Application of methionyl tRNA synthetase in preparation of inflammatory disease diagnostic reagent

Abstract

The invention relates to the technical field of disease diagnosis reagents, in particular to application of methionine tRNA synthetase in preparation of an inflammatory disease diagnosis reagent. The invention provides an application of methionine tRNA (transfer ribonucleic acid) synthetase in preparation of a diagnostic reagent for inflammatory diseases. The methionyl tRNA synthetase which is a metabolite related to the inflammation and the drug treatment effect is found for the first time, whether a subject suffers from the inflammation or not and the response reaction of an inflammation patient to drug treatment can be judged by detecting the content of the metabolite, and personalized treatment of the inflammation patient is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of disease diagnostic reagents, and in particular to an application of methionyl tRNA synthetase in the preparation of diagnostic reagents for inflammatory diseases. Background Art

[0002] With the rapid progress of molecular and cellular mechanisms, the biomedical significance and application of inflammation have been completely reshaped. Inflammation is usually triggered by excessive or abnormal activation of the innate immune system. This process is now considered to be the fundamental mechanism of important diseases such as sepsis, systemic lupus erythematosus (SLE), cardiovascular disease, metabolic syndrome, cancer, sepsis, and various inflammatory joint, gastrointestinal and kidney diseases. These diseases affect hundreds of millions of people and impose a huge economic burden on the global healthcare system. In different diseases, the response of cellular and molecular factors to inflammation is both complex and diverse. Cytokines, chemokines, and small molecule mediators have become key targets for controlling a variety of inflammatory diseases. At the same time, the widespread use of biomarkers is helping to diagnose, predict and treat a variety of diseases, which is of great significance for the development of new drugs.

[0003] The inflammatory response is an important part of the immune system and is usually precisely regulated through multiple pathways. However, when inflammation gets out of control, it may lead to a variety of diseases such as acute lung injury, rheumatoid arthritis, inflammatory bowel disease, neurodegenerative diseases, septic shock, etc. Long-term inflammatory stimulation may even induce cancer, which seriously threatens human health. Therefore, accurate detection and effective control of excessive inflammatory responses are the main directions for treating these diseases. At present, there is a lack of stable, accurate, inexpensive and easy-to-use means of detecting inflammatory factors in clinical practice. This makes treatment plans based on laboratory tests for elevated inflammatory factors inaccurate in some patient groups, causing patients to suffer from long-term drug side effects without solving the fundamental problem. Therefore, it is crucial to find markers for accurate diagnosis of inflammation-related diseases.

[0004] Aminoacyl-tRNA synthetases (ARSs) act as cellular sensors for many metabolites because ARSs can bind to metabolites that are structurally similar to their corresponding amino acids. For example, MARS can bind to homocysteine ​​due to its structural similarity to methionine (Mei, X., Qi, D., Zhang, T., Zhao, Y., Jin, L., Hou, J., Wang, J., Lin, Y., Xue, Y., Zhu, P., et al. (2020). Inhibiting MARSs reduces hyperhomocysteinemia-associated neural tube and congenital heart defects. EMBO Mol Med 12, e9469.10.15252 / emmm.201809469.). Alanyl-tRNA synthetases (AARS) bind to lactate and β-alanine because they have similar structures to alanine (Mao, Y., Zhang, J., Zhou, Q., He, X., Zheng, Z., Wei, Y., Zhou, K., Lin, Y., Yu, H., Zhang, H., et al. (2024). Hypoxia induces mitochondrial protein lactylation to limit oxidative phosphorylation. Cell Res 34, 13-30.10.1038 / s41422-023-00864-6.). ARSs are increasingly recognized for their diverse non-translational functions, including roles in cellular metabolism and innate immunity (Nie, A., Sun, B., Fu, Z., and Yu, D. (2019). Roles of aminoacyl-tRNA synthetases in immune regulation and immune diseases. Cell Death Dis 10, 901.10.1038 / s41419-019-2145-5.).For example, secreted tryptophanyl-tRNA synthetases (WARS) serve as a primary defense against infection (Ahn, YH, Park, S., Choi, JJ, Park, BK, Rhee, KH, Kang, E., Ahn, S., Lee, CH, Lee, JS, Inn, KS, et al. (2016). Secreted tryptophanyl-tRNA synthetases as a primary defence system against infection. Nat Microbiol 2, 16191.10.1038 / nmicrobiol.2016.191.), while mitochondrial aspartyl-tRNA synthetases (DARS) control the mitochondrial respiratory chain and macrophage pro-resolving functions (Gu, X., Li, K., Zhang, M., Chen, Y., Zhou, J., Yao, C., Zang, Y., He, J., Wan, J., and Guo, B. (2023). Aspartyl-tRNA synthetase 2orchestrate iron-sulfurmetabolismin hematopoietic stem cells via fine-tuning alternative RNAsplicing. Cell Rep 42,113264.10.1016 / j.celrep.2023.113264.).Lysyl-tRNA synthetase (KARS1) promotes macrophage migration (Kim, SB, Kim, HR, Park, MC, Cho, S., Goughnour, PC, Han, D., Yoon, I., Kim, Y., Kang, T., Song, E., et al. (2017). Caspase-8controls thesecretion of inflammatory lysyl-tRNA synthetase in exosomes from cancer cells. J Cell Biol 216, 2201-2216.10.1083 / jcb.201605118.), and glycyl-tRNA synthetase (GARS1) secreted by macrophages exhibits anti-cancer activity (Goughnour, PC, Park, MC, Kim, SB, Jun, S., Yang, WS, Chae, S., Cho, S., Song, C., Lee, JH, Hyun, JK, et al.(2020).Extracellular vesicles derived from macrophages display glycyl-tRNAsynthetase 1and exhibit anti-cancer activity.J Extracell Vesicles10,e12029.10.1002 / jev2.12029.).

[0005] Methionyl-tRNA synthetase (MARS)-induced protein N-homocysteinylation is the main pathological mechanism of homocysteine, and MARS has been identified as a genetic risk factor for Hcy-related diseases. Methionyl-tRNA synthetase (MARS) plays a key role in initiating translation and preventing ROS-mediated damage by transferring Met to initiator tRNA (tRNAiMet), indicating that its knock-in is associated with cancer growth and drug resistance (Kim EY, Jung JY, Kim A, Kim K, Chang YS. Methionyl-tRNA synthetase overexpression is associated with poor clinical outcomes in non-small cell lung cancer. BMC Cancer. 2017 Jul 5; 17 (1): 467. doi: 10.1186 / s12885-017-3452-9. PMID: 28679377; PMCID: PMC5497355.). However, whether MARS has an inflammatory regulatory role remains unknown. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides an application of methionyl tRNA synthetase in the preparation of diagnostic reagents for inflammatory diseases. The present invention first discovered the metabolite methionyl tRNA synthetase related to inflammation and drug treatment effects. By detecting the content of the metabolite, it is possible to determine whether the subject suffers from inflammation and the response of the inflammatory patient to drug treatment, which is beneficial to the personalized treatment of inflammatory patients.

[0007] To this end, the present invention provides the following technical solutions:

[0008] In a first aspect, the present invention provides, in an optional embodiment, a use of a methionyl tRNA synthetase in the preparation of a diagnostic reagent for an inflammatory disease.

[0009] Preferably, the application comprises adding the agent to be screened to a culture system containing methionyl tRNA synthetase, and detecting the content of methionyl tRNA synthetase in the system, and if the agent to be screened can reduce the content of methionyl tRNA synthetase, it indicates that the agent to be screened is a candidate drug for treating inflammation. The method for detecting the content of methionyl tRNA synthetase in the system comprises chromatography, spectroscopy, mass spectrometry or mass spectrometry.

[0010] In a second aspect, the present invention provides a diagnostic reagent for diagnosing a disease in an optional embodiment, wherein the diagnostic reagent comprises methionyl tRNA synthetase. The disease is an inflammatory disease. In the serum of an inflammatory patient, the concentration of methionyl tRNA synthetase increases from 0.9489-2.0834 ng / mL to 2.262-3.498 ng / mL.

[0011] In a third aspect, the present invention provides, in an optional embodiment, a use of the above-mentioned diagnostic reagent in the preparation of a product for determining the response of a therapeutic agent to treat inflammation.

[0012] In a fourth aspect, the present invention provides, in an optional embodiment, a use of the above-mentioned diagnostic reagent in the preparation of a tool for diagnosing inflammation.

[0013] In a fifth aspect, the present invention provides, in an optional embodiment, a use of methionyl tRNA synthetase in constructing a computational model for predicting inflammation.

[0014] In a sixth aspect, the present invention provides, in an optional embodiment, the use of a methionyl tRNA synthetase in constructing a computational model for predicting therapeutic response to drug treatment of inflammation.

[0015] Compared with the prior art, the present invention has one of the following beneficial effects:

[0016] 1. The present invention discovered for the first time the metabolite methionyl tRNA synthetase which is related to inflammation and the effect of drug treatment. By detecting the content of the metabolite, it is possible to determine whether the subject suffers from inflammation and the response of the inflammatory patient to drug treatment, which is beneficial to the personalized treatment of inflammatory patients. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is the serum MARS concentration of the inflammatory patient and the healthy donor in Example 1 of the present invention, which is determined by enzyme-linked immunosorbent assay, wherein, Figure 1 A is the difference in plasma MARS concentration between the healthy control group and the sepsis group, which was determined by enzyme-linked immunosorbent assay; Figure 1 B is the receiver operating characteristic curve (ROC) of the samples used for MARS, and the area under the curve (AUC) is marked;

[0018] Figure 2 The results of the experiments to verify the correlation between MARS expression and inflammation in different models in Example 1 of the present invention are as follows: Figure 2 A and Figure 2 B is the expression level of MARS in the inflammatory macrophage model. Figure 2 C and Figure 2D is the expression level of MARS in the inflammatory mouse model, and the experimental group was treated with lipopolysaccharide (LPS);

[0019] Figure 3 The experimental results of Example 2 of the present invention, which overexpressed the MARS gene in different models to verify the correlation with inflammation, are as follows: Figure 3 A shows that the expression of MARS in the macrophage model with knock-in overexpression of MARS increased. Figure 3 B is the comparison of the expression of inflammatory factors in the infected macrophage model and the infected macrophage model after knocking in overexpression of MARS, where Ctrl is the control group;

[0020] Figure 4 The results of the ELISA test in Example 2 of the present invention are as follows: Figure 4 A. Figure 4 B and Figure 4 C represents the expression levels of inflammatory factors in plasma, liver tissue and primary macrophages of wild-type infected mouse model and infected mouse model after knocking in MARS, Figure 4 D is the comparison of the survival curves of the wild-type infected mouse model and the infected mouse model after knocking in MARS;

[0021] Figure 5 The results of the experiment in Example 3 of the present invention in which the MARS gene was knocked down in mice to verify the correlation with inflammation are shown in FIG. Figure 5 A. Figure 5 B and Figure 5 C represents the expression levels of inflammatory factors in plasma, liver tissue and brain tissue of the wild-type infected mouse model and the infected mouse model after knocking down MARS, Figure 5 D is the comparison of the survival curves of the wild-type infected mouse model and the infected mouse model after MARS knockdown. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0024] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0025] In order to evaluate whether metabolites can serve as markers of inflammation, the present invention studies the metabolomics of samples from subjects using drugs to treat inflammation, looks for changes in metabolites between normal and disease, and before and after disease treatment, establishes a list of important differential metabolisms, studies the biological information related to inflammation represented by them, and further screens out key metabolite biomarkers, thereby making it possible to screen and diagnose inflammation in an improved manner and at an early stage of the disease, and allowing more accurate and reliable predictions of whether patients with inflammation are likely to respond to drug therapy.

[0026] The present invention, through metabolomics sequencing and bioinformatics analysis, discovered for the first time that methionyl-tRNA synthetase showed significant differences between healthy controls and inflammation groups. The content of methionyl-tRNA synthetase (MARS) increased significantly in inflammation, and after drug treatment, the level of the metabolite decreased significantly, with no significant difference from the normal control. This suggests the potential application value of methionyl-tRNA synthetase as an inflammation biomarker.

[0027] By detecting the level or activity of methionyl tRNA synthetase and / or its related metabolic pathways (e.g., methionyl tRNA synthetase precursors, methionyl tRNA synthetase metabolites, enzymes required for methionyl tRNA synthetase production) and related kits, it is possible to determine whether the body is in an inflammatory state and the degree of inflammation. This has important application value for the diagnosis and prevention of inflammation-related diseases.

[0028] The metabolites detected include methionyl tRNA synthetase. The present invention can be detected by methods well known in the art, including but not limited to simple comparison methods such as manual comparison methods, statistical analysis methods such as t-test, Welch's T-test, Wilcoxon's rank sum test, random forest algorithm.

[0029] In the present invention, any suitable method known in the art for such metabolites can be used to analyze specific metabolites in biological samples. Quantitative analysis methods used include, but are not limited to, chromatography, spectroscopy, and mass spectrometry. A typical mass spectrometer consists of a source that ionizes molecules in a sample and a detector for detecting ionized molecules or molecular fragments.

[0030] In the present invention, the biological sample is taken from a mammal, preferably a mouse, a rat, a guinea pig, a dog, a miniature pig or a human, most preferably a human. The biological sample is preferably blood, however, any other biological sample known to those skilled in the art that allows determination according to the present invention is also suitable. The blood sample is typically whole blood, serum or plasma.

[0031] Example 1

[0032] This example provides an experiment to verify the correlation between the expression of methionyl-tRNA synthetase (hereinafter referred to as MARS) and inflammation in different models, as follows:

[0033] Table 1 is the main material list of this experiment.

[0034] Table 1 List of main materials for the experiment

[0035]

[0036] This experiment used clinical experiments, cell experiments and animal experiments to verify that the expression of methionyl-tRNA synthetase is related to inflammation:

[0037] Clinical Trials

[0038] Clinical groups: 15 samples from patients with inflammation and 15 samples from healthy donors.

[0039] Detection of MARS: Enzyme-linked immunosorbent assay was used to detect the MARS content.

[0040] Cell experiments

[0041] Cell grouping: Cells were inoculated in six-well culture plates and divided into two groups, control group and LPS intervention group. LPS treatment to construct inflammation model: LPS intervention group was treated with 100 ng / ml LPS for 4 hours, and the control group was treated with the same volume of saline. MARS detection: Western blotting and enzyme-linked immunosorbent assay were used to detect MARS content.

[0042] Animal experiments

[0043] Animal grouping: 18 SPF-grade C57BL6J male mice, 8 weeks old, about 20g, were randomly divided into two groups after 1 week of adaptive feeding, control group and LPS intervention group. 9 mice in each group. Animal model construction and drug treatment: The experimental mice were fasted for 12 hours before modeling, but not water. The control group was injected with an equal volume of saline, and the LPS group received 7 intraperitoneal injections of LPS (50μg / kg, 1h apart each time). Liver collection: 6 hours after the completion of the construction of the two groups of models, the liver tissue was taken and directly frozen in liquid nitrogen and then stored at -80℃ for later use. MARS detection: Protein immunoblotting and enzyme-linked immunosorbent assay were used to detect the MARS content.

[0044] Data analysis: The data were analyzed by one-way ANOVA using Prism9.0 software, and the significant results are marked on the graphs.

[0045] Experimental results: Passed Figure 1It can be seen that MARS increased significantly in the inflammatory group in the clinical samples. There were 15 patients with inflammation registered. The average normal serum MARS concentration from 15 healthy controls was 1.516 ng / ml, and the average serum MARS concentration of the inflammatory patients increased significantly to 2.262 ng / ml (see Figure 1 A and Table 2).

[0046] Table 2 MARS concentrations in serum of inflammatory patients and healthy donors

[0047] Healthy donors n = 15 Patients with inflammation n = 15 P-value MARS (ng / ml) 1.516±0.5674 2.262±1.236 0.0424

[0048] The area under the ROC curve was then used to detect the discriminative power of MARS concentration in the above group of inflammatory patients (see Figure 1 B and Table 3).

[0049] Table 3 Sensitivity and specificity of MARS for the optimal diagnostic cutoff value of inflammation

[0050] Critical Level Sensitivity (%) Specificity (%) MARS (ng / ml) 1.752 60 80

[0051] See also Figure 2 WB and ELISA were used to detect the relative MARS mRNA expression levels in IBMDB cells and mice in the LPS-treated inflammatory model. The MARS expression level was significantly increased compared with the control group.

[0052] Example 2

[0053] This example provides an experiment of knocking in the MARS gene in different models to verify the correlation with inflammation, as follows

[0054] Table 4 is the main material list of this experiment.

[0055] Table 4 List of main materials for the experiment

[0056]

[0057] This experiment knocked in the MARS gene in different models through cell experiments and animal experiments to verify its correlation with inflammation:

[0058] Cell experiments

[0059] Cell grouping: Bone marrow-derived macrophages IBMDB were inoculated in six-well culture plates and divided into two groups, LPS intervention group (Ctrl+LPS group) and LPS intervention MARS knock-in group (MARS+LPS group). Preparation of IBMDM with MARS knock-in: 293T cells were plated on 6-well plates and transfected when the cell confluence reached 80-90%. The transfection system was 150μl A solution: 4μl lipofectamine3000+146μlOpti-MEM, 150μl B solution: (pCDH-Myc-MARS1-Puro: gag: vsvg = 4:3:1, i.e. 1.6ug: 1.2ug: 0.4ug) + 5.69μl P3000+Opti-MEM, mixed. Add B solution to A solution and mix well, let stand at room temperature for 10-15min, and add it dropwise to the 293T culture well. After 24h of 293T cell transfection, change to normal culture medium. 48 hours after transfection, collect the first wave of virus (use a 5ml syringe to absorb the cell culture supernatant, and filter it into a 15ml centrifuge tube with a 0.45μm filter membrane). 72 hours after transfection, collect the second wave of virus. IB cells are subcultured and inoculated into six-well plates at a ratio of 1:5-10 to prepare for infection the next day. The infection system is 1.5ml virus liquid + 3ml IB culture medium (the ratio is adjusted according to the actual situation. A high ratio of virus liquid means higher transfection efficiency, but the cell tolerance should be considered) + Polybrene (final concentration 8μg / ml), mix well. Then remove the IB culture medium in the six-well plate and add the prepared infection system to the culture well. After 24 hours, change to normal culture medium. 48 hours after virus infection, add Amp to screen out cells with positive infection. After that, continue to change the culture medium containing antibiotics every day. After 7 days of screening, digest and subculture, and use it for identification and experiments after amplification and culture. Inflammatory model was constructed by LPS treatment: 100 ng / ml LPS was added to both groups for 4 hours. Detection of inflammatory factors: Enzyme-linked immunosorbent assay was used to detect the levels of IL-1β, IL-6, and TNFα in the two groups.

[0060] Animal experiments

[0061] Methionyl tRNA synthetase knock-in mouse model: purchased from Cyagen. Animal grouping for metabolite detection: 18 SPF female 5-6 week-old (14-16g) mice were randomly divided into a control group (WT group) and an LPS intervention group (WT+LPS group); 18 methionyl tRNA synthetase knock-in female 5-6 week-old (14-16g) mice were randomly divided into a MARS knock-in group (MARS Ki group) and a MARS knock-in LPS intervention group (MARS Ki+LPS group). LPS treatment to construct a mouse inflammation model: The experimental mice were fasted for 12 hours before modeling, but not water. LPS (25mg / kg body weight) was added to the WT+LPS group and the MARS Ki+LPS group, and an equal amount of normal saline was added to the WT group and the MARS Ki group. Collection of plasma, BMDM and liver: 6 hours after LPS treatment, plasma, BMDM and liver were directly frozen in liquid nitrogen and then stored at -80℃ for later use. Detection of inflammatory factors and MARS: Enzyme-linked immunosorbent assay and real-time fluorescent quantitative polymerase chain reaction were used to detect the content of inflammatory factors and MARS. Animal grouping was used to construct the survival curve: 10 SPF female 5-6 week-old (14-16g) mice were used as the LPS-treated control group (WT+LPS group); 10 female 5-6 week-old (14-16g) mice with methionyl tRNA synthetase knock-in were used as the MARS knock-in LPS intervention group (MARS Ki+LPS group). LPS treatment was used to construct a lethal mouse inflammation model: experimental mice were fasted for 12 hours before modeling, but water was not allowed. LPS (35mg / kg body weight) was added to the WT+LPS group and the MARS Ki+LPS group, and the survival curve was prepared after 48 hours of observation.

[0062] Data analysis: The data were analyzed by one-way ANOVA using Prism9.0 software, and the significant results are marked on the graphs.

[0063] Experimental results: Passed Figure 3 It can be seen that WB was used to prove that MARS was successfully knocked in and overexpressed in IBMDM. ELISA experiments showed that the levels of IL-1β, IL-6, and TNFα in the Mars overexpression group + LPS were significantly increased compared with the control group + LPS group. Figure 4 Enzyme-linked immunosorbent assays demonstrated that the levels of IL-1β, IL-6, and TNFα in the plasma, bone marrow-derived macrophages, and liver of mice were significantly increased in the Mars knock-in + LPS group compared with other groups, and the survival rate was decreased.

[0064] Example 3

[0065] This example provides an experiment to knock down the MARS gene in mice to verify its correlation with inflammation, as follows:

[0066] Table 5 is the main material list of this experiment.

[0067] Table 5 List of main materials for the experiment

[0068] Reagent name source Part Number Mice with knockdown of methionyl-tRNA synthetase Cyagen / LPS SIGMA L3129 Actin Aibixin abs137975

[0069] This experiment used animal experiments to verify the knockdown of the MARS gene in mice and verify its correlation with inflammation:

[0070] Animal experiments

[0071] Methionyl tRNA synthetase knockdown mouse model: purchased from Cyagen Animal grouping for metabolite detection: 9 SPF female 5-6 week old (14-16g) mice were used as the LPS treatment control group (WT+LPS group); 9 methionyl tRNA synthetase knockdown female 5-6 week old (14-16g) mice were used as the MARS knockdown LPS intervention group (MARS + / - +LPS group). LPS treatment was used to construct the mouse inflammation model: the experimental mice were fasted for 12 hours before modeling, but water was not allowed. + / - +LPS group was added with LPS (25 mg / kg body weight). Collection of plasma, liver and brain tissues: 6 hours after LPS treatment, plasma, liver and brain tissues were taken and frozen directly in liquid nitrogen and then stored at -80℃ for later use. Detection of inflammatory factors and MARS: Enzyme-linked immunosorbent assay and real-time fluorescent quantitative polymerase chain reaction were used to detect the content of inflammatory factors and MARS. Animal grouping was used for the construction of survival curve: 10 SPF female 5-6 week-old (14-16g) mice were used as the LPS-treated control group (WT+LPS group); 10 female 5-6 week-old (14-16g) mice with methionyl tRNA synthetase knockdown were used as the LPS intervention group with MARS knockdown (MARS + / - +LPS group). LPS treatment was used to construct a lethal mouse inflammation model: the experimental mice were fasted for 12 hours before modeling, but not water. + / - The +LPS group was given LPS (35 mg / kg body weight), observed for 48 hours, and a survival curve was drawn.

[0072] Data analysis: The data were analyzed by one-way ANOVA using Prism9.0 software, and the significant results are marked on the graphs.

[0073] Experimental results:

[0074] Figure 5Enzyme-linked immunosorbent assays demonstrated that in the plasma, brain tissue, and liver of mice, the levels of IL-1β, IL-6, and TNFα in the MARS knockdown + LPS group were significantly reduced compared with the wild-type + LPS group, and the survival rate was improved.

[0075] Although the principles of the present invention are described in detail above in conjunction with the preferred embodiments of the present invention, those skilled in the art should understand that the above embodiments are merely explanations of the exemplary implementations of the present invention, and are not intended to limit the scope of the present invention. The details in the embodiments do not constitute limitations on the scope of the present invention, and any obvious changes such as equivalent transformations, simple replacements, etc. based on the technical solution of the present invention, without departing from the spirit and scope of the present invention, fall within the protection scope of the present invention.

Claims

1. Use of a methionyl-tRNA synthetase in the preparation of diagnostic reagents for inflammatory diseases.

2. The use according to claim 1, characterized in that: The application includes adding the agent to be screened into a culture system containing methionyl tRNA synthetase, and detecting the content of methionyl tRNA synthetase in the system. If the agent to be screened can reduce the content of methionyl tRNA synthetase, it indicates that the agent to be screened is a candidate drug for treating inflammation.

3. The use according to claim 2, characterized in that: Methods for detecting the content of methionyl tRNA synthetase in the system include chromatography, spectroscopy, mass spectrometry or mass spectrometry.

4. A diagnostic reagent for diagnosing a disease, characterized in that The diagnostic reagent includes methionyl tRNA synthetase.

5. The diagnostic reagent according to claim 4, characterized in that The disease is an inflammatory disease.

6. The diagnostic reagent according to claim 4, characterized in that In the serum of patients with inflammation, the concentration of methionyl tRNA synthetase increased from 0.9489-2.0834 ng / mL to 2.262-3.498 ng / mL.

7. Use of the diagnostic reagent according to any one of claims 4 to 6 in the preparation of a product for determining the response of a therapeutic agent to treat inflammation.

8. Use of the diagnostic reagent according to any one of claims 4 to 6 in the preparation of a tool for diagnosing inflammation.

9. Application of a methionyl-tRNA synthetase in constructing a computational model for predicting inflammation.

10. Application of a methionyl tRNA synthetase in constructing a computational model for predicting therapeutic response to drug treatment of inflammation.

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