Plastic waste worldwide is becoming a serious pollution problem for the planet. Various physical and chemical methods have been tested in attempts to remove plastic dumps. However, these have usually resulted in secondary pollution issues. Recently, the biodegradation of plastic by fungal and bacterial strains has been spotlighted as a promising solution to remove plastic wastes without generating secondary pollution. We have previously reported that a Pseudomonas aeruginosa strain isolated from the gut of a superworm is capable of biodegrading polystyrene (PS) and polyphenylene sulfide (PPS). Herein, we demonstrate the extraordinary biodegradative power of P. aeruginosa in efficiently depolymerizing four different types of plastics: PS, PPS, polyethylene (PE) and polypropylene (PP). We further compared biodegradation rates for these four plastic types and found that PE was biodegraded fastest, whereas the biodegradation of PP was the slowest. Moreover, the growth rates of P. aeruginosa were not always proportional to biodegradation rates, suggesting that the rate of bacterial growth could be influenced by the composition and properties of intermediate molecules produced during plastic biodegradation, and these may supply useful cellular precursors and energy. In conclusion, an initial screening system to select the most suitable bacterial strain to biodegrade certain types of plastic is particularly important and may be necessary to solve plastic waste problems both presently and in the future.

Amyotrophic lateral sclerosis (ALS) caused by mutation of superoxide dismutase 1 (SOD1), affects various cellular processes and results in the death of motor neurons with fatal defects. Currently, several neurological disorders associated with DNA damage are known to directly induce neurodegenerative diseases. In this research, we found that cytoplasmic restriction of SOD1G93A, which inhibited the nucleic translocation of SOD1WT, was directly related to increasing DNA damage in SOD1- mutated ALS disease. Our study showed that nucleic transport of DNA repair- processing proteins, such as p53, APEX1, HDAC1, and ALS- linked FUS were interfered with under increased endoplasmic reticulum (ER) stress in the presence of SOD1G93A. During aging, the unsuccessful recognition and repair process of damaged DNA, due to the mislocalized DNA repair proteins might be closely associated with the enhanced susceptibility of DNA damage in SOD1- mutated neurons. In addition, the co-expression of protein disulphide isomerase (PDI) directly interacting with SOD1 protein in neurons enhances the nucleic transport of cytoplasmic- restricted SOD1G93A. Therefore, our results showed that enhanced DNA damage by SOD1 mutation-induced ALS disease and further suggested that PDI could be a strong candidate molecule to protect neuronal apoptosis by reducing DNA damage in ALS disease.

The conversion of the normal cellular prion protein (PrPC) to the misfolded pathogenic scrapie prion protein (PrPSc) is the biochemical hallmark of prion replication. So far, various chemical compounds that inhibit this conformational conversion have been identified. Here, we report the novel anti-prion activity of SGI-1027 and its meta/meta analogue (M/M), previously known only as potent inhibitors of DNA methyltransferases (DNMTs). These compounds effectively decreased the level of PrPSc in cultured cells with permanent prion infection, without affecting PrPC at the transcriptional or translational levels. Furthermore, SGI-1027 prevented effective prion infection of the cells. In a PrP aggregation assay, both SGI-1027 and M/M blocked the formation of misfolded PrP aggregates, implying that binding of these compounds hinders the PrP conversion process. A series of binding and docking analyses demonstrated that both SGI-1027 and M/M directly interacted with the C-terminal globular domain of PrPC, but only SGI-1027 bound to a specific region of PrPC with high affinity, which correlates with its potent anti-prion efficacy. Therefore, we report SGI-1027 and related compounds as a novel class of potential anti-prion agents that preferentially function through direct interaction with PrPC.