Vascular smooth muscle-specific LRRC8A knockout ameliorates angiotensin II-induced cerebrovascular remodeling by inhibiting the WNK1/FOXO3a/MMP signaling pathway.

Hypertensive cerebrovascular remodeling involves the enlargement of vascular smooth muscle cells (VSMCs), which activates volume-regulated Cl- channels (VRCCs). The leucine-rich repeat-containing family 8 A (LRRC8A) has been shown to be the molecular identity of VRCCs. However, its role in vascular remodeling during hypertension is unclear. In this study, we used vascular smooth muscle-specific LRRC8A knockout (CKO) mice and an angiotensin II (Ang II)-induced hypertension model. The results showed that cerebrovascular remodeling during hypertension was ameliorated in CKO mice, and extracellular matrix (ECM) deposition was reduced. Based on the RNA-sequencing analysis of aortic tissues, the level of matrix metalloproteinases (MMPs), such as MMP-9 and MMP-14, were reduced in CKO mice with hypertension, which was further verified in vivo by qPCR and immunofluorescence analysis. Knockdown of LRRC8A in VSMCs inhibited the Ang II-induced upregulation of collagen I, fibronectin, and matrix metalloproteinases (MMPs), and overexpression of LRRC8A had the opposite effect. Further experiments revealed an interaction between with-no-lysine (K)-1 (WNK1), which is a "Cl--sensitive kinase", and Forkhead transcription factor O3a (FOXO3a), which is a transcription factor that regulates MMP expression. Ang II induced the phosphorylation of WNK1 and downstream FOXO3a, which then increased the expression of MMP-2 and MMP-9. This process was inhibited or potentiated when LRRC8A was knocked down or overexpressed, respectively. Overall, these results demonstrate that LRRC8A knockout in vascular smooth muscle protects against cerebrovascular remodeling during hypertension by reducing ECM deposition and inhibiting the WNK1/FOXO3a/MMP signaling pathway, demonstrating that LRRC8A is a potential therapeutic target for vascular remodeling-associated diseases such as stroke.

Dual action of macrophage miR-204 confines cyclosporine A-induced atherosclerosis.

BACKGROUND AND PURPOSE: Atherosclerosis induced by cyclosporine A (CsA), an inhibitor of the calcineurin/nuclear factor of activated T cells (NFAT) pathway, is a major concern after organ transplantation. However, the atherosclerotic mechanisms of CsA remain obscure. We previously demonstrated that calcineurin/NFAT signalling inhibition contributes to atherogenesis via suppressing microRNA-204 (miR-204) transcription. We therefore hypothesised that miR-204 is involved in the development of CsA-induced atherosclerosis. EXPERIMENTAL APPROACH: ApoE-/- mice with macrophage-miR-204 overexpression were generated to determine the effects of miR-204 on CsA-induced atherosclerosis. Luciferase reporter assays and chromatin immunoprecipitation sequencing were performed to explore the targets mediating miR-204 effects. KEY RESULTS: CsA alone did not significantly affect atherosclerotic lesions or serum lipid levels. However, it exacerbated high-fat diet-induced atherosclerosis and hyperlipidemia in C57BL/6J and ApoE-/- mice, respectively. miR-204 levels decreased in circulating monocytes and plaque lesions during CsA-induced atherosclerosis. The upregulation of miR-204 in macrophages inhibited CsA-induced atherosclerotic plaque formation but did not affect serum lipid levels. miR-204 limited the CsA-induced foam cell formation by reducing the expression of the scavenger receptors SR-BII and CD36. SR-BII was post-transcriptionally regulated by mature miR-204-5p via 3'-UTR targeting. Additionally, nuclear-localised miR-204-3p prevented the CsA-induced binding of Ago2 to the CD36 promoter, suppressing CD36 transcription. SR-BII or CD36 expression restoration dampened the beneficial effects of miR-204 on CsA-induced atherosclerosis. CONCLUSION AND IMPLICATIONS: Macrophage miR-204 ameliorates CsA-induced atherosclerosis, suggesting that miR-204 may be a potential target for the prevention and treatment of CsA-related atherosclerotic side effects.

Low Chloride-Regulated ClC-5 Contributes to Arterial Smooth Muscle Cell Proliferation and Cerebrovascular Remodeling.

BACKGROUND: Low serum chloride (Cl-) level is considered an independent predictor of cardiovascular mortality associated with chronic hypertension. However, the underlying mechanisms are unknown. ClC-5, a member of the Cl- channel family, is sensitive to changes in intracellular and extracellular Cl- concentration and conducts outwardly rectifying Cl- currents. The aims of this study were to determine if ClC-5 is regulated by low extracellular Cl-, clarify its putative roles in hypertension-induced cerebrovascular remodeling, and elucidate the associated underlying mechanisms. METHODS: Whole-cell patch technique, intracellular Cl- concentration measurements, flow cytometry, Western blot, Clcn5 knockdown (Clcn5-/y), and adenovirus-mediated ClC-5 overexpression mice, 2-kidney, 2-clip, and angiotensin II infusion-induced hypertensive models were used. RESULTS: We found that low extracellular Cl- evoked a ClC-5-dependent Cl- current that was abolished by ClC-5 depletion in basilar artery smooth muscle cells (BASMCs). ClC-5 was upregulated in the arterial tissues of rats and patients with hypertension. Low Cl--induced current and ClC-5 protein expression positively correlated with basilar artery remodeling during hypertension. ClC-5 knockdown ameliorated hypertension-induced cerebrovascular remodeling and smooth muscle cell proliferation, whereas ClC-5 overexpression mice exhibited the opposite phenotype. ClC-5-dependent Cl- efflux induced by low extracellular Cl- activated WNK1 (lysine-deficient protein kinase 1) which, in turn, activated AKT (protein kinase B), and culminated in BASMC proliferation and vascular remodeling. CONCLUSIONS: ClC-5 mediates low extracellular Cl-induced Cl- currents in BASMCs and regulates hypertension-induced cerebrovascular remodeling by promoting BASMC proliferation via the WNK1/AKT signaling pathway.

LRRC8A is essential for volume-regulated anion channel in smooth muscle cells contributing to cerebrovascular remodeling during hypertension.

OBJECTIVES: Recent studies revealed LRRC8A to be an essential component of volume-regulated anion channel (VRAC), which regulates cellular volume homeostasis. However, evidence for the contribution of LRRC8A-dependent VRAC activity in vascular smooth muscle cells (VSMCs) is still lacking, and the relevant functional role of LRRC8A in VSMCs remains unknown. The primary goal of this study was to elucidate the role of LRRC8A in VRAC activity in VSMCs and the functional role of LRRC8A in cerebrovascular remodeling during hypertension. MATERIALS AND METHODS: siRNA-mediated knockdown and adenovirus-mediated overexpression of LRRC8A were used to elucidate the electrophysiological properties of LRRC8A in basilar smooth muscle cells (BASMCs). A smooth muscle-specific overexpressing transgenic mouse model was used to investigate the functional role of LRRC8A in cerebrovascular remodeling. RESULTS: LRRC8A is essential for volume-regulated chloride current (ICl, Vol ) in BASMCs. Overexpression of LRRC8A induced a voltage-dependent Cl- current independently of hypotonic stimulation. LRRC8A regulated BASMCs proliferation through activation of WNK1/PI3K-p85/AKT axis. Smooth muscle-specific upregulation of LRRC8A aggravated Angiotensin II-induced cerebrovascular remodeling in mice. CONCLUSIONS: LRRC8A is an essential component of VRAC and is required for cell volume homeostasis during osmotic challenge in BASMCs. Smooth muscle specific overexpression of LRRC8A increases BASMCs proliferation and substantially aggravates basilar artery remodeling, revealing a potential therapeutic target for vascular remodeling in hypertension.

Macrophage NFATc3 prevents foam cell formation and atherosclerosis: evidence and mechanisms.

AIMS: Our previous study demonstrated that Ca2+ influx through the Orai1 store-operated Ca2+ channel in macrophages contributes to foam cell formation and atherosclerosis via the calcineurin-ASK1 pathway, not the classical calcineurin-nuclear factor of activated T-cell (NFAT) pathway. Moreover, up-regulation of NFATc3 in macrophages inhibits foam cell formation, suggesting that macrophage NFATc3 is a negative regulator of atherogenesis. Hence, this study investigated the precise role of macrophage NFATc3 in atherogenesis. METHODS AND RESULTS: Macrophage-specific NFATc3 knockout mice were generated to determine the effect of NFATc3 on atherosclerosis in a mouse model of adeno-associated virus-mutant PCSK9-induced atherosclerosis. NFATc3 expression was decreased in macrophages within human and mouse atherosclerotic lesions. Moreover, NFATc3 levels in peripheral blood mononuclear cells from atherosclerotic patients were negatively associated with plaque instability. Furthermore, macrophage-specific ablation of NFATc3 in mice led to the atherosclerotic plaque formation, whereas macrophage-specific NFATc3 transgenic mice exhibited the opposite phenotype. NFATc3 deficiency in macrophages promoted foam cell formation by potentiating SR-A- and CD36-meditated lipid uptake. NFATc3 directly targeted and transcriptionally up-regulated miR-204 levels. Mature miR-204-5p suppressed SR-A expression via canonical regulation. Unexpectedly, miR-204-3p localized in the nucleus and inhibited CD36 transcription. Restoration of miR-204 abolished the proatherogenic phenotype observed in the macrophage-specific NFATc3 knockout mice, and blockade of miR-204 function reversed the beneficial effects of NFATc3 in macrophages. CONCLUSION: Macrophage NFATc3 up-regulates miR-204 to reduce SR-A and CD36 levels, thereby preventing foam cell formation and atherosclerosis, indicating that the NFATc3/miR-204 axis may be a potential therapeutic target against atherosclerosis.

TMEM16A ameliorates vascular remodeling by suppressing autophagy via inhibiting Bcl-2-p62 complex formation.

Rationale: Transmembrane member 16A (TMEM16A) is a component of calcium-activated chloride channels that regulate vascular smooth muscle cell (SMC) proliferation and remodeling. Autophagy, a highly conserved cellular catabolic process in eukaryotes, exerts important physiological functions in vascular SMCs. In the current study, we investigated the relationship between TMEM16A and autophagy during vascular remodeling. Methods: We generated a transgenic mouse that overexpresses TMEM16A specifically in vascular SMCs to verify the role of TMEM16A in vascular remodeling. Techniques employed included immunofluorescence, electron microscopy, co-immunoprecipitation, and Western blotting. Results: Autophagy was activated in aortas from angiotensin II (AngII)-induced hypertensive mice with decreased TMEM16A expression. The numbers of light chain 3B (LC3B)-positive puncta in aortas correlated with the medial cross-sectional aorta areas and TMEM16A expression during hypertension. SMC-specific TMEM16A overexpression markedly inhibited AngII-induced autophagy in mouse aortas. Moreover, in mouse aortic SMCs (MASMCs), AngII-induced autophagosome formation and autophagic flux were blocked by TMEM16A upregulation and were promoted by TMEM16A knockdown. The effect of TMEM16A on autophagy was independent of the mTOR pathway, but was associated with reduced kinase activity of the vacuolar protein sorting 34 (VPS34) enzyme. Overexpression of VPS34 attenuated the effect of TMEM16A overexpression on MASMC proliferation, while the effect of TMEM16A downregulation was abrogated by a VPS34 inhibitor. Further, co-immunoprecipitation assays revealed that TMEM16A interacts with p62. TMEM16A overexpression inhibited AngII-induced p62-Bcl-2 binding and enhanced Bcl-2-Beclin-1 interactions, leading to suppression of Beclin-1/VPS34 complex formation. However, TMEM16A downregulation showed the opposite effects. Conclusion: TMEM16A regulates the four-way interaction between p62, Bcl-2, Beclin-1, and VPS34, and coordinately prevents vascular autophagy and remodeling.

SGK1 mediates the hypotonic protective effect against H2O2-induced apoptosis of rat basilar artery smooth muscle cells by inhibiting the FOXO3a/Bim signaling pathway.

Serum- and glucocorticoid-inducible kinease-1 (SGK1) is a serine/threonine kinase regulated by hypotonic stimuli, which is involved in regulation of cell cycle and apoptosis. Our previous study shows that activation of volume-regulated Cl- channels (VRCCs) protects rat basilar artery smooth muscle cells (BASMCs) against hydrogen peroxide (H2O2)-induced apoptosis. In the present study, we investigated whether SGK1 was involved in the protective effect of VRCCs in BASMCs. We showed that hypotonic challenge significantly reduced H2O2-induced apoptosis, and increased SGK1 phosphorylation, but did not affect SGK1 protein expression. The protective effect of hypotonic challenge against H2O2-induced apoptosis was mediated through inhibiting mitochondria-dependent apoptotic pathway, evidenced by increased Bcl-2/Bax ratio, stabilizing mitochondrial membrane potential (MMP), decreased cytochrome c release from the mitochondria to the cytoplasm, and inhibition of the activation of caspase-9 and caspase-3. These protective effects of hypotonic challenge against H2O2-induced apoptosis was diminished and enhanced, respectively, by SGK1 knockdown and overexpression. We further revealed that SGK1 activation significantly increased forkhead box O3a (FOXO3a) phosphorylation, and then inhibited the translocation of FOXO3a into nucleus and the subsequent expression of Bcl-2 interacting mediator of cell death (Bim). In conclusion, SGK1 mediates the protective effect of VRCCs against H2O2-induced apoptosis in BASMCs via inhibiting FOXO3a/Bim signaling pathway. Our results provide compelling evidences that SGK1 is a critical link between VRCCs and apoptosis, and shed a new light on the treatment of vascular apoptosis-associated diseases, such as vascular remodeling, angiogenesis, and atherosclerosis.

Reduction of glyoxalase 1 (GLO1) aggravates cerebrovascular remodeling via promoting the proliferation of basilar smooth muscle cells in hypertension.

Uncontrollable vascular smooth cell proliferation is responsible for vascular remodeling during hypertension development. Glyoxalase 1 (GLO1), the major enzyme detoxifying methylglyoxal, has a critical role in regulating proliferation of several cell types. However, little is known whether GLO1 is involved in cerebrovascular remodeling and basilar smooth muscle cell (BASMC) proliferation during hypertension. Here we explored the role of GLO1 in angiotensin II (Ang II)-induced cerebrovascular remodeling and proliferation of BASMCs and the underlying mechanisms. The protein expression of GLO1 in basilar arteries from hypertensive mice was decreased, and GLO1 expression was negatively correlated with medial cross-sectional area and blood pressure in basilar arteries during hypertension. Knockdown of GLO1 promoted while overexpression of GLO1 prevented Ang II-induced cell proliferation and cell cycle transition in BASMCs. These results were related to the inhibitory effects of GLO1 on PI3K/AKT/CDK2 cascade activation upon Ang II treatment. In addition, in vivo study, GLO1 overexpression with adeno-associated virus harboring GLO1 cDNA improved cerebrovascular remodeling in basilar artery tissue during Ang II-induced hypertension development. These data indicate that GLO1 reduction mediates cerebrovascular modeling via PI3K/AKT/CDK2 cascade-dependent BASMC proliferation. GLO1 acts as a negative regulator of hypertension-induced cerebrovascular remodeling and targeting GLO1 may be a novel therapeutic strategy to prevent hypertension-associated cardiovascular complications such as stroke.

Free fatty acid-induced H2O2 activates TRPM2 to aggravate endothelial insulin resistance via Ca2+-dependent PERK/ATF4/TRB3 cascade in obese mice.

Transient Receptor Potential Melastatin-2 (TRPM2) is a nonselective cation channel mediating Ca2+ influx in response to oxidative stress. Given that insulin resistance-related endothelial dysfunction in obesity attributes to fatty-acid-induced reactive oxygen species (ROS) overproduction, in this study, we addressed the possible role of TRPM2 in obesity-related endothelial insulin resistance and the underlying mechanisms. Whole-cell patch clamp technique, intracellular Ca2+ concentration measurement, western blot, vasorelaxation assay, and high-fat diet (HFD)-induced obese model were employed to assess the relationship between TRPM2 and endothelial insulin response. We found that both the expression and activity of TRPM2 were higher in endothelial cells of obese mice. Palmitate rose a cationic current in endothelial cells which was inhibited or enlarged by TRPM2 knockdown or overexpression. Silencing of TRPM2 remarkably improved insulin-induced endothelial Akt activation, nitric oxide synthase (eNOS) phosphorylation and nitric oxide (NO) production, while TRPM2 overexpression resulted in the opposite effects. Furthermore, TRPM2-mediated Ca2+ entry, CaMKII activation and the following activation of PERK/ATF4/TRB3 cascade were involved in the mechanism of obesity or palmitate-induced endothelial insulin resistance. Notably, in vivo study, knockdown of TRPM2 with adeno-associated virus harboring short-hairpin RNA (shRNA) against TRPM2 alleviated endothelial insulin resistance and ameliorated endothelium-dependent vasodilatation in obese mice. Thus, these results suggest that TRPM2-activated Ca2+ signaling is necessary to induce insulin resistance-related endothelial dysfunction in obesity. Downregulation or pharmacological inhibition of TRPM2 channels may lead to the development of effective drugs for treatment of endothelial dysfunction associated with oxidative stress state.

Clcn3 deficiency ameliorates high-fat diet-induced obesity and adipose tissue macrophage inflammation in mice.

Obesity induces accumulation of adipose tissue macrophages (ATMs) and ATM-driven inflammatory responses that promote the development of glucose and lipid metabolism disorders. ClC-3 chloride channel/antiporter, encoded by the Clcn3, is critical for some basic cellular functions. Our previous work has shown significant alleviation of type 2 diabetes in Clcn3 knockout (Clcn3-/-) mice. In the present study we investigated the role of Clcn3 in high-fat diet (HFD)-induced obesity and ATM inflammation. To establish the mouse obesity model, both Clcn3-/- mice and wild-type mice were fed a HFD for 4 or 16 weeks. The metabolic parameters were assessed and the abdominal total adipose tissue was scanned using computed tomography. Their epididymal fat pad tissue and adipose tissue stromal vascular fraction (SVF) cells were isolated for analyses. We found that the HFD-fed Clcn3-/- mice displayed a significant decrease in obesity-induced body weight gain and abdominal visceral fat accumulation as well as an improvement of glucose and lipid metabolism as compared with HFD-fed wild-type mice. Furthermore, the Clcn3 deficiency significantly attenuated HFD-induced ATM accumulation, HFD-increased F4/80+ CD11c+ CD206- SVF cells as well as HFD-activated TLR-4/NF-κB signaling in epididymal fat tissue. In cultured human THP-1 macrophages, adenovirus-mediated transfer of Clcn3 specific shRNA inhibited, whereas adenovirus-mediated cDNA overexpression of Clcn3 enhanced lipopolysaccharide-induced activation of NF-κB and TLR-4. These results demonstrate a novel role for Clcn3 in HFD-induced obesity and ATM inflammation.

Effects of ginkgo biloba extract on the cognitive function and expression profile of inflammatory factors in a rat model of hemorrhagic stroke.

Hemorrhagic stroke is a major risk factor for cognitive impairment. Our study aimed to measure the effect of ginkgo biloba extract (EGB761) on the cognitive ability and inflammatory expression in hemorrhagic stroke model SD rats and to analyze their relationship. Forty SD rats were divided randomly into an SD group (normal control SD rats), an SD+EGB761 group (normal control SD rats supplemented with 45 mg/kg EGB761), a CO group (hemorrhagic stroke model SD rats using collagenase), and a CO+EGB761 group (hemorrhagic stroke model SD rats supplemented with 45 mg/kg EGB761) consisting of 10 rats, respectively. The Y-electric maze test was selected to measure the cognitive function in four groups. Furthermore, enzyme-linked immunosorbent assay and real-time PCR were, respectively, applied for detecting the protein and gene expression profiles of inflammatory factors in primary cultured microglia. Compared with rats in the SD group, the average time of electrical simulation for mastering criteria was prolonged in the CO group (P<0.05). Furthermore, expression levels of proinflammatory cytokines interleukin-1ß (IL-1ß), IL-6, and tumor necrosis factor-α and anti-inflammatory cytokines IL-4, IL-10, and tumor necrosis factor-ß were significantly increased and decreased, respectively, in rats of the CO group compared with the SD group (P<0.05). The results of electrical simulation time, inflammatory factors protein, and gene expression profile in rats of the CO+EGB761 group compared with the CO group were opposite to above contrast (P<0.05). Ginkgo biloba extract could alleviate the cognitive dysfunction after hemorrhagic stroke in SD rats; this is associated with regulating the expression of inflammatory factors secreted by microglia.

WNK1 is required for proliferation induced by hypotonic challenge in rat vascular smooth muscle cells.

Hypotonic challenge evoked vascular cell proliferation through activation of volume-regulated Cl- channel (VRCC), leading to a decrease in the intracellular Cl- concentration ([Cl-]i). We hypothesize that the decrease in [Cl-]i may activate one or several Cl--sensitive kinases, resulting in a subsequent signaling cascade. In this study we demonstrated that WNK1, a Cl--sensitive kinase, was involved in VRCC-induced proliferative signaling pathway in A10 vascular smooth muscle cells in vitro. A10 cells were exposed to a hypotonic challenge (225 mosmol·kg-1·H20), which caused significantly increase in WNK1 phosphorylation without altering WNK1 protein expression. WNK1 overexpression significantly increased hypotonic-induced A10 cell proliferation, whereas silencing of WNK1 caused an opposite action. WNK1 mutation did not affect hypotonic-induced WNK1 phosphorylation and cell proliferation. Silencing of WNK1 caused cell cycle arrest at G0/G1 phase and prevented transition from G1 to S phase, whereas the WNK1 overexpression accelerated cell cycle transition from G1 to S phase. Silencing of WNK1 significantly inhibited cyclin D1/cyclin E1 expression and increased p27kip/p21cip expression. WNK1 overexpression significantly increased cyclin D1/cyclin E1 expression and reduced p27KIP/p21CIP expression. In addition, WNK1 knockdown or overexpression significantly attenuated or increased the hypotonic-induced phosphorylation of Akt and PI3K respectively.In conclusion, the reduction in [Cl-]i caused by hypotonic challenge-induced VRCC opening evokes WNK1 phosphorylation in A10 VSMCs, which mediates cell cycle transition from G0/G1 to S phase and proliferation through the PI3K-Akt signaling pathway.

Simvastatin attenuated rat thoracic aorta remodeling by decreasing ROCK2­mediated CyPA secretion and CD147­ERK1/2­cyclin pathway.

Reactive oxygen species­induced cyclophilin A (CyPA) release from vascular smooth muscle cells (VSMCs) may be inhibited by simvastatin in vitro. The present study aimed to further examine the effect of simvastatin on serum CyPA levels and the basigin (CD147)­extracellular signal­regulated kinase (ERK) 1/2­cyclin pathway during thoracic aorta remodeling. The mechanisms through which simvastatin may inhibit CyPA secretion from VSMCs were further investigated. Serum CyPA levels and the expression kinetics of CyPA­associated signaling pathways were examined following simvastatin treatment in rat thoracic aortas during hypertension. Cell lysates were prepared from middle layer of thoracic aortas at 1, 4, 8 and 12 weeks subsequent to surgery. ELISA analysis revealed that serum CyPA levels were gradually increased with the progression of thoracic aorta remodeling. Western blotting demonstrated that the expression of CD147, phosphorylated­ERK1/2, cyclin D1, cyclin A, and cyclin E were increased with the progression of thoracic aorta remodeling. Simvastatin administration for 4, 8 and 12 weeks diminished all these changes, as observed in the hypertensive group. VSMCs from simvastatin­treated rats secreted a decreased amount of CyPA compared with VSMCs from hypertensive rats. In addition, pretreatment with geranylgeraniol partly reversed the inhibitory effect of simvastatin on LY83583­induced CyPA secretion in cultured VSMCs, whereas GGTI­298 and KD025 [a selective Rho­associated protein kinase 2 (ROCK2) inhibitor] mimicked the inhibitory effect of simvastatin. The present study demonstrated that simvastatin alleviated thoracic aorta remodeling by reducing CyPA secretion and expression of the CD147­ERK1/2­cyclin signaling pathway. In addition, the results of the present study demonstrated that the Rho­ROCK2 pathway mediated CyPA secretion from VSMCs.

Aspirin inhibits the proliferation of human uterine leiomyoma cells by downregulation of K­Ras­p110α interaction.

Aspirin has been confirmed as an effective antitumor drug in various cancers. However, the relationship between aspirin and uterine leiomyoma is still underexplored. Here, we explored the effects of aspirin on human uterine leiomyoma cells and provide insights into the underlying mechanisms. Cell Counting Kit-8 (CCK-8) and flow cytometry analysis showed that aspirin treatment inhibited cell proliferation and promoted cell cycle arrest at G0/G1 phase in a dose- and time­dependent manner of human uterine leiomyoma cells. Further studies revealed that aspirin blocked the interaction between K-Ras and p110α by co-immunoprecipitation and immunofluorescence. Western blotting demonstrated K­Ras­p110α interaction was required for the effects of aspirin­induced inhibition on cell growth and cell cycle transition via cell cycle regulators, including cyclin D1 and cyclin-dependent kinase 2 (CDK2). PI3K/Akt/caspase signaling pathway was involved in human uterine leiomyoma cell growth under aspirin treatment. Taken together, these results suggest that aspirin inhibited human uterine leiomyoma cell growth by regulating K­Ras­p110α interaction. Aspirin which targeting on interaction between K-Ras and p110α may serve as a new therapeutic drug for uterine leiomyoma treatment.

TMEM16A Contributes to Endothelial Dysfunction by Facilitating Nox2 NADPH Oxidase-Derived Reactive Oxygen Species Generation in Hypertension.

Ca2+-activated Cl- channels play a crucial role in various physiological processes. However, the role of TMEM16A in vascular endothelial dysfunction during hypertension is unclear. In this study, we investigated the specific involvement of TMEM16A in regulating endothelial function and blood pressure and the underlying mechanism. Reverse transcription-polymerase chain reaction, Western blotting, coimmunoprecipitation, confocal imaging, patch-clamp recordings, and TMEM16A endothelial-specific transgenic and knockout mice were used. We found that TMEM16A was expressed abundantly and functioned as a Ca2+-activated Cl- channel in endothelial cells. Angiotensin II induced endothelial dysfunction with an increase in TMEM16A expression. The knockout of endothelial-specific TMEM16A significantly lowered the blood pressure and ameliorated endothelial dysfunction in angiotensin II-induced hypertension, whereas the overexpression of endothelial-specific TMEM16A resulted in the opposite effects. These results were related to the increased reactive oxygen species production, Nox2-containing NADPH oxidase activation, and Nox2 and p22phox protein expression that were facilitated by TMEM16A on angiotensin II-induced hypertensive challenge. Moreover, TMEM16A directly bound with Nox2 and reduced the degradation of Nox2 through the proteasome-dependent degradation pathway. Therefore, TMEM16A is a positive regulator of endothelial reactive oxygen species generation via Nox2-containing NADPH oxidase, which induces endothelial dysfunction and hypertension. Modification of TMEM16A may be a novel therapeutic strategy for endothelial dysfunction-associated diseases.

Short communication: Camel milk ameliorates inflammatory responses and oxidative stress and downregulates mitogen-activated protein kinase signaling pathways in lipopolysaccharide-induced acute respiratory distress syndrome in rats.

Acute respiratory distress syndrome (ARDS) is a complex syndrome disorder with high mortality rate. Camel milk (CM) contains antiinflammatory and antioxidant properties and protects against numerous diseases. This study aimed to demonstrate the function of CM in lipopolysaccharide (LPS)-induced ARDS in rats. Camel milk reduced the lung wet:dry weight ratio and significantly reduced LPS-induced increases in neutrophil infiltration, interstitial and intra-alveolar edema, thickness of the alveolar wall, and lung injury scores of lung tissues. It also had antiinflammatory and antioxidant effects on LPS-induced ARDS. After LPS stimulation, the levels of proinflammatory cytokines (tumor necrosis factor-α, IL-10, and IL-1ß) in serum and oxidative stress markers (malondialdehyde, myeloperoxidase, and total antioxidant capacity) in lung tissue were notably attenuated by CM. Camel milk also downregulated mitogen-activated protein kinase signaling pathways. Given these results, CM is a potential complementary food for ARDS treatment.

TRPC3 channel confers cerebrovascular remodelling during hypertension via transactivation of EGF receptor signalling.

AIMS: Ionic perturbation in vascular smooth muscle cells contributes to cerebrovascular remodelling in the setting of hypertension, but the role of transient receptor potential (TRP) channel superfamily remains unknown. The present study was conducted to define the contribution of TRP channels to cerebrovascular remodelling. METHODS AND RESULTS: By integrating quantitative PCR, western blotting, patch clamping, and Ca(2+) imaging, we identified TRP channel, subfamily canonical, member 3 (TRPC3) as the channel subtype most considerably elevated in basilar arteries of two-kidney, two-clip stroke-prone hypertensive rats. Importantly, administration of pyrazole 3 (Pyr3), a TRPC3 channel blocker, attenuated cerebrovascular remodelling. During hypertension, epidermal growth factor receptor (EGFR) was transactivated, as evidenced by marked EGFR phosphorylation, increased pro-HB-EGF shedding, and elevated activity of ADAM17 (HB-EGF sheddase). ADAM17 activity was increased owing to enhanced activation rather than elevated expression. Remarkably, Pyr3 treatment suppressed EGFR transactivation in hypertension. In proliferating basilar artery smooth muscle cells or basilar arteries of hypertensive rats, co-immunoprecipitation assay revealed an interaction between TRPC3 and ADAM17 upon Ang II stimulation. CONCLUSION: Collectively, we demonstrated that enhanced EGFR transactivation, due to increased TRPC3 expression and functional coupling of TRPC3/ADAM17, resulted in cerebrovascular remodelling. Therefore, TRPC3-induced EGFR transactivation may be therapeutically exploited to prevent hypertension-induced cerebrovascular remodelling.

ClC-3 deficiency prevents atherosclerotic lesion development in ApoE-/- mice.

BACKGROUND: Recent evidence suggested that ClC-3, encoding Cl(-) channel or Cl(-)/H(+) antiporter, plays a critical role in regulation of a variety of physiological functions. However, remarkably little is known about whether ClC-3 is involved in atherosclerosis. This study aims to establish the involvement and direct role of ClC-3 in atherogenesis and underlying mechanisms by using ClC-3 and ApoE double null mice. METHODS AND RESULTS: After a 16-week western-type high-fat diet, the ClC-3(+/+)ApoE(-/-) mice developed widespread atherosclerotic lesions in aorta. However, the lesion size was significantly reduced in aorta of ClC-3(-/-)ApoE(-/-) mice. Compared with the ClC-3(+/+) controls, there was significantly decreased ox-LDL binding and uptake in isolated peritoneal macrophages from ClC-3(-/-) mice. Moreover, the expression of scavenger receptor SR-A, but not CD36, was significantly decreased in both ClC-3(-/-) peritoneal macrophages and aortic lesions from ClC-3(-/-)ApoE(-/-) mice. These findings were further confirmed in ox-LDL-treated RAW264.7 macrophages, which showed that silence of ClC-3 inhibited SR-A expression, ox-LDL accumulation and foam cell formation, whereas overexpression of ClC-3 produced the opposite effects. In addition, ClC-3 siRNA significantly inhibited, whereas ClC-3 overexpression increased, the phosphorylation of JNK/p38 MAPK in ox-LDL-treated RAW264.7 foam cells. Pretreatment with JNK or p38 inhibitor abolished ClC-3-induced increase in SR-A expression and ox-LDL uptake. Finally, the increased JNK/p38 phosphorylation and SR-A expression induced by ClC-3 could be mimicked by reduction of [Cl(-)]i by low Cl(-) solution. CONCLUSIONS: Our findings demonstrated that ClC-3 deficiency inhibits atherosclerotic lesion development, possibly via suppression of JNK/p38 MAPK dependent SR-A expression and foam cell formation.

Cyanidin-3-O-Glucoside Ameliorates Lipopolysaccharide-Induced Injury Both In Vivo and In Vitro Suppression of NF-κB and MAPK Pathways.

Cyanidin-3-O-glucoside (C3G), an anthocyanin belonging to the flavonoid family and commonly present in food and vegetables in human diet, has exhibited anti-inflammatory and anti-oxidant effects. This study aimed to investigate the protective ability of C3G against inflammatory and oxidative injuries, as well as to clarify the possible mechanism in lipopolysaccharide (LPS)-stimulated human umbilical vein endothelial cells (HUVECs) in vitro and acute respiratory distress syndrome mouse model in vivo. HUVECs or male Kunming mice were pretreated with C3G 1 h before LPS stimulation. C3G significantly inhibited the production of pro-inflammatory cytokines (tumor necrosis factor-α, interleukin (IL) -6, and IL-1ß) in cell supernatants and bronchoalveolar lavage fluid (BALF) as determined by enzyme-linked immunosorbent assay. Histopathologic examination with hematoxylin and eosinstaining showed that C3G pretreatment substantially suppressed inflammatory cell infiltration, alveolar wall thickening, and interstitial edemain lung tissues. C3G markedly prevented LPS-induced elevation of malondialdehyde and myeloperoxidase levels in lung tissue homogenates, wet to dry ratio of lung tissues, total cells, and inflammatory cells (neutrophils and macrophages) in BALF. Moreover, C3G reduced superoxide dismutase activity in the lung tissue homogenates. Western blot assay also showed that C3G pretreatment significantly suppressed LPS-induced activation of nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways by blocking the phosphorylation of inhibitor κB-α, NF-κB/P65, extracellular signal-regulated kinase, p38, and c-Jun NH2-terminal kinase in the lung tissues. In summary, C3G may ameliorate LPS-induced injury, which results from inflammation and oxidation, by inhibiting NF-κB and MAPK pathways and playing important anti-inflammatory and anti-oxidative roles.