the severity of AD.

Systemic Immunosuppression for Prevention of Recurrent Tendon Adhesions

Background:

The recovery for patients after tendon repair is frequently limited by development of tendon adhesions. This scar tissue formation is dependent on immune system activation. Tacrolimus has unique properties that may contribute to the prevention of overactive scarring by inhibition of inflammatory cytokines.

Methods:

Herein, we present a case using systemic immunosuppression to prevent recurrent adhesion accumulation in a patient with a prior spaghetti wrist injury. Tacrolimus began 1 week before repeat-secondary tenolysis surgery, and it continued for 3 months postoperative. Dosing was tapered to a serum level between 5 and 8 µg/L.

Results:

The 27-year-old male patient suffered a volar wrist laceration transecting all flexor tendons and volar wrist nerves. He underwent immediate repair but had a poor outcome despite early range of motion therapy. A primary tenolysis only improved his average arc of finger motion from 72 to 95 degrees. Secondary tenolysis augmented with systemic tacrolimus improved his arc of finger motion from 95 to 202 degrees. Mechanistically, tacrolimus prevents proper function of activated T and B cells. This results in decreased proliferation, angiogenesis, and cytoskeletal organization of fibroblasts on inflammation and integrin adhesions, and it potentially explains the reduced tendon molecule adhesions seen in this patient.

Conclusions:

Tacrolimus may be effective in reducing motion, limiting tendon adhesions. The novel use of this medication resulted in the return of near-normal hand function in a patient placed on low-dose tacrolimus after primary tenolysis had failed.

Plasticity of Treg and imbalance of Treg/Th17 cells in patients with systemic sclerosis modified by FK506

To determine the effects of Tacrolimus (FK506) on Treg cells and subpopulations in SSc patients and assess the ability of FK506 to modify the immune imbalance of Treg/Th17 cells. We analyzed PBMC from five SSc patients and six healthy control by flow cytometry after cultured with 0, 0.1, 1, or 10 ng/ml FK506 in vitro. The number of Treg cells decreased in SSc patients treated with FK506. The number of FrI cells were decreased in SSc following FK506 treatment. The drug did increase the frequency of FrII/Treg cells, but not FrII cells. However, FK506 significantly decreased FrIII in both SSc patients and controls. FK506 clearly decreased the numbers of Th17 cells and FoxP3⁺IL-17⁺ cells. The proliferation capacity of cells was also inhibited by FK506, which had a greater effect on FoxP3^- cells than FoxP3⁺ cells. FK506 did inhibit the proliferation of FrIII cells, but not FrI or FrII cells. Our study provides that FK506 reduced the number of FoxP3^low CD45RA^- T cells (FrIII) by inhibiting its proliferation. Therefore, FK506 modifies Treg cells and the immune imbalance between Tregs and Th17 cells in SSc patients.

Identifying miRNA modules associated with progression of keloids through weighted gene co-expression network analysis and experimental validation in vitro

Keloid is a type of skin fibroproliferative disease, characterized by excessive deposition of collagen in the extracellular matrix, myofibroblast activation and invasive growth to the surrounding normal skin tissue. However, the specific pathogenesis of keloids is not yet fully understood and existing treatment strategies are unsatisfied. It is therefore urgent to explore new biomarkers associated with its progression for keloids. In this study, the microarray dataset GSE113620 was downloaded from the Gene Expression Omnibus (GEO) database to screen out the differential expression of miRNAs (DEMs). The DEMs with large variance were applied to construct a weighted gene co-expression network to identify miRNA modules that are closely relevant to keloid progression. It is worth noting that miR-424-3p in the blue module (r = 0.98, p = 1e-18) is considered to be the ultimate target most relevant to keloid progression through co-expressed network analysis. Subsequently, the results of molecular biology experiments determine that miR-424-3p targeting Smad7 significantly enhanced the ability of cell proliferation, migration and collagen secretion after transfection with miR-424-3p mimic, while the apoptosis rate was significantly reduced. On the contrary, the miR-424-3p inhibitor performs the exact opposite function.

CD4+ T cells and TGFβ1/MAPK signal pathway involved in the valvular hyperblastosis and fibrosis in patients with rheumatic heart disease

The aim of this study was to investigate the roles of CD4⁺ T cells and transforming growth factor beta (TGFβ1) in the pathological process of valvular hyperblastosis and fibrosis of patients with rheumatic heart disease (RHD). A total of 151 patients were enrolled, among whom, 78 patients were with RHD, and 73 were age and gender matched RHD negative patients. Blood samples and valve specimens were collected for analysis. Pathological changes and collagen fibers contents of valves were analyzed using HE and Masson staining. Percentage of peripheral blood CD4⁺ T cells was tested through flow cytometry. TGFβ1 level in serum were identified by ELISA. CD4⁺ T cells infiltration and expression of TGFβ1, p-p38, p-JNK, p-ERK in valves were detected by immunohistochemistry. The mRNA and protein levels of p38, JNK, ERK, TGFβ1, I-collagen and α-SMA were detected by qRT-PCR and western blotting, respectively. The heart valve tissues of RHD patients showed higher degrees of fibrosis, calcification and lymphocytes infiltration, which were mainly CD4⁺ T cells. In addition, compared with control group, RHD patients had more total CD4⁺ T cells in peripheral blood and valve tissues. Expression of TGFβ1, phosphorylation of JNK and p38, and synthesis of I-collagen in valve tissues of RHD patients were also significantly increased. Furthermore, we found a strong positive correlation between TGFβ1 expression and phosphorylation of JNK and p38. CD4⁺ T cells, and fibrogenic cytokine TGFβ1, which activate the intracellular MAPK signaling pathway may participate in the fibrosis of heart valve in RHD patients.

Effects of Post-administration of β-Carotene on Diet-induced Atopic Dermatitis in Hairless Mice

Atopic dermatitis (AD) is a cutaneous condition characterized by itchy, swollen, and dry skin, which is mediated by T helper cell-related cytokines. β-Carotene, a natural red pigment found in plants, exhibits antioxidant activity that has been shown to promote an inflammatory response. Because it is not clear whether β-carotene suppresses inflammation in AD skin tissues, we examined the effects of oral administration of β-carotene in mice induced by a low zinc/magnesium diet (HR-AD diet). Our studies found that AD-like inflammation was remarkably reduced by β-carotene. In addition, β-carotene significantly suppressed protein expression of TNF-α, IL-1β, and MCP-1 and mRNA expression of TSLP, IL-6, IL-1β, IL-4, IL-5, and Par-2 in AD-like skin tissues. It was also found that mRNA and protein expression of filaggrin (a major structural protein in epidermis) in AD-like skin was significantly elevated by β-carotene administration. Furthermore, β-carotene treatment significantly reduced the activity and/or mRNA expression of matrix metalloproteinases (MMPs), degradation of the extracellular matrix and regulation of chemokines. These results suggest that β-carotene reduces skin inflammation through the suppressed expression of inflammatory factors or the activity of MMPs as well as the promotion of filaggrin expression in AD-like skin. β-Carotene is a potent anti-inflammatory agent, which improves AD-like skin by enhancing the skin barrier function.

Topical Spilanthol Inhibits MAPK Signaling and Ameliorates Allergic Inflammation in DNCB-Induced Atopic Dermatitis in Mice

Atopic dermatitis (AD) is a recurrent allergic skin disease caused by genetic and environmental factors. Patients with AD may experience immune imbalance, increased levels of mast cells, immunoglobulin (Ig) E and pro-inflammatory factors (Cyclooxygenase, COX-2 and inducible NO synthase, iNOS). While spilanthol (SP) has anti-inflammatory and analgesic activities, its effect on AD remains to be explored. To develop a new means of SP, inflammation-related symptoms of AD were alleviated, and 2,4-dinitrochlorobenzene (DNCB) was used to induce AD-like skin lesions in BALB/c mice. Histopathological analysis was used to examine mast cells and eosinophils infiltration in AD-like skin lesions. The levels of IgE, IgG1 and IgG2a were measured by enzyme-linked immunosorbent assay (ELISA) kits. Western blot was used for analysis of the mitogen-activated protein kinase (MAPK) pathways and COX-2 and iNOS protein expression. Topical SP treatment reduced serum IgE and IgG2a levels and suppressed COX-2 and iNOS expression via blocked mitogen-activated protein kinase (MAPK) pathways in DNCB-induced AD-like lesions. Histopathological examination revealed that SP reduced epidermal thickness and collagen accumulation and inhibited mast cells and eosinophils infiltration into the AD-like lesions skin. These results indicate that SP may protect against AD skin lesions through inhibited MAPK signaling pathways and may diminish the infiltration of inflammatory cells to block allergic inflammation.

The long-term effect of tacrolimus on alkali burn-induced corneal neovascularization and inflammation surpasses that of anti-vascular endothelial growth factor

Purpose

To investigate the effect of tacrolimus in alkali burn-induced corneal neovascularization (NV) and inflammation and to compare with anti-vascular endothelial growth factor (anti-VEGF).

Methods

After corneal alkali-burn, 84 Wistar rats were randomly divided into three groups and received either saline solution or 0.05% tacrolimus (0.5 mg/mL) four times daily, or subconjunctival anti-VEGF injection (0.5 mg/0.05 mL). Corneal NV, opacity and epithelial defects, the status of inflammation, and the levels of proinflammatory and angiogenic cytokines were assessed on Days 3, 7, 14 and 28 post-injury.

Results

Compared with the control, tacrolimus significantly reduced corneal NV on Days 7, 14 and 28 post-injury, and anti-VEGF significantly reduced corneal NV at each assessment. Nevertheless, the tacrolimus group had significantly less corneal NV than the anti-VEGF group on Days 14 and 28. Furthermore, both tacrolimus and anti-VEGF significantly decreased the VEGF-A expression on Days 7 and 14, with no significant difference between the two groups. Moreover, corneal inflammatory response was alleviated, and corneal opacity and epithelial defects were significantly reduced by tacrolimus. Additionally, the expression of IL-1β, IL-6, monocyte chemotactic protein-1, macrophage inflammatory protein-1α and TGF-β were significantly decreased by tacrolimus.

Conclusion

Our findings suggested that 0.05% tacrolimus suspension eye drops effectively reduced alkali burn-induced corneal NV and inflammation, with a better effect than subconjunctival anti-VEGF injections on Days 14 and 28.

Mechanistic insights into topical tacrolimus for the treatment of atopic dermatitis

More than 15 years have passed since the clinical launch of topical tacrolimus for the treatment of atopic dermatitis. Its efficacy and safety have been clearly demonstrated in many global and domestic short-term and long-term clinical trials. Although the prolonged external application of steroids causes many adverse reactions including cutaneous atrophy, no such reactions occur with the use of topical tacrolimus. Therefore, the therapeutic guidelines recommend a combined topical treatment with tacrolimus and steroids. Tacrolimus is a potent immunosuppressant. However, recent studies have revealed its diverse action on the cardinal pathomechanisms of atopic dermatitis. In this review, we summarize the mechanistic role of tacrolimus in various aspects of allergic inflammation including mast cell activation, innate allergic response, pruritus, sensory nerve activation, and skin barrier dysfunction.

Site-specific gene expression profiling as a novel strategy for unravelling keloid disease pathobiology

Keloid disease (KD) is a fibroproliferative cutaneous tumour characterised by heterogeneity, excess collagen deposition and aggressive local invasion. Lack of a validated animal model and resistance to a multitude of current therapies has resulted in unsatisfactory clinical outcomes of KD management. In order to address KD from a new perspective, we applied for the first time a site-specific in situ microdissection and gene expression profiling approach, through combined laser capture microdissection and transcriptomic array. The aim here was to analyse the utility of this approach compared with established methods of investigation, including whole tissue biopsy and monolayer cell culture techniques. This study was designed to approach KD from a hypothesis-free and compartment-specific angle, using state-of-the-art microdissection and gene expression profiling technology. We sought to characterise expression differences between specific keloid lesional sites and elucidate potential contributions of significantly dysregulated genes to mechanisms underlying keloid pathobiology, thus informing future explorative research into KD. Here, we highlight the advantages of our in situ microdissection strategy in generating expression data with improved sensitivity and accuracy over traditional methods. This methodological approach supports an active role for the epidermis in the pathogenesis of KD through identification of genes and upstream regulators implicated in epithelial-mesenchymal transition, inflammation and immune modulation. We describe dermal expression patterns crucial to collagen deposition that are associated with TGFβ-mediated signalling, which have not previously been examined in KD. Additionally, this study supports the previously proposed presence of a cancer-like stem cell population in KD and explores the possible contribution of gene dysregulation to the resistance of KD to conventional therapy. Through this innovative in situ microdissection gene profiling approach, we provide better-defined gene signatures of distinct KD regions, thereby addressing KD heterogeneity, facilitating differential diagnosis with other cutaneous fibroses via transcriptional fingerprinting, and highlighting key areas for future KD research.

FK506-Binding Protein 10, a Potential Novel Drug Target for Idiopathic Pulmonary Fibrosis

RATIONALE

Increased abundance and stiffness of the extracellular matrix, in particular collagens, is a hallmark of idiopathic pulmonary fibrosis (IPF). FK506-binding protein 10 (FKBP10) is a collagen chaperone, mutations of which have been indicated in the reduction of extracellular matrix stiffness (e.g., in osteogenesis imperfecta).

OBJECTIVES

To assess the expression and function of FKBP10 in IPF.

METHODS

We assessed FKBP10 expression in bleomycin-induced lung fibrosis (using quantitative reverse transcriptase-polymerase chain reaction, Western blot, and immunofluorescence), analyzed microarray data from 99 patients with IPF and 43 control subjects from a U.S. cohort, and performed Western blot analysis from 6 patients with IPF and 5 control subjects from a German cohort. Subcellular localization of FKBP10 was assessed by immunofluorescent stainings. The expression and function of FKBP10, as well as its regulation by endoplasmic reticulum stress or transforming growth factor-β1, was analyzed by small interfering RNA-mediated loss-of-function experiments, quantitative reverse transcriptase-polymerase chain reaction, Western blot, and quantification of secreted collagens in the lung and in primary human lung fibroblasts (phLF). Effects on collagen secretion were compared with those of the drugs nintedanib and pirfenidone, recently approved for IPF.

MEASUREMENTS AND MAIN RESULTS

FKBP10 expression was up-regulated in bleomycin-induced lung fibrosis and IPF. Immunofluorescent stainings demonstrated localization to interstitial (myo)fibroblasts and CD68(+) macrophages. Transforming growth factor-β1, but not endoplasmic reticulum stress, induced FKBP10 expression in phLF. The small interfering RNA-mediated knockdown of FKBP10 attenuated expression of profibrotic mediators and effectors, including collagens I and V and α-smooth muscle actin, on the transcript and protein level. Importantly, loss of FKBP10 expression significantly suppressed collagen secretion by phLF.

CONCLUSIONS

FKBP10 might be a novel drug target for IPF.

Lysophosphatidic acid mediates fibrosis in injured joints by regulating collagen type I biosynthesis

OBJECTIVE

Articular cartilage is a highly specialized tissue which forms the surfaces in synovial joints. Full-thickness cartilage defects caused by trauma or microfracture surgery heal via the formation of fibrotic tissue characterized by a high content of collagen I (COL I) and subsequent poor mechanical properties. The goal of this study is to investigate the molecular mechanisms underlying fibrosis after joint injury.

DESIGN

Rat knee joint models were used to mimic cartilage defects after acute injury. Immunohistochemistry was performed to detect proteins related to fibrosis. Human fetal chondrocytes and bone marrow stromal cells (BMSCs) were used to study the influence of the lipid lysophosphatidic acid (LPA) on COL I synthesis. Quantitative PCR, ELISA and immunohistochemistry were performed to evaluate the production of COL I. Chemical inhibitors were used to block LPA signaling both in vitro and in vivo.

RESULTS

After full-thickness cartilage injury in rat knee joints, stromal cells migrating to the injury expressed high levels of the LPA-producing enzyme autotaxin (ATX); intact articular cartilage in rat and humans expressed negligible levels of ATX despite expressing the LPA receptors LPAR1 and LPAR2. LPA-induced increases in COL I production by chondrocytes and BMSCs were mediated by the MAP kinase and PI3 Kinase signaling pathways. Inhibition of the ATX/LPA axis significantly reduced COL I-enriched fibrocartilage synthesis in full-thickness cartilage defects in rats in favor of the collagen II-enriched normal state.

CONCLUSION

Taken together, these results identify an attractive target for intervention in reducing the progression of post-traumatic fibrosis and osteoarthritis.