Antinociceptive effects of carbidopa levodopa on normal rats and Parkinson's disease mice.

Carbidopa levodopa is widely used to ameliorate motor symptoms of Parkinson's disease (PD) patients. Pain is one of common symptoms of PD. The aim of this experiment is to study antinociceptive effects of carbidopa levodopa on normal rats and PD mice. Rats were intragastrically treated with carbidopa levodopa and the hind paw withdrawal latency (HWL) was investigated. PD mouse model was prepared with MPTP and then the antinociceptive effects of carbidopa levodopa on PD mice were evaluated. In normal rats, the HWL to thermal stimulus was augmented after carbidopa levodopa administration (p<0.05 or p<0.01) and carbidopa levodopa increased the HWL (p<0.05 or p<0.01) to mechanical stimulus. In PD mice, carbidopa levodopa elevated the HWL of the thermal stimulus in PD mice (p<0.05). Furthermore, the HWL in the inflammatory pain of PD mice was also increased by carbidopa levodopa treatmet (p<0.01). The current findings indicate that carbidopa levodopa has an antinociceptive effects in normal rats and PD mice. The analgesic effect of carbidopa levodopa on patients with or without PD is worth studying in further research.

Lipoprotein complex of equine lysozyme with oleic acid (ELOA) interactions with the plasma membrane of live cells.

Recent evidence supports the idea that early aggregates, protein, and lipoprotein oligomers but not large aggregates like fibrils that are formed at late stages of the aggregation process are responsible for cytotoxicity. Oligomers can interact with the cellular plasma membrane affecting its structure and/or dynamics or may be taken up by the cells. In either case, disparate cascades of molecular interactions are activated in the attempt to counteract the disturbance induced by the oligomers. If unsuccessful, cell death follows. Here, we study the molecular and cellular mechanisms underlying PC12 cell death caused by ELOA oligomers. ELOA, a lipoprotein complex formed by equine lysozyme (EL) and oleic acid (OA), induces cell death in all tested cell lines, but the actual mechanism of its action is not known. We have used methods with single-molecule sensitivity, fluorescence correlation spectroscopy (FCS), fluorescence cross-correlation spectroscopy (FCCS), and confocal laser scanning microscopy (CLSM) imaging by avalanche photodiodes (APD), so-called APD imaging, to study ELOA interactions with the plasma membrane in live PC12 cells. We detected ELOA accumulation in the cell surroundings, observed ELOA interactions with the plasma membrane, and local changes in plasma membrane lipid dynamics in the vicinity of ELOA complexes. These interactions resulted in plasma membrane rupture, followed by rapid influx and distribution of ELOA inside the already dead cell. In order to probe the ELOA-plasma membrane interaction sites at the molecular and atomic levels, the ELOA complexes were further studied by photochemically induced dynamic nuclear polarization (photo-CIDNP) spectroscopy, nuclear magnetic resonance (NMR) and atomic force microscopy (AFM). We observed a novel mechanism of oligomer toxicity-cell death induced by continuous disturbance of the plasma membrane, eventually causing permanent plasma membrane damage and identified the sites in ELOA that are potentially involved in the interactions with the plasma membrane.

Necrostatin-1 inhibits the degeneration of neural cells induced by aluminum exposure.

PURPOSE: There are many in vivo and in vitro studies suggested the involvement of apoptosis in neurodegenerative processes. There is considerable evidence that various complex events may contribute to neural cell death. The present study focuses on the underlined neurodegenerative mechanism and the preventive effect of necrostatin-1 (Nec-1) on neural cell death induced by aluminum (Al). METHODS: Al-exposed primary cultures of newborn mice cortical cells were separately treated with 3-methylamphetamine (3-MA), benzyloxycarbonylvalyl-alanyl-aspartic acid (O-methyl)-fluoro-methylketone (zVAD-fmk), and Nec-1, the cell viability analysis was used to evaluate cell damage from apoptosis, necroptosis and autophagy. Morphology of neural cells treated with 2 mM Al, and 2 mM Al plus 60 µM Nec-1 were examined by fluorescent microscope, and the cell death rates were quantified by cytometry. For the in vivo experiments, male ICR mice were microinjected with normal saline, 2 mM Al, and 2 mM Al plus Nec-1 at the concentrations of 2 mM, 4 mM and 8 mM into the lateral cerebral ventricles. The Morris water maze task was performed in 20 days after intracerebroventricular injection, Nissl staining was used to demonstrate the loss of Nissl substance and the number of neural cells, and western blot was used to analyze the expressing of cell death and Alzheimer's disease related proteins. RESULTS: The cell viabilities inhibited by Al could be enhanced by 3-MA, zVAD-fmk and Nec-1, of which Nec-1 improved the cell viability most significantly. Furthermore, the cell viability of neural cells treated with Nec-1 increased concentration-dependently, and the expressions of cell death-related proteins were decreased also in a concentration-dependent manner. The in vivo experiments indicated that administration of Nec-1 on Al-treated mice significantly improved learning and memory retention in the Morris water maze task, decreased the neural cells death and inhibited the expression of Alzheimer's disease related proteins in the mice brain. CONCLUSIONS: The present study provides the first direct evidence of a connection between necroptosis and neurodegeneration, which indicates that necroptosis is involved in neurodegenerative cell death. Furthermore, Nec-1 may be useful for the prevention and treatment of neurodegenerative disorders.