Regenerative responses of rabbit corneal endothelial cells to stimulation by fibroblast growth factor 1 (FGF1) derivatives, TTHX1001 and TTHX1114.

Utilising rabbit corneal endothelial cells (CEC) in three different paradigms, two human FGF1 derivatives (TTHX1001 and TTHX1114), engineered to exhibit greater stability, were tested as proliferative agents. Primary CECs and mouse NIH 3T3 cells treated with the two FGF1 derivatives showed equivalent EC50 ranges (3.3-24 vs.1.9-16. ng/mL) and, in organ culture, chemically lesioned corneas regained half of the lost endothelial layer in three days after treatment with the FGF1 derivatives as compared to controls. In vivo, following cryolesioning, the CEC monolayer, as judged by specular microscopy, regenerated 10-11 days faster when treated with TTHX1001. Over two weeks, all treated eyes showed clearing of opacity about twice that of untreated controls. In all three rabbit models, both FGF1 derivatives were effective in inducing CEC proliferation over control conditions, supporting the prediction that these stabilised FGF1 derivatives can potentially regenerate corneal endothelial deficits in humans.

Characterization of a Novel Caveolin Modulator That Reduces Vascular Permeability and Ocular Inflammation.

Purpose: Caveolin (Cav) regulates various aspect of endothelial cell signaling and cell-permeable peptides (CPPs) fused to domains of Cav can reduce retinal damage and inflammation in vivo. Thus, the goal of the present study was to identify a novel CPP that improves delivery of a truncated Cav modulator in vitro and in vivo. Methods: Phage display technology was used to identify a small peptide (RRPPR) that was internalized into endothelial cells. Fusions of Cav with the peptide were compared to existing molecules in three distinct assays, vascular endothelial growth factor-A (VEGF) induced nitric oxide (NO) release, VEGF induced vascular leakage, and in a model of immune mediated uveitis. Results: RRPPR was internalized efficiently and was potent in blocking NO release. Fusing RRPPR with a minimal Cav inhibitory domain (CVX51401) dose-dependently blocked NO release, VEGF induced permeability, and retinal damage in a model of uveitis. Conclusions: CVX51401 is a novel Cav modulator that reduces VEGF and immune mediated inflammation. Translational Relevance: CVX51401 is an optimized Cav modulator that reduces vascular permeability and ocular inflammation that is poised for clinical development.

Proliferation of Human Corneal Endothelia in Organ Culture Stimulated by Wounding and the Engineered Human Fibroblast Growth Factor 1 Derivative TTHX1114.

Purpose: Corneal endothelial dystrophies are characterized by endothelial cell loss and dysfunction. Recent evidence suggests that corneal endothelial cells (CECs) can regenerate although they do not do so under normal conditions. This work sought to test whether CECs can be stimulated to proliferate in organ culture by wounding and/or by treatment with the engineered human fibroblast growth factor 1 (FGF1) derivative TTHX1114. Methods: Human donor corneas obtained from eye banks were maintained in organ culture in the presence or absence of TTHX1114. Wounds in the corneas were created by quartering the corneas. The CEC monolayer was identified as a regular layer by Hoechst staining of the nuclear DNA with cell outlines delineated by immunohistochemical identification of ZO-1. Nuclei and nuclei incorporating 5-ethynyl-2'-deoxyuridine (EdU) were counted using ImageJ. Results: CECs in normal corneas in undisturbed monolayers had low, but measurable, rates of proliferation. CECs at the edge of a wound had higher rates of proliferation, probably due to the release of contact inhibition. TTHX1114 increased proliferation at wound edges. After 7 days of culture, proliferating CECs formed contiguous groups of labeled cells that did not migrate away from one another. TTHX1114-treated cells, including the EdU labeled proliferating cells, retained normal morphology, including cell/cell junction ZO-1 staining. Conclusions: Proliferation of CECs in organ-cultured corneas is low, but can be stimulated by wounding or by the administration of TTHX1114 with the effects of each being additive. The CEC monolayer appears to have a population of progenitor cells that are susceptible to stimulation.

A brief history of FASEB and its programs and activities.

The Federation of American Societies for Experimental Biology (FASEB) was formed in 1912 to serve the needs of its four charter societies. Its growth, from these organizations with a little more than 300 members to nearly 30 societies with over 100 000 members, is a tribute to its ability to respond to the changing structure and needs of the experimental biology community. The Federation began as a loosely constructed, single-purpose organization established to facilitate the coordination of the annual meeting of its four member societies. Following World War II, the limitations of this informal structure became readily apparent, and the development of a professional staff under the leadership of Milton O. Lee ushered in the second phase of FASEB's history. Lee oversaw a period of substantial institutional growth, but when he retired in the mid-1960s the unresolved issues of governance and member autonomy loomed large. These became increasingly divisive sources of organizational friction and were not meaningfully resolved until the Williamsburg Retreat of 1989 restructured the Federation and initiated the third phase of its existence. The changes made as a result of this pivotal event gave FASEB a new raison d'etre (public affairs) and made the organization attractive to many other biomedical research societies. Membership grew rapidly in the 1990s and early years of the 21st century. This larger membership, along with changing financial relationships, present new challenges for the Federation and are precipitating another restructuring.

Cancer Proteomics and the Elusive Diagnostic Biomarkers.

Despite progress in genomic and proteomic technology and applications, the validation of cancer biomarkers of use as clinical early detection diagnostics has remained elusive. As described in this brief viewpoint, there are now recognized to be many types of clinical biomarkers and proteomic analyses, particularly when combined with other 'omic analyses, have been effective in many such biomarker identifications. However, in the area of early diagnosis of cancers, the problems associated with the conversion from identification to diagnostic have largely not been overcome. Notably, the Clinical Proteomic Tumor Analysis Consortium (CPTAC) of the National Cancer Institute (NCI), has been particularly successful in refining the analytical steps needed to tackle this challenging issue and has provided positive insight into how to solve many of the underlying problems. The potential for developing clinical diagnostics for early detection of highly lethal cancers and possible new therapeutic strategies through proteomic analyses, as seen through these CPTAC successes, is more promising than ever.

An Engineered Human Fibroblast Growth Factor-1 Derivative, TTHX1114, Ameliorates Short-term Corneal Nitrogen Mustard Injury in Rabbit Organ Cultures.

Purpose: Organ cultures of rabbit corneas have been used to ascertain the effectiveness of a human fibroblast growth factor (FGF)-1 derivative (TTHX1114), lacking cysteine residues, to protect against and/or repair epithelial lesions following exposure to nitrogen mustard (NM). Methods: Rabbit corneas were exposed to NM and cultured for up to 14 days, with or without drug (TTHX1114). At specified times, tissue was examined by histopathology and graded by a novel composite scale. Proliferation was measured by 5-ethynyl-2'-deoxyuridine (EdU) incorporation, and the expression of native FGF-1 and ADAM-17 after NM exposure was determined by immunofluorescence. Results: Rabbit corneas, exposed to a single dose of NM, showed a nearly complete loss of epithelial cells by day 6 but were significantly regenerated by day 14. When treated continuously with TTHX1114 following vesicant exposure, the losses remained at day 2 levels. The loss of keratocytes in the stroma was not affected by TTHX1114. EdU incorporation over the same time course showed a steady increase in tissue that had not been treated with TTHX1114, while corneas that were treated with the drug showed a higher percent incorporation initially, which then decreased, indicating the strong proliferative response to TTHX1114. ADAM-17 was not significantly altered by TTHX1114 treatment. Corneal epithelial FGF-1 disappeared after only 1 day following exposure to NM. Conclusions: TTHX1114 is protective against NM-induced damage of the corneal epithelium, possibly by supplying an NM-resistant source of trophic support and by stimulating regeneration of new epithelial cells. These responses underscore the potential value of TTHX1114 as an anti-vesicant therapeutic.

Nerve Growth Factor and Related Substances: A Brief History and an Introduction to the International NGF Meeting Series.

Nerve growth factor (NGF) is a protein whose importance to research and its elucidation of fundamental mechanisms in cell and neurobiology far outstrips its basic physiological roles. It was the first of a broad class of cell regulators, largely acting through autocrine and paracrine interactions which will be described herein. It was of similar significance in establishing the identity and unique roles of neurotrophic factors in the development and maintenance of the peripheral and central nervous systems. Finally, it contributed to many advances in the elaboration of cell surface receptor mechanisms and intracellular cell signaling. As such, it can be considered to be a "molecular Rosetta Stone". In this brief review, the highlights of these various studies are summarized, particularly as illustrated by their coverage in the 13 NGF international meetings that have been held since 1986.

Proteomics in India: A Report on a Brainstorming Meeting at Hyderabad, India.

The Centre for Cellular and Molecular Biology, Hyderabad, India, was host for an international forum, or "brainstorming meeting," on proteomics held in November 2014, which provided the opportunity to showcase proteomic science in India and to allow discussions between Indian scientists and students and several international visitors. This provided an amalgamation of speakers and participants whose interests lay mainly in developing and using mass-spectrometry-based proteomics to advance their research work. A week-long workshop with hands-on training in proteomic methodology followed the meeting.

Proteotranscriptomic Profiling of 231-BR Breast Cancer Cells: Identification of Potential Biomarkers and Therapeutic Targets for Brain Metastasis.

Brain metastases are a devastating consequence of cancer and currently there are no specific biomarkers or therapeutic targets for risk prediction, diagnosis, and treatment. Here the proteome of the brain metastatic breast cancer cell line 231-BR has been compared with that of the parental cell line MDA-MB-231, which is also metastatic but has no organ selectivity. Using SILAC and nanoLC-MS/MS, 1957 proteins were identified in reciprocal labeling experiments and 1584 were quantified in the two cell lines. A total of 152 proteins were confidently determined to be up- or down-regulated by more than twofold in 231-BR. Of note, 112/152 proteins were decreased as compared with only 40/152 that were increased, suggesting that down-regulation of specific proteins is an important part of the mechanism underlying the ability of breast cancer cells to metastasize to the brain. When matched against transcriptomic data, 43% of individual protein changes were associated with corresponding changes in mRNA, indicating that the transcript level is a limited predictor of protein level. In addition, differential miRNA analyses showed that most miRNA changes in 231-BR were up- (36/45) as compared with down-regulations (9/45). Pathway analysis revealed that proteome changes were mostly related to cell signaling and cell cycle, metabolism and extracellular matrix remodeling. The major protein changes in 231-BR were confirmed by parallel reaction monitoring mass spectrometry and consisted in increases (by more than fivefold) in the matrix metalloproteinase-1, ephrin-B1, stomatin, myc target-1, and decreases (by more than 10-fold) in transglutaminase-2, the S100 calcium-binding protein A4, and l-plastin. The clinicopathological significance of these major proteomic changes to predict the occurrence of brain metastases, and their potential value as therapeutic targets, warrants further investigation.

Nerve fibers infiltrate the tumor microenvironment and are associated with nerve growth factor production and lymph node invasion in breast cancer.

Infiltration of the tumor microenvironment by nerve fibers is an understudied aspect of breast carcinogenesis. In this study, the presence of nerve fibers was investigated in a cohort of 369 primary breast cancers (ductal carcinomas in situ, invasive ductal and lobular carcinomas) by immunohistochemistry for the neuronal marker PGP9.5. Isolated nerve fibers (axons) were detected in 28% of invasive ductal carcinomas as compared to only 12% of invasive lobular carcinomas and 8% of ductal carcinomas in situ (p = 0.0003). In invasive breast cancers, the presence of nerve fibers was observed in 15% of lymph node negative tumors and 28% of lymph node positive tumors (p = 0.0031), indicating a relationship with the metastatic potential. In addition, there was an association between the presence of nerve fibers and the expression of nerve growth factor (NGF) in cancer cells (p = 0.0001). In vitro, breast cancer cells were able to induce neurite outgrowth in PC12 cells, and this neurotrophic activity was partially inhibited by anti-NGF blocking antibodies. In conclusion, infiltration by nerve fibers is a feature of the tumor microenvironment that is associated with aggressiveness and involves NGF production by cancer cells. The potential participation of nerve fibers in breast cancer progression needs to be further considered.

NGF and ProNGF: Regulation of neuronal and neoplastic responses through receptor signaling.

Nerve growth factor (NGF) and its precursor (proNGF) are primarily considered as regulators of neuronal function that induce their responses via the tyrosine kinase receptor TrkA and the pan-neurotrophin receptor p75NTR. It has been generally held that NGF exerts its effects primarily through TrkA, inducing a cascade of tyrosine kinase-initiated responses, while proNGF binds more strongly to p75NTR. When this latter entity interacts with a third receptor, sortilin, apoptotic responses are induced in contrast to the survival/differentiation associated with the other two. Recent studies have outlined portions of the downstream phosphoproteome of TrkA in the neuronal PC12 cells and have clarified the contribution of individual docking sites in the TrkA endodomain. The patterns observed showed a similarity with the profile induced by the epidermal growth factor receptor, which is extensively associated with oncogenesis. Indeed, as with other neurotrophic factors, the distribution of TrkA and p75NTR is not limited to neuronal tissue, thus providing an array of targets outside the nervous systems. One such source is breast cancer cells, in which NGF and proNGF stimulate breast cancer cell survival/growth and enhance cell invasion, respectively. This latter activity is exerted via TrkA (as opposed to p75NTR) in conjunction with sortilin. Another tissue overexpressing proNGF is prostate cancer and here the ability of cancer cells to induce neuritogenesis has been implicated in cancer progression. These studies show that the non-neuronal functions of proNGF/NGF are likely integrated with their neuronal activities and point to the clinical utility of these growth factors and their receptors as biomarkers and therapeutic targets for metastasis and cancer pain.