The phosphodiesterase-4 inhibitor rolipram protects from ischemic stroke in mice by reducing blood–brain-barrier damage, inflammation and thrombosis
Introduction
Ischemic stroke shows a complex pathophysiology that involves a plethora of distinct molecular and cellular pathways. Only recently the importance of inflammatory mechanisms in stroke has been recognized (Iadecola and Anrather, 2011, Magnus et al., 2012). Activation of cerebral endothelial cells represents one of the earliest events within the detrimental cascade of an ischemic insult causing upregulation of specialized cell adhesion receptors. Subsequently, blood-born inflammatory cells (e.g. neutrophils, macrophages) adhere to these receptors and invade the brain parenchyma across the blood–brain-barrier (BBB) in a coordinated and timed fashion. Those cells together with resident brain cells (e.g. microglia, endothelial cells) then secrete a potpourri of highly active soluble mediators like cytokines and chemokines that amplify the inflammatory response by attracting further immune cells or by causing direct tissue damage and neuronal apoptosis (Albert-Weißenberger et al., 2013). If the ischemic trigger persists, the structural components forming the BBB such as tight-junction proteins become disintegrated causing BBB leakage and finally, formation of vascular edema (Ayata and Ropper, 2002, Weiss et al., 2009). Brain edema is an important problem in the care of stroke patients as it can harm otherwise healthy brain areas by compression thereby inducing secondary functional deterioration and mortality. Until now, effective pharmacological strategies to counteract BBB damage and successive inflammation and edema formation in acute ischemic stroke are not available (Bardutzky and Schwab, 2007).
Progressive thrombus formation in the cerebral microvasculature is another important mechanism that mediates secondary infarct growth (Kraft et al., 2012). We could recently show that blocking of fibrin formation or platelet activation reliably protects from ischemic neurodegeneration in rodents (Hagedorn et al., 2010, Kleinschnitz et al., 2006, Kleinschnitz et al., 2007). Most notably, there is accumulating evidence of a subtle interplay between thrombosis and inflammation during the course of an ischemic insult, and this “thrombo-inflammation” might be suitable as novel therapeutic target (Nieswandt et al., 2011).
Rolipram is a selective phosphodiesterase-4 (PDE4) inhibitor that increases intracellular cyclic adenosine monophosphate (cAMP) levels in many cell types and tissues including the brain (Dyke and Montana, 2002). Initially developed as an antidepressant, rolipram also exerts substantial antiinflammatory and barrier stabilizing effects in the central nervous system (CNS) (Zhu et al., 2001). Treatment of rodents with rolipram for example protected from experimental autoimmune encephalomyelitis (EAE) by reducing BBB disruption and tumor necrosis factor α (Tnfα) and interferon γ (Ifnγ) production from autoreactive T cells (Folcik et al., 1999, Sommer et al., 1995). Beneficial effects of rolipram have also been described after experimental traumatic brain injury or spinal cord injury in rodents (Atkins et al., 2007, Beaumont et al., 2009, Costa et al., 2013, Kajana et al., 2009, Nikulina et al., 2004, Pearse et al., 2004, Whitaker et al., 2008) although few reports postulated detrimental or neutral effects of rolipram under these disease conditions (Atkins et al., 2012, Atkins et al., 2013, Wang et al., 2006). In models of global cerebral ischemia, rolipram diminished the area of tissue damage and improved memory deficits by attenuating neuronal loss in the hippocampus (Block et al., 1997, Li et al., 2011).
We here evaluated the efficacy and modes of rolipram action after transient middle cerebral artery occlusion (tMCAO) in mice, a model of focal brain ischemia/reperfusion injury.
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Animals and stroke model
131 six to eight weeks old, male C57Bl/6 mice were included in the study which was approved by institutional panels on animal care and governmental authorities (Regierung von Unterfranken, Würzburg, Germany). All stroke experiments were performed in accordance with the recently published ARRIVE guidelines (http://www.nc3rs.org/ARRIVE). Animals were randomly assigned to the treatment groups by an independent person not involved in data acquisition and analysis. We performed surgery and
Rolipram dose-dependently protects from ischemic brain damage in a therapeutic setting
First we tested the efficacy of rolipram in the tMCAO stroke model in mice. In this model neuronal damage critically depends on blood–brain-barrier damage, inflammation and progressive microvascular thrombosis (Kleinschnitz et al., 2006, Langhauser et al., 2012). Intraperitoneal application of 2 mg/kg rolipram 2 h after the onset of cerebral ischemia had no significant effect on stroke size (129.1 ± 10.8 mm3 [vehicle] vs. 103.3 ± 6.6 mm3 [2 mg/kg rolipram], P > 0.05) or functional outcomes (Bederson
Discussion
Here we show that the PDE4 inhibitor rolipram protects from stroke in mice in a “clinically” meaningful setting. Rolipram halved the infarct size and improved the neurological outcome when applied 2 h after the onset of ischemia. Combined antiinflammatory, antithrombotic, and antiapoptotic modes of rolipram action could be identified as underlying mechanisms.
It is well known that rolipram exerts beneficial effects after ischemia–reperfusion injury in different organs such as the lung (Souza et
Sources of funding
This work was supported by the Deutsche Forschungsgemeinschaft (DFG), SFB 688 (project A13 to CK) and the Interdisziplinäres Zentrum für Klinische Forschung Würzburg (IZKF; project E-35 to CK).
Disclosures
The authors declare no conflicts of interest.
The following are the supplementary data related to this article.
Acknowledgments
We are grateful to Daniela Urlaub, Andrea Sauer and Heike Menzel for expert technical assistance.
References (72)
- et al.
Ischemic stroke and traumatic brain injury: the role of the kallikrein–kinin system
Prog. Neurobiol.
(2013) - et al.
Sequential alteration of [3H]rolipram binding in gerbil brain after transient cerebral ischemia
Brain Res. Bull.
(1993) - et al.
Modulation of the cAMP signaling pathway after traumatic brain injury
Exp. Neurol.
(2007) - et al.
Effects of early rolipram treatment on histopathological outcome after controlled cortical impact injury in mice
Neurosci. Lett.
(2013) - et al.
Ischaemic brain oedema
J. Clin. Neurosci.
(2002) - et al.
Effects of rolipram on adult rat oligodendrocytes and functional recovery after contusive cervical spinal cord injury
Neuroscience
(2009) - et al.
Rolipram promotes functional recovery after contusive thoracic spinal cord injury in rats
Behav. Brain Res.
(2013) - et al.
Phosphodiesterase 4 inhibitors, structurally unrelated to rolipram, as promising agents for the treatment of asthma and other pathologies
Eur. J. Med. Chem.
(2000) - et al.
Treatment with BBB022A or rolipram stabilizes the blood–brain barrier in experimental autoimmune encephalomyelitis: an additional mechanism for the therapeutic effect of type IV phosphodiesterase inhibitors
J. Neuroimmunol.
(1999) - et al.
Preventive but not therapeutic application of Rolipram ameliorates experimental autoimmune encephalomyelitis in Lewis rats
J. Neuroimmunol.
(1996)
Rolipram: a specific phosphodiesterase 4 inhibitor with potential antipsychotic activity
Neuroscience
Alterations in [3H]MK-801, [3H]muscimol, [3H]cyclic AMP, and [3H]rolipram binding in the gerbil hippocampus following repeated ischemic insults
Neuroscience
Regulatory T cells are strong promoters of acute ischemic stroke in mice by inducing dysfunction of the cerebral microvasculature
Blood
Phosphodiesterase type IV inhibitors prevent ischemia–reperfusion-induced gastric injury in rats
J. Pharmacol. Sci.
Kininogen deficiency protects from ischemic neurodegeneration in mice by reducing thrombosis, blood–brain barrier damage, and inflammation
Blood
Differential effects of rolipram on chronic subcutaneous inflammatory angiogenesis and on peritoneal adhesion in mice
Microvasc. Res.
Enhanced protection from renal ischemia–reperfusion [correction of ischemia:reperfusion] injury with A(2A)-adenosine receptor activation and PDE 4 inhibition
Kidney Int.
The blood–brain barrier in brain homeostasis and neurological diseases
Biochim. Biophys. Acta
Rolipram attenuates acute oligodendrocyte death in the adult rat ventrolateral funiculus following contusive cervical spinal cord injury
Neurosci. Lett.
PDE4 regulates tissue plasminogen activator expression of human brain microvascular endothelial cells
Thromb. Res.
Interleukin-1 and neuronal injury
Nat. Rev. Immunol.
Contributions of LFA-1 and Mac-1 to brain injury and microvascular dysfunction induced by transient middle cerebral artery occlusion
Am. J. Physiol. Heart Circ. Physiol.
Postinjury treatment with rolipram increases hemorrhage after traumatic brain injury
J. Neurosci. Res.
Blockade of bradykinin receptor B1 but not bradykinin receptor B2 provides protection from cerebral infarction and brain edema
Stroke
Antiedema therapy in ischemic stroke
Stroke
Endothelin levels increase in rat focal and global ischemia
J. Cereb. Blood Flow Metab.
Rat middle cerebral artery occlusion: evaluation of the model and development of a neurologic examination
Stroke
Treatment with the phosphodiesterase type-4 inhibitor rolipram fails to inhibit blood–brain barrier disruption in multiple sclerosis
Mult. Scler.
Delayed treatment with rolipram protects against neuronal damage following global ischemia in rats
Neuroreport
Procedural and strain-related variables significantly affect outcome in a murine model of focal cerebral ischemia
Neurosurgery
Phosphodiesterase-4 inhibition attenuates pulmonary inflammation in neonatal lung injury
Eur. Respir. J.
Cerebral microvessel responses to focal ischemia
J. Cereb. Blood Flow Metab.
Update on the therapeutic potential of PDE4 inhibitors
Expert Opin. Investig. Drugs
The neurovascular unit as a selective barrier to polymorphonuclear granulocyte (PMN) infiltration into the brain after ischemic injury
Acta Neuropathol.
Prevention of autoimmune demyelination in non-human primates by a cAMP-specific phosphodiesterase inhibitor
Proc. Natl. Acad. Sci. U. S. A.
Proinflammatory cytokine regulation of cyclic AMP-phosphodiesterase 4 signaling in microglia in vitro and following CNS injury
Glia
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PK and TS contributed equally to this study.