ZNF787 and HDAC1 Mediate Blood-Brain Barrier Permeability in an In Vitro Model of Alzheimer's Disease Microenvironment.

The permeability of the blood-brain barrier (BBB) is increased in Alzheimer's disease (AD). This plays a key role in the instigation and maintenance of chronic inflammation during AD. Experiments using AD models showed that the increased permeability of the BBB was mainly caused by the decreased expression of tight junction-related proteins occludin and claudin-5. In this study, we found that ZNF787 and HDAC1 were upregulated in ß-amyloid (Aß)1-42-incubated endothelial cells, resulting in increased BBB permeability. Conversely, the silencing of ZNF787 and HDAC1 by RNAi led to reduced BBB permeability. The silencing of ZNF787 and HDAC1 enhanced the expression of occludin and claudin-5. Mechanistically, ZNF787 binds to promoter regions for occludin and claudin-5 and functions as a transcriptional regulator. Furthermore, we demonstrate that ZNF787 interacts with HDAC1, and this resulted in the downregulation of the expression of genes encoding tight junction-related proteins to increase in BBB permeability. Taken together, our study identifies critical roles for the interaction between ZNF787 and HDAC1 in regulating BBB permeability and the pathogenesis of AD.

Astragaloside IV mitigates hypoxia-induced cardiac hypertrophy through calpain-1-mediated mTOR activation.

BACKGROUND: Astragaloside IV (AsIV), a key functioning element of Astragalus membranaceus, has been recognized for its potential cardiovascular protective properties. However, there is a need to elucidate the impacts of AsIV on myocardial hypertrophy under hypoxia conditions and its root mechanisms. PURPOSE: This study scrutinized the influence of AsIV on cardiac injury under hypoxia, with particular emphasis on the role of calpain-1 (CAPN1) in mediating mTOR pathways. METHODS: Hypoxia-triggered cardiac hypertrophy was examined in vivo with CAPN1 knockout and wild-type C57BL/6 mice and in vitro with H9C2 cells. The impacts of AsIV, 3-methyladenine, and CAPN1 inhibition on hypertrophy, autophagy, apoptosis, [Ca2+]i, and CAPN1 and mTOR levels in cardiac tissues and H9C2 cells were investigated. RESULTS: Both AsIV treatment and CAPN1 knockout mitigated hypoxia-induced cardiac hypertrophy, autophagy, and apoptosis in mice and H9C2 cells. Moreover, AsIV, 3-methyladenine, and CAPN1 inhibition augmented p-mTOR level but reduced [Ca2+]i and CAPN1 level. Additionally, lentivirus-mediated CAPN1 overexpression in H9C2 cells exacerbated myocardial hypertrophy, apoptosis, and p-mTOR inhibition under hypoxia. Specifically, AsIV treatment reversed the impacts of increased CAPN1 expression on cardiac injury and the inhibition of p-mTOR. CONCLUSION: These findings suggest that AsIV may alleviate cardiac hypertrophy under hypoxia by attenuating apoptosis and autophagy through CAPN1-mediated mTOR activation.

UBIAD1 expression is associated with cardiac hypertrophy in spontaneously hypertensive rats.

The present study investigated the potential role of UbiA prenyltransferase domain-containing 1 (UBIAD1) in the pathogenesis of hypertensive cardiac hypertrophy. Spontaneously hypertensive rats (SHRs) and Wistar­Kyoto (WKY) rats at 8, 16 and 28 weeks of age were used. Blood pressure was measured using a non­invasive tail cut­off system. Cardiac functional index was assessed by arterial catheterization. Myocardial structure and cell apoptosis were evaluated by hematoxylin and eosin staining, and terminal deoxynucleotidyl­transferase­mediated dUTP nick end labeling assays, respectively. Myocardial expression of UBIAD1, coenzyme Q10 (CoQ10), endothelial nitric oxide synthase (eNOS) and atrial natriuretic peptide were evaluated by immunohistochemistry, western blotting and reverse transcription­quantitative polymerase chain reaction. Circulating and myocardial expression of nitric oxide (NO) were measured using the Griess method. SHRs exhibited increased blood pressure and cardiomyocyte apoptosis, as well as cardiac hypertrophy, compared with age­matched WKY rats. Myocardial expression of UBIAD1 was significantly decreased in SHRs in an age­dependent manner. Similarly, myocardial CoQ10 and eNOS expression were significantly reduced in SHR compared to age­matched WKY rats, and these expression levels additionally decreased further with aging. Serum and myocardial NO expression was additionally decreased in SHRs. Decreased UBIAD1 expression in SHR hearts was associated with decreased levels of CoQ10, eNOS and NO. Given the well­established role of UBIAD1 in the regulation of NO signaling, reduced expression of UBIAD1 in SHR hearts potentially contributed to the pathogenesis of hypertensive cardiac hypertrophy. Therefore, UBIAD1 may represent a potential therapeutic target for clinical treatment of hypertensive cardiac hypertrophy.

Depletion of ubiA prenyltransferase domain containing 1 expression promotes angiotensin II­induced hypertrophic response in AC16 human myocardial cells via modulating the expression levels of coenzyme Q10 and endothelial nitric oxide synthase.

UbiA prenyltransferase domain containing 1 (UBIAD1) is closely associated with cardiovascular diseases. However, at the cellular level, little is known about how UBIAD1 is expressed and functions in cardiomyocyte hypertrophy. The aim of the present study was to investigate the expression and role of UBIAD1 in angiotensin II (Ang II)­induced hypertrophy in AC16 cardiomyoblast cells. The loss­of­function approach was used to knock down UBIAD1 in vehicle­ and Ang II­stimulated AC16 cells. The levels of atrial natriuretic factor (ANF) and caspase-3 were measured and compared between vehicle­ and Ang II­treated AC16 cells pretreated with control siRNA or siRNA against UBIAD1. In addition, the levels of coenzyme Q10 (CoQ10) and endothelial nitric oxide synthase (eNOS) were evaluated and compared between these groups. Ang II induced hypertrophy and apoptosis in AC16 cells, accompanied by increased expression of ANF and caspase-3, and decreased expression of UBIAD1. These effects were potentiated by UBIAD1 knockdown. In addition, Ang II treatment suppressed the expression of CoQ10 and eNOS, as well as the production of NO, and these inhibitory effects were also enhanced by UBIAD1 knockdown. Thus, silencing of UBIAD1 expression promotes a myocardial hypertrophic response to Ang II stimulation, in part, by suppressing the expression of CoQ10 and eNOS.

A polysaccharide (PNPA) from Pleurotus nebrodensis ameliorates hepatic ischemic/reperfusion (I/R) injury in rats.

The effects of a polysaccharide (PNPA) from the fruiting bodies of Pleurotus nebrodensis on hepatic ischemia/reperfusion (I/R) injury in rats were explored. Severe liver injury was shown in rats following I/R with high content of serum AST and ALT, as evidenced by histological examination, whereas less damage was noted after PNPA treatment compared to rats in the I/R group. Also, pre-treatment with PNPA (400mg/kg) could reduce the level of MDA in liver tissue and increase the activity of ROS scavengers (T-AOC, SOD, CAT, GSH-PX), Nitric oxide synthase (T-NOS and iNOS), and GSH. Moreover, PNPA could still reduce the production of I/R-induced inflammatory cytokines (IL-1ß, IL-6, TNF-α and NF-κB) in liver, along with MPO. I/R-induced high level of pro-apoptotic indicators (cytochrome c, Bax, and caspase 3) and low level of anti-apoptotic indicators Bcl-2 were reversed after PNPA pretreatment. Therefore, PNPA might be a promising candidate for preventing hepatic I/R injury.

A polysaccharide (PNPA) from Pleurotus nebrodensis offers cardiac protection against ischemia-reperfusion injury in rats.

In this study, we isolated a polysaccharide (PNPA), with a molecular weight of 105kDa, from the fruiting bodies of Pleurotus nebrodensis. It had a backbone consisting of 1,3-linked-d-glucpyranosyl and 1,3,6-linked-d-galactopyranosyl residues, which was terminated with 1-linked-d-mannopyranosyl terminal at O-3 position of 1,3,6-linked-d-galactopyranosyl unit along the main chain in the ratio of 4:1:1. We further examined the effect of PNPA on myocardial ischemia-reperfusion (I/R) injury in rats and elucidated the underlying mechanism. Pretreatment with PNPA (100 and 400mg/kg) for 30 days significantly attenuated myocardial infarct size as compared to I/R model group. A decrease in superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels, as well as an increased malondialdehyde (MDA) content were observed in both myocardial serum and tissues of control I/R group, whereas pretreatment with PNPA markedly restored these change, and also relieved myocardial cell apoptosis. These results suggested that PNPA achieved protective effect on myocardial I/R injury in part through improving endogenous antioxidants and suppressing myocardial cell apoptosis.