Role of neuronal nitric oxide in the regulation of vasopressin expression and release in response to inhibition of cathecholamine synthesis and dehydration

We used neuronal nitric oxide synthase (nNOS) gene knockout mice to study the effects of catecholamines and neuronal nitric oxide on vasopressin expression in the hypothalamic neurosecretory centers. nNOS gene deletion did not change the level of vasopressin mRNA in the supraoptic or paraventricular nuclei. In contrast, vasopressin immunoreactivity was lower in nNOS deficient mice than in wild-type animals. Dehydration increased vasopressin mRNA levels and decreased vasopressin immunoreactivity in both wild-type and nNOS knockout mice, but these responses were more marked in the nNOS knockout mice. Treatment with α-mpt, a pharmacologic inhibitor of catecholamine synthesis, resulted in increased vasopressin mRNA levels in wild-type mice and in reduced vasopressin immunoreactivity in both wild-type and nNOS knockout mice. From these results, we conclude: (1) neuronal nitric oxide suppresses vasopressin expression under basal conditions and during activation of the vasopressin-ergic system by dehydration; (2) catecholamines limit vasopressin expression; (3) nNOS is required for the effects of catecholamines on vasopressin expression. Originally published Neuroscience Letters, Vol. 426, No. 3, Oct 200

Dynamics of myelin content decrease in the rat stroke model

The majority of studies were usually focused on neuronal death after brain ischemia; however, stroke affects all cell types including oligodendrocytes that form myelin sheath in the CNS. Our study is focused on the changes of myelin content in the ischemic core and neighbor structures in early terms (1, 3 and 10 days) after stroke. Stroke was modeled with middle cerebral artery occlusion (MCAo) in 15 male rats that were divided into three groups by time points after operation. Brain sections were histologically stained with Luxol Fast Blue (LFB) for myelin quantification. The significant demyelination was found in the ischemic core, corpus callosum, anterior commissure, whereas myelin content was increased in caudoputamen, internal capsule and piriform cortex compared with the contralateral hemisphere. The motor cortex showed a significant increase of myelin content on the 1st day and a significant decrease on the 3rd and 10th days after MCAo. These results suggest that stroke influences myelination not only in the ischemic core but also in distant structures

The phosphorylation state of eNOS modulates vascular reactivity and outcome of cerebral ischemia in vivo

NO plays critical roles in vascular function. We show that modulation of the eNOS serine 1179 (S1179) phosphorylation site affects vascular reactivity and determines stroke size in vivo. Transgenic mice expressing only a phosphomimetic (S1179D) form of eNOS show greater vascular reactivity, develop less severe strokes, and have improved cerebral blood flow in a middle cerebral artery occlusion model than mice expressing an unphosphorylatable (S1179A) form. These results provide a molecular mechanism by which multiple diverse cardiovascular risks, such as diabetes and obesity, may be centrally integrated by eNOS phosphorylation in vivo to influence blood flow and cardiovascular disease. They also demonstrate the in vivo relevance of posttranslational modification of eNOS in vascular function

c-Jun N-Terminal Kinases (JNKs) in Myocardial and Cerebral Ischemia/Reperfusion Injury

In this article, we review the literature regarding the role of c-Jun N-terminal kinases(JNKs) in cerebral and myocardial ischemia/reperfusion injury. Numerous studiesdemonstrate that JNK-mediated signaling pathways play an essential role in cerebraland myocardial ischemia/reperfusion injury. JNK-associated mechanisms are involved inpreconditioning and post-conditioning of the heart and the brain. The literature and ourown studies suggest that JNK inhibitors may exert cardioprotective and neuroprotectiveproperties. The effects of modulating the JNK-depending pathways in the brain andthe heart are reviewed. Cardioprotective and neuroprotective mechanisms of JNKinhibitors are discussed in detail including synthetic small molecule inhibitors (AS601245,SP600125, IQ-1S, and SR-3306), ion channel inhibitor GsMTx4, JNK-interactingproteins, inhibitors of mixed-lineage kinase (MLK) and MLK-interacting proteins, inhibitorsof glutamate receptors, nitric oxide (NO) donors, and anesthetics. The role of JNKs inischemia/reperfusion injury of the heart in diabetes mellitus is discussed in the contextof comorbidities. According to reviewed literature, JNKs represent promising therapeutictargets for protection of the brain and the heart against ischemic stroke and myocardialinfarction, respectively. However, different members of the JNK family exert diversephysiological properties which may not allow for systemic administration of non-specificJNK inhibitors for therapeutic purposes. Currently available candidate JNK inhibitors withhigh therapeutic potential are identified. The further search for selective JNK3 inhibitorsremains an important task

C-Reactive Protein Causes Insulin Resistance in Mice Through Fcγ Receptor IIB–Mediated Inhibition of Skeletal Muscle Glucose Delivery

Elevations in C-reactive protein (CRP) are associated with an increased risk of insulin resistance. Whether CRP plays a causal role is unknown. Here we show that CRP transgenic mice and wild-type mice administered recombinant CRP are insulin resistant. Mice lacking the inhibitory Fcγ receptor IIB (FcγRIIB) are protected from CRP-induced insulin resistance, and immunohistochemistry reveals that FcγRIIB is expressed in skeletal muscle microvascular endothelium and is absent in skeletal muscle myocytes, adipocytes, and hepatocytes. The primary mechanism in glucose homeostasis disrupted by CRP is skeletal muscle glucose delivery, and CRP attenuates insulin-induced skeletal muscle blood flow. CRP does not impair skeletal muscle glucose delivery in FcγRIIB−/− mice or in endothelial nitric oxide synthase knock-in mice with phosphomimetic modification of Ser1176, which is normally phosphorylated by insulin signaling to stimulate nitric oxide–mediated skeletal muscle blood flow and glucose delivery and is dephosphorylated by CRP/FcγRIIB. Thus, CRP causes insulin resistance in mice through FcγRIIB-mediated inhibition of skeletal muscle glucose delivery

c-Jun N-terminal kinases (JNKs) in myocardial and cerebral ischemia/reperfusion injury

© 2018 Shvedova, Anfinogenova, Atochina-Vasserman, Schepetkin and Atochin. In this article, we review the literature regarding the role of c-Jun N-terminal kinases (JNKs) in cerebral and myocardial ischemia/reperfusion injury. Numerous studies demonstrate that JNK-mediated signaling pathways play an essential role in cerebral and myocardial ischemia/reperfusion injury. JNK-associated mechanisms are involved in preconditioning and post-conditioning of the heart and the brain. The literature and our own studies suggest that JNK inhibitors may exert cardioprotective and neuroprotective properties. The effects of modulating the JNK-depending pathways in the brain and the heart are reviewed. Cardioprotective and neuroprotective mechanisms of JNK inhibitors are discussed in detail including synthetic small molecule inhibitors (AS601245, SP600125, IQ-1S, and SR-3306), ion channel inhibitor GsMTx4, JNK-interacting proteins, inhibitors of mixed-lineage kinase (MLK) and MLK-interacting proteins, inhibitors of glutamate receptors, nitric oxide (NO) donors, and anesthetics. The role of JNKs in ischemia/reperfusion injury of the heart in diabetes mellitus is discussed in the context of comorbidities. According to reviewed literature, JNKs represent promising therapeutic targets for protection of the brain and the heart against ischemic stroke and myocardial infarction, respectively. However, different members of the JNK family exert diverse physiological properties which may not allow for systemic administration of non-specific JNK inhibitors for therapeutic purposes. Currently available candidate JNK inhibitors with high therapeutic potential are identified. The further search for selective JNK3 inhibitors remains an important task

Quantitative detection of circulating tumor DNA by droplet-based digital PCR.

Droplet-based digital PCR is used to detect and quantify the seven most frequent KRAS mutations in circulating tumor DNA of patients with advanced colorectal cancer.- The droplet-based digital PCR method is versatile and two modes of analysis are demonstrated: o Duplex analysis enables sensitive detection of wild-type DNA plus one KRAS or BRAF mutation. o Multiplex analysis enables simultaneous detection of wild-type DNA plus 3 or 4 KRAS mutations.- Detection of rare sequences is highly sensitive compared to the same Taqman assay in bulk (10 % LLOD bulk vs 0.0005 % LLOD droplets).- Biomarkers detection is quantitative: the fraction of mutated DNA in patient samples ranges from 0.1 % to 42%.- Results from circulating tumor DNA analysis match the tumor DNA characterization in most cases, and discordant results reveal need for further studies. Copy and paste your text content here, adjusting the font size to fit Background Circulating tumor DNA (ctDNA) is present in plasma of individuals with advanced cancers. 1 ctDNA is a prognostic marker for patients with colorectal cancer (CRC) and it might also be used for predicting the response to targeted therapy. For example, mutations in KRAS indicate which patients will fail to respond to specific therapies (cetuximab, panitunimab). 2 Although ctDNA is characterized by the presence of a somatic mutation, direct quantitative detection through a simple workflow of such mutant DNA is not feasible by current technologies because the ratio of ctDNA to wildtype DNA can be as low as 1/10,000. This study describes the use of droplet-based digital PCR for detection and quantitation of one of the seven most frequent KRAS mutations in ctDNA from plasm

Anti-Inflammatory Effect of Targeted Delivery of SOD to Endothelium: Mechanism, Synergism with NO Donors and Protective Effects In Vitro and In Vivo

Pro-inflammatory activation of vascular endothelium is implicated in pathogenesis of severe conditions including stroke, infarction and sepsis. We have recently reported that superoxide dismutase (SOD) conjugated with antibodies (Ab/SOD) that provide targeted delivery into endothelial endosomes mitigates inflammatory endothelial activation by cytokines and agonists of Toll-like receptors (TLR). The goal of this study was to appraise potential utility and define the mechanism of this effect. Ab/SOD, but not non-targeted SOD injected in mice alleviated endotoxin-induced leukocyte adhesion in the cerebral vasculature and protected brain from ischemia-reperfusion injury. Transfection of endothelial cells with SOD, but not catalase inhibited NFκB signaling and expression of Vascular Cell Adhesion Molecule-1 induced by both cytokines and TLR agonists. These results affirmed that Ab/SOD-quenched superoxide anion produced by endothelial cells in response to proinflammatory agents mediates NFκB activation. Furthermore, Ab/SOD potentiates anti-inflammatory effect of NO donors in endothelial cells in vitro, as well as in the endotoxin-challenged mice. These results demonstrate the central role of intracellular superoxide as a mediator of pro-inflammatory activation of endothelium and support the notion of utility of targeted interception of this signaling pathway for management of acute vascular inflammation

Cell-Based Drug Delivery and Use of Nano-and Microcarriers for Cell Functionalization

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Cell functionalization with recently developed various nano- and microcarriers for therapeutics has significantly expanded the application of cell therapy and targeted drug delivery for the effective treatment of a number of diseases. The aim of this progress report is to review the most recent advances in cell-based drug vehicles designed as biological transporter platforms for the targeted delivery of different drugs. For the design of cell-based drug vehicles, different pathways of cell functionalization, such as covalent and noncovalent surface modifications, internalization of carriers are considered in greater detail together with approaches for cell visualization in vivo. In addition, several animal models for the study of cell-assisted drug delivery are discussed. Finally, possible future developments and applications of cell-assisted drug vehicles toward targeted transport of drugs to a designated location with no or minimal immune response and toxicity are addressed in light of new pathways in the field of nanomedicine