Molecular cloning, sequence analysis, and cadmium stress-rated expression changes of BTG1 in freshwater pearl mussel (Hyriopsis schlegelii)

Aplysia Neurons as a Model of Alzheimer's Disease: Shared Genes and Differential Expression

Although Alzheimer’s disease (AD) is the most common form of dementia in the United States, development of therapeutics has proven difficult. Invertebrate alternatives to current mammalian AD models have been successfully employed to study the etiology of the molecular hallmarks of AD. The marine snail Aplysia californica offers a unique and underutilized system in which to study the physiological, behavioral, and molecular impacts of AD. Mapping of the Aplysia proteome to humans and cross-referencing with two databases of genes of interest in AD research identified 898 potential orthologs of interest in Aplysia. Included among these orthologs were alpha, beta and gamma secretases, amyloid-beta, and tau. Comparison of age-associated differential expression in Aplysia sensory neurons with that of late-onset AD in the frontal lobe identified 59 ortholog with concordant differential expression across data sets. The 21 concordantly upregulated genes suggested increased cellular stress and protein dyshomeostasis. The 47 concordantly downregulated genes included important components of diverse neuronal processes, including energy metabolism, mitochondrial homeostasis, synaptic signaling, Ca⁺⁺ regulation, and cellular cargo transport. Compromised functions in these processes are known hallmarks of both human aging and AD, the ramifications of which are suggested to underpin cognitive declines in aging and neurodegenerative disease.

Molecular characterization of an inhibitor of apoptosis protein (IAPs) in freshwater pearl mussel, Hyriopsis schlegelii

The inhibitor of apoptosis proteins (IAPs) played important roles in inhibiting the apoptosis of tumor cells by regulating caspase activity in mammals. In this study, we first cloned the full-length cDNA sequence of IAPs gene (designated as Hs-IAPs) in Hyriopsis schlegelii. The Hs-IAPs gene contained an open reading frame of 1719 nucleotides, encoding a predicted protein of 572 amino acids. qRT-PCR assay indicated that the Hs-IAPs gene was ubiquitously expressed in different tissues, and the highest expression level was in gills. Furthermore, we purified and obtained the recombinant protein of Hs-IAPs which showed a molecular weight of 82.5 kDa. We used H₂O₂ stimulation experiment to explore the possible function of Hs-IAPs. The results showed that the percentage of viable cells significantly increased following the Hs-IAPs concentration. These indicated that the Hs-IAPs may play a role in anti-oxidation causing by H₂O₂, and its anti-oxidative may be crucial in the process of apoptosis.