Antibacterial peptide HsTx-AMP1 and application thereof in improvement of ulcerative colitis

Abstract

The invention discloses an antibacterial peptide HsTx-AMP1 and an application of the antibacterial peptide HsTx-AMP1 in improvement of ulcerative colitis. The amino acid sequence of the antibacterial peptide HsTx-AMP1 is LWSFLFKAATKLLPSIFGGGKKSSSRR, and the amino acid sequence of the antibacterial peptide HsTx-AMP1 is shown in the specification. The application refers to the application in preparation of medicines for treating ulcerative colitis or medicines for relieving intestinal mucosa inflammation. The antibacterial peptide HsTx-AMP1 provided by the invention is derived from tropical rainforest scorpions, and has the generality of the scorpion-derived antibacterial peptide: broad spectrum of action, strong activity, difficult generation of drug resistance and the like. Experiments prove that the traditional Chinese medicine composition has excellent ulcerative colitis relieving activity, can reduce the DAI score of a mouse with DSS colitis, and has a good recovery effect on the colon length of the mouse with DSS colitis. The antibacterial peptide HsTx-AMP1 provided by the invention provides a new drug lead molecule for research and development of ulcerative colitis drugs.

Description

Technical Field

[0001] The present invention belongs to the field of biomedicine technology, and specifically relates to an antimicrobial peptide HsTx-AMP1 and an application thereof in improving ulcerative colitis. Background Art

[0002] Ulcerative colitis (UC) is a chronic nonspecific inflammatory disease of the colorectum with unknown etiology. The lesions mainly accumulate in the colorectal mucosa and submucosa. At present, with the development of world industrialization, changes in the natural environment and changes in people's lifestyles, the global incidence of UC has continued to rise in the past 20 years. By 2025, IBD is expected to affect 30 million people worldwide. The main clinical features of UC are diarrhea, abdominal pain, mucus and blood in the stool, and tenesmus. Some patients also have extraintestinal manifestations such as arthritis, iritis, and gangrene pyoderma. It recurs repeatedly and cannot be cured. The cost of treatment is expensive, often leading to poverty, disability, and even death. It consumes huge health resources and brings a heavy burden to patients, families, and even society. It has become a global problem. The exact pathogenesis of UC is still unclear, but current studies believe that genetic susceptibility, intestinal mucosal barrier defects, immune response disorders, intestinal flora disorders, and the external environment are the main causes of UC. At present, a variety of drugs are used clinically to treat UC, such as 5-aminosalicylic acid preparations, glucocorticoids, immunosuppressants, tumor necrosis factor antagonists, integrin receptor blockers, interleukin antagonists and JAK inhibitors. Current drug treatments are difficult to completely treat UC and have adverse reactions, and drug treatments are very expensive. Therefore, it is urgent to further develop new treatments to induce remission of ulcerative colitis.

[0003] Antimicrobial peptides are short amino acids with innate immune defense functions. They have the advantages of broad-spectrum action, strong activity, and low resistance to drug resistance. They can regulate the composition of the intestinal microbiota, thereby changing the relationship between the intestinal microbiota and the intestinal barrier in UC patients, and have great potential in the treatment of the disease. Scorpion venom, as one of the most representative animal venoms, contains a variety of bioactive peptides. In recent years, it has also emerged in the field of global drug research and development due to its therapeutic properties, becoming an important candidate for drug development and design. However, antimicrobial peptides derived from scorpions are still rarely reported in the study of ulcerative colitis.

[0004] Tropical rainforest scorpions are widely distributed in tropical rainforests in Asia. In order to survive, they use the toxins they produce for defense or attack to find food. Their venom is rich in a variety of bioactive peptides. The present invention aims to provide an antimicrobial peptide HsTx-AMP1 derived from tropical rainforest scorpions that significantly promotes the relief of intestinal mucosal inflammation in ulcerative colitis. Summary of the invention

[0005] The first object of the present invention is to provide an antimicrobial peptide HsTx-AMP1, and the second object of the present invention is to provide an application of the antimicrobial peptide HsTx-AMP1.

[0006] The first object of the present invention is achieved in that the antimicrobial peptide HsTx-AMP1 has an amino acid sequence as shown in SEQ ID NO: 1: LWSFLFKAATKLLPSIFGGGKKSSSRR, and a structural formula as shown in Figure 1 shown.

[0007] The second object of the present invention is achieved in that the antimicrobial peptide HsTx-AMP1 is used in the preparation of a drug for treating ulcerative colitis or a drug for alleviating intestinal mucosal inflammation.

[0008] The beneficial effects of the present invention are as follows: the antimicrobial peptide HsTx-AMP1 provided by the present invention has excellent activity in relieving ulcerative colitis. The experimental results show that the DAI scores of mice in each group were treated with the antimicrobial peptide HsTx-AMP1 by enema, and the DAI scores of mice in each group showed that the DAI scores of the blank group mice (Control) did not increase during the modeling period, and the DAI scores of the modeling group mice (DSS) gradually increased from the third day, and were higher than those of the treatment group (HsTx-AMP1). With the increase of treatment time, different doses of HsTx-AMP1 reduced the DAI scores to varying degrees, and were concentration-dependent. At the end of the modeling on the 7th day, the DAI score of the high-dose HsTx-AMP1 group was significantly lower than that of the DSS group. The gross conditions of the colons of mice in each group showed that there were no obvious abnormalities in the colons of the blank group mice (Control), the colons of the modeling group mice (DSS) were significantly shorter than those of the blank group, and the colon length of the treatment group (HsTx-AMP1) was restored compared with the DSS group, and was concentration-dependent. The high-dose group (P < 0.0001) and the medium-dose group (P < 0.05) were statistically significantly different from the modeling group, and had a good recovery effect. The antimicrobial peptide HsTx-AMP1 provided by the present invention has an excellent alleviating effect on ulcerative colitis.

[0009] The antimicrobial peptide HsTx-AMP1 provided by the present invention is an antimicrobial peptide derived from a tropical rainforest scorpion, and has the common properties of antimicrobial peptides derived from scorpions: broad-spectrum action, strong activity, and not prone to drug resistance, etc., providing a new drug lead molecule for the research and development of ulcerative colitis drugs. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is the structural formula of the antimicrobial peptide HsTx-AMP1 of the present invention; Figure 2 The DAI score results of each group of DSS colitis mice are shown in the figure; Figure 3This is a graph showing the effect of the antimicrobial peptide HsTx-AMP1 of the present invention on the colon length of DSS colitis mice; Figure 4 This is a quantitative graph showing the effect of the antimicrobial peptide HsTx-AMP1 of the present invention on the colon length of DSS colitis mice. DETAILED DESCRIPTION

[0011] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited in any way. Any changes or improvements made based on the teachings of the present invention fall within the protection scope of the present invention.

[0012] The antimicrobial peptide HsTx-AMP1 of the present invention has an amino acid sequence of LWSFLFKAATKLLPSIFGGGKKSSSRR and a structural formula as shown Figure 1 shown.

[0013] The present invention further provides the use of the antimicrobial peptide HsTx-AMP1 in the preparation of a drug for treating ulcerative colitis or a drug for alleviating intestinal mucosal inflammation.

[0014] The present invention further provides a pharmaceutical composition for treating ulcerative colitis, comprising the antimicrobial peptide HsTx-AMP1 as a biologically active ingredient and a pharmaceutically relevant carrier thereof.

[0015] The present invention further provides a pharmaceutical composition for alleviating intestinal mucosal inflammation, which comprises the antimicrobial peptide HsTx-AMP1 as a biologically active ingredient and a pharmaceutically relevant carrier thereof.

[0016] Example 1 Synthesis of antimicrobial peptide HsTx-AMP1 The inventors have identified a series of peptide molecules with antibacterial activity from the venom of tropical rainforest scorpions, wherein the amino acid sequence of the antibacterial peptide HsTx-AMP1 is: LWSFLFKAATKLLPSIFGGGKKSSSRR, which can be prepared by conventional chemical synthesis or gene expression.

[0017] The antimicrobial peptide HsTx-AMP1 of the present invention was synthesized by Wuhan Baiyixin Biotechnology Co., Ltd. according to the designed HsTx-AMP1 structure ( Figure 1 ).

[0018] Example 2 Detection of the activity of antimicrobial peptide HsTx-AMP1 in alleviating colitis in DSS mice Experimental methods: Six C57BL / 6 male mice aged 6-8 weeks were randomly divided into a blank group (Control, PBS), a model group (DSS, PBS), a positive control group (Mesalazine (V Vifor AG ZweigniederlassungMedichemie Ettingen, H20150127, Switzerland)), and a treatment group, namely a HsTx-AMP1 low-dose group (1nM), a HsTx-AMP1 medium-dose group (10nM), and a HsTx-AMP1 high-dose group (100nM).

[0019] Except for the blank group, the other groups were allowed to freely drink 2.5% DSS solution to establish colitis mouse models. The blank group drank distilled water every day.

[0020] From the first day of mouse modeling, mice in the blank group and modeling group were enemaed with 100uL PBS once a day, mice in the control group were enemaed with Mesalazine 0.008 mL / g once a day, and mice in the treatment group were enemaed with 100uL of the corresponding drugs once a day. From the first day of modeling, the weight and stool characteristics of mice were recorded at the same time every day, and fecal occult blood test was performed by o-benzidine method. From the eighth day of mouse modeling, mice were killed by cervical dislocation, fixed on foam boards, opened the abdominal cavity, and slowly freed the complete colon from the anal canal, the lower end was cut off from the anal canal, and the upper edge was cut off from the ileocecal valve orifice. The length from the ileocecal valve to the anal canal was measured and photographed and recorded.

[0021] Results: Figure 2 As shown, with the increase of treatment time, different doses of HsTx-AMP1 reduced the DAI score to varying degrees, and it was concentration-dependent. At the end of the modeling on the 7th day, the DAI score of the HsTx-AMP1 high-dose group was significantly lower than that of the DSS group, and the DAI scores of the HsTx-AMP1 high-dose group and the medium-dose group were lower than those of the positive control group, indicating that the antimicrobial peptide HsTx-AMP1 of the present invention can significantly relieve intestinal mucosal inflammation of ulcerative colitis.

[0022] like Figure 3 , 4 As shown, the colon length of the treatment group (HsTx-AMP1) was restored compared with the DSS group, and it was concentration-dependent. The HsTx-AMP1 high-dose group (P < 0.0001) and the medium-dose group (P < 0.05) were statistically significantly different from the modeling group. The colon length of mice was significantly longer than that of the modeling group and better than that of the positive control group, indicating that the antimicrobial peptide of the present invention can restore the colon length of mice with ulcerative colitis, and the effect is better than that of the positive drug Mesalazine.

[0023] In summary, the antimicrobial peptide HsTx-AMP1 provided by the present invention has a good protective effect in ulcerative colitis and has certain drug development and clinical application value.

Claims

1. Antimicrobial peptide HsTx-AMP1, whose amino acid sequence is LWSFLFKAATKLLPSIFGGGKKSSSRR, and whose structural formula is shown in Formula I:

2. Use of the antimicrobial peptide HsTx-AMP1 according to claim 1 in the preparation of a drug for treating ulcerative colitis.

3. Use of the antimicrobial peptide HsTx-AMP1 according to claim 1 in the preparation of a drug for alleviating intestinal mucosal inflammation.

4. A pharmaceutical composition for treating ulcerative colitis, comprising the antimicrobial peptide HsTx-AMP1 according to claim 1 and a pharmaceutically relevant carrier thereof as a biologically active ingredient.

5. A pharmaceutical composition for relieving intestinal mucosal inflammation, comprising the antimicrobial peptide HsTx-AMP1 according to claim 1 and a pharmaceutically relevant carrier thereof as a biologically active ingredient.

Images