OBJECTIVETo investigate the role of P38 mitogen-activated protein kinase (P38 MAPK) signaling pathway in regulating the expression of nuclear factor-κB (NF-κB) and inducible nitric oxide synthase (iNOS) in the substantia nigra (SN) of a mouse model of Parkinson's disease (PD).

METHODSC57BL/6N mice were treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to establish an subacute PD model, and the behavioral changes of the mice were observed. Immunohistochemistry and Western blotting were employed to detect the expressions of tyrosine hydroxylase (TH), NF-κB, iNOS and phosphorylated P38 (p-P38) in the midbrain before and after treatment with SB203580.

RESULTSCompared with the control mice, the PD mouse models presented with typical symptoms of PD and showed significantly increased number of p-P38-, NF-κB-, and iNOS-positive cells in the SN area (P<0.01) with significantly reduced number of TH-positive neurons (P<0.01). After SB203580 treatment, the number of p-P38-, NF-κB-, and iNOS-positive cells was reduced obviously (P<0.01) and the number of TH-positive neurons in the SN increased significantly in the PD model mice (P<0.01).

CONCLUSIONP38 MAPK signaling pathway may play an important role in modulating NF-κB and iNOS expression in the SN in the early stage of MPTP-induced subacute PD, and SB203580 can inhibit P38 signaling pathway to protect the DA neurons in PD model mice.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine ; Animals ; Disease Models, Animal ; Imidazoles ; MAP Kinase Signaling System ; Mice ; Mice, Inbred C57BL ; metabolism ; NF-kappa B ; metabolism ; Neurons ; Nitric Oxide Synthase Type II ; metabolism ; Parkinson Disease ; metabolism ; Phosphorylation ; Pyridines ; Substantia Nigra ; p38 Mitogen-Activated Protein Kinases ; metabolism

Plastics are widely used in daily life. Due to poor management and disposal, about 80% of plastic wastes were buried in landfills and eventually became land and ocean waste, causing serious environmental pollution. Recycling plastics is a desirable approach, but not applicable for most of the plastic waste. Microbial degradation offers an environmentally friendly way to degrade the plastic wastes, and this review summarizes the potential microbes, enzymes, and the underpinning mechanisms for degrading six most commonly used plastics including polyethylene terephthalate, polyethylene, polyvinyl chloride, polypropylene, polystyrene and polyurethane. The challenges and future perspectives on microbial degradation of plastics were proposed.
Biodegradation, Environmental ; Plastics ; Polyurethanes ; Recycling