PLC-CN-NFAT1 signaling-mediated Aß and IL-1ß crosstalk synergistically promotes hippocampal neuronal damage.

Alzheimer's disease (AD) is a progressive neurodegenerative disease. Neuronal calcium overload plays an important role in Aß deposition and neuroinflammation, which are strongly associated with AD. However, the specific mechanisms by which calcium overload contributes to neuroinflammation and AD and the relationship between them have not been elucidated. Phospholipase C (PLC) is involved in regulation of calcium homeostasis, and CN-NFAT1 signaling is dependent on intracellular Ca2+ ([Ca2+]i) to regulate transcription of genes. Therefore, we hypothesized that the PLC-CN-NFAT1 signaling might mediate the interaction between Aß and inflammation to promote neuronal injury in AD. In this experiment, the results showed that the levels of Aß, IL-1ß and [Ca2+]i in the hippocampal primary neurons of APP/PS1 mice (APP neurons) were significantly increased. IL-1ß exposure also significantly increased Aß and [Ca2+]i in HT22 cells, suggesting a close association between Aß and IL-1ß in the development of AD. Furthermore, PLC activation induced significant calcium homeostasis imbalance, cell apoptosis, Aß and ROS production, and significantly increased expressions of CN and NFAT1, while PLC inhibitor significantly reversed these changes in APP neurons and IL-1ß-induced HT22 cells. Further results indicated that PLC activation significantly increased the expressions of NOX2, APP, BACE1, and NCSTN, which were inhibited by PLC inhibitor in APP neurons and IL-1ß-induced HT22 cells. All indications point to a synergistic interaction between Aß and IL-1ß by activating the PLC-CN-NFAT1 signal, ultimately causing a vicious cycle, resulting in neuronal damage in AD. The study may provide a new idea and target for treatment of AD.

Ginsenoside Rg1 alleviates chronic inflammation-induced neuronal ferroptosis and cognitive impairments via regulation of AIM2 - Nrf2 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginseng is a valuable herb in traditional Chinese medicine. Modern research has shown that it has various benefits, including tonifying vital energy, nourishing and strengthening the body, calming the mind, improving cognitive function, regulating fluids, and returning blood pressure, etc. Rg1 is a primary active component of ginseng. It protects hippocampal neurons, improves synaptic plasticity, enhances cognitive function, and boosts immunity. Furthermore, it exhibits anti-aging and anti-fatigue properties and holds great potential for preventing and managing neurodegenerative diseases (NDDs). AIM OF THE STUDY: The objective of this study was to examine the role of Rg1 in treating chronic inflammatory NDDs and its molecular mechanisms. MATERIALS AND METHODS: In vivo, we investigated the protective effects of Rg1 against chronic neuroinflammation and cognitive deficits in mice induced by 200 µg/kg lipopolysaccharide (LPS) for 21 days using behavioral tests, pathological sections, Western blot, qPCR and immunostaining. In vitro experiments involved the stimulation of HT22 cells with 10 µg/ml of LPS, verification of the therapeutic effect of Rg1, and elucidation of its potential mechanism of action using H2DCFDA staining, BODIPY™ 581/591 C11, JC-1 staining, Western blot, and immunostaining. RESULTS: Firstly, it was found that Rg1 significantly improved chronic LPS-induced behavioral and cognitive dysfunction in mice. Further studies showed that Rg1 significantly attenuated LPS-induced neuronal damage by reducing levels of IL-6, IL-1ß and ROS, and inhibiting AIM2 inflammasome. Furthermore, chronic LPS exposure induced the onset of neuronal ferroptosis by increasing the lipid peroxidation product MDA and regulating the ferroptosis-associated proteins Gpx4, xCT, FSP1, DMT1 and TfR, which were reversed by Rg1 treatment. Additionally, Rg1 was found to activate Nrf2 and its downstream antioxidant enzymes, such as HO1 and NQO1, both in vivo and in vitro. In vitro studies also showed that the Nrf2 inhibitor ML385 could inhibit the anti-inflammatory, antioxidant, and anti-ferroptosis effects of Rg1. CONCLUSIONS: This study demonstrated that Rg1 administration ameliorated chronic LPS-induced cognitive deficits and neuronal ferroptosis in mice by inhibiting neuroinflammation and oxidative stress. The underlying mechanisms may be related to the inhibition of AIM2 inflammasome and activation of Nrf2 signaling. These findings provide valuable insights into the treatment of chronic neuroinflammation and associated NDDs.

Ginsenoside Rg1 attenuates lipopolysaccharide-induced chronic liver damage by activating Nrf2 signaling and inhibiting inflammasomes in hepatic cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginseng (Panax ginseng C. A. Meyer) is a precious traditional Chinese medicine with multiple pharmacological effects. Ginsenoside Rg1 is a main active ingredient extracted from ginseng, which is known for its age-delaying and antioxidant effects. Increasing evidence indicates that Rg1 exhibits anti-inflammatory properties in numerous diseases and may ameliorate oxidative damage and inflammation in many chronic liver diseases. AIM OF THE STUDY: Chronic inflammatory injury in liver cells is an important pathological basis of many liver diseases. However, its mechanism remains unclear and therapeutic strategies to prevent its development need to be further explored. Thus, our study is to delve the protective effect and mechanism of Rg1 against chronic hepatic inflammatory injuries induced by lipopolysaccharide (LPS). MATERIALS AND METHODS: The chronic liver damage model in mice was build up by injecting intraperitoneally with LPS (200 µg/kg) for 21 days. Serum liver function indicators and levels of IL-1ß, IL-6 and TNF-α were examined by using corresponding Kits. Hematoxylin and Eosin (H&E), Periodic acid-Schiff (PAS), and Masson stains were utilized to visualize hepatic histopathological damage, glycogen deposition, and liver fibrosis. The nuclear import of p-Nrf2 and the generation of Col4 in the liver were detected by IF, while IHC was employed to detect the expressions of NLRP3 and AIM2 in the hepatic. The Western blot and q-PCR were used to survey the expressions of proteins and mRNAs of fibrosis and apoptosis, and the expressions of Keap1, p-Nrf2 and NLRP3, NLRP1, AIM2 inflammasome-related proteins in mouse liver. The cell viability of human hepatocellular carcinoma cells (HepG2) was detected by Cell Counting Kit-8 to select the action concentration of LPS, and intracellular ROS generation was detected using a kit. The expressions of Nuclear Nrf2, HO-1, NQO1 and NLRP3, NLRP1, and AIM2 inflammasome-related proteins in HepG2 cells were detected by Western blot. Finally, the feasibility of the molecular interlinking between Rg1 and Nrf2 was demonstrated by molecular docking. RESULTS: Rg1 treatment for 21 days decreased the levels of ALT, AST, and inflammatory factors of serum IL-1ß, IL-6 and TNF-α in mice induced by LPS. Pathological results indicated that Rg1 treatment obviously alleviated hepatocellular injury and apoptosis, inflammatory cell infiltration and liver fibrosis in LPS stimulated mice. Rg1 promoted Keap1 degradation and enhanced the expressions of p-Nrf2, HO-1 and decreased the levels of NLRP1, NLRP3, AIM2, cleaved caspase-1, IL-1ß and IL-6 in livers caused by LPS. Furthermore, Rg1 effectively suppressed the rise of ROS in HepG2 cells induced by LPS, whereas inhibition of Nrf2 reversed the role of Rg1 in reducing the production of ROS and NLRP3, NLRP1, and AIM2 expressions in LPS-stimulated HepG2 cells. Finally, the molecular docking illustrated that Rg1 exhibits a strong affinity towards Nrf2. CONCLUSION: The findings indicate that Rg1 significantly ameliorates chronic liver damage and fibrosis induced by LPS. The mechanism may be mediated through promoting the dissociation of Nrf2 from Keap1 and then activating Nrf2 signaling and further inhibiting NLRP3, NLRP1, and AIM2 inflammasomes in liver cells.

Trpc6 knockout protects against renal fibrosis by restraining the CN­NFAT2 signaling pathway in T2DM mice.

Diabetic kidney disease (DKD), one of the common complications of type­2 diabetes mellitus (T2DM), has become the principal cause of end­stage kidney disease. Transient receptor potential channel 6 (TRPC6), one of non­selective cation channels with significant calcium­permeability, is associated with renal fibrosis. However, the mechanism of TRPC6 in T2DM­induced renal fibrosis is still not entirely understood. The present study explored the potential mechanism of Trpc6 knockout in T2DM­induced renal fibrosis in Trpc6­/­ mice. The results showed that Trpc6 knockout inhibited the loss of body weight and the increase of fasting blood glucose (FBG) and significantly improved renal dysfunction and glomerular fibrosis in T2DM mice. The present study also indicated that Trpc6 knockout significantly lowered the expression of phosphorylated (p­)SMAD2/3, TGF­ß, calcineurin (CN), nuclear factor of activated T­cell (NFAT)2 and Nod­like receptor (NLR) 3 inflammasome­associated proteins. Calcium imaging results revealed that Trpc6 knockdown could decrease the levels of [Ca2+]i and inhibited calcium homeostasis imbalance. Moreover, it was found that knockout of Trpc6 had no significant influence on lipid disposition and reactive oxygen species generation in the kidney cortex. The present study suggested that knockout of Trpc6 may alleviate glomerular fibrosis and delay DKD progression by reducing [Ca2+]i overload and inhibiting the CN­NFAT2 pathway in T2DM mice.

Li, P HY-021068 alleviates cerebral ischemia-reperfusion injury by inhibiting NLRP1 inflammasome and restoring autophagy function in mice.

Cerebral ischemia-reperfusion injury (CIRI) is a severe pathological condition that involves oxidative stress, inflammatory response, and neuronal damage. HY-021068 belongs to a new drug of chemical class 1, which is a potential thromboxane synthase inhibitor. Our preliminary experiment found that HY-021068 has significant anti-neuroinflammatory and neuroprotective effects. However, the protective effect and mechanism of HY-021068 in CIRI remain unclear. To investigate the protective effect and mechanism of HY-021068 in CIRI mice. In mice, CIRI was induced by bilateral common carotid artery occlusion and reperfusion. Mice were treated with HY-021068 or LV-NLRP1-shRNA (lentivirus-mediated shRNA transfection to knock down NLRP1 expression). The locomotor activity, neuronal damage, pathological changes, postsynaptic density protein-95 (PSD-95) expression, NLRP1 inflammasome activation, autophagy markers, and apoptotic proteins were assessed in CIRI mice. In this study, treatment with HY-021065 and LV-NLRP1-shRNA significantly improved motor dysfunction and neuronal damage after CIRI in mice. HY-021065 and NLRP1 knockdown significantly ameliorated the pathological damage and increased PSD-95 expression in the cortex and hippocampus CA1 and CA3 regions. The further studies showed that compared with the CIRI model group, HY-021065 and NLRP1 knockdown treatment inhibited the expressions of NLRP1, ASC, caspase-1, and IL-1ß, restored the expressions of p-AMPK/AMPK, Beclin1, LC3II/LC3I, p-mTOR/m-TOR and P62, and regulated the expressions of BCL-2, Caspase3, and BAX in brain tissues of CIRI mice in CIRI mice. These results suggest that HY-021068 exerts a protective role in CIRI mice by inhibiting NLRP1 inflammasome activation and regulating autophagy function and neuronal apoptosis. HY-021068 is expected to become a new therapeutic drug for CIRI.

Comprehensive analysis of mRNAs in the cerebral cortex in APP/PS1 double-transgenic mice with Alzheimer's disease based on high-throughput sequencing of N4-acetylcytidine.

N4-acetylcytidine (ac4C), a significant modified nucleoside, participates in the development of many diseases. Messenger RNAs (mRNAs) contain most of the information of the genome and are the molecules that transmit information from genes to proteins. Alzheimer's disease (AD) is a progressive neurodegenerative disease in which fibrillar amyloid plaques are present. However, it remains unknown how mRNA ac4C modification affects the development of AD. In the current study, ac4C-modified mRNAs were comprehensively analyzed in AD mice by ac4C-RIP-seq and RNA-seq. Next, a protein-protein interaction (PPI) network was constructed to examine the relationships between the genes with differential ac4C modification levels and their RNA expression levels. The differentially expressed genes (DEGs) acquired above were subjected to Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis to further analyze the molecular mechanisms in AD. In total, 3312 significant ac4C peaks were found on 2512 mRNAs, 1241 of which were hyperacetylated and 1271 of which were hypoacetylated. In addition, 956 mRNAs with differential expression were found, including 520 upregulated mRNAs and 436 downregulated mRNAs. Overall, 134 mRNAs with simultaneous changes at the ac4C levels as well as RNA expression levels were identified via joint analysis. Then, through PPI network construction and functional enrichment analysis, 37 key mRNAs were screened, which were predominantly enriched in GABAergic synapses and the PI3K/AKT signaling pathway. The significant difference in the abundance of mRNA ac4C modification indicates that this modification is associated with AD progression, which may provide insight for more investigations of the potential mechanisms.

Ginsenoside Rg1 treatment protects against cognitive dysfunction via inhibiting PLC-CN-NFAT1 signaling in T2DM mice.

Background: As a complication of Type II Diabetes Mellitus (T2DM), the etiology, pathogenesis, and treatment of cognitive dysfunction are still undefined. Recent studies demonstrated that Ginsenoside Rg1 (Rg1) has promising neuroprotective properties, but the effect and mechanism in diabetes-associated cognitive dysfunction (DACD) deserve further investigation. Methods: After establishing the T2DM model with a high-fat diet and STZ intraperitoneal injection, Rg1 was given for 8 weeks. The behavior alterations and neuronal lesions were judged using the open field test (OFT) and Morris water maze (MWM), as well as HE and Nissl staining. The protein or mRNA changes of NOX2, p-PLC, TRPC6, CN, NFAT1, APP, BACE1, NCSTN, and Aß1-42 were investigated by immunoblot, immunofluorescence or qPCR. Commercial kits were used to evaluate the levels of IP3, DAG, and calcium ion (Ca2+) in brain tissues. Results: Rg1 therapy improved memory impairment and neuronal injury, decreased ROS, IP3, and DAG levels to revert Ca2+ overload, downregulated the expressions of p-PLC, TRPC6, CN, and NFAT1 nuclear translocation, and alleviated Aß deposition in T2DM mice. In addition, Rg1 therapy elevated the expression of PSD95 and SYN in T2DM mice, which in turn improved synaptic dysfunction. Conclusions: Rg1 therapy may improve neuronal injury and DACD via mediating PLC-CN-NFAT1 signal pathway to reduce Aß generation in T2DM mice.

Interruption of TRPC6-NFATC1 signaling inhibits NADPH oxidase 4 and VSMCs phenotypic switch in intracranial aneurysm.

Intracranial aneurysm (IA) is a frequent cerebrovascular disorder with unclear pathogenesis. The vascular smooth muscle cells (VSMCs) phenotypic switch is essential for IA formation. It has been reported that Ca2+ overload and excessive reactive oxygen species (ROS) are involved in VSMCs phenotypic switch. The transient receptor potential canonical 6 (TRPC6) and NADPH oxidase 4 (NOX4) are the main pathway to participate in Ca2+ overload and ROS production in VSMCs. Ca2+ overload can activate calcineurin (CN), leading to nuclear factor of activated T cell (NFAT) dephosphorylation to regulate the target gene's transcription. We hypothesized that activation of TRPC6-NFATC1 signaling may upregulate NOX4 and involve in VSMCs phenotypic switch contributing to the progression of IA. Our results showed that the expressions of NOX4, p22phox, p47phox, TRPC6, CN and NFATC1 were significantly increased, and VSMCs underwent a significant phenotypic switch in IA tissue and cellular specimens. The VIVIT (NFATC1 inhibitor) and BI-749327 (TRPC6 inhibitor) treatment reduced the expressions of NOX4, p22phox and p47phox and the production of ROS, and significantly improved VSMCs phenotypic switch in IA rats and cells. Consistent results were obtained from IA Trpc6 knockout (Trpc6-/-) mice. Furthermore, the results also revealed that NFATC1 could regulate NOX4 transcription by binding to its promoter. Our findings reveal that interrupting the TRPC6-NFATC1 signaling inhibits NOX4 and improves VSMCs phenotypic switch in IA, and regulating Ca2+ homeostasis may be an important therapeutic strategy for IA.

Ginsenoside Rg1 treatment alleviates renal fibrosis by inhibiting the NOX4-MAPK pathway in T2DM mice.

Diabetic kidney disease (DKD) is a severe complication of type 2 diabetes mellitus (T2DM). However, the pathogenesis of DKD remains unclear, and effective treatment strategies are still lacking. Ginsenoside Rg1 (Rg1) has been reported to improve DKD, but the mechanism is unclear. NADPH oxidase 4 (NOX4) is an essential reactive oxygen species (ROS) source in the kidney. The mitogen-activated protein kinase (MAPK) signaling may exacerbate renal fibrosis. Therefore, we hypothesized that Rg1 might alleviate renal injury and fibrosis by inhibiting NOX4 and MAPK signaling in T2DM-induced DKD. We found that Rg1 significantly improves lipid deposition, fibrosis, and ROS production and reduces NOX4, p22phox, p47phox, p-ERK, p-JNK, and p-P38 MAPK expressions in the T2DM mice kidneys. We also found that the high-fat diet treatment in mice and the palmitate (PA) and PA + HG (high glucose) exposure in human mesangial cells could significantly induce lipid deposition, ROS production, fibrosis, and the activation of NOX4-MAPK signaling. The results suggest that high lipid and glucose may play a significant role in DKD progression, while Rg1 may attenuate renal fibrosis by inhibiting NOX4-MAPK signaling.

Inhibition of NLRP1 inflammasome improves autophagy dysfunction and Aß disposition in APP/PS1 mice.

Increasing evidence has shown that the NOD-like receptor protein 1 (NLRP1) inflammasome is associated with Aß generation and deposition, which contributes to neuronal damage and neuronal-inflammation in Alzheimer's disease (AD). However, the specific mechanism of NLRP1 inflammasome in the pathogenesis of AD is still unclear. It has been reported that autophagy dysfunction can aggravate the pathological symptoms of AD and plays an important role in regulating Aß generation and clearance. We hypothesized that NLRP1 inflammasome activation may induce autophagy dysfunction contributing to the progression of AD. In the present study, we observed the relationship between Aß generation and NLRP1 inflammasome activation, as well as AMPK/mTOR mediated-autophagy dysfunction in WT 9-month-old (M) mice, APP/PS1 6 M and APP/PS1 9 M mice. Additionally, we further studied the effect of NLRP1 knockdown on cognitive function, Aß generation, neuroinflammation and AMPK/mTOR mediated autophagy in APP/PS1 9 M mice. Our results indicated that NLRP1 inflammasome activation and AMPK/mTOR mediated-autophagy dysfunction are closely implicated in Aß generation and deposition in APP/PS1 9 M mice, but not in APP/PS1 6 M mice. Meanwhile, we found that knockdown of NLRP1 significantly improved learning and memory impairments, decreased the expressions of NLRP1, ASC, caspase-1, p-NF-κB, IL-1ß, APP, CTF-ß, BACE1 and Aß1-42, and decreased the level of p-AMPK, Beclin 1 and LC3 II, and increased the level of p-mTOR and P62 in APP/PS1 9 M mice. Our study suggested that inhibition of NLRP1 inflammasome activation improves AMPK/mTOR mediated-autophagy dysfunction, resulting in the decrease of Aß generation, and NLRP1 and autophagy might be important targets to delay the progression of AD.

Trpc6 knockout improves behavioral dysfunction and reduces Aß production by inhibiting CN-NFAT1 signaling in T2DM mice.

As the prevalence of diabetes and health awareness increase, type 2 diabetes mellitus -associated cognitive dysfunction is receiving increasing attention. However, the pathogenesis is not entirely understood. Transient receptor potential cation channel 6 (TRPC6) is highly correlated with intracellular Ca2+ concentrations, and neuronal calcium overload is an important cause of cognitive dysfunction. In the present study, we investigated the effect and mechanism of Trpc6 knockout in high-fat diet and streptozotocin-induced T2DM mice. The body weight and fasting blood glucose were recorded during the experiment. Behavioral dysfunction was detected using the open field test (OFT), elevated plus maze (EPM), hole-board test (HBT), Morris water maze (MWM) test and contextual fear conditioning (CFC) test. Nissl and H&E staining were used to examine neuronal damage. Western blot, quantitative real-time polymerase chain reaction (q-PCR), and immunofluorescence were performed to detect amyloid beta protein (Aß) deposition and related indicators of neurological impairments in the cerebral cortex and hippocampus. The results indicated that Trpc6 knockout inhibited body weight loss and fasting blood glucose increase, improved spontaneous activity, learning and memory dysfunction, and alleviated neuroinflammation and neuronal damage in T2DM mice. The further results demonstrated that Trpc6 knockout decreased Aß generation and deposition, and reduced the expressions of inflammasome-related proteins in T2DM mice. In addition, Trpc6 knockout inhibited intracellular calcium overload in diabetic mice and primary cultured hippocampal neurons, which in turn suppressed CN and NFAT1 expression. These data suggest that Trpc6 knockout may inhibit the CN-NFAT1 signaling pathway by decreasing intracellular calcium overload in the brain of T2DM mice, which consequently reduce Aß deposition and neuroinflammation, and ultimately delay the development of T2DM-associated cognitive dysfunction.

Phosphoethanolamine cytidylyltransferase ameliorates mitochondrial function and apoptosis in hepatocytes in T2DM in vitro.

Liver function indicators are often impaired in patients with type 2 diabetes mellitus (T2DM), who present higher concentrations of aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transferase than individuals without diabetes. However, the mechanism of liver injury in patients with T2DM has not been clearly elucidated. In this study, we performed a lipidomics analysis on the liver of T2DM mice, and we found that phosphatidylethanolamine (PE) levels were low in T2DM, along with an increase in diglyceride, which may be due to a decrease in the levels of phosphoethanolamine cytidylyltransferase (Pcyt2), thus likely affecting the de novo synthesis of PE. The phosphatidylserine decarboxylase pathway did not change significantly in the T2DM model, although both pathways are critical sources of PE. Supplementation with CDP-ethanolamine (CDP-etn) to increase the production of PE from the CDP-etn pathway reversed high glucose and FFA (HG&FFA)-induced mitochondrial damage including increased apoptosis, decreased ATP synthesis, decreased mitochondrial membrane potential, and increased reactive oxygen species, whereas supplementation with lysophosphatidylethanolamine, which can increase PE production in the phosphatidylserine decarboxylase pathway, did not. Additionally, we found that overexpression of PCYT2 significantly ameliorated ATP synthesis and abnormal mitochondrial morphology induced by HG&FFA. Finally, the BAX/Bcl-2/caspase3 apoptosis pathway was activated in hepatocytes of the T2DM model, which could also be reversed by CDP-etn supplements and PCYT2 overexpression. In summary, in the liver of T2DM mice, Pcyt2 reduction may lead to a decrease in the levels of PE, whereas CDP-etn supplementation and PCYT2 overexpression ameliorate partial mitochondrial function and apoptosis in HG&FFA-stimulated L02 cells.

Ginsenoside Rg1 attenuates glomerular fibrosis by inhibiting CD36/TRPC6/NFAT2 signaling in type 2 diabetes mellitus mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginsenoside Rg1 (Rg1) is one of the main active components in Panax ginseng C. A. Meyer (ginseng), which has been widely used to delay senescence or improve health conditions for more than 2000 years. Increasing studies have revealed that Rg1 could regulate cell proliferation and differentiation, as well as anti-inflammatory and anti-apoptotic effects, and might have protective effects on many chronic kidney diseases. AIM OF THE STUDY: Diabetic nephropathy (DN) is one of the most dangerous microvascular complications of diabetes and is the leading cause of end-stage renal disease worldwide. However, the role and mechanism of Rg1 against high-glucose and high-fat-induced glomerular fibrosis in DN are not clear. This study aimed to investigate the protective effect of Rg1 on DN and its possible mechanism. MATERIALS AND METHODS: The type 2 diabetes mellitus (T2DM) mice models were established with a high-fat diet (HFD) combined with an intraperitoneal injection of streptozotocin (STZ). Urine protein and serum biochemical indexes were detected by corresponding kits. The kidney was stained with H&E, PAS, and Masson to observe the pathological morphology, glycogen deposition, and fibrosis. The expression of CD36 and p-PLC in the kidney cortex was detected by IHC. The expressions of FN and COL4 were detected by IF. Western blot and PCR were performed to examine protein and mRNA expressions of kidney fibrosis and TRPC6/NFAT2-related pathways in DN mice. Calcium imaging was used to examine the effect of Rg1 on [Ca2+]i in PA + HG-induced human mesangial cells (HMCs). Visualization of the interaction between Rg1 and CD36 was detected by molecular docking. RESULTS: Rg1 treatment for 8 weeks could prominently decrease urinary protein, serum creatinine, and urea nitrogen and downgrade blood lipid levels and renal lipid accumulation in T2DM mice. The pathological results indicated that Rg1 treatment attenuated renal pathological injury and glomerular fibrosis. The further results demonstrated that Rg1 treatment remarkably decreased the expressions of CD36, TRPC6, p-PLC, CN, NFAT2, TGF-ß, p-Smad2/3, COL4, and FN in renal tissues from T2DM mice. Calcium imaging results found that Rg1 downgraded the base levels of [Ca2+]i and ΔRatioF340/F380 after BAPTA and CaCl2 treatment. Molecular docking results showed that Rg1 could interact with CD36 with a good affinity. CONCLUSION: These results revealed that Rg1 could ameliorate renal lipid accumulation, pathological damage, and glomerular fibrosis in T2DM mice. The mechanism may be involved in reducing the overexpression of CD36 and inhibiting the TRPC6/NFAT2 signaling pathway in renal tissues of T2DM mice.

Ginsenoside Rg1 alleviates learning and memory impairments and Aß disposition through inhibiting NLRP1 inflammasome and autophagy dysfunction in APP/PS1 mice.

Alzheimer's disease (AD) is a common neurodegenerative disorder. Amyloid ß (Aß) deposition is considered an important pathological feature of AD. Growing evidence has linked neuroinflammation and autophagy to Aß deposition in the progression of AD. However, there are few drug options for inhibiting neuroinflammation and autophagy to prevent AD. Ginsenoside Rg1 (Rg1), a steroidal saponin extracted from ginseng, has been reported to possess multiple neuroprotective effects. The present study aimed to evaluate whether Rg1 treatment could attenuate cognitive disorders and neuronal injuries by inhibiting NLRP1 inflammasome and autophagy dysfunction in an AD model of APP/PS1 mice. The results of behavioral tests indicated that Rg1 treatment for 12 weeks could significantly improve olfactory dysfunction as well as learning and memory impairments. The results of histopathological tests indicated that Rg1 treatment could reduce Aß deposition and neuronal damages in APP/PS1­9M mice. Additionally, the results of immunoblot, reverse transcription­quantitative PCR or immunohistochemistry demonstrated that Rg1 treatment significantly downregulated the expression levels of inflammation­related proteins of NLRP1, caspase1, IL­1ß and TNF­α, as well as autophagy­related proteins of p­AMPK/AMPK, Beclin1 and LC3 II/LC3 I, and increased the expression levels of p­mTOR/mTOR and P62 in APP/PS1­9M mice. In addition, the molecular docking analysis showed that there was favorable binding result between Rg1 and NLRP1. The present study suggested that Rg1 may alleviate learning and memory impairments and Aß disposition by inhibiting NLRP1 inflammasome and improving autophagy dysfunction, suggesting that Rg1 may be a potential therapeutic agent for delaying AD.

Comprehensive Analysis of Long Non-Coding RNAs N4-Acetylcytidine in Alzheimer's Disease Mice Model Using High-Throughput Sequencing.

BACKGROUND: N4-acetylcytidine (ac4C), an important posttranscriptional modification, is involved in various disease processes. Long noncoding RNAs (lncRNAs) regulate gene expression mainly through epigenetic modification, transcription, and posttranscriptional modification. Alzheimer's disease (AD) is a neurodegenerative disease characterized by amyloidosis of the brain. However, the role of lncRNA ac4C modification in AD remains unclear. OBJECTIVE: In this study, we investigated the association between ac4C modification and AD, and the underlying mechanisms of ac4C modification in AD. METHODS: The male 9-month-old APP/PS1 double transgenic mice, age- and sex-matched wild type (WT) mice were used in this study. Then, ac4C-RIP-seq and RNA-seq were used to comprehensively analyze lncRNA ac4C modification in AD mice. The lncRNA-miRNA-mRNA regulatory networks using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed the regulatory relationships among these three lncRNAs and AD. RESULTS: The results showed that there were 120 significantly different ac4C peaks located on 102 lncRNAs in AD, of which 55 were hyperacetylated and 47 were hypoacetylated. Simultaneously, 231 differentially expressed lncRNAs were identified, including 138 upregulated lncRNAs and 93 downregulated lncRNAs. Moreover, 3 lncRNAs, lncRNA Gm26508, lncRNA A430046D13Rik, and lncRNA 9530059O14Rik, showed significant changes in both the ac4C and RNA levels using conjoint analysis. CONCLUSION: The abundance of lncRNA ac4C modification is significantly different in AD and indicates that lncRNA ac4C is associated with the occurrence and development of AD, which could provide a basis for further exploration of the related regulatory mechanisms.

Chronic glucocorticoid exposure accelerates Aß generation and neurotoxicity by activating calcium-mediated CN-NFAT1 signaling in hippocampal neurons in APP/PS1 mice.

Glucocorticoid (GC) exposure can lead to deterioration of the structure and function of hippocampal neurons and is closely involved in Alzheimer's disease (AD). Amyloid-ß (Aß) overproduction is an important aspect of AD pathogenesis. Our study mainly investigated the mechanism of chronic GC exposure in accelerating Aß production in primary cultured hippocampal neurons from APP/PS1 mice. The results indicated that chronic dexamethasone (DEX, 1 µM) significantly accelerated neuronal damage and Aß accumulation in hippocampal neurons from APP/PS1 mice. Meanwhile, DEX exposure markedly upregulated APP, NCSTN, BACE1 and p-Tau/Tau expression in hippocampal neurons from APP/PS1 mice. Our study also indicated that chronic DEX exposure significantly increased intracellular Ca2+ ([Ca2+]i) levels and the expressions of p-PLC, CN and NFAT1 in hippocampal neurons from APP/PS1 mice. We further found that stabilizing intracellular calcium homeostasis with 2-APB (50 µM) and SKF-96365 (10 µM) significantly alleviated neuronal damage and Aß accumulation in chronic DEX-induced hippocampal neurons from APP/PS1 mice. Additionally, dual luciferase assays showed that NFAT1 upregulated NCSTN transactivation, which was further increased upon DEX treatment. This study suggests that chronic DEX exposure accelerates Aß accumulation by activating calcium-mediated CN-NFAT1 signaling in hippocampal neurons from APP/PS1 mice, which may be closely related to the acceleration of AD.

Ginsenoside Rg1 attenuates cerebral ischemia-reperfusion injury due to inhibition of NOX2-mediated calcium homeostasis dysregulation in mice.

Background: The incidence of ischemic cerebrovascular disease is increasing in recent years and has been one of the leading causes of neurological dysfunction and death. Ginsenoside Rg1 has been found to protect against neuronal damage in many neurodegenerative diseases. However, the effect and mechanism by which Rg1 protects against cerebral ischemia-reperfusion injury (CIRI) are not fully understood. Here, we report the neuroprotective effects of Rg1 treatment on CIRI and its possible mechanisms in mice. Methods: A bilateral common carotid artery ligation was used to establish a chronic CIRI model in mice. HT22 cells were treated with Rg1 after OGD/R to study its effect on [Ca2+]i. The open-field test and pole-climbing experiment were used to detect behavioral injury. The laser speckle blood flowmeter was used to measure brain blood flow. The Nissl and H&E staining were used to examine the neuronal damage. The Western blotting was used to examine MAP2, PSD95, Tau, p-Tau, NOX2, PLC, p-PLC, CN, NFAT1, and NLRP1 expression. Calcium imaging was used to test the level of [Ca2+]i. Results: Rg1 treatment significantly improved cerebral blood flow, locomotion, and limb coordination, reduced ROS production, increased MAP2 and PSD95 expression, and decreased p-Tau, NOX2, p-PLC, CN, NFAT1, and NLRP1 expression. Calcium imaging results showed that Rg1 could inhibit calcium overload and resist the imbalance of calcium homeostasis after OGD/R in HT22 cells. Conclusion: Rg1 plays a neuroprotective role in attenuating CIRI by inhibiting oxidative stress, calcium overload, and neuroinflammation.

Expression of serum miR-126 in patients with intracranial aneurysm and its relationship with postoperative cerebral vasospasm.

OBJECTIVE: To examine the expression of serum miR-126 in patients with intracranial aneurysm and to explore its relationship with postoperative cerebral vasospasm. METHODS: In this retrospective study, 85 patients with intracranial aneurysms diagnosed and treated in our hospital were enrolled into the research group (RG), and 83 healthy volunteers who came to our hospital for physical examination were selected as the control group (CG). The serum miR-126 expression in both groups was examined by RT-PCR, and the relationship between the diagnostic value of miR-126 for intracranial aneurysm and postoperative cerebral vasospasm was analyzed. The serum inflammatory related factors in the patients were tested, and their correlation with miR-126 was assessed. The risk factors of postoperative cerebral vasospasm were evaluated by multiple factors. RESULTS: The serum miR-126 expression in patients with intracranial aneurysm was obviously lower than that of participants in CG (P<0.05), and the AUC of miR-126 in diagnosing intracranial aneurysm was 0.945, which was of high diagnostic value. Serum inflammatory factors TNF-α and IL-6 were highly expressed in the serum of patients with intracranial aneurysm, which were positively correlated with the miR-126 level (P<0.05). After operation, the serum miR-126 level in patients with cerebral vasospasm was obviously higher than that of those without cerebral vasospasm, and the AUC of miR-126 for predicting cerebral vasospasm after operation was 0.859. Logistic regression analysis revealed that preoperative bleeding frequency, history of hypertension, Hunt-Hess grade and high expression of miR-126 were independent risk factors for cerebral vasospasm after operation in patients with intracranial aneurysm. CONCLUSION: miR-126 is highly expressed in the serum of patients with intracranial aneurysm, so it may be used as a potential biomarker for the diagnosis of patients with intracranial aneurysm and the prediction of cerebral vasospasm after operation.