ABSTRACT
In this study, the plasma graft polymerization technique was used to graft glycidyl methacrylate (GMA) onto polypropylene (PP) melt-blown fibers, which were subsequently aminated with N-methyl-D-glucamine (NMDG) by a ring-opening reaction, resulting in the formation of a boron adsorbent denoted as PP-g-GMA-NMDG. The optimal conditions for GMA concentration, grafting time, grafting temperature, and the quantity of NMDG were determined using both single factor testing and orthogonal testing. These experiments determined the optimal process conditions to achieve a high boron adsorption capacity of PP-g-GMA-NMDG. Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersion spectrum analysis (EDS), and water contact angle measurements were performed to characterize the prepared adsorbent. Boron adsorption experiments were carried out to investigate the effects of pH, time, temperature, and boron concentration on the boron adsorption capacity of PP-g-GMA-NMDG. The adsorption isotherms and kinetics of PP-g-GMA-NMDG for boron were also studied. The results demonstrated that the adsorption process followed a pseudo-second-order kinetic model and a Langmuir isothermal model. At a pH of 6, the maximum saturation adsorption capacity of PP-g-GMA-NMDG for boron was 18.03 ± 1 mg/g. In addition, PP-g-GMA-NMDG also showed excellent selectivity for the adsorption of boron in the presence of other cations, such as Na+, Mg2+, and Ca2+, PP-g-GMA-NMDG, and exhibited excellent selectivity towards boron adsorption. These results indicated that the technique of preparing PP-g-GMA-NMDG is both viable and environmentally benign. The PP-g-GMA-NMDG that was made has better qualities than other similar adsorbents. It has a high adsorption capacity, great selectivity, reliable repeatability, and easy recovery. These advantages indicated that the adsorbents have significant potential for widespread application in the separation of boron in water.
ABSTRACT
This research focuses on modifying discarded feathers by grafting glycidyl methacrylate (GMA) onto their surface through thiolation, followed by an epoxy ring-opening reaction with N-methyl-D-glucamine (NMDG) to synthesize feather-based boron adsorbents. Optimization of the adsorbent preparation conditions was achieved through single-factor experiments, varying temperature, time, GMA concentration, and initiator dosage. The synthesized adsorbent (F-g-GMA-NMDG) underwent characterization using Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The adsorption behavior of the adsorbent was studied, and its boron adsorption capacity at different temperatures was determined through static adsorption kinetic curves. Analysis of adsorption isotherms, kinetics, and thermodynamics was conducted. Results indicate that the boron adsorption process by F-g-GMA-NMDG follows a pseudo-second-order model. The adsorption process is endothermic, with higher temperatures promoting adsorption efficiency. Gibbs free energy (ΔG) confirms the spontaneity of the adsorption process. Enhanced adsorption efficacy was observed under neutral and acidic pH conditions. After four cycles, the adsorbent maintained its adsorption efficiency, demonstrating its stability and potential for reuse. This study provides novel insights into both the treatment of discarded feathers and the development of boron adsorbents.
ABSTRACT
An electrosynthesis of spiro-indolenines in batch and continuous flow was achieved through dearomative arylation of indoles with good functional group compatibility. User-friendly undivided cells were used under catalyst- and oxidant-free conditions. Moreover, the use of a flow electrolysis cell gave high daily productivity and excellent scale-up potential under less supporting electrolyte and higher substrate concentration conditions.
ABSTRACT
Usher syndrome is the most common cause of deafness-blindness in the world. Usher syndrome type 1B (USH1B) is associated with mutations in MYO7A. Patients with USH1B experience deafness, blindness, and vestibular dysfunction. In this study, we applied adeno-associated virus (AAV)-mediated gene therapy to the shaker-1 (Myo7a4626SB/4626SB) mouse, a model of USH1B. The shaker-1 mouse has a nonsense mutation in Myo7a, is profoundly deaf throughout life, and has significant vestibular dysfunction. Because of the â¼6.7-kb size of the MYO7A cDNA, a dual-AAV approach was used for gene delivery, which involves splitting human MYO7A cDNA into 5' and 3' halves and cloning them into two separate AAV8(Y733F) vectors. When MYO7A cDNA was delivered to shaker-1 inner ears using the dual-AAV approach, cochlear hair cell survival was improved. However, stereocilium organization and auditory function were not improved. In contrast, in the vestibular system, dual-AAV-mediated MYO7A delivery significantly rescued hair cell stereocilium morphology and improved vestibular function, as reflected in a reduction of circling behavior and improved vestibular sensory-evoked potential (VsEP) thresholds. Our data indicate that dual-AAV-mediated MYO7A expression improves vestibular function in shaker-1 mice and supports further development of this approach for the treatment of disabling dizziness from vestibular dysfunction in USH1B patients.
ABSTRACT
Sorbitol, a product primarily derived from glucose hydrogenation, has extensive applications in the pharmaceutical, chemical and other industries. Amino styrene-co-maleic anhydride polymer encapsulated on activated carbon (Ru/ASMA@AC) catalysts were developed for efficient glucose hydrogenation and were prepared and confined Ru by coordination with styrene-co-maleic anhydride polymer (ASMA). Through single-factor experiments, optimal conditions were determined to be 2.5 wt.% ruthenium loading and a catalyst usage of 1.5 g, 20% glucose solution at 130 °C, reaction pressure of 4.0 MPa, and a stirring speed of 600 rpm for 3 h. These conditions achieved a high glucose conversion rate of 99.68% and a sorbitol selectivity of 93.04%. Reaction kinetics testing proved that the hydrogenation of glucose catalyzed by Ru/ASMA@AC was a first-order reaction, with a reaction activation energy of 73.04 kJ/mol. Furthermore, the catalytic performance of the Ru/ASMA@AC and Ru/AC catalysts for glucose hydrogenation were compared and characterized by various detection methods. The Ru/ASMA@AC catalyst exhibited excellent stability after five cycles, whereas the traditional Ru/AC catalyst suffered from a 10% decrease in sorbitol yield after three cycles. These results suggest that the Ru/ASMA@AC catalyst is a more promising candidate for high-concentration glucose hydrogenation due to its high catalytic performance and superior stability.
ABSTRACT
Boron is in high demand in many sectors, yet there are significant flaws in current boron resource utilization. This study describes the synthesis of a boron adsorbent based on polypropylene (PP) melt-blown fiber using ultraviolet (UV)-induced grafting of Glycidyl methacrylate (GMA) onto PP melt-blown fiber, followed by an epoxy ring-opening reaction with N-methyl-D-glucosamine (NMDG). Using single-factor studies, grafting conditions such as the GMA concentration, benzophenone dose, and grafting duration were optimized. Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD), and water contact angle were used to characterize the produced adsorbent (PP-g-GMA-NMDG). The PP-g-GMA-NMDG adsorption process was examined by fitting the data with different adsorption settings and models. The results demonstrated that the adsorption process was compatible with the pseudo-second-order model and the Langmuir model; however, the internal diffusion model suggested that the process was impacted by both extra- and intra-membrane diffusion. According to thermodynamic simulations, the adsorption process was exothermic. At pH 6, the greatest saturation adsorption capacity to boron was 41.65 mg·g-1 for PP-g-GMA-NMDG. The PP-g-GMA-NMDG preparation process is a feasible and environmentally friendly route, and the prepared PP-g-GMA-NMDG has the advantages of high adsorption capacity, outstanding selectivity, good reproducibility, and easy recovery when compared to similar adsorbents, indicating that the reported adsorbent is promising for boron separation from water.
ABSTRACT
To evaluate the effects of long-term vitamin D supplementation on metabolic profiles in middle-aged to elderly patients with type 2 diabetes (T2D), a randomized controlled trial was conducted among patients with T2D aged 50-70 years. A total of 270 patients underwent randomization with 135 being allocated to the vitamin D group and 135 to the control group, and participants in the vitamin D group received oral vitamin D3 (800 IU/day) for 30 months. Serum 25(OH)D and metabolic variables were measured at baseline, and after 6, 12, 18, and 30 months of intervention. After 30 months, the vitamin D group showed a greater increase in serum 25(OH)D than the control group (12.39 ± 6.99 vs 5.35 ± 5.29 ng/ml, P < 0.001). Meanwhile, changes in the levels of fasting insulin, HOMA-IR, non-high-density-lipoprotein cholesterol (non-HDL-C), high-sensitivity C-reactive protein (hs-CRP), and uric acid differed significantly between the two groups (all P < 0.05). Stratified analysis indicated that change in uric acid differed significantly between the two groups in subgroup with baseline 25(OH)D ≥ 20 ng/ml (P = 0.042) or subgroup with female patients (P = 0.034). And the change in fasting blood glucose (FBG) differed significantly between the vitamin D group (-0.30 ± 2.52 mmol/L) and the control group (0.49 ± 1.78 mmol/L, P = 0.049) among patients achieving 25(OH)D concentrations of 30 ng/ml at the end of this trial. A significant difference in the change of triglyceride was observed between the two groups among patients with obesity at baseline [0.05(-0.59, 0.23) vs 0.41(-0.01, 0.80) mmol/L, P = 0.023]. These findings suggested that long-term vitamin D supplementation significantly reduced fasting insulin, HOMA-IR, and serum concentrations of non-HDL-C, hs-CRP, and uric acid among middle-aged to elderly patients with T2D. And vitamin D status, gender, and baseline obesity may modify the effects of vitamin D supplementation.
Subject(s)
Diabetes Mellitus, Type 2 , Insulin Resistance , Middle Aged , Aged , Humans , Female , Vitamin D/therapeutic use , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/metabolism , C-Reactive Protein/metabolism , Uric Acid , Blood Glucose/metabolism , Dietary Supplements , Vitamins/therapeutic use , Insulin/metabolism , Obesity , Metabolome , Double-Blind MethodABSTRACT
Objective@#To analyze the trend and characteristics of school tuberculosis epidemic in Shijiazhuang from 2011 to 2020, and to provide reference for school tuberculosis prevention and control.@*Methods@#Descriptive methods were used to analyze the epidemiological characteristics of tuberculosis among students and the epidemic situation of tuberculosis in schools in Shijiazhuang from 2011 to 2020. The χ 2 test and χ 2 trend test were used to analyze the characteristics and trend of school tuberculosis.@*Results@#A total of 4 896 cases of tuberculosis were registered among students in Shijiazhuang from 2011 to 2020. The average annual registered incidence rate of students was 24.69/100 000, and the difference in incidence rate was statistically significant ( χ 2=318.50, P <0.01) the overall registered incidence rate of tuberculosis among students in the past 10 years was on the rise ( χ 2 trend =87.79, P <0.01). Among the student cases, male accounted for 53.89%, female accounted for 46.11%. The age group of students aged >18 and above accounted for the largest proportion(50.35%), followed by the age group aged 16-18( 35.80 %). Most students cases occurred in April and September-November, with September the highest(12.03%). A total of 22 clustered outbreaks (174 cases) and the aggregate epidemic accounted for 3.55% of the total number of students with tuberculosis.@*Conclusion@#The prevention and control of tuberculosis epidemic in schools in Shijiazhuang should not be underestimated, and strengthen the supervision, management, publicity and education of students in key age groups to avoid clusters of outbreaks.
ABSTRACT
Inner ear gene therapy using adeno-associated viruses (AAVs) has been successfully applied to several mouse models of hereditary hearing loss to improve their auditory function. While most inner ear gene therapy studies have focused on the mechanosensory hair cells and supporting cells in the organ of Corti, the cochlear lateral wall and the endolymphatic sac have not garnered much attention. The cochlear lateral wall and the endolymphatic sac play critical roles in inner ear ionic and fluid homeostasis. Mutations in genes expressed in the cochlear lateral wall and the endolymphatic sac are present in a large percentage of patients with hereditary hearing loss. In this study, we examine the transduction patterns and efficiencies of conventional (AAV2 and AAV8) and synthetic (AAV2.7m8, AAV8BP2, and Anc80L65) AAVs in the mouse inner ear. We found that AAV8BP2 and AAV8 are capable of transducing the marginal cells and intermediate cells in the stria vascularis. These two AAVs can also transduce the epithelial cells of the endolymphatic sac. Our data suggest that AAV8BP2 and AAV8 are highly useful viral vectors for gene therapy studies targeting the cochlear lateral wall and the endolymphatic sac.
ABSTRACT
BACKGROUND: The study aims to investigate an optimal indicator for changing the filter during the continuous renal replacement therapy (CRRT) in intensive care unit (ICU) patients with acute kidney injury (AKI). METHODS: Patients with AKI requiring CRRT in an ICU were randomly divided into two groups for crossover trial, i.e., groups A and B. Patients in the group A were firstly treated with continuous veno-venous hemofiltration (CVVH), followed by continuous veno-venous hemodiafiltration (CVVHDF). Patients in the group B were firstly treated with CVVHDF followed by CVVH. Delivered doses of solutes with different molecular weights at the indicated time points between groups were compared. A correlation analysis between the delivered dose and pre-filter pressure (PPRE) and transmembrane pressure (PTM) was performed. Receiver operating characteristic (ROC) curves were constructed to evaluate the accuracy of PTM as an indicator for filter replacement. RESULTS: A total of 50 cases were analyzed, 27 in the group A and 23 in the group B. Delivered doses of different molecular-weight solutes significantly decreased before changing the filter in both modalities, compared with those at the initiation of treatment (all P<0.05). In the late stage of CRRT, the possible rebound of serum medium-molecular-weight solute concentration was observed. PTM was negatively correlated with the delivered dose of medium-molecular-weight solute in both modalities. The threshold for predicting the rebound of serum concentration of medium-molecular-weight solute by PTM was 146.5 mmHg (1 mmHg=0.133 kPa). CONCLUSIONS: The filter can be used as long as possible within the manufacturer's safe use time limits to remove small-molecular-weight solutes. PTM of 146.5 mmHg may be an optimal indicator for changing the filter in CRRT therapies to remove medium-molecular-weight solutes.
ABSTRACT
Several epidemiological studies have suggested an association between low vitamin D status and increased risk for type 2 diabetes (T2D). This study aimed to explore the dose-response relationship of serum 25-hydroxyvitamin D [25(OH)D] concentrations with incident T2D and the interaction between serum 25(OH)D with individual factors on T2D risk. A total of 1,926 adults without diabetes (mean age: 52.08 ± 13.82 years; 42% men) were prospectively followed for 36 months. Cox proportional hazards model and restricted cubic spline analysis were performed to assess the association and dose-response relationship between serum 25(OH)D and T2D incidence. Both additive and multiplicative interactions were calculated between serum 25(OH)D and individual factors. The net reclassification index (NRI) was used to evaluate the improvement of risk prediction of T2D by adding serum 25(OH)D to traditional risk factors. There were 114 new T2D cases over a mean follow-up of 36 months. Serum 25(OH)D was not associated with T2D incidence, and no significant dose-response relationship was found in the total population. However, stratified analyses suggested a non-linear inverse relationship among individuals with baseline fasting plasma glucose (FPG) <5.6 mmol/L (P overall = 0.061, P non-linear = 0.048). And a significant multiplicative interaction was observed between serum 25(OH)D and FPG on T2D risk (P = 0.005). In addition, we found a significant additive interaction of low serum 25(OH)D with older age (RERI = 0.897, 95% CI: 0.080-1.714; AP = 0.468, 95% CI: 0.054-0.881), male (AP = 0.441, 95% CI: 0.010-0.871), and insufficient physical activity (RERI = 0.875, 95% CI: 0.204-1.545; AP = 0.575, 95% CI: 0.039-1.111) on T2D risk. Significant additive interactions were also observed between vitamin D deficiency/insufficiency with male, overweight/obesity, and insufficient physical activity on T2D risk. Moreover, adding low serum 25(OH)D to a model containing established risk factors yielded significant improvements in the risk reclassification of T2D (NRI = 0.205, 95% CI: 0.019-0.391). Our results indicated a non-linear relationship of serum 25(OH)D concentrations with T2D risk among individuals with normal FPG and additive interactions of serum 25(OH)D with gender, overweight/obesity, and physical activity on T2D risk, suggesting the importance of outdoor exercise.
ABSTRACT
Patients with pulmonary tuberculosis (TB) undergoing anti-tuberculosis (anti-TB) treatment were previously reported to present gut bacterial microbiota dysbiosis, but the role of the mycobiota has not been reported. Here, we conducted a follow-up study of 29 naive TB patients who received first-line anti-TB drug treatment; we collected their fecal samples at different time points, as well as 22 fecal samples from healthy subjects. Fungal ITS2 and bacterial 16S rRNA amplicon sequencing were used to analyze the effects of active TB and anti-TB treatment on the gut microbiota. We found that naive TB patients had bacterial and fungal dysbiosis with altered community composition and a decreased density of the transkingdom correlation network. Anti-TB drug treatment significantly decreased the diversity of bacteria and fungi with altered composition. Notably, we observed that the abundance of Purpureocillium lilacinum tended to decrease and Nakaseomyces spp. tended to increase in the anti-TB treatment, and all of them had increased proportions in the three TB groups compared with healthy subjects. We found that the fungal-bacterial transkingdom network was severely altered in TB patients after 2 months of treatment, and new fungal-enriched connections that were not observed in other groups after 6 months of treatment. This study provides the first detailed analysis of dysbiosis of the gut mycobiota due to active TB and anti-TB treatment. The results suggest that fungi play an important role in the balance of the gut microbiota and may be associated with the progression of TB, influencing the microbiota and immunity homeostasis in those receiving anti-TB treatment. IMPORTANCE Numerous studies have shown that the gut bacterial microbiota is altered in active TB patients and that anti-TB drugs have profound and long-term impacts. However, as an integral part of the microbiota, fungi have rarely been studied. The need to investigate both the bacterial and fungal microbiota, as well as the relationship between them is apparent. The significance of our study is in our examination of the changes in the bacterial and fungal microbiota simultaneously in both active TB and patients receiving anti-TB treatment. We found that fungi play an important role in the bacterial-fungal transkingdom network, especially during the anti-TB therapy. These findings underscore the importance of fungi in gut microbiota dysbiosis during active TB and anti-TB treatment processes. In addition, our findings suggest it is meaningful to research potential adjunctive therapies that reduce fungal expansion and increase commensal bacterial abundance after anti-TB treatment, which would help the recovery of TB patients.
Subject(s)
Antitubercular Agents/therapeutic use , Dysbiosis/microbiology , Gastrointestinal Microbiome/drug effects , Tuberculosis, Pulmonary/microbiology , Adult , Antitubercular Agents/adverse effects , Bacteria/classification , Bacteria/drug effects , Bacteria/genetics , Bacteria/isolation & purification , Dysbiosis/drug therapy , Feces/microbiology , Female , Follow-Up Studies , Fungi/classification , Fungi/drug effects , Fungi/genetics , Fungi/isolation & purification , Humans , Male , Middle Aged , Tuberculosis, Pulmonary/drug therapyABSTRACT
Hearing loss is a common disability affecting the world's population today. While several studies have shown that inner ear gene therapy can be successfully applied to mouse models of hereditary hearing loss to improve hearing, most of these studies rely on inner ear gene delivery in the neonatal age, when mouse inner ear has not fully developed. However, the human inner ear is fully developed at birth. Therefore, in order for inner ear gene therapy to be successfully applied in patients with hearing loss, one must demonstrate that gene delivery can be safely and reliably performed in the mature mammalian inner ear. In this study, we examine the steps involved in posterior semicircular canal gene delivery in the adult mouse inner ear. We find that the duration of perilymphatic leakage and injection rate have a significant effect on the post-surgical hearing outcome. Our results show that although AAV2.7m8 has a lower hair cell transduction rate in adult mice compared to neonatal mice at equivalent viral load, AAV2.7m8 is capable of transducing the adult mouse inner and outer hair cells with high efficiency in a dose-dependent manner.
Subject(s)
Dependovirus/metabolism , Genetic Therapy/methods , Hair Cells, Auditory/metabolism , Semicircular Canals/surgery , Animals , Dependovirus/genetics , Gene Transfer Techniques , Genetic Therapy/adverse effects , Genetic Vectors/genetics , Genetic Vectors/metabolism , Hearing Loss , Mice, Inbred CBA , PerilymphABSTRACT
The neurotoxin MPP+ (1-methyl-4-phenylpyridinium ion) disrupts mitochondrial function leading to oxidative stress and neuronal death. Here we examine whether activation of the Keap1-Nrf2 cascade can protect SH-SY5Y neuroblastoma cells from MPP+-induced cytotoxicity. Treatment of SH-SY5Y cells with CBR-470-1, an inhibitor of the glycolytic enzyme phosphoglycerate kinase 1 (PGK1), leads to methylglyoxal modification of Keap1, Keap1-Nrf2 disassociation, and increased expression of Nrf2 responsive genes. Pretreatment with CBR-470-1 potently attenuated MPP+-induced oxidative injury and SH-SY5Y cell apoptosis. CBR-470-1 neuroprotection is dependent upon Nrf2, as Nrf2 shRNA or CRISPR/Cas9-mediated Nrf2 knockout, abolished CBR-470-1-induced SH-SY5Y cytoprotection against MPP+. Consistent with these findings, PGK1 depletion or knockout mimicked CBR-470-1-induced actions and rendered SH-SY5Y cells resistant to MPP+-induced cytotoxicity. Furthermore, activation of the Nrf2 cascade by CRISPR/Cas9-induced Keap1 knockout protected SH-SY5Y cells from MPP+. In Keap1 or PGK1 knockout SH-SY5Y cells,CBR-470-1 failed to offer further cytoprotection against MPP+. Collectively PGK1 inhibition by CBR-470-1 protects SH-SY5Y cells from MPP+ via activation of the Keap1-Nrf2 cascade.
Subject(s)
1-Methyl-4-phenylpyridinium/toxicity , NF-E2-Related Factor 2/agonists , Neuroprotective Agents/pharmacology , Neurotoxicity Syndromes/prevention & control , Phosphoglycerate Kinase/antagonists & inhibitors , Cell Line, Tumor , Gene Knockout Techniques , Humans , Kelch-Like ECH-Associated Protein 1/genetics , Kelch-Like ECH-Associated Protein 1/metabolism , Mitochondria/drug effects , Mitochondria/pathology , NF-E2-Related Factor 2/genetics , NF-E2-Related Factor 2/metabolism , Neuroprotective Agents/therapeutic use , Neurotoxicity Syndromes/etiology , Neurotoxicity Syndromes/pathology , Phosphoglycerate Kinase/genetics , Phosphoglycerate Kinase/metabolism , RNA, Small Interfering/metabolism , Signal Transduction/drug effects , Signal Transduction/geneticsABSTRACT
MPP+ (1-methyl-4-phenylpyridinium)-induced dopaminergic neuronal cell apoptosis is associated with sphingosine kinase 1 (SphK1) inhibition. We here tested the potential effect of microRNA-6862 (miR-6862), a novel SphK1-targeting miRNA, on MPP+-induced cytotoxicity in neuronal cells. MiR-6862 locates in the cytoplasm of SH-SY5Y neuronal cells. It directly binds to SphK1 mRNA. In SH-SY5Y cells and HCN-2 cells, ectopic overexpression of miR-6862 decreased SphK13'-untranslated region luciferase reporter activity and downregulated its expression. miR-6862 inhibition exerted opposite activity and elevated SphK1 expression. In neuronal cells, MPP+-induced cell death was significantly inhibited through miR-6862 inhibition. Conversely, ectopic overexpression of miR-6862 or CRISPR/Cas9-induced SphK1 knockout augmented MPP+-induced apoptosis in the neuronal cells. Importantly, antagomiR-6862 failed to inhibit MPP+-induced apoptosis in SphK1-knockout SH-SY5Y cells. These results suggest that inhibition of miR-6862 induces SphK1 elevation and protects neuronal cells from MPP+-induced cell death.
Subject(s)
Apoptosis/genetics , MicroRNAs/metabolism , Neurons/metabolism , Phosphotransferases (Alcohol Group Acceptor)/genetics , 1-Methyl-4-phenylpyridinium/toxicity , Antagomirs/pharmacology , Apoptosis/drug effects , CRISPR-Cas Systems , Cell Line, Tumor , Cell Survival , Gene Knockout Techniques , Humans , MicroRNAs/genetics , Neurons/drug effects , Parkinson Disease/genetics , Parkinson Disease/metabolism , Parkinsonian Disorders/genetics , Parkinsonian Disorders/metabolism , Phosphotransferases (Alcohol Group Acceptor)/metabolism , RNA, MessengerABSTRACT
Oxygen glucose deprivation-reoxygenation (OGD-R) causes the production of reactive oxygen species (ROS) and oxidative injury in neuronal cells. We tested the potential neuroprotective function of compound 13 (C13), a novel AMP-activated protein kinase (AMPK) activator, against OGD-R. We show that C13 pretreatment protected SH-SY5Y neuronal cells and primary hippocampal neurons from OGD-R. C13 activated AMPK signaling in SH-SY5Y cells and primary neurons. It significantly inhibited OGD-R-induced apoptosis activation in neuronal cells. Conversely, AMPKα1 shRNA or knockout reversed C13-mediated neuroprotection against OGD-R. C13 potently inhibited OGD-R-induced ROS production and oxidative stress in SH-SY5Y cells and primary neurons. Furthermore, C13 induced Keap1 downregulation and Nrf2 activation, causing Nrf2 stabilization, nuclear accumulation, and expression of Nrf2-dependent genes. Nrf2 silencing or knockout in SH-SY5Y cells abolished C13-mediated neuroprotection against OGD-R. In conclusion, C13 activates AMPK-Nrf2 signaling to protect neuronal cells from OGD-R.
Subject(s)
Adenylate Kinase/drug effects , NF-E2-Related Factor 2/metabolism , Neurons/drug effects , Neuroprotective Agents/pharmacology , Reperfusion Injury/metabolism , Adenylate Kinase/metabolism , Animals , Cell Line , Humans , Mice , Neurons/metabolism , Neurons/pathology , Oxidative Stress/drug effects , Oxidative Stress/physiology , Reperfusion Injury/pathology , Signal Transduction/drug effectsABSTRACT
In pathogenesis of Parkinson's disease (PD), mitochondrial dysfunction causes substantial reactive oxygen species (ROS) production and oxidative stress, leading to dopaminergic (DA) neuronal cell death. Mitochondrial toxins, including MPP+ (1-methyl-4-phenylpyridinium ion) and rotenone, induce oxidative injury in cultured DA neuronal cells. The current study tested the potential effect of SC79, a first-in-class small-molecule Akt activator, against the process. In SH-SY5Y cells and primary murine DA neurons, SC79 significantly attenuated MPP+- and rotenone-induced viability reduction, cell death, and apoptosis. SC79 activated Akt signaling in DA neuronal cells. Akt inhibition (by LY294002 and MK-2206) or CRISPR-Cas9-mediated Akt1 knockout completely abolished SC79-induced DA neuroprotection against MPP+. Further studies demonstrated that SC79 attenuated MPP+- and rotenone-induced ROS production, mitochondrial depolarization, and lipid peroxidation in SH-SY5Y cells and primary DA neurons. Moreover, upregulation of Nrf2-dependent genes (HO1 and NQO1) and Nrf2 protein stabilization were detected in SC79-treated SH-SY5Y cells and primary DA neurons. Together we show that SC79 protects DA neuronal cells from mitochondrial toxins possibly via activation of Akt-Nrf2 signaling.
Subject(s)
1-Methyl-4-phenylpyridinium/toxicity , Acetates/pharmacology , Benzopyrans/pharmacology , Dopaminergic Neurons/pathology , Enzyme Activators/pharmacology , Neuroprotective Agents/pharmacology , Proto-Oncogene Proteins c-akt/metabolism , Rotenone/toxicity , Animals , Apoptosis/drug effects , Cell Line, Tumor , Dopaminergic Neurons/drug effects , Humans , Mice, Inbred C57BL , Neuroprotection/drug effects , Oxidative Stress/drug effectsABSTRACT
Dexmedetomidine (Dex) is a sedative and analgesic agent that is widely administered to patients admitted to the intensive care unit, and has been demonstrated to result in hypothermia. Many patients have been revealed to benefit from therapeutic hypothermia, which can mitigate cerebral ischemia/reperfusion (I/R) injury following successful cardiopulmonary resuscitation. However, studies investigating the efficacy of Dex in I/R treatment is lacking. The present study aimed to investigate the efficacy of Dex in mitigating neuronal damage, and to determine the possible mechanism of its effects in a rat model of cardiac arrest (CA). CA was induced in Sprague-Dawley rats by asphyxiation for 5 min. Following successful resuscitation, the surviving rats were randomly divided into two treatment groups; one group was intraperitoneally administered with Dex (D group), whereas the control group was treated with normal saline (N group). Critical parameters, including core temperature and blood pressure were monitored following return of spontaneous circulation (ROSC). Arterial blood samples were collected at 10 min after surgery (baseline) 30 and 120 min post-ROSC; and neurological deficit scores (NDS) of the rats were taken 12 or 24 h after ROSC prior to euthanasia. The hippocampal tissue was then removed for analysis by histology, electron microscopy and western blotting. Rats in the D group exhibited a lower core temperature and higher NDS scores compared with the N group (P<0.05). In addition, Dex injection resulted in reduced expression of apoptotic and autophagy-associated factors in the hippocampus (P<0.05). Dex treatment induced hypothermia and improved neurological function in rats after ROSC following resuscitation from CA by inhibiting neuronal apoptosis and reducing autophagy, which suggested that Dex may be a potential therapy option for patients with CA.
ABSTRACT
OBJECTIVE: To investigate the effect of III-type phosphatidylinositide 3 kinase (PI3K) pathway adjusting autophagy on brain damage mechanism after cardiopulmonary resuscitation (CPR) and hypothermia treatment. METHODS: The asphyxia induce cardiac arrest-CPR model was reproduced on healthy male Sprague-Dawley (SD) rats. Sixty rats after restoration of spontaneous circulation (ROSC) were randomly divided into normothermia group, therapeutic hypothermia group and PI3K inhibitor 3-methyl adenine (3-MA) pretreatment group, differentiated by 24 hours and 48 hours after ROSC. Each group had 10 rats at each time point. The anal temperature in the normothermia group was maintained at (37.0±0.2) centigrade, and the rats in the hypothermia group were given cooling treatment immediately after ROSC, and the target rectal temperature was 32-34 centigrade. In the 3-MA pretreatment group, 10 mmol/L 3-MA 5 µL was injected into the ventricle 20 minutes before asphyxia, and other groups were given the same amount of normal saline. Ten rats without CPR were included in Sham group only received anesthesia and catheterization. The rats were sacrificed at 24 hours and 48 hours after ROSC respectively, and the brain tissues were harvested, the brain water content (BWC) was measured by dry-wet weight method. Western Blot was used to determine the autophagy related proteins Beclin-1 and microtubule-associated protein 1 light chain 3 (LC3), apoptosis related proteins Bcl-2 and caspase-3, and the III-type PI3K pathway proteins Vps34 and Atg14. Ultrastructural changes in brain tissue were observed with transmission electron microscope. Neurological deficit scores (NDS) was obtained in each group at 48 hours after ROSC. RESULTS: Compared with Sham group, the cortex at 24 hours after ROSC in normothermic group showed obvious edema, apoptosis and autophagy began to appear under transmission electron microscope, and the expressions of autophagy, apoptosis and III- type PI3K-related proteins in brain tissue were significantly increased in a time-dependent manner, and the neurological function at 48 hours after ROSC was significantly damaged. After hypothermia intervention, brain edema of rats was significantly reduced, no obvious apoptosis was found, but autophagy was increased, the expressions of autophagy-related proteins Vps34, Atg14 and III-type PI3K-related proteins Beclin-1 and LC3 at 48 hours after ROSC were further higher than those of normothermic group (Vps34/GAPDH: 0.25±0.03 vs. 0.15±0.04, Atg14/GAPDH: 0.12±0.03 vs. 0.05±0.04, Beclin-1/GAPDH: 0.060±0.002 vs. 0.018±0.002, LC3 -II/GAPDH: 0.160±0.010 vs. 0.050±0.010, all P < 0.05), the expressions of apoptosis related proteins Bcl-2 and caspase-3 were significantly lowered (Bcl-2/GAPDH: 0.05±0.03 vs. 0.20±0.04, caspase-3/GAPDH: 0.050±0.002 vs. 0.140±0.015, both P < 0.05), neurological function was significantly improved (NDS: 157±85 vs. 343±198, P < 0.05). Pretreatment with 3-MA inhibited the protective effect of hypothermia on brain tissues. The expressions of Vps34, Atg14, Beclin-1 and LC3 in brain tissues at 48 hours after ROSC in 3-MA pretreatment group was significantly lower than those in the hypothermia group (Vps34/GAPDH: 0.18±0.03 vs. 0.25±0.03, Atg14/GAPDH: 0.07±0.04 vs. 0.12±0.03, Beclin-1/GAPDH: 0.015±0.003 vs. 0.060±0.002, LC3-II/GAPDH: 0.045±0.030 vs. 0.160±0.010, all P < 0.05), the expressions of Bcl-2 and caspase-3 were significantly increased (Bcl-2/GAPDH: 0.15±0.04 vs. 0.05±0.03, caspase-3/GAPDH: 0.120±0.015 vs. 0.050±0.002, both P < 0.05), and NDS score was significantly increased (341±208 vs. 157±85, P < 0.05). CONCLUSIONS: Hypothermia treatment reduced brain edema and ameliorated brain function after CPR, which might be related to increase autophagy and inhibit apoptosis adjustment by activating III-type PI3K pathway.