Differences in ingestion and biodegradation of the melamine formaldehyde plastic by yellow mealworms Tenebrio molitor and superworms Zophobas atratus, and the prediction of functional gut microbes.

Plastics biodegradation by insect larvae is considered as a new strategy for plastic wastes treatment. To uncover the biodegradation of a more complex chemical polymer of melamine formaldehyde (MF) by insect larvae, two worm species of yellow mealworm Tenebrio molitor and superworm Zophobas atratus were fed on MF foam as sole diet for 45 days with sole bran diet as control. Although the MF foam consumption by yellow mealworms of 0.38 mg/d/g-larvae was almost 40% higher than that by superworms of 0.28 mg/d/g-larvae, a similar decrease of survival rates in both species were obtained at about 58%, indicating the adverse effects on their growth. Depolymerization and biodegradation of MF foam occurred in both larval guts, but was more extensive in yellow mealworms. MF foam sole diet influenced gut bacterial and fungal microbiomes of both larvae species, which were assessed by Illumina MiSeq on day 45. Compared to the bran-fed group, both gut bacterial and fungal communities significantly changed in MF-fed groups, but differed in the two larvae species. The results demonstrated a strong association between the distinctive gut microbiome and MF foam degradation, such as unclassified Enterobacteriaceae, Hyphopichia and Issatchenkia. However, sole MF foam diet negatively influenced worms, like lower survival rates and gut abnormalities. In summary, MF foam could be degraded by both yellow mealworms and superworms, albeit with adverse effects. Gut microbes were strongly associated to MF foam degradation, especially the gut fungi.

Risk factors associated with age at onset of Parkinson's disease in the UK Biobank.

Substantial evidence shown that the age at onset (AAO) of Parkinson's disease (PD) is a major determinant of clinical heterogeneity. However, the mechanisms underlying heterogeneity in the AAO remain unclear. To investigate the risk factors with the AAO of PD, a total of 3156 patients with PD from the UK Biobank were included in this study. We evaluated the effects of polygenic risk scores (PRS), nongenetic risk factors, and their interaction on the AAO using Mann-Whitney U tests and regression analyses. We further identified the genes interacting with nongenetic risk factors for the AAO using genome-wide environment interaction studies. We newly found physical activity (P < 0.0001) was positively associated with AAO and excessive daytime sleepiness (P < 0.0001) was negatively associated with AAO, and reproduced the positive associations of smoking and non-steroidal anti-inflammatory drug intake and the negative association of family history with AAO. In the dose-dependent analyses, smoking duration (P = 1.95 × 10-6), coffee consumption (P = 0.0150), and tea consumption (P = 0.0008) were positively associated with AAO. Individuals with higher PRS had younger AAO (P = 3.91 × 10-5). In addition, we observed a significant interaction between the PRS and smoking for AAO (P = 0.0316). Specifically, several genes, including ANGPT1 (P = 7.17 × 10-7) and PLEKHA6 (P = 4.87 × 10-6), may influence the positive relationship between smoking and AAO. Our data suggests that genetic and nongenetic risk factors are associated with the AAO of PD and that there is an interaction between the two.

Identifying Network Biomarkers in Early Diagnosis of Hepatocellular Carcinoma via miRNA-Gene Interaction Network Analysis.

BACKGROUND: Hepatocellular carcinoma (HCC) is a highly heterogeneous cancer at the histological level. Despite the emergence of new biological technology, advanced-stage HCC remains largely incurable. The prediction of a cancer biomarker is a key problem for targeted therapy in the disease. METHODS: We performed a miRNA-gene integrated analysis to identify differentially expressed miRNAs (DEMs) and genes (DEGs) of HCC. The DEM-DEG interaction network was constructed and analyzed. Gene ontology enrichment and survival analyses were also performed in this study. RESULTS: By the analysis of healthy and tumor samples, we found that 94 DEGs and 25 DEMs were significantly differentially expressed in different datasets. Gene ontology enrichment analysis showed that these 94 DEGs were significantly enriched in the term "Liver" with a statistical p-value of 1.71 × 10-26. Function enrichment analysis indicated that these genes were significantly overrepresented in the term "monocarboxylic acid metabolic process" with a p-value = 2.94 × 10-18. Two sets (fourteen genes and five miRNAs) were screened by a miRNA-gene integrated analysis of their interaction network. The statistical analysis of these molecules showed that five genes (CLEC4G, GLS2, H2AFZ, STMN1, TUBA1B) and two miRNAs (hsa-miR-326 and has-miR-331-5p) have significant effects on the survival prognosis of patients. CONCLUSION: We believe that our study could provide critical clinical biomarkers for the targeted therapy of HCC.

Bone Marrow Stromal Cell-Secreted Extracellular Vesicles Containing miR-34c-5p Alleviate Lung Injury and Inflammation in Bronchopulmonary Dysplasia Through Promotion of PTEN Degradation by Targeting OTUD3.

BACKGROUND: Bronchopulmonary dysplasia (BPD) is the predominant chronic disorder in preterm neonates. This study explored impacts of miR-34c-5p carried by bone marrow stromal cells-secreted extracellular vesicles (BMSC-EVs) on BPD progression. METHODS: A BPD mouse model was established, followed by measurement of miR-34c-5p, OTUD3, and PTEN expression. EVs were isolated from BMSCs transfected with miR-34c-5p mimic or mimic NC and intratracheally injected into mice. CD31 and Ki67 expression was detected and the pathological changes of lung tissues and lung function indexes were observed for mice. A neonatal human pulmonary microvascular endothelial cell (HPMEC) model was developed with hyperoxia, followed by co-culture with extracted EVs and ectopic experiments for measurement of cell viability, migration, and angiogenesis. IL-4, IL-13, IL-1ß, and IL-6 levels were measured in cell supernatants and lung tissues. Dual-luciferase reporter, ubiquitination, Co-IP, and RIP assays were adopted to determine the relationship among miR-34c-5p, OTUD3, and PTEN. RESULTS: Lung tissues of BPD mice had downregulated miR-34c-5p expression and upregulated OTUD3 and PTEN expression. BMSC-EVs and BMSC-EVs-miR-34c-5p treatment improved lung injury and alveolar structure, decreased lung resistance and IL-4, IL-13, IL-1ß, and IL-6 levels, and elevated dynamic lung compliance in BPD mice, as well as enhanced proliferation, angiogenesis, and migration and restrained inflammation in HPMECs. Mechanistically, miR-34c-5p negatively targeted OTUD3 which restrained ubiquitination to promote PTEN protein stabilization. Upregulation of OTUD3 or PTEN negated the changes in the proliferation, angiogenesis, migration, and inflammation of hyperoxia-treated HPMECs induced by BMSC-EVs-miR-34c-5p. CONCLUSION: BMSC-EVs-miR-34c-5p alleviated lung injury and inflammation in hyperoxia-induced BPD by blocking the OTUD3/PTEN axis.

Therapeutic Role and Potential Mechanism of Resveratrol in Atherosclerosis: TLR4/NF-κB/HIF-1α.

Atherosclerosis, the main pathological basis of cardiovascular disease, is a chronic inflammatory disease that severely affects the quality of human life. Resveratrol (Res) is a natural polyphenol that is a major component of many herbs and foods. The present study analyzed resveratrol from the perspective of visualization and bibliometric analysis and found that resveratrol is closely related to the inflammatory response in cardiovascular diseases (associated with atherosclerosis). To explore the specific molecular mechanism of resveratrol, network pharmacology and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used, in which HIF-1α signaling may be a key pathway in the treatment of AS. Furthermore, we induced the polarization of macrophage RAW264.7 to M1 type to generate inflammatory response by the combination of lipopolysaccharide (LPS) (200 ng/mL) + interferon-γ (IFN-γ) (2.5 ng/mL). LPS and IFN-γ increased the inflammatory factor levels of IL-1ß, TNF-α, and IL-6 in RAW264.7, and the proportion of M1-type macrophages also increased, but the expression of inflammatory factors decreased after resveratrol administration, which confirmed the anti-inflammatory effect of resveratrol in AS. In addition, we found that resveratrol downregulated the protein expression of toll-like receptor 4 (TLR4)/NF-κB/hypoxia inducible factor-1 alpha (HIF-1α). In conclusion, resveratrol has a significant anti-inflammatory effect, alleviates HIF-1α-mediated angiogenesis, and prevents the progression of AS through the TLR4/NF-κB signaling pathway.

Basic and clinical study of efficacy and adverse effects of flumatinib in Ph+ ALL.

Objective: To investigate the efficacy and safety of chemotherapy in treating Ph+ ALL based on flumatinib. Methods: The clinical data of 29 patients with Ph+ ALL receiving flumatinib-based chemotherapy in Sichuan Provincial People's Hospital from January 2020 to January 2023 were collected for analysis, with the concentrations of TKI in the peripheral blood, bone marrow, and cerebrospinal fluid of some patients monitored, Cytological experiments on SUP-B15 were conducted in a Ph+ ALL cell line. Results: A total of 29 patients were enrolled, showing the induced CR, 3-month CR, and 6-month CR rates of 96.3%, 87.5%, and 86.7%, respectively after flumatinib-based chemotherapy. The negative conversion ratio of MRD was 82.6%, 91.3%, and 95.6% in 1, 2, and 3 months after treatment, respectively, with 4.3% of patients failing the conversion in 3 months after treatment. The rates of MMR were 73.9%, 87.5%, and 93.3% in 1, 3, and 6 months after treatment, and CMR of 52.2%, 62.5%, and 73.3%, respectively. Among the 29 patients, 11 (37.9%) received transplant and the continuous flumatinib for 1 year after transplantation. The deep remission was maintained in all patients up to the time of follow-up, with the median follow-up of 12 months (1-33 months), progression-free survival (PFS) of 11 months (1-33 months), and median overall survival (OS) of 12 months (1-33 months). The adverse reactions mainly referred to myelosuppression, liver insufficiency and infection that were generally tolerable. In terms of blood concentration, the concentration of flumatinib was ordered as bone marrow > serum > cerebrospinal fluid in Ph+ ALL bone marrow. In contrast, the concentration of dasatinib and imatinib was ordered as serum > bone marrow > cerebrospinal fluid. At the same time, flumatinib has a high probability to cross the blood-brain barrier, while the concentration of cerebrospinal fluid in the patients using Dasatinib was lower compared to the lower limit of detection in this study. Compared with Imatinib and Dasatinib, flumatinib exerted the most potent inhibitory effect on Ph+ ALL cell lines according to pharmacodynamic analysis of SUP-B15 cells. Conclusion: Flumatinib combined with chemotherapy could achieve good efficacy and safety in treating Ph+ ALL, with flumatinib in a high probability of crossing the blood-brain barrier. Flumatinib could be a superior choice to Dasatinib and Imatinib in cell experiments.

A DNA Damage Response Related Signature to Predict Prognosis in Patients with Acute Myeloid Leukemia.

The prognosis of acute myeloid leukemia (AML) is disappointing in most subtypes and varies widely. DNA damage response (DDR) is associated with prognosis and immunotherapy in multiple cancers. Here, we identify a signature of eight DDR-related genes associated with overall survival, which stratifies AML patients into high- and low-risk groups. Patients in low-risk group were more likely to respond to sorafenib. The signature could be an independent prognostic predictor for patients treated with ADE and ADE plus gemtuzumab ozogamicin. Therefore, this DDR prognostic signature might be applied to prognostic stratification and treatment selection in AML patients, which warrants further studies.

Heterojunction structured BiOCl-Bi2S3 nanosheets as mitochondria-targeted near-infrared photothermal and photodynamic therapy agent.

Mitochondria-targeted phototherapy, especially combined photothermal therapy (PTT) and photodynamic therapy (PDT), has been regarded as an attractive strategy for the treatment of tumor. In this study, a facile approach to prepare two-dimensional (2D) BiOCl-Bi2S3 nanostructures was developed, where Bi2S3 quantum dots were doped in/on the ultrathin BiOCl nanosheets, forming a p-n heterojunction. The BiOCl-Bi2S3 shows favorable photothermal conversion efficiency (32%) and synergistically reactive oxygen species (ROS) generating capability under near-infrared (NIR) irradiation. Moreover, the conjugation of synthetic targeting ligand to the surface of BiOCl-Bi2S3 endows the heterojunction effective tumor targeting ability and selective mitochondrial accumulation. The combined cancer targeting ability and synergistic PTT/PDT permit enhanced cooperative phototherapeutic efficiency of the 2D heterojunction. This study provides an attractive way for designing new class of heterostructure materials for potential applications in subcellular-targeted phototherapy.

Dioxygen Activation and Nδ,Nε-Dihydroxylation Mechanism Involved in the Formation of N-Nitrosourea Pharmacophore in Streptozotocin Catalyzed by Nonheme Diiron Enzyme SznF.

SznF is a nonheme diiron-dependent enzyme that catalyzes the critical N-nitrosation involved in the formation of the N-nitrosourea moiety in the pancreatic cancer drug streptozotocin. The N-nitrosation contains two successive N-hydroxylation and N-nitrosation steps, which are carried out by two separate active sites, namely, the central domain and cupin domain. Recently, the crystal structure of SznF was obtained, and the central domain was proved to contain a diiron cofactor to catalyze the N-hydroxylation. In this work, to gain insights into the O2 activation and the successive N-hydroxylation mechanism, on the basis of the high-resolution crystal structure, the enzyme-substrate complex models were constructed, and a series of combined QM/MM calculations were performed. Based on our calculations, the activation of O2 starts from the diiron(II,III)-superoxo (S) to generate the diiron(IV)-oxo species (Q) via a diiron(III,III)-peroxo (P)-like transition state or unstable intermediate (P'), and species P' can be described as a hybridization of diiron(IV)-oxo species and diiron(III,III)-peroxo (P) owing to the long distances of Fe1-Fe2 (4.22 Å) and O1-O2 (1.89 Å), which is different from those of other nonheme diiron enzymes. In the following hydroxylation of Nδ and Nε, the Nδ-hydroxylation was confirmed to occur first, agreeing with the experimental observations. Because the diiron(IV)-oxo species (Q) is responsible for hydroxylation, the reaction follows the H-abstraction/OH rebound mechanism, and the first abstraction occurs on the Nδ-H rather than Nε-H, which may be attributed to the different orientation of Fe(IV)-oxo relative to N-H as well as the bond dissociation enthalpies of two N-H bonds. The hydroxylation of N-methyl-L-arginine does not employ the diiron(III,III)-hydroperoxo (P″) to trigger the electrophilic attack of the guanidine to directly form the N-O bond, as previously suggested. In addition, our calculations also revealed that the direct attack of the Fe(IV)═O unit to the Nδ of the substrate corresponds to a higher barrier than that in the H-abstraction/OH rebound mechanism. These results may provide useful information for understanding the formation of the di-hydroxylation intermediate involved in the biosynthesis of N-nitrosation.

USP10 as a Potential Therapeutic Target in Human Cancers.

Deubiquitination is a major form of post-translational protein modification involved in the regulation of protein homeostasis and various cellular processes. Deubiquitinating enzymes (DUBs), comprising about five subfamily members, are key players in deubiquitination. USP10 is a USP-family DUB featuring the classic USP domain, which performs deubiquitination. Emerging evidence has demonstrated that USP10 is a double-edged sword in human cancers. However, the precise molecular mechanisms underlying its different effects in tumorigenesis remain elusive. A possible reason is dependence on the cell context. In this review, we summarize the downstream substrates and upstream regulators of USP10 as well as its dual role as an oncogene and tumor suppressor in various human cancers. Furthermore, we summarize multiple pharmacological USP10 inhibitors, including small-molecule inhibitors, such as spautin-1, and traditional Chinese medicines. Taken together, the development of specific and efficient USP10 inhibitors based on USP10's oncogenic role and for different cancer types could be a promising therapeutic strategy.

Circular RNA sterile alpha motif domain containing 4A contributes to cell 5-fluorouracil resistance in colorectal cancer by regulating the miR-545-3p/6-phosphofructo-2-kinase/fructose-2,6-bisphosphataseisotype 3 axis.

Colorectal cancer (CRC) is one of the most fatal cancers in the world. Circular RNA sterile alpha motif domain containing 4A (circSAMD4A) was found to be highly expressed in CRC and promoted the tumorigenesis of CRC. However, the role of circSAMD4A in 5-fluorouracil (5-Fu) resistance of CRC is yet to be clarified. This study is designed to investigate the function of circSAMD4A in 5-Fu resistance of CRC and its potential molecular mechanism. Quantitative real-time PCR was used to detect the expression levels of circSAMD4A, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase isotype 3 (PFKFB3) mRNA, and miR-545-3p, and western blot was used to detect the protein expression. For functional analysis, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay, colony formation/5-ethynyl-2'-deoxyuridine assay, flow cytometry analysis, and glycolysis metabolism analysis were used to assess the capacities of cell viability, proliferation, apoptosis, and glycolysis in 5-Fu-resistant cells of CRC. The dual-luciferase reporter assay was used to verify the interaction between miR-545-3p and circSAMD4A or PFKFB3. Xenograft tumor model was established to confirm the biological role of circSAMD4A in 5-Fu resistance of CRC in vivo. CircSAMD4A was upregulated in 5-Fu-resistant CRC tissues and cells. Functionally, circSAMD4A knockdown inhibited the proliferation and glycolysis mechanism but promoted apoptosis in 5-Fu-resistant cells of CRC. CircSAMD4A was identified as a molecular sponge of miR-545-3p to upregulate PFKFB3 expression. Mechanistically, circSAMD4A knockdown-induced 5-Fu sensitivity was mediated by miR-545-3p/PFKFB3 axis. Moreover, circSAMD4A knockdown improved 5-Fu sensitivity of CRC in vivo. CircSAMD4A contributed to 5-Fu resistance of CRC cells partly through upregulating PFKFB3 expression by sponging miR-545-3p, providing a possible circRNA-targeted therapy for CRC.

Performance comparison of computational methods for the prediction of the function and pathogenicity of non-coding variants.

Non-coding variants in the human genome significantly influence human traits and complex diseases via their regulation and modification effects. Hence, an increasing number of computational methods are developed to predict the effects of variants in human non-coding sequences. However, it is difficult for inexperienced users to select appropriate computational methods from dozens of available methods. To solve this issue, we assessed 12 performance metrics of 24 methods on four independent non-coding variant benchmark datasets: (1) rare germline variants from clinical relevant sequence variants (ClinVar), (2) rare somatic variants from catalogue of somatic mutations in cancer (COSMIC), (3) common regulatory variants from curated expression quantitative trait loci (eQTL) data, and (4) disease-associated common variants from curated genome-wide association studies (GWAS). All 24 tested methods performed differently under various conditions, indicating varying strengths and weaknesses under different scenarios. Importantly, the performance of existing methods was acceptable for rare germline variants from ClinVar with the area under the curve (AUC) of 0.4481-0.8033 and poor for rare somatic variants from COSMIC (AUC: 0.4984-0.7131), common regulatory variants from curated eQTL data (AUC: 0.4837-0.6472), and disease-associated common variants from curated GWAS (AUC: 0.4766-0.5188). We also compared the prediction performance of 24 methods for non-coding de novo mutations in autism spectrum disorder and found that the combined annotation-dependent depletion (CADD) and context-dependent tolerance score (CDTS) methods showed better performance. Summarily, we assessed the performance of 24 computational methods under diverse scenarios, providing preliminary advice for proper tool selection, guiding the development of new techniques in interpreting non-coding variants.

Tankyrase-1-mediated degradation of Golgin45 regulates glycosyltransferase trafficking and protein glycosylation in Rab2-GTP-dependent manner.

Altered glycosylation plays an important role during development and is also a hallmark of increased tumorigenicity and metastatic potentials of several cancers. We report here that Tankyrase-1 (TNKS1) controls protein glycosylation by Poly-ADP-ribosylation (PARylation) of a Golgi structural protein, Golgin45, at the Golgi. TNKS1 is a Golgi-localized peripheral membrane protein that plays various roles throughout the cell, ranging from telomere maintenance to Glut4 trafficking. Our study indicates that TNKS1 localization to the Golgi apparatus is mediated by Golgin45. TNKS1-dependent control of Golgin45 protein stability influences protein glycosylation, as shown by Glycomic analysis. Further, FRAP experiments indicated that Golgin45 protein level modulates Golgi glycosyltransferease trafficking in Rab2-GTP-dependent manner. Taken together, these results suggest that TNKS1-dependent regulation of Golgin45 may provide a molecular underpinning for altered glycosylation at the Golgi during development or oncogenic transformation.

The selective NLRP3 inhibitor MCC950 hinders atherosclerosis development by attenuating inflammation and pyroptosis in macrophages.

NLRP3 inflammasome is a vital player in macrophages pyroptosis, which is a type of proinflammatory cell-death and takes part in the pathogenesis of atherosclerosis. In this study, we used apoE-/- mice and ox-LDL induced THP-1 derived macrophages to explore the mechanisms of MCC950, a selective NLRP3 inhibitor in treating atherosclerosis. For the in vivo study, MCC950 was intraperitoneal injected to 8-week-old apoE-/- mice fed with high-fat diet for 12 weeks. For the in vitro study, THP-1 derived macrophages were treated with ox-LDL and MCC950 for 48 h. MCC950 administration reduced plaque areas and macrophages contents, but did not improve the serum lipid profiles in aortic root of apoE-/- mice. MCC950 inhibited the activation of NLRP3/ASC/Caspase-1/GSDMD-N axis, and alleviated macrophages pyroptosis and the production of IL-1ß and IL-18 both in aorta and in cell lysates. However, MCC950 did not affect the expression of TLR4 or the mRNA levels of NLRP3 inflammasome and its downstream proteins, suggesting that MCC950 had no effects on the priming of NLRP3 inflammasome activation in macrophages. The anti-atherosclerotic mechanisms of MCC950 on attenuating macrophages inflammation and pyroptosis involved in inhibiting the assembly and activation of NLRP3 inflammasome, rather than interrupting its priming.

Antimicrobial photodynamic therapeutic effects of cationic amino acid-porphyrin conjugate 4i on Porphyromonas gingivalis in vitro.

BACKGROUND: Porphyromonas gingivalis (P. gingivalis) is considered to be among the principal pathogens in periodontal disease. The present study aimed to investigate the effect of antimicrobial photodynamic therapy (aPDT) mediated by cationic amino acid-porphyrin conjugate 4i on P. gingivalis METHODS: The uptake of 4i by P. gingivalis over different times of incubation was evaluated by optical density using a microplate reader. Laser radiation at λ=650nm-660nm with I =50 mW/cm2 at doses of 0, 3.0, 6.0, 9.0, and 12 J/cm2 was used for aPDT. A colony-counting method and confocal laser scanning microscopy (CLSM) were used to observe the neutralization of P. gingivalis. The fluorescent molecular probe 3'(p-hydroxyphenyl)-fluorescein and the reagent Singlet Oxygen Sensor Green were used to measure the quantities of •OH and 1O2 produced by 4i after irradiation with different light energies. RESULTS: The 4i conjugate was absorbed gradually by P. gingivalis, reaching a maximum at 30 min. A clear cytotoxic effect on P. gingivalis was observed with aPDT using 62.5 µM 4i, with colony counts dropping by a factor of 3.35 log10, indicating a sterilization rate of 99.95%. Light irradiation resulted principally in the production of • OHby 4i. A live/dead viability assay demonstrated substantial red fluorescence in P. gingivalis treated with aPDT. CONCLUSIONS: The results suggest that 4i-aPDT caused substantial cytotoxicity in P. gingivalis.

ACBD3 modulates KDEL receptor interaction with PKA for its trafficking via tubulovesicular carrier.

BACKGROUND: KDEL receptor helps establish cellular equilibrium in the early secretory pathway by recycling leaked ER-chaperones to the ER during secretion of newly synthesized proteins. Studies have also shown that KDEL receptor may function as a signaling protein that orchestrates membrane flux through the secretory pathway. We have recently shown that KDEL receptor is also a cell surface receptor, which undergoes highly complex itinerary between trans-Golgi network and the plasma membranes via clathrin-mediated transport carriers. Ironically, however, it is still largely unknown how KDEL receptor is distributed to the Golgi at steady state, since its initial discovery in late 1980s. RESULTS: We used a proximity-based in vivo tagging strategy to further dissect mechanisms of KDEL receptor trafficking. Our new results reveal that ACBD3 may be a key protein that regulates KDEL receptor trafficking via modulation of Arf1-dependent tubule formation. We demonstrate that ACBD3 directly interact with KDEL receptor and form a functionally distinct protein complex in ArfGAPs-independent manner. Depletion of ACBD3 results in re-localization of KDEL receptor to the ER by inducing accelerated retrograde trafficking of KDEL receptor. Importantly, this is caused by specifically altering KDEL receptor interaction with Protein Kinase A and Arf1/ArfGAP1, eventually leading to increased Arf1-GTP-dependent tubular carrier formation at the Golgi. CONCLUSIONS: These results suggest that ACBD3 may function as a negative regulator of PKA activity on KDEL receptor, thereby restricting its retrograde trafficking in the absence of KDEL ligand binding. Since ACBD3 was originally identified as PAP7, a PBR/PKA-interacting protein at the Golgi/mitochondria, we propose that Golgi-localization of KDEL receptor is likely to be controlled by its interaction with ACBD3/PKA complex at steady state, providing a novel insight for establishment of cellular homeostasis in the early secretory pathway.

Stem Cell-Based Therapy for Experimental Ischemic Stroke: A Preclinical Systematic Review.

Stem cell transplantation offers promise in the treatment of ischemic stroke. Here we utilized systematic review, meta-analysis, and meta-regression to study the biological effect of stem cell treatments in animal models of ischemic stroke. A total of 98 eligible publications were included by searching PubMed, EMBASE, and Web of Science from inception to August 1, 2020. There are about 141 comparisons, involving 5,200 animals, that examined the effect of stem cell transplantation on neurological function and infarct volume as primary outcome measures in animal models for stroke. Stem cell-based therapy can improve both neurological function (effect size, -3.37; 95% confidence interval, -3.83 to -2.90) and infarct volume (effect size, -11.37; 95% confidence interval, -12.89 to -9.85) compared with controls. These results suggest that stem cell therapy could improve neurological function deficits and infarct volume, exerting potential neuroprotective effect for experimental ischemic stroke, but further clinical studies are still needed.

Formation Mechanism of Cofactor Cys-Tyr in the Cysteine Dioxygenases (CDO and F2-CDO) and Its Influence on Catalysis: A QM/MM Study.

Cysteine dioxygenase (CDO) is a nonheme mononuclear iron enzyme, which catalyzes the oxidation of cysteine to cysteine sulfinic acid. Crystal structure studies of mammalian CDO showed that there is a cross-linked cysteine-tyrosine (Cys-Tyr) cofactor in its active site. Moreover, the formation of the Cys-Tyr cofactor requires the metal cofactor (Fe2+) and O2, and it was previously considered to substantially enhance the catalytic efficiency and half-life of CDO. Recently, a pure human CDO (F2-CDO) without including the Cys-Tyr cofactor was crystalized by the site-directed mutagenesis approach in the anaerobic condition. In this work, to gain insights into the formation mechanism of the Cys-Tyr cofactor and whether it can really promote the catalytic reactivity of CDO, a series of computational models have been constructed, and quantum mechanical/molecular mechanical (QM/MM) calculations have been performed. Our calculation results reveal that WT-CDO and F2-CDO follow different mechanisms for the formation of the Cys-Tyr cofactor. In F2-CDO, the cofactor formation contains the H-abstraction, C-S bond formation, intramolecular F migration, and aromatization of the residue F2Y157, in which the Fe-coordinate dioxygen can be recovered after the formation cofactor; however, in the WT-CDO, the cofactor formation shows some differences. During the reaction, hydrogen peroxide is generated, and the final aromatization requires the assistance of one water molecule. Furthermore, the overall barriers of cofactor formation are always higher than l-cysteine oxidation for both WT-CDO and F2-CDO irrespective of the absence or presence of the cofactor. Thus, we can theoretically confirm that the Cys-Tyr cofactor is not essential for the oxidation activity of CDO, and cofactor formation is just an accompanying reaction but not a prerequisite for the oxidation reaction. These results may provide useful information for understanding the catalysis of CDO.

Isoxanthanol alleviates Staphylococcus aureus induced chronic obstructive pulmonary disease in rat model through promotion of miR-145-5p expression.

The present study was aimed to evaluate the isoxanthanol against Staphylococcus aureus chronic obstructive pulmonary disease (COPD) in rat model. The isoxanthanol decreased the parasitic load by almost 99% in the Staphylococcus aureus infected rats. It significantly (P < 0.05) decreased mortality rate of the rats, prevented pulmonary tissue damage and aggregation of inflammatory cytokines. In Staphylococcus aureus infected rats, isoxanthanol treatment inhibited production of interleukin-18, interleukin-1ß and TNF-α significantly (P < 0.05) in the BALF and pulmonary tissues. Treatment of the Staphylococcus aureus-infected rats with isoxanthanol inhibited up-regulation of NLRP3, ASC and caspase-1 expression. In Staphylococcus aureus-infected rats the expression of miR-145-5p was remarkably increased on treatment with isoxanthanol. In summary, isoxanthanol prevents Staphylococcus aureus-induced COPD in rats through up-regulation of miR-145-5p and suppression of inflammatory cytokines. Therefore, isoxanthanol can be of therapeutic importance for the treatment of Staphylococcus aureus induced COPD.

PTP-MEG2 regulates quantal size and fusion pore opening through two distinct structural bases and substrates.

Tyrosine phosphorylation of secretion machinery proteins is a crucial regulatory mechanism for exocytosis. However, the participation of protein tyrosine phosphatases (PTPs) in different exocytosis stages has not been defined. Here we demonstrate that PTP-MEG2 controls multiple steps of catecholamine secretion. Biochemical and crystallographic analyses reveal key residues that govern the interaction between PTP-MEG2 and its substrate, a peptide containing the phosphorylated NSF-pY83 site, specify PTP-MEG2 substrate selectivity, and modulate the fusion of catecholamine-containing vesicles. Unexpectedly, delineation of PTP-MEG2 mutants along with the NSF binding interface reveals that PTP-MEG2 controls the fusion pore opening through NSF independent mechanisms. Utilizing bioinformatics search and biochemical and electrochemical screening approaches, we uncover that PTP-MEG2 regulates the opening and extension of the fusion pore by dephosphorylating the DYNAMIN2-pY125 and MUNC18-1-pY145 sites. Further structural and biochemical analyses confirmed the interaction of PTP-MEG2 with MUNC18-1-pY145 or DYNAMIN2-pY125 through a distinct structural basis compared with that of the NSF-pY83 site. Our studies thus provide mechanistic insights in complex exocytosis processes.