A novel recombinant 6Aβ15-THc-C chimeric vaccine (rCV02) mitigates Alzheimer's disease-like pathology, cognitive decline and synaptic loss in aged 3 × Tg-AD mice

A Conantokin Peptide Con-T[M8Q] Inhibits Morphine Dependence with High Potency and Low Side Effects

N-methyl-D-aspartate receptor (NMDAR) antagonists have been found to be effective to inhibit morphine dependence. However, the discovery of the selective antagonist for NMDAR GluN2B with low side-effects still remains challenging. In the present study, we report a selective NMDAR GluN2B antagonist con-T[M8Q](a conantokin-T variant) that potently inhibits the naloxone-induced jumping and conditioned place preference of morphine-dependent mice at nmol/kg level, 100-fold higher than ifenprodil, a classical NMDAR NR2B antagonist. Con-T[M8Q] displays no significant impacts on coordinated locomotion function, spontaneous locomotor activity, and spatial memory mice motor function at the dose used. Further molecular mechanism experiments demonstrate that con-T[M8Q] effectively inhibited the transcription and expression levels of signaling molecules related to NMDAR NR2B subunit in hippocampus, including NR2B, p-NR2B, CaMKII-α, CaMKII-β, CaMKIV, pERK, and c-fos. The high efficacy and low side effects of con-T[M8Q] make it a good lead compound for the treatment of opiate dependence and for the reduction of morphine usage.

Improved synaptic and cognitive function in aged 3 × Tg-AD mice with reduced amyloid-β after immunotherapy with a novel recombinant 6Aβ15-TF chimeric vaccine

Alzheimer's disease (AD) is the most common progressive neurodegenerative disorder impairing memory and cognition. In this study, we describe the immunogenicity and protective efficacy of the novel recombinant 6Aβ15-TF chimeric antigen as a subunit protein vaccine for AD. Recombinant 6Aβ15-TF chimeric vaccine induced strong Aβ-specific humoral immune responses without Aβ-specific T cell immunity in C57/BL6 and 3 × Tg-AD mice at different ages. As an early immunotherapy model for AD, this vaccine induced high titers of long-lasting anti-Aβ42 antibodies in aged 3 × Tg-AD mice, which led to improve behavioral performance and markedly reduced the levels of insoluble and soluble Aβ and Aβ oligomers. In agreement with these findings, immunotherapy with 6Aβ15-TF prevented the Aβ-induced decrease of presynaptic and postsynaptic proteins in aged 3 × Tg-AD mice. Our results suggest that this novel and highly immunogenic recombinant 6Aβ15-TF chimeric vaccine provides neuroprotection in AD mice and can be considered an effective AD candidate vaccine.

Nitric Oxide: Exploring the Contextual Link with Alzheimer's Disease

Neuronal inflammation is a systematically organized physiological step often triggered to counteract an invading pathogen or to rid the body of damaged and/or dead cellular debris. At the crux of this inflammatory response is the deployment of nonneuronal cells: microglia, astrocytes, and blood-derived macrophages. Glial cells secrete a host of bioactive molecules, which include proinflammatory factors and nitric oxide (NO). From immunomodulation to neuromodulation, NO is a renowned modulator of vast physiological systems. It essentially mediates these physiological effects by interacting with cyclic GMP (cGMP) leading to the regulation of intracellular calcium ions. NO regulates the release of proinflammatory molecules, interacts with ROS leading to the formation of reactive nitrogen species (RNS), and targets vital organelles such as mitochondria, ultimately causing cellular death, a hallmark of many neurodegenerative diseases. AD is an enervating neurodegenerative disorder with an obscure etiology. Because of accumulating experimental data continually highlighting the role of NO in neuroinflammation and AD progression, we explore the most recent data to highlight in detail newly investigated molecular mechanisms in which NO becomes relevant in neuronal inflammation and oxidative stress-associated neurodegeneration in the CNS as well as lay down up-to-date knowledge regarding therapeutic approaches targeting NO.

Prophylactic immunotherapy of Alzheimer's disease using recombinant amyloid-β B-cell epitope chimeric protein as subunit vaccine

Alzheimer's disease (AD) is a neurodegenerative disorder that impairs memory and cognition. The neuropathological features of the disease include senile plaques (SPs), neurofibrillary tangles (NFTs) and neuronal loss in affected brain regions. The amyloid cascade hypothesis suggests that production and accumulation of excessive amyloid-β (Aβ) may be the main cause in the onset and progression of Alzheimer's disease. Active and passive immunotherapy targeting Aβ may be the most promising strategy to prevent or treat AD. This commentary focuses on the prophylactic immunotherapy of Alzheimer's disease using recombinant Aβ B-cell epitope chimeric protein as subunit vaccine targeting amyloid-β. We discuss the efficiency and perspective of this type of recombinant subunit protein vaccine and suggest a novel direction on the path to a successful AD immunotherapy. This novel chimeric protein immunogen as subunit vaccine of AD may be designed to mimic the assembly states of Aβ42 or oligomers using multivalent foldable Aβ1-15 (B cell epitopes of Aβ42) and foreign T helper (Th) epitopes (as the T cell epitopes of Aβ42) constructs.