Antiproliferative activity of a liposomal delivery system of mitoxantrone on rabbit subconjunctival fibroblasts in an ex-vivo model

Integrating Differential Gene Expression Analysis with Perturbagen-Response Signatures May Identify Novel Therapies for Thyroid-Associated Orbitopathy

Purpose

To evaluate the efficacy of Library of Integrated Network-based Cellular Signatures (LINCS) perturbagen prediction software to identify small molecules that revert pathologic gene signature and alter disease phenotype in orbital adipose stem cells (OASCs) derived from patients with thyroid-associated orbitopathy (TAO).

Methods

Differentially expressed genes identified via RNA sequencing were inputted into LINCS L1000 Characteristic Direction Signature Search Engine (L1000CDS²) to predict candidate small molecules to reverse pathologic gene expression. TAO OASC cell lines were treated in vitro with six identified small molecules (Torin-2, PX12, withaferin A, isoliquiritigenin, mitoxantrone, and MLN8054), and expression of key adipogenic and differentially expressed genes was measured with quantitative polymerase chain reaction after 7 days of treatment. OASCs were differentiated into adipocytes, treated for 15 days, and stained with Oil Red O (OD 490 nm) to evaluate adipogenic changes.

Results

The expression of key differentially expressed genes (IRX1, HOXB2, S100B, and KCNA4) and adipogenic genes (peroxisome proliferator activated receptor-γ, FABP4) was significantly decreased in TAO OASCs after treatment (P < .05). In treated TAO adipocytes (n = 3), all six tested small molecules yielded significant decrease (P < .05) in Oil Red O staining. In treated non-TAO adipocytes (n = 3), only three of the drugs yielded a significant decrease in Oil Red O staining.

Conclusions

Combining disease expression signatures with LINCS small molecule prediction software can identify promising preclinical drug candidates for TAO.

Translational Relevance

These findings may offer insight into future potential therapeutic options for TAO and demonstrate a streamlined model to predict drug candidates for other diseases.

Preliminary investigation of mitoxantrone coating on stent-grafts to inhibit neointimal proliferation

PURPOSE

To investigate the inhibition of neointimal proliferation induced by a stent-graft loaded with mitoxantrone.

METHODS

Stent-grafts with and without mitoxantrone loading (150 microg per device) were inserted into the carotid artery of 7 and 6 rabbits, respectively. After an observation period of 28 days, the animals were sacrificed, and a detailed morphological and morphometric workup of the stented vessels was performed.

RESULTS

Uncoated stent-grafts induced a thick neointima (median diameter 97+/-99 microm), whereas no neointima formed in mitoxantrone-loaded stent-grafts. However, the loaded devices were not fully covered by an endothelial layer. The underlying media was significantly thinner (31.8+/-5.6 versus 48.6+/-3.3 microm, p=0.002) and showed a widespread loss of smooth muscle cells.

CONCLUSIONS

Mitoxantrone loading of a stent-graft inhibited the formation of a neointima. However, important regenerative processes were prevented as well, indicating a local overdose. More experiments using lower doses are warranted.

Modulating conjunctival wound healing

Advances in molecular and cell biology have led to an expansion in our knowledge and understanding of the processes involved in wound healing. We review existing and potential therapies modulating the conjunctival scarring response, with particular reference to glaucoma filtration surgery. We discuss how the refinement of present antimetabolite regimens can minimise complications and improve surgical results, and advocate their use in carefully selected patient groups. Perhaps the most promising approach is targeting biological molecules. Hence, use of fully human neutralising monoclonal antibodies to the growth factor TGF beta has potential as a useful strategy for modifying conjunctival scarring. Combination therapies may also afford an improved therapeutic index. It is hoped that future therapies can offer safer, more specific, focal and titratable treatment, with far-reaching clinical applications.

Wound healing modulation after glaucoma surgery

Recent developments in molecular and cell biology have made a major impact on our understanding of the wound healing process and its modification. In this article, the spectrum of therapies that are either currently available or have potential application as modulators of the scarring response following glaucoma surgery are reviewed. Refinement of existing antimetabolite regimens can improve surgical results, especially in carefully selected patient groups. However, the most promising new approach appears to be using molecular-based therapies, such as fully human neutralizing monoclonal antibodies, designed to target specific molecules in the scarring response. Such strategies ultimately offer the potential of safer, more specific, focal, and titratable treatment, with far-reaching clinical applications.