The adenosine A2B receptor is involved in anion secretion in human pancreatic duct Capan-1 epithelial cells.

Adenosine modulates a wide variety of biological processes via adenosine receptors. In the exocrine pancreas, adenosine regulates transepithelial anion secretion in duct cells and is considered to play a role in acini-to-duct signaling. To identify the functional adenosine receptors and Cl(-) channels important for anion secretion, we herein performed experiments on Capan-1, a human pancreatic duct cell line, using open-circuit Ussing chamber and gramicidin-perforated patch-clamp techniques. The luminal addition of adenosine increased the negative transepithelial potential difference (V te) in Capan-1 monolayers with a half-maximal effective concentration value of approximately 10 µM, which corresponded to the value obtained on whole-cell Cl(-) currents in Capan-1 single cells. The effects of adenosine on V te, an equivalent short-circuit current (I sc), and whole-cell Cl(-) currents were inhibited by CFTRinh-172, a cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel inhibitor. The adenosine A2B receptor agonist, BAY 60-6583, increased I sc and whole-cell Cl(-) currents through CFTR Cl(-) channels, whereas the A2A receptor agonist, CGS 21680, had negligible effects. The A2B receptor antagonist, PSB 603, inhibited the response of I sc to adenosine. Immunohistochemical analysis showed that the A2A and A2B receptors colocalized with Ezrin in the luminal membranes of Capan-1 monolayers and in rat pancreatic ducts. Adenosine elicited the whole-cell Cl(-) currents in guinea pig duct cells. These results demonstrate that luminal adenosine regulates anion secretion by activating CFTR Cl(-) channels via adenosine A2B receptors on the luminal membranes of Capan-1 cells. The present study endorses that purinergic signaling is important in the regulation of pancreatic secretion.

Gas Exchanges and Dehydration in Different Intensities of Conditioning in Tifton 85 Bermudagrass: Nutritional Value during Hay Storage.

The present study aimed at evaluating the intensity of Tifton 85 conditioning using a mower conditioner with free-swinging flail fingers and storage times on dehydration curve, fungi presence, nutritional value and in vitro digestibility of Tifton 85 bermudagrass hay dry matter (DM). The dehydration curve was determined in the whole plant for ten times until the baling. The zero time corresponded to the plant before cutting, which occurred at 11:00 and the other collections were carried out at 8:00, 10:00, 14:00, and 16:00. The experimental design was randomised blocks with two intensities of conditioning (high and low) and ten sampling times, with five replications. The high and low intensities related to adjusting the deflector plate of the free iron fingers (8 and 18 cm). In order to determine gas exchanges during Tifton 85 bermudagrass dehydration, there were evaluations of mature leaves, which were placed in the upper middle third of each branch before the cutting, at every hour for 4 hours. A portable gas analyser was used by an infrared IRGA (6400xt). The analysed variables were photosynthesis (A), stomatal conductance (gs), internal CO2 concentration (Ci), transpiration (T), water use efficiency (WUE), and intrinsic water use efficiency (WUEi). In the second part of this study, the nutritional value of Tifton 85 hay was evaluated, so randomised blocks were designed in a split plot through time, with two treatments placed in the following plots: high and low intensity of cutting and five different time points as subplots: cutting (additional treatment), baling and after 30, 60, and 90 days of storage. Subsequently, fungi that were in green plants as well as hay were determined and samples were collected from the grass at the cutting period, during baling, and after 30, 60, and 90 days of storage. It was observed that Tifton 85 bermudagrass dehydration occurred within 49 hours, so this was considered the best time for drying hay. Gas exchanges were more intense before cutting, although after cutting they decreased until ceasing within 4 hours. The lowest values of acid detergent insoluble nitrogen were obtained with low conditioning intensity after 30 days of storage, 64.8 g/kg DM. The in vitro dry matter of Tifton 85 bermudagrass did not differ among the storage times or the conditioning intensities. There was no fungi present in the samples collected during the storage period up to 90 days after dehydration, with less than 30 colony forming units found on plate counting. The use of mower conditioners in different intensities of injury did not speed up the dehydration time of Tifton 85.

Visible-light-controlled homo- and copolymerization of styrenes by a bichromophoric Ir-Pd catalyst.

Visible-light-controlled polymerization was achieved by a bichromophoric organopalladium catalyst which possesses a naphthyl-substituted cyclometallated Ir(III) light-absorbing moiety. The complex was highly active toward styrene polymerization upon visible-light irradiation, and its photoactivity toward polymerization and dimerization was switchable. On the basis of the switching activity, controlled copolymerization of styrene and vinyl ether was achieved upon photo-irradiation to give the corresponding copolymers.

Clinical study of tympanostomy tube placement for patients with intractable Ménière's disease.

OBJECTIVE: To evaluate the effectiveness of tympanostomy tube placement in controlling symptoms of intractable Ménière's disease. METHODS: Fifteen patients with intractable Ménière's disease underwent tympanostomy tube placement in the affected ear. Post-operative changes in vertigo attacks and hearing level were recorded, and were evaluated according to American Academy of Otolaryngology-Head and Neck Surgery criteria. RESULTS: At 12 months after treatment, 3 patients (20 per cent) showed complete control of vertigo, 7 (47 per cent) showed substantial control and 2 (13 per cent) showed limited control; 3 patients (20 per cent) required other treatment. At 24 months after treatment, 7 patients (47 per cent) showed complete control of vertigo, 3 (20 per cent) showed substantial control and 1 (7 per cent) showed limited control; 1 patient required other treatment 15 months after tympanostomy tube placement. CONCLUSION: There is no definite pathophysiological explanation for the effect of tympanostomy tube placement in reducing vertigo attacks. This treatment is not effective for all patients with intractable Ménière's disease. However, tympanostomy tube placement might be an additional surgical therapeutic option to consider prior to contemplating other, more invasive treatments.

The influence of collagen III expression on the efficiency of cell isolation with the use of collagenase H.

OBJECTIVE: We previously demonstrated that collagenase H (ColH) plays a crucial role in rat islet isolation, whereas collagenase G (ColG) plays only a supporting role. We also showed that collagen III appears to be one of the key targets of ColH based on a mass spectrometry analysis. In the present study, we investigated whether our novel findings in an islet isolation model are universally applicable for other types of cell isolation, such as a hepatocyte isolation, with the use of enzyme blends of recombinant collagenases. METHODS: As the first step, the expression of one of the main matrix components, collagen III, on rat pancreatic and hepatic tissues was assessed with the use of immunohistochemical staining. ColG and ColH were expressed in recombinant E. coli carrying expression plasmids for each collagenase. Then the efficiency of the collagenase subtype on rat hepatocyte isolation was evaluated in terms of cell yield with the use of thermolysin combined with either ColG or ColH (n = 3, respectively). RESULTS: The expression of collagen III on rat hepatic tissues was dramatically lower than that of rat pancreatic tissues. In the rat hepatocyte isolation, a substantial amount of hepatocytes (0.81 ± 0.11 × 10(6)) were obtained in the ColG group, whereas almost no hepatocytes were retrieved in the ColH group, indicating that the influence of the collagenase subtypes in rat hepatocyte isolation are completely opposite to that observed in rat islet isolation. CONCLUSIONS: Considering that the expression of collagen III on hepatic tissues was relatively low and that almost no hepatocytes were retrieved when ColH and thermolysin were used, the present study supports our novel finding that collagen III appears to be one of the key targets of ColH in hepatocyte isolation. Therefore, the semiquantification of collagen III on the target tissues not only may positively contribute to efficient islet isolation, but also may affect other types of cell isolation by optimizing the ColH amount.

Contribution of fetal ANXA5 gene promoter polymorphisms to the onset of pre-eclampsia.

OBJECTIVE: A common haplotype M2 consisting of minor SNP alleles located in the ANXA5 gene promoter region has been described as a risk factor for various obstetric complications such as recurrent pregnancy loss, pre-eclampsia and pregnancy-related thrombophilic disorder. However, the question of whether it is the maternal or fetal genotype that contributes to the onset of these disorders remains to be resolved. METHODS: We analyzed ANXA5 gene variants in the blood and placental tissues from pre-eclampsia patients and normotensive controls. ANXA5 expression was examined by qRT-PCR, Western blotting and immunostaining. Results were compared between M2 and non-M2 carriers. RESULTS: The M2 haplotype was found to be significantly frequent in placentas from pre-eclamptic patients relative to the controls (25.5% versus 10%, P = 0.044), In contrast, no significant differences were observed in maternal blood (13.0% versus 11.3%, P = 0.597). The placental expression of ANXA5 mRNA was found to be lower in M2 carriers. When examined by Western blot and immunostaining, the ANXA5 protein levels were found to be affected more by the placental than the maternal genotype. Histological examination of the placentas from the pre-eclamptic patients demonstrated that a placental M2 haplotype correlated more closely than maternal M2 with the severity of perivillous fibrin deposition. CONCLUSIONS: Although preliminary, these results suggest that hypomorphic M2 alleles in the in placental ANXA5 promoter, whether transmitted maternally or paternally, might be an essential determinant of an increased risk of pre-eclampsia via local thrombophilia at the feto-maternal interface.

Upregulation of HtrA4 in the placentas of patients with severe pre-eclampsia.

High temperature requirement A (HtrA) family proteins are serine proteases that may serve in the quality control of misfolded or mislocalized proteins. Recently, possible involvements of HtrA1 in the normal development of the placenta and in the pathogenesis of pre-eclampsia were reported. In this study, we characterized HtrA4, a previously uncharacterized HtrA protein family member, in pre-eclampsia. Elevated expression levels of placental HtrA4 in pre-eclampsia patients were observed by qRT-PCR. Western blotting also showed an increased production of HtrA4 at the protein level in pre-eclamptic placentas. In normal chorionic villi, HtrA4 protein was more abundant in the cytoplasm of cytotrophoblasts than in syncytiotrophoblasts. In contrast, the amount of HtrA4 protein in syncytiotrophoblasts was dramatically increased in pre-eclamptic placentas. Circulating HtrA4 was detected at higher levels in sera from women with pre-eclampsia than from those with normotensive pregnancies. Serum HtrA4 levels were higher in patients with early onset and inversely correlated with the weights of the newborn and placenta. Furthermore, serum levels correlated with serum PAPP-A and PAPP-A2 levels, indicating a functional role for HtrA4 in the common pathway. These data suggest that increased HtrA4 may be involved in the onset of pre-eclampsia, and elevated levels in sera imply a potential application as a biomarker for this disorder.

Downregulated plasma miR-92a levels have clinical impact on multiple myeloma and related disorders.

Recent studies have demonstrated that one-third of known microRNAs (miRNAs) are stably detectable in plasma. Therefore, we assessed plasma miRNAs to investigate the dynamics of oncomir 17-92a, which is highly expressed in multiple myeloma (MM) patients. The plasma miR-92a level in symptomatic MM patients was significantly downregulated compared with normal subjects (P<0.0001), regardless of immunoglobulin subtypes or disease stage at diagnosis. In contrast, miR-92a levels in peripheral blood CD8(+) or CD4(+) cells from MM patients were lower than those of normal subjects, and the miR-92a levels of the cells tended to correlate with plasma miR-92a levels. The plasma miR-92a level in the complete remission group became normalized, whereas the partial response (PR) and very good PR groups did not reach the normal range. In smoldering MM, the plasma miR-92a level did not show a significant difference compared with normal subjects. Our findings suggest that measurement of the plasma miR-92a level in MM patients could be useful for initiation of chemotherapy and monitoring disease status, and the level may represent, in part, the T-cell immunity status of these patients.

Effect of synthetic protease inhibitor gabexate mesilate on attenuation of coagulant activity and cytokine release in a rat model of islet transplantation.

BACKGROUND: The instant blood-mediated inflammatory reaction (IBMIR), in which the activation of coagulation cascade plays a key role, is one of the serious obstacles to successful islet engraftment. Gabexate mesilate (GM) is well known to elicit anticoagulant and antiinflammatory effects. The aim of this study was to evaluate the effect of GM on syngeneic IBMIR. METHODS: Syngeneic rat islet grafts (2.5 IEQ/g) were transplanted intraportally into 2 groups (control group and GM group; n = 10-11) of streptozotocin-induced diabetic rats. The GM group was injected intravenously with GM for 30 minutes before islet infusion to 1 hour after. The control group was injected with equivalent amount of saline solution. Plasma samples were collected before and 0.5, 1, 3, 6, and 24 hours after transplantation, and several proinflammatory mediators, including interleukin-6 and high-mobility group Box 1 were measured. Curative rate, intravenous glucose tolerance test, and insulin amount in the recipients' livers were also evaluated. RESULTS: Little difference was observed in any proinflammatory mediators. Whereas none of the animals in the control group became normoglycemic, 2 of 6 rats transplanted with the same number of islets in the GM group became normoglycemic during the study period. The glucose tolerance response was significantly ameliorated in the GM group compared with the control group (P < 0.001). The insulin amount in the liver of the recipients was considerably higher in the GM group (5.6 ± 4.1 vs 12.6 ± 5.3 ng/IEQ; P < .05). CONCLUSIONS: These data suggest that GM improves islet engraftment not through suppressing the proinflammatory cytokines but as an anticoagulant. We therefore think that GM could be a useful anticoagulant to control IBMIR induced in clinical islet transplantation, although antiinflammatory reagents are considered to be needed for the ideal regimen.

Expression of receptors for anaphylatoxins C3a and C5a on rat islet preparations.

BACKGROUND: Complement activation has been implicated in the development of the instant blood-mediated inflammatory reaction (IBMIR). In particular, anaphylatoxins C3a and C5a elicit a broad range of proinflammatory effects, including chemotaxis of inflammatory cells and cytokine release. We have previously shown that 2 types of receptors for C5a are expressed on isolated islets. In the present study, we investigated this component in detail. METHODS: C3aR, C5aR, and C5L2, together with CD11b and CD31, on freshly isolated islets (fresh group) and islets cultured with (cytokine group) or without (culture group) TNF-α, IL-1ß, and IFN-γ for ∼12 hours were analyzed by flow cytometry. In addition, these 3 kinds of receptors were analyzed on nonendocrine cells. RESULTS: C5aR and C5L2 were expressed on the isolated islets (C5aR: 7.91 ± 2.83%; C5L2: 2.45 ± 1.34%) and the expression of both C5a receptors was markedly attenuated by culture for 12 hours (C5aR: P < .005; C5L2: P < .05). Compared with the culture group, the expression was significantly up-regulated in the cytokine group (C5aR: P < .05; C5L2: P = .05). C5aR-positive cells expressed CD11b but not CD31. In contrast to islets, nonendocrine cells expressed C5L2 predominantly. C3aR was scarcely expressed on isolated islets or nonendocrine cells. CONCLUSIONS: These data suggest that C5aR and C5L2 are expressed on CD11b-positive leukocytes in islet preparations. Depletion of C5a receptors by culturing appropriately could be an attractive therapeutic strategy in clinical islet transplantation.

A precise analysis of C5a inhibitory peptide on inflammatory mediators induced after islet transplantation.

OBJECTIVE: We recently reported that C5a inhibitory peptide (C5aIP) prevents the instant blood-mediated inflammatory reaction by attenuating cross talk between complement and coagulation cascades. C5aIP has also been shown to possess a broad range of anti-inflammatory effects. Due to methodological limitations, it is difficult to perform detailed analyses on wide range of inflammatory mediators in rat model. Therefore, we examined whether C5aIP suppressed various inflammatory cytokines induced after islet transplantation using a mouse model. METHODS: Six islet equivalents per gram of syngeneic mouse islet grafts were transplanted intraportally into two groups of streptozotocin-induced diabetic mice: control group (n = 8) and C5aIP group (n = 6). The C5aIP group was treated with a bolus of 4 mg/kg just after islet infusion and a continuous infusion of 0.4 mg/kg/h, whereas the control group was injected with equivalent amounts of saline. Serum samples were collected at 0, 6, and 24 hours after transplantation. We analyzed 23 types of cytokines: interleukins-1a, -1b, -3, -4, -5, -6, -9, -10, -12, -13, and -17; eotaxin; G-CSF; GM-CSF; interferon (INF) gamma; KC; MCP-1; MIP-1 and -1b, RANTES and tumor necrosis factor-alpha. Leukocytes in the recipient liver were isolated at 6 hours after transplantation to examine IFN gamma production by fluorescence activated cell sorting (FACS). RESULTS: No significant difference was detected in terms of the major inflammatory cytokines between the two groups. INF gamma production on CD11b(+)Gr-1(+) cells in the liver was not significantly inhibited by C5aIP (control 30.0% vs C5aIP 24.1%). CONCLUSIONS: These data suggested that beneficial effects of C5aIP on islet engraftment are mainly due to blockade of cross talk between complement and coagulation cascades, rather than the suppression of inflammatory mediators.

The impact of ischemic stress on the quality of isolated pancreatic islets.

BACKGROUND: Although the ischemic stress of donated organs has been shown to have strong negative effects on islet recovery, the impact on islet quality remains uncertain. In the present study, therefore, we examined the influence of ischemic stress on the expression of inflammatory mediators among isolated islets. MATERIALS AND METHODS: Islets were isolated from adult porcine pancreata subjected to 16-hour cold ischemia time (CIT) in addition to 40-minute warm ischemia time (WIT). We evaluated the islet yield, islet loss during the first 24 hours in culture, adenosine diphosphate (ADP)/adenosine triphosphate (ATP) ratio, ATP/DNA ratio, glucose-stimulated respiratory activity, in vivo bioassay, and the expression of inflammatory mediators (tissue factor [TF], [MCP-1], macrophage migration inhibitory factor) on the isolated islets. We also analyzed ATP/DNA ratios of the exocrine tissues during isolation procedures. RESULTS: The islet yield, survival rate during culture, and glucose-stimulated respiratory activity were significantly lower in cases of 16-hour CIT plus 40-minute WIT compared with the control group (P < .0001, .0006, and .002, respectively). In contrast, ADP/ATP ratio as well as TF and MCP-1 expressions on the isolated islets were higher among the ischemic group (P = .005, .16, and .005, respectively). During isolation procedures, the ATP/DNA of the exocrine tissues was extremely lower in the ischemic compared to the control group (P < .0001). Notably, however, both ATP/DNA and ADP/ATP ratio of isolated islets were well preserved even in the ischemic group (P = .45 and .40). DISCUSSION: These data suggest that ischemic stress during the preservation period negatively affects the energy status of exocrine tissues. Destruction of the exocrine tissues, in combination with warm ischemic stress during the isolation procedures, subsequently decreases isolated islet activity, inducing the expression of inflammatory mediators.

C5a-inhibitory peptide combined with gabexate mesilate prevents the instant blood-mediated inflammatory reaction in a rat model of islet transplantation.

BACKGROUND: The instant blood-mediated inflammatory reaction (IBMIR), in which the activation of both the coagulation and the complement cascades plays a key role, is one of the main obstacles to successful islet transplantation. At present, however, no useful protocol is clinically available. Therefore the aim of this study was to examine whether complementary peptides against an active region of C5a were safe to suppress IBMIR, owing to their extremely low molecular mass, when combined with a clinically available anticoagulant. METHODS: Complement receptors on pancreatic tissues and isolated islets were analyzed by immunohistochemical staining and flow cytometry. Two-and-a-half islet equivalents per gram of syngeneic rat islet grafts were transplanted intraportally into 4 groups of 10-13 animals each after streptozotocin induction of diabetes: control, gabexate (Gab), C5a-inhibitory peptide (C5aINH), and C5aINH plus Gab. Recipients injected with equivalent amounts of saline solution served as control subjects. Plasma samples were collected at 0, 0.5, 1, 3, 6, and 24 h after transplantation for analysis. We also evaluated the curative rate, intravenous glucose tolerance test, and insulin amounts in the liver of the recipients. RESULTS: C3a receptor (C3aR) was scarcely expressed on the isolated islets with relatively strong expression of C5a receptor (C5aR): C3aR: 0.44 +/- 0.38%; C5aR: 7.91 +/- 2.83%). However, C5aR was not expressed on pancreatic tissues before the isolation procedures. Thrombin-antithrombin complex was significantly suppressed in the 3 treated groups (P = .0015). The curative rate was also significantly improved (0% vs 33% vs 67% vs 100%, respectively; P = .03). Glucose tolerance was significantly improved among the 3 treated groups (P < .0005). Insulin amounts in the liver were considerably higher among treated versus control hosts. Notably, the treatment did not affect the increased body weight of the recipient. CONCLUSIONS: This study suggested that C5a-inhibitory peptide combined with gabexate mesilate may be a useful approach to control the IBMIR induced in clinical islet transplantation and one that is free of side effects.

Bortezomib-resistant myeloma cell lines: a role for mutated PSMB5 in preventing the accumulation of unfolded proteins and fatal ER stress.

Bortezomib is an effective agent for treating multiple myeloma (MM). To investigate the underlying mechanisms associated with acquired resistance to this agent, we established two bortezomib-resistant MM cell lines, KMS-11/BTZ and OPM-2/BTZ, the 50% inhibitory concentration values of which were respectively 24.7- and 16.6-fold higher than their parental cell lines. No activation of caspase and BH3-only proteins such as Noxa was noted in bortezomib-resistant cells after exposure to the drug. The accumulation of polyubiquitinated proteins was reduced in bortezomib-resistant cells compared with the parental cells, associated with avoidance of catastrophic ER stress as assessed by downregulation of CHOP expression. These resistant MM cells have a unique point mutation, G322A, in the gene encoding the proteasome beta5 subunit (PSMB5), likely resulting in conformational changes to the bortezomib-binding pocket of this subunit. KMS-11 parental cells transfected to express mutated PSMB5 also showed reduced bortezomib-induced apoptosis compared with those expressing wild-type PSMB5 or the parental cells. Expression of mutated PSMB5 was associated with the prevention of the accumulation of unfolded proteins. Thus, a fraction of MM cells may acquire bortezomib resistance by suppressing apoptotic signals through the inhibition of unfolded protein accumulation and subsequent excessive ER stress by a mutation of the PSMB5 gene.

A novel predictive method for assessing the quality of isolated pancreatic islets using scanning electrochemical microscopy.

INTRODUCTION: The current methods for evaluating islet potency are not useful in clinical transplantation. Therefore, we need reliable, rapid methods enabling accurate prediction of islet quality. MATERIALS AND METHODS: We evaluated respiratory activity using scanning electrochemical microscopy (SECM), glucose-stimulated respiratory activity, glucose-stimulated insulin release, ADP/ATP assays, insulin/DNA levels, and Trypan blue exclusion tests as predictive methods for the ability of isolated rat islets to cure syngeneic diabetic rats. RESULTS: Although glucose-stimulated respiratory activity, basal respiratory activity, ADP/ATP ratio, and glucose-stimulated insulin release were significantly correlated with the outcome of transplantation into diabetic rats, there was no correlation between outcomes, insulin/DNA ratios, and Trypan blue exclusion tests. The glucose-stimulated respiratory activity in islet preparations that could cure diabetic rats was significantly greater than those unable to cure diabetes. Rat islets with >1.5-fold glucose-stimulated respiratory activity consistently cured diabetic rats, whereas those with a value <1.5 hardly cured any rats. CONCLUSION: Measurement of the glucose-stimulated respiratory activity using SECM technique is a novel method that may be useful as a rapid, potent predictor of the outcome of clinical islet transplantation.

The CCR4 as a novel-specific molecular target for immunotherapy in Hodgkin lymphoma.

Here, we report that tumor cells from some patients (23.8%) with Hodgkin lymphoma (HL) are positive for CC chemokine receptor 4 (CCR4). We therefore tested the chimeric anti-CCR4 monoclonal antibody (mAb), KM2760, the Fc region of which is defucosylated to enhance antibody-dependent cellular cytotoxicity (ADCC), as a novel immunotherapy for refractory HL. KM2760 demonstrated a promising antitumor activity in the CCR4-positive HL-bearing mouse model in the therapeutic setting. Although KM2760 did not induce any ADCC mediated by mouse natural killer (NK) cells, it significantly enhanced phagocytosis mediated by mouse monocytes/macrophages against the CCR4-positive HL cell line in vitro. Together with the findings that KM2760 did not exhibit any complement-dependent cytotoxicity or direct antiproliferation activity in vitro, these data indicated that KM2760 exerted its robust in vivo antitumor activity via monocytes/macrophages in mice. In the human system, KM2760 enhanced phagocytic activity mediated by monocytes/macrophages. Furthermore, it induced robust ADCC mediated by NK cells against the CCR4-positive HL cell line in vitro. Thus, it is conceivable that KM2760 would have much more potent antitumor activity in humans than in mice. Collectively, this study strongly indicates that anti-CCR4 mAb could be a novel treatment modality for patients with CCR4-positive HL.

Positron emission tomography and magnetic resonance imaging in spinocerebellar ataxia type 2: a study of symptomatic and asymptomatic individuals.

Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant neurodegenerative disorder characterized as an expanded CAG trinucleotide repeats in SCA2 gene resulting in abnormal polyglutamine sequence. We used positron emission tomography (PET) and magnetic resonance imaging (MRI) to clarify metabolic and atrophic changes of the brain in two symptomatic and three asymptomatic individuals who were genetically confirmed for SCA2. PET revealed decreased glucose metabolism in both patients and two of the three asymptomatic carriers in the cerebellum, pons, or both. No PET abnormality was found in the remaining one carrier who had only a very mildly expanded CAG repeat. MRI showed cerebellar and/or pontine atrophic changes in both patients and one of three carriers. The present study suggest that hypometabolism and atrophy of the cerebellum and pons may occur years before the clinical onset of SCA2. PET and MRI may be useful in the early detection of subclinical brain changes associated with SCA2.