Dual Versus Mono Antiplatelet Therapy in Patients with Acute Mild-to-Moderate Stroke: A Multicentre Perspective Cohort Study.

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the association between different antiplatelet therapy regimens and the functional outcomes and bleeding complications among mild-to-moderate ischaemic stroke patients based on real-world data. METHODS: We used data from the SEACOAST trial (Safety and efficacy of aspirin-clopidogrel in acute noncardiogenic minor ischaemic stroke) to analyse the data of patients with mild-to-moderate stroke within 72 h after onset who were treated with aspirin or clopidogrel alone or a combination of clopidogrel and aspirin from September 2019 to November 2021. Propensity score matching (PSM) was used to balance the differences between groups. We performed an analysis to evaluate the association of different antiplatelet regimens and 90-day disability, which was defined as a modified Rankin Scale score ≥2, as well as disability ascribed to index or recurrent stroke by the local investigator. In terms of safety, we then compared the bleeding events between the two groups. RESULTS: A total of 2822 mild-to-moderate ischaemic stroke patients were treated with either clopidogrel plus aspirin (n = 1726, 61.2%) or aspirin/clopidogrel (n = 1096, 38.8%). Of 1726 patients in the dual antiplatelet group, 1350 (78.5%) received less than or equal to 30 days of combined therapy. At 90 days, 433 (15.3%) patients were disabled. Patients who received combined therapy had a lower overall disability rate (13.7% versus 17.9%; OR 0.78 (0.6-1.01); P = 0.064). However, investigators found that index stroke was the reason for significantly fewer patients in the dual antiplatelet group having disability (8.4% versus 12%; OR, 0.72 (0.52-0.98); P = 0.038). There was no statistically significant difference in the incidence of moderate to severe bleeding complications between the dual and mono antiplatelet drug regimens (0.4% versus 0.2%; HR 1.5 (0.25, 8.98); P = 0.657). CONCLUSION: Aspirin plus clopidogrel was associated with a reduction in the incidence of disability attributed to index stroke. There was no statistically significant difference in the incidence of moderate to severe bleeding complications between the two antiplatelet drug regimens. TRIAL REGISTRATION NUMBER: ChiCTR1900025214.

CSF2RB overexpression promotes the protective effects of mesenchymal stromal cells against ischemic heart injury.

Aims: The invasive intramyocardial injection of mesenchymal stromal cells (MSCs) allows for limited repeat injections and shows poor therapeutic efficacy against ischemic heart failure. Intravenous injection is an alternative method because this route allows for repeated, noninvasive, and easy delivery. However, the lack of targeting of MSCs hinders the ability of these cells to accumulate in the ischemic area after intravenous injections. We investigated whether and how the overexpression of colony-stimulating factor 2 receptor beta subunit (CSF2RB) may regulate the cardiac homing of MSCs and their cardioprotective effects against ischemic heart failure. Methods and Results: Adult mice were subjected to myocardial ischemia/reperfusion (MI/R) or sham operations. We observed significantly higher CSF2 protein expression and secretion by the ischemic heart from 1 day to 2 weeks after MI/R. Mouse adipose tissue-derived MSCs (ADSCs) were infected with adenovirus harboring CSF2RB or control adenovirus. Enhanced green fluorescent protein (EGFP)-labeled ADSCs were intravenously injected into MI/R mice every three days for a total of 7 times. Compared with ADSCs infected with control adenovirus, intravenously delivered ADSCs overexpressing CSF2RB exhibited markedly increased cardiac homing. Histological analysis revealed that CSF2RB overexpression significantly enhanced the ADSC-mediated proangiogenic, antiapoptotic, and antifibrotic effects. More importantly, ADSCs overexpressing CSF2RB significantly increased the left ventricular ejection fraction and cardiac contractility/relaxation in MI/R mice. In vitro experiments demonstrated that CSF2RB overexpression increases the migratory capacity and reduces the hypoxia/reoxygenation-induced apoptosis of ADSCs. We identified STAT5 phosphorylation as the key mechanism underlying the effects of CSF2RB on promoting ADSC migration and inhibiting ADSC apoptosis. RNA sequencing followed by cause-effect analysis revealed that CSF2RB overexpression increases the expression of the ubiquitin ligase RNF4. Coimmunoprecipitation and coimmunostaining experiments showed that RNF4 binds to phosphorylated STAT5. RNF4 knockdown reduced STAT5 phosphorylation as well as the antiapoptotic and promigratory actions of ADSCs overexpressing CSF2RB. Conclusions: We demonstrate for the first time that CSF2RB overexpression optimizes the efficacy of intravenously delivered MSCs in the treatment of ischemic heart injury by increasing the response of the MSCs to a CSF2 gradient and CSF2RB-dependent STAT5/RNF4 activation.

Fibroblast-specific activation of Rnd3 protects against cardiac remodeling in diabetic cardiomyopathy via suppression of Notch and TGF-ß signaling.

Rationale: Extracellular matrix (ECM) remodeling, a key pathological feature in diabetic cardiomyopathy (DCM), is triggered by oxidative stress, inflammation, and various metabolic disorders in the heart. Cardiac fibroblasts (CFs) are the primary source of ECM proteins and the ultimate effector cells in ECM remodeling. CFs are turned on and differentiated into myofibroblasts in response to profibrotic signaling. Rnd3 is a small Rho-GTPase involved in the regulation of cell-cycle distribution, cell migration, and cell morphogenesis. Emerging evidence suggests a link between Rnd3 expression and onset of cardiovascular diseases. However, the role of Rnd3 in DCM remains unknown. Methods: Flow cytometry was employed to separate different types of cardiac cells. Type 2 diabetes mellitus was established in Rnd3 fibroblast-specific knockout and transgenic mice. RNA sequencing and chromatin immunoprecipitation assay were used to discern signaling pathways involved. Results: Rnd3 expression was reduced in cardiac tissues of diabetic mice, with CFs being the primary cell type. Fibroblast-specific upregulation of Rnd3 in vivo was protective against DCM, whereas Rnd3 downregulation in fibroblasts accentuated cardiac oxidative stress, fibrosis, ventricular remodeling, and dysfunction. Moreover, in vitro Rnd3 overexpression significantly attenuated reactive oxygen species production, CF migration and proliferation under high levels of glucose (35 mmol/L) and palmitic acid (500 µmol/L) challenge. Furthermore, RNA sequencing indicated that Notch and TGF-ß signaling were significantly suppressed upon Rnd3 overexpression. Mechanistically, Rnd3 regulated Notch and TGF-ß signaling by interacting with NICD and ROCK1, respectively. Specifically, glucotoxicity and lipotoxicity control Rnd3 expression by regulating the binding of Nr1H2 and Rnd3 promoter. Conclusions: Our findings provide compelling evidence in that fibroblast-specific activation of Rnd3 protects against cardiac remodeling in DCM, indicating promises of targeting Rnd3 in the treatment of DCM.

In Situ Growth of High-Quality CsPbBr3 Quantum Dots with Unusual Morphology inside a Transparent Glass with a Heterogeneous Crystallization Environment for Wide Gamut Displays.

All-inorganic CsPbBr3 perovskite quantum dots (QDs) are considered to be one of the most promising green candidates for the new-generation backlight displays. The pending barriers to their applications, however, lie in their mismatching of the target window of green light, scalable production, susceptibility to the leaching of lead ions, and instability in harsh environments (such as moisture, light, and heat). Herein, high-quality CsPbBr3 QDs with globoid shapes and cuboid shapes were in situ crystallized/grown inside a well-designed glass to produce nanocomposites with peak emission at 526 nm, which not only exhibited photoluminescence quantum yields of 53 and 86% upon 455 and 365 nm excitation, respectively, but also have been imparted of high stability when they were submerged in water and exposed to heat and light. These characteristics, along with their lead self-sequestration capability and easy-to-scale preparation, can enable breakthrough applications for CsPbBr3 QDs in the field of wide color gamut backlit display. A high-performance backlight white LEDs was fabricated using the CsPbBr3 QDs@glass powder and K2SiF6:Mn4+ red phosphor, which shows a color gamut of ∼126% of the NTSC or 94% of the Rec. 2020 standards.

Changes and significance of serum monocyte chemoattractant protein-1 and Lp-PLA2 in patients with hypertension and coronary heart disease.

OBJECTIVE: To explore the combined application value of serum monocyte chemoattractant protein-1 and lipoprotein-associated phospholipase A2 in the diagnosis of hypertension and coronary heart disease. METHODS: The cross-sectional case-control study was conducted at Baoji Hospital of Traditional Chinese medicine, Shaanxi, China, from April 2018 to May 2020, and comprised patients with suspected hypertension and coronary heart disease. Patients with both hypertension and coronary heart disease formed Group A, and those with simple hypertension formed Group B. Healthy individuals formed the control Group C. Receiver operating characteristic curve was used to evaluate the value of serum monocyte chemoattractant protein-1 combined with lipoprotein-associated phospholipase A2 in the diagnosis of hypertension complicated with coronary heart disease. Data was analysed using SPSS 25. RESULTS: Of the 306 subjects, there were 122(40%) in Group A; 68(55.7%) males and 54(44.3%) females with mean age 68.77±5.76 years. There were 92(30%) cases in Group B; 51(55.4%) males and 41(44.6%) females with mean age 68.80±5.28 years. Group C had 92(30%) cases; 50(54.3%) males and 42(45.7%) females with mean age 67.85±5.29 years. Serum monocyte chemoattractant protein-1 and lipoprotein-associated phospholipase A2 levels were higher in Group A than the other two groups (p<0.001), and the levels in patients with carotid plaque total score <2 were lower than those with carotid plaque total score >2 (p<0.001). Area under receiver operating characteristic curve of the combination of the serum markers was 0.883 (95% confidence interval: 0.837-0.929, p<0.001), which was greater than that of two serum markers alone (p<0.05). CONCLUSIONS: Monocyte chemoattractant protein-1 and lipoprotein-associated phospholipase A2 may be involved in pathogenesis of elevated blood pressure and coronary artery disease. Combined detection of the two serum markers can provide a certain basis for the diagnosis and treatment of hypertension and coronary heart disease.

TGF-ß1-containing exosomes from cardiac microvascular endothelial cells mediate cardiac fibroblast activation under high glucose conditions.

Cardiac fibroblast (CF)-mediated extracellular matrix (ECM) remodeling is the key pathological basis for the occurrence and development of diabetic cardiomyopathy (DCM); its specific regulatory mechanisms have been widely studied but remain unclear. Exosomes are a type of stable signal transmission medium, and exosome-mediated cell-cell interactions play an important role in DCM. Endothelial cells form an important barrier between circulation and cardiomyocytes, in addition to being an important endocrine organ of the heart and an initial target for hyperglycemia, a key aspect in the development of DCM. We previously showed that exosomes derived from cardiac microvascular endothelial cells (CMECs) under high glucose conditions can be taken up by cardiomyocytes and regulate autophagy, apoptosis, and glucose metabolism. Consequently, in the present study, we focused on how exosomes mediate the interaction between CMECs and CFs. Surprisingly, exosomes derived from CMECs under high glucose were rich in TGF-ß1 mRNA, which significantly promoted the activation of CFs. Additionally, exosomes derived from CMECs under high glucose conditions aggravated perivascular and interstitial fibrosis in mice treated with streptozotocin. Herein, we demonstrated for the first time the capacity of exosomes, released by CMECs under high glucose, to mediate fibroblast activation through TGF-ß1 mRNA, which may be potentially beneficial in the development of exosome-targeted therapies to control DCM.

Sirt6-Mediated Endothelial-to-Mesenchymal Transition Contributes Toward Diabetic Cardiomyopathy via the Notch1 Signaling Pathway.

BACKGROUND: Endothelial-to-mesenchymal transition (EndMT) is an important source of myofibroblasts that directly affects cardiac function in diabetic cardiomyopathy (DCM) via an unknown underlying mechanism. Sirt6 is a member of the Sirtuin family of NAD(+)-dependent enzymes that plays an important role in glucose and fatty acid metabolism. In this study, we investigated whether Sirt6 participates in EndMT during the development of T2DM and the possible underlying regulatory mechanisms. METHODS: Endothelium-specific Sirt6 knockout (Sirt6-KOEC) mice (C57BL/6 genetic background) were generated using the classic Cre/loxp gene recombination system. T2DM was induced in eight-week-old male mice by feeding with a high-fat diet for three weeks followed by i.p. injection with 30 mg/kg of streptozotocin. The weight, lipids profiles, insulin, food intake and water intake of experimental animals were measured on a weekly basis. Cardiac microvascular endothelial cells (CMECs) were obtained from adult male mice; the isolated cells were cultured with high glucose (HG; 33 mmol/L) and palmitic acid (PA; 500 µmol/L) in DMEM for 24 h, or with normal glucose (NG; 5 mmol/L) as the control. RESULTS: Sirt6 expression is significantly downregulated in CMECs treated with HG+PA. Additionally, Sirt6-KOEC was found to worsen DCM, as indicated by aggravated perivascular fibrosis, cardiomyocyte hypertrophy, and decreased cardiac function. In vitro, Sirt6 knockdown exacerbated the proliferation, and migration of CMECs exposed to HG+PA. Mechanistically, Sirt6 knockdown significantly enhanced Notch1 activation in CMECs treated with HG+PA, whereas Notch1 adenoviral interference significantly blunted the effects of Sirt6 knockdown on CMECs. CONCLUSION: This study is the first to demonstrate that Sirt6 participates in EndMT via the Notch1 signaling pathway in CMECs stimulated with HG+PA. Therefore, the findings of this study suggest that Sirt6 could provide a potential treatment strategy for DCM.

Absence of the long noncoding RNA H19 results in aberrant ovarian STAR and progesterone production.

The steroidogenic acute regulatory protein (STAR) governs the rate-limiting step in steroidogenesis, and its expression varies depending on the needs of the specific tissue. It is well known that tight control of steroid production is essential for multiple processes involved in reproduction. We recently showed that Star is regulated at the posttranscriptional level in vitro by H19 and let-7. Here we demonstrate that this novel regulatory mechanism is functional in vivo, regulated by cAMP, and that loss of H19 not only disrupts ovarian STAR but also results in altered progesterone production in an H19KO mouse model. This work further strengthens the possibility that noncoding-RNA-mediated regulation of STAR may play an important role in the regulation of steroid hormone production, and contributes further to our understanding of the many ways in which this important gene is regulated.

Mst1 inhibits Sirt3 expression and contributes to diabetic cardiomyopathy through inhibiting Parkin-dependent mitophagy.

Mitochondrial dysfunction contributes to heart failure induced mortality in approximately 80% of diabetic patients. Mitophagy degrades defective mitochondria and maintains a healthy mitochondrial population, which is essential for cardiomyocyte survival in diabetic stress. Herein, we determined whether Mst1 regulated mitophagy and investigated the downstream signaling pathway in the development of diabetic cardiomyopathy (DCM). Mst1 deficiency promoted elimination of dysfunctional mitochondria in diabetic cardiomyopathy without affecting mitochondrial biogenesis. Enhanced mitophagy was observed in Mst1 interfering cardiomyocytes subjected to high glucose treatment using 3-Methyladenine and Chloroquine. Consistent with these results, in vivo and in vitro loss of function experiments indicated that Mst1 participated in the development of DCM by inhibiting Parkin-dependent mitophagy. Mst1 deficiency alleviated the detrimental phenotype of DCM. Interestingly, the protective effects of Mst1 knockout on DCM were compromised in diabetic Parkin-/- mice. Mechanistically, Mst1 knockdown significantly enhanced Parkin expression and translocation to the mitochondria, as evidenced by immunofluorescence study and Western blot analysis. Furthermore, Sirt3 deletion abolished the detrimental effects of Mst1 on DCM. Collectively, Mst1 inhibits Sirt3 expression thus participates in the development of DCM by inhibiting cardiomyocyte mitophagy. The mechanism is associated with Parkin inhibition.

Correlation between lung cancer and the HHIP polymorphisms of chronic obstructive pulmonary disease (COPD) in the Chinese Han population.

To further investigate the relationship between lung cancer and hedgehog interacting protein (HHIP) polymorphisms of chronic obstructive pulmonary disease (COPD) patients, we conducted a case-control study in a Chinese Han population. Six HHIP SNPs with minor allele frequencies >5% (rs1489758, rs1489759, rs10519717, rs13131837, rs1492820, and rs7689420) were analyzed in 1,017 COPD patients (767 males and 246 females) and 430 non-COPD patients. Using logistic regression analysis, we found that rs7689420 was significantly associated with lung cancer in COPD patients in the Chinese Han population (P < 0.001). The recessive allele of rs7689420 was associated with the occurrence of lung cancer in all COPD patients (odds ratios [OR] of 0.609 and 0.424 for the CT and TT genotypes, respectively) as well as in serious COPD patients (OR of 0.403 and 0.305 for CT and TT, respectively). Additionally, rs1489759 and rs3131837 were associated with lung cancer in various genetic models. rs1489758, rs1489759, and rs10519717 were also associated with lung cancer in serious COPD patients. However, none of the SNPs were significantly associated with lung cancer in mild COPD patients or healthy subjects. Therefore, the HHIP SNPs of COPD patients likely play a role in lung cancer pathology in the Chinese Han population.

A novel, noncoding-RNA-mediated, post-transcriptional mechanism of anti-Mullerian hormone regulation by the H19/let-7 axis.

In reproductive age women, the pool of primordial follicles is continuously depleted through the process of cyclic recruitment. Anti-Mullerian hormone (AMH) both inhibits the initial recruitment of primordial follicles into the growing pool and modulates the sensitivity of growing follicles to follicle stimulating hormone. Thus, AMH may be an important modulator of female infertility and ovarian reserve; however, the mechanisms regulating AMH remain unclear.To evaluate AMH levels in the absence of H19 lncRNA, H19 knockout (H19KO) mice were evaluated for analysis of ovarian AMH gene expression, protein production, and reproductive function, including assessment of follicle numbers and litter size analysis. To further investigate regulation of AMH by the H19/let-7 axis, let-7 binding sites on AMH were predicted, and in vitro studies of the effect of H19 knockdown/overexpression with let-7 rescue were performed. Lastly, response to superovulation was assessed via oocyte counts and estradiol measurements.The H19KO mouse demonstrates subfertility and accelerated follicular recruitment with increased spontaneous development of secondary, preantral, and antral follicles. Ovaries of H19KO mice have decreased AMH mRNA and protein, and AMH mRNA has a functional let-7 binding site, suggesting a plausible ncRNA-mediated mechanism for AMH regulation by H19/let-7. Lastly, in the absence of H19, superovulation results in higher estradiol and more oocytes, suggesting that H19 functions to limit the number of follicles that mature, produce estradiol, and ovulate. Thus, AMH's inhibitory actions are regulated at least in part by H19, likely via let-7, marking this ncRNA pair as important regulators of the establishment and maintenance of the follicular pool.

Melatonin activates Parkin translocation and rescues the impaired mitophagy activity of diabetic cardiomyopathy through Mst1 inhibition.

Mitophagy eliminates dysfunctional mitochondria and thus plays a cardinal role in diabetic cardiomyopathy (DCM). We observed the favourable effects of melatonin on cardiomyocyte mitophagy in mice with DCM and elucidated their underlying mechanisms. Electron microscopy and flow cytometric analysis revealed that melatonin reduced the number of impaired mitochondria in the diabetic heart. Other than decreasing mitochondrial biogenesis, melatonin increased the clearance of dysfunctional mitochondria in mice with DCM. Melatonin increased LC3 II expression as well as the colocalization of mitochondria and lysosomes in HG-treated cardiomyocytes and the number of typical autophagosomes engulfing mitochondria in the DCM heart. These results indicated that melatonin promoted mitophagy. When probing the mechanism, increased Parkin translocation to the mitochondria may be responsible for the up-regulated mitophagy exerted by melatonin. Parkin knockout counteracted the beneficial effects of melatonin on the cardiac mitochondrial morphology and bioenergetic disorders, thus abolishing the substantial effects of melatonin on cardiac remodelling with DCM. Furthermore, melatonin inhibited Mammalian sterile 20-like kinase 1 (Mst1) phosphorylation, thus enhancing Parkin-mediated mitophagy, which contributed to mitochondrial quality control. In summary, this study confirms that melatonin rescues the impaired mitophagy activity of DCM. The underlying mechanism may be attributed to activation of Parkin translocation via inhibition of Mst1.

Nicorandil alleviates myocardial injury and post-infarction cardiac remodeling by inhibiting Mst1.

BACKGROUND: Cardiomyocyte autophagy and apoptosis are crucial events underlying the development of cardiac abnormalities and dysfunction after myocardial infarction (MI). A better understanding of the cell signaling pathways involved in cardiac remodeling may support the development of new therapeutic strategies for the treatment of heart failure (HF) after MI. METHODS: A cardiac MI injury model was constructed by ligating the left anterior descending (LAD) coronary artery. Neonatal cardiomyocytes were isolated and cultured to investigate the mechanisms underlying the protective effects of nicorandil on MI-induced injury. RESULTS: Nicorandil reduced cardiac enzyme release, mitigated left ventricular enlargement and cardiac dysfunction after MI, as evaluated by echocardiography and hemodynamic measurements. According to the results of the western blot analysis and immunofluorescence staining, nicorandil enhanced autophagic flux and reduced apoptosis in cardiomyocytes subjected to hypoxic injury. Interestingly, nicorandil increased Mst1 and p-Mst1 levels in cardiomyocytes subjected to MI injury. Mst1 knockout abolished the protective effects of nicorandil on cardiac remodeling and dysfunction after MI. Mst1 knockout also abolished the beneficial effects of nicorandil on cardiac enzyme release and cardiomyocyte autophagy and apoptosis. CONCLUSIONS: Nicorandil alleviates post-MI cardiac dysfunction and remodeling. The mechanisms were associated with enhancing autophagy and inhibiting apoptosis through Mst1 inhibition.

Polydatin ameliorates diabetic cardiomyopathy via Sirt3 activation.

BACKGROUND: Diabetic cardiomyopathy is identified as cardiac ventricular dysfunction induced by an insulin shortage in diabetic patients. Our previous studies have shown that Polydatin (PD) alleviates cardiac dysfunction after myocardial infarction (MI) injury. Nevertheless, the mechanism by which PD regulates diabetic cardiomyopathy has not been reported. METHODS: In this study, we demonstrated the effects and described the mechanisms of PD in diabetic cardiomyopathy in both adult mouse hearts and neonatal mouse cardiomyocytes. We injected streptozotocin (STZ) to induce the DM model in wild-type (WT) and Sirt3 knockout (Sirt3-/-) mice. Mitochondrial bioenergetics in diabetic mice were detected by measuring citrate synthase activity and ATP content. The extent of autophagy regulation by PD was investigated by detecting the levels of Beclin 1, Atg5, LC3 and p62. RESULTS: Compared to the WT mouse hearts, hearts from the diabetic mice exhibited better cardiac function and a higher level of autophagy. Moreover, mitochondrial function in the diabetic mouse hearts was improved after PD treatment. However, PD treatment had no effect on the Sirt3 knockout diabetic mouse hearts. Additionally, PD increased autophagy flux in the cardiomyocytes that were cultured in high-glucose medium for 48 h. In addition, PD had no effects on the cardiomyocytes under high-glucose conditions when we down-regulated Sirt3. CONCLUSIONS: Altogether, PD attenuated cardiac dysfunction, increased autophagy flux and improved mitochondrial bioenergetics by up-regulating Sirt3 in the diabetic mice.

The immunosuppressive characteristics of FB1 by inhibition of maturation and function of BMDCs.

Fumonisin B1 (FB1) is one kind of mycotoxins that has the neurotoxicity, carcinogenicity, hepatotoxicity and immunotoxicity produced by the fungus Fusarium verticillioides, which commonly infects corn and other crops and is harmful to animal and human health upon consumption of FB1-contaminated feed or food. However, the mechanism of immunotoxicity, especially the immunosuppression induced by FB1 is still unclear. The most pivotal cells in the induction of immune responses are dendritic cells (DCs). In this study, we used murine bone marrow-derived dendritic cells (BMDCs) as a model system to elucidate the effect of FB1 on the function of BMDCs through biological methods. We found that FB1 reversed the morphological changes and enhanced the endocytosis of FITC-dextran in LPS-treated BMDCs. At the same time, FB1 decreased the LPS-induced expressions of MHC II, C[1]D80 and CD86 molecules in BMDCs (p<0.05), as well as the T-cell stimulatory capacity of BMDCs (p<0.01). Moreover, the secretions of IL-6, IL-10 and IL-12, but not TNF-α induced by LPS exposure were suppressed by FB1 in a dose dependent (p<0.01). It was considered that the immunosuppressive effects of FB1 were mainly caused by changing the morphology and interfering with the process of antigen uptake, processing and presentation. The results highlighted that FB1 had the capacity to modulate the immune responses of BMDCs.

N-Myc Downstream-Regulated Gene 2 (Ndrg2) Is Involved in Ischemia-Hypoxia-Induced Astrocyte Apoptosis: a Novel Target for Stroke Therapy.

Nearly all clinical trials that have attempted to develop effective strategies against ischemic stroke have failed, excluding those for thrombolysis, and most of these trials focused only on preventing neuronal loss. However, astrocytes have gradually become a target for neuroprotection in stroke. In previous studies, we showed that the newly identified molecular N-myc downstream-regulated gene 2 (Ndrg2) is specifically expressed in astrocytes in the brain and involved in some neurodegenerative diseases. However, the role of NDRG2 in ischemic stroke remained unclear. In this study, we investigated the role of NDRG2 in middle cerebral artery occlusion (MCAO)-induced focal cerebral ischemia and in oxygen-glucose deprivation (OGD)-induced cellular apoptosis in the M1800 astrocyte cell line. NDRG2 mRNA and protein expression began to increase at 6 and 2 h after reperfusion and peaked at 24 h in the ischemic penumbra and in M1800 cells, as detected by RT-PCR and Western blotting. Double immunofluorescence staining showed that the number of apoptotic cells increased as the NDRG2-positive signal increased and that the NDRG2 signal was sometimes co-localized with TUNEL-positive cells and translocated from the cytoplasm to the nucleus in both the ischemic penumbra and the M1800 cells. Using a lentivirus, we successfully constructed two stable astrocytic cell lines in which NDRG2 expression was significantly up- or down-regulated. NDRG2 silencing had a proliferative effect and reduced the percentage of apoptotic cells, reactive oxygen species (ROS) production, and cleaved Caspase-3 protein expression following OGD, whereas NDRG2 over-expression had the opposite effects. In conclusion, NDRG2 is involved in astrocyte apoptosis following ischemic-hypoxic injury, and inhibiting NDRG2 expression significantly reduces ROS production and astrocyte apoptosis. These findings provide insight into the role of NDRG2 in ischemic-hypoxic injury and provide potential targets for future clinical therapies for stroke.

Melatonin alleviates postinfarction cardiac remodeling and dysfunction by inhibiting Mst1.

Melatonin reportedly protects against several cardiovascular diseases including ischemia/reperfusion (I/R), atherosclerosis, and hypertension. The present study investigated the effects and mechanisms of melatonin on cardiomyocyte autophagy, apoptosis, and mitochondrial injury in the context of myocardial infarction (MI). We demonstrated that melatonin significantly alleviated cardiac dysfunction after MI. Four weeks after MI, echocardiography and Masson staining indicated that melatonin notably mitigated adverse left ventricle remodeling. The mechanism may be associated with increased autophagy, reduced apoptosis, and alleviated mitochondrial dysfunction. Furthermore, melatonin significantly inhibited Mst1 phosphorylation while promoting Sirt1 expression after MI, which indicates that Mst1/Sirt1 signaling may serve as the downstream target of melatonin. We thus constructed a MI model using Mst1 transgenic (Mst1 Tg) and Mst1 knockout (Mst1-/- ) mice. The absence of Mst1 abolished the favorable effects of melatonin on cardiac injury after MI. Consistently, melatonin administration did not further increase autophagy, decrease apoptosis, or alleviate mitochondrial integrity and biogenesis in Mst1 knockout mice subjected to MI injury. These results suggest that melatonin alleviates postinfarction cardiac remodeling and dysfunction by upregulating autophagy, decreasing apoptosis, and modulating mitochondrial integrity and biogenesis. The attributed mechanism involved, at least in part, Mst1/Sirt1 signaling.

The Steroidogenic Acute Regulatory Protein (StAR) Is Regulated by the H19/let-7 Axis.

The steroidogenic acute regulatory protein (StAR) governs the rate-limiting step in steroidogenesis, and its expression varies depending on the needs of the specific tissue. Tight control of steroid production is essential for multiple processes involved in reproduction, including follicular development, ovulation, and endometrial synchronization. Recently, there has been a growing interest in the role of noncoding RNAs in the regulation of reproduction. Here we demonstrate that StAR is a novel target of the microRNA let-7, which itself is regulated by the long noncoding RNA (lncRNA) H19. Using human and murine cell lines, we show that overexpression of H19 stimulates StAR expression by antagonizing let-7, which inhibits StAR at the post-transcriptional level. Our results uncover a novel mechanism underlying the regulation of StAR expression and represent the first example of lncRNA-mediated control of the rate-limiting step of steroidogenesis. This work thus adds to the body of literature describing the multiple roles in oncogenesis, cellular growth, glucose metabolism, and now regulation of steroidogenesis, of this complex lncRNA.

DDR1 may play a key role in destruction of the blood-brain barrier after cerebral ischemia-reperfusion.

Discoidin domain receptor 1 (DDR1) has been shown to mediate matrix metalloproteinase-9 (MMP-9) secretions and degrade all extracellular matrix compounds in mammalian tumor cells. We hypothesized that DDR1 expression will be elevated and the blood-brain barrier (BBB) will be damaged after focal cerebral ischemia in rats. Inhibiting DDR1 expression can alleviate BBB disruption and cerebral ischemic damage via down-regulation of MMP-9 expression and activity. To test our hypothesis, we injected specific DDR1 siRNA into ipsilateral ischemic lateral ventricles in a focal ischemic model. Our results showed that phospho-DDR1 expression increased after ischemia/reperfusion (I/R) injury (p < 0.01). Inactivation of DDR1 by specific siRNA caused a decrease in phospho-DDR1 and MMP-9 expression in the ischemic cortex, reduced stroke-induced infarct volume, and alleviated BBB disruption in rat brain following I/R injury (p < 0.01). Our results suggested that DDR1-siRNA attenuates phospho-DDR1 and MMP-9 upregulation, which was followed by a reduction in infarction and BBB disruption in the ischemic brain after I/R injury. DDR1 may represent a molecular target for the prevention of BBB disruption after cerebral I/R injury.