High-dose methotrexate and zanubrutinib combination therapy for primary central nervous system lymphoma

In this editorial I comment on the article,published in the current issue of the World Journal of Clinical Oncology.Primary central nervous system lymphoma(PCNSL)is a disease of elderly and immunocompromised patients.The authors reported clinical results of 19 patients with PCNSL treated with zanubrutinib/high dose methotrexate(HD-MTX)until disease progression.They demonstrated that the combination of zanubrutinib with HD-MTX led to a marked clinical response and tolerability among these patients.They also observed that cerebrospinal fluid liquid biopsy to detect circulating tumor DNA may be a good option for evaluating treatment response and tumor burden in patients with PCNSL.PCNSL is a challenging disease for treatment as these patients present with different neurological states and comorbidities.Treatment has evolved over the years from whole brain radiotherapy to HD-MTX followed by autologous stem cell transplant.Gradually,treatment of patients with PCNSL is going to become individualized.

Status of Renal and Liver Function in Rheumatoid Arthritis (RA) Patients of Chattogram, Bangladesh Treated with Methotrexate (MTX)

Rheumatoid Arthritis (RA) is a chronic autoimmune disorder that is usually manifested as inflammation in multiple joints and several extra-articular symptoms, involving the liver, kidney, eye, skin, blood, blood vessels, heart, lungs, nervous system, and other organs. Methotrexate (MTX) is the anchor drug that treats RA. As renal and liver abnormalities are more common during disease conditions as well as during the treatment period, we tried to find out if there is any impact of MTX in these organs during the treatment of RA patients. Once the disease complications are developed, it is quite difficult to reverse the disease, and treatment in this situation is not very effective. Consequently, patients suffer a lot. So, early evaluation of renal and liver function is essential for the treatment of RA patients and it might also help prevent different complications which are usually very frequently observed. This was a cross-sectional study. A total of 150 RA patients treated with MTX were evaluated for the study where female and male respondents were 115 and 35 respectively. In this study, we found that 82% of RA patients had creatinine levels ≤ 1.1 mg/dL although the normal range of serum creatinine is below 1.4 mg/dL. Usually, a 15% increase in Serum creatinine level from the baseline is considered renal impairment. We found 4% of such cases. Moreover, 2% of RA patients had creatinine levels above the normal range of 1.4 mg/dL and those patients were hypertensive as well. So, a total (4 + 2 = 6)% had renal impairments. Among them, 5% had diabetes mellitus. On the other hand, the ultrasonogram (USG) of RA patients with kidney disease showed signs of renal parenchymal disease and 3% of RA patients having renal problems whose serum creatinine level was within the normal range showed signs of chronic kidney disease (CKD). On the other hand, 2% of RA patients showed signs of hepatic parenchymal disease. In this study, 69% of RA patients had ALT levels ≤ 50 mg/dL, 23% had 50 - 100 mg/dL, and 5% had 101 - 150 mg/dL. The remaining 3% of RA patients had ALT levels above 150 mg/dL. All those patients with ALT levels above 100 mg/dL used Nonsteroidal anti-inflammatory drugs (NSAIDs) concomitantly. Different parameters of liver and renal function should be monitored strongly in RA patients treated with MTX and NSAIDs. MTX should not be given for a prolonged period without monitoring renal and liver function. As MTX, Diabetes Mellitus, Hypertension, etc., may cause renal complications, we could not concretely conclude which one is the actual causative agent.

Bovine Serum Albumin (BSA) Microspheres Containing Methotrexate (MTX) I.Pharmaceutical Aspects

Microspheres Ⅰ,Ⅱ and Ⅲ were produced by emulsion technique.Microsphere I was solidified by glutaraldehyde crosslinking,microsphere Ⅱ was solidified by glutaraldehyde crosslinking and further treated with glycine solution and microsphere Illwas solidified by heating denaturation only.The results showed that the microsphere diameter produced by cross[inking was bigger than that prepared by heating.The microsphere Ⅱ had higher hydrophilicity than Microsphere I had.The methotrexate (MTX) contents in microspheres Ⅰ and Ⅱ were 2.73±0.053%,2.87±0.119% respectively. microsphere Ⅲ was only blank microspheres with MTX adsorbed on their surfaces.In vitro release studies,microspheres I and I have maintained sustained release of MTX till the next day,it was found that the drug releases from microspheres Ⅰ and Ⅱ were governed by Higuchi diffusion law.

清肠温中方含药血清调控NLRP6途径对Caco-2/HT29-MTX细胞共培养模型MUC2表达的影响

目的:研究清肠温中方含药血清调控NLRP6途径影响Caco-2/HT29-MTX细胞共培养模型MUC2分泌的作用机制。方法:使用SD大鼠制备清肠温中方含药血清;Caco-2/HT29-MTX细胞共培养构建单层肠上皮细胞模型;IL-1β刺激共培养细胞模拟体外肠道炎症模型;si-NLRP6质粒转染干扰NLRP6,研究清肠温中方作用机制。qPCR检测NLRP6、IL-18的mRNA表达水平;Western blot检测NLRP6、IL-18蛋白表达水平;免疫荧光染色观察MUC2表达。结果:正常培养的Caco-2/HT29-MTX细胞中,NLRP6敲除后,MUC2表达明显减少。清肠温中方含药血清增加IL-1β诱导的细胞炎症模型中NLRP6和IL-18 mRNA及蛋白表达水平(P<0.05,P<0.01),且一定程度上抵消si-NLRP6的抑制作用。与模型组相比,清肠温中方含药血清干预后,促进MUC2蛋白表达恢复,si-NLRP6后一定程度上削弱了清肠温中方的作用。结论:清肠温中方含药血清通过调控NLRP6信号途径,进一步调节MUC2分泌,修复UC黏液屏障损伤。

ICG-MTX合成水凝胶光热转化性能表征及保健护理应用

为了改善水凝胶在保健护理中的应用效果,研究制备了吲哚菁绿-甲氨蝶呤(ICG-MTX)和ICGMTX@PPA Gel水凝胶,考察了水凝胶的显微形貌、光热稳定性、光热转化效率、体外细胞毒性等。结果表明,ICG-MTX主要呈球形,粒径分布为100~300 nm;ICG与MTX可实现自组装且ICG-MTX在水凝胶中的释放是一个均匀缓慢的过程。ICG和ICG-MTX的光热转换效率分别为26.7%和34.9%,ICG-MTX相较ICG具有更高的光热转化效率。随着处理时间的延长,5组试样中细胞存活率整体会逐渐减小;在相同处理时间下,ICG-MTX@Gel相较其他非对照组有更高的细胞存活率,而ICG-MTX@Gel+Laser条件下的细胞存活率最小,表明ICG-MTX@Gel具有良好的生物活性,有望在保健护理中应用。

经阴道B超引导下胚胎减灭术联合MTX治疗在特殊类型异位妊娠中的应用

目的探讨经阴道B超引导下胚胎减灭术联合氨甲蝶呤(MTX)在特殊类型异位妊娠中的临床应用价值。方法收集38例特殊类型异位妊娠患者,15例患者接受经阴道超声引导下减灭异位妊娠胚胎联合孕囊局部注射MTX治疗(A组),23例患者接受保守手术治疗(B组)。回顾性分析2组患者的临床资料,并比较2种方法的治疗结局。结果A组13例治疗成功,成功率为86.67%;1例输卵管妊娠术后2 d输卵管妊娠破裂急诊手术行输卵管切除术,1例输卵管妊娠术后3 d因腹痛进行急诊手术,术中提示输卵管妊娠流产。2组患者术前HCG水平,术后1周HCG水平及治疗后HCG下降水平比较差异无统计学意义(P>0.05)。A组治疗费用明显低于B组(P<0.05)。结论经阴道超声引导下胚胎减灭术联合孕囊局部注射MTX是一种治疗特殊类型异位妊娠的行之有效的方法。

糖皮质激素联合MTX和单纯激素治疗中重度活动期甲状腺相关眼病的比较研究

目的观察静脉激素冲击联合甲氨蝶呤(MTX)和单纯静脉冲击在治疗中重度活动期甲状腺相关眼病(TAO)中的作用,对比二者的有效性和安全性。方法前瞻性随机对照研究。入组患者随机分为两组:联合治疗组为4.5 g静脉激素冲击方案+口服MTX,单纯激素组为4.5 g静脉激素冲击方案+口服安慰剂;于第6周和第12周评价两组的眼部体征和全身情况,记录总体有效率和不良反应发生率。结果本研究纳入53例中重度活动期TAO患者,联合治疗组22例,第6周和第12周的总体有效率分别为68.2%和81.8%;单纯治疗组23例,第6周和第12周的总体有效率分别为56.5%和73.9%,两组总体有效率均无统计学差异(P=0.542,P=0.722),联合治疗组肝功能异常的比例较单纯治疗组高,差异有统计学意义。结论激素联合MTX治疗中重度活动期TAO患者有效,可更有效降低临床活动性评分(CAS),提高视力,改善突眼度,总体有效率与单纯静脉冲击无统计学差异;联合MTX可能存在更大的肝毒性。

Analytical methodologies for determination of methotrexate and its metabolites in pharmaceutical,biological and environmental samples

Methotrexate(MTX)is a folate antagonist drug used for several diseases,such as cancers,various malignancies,rheumatoid arthritis(RA)and inflammatory bowel disease.Due to its structural features,including the presence of two carboxylic acid groups and its low native fluorescence,there are some challenges to develop analytical methods for its determination.MTX is metabolized to 7-hydroxymethotrexate(7-OH-MTX),2,4-diamino-N10-methylpteroic acid(DAMPA),and the active MTX polyglutamates(MTXPGs)in the liver,intestine,and red blood cells(RBCs),respectively.Additionally,the drug has a narrow therapeutic range;hence,its therapeutic drug monitoring(TDM)is necessary to regulate the pharmacokinetics of the drug and to decrease the risk of toxicity.Due to environmental toxicity of MTX;its sensitive,fast and low cost determination in workplace environments is of great interest.A large number of methodologies including high performance liquid chromatography equipped with UVevisible,fluorescence,or electrochemical detection,liquid chromatography-mass spectroscopy,capillary electrophoresis,UVevisible spectrophotometry,and electrochemical methods have been developed for the quantitation of MTX and its metabolites in pharmaceutical,biological,and environmental samples.This paper will attempt to review several published methodologies and the instrumental conditions,which have been applied to measure MTX and its metabolites within the last decade.

Risk of liver disease in methotrexate treated patients

Methotrexate is the first line drug treatment for anumber of rheumatic and non-rheumatic diseases. It is effective in controlling disease activity and preventing disease-related damage, and significantly cheaper than many alternatives. Use in rheumatoid arthritis infers a significant morbidity and mortality benefit. Methotrexate is generally well tolerated but can cause symptomatic adverse events. Multiple serious adverse events have been attributed to methotrexate, based largely on older reports using high or daily doses, and subsequent case reports and circumstantial evidence. The risk with modern dosing regimens: Lower doses, weekly schedules, and concomitant folic acid is less clear. Clarification and dissemination of the actual risk is crucial so appropriate judgements can be made for patients who may benefit from this treatment. Methotrexate has been associated with a range of liver related adverse events ranging from asymptomatic transaminase elevations to fibrosis and fatal hepatic necrosis. Concern over potential liver toxicity has resulted in treatment avoidance, cessation, or recommendations for investigations which may be costly, invasive and unwarranted. Modern laboratory monitoring of liver blood tests may also influence the risk of more serious complications. The majority of present day studies report an approximate doubling of the relative risk of elevated transaminases in methotrexate treated patients but no increased risk of symptomatic or severe liver related adverse events. In this article we will review the evidence around methotrexate and liver related adverse events.

Use of methotrexate in inflammatory bowel disease in 2014: A User's Guide

Methotrexate has been used an immunomodulator in many autoimmune diseases,including inflammatory bowel disease. However,many physicians are unfamiliar or uncomfortable with its use in the management of inflammatory bowel disease. We summarize the data for use of methotrexate in common clinical scenarios:(1) steroid dependant Crohn's disease(CD);(2) maintenance of remission in steroid free CD;(3) azathioprine failures in CD;(4) in combination therapy with Anti-TNF agents in CD;(5) decreasing antibody formation to Anti-TNF therapy in CD;(6) management of fistulizing disease in CD; and(7) as well as induction and maintenance of remission in ulcerative colitis. An easy to use algorithm is provided for the busy clinician to access and safely prescribe methotrexate for their inflammatory bowel disease patients.

Cytoprotective effects of amifostine,ascorbic acid and N-acetylcysteine against methotrexate-induced hepatotoxicity in rats

AIM: To investigate the potential role of oxidative stress and the possible therapeutic effects of N-acetyl cysteine (NAC), amifostine (AMF) and ascorbic acid (ASC) in methotrexate (MTX)-induced hepatotoxicity.

Protective effects of Balanites aegyptiaca extract, melatonin and ursodeoxycholic acid against hepatotoxicity induced by methotrexate in male rats

Objective: To compare the degree of ameliorative effects of Melatonin(MEL), Ursodeoxycholic acid(UDCA) and Balanites aegyptiaca(BA) against hepatotoxicity induced by MTX for one month. Methods: Eighty adult male rats(Sprague Dawely) weighing(190±10g), were randomly divided into eight equal groups: Control, MTX, MEL, BA, UDCA, MTX+MEL, MTX+BA, MTX+UDCA. Liver function biomarker enzymes, liver tissue oxidative stress parameters, together with total antioxidant capacity and tumor necrosis factor(TNF-α) were determined. Histopathological and immunohistochemistry examinations for TNF-α were also done. Results: MTX showed significant increase in alanine transaminase(ALT), aspartate transaminase(AST), alkaline phosphatase(ALP), gamma glutamyl transferase(GGT), total and direct bilirubin, as well as TNF-α levels, oxidized glutathione(GSSG), malodialdehyde(MDA) and nitric oxide(NO). whereas, total protein, albumin, total antioxidant capacity, reduced glutathione(GSH), glutathione peroxidase(GPx), glutathione reductase(GR), glutathione S-transferase(GST), superoxide dismutase(SOD) and catalase(CAT) levels were significantly decreased in MTX treated group. These alterations were improved by MEL and BA treatment, whereas no improvement was noticed in UDCA treatment. Conclusions: BA may be as promising as MEL in the hepatoprotection against MTX toxicity through their antioxidant and radical scavenging activities. In addition, it is not recommended to co-administer UDCA with MTX as it enhanced inflammation and damage to the liver.

Prevalence and risk factors of methotrexate hepatoxicity in Asian patients with psoriasis

AIM: To establish the prevalence of liver fibrosis and to evaluate the possible risk factors for fibrosis and progression in Asian with psoriasis treated with methotrexate (MTX) based on liver histology. METHODS: Patients with psoriasis treated with MTX referred to the Department of Gastroenterology, Tan Tock Seng Hospital for liver biopsy were identified and retrospectively studied. Patient case notes and electronic records were retrieved from the hospital database and relevant data collated. Histological changes of liver biopsies were staged according to Roengik score. The factors assessed were age, gender, ethnicity, cumulative dose of MTX, presence of comorbid conditions such as diabetes, hypertension, hyperlipidemia, and ethanol use. We also assessed the histological change in those with multiple liver biopsies. Statistical analysis was performed using Stata V.9.2. RESULTS: There were altogether 59 patients (median age 50 years old, range 22-81 years old, male, 88%) with 98 biopsies liver biopsies; 6 normal [median cumulative dose (MCD), 2285 mg]; 62 gradeⅠ (MCD 2885 mg), 23 grade Ⅱ (MCD 1800 mg) and 7 grade Ⅲ (MCD 1500 mg). There was no grade Ⅳ or cirrhosis. The prevalence of liver fibrosis (grade Ⅲ) was 12%. Of the factors assessed, diabetes (P=0.001) and hypertension (P=0.003) were significant for fibrosis on univariate analysis but not on multivariate analysis. Of the 26 patients who had more than one biopsy (median 2, range 2-6), 57.7% (n=15) were stable, 34.6% (n=9) had progression and 7.7% (n=2) had regression of histological grades. On univariate analysis, nonChinese ethnicity (P=0.031), diabetes (P=0.018), and hyperlipidemia (P=0.011) were predictive of progression of grades, but these were not significant on multivariate analysis. CONCLUSION: Liver fibrosis in Asian psoriatic population on MTX is comparable to the West. Cumulative dose was not associated with liver fibrosis. Metabolic syndrome is important factors.

Degradation of methotrexate by UV/peroxymonosulfate:Kinetics,effect of operational parameters and mechanism

Methotrexate(MTX)is one of the most consumed anti-cancer drugs in the pharmaceutical market around the world.The widespread occurrence of MTX in aquatic environment through hospital effluent has attracted increasing concern due to its potential to induce water pollution.In the present study,the degradation of MTX in aqueous medium was investigated by UV-activated peroxymonosulfate(PMS).A significant improvement in degradation rate by increasing UV intensity and PMS concentration while the decrease in degradation efficiency with the increase of solution p H and initial concentration of MTX was observed.The proposed UV/PMS process could achieve more than 90%MTX degradation in 30 min with a good mineralization degree(65%).A pseudofirst order kinetic model was employed and successfully predicted the degradation of MTX.The effect of other operational parameters such as the initial concentration of the targeted compound,dosage of oxidant(PMS),solution p H and UV intensity on the degradation rate were investigated.At the last,the main transform intermediates were identified using LC–MS and possible degradation pathways were proposed.The results show that UV/PMS can be used as an efficient technology to treat pharmaceuticals such as methotrexate containing water and wastewater.

Conservative management of cervical pregnancy with intramuscular administration of methotrexate and KCl injection: Case report and review of the literature

We report the case of a cervical pregnancy successfully treated with intramuscular injection of methotrexate(MTX) and intramniotic administration of potassium chloride. A 41-year-old woman was admitted to our Department with the suspicion of ectopic pregnancy. Transvaginal ultrasound revealed empty endometrialcavity, gestational sac within the cervical canal and embryonic echo measuring crown rump length 1.5 mm. Serum beta human chorionic gonadotropine(β-HCG) was measured 28590 IU/L. No cardiac activity was detected. The diagnosis of a cervical pregnancy was made. Patient was treated with intramuscular administration of methotrexate(50 mg/m2) in combination with ultrasoundguided intramniotic injection of KCl(2 meq/mL). Gradual decrease of β-HCG levels as well as ultrasound observation of collapsed gestational sac was observed. No curettage was necessitated. Patient was discharged on day 10 th and was set in follow-up on a weekly basis. β-HCG values were measured < 10 IU/L on 56 th day after MTX administration. Intramuscular administration of MTX may be effective in treatment of cervical pregnancy without additional interventional measures.

Methotrexate combined with methylprednisolone for the recovery of motor function and differential gene expression in rats with spinal cord injury

Methylprednisolone is a commonly used drug for the treatment of spinal cord injury, but high doses of methylprednisolone can increase the incidence of infectious diseases. Methotrexate has anti-inflammatory activity and immunosuppressive effects, and can reduce in- flammation after spinal cord injury. To analyze gene expression changes and the molecular mechanism of methotrexate combined with methylprednisolone in the treatment of spinal cord injury, a rat model of spinal cord contusion was prepared using the PinPointTM preci- sion cortical impactor technique. Rats were injected with methylprednisolone 30 mg/kg 30 minutes after injury, and then subcutaneously injected with 0.3 mg/kg methotrexate 1 day after injury, once a day, for 2 weeks. TreadScan gait analysis found that at 4 and 8 weeks after injury, methotrexate combined with methylprednisolone significantly improved hind limb swing time, stride time, minimum longitudinal deviation, instant speed, footprint area and regularity index. Solexa high-throughput sequencing was used to analyze differential gene ex- pression. Compared with methylprednisolone alone, differential expression of 316 genes was detected in injured spinal cord treated with methotrexate and methylprednisolone. The 275 up-regulated genes were mainly related to nerve recovery, anti-oxidative, anti-inflammatory and anti-apoptotic functions, while 41 down-regulated genes were mainly related to proinflammatory and pro-apoptotic functions. These results indicate that methotrexate combined with methylprednisolone exhibited better effects on inhibiting the activity of inflammatory cytokines and enhancing antioxidant and anti-apoptotic effects and thereby produced stronger neuroprotective effects than methotrexate alone. The 316 differentially expressed genes play an important role in the above processes.

Prediction of Response of Collagen-induced Arthritis Rats to Methotrexate： An ~1H-NMR-based Urine Metabolomic Analysis

Over one half the patients with rheumatoid arthritis （RA） are being treated with methotrexate （MTX）. Although well proven, the efficacy of MTX varies in individual patients. This study examined the metabolic biomarkers that can be used to predict the therapeutic effect of MTX by using metabolomic analysis. Rats were immunized with collagen to rapidly cause collagen-induced arthritis （CIA） and then treated with 0.1 mg/kg MTX for 4 weeks. The clinical signs and the histopathological features of CIA were observed to evaluate the therapeutic effects. Urine samples of CIA rats were collected, and analyzed by using 600 M 1H-nuclear magnetic resonance （1H-NMR） for spectral binning after the therapy. The urine spectra were divided into spectral bins, and 20 endogenous metabolites were assigned by Chenomx Suite. Multivariate analyses were performed to identify the spectral pattern of endogenous metabolites related to MTX therapy. The results showed that the clustering of the spectra of the urine samples from the responsive rats （n=20） was different from that from the non-responsive rats （n=11）. Multivariate analysis showed difference in metabolic profiles between the responsive and non-responsive rats by using partial least squares-discrimination analysis （PLS-DA） （R2=0.812, Q2=0.604）. In targeted profiling, 13 endogenous metabolites （uric acid, taurine, histidine, methionine, glycine, etc.） were selected as putative biomarkers for predicting therapeutic response to MTX. It was suggested that 1H-NMR-based metabolomic analysis can be used to predict the therapeutic effect of MTX, and several metabolites were found to be related to the therapeutic effects of MTX.

Two Cases of Primary Intraocular Lymphoma:Fine Needle Aspiration Diagnosis and Intravitreal Methotrexate Treatment

We described clinical process of two cases of intraocular lymphoma in aspects of early diagnosis by fine needle aspiration（FNA） and biopsy and treatment by intravitreal methotrexate（MTX）.Two patients were suspected to have primary intraocular lymphoma（PIOL） with geographic yellow-white infiltrates and vitreous opacity.FNA confirmed malignant intraocular lymphoma in one patient and failed in the other patient due to complication of vitreous hemorrhage.Subsequent vitreous biopsy confirmed malignant intraocular lymphoma in the other patient.Both patients were treated by intravitreal methotrexate.In case 1 the tumor had complete remission and follow-up of 12 months had not found any signs of recurrence.In case 2 the patient died of brain metastasis 22 months after the ocular biopsy.Our findings demonstrate that although cytological examination of vitrectomy specimens remains the gold standard in diagnosis of PIOL,examination of FNA and biopsy increases the reliability of early diagnosing or excluding a PIOL.Individualized intravitreal methotrexate can be used to effectively treat PIOL.More effective integrated program treating primary central nervous system lymphoma/PIOL is worthy of looking forward to.

Optimized high performance liquid chromatography–ultraviolet detection method using core-shell particles for the therapeutic monitoring of methotrexate

Methotrexate （MTX） is an antineoplastic drug, and due to its high toxicity, the therapeutic drug mon- itoring is strictly conducted in the clinical practice. The chemometric optimization and validation of a high performance liquid chromatography （HPLC） method using core-shell particles is presented for the determination of MTX in plasma during therapeutic monitoring. Experimental design and response surface methodology （RSM） were applied for the optimization of the chromatographic system and the analyte extraction step. A Poroshel1120 EC-C18 （3.0 mm × 75 mm, 2.7 μm） column was used to obtain a fast and efficient separation in a complete run time of 4 min. The optimum conditions for the chroma- tographic system resulted in a mobile phase consisting of acetic acid/sodium acetate buffer solution （85.0 mM, pH =4.00） and 11.2% of acetonitrile at a flow rate of 0.4 mL/min. Selectivity, linearity, accuracy and precision were demonstrated in a range of 0.10-6.0 μM of MTX. The application of the optimized method required only 150μL of patient plasma and a low consumption of solvent to provide rapid re- sults.

Temporal profiles of synaptic plasticity-related signals in adult mouse hippocampus with methotrexate treatment

Methotrexate, which is used to treat many malignancies and autoimmune diseases, affects brain functions including hippocampal-dependent memory function. However, the precise mechanisms underlying methotrexate-induced hippocampal dysfunction are poorly understood. To evaluate temporal changes in synaptic plasticity-related signals, the expression and activity of N-methyI-D-aspartic acid receptor 1, calcium/calmodulin-dependent protein kinase II, extracellular signal-regulated kinase 1/2, cAMP responsive element-binding protein, glutamate receptor 1, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor were examined in the hippocampi of adult C57BL/6 mice after methotrexate （40 mg/kg） intraperitoneal injection. Western blot analysis showed biphasic changes in synaptic plasticity-related signals in adult hippocampi following methotrexate treatment. N-methyI-D-aspartic acid receptor 1, calcium/calmodulin-dependent protein kinase II, and glutamate receptor 1 were acutely activated during the early phase （1 day post-injection）, while extracellular signal-regulated kinase 1/2 and cAMP responsive element-binding protein activation showed biphasic increases during the eady （1 day post-injection） and late phases （7-14 days post-injection）. Brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor expression increased significantly during the late phase （7-14 days post-injection）. Therefore, methotrexate treatment affects synaptic plasticity-related signals in the adult mouse hippocampus, suggesting that changes in synaptic plasticity-related signals may be associated with neuronal survival and plasticity-related cellular remodeling.