Effects of Surgery and Antiplatelet Therapy in Ten-Year Follow-Up from the Registry Study of Research Committee on Moyamoya Disease in Japan.

BACKGROUND: Despite the common practice of surgery and antiplatelet therapy for the prevention of recurrent stroke in patients with moyamoya disease, the benefit of these treatments is controversial. We analyzed the stroke recurrence rate in the Registry Study of Research Committee on Moyamoya Disease in Japan funded by the Health, Labor and Welfare Ministry of Japan. METHODS: An annual follow-up study of the registered cases was continued for 10 years. The rate of recurrent stroke, including cerebral infarction and hemorrhage but not transient ischemic attack and seizure, was evaluated with Kaplan-Meier analysis. RESULTS: The proportion of childhood-onset cases decreased in recently registered cases (within 10 years, n = 541) compared to remote cases (> 10 years, n = 735). Among types at disease onset in adult-onset cases, intracerebral hemorrhage decreased recently. In recent cases, the rate of subsequent cerebral hemorrhage was much higher in the hemorrhagic group (10.9 ± 3.3%/5 years) than in the ischemic group (2.0 ± .9%/5 years). The recurrence rate of cerebral infarction was lower in the surgery group (1.8 ± .9%/5 years) than in the nonsurgery group (3.8 ± 2.2%/5 years). In the adult-onset ischemic group, the proportion of surgically treated patients increased and their recurrence rate was lower than that of nonsurgery patients. In the ischemic group, the rate of cerebral infarction was not significantly different between the antiplatelet subgroup and the non-antiplatelet subgroup, whereas the rate of cerebral hemorrhage was higher in the non-antiplatelet subgroup than in the antiplatelet subgroup. CONCLUSIONS: Our results suggest revascularization surgery may suppress recurrent ischemic attacks in patients with moyamoya disease.

The natural course of unruptured cerebral aneurysms in a Japanese cohort.

BACKGROUND: The natural history of unruptured cerebral aneurysms has not been clearly defined. METHODS: From January 2001 through April 2004, we enrolled patients with newly identified, unruptured cerebral aneurysms in Japan. Information on the rupture of aneurysms, deaths, and the results of periodic follow-up examinations were recorded. We included 5720 patients 20 years of age or older (mean age, 62.5 years; 68% women) who had saccular aneurysms that were 3 mm or more in the largest dimension and who initially presented with no more than a slight disability. RESULTS: Of the 6697 aneurysms studied, 91% were discovered incidentally. Most aneurysms were in the middle cerebral arteries (36%) and the internal carotid arteries (34%). The mean (±SD) size of the aneurysms was 5.7±3.6 mm. During a follow-up period that included 11,660 aneurysm-years, ruptures were documented in 111 patients, with an annual rate of rupture of 0.95% (95% confidence interval [CI], 0.79 to 1.15). The risk of rupture increased with increasing size of the aneurysm. With aneurysms that were 3 to 4 mm in size as the reference, the hazard ratios for size categories were as follows: 5 to 6 mm, 1.13 (95% CI, 0.58 to 2.22); 7 to 9 mm, 3.35 (95% CI, 1.87 to 6.00); 10 to 24 mm, 9.09 (95% CI, 5.25 to 15.74); and 25 mm or larger, 76.26 (95% CI, 32.76 to 177.54). As compared with aneurysms in the middle cerebral arteries, those in the posterior and anterior communicating arteries were more likely to rupture (hazard ratio, 1.90 [95% CI, 1.12 to 3.21] and 2.02 [95% CI, 1.13 to 3.58], respectively). Aneurysms with a daughter sac (an irregular protrusion of the wall of the aneurysm) were also more likely to rupture (hazard ratio, 1.63; 95% CI, 1.08 to 2.48). CONCLUSIONS: This study showed that the natural course of unruptured cerebral aneurysms varies according to the size, location, and shape of the aneurysm. (Funded by the Ministry of Health, Labor, and Welfare in Japan and others; UCAS Japan UMIN-CTR number, C000000418.).

Efficacy and safety of eldecalcitol, a new active vitamin D3 analog, in the bone metabolism of postmenopausal women receiving maintenance hemodialysis.

Eldecalcitol (ELD), a new active vitamin D3 analog developed in Japan, has attracted attention as an effective osteoporotic therapeutic drug. However, because ELD leads to greater calcium absorption than does conventional active vitamin D3, it has yet to be used in patients with renal insufficiency. Therefore, we evaluated the efficacy and safety of ELD treatment in 27 postmenopausal women receiving maintenance dialysis in our institution and underwent ELD treatment (starting at 0.5 µg/day) for 6 months. The mean serum albumin-corrected calcium (Caalb) level was significantly increased following treatment (9.01 ± 0.60 before versus 9.56 ± 0.55 after treatment, mean ± SD). Severe hypercalcemia was prevented through cessation or adjustment of the dosage of calcium-containing phosphate binders or existing active vitamin D. The mean serum phosphorus and intact parathyroid hormone levels were well-controlled throughout. The median levels of bone turnover markers, bone-specific alkaline phosphatase and tartrate-resistant acid phosphatase-5b were significantly decreased. The mean lumbar spine bone mineral density (BMD) was increased, a significant difference being observed in age-matched Z-scores (-0.60 ± 1.6 versus -0.36 ± 1.5, p = 0.018). The average change in lumbar spine BMD after ELD treatment was 3.10%, and in patients with a T-score of <-4.0, it was 5.63%. There was no effect on forearm BMD. Although this study is based on short-term observation in a single institution, our results suggest that ELD could be used to increase bone density in dialysis patients.

Effects of extracranial-intracranial bypass for patients with hemorrhagic moyamoya disease: results of the Japan Adult Moyamoya Trial.

BACKGROUND AND PURPOSE: About one half of those who develop adult-onset moyamoya disease experience intracranial hemorrhage. Despite the extremely high frequency of rebleeding attacks and poor prognosis, measures to prevent rebleeding have not been established. The purpose of this study is to determine whether extracranial-intracranial bypass can reduce incidence of rebleeding and improve patient prognosis. METHODS: This study was a multicentered, prospective, randomized, controlled trial conducted by 22 institutes in Japan. Adult patients with moyamoya disease who had experienced intracranial hemorrhage within the preceding year were given either conservative care or bilateral extracranial-intracranial direct bypass and were observed for 5 years. Primary and secondary end points were defined as all adverse events and rebleeding attacks, respectively. RESULTS: Eighty patients were enrolled (surgical, 42; nonsurgical, 38). Adverse events causing significant morbidity were observed in 6 patients in the surgical group (14.3%) and 13 patients in the nonsurgical group (34.2%). Kaplan-Meier survival analysis revealed significant differences between the 2 groups (3.2%/y versus 8.2%/y; P=0.048). The hazard ratio of the surgical group calculated by Cox regression analysis was 0.391 (95% confidence interval, 0.148-1.029). Rebleeding attacks were observed in 5 patients in the surgical group (11.9%) and 12 in the nonsurgical group (31.6%), significantly different in the Kaplan-Meier survival analysis (2.7%/y versus 7.6%/y; P=0.042). The hazard ratio of the surgical group was 0.355 (95% confidence interval, 0.125-1.009). CONCLUSIONS: Although statistically marginal, Kaplan-Meier analysis revealed the significant difference between surgical and nonsurgical group, suggesting the preventive effect of direct bypass against rebleeding. CLINICAL TRIAL REGISTRATION URL: http://www.umin.ac.jp/ctr/index.htm. Unique identifier: C000000166.

The leptomeningeal ivy sign on fluid-attenuated inversion recovery images in moyamoya disease: positron emission tomography study.

BACKGROUND: The ivy sign is sometimes seen on fluid-attenuated inversion recovery (FLAIR) images in moyamoya disease (MMD). In recent studies using single-photon emission computed tomography, ivy sign proliferation correlated with decreases in cerebrovascular reserve. However, a decreased vascular reserve is not concrete. The purpose of this study was to evaluate the correlation between ivy sign proliferation and the findings of 15O gas positron emission tomography (PET). METHODS: In 19 MMD patients (12 women, age 31-69 years) with ischemic symptoms, FLAIR magnetic resonance imaging and 15O gas PET were performed. We classified the middle cerebral artery (MCA) territory into 2 regions in each hemisphere, and the degree of the ivy sign (ivy sign score) in each region was classified into 3 grades (0-2), where grade 0 indicated an absence of the ivy sign, grade 1 indicated that the ivy sign was seen on less than half of the cortical surface in each region, and grade 2 indicated that the ivy sign was seen on more than half of the cortical surface. We examined the relationship among the ivy sign score, the severity of ischemic symptoms and PET parameters in 76 MCA regions of 19 patients. RESULTS: Ivy sign scores of the regions were 0 (n = 19), 1 (n = 40), and 2 (n = 17). Total ivy sign score of a hemisphere increased as clinical symptoms became more severe. Cerebral blood flow (CBF) values were lower, cerebral blood volume (CBV) values were higher, and CBF/CBV values were lower than those of controls as symptoms became severe (p < 0.05). CBF and CBF/CBV values decreased and CBV values increased as the ivy sign score increased, and were significantly higher and lower, respectively, than control values (p < 0.05). No significant differences in cerebral metabolic rate of oxygen and oxygen extraction fraction were found between the 3 ivy sign scores. A positive correlation was found between ivy sign score and increases in CBV (p < 0.01), and a more obvious negative correlation was found between ivy sign score and decreases in CBF/CBV (p < 0.001). CONCLUSIONS: We evaluated the correlation between ivy sign proliferation and the findings of 15O gas PET. We suggested that ivy sign proliferation was associated with both dilated pial vasculature and the slow flow of developed leptomeningeal collaterals in patients with MMD.

Emerging effects of sevelamer in chronic kidney disease.

Sevelamer, a non-absorbable anion exchange resin, is used to control hyperphosphatemia in chronic kidney disease (CKD) by binding to dietary phosphate in the gastrointestinal tract. Lipid-lowering effect is a widely recognized pleiotropic effect of sevelamer. In addition, many studies have reported that sevelamer leads to reduced vascular calcification compared with calcium-containing phosphate binders, which is attributed to the improved lipid profiles and decreased calcium load. In addition, recent studies have suggested novel pleiotropic effects on bone structure, inflammation, oxidative stress, anemia, fetuin-A, and trace element metabolism in CKD patients. All of these effects have the potential to suppress the development/progression of cardiovascular lesions and reduce mortality. This review summarizes novel findings from recent studies and discusses the potential pleiotropic effects of sevelamer on non-traditional cardiovascular risk factors in CKD patients.

Hybrid operating room for the treatment of complex neurovascular and brachiocephalic lesions.

BACKGROUND: We examine the impact of the installation of integrated hybrid operating rooms (ORs) that allow both surgical and endovascular procedures and are designed for less invasive and 1-stage treatment of complex neurovascular lesions. METHODS: We retrospectively analyzed our experience in the treatment of complex neurovascular lesions in a hybrid OR. RESULTS: Three patients with distal middle cerebral artery (MCA) aneurysms underwent a proximal clip occlusion or endovascular trapping with a superficial temporal artery-MCA bypass after correct localization of the recipient branch distal to the aneurysm using superselective intra-arterial infusion of indocyanine green under an operating microscope. Two patients with innominate artery stenosis were treated with retrograde stenting from the common carotid artery (CCA) with distal protection of the internal carotid artery (ICA) alone, and with antegrade stenting with dual protection of the ipsilateral ICA and the vertebral artery. Two patients with tandem stenosis of the proximal CCA and carotid bifurcation underwent 1-stage retrograde stenting combined with a carotid endarterectomy. A patient with the innominate artery and the proximal CCA stenosis underwent staged percutaneous antegrade angioplasty of the innominate artery followed by retrograde stenting of both lesions. A patient with tandem stenosis of the subclavian and innominate arteries underwent 1-stage retrograde stenting. In 2 patients with carotid stenosis that was difficult to access via the endovascular route, carotid stenting was performed by direct puncture of the proximal CCA. No patients suffered from new postoperative neurologic deficits. CONCLUSIONS: The integration of a high-end hybrid OR enables combined endovascular and surgical procedures for complex neurovascular and brachiocephalic lesions in a 1-stage treatment.

Transplantation of telencephalic neural progenitors induced from embryonic stem cells into subacute phase of focal cerebral ischemia.

Cerebral ischemia causes neuronal death and disruption of neural circuits in the central nervous system. Various neurological disorders caused by cerebral infarction can severely impair quality of life and are potentially fatal. Functional recovery in the chronic stage mainly depends on physical treatment and rehabilitation. We aim to establish cell therapy for cerebral ischemia using embryonic stem (ES) cells, which have self-renewing and pluripotent capacities. We previously reported that the transplanted monkey and mouse ES cell-derived neural progenitors, by stromal cell-derived inducing activity method, could survive and differentiate into various types of neurons and glial cells, and form the neuronal network in basal ganglia. In this report, we induced the differentiation of the neural progenitors from mouse ES cells using the serum-free suspension culture method and confirmed the expression of various basal ganglial neuronal markers and neurotransmitter-related markers both in vitro and in vivo, which was thought to be suitable for replacing damaged striatum after middle cerebral artery occlusion. This is the first report that used selectively induced telencephalic neural progenitors into ischemia model. Furthermore, we purified the progenitors expressing the neural progenitor marker Sox1 by fluorescence-activated cell sorting and Sox1-positive neural progenitors prevented tumor formation in ischemic brain for 2 months. We also analyzed survival and differentiation of transplanted cells and functional recovery from ischemic damage.

Potential influence of sevelamer hydrochloride on responsiveness to erythropoiesis-stimulating agents in haemodialysis patients.

AIM: Vitamin D analogues, cinacalcet, and sevelamer play pivotal roles in the management of chronic kidney disease-mineral bone disorder, and are noted to have pleiotropic effects. We examined whether these agents might be associated with the responsiveness to erythropoiesis-stimulating agents (ESA). METHODS: In this cross-sectional study including haemodialysis patients treated with ESA, we searched for clinical parameters associated with the ESA resistance index, which was calculated as the weekly ESA dose divided by the patient's haemoglobin value. RESULTS: Among 45 patients (male: female = 28 : 17, age 68 ± 10 years, haemodialysis duration 84 ± 60 months), vitamin D analogue, cinacalcet, and sevelamer were used in 95.6%, 26.7%, and 84.4% of the patients, respectively. Univariate analysis showed significant association of the ESA resistance index with transferrin saturation rate (TSAT), vitamin D analogue dose, and sevelamer dose. In multivariate analysis, the sevelamer dose and TSAT were found to be independent determinants of the ESA resistance index. CONCLUSION: Our preliminary data showed an independent association between sevelamer dose and the responsiveness to ESA in haemodialysis patients. Further studies are required to investigate the causal relationship between sevelamer and ESA responsiveness.

Single and local blockade of interleukin-6 signaling promotes neuronal differentiation from transplanted embryonic stem cell-derived neural precursor cells.

Safe and efficient transplantation of embryonic stem (ES) cells to the brain requires that local inflammatory and immune responses to allogeneic grafts are inhibited. To investigate cytokines that affect graft cell survival and differentiation, we used stromal cell-derived inducing activity to induce the differentiation of neural progenitor cells (NPCs) from mouse ES cells and transplanted the NPCs into mouse brain. Examination of surrounding brain tissue revealed elevated expression levels of interleukin (IL)-1ß, IL-4, and IL-6 in response to NPC transplantation. Among these, only IL-6 reduced neuronal differentiation and promoted glial differentiation in vitro. When we added anti-IL-6 receptor antibodies to NPCs during transplantation, this single and local blockade of IL-6 signaling reduced the accumulation of host-derived leukocytes, including microglia. Furthermore, it also promoted neuronal differentiation and reduced glial differentiation from the grafted NPCs to an extent similar to that with systemic and continuous administration of cyclosporine A. These results suggest that local administration of anti-IL-6 receptor antibodies with NPCs may promote neuronal differentiation during the treatment of neurological diseases with cell replacement therapy.

Hypofractionated stereotactic radiotherapy for acoustic neuromas: safety and effectiveness over 8 years of experience.

BACKGROUND: Little information is available about long-term outcomes of hypofractionated stereotactic radiotherapy (hypo-FSRT) for acoustic neuromas. In this study, the safety and effectiveness of hypo-FSRT for unilateral acoustic neuroma were reviewed over 8 years of experience at our institution. METHODS: Between May 1998 and October 2006, 27 patients were consecutively treated by linear accelerator-based hypo-FSRT. Two patients were excluded from this study because they were lost to follow-up within 12 months. The median follow-up period for the rest was 59 (range 24-133) months. Two types of treatment schedules were adopted. Thirteen patients received 30-39 Gy, given in 10-13 fractions (regimen A), whereas after July 2003, 12 patients received 20-24 Gy, given in 5-6 fractions at the tumor periphery (regimen B). These treatments were scheduled to be delivered in three fractions per week (Monday, Wednesday, Friday). The median planning target volume was 2.0, with 1.7 ml (range 0.7-10.6) in regimen A and 5.2 ml (range 0.9-9.3) in regimen B. In the pretreatment audiogram, seven patients (two in regimen A and five in regimen B) had serviceable hearing (Gardner-Robertson Class I-II). RESULTS: Local control rates were 100% with regimen A and 92% with regimen B. Serviceable hearing was preserved in four of five patients in regimen B but no patients in regimen A at the last follow-up. No permanent facial or trigeminal nerve morbidity was observed following treatment, and no salvage surgery was needed. CONCLUSIONS: Hypo-FSRT for acoustic neuromas achieved a high local control rate with minimal facial and trigeminal nerve morbidity.

Minimization of exogenous signals in ES cell culture induces rostral hypothalamic differentiation.

Embryonic stem (ES) cells differentiate into neuroectodermal progenitors when cultured as floating aggregates in serum-free conditions. Here, we show that strict removal of exogenous patterning factors during early differentiation steps induces efficient generation of rostral hypothalamic-like progenitors (Rax(+)/Six3(+)/Vax1(+)) in mouse ES cell-derived neuroectodermal cells. The use of growth factor-free chemically defined medium is critical and even the presence of exogenous insulin, which is commonly used in cell culture, strongly inhibits the differentiation via the Akt-dependent pathway. The ES cell-derived Rax(+) progenitors generate Otp(+)/Brn2(+) neuronal precursors (characteristic of rostral-dorsal hypothalamic neurons) and subsequently magnocellular vasopressinergic neurons that efficiently release the hormone upon stimulation. Differentiation markers of rostral-ventral hypothalamic precursors and neurons are induced from ES cell-derived Rax(+) progenitors by treatment with Shh. Thus, in the absence of exogenous growth factors in medium, the ES cell-derived neuroectodermal cells spontaneously differentiate into rostral (particularly rostral-dorsal) hypothalamic-like progenitors, which generate characteristic hypothalamic neuroendocrine neurons in a stepwise fashion, as observed in vivo. These findings indicate that, instead of the addition of inductive signals, minimization of exogenous patterning signaling plays a key role in rostral hypothalamic specification of neural progenitors derived from pluripotent cells.

RBP-J promotes neuronal differentiation and inhibits oligodendroglial development in adult neurogenesis.

Neurogenesis persists in restricted regions of the adult vertebrate brain. However, the molecular mechanisms supporting adult neurogenesis are not fully understood. Here we demonstrated that C cell-specific deletion of RBP-J in the adult subventricular zones (SVZs) caused reduction in numbers of mature granule cells in the olfactory bulbs (OBs) with concomitant increase in Olig2(+) oligodendroglial progenitors, although generation of immature neurons was enhanced in the SVZs. Adenovirus-mediated Cre introduction to the SVZs of RBP-J-floxed mice indicated that Olig2(+) cells in the OBs can be generated from RBP-J-deficient SVZs, although no oligodendroglial cells in the OBs are derived from the normal SVZs. This preferential differentiation to oligodendroglial progenitor cells and reduction in differentiation of mature neurons were also confirmed by in vitro culture of RBP-J-deficient SVZ-derived neural progenitor cells, in addition to defects in the maintenance of adult neural stem cell population. The defects in maturation of RBP-J-deficient neurons could be partly rescued by knockdown of Olig2 in vivo. Our findings suggest that RBP-J might regulate neuronal maturation at least in part through transcriptional repression of Olig2.

Confirmation of an association of single-nucleotide polymorphism rs1333040 on 9p21 with familial and sporadic intracranial aneurysms in Japanese patients.

BACKGROUND AND PURPOSE: Genetic factors are important determinants of intracranial aneurysm (IA). Recently, a multinational, genome-wide association study identified 3 loci associated with IA, located on 2q (rs700651), 8q (rs10958409), and 9p (rs1333040 and rs10757278). The aim of this study was to evaluate these associations. METHODS: Familial and sporadic cases were investigated. Familial cases, consisting of 96 subjects with IA, and 46 subjects of unknown status from 31 pedigrees were analyzed with the transmission disequilibrium test and linkage analysis. Associations of single-nucleotide polymorphisms (SNPs) with IA were tested in 419 sporadic IA cases and in 408 control subjects. Sequencing of CDKN2A, CDKN2B, and CDKN2BAS revealed additional SNPs, and their associations with IA were also tested. RESULTS: The transmission disequilibrium test revealed associations of 2 SNPs, rs700651 (P=0.036) and rs1333040 (P=0.002), with familial IA. Analysis of SNPs in sporadic cases revealed an allelic association of rs1333040 with IA (odds ratio=1.28; 95% CI, 1.04-1.57; P=0.02) but failed to show associations of rs10757278 and rs496892 with IA. We sequenced 3 candidate genes; CDKN2A, CDKN2B, and CDKN2BAS. All 6 index cases from IA families had the rs1333040-T allele and SNPs (rs10965215, rs10120688, and rs7341791) in CDKN2BAS. None of these SNPs had linkage disequilibrium with rs1333040 and was associated with IA. CONCLUSIONS: A region between introns 7 and 15 of CDKN2BAS carrying the rs1333040-T allele may confer risk for IA.

Matrigel supports survival and neuronal differentiation of grafted embryonic stem cell-derived neural precursor cells.

Cell replacement therapy holds great promise as a means of treating neurological disorders, including Parkinson's disease. However, one of the major obstacles to the success of this treatment is the low survival rate of grafted cells, which probably results from mechanical damage, acute inflammation, and immunological rejection. To overcome this problem, we investigated the effect of different types of extracellular matrix (ECM) on the survival and differentiation of embryonic stem (ES) cell-derived neural precursor cells (NPCs). We tested materials from natural sources, including collagen, ornithine/laminin, and growth factor-reduced Matrigel (gfrMG), as well as the synthetic biomaterial PuraMatrix, which consists of self-assembling polypeptides. GfrMG efficiently supported cell survival, migration, and neurite outgrowth in vitro and promoted proliferation of grafted cells in vivo, resulting in larger graft volume and an increase in the number of TH-positive dopaminergic neurons in the graft. GfrMG did not induce dopaminergic differentiation directly; rather, it reduced the invasion of pan-leukocytic CD45-positive cells into the graft. Insofar as the inflammatory or immune response in the host brain inhibits neuronal differentiation of grafted NPCs, gfrMG may increase the number of TH-positive cells by suppressing this effect. Thus, gfrMG appears to provide a suitable scaffold that supports survival and differentiation of NPCs. However, because it is derived from mouse sarcomas, a human-derived matrix or synthetic biomaterial must be developed for clinical applications.

Practical decision-making in the treatment of unruptured cerebral aneurysm in Japan: the U-CARE study.

BACKGROUND: Decision-making during the management of unruptured cerebral aneurysms is a delicate process for both neurosurgeons and patients. Guidelines are evidence-based references that can aid in making decisions. However, neurosurgeons do not always follow guidelines in clinical practice. The purpose of this study is to verify the hypothesis that there is substantial dissociation between treatment guidelines and practical decision-making due to a bias in treatment selection for unruptured cerebral aneurysms. This bias is dependent upon clinician-driven factors such as experience and specialty, and patient-driven factors such as patient preference. METHODS: This study was performed using internet questionnaires. A total of 282 randomly selected, qualified Japanese neurosurgeons (out of approx. 6,000 registered neurosurgeons), including 45 endovascular specialists, participated in this study. Radiological and demographic data from 88 cases of unruptured cerebral aneurysm were opened on the Web. Participating neurosurgeons decided on the treatment for each case (clipping, coiling or observation). RESULTS: Variations in treatment selection were not significant between neurosurgeons and endovascular specialists, except for aneurysms such as anterior choroidal artery aneurysm. However, contrary to the guidelines, aneurysms larger than 10 mm tended to be treated conservatively because the risk of treatment is high, while aneurysms smaller than 5 mm in diameter were often selected for intervention (clipping or coiling). CONCLUSIONS: This study revealed that in real-world clinical practice, physicians are not always faithful to the current guidelines. In making practical treatment decisions for unruptured cerebral aneurysms, the patient's will and the recognition of unavoidable, treatment-related risks seriously influence neurosurgeons' decisions.

Reduced collagen biosynthesis is the hallmark of cerebral aneurysm: contribution of interleukin-1beta and nuclear factor-kappaB.

BACKGROUND: Reduced extracellular matrix is a prominent feature of cerebral aneurysms (CAs). We previously reported excessive ECM degradation in CA walls. In the present study, we examined collagen biosynthesis in CA walls and the molecular mechanisms underlying it in CA progression. METHODS AND RESULTS: RT-PCR and immunohistochemistry showed reduced expression of procollagen type I, III, and lysyl oxidase (LOX) in CA walls. Treatment with the LOX inhibitor beta-aminopropionitrile resulted in enhanced progression of CA. Expression of procollagen type I, III, and LOX was inhibited by interleukin-1beta (IL-1beta) in cultured rat aortic smooth muscle cells (RASMCs) in vitro. Nuclear factor kappa-B (NF-kappaB) was activated in IL-1beta-stimulated RASMCs, and treatment with NF-kappaB decoy oligodeoxynucleotides (ODN) restored reduced expression of procollagen type I, III, and LOX in vitro. NF-kappaB decoy ODNs ameliorated the expression of procollagen type I, III, and LOX in CA walls in vivo. CONCLUSIONS: Collagen biosynthesis was significantly inhibited at the transcriptional level and in the posttranscriptional enzymatic modification in CA walls through upregulated expression of IL-1beta and the NF-kappaB pathway. Reduced collagen biosynthesis may contribute to CA progression, and inhibition of this process may lead to the prevention of the progression and rupture of CAs.

Improved cerebral function in mesial temporal lobe epilepsy after subtemporal amygdalohippocampectomy.

The functional changes that occur throughout the human brain after the selective removal of an epileptogenic lesion remain unclear. Subtemporal selective amygdalohippocampectomy (SAH) has been advocated as a minimally invasive surgical procedure for patients with medically intractable mesial temporal lobe epilepsy (MTLE). We evaluated the effects of subtemporal SAH on cerebral glucose metabolism and memory function in 15 patients with medically intractable MTLE with hippocampal sclerosis using [(18)F]-fluorodeoxyglucose PET (FDG-PET) and the Wechsler Memory Scale-Revised. The patients were evaluated before and 1-5 years (mean 2.6 years) after surgery. In patients with MTLE of the language-dominant hemisphere, the basal temporal language area was preserved by this surgical approach. Voxel-wise comparison of FDG-PET images was conducted using SPM5 to identify the brain regions showing postoperative changes in glucose metabolism (height threshold, P = 0.01 corrected for multiple comparisons; extent threshold, 100 voxels). During spatial normalization of the postoperative FDG-PET images, we used cost-function masking to minimize any inappropriate image distortion as a result of the abnormal signal within the surgically resected region. Postoperative glucose metabolism increased in extratemporal areas ipsilateral to the affected side, such as the dorsolateral prefrontal cortex, and the dorsomedial and ventromedial frontal cortices. Glucose metabolism also increased in the bilateral inferior parietal lobules and in the remaining temporal lobe regions remote from the resected mesial temporal region, such as the superior temporal gyrus and the temporal pole. By contrast, postoperative glucose metabolism decreased only in the mesial temporal area adjacent to the resected region. Postoperative verbal memory, delayed recall and attention/concentration scores were significantly better than preoperative scores regardless of the resected side. This study suggests that the selective removal of the epileptogenic region in MTLE using a subtemporal approach improved cerebral glucose metabolism in the areas receiving projections from the affected mesial temporal lobe. Cognitive improvement might result from a combination of good seizure control and minimizing the regions of the brain with postoperative functional impairment.

Impact of monocyte chemoattractant protein-1 deficiency on cerebral aneurysm formation.

BACKGROUND AND PURPOSE: Recent studies have suggested that chronic inflammation actively participates in cerebral aneurysm (CA) formation. Macrophages accumulate in CA walls and express proinflammatory genes promoting CA progression, but the molecular mechanisms of monocyte/macrophage recruitment into CA walls remain to be elucidated. METHODS: Monocyte chemoattractant protein-1 (MCP-1) expression in experimentally induced CAs was assessed by immunohistochemistry and Western blotting. The role of MCP-1 in CA formation was examined by MCP-1(-/-) mice and a plasmid DNA encoding a dominant negative mutant of MCP-1 (7ND). MCP-1 expression in human CAs was examined by immunohistochemistry. RESULTS: MCP-1 expression was upregulated in aneurysmal walls at the early stage of CA formation. MCP-1(-/-) mice exhibited a significant decrease of CA formation and macrophage accumulation with decreased expression of matrix metalloproteinase-2, -9, and inducible nitric oxide synthase. Immunohistochemistry for the DNA binding form of nuclear factor-kappa B showed nuclear factor-kappa B activation in MCP-1-expressing cells. Blockade of MCP-1 activity by 7ND resulted in the inhibition of CA progression in rats. In human CAs, MCP-1 was also expressed in CA walls. CONCLUSIONS: These data suggest that MCP-1 plays a crucial role in CA formation as a major chemoattractant for monocyte/macrophage. MCP-1 expression in CA walls is induced through nuclear factor-kappa B activation. MCP-1 may be a novel therapeutic target of medical treatment preventing CA progression.

Reactive oxygen species modulate growth of cerebral aneurysms: a study using the free radical scavenger edaravone and p47phox(-/-) mice.

Cerebral aneurysm (CA) is a relatively common disease and can cause a catastrophic subarachnoid hemorrhage with a high mortality and morbidity rate. Despite its clinical and social importance, the detailed mechanism of CA formation remains to be elucidated, resulting in the absence of effective medical treatment against CAs. Recent studies revealed that chronic inflammation in arterial walls by hemodynamic force is implicated in CA formation. Reactive oxygen species (ROS) are a major mediator of inflammation and actively participate in the pathogenesis of various vascular diseases. In the present study, we first assessed the expression of ROS-producing and -eliminating genes in CA walls by immunohistochemistry and RT-PCR analysis. The ROS-producing gene, p47phox, was upregulated in infiltrating macrophages and medial smooth muscle cells in arterial walls. Upregulated ROS-producing genes and suppressed ROS-eliminating genes suggested that ROS overproduction occurred in aneurysmal walls. In situ superoxide imaging by dihydroethidium, which showed ROS overproduction in aneurysmal walls, confirmed this hypothesis. Edaravone, a powerful free radical scavenger, effectively inhibited CA formation by suppressing inflammation-related gene expression in aneurysmal walls. Furthermore, CA formation was markedly inhibited by p47phox deletion in mice and was accompanied by decreased inflammation in aneurysmal walls. These data suggested the active participation of ROS and p47phox in CA formation and the therapeutic potential of an ROS-eliminating agent against CA formation.