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OBJECTIVE: Currently, little is known about the mechanism(s) regulating global and specific protein translation during metabolic dysfunction-associated steatohepatitis (MASH; previously known as non-alcoholic steatohepatitis, NASH). METHODS: Unbiased label-free quantitative proteome, puromycin-labelling and polysome profiling were used to understand protein translation activity in vitro and in vivo. RESULTS: We observed a global decrease in protein translation during lipotoxicity in human primary hepatocytes, mouse hepatic AML12 cells, and livers from a dietary mouse model of MASH. Interestingly, proteomic analysis showed that Rplp1, which regulates ribosome and translation pathways, was one of the most downregulated proteins. Moreover, decreased Esrra expression and binding to the Rplp1 promoter, diminished Rplp1 gene expression during lipotoxicity. This, in turn, reduced global protein translation and Esrra/Rplp1-dependent translation of lysosome (Lamp2, Ctsd) and autophagy (sqstm1, Map1lc3b) proteins. Of note, Esrra did not increase its binding to these gene promoters or their gene transcription, confirming its regulation of their translation during lipotoxicity. Notably, hepatic Esrra-Rplp1-dependent translation of lysosomal and autophagy proteins also was impaired in MASH patients and liver-specific Esrra knockout mice. Remarkably, alternate day fasting induced Esrra-Rplp1-dependent expression of lysosomal proteins, restored autophagy, and reduced lipotoxicity, inflammation, and fibrosis in hepatic cell culture and in vivo models of MASH. CONCLUSIONS: Esrra regulation of Rplp1-mediated translation of lysosome/autolysosome proteins was downregulated during MASH. Alternate day fasting activated this novel pathway and improved MASH, suggesting that Esrra and Rplp1 may serve as therapeutic targets for MASH. Our findings also provided the first example of a nuclear hormone receptor, Esrra, to not only regulate transcription but also protein translation, via induction of Rplp1.
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Ayuno , Lisosomas , Enfermedad del Hígado Graso no Alcohólico , Animales , Ratones , Humanos , Lisosomas/metabolismo , Ayuno/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/genética , Ratones Endogámicos C57BL , Proteínas Ribosómicas/metabolismo , Proteínas Ribosómicas/genética , Masculino , Hepatocitos/metabolismo , Biosíntesis de Proteínas , Autofagia , Hígado/metabolismo , Ratones NoqueadosRESUMEN
Atherosclerosis continues to be a leading cause of morbidity and mortality globally. The precise evaluation of the extent of an atherosclerotic plaque is essential for forecasting its likelihood of causing health concerns and tracking treatment outcomes. When compared to conventional methods used, nanoparticles offer clear benefits and excellent development opportunities for the detection and characterisation of susceptible atherosclerotic plaques. In this review, we analyse the recent advancements of nanoparticles as theranostics in the management of atherosclerosis, with an emphasis on applications in drug delivery. Furthermore, the main issues that must be resolved in order to advance clinical utility and future developments of NP research are discussed. It is anticipated that medical NPs will develop into complex and advanced next-generation nanobotics that can carry out a variety of functions in the bloodstream.
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Aterosclerosis , Sistemas de Liberación de Medicamentos , Nanopartículas , Humanos , Aterosclerosis/tratamiento farmacológico , Nanopartículas/química , Sistemas de Liberación de Medicamentos/métodos , Animales , Nanomedicina Teranóstica/métodos , Placa Aterosclerótica/tratamiento farmacológico , Portadores de Fármacos/químicaRESUMEN
Although a diversity of religions exists in South Korea, with Buddhism and Christianity (Protestantism and Catholicism) being the two main faiths, Korean beliefs are deeply rooted in Confucianism. Despite the notion that the Confucian norm of filial piety discourages body donation to medical science, there has been a mindset shift in favor of body donation, driven by a heightened awareness of the body bequest programs and the care and dignity accorded to the altruistic body donors, together with the institution of commemorative services to honor them. As spirituality and religion are known to be factors that influence body donation, how religious- and non-religious-based memorial services are held to honor the donors as exemplified by two Korean medical schools-from a public university with no religious affiliation and from a Protestant-based university-are described here. The key concept of expressing gratitude and respect for the donors and their family members has positively impacted body bequest programs in this multi-religious society. Commemorative services held to pay tribute to the altruistic body donors may play an important role in inspiring a humanistic spirit in students, regardless of religious or non-religious beliefs, as exemplified by the two Korean medical schools. The takeaway here is that the elevation of spirituality in memorial services effectively resonates with society, thereby demonstrating the impact of spiritual principles independent of religious influence.
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Peroxiredoxin 3 (PRDX3), a mitochondrial hydrogen peroxide scavenger, is known to be upregulated during tumorigenesis and cancer progression. In this study, we provide evidence for the first time that PRDX3 could regulate cellular signaling pathways associated with Matrix Metalloproteinase-1 (MMP-1) expression and activity in breast cancer progression. We show that shRNA-mediated gene silencing of PRDX3 inhibits cell migration and invasion in two triple-negative breast cancer cell lines. Reciprocal experiments show that PRDX3 overexpression promotes invasion and migration of the cancer cells, processes which are important in the metastatic cascade. Notably, this phenomenon may be attributed to the activation of MMP-1, which is observed to be upregulated by PRDX3 in the breast cancer cells. Moreover, immunohistochemical staining of breast cancer tissues revealed a positive correlation between PRDX3 and MMP-1 expression in both epithelial and stromal parts of the tissues. Further pathway reporter array and luciferase assay demonstrated that activation of ERK signaling is responsible for the transcriptional activation of MMP-1 in PRDX3-overexpressed cells. These findings suggest that PRDX3 could mediate cancer spread via ERK-mediated activation of MMP-1. Targeted inhibition of ERK signaling may be able to inhibit tumor metastasis in triple-negative breast cancer.
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BACKGROUND: Social behaviors such as altruism, where one self-sacrifices for collective benefits, critically influence an organism's survival and responses to the environment. Such behaviors are widely exemplified in nature but have been underexplored in cancer cells which are conventionally seen as selfish competitive players. This multidisciplinary study explores altruism and its mechanism in breast cancer cells and its contribution to chemoresistance. METHODS: MicroRNA profiling was performed on circulating tumor cells collected from the blood of treated breast cancer patients. Cancer cell lines ectopically expressing candidate miRNA were used in co-culture experiments and treated with docetaxel. Ecological parameters like relative survival and relative fitness were assessed using flow cytometry. Functional studies and characterization performed in vitro and in vivo include proliferation, iTRAQ-mass spectrometry, RNA sequencing, inhibition by small molecules and antibodies, siRNA knockdown, CRISPR/dCas9 inhibition and fluorescence imaging of promoter reporter-expressing cells. Mathematical modeling based on evolutionary game theory was performed to simulate spatial organization of cancer cells. RESULTS: Opposing cancer processes underlie altruism: an oncogenic process involving secretion of IGFBP2 and CCL28 by the altruists to induce survival benefits in neighboring cells under taxane exposure, and a self-sacrificial tumor suppressive process impeding proliferation of altruists via cell cycle arrest. Both processes are regulated concurrently in the altruists by miR-125b, via differential NF-κB signaling specifically through IKKß. Altruistic cells persist in the tumor despite their self-sacrifice, as they can regenerate epigenetically from non-altruists via a KLF2/PCAF-mediated mechanism. The altruists maintain a sparse spatial organization by inhibiting surrounding cells from adopting the altruistic fate via a lateral inhibition mechanism involving a GAB1-PI3K-AKT-miR-125b signaling circuit. CONCLUSIONS: Our data reveal molecular mechanisms underlying manifestation, persistence and spatial spread of cancer cell altruism. A minor population behave altruistically at a cost to itself producing a collective benefit for the tumor, suggesting tumors to be dynamic social systems governed by the same rules of cooperation in social organisms. Understanding cancer cell altruism may lead to more holistic models of tumor evolution and drug response, as well as therapeutic paradigms that account for social interactions. Cancer cells constitute tractable experimental models for fields beyond oncology, like evolutionary ecology and game theory.
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Neoplasias de la Mama , MicroARNs , Humanos , Femenino , Altruismo , Fosfatidilinositol 3-Quinasas , MicroARNs/genética , Neoplasias de la Mama/genéticaRESUMEN
Maternal diabetes has been associated with a greater risk of neurodevelopmental disorders in offspring. It has been established that hyperglycemia alters the expression of genes and microRNAs (miRNAs) regulating the fate of neural stem cells (NSCs) during brain development. In this study, the expression of methyl-CpG-binding protein-2 (Mecp2), a global chromatin organizer and a crucial regulator of synaptic proteins, was analyzed in NSCs obtained from the forebrain of embryos of diabetic mice. Mecp2 was significantly downregulated in NSCs derived from embryos of diabetic mice when compared to controls. miRNA target prediction revealed that the miR-26 family could regulate the expression of Mecp2, and further validation confirmed that Mecp2 is a target of miR-26b-5p. Knockdown of Mecp2 or overexpression of miR-26b-5p altered the expression of tau protein and other synaptic proteins, suggesting that miR-26b-5p alters neurite outgrowth and synaptogenesis via Mecp2. This study revealed that maternal diabetes upregulates the expression of miR-26b-5p in NSCs, resulting in downregulation of its target, Mecp2, which in turn perturbs neurite outgrowth and expression of synaptic proteins. Overall, hyperglycemia dysregulates synaptogenesis that may manifest as neurodevelopmental disorders in offspring from diabetic pregnancy.
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Diabetes Mellitus Experimental , Hiperglucemia , MicroARNs , Células-Madre Neurales , Embarazo , Femenino , Animales , Ratones , Diabetes Mellitus Experimental/genética , MicroARNs/genética , MicroARNs/metabolismo , Células-Madre Neurales/metabolismo , Neurogénesis/genética , Hiperglucemia/genética , Proteína 2 de Unión a Metil-CpG/genéticaRESUMEN
Rho GTPases regulate cell morphogenesis and motility under the tight control of guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). However, the underlying mechanism(s) that coordinate their spatiotemporal activities, whether separately or together, remain unclear. We show that a prometastatic RhoGAP, ARHGAP8/BPGAP1, binds to inactive Rac1 and localizes to lamellipodia. BPGAP1 recruits the RacGEF Vav1 under epidermal growth factor (EGF) stimulation and activates Rac1, leading to polarized cell motility, spreading, invadopodium formation, and cell extravasation and promotes cancer cell migration. Importantly, BPGAP1 down-regulates local RhoA activity, which influences Rac1 binding to BPGAP1 and its subsequent activation by Vav1. Our results highlight the importance of BPGAP1 in recruiting Vav1 and Rac1 to promote Rac1 activation for cell motility. BPGAP1 also serves to control the timing of Rac1 activation with RhoA inactivation via its RhoGAP activity. BPGAP1, therefore, acts as a dual-function scaffold that recruits Vav1 to activate Rac1 while inactivating RhoA to synchronize both Rho and Rac signaling in cell motility. As epidermal growth factor receptor (EGFR), Vav1, RhoA, Rac1, and BPGAP1 are all associated with cancer metastasis, BPGAP1 could provide a crucial checkpoint for the EGFR-BPGAP1-Vav1-Rac1-RhoA signaling axis for cancer intervention.
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Movimiento Celular , Proteínas Activadoras de GTPasa , Humanos , Secuencia de Aminoácidos , Receptores ErbB/metabolismo , Proteínas Activadoras de GTPasa/metabolismo , Proteína de Unión al GTP rac1/metabolismo , Proteínas de Unión al GTP rho/metabolismoRESUMEN
Breast carcinoma is the most prevalent cancer in women globally, with complex genetic and molecular mechanisms that underlie its development and progression. Several challenges such as metastasis and drug resistance limit the prognosis of breast cancer, and hence a constant search for better treatment regimes, including novel molecular therapeutic targets is necessary. Complement component 1, q subcomponent binding protein (C1QBP), a promising molecular target, has been implicated in breast carcinogenesis. In this study, the role of C1QBP in breast cancer progression, in particular cancer cell growth, was determined in triple negative MDA-MB-231 breast cancer cells. Depletion of C1QBP decreased cell proliferation, whereas the opposite effect was observed when C1QBP was overexpressed in MDA-MB-231 cells. Furthermore, gene expression profiling and pathway analysis in C1QBP depleted cells revealed that C1QBP regulates several signaling pathways crucial for cell growth and survival. Taken together, these findings provide a deeper comprehension of the role of C1QBP in triple negative breast cancer, and could possibly pave the way for future advancement of C1QBP-targeted breast cancer therapy.
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Neoplasias de la Mama , Neoplasias de la Mama Triple Negativas , Femenino , Humanos , Neoplasias de la Mama/metabolismo , Proteínas Mitocondriales/metabolismo , Transducción de Señal , Proteínas Portadoras/metabolismo , Proliferación Celular , Línea Celular Tumoral , Neoplasias de la Mama Triple Negativas/genéticaRESUMEN
Hepatobiliary magnetic resonance imaging (MRI) can inform the diagnosis of liver tumours in patients with liver cirrhosis and hepatitis. However, its clinical utility has been hampered by the lack of sensitive and specific contrast agents, partly because hepatocyte-specific nanoparticles, regardless of their surface ligands, are readily sequestered by Kupffer cells. Here we show, in rabbits, pigs and macaques, that the performance of hepatobiliary MRI can be enhanced by an ultrasmall nanoparticle composed of a manganese ferrite core (3 nm in diameter) and poly(ethylene glycol)-ethoxy-benzyl surface ligands binding to hepatocyte-specific transmembrane metal and anion transporters. The nanoparticle facilitated faster, more sensitive and higher-resolution hepatobiliary MRI than the clinically used contrast agent gadoxetate disodium, a substantial enhancement in the detection rate (92% versus 48%) of early-stage liver tumours in rabbits, and a more accurate assessment of biliary obstruction in macaques. The nanoparticle's performance and biocompatibility support the further translational development of liver-specific MRI contrast agents.
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Neoplasias Hepáticas , Nanopartículas , Animales , Conejos , Porcinos , Medios de Contraste/metabolismo , Ligandos , Hepatocitos/metabolismo , Imagen por Resonancia Magnética/métodosRESUMEN
BACKGROUND: Chronic mTORC1 activation in skeletal muscle is linked with age-associated loss of muscle mass and strength, known as sarcopenia. Genetic activation of mTORC1 by conditionally ablating mTORC1 upstream inhibitor TSC1 in skeletal muscle accelerates sarcopenia development in adult mice. Conversely, genetic suppression of mTORC1 downstream effectors of protein synthesis delays sarcopenia in natural aging mice. mTORC1 promotes protein synthesis by activating ribosomal protein S6 kinases (S6Ks) and inhibiting eIF4E-binding proteins (4EBPs). Whole-body knockout of S6K1 or muscle-specific over-expression of a 4EBP1 mutant transgene (4EBP1mt), which is resistant to mTORC1-mediated inhibition, ameliorates muscle loss with age and preserves muscle function by enhancing mitochondria activities, despite both transgenic mice showing retarded muscle growth at a young age. Why repression of mTORC1-mediated protein synthesis can mitigate progressive muscle atrophy and dysfunction with age remains unclear. METHODS: Mice with myofiber-specific knockout of TSC1 (TSC1mKO), in which mTORC1 is hyperactivated in fully differentiated myofibers, were used as a mouse model of sarcopenia. To elucidate the role of mTORC1-mediated protein synthesis in regulating muscle mass and physiology, we bred the 4EBP1mt transgene or S6k1 floxed mice into the TSC1mKO mouse background to generate 4EBP1mt-TSC1mKO or S6K1-TSC1mKO mice, respectively. Functional and molecular analyses were performed to assess their role in sarcopenia development. RESULTS: Here, we show that 4EBP1mt-TSC1mKO, but not S6K1-TSC1mKO, preserved muscle mass (36.7% increase compared with TSC1mKO, P < 0.001) and strength (36.8% increase compared with TSC1mKO, P < 0.01) at the level of control mice. Mechanistically, 4EBP1 activation suppressed aberrant protein synthesis (two-fold reduction compared with TSC1mKO, P < 0.05) and restored autophagy flux without relieving mTORC1-mediated inhibition of ULK1, an upstream activator of autophagosome initiation. We discovered a previously unidentified phenotype of lysosomal failure in TSC1mKO mouse muscle, in which the lysosomal defect was also conserved in the naturally aged mouse muscle, whereas 4EBP1 activation enhanced lysosomal protease activities to compensate for impaired autophagy induced by mTORC1 hyperactivity. Consequently, 4EBP1 activation relieved oxidative stress to prevent toxic aggregate accumulation (0.5-fold reduction compared with TSC1mKO, P < 0.05) in muscle and restored mitochondrial homeostasis and function. CONCLUSIONS: We identify 4EBP1 as a communication hub coordinating protein synthesis and degradation to protect proteostasis, revealing therapeutic potential for activating lysosomal degradation to mitigate sarcopenia.
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Diana Mecanicista del Complejo 1 de la Rapamicina , Sarcopenia , Animales , Ratones , Modelos Animales de Enfermedad , Diana Mecanicista del Complejo 1 de la Rapamicina/genética , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Ratones Noqueados , Ratones Transgénicos , Sarcopenia/genética , Sarcopenia/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
Introduction: Microinvasion (Mi) is often thought to be an interim stage between ductal carcinoma in situ (DCIS) and invasive ductal carcinoma. This study aimed to investigate the potential influence of Mi on survival and assess its correlations with clinicopathological parameters, prognosis and molecular markers. Methods: The number of Mi foci in a cohort of 66 DCIS-Mi cases was assessed from haematoxylin and eosin-stained sections. Disease-free survival, clinicopathological parameters and biomarker expression were correlated with the number of Mi foci. Results: Higher numbers of Mi foci were found in larger tumours (P = 0.031). Conclusion: Greater extent of DCIS is associated with multifocal Mi.
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Neoplasias de la Mama , Carcinoma Ductal de Mama , Carcinoma Intraductal no Infiltrante , Humanos , Femenino , Pronóstico , Supervivencia sin Enfermedad , Supervivencia sin Progresión , Carcinoma Ductal de Mama/patología , Invasividad NeoplásicaRESUMEN
PURPOSE: The aims of this study were (1) to develop a three-dimensional (3D) printed simulator that facilitates the simulation of surgical skills for portal placement, intra-articular identification of anatomical structures and arthroscope navigation for hip arthroscopy and (2) to concurrently examine the feasibility of using this simulator as an assessment tool to evaluate trainees' surgical competencies. METHODS: A simulator was developed using a combination of medical imaging, computer-aided design, and 3D printing. A cross-sectional study was conducted with 29 participants divided into 3 subgroups (novice, intermediate and experienced). All participants performed related skills on the simulator, and their performance was evaluated using different assessment parameters. The participants' qualitative feedback regarding the simulator was also collected. The data collated from each group of participants were subsequently compared. RESULTS: Significant differences were observed between the three subgroups of participants with regard to the total checklist score (F2,26 = 11.3), total Arthroscopic Surgical Skill Evaluation score (F2,26 = 92.1), overall final global rating scale score (F2,26 = 49), number of times the participants used fluoroscopy (F2,26 = 7.4), and task completion times (F2,26 = 23.5). The participants' performance in the simulated operation was correlated with their prior clinical experience. There was mainly positive feedback with regard to the fidelity and utility of the simulator in relation to the surgeons' prior clinical experience. CONCLUSIONS: This study demonstrated that a reliable hip arthroscopic simulator can be developed for use by orthopedic surgeons to evaluate their hip arthroscopic skills before performing actual surgical operations. LEVEL OF EVIDENCE: Level III.
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Artroscopía , Cirujanos , Humanos , Estudios Transversales , Competencia Clínica , Simulación por ComputadorRESUMEN
Objective: This study aimed to investigate the feasibility of using eye tracking data to identify orthopedic trainees' technical proficiency in hip arthroscopic procedures during simulation-based training. Design: A cross sectional study. Setting: A simulation-based training session for hip arthroscopy was conducted. Eye tracking devices were used to record participants' eye movements while performing simulated operations. The NASA Task Load Index survey was then used to measure subjective opinions on the perceived workload of the training. Statistical analyses were performed to determine the significance of the eye metrics and survey data. Participants: A total of 12 arthroscopic trainees, including resident doctors, junior specialist surgeons, and consultant surgeons from the Department of Orthopedics in five hospitals, participated in this study. They were divided into three subgroups based on their prior clinical experience. Results: Significant differences, including those for dwell time, number of fixations, number of saccades, saccade duration, peak velocity of the saccade, and pupil entropy, were observed among the three subgroups. Additionally, there were clear trends in the perceived workload of the simulation-based training based on feedback from the participants. Conclusion: Based on this preliminary study, a correlation was identified between the eye tracking metrics and participants' experience levels. Hence, it is feasible to apply eye tracking data as a supplementary objective assessment tool to benchmark the technical proficiency of surgical trainees in hip arthroscopy, and enhance simulation-based training.
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Labeling stem cells with magnetic nanoparticles is a promising technique for in vivo tracking and magnetic targeting of transplanted stem cells, which is critical for improving the therapeutic efficacy of cell therapy. However, conventional endocytic labeling with relatively poor labeling efficiency and a short labeling lifetime has hindered the implementation of these innovative enhancements in stem-cell-mediated regenerative medicine. Herein, we describe an advanced magnetothermal approach to label mesenchymal stem cells (MSCs) efficiently by local induction of heat-enhanced membrane permeability for magnetic resonance imaging (MRI) tracking and targeted therapy of stroke, where biocompatible γ-phase, ferrimagnetic vortex-domain iron oxide nanorings (γ-FVIOs) with superior magnetoresponsive properties were used as a tracer. This approach facilitates a safe and efficient labeling of γ-FVIOs as high as 150 pg of Fe per cell without affecting the MSCs proliferation and differentiation, which is 3.44-fold higher than that by endocytosis labeling. Such a high labeling efficiency not only enables the ultrasensitive magnetic resonance imaging (MRI) detection of sub-10 cells and long-term tracking of transplanted MSCs over 10 weeks but also endows transplanted MSCs with a magnetic manipulation ability in vivo. A proof-of-concept study using a rat stroke model showed that the labeled MSCs facilitated MRI tracking and magnetic targeting for efficient replacement therapy with a significantly reduced dosage of 5 × 104 transplanted cells. The findings in this study have demonstrated the great potential of the magnetothermal approach as an efficient labeling technique for future clinical usage.
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Nanopartículas de Magnetita , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas , Accidente Cerebrovascular , Ratas , Animales , Rastreo Celular/métodos , Imagen por Resonancia Magnética/métodos , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/terapia , Accidente Cerebrovascular/metabolismo , Trasplante de Células Madre Mesenquimatosas/métodosRESUMEN
PURPOSE: The purpose of this study is to investigate the importance of general and specific surgical skills for hip arthroscopy from the perspective of surgeons in China. Concurrently, we intend to identify the preferred type of simulation that would facilitate competency of surgical trainees in performing arthroscopy and reinforce their preparation for carrying out the actual surgical procedure. METHODS: An online survey comprising 42 questions was developed by experts in hip arthroscopy and sent to 3 online communities whose members are arthroscopic surgeons in China. The responses collected were based on a 5-point Likert scale, with an open-ended comment section. Data were analyzed using one-way AVOVA and post hoc Tukey's test. RESULTS: A total of 159 valid responses from 66 junior specialist surgeons, 68 consultant surgeons, and 25 senior consultant surgeons (from 130 institutions in 27 out of 34 provincial administrative districts in China) were collected. Cognitive ability was identified as the overall most important attribute for hip arthroscopic trainees to possess, while skills relevant to the treatment of femoroacetabular impingement (FAI) were considered as the most important specific skills by the surgeons surveyed. In addition, simulation using cadaveric specimens was considered the most favorable method for surgeons to practice their surgical skills. CONCLUSION: In designing a training program for hip arthroscopy, it is essential to incorporate features that evaluate cognitive skills. It would be helpful for trainees to specifically practice skills that are often used in the treatment of some very common diseases of the hip joint, such as FAI. Using high-fidelity physical models for simulation to train skills of hip arthroscopy could be an ideal alternative and effective way to overcome problems arising from the lack of accessibility to cadaveric specimens.
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Pinzamiento Femoroacetabular , Entrenamiento Simulado , Cirujanos , Artroscopía/métodos , Cadáver , Pinzamiento Femoroacetabular/cirugía , Articulación de la Cadera/cirugía , HumanosRESUMEN
SIRT1 (silent mating type information regulation 2 homolog 1), a class III histone deacetylase, is known to participate in multiple steps of the DNA damage response (DDR) by deacetylating several key DDR proteins. At present, the mechanisms regulating SIRT1 protein stability upon DNA damage have yet to be fully elucidated. In this study, we reveal that, under severe DNA damage, SIRT1 undergoes two forms of post-translational modifications (PTMs): (i) increased polyubiquitination and proteasomal degradation mediated by TRIM28 (tripartite motif-containing protein 28), a RING-domain E3 ligase; and (ii) cleavage at C-terminal mediated by caspases. Importantly, there is reciprocal effects between these forms of PTMs: while suppression of proteasome reduces caspases-mediated cleavage, the cleaved SIRT1 has enhanced interaction with TRIM28, thus facilitating the ubiquitination and proteasomal degradation of SIRT1. Functionally, SIRT1 works as an anti-apoptotic protein in DDR, and the above-mentioned PTMs of SIRT1 subsequently enhances cell death induced by DNA damage agents. Thus, our study has uncovered a pivotal role of SIRT1 post-translational regulation in determining cell fate in DDR.
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Procesamiento Proteico-Postraduccional , Sirtuina 1 , Caspasas/genética , Daño del ADN/genética , Procesamiento Proteico-Postraduccional/genética , Sirtuina 1/genética , Sirtuina 1/metabolismo , Factores de Transcripción/metabolismo , UbiquitinaciónRESUMEN
Breast cancer remains the most common malignancy among women worldwide. Although the implementation of mammography has dramatically increased the early detection rate, conventional treatments like chemotherapy, radiation therapy, and surgery, have significantly improved the prognosis for breast cancer patients. However, about a third of treated breast cancer patients are known to suffer from disease recurrences and progression to metastasis. Immunotherapy has recently gained traction due to its ability to establish long-term immune surveillance, and response for the prevention of disease recurrence and extension of patient survival. Current research findings have revealed that gold nanoparticles can enhance the safety and efficacy of cancer immunotherapy, through their unique intrinsic properties of good biocompatibility, durability, convenient surface modification, as well as enhanced permeability and retention effect. Gold nanoparticles are also able to induce innate immune responses through the process of immunogenic cell death, which can lead to the establishment of lasting adaptive immunity. As such gold nanoparticles are considered as good candidates for next generation immunotherapeutic strategies. This mini review gives an overview of gold nanoparticles and their potential applications in breast cancer immunotherapeutic strategies.
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Neoplasias de la Mama , Nanopartículas del Metal , Neoplasias de la Mama/terapia , Femenino , Oro , Humanos , Inmunoterapia , Masculino , Nanopartículas del Metal/uso terapéutico , Recurrencia Local de NeoplasiaRESUMEN
Background: Nonalcoholic steatohepatitis (NASH) is characterized by hepatic steatosis, lobular inflammation, and fibrosis. Thyroid hormone (TH) reduces steatosis; however, the therapeutic effect of TH on NASH-associated inflammation and fibrosis is not known. This study examined the therapeutic effect of TH on hepatic inflammation and fibrosis during NASH and investigated THs molecular actions on autophagy and mitochondrial biogenesis. Methods: HepG2-TRß cells were treated with bovine serum albumin-conjugated palmitic acid (PA) to mimic lipotoxic conditions in vitro. Mice with NASH were established by feeding C57BL/6J mice Western diet with 15% fructose in drinking water for 16 weeks. These mice were administered triiodothyronine (T3)/thyroxine (T4) supplemented in drinking water for the next eight weeks. Results: In cultured HepG2-TRß cells, TH treatment increased mitochondrial respiration and fatty acid oxidation under basal and PA-treated conditions, as well as decreased lipopolysaccharides and PA-stimulated inflammatory and fibrotic responses. In a dietary mouse model of NASH, TH administration decreased hepatic triglyceride content (3.19 ± 0.68 vs. 8.04 ± 0.42 mM/g liver) and hydroxyproline (1.44 ± 0.07 vs. 2.58 ± 0.30 mg/g liver) when compared with mice with untreated NASH. Metabolomics profiling of lipid metabolites showed that mice with NASH had increased triacylglycerol, diacylglycerol, monoacylglycerol, and hepatic cholesterol esters species, and these lipid species were decreased by TH treatment. Mice with NASH also showed decreased autophagic degradation as evidenced by decreased transcription Factor EB and lysosomal protease expression, and accumulation of LC3B-II and p62. TH treatment restored the level of lysosomal proteins and resolved the accumulation of LC3B-II and p62. Impaired mitochondrial biogenesis was also restored by TH. The simultaneous restoration of autophagy and mitochondrial biogenesis by TH increased ß-oxidation of fatty acids. Additionally, the elevated oxidative stress and inflammasome activation in NASH liver were also decreased by TH. Conclusions: In a mouse model of NASH, TH restored autophagy and mitochondrial biogenesis to increase ß-oxidation of fatty acids and to reduce lipotoxicity, oxidative stress, hepatic inflammation, and fibrosis. Activating thyroid hormone receptor in the liver may represent an effective strategy for NASH treatment.
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Agua Potable , Enfermedad del Hígado Graso no Alcohólico , Animales , Modelos Animales de Enfermedad , Agua Potable/metabolismo , Ácidos Grasos/metabolismo , Fibrosis , Humanos , Inflamación/metabolismo , Hígado/metabolismo , Ratones , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Hormonas Tiroideas/metabolismo , Triglicéridos/metabolismoRESUMEN
Renal cell carcinoma (RCC) makes up the majority of kidney cancers, with a poor prognosis for metastatic RCC (mRCC). Challenges faced in the management of mRCC, include a lack of reliable prognostic markers and biomarkers for precise monitoring of disease treatment, together with the potential risk of toxicity associated with more recent therapeutic options. Glycosaminoglycans (GAGs) are a class of carbohydrates that can be categorized into four main subclasses, viz., chondroitin sulfate, hyaluronic acid, heparan sulfate and keratan sulfate. GAGs are known to be closely associated with cancer progression and modulation of metastasis by modification of the tumor microenvironment. Alterations of expression, composition and spatiotemporal distribution of GAGs in the extracellular matrix (ECM), dysregulate ECM functions and drive cancer invasion. In this review, we focus on the clinical utility of GAGs as biomarkers for mRCC (which is important for risk stratification and strategizing effective treatment protocols), as well as potential therapeutic targets that could benefit patients afflicted with advanced RCC. Besides GAG-targeted therapies that holds promise in mRCC, other potential strategies include utilizing GAGs as drug carriers and their mimetics to counter cancer progression, and enhance immunotherapy through binding and transducing signals for immune mediators.
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PURPOSE: Invasion of carcinoma cells into surrounding tissue affects breast cancer staging, influences choice of treatment, and impacts on patient outcome. KIF21A is a member of the kinesin superfamily that has been well-studied in congenital extraocular muscle fibrosis. However, its biological relevance in breast cancer is unknown. This study investigated the functional roles of KIF21A in this malignancy and examined its expression pattern in breast cancer tissue. METHODS: The function of KIF21A in breast carcinoma was studied in vitro by silencing its expression in breast cancer cells and examining the changes in cellular activities. Immunohistochemical staining of breast cancer tissue microarrays was performed to determine the expression patterns of KIF21A. RESULTS: Knocking down the expression of KIF21A using siRNA in MDA-MB-231 and MCF7 human breast cancer cells resulted in significant decreases in tumor cell migration and invasiveness. This was associated with reduced Patched 1 expression and F-actin microfilaments. Additionally, the number of focal adhesion kinase- and paxillin-associated focal adhesions was increased. Immunohistochemical staining of breast cancer tissue microarrays showed that KIF21A was expressed in both the cytoplasmic and nuclear compartments of carcinoma cells. Predominance of cytoplasmic KIF21A was significantly associated with larger tumors and high grade cancer, and prognostic of cause-specific overall patient survival and breast cancer recurrence. CONCLUSION: The data demonstrates that KIF21A is an important regulator of breast cancer aggressiveness and may be useful in refining prognostication of this malignant disease.