RESUMO
The subretina, composed of the choroid and the retinal pigment epithelium (RPE), bears a critical role in proper vision. In addition to phagocytosis of photoreceptor debris, the RPE shuttles oxygen and nutrients to the neuroretina. For their own energy production, RPE cells mainly rely on lactate, a major by-product of glycolysis. Lactate, in turn, is believed to convey most of its biological effects via the hydroxycarboxylic acid receptor 1 (HCAR1). Here, the lactate-specific receptor, HCAR1, is found to be exclusively expressed in the RPE cells within the subretina, and Hcar1-/- mice exhibit a substantially thinner choroidal vasculature during development. Notably, the angiogenic properties of lactate on the choroid are impacted by the absence of Hcar1. HCAR1-deficient mice exhibit elevated endoplasmic reticulum stress along with eukaryotic initiation factor 2α phosphorylation, a significant decrease in the global protein translation rate, and a lower proliferation rate of choroidal vasculature. Strikingly, inhibition of the integrated stress response using an inhibitor that reverses the effect of eukaryotic initiation factor 2α phosphorylation restores protein translation and rescues choroidal thinning. These results provide evidence that lactate signalling via HCAR1 is important for choroidal development/angiogenesis and highlight the importance of this receptor in establishing mature vision.
RESUMO
BACKGROUND: Gestational diabetes mellitus (GDM) poses significant health risks for both mothers and children, contributing to long-term complications such as type 2 diabetes and cardiovascular disease. This study explores the potential of microRNAs (miRNAs) as biomarkers for GDM by analyzing peripheral blood samples from GDM patients. METHOD: Ten samples, including peripheral blood from 5 GDM patients and 5 controls, were collected to perform the RNA sequencing analysis. Differentially expressed miRNAs were further validated by quantitative real-time polymerase chain reaction. RESULTS: A total of 2287 miRNAs were identified, 229 of which showed differential expression. Validation by qRT-PCR confirmed significant up-regulation of miR-5193, miR-5003-3p, miR-3127-5p, novel-miR-96, miR-6734-5p, and miR-122-5p, while miR-10395-3p was down-regulated. Bioinformatics analyses revealed the involvement of these miRNAs in pathways associated with herpes simplex virus 1 infection. CONCLUSION: This study provides insights into the differential expression of miRNAs in GDM patients and their potential roles in disease pathogenesis. It suggests that the differentially expressed miRNAs could serve as potential biomarkers for GDM, shedding light on the complex molecular mechanisms involved.
Assuntos
Biomarcadores , Diabetes Gestacional , MicroRNAs , Análise de Sequência de RNA , Humanos , Diabetes Gestacional/genética , Diabetes Gestacional/sangue , Diabetes Gestacional/diagnóstico , Feminino , Gravidez , MicroRNAs/sangue , MicroRNAs/genética , Adulto , Biomarcadores/sangue , Estudos de Casos e Controles , Reação em Cadeia da Polimerase em Tempo Real , Regulação para Cima , Regulação para Baixo , Perfilação da Expressão Gênica , Biologia ComputacionalRESUMO
BACKGROUND: The mental health of healthcare workers during the coronavirus-2019 pandemic was seriously affected, and the risk of mental health problems was high. The present study sought to systematically evaluate the mental health problems of healthcare workers worldwide during the pandemic and to determine the latest global frequency of COVID-19 associated mental health problems. METHODS: Data in the Cumulative Index to Nursing and Allied Health Literature (CINAHL), EMBASE, Elsevier, MEDLINE, PubMed, PsycINFO and the Web of Science before November 11, 2022, were systematically searched. Cohort, case-control and cross-sectional studies were included. The meta-analysis used a random effects model to synthesize the comprehensive prevalence rate of mental health problems. Subgroup analyses were performed based on time of data collection; whether the country was or was not developed; continent; doctors and nurses; doctors/nurses vs. other healthcare workers; and psychological evaluation scale. RESULTS: A total of 161 studies were included, including 341,014 healthcare workers worldwide, with women accounting for 82.8%. Occupationally, 16.2% of the healthcare workers were doctors, 63.6% were nurses and 13.3% were other medical staff. During the pandemic, 47% (95% confidence interval [CI], 35-60%) of healthcare workers reported job burnout, 38% (95% CI, 35-41%) experienced anxiety, 34% (95% CI 30-38%) reported depression, 30% (95% CI, 29-31%) had acute stress disorder, and 26% (95% CI, 21-31%) had post-traumatic stress disorder. CONCLUSIONS: The study found that there were common mental health problems among health care workers during the COVID-19 pandemic. The most common was job burnout, followed by anxiety, depression, acute stress and post-traumatic stress disorder. Although the global pandemic has been brought under control, its long-term impact on the mental health of healthcare workers cannot be ignored. Additional research is required to develop measures to prevent, monitor and treat psychological disorders among healthcare workers.
Assuntos
Esgotamento Profissional , COVID-19 , Feminino , Humanos , Ansiedade/epidemiologia , Ansiedade/terapia , Esgotamento Profissional/epidemiologia , COVID-19/epidemiologia , Estudos Transversais , Depressão/epidemiologia , Depressão/terapia , Pessoal de Saúde/psicologia , Nível de Saúde , Pandemias , Prevalência , MasculinoRESUMO
Incomplete pulmonary function and insufficient production of pulmonary surfactant in premature infants may affect alveolar relaxation, inducing neonatal respiratory distress syndrome (NRDS). The present study was a retrospective comparison of lipid metabolism indexes and clinic information between NRDS and non-NRDS infants. Data on general information, pregnancy, clinical symptoms, family history as well as plasma biochemical and lipid metabolic indexes were retrospectively collected and statistically analyzed from 79 patients with NRDS and 44 non-NRDS infants. Infants in the NRDS group showed lower body weight (2,055 vs. 3,225 g) and gestation age (33.39 vs. 38.53 weeks) than those in the non-NRDS group (P<0.05). Baseline information was corrected by the inverse probability of treatment weighting (IPTW) analysis. The weighted adjusted median age was the same in both groups and there was no significant difference between two groups in birth weight. The IPTW analysis revealed that the levels of plasma triglyceride (TG), total cholesterol, low-density lipoprotein, free triiodothyronine, free thyroxine, glucose, calcium (Ca2+) and phosphorus in the NRDS infants were significantly lower compared with those in the non-NRDS infants. Additionally, NRDS infants had significantly higher incidence rates of pneumonia, sepsis, brain injury infection, preterm birth, patent foramen ovale, patent ductus arteriosus and premature rupture of membranes compared with the non-NRDS infants (P<0.05). Multivariate logistic analysis showed that TG and Ca2+ were risk factors associated with NRDS (P<0.05). Infants with NRDS have significantly lower levels of plasma lipid indexes. The results of the present study provide data to guide the clinical management of NRDS.
RESUMO
The development of green, controllable, and simplified pathways for rapid dopamine polymerization holds significant importance in the field of polydopamine (PDA) surface chemistry. In this study, a green strategy is successfully devised to accelerate and control the polymerization of dopamine through the introduction of ozone (O3 ). The findings reveal that ozone serves as an eco-friendly trigger, significantly accelerating the dopamine polymerization process across a broad pH range, spanning from 4.0 to 10.0. Notably, the deposition rate of PDA coatings on a silicon wafer reaches an impressive value of ≈64.8 nm h-1 (pH 8.5), which is 30 times higher than that of traditional air-assisted PDA and comparable to the fastest reported method. Furthermore, ozone exhibits the ability to accelerate dopamine polymerization even under low temperatures. It also enables control over the inhibition-initiation of the polymerization process by regulating the "ON/OFF" mode of the ozone gas. Moreover, the ozone-induced PDA coatings demonstrate exceptional characteristics, including high homogeneity, good hydrophilicity, and remarkable chemical and mechanical stability. Additionally, the ozone-induced PDA coatings can be rapidly and effectively deposited onto a wide range of substrates, particularly those that are adhesion-resistant, such as polytetrafluoroethylene (PTFE).
RESUMO
Background: Inflammatory bowel disease (IBD) is a condition with an unclear genetic basis. Fucosyltransferase 3 (FUT3) could potentially be linked to IBD susceptibility. Objective: To investigate the association between FUT3 gene polymorphisms and IBD. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 checklist and Population, Intervention, Comparison, Outcomes, and Study (PICOS) guidelines, case-control studies published until April 30, 2020 was searched. Two independent reviewers conducted screening, data extraction, and quality assessment using the Newcastle-Ottawa Scale. Meta-analysis, sensitivity analysis, and Egger tests were performed using RevMan and Stata12.0. Results: The review included 5 articles and 12 case-control studies involving 1712 IBD patients and 1903 controls. The meta-analysis revealed the following combined odds ratios [95% confidence intervals]: rs3745635 genotype (GA+AA vs GG) 0.84 (0.72-0.97), (GG+GA vs AA) 1.93 (1.23-3.05), (GG vs AA) 2.38 (1.52-3.74), (A vs G) 0.84 (0.73-0.96); rs3894326 genotype (TA+AA vs TT) 1.03 (0.87-1.23), (TT+TA vs AA) 1.19 (0.56-2.51), (TT vs AA) 1.19 (0.56-2.51), (A vs T) 1.02 (0.86-1.20); rs28362459 genotype (TG+GG vs TT) 0.98 (0.85-1.12), (TT+TG vs GG) 1.20 (0.90-1.61), (TT vs GG) 1.21 (0.90-1.62), (G vs T) 0.96 (0.86-1.07). Sensitivity analysis indicated the stability of the results, and Egger analysis showed no significant publication bias. Conclusions: The rs3745635 gene polymorphism may be associated with IBD susceptibility, whereas the rs3894326 and rs28362459 gene polymorphisms may not be associated with IBD.
RESUMO
To decrease the dipole polarization rate and reduce the dielectric constant of poly(aryl ether ketone) (PAEK) resin, 1,4-di(4-fluorobenzoyl) cyclohexane (DFBCH), a weakly polarizing cyclohexane-based monomer, was designed and synthesized as the primary reactant. The bulky fluorene group was incorporated to increase the free volume of the resin, further reducing the dielectric constant. Additionally, hydroquinone with a symmetric and regular structure was utilized to enhance the molecular chain's regularity and reduce dipole relaxation, further lowering the resin's dielectric constant and dielectric loss. The PFQEKs series resins exhibited excellent thermal stability with glass transition temperature (Tg) ranging from 222 to 239 °C and 5% weight loss (Td5%) ranging from 458 to 463 °C, with different monomer ratios. As the hydroquinone content increased, the dielectric constant (Dk) and dielectric loss (Df) of the resin decreased significantly, with Dk ranging from 2.92 to 2.77 and Df ranging from 0.011 to 0.008 at 10 GHz.
RESUMO
There is a symbiotic relationship between gut microbiota and human beings. Imbalance of the gut microbiota will cause pathological damages to humans. Although many risk factors are associated with missed abortion (MA), the pathological mechanism of it is still unclear. Here, we analyzed gut flora of the patients with MA by S16 high-throughput sequencing. The possible pathogenic mechanisms of the MA were explored. Fecal samples from 14 healthy controls and 16 MA patients were collected to do 16S rRNA gene high-throughput sequencing analysis. The abundance of the Bacteroidetes, Proteobacteria, Actinobacteria, Escherichia, Streptococcus_ Salivarius, and Lactobacillus was significantly reduced in the MA group, while, the abundance of the Klebsiella was significantly increased in the MA patients. The Ruminococcaceae and [Eubacterium]_coprostanoligenes_group were found only in the specimens of the MA patients. The Fabrotax function prediction analysis showed that four photosynthesis function bacteria (cyanobateria, oxygenic_photoautotrophy, photoautotrophy, and phototrophy) only existed in the MA group. In the analysis of the BugBase microbiome function prediction, the Escherichia of the MA group is significantly reduced compared to that of the healthy controls in the items of that Contains_Mobile_Elements, Facultatively_Anaerobic, Forms_Biofilms, Potentially_Pathogenic.png, Gram_Nagative, and Stress_Tolerant_relabundance. These alterations may affect the stability of the host's immune, neural, metabolic and other systems by interfering with the balance of the gut microbiota or by the metabolites of those bacteria, causing the MA. This study explored the possible pathogenic factors of the gut microbiota of the MA. The results provide evidence to figure out the pathogenesis of the MA.
RESUMO
Hydrogel coatings that can endow various substrates with superior properties (e.g., biocompatibility, hydrophilicity, and lubricity) have wide applications in the fields of oil/water separation, antifouling, anti-bioadhesion, etc. Currently, the engineering of multifunctional hydrogel-coated materials with superwettability and water purification property using a simple and sustainable strategy is still largely uninvestigated but has a beneficial effect on the world. Herein, we successfully prepared poly(2-acrylamido-2-methyl-1-propanesulfonic acid) hydrogel/ß-FeOOH-coated poly(vinylidene fluoride) (PVDF/PAMPS/ß-FeOOH) membrane through free-radical polymerization and the in situ mineralization process. In this work, owing to the combination of hydrophilic PAMPS hydrogel coating and ß-FeOOH nanorods anchored onto PVDF membrane, the resultant PVDF/PAMPS/ß-FeOOH membrane achieved outstanding superhydrophilicity/underwater superoleophobicity. Moreover, the membrane not only effectively separated surfactant-stabilized oil/water emulsions, but also possessed a long-term use capacity. In addition, excellent photocatalytic activity against organic pollutants was demonstrated so that the PVDF/PAMPS/ß-FeOOH membrane could be utilized to deal with wastewater. It is envisioned that these hydrogel/ß-FeOOH-coated PVDF membranes have versatile applications in the fields of oil/water separation and wastewater purification.
RESUMO
Nanofiber bundles with specific areas bring a new opportunity for selective adsorption and oil/water or air separation. In this work, nanofiber bundles were prepared by the electrospinning of immiscible polystyrene (PS)/N-trifluoroacetylated polyamide 6 (PA6-TFAA) blends via the introduction of carbon nanotubes (CNTs) or a copolymer of styrene and 3-isopropenyl-α, α'-dimethylbenzene isocyanate (TMI), which was denoted as PS-co-TMI. Herein, CNT was used to increase the conductivity of the precursor for enhancing the stretch of PS droplets under the same electric field, and PS-co-TMI was used as a reactive compatibilizer to improve the compatibility of a PS/PA6-TFAA blend system for promoting the deformation. Those obtained nanofiber bundle membranes showed an increase in tensile strength and high hydrophobicity with a water contact angle of about 145.0 ± 0.5°. Owing to the special structure, the membranes also possessed a high oil adsorption capacity of 31.0 to 61.3 g/g for different oils. Moreover, it exhibits a high potential for gravity-driven oil/water separation. For example, those membranes had above 99% separation efficiency for silicon oil/water and paraffin wax/water. Furthermore, the air filtration efficiency of nanofiber bundle membranes could reach above 96%, which might be two to six times higher than the filtration efficiency of neat PS membranes.
RESUMO
Isofurans (IsoFs) are a series of novel discovered lipid peroxidation products. This study focused on the investigation of the angiogenic property of IsoF. MTT stain assay indicated that 1 µm IsoF had the most bioactivity in rat brain endothelial cells (RBECs). IsoF significantly promoted cellular proliferation and migration and remarkably decreased staurosporine-induced apoptosis by TUNEL assay in the RBECs. It successfully up-regulated rat aortic vascularization and choroid explant sprouting, extracellular regulated protein kinases (ERK)1/2, and triggered calcium release. RT-PCR examination indicated that IsoF up-regulated tumor necrosis factor (TNF)α, angiopoietin-1 receptor (Tie2), and vascular endothelial growth factor (VEGF)-A, but did not interfere with caspase 2 and VEGF-C in the RBECs. IsoF has pro-angiogenic activity. Calcium release and ERK1/2 phosphorylation may be involved in the signaling of the IsoF-induced up-regulation of TNFα, Tie2, and VEGF-A, which could be the molecular mechanism of the pro-angiogenic activity of the IsoF.
Assuntos
Angiopoietina-1 , Fator A de Crescimento do Endotélio Vascular , Ratos , Animais , Fator A de Crescimento do Endotélio Vascular/metabolismo , Angiopoietina-1/genética , Fator C de Crescimento do Endotélio Vascular , Caspase 2 , Células Endoteliais/metabolismo , Fator de Necrose Tumoral alfa , Cálcio/metabolismo , Estaurosporina , Neovascularização FisiológicaRESUMO
The GPCR SUCNR1/GPR91 exerts proangiogenesis upon stimulation with the Krebs cycle metabolite succinate. GPCR signaling depends on the surrounding environment and intracellular localization through location bias. Here, we show by microscopy and by cell fractionation that in neurons, SUCNR1 resides at the endoplasmic reticulum (ER), while being fully functional, as shown by calcium release and the induction of the expression of the proangiogenic gene for VEGFA. ER localization was found to depend upon N-glycosylation, particularly at position N8; the nonglycosylated mutant receptor localizes at the plasma membrane shuttled by RAB11. This SUCNR1 glycosylation is physiologically regulated, so that during hypoxic conditions, SUCNR1 is deglycosylated and relocates to the plasma membrane. Downstream signal transduction of SUCNR1 was found to activate the prostaglandin synthesis pathway through direct interaction with COX-2 at the ER; pharmacologic antagonism of the PGE2 EP4 receptor (localized at the nucleus) was found to prevent VEGFA expression. Concordantly, restoring the expression of SUCNR1 in the retina of SUCNR1-null mice renormalized vascularization; this effect is markedly diminished after transfection of the plasma membrane-localized SUCNR1 N8A mutant, emphasizing that ER localization of the succinate receptor is necessary for proper vascularization. These findings uncover an unprecedented physiologic process where GPCR resides at the ER for signaling function.
Assuntos
Receptores Acoplados a Proteínas G , Ácido Succínico , Animais , Membrana Celular/metabolismo , Retículo Endoplasmático/metabolismo , Hipóxia , Camundongos , Receptores Acoplados a Proteínas G/metabolismo , Succinatos , Ácido Succínico/metabolismoRESUMO
A fungus with biocontrol potential was isolated from the roots of hickory trees. The strain named sj18 was classified as a member of the genus Hypoxylon (Hypoxylaceae) after multigene phylogenetic analysis (beta-tubulin gene, internal transcribed spacer, 28S large subunit ribosomal RNA gene, and RNA polymerase II subunit gene). The strain grew well on a PDA with an optimum temperature range between 32 and 34 °C. The fungus had obvious inhibitory effects on Botryosphaeria dothidea, Colletotrichum gloeosporioides, and Gibberella moniliformis in fumigation experiments on solid agar plates. In an inoculation experiment of Chinese cabbage, the fungus was also found to have an obvious repellent effect on cabbage caterpillars. In vitro experiments on Petri dishes showed that the fermentation broth of the sj18 strain could kill 100% of Bursaphelenchus xylophilus within 8 h even if the fermentation broth was diluted 8 times. The inoculation test of Arabidopsis thaliana showed that the fungus could promote the lateral root formation of plants and significantly increase their aboveground biomass. Through the analysis of solid phase microextraction (SPME), it was found that the main volatile components of the fermentation products were azulene 65.39% (61.77% + 3.62%), caryophyllene 7.41%, and eucalyptol 6.83% according to the peak area ratio. Therefore, sj18 can be used as a candidate for the further research and development of biocontrol agents.
Assuntos
Arabidopsis , Xylariales , Filogenia , Raízes de Plantas , RNA Ribossômico 28S , Xylariales/genéticaRESUMO
3-Hydroxy-3-methylglutaryl coenzyme A reductase(HMGR) is the first rate-limiting enzyme in the mevalonic acid(MVA)pathway and it is an important regulatory site in the metabolism of terpenoids in the cytoplasm. In this study, Siraitia grosvenorii that had been pollinated 0 day,1 day,3 days,15 days and 30 days were used as experimental materials. Based on the transcriptome data, two HMGR genes were cloned from S. grosvenorii cDNA and named SgHMGR2(GenBank Accession Numbers MT270447) and SgHMGR3(GenBank Accession Number MT270448). The two genes contain open reading frames(ORFs) of 1 746 bp and 1 782 bp, encoding 582 and 594 amino acids, and their molecular masses are estimated to be 62.7,63.2 kDa, respectively. Isoelectric point are 8.34 and 7.47, both of which do not contain signal peptides, are non-secretory proteins, and have two transmembrane structures. Combining the conserved regions of the proteins and the analysis of the evolutionary tree, it was confirmed that the genes are indeed HMGR family genes. Real-time PCR was used to detect the expression pattern of SgHMGRs at different times after pollination, and the highest expression level was 15 days after pollination. Finally, two full-length SgHMGRs were cloned from S. grosvenorii for the first time, and the differential expression of SgHMGRs at different times after pollination was revealed, providing a research basis for the mining of key enzyme gene elements in the biosynthesis pathway of S. grosvenorii terpenoids.
Assuntos
Cucurbitaceae , Hidroximetilglutaril-CoA Redutases , Sequência de Aminoácidos , Clonagem Molecular , Coenzima A , Cucurbitaceae/genética , Hidroximetilglutaril-CoA Redutases/genética , Hidroximetilglutaril-CoA Redutases/metabolismo , FilogeniaRESUMO
Although it is well-known and established that light plays important roles in plant development, up to now, there is no substantial improvements in how to deal with the light factor of spring phenology under natural condition. By monitoring the local meteorologic data and mature dates of two types (male and female) of flower from four pecan cultivars during 9 years, it was found that the complementary pattern of growing degree day and sunshine duration helped to maintain a threshold of driving force related to the maturity of pecan flower during 9 years. A novel photothermal time model based on the linear combination of growing degree day and sunshine duration was then proposed and validated to interpret the variance of mature dates of pecan cultivars. Comparative analysis showed that the new model had made extremely significant improvements to the traditional thermal time model. In addition, this model introduced the conversion coefficient K, which quantified the effect of light on the flowering drive, and revealed the differences of base temperature among cultivars. This was the first time that sunshine duration instead of photoperiod was adopted to develop into a verified model on spring phenological event of tree species. It will help to model the spring phenologies of other tree species more reasonably.
Assuntos
Carya , Flores , Masculino , Fotoperíodo , Estações do AnoRESUMO
Retinopathy of prematurity (ROP) is characterized by an initial retinal avascularization, followed by pathologic neovascularization. Recently, choroidal thinning has also been detected in children formerly diagnosed with ROP; a similar sustained choroidal thinning is observed in ROP models. But the mechanism underlying the lack of choroidal revascularization remains unclear and was investigated in an oxygen-induced retinopathy (OIR) model. In OIR, evidence of senescence was detected, preceded by oxidative stress in the choroid and the retinal pigment epithelium. This was associated with a global reduction of proangiogenic factors, including insulin-like growth factor 1 receptor (Igf1R). Coincidentally, tumor suppressor p53 was highly expressed in the OIR retinae. Curtailing p53 activity resulted in reversal of senescence, normalization of Igf1r expression, and preservation of choroidal integrity. OIR-induced down-regulation of Igf1r was mediated at least partly by miR-let-7b as i) let-7b expression was augmented throughout and beyond the period of oxygen exposure, ii) let-7b directly targeted Igf1r mRNA, and iii) p53 knock-down blunted let-7b expression, restored Igf1r expression, and elicited choroidal revascularization. Finally, restoration of Igf1r expression rescued choroid thickness. Altogether, this study uncovers a significant mechanism for defective choroidal revascularization in OIR, revealing a new role for p53/let-7b/IGF-1R axis in the retina. Future investigations on this (and connected) pathway could further our understanding of other degenerative choroidopathies, such as geographic atrophy.
Assuntos
Corioide/irrigação sanguínea , Corioide/efeitos dos fármacos , MicroRNAs/fisiologia , Neovascularização Fisiológica/efeitos dos fármacos , Oxigênio/efeitos adversos , Retinopatia da Prematuridade/genética , Retinopatia da Prematuridade/patologia , Proteína Supressora de Tumor p53/fisiologia , Animais , Animais Recém-Nascidos , Células Cultivadas , Corioide/metabolismo , Corioide/patologia , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Células HEK293 , Humanos , Neovascularização Fisiológica/genética , Oxigênio/farmacologia , Ratos , Ratos Long-Evans , Epitélio Pigmentado da Retina/metabolismo , Epitélio Pigmentado da Retina/patologia , Retinopatia da Prematuridade/fisiopatologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genéticaRESUMO
Ischemic retinopathies are characterized by a progressive microvascular degeneration followed by a postischemic aberrant neovascularization. To reinstate vascular supply and metabolic equilibrium to the ischemic tissue during ischemic retinopathies, a dysregulated production of growth factors and metabolic intermediates occurs, promoting retinal angiogenesis. Glycolysis-derived lactate, highly produced during ischemic conditions, has been associated with tumor angiogenesis and wound healing. Lactate exerts its biological effects via G-protein-coupled receptor 81 (GPR81) in several tissues; however, its physiological functions and mechanisms of action in the retina remain poorly understood. Herein, we show that GPR81, localized predominantly in Müller cells, governs deep vascular complex formation during development and in ischemic retinopathy. Lactate-stimulated GPR81 Müller cells produce numerous angiogenic factors, including Wnt ligands and particularly Norrin, which contributes significantly in triggering inner retinal blood vessel formation. Conversely, GPR81-null mice retina shows reduced inner vascular network formation associated with low levels of Norrin (and Wnt ligands). Lactate accumulation during ischemic retinopathy selectively activates GPR81-extracellular signal-regulated kinase 1/2-Norrin signaling to accelerate inner retinal vascularization in wild-type animals, but not in the retina of GPR81-null mice. Altogether, we reveal that lactate via GPR81-Norrin participates in inner vascular network development and in restoration of the vasculature in response to injury. These findings suggest a new potential therapeutic target to alleviate ischemic diseases.
Assuntos
Células Ependimogliais/patologia , Proteínas do Olho/metabolismo , Isquemia/patologia , Proteínas do Tecido Nervoso/metabolismo , Receptores Acoplados a Proteínas G/fisiologia , Doenças Retinianas/patologia , Neovascularização Retiniana/patologia , Vasos Retinianos/patologia , Proteínas Wnt/metabolismo , Animais , Células Ependimogliais/metabolismo , Proteínas do Olho/genética , Isquemia/etiologia , Isquemia/metabolismo , Ácido Láctico/metabolismo , Camundongos , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Doenças Retinianas/etiologia , Doenças Retinianas/metabolismo , Neovascularização Retiniana/etiologia , Neovascularização Retiniana/metabolismo , Vasos Retinianos/metabolismo , Proteínas Wnt/genéticaRESUMO
Interleukin-1ß (IL-1ß) binds to the IL-1 receptor (IL-1R) and is a key cytokine mediator of inflammasome activation. IL-1ß signaling leads to parturition in preterm birth (PTB) and contributes to the retinal vaso-obliteration characteristic of oxygen-induced retinopathy (OIR) of premature infants. Therapeutics targeting IL-1ß and IL-1R are approved to treat rheumatoid arthritis; however, all are large proteins with clinical limitations including immunosuppression, due in part to inhibition of NF-κB signaling, which is required for immuno-vigilance and cytoprotection. The all-D-amino acid peptide 1 (101.10, H-d-Arg-d-Tyr-d-Thr-d-Val-d-Glu-d-Leu-d-Ala-NH2) is an allosteric IL-1R modulator, which exhibits functional selectivity and conserves NF-κB signaling while inhibiting other IL-1-activated pathways. Peptide 1 has proven effective in experimental models of PTB and OIR. Seeking understanding of the structural requirements for the activity and biased signaling of 1, a panel of twelve derivatives was synthesized employing the various stereochemical isomers of α-amino-γ-lactam (Agl) and α-amino-ß-hydroxy-γ-lactam (Hgl) residues to constrain the D-Thr-D-Val dipeptide residue. Using circular dichroism spectroscopy, the peptide conformation in solution was observed to be contingent on Agl, Hgl, and Val stereochemistry. Moreover, the lactam mimic structure and configuration influenced biased IL-1 signaling in an in vitro panel of cellular assays as well as in vivo activity in murine models of PTB and OIR. Remarkably, all Agl and Hgl analogs of peptide 1 did not inhibit NF-κB signaling but blocked other pathways, such as JNK and ROCK2 phosphorylation contingent on structure and configuration. Efficacy in preventing preterm labor correlated with a capacity to block IL-1ß-induced IL-1ß synthesis. Furthermore, the importance of inhibition of JNK and ROCK2 phosphorylation for enhanced activity was highlighted for prevention of vaso-obliteration in the OIR model. Taken together, lactam mimic structure and stereochemistry strongly influenced conformation and biased signaling. Selective modulation of IL-1 signaling was proven to be particularly beneficial for curbing inflammation in models of preterm labor and retinopathy of prematurity (ROP). A class of biased ligands has been created with potential to serve as selective probes for studying IL-1 signaling in disease. Moreover, the small peptide mimic prototypes are promising leads for developing immunomodulatory therapies with easier administration and maintenance of beneficial effects of NF-κB signaling.
RESUMO
Hemostatic fabrics are most commonly used in baseline emergency treatment; however, the unnecessary blood loss due to the excessive blood absorption by traditional superhydrophilic fabrics is overlooked. Herein, for the first time, superhydrophobic/superhydrophilic Janus fabrics (superhydrophobic on one side and superhydrophilic on the other) are proposed: the superhydrophilic part absorbs water in the blood to expedite the clotting while the superhydrophobic part prevents blood from further permeating. Compared with the common counterparts, effective bleeding control with reducing blood loss more than 50% can be achieved while the breathability largely remain by using Janus fabrics. The proposed prototypes can even prolong the survival time in the rat model with serious bleeding. This strategy for reducing blood loss via simply tuning wettability is promising for the practical applications.