Curcumin Inhibits α-Synuclein Aggregation by Acting on Liquid-Liquid Phase Transition.

Parkinson's disease (PD), the second most common neurodegenerative disorder, is linked to α-synuclein (α-Syn) aggregation. Despite no specific drug being available for its treatment, curcumin, from the spice turmeric, shows promise. However, its application in PD is limited by a lack of understanding of its anti-amyloidogenic mechanisms. In this study, we first reconstructed the liquid-liquid phase separation (LLPS) of α-Syn in vitro under different conditions, which may be an initial step in entraining the pathogenic aggregation. Subsequently, we evaluated the effects of curcumin on the formation of droplets, oligomers, and aggregated fibers during the LLPS of α-synuclein, as well as its impact on the toxicity of aggregated α-synuclein to cultured cells. Importantly, we found that curcumin can inhibit amyloid formation by inhibiting the occurrence of LLPS and the subsequent formation of oligomers of α-Syn in the early stages of aggregation. Finally, the molecular dynamic simulations of interactions between α-Syn decamer fibrils and curcumin showed that van der Waal's interactions make the largest contribution to the anti-aggregation effect of curcumin. These results may help to clarify the mechanism by which curcumin inhibits the formation of α-Syn aggregates during the development of PD.

Robotic-assisted proctosigmoidectomy for Hirschsprung's disease: A multicenter prospective study.

BACKGROUND: Robotic surgery is a cutting-edge minimally invasive technique that overcomes many shortcomings of laparoscopic techniques, yet few studies have evaluated the use of robotic surgery to treat Hirschsprung's disease (HSCR). AIM: To analyze the feasibility and medium-term outcomes of robotic-assisted proctosigmoidectomy (RAPS) with sphincter- and nerve-sparing surgery in HSCR patients. METHODS: From July 2015 to January 2022, 156 rectosigmoid HSCR patients were enrolled in this multicenter prospective study. Their sphincters and nerves were spared by dissecting the rectum completely from the pelvic cavity outside the longitudinal muscle of the rectum and then performing transanal Soave pull-through procedures. Surgical outcomes and continence function were analyzed. RESULTS: No conversions or intraoperative complications occurred. The median age at surgery was 9.50 months, and the length of the removed bowel was 15.50 ± 5.23 cm. The total operation time, console time, and anal traction time were 155.22 ± 16.77, 58.01 ± 7.71, and 45.28 ± 8.15 min. There were 25 complications within 30 d and 48 post-30-d complications. For children aged ≥ 4 years, the bowel function score (BFS) was 17.32 ± 2.63, and 90.91% of patients showed moderate-to-good bowel function. The postoperative fecal continence (POFC) score was 10.95 ± 1.04 at 4 years of age, 11.48 ± 0.72 at 5 years of age, and 11.94 ± 0.81 at 6 years of age, showing a promising annual trend. There were no significant differences in postoperative complications, BFS, and POFC scores related to age at surgery being ≤ 3 mo or > 3 mo. CONCLUSION: RAPS is a safe and effective alternative for treating HSCR in children of all ages; it offers the advantage of further minimizing damage to sphincters and perirectal nerves and thus providing better continence function.

Comparison of efficacy and safety of robotic surgery and laparoscopic surgery for choledochal cyst in children: a systematic review and proportional meta-analysis.

BACKGROUND: Most commonly, cyst excision and Roux-en-Y hepaticojejunostomy reconstruction are the optimal treatment for choledochal cysts (CC). Robotic surgery (RS) is being conducted with increasing frequency to treat CC. It is unclear whether RS can overcome the limitations of laparoscopic surgery (LS) and improve the prognosis of patients. In terms of efficacy, evidence concerning which minimally invasive surgery is preferred is, however, sparse. Our objective is to further compare the efficacy of RS and LS in children with CC and draw a useful clinical conclusion. METHODS: Studies meeting inclusion criteria were identified from a series of databases, consisting of PubMed, Embase, Scopus, Web of Science, the Cochrane Library and their reference list of articles up to May 2022. Eligible articles comprised at least five objects that were younger than 18 years of age and the language was limited to English. Two authors independently evaluated selected studies and extracted data for analysis. RESULTS: Forty studies were selected for analysis, with thirty-six reporting data on LS and eight containing data on RS. The pooled conversion rate and pooled postoperative complication rate of RS were lower than those of LS, but none of them was statistically significant. Moreover, comparisons of the following detailed postoperative complication rates were not statistically significant, such as intestinal obstruction or ileus, anastomotic bleeding, anastomotic or bile leakage, and anastomotic stenosis. However, the intraoperative blood loss and the postoperative hospital stay in RS group were significantly lower than those in LS group. CONCLUSIONS: RS is a safe and feasible option for children with CC. Further studies with more cases, long-term efficacy and health economics analysis are needed to confirm whether RS is more advantageous.

USP22 promotes IRF3 nuclear translocation and antiviral responses by deubiquitinating the importin protein KPNA2.

USP22 is a cytoplasmic and nuclear deubiquitinating enzyme, and the functions of cytoplasmic USP22 are unclear. Here, we discovered that cytoplasmic USP22 promoted nuclear translocation of IRF3 by deubiquitianting and stabilizing KPNA2 after viral infection. Viral infection induced USP22-IRF3 association in the cytoplasm in a KPNA2-depedent manner, and knockdown or knockout of USP22 or KPNA2 impaired IRF3 nuclear translocation and expression of downstream genes after viral infection. Consistently, Cre-ER Usp22fl/fl or Lyz2-Cre Usp22fl/fl mice produced decreased levels of type I IFNs after viral infection and exhibited increased susceptibility to lethal viral infection compared with the respective control littermates. Mechanistically, USP22 deubiquitinated and stabilized KPNA2 after viral infection to facilitate efficient nuclear translocation of IRF3. Reconstitution of KPNA2 into USP22 knockout cells restored virus-triggered nuclear translocation of IRF3 and cellular antiviral responses. These findings define a previously unknown function of cytoplasmic USP22 and establish a mechanistic link between USP22 and IRF3 nuclear translocation that expands potential therapeutic strategies for infectious diseases.

USP49 negatively regulates cellular antiviral responses via deconjugating K63-linked ubiquitination of MITA.

Mediator of IRF3 activation (MITA, also known as STING and ERIS) is an essential adaptor protein for cytoplasmic DNA-triggered signaling and involved in innate immune responses, autoimmunity and tumorigenesis. The activity of MITA is critically regulated by ubiquitination and deubiquitination. Here, we report that USP49 interacts with and deubiquitinates MITA after HSV-1 infection, thereby turning down cellular antiviral responses. Knockdown or knockout of USP49 potentiated HSV-1-, cytoplasmic DNA- or cGAMP-induced production of type I interferons (IFNs) and proinflammatory cytokines and impairs HSV-1 replication. Consistently, Usp49-/- mice exhibit resistance to lethal HSV-1 infection and attenuated HSV-1 replication compared to Usp49+/+ mice. Mechanistically, USP49 removes K63-linked ubiquitin chains from MITA after HSV-1 infection which inhibits the aggregation of MITA and the subsequent recruitment of TBK1 to the signaling complex. These findings suggest a critical role of USP49 in terminating innate antiviral responses and provide insights into the complex regulatory mechanisms of MITA activation.

USP20 Promotes Cellular Antiviral Responses via Deconjugating K48-Linked Ubiquitination of MITA.

Mediator of IRF3 activation ([MITA] also known as STING) is a direct sensor of cyclic dinucleotide and critically mediates cytoplasmic DNA--triggered innate immune signaling. The activity of MITA is extensively regulated by ubiquitination and deubiquitination. In this study, we report that USP20 interacts with and removes K48-linked ubiquitin chains from MITA after HSV-1 infection, thereby stabilizing MITA and promoting cellular antiviral responses. Deletion of USP20 accelerates HSV-1-induced degradation of MITA and impairs phosphorylation of IRF3 and IκBα as well as subsequent induction of type I IFNs and proinflammatory cytokines after HSV-1 infection or cytoplasmic DNA challenge. Consistently, Usp20 -/- mice produce decreased type I IFNs and proinflammatory cytokines, exhibit increased susceptibility to lethal HSV-1 infection, and aggravated HSV-1 replication compared with Usp20 +/+ mice. In addition, complement of MITA into Usp20 -/- cells fully restores HSV-1-triggered signaling and inhibits HSV-1 infection. These findings suggest a crucial role of USP20 in maintaining the stability of MITA and promoting innate antiviral signaling.

USP18 recruits USP20 to promote innate antiviral response through deubiquitinating STING/MITA.

STING (also known as MITA) mediates the innate antiviral signaling and ubiquitination of STING is key to its function. However, the deubiquitination process of STING is unclear. Here we report that USP18 recruits USP20 to deconjugate K48-linked ubiquitination chains from STING and promotes the stability of STING and the expression of type I IFNs and proinflammatory cytokines after DNA virus infection. USP18 deficiency or knockdown of USP20 resulted in enhanced K48-linked ubiquitination and accelerated degradation of STING, and impaired activation of IRF3 and NF-κB as well as induction of downstream genes after infection with DNA virus HSV-1 or transfection of various DNA ligands. In addition, Usp18-/- mice were more susceptible to HSV-1 infection compared with the wild-type littermates. USP18 did not deubiquitinate STING in vitro but facilitated USP20 to catalyze deubiquitination of STING in a manner independent of the enzymatic activity of USP18. In addition, reconstitution of STING into Usp18-/- MEFs restored HSV-1-induced expression of downstream genes and cellular antiviral responses. Our findings thus uncover previously uncharacterized roles of USP18 and USP20 in mediating virus-triggered signaling and contribute to the understanding of the complicated regulatory system of the innate antiviral responses.

Induction of USP25 by viral infection promotes innate antiviral responses by mediating the stabilization of TRAF3 and TRAF6.

Host pathogen-recognition receptors detect nucleic acid from invading viruses and initiate a series of signaling pathways that lead to the production of type I interferons (IFNs) and proinflammatory cytokines. Here, we found that a viral infection-induced deubiquitinase (DUB), ubiquitin-specific protease 25 (USP25) was required for host defense against RNA and DNA viruses. The activation of transcription factors IRF3 and NF-κB was impaired and the production of type I IFNs and proinflammatory cytokines was inhibited in Usp25-/- cells compared with the wild-type counterparts after RNA or DNA viruses infection. Consistently, USP25 deficient mice were more susceptible to H5N1 or HSV-1 infection compared with the wild-type mice. USP25 was associated with TRAF3 and TRAF6 after infection by RNA or DNA viruses and protected virus-induced proteasome-dependent or independent degradation of TRAF3 and TRAF6, respectively. Moreover, reconstitution of TRAF3 and TRAF6 into Usp25-/- MEFs restored virus-triggered production of type I IFNs and proinflammatory cytokines. Our findings thus reveal a previously uncovered positive feedback regulation of innate immune responses against RNA and DNA viruses by USP25.

[Electroluminescent device based on rare earth terbium complex].

Rare earth complex TbY(m-MBA)6 (phen)2.2H20 have been synthesized, which were used as emitting materials in electroluminescence. Single-layer devices and bilayer devices with Alq as electron transmission layer have been fabricated. The electroluminescent properties of the devices were studied. The electroluminescent mechanism of the devices was proposed by measuring and analyzing the emission and the excitation spectra of the emissive layer. Y3+ may play the role to promote the energy transfer from ligand to Tb3+ and the possible energy transfer process of the device was preliminarily discussed.

[Emission mechanism in the Tb complex doped PVK system].

Excitation and photoluminescence (PL) spectra of the mixture terbium complex and PVK were investigated. The excitation spectrum of Tb complex dispersed PVK film is very similar to that of the pure PVK film, indicting that energy transfer occurs from PVK to Tb complex. For the overlap between the excitation spectrum of Tb complex dispersed PVK film and the PL spectrum of PVK film is very little, the ratio of occurrence for Förester energy transfer is very little. The emission of Tb3+ mainly comes from the excited ligand, which comes from the ligand capture of electron-hole pairs. In the electroluminescence (EL) spectra, the emission of PVK is completely restrained and only emission of Tb3+ is occured, which origins from the different mechanism in comparison with photoluminescence.