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Cells Nov 2023is gaining recognition and importance as an organismic model for toxicity testing in line with the 3Rs principle (replace, reduce, refine). In this study, we explored...
is gaining recognition and importance as an organismic model for toxicity testing in line with the 3Rs principle (replace, reduce, refine). In this study, we explored the use of to examine the toxicities of alkylating sulphur mustard analogues, specifically the monofunctional agent 2-chloroethyl-ethyl sulphide (CEES) and the bifunctional, crosslinking agent mechlorethamine (HN2). We exposed wild-type worms at different life cycle stages (from larvae L1 to adulthood day 10) to CEES or HN2 and scored their viability 24 h later. The susceptibility of to CEES and HN2 paralleled that of human cells, with HN2 exhibiting higher toxicity than CEES, reflected in LC values in the high µM to low mM range. Importantly, the effects were dependent on the worms' developmental stage as well as organismic age: the highest susceptibility was observed in L1, whereas the lowest was observed in L4 worms. In adult worms, susceptibility to alkylating agents increased with advanced age, especially to HN2. To examine reproductive effects, L4 worms were exposed to CEES and HN2, and both the offspring and the percentage of unhatched eggs were assessed. Moreover, germline apoptosis was assessed by using ::GFP (MD701) worms. In contrast to concentrations that elicited low toxicities to L4 worms, CEES and HN2 were highly toxic to germline cells, manifesting as increased germline apoptosis as well as reduced offspring number and percentage of eggs hatched. Again, HN2 exhibited stronger effects than CEES. Compound specificity was also evident in toxicities to dopaminergic neurons-HN2 exposure affected expression of dopamine transporter DAT-1 (strain BY200) at lower concentrations than CEES, suggesting a higher neurotoxic effect. Mechanistically, nicotinamide adenine dinucleotide (NAD) has been linked to mustard agent toxicities. Therefore, the NAD-dependent system was investigated in the response to CEES and HN2 treatment. Overall NAD levels in worm extracts were revealed to be largely resistant to mustard exposure except for high concentrations, which lowered the NAD levels in L4 worms 24 h post-treatment. Interestingly, however, mutant worms lacking components of NAD-dependent pathways involved in genome maintenance, namely , , and showed a higher and compound-specific susceptibility, indicating an active role of NAD in genotoxic stress response. In conclusion, the present results demonstrate that represents an attractive model to study the toxicology of alkylating agents, which supports its use in mechanistic as well as intervention studies with major strength in the possibility to analyze toxicities at different life cycle stages.
Topics: Animals; Humans; Alkylating Agents; Caenorhabditis elegans; NAD; Life Cycle Stages
PubMed: 38067156
DOI: 10.3390/cells12232728 -
Experimental and Molecular Pathology Jun 2020Nitrogen mustard (NM) is a highly reactive bifunctional alkylating agent that induces inflammation, edema and blistering in skin. An important mechanism mediating the...
Nitrogen mustard (NM) is a highly reactive bifunctional alkylating agent that induces inflammation, edema and blistering in skin. An important mechanism mediating the action of NM and related mustards is oxidative stress. In these studies a modified murine patch-test model was used to analyze DNA damage and the antioxidant/stress response following NM exposure in isolated epidermis. NM (20 μmol) was applied to glass microfiber filters affixed to a shaved dorsal region of skin of CD-1 mice. NM caused structural damage to the stratum corneum as reflected by increases in transepidermal water loss and skin hydration. This was coordinate with edema, mast cell degranulation and epidermal hyperplasia. Within 3 h of NM exposure, a 4-fold increase in phosphorylated histone H2AX, a marker of DNA double-stranded breaks, and a 25-fold increase in phosphorylated p53, a DNA damage marker, were observed in the epidermis. This was associated with a 40% increase in 8-oxo-2'-deoxyguanosine modified DNA in the epidermis and a 4-fold increase in 4-hydroxynonenal modified epidermal proteins. At 12 h post NM, there was a 3-75 fold increase in epidermal expression of antioxidant/stress proteins including heme oxygenase-1, thioredoxin reductase, superoxide dismutase, glutathione reductase, heat shock protein 27 and cyclooxygenase 2. These data indicate that NM induces early oxidative epidermal injury in mouse skin leading to an antioxidant/stress response. Agents that enhance this response may be useful in mitigating mustard-induced skin injury.
Topics: Alkylating Agents; Animals; Antioxidants; Apoptosis; Cyclooxygenase 2; DNA Damage; Epidermis; Glutathione Reductase; HSP27 Heat-Shock Proteins; Heme Oxygenase-1; Humans; Inflammation; Mechlorethamine; Mice; Oxidative Stress; Phosphorylation; Skin; Stress, Physiological; Superoxide Dismutase; Thioredoxin-Disulfide Reductase
PubMed: 32113906
DOI: 10.1016/j.yexmp.2020.104410 -
Toxicology Letters Jun 2020Mustard vesicants, including sulfur mustard (2,2'-dichlorodiethyl sulfide, SM) and nitrogen mustard (bis(2-chloroethyl)methylamine, HN2) are cytotoxic blistering agents...
Mustard vesicants, including sulfur mustard (2,2'-dichlorodiethyl sulfide, SM) and nitrogen mustard (bis(2-chloroethyl)methylamine, HN2) are cytotoxic blistering agents synthesized for chemical warfare. Because they contain highly reactive electrophilic chloroethyl side chains, they readily react with cellular macromolecules like DNA forming monofunctional and bifunctional adducts. By targeting DNA, mustards can compromise genomic integrity, disrupt the cell cycle, and cause mutations and cytotoxicity. To protect against genotoxicity following exposure to mustards, cells initiate a DNA damage response (DDR). This involves activation of signaling cascades including ATM (ataxia telangiectasia mutated), ATR (ataxia telangiectasia and Rad3-related) and DNA-PKcs (DNA-dependent protein kinase, catalytic unit). Signaling induced by the DDR leads to the recruitment and activation of repair related proteins such as phospho H2AX and phospho p53 to sites of DNA lesions. Excessive DNA modifications by mustards can overwhelm DNA repair leading to single and double strand DNA breaks, cytotoxicity and tissue damage, sometimes leading to cancer. Herein we summarize DDR signaling pathways induced by SM, HN2 and the half mustard, 2-chloroethyl ethyl sulfide (CEES). At the present time, little is known about how mustard-induced DNA damage leads to the activation of DDR signaling. A better understanding of mechanisms by which mustard vesicants induce the DDR may lead to the development of countermeasures effective in mitigating tissue injury.
Topics: Cell Survival; DNA Damage; Humans; Mechlorethamine; Mustard Gas; Mustard Plant; Signal Transduction
PubMed: 32173488
DOI: 10.1016/j.toxlet.2020.03.008 -
Cells Jun 2023Sulfur mustard gas (SM) is a vesicating and alkylating agent used as a chemical weapon in many mass-casualty incidents since World War I. Ocular injuries were reported...
Sulfur mustard gas (SM) is a vesicating and alkylating agent used as a chemical weapon in many mass-casualty incidents since World War I. Ocular injuries were reported in >90% of exposed victims. The mechanisms underlying SM-induced blindness remain elusive. This study tested the hypothesis that SM-induced corneal fibrosis occurs due to the generation of myofibroblasts from resident fibroblasts via the SMAD2/3 signaling pathway in rabbit eyes in vivo and primary human corneal fibroblasts (hCSFs) isolated from donor corneas in vitro. Fifty-four New Zealand White Rabbits were divided into three groups (Naïve, Vehicle, SM-Vapor treated). The SM-Vapor group was exposed to SM at 200 mg-min/m3 for 8 min at the MRI Global facility. Rabbit corneas were collected on day 3, day 7, and day 14 for immunohistochemistry, RNA, and protein lysates. SM caused a significant increase in SMAD2/3, pSMAD, and ɑSMA expression on day 3, day 7, and day 14 in rabbit corneas. For mechanistic studies, hCSFs were treated with nitrogen mustard (NM) or NM + SIS3 (SMAD3-specific inhibitor) and collected at 30 m, 8 h, 24 h, 48 h, and 72 h. NM significantly increased TGFβ, pSMAD3, and SMAD2/3 levels. On the contrary, inhibition of SMAD2/3 signaling by SIS3 treatment significantly reduced SMAD2/3, pSMAD3, and ɑSMA expression in hCSFs. We conclude that SMAD2/3 signaling appears to play a vital role in myofibroblast formation in the cornea following mustard gas exposure.
Topics: Humans; Animals; Rabbits; Mustard Gas; Myofibroblasts; Chemical Warfare Agents; Cornea; Mechlorethamine; Signal Transduction; Smad2 Protein
PubMed: 37296653
DOI: 10.3390/cells12111533 -
Toxicology and Applied Pharmacology Feb 2022Nitrogen mustard (NM) is an analogue of the potent vesicating agent sulfur mustard, with well-established ocular injury models in rabbit eyes to study vesicant-induced...
Nitrogen mustard (NM) is an analogue of the potent vesicating agent sulfur mustard, with well-established ocular injury models in rabbit eyes to study vesicant-induced ocular toxicity. The effects of NM-exposure to eyes may include irritation, redness, inflammation, fibrosis, epithelial degradation, blurred vision, partial/complete blindness, which may be temporary or permanent, depending on the route, duration, and dosage of exposure. Effective countermeasures against vesicant exposure are presently not available and are warranted in case of any terrorist activity or accidental leakage from stockpiles. Herein, our focus was to evaluate whether dexamethasone (DEX), an FDA approved potent corticosteroid with documented anti-inflammatory activities, could be an effective treatment modality. Accordingly, utilizing NM-induced corneal injuries in rabbit ocular in vivo model, we examined and compared the efficacy of DEX treatments when administration was started at early (2 h), intermediate (4 h), and late (6 h) therapeutic windows of intervention after NM-exposure and administered every 8 h thereafter. The effects of NM-exposure and DEX treatments were evaluated on clinical (corneal opacity, ulceration, and neovascularization), biological (epithelial thickness, epithelial-stromal separation, blood vessels density, and inflammatory cell and keratocyte counts) and molecular (COX-2 and VEGF expression) parameters, at day 1, 3, 7 and 14. Results indicated that DEX treatment markedly and effectively reversed the NM-induced injury markers in rabbit corneas. Early administration of DEX at 2 h was found to be most effective in reversing NM-induced corneal injuries, followed by DEX 4 h and DEX 6 h administration initiation, indicating that DEX has best efficacy at the early therapeutic window in our study model.
Topics: Animals; Anti-Inflammatory Agents; Biomarkers; Corneal Injuries; Dexamethasone; Irritants; Male; Mechlorethamine; Rabbits
PubMed: 35108561
DOI: 10.1016/j.taap.2022.115904 -
Toxicological Sciences : An Official... Dec 2019Nitrogen mustard (NM) is a vesicant known to target the lung, causing acute injury which progresses to fibrosis. Evidence suggests that activated macrophages contribute...
Nitrogen mustard (NM) is a vesicant known to target the lung, causing acute injury which progresses to fibrosis. Evidence suggests that activated macrophages contribute to the pathologic response to NM. In these studies, we analyzed the role of lung lipids generated following NM exposure on macrophage activation and phenotype. Treatment of rats with NM (0.125 mg/kg, i.t.) resulted in a time-related increase in enlarged vacuolated macrophages in the lung. At 28 days postexposure, macrophages stained positively for Oil Red O, a marker of neutral lipids. This was correlated with an accumulation of oxidized phospholipids in lung macrophages and epithelial cells and increases in bronchoalveolar lavage fluid (BAL) phospholipids and cholesterol. RNA-sequencing and immunohistochemical analysis revealed that lipid handling pathways under the control of the transcription factors liver-X receptor (LXR), farnesoid-X receptor (FXR), peroxisome proliferator-activated receptor (PPAR)-ɣ, and sterol regulatory element-binding protein (SREBP) were significantly altered following NM exposure. Whereas at 1-3 days post NM, FXR and the downstream oxidized low-density lipoprotein receptor, Cd36, were increased, Lxr and the lipid efflux transporters, Abca1 and Abcg1, were reduced. Treatment of naïve lung macrophages with phospholipid and cholesterol enriched large aggregate fractions of BAL prepared 3 days after NM exposure resulted in upregulation of Nos2 and Ptgs2, markers of proinflammatory activation, whereas large aggregate fractions prepared 28 days post NM upregulated expression of the anti-inflammatory markers, Il10, Cd163, and Cx3cr1, and induced the formation of lipid-laden foamy macrophages. These data suggest that NM-induced alterations in lipid handling and metabolism drive macrophage foam cell formation, potentially contributing to the development of pulmonary fibrosis.
Topics: Animals; Bronchoalveolar Lavage Fluid; Cholesterol; Foam Cells; Lung; Macrophage Activation; Macrophages, Alveolar; Male; Mechlorethamine; Phospholipids; Pulmonary Fibrosis; Rats, Wistar
PubMed: 31428777
DOI: 10.1093/toxsci/kfz187 -
Frontiers in Medicine 2023Cutaneous adverse events of both topical and systemic drugs in patients with mycosis fungoides (MF) present a diagnostic challenge as it is often difficult to...
Cutaneous adverse events of both topical and systemic drugs in patients with mycosis fungoides (MF) present a diagnostic challenge as it is often difficult to distinguish drug associated rash from disease progression in the skin. Mogamulizumab and mechlorethamine gel are approved treatments for MF, both of which can cause treatment related cutaneous adverse events. It can often be challenging to distinguish mogamulizumab associated rash (MAR) and mechlorethamine gel associated hypersensitivity dermatitis from MF progression both clinically and histologically. High-throughput sequencing (HTS) of the T-cell receptor (TCR), also known as immunosequencing, can be used to assess T-cell clonality to support a diagnosis of MF. After identification of the malignant TCR clone at baseline, immunosequencing can track the established malignant TCR sequence and its frequency over time with high sensitivity. As a result, immunosequencing clone tracking can aid in distinguishing disease progression from treatment side effects. Here, we present a case series to demonstrate how monitoring of the malignant T-cell frequency by immunosequencing can aid in diagnosis of mogamulizumab and mechlorethamine gel cutaneous adverse events.
PubMed: 38164221
DOI: 10.3389/fmed.2023.1243459 -
World Journal of Clinical Oncology Sep 2021The outcomes of Hodgkin´s lymphoma (HL) in México have not been widely reported. Simplified and affordable treatments have been adopted in middle-income countries.
BACKGROUND
The outcomes of Hodgkin´s lymphoma (HL) in México have not been widely reported. Simplified and affordable treatments have been adopted in middle-income countries.
AIM
The aim was to evaluate long-used therapies for HL in México in a long-term basis.
METHODS
In a 34-year time period, 88 patients with HL were treated at a single institution in México. Patients were treated with adriamycin bleomycin vinblastine and dacarbazine (ABVD) or mechlorethamine, vincristine, procarbazine, and prednisone (MOPP). Relapsed or refractory patients were given ifosfamide, carboplatin, and etoposide (ICE) followed by autologous or allogeneic stem cell transplants.
RESULTS
Thirty-seven women and 51 men were included; the median age was 29 years. Patients were followed for a mean of 128 mo. The 310-mo overall survival (OS) was 83% for patients treated with MOPP and 88% for those treated with ABVD. The OS of patients who received autologous stem cell transplantation was 76% (330 mo) 93% (402 mo) in those who did not.
CONCLUSION
HL may be less aggressive in Mexican population than in Caucasians. Combined chemotherapy renders acceptable results, regardless of clinical stage.
PubMed: 34631443
DOI: 10.5306/wjco.v12.i9.800 -
American Journal of Clinical Dermatology Jul 2022Chlormethine gel was approved for treatment of mycosis fungoides, the most common cutaneous T-cell lymphoma, on the basis of results from study 201 and study 202. A...
BACKGROUND
Chlormethine gel was approved for treatment of mycosis fungoides, the most common cutaneous T-cell lymphoma, on the basis of results from study 201 and study 202. A post-hoc analysis of study 201 found interesting trends regarding improved efficacy of chlormethine gel vs ointment and noted a potential association between dermatitis and clinical response.
OBJECTIVE
To expand these results by performing a post-hoc analysis of study 202.
PATIENTS AND METHODS
Patients received chlormethine gel or ointment during study 201 (12 months) and higher-concentration chlormethine gel during study 202 (7-month extension). Response was assessed using Composite Assessment of Index Lesion Severity (CAILS). Associations between treatment frequency, response, and skin-related adverse events (AEs) were assessed using multivariate time-to-event analyses. Time-to-response and repeated measures analyses were compared between patients who only used chlormethine gel and those who switched from ointment to gel.
RESULTS
No associations were seen between treatment frequency and improved skin response (CAILS) or AE occurrence within the 201/202 study populations. However, an association was observed specifically between contact dermatitis and improved CAILS response at the next visit (p < 0.0001). Patients who used chlormethine gel during both studies had a significantly (p < 0.05) shorter time to response and higher overall response rates than patients who initiated treatment with ointment.
CONCLUSIONS
This post-hoc analysis shows that patients who initiated treatment using chlormethine gel had faster and higher responses compared with patients who initially used chlormethine ointment for 12 months. The development of contact dermatitis may be a potential prognostic factor for response.
TRIAL REGISTRATION NUMBERS AND DATES OF REGISTRATION
Study 201: NCT00168064, September 14, 2002; Study 202: NCT00535470, September 26, 2007.
Topics: Clinical Trials as Topic; Dermatitis, Contact; Gels; Humans; Mechlorethamine; Mycosis Fungoides; Ointments; Skin Neoplasms; Treatment Outcome
PubMed: 35536441
DOI: 10.1007/s40257-022-00687-y -
Clinical and Translational Medicine Feb 2021Nitrogen mustard (NM) causes severe skin injury with an obvious inflammatory response, which is lack of effective and targeted therapies. Vitamin D3 (VD3) has excellent...
Nitrogen mustard (NM) causes severe skin injury with an obvious inflammatory response, which is lack of effective and targeted therapies. Vitamin D3 (VD3) has excellent anti-inflammatory properties and is considered as a potential candidate for the treatment of NM-induced dermal toxicity; however, the underlying mechanisms are currently unclear. Cyclooxygenase-2 (COX2; a widely used marker of skin inflammation) plays a key role in NM-induced cutaneous inflammation. Herein, we initially confirmed that NM markedly promoted COX2 expression in vitro and in vivo. NM also increased NOD-like receptor family pyrin domain containing 3 (NLRP3) expression, caspase-1 activity, and interleukin-1β (IL-1β) release. Notably, treatment with a caspase-1 inhibitor (zYVAD-fmk), NLRP3 inhibitor (MCC950), and NLRP3 or caspase-1 siRNA attenuated NM-induced NLRP3 inflammasome activation, with subsequent suppression of COX2 expression and IL-1β release in keratinocytes. Meanwhile, NM increased mitochondrial reactive oxygen species (mtROS) and decreased manganese superoxide dismutase 2 (SOD2) and sirtuin 3 (SIRT3) activities. Mito-TEMPO (a mtROS scavenger) ameliorated NM-caused NLRP3 inflammasome activation in keratinocytes. Moreover, VD3 improved SIRT3 and SOD2 activities, decreased mtROS contents, inactivated the NLRP3 inflammasome, and attenuated cutaneous inflammation induced by NM in vitro and in vivo. The beneficial activity of VD3 against NM-triggered cutaneous inflammation was enhanced by the inhibitors of IL-1, mtROS, NLRP3, caspase-1, and NLRP3 or caspase-1 siRNAs, which was abolished in SIRT3 inhibitor or SIRT3 siRNA-treated keratinocytes and skins from SIRT3 mice. In conclusion, VD3 ameliorated NM-induced cutaneous inflammation by inactivating the NLRP3 inflammasome, which was partially mediated through the SIRT3-SOD2-mtROS signaling pathway.
Topics: Animals; Dermatitis, Contact; Female; HaCaT Cells; Humans; Inflammasomes; Keratinocytes; Mechlorethamine; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitochondria; NLR Family, Pyrin Domain-Containing 3 Protein; Reactive Oxygen Species; Signal Transduction; Sirtuin 3; Superoxide Dismutase; Vitamin D
PubMed: 33634989
DOI: 10.1002/ctm2.312