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AIMS: Traumatic brain injury (TBI) stands as a significant concern in public health, frequently leading to enduring neurological deficits. Long non-coding RNA H19 (lncRNA H19) exerts a potential regulator role in the pathology of brain injury. This study investigates the effects of lncRNA H19 knockdown (H19-KD) on the pathophysiology of TBI and its potential neuroprotective mechanisms. METHODS: Controlled cortical impact was employed to establish a stable TBI mouse model. The expression levels of various genes in perilesional cortex and striatum tissue after TBI was detected by RT-qPCR. AAV9-shRNA-H19 was injected into the lateral ventricle of mice to knockdown the expression of lncRNA H19. Various behavioral tests were performed to evaluate sensorimotor and cognitive functions after TBI. Immunofluorescence and Nissl staining were performed to assess brain tissue damage and neuroinflammation. The Nrf2 and HO-1 expression was performed by Western blot. RESULTS: After TBI, the expression of lncRNA H19 was elevated in perilesional tissue and gradually reverted to baseline. Behavioral tests demonstrated that H19-KD significantly promoted the recovery of sensorimotor and cognitive functions after TBI. Besides, H19-KD reduced brain tissue loss, preserved neuronal integrity, and ameliorated white matter damage at the histological level. In addition, H19-KD restrained the pro-inflammatory and facilitated anti-inflammatory phenotypes of microglia/macrophages, attenuating the neuroinflammatory response after TBI. Furthermore, H19-KD promoted activation of the Nrf2/HO-1 axis after TBI, while suppression of Nrf2 partially abolished the neuroprotective effect. CONCLUSION: H19-KD exerts neuroprotective effects after TBI in mice, partially mediated by the activation of the Nrf2/HO-1 axis.
Sujet(s)
Lésions traumatiques de l'encéphale , Souris de lignée C57BL , Facteur-2 apparenté à NF-E2 , ARN long non codant , Récupération fonctionnelle , Animaux , ARN long non codant/génétique , ARN long non codant/métabolisme , Facteur-2 apparenté à NF-E2/métabolisme , Facteur-2 apparenté à NF-E2/génétique , Lésions traumatiques de l'encéphale/anatomopathologie , Lésions traumatiques de l'encéphale/métabolisme , Lésions traumatiques de l'encéphale/génétique , Souris , Récupération fonctionnelle/physiologie , Mâle , Techniques de knock-down de gènes/méthodes , Heme oxygenase-1/métabolisme , Protéines membranairesRÉSUMÉ
This paper proposes a complex boundary wave superposition method with a unique solution of full wavenumber based on the similarity between the acoustic wave superposition method (WSM) and the external excitation response of dynamic systems and combined with the idea that a damping system has a unique solution in dynamic theory. By placing the virtual equivalent source on the virtual boundary of complex space, the conventional WSM acquires damping properties comparable to those of the dynamical system. This approach successfully addresses the non-uniqueness of the solution at the eigenfrequency and is more efficient than the conventional combined layer potential method. The paper presents a comprehensive description of the proposed method, with a focus on theory, modeling, and parameter selection. The effectiveness of this method is evaluated by applying it to two types of acoustic problems, namely, radiation and scattering. The numerical results indicate that this method effectively addresses the non-unique problems encountered in conventional WSM. Furthermore, the proposed method is as accurate and efficient as the conventional WSM.
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Prolonging the lifetime of SAPO-34 catalysts and enhancing their olefin selectivity in methanol-to-olefin (MTO) reactions are critical yet challenging objectives. Here, a series of hierarchical SAPO-34 catalysts were synthesized using a straightforward recrystallization method. The incorporation of triethylamine into the recrystallization mother liquor facilitated the formation of mesopores, achieving a high solid yield of up to 90%. Notably, the addition of phosphoric acid and ammonium polyvinyl phosphate alcohol during the recrystallization process significantly enhanced the crystallinity and regularity of the hierarchical SAPO-34 crystals, consequently increasing the mesopore size. Due to the substantially improved mass transfer efficiency and moderated acidity, the SP34-0.14P-0.06R catalysts exhibited a prolonged lifetime of 344â min and 80.3% selectivity for ethylene and propylene at a weight hourly space velocity (WHSV) of 2â h-1. This performance markedly surpasses that of the parent SP34 catalyst, which demonstrated a lifetime of 136â min and a selectivity of 78.0%. Remarkably, the SP34-0.14P-0.06R maintained a lifetime of 166â min even at a high WHSV of 10â h-1, which is more than 5-fold greater than that of the original microporous SP34. This research offers valuable insights into the design and development of hierarchically porous zeolites with high yields, enhancing the efficiency of MTO reactions and other applications.
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The accumulation of self-renewed polarized microglia in the penumbra is a critical neuroinflammatory process after ischemic stroke, leading to secondary demyelination and neuronal loss. Although known to regulate tumor cell proliferation and neuroinflammation, HDAC3's role in microgliosis and microglial polarization remains unclear. We demonstrated that microglial HDAC3 knockout (HDAC3-miKO) ameliorated poststroke long-term functional and histological outcomes. RNA-seq analysis revealed mitosis as the primary process affected in HDAC3-deficent microglia following stroke. Notably, HDAC3-miKO specifically inhibited proliferation of proinflammatory microglia without affecting anti-inflammatory microglia, preventing microglial transition to a proinflammatory state. Moreover, ATAC-seq showed that HDAC3-miKO induced closing of accessible regions enriched with PU.1 motifs. Overexpressing microglial PU.1 via an AAV approach reversed HDAC3-miKO-induced proliferation inhibition and protective effects on ischemic stroke, indicating PU.1 as a downstream molecule that mediates HDAC3's effects on stroke. These findings uncovered that HDAC3/PU.1 axis, which mediated differential proliferation-related reprogramming in different microglia populations, drove poststroke inflammatory state transition, and contributed to pathophysiology of ischemic stroke.
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Accident vasculaire cérébral ischémique , Accident vasculaire cérébral , Microglie , Accident vasculaire cérébral/génétique , Prolifération cellulaire , GrainesRÉSUMÉ
BACKGROUND: Traumatic brain injury (TBI) is a significant worldwide public health concern that necessitates attention. Apoptosis signal-regulating kinase 1 (ASK1), a key player in various central nervous system (CNS) diseases, has garnered interest for its potential neuroprotective effects against ischemic stroke and epilepsy when deleted. Nonetheless, the specific impact of ASK1 on TBI and its underlying mechanisms remain elusive. Notably, mutation of ATP-binding sites, such as lysine residues, can lead to catalytic inactivation of ASK1. To address these knowledge gaps, we generated transgenic mice harboring a site-specific mutant ASK1 Map3k5-e (K716R), enabling us to assess its effects and elucidate potential underlying mechanisms following TBI. METHODS: We employed the CRIPR/Cas9 system to generate a transgenic mouse model carrying the ASK1-K716R mutation, aming to investigate the functional implications of this specific mutant. The controlled cortical impact method was utilized to induce TBI. Expression and distribution of ASK1 were detected through Western blotting and immunofluorescence staining, respectively. The ASK1 kinase activity after TBI was detected by a specific ASK1 kinase activity kit. Cerebral microvessels were isolated by gradient centrifugation using dextran. Immunofluorescence staining was performed to evaluate blood-brain barrier (BBB) damage. BBB ultrastructure was visualized using transmission electron microscopy, while the expression levels of endothelial tight junction proteins and ASK1 signaling pathway proteins was detected by Western blotting. To investigate TBI-induced neuroinflammation, we conducted immunofluorescence staining, quantitative real-time polymerase chain reaction (qRT-PCR) and flow cytometry analyses. Additionally, immunofluorescence staining and electrophysiological compound action potentials were conducted to evaluate gray and white matter injury. Finally, sensorimotor function and cognitive function were assessed by a battery of behavioral tests. RESULTS: The activity of ASK1-K716R was significantly decreased following TBI. Western blotting confirmed that ASK1-K716R effectively inhibited the phosphorylation of ASK1, JNKs, and p38 in response to TBI. Additionally, ASK1-K716R demonstrated a protective function in maintaining BBB integrity by suppressing ASK1/JNKs activity in endothelial cells, thereby reducing the degradation of tight junction proteins following TBI. Besides, ASK1-K716R effectively suppressed the infiltration of peripheral immune cells into the brain parenchyma, decreased the number of proinflammatory-like microglia/macrophages, increased the number of anti-inflammatory-like microglia/macrophages, and downregulated expression of several proinflammatory factors. Furthermore, ASK1-K716R attenuated white matter injury and improved the nerve conduction function of both myelinated and unmyelinated fibers after TBI. Finally, our findings demonstrated that ASK1-K716R exhibited favorable long-term functional and histological outcomes in the aftermath of TBI. CONCLUSION: ASK1-K716R preserves BBB integrity by inhibiting ASK1/JNKs pathway in endothelial cells, consequently reducing the degradation of tight junction proteins. Additionally, it alleviates early neuroinflammation by inhibiting the infiltration of peripheral immune cells into the brain parenchyma and modulating the polarization of microglia/macrophages. These beneficial effects of ASK1-K716R subsequently result in a reduction in white matter injury and promote the long-term recovery of neurological function following TBI.
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Lésions traumatiques de l'encéphale , Lésions encéphaliques , Substance blanche , Souris , Animaux , Barrière hémato-encéphalique/métabolisme , Maladies neuro-inflammatoires , Substance blanche/anatomopathologie , Cellules endothéliales/métabolisme , MAP Kinase Kinase Kinase 5/métabolisme , Lésions traumatiques de l'encéphale/anatomopathologie , Lésions encéphaliques/métabolisme , Protéines de la jonction serrée/métabolisme , Souris de lignée C57BLRÉSUMÉ
Autophagy is a promising target for promoting neural regeneration, which is essential for sensorimotor recovery following traumatic brain injury (TBI). Whether neuronal heat shock protein B2 (HSPB2), a small molecular heat shock protein, reduces injury and promotes recovery following TBI remains unclear. In this study, we demonstrated that HSPB2 was significantly increased in the neurons of a TBI mouse model, patients, and primary neuron cultures subjected to oxygen/glucose deprivation and reperfusion treatment. Upon creating a tamoxifen-induced neuron-specific HSPB2 overexpression transgenic mouse model, we found that elevated HSPB2 levels promoted long-term sensorimotor recovery and alleviated tissue loss after TBI. We also demonstrated that HSPB2 enhanced white matter structural and functional integrity, promoted central nervous system (CNS) plasticity, and accelerated long-term neural remodeling. Moreover, we found that autophagy occurred around injured brain tissues in patients, and the pro-regenerative effects of HSPB2 relied on its autophagy-promoting function. Mechanistically, HSPB2 may regulate autophagy possibly by forming the HSPB2/BCL2-associated athanogene 3/sequestosome-1 complex to facilitate the clearance of erroneously accumulated proteins in the axons. Treatment with the autophagy inhibitor chloroquine during the acute stage or delayed induction of HSPB2 remarkably impeded HSPB2's long-term reparative function, indicating the importance of acute-stage autophagy in long-term neuro-regeneration. Our findings highlight the beneficial role of HSPB2 in neuro-regeneration and functional recovery following acute CNS injury, thereby emphasizing the therapeutic potential of autophagy regulation for enhancing neuro-regeneration.
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Lésions traumatiques de l'encéphale , Petites protéines du choc thermique , Animaux , Souris , Protéines du choc thermique , Autophagie , Modèles animaux de maladie humaine , Souris transgéniques , Régénération nerveuseRÉSUMÉ
Although both are myeloid cells located surrounding cerebral vasculature, vessel-associated microglia (VAM) and perivascular macrophages (PVMs) can be distinguished by their distinct morphologies, signatures and microscopic location. As key component of neuro-glia-vascular unit (NGVU), they play prominent roles in neurovasculature development and pathological process of various central nervous system (CNS) diseases, including phagocytosis, angiogenesis, vessel damage/protection and blood flow regulation, therefore serving as potential targets for therapeutics of a broad array of CNS diseases. Herein, we will provide a comprehensive overview of heterogeneity of VAM/PVMs, highlight limitations of current understanding in this field, and discuss possible directions of future investigations.
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Maladies du système nerveux central , Microglie , Humains , Microglie/physiologie , Encéphale/anatomopathologie , Macrophages , Phagocytose , Maladies du système nerveux central/anatomopathologieRÉSUMÉ
Objective: Lymphagioma, which in most cases as benign tumors, occurs in head, neck, axilla, and mediastinum. Lymphangioma is exceedingly rare in the upper gastrointestinal tract including esophagus, stomach, and duodenum. However, the clinical characteristics, natural history, and recurrence rate after endoscopic resection remain unclear. This study aims to evaluate the characteristic findings and assess the efficacy of endoscopic techniques in the management of this disease. Methods: In this systematic retrospective analysis, we evaluated all 24 cases of upper gastrointestinal lymphangioma resected by endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) and diagnosed by histopathology at our hospital from January 2012 to May 2021. We analyzed the results of endoscopy, endoscopic ultrasonography (EUS), CT, histologic examination, and follow-up assessments. Results: 9 male and 15 female patients with esophageal lymphangioma were enrolled in this study, with a mean age of 54.17 ± 11.60 years (range 30-71 years). The lesions' size varied from 2.20 to 40.10 mm, with the median size of 7.83 mm. All patients were evaluated preoperatively, whose endoscopic appearance typically appears as dilated lymphatic channels beneath the surface epithelium of the protrude mucosal or sub-mucosal lesion. Endoscopic ultrasonography revealed the presence of a honeycomb-like or grid-like mass with a heterogeneous echo pattern, and a clear boundary between the lesion and the muscularis propria layer may be helpful for the primary diagnosis of this disease. 22 patients underwent EMR and 2 patient were treated with ESD. Histologic examination revealed that the lesions contained many dilated lymphatic vessels, which confirmed the initial diagnosis of lymphangioma in all patients. No major adverse events were found during the operation or a median follow-up of 43 months (range 13-92). Conclusions: Endoscopic ultrasonography has important clinical value for the primary diagnosis of lymphangioma in the upper gastrointestinal tract. This study also suggests that endoscopic resection should be considered as a more minimally invasive, safe, feasible, and effective therapeutic option comparing to laparoscopic surgery.
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Previous studies suggested that anti-inflammatory microglia/macrophages (Mi/MΦ) play a role in "normal phagocytosis," which promoted the rapid clearance of necrotic substances and apoptotic cells. More recently, a few studies have found that Mi/MΦ also play a role in "pathological phagocytosis" in the form of excessive or reduced phagocytosis, thereby worsening damage induced by CNS diseases. However, the underlying mechanisms and the Mi/MΦ subtypes related to this pathological phagocytosis are still unknown. Salt-inducible kinase 3 (SIK3), a member of the 5' adenosine monophosphate-activated protein kinase (AMPK) family, has been shown to regulate inflammation in several peripheral diseases. Whether SIK3 also regulates the inflammatory response in CNS diseases is currently unknown. Therefore, in this study, we created a transgenic tamoxifen-induced Mi/MΦ-specific SIK3 conditional knockout (SIK3-cKO) mouse to examine SIK3's role in phagocytotic function induced by transient focal cerebral ischemia (tFCI). By single-cell RNA-seq, we found the pro-inflammatory Mi/MΦ phenotype performed an excessive phagocytotic function, but the anti-inflammatory Mi/MΦ phenotype performed a normal phagocytotic function. We found that SIK3-cKO caused Mi/MΦ heterogenization from the transitional phenotype to the anti-inflammatory phenotype after tFCI. This phenotypic shift corresponded with enhanced phagocytosis of both apoptotic and live neurons. Interestingly, SIK3-cKO enhanced normal phagocytosis of myelin debris but attenuating excessive phagocytosis of non-damaged myelin sheath, thereby protecting white matter integrity after tFCI. CD16, a pro-inflammation marker, was decreased significantly by SIK3-cKO and correlated with "excessive phagocytosis." SIK3-cKO promoted long-term recovery of white matter function and neurological function as assessed with electrophysiological compound action potential (CAPs) and behavioral analysis. This study is the first to show a role of SIK3 in Mi/MΦ phagocytosis in CNS diseases, and reveals that promoting Mi/MΦ anti-inflammatory heterogenization inhibits "excessive phagocytosis" of live cells and facilitates "normal phagocytosis" of apoptotic cells. Therefore, inhibition of SIK3 in Mi/MΦ may be a potential therapeutic target in stroke and other CNS diseases with accompanying white matter destruction. In the acute stage of tFCI, Mi/MΦ polarized into different phenotypes. The pro-inflammatory Mi/MΦ phenotype performed an excessive phagocytotic function. In contrast, the anti-inflammatory Mi/MΦ phenotype performed a normal phagocytotic function. After tFCI, SIK3-cKO promoted anti-inflammatory phenotypic heterogenization of Mi/MΦ. SIK3-cKO promoted Mi/MΦ phagocytosis of apoptotic (normal phagocytosis) and living neuronal cell bodies (excessive phagocytosis) in gray matter. Interestingly, SIK3-cKO specifically increased normal phagocytosis of myelin debris concurrent with an attenuation of excessive phagocytosis of myelin sheath in white matter. These changes induced by SIK3-cKO were associated with protection of white matter integrity and long-term neurofunctional recovery after tFCI.
Sujet(s)
Encéphalopathie ischémique , Maladies du système nerveux central , Animaux , Encéphalopathie ischémique/métabolisme , Maladies du système nerveux central/anatomopathologie , Inflammation/anatomopathologie , Macrophages/métabolisme , Souris , Microglie/métabolisme , Phagocytose , Protein-Serine-Threonine Kinases/génétiqueRÉSUMÉ
Antibiotics abuse has caused various problems threatening human health and ecological environment. Monitoring antibiotics residual levels is of great significance, yet still challenging for quantitative point-of-need testing with high-sensitivity and visual capability. Here we developed a competitive lateral flow immunoassay (CLFIA) platform with flexible readout for enrofloxacin (ENR), a regularly added antibiotic. To overcome the limitation of low sensitivity of traditional colloidal gold-based CLFIA, the three-dimensionally assembled gold nanoparticles (AuNPs) within dendritic silica scaffold were fabricated as signal reporters. The assembly structure effectively retained the intrinsic absorption features of hydrophobic AuNPs and greatly enhanced the light extinction ability of a single label for signal amplification. The obtained CLFIA strips can not only achieve qualitative screening of ENR at a very low concentration by naked eye (cutoff value: 0.125 ng/mL), but also enable ultrasensitive quantification of ENR by an optical scanner (limit of detection: 0.00195 ng/mL) or a smartphone (limit of detection: 0.0078 ng/mL). Moreover, to elaborate the visual inspection degree of CLFIA against traditional yes/no interpretation, a novel multirange gradient CLFIA strip was prepared for visually semiquantitative identification of ENR with four concentration ranges. The novel CLFIA platform demonstrated sensitive, specific, and reliable determination of ENR with flexible signal readout and provides a potential and invigorating pathway to point-of-need immunoassay of antibiotics.
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Or , Nanoparticules métalliques , Enrofloxacine , Or colloïdal/composition chimique , Humains , Dosage immunologique , Limite de détection , Nanoparticules métalliques/composition chimiqueRÉSUMÉ
Colorectal cancer (CRC) is commonly associated with aberrant transcription regulation, but characteristics of the dysregulated transcription factors in CRC pathogenesis remain to be elucidated. In the present study, core-binding factor ß (CBFß) is found to be significantly upregulated in human CRC tissues and correlates with poor survival rate of CRC patients. Mechanistically, CBFß is found to promote CRC cell proliferation, migration, invasion, and inhibit cell apoptosis in a RUNX2-dependent way. Transcriptome studies reveal that CBFß and RUNX2 form a transcriptional complex that activates gene expression of OPN, FAM129A, and UPP1. Furthermore, CBFß significantly promotes CRC tumor growth and live metastasis in a mouse xenograft model and a mouse liver metastasis model. In addition, tumor-suppressive miR-143/145 are found to inhibit CBFß expression by specifically targeting its 3'-UTR region. Consistently, an inverse correlation between miR-143/miR-145 and CBFß expression levels is present in CRC patients. Taken together, this study uncovers a novel regulatory role of CBFß-RUNX2 complex in the transcriptional activation of OPN, FAM129A, and UPP1 during CRC development, and may provide important insights into CRC pathogenesis.
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Tumeurs colorectales/génétique , Sous-unité alpha 1 du facteur CBF/métabolisme , Sous-unités bêta du facteur CBF/métabolisme , Protéines et peptides de signalisation intracellulaire/métabolisme , Uridine phosphorylase/métabolisme , Animaux , Prolifération cellulaire , Tumeurs colorectales/mortalité , Évolution de la maladie , Humains , Souris , Analyse de survieRÉSUMÉ
Microglia are important phagocytes of the central nervous system (CNS). They play an important role in protecting the CNS by clearing necrotic tissue and apoptotic cells in many CNS diseases. However, recent studies have found that microglia can phagocytose parts of neurons excessively, such as the neuronal cell body, synapse, or myelin sheaths, before or after the onset of CNS diseases, leading to aggravated injury and impaired tissue repair. Meanwhile, reduced phagocytosis of synapses and myelin results in abnormal circuit connections and inhibition of remyelination, respectively. Previous studies focused primarily on the positive effects of microglia phagocytosis, whereas only a few studies have focused on the negative effects. In this review, we use the term "pathological microglial phagocytosis" to refer to excessive or reduced phagocytosis by microglia that leads to structural or functional abnormalities in target cells and brain tissue. The classification of pathological microglial phagocytosis, the composition, and activation of related signaling pathways, as well as the process of pathological phagocytosis in various kinds of CNS diseases, are described in this review. We hypothesize that pathological microglial phagocytosis leads to aggravation of tissue damage and negative functional outcome. For example, excessive microglial phagocytosis of synapses can be observed in Alzheimer's disease and schizophrenia, leading to significant synapse loss and memory impairment. In Parkinson's disease, ischemic stroke, and traumatic brain injury, excessive microglial phagocytosis of neuronal cell bodies causes impaired gray matter recovery and sensory dysfunction. We therefore believe that more studies should focus on the mechanism of pathological microglial phagocytosis and activation to uncover potential targets of therapeutic intervention.
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Maladies du système nerveux central/anatomopathologie , Microglie/anatomopathologie , Phagocytose , Animaux , Humains , Gaine de myéline , Neurones/anatomopathologie , Synapses/anatomopathologieRÉSUMÉ
Bile acids (BAs) are currently considered as causative agents for Cholangiocarcinoma (CCA). However, the profile of circulating BAs in CCA have not been well characterized. The aim of this study was to describe the alterations of BAs metabolism in patients with CCA compared to benign biliary diseases (BBD) and healthy controls (HC), and to discover the specific BAs as biomarkers for CCA diagnosis. The concentrations of 15 BAs in plasma were measured in a total of 329 subjects, including patients with BBD, CCA, gallbladder cancer (GC), hepatocellular carcinoma (HCC), and healthy subjects, using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Binary logistic regression analysis was used to build a diagnostic model for CCA. An imbalance in the ratio of conjugated to unconjugated BAs was observed in CCA patients compared to BBD and HC groups, with higher conjugated BAs and lower unconjugated BAs. A panel of 2 BA metabolites consisting of CDCA and TCDCA showed high diagnostic performance for CCA versus BBD and CCA versus HC, with higher AUC, sensitivity and specificity than carbohydrate antigen 19-9 (CA 199), clinically employed CCA biomarker. Importantly, HCC and GC samples were also included to confirm specificity of the BA biomarkers for CCA diagnosis. In summary, specific changes in plasma concentrations of BAs may serve as diagnostic biomarkers for distinguishing CCA from BBD and HC, with higher performance than CA199.
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Acides et sels biliaires/sang , Carcinome hépatocellulaire/sang , Cholangiocarcinome/sang , Tumeurs/sang , Adulte , Tumeurs des canaux biliaires/sang , Tumeurs des canaux biliaires/anatomopathologie , Carcinome hépatocellulaire/anatomopathologie , Cholangiocarcinome/anatomopathologie , Chromatographie en phase liquide , Diagnostic différentiel , Femelle , Humains , Tumeurs du foie , Mâle , Adulte d'âge moyen , Tumeurs/anatomopathologie , Spectrométrie de masse en tandemRÉSUMÉ
Demyelination occurs in response to brain injury and is observed in many neurodegenerative diseases. Myelin is synthesized from oligodendrocytes in the central nervous system, and oligodendrocyte death-induced demyelination is one of the mechanisms involved in white matter damage after stroke and neurodegeneration. Oligodendrocyte precursor cells (OPCs) exist in the brain of normal adults, and their differentiation into mature oligodendrocytes play a central role in remyelination. Although the differentiation and maturity of OPCs drive endogenous efforts for remyelination, the failure of axons to remyelinate is still the biggest obstacle to brain repair after injury or diseases. In recent years, studies have made attempts to promote remyelination after brain injury and disease, but its cellular or molecular mechanism is not yet fully understood. In this review, we discuss recent studies examining the demyelination process and potential therapeutic strategies for remyelination in aging and stroke. Based on our current understanding of the cellular and molecular mechanisms underlying remyelination, we hypothesize that myelin and oligodendrocytes are viable therapeutic targets to mitigate brain injury and to treat demyelinating-related neurodegeneration diseases.
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Vieillissement/métabolisme , Encéphale/métabolisme , Maladies démyélinisantes/métabolisme , Gaine de myéline/métabolisme , Accident vasculaire cérébral/métabolisme , Vieillissement/anatomopathologie , Animaux , Encéphale/anatomopathologie , Système nerveux central/métabolisme , Système nerveux central/anatomopathologie , Maladies démyélinisantes/anatomopathologie , Maladies démyélinisantes/thérapie , Humains , Gaine de myéline/anatomopathologie , Précurseurs des oligodendrocytes/métabolisme , Précurseurs des oligodendrocytes/anatomopathologie , Oligodendroglie/métabolisme , Oligodendroglie/anatomopathologie , Accident vasculaire cérébral/anatomopathologie , Accident vasculaire cérébral/thérapieRÉSUMÉ
To date, lanthanide-doped upconversion nanoparticles (UCNPs) have been widely reported as a promising CT contrast agent because they have high atomic numbers and big X-ray attenuation coefficient values. However, it is still a challenge to fabricate a simple multimodal imaging probe with improved image quality for early cancer diagnosis in clinical medicine. Herein, ultra-small, uniform and monodisperse ß-NaGdF4:Yb,Er,X% Lu (X = 0, 1, 2.5, 4, 6, 7.5) UCNPs were prepared through a solvothermal method with high-level modulation of both the phase and morphology. Meanwhile, a remarkably enhanced red upconversion luminescence (UCL) in the ß-NaGdF4:Yb,Er,X% Lu NPs was successfully realized via Lu3+ doping. It is found that as the content of Lu3+ increases from 0 to 7.5 mol%, the UCL intensity of the red emission first increases and then decreases, with the optimum doping content of Lu3+ ions of 2.5 mol%. The red UCL enhancement is ascribed to the change of the Yb-Er interionic distance controlling the Yb-Er energy transfer rate and the distortion of the local environment of Er3+ ions influencing the 4f-4f transition rates of Er3+ ions, which has been further confirmed by the experimental check of the crystallographic phase and by photoluminescence spectroscopy employing Eu3+ as the structural probe, respectively. More importantly, after being modified with the HS-PEG2000-NH2 ligand, the NH2-PEGylated-NaGdF4:Yb,Er,X% Lu NPs exhibited low cytotoxicity, high biocompatibility, and remarkably enhanced contrast performance in in vitro UCL and in vivo CT imaging. On the basis of our findings, the as-obtained functionalized UCNPs could be considered as a promising versatile dual-mode imaging probe for bioimaging, tumor diagnosis, and cancer therapy.
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Heart regeneration remains a critical question in current basic research and clinical practice. The adult mammalian heart exhibits a very limited regeneration capacity. In contrast, adult zebrafish and neonatal mice retain a remarkable ability of heart regeneration after damage. Understanding the mechanisms of heart regeneration would be very valuable to help design efficient treatment strategies against myocardial damage and heart failure. While inherent regeneration of the heart occurs after damage with varying efficiency among species, regeneration may also be induced exogenously. In this study, we briefly review the different approaches and current progress in improving heart regeneration.