minocycline and Cerebral-Hemorrhage

Intracerebral hemorrhage (ICH) is an important subtype of stroke with an unsatisfactory prognosis of high mortality and disability. Although many pre-clinical studies and clinical trials have been performed in the past decades, effective therapy that meaningfully improve prognosis and outcomes of ICH patients is still lacking. An active area of research is towards alleviating secondary brain injury after ICH through neuroprotective pharmaceuticals and in which minocycline is a promising candidate. Here, we will first discuss new insights into the protective mechanisms of minocycline for ICH including reducing iron-related toxicity, maintenance of blood-brain barrier, and alleviating different types of cell death from preclinical data, then consider its shortcomings. Finally, we will review clinical trial perspectives for minocycline in ICH. We hope that this summary and discussion about updated information on minocycline as a viable treatment for ICH can facilitate further investigations.

Topics: Blood-Brain Barrier; Brain Injuries; Cerebral Hemorrhage; Humans; Minocycline; Neuroprotective Agents

The neurological sequelae of Bacillus anthracis infection include a rapidly progressive fulminant meningoencephalitis frequently associated with intracranial hemorrhage, including subarachnoid and intracerebral hemorrhage. Higher mortality than other forms of bacterial meningitis suggests that antimicrobials and cardiopulmonary support alone may be insufficient and that strategies targeting the hemorrhage might improve outcomes. In this review, we describe the toxic role of intracranial hemorrhage in anthrax meningoencephalitis. We first examine the high incidence of intracranial hemorrhage in patients with anthrax meningoencephalitis. We then review common diseases that present with intracranial hemorrhage, including aneurysmal subarachnoid hemorrhage and spontaneous intracerebral hemorrhage, postulating applicability of established and potential neurointensive treatments to the multimodal management of hemorrhagic anthrax meningoencephalitis. Finally, we examine the therapeutic potential of minocycline, an antimicrobial that is effective against B. anthracis and that has been shown in preclinical studies to have neuroprotective properties, which thus might be repurposed for this historically fatal disease.

Topics: Anthrax; Bacillus anthracis; Cerebral Hemorrhage; Humans; Meningoencephalitis; Minocycline

Intracerebral haemorrhage is inadequately controlled by current treatments, requiring new solutions to improve the prognosis. Following the primary injury, a proinflammatory cascade in the perihaematomal region, composed of activated resident microglia and astrocytes and infiltrated leucocytes, propagates neural cell death. The protracted nature of neuroinflammation in intracerebral haemorrhage provides a window of opportunity for therapies to subdue the undesired consequences. In animal models and early clinical trials in intracerebral haemorrhage, several drugs have reduced detrimental neuroinflammation without substantial compromise of the beneficial reparative aspects of an inflammatory response. Potential strategies include controlling excessive harmful neuroinflammation with minocycline, sphingosine-1-phosphate receptor modulators, and statins after a brain haemorrhage. The quick initiation of these drugs, particularly in high systemic doses, could be key to counteracting the evolving secondary injury in people with intracerebral haemorrhage and provides a promising way in which the poor prognosis of intracerebral haemorrhage might one day be counteracted.

Topics: Animals; Anti-Infective Agents; Cerebral Hemorrhage; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Immunotherapy; Inflammation; Minocycline; Sphingosine 1 Phosphate Receptor Modulators; Translational Research, Biomedical

Various randomized-controlled clinical trials (RCTs) have investigated the neuroprotective role of minocycline in acute ischemic stroke (AIS) or acute intracerebral hemorrhage (ICH) patients. We sought to consolidate and investigate the efficacy and safety of minocycline in patients with acute stroke.. Literature search spanned through November 30, 2017 across major databases to identify all RCTs that reported following efficacy outcomes among acute stroke patients treated with minocycline vs. placebo: National Institute of Health Stroke Scale (NIHSS), Barthel Index (BI), and modified Rankin Scale (mRS) scores. Additional safety, neuroimaging and biochemical endpoints were extracted. We pooled mean differences (MD) and risk ratios (RR) from RCTs using random-effects models.. We identified 7 RCTs comprising a total of 426 patients. Of these, additional unpublished data was obtained on contacting corresponding authors of 5 RCTs. In pooled analysis, minocycline demonstrated a favorable trend towards 3-month functional independence (mRS-scores of 0-2) (RR = 1.31; 95% CI 0.98-1.74, p = 0.06) and 3-month BI (MD = 6.92; 95% CI - 0.92, 14.75; p = 0.08). In AIS subgroup, minocycline was associated with higher rates of 3-month mRS-scores of 0-2 (RR = 1.59; 95% CI 1.19-2.12, p = 0.002; I. Although data is limited, minocycline demonstrated efficacy and seems a promising neuroprotective agent in acute stroke patients, especially in AIS subgroup. Further RCTs are needed to evaluate the efficacy and safety of minocycline among ICH patients.

Topics: Brain Ischemia; Cerebral Hemorrhage; Humans; Minocycline; Neuroprotective Agents; Randomized Controlled Trials as Topic; Stroke

Minocycline, in animal models and 2 small randomized controlled human trials, is a promising neuroprotective agent in acute stroke. We analyzed the efficacy and safety of intravenous minocycline in acute ischemic and hemorrhagic stroke.. A multicenter prospective randomized open-label blinded end point evaluation pilot study of minocycline 100 mg administered intravenously, commenced within 24 hours of onset of stroke, and continued 12 hourly for a total of 5 doses, versus no minocycline. All participants received routine stroke care. Primary end point was survival free of handicap (modified Rankin Scale, ≤2) at day 90.. Ninety-five participants were randomized; 47 to minocycline and 48 to no minocycline. In the intention-to-treat population, 29 of 47 (65.9%) allocated minocycline survived free of handicap compared with 33 of 48 (70.2%) allocated no minocycline (rate ratio, 0.94; 95% confidence interval, 0.71-1.25 and odds ratio, 0.73; 95% CI, 0.31-1.71). A meta-analysis of the 3 human trials suggests minocycline may increase the odds of handicap-free survival by 3-fold (odds ratio, 2.99; 95% CI, 1.74-5.16) but there was substantial heterogeneity among the trials.. In this pilot study of a small sample of acute stroke patients, intravenous minocycline was safe but not efficacious. The study was not powered to identify reliably or exclude a modest but clinically important treatment effect of minocycline. Larger trials would improve the precision of the estimates of any treatment effect of minocycline.. http://www.anzctr.org.au. Unique identifier: ACTRN12612000237886.

Topics: Administration, Intravenous; Aged; Aged, 80 and over; Anti-Bacterial Agents; Brain Ischemia; Cerebral Hemorrhage; Female; Humans; Male; Middle Aged; Minocycline; Pilot Projects; Severity of Illness Index; Stroke; Treatment Outcome

Tissue plasminogen activator (tPA) administered within 4.5h of symptom onset restores cerebral blood flow (CBF) and promotes neurological recovery of stroke patients. However, the narrow therapeutic time window and the risk of intracerebral hemorrhage after tPA treatment pose major hurdles to its clinical usage. In light of the failures of neuroprotective therapies in clinical trials, emerging concepts suggest that neuroprotection alone without restoration of tissue perfusion and vascular integrity may not be adequate for treatment of acute stroke. Here we review evidence of the use of adjuvant pharmacological agents to extend the therapeutic window for tPA via targeting the neurovascular unit and the underlying mechanisms of the combination therapy in experimental stroke.

Topics: Anti-Bacterial Agents; Antineoplastic Agents; Boronic Acids; Bortezomib; Cerebral Hemorrhage; Drug Therapy, Combination; Erythropoietin; Fibrinolytic Agents; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Minocycline; Pyrazines; Stroke; Tissue Plasminogen Activator

Intracerebral hemorrhage (ICH) is a devastating neurological disorder with high mortality and poor prognosis, for which virtually no effective drug therapies are available at present. Experimental animal models, based on intrastriatal injection of collagenase or autologous blood, have enabled great advances in elucidation of cellular/molecular events contributing to brain pathogenesis associated with ICH. Many lines of evidence indicate that blood constituents, including hemoglobin-derived products as well as proteases such as thrombin, play important roles in the pathogenic events. Inflammatory reactions involving neutrophils, activated microglia, and production of proinflammatory cytokines also constitute a critical aspect of pathology leading to neurodegeneration and tissue damage. Efforts are continuing to find drugs that potentially alleviate pathological and neurological outcomes of ICH. Various drugs that possess antioxidative, anti-inflammatory or neurotrophic/neuroprotective properties have been demonstrated to produce therapeutic effects on ICH animal models. Drugs already in clinical use such as minocycline, statins, and several nuclear receptor ligands are among the list of effective drugs, but whether they also show therapeutic efficacy in human ICH patients remains unproven. Here, current knowledge of ICH pathogenesis and problems arising with respect to exploration of new drug candidates are discussed.

Topics: Animals; Cerebral Hemorrhage; Cytokines; Drug Design; Free Radical Scavengers; Glutamates; Heme; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Inflammation Mediators; Intercellular Signaling Peptides and Proteins; Ligands; Matrix Metalloproteinases; Minocycline; Neuroprotective Agents; Receptors, Cytoplasmic and Nuclear; Thrombin

The vascular events that happen during ischemic stroke worsen outcomes in patients by causing edema, hemorrhagic transformation, and general neurologic tissue compromise. In the past 2 decades, clinical trials in patients after ischemic stroke focused on neuroprotection, but these strategies have failed in providing actual benefit. Vascular protection represents a new field to be explored in acute ischemic stroke in order to develop new approaches to therapeutic intervention.. We identified tactics likely to provide vascular protection in patients with ischemic stroke. These tactics are based on knowledge of the molecular processes involved.. The pathologic processes due to vascular injury after an occlusion of a cerebral artery can be separated into acute (those occurring within hrs), subacute (hrs to days), and chronic (days to mo). Targets for intervention can be identified for all three stages. In the acute phase, superoxide is the predominant mediator, followed by inflammatory mediators and proteases in the subacute phase. In the chronic phase, proapoptotic gene products have been implicated. Many already-marketed therapeutic agents (statins, angiotensin modulators, erythropoietin, minocycline, and thiazolidinediones), with proven safety in patients, have been shown to have activity against some of the key targets of vascular protection.. Currently available pharmacologic agents are poised for clinical trials of vascular protection after acute ischemic stroke.

Topics: Acute Disease; Angiotensin-Converting Enzyme Inhibitors; Brain; Brain Edema; Brain Ischemia; Cerebral Hemorrhage; Chronic Disease; Erythropoietin; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Minocycline; Stroke; Thiazolidinediones; Thrombolytic Therapy

Cerebral amyloid angiopathy (CAA) is a disease caused by the accumulation of the amyloid-beta protein and is a major cause of intracerebral hemorrhage (ICH) and vascular dementia in the elderly. The presence of the amyloid-beta protein in the vessel wall may induce a chronic state of cerebral inflammation by activating astrocytes, microglia, and pro-inflammatory substances. Minocycline, an antibiotic of the tetracycline family, is known to modulate inflammation, gelatinase activity, and angiogenesis. These processes are suggested to be key mechanisms in CAA pathology. Our aim is to show the target engagement of minocycline and investigate in a double-blind placebo-controlled randomized clinical trial whether treatment with minocycline for 3 months can decrease markers of neuroinflammation and of the gelatinase pathway in cerebrospinal fluid (CSF) in CAA patients.. The BATMAN study population consists of 60 persons: 30 persons with hereditary Dutch type CAA (D-CAA) and 30 persons with sporadic CAA. They will be randomized for either placebo or minocycline (15 sporadic CAA/15 D-CAA minocycline, 15 sporadic CAA/15 D-CAA placebo). At t = 0 and t = 3 months, we will collect CSF and blood samples, perform a 7-T MRI, and collect demographic characteristics.. The results of this proof-of-principle study will be used to assess the potential of target engagement of minocycline for CAA. Therefore, our primary outcome measures are markers of neuroinflammation (IL-6, MCP-1, and IBA-1) and of the gelatinase pathway (MMP2/9 and VEGF) in CSF. Secondly, we will look at the progression of hemorrhagic markers on 7-T MRI before and after treatment and investigate serum biomarkers.. ClinicalTrials.gov NCT05680389. Registered on January 11, 2023.

Topics: Aged; Amyloid beta-Peptides; Anti-Bacterial Agents; Cerebral Amyloid Angiopathy; Cerebral Amyloid Angiopathy, Familial; Cerebral Hemorrhage; Gelatinases; Humans; Inflammation; Minocycline; Neuroinflammatory Diseases; Randomized Controlled Trials as Topic

Minocycline is under investigation as a neurovascular protective agent for stroke. This study evaluated the pharmacokinetic, anti-inflammatory, and safety profile of minocycline after intracerebral hemorrhage.. This study was a single-site, randomized controlled trial of minocycline conducted from 2013 to 2016. Adults ≥18 years with primary intracerebral hemorrhage who could have study drug administered within 24 hours of onset were included. Patients received 400 mg of intravenous minocycline, followed by 400 mg minocycline oral daily for 4 days. Serum concentrations of minocycline after the last oral dose and biomarkers were sampled to determine the peak concentration, half-life, and anti-inflammatory profile.. In intracerebral hemorrhage, a 400 mg dose of minocycline was safe and achieved neuroprotective serum concentrations. However, oral administration led to delayed absorption in these critically ill patients and should not be used when rapid, high concentrations are desired. Given the safety and pharmacokinetic profile of minocycline in intracerebral hemorrhage and promising data in the treatment of ischemic stroke, intravenous minocycline is an excellent candidate for a prehospital treatment trial.. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01805895.

Topics: Acute Disease; Administration, Intravenous; Cerebral Hemorrhage; Female; Humans; Male; Minocycline; Neuroprotective Agents; Treatment Outcome

Intracerebral hemorrhage (ICH) is a devastating cerebrovascular disorder with high morbidity and mortality. Minocycline is a matrix metalloproteinase-9 (MMP-9) inhibitor that may attenuate secondary mechanisms of injury in ICH. The feasibility and safety of minocycline in ICH patients were evaluated in a pilot, double-blinded, placebo-controlled randomized clinical trial.. Patients with acute onset (<12 h from symptom onset) ICH and small initial hematoma volume (<30 ml) were randomized to high-dose (10 mg/kg) intravenous minocycline or placebo. The outcome events included adverse events, change in serial National Institutes of Health Stroke Scale score assessments, hematoma volume and MMP-9 measurements, 3-month functional outcome (modified Rankin score) and mortality.. A total of 20 patients were randomized to minocycline (n = 10) or placebo (n = 10). The two groups did not differ in terms of baseline characteristics. No serious adverse events or complications were noted with minocycline infusion. The two groups did not differ in any of the clinical and radiological outcomes. Day 5 serum MMP-9 levels tended to be lower in the minocycline group (372 ± 216 ng/ml vs. 472 ± 235 ng/ml; P = 0.052). Multiple linear regression analysis showed that minocycline was associated with a 217.65 (95% confidence interval -425.21 to -10.10, P = 0.041) decrease in MMP-9 levels between days 1 and 5.. High-dose intravenous minocycline can be safely administered to patients with ICH. Larger randomized clinical trials evaluating the efficacy of minocycline and MMP-9 inhibition in ICH patients are required.

Topics: Adult; Aged; Cerebral Hemorrhage; Double-Blind Method; Female; Humans; Male; Matrix Metalloproteinase Inhibitors; Middle Aged; Minocycline; Pilot Projects; Treatment Outcome

Minocycline, in animal models and 2 small randomized controlled human trials, is a promising neuroprotective agent in acute stroke. We analyzed the efficacy and safety of intravenous minocycline in acute ischemic and hemorrhagic stroke.. A multicenter prospective randomized open-label blinded end point evaluation pilot study of minocycline 100 mg administered intravenously, commenced within 24 hours of onset of stroke, and continued 12 hourly for a total of 5 doses, versus no minocycline. All participants received routine stroke care. Primary end point was survival free of handicap (modified Rankin Scale, ≤2) at day 90.. Ninety-five participants were randomized; 47 to minocycline and 48 to no minocycline. In the intention-to-treat population, 29 of 47 (65.9%) allocated minocycline survived free of handicap compared with 33 of 48 (70.2%) allocated no minocycline (rate ratio, 0.94; 95% confidence interval, 0.71-1.25 and odds ratio, 0.73; 95% CI, 0.31-1.71). A meta-analysis of the 3 human trials suggests minocycline may increase the odds of handicap-free survival by 3-fold (odds ratio, 2.99; 95% CI, 1.74-5.16) but there was substantial heterogeneity among the trials.. In this pilot study of a small sample of acute stroke patients, intravenous minocycline was safe but not efficacious. The study was not powered to identify reliably or exclude a modest but clinically important treatment effect of minocycline. Larger trials would improve the precision of the estimates of any treatment effect of minocycline.. http://www.anzctr.org.au. Unique identifier: ACTRN12612000237886.

Topics: Administration, Intravenous; Aged; Aged, 80 and over; Anti-Bacterial Agents; Brain Ischemia; Cerebral Hemorrhage; Female; Humans; Male; Middle Aged; Minocycline; Pilot Projects; Severity of Illness Index; Stroke; Treatment Outcome

Ischemic animal model studies have shown a neuroprotective effect of minocycline.. To analyze the effect of minocycline treatment in human acute ischemic stroke.. We performed an open-label, evaluator-blinded study. Minocycline at a dosage of 200 mg was administered orally for 5 days. The therapeutic window of time was 6 to 24 hours after onset of stroke. Data from NIH Stroke Scale (NIHSS), modified Rankin Scale (mRS), and Barthel Index (BI) were evaluated. The primary objective was to compare changes from baseline to day 90 in NIHSS in the minocycline group vs placebo.. One hundred fifty-two patients were included in the study. Seventy-four patients received minocycline treatment, and 77 received placebo. NIHSS and mRS were significantly lower and BI scores were significantly higher in minocycline-treated patients. This pattern was already apparent on day 7 and day 30 of follow-up. Deaths, myocardial infarctions, recurrent strokes, and hemorrhagic transformations during follow-up did not differ by treatment group.. Patients with acute stroke had significantly better outcome with minocycline treatment compared with placebo. The findings suggest a potential benefit of minocycline in acute ischemic stroke.

Topics: Acute Disease; Aged; Anti-Bacterial Agents; Anti-Inflammatory Agents; Apoptosis; Cerebral Hemorrhage; Female; Gliosis; Humans; Hypoxia-Ischemia, Brain; Male; Microglia; Middle Aged; Minocycline; Mortality; Myocardial Infarction; Neuroprotective Agents; Placebos; Secondary Prevention; Signal Transduction; Single-Blind Method; Stroke; Treatment Outcome

Intracerebral hemorrhage is primarily a disease of the elderly and it is frequently accompanied by intraventricular hemorrhage (IVH) which can lead to posthemorrhagic hydrocephalus and poor prognosis. Red blood cell iron has been implicated in brain injury after cerebral hemorrhage. The current study examined using T2* magnetic resonance imaging (MRI) to detect periventricular iron deposition after IVH and investigated the effects of minocycline on hydrocephalus in an aged rat IVH model. It had three parts. In part 1, male aged rats received a 200 μl injection of saline or autologous blood into the lateral ventricle and were euthanized at day 14. In parts 2 and 3, aged IVH rats were treated with vehicle or minocycline and euthanized at day 7 or 14. Rats underwent MRI to quantify hydrocephalus and iron deposition followed by brain histology and immunohistochemistry. Periventricular iron overload was found after IVH using T2* MRI and confirmed by histology. IVH also caused ventricular wall damage and increased the number of CD68(+) choroid plexus epiplexus cells. Minocycline administration reduced iron deposition and ventricular volume at days 7 and 14 after IVH, as well as ventricle wall damage and epiplexus cell activation. In summary, IVH-induced hydrocephalus is associated with periventricular iron deposition, ependymal damage and choroid plexus epiplexus cell activation in aged rats. Minocycline attenuated those effects and might be a potential treatment for posthemorrhagic hydrocephalus in the elderly.

Topics: Aged; Animals; Cerebral Hemorrhage; Humans; Hydrocephalus; Iron; Male; Minocycline; Rats; Rats, Sprague-Dawley

Neuroinflammation is a major reason for white matter injury (WMI) after intracerebral hemorrhage (ICH). Apart from microglia/macrophage activation, T cells also play an important role in regulating immune responses after ICH. In a previous study, we have revealed the role of minocycline in modulating microglia/macrophage activation after ICH. However, the exact mechanisms of minocycline in regulating T cells differentiation after ICH are still not well understood. Hence, this study explored the relationship between minocycline and CD4

Topics: Animals; Brain Injuries; CD4-Positive T-Lymphocytes; Cell Differentiation; Cerebral Hemorrhage; Microglia; Minocycline; Signal Transduction; Swine; White Matter

The complement cascade is activated and may play an important pathophysiologic role in brain injury after experimental intracerebral hemorrhage (ICH). However, the exact mechanism of specific complement components has not been well studied. This study determined the role of complement C1q/C3-CR3 signaling in brain injury after ICH in mice. The effect of minocycline on C1q/C3-CR3 signaling-induced brain damage was also examined.. There were three parts to the study. First, the natural time course of C1q and CR3 expression was determined within 7 days after ICH. Second, mice had an ICH with CR3 agonists, LA-1 or vehicle. Behavioral score, neuronal cell death, hematoma volume, and oxidative stress response were assessed at 7 days after ICH. Third, the effect of minocycline on C1q/C3-CR3 signaling and brain damage was examined.. There were increased numbers of C1q-positive and CR3-positive cells after ICH. Almost all perihematomal C1q-positive and CR3-positive cells were microglia/macrophages. CR3 agonist LA-1 aggravated neurological dysfunction, neuronal cell death, and oxidative stress response on day 7 after ICH, as well as enhancing the expression of the CD163/HO-1 pathway and accelerating hematoma resolution. Minocycline treatment exerted neuroprotective effects on brain injury following ICH, partly due to the inhibition of C1q/C3-CR3 signaling, and that could be reversed by LA-1.. The complement C1q/C3-CR3 signaling is upregulated after ICH. The activation of C1q/C3-CR3 signaling by LA-1 aggravates brain injury following ICH. The neuroprotection of minocycline, at least partly, is involved with the repression of the C1q/C3-CR3 signaling pathway.

Topics: Animals; Brain Injuries; Cerebral Hemorrhage; Complement C1q; Hematoma; Mice; Minocycline; Neuroprotective Agents; Signal Transduction

Intracerebral hemorrhage (ICH) is a severe neurological dysfunction and a medical emergency with a high mortality rate. Minocycline ameliorates deficits in rodent models of acute and chronic neurological diseases. However, the role of minocycline in ICH remains unclear. The extracellular matrix metalloproteinase inducer (EMMPRIN) is a key inflammatory mediator in some neurological diseases, triggering matrix metalloproteinases (MMPs) production. In this study, we aimed to use minocycline to inhibit EMMPRIN and thus the activity of MMPs. Male adult C57BL/6 mice were injected with collagenase type VII or saline into the right basal ganglia and euthanized at different time points. The minocycline was intraperitoneally injected once every 12 h for three days to block the expression of EMMPRIN from two hours after ICH. We found that breakdown of the BBB was most severe 3 days after ICH. The minocycline treatment significantly decreased EMMPRIN and MMP-9 expression, reduced zonula occludens-1 and occludin, and alleviated BBB disruption. Moreover, minocycline treatment displayed a lower brain water content, lesser neurological dysfunction, and smaller injury volume on day 3 than those of the vehicle-treated group. Minocycline also inhibited the activation of microglia/macrophages, infiltration of neutrophils, and production of inflammatory mediators, including tumor necrosis factor alpha and interleukin-1beta. The current study shows that minocycline exhibits protective roles in ICH by decreasing EMMPRIN and MMP-9 expression, alleviating BBB disruption, inhibiting neuroinflammation, areducing neuronal degeneration and death.

Topics: Animals; Basigin; Blood-Brain Barrier; Cerebral Hemorrhage; Disease Models, Animal; Humans; Injections, Intraperitoneal; Male; Matrix Metalloproteinase 9; Mice; Minocycline; Neuroprotective Agents

Iron-mediated toxicity is a key factor causing brain injury after intracerebral hemorrhage (ICH). This study was performed to investigate the noninvasive neuroimaging method for quantifying brain iron content using a minipig ICH model and assess the effects of minocycline treatment on ICH-induced iron overload and brain injury. The minipig ICH model was established by injecting 2 ml of autologous blood into the right basal ganglia, which were then subjected to the treatments of minocycline and vehicle. Furthermore, the quantitative susceptibility mapping (QSM) was used to quantify iron content, and diffusion tensor imaging (DTI) was performed to evaluate white matter tract. Additionally, we also performed immunohistochemistry, Western blot, iron assay, Perl's staining, brain water content, and neurological score to evaluate the iron overload and brain injury. Interestingly, we found that the ICH-induced iron overload could be accurately quantified by the QSM. Moreover, the minocycline was quite beneficial for protecting brain injury by reducing the lesion volume and brain edema, preventing brain iron accumulation, downsizing ventricle enlargement, and alleviating white matter injury and neurological deficits. In summary, we suggest that the QSM be an accurate and noninvasive method for quantifying brain iron level, and the minocycline may be a promising therapeutic agent for patients with ICH.

Topics: Animals; Brain; Cerebral Hemorrhage; Chelating Agents; Iron; Magnetic Resonance Imaging; Male; Minocycline; Swine; Swine, Miniature

White matter (WM) injury after intracerebral hemorrhage (ICH) results in poor or even fatal outcomes. As an anti-inflammatory drug, minocycline has been considered a promising choice to treat brain injury after ICH. However, whether minocycline can reduce WM injury after ICH is still controversial. In the present study, we investigate the effect and underlying mechanism of minocycline on WM injury after ICH.. An ICH model was induced by an injection of autologous blood into the right frontal lobe of piglets. First, transcriptional analysis was performed at day 1 or 3 to investigate the dynamic changes in neuroinflammatory gene expression in WM after ICH. Second, ICH piglets were treated either with minocycline or with vehicle alone. All piglets then underwent magnetic resonance imaging to measure brain swelling. Brain tissue was used for real-time polymerase chain reaction (RT-PCR), immunohistochemistry, Western blot, and electron microscopy.. Transcriptional analysis demonstrated that transforming growth factor-β (TGF-β)/mitogen-activated protein kinase (MAPK) signaling is associated with microglia/macrophage-mediated inflammation activation after ICH and is then involved in WM injury after ICH in piglets. Minocycline treatment results in less ICH-induced brain swelling, fewer neurological deficits, and less WM injury in comparison with the vehicle alone. In addition, minocycline reduces microglial activation and alleviates demyelination in white matter after ICH. Finally, we found that minocycline attenuates WM injury by increasing the expression of TGF-β and suppressing MAPK activation after ICH.. These results indicate that TGF-β-mediated MAPK signaling contributes to WM injury after ICH, which can be altered by minocycline treatment.

Topics: Animals; Animals, Newborn; Brain; Brain Injuries; Cerebral Hemorrhage; Male; Minocycline; Swine; White Matter

Brain iron overload is involved in brain injury after intracerebral hemorrhage (ICH). There is evidence that systemic administration of minocycline reduces brain iron level and improves neurological outcome in experimental models of hemorrhagic and ischemic stroke. However, there is evidence in cerebral ischemia that minocycline is not protective in aged female animals. Since most ICH research has used male models, this study was designed to provide an overall view of ICH-induced iron deposits at different time points (1 to 28 days) in aged (18-month old) female Fischer 344 rat ICH model and to investigate the neuroprotective effects of minocycline in those rats. According to our previous studies, we used the following dosing regimen (20 mg/kg, i.p. at 2 and 12 h after ICH onset followed by 10 mg/kg, i.p., twice a day up to 7 days). T2-, T2

Topics: Aging; Animals; Brain; Brain Injuries; Cerebral Hemorrhage; Female; Iron Overload; Minocycline; Neuroprotective Agents; Rats; Rats, Inbred F344

Disruption of the blood-brain barrier (BBB) and subsequent neurological deficits are the most severe consequence of intracerebral hemorrhage (ICH). Minocycline has been wildly used clinically as a neurological protective agent in clinical practice. However, the underlying mechanisms by which minocycline functions remain unclear. Therefore, we assessed the influence of minocycline on BBB structure, neurological function, and inflammatory responses in a collagenase-induced ICH model, and elucidated underlying molecular mechanisms as well. Following a single injection of collagenase VII-S into the basal ganglia, BBB integrity was assessed by Evans blue extravasation while neurological function was assessed using an established neurologic function scoring system. Minocycline treatment significantly alleviated the severity of BBB disruption, brain edema, and neurological deficits in ICH model. Moreover, minocycline decreased the production of inflammatory mediators including TNF, IL-6, and MMP-9, by microglia. Minocycline treatment decreased DKK1 expression but increased Wnt1, β-catenin and Occludin, a phenomenon mimicked by DKK1 silencing. These data suggest that minocycline improves the consequences of ICH by preserving BBB integrity and attenuating neurologic deficits in a DKK1-related manner that involves enhancement of the Wnt1-β-catenin activity.

Topics: Animals; beta Catenin; Blood-Brain Barrier; Brain Edema; Cerebral Hemorrhage; Disease Models, Animal; Inflammation; Intercellular Signaling Peptides and Proteins; Interleukin-6; Male; Matrix Metalloproteinase 9; Microbial Collagenase; Microglia; Minocycline; Neuroprotective Agents; Occludin; Rats; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha; Wnt Signaling Pathway; Wnt1 Protein

Topics: Brain Ischemia; Cerebral Hemorrhage; Humans; Minocycline

Topics: Cerebral Hemorrhage; Humans; Minocycline

Brain iron overload is a key factor causing brain injury after intracerebral hemorrhage (ICH). This study quantified brain iron levels after ICH with magnetic resonance imaging R2* mapping. The effect of minocycline on iron overload and ICH-induced brain injury in aged rats was also determined.. Aged (18 months old) male Fischer 344 rats had an intracerebral injection of autologous blood or saline, and brain iron levels were measured by magnetic resonance imaging R2* mapping. Some ICH rats were treated with minocycline or vehicle. The rats were euthanized at days 7 and 28 after ICH, and brains were used for immunohistochemistry and Western blot analyses. Magnetic resonance imaging (T2-weighted, T2* gradient-echo, and R2* mapping) sequences were performed at different time points.. ICH-induced brain iron overload in the perihematomal area could be quantified by R2* mapping. Minocycline treatment reduced brain iron accumulation, T2* lesion volume, iron-handling protein upregulation, neuronal cell death, and neurological deficits (. Magnetic resonance imaging R2* mapping is a reliable and noninvasive method, which can quantitatively measure brain iron levels after ICH. Minocycline reduced ICH-related perihematomal iron accumulation and brain injury in aged rats.

Topics: Animals; Anti-Bacterial Agents; Blotting, Western; Brain; Cell Death; Cerebral Hemorrhage; Disease Models, Animal; Dopamine and cAMP-Regulated Phosphoprotein 32; Ferritins; Heme Oxygenase (Decyclizing); Immunohistochemistry; Iron Overload; Magnetic Resonance Imaging; Male; Minocycline; Neurons; Rats; Rats, Inbred F344

Intracerebral hemorrhage (ICH) is a devastating disease worldwide with increasing mortality. The present study investigated whether minocycline was neuroprotective and induced M2 microglial polarization via upregulation of the TrkB/BDNF pathway after ICH. ICH was induced via injection of autologous blood into 150 Sprague-Dawley rats. A selective TrkB antagonist [N2-2-2-oxoazepan-3-yl amino] carbonyl phenyl benzo (b) thiophene-2-carboxamide (ANA 12)] and agonist [ N-[2-(5-hydroxy-1H-indol-3-yl) ethyl]-2-oxopiperidine-3-carboxamide (HIOC)] were used to investigate the mechanism of minocycline-induced neuroprotection. Minocycline improved ICH-induced neurological deficits and reduced M1 microglia marker protein (CD68, CD16) expression as well as M2 microglial polarization (CD206 and arginase 1 protein). Minocycline administration enhanced microglia-neuron cross talk and promoted the proliferation of neuronal progenitor cells, such as DCX- and Tuj-1-positive cells, 24 h after ICH. Minocycline also increased M2 microglia-derived brain-derived neurotrophic factors (BDNF) and the upstream TrkB pathway. ANA 12 reversed the neuroprotective effects of minocycline. HIOC exhibited the same effects as minocycline and accelerated neurogenesis after ICH. This study demonstrated for the first time that minocycline promoted M2 microglia polarization via upregulation of the TrkB/BDNF pathway and promoted neurogenesis after ICH. This study contributes to our understanding of the therapeutic potential of minocycline in ICH. NEW & NOTEWORTHY The present study gives several novel points: 1) Minocycline promotes neurogenesis after intracerebral hemorrhage in rats. 2) Minocycline induces activated M1 microglia into M2 neurotrophic phenotype. 3) M2 microglia secreting BDNF remodel the damaged neurocircuit.

Topics: Animals; Brain-Derived Neurotrophic Factor; Cerebral Cortex; Cerebral Hemorrhage; Doublecortin Protein; Maze Learning; Microglia; Minocycline; Neurogenesis; Neuroprotective Agents; Rats, Sprague-Dawley; Receptor, trkB; Signal Transduction; Up-Regulation

The role of surgery for most patients with spontaneous intracerebral haemorrhage (ICH) remains controversial due to the continuous occurrence of postoperative iron overload induced by low clot clearance rate. In this study, human hair keratose hydrogel (KG) loading with minocycline hydrochloride (MH) were prepared to reduce iron overload for the improvement of the postoperative functional recovery after ICH aspiration surgery. Hemoglobin-induced iron accumulation in rat primary neuronal culture was delayed by the adsorptive capacity of blank KG, while MH-loaded KG displayed a stronger and more thorough cytoprotective effect than blank KG due to the combined effect of absorptive action to iron and sustained release of the iron chelator. Moreover, high iron-chelating efficiency in the hematoma region supplied by MH-loaded KG significantly reduced dose strength of iron chelator. In situ injection of KG with different MH loadings (2, 20, and 200μg) into the hematoma region after aspiration surgery showed a stronger effect on the reduction of ICH-induced iron accumulation, edema, and neurological deficits in rats compared to the postoperative intraperitoneal administration of MH (approximately 15mg). These results suggested that the in situ KG not only could effectively reduce the ICH postoperative iron overload and improve the postoperative functional recovery via the iron adsorption and sustained release of MH, but also has great potential to reduce the systemic adverse effects by decreasing the dose strength of iron chelator.

Topics: Animals; Cerebral Hemorrhage; Chelating Agents; Delayed-Action Preparations; Disease Models, Animal; Female; Hematoma; Hemoglobins; Humans; Hydrogels; Iron; Iron Overload; Keratosis; Male; Minocycline; Neurons; Postoperative Hemorrhage; Pregnancy; Rats; Rats, Sprague-Dawley

OBJECTIVE Intracerebral hemorrhage (ICH) is a fatal disease with high morbidity and mortality, which may be followed by white matter injury (WMI) due to the local oxidizing reaction induced by iron (Fe). In this study, the authors examined the effect of the tetracycline antibiotic minocycline on Fe-induced WMI and c-Jun N-terminal kinase (JNK) activation in rats. METHODS Thirty-six male Sprague-Dawley rats underwent an intracaudate injection of saline, Fe, or Fe + minocycline. Another 36 rats had an intracaudate injection of autologous blood and were treated with minocycline or vehicle (saline). Biomarkers of both WMI and JNK activation were examined. RESULTS In the Fe-injection group, minocycline suppressed WMI labeled by β-amyloid precursor protein (β-APP) and degraded myelin basic protein (dMBP)/MBP ratio. Protein levels of phosphorylated-JNK were increased after Fe injection, and could be suppressed by minocycline treatment. In the autologous blood-injection group, β-APP and dMBP/MBP levels increased in the ipsilateral site compared with the contralateral site, which could be suppressed by 7 days of minocycline intervention. CONCLUSIONS Iron plays a critical role in WMI after ICH, which can be suppressed by minocycline through reducing the damage induced by Fe.

Topics: Amyloid beta-Protein Precursor; Animals; Anti-Bacterial Agents; Cerebral Hemorrhage; Disease Models, Animal; Leukoencephalopathies; Male; Minocycline; Myelin Basic Protein; Phosphorylation; Rats; Rats, Sprague-Dawley; White Matter

Intracerebral hemorrhage is the least treatable type of stroke and affects millions of people worldwide. Treatment for ICH varies from medicine to surgery, but the rate of mortality and mobility still remains high. Minocycline is a tetracycline antibiotic increasingly recognized for its neuroprotective potential. In earlier studies, we demonstrated that many secondary injuries caused by ICH could be significantly reduced by injection of minocycline in rat models. The following research investigates the role of minocycline in reducing brain injury.. Twenty-four rats were administered 100μl autologous arterial blood injections into the right basal ganglia, treated with minocycline or vehicle and euthanized on the 1st, 3rd, and 7th day. Immunohistochemistry, TUNEL, and western blot analysis were performed to analyze the effects of minocycline on apoptosis and autophagy.. After the injection of minocycline, TUNEL-positive cells were remarkably reduced on days 1, 3 and 7; Beclin-1, LC3BII/I, caspase-3/8 were all suppressed after treatment. The relationship between Cathepsin D and minocycline remained unknown.. Our studies suggest the potential medicinal value of minocycline, through both anti-autophagy and anti-apoptosis pathways.

Topics: Animals; Apoptosis; Autophagy; Basal Ganglia; Beclin-1; Blotting, Western; Caspase 3; Caspase 8; Cathepsin D; Cerebral Hemorrhage; Disease Models, Animal; Drug Evaluation, Preclinical; Immunohistochemistry; In Situ Nick-End Labeling; Male; Minocycline; Neurons; Neuroprotective Agents; Rats, Sprague-Dawley

Germinal matrix hemorrhage (GMH) is the most important adverse neurologic event during the newborn period. Evidence has shown that neonates with GMH and hydrocephalus have more severe damage compared to those with GMH alone. Our preliminary study demonstrated the role of iron in hydrocephalus and brain damage in adult rats following intraventricular hemorrhage. Therefore, the aim of the current study was to investigate iron accumulation and iron-handling proteins in a rat model of GMH and whether minocycline reduces iron overload after GMH and iron-induced brain injury in vivo. This study was divided into two parts. In the first part, rats received either a needle insertion or an intracerebral injection of 0.3 U of clostridial collagenase VII-S. Brain iron and brain iron handling proteins (heme oxygenase-1 and ferritin) were measured. In the second part, rats with a GMH were treated with minocycline or vehicle. Brain edema, brain cell death, hydrocephalus, iron-handling proteins and long-term motor function were examined. The result showed iron accumulation and upregulation of iron-handling proteins after GMH. Minocycline treatment significantly reduced GMH-induced brain edema, hydrocephalus and brain damage. Minocycline also suppressed upregulation of ferritin after GMH. In conclusion, the current study found that iron plays a role in brain injury following GMH and that minocycline reduces iron overload after GMH and iron-induced brain injury.

Topics: Animals; Blotting, Western; Brain Edema; Cerebral Hemorrhage; Disease Models, Animal; Immunohistochemistry; In Situ Nick-End Labeling; Iron Overload; Minocycline; Neuroprotective Agents; Rats; Rats, Sprague-Dawley

Cerebral amyloid angiopathy (CAA) is a common cause of recurrent intracerebral hemorrhage in the elderly. Previous studies have shown that CAA induces inflammation and expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 (gelatinases) in amyloid-laden vessels. Here, we inhibited both using minocycline in CAA mouse models to determine whether spontaneous intracerebral hemorrhage could be reduced.. Tg2576 (n=16) and 5xFAD/ApoE4 knockin mice (n=16), aged 17 and 12 months, respectively, were treated with minocycline (50 mg/kg, IP) or saline every other day for 2 months. Brains were extracted and stained with X-34 (to quantify amyloid), Perls' blue (to quantify hemorrhage), and immunostained to examined β-amyloid peptide load, gliosis (glial fibrillary acidic protein [GFAP], Iba-1), and vascular markers of blood-brain barrier integrity (zonula occludins-1 [ZO-1] and collagen IV). Brain extracts were used to quantify mRNA for a variety of inflammatory genes.. Minocycline treatment significantly reduced hemorrhage frequency in the brains of Tg2576 and 5xFAD/ApoE4 mice relative to the saline-treated mice, without affecting CAA load. Gliosis (GFAP and Iba-1 immunostaining), gelatinase activity, and expression of a variety of inflammatory genes (matrix metalloproteinase-9, NOX4, CD45, S-100b, and Iba-1) were also significantly reduced. Higher levels of microvascular tight junction and basal lamina proteins were found in the brains of minocycline-treated Tg2576 mice relative to saline-treated controls.. Minocycline reduced gliosis, inflammatory gene expression, gelatinase activity, and spontaneous hemorrhage in 2 different mouse models of CAA, supporting the importance of matrix metalloproteinase-related and inflammatory pathways in intracerebral hemorrhage pathogenesis. As a Food and Drug Administration-approved drug, minocycline might be considered for clinical trials to test efficacy in preventing CAA-related intracerebral hemorrhage.

Topics: Animals; Anti-Bacterial Agents; Calcium-Binding Proteins; Cerebral Amyloid Angiopathy; Cerebral Hemorrhage; Disease Models, Animal; Drug Evaluation, Preclinical; Gene Expression Regulation; Glial Fibrillary Acidic Protein; Inflammation; Leukocyte Common Antigens; Matrix Metalloproteinase 9; Mice; Mice, Transgenic; Microfilament Proteins; Minocycline; NADPH Oxidase 4; NADPH Oxidases; Nerve Tissue Proteins; S100 Calcium Binding Protein beta Subunit

Central post-stroke pain (CPSP) including thalamic pain is one of the most troublesome sequelae that can occur after a cerebrovascular accident. Although the prevalence of CPSP among stroke patients is relatively low, the persistent, often treatment-refractory, painful sensations can be a major problem and decrease the affected patient's quality of life. To better understand of the pathophysiological basis of CPSP, we developed and characterized a new mouse model of thalamic CPSP. This model is based on a hemorrhagic stroke lesion with collagenase in the ventral posterolateral nucleus of the thalamus. Histopathological analysis indicated that the thalamic hemorrhage produced a relatively confined lesion that destroys the tissue within the initial bleed, and also showed the presence of activated microglia adjacent to the core of hemorrhagic lesions. Behavioral analysis demonstrated that the animals displayed diclofenac-, morphine- or pregabalin-resistant mechanical allodynia and thermal hyperalgesia of the hind paw contralateral to the lesion for over 112 days. However, we found that minocycline, a microglial inhibitor, significantly ameliorated mechanical allodynia and thermal hyperalgesia. These results suggest that this model might be proved as a useful animal model for studying the neuropathology of thalamic syndrome, and developing improved therapeutics for CPSP.

Topics: Analgesics, Non-Narcotic; Animals; Cerebral Hemorrhage; Collagenases; Disease Models, Animal; Hyperalgesia; Male; Mice; Mice, Inbred C57BL; Minocycline; Nociceptive Pain; Pain Threshold; Stroke; Thalamic Diseases; Ventral Thalamic Nuclei

Poststroke hyperglycemia is associated with resistance to tissue plasminogen activator (tPA) reperfusion, higher risk of intracerebral hemorrhage, and worse neurological outcomes. In this study, we asked whether minocycline combined with intravenous tPA may ameliorate inflammation and brain injury after focal embolic stroke in type 1 diabetic rats.. Type 1 diabetic rats were subjected to a focal embolic stroke. Three treatment groups were used: (1) saline at 1.5 hours after stroke; (2) tPA alone at 1.5 hours after stroke; (3) combined minocycline (intravenously) at 1 hour plus tPA at 1.5 hours, and second treatment of minocycline (intraperitoneally) at 12 hours after stroke. Acute brain tissue damages were assessed at 24 hours after stroke. Inflammatory biomarkers interleukin-1β and matrix metalloproteinases 2 and 9 were examined in plasma. Neutrophil infiltration, microglia activation, matrix metalloproteinase activation, and degradation of the tight junction protein claudin-5 were examined in the brain.. Compared with saline or tPA alone treatments, minocycline plus tPA combination therapy significantly reduced brain infarction, intracerebral hemorrhage, and hemispheric swelling at 24 hours after stroke. The combination also significantly suppressed the elevated plasma levels of matrix metalloproteinase-9 and interleukin-1β up to 24 hours after stroke. At 16 hours after stroke, neutrophil infiltration, microglia activation, matrix metalloproteinase-9, and tight junction protein claudin-5 degradation in the peri-infarct brain tissues were also significantly attenuated by the combination therapy.. Combination therapy with minocycline plus tPA may be beneficial in ameliorating inflammation and reducing infarction, brain swelling, and hemorrhage after ischemic stroke with diabetes mellitus/hyperglycemia.

Topics: Animals; Anti-Bacterial Agents; Cerebral Hemorrhage; Claudin-5; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Disease Models, Animal; Drug Therapy, Combination; Fibrinolytic Agents; Interleukin-1beta; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Minocycline; Rats; Rats, Wistar; Risk Factors; Streptozocin; Stroke; Tissue Plasminogen Activator

to investigate the changes of blood-brain barrier (BBB) permeability and expressions of VEGF, NGF and HPS70 in brain at different time points following intracerebral hemorrhage (ICH) in rats, and observe therapeutic effect of minocycline (MC).. rat ICH model was induced with Type IV collagenase. Early MC treatment was administrated via intraperitoneal injection. BBB permeability was evaluated by Evans blue (EB) amount exuded out of cerebral vessels. VEGF, NGF, and HPS70 expressions were determined with immunohistochemical staining.. EB exudation amount in MC treatment group was less than the ICH group (P < 0.05). The former showed a transient EB exudation peak only 1 h after modeling and then gradually decreased, while the latter showed two EB exudation peaks 1 and 4 days after modeling, respectively. The number of VEGF-positive cells in MC treatment group was less than the ICH group (P < 0.05), whereas the number of NGF- and HSP70-positive cells were more than the ICH group (P < 0.05). All three were mainly expressed in neurons and gitter cells, but there were only few expressions in the control group.. after ICH, the BBB permeability was destroyed, with neuron function affected. In the early stage, VEGF increased BBB permeability, while NGF and HSP70 showed protective effects on nerve cells. Early intraperitoneal injection with MC could reduce the damage of BBB and increase the protective effect on nerve cells, the mechanism of which may be achieved by reducing VEGF expression and enhancing NGF and HSP70 expressions.

Topics: Analysis of Variance; Animals; Blood-Brain Barrier; Brain; Capillary Permeability; Cell Count; Cerebral Hemorrhage; Disease Models, Animal; Evans Blue; Gene Expression Regulation; HSP70 Heat-Shock Proteins; Male; Minocycline; Nerve Growth Factor; Rats; Rats, Sprague-Dawley; Time Factors; Vascular Endothelial Growth Factor A

Brain iron overload plays a detrimental role in brain injury after intracerebral hemorrhage (ICH). A recent study found that minocycline acts as an iron chelator and reduces iron-induced neuronal death in vitro. The present study investigated if minocycline reduces iron overload after ICH and iron-induced brain injury in vivo.. This study was divided into 4 parts: (1) rats with different sizes of ICH were euthanized 3 days later for serum total iron and brain edema determination; (2) rats had an ICH treated with minocycline or vehicle. Serum iron, brain iron, and brain iron handling proteins were measured; (3) rats had an intracaudate injection of saline, iron, iron+minocycline, or iron+macrophage/microglia inhibitory factor and were used for brain edema and neuronal death measurements; and (4) rats had an intracaudate injection of iron and were treated with minocycline. The brains were used for edema measurement.. After ICH, serum total iron and brain nonheme iron increased and these changes were reduced by minocycline treatment. Minocycline also reduced ICH-induced upregulation of brain iron handling proteins and neuronal death. Intracaudate injection of iron caused brain edema, blood-brain barrier leakage, and brain cell death, all of which were significantly reduced by coinjection with minocycline.. The current study found that minocycline reduces iron overload after ICH and iron-induced brain injury. It is also well known minocycline is an inhibitor of microglial activation. Minocycline may be very useful for patients with ICH because both iron accumulation and microglia activation contribute to brain damage after ICH.

Topics: Animals; Blood-Brain Barrier; Brain; Brain Injuries; Cell Count; Cell Death; Cerebral Hemorrhage; Iron; Iron Overload; Male; Microglia; Minocycline; Neurons; Rats; Rats, Sprague-Dawley

Evidence suggests that microglia activation contributes to brain injury after intracerebral hemorrhage (ICH). The present study aimed to determine if minocycline, an inhibitor of microglia activation, can reduce brain edema, brain atrophy and neurological deficits after ICH.Male Sprague-Dawley rats received an infusion of 100-microL autologous whole blood into the right basal ganglia. Rats received minocycline or vehicle treatment. There were two sets of experiments in this study. In the first set of experiments, the effects of minocycline on ICH-induced brain edema were examined at day 3. In the second set, behavioral tests were performed at days 1, 3, 7, 14 and 28. Rats were killed at day 28 for brain atrophy measurement (caudate and lateral ventricle size).Minocycline reduced perihematomal brain edema in the ipsilateral basal ganglia (78.8 +/- 0.4 vs. 80.9 +/- 1.1% in the vehicle-treated group, p < 0.01). Minocycline also improved functional outcome. In addition, minocycline reduced brain tissue loss in the ipsilateral caudate (p < 0.01) and ventricular enlargement (p < 0.05).In conclusion, minocycline attenuates ICH-induced brain edema formation, neurological deficits and brain atrophy in rats suggesting an important role of microglia in ICH-related brain injury.

Topics: Analysis of Variance; Animals; Atrophy; Brain; Brain Edema; Caudate Nucleus; Cerebral Hemorrhage; Disease Models, Animal; Lateral Ventricles; Male; Minocycline; Nervous System Diseases; Neurologic Examination; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Time Factors

Minocycline ameliorates deficits in models of acute and chronic neurological diseases, but many publications do not replicate these results. We tested the hypothesis that a key factor in achieving neurological benefits is the exposure of neural cells to local high concentrations of minocycline. This hypothesis was evaluated by using human neurons in culture and in a mouse model of intracerebral hemorrhage (ICH). In culture, neurons were very vulnerable to blood-induced toxicity, with 60% lost within 24 hours in an environment of 5% blood in culture medium. Minocycline reduced blood-induced neurotoxicity in a concentration-dependent manner. In vivo, the introduction of blood into the striatum of mice to simulate ICH resulted in a massive lesion by 24 hours. When minocycline was mixed with the blood used to inflict ICH, the resulting extent of neuropathology was significantly less than that achieved with intraperitoneal administration of medication. The combination of intracerebral and intraperitoneal minocycline improved neuroprotection compared with either alone. We then delayed minocycline treatment and injected it into the hematoma 1 hour after ICH. We found greater alleviation of brain damage and neuronal death with increasing concentrations of minocycline injected locally, which was reflected in limited behavioral and histological recovery. We conclude that the prospect of neuroprotection with minocycline is improved by high concentrations of minocycline delivered locally into the central nervous system with supplementation from systemic administration.

Topics: Animals; Brain; Cell Death; Cells, Cultured; Cerebral Hemorrhage; Dose-Response Relationship, Drug; Gelatin; Humans; Injections, Intraventricular; Male; Mice; Minocycline; Neurons; Neuroprotective Agents; Time Factors; Treatment Outcome

Microglial activation and thrombin formation contribute to brain injury after intracerebral hemorrhage. Tumor necrosis factor-alpha and interleukin-1beta are two major pro-inflammatory cytokines. The present study investigated if thrombin stimulates tumor necrosis factor-alpha and interleukin-1beta secretion in vitro and if microglial inhibition reduces intracerebral hemorrhage-induced brain injury in vivo.. There were two parts in this study. In the first part, cultured rat microglial cells were treated with vehicle, thrombin (10 U/ml) or thrombin plus minocycline (1 or 10 microM), an inhibitor of microglia activation. Levels of tumor necrosis factor-alpha and interleukin-1beta in culture medium were measured by enzyme-linked immunosorbent assay 24 hours after thrombin treatment. In the second part, rats had an intracerebral injection of 100 microl autologous whole blood. Rats received minocycline or vehicle treatment. Brain edema was measured at day 3 and brain atrophy was determined at day 28 after intracerebral hemorrhage.. Thrombin receptors were expressed in cultured microglia cells, and tumor necrosis factor-alpha and interleukin-1beta levels in the culture medium were increased after thrombin treatment. Minocycline reduced thrombin-induced up-regulation of tumor necrosis factor-alpha and interleukin-1beta. In vivo, minocycline reduced perihematomal brain edema, neurological deficits and brain atrophy.. Thrombin stimulates microglia to release the pro-inflammatory cytokines, tumor necrosis factor-alpha and interleukin-1beta, and microglial inhibition with minocycline reduces brain injury after intracerebral hemorrhage, suggesting a critical role of microglia activation in intracerebral hemorrhage-related brain injury.

Topics: Animals; Brain; Brain Edema; Brain Injuries; Cells, Cultured; Cerebral Hemorrhage; Collagenases; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Enzyme-Linked Immunosorbent Assay; Functional Laterality; Hemostatics; Interleukin-1beta; Male; Microglia; Minocycline; Neurologic Examination; Rats; Thrombin; Tumor Necrosis Factor-alpha

Iron neurotoxicity may contribute to the pathogenesis of intracerebral hemorrhage (ICH). The tetracycline derivative minocycline is protective in ICH models, due putatively to inhibition of microglial activation. Although minocycline also chelates iron, its effect on iron neurotoxicity has not been reported, and was examined in this study. Cortical cultures treated with 10 microM ferrous sulfate for 24h sustained loss of most neurons and an increase in malondialdehyde. Minocycline prevented this injury, with near-complete protection at 30 microM. Two other inhibitors of microglial activation, doxycycline and macrophage/microglia inhibitory factor, were ineffective. Oxidation of isolated culture membranes by iron was also inhibited by minocycline. Consistent with prior observations, minocycline chelated iron in a siderophore colorometric assay; at concentrations less than 100 microM, its activity exceeded that of deferoxamine. These results suggest that attenuation of iron neurotoxicity may contribute to the beneficial effect of minocycline in hemorrhagic stroke and other CNS injury models.

Topics: Animals; Cerebral Cortex; Cerebral Hemorrhage; Cytoprotection; Deferoxamine; Iron; Iron Chelating Agents; Mice; Mice, Inbred Strains; Minocycline; Neurons; Neuroprotective Agents; Neurotoxicity Syndromes

New treatment strategies for acute ischemic stroke must be evaluated in the context of effective reperfusion. Minocycline is a neuroprotective agent that inhibits proteolytic enzymes and therefore could potentially both inactivate the clot lysis effect and decrease the damaging effects of tissue-type plasminogen activator (t-PA). This study aimed to determine the effect of minocycline on t-PA clot lysis and t-PA-induced hemorrhage formation after ischemia.. Fibrinolytic and amidolytic activities of t-PA were investigated in vitro over a range of clinically relevant minocycline concentrations. A suture occlusion model of 3-hour temporary cerebral ischemia in rats treated with t-PA and 2 different minocycline regimens was used. Blood-brain barrier basal lamina components, matrix metalloproteinases (MMPs), hemorrhage formation, infarct size, edema, and behavior outcome were assessed.. Minocycline did not affect t-PA fibrinolysis. However, minocycline treatment at 3 mg/kg IV decreased total protein expression of both MMP-2 (P=0.0034) and MMP-9 (P=0.001 for 92 kDa and P=0.0084 for 87 kDa). It also decreased the incidence of hemorrhage (P=0.019), improved neurologic outcome (P=0.0001 for Bederson score and P=0.0391 for paw grasp test), and appeared to decrease mortality. MMP inhibition was associated with decreased degradation in collagen IV and laminin-alpha1 (P=0.0001).. Combination treatment with minocycline is beneficial in t-PA-treated animals and does not compromise clot lysis. These results also suggest that neurovascular protection by minocycline after stroke may involve direct protection of the blood-brain barrier during thrombolysis with t-PA.

Topics: Animals; Anti-Bacterial Agents; Blood-Brain Barrier; Brain Ischemia; Cerebral Hemorrhage; Drug Evaluation, Preclinical; Fibrinolysis; Gene Expression Regulation; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Minocycline; Neuroprotective Agents; Rats; Rats, Wistar; Stroke; Tissue Plasminogen Activator

Thrombolysis with tPA is the only FDA-approved therapy for acute ischemic stroke. But its widespread application remains limited by narrow treatment time windows and the related risks of cerebral hemorrhage. In this study, we ask whether minocycline can prevent tPA-associated cerebral hemorrhage and extend the reperfusion window in an experimental stroke model in rats.. Spontaneously hypertensive rats were subjected to embolic focal ischemia using homologous clots and treated with: saline at 1 hour; early tPA at 1 hour, delayed tPA at 6 hours; minocycline at 4 hours; combined minocycline at 4 hours plus tPA at 6 hours. Infarct volumes and hemorrhagic transformation were quantified at 24 hours. Gelatin zymography was used to measure blood levels of circulating matrix metalloproteinase-9 (MMP-9).. Early 1-hour thrombolysis restored perfusion and reduced infarction. Late 6-hour tPA did not decrease infarction but instead worsened hemorrhagic conversion. Combining minocycline with delayed 6-hour tPA decreased plasma MMP-9 levels, reduced infarction, and ameliorated brain hemorrhage. Blood levels of MMP-9 were also significantly correlated with volumes of infarction and hemorrhage.. Combination therapy with minocycline may extend tPA treatment time windows in ischemic stroke.

Topics: Animals; Biomarkers; Blood-Brain Barrier; Brain Ischemia; Cerebral Hemorrhage; Cerebral Infarction; Drug Administration Schedule; Drug Evaluation, Preclinical; Fibrinolytic Agents; Intracranial Embolism; Male; Matrix Metalloproteinase 9; Matrix Metalloproteinase Inhibitors; Minocycline; Neuroprotective Agents; Rats; Rats, Inbred SHR; Recombinant Proteins; Reperfusion; Thrombolytic Therapy; Time Factors; Tissue Plasminogen Activator

After intracerebral hemorrhage (ICH), blood entry is followed by neuron death and an inflammatory response, but development of pharmacological therapies has been hampered by an inadequate understanding of the spatial and temporal relationship between neuron death and inflammation. Using a rat model of ICH, we first investigated these relationships at 6 h, and 1, 3 and 7 days. At the edge of the hematoma, no degenerating neurons were observed at 6 h; however, dying neurons were present between 1 and 3 days, with peak neuron death occurring at 1 day. This is apparently the first report of ongoing neuron death at the edge of the hematoma during a time window that is appropriate for human therapy. Neuron death was limited to the edge of the hematoma, with no degenerating neurons in the striatum surrounding the hematoma, despite robust and prolonged microglia activation. Importantly, neuron loss at the edge of the hematoma was spatially and temporally associated with accumulation and activation of microglia/macrophages. We then tested the hypothesis that treatment with the tetracycline derivative, minocycline, after the hematoma had reached a maximal size, will reduce inflammation and neuron damage. Minocycline injection (45 mg/kg i.v. at 6 h, and i.p. at 24, 48 and 72 h) failed to reduce neuron loss outside the hematoma or striatal tissue loss (assessed at 7 days), despite reducing the number of neutrophils and activated microglia/macrophages. Thus, minocycline does not appear to target the mechanisms responsible for cell death in this model of ICH.

Topics: Animals; Blood Circulation; Cell Count; Cell Death; Cerebral Hemorrhage; Disease Models, Animal; Drug Administration Schedule; Functional Laterality; Immunohistochemistry; Inflammation; Male; Minocycline; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Spectrophotometry; Time Factors

Human brain arteriovenous malformation tissue displays increased levels of vascular endothelial growth factor (VEGF) as well as matrix metalloproteinase (MMP)-9, a tissue protease associated with various intracerebral hemorrhage (ICH). We hypothesized that increased MMP-9 was associated with ICH induced by vascular endothelial growth factor hyperstimulation and that this effect could be attenuated by nonspecific MMP inhibition.. We used a mouse model with adenoviral vector-mediated vascular endothelial growth factor transduction in the brain. The association of MMP-9 expression and the brain tissue hemoglobin levels, an index of ICH, after stereotactic injection of adenoviral vector-mediated vascular endothelial growth factor into caudate putamen was assessed. A dose-response study with adenoviral vector-mediated vascular endothelial growth factor and a time course study at both 24 and 48 hours postinjection were performed. Effects of minocycline, a nonspecific MMP inhibitor, and pyrrolidine dithiocarbamate, an upstream regulator of MMPs, on MMP-9 activity and thereby the degree of ICH were also tested.. Adenoviral vector-mediated vascular endothelial growth factor at the higher dose and at 48 hours induced MMP-9 levels 6-fold (n=6, P=0.02) and increased brain tissue hemoglobin (43.4+/-11.5 versus 30.3+/-4.1 mug/mg, n=6, P=0.003) compared with the adenoviral vector control. Immnunostaining was positive for MMP-9 around the cerebral vessels and the hemorrhagic areas. Minocycline and pyrrolidine dithiocarbamate administration suppressed vascular endothelial growth factor-induced MMP-9 activity (n=6, P=0.003 and P=0.01, respectively) and the associated increases in hemoglobin levels (n=5-6, P=0.001 and P=0.02, respectively).. Vascular endothelial growth factor-induced ICH is associated with increased MMP-9 expression. Suppression of MMP-9 by minocycline or pyrrolidine dithiocarbamate attenuated ICH, suggesting the therapeutic potential of MMP inhibitors in cerebral vascular rupture.

Topics: Adenoviridae; Animals; Anti-Bacterial Agents; Antioxidants; Brain; Cerebral Hemorrhage; Disease Models, Animal; Humans; Intracranial Arteriovenous Malformations; Male; Matrix Metalloproteinase 9; Matrix Metalloproteinase Inhibitors; Mice; Minocycline; Pyrrolidines; Thiocarbamates; Vascular Endothelial Growth Factor A

Intracerebral hemorrhage (ICH) results from rupture of a blood vessel in the brain. After ICH, the blood-brain barrier (BBB) surrounding the hematoma is disrupted, leading to cerebral edema. In both animals and humans, edema coincides with inflammation, which is characterized by production of pro-inflammatory cytokines, activation of resident brain microglia and migration of peripheral immune cells into the brain. Accordingly, inflammation is an attractive target for reducing edema following ICH. In the present study, BBB damage was assessed by quantifying intact microvessels surrounding the hematoma, monitoring extravasation of IgG and measuring brain water content 3 days after ICH induced by collagenase injection into the rat striatum. In the injured brain, the water content increased in both ipsilateral and contralateral hemispheres compared with the normal brain. Quantitative real-time RT-PCR revealed an up-regulation of inflammatory genes associated with BBB damage; IL1beta, TNFalpha and most notably, MMP-12. Immunostaining showed MMP-12 in damaged microvessels and their subsequent loss from tissue surrounding the hematoma. MMP-12 was also observed for the first time in neurons. Dual-antibody labeling demonstrated that neutrophils were the predominant source of TNFalpha protein. Intraperitoneal injection of the tetracycline derivative, minocycline, beginning 6 h after ICH ameliorated the damage by reducing microvessel loss, extravasation of plasma proteins and edema; decreasing TNFalpha and MMP-12 expression; and reducing the numbers of TNFalpha-positive cells and neutrophils in the brain. Thus, minocycline, administered at a clinically relevant time, appears to target the inflammatory processes involved in edema development after ICH.

Topics: Animals; Blood-Brain Barrier; Brain Edema; Cerebral Hemorrhage; Collagen Type IV; Cytokines; Disease Models, Animal; Functional Laterality; Gene Expression Regulation; Male; Minocycline; Nerve Tissue Proteins; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Time Factors

There are no effective treatments for intracerebral hemorrhage (ICH). Although inflammation is a potential therapeutic target, there is a dearth of information about time-dependent and cell-specific changes in the expression of inflammation-related genes. Using the collagenase-induced ICH model in rats and real-time quantitative RT-PCR we monitored mRNA levels of markers of glial activation, pro- and anti-inflammatory cytokines, enzymes responsible for cytokine activation and several matrix metalloproteases at 6 h and 1, 3 and 7 days after ICH onset. For the most highly up-regulated genes, immunohistochemistry was then used to identify cell-specific protein expression. Finally, minocycline, a drug widely reported to reduce damage in several models of brain injury, was used to test the hypothesis that it can reduce up-regulation of inflammation-related genes when administered using a clinically relevant dosing regime: intraperitoneal injection beginning 6 h after ICH. Our results show a complex inflammatory response, with different brain cell types producing several pro- and anti-inflammatory molecules for at least 7 days after ICH onset. Included is the first demonstration that astrocytes are an important source of interleukin-1beta (IL-1beta), interleukin-1 receptor antagonist (IL-1ra), interleukin-6 (IL-6) and MMP-12. Importantly, our results demonstrate that while delayed minocycline treatment effectively reduces early up-regulation of TNFalpha and MMP-12, its efficacy is lost when treatment is extended for up to a week, and it does not reduce several other genes associated with microglia activation. These results suggest caution in extrapolating to ICH the promising results of minocycline treatment in other models of brain injury.

Topics: Animals; Brain; Brain Injuries; Cerebral Hemorrhage; Cytokines; Disease Models, Animal; Drug Administration Schedule; Follow-Up Studies; Gene Expression Regulation; Male; Matrix Metalloproteinases; Minocycline; Nerve Tissue Proteins; Neuroglia; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; RNA, Messenger; Severity of Illness Index; Treatment Outcome

Intracerebral hemorrhage (ICH) is a devastating condition currently lacking a defined line of treatment. The inflammatory response that ensues following its onset is thought to contribute to secondary injury following ICH, making inflammation a potential therapeutic target. Minocycline (MC), a commonly used antibiotic that also has anti-inflammatory and anti-apoptotic properties, provides histological protection in several animal stroke models when given soon after injury. However, its ability to provide protection with more clinically relevant delays is unknown. The objective of this study was to examine the effects of MC on histopathological changes and long-term functional outcomes in a collagenase-induced ICH model in rats when drug administration was delayed 3 h following the onset of ICH. In accordance with other studies, MC suppressed microglial/macrophage activation in the peri-infarct region at 5 days based on B4 isolectin histochemistry. However, no reduction in infarct volume was detected at 5 or 28 days post-ICH. Minocycline given for either 5 or 14 days also provided no functional benefit as assessed with a battery of sensory-motor tests (i.e., staircase, cylinder, ladder tests). These findings raise questions about the ability of MC to provide protection in ICH when delay to treatment is increased.

Topics: Animals; Anti-Bacterial Agents; Anti-Inflammatory Agents, Non-Steroidal; Behavior, Animal; Cerebral Hemorrhage; Cerebral Hemorrhage, Traumatic; Cerebral Infarction; Macrophages; Male; Microglia; Minocycline; Neostriatum; Rats; Rats, Long-Evans; Survival Analysis; Time Factors

Blood-brain barrier (BBB) disruption after stroke can worsen ischemic injury by increasing edema and causing hemorrhage. We determined the effect of microglia on the BBB and its primary constituents, endothelial cells (ECs) and astrocytes, after ischemia using in vivo and in vitro models.. Primary astrocytes, ECs, or cocultures were prepared with or without added microglia. Primary ECs were more resistant to oxygen-glucose deprivation/reperfusion than astrocytes. ECs plus astrocytes showed intermediate vulnerability. Microglia added to cocultures nearly doubled cell death. This increase was prevented by minocycline and apocynin. In vivo, minocycline reduced infarct volume and neurological deficits and markedly reduced BBB disruption and hemorrhage in mice after experimental stroke.. Inhibition of microglial activation may protect the brain after ischemic stroke by improving BBB viability and integrity. Microglial inhibitors may prove to be an important treatment adjunct to fibrinolysis.

Topics: Acetophenones; Animals; Antioxidants; Astrocytes; Blood-Brain Barrier; Brain; Brain Ischemia; Cell Death; Cells, Cultured; Cerebral Hemorrhage; Cerebral Infarction; Coculture Techniques; Endothelial Cells; Glucose; Hydrogen Peroxide; Hypoxia; Male; Mice; Mice, Inbred C57BL; Microglia; Minocycline; Nervous System Diseases; Superoxides; Tumor Necrosis Factor-alpha

Early reperfusion after an ischemic stroke can cause blood-brain barrier injury with subsequent cerebral edema and devastating brain hemorrhage. These complications of early reperfusion, which result from excess production of reactive oxygen species, significantly limit the benefits of stroke therapies. In this article, we use a novel animal model that facilitates identification of specific components of the reperfusion injury process, including vascular injury and secondary brain damage, and allows assessment of therapeutic interventions.. Knock-out (KO) mice containing 50% manganese-superoxide dismutase activity (SOD2-KO) and transgenic mice overexpressing SOD2 undergo transient focal ischemia and reperfusion followed by assessment of infarct, edema, hemorrhage rates, metalloproteinase activation, and microvascular injury.. SOD2-KO mice demonstrate delayed (>24h) blood-brain barrier breakdown associated with activation of matrix metalloproteinases, inflammation, and high brain hemorrhage rates. These adverse consequences are absent in wild-type littermates and minocycline-treated SOD2-KO animals. Increased hemorrhage rates also are absent in SOD2 overexpressors, which have reduced vascular endothelial cell death. Finally, we show that the tight junction membrane protein, occludin, is an early and specific target in oxidative stress-induced microvascular injury.. This model is ideal for studying ischemia/reperfusion-induced vascular injury and secondary brain hemorrhage and offers a unique opportunity to evaluate antioxidant-based neurovascular protective strategies as potential adjunct treatments to currently approved stroke therapies such as thrombolysis and endovascular clot retrieval.

Topics: Animals; Blood-Brain Barrier; Blotting, Western; Brain; Brain Ischemia; Cerebral Hemorrhage; Disease Models, Animal; Enzyme Inhibitors; In Situ Nick-End Labeling; Matrix Metalloproteinase 9; Mice; Mice, Knockout; Mice, Transgenic; Minocycline; Oxidative Stress; Reperfusion Injury; Superoxide Dismutase

Intracerebral hemorrhage (ICH) is characterized by parenchymal hematoma formation with surrounding inflammation. Matrix metalloproteinases (MMPs) have been implicated in the pathogenesis of neurological diseases defined by inflammation and cell death. To investigate the expression profile and pathogenic aspects of MMPs in ICH, we examined MMP expression in vivo using a collagenase-induced rat model of ICH. ICH increased brain MMP-2, -3, -7, and -9 mRNA levels relative to sham-injected (control) animals in the vicinity of the hematoma, but MMP-12 (macrophage metalloelastase) was the most highly induced MMP (>80-fold). Immunohistochemistry showed MMP-12 to be localized in activated monocytoid cells surrounding the hematoma. In vitro studies showed that thrombin, released during ICH, induced MMP-12 expression in monocytoid cells, which was reduced by minocycline application. Similarly, in vivo minocycline treatment significantly reduced MMP-12 levels in brain. Neuropathological studies disclosed marked glial activation and apoptosis after ICH that was reduced by minocycline treatment. Neurobehavioral outcomes also were improved with minocycline treatment compared with untreated ICH controls. Thus, select MMPs exhibit increased expression after ICH, whereas minocycline is neuroprotective after ICH by suppressing monocytoid cell activation and downregulating MMP-12 expression.

Topics: Animals; Anti-Bacterial Agents; Antibodies; Blotting, Western; Cell Culture Techniques; Cell Death; Cerebral Hemorrhage; Down-Regulation; Gene Expression; Immunohistochemistry; Injections, Intraperitoneal; Macrophages; Magnetic Resonance Imaging; Male; Matrix Metalloproteinase 12; Matrix Metalloproteinases; Metalloendopeptidases; Minocycline; Molecular Sequence Data; Polymerase Chain Reaction; Rats; Rats, Sprague-Dawley; RNA, Messenger; Thrombin