Application of VEGF-B (vascular endothelial growth factor-B) in increasing intramuscular fat content of pig

Abstract

The invention relates to the technical field of animal nutrition and meat quality regulation and control, in particular to application of a vascular endothelial growth factor B (VEGF-B) in increasing the fat content in pig muscle. The content of the VEGF-B in pig serum and the expression level of the VEGF-B in skeletal muscle tissue are in significant positive correlation with the fat content in the pig muscle, so that the VEGF-B can be used as a biomarker for predicting the fat content in the pig muscle; meanwhile, the fish oil rich in n-3 polyunsaturated fatty acids can promote the VEGF-B expression level by activating a G protein coupled receptor 120 (GPR120), so that the transvascular endothelial transport of fatty acids in blood vessels to skeletal muscles is increased, and finally the intramuscular fat content is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of animal nutrition and meat quality control, and in particular to the application of vascular endothelial growth factor B (VEGF-B) in increasing the intramuscular fat content of pigs. Background Art

[0002] In modern pig farming, pork quality is a key factor affecting industrial development and market competitiveness. Intramuscular fat (IMF) content is an important indicator of pork quality, including flavor, tenderness, and juiciness. Currently, increasing IMF content in pigs through genetic breeding and nutritional regulation has become a research hotspot in animal production and meat science. Traditional breeding methods rely primarily on the selection of phenotypic traits and the assistance of genetic markers, but these methods are characterized by long breeding cycles, high costs, and the potential for negative impacts on other production performance characteristics of pigs, making it difficult to achieve precise and controllable regulation of IMF.

[0003] In recent years, nutritional regulation has been increasingly applied to the study of intramuscular fat deposition. Fish oil, rich in n-3 polyunsaturated fatty acids, has been shown to regulate animal fat metabolism. However, due to the lack of understanding of the specific mechanisms by which fish oil influences animal fat metabolism, precise regulation of intramuscular fat content in pigs to improve pork quality remains elusive. Summary of the Invention

[0004] The purpose of the present invention is to avoid the shortcomings of the existing technology and provide the use of vascular endothelial growth factor B (VEGF-B) in increasing the intramuscular fat content of pigs. It was found that the content of VEGF-B in pig serum and its expression level in skeletal muscle are significantly positively correlated with the content of intramuscular fat in skeletal muscle tissue, and the intramuscular fat content of pigs can be increased by promoting the expression level of VEGF-B.

[0005] To achieve one of the above objectives, the present invention provides the following technical solutions:

[0006] The present invention provides the application of VEGF-B as a biomarker in predicting pig intramuscular fat content. The content of VEGF-B in pig serum and the expression level in skeletal muscle tissue are positively correlated with pig intramuscular fat content.

[0007] In some embodiments, the receptors of VEGF-B include VEGFR1 and NRP1, and VEGFR1 and NRP1 are used as biomarkers to predict the intramuscular fat content of pigs. The expression levels of VEGFR1 and NRP1 in pig skeletal muscle tissue are positively correlated with the intramuscular fat content of pigs.

[0008] Beneficial effects of using VEGF-B as a biomarker in predicting pig intramuscular fat content:

[0009] The application of VEGF-B as a biomarker in predicting the intramuscular fat content of pigs found that the content of VEGF-B in pig serum and its expression level in skeletal muscle were significantly positively correlated with the content of intramuscular fat in pig skeletal muscle tissue. It can predict the intramuscular fat content of pigs and then evaluate the potential of intramuscular fat deposition in pigs, providing important reference indicators for pig breeding and production.

[0010] To achieve the second of the above objectives, the present invention provides the following technical solutions:

[0011] Provides the use of VEGF-B in increasing pig intramuscular fat content, upregulating VEGF-B expression, thereby promoting skeletal muscle fat deposition to increase pig intramuscular fat content;

[0012] In some embodiments, VEGF-B expression is upregulated by activating the GPR120 signaling pathway;

[0013] Beneficial effects of the application of VEGF-B in the present invention in increasing the intramuscular fat content of pigs:

[0014] The present invention discloses the application of VEGF-B in regulating and increasing the intramuscular fat content of pigs. It is found that the content of VEGF-B in pig serum and its expression level in skeletal muscle are positively correlated with the content of intramuscular fat in pig skeletal muscle tissue. VEGF-B can indirectly increase the deposition level of fatty acids in muscle tissue by promoting the transport of intravascular fatty acids across vascular endothelial cells to skeletal muscle cells, so that VEGF-B plays a bridging role in the formation of intramuscular fat. This provides a new target for achieving precise regulation of intramuscular fat and a theoretical basis for regulating fat metabolism in pigs.

[0015] To achieve the third of the above objectives, the present invention provides the following technical solutions:

[0016] A nutritional regulation method for increasing pig intramuscular fat content is provided. n-3 polyunsaturated fatty acids are administered to pigs to activate the GPR120 signaling pathway. The GPR120 signaling pathway upregulates the expression of VEGF-B, thereby increasing the pig intramuscular fat content.

[0017] In some embodiments, n-3 polyunsaturated fatty acids are administered to pigs by feeding them fish oil containing n-3 polyunsaturated fatty acids.

[0018] In some embodiments, the pigs are fed a feed that includes fish oil containing n-3 polyunsaturated fatty acids, thereby administering fish oil containing n-3 polyunsaturated fatty acids to the pigs.

[0019] Beneficial effects of the nutritional regulation method for increasing pig intramuscular fat content of the present invention:

[0020] (1) The present invention discloses a nutritional regulation method for increasing pig intramuscular fat content. It is found that n-3 polyunsaturated fatty acids increase the VEGF-B content in pig serum or the expression of VEGF-B in skeletal muscle by activating the GPR120 signaling pathway, thereby promoting the transport of intravascular fatty acids across vascular endothelial cells to skeletal muscle cells, and ultimately promoting the deposition of fatty acids in muscle cells. Therefore, by using n-3 polyunsaturated fatty acids for precise nutritional intervention, pig intramuscular fat can be increased, which is applicable to multiple directions such as genetic improvement, healthy breeding and animal nutrition regulation, and overcomes the problem of low efficiency of intramuscular fat deposition in the prior art.

[0021] (2) The nutritional regulation method for increasing the intramuscular fat content of pigs of the present invention adopts the natural active ingredient n-3 polyunsaturated fatty acids, which can significantly increase the intramuscular fat content of pigs without hormone or transgenic intervention, thereby improving the quality of pork, and has the effects of simple regulation operation, low cost and green environmental protection.

[0022] Also provided is a nutrient for increasing the intramuscular fat content of pigs, comprising n-3 polyunsaturated fatty acids. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the experimental comparison result diagram of Experimental Example 1.

[0024] Figure 2 This is the experimental comparison result diagram of Experimental Example 2.

[0025] Figure 3 This is the experimental comparison result of Experiment 3 DETAILED DESCRIPTION

[0026] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to make the present invention more thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0027] Example 1

[0028] This example discloses the use of VEGF-B as a biomarker in predicting pig intramuscular fat content. The content of VEGF-B in pig serum and its expression level in skeletal muscle tissue are significantly positively correlated with pig intramuscular fat content.

[0029] VEGF-B also has receptors. The expression levels of VEGF-B receptors VEGFR1 and NRP1 in pig skeletal muscle tissue are positively correlated with the intramuscular fat content of pigs.

[0030] VEGF-B as a biomarker can evaluate and regulate changes in pig intramuscular fat content. By detecting the expression levels of VEGF-B or VEGF-B receptors VEGFR1 and NRP1 in pig muscle tissue, the intramuscular fat content can be predicted and guided.

[0031] Furthermore, by detecting the expression level of VEGF-B-related proteins in pig muscle tissue, especially the longissimus dorsi muscle tissue, the intramuscular fat content of pigs can be effectively and accurately predicted; among them, when the protein expression level of VEGF-B or the VEGF-B receptors VEGFR1 and NRP1 are high, the intramuscular fat content of pigs is correspondingly higher.

[0032] In practice, precise detection of VEGF-B expression levels in pig skeletal muscle tissue or serum VEGF-B levels can sensitively and accurately assess the potential for intramuscular fat deposition in pigs. This provides a reliable scientific basis for genetic selection and precise feeding management, helping to identify pig breeds with higher potential for intramuscular fat deposition, thereby improving pork quality from the source.

[0033] Example 2

[0034] This example discloses the use of VEGF-B in increasing pig intramuscular fat content, which can upregulate the expression of VEGF-B, thereby promoting the transport of intravascular fatty acids across vascular endothelial cells to skeletal muscle cells, and ultimately increasing skeletal muscle fat deposition to increase pig intramuscular fat content;

[0035] Among them, the expression of VEGF-B is upregulated by activating the GPR120 signaling pathway.

[0036] It was found that the content of VEGF-B in pig serum and its expression level in skeletal muscle were significantly positively correlated with the content of intramuscular fat in pig skeletal muscle tissue. VEGF-B can indirectly increase the deposition level of fatty acids in muscle tissue by promoting the transport of intravascular fatty acids across vascular endothelial cells to skeletal muscle cells, making VEGF-B play a bridging role in the formation of intramuscular fat, providing a new target for the precise regulation of intramuscular fat and a theoretical basis for the regulation of fat metabolism in pigs.

[0037] Example 3

[0038] This embodiment discloses a nutritional regulation method for increasing the intramuscular fat content of pigs, wherein n-3 polyunsaturated fatty acids are administered to pigs to activate the GPR120 signaling pathway, thereby increasing the intramuscular fat content of pigs.

[0039] Specifically, the method involves adding fish oil rich in n-3 polyunsaturated fatty acids to pig feed. The fish oil activates the GPR120 signaling pathway, inducing VEGF-B secretion from myotubes. VEGF-B acts paracrine-like on vascular endothelial cells, promoting their uptake and transendothelial transport of fatty acids, thereby increasing the amount of fatty acids entering skeletal muscle cells and ultimately increasing intramuscular fat content.

[0040] From the perspective of nutritional regulation, the n-3 polyunsaturated fatty acids rich in fish oil are utilized, especially docosahexaenoic acid (DHA). N-3 polyunsaturated fatty acids can, by virtue of their unique molecular structure and biological activity, specifically act on relevant cell signaling pathways in the body, i.e., the GPR120 signaling pathway, to achieve upregulation of VEGF-B expression. As the expression level of VEGF-B increases, the transport function of vascular endothelial cells for fatty acids is significantly activated, prompting more fatty acids to efficiently cross the vascular endothelial barrier and enter the muscle tissue for deposition, thereby achieving precise regulation of pig intramuscular fat. The present invention provides new biomarkers and nutritional intervention strategies for improving pork quality.

[0041] Therefore, by adding fish oil components rich in n-3 polyunsaturated fatty acids (such as DHA) to pig feed, the expression of VEGF-B in pig skeletal muscle or VEGF-B in serum can be upregulated, thereby enhancing the transport of intravascular fatty acids across vascular endothelial cells to skeletal muscle cells, and ultimately promoting the deposition of fatty acids in muscle cells.

[0042] The use of fish oil ingredients rich in n-3 polyunsaturated fatty acids (such as DHA) to upregulate VEGF-B expression levels aims to indirectly increase the intramuscular fat content of pigs by regulating the fatty acid supply capacity in the local microenvironment of skeletal muscle, thereby achieving precise intervention in quality characteristics such as pork marbling and flavor.

[0043] In this example, n-3 polyunsaturated fatty acids were administered to pigs by feeding them fish oil containing n-3 polyunsaturated fatty acids.

[0044] In this embodiment, the fish oil is added to feed, and the feed including the fish oil containing n-3 polyunsaturated fatty acids is fed to pigs, thereby feeding the pigs with fish oil containing n-3 polyunsaturated fatty acids.

[0045] Example 4

[0046] This embodiment discloses a nutrient for increasing the intramuscular fat content of pigs. The nutrient contains n-3 polyunsaturated fatty acids. Administration of the nutrient to pigs can increase the intramuscular fat content of pigs.

[0047] Experimental test:

[0048] To further illustrate the reliability of the application of VEGF-B of the present invention in increasing the intramuscular fat content of pigs, the following experiments were conducted:

[0049] Experimental Example 1

[0050] To verify the correlation between VEGF-B and intramuscular fat deposition, pig groups with obvious differences in intramuscular fat content were selected, and their longissimus dorsi muscles were collected. The protein expression levels of VEGF-B were detected by WB, and the correlation between VEGF-B and intramuscular fat content in the tissue was analyzed. Figure 1 Figure 3, (A) shows the intramuscular fat content in the longissimus dorsi muscle of Guangdong black pigs; (B) shows the Oil Red O staining image of Guangdong black pig muscles; (C) shows the VEGF-B content in the serum of Guangdong black pigs; (D) shows the TG (triglyceride) content in the serum of Guangdong black pigs; (E) shows the correlation analysis between the intramuscular fat content and the VEGF-B content in the serum; (FG) shows the differences in the expression of VEGFs, their receptor signaling proteins, and GPR120 protein in the longissimus dorsi muscle of Guangdong black pigs and their statistical graphs.

[0051] Depend on Figure 1 It can be seen that the protein expression level of VEGF-B in the control group with low intramuscular fat content (control) is lower than that in the experimental group with high intramuscular fat content (High-IMF); the VEGF-B level in pig serum is significantly positively correlated with the intramuscular fat content (IMF content), indicating that VEGF-B can be used as a biomarker to predict or evaluate the intramuscular fat content of pigs.

[0052] Experimental Example 2

[0053] A co-culture system of myotube cells and vascular endothelial cells was constructed to systematically explore the direct and indirect regulatory effects of DHA, the main fatty acid in fish oil, on skeletal muscle lipid deposition by regulating VEGF-B signaling and its molecular mechanism.

[0054] like Figure 2 As shown in Figures AB and CF, DHA treatment significantly upregulated the expression level of GPR120 in myotubes, while inducing increased expression and secretion of VEGF-B (CF). Furthermore, in a co-culture system of myotubes and vascular endothelial cells, it was observed that DHA treatment significantly enhanced the fatty acid uptake and transmembrane transport capacity of vascular endothelial cells (GJ). This change effectively improved the supply of fatty acids from vascular endothelial cells to myotubes (KL). The above results indicate that DHA can upregulate the expression of VEGF-B in myotubes by activating GPR120, and then enhance the uptake and transport of fatty acids by vascular endothelial cells in a paracrine manner, ultimately increasing the fatty acid supply to muscle cells, revealing the indirect mechanism of action of DHA in promoting skeletal muscle lipid deposition.

[0055] Experimental Example 3

[0056] Effects of n-3 polyunsaturated fatty acids on skeletal muscle lipid deposition:

[0057] Twenty-four 5-week-old C57BL / 6J male mice were purchased and randomly divided into two groups (n=12), namely the control group (Control) and the group (Fish oil) administered with fish oil containing n-3 polyunsaturated fatty acids. The experiment lasted for 12 weeks. The control group and the group administered with fish oil were fed a basal maintenance diet, while the mice in the group administered with fish oil (10 μL / g body weight) were administered with fish oil every other day. During the experiment, the mice were placed in a 12-hour light-dark cycle at a temperature of 23°C ± 3°C and a humidity of 70% ± 10%, with free access to water and food. During the experiment, the weight, food intake and other data of the mice were recorded regularly, and the lipid deposition in the skeletal muscle of the mice was subsequently tested.

[0058] Depend on Figure 3 As shown in Figures 4 and 5, (AB) are Oil Red O staining and statistical graphs of the tibialis anterior muscles of the control group and mice that were given fish oil for a long time, showing that n-3 polyunsaturated fatty acids can effectively increase the amount of fat deposits in the skeletal muscles of mice; (C) is the determination of triglyceride content in the tibialis anterior muscles of the control group and mice that were given fish oil for a long time, showing that n-3 polyunsaturated fatty acids can effectively increase the triglyceride content of mice; (D) is the TG content in the serum of the control group and mice that were given fish oil for a long time, showing that n-3 polyunsaturated fatty acids can effectively increase the TG content of mice; (E) is the NEFA (non-esterified fatty acid) content in the serum of the control group and mice that were given fish oil for a long time, showing that n-3 polyunsaturated fatty acids can effectively increase the non-esterified fatty acid content of mice; (F) is the VEGF-B content in the serum of the control group and mice that were given fish oil for a long time, showing that n-3 polyunsaturated fatty acids can effectively increase the VEGF-B content in mice; (GH) is the difference in the expression of VEGF-B and its receptor signaling proteins between the control group and mice that were given fish oil for a long time, showing that n-3 polyunsaturated fatty acids can effectively increase the expression of VEGF-B and its receptor signaling proteins in mice.

[0059] Figure 3 This indicates that n-3 polyunsaturated fatty acids can be used to increase the intramuscular fat content of pigs and improve the market value of pork.

[0060] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. Application of VEGF-B as a biomarker in predicting pig intramuscular fat content. The level of VEGF-B in pig serum or expression level in skeletal muscle tissue is significantly positively correlated with pig intramuscular fat content.

2. The use of VEGF-B as a biomarker in predicting pig intramuscular fat content according to claim 1, characterized in that: The receptors of VEGF-B include VEGFR1 and NRP1. VEGFR1 and NRP1 are also used as biomarkers to predict the intramuscular fat content of pigs. The expression levels of VEGFR1 and NRP1 in pig skeletal muscle tissue are positively correlated with the intramuscular fat content of pigs.

3. The application of VEGF-B in increasing the intramuscular fat content of pigs can upregulate the expression of VEGF-B and thus promote skeletal muscle fat deposition.

4. The application of VEGF-B in increasing pig intramuscular fat content according to claim 3, characterized in that It upregulates VEGF-B expression by activating the G protein-coupled receptor 120 (GPR120) signaling pathway.

5. A nutritional regulation method for increasing the intramuscular fat content of pigs, characterized in that: Administration of n-3 polyunsaturated fatty acids to pigs activates the GPR120 signaling pathway, which upregulates VEGF-B expression and thus increases intramuscular fat content in pigs.

6. The nutritional control method for increasing pig intramuscular fat content according to claim 5, wherein: n-3 polyunsaturated fatty acids were administered to pigs by feeding them fish oil containing n-3 polyunsaturated fatty acids.

7. The nutritional control method for increasing pig intramuscular fat content according to claim 5, characterized in that: n-3 polyunsaturated fatty acids are administered to pigs by administering a feed comprising fish oil containing n-3 polyunsaturated fatty acids.

8. A nutritional agent for increasing the intramuscular fat content of pigs, characterized in that: Contains n-3 polyunsaturated fatty acids.

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