The first ER-targeting flavone-based fluorescent probe for Cys: Applications in real-time tracking in an epilepsy model and food analysis.

Epilepsy is one of the most commonly-seen neurological disorders, and both endoplasmic reticulum stress (ERS) and oxidative stress (OS) have been demonstrated to be associated with epileptic seizures. As one of the three endogenous thiol-containing amino acids, cysteine (Cys) is recognized not only as an important biomarker of various biological processes but also widely used as a significant additive in the food industry. However, the exact role that Cys plays in ERS has not been well answered up to now. In this paper, we reported the first flavone-based fluorescent probe (namely BFC) with nice endoplasmic reticulum (ER)-targeting ability, which was capable of monitoring Cys in a fast response (3.0 min), large stokes shift (130 nm) and low detection limit (10.4 nM). The recognition mechanism of Cys could be attributed to the addition-cyclization reaction involving a Cys residue and an acrylate group, resulting in the release of the strong excited-state intramolecular proton transfer (ESIPT) emission molecule of benzoflavonol (BF). The low cytotoxicity and good biocompatibility of the probe BFC allowed for monitoring the fluctuation of endogenous Cys levels under both ERS and OS processes, as well as in zebrafish models of epilepsy. Quantitative determination of Cys with the probe BFC was also achieved in three different food samples. Additionally, a probe-immersed test strips integrated with a smartphone device was successfully constructed for on-site colorimetric detection of Cys. Undoubtedly, our work provided a valuable tool for tracking Cys levels in both an epilepsy model and real food samples.

A novel LD-targeting cysteine-activated fluorescent probe for diagnosis of APAP-induced liver injury and its application in food analysis.

Cysteine (Cys) not only plays an indispensable role in maintaining the redox balance in organisms, but is also an important nutrient in the food industry. Fluorescence-based detection systems have emerged as an effective method to track the locations and concentrations of different species. To achieve efficient monitoring of Cys in both food samples and biological systems, a novel lipid droplet (LD) targeted fluorescent probe (namely NIT-Cys) was constructed for the turn-on detection of Cys, characterized by a large Stokes shift (142 nm), a short response time (<8 min), and a low Cys detection limit (39 nM). Furthermore, the NIT-Cys probe has been successfully used not only to quantify the amounts of Cys in selected food samples, but also to enable the visualization of endogenous Cys in acetaminophen (APAP)-induced drug-induced liver injury cells, zebrafish larvae and mice models. Consequently, the work presented here provides an efficient tool for monitoring Cys.

Real-time monitoring of endogenous cysteine in LPS-induced oxidative stress process with a novel lysosome-targeted fluorescent probe.

Cysteine (Cys), one of essential small-molecule-based biothiols in the human body, contributes to the regulation of redox reactions and is closely associated with many physiological and pathological metabolic processes. Herein, a novel fluorescent probe, hydroxyphenyl-conjugated benzothiazole (HBT-Cys) capable of detecting Cys was constructed, where acrylate served as the recognition group and hydroxyphenyl-linked benzothiazole acted as the fluorophore. The fluorescence of the probe was negligible in the absence of Cys, and an intense blue fluorescence was observed upon addition of Cys. The Cys-sensing mechanism could be ascribed to the Cys-involved hydrolysis reaction with acrylate, leading to light up the emission at 430 nm with about 80-fold enhancement. In addition, HBT-Cys exhibited a fast response time, remarkable selectivity and low detection limit. HBT-Cys also worked well in real-time monitoring of Cys in three different food samples (wolfberry, hawthorn, and red dates). Importantly, our probe had an excellent lysosomes-targeted ability, which was successfully employed to real-time visualize the fluctuation of both exogenous and endogenous Cys in living cells and zebrafish under lipopolysaccharide (LPS)-induced oxidative stress. Hopefully, the work shown here provides a potent candidate for the real-time tracking of Cys fluctuations in various biological samples.

Characterization of Global Research Trends and Prospects on Moyamoya Disease: Bibliometric Analysis.

BACKGROUND: Moyamoya disease (MMD) is a rare cerebrovascular disease in neurology. This study investigates the literature related to MMD from its discovery to the present and identifies research levels, achievements, and trends. METHODS: All publications on MMD from its discovery to present were downloaded from the Web of Science Core Collection on September 15, 2022 and bibliometric analyses were visualized by HistCite Pro, VOSviewer, Scimago Graphica, CiteSpace, and R language. RESULTS: There were 3414 articles in 680 journals by 10,522 authors in 2441 institutions and 74 countries/regions worldwise are included in the analyses. Since the discovery of MMD, output of publications has shown an upward trend. Japan, the United States, China, and South Korea are 4 major countries in MMD. The United States has the strongest cooperation with other countries. China's Capital Medical University is the output-leading institution worldwide, followed by Seoul National University and Tohoku University. The 3 authors with the most published articles are Kiyohiro Houkin, Dong Zhang, and Satoshi Kuroda. World Neurosurgery, Neurosurgery, and Stroke are the most recognized journals for researchers. Hemorrhagic moyamoya disease, susceptibility gene, and arterial spin are the primary focus areas of MMD research. "Rnf213,""vascular disorder," and "progress" are the top keywords. CONCLUSIONS: We analyzed publications of global scientific research on MMD systematically by bibliometric methods. This study can provide one of the most comprehensive and accurate analyses for MMD scholars worldwide.

Serum inflammatory cell adhesion molecules predict malignant cerebral edema and clinical outcome early after mechanical thrombectomy in stroke.

BACKGROUND: Early prediction of life-threatening malignant cerebral edema (MCE) after mechanical thrombectomy (MT) is of clinical importance. Although inflammatory cell adhesion molecules (CAMs) and anti-inflammation factor Kruppel-like transcription factor (KLF) 4 are induced after acute ischemic stroke (AIS), the relationship between expressions of these molecules after MT and MCE as well as outcome in AIS patients have rarely been explored. METHODS: We retrospectively reviewed the data of all AIS patients with large-vessel occlusion in anterior circulation who underwent MT from our stroke centers. The serum levels of CAMs and KLF4 were determined at 12 h after MT. MCE was assessed on follow-up head computed tomography within 5 days after MT. RESULTS: Of 91 included patients, 18 (19.8 %) patients experienced MCE. Patients with MCE were more likely to have higher levels of E-selectin and inter-cellular adhesion molecule 1 (ICAM-1) than those without MCE (P < 0.05). More specifically, elevated E-selectin, but not of vascular cell adhesion molecule 1 (VCAM-1), ICAM-1 and KLF4, was significantly associated with MCE after adjusting for hypertension, admission NIHSS, Alberta Stroke Program Early CT Scores, serum glucose, collateral circulation and onset to recanalization time respectively (P < 0.05). ROC curve suggested that E-selectin had considerable discrimination to predict MCE (AUC=0.7, 95 % CI: 0.55-0.83). Moreover, after adjusting by confounders, serum levels of E-selectin and ICAM-1 were independently associated with 3-month outcome in AIS patients after MT (both P < 0.05). CONCLUSIONS: These data indicate that of three CAMs, serum E-selectin level early after MT is the best predictor for MCE and outcome in AIS.

Interactions Between Meropenem and Renal Drug Transporters.

BACKGROUND: Meropenem is a carbapenem antibiotic and is commonly used with other antibiotics for the treatment of bacterial infections. It is primarily eliminated renally by glomerular filtration and renal tubular secretion. OBJECTIVE: This study aimed to evaluate the roles of renal uptake and efflux transporters in the excretion of meropenem and potential drug interactions mediated by renal drug transporters. METHODS: Uptake and inhibition studies were conducted in human embryonic kidney 293 cells stably transfected with Organic Anion Transporter (OAT) 1, OAT3, Multidrug and Toxin Extrusion Protein (MATE) 1, and MATE2K, as well as membrane vesicles containing breast cancer resistance-related protein (BCRP), multidrug resistance protein 1 (MDR1), and Multidrug Resistance-associated Protein 2 (MRP2). Probenecid and piperacillin were used to assess potential drug interactions with meropenem in rats. RESULTS: We observed that meropenem was a low-affinity substrate of OAT1/3 and had a weak inhibitory effect on OAT1/3 and MATE2K. BCRP, MDR1, MRP2, MATE1, and MATE2K could not mediate renal excretion of meropenem. Moreover, meropenem was not an inhibitor of BCRP, MDR1, MRP2, or MATE1. Among five tested antibiotics, moderate inhibition on OAT3-mediated meropenem uptake was observed for linezolid (IC50 value was 69.2 µM), weak inhibition was observed for piperacillin, benzylpenicillin, and tazobactam (IC50 values were 282.2, 308.0 and 668.1 µM, respectively), and no inhibition was observed for sulbactam. Although piperacillin had a relatively high drug-drug interaction index (ratio of maximal unbound plasma concentration to IC50 was 1.42) in vitro, no meaningful impact was reported on the pharmacokinetics of meropenem in rats. CONCLUSION: Our results indicated that clinically significant interactions between meropenem and these five antibiotics are low.

Upregulation of circ-FBL promotes myogenic proliferation in myasthenia gravis by regulation of miR-133/PAX7.

Myasthenia gravis (MG) is a disease involving neuromuscular transmission that causes fatigue of skeletal muscles and fluctuating weakness. It has been shown that impairment of myogenic differentiation and myofiber maturation may be the underlying cause of MG. In this study, we detected the abnormal expression of circular RNA (circRNA) using next-generation sequencing in patients with MG. We then investigated the regulatory mechanism and the relationship among circRNA, microRNA, and messenger RNA using quantitative reverse-transcription polymerase chain reaction, bioinformatics analysis, and luciferase report analysis. The expression of inflammatory cytokines and regulatory T lymphocytes was shown to be increased. Circ-FBL was significantly increased in MG patients. Bioinformatics and luciferase report analyses confirmed that miR-133 and PAX7 were the downstream targets of circ-FBL. Overexpression of circ-FBL promoted myoblast proliferation by regulation of miR-133/PAX7. Taken together, our study showed that upregulation of circ-FBL promoted myogenic proliferation in patients with MG by regulating miR-133/PAX7.

Baicalin and the liver-gut system: Pharmacological bases explaining its therapeutic effects.

With the development of high-throughput screening and bioinformatics technology, natural products with a range of pharmacological targets in multiple diseases have become important sources of new drug discovery. These compounds are derived from various plants, including the dried root of Scutellaria baicalensis Georgi, which is often used as a traditional Chinese herb named Huangqin, a popular medication used for thousands of years in China. Many studies have shown that baicalin, an extract from Scutellaria baicalensis Georgi, exerts various protective effects on liver and gut diseases. Baicalin plays a therapeutic role mainly by mediating downstream apoptosis and immune response pathways induced by upstream oxidative stress and inflammation. During oxidative stress regulation, PI3K/Akt/NRF2, Keap-1, NF-κB and HO-1 are key factors associated with the healing effects of baicalin on NAFLD/NASH, ulcerative colitis and cholestasis. In the inflammatory response, IL-6, IL-1ß, TNF-α, MIP-2 and MIP-1α are involved in the alleviation of NAFLD/NASH, cholestasis and liver fibrosis by baicalin, as are TGF-ß1/Smads, STAT3 and NF-κB. Regarding the apoptosis pathway, Bax, Bcl-2, Caspase-3 and Caspase-9 are key factors related to the suppression of hepatocellular carcinoma and attenuation of liver injury and colorectal cancer. In addition to immune regulation, PD-1/PDL-1 and TLR4-NF-κB are correlated with the alleviation of hepatocellular carcinoma, ulcerative colitis and colorectal cancer by baicalin. Moreover, baicalin regulates intestinal flora by promoting the production of SCFAs. Furthermore, BA is involved in the interactions of the liver-gut axis by regulating TGR5, FXR, bile acids and the microbiota. In general, a comprehensive analysis of this natural compound was conducted to determine the mechanism by which it regulates bile acid metabolism, the intestinal flora and related signaling pathways, providing new insights into the pharmacological effects of baicalin. The mechanism linking the liver and gut systems needs to be elucidated to draw attention to its great clinical importance.

Overexpression of α5ß1 integrin and angiopoietin-1 co-operatively promote blood-brain barrier integrity and angiogenesis following ischemic stroke.

We previously demonstrated that cross-talk between α5ß1 integrin and the angiopoietin-1 (Ang1) / Tie2 receptor plays an important role in regulating brain endothelial angiogenic responses in the ischemic penumbra following cerebral ischemic stroke (CIS). However, a recent study suggested that stimulation of the α5ß1 integrin also has the potential of increasing blood-brain barrier (BBB) permeability after CIS, raising doubt about whether α5ß1 integrin stimulation by itself will protect against ischemic injury. In light of these conflicting roles, the goal of this study was to evaluate the impact of co-overexpression of α5 integrin and Ang1 on vascular remodeling and repair under cerebral ischemic conditions both in vivo following 90 min of ischemia by temporary occlusion of the middle cerebral artery, and in vitro. Our results demonstrate that as compared to mock-transfected controls, overexpression of α5 integrin alone didn't improve the outcomes in neurological score and size of infarct and caused worse BBB breakdown in the ischemic hemisphere, offsetting its beneficial angiogenic effects during the early stages of CIS. However, co-overexpression of α5 integrin with Ang1 led to smaller infarcts and improved neurological deficits, which at the molecular level was underpinned by reduced BBB breakdown and increased expression of endothelial tight junction proteins in the ischemic penumbra during the early stages of CIS. Furthermore, co-overexpression of α5 integrin and Ang1 synergistically promoted BEC proliferation during the early stage of CIS, resulting in increased blood vessel density at later stages. Positive effects of α5 integrin and Ang1 co-overexpression on endothelial proliferation and tight junction protein expression were also confirmed in vitro. Collectively, these data indicate that co-overexpression of Ang-1 and α5 integrin in combination confers synergistic vascular protection against cerebral ischemic injury without the negative side effects on BBB permeability, suggesting a novel combinatorial approach for the treatment of CIS.

Integrin α5ß1-Ang1/Tie2 receptor cross-talk regulates brain endothelial cell responses following cerebral ischemia.

We have previously demonstrated that in response to cerebral ischemia (CI), the growth factor angiopoietin-1 (Ang1) and α5ß1 integrin are both induced in cerebral vessels, which likely provide positive signals driving the endogenous angiogenic response and vascular protection after CI. However, the precise relationship between endothelial Ang1 and α5ß1 integrin after CI remains poorly understood. Here, we investigated the effects of the interaction between the Ang1/Tie2 system and α5ß1 integrin on brain endothelial cells (BECs) under cerebral ischemic conditions in vivo and in vitro. Immunofluorescence analysis demonstrated that integrin α5ß1 co-localized with Tie2/phosphorylated Tie2 on cerebral vessels in the penumbra. The in vitro study showed that oxygen-glucose deprivation/restoration (OGD/R) induced the expression of the Ang1 receptor Tie2 on BECs in a manner similar to that for integrin α5 and Ang1 in response to OGD/R, accompanied by increased activation of Tie2 and its downstream effectors focal adhesion kinase (FAK) and Akt. Knockdown of α5 integrin markedly suppressed OGD/R-induced Tie2 receptor activation in BECs, while in contrast, priming BECs with Ang1 promoted the expression of α5 integrin as well as the Tie2 downstream transcription factor Ets-1 in OGD-treated BECs. In line with this, Ets-1 knockdown significantly attenuated Ang1-mediated upregulation of α5 integrin. Functionally, Ang1 induced cell migration and tube formation of BECs after OGD, but this effect was inhibited by diminishment of the levels of α5 integrin in BECs. Taken together, our data indicate that the Ang1/Tie2 system cross-talks with integrin α5ß1 in BECs after CI, which may contribute to the endogenous angiogenic vascular protective response following CI.

Exosomes from MiR-30d-5p-ADSCs Reverse Acute Ischemic Stroke-Induced, Autophagy-Mediated Brain Injury by Promoting M2 Microglial/Macrophage Polarization.

BACKGROUND/AIMS: Recent studies have indicated that exosomes secreted from adipose-derived stem cells (ADSCs) have important effects in the treatment of ischemic injury. However, the treatment mechanism is unclear. This study aimed to investigate whether ADSC-derived exosomes enriched with microRNA (miR)-30d-5p have a protective effect on acute ischemic stroke (AIS). METHODS: In the current study, inflammatory factors and miR-30d-5p expression were assessed in 70 subjects with AIS and 35 healthy controls. Exosomes were characterized by transmission electron microscopy and further examined using nanoparticle tracking analyses. A rat model of AIS and an in vitro model of oxygen- and glucose-deprived (OGD) primary microglia were established to study the protective mechanism of exosomes from miR-30d-5p-overexpressing ADSCs in ischemia-induced nerve injury. RESULTS: The results showed that following AIS, the expression of inflammatory cytokines increased, while the anti-inflammatory cytokines IL-4, IL-10, and miR-30d-5p decreased both in patients and in animal models. Moreover, in vitro studies demonstrated that suppression of autophagy significantly reduced the OGD-induced inflammatory response. In addition, exosome treatment was more effective in suppressing the inflammatory response by reversing OGD-induced and autophagy-mediated microglial polarization to M1. Furthermore, in vivo studies showed that exosomes derived from ADSCs significantly decreased the cerebral injury area of infarction by suppressing autophagy and promoting M2 microglia/macrophage polarization. CONCLUSIONS: Our results suggest that miR-30d-5p-enhanced ADSC-derived exosomes prevent cerebral injury by inhibiting autophagy-mediated microglial polarization to M1.

Downregulation of circ_008018 protects against cerebral ischemia-reperfusion injury by targeting miR-99a.

Circular RNAs (circRNAs) are highly expressed in eukaryotic cells and regulate physiological and pathophysiological processes. However, the role of circRNAs in cerebral ischemia-reperfusion (I/R) injury remains largely unknown. In this study, we found that circ_008018 level was higher in the cortical tissue of mice with middle cerebral artery occlusion as compared to those in the sham group 24 h after reperfusion. Knockdown of circ_008018 attenuated cerebral I/R-induced brain tissue damage and neurological deficits in mice by inducing microRNA miR-99a overexpression. The decreased phosphorylation of Akt and glycogen synthase kinase 3ß caused by I/R was partly reversed by circ_008018 silencing or miR-99a overexpression. Taken together, these results provide new insight into the mechanisms of apoptosis resulting from cerebral I/R injury and suggest that targeted inhibition of circ_008018 can protect against subsequent neurological damage.

Hepatitis B virus inhibits the in vivo and in vitro synthesis and secretion of apolipoprotein C3.

BACKGROUND: Hepatitis B virus (HBV) infection in the body can damage liver cells and cause disorders in blood lipid metabolism. Apolipoprotein C3 (ApoC3) plays an important role in the regulation of lipid metabolism, but no study on the HBV regulation of ApoC3 has been reported. This purpose of this study was to investigate the effect of HBV on ApoC3 expression and its regulatory mechanism. METHODS: The expression levels of ApoC3 mRNA and protein in the human hepatoma cell lines HepG2 and HepG2.2.15 were determined using real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot. The HepG2 cells were co-transfected with the ApoC3 gene promoter and either HBV-infected clone pHBV1.3 or its individual genes. The changes in luciferase activity were assayed. The expression levels of ApoC3 mRNA and protein were determined using RT-qPCR and Western blot. The content of ApoC3 in the supernatant of the cultured cells was determined using an enzyme-linked immunosorbent assay (ELISA). The sera were collected from 149 patients with HBV infection and 102 healthy subjects at physical examination as the normal controls. The serological levels of ApoC3 in the HBV group and the normal control group were determined using ELISA. The contents of serum triglyceride (TG) and very-low-density lipoprotein (VLDL) in the HBV patients and the normal control were determined using an automatic biochemical analyser. RESULTS: The expression levels of ApoC3 mRNA and protein were lower in the HepG2.2.15 cells than in the HepG2 cells. pHBV1.3 and its X gene could inhibit the activity of the ApoC3 promoter and its mRNA and protein expression. The serum levels of ApoC3, VLDL and TG were 65.39 ± 7.48 µg/ml, 1.24 ± 0.49 mmol/L, and 0.46 ± 0.10 mmol/L in the HBV patients and 41.02 ± 6.88 µg/ml, 0.76 ± 0.21 mmol/L, 0.29 ± 0.05 mmol/L in the normal controls, respectively, statistical analysis revealed significantly lower serum levels of ApoC3, VLDL and TG in HBV patients than in the normal controls (P < 0.05). CONCLUSION: HBV can inhibit the in vivo and in vitro synthesis and secretion of ApoC3.

MicroRNA-93 Regulates Hypoxia-Induced Autophagy by Targeting ULK1.

The expression of the core autophagy kinase, Unc51-like kinase 1 (ULK1), is regulated transcriptionally and translationally by starvation-induced autophagy. However, how ULK1 is regulated during hypoxia is not well understood. Previously, we showed that ULK1 expression is induced by hypoxia stress. Here, we report a new ULK1-modulating microRNA, miR-93; its transcription is negatively correlated with the translation of ULK1 under hypoxic condition. miR-93 targets ULK1 and reduces its protein levels under hypoxia condition. miR-93 also inhibits hypoxia-induced autophagy by preventing LC3-I to LC3-II transition and P62 degradation; these processes are reversed by the overexpression of an endogenous miR-93 inhibitor. Re-expression of ULK1 without miR-93 response elements restores the hypoxia-induced autophagy which is inhibited by miR-93. Finally, we detected the effects of miR-93 on cell viability and apoptosis in noncancer cell lines and cancer cells. We found that miR-93 sustains the viability of MEFs (mouse embryonic fibroblasts) and inhibits its apoptosis under hypoxia. Thus, we conclude that miR-93 is involved in hypoxia-induced autophagy by regulating ULK1. Our results provide a new angle to understand the complicated regulation of the key autophagy kinase ULK1 during different stress conditions.

Cerebral ischemia-induced angiogenesis is dependent on tumor necrosis factor receptor 1-mediated upregulation of α5ß1 and αVß3 integrins.

BACKGROUND: The pro-inflammatory cytokine, tumor necrosis factor-α (TNF-α), is expressed in ischemic tissue and is known to modulate angiogenesis; however, the role of the two distinct TNF-α receptors, TNFR1 and TNFR2, in mediating angiogenic signaling after cerebral ischemic stroke is relatively unknown. METHODS: C57BL6 mice were subject to 90 min of ischemia by temporary occlusion of the middle cerebral artery (MCAO) and given daily intra-cerebroventricular injections of antibodies against TNFR1, TNFR2 or control IgG (doses of 10, 50, and 100 ng/day) for 4 days following 90 min MCAO. Vascular remodeling and α5ß1 and αVß3 integrin expression were then examined in the brains of these mice after 4, 7, and 14 days post-ischemia. In parallel in vitro studies, flow cytometry was used to determine the influence of TNF-α on proliferation and integrin expression of human brain microvascular endothelial cells (HBMECs). RESULTS: The post-ischemic cerebral angiogenic response was inhibited by antibodies against TNFR1 but not TNFR2, and this correlated with reduced endothelial proliferation and decreased α5ß1 and αVß3 integrin expression after 4 and 7 days post-ischemia. Consistent with these findings, in vitro studies showed that TNF-α induced endothelial proliferation and upregulation of α5ß1 and αVß3 integrins was abrogated by anti-TNFR1 but not anti-TNFR2 antibodies in cultured HBMECs. In addition, blocking antibodies to α5ß1 and αVß3 integrins significantly inhibited TNF-α-induced HBMEC proliferation. CONCLUSIONS: Our results suggest that TNFR1-mediated signaling plays a critical role in triggering angiogenic integrins and subsequent angiogenic responses following cerebral ischemia. These novel findings could form a platform for future therapeutic strategies aimed at stimulating angiogenesis following cerebral ischemia.

Multiple organ dysfunction syndrome, an unusual complication of heroin intoxication: a case report and review of literature.

Multiple organ dysfunction syndrome (MODS) has rarely been described in patients with heroin intoxication. Here, we report a rare case of MODS involving six organs, due to heroin intoxication. The patient was a 32-year-old Chinese man with severe heroin intoxication complicated by acute pulmonary edema and respiratory insufficiency, shock, myocardial damage and cardiac insufficiency, rhabdomyolysis and acute renal insufficiency, acute liver injury and hepatic insufficiency, toxic leukoencephalopathy, and hypoglycemia. He managed to survive and was discharged after 10 weeks of intensive care. The possible pathogenesis and therapeutic measures of MODS induced by heroin intoxication and some suggestions for preventing and treating severe complications of heroin intoxication, based on clinical evidence and the pertinent literature, are discussed in this report.

Phosphorylation of ULK1 by AMPK regulates translocation of ULK1 to mitochondria and mitophagy.

UNC-51 like kinase (ULK1) translocates to dysfunctional mitochondria and is involved in mitophagy, but the mechanisms responsible for ULK1 activation and translocation remain unclear. Here, we found that hypoxia induces phosphorylation of ULK1 at Serine-555 by Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK). Unlike wild-type ULK1, an ULK1 (S555A) mutant cannot translocate to mitochondria in response to hypoxia. Inhibition or knockdown of AMPK prevents ULK1 translocation and inhibits mitophagy. Finally, the phospho-mimic ULK1 (S555D) mutant, but not ULK1 (S555A), rescues mitophagy in AMPK-knockdown cells. Thus, we conclude that AMPK-dependent phosphorylation of ULK1 is critical for translocation of ULK1 to mitochondria and for mitophagy in response to hypoxic stress.

Clinical presentation and imaging characteristics of occult lung cancer associated ischemic stroke.

We investigated the clinical and imaging characteristics of initial and recurrent strokes in patients with occult lung cancer associated ischemic stroke (OLCA-stroke). A retrospective review of all ischemic stroke patients with occult lung cancer in the absence of conventional stroke etiologies between 2005 and 2013 was conducted. We compared the initial and recurrent lesion patterns on diffusion-weighted MRI in patients with OLCA-stroke, with respect to vascular territory involved, number and size of lesions, clinical presentation, cancer subtypes, recurrences and fatalities, and outcome of survivors. Thirteen patients with confirmed OLCA-stroke were identified. All had elevated D-dimer levels, six had central lung cancer and seven had peripheral lung cancer. Eight (62%) had adenocarcinoma, and nine (69%) had metastasis. Ten (77%) patients had multiple lesions in multiple vascular territories. Twelve (92%) patients suffered recurrent strokes. Multiple small and large disseminated lesions in multiple vascular territories were more frequent in recurrent strokes in comparison with initial strokes. The middle cerebral artery was most frequently involved in recurrent strokes, followed by the posterior circulation territory and anterior cerebral artery, which were of similar frequency as initial strokes. Overall, 58% of patients had their first recurrent stroke within the first month, and 69% had a poor outcome, especially for those with multiple recurrent strokes and metastases. Occult cancer should be considered in the setting of multiple and recurrent embolic strokes within the short term in the absence of conventional stroke etiologies. The severity of malignancy and cancer treatments and stroke influenced the recurrences and outcome.

Mechanisms mediating propofol protection of pulmonary epithelial cells against lipopolysaccharide-induced cell death.

Propofol (2,6-diisopropylphenol) is an anaesthetic agent with anti-oxidant properties. The aim of the present study was to determine whether propofol can protect pulmonary epithelial (A549) cells against lipopolysaccharide (LPS)-induced cell death and, if so, the mechanisms involved. The effects of LPS alone and in combination with propofol on A549 cell death were investigated. Cell viability was determined using the colourimetric 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Apoptotic A549 cells were detected by flow cytometry, as propidium iodide-negative and annexin-V-positive cells, and terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labelling (TUNEL). Mitochondrial membrane potential (MMP), caspase 9 activity, Ca(2+) concentrations and reactive oxygen species (ROS) were analysed by immunofluorescent methods. Aconitase 2 (ACO2), microtubule-associated light chain 3 (LC3) and beclin-1 levels were evaluated using reverse transcription-polymerase chain reaction and/or western blot analysis. Exposure of A549 cells to 1-50 µg/mL LPS for 3-24 h resulted in the concentration- and time-dependent induction of cell death. Cell apoptosis accounted for approximately 77% of cell death induced by LPS. Propofol (5-150 µmol/L) concentration-dependently inhibited LPS-induced A549 cell death. This protective effect of propofol was accompanied by prevention of LPS-induced mitochondrial dysfunction (reductions in MMP, ACO2 expression and ATP) and was associated with the inhibition of LPS-induced activation of apoptotic signals (caspase 9 activity, ROS overproduction and Ca(2+) accumulation). In addition, propofol blocked LPS-induced overexpression of the autophagy-associated proteins LC3 and beclin-1. The data indicate that propofol protects A549 cells against LPS-induced apoptosis, and probably autophagy, by blocking LPS-induced activation of ROS/caspase 9 pathways and upregulation of LC3 and beclin-1, respectively.

Microglial activation state exerts a biphasic influence on brain endothelial cell proliferation by regulating the balance of TNF and TGF-ß1.

BACKGROUND: Studies of cerebral ischemia and other neuroinflammatory states have demonstrated a strong association between new vessel formation and microglial recruitment and activation, raising the possibility that microglia may be involved in promoting angiogenesis. As endothelial cell proliferation is a fundamental early step in angiogenesis, the aim of this study was to test this hypothesis by examining the influence of microglial secreted factors on brain endothelial cell (BEC) proliferation using BrdU incorporation. METHODS: Primary cultures of mouse BEC, microglia and astrocytes were used in this study. Proliferation of BEC was examined by BrdU incorporation. ELISA was used to quantify TNF and TGF-ß1 levels within cell culture supernatants. RESULTS: Microglia regulated BEC proliferation in a biphasic manner; microglia conditioned medium (MG-CM) from resting microglia inhibited, while that from activated microglia promoted BEC proliferation. A screen of microglial cytokines revealed that BEC proliferation was inhibited by TGF-ß1, but promoted by TNF. ELISA showed that TNF and TGF-ß1 were both present in MG-CM, and that while TGF-ß1 dominated in resting MG-CM, TNF levels were massively increased in activated MG-CM, shifting the balance in favor of TNF. Antibody-blocking studies revealed that the influence of MG-CM to inhibit or promote BEC proliferation was largely attributable to the cytokines TGF-ß1 and TNF, respectively. CONCLUSION: This data suggests that microglial activation state might be an important determinant of cerebral angiogenesis; inhibiting BEC proliferation and neovascularization in the normal central nervous system (CNS), but stimulating the growth of new capillaries under neuroinflammatory conditions.