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1.
Cell Biosci ; 14(1): 48, 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38627830

ABSTRACT

BACKGROUND: Stress is a recognized risk factor for cognitive decline, which triggers neuroinflammation involving microglial activation. However, the specific mechanism for microglial activation under stress and affects learning and memory remains unclear. METHODS: The chronic stress mouse model was utilized to explore the relationship between microglial activation and spatial memory impairment. The effect of hippocampal hyperglycemia on microglial activation was evaluated through hippocampal glucose-infusion and the incubation of BV2 cells with high glucose. The gain-and loss-of-function experiments were conducted to investigate the role of GLUT1 in microglial proinflammatory activation. An adeno-associated virus (AAV) was employed to specifically knockdown of GLUT1 in hippocampal microglia to assess its impact on stressed-mice. RESULTS: Herein, we found that chronic stress induced remarkable hippocampal microglial proinflammatory activation and neuroinflammation, which were involved in the development of stress-related spatial learning and memory impairment. Mechanistically, elevated hippocampal glucose level post-stress was revealed to be a key regulator of proinflammatory microglial activation via specifically increasing the expression of microglial GLUT1. GLUT1 overexpression promoted microglial proinflammatory phenotype while inhibiting GLUT1 function mitigated this effect under high glucose. Furthermore, specific downregulation of hippocampal microglial GLUT1 in stressed-mice relieved microglial proinflammatory activation, neuroinflammation, and spatial learning and memory injury. Finally, the NF-κB signaling pathway was demonstrated to be involved in the regulatory effect of GLUT1 on microglia. CONCLUSIONS: We demonstrate that elevated glucose and GLUT1 expression induce microglia proinflammatory activation, contributing to stress-associated spatial memory dysfunction. These findings highlight significant interplay between metabolism and inflammation, presenting a possible therapeutic target for stress-related cognitive disorders.

2.
Mol Ther ; 2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38659226

ABSTRACT

Malignant ascites is a common complication resulting from the peritoneal spread of malignancies, and currently lacks effective treatments. We conducted a phase II trial (NCT04771676) to investigate the efficacy and safety of oncolytic adenovirus H101 and virotherapy-induced immune response in 25 patients with malignant ascites. Oncolytic virotherapy achieved an increased median time to repeat paracentesis of 45 days (95% confidence interval 16.5-73.5 days), compared with the preset control value of 13 days. Therapy was well-tolerated, with pyrexia, fatigue, nausea, and abdominal pain as the most common toxicities. Longitudinal single-cell profiling identified marked oncolysis, early virus replication, and enhanced CD8+ T cells-macrophages immune checkpoint crosstalk, especially in responsive patients. H101 also triggered a proliferative burst of CXCR6+ and GZMK+CD8+ T cells with promoted tumor-specific cytotoxicity. Further establishment of oncolytic virus-induced T cell expansion signature (OiTE) implicated the potential benefits for H101-responsive patients from subsequent anti-PD(L)1 therapy. Patients with upregulated immune-signaling pathways in tumor cells and a higher proportion of CLEC10A+ dendritic cells and GZMK+CD8+ T cells at baseline showed a superior response to H101 treatment. Our study demonstrates promising clinical responses and tolerability of oncolytic adenovirus in treating malignant ascites and provides insights into the relevant cellular processes following oncolytic virotherapy.

3.
Alzheimers Dement (Amst) ; 16(1): e12567, 2024.
Article in English | MEDLINE | ID: mdl-38487075

ABSTRACT

INTRODUCTION: White matter hyperintensities (WMHs) are an important imaging marker for cerebral small vessel diseases, but their risk factors and cognitive associations have not been well documented in populations of different ethnicities and/or from different geographical regions. METHODS: We investigated how WMHs were associated with vascular risk factors and cognition in both Whites and Asians, using data from five population-based cohorts of non-demented older individuals from Australia, Singapore, South Korea, and Sweden (N = 1946). WMH volumes (whole brain, periventricular, and deep) were quantified with UBO Detector and harmonized using the ComBat model. We also harmonized various vascular risk factors and scores for global cognition and individual cognitive domains. RESULTS: Factors associated with larger whole brain WMH volumes included diabetes, hypertension, stroke, current smoking, body mass index, higher alcohol intake, and insufficient physical activity. Hypertension and stroke had stronger associations with WMH volumes in Whites than in Asians. No associations between WMH volumes and cognitive performance were found after correction for multiple testing. CONCLUSION: The current study highlights ethnic differences in the contributions of vascular risk factors to WMHs.

4.
Mol Biol Rep ; 51(1): 329, 2024 Feb 23.
Article in English | MEDLINE | ID: mdl-38393658

ABSTRACT

Ventricular arrhythmias are the leading cause of sudden cardiac death in patients after myocardial infarction (MI). Connexin43 (Cx43) is the most important gap junction channel-forming protein in cardiomyocytes. Dysfunction of Cx43 contributes to impaired myocardial conduction and the development of ventricular arrhythmias. Following an MI, Cx43 undergoes structural remodeling, including expression abnormalities, and redistribution. These alterations detrimentally affect intercellular communication and electrical conduction within the myocardium, thereby increasing the susceptibility to post-infarction ventricular arrhythmias. Emerging evidence suggests that post-translational modifications play essential roles in Cx43 regulation after MI. Therefore, Cx43-targeted management has the potential to be a promising protective strategy for the prevention and treatment of post infarction ventricular arrhythmias. In this article, we primarily reviewed the regulatory mechanisms of Cx43 mediated post-translational modifications on post-infarction ventricular arrhythmias. Furthermore, Cx43-targeted therapy have also been discussed, providing insights into an innovative treatment strategy for ventricular arrhythmias after MI.


Subject(s)
Connexin 43 , Myocardial Infarction , Humans , Arrhythmias, Cardiac/metabolism , Connexin 43/genetics , Connexin 43/metabolism , Myocardial Infarction/complications , Myocardial Infarction/metabolism , Myocardium/metabolism , Protein Processing, Post-Translational
5.
Diabetes Metab J ; 2024 Feb 27.
Article in English | MEDLINE | ID: mdl-38408883

ABSTRACT

Background: Diabetes-induced cardiac fibrosis is one of the main mechanisms of diabetic cardiomyopathy. As a common histone methyltransferase, enhancer of zeste homolog 2 (EZH2) has been implicated in fibrosis progression in multiple organs. However, the mechanism of EZH2 in diabetic myocardial fibrosis has not been clarified. Methods: In the current study, rat and mouse diabetic model were established, the left ventricular function of rat and mouse were evaluated by echocardiography and the fibrosis of rat ventricle was evaluated by Masson staining. Primary rat ventricular fibroblasts were cultured and stimulated with high glucose (HG) in vitro. The expression of histone H3 lysine 27 (H3K27) trimethylation, EZH2, and myocardial fibrosis proteins were assayed. Results: In STZ-induced diabetic ventricular tissues and HG-induced primary ventricular fibroblasts in vitro, H3K27 trimethylation was increased and the phosphorylation of EZH2 was reduced. Inhibition of EZH2 with GSK126 suppressed the activation, differentiation, and migration of cardiac fibroblasts as well as the overexpression of the fibrotic proteins induced by HG. Mechanical study demonstrated that HG reduced phosphorylation of EZH2 on Thr311 by inactivating AMP-activated protein kinase (AMPK), which transcriptionally inhibited peroxisome proliferator-activated receptor γ (PPAR-γ) expression to promote the fibroblasts activation and differentiation. Conclusion: Our data revealed an AMPK/EZH2/PPAR-γ signal pathway is involved in HG-induced cardiac fibrosis.

7.
Diabetes Metab Syndr Obes ; 17: 247-257, 2024.
Article in English | MEDLINE | ID: mdl-38269338

ABSTRACT

Purpose: The aim of this study was to investigate the effects and mechanisms of SGLT2 inhibitor empagliflozin on diabetic coronary function. Methods: A rat diabetic model was established by injection of streptozotocin. Rats in the treated group were administered empagliflozin by gavage and rat coronary vascular tensions were measured after eight weeks. Large conductance calcium activated K+ channel currents were recorded using a patch clamp technique, while human coronary artery smooth muscle cells were used to explore the underlying mechanisms. Results: After incubation with empagliflozin (10, 30, 100, 300, 1000 µmol/L), the Δ relaxation % of rat coronary arteries were 2.459 ± 1.304, 3.251 ± 1.119, 6.946 ± 3.407, 28.36 ± 11.47, 86.90 ± 3.868, respectively. Without and with empagliflozin in the bath solution, BK channel opening probabilities at a membrane potential of +60 mV were 0.0458 ± 0.0517 and 0.3413 ± 0.2047, respectively (p < 0.05, n = 4 cells). After incubation with iberiotoxin, the Δ tensions of rat coronary arteries in the control (Ctrl), untreated (DM), low empagliflozin (10 mg/kg/d)-treated (DM+L-EMPA) and high empagliflozin (30mg/kg/d)-treated (DM+H-EMPA) group were 103.20 ± 5.85, 40.37 ± 22.12, 99.47 ± 28.51, 78.06 ± 40.98, respectively (p < 0.01 vs Ctrl, n = 3-7; p < 0.001 vs DM+L-EMPA, n = 5-7). Empagliflozin restored high glucose-induced downregulation of Sirt1, Nrf2, and BK-ß1, while the effect of empagliflozin disappeared in the presence of EX-527, a Sirt1 selective inhibitor. Conclusion: Empagliflozin has a vasodilation effect on the coronary arteries in a concentration-dependent manner and can activate BK channels via the Sirt1-Nrf2 mechanism.

8.
Neuron ; 112(1): 155-173.e8, 2024 Jan 03.
Article in English | MEDLINE | ID: mdl-37944520

ABSTRACT

The hypocretin (Hcrt) (also known as orexin) neuropeptidic wakefulness-promoting system is implicated in the regulation of spatial memory, but its specific role and mechanisms remain poorly understood. In this study, we revealed the innervation of the medial entorhinal cortex (MEC) by Hcrt neurons in mice. Using the genetically encoded G-protein-coupled receptor activation-based Hcrt sensor, we observed a significant increase in Hcrt levels in the MEC during novel object-place exploration. We identified the function of Hcrt at presynaptic glutamatergic terminals, where it recruits fast-spiking parvalbumin-positive neurons and promotes gamma oscillations. Bidirectional manipulations of Hcrt neurons' projections from the lateral hypothalamus (LHHcrt) to MEC revealed the essential role of this pathway in regulating object-place memory encoding, but not recall, through the modulation of gamma oscillations. Our findings highlight the significance of the LHHcrt-MEC circuitry in supporting spatial memory and reveal a unique neural basis for the hypothalamic regulation of spatial memory.


Subject(s)
Hypothalamus , Spatial Memory , Mice , Animals , Orexins/metabolism , Hypothalamus/metabolism , Neurons/physiology , Hypothalamic Area, Lateral/physiology
9.
Geroscience ; 46(1): 969-980, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37306893

ABSTRACT

The therapeutic potential of curcumin for many diseases are intensively investigated. However, real-world observational data documenting health and longevity effects associated with dietary curcumin in turmeric from consuming curry in food is lacking. A prospective cohort study of 4551 adults aged 55 + assessed curry consumption (never or < once/year, ≥ once/year to < once/month, ≥ once/month to < once/week, ≥ once/week to < daily, ≥ once daily), prevalent health conditions, blood biomarker indexes of atherogenicity, insulin resistance, and inflammation at baseline, and mean (SD) 11.6 (3.8) year follow up of all-cause, CVS and cancer mortality. There were linear positive associations of increasing curry consumption with waist circumference, fasting blood glucose, TyG, AIP, CRI-1, CRI-2, central obesity and diabetes prevalence, and inverse association with eGFR. There were non-linear associations with FEV1/height2 and COPD prevalence, GDS score and depression, MMSE score and cognitive impairment, comorbidity count, serum albumin and haemoglobin, being most favourable with moderate consumption. The levels of NLR, PLR and SII indices of systemic and immune inflammation decreased linearly with curry consumption. Total mortality HR adjusted for baseline co-variables, decreased across curry consumption, 0.68 (95%CI 0.56-0.82), 0.54 (95%CI 0.43-0.69), 0.70 (0.52-0.93), and 0.62 (0.41-0.95), being lowest in the middle categories. Among participants with cardio-metabolic and vascular diseases (CMVD), at least occasional curry consumption was associated with decreased mortality risk by 39%, and increased life expectancy by 1.0 years. Among those without CMVD, the associated life expectancy increase was 1.9 years. Moderate curry consumption may confer meaningful longevity benefits.


Subject(s)
Curcumin , Humans , Singapore , Prospective Studies , Aging , Life Expectancy , Inflammation/epidemiology
10.
Small Methods ; 8(3): e2301368, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38009516

ABSTRACT

The presence of toxic organic pollutants in aquatic environments poses significant threats to human health and global ecosystems. Photocatalysis that enables in situ production and activation of H2 O2 presents a promising approach for pollutant removal; however, the processes of H2 O2 production and activation potentially compete for active sites and charge carriers on the photocatalyst surface, leading to limited catalytic performance. Herein, a hierarchical 2D/2D heterojunction nanosphere composed of ultrathin BiOBr and BiOI nanosheets (BiOBr/BiOI) is developed by a one-pot microwave-assisted synthesis to achieve in situ H2 O2 production and activation for efficient photocatalytic wastewater treatment. Various experimental and characterization results reveal that the BiOBr/BiOI heterojunction facilitates efficient electron transfer from BiOBr to BiOI, enabling the one-step two-electron O2 reduction for H2 O2 production. Moreover, the ultrathin BiOI provides abundant active sites for H2 O2 adsorption, promoting in situ H2 O2 activation for •O2 - generation. As a result, the BiOBr/BiOI hybrid exhibits excellent activity for pollutant degradation with an apparent rate constant of 0.141 min-1 , which is 3.8 and 47.3 times that of pristine BiOBr and BiOI, respectively. This work expands the range of the materials suitable for in situ H2 O2 production and activation, paving the way toward sustainable environmental remediation using solar energy.

11.
Liver Int ; 44(3): 723-737, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38111027

ABSTRACT

BACKGROUND: The low response rate of immune checkpoint inhibitors (ICIs) prompts the exploration of novel combination therapies for patients with hepatocellular carcinoma (HCC). Here, we aimed to examine the efficiency and potential mechanism of cryo-thermal ablation (Cryo-A) combined with anti-programmed death protein 1 (αPD1) and/or cytotoxic T-lymphocyte antigen 4 (αCTLA4) inhibitors in a murine hepatoma model. METHOD: Immunocompetent C57BL/6 mice inoculated with unilateral or bilateral H22 hepatic tumour cells were treated with Cryo-A and/or ICIs (αPD1 and/or αCTLA4). Flow cytometry, immunohistochemistry, ELISpot assay, time-of-flight cytometry, tumour rechallenging, and T-cell depletion assay were used to assess the dynamic changes of immune cell subsets following therapy. RESULTS: We found Cryo-A resulted in immunogenic cell death of tumour cells, activation of dendritic cells, and enhancement of antitumor immunity. Cryo-A alone was insufficient to extend survival, combining Cryo-A with αPD1 and αCTLA4 further modulated the tumour microenvironment, inducing a durable antitumor immune response by tumour-reactive CD8+ T cells and significantly prolonged survival. Time-of-flight cytometry (CyTOF) data revealed that combination therapies reshaped the tumour microenvironment by the increase of intratumoral CD8+ T cells expressed higher levels of cytotoxic markers and immune checkpoint molecules, and by downregulation of intratumoral granulocytes. The combination also resulted in the eradication of remote unablated tumours (abscopal effect). CONCLUSIONS: These findings suggested that Cryo-A turned HCC from "cold" tumours to "hot" tumours and the combination of Cryo-A with αPD1 and αCTLA4 may be a promising approach to improve the prognosis of HCC.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Animals , Mice , Carcinoma, Hepatocellular/drug therapy , Liver Neoplasms/drug therapy , Immune Checkpoint Inhibitors/pharmacology , Immune Checkpoint Inhibitors/therapeutic use , CD8-Positive T-Lymphocytes , Mice, Inbred C57BL , Tumor Microenvironment
12.
Brain Behav Immun ; 115: 143-156, 2024 01.
Article in English | MEDLINE | ID: mdl-37848095

ABSTRACT

Growing evidence suggests that neurovascular dysfunction characterized by blood-brain barrier (BBB) breakdown underlies the development of psychiatric disorders, such as major depressive disorder (MDD). Tight junction (TJ) proteins are critical modulators of homeostasis and BBB integrity. TJ protein Claudin-5 is the most dominant BBB component and is downregulated in numerous depression models; however, the underlying mechanisms remain elusive. Here, we demonstrate a molecular basis of BBB breakdown that links stress and depression. We implemented an animal model of depression, chronic unpredictable mild stress (CUMS) in male C57BL/6 mice, and showed that hippocampal BBB breakdown was closely associated with stress vulnerability. Concomitantly, we found that dysregulated Cldn5 level coupled with repression of the histone methylation signature at its promoter contributed to stress-induced BBB dysfunction and depression. Moreover, histone methyltransferase enhancer of zeste homolog 2 (EZH2) knockdown improved Cldn5 expression and alleviated depression-like behaviors by suppressing the tri-methylation of lysine 27 on histone 3 (H3K27me3) in chronically stressed mice. Furthermore, the stress-induced excessive transfer of peripheral cytokine tumor necrosis factor-α (TNF-α) into the hippocampus was prevented by Claudin-5 overexpression and EZH2 knockdown. Interestingly, antidepressant treatment could inhibit H3K27me3 deposition at the Cldn5 promoter, reversing the loss of the encoded protein and BBB damage. Considered together, these findings reveal the importance of the hippocampal EZH2-Claudin-5 axis in regulating neurovascular function and MDD development, providing potential therapeutic targets for this psychiatric illness.


Subject(s)
Blood-Brain Barrier , Depressive Disorder, Major , Humans , Male , Mice , Animals , Blood-Brain Barrier/metabolism , Tumor Necrosis Factor-alpha/metabolism , Histones/metabolism , Claudin-5/genetics , Claudin-5/metabolism , Depression/metabolism , Depressive Disorder, Major/metabolism , Enhancer of Zeste Homolog 2 Protein/metabolism , Mice, Inbred C57BL
13.
J Chem Theory Comput ; 19(24): 9018-9024, 2023 Dec 26.
Article in English | MEDLINE | ID: mdl-38090816

ABSTRACT

Molecular docking is important in drug discovery but is burdensome for classical computers. Here, we introduce Grid Point Matching (GPM) and Feature Atom Matching (FAM) to accelerate pose sampling in molecular docking by encoding the problem into quadratic unconstrained binary optimization (QUBO) models so that it could be solved by quantum computers like the coherent Ising machine (CIM). As a result, GPM shows a sampling power close to that of Glide SP, a method performing an extensive search. Moreover, it is estimated to be 1000 times faster on the CIM than on classical computers. Our methods could boost virtual drug screening of small molecules and peptides in future.

14.
Eur J Pharmacol ; 961: 176167, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-37939994

ABSTRACT

BACKGROUND: Recent evidence revealed that glucose fluctuation might be more likely to cause arrhythmia than persistent hyperglycemia, whereas its mechanisms were elusive. We aimed to investigate the effect of glucose fluctuation on the occurrence of ventricular arrhythmia and its mechanism. METHODS: Streptozotocin (STZ) induced diabetic rats were randomized to five groups: the controlled blood glucose (C-STZ) group, uncontrolled blood glucose (U-STZ) group, fluctuated blood glucose (GF-STZ) group, and GF-STZ rats with 100 mg/kg Tempol (GF-STZ + Tempol) group or with 5 mg/kg KN93 (GF-STZ + KN93) group. Six weeks later, the susceptibility of ventricular arrhythmias and the electrophysiological dysfunctions of ventricular myocytes were evaluated using electrocardiogram and patch-clamp technique, respectively. The levels of reactive oxygen species (ROS) and oxidized CaMKII (ox-CaMKII) were determined by fluorescence assay and Western blot, respectively. Neonatal rat cardiomyocytes and H9C2 cells in vitro were used to explore the underlying mechanisms. RESULTS: The induction rate of ventricular arrhythmias was 10%, 55%, and 90% in C-STZ group, U-STZ group, and GF-STZ group, respectively (P < 0.05). The electrophysiological dysfunctions of ventricular myocytes, including action potential duration at repolarization of 90% (APD90), APD90 short-term variability (APD90-STV), late sodium current (INa-L), early after depolarization (EAD) and delayed after depolarizations (DAD), as well as the levels of ROS and ox-CaMKII, were significantly increased in GF-STZ group. In vivo and ex vivo, inhibition of ROS or ox-CaMKII reversed these effects. Inhibition of INa-L also significantly alleviated the electrophysiological dysfunctions. In vitro, inhibition of ROS increase could significantly decrease the ox-CaMKII activation induced by glucose fluctuations. CONCLUSIONS: Glucose fluctuations aggravated the INa-L induced ventricular arrhythmias though the activation of ROS/CaMKII pathway.


Subject(s)
Diabetes Mellitus, Experimental , Glucose , Animals , Rats , Action Potentials , Arrhythmias, Cardiac/chemically induced , Arrhythmias, Cardiac/metabolism , Blood Glucose/metabolism , Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism , Diabetes Mellitus, Experimental/metabolism , Glucose/metabolism , Myocytes, Cardiac , Reactive Oxygen Species/metabolism , Sodium/metabolism
15.
Psychol Res Behav Manag ; 16: 4677-4683, 2023.
Article in English | MEDLINE | ID: mdl-38024663

ABSTRACT

Purpose: To examine the influence of social behavior on college students' life satisfaction and the mediating effects of perceived social support and core self-evaluation. Methods: 779 college students were investigated with the online social behavior scale, life satisfaction scale, core self-evaluation scale and perceived social support scale. Results: Online social behavior significantly positively predicted the perceived social support and life satisfaction; Perceived social support significantly positively predicted the core self-evaluation and life satisfaction; Core self-evaluation significantly positively predicted life satisfaction; Perceived social support and core self-evaluation have a significant chain mediating effect between online social behavior and life satisfaction. Conclusion: This study confirmed the positive effects of online social behavior on college students, through improving college students' level of perceived social support and core self-evaluation to increase life satisfaction.

16.
Front Endocrinol (Lausanne) ; 14: 1178396, 2023.
Article in English | MEDLINE | ID: mdl-37908752

ABSTRACT

Sleep disorders affect mental and physical health. Infertile women undergoing assisted reproductive technology (ART) treatment are prone to sleep disorders. Sleep condition, its influencing factors, and the association between sleep condition and ART treatment outcomes before treatment have not been explored within a population with a large sample size. Therefore, we investigated the sleep characteristics of 1002 Chinese infertile women before ovulation induction and investigated the influencing factors (negative and positive psychological factors, demographics, and fertility characteristics). We also examined whether sleep conditions before treatment predicted reproductive outcomes. We found that 24.1% of participants reported poor sleep quality. Women with primary infertility reported poorer sleep than women with secondary infertility. Negative psychological factors, including depression, anxiety, and perceived stress were associated with poor sleep, whereas positive affect was linked with good sleep. Adverse sleep characteristics, including poor subjective sleep quality, sleep disturbances, and poor sleep efficiency, decreased the quantity and quality of oocytes retrieved, fertilization rates, and clinical pregnancy rates. This study indicates that before ART treatment, a large number of females with infertility suffer from sleep problems, which are affected by psychological factors and infertility type, and unhealthy sleep characteristics may impair treatment outcomes. Our findings highlight the importance of screening and treatment for sleep disorders before the enrollment of ART treatment in infertile women.


Subject(s)
Infertility, Female , Sleep Wake Disorders , Pregnancy , Humans , Female , Infertility, Female/therapy , Infertility, Female/etiology , Prospective Studies , East Asian People , Reproductive Techniques, Assisted/adverse effects , Sleep , Sleep Wake Disorders/complications , Sleep Wake Disorders/epidemiology , Sleep Wake Disorders/therapy
17.
Diabetol Metab Syndr ; 15(1): 217, 2023 Oct 28.
Article in English | MEDLINE | ID: mdl-37891701

ABSTRACT

BACKGROUND: Glucose fluctuations (GF) are a risk factor for cardiovascular complications associated with type 2 diabetes. However, there is a lack of adequate research on the effect of GF on myocardial fibrosis and the underlying mechanisms in type 2 diabetes. This study aimed to investigate the impact of glucose fluctuations on myocardial fibrosis and explore the potential mechanisms in type 2 diabetes. METHODS: Sprague Dawley (SD) rats were randomly divided into three groups: the control (Con) group, the type 2 diabetic (DM) group and the glucose fluctuations (GF) group. The type 2 diabetic rat model was established using a high-fat diet combined with low-dose streptozotocin injection and the GF model was induced by using staggered glucose and insulin injections daily. After eight weeks, echocardiography was used to assess the cardiac function of the three groups. Hematoxylin-eosin and Masson staining were utilized to evaluate the degree of pathological damage and fibrosis. Meanwhile, a neonatal rat cardiac fibroblast model with GF was established. Western and immunofluorescence were used to find the specific mechanism of myocardial fibrosis caused by GF. RESULTS: Compared with rats in the Con and the DM group, cardiac function in the GF group showed significant impairments. Additionally, the results showed that GF aggravated myocardial fibrosis in vitro and in vivo. Moreover, Ca2+/calmodulin­dependent protein kinase II (CaMKII) was activated by phosphorylation, prompting an increase in phosphorylation of signal transducer and activator of transcription 3 (Stat3) and induced nuclear translocation. Pretreatment with KN-93 (a CaMKII inhibitor) blocked GF-induced Stat3 activation and significantly suppressed myocardial fibrosis. CONCLUSIONS: Glucose fluctuations exacerbate myocardial fibrosis by triggering the CaMKII/Stat3 pathway in type 2 diabetes.

18.
Diabetes Metab Syndr Obes ; 16: 3045-3056, 2023.
Article in English | MEDLINE | ID: mdl-37810573

ABSTRACT

Purpose: Diabetes mellitus is an independent risk factor for atrial fibrillation (AF), which may be related to accumulation of advanced glycation end products (AGEs). However, the mechanisms involved are not completely clear. Abnormality of gap junction proteins, especially connexin 43 (Cx43) and connexin 40 (Cx40) in atrial myocytes, is an important cause of increased susceptibility of AF. The aim of our work is to investigate the mechanism of dysregulated Cx43 and Cx40 in atrial myocytes of diabetic rats. Methods: We established a type 1 diabetic rat model by intraperitoneal injection of streptozotocin. HL-1 cells and primary rat atrial myocytes were treated with AGEs in vitro. Using Western blotting, immunofluorescence staining, immunohistochemistry, and lucifer yellow diffusion measurements, we investigated dysregulation of Cx43 and Cx40 and its mechanism in atrial myocytes of diabetic rats. Results: Accumulation of AGEs was found in diabetic rats. The expression of Cx43 and Cx40 was reduced in the atrium of diabetic rats, accompanied by the decrease of phosphorylated Adenosine 5'-monophosphate-activated protein kinase (p-AMPK). Similar results were found in cultured HL-1 cells and primary rat atrial myocytes, suggesting a role of AGEs on gap junction proteins. An AMPK agonist, 5-Aminoimidazole-4-carboxamide ribonucleoside (AICAR), reversed the down-regulated Cx43 expression induced by AGEs stimulation. More importantly, lucifer yellow diffusion assay showed that AGEs significantly affected gap junctional function, and these changes were reversed by AICAR. Conclusion: Thus, we conclude that AGEs cause dysregulation of Cx43 and Cx40 in diabetic atria via the AMPK pathway, thereby leading to gap junction dysfunction, which may contribute to the increased AF susceptibility in diabetes.

19.
Fa Yi Xue Za Zhi ; 39(4): 373-381, 2023 Aug 25.
Article in English, Chinese | MEDLINE | ID: mdl-37859476

ABSTRACT

OBJECTIVES: To explore the potential biomarkers for the diagnosis of primary brain stem injury (PBSI) by using metabonomics method to observe the changes of metabolites in rats with PBSI caused death. METHODS: PBSI, non-brain stem brain injury and decapitation rat models were established, and metabolic maps of brain stem were obtained by LC-MS metabonomics method and annotated to the HMDB database. Partial least square-discriminant analysis (PLS-DA) and random forest methods were used to screen potential biomarkers associated with PBSI diagnosis. RESULTS: Eighty-six potential metabolic markers associated with PBSI were screened by PLS-DA. They were modeled and predicted by random forest algorithm with an accuracy rate of 83.3%. The 818 metabolic markers annotated to HMDB database were used for random forest modeling and prediction, and the accuracy rate was 88.9%. According to the importance in the identification of cause of death, the most important metabolic markers that were significantly up-regulated in PBSI group were HMDB0038126 (genipinic acid, GA), HMDB0013272 (N-lauroylglycine), HMDB0005199 [(R)-salsolinol] and HMDB0013645 (N,N-dimethylsphingosine). CONCLUSIONS: GA, N-lauroylglycine, (R)-salsolinol and N,N-dimethylsphingosine are expected to be important metabolite indicators in the diagnosis of PBSI caused death, thus providing clues for forensic medicine practice.


Subject(s)
Brain Injuries , Metabolomics , Rats , Animals , Metabolomics/methods , Biomarkers/metabolism , Brain Stem/metabolism
20.
medRxiv ; 2023 Aug 31.
Article in English | MEDLINE | ID: mdl-37693599

ABSTRACT

INTRODUCTION: White matter hyperintensities (WMH) are an important imaging marker for cerebral small vessel diseases, but their risk factors and cognitive associations have not been well-documented in populations of different ethnicities and/or from different geographical regions. METHOD: Magnetic resonance imaging data of five population-based cohorts of non-demented older individuals from Australia, Singapore, South Korea, and Sweden (N = 1,946) were examined for WMH and their associations with vascular risk factors and cognition. RESULT: Factors associated with larger whole brain WMH volumes included diabetes, hypertension, stroke, current smoking, body mass index, higher alcohol intake and insufficient physical activity. Participants with moderate or higher physical activity had less WMH than those who never exercised, but the former two groups did not differ. Hypertension and stroke had stronger associations with WMH volumes in the White, compared to Asian subsample. DISCUSSION: The current study highlighted the ethnic differences in the contributions of vascular risk factors to WMH.

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