HMGA2 Promotes Brain Injury in Rats with Cerebral Infarction by Activating TLR4/NF-κB Signaling Pathway.

Cerebral infarction is a common disease with a higher disability and fatality rates. The incidence rates of cerebral infarction or cerebral ischemic stroke gradually increase with aging and cerebrovascular disease progression. This study is aimed at evaluating the effects of HMGA2 on cerebral infarction-induced brain tissue damage and its underlying mechanisms. Adult Sprague Dawley rats were pretreated with sh-HMGA2 before cerebral infarction operation. The effect of HMGA2 on the arrangement, distribution, and morphological structure of neurons and the cell apoptosis ratio in brain tissue were detected via hematoxylin and eosin staining, brain-water content, TTC staining, and TUNEL staining. The results from ELISA assay, qPCR, and western blot indicated that downregulation of HMGA2 mitigated inflammatory stress via regulating the expression of TLR4/NF-κB. In addition, results showed that suppressed HMGA2 attenuated the neurological dysfunction of brain injury rats and markedly reduced infarct volume. HMGA2 might be able to alleviate the damage associated with cerebral infarction-induced inflammatory response and cell apoptosis. Moreover, downregulation of HMGA2 had a protective effect on the brain damage derived from cerebral infarction by mediating the TLR4/NF-κB pathway. In conclusion, the current study demonstrated that downregulation of HMGB2 decreased the infarct size, inflammatory responses, and apoptosis in cerebral injury and further had neuroprotective effects against cerebral infarction-induced brain damage. Finally, these results indicated that the downregulation of the TLR4/NF-κB pathway after ischemia by HMGB2 inhibition is a potential mechanism of the neuroprotective effect of cerebral injury.

Analysis of the expression levels of chemerin, ox-LDL, MMP-9, and PAPP-A in ICVD patients and their relationship with the severity of neurological impairment.

OBJECTIVE: The study aimed to analyze the relationship between expression levels of chemerin, oxidized low density lipoprotein (ox-LDL), matrix metalloproteinase 9 (MMP-9) and pregnancy associated plasma protein A (PAPP-A) in ischemic cerebrovascular disease (ICVD) patients and the relationship between the mentioned indicators and the degree of neurological impairment. METHODS: From January 2020 to February 2021, a total of 328 cases of ICVD patients were admitted to our hospital, and 240 cases of healthy people (control group) were prospectively recruited into this study. The 328 patients were divided into 2 ischemic subtypes, with 233 cases as acute cerebral infarction (ACI) and 95 cases as transient ischemic attack (TIA). Laboratory tests were compared among the groups. Spearman rank correlation was used to analyze the correlation between chemerin, ox-LDL, MMP-9, PAPP-A levels and neurological deficit. Unconditional logisitic regression was used to analyze the risk factors for neurological deficits. RESULTS: The high density lipoprotein cholesterol (HDL-C), fasting plasma glucose (FPG), chemerin, ox-LDL, MMP-9, and PPAP-A levels in the ACI group were significantly higher than those in the TIA group and control group (p < 0.05, respectively), while the levels of the mentioned indicators in the TIA group were significantly higher than those in control group (p < 0.05, respectively). The levels of the given indicators decreased successively in the severe, moderate, and mild neurological deficits population and control group, with statistical difference. Spearman rank correlation analysis showed that chemerin, ox-LDL, MMP-9, and PPAP-A levels were positively correlated with the degree of neurological deficit in ICVD patients. Unconditional logistic regression analysis showed that chemerin, ox-LDL, MMP-9, and PPAP-A were the independent risk factors for neurological deficit in patients with ICVD. CONCLUSION: LDL-C, FPG, chemerin, ox-LDL, MMP-9, and PPAP-A were highly expressed in ACI and neurological deficit patients. Chemerin, ox-LDL, MMP-9, and PPAP-A may be the independent risk factors for neurological deficit in patients with ICVD.

CERKL alleviates ischemia reperfusion-induced nervous system injury through modulating the SIRT1/PINK1/Parkin pathway and mitophagy induction.

Recent studies showed that Ceramide Kinase-Like Protein (CERKL)was expressed in the nerve cells and could regulate autophagy. Sirtuin-1 (SIRT1) is the regulator of the mitophagy, which can be stabilized by CERKL. Furthermore, the study also revealed that the SIRT1 induced mitophagy by activating PINK1/Parkin signaling. Therefore, we speculated that CERKL has potential to activate the SIRT1/PINK1/Parkin pathway to induce mitophagy. In this study, cerebral ischemia reperfusion mouse model was established. CERKL was overexpressed in those mice and human neuroblastoma cells. Tunel staining and flow cytometry were applied for the detection of cell apoptosis. The ratios of LC3Ⅱ to LC3Ⅰ and the expression of LC3Ⅱ in mitochondria were determined by gel electrophoresis. Overexpression of CERKL alleviated the cerebral ischemia reperfusion injury and damage to OGD/R human neuroblastoma cells. Overexpression of CERKL enhanced the expression of LC3 Ⅱ in mitochondria and induced occurrence of mitophagy. Overexpression of CERKL promoted the stability of SIRT1 and facilitated the expression of PINK1 and Parkin in those cells. Knockdown of PINK1 impeded the mitophagy and suppressed the expression of LC3 Ⅱ in mitochondria. It can be concluded that CERKL alleviated the ischemia reperfusion induced nervous system injury through inducing mitophagy in a SIRT1/PINK1/Parkin dependent pathway.

Effects of chemerin and homocysteine levels and their associations with occurrence and development of ischemic cerebrovascular disease.

BACKGROUND: The current study was conducted to explore the effects of chemerin and homocysteine (Hcy) levels and their associations with the occurrence and development of ischemic cerebrovascular disease (ICVD). METHODS: There involved a total of 187 patients with ICVD and 190 healthy people for physical examination in Cangzhou Central hospital from January 2020 to April 2021. The participants enrolled were divided into four groups based on the digital subtraction angiography: mild stenosis group (64 cases, stenosis rate 30-49 %), moderate stenosis group (72 cases, stenosis rate 50-69 %), severe stenosis group (51 cases, stenosis rate 70-99 %) and control group (190 cases, in healthy condition). The laboratory indexes of ICVD group and control group were observed and the four groups were further compared. Pearson linear correlation was applied to analyze the link between chemerin and Hcy levels and the degree of cerebral vascular stenosis in ICVD patients, and multivariate logistic regression was used to analyze the influencing factors of ICVD. RESULTS: No significant difference was found in general information including age, gender, body mass index (BMI), heart rate, systolic blood pressure, diastolic blood pressure, smoking and drinking between the two groups (P > 0.05). Moreover, there was no significant difference in fasting blood glucose (FBG), total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) levels between the two groups (P > 0.05). However, the levels of triglyceride (TG), low density lipoprotein cholesterol (LDL-C), chemerin and Hcy in ICVD group were significantly higher than those in control group (P < 0.05). When comparing the four groups, there was no significant difference in FBG and TC levels (P > 0.05). The levels of TG, LDL-C, chemerin and Hcy in mild, moderate and severe stenosis groups were higher than those in control group, the above levels in moderate and severe stenosis group were higher than those in mild stenosis group, and severe stenosis group higher than moderate stenosis group (P < 0.05). Chemerin and Hcy levels were positively correlated with the degree of cerebral vascular stenosis in ICVD patients (r = 0.612, 0.519, P < 0.001). ICVD was regarded as the dependent variable, and the abovementioned general data as well as significant laboratory indicators, including TG, LDL-C, chemerin and Hcy, as independent variables. The results of multivariate logistic regression analysis revealed that TG, LDL-C, chemerin and Hcy were independent influencing factors of ICVD. CONCLUSIONS: Chemerin and Hcy levels exerted a close link to the occurrence and development of ICVD as independent influencing factors.

A systematic review and meta-analysis on the efficacy of statins in the treatment of atherosclerosis.

BACKGROUND: It was a meta-analysis on the efficacy of statins in the treatment of atherosclerosis. METHODS: The PubMed, Medline, Embase, Web of Sciences, and other Chinese and English databases were used to retrieve literature on randomized controlled trials (RCTs) of statins in the treatment of atherosclerosis, published from January 2000 to January 2021. The Cochrane Handbook for Systematic Reviews of Intervention 5.0.2 was used to conduct bias risk assessment, and Review Manager 5.3 software (RevMan) was used for meta-analysis. RESULTS: A total of 12 articles with 1,180 participants were included in the meta-analysis. In the observation group, the plaque area [mean difference (MD) =-1.21; 95% confidence interval (CI): -2.03 to -0.38; Z =2.87; P=0.004], total cholesterol (TC) level (MD =-0.72; 95% CI: -1.01 to -0.43; Z =4.83; P<0.00001), triglyceride (TG) level (MD =-0.43; 95% CI: -0.76 to -0.09; Z =2.51; P=0.01), and the low-density lipoprotein (LDL-C) level (MD =-0.79; 95% CI: -1.41 to -0.18; Z =2.54; P=0.01) were lower, while the clinical effective rate (MD =3.64; 95% CI: 1.39 to 9.53; Z =2.64; P=0.008) was higher, and the difference was notable. No notable difference was noted in intra-media thickness (IMT) (MD =-0.41; 95% CI: -0.88 to -0.06; Z =1.7; P=0.09), hypersensitive C-reactive protein (hs-CRP) level (MD =-1.61; 95% CI: -3.59 to 0.37; Z =1.7; P=0.09), and high-density lipoprotein (HDL-C) level (MD =0.14; 95% CI: -0.02 to 0.30; Z =2.54; P=0.09) between the 2 groups. DISCUSSION: The use of statins in the treatment of atherosclerosis can reduce the levels of TC, TG, and LDL-C, mitigate clinical symptoms, and reduce blood lipids with good efficacy.

Atractylenolide III reduces NLRP3 inflammasome activation and Th1/Th2 imbalances in both in vitro and in vivo models of asthma.

Paediatric asthma is a common inflammatory disease in children. Atractylenolide III is an active component of the Atractylodes rhizome, an herbal medicine that has been used as an asthma treatment. This study aimed to explore the effects and underlying mechanisms of atractylenolide III in IL-4-induced 16HBE cells and ovalbumin-induced asthmatic mice. The results showed that IL-4 stimulation significantly decreased, and atractylenolide III treatment increased, growth and apoptosis of 16HBE cells. In 16HBE cells, administration of atractylenolide III also significantly suppressed the IL-4-induced increases in the expression of cleaved caspase-1; apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC); and nucleotide-binding domain and leucine-rich repeat protein 3 (NLRP3). Moreover, the numbers of total leukocytes, neutrophils, eosinophils, and macrophages significantly increased in ovalbumin-induced mice, and then decreased after atractylenolide III treatment. In ovalbumin-induced asthmatic mice, atractylenolide III treatment also significantly inhibited NLRP3 inflammasome activation and restored the Th1/Th2 balance. These results indicate that atractylenolide III reduced NLRP3 inflammasome activation and regulated the Th1/Th2 balance in IL-4 induced 16HBE cells and ovalbumin-induced asthmatic mice, suggesting it has a protective effect that may be useful in the treatment of paediatric asthma.

N6-(2-hydroxyethyl)-adenosine from Cordyceps cicadae attenuates hydrogen peroxide induced oxidative toxicity in PC12 cells.

N6-(2-hydroxyethyl)-adenosine (HEA), is one of the active molecule found in Cordyceps cicadae. The protective effect of HEA against H2O2 induced oxidative damage in PC12 cells and the mechanism of action was investigated. The cells were exposed to varying concentrations of HEA (5-40 µM) for a period of 24 h and further incubated with 100 µM of H2O2 for an another 12 h. Cell viability, LDH release, MMP collapse, Ca2+ overload, antioxidant parameters (reactive oxygen species generation (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), inflammatory mediators (interleukins 6 and 1ß (IL-6 and IL-1ß), tumor necrosis factor alpha (TNF-α) and NF-kB were evaluated. The results obtained showed that cells exposed to H2O2 toxicity showed reduced cell viability, increased LDH, ROS and Ca2+ overload. However, prior treatment of PC12 cells with HEA increased cell viability, reduced LDH release, MMP collapse, Ca2+ overload and ROS generation induced by H2O2 toxicity. Furthermore, HEA also increased the activities of antioxidant enzymes and inhibited lipid peroxidation as well as reduced IL-6, IL-1ß, TNF-α and NF-kB. Thus, our results provided insight into the attenuative effect of HEA against H2O2 induced cell death through its antioxidant action by reducing ROS generation, oxidative stress and protecting mitochondrial function.

Oleanolic acid protects against cognitive decline and neuroinflammation-mediated neurotoxicity by blocking secretory phospholipase A2 IIA-activated calcium signals.

Neuroinflammation causes neurotoxic injury and underlies the pathogenesis of neurodegenerative disorders including Alzheimer's disease (AD). Astrocytes are the predominant immunoregulatory cells in AD. Oleanolic acid (OA) is a promising anti-inflammatory therapeutic agent that can ameliorate cerebral damage in ischemic environments, but its role in AD remains poorly elucidated. Here, preconditioning with OA inhibited the transcription and secretion of inflammatory cytokines IL-6, TNF-α, and IL-1ß in amyloid-beta peptide (Aß)-activated astrocytes. Moreover, OA ameliorated primary neuron death triggered by incubation in conditioned medium from Aß-treated astrocytes. Furthermore, OA also suppressed Aß-induced expression and production of group IIA secretory phospholipase A2 (sPLA2-IIA) in astrocytes. Supernatants supplemented with exogenous sPLA2-IIA reversed the protective role of OA against astrocyte activation-mediated neurotoxicity by suppressing cell viability and increasing LDH release, apoptosis, the contents of neurotoxic mediator arachidonic acid, and prostaglandin D2. Simultaneously, treatment with sPLA2 inhibitor aristolochic acid also counteracted neurotoxicity induced by Aß-activated astrocytes through increasing cell viability, inhibiting cell apoptosis, and reducing the releases of arachidonic acid and prostaglandin D2. Additionally, OA restrained Ca2+ influx in neurons after incubation with supernatants from Aß-activated astrocytes, which was abrogated by adding sPLA2-IIA. Activating Ca2+ signaling with BayK, an L-type Ca2 + channel agonist, reversed the beneficial role of OA against neurotoxicity induced by astrocyte activation-mediated inflammatory response. OA also ameliorated cognitive deficits in an adolescent rat model of Aß-evoked AD. These findings confirm that OA abrogates neuroinflammation and subsequent neurotoxicity induced by conditioned media from Aß-activated astrocytes in sPLA2-IIA mediated-calcium signals. Therefore, OA may protect neurons from injury caused by neighboring astrocyte activation in AD, indicating a promising therapeutic strategy against AD.

TWEAK/Fn14 interaction induces proliferation and migration in human airway smooth muscle cells via activating the NF-κB pathway.

Asthma, an increasingly common chronic disease among children, are characterized by airway remodeling, which is partly attributed to the proliferation and migration of airway smooth muscle cell (ASMC). The purpose of the present study was to investigate potential roles and mechanisms of the tumor necrosis factor-like weak inducer of apoptosis (TWEAK)/fibroblast growth factor-inducible molecule 14 (Fn14) axis on cell proliferation and migration in HASMCs. Compared to HASMCs from non-asthmatic patients, those from asthmatic patients showed elevated expression levels of both Fn14 and TWEAK. Additionally, similar to the response triggered by platelet-derived growth factor-BB, stimulation with recombinant TWEAK strongly induced cell proliferation and migration in HASMCs. However, depletion of Fn14 remarkably abrogated the enhancement of TWEAK on the cell proliferation and migration of HASMCs. Furthermore, treatment with TWEAK led to the activation of NF-κB. This effect was eliminated by silencing Fn14, indicating that TWEAK-induced NF-κB signaling was mediated via Fn14. Moreover, the TWEAK/Fn14 interaction promoted cell proliferation and migration. These effects were blocked by NF-κB inhibitor SN50, which suggest that the TWEAK/Fn14 signaling system partially depends on NF-κB activity. Collectively, we demonstrated that the TWEAK/Fn14 axis accelerated HASMC cell proliferation and migration by activating the NF-κB pathway, thereby exacerbating airway remodeling in asthma. Altogether, these findings indicate a novel role for the TWEAK/Fn14/NF-κB pathway as a potent option for limiting airway remodeling in asthma.

Neuroprotective Effects of Pycnogenol Against Oxygen-Glucose Deprivation/Reoxygenation-Induced Injury in Primary Rat Astrocytes via NF-κB and ERK1/2 MAPK Pathways.

BACKGROUNDS/AIMS: Pycnogenol (PYC) is a patented mix of bioflavonoids with potent anti-oxidant and anti-inflammatory properties. In this study, we investigated the effects of PYC on oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury in primary rat astrocytes. METHODS: The primary rat astrocytes were randomly divided into 6 groups, blank control, OGD/R, OGD/R+PYC (10, 20, 40, and 60 µg/mL). The cell activity were detected by MTT and LDH assays, then the levels of oxidant products [malondialdehyde (MDA) and reactive oxygen species (ROS)] , antioxidants [superoxide dismutase (SOD)], mitochondrial membrane potential (MMP) and inflammatory cytokines were detected. In addition, the expression levels of apoptosis-related proteins (Bax, Bcl-2 and Cleaved caspase 3), proinflammatory factors (NF-κB p65), and p-ERK1/2 were measured by Western blot analysis. RESULTS: The results showed that PYC incubation dose-dependently attenuated cell viability loss, LDH leakage, oxidative stress, inflammatory cytokines accumulation and cell apoptosis caused by OGD/R. Furthermore, PYC pretreatment dose-dependently suppressed OGD/R-induced NF-κB p65 nuclear translocation, NF-κB activity and ERK1/2 phosphorylation. Similarly to PYC, NF-κB inhibitor PDTC and ERK1/2 inhibitor PD098059 dramatically inhibited OGD/R-induced NF-κB activation, ERK1/2 phosphorylation, and ROS production, as well as TNF-α secretion. CONCLUSIONS: These findings revealed that PYC has neuroprotective effects against OGD/R-induced injury via NF-κB and ERK1/2 pathways in primary rat astrocytes.