Journal: Neural Regeneration Research
Article Title: Chitosan alleviates symptoms of Parkinson’s disease by reducing acetate levels, which decreases inflammation and promotes repair of the intestinal barrier and blood–brain barrier
doi: 10.4103/NRR.NRR-D-23-01511
Figure Lengend Snippet: Chitosan may reduce acetate levels, thereby activating the PPARD-AMPK signaling pathway, which promotes repair of the intestinal barrier and reduces neuroinflammation in an MPTP-induced mouse model of PD. (A, B) Western blot analysis of p-AMPK, AMPK, and PPARD levels in mouse colon tissue ( n = 3/group). Treatment with acetate significantly increased p-AMPK and PPARD expression. (C) Treatment with a PPARD antagonist significantly decreased mouse body weight ( n = 6/group). (D) There were no significant differences in fall latency among the groups in the rotarod test, which was used to assess motor dysfunction ( n = 6/group). (E–G) PPARD antagonist treatment significantly decreased PPARD, TH, ZO-1, and occludin expression, as determined by western blot ( n = 3/group). (H) Immunofluorescence staining for ZO-1 (green, Alexa Fluor 488) and occludin (red, Alexa Fluor 594) in mouse colon tissue ( n = 3/group). The PPARD antagonist treatment group exhibited markedly reduced ZO-1 and occludin mRNA expression levels in colon tissue. Scale bars: 10 μm. (I) QPCR was used to measure the mRNA levels of IL-1β, IL-6, IL-8, IL-10, TNF-α, and iNOS in mouse colon tissue ( n = 3/group). Treatment with the PPARD antagonist increased IL-6 and TNF-α mRNA levels, while IL-8 and iNOS levels were reduced. (J) ELISA was used to detect IL-1β, IL-6, IL-10, and TNF-α expression levels in mouse plasma ( n = 5/group). IL-1β, IL-6, and TNF-α expression levels were significantly increased in the PPARD antagonist treatment group. (K) QPCR was used to measure mRNA levels of IL-1β, IL-6, IL-8, IL-10, TNF-α, and iNOS in the SN ( n = 3/group). Treatment with the PPARD antagonist significantly increased the mRNA levels of IL-1β, IL-6, and IL-8. (L) Treatment with the PPARD antagonist reduced p-AMPK, but not AMPK, expression ( n = 3/group). GAPDH was used as the internal reference. All data are presented as the mean ± SD. All experiments were repeated at least three times. * P < 0.05 (one-way analysis of variance followed by Tukey’s multiple comparisons test (A, B) or unpaired t -test (C–L)). AMPK: Adenosine 5′-monophosphate-activated protein kinase; DAPI: 4′,6-diamidino-2-phenylindole; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; IL-1β: interleukin-1 Beta; IL-6: interleukin-6; IL-8: interleukin-8; IL-10: interleukin-10; iNOS: inductible nitric oxide synthase; n.s.: not significant; NaA: sodium acetate; p-AMPK: phosphorylation adenosine 5′-monophosphate-activated protein kinase; PD: Parkinson’s disease; PPARD: peroxisome proliferator-activated receptor delta; QPCR: quantitative polymerase chain reaction; SN: substantia nigra; TH: tyrosine hydroxylase; TNF-α: tumor necrosis factor alpha; ZO-1: Zonula occludens-1.
Article Snippet: The primary antibodies used were as follows: rabbit anti-glyceraldehyde-3-phosphate dehydrogenase polyclonal antibody (GAPDH; 1:10,000, Proteintech, Wuhan, Hubei, China, Cat# 10494-1-AP, RRID: AB_2263076), rabbit anti-TH polyclonal antibody (1:5000, Proteintech, Cat# 25859-1-AP, RRID: AB_2716568), rabbit anti-zonula occludens-1 polyclonal antibody (ZO-1; 1:5000, Proteintech, Cat# 21773-1-AP, RRID: AB_10733242), rabbit anti-occludin polyclonal antibody (1:15,000, Proteintech, Cat# 27260-1-AP, RRID: AB_2880820), rabbit anti-AMPKα polyclonal antibody (1:1000, Cell Signaling Technology, Danvers, Massachusetts, USA, Cat# 2532, RRID: AB_330331), rabbit anti-phospho-AMPKα monoclonal antibody (1:1000, Cell Signaling Technology, Cat# 2535, RRID: AB_331250), and rabbit anti-PPARD polyclonal antibody (1:1000, Abcam, Cambridge, UK, Cat# ab23673, RRID: AB_2165902).
Techniques: Western Blot, Expressing, Immunofluorescence, Staining, Enzyme-linked Immunosorbent Assay, Clinical Proteomics, Phospho-proteomics, Real-time Polymerase Chain Reaction