Corneal confocal microscopy may help to distinguish Multiple System Atrophy from Parkinson's disease.

Multiple system atrophy (MSA) and Parkinson's disease (PD) have clinical overlapping symptoms, which makes differential diagnosis difficult. Our research aimed to distinguish MSA from PD using corneal confocal microscopy (CCM), a noninvasive and objective test. The study included 63 PD patients, 30 MSA patients, and 31 healthy controls (HC). When recruiting PD and MSA, questionnaires were conducted on motor and non-motor functions, such as autonomic and cognitive functions. Participants underwent CCM to quantify the corneal nerve fibers. Corneal nerve fiber density (CNFD) and corneal nerve fiber length (CNFL) values in MSA are lower than PD (MSA vs. PD: CNFD, 20.68 ± 6.70 vs. 24.64 ± 6.43 no./mm2, p < 0.05; CNFL, 12.01 ± 3.25 vs. 14.17 ± 3.52 no./mm2, p < 0.05). In MSA + PD (combined), there is a negative correlation between CNFD and the Orthostatic Grading Scale (OGS) (r = -0.284, p = 0.007). Similarly, CNFD in the only MSA group was negatively correlated with the Unified Multiple System Atrophy Rating Scale I and II (r = -0.391, p = 0.044; r = -0.382, p = 0.049). CNFD and CNFL were inversely associated with MSA (CNFD: ß = -0.071; OR, 0.932; 95% CI, 0.872 ~ 0.996; p = 0.038; CNFL: ß = -0.135; OR, 0.874; 95% CI, 0.768-0.994; p = 0.040). Furthermore, we found the area under the receiver operating characteristic curve (ROC) of CNFL was the largest, 72.01%. The CCM could be an objective and sensitive biomarker to distinguish MSA from PD. It visually reflects a more severe degeneration in MSA compared to PD.

Relationship between increased serum neurofilament light chain and glial fibrillary acidic protein levels with non-motor symptoms in patients with Parkinson's disease.

BACKGROUND: This study set out to investigate the relationship between serum neurofilament light chain (NFL), glial fibrillary acidic protein (GFAP), and various non-motor symptoms (NMSs) in patients with Parkinson's disease (PD). METHODS: The study included 37 healthy controls (HCs) and 51 PD patients. Clinical assessments of PD symptoms were conducted for all PD patients. The NMSS was utilised to evaluate the NMS burden (NMSB) in individuals. Based on the severity of NMSB, we further categorised the PD group into two subgroups: mild-moderate NMSB group and severe-very severe NMSB group. The amounts of NFL and GFAP in the serum were measured using an extremely sensitive single molecule array (Simoa) method. Statistical analyses were performed on the collected data using SPSS 26.0 and R (version 3.6.3). RESULTS: Serum GFAP and NFL levels in the PD group with severe-very severe NMSB were significantly higher than those in the mild-moderate NMSB group (GFAP: P < 0.007; NFL: P < 0.009). Serum NFL and GFAP levels had positive correlations with NMSS total scores (GFAP: r = 0.326, P = 0.020; NFL: r = 0.318, P = 0.023) and multiple subdomains. The relationship between the attention/memory domains of NMSS and NFL levels is significantly positive (r = 0.283, P = 0.044). Similarly, the mood/apathy domains of NMSS are also significantly positively correlated with GFAP levels (r = 0.441, P = 0.001). Patients with emotional problems or cognitive impairment had higher GFAP or NFL levels, respectively. Furthermore, it has been demonstrated that NMSs play a mediating role in the quality of life of patients with PD. Moreover, the combination of NFL and GFAP has proven to be more effective than using a single component in identifying PD patients with severe-very severe NMSB. CONCLUSIONS: The severity of NMSs in PD patients, particularly cognitive and emotional symptoms, was found to be associated with the levels of serum NFL and GFAP. This study marks the first attempt to examine the connection between NMSs of PD and the simultaneous identification of NFL and GFAP levels.

Effects of different concentrations of intraluminal sodium chloride solution on intracavitary ECG used for arm infusion port implantation.

At present, there are few clinical studies on the application of high-concentration sodium chloride solutions in intracavitary ECG-guided catheter tip localization during the arm infusion port implantation. This study observed the effects of sodium chloride solutions with different concentrations on intracavitary ECG-guided arm infusion port implantation in the patients with cancer. The 657 patients receiving arm infusion port implantation in our hospital between January 2020 and August 2021 were randomly divided into 0.9% sodium chloride solution conduction group (group A), 5.45% sodium chloride solution conduction group (group B) and 10% sodium chloride solution conduction group (group C). The derived rate of stable intracavitary ECG, the occurrence rate of characteristic P wave, the time used for catheter tip localization and the optimal position rate of catheter tip were compared between the three groups. The derived rate of stable intracavitary ECG was significantly higher in the group B (97.78%) and group C (98.63%) than in the group A (93.90%) (all P < 0.05). The occurrence rate of characteristic P wave was also significantly higher in the group B (96.89%) and group C (97.72%) than in the group A (88.73%) (all P < 0.001). The time used for catheter tip localization was significantly shorter in the group B [(49.73 ± 8.15) s] and group C [(48.27 ± 8.61) s] than in the group A [(69.37 ± 19.99) s] (all P < 0.001). There was no significant difference in the optimal position rate of catheter tip among the three groups (P > 0.05). The 5.45% and 10% sodium chloride solutions are significantly superior comparing with 0.9% sodium chloride solution in the derived rate of stable intracavitary ECG, occurrence rate of characteristic P wave and time used for catheter tip localization, but there were no significant differences between 5.45 and 10% sodium chloride solutions. Moreover, the 5.45% sodium chloride solution is closer to physiological state comparing with 10% sodium chloride solution, so the 5.45% sodium chloride solution may be recommended for the intracavitary ECG-guided arm infusion port implantation.

Vps33B controls Treg cell suppressive function through inhibiting lysosomal nutrient sensing complex-mediated mTORC1 activation.

The suppressive function of regulatory T (Treg) cells is tightly controlled by nutrient-fueled mechanistic target of rapamycin complex 1 (mTORC1) activation, yet its dynamics and negative regulation remain unclear. Here we show that Treg-specific depletion of vacuolar protein sorting 33B (Vps33B) in mice results in defective Treg cell suppressive function and acquisition of effector phenotype, which in turn leads to disturbed T cell homeostasis and boosted antitumor immunity. Mechanistically, Vps33B binds with lysosomal nutrient-sensing complex (LYNUS) and promotes late endosome and lysosome fusion and clearance of the LYNUS-containing late endosome/lysosome, and therefore suppresses mTORC1 activation. Vps33B deficiency in Treg cells results in disordered endosome lysosome fusion, which leads to accumulation of LYNUS that causes elevated mTORC1 activation and hyper-glycolytic metabolism. Taken together, our study reveals that Vps33B maintains Treg cell suppressive function through sustaining endolysosomal homeostasis and therefore restricting amino acid-licensed mTORC1 activation and metabolism.

Ubc13 Promotes K63-Linked Polyubiquitination of NLRP3 to Activate Inflammasome.

NLRP3 inflammasome plays an important role in innate immune system through recognizing pathogenic microorganisms and danger-associated molecules. Deubiquitination of NLRP3 has been shown to be essential for its activation, yet the functions of Ubc13, the K63-linked specific ubiquitin-conjugating enzyme E2, in NLRP3 inflammasome activation are not known. In this study, we found that in mouse macrophages, Ubc13 knockdown or knockout dramatically impaired NLRP3 inflammasome activation. Catalytic activity is required for Ubc13 to control NLRP3 activation, and Ubc13 pharmacological inhibitor significantly attenuates NLRP3 inflammasome activation. Mechanistically, Ubc13 associates with NLRP3 and promotes its K63-linked polyubiquitination. Through mass spectrum and biochemical analysis, we identified lysine 565 and lysine 687 as theK63-linked polyubiquitination sites of NLRP3. Collectively, our data suggest that Ubc13 potentiates NLRP3 inflammasome activation via promoting site-specific K63-linked ubiquitination of NLRP3. Our study sheds light on mechanisms of NLRP3 inflammasome activation and identifies that targeting Ubc13 could be an effective therapeutic strategy for treating aberrant NLRP3 inflammasome activation-induced pathogenesis.

SIRT3-mediated deacetylation of NLRC4 promotes inflammasome activation.

Salmonella typhimurium (S. typhimurium) infection of macrophage induces NLRC4 inflammasome-mediated production of the pro-inflammatory cytokines IL-1ß. Post-translational modifications on NLRC4 are critical for its activation. Sirtuin3 (SIRT3) is the most thoroughly studied mitochondrial nicotinamide adenine dinucleotide (NAD+) -dependent deacetylase. We wondered whether SIRT3 mediated-deacetylation could take part in NLRC4 inflammasome activation. Methods: We initially tested IL-1ß production and pyroptosis after cytosolic transfection of flagellin or S. typhimurium infection in wild type and SIRT3-deficient primary peritoneal macrophages via immunoblotting and ELISA assay. These results were confirmed in SIRT3-deficient immortalized bone marrow derived macrophages (iBMDMs) which were generated by CRISPR-Cas9 technology. In addition, in vivo experiments were conducted to confirm the role of SIRT3 in S. typhimurium-induced cytokines production. Then NLRC4 assembly was analyzed by immune-fluorescence assay and ASC oligomerization assay. Immunoblotting, ELISA and flow cytometry were performed to clarify the role of SIRT3 in NLRP3 and AIM2 inflammasomes activation. To further investigate the mechanism of SIRT3 in NLRC4 activation, co-immunoprecipitation (Co-IP), we did immunoblot, cellular fractionation and in-vitro deacetylation assay. Finally, to clarify the acetylation sites of NLRC4, we performed liquid chromatography-mass spectrometry (LC-MS) and immunoblotting analysis. Results: SIRT3 deficiency led to significantly impaired NLRC4 inflammasome activation and pyroptosis both in vitro and in vivo. Furthermore, SIRT3 promotes NLRC4 inflammasome assembly by inducing more ASC speck formation and ASC oligomerization. However, SIRT3 is dispensable for NLRP3 and AIM2 inflammasome activation. Moreover, SIRT3 interacts with and deacetylates NLRC4 to promote its activation. Finally, we proved that deacetylation of NLRC4 at Lys71 or Lys272 could promote its activation. Conclusions: Our study reveals that SIRT3 mediated-deacetylation of NLRC4 is pivotal for NLRC4 activation and the acetylation switch of NLRC4 may aid the clearance of S. typhimurium infection.