Preface

　　Zinc is an essential trace mineral, and many enzymes in different biological systems depend on it for survival. Among these zinc-dependent enzymes, DNA and RNA polymerases play a vital role in tissue repair because they affect cell proliferation and protein synthesis. Studies have shown that a lack of zinc in the body can delay the healing process of injured skin and connective tissue in pigs and gastric ulcers in mice.

　　Timely supplement of zinc and polyprezinc (a chelate composed of zinc ions and L-carnosine) can promote the repair of injured skin, accelerate the healing of gastric ulcers, and prevent various experimental gastric injuries. Growth factors play an important role in the healing of gastric ulcers. Insulin-like growth factor (IGF) is a polypeptide similar in structure to proinsulin. IGF-I can promote growth in various organs including the stomach. IGF-II is mainly used in Stimulate growth before delivery. IGF-I receptors were detected in the gastrointestinal tract of rats. Therefore, IGF-I may be involved in the healing and growth process of the gastrointestinal tract. So does Polyprezinc (Polaprezinc, PZ) induce growth factor (IGF-I) changes during the process of accelerating the healing of gastric ulcers? Please see the following research.

　　Materials and Method

　　1.1 Cell culture

　　Human foreskin fibroblasts were cultured in 106 medium for 3 days for the preparation of conditioned medium and molecular biology experiments. Fibroblasts were cultured in zinc- and serum-free MEM for 24 hours, and polyprezinc (10-4M) was added to the culture medium for 8 hours as a conditioned medium. After mixing the conditioned medium with anti-human IGF-I antibody (diluted 200×) at room temperature for 1 hour, it was used to culture gastric epithelial cells.

　　1.2 Gastric epithelial cell repair

　　IGF-I was diluted with culture medium to 1, 10 and 50μg/mL. 48 hours after cell injection, gastric epithelial cells formed a monolayer of cell membrane. A pencil mixer with a rotating silicon tip (diameter 1mm) was used to form 2mm² in the center of the cell membrane. Round artificial trauma. The entire repair experiment was carried out in serum-free medium, including cell migration and proliferation experiments. Use an inverted phase contrast microscope and a laser disc recording system to monitor the epithelial repair process. An image analyzer was used to quantitatively analyze the changes in cell free area during the repair process.

　　1.3 Cell migration

　　In addition to observing the changes in the cell free zone during the repair process, it also observes the cell migration speed at the edge of the wound after injury. Use the above-mentioned equipment to monitor the traces of cell migration 1h to 4h after injury. The speed of cell migration has nothing to do with cell proliferation. The migration speed of the control group, IGF-I group (50μg/mL), fibroblast conditioned medium group, neutral conditioned medium group and polyprezinc group (10-4M) were expressed in μ/h. 1.4 Cell proliferation

　　Use BrdU indirect immunohistochemistry to detect DNA synthesis in gastric epithelial cells. Calculate the BrdU labeling index around the wound.

　　1.5 IGF-I gene expression

　　Cells were cultured for 24 hours, polyprezinc (10-4M) and zinc sulfate were added to the medium, the cells were incubated for 6 hours, and the total RNA of the cells was extracted with AGPC. The content of IGF-I mRNA was detected by rTth-DNA polymerase and Southern hybridization one-step PCR method, and total RNA was amplified. The ECL detection kit of horseradish peroxidase labeled with anti-FI antibody detects the signal on the X-ray film, and the X-ray film is analyzed with the image analyzer V10.

　　Results and analysis

　　2.1 Gastric epithelial cell repair rate

　　The repair of gastric epithelial cells in the control group took 48h, while in cultures containing IGF-I (10 and 50μg/mL), the repair of gastric epithelial cells was faster. Table 1 Cell free area size during gastric epithelial cell repair (mm²)

　　In the conditioned medium, the repair speed of gastric epithelial cells is also faster. However, compared with the control group, the repair speed of gastric epithelial cells did not change significantly in the neutral medium containing anti-IGF-I antibody and the culture containing polyprezinc.

　　2.2 Cell migration

　　The migration rate of gastric epithelial cells at the margin of the wound was 20.1μ/h, and 50μg/mL IGF-I accelerated their migration rate (36.8μ/h, P<0.01). The addition of fibroblasts significantly accelerated the cell migration rate (32.2μ/h, P<0.01). However, neutral medium and medium containing polyprezinc did not significantly increase the migration speed of gastric epithelial cells.

　　2.3 Cell proliferation

　　In the first 24 hours after trauma, the proliferation of gastric epithelial cells in the control group during the repair process was negligible, reaching a peak at 36 hours (BrdU labeling index, 3.3%), and returning to the baseline level when completely repaired. BrdU-positive cells appeared earlier in the medium containing IGF-I (labeling index 6.0%) and fibroblasts (labeling index 5.4%) (24h group), and reached the peak. In the medium containing neutral medium and polyprezinc, cell proliferation was similar to that of the control group.

　　2.4 Expression of IGF-I gene in fibroblasts

　　To study the effects of IGF-I, transforming growth factor β1 (TGF-β1) and hepatocyte growth factor (HGF) in human foreskin fibroblasts in the presence or absence of zinc ions, polyprezinc and IGF-I Express the situation. Before polyprezinc pretreatment, the expression of IGF-I, TGF-β1 and HGF genes in human foreskin fibroblasts was extremely weak. When polyprezinc was added to the medium, the expression of IGF-I gene was significantly up-regulated and showed a dose Dependent, IGF-I mRNA expression was the highest at 3×10-8M, but polyprezinc did not affect the gene expression of TGF-β1 and HGF.

　　Discuss

　　This article uses an in vitro wound repair model that interacts with gastric epithelial cells and fibroblasts to analyze the effect of IGF-I on the migration and proliferation of gastric epithelial cells.

　　"The results show that IGF-I not only promotes cell migration and proliferation, but also significantly promotes the repair of epithelial cells in vitro. Polyprezinc significantly up-regulates the expression of IGF-I mRNA; when IGF-I is added, it promotes gastric epithelial cell repair, but when anti-IGF-I antibody is added, this promotion is completely eliminated. Suffice it to say that polyprezinc induces fibroblasts to produce IGF-I and promotes gastric epithelial cell repair through paracrine pathways.

　　Boda Weiye Ruilaisheng (Polyprezinc Granules) is a mucosal protective agent with a unique mechanism of action. It promotes the proliferation of gastric epithelial cells by up-regulating the expression of IGF-I mRNA, thereby effectively repairing gastric ulcers and accelerating the healing of gastric ulcers .