Use of vegf-b to increase intramuscular fat content in swine

Abstract

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

Description

TECHNICAL FIELD

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

[0002] In modern pig industry, pork quality is one of the key factors affecting the development of the industry and market competitiveness. Intramuscular fat (IMF) content is an important index affecting the eating quality of pork such as flavor, tenderness and juiciness. At present, increasing intramuscular fat content of pigs through genetic breeding and nutritional regulation has become a research hotspot in the field of animal production and meat science. Traditional breeding methods mainly rely on selection of phenotypic traits and assisted selection of genetic markers, but the breeding cycle is long, the cost is high, and it may have a negative impact on other production performance of pigs, making it difficult to achieve precise and controllable regulation of intramuscular fat.

[0003] In recent years, nutritional regulation has been gradually applied to the study of intramuscular fat deposition. Among them, fish oil rich in n-3 polyunsaturated fatty acids has been proven to play a regulatory role in animal fat metabolism. However, since the specific mechanism of how fish oil affects animal fat metabolism is still unclear, it is still impossible to achieve precise regulation of intramuscular fat content of pigs to improve pork quality. SUMMARY

[0004] The purpose of the present application is to avoid the shortcomings in the prior art and provide application of vascular endothelial growth factor B (VEGF-B) in increasing intramuscular fat content of pigs. It is found that the content of VEGF-B in pig serum and the expression level of VEGF-B 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 purposes, the present application provides the following technical solutions:

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

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

[0008] The application of VEGF-B as a biomarker in predicting intramuscular fat content of pigs has the following beneficial effects:

[0009] The application of VEGF-B as a biomarker in predicting intramuscular fat content in pigs revealed a significant positive correlation between the content of VEGF-B in pig serum and its expression level in skeletal muscle and the content of intramuscular fat in pig skeletal muscle tissue. This study can predict the intramuscular fat content in pigs and thus assess the intramuscular fat deposition potential, providing an important reference indicator for pig breeding and production.

[0010] To achieve the second objective mentioned above, the present invention provides the following technical solution:

[0011] This study provides the application of VEGF-B in increasing intramuscular fat content in pigs, by upregulating VEGF-B expression to promote skeletal muscle fat deposition and thus increase intramuscular fat content in pigs.

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

[0013] The beneficial effects of the application of VEGF-B in increasing intramuscular fat content in pigs according to this invention:

[0014] The application of VEGF-B in regulating and increasing intramuscular fat content in pigs revealed a positive correlation between the content of VEGF-B in pig serum and its expression level in skeletal muscle and 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 fatty acids across vascular endothelial cells to skeletal muscle cells, thus acting as a bridge in the formation of intramuscular fat. This provides a new target for precise regulation of intramuscular fat and a theoretical basis for the regulation of fat metabolism in pigs.

[0015] To achieve the third objective mentioned above, the present invention provides the following technical solution:

[0016] This study provides a nutritional regulation method to increase intramuscular fat content in pigs. The method involves administering n-3 polyunsaturated fatty acids to pigs to activate the GPR120 signaling pathway. The GPR120 signaling pathway upregulates the expression of VEGF-B, thereby increasing the intramuscular fat content in pigs.

[0017] In some implementations, pigs are fed fish oil containing n-3 polyunsaturated fatty acids, thereby administering n-3 polyunsaturated fatty acids to the pigs.

[0018] In some implementations, pigs are fed a diet containing fish oil with n-3 polyunsaturated fatty acids.

[0019] The beneficial effects of the nutritional regulation method for increasing intramuscular fat content in pigs according to this invention are as follows:

[0020] (1) The present invention provides a nutritional regulation method for increasing intramuscular fat content in pigs. It has been discovered that n-3 polyunsaturated fatty acids upregulate VEGF-B levels in pig serum or VEGF-B expression in skeletal muscle by activating the GPR120 signaling pathway, thereby promoting the transport of fatty acids across vascular endothelial cells to skeletal muscle cells and ultimately promoting fatty acid deposition in muscle cells. Therefore, by using n-3 polyunsaturated fatty acids for precise nutritional intervention, the intramuscular fat content in pigs can be increased. This method is applicable to multiple areas such as genetic improvement, healthy farming, and animal nutrition regulation, overcoming the problem of low intramuscular fat deposition efficiency in existing technologies.

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

[0022] It also provides a nutrient that increases intramuscular fat content in pigs, containing n-3 polyunsaturated fatty acids. Attached Figure Description

[0023] Figure 1 This is a graph showing the experimental comparison results of Experiment Example 1.

[0024] Figure 2 This is a graph showing the experimental comparison results of Experiment Example 2.

[0025] Figure 3 This is a comparison chart of the experimental results for Example 3. Detailed Implementation

[0026] Preferred embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0027] Example 1

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

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

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

[0031] Furthermore, by detecting the expression levels 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; in particular, 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 high.

[0032] In practice, by precisely detecting the expression level of VEGF-B in porcine skeletal muscle tissue or the content of VEGF-B in serum, the deposition potential of intramuscular fat in pigs can be assessed sensitively and accurately. This provides a reliable scientific basis for the genetic selection and precision feeding management of pigs, and helps to screen out pig breeds with higher intramuscular fat deposition potential, thereby improving pork quality from the source.

[0033] Example 2

[0034] This embodiment discloses the application of VEGF-B in increasing intramuscular fat content in pigs. It can upregulate the expression of VEGF-B, thereby promoting the transport of fatty acids across vascular endothelial cells to skeletal muscle cells, and ultimately increasing skeletal muscle fat deposition to increase intramuscular fat content in pigs.

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

[0036] The study found a significant positive correlation between the content of VEGF-B in porcine serum and its expression level in skeletal muscle and the content of intramuscular fat in porcine skeletal muscle tissue. VEGF-B can indirectly increase the deposition level of fatty acids in muscle tissue by promoting the transport of fatty acids across vascular endothelial cells to skeletal muscle cells. This makes VEGF-B play a bridging role in the formation of intramuscular fat, providing a new target for precise regulation of intramuscular fat and providing a theoretical basis for the regulation of fat metabolism in pigs.

[0037] Example 3

[0038] This embodiment discloses a nutritional regulation method for increasing intramuscular fat content in pigs. The method involves administering n-3 polyunsaturated fatty acids to pigs to activate the GPR120 signaling pathway, thereby increasing the intramuscular fat content in pigs.

[0039] Specifically, this involves adding fish oil rich in n-3 polyunsaturated fatty acids to pig feed. The fish oil induces myotube cells to secrete VEGF-B by activating the GPR120 signaling pathway. VEGF-B acts paracrinely 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 a nutritional regulation perspective, this invention utilizes the abundant n-3 polyunsaturated fatty acids in fish oil, particularly docosahexaenoic acid (DHA). n-3 polyunsaturated fatty acids, with their unique molecular structure and biological activity, specifically act on related cellular signaling pathways in vivo, namely the GPR120 signaling pathway, to upregulate VEGF-B expression. As VEGF-B expression levels increase, the fatty acid transport function of vascular endothelial cells is significantly activated, enabling more fatty acids to efficiently cross the vascular endothelial barrier and deposit in muscle tissue, achieving precise regulation of intramuscular fat in pigs. This invention provides new biomarkers and nutritional intervention strategies for improving pork quality.

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

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

[0043] In this embodiment, pigs are fed fish oil containing n-3 polyunsaturated fatty acids, thereby administering n-3 polyunsaturated fatty acids to the pigs.

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

[0045] Example 4

[0046] This embodiment discloses a nutrient agent that increases the intramuscular fat content of pigs. The nutrient agent contains n-3 polyunsaturated fatty acids, and applying the nutrient agent 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 in increasing intramuscular fat content in pigs, the following experiments were conducted:

[0049] Experimental Example 1

[0050] To verify the correlation between VEGF-B and intramuscular fat deposition, pig herds with significant differences in intramuscular fat content were selected, and the longissimus dorsi muscle was collected. The protein expression level of VEGF-B was detected by Western blotting, and the correlation with the intramuscular fat content in the tissue was analyzed. Figure 1 In the image, (A) shows the intramuscular fat content in the longissimus dorsi muscle of Guangdong Black Pig; (B) shows an image of Guangdong Black Pig muscle stained with Oil Red O; (C) shows the VEGF-B content in the serum of Guangdong Black Pig; (D) shows the TG (triglyceride) content in the serum of Guangdong Black Pig; (E) shows the correlation analysis between intramuscular fat content and serum VEGF-B content; and (FG) shows the differences and statistical graphs of VEGFs, their receptor signaling proteins, and GPR120 protein expression in the longissimus dorsi muscle of Guangdong Black Pig.

[0051] Depend on Figure 1 It was found that the VEGF-B protein expression level in the control group with low intramuscular fat content was lower than that in the experimental group with high intramuscular fat content (High-IMF). The VEGF-B level in porcine serum was significantly positively correlated with intramuscular fat content (IMF content), indicating that VEGF-B can be used as a biomarker to predict or assess intramuscular fat content in porcines.

[0052] Experiment Example 2

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

[0054] like Figure 2 As shown, (AB)DHA treatment significantly upregulated the expression level of GPR120 in myotube cells, while simultaneously inducing increased expression and secretion of VEGF-B (CF). Furthermore, in a co-culture system of myotube cells and vascular endothelial cells, DHA treatment significantly enhanced the fatty acid uptake and transmembrane transport capacity of vascular endothelial cells (GJ), effectively improving the supply of fatty acids from vascular endothelial cells to myotube cells (KL). These results indicate that DHA can upregulate VEGF-B expression in myotube cells by activating GPR120, thereby enhancing the uptake and transport of fatty acids by vascular endothelial cells through paracrine mechanisms, ultimately increasing fatty acid supply to muscle cells. This reveals the indirect mechanism by which DHA promotes lipid deposition in skeletal muscle.

[0055] Experimental Example 3

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

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

[0058] Depend on Figure 3 As can be seen, (AB) shows the Oil Red O staining and statistical graph of the tibialis anterior muscle in the control group and mice that have been administered fish oil for a long time, indicating that n-3 polyunsaturated fatty acids can effectively increase the amount of fat deposition in the skeletal muscle of mice; (C) shows the triglyceride content of the tibialis anterior muscle in the control group and mice that have been administered fish oil for a long time, indicating that n-3 polyunsaturated fatty acids can effectively increase the triglyceride content in mice; (D) shows the TG content in the serum of the control group and mice that have been administered fish oil for a long time, indicating that n-3 polyunsaturated fatty acids can effectively increase the TG content in mice; (E) shows the NEFA (non-esterified fatty acid) content in the serum of the control group and mice that have been administered fish oil for a long time, indicating that n-3 polyunsaturated fatty acids can effectively increase the non-esterified fatty acid content in mice; (F) shows the VEGF-B content in the serum of the control group and mice that have been administered fish oil for a long time, indicating that n-3 polyunsaturated fatty acids can effectively increase the VEGF-B content in mice; (GH) shows the difference and statistical graph of the expression of VEGF-B and its receptor signaling protein in the control group and mice that have been administered fish oil for a long time, indicating that n-3 polyunsaturated fatty acids can effectively increase the expression of VEGF-B and its receptor signaling protein 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 above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. The application of fish oil containing n-3 polyunsaturated fatty acids in the preparation of feed to increase intramuscular fat content in pigs, characterized in that, Administering fish oil containing n-3 polyunsaturated fatty acids to pigs activates the GPR120 signaling pathway, which upregulates VEGF-B expression, thereby increasing intramuscular fat content in pigs.

2. The application according to claim 1, characterized in that, Pigs are given fish oil containing n-3 polyunsaturated fatty acids, thus applying n-3 polyunsaturated fatty acids to them.

3. The application according to claim 1, characterized in that, Pigs are given n-3 polyunsaturated fatty acids by feeding them with fish oil containing n-3 polyunsaturated fatty acids.

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