Abstract 1002: Epigenetic and genetic characteristics and their association with prognosis of follicular lymphoma: Analysis at a Japanese single institution

[Background] Epigenetic and genetic characteristics in Japanese follicular lymphoma (FL) patients have been scarcely evaluated. EHZ2 represents a new therapeutic target in FL and identifying candidates for EZH2 inhibition medication in the general hospital settings without access to genetic sequencing is critical. Since EZH2 regulates methylation at the 27th amino acid in Histone (H3K27), we evaluated the characteristics of EZH2 expression and H3K27 methylation in the Japanese FL cohort as well as their association with genetic characteristics. Prognostic impact of these factors on clinical outcomes was also examined.

[Method and Patients] A total of 164 patients (female, n=91; male, n=73) diagnosed with FL at Kyoto University Hospital between 2005 and 2020 were included. A total of 105 patients were assessed immunohistochemically using H-score for EZH2 expression (EZH2-score) and H3K27me3/me2 scoring (Methylation-score). Impact of these scores at diagnosis on overall survival (OS) and progression/relapse after the 1st immunochemotherapy were examined. We also performed next generation sequencing for 357 genes for 116 samples at diagnosis and examined their correlation with immunohistochemical characteristics.

[Results] Median age at diagnosis was 61 years (range, 33-86) and the median follow-up years was 7.5. Median EZH2-score was 70 (range, 0-290) and median Methylation-score was 2.38 (range, -4.25-4.95), with no apparent correlation. Twenty-five patients (21.6%) harbored EZH2 mutations at diagnosis, all of which were in the mutation hotspots and showed a strong correlation with high Methylation-scores (p-value < 0.001). Based on the prognostic impact of Methylation- and EZH2-score on survival, patients were divided into 3 groups: Group I, those with low Methylation-scores (<2) and high EZH2-scores (≥100); Group II, those with low Methylation-scores (<2) and low EZH2-scores (<100); Group III, those with high Methylation scores (≥100). Group I showed inferior OS compared to Group III (p=0.038) with high risk of rapid relapse/progression (62.5%) within 2 years, who frequently harbored mutations in CSMD3 (vs Group III: p=0.004), KMT2D (p<0.001) and SETD1B (p<0.001). Distribution of mutated genes among Group III patients differed according to the existence of EZH2 mutation, with high frequency of mutated USH2A (p=0.019) and MGAM (p=0.019) genes in those with EZH2 mutation, whereas mutations in TP53 were observed only in those without (p=0.072).

[Conclusion] Methylation-score could be helpful in distinguishing patients with and without EZH2 mutations and enables clinicians to identify candidates for EZH2 inhibition medications. Combination of EZH2- and Methylation-scores predicts clinical outcomes after the 1st immunochemotherapy, which also could potentially identify genetically distinct population in the heterogeneous FL cohort.

Citation Format: Mizuki Watanabe, Naoki Goda, Junya Kanda, Akihiko Yoshizawa, Momoko Nishikori, Yasuhito Nannya, Kenichi Yoshida, Seishi Ogawa, Hironori Haga, Akifumi Takaori-Kondo. Epigenetic and genetic characteristics and their association with prognosis of follicular lymphoma: Analysis at a Japanese single institution [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1002.

Medium-chain fatty acids enhance expression and histone acetylation of genes related to lipid metabolism in insulin-resistant adipocytes

Background

The expressions of genes related to lipid metabolism are decreased in adipocytes with insulin resistance. In this study, we examined the effects of fatty acids on the reduced expressions and histone acetylation of lipid metabolism-related genes in 3T3-L1 adipocytes treated with insulin resistance induced by tumor necrosis factor (TNF)-α.

Methods

Short-, medium-, and long-chain fatty acid were co-administered with TNF-α in 3T3-L1 adipocytes. Then, mRNA expressions and histone acetylation of genes involved in lipid metabolism were determined using mRNA microarrays, qRT-PCR, and chromatin immunoprecipitation assays.

Results

We found in microarray and subsequent qRT-PCR analyses that the expression levels of several lipid metabolism-related genes, including Gpd1, Cidec, and Cyp4b1, were reduced by TNF-α treatment and restored by co-treatment with a short-chain fatty acid (C4: butyric acid) and medium-chain fatty acids (C8: caprylic acid and C10: capric acid). The pathway analysis of the microarray showed that capric acid enhanced mRNA levels of genes in the PPAR signaling pathway and adipogenesis genes in the TNF-α-treated adipocytes. Histone acetylation around Cidec and Gpd1 genes were also reduced by TNF-α treatment and recovered by co-administration with short- and medium-chain fatty acids.

General significance

Medium- and short-chain fatty acids induce the expressions of Cidec and Gpd1, which are lipid metabolism-related genes in insulin-resistant adipocytes, by promoting histone acetylation around these genes.

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Expressions of lipid metabolism genes are reduced in insulin-resistant adipocytes.

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Short- and medium-chain fatty acids inhibit lipid metabolism gene downregulation.

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Capric acid enhances expressions of PPAR signaling and adipogenesis genes.

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This mechanism involves recovery of histone acetylation in lipid metabolism genes.

Chronic Expanding Hematomas That Occurred 20 Years or More After Primary Total Hip Arthroplasty: A Report of 2 Cases

CASE

We report 2 patients who developed chronic expanding hematomas (CEHs) more than 20 years after ceramic-on-polyethylene total hip arthroplasty (THA). One CEH occurred after a minor fall, and the other appeared with no obvious injury. Neither of the 2 was on anticoagulation. Each caused extensive osteolysis.

CONCLUSION

The only 2 previously reported post-THA cases of CEH involved metal-on-metal THAs and occurred several years after the index THA. Our patients show that CEH also can occur after ceramic-on-polyethylene THA, even after an uneventful clinical course of more than 20 years. Complete removal of both hematoma stopped osteolytic progression, with no recurrence to date.

Desmoplastic myxoid tumor, SMARCB1-mutant: a new variant of SMARCB1-deficient tumor of the central nervous system preferentially arising in the pineal region

Desmoplastic myxoid tumor (DMT), SMARCB1-mutant is a recently proposed brain tumor that occurs in the pineal region of adults. This tumor is characterized by desmoplastic stroma and various degrees of myxoid matrix. Tumor cells with low-grade morphology show polyphenotypic immunoreactivity, and rhabdoid cells are rare. We herein present a case with some uncommon features such as no myxoid stroma and slightly elevated proliferating activity. To date, knowledge on the variety of SMARCB1/INI1-deficient tumors of the central nervous system is gradually increasing, encompassing highly aggressive to slow-growing varieties. DMT, SMARCB1-mutant seems to be relatively benign, but careful attention is necessary because SMARCB1/INI1 deficiency is generally a genetic signature of concern.

Non-aneurysmal Subarachnoid Hemorrhaging: A Rare Cause of Death in a Patient with Multiple System Atrophy

Sudden death as a result of multiple system atrophy (MSA) is usually attributed to vocal cord paralysis or disruption of breathing owing to the degeneration of the brainstem respiratory centers. However, the exact pathophysiology of sudden death is still unclear. In addition, specific causes of sudden death are not always investigated by an autopsy. We herein report a patient with MSA and non-aneurysmal subarachnoid hemorrhaging, which is believed to be a rare cause of death in this setting. Without an autopsy, our case would likely have been diagnosed as sudden death due to vocal cord paralysis. To develop effective strategies to prevent sudden death, a post-mortem investigation is important in order to exclude known structural causes of death.

Abstract P6-02-09: Diagnostic performance of dedicated breast PET for the prediction of pathological response after neoadjuvant chemotherapy

Background: Neoadjuvant chemotherapy (NAC) is a standard treatment for operable breast cancer. However, imaging methods for evaluating treatment response have not been established. Previous studies reported that ring-type dedicated breast positron emission tomography (DbPET) detected residual tumors following NAC more accurately than whole-body PET/CT. This study assessed DbPET parameters for predicting pathological complete response (pCR) in patients with breast cancer.

Patients and Methods: Among patients with breast cancer who underwent surgery after NAC, 61 were examined using ring-type DbPET before and after NAC. The maximum standardized uptake values (SUVmax) and tumor-to-normal-tissue ratio (TNR) were calculated before and after NAC (pre-SUVmax, pre-TNR, post-SUVmax and post-TNR, respectively). Moreover, the reduction rates (ΔSUVmax and ΔTNR) were determined. pCR was defined as complete remission of breast cancer.

Results: The median patient age was 52 years. Forty patients (65.6%) were estrogen receptor (ER)-positive, whereas 25 patients (41.0%) were HER2-positive. Fifteen patients (24.6%) achieved pCR after NAC. The calculated values for the parameters of DbPET are summarized in Table 1. The most promising parameters for predicting pCR were ΔSUVmax (area under the curve [AUC]: 0.506) and post-TNR (AUC: 0.640). Although neither of these two parameters reflected the pathological response to NAC in patients with ER-positive disease, post-TNR showed the highest AUC (i.e., AUC: 0.750) for pCR in patients with ER-negative disease. The sensitivity and specificity of post-TNR in the ER-positive group were 85.7% and 39.4%, respectively. In the ER-negative group, these values were 100% and 58.3%, respectively [Table 2]

Table 1.Diagnostic performance of dedicated breast positron-emission tomography for the prediction of pathological complete response after neoadjuvant chemotherapyParameterspCR Median (IQR)Non-pCR Median (IQR)PAUC (95% CI)Pre-SUVmax14.8 (9.2–17.7)14.4 (10.7–19.8)0.6040.454 (0.285–0.624)Post-SUVmax1.8(1.5–2.1)2.0 (1.6–3.4)0.2370.603 (0.460–0.746)ΔSUVmax (%)87.32 (81.5–91.8)88.6(82.8–91.8)0.9540.506 (0.329–0.682)Pre-TNR8.0 (5.3–9.2)7.3(5.9–10.2)0.7570.472 (0.297–0.647)Post-TNR1.7(1.0–1.1)1.2 (1.0–2.4)0.0980.640 (0.506–0.774)ΔTNR (%)87.3 (78.3–89.1)79.8 (62.7–86.7)0.1130.638 (0.472–0.803)pCR, pathological complete response; IQR, interquartile range; AUC, area under the curve; CI, confidence interval, SUV, standardized uptake value; TNR, tumor-to-normal-tissue ratio.Table 2.Diagnostic accuracy of post-TNR according to estrogen receptor status Sensitivity (%)Specificity (%)Accuracy (%)PPV (%)NPV (%)ER-positive85.739.447.523.192.9ER-negative10058.375.061.5100TNR, tumor-to-normal-tissue ratio; ER, estrogen receptor; PPV, positive predictive value; NPV, negative predictive value

Conclusion: In DbPET, ΔSUVmax and post-TNR were shown to be promising parameters for predicting pathological response to NAC. Post-TNR provided the highest sensitivity for predicting pCR in patients with ER-negative breast cancer.

Citation Format: Suzuki E, Sasada S, Sueoka S, Masumoto N, Goda N, Kajitani K, Emi A, Haruta R, Kadoya T, Kataoka T, Okada M. Diagnostic performance of dedicated breast PET for the prediction of pathological response after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-02-09.

Abstract P6-02-17: Hand-held impulse-radar detector for breast cancer: development and a pilot study

Background: Microwave breast imaging, which using the difference in the dielectric properties between breast cancer and normal breast tissue, is a painless and non-radiation method. We have created a novel hand-held prototype of breast cancer detector using impulse-radar based imaging system, and conducted a pilot clinical study.

Methods: The detector consists of complementary metal-oxide-semiconductor (CMOS) integrated circuits covering the ultrawideband width from 3.1 to 10.6 GHz, which enable the generation and transmission of Gaussian monocycle pulse (GMP) trains and single port eight throw switching matrices (SP8T-SW) for controlling a 4×4 cross-shaped dome antenna array. The size of the detector was 19.1 × 17.7 × 18.8 cm. After evaluation using a breast tumor phantom and the resected breast specimens obtained through mastectomy, we recruited 5 patients with histologically confirmed breast cancers in the clinical study. The detector was placed on the breast with the patient in a supine position. The primary endpoint was a detection rate of breast cancers, and the secondary endpoints were positional accuracy and adverse event. This study was registered with the UMIN Clinical Trials Registry (UMIN000026181).

Results: The three-dimensional positions of the tumors in the imaging results using a phantom and resected specimens are consistent with the results of histopathology analysis. In the clinical study, all 5 targeted breast cancers were detected and were visualized at the sites confirmed by other diagnostic modalities. Among 5 tumors, one was not detected via mammography because of heterogeneously dense breast and another was a microinvasive carcinoma of invasive tumor size 0.5 mm. No study-related adverse events occurred.

Conclusions: We succeeded in creating a new device of hand-held impulse-radar detector for breast cancer. The detector has sufficient detective capability, is safe for clinical use, and might detect an early stage breast cancer. In the future, we will proceed with the development to clinical application.

Citation Format: Sasada S, Masumoto N, Song H, Goda N, Kajitani K, Emi A, Kadoya T, Arihiro K, Kikkawa T, Okada M. Hand-held impulse-radar detector for breast cancer: development and a pilot study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-02-17.

Recurrent Epstein-Barr Virus-positive (EBV+) Primary Central Nervous System Lymphoma (PCNSL) in a Patient with Clinical Features of Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids (CLIPPERS)

Primary central nervous system lymphoma (PCNSL) and chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) can share clinical features and may be indistinguishable, even after brain biopsy. We encountered a case of Epstein-Barr virus-positive (EBV+) PCNSL recurrence in a patient with clinical features of CLIPPERS, and repeat brain biopsy was required to reach the correct diagnosis. Four years after the initial diagnosis and treatment of PCNSL, "peppering" punctate enhanced lesions with transient steroid responsiveness were detected during brain magnetic resonance imaging (MRI). A second brain biopsy supported a diagnosis of CLIPPERS, while a third biopsy confirmed the diagnosis of recurrent PCNSL.

Abstract P5-02-03: Evaluation of pathological malignancy grade and neoplastic progress of breast cancer using dedicated breast positron emission tomography

Background: Dedicated breast positron emission tomography (DbPET)provides detailed high resolution images of the breast and enables quantitative assessment using standard uptake values (SUVs). We aimed to determine whether DbPET can predict the pathological malignancy grade and neoplastic progress of breast cancer compared with whole body (WB) PET.

Methods: We investigated 196 consecutive patients with invasive breast cancerwho underwent concurrent Db- and WB-PET from January 2016 to March 2017. All Db- and WB-PET were quantified based on SUVs. We also investigated pathological features of breast cancer who had a ring-like uptake (RU) without central FDG accumulation on DbPET.

Results:

The associations between the SUVs for DB- and WB-PET and the pathological factors in breast cancerCharacteristicSUV WBPETDbPET Mean ± SDpMean ± SDpall3.6 ± 3.4 9.4±7.9 Tumor size    ≤2.0 cm2.2±1.6<0.0016.5±5.2<0.001>2.0 cm5.5±4.1 13.3±9.2 LN    Negative3.1±3.3<0.0018.4±7.8<0.001Positive4.9±3.2 11.8±7.7 NG    1 or 22.4±2.1<0.0016.6±5.9<0.00135.1±4.0 12.7±8.7 Ki67    < 201.8±1.1<0.0015.2±3.3<0.001≥ 204.4±3.7 11.4±8.6 ER    positive3.4±3.30.028.8±7.60.006negative5.2±3.6 13.5±8.6 HER-2    positive4.6±3.10.0911.8±7.60.04negative3.4±3.4 9.0±7.9 Sub type vs Lumnal A vs Lumnal ALuminal A1.8±1.1 5.2±3.3 Luminal B4.0±3.8<0.00110.1±8.5<0.001HER24.6±3.1<0.00111.8±7.6<0.001Triple negative5.3±3.8<0.00113.8±9.2<0.001

summarizes the association between SUVs for Db- and WB-PET and pathological factors inbreast cancer.SUVs on PET were significantly higher for the tumor size of >2.0 cm than for tumor size ≤2.0 cm (p<0.001), for LN-positive than for LN-negative (p<0.001), for NG3 than for NG1-NG2 (p<0.001), for higher Ki67 expression than for lower Ki67 expression (p<0.001), and for ER-negative than for ER-positive (WBPET, p=0.02; DbPET, p=0.006). SUVs were significantly lower for Luminal A than for Luminal B, HER2, and triple-negative cancer (p<0.001 for all three).SUVs for DbPET was significantly higher for HER2-positive than for HER2-negative (p=0.02).

The association between SUVs for breast cancer with and without RU on DbPETCharacteristicRU(-), nRU(+), npall17323 Tumor size   ≤2.0 cm1095<0.001>2.0 cm6418 LN   Negative1299<0.001Positive4414 NG   1 or 210070.0237316 Ki67   < 206130.03≥ 2011220 ER   positive152190.49negative214 HER-2   positive2620.38negative14721 Sub type  vs Lumnal ALuminal A493 Luminal B84150.02HER22620.81Triple negative1430.04

summarizes the association between SUVs for breast cancer with and without RU on DbPET. SUVs for breast cancer with RU on DbPET were significantly higher for the tumor size of >2.0 cm than for tumor size ≤2.0 cm, for LN -positive than for LN-negative (p<0.001), for NG3 than for NG1-2 (p=0.02), and for higher Ki67 expression than for lowerKi67 expression (p=0.03). SUVs were significantly lower for Luminal A than for Luminal B (p=0.02) and triple-negative cancer (p=0.04).

Conclusions: SUVs for DbPET were equal or superiorto WBPET in predicting the pathological malignancy grade and neoplastic progress in tumors. Furthermore, the presence of RU on DbPET can provide excellent predictive value for high-grade malignancy and might help to determine appropriate therapeutic strategies.

Citation Format: Masumoto N, Kadoya T, Nishina M, Kimura Y, Suzuki E, Sueoka S, Goda N, Sasada S, Kajitani K, Emi A, Haruta R, Kataoka T, Okada M. Evaluation of pathological malignancy grade and neoplastic progress of breast cancer using dedicated breast positron emission tomography [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-02-03.

Abstract P6-03-08: Detection ability of dedicated breast positron emission tomography for small-sized breast cancer

Background: Whole body (WB) 18F-fluorodeoxyglucose positron emission tomography (PET) has a relatively poor spatial resolution (>1 cm), which limits the capability to detect small lesions. Therefore, small-sized breast cancers (≤1 cm) may not be visible on WBPET. To overcome these limitations, dedicated breast PET (DbPET) has been developed to improve spatial resolution. DbPET enables detailed high-resolution images within the breast. We aimed to determine whether DbPET can detect small-sized breast cancer compared to WBPET.

Methods: We investigated 203 consecutive patients (217 tumors) (T1–3, N0–3a, M0) with breast cancer who underwent concurrent DbPET and WBPET between January 2016 and March 2017. All DbPET and WBPET images were semi-quantified based on standard uptake values. The diagnostic performance of each scanner was assessed in DbPET and WBPET. Tumors were classified based on pathological classification as follows: Tis, ductal carcinoma in situ (DCIS); T1a, ≤0.5 cm; T1b, 0.5–1 cm; and T1c, 1–2 cm; T2, 2–5 cm; T3, >5 cm. The sensitivities of DbPET and WBPET were compared in each size group.

Results: Table 1 shows the detection rate of breast cancer in WBPET and DbPET

The detection rate of breast cancer in WB- and Db-PET DbPETWBPETpTumor sizeDetection (-) n(%)Detection (+) n(%)Detection (-) n(%)Detection (+) n(%) Tis6(14.6)35(85.4)18(43.9)23(56.1)0.0030T1a2(8)23(92)7(28)18(72)0.0594T1b2(6.5)29(93.5)10(32.3)21(67.7)0.0077T1c5(8.2)56(91.8)11(18)50(82)0.1038T20(0)57(100)1(1.8)56(98.2)0.2375T30(0)2(100)0(0)2(100)-total15(6.9)202(93.1)47(21.7)170(78.3)<0.0001

. The overall detection rate in DBPET [93.1% (202/217)] was significantly higher than that of WBPET [78.3% (170/217)] (P < 0.001). For smaller tumors, DbPET was more sensitive than WBPET: Tis (85.4% vs. 56.1%), T1a (92% vs. 72%), T1b (93.5% vs. 67.7%), T1c (91.8% vs. 82%), T2 (100% vs. 98.2%), and T3 (100% vs. 100%). The sensitivity of DbPET was significantly higher than that of WBPET in Tis (P = 0.003) and T1b (P = 0.008) and tended to be higher than that of WBPET in T1a (P = 0.059). Conversely, no significant differences were observed in T1c (P = 0.103) and T2 (P = 0.238).

Conclusion: The imaging sensitivity of DbPET was higher than that of WBPET. DbPET showed significant sensitivity in DCIS and tumors ≤1 cm, which is a weak point for WBPET. DbPET may serve as a new diagnostic modality to detect small-sized breast cancer.

Citation Format: Sueoka S, Masumoto N, Nishina M, Kimura Y, Suzuki E, Goda N, Sasada S, Kajitani K, Emi A, Haruta R, Kadoya T, Kataoka T, Okada M. Detection ability of dedicated breast positron emission tomography for small-sized breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-03-08.

Polymorphism in microRNA-binding site in HNF1B influences the susceptibility of type 2 diabetes mellitus: a population based case-control study

Background

Recent genome-wide association studies (GWAS) have identified many SNPs associated with type 2 diabetes mellitus (T2DM). However, the functional roles for most of the SNPs have not been elucidated. MicroRNAs (miRNAs) are key regulators of gene expression involved in the development and progression of various diseases including T2DM. In this study, we investigated whether commonly occurring SNPs modulate miRNA-directed regulation of gene expression, and whether such SNPs in miRNA-binding sites are associated with the susceptibility for T2DM.

Methods

Genotypes of eleven 3′ untranslated region (UTR) SNPs of seven susceptibility genes for T2DM were determined in 353 T2DM patients and 448 control subjects. In addition, the interactions of miRNAs with the 3′UTR in the hepatocyte nuclear factor 1β (HNF1B) gene were investigated using luciferase reporter assays.

Results

One 3′UTR SNP (rs2229295) in the HNF1B gene was significantly associated with T2DM, and the frequency of an A allele (rs2229295) in T2DM patients was decreased compared with that in controls. Luciferase reporter assays showed that the SNP (rs2229295) altered the binding of two miRNAs (hsa-miR-214-5p and hsa-miR-550a-5p).

Conclusions

We have detected the interactions of hsa-miR-214-5p/hsa-miR-550a-5p and the 3′UTR SNP of the HNF1B gene by in vitro luciferase reporter assays, and propose that the binding of such miRNAs regulates the expression of the HNF1B gene and the susceptibility of T2DM.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-015-0219-5) contains supplementary material, which is available to authorized users.

Adipose tissue hypoxia induces inflammatory M1 polarity of macrophages in an HIF-1α-dependent and HIF-1α-independent manner in obese mice

AIMS/HYPOTHESIS

As obesity progresses, adipose tissue exhibits a hypoxic and inflammatory phenotype characterised by the infiltration of adipose tissue macrophages (ATMs). In this study, we examined how adipose tissue hypoxia is involved in the induction of the inflammatory M1 and anti-inflammatory M2 polarities of ATMs.

METHODS

The hypoxic characteristics of ATMs were evaluated using flow cytometry after the injection of pimonidazole, a hypoxia probe, in normal-chow-fed or high-fat-fed mice. The expression of hypoxia-related and inflammation-related genes was then examined in M1/M2 ATMs and cultured macrophages.

RESULTS

Pimonidazole uptake was greater in M1 ATMs than in M2 ATMs. This uptake was paralleled by the levels of inflammatory cytokines, such as TNF-α, IL-6 and IL-1β. The expression level of hypoxia-related genes, as well as inflammation-related genes, was also higher in M1 ATMs than in M2 ATMs. The expression of Il6, Il1β and Nos2 in cultured macrophages was increased by exposure to hypoxia in vitro but was markedly decreased by the gene deletion of Hif1a. In contrast, the expression of Tnf, another inflammatory cytokine gene, was neither increased by exposure to hypoxia nor affected by Hif1a deficiency. These results suggest that hypoxia induces the inflammatory phenotypes of macrophages via Hif1a-dependent and -independent mechanisms. On the other hand, the expression of inflammatory genes in cultured M2 macrophages treated with IL-4 responded poorly to hypoxia.

CONCLUSIONS/INTERPRETATION

Adipose tissue hypoxia induces an inflammatory phenotype via Hif1a-dependent and Hif1a-independent mechanisms in M1 ATMs but not in M2 ATMs.

Allelic diversity of the MHC class II DRB genes in brown bears (Ursus arctos) and a comparison of DRB sequences within the family Ursidae

The allelic diversity of the DRB locus in major histocompatibility complex (MHC) genes was analyzed in the brown bear (Ursus arctos) from the Hokkaido Island of Japan, Siberia, and Kodiak of Alaska. Nineteen alleles of the DRB exon 2 were identified from a total of 38 individuals of U. arctos and were highly polymorphic. Comparisons of non-synonymous and synonymous substitutions in the antigen-binding sites of deduced amino acid sequences indicated evidence for balancing selection on the bear DRB locus. The phylogenetic analysis of the DRB alleles among three genera (Ursus, Tremarctos, and Ailuropoda) in the family Ursidae revealed that DRB allelic lineages were not separated according to species. This strongly shows trans-species persistence of DRB alleles within the Ursidae.

Wiener Filter-Magnetoencephalography of Visual Cortical Activity

This paper reports a revised Wiener filter to resolve the inverse problem for magnetoencephalograms (MEGs) according to the structural and functional constraints based on magnetic resonance imaging (MRI) and functional magnetic resonance imaging (fMRI). Wiener filter-MEG imaging for half field stimulation with the chromatic stimulus resolved fast, slow and late responses in V1, V4 and the inferotemporal cortex, respectively. The time courses of these responses were roughly comparable with those reported by unit recording studies of the corresponding monkey visual cortical areas. Wiener filter-MEG imaging had comparable spatial resolution and better signal to noise ratio than fMRI. The background noise was robust in fMRI responses, but became virtually eliminated in Wiener filter responses. Wiener filter-MEG imaging with upper and lower quadrant field stimulation demonstrated V1 responses differentially distributed respectively in the lower and upper banks of the calcarine sulcus. These results demonstrate that responses in two cortical areas facing close to each other can be resolved by Wiener filter-MEG. The present method provides a way to image brain activities with millisecond- and millimeter-order spatiotemporal resolution.

Sensitivity to modulation of color distribution in multicolored textures

We evaluated the discriminability of color distributions in square-element textures. Each texture contained 225 colors, represented by a distribution of color vectors in color space defined by the L-M and S-(L+M) axes. Each color distribution was systematically manipulated by modulating the distribution of the vector lengths sinusoidally as a function of the direction in the color space. The results showed that it is difficult to resolve a color distribution modulated in more than three cycles per 360 degrees in the chromatic direction. The difference in components along the cardinal axes is not a critical factor in the discrimination of the color distribution. An analysis using a line-element model suggested that the discrimination of the color distribution is mediated by multiple chromatic channels that are tuned to a variety of directions in the color space with a half-height-half-bandwidth of about 40 degrees in the chromatic direction.

Altered expression of heme oxygenase-1 in the livers of patients with portal hypertensive diseases

This study was designed to determine changes in expression of heme oxygenase (HO)-1, the stress-inducible and carbon monoxide-producing enzyme, in normotensive and portal hypertensive human livers. GTS-1, a monoclonal antibody against rat HO-1 cross-reacted with the human HO-1 and blocked its enzyme activity, allowing us to examine the activity and localization of HO-1. In controls, approximately 50% of the total HO activity was from HO-1 as judged by the sensitivity to GTS-1, while the rest of activity was from other isozymes such as HO-2. HO-1 was expressed mainly in a subpopulation of Kupffer cells, and the expression in hepatic stellate cells, sinusoidal endothelial cells, and hepatocytes was little, if any. The HO-1 expression exhibited quite different pictures in the livers of portal hypertensive diseases. In cirrhotic livers, which undergo portal hypertension through increases in intrasinusoidal resistance and regenerative changes in the parenchyma, HO-1 occurred in a majority of Kupffer cells and was also observed in hepatocytes. Consequently, the total HO-1 activities became significantly greater in these tissues than those from normal individuals. By contrast, livers of idiopathic portal hypertension that are characterized by an increase in presinusoidal resistance displayed a significant decrease in the HO-1 expression in Kupffer cells, and its hepatocellular expression was not detectable. Although factors involved in altered HO-1 expression in these cells remain unknown, the results suggest that Kupffer cells could alter their expression of HO-1 in response to local hemodynamic changes associated with chronic portal hypertension in humans.

Cloning and characterization of the promoter of murine cytohesin-1 gene

Mouse cytohesin-1 (CTH-1) is a guanine nucleotide exchange factor, specific for ADP ribosylation factors. The CTH-1 gene promoter was characterized by deletion mapping and mutational analysis. The region between -101 and -38 relative to the transcription start site showed the essential promoter activity when transfected into both NIH3T3 and COS7 cells. The nucleotides of the core promoter region contain three tandem GC boxes, which can offer potential binding sites for the ubiquitous transcription factor Sp-1 family. Mutational analysis revealed that these tandem GC boxes are indispensable for activation of the gene transcription.

Structure and sequence of the mouse V1a and V1b vasopressin receptor genes

The structural organization and 5'-flanking region of the mouse V1a and V1b vasopressin receptor genes were determined. The mouse V1a receptor gene was located within an 8-kb XbaI fragment, and the mouse V1b receptor gene was located within a 14-kb EcoRV fragment. Both genes were comprised of two coding exons that were separated by a 2.3-kb and a 8.0-kb intron, respectively, located before the respective seventh transmembrane domain of the receptor sequence. The availability of these genes would allow us to study the functional role of V1a and V1b receptors by disrupting the gene in mice.

Carbon monoxide overproduced by heme oxygenase-1 causes a reduction of vascular resistance in perfused rat liver

This study aimed to examine whether livers overexpressing heme oxygenase (HO)-1 could alter the vascular resistance through the vasorelaxing action of carbon monoxide (CO). The relationship among HO-1 expression, CO generation, and the vascular resistance was assessed in perfused rat livers pretreated with hemin, an inducer of HO-1. At 18 h after the hemin treatment, livers displayed marked increases in HO-1 expression in hepatocytes and venous CO flux and a reduction of the basal resistance. The reduction of the resistance in hemin-treated livers was canceled by administration of oxyhemoglobin, a reagent trapping both CO and nitric oxide (NO), but not by methemoglobin, which captures NO but not CO. Liposome-encapsulated oxyhemoglobin, which cannot access the space of Disse, did not cause vasoconstriction. Furthermore, these livers became less sensitive to endothelin-1, a vasoconstrictive peptide, than the untreated controls through mechanisms involving CO. On the other hand, at 12 or 24 h after the treatment when the HO-1 induction was not accompanied by CO overproduction, neither a decrease in the basal resistance nor vascular hyporeactivity to endothelin-1 was observed. These results suggest that CO overproduced in the extrasinusoidal compartment is a determinant of the HO-1-mediated vasorelaxation in the liver.

Characterization of the mouse alpha1D-adrenergic receptor gene

Alpha1-adrenergic receptors (alpha1-ARs) play critical roles in the regulation of a variety of physiological processes. Increasing evidence suggests that multiple receptor subtypes of alpha1-ARs regulate these physiological processes. Molecular cloning has identified three distinct cDNAs encoding alpha1-AR subtypes (alpha1A, alpha1B and alpha1D) that are structurally homologous. Among the alpha1-AR subtypes, the function of the alpha1D-AR remains unclear. In order to examine the physiological role of alpha1D-AR, we cloned and characterized a gene for the mouse alpha1D-AR. Using a mouse alpha1D-AR cDNA as a probe, we isolated the gene for the mouse alpha1D-AR from a mouse genomic library. The alpha1D-AR consists of two exons and an intron that interrupts the coding region of the putative sixth transmembrane domain. The 5'-flanking region of exon 1 contains neither a TATA box nor a CAAT box but is high in GC content and contains several Sp1 binding sites (GC boxes). This pattern is similar to promoters described for other members of alpha1-ARs. The untranslated region also contains putative cyclic AMP response elements. Isolation of this gene will allow further investigation, via gene knock-outs and deletion mutants, of the mechanisms of transcriptional regulation and a greater understanding of the physiological role of alpha1D-AR.

Discontinuous total parenteral nutrition prevents postischemic mitochondrial dysfunction in rat liver

Although discontinuous total parenteral nutrition (d-TPN) has recently been favored for clinical use over continuous total parenteral nutrition (c-TPN) to ameliorate liver dysfunction, mechanisms for the protection against postoperative liver dysfunction remain unknown. This study aimed to examine differences in mitochondrial function in d-TPN- and c-TPN-pretreated livers during ischemia-reperfusion. Rat livers pretreated with d-TPN or c-TPN were perfused with Krebs-Ringer buffer and were exposed to 25% low-flow hypoxia followed by reperfusion. Intrahepatic mitochondrial membrane potential (triangle up) and cell viability were assessed by dual-color digital microfluorography using rhodamine 123 (Rh123) and propidium iodide (PI), respectively. In response to hypoxia, livers pretreated with c-TPN, d-TPN, and an ordinary chow diet exhibited a significant triangle up reduction among the entire lobules. Upon reperfusion, the regional triangle up values further decreased in the c-TPN liver, whereas those in the d-TPN-treated or chow-treated livers displayed a rapid recovery toward the control levels. The severity of cell injury did not differ among the groups, showing that the reperfusion-induced triangle up drop in the c-TPN-pretreated liver is not a consequence of cell injury. Differences in the triangle up drop among the groups appear to occur irrespective of those in the glycogen storage, because the livers undergoing d-TPN display a marked triangle up recovery even when reperfused at the end of a fasted state. These results indicate that c-TPN, but not d-TPN, jeopardizes mitochondrial re-energization and suggest that a circadian pattern of the TPN serves as a potentially beneficial strategy to reduce the risk of postischemic mitochondrial dysfunction in the liver.

Carbon monoxide as a regulator of bile canalicular contractility in cultured rat hepatocytes

This study aimed to examine the mechanism(s) by which carbon monoxide (CO), a product of heme oxygenase reaction, controls the contractility of bile canaliculus (BC) in hepatocytes. When BCs associated with the couplet cells in cultured rat hepatocyte suspension were observed using time-lapse video microscopy, they exhibited periodical contractions with a most-probable interval of 6 minutes under our experimental conditions. The addition of 1 micromol/L zinc protoporphyrin IX (ZnPP), a potent inhibitor of heme oxygenase, to the culture medium elicited a 40% shortening of the interval time together with an increase in intracellular calcium concentrations, while the same concentration of iron protoporphyrin IX did not induce such changes. The production of CO, which was 0.5 nmol/h/10(8) cells in the absence of ZnPP, diminished to less than 0.1 nmol/h/10(8) cells upon application of ZnPP. The ZnPP-elicited increases in both contractile frequency and intracellular calcium concentrations were attenuated by the addition of 1 micromol/L CO or 50 micromol/L 1,2-bis(2-aminophenoxy) ethane-tetraacetate, a calcium chelator. Clotrimazole or metyrapone, inhibitors of cytochrome P450-dependent monooxygenase activities, also attenuated the ZnPP-induced elevation of the contractile frequency. On the other hand, intracellular cyclic guanosine monophosphate (cGMP) contents were not altered significantly by the application of ZnPP or by CO. These results indicate that CO generated by heme oxygenase controls the BC function by changing intracellular calcium concentrations presumably through a mechanism involving the cytochrome P450 reaction.

Moving stimuli define the shape of stationary chromatic patterns

A study is reported of phenomena involved in perceptually unified organisation of a stationary chromatic pattern and a moving black outline or dot pattern. When the corners of the outline pattern were temporally oscillated on a stationary chromatic square, the chromatic border appeared to follow the moving outline, as if captured by it. This capture effect was also observed with moving dots: the chromatic border was defined by an imaginary line connecting the moving dots. Both capture effects occur over a region that becomes wider with increasing velocity of the oscillation. These observations suggest that the visual system effectively uses information from moving features to define the shape of overlapping chromatic image regions.

Distribution of heme oxygenase isoforms in rat liver. Topographic basis for carbon monoxide-mediated microvascular relaxation

Carbon monoxide (CO) derived from heme oxygenase has recently been shown to play a role in controlling hepatobiliary function, but intrahepatic distribution of the enzyme is unknown. We examined distribution of two kinds of the heme oxygenase isoforms (HO-1 and HO-2) in rat liver immunohistochemically using monoclonal antibodies. The results showed that distribution of the two isoforms had distinct topographic patterns: HO-1, an inducible isoform, was observed only in Kupffer cells, while HO-2, a constitutive form, distributed to parenchymal cells, but not to Kupffer cells. Both isoforms were undetectable in hepatic stellate cells and sinusoidal endothelial cells. Of the two isoforms, HO-2 in the parenchymal cell rather than HO-1 in the Kupffer cell, appears to play a major role in regulation of microvascular tone. In the perfused liver, administration of HbO2, a CO-trapping reagent that can diffuse across the fenestrated endothelium into the space of Disse, elicited a marked sinusoidal constriction, while administration of a liposome-encapsulated Hb that cannot enter the space had no effect on the microvascular tone. These results suggest that CO evolved by HO-2 in the parenchymal cells, and, released to the extrasinusoidal space, served as the physiological relaxant for hepatic sinusoids.

Luminance and Colour Cues in Perceptual Transparency

A series of experiments was carried out to determine the dependence of the perception of transparency on colour relationships in a four-region pattern comprising two non-overlapping regions, an overlapping region, and a background. The proportion of trials where the pattern was perceived as transparent, and the relative layering in depth of the two perceived surfaces, were determined as a function of the luminance of colour of the overlapping region while those of the non-overlapping regions were kept constant. It was found that perceptual transparency could arise from displays where the four regions were isoluminant but different in colour. The function obtained for isoluminant colour-varying patterns was quite similar to that obtained for isochromatic luminance-varying patterns. In both types of patterns, the background condition strongly affected perceptual transparency and perceived depth order in a similar way. These results suggest that perceptual transparency for both the isochromatic and the isoluminant pattern was specified in a common manner by contrast relations in a certain region of the image, and was not always constrained by the physics of transparency. The dependence of perceptual transparency on the contrast relation may be accounted for by mechanisms incorporating the filling-in process associated with antagonistic luminance and opponent-colour responses.

Endogenous carbon monoxide suppression stimulates bile acid-dependent biliary transport in perfused rat liver

This study aimed to investigate whether carbon monoxide (CO), a product of heme oxygenase that degrades protoheme IX, serves as an endogenous modulator for biliary transport. To that end, effects of zinc protoporphyrin IX (ZnPP), a heme oxygenase inhibitor, on the biliary transport were tested in perfused rat liver. Perfusion of 1 microM ZnPP abolished detectable levels of CO in the venous perfusate and increased bile acid-dependent bile output accompanying an increased secretion of bile salts. The ZnPP-induced choleresis coincided with a reduction of tissue guanosine 3',5'-cyclic monophosphate (cGMP) levels and a decrease in vascular conductance. On administration of 2.5 microM CO, ZnPP-elicited choleresis, decreases in vascular conductance, and cGMP levels were all attenuated. Treatment with 1 microM 8-bromoguanosine 3',5'-cyclic monophosphate (8-BrcGMP) partly attenuated the ZnPP-induced choleresis in concert with repression of vascular conductance. Furthermore, treatment of the liver with methylene blue, a guanylate cyclase inhibitor, evoked a choleresis similar to that induced by ZnPP. Thus endogenous CO suppression stimulates the biliary transport in part through a cGMP-dependent mechanism.

Additive effect of luminance and color cues in generation of neon color spreading

A series of experiments were designed to examine how luminance and color cues influence the occurrence of neon color spreading for the Ehrenstein pattern plus the cross pattern. The proportion of "see" responses for color spreading was obtained for different combinations of the luminance and color of the pattern components. The following were obtained. (1) Increase in the luminance of the inducing pattern and/or the color difference between the cross and the inducing pattern raised the proportion of "see" responses for color spreading. This implies that luminance and color signals additively contribute to the generation of the color spreading, but in different ways. (2) The "iso-spreading contours" for the generation of color spreading were determined on the two-dimensional isoluminant plane composed of the L-M and S-(L+M) axes. The contours were approximately described by rotated quadratic or ellipse functions. The additive interaction within the chromatic systems [the L-M system and the S-(L+M) system] was less significant than that across the luminance and chromatic systems. (3) The pattern of the experimental results could not be explained straightforwardly by existing models.

Modulation of mitochondrion-mediated oxidative stress by nitric oxide in human placental trophoblastic cells

Intracellular hydroperoxide generation in cultured human placental trophoblastic cells (HPTCs) was quantitatively monitored in the presence or absence of an NO synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME, 1 mM), by digital microfluorography with use of carboxydichlorofluorescein, a hydroperoxide-sensitive fluorogenic probe. In the absence of L-NAME, HPTCs displayed a time-dependent gradual elevation of the fluorescence, suggesting the ability to produce oxidants spontaneously. In the presence of L-NAME, however, the fluorescent response in these cells increased further; the oxidative impact elicited by L-NAME treatment for 30 min was equivalent to that induced by application of 230 microM tert-butyl hydroperoxide for 5 min. This oxidative process was completely blocked by rotenone, a reagent that interferes with electron entry into complex I of the mitochondrial respiratory chain. On the other hand, antimycin A, which blocks mitochondria at the distal site of the ubiquinone pool, potentiated the L-NAME-induced oxidative change. These findings suggest that constitutive levels of nitric oxide production contribute to regulation of mitochondrion-derived intracellular oxidant generation in HPTCs.

Carbon monoxide: an endogenous modulator of sinusoidal tone in the perfused rat liver

Heme oxygenase is a heme-oxidizing enzyme which generates biliverdin and carbon monoxide (CO). The present study was designed to elucidate whether CO endogenously produced by this enzyme serves as an active vasorelaxant in the hepatic microcirculation. Microvasculature of the isolated perfused rat liver was visualized by dual-color digital microfluorography to alternately monitor sinusoidal lining and fat-storing Ito cells. In the control liver, the CO flux in the venous effluent ranged at 0.7 nmol/min per gram of liver. Administration of a heme oxygenase inhibitor zinc protoporphyrin IX (1 microM) eliminated the baseline CO generation, and the vascular resistance exhibited a 30% elevation concurrent with discrete patterns of constriction in sinusoids and reduction of the sinusoidal perfusion velocity. The major sites of the constriction corresponded to local sinusoidal segments colocalized with Ito cell which were identified by imaging their vitamin A autofluorescence. The increase in the vascular resistance and sinusoidal constriction were attenuated significantly by adding CO (1 microM) or a cGMP analogue 8-bromo-cGMP (1 microM) in the perfusate. From these findings, we propose that CO can function as an endogenous modulator of hepatic sinusoidal perfusion through a relaxing mechanism involving Ito cells.

Carbon monoxide as an endogenous modulator of hepatic vascular perfusion

Carbon monoxide (CO) generated by heme oxygenase has recently been considered a neural messenger in brain. This observation prompted us to investigate whether CO participates in vascular regulation in the liver, another organ with high levels of heme oxygenase activity. In isolated perfused rat liver, submicromolar levels of CO were detectable in the effluent and were able to be suppressed by the administration of Zn protoporphyrin IX (1 microM), a potent inhibitor of heme oxygenase. Furthermore, zinc protoporphyrin IX (1 microM) promoted an increase in the perfusion pressure under the constant flow conditions. These changes were reversed by adding CO (2 microM) or a cGMP analogue 8-bromo-cGMP (1 microM) in the perfusate. The present findings indicate that CO can function as an endogenous modulator of vascular perfusion in the liver.