CN116059193A

CN116059193A - Application of butyric acid in preparation of medicine for treating anemia caused by inflammatory bowel disease

Info

Publication number: CN116059193A
Application number: CN202310243341.0A
Authority: CN
Inventors: 肖鹏; 徐俊杰; 沈舒滢
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2023-03-14
Filing date: 2023-03-14
Publication date: 2023-05-05

Abstract

The application provides application of butyric acid in preparation of a medicine for treating anemia caused by inflammatory bowel disease, and relates to the technical field of biology. Use of butyric acid in the manufacture of a medicament for the treatment of anaemia caused by inflammatory bowel disease, butyric acid in the present application promotes the formation of the open chromatin conformation of the promoter region of FPN by inhibiting the binding of Sp1 to HDAC1, so as to maintain the expression of FPN, thus reversing the symptoms of anaemia caused by enteritis. The application discovers that the regulation and control of the short chain fatty acid on macrophage iron metabolism for the first time, and relieves the effect of inflammatory anemia by promoting the output of macrophage iron ions. The application provides a new mode of regulating immune cell functions by flora metabolites in the intestinal microenvironment, and is expected to provide a potential new strategy for treating anemia of clinical IBD patients.

Description

Application of butyric acid in preparation of medicine for treating anemia caused by inflammatory bowel disease

Technical Field

The application relates to the field of biotechnology, in particular to application of butyric acid in preparation of a medicine for treating anemia caused by inflammatory bowel disease.

Background

Inflammatory bowel disease (Inflammatory Bowel Disease, IBD) is a chronic, repetitive inflammation of the intestinal tract, the typical symptoms of which mainly include abdominal pain, diarrhea, hematochezia, etc. In addition, intestinal inflammation can also cause a series of systemic symptoms, mainly manifested by weight loss, anemia, malnutrition, etc. Among them, inflammatory anemia (Anemia of inflammation, AI) is one of the most common complications of IBD patients, and can cause fatigue, headache, dizziness and other symptoms of the patients, which seriously affect the physical and mental health of the IBD patients. Over 70% of IBD patients are associated with anemia, most of which is manifested as iron deficiency anemia (Iron deficiency anemia, IDA), mainly caused by an imbalance in iron ion homeostasis caused by inflammation. Iron ions are one of the most important elements of life activities, and iron elements in the human body can be obtained from foods, are mainly stored in erythrocytes in the form of Hemoglobin (Hb), and are responsible for transporting oxygen. In addition, iron ions may also bind to transferrin (Tf), or be present in the serum and tissue microenvironment in the form of heme-blood binding elements, or hemoglobin-binding globin complexes. Due to metabolism, the body has a large number of red blood cells that age and die every day, so that enough iron ions (about 20 mg/day) are needed for the re-synthesis of hemoglobin. However, it is estimated that the human body ingests from the diet and that the iron absorbed via the intestinal tract is only 1-2 mg/day, so that the recycling of elemental iron becomes an important route for the supplementation of erythrocytes. The iron ion balance is precisely regulated in multiple links, and the normal expression and function of the iron metabolism related genes are necessary conditions for avoiding anemia. Currently, the molecular mechanism of iron ion imbalance in the environment of intestinal inflammation is not clear, and presumed causes include bleeding caused by ulcer of intestinal mucosa, abnormal cellular iron metabolism caused by inflammation, and the like. Aiming at the anemia symptoms of IBD patients, a treatment strategy of oral iron preparation or intravenous iron preparation is generally adopted, however, exogenous iron element supplement is only used for treating the symptoms, and the defects of low absorptivity, unstable curative effect, high intolerance rate and the like exist, and the risk of aggravating inflammatory reaction, mucosal injury and the like exists. Therefore, the mechanism of iron ion imbalance of the body caused by intestinal inflammation is deeply clarified, and corresponding treatment strategies are developed, so that the method is a primary factor for improving the anemia symptoms of IBD patients.

Disclosure of Invention

In order to solve the technical problems, the application of the butyric acid in preparing a medicine for treating anemia caused by inflammatory bowel disease is provided. Butyric acid in the present application can promote the formation of an open chromatin conformation of the FPN promoter region by inhibiting the binding of Sp1 and HDAC1, to maintain the expression of FPN, thereby reversing the symptoms of anemia due to enteritis.

The technical problem of the application is solved by adopting the following technical scheme.

In the early work, by constructing a DSS colitis model and treating butyric acid, butyric acid was found to reverse the symptoms of anaemia caused by enteritis. On the cytology level, the influence of butyric acid on the gene expression profile of macrophages is analyzed by using RNA-Seq, and the fact that in a plurality of iron metabolism related genes, iron exporting protein FPN can be obviously up-regulated by butyric acid induction, and the function is that the butyric acid treatment down-regulates the concentration of iron ions in macrophages.

At a mechanistic level, sp1 protein was found to be able to bind to the promoter of FPN and recruit HDAC1 to compact the chromatin structure of the FPN promoter region, inhibiting its transcription. Whereas butyrate promotes the formation of an open chromatin conformation of the FPN promoter region by inhibiting the binding of Sp1 and HDAC1, to maintain the expression of FPN, thereby reversing the symptoms of anemia due to enteritis.

Compared with the prior art, the embodiment of the application has at least the following advantages or beneficial effects:

the application discovers that the regulation and control of the short chain fatty acid on macrophage iron metabolism for the first time, and relieves the effect of inflammatory anemia by promoting the output of macrophage iron ions. Provides a new mode of regulating the immune cell function by flora metabolites in the intestinal microenvironment, and is expected to provide a potential new strategy for treating anemia of patients with clinical IBD.

In the mechanism layer, the Sp1 protein is first discovered in the present application to be capable of binding to the promoter of FPN, and recruits HDAC1 to compact the chromatin structure of the FPN promoter region, inhibiting its transcription. Whereas butyrate promotes the formation of an open chromatin conformation of the FPN promoter region by inhibiting the binding of Sp1 and HDAC1, to maintain the expression of FPN, thereby reversing the symptoms of anemia due to enteritis.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 shows the results of detection of the hematological index (hemoglobin, serum iron ions, and transferrin saturation levels) of a colitis model mouse in example 2 of the present application;

FIG. 2 shows the results of detection of colonic tissue iron ion levels in a colitis mouse in example 2 of the present application;

FIG. 3 shows the results of the detection of the hematological index (hemoglobin, serum iron ions and transferrin saturation level) of a model mouse with phenylhydrazine induced inflammation independent anemia in example 2 of the present application;

FIG. 4 shows the results of serum iron ion level and tissue iron ion level detection after injection of Iron Dextran (ID) into mice, induction of tissue iron retention, in example 2 of the present application;

FIG. 5 shows the results of hemoglobin, serum iron ions, and transferrin saturation levels of mice treated with butyric acid after removal of macrophages from mice in example 3 of the present application;

FIG. 6 shows the results of transcriptome sequencing iron metabolism-related gene expression in example 3 of the present application;

FIG. 7 shows the results of confocal laser microscopy imaging in example 3 of the present application;

FIG. 8 shows the expression level of FPN in butyrate-treated mice sorted from intestinal macrophages in example 3 of the present application;

FIG. 9 is a graph showing the results of flow cytometry in example 3 of the present application for detecting intracellular levels of iron ions;

FIG. 10 shows the results of the detection of FPN expression levels after treatment with each of the HDAC subtype inhibitors of example 4 of the present application;

FIG. 11 shows the results of the protein interaction selected from the STRING database in example 4 of the present application;

FIG. 12 shows the results of the analysis of the Sp1 binding site of the FPN promoter region in example 4 of the present application;

FIG. 13 shows the expression level of FPN after MTM treatment in example 4 of the present application;

FIG. 14 shows iron levels in macrophages after MTM treatment in example 4 of the present application;

FIG. 15 is the results of co-immunoprecipitation CoIP experiments in example 4 of the present application;

FIG. 16 shows the results of the detection of hematological indicators (hemoglobin, serum iron ions, and transferrin saturation levels) in mice after intraperitoneal injection of MTM in example 4 of the present application;

FIG. 17 shows the results of detection of colonic tissue iron ion levels in colitis mice in example 4 of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The present application will be described in detail with reference to specific examples.

The embodiment of the application provides an application of butyric acid in preparing a medicine for treating anemia caused by inflammatory bowel disease.

In some embodiments of the present application, the butyric acid modulates FPN expression in macrophages by affecting the binding of HDAC and Sp 1.

In some embodiments of the present application, the Sp1 protein described above binds to the promoter of the FPN and recruits the HDAC1 such that the FPN promoter region chromatin structure is compact, inhibiting its transcription.

The features and capabilities of the present application are described in further detail below in connection with the examples.

Example 1

The embodiment is a research method and experimental means in the application

1. Mouse model part

1. Construction of enteritis model

2.5% DSS was added to drinking water of 8-10 week old wild type C57BL/6 mice. Based on the DSS group described above, sodium butyrate was dissolved in the drinking water of mice to a final concentration of 150mM. DSS was fed to the die at day 7.

2. Macrophage conditional FPN knockout mouse construction

And mating the FPNflox/flo mice with LysMCre mice to obtain LysMCre/FPNflox/flox mice, namely macrophage conditional FPN knockout mice. Subsequent experiments were performed with littermate FPNflox/flox mice as wild-type controls.

3. Hematology index detection

mu.L of mouse peripheral blood was mixed with 500. Mu.L of PBS (containing 0.5mM EDTA) and detected on a Sysmex KX-21N Automated Hematology Analyzer instrument.

4. Serum iron ion concentration detection

Collecting peripheral blood of mice by adopting an eyeball blood taking method, standing for 2 hours at room temperature, centrifuging for 5 minutes at 4 ℃ after coagulation, and taking supernatant as serum. The detection was performed according to the instructions using a serum iron ion concentration detection kit (solarBio).

5. Immunofluorescent staining

The colon tissue of the mice was placed in 4% paraformaldehyde and fixed overnight at 4 ℃. Then, 10%, 20% and 30% sucrose are used for gradient dehydration, and OCT embedding is frozen at-80 ℃. Frozen sections of 8 μm thickness were prepared on a microtome and cell rupture was performed with 0.2% Triton. After blocking, the corresponding primary antibody was added and incubated overnight at 4 ℃. The primary antibody is washed off the next day, fluorescent coupling secondary antibody is added for incubation for 1h at room temperature, and the chip is sealed after the DAPI counterstaining for 5 min. Imaging was taken under a Confocal microscope.

6. Tissue iron ion staining

Tissue iron deposition was detected using a Perls staining kit following a protocol.

7. Phenylhydrazine induced anemia model construction

Mice were given pre-drink with butyric acid for 3 days, after which phenylhydrazine (40 μg/g body weight) was injected intraperitoneally for two consecutive days. And then collecting peripheral blood of the mice, and detecting blood serum iron ion concentration and other blood indexes.

2. Cell and molecular experiment

1. Macrophage (BMDM) induction and intestinal macrophage sorting

BMDM induction: mice are sacrificed by cervical dislocation, four mice leg bones are taken, and bone marrow cells are blown out by a syringe. After centrifugation and erythrocyte lysis, the cells are spread in a 6-well plate, and then are cultured by adding DMEM medium containing 10ng/mL macrophage colony stimulating factor (M-CSF), 2mL of fresh medium is supplemented in the third day, the liquid is completely changed in the fifth day, and macrophages are mature in the seventh day. After digestion with pancreatin (EDTA-containing), counts were counted and re-plated for use.

Intestinal macrophage sorting: after taking out the intestinal tissue, the feces are blown out and cut longitudinally. Removing intestinal epithelial cells through EDTA+DTT incubation; cutting the lamina propria, decomposing 400U/ml IV collagenase into single cell suspension, and obtaining intestinal macrophages by adopting an anti-F4/80 magnetic bead sorting method.

2. Macrophage butyric acid treatment and LPS stimulation

The obtained macrophages were treated with different concentrations of butyric acid (0.5-5 mM) and time-gradient was set to detect FPN expression. In the anti-inflammatory effect study of butyric acid, detection of intracellular iron ion concentration, supernatant TNF-alpha and other inflammatory factors levels was performed after stimulation with 1. Mu.g/ml LPS (or other TLR ligands such as PGN, polyI: C). In addition, macrophages are pretreated with various inhibitors as required by the experiment.

3. Intracellular iron ion concentration detection

The stimulated macrophages were gently rinsed 2 times with 1mL cold PBS, followed by instructions using a QuantiChromTM Iron Assay Kit (Bioassay Systems) kit.

4. Fluorescent quantitative QPCR and RNA-Seq

Extracting total RNA of cells by using a Trizol method, and carrying out reverse transcription to obtain cDNA by using a Toyobo reverse transcription kit after quantification. Kit (kang) using UltraSYBR MixtureCentury) was subjected to QPCR reactions. The conditions were as follows: 95 ℃ for 10min; (95 ℃ C. 15s;60 ℃ C. 50 s) X40 cycles. The beta-action gene is used as an internal reference, and the result adopts 2 ^-ΔΔCT The method was used for analysis. In RNA-Seq experiments, macrophages were plated in 6cm dishes for culture, stimulated with butyric acid, lysed with 1mL Trizol, and sent to a third party entity (Bio Inc.) for RNA-Seq detection analysis.

5、Western blot

Placing the stimulated cells on ice, gently scraping the cells, adding RIPA lysate, lysing for 1h at 4 ℃, quantifying the total protein by BCA method, adding SDS loading buffer, and boiling for 5min at 100 ℃ to denature the protein. The total cell proteins were subjected to polyacrylamide gel electrophoresis (SDS-PAGE), transferred and blocked, and incubated overnight at 4℃with the corresponding primary antibody. The next day was incubated with HRP conjugated secondary antibody for 1h at room temperature and the strips were developed by exposure.

6. Co-immunoprecipitation test (CoIP)

After treatment of macrophages with butyric acid, the cells were scraped off on ice during RIPA lysis. The cells were lysed by incubating for 30min at 4℃with a flip shaker, after which the supernatant was centrifuged. Transfer to a new 1.5ml EP tube (about one tenth of the volume was taken as Input), incubate overnight with Sp1, HDAC1 or p300 antibodies on a 4 ℃ flip shaker, after which Protein A agarose magnetic beads were added to bind to antigen-antibody complexes, incubate overnight on a 4 ℃ flip shaker. Centrifuging to remove supernatant, enriching magnetic bead-antigen-antibody complex on a magnetic rack, washing with RIPA lysate for three times, re-suspending the precipitate with loading buffer, and boiling to denature protein. Western blot detection was performed after SDS-PAGE.

Example 2

This example is a discussion of experimental data analysis and results demonstrating that supplementation with butyric acid can alleviate iron deficiency anemia.

The only known protein responsible for iron ion output is iron transporter (FPN), and the decrease of expression leads to accumulation of iron ions in cells, so that the available iron level of the organism is reduced, and the synthesis of hemoglobin is blocked, thereby causing anemia. To verify whether butyric acid can alleviate iron deficiency anemia, mice were first given DSS treatment to constructColitis model, with butyric acid added to the drinking water of mice at 150mM. After 8 days, the mice were tested for hematology index, including hemoglobin concentration, serum iron ion, transferrin saturation, and the test results are shown in fig. 1. H in FIG. 1 ₂ The group O is a blank group (all healthy mice, no modeling is performed), the group DSS is a colitis model group, and as can be seen from fig. 1, compared with the control group, in the group DSS model group (experimental group) treated by butyric acid (BR), the hemoglobin concentration, serum iron ions and transferrin saturation in the mice are greatly improved, and the experimental results show that the butyric acid treatment significantly reverses the decrease of the hemoglobin, serum iron ions and transferrin saturation level caused by enteritis.

Further, the colon tissue of the colon inflammatory mice is subjected to iron ion detection, and the iron level of the colon tissue is detected, and the detection result is shown in figure 2. H in FIG. 2 ₂ Group O is a blank group (all healthy mice, no modeling), DSS is a colitis model group, and as can be seen from fig. 2, colonic tissue iron ion levels of colitis mice are significantly elevated compared to healthy mice, demonstrating that inflammation can lead to tissue iron retention, while butyric acid treatment significantly reverses this phenomenon.

Further, a Phenylhydrazine (PH) induced inflammation independent anemia model is constructed, and the hematological indexes of the mice, including the hemoglobin concentration, serum iron ions and transferrin saturation, are detected, and the detection results are shown in figure 3. From fig. 3, it can be seen that butyric acid was found to reverse the above anemia index as well.

Further, iron Dextran (ID) was injected into the mice to induce tissue iron retention, and then butyric acid treatment was performed on the mice to detect serum iron ion levels and tissue iron ion levels in the mice, and the results are shown in fig. 4. As can be seen from fig. 4, butyrate treatment significantly up-regulated serum ferric ion levels, while down-regulated tissue ferric ion levels.

Taken together, these three models demonstrate that butyric acid inhibits the retention of iron ions in tissues, thereby increasing the levels of available iron in the body and thus alleviating the symptoms of anemia.

Example 3

Further, the mouse macrophages were knocked out by intraperitoneal injection with chlorophosphate-liposome, and then butyric acid injection was performed on the mice to detect hemoglobin, serum iron ions, and transferrin saturation levels, and the results are shown in fig. 5. As can be seen from fig. 5, when macrophages are removed, butyric acid can no longer affect the hemoglobin, serum iron ions, and transferrin saturation levels of DSS colitis mice, and the above experimental results indicate that the effect of butyric acid to alleviate anemia depends on macrophage function.

The mice were then treated with butyric acid again, and the results of transcriptome sequencing (RNA-Seq) iron metabolism-related gene expression were shown in FIG. 6. The stronger blue in FIG. 6 indicates lower gene expression levels, and the stronger yellow indicates higher gene expression levels, and it can be seen from FIG. 6 that the level of FPN (encoding gene SLC40A 1) is significantly up-regulated after butyrate treatment, while the other genes are not significantly changed.

Again, laser micro-Confocal imaging (cofocal) confirmed that butyric acid significantly enhanced macrophage FPN expression (as shown in fig. 7). In the figure, green fluorescence indicates FPN expression, and the clear increase in green fluorescence after butyric acid treatment indicates an increase in FPN expression. Blue is DAPI, labeled nuclei.

The macrophages were sorted from the intestinal tract of DSS colitis mice and butyric acid treatment was found to significantly enhance the expression level of colophagic FPN in the intestinal tract of the mice (as shown in fig. 8).

Flow cytometry was used to detect intracellular levels of iron ions (higher numbers represent lower levels of iron ions) using Calcein-AM staining, and butyric acid treatment was found to significantly down-regulate levels of iron ions in macrophages. On the other hand, in the case of adding ferric citrate (FAC), an increase in intracellular iron ion level, i.e., iron retention, occurs, and butyric acid significantly alleviates this phenomenon (as shown in fig. 9). The left panel in FIG. 9 is a flow chart of Calcetin-AM staining, with the right signal peak representing higher fluorescence intensity of Calcetin-AM and reflecting lower concentration of iron ions in the cells. The right panel in FIG. 9 shows the quantification result of the left panel, and the ordinate shows the fluorescence intensity of Calcein-AM.

Example 4

This example is a study of the molecular mechanism by which butyrate induces FPN expression.

At present, the regulation and control of the Buty on gene expression are mainly realized by three modes: 1. as a signaling molecule, binds to a specific GPCR (G-protein coupled receptor), such as GPR109A, thereby activating activation of downstream transcription factors; 2. as histone deacetylase inhibitors (HDACI), enhancing the level of protein acetylation of a specific gene promoter region, inducing the formation of an open chromatin conformation, promoting gene expression; buty can participate in metabolic pathways such as fatty acid oxidation (Fatty Acid Oxidation, FAO) in mitochondria, and can regulate gene expression and cell functions by affecting cellular energy metabolism. It was found experimentally that the GPCR agonist Niacin did not promote FPN expression, nor did the blocking of GPCR signaling with Pertussis Toxin (PT) reduce the FPN-inducing effect of butyrate (as shown in fig. 10 a). Furthermore, the use of the fatty acid oxidation inhibitor etomoxir also fails to counteract the induction effect of butyric acid on FPN (as shown in B in fig. 10). On the other hand, the use of the HDAC inhibitor TSA had a similar effect to butyric acid (as shown in fig. 10C). By further using each HDAC subtype specific inhibitor, it was found that blocking the effect of type I HDAC (HDAC 1/2/3) could significantly up-regulate FPN expression, blocking the induction effect of type IIa HDAC (HDAC 4/5/7/9) on FPN was weaker. However, blocking type IIb HDAC (HDAC 6), type III HDAC (SIRTs), and type IV HDAC (HDAC 11) did not significantly up-regulate FPN levels (as shown in FIG. 10D), enti was a type I HDAC inhibitor, TMP was a type IIa HDAC inhibitor, roc was a type IIb HDAC inhibitor, nicots was a type III HDAC inhibitor, SIS was a type IV HDAC inhibitor in FIG. 10. The above experimental results indicate that butyric acid promotes the expression of FPN mainly by inhibiting HDAC type I.

The above experimental results indicate that butyric acid may promote FPN expression by inhibiting HDAC1 activity of FPN promoter region. To find key proteins mediating this effect, 32 protein elements were predicted by the Jaspar database to bind to the FPN promoter region, and 100 proteins were identified by the sting database to bind to HDAC1 (taking the protein of 100 before the binding score), and Sp1 protein was found to be at the intersection of the two databases (as shown in fig. 11). Further analysis showed that the FPN promoter region contained 3 high scoring Sp1 binding sites (as shown in fig. 12), and that Sp1 could be localized to the FPN promoter, preventing the formation of open chromatin structure by binding to HDAC1, thereby down-regulating FPN transcription. To verify this hypothesis, the DNA binding capacity of Sp1 was inhibited with Mithramycin a (MTM), which was found to significantly up-regulate macrophage FPN expression. In addition, butyrate was unable to further up-regulate FPN expression in the presence of MTM, and both did not act synergistically, suggesting that butyrate promoted FPN expression by inhibiting HDAC1 binding to Sp1 (as shown in fig. 13). Calcetin-AM staining showed that MTM treatment reduced the concentration of iron ions in macrophages, and intracellular accumulation of inhibitor iron (as shown in FIG. 14, the ordinate represents the fluorescence intensity of Calcetin-AM dye, the lower the iron ion level, the higher the fluorescence intensity of Calcetin-AM) and FIG. 14 shows that after MTM treatment, the fluorescence intensity of Calcetin-AM significantly increased, representing a decrease in iron ion concentration. Also through co-immunoprecipitation CoIP experiments, it was found that Sp1 and HDAC1 in macrophages did bind, and the interaction of both could be significantly inhibited by butyric acid (as shown in FIG. 15).

To further verify the mechanism by which butyrate promotes FPN expression by inhibiting the binding of Sp1 to HDAC1, DSS treatment was given to mice to construct a model of colitis, while MTM was given intraperitoneally to the mice to inhibit Sp1 activity. After 8 days, the mice were tested for hematology index, including hemoglobin concentration, serum iron ions, transferrin saturation, and the results are shown in fig. 16. As can be seen from fig. 16, MTM administration significantly reversed the decrease in hemoglobin, serum iron, transferrin saturation levels caused by enteritis.

Further, the colonic tissue iron levels were measured, and as shown in fig. 17, it was found that colonic tissue iron levels were significantly elevated in colitis mice compared to healthy mice, demonstrating that inflammation could lead to tissue iron retention. Whereas MTM treatment significantly reversed this phenomenon.

The above results further demonstrate that inhibiting Sp1 activity can alleviate anemia, while butyric acid can promote FPN expression by inhibiting the binding of Sp1 to HDAC1, thereby alleviating the symptoms of anemia.

In summary, the application of butyric acid in the embodiment of the present application in preparing a medicament for treating anemia caused by inflammatory bowel disease, in terms of mechanism, the Sp1 protein is first discovered to be capable of binding to a promoter of FPN in the present application, and HDAC1 is recruited to tighten chromatin structure of a promoter region of FPN, and inhibit transcription thereof. Whereas butyrate promotes the formation of an open chromatin conformation of the FPN promoter region by inhibiting the binding of Sp1 and HDAC1, to maintain the expression of FPN, thereby reversing the symptoms of anemia due to enteritis.

The embodiments described above are some, but not all, of the embodiments of the present application. The detailed description of the embodiments of the present application is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

Claims

1. Use of butyric acid in the preparation of a medicament for treating anemia caused by inflammatory bowel disease.

2. The use of butyric acid according to claim 1, for the preparation of a medicament for the treatment of anemia caused by inflammatory bowel disease, wherein said butyric acid modulates FPN expression in macrophages by affecting the binding of HDAC and Sp1 proteins.

3. The use of butyric acid according to claim 2, wherein said Sp1 protein binds to the promoter of said FPN and recruits said HDAC1 to compact the chromatin structure of the promoter region of said FPN, inhibiting its transcription, for the preparation of a medicament for the treatment of anaemia caused by inflammatory bowel disease.