Inhibition of Anaplastic Lymphoma Kinase Protects From Ischemic Stroke.

BACKGROUND: Ischemic stroke is often accompanied by oxidative stress and inflammatory response, both of which work synergistically to exacerbate the disruption of the blood-brain barrier and ischemic brain injury. ALK (anaplastic lymphoma kinase), a cancer-associated receptor tyrosine kinase, was found to play a role in oxidative stress and inflammation. In this study, we investigated the role of ALK inhibition in a murine model of ischemic stroke. METHODS: Focal cerebral ischemia was induced by temporary occlusion of the right middle cerebral artery in mice with a filament. The ALK inhibitor alectinib was administered following the stroke. ALOX15 (arachidonic acid 15-lipoxygenase) was overexpressed by adenovirus injection. The immunohistochemistry, Western blot, oxidative stress, inflammation, blood-brain barrier leakage, infarct volume, and functional outcomes were determined. RESULTS: We found that the expression of ALK was markedly increased in the neurovascular unit after cerebral ischemia. Treatment with the ALK inhibitor alectinib reduced the accumulation of reactive oxygen species, lipid peroxidation, and oxidative DNA, increased the vascular levels of antioxidant enzymes, inactivated the vascular NLRP3 (nucleotide-binding oligomerization domain-like receptor protein 3) inflammasome pathway, and reduced vascular inflammation (ICAM-1 [intercellular adhesion molecule-1] and MCP-1 [monocyte chemoattractant protein-1]) after ischemia. Moreover, alectinib reduced the loss of cerebrovascular integrity and blood-brain barrier damage, consequently decreasing brain infarction and neurological deficits. Furthermore, alectinib reduced stroke-evoked ALOX15 expression, whereas virus-mediated overexpression of ALOX15 abolished alectinib-dependent inhibition of oxidative stress and vascular inflammation, blood-brain barrier protection, and neuroprotection, suggesting the protective effects of alectinib for stroke may involve ALOX15. CONCLUSIONS: Our findings demonstrated that alectinib protects from stroke by regulating ischemic signaling cascades and suggest that ALK may be a novel therapeutic target for ischemic stroke.

The LPS-inactivating enzyme acyloxyacyl hydrolase protects the brain from experimental stroke.

Blood-brain-barrier (BBB) disruption is a pathological hallmark of ischemic stroke, and inflammation occurring at the BBB contributes to the pathogenesis of ischemic brain injury. Lipopolysaccharide (LPS), a cell wall component of Gram-negative bacteria, is elevated in patients with acute stroke. The activity of LPS is controlled by acyloxyacyl hydrolase (AOAH), a host enzyme that deacylates LPS to inactivated forms. However, whether AOAH influences the pathogenesis of ischemic stroke remain elusive. We performed in vivo experiments to explore the role and mechanism of AOAH on neutrophil extravasation, BBB disruption, and brain infarction. We found that AOAH was upregulated in neutrophils in peri-infarct areas from mice with transient focal cerebral ischemia. AOAH deficiency increased neutrophil extravasation into the brain parenchyma and proinflammatory cytokine production, broke down the BBB and worsened stroke outcomes in mice. These effects require Toll-like receptor 4 (TLR4) because absence of TLR4 or pharmacologic inhibition of TLR4 signaling prevented the exacerbated inflammation and BBB damage in Aoah-/- mice after ischemic stroke. Importantly, neutrophil depletion or inhibition of neutrophil trafficking by blocking LFA-1 integrin dramatically reduced stroke-induced BBB breakdown in Aoah-/- mice. Furthermore, virus-mediated overexpression of AOAH induced a substantial decrease in neutrophil recruitment that was accompanied by reducing BBB damage and stroke volumes. Our findings show the importance of AOAH in regulating neutrophil-dependent BBB breakdown and cerebral infarction. Consequently, strategies that modulate AOAH may be a new therapeutic approach for treatment of ischemic stroke.

Interleukin 28A aggravates Con A-induced acute liver injury by promoting the recruitment of M1 macrophages.

Immune-mediated acute hepatic injury is characterized by the destruction of a large number of hepatocytes and severe liver function damage. Interleukin-28A (IL-28A), a member of the IL-10 family, is notable for its antiviral properties. However, despite advances in our understanding of IL-28A, its role in immune-mediated acute injury remains unclear. The present study investigated the role of IL-28A in concanavalin A (Con A)-induced acute immune liver injury. After Con A injection in mice, IL-28A level significantly increased. IL-28A deficiency was found to protect mice from acute liver injury, prolong survival time, and reduce serum aspartate aminotransferase and alanine aminotransferase levels. In contrast, recombinant IL-28A aggravated liver injury in mice. The proportion of activated M1 macrophages was significantly lower in the IL-28A-deficiency group than in the wild-type mouse group. In adoptive transfer experiments, M1 macrophages from WT could exacerbate mice acute liver injury symptoms in the IL-28A deficiency group. Furthermore, the expression of proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), IL-12, IL-6, and IL-1ß, by M1 macrophages decreased significantly in the IL-28A-deficiency group. Western blotting demonstrated that IL-28A deficiency could limit M1 macrophage polarization by modulating the nuclear factor (NF)-κB, mitogen-activated protein kinase (MAPK), and interferon regulatory factor (IRF) signaling pathways. In summary, IL-28A deletion plays an important protective role in the Con A-induced acute liver injury model and IL-28A deficiency inhibits the activation of M1 macrophages by inhibiting the NF-κB, MAPK, and IRF signaling pathways. These results provide a potential new target for the treatment of immune-related hepatic injury.

Cornuside improves murine autoimmune hepatitis through inhibition of inflammatory responses.

BACKGROUND: Autoimmune hepatitis (AIH) poses an important public health concern worldwide, with few therapeutic options available. Cornuside, a primary cornel iridoid glycoside present in Cornus officinalis Sieb. et Zucc., is a well-known traditional Chinese medicine that possesses anti-inflammatory, antioxidant and anti-apoptotic properties. However, the effects of cornuside on autoimmune diseases including AIH is still not defined, neither is clear on the mechanisms of cornuside in the suppression of inflammatory responses. PURPOSE: The study was aimed to investigate the therapeutic effects of cornuside on AIH using murine models. STUDY DESIGN: A murine model of AIH induced by concanavalin A (Con A) was used to examine the pharmacological activity of cornuside in suppressing the inflammatory responses in vivo. METHODS: C57BL/6J mice were intravenously with different doses of cornuside and challenged with 18 mg/kg Con A 3 h later. Network pharmacological analysis was performed to identify the potential target genes and signaling pathways by cornuside in AIH. Next serum and liver tissues were collected 12 h after Con A injection to analyze the levels of markers for hepatic injury, apoptosis, oxidative stress, immune responses, and inflammation. RESULTS: Network pharmacological analysis revealed that cornuside may modulate oxidative stress and apoptosis in AIH. Compared with the Con A group, cornuside pretreatment significantly reduced the serum levels of alanine aminotransferase and aspartate aminotransferase, improving histopathological damage and apoptosis in the livers. In addition, cornuside decreased the levels of malondialdehyde, myeloperoxidase, but increased superoxide dismutase levels, suggesting the relieving of oxidative stress. Furthermore, cornuside suppressed the activation of T and natural killer T cells, whereas the proportion of myeloid-derived suppressor cells was significantly increased. The production of proinflammatory cytokines, including interleukin (IL)-6, IL-12, IL-1ß, and tumor necrosis factor-alpha (TNF-α), was also clearly decreased. Finally, western blot analysis displayed that cornuside inhibited the phosphorylation of extracellular receptor kinase (ERK) and c-Jun N-terminal kinase (JNK). CONCLUSIONS: We demonstrated that cornuside has protective effects for Con A-induced immune-mediated hepatitis by suppressing the oxidative stress, apoptosis, and the inflammatory responses through the ERK and JNK signaling pathways, as well as by modulating the activation and recruitment of immune cells.

CholecTriplet2021: A benchmark challenge for surgical action triplet recognition.

Context-aware decision support in the operating room can foster surgical safety and efficiency by leveraging real-time feedback from surgical workflow analysis. Most existing works recognize surgical activities at a coarse-grained level, such as phases, steps or events, leaving out fine-grained interaction details about the surgical activity; yet those are needed for more helpful AI assistance in the operating room. Recognizing surgical actions as triplets of combination delivers more comprehensive details about the activities taking place in surgical videos. This paper presents CholecTriplet2021: an endoscopic vision challenge organized at MICCAI 2021 for the recognition of surgical action triplets in laparoscopic videos. The challenge granted private access to the large-scale CholecT50 dataset, which is annotated with action triplet information. In this paper, we present the challenge setup and the assessment of the state-of-the-art deep learning methods proposed by the participants during the challenge. A total of 4 baseline methods from the challenge organizers and 19 new deep learning algorithms from the competing teams are presented to recognize surgical action triplets directly from surgical videos, achieving mean average precision (mAP) ranging from 4.2% to 38.1%. This study also analyzes the significance of the results obtained by the presented approaches, performs a thorough methodological comparison between them, in-depth result analysis, and proposes a novel ensemble method for enhanced recognition. Our analysis shows that surgical workflow analysis is not yet solved, and also highlights interesting directions for future research on fine-grained surgical activity recognition which is of utmost importance for the development of AI in surgery.

Differences in clinical characteristics and chest CT findings between severe and critical H1N1 pneumonia.

INTRODUCTION: Critical H1N1 pneumonia patients usually have one of the symptoms such as respiratory failure, septic shock, multiple organ dysfunction, or other need for intensive care management, which are associated with high risk of mortality. It is essential to differentiate the severity of H1N1 pneumonia and take corresponding target treatments. OBJECTIVES: We aim to investigate the differences in clinical characteristics and chest computed tomography (CT) findings between severe and critical patients with H1N1 pneumonia. METHODS: A total of 27 patients diagnosed with H1N1 pneumonia from October 2018 to March 2019 were retrospectively analyzed, and the differences in clinical manifestations, laboratory tests, and chest CT findings between the severe group (15 patients) and the critical group (12 patients) were compared. RESULTS: Frequency of dyspnea at rest was higher in critical group than that in severe group (P = 0.019). The neutrophil percentage was higher (P = 0.014) and the lymphocyte percentage was lower (P = 0.025) in critical compared with severe group. Bilateral lung involvement was the predominant pattern in both severe and critical patients, whereas the number of involved lobes in critical patients was more than that in severe patients (P = 0.024). Peripheral distribution was the predominant pattern in severe patients (40%), whereas more diffuse involvement of the lungs was observed in critical patients (83.30%). Ground-glass opacities and consolidation were the main CT findings in both groups, and prevalence of consolidation was higher in critical relative to severe group (83.30%). CONCLUSION: Compared with severe patients, those with critical H1N1 pneumonia were more likely to present with dyspnea at rest and decreased lymphocyte percentage. Chest CT showed that diffuse bilateral involvement and higher prevalence of consolidation are associated with critical outcomes.

Functional Blood-Brain Barrier Model with Tight Connected Minitissue by Liquid Substrates Culture.

The functional blood-brain barrier (BBB) model can provide a reliable tool for better understanding BBB transport mechanisms and in vitro preclinical experimentation. However, recapitulating microenvironmental complexities and physiological functions in an accessible approach remains a major challenge. Here, a new BBB model with a high-cell spatial density and tightly connected biomimetic minitissue is presented. The minitissue, pivotal functional structure of the BBB model, is fabricated by a novel and easy-to-use liquid substrate culture (LSC) method, which allows cells to self-assemble and self-heal into macrosized, tightly connected membranous minitissue. The minitissue with uniform thickness can be easily harvested in their entirety with extracellular matrix. Attributed to the tightly connected minitissue formed by LSC, the fabricated BBB biomimetic model has 1 to 2 orders of magnitude higher transendothelial electric resistance than the commonly reported BBB model. It also better prevents the transmission of large molecular substances, recapitulating the functional features of BBB. Furthermore, the BBB biomimetic model provides feedback regarding BBB-destructive drugs, exhibits selective transmission, and shows efflux pump activity. Overall, this model can serve as an accessible tool for life science or clinical medical researchers to enhance the understanding of human BBB and expedite the development of new brain-permeable drugs.

Perfusable Vessel-on-a-Chip for Antiangiogenic Drug Screening with Coaxial Bioprinting.

Vessel-on-a-chips, which can be used to study microscale fluid dynamics, tissue-level biological molecules delivery and intercellular communication under favorable three-dimensional (3D) extracellular matrix microenvironment, are increasingly gaining traction. However, not many of them can allow for long-term perfusion and easy observation of angiogenesis process. Since angiogenesis is necessary for the expansion of tumor, antiangiogenic drugs play a significant role in cancer treatment. In this study, we established an innovative and reliable antiangiogenic drug screening chip that was highly modularly integrated for long-term perfusion (up to 10 days depending on the hydrogel formula) and real-time monitoring. To maintain an unobstructed flow of cell-laden tubes for subsequent perfusion culture on the premise of excellent bioactivities, a polycaprolactone stent inspired by coronary artery stents was introduced to hold up the tubular lumen from the inside, while the perfusion chip was also elaborately designed to allow for convenient observation. After 3 days of perfusion screening, distinct differences in human umbilical vein endothelial cell sprouting were observed for a gradient of concentrations of bevacizumab, which pointed to the effectiveness and reliability of the drug screening perfusion system. Overall, a perfusion system for antiangiogenic drug screening was developed, which can not only conduct drug evaluation, but also be potentially useful in other vessel-mimicking scenarios in the area of tissue engineering, drug screening, pharmacokinetics, and regenerative medicine.

A circulating subset of iNKT cells mediates antitumor and antiviral immunity.

Invariant natural killer T (iNKT) cells are a group of innate-like T lymphocytes that recognize lipid antigens. They are supposed to be tissue resident and important for systemic and local immune regulation. To investigate the heterogeneity of iNKT cells, we recharacterized iNKT cells in the thymus and peripheral tissues. iNKT cells in the thymus were divided into three subpopulations by the expression of the natural killer cell receptor CD244 and the chemokine receptor CXCR6 and designated as C0 (CD244-CXCR6-), C1 (CD244-CXCR6+), or C2 (CD244+CXCR6+) iNKT cells. The development and maturation of C2 iNKT cells from C0 iNKT cells strictly depended on IL-15 produced by thymic epithelial cells. C2 iNKT cells expressed high levels of IFN-γ and granzymes and exhibited more NK cell-like features, whereas C1 iNKT cells showed more T cell-like characteristics. C2 iNKT cells were influenced by the microbiome and aging and suppressed the expression of the autoimmune regulator AIRE in the thymus. In peripheral tissues, C2 iNKT cells were circulating that were distinct from conventional tissue-resident C1 iNKT cells. Functionally, C2 iNKT cells protected mice from the tumor metastasis of melanoma cells by enhancing antitumor immunity and promoted antiviral immune responses against influenza virus infection. Furthermore, we identified human CD244+CXCR6+ iNKT cells with high cytotoxic properties as a counterpart of mouse C2 iNKT cells. Thus, this study reveals a circulating subset of iNKT cells with NK cell-like properties distinct from conventional tissue-resident iNKT cells.

The NEDD8-activating enzyme inhibitor MLN4924 reduces ischemic brain injury in mice.

Blood-brain barrier (BBB) breakdown and inflammation occurring at the BBB have a key, mainly a deleterious role in the pathophysiology of ischemic stroke. Neddylation is a ubiquitylation-like pathway that is critical in various cellular functions by conjugating neuronal precursor cell-expressed developmentally down-regulated protein 8 (NEDD8) to target proteins. However, the roles of neddylation pathway in ischemic stroke remain elusive. Here, we report that NEDD8 conjugation increased during acute phase after ischemic stroke and was present in intravascular and intraparenchymal neutrophils. Inhibition of neddylation by MLN4924, also known as pevonedistat, inactivated cullin-RING E3 ligase (CRL), and reduced brain infarction and improved functional outcomes. MLN4924 treatment induced the accumulation of the CRL substrate neurofibromatosis 1 (NF1). By using virus-mediated NF1 silencing, we show that NF1 knockdown abolished MLN4924-dependent inhibition of neutrophil trafficking. These effects were mediated through activation of endothelial P-selectin and intercellular adhesion molecule-1 (ICAM-1), and blocking antibodies against P-selectin or anti-ICAM-1 antibodies reversed NF1 silencing-induced increase in neutrophil infiltration in MLN4924-treated mice. Furthermore, we found that NF1 silencing blocked MLN4924-afforded BBB protection and neuroprotection through activation of protein kinase C δ (PKCδ), myristoylated alanine-rich C-kinase substrate (MARCKS), and myosin light chain (MLC) in cerebral microvessels after ischemic stroke, and treatment of mice with the PKCδ inhibitor rottlerin reduced this increased BBB permeability. Our study demonstrated that increased neddylation promoted neutrophil trafficking and thus exacerbated injury of the BBB and stroke outcomes. We suggest that the neddylation inhibition may be beneficial in ischemic stroke.

High-Frequency 0.36BiScO3-0.64PbTiO3 Ultrasonic Transducer for High-Temperature Imaging Application.

( 1- x )BiScO3- x PbTiO3 (BS-PT) ceramics have excellent piezoelectricity and high Curie temperature at its morphotropic phase boundary (MPB) ( x = 0.64 ), so it is a promising piezoelectric material for fabricating high-temperature ultrasonic transducer (HTUT). Electric properties of 0.36BS-0.64PT ceramics were characterized at different temperatures, and an HTUT with the center frequency of about 15 MHz was designed by PiezoCAD based on the measuring results. The prepared HTUT was tested in a silicone oil bath at different temperatures systematically. The test results show that the HTUT can maintain a stable electrical resonance until 290 °C and get a clear echo response until 250 °C with slight changes of the center frequency. Then, a stepped metal block submerged in silicone oil was imaged by the HTUT until 250 °C. Velocity of silicone oil and axial resolution of the HTUT at different temperatures was calculated. The results verify the capability of 0.36BS-0.64PT-based HTUT for high-temperature ultrasonic imaging applications.

Neutrophil extracellular traps promote tPA-induced brain hemorrhage via cGAS in mice with stroke.

Intracerebral hemorrhage associated with thrombolytic therapy with tissue plasminogen activator (tPA) in acute ischemic stroke continues to present a major clinical problem. Here, we report that infusion of tPA resulted in a significant increase in markers of neutrophil extracellular traps (NETs) in the ischemic cortex and plasma of mice subjected to photothrombotic middle cerebral artery occlusion. Peptidylarginine deiminase 4 (PAD4), a critical enzyme for NET formation, is also significantly upregulated in the ischemic brains of tPA-treated mice. Blood-brain barrier (BBB) disruption after ischemic challenge in an in vitro model of BBB was exacerbated after exposure to NETs. Importantly, disruption of NETs by DNase I or inhibition of NET production by PAD4 deficiency restored tPA-induced loss of BBB integrity and consequently decreased tPA-associated brain hemorrhage after ischemic stroke. Furthermore, either DNase I or PAD4 deficiency reversed tPA-mediated upregulation of the DNA sensor cyclic GMP-AMP (cGAMP) synthase (cGAS). Administration of cGAMP after stroke abolished DNase I-mediated downregulation of the STING pathway and type 1 interferon production and blocked the antihemorrhagic effect of DNase I in tPA-treated mice. We also show that tPA-associated brain hemorrhage after ischemic stroke was significantly reduced in cGas-/- mice. Collectively, these findings demonstrate that NETs significantly contribute to tPA-induced BBB breakdown in the ischemic brain and suggest that targeting NETs or cGAS may ameliorate thrombolytic therapy for ischemic stroke by reducing tPA-associated hemorrhage.

Particle Swarm Optimization Algorithm-Based Design Method for Ultrasonic Transducers.

In order to improve the fabrication efficiency and performance of an ultrasonic transducer (UT), a particle swarm optimization (PSO) algorithm-based design method was established and combined with an electrically equivalent circuit model. The relationship between the design and performance parameters of the UT is described by an electrically equivalent circuit model. Optimality criteria were established according to the desired performance; then, the design parameters were iteratively optimized using a PSO algorithm. The Pb(ZrxTi1-x)O3 (PZT) ceramic UT was designed by the proposed method to verify its effectiveness. A center frequency of 6 MHz and a bandwidth of -6 dB (70%) were the desired performance characteristics. The optimized thicknesses of the piezoelectric and matching layers were 255 µm and 102 µm. The experimental results agree with those determined by the equivalent circuit model, and the center frequency and -6 dB bandwidth of the fabricated UT were 6.3 MHz and 68.25%, respectively, which verifies the effectiveness of the developed optimization design method.

Neutrophil extracellular traps released by neutrophils impair revascularization and vascular remodeling after stroke.

Neovascularization and vascular remodeling are functionally important for brain repair after stroke. We show that neutrophils accumulate in the peri-infarct cortex during all stages of ischemic stroke. Neutrophils producing intravascular and intraparenchymal neutrophil extracellular traps (NETs) peak at 3-5 days. Neutrophil depletion reduces blood-brain barrier (BBB) breakdown and enhances neovascularization at 14 days. Peptidylarginine deiminase 4 (PAD4), an enzyme essential for NET formation, is upregulated in peri-ischemic brains. Overexpression of PAD4 induces an increase in NET formation that is accompanied by reduced neovascularization and increased BBB damage. Disruption of NETs by DNase 1 and inhibition of NET formation by genetic ablation or pharmacologic inhibition of PAD increases neovascularization and vascular repair and improves functional recovery. Furthermore, PAD inhibition reduces stroke-induced STING-mediated production of IFN-ß, and STING knockdown and IFN receptor-neutralizing antibody treatment reduces BBB breakdown and increases vascular plasticity. Collectively, our results indicate that NET release impairs vascular remodeling during stroke recovery.

IL-7R-Dependent Phosphatidylinositol 3-Kinase Competes with the STAT5 Signal to Modulate T Cell Development and Homeostasis.

T cell development and homeostasis requires IL-7R α-chain (IL-7Rα) signaling. Tyrosine Y449 of the IL-7Rα is essential to activate STAT5 and PI3K, whereas PI3K recruitment requires IL-7Rα methionine M452. How IL-7Rα activates and regulates both signaling pathways differentially remains unclear. To characterize differential signaling, we established two lines of IL-7Rα mutant mice: IL-7R-Y449F mice and IL-7R-M452L mice. IL-7R-Y449F mice showed decreased PI3K and STAT5 signals, whereas IL-7R-M452L mice showed decreased PI3K but significantly increased STAT5 signaling, owing to a competition between PI3K and STAT5 signaling through Y449 of IL-7Rα. The number of T, B, and mature innate lymphoid cells were markedly reduced in IL-7R-Y449F mice, whereas IL-7R-M452L mice showed impaired early T cell development and memory precursor effector T cell maintenance with the downregulation of transcription factor T cell factor-1. Peripheral T cell numbers increased in IL-7R-M452L mice with enhanced survival and homeostatic proliferation. Furthermore, although wild type and IL-7R-Y449F mice showed comparable Th1/Th2 differentiation, IL-7R-M452L mice exhibited impaired Th17 differentiation. We conclude that PI3K competes with STAT5 under IL-7Rα and maintains an appropriate signal balance for modulating T cell development and homeostasis. To our knowledge, this study provides a new insight into complex regulation of IL-7Rα signaling, which supports immune development and responses.

Intestinal epithelial cell-derived IL-15 determines local maintenance and maturation of intra-epithelial lymphocytes in the intestine.

Interleukin-15 (IL-15) is a cytokine critical for maintenance of intestinal intra-epithelial lymphocytes (IELs), especially CD8αα + IELs (CD8αα IELs). In the intestine, IL-15 is produced by intestinal epithelial cells (IECs), blood vascular endothelial cells (BECs) and hematopoietic cells. However, the precise role of intestinal IL-15 on IELs is still unknown. To address the question, we generated two kinds of IL-15 conditional knockout (IL-15cKO) mice: villin-Cre (Vil-Cre) and Tie2-Cre IL-15cKO mice. IEC-derived IL-15 was specifically deleted in Vil-Cre IL-15cKO mice, whereas IL-15 produced by BECs and hematopoietic cells was deleted in Tie2-Cre IL-15cKO mice. The cell number and frequency of CD8αα IELs and NK IELs were significantly reduced in Vil-Cre IL-15cKO mice. By contrast, CD8αα IELs were unchanged in Tie2-Cre IL-15cKO mice, indicating that IL-15 produced by BECs and hematopoietic cells is dispensable for CD8αα IELs. Expression of an anti-apoptotic factor, Bcl-2, was decreased, whereas Fas expression was increased in CD8αα IELs of Vil-Cre IL-15cKO mice. Forced expression of Bcl-2 by a Bcl-2 transgene partially restored CD8αα IELs in Vil-Cre IL-15cKO mice, suggesting that some IL-15 signal other than Bcl-2 is required for maintenance of CD8αα IELs. Furthermore, granzyme B production was reduced, whereas PD-1 expression was increased in CD8αα IELs of Vil-Cre IL-15cKO mice. These results collectively suggested that IEC-derived IL-15 is essential for homeostasis of IELs by promoting their survival and functional maturation.

ADAMTS13 maintains cerebrovascular integrity to ameliorate Alzheimer-like pathology.

Blood-brain barrier (BBB) defects and cerebrovascular dysfunction contribute to amyloid-ß (Aß) brain accumulation and drive Alzheimer disease (AD) pathology. By regulating vascular functions and inflammation in the microvasculature, a disintegrin and metalloprotease with thrombospondin type I motif, member 13 (ADAMTS13) plays a significant protective effect in atherosclerosis and stroke. However, whether ADAMTS13 influences AD pathogenesis remains unclear. Using in vivo multiphoton microscopy, histological, behavioral, and biological methods, we determined BBB integrity, cerebrovascular dysfunction, amyloid accumulation, and cognitive impairment in APPPS1 mice lacking ADAMTS13. We also tested the impact of viral-mediated expression of ADAMTS13 on cerebrovascular function and AD-like pathology in APPPS1 mice. We show that ADAMTS13 deficiency led to an early and progressive BBB breakdown as well as reductions in vessel density, capillary perfusion, and cerebral blood flow in APPPS1 mice. We found that deficiency of ADAMTS13 increased brain plaque load and Aß levels and accelerated cerebral amyloid angiopathy (CAA) by impeding BBB-mediated clearance of brain Aß, resulting in worse cognitive decline in APPPS1 mice. Virus-mediated expression of ADAMTS13 attenuated BBB disruption and increased microvessels, capillary perfusion, and cerebral blood flow in APPPS1 mice already showing BBB damage and plaque deposition. These beneficial vascular effects were reflected by increase in clearance of cerebral Aß, reductions in Aß brain accumulation, and improvements in cognitive performance. Our results show that ADAMTS13 deficiency contributes to AD cerebrovascular dysfunction and the resulting pathogenesis and cognitive deficits and suggest that ADAMTS13 may offer novel therapeutic opportunities for AD.

Oncogenic MSH6-CXCR4-TGFB1 Feedback Loop: A Novel Therapeutic Target of Photothermal Therapy in Glioblastoma Multiforme.

Glioblastoma multiforme (GBM) has been considered the most aggressive glioma type. Temozolomide (TMZ) is the main first-line chemotherapeutic agent for GBM. Decreased mutS homolog 6 (MSH6) expression is clinically recognized as one of the principal reasons for GBM resistance to TMZ. However, the specific functions of MSH6 in GBM, in addition to its role in mismatch repair, remain unknown. Methods: Bioinformatics were employed to analyze MSH6 mRNA and protein levels in GBM clinical samples and to predict the potential cancer-promoting functions and mechanisms of MSH6. MSH6 levels were silenced or overexpressed in GBM cells to assess its functional effects in vitro and in vivo. Western blot, qRT-PCR, and immunofluorescence assays were used to explore the relevant molecular mechanisms. Cu2(OH)PO4@PAA nanoparticles were fabricated through a hydrothermal method. Their MRI and photothermal effects as well as their effect on restraining the MSH6-CXCR4-TGFB1 feedback loop were investigated in vitro and in vivo. Results: We demonstrated that MSH6 is an overexpressed oncogene in human GBM tissues. MSH6, CXCR4 and TGFB1 formed a triangular MSH6-CXCR4-TGFB1 feedback loop that accelerated gliomagenesis, proliferation (G1 phase), migration and invasion (epithelial-to-mesenchymal transition; EMT), stemness, angiogenesis and antiapoptotic effects by regulating the p-STAT3/Slug and p-Smad2/3/ZEB2 signaling pathways in GBM. In addition, the MSH6-CXCR4-TGFB1 feedback loop was a vital marker of GBM, making it a promising therapeutic target. Notably, photothermal therapy (PTT) mediated by Cu2(OH)PO4@PAA + near infrared (NIR) irradiation showed outstanding therapeutic effects, which might be associated with a repressed MSH6-CXCR4-TGFB1 feedback loop and its downstream factors in GBM. Simultaneously, the prominent MR imaging (T1WI) ability of Cu2(OH)PO4@PAA could provide visual guidance for PTT. Conclusions: Our findings indicate that the oncogenic MSH6-CXCR4-TGFB1 feedback loop is a novel therapeutic target for GBM and that PTT is associated with the inhibition of the MSH6-CXCR4-TGFB1 loop.

Preparation and properties of multifunctional sinapic acid corn bran arabinoxylan esters.

In the present study, corn bran arabinoxylan (CAX) were modified with sinapic acid (SA) by esterification to generate sinapic acid corn bran arabinoxylan esters (SA-CAX) with various substituted degrees. The structure of SA-CAX was characterized by FT-IR, NMR and UV spectroscopy. And the antioxidant activities of SA-CAX were evaluated by scavenging the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical, emulsion lipid oxidation test and the lipid peroxidant level test. Compared with CAX, SA-CAX exhibited superior antioxidant activities in vitro, which indicated that the attachment of SA to CAX could enhance antioxidant activities of CAX. Moreover, the aqueous solution behavior of CAX and SA-CAX was investigated by light scattering, scanning electron microscopy and rheological measurement. The SA-CAX could form the aggregates even at diluted solutions. The hydrophobic association led to a higher viscosity and stronger gel behavior of the SA-CAX aqueous solution than that of CAX aqueous solution.

ADAMTS13 controls vascular remodeling by modifying VWF reactivity during stroke recovery.

Angiogenic response is essential for ischemic brain repair. The von Willebrand factor (VWF)-cleaving protease disintegrin and metalloprotease with thrombospondin type I motif, member 13 (ADAMTS13) is required for endothelial tube formation in vitro, but there is currently no in vivo evidence supporting a function of ADAMTS13 in angiogenesis. Here we show that mice deficient in ADAMTS13 exhibited reduced neovascularization, brain capillary perfusion, pericyte and smooth muscle cell coverage on microvessels, expression of the tight junction and basement membrane proteins, and accelerated blood-brain barrier (BBB) breakdown and extravascular deposits of serum proteins in the peri-infarct cortex at 14 days after stroke. Deficiency of VWF or anti-VWF antibody treatment significantly increased microvessels, perfused capillary length, and reversed pericyte loss and BBB changes in Adamts13-/- mice. Furthermore, we observed that ADAMTS13 deficiency decreased angiopoietin-2 and galectin-3 levels in the isolated brain microvessels, whereas VWF deficiency had the opposite effect. Correlating with this, overexpression of angiopoietin-2 by adenoviruses treatment or administration of recombinant galectin-3 normalized microvascular reductions, pericyte loss, and BBB breakdown in Adamts13-/- mice. The vascular changes induced by angiopoietin-2 overexpression and recombinant galectin-3 treatment in Adamts13-/- mice were abolished by the vascular endothelial growth factor receptor-2 antagonist SU1498. Importantly, treating wild-type mice with recombinant ADAMTS13 at 7 days after stroke markedly increased neovascularization and vascular repair and improved functional recovery at 14 days. Our results suggest that ADAMTS13 controls key steps of ischemic vascular remodeling and that recombinant ADAMTS13 is a putative therapeutic avenue for promoting stroke recovery.