Novel anti-angiogenic PEDF-derived small peptides mitigate choroidal neovascularization.

Abnormal migration and proliferation of endothelial cells (EC) drive neovascular retinopathies. While anti-VEGF treatment slows progression, pathology is often supported by decrease in intraocular pigment epithelium-derived factor (PEDF), an endogenous inhibitor of angiogenesis. A surface helical 34-mer peptide of PEDF, comprising this activity, is efficacious in animal models of neovascular retina disease but remains impractically large for therapeutic use.

Pre-metastatic cancer exosomes induce immune surveillance by patrolling monocytes at the metastatic niche.

Metastatic cancers produce exosomes that condition pre-metastatic niches in remote microenvironments to favor metastasis. In contrast, here we show that exosomes from poorly metastatic melanoma cells can potently inhibit metastasis to the lung. These "non-metastatic" exosomes stimulate an innate immune response through the expansion of Ly6C patrolling monocytes (PMo) in the bone marrow, which then cause cancer cell clearance at the pre-metastatic niche, via the recruitment of NK cells and TRAIL-dependent killing of melanoma cells by macrophages.

Impairments in age-dependent ubiquitin proteostasis and structural integrity of selective neurons by uncoupling Ran GTPase from the Ran-binding domain 3 of Ranbp2 and identification of novel mitochondrial isoforms of ubiquitin-conjugating enzyme E2I (ubc9) and Ranbp2.

The Ran-binding protein 2 (Ranbp2/Nup358) is a cytoplasmic and peripheral nucleoporin comprised of 4 Ran-GTP-binding domains (RBDs) that are interspersed among diverse structural domains with multifunctional activities. Our prior studies found that the RBD2 and RBD3 of Ranbp2 control mitochondrial motility independently of Ran-GTP-binding in cultured cells, whereas loss of Ran-GTP-binding to RBD2 and RBD3 are essential to support cone photoreceptor development and the survival of mature retinal pigment epithelium (RPE) in mice. Here, we uncover that loss of Ran-GTP-binding to RBD3 alone promotes the robust age-dependent increase of ubiquitylated substrates and S1 subunit (Pmsd1) of the 19S cap of the proteasome in the retina and RPE and that such loss in RBD3 also compromises the structural integrity of the outer segment compartment of cone photoreceptors only and without affecting the viability of these neurons.

Pro-survival and pro-growth effects of stress-induced nitric oxide in a prostate cancer photodynamic therapy model.

We discovered recently that human breast cancer cells subjected to photodynamic therapy (PDT)-like oxidative stress localized in mitochondria rapidly upregulated nitric oxide synthase-2 (NOS2) and nitric oxide (NO), which increased resistance to apoptotic photokilling. In this study, we asked whether human prostate cancer PC-3 cells would exploit NOS2/NO similarly and, if so, how proliferation of surviving cells might be affected. Irradiation of photosensitized PC-3 cells resulted in a rapid (<1 h), robust (~12-fold), and prolonged (∼20 h) post-irradiation upregulation of NOS2.

Cytoprotective signaling associated with nitric oxide upregulation in tumor cells subjected to photodynamic therapy-like oxidative stress.

Photodynamic therapy (PDT) employs photoexcitation of a sensitizer to generate tumor-eradicating reactive oxygen species. We recently showed that irradiating breast cancer COH-BR1 cells after treating with 5-aminolevulinic acid (ALA, a pro-sensitizer) resulted in rapid upregulation of inducible nitric oxide (NO) synthase (iNOS). Apoptotic cell killing was strongly enhanced by an iNOS inhibitor (1400W), iNOS knockdown (kd), or a NO scavenger, suggesting that NO was acting cytoprotectively.

Rapid upregulation of cytoprotective nitric oxide in breast tumor cells subjected to a photodynamic therapy-like oxidative challenge.

Many tumor cells produce nitric oxide (NO) as an antiapoptotic/progrowth molecule which also promotes antiogenesis and tumor expansion. This study was designed to examine possible antagonistic effects of endogenous NO on tumor eradication by photodynamic therapy (PDT). Using COH-BR1 breast cancer cells sensitized in mitochondria with 5-aminolevulinic acid (ALA)-generated protoporphyrin IX as a model for ALA-based PDT, we found that caspase-9 activation and apoptotic death following irradiation were strongly enhanced by 1400W, an inhibitor of inducible nitric oxide synthase (iNOS).

Cytoprotective induction of nitric oxide synthase in a cellular model of 5-aminolevulinic acid-based photodynamic therapy.

Photodynamic therapy (PDT) employs a photosensitizing agent, molecular oxygen, and visible light to generate reactive species that kill tumor and tumor vasculature cells. Nitric oxide produced by these cells could be procarcinogenic by inhibiting apoptosis or promoting angiogenesis and tumor growth. The purpose of this study was to determine whether tumor cells upregulate NO as a cytoprotective measure during PDT.

Signaling events in apoptotic photokilling of 5-aminolevulinic acid-treated tumor cells: inhibitory effects of nitric oxide.

Antitumor photodynamic therapy (PDT) employs a photosensitizing agent, molecular oxygen, and visible light to produce reactive oxygen species that can destroy tumor and tumor vasculature cells. NO produced by these cells could be procarcinogenic by inhibiting apoptosis and promoting angiogenesis and tumor growth. We recently showed that NO from a chemical donor or activated macrophages makes COH-BR1 breast tumor cells more resistant to photokilling sensitized by 5-aminolevulinic acid (ALA)-generated protoporphyrin IX (PpIX).

Photoreceptor IFT complexes containing chaperones, guanylyl cyclase 1 and rhodopsin.

Intraflagellar transport (IFT) provides a mechanism for the transport of cilium-specific proteins, but the mechanisms for linkage of cargo and IFT proteins have not been identified. Using the sensory outer segments (OS) of photoreceptors, which are derived from sensory cilia, we have identified IFT-cargo complexes containing IFT proteins, kinesin 2 family proteins, two photoreceptor-specific membrane proteins, guanylyl cyclase 1 (GC1, Gucy2e) and rhodopsin (RHO), and the chaperones, mammalian relative of DNAJ, DnajB6 (MRJ), and HSC70 (Hspa8). Analysis of these complexes leads to a model in which MRJ through its binding to IFT88 and GC1 plays a critical role in formation or stabilization of the IFT-cargo complexes.

Purification and characterization of a novel protease from the latex of Pedilanthus tithymaloids.

A novel protease was purified to homogeneity from the latex of Pedilanthus tithymaloids by a simple purification procedure involving ammonium sulfate precipitation and cation-exchange chromatography. The molecular weight of the protease was estimated to be approximately 63.1 kDa and the extinction coefficient (epsilon(1%)(280nm)) was 28.

RanBP2 modulates Cox11 and hexokinase I activities and haploinsufficiency of RanBP2 causes deficits in glucose metabolism.

The Ran-binding protein 2 (RanBP2) is a large multimodular and pleiotropic protein. Several molecular partners with distinct functions interacting specifically with selective modules of RanBP2 have been identified. Yet, the significance of these interactions with RanBP2 and the genetic and physiological role(s) of RanBP2 in a whole-animal model remain elusive.

Multiple intermediate conformations of jack bean urease at low pH: anion-induced refolding.

Structural and functional characteristics of jack bean urease (JBU), a hexameric enzyme having identical subunits, were investigated under neutral as well as acidic conditions by using CD, fluorescence, ANS binding and enzyme activity measurements. At low pH and low ionic strength, JBU exists in a partially unfolded state (U(A)-state), having predominantly beta structure and no tertiary interactions along with a strong ANS binding. Addition of salts like NaCl, KCl and Na(2)SO(4) to the U(A)-state induces refolding resulting in structural propensities similar to that of native hexamer.