Nucleic acid nanomedicines in Phase II/III clinical trials: translation of nucleic acid therapies for reprogramming cells.

This review presents an integrated analysis of the current-state-of-the-art in nucleic acid nanotherapies and highlights the importance of nanotechnology in the delivery of nucleic acid therapies. While there is no one dominant nanodesign, the diversity of nanodesigns and delivery of different siRNAs, miRNA and DNA to inhibit more than 20 targets in seven disease states in Phase II/III clinical trials reflects the potential of nucleic acid therapies to treat intractable diseases and non-druggable targets. We provide benchmarks to aid in comparing the design, proof-of-concept studies and clinical trials. From this, we demonstrate the importance of generating a strategic framework for integrating clinical 'wish lists' for a means to treat intractable diseases with engineering 'design checklists' for nucleic acid nanotherapies.

Evaluation of expansile nanoparticle tumor localization and efficacy in a cancer stem cell-derived model of pancreatic peritoneal carcinomatosis.

AIM: To evaluate the tumor localization and efficacy pH-responsive expansile nanoparticles (eNPs) as a drug delivery system for pancreatic peritoneal carcinomatosis (PPC) modeled in nude rats. METHODS & MATERIALS: A Panc-1-cancer stem cell xeno1graft model of PPC was validated in vitro and in vivo. Tumor localization was tracked via in situ imaging of fluorescent eNPs. Survival of animals treated with paclitaxel-loaded eNPs (PTX-eNPs) was evaluated in vivo. RESULTS: The Panc-1-cancer stem cell xenograft model recapitulates significant features of PPC. Rhodamine-labeled eNPs demonstrate tumor-specific, dose- and time-dependent localization to macro- and microscopic tumors following intraperitoneal injection. PTX-eNPs are as effective as free PTX in treating established PPC; but, PTX-eNPs result in fewer side effects. CONCLUSION: eNPs are a promising tool for the detection and treatment of PPC.

Prestroke proteomic changes in cerebral microvessels in stroke-prone, transgenic[hCETP]-Hyperlipidemic, Dahl salt-sensitive hypertensive rats.

Stroke is the third leading cause of death in the United States with high rates of morbidity among survivors. The search to fill the unequivocal need for new therapeutic approaches would benefit from unbiased proteomic analyses of animal models of spontaneous stroke in the prestroke stage. Since brain microvessels play key roles in neurovascular coupling, we investigated prestroke microvascular proteome changes. Proteomic analysis of cerebral cortical microvessels (cMVs) was done by tandem mass spectrometry comparing two prestroke time points. Metaprotein-pathway analyses of proteomic spectral count data were done to identify risk factor-induced changes, followed by QSPEC-analyses of individual protein changes associated with increased stroke susceptibility. We report 26 cMV proteome profiles from male and female stroke-prone and non-stroke-prone rats at 2 months and 4.5 months of age prior to overt stroke events. We identified 1,934 proteins by two or more peptides. Metaprotein pathway analysis detected age-associated changes in energy metabolism and cell-to-microenvironment interactions, as well as sex-specific changes in energy metabolism and endothelial leukocyte transmigration pathways. Stroke susceptibility was associated independently with multiple protein changes associated with ischemia, angiogenesis or involved in blood brain barrier (BBB) integrity. Immunohistochemical analysis confirmed aquaporin-4 and laminin-α1 induction in cMVs, representative of proteomic changes with >65 Bayes factor (BF), associated with stroke susceptibility. Altogether, proteomic analysis demonstrates significant molecular changes in ischemic cerebral microvasculature in the prestroke stage, which could contribute to the observed model phenotype of microhemorrhages and postischemic hemorrhagic transformation. These pathways comprise putative targets for translational research of much needed novel diagnostic and therapeutic approaches for stroke.

Corroboration of Dahl S Q276L alpha1Na,K-ATPase protein sequence: impact on affinities for ligands and on E1 conformation.

OBJECTIVE: Multifactorial analyses support the hypothesis that alpha1Na,K-ATPase is a hypertension susceptibility gene in Dahl S rats. However, two studies report non-detection of the A1079T transversion underlying the Q276L substitution in Dahl S alpha1Na,K-ATPase questioning the validity of ATP1A1 as a hypertension susceptibility gene. To resolve this discordance, we investigated the issue at the protein level. DESIGN AND METHODS: We employed protein blot analysis using Q276L- and Q276-specific; antipeptide-specific antibodies; tested differential chymotrypsin cleavage efficiency, measured differential Na and K affinities of alpha1Na,K-ATPases in Dahl S and Dahl R renal membranes and determined amino acid sequences of purified Dahl S alpha1Na,K-ATPase chymotryptic-digest peptides. RESULTS: We detected Q276L variant protein in Dahl S rats; and Q276 wild-type variant in Dahl R, spontaneously hypertensive (SHR), Lewis and Wistar-Kyoto (WKY) rat kidney membranes. Q276L variant exhibits less chymotrypsin cleavage efficiency than the Q276 wild-type variant, consistent with the substitution of hydrophobic L for hydrophilic Q. Kinetic studies of kidney membranes detect increased Na affinity and decreased K affinity in renal Dahl S alpha1Na,K-ATPase compared with Dahl R. Protein sequencing of high pressure liquid chromatography (HPLC)-purified chymotrypsin digested 77 kDa peptide confirms Q276L substitution in the Dahl S alpha1Na,K-ATPase. CONCLUSIONS: Data demonstrate the existence and functional significance of the Q276L variant in Dahl S rats.

Attenuated hippocampus-dependent learning and memory decline in transgenic TgAPPswe Fischer-344 rats.

Alzheimer's disease (AD) is characterized by increased beta amyloid (Abeta) levels, extracellular Abeta deposits in senile plaques, neurofibrillary tangles, and neuronal loss. However, the physiological role of normal levels of Abeta and its parent protein, the amyloid precursor protein (APP) are unknown. Here we report that low-level transgenic (Tg) expression of the Swedish APP mutant gene (APPswe) in Fischer-344 rats results in attenuated age-dependent cognitive performance decline in 2 hippocampus-dependent learning and memory tasks compared with age-matched nontransgenic Fischer-344 controls. TgAPPswe rats exhibit mild increases in brain APP mRNA (56.8%), Abeta-42 (21%), and Abeta-40 (6.1%) peptide levels at 12 mo of age, with no extracellular Abeta deposits or senile plaques at 6, 12, and 18 mo of age, whereas 3- to 6-fold increases in Abeta levels are detected in plaque-positive human AD patients and transgenic mouse models. The data support the hypothesis that a threshold paradigm underlies Abeta-related pathology, below which APP expression may play a physiological role in specific hippocampus-dependent tasks, most likely related to its neurotrophic role.