Inhibitors of cell cycle checkpoints and DNA replication cause different responses in normal versus malignant urothelial cells

S-phase checkpoints are triggered in tumor cells in response to DNA replication stress caused by the tumor microenvironment or oncogenes. A recent report from our laboratory showed that tumor cells and more normal epithelial cells have a very different response to replication stress. In this Author's View, the implications of this finding are discussed

Hamster leukemia virus: lack of endogenous DNA synthesis and unique structure of its DNA polymerase

Infectious hamster leukemia virus (HaLV) contains a DNA polymerase different from those of murine and avian viruses. No endogenous reaction directed by the 60 to 70S RNA of HaLV could be demonstrated in detergenttreated HaLV virions, nor could the purified DNA polymerase copy added viral RNA. The virion RNA could, however, act as template for added avian myeloblastosis virus DNA polymerase and the HaLV DNA polymerase could efficiently utilize homopolymers as templates. The HaLV enzyme was like other reverse transcriptases in that certain ribohomopolymers were much better templates than the homologous deoxyribohomopolymers. No ribonuclease H activity could be shown in the HaLV enzyme, but neither could activity be found in the murine leukemia virus DNA polymerase. The hamster enzyme was unique in that poly(A) ·oligo(dT) was a poor template, and globin mRNA primed with oligo(dT) was totally inactive as a template. Its uniqueness was also indicated by its subunit composition; electrophoresis of the HaLV DNA polymerase in sodium dodecyl sulfate-containing polyacrylamide gels revealed equimolar amounts of two polypeptides of molecular weight 68,000 and 53,000. The sedimentation rate of the enzyme in glycerol gradients was consistent with a structure containing one each of the two polypeptides. The enzyme thus appears to be structurally distinct from other known virion DNA polymerases. Its inability to carry out an endogenous reaction in vitro might result from an inability to utilize certain primers

Immunomodulatory Effect of Toll-Like Receptor-3 Ligand Poly I:C on Cortical Spreading Depression

The release of inflammatory mediators following cortical spreading depression (CSD) is suggested to play a role in pathophysiology of CSD-related neurological disorders. Toll-like receptors (TLR) are master regulators of innate immune function and involved in the activation of inflammatory responses in the brain. TLR3 agonist poly I:C exerts anti-inflammatory effect and prevents cell injury in the brain. The aim of the present study was to examine the effect of systemic administration of poly I:C on the release of cytokines (TNF-α, IFN-γ, IL-4, TGF-β1, and GM-CSF) in the brain and spleen, splenic lymphocyte proliferation, expression of GAD65, GABAAα, GABAAβ as well as Hsp70, and production of dark neurons after induction of repetitive CSD in juvenile rats. Poly I:C significantly attenuated CSD-induced production of TNF-α and IFN-γ in the brain as well as TNF-α and IL-4 in the spleen. Poly I:C did not affect enhancement of splenic lymphocyte proliferation after CSD. Administration of poly I:C increased expression of GABAAα, GABAAβ as well as Hsp70 and decreased expression of GAD65 in the entorhinal cortex compared to CSD-treated tissues. In addition, poly I:C significantly prevented production of CSD-induced dark neurons. The data indicate neuroprotective and anti-inflammatory effects of TLR3 activation on CSD-induced neuroinflammation. Targeting TLR3 may provide a novel strategy for developing new treatments for CSD-related neurological disorders. © 2014, Springer Science+Business Media New York

Immunomodulatory Effect of Toll-Like Receptor-3 Ligand Poly I:C on Cortical Spreading Depression

The release of inflammatory mediators following cortical spreading depression (CSD) is suggested to play a role in pathophysiology of CSD-related neurological disorders. Toll-like receptors (TLR) are master regulators of innate immune function and involved in the activation of inflammatory responses in the brain. TLR3 agonist poly I:C exerts anti-inflammatory effect and prevents cell injury in the brain. The aim of the present study was to examine the effect of systemic administration of poly I:C on the release of cytokines (TNF-α, IFN-γ, IL-4, TGF-β1, and GM-CSF) in the brain and spleen, splenic lymphocyte proliferation, expression of GAD65, GABAAα, GABAAβ as well as Hsp70, and production of dark neurons after induction of repetitive CSD in juvenile rats. Poly I:C significantly attenuated CSD-induced production of TNF-α and IFN-γ in the brain as well as TNF-α and IL-4 in the spleen. Poly I:C did not affect enhancement of splenic lymphocyte proliferation after CSD. Administration of poly I:C increased expression of GABAAα, GABAAβ as well as Hsp70 and decreased expression of GAD65 in the entorhinal cortex compared to CSD-treated tissues. In addition, poly I:C significantly prevented production of CSD-induced dark neurons. The data indicate neuroprotective and anti-inflammatory effects of TLR3 activation on CSD-induced neuroinflammation. Targeting TLR3 may provide a novel strategy for developing new treatments for CSD-related neurological disorders. © 2014, Springer Science+Business Media New York

Intra-arterial application of nimodipine in reversible cerebral vasoconstriction syndrome: a neuroradiological method to help differentiate from primary central nervous system vasculitis

BACKGROUND: Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by a prolonged, but self-limiting segmental cerebral vasoconstriction. Neurological outcomes vary, but can be severe. The clinical hallmark of RCVS is thunderclap headache, which might come along with further neurological symptoms. Distinguishing RCVS from other entities, such as primary angiitis of the central nervous system (PACNS), is of utmost importance for appropriate therapy. The angiographic response to intra-arterial nimodipine application has been suggested as an additional diagnostic criterion for RCVS but confirmatory studies are limited. We aimed to evaluate the angiographic nimodipine test. METHODS: We reviewed retrospectively the clinical and imaging data of 13 RCVS patients, who were admitted to a single German neurological department between January 2013 and December 2020. RESULTS: Out of 13 patients diagnosed with RCVS, 4 patients underwent an angiographic nimodipine test. In all 4 patients cerebral vasoconstriction completely resolved during nimodipine application. Among the four patients with a positive test, there was one individual, in whom a response was detected after a delay of 60 min. In all patients, we found a complete resolution of cerebral vasoconstriction within 12 weeks. CONCLUSION: Our findings support the usefulness of the application of nimodipine in diagnosing RCVS. Prolonged angiographic observation of the vascular response after nimodipine injection is important

Variations in multiple sclerosis practice within Europe - Is it time for a new treatment guideline?

In the past 5 years, the combination of developments in diagnostic strategy and approval of new disease-modifying therapies has provided an opportunity to achieve dramatic improvements in patient outcomes in multiple sclerosis (MS). However, across Europe there are several factors that may prevent patients from receiving the best therapy at the appropriate time, and there is variation among countries in terms of which of these factors are most relevant. Here, we review current MS clinical practices in a number of countries in the European Union to identify differences regarding initiation of treatment in patients with clinically isolated syndrome or relapsing-remitting MS, and differences in the timing of treatment switch or escalation. While recognizing that policy is not static in any country, we believe that patients' interests would be better served if a European treatment guideline was developed. Such a guideline could both inform and be informed by national policies, facilitating the dissemination of best clinical practice internationally.info:eu-repo/semantics/publishedVersio

Post-stroke inhibition of induced NADPH oxidase type 4 prevents oxidative stress and neurodegeneration

Ischemic stroke is the second leading cause of death worldwide. Only one moderately effective therapy exists, albeit with contraindications that exclude 90% of the patients. This medical need contrasts with a high failure rate of more than 1,000 pre-clinical drug candidates for stroke therapies. Thus, there is a need for translatable mechanisms of neuroprotection and more rigid thresholds of relevance in pre-clinical stroke models. One such candidate mechanism is oxidative stress. However, antioxidant approaches have failed in clinical trials, and the significant sources of oxidative stress in stroke are unknown. We here identify NADPH oxidase type 4 (NOX4) as a major source of oxidative stress and an effective therapeutic target in acute stroke. Upon ischemia, NOX4 was induced in human and mouse brain. Mice deficient in NOX4 (Nox4(-/-)) of either sex, but not those deficient for NOX1 or NOX2, were largely protected from oxidative stress, blood-brain-barrier leakage, and neuronal apoptosis, after both transient and permanent cerebral ischemia. This effect was independent of age, as elderly mice were equally protected. Restoration of oxidative stress reversed the stroke-protective phenotype in Nox4(-/-) mice. Application of the only validated low-molecular-weight pharmacological NADPH oxidase inhibitor, VAS2870, several hours after ischemia was as protective as deleting NOX4. The extent of neuroprotection was exceptional, resulting in significantly improved long-term neurological functions and reduced mortality. NOX4 therefore represents a major source of oxidative stress and novel class of drug target for stroke therapy