We reported one case of MTX-induced aplastic anemia and reviewed related literature to investigate the mechanism of action of MTX, and summarize the clinical feature, diagnostic criteria, risk factor, and interventions. These were hoped to arouse the attention of clinicians and clinical pharmacists, in order to effectively prevent, diagnose, and treat MTX-induced aplastic anemia.
Objective To investigate the role and mechanisms of trimetazidine (TMZ) in intensive care unit-acquired weakness (ICU-AW). Methods Seventy wild-type male C57BL/6 mice were selected and the ICU-AW mouse model was constructed by intraperitoneal injection of different concentrations of lipopolysaccharide (LPS). The body weights, grip strengths, and 96-hour survival rates of each group were observed, and the optimal concentration of LPS and time of sampling were screened out, the mRNA and protein expression of the gastrocnemius muscle atrophic proteins Atrogin-1 and muscle-specific RING finger protein 1 (MuRF1) were further detected to verify the success of modelling, and LPS (12 mg/kg) was used as the subsequent modelling concentration according to the preliminary results. After successful modelling, another 70 mice were randomly divided into normal control group (Normal group), LPS solvent (Vehicle) group, LPS group, LPS+TMZ solvent group, LPS+TMZ group, LPS+TMZ+AC-YVAD-CMK (AC) solvent group, and LPS+TMZ+AC group, with 10 mice in each group. The Normal group did not have any intervention; the Vehicle group was injected intraperitoneally with an equal volume of saline with LPS; the remaining groups were injected intraperitoneally with LPS (12 mg/kg); after the completion of the LPS injection, the LPS+TMZ group, the LPS+TMZ+AC solvent group, and the LPS+TMZ+AC group were given TMZ (5 mg/kg) by gastric gavage once a day for 4 days. The LPS+TMZ solvent group was given TMZ equivalent saline gavage once a day for 4 days. The LPS+TMZ+AC group was injected intraperitoneally with the cysteinyl aspartate specific proteinase 1 (Caspase-1) inhibitor AC-YVAD-CMK (AC, 6.5 mg/kg) 1 h before LPS injection, and the LPS+TMZ+AC solvent group was injected with an equal amount of AC solvent phosphate buffer. At the end of TMZ treatment, body weight, grip strength, 96-hour survival rate, mRNA and protein expression of MuRF1, Atrogin-1, Caspase-1, and gasdermin D (GSDMD) in gastrocnemius muscle, as well as serum IL-1β and IL-18 concentrations in mice were detected in each group, and the gastrocnemius muscle was stained with HE to observe histopathological changes. Results Compared with the Normal group, mice in the LPS (12 mg/kg) and LPS (14 mg/kg) groups showed significant decreases in body weight and grasping strength and the weakening was most obvious at 3 - 5 d (P<0.05), but the survival rate of the LPS (12 mg/kg) group was higher than that of the LPS (14 mg/kg) group (P<0.05), the HE staining of gastrocnemius muscle showed that the mice in the LPS (12 mg/kg) group was significantly atrophied compared with that of the Normal group, and the gene and protein expression of MuRF1 and Atrogin-1 were significantly elevated (P<0.05), and the mice injected with LPS (12 mg/kg) for 4 days (96 h) were finally selected as the conditions for subsequent experimental modelling and sampling.The mRNA and protein expression of Caspase-1 and GSDMD in skeletal muscle was significantly higher in the LPS group compared with the Normal and Vehicle groups (P<0.01), and the concentrations of serum IL-1β and IL-18 were significantly higher(P<0.01). Mice in the TMZ group showed significant improvement in body weight, grip strength, survival rate, and degree of muscle atrophy compared with the LPS and TMZ solvent groups (P<0.05); gene and protein levels of MuRF1, Atrogin-1, Caspase-1, and GSDMD in the gastrocnemius muscle were significantly reduced (P<0.05); and levels of serum IL-1β and IL-18 were significantly reduced (P<0.05) ); the mice in the LPS+TMZ+AC group had significantly improved body weight, grip strength, survival rate, and muscle atrophy compared with the LPS+TMZ group and the LPS+TMZ+AC solvent group (P<0.05), and the gene and protein contents of MuRF1, Atrogin-1, Caspase-1, and GSDMD in the gastrocnemius muscle were reduced (P<0.05), and the serum IL-1β and IL -18 concentrations were reduced (P<0.05). Conclusion TMZ is able to exert a skeletal muscle protective effect by inhibiting Caspase-1/GSDMD-mediated pyroptosis, which is an important reference for the prevention and treatment of ICU-AW.