Systemic mesalazine treatment prevents spontaneous skin fibrosis in PLK2-deficient mice

Radiation-induced morphea of the breast - characterization and treatment of fibroblast dysfunction with repurposed mesalazine

Radiation-induced morphea (RIM) is a rare complication of radiotherapy presenting as inflammatory fibrosis, most commonly reported in breast cancer patients. As underlying disease mechanisms are not well understood, targeted therapies are lacking. Since fibroblasts are the key mediators of all fibroproliferative diseases, this study aimed to characterize patient-derived fibroblasts to identify therapeutic targets. We studied primary human control and RIM-fibroblasts on a functional and molecular basis, analyzed peripheral blood and tissue samples and conducted, based on our findings, a treatment attempt in one patient. In RIM, we identified a distinct myofibroblast phenotype reflected by increased alpha-smooth-muscle-actin (αSMA) expression, reduced proliferation and migration rates, and overexpression of osteopontin (OPN). Our RNA sequencing identified aberrant Myc activation as a potential disease driver in RIM fibroblasts, similar to previous findings in systemic sclerosis. Treatment with the anti-inflammatory drug mesalazine reversed the myofibroblast phenotype by targeting Myc. Based on these findings, a patient with RIM was successfully treated with mesalazine, resulting in reduced inflammation and pain and tissue softening, while serum OPN was halved. The present study provides a comprehensive characterization of RIM fibroblasts, suggests a disease-driving role for Myc, demonstrates promising antifibrotic effects of mesalazine and proposes OPN as a biomarker for RIM.

[Radiation-induced morphea-an overview]

BACKGROUND

Radiation-induced morphea is a fibro-inflammatory remodelling process of the subcutaneous connective tissue caused by ionising radiation, most commonly in the context of breast cancer treatment. The underlying pathomechanisms and putative risk factors are unknown. Therefore, misdiagnosis and inappropriate treatment pose a significant problem in the care of those patients.

OBJECTIVES

The aim of the study was to provide an overview as well as guidance for the diagnosis and treatment of radiation-induced morphea based on current case reports and review articles.

RESULTS AND CONCLUSIONS

Radiation-induced morphea is a rare condition that represents an interdisciplinary challenge for (gynaecological) oncology, radiotherapy and dermatology. Frequent misdiagnoses include infection (erysipelas), cancer recurrence or radiation dermatitis. Early histological diagnosis and the initiation of anti-inflammatory therapy using topical glucocorticoids or calcineurin inhibitors in combination with phototherapy and/or methotrexate are the most relevant success factors for an adequate clinical response.

A real-world disproportionality analysis of mesalazine data mining of the public version of FDA adverse event reporting system

Background: Mesalazine, a preparation of 5-aminosalicylic acid, is a medication widely used in clinical practice as a first-line therapy in the treatment of mild and moderate inflammatory bowel disease. However, the long-term safety of mesalazine in large sample population was unknown. The current study was to assess mesalazine -related adverse events of real-world through data mining of the US Food and Drug Administration Adverse Event Reporting System (FAERS). Methods: Disproportionality analyses, including the reporting odds ratio (ROR), the proportional reporting ratio the Bayesian confidence propagation neural network and the multi-item gamma Poisson shrinker (MGPS) algorithms were employed to quantify the signals of mesalazine -associated AEs. Results: Out of 14,149,980 reports collected from the FDA Adverse Event Reporting System database, 24,284 reports of mesalazine -associated AEs were identified. A total of 170 significant disproportionality preferred terms conforming to the four algorithms simultaneously were retained. The most common AEs included colitis ulcerative, diarrhoea, condition aggravated, crohn's disease, fatigue, abdominal pain, nausea, haematochezia, which were corresponding to those reported in the specification and clinical trials. Unexpected significant AEs as dizziness, drug ineffective, drug hypersensitivity, infection, off label use, weight decreased, decreased appetite, arthralgia, rash might also occur. The median onset time of mesalazine -related AEs was 1,127 days (interquartile range [IQR] 1,127-1,674 days), and most of the cases occurred 2 years later (n = 610, 70.93%) and within the first 1 month (n = 89, 10.35%) after mesalazine initiation. Conclusion: Results of our study were consistent with clinical observations. We also found potential new and unexpected AEs signals for mesalazine, suggesting prospective clinical studies were needed to confirm these results and illustrate their relationship. Our results could provide valuable evidence for further safety studies of mesalazine.

The critical role of osteopontin (OPN) in fibrotic diseases

Fibrosis is a pathological condition characterized by the excessive deposition of extracellular matrix components in tissues and organs, leading to progressive architectural remodelling and contributing to the development of various diseases. Osteopontin (OPN), a highly phosphorylated glycoprotein, has been increasingly recognized for its involvement in the progression of tissue fibrosis. This review provides a comprehensive overview of the genetic and protein structure of OPN and focuses on our current understanding of the role of OPN in the development of fibrosis in the lungs and other tissues. Additionally, special attention is given to the potential of OPN as a biomarker and a novel therapeutic target in the treatment of fibrosis.

Investigation of mesalazine as an antifibrotic drug following myocardial infarction in male mice

OBJECTIVES

Myocardial infarction (MI) initiates a complex reparative response during which damaged cardiac muscle is replaced by connective tissue. While the initial repair is essential for survival, excessive fibrosis post-MI is a primary contributor to progressive cardiac dysfunction, and ultimately heart failure. Currently, there are no approved drugs for the prevention or the reversal of cardiac fibrosis. Therefore, we tested the therapeutic potential of repurposed mesalazine as a post-MI therapy, as distinct antifibrotic effects have recently been demonstrated.

METHODS

At 8 weeks of age, MI was induced in male C57BL/6J mice by LAD ligation. Mesalazine was administered orally at a dose of 100 μg/g body weight in drinking water. Fluid intake, weight development, and cardiac function were monitored for 28 days post intervention. Fibrosis parameters were assessed histologically and via qPCR.

RESULTS

Compared to controls, mesalazine treatment offered no survival benefit. However, no adverse effects on heart and kidney function and weight development were observed, either. While total cardiac fibrosis remained largely unaffected by mesalazine treatment, we found a distinct reduction of perivascular fibrosis alongside reduced cardiac collagen expression.

CONCLUSIONS

Our findings warrant further studies on mesalazine as a potential add-on therapy post-MI, as perivascular fibrosis development was successfully prevented.

Extracellular matrix stiffness-The central cue for skin fibrosis

Skin fibrosis is a physiopathological process featuring the excessive deposition of extracellular matrix (ECM), which is the main architecture that provides structural support and constitutes the microenvironment for various cellular behaviors. Recently, increasing interest has been drawn to the relationship between the mechanical properties of the ECM and the initiation and modulation of skin fibrosis, with the engagement of a complex network of signaling pathways, the activation of mechanosensitive proteins, and changes in immunoregulation and metabolism. Simultaneous with the progression of skin fibrosis, the stiffness of ECM increases, which in turn perturbs mechanical and humoral homeostasis to drive cell fate toward an outcome that maintains and enhances the fibrosis process, thus forming a pro-fibrotic "positive feedback loop". In this review, we highlighted the central role of the ECM and its dynamic changes at both the molecular and cellular levels in skin fibrosis. We paid special attention to signaling pathways regulated by mechanical cues in ECM remodeling. We also systematically summarized antifibrotic interventions targeting the ECM, hopefully enlightening new strategies for fibrotic diseases.

Polo-Like Kinase 2: From Principle to Practice

Polo-like kinase (PLK) 2 is an evolutionarily conserved serine/threonine kinase that shares the n-terminal kinase catalytic domain and the C-terminal Polo Box Domain (PBD) with other members of the PLKs family. In the last two decades, mounting studies have focused on this and tried to clarify its role in many aspects. PLK2 is essential for mitotic centriole replication and meiotic chromatin pairing, synapsis, and crossing-over in the cell cycle; Loss of PLK2 function results in cell cycle disorders and developmental retardation. PLK2 is also involved in regulating cell differentiation and maintaining neural homeostasis. In the process of various stimuli-induced stress, including oxidative and endoplasmic reticulum, PLK2 may promote survival or apoptosis depending on the intensity of stimulation and the degree of cell damage. However, the role of PLK2 in immunity to viral infection has been studied far less than that of other family members. Because PLK2 is extensively and deeply involved in normal physiological functions and pathophysiological mechanisms of cells, its role in diseases is increasingly being paid attention to. The effect of PLK2 in inhibiting hematological tumors and fibrotic diseases, as well as participating in neurodegenerative diseases, has been gradually recognized. However, the research results in solid organ tumors show contradictory results. In addition, preliminary studies using PLK2 as a disease predictor and therapeutic target have yielded some exciting and promising results. More research will help people better understand PLK2 from principle to practice.