Application of adenosine deaminase or modifier of adenosine deaminase in preparation of medicine for treating diabetic nephropathy

Abstract

The invention discloses application of adenosine deaminase or a modifier thereof in preparation of a medicine for treating diabetic nephropathy. After intraperitoneal injection treatment of polyethylene glycol modified escherichia coli expressed mouse adenosine deaminase is carried out on a mouse with diabetic nephropathy, the damage degree of the kidney of the mouse is obviously weakened. According to the invention, the adenosine deaminase or the modifier thereof has an obvious treatment effect on the type 2 diabetic nephropathy for the first time, and the adenosine deaminase and the modifier thereof have potential application prospects in preparation of the medicines for treating the type 2 diabetic nephropathy.

Description

Technical Field

[0001] The invention belongs to the technical field of biomedicine and relates to the application of adenosine deaminase or its modified product in the preparation of a drug for treating diabetic nephropathy. Background Art

[0002] Diabetes is a common metabolic endocrine disease, the main characteristics of which are abnormal metabolism of biological macromolecules and symptoms of hyperglycemia caused by insulin deficiency or insulin resistance. Long-term hyperglycemia can lead to serious complications, including cardiovascular complications, neuropathy, renal failure and cancer.

[0003] Diabetic Kidney Disease (DKD) is one of the most common and serious complications of diabetes and the most common cause of chronic kidney disease. The onset of diabetic nephropathy is insidious. In the early stages of the disease, patients have trace amounts of albumin in their urine, and the symptoms are mild and difficult to detect. In the later stages of the disease, albumin in the urine increases, glomerulosclerosis and renal fibrosis occur, and eventually lead to kidney failure and cardiovascular disease. Currently, there is still a lack of effective treatments for diabetic nephropathy, and the development of new drugs for the treatment of diabetic nephropathy is urgent.

[0004] Adenosine deaminase (ADA) is a purine decomposition enzyme that converts adenosine to inosine, thereby helping to reduce the level of adenosine present in tissues and cells. Adenosine deaminase deficiency is a rare inherited purine metabolism disease characterized by immunodeficiency, developmental impairment, and metabolic abnormalities. ADA deficiency leads to the accumulation of toxic metabolites, which causes cell-mediated humoral immune deficiency and leads to severe combined immunodeficiency (SCID). In 1990, the US FDA approved ADAGEN (pegademase bovine) for the treatment of infants or children of any age with severe combined immunodeficiency. The drug is a drug that is extracted from bovine adenosine deaminase and modified with polyethylene glycol to effectively treat severe combined immunodeficiency. Summary of the invention

[0005] The object of the present invention is to provide the use of adenosine deaminase or its modified product in the preparation of a drug for treating diabetic nephropathy.

[0006] The diabetic nephropathy described in the present invention is type 2 diabetic nephropathy.

[0007] The adenosine deaminase described in the present invention can be adenosine deaminase obtained in any manner, including but not limited to natural adenosine deaminase extracted from biological tissues, recombinant adenosine deaminase from human, animal and microbial sources, and chemically synthesized adenosine deaminase.

[0008] The adenosine deaminase modifier described in the present invention is an adenosine deaminase modifier obtained by chemically modifying adenosine deaminase to increase its stability and extend its half-life; including but not limited to polyethylene glycol modification, dextran modification, heparin modification, or adenosine deaminase fused and expressed with a protein or polypeptide capable of targeting the neonatal Fc receptor or albumin.

[0009] Specifically, in the specific embodiments of the present invention, the adenosine deaminase modifier used is polyethylene glycol-modified Escherichia coli-expressed murine adenosine deaminase.

[0010] The therapeutic drug for diabetic nephropathy described in the present invention is a composition containing one or more of adenosine deaminase or its modifiers, and also contains a pharmaceutically acceptable carrier or excipient, and is formulated into a pharmaceutically acceptable dosage form.

[0011] The dosage of adenosine deaminase or its modifier in the therapeutic drug for diabetic nephropathy described in the present invention can be appropriately adjusted according to the condition. As an alternative, the intraperitoneal injection concentration of polyethylene glycol-modified Escherichia coli-expressed murine adenosine deaminase is 2 U / g (1 U represents the amount of adenosine deaminase that decomposes 1 μmol of adenosine per minute under specific conditions, and U / g represents the enzyme activity of ADA injected per gram of the patient's body weight).

[0012] The present invention first discloses the application of adenosine deaminase and its modifiers, which are widely sourced and have excellent biocompatibility, in the preparation of therapeutic drugs for diabetic nephropathy, and they can delay or even repair diabetic renal failure. Description of the Drawings

[0013] Figure 1 It is a graph showing the influence of PEG-ADA on the contents of serum creatinine (CRE) (A) and blood urea nitrogen (BUN) (B) in db / db diabetic nephropathy mice.

[0014] Figure 2 It is a graph showing the influence of PEG-ADA on the contents of serum total cholesterol (TCHO) (A), triglyceride (TRIG) (B), high-density lipoprotein cholesterol (HDL-C) (C), and low-density lipoprotein cholesterol (LDL-C) (D) in db / db diabetic nephropathy mice.

[0015] Figure 3 It is a graph showing the influence of PEG-ADA on the kidney index (Kidney / body) of db / db diabetic nephropathy mice.

[0016] Figure 4 It is a graph showing the influence of PEG-ADA on diabetic nephropathy in db / db mice. Specific Embodiments

[0017] The present invention will be further described in detail below in conjunction with specific embodiments and the accompanying drawings. Unless otherwise specified, the methods used in the following embodiments are all conventional methods commonly used in the art.

[0018] Unless otherwise specified, all raw materials used in the following embodiments are commercially available products.

[0019] The preparation of mouse adenosine deaminase expressed by polyethylene glycol-modified Escherichia coli (PEG-ADA) involved in the following embodiments refers to Chinese Patent ZL2021113276310.

[0020] Example 1 Effect of Mouse Adenosine Deaminase Expressed by Polyethylene Glycol-Modified Escherichia Coli on Renal Function of Diabetic Mice

[0021] (1) Experimental grouping

[0022] SPF-grade male db / db mice (type 2 diabetic nephropathy model), 8 weeks old, were raised under standard experimental conditions: 12-hour light - 12-hour dark cycle, with free access to water and food. They were randomly divided into two groups, the db / db group and the db / db-ADA group. The db / db group was treated with the corresponding drug medium (PBS); the db / db-ADA group was intraperitoneally injected with PEG-ADA (2 U / g).

[0023] (3) Determination of serum biochemical indexes

[0024] After the treatment was completed, the mice were sacrificed, and serum was taken to measure the contents of creatinine, urea nitrogen, total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol.

[0025] (4) Determination of kidney index

[0026] The kidneys of the mice were weighed, and the kidney index = kidney weight / body weight (mg / g)

[0027] (5) Histopathological observation of the kidney

[0028] After the control group was treated with PBS and the adenosine deaminase treatment group was intraperitoneally injected with PEG-ADA for 1 month, the kidneys were taken for histopathological observation. The specific method was as follows: After the treatment was completed, the mice were sacrificed, the kidneys were fixed in 4% paraformaldehyde, paraffin-embedded, sectioned, and observed under a microscope after PAS and Masson staining.

[0029] (6) Experimental results

[0030] Combined with Figure 1 The experimental results showed that after diabetic mice were treated with PEG-ADA, the contents of serum creatinine and urea nitrogen in the mice decreased significantly; Combined with Figure 2The experimental results showed that after the diabetic mice were treated with PEG-ADA, the contents of total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol in the mouse serum decreased significantly; combined with Figure 3 The experimental results showed that after the diabetic mice were treated with adenosine deaminase, the kidney index of the mice decreased significantly; combined with Figure 4 The experimental results showed that there were no obvious pathological changes in the renal tissues of the mice in the normal control group; the pathological manifestations of the kidneys of the diabetic nephropathy mice were glomerular hypertrophy, widened mesangial area including increased mesangial cells and mesangial matrix, and significantly increased collagen fibers; after treatment with adenosine deaminase, the above pathological changes were significantly alleviated. The above results indicate that PEG-ADA can effectively treat diabetic nephropathy in db / db mice.

Claims

1. Use of adenosine deaminase or its modified form in the preparation of a therapeutic drug for diabetic nephropathy.

2. The application according to claim 1, characterized in that, The diabetic nephropathy is type 2 diabetic nephropathy.

3. The application according to claim 1, characterized in that, The adenosine deaminase is natural adenosine deaminase extracted from biological tissues, recombinant adenosine deaminase from human, animal and microbial sources, and chemically synthesized adenosine deaminase.

4. The application according to claim 1, characterized in that, The adenosine deaminase modified form is adenosine deaminase modified by polyethylene glycol, dextran, heparin, or fused and expressed with a protein or polypeptide capable of targeting the neonatal Fc receptor or albumin.

5. The application according to claim 1, wherein The adenosine deaminase modified form is polyethylene glycol modified Escherichia coli-expressed murine adenosine deaminase.

6. The application according to claim 1, characterized in that, The therapeutic drug for diabetic nephropathy is a composition containing one or more of adenosine deaminase or its modified form.

7. The application according to claim 1, characterized in that, The therapeutic drug for diabetic nephropathy further contains a pharmaceutically acceptable carrier or excipient.

8. The application according to claim 1, characterized in that The intraperitoneal injection concentration of polyethylene glycol modified Escherichia coli-expressed murine adenosine deaminase is 2 U / g.

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