Protective role of madecassoside from Centella asiatica against protein L-isoaspartyl methyltransferase deficiency-induced neurodegeneration.

Protein L-isoaspartyl methyltransferase (PIMT/PCMT1) could repair l-isoaspartate (L-isoAsp) residues formed by deamidation of asparaginyl (Asn) residues or isomerization of aspartyl (Asp) residues in peptides and proteins during aging. Aside from abnormal accumulation of L-isoAsp, PIMT knockout (KO) mice mirrors some neuropathological hallmarks such as anxiety-like behaviors, impaired spatial memory and aberrant synaptic plasticity in the hippocampus of neurodegenerative diseases (NDs), including Alzheimer's disease (AD) and related dementias, and Parkinson's disease (PD). While some reports indicate the neuroprotective effect of madecassoside (MA) as a triterpenoid saponin component of Centella asiatica, its role against NDs-related anxiety and cognitive impairment remains unclear. Therefore, we investigated the effect of MA against anxiety-related behaviors in PIMT deficiency-induced mouse model of NDs. Results obtained from the elevated plus maze (EPM) test revealed that MA treatment alleviated anxiety-like behaviors in PIMT knockout mice. Furthermore, Real-time PCR, electroencephalogram (EEG) recordings, transmission electron microscopy analysis and ELISA were carried out to evaluate the expression of clock genes, sleep and synaptic function, respectively. The PIMT knockout mice were characterized by abnormal clock patterns, sleep disturbance and synaptic dysfunction, which could be improved by MA administration. Collectively, these findings suggest that MA exhibits neuroprotective effects associated with improved circadian rhythms sleep-wake cycle and synaptic plasticity in PIMT deficient mice, which could be translated to ameliorate anxiety-related symptoms and cognitive impairments in NDs.

Patient Confidential Data Hiding and Transmission System Using Amplitude Quantization in the Frequency Domain of ECG Signals.

The transform domain provides a useful tool in the field of confidential data hiding and protection. In order to protect and transmit patients' information and competence, this study develops an amplitude quantization system in a transform domain by hiding patients' information in an electrocardiogram (ECG). In this system, we first consider a non-linear model with a hiding state switch to enhance the quality of the hidden ECG signals. Next, we utilize particle swarm optimization (PSO) to solve the non-linear model so as to have a good signal-to-noise ratio (SNR), root mean square error (RMSE), and relative root mean square error (rRMSE). Accordingly, the distortion of the shape in each ECG signal is tiny, while the hidden information can fulfill the needs of physiological diagnostics. The extraction of hidden information is reversely similar to a hiding procedure without primary ECG signals. Preliminary outcomes confirm the effectiveness of our proposed method, especially an Amplitude Similarity of almost 1, an Interval RMSE of almost 0, and SNRs all above 30.

Involvement of protein L-isoaspartyl methyltransferase in the physiopathology of neurodegenerative diseases: Possible substrates associated with synaptic function.

Synaptic dysfunction is a typical pathophysiologic change in neurodegenerative diseases (NDs) such as Alzheimer's disease (AD), Parkinson's disease (PD), Hintington's disease (HD) and amyotrophic lateral sclerosis (ALS), which involves protein post-translational modifications (PTMs) including L-isoaspartate (L-isoAsp) formed by isomerization of aspartate or deamidation of asparagine. The formation of L-isoAsp could be repaired by protein L-isoaspartyl methyltransferase (PIMT). Some synaptic proteins have been identified as PIMT potential substrates and play an essential role in ensuring synaptic function. In this review, we discuss the role of certain synaptic proteins as PIMT substrates in neurodegenerative disease, thus providing therapeutic synapse-centered targets for the treatment of NDs.