LncRNA Gm15834 Aggravates Cardiac Hypertrophy by Interacting with Sam68 and Activating NF-κB Mediated Inflammation.

BACKGROUND: Cardiac hypertrophy is the common pathological process of multiple cardiovascular diseases. However, the molecular mechanisms of cardiac hypertrophy are unclear. Long non-coding RNA (lncRNA), a newly discovered type of transcript that has been demonstrated to function as crucial regulators in the development of cardiovascular diseases. This study revealed a novel regulatory pathway of lncRNA in cardiac hypertrophy. METHODS: The cardiac hypertrophy models were established by transverse aortic constriction (TAC) in mice and angiotensin II (Ang II) in HL-1 cardiomyocytes. Adeno-associated virus 9 (AAV9) in vivo and lncRNA Gm15834 and shRNA plasmids in vitro were used to overexpress and knock down lncRNA Gm15834. The myocardial tissue structure, cardiomyocyte area, cardiac function, protein expressions, and binding of lncRNA Gm15834 and Src-associated substrate during mitosis of 68 KDa (Sam68) were detected by hematoxylin and eosin (HE) staining, immunofluorescence staining, echocardiography, western blot and RNA immunoprecipitation (RIP), respectively. RESULTS: In cardiac hypertrophy models, inhibiting lncRNA Gm15834 could decrease Sam68 expression and nuclear factor kappa-B (NF-κB) mediated inflammatory activities in vivo and in vitro, but overexpressing lncRNA Gm15834 showed the opposite results. RIP experiments validated the binding activities between lncRNA Gm15834 and Sam68. Overexpression of Sam68 could counteract the anti-hypertrophy effects of lncRNA Gm15834 knockdown. Meanwhile, in vivo inhibition of lncRNA Gm15834 could inhibit Sam68 expression, reduce NF-κB mediated inflammatory activity and attenuate cardiac hypertrophy. CONCLUSION: Our study revealed a novel regulatory axis of cardiac hypertrophy, which comprised lncRNA Gm15834/Sam68/NF-κB/inflammation, shedding a new light for identifying therapy target of cardiac hypertrophy in clinic.

Inhibition of lncRNA Gm15834 Attenuates Autophagy-Mediated Myocardial Hypertrophy via the miR-30b-3p/ULK1 Axis in Mice.

Emerging evidence reveals that autophagy plays crucial roles in cardiac hypertrophy. Long noncoding RNAs (lncRNAs) are novel transcripts that function as gene regulators. However, it is unclear whether lncRNAs regulate autophagy in cardiac hypertrophy. Here, we identified a novel transcript named lncRNA Gm15834, which was upregulated in the transverse aortic constriction (TAC) model in vivo and the angiotensin-II (Ang-II)-induced cardiac hypertrophy model in vitro and was regulated by nuclear factor kappa B (NF-κB). Importantly, forced expression of lncRNA Gm15834 enhanced autophagic activity of cardiomyocytes and promoted myocardial hypertrophy, whereas silencing of lncRNA Gm15834 attenuated autophagy-induced myocardial hypertrophy. Mechanistically, we found that lncRNA Gm15834 could function as an endogenous sponge RNA of microRNA (miR)-30b-3p, which was downregulated in cardiac hypertrophy. Inhibition of miR-30b-3p enhanced cardiomyocyte autophagic activity and aggravated myocardial hypertrophy, whereas overexpression of miR-30b-3p suppressed autophagy-induced myocardial hypertrophy by targeting the downstream autophagy factor of unc-51-like kinase 1 (ULK1). Moreover, inhibition of lncRNA Gm15834 by adeno-associated virus carrying short hairpin RNA (shRNA) suppressed cardiomyocyte autophagic activity, improved cardiac function, and mitigated cardiac hypertrophy. Taken together, our study identified a novel regulatory axis encompassing lncRNA Gm15834/miR-30b-3p/ULK1/autophagy in cardiac hypertrophy, which may provide a potential therapy target for cardiac hypertrophy.

MiR-103 inhibiting cardiac hypertrophy through inactivation of myocardial cell autophagy via targeting TRPV3 channel in rat hearts.

Cardiac hypertrophy is a common pathological change frequently accompanied by chronic hypertension and myocardial infarction. Nevertheless, the pathophysiological mechanisms of cardiac hypertrophy have never been elucidated. Recent studies indicated that miR-103 expression was significantly decreased in heart failure patients. However, less is known about the role of miR-103 in cardiac hypertrophy. The present study was designed to investigate the relationship between miR-103 and the mechanism of pressure overload-induced cardiac hypertrophy. TRPV3 protein, cardiac hypertrophy marker proteins (BNP and ß-MHC) and autophagy associated proteins (Beclin-1 and LC3-II) were up-regulated, as well as, miR-103 expression and autophagy associated proteins (p62) were down-regulated in cardiac hypertrophy models in vivo and in vitro respectively. Further results indicated that silencing TRPV3 or forcing overexpression of miR-103 could dramatically inhibit cell surface area, relative fluorescence intensity of Ca2+ signal and the expressions of BNP, ß-MHC, Beclin-1 and LC3-II, but promote p62 expression. Moreover, TRPV3 protein was decreased in neonatal rat ventricular myocyte transfected with miR-103, but increased by AMO-103. Co-transfection of the miR-103 with the luciferase reporter vector into HEK293 cells caused a sharp decrease in luciferase activity compared with transfection of the luciferase vector alone. The miR-103-induced depression of luciferase activity was rescued by an AMO-103. These findings suggested that TRPV3 was a direct target of miR-103. In conclusion, miR-103 could attenuate cardiomyocyte hypertrophy partly by reducing cardiac autophagy activity through the targeted inhibition of TRPV3 signalling in the pressure-overloaded rat hearts.

Activation of transient receptor potential vanilloid 3 channel (TRPV3) aggravated pathological cardiac hypertrophy via calcineurin/NFATc3 pathway in rats.

Cardiac hypertrophy is a compensatory response to mechanical stimuli and neurohormonal factors, ultimately progresses to heart failure. The proteins of some transient receptor potential (TRP) channels, Ca2+ -permeable nonselective cation channel, are highly expressed in cardiomyocytes, and associated with the occurrence of cardiac hypertrophy. Transient receptor potential vanilloid 3 (TRPV3) is a member of TRP, however, the functional role of TRPV3 in cardiac hypertrophy remains unclear. TRPV3 was elevated in pathological cardiac hypertrophy, but not in swimming exercise-induced physiological cardiac hypertrophy in rats. TRPV3 expression was also increased in Ang II-induced cardiomyocyte hypertrophy in vitro, which was remarkably increased by carvacrol (a nonselective TRPV channel agonist), and reduced by ruthenium red (a nonselective TRPV channel antagonist). Interestingly, we found that activated TRPV3 in Ang II-induced cardiomyocyte hypertrophy was accompanied with increasing intracellular calcium concentration, promoting calcineurin, and phosphorylated CaMKII protein expression, and enhancing NFATc3 nuclear translocation. However, blocking or knockdown of TRPV3 could inhibit the expressions of calcineurin, phosphorylated CaMKII and NFATc3 protein by Western blot. In conclusion, the activation of TRPV3 aggravated pathological cardiac hypertrophy through calcineurin/NFATc3 signalling pathway and correlated with the protein expression levels of calcineurin, phosphorylated CaMKII and NFATc3, revealing that TRPV3 might be a potential therapeutic target for cardiac hypertrophy.

Neutrophil membrane-coated taurine nanoparticles protect against hepatic ischemia-reperfusion injury.

Hepatic ischemia-reperfusion (I/R) injury is a multifactorial process caused by transient tissue hypoxia and the following reoxygenation, commonly occurring in liver transplantation and hepatectomy. Hepatic I/R can induce a systemic inflammatory response, liver dysfunction, or even multiple organ failure. Although we have previously reported that taurine could attenuate acute liver injury after hepatic I/R, only a tiny proportion of the systemically injected taurine could reach the targeted organ and tissues. In this present study, we prepared taurine nanoparticles (Nano-taurine) by coating taurine with neutrophil membranes and investigated the protective effects of Nano-taurine against I/R-induced injury and the underlying mechanisms. Our results showed that Nano-taurine restored liver function by declining AST and ALT levels and reducing histology damage. Nano-taurine decreased inflammatory cytokines, including interleukin (IL)-6, tumor necrosis factor (TNF)-α, intercellular adhesion molecule (ICAM)-1, NLR pyrin domain containing 3 (NLRP3) and apoptosis-associated speck-like protein containing CARD (ASC) and oxidants including superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), catalase (CAT) and reactive oxygen species (ROS), exhibiting anti-inflammatory and antioxidant properties. The expression of solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) was increased, while prostaglandin-endoperoxide synthase 2 (Ptgs2) was decreased upon administration of Nano-taurine, suggesting that inhibiting ferroptosis may be involved in the mechanism during hepatic I/R injury. These results suggest that Nano-taurine have a targeted therapeutic effect on hepatic I/R injury by inhibiting inflammation, oxidative stress, and ferroptosis.

Super-enhancer-driven lncRNA Snhg7 aggravates cardiac hypertrophy via Tbx5/GLS2/ferroptosis axis.

Long non-coding RNAs (lncRNAs) are expressed aberrantly in cardiac disease, but their roles in cardiac hypertrophy are still unknown. Here we sought to identify a specific lncRNA and explore the mechanisms underlying lncRNA functions. Our results revealed that lncRNA Snhg7 was a super-enhancer-driven gene in cardiac hypertrophy by using chromatin immunoprecipitation sequencing (ChIP-seq). We next found that lncRNA Snhg7 induced ferroptosis by interacting with T-box transcription factor 5 (Tbx5), a cardiac transcription factor. Moreover, Tbx5 bound to the promoter of glutaminase 2 (GLS2) and regulated cardiomyocyte ferroptosis activity in cardiac hypertrophy. Importantly, extra-terminal domain inhibitor JQ1 could suppress super-enhancers in cardiac hypertrophy. Inhibition of lncRNA Snhg7 could block the expressions of Tbx5, GLS2 and levels of ferroptosis in cardiomyocytes. Furthermore, we verified that Nkx2-5 as a core transcription factor, directly bound the super-enhancer of itself and lncRNA Snhg7, increasing both of their activation. Collectively, we are the first to identify lncRNA Snhg7 as a novel functional lncRNA in cardiac hypertrophy, might regulate cardiac hypertrophy via ferroptosis. Mechanistically, lncRNA Snhg7 could transcriptionally regulate Tbx5/GLS2/ferroptosis in cardiomyocytes.

Upregulation of Hsp27 via further inhibition of histone H2A ubiquitination confers protection against myocardial ischemia/reperfusion injury by promoting glycolysis and enhancing mitochondrial function.

Research suggests that ischemic glycolysis improves myocardial tolerance to anoxia and low-flow ischemia. The rate of glycolysis during ischemia reflects the severity of the injury caused by ischemia and subsequent functional recovery following reperfusion. Histone H2AK119 ubiquitination (H2Aub) is a common modification that is primarily associated with gene silencing. Recent studies have demonstrated that H2Aub contributes to the development of cardiovascular diseases. However, the underlying mechanism remains unclear. This study identified Hsp27 (heat shock protein 27) as a H2Aub binding protein and explored its involvement in mediating glycolysis and mitochondrial function. Functional studies revealed that inhibition of PRC1 (polycomb repressive complex 1) decreased H2Aub occupancy and promoted Hsp27 expression through inhibiting ubiquitination. Additionally, it increased glycolysis by activating the NF-κB/PFKFB3 signaling pathway during myocardial ischemia. Furthermore, Hsp27 reduced mitochondrial ROS production by chaperoning COQ9, and suppressed ferroptosis during reperfusion. A delivery system was developed based on PCL-PEG-MAL (PPM)-PCM-SH (CWLSEAGPVVTVRALRGTGSW) to deliver PRT4165 (PRT), a potent inhibitor of PRC1, to damaged myocardium, resulting in decreased H2Aub. These findings revealed a novel epigenetic mechanism connecting glycolysis and ferroptosis in protecting the myocardium against ischemia/reperfusion injury.

Up-regulation of IRF3 is required for docosahexaenoic acid suppressing ferroptosis of cardiac microvascular endothelial cells in cardiac hypertrophy rat.

The molecular characteristics of ferroptosis in cardiac hypertrophy have been rarely studied. Especially, there have been no studies to investigate the regulatory mechanisms of docosahexaenoic acid (DHA) on ferroptosis in cardiac hypertrophy. This study was designed to determine the role of ferroptosis in microvascular injury, and investigate the contribution of DHA in suppressing ferroptosis and preventing pressure overload-mediated endothelial damage. Our results indicated that the expression of interferon regulating factor 3 (IRF3) was primarily inhibited by pressure overload and consequently caused endothelial ferroptosis. Nevertheless, administration of DHA increased IRF3 expression and provided a pro-survival advantage for the endothelial system in the context of pressure overload. Experimental studies clearly showed that inhibition of IRF3 down-regulated SLC7A11 expression, and the latter leaded to the increase in the activities of arachidonate 12-lipoxygenase, which obligated cardiac microvascular endothelial cells to undergo ferroptosis via augmenting lipid peroxides. Interestingly, DHA supplementation suppressed endothelial ferroptosis via up-regulation of IRF3. Taken together, our studies identified the IRF3-SLC7A11-arachidonate 12-lipoxygenase axis as a new pathway responsible for pressure overload-mediated microvascular damage via initiating endothelial ferroptosis. In contrast, DHA treatment up-regulated the expression of IRF3 and thus reduced cellular ferroptosis, conferring a protective advantage to the endothelial system in pressure overload. These findings revealed that targeting IRF3 might be a useful therapeutic strategy for cardioprotection in cardiac hypertrophy and heart failure.

Characterization and Validation of ceRNA-Mediated Pathway-Pathway Crosstalk Networks Across Eight Major Cardiovascular Diseases.

Pathway analysis is considered as an important strategy to reveal the underlying mechanisms of diseases. Pathways that are involved in crosstalk can regulate each other and co-regulate downstream biological processes. Furthermore, some genes in the pathways can function with other genes via the relationship of the competing endogenous RNA (ceRNA) mechanism, which has also been demonstrated to play key roles in cellular biology. However, the comprehensive analysis of ceRNA-mediated pathway crosstalk is lacking. Here, we constructed the landscape of the ceRNA-mediated pathway-pathway crosstalk of eight major cardiovascular diseases (CVDs) based on sequencing data from ∼2,800 samples. Some common features shared by numerous CVDs were uncovered. A fraction of the pathway-pathway crosstalk was conserved in multiple CVDs and a core pathway-pathway crosstalk network was identified, suggesting the similarity of pathway-pathway crosstalk among CVDs. Experimental evidence also demonstrated that the pathway crosstalk was functioned in CVDs. We split all hub pathways of each pathway-pathway crosstalk network into three categories, namely, common hubs, differential hubs, and specific hubs, which could highlight the common or specific biological mechanisms. Importantly, after a comparison analysis of the hub pathways of networks, ∼480 hub pathway-induced common modules were identified to exert functions in CVDs broadly. Moreover, we performed a random walk algorithm on the hub pathway-induced sub-network and identified 23 potentially novel CVD-related pathways. In summary, our study revealed the potential molecular regulatory mechanisms of ceRNA crosstalk in pathway-pathway crosstalk levels and provided a novel routine to investigate the pathway-pathway crosstalk in cardiology. All CVD pathway-pathway crosstalks are provided in http://www.licpathway.net/cepathway/index.html.

Neutrophil-like cell membrane-coated siRNA of lncRNA AABR07017145.1 therapy for cardiac hypertrophy via inhibiting ferroptosis of CMECs.

Cardiac microvascular dysfunction is associated with cardiac hypertrophy and can eventually lead to heart failure. Dysregulation of long non-coding RNAs (lncRNAs) has recently been recognized as one of the key mechanisms involved in cardiac hypertrophy. However, the potential roles and underlying mechanisms of lncRNAs in cardiac microvascular dysfunction have not been explicitly delineated. Our results confirmed that cardiac microvascular dysfunction was related to cardiac hypertrophy and ferroptosis of cardiac microvascular endothelial cells (CMECs) occurred during cardiac hypertrophy. Using a combination of in vivo and in vitro studies, we identified a lncRNA AABR07017145.1, named as lncRNA AAB for short, and revealed that lncRNA AAB was upregulated in the hearts of cardiac hypertrophy rats as well as in the Ang II-induced CMECs. Importantly, we found that lncRNA AAB sponged and sequestered miR-30b-5p to induce the imbalance of MMP9/TIMP1, which enhanced the activation of transferrin receptor 1 (TFR-1) and then eventually led to the ferroptosis of CMECs. Moreover, we have developed a delivery system based on neutrophil membrane (NM)-camouflaged mesoporous silica nanocomplex (MSN) for inhibition of cardiac hypertrophy, indicating the potential role of silenced lncRNA AAB (si-AAB) and overexpressed miR-30b-5p as the novel therapy for cardiac hypertrophy.

MSTN Attenuates Cardiac Hypertrophy through Inhibition of Excessive Cardiac Autophagy by Blocking AMPK /mTOR and miR-128/PPARγ/NF-κB.

Cardiac hypertrophy, a response of the heart to increased workload, is a major risk factor for heart failure. Myostatin (MSTN) is an inhibitor of myogenesis, regulating the number and size of skeletal myocytes. In recent years, cardiomyocyte autophagy also has been considered to be involved in controlling the hypertrophic response. However, less is known about the detailed mechanism of MSTN on cardiac hypertrophy via regulation of cardiomyocyte autophagy. In this study, we found that the deletion of MSTN potentiated abdominal aorta coarctation (AAC) and angiotensin II (Ang II)-induced pathological cardiac hypertrophy and cardiac autophagy; however, AAC and Ang II-induced cardiac hypertrophic phenotype and cardiac autophagy were dramatically diminished by MSTN in vivo and in vitro. Mechanistically, the anti-hypertrophic and anti-autophagic effects mediated by MSTN in response to pathological stimuli were associated with the direct inactivation of activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) and activation of the peroxisome proliferator-activated receptor gamma (PPARγ)/nuclear factor κB (NF-κB) signaling pathway. Additionally, miR-128 aggravated the progression of cardiac hypertrophy through suppressing its target PPARγ. Furthermore, MSTN downregulated miR-128 expression induced by AAC and Ang II. Taken together, MSTN significantly blunts pathological cardiac hypertrophy and dysfunction, at least in part, by inhibiting excessive cardiac autophagy via blocking AMPK/mTOR and miR-128/PPARγ/NF-κB signaling pathways.

Shear Stress Rescued the Neuronal Impairment Induced by Global Cerebral Ischemia Reperfusion via Activating PECAM-1-eNOS-NO Pathway.

Microvessel hypoperfusion following ischemic stress resulted in a decreased shear stress of brain microvascular endothelial cells (BMECs) and contributed to abnormal expression of PECAM-1 after global cerebral ischemia/reperfusion (I/R) injury. Here, we identified novel pathophysiologic and rehabilitative procedures specific to shear stress in microvascular endothelial cells in response to global cerebral I/R injury. We found that the decrease in cerebral blood flow of gerbils after global cerebral I/R injury reduces shear stress, and the abnormal change in shear stress leads to microvascular endothelial cell and neuron damage. Nevertheless, suitable high levels of shear stress contribute to rescuing the dysfunction and malformation of BMECs via regulating the PECAM-1-eNOS-NO pathway to enhance nitric oxide release, decrease the expression of caspase-3 to reduce apoptosis, and improve the shear-adaptability of endothelial cells, thereby playing a protective role in the gerbil brain.

Deletion of Neuropeptide Y Attenuates Cardiac Dysfunction and Apoptosis During Acute Myocardial Infarction.

Increasing neuropeptide Y (NPY) has been shown to be a risk factor for cardiovascular diseases. However, its role and mechanism in myocardial infarction (MI) have not yet been fully understood. H9c2 cells and neonatal rat ventricular myocytes with loss of function of NPY and rats with global knockout were used in this study. MI model of rats was induced by the ligation of left coronary artery, and the extent of MI was analyzed through echocardiographic, pathological, and molecular analyses. Our data demonstrated that NPY expression was significantly increased in MI rats and hypoxia/hydrogen peroxide (H2O2)-treated cardiomyocytes. At the same time, NPY-knockout rats exhibited a remarkable decrease in infarct size, serum lactate dehydrogenase activity, cardiomyocyte apoptosis, and caspase-3 expression and activity and a strong improvement in heart contractile function compared with MI rats. Meanwhile, NPY small interfering RNA (siRNA) inhibited the cell apoptosis in H2O2-treated H9c2 cells and hypoxia-treated neonatal rat ventricular myocytes. NPY deletion increased miR-499 expression and decreased FoxO4 expression in MI in vivo and in vitro. Moreover, NPY type 1 receptor antagonist BIBO3304 can reverse miR-499 decrease and FoxO4 increase in H2O2-induced cardiomyocytes. NPY siRNA inhibited cell apoptosis in H2O2-treated H9c2 cells that were reversed by miR-499 inhibitor. Additionally, FoxO4 was validated as the direct target of miR-499. Moreover, BIBO3304 and FoxO4 siRNA significantly increased the cell activity, inhibited the cell apoptosis, and decreased caspase-3 expression and activity in H2O2-treated cardiomyocytes that NPY presented the opposite effect. Collectively, deletion of NPY reduced myocardial ischemia, improved cardiac function, and inhibited cardiomyocyte apoptosis by NPY type 1 receptor-miR-499-FoxO4 axis, which provides a new treatment for MI.

The neuroprotective effects of carvacrol on ischemia/reperfusion-induced hippocampal neuronal impairment by ferroptosis mitigation.

OBJECTIVE: Cerebral ischemia is the most common type of neuronal injury and is characterized by a reduction in the function and number of hippocampal neurons. Carvacrol has a significant neuroprotective effect in cerebral ischemia. However, the mechanisms by which carvacrol affects cerebral ischemia, especially with respect to the regulation of neuronal damage by iron levels, have never been systematically studied. This study aimed to reveal the mechanisms by which carvacrol protects against hippocampal neuron impairment after ischemic stroke in gerbils. MATERIALS AND METHODS: The Morris water maze test was performed to evaluate learning and memory impairments. Iron ion content and oxidative stress index were detected by the kit. MTT assay was performed to assess the cell viability. The morphology and molecular characteristics were detected by electron micrographs and western blot. RESULTS: In the present study, we demonstrated the neuroprotective effects of carvacrol in vivo and in vitro. The Morris water maze test showed that the learning and memory abilities of the gerbils treated with carvacrol were significantly improved. Lipid peroxide injury was evaluated by measuring the levels of lipid peroxide biomarkers; the results indicated that carvacrol decreased the level of lipid peroxide in ischemic gerbil brain tissue. Histopathological examinations and western blotting were performed to evaluate injury in neurons, and carvacrol reduced cell death. Moreover, ferroptosis in the hippocampus was evaluated by measuring the levels of proteins involved in this iron-dependent form of regulated cell death. These results indicated that carvacrol reduced cell death and that carvacrol inhibited ferroptosis by increasing the expression of glutathione peroxidase 4(GPx4). This study showed that carvacrol may be a valuable drug for treating cerebral ischemia. CONCLUSION: Carvacrol provides protection for hippocampal neurons against I/R in gerbils by inhibiting ferroptosis through increasing the expression of GPx4.

Allicin attenuates pathological cardiac hypertrophy by inhibiting autophagy via activation of PI3K/Akt/mTOR and MAPK/ERK/mTOR signaling pathways.

BACKGROUND: Cardiac hypertrophy is an adaptive response of the myocardium to pressure or volume overload. Recent evidences indicate that allicin can prevent cardiac hypertrophy. However, it is not clear whether allicin alleviates cardiac hypertrophy by inhibiting autophagy. PURPOSE: We aimed to investigate the effects of allicin on pressure overload-induced cardiac hypertrophy, and further to clarify the related mechanism. STUDY DESIGN/METHODS: Cardiac hypertrophy was successfully established by abdominal aortic constriction (AAC) in rats, and cardiomyocytes hypertrophy was simulated by angiotensin II (Ang II) in vitro. Hemodynamic parameters were monitored by organism function experiment system in vivo. The changes of cell surface area were observed using HE and immunofluorescence staining in vivoand in vitro, respectively. The expressions of cardiac hypertrophy relative protein (BNP and ß-MHC), autophagy marker protein (LC3-II and Beclin-1), Akt, PI3K and ERK were detected by western blot. RESULTS: Allicin could improve cardiac function, and reduce cardiomyocytes size, and decrease BNP and ß-MHC protein expressions. Further results showed that allicin could lower LC3-II and Beclin-1 protein expressions both in vivo and in vitro experiments. And pharmacological inhibitor of mTOR, rapamycin could antagonize the effects of allicin on Ang II-induced cardiac hypertrophy and autophagy. Simultaneously, allicin could promote the expressions of p-Akt, p-PI3K and p-ERK protein. CONCLUSION: These findings reveal a novel mechanism of allicin attenuating cardiac hypertrophy which allicin could inhibit excessive autophagy via activating PI3K/Akt/mTOR and MAPK/ERK/mTOR signaling pathways.

DHA attenuates hepatic ischemia reperfusion injury by inhibiting pyroptosis and activating PI3K/Akt pathway.

Hepatic ischemia reperfusion (I/R) injury is very common in liver transplantation and major liver surgeries and may cause liver failure or even death. Docosahexaenoic acid (DHA) has displayed activities in reducing oxidative stress and inflammatory reaction in many disorders. In the present study, we investigated the protective effects of DHA against I/R-induced injury and the underlying mechanisms. Here, we show that DHA protected hepatic I/R injury by reducing aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and decreasing the oxidative stress in liver tissues. The viability of Buffalo rat liver (BRL) cells was reduced by hypoxia/restoration (H/R) but restored by DHA. DHA significantly downregulated the expression of pyroptosis-related proteins including NLR pyrin domain containing 3 (NLRP3), apoptotic speck-like protein containing CARD (ASC) and cleaved caspase-1 and reduced the secretion of pro-inflammatory cytokines. The above results were supported by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. However, incubation with LY294002, a specific inhibitor of phosphatidylinositol-3-kinase (PI3K), abolished the effects of DHA, since it increased the expression of cleaved caspase-1 and the production of inflammatory cytokines. The present results have demonstrated that DHA ameliorated I/R-induced injury by inhibiting pyroptosis of hepatocytes induced in liver I/R injury in vivo and in vitro through the PI3K/Akt pathway, providing a potential therapeutic option to prevent liver injury by I/R.

Allicin improves the function of cardiac microvascular endothelial cells by increasing PECAM-1 in rats with cardiac hypertrophy.

OBJECTIVE: Cardiac microvascular damage is significantly associated with the development of cardiac hypertrophy (CH). Researchers found that allicin could inhibit CH, but the relationship between cardiac microvessel and the inhibition of allicin on CH has not been reported. We aimed to investigate the effect of allicin on the function of cardiac microvascular endothelial cells (CMECs) in CH rat. MATERIALS AND METHODS: The hemodynamic parameters were measured by BL-420F biological function experimental system and the indicators of the ventricular structure and function were measured by echocardiographic system. MTT assay was performed to assess the cell viability. Nitrite detection was performed to detect nitric oxide content. The morphology and molecular characteristics were detected by electron micrographs, immunofluorescence, quantitative real-time polymerase chain reaction (qRT-PCR), western blot. Wound healing experiment, analysis of tube formation and shear adaptation were performed to assess CMECs migration ability, angiogenesis and shear-responsiveness respectively. RESULT: Our findings have identified that microvascular density was decreased by observing the expression of platelet endothelial cell adhesion molecule-1 (PECAM-1) in CH rats. Interestingly, allicin improved the distribution and expression of PECAM-1. Meanwhile, allicin enhanced the migration and angiogenesis ability of CMECs, activated PECAM-1-PI3K-AKT-eNOS signaling pathway, however, the role of allicin was disappear after PECAM-1 was silenced. Allicin decreased the expression of caspase-3 and receptor interacting protein 3 (RIP3), inhibited necroptosis, and increased the levels of Angiopoietin-2 (Ang-2) and platelet-derived growth factor receptor-ß (PDGFR-ß). Under 10 dyn/cm2 condition, allicin advanced the modification ability of CMECs's shear-adaptation by activating PECAM-1. CONCLUSION: Allicin provided cardioprotection for CH rats by improving the function of CMECs through increasing the expression of PECAM-1.

The transient receptor potential vanilloid-3 regulates hypoxia-mediated pulmonary artery smooth muscle cells proliferation via PI3K/AKT signaling pathway.

OBJECTVES: Transient receptor potential vanilloid 3 (TRPV3) is a member of the TRP channels family of Ca2+ -permeant cation channels. In this study, we aim to investigate the role of TRPV3 in pulmonary vascular remodeling and PASMCs proliferation under hypoxia. MATERIALS AND METHODS: The expression of TRPV3 was evaluated in patients with pulmonary arterial hypertension (PAH) and hypoxic rats, using hematoxylin and eosin (H&E) and immunohistochemistry. In vitro, MTT assay, flow cytometry, Western blotting and immunofluorescence were performed to investigate the effects of TRPV3 on proliferation of PASMCs. RESULTS: We found that, in vivo, the expression of TRPV3 was increased in patients with PAH and hypoxic rats. Right ventricular hypertrophy measurements and pulmonary pathomorphology data show that the ratio of the heart weight/tibia length (HW/TL), the right ventricle/left ventricle plus septum (RV/LV+S) and the medial width of the pulmonary artery were increased in chronic hypoxic rats. Moreover, the expression of proliferating cell nuclear antigen (PCNA), Cyclin D, Cyclin E and Cyclin A, phospho-CaMKII (p-CaMKII) were induced by hypoxia. In vitro, we revealed that hypoxia promoted PASMCs viability, increased the expression of PCNA, Cyclin D, Cyclin E, Cyclin A p-CaMKII, made more cells from G0 /G1 phase to G2 /M + S phase, enhanced the microtubule formation, and increased [Ca2+ ]i , which could be suppressed by Ruthenium Red, an inhibitor of TRPV3, and TRPV3 silencing has similar effects. Furthermore, the up-regulated expression of PCNA, Cyclin D, Cyclin E and Cyclin A, the increased number of cells in G2 /M and S phase, and the enhanced activation and expression of PI3K and AKT proteins induced by hypoxia and in presence of carvacrol (an agonist of TRPV3), was significantly attenuated by incubation of LY 294002, a specific inhibitor for PI3K/AKT. CONCLUSIONS: These findings suggest that TRPV3 is involved in hypoxia-induced pulmonary vascular remodeling and promotes proliferation of PASMCs and the effect is, at least in part, mediated via the PI3K/AKT pathway.

Transient receptor potential vanilloid-3 (TRPV3) activation plays a central role in cardiac fibrosis induced by pressure overload in rats via TGF-ß1 pathway.

Cardiac fibrosis is a common pathologic change along with pressure overload. Recent studies indicated that transient receptor potential (TRP) channels played multiple roles in heart. However, the functional role of transient receptor potential vanilloid-3 (TRPV3) in cardiac fibrosis remained unclear. The present study was designed to investigate the relationship between TRPV3 activation and pressure overload-induced cardiac fibrosis. Pressure overload rats were successfully established by abdominal aortic constriction (AAC), and cardiac fibrosis was simulated by 100 nM angiotensin II (Ang II) in neonatal cardiac fibroblasts. Echocardiographic parameters, cardiac fibroblast proliferation, cell cycle, intracellular calcium concentration ([Ca2+] i ), and the protein expressions of collagen I, collagen III, transforming growth factor beta 1 (TGF-ß1), cyclin E, and cyclin-dependent kinase 2 (CDK2) were measured. Echocardiographic and histological measurements suggested that the activation of TRPV3 exacerbated the cardiac dysfunction and increased interstitial fibrosis in pressure overload rats. Further results showed that TRPV3 activation upregulated the expressions of collagen I, collagen III, TGF-ß1, cyclin E, and CDK2 in vivo and in vitro. At the same time, blocking TGF-ß1 pathway could partially reverse the effect of TRPV3 activation. These results suggested that TRPV3 activation exacerbated cardiac fibrosis by promoting cardiac fibroblast proliferation through TGF-ß1/CDK2/cyclin E pathway in the pressure-overloaded rat hearts.

Activation of AMPK Attenuated Cardiac Fibrosis by Inhibiting CDK2 via p21/p27 and miR-29 Family Pathways in Rats.

Cardiac fibrosis is pathological damage associated with nearly all forms of heart disease. AMP-activated protein kinase (AMPK) is an evolutionary conserved energy-sensing enzyme. Emerging evidences indicate that AMPK plays an important role in cardiac fibrosis and cell proliferation. However, less is known about the detailed mechanism of AMPK activation on cardiac fibrosis. In this study, we found the AMPK activation improved the impaired cardiac function of cardiac fibrosis rats and decreased interstitial fibrosis. Further results indicated AMPK activation promoted p21 and p27 and inhibited CDK2 and cyclin E protein expressions both in vivo and in vitro. Moreover, AMPK activation repressed downstream transcription factor hepatocyte nuclear factor 4 alpha (HNF-4α) expression and decreased the binding of HNF-4α to TGF-ß1 promoters, which eventually resulted in TGF-ß1 downregulation and miR-29 family upregulation. Furthermore, miR-29, in turn, inhibited the progression of cardiac fibrosis through suppressing its target CDK2. Taken together, activation of AMPK, on the one hand, upregulated p21 and p27 expression, further inhibited CDK2 and cyclin E complex, and finally suppressed the progression of cardiac fibrosis, and, on the other hand, repressed HNF-4α expression, further downregulated the activity of TGF-ß1 promoter, promoted miR-29 expression, and finally prevented the development of cardiac fibrosis.