The effect of teprotumumab infusion on ocular alignment in patients with symptomatic thyroid eye disease.

BACKGROUND: Thyroid eye disease (TED) can result in proptosis and ocular misalignment, leading to eye pain, diplopia, and vision loss. Teprotumumab, a humanized antibody against insulin-like growth factor 1 receptor, was approved in 2020 for the treatment of TED. The purpose of this study was to describe the effect of a full course of teprotumumab on ocular misalignment. METHODS: The medical records of patients who underwent treatment with teprotumumab for active moderate-to-severe TED at a single institution from April 2020 to September 2023 were reviewed retroactively. Sensorimotor examination was performed at each visit using simultaneous prism-cover testing. Demographic information and previous history of radioactive iodine, steroids, strabismus surgery, and smoking were extracted from the record for analysis. RESULTS: A total of 19 patients were treated during the study period, of whom 11 had strabismus and diplopia. The initial absolute horizontal misalignment in these 11 was 6.0Δ ± 1.5Δ, vertical misalignment was 7.7Δ ± 2.4Δ, and total misalignment was 11.5Δ ± 2.0Δ. On completion of treatment, these measurements decreased by 2.0Δ ± 1.5Δ, 2.2Δ ± 1.0Δ, and 3.2Δ ± 1.6Δ, respectively (P = 0.10, 0.02, and 0.04, resp.). Eight patients (73%) had a decrease in their strabismus, and 5 (46%) reported complete resolution of their diplopia at the final visit. No factors were predictive of which patients would have resolution of their misalignment. Of the remaining 3 patients who had no improvement in ocular alignment, 2 (66%) underwent strabismus surgery. Of the 8 patients with improvement of strabismus, only a single patient (13%) underwent strabismus surgery for persistent diplopia. CONCLUSIONS: In our study cohort, a full course of teprotumumab coincided with complete resolution of diplopia in 46% of patients and a decrease in strabismus in 73% of patients.

Evidence for Systemic Reactive Oxygen Species in UVB-mediated Microvesicle Formation.

Recent studies have implicated subcellular microvesicle particles (MVP) in the ability of ultraviolet B radiation to exert both local and systemic effects. Indeed, UVB generates MVP (UVB-MVP) in human skin and systemically following phototherapy. The current studies were designed to test the hypothesis that the ability of UVB to generate MVP was dependent upon reactive oxygen species (ROS). To that end, we tested urine samples from subjects undergoing UVB phototherapy for the presence of isoprostanes as well as the oxidized guanosine derivative 8OHdG. We also conducted a clinical study in which volar forearms of subjects were treated with localized UVB and erythema/MVP measured. The same cohort was then treated with 7 days of vitamin C (2 g day-1 ) and vitamin E (1000 IU day-1 ), and UVB-induced MVPs tested on the contralateral forearm. Urine specimens from subjects undergoing phototherapy were found to have increased levels of isoprostanes and 8OHdG, with maximal levels noted 8-16 h post-treatment. Treatment with antioxidant vitamins resulted in diminished UVB-generated skin MVP to baseline levels. These studies suggest that whole-body UVB generates a systemic pro-oxidative response, and that antioxidants can attenuate localized skin UVB-MVPs.

Keratinocyte-derived microvesicle particles mediate ultraviolet B radiation-induced systemic immunosuppression.

A complete carcinogen, ultraviolet B (UVB) radiation (290-320 nm), is the major cause of skin cancer. UVB-induced systemic immunosuppression that contributes to photocarcinogenesis is due to the glycerophosphocholine-derived lipid mediator platelet-activating factor (PAF). A major question in photobiology is how UVB radiation, which only absorbs appreciably in the epidermal layers of skin, can generate systemic effects. UVB exposure and PAF receptor (PAFR) activation in keratinocytes induce the release of large numbers of microvesicle particles (MVPs; extracellular vesicles ranging from 100 to 1000 nm in size). MVPs released from skin keratinocytes in vitro in response to UVB (UVB-MVPs) are dependent on the keratinocyte PAFR. Here, we used both pharmacologic and genetic approaches in cells and mice to show that both the PAFR and enzyme acid sphingomyelinase (aSMase) were necessary for UVB-MVP generation. Our discovery that the calcium-sensing receptor is a keratinocyte-selective MVP marker allowed us to determine that UVB-MVPs leaving the keratinocyte can be found systemically in mice and humans following UVB exposure. Moreover, we found that UVB-MVPs contained bioactive contents including PAFR agonists that allowed them to serve as effectors for UVB downstream effects, in particular UVB-mediated systemic immunosuppression.

1H, 15N and 13C resonance assignments for free and IEEVD peptide-bound forms of the tetratricopeptide repeat domain from the human E3 ubiquitin ligase CHIP.

The ubiquitin ligase CHIP catalyzes covalent attachment of ubiquitin to unfolded proteins chaperoned by the heat shock proteins Hsp70/Hsc70 and Hsp90. CHIP interacts with Hsp70/Hsc70 and Hsp90 by binding of a C-terminal IEEVD motif found in Hsp70/Hsc70 and Hsp90 to the tetratricopeptide repeat (TPR) domain of CHIP. Although recruitment of heat shock proteins to CHIP via interaction with the CHIP-TPR domain is well established, alterations in structure and dynamics of CHIP upon binding are not well understood. In particular, the absence of a structure for CHIP-TPR in the free form presents a significant limitation upon studies seeking to rationally design inhibitors that may disrupt interactions between CHIP and heat shock proteins. Here we report the 1H, 13C, and 15N backbone and side chain chemical shift assignments for CHIP-TPR in the free form, and backbone chemical shift assignments for CHIP-TPR in the IEEVD-bound form. The NMR resonance assignments will enable further studies examining the roles of dynamics and structure in regulating interactions between CHIP and the heat shock proteins Hsp70/Hsc70 and Hsp90.

Investigating the Impact of Polymer Functional Groups on the Stability and Activity of Lysozyme-Polymer Conjugates.

Polymers are often conjugated to proteins to improve stability; however, the impact of polymer chain length and functional groups on protein structure and function is not well understood. Here we use RAFT polymerization to grow polymers of different lengths and functionality from a short acrylamide oligomer with a RAFT end group conjugated to lysozyme. We show by X-ray crystallography that enzyme structure is minimally impacted by modification with the RAFT end group. Significant activity toward the negatively charged Micrococcus lysodeicticus cell wall was maintained when lysozyme was modified with cationic polymers. Thermal and chemical stability of the conjugates was characterized using differential scanning fluorimetry and tryptophan fluorescence. All conjugates had a lower melting temperature; however, conjugates containing ionic or substrate mimicking polymers were more resistant to denaturation by guanidine hydrochloride. Our results demonstrate that tailoring polymer functionality can improve conjugate activity and minimize enzymatic inactivation by denaturants.

A bipartite interaction between Hsp70 and CHIP regulates ubiquitination of chaperoned client proteins.

The ubiquitin ligase CHIP plays an important role in cytosolic protein quality control by ubiquitinating proteins chaperoned by Hsp70/Hsc70 and Hsp90, thereby targeting such substrate proteins for degradation. We present a 2.91 Å resolution structure of the tetratricopeptide repeat (TPR) domain of CHIP in complex with the α-helical lid subdomain and unstructured tail of Hsc70. Surprisingly, the CHIP-TPR interacts with determinants within both the Hsc70-lid subdomain and the C-terminal PTIEEVD motif of the tail, exhibiting an atypical mode of interaction between chaperones and TPR domains. We demonstrate that the interaction between CHIP and the Hsc70-lid subdomain is required for proper ubiquitination of Hsp70/Hsc70 or Hsp70/Hsc70-bound substrate proteins. Posttranslational modifications of the Hsc70 lid and tail disrupt key contacts with the CHIP-TPR and may regulate CHIP-mediated ubiquitination. Our study shows how CHIP docks onto Hsp70/Hsc70 and defines a bipartite mode of interaction between TPR domains and their binding partners.

The best of both worlds: active enzymes by grafting-to followed by grafting-from a protein.

Hydrophilic polymers were attached to lysozyme by a combination of grafting-to and grafting-from approaches using RAFT polymerization. A hydrophilic oligomer was synthesized, and attached to the protein. The protein-oligomer hybrid contained the RAFT end group, enabling chain extension in solution. Lysozyme maintained activity throughout this process.