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Embolic stroke results in a necrotic core of cells destined to die, but also a peri-ischemic, watershed penumbral region of potentially salvageable brain tissue. Approaches to effectively differentiate between the ischemic and peri-ischemic zones is critical for novel therapeutic discovery to improve outcomes in survivors of stroke. MicroRNAs are a class of small non-coding RNAs regulating gene translation that have region- and cell-specific expression and responses to ischemia. We have previously reported that global inhibition of cerebral microRNA200c after experimental stroke in mice is protective, however delineating the post-stroke sub-regional and celltype specific patterns of post-stroke miR-200c expression are necessary to minimize off-target effects and advance translational application. Here, we detail a novel protocol to visualize regional miR-200c expression after experimental stroke, complexed with visualization of regional ischemia and markers of oxidative stress in an experimental stroke model in mice. In the present study we demonstrate that the fluorescent hypoxia indicator pimonidazole hydrochloride, the reactive-oxygen-species marker 8-hydroxy-deoxyguanosine, neuronal marker MAP2 and NeuN, and the reactive astrocyte marker GFAP can be effectively complexed to determine regional differences in ischemic injury as early as 30 min post-reperfusion after experimental stroke, and can be effectively used to distinguish ischemic core from surrounding penumbral and unaffected regions for targeted therapy. This multi-dimensional post-stroke immunofluorescent imaging protocol enables a greater degree of subregional mechanistic investigation, with the ultimate goal of developing more effective post-stroke pharmaceutical therapy.

Brain-enriched microRNA-338 (miR-338) is known to play a central role in brain mitochondrial function, however the role of miR-338 in stroke injury remains unknown. This study investigated the role of miR-338 in injury from transient focal cerebral ischemia in mice, and in cell survival and mitochondrial function after in vitro ischemia in astrocyte and neuronal cultures. Pre-treatment of mice with intracerebroventricular injection of miR-338 antagomir 24 h prior to 1 h of middle cerebral artery occlusion (MCAO) significantly reduced infarct size and improved neurological score at both 24 h and 7d after injury. Levels of the miR-338 target cytochrome-c oxidase subunit 4I1 (COX4I1), which plays an essential role in maintaining brain mitochondrial ATP production, were increased in miR-338 antagomir-treated mice. Mouse primary astrocyte cell cultures subjected to glucose deprivation exhibited increased cell survival when pre-treated with miR-338 inhibitor, and greater cell death with miR-338 mimic. Decreased miR-338 levels were associated with increased ATP production, augmented cytochrome c oxidative (CcO) activity and preservation of COX4I1. In vitro protection with miR-338 inhibitor was blocked by concurrent knockdown of COX4I1 with small interfering RNA. Parallel studies in mouse neuronal N2a cultures resulted in preserved ATP content and CcO activity with miR-338 inhibition, indicating a shared miR-338-dependent response to ischemic stress between brain cell types. These results suggest that miR-338 inhibition and/or COX4I1-targeted therapies may be novel clinical strategies to protect against stroke injury via preservation of mitochondrial function in multiple cell types.

Stroke induces a robust inflammatory response. However, it still lacks a systematic view of the various immune cell types due to the limited numbers of fluorophore used in the traditional FACS technique. In our current study, we utilized the novel technique mass cytometry (CyTOF) to analyze multiple immune cell types. We detected these immune cells from the ischemic brain, peripheral blood, spleen, and bone marrow at different time courses after stroke. Our data showed (1) dynamic changes in the immune cell numbers in the ischemic brain and peripheral organs. (2) The expression levels of cell surface markers indicate the inflammation response status after stroke. Interestingly, CD62L, a key adhesion molecule, regulates the migration of leukocytes from blood vessels into secondary lymphoid tissues and peripheral tissues. (3) A strong leukocyte network across the brain and peripheral immune organs was identified using the R program at day 1 after ischemia, suggesting that the peripheral immune cells dramatically migrated into the ischemic areas after stroke. This study provides a systematic, wide view of the immune components in the brain and peripheral organs for a deep understanding of the immune response after ischemic stroke.

In the present study, we assessed efficacy of exosomes harvested from human and mouse stem cell cultures in protection of mouse primary astrocyte and neuronal cell cultures following in vitro ischemia, and against ischemic stroke in vivo. Cell media was collected from primary mouse neural stem cell (NSC) cultures or from human induced pluripotent stem cell-derived cardiomyocyte (iCM) cultures. Exosomes were extracted and purified by polyethylene glycol complexing and centrifugation, and exosome size and concentration were determined with a NanoSiteTM particle analyzer. Exosomes were applied to primary mouse cortical astrocyte or neuronal cultures prior to, and/or during, combined oxygen-glucose deprivation (OGD) injury. Cell death was assessed via lactate dehydrogenase (LHD) and propidium iodide staining 24 h after injury. NSC-derived exosomes afforded marked protection to astrocytes following OGD. A more modest (but significant) level of protection was observed with human iCM-derived exosomes applied to astrocytes, and with NSC-derived exosomes applied to primary neuronal cultures. In subsequent experiments, NSC-derived exosomes were injected intravenously into adult male mice 2 h after transient (1 h) middle cerebral artery occlusion (MCAO). Gross motor function was assessed 1 day after reperfusion and infarct volume was assessed 4 days after reperfusion. Mice treated post-stroke with intravenous NSC-derived exosomes exhibited significantly reduced infarct volumes. Together, these results suggest that exosomes isolated from mouse NSCs provide neuroprotection against experimental stroke possibly via preservation of astrocyte function. Intravenous NSC-derived exosome treatment may therefore provide a novel clinical adjuvant for stroke in the immediate post-injury period.

Serum prealbumin is a recognized marker of malnutrition, but its prognostic role in patients with hemorrhagic stroke remains unclear. In this study, we retrospectively reviewed the records of 105 patients with hemorrhagic stroke admitted to Renmin Hospital of Wuhan University, China, from January to December 2015. We collected demographic and radiological data, and recorded serum prealbumin levels at admission and on days 1, 3, 6, 9, and 14-21. The existence of infections and gastrointestinal hemorrhage, and clinical condition at discharge were also recorded. Serum prealbumin levels during hospitalization were significantly lower in patients with infections compared with those without infections, and also significantly lower in patients with gastrointestinal hemorrhage compared with those without. Serum prealbumin levels at discharge were significantly higher in patients with good recovery than in those with poor recovery. We conclude that regular serum prealbumin measurements in patients with hemorrhagic stroke may be a useful indicator for determining clinical status and prognosis, which may therefore help to guide clinical decision-making.

Recent studies demonstrate significant neuroimmune changes in postpartum females, a period that also carries an increased risk of stroke. Oxytocin, a major hormone upregulated in the brains of nursing mothers, has been shown to both modulate neuroinflammation and protect against stroke. In the present study we assessed whether and how nursing modulates the neuroimmune response and injury after stroke. We observed that postpartum nursing mice were markedly protected from 1 h of transient middle cerebral artery occlusion (MCAO) relative to either non-pregnant/non-postpartum or non-nursing (pups removed) postpartum females. Nursing mice also expressed reduced levels of pro-inflammatory cytokines, had decreased migration of blood leukocytes into the brain following MCAO, and displayed peripheral neuroimmune changes characterized by increased spleen weight and increased fraction of spleen monocytes. Intranasal oxytocin treatment in non-pregnant females in part recapitulated the protective and anti-inflammatory effects associated with nursing. In summary, the results of the present study demonstrate that nursing in the postpartum period provides relative protection against transient ischemic stroke associated with decreased brain leukocytes and increased splenic monocytes. These effects appear to be regulated, at least in part, by oxytocin.

Background: Stroke is a sexually dimorphic disease with age-dependent sex differences in incidence, prevalence, and outcome. Delineating the molecular mechanisms that determine sexual dimorphism in stroke is necessary to overcome translational barriers and advance the development of novel stroke treatments. Non-coding RNAs, including microRNAs ( miRs ), are upstream regulators of genes that regulate cell survival. In young adult male animals, miR-181a and miR-200c have been established as central regulators in the cellular response to stroke, however their role in females or aged animal cohorts represents a critical knowledge gap. Therefore, in the present study we investigated the response of miR-181a and miR-200c in the brain after stroke in aged male and female mice. Methods: Aged (20 month old) male and female mice were subjected to 1h middle cerebral artery occlusion (MCAO) followed by 24h reperfusion. RT-qPCR, fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC) were used to quantify and localize post-MCAO cellular expression of miR-181a and miR-200c. Results: There was no baseline difference in miR-181a between sexes, however miR-200c expression was ~3-fold higher at baseline in female animals versus males. MCAO induced ~2-fold increase in miR-181a in male animals but post-MCAO expression remained unchanged in females. In contrast, miR-200c expression increased by ~16-fold in males and ~4-fold in females. At baseline, miR-181a and miR-200c primarily localized to cortical neurons (NeuN+). In response to MCAO astrocyte reactivity (GFAP+) coincided with robust expression of miR-200c in both males and females. Conclusions: MiR-181a and miR-200c exhibit sexual dimorphism in response to stroke. Augmented expression of miR-200c appears secondary to astrocyte reactivity. Future experiments will determine if inhibition of miR-181a and miR-200c are protective against ischemic stroke in aged animals.

Transient forebrain ischemia, as occurs with cardiac arrest and resuscitation, results in impaired cognitive function secondary to delayed neuronal cell death in hippocampal cornu ammonis-1 (CA1). Comparatively, hippocampal neurons in the adjacent dentate gyrus (DG) survive, suggesting that elucidating the molecular mechanisms underpinning hippocampal sub-regional differences in ischemic tolerance could be central in the development of novel interventions to improve outcome in survivors of forebrain ischemia. MicroRNAs (miRNAs) are non-coding RNAs that modulate the translation of target genes and have been established as an effective therapeutic target for other models of injury. The objective of the present study was to assess and compare post-injury miRNA profiles between CA1 and DG using a rat model of forebrain ischemia. CA1 and DG sub-regions were dissected from rat hippocampi following 10 min of forebrain ischemia at three time points (3 h, 24 h, and 72 h) and at baseline. Pronounced differences between CA1 and DG were observed for several select miRNAs, including miR-181a-5p, a known regulator of cerebral ischemic injury. We complexed fluorescent in situ hybridization with immunohistochemistry to observe cell-type specific and temporal differences in mir-181a-5p expression between CA1 and DG in response to injury. Using established miRNA-mRNA prediction algorithms, we extended our observations in CA1 miRNA dysregulation to identify key functional pathways as potential modulators of CA1 ischemic vulnerability. In summary, our observations support a central role for miRNAs in selective CA1 ischemic vulnerability and suggest that cell-specific miRNA targeting could be a viable clinical approach to preserve CA1 neurons and improve cognitive outcomes for survivors of transient forebrain ischemia.

The underlying mechanisms of isoflurane neurotoxicity in the developing brain remain unclear. Ferroptosis is a recently characterized form of programmed cell death distinct from apoptosis or autophagy, characterized by iron-dependent reactive oxygen species (ROS) generation secondary to failure of glutathione-dependent antioxidant defenses. The results of the present study are the first to demonstrate in vitro that ferroptosis is a central mechanism contributing to isoflurane neurotoxicity. We observed in embryonic mouse primary cortical neuronal cultures (day-in-vitro 7) that 6 h of 2% isoflurane exposure was associated with decreased transcription and protein expression of the lipid repair enzyme glutathione peroxidase 4. In parallel, isoflurane exposure resulted in increased ROS generation, disruption in mitochondrial membrane potential, and cell death. These effects were significantly attenuated by pre-treatment with the selective ferroptosis inhibitor ferrostatin-1 (Fer-1). Collectively, these observations provide a novel mechanism for isoflurane-induced injury in the developing brain and suggest that pre-treatment with Fer-1 may be a potential clinical intervention for neuroprotection.

Mild traumatic brain injury (mTBI) can result in permanent impairment in memory and learning and may be a precursor to other neurological sequelae. Clinical treatments to ameliorate the effects of mTBI are lacking. Inhibition of microRNA-181a (miR-181a) is protective in several models of cerebral injury, but its role in mTBI has not been investigated. In the present study, miR-181a-5p antagomir was injected intracerebroventricularly 24 h prior to closed-skull cortical impact in young adult male mice. Paw withdrawal, open field, zero maze, Y maze, object location and novel object recognition tests were performed to assess neurocognitive dysfunction. Brains were assessed immunohistologically for the neuronal marker NeuN, the perineuronal net marker wisteria floribunda lectin (WFA), cFos, and the interneuron marker parvalbumin. Protein quantification was performed with immunoblots for synaptophysin and postsynaptic density 95 (PSD95). Fluorescent in situ hybridization was utilized to localize hippocampal miR-181a expression. MiR-181a antagomir treatment reduced neuronal miR-181a expression after mTBI, restored deficits in novel object recognition and increased hippocampal parvalbumin expression in the dentate gyrus. These changes were associated with decreased dentate gyrus hyperactivity indicated by a relative reduction in PSD95 and cFos expression. These results suggest that miR-181a inhibition may be a therapeutic approach to reduce hippocampal excitotoxicity and prevent cognitive dysfunction following mTBI.

Astrocytes and microglia play crucial roles in the response to cerebral ischemia and are effective targets for stroke therapy in animal models. MicroRNAs (miRs) are important posttranscriptional regulators of gene expression that function by inhibiting the translation of select target genes. In astrocytes, miR expression patterns regulate mitochondrial function in response to oxidative stressviatargeting of Bcl2 and heat shock protein 70 family members. Mitochondria play an active role in microglial activation, and miRs regulate the microglial neuroinflammatory response. As endogenous miR expression patterns can be altered with exogenous mimics and inhibitors, miR-targeted therapies represent a viable intervention to optimize glial mitochondrial function and improve clinical outcome following cerebral ischemia. In the present article, we review the role that astrocytes and microglia play in neuronal function and fate following ischemic stress, discuss the relevance of mitochondria in the glial response to injury, and present current evidence implicating miRs as critical regulators in the glial mitochondrial response to cerebral ischemia.

Cerebral ischemia remains a major cause of death and disability worldwide, yet therapeutic options remain limited. Differences in sex and age play an important role in the final outcome in response to cerebral ischemia in both experimental and clinical studies: males have a higher risk and worse outcome than females at younger ages and this trend reverses in older ages. Although the molecular mechanisms underlying sex dimorphism are complex and are still not well understood, studies suggest steroid hormones, sex chromosomes, differential cell death and immune pathways, and sex-specific microRNAs may contribute to the outcome following cerebral ischemia. This review focuses on differential effects between males and females on cell death and immunological pathways in response to cerebral ischemia, the central role of innate sex differences in steroid hormone signaling, and upstreamregulation of sexually dimorphic gene expression by microRNAs.

Background and Purpose— MicroRNA (miR)-200c increases rapidly in the brain after transient cerebral ischemia but its role in poststroke brain injury is unclear. Reelin, a regulator of neuronal migration and synaptogenesis, is a predicted target of miR-200c. We hypothesized that miR-200c contributes to injury from transient cerebral ischemia by targeting reelin. Methods— Brain infarct volume, neurological score and levels of miR-200c, reelin mRNA, and reelin protein were assessed in mice subjected to 1 hour of middle cerebral artery occlusion with or without intracerebroventricular infusion of miR-200c antagomir, mimic, or mismatch control. Direct targeting of reelin by miR-200c was assessed in vitro by dual luciferase assay and immunoblot. Results— Pretreatment with miR-200c antagomir decreased post–middle cerebral artery occlusion brain levels of miR-200c, resulting in a significant reduction in infarct volume and neurological deficit. Changes in brain levels of miR-200c inversely correlated with reelin protein expression. Direct targeting of the Reln 3′ untranslated region by miR-200c was verified with dual luciferase assay. Inhibition of miR-200c resulted in an increase in cell survival subsequent to in vitro oxidative injury. This effect was blocked by knockdown of reelin mRNA, whereas application of reelin protein afforded protection. Conclusions— These findings suggest that the poststroke increase in miR-200c contributes to brain cell death by inhibiting reelin expression, and that reducing poststroke miR-200c is a potential target to mitigate stroke-induced brain injury.

Significance: Cerebral ischemia is a major cause of death and disability throughout the world, yet therapeutic options remain limited. The interplay between the cellular redox state and the immune response plays a critical role in determining the extent of neural cell injury after ischemia and reperfusion. Excessive amounts of reactive oxygen species (ROS) generated by mitochondria and other sources act both as triggers and effectors of inflammation. This review will focus on the interplay between these two mechanisms. Recent Advances: MicroRNAs (miRNAs) are important post-transcriptional regulators that interact with multiple target messenger RNAs coordinately regulating target genes, including those involved in controlling mitochondrial function, redox state, and inflammatory pathways. This review will focus on the regulation of mitochondria, ROS, and inflammation by miRNAs in the chain of deleterious intra- and intercellular events that lead to brain cell death after cerebral ischemia. Critical Issues: Although pretreatment using miRNAs was effective in cerebral ischemia in rodents, testing treatment after the onset of ischemia is an essential next step in the development of acute stroke treatment. In addition, miRNA formulation and delivery into the CNS remain a challenge in the clinical translation of miRNA therapy. Future Directions: Future research should focus on post-treatment and potential clinical use of miRNAs. Antioxid. Redox Signal. 22, 187–202.

Ischemic stroke remains a leading cause of death and disability with few treatment options. MicroRNAs (miRs) are short, non-coding RNAs that regulate gene expression. They have important potential applications as biomarkers for stroke severity and outcome, as well as presenting unique possibilities for interventions to minimize injury and improve recovery and outcome following stroke. MiRs function by binding messenger RNAs (mRNA) and silencing translation of target genes. Endogenous miR expression levels change in response to stress, and they can be altered by application of exogenous nucleotides—miR mimics—to increase or inhibitors to decrease levels of specific miRs. By virtue of their relatively short binding sequences, a single miR can simultaneously modulate numerous related gene targets. As miR expression can be cell-type specific, miRs can also be used to target specific brain cell types, such as microglia and astrocytes, which helps determine neuronal cell fate following stress. MiR-based therapeutics may therefore provide a novel approach to the development of effective therapeutics for ischemic stroke.

Whether the effect of miR-181a is sexually dimorphic in stroke is unknown. Prior work showed protection of male mice with miR-181a inhibition. Estrogen receptor-α (ERα) is an identified target of miR181 in endometrium. Therefore we investigated the separate and joint effects of miR-181a inhibition and 17β-estradiol (E2) replacement after ovariectomy. Adult female mice were ovariectomized and implanted with an E2- or vehicle-containing capsule for 14d prior to 1h middle cerebral artery occlusion (MCAO). Each group received either miR-181a antagomir or mismatch control by intracerebroventricular injection 24h before MCAO. After MCAO neurologic deficit and infarct volume were assessed. Primary male and female astrocyte cultures were subjected to glucose deprivation with miR-181a inhibitor or transfection control, and E2 or vehicle control, with/without ESRα knockdown with small interfering RNA. Cell death was assessed by propidium iodide staining, and lactate dehydrogenase assay. A miR-181a/ERα target site blocker (TSB), with/without miR-181a mimic, was used to confirm targeting of ERα by miR-181a in astrocytes. Individually, miR-181a inhibition or E2 decreased infarct volume and improved neurologic score in female mice, and protected male and female astrocyte cultures. Combined miR-181a inhibition plus E2 afforded greater protection of female mice and female astrocyte cultures, but not in male astrocyte cultures. MiR-181a inhibition only increased ERα levels in vivo and in female cultures, while ERα knockdown with siRNA increased cell death in both sexes. Treatment with ERα TSB was strongly protective in both sexes. In conclusion, the results of the present study suggest miR-181a inhibition enhances E2-mediated stroke protection in females in part by augmenting ERα production, a mechanism detected in female mice and female astrocytes. Sex differences were observed with combined miR-181a inhibition/E2 treatment, and miR-181a targeting of ERα.

One reason for the translational failure of antiinflammatory approaches for stroke therapy is that strategies targeting neuronal survival alone may be insufficient to improve outcome. There has been an increased interest in the roles of other cell types in the inflammatory response in the brain following thrombotic stroke. Within minutes of ischemia, local neuroinflammatory events occur mediated by the activation of microglia and astrocytes, specialized glial cells that represent the largest proportion of cells in the mammalian brain. This chapter will discuss the critical role that microglia and astrocytes play in the induction of poststroke neuroinflammation, and their potential as targets in the next generation of therapeutic strategies for thrombotic stroke.

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor in adults. Patients with GBM have poor outcomes, even with the current gold-standard first-line treatment: maximal safe resection combined with radiotherapy and temozolomide chemotherapy. Accumulating evidence suggests that advances in antigen-specific cancer vaccines and immune checkpoint blockade in other advanced tumors may provide an appealing promise for immunotherapy in glioma. The future of therapy for GBM will likely incorporate a combinatorial, personalized approach, including current conventional treatments, active immunotherapeutics, plus agents targeting immunosuppressive checkpoints.

Stroke is one of the leading causes of death and disability worldwide. Because stroke is a multifactorial disease with a short therapeutic window many clinical stroke trials have failed and the only currently approved therapy is thrombolysis. MicroRNAs (miRNA) are endogenously expressed noncoding short single-stranded RNAs that play a role in the regulation of gene expression at the post-transcriptional level, via degradation or translational inhibition of their target mRNAs. The study of miRNAs is rapidly growing and recent studies have revealed a significant role of miRNAs in ischemic disease. miRNAs are especially important candidates for stroke therapeutics because of their ability to simultaneously regulate many target genes and since to date targeting single genes for therapeutic intervention has not yet succeeded in the clinic. Although there are already quite a few review articles about miRNA in ischemic heart disease, much less is currently known about miRNAs in cerebral ischemia. This review summarizes current knowledge about miRNAs and cerebral ischemia, focusing on the role of miRNAs in ischemia, both changes in expression and identification of potential targets, as well as the potential of miRNAs as biomarkers and therapeutic targets in cerebral ischemia.

The interleukin-1 family of cytokines are potent inducers of inflammation and pain. Proteolytic activation of this family of cytokines is under the control of several innate immune receptors that coordinate to form large multiprotein signalling platforms, termed inflammasomes. Recent evidence suggests that a wide range of inflammatory diseases, cancers, and metabolic and autoimmune disorders, in which pain is a common complaint, may be coordinated by inflammasomes. Activation of inflammasomes results in cleavage of caspase-1, which subsequently induces downstream initiation of several potent pro-inflammatory cascades. Therefore, it has been proposed that targeting inflammasome activity may be a novel and effective therapeutic strategy for these pain-related diseases. The purpose of this narrative review article is to provide the reader with an overview of the activation and regulation of inflammasomes and to investigate the potential therapeutic role of inflammasome inhibition in the treatment of diseases characterized by pain, including the following: complex regional pain syndrome, gout, rheumatoid arthritis, inflammatory pain, neuropathic pain, chronic prostatitis, chronic pelvic pain syndrome, and fibromyalgia. We conclude that the role of the inflammasome in pain-associated diseases is likely to be inflammasome subtype and disease specific. The currently available evidence suggests that disease-specific targeting of the assembly and activity of the inflammasome complex may be a novel therapeutic opportunity for the treatment of refractory pain in many settings.

Background The transient receptor potential vanilloid 1 ( TRPV 1) mediates cellular responses to pain, heat, or noxious stimuli by calcium influx; however, the cellular localization and function of TRPV 1 in the cardiomyocyte is largely unknown. We studied whether myocardial injury is regulated by TRPV 1 and whether we could mitigate reperfusion injury by limiting the calcineurin interaction with TRPV 1. Methods and Results In primary cardiomyocytes, confocal and electron microscopy demonstrates that TRPV 1 is localized to the mitochondria. Capsaicin, the specific TRPV 1 agonist, dose‐dependently reduced mitochondrial membrane potential and was blocked by the TRPV 1 antagonist capsazepine or the calcineurin inhibitor cyclosporine. Using in silico analysis, we discovered an interaction site for TRPV 1 with calcineurin. We synthesized a peptide, V1‐cal, to inhibit the interaction between TRPV 1 and calcineurin. In an in vivo rat myocardial infarction model, V1‐cal given just prior to reperfusion substantially mitigated myocardial infarct size compared with vehicle, capsaicin, or cyclosporine (24±3% versus 61±2%, 45±1%, and 49±2%, respectively; n=6 per group; P TRPV 1 knockout rats. Conclusions TRPV 1 is localized at the mitochondria in cardiomyocytes and regulates mitochondrial membrane potential through an interaction with calcineurin. We developed a novel therapeutic, V1‐cal, that substantially reduces reperfusion injury by inhibiting the interaction of calcineurin with TRPV 1. These data suggest that TRPV 1 is an end‐effector of cardioprotection and that modulating the TRPV 1 protein interaction with calcineurin limits reperfusion injury.

Intracellular pH (pHi) was measured in isolated Xenopus laevis single myofibres at the onset of contractions, with and without glycolytic blockade, to investigate the time course of glycolytic activation. Single myofibres (n= 8; CON) were incubated in 2′,7′-bis(carboxyethyl)-5(6)-carboxyfluorescein acetoyxmethyl ester (10 μm; for fluorescence measurement of pHi) and stimulated for 15 s at 0.67 Hz in anoxia in the absence (control condition; CON) and presence of a glycolytic inhibitor (1 mm iodoacetic acid; IAA). Intracellular pHi and tension were continuously recorded, and the differences in pHi between conditions were used to estimate the activation time of glycolysis. An immediate and steady increase in pHi (initial alkalosis) at the onset of contractions was similar between CON and IAA trials for the first 9 s of the contractile bout. However, from six contractions (∼10 s) throughout the remainder of the bout, IAA demonstrated a continued rise in pHi, in contrast to a progressive decrease in pHi in CON (P < 0.05). These results demonstrate, with high temporal resolution, that glycolysis is activated within six contractions (10 s at 0.67 Hz) in single Xenopus skeletal muscle fibres.

Cellular heterogeneity is a fundamental characteristic of many cancers. A lack of cellular homogeneity contributes to difficulty in designing targeted oncological therapies. Therefore, the development of novel methods to determine and characterize oncologic cellular heterogeneity is a critical next step in the development of novel cancer therapies. Single-cell sequencing (SCS) technology has been recently employed for analyzing the genetic polymorphisms of individual cells at the genome-wide level. SCS requires (1) precise isolation of the single cell of interest; (2) isolation and amplification of genetic material; and (3) descriptive analysis of genomic, transcriptomic, and epigenomic data. In addition to targeted analysis of single cells isolated from tumor biopsies, SCS technology may be applied to circulating tumor cells, which may aid in predicting tumor progression and metastasis. In this paper, we provide an overview of SCS technology and review the current literature on the potential application of SCS to clinical oncology and research.

Background: Isoflurane induces cell death in neurons undergoing synaptogenesis via increased production of pro-brain–derived neurotrophic factor (proBDNF) and activation of postsynaptic p75 neurotrophin receptor (p75NTR). Astrocytes express p75NTR, but their role in neuronal p75NTR-mediated cell death remains unclear. The authors investigated whether astrocytes have the capacity to buffer increases in proBDNF and protect against isoflurane/p75NTR neurotoxicity. Methods: Cell death was assessed in day in vitro (DIV) 7 mouse primary neuronal cultures alone or in co-culture with age-matched or DIV 21 astrocytes with propidium iodide 24 h after 1 h exposure to 2% isoflurane or recombinant proBDNF. Astrocyte-targeted knockdown of p75NTR in co-culture was achieved with small-interfering RNA and astrocyte-specific transfection reagent and verified with immunofluorescence microscopy. proBDNF levels were assessed by enzyme-linked immunosorbent assay. Each experiment used six to eight replicate cultures/condition and was repeated at least three times. Results: Exposure to isoflurane significantly (P < 0.05) increased neuronal cell death in primary neuronal cultures (1.5 ± 0.7 fold, mean ± SD) but not in co-culture with DIV 7 (1.0 ± 0.5 fold) or DIV 21 astrocytes (1.2 ± 1.2 fold). Exogenous proBDNF dose dependently induced neuronal cell death in both primary neuronal and co-cultures, an effect enhanced by astrocyte p75NTR inhibition. Astrocyte-targeted p75NTR knockdown in co-cultures increased media proBDNF (1.2 ± 0.1 fold) and augmented isoflurane-induced neuronal cell death (3.8 ± 3.1 fold). Conclusions: The presence of astrocytes provides protection to growing neurons by buffering increased levels of proBDNF induced by isoflurane. These findings may hold clinical significance for the neonatal and injured brain where increased levels of proBDNF impair neurogenesis.

Anti-NMDAR encephalitis is a recently identified autoimmune disease, described by an immune-mediated loss of NMDA glutamate receptors, resulting in progressive mental deterioration. To date, literature on anti-NMDAR encephalitis has been largely clinically oriented, including descriptions of the clinical presentation and course, diagnostic methods, and potential clinical treatments. However, the underlying molecular mechanisms contributing to the complex immunological cellular transformation that is associated with the progression of anti-NMDAR encephalitis remain to be adequately explored. This review will provide a summary of the current literature on anti-NMDAR encephalitis, including the immunologic molecular mechanisms contributing to disease progression. In particular this review will focus on the effect of anti-NMDAR on GluN2-NMDAR expression and the molecular transformation of B and T leukocytes in the loss of self-tolerance. Further research on the immunologic mechanisms contributing to anti-NMDAR encephalitis may provide an avenue for future novel diagnostic approaches, such as immunologic surveillance, as well as new therapeutic strategies for this recently identified autoimmune disease.

miR-181 has deleterious effects on stroke outcome, and reducing miR-181a levels prior to middle cerebral artery occlusion (MCAO) was shown previously to be protective. Here we tested the effect of post-ischemic treatment with miR-181a antagomir by intracerebroventricular and intravenous routes of administration on infarct size, neurological outcome, inflammatory response and long term behavioral outcome. Post-treatment with miR-181a antagomir significantly reduced infarction size, improved neurological deficits and reduced NF-κB activation, numbers of infiltrating leukocytes and levels of Iba1. Targets affected by miR-181a antagomir administered after stroke onset include BCL2 and X-linked inhibitor of apoptosis protein (XIAP). Post-treatment with miR-181a antagomir significantly improved behavioral outcome assessed by rotarod at one month. These findings indicate that post-treatment with miR-181a antagomir has neuroprotective effects against ischemic neuronal damage and neurological impairment in mice, and the protection is long lasting including recovery of motor function and coordination over one month. The ability to protect the brain with post-treatment with miR-181a antagomir with long lasting effect makes this a promising therapeutic target and may be an innovative and effective new approach for stroke therapy.

We tested the hypothesis that contracting skeletal muscle can rapidly restore force development during reperfusion after brief total ischemia and that this rapid recovery depends on O2 availability and not an alternate factor related to blood flow. Isolated canine gastrocnemius muscle ( n = 5) was stimulated to contract tetanically (isometric contraction elicited by 8 V, 0.2-ms duration, 200-ms trains, at 50-Hz stimulation) every 2 s until steady-state conditions of muscle blood flow (controlled by pump perfusion) and developed force were attained (3 min). While maintaining the same stimulation pattern, muscle blood flow was then reduced to zero (complete ischemia) for 2 min. Normal blood flow was then restored to the contracting muscle; however, two distinct conditions of oxygenation (at the same blood flow) were sequentially imposed: deoxygenated blood (30 s), blood with normal arterial O2content (30 s), a return to deoxygenated blood (30 s), and finally a return to normal arterial O2 content (90 s). During the ischemic period, force development fell to 39 ± 6 (SE)% of normal (from 460 ± 40 to 170 ± 20 N/100 g). When muscle blood flow was restored to normal by perfusion with deoxygenated blood, developed force continued to decline to 140 ± 20 N/100 g. Muscle force rapidly recovered to 310 ± 30 N/100 g ( P < 0.05) during the 30 s in which the contracting muscle was perfused with oxygenated blood and then fell again to 180 ± 30 N/100 g when perfused with blood with low[Formula: see text]. These findings demonstrate that contracting skeletal muscle has the capacity for rapid recovery of force development during reperfusion after a short period of complete ischemia and that this recovery depends on O2availability and not an alternate factor related to blood flow restoration.

Acute cerebral ischemia can occur secondary to embolism, cardiac arrest, hemorrhage, traumatic brain injury, edema, vascular compression, or any physiologic condition resulting in low cardiac output state. Survivors of cerebral ischemic events frequently suffer from profound disability, accounting for > $70 billion in 2010 for treatment of embolic stroke in the US alone. More strikingly, the cost to treat stroke in the US is anticipated to soar to > $180 billion by 2030, according to estimates from the American Heart Association (Ovbiagele et al., 2013). Despite hundreds of promising pre-clinical studies in animal models, effective clinical treatments for the most common forms of cerebral ischemia remain limited: standard treatment for embolic stroke is restricted to thrombolytic therapy or clot retrieval during a narrow therapeutic window, while post-resuscitation treatment following cardiac arrest remains the (controversial) application of mild hypothermia. The massive failure to translate experimental findings to the development of any successful clinical intervention suggests that redirecting investigational resources to developing new therapies to improve long-term recovery in survivors of stroke may be a logical and necessary next step.

The purpose of this study was to examine the bioenergetics and regulation of O2uptake (V˙o2) and force production in contracting muscle when blood flow was moderately reduced during a steady-state contractile period. Canine gastrocnemius muscle ( n = 5) was isolated, and 3-min stimulation periods of isometric, tetanic contractions were elicited sequentially at rates of 0.25, 0.33, and 0.5 contractions/s (Hz) immediately followed by a reduction of blood flow [ischemic (I) condition] to 46 ± 3% of the value obtained at 0.5 Hz with normal blood flow. TheV˙o2of the contracting muscle was significantly ( P < 0.05) reduced during the I condition [6.5 ± 0.8 (SE) ml ⋅ 100 g−1⋅ min−1] compared with the same stimulation frequency with normal flow (11.2 ± 1.5 ml ⋅ 100 g−1⋅ min−1), as was the tension-time index (79 ± 12 vs. 123 ± 22 N ⋅ g−1⋅ min−1, respectively). The ratio ofV˙o2to tension-time index remained constant throughout all contraction periods. Muscle phosphocreatine concentration, ATP concentration, and lactate efflux were not significantly different during the I condition compared with the 0.5-Hz condition with normal blood flow. However, at comparable rates of V˙o2and tension-time index, muscle phosphocreatine concentration and ATP concentration were significantly less during the I condition compared with normal-flow conditions. These results demonstrate that, in this highly oxidative muscle, the normal balance of O2supply to force output was maintained during moderate ischemia by downregulation of force production. In addition, 1) the minimal disruption in intracellular homeostasis after the initiation of ischemia was likely a result of steady-state metabolic conditions having already been activated, and 2) the difference in intracellular conditions at comparable rates ofV˙o2and tension-time index between the normal flow and I condition may have been due to altered intracellular O2tension.

This case describes the loss of airway patency in a pediatric trauma patient and the clinical concerns relevant to successful resuscitation using jet ventilation through a Cookgas airway exchanger.

Hemoperitoneum may occur in various emergent conditions. In the trauma setting, evidence of intraperitoneal blood depicted at computed tomography (CT) should lead the radiologist to conduct a careful search of images for the injured visceral organ (the liver or spleen). Specific CT signs, such as a sentinel clot or extravasation of intravascular contrast material, may indicate the source of bleeding and help direct management. In addition, the configuration of accumulated blood may help identify the injured organ; for example, triangular fluid collections are observed in the mesentery most often in the setting of bowel or mesenteric injury. Less commonly, hemoperitoneum may have a nontraumatic origin. Iatrogenic hemoperitoneum may occur as a complication of surgery or other interventional procedures in the abdominal cavity or as a result of anticoagulation therapy. Hemoperitoneum also may be seen in the setting of blood dyscrasias such as hemophilia and polycythemia vera. Tumor-associated hemorrhage, which most often occurs in hepatocellular carcinoma, hepatic adenoma, or vascular metastatic disease, also may produce hemoperitoneum. Other potential causes of nontraumatic hemoperitoneum are gynecologic conditions such as hemorrhage or rupture of an ovarian cyst and rupture of the gestational sac in ectopic pregnancy, and hepatic hematoma in syndromic hemolysis with elevated liver enzymes and low platelet count (HELLP syndrome). Vascular lesions (visceral artery aneurysms and pseudoaneurysms) that occur in systemic vascular diseases such as Ehlers-Danlos syndrome or in pancreatitis are another less common source of hemoperitoneum.

During the past decade, unenhanced computed tomography (CT) has become the standard of reference in the detection of urinary calculi owing to its high sensitivity (>95%) and specificity (>98%) in this setting. Numerous diseases may manifest as acute flank pain and mimic urolithiasis. Up to one-third of unenhanced CT examinations performed because of flank pain may reveal unsuspected findings unrelated to stone disease, many of which can help explain the patient's condition. Alternative diagnoses are most commonly related to gynecologic conditions (especially adnexal masses) and nonstone genitourinary disease (eg, pyelonephritis, renal neoplasm), closely followed by gastrointestinal disease (especially appendicitis and diverticulitis). Hepatobiliary, vascular, and musculoskeletal conditions may also be encountered. Vascular causes of acute flank pain must always be considered, since these constitute life-threatening emergencies that may require the intravenous administration of contrast material for diagnosis. Radiologists must be familiar with the typical findings of urinary stone disease at unenhanced CT, as well as the spectrum of alternative diagnoses that may be detected with this modality, to accurately diagnose the source of flank pain.

Reperfusion following prolonged ischemia induces cellular damage in whole skeletal muscle models. Ischemic preconditioning attenuates the deleterious effects. We tested whether individual skeletal muscle fibers would be similarly affected by severe hypoxia and reoxygenation (H/R) in the absence of extracellular factors and whether cellular damage could be alleviated by hypoxic preconditioning. Force and free cytosolic Ca2+([Ca2+]c) were monitored in Xenopus single muscle fibers ( n = 24) contracting tetanically at 0.2 Hz during 5 min of severe hypoxia and 5 min of reoxygenation. Twelve cells were preconditioned by a shorter bout of H/R 1 h before the experimental trial. In preconditioned cells, force relative to initial maximal values (P/Po) and relative peak [Ca2+]cfell ( P< 0.05) during 5 min of hypoxia and recovered during reoxygenation. In contrast, P/Poand relative peak [Ca2+]cfell more during hypoxia ( P < 0.05) and recovered less during reoxygenation ( P < 0.05) in control cells. The ratio of force to [Ca2+]cwas significantly higher in the preconditioned cells during severe hypoxia, suggesting that changes in [Ca2+]cwere not solely responsible for the loss in force. We conclude that 1) isolated skeletal muscle fibers contracting in the absence of extracellular factors are susceptible to H/R injury associated with changes in Ca2+handling; and 2) hypoxic preconditioning improves contractility, Ca2+handling, and cell recovery during subsequent hypoxic insult.