Ademetionine 1,4-Butanedisulfonate

Methionine adenosyltransferase 2A (MAT2A) is an essential enzyme in the methionine cycle that generates S-adenosylmethionine (SAM) by reacting with methionine and ATP. SAM acts as a methyl donors for histone and DNA methylation, which plays key roles in zygotic genome activation (ZGA). However, the effects of MAT2A on porcine ZGA remain unclear. To investigate the function of MAT2A and its underlying mechanism in porcine ZGA, MAT2A was knocked down by double-stranded RNA injection at the 1-cell stage. MAT2A is highly expressed at every stage of porcine embryo development. The percentages of four-cell-stage embryos and blastocysts were lower in the MAT2A-knockdown (KD) group than in the control group. Notably, depletion of MAT2A decreased the levels of H3K4me2, H3K9me2/3, and H3K27me3 at the four-cell stage, whereas MAT2A KD reduced the transcriptional activity of ZGA genes. MAT2A KD decreased embryonic ectoderm development (EED) and enhancer of zeste homolog 2 (EZH2) expression. Exogenous SAM supplementation rescued histone methylation levels and developmental arrest induced by MAT2A KD. Additionally, MAT2A KD significantly increased DNA damage and apoptosis. In conclusion, MAT2A is involved in regulating transcriptional activity and is essential for regulating histone methylation during porcine ZGA.

Drug-induced liver injury (DILI) is one of the most common adverse reactions of anti-tuberculosis treatment. To improve the diagnosis and management of anti-tuberculosis drug-induced liver injury (ATB-DILI) for clinicians and tuberculosis control workers, the Chinese Medical Association Tuberculosis Branch has developed guidelines for the diagnosis and treatment of ATB-DILI. These guidelines summarized recent research progress in relevant fields and provide detailed explanations, recommendations, and quality assessments related to ATB-DILI, covering aspects such as definition, risk factors, mechanisms, pathological manifestations, clinical classification, diagnosis, and management. The key recommendations are as follows.Recommendation 1: Risk factors: NAT2 slow acetylation genotype, GSTM1 gene variation, advanced age, hepatitis virus infection or concurrent acute/chronic liver disease, HIV infection, malnutrition, and alcohol (ethanol) intake are risk factors for ATB-DILI (2, B).Recommendation 2: R-value calculation: Calculate the R-value for suspected ATB-DILI patients at different time points during the course of the disease. ALT and ALP values should be obtained on the same day, with a maximum interval of no more than 48 hours. This helps to accurately determine the clinical type and prognosis of DILI (2, C).Recommendation 3: Comprehensive medical history collection: Collect information on past medication history, clinical features, dynamic changes in liver biochemical markers, drug rechallenge reactions, comorbidities, and underlying liver diseases (4, B).Recommendation 4: Liver biochemical tests: Include at least ALT, AST, ALP, GGT, TBil, DBil, and albumin. If necessary, measure prothrombin time or international normalized ratio (INR) (3, B).Recommendation 5: Abdominal imaging: Routine abdominal imaging should be performed for suspected ATB-DILI patients (3, B).Recommendation 6: Liver histopathological examination: Histology of liver biopsies aids in the diagnosis and differential diagnosis of DILI (4, B).Recommendation 7: Biochemical diagnostic criteria for acute ATB-DILI: Liver biochemical tests should meet one of the following criteria: ALT≥3×ULN and/or TBil≥2×ULN; simultaneous elevation of AST, ALP, and TBil, with at least one parameter≥2×ULN (4, C).Recommendation 8: Diagnostic criteria for ATB-DILI: Diagnosis requires:(1) A history of exposure to anti-tuberculosis drugs that can cause liver injury;(2)Rapid normalization of abnormal liver biochemical markers after drug discontinuation: For patients with hepatocellular injury, a decrease in the peak serum ALT level of at least 50% within 8 days is highly suggestive, while a decrease of at least 50% within 30 days is considered important. For patients with cholestatic injury, a serum ALP or TBil peak level that decreases by at least 50% within 180 days is also considered important;(3) Exclusion of other causes of liver injury;(4) Positive rechallenge reaction. Meeting three of the above criteria confirms ATB-DILI, whereas meeting (1) and (2) criteria indicates a suspected case. In practice, the vast majority of ATB-DILI are suspected cases (3, B).Recommendation 9: Avoid re-exposure: Minimize re-exposure to the same suspected drug, especially if the initial exposure caused severe liver injury (4, B).Recommendation 10: Causality assessment: Use the RUCAM scale as the primary method for assessing causality. In cases involving multiple hepatotoxic drugs, concurrent liver disease, or new drug clinical trials, combine expert opinions for reliable assessment (3, B).Recommendation 11: Baseline testing: All patients are recommended to undergo baseline liver biochemistry, HBsAg (if HBsAg is positive, further HBV DNA testing), anti-HCV testing, and abdominal imaging before starting anti-TB treatment (3, B).Recommendation 12: Monitoring frequency: Patients without high-risk factors should have monthly liver biochemical monitoring (4, C);high-risk patients or those using hepatotoxic drugs should be monitored every 2 weeks during the first 2 months of anti-tuberculosis treatment, then monthly (2, B).Recommendation 13: Avoid concurrent hepatotoxic drugs: Evaluate the benefit-risk ratio of using other hepatotoxic drugs or traditional Chinese medicine (4, C).Recommendation 14: Antiviral treatment: In ATB-DILI patients with viral hepatitis, consider prompt antiviral therapy if indicated (3, B).Recommendation 15: NAT2 genotyping: Guide isoniazid dosing based on NAT2 gene polymorphism (4, C).Recommendation 16: Application of preventive hepatoprotective drugs: People with high risk factors for liver damage may consider it (4, C); however, routine use in the general population is not recommended (2, B).Recommendation 17: Immediate discontinuation: In the case of ATB-DILI, suspected drugs should be discontinued immediately (4, A).Recommendation 18: N-acetylcysteine (NAC): Early intravenous administration of NAC is beneficial for acute liver failure and subacute liver failure induced by drugs in adults (4, D).Recommendation 19: Glucocorticoids: Use with caution;not recommended as routine treatment for ATB-DILI(4, C);may be considered for immune-mediated DILI with hypersensitivity and autoimmune features (3, B).Recommendation 20: For acute hepatocellular injury or mixed DILI with significantly elevated ALT/AST, bicyclol and/or magnesium isoglycyrrhizinate are recommended (2, B).Recommendation 21: For mild to moderate hepatocellular injury type DILI with elevated ALT/AST, reasonable choices include ammonium glycyrrhizinate, compound glycyrrhizin, and other glycyrrhizic acid derivatives, glutathione, silymarin, polyenylphosphatidylcholine, and other drugs (4, C); For cholestatic DILI with elevated ALP/GGT/TBil, ursodeoxycholic acid or S-adenosylmethionine may be selected (4, C); the combined use of two or more drugs that mainly reduce ALT is not recommended (4, B).Recommendation 22: Treatment of severe patients: For severe patients such as those with drug-induced liver failure, liver transplantation is recommended (2, B); artificial liver (high-volume plasma exchange, dual plasma molecular adsorption system, etc.) may be a beneficial option (4, C); ornithine aspartate may help reduce blood ammonia levels in patients with severe disease or liver failure (4, C).Recommendation 23: Rational drug use during the recovery period: During or after liver function recovery, clinicians should comprehensively assess the patient's liver injury severity, presence of liver injury-related risk factors, and tuberculosis severity. Based on this assessment, anti-tuberculosis drugs should be selected rationally (4, C). These recommendations provide clinical evidence and decision-making guidance for the standardized diagnosis and treatment of ATB-DILI.