PIEZO1 as a new target for hyperglycemic stress-induced neuropathic injury: The potential therapeutic role of bezafibrate.

Hyperglycemic stress can directly lead to neuronal damage. The mechanosensitive ion channel PIEZO1 can be activated in response to hyperglycemia, but its role in hyperglycemic neurotoxicity is unclear. The role of PIEZO1 in hyperglycemic neurotoxicity was explored by constructing a hyperglycemic mouse model and a high-glucose HT22 cell model. The results showed that PIEZO1 was significantly upregulated in response to high glucose stress. In vitro experiments have shown that high glucose stress induces changes in neuronal cell morphology and membrane tension, a key mechanism for PIEZO1 activation. In addition, high glucose stress upregulates serum/glucocorticoid-regulated kinase-1 (SGK1) and activates PIEZO1 through the Ca2+ pool and store-operated calcium entry (SOCE). PIEZO1-mediated Ca2+ influx further enhances SGK1 and SOCE, inducing intracellular Ca2+ peaks in neurons. PIEZO1 mediated intracellular Ca2+ elevation leads to calcium/calmodulin-dependent protein kinase 2α (CaMK2α) overactivation, which promotes oxidative stress and apoptosis signalling through p-CaMK2α/ERK/CREB and ox-CaMK2α/MAPK p38/NFκB p65 pathways, subsequently inducing synaptic damage and cognitive impairment in mice. The intron miR-107 of pantothenic kinase 1 (PANK1) is highly expressed in the brain and has been found to target PIEZO1 and SGK1. The PANK1 receptor is activated by peroxisome proliferator-activated receptor α (PPARα), an activator known to upregulate miR-107 levels in the brain. The clinically used lipid-lowering drug bezafibrate, a known PPARα activator, may upregulate miR-107 through the PPARɑ/PANK1 pathway, thereby inhibiting PIEZO1 and improving hyperglycemia-induced neuronal cell damage. This study provides a new idea for the pathogenesis and drug treatment of hyperglycemic neurotoxicity and diabetes-related cognitive dysfunction.

ω3-PUFA alleviates neuroinflammation by upregulating miR-107 targeting PIEZO1/NFκB p65.

BACKGROUND: MiR-107 is reduced in sepsis and associated with inflammation regulation. Dietary supplementation with polyunsaturated fatty acids (ω3-PUFA) can increase the expression of miR-107; this study investigated whether the ω3-PUFA can effectively inhibit neuroinflammation and improve cognitive function by regulating miR-107 in the brain. METHODS: The LPS-induced mouse model of neuroinflammation and the BV2 cell inflammatory model were used to evaluate the effects of ω3-PUFA on miR-107 expression and inflammation. Intraventricular injection of Agomir and Antagomir was used to modulate miR-107 expression. HE and Nissl staining for analyzing hippocampal neuronal damage, immunofluorescence analysis for glial activation, RT-qPCR, and Western blot were conducted to examine miR-107 expression and inflammation signalling. RESULTS: The result shows that LPS successfully induced the mouse neuroinflammation model and BV2 cell inflammation model. Supplementation of ω3-PUFA effectively reduced the secretion of pro-inflammatory factors TNFα, IL1ß, and IL6 induced by LPS, improved cognitive function impairment, and increased miR-107 expression in the brain. Overexpression of miR-107 in the brain inhibited the nuclear factor κB (NFκB) pro-inflammatory signalling pathway by targeting PIEZO1, thus suppressing microglial and astrocyte activation and reducing the release of inflammatory mediators, which alleviated neuroinflammatory damage and improved cognitive function in mice. miR-107, as an intron of PANK1, PANK1 is subject to PPAR α Adjust. ω3-PUFA can activate PPARα, but ω3-PUFA upregulates brain miR-107, and PPARα/PANK1-related pathways may not be synchronized, and further research is needed to confirm the specific mechanism by which ω3-PUFA upregulates miR-107. CONCLUSION: The miR-107/PIEZO1/NFκB p65 pathway represents a novel mechanism underlying the improvement of neuroinflammation by ω3-PUFA.

Dexamethasone upregulates macrophage PIEZO1 via SGK1, suppressing inflammation and increasing ROS and apoptosis.

The side effects of high-dose dexamethasone in anti-infection include increased ROS production and immune cell apoptosis. Dexamethasone effectively activates serum/glucocorticoid-regulated kinase 1 (SGK1), which upregulates various ion channels by activating store-operated calcium entry (SOCE), leading to Ca2+ oscillations. PIEZO1 plays a crucial role in macrophages' immune activity and function, but whether dexamethasone can regulate PIEZO1 by enhancing SOCE via SGK1 activation remains unclear. The effects of dexamethasone were assessed in a mouse model of sepsis, and primary BMDMs and the RAW264.7 were treated with overexpression plasmids, siRNAs, or specific activators or inhibitors to examine the relationships between SGK1, SOCE, and PIEZO1. The functional and phenotypic changes of mouse and macrophage models were detected. The results indicate that high-dose dexamethasone upregulated SGK1 by activating the macrophage glucocorticoid receptor, which enhanced SOCE and subsequently activated PIEZO1. Activation of PIEZO1 resulted in Ca2+ influx and cytoskeletal remodelling. The increase in intracellular Ca2+ mediated by PIEZO1 further increased the activation of SGK1 and ORAI1/STIM1, leading to intracellular Ca2+ peaks. In the context of inflammation, activation of PIEZO1 suppressed the activation of TLR4/NFκB p65 in macrophages. In RAW264.7 cells, PIEZO1 continuous activation inhibited the change in mitochondrial membrane potential, accelerated ROS accumulation, and induced autophagic damage and cell apoptosis in the late stage. CaMK2α was identified as a downstream mediator of TLR4 and PIEZO1, facilitating high-dose dexamethasone-induced macrophage immunosuppression and apoptosis. PIEZO1 is a new glucocorticoid target to regulate macrophage function and activity. This study provides a theoretical basis for the rational use of dexamethasone.

Minocycline alleviates LPS-induced cognitive dysfunction in mice by inhibiting the NLRP3/caspase-1 pathway.

BACKGROUND: Growing experimental evidence indicates that cognitive impairment is linked to neuroinflammation. Minocycline (MINO), an antibiotic known for its anti-inflammatory, has shown promise in alleviating cognitive impairment. Nonetheless, the exact mechanism through which MINO improves cognitive impairment is not yet understood. METHODS: A neuroinflammatory model was establish by utilizing lipopolysaccharide. The assessment of mice's cognitive and learning abilities was conducted through the MWM and Y-maze tests. The evaluation of hippocampal neuronal injury and microglial activation were achieved by performing HE staining and IHC, respectively. To evaluate BV2 cell viability and apoptosis, the CCK-8 and Hoechst 33342/PI staining assays were employed. In order to assess the protein and RNA expression levels of NLRP3, caspase-1, IL-1ß, IL-18, Iba-1, and Bcl2/Bax, WB and RT-qPCR were utilized. Additionally, the inhibitory effect of MINO on apoptosis by targeting the NLRP3/caspase-1 pathway was investigated using Nigericin. RESULTS: MINO was effective in reducing the time it took for mice to escape from the test, increasing the number of platforms they crossed, and mitigating damage to the hippocampus while also suppressing microglial activation and the expression of Iba-1 in a neuroinflammatory model caused by LPS. Furthermore, MINO improved the viability of BV2 cell and reduced apoptosis. It also had the effect of reducing the expression levels of NLRP3/Caspase-1, IL-1ß, IL-18, and BAX, while upregulating the expression of Bcl2. Additionally, MINO was found to downregulate the NLRP3 expression, which is specifically activated by nigericin. CONCLUSION: The protective effect of MINO relies on the crucial involvement of the NLRP3/caspase-1 pathway.

Association between the Triglyceride-Glucose Index and Non-Alcoholic Fatty Liver Disease in patients with Atrial Fibrillation.

BACKGROUND: The triglyceride and glucose index (TyG), as a surrogate of insulin resistance (IR), is closely associated with non-alcoholic fatty liver disease (NAFLD). However, the association between the TyG index and NAFLD in atrial fibrillation (AF) is unknown. Therefore, the purpose of this study is to explore the association between the TyG index and NAFLD in AF. METHODS: This retrospective study was performed at Nanchang University's Second Affiliated Hospital. The AF patients who were hospitalized from January 2021 to December 2022 were enrolled. The association between the TyG index and NAFLD in AF patients was assessed by logistic regression and restricted cubic spline analysis. The ability of TyG index for identifying NAFLD was estimated by the area under the receiver operating characteristic (ROC). RESULTS: In this study, 632 people participated in the final analysis, with 176 (27.84%) having NAFLD. In the full adjustment model, there is an association between the TyG index and NAFLD [per 1 unit increment; odds ratios (ORs): 3.28; 95% confidence interval (CI) 2.14, 5.03]. Compared to the lowest tertile (TyG index < 8.29), the ORs for the highest tertile (TyG index ≥ 8.82) were 4.15 (95%CI: 2.28, 7.53). Dose-response analysis showed that the TyG index and NAFLD have a nearly linear relationship (P non-linear = 0.71). The area under the curve (AUC) of the TyG index is 0.735. CONCLUSIONS: Our findings showed a significant association between the TyG index and NAFLD. The TyG index may be a good marker for predicting NAFLD in AF patients.

Piezo1 Channels as Force Sensors in Mechanical Force-Related Chronic Inflammation.

Mechanical damage is one of the predisposing factors of inflammation, and it runs through the entire inflammatory pathological process. Repeated or persistent damaging mechanical irritation leads to chronic inflammatory diseases. The mechanism of how mechanical forces induce inflammation is not fully understood. Piezo1 is a newly discovered mechanically sensitive ion channel. The Piezo1 channel opens in response to mechanical stimuli, transducing mechanical signals into an inflammatory cascade in the cell leading to tissue inflammation. A large amount of evidence shows that Piezo1 plays a vital role in the occurrence and progression of chronic inflammatory diseases. This mini-review briefly presents new evidence that Piezo1 responds to different mechanical stresses to trigger inflammation in various tissues. The discovery of Piezo1 provides new insights for the treatment of chronic inflammatory diseases related to mechanical stress. Inhibiting the transduction of damaging mechanical signals into inflammatory signals can inhibit inflammation and improve the outcome of inflammation at an early stage. The pharmacology of Piezo1 has shown bright prospects. The development of tissue-specific Piezo1 drugs for clinical use may be a new target for treating chronic inflammation.

LncRNA-mRNA Expression Profiles and Functional Networks Associated with Cognitive Impairment in Folate-deficient Mice.

BACKGROUND: Cognitive impairment is a common neurocognitive disorder that affects the health of millions of people worldwide, related to folate deficiency. OBJECTIVE: The present study aimed to investigate the lncRNA-mRNA functional networks associated with cognitive impairment in folate-deficient mice and elucidate their possible molecular mechanisms. METHODS: We downloaded the gene expression profile (GSE148126) of lncRNAs and mRNAs from NCBI Gene Expression Omnibus (GEO) database. Four groups of mouse hippocampi were analyzed, including 4 months (4mo) and 18 months (18mo) of folic acid (FA) deficiency/supplementation. The differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) were identified using gplots and heatmap packages. The functions of the DEmRNAs were evaluated using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The hub genes were identified by CytoHubba plugins of Cytoscape, and protein-protein interaction (PPI) network of deregulated mRNAs was performed using the STRING database. Finally, lncRNA-mRNA co-expression and competitive endogenous RNA (ceRNA) network analyses were constructed. RESULTS: In total, we screened 67 lncRNAs with 211 mRNAs, and 89 lncRNAs with 229 mRNAs were differentially expressed in 4mo_FA and 18mo_FA deficient mice, respectively. GO analyses indicated that DEmRNAs were highly related to terms involved in binding and biological regulation. KEGG pathway analyses demonstrated that these genes were significantly enriched for renin secretion, pancreatic secretion, and AMPK signaling pathways in the 18mo_FA deficiency group. Subsequently, the top 5 hub genes were screened from the PPI network, which may be key genes with the progression of folate deficiency. Upon the lncRNA-mRNA co-expression network analysis, we identified the top 10 lncRNAs having the maximum number of connections with related mRNAs. Finally, a ceRNA network was constructed for DE lncRNAs and DEmRNAs, and several pivotal miRNAs were predicted. CONCLUSIONS: This study identified the lncRNA-mRNA expression profiles and functional networks associated with cognitive impairment in folate-deficient mice by bioinformatics analysis, which provided support for the possible mechanisms and therapy for this disease.

Non-coding RNAs: The key regulators in NLRP3 inflammasome-mediated inflammatory diseases.

Inflammasomes are multiprotein complexes responding to various microbes and endogenous danger signals, contributing to initiating the innate protective response of inflammatory diseases. NLRP3 inflammasome is a crucial regulator of pro-inflammatory cytokines (IL-1ß and IL-18) production through activating caspase-1. Non-coding RNAs (ncRNAs) are a class of RNA transcripts lacking the ability to encode peptides or proteins. Its dysregulation leads to the development and progression of inflammation in diseases. Recently, accumulating evidence has indicated that NLRP3 inflammasome activation could be modulated by ncRNAs (lncRNAs, miRNAs, and circRNAs) in a variety of inflammatory diseases. This review focuses on the substantial role and function of ncRNAs in the NLRP3 inflammasome activation, providing novel insight for the future therapeutic approach of inflammatory diseases.

LncRNA 4344 promotes NLRP3-related neuroinflammation and cognitive impairment by targeting miR-138-5p.

OBJECTIVE: Cognitive impairment is a common neurological disease of which NLRP3-related neuroinflammation has been demonstrated to be an essential mediator. Previous studies have indicated that long non-coding RNAs (lncRNAs) are critical for the development of neurological disorders. However, the roles and functions of lncRNA 4344 in neuroinflammation during cognitive impairment are unknown and need to be further elucidated. METHODS: Lipopolysaccharide (LPS)-induced rat cognitive impairment and rat microglia (RM) cell inflammation models were established in vitro and in vivo. The Morris water maze test was used to evaluate the cognitive behavior of the rats. Gene expression was assessed using real-time quantitative polymerase chain reaction, and protein levels using enzyme-linked immunosorbent assay, or western blot analysis. The targeting relationship between lncRNA 4344, miR-138-5p, and NLRP3 was identified using bioinformatics analysis and a dual-luciferase reporter gene assay. Hematoxylin-Eosin and Nissl stainings, terminal deoxynucleotidyl transferase dUTP nick end labeling, or immunofluorescence staining assays were performed to detect pathological changes, neuronal apoptosis, or positive cells in hippocampal tissues, respectively. RESULTS: The expression levels of lncRNA 4344 and NLRP3 were upregulated in the hippocampal tissues of LPS-treated rats and RM cells, and showed a strong positive correlation between each other. LncRNA 4344 overexpression further enhanced the expression of NLRP3 and its downstream genes (caspase-1, IL-1ß, and IL-18), as well as neuronal apoptosis in LPS-stimulated RM cells, whereas lncRNA 4344 silencing attenuated the inflammatory injuries. Moreover, miR-138-5p was the direct target of lncRNA 4344 and was downregulated in the RM cell inflammation model. We also found that miR-138-5p directly reduced the expression of NLRP3 and its downstream genes. Subsequently, the results of the animal experiments showed that the lncRNA 4344/miR-138-5p/NLRP3 axis plays an essential role in regulating the cognitive behavior, pathological changes and apoptosis of hippocampal neurons, expression of inflammation-related factors (NLRP3, caspase-1, IL-1ß, and IL-18), and microglial activation in LPS-induced cognitive impairment rats. CONCLUSION: Our results demonstrated for the first time that lncRNA 4344 regulates NLRP3-related neuroinflammation and cognitive impairment by targeting miR-138-5p, providing a possible target for the treatment of diseases characterized by a cognitive deficit.

MicroRNA-138-5p Regulates Hippocampal Neuroinflammation and Cognitive Impairment by NLRP3/Caspase-1 Signaling Pathway in Rats.

PURPOSE: Neuroinflammation is an essential causative factor in the pathogenesis and progression of cognitive impairment. The present study aims to evaluate the critical role of microRNA-138-5p (miR-138-5p) in hippocampal neuroinflammation and cognitive impairment through the NLRP3/caspase-1 signaling pathway in rats. MATERIAL AND METHODS: We established the cognitive impairment rat model and RM (Rat microglia) microglial cellular inflammation model by intracerebroventricular (icv) injection or stimulation of lipopolysaccharide (LPS). Morris water maze (MWM) and Y-maze tests were performed to assess the cognitive behaviors. Quantitative real-time polymerase chain reaction (qRT-PCR), Enzyme-linked immune-sorbent assay (ELISA) and Western blot analysis were utilized to evaluate mRNA or protein expression. Bioinformatic analysis and dual-luciferase reporter gene assay were performed to verify the targeting relationship between NLRP3 and miR-138-5p. Besides, Hematoxylin and eosin (H&E) staining and immunohistochemistry were applied to observe the neuronal morphology and detect the positive cells of the hippocampus, respectively. RESULTS: Compared to the control groups, LPS-treated rats exhibited significantly impaired learning and memory in MWM and Y-maze tests. The expression of NLRP3, caspase-1 and pro-inflammation cytokines (IL-1ß and IL-18) were upregulated, while miR-138-5p was downregulated both in rat hippocampus and RM cells treated with LPS. MiR-138-5p is downregulated in microarray data of cognitive impairment animals and could directly target the 3'-UTR of NLRP3. Furthermore, upregulation of miR-138-5p improved impaired cognitive functions, while inhibited hippocampal neuroinflammation demonstrated by decreased expression of NLRP3/caspase-1 axis, pro-inflammation cytokines and microglial activation. This study demonstrates for the first time that miR-138-5p suppresses the hippocampal NLRP3/caspase-1 signaling pathway activation in cognition impaired rats. CONCLUSION: The low expression of miR-138-5p after LPS administration may contribute to the activation of the NLRP3/caspase-1 pathway, leading to hippocampal neuroinflammation and cognitive impairment in rat models. These findings indicate a promising therapeutic avenue for cognitive disorders.

Sleep Deprivation Induces Cognitive Impairment by Increasing Blood-Brain Barrier Permeability via CD44.

Sleep deprivation occurs frequently in older adults, which can result in delirium and cognitive impairment. CD44 is a key molecular in blood-brain barrier (BBB) regulation. However, whether CD44 participates in the role of sleep deprivation in cognitive impairment remains unclear. In this study, the effect of sleep deprivation on cognitive ability, tissue inflammation, BBB permeability, and astrocyte activity were evaluated in vivo. The differentially expressed genes (DEGs) were identified by RNA sequencing. A CD44 overexpression in the BBB model was performed in vitro to assess the effect and mechanisms of CD44. Sleep deprivation impaired the learning and memory ability and increased the levels of inflammatory cytokines, along with increased BBB permeability and activated astrocytes in hippocampus tissue. RNA sequencing of the hippocampus tissue revealed that 329 genes were upregulated in sleep deprivation-induced mice compared to control mice, and 147 genes were downregulated. GO and pathways showed that DEGs were mainly involved in BBB permeability and astrocyte activation, including nervous system development, neuron development, and brain development, and neuroactive ligand-receptor interaction. Moreover, the PCR analysis revealed that CD44 was dramatically increased in mice with sleep deprivation induction. The overexpression of CD44 in astrocytes promoted BBB permeability in vitro and induced the expression of the downstream gene NANOG. Our results indicate that sleep deprivation upregulated CD44 expression in hippocampus tissue, and increased BBB permeability, resulting in cognitive impairment.

Microsatellite analyses of loci at 7q31.3-q36 reveal a minimum of two common regions of deletion in nasopharyngeal carcinoma.

OBJECTIVE: Our goal was to better define the extent and specificity of deletion in the 7q32-qter chromosomal region in nasopharyngeal carcinoma (NPC). DESIGN AND SETTING: Polymerase chain reaction-based deletion analysis was performed on DNA samples from 24 paired NPCs and corresponding germlines using 13 microsatellite markers mapped to chromosome subbands 7q31.3-q36. RESULTS: Loss of heterozygosity of at least 1 marker in this interval was found in 18 (75%) of 24 tumor specimens. Particularly frequent allelic losses were identified at 5 loci: D7S495 (46%), D7S509 (42%), D7S500 (45%), D7S631 (30%), and D7S514 (35%). Two shortest regions of overlap could be identified in this interval, although the most common shortest region of overlap appeared to lie around D7S500 between but not including D7S631 and D7S495, on chromosome subband 7q32. CONCLUSION: These results suggest that at least 2 putative tumor suppressor genes important in the pathogenesis of NPC are present in the examined interval, an interval that has also been found to harbor deletions in breast and prostate carcinomas.