Nasal Septum Deviation as the Consequence of BMP-Controlled Changes to Cartilage Properties

Role of Growth Factors in Nasal Cartilage Development and Molding: A Comprehensive Review

This review aims to investigate the properties of growth factors concerning the morphogenesis and development of nasal cartilage, which is fundamentally important for facial form and appearance. Since cartilage lacks a blood supply, it is more difficult to regenerate, as cartilage tissue obtains sustenance by diffusion. Cytokines are signalling molecules that control chondrocyte metabolism and extracellular matrix formation, which is required for cartilage development, homeostasis, and healing. Some craniofacial illnesses alter the composition of the cartilage and the structural organization of growth factors, allowing for moulding. TGF-β (transforming growth factor-β) encourages chondrocyte differentiation, whereas IGF-1 (insulin-like growth factor-1) stimulates cartilage-forming collagen synthesis and chondrocyte multiplication. We used the scoping review approach to present current research on the role of growth factors in the creation and architecture of nasal cartilage. We generally observed this structure before conducting specific experiments to determine the impact of growth agents on the development of chondrocytes and cartilage. Prominent findings increase our understanding of how growth factors influence the extracellular matrix, cell activities and features, and cartilage growth rate; all are critical for cartilage tissue development and repair. Research into growth factors and their physiological interactions with cartilage may help improve treatment's functional and aesthetic outcomes and our understanding of the origins and consequences of nasal congenital anomalies. This study emphasizes the importance of expanding knowledge and experience, as well as the use of growth factors in clinical practice, to stimulate cartilage development.

An overview of nasal cartilage bioprinting: from bench to bedside

Nasal cartilage diseases and injuries are known as significant challenges in reconstructive medicine, affecting a substantial number of individuals worldwide. In recent years, the advent of three-dimensional (3D) bioprinting has emerged as a promising approach for nasal cartilage reconstruction, offering potential breakthroughs in the field of regenerative medicine. This paper provides an overview of the methods and challenges associated with 3D bioprinting technologies in the procedure of reconstructing nasal cartilage tissue. The process of 3D bioprinting entails generating a digital 3D model using biomedical imaging techniques and computer-aided design to integrate both internal and external scaffold features. Then, bioinks which consist of biomaterials, cell types, and bioactive chemicals, are applied to facilitate the precise layer-by-layer bioprinting of tissue-engineered scaffolds. After undergoing in vitro and in vivo experiments, this process results in the development of the physiologically functional integrity of the tissue. The advantages of 3D bioprinting encompass the ability to customize scaffold design, enabling the precise incorporation of pore shape, size, and porosity, as well as the utilization of patient-specific cells to enhance compatibility. However, various challenges should be considered, including the optimization of biomaterials, ensuring adequate cell viability and differentiation, achieving seamless integration with the host tissue, and navigating regulatory attention. Although numerous studies have demonstrated the potential of 3D bioprinting in the rebuilding of such soft tissues, this paper covers various aspects of the bioprinted tissues to provide insights for the future development of repair techniques appropriate for clinical use.

A BMP-controlled metabolic/epigenetic signaling cascade directs midfacial morphogenesis

Craniofacial anomalies, especially midline facial defects, are among the most common birth defects in patients and are associated with increased mortality or require lifelong treatment. During mammalian embryogenesis, specific instructions arising at genetic, signaling, and metabolic levels are important for stem cell behaviors and fate determination, but how these functionally relevant mechanisms are coordinated to regulate craniofacial morphogenesis remain unknown. Here, we report that bone morphogenetic protein (BMP) signaling in cranial neural crest cells (CNCCs) is critical for glycolytic lactate production and subsequent epigenetic histone lactylation, thereby dictating craniofacial morphogenesis. Elevated BMP signaling in CNCCs through constitutively activated ACVR1 (ca-ACVR1) suppressed glycolytic activity and blocked lactate production via a p53-dependent process that resulted in severe midline facial defects. By modulating epigenetic remodeling, BMP signaling-dependent lactate generation drove histone lactylation levels to alter essential genes of Pdgfra, thus regulating CNCC behavior in vitro as well as in vivo. These findings define an axis wherein BMP signaling controls a metabolic/epigenetic cascade to direct craniofacial morphogenesis, thus providing a conceptual framework for understanding the interaction between genetic and metabolic cues operative during embryonic development. These findings indicate potential preventive strategies of congenital craniofacial birth defects via modulating metabolic-driven histone lactylation.

Craniofacial anomalies in a murine model of heterozygous fibroblast growth factor 10 gene mutation

OBJECTIVE

Dysregulation of Fibroblast Growth Factor 10 (FGF10), a member of the family of Fibroblast Growth Factor (FGF) proteins, has been implicated in craniofacial and dental anomalies, including craniosynostosis, cleft palate, and Lacrimo-Auriculo-Dento-Digital Syndrome. The aim of this murine study was to assess the craniofacial and dental phenotypes associated with a heterozygous FGF10 gene (FGF10+/- ) mutation at skeletal maturity.

METHODS

Skulls of 40 skeletally mature mice, comprising two genotypes (heterozygous FGF10+/- mutation, n = 22; wildtype, n = 18) and two sexes (male, n = 23; female, n = 17), were subjected to micro-computed tomography. Landmark-based linear dimensions were measured for the cranial vault, maxilla, mandible, and first molar teeth. Multivariate analysis of variance was performed to assess whether there were significant differences in the craniofacial and dental structures between genotypes and sexes.

RESULTS

The craniomaxillary skeleton and the first molar teeth were smaller in the FGF10+/- mice (P < .05), but the mandible was unaffected. Sex did not have a significant effect on these structures (P > .05). Cranial sutural defects were noted in 5/22 (22.7%) mutant versus 2/18 (11.1%) wildtype mice, and cleft palate in only one (4.5%) mutant mouse. None of the mice displayed craniosynostosis, expansive bony lesions, bifid condyles, or impacted teeth.

CONCLUSION

The FGF10+/- mutation was associated with craniomaxillary skeletal hypoplasia that probably arose from deficient (delayed) intramembranous ossification of the sutured bones. Overall, the skeletal and dental data suggest that the FGF10 gene plays an important role in the aetiology of craniofacial dysmorphology and malocclusion.

Optogenetic manipulation of BMP signaling to drive chondrogenic differentiation of hPSCs

Optogenetics is a rapidly advancing technology combining photochemical, optical, and synthetic biology to control cellular behavior. Together, sensitive light-responsive optogenetic tools and human pluripotent stem cell differentiation models have the potential to fine-tune differentiation and unpick the processes by which cell specification and tissue patterning are controlled by morphogens. We used an optogenetic bone morphogenetic protein (BMP) signaling system (optoBMP) to drive chondrogenic differentiation of human embryonic stem cells (hESCs). We engineered light-sensitive hESCs through CRISPR-Cas9-mediated integration of the optoBMP system into the AAVS1 locus. The activation of optoBMP with blue light, in lieu of BMP growth factors, resulted in the activation of BMP signaling mechanisms and upregulation of a chondrogenic phenotype, with significant transcriptional differences compared to cells in the dark. Furthermore, cells differentiated with light could form chondrogenic pellets consisting of a hyaline-like cartilaginous matrix. Our findings indicate the applicability of optogenetics for understanding human development and tissue engineering.

A TGF-loading hydrogel scaffold capable of promoting chondrogenic differentiation for repairing rabbit nasal septum cartilage defect

Hydrogel-based tissue engineering has been widely used to repair cartilage injury. However, whether this approach can be applied to treat nasal septum cartilage defects remains unclear. In this study, three gelatin methacrylate-based scaffolds loaded with transforming growth factor (TGF)-β1 (GelMA-T) were prepared, and their effects on repair of nasal septum cartilage defects were examined. In vitro, the GelMA-T scaffolds showed good biocompatibility and promoted the chondrogenic differentiation of bone mesenchymal stem cells. Among three scaffolds, the 10% GelMA-T scaffold promoted chondrogenic differentiation most effectively, which significantly improved the expression of chondrocyte-related genes, including Col II, Sox9, and ACAN. In vivo, 10% GelMA-T scaffolds and 10% GelMA-T scaffolds loaded with bone mesenchymal stem cells (BMSCs; 10% GelMA-T/BMSCs) were transplanted into a nasal septum cartilage defect site in a rabbit model. At 4, 12, and 24 weeks after surgery, the nasal septum cartilage defects exhibited more complete repair in rabbits treated with the 10% GelMA-T/BMSC scaffold as demonstrated by hematoxylin & eosin, safranine-O, and toluidine blue staining. We showed that GelMA-T/BMSCs can be applied in physiological and structural repair of defects in nasal septum cartilage, providing a potential strategy for repairing cartilage defects in the clinic.

[Measurement of nasal septum area in 128 Chinese patients with nasal septum deviation]

Objective:Establish the anatomical parameters of the nasal septum and the area of each component in patients with nasal septum deviation, for the sake of guiding the scope of surgical resection for correction of nasal septum deviation. Methods:This is a retrospective study of 128 cases of sinus computer tomography images of patients with nasal septum deviation, marked 9 nasal septal anatomical locations, measured the area of the nasal septum and its components, and analyzed the trend of the percentage of the area of the nasal septum cartilage in the total area of the nasal septum with age. Results:The total area of the nasal septum in the 128 patients with nasal septum deviation is: （2951.96±305.91） mm², the area of nasal septal cartilage: （961.89±229.64） mm², the area of the vertical ethmoid plate: （1123.96±214.17） mm², the area of the vomerine: （652.77±108.09） mm². The area of male septum is larger than that of female. As age increases, the nasal septal cartilage gradually decreases, and the percentage of the nasal septal cartilage area in the total area of the nasal septum gradually decreases. Conclusion:Elderly people who undergo nasal septum correction should be carefully considered to grasp the scope of resection, and the influence of gender on the area of nasal septum should also be paid attention.

Properties of the Nasal Cartilage, from Development to Adulthood: A Scoping Review

OBJECTIVE

Nasal septum cartilage is a hyaline cartilage that provides structural support to the nasal cavity and midface. Currently, information on its cellular and mechanical properties is widely dispersed and has often been inferred from studies conducted on other cartilage types such as the knee. A detailed understanding of nasal cartilage properties is important for several biological, clinical, and engineering disciplines. The objectives of this scoping review are to (1) consolidate actual existing knowledge on nasal cartilage properties and (2) identify gaps of knowledge and research questions requiring future investigations.

DESIGN

This scoping review incorporated articles identified using PROSPERO, Cochrane Library (CDSR and Central), WOS BIOSIS, WOS Core Collection, and ProQuest Dissertations and Theses Global databases. Following the screening process, 86 articles were considered. Articles were categorized into three groups: growth, extracellular matrix, and mechanical properties.

RESULTS

Most articles investigated growth properties followed by extracellular matrix and mechanical properties. NSC cartilage is not uniform. Nasal cartilage growth varies with age and location. Similarly, extracellular matrix composition and mechanical properties are location-specific within the NSC. Moreover, most articles included in the review investigate these properties in isolation and only very few articles demonstrate the interrelationship between multiple cartilage properties.

CONCLUSIONS

This scoping review presents a first comprehensive description of research on NSC properties with a focus on NSC growth, extracellular matrix and mechanical properties. It additionally identifies the needs (1) to understand how these various cartilage properties intersect and (2) for more granular, standardized assessment protocols to describe NSC.