Intratympanic Insulin-like Growth Factor-1 Administration Via the Otic Bulla in a Severe Facial Paralysis Model

Identification of critical mitochondrial hub gene for facial nerve regeneration

Mitochondria play a critical role in nerve regeneration, yet the impact of gene expression changes related to mitochondria in facial nerve regeneration remains unknown. To address this knowledge gap, we analyzed the expression profile of the facial motor nucleus (FMN) using data obtained from the Gene Expression Omnibus (GEO) database (GSE162977). By comparing different time points in the data, we identified differentially expressed genes (DEGs). Additionally, we collected mitochondria-related genes from the Gene Ontology (GO) database and intersected them with the DEGs, resulting in the identification of mitochondria-related DEGs (MIT-DEGs). To gain further insights, we performed functional enrichment and pathway analysis of the MIT-DEGs. To explore the interactions among these MIT-DEGs, we constructed a protein-protein interaction (PPI) network using the STRING database and identified hub genes using the Degree algorithm of Cytoscape software. To validate the relevance of these genes to nerve regeneration, we established a rat facial nerve injury (FNI) model and conducted a series of experiments. Through these experiments, we confirmed three MIT-DEGs (Myc, Lyn, and Cdk1) associated with facial nerve regeneration. Our findings provide valuable insights into the transcriptional changes of mitochondria-related genes in the FMN following FNI, which can contribute to the development of new treatment strategies for FNI.

The Adverse Effects Profile of Teprotumumab

CONTEXT

Teprotumumab therapy for thyroid eye disease (TED) patients represents a major step forward. It targets and inhibits the insulin-like growth factor-1 receptor (IGF-1R), and its effectiveness is based on its interconnectedness with the thyrotropin receptor. However, IGF-1R has a ubiquitous expression and several adverse effects have been reported with teprotumumab use.

OBJECTIVE

Describing these adverse effects for better understanding is the purpose of this review.

METHODS

We reviewed the oncological studies in which teprotumumab was initially used. Subsequently we reviewed the clinical trials for TED and then the case series and case reports associated with teprotumumab use since it is US Food and Drug Administration approval (January 2020). We focused on common and/or serious adverse effects reported with the use of teprotumumab.

RESULTS

We described the common occurrence of hyperglycemia (10%-30% incidence), its risk factors and suggested management. Hearing changes are described, a broad spectrum from mild ear pressure to hearing loss (sensorineural mechanism). Risk factors, suggested monitoring, and possible upcoming therapies are reviewed. We also reviewed data on fatigue, muscle spasms, hair loss, weight loss, gastrointestinal disturbances, menstrual changes, and infusion reactions. We noted some discrepancies between adverse effects in oncological studies vs studies focused on TED, and we aimed to explain these differences.

CONCLUSION

The use of teprotumumab should consider patient's values and preferences in balancing the expected benefit with these potential risks. Future drugs targeting IGF-1R should investigate these adverse effects for a possible class effect. Combination therapies with different agents hopefully will be identified that maximize benefits and minimize risks.