ABSTRACT
After implantation of a biomaterial, both the host immune system and properties of the material determine the local immune response. Through triggering or modulating the local immune response, materials can be designed towards a desired direction of promoting tissue repair or regeneration. High-throughput sequencing technologies such as single-cell RNA sequencing (scRNA-seq) emerging as a powerful tool for dissecting the immune micro-environment around biomaterials, have not been fully utilized in the field of soft tissue regeneration. In this review, we first discussed the procedures of foreign body reaction in brief. Then, we summarized the influences that physical and chemical modulation of biomaterials have on cell behaviors in the micro-environment. Finally, we discussed the application of scRNA-seq in probing the scaffold immune micro-environment and provided some reference to designing immunomodulatory biomaterials. The foreign body response consists of a series of biological reactions. Immunomodulatory materials regulate immune cell activation and polarization, mediate divergent local immune micro-environments and possess different tissue engineering functions. The manipulation of physical and chemical properties of scaffolds can modulate local immune responses, resulting in different outcomes of fibrosis or tissue regeneration. With the advancement of technology, emerging techniques such as scRNA-seq provide an unprecedented understanding of immune cell heterogeneity and plasticity in a scaffold-induced immune micro-environment at high resolution. The in-depth understanding of the interaction between scaffolds and the host immune system helps to provide clues for the design of biomaterials to optimize regeneration and promote a pro-regenerative local immune micro-environment.
ABSTRACT
Objective To investigate the distribution of folliclestimulating hormone (FSH),luteinizing hormone (LH) and colocalization with gonadotropin releasing hormone receptor (GnRHR) in rat submaxilary glands. Methods Distribution of FSH, LH and colocalization with GnRHR consecutive sections of rat submaxilary glands were investigated by immunohistochemical colocalization methods. Results FSH and LH immunoreactivity were observed in the epithelial cells of serous acinus, secretory tubes, excretory ducts and granular convoluted tubule. The immunoreactive materials were brown and distributed in the cytoplasma with negative nucleolus. The results of immunohistochemical colocalization showed not only FSH but also GnRHR immunoreactivity in the same structure of two adjacent section. The distribution of the positive substance of FSH and GnRHR were similar to each other. The most of showing GnRHR immunoreactivity cells were detected LH immunoreactivity in the same structure of two adjacene section and the others were immunonegative. The GnRNR immunoreactive materials were distributed in the cytoplasma with negative nucleolus.Conclusion The epithelial cell of serous acinus, secretory tubes, excretory ducts and granular convoluted tubule of rat submaxilary glands may be synthesized and secreted FSH and LH. These cells with FSH and LH positive immunoreaction of rat submaxilary glands may be regulated by Gonadotropin releasing hormone (GnRH) through autocrine or paracrine.;