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1.
Curr Biol ; 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-35016009

RESUMO

Coordination of bilateral movements is essential for a large variety of animal behaviors. The olivocerebellar system is critical for the control of movement, but its role in bilateral coordination has yet to be elucidated. Here, we examined whether Purkinje cells encode and influence synchronicity of left-right whisker movements. We found that complex spike activity is correlated with a prominent left-right symmetry of spontaneous whisker movements within parts, but not all, of Crus1 and Crus2. Optogenetic stimulation of climbing fibers in the areas with high and low correlations resulted in symmetric and asymmetric whisker movements, respectively. Moreover, when simple spike frequency prior to the complex spike was higher, the complex spike-related symmetric whisker protractions were larger. This finding alludes to a role for rebound activity in the cerebellar nuclei, which indeed turned out to be enhanced during symmetric protractions. Tracer injections suggest that regions associated with symmetric whisker movements are anatomically connected to the contralateral cerebellar hemisphere. Together, these data point toward the existence of modules on both sides of the cerebellar cortex that can differentially promote or reduce the symmetry of left and right movements in a context-dependent fashion.

2.
J Ethnopharmacol ; : 114938, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34999144

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Silybum marianum is a traditional Chinese medicine that has been used for treating liver disease. Silybin consisting of silybin A and silybin B, is a member of Silybum marianum, and exerts a therapeutic effect on many diseases. However, the protective effect of silybin on cisplatin-induced neurotoxicity and the stereoisomer contributing to the effect remain unknown. AIM OF THE STUDY: The present study aimed to study the effect of silybin on cisplatin-induced neuronal injury, compare the difference of protective effect between silybin A and silybin B, and the potential mechanism. MATERIALS AND METHODS: High performance liquid chromatography (HPLC) was used to separate silybin A and silybin B. X-ray crystallographic analysis in combination with experimental and calculated ECD were performed to identify the structure of silybin A and silybin B. The toxicity of the silybin or cisplatin against murine hippocampal neuronal HT22 cells was determined through MTT assay. The cell cycle and cell apoptosis were measured by PI staining and Annexin V-FITC/PI staining, respectively, and then subjected to flow cytometry. Western blot analysis was conducted to quantify the expression of proteins related to apoptosis and DNA damage. Immunofluorescence was used to evaluate the expression of DNA damage marker. In vivo experiment, the behavioral analysis was determined through pole test and swimming test. The index of superoxide dismutase (SOD), reduced glutathione (GSH), total antioxidant capacity (T-AOC) and lipid peroxidation (LPO) were examined to evaluate the antioxidant capacity in mice brain. Nissl staining was used to detect the neuronal viability in hippocampus. RESULTS: We successfully separate and identify silybin A and silybin B. We found both silybin A and silybin B alleviated cisplatin-induced apoptosis and cell cycle arrest in HT22 cells, and silybin B was more effective. We chose silybin B for further mechanism investigation, and found silybin B alleviated DNA damage by enhancing phosphorylation of ATR and decreasing expression of γ-H2AX. In the in vivo experiment, we observed that silybin B markedly improved the behavioral abnormalities in cisplatin-treated mice, reduced LPO level while increased SOD, GSH and T-AOC in mice brain tissue. Nissl staining showed that silybin B increased the cell viability of neurons in the hippocampal DG, CA1 and CA3 regions. CONCLUSIONS: These results suggest that silybin B might serve as a promising drug candidate in mitigating cisplatin-induced neural injury in the brain and thereby improving the chemotherapeutic outcomes.

3.
J Neurosci Res ; 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34850425

RESUMO

Most studies investigating the impact of the cerebral cortex (CC) onto the cerebellum highlight the role of the pons, which provides the mossy fibers to the cerebellum. However, cerebro-cerebellar communication may also be mediated by the nuclei of the mesodiencephalic junction (MDJ) that project to the inferior olive (IO), which in turn provides the climbing fibers to the molecular layer. Here, we uncover the precise topographic relations of the inputs and outputs of the MDJ using multiple, classical, and transneuronal tracing methods as well as analyses of mesoscale cortical injections from Allen Mouse Brain. We show that the caudal parts of the CC predominantly project to the principal olive via the rostral MDJ and that the rostral parts of the CC predominantly project to the rostral medial accessory olive via the caudal MDJ. Moreover, using triple viral tracing technology, we show that the cerebellar nuclei directly innervate the neurons in the MDJ that receive input from CC and project to the IO. By unraveling these topographic and prominent, mono- and disynaptic projections through the MDJ, this work establishes that cerebro-cerebellar communication is not only mediated by the pontine mossy fiber system, but also by the climbing fiber system.

5.
Artigo em Inglês | MEDLINE | ID: mdl-34913180

RESUMO

BACKGROUND AND OBJECTIVE: Hypoglycemia induced by direct-acting antiviral agents (DAAs) for chronic hepatitis C virus (HCV) infection is a rare but potentially life-threatening adverse reaction, which led to warnings by competent authorities. We therefore aimed to examine the hypoglycemic safety signal for DAAs. METHODS: Reports to the US Food and Drug Administration Adverse Event Reporting System (FAERS) from 1 October 2012 to 31 March 2020 were analyzed. The Medical Dictionary for Regulatory Activities was used to identify hypoglycemia cases. A case by non-case disproportionality approach was used whereby reporting odds ratio (ROR) with 95% confidence intervals (CI) were calculated. RESULTS: In HCV infection with diabetes patients, the cumulative frequency of hypoglycemic ADRs was 21.85/1000 for reports involving DAAs versus 13.50/1000 for reports involving other medications; For DAAs as a class drug, a nearly double increased reporting odds for hypoglycemia was observed (ROR: 1.63, 95% CI: 1.11-2.41). However, in DAAs subgroup analysis, only telaprevir (ROR: 1.66, 95% CI: 1.01-2.74) and elbasvir/grazoprevir (ROR: 2.25, 95% CI: 1.05-4.83) were associated with increased reporting risk of hypoglycemia during corresponding marketing period; when combined with insulins and sulfonylureas, DAAs were associated with increased reporting risk for hypoglycemia (ROR: 1.98, 95% CI: 1.36-2.88; ROR: 1.62, 95% CI: 1.06-2.48), but concomitant biguanides, dipeptidyl peptidase IV (DPP-4) inhibitors or glucagon-like peptide-1 receptor agonists (GLP-1RAs) were not significant. CONCLUSIONS: This study supports the current recommendation for cautious about hypoglycemic risk relating to the use of DAAs. Treatment with DAAs and antidabetic agents (especially insulins and sulfonylureas) will increase hypoglycemia reporting risk. Physicians and pharmacists should be aware of this risk when prescribing DAAs for patients suffering from diabetes, advanced age or liver decompensation.

6.
PeerJ ; 9: e12513, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34900430

RESUMO

Oplopanax elatus (Nakai) Nakai, in the Araliaceae family, has been used in traditional Chinese medicine (TCM) to treat diseases as an adaptogen for thousands of years. This study established an ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF/MS) method to identify chemical components and biotransformation metabolites of root bark extract from O. elatus. A total of 18 compounds were characterized in O. elatus extract, and 62 metabolites by human intestinal microbiota were detected. Two polyynes, falcarindiol and oplopandiol were recognized as the main components of O. elatus, whose metabolites are further illustrated. Several metabolic pathways were proposed to generate the detected metabolites, including methylation, hydrogenation, demethylation, dehydroxylation, and hydroxylation. These findings indicated that intestinal microbiota might play an essential role in mediating the bioactivity of O. elatus.

7.
Artigo em Inglês | MEDLINE | ID: mdl-34790247

RESUMO

Objective: This study is aimed to observe the clinical effects of integrated traditional Chinese and Western medicine in treating severe preeclampsia (SPE) and its effects on maternal and infant outcomes after cesarean section under combined lumbar and epidural anesthesia. Method: One hundred and sixty-six pregnant women with SPE were randomly divided into an experimental group and control group, with 83 cases in each group. The control group was given conventional treatments such as magnesium sulfate, and the experimental group received self-made traditional Chinese medicine decoction for oral administration. Results: The total clinical effective rate of treatment in the experimental group was significantly higher than that in the control group. After treatment, the systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and 24 h proteinuria (24 h PRO) levels of the experimental group were significantly lower than those of the control group. After cesarean section (c-section) under combined lumbar and epidural anesthesia, there were statistically significant differences in placental abruption, uterine weakness, fetal intrauterine distress, and neonatal asphyxia in the experimental group, while there were no significant differences in oligohydramnios. After treatment, the contents of inflammatory factors in both groups decreased, and the decrease was more prominent in the experimental group. After treatment, the levels of blood urea nitrogen (BUN), serum creatinine (Scr), and albumin (Alb) and ß2 microglobulin (ß2-MG) of the two groups of patients decreased, and the levels of them in the experimental group decreased. After treatment, the levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the two groups increased. However, the levels of malondialdehyde (MDA), lipid peroxide (LPO), and advanced oxidation protein products (AOPP) all reduced, and the increase or decrease in the experimental group was more prominent. Conclusion: The combination of traditional Chinese and Western medicine can reduce the blood pressure of a patient with SPE. After the combined spinal-epidural anesthesia and cesarean section, it can significantly improve the maternal and infant outcomes and renal function, reduce inflammatory factors levels and body oxidative stress, and increase the activities of antioxidant enzymes.

8.
Toxins (Basel) ; 13(11)2021 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-34822538

RESUMO

Multicopper oxidases (MCOs) are a diverse group of enzymes that could catalyze the oxidation of different xenobiotic compounds, with simultaneous reduction in oxygen to water. Aside from laccase, one member of the MCO superfamily has shown great potential in the biodegradation of mycotoxins; however, the mycotoxin degradation ability of other MCOs is uncertain. In this study, a novel MCO-encoding gene, StMCO, from Streptomyces thermocarboxydus, was identified, cloned, and heterologously expressed in Escherichia coli. The purified recombinant StMCO exhibited the characteristic blue color and bivalent copper ion-dependent enzyme activity. It was capable of oxidizing the model substrate ABTS, phenolic compound DMP, and azo dye RB5. Notably, StMCO could directly degrade aflatoxin B1 (AFB1) and zearalenone (ZEN) in the absence of mediators. Meanwhile, the presence of various lignin unit-derived natural mediators or ABTS could significantly accelerate the degradation of AFB1 and ZEN by StMCO. Furthermore, the biological toxicities of their corresponding degradation products, AFQ1 and 13-OH-ZEN-quinone, were remarkably decreased. Our findings suggested that efficient degradation of mycotoxins with mediators might be a common feature of the MCOs superfamily. In summary, the unique properties of MCOs make them good candidates for degrading multiple major mycotoxins in contaminated feed and food.

9.
FEBS J ; 2021 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-34741776

RESUMO

Retinal pigment epithelium (RPE) cell damage is implicated in the pathogenesis of age-related macular degeneration (AMD). An increase of interferon-γ (IFN-γ) levels was observed in patients with AMD, but whether inflammatory factors are causally related to AMD progression is unclear. Here, we demonstrate a direct causal relationship between IFN-γ and RPE cell death. IFN-γ induced human retinal pigment epithelial cell (ARPE-19) death accompanied by increases in Fe2+ , reactive oxygen species, lipid peroxidation, and glutathione (GSH) depletion, which are main characteristics of ferroptosis. Mechanistically, IFN-γ upregulates the level of intracellular Fe2+ through inhibiting Fe2+ efflux protein SLC40A1 and induces GSH depletion by blocking cystine/glutamate antiporter, System xc-. At the same time, treatment with IFN-γ decreases the level of glutathione peroxidase 4 (GPx4), rendering the cells more sensitive to ferroptosis. JAK1/2 and STAT1 inhibitors could reverse the reduction of SLC7A11, GPx4 and GSH expression induced by IFN-γ, indicating IFN-γ induces ARPE-19 cell ferroptosis via activation of the JAK1-2/STAT1/SLC7A11 signaling pathway. The above results were largely confirmed in IFN-γ-treated mice in vivo. Finally, we used sodium iodate (NaIO3 )-induced retinal degeneration to further explore the role of ferroptosis in AMD in vivo. Consistent with the role of IFN-γ, treatment with NaIO3 decreased SLC7A11, GPx4 and SLC40A1 expressions. NaIO3 -induced RPE damage was accompanied by increased iron, lipid peroxidation products (4-hydroxynonenal, malondialdehyde), and GSH depletion, and ferroptosis inhibitors could reverse the above phenomenon. Taken together, our findings suggest that inhibiting ferroptosis or reducing IFN-γ may serve as a promising target for AMD.

10.
Am J Dermatopathol ; 43(12): e273-e276, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34797808

RESUMO

ABSTRACT: A 9-year-old girl presented with a slow-growing and painless mass for 7 months in the soft tissue of the sacrococcygeal region. Magnetic resonance imaging revealed a well-circumscribed solid mass located in the subcutaneous soft tissue of the sacrococcygeal area, but not affecting bone structures. The mass was completely removed, and the disorder was diagnosed as myxopapillary ependymoma. In addition, the MYCN gene amplification status of the tumor was evaluated. Extra-axial ependymomas are very rare tumors with a tendency to metastasis, but they are usually regarded as low-grade ependymomas. Long-time surveillance and follow-up are necessary even after complete excision. Besides, we also discuss the diagnosis of primary soft tissue myxopapillary ependymoma.

11.
Plant Physiol Biochem ; 169: 70-80, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34773804

RESUMO

In the past, the PHB gene function was mainly focused on anti-cell proliferation and antitumor effects. But the molecular mechanism of the PHB gene regarding saline and oxidative stresses is unclear. To study the role of AtPHB6 in salt and oxidative stress, AtPHB6 was cloned from A. thaliana. Bioinformatics analysis showed that AtPHB6 was closely related to AtPHB1 and AtPHB2, which are both type II PHB. RT-qPCR results indicated that the AtPHB6 in the leaves and roots of A. thaliana was obviously induced under different stress treatments. AtPHB6-overexpressing plants were larger and more lush than wild-type and mutant plants when placed under stress treatments during seed germination. The root length and fresh weight of AtPHB6 transgenic plants showed the best resistance compared to wild-type plants under different treatments, in contrast, the AtPHB6 mutants had the worst resistance during the seedling stage. AtSOT12 was an interacting protein of AtPHB6, which screened by yeast two-hybrid system. The interaction between the two proteins were further confirmed using in vitro pull-down experiments and in vivo BiFC experiments. Subcellular localization showed both AtPHB6 and AtSOT12 protein expressed in the nucleus and cytoplasm. The H2O2 content in both the transgenic AtPHB6 and AtSOT12 plants were lower than that in the wild type under stresses. Thus, AtPHB6 increased plant resistance to salt stress and interacted with the AtSOT12 protein.

12.
BMC Gastroenterol ; 21(1): 437, 2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34809574

RESUMO

BACKGROUND: Heat shock protein 70 (HSP70) has been associated with the clinicopathological characteristics and prognosis of many cancers types, implying that it is a potential cancer biomarker. However, no consensus has been reached regarding its clinicopathological and prognostic significance in patients with gastric cancer. To address this gap, we performed a systematic review and meta-analysis. METHODS: We searched PubMed, Embase, and the Cochrane Library for full-text literature according to the eligibility criteria. We used the odds ratio and hazard ratio as the suitable parameters to evaluate the clinicopathological and prognostic significance of HSP70. The statistical analysis was performed using STATA 15.0. RESULTS: After inclusion and exclusion of studies based on the eligibility criteria, data of 1,307 patients with gastric cancer from 9 studies were finally included. The pooled outcomes implied that HSP70 expression was significantly correlated with higher differentiation degrees, intestinal gastric cancer, and lymphovascular invasion but not with age, gender, depth of invasion, Helicobacter pylori infection, lymph node invasion, TNM stages, and metastasis. The pooled HR showed no significant correlation between HSP70 expression and overall survival of gastric cancer patients. CONCLUSIONS: Our meta-analysis showed that HSP70 plays a complicated role in the development of gastric cancer. It may be directly engaged in tumour differentiation and distant invasion but cannot be considered a biomarker for predicting the prognosis of gastric cancer.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Biomarcadores Tumorais , Proteínas de Choque Térmico HSP70 , Humanos , Prognóstico
13.
ACS Omega ; 6(40): 26613-26622, 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34661015

RESUMO

A clean and efficient conversion process is essential for the utilization of low-rank coals. Lignite, a typical representative of the low-rank coal family, has huge potential for the production of valuable chemicals via the oxidative depolymerization reaction. Ruthenium ion-catalyzed oxidation (RICO) is an effective route for lignite depolymerization under mild conditions, but the high cost of precious Ru limits the potential large-scale application of RICO. How to recycle and reuse Ru is critical to promote the application of RICO. In this work, a novel and efficient approach for reusing Ru through recycling the solvent mixture containing Ru was established for RICO. First, the influence of different reaction parameters on the depolymerization degree of lignite and benzene polycarboxylic acid (BPCA) yields was investigated. Second, the distribution of Ru in the organic phase (OP), aqueous phase (AP), and residual solid phase (RSP) was analyzed after the RICO reaction. Finally, based on the distribution of Ru in different phases, a novel route of recycling Ru by reusing the Ru-containing solvents was proposed. The results showed that the dosage of RuCl3 and NaIO4 had a significant influence on both the depolymerization degree of lignite and BPCA yields. The distribution of Ru had a close relationship with the depolymerization degree of lignite and the dosage of NaIO4. After the depolymerization reaction, the CCl4 phase containing Ru was reused directly as the solvent for the next run, which could fulfill the reuse of both CCl4 and Ru. The results proved that the Ru-containing CCl4 phase could maintain catalytic performance for 5 runs. This work provides an efficient route to reuse Ru for the RICO depolymerization of lignite into valuable organic acids. As far as we know, this is the first report concerning the recycling and reuse of Ru during the RICO of lignite. This work is important for the application of RICO in lignite depolymerization.

14.
Plant Dis ; 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34645309

RESUMO

Wheat pathogens, especially those causing powdery mildew and stripe rust, seriously threaten yield worldwide. Utilizing newly identified disease resistance genes from wheat relatives is an effective strategy to minimize disease damage. In this study, chromosome-specific molecular markers for the 3Sb and 7Sb chromosomes of Aegilops bicornis were developed using PCR-based landmark unique gene (PLUG) primers for screening wheat-Ae. bicornis progenies. Fluorescence in situ hybridization (FISH) was performed to further identify wheat-Ae. bicornis progenies using oligonucleotides probes Oligo-pSc119.2-1, Oligo-pTa535-1, and Oligo-(GAA)8. After establishing Ae. bicornis 3Sb and 7Sb chromosome-specific FISH markers, Holdfast (common wheat)-Ae. bicornis 3Sb addition, 7Sb addition, 3Sb(3A) substitution, 3Sb(3B) substitution, 3Sb(3D) substitution, 7Sb(7A) substitution, and 7Sb(7B) substitution lines were identified by the molecular and cytological markers. Stripe rust and powdery mildew resistance, along with agronomic traits were investigated to evaluate the breeding potential of these lines. Holdfast and Holdfast-Ae. bicornis progenies were all highly resistant to stripe rust, indicating that the stripe rust resistance might derive from Holdfast. However, Holdfast-Ae. bicornis 3Sb addition, 3Sb(3A) substitution, 3Sb(3B) substitution, and 3Sb(3D) substitution lines showed high resistance to powdery mildew while Holdfast was highly susceptible, indicating that chromosome 3Sb of Ae. bicornis carries previously unknown powdery mildew resistance gene(s). Additionally, the transfer of the 3Sb chromosome from Ae. bicornis to wheat significantly increased tiller number, but chromosome 7Sb has a negative effect on agronomic traits. Therefore, wheat germplasm containing Ae. bicornis chromosome 3Sb has potential to contribute to improving powdery mildew resistance and tiller number during wheat breeding.

15.
Int J Biol Macromol ; 192: 250-257, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34627844

RESUMO

The bioconversion of chitin into N-acetyl-d-glucosamine (GlcNAc) using chitinolytic enzymes is one of the important avenues for chitin valorization. However, industrial applications of chitinolytic enzymes have been limited by their poor thermostability. Therefore, it is necessary to discover thermostable chitinolytic enzymes for GlcNAc production from chitin. In this study, two chitinolytic enzyme-encoding genes CaChiT and CaHex from Caldicellulosiruptor acetigenus were identified and heterologously expressed in Escherichia coli. The purified recombinant CaChiT and CaHex showed optimal activities at 70 °C and 90 °C respectively, and exhibited good thermostability over a range of temperature below 70 °C and broad pH stability at pH range of 3.0-8.0. CaChiT and CaHex were active on colloidal chitin, pNP-(GlcNAc)2, pNP-(GlcNAc)3, and pNP-GlcNAc, pNP-(GlcNAc)2, pNP-(GlcNAc)3, pNP-Glc respectively. Besides, the chitin oligosaccharides and colloidal chitin hydrolysis profiles revealed that CaChiT degraded chitin chains through exo-mode of action. Furthermore, CaChiT and CaHex exhibited a synergistic effect in the degradation of colloidal chitin, reaching 0.60 mg/mL of GlcNAc production after 1 h incubation. These results suggested that a combination of CaChiT and CaHex have great potential for industrial applications in the enzymatic production of GlcNAc from chitin-containing biowastes.

16.
Artigo em Chinês | MEDLINE | ID: mdl-34628826

RESUMO

Objective:To investigate the morphology of bone markers around the parapharyngeal internal carotid artery and its adjacent relationship. Methods:The imaging date of 30 cases which had normal structure of the skull by CTA were randomly selected. Through maxillary sinus approach, the morphology of peripheral bony landmarks (sphenoid spine, vaginal process of the tympanic bone, tympanic crest) from the parapharyngeal internal carotid artery to the entrance of the internal carotid artery and the adjacent relationship with the parapharyngeal internal carotid artery were observed for imaging anatomy. Results:With the external opening of the internal carotid artery as the reference point, the parapharyngeal internal carotid artery was divided into 10 sides (16.7%) in the direction of atlas and 6 sides(10%) in the direction of temporomandibular joint, 44 sides (73.3%) were close to midline. On 53 sides (88.3%), the morphology of sphenoid spine became triangular shape with upper width and lower width, 6 sides (10%) became irregular type with terminal bifurcation, and 1 side (1.7%) had sphenoid spine missing. The shape of the vaginal process of the tympanic bone (VPTB) was a flat, irregular polygon with a smooth surface and no loss on 60 sides (100%). The tympanic crest (TC) was a continuation of the VPTB to the sphenoid spine. It was located between the sphenoid spine and the VPTB. 51 sides (85%) of the TC and 9 sides (15%) of the TC were missing. The three constituted a special anatomical structure located in front of the internal carotid artery of the parapharyngeal segment, which can be divided into 43 inverted J-types (71.7%) and 17 irregular types (28.3%). Conclusion:The special anatomical area composed of sphenoid spine, vaginal process of the tympanic bone, tympanic crest is closely related to the parapharyngeal internal carotid artery observed by maxillary sinus approach, which is the anatomical basis for endoscopic surgery to find the parapharyngeal internal carotid artery. CTA can provide individualized surgical basis.


Assuntos
Pontos de Referência Anatômicos , Artéria Carótida Interna , Artéria Carótida Interna/diagnóstico por imagem , Endoscopia , Feminino , Humanos , Seio Maxilar , Crânio
17.
Biotechnol Biofuels ; 14(1): 202, 2021 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-34656167

RESUMO

BACKGROUND: Glucoamylase is an important industrial enzyme in the saccharification of starch into glucose. However, its poor thermostability and low catalytic efficiency limit its industrial saccharification applications. Therefore, improving these properties of glucoamylase is of great significance for saccharification in the starch industry. RESULTS: In this study, a novel glucoamylase-encoding gene TlGa15B from the thermophilic fungus Talaromyces leycettanus JCM12802 was cloned and expressed in Pichia pastoris. The optimal temperature and pH of recombinant TlGa15B were 65 â„ƒ and 4.5, respectively. TlGa15B exhibited excellent thermostability at 60 â„ƒ. To further improve thermostability without losing catalytic efficiency, TlGa15B-GA1 and TlGa15B-GA2 were designed by introducing disulfide bonds and optimizing residual charge-charge interactions in a region distant from the catalytic center. Compared with TlGa15B, mutants showed improved optimal temperature, melting temperature, specific activity, and catalytic efficiency. The mechanism underlying these improvements was elucidated through molecular dynamics simulation and dynamics cross-correlation matrices analysis. Besides, the performance of TlGa15B-GA2 was the same as that of the commercial glucoamylase during saccharification. CONCLUSIONS: We provide an effective strategy to simultaneously improve both thermostability and catalytic efficiency of glucoamylase. The excellent thermostability and high catalytic efficiency of TlGa15B-GA2 make it a good candidate for industrial saccharification applications.

18.
Cancer Cell Int ; 21(1): 577, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34717617

RESUMO

BACKGROUND: The cancer caused by Kaposi's sarcoma-associated herpesvirus (KSHV) infection is one of the major causes of death in AIDS patients. Some patients have neurological symptoms, which appear to be associated with KSHV infection, based on the neurotropic tendency of this virus in recent years. The objectives of this study were to investigate the effects of KSHV infection on neuronal SH-SY5Y cells and to identify differentially expressed genes. METHODS: KSHV was collected from islk.219 cells. Real-time PCR was used to quantify KSHV copy numbers. KSHV was used to infect SH-SY5Y cells. The KSHV copy number in the supernatants and mRNA levels of latency-associated nuclear antigen (LANA), ORF26, K8.1 A, and replication and transcriptional activator (RTA) were detected by real-time PCR. Proteins were detected by immunohistochemistry. The effect of KSHV infection on cell proliferation was detected by MTT and Ki-67 staining. Cell migration was evaluated by Transwell and wound healing assays. The cell cycle was analyzed by flow cytometry. The expression of CDK4, CDK5, CDK6, cyclin D1, and p27 were measured by western blotting. The levels of cell cycle proteins were re-examined in LANA-overexpressing SH-SY5Y cells. Transcriptome sequencing was used to identify differentially expressed genes in KSHV-infected cells. The levels of Notch signaling pathway proteins were measured by western blotting. RNA interference was used to silence Notch1 and proliferation were analyzed again. RESULTS: SH-SY5Y cells were successfully infected with KSHV, and they maintained the ability to produce virions. KSHV-infected SH-SY5Y expressed LANA, ORF26, K8.1 A, and RTA. After KSHV infection, cell proliferation was enhanced, but cell migration was suppressed. KSHV infection accelerated the G0/G1 phase. CDK4, CDK5, CDK6, and cyclin D1 expression was increased, whereas p27 expression was decreased. After LANA overexpression, CDK4, CDK6 and cyclin D1 expression was increased. Transcriptome sequencing showed that 11,258 genes were upregulated and 1,967 genes were downregulated in KSHV-infected SH-SY5Y. The Notch signaling pathway played a role in KSHV infection in SH-SY5Y, and western blots confirmed that Notch1, NICD, RBP-Jĸ and Hes1 expression was increased. After silencing of Notch1, the related proteins and cell proliferation ability were decreased. CONCLUSIONS: KSHV infected SH-SY5Y cells and promoted the cell proliferation. KSHV infection increased the expression of Notch signaling pathway proteins, which may have been associated with the enhanced cell proliferation.

19.
Toxins (Basel) ; 13(9)2021 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-34564606

RESUMO

Ligninolytic enzymes, including laccase, manganese peroxidase, and dye-decolorizing peroxidase (DyP), have attracted much attention in the degradation of mycotoxins. Among these enzymes, the possible degradation pathway of mycotoxins catalyzed by DyP is not yet clear. Herein, a DyP-encoding gene, StDyP, from Streptomyces thermocarboxydus 41291 was identified, cloned, and expressed in Escherichia coli BL21/pG-Tf2. The recombinant StDyP was capable of catalyzing the oxidation of the peroxidase substrate 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), phenolic lignin compounds 2,6-dimethylphenol, and guaiacol, non-phenolic lignin compound veratryl alcohol, Mn2+, as well as anthraquinone dye reactive blue 19. Moreover, StDyP was able to slightly degrade zearalenone (ZEN). Most importantly, we found that StDyP combined the catalytic properties of manganese peroxidase and laccase, and could significantly accelerate the enzymatic degradation of ZEN in the presence of their corresponding substrates Mn2+ and 1-hydroxybenzotriazole. Furthermore, the biological toxicities of the main degradation products 15-OH-ZEN and 13-OH-ZEN-quinone might be remarkably removed. These findings suggested that DyP might be a promising candidate for the efficient degradation of mycotoxins in food and feed.

20.
Ann Transl Med ; 9(15): 1249, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34532386

RESUMO

Background: Age-related macular degeneration (AMD) is one of the leading causes of permanent visual impairment in the elderly. Blue light (BL) has been reported to cause retinal damage and contribute to the onset and development of severe AMD. N-retinylidene-N-retinylethanolamine (A2E), a lipofuscin fluorophore, accumulates with ageing in the retinal pigment epithelium (RPE) cells. Once exposed to BL, A2E easily oxidizes to A2E-epoxides, causing oxidative-stress injury to the retina. Lipoxin A4 (LXA4), an endogenous anti-antioxidant lipid, plays a key role in multiple organs by binding to the formyl-peptide receptor-like 1 (FPRL1). This study examined the protective effects of LXA4 on oxidative-stress injury induced by BL exposure, and clarified the underlying mechanisms in cultured RPE cells and Balb-c mice. Methods: LXA4 diluent was orally administered to mice before retinal degeneration was established. Optical coherence tomography, retinal histology, and RPE cell injury were assessed. Results: LXA4 administration significantly ameliorated retinal damage as evidenced by the thicknesses of the retinal layers and the tight junctions of RPE cells in vivo. LXA4 inhibited BL-induced reactive oxygen species (ROS) production, reduced tight junctions, and the death of A2E-laden RPE cells. LXA4 also potently increased the expression of haem oxygenase-1 (HO1) and NAD(P)H quinone oxidoreductase 1 (NQO1), probably by decreasing the association between nuclear factor erythroid 2-related factor 2 (NRF2) and Kelch-like ECH (Epichlorohydrin) -associated protein 1 (Keap1), and ameliorating NRF2 nuclear translocation and the antioxidant response element (ARE) deoxyribonucleic acid (DNA) binding activity. Conclusions: Our results showed that LXA4 ameliorated retinal degeneration, and should be considered in the prevention and treatment of AMD.

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