Although natural sources have long been exploited for astaxanthin production, it is still uncertain if natural astaxanthin can be produced at lower cost than that of synthetic astaxanthin or not. In ...order to give a comprehensive cost analysis of astaxanthin production from Haematococcus, a pilot plant with two large scale outdoor photobioreactors and a raceway pond was established and operated for 2years to develop processes for astaxanthin production from Haematococcus. The developed processes were scaled up to a hypothetical plant with a production capacity about 900kg astaxanthin per year, and the process economics was preliminarily assessed. Based on the analysis, the production cost of astaxanthin and microalgae biomass can be as low as $718/kg and $18/kg respectively. The results are very encouraging because the estimated cost might be lower than that of chemically synthesized astaxanthin.
The expression and function of long noncoding RNAs (lncRNAs) in the development of hypoxic pulmonary hypertension (HPH), especially in the proliferation of pulmonary artery smooth muscle cells ...(PASMCs), are largely unknown. Herein, we examined the expression and role of lncRNA-maternally expressed gene 3 (lncRNA-MEG3) in HPH. lncRNA-MEG3 was significantly increased and primarily localized in the cytoplasm of hypoxic PASMCs. lncRNA-MEG3 knockdown by lung-specific delivery of small interfering RNAs (siRNAs) significantly inhibited the development of HPH in vivo. Silencing of lncRNA-MEG3 by siRNAs and gapmers attenuated proliferation and cell-cycle progression in both PASMCs from idiopathic pulmonary arterial hypertension (iPAH) patients (iPAH-PASMCs) and hypoxia-exposed PASMCs in vitro. Mechanistically, we found that lncRNA-MEG3 interacts with and leads to the degradation of microRNA-328-3p (miR-328-3p), leading to upregulation of insulin-like growth factor 1 receptor (IGF1R). Additionally, higher expression of lncRNA-MEG3 and IGF1R and lower expression of miR-328-3p were observed in iPAH-PASMCs and relevant HPH models. These data provide insights into the contribution of lncRNA-MEG3 to HPH. Upregulation of lncRNA-MEG3 sequesters cytoplasmic miR-328-3p, eventually leading to expression of IGF1R, revealing a regulatory mechanism by lncRNAs in hypoxia-induced PASMC proliferation.
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Increasing evidence indicates that lncRNAs are implicated in pulmonary hypertension. Xing et al. demonstrate that lncRNA-MEG3 contributes to PASMCs proliferation and cell-cycle progression through interacting with and facilitating miR-328-3p degradation. Lung-specific lncRNA-MEG3 knockdown rescues hypoxia-induced pulmonary hypertension, which is prevented by anti-miR-328-3p therapy.
Necrosis with inflammation plays a crucial role in acute respiratory distress syndrome (ARDS). Receptor-interacting protein 3 (RIPK3) regulates a newly discovered programmed form of necrosis called ...necroptosis. However, the underlying mechanism of necroptosis in ARDS remains unknown. Thus, the purpose of this study was to examine the possible involvement of RIPK3 in ARDS-associated necroptosis. RIPK3 protein levels were found to be significantly elevated in the plasma and bronchoalveolar lavage fluid of ARDS patients. Next, we utilised a mouse model of severe ARDS induced with high-dose lipopolysaccharide and found that lung injury was mainly due to RIPK3-mixed lineage kinase domain-like pseudokinase (MLKL)-mediated necroptosis and endothelial dysfunction. The activation of RIPK3-MLKL by tumour necrosis factor receptor 1 (TNFR1) and TNFR1-associated death domain protein (TRADD) required catalytically active RIPK1 and the inhibition of Fas-associated protein with death domain (FADD)/caspase-8 catalytic activity. We further showed that the molecular chaperone heat shock protein 90 (Hsp90)/p23, as a novel RIPK3- and MLKL-interacting complex, played an important role in RIP-MLKL-mediated necroptosis, inflammation and endothelial dysfunction in the pulmonary vasculature, which resulted in ARDS. Collectively, the results of our study indicate that necroptosis is an important mechanism of cell death in ARDS and the inhibition of necroptosis may be a therapeutic intervention for ARDS.
Key messages
Lung injury in high-dose LPS-induced severe ARDS is mainly due to RIP3-MLKL-mediated necroptosis and endothelial dysfunction.
Chaperone HSP90/p23 is a novel RIP3- and MLKL-interacting complex in HPAECs.
HSP90/p23 is a novel RIP3- and MLKL-interacting complex in RIP-MLKL-mediated necroptosis, inflammation and endothelial dysfunction.
Abstract
Background
Pyroptosis is a form of programmed cell death involved in the pathophysiological progression of hypoxic pulmonary hypertension (HPH). Emerging evidence suggests that ...N6-methyladenosine (m6A)-modified transcripts of long noncoding RNAs (lncRNAs) are important regulators that participate in many diseases. However, whether m6A modified transcripts of lncRNAs can regulate pyroptosis in HPH progression remains unexplored.
Methods
The expression levels of FENDRR in hypoxic pulmonary artery endothelial cells (HPAECs) were detected by using quantitative real-time polymerase chain reaction (qRT-PCR) and fluorescence in situ hybridization (FISH). Western blot, Lactate dehydrogenase (LDH) release assay, Annexin V-FITC/PI double staining, Hoechst 33342/PI fluorescence staining and Caspase-1 activity assay were used to detect the role of FENDRR in HPAEC pyroptosis. The relationship between FENDRR and dynamin-related protein 1 (DRP1) was explored using bioinformatics analysis, Chromatin Isolation by RNA Purification (CHIRP), Electrophoretic mobility shift assay (EMSA) and Methylation-Specific PCR (MSP) assays. RNA immunoprecipitation (RIP) and m6A dot blot were used to detect the m6A modification levels of FENDRR. A hypoxia-induced mouse model of pulmonary hypertension (PH) was used to test preventive effect of conserved fragment TFO2 of FENDRR.
Results
We found that FENDRR was significantly downregulated in the nucleus of hypoxic HPAECs. FENDRR overexpression inhibited hypoxia-induced HPAEC pyroptosis. Additionally, DRP1 is a downstream target gene of FENDRR, and FENDRR formed an RNA–DNA triplex with the promoter of DRP1, which led to an increase in DRP1 promoter methylation that decreased the transcriptional level of DRP1. Notably, we illustrated that the m6A reader YTHDC1 plays an important role in m6A-modified FENDRR degradation. Additionally, conserved fragment TFO2 of FENDEE overexpression prevented HPH in vivo.
Conclusion
In summary, our results demonstrated that m6A-induced decay of FENDRR promotes HPAEC pyroptosis by regulating DRP1 promoter methylation and thereby provides a novel potential target for HPH therapy.
Pulmonary arterial hypertension (PAH) is defined as elevation of mean pulmonary arterial pressure to ≥25 mmHg within the low pressure pulmonary circulatory system. PAH is characterized by obstructive ...vascular remodeling, partially due to excessive pulmonary arterial smooth muscle cell (PASMC) proliferation. Puerarin is a natural flavonoid isolated from the herb Radix puerariae, which has been widely used for the treatment of cardiovascular and cerebrovascular disorders and diabetes. However, how puerarin mediates autophagy in the progression of pulmonary vascular remodeling is unclear. In this study, we explored the effects of puerarin in a hypoxic pulmonary hypertension (PH) rat model using immunohistochemistry, and morphometric analyses of right ventricle. In addition, cell counting kit 8 assay, western blotting and flow cytometry were employed to test cell proliferation in PASMCs, and then autophagy was tested with mRFP-GFP-LC3 fluorescence microscopy and Western blot. We found that puerarin could alleviate hypoxia-induced PH in rats and improved pulmonary histopathology, and also reduced the expression of autophagy markers in vivo and in vitro. Moreover, puerarin also ameliorated hypoxia-induced PASMC proliferation in an autophagy-dependent manner. Overall, these findings demonstrated that puerarin could prevent hypoxia-induced PH in rats, possibly via reducing autophagy and suppressing cell proliferation.
MiR-92b-3p has been shown to take part in several disease by regulate proliferation, apoptosis, differentiation and metastasis. However, the role of miR-92b-3p in pulmonary arterial hypertension ...(PAH) has not been illustrated clearly. Here, we found the level of miR-92b-3p which mainly located in the smooth muscle layer was down-regulation under hypoxic condition. It can inhibit pulmonary artery smooth muscle cells (PASMCs) proliferation and cell cycle progression. Through luciferase assay, miR-92b-3p bound to the 3′-UTR of USP28. we found that there was a significant negative relation between the level of miR-92b-3p and USP28 at protein level and reversed the down regulation of miR-92b-3p by hypoxia can suppress the proliferation of pulmonary artery smooth muscle cells by targeting USP28. These results suggested that miR-92b-3p acted a potential proliferation regulator in PASMCs and it maybe a novel treatment target of PAH.
•miR-92b-3p reverse the proliferaton of pulmonary artery smooth muscle cells under hypoxia condition.•miR-92b-3p regulate the protein level of USP28.•miR-92b-3p maybe a novel treatment target of pulmonary hypertension.
Ovarian cancer is the most fatal primary malignancy among gynecological cancers. Circular RNAs (circRNAs) play an important role in the development of various cancers, but the functions of circRNAs ...in ovarian cancer development have not been studied. We aim to explore the function and mechanism of CDR1as in the progression of ovarian cancer and to provide a new target for the diagnosis and treatment of ovarian cancer.
Ovarian cancer cell proliferation was assessed according to proliferating cell nuclear antigen (PCNA) and Ki67 protein expression levels and MTT and CCK8 assays. The migration ability of cells was detected by scratch-wound assays, and the invasion ability of the cells was determined by Transwell
assays. qRT-PCR and Western blotting were used to verify miRNA and protein expression.
CDR1as expression in ovarian tissues was significantly lower in ovarian cancer patients than in patients without ovarian cancer. CDR1as overexpression inhibited the proliferation, invasion and migration of ovarian cancer cells. Silencing CDR1as increased the expression of miR-135b-5p and decreased the expression of hypoxia-inducible factor 1-alpha inhibitor (HIF1AN), thus increasing the proliferation capacity of ovarian cancer cells.
CDR1as, acting as a sponge of miR-135b-5p, promotes the expression of HIF1AN and therefore plays a role in tumor inhibition.
Pulmonary arterial hypertension (PAH) is a progressive disease, characterized by a persistent elevation of pulmonary arterial pressure and pulmonary vascular remodelling. Recent studies implicated ...that long noncoding RNAs (lncRNAs) play important roles in the development of various diseases. However, the underlying mechanisms of lncRNAs in PAH remain unclear. Here we show evidence for the modulation of human pulmonary smooth muscle cell (HPASMC) proliferation and vascular remodelling by lncRNA taurine upregulated gene1 (TUG1).
TUG1 expression and localization was detected by real-time polymerase chain reaction (PCR) and fluorescence in situ hybridization. Proliferation and apoptosis were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), western blot, bromodeoxyuridine incorporation, flow cytometry, scratch-wound assay, 4′,6-diamidino-2-phenylindole (DAPI), and caspase-3 activity. Luciferase activity and microscale thermophoresis were used to identify biomolecular interactions. The right ventricular systolic pressure and right ventricular hypertrophy were measured to evaluate cardiopulmonary function.
TUG1 was upregulated in the pulmonary arteries of mice after a hypoxic assault and showed a significant increase in patients with PAH. TUG1 knockdown significantly prevented the development of PAH in vivo. Moreover, TUG1 promoted the proliferative responses of HPASMCs, including cell viability, 5-bromodeoxyuridine incorporation, the expression of proliferating cell nuclear antigen, and cell-cycle progression. All these functions of TUG1 were likely to be associated with miR-328.
The present study indicates that TUG1, a novel potential target for the treatment of PAH, is necessary for HPASMC proliferation and pulmonary vascular remodelling.
L’hypertension artérielle pulmonaire est une maladie évolutive, caractérisée par une élévation persistante de la pression artérielle pulmonaire et par un remodelage vasculaire pulmonaire. Les résultats d’études récentes semblent indiquer que les ARN longs non codants (ARNlnc) jouent un rôle important dans l’apparition de diverses maladies, mais les mécanismes sous-jacents de ces ARNlnc qui interviennent dans l’hypertension artérielle pulmonaire demeurent mal compris. Nous présentons ici des données à l’appui de la modulation de la prolifération des cellules musculaires lisses pulmonaires humaines et du remodelage vasculaire par l’ARNlnc TUG1 (taurine upregulated gene 1).
L’expression et l’emplacement de TUG1 ont été détectés par réaction de polymérisation en chaîne (PCR) en temps réel et par hybridation in situ en fluorescence. La prolifération et l’apoptose ont été mesurées de différentes manières : dosage par diméthylthiazolyl-diphényltétrazolium (MTT), buvardage de Western, incorporation de bromodésoxyuridine, cytométrie en flux, test de migration cellulaire par blessure, diamidino-phénylindole (DAPI) et activité de la caspase 3. Les interactions biomoléculaires ont été déterminées par la mesure de l’activité de la luciférase et par thermophorèse à micro-échelle. La pression systolique du ventricule droit et l’hypertrophie ventriculaire droite ont été mesurées afin d’évaluer la fonction cardiopulmonaire.
L’ARNlnc TUG1 a subi une régulation positive dans les artères pulmonaires de souris après provocation hypoxique et affichait une hausse importante chez les patients atteints d’hypertension artérielle pulmonaire. Le silençage de TUG1 a fortement inhibé l’apparition de l’hypertension artérielle pulmonaire in vivo. En outre, la présence de TUG1 a favorisé la réponse proliférative des cellules musculaires lisses pulmonaires humaines (y compris la viabilité des cellules), l’incorporation de 5-bromodésoxyuridine, l’expression de l’antigène nucléaire de prolifération cellulaire et la progression du cycle cellulaire. Toutes ces fonctions de TUG1 étaient vraisemblablement associées au microARN miR-328.
Les résultats de l’étude indiquent que l’ARNlnc TUG1, une nouvelle cible potentielle pour le traitement de l’hypertension artérielle pulmonaire, est nécessaire à la prolifération des cellules musculaires lisses pulmonaires humaines et au remodelage vasculaire pulmonaire.
Chronic hypoxia is the most common cause of secondary pulmonary hypertension, for which the mechanisms are still unclear. Recent studies implicated an important role for microRNAs (miRNAs) in ...hypoxia-mediated responses in various cellular processes, including cell apoptosis and proliferation. Therefore, we hypothesized that these regulatory molecules might be implicated in the etiology of hypoxic pulmonary hypertension. Here we show that miRNA-328, a posttranscriptional regulator, was drastically downregulated in the pulmonary artery (PA) after a hypoxic assault. PA rings, Western blot, quantitative real-time PCR, in situ hybridization, and luciferase assay were used to investigate the role of miRNA-328 in hypoxic pulmonary hypertension. We found that hypoxia produced a significant inhibition of miRNA-328 expression, which was involved in PA vasoconstriction and remodeling. Overexpressing miRNA-328 in the transgenic mice remarkably decreased the right ventricular systolic pressure and PA wall thickness under both normoxia and hypoxia. MiRNA-328 inhibited L-type calcium channel-α1C expression through a miRNA-328 binding site within the 3' untranslational region of L-type calcium channel-α1C. The L-type calcium channel-α1C inhibition attenuated the PA response to KCl. Furthermore, miRNA-328 suppressed the insulin growth factor 1 receptor, ultimately leading to apoptosis of pulmonary arterial smooth muscle cells. The posttranscriptional repression of L-type calcium channel-α1C and insulin growth factor 1 receptor was further confirmed by luciferase reporter assay. These results showed that miRNA-328, an important protecting factor, plays a significant role in PA constriction and remodeling by regulating multiple gene targets in hypoxic pulmonary hypertension.
Emerging evidence has suggested that circular RNAs (circRNAs) are involved in multiple physiological processes and participate in a variety of human diseases. However, the underlying biological ...function of circRNAs in pulmonary hypertension (PH) is still ambiguous. Herein, we investigated the implication and regulatory effect of a typical circRNA, CDR1as, in the pathological process of vascular calcification in PH. Human pulmonary artery smooth muscle cell (HPASMC) calcification was analyzed by western blotting, immunofluorescence, alizarin red S staining, alkaline phosphatase activity analysis, and calcium deposition quantification. CDR1as targets were identified by bioinformatics analysis and validated by dual-luciferase reporter and RNA antisense purification assays. We identified that CDR1as was upregulated in hypoxic conditions and promoted a phenotypic switch of HPASMCs from a contractile to an osteogenic phenotype. Moreover, microRNA (miR)-7-5p was shown to be a target of CDR1as, and calcium/calmodulin-dependent kinase II-delta (CAMK2D) and calponin 3 (CNN3) were suggested to be the putative target genes and regulated by CDR1as/miR-7-5p. The results showed that the CDR1as/miR-7-5p/CNN3 and CAMK2D regulatory axis mediates HPASMC osteoblastic differentiation and calcification induced by hypoxia. This evidence reveals an approach to the treatment of PH.
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Zhu and colleagues investigate the implication of circular RNA CDR1as in the pathological process of pulmonary hypertension. miR-7-5p is shown to be a target of CDR1as. Moreover, CAMK2D and CNN3 are regulated by CDR1as and miR-7-5p and play an important role in mediating vascular calcification in pulmonary hypertension.
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