Relationship between motor dysfunction and chewing movement in patients with Parkinson's disease: A transversal study

Umbilical cord blood-derived exosomes attenuate dopaminergic neuron damage of Parkinson's disease mouse model

BACKGROUND

Umbilical cord blood (UCB) is a rich source of multifunctional stem cells characterized by low immunogenicity. Recent research in the fields of aging and regenerative medicine has revealed the potential of human umbilical cord blood-derived exosomes (UCB-Exos) in promoting wound healing, anti-aging, and regeneration. However, their role in neurodegenerative diseases, specifically Parkinson's disease (PD), remains unexplored. This study investigates the potential therapeutic effects and underlying mechanisms of UCB-Exos on PD.

METHODS

Large extracellular vesicles (LEv), Exos, and soluble fractions (SF) of human UCB plasma were extracted to investigate their effects on motor dysfunction of the MPTP-induced PD mouse model and identify the key components that improve PD symptoms. UCB-Exos were administered by the caudal vein to prevent or treat the PD mouse model. The motor function and pathological markers were detected. Differentially expressed gene and KEGG enrichment pathways were screened by transcriptome sequence. MN9D and SH-SY5Y cells were cultured and evaluated for cell viability, oxidative stress, cell cycle, and aging-related indexes by qRT-PCR, western blot, immunofluorescence, and flow cytometry. The protein expression level of the MAPK p38 and ERK1/2 signaling pathway was detected by western blot.

RESULTS

We observed that LEv, Exos, and SF all exhibited potential in ameliorating motor dysfunction in MPTP-induced PD model mice, with UCB-Exos demonstrating the most significant effect. UCB-Exos showed comparable efficacy in preventing and treating motor dysfunction, cognitive decline, and substantia nigra pathological damage in PD mice. Further investigations revealed that UCB-Exos could potentially alleviate oxidative damage, aging and degeneration, and energy metabolism disorders in neurons. Transcriptome sequencing results corroborated that genes differentially expressed due to UCB-Exos were primarily enriched in the neuroactive ligand-receptor interaction, Dopaminergic synapse, and MAPK signaling pathway. We also observed that UCB-Exos significantly inhibited the hyperphosphorylation of the MAPK p38 and ERK1/2 signaling pathways both in vitro and in vivo.

CONCLUSIONS

Our study provides a comprehensive evaluation of UCB-Exos on the neuroprotective effects and suggests that inhibition of hyperphosphorylation of MAPK p38 and ERK 1/2 signaling pathways by regulating transcription levels of HspB1 and Ppef2 may be the key mechanism for UCB-Exos to improve PD-related pathological features.

Distinct mechanisms underlying the therapeutic effects of low-molecular-weight heparin and chondroitin sulfate on Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder influenced by various factors, including age, genetics, and the environment. Current treatments provide symptomatic relief without impeding disease progression. Previous studies have demonstrated the therapeutic potential of exogenous heparin and chondroitin sulfate in PD. However, their therapeutic mechanisms and structure-activity relationships remain poorly understood. In this study, low-molecular-weight heparin (L-HP) and chondroitin sulfate (L-CS) exhibited favorable therapeutic effects in a mouse model of PD. Proteomics revealed that L-HP attenuated mitochondrial dysfunction through its antioxidant properties, whereas L-CS suppressed neuroinflammation by inhibiting platelet activation. Two glycosaminoglycan (GAG)-binding proteins, manganese superoxide dismutase (MnSOD2) and fibrinogen beta chain (FGB), were identified as potential targets of L-HP and L-CS, and we investigated their structure-activity relationships. The IdoA2S-GlcNS6S/GlcNAc6S unit in HP bound to SOD2, whereas the GlcA-GalNAc4S and GlcA-GalNAc4S6S units in CS preferred FGB. Furthermore, N-S and 2-O-S in L-HP, and 4-O-S, 6-O-S, and -COOH in L-CS contributed significantly to the binding process. These findings provide new insights and evidence for the development and use of glycosaminoglycan-based therapeutics for PD.