Ciprofloxacin-mediated cell proliferation inhibition and G2/M cell cycle arrest in rat tendon cells

Fluoroquinolone-Mediated Tendinopathy and Tendon Rupture

The fluoroquinolone (FQ) class of antibiotics includes the world's most prescribed antibiotics such as ciprofloxacin, levofloxacin, and ofloxacin that are known for their low bacterial resistance. This is despite their potential to trigger severe side effects, such as myopathy, hearing loss, tendinopathy, and tendon rupture. Thus, healthcare organizations around the world have recommended limiting the prescription of FQs. Tendinopathy is a common name for maladies that cause pain and degeneration in the tendon tissue, which can result in tendon rupture. Whilst there are several identified effects of FQ on tendons, the exact molecular mechanisms behind FQ-mediated tendon rupture are unclear. Previous research studies indicated that FQ-mediated tendinopathy and tendon rupture can be induced by changes in gene expression, metabolism, and function of tendon resident cells, thus leading to alterations in the extracellular matrix. Hence, this review begins with an update on FQs, their mode of action, and their known side effects, as well as summary information on tendon tissue structure and cellular content. Next, how FQs affect the tendon tissue and trigger tendinopathy and tendon rupture is explored in detail. Lastly, possible preventative measures and promising areas for future research are also discussed. Specifically, follow-up studies should focus on understanding the FQ-mediated tendon changes in a more complex manner and integrating in vitro with in vivo models. With respect to in vitro systems, the field should move towards three-dimensional models that reflect the cellular diversity found in the tissue.

An In Vitro Investigation of Levofloxacin-Induced Cytotoxicity in Rat Bone Marrow Mesenchymal Stem Cells

BACKGROUND

Levofloxacin, a widely used fluoroquinolone antibiotic, has been linked to musculoskeletal complications. However, its impact on bone marrow mesenchymal stem cells (BMSCs), which are vital for tissue repair and regeneration, remains poorly understood.

AIM

This study aims to examine the impact on rat BMSCs following therapy with levofloxacin.

METHODS

 Rat BMSCs were exposed to various doses of levofloxacin (0, 14, 28, 56, 112, and 224 μM) to assess its possible cytotoxic impact on these stem cells. Cell viability was assessed using the MTT assay to evaluate the cytotoxic effects of levofloxacin. Cell apoptosis was calculated with Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) double staining, along with the expression levels of matrix metalloproteinase-3 (MMP-3), MMP-13, collagen type I alpha 1 (Col1A1), tissue inhibitor of metalloproteinase-1 (TIMP-1), and TIMP-3 messenger RNA (mRNA), which were assessed using RT-PCR. An apoptotic marker, caspase-3, was detected by immunocytochemical analysis.

RESULTS

 In certain concentrations (0-224 μM), as the concentration of levofloxacin increased, the number of apoptotic cells increased. The results demonstrated that levofloxacin significantly upregulated the mRNA levels of MMP-3 as well as MMP-13 in a dose-related manner, simultaneously downregulating TIMP-1 expression. In contrast, the expression of TIMP-3 and Col1A1 remained unaffected. In addition, the expression of caspase-3 was substantially elevated by levofloxacin in a concentration-related manner, between 28 μM and 224 μM, as indicated by immunocytochemistry.

CONCLUSION

 These findings provide evidence that levofloxacin exerts cytotoxicity on BMSCs, shown by increased apoptosis and a reduction in extracellular matrix components, highlighting a potential adverse impact of levofloxacin. Additionally, this cytotoxic effect may negatively affect fracture healing and impair the regenerative capacity of BMSCs.

Drug Utilization Evaluation Study of Ciprofloxacin Use and Adverse Events Occurrence: Role of Community Pharmacists

Background: Antimicrobial resistance is a global health crisis threatening optimal management of infectious diseases. Ciprofloxacin is a widely used fluoroquinolone in various disease conditions. Resistance against ciprofloxacin is increasing, leading to nonoptimal management of patients. Thus, the aim of this study was to assess ciprofloxacin use in the community setting in terms of appropriate prescribing, dosing, frequency, and duration of use. Methods: A cross-sectional, retrospective study was conducted by community pharmacists in 5 community pharmacies in Egypt from September 2021 to February 2022. Patients prescribed oral ciprofloxacin during the period of the study were included. Data on demographics, indications for ciprofloxacin, dosing regimen, adverse events, and drug interactions were collected. Results: A total of 151 patients' record indicated for ciprofloxacin were included in the study, of whom 44.4% were men and 55.6% were women who were neither pregnant nor lactating. Based on international guidelines, 96.69% ciprofloxacin prescriptions were appropriate; 96.03% contained correct ciprofloxacin dosing whereas 3.97% were overdose. A total of 90. 73% had correct frequency of administration and 96.03% records had correct durations. Only 1.99% of patients were ≤18 years of age, which is an absolute contraindication. Interacting drugs with ciprofloxacin were 28.5% with acetaminophen, 31.1% with ibuprofen, 16.6% with antacids, 21.2% with chlorpheniramine, and 7.9% with prednisolone. Adverse events included 1.32% hypoglycemia, 0.66% hyperglycemia, 3.97% tendinitis, and 2.65% QTc (heart rate-corrected QT interval) prolongation. Conclusion and relevance: Ciprofloxacin use in community pharmacies is appropriate according to international guidelines. Ongoing drug utilization evaluation is necessary to ensure rational drug use, which in turn can decrease resistance rates.

Oral fluoroquinolones and risk of aortic aneurysm or dissection: A nationwide population-based propensity score-matched cohort study

STUDY OBJECTIVE

To investigate risk of aortic aneurysm or dissection in patients using oral fluoroquinolones compared to those using macrolides in real-world clinical practice among a large US general population.

DESIGN

Retrospective cohort study design.

DATA SOURCE

MarketScan commercial and Medicare supplemental databases.

PATIENTS

Adults patients with at least one prescription fill for fluoroquinolone or macrolide antibiotics.

INTERVENTION

Fluoroquinolone or macrolide antibiotics.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was estimated incidence of aortic aneurysm or dissection associated with the use of fluoroquinolones compared with macrolides during a 60-day follow-up period in a 1:1 propensity score-matched cohort. We identified 3,174,620 patients (1,587,310 in each group) after 1:1 propensity score matching. Crude incidence of aortic aneurysm or dissection was 1.9 cases per 1000 person-years among fluoroquinolone users and 1.2 cases per 1000 person-years among macrolide users. In multivariable Cox regression, compared with macrolides, the use of fluoroquinolones was associated with an increased risk of aortic aneurysm or dissection (aHR: 1.34; 95% CI: 1.17-1.54). The association was primarily driven by a high incidence of aortic aneurysm cases (95.8%). Results of sensitivity (e.g., fluoroquinolone exposure ranging from 7 to 14 days (aHR: 1.47; 95% CI: 1.26-1.71)) and subgroup analyses (e.g., ciprofloxacin (aHR: 1.26; 95% CI: 1.07-1.49) and levofloxacin (aHR: 1.44; 95% CI: 1.19-1.52)) remained consistent with main findings.

CONCLUSIONS

Fluoroquinolone use was associated with a 34% increased risk of aortic aneurysm or dissection compared with macrolide use among a general US population.

Quinolone Ear Drops and Achilles Tendon Rupture

BACKGROUND

Delayed eardrum healing has been observed in the ear opposite to the ear treated with otic quinolones (OQ) in rats. Case reports describe tendinopathies after OQ treatment, suggesting adverse systemic effects.

METHODS

We studied patients aged 19 to 64 years with diagnosis of otitis externa or media in private insurance between 2005 and 2015. We compared OQ treatment against otic neomycin, oral amoxicillin, or azithromycin. Outcomes included Achilles tendon rupture (ATR), Achilles tendinitis (AT), and all-type tendon rupture (ATTR). We applied an active comparator, new-user design with 1-year look-back and ceased follow-up at initiation of systemic steroids or oral quinolones, external injury, hospitalization, and after 35 days. We used trimmed stabilized inverse probability of treatment weights to balance comparison groups in a survival framework. Negative outcomes (clavicle fractures or sports injuries) were examined to rule out differences from varied physical activity (unmeasured confounding).

RESULTS

We examined 1 501 009 treated otitis episodes. Hazard ratios (HR) for OQ exposure associated with ATR were 4.49 (95% confidence interval [CI], 1.83-11.02), AT 1.04 (95% CI, 0.73-1.50), and ATTR 1.71 (95% CI, 1.21-2.41). Weighted risk differences (RD) per 100 000 episodes for OQ exposure were ATR 7.80 (95% CI, 0.72-14.89), AT 1.01 (95% CI, -12.80 to 14.81), and ATTR 18.57 (95% CI, 3.60-33.53). Corresponding HRs for clavicle fractures and sports injuries were HR,1.71 (95% CI, 0.55-5.27) and HR,1.45 (95% CI, 0.64-3.30), suggesting limited residual confounding.

CONCLUSIONS

OQ exposure may lead to systemic consequences. Clinicians should consider this potential risk and counsel patients accordingly. Risk factors and mechanisms for this rare, adverse effect deserve further evaluation. Mechanistic and other clinical studies are warranted to corroborate this finding.

Uremic Toxins and Ciprofloxacin Affect Human Tenocytes In Vitro

Tendinopathy is a rare but serious complication of quinolone therapy. Risk factors associated with quinolone-induced tendon disorders include chronic kidney disease accompanied by the accumulation of uremic toxins. Hence, the present study explored the effects of the representative uremic toxins phenylacetic acid (PAA) and quinolinic acid (QA), both alone and in combination with ciprofloxacin (CPX), on human tenocytes in vitro. Tenocytes incubated with uremic toxins +/- CPX were investigated for metabolic activity, vitality, expression of the dominant extracellular tendon matrix (ECM) protein type I collagen, cell-matrix receptor β1-integrin, proinflammatory interleukin (IL)-1β, and the ECM-degrading enzyme matrix metalloproteinase (MMP)-1. CPX, when administered at high concentrations (100 mM), suppressed tenocyte metabolism after 8 h exposure and at therapeutic concentrations after 72 h exposure. PAA reduced tenocyte metabolism only after 72 h exposure to very high doses and when combined with CPX. QA, when administered alone, led to scarcely any cytotoxic effect. Combinations of CPX with PAA or QA did not cause greater cytotoxicity than incubation with CPX alone. Gene expression of the pro-inflammatory cytokine IL-1β was reduced by CPX but up-regulated by PAA and QA. Protein levels of type I collagen decreased in response to high CPX doses, whereas PAA and QA did not affect its synthesis significantly. MMP-1 mRNA levels were increased by CPX. This effect became more pronounced in the form of a synergism following exposure to a combination of CPX and PAA. CPX was more tenotoxic than the uremic toxins PAA and QA, which showed only distinct suppressive effects.

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.

Effect of Ciprofloxacin on Susceptibility to Aortic Dissection and Rupture in Mice

Importance

Fluoroquinolones are among the most commonly prescribed antibiotics. Recent clinical studies indicated an association between fluoroquinolone use and increased risk of aortic aneurysm and dissection (AAD). This alarming association has raised concern, especially in patients with AAD with risk of rupture and in individuals at risk for developing AAD.

Objective

To examine the effect of ciprofloxacin on AAD development in mice.

Design, Setting, and Participants

In a mouse model of moderate, sporadic AAD, 4-week-old male and female C57BL/6J mice were challenged with a high-fat diet and low-dose angiotensin infusion (1000 ng/min/kg). Control unchallenged mice were fed a normal diet and infused with saline. After randomization, challenged and unchallenged mice received ciprofloxacin (100 mg/kg/d) or vehicle through daily gavage during angiotensin or saline infusion. Aortic aneurysm and dissection development and aortic destruction were compared between mice. The direct effects of ciprofloxacin on aortic smooth muscle cells were examined in cultured cells.

Results

No notable aortic destruction was observed in unchallenged mice that received ciprofloxacin alone. Aortic challenge induced moderate aortic destruction with development of AAD in 17 of 38 mice (45%) and severe AAD in 9 (24%) but no rupture or death. However, challenged mice that received ciprofloxacin had severe aortic destruction and a significantly increased incidence of AAD (38 of 48 [79%]; P = .001; χ2 = 10.9), severe AAD (32 of 48 [67%]; P < .001; χ2 = 15.7), and rupture and premature death (7 of 48 [15%]; P = .01; χ2 = 6.0). The increased AAD incidence was observed in different aortic segments and was similar between male and female mice. Compared with aortic tissues from challenged control mice, those from challenged mice that received ciprofloxacin showed decreased expression of lysyl oxidase, an enzyme that is critical in the assembly and stabilization of elastic fibers and collagen. These aortas also showed increased matrix metalloproteinase levels and activity, elastic fiber fragmentation, and aortic cell injury. In cultured smooth muscle cells, ciprofloxacin treatment significantly reduced lysyl oxidase expression and activity, increased matrix metalloproteinase expression and activity, suppressed cell proliferation, and induced cell death. Furthermore, ciprofloxacin-a DNA topoisomerase inhibitor-caused nuclear and mitochondrial DNA damage and the release of DNA into the cytosol, subsequently inducing mitochondrial dysfunction, reactive oxygen species production, and activation of the cytosolic DNA sensor STING, which we further showed was involved in the suppression of lysyl oxidase expression and induction of matrix metalloproteinase expression.

Conclusions and Relevance

Ciprofloxacin increases susceptibility to aortic dissection and rupture in a mouse model of moderate, sporadic AAD. Ciprofloxacin should be used with caution in patients with aortic dilatation, as well as in those at high risk for AAD.

Stimulatory effects of fibroblast growth factor 2 on proliferation and migration of uterine luminal epithelial cells during early pregnancy

Fibroblast growth factor 2 (FGF2) is a mitogen that induces proliferation, differentiation, and migration of cells, as well as angiogenesis and carcinogenesis via autocrine or paracrine actions. Fibroblast growth factor 2 expression is abundant in porcine conceptuses and endometrium during the estrous cycle and peri-implantation period of pregnancy. However, its intracellular actions in uterine epithelial cells have not been reported. The results of this study indicated abundant expression of FGFR1 and FGFR2 predominantly in uterine luminal and glandular epithelia during early pregnancy and that their expression decreased with increasing parity of the sows. Treatment of porcine uterine luminal epithelial (pLE) cells with FGF2 increased proliferation and DNA replication based on increases in proliferating cell nuclear antigen (PCNA) and initiation of G1/S phase progression. In addition, FGF2 increases phosphorylation of AKT, P70S6K, S6, ERK1/2, JNK, P38, and P90RSK in a time-dependent manner, and increases in their expression was suppressed by Wortmannin (a phosphatidylinositol 3-kinase [PI3K] inhibitor), U0126 (an ERK1/2 inhibitor), SP600125 (a JNK inhibitor), and SB203580 (a P38 inhibitor) based on western blot analyses. Also, the abundance of cytoplasmic p-AKT protein was decreased by Wortmannin and U0126, and p-ERK1/2 protein was reduced only by U0126. Furthermore, inhibition of each signal transduction protein reduced the ability of FGF2 to stimulate proliferation and migration of pLE cells. Collectively, these results indicate that activation of FGFR1 and FGFR2 by uterine- and endometrial-derived FGF2 stimulates PI3K/AKT and mitogen-activated protein kinase pathways for development of the porcine uterus and improvement of litter size.

New antiproliferative 7-(4-(N-substituted carbamoylmethyl)piperazin-1-yl) derivatives of ciprofloxacin induce cell cycle arrest at G2/M phase

New N-4-piperazinyl derivatives of ciprofloxacin 2a-g were prepared and tested for their cytotoxic activity. The primary in vitro one dose anticancer assay experienced promising cytotoxic activity against different cancer cell lines especially non-small cell lung cancer. Independently, compounds 2b, 2d, 2f and 2g showed anticancer activity against human non-small cell lung cancer A549 cells (IC50=14.8, 24.8, 23.6 and 20.7μM, respectively) compared to the parent ciprofloxacin (IC50 >100μM) and doxorubicin as a positive control (IC50=1μM). The flow cytometric analysis for 2b showed dose dependent G2/M arrest in A549 cells. Also, 2b increased the expression of p53 and p21 and decreased the expression of cyclin B1 and Cdc2 proteins in A549 cells without any effect on the same proteins expression in WI-38 cells. Specific inhibition of p53 by pifithrin-α reversed the G2/M phase arrest induced by the 2b compound, suggesting contribution of p53 to increase. Taken together, 2b induced G2/M phase arrest via p53/p21 dependent pathway. The results indicate that 2b can be used as a lead compound for further development of new derivatives against non-small cell lung cancer.

Prevention of Simvastatin-Induced Inhibition of Tendon Cell Proliferation and Cell Cycle Progression by Geranylgeranyl Pyrophosphate

Statins have been reported to induce tendinopathy and even tendon rupture. The present study was designed to investigate the potential molecular mechanism underlying the adverse effect of simvastatin on tendon cells. An in vitro tendon healing model was performed using tendon cells isolated from rat Achilles tendons. The viability of tendon cells and cell cycle progression were examined by the MTT assay and flow cytometric analysis, respectively. Immunofluorescent staining for Ki-67 was used to assess the proliferation activity of tendon cells. Western blot analysis and coimmunoprecipitation was used to determine the protein expression of cell cycle-related proteins. To investigate the potential mechanism underlying the effect of statins on tendon cells, mevalonate, farnesyl pyrophosphate (FPP), or geranylgeranyl pyrophosphate (GGPP) was added to simvastatin-treated tendon cells. Simvastatin inhibited the in vitro tendon healing model and tendon cell proliferation in a dose-dependent manner. Immunofluorescent staining demonstrated reduced ki-67 expression in simvastatin-treated tendon cells. Furthermore, simvastatin induced cell cycle arrest at the G1 phase. The expression levels of cdk1, cdk2, cyclin A, and cyclin E were downregulated by simvastatin in a dose-dependent manner. The inhibitory effect of simvastatin was proved to mediate the reduction of mevalonate, and the addition of exogenous GGPP completely prevented the inhibitory effect of simvastatin on tendon cells. The present study demonstrated, for the first time, the molecular mechanism underlying simvastatin-induced tendinopathy or tendon rupture. GGPP was shown to prevent the adverse effect of simvastatin in tendon cells without interfering with its cholesterol-reducing efficacy.

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.

Fluoroquinolones and tendinopathy: a guide for athletes and sports clinicians and a systematic review of the literature

CONTEXT

Fluoroquinolone antibiotics have been used for several decades and are effective antimicrobials. Despite their usefulness as antibiotics, a growing body of evidence has accumulated in the peer-reviewed literature that shows fluoroquinolones can cause pathologic lesions in tendon tissue (tendinopathy). These adverse effects can occur within hours of commencing treatment and months after discontinuing the use of these drugs. In some cases, fluoroquinolone usage can lead to complete rupture of the tendon and substantial subsequent disability.

OBJECTIVE

To discuss the cause, pharmacology, symptoms, and epidemiology of fluoroquinolone-associated tendinopathy and to discuss the clinical implications with respect to athletes and their subsequent physiotherapy.

DATA SOURCES

We searched MEDLINE, Cumulative Index to Nursing and Allied Health (CINAHL), Allied and Complementary Medicine Database (AMED), and SPORTDiscus databases for available reports of fluoroquinolone-related tendinopathy (tendinitis, tendon pain, or rupture) published from 1966 to 2012. Search terms were fluoroquinolones or quinolones and tendinopathy, adverse effects, and tendon rupture. Included studies were written in or translated into English. Non-English-language and non-English translations of abstracts from reports were not included (n = 1).

STUDY SELECTION

Eligible studies were any available reports of fluoroquinolone-related tendinopathy (tendinitis, tendon pain, or rupture). Both animal and human histologic studies were included. Any papers not focusing on the tendon-related side effects of fluoroquinolones were excluded (n = 71).

DATA EXTRACTION

Data collected included any cases of fluoroquinolone-related tendinopathy, the particular tendon affected, type of fluoroquinolone, dosage, and concomitant risk factors. Any data outlining the adverse histologic effects of fluoroquinolones also were collected.

DATA SYNTHESIS

A total of 175 papers, including 89 case reports and 8 literature reviews, were identified.

CONCLUSIONS

Fluoroquinolone tendinopathy may not respond well to the current popular eccentric training regimes and may require an alternative, staged treatment approach. Clinicians, athletes, athletic trainers, and their medical support teams should be aware of the need to discuss and possibly discontinue these antibiotics if adverse effects arise.

Ciprofloxacin has antifibrotic effects in scleroderma fibroblasts via downregulation of Dnmt1 and upregulation of Fli1

Systemic sclerosis (SSc) is characterized by fibrosis of the skin and internal organs. The present study was undertaken to examine the effects of ciprofloxacin, a fluoroquinolone antibiotic implicated in matrix remodeling, on dermal and lung fibroblasts obtained from SSc patients. Dermal and lung fibroblasts from SSc patients and healthy subjects were treated with ciprofloxacin. Western blotting was used to analyze protein levels and RT-PCR was used to measure mRNA expression. The pharmacologic inhibitor UO126 was used to block Erk1/2 signaling. SSc dermal fibroblasts demonstrated a significant decrease in collagen type I mRNA and protein levels after antibiotic treatment, while healthy dermal fibroblasts were less sensitive to ciprofloxacin, downregulating collagen only at the protein levels. Connective tissue growth factor (CCN2) gene expression was significantly reduced and matrix metalloproteinase 1 (MMP1) levels were enhanced after ciprofloxacin treatment to a similar extent in healthy and SSc fibroblasts. Ciprofloxacin induced Erk1/2 phosphorylation, and Erk1/2 blockade completely prevented MMP1 upregulation. However, Smad1 and Smad3 activation in response to TGFβ was not affected. The expression of friend leukemia integration factor 1 (Fli1), a transcriptional repressor of collagen, was increased after treatment with ciprofloxacin only in SSc fibroblasts, and this was accompanied by a decrease in the levels of DNA methyltransferase 1 (Dnmt1). Similar effects were observed in SSc-interstitial lung disease (ILD) lung fibroblasts. In summary, our study demonstrates that ciprofloxacin has antifibrotic actions in SSc dermal and lung fibroblasts via the downregulation of Dnmt1, the upregulation of Fli1 and induction of MMP1 gene expression via an Erk1/2-dependent mechanism. Thus, our data suggest that ciprofloxacin may be an attractive therapy for SSc skin and lung fibrosis.

Fluoroquinolone-mediated inhibition of cell growth, S-G2/M cell cycle arrest, and apoptosis in canine osteosarcoma cell lines

Despite significant advancements in osteosarcoma research, the overall survival of canine and human osteosarcoma patients has remained essentially static over the past 2 decades. Post-operative limb-spare infection has been associated with improved survival in both species, yet a mechanism for improved survival has not been clearly established. Given that the majority of canine osteosarcoma patients experiencing post-operative infections were treated with fluoroquinolone antibiotics, we hypothesized that fluoroquinolone antibiotics might directly inhibit the survival and proliferation of canine osteosarcoma cells. Ciprofloxacin or enrofloxacin were found to inhibit p21(WAF1) expression resulting in decreased proliferation and increased S-G(2)/M accumulation. Furthermore, fluoroquinolone exposure induced apoptosis of canine osteosarcoma cells as demonstrated by cleavage of caspase-3 and PARP, and activation of caspase-3/7. These results support further studies examining the potential impact of quinolones on survival and proliferation of osteosarcoma.

The effect of aging on migration, proliferation, and collagen expression of tenocytes in response to ciprofloxacin

Quinolone-induced tendinopathy or tendon rupture tends to be age-related. However, the synergistic effects of quinolone and aging on tenocytes remained to be explored. Tenocytes intrinsic to rat Achilles tendon from two age groups (young: 2 months; and near senescent (old): 24 months) were treated with ciprofloxacin. Tenocyte migration and proliferation were assessed by transwell filter migration assay and MTT (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay, respectively. Messenger RNA and protein expressions of types I and III collagen were determined by reverse transcription-polymerase chain reaction (RT/PCR) and Western blot analysis, respectively. Transwell filter migration assay revealed that ciprofloxacin inhibited tenocytes migration, which became more significant in old tenocytes (p < 0.05). The results of MTT assay revealed that tenocytes proliferation decreased after ciprofloxacin treatment (p < 0.05), which also became more significant in old tenocytes. The results of RT-PCR and Western blot analysis revealed that mRNA and protein expressions of type I collagen remained unchanged in either young or old tenocytes with ciprofloxacin treatment, whereas the expressions of type III collagen were down-regulated by ciprofloxacin, which was more significant in old tenocytes. In conclusion, aging potentiated the ciprofloxacin-mediated inhibition of migration, proliferation, and expression of type III collagen of tenocytes.

Efficiency of Plasmocin™ on various mammalian cell lines infected by mollicutes in comparison with commonly used antibiotics in cell culture: a local experience

Mycoplasma contamination is a deleterious event for cell culture laboratories. Plasmocin™ is used to prevent and eradicate mycoplasma infections from cell. In this study, 80 different mammalian cell lines from various sources; human, monkey, mice, hamster and rat were used to study and evaluate plasmocin™ efficiency and compare it to commonly used antibiotics such as BM-cyclin, ciprofloxacin and mycoplasma removal agent (MRA). It was shown that mycoplasma infections were eradicated by plasmocin™, BM-cyclin, ciprofloxacin and MRA in 65%, 66.25%, 20%, and 31.25%, respectively, of infected cell cultures. However, re-infection with mycoplasmas after the period of 4 months occurred in 10-80% of the studied cell lines. Cell cytotoxicity and culture death was observed in 25, 17.5 and 10% of the treated cells, for plasmocin™, BM-cyclin and MRA, respectively. In this study, Plasmocin™ showed strong ability to eradicate mollicutes from our cell lines with minimal percentage of regrowth. However, due to its high cell cytotoxicity it should be used with caution especially when dealing with expensive or hard-to-obtain cell lines. Amongst the antibiotics tested, BM-cyclin was shown to remove mycoplasma with the highest efficiency.

Ciprofloxacin up-regulates tendon cells to express matrix metalloproteinase-2 with degradation of type I collagen

Ciprofloxacin-induced tendinopathy and tendon rupture have been previously described, principally affecting the Achilles tendon. This study was designed to investigate the effect of ciprofloxacin on expressions of matrix metalloproteinases (MMP)-2 and -9, tissue inhibitors of metalloproteinase (TIMP)-1 and -2 as well as type I collagen in tendon cells. Tendon cells intrinsic to rat Achilles tendon were treated with ciprofloxacin and then underwent MTT (tetrazolium) assay. Real-time reverse-transcription polymerase chain reaction (RT-PCR) and Western blot analysis were used, respectively, to evaluate the gene and protein expressions of type I collagen, and MMP-2. Gelatin zymography was used to evaluate the enzymatic activities of MMP-2 and -9. Reverse zymography was used to evaluate TIMP-1 and -2. Immunohistochemical staining for MMP-2 in ciprofloxacin-treated tendon explants was performed. Collagen degradation was evaluated by incubation of conditioned medium with collagen. The results revealed that ciprofloxacin up-regulated the expression of MMP-2 in tendon cells at the mRNA and protein levels. Immunohistochemistry also confirmed the increased expressions of MMP-2 in ciprofloxacin-treated tendon explants. The enzymatic activity of MMP-2 was up-regulated whereas that of MMP-9, TIMP-1 or TIMP-2 was unchanged. The amount of secreted type I collagen in the conditioned medium decreased and type I collagen was degraded after ciprofloxacin treatment. In conclusion, ciprofloxacin up-regulates the expressions of MMP-2 in tendon cells and thus degraded type I collagen. These findings suggest a possible mechanism of ciprofloxacin-associated tendinopathy.