RESUMEN
Vault RNAs (vtRNAs) are small noncoding RNAs and highly expressed in many eukaryotes. Here, we identified vtRNA2-1 as a novel regulator of the intestinal barrier via interaction with RNA-binding protein HuR. Intestinal mucosal tissues from patients with inflammatory bowel diseases and from mice with colitis or sepsis express increased levels of vtRNAs relative to controls. Ectopically expressed vtRNA2-1 decreases the levels of intercellular junction (IJ) proteins claudin 1, occludin, and E-cadherin and causes intestinal epithelial barrier dysfunction in vitro, whereas vtRNA2-1 silencing promotes barrier function. Increased vtRNA2-1 also decreases IJs in intestinal organoid, inhibits epithelial renewal, and causes Paneth cell defects ex vivo. Elevating the levels of tissue vtRNA2-1 in the intestinal mucosa increases the vulnerability of the gut barrier to septic stress in mice. vtRNA2-1 interacts with HuR and prevents HuR binding to claudin 1 and occludin mRNAs, thus decreasing their translation. These results indicate that vtRNA2-1 impairs intestinal barrier function by repressing HuR-facilitated translation of claudin 1 and occludin.
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Colitis , MicroARNs , Células de Paneth , Animales , Ratones , Claudina-1/genética , Claudina-1/metabolismo , Colitis/genética , Colitis/metabolismo , Mucosa Intestinal/metabolismo , Ocludina/metabolismo , MicroARNs/metabolismoRESUMEN
Paneth cells at the bottom of small intestinal crypts secrete antimicrobial peptides, enzymes, and growth factors and contribute to pathogen clearance and maintenance of the stem cell niche. Loss of Paneth cells and their dysfunction occur commonly in various pathologies, but the mechanism underlying the control of Paneth cell function remains largely unknown. Here we identified microRNA-195 (miR-195) as a repressor of Paneth cell development and activity by altering SOX9 translation via interaction with RNA-binding protein HuR. Tissue-specific transgenic expression of miR-195 (miR195-Tg) in the intestinal epithelium decreased the levels of mucosal SOX9 and reduced the numbers of lysozyme-positive (Paneth) cells in mice. Ectopically expressed SOX9 in the intestinal organoids derived from miR-195-Tg mice restored Paneth cell development ex vivo. miR-195 did not bind to Sox9 mRNA but it directly interacted with HuR and prevented HuR binding to Sox9 mRNA, thus inhibiting SOX9 translation. Intestinal mucosa from mice that harbored both Sox9 transgene and ablation of the HuR locus exhibited lower levels of SOX9 protein and Paneth cell numbers than those observed in miR-195-Tg mice. Inhibition of miR-195 activity by its specific antagomir improved Paneth cell function in HuR-deficient intestinal organoids. These results indicate that interaction of miR-195 with HuR regulates Paneth cell function by altering SOX9 translation in the small intestinal epithelium.
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Intestinal epithelial barrier defects occur commonly during a variety of pathological conditions, though their underlying mechanisms are not completely understood. Sphingosine-1-phosphate (S1P) has been shown to be a critical regulator of proliferation and of maintenance of an intact intestinal epithelial barrier, as is also sphingosine kinase 1 (SphK1), the rate-limiting enzyme for S1P synthesis. SphK1 has been shown to modulate its effect on intestinal epithelial proliferation through increased levels of c-myc. We conducted genome-wide profile analysis to search for differential microRNA expression related to overexpressed SphK1 demonstrating adjusted expression of microRNA 542-5p (miR-542-5p). Here, we show that miR-542-5p is regulated by SphK1 activity and is an effector of c-myc translation that ultimately serves as a critical regulator of the intestinal epithelial barrier. miR-542-5p directly regulates c-myc translation through direct binding to the c-myc mRNA. Exogenous S1P analogs administered in vivo protect murine intestinal barrier from damage due to mesenteric ischemia reperfusion, and damaged intestinal tissue had increased levels of miR-542-5p. These results indicate that miR-542-5p plays a critical role in the regulation of S1P-mediated intestinal barrier function, and may highlight a novel role in potential therapies.
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Intestinos , MicroARNs , Animales , Ratones , Proliferación Celular/genética , Células Epiteliales/metabolismo , Lisofosfolípidos/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , EsfingosinaRESUMEN
Gut barrier dysfunction occurs commonly in patients with critical disorders, leading to the translocation of luminal toxic substances and bacteria to the bloodstream. Connexin 43 (Cx43) acts as a gap junction protein and is crucial for intercellular communication and the diffusion of nutrients. The levels of cellular Cx43 are tightly regulated by multiple factors, including polyamines, but the exact mechanism underlying the control of Cx43 expression remains largely unknown. The RNA-binding protein HuR regulates the stability and translation of target mRNAs and is involved in many aspects of intestinal epithelial pathobiology. Here we show that HuR directly bound to Cx43 mRNA via its 3'-untranslated region in intestinal epithelial cells (IECs) and this interaction enhanced Cx43 expression by stabilizing Cx43 mRNA. Depletion of cellular polyamines inhibited the [HuR/Cx43 mRNA] complex and decreased the level of Cx43 protein by destabilizing its mRNA, but these changes were prevented by ectopic overexpression of HuR. Polyamine depletion caused intestinal epithelial barrier dysfunction, which was reversed by ectopic Cx43 overexpression. Moreover, overexpression of checkpoint kinase 2 in polyamine-deficient cells increased the [HuR/Cx43 mRNA] complex, elevated Cx43 levels, and promoted barrier function. These findings indicate that Cx43 mRNA is a novel target of HuR in IECs and that polyamines regulate Cx43 mRNA stability via HuR, thus playing a critical role in the maintenance of intestinal epithelial barrier function.NEW & NOTEWORTHY The current study shows that polyamines stabilize the Cx43 mRNA via HuR, thus enhancing the function of the Cx43-mediated gap junction. These findings suggest that induced Cx43 by HuR plays a critical role in the process by which polyamines regulate intestinal epithelial barrier.
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Conexina 43 , Proteína 1 Similar a ELAV , Poliaminas , ARN Mensajero , Humanos , Conexina 43/genética , Conexina 43/metabolismo , Proteína 1 Similar a ELAV/genética , Proteína 1 Similar a ELAV/metabolismo , Mucosa Intestinal/metabolismo , Poliaminas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Estabilidad del ARNRESUMEN
BACKGROUND: Findings on the association of statin use with delirium risk are inconsistent. THE STUDY QUESTION: Is statin use associated with delirium risk? STUDY DESIGN: We searched PubMed, the Cochrane Library, and the EMBASE database, limiting the search to human patients and articles in English published until December 31, 2021. The effect size and 95% confidence interval (CI) were defined as the odds ratio (OR) and 95% CI, respectively, to indicate the difference in the incidence of delirium between statin use and nonuse groups. A random-effects model was selected in the case of high heterogeneity of study populations. We used funnel plots, Egger test, Duval and Tweedie trim-and-fill approach, and the classic fail-safe N to assess publication bias. RESULTS: Of a total of 264 identified studies, 13 were selected for the qualitative review-4 RCTs and 9 observational cohort studies. Statin use was not associated with low delirium risk (pooled OR, 0·82; 95% CI, 0·64-1·04; P = 0·09). Substantial statistical heterogeneity was observed ( I2 , 90%). Visual inspection of the funnel plot of ORs from the studies revealed symmetry. Using the Grading of Recommendations Assessment, Development, and Evaluation approach, we assigned the evidence a rating of C and a weak recommendation for this review. CONCLUSIONS: Statin use is not associated with delirium risk. More comprehensive RCTs are required to confirm the results.
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Delirio , Inhibidores de Hidroximetilglutaril-CoA Reductasas , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/efectos adversos , Incidencia , Oportunidad Relativa , Delirio/inducido químicamente , Delirio/epidemiología , Delirio/prevención & controlRESUMEN
Early gut epithelial restitution reseals superficial wounds after acute injury, but the exact mechanism underlying this rapid mucosal repair remains largely unknown. MicroRNA-195 (miR-195) is highly expressed in the gut epithelium and involved in many aspects of mucosal pathobiology. Actin-related proteins (ARPs) are key components essential for stimulation of actin polymerization and regulate cell motility. Here, we reported that miR-195 modulates early intestinal epithelial restitution by altering ARP-2 expression at the translation level. miR-195 directly interacted with the ARP-2 mRNA, and ectopically expressed miR-195 decreased ARP-2 protein without effect on its mRNA content. In contrast, miR-195 silencing by transfection with anti-miR-195 oligo increased ARP-2 expression. Decreased ARP-2 levels by miR-195 overexpression were associated with an inhibition of early epithelial restitution, as indicated by a decrease in cell migration over the wounded area. Elevation of cellular ARP-2 levels by transfection with its transgene restored cell migration after wounding in cells overexpressing miR-195. Polyamines were found to decrease miR-195 abundance and enhanced ARP-2 translation, thus promoting epithelial restitution after wounding. Moreover, increasing the levels of miR-195 disrupted F-actin cytoskeleton organization, which was prevented by ARP2 overexpression. These results indicate that miR-195 inhibits early epithelial restitution by decreasing ARP-2 translation and that miR-195 expression is negatively regulated by cellular polyamines.
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Mucosa Intestinal , MicroARNs , Proteína 2 Relacionada con la Actina/metabolismo , Actinas/genética , Actinas/metabolismo , Movimiento Celular/genética , Células Epiteliales/metabolismo , Mucosa Intestinal/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Poliaminas/metabolismo , ARN Mensajero/metabolismo , Cicatrización de Heridas/genéticaRESUMEN
BACKGROUND: Our previous data demonstrated that miR-19b expression was increased in human lung microvascular endothelial cells in-vitro-, in-vivo and in patients with hemorrhagic shock, leading to a decrease in syndecan-1 mRNA and protein and resulting in loss of endothelial barrier function. However, the mechanism underlying increased miR-19b expression remains unclear. The objective of the current study was to determine if c-Jun mediates the early responsive microRNA, miR-19b, to cause endothelial barrier dysfunction. METHOD: Human lung microvascular endothelial cells (HLMEC) or HEK293T cells were transfected with c-Jun overexpressing vector, c-Jun siRNA, miR-19b promoter vector, miR-19b mutated promoter vector, miR-19b oligo inhibitor, then subjected to hypoxia/reoxygenation as in-vitro model of hemorrhagic shock. Levels of protein, miRNA, and luciferase activity were measured. Transwell permeability of endothelial monolayers were also determined. Plasma levels of c-Jun were measured in injured patients with hemorrhagic shock. RESULT: Hypoxia/reoxygenation induced primary (pri-)miR-19b, mature miR-19b, and c-Jun expression over time in a comparable timeframe. c-Jun silencing by transfection with its specific siRNA reduced both pri-miR-19b and mature miR-19b levels. Conversely, c-Jun overexpression enhanced H/R-induced pri-miR-19b. Studies using a luciferase reporter assay revealed that in cells transfected with vectors containing the wild-type miR-19b promoter and luciferase reporter, c-Jun overexpression or hypoxia/ reoxygenation significantly increased luciferase activity. c-Jun knockdown reduced the luciferase activity in these cells, suggesting that the miR-19b promoter is directly activated by c-Jun. Further, chromatin immunoprecipitation assay confirmed that c-Jun directly bound to the promoter DNA of miR-19b and hypoxia/reoxygenation significantly increased this interaction. Additionally, c-Jun silencing prevented cell surface syndecan-1 loss and endothelial barrier dysfunction in HLMECs after hypoxia/reoxygenation. Lastly, c-Jun was significantly elevated in patients with hemorrhagic shock compared to healthy controls. CONCLUSION: Transcription factor c-Jun is inducible by hypoxia/reoxygenation, binds to and activates the miR-19b promoter. Using an in-vitro model of hemorrhagic shock, our findings identified a novel cellular mechanism whereby hypoxia/ reoxygenation increases miR-19b transcription by inducing c-Jun and leads to syndecan-1 decrease and endothelial cell barrier dysfunction. This finding supports that miR-19b could be a potential therapeutic target for hemorrhage shock.
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MicroARNs , Proteínas Proto-Oncogénicas c-jun/metabolismo , Choque Hemorrágico , Células Endoteliales/metabolismo , Células HEK293 , Humanos , Hipoxia/metabolismo , MicroARNs/metabolismo , ARN Mensajero/metabolismo , ARN Interferente Pequeño , Choque Hemorrágico/genética , Choque Hemorrágico/metabolismo , Sindecano-1/metabolismo , Factores de Transcripción/metabolismoRESUMEN
BACKGROUND & AIMS: Circular RNAs (circRNAs) are a class of endogenous noncoding RNAs that form covalently closed circles. Although circRNAs influence many biological processes, little is known about their role in intestinal epithelium homeostasis. We surveyed circRNAs required to maintain intestinal epithelial integrity and identified circular homeodomain-interacting protein kinase 3 (circHIPK3) as a major regulator of intestinal epithelial repair after acute injury. METHODS: Intestinal mucosal tissues were collected from mice exposed to cecal ligation and puncture for 48 hours and patients with inflammatory bowel diseases and sepsis. We isolated primary enterocytes from the small intestine of mice and derived intestinal organoids. The levels of circHIPK3 were silenced in intestinal epithelial cells (IECs) by transfection with small interfering RNAs targeting the circularization junction of circHIPK3 or elevated using a plasmid vector that overexpressed circHIPK3. Intestinal epithelial repair was examined in an in vitro injury model by removing part of the monolayer. The association of circHIPK3 with microRNA 29b (miR-29b) was determined by biotinylated RNA pull-down assays. RESULTS: Genome-wide profile analyses identified â¼300 circRNAs, including circHIPK3, differentially expressed in the intestinal mucosa of mice after cecal ligation and puncture relative to sham mice. Intestinal mucosa from patients with inflammatory bowel diseases and sepsis had reduced levels of circHIPK3. Increasing the levels of circHIPK3 enhanced intestinal epithelium repair after wounding, whereas circHIPK3 silencing repressed epithelial recovery. CircHIPK3 silencing also inhibited growth of IECs and intestinal organoids, and circHIPK3 overexpression promoted intestinal epithelium renewal in mice. Mechanistic studies revealed that circHIPK3 directly bound to miR-29b and inhibited miR-29 activity, thus increasing expression of Rac1, Cdc42, and cyclin B1 in IECs after wounding. CONCLUSIONS: In studies of mice, IECs, and human tissues, our results indicate that circHIPK3 improves repair of the intestinal epithelium at least in part by reducing miR-29b availability.
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Movimiento Celular , Proliferación Celular , Células Epiteliales/metabolismo , Enfermedades Inflamatorias del Intestino/metabolismo , Mucosa Intestinal/metabolismo , MicroARNs/metabolismo , ARN Circular/metabolismo , Sepsis/metabolismo , Animales , Células Cultivadas , Ciclina B1/genética , Ciclina B1/metabolismo , Modelos Animales de Enfermedad , Regulación hacia Abajo , Células Epiteliales/patología , Femenino , Homeostasis , Humanos , Enfermedades Inflamatorias del Intestino/genética , Enfermedades Inflamatorias del Intestino/patología , Mucosa Intestinal/patología , Masculino , Ratones Endogámicos C57BL , MicroARNs/genética , Neuropéptidos/genética , Neuropéptidos/metabolismo , ARN Circular/genética , Sepsis/genética , Sepsis/patología , Cicatrización de Heridas , Proteína de Unión al GTP cdc42/genética , Proteína de Unión al GTP cdc42/metabolismo , Proteína de Unión al GTP rac1/genética , Proteína de Unión al GTP rac1/metabolismoRESUMEN
Collision cross section (CCS) values generated from ion mobility mass spectrometry (IM-MS) have commonly been employed to facilitate lipid identification. However, this is hindered by the limited available lipid standards. Recently, CCS values were predicted by means of computational calculations, though the prediction precision was generally not good and the predicted CCS values of the lipid isomers were almost identical. To address this challenge, a least absolute shrinkage and selection operator (LASSO)-based prediction method was developed for the prediction of lipids' CCS values in this study. In this method, an array of molecular descriptors were screened and optimized to reflect the subtle differences in structures among the different lipid isomers. The use of molecular descriptors together with a wealth of standard CCS values for the lipids (365 in total) significantly improved the accuracy and precision of the LASSO model. Its accuracy was externally validated with median relative errors (MREs) of <1.1% using an independent data set. This approach was demonstrated to allow differentiation of cis/trans and sn-positional isomers. The results also indicated that the LASSO-based prediction method could practically reduce false-positive identifications in IM-MS-based lipidomics.
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Espectrometría de Movilidad Iónica , Lipidómica , Espectrometría de Movilidad Iónica/métodos , Isomerismo , Lípidos/análisisRESUMEN
The ethyl acetate fraction of ethanol extract of Eucommiae Cortex can effectively inhibit joint inflammation and bone destruction in rats with collagen-induced arthritis(CIA) and has a potential therapeutic effect on rheumatoid arthritis. The triterpenoid(EU-Tid) and iridoid(EU-Idd) of Eucommiae Cortex are derivatives isolated from the ethyl acetate fraction of the ethanol extract of Eucommiae Cortex, and it is not clear whether they have inhibitory effects on joint inflammation and bone erosion in CIA rats. Therefore, based on the CIA model, the effects of EU-Tid, EU-Idd, and their combination(EU-TP) on arthritis in rats were observed, and the material basis of Eucommiae Cortex against arthritis was further clarified. The samples were collected two and four weeks after administration to observe the pathological changes in different stages of arthritis in CIA rats. For the rats in the model control group, with the prolongation of the disease course, the paw volume and arthritis score increased and histopathological lesions aggravated. Compared with the model control group, the drug administration groups showed reduced paw volumes and arthritis scores, and improved joint lesions and cartilage destruction. Additionally, the mRNA expression levels of tumor necrosis factor-α(TNF-α), interleukin-17(IL-17), and interleukin-23(IL-23) in the spleen were down-regulated in the drug administration groups. EU-TP and EU-Tid at concentrations of 160 and 320 µg·mL~(-1) could significantly inhibit the proliferation of human fibroblast-like synoviocytes-RA(HFLS-RA) and nitric oxide(NO) release in the supernatant of RAW264.7 cells induced by lipopolysaccharide(LPS) at the concentration range of 10-80 µg·mL~(-1) in vitro. EU-Idd had no effect on the proliferation of HFLS-RA but could reduce the NO release at concentrations of 40 and 80 µg·mL~(-1). The results indicated that the terpenoids of Eucommiae Cortex had great potential in the treatment of rheumatoid arthritis.
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Artritis Experimental , Artritis Reumatoide , Triterpenos , Ratas , Humanos , Animales , Artritis Experimental/tratamiento farmacológico , Iridoides/farmacología , Triterpenos/farmacología , Triterpenos/uso terapéutico , Artritis Reumatoide/inducido químicamente , Artritis Reumatoide/tratamiento farmacológico , Factor de Necrosis Tumoral alfa , Extractos Vegetales/farmacología , Inflamación/tratamiento farmacológico , Etanol , CitocinasRESUMEN
Wuhan was the first large city where the initial breakout of COVID-19 took numerous lives. A group of social workers and mental health specialists coordinated the "Be Together Program" (BTP), a psychosocial grief intervention program to help a group of Wuhan COVID-19 bereaved people. Under the Dual-process model framework, BTP used the internet and social media as the main tools, combined with group and individual intervention. Additionally, it employed a "Supermarket Mode" with abundant intervention themes and approaches for BTP participants to choose according to their special needs. Additionally, Chinese cultural elements are integrated into the program. At the end of the program, the grief scores of participants in the qualified sample reduced significantly, and the prevalence of the potential Prolonged Grief Disorder diagnosis reduced from 75% to 12%. The study also found that the BTP was especially effective for those who had high levels of grief reaction.
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Intestinal Tuft cells sense luminal contents to influence the mucosal immune response against eukaryotic infection. Paneth cells secrete antimicrobial proteins as part of the mucosal protective barrier. Defects in Tuft and Paneth cells occur commonly in various gut mucosal disorders. MicroRNA-195 (miR-195) regulates the stability and translation of target mRNAs and is involved in many aspects of cell processes and pathologies. Here, we reported the posttranscriptional mechanisms by which miR-195 regulates Tuft and Paneth cell function in the small intestinal epithelium. Mucosal tissues from intestinal epithelial tissue-specific miR-195 transgenic (miR195-Tg) mice had reduced numbers of double cortin-like kinase 1 (DCLK1)-positive (Tuft) and lysozyme-positive (Paneth) cells, compared with tissues from control mice, but there were no effects on Goblet cells and enterocytes. Intestinal organoids expressing higher miR-195 levels from miR195-Tg mice also exhibited fewer Tuft and Paneth cells. Transgenic expression of miR-195 in mice failed to alter growth of the small intestinal mucosa but increased vulnerability of the gut barrier in response to lipopolysaccharide (LPS). Studies aimed at investigating the mechanism underlying regulation of Tuft cells revealed that miR-195 directly interacted with the Dclk1 mRNA via its 3'-untranslated region and inhibited DCLK1 translation. Interestingly, the RNA-binding protein HuR competed with miR-195 for binding Dclk1 mRNA and increased DCLK1 expression. These results indicate that miR-195 suppresses the function of Tuft and Paneth cells in the small intestinal epithelium and further demonstrate that increased miR-195 disrupts Tuft cell function by inhibiting DCLK1 translation via interaction with HuR.
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Mucosa Intestinal/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , MicroARNs/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Células CACO-2 , Línea Celular , Línea Celular Tumoral , Quinasas Similares a Doblecortina , Enterocitos/metabolismo , Femenino , Células Caliciformes/metabolismo , Células HEK293 , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Organoides/metabolismoRESUMEN
Polyamines regulate a variety of physiological functions and are involved in pathogenesis of diverse human diseases. The epithelium of the mammalian gut mucosa is a rapidly self-renewing tissue in the body, and its homeostasis is preserved through well-controlled mechanisms. Here, we highlight the roles of cellular polyamines in maintaining the integrity of the gut epithelium, focusing on the emerging evidence of polyamines in the regulation of gut epithelial renewal and barrier function. Gut mucosal growth depends on the available supply of polyamines to the dividing cells in the crypts, and polyamines are also essential for normal gut epithelial barrier function. Polyamines modulate expression of various genes encoding growth-associated proteins and intercellular junctions via distinct mechanisms involving RNA-binding proteins and noncoding RNAs. With the rapid advance of polyamine biology, polyamine metabolism and transport are promising therapeutic targets in our efforts to protect the gut epithelium and barrier function in patients with critical illnesses.
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Proliferación Celular , Autorrenovación de las Células , Células Epiteliales/metabolismo , Mucosa Intestinal/metabolismo , Poliaminas/metabolismo , Animales , Células Epiteliales/patología , Humanos , Mucosa Intestinal/patología , Permeabilidad , Transducción de SeñalRESUMEN
Homeostasis of the intestinal epithelium is tightly regulated by numerous extracellular and intracellular factors including vitamin D and the vitamin D receptor (VDR). VDR is highly expressed in the intestinal epithelium and is implicated in many aspects of gut mucosal pathophysiology, but the exact mechanism that controls VDR expression remains largely unknown. The RNA-binding protein human antigen R (HuR) regulates the stability and translation of target mRNAs and thus modulates various cellular processes and functions. Here we report a novel role of HuR in the posttranscriptional control of VDR expression in the intestinal epithelium. The levels of VDR in the intestinal mucosa decreased significantly in mice with ablated HuR, compared with control mice. HuR silencing in cultured intestinal epithelial cells (IECs) also reduced VDR levels, whereas HuR overexpression increased VDR abundance; neither intervention changed cellular Vdr mRNA content. Mechanistically, HuR bound to Vdr mRNA via its 3'-untranslated region (UTR) and enhanced VDR translation in IECs. Moreover, VDR silencing not only inhibited IEC migration over the wounded area in control cells but also prevented the increased migration in cells overexpressing HuR, although it did not alter IEC proliferation in vitro and growth of intestinal organoids ex vivo. The human intestinal mucosa from patients with inflammatory bowel diseases exhibited decreased levels of both HuR and VDR. These results indicate that HuR enhances VDR translation by directly interacting with its mRNA via 3'-UTR and that induced VDR by HuR is crucial for rapid intestinal epithelial restitution after wounding.
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Proteína 1 Similar a ELAV/metabolismo , Células Epiteliales/metabolismo , Mucosa Intestinal/lesiones , Mucosa Intestinal/metabolismo , Biosíntesis de Proteínas/fisiología , Receptores de Calcitriol/metabolismo , Animales , Proteína 1 Similar a ELAV/genética , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Organoides/lesiones , Organoides/metabolismo , Ratas , Receptores de Calcitriol/genéticaRESUMEN
BACKGROUND & AIMS: Paneth cells secrete antimicrobial proteins including lysozyme via secretory autophagy as part of the mucosal protective response. The ELAV like RNA-binding protein 1 (ELAVL1, also called HuR) regulates stability and translation of messenger RNAs (mRNAs) and many aspects of mucosal physiology. We studied the posttranscriptional mechanisms by which HuR regulates Paneth cell function. METHODS: Intestinal mucosal tissues were collected from mice with intestinal epithelium (IE)-specific disruption of HuR (IE-HuR-/-), HuRfl/fl-Cre- mice (controls), and patients with inflammatory bowel diseases and analyzed by histology and immunohistochemistry. Paneth cell functions were determined by lysozyme-immunostaining assays. We isolated primary enterocytes from IE-HuR-/- and control mice and derived intestinal organoids. HuR and the chaperone CNPY3 were overexpressed from transgenes in intestinal epithelial cells (IECs) or knocked down with small interfering RNAs. We performed RNA pulldown assays to investigate interactions between HuR and its target mRNAs. RESULTS: Intestinal tissues from IE-HuR-/- mice had reduced numbers of Paneth cells, and Paneth cells had fewer lysozyme granules per cell, compared with tissues from control mice, but there were no effects on Goblet cells or enterocytes. Intestinal mucosa from patients with inflammatory bowel diseases had reduced levels of HuR and fewer Paneth cells. IE-HuR-/- mice did not have the apical distribution of TLR2 in the intestinal mucosa as observed in control mice. IECs from IE-HuR-/- mice expressed lower levels of CNPY3. Intestinal organoids from IE-HuR-/- mice were smaller and contained fewer buds compared with those generated from controls, and had fewer lysozyme-positive cells. In IECs, knockdown of HuR decreased levels of the autophagy proteins LC3-I and LC3-II, compared with control cells, and prevented rapamycin-induced autophagy. We found HuR to interact directly with the Cnpy3 mRNA coding region and increase levels of CNPY3 by increasing the stability and translation of Cnpy3 mRNA. CNPY3 bound TLR2, and cells with knockdown of CNPY3 or HuR lost membrane localization of TLR2, but increased cytoplasmic levels of TLR2. CONCLUSIONS: In studies of mice, IECs, and human tissues, we found HuR to increase expression of CNPY3 at the posttranscriptional level. CNPY3 is required for membrane localization of TLR2 and Paneth cell function.
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Membrana Celular/metabolismo , Proteína 1 Similar a ELAV/metabolismo , Intestino Delgado/metabolismo , Chaperonas Moleculares/metabolismo , Células de Paneth/metabolismo , Procesamiento Postranscripcional del ARN , Receptor Toll-Like 2/metabolismo , Animales , Estudios de Casos y Controles , Células Cultivadas , Proteína 1 Similar a ELAV/deficiencia , Proteína 1 Similar a ELAV/genética , Humanos , Enfermedades Inflamatorias del Intestino/genética , Enfermedades Inflamatorias del Intestino/metabolismo , Enfermedades Inflamatorias del Intestino/patología , Intestino Delgado/patología , Ratones Endogámicos C57BL , Ratones Noqueados , Chaperonas Moleculares/genética , Células de Paneth/patología , Transporte de Proteínas , Transducción de Señal , Regulación hacia ArribaRESUMEN
Two new xanthones smilone A (1), smilone B (2), and a new lignin smilgnin A (3) were isolated from the rhizomes of Smilax china L., together with three known xanthones (4-6), four lignins (7-10), two flavones (11, 12), two stilbenoids (13, 14), and ten organic phenoloids (15-24). Of them, compounds 4-6 were isolated from the genus Smilax for the first time. The structures of 1-24 were elucidated by the extensive analysis of spectral data and compared with the literature. All compounds were evaluated for their inhibitory effects against LPS-induced NO production in RAW264.7 macrophages. Among them, compound 24 exhibited significant inhibitory activity against NO production (IC50 = 1.26 µM), while compounds 3, 6, and 7 showed weak activities at the concentration of 50 µM.[Formula: see text].
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Smilax , Xantonas , China , Lignina , Estructura MolecularRESUMEN
The mammalian intestinal epithelium is a rapidly self-renewing tissue in the body and directly interfaces with a wide array of luminal noxious contents and microorganisms. Homeostasis of the intestinal epithelium is preserved through well-controlled mechanisms including posttranscriptional regulation. RNA-binding protein (RBP) HuR regulates the stability and translation of target mRNAs and is intimately involved in many aspects of gut mucosal pathophysiology. Here we highlight the biological roles of HuR in maintaining the integrity of the intestinal epithelium, with particular focus on the emerging evidence of HuR in the regulation of intestinal epithelial renewal, mucosal repair, defense, and gut permeability. We also further analyze the mechanisms through which HuR and its interactions with other RBPs and noncoding RNAs (ncRNAs) such as microRNAs and long ncRNAs modulate the intestinal epithelial homeostasis. With rapidly advancing knowledge of RBPs and ncRNAs, there is growing recognition that posttranscriptional control of the intestinal epithelium homeostasis might be promising therapeutic targets in our efforts to protect the integrity of the intestinal epithelium under critical pathological conditions.
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Mucosa Intestinal , ARN Largo no Codificante , Animales , Regulación de la Expresión Génica , Homeostasis , Proteínas de Unión al ARNRESUMEN
The epithelium of the mammalian intestinal mucosa is a rapidly self-renewing tissue in the body, and its homeostasis is preserved through well-controlled mechanisms. Long noncoding RNAs (lncRNAs) regulate a variety of biological functions and are intimately involved in the pathogenesis of diverse human diseases. Here we highlight the roles of several lncRNAs expressed in the intestinal epithelium, including uc.173, SPRY4-IT1, H19, and Gata6, in maintaining the integrity of the intestinal epithelium, focusing on the emerging evidence of lncRNAs in the regulation of intestinal mucosal regeneration and epithelial barrier function. We also discuss recent results that the interactions between lncRNAs with microRNAs and the RNA-binding protein HuR influence epithelial homeostasis. With rapidly advancing knowledge of lncRNAs, there is also growing recognition that lncRNAs in the intestinal epithelium might be promising therapeutic targets in our efforts to protect the integrity of the intestinal epithelium in response to stressful environments.
Asunto(s)
Proliferación Celular , Células Epiteliales/metabolismo , Absorción Intestinal , Mucosa Intestinal/metabolismo , ARN Largo no Codificante/metabolismo , Regeneración , Animales , Regulación de la Expresión Génica , Homeostasis , Humanos , Permeabilidad , ARN Largo no Codificante/genética , Transducción de SeñalRESUMEN
Both zipcode binding protein-1 (ZBP1) and phospholipase C-γ1 (PLCγ1) are intimately involved in many aspects of early intestinal mucosal repair after acute injury, but the exact mechanisms that control their cellular abundances remain largely unknown. The present study shows that microRNA-222 (miR-222) interacts with the mRNAs encoding ZBP1 and PLCγ1 and regulates ZBP1 and PLCγ1 expression in intestinal epithelial cells (IECs). The biotinylated miR-222 bound specifically to the ZBP1 and PLCγ1 mRNAs in IECs. Ectopically expressed miR-222 precursor destabilized the ZBP1 and PLCγ1 mRNAs and consequently lowered the levels of cellular ZBP1 and PLCγ1 proteins. Conversely, decreasing the levels of cellular miR-222 by transfection with its antagonism increased the stability of the ZBP1 and PLCγ1 mRNAs and increased the levels of ZBP1 and PLCγ1 proteins. Overexpression of miR-222 also inhibited cell migration over the wounded area, which was partially abolished by overexpressing ZBP1 and PLCγ1. Furthermore, prevention of the increased levels of ZBP1 and PLCγ1 in the miR-222-silenced cells by transfection with specific small interfering RNAs targeting ZBP1 or PLCγ1 mRNA inhibited cell migration after wounding. These findings indicate that induced miR-222 represses expression of ZBP1 and PLCγ1 at the posttranscriptional level, thus inhibiting IEC migration during intestinal epithelial restitution after wounding.
Asunto(s)
Proteínas de Unión al ADN/metabolismo , Células Epiteliales/metabolismo , Mucosa Intestinal/metabolismo , MicroARNs/metabolismo , Fosfolipasa C gamma/metabolismo , Línea Celular Tumoral , Movimiento Celular/fisiología , Células HCT116 , Humanos , Intestinos/fisiología , Interferencia de ARN/fisiología , ARN Mensajero/metabolismo , Proteínas de Unión al ARN , Transfección/métodos , Cicatrización de Heridas/fisiologíaRESUMEN
BACKGROUND AND AIMS: The mammalian intestinal epithelium self-renews rapidly and homeostasis is preserved via tightly controlled mechanisms. Long noncoding RNAs transcribed from ultraconserved regions (T-UCRs) control different cell functions, but little is known about their role in maintaining the integrity of the intestinal epithelium. We searched for T-UCRs that regulate growth of the intestinal mucosa and investigated the mechanism by which T-UCR uc.173 regulates epithelial renewal. METHODS: C57BL/6J mice were deprived of food for 48 hours in fasting experiments. Some mice were given intraperitoneal injections of a plasmid encoding LNA-anti-uc.173, to knock down endogenous uc.173. For studies using organoids, primary enterocytes were isolated from the intestine and transfected with the uc.173 transgene to increase uc.173 levels. Intestinal epithelial cells (Caco-2 and IEC-6 lines) were transfected with LNA-anti-uc.173 or uc.173 transgene. We quantified intestinal epithelial renewal based on BrdU incorporation, villus height and crypt depth, and cell number. The association of uc.173 with microRNA 195 (miRNA195) was determined by RNA pull-down assays. RESULTS: Genome-wide profile analyses identified 21 T-UCRs, including uc.173, that were differentially expressed between intestinal mucosa of fasted vs non-fasted mice. Increasing levels of uc.173 by expression of a transgene increased growth of intestinal epithelial cells and organoids. Decreasing uc.173 levels by LNA-anti-uc.173 in mice reduced renewal of the intestinal epithelium. We found that uc.173 interacted directly with the primary transcript of miRNA195, leading to miRNA195 degradation. CONCLUSIONS: In analyses of intestinal epithelial cells and mice, we identified uc.173 noncoding RNA that regulates growth of the intestinal mucosa and stimulates intestinal epithelial renewal by reducing levels of miRNA195.