The effects of levofloxacin on rabbit fibroblast-like synoviocytes in vitro

Extracellular matrix in synovium development, homeostasis and arthritis disease

Extracellular matrix (ECM) is a three-dimensional network entity composed of extracellular macromolecules. ECM in synovium not only supports the structural integrity of synovium, but also plays a crucial role in regulating homeostasis and damage repair response in synovium. Obvious disorders in the composition, behavior and function of synovial ECM will lead to the occurrence and development of arthritis diseases such as rheumatoid arthritis (RA), osteoarthritis (OA) and psoriatic arthritis (PsA). Based on the importance of synovial ECM, targeted regulation of the composition and structure of ECM is considered to be an effective measure for the treatment of arthritis disease. This paper reviews the current research status of synovial ECM biology, discusses the role and mechanism of synovial ECM in physiological status and arthritis disease, and summarizes the current strategies for targeting synovial ECM to provide information for the pathogenesis, diagnosis and treatment of arthritis disease.

Achilles Tendon Rupture Associated with the Use of Fluoroquinolones in Patients Over 60 Years of AGE: Experience From a Single Tertiary Centre

BACKGROUND

Fluoroquinolones have been associated with increased risk of tendinopathy and Achilles tendon rupture (ATR), especially in patients over 60 years of age.

METHODS

A retrospective study was carried out including patients over 60 years of age with ATR attended in our centre over the period 2000-2017.

RESULTS

We identified 44 patients with RTA, of whom 18% (8/44) had been previously treated with fluoroquinolones, with a mean age at diagnosis of ATR of 77.37 years and concomitant corticotherapy in 4 of them. In 7patients, the rupture was spontaneous and all required surgical management. A significantly higher frequency of smoking, concomitant corticotherapy and spontaneous ruptures were found in the group treated with fluoroquinolones.

CONCLUSIONS

ATR is an adverse event that can occur in patients over 60 years of age treated with fluoroquinolones, so an adequate risk-benefit assessment should be carried out in this population, especially in the presence of associated risk factors.

Biological and chemical changes in fluoroquinolone-associated tendinopathies: a systematic review

INTRODUCTION

The present systematic review investigates the biological and chemical mechanisms that affect the health and structure of tendons following the use of fluoroquinolones (FQs).

SOURCES OF DATA

A total of 12 articles were included, organized, and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

AREAS OF AGREEMENT

Five mechanisms were identified: arrest of proliferation through a decreased activity of cyclin B, CDK-1, CHK-1, and increased PK-1; decrease tenocytes migration through decreased phosphorylation of FAK; decrease type I collagen metabolism through increased MMP-2; chelate effect on ions that influence epigenetics and several enzymes; fluoroquinolones-induced ROS (radical oxygen species) production in mitochondria.

AREAS OF CONTROVERSY

There is no definite structure-damage relationship. The dose-effect relationship is unclear.

GROWING POINTS

Knowing and defining the damage exerted by FQs plays a role in clinical practice, replacing FQs with other antibacterial drugs or using antioxidants to attenuate their pathological effects.

AREAS TIMELY FOR DEVELOPING RESEARCH

Clinical and basic sciences studies for each FQs are necessary.

Cytotoxicity of Ciprofloxacin and Steroids in Mouse Tympanic Membrane Fibroblasts

Objective

Ciprofloxacin, commonly given as eardrops, has been shown to adversely affect tympanic membrane fibroblasts. Dexamethasone potentiates this effect. A newly available eardrop contains ciprofloxacin and fluocinolone, a more potent steroid. We evaluated the cytotoxic effects of this preparation on mouse tympanic membrane fibroblasts.

Study Design

Prospective, in vitro.

Setting

Academic laboratory.

Subjects and Methods

In experiment 1, fibroblasts were exposed to 1:10 dilutions of commercially available 0.3% ofloxacin, 0.3% ciprofloxacin, 0.3% ciprofloxacin + 0.1% dexamethasone, 0.3% ciprofloxacin + 0.025% fluocinolone, or dilute hydrochloric acid (control), twice within 24 hours. In experiment 2, cells were also treated with the dilutions of the pure form of dexamethasone 0.1% or fluocinolone 0.025%, alone and in combination with ofloxacin or ciprofloxacin. Cells were exposed to the solutions for 2 hours each time and were placed back in growth media after the treatments. Cells were observed with phase-contrast microscope until the cytotoxicity assay was performed.

Results

Survival of fibroblasts treated with ofloxacin was not different from the control. Fibroblasts treated with ciprofloxacin, ciprofloxacin + dexamethasone, or ciprofloxacin + fluocinolone had much lower survival (all P < .0001). Cells treated with ciprofloxacin + fluocinolone had lower survival than ciprofloxacin ( P < .0001) and ciprofloxacin + dexamethasone ( P = .0001). Steroids alone also decreased fibroblast survival compared to control ( P < .0001). The combination of dexamethasone or fluocinolone with ciprofloxacin, but not ofloxacin, further decreased fibroblast survival ( P < .0001). Phase-contrast images mirrored the cytotoxicity findings.

Conclusion

Tympanic membrane fibroblast cytotoxicity of ciprofloxacin is potentiated by corticosteroids. This effect may be deleterious when treating a healing perforation but beneficial when treating granulation tissue on the tympanic membrane.

Regulatory effects of zinc on cadmium-induced cytotoxicity in chronic inflammation

OBJECTIVES

Zinc (Zn) has major effects on immune system activation while Cadmium (Cd) has anti-inflammatory and anti-proliferative effects in several chronic inflammatory contexts. The aim of this work was to investigate by which mechanisms Zn could compete with Cd and eventually counteract its deleterious effects. Rheumatoid arthritis (RA) synoviocytes exposed to cytokines were used as a model of chronic inflammation; osteoarthritis (OA) synoviocytes were used as control.

METHODS

Cell/medium fractionation constants were analyzed for different metals by inductively-coupled-plasma mass-spectrometry by comparison to the 70Zn spike. Interleukin-17 (IL-17) and tumor necrosis factor-alpha (TNF-α) were used to mimic inflammation. Gene expression of ZIP-8 importer, metallothioneins-1 (MT-1s) and the ratio between metalloprotease-3 and the tissue inhibitor of metalloproteinases (MMP-3)/TIMP-1) were evaluated after pre-exposure to cytokines and Cd, with or without the addition of exogenous Zn (0.9 ppm). Cell viability was measured by neutral red assay and IL-6 production by ELISA.

RESULTS

Synoviocytes selectively absorbed and retained Cd in comparison to Zn. Metal import increased with IL-17/TNF-α exposure, through the enhanced ZIP-8 expression. Zn did not modify ZIP-8 expression, while Cd reduced it (p<0.05). Zn induced a reduction of Cd-induced MT-1s expression, in particular of MT-1X (3-fold), and subsequently the final intra-cellular content of Cd. By reducing Cd accumulation in cells, Zn reversed Cd anti-proliferative and anti-inflammatory effects but preserved the low MMP-3/TIMP-1 ratio induced by Cd, which was enhanced by inflammatory conditions.

CONCLUSION

Zinc counteracts the deleterious effect of Cd by reducing its import and accumulation in the cell, without the reactivation of destructive pathways such as MMPs.

Drugs affecting glycosaminoglycan metabolism

Glycosaminoglycans (GAGs) are charged polysaccharides ubiquitously present at the cell surface and in the extracellular matrix. GAGs are crucial for cellular homeostasis, and their metabolism is altered during pathological processes. However, little consideration has been given to the regulation of the GAG milieu through pharmacological interventions. In this review, we provide a classification of small molecules affecting GAG metabolism based on their mechanism of action. Furthermore, we present evidence to show that clinically approved drugs affect GAG metabolism and that this could contribute to their therapeutic benefit.

Ciprofloxacin Decreases Collagen in Mouse Tympanic Membrane Fibroblasts

Objectives

To determine how collagen production by tympanic membrane fibroblasts is affected by ciprofloxacin at levels found in eardrops.

Study Design

Prospective, controlled, and blinded cell culture study.

Setting

Academic tertiary medical center.

Subjects

Cell culture of mouse fibroblasts.

Methods

A primary fibroblast culture was established from mouse tympanic membranes. Fibroblasts were cultured until they were 75% confluent, then treated with dilute hydrochloric acid (control) or ciprofloxacin (0.01% or 0.3%) for 24 or 72 hours for Western blotting and for 24 or 48 hours for cytotoxicity assay. Cells were observed with phase-contrast microscope. Western blotting was performed for collagen type 1 α1 (collagen 1A1) and α-tubulin.

Results

Fibroblasts treated with 0.01% and 0.3% ciprofloxacin for 24 hours had lower levels of collagen 1A1 ( P = .0005 and P < .0001, respectively) and α-tubulin (both P < .0001) than control fibroblasts. Collagen 1A1 and α-tubulin levels were lower in fibroblasts treated with 0.3% than with 0.01% ciprofloxacin ( P = .02 and P = .014). After 72 hours, 0.3% ciprofloxacin completely eliminated collagen 1A1 and α-tubulin ( P < .001). Cells treated with 0.01% ciprofloxacin for 72 hours also had lower collagen 1A1 ( P < .0001) and α-tubulin ( P = .005) as compared with the control. Seventy-two-hour incubation in 0.01% or 0.3% ciprofloxacin resulted in lower levels of collagen 1A1 ( P = .009 and P < .0001, respectively) and α-tubulin ( P = .007 and P < .0001, respectively) than 24-hour incubation. Cytotoxicity assay and phase-contrast microscopy mirrored these findings.

Conclusions

Treatment of tympanic membrane fibroblasts with 0.3% ciprofloxacin, as found in eardrops, reduces fibroblast viability and collagen and α-tubulin protein levels. These findings could explain tympanic membrane healing problems associated with quinolone eardrops.

Toxic effects of levofloxacin on rat annulus fibrosus cells: an in-vitro study

BACKGROUND

Fluoroquinolones are in wide clinical use as safe and effective antibiotics. Articular cartilage, tendons, and epiphyseal growth plates have been recognized as targets of fluoroquinolone-induced connective tissue toxicity. However, the effects of fluoroquinolones on annulus fibrosus (AF) cells are still unknown.

MATERIAL/METHODS

The main objective of this study was to investigate the effects of levofloxacin, a typical fluoroquinolone antibiotic drug, on rat AF cells in vitro. Rat annulus fibrosus (RAF) cells were treated with levofloxacin at different concentrations (0, 10, 20, 30, 40, 60, 80, and 90 μg/ml) and were assessed to determine the possible cytotoxic effects of levofloxacin. Inverted phase-contrast microscopy was used to accomplish the morphological observation of apoptosis of treated cells. Western blot and real-time quantitative RT-PCR (qPCR) was used to explore the expression of active caspase-3 and MMP-3. Flow cytometry was used to measure the apoptotic incidences.

RESULTS

Our study showed that levofloxacin, with concentrations at 30, 60, and 90 μg/ml, induced dose-dependent RAF cell apoptosis and higher expression of caspase-3 and MMP-3. More apoptotic cells were observed by inverted phase-contrast microscopy. Moreover, levofloxacin increased the activity of caspase-3, and it also reduced cell viability with different concentrations ranging from 10 to 80 μg/ml.

CONCLUSIONS

Our study results suggest that levofloxacin has cytotoxic effects on RAF cells, characterized by enhancing apoptosis and reducing cell viability, and indicate a potential toxic effect of fluoroquinolones on RAF cells.

Levofloxacin increases the effect of serum deprivation on anoikis of rat nucleus pulposus cells via Bax/Bcl-2/caspase-3 pathway

Levofloxacin, a fluoroquinolone, is a widely-used and effective antibiotic. However, various adverse side effects are associated with levofloxacin. The purpose of this study was to further explore the effects of levofloxacin on rat nucleus pulposus cells (NPCs). Inverted phase-contrast microscopy, flow cytometry and caspase-3 activity assays were used and revealed that serum deprivation induced apoptosis, which was markedly increased by levofloxacin in a dose-dependent manner. Simultaneously, levofloxacin decreased cell binding to type II collagen (COL2). Thus, levofloxacin-induced apoptosis exhibits characteristics of anoikis, the process by which cell death is triggered by separation from the extracellular matrix, which contains COL2. Furthermore, real-time quantitative RT-PCR was used to further confirm that levofloxacin downregulates COL2 expression in a dose-dependent manner. At last, western blot was used to find that levofloxacin increased the ratio of Bax/Bcl-2 and active caspase-3 in a dose-dependent manner. Levofloxacin therefore increases the effects of serum deprivation on anoikis by downregulating COL2 in rat NPCs in vitro via Bax/Bcl-2/caspase-3 pathway. This research provides a novel insight into the mechanisms of levofloxacin-induced toxicity and may potentially lead to a better understanding of the clinical effects of levofloxacin, especially in terms of intervertebral disc degeneration.