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Designing electrocatalysts for seawater splitting remains challenging. A Ru-Co alloy supported by an N-doped carbon substrate catalyst has been designed using etching and a low-temperature treatment method. Studies show that the superior performance of this catalyst is related to the hollow-structured N-doped carbon frame and surface reconstruction of the Ru-Co alloy.
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Wound healing is an intricate and fine regulatory process. In diabetic patients, advanced glycation end products (AGEs), excessive reactive oxygen species (ROS), biofilm formation, persistent inflammation, and angiogenesis regression contribute to delayed wound healing. Epigenetics, the fast-moving science in the 21st century, has been up to date and associated with diabetic wound repair. In this review, we go over the functions of epigenetics in diabetic wound repair in retrospect, covering transcriptional and posttranscriptional regulation. Among these, we found that histone modification is widely involved in inflammation and angiogenesis by affecting macrophages and endothelial cells. DNA methylation is involved in factors regulation in wound repair but also affects the differentiation phenotype of cells in hyperglycemia. In addition, noncodingRNA regulation and RNA modification in diabetic wound repair were also generalized. The future prospects for epigenetic applications are discussed in the end. In conclusion, the study suggests that epigenetics is an integral regulatory mechanism in diabetic wound healing.
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Background: Bladder cancer is a common urinary tract malignancy. Minimally invasive radical cystectomy has shown oncological outcomes comparable to the conventional open surgery and with advantages over the open procedure. However, outcomes of the two main minimally invasive procedures, robot-assisted and pure laparoscopic, have yet to be compared. This study aimed to compare in-hospital outcomes between these two techniques performed for patients with bladder cancer. Methods: This population-based, retrospective study included hospitalized patients aged ≥ 50 years with a primary diagnosis of bladder cancer who underwent robot-assisted or pure laparoscopic radical cystectomy. All patient data were extracted from the US National Inpatient Sample (NIS) database 2008-2018 and were analyzed retrospectively. Primary outcomes were in-hospital mortality, prolonged length of stay (LOS), and postoperative complications. Results: The data of 3284 inpatients (representing 16,288 US inpatients) were analyzed. After adjusting for confounders, multivariable analysis revealed that patients who underwent robot-assisted radical cystectomy had a significantly lower risk of in-hospital mortality (adjusted OR [aOR], 0.50, 95% CI: 0.28-0.90) and prolonged LOS (aOR, 0.63, 95% CI: 0.49-0.80) than those undergoing pure laparoscopic cystectomy. Patients who underwent robot-assisted radical cystectomy had a lower risk of postoperative complications (aOR, 0.69, 95% CI: 0.54-0.88), including bleeding (aOR, 0.73, 95% CI: 0.54-0.99), pneumonia (aOR, 0.49, 95% CI: 0.28-0.86), infection (aOR, 0.55, 95% CI: 0.36-0.85), wound complications (aOR, 0.33, 95% CI: 0.20-0.54), and sepsis (aOR, 0.49, 95% CI: 0.34-0.69) compared to those receiving pure laparoscopic radical cystectomy. Conclusions: Patients with bladder cancer, robot-assisted radical cystectomy is associated with a reduced risk of unfavorable short-term outcomes, including in-hospital mortality, prolonged LOS, and postoperative complications compared to pure laparoscopic radical cystectomy.
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Liquid-liquid phase separation (LLPS) is a novel principle for interpreting precise spatiotemporal coordination in living cells through biomolecular condensate (BMC) formation via dynamic aggregation. LLPS changes individual molecules into membrane-free, droplet-like BMCs with specific functions, which coordinate various cellular activities. The formation and regulation of LLPS are closely associated with oncogenesis, tumor progressions and metastasis, the specific roles and mechanisms of LLPS in tumors still need to be further investigated at present. In this review, we comprehensively summarize the conditions of LLPS and identify mechanisms involved in abnormal LLPS in cancer processes, including tumor growth, metastasis, and angiogenesis from the perspective of cancer hallmarks. We have also reviewed the clinical applications of LLPS in oncologic areas. This systematic summary of dysregulated LLPS from the different dimensions of cancer hallmarks will build a bridge for determining its specific functions to further guide basic research, finding strategies to intervene in LLPS, and developing relevant therapeutic approaches.
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Neoplasias , Separação de Fases , Humanos , Transformação Celular Neoplásica , Carcinogênese , OncologiaRESUMO
Introduction: Epidural electrical stimulation (EES) has been shown to improve motor dysfunction after spinal cord injury (SCI) by activating residual locomotor neural networks. However, the stimulation current often spreads excessively, leading to activation of non-target muscles and reducing the accuracy of stimulation regulation. Objectives: Near-infrared nerve stimulation (nINS) was combined with EES to explore its regulatory effect on lower limb muscle activity in spinal-cord-transected rats. Methods: In this study, stimulation electrodes were implanted into the rats' L3-L6 spinal cord segment with T8 cord transected. Firstly, a series of EES parameters (0.2-0.6 mA and 20-60 Hz) were tested to determine those that specifically regulate the tibialis anterior (TA) and medial gastrocnemius (MG). Subsequently, to determine the effect of combined optical and electrical stimulation, near-infrared laser with a wavelength of 808 nm was used to irradiate the L3-L6 spinal cord segment while EES was performed. The amplitude of electromyography (EMG), the specific activation intensity of the target muscle, and the minimum stimulus current intensity to induce joint movement (motor threshold) under a series of optical stimulation parameters (power: 0.0-2.0 W; pulse width: 0-10 ms) were investigated and analyzed. Results: EES stimulation with 40 Hz at the L3 and L6 spinal cord segments specifically activated TA and MG, respectively. High stimulation intensity (>2 × motor threshold) activated non-target muscles, while low stimulation frequency (<20 Hz) produced intermittent contraction. Compared to electrical stimulation alone (0.577 ± 0.081 mV), the combined stimulation strategy could induce stronger EMG amplitude of MG (1.426 ± 0.365 mV) after spinal cord injury (p < 0.01). The combined application of nINS effectively decreased the EES-induced motor threshold of MG (from 0.237 ± 0.001 mA to 0.166 ± 0.028 mA, p < 0.001). Additionally, the pulse width (PW) of nINS had a slight impact on the regulation of muscle activity. The EMG amplitude of MG only increased by ~70% (from 3.978 ± 0.240 mV to 6.753 ± 0.263 mV) when the PW increased by 10-fold (from 1 to 10 ms). Conclusion: The study demonstrates the feasibility of epidural combined electrical and optical stimulation for highly specific regulation of muscle activity after SCI, and provides a new strategy for improving motor dysfunction caused by SCI.
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Niemann-Pick C1-like 1 (NPC1L1) is essential for intestinal cholesterol absorption. Together with the cholesterol-rich and Flotillin-positive membrane microdomain, NPC1L1 is internalized via clathrin-mediated endocytosis and transported to endocytic recycling compartment (ERC). When ERC cholesterol level decreases, NPC1L1 interacts with LIMA1 and moves back to plasma membrane. However, how cholesterol leaves ERC is unknown. Here, we find that, in male mice, intracellular bile acids facilitate cholesterol transport to other organelles, such as endoplasmic reticulum, in a non-micellar fashion. When cholesterol level in ERC is decreased by bile acids, the NPC1L1 carboxyl terminus that previously interacts with the cholesterol-rich membranes via the A1272LAL residues dissociates from membrane, exposing the Q1277KR motif for LIMA1 recruitment. Then NPC1L1 moves back to plasma membrane. This study demonstrates an intracellular cholesterol transport function of bile acids and explains how the substantial amount of cholesterol in NPC1L1-positive compartments is unloaded in enterocytes during cholesterol absorption.
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Colesterol , Proteínas de Membrana Transportadoras , Animais , Masculino , Camundongos , Transporte Biológico , Membrana Celular/metabolismo , Colesterol/metabolismo , Absorção Intestinal , Proteínas de Membrana Transportadoras/metabolismoRESUMO
Graph theory-based analysis describes the brain as a complex network. Only a few studies have examined modular composition and functional connectivity (FC) between modules in patients with spinal cord injury (SCI). Little is known about the longitudinal changes in hubs and topological properties at the modular level after SCI and treatment. We analyzed differences in FC and nodal metrics reflecting modular interaction to investigate brain reorganization after SCI-induced compensation and neurotrophin-3 (NT3)-chitosan-induced regeneration. Mean inter-modular FC and participation coefficient of areas related to motor coordination were significantly higher in the treatment animals than in the SCI-only ones at the late stage. The magnocellular part of the red nucleus may reflect the best difference in brain reorganization after SCI and therapy. Treatment can enhance information flows between regions and promote the integration of motor functions to return to normal. These findings may reveal the information processing of disrupted network modules.
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Owing to its biotoxicity and inductive effect on photochemical pollution, atmospheric peroxyacetyl nitrate (PAN), which is a typical product of atmospheric photochemical reactions, has attracted much research attention. However, to the best of our knowledge, few comprehensive studies have been conducted on the seasonal variation and key influencing factors of PAN concentrations in southern China. In this study, PAN, ozone (O3), precursor volatile organic compound (VOC), and other pollutant concentrations were measured online for 1 year (from October 2021 to September 2022) in Shenzhen, a megacity in the Greater Bay Area of China. The average concentrations of PAN and peroxypropionyl nitrate (PPN) were 0.54 and 0.08 parts per billion (ppb), and the maximum hourly concentrations reached 10.32 and 1.01 ppb, respectively. The results of the generalized additive model (GAM) showed that the atmospheric oxidation capacity and precursor concentration were the most important factors affecting the PAN concentration. According to the steady-state model, the average cumulative contribution to the peroxyacetyl (PA) radical formation rate by six major carbonyl compounds was calculated at 4.2 × 106 molecules cm-3 s-1, and acetaldehyde (63.0 %) and acetone (13.9 %) contributed the most. Furthermore, the photochemical-age-based parameterization method was used to analyze the source contributions of carbonyl compounds and PA radicals. The results showed that although the primary anthropogenic (40.2 %), biogenic (27.8 %), and secondary anthropogenic (16.4 %) sources were the most important contributors of PA radicals, the biogenic and secondary anthropogenic source contributions both increased considerably in summer, and the cumulative proportion of both sources reached ~70 % in July. In addition, a comparison of PAN pollution processes in different seasons revealed that in summer and winter, the PAN concentration was predominantly limited by precursors and meteorological parameters, such as light intensity, respectively.
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Poluentes Atmosféricos , Ozônio , Compostos Orgânicos Voláteis , Estações do Ano , Poluentes Atmosféricos/análise , China , Ozônio/análise , Compostos Orgânicos Voláteis/análise , Monitoramento AmbientalRESUMO
BACKGROUND: Lower plasma levels of LDL (low-density lipoprotein) cholesterol (LDL-C) can reduce the risk of atherosclerotic cardiovascular disease. The loss-of-function mutations in PCSK9 (proprotein convertase subtilisin/kexin type 9) have been known to associate with low LDL-C in many human populations. PCSK9 genetic variants in Chinese Uyghurs who are at high risk of atherosclerotic cardiovascular disease due to their dietary habits have not been reported. METHODS: The study involved the whole-exome and target sequencing of college students from Uyghur and other ethnic groups in Xinjiang, China, for the association of PCSK9 loss-of-function mutations with low plasma levels of LDL-C. The mechanisms by which the identified mutations affect the function of PCSK9 were investigated in cultured cells using biochemical and cell assays. The causal effects of the identified PCSK9 mutations on LDL-C levels were verified in mice injected with adeno-associated virus expressing different forms of PCSK9 and fed a high-cholesterol diet. RESULTS: We identified 2 PCSK9 mutations-E144K and C378W-in Chinese Uyghurs with low plasma levels of LDL-C. The E144K and C378W mutations impaired the maturation and secretion of the PCSK9 protein, respectively. Adeno-associated virus-mediated expression of E144K and C378W mutants in Pcsk9 KO (knockout) mice fed a high-cholesterol diet also hampered PCSK9 secretion into the serum, resulting in elevated levels of LDL receptor in the liver and reduced levels of LDL-C in the serum. CONCLUSIONS: Our study shows that E144K and C378W are PCSK9 loss-of-function mutations causing low LDL-C levels in mice and probably in humans as well.
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Aterosclerose , Doenças Cardiovasculares , Hipercolesterolemia , Humanos , Camundongos , Animais , Pró-Proteína Convertase 9/genética , LDL-Colesterol , Serina Endopeptidases/genética , Pró-Proteína Convertases/genética , Pró-Proteína Convertases/metabolismo , Receptores de LDL/genética , Receptores de LDL/metabolismo , Camundongos Knockout , Aterosclerose/genética , Aterosclerose/prevenção & controle , Aterosclerose/metabolismo , MutaçãoRESUMO
BACKGROUND: The aim of this study is to evaluate the impact of intraoperative allograft vascular flow on early kidney graft function. METHODS: A total of 159 patients underwent kidney transplantation from January 2017 to March 2022 at Linkou Chang Gung Memorial Hospital. Graft arterial and venous blood flow was measured separately with a transient time flowmeter (Transonic HT353; Transonic Systems, Inc, Ithaca, NY, United States) after ureteroneocystostomy. The early outcomes, including the postoperative creatinine level, were analyzed accordingly. RESULTS: There were 83 males and 76 females, with a mean age of 44.5 years. The mean graft arterial flow measured was 480.6 mL/min, and the mean venous flow was 506.2 mL/min. Delayed graft function (DGF) incidence was 36.5%, 32.5%, and 40.8% in total, living, and deceased donor groups, respectively. Living donor and deceased donor kidney transplantation were analyzed separately. In the DGF subgroup, there were lower graft venous flows, higher body mass index (BMI), and more male patients in the living kidney transplant group. Similarly, the deceased donor kidney transplantation group with delayed graft function tended to have higher body height, higher body weight, higher BMI, and more diabetes mellitus. The multivariate analysis showed that lower graft venous blood flow (odds ratio [OR] = 0.995, P = .008) and higher BMI (OR = 1.144, P = .042) were significantly correlated with delayed graft function in living donor kidney transplantations. In the deceased donor group, a multivariate analysis of risk factors showed that BMI had a significant correlation with delayed graft function (OR = 1.41, P = .039). CONCLUSIONS: Graft venous blood flow was significantly associated with delayed graft function in living donor kidney transplantation, and high BMI was correlated with DGF in all patients receiving kidney transplantation.
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Função Retardada do Enxerto , Sobrevivência de Enxerto , Feminino , Humanos , Masculino , Adulto , Função Retardada do Enxerto/etiologia , Função Retardada do Enxerto/epidemiologia , Rejeição de Enxerto/epidemiologia , Estudos Retrospectivos , Doadores de Tecidos , Doadores Vivos , Fatores de RiscoRESUMO
BACKGROUND: Hypoparathyroidism, which can be sporadic or a component of an inherited syndrome, is the most common cause of hypocalcemia. If hypocalcemia is accompanied by other electrolyte disturbances, such as hypokalemia and hypomagnesemia, then the cause, such as renal tubular disease, should be carefully identified. CASE SUMMARY: An 18-year-old female visited our clinic because of short stature and facial deformities, including typical phenotypes, such as low ear position, depression of the nasal bridge, small hands and feet, and loss of dentition. The lab results suggested normal parathyroid hormone but hypocalcemia. In addition, multiple electrolyte disturbances were found, including hypokalemia, hypocalcemia and hypomagnesemia. The physical signs showed a short fourth metatarsal bone of both feet. The X-ray images showed cortical thickening of long bones and narrowing of the medulla of the lumen. Cranial computed tomography indicated calcification in the bilateral basal ganglia. Finally, the genetic investigation showed a de novo heterogenous mutation of "FAM111A" (c. G1706A:p.R569H). Through a review of previously reported cases, the mutation was found to be the most common mutation site in Kenny-Caffey syndrome type 2 (KCS2) cases reported thus far (16/23, 69.6%). The mutation was slightly more prevalent in females than in males (11/16, 68.8%). Except for hypocalcemia, other clinical manifestations are heterogeneous. CONCLUSION: As a rare autosomal dominant genetic disease of hypoparathyroidism, the clinical manifestations of KCS2 are atypical and diverse. This girl presented with short stature, facial deformities and skeletal deformities. The laboratory results revealed hypocalcemia as the main electrolyte disturbance. Even though her family members showed normal phenotypes, gene detection was performed to find the mutation of the FAM111A gene and confirmed the diagnosis of KCS2.
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MicroRNAs , RNA Longo não Codificante , Neoplasias da Glândula Tireoide , Humanos , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Transdução de Sinais/genética , Neoplasias da Glândula Tireoide/genética , Fator de Crescimento Insulin-Like IIRESUMO
We report the discovery and detailed investigation of superconductivity in Mo4Ga20As. Mo4Ga20As crystallizes in a space group ofI4/m(No. 87), with the lattice parametersa= 12.86352 Å andc= 5.30031 Å. The resistivity, magnetization, and specific heat data reveal Mo4Ga20As to be a type-II superconductor withTc= 5.6 K. The upper and lower critical fields are estimated to be 2.78 T and 22.0 mT, respectively. In addition, electron-phonon coupling in Mo4Ga20As is possibly stronger than the BCS weak-coupling limit. First-principles calculations suggest the Fermi level being dominated by the Mo-4dand Ga-4porbitals.
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We propose a scheme to realize robust optical entanglement in cavity optomagnonics, where two optical whispering gallery modes (WGMs) couple to a magnon mode in a yttrium iron garnet (YIG) sphere. The beam-splitter-like and two-mode squeezing magnon-photon interactions can be realized simultaneously when the two optical WGMs are driven by external fields. Entanglement between the two optical modes is then generated via their coupling with magnons. By exploiting the destructive quantum interference between the bright modes of the interface, the effects of initial thermal occupations of magnons can be eliminated. Moreover, the excitation of the Bogoliubov dark mode is capable of protecting the optical entanglement from thermal heating effects. Therefore, the generated optical entanglement is robust against thermal noise and the requirement of cooling the magnon mode is relaxed. Our scheme may find applications in the study of magnon-based quantum information processing.
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Efficient and stable electrocatalysts are critically needed for the development of practical overall seawater splitting. The nanocomposite of RuCoBO has been rationally engineered to be an electrocatalyst that fits these criteria. The study has shown that a calcinated RuCoBO-based nanocomposite (Ru2Co1BO-350) exhibits an extremely high catalytic activity for H2 and O2 production in alkaline seawater (overpotentials of 14 mV for H2 evolution and 219 mV for O2 evolution) as well as a record low cell voltage (1.466 V@10 mA cm-2) and long-term stability (230 h @50 mA cm-2 and @100 mA cm-2) for seawater splitting. The results show that surface reconstruction of Ru2Co1BO-350 occurs during hydrogen evolution reaction and oxygen evolution reaction, which leads to the high activity and stability of the catalyst. The reconstructed surface is highly resistant to Cl- corrosion. The investigation suggests that a new strategy exists for the design of high-performance Ru-based electrocatalysts that resist anodic corrosion during seawater splitting.
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Spinal cord injury (SCI) is a serious neurological insult that disrupts the ascending and descending neural pathways between the peripheral nerves and the brain, leading to not only functional deficits in the injured area and below the level of the lesion but also morphological, structural, and functional reorganization of the brain. These changes introduce new challenges and uncertainties into the treatment of SCI. Rehabilitation training, a clinical intervention designed to promote functional recovery after spinal cord and brain injuries, has been reported to promote activation and functional reorganization of the cerebral cortex through multiple physiological mechanisms. In this review, we evaluate the potential mechanisms of exercise that affect the brain structure and function, as well as the rehabilitation training process for the brain after SCI. Additionally, we compare and discuss the principles, effects, and future directions of several rehabilitation training methods that facilitate cerebral cortex activation and recovery after SCI. Understanding the regulatory role of rehabilitation training at the supraspinal center is of great significance for clinicians to develop SCI treatment strategies and optimize rehabilitation plans.
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The coronavirus disease 2019 (COVID-19) pandemic underlines a persistent threat of respiratory tract infectious diseases and warrants preparedness for a rapid response. At present, COVID-19 has had a serious social impact and imposed a heavy global burden on public health. The exact pathogenesis of COVID-19 has not been fully elucidated. Since the outbreak of COVID-19, a renewed attention has been brought to Toll-like receptors (TLRs). Available data and new findings have demonstrated that the interaction of human TLRs and SARS-CoV-2 is a vital mediator of COVID-19 immunopathogenesis. TLRs such as TLR2, 4, 7 and 8 are potentially important in viral combat and activation of immunity in patients with COVID-19. Therapeutics targeting TLRs are currently considered promising options against the pandemic. A number of TLR-targeting immunotherapeutics are now being investigated in preclinical studies and different phases of clinical trials. In addition, innovative vaccines based on TLRs under development could be a promising approach for building a new generation of vaccines to solve the current challenges. In this review, we summarize recent progress in the role of TLRs in COVID-19, focusing the new candidate drugs targeting TLRs, the current technology and potential paths forward for employing TLR agonists as vaccine adjuvants.
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COVID-19 , Vacinas , Humanos , SARS-CoV-2 , Surtos de Doenças , Receptores Toll-LikeRESUMO
BACKGROUND: Previous studies have shown that empathy has a positive impact on the professional identity of nursing students. And developing psychological resilience can improve the professional identity of nursing students. However, studies investigating the mechanism of the relationship between empathy and psychological resilience on professional identity remain few. PURPOSE: Among Chinese nursing students, we sought to determine whether psychological resilience mediates the association between empathy and professional identity. METHODS: A total of 495 undergraduate and postgraduate nursing students in a medical university nursing college in Hefei were investigated by demographic data questionnaire, nursing students' empathy scale, nursing students' professional identity questionnaire, and psychological resilience questionnaire. Structural equation modeling was used to analyze the mediating effect of psychological resilience between empathy and the professional identity of nursing students. RESULTS: The total score of professional identity of nursing students was 57.07 ± 10.38. Psychological resilience (r = 0.316, P < 0.01) and professional identity (r = 0.313, P < 0.01) both had positive correlations with empathy, respectively. Additionally, there was a strong correlation between psychological resilience and professional identity (r = 0.488, P < 0.01). Empathy had an indirect effect on professional identity through psychological resilience, with a direct effect of 0.256 and an indirect effect of 0.145, and the indirect effect accounted for 36.16 % of the total effect. CONCLUSION: Nursing educators should pay attention to the cultivation of empathy ability and psychological resilience to enhance nursing students' professional identity.
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Resiliência Psicológica , Estudantes de Enfermagem , Humanos , Estudantes de Enfermagem/psicologia , População do Leste Asiático , Estudos Transversais , Empatia , Inquéritos e QuestionáriosRESUMO
Thyroid cancer remains the most common endocrine malignancy worldwide, and its incidence has steadily increased over the past four years. Papillary Thyroid Cancer (PTC) is the most common differentiated thyroid cancer, accounting for 80-85% of all thyroid cancers. Mitochondrial proteins (MRPs) are an important part of the structural and functional integrity of the mitochondrial ribosomal complex. It has been reported that MRPL9 is highly expressed in liver cancer and promotes cell proliferation and migration, but it has not been reported in PTC. In the present study we found that MRPL9 was highly expressed in PTC tissues and cell lines, and lentivirus-mediated overexpression of MRPL9 promoted the proliferation and migration ability of PTC cells, whereas knockdown of MRPL9 had the opposite effect. The interaction between MRPL9 and GGCT (γ-glutamylcyclotransferase) was found by immunofluorescence and co-immunoprecipitation experiments (Co-IP). In addition, GGCT is highly expressed in PTC tissues and cell lines, and knockdown of GGCT/MRPL9 in vivo inhibited the growth of subcutaneous xenografts in nude mice and inhibited the formation of lung metastases. Mechanistically, we found that knockdown of GGCT/MRPL9 inhibited the MAPK/ERK signaling pathway. In conclusion, our study found that the interaction of GGCT and MRPL9 modulates the MAPK/ERK pathway, affecting the proliferation and migration of PTC cells. Therefore, GGCT/MRPL9 may serve as a potential biomarker for PTC monitoring and PTC treatment.
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Sistema de Sinalização das MAP Quinases , Neoplasias da Glândula Tireoide , gama-Glutamilciclotransferase , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Camundongos Nus , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , gama-Glutamilciclotransferase/genéticaRESUMO
BACKGROUND: Long non-coding RNAs (lncRNAs) are closely related to the occurrence and development of cancer. Abnormally expressed lncRNA can be used as a diagnostic marker for cancer. In this study, we aim to investigate the clinical significance of MIR99AHG expression in lung adenocarcinoma (LUAD), and its biological roles in LUAD progression. METHODS: The relative expression of MIR99AHG in LUAD tissues and cell lines was analyzed using public databases and RT-qPCR. The biological functions of MIR99AHG were investigated using a loss-of-function approach. The effect of MIR99AHG on lung fibrosis was assessed by scratch assay, invasion assay and lung fibrosis rat model. FISH, luciferase reporter assay and immunofluorescence were performed to elucidate the underlying molecular mechanisms. RESULTS: LncRNA MIR99AHG expression level was downregulated in LUAD tissues and cell lines. Low MIR99AHG levels were associated with poorer patient overall survival. Functional analysis showed that MIR99AHG is associated with the LUAD malignant phenotype in vitro and in vivo. Further mechanistic studies showed that, MIR99AHG functions as a competitive endogenous RNA (ceRNA) to antagonize miR-136-5p-mediated ubiquitin specific protease 4 (USP4) degradation, thereby unregulated the expression of angiotensin-converting enzyme 2 (ACE2), a downstream target gene of USP4, which in turn affected alveolar type II epithelial cell fibrosis and epithelial-mesenchymal transition (EMT). In summary, the MIR99AHG/miR-136-5p/USP4/ACE2 signalling axis regulates lung fibrosis and EMT, thus inhibiting LUAD progression. CONCLUSION: This study showed that downregulated MIR99AHG leads to the development of pulmonary fibrosis. Therefore, overexpression of MIR99AHG may provide a new approach to preventing LUAD progression.