[Effects of NLRP3/Caspase-1 pathway on Banxia Houpu decoction in the intervention of chronic intermittent hypoxia in mice with renal inflammatory injury].

Objective: To investigate the effects of Banxia Houpo decoction on the renal NLRP3/Caspase-1/IL-1ß signaling pathway in chronic intermittent hypoxia mice. Methods: C57BL/6 mice were randomly divided into 3 groups, normal control group (Control), chronic intermittent hypoxia group (CIH), and Banxia Houpo decoction treatment group (BHD), with 10 mice in each group. Mice in the CIH group and BHD group were placed in a hypoxic chamber. The oxygen volume fraction in the cabin was decreased from 21% to 9% in 90 s, and then oxygen was filled in 90 s to gradually increase the oxygen volume fraction in the cabin to 21%, while the mice in the control group were placed in the cabin and filled with normal air, processing 8 hours per day for 21 days. The mice in BHD group were treated with Banxia Houpu decoction by gavage before entering the cabin every day, and the control group and CIH group were given an equal volume of normal saline. After modeling, the changes of renal function indexes in each group were detected; HE and Masson staining were used to observe the pathological conditions of the kidney; Western blot and immunohistochemical staining were used to detect the protein expression levels of the nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3), aspartate-specific cysteine protein 1(Caspase-1) and interleukine-1beta(IL-1ß). Results: Compared with control group, the contents of serum renal functional indexes UA, BUN and SCr in CIH group were increased significantly (P<0.01), and after BHD treatment, they all were decreased significantly compared with CIH group (P<0.01). Compared with control group, the results of HE staining showed that in the CIH group, glomerular endothelial cells were degenerated and necrotic, and vacuoles of different sizes appeared in renal tubular epithelial cells, and a small amount of renal tubular epithelial cells fell off and died. The pathological condition of the BHD group was improved compared with CIH group, the glomerular morphology gradually returned to normal, and a small amount of renal tubular epithelial cells fell off and died. Compared with control group, Masson staining results showed that there was obvious fibrosis around the glomeruli in the CIH group, the fibrosis was significantly reduced in the BHD group. The expression levels of NLRP3, Caspase-1, IL-1ß and IL-18 were increased significantly compared with control group (P<0.05 or P<0.01), and immunohistochemical staining showed that NLRP3 was mainly expressed in renal tubular epithelial cells and interstitial macrophages, caspase-1 and IL-1ß were mainly found in the cytoplasm of renal tubular epithelial cells. After BHD treatment, the expression levels of each protein were decreased compared with CIH group (P<0.05). Conclusion: Banxia Houpu decoction can reduce the kidney damage by inhibiting the expression of related molecules in the NLRP3/Casapse-1/IL-1ß signaling pathway.

Therapeutic Potential of Astragaloside IV Against Adriamycin-Induced Renal Damage in Rats via Ferroptosis.

Adriamycin (ADR) has been utilized to treat cancer for several decades. However, ADR-induced renal injury is one of the most common side effects accompanying ADR therapy. In the present study, we revealed that astragaloside IV (ASIV) was beneficial for renal injury caused by Adriamycin. We demonstrated that ASIV significantly ameliorated kidney injury, improved renal dysfunction, reduced oxidative stress, alleviated iron accumulation, and inhibited the induction of ferroptosis by ADR. ASIV also rescued the intracellular levels of nuclear factor-erythroid-2-related factor 2 (Nrf2) and promoted nuclear translocation of Nrf2. These protective effects of ASIV on renal injury might be attained through the ASIV-induced activation of the Pi3K/Akt signaling pathway. In vitro, the treatment of the HK-2 cells with fer-1 or deferoxamine mesylate obviously improved cell viability during Adriamycin administration. On the other hand, the protective role of ASIV can be abrogated by RSL3 to some extent. Moreover, ASIV lowered the expression of transferrin receptor 1 and divalent metal transporter 1 while enhancing the expression of ferropotin 1 and glutathione peroxidase 4 in ADR administrated cells, the effects of which were akin to those of deferoxamine mesylate. Furthermore, ASIV increased the phosphorylation of Pi3K, Akt, and the expression of Nrf2 and glutathione peroxidase 4 compared to HK-2 cells stimulated by ADR. However, Pi3K inhibitor LY294002 abrogated these activations. In conclusion, ferroptosis may involve in ADR-induced nephrotoxicity, and ASIV might protect nephrocytes against ADR-induced ferroptosis, perhaps via activations of the Pi3K/Akt and Nrf2 signaling pathways.

Liraglutide attenuates hepatic iron levels and ferroptosis in db/db mice.

Liver pathological changes are as high as 21%-78% in diabetic patients, and treatment options are lacking. Liraglutide is a glucagon-like peptide-1 (GLP-1) receptor that is widely used in the clinic and is approved to treat obesity and diabetes. However, the specific protection mechanism needs to be clarified. In the present study, db/db mice were used to simulate Type 2 diabetes mellitus (T2DM), and they were intraperitoneally injected daily with liraglutide (200 µg/kg/d) for 5 weeks. Hepatic function, pathologic changes, oxidative stress, iron levels, and ferroptosis were evaluated. First, liraglutide decreased serum AST and ALT levels, and suppressed liver fibrosis in db/db mice. Second, liraglutide inhibited the ROS production by upregulating SOD, GSH-PX, and GSH activity as well as by downregulating MDA, 4-HNE, and NOX4 expression in db/db mice. Furthermore, liraglutide attenuated iron deposition by decreasing TfR1 expression and increasing FPN1 expression. At the same time, liraglutide decreased ferroptosis by elevating the expression of SLC7A11 and the Nrf2/HO-1/GPX4 signaling pathway in the livers of db/db mice. In addition, liraglutide decreased the high level of labile iron pools (LIPs) and intracellular lipid ROS induced by high glucose in vitro. Therefore, we speculated that liraglutide played a crucial role in reducing iron accumulation, oxidative damage and ferroptosis in db/db mice.

Banxia-Houpu decoction diminishes iron toxicity damage in heart induced by chronic intermittent hypoxia.

CONTEXT: Obstructive sleep apnoea (OSA) causes chronic intermittent hypoxia (CIH), which results in mitochondrial dysfunction and generates reactive oxygen species (ROS) in the heart. Excessive free iron could accelerate oxidative damage, which may be involved in this process. Banxia-Houpu decoction (BHD) was reported to improve the apnoea hypopnoea index in OSA patients, but the specific mechanism was still unclear. OBJECTIVE: To investigate whether BHD could reduce CIH-induced heart damage by regulating iron metabolism and mitochondrial function. MATERIALS AND METHODS: C57BL/6N mice were randomly divided into control, CIH and BHD groups. Mice were exposed to CIH (21 - 5% O2, 20 times/h, 8 h/d) and administered BHD (3.51, 7.01 and 14.02 g/kg, intragastrically) for 21 d. Cardiac and mitochondrial function, iron levels, apoptosis and mitophagy were determined. RESULTS: BHD (7.01 g/kg) significantly improved cardiac dysfunction, pathological change and mitochondrial structure induced by CIH. BHD increased the Bcl-2/Bax ratio (1.4-fold) and inhibited caspase 3 cleavage in CIH mice (0.45-fold). BHD activated mitophagy by upregulating Parkin (1.94-fold) and PINK1 (1.26-fold), inhibiting the PI3K-AKT-mTOR pathway. BHD suppressed ROS generation by decreasing NOX2 (0.59-fold) and 4-HNE (0.83-fold). BHD reduced the total iron in myocardial cells (0.72-fold) and mitochondrial iron by downregulating Mfrn2 (0.81-fold) and MtFt (0.78-fold) proteins, and upregulating ABCB8 protein (1.33-fold). Rosmarinic acid, the main component of Perilla Leaf in BHD, was able to react with Fe2+ and Fe3+ in vitro. DISCUSSION AND CONCLUSIONS: These findings encourage the use of BHD to resist cardiovascular injury and provide the theoretical basis for clinical treatment in OSA patients.

Involvement of Hepcidin in Cognitive Damage Induced by Chronic Intermittent Hypoxia in Mice.

Obstructive sleep apnea (OSA) patients exhibit different degrees of cognitive impairment, which is related to the activation of reactive oxygen species (ROS) production by chronic intermittent hypoxia (CIH) and the deposition of iron in the brain. As a central regulator of iron homeostasis, whether hepcidin is involved in OSA-induced cognitive impairment has not been clarified. In order to simulate OSA, we established the mouse model by reducing the percentage of inspired O2 (FiO2) from 21% to 5%, 20 times/h for 8 h/day. We found hepcidin was rising during CIH, along with increasing iron levels and neuron loss. Then, we constructed a mouse with astrocyte-specific knockdown hepcidin gene (shHamp). During CIH exposure, the shHamp mice showed a lower level of total iron and neuronal iron in the hippocampus, via stabilizing ferroportin 1 (FPN1) and decreasing L-ferritin (FTL) levels, when compared with wild-type (WT) mice. Furthermore, the shHamp mice showed a decrease of ROS by downregulating the elevated NADPH oxidase (NOX2) and 4-hydroxynonenal (4-HNE) levels mediated by CIH. In addition, the shHamp mice presented improved cognitive deficit by improving synaptic plasticity and BDNF expression in the hippocampus when subjected to CIH. Therefore, our data revealed that highly expressed hepcidin might promote the degradation of FPN1, resulting in neuronal iron deposition, oxidative stress damage, reduced synaptic plasticity, and impaired cognitive performance during CIH exposure.

A rapid juvenile murine model of nonalcoholic steatohepatitis (NASH): Chronic intermittent hypoxia exacerbates Western diet-induced NASH.

AIMS: Many dietary NASH models require a long duration to establish (4-6 months). Chronic intermittent hypoxia (CIH), a cardinal hallmark of obstructive sleep apnea (OSA), may accelerate the progression of pediatric nonalcoholic fatty liver disease (NAFLD). However, diet-induced obese (DIO) mice exposed to CIH have not been perceived as a fast or reliable tool in NASH research. This study was designed to establish a rapid juvenile murine NASH model, and determine whether the combination of CIH and a western-style diet (hypercaloric fatty diet plus high fructose) can fully display key pathologic features of NASH. METHODS: C57BL/6 N mice (3 weeks old) fed a control diet or western diet (WD) were exposed to CIH (9% nadir of inspired oxygen levels) or room air for 6 and 12 weeks. KEY FINDINGS: The Control/CIH group mainly exhibited hyperinsulinemia and insulin resistance (IR). In contrast, mice fed a WD developed weight gain after 3 weeks, microvesicular steatosis in 6 weeks, and indices of metabolic disorders at 12 weeks. Furthermore, CIH exposure accelerated WD- induced macromicrovesicular steatosis (liver triglycerides and de novo lipogenesis), liver injury (ballooned hepatocytes and liver enzymes), lobular/portal inflammation (inflammatory cytokines and macrophage recruitment), and fibrogenesis (hydroxyproline content and TGF-ß protein). Notably, only the WD/CIH group exhibited elevated hepatic MDA content, protein levels of NOX4, α-SMA and collagen I, as well as reduced Nrf2 and HO-1 protein expression. SIGNIFICANCE: WD/CIH treatment rapidly mimics the histological characteristics of pediatric NASH with metabolic dysfunction and fibrosis, representing an appropriate experimental model for NASH research.

Huperzine A, reduces brain iron overload and alleviates cognitive deficit in mice exposed to chronic intermittent hypoxia.

Chronic intermittent hypoxia (CIH) is a consequence of obstructive sleep apnea (OSA), which increases reactive oxygen species (ROS) generation, resulting in oxidative damage and neurocognitive impairment. This study was designed to determine whether abnormal iron metabolism occurs in the brain under conditions of CIH and whether Huperzine A (HuA) could improve abnormal iron metabolism and neurological damage. The mouse model of CIH was established by reducing the percentage of inspired O2 (FiO2) from 21% to 9% 20 times/h for 8 h/day, and Huperzine A (HuA, 0.1 mg/kg, i.p.) was administered during CIH exposure for 21 days. HuA significantly improved cognitive impairment and neuronal damage in the hippocampus of CIH mice via increasing the ratio of Bcl-2/Bax and inhibiting caspase-3 cleavage. HuA considerably decreased ROS levels by downregulating the high levels of NADPH oxidase (NOX 2, NOX 4) mediated by CIH. There was an overload of iron, which was characterized by high levels of ferritin (FTL and FTH) and transferrin receptor 1 (TfR1) and low levels of ferroportin 1 (FPN1) in the hippocampus of CIH mice. Decreased levels of TfR1 and FTL proteins observed in HuA treated CIH group, could reduce iron overload in hippocampus. HuA increased PSD 95 protein expression, CREB activation and BDNF protein expression to protect against synaptic plasticity impairment induced by CIH. HuA acts as an effective iron chelator to attenuate apoptosis, oxidative stress and synaptic plasticity mediated by CIH.

Resveratrol protects against CIH-induced myocardial injury by targeting Nrf2 and blocking NLRP3 inflammasome activation.

The prominent feature of obstructive sleep apnea (OSA) is chronic intermittent hypoxia (CIH). Given the strong antioxidant ability of resveratrol against oxidative stress, we evaluated the potential protective effects of resveratrol on myocardial injury induced by CIH. Twenty-four rats were divided into normal control group, CIH group, CIH plus resveratrol treated (CIH + Res) group, and resveratrol treated control (Res) group. We proved that CIH impaired cardiac structure and function with an increase in oxidative stress, endoplasmic reticulum (ER) stress and NOD-like receptors (NLRP3) inflammasome induction in heart, which was attenuated after resveratrol administration. NLRP3 inflammasome blockade by resveratrol appeared to be mediated by activating AMP-activated Protein Kinase (AMPK), which could restrain mTOR/TTP/NLRP3 mRNA signalling. Furthermore, resveratrol attenuated CIH-induced oxidative stress through elevation antioxidant molecules expression via NF-E2-related factor-2 (Nrf2). Moreover, AMPK may play a role in Nrf2/HO-1 signalling by resveratrol. These results expand our understanding of the myocardial protective mechanism of resveratrol during CIH and suggest that resveratrol treatment may be useful to counteract OSA-associated cardiac injury.

Resveratrol prevents chronic intermittent hypoxia-induced cardiac hypertrophy by targeting the PI3K/AKT/mTOR pathway.

AIMS: Resveratrol is a polyphenolic compound that has received much attention for its use in ameliorating various systemic pathological conditions. The present study was performed to investigate whether the resveratrol alleviated cardiac hypertrophy and functional remodelling by regulating autophagy. MATERIALS AND METHODS: Male rats were exposed to CIH 8 h/day for five weeks and/or intragastric administration of resveratrol daily. The morphological and echocardiography were used to evaluate the cardiac protective effects. The apoptosis was detected by TUNEL staining. The biochemical assessments were used to evaluate oxidative stress. Further, the effect of resveratrol on autophagy and PI3K/AKT/mTOR pathway was investigated. KEY FINDINGS: The CIH group exhibited increased heart weight/body weight and left ventricle weight/body weight ratios, which was accompanied by left ventricular remodelling. Echocardiography analysis showed that CIH-treated rats had significantly higher left ventricular posterior wall thickness, ejection fraction and fractional shortening than those of controls. In addition, the apoptosis index and oxidative markers were significantly elevated in the CIH group versus the control. The autophagy marker Beclin-1 was elevated, while p62 was decreased by CIH treatment. Resveratrol treatment significantly improved cardiac function and alleviated cardiac hypertrophy, oxidative stress, and apoptosis in CIH rats. Further results indicated that PI3K/AKT pathway-mediated inhibition of the mammalian target of rapamycin (mTOR) pathway played a role in the activation of autophagy by resveratrol after CIH stimulation. SIGNIFICANCE: In conclusion, resveratrol supplementation during CIH upregulates autophagy by targeting the PI3K/AKT/mTOR pathway, which appears to be beneficial for resisting cardiac hypertrophy.

[The effects of Xiaotan Huayu Liqiao formula on mesenteric artery function in rats exposed to chronic intermittent hypoxia].

OBJECTIVE: To investigate the effects of Xiaotan Huayu Liqiao formula (the Chinese Medicine) on mesenteric artery function in rats exposed to chronic intermittent hypoxia (CIH), and to explore the related mechanism. METHODS: Forty-eight male SD rats were randomly divided into four groups as Normoxia, CIH, Formula+CIH and formula group. Rats were exposed to normoxia in the Normoxia and Formula group, or intermittent hypoxia in CIH or Formula+CIH group. Xiaotan Huayu Liqiao formula was given at 24g/kg by intragastric administration before intermittent hypoxia exposure. The pathological changes of mesenteric artery were determined by HE staining, and the relaxation of mesenteric artery (induced by acetylcholine(ACh) and L-arginine(L-Arg)) was recorded by microvascular ring technique. Serums of all rats were collected (0 d and 21 d) and the content of NO was detected by ELISA. The levels of endothelial nitric oxide synthase (eNOS) and p-eNOS were measured by Western blot. RESULTS: Compared with Normoxia group, the mesenteric arterial endothelial injury and media thickening were observed and the relaxation of mesenteric artery was significantly reduced in rats exposed to CIH. The level of NO in serum and the ratio of p-eNOS/eNOS were also decreased in the CIH group. Xiaotan Huayu Liqiao formula administration improved the pathologic changes and dilatation function of mesenteric artery, increased the levels of NO and p-eNOS. Compared with Normoxia group,all the results were not observed significant difference in Formula group. CONCLUSION: Xiaotan Huayu Liqiao formula increased the bioavailability of NO, and ameliorated the CIH induced mesenteric artery function injury.

Hydrogen protects against chronic intermittent hypoxia induced renal dysfunction by promoting autophagy and alleviating apoptosis.

AIMS: Hydrogen gas (H2) has a diversity of effects such as anti-apoptotic, anti-inflammatory and anti-oxidative properties. However, molecular mechanism underlying the potential effect of H2 on chronic intermittent hypoxia (CIH) induced renal injury remains obscure. MATERIALS AND METHODS: In the present study, adult male Sprague-Dawley rats were randomly allocated into four groups: control (CON) group, CIH group, CIH with H2 treatment (CIH + H2) group, and control with H2 treatment (CON + H2) group. Oxidative stress, autophagy and endoplasmic reticulum (ER) stress were detected to determine how H2 affected the renal function of CIH exposed rats. KEY FINDINGS: We demonstrated that rats who inhale hydrogen gas showed improved renal function, alleviated pathological damage, oxidative stress and apoptosis in CIH rats. Meanwhile, CIH-induced endoplasmic reticulum stress was decreased by H2 as the expressions of CHOP, caspase-12, and GRP78 were down-regulated. Furthermore, relative higher levels of LC3-II/I ratio and Beclin-1, with decreased expression of p62, were found after H2 administrated. Inhibition of mTOR may be involved in the upregulation of autophagy by H2. Finally, increased phosphorylation of p38 and JNK was involved in the CIH-induced pathological process. H2 could inhibit the activation of p38 and JNK, suggesting H2 played an active part in resisting renal injury via MAPK. SIGNIFICANCE: Taken together, our study reveals that H2 can ameliorate CIH-induced kidney injury by decreasing endoplasmic reticulum stress and activating autophagy through inhibiting oxidative stress-dependent p38 and JNK MAPK activation.

Hydrogen and Oxygen Mixture to Improve Cardiac Dysfunction and Myocardial Pathological Changes Induced by Intermittent Hypoxia in Rats.

Obstructive sleep apnea (OSA) can cause intermittent changes in blood oxygen saturation, resulting in the generation of many reactive oxygen species (ROS). To discover new antioxidants and clarify the endoplasmic reticulum (ER) stress involved in cardiac injury in OSA, we established a chronic intermittent hypoxia (CIH) rat model with a fraction of inspired O2 (FiO2) ranging from 21% to 9%, 20 times/h for 8 h/day, and the rats were treated with H2-O2 mixture (67% hydrogen and 33% oxygen) for 2 h/day for 35 days. Our results showed that H2-O2 mixture remarkably improved cardiac dysfunction and myocardial fibrosis. We found that H2-O2 mixture inhalation declined ER stress-induced apoptosis via three major response pathways: PERK-eIF2α-ATF4, IRE 1-XBP1, and ATF 6. Furthermore, we revealed that H2-O2 mixture blocked c-Jun N-terminal kinase- (JNK-) MAPK activation, increased the ratio of Bcl-2/Bax, and inhibited caspase 3 cleavage to protect against CIH-induced cardiac apoptosis. In addition, H2-O2 mixture considerably decreased ROS levels via upregulating superoxide dismutase (SOD) and glutathione (GSH) as well as downregulating NADPH oxidase (NOX 2) expression in the hearts of CIH rats. All the results demonstrated that H2-O2 mixture significantly reduced ER stress and apoptosis and that H2 might be an efficient antioxidant against the oxidative stress injury induced by CIH.

Hydrogen Gas Alleviates Chronic Intermittent Hypoxia-Induced Renal Injury through Reducing Iron Overload.

Iron-induced oxidative stress has been found to be a central player in the pathogenesis of kidney injury. Recent studies have indicated H2 can be used as a novel antioxidant to protect cells. The present study was designed to investigate the protective effects of H2 against chronic intermittent hypoxia (CIH)-induced renal injury and its correlation mechanism involved in iron metabolism. We found that CIH-induced renal iron overloaded along with increased apoptosis and oxidative stress. Iron accumulates mainly occurred in the proximal tubule epithelial cells of rats as showed by Perl's stain. Moreover, we found that CIH could promote renal transferrin receptor and divalent metal transporter-1 expression, inhibit ceruloplasmin expression. Renal injury, apoptosis and oxidative stress induced by CIH were strikingly attenuated in H2 treated rats. In conclusion, hydrogen may attenuate CIH-induced renal injury at least partially via inhibiting renal iron overload.

Hydrogen gas reduces chronic intermittent hypoxia-induced hypertension by inhibiting sympathetic nerve activity and increasing vasodilator responses via the antioxidation.

Molecular hydrogen is reported to be used medically to ameliorate various systemic pathological conditions. This study aimed to investigate the effect of hydrogen (H2 ) gas on hypertension induced by intermittent hypoxia in rats. The adult rats were exposed to chronic intermittent hypoxia (CIH) 8 hours/day for 5 weeks and/or H 2 gas 2 hours/day. We found that the systolic and diastolic blood pressure (BP) increased significantly in rats exposed to intermittent hypoxia, both of which were markedly attenuated after H treatment. Furthermore, intermittent hypoxia exposure elevated renal sympathetic nerve activity, consistent with plasma norepinephrine. Additionally, H 2 gas significantly improved CIH-induced abnormal vascular relaxation. Nevertheless, inhalation of H 2 gas alone did not cause such changes. Moreover, H 2 gas-treated rats exposed to CIH showed a significant reduction in 8-hydroxy-2 deoxyguanosine content and increases in superoxide dismutase activity, indicating improved oxidative stress. Taken together, these results indicate that H 2 gas has significant effects on the reduction of BP without any side effects. Mechanistically, inhibition of sympathetic activity and reduction of systemic vascular resistance may participate in this process via the antioxidant activity of H 2 .

Protective role of Gentianella acuta on isoprenaline induced myocardial fibrosis in rats via inhibition of NF-κB pathway.

Gentianella acuta (Michx.) Hulten (G. acuta) has been widely used in Mongolian medicines for the treatment of cardiovascular diseases in Ewenki and Oroqen, Inner Mongolia autonomous region, China. The aim of this study was to investigate the effects and related mechanism of G. acuta on isoproterenol (ISO)-induced oxidative stress, fibrosis, and myocardial damage in rats. Male Sprague Dawley rats were randomly divided into the normal control group, ISO induced group and ISO+G. acuta treatment group. Rats were administered with ISO subcutaneously (5 mg/kg/day) for 7 days, and were orally administered simultaneously with aqueous extracts of G. acuta for 21 days. This investigation showed G. acuta treatment ameliorated cardiac structural disorder, excessive collagenous fiber accumulation and cardiac malfunction. Compared with the ISO induced model group, G. acuta treatment increased superoxide dismutase (SOD) activities and glutathione (GSH) level, prevented the rise of malondialdehyde (MDA), and decreased hydroxyproline contents in the heart tissues. Moreover, G. acuta reduced the expression of transforming growth factor ß1 (TGF-ß1) and connective tissue growth factor (CTGF), and inhibited the expression and activation of NF-κB-P65 in myocardial tissues. These results suggested that G. acuta protects against ISO-induced cardiac malfunction probably by preventing oxidative stress, and fibrosis, and the mechanism might be through inhibiting NF-κB pathway.

Fasudil improves endothelial dysfunction in rats exposed to chronic intermittent hypoxia through RhoA/ROCK/NFATc3 pathway.

Endothelial dysfunction is one of the main pathological changes in Obstructive sleep apnoea (OSA). The Rho kinase (ROCK) pathway is associated with endothelial dysfunction. However, the interaction between ROCK and nuclear factor of activated T cells isoform c3 (NFATc3) in the development of this pathological response under chronic intermittent hypoxia (CIH) is unclear. To simulate the OSA model, we established a moderate CIH rat model by administering the fraction of inspired O2 (FiO2) from 21% to 9%, 20 times/h, 8 h/day for 3 weeks. Fasudil (ROCK inhibitor, 8 mg/kg/d, i.p.) was administrated in the rats exposed to CIH for 3 weeks. Our results demonstrated that CIH caused significantly endothelial dysfunction, accompanying with increased ET-1 level, decreased eNOS expression and NO production, which reduced ACh-induced vascular relaxation responses. Moreover, RhoA/ROCK-2/NFATc3 expressions were up-regulated. Fasudil significantly improved CIH induced endothelial dysfunction. Data suggested that the ROCK activation is necessary for endothelial dysfunction during CIH.

Ceruloplasmin, a Potential Therapeutic Agent for Alzheimer's Disease.

AIMS: Ceruloplasmin (CP), a ferrous oxidase enzyme, plays an important role in regulating iron metabolism and redox reactions. Previous studies showed that CP deficiency contributes to Parkinson's disease by increasing iron accumulation and oxidative stress in the substantia nigra. However, the role of CP in Alzheimer's disease (AD) is unclear. We hypothesized that the lack of CP gene expression would affect the pathogenesis and damage of AD by promoting abnormal iron levels and oxidative stress. RESULTS: AD mouse models were induced in CP knockout mouse either by injection of Aß25-35 into the lateral ventricle of the brain or transgenic APP expression. CP levels were decreased significantly in the hippocampus of AD patients, as well as Aß-CP+/+ and APP-CP+/+ mice. Compared to control AD mice, CP gene deletion increased memory impairment and iron accumulation, which could be associated with elevated reactive oxygen species (ROS) levels and lead to cell apoptosis mediated through the Bcl-2/Bax and Erk/p38 signaling pathways in Aß-CP-/- and APP-CP-/- mice. In contrast, the restoration of CP expression to CP-/- mice through injection of an exogenous expression plasmid into the brain ventricle alleviated Aß-induced neuronal damage in the hippocampus. INNOVATION: CP alterations in iron contents were mediated through DMT1(-IRE) and changes in ROS levels, which in turn attenuated the progression of AD through the Erk/p38 and Bcl-2/Bax signaling pathways. CONCLUSION: Our results show a protective role of CP in AD and suggest that regulating CP expression in the hippocampus may provide a new neuroprotective strategy for AD. Antioxid. Redox Signal. 28, 1323-1337.

Tanshinone IIA ameliorated endothelial dysfunction in rats with chronic intermittent hypoxia.

Chronic intermittent hypoxia (CIH) during repetitive airflow cessations may cause endothelial dysfunction. Tanshinone IIA (Tan IIA) has been used to treat various circulatory disturbance-related diseases because of its pharmacological actions, including vasodilation. However, the mechanism of the effect of its vasodilation is not well established. The objective of this study was to explore the effect of Tan IIA in endothelium-dependent contracting factors and endothelin receptors in aortic endothelial dysfunction in CIH rats. Aortas of rats were retrieved for use in in vitro experiments (isometric force measurement), histological analysis, immunohistochemistry, and Western blotting. Tan IIA treatment increased the expression of endothelial nitric oxide synthase (eNOS) and formation of nitric oxide (NO), inhibited the production of endothelin-1 (ET-1), down-regulated ETA receptor expression, and up-regulated ETB receptor expression. In conclusion, Tan IIA protects endothelial function by inhibiting strain-induced ET-1 expression, decreasing ETA receptors, increasing ETB receptors, increasing the formation of NO, and up-regulating eNOS in CIH.

Tanshinone IIA protects against chronic intermittent hypoxia-induced myocardial injury via activating the endothelin 1 pathway.

Tanshinone IIA (Tan IIA) may exert significant protective effects against heart oxidative stress damage in obstructive sleep apnoea (OSA) syndrome. Chronic intermittent hypoxia (CIH)-triggered left ventricular dysfunction is used in a rat model to mimic CIH in OSA patients. 48 rats were randomly divided into three groups: normal control (NC) group, CIH group and CIH+Tan IIA group with 16 rats in each group. At the end of experiment (day 21), the blood pressure, Plasma ET-1 and NO content, hemodynamic indexes, heart histology, myocardial apoptosis as well as the expression of eNOS, ET-1, ETA receptor and ETB receptor were compared among different groups. Tan IIA was able to inhibit the increase of blood pressure induced by CIH. Meanwhile, rat cardiac function in Tan IIA group was evaluated by hemodynamic indexes, histopathological examination. Higher ventricular eNOS activity was induced by Tan IIA with a reduction in both ET-1 and ETA receptor expression. However, Tan IIA largely inhibited the decrease of ETB receptor expression. This study demonstrated that Tan IIA has the potential to benefit rat heart against CIH via endothelin system.

Mitochondrial ferritin, a new target for inhibiting neuronal tumor cell proliferation.

Mitochondrial ferritin (FtMt) has a significant effect on the regulation of cytosolic and mitochondrial iron levels. However, because of the deficiency of iron regulatory elements (IRE) in FtMt's gene sequence, the exact function of FtMt remains unclear. In the present study, we found that FtMt dramatically inhibited SH-SY5Y cell proliferation and tumor growth in nude mice. Interestingly, excess FtMt did not adversely affect the development of drosophila. Additionally, we found that the expression of FtMt in human normal brain tissue was significantly higher than that of neuroblastoma, but not higher than that of neurospongioma. However, the expression of transferrin receptor 1 is completely opposite. We therefore hypothesized that increased expression of FtMt may negatively affect the vitality of neuronal tumor cells. Therefore, we further investigated the underlying mechanisms of FtMt's inhibitory effects on neuronal tumor cell proliferation. As expected, FtMt overexpression disturbed the iron homeostasis of tumor cells and significantly downregulated the expression of proliferating cell nuclear antigen. Moreover, FtMt affected cell cycle, causing G1/S arrest by modifying the expression of cyclinD1, cyclinE, Cdk2, Cdk4 and p21. Remarkably, FtMt strongly upregulated the expression of the tumor suppressors, p53 and N-myc downstream-regulated gene-1 (NDRG1), but dramatically decreased C-myc, N-myc and p-Rb levels. This study demonstrates for the first time a new role and mechanism for FtMt in the regulation of cell cycle. We thus propose FtMt as a new candidate target for inhibiting neuronal tumor cell proliferation. Appropriate regulation of FtMt expression may prevent tumor cell growth. Our study may provide a new strategy for neuronal cancer therapy.