[A Rare Case of Ruptured/Unruptured Miniature Aneurysms Originating from the Infundibular Dilatation of the Callosomarginal Artery, Branching from the Infracallosal(A2)Segment of the Azygos Anterior Cerebral Artery].

We report the first case of two de novo miniature aneurysms(ruptured/unruptured)emerging from the infundibular dilatation(ID)of the callosomarginal artery, which branches from the infracallosal(A2)segment of the azygos anterior cerebral artery(AACA), in a 36-year-old woman. The patient had previously been diagnosed with a miniature, unruptured aneurysm, occurring in the A2 segment of the AACA, detected by CT angiography(CTA)at another hospital two years ago, and had been followed up with MR angiography(MRA)every 6 months. Three months after the final check-up with MRA, which did not indicate a significant change in the aneurysm, the patient presented with subarachnoid hemorrhage. Subsequent CTA and digital subtraction angiograms revealed that the right callosomarginal artery, originating from the apex of the aneurysmal bulge, had a maximal diameter of 3mm, indicating an ID of the artery. Additionally, two miniature bleb-like aneurysms emerged from the ID, projecting in opposite directions:one projecting to the right-posterior/superior direction and the other to the left-anterior/inferior direction. Both aneurysms were successfully clipped via a right pterional approach with partial resection of the gyrus rectus, and the right-projecting aneurysm was confirmed to be ruptured during surgery. In the current report, we review previously reported cases of AACA with aneurysms, and discuss their clinical characteristics, and the possible mechanisms underlying the formation of the ID and de novo aneurysms in this extremely rare case.

[A Rare Case of Ruptured Internal Carotid-Posterior Communicating Artery Aneurysm Associated with Contralateral Delayed Oculomotor Nerve Palsy].

A 55-year-old man presented with difficulty breathing, chest pain, and disturbance of consciousness, and was transferred to our hospital. Initial whole body CT revealed a diffuse subarachnoid hemorrhage(SAH)with severe pulmonary edema that was considered neurogenic in origin. He received controlled ventilation under sedation and conservative care for the SAH. One day after the onset of the SAH, his left pupil suddenly became dilated to 6mm, with no reaction to light. Head CT showed no new bleeding. Subsequent CT angiogram revealed a right internal carotid-posterior communicating artery aneurysm(IC-PC AN)with a posterior-lateral projection; however, no vessel abnormality was observed in the left anterior or posterior circulations. The aneurysm was successfully treated with coil embolization. We reviewed reported cases of isolated oculomotor nerve palsy(ONP), without direct compression by ruptured aneurysms, and found that only 11 cases exist, including our case. Interestingly, six of them were associated with anterior communicating artery aneurysms. A mass effect, chemical stimulation, and a jet stream of blood were proposed as the mechanisms of this rare type of ONP, in addition to the specific neurovascular relationships between the oculomotor nerve and the posterior cerebral/posterior communicating/superior cerebellar arteries, with abnormal nerve contact or compression. Though rare, ruptured IC-PC ANs could cause contralateral ONP; other types of ruptured aneurysms may also lead to indirect effects on nervous structures without direct compression. This type of rare presentation of ruptured aneurysms should be considered, especially in cases of multiple aneurysms, such as IC-PC ANs.

18F-FDG PET/CT Volumetric Parameters are Associated with Tumor Grade and Metastasis in Pancreatic Neuroendocrine Tumors in von Hippel-Lindau Disease.

BACKGROUND: Approximately 8-17 % of patients with von Hippel-Lindau (VHL) syndrome develop pancreatic neuroendocrine tumors (PNETs), with 11-20 % developing metastases. Tumor grade is predictive of prognosis. OBJECTIVE: The aim of this study was to determine if preoperative metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were associated with metastatic disease and tumor grade. METHODS: Sixty-two patients with VHL-associated PNETs prospectively underwent 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT). MTV, TLG, and maximum standardized uptake value (SUVmax) were measured using a semi-automatic method. Surgically resected PNETs were classified according to 2010 World Health Organization tumor grade classification. MTV, TLG, and SUVmax were analyzed by metastatic disease and tumor grade using the Mann-Whitney test. RESULTS: A total of 88 PNETs were identified by CT and 18F-FDG PET/CT, 10 of which were non-FDG-avid. Histologic grading was available for 20 surgical patients. Patients with metastatic PNETs had a higher TLG (median 25.9 vs. 7.7 mean SUV [SUVmean]*mL; p = 0.0092) compared with patients without metastasis, while patients with grade 2 PNETs had a higher MTV (median 6.9 vs. 2.6 mL; p = 0.034) and TLG (median 41.2 vs. 13.1 SUVmean*mL; p = 0.0035) compared with patients with grade 1 PNETs. No difference in tumor size or SUVmax was observed between the groups. CONCLUSIONS: Patients with metastatic PNETs have a higher TLG compared with patients without metastasis. Grade 2 PNETs have a higher MTV and TLG compared with grade 1 PNETs. Tumor size and SUVmax were not associated with grade. Volumetric parameters on 18F-FDG PET/CT may be useful in detecting higher grade PNETs with a higher malignant potential that may need surgical intervention.

Whole Body Metabolic Tumor Volume and Total Lesion Glycolysis Predict Survival in Patients with Adrenocortical Carcinoma.

BACKGROUND: Adrenocortical carcinoma (ACC) is a rare but lethal malignancy with few reliable prognostic markers. FDG-PET metabolic parameters have been shown to predict survival in several cancers. The objective was to determine if metabolic tumor volume (MTV), total lesion glycolysis (TLG), and maximum standardized uptake value (SUVmax) could serve as prognostic markers in patients with ACC. METHODS: A total of 30 patients with ACC prospectively underwent 18F-FDG PET/CT prior to treatment. Whole body MTV, TLG, and SUVmax were measured by a semiautomatic method. A median cutoff was used to determine an association with overall survival (OS) from the time of 18F-FDG PET/CT by the Kaplan-Meier method. RESULTS: Patients with high whole body MTV (>87.0 mL),TLG (>229.4 SUVlbm*mL), or SUVmax (>8.9 SUV) had a worse OS compared with those with low whole body MTV (median OS, 24 vs 45.1 months, p < .01), TLG (median OS, 24 vs 40.3 months, p < .005), or SUVmax (median OS, 23.7 vs 35.5 months, p < .02). In patients who had operable disease (n = 23), high whole body MTV (>87.0 mL) and TLG (>229.4 SUVlbm*mL) had a worse OS compared with those with low whole body MTV (median OS, 25.1 vs 45.1 months, p < .05) and TLG (median OS, 25.1 vs 40.3 months, p < .05), but a high SUVmax (>8.9 SUV) was not associated with worse OS (p = .11). CONCLUSIONS: Patients with ACC and a high whole body MTV, TLG, and SUVmax have a worse prognosis and OS. Measurement of whole body MTV and TLG may be helpful for guiding therapy for patients with ACC.

Novel role for molecular transporter importin 9 in posttranscriptional regulation of IFN-ε expression.

IFN-ε is a unique type I IFN whose constitutive expression in lung, brain, small intestine, and reproductive tissues is only partially understood. Our previous observation that posttranscriptional events participate in the regulation of IFN-ε mRNA expression led us to investigate whether the 5' and/or 3' untranslated regions (UTR) have regulatory functions. Surprisingly, we found that full-length IFN-ε 5'UTR markedly suppressed mRNA expression under basal conditions. Analysis of the secondary structure of this region predicted formation of two stable stem-loop structures, loops 1 and 2. Studies using luciferase constructs harboring various stretches of IFN-ε 5'UTR and mutant constructs in which the conformation of loop structures was disrupted showed that loop 1 is essential for regulation of mRNA expression. Incubation of HeLa cell extracts with agarose-bound RNAs harboring IFN-ε loop structures identified importin 9 (IPO9), a molecular transporter and chaperone, as a candidate that associates with these regions of the 5'UTR. IPO9 overexpression decreased, and IPO9 silencing increased basal IFN-ε expression. Our studies uncover a previously undescribed function for IPO9 as a specific, and negative, posttranscriptional regulator of IFN-ε expression, and they identify key roles for IFN-ε stem-loop structure 1 in this process. IPO9-mediated effects on 5'UTRs appear to extend to additional mRNAs, including hypoxia-inducible factor-1α, that can form specific loop structures.

Identification of chromosome 3q28 and ALPK1 as susceptibility loci for chronic kidney disease in Japanese individuals by a genome-wide association study.

BACKGROUND: Although genome-wide association studies (GWASs) have implicated several genes in the predisposition to chronic kidney disease (CKD) in Caucasian or African American populations, the genes that confer susceptibility to CKD in Asian populations remain to be identified definitively. We performed a GWAS to identify genetic variants that confer susceptibility to CKD in Japanese individuals. METHODS: 3851 Japanese individuals from three independent subject panels were examined. Subject panels A, B, and C comprised 252, 910, and 190 individuals with CKD and 249, 838, and 1412 controls, respectively. A GWAS for CKD was performed in subject panel A. RESULTS: Five single nucleotide polymorphisms (SNPs) at chromosome 3q28, ALPK1, FAM78B, and UMODL1 were significantly (false discovery rate<0.05) associated with CKD by the GWAS. The relation of these five SNPs and of an additional 22 SNPs at these loci to CKD was examined in subject panel B, revealing that rs9846911 at 3q28 was significantly associated with CKD in all individuals and that rs2074381 and rs2074380 in ALPK1 were associated with CKD in individuals with diabetes mellitus. These three SNPs were further examined in subject panel C, revealing that rs2074381 and rs2074380 were significantly associated with CKD. For subject panels B and C combined, rs9846911 was significantly associated with CKD in all individuals and rs2074381 and rs2074380 were associated with CKD in diabetic individuals. CONCLUSIONS: Chromosome 3q28 may be a susceptibility locus for CKD in Japanese individuals, and ALPK1 may be a susceptibility gene for CKD in such individuals with diabetes mellitus.

High expression of KIBRA in low atypical protein kinase C-expressing gastric cancer correlates with lymphatic invasion and poor prognosis.

Overexpression of atypical protein kinase Cλ/ι (aPKCλ/ι), a regulator of cell polarity, is frequently associated with the poor prognoses of several cancers, including gastric cancer. Recent studies revealed a molecular link between aPKC and KIBRA, an upstream regulator of tumor suppressor Hippo pathway that regulates cell proliferation and apoptosis. Further, KIBRA directly inhibits the kinase activity of aPKC to regulate epithelial cell polarity. These observations suggest that the KIBRA-aPKC connection plays a role in cancer progression; however, clinical significance of the correlation between these factors remains unclear. Here we examined the correlation between KIBRA/aPKCλ/ι expression, as detected by immunohistochemistry, and clinicopathological outcomes in 164 gastric cancer patients using Fisher's exact test and Kaplan-Meier log-rank test. We found an intimate correlation between the expression level of KIBRA and aPKCλ/ι (P = 0.012). Furthermore, high expression of KIBRA is correlated with lymphatic (P = 0.046) and venous invasion (P = 0.039). The expression level of KIBRA by itself did not correlate with the prognosis; however, high expression of KIBRA in low aPKCλ/ι-expressing gastric cancer correlated with disease-specific (P = 0.037) and relapse-free survival (P = 0.041) by Kaplan-Meier with log-rank test and higher lymphatic invasion cases by Fisher's exact test (P = 0.042). Furthermore, overexpression of the aPKC-binding region of KIBRA disrupted tight junctions in epithelial cells. These results suggest that high expression of KIBRA in low aPKC-expressing cells causes massive loss of aPKC activity, leading to loss of polarity and invasiveness of gastric cancer cells.

Double-stranded RNA induces biphasic STAT1 phosphorylation by both type I interferon (IFN)-dependent and type I IFN-independent pathways.

Upon viral infection, pattern recognition receptors sense viral nucleic acids, leading to the production of type I interferons (IFNs), which initiate antiviral activities. Type I IFNs bind to their cognate receptor, IFNAR, resulting in the activation of signal-transducing activators of transcription 1 (STAT1). Thus, it has long been thought that double-stranded RNA (dsRNA)-induced STAT1 phosphorylation is mediated by the transactivation of type I IFN signaling. Foreign RNA, such as viral RNA, in cells is sensed by the cytoplasmic sensors retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA-5). In this study, we explored the molecular mechanism responsible for STAT1 phosphorylation in response to the sensing of dsRNA by cytosolic RNA sensors. Polyinosinic-poly(C) [poly(I:C)], a synthetic dsRNA that is sensed by both RIG-I and MDA-5, induces STAT1 phosphorylation. We found that the poly(I:C)-induced initial phosphorylation of STAT1 is dependent on the RIG-I pathway and that MDA-5 is not involved in STAT1 phosphorylation. Furthermore, pretreatment of the cells with neutralizing antibody targeting the IFN receptor suppressed the initial STAT1 phosphorylation in response to poly(I:C), suggesting that this initial phosphorylation event is predominantly type I IFN dependent. In contrast, neither the known RIG-I pathway nor type I IFN is involved in the late phosphorylation of STAT1. In addition, poly(I:C) stimulated STAT1 phosphorylation in type I IFN receptor-deficient U5A cells with delayed kinetics. Collectively, our study provides evidence of a comprehensive regulatory mechanism in which dsRNA induces STAT1 phosphorylation, indicating the importance of STAT1 in maintaining very tight regulation of the innate immune system.

Glomerular expression of fractalkine is induced by polyinosinic-polycytidylic acid in human mesangial cells: possible involvement of fractalkine after viral infection.

BACKGROUND: Viral infections often trigger the onset or worsening of glomerular diseases, but the details of this mechanism are unclear. Fractalkine/CX3CL1 (Fkn) is a chemokine that induces the chemotaxis and activation of cells expressing its receptor, CX3CR1. To examine the involvement of glomerular Fkn expression in the development of glomerulonephritis after viral infection, we conducted experimental studies using human mesangial cells (MCs) in culture. METHODS: We examined the effect of polyinosinic-polycytidylic acid (poly IC), an authentic viral double-stranded RNA, on Fkn expression in MCs to investigate the involvement of Fkn in the antiviral reaction of MCs. Fkn mRNA and protein were analyzed using real-time PCR and enzyme-linked immunosorbent assay. Also, an immunofluorescent study to examine mesangial Fkn expression in biopsy specimens obtained from patients with glomerulonephritis was conducted. RESULTS: Poly IC-induced Fkn expression in MCs in both a time- and dose-dependent manner, and RNA interference (RNAi) against Toll-like receptor 3 (TLR3) or interferon regulatory factor 3 (IRF3) inhibited poly IC-induced Fkn expression. Significant glomerular Fkn expression was observed in biopsy specimens from patients with immunoglobulin A nephropathy and purpura nephritis, with increasing severity of glomerular inflammation. CONCLUSION: The TLR3/IRF3/Fkn signaling pathway may, at least in part, mediate immune and inflammatory responses against viral infection in MCs.

Effects of Brazilian green propolis on double-stranded RNA-mediated induction of interferon-inducible gene and inhibition of recruitment of polymorphonuclear cells.

BACKGROUND: Propolis is a bee product with various biological properties, including an antiviral activity when taken orally. However, its mechanisms at the cellular and molecular level are not well understood. RESULTS: We investigated the effect of propolis on antiviral signaling in A549 cells transfected with double-stranded RNA (dsRNA), a model for viral infection. Pretreatment of the cells with propolis inhibited poly I:C (synthetic dsRNA)-induced interferon (IFN)-ß expression. Propolis had no effect on the dsRNA-induced expression of RIG-I-like receptors (RLRs), which are known as intracellular viral RNA sensors. As to the effect on antiviral executor genes, propolis enhanced myxovirus resistance 1 (MX1) expression, whereas interferon-inducible gene 6-16 (G1P3) and 2'-5'-oligoadenylate synthetase (OAS) were unaffected. All of these genes belong to the IFN-inducible genes, suggesting that the effect of propolis on antiviral signaling is not necessarily mediated by the autocrine regulation by IFN-ß. Propolis pretreatment inhibited dsRNA-induced interleukin-8 (IL8) and CCL5 expression, and consequently lowered polymorphonuclear leukocyte (PMN) chemotactic activity in the cell-conditioned medium. CONCLUSION: Taken together, these results suggest that propolis may suppress excess inflammatory responses without affecting the innate immunity during viral infection.

Characterization of synergistic induction of CX3CL1/fractalkine by TNF-alpha and IFN-gamma in vascular endothelial cells: an essential role for TNF-alpha in post-transcriptional regulation of CX3CL1.

CX3CL1/fractalkine, a chemokine specific to monocytes and NK cells, is induced synergistically by TNF-alpha and IFN-gamma in vascular endothelial cells. However, the mechanism for this synergism remains unclear. This study explored the hypothesis that the CX3CL1 expression is regulated at a posttranscriptional level, which may responsible for the synergism between TNF-alpha and IFN-gamma. Brief exposure of HUVECs to TNF-alpha led to a robust increase in IFN-gamma-induced CX3CL1 production. We found that TNF-alpha stabilized CX3CL1 mRNA in HUVECs stimulated with IFN-gamma. Cloning of 3' untranslated region (UTR) of CX3CL1 mRNA revealed the presence of a single copy of nonametric AU-rich element in its 3'UTR, and a luciferase reporter assay showed that a single AU-rich element is a crucial cis-element in the posttranscriptional regulation of CX3CL1. TNF-alpha treatment resulted in the phosphorylation of p38 MAPK and its downstream target, MAPK-activated protein kinase-2, but IFN-gamma did not affect the levels of MAPK and MAPK-activated protein kinase-2 phosphorylation induced by TNF-alpha. Treatment of the cells with an inhibitor of p38 MAPK accelerated the decay of CX3CL1 mRNA induced by TNF-alpha or the combination of TNF-alpha and IFN-gamma. Immunoprecipitation assay revealed that mRNA stabilizer HuR directly binds to 3'UTR of CX3CL1 mRNA. CX3CL1 expression is under control of posttranscriptional regulation, which is involved in the synergistic induction of CX3CL1 in response to the combined stimulation with TNF-alpha and IFN-gamma.

Association of a genetic variant of BTN2A1 with metabolic syndrome in East Asian populations.

BACKGROUND: The authors previously showed that the C→T polymorphism (rs6929846) of butyrophilin, subfamily 2, member A1 gene (BTN2A1) was significantly associated with myocardial infarction in Japanese individuals. Given that metabolic syndrome (MetS) is an important risk factor for myocardial infarction, the association of the rs6929846 of BTN2A1 with myocardial infarction might be attributable, at least in part, to its effect on susceptibility to MetS. AIM: The aim of the present study was to examine the relation of the rs6929846 of BTN2A1 to MetS in East Asian populations. METHODS: The study population comprised 5210 Japanese or Korean individuals (3982 individuals with MetS, 1228 controls) from three independent subject panels. Japanese subject panels A and B comprised 1322 individuals with MetS and 654 controls, and 1909 individuals with MetS and 170 controls, respectively, whereas the Korean population samples comprised 751 individuals with MetS and 404 controls. RESULTS: Comparison of genotype distributions using the χ(2) test revealed that the genotype distributions and allele frequencies of rs6929846 were significantly (p<0.05) associated with MetS in Japanese subject panels A (T allele frequency: MetS, 0.091; controls, 0.054; p=6.1×10(-5)) and B (T allele frequency: MetS, 0.091; controls, 0.039; p=0013) but not in the Korean population samples (T allele frequency: MetS, 0.102; controls, 0.125; p=0.0997). Multivariable logistic regression analysis with adjustment for covariates revealed that the rs6929846 of BTN2A1 was significantly (p<0.017) associated with MetS in Japanese subject panel A (p=0.0055, OR 1.97) and in all individuals (p=0.0038, OR 1.38), with the T allele representing a risk factor for this condition. CONCLUSION: BTN2A1 may be a susceptible gene for MetS in Japanese individuals.

Melanoma differentiation-associated gene 5 regulates the expression of a chemokine CXCL10 in human mesangial cells: implications for chronic inflammatory renal diseases.

Mesangial cells play an important role in inflammatory reactions in kidney. Although viral infections often trigger the worsening of chronic inflammatory renal diseases, the mechanisms are largely unknown. Melanoma differentiation-associated gene 5 (MDA5) is a member of RNA helicase family with a conserved Asp-Glu-x-His (DExH) box. In the present study, we examined the effect of polyinosinic-polycytidylic acid (poly IC), an authentic double-stranded RNA (dsRNA) that mimics viral dsRNAs, on MDA5 expression using primary culture of human mesangial cells. The cells were simply treated or transfected with poly IC; the former procedure is a model of cells exposed to viral dsRNA released from dying cells, and the latter is a model of entry of RNA virus into the cytoplasm. Expression levels of MDA5 mRNA in mesangial cells were increased about 70-100 fold in response to either treatment or transfection with poly IC. MDA5 protein expression was significantly induced as well. RNA interference experiments revealed that poly IC treatment induced MDA5 expression via Toll-like receptor 3 (TLR3) and interferon (IFN)-ß, and that poly IC trasnfection induced MDA5 expression via another DExH box RNA helicase, retinoic acid-inducible gene-I (RIG-I), and IFN-ß. Moreover, MDA5 induced by poly IC, in turn, increased the expression of a chemokine CXCL10. In addition, immunohistochemical staining demonstrated a high level of MDA5 expression in glomeruli, mainly in mesangial cells, of patients with severe lupus nephritis or proteinuric IgA nephropathy. MDA5 may be involved not only in physiological antiviral reactions but also in chronic inflammation in glomerular mesangial cells.

Generation of viable male and female mice from two fathers.

In sexual species, fertilization of oocytes produces individuals with alleles derived from both parents. Here we use pluripotent stem cells derived from somatic cells to combine the haploid genomes from two males to produce viable sons and daughters. Male (XY) mouse induced pluripotent stem cells (Father #1) were used to isolate subclones that had spontaneously lost the Y chromosome to become genetically female (XO). These male-derived XO stem cells were used to generate female chimeras that were bred with genetically distinct males (Father #2), yielding progeny possessing genetic information that was equally derived from both fathers. Thus, functional oocytes can be generated from male somatic cells after reprogramming and spontaneous sex reversal. These findings have novel implications for mammalian reproduction and assisted reproductive technology.

Polyinosinic-polycytidylic acid induces the expression of interferon-stimulated gene 20 in mesangial cells.

BACKGROUND/AIMS: Interferon (IFN)-stimulated gene 20 (ISG20) is a 3'-to-5' exonuclease specific for single-stranded RNA and involved in host defense reactions against RNA viruses. The expression and the role of ISG20 in mesangial cells have not been reported. METHODS: Normal human mesangial cells were cultured and treated with polyinosinic-polycytidylic acid (poly (I:C)), an authentic double-stranded RNA which mimics viral infection to cells. The effect of RNA interference of Toll-like receptor 3 (TLR3) or IFN-ß on the ISG20 expression was examined. The effect of a blocking antibody against the receptor for IFN-ß or anti-inflammatory steroid dexamethasone was also examined. RESULTS: Treatment of cells with poly (I:C) induced the expression of ISG20. The poly (I:C)-induced expression of ISG20 was inhibited by knockdown of TLR3, IFN regulatery factor 3 (IRF3) or IFN-ß. Blocking of the receptor for IFN-ß suppressed and overexpression of IFN-ß enhanced ISG20 expression. The poly (I:C)-induced expressions of IFN-ß and ISG20 were inhibited by dexamethasone. Transfection of mesangial cells with poly (I:C) or 5'-triphosphate single-stranded RNA as a complex with cationic lipid also induced the expression of ISG20, and this was inhibited by knockdown of retinoic acid-inducible gene-I (RIG-I). CONCLUSION: Poly (I:C) induces the expression of ISG20 in mesangial cells. ISG20 may be involved in anti-viral reactions in renal mesangial cells. TLR3, IRF3 and de novo synthesized IFN-ß may mediate the poly (I:C)-induced expression of ISG20, and RIG-I may mediate ISG20 expression induced by poly (I:C)/cationic lipid complex.

The levels of retinoic acid-inducible gene I are regulated by heat shock protein 90-alpha.

Retinoic acid-inducible gene I (RIG-I) is an intracellular pattern recognition receptor that plays important roles during innate immune responses to viral dsRNAs. The mechanisms and signaling molecules that participate in the downstream events that follow activation of RIG-I are incompletely characterized. In addition, the factors that define intracellular availability of RIG-I and determine its steady-state levels are only partially understood but are likely to play a major role during innate immune responses. It was recently reported that the antiviral activity of RIG-I is negatively regulated by specific E3 ubiquitin ligases, suggesting participation of the proteasome in the regulation of RIG-I levels. In this study, we used immunoprecipitation combined with mass spectrometry to identify RIG-I-interacting proteins and found that RIG-I forms part of a protein complex that includes heat shock protein 90-alpha (HSP90-alpha), a molecular chaperone. Biochemical studies using purified systems demonstrated that the association between RIG-I and HSP90-alpha is direct but does not involve participation of the CARD domain. Inhibition of HSP90 activity leads to the dissociation of the RIG-I-HSP90 complex, followed by ubiquitination and proteasomal degradation of RIG-I. In contrast, the levels of RIG-I mRNA are unaffected. Our studies also show that the ability of RIG-I to respond to stimulation with polyinosinic:polycytidylic acid is abolished when its interaction with HSP90 is inhibited. These novel findings point to HSP90-alpha as a chaperone that shields RIG-I from proteasomal degradation and modulates its activity. These studies identify a new mechanism whose dysregulation may seriously compromise innate antiviral responses in mammals.

Association of a genetic variant of BTN2A1 with chronic kidney disease in Japanese individuals.

AIM: Although recent genetic studies suggested that several genetic variants increase the risk for chronic kidney disease (CKD), the genes that underlie genetic susceptibility to this condition remain to be identified definitively. We showed that the C→T polymorphism (rs6929846) of BTN2A1 and A→G polymorphism (rs2569512) of ILF3 were significantly associated with myocardial infarction in Japanese individuals by a genome-wide association study. The purpose of the present study was to examine a possible association of these polymorphisms (rs6929846, rs2569512) with CKD in Japanese individuals. METHODS: A total of 7542 Japanese individuals from two independent populations were examined: Subject panel A comprised 971 individuals with CKD (estimated glomerular filtration rate (eGFR) <60 mL/min 1.73 m(-2)) ) and 2269 controls (eGFR ≥60 mL/min 1.73 m(-2) ); and subject panel B comprised 1318 individuals with CKD and 2984 controls. RESULTS: The χ(2) test revealed that rs6929846 of BTN2A1, but not rs2569512 of ILF3, was significantly related to the prevalence of CKD both in subject panels A (P = 0.0383) and B (P = 0.0477). Multivariable logistic regression analysis with adjustment for covariates revealed that the C→T polymorphism (rs6929846) of BTN2A1 was significantly associated with the prevalence of CKD in subject panels A (P = 0.0422; recessive model; odds ratio, 2.36) and B (P = 0.0386; dominant model; odds ratio, 1.21) with the T allele representing a risk for this condition. CONCLUSION: Our results suggest that BTN2A1 may be a susceptibility gene for CKD in Japanese individuals.

Current status of a helicopter transportation system on remote islands for patients undergoing mechanical thrombectomy.

BACKGROUND: Mechanical thrombectomy (MT) is standard treatment for acute ischemic stroke (AIS) with large-vessel occlusion within 6 h of symptom onset to treatment initiation (OTP). Recent trials have extended the therapeutic time window for MT to within 24 h. However, MT treatment remains low in remote areas. Nagasaki Prefecture, Japan has many inhabited islands with no neurointerventionalists. Our hospital on the mainland is a regional hub for eight island hospitals. We evaluated clinical outcomes of MT for patients with AIS on these islands versus on the mainland. METHODS: During 2014-2019, we reviewed consecutive patients with AIS who received MT at our hospital. Patients comprised the Islands group and Mainland group. Patient characteristics and clinical outcomes were compared between groups. RESULTS: We included 91 patients (Islands group: 15 patients, Mainland group: 76 patients). Seven patients (46.7%) in the Islands group versus 43 (56.6%) in the Mainland group achieved favorable outcomes. Successful recanalization was obtained in 11 patients (73.3%) on the islands and 67 (88.2%) on the mainland. The median OTP time in the Islands was 365 min. In both the Islands and Mainland groups, the OTP time and successful recanalization were associated with functional outcome. The modified Rankin Scale (mRS) score at 90 days ≤2 was obtained in two patients and mRS = 3 in four patients among eight patients with OTP time >6 h. CONCLUSIONS: Few patients with AIS on remote islands have received MT. Although patients who underwent MT on the islands had longer OTP, the clinical outcomes were acceptable. OTP time on remote islands must be shortened, as this is related to functional outcome. In some cases with successful recanalization, a favorable outcome can still be obtained even after 6 h. Even if OTP exceeds 6 h, it is desirable to appropriately select patients and actively perform MT.

IFN-γ and TNF-α synergistically induce microRNA-155 which regulates TAB2/IP-10 expression in human mesangial cells.

BACKGROUND/AIMS: MicroRNAs are noncoding small RNA molecules that posttranscriptionally regulate gene expression. microRNA-155 (miR-155), one of the microRNAs, is involved in the control of various genes. However, the role of miR-155 in inflammatory responses in mesangial cells is not known. In the present study, we examined the expression of miR-155 in mesangial cells. METHODS: The expression of miR-155 in cultured normal human mesangial cells treated with interferon-γ (IFN-γ) and/or tumor-necrosis factor-α (TNF-α) was examined. The cells were transfected with miR-155 mimic, siRNA against transforming growth factor-ß-activated kinase-1 (TAK1)-binding protein 2 (TAB2) or siRNA against nuclear factor-κB (NF-κB). RESULTS: IFN-γ and TNF-α synergistically induced the expression of miR-155. Transfection of cells with miR-155 mimic inhibited the expression of TAB2 and IFN-γ-inducible protein of 10 kDa (IP-10). The expression of IP-10 was suppressed by knockdown of TAB2. Induction of miR-155 was inhibited by RNA interference against TAB2 or NF-κB. CONCLUSION: Combined stimulation with IFN-γ and TNF-α induces miR-155 via TAB2 and NF-κB. miR-155 negatively regulates TAB2, as a negative feedback system, to lower IP-10 expression. miR-155 may play a role in the regulation of inflammatory and immune reactions in the kidney.

Retinoic acid-inducible gene-I is induced by double-stranded RNA and regulates the expression of CC chemokine ligand (CCL) 5 in human mesangial cells.

BACKGROUND: Retinoic acid-inducible gene-I (RIG-I) is a putative RNA helicase involved in immune reactions against RNA viruses and various inflammatory and autoimmune diseases. The purpose of the present study was to investigate the role of RIG-I in glomerular diseases. METHODS: We treated human mesangial cells in culture with polyinosinic-polycytidylic acid (poly IC), which is an authentic double-stranded RNA, and analysed the expression of RIG-I, CC chemokine ligand 5 (CCL5) and interferon (IFN)-ß by western blotting, reverse transcriptase-polymerase chain reaction (RT-PCR) or enzyme-linked immunosorbent assay (ELISA). To elucidate the poly IC-signalling pathway, we subjected the cells to RNA interference (RNAi) against RIG-I, IFN-ß or Toll-like receptor (TLR) 3. Furthermore, we studied the effects of IFN-ß receptor blocking and IFN-ß overexpression. RESULTS: Poly IC induced the expression of RIG-I and CCL5 in human mesangial cells, and RNAi against RIG-I inhibited this poly IC-induced CCL5 expression. Poly IC-induced RIG-I expression was also inhibited by RNAi against IFN-ß and by an antibody against the IFN-ß receptor. IFN-ß overexpression induced the expression of both RIG-I and CCL5. The knockdown of TLR3 abolished poly IC-induced RIG-I expression. CONCLUSIONS: The TLR3/IFN-ß/RIG-I/CCL5 signalling pathway may mediate immune and inflammatory responses against viral infection in mesangial cells, suggesting the role of this pathway in the aggravation of glomerulonephritis due to viral infection.