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OBJECTIVE: ASPP1 (apoptosis stimulating of p53 protein 1) is critical in regulating cell apoptosis as a cofactor of p53 to promote its transcriptional activity in the nucleus. However, whether cytoplasmic ASPP1 affects p53 nuclear trafficking and its role in cardiac diseases remains unknown. This study aims to explore the mechanism by which ASPP1 modulates p53 nuclear trafficking and the subsequent contribution to cardiac ischemia/reperfusion (I/R) injury. METHODS AND RESULTS: The immunofluorescent staining showed that under normal condition ASPP1 and p53 colocalized in the cytoplasm of neonatal mouse ventricular cardiomyocytes, while they were both upregulated and translocated to the nuclei upon hypoxia/reoxygenation treatment. The nuclear translocation of ASPP1 and p53 was interdependent, as knockdown of either ASPP1 or p53 attenuated nuclear translocation of the other one. Inhibition of importin-ß1 resulted in the cytoplasmic sequestration of both p53 and ASPP1 in neonatal mouse ventricular cardiomyocytes with hypoxia/reoxygenation stimulation. Overexpression of ASPP1 potentiated, whereas knockdown of ASPP1 inhibited the expression of Bax (Bcl2-associated X), PUMA (p53 upregulated modulator of apoptosis), and Noxa, direct apoptosis-associated targets of p53. ASPP1 was also increased in the I/R myocardium. Cardiomyocyte-specific transgenic overexpression of ASPP1 aggravated I/R injury as indicated by increased infarct size and impaired cardiac function. Conversely, knockout of ASPP1 mitigated cardiac I/R injury. The same qualitative data were observed in neonatal mouse ventricular cardiomyocytes exposed to hypoxia/reoxygenation injury. Furthermore, inhibition of p53 significantly blunted the proapoptotic activity and detrimental effects of ASPP1 both in vitro and in vivo. CONCLUSIONS: Binding of ASPP1 to p53 triggers their nuclear cotranslocation via importin-ß1 that eventually exacerbates cardiac I/R injury. The findings imply that interfering the expression of ASPP1 or the interaction between ASPP1 and p53 to block their nuclear trafficking represents an important therapeutic strategy for cardiac I/R injury.
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Proteínas Adaptadoras de Transdução de Sinal , Traumatismo por Reperfusão , Proteína Supressora de Tumor p53 , Animais , Camundongos , Apoptose/fisiologia , Hipóxia/metabolismo , Isquemia/metabolismo , Carioferinas , Miócitos Cardíacos/metabolismo , Traumatismo por Reperfusão/metabolismo , Proteína Supressora de Tumor p53/genética , Proteínas Adaptadoras de Transdução de Sinal/genéticaRESUMO
Immune system imbalances contribute to the pathogenesis of several different diseases, and immunotherapy shows great therapeutic efficacy against tumours and infectious diseases with immune-mediated derivations. In recent years, molecules targeting the programmed cell death protein 1 (PD-1) immune checkpoint have attracted much attention, and related signalling pathways have been studied clearly. At present, several inhibitors and antibodies targeting PD-1 have been utilized as anti-tumour therapies. However, increasing evidence indicates that PD-1 blockade also has different degrees of adverse side effects, and these new explorations into the therapeutic safety of PD-1 inhibitors contribute to the emerging concept that immune normalization, rather than immune enhancement, is the ultimate goal of disease treatment. In this review, we summarize recent advancements in PD-1 research with regard to immune normalization and targeted therapy.
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Inibidores de Checkpoint Imunológico , Neoplasias , Receptor de Morte Celular Programada 1 , Humanos , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Neoplasias/imunologia , Neoplasias/terapia , Neoplasias/tratamento farmacológico , Inibidores de Checkpoint Imunológico/uso terapêutico , Inibidores de Checkpoint Imunológico/farmacologia , Animais , Imunoterapia/métodos , Transdução de Sinais/efeitos dos fármacos , Terapia de Alvo MolecularRESUMO
In this work, a microfluidic immunosensor chip was developed by incorporating microfluidic technology with electrochemiluminescence (ECL) for sensitive detection of human epidermal growth factor receptor-2 (HER2). The immunosensor chip can achieve robust reproducibility in mass production by integrating multiple detection units in a series. Notably, nanoscale materials can be better adapted to microfluidic systems, greatly enhancing the accuracy of the immunosensor chip. Ag@Au NCs closed by glutathione (GSH) were introduced in the ECL microfluidic immunosensor system with excellent and stable ECL performance. The synthesized CeO2-Au was applied as a coreaction promoter in the ECL signal amplification system, which made the result of HER2 detection more reliable. In addition, the designed microfluidic immunosensor chip integrated the biosensing system into a microchip, realizing rapid and accurate detection of HER2 by its high throughput and low usage. The developed short peptide ligand NARKFKG (NRK) achieved an effective connection between the antibody and nanocarrier for improving the detection efficiency of the sensor. The immunosensor chip had better storage stability and sensitivity than traditional detection methods, with a wide detection range from 10 fg·mL-1 to 100 ng·mL-1 and a low detection limit (LOD) of 3.29 fg·mL-1. In general, a microfluidic immunosensor platform was successfully constructed, providing a new idea for breast cancer (BC) clinical detection.
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Técnicas Biossensoriais , Técnicas Eletroquímicas , Eletrodos , Ouro , Medições Luminescentes , Nanopartículas Metálicas , Receptor ErbB-2 , Prata , Humanos , Receptor ErbB-2/análise , Receptor ErbB-2/imunologia , Nanopartículas Metálicas/química , Técnicas Eletroquímicas/métodos , Prata/química , Técnicas Biossensoriais/métodos , Ouro/química , Imunoensaio/métodos , Técnicas Analíticas Microfluídicas/instrumentação , Limite de Detecção , Cério/químicaRESUMO
Cardiovascular disease is the main factor contributing to the global burden of diseases, and the cardiotoxicity caused by anticancer drugs is an essential component that cannot be ignored. With the development of anticancer drugs, the survival period of cancer patients is prolonged; however, the cardiotoxicity caused by anticancer drugs is becoming increasingly prominent. Currently, cardiovascular disease has emerged as the second leading cause of mortality among long-term cancer survivors. Anticancer drug-induced cardiotoxicity has become a frontier and hot topic. The discovery of epigenetics has given the possibility of environmental changes in gene expression, protein synthesis, and traits. It has been found that epigenetics plays a pivotal role in promoting cardiovascular diseases, such as heart failure, coronary heart disease, and hypertension. In recent years, increasing studies have underscored the crucial roles played by epigenetics in anticancer drug-induced cardiotoxicity. Here, we provide a comprehensive overview of the role and mechanisms of epigenetics in anticancer drug-induced cardiotoxicity.
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AIM: To assess whether sodium-glucose cotransporter-2 (SGLT2) inhibitors reduce myocardial infarction (MI) incidence in patients with or without type 2 diabetes. METHODS: PubMed, Embase, Web of Science, the Cochrane library, and https://ClinicalTrials.gov were searched up to 7 May 2022. Randomized controlled trials (RCTs) and cohort studies reporting the effects of SGLT2 inhibitor treatment on MI incidence were included. Relative risks (RRs) with a 95% confidence interval (CI) for MI incidence were extracted and pooled. Subgroup analysis and meta-regression were performed to explore the heterogeneity. RESULTS: This meta-analysis included 54 RCTs and 32 cohort studies, with data from six SGLT2 inhibitors and 3 394 423 individuals. In the overall analysis, SGLT2 inhibitors significantly reduced MI incidence in RCTs (RR 0.9, 95% CI 0.84-0.96) and cohort studies (RR 0.89, 95% CI 0.83-0.94). In RCTs, the results of the subgroup analysis revealed no significant alterations in outcomes based on different SGLT2 inhibitor types, control drug types, cardiovascular disease (CVD) status and sources of outcome extraction (p for interaction >0.05). In cohort studies, the presence or absence of CVD led to similar effects of SGLT2 inhibitors on decreasing MI incidence (p for interaction = 0.179). However, variations in results were observed based on the type of control group in cohort studies (p for interaction = 0.036). Meta-regression results did not reveal an association between baseline cardiovascular risk factors, follow-up length, or MI incidence. CONCLUSIONS: In both RCTs and cohort studies, SGLT2 inhibitors reduced MI incidence. The cardioprotective effects of SGLT2 inhibitors were observed in patients with and without a history of CVD.
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Diabetes Mellitus Tipo 2 , Infarto do Miocárdio , Inibidores do Transportador 2 de Sódio-Glicose , Humanos , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/epidemiologia , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/prevenção & controle , Infarto do Miocárdio/induzido quimicamente , Glucose/uso terapêutico , SódioRESUMO
AIMS: To evaluate the performance of chat generative pretrained transformer (ChatGPT) in key domains of clinical pharmacy practice, including prescription review, patient medication education, adverse drug reaction (ADR) recognition, ADR causality assessment and drug counselling. METHODS: Questions and clinical pharmacist's answers were collected from real clinical cases and clinical pharmacist competency assessment. ChatGPT's responses were generated by inputting the same question into the 'New Chat' box of ChatGPT Mar 23 Version. Five licensed clinical pharmacists independently rated these answers on a scale of 0 (Completely incorrect) to 10 (Completely correct). The mean scores of ChatGPT and clinical pharmacists were compared using a paired 2-tailed Student's t-test. The text content of the answers was also descriptively summarized together. RESULTS: The quantitative results indicated that ChatGPT was excellent in drug counselling (ChatGPT: 8.77 vs. clinical pharmacist: 9.50, P = .0791) and weak in prescription review (5.23 vs. 9.90, P = .0089), patient medication education (6.20 vs. 9.07, P = .0032), ADR recognition (5.07 vs. 9.70, P = .0483) and ADR causality assessment (4.03 vs. 9.73, P = .023). The capabilities and limitations of ChatGPT in clinical pharmacy practice were summarized based on the completeness and accuracy of the answers. ChatGPT revealed robust retrieval, information integration and dialogue capabilities. It lacked medicine-specific datasets as well as the ability for handling advanced reasoning and complex instructions. CONCLUSIONS: While ChatGPT holds promise in clinical pharmacy practice as a supplementary tool, the ability of ChatGPT to handle complex problems needs further improvement and refinement.
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Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Serviço de Farmácia Hospitalar , Farmácia , Humanos , Farmacêuticos , Competência Clínica , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controleRESUMO
Beijing You Chicken, a valuable local chicken breed from Beijing, China, was once listed as an endangered breed. From the point of view of conservation, the preservation of this breed is an important task for the local researchers. Semen cryopreservation is a popular method to maintain valuable species. However, during cryopreservation, semen is susceptible to oxidative damage. Melatonin is a potent antioxidant and free radical scavenger, so it has been selected to improve the efficiency of sperm cryopreservation. In this study, the chicken semen was treated with different concentrations of melatonin in the cryopreservation solution. The results showed that melatonin at concentrations of 10-3 M and 10-5 M significantly improved sperm progressive motility and total motility, respectively, compared to the control (P < 0.05). Melatonin at 10-3 M also significantly improved the plasma membrane and acrosome integrity of spermatozoa compared to the control. The mechanisms are that melatonin significantly reduces the level of ROS and preserves sperm mitochondrial membrane potential. Most importantly, the melatonin-treated cryopreserved chicken sperm after artificial insemination significantly increased the hatching rate of chicks compared to the control (p < 0.05). The results show that melatonin has a positive effect on the quality of the cryopreserved spermatozoa. These results provide the theoretical and practical basis for using melatonin to improve Beijing You Chicken conservation, and they may also be applicable to poultry as a whole.
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Melatonina , Preservação do Sêmen , Masculino , Animais , Galinhas , Melatonina/farmacologia , Criopreservação/métodos , Sêmen , Pequim , Crioprotetores/farmacologia , Crioprotetores/metabolismo , Preservação do Sêmen/veterinária , Preservação do Sêmen/métodos , Espermatozoides , Motilidade dos Espermatozoides , Análise do SêmenRESUMO
OBJECTIVE: This meta-analysis aims to investigate the effect of the Hospital Elder Life Program (HELP) on the incidence of delirium, delirium scores, length of hospital stay, and incidence of falls. METHODS: Four databases (PubMed, Embase, Cochrane Library, and Web of Science) were searched from inception until January 18, 2024. The search specifically targeted randomized controlled trials (RCTs). Two independent researchers conducted literature screening, quality assessment, and data extraction. The meta-analysis was performed using Review Manager 5.4.1 and Stata 15.1 software. RESULTS: The final analysis included a total of 9 RCTs with 2583 patients. The findings from the meta-analysis indicated that HELP was found to considerably reduce the incidence of delirium and the length of hospital stay when compared to the control group. Nevertheless, no statistically significant differences were observed between the two groups in terms of delirium scores and fall rates. CONCLUSION: In this meta-analysis, HELP can effectively reduce the incidence of delirium and lead to a shorter hospital stay.
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Acidentes por Quedas , Delírio , Tempo de Internação , Delírio/prevenção & controle , Delírio/epidemiologia , Humanos , Incidência , Tempo de Internação/estatística & dados numéricos , Idoso , Acidentes por Quedas/prevenção & controle , Ensaios Clínicos Controlados Aleatórios como Assunto , Ensaios Clínicos como AssuntoRESUMO
Plants have evolved complex mechanisms to reprogram growth in response to drought stress. In herbaceous perennial plant species, the rhizome, which is normally an organ for propagation and food storage, can also support plant growth in stressful environments, and allows the plant to perennate and survive stress damage. However, the mechanisms that regulate rhizome growth in perennial herbs during abiotic stresses are unknown. Here, we identified a chrysanthemum (Chrysanthemum morifolium) DEAD-box RNA helicase gene, CmRH56, that is specifically expressed in the rhizome shoot apex. Knock down of CmRH56 transcript levels decreased the number of rhizomes and enhanced drought stress tolerance. We determined that CmRH56 represses the expression of a putative gibberellin (GA) catabolic gene, GA2 oxidase6 (CmGA2ox6). Exogenous GA treatment and silencing of CmGA2ox6 resulted in more rhizomes. These results demonstrate that CmRH56 suppresses rhizome outgrowth under drought stress conditions by blocking GA biosynthesis.
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Chrysanthemum , Secas , Chrysanthemum/genética , Chrysanthemum/metabolismo , RNA Helicases DEAD-box/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Rizoma/genética , Rizoma/metabolismo , Estresse FisiológicoRESUMO
Interleukin-17A (IL-17), a potent proinflammatory cytokine, has been shown to participate in cardiac electrical disorders. Diabetes mellitus is an independent risk factor for ventricular arrhythmia. In this study, we investigated the role of IL-17 in ventricular arrhythmia of diabetic mice. Diabetes was induced in both wild-type and IL-17 knockout mice by intraperitoneal injection of streptozotocin (STZ). High-frequency electrical stimuli were delivered into the right ventricle to induce ventricular arrhythmias. We showed that the occurrence rate of ventricular tachycardia was significantly increased in diabetic mice, which was attenuated by IL-17 knockout. We conducted optical mapping on perfused mouse hearts and found that cardiac conduction velocity (CV) was significantly decreased, and action potential duration (APD) was prolonged in diabetic mice, which were mitigated by IL-17 knockout. We performed whole-cell patch clamp recordings from isolated ventricular myocytes, and found that the densities of Ito, INa and ICa,L were reduced, the APDs at 50% and 90% repolarization were increased, and early afterdepolarization (EAD) was markedly increased in diabetic mice. These alterations were alleviated by the knockout of IL-17. Moreover, knockout of IL-17 alleviated the downregulation of Nav1.5 (the pore forming subunit of INa), Cav1.2 (the main component subunit of ICa,L) and KChIP2 (potassium voltage-gated channel interacting protein 2, the regulatory subunit of Ito) in the hearts of diabetic mice. The expression of NF-κB was significantly upregulated in the hearts of diabetic mice, which was suppressed by IL-17 knockout. In neonatal mouse ventricular myocytes, knockdown of NF-κB significantly increased the expression of Nav1.5, Cav1.2 and KChIP2. These results imply that IL-17 may represent a potential target for the development of agents against diabetes-related ventricular arrhythmias.
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Diabetes Mellitus Experimental/metabolismo , Cardiomiopatias Diabéticas/metabolismo , Interleucina-17/metabolismo , NF-kappa B/metabolismo , Remodelação Ventricular , Animais , Western Blotting , Técnicas de Inativação de Genes , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Técnicas de Patch-Clamp , Reação em Cadeia da Polimerase em Tempo RealRESUMO
PURPOSE: The posterior tibial slope (PTS) is considered a risk factor for anterior cruciate ligament (ACL) injury. However, the influence of PTS on graft failure following ACL reconstruction remains relatively unknown. Therefore, this systematic review was conducted to investigate whether PTS could be a potential risk factor for graft failure after ACL reconstruction. METHODS: PubMed, EMBASE, Cochrane Library, Web of Science, China National Knowledge Infrastructure Database, and Wanfang Database were comprehensively searched from inception to March 31, 2021. Observational studies reporting the associations of medial tibial plateau slope (MTPS) or lateral tibial plateau slope (LTPS) with graft failure after ACL reconstruction were evaluated. RESULTS: Twenty studies involving 12 case-control studies, 4 retrospective studies and 4 cross-sectional studies including 5326 patients met the final inclusion criteria. The high heterogeneity and the characteristics of nonrandomized controlled trials limited data synthesis. Fifteen of the 20 included studies detected a significant association between increased PTS and ACL graft failure, while 5 studies concluded that increased PTS was not associated with ACL graft failure. Ten studies suggested that MTPS is associated with ACL graft failure, and six studies suggested that LTPS is associated with ACL graft failure. The mean MTPS values for nonfailure group ranged from 3.5° ± 2.5° to 14.4° ± 2.8°. For the graft failure group, MTPS ranged from 4.71° ± 2.41° to 17.2° ± 2.2°. The mean LTPS values for nonfailure group ranged from 2.9° ± 2.1° to 11.9° ± 3.0°. For the graft failure group, LTPS ranged from 5.5° ± 3.0° to 13.3° ± 3.0°. The reported PTS values that caused ACL graft failure was greater than 7.4° to 17°. CONCLUSION: Based on the current clinical evidence, increased PTS is associated with a higher risk of ACL graft failure after ACL reconstruction. Despite various methods of measuring PTS have high reliability, there is still vast disagreement in the actual value of PTS. LEVEL OF EVIDENCE: IV.
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Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior , Lesões do Ligamento Cruzado Anterior/complicações , Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior/efeitos adversos , Reconstrução do Ligamento Cruzado Anterior/métodos , Estudos Transversais , Humanos , Articulação do Joelho/cirurgia , Reprodutibilidade dos Testes , Estudos Retrospectivos , Tíbia/cirurgiaRESUMO
Mechanical environments were associated with alterations in bone metabolism. Ion channels present on bone cells are indispensable for bone metabolism and can be directly or indirectly activated by mechanical stimulation. This review aimed to discuss the literature reporting the mechanical regulatory effects of ion channels on bone cells and bone tissue. An electronic search was conducted in PubMed, Embase and Web of Science. Studies about mechanically induced alteration of bone cells and bone tissue by ion channels were included. Ion channels including TRP family channels, Ca2+ release-activated Ca2+ channels (CRACs), Piezo1/2 channels, purinergic receptors, NMDA receptors, voltage-sensitive calcium channels (VSCCs), TREK2 potassium channels, calcium- and voltage-dependent big conductance potassium (BKCa) channels, small conductance, calcium-activated potassium (SKCa) channels and epithelial sodium channels (ENaCs) present on bone cells and bone tissue participate in the mechanical regulation of bone development in addition to contributing to direct or indirect mechanotransduction such as altered membrane potential and ionic flux. Physiological (beneficial) mechanical stimulation could induce the anabolism of bone cells and bone tissue through ion channels, but abnormal (harmful) mechanical stimulation could also induce the catabolism of bone cells and bone tissue through ion channels. Functional expression of ion channels is vital for the mechanotransduction of bone cells. Mechanical activation (opening) of ion channels triggers ion influx and induces the activation of intracellular modulators that can influence bone metabolism. Therefore, mechanosensitive ion channels provide new insights into therapeutic targets for the treatment of bone-related diseases such as osteopenia and aseptic implant loosening.
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Osso e Ossos/metabolismo , Canais Iônicos/metabolismo , Mecanotransdução Celular/fisiologia , Animais , Linhagem Celular , Humanos , Receptores Purinérgicos/metabolismoRESUMO
The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been significantly alleviated. However, long-term health effects and prevention strategy remain unresolved. Thus, it is essential to explore the pathophysiological mechanisms and intervention for SARS-CoV-2 infection. Emerging research indicates a link between COVID-19 and bile acids, traditionally known for facilitating dietary fat absorption. The bile acid ursodeoxycholic acid potentially protects against SARS-CoV-2 infection by inhibiting the farnesoid X receptor, a bile acid nuclear receptor. The activation of G-protein-coupled bile acid receptor, another membrane receptor for bile acids, has also been found to regulate the expression of angiotensin-converting enzyme 2, the receptor through which the virus enters human cells. Here, we review the latest basic and clinical evidence linking bile acids to SARS-CoV-2, and reveal their complicated pathophysiological mechanisms.
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The negative energy balance occurring in the periparturient period of cows will impede their health and postpartum performance. To target this issue, L-tryptophan was supplied to the prepartum cows. The results showed that L-tryptophan supplementation significantly increased the serum melatonin level and was accompanied with increases in SOD activity, IL-10 and colostrum IgA levels as well as decreases in MDA and IL-6 levels compared to the control cows. The incidence of postpartum diseases was significantly lower and the pregnancy rate was significantly higher in cows fed L-tryptophan than in the control group. A striking observation was that prepartum L-tryptophan supplementation not only improved the milk production but also the quality compared to the control cows. In general, supplementation with L-tryptophan in the prepartum period can improve the postpartum reproduction and lactation performance of cows to some extent.
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Senile osteoporosis is mainly caused by osteoblasts attenuation, which results in reduced bone mass and disrupted bone remodeling. Numerous studies have focused on the regulatory role of m6A modification in osteoporosis; however, most of the studies have investigated the differentiation of bone marrow mesenchymal stem cells (BMSCs), while the direct regulatory mechanism of m6A on osteoblasts remains unknown. This study revealed that the progression of senile osteoporosis is closely related to the downregulation of m6A modification and methyltransferase-like 3 (METTL3). Overexpression of METTL3 inhibits osteoblast aging. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) revealed that METTL3 upregulates the stability of Hspa1a mRNA, thereby inhibiting osteoblast aging. Moreover, the results demonstrated that METTL3 enhances the stability of Hspa1a mRNA via m6A modification to regulate osteoblast aging. Notably, YTH N6-methyladenosine RNA binding protein 2 (YTHDF2) participates in stabilizing Hspa1a mRNA in the METTL3-mediated m6A modification process, rather than the well-known degradation function. Mechanistically, METTL3 increases the stability of Hspa1a mRNA in a YTHDF2-dependent manner to inhibit osteoblast aging. Our results confirmed the significant role of METTL3 in osteoblast aging and suggested that METTL3 could be a potential therapeutic target for senile osteoporosis.
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Since the global demanding of natural melatonin-enriched milk has been significantly increased in the populations of children and elder, the accurate and quick melatonin detection from milk is urgently required. Thus, the regular methods no longer satisfy this requirement. In the current study, we reported a novel method to extract melatonin from milk for liquid chromatography-tandem mass spectrometry melatonin detection. This novel method was to use cold methanol (-20â) to precipitate proteins and fat in milk with one step to extract melatonin. Compared to the regular methods, it was devoid of procedures of sample drying, solid phase extraction and sample reconstitution. It could short the extraction time from the regularly 150 min to 60 min/per 24 milk samples. We believe that this novel method provides a possibility to detect large scale of milk samples in relatively short time with more efficiency and less cost compared to the regular method.
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Melatonina , Leite , Animais , Cromatografia Líquida , Extração em Fase Sólida , Espectrometria de Massas em TandemRESUMO
BACKGROUND: Methane (CH4) is a major greenhouse gas, and ruminants are one of the sources of CH4 which is produced by the rumen microbiota. Modification of the rumen microbiota compositions will impact the CH4 production. In this study, the effects of melatonin on methane production in cows were investigated both in the in vitro and in vivo studies. RESULTS: Melatonin treatment significantly reduced methane production in both studies. The cows treated with melatonin reduced methane emission from their respiration by approximately 50%. The potential mechanisms are multiple. First, melatonin lowers the volatile fatty acids (VFAs) production in rumen and reduces the raw material for CH4 synthesis. Second, melatonin not only reduces the abundance of Methanobacterium which are responsible for generating methane but also inhibits the populations of protozoa to break the symbiotic relationship between Methanobacterium and protozoa in rumen to further lowers the CH4 production. The reduced VFA production is not associated with food intake, and it seems also not to jeopardize the nutritional status of the cows. This was reflected by the increased milk lipid and protein contents in melatonin treated compared to the control cows. It is likely that the energy used to synthesize methane is saved to compensate the reduced VFA production. CONCLUSION: This study enlightens the potential mechanisms by which melatonin reduces rumen methane production in dairy cows. Considering the greenhouse effects of methane on global warming, these findings provide valuable information using different approaches to achieve low carbon dairy farming to reduce the methane emission. Video Abstract.
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Melatonina , Feminino , Animais , Bovinos , Melatonina/farmacologia , Rúmen , Agricultura , Carbono , MetanoRESUMO
In the current study, we explored the relationship between melatonin and lactose synthesis in in vivo and in vitro conditions. We found that long-term melatonin feeding to the dairy cows significantly reduced the milk lactose content in a dose dependent manner. This lactose reduction was not associated with a negative energy balance, since melatonin treatment did not alter the fat, glucose, or protein metabolisms of the cows. To identify the potential molecular mechanisms, the cow's mammary epithelial cells were cultured for gene expression analysis. The results showed that the effect of melatonin on lactose reduction was mediated by its receptor MT1. MT1 activation downregulated the mRNA expression of the prolactin receptor gene (PRLR), which then suppressed the gene expression of SLC35B1. SLC35B1 is a galactose transporter and is responsible for the transportation of galactose to Golgi apparatus for lactose synthesis. Its suppression reduced the lactose synthesis and the milk lactose content. The discovery of this signal transduction pathway of melatonin on lactose synthesis provides a novel aspect of melatonin's effect on carbohydrate metabolism in cows and maybe also in other mammals, including humans.