The effect of FMT and vitamin C on immunity-related genes in antibiotic-induced dysbiosis in mice.

Antibiotics are double-edged swords. Although antibiotics are used to inhibit pathogenic bacteria, they also run the risk of destroying some of the healthy bacteria in our bodies. We examined the effect of penicillin on the organism through a microarray dataset, after which 12 genes related to immuno-inflammatory pathways were selected by reading the literature and validated using neomycin and ampicillin. The expression of genes was measured using qRT-PCR. Several genes were significantly overexpressed in antibiotic-treated mice, including CD74 and SAA2 in intestinal tissues that remained extremely expressed after natural recovery. Moreover, transplantation of fecal microbiota from healthy mice to antibiotic-treated mice was made, where GZMB, CD3G, H2-AA, PSMB9, CD74, and SAA1 were greatly expressed; however, SAA2 was downregulated and normal expression was restored, and in liver tissue, SAA1, SAA2, SAA3 were extremely expressed. After the addition of vitamin C, which has positive effects in several aspects, to the fecal microbiota transplantation, in the intestinal tissues, the genes that were highly expressed after the fecal microbiota transplantation effectively reduced their expression, and the unaffected genes remained normally expressed, but the CD74 gene remained highly expressed. In liver tissues, normally expressed genes were not affected, but the expression of SAA1 was reduced and the expression of SAA3 was increased. In other words, fecal microbiota transplantation did not necessarily bring about a positive effect of gene expression restoration, but the addition of vitamin C effectively reduced the effects of fecal microbiota transplantation and regulated the balance of the immune system.

Changes in the Scleral Collagen and Elastic Modulus in Experimental High Myopia / 医用生物力学

Objective To investigate changes in the collagen expression and elastic modulus in scleral tissues of experimental high myopia, so as to further explain the mechanism of high myopia. Methods Twenty one-month-old New Zealand white rabbits were monocularly treated by eyelid suturation randomly to build an experimental high myopia eye model. Eyes without such operation were set as the normal control. After 60 days, the experimental high myopia eye models were successfully established by measuring the eye axis. The eyeballs were obtained to assess three regions of the sclera (anterior, equatorial, and posterior area). The three regions of the scleral tissues were separately divided into four groups. The first group was made into scleral strips for elastic modulus measurement using an Instron5544. The second group was hematoxylin-and-eosin stained for observation of the scleral structures. The third group was used for electron microscopy to observe the size distribution of collagen fibrils. The last group was homogenized, and the concentration of hydroxyproline was measured to determine the collagen content. Results The elastic modulus, collagen content, and diameters of the collagen fibrils of each scleral region increased with age. The posterior sclera of high myopia had looser collagen fibril arrangement, less hydroxyproline concentration, and lower elastic modulus than the normal eyes. However, there was no significant difference as for the anterior and equatorial sclera. Conclusions The remodeled posterior sclera of high myopia has a looser collagen fibril arrangement, less collagen, and lower elastic modulus, which easily causes expansion and deformation and thus lead to high myopia. The research findings provide the theoretical guidance for high myopia prevention by targeting the collagen during early development.