Adjusting vascular permeability, leukocyte infiltration, and microglial cell activation to rescue dopaminergic neurons in rodent models of Parkinson's disease

Neuroprotective effects of a novel peptide through the Rho-integrin-Tie2 and PI3K/Akt pathways in experimental autoimmune encephalomyelitis model

Purpose: The interaction between inflammatory cells and integrin in the endothelium plays a key role during infiltration. Previous evidence has shown that synthetic C16 peptide selectively binds to integrins αvβ3 and α5β1 and exhibits a neuroprotective effect. It has also been reported to inhibit the differentiation of microglia into the M1 (pro-inflammatory) phenotype while promoting its differentiation to the M2 (anti-inflammatory) phenotype. This study aimed to investigate the mechanisms of action of the C16 peptide in multiple sclerosis using a rodent model. Methods: Molecular, morphological, and neurophysiological assays were used to investigate the neuroprotective effects of C16 peptide and related signaling pathways in a model of EAE. Results: The results showed that C16 significantly improved the clinical score and cortical somatosensory/motor evoked potential. It also alleviated inflammatory responses, including microglial activation and leukocyte infiltration, relieved the impairment of the brain blood barrier and edema, and reduced neuronal apoptosis, axonal loss, and demyelination induced by EAE. The C16 peptide increased the expressions of pTie-2 and Tie-2, integrin αvβ3, and α5β1 and activated the PI3K/Akt signal pathway but decreased the expression of Rho. Co-treatment of C16 with Tie-2 inhibitor and PI3K inhibitor LY294002 attenuated these effects of C16. Conclusion: The C16 peptide demonstrated neuroprotection in the EAE model through the integrin, Tie-2, and PI3K/Akt signaling pathways, and it could be a potential strategy for treating inflammation-related diseases in the central nervous system.

Inflammation, Autoimmunity and Neurodegenerative Diseases, Therapeutics and Beyond

Neurodegenerative disease (ND) incidence has recently increased due to improved life expectancy. Alzheimer's (AD) or Parkinson's disease (PD) are the most prevalent NDs. Both diseases are poly genetic, multifactorial and heterogenous. Preventive medicine, a healthy diet, exercise, and controlling comorbidities may delay the onset. After the diseases are diagnosed, therapy is needed to slow progression. Recent studies show that local, peripheral and age-related inflammation accelerates NDs' onset and progression. Patients with autoimmune disorders like inflammatory bowel disease (IBD) could be at higher risk of developing AD or PD. However, no increase in ND incidence has been reported if the patients are adequately diagnosed and treated. Autoantibodies against abnormal tau, β amyloid and α- synuclein have been encountered in AD and PD and may be protective. This discovery led to the proposal of immune-based therapies for AD and PD involving monoclonal antibodies, immunization/ vaccines, pro-inflammatory cytokine inhibition and anti-inflammatory cytokine addition. All the different approaches have been analysed here. Future perspectives on new therapeutic strategies for both disorders are concisely examined.

Novel nano-carriers with N-formylmethionyl-leucyl-phenylalanine-modified liposomes improve effects of C16-angiopoietin 1 in acute animal model of multiple sclerosis

Gradual loss of neuronal structure and function due to impaired blood-brain barrier (BBB) and neuroinflammation are important factors in multiple sclerosis (MS) progression. Our previous studies demonstrated that the C16 peptide and angiopoietin 1 (Ang-1) compound (C + A) could modulate inflammation and vascular protection in many models of MS. In this study, nanotechnology and a novel nanovector of the leukocyte chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) were used to examine the effects of C + A on MS. The acute experimental autoimmune encephalomyelitis (EAE) model of MS was established in Lewis rats. The C + A compounds were conjugated to control nano-carriers and fMLP-nano-carriers and administered to animals by intravenous injection. The neuropathological changes in the brain cortex and spinal cord were examined using multiple approaches. The stimulation of vascular injection sites was examined using rabbits. The results showed that all C + A compounds (C + A alone, nano-carrier C + A, and fMLP-nano-carrier C + A) reduced neuronal inflammation, axonal demyelination, gliosis, neuronal apoptosis, vascular leakage, and BBB impairment induced by EAE. In addition, the C + A compounds had minimal side effects on liver and kidney functions. Furthermore, the fMLP-nano-carrier C + A compound had better effects compared to C + A alone and the nano-carrier C + A. This study indicated that the fMLP-nano-carrier C + A could attenuate inflammation-related pathological changes in EAE and may be a potential therapeutic strategy for the treatment of MS and EAE.

Oral [60]fullerene reduces neuroinflammation to alleviate Parkinson's disease via regulating gut microbiome

Neuroinflammation is considered to drive the pathogenic process of neuronal degeneration in Parkinson's disease (PD). However, effective anti-neuroinflammation therapeutics for PD still remain dissatisfactory. Here we explore a robust therapeutic strategy for PD using anti-neuroinflammatory fullerenes. Methods: Oral fullerene was prepared by a ball-milling method. 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model was used to investigate the therapeutic effects and mechanisms of it. The gut microenvironment was evaluated by 16S rRNA gene sequencing, gas chromatography-mass spectrometry, quantitative polymerase chain reaction (Q-PCR), and western blot (WB). The neuroinflammation and neurodegeneration were evaluated by pathological analysis, Elisa kits, transmission electron microscopy, Q-PCR, WB and so on. Toxicity was assessed by weight, blood test and hematoxylin-eosin (HE) staining. Results: Oral fullerene therapeutic system that dissolved [60]fullerene into olive oil (abbreviated as OFO) was dexterously designed, which could reduce neuroinflammation via regulating the diversity of gut microbiome, increasing the contents of short chain fatty acids (SCFAs) and recovering the integrity of gut barrier. Accordingly, the reduction of neuroinflammation prevented dopaminergic neuronal degeneration. And thus, OFO significantly ameliorated motor deficits and fundamentally reversed dopamine (DA) loss in MPTP-induced PD mice. Of note, OFO exhibited low toxicity towards the living body. Conclusion: Our findings suggest that OFO is a safe-to-use, easy-to-apply, and prospective candidate for PD treatment in clinic, opening a therapeutic window for neuroinflammation-triggered neurodegeneration.

Co-Application of C16 and Ang-1 Improves the Effects of Levodopa in Parkinson Disease Treatment

BACKGROUND

Levodopa is regarded as a standard medication in Parkinson disease (PD) treatment. However, long-term administration of levodopa leads to levodopa-induced dyskinesia (LID), which can markedly affect patient quality of life. Previous studies have shown that neuroinflammation in the brain plays a role in LID and increases potential neuroinflammatory mediators associated with the side effects of levodopa.

OBJECTIVE

The treatment effect of C16 (a peptide that competitively binds integrin αvβ3 and inhibits inflammatory cell infiltration) and angiopoietin-1 (Ang-1; a vascular endothelial growth factor vital for blood vessel protection), along with levodopa, was evaluated in a rodent model of PD.

METHODS

We administered a combination of C16 and Ang-1 in a rodent model of PD induced by MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine). Seventy-five mice were randomly divided into five treatment groups: control, vehicle, levodopa, C16+Ang-1, and levodopa+C16+Ang-1. Behavioral, histological, and electrophysiological experiments were used to determine neuron function and recovery.

RESULTS

The results showed that C16+Ang-1 treatment alleviated neuroinflammation in the CNS and promoted the recovery effects of levodopa on neural function.

CONCLUSION

Our study suggests that C16+Ang-1 can compensate for the shortcomings of levodopa, improve the CNS microenvironment, and ameliorate the effects of levodopa. This treatment strategy could be developed as a combinatorial therapeutic in the future.