Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 1.339
1.
Sci Rep ; 14(1): 10464, 2024 May 07.
Article En | MEDLINE | ID: mdl-38714792

In order to investigate the failure modes and instability mechanism of fractured rock. Uniaxial compression tests were conducted on sandstone specimens with different dip angles. Based on rock energy dissipation theory and fractal theory, the energy evolution characteristics and fragmentation fractal characteristics in the process of deformation and failure of specimens were analyzed. The results show that the peak strength and elastic modulus of fractured rock mass are lower than those of intact samples, and both show an exponential increase with the increase of fracture dip angle. The energy evolution laws of different fracture specimens are roughly similar and can be classified into four stages based on the stress-strain curve: pressure-tight, elastic, plastic, and post-destructive. The total strain energy, elastic strain energy, and dissipated strain energy of the specimen at the peak stress point increased exponentially with crack inclination, and the dissipated strain energy and compressive strength conformed to a power function growth relationship. The distribution of the fragments after the failure of the fracture sample has fractal characteristics, and the fractal dimension increases with the increase of the fracture dip angle. In addition, the higher the compressive strength of the specimen, the greater the energy dissipation, the more serious the degree of fragmentation, and the greater the fractal dimension. The data fitting further shows that there is a power function relationship between the dissipated strain energy and the fractal dimension. The research results can provide a theoretical basis for the stability of rock mass engineering and structural deformation control.

2.
Sci Rep ; 14(1): 10658, 2024 05 09.
Article En | MEDLINE | ID: mdl-38724553

This study aimed to investigate the effects of exercise on excessive mitochondrial fission, insulin resistance, and inflammation in the muscles of diabetic rats. The role of the irisin/AMPK pathway in regulating exercise effects was also determined. Thirty-two 8-week-old male Wistar rats were randomly divided into four groups (n = 8 per group): one control group (Con) and three experimental groups. Type 2 diabetes mellitus (T2DM) was induced in the experimental groups via a high-fat diet followed by a single intraperitoneal injection of streptozotocin (STZ) at a dosage of 30 mg/kg body weight. After T2DM induction, groups were assigned as sedentary (DM), subjected to 8 weeks of treadmill exercise training (Ex), or exercise training combined with 8-week cycloRGDyk treatment (ExRg). Upon completion of the last training session, all rats were euthanized and samples of fasting blood and soleus muscle were collected for analysis using ELISA, immunofluorescence, RT-qPCR, and Western blotting. Statistical differences between groups were analyzed using one-way ANOVA, and differences between two groups were assessed using t-tests. Our findings demonstrate that exercise training markedly ameliorated hyperglycaemia, hyperlipidaemia, and insulin resistance in diabetic rats (p < 0.05). It also mitigated the disarranged morphology and inflammation of skeletal muscle associated with T2DM (p < 0.05). Crucially, exercise training suppressed muscular excessive mitochondrial fission in the soleus muscle of diabetic rats (p < 0.05), and enhanced irisin and p-AMPK levels significantly (p < 0.05). However, exercise-induced irisin and p-AMPK expression were inhibited by cycloRGDyk treatment (p < 0.05). Furthermore, the administration of CycloRGDyk blocked the effects of exercise training in reducing excessive mitochondrial fission and inflammation in the soleus muscle of diabetic rats, as well as the positive effects of exercise training on improving hyperlipidemia and insulin sensitivity in diabetic rats (p < 0.05). These results indicate that regular exercise training effectively ameliorates insulin resistance and glucolipid metabolic dysfunction, and reduces inflammation in skeletal muscle. These benefits are partially mediated by reductions in mitochondrial fission through the irisin/AMPK signalling pathway.


AMP-Activated Protein Kinases , Diabetes Mellitus, Experimental , Fibronectins , Inflammation , Insulin Resistance , Mitochondrial Dynamics , Muscle, Skeletal , Physical Conditioning, Animal , Rats, Wistar , Animals , Fibronectins/metabolism , Male , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/therapy , Rats , Muscle, Skeletal/metabolism , Inflammation/metabolism , AMP-Activated Protein Kinases/metabolism , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/therapy , Signal Transduction , Streptozocin
3.
MedComm (2020) ; 5(5): e561, 2024 May.
Article En | MEDLINE | ID: mdl-38721005

Oral lichen planus (OLP) is a common chronic inflammatory disease of the oral mucosa, the mechanism of its inflammatory progression has not yet been fully elucidated. PA28γ plays a significant role in a variety of immune-related diseases. However, the exact role of PA28γ in the pathogenesis of OLP remains unclear. Here, we demonstrated that PA28γ is overexpressed in epithelial cells and inflammatory cells of OLP tissues but has no significant relationship with OLP subtypes. Functionally, keratinocytes with high PA28γ expression could induce dendritic cell (DC) maturation and promote the T-cell differentiation into Th1 cells in response to the immune response. In addition, we found that a high level of PA28γ expression is associated with high numbers of infiltrating mature DCs and activated T-cells in OLP tissues. Mechanistically, keratinocytes with high PA28γ expression could promote the secretion of C-C motif chemokine (CCL)5, blocking CCL5 or/and its receptor CD44 could inhibit the induction of T-cell differentiation by keratinocytes with high PA28γ expression. In conclusion, we reveal that keratinocytes with high expression of PA28γ in OLP can induce DC maturation and promote T-cell differentiation through the CCL5-CD44 pathway, providing previously unidentified mechanistic insights into the mechanism of inflammatory progression in OLP.

4.
J Hazard Mater ; 472: 134440, 2024 Apr 27.
Article En | MEDLINE | ID: mdl-38723480

N6-methyladenosine (m6A) is the most common form of internal post-transcriptional methylation observed in eukaryotic mRNAs. The abnormally increased level of m6A within the cells can be catalyzed by specific demethylase fat mass and obesity-associated protein (FTO) and stay in a dynamic and reversible state. However, whether and how FTO regulates oxidative damage via m6A modification remain largely unclear. Herein, by using both in vitro and in vivo models of oxidative damage induced by arsenic, we demonstrated for the first time that exposure to arsenic caused a significant increase in SUMOylation of FTO protein, and FTO SUMOylation at lysine (K)- 216 site promoted the down-regulation of FTO expression in arsenic target organ lung, and therefore, remarkably elevating the oxidative damage via an m6A-dependent pathway by its specific m6A reader insulin-like growth factor-2 mRNA-binding protein-3 (IGF2BP3). Consequently, these findings not only reveal a novel mechanism underlying FTO-mediated oxidative damage from the perspective of m6A, but also imply that regulation of FTO SUMOylation may serve as potential approach for treatment of oxidative damage.

5.
J Exp Med ; 221(7)2024 Jul 01.
Article En | MEDLINE | ID: mdl-38695876

Platinum-based chemotherapy drugs can lead to the development of anorexia, a detrimental effect on the overall health of cancer patients. However, managing chemotherapy-induced anorexia and subsequent weight loss remains challenging due to limited effective therapeutic strategies. Growth differentiation factor 15 (GDF15) has recently gained significant attention in the context of chemotherapy-induced anorexia. Here, we report that hepatic GDF15 plays a crucial role in regulating body weight in response to chemo drugs cisplatin and doxorubicin. Cisplatin and doxorubicin treatments induce hepatic Gdf15 expression and elevate circulating GDF15 levels, leading to hunger suppression and subsequent weight loss. Mechanistically, selective activation by chemotherapy of hepatic IRE1α-XBP1 pathway of the unfolded protein response (UPR) upregulates Gdf15 expression. Genetic and pharmacological inactivation of IRE1α is sufficient to ameliorate chemotherapy-induced anorexia and body weight loss. These results identify hepatic IRE1α as a molecular driver of GDF15-mediated anorexia and suggest that blocking IRE1α RNase activity offers a therapeutic strategy to alleviate the adverse anorexia effects in chemotherapy.


Anorexia , Doxorubicin , Endoribonucleases , Growth Differentiation Factor 15 , Liver , Protein Serine-Threonine Kinases , Signal Transduction , Unfolded Protein Response , Weight Loss , X-Box Binding Protein 1 , Growth Differentiation Factor 15/metabolism , Growth Differentiation Factor 15/genetics , Endoribonucleases/metabolism , Endoribonucleases/genetics , Animals , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/genetics , X-Box Binding Protein 1/metabolism , X-Box Binding Protein 1/genetics , Anorexia/metabolism , Anorexia/chemically induced , Weight Loss/drug effects , Signal Transduction/drug effects , Liver/metabolism , Liver/drug effects , Liver/pathology , Mice , Unfolded Protein Response/drug effects , Doxorubicin/adverse effects , Cisplatin/adverse effects , Mice, Inbred C57BL , Antineoplastic Agents/adverse effects , Male , Humans
6.
Nat Commun ; 15(1): 3698, 2024 May 01.
Article En | MEDLINE | ID: mdl-38693102

Mouse models of autosomal dominant polycystic kidney disease (ADPKD) show that intact primary cilia are required for cyst growth following the inactivation of polycystin-1. The signaling pathways underlying this process, termed cilia-dependent cyst activation (CDCA), remain unknown. Using translating ribosome affinity purification RNASeq on mouse kidneys with polycystin-1 and cilia inactivation before cyst formation, we identify the differential 'CDCA pattern' translatome specifically dysregulated in kidney tubule cells destined to form cysts. From this, Glis2 emerges as a candidate functional effector of polycystin signaling and CDCA. In vitro changes in Glis2 expression mirror the polycystin- and cilia-dependent changes observed in kidney tissue, validating Glis2 as a cell culture-based indicator of polycystin function related to cyst formation. Inactivation of Glis2 suppresses polycystic kidney disease in mouse models of ADPKD, and pharmacological targeting of Glis2 with antisense oligonucleotides slows disease progression. Glis2 transcript and protein is a functional target of CDCA and a potential therapeutic target for treating ADPKD.


Cilia , Disease Models, Animal , Polycystic Kidney, Autosomal Dominant , Signal Transduction , TRPP Cation Channels , Animals , Humans , Male , Mice , Cilia/metabolism , Kidney/metabolism , Kidney/pathology , Mice, Inbred C57BL , Mice, Knockout , Oligonucleotides, Antisense/pharmacology , Polycystic Kidney Diseases/metabolism , Polycystic Kidney Diseases/genetics , Polycystic Kidney Diseases/pathology , Polycystic Kidney, Autosomal Dominant/metabolism , Polycystic Kidney, Autosomal Dominant/genetics , Polycystic Kidney, Autosomal Dominant/pathology , Polycystic Kidney, Autosomal Dominant/drug therapy , TRPP Cation Channels/metabolism , TRPP Cation Channels/genetics
7.
Nat Med ; 2024 May 13.
Article En | MEDLINE | ID: mdl-38740994

Emotional distress (ED), commonly characterized by symptoms of depression and/or anxiety, is prevalent in patients with cancer. Preclinical studies suggest that ED can impair antitumor immune responses, but few clinical studies have explored its relationship with response to immune checkpoint inhibitors (ICIs). Here we report results from cohort 1 of the prospective observational STRESS-LUNG study, which investigated the association between ED and clinical efficacy of first-line treatment of ICIs in patients with advanced non-small-cell lung cancer. ED was assessed by Patient Health Questionnaire-9 and Generalized Anxiety Disorder 7-item scale. The study included 227 patients with 111 (48.9%) exhibiting ED who presented depression (Patient Health Questionnaire-9 score ≥5) and/or anxiety (Generalized Anxiety Disorder 7-item score ≥5) symptoms at baseline. On the primary endpoint analysis, patients with baseline ED exhibited a significantly shorter median progression-free survival compared with those without ED (7.9 months versus 15.5 months, hazard ratio 1.73, 95% confidence interval 1.23 to 2.43, P = 0.002). On the secondary endpoint analysis, ED was associated with lower objective response rate (46.8% versus 62.1%, odds ratio 0.54, P = 0.022), reduced 2-year overall survival rate of 46.5% versus 64.9% (hazard ratio for death 1.82, 95% confidence interval 1.12 to 2.97, P = 0.016) and detriments in quality of life. The exploratory analysis indicated that the ED group showed elevated blood cortisol levels, which was associated with adverse survival outcomes. This study suggests that there is an association between ED and worse clinical outcomes in patients with advanced non-small-cell lung cancer treated with ICIs, highlighting the potential significance of addressing ED in cancer management. ClinicalTrials.gov registration: NCT05477979 .

8.
Int J Biol Macromol ; 267(Pt 2): 131645, 2024 May.
Article En | MEDLINE | ID: mdl-38631582

Diet-induced obesity can cause metabolic syndromes. The critical link in disease progression is adipose tissue macrophage (ATM) recruitment, which drives low-level inflammation, triggering adipocyte dysfunction. It is unclear whether ubiquitin-specific proteinase 14 (USP14) affects metabolic disorders by mediating adipose tissue inflammation. In the present study, we showed that USP14 is highly expressed in ATMs of obese human patients and diet-induced obese mice. Mouse USP14 overexpression aggravated obesity-related insulin resistance by increasing the levels of pro-inflammatory ATMs, leading to adipose tissue inflammation, excessive lipid accumulation, and hepatic steatosis. In contrast, USP14 knockdown in adipose tissues alleviated the phenotypes induced by a high-fat diet. Co-culture experiments showed that USP14 deficiency in macrophages led to decreased adipocyte lipid deposition and enhanced insulin sensitivity, suggesting that USP14 plays an important role in ATMs. Mechanistically, USP14 interacted with TNF receptor-associated 6, preventing K48-linked ubiquitination as well as proteasome degradation, leading to increased pro-inflammatory polarization of macrophages. In contrast, the pharmacological inhibition of USP14 significantly ameliorated diet-induced hyperlipidemia and insulin resistance in mice. Our results demonstrated that macrophage USP14 restriction constitutes a key constraint on the pro-inflammatory M1 phenotype, thereby inhibiting obesity-related metabolic diseases.


Adipose Tissue , Diet, High-Fat , Insulin Resistance , Macrophages , Obesity , Ubiquitin Thiolesterase , Animals , Obesity/metabolism , Ubiquitin Thiolesterase/metabolism , Ubiquitin Thiolesterase/genetics , Macrophages/metabolism , Mice , Humans , Adipose Tissue/metabolism , Diet, High-Fat/adverse effects , Male , Adipocytes/metabolism , Inflammation/metabolism , Ubiquitination , Mice, Inbred C57BL
9.
J Clin Pharmacol ; 2024 Apr 23.
Article En | MEDLINE | ID: mdl-38654529

Voriconazole is the first-line treatment for invasive aspergillosis. Its pharmacokinetics exhibit considerable inter- and intra-individual variability. The purpose of this study was to investigate the effects of CYP2C19, CYP2C9, CYP3A4, and FMO3 genetic polymorphisms and sex on the pharmacokinetics of voriconazole in healthy Chinese adults receiving single-dose and multiple-dose voriconazole, to provide a reference for its clinical individualized treatment. A total of 123 healthy adults were enrolled in the study, with 108 individuals and 15 individuals in the single-dose and multiple-dose doses, respectively. Plasma voriconazole concentrations were measured using a validated LC-MS/MS method, and pharmacokinetics parameters were calculated using the non-compartmental method with WinNonlin 8.2. CYP2C19, CYP2C9, CYP3A4, and FMO3 single-nucleotide polymorphisms were sequenced using the Illumina Hiseq X-Ten platform. The results suggested that CYP2C19 genetic polymorphisms significantly affected the pharmacokinetics of voriconazole at single doses of 4, 6, and 8 mg/kg and multiple doses of voriconazole. CYP3A4 rs2242480 had a significant effect on AUC0-∞ (area under the plasma concentration-time curve from time 0 to infinity) and MRT (mean residence time) of voriconazole at a single dose of 4 mg/kg in CYP2C19 extensive metabolizer. Regardless of the CYP2C19 genotype, CYP2C9 rs1057910 and FMO3 rs2266780 were not associated with the pharmacokinetics of voriconazole at three single-dose levels or multiple doses. No significant differences in most voriconazole pharmacokinetics parameters were noted between male and female participants after single and multiple dosing. For patients receiving voriconazole treatment, CYP2C19 genetic polymorphisms should be genotyped for its precision administration. In contrast, based on our study of healthy Chinese adults, it seems unnecessary to consider the effects of CYP2C9, CYP3A4, and FMO3 genetic polymorphisms on voriconazole pharmacokinetics.

10.
Cancer Med ; 13(7): e7123, 2024 Apr.
Article En | MEDLINE | ID: mdl-38618943

OBJECTIVE: To evaluate the incidence, clinical laboratory characteristics, and gene mutation spectrum of Ph-negative MPN patients with atypical variants of JAK2, MPL, or CALR. METHODS: We collected a total of 359 Ph-negative MPN patients with classical mutations in driver genes JAK2, MPL, or CALR, and divided them into two groups based on whether they had additional atypical variants of driver genes JAK2, MPL, or CALR: 304 patients without atypical variants of driver genes and 55 patients with atypical variants of driver genes. We analyzed the relevant characteristics of these patients. RESULTS: This study included 359 patients with Ph-negative MPNs with JAK2, MPL, or CALR classical mutations and found that 55 (15%) patients had atypical variants of JAK2, MPL, or CALR. Among them, 28 cases (51%) were male, and 27 (49%) were female, with a median age of 64 years (range, 21-83). The age of ET patients with atypical variants was higher than that of ET patients without atypical variants [70 (28-80) vs. 61 (19-82), p = 0.03]. The incidence of classical MPL mutations in ET patients with atypical variants was higher than in ET patients without atypical variants [13.3% (2/15) vs. 0% (0/95), p = 0.02]. The number of gene mutations in patients with atypical variants of driver genes PV, ET, and Overt-PMF is more than in patients without atypical variants of PV, ET, and Overt-PMF [PV: 3 (2-6) vs. 2 (1-7), p < 0.001; ET: 4 (2-8) vs. 2 (1-7), p < 0.05; Overt-PMF: 5 (2-9) vs. 3 (1-8), p < 0.001]. The incidence of SH2B3 and ASXL1 mutations were higher in MPN patients with atypical variants than in those without atypical variants (SH2B3: 16% vs. 6%, p < 0.01; ASXL1: 24% vs. 13%, p < 0.05). CONCLUSION: These data indicate that classical mutations of JAK2, MPL, and CALR may not be completely mutually exclusive with atypical variants of JAK2, MPL, and CALR. In this study, 30 different atypical variants of JAK2, MPL, and CALR were identified, JAK2 G127D being the most common (42%, 23/55). Interestingly, JAK2 G127D only co-occurred with JAK2V617F mutation. The incidence of atypical variants of JAK2 in Ph-negative MPNs was much higher than that of the atypical variants of MPL and CALR. The significance of these atypical variants will be further studied in the future.


Laboratories, Clinical , Transcription Factors , Humans , Female , Male , Young Adult , Adult , Middle Aged , Aged , Aged, 80 and over , Mutation , Receptors, Thrombopoietin/genetics , Janus Kinase 2/genetics
11.
Microbiol Resour Announc ; : e0010724, 2024 Apr 23.
Article En | MEDLINE | ID: mdl-38651915

Microbes play a significant role in the cleanup of xenobiotic contaminants. Based on metagenomes derived from long-term enrichment cultures grown on xenobiotic solvents, we report 166 metagenome-assembled genomes, of which 137 are predicted to be more than 90% complete. These genomes broaden the representation of xenobiotic degraders.

12.
Lipids Health Dis ; 23(1): 101, 2024 Apr 10.
Article En | MEDLINE | ID: mdl-38600581

BACKGROUND: The objective was to investigate the efficacy of different doses of levothyroxine therapy among pregnant women exhibiting high-normal thyroid stimulating hormone levels and positive thyroid peroxidase antibodies throughout the first half of pregnancy. METHODS: Pregnant women exhibiting high-normal thyroid stimulating hormone levels and thyroid peroxidase antibodies positivity throughout the initial half of pregnancy were selected from January 2021 to September 2023. Based on the different doses of levothyroxine, the pregnant women were categorized into the nonintervention group (G0, 122 women), 25 µg levothyroxine intervention group (G25, 69 women), and 50 µg levothyroxine intervention group (G50, 58 women). Serum parameters, gastrointestinal symptoms, small intestinal bacterial overgrowth (SIBO), maternal and neonatal outcomes were compared after the intervention among the three groups. RESULTS: After the intervention, in the G25 and G50 groups, the thyroid stimulating hormone, triglyceride and low-density lipoprotein levels were notably less in contrast to those in the G0 group (P < 0.05). The rates of abdominal distension and SIBO in the G25 and G50 groups were notably lower in contrast to the G0 group (P = 0.043 and 0.040, respectively). The G50 group had a lower rate of spontaneous abortion and premature membrane rupture than the G0 group (P = 0.01 and 0.015, respectively). Before 11+ 2 weeks of gestation and at thyroid peroxidase antibodies levels ≥ 117 IU/mL, in contrast to the G0 group, the G50 group experienced a decreased rate of spontaneous abortion (P = 0.008). The G50 group had significantly higher newborn weight than the G0 group (P = 0.014), as well as a notably longer newborn length than the G0 and G25 groups (P = 0.005). CONCLUSIONS: For pregnant women with high-normal thyroid stimulating hormone levels and thyroid peroxidase antibodies positive during the first half of pregnancy, supplementation with 50 µg levothyroxine was more effective in improving their blood lipid status and gastrointestinal symptoms, reducing the incidence of SIBO and premature rupture of membranes, and before 11+2 weeks, TPOAb ≥ 117 IU/mL proved more beneficial in mitigating the risk of spontaneous abortion.


Abortion, Spontaneous , Thyroxine , Infant, Newborn , Female , Pregnancy , Humans , Thyroxine/therapeutic use , Pregnant Women , Iodide Peroxidase , Autoantibodies , Thyrotropin
14.
Micromachines (Basel) ; 15(4)2024 Mar 30.
Article En | MEDLINE | ID: mdl-38675285

Ozone (O3) is a critical gas in various industrial applications, particularly in semiconductor manufacturing, where it is used for wafer cleaning and oxidation processes. Accurate and reliable detection of ozone concentration is essential for process control, ensuring product quality, and safeguarding workplace safety. By studying the UV absorption characteristics of O3 and combining the specific operational needs of semiconductor process gas analysis, a pressure-insensitive ozone gas sensor has been developed. In its optical structure, a straight-through design without corners was adopted, achieving a coupling efficiency of 52% in the gas chamber. This device can operate reliably in a temperature range from 0 °C to 50 °C, with only ±0.3% full-scale error across the entire temperature range. The sensor consists of a deep ultraviolet light-emitting diode in a narrow spectrum centered at 254 nm, a photodetector, and a gas chamber, with dimensions of 85 mm × 25 mm × 35 mm. The performance of the sensor has been meticulously evaluated through simulation and experimental analysis. The sensor's gas detection accuracy is 750 ppb, with a rapid response time (t90) of 7 s, and a limit of detection of 2.26 ppm. It has the potential to be applied in various fields for ozone monitoring, including the semiconductor industry, water treatment facilities, and environmental research.

15.
ChemSusChem ; : e202400570, 2024 Apr 12.
Article En | MEDLINE | ID: mdl-38610068

Reasonable design of low-cost, high-efficiency and stable bifunctional oxygen electrocatalysts is of great significance to improve the reaction efficiency of Zn-air batteries, which is still a huge challenge. Here, we report a highly efficient bifunctional oxygen electrocatalyst with three-dimensional (3D) N-doped graphene network-supported cobalt and cobalt oxide nanoparticles (Co/CoO-NG), which can be in situ synthesized by inducing metal ions on metal plates via graphene oxide as an inducer. This 3D network structure and open active center show excellent bifunctional oxygen electrocatalytic activity under alkaline conditions, and can be used as an air electrode in rechargeable Zn-air batteries, with significantly better power density (244.28 mW cm-2) and stability (over 340 h) than commercial Pt/C + RuO2 mixtures. This work is conducive to advancing the practical application of graphene-based materials as air electrodes for rechargeable zinc-air batteries.

16.
Polymers (Basel) ; 16(7)2024 Apr 03.
Article En | MEDLINE | ID: mdl-38611236

Aliphatic polyester is an important polyester material with good biocompatibility and degradability, which can be synthesized through ring-opening alternating copolymerization (ROAC) of epoxides and anhydrides. Herein, density functional theory (DFT) is used to explore the mechanism of ROAC of epoxides (propylene oxide (PO), styrene oxide (SO), epichlorohydrin (ECH), and cyclohexane oxide (CHO)) and phthalic anhydride (PA) catalyzed by bis(triphenylphosphine) ammonium chloride (PPNCl) and ureas. It was found that the ring-opening polymerization (ROP) of epoxides is the rate-controlling step, and the benzyl alcohol (BnOH) as the initiator has little effect on the polymerization activity, which was consistent with previous experimental results. Calculated comparisons of the ROAC activity of CHO/PA catalyzed by four different ureas indicate that as the Lewis acidity of the urea increased, the energy barriers of the copolymerization increased and the activity decreased. The main reason was that the strong hydrogen-bonding interactions stabilized the key intermediate of the rate-controlling step and inhibited subsequent monomer insertion. Based on this, a series of new ureas with higher catalytic activity were designed by introducing electron-donating substituents. In SO polymerization, increasing the Lewis acidity of urea can improve the SO regioselectivity. In addition, the monomer ECH with CH2Cl shows higher activity of ROAC than PO and SO, which could be ascribed to the fact that the strong electron-withdrawing Cl atom stabilizes the transition state in the rate-controlling step and reduces the reaction energy barrier.

17.
Neural Regen Res ; 19(12): 2637-2648, 2024 Dec 01.
Article En | MEDLINE | ID: mdl-38595282

Epilepsy can be defined as a dysfunction of the brain network, and each type of epilepsy involves different brain-network changes that are implicated differently in the control and propagation of interictal or ictal discharges. Gaining more detailed information on brain network alterations can help us to further understand the mechanisms of epilepsy and pave the way for brain network-based precise therapeutic approaches in clinical practice. An increasing number of advanced neuroimaging techniques and electrophysiological techniques such as diffusion tensor imaging-based fiber tractography, diffusion kurtosis imaging-based fiber tractography, fiber ball imaging-based tractography, electroencephalography, functional magnetic resonance imaging, magnetoencephalography, positron emission tomography, molecular imaging, and functional ultrasound imaging have been extensively used to delineate epileptic networks. In this review, we summarize the relevant neuroimaging and neuroelectrophysiological techniques for assessing structural and functional brain networks in patients with epilepsy, and extensively analyze the imaging mechanisms, advantages, limitations, and clinical application ranges of each technique. A greater focus on emerging advanced technologies, new data analysis software, a combination of multiple techniques, and the construction of personalized virtual epilepsy models can provide a theoretical basis to better understand the brain network mechanisms of epilepsy and make surgical decisions.

18.
Neurochem Int ; 176: 105725, 2024 Jun.
Article En | MEDLINE | ID: mdl-38561151

Epilepsy constitutes a global health concern, affecting millions of individuals and approximately one-third of patients exhibit drug resistance. Recent investigations have revealed alterations in cerebral iron content in both epilepsy patients and animal models. However, the extant literature lacks a comprehensive exploration into the ramifications of modulating iron homeostasis as an intervention in epilepsy. This study investigated the impact of deferasirox, a iron ion chelator, on epilepsy. This study unequivocally substantiated the antiepileptic efficacy of deferasirox in a kainic acid-induced epilepsy model. Furthermore, deferasirox administration mitigated seizure susceptibility in a pentylenetetrazol-induced kindling model. Conversely, the augmentation of iron levels through supplementation has emerged as a potential exacerbating factor in the precipitating onset of epilepsy. Intriguingly, our investigation revealed a hitherto unreported discovery: ITPRIP was identified as a pivotal modulator of excitatory synaptic transmission, regulating seizures in response to deferasirox treatment. In summary, our findings indicate that deferasirox exerts its antiepileptic effects through the precise targeting of ITPRIP and amelioration of cerebral iron homeostasis, suggesting that deferasirox is a promising and novel therapeutic avenue for interventions in epilepsy.


Anticonvulsants , Brain , Deferasirox , Epilepsy , Homeostasis , Iron Chelating Agents , Iron , Deferasirox/pharmacology , Iron/metabolism , Animals , Homeostasis/drug effects , Homeostasis/physiology , Epilepsy/drug therapy , Epilepsy/metabolism , Anticonvulsants/pharmacology , Anticonvulsants/therapeutic use , Male , Brain/drug effects , Brain/metabolism , Iron Chelating Agents/pharmacology , Iron Chelating Agents/therapeutic use , Mice , Kindling, Neurologic/drug effects , Pentylenetetrazole/toxicity , Rats, Sprague-Dawley
19.
Bioorg Med Chem Lett ; 107: 129769, 2024 Apr 24.
Article En | MEDLINE | ID: mdl-38670537

Among small-molecule CDK4/6 inhibitors (palbociclib, ribociclib, and abemaciclib) approved for metastatic breast cancers, abemaciclib has a more tolerable adverse effects in clinic. This is attributable to preferential inhibition of CDK4 over CDK6. In our search for a biased CDK4 inhibitor, we discovered a series of pyrimidine-indazole inhibitors. SAR studies led us to TQB3616 as a preferential CDK4 inhibitor. TQB3616 exhibited improvements in both enzymatic and cellular proliferation inhibitory potency when tested side-by-side with the FDA approved palbociclib and abemaciclib. TQB3616 also possessed favorable PK profile in multiple species. These differentiated properties, together with excellent GLP safety profile warranted TQB3616 moving to clinic. TQB3616 entered into clinical development in 2019 and currently in phase III clinical trials (NCT05375461, NCT05365178).

20.
Lipids Health Dis ; 23(1): 81, 2024 Mar 20.
Article En | MEDLINE | ID: mdl-38509584

BACKGROUND: Obesity is associated with extensive white adipose tissue (WAT) expansion and remodeling. Healthy WAT expansion contributes to the maintenance of energy balance in the liver, thereby ameliorating obesity-related hepatic steatosis. Tissue-resident mesenchymal stromal cell populations, including PDGFRß + perivascular cells, are increasingly recognized pivotal as determinants of the manner in which WAT expands. However, the full array of regulatory factors controlling WAT stromal cell functions remains to be fully elucidated. Hypoxia-inducible factors (HIFs) are critical regulators in WAT stromal cell populations such as adipocyte precursor cells (APCs). It is revealed that HIF1α activation within PDGFRß + stromal cells results in the suppression of de novo adipogenesis and the promotion of a pro-fibrogenic cellular program in obese animals. However, the role of HIF2α in PDGFRß + cells remains undetermined in vivo. METHODS: New genetic models were employed in which HIF1α (encoded by the Hif1a gene) and HIF2α (encoded by the Epas1 gene) are selectively inactivated in PDGFRß + cells in an inducible manner using tamoxifen (TAM). With these models, both in vitro and in vivo functional analysis of PDGFRß + cells lacking HIF proteins were performed. Additionally, comprehensive metabolic phenotyping in diet-induced mouse models were performed to investigate the roles of PDGFRß + cell HIF proteins in WAT remodeling, liver energy balance and systemic metabolism. RESULTS: Unlike HIF1α inactivation, the new findings in this study suggest that inducible ablation of HIF2α in PDGFRß + cells does not cause apparent effects on WAT expansion induced by obesogenic diet. The adipogenic ability of PDGFRß + APCs is not significantly altered by genetic HIF2α ablation. Moreover, no difference of key parameters associated with healthy WAT remodeling such as improvements of WAT insulin sensitivity, reduction in metabolic inflammation, as well as changes in liver fat accumulation or systemic glucose metabolism, is detected in PDGFRß + cell Epas1-deficient mice. CONCLUSION: The new findings in this study support that, in contrast to HIF1α, PDGFRß + cell HIF2α appears dispensable for WAT metabolic remodeling and the resulting effects on liver metabolic homeostasis in diet-induced obesity, underscoring the isoform-specific roles of HIFα proteins in the regulation of adipose tissue biology.


Adipose Tissue, White , Basic Helix-Loop-Helix Transcription Factors , Obesity , Animals , Mice , Adipose Tissue/metabolism , Adipose Tissue, White/metabolism , Lipids , Liver/metabolism , Mice, Inbred C57BL , Mice, Obese , Obesity/metabolism , Basic Helix-Loop-Helix Transcription Factors/metabolism
...