KLF4 Mutation Shapes Pathologic Characteristics of Foveolar-Type Gastric Adenoma in Helicobacter pylori-Naive Patients.

Along with a recent remarkable decrease in Helicobacter pylori-infected individuals, reports of gastric neoplasms such as sporadic foveolar-type gastric adenoma (FGA) in H. pylori-naive patients have been increasing. This tumor, with its raspberry-like appearance, is common in H. pylori-naive gastric mucosa. The current study investigated the genomic features of sporadic FGA. Fresh-frozen sporadic FGA tissue samples from H. pylori-naive patients were subjected to whole genome analysis using a next-generation sequencer. Proliferation ability and apoptotic profiles of human gastric epithelial cells, along with plasmid transfection of candidate variants, were examined. A mean of 6.65 × 108 total reads were obtained for each sample. Common genetic abnormalities in well-known proliferation driver genes of conventional gastric dysplasia/cancer were not found. However, a common single-nucleotide variation (SNV) was noted within the DNA-binding domain of the tumor suppressor gene KLF4. This novel SNV was located in the zinc finger 2 region. Additional experiments showed that it significantly suppressed proliferation of gastric epithelial cells compared with wild-type KLF4 plasmid-transfected cells, although suppression was reduced in early apoptotic phase-related genes. A novel SNV in the KLF4 zinc finger 2 region was commonly found in sporadic FGA tissue samples, which may explain the slow-growing properties of this neoplasm.

Thyroid crisis caused by metastatic thyroid cancer: an autopsy case report.

BACKGROUND: Thyroid crisis is a life-threatening condition in thyrotoxic patients. Although differentiated thyroid cancer is one of the causes of hyperthyroidism, reports on thyroid crisis caused by thyroid cancer are quite limited. Here, we describe a case of thyroid crisis caused by metastatic thyroid cancer. CASE PRESENTATION: A 91-year-old woman was admitted to our hospital because of loss of appetite. Two years prior to this hospitalization, she presented with subclinical thyrotoxicosis and was diagnosed with histologically unidentified thyroid cancer with multiple metastases, and she refused aggressive medical interventions. On admission, she exhibited extreme thyrotoxicosis, and the presence of fever, severe tachycardia, impaired consciousness, and heart failure revealed the presence of thyroid crisis. All thyroid autoantibodies were negative. Multidisciplinary conservative treatment was initiated; however, she died on the fifth day after admission. Autopsy revealed the presence of primary anaplastic thyroid carcinoma and multiple metastatic foci arising from follicular thyroid carcinoma. Both primary and metastatic follicular thyroid carcinoma likely induced thyrotoxicosis, which could have been exacerbated by anaplastic thyroid carcinoma. CONCLUSIONS: Even though the trigger of thyroid crisis in this patient is not clear, the aggravated progression of her clinical course suggests that careful monitoring of thyroid hormones and appropriate intervention are essential for patients with thyroid cancer.

Identification of Molecular Basis for Objective Discrimination of Breast Cancer Cells (MCF-7) from Normal Human Mammary Epithelial Cells by Raman Microspectroscopy and Multivariate Curve Resolution Analysis.

Raman spectroscopy (RS), a non-invasive and label-free method, has been suggested to improve accuracy of cytological and even histopathological diagnosis. To our knowledge, this novel technique tends to be employed without concrete knowledge of molecular changes in cells. Therefore, identification of Raman spectral markers for objective diagnosis is necessary for universal adoption of RS. As a model study, we investigated human mammary epithelial cells (HMEpC) and breast cancer cells (MCF-7) by RS and employed various multivariate analyses (MA) including principal components analysis (PCA), linear discriminant analysis (LDA), and support vector machine (SVM) to estimate diagnostic accuracy. Furthermore, to elucidate the underlying molecular changes in cancer cells, we utilized multivariate curve resolution analysis-alternating least squares (MCR-ALS) with non-negative constraints to extract physically meaningful spectra from complex cellular data. Unsupervised PCA and supervised MA, such as LDA and SVM, classified HMEpC and MCF-7 fairly well with high accuracy but without revealing molecular basis. Employing MCR-ALS analysis we identified five pure biomolecular spectra comprising DNA, proteins and three independent unsaturated lipid components. Relative abundance of lipid 1 seems to be strictly regulated between the two groups of cells and could be the basis for excellent discrimination by chemometrics-assisted RS. It was unambiguously assigned to linoleate rich glyceride and therefore serves as a Raman spectral marker for reliable diagnosis. This study successfully identified Raman spectral markers and demonstrated the potential of RS to become an excellent cytodiagnostic tool that can both accurately and objectively discriminates breast cancer from normal cells.

Immunohistochemical expression of filaggrin is decreased in proton pump inhibitor non-responders compared with proton pump inhibitor responders of eosinophilic esophagitis.

BACKGROUND: Eosinophilic esophagitis (EoE) is an allergic gastrointestinal disease that features eosinophilic infiltration of esophageal mucosa, but the role of barrier dysfunction of the epithelium in its pathogenesis remains to be elucidated. Clinically, EoE is divided into proton pump inhibitor-non-responders (PPI-NR) and PPI-responders (PPI-R). Our main aims were to investigate the differences of expression of epidermal differential complex (EDC) proteins and desmoglein that are considered to play important roles in formation of the epidermal skin barrier between these two conditions and to seek the usefulness of the differences in pathological diagnosis. Conventional histopathological findings and allergic background were also compared. METHODS: Twenty-nine PPI-NR and 44 PPI-R were recruited, and 35 reflux esophagitis patients were also enrolled. After clinical information and histopathological findings were reviewed, immunohistochemical expression of EDC proteins (filaggrin, loricrin, and involucrin) and desmoglein in all three groups were examined and semi-quantitatively scored. RESULTS: Regarding allergic conditions, the prevalence of asthma was significantly higher in PPI-NR than in PPI-R. Other allergic conditions showed no differences. Histopathological findings did not exhibit the statistical difference between PPI-NR and PPI-R. However, immunostaining score of filaggrin in PPI-NR was significantly lower than in PPI-R, although the expressions of involucrin, loricrin and desmoglein demonstrated no differences. CONCLUSIONS: The results suggest a role of reduced filaggrin expression in the difference of effectiveness of PPI treatment between PPI-NR and PPI-R. Moreover, immunohistochemical determination of filaggrin expression in EoE patients could be informative in the clinical decision of how to treat the patients.

[Clinical Impact of First Metastasis Sites and Subtypes in the Outcome of Brain Metastases of Breast Cancer].

Brain metastasis(BM)is the final stage of metastatic breast cancer(MBC), but its course and outcomes after the first metastasis(FM)to various sites are not fully clarified. Furthermore, the survival of patients with BM appears to be improving with the recent development in MBC control according to the subtype analysis. The present study included 35 patients with BM between 2008 and 2018, and was designed to clarify the effects of the FM sites and subtypes on the outcome of these patients. Subtypes included 8 Luminal(L), 8 L-HER2+(LH), 8 HER2(H), and 11 triple-negative(TN)types, and FM sites included 14 lungs or pleurae, 4 livers, 4 brains, 4 bones, and 9 local or lymph node(LN)metastases. The median interval between FM and BM(IFB)was 33 months(M)for overall patients; 50M for LH, 37M for L, 22M for H, and 19M for TN (p=0.0463); and 24M for the high risk(HR)FM(lung, pleura, liver)and 47M for the low risk(LR)FM group(bone, local, LN)(p=0.0385). The median overall survival(OS)after BM diagnosis was 13M for overall patients; 27M for LH, 13M for H, 10M for L, and 5M for TN(p=0.0112). There were no significant differences in the OS after BM diagnosis between HR FM and LR FM patients. Multivariate analyses for OS after BM revealed that patients with HER2(+)and estrogen receptor(+) tumors had a significantly better survival(risk ratio[RR]=0.644, p=0.0413; RR=0.290, p=0.0251, respectively). Three patients are surviving longer than 10 years after BM, including 2 with L-type and 1 with LH-type tumors, and their FM sites were 1 local, 1 brain, and 1 liver. The present study indicated that subtypes and FM site(HR or LR)had significant impact on the clinical course and prognosis of patients with BM. Focusing on the subtypes and FM site can improve the early detection and treatment results of BM.

[Radiation-Associated Angiosarcoma That Developed in the Irradiated Residual Breast after Breast-Conserving Surgery for Breast Cancer-A Case Report and Review of the Literature].

We report a radiation-associated angiosarcoma(RAAS)of the breast, which is a rare but important complication after breast-conserving surgery(BCS)and radiotherapy(RT)for breast cancer. A7 2-year-old woman had undergone BCS for invasive ductal carcinoma of the right breast(pT2pN1M0, StageⅡB), followed by RT of 50 Gy; she was treated with doxifluridine and anastrozole for 5 year. She noticed a bloody cutaneous bulla in the right breast 64 months later, and the skin lesions gradually expanded. She was brought to our clinic for the treatment of massive bleeding from the skin lesions. Ulcer biopsy revealed cutaneous AS(cells were CD31[+], CD34[+], VEGF[-], and VEGF-R[+]). She underwent mastectomy and latissimus dorsal flap surgery. She died of local recurrence and liver metastasis 13 months later. RAAS is rare, but it should be considered in patients with skin lesions, such as erosion and bloody bulla, after BCS and RT for breast cancer. To our knowledge, only 12 cases of RAAS, including the present case, have been reported in Japan, and we reviewed the Japanese RAAS cases in comparison with those reported in the Western literature.

Is Asymptomatic Esophageal Eosinophilia the Same Disease Entity as Eosinophilic Esophagitis?

Eosinophilic esophagitis (EoE) is an allergic inflammatory disorder that is characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation.1,2 Its prevalence has been increasing rapidly in both Western and Asian countries. In Japan, most of the cases of esophageal eosinophilia (EE) are found in an upper endoscopy examination for gastric cancer screening performed during a comprehensive health check-up.3,4 Indeed, we frequently encounter patients with asymptomatic EE showing typical endoscopic findings, such as linear furrows, as well as histologic findings compatible with EoE. However, the current clinical guidelines for EoE diagnosis include symptoms related to esophageal dysfunction, thus patients without symptoms do not fulfill the diagnostic criteria.1,2 The clinical characteristics remain to be fully elucidated,5 thus we aimed to clarify clinical features of asymptomatic EE as compared with those of EoE.

Vitamin D-mediated hypercalcemia in multicentric Castleman's disease.

Multicentric Castleman's disease (MCD) is a rare lymphoproliferative disorder, which represents various symptoms caused by the hyperproduction of interleukin-6 (IL-6). However, case studies of MCD accompanied by hypercalcemia have rarely been reported thus far. A 78-year-old male had generalized fatigue, and his laboratory data revealed elevated serum calcium (Ca) and 1,25-dihydroxyvitamin D [1,25(OH)2D] levels (11.5 mg/dl and 80 pg/ml, respectively), while the serum intact parathyroid hormone level was low (4 pg/ml). Computed tomography showed multicentric lymphadenopathy. The serum IL-6 level was elevated (20.7 pg/ml), and pathological examination of a supraclavicular lymph node specimen led us to diagnose MCD. Moreover, immunostaining analysis showed that vitamin D-activating enzyme 25-hydroxyvitamin D 1-alpha-hydroxylase was expressed in lymph node macrophages. Prednisolone treatment improved the hypercalcemia and decreased the levels of 1,25(OH)2D and IL-6. We first reported a case of vitamin D-mediated hypercalcemia in MCD.

Specific locations of linear furrows in patients with esophageal eosinophilia.

BACKGROUND AND AIM: Linear furrows are the most frequently found endoscopic abnormality in patients with esophageal eosinophilia (EE); however, the precise endoscopic features remain to be fully elucidated. Here, we aimed to clarify the endoscopic features of EE, essential for the diagnosis of eosinophilic esophagitis (EoE), by focusing on the specific locations of linear furrows in a Japanese population. METHODS: We enrolled 70 cases with EE (≥15 eosinophils/high-power field) who were diagnosed at our hospital and related facilities. Information regarding endoscopic findings and clinical parameters was retrospectively reviewed. Next, the position of linear furrows in relation to esophageal longitudinal folds (ridge or valley) was evaluated in each case and compared with the position of mucosal breaks in patients with reflux esophagitis. Finally, the relationship between linear furrows and eosinophilic infiltration was evaluated. RESULTS: Of the 70 EE patients, 63 (90%) had linear furrows. Those occurred in a radial pattern and were widespread throughout the lower to upper esophagus, and exclusively found in esophageal longitudinal mucosal fold valleys, not on ridges, which was different from the position of mucosal breaks in patients with reflux esophagitis. Increased eosinophilic infiltration was significantly more frequent in linear furrows in the valleys (93%) as compared to mucosa on adjacent ridges (60%) (P < 0.05). CONCLUSION: Investigation of these endoscopic characteristics, especially by focusing on linear furrows in esophageal mucosal fold valleys, may provide important clues for more accurate diagnosis of EoE.

Downregulation of serotonin reuptake transporter gene expression in healing colonic mucosa in presence of remaining low-grade inflammation in ulcerative colitis.

BACKGROUND AND AIM: The serotonin reuptake transporter (SERT) terminates serotonin activity by removing it from interstitial space. Downregulated colonic SERT expression has been reported in irritable bowel disease (IBS), and symptoms resembling IBS occur in cases of inflammatory bowel disease (IBD) in remission; thus, a common pathogenesis for IBS and IBD is possible. However, little is known regarding SERT expression in colonic mucosa of IBD patients during healing. METHODS: Twenty-two ulcerative colitis (UC) patients underwent colonoscopy examinations, during which inflamed mucosa was distinguished from that undergoing healing. Healing mucosa was classified into regular and irregular vessel patterns by narrowband imaging magnifying colonoscopy. Expressions of SERT and various inflammation-related genes in biopsy samples were assessed using a polymerase chain reaction array system and real-time polymerase chain reaction. Colitis model mice were established by administration of dextran sodium sulfate or transfer of CD4(+) T cells isolated from SAMP1 mice, then time-course changes of SERT and inflammatory gene expressions were observed in colonic mucosa. RESULTS: In UC patients, SERT expression in inflamed mucosa was significantly lower than in healing mucosa. SERT expression was decreased in healing mucosa with an irregular vessel pattern with mildly increased levels of inflammatory gene expression. In mice, SERT expression was suppressed in inflamed mucosa and continuously observed with low-grade mucosal inflammation during colitis healing. CONCLUSIONS: Sserotonin reuptake transporter expression is downregulated in healing colonic mucosa of UC patients and that suppression may be dependent on the presence of remaining low-grade colonic inflammation.

[A Multivariate Analysis of the Efficacy of Adjuvant Chemotherapy in Triple-Negative Breast Cancer].

Triple-negative breast cancers(TNBCs)are associated with early recurrence after surgery and unfavorable prognoses. To date, no effective therapies for TNBCs have been established. The present study was designed to evaluate the efficacy of adjuvant chemotherapy(ACT)for 111 TNBCs using a retrospective multivariate analysis(MVA). The intravenous(iv)ACTs included docetaxel, epirubicin, gemcitabine, and vinorelbine. The oral ACTs included UFT, doxifluridine, and cyclophosphamide. The 10-year disease-free survival(DFS)and overall survival(OS)rates were 77.5% and 86.0%, respectively. Recurrences were observed in 17 patients, and the first recurrence was most frequently located in the lung. MVA revealed that pT was a significant independent variable for poor DFS and OS. UFT was the only significant independent variable for improved DFS. The survival analysis also demonstrated that UFT alone may be an effective option for Stage I TNBCs. Furthermore, it suggested that the addition of further iv ACTs to UFT could improve the outcome in patients with Stage II-III TNBCs.

Intraductal papillary mucinous carcinoma of the pancreas associated with pancreas divisum: a case report and review of the literature.

BACKGROUND: Pancreas divisum, the most common congenital anomaly of the pancreas, is caused by failure of the fusion of the ventral and dorsal pancreatic duct systems during embryological development. Although various pancreatic tumors can occur in patients with pancreas divisum, intraductal papillary mucinous neoplasm is rare. CASE PRESENTATION: A 77-year-old woman was referred to our hospital because she was incidentally found to have a cystic tumor in her pancreas at a regular health checkup. Contrast-enhanced abdominal computed tomography images demonstrated a cystic tumor in the head of the pancreas measuring 40 mm in diameter with slightly enhancing mural nodules within the cyst. Endoscopic retrograde pancreatography via the major duodenal papilla revealed a cystic tumor and a slightly dilated main pancreatic duct with an abrupt interruption at the head of the pancreas. The orifice of the major duodenal papilla was remarkably dilated and filled with an abundant extrusion of mucin, and the diagnosis based on pancreatic juice cytology was "highly suspicious for adenocarcinoma". Magnetic resonance cholangiopancreatography depicted a normal, non-dilated dorsal pancreatic duct throughout the pancreas. The patient underwent a pylorus-preserving pancreaticoduodenectomy under the diagnosis of intraductal papillary mucinous neoplasm with suspicion of malignancy arising in the ventral part of the pancreas divisum. A pancreatography via the major and minor duodenal papillae on the surgical specimen revealed that the ventral and dorsal pancreatic ducts were not connected, and the tumor originated in the ventral duct, i.e., the Wirsung's duct. Microscopically, the tumor was diagnosed as intraductal papillary mucinous carcinoma with microinvasion. In addition, marked fibrosis with acinar cell depletion was evident in the ventral pancreas, whereas no fibrotic change was noted in the dorsal pancreas. CONCLUSION: Invasive ductal carcinomas of the pancreas associated with pancreas divisum usually arise from the dorsal pancreas, in which the occurrence of pancreatic cancer may link to underlying longstanding chronic pancreatitis in the dorsal pancreas; however, the histopathogenesis of intraductal papillary mucinous neoplasm in this anomaly is a critical issue that warrants further investigation in future.

Ectopic neuroblastoma in monozygotic twins with different ages of onset: possible twin-to-twin metastasis in utero with distinct genetic alterations after birth.

We describe neuroblastoma (NB) in monozygotic twins whose ages at the onset of the disease had a 3-year interval. The primary tumor site of twin 1 was the adrenal gland, whereas that of twin 2 was the jejunum/mesentery. MYCN amplification, DNA index, ALK mutation, and copy number alterations of DNA were different between each primary tumor. NB in ectopic sites may have resulted from twin-to-twin metastasis through vascular anastamoses in the placenta. The pathogenesis of this NB involved a premalignant stage of NB during the fetal development and subsequent molecular alterations after birth, resulting in NBs that were phenotypically similar but genetically different.

Reliability of symptoms and endoscopic findings for diagnosis of esophageal eosinophilia in a Japanese population.

BACKGROUND/AIMS: The clinical characteristics of esophageal eosinophilia (EE), which is essential for diagnosis of eosinophilic esophagitis (EoE), have not been fully clarified in a Japanese population. The aim of this study was to analyze the reliability of symptoms and endoscopic findings for diagnosing EE in Japanese individuals. METHODS: We prospectively enrolled subjects who complained of esophageal symptoms suggesting EoE and/or those with endoscopic findings of suspected EoE at the outpatient clinics of 12 hospitals. Diagnostic utility was compared between the EE and non-EE groups using logistic regression analysis. RESULTS: A total of 349 patients, including 319 with symptoms and 30 with no symptoms but endoscopic findings suggesting EoE were enrolled. Of those with symptoms, 8 (2.5%) had EE, and 3 were finally diagnosed with EoE. Of those without symptoms but endoscopic findings, 4 had EE. Among 8 symptomatic patients, 7 had abnormal endoscopic findings suspicious of EoE. Although dysphagia was a major symptom in EE, none of the presenting symptoms was useful for diagnosis of EE. Among the endoscopic findings, linear furrow was the most reliable (OR = 41.583). CONCLUSION: EE is uncommon among patients with esophageal symptoms in Japanese individuals. The most useful endoscopic finding for diagnosis of EE was linear furrow, whereas subjective symptoms were not supportive.

CA19-9-producing lung metastasis after surgery for papillary thyroid carcinoma: report of a case.

Measuring tumor marker levels following cancer treatment can be useful. Although serum thyroglobulin is a useful marker after total thyroidectomy for papillary thyroid carcinoma (PTC), it is not a reliable marker for patients with a high titer of anti-thyroglobulin antibodies or when transformation to undifferentiated carcinoma has occurred. The female patient in this case report underwent total thyroidectomy and oral I-131 therapy for PTC at the age of 47 years, followed by cervical lymph node and lung resections for metastases, 3 and 11 years later, respectively. She also received oral I-131 therapy and external beam radiotherapy for mediastinal lymph node metastases. The lymphadenopathy lesions progressed and multiple lung metastases were detected when she was 61 years of age. She died at the age of 62 years. The serum CA19-9 level had gradually increased in association with enlargement of the recurrent lesions and immunostaining of CA19-9 in the pulmonary metastasis was intense. Thus, we consider that measuring the level of serum CA19-9 is an effective tool for evaluating disease status after surgery for PTC.

Generation of the novel anti-FXYD5 monoclonal antibody and its application to the diagnosis of pancreatic and lung cancer.

Despite recent advances in cancer treatments, pancreatic cancer has a dismal prognosis globally. Early detection of cancer cells and effective treatments for recalcitrant tumors are required, but the innovative therapeutic tools remain in development. Cancer-specific antigens expressed only on cancer cells may help resolve these problems, and antibodies to such antigens have potential in basic research and clinical applications. To generate specific antibodies that bind to proteins expressed on the surface of pancreatic cancer cells, we immunized mice with human pancreatic cancer MIA PaCa-2 cells, and isolated a hybridoma that produces a monoclonal antibody (mAb), named 12-13.8. This antibody was applied to molecular biological experiments such as immunocytochemistry, immunoblotting, flow cytometry, and immunoprecipitation. In addition, we showed that mAb 12-13.8 could accumulate in tumors, through in vivo experiments using cancer-bearing mice. Immunohistochemical staining of pancreatic and lung tumor tissues indicated that the increase of the staining strength by mAb 12-13.8 positively and inversely correlated with the patients' cancer recurrence and survival rate, respectively. We identified the FXYD5 protein as the target protein of mAb 12-13.8, by a human protein array screening system. The FXYD5 protein is overexpressed in various types of cancer and is modified by O-linked glycosylation. We confirmed the binding of the FXYD5 protein to mAb 12-13.8 by using FXYD5-knockout MIA PaCa-2 cells, and detailed epitope mapping identified amino acid residues 45-52 as the minimal peptide sequence. Our results indicate that mAb 12-13.8 could be a valuable tool for FXYD5 studies, and useful in diagnostic and drug delivery applications for cancer patients.

Nuclear localization signal in a cancer-related transcriptional regulator protein NAC1.

Nucleus accumbens-associated protein 1 (NAC1) might have potential oncogenic properties and participate in regulatory networks for pluripotency. Although NAC1 is described as a transcriptional regulator, the nuclear import machinery of NAC1 remains unclear. We found, using a point mutant, that dimer formation was not committed to the nuclear localization of NAC1 and, using deletion mutants, that the amino-terminal half of NAC1 harbored a potential nuclear localization signal (NLS). Wild type, but not mutants of this region, alone was sufficient to drive the importation of green fluorescent protein (GFP) into the nucleus. Bimax1, a synthetic peptide that blocks the importin α/ß pathway, impaired nuclear localization of NAC1 in cells. We also used the binding properties of importin to demonstrate that this region is an NLS. Furthermore, the transcriptional regulator function of NAC1 was dependent on its nuclear localization activity in cells. Taken together, these results show that the region with a bipartite motif constitutes a functional nuclear import sequence in NAC1 that is independent of NAC1 dimer formation. The identification of an NAC1 NLS thus clarifies the mechanism through which NAC1 translocates to the nucleus to regulate the transcription of genes involved in oncogenicity and pluripotency.

Noticeable decreased expression of tenascin-X in calcific aortic valves.

Calcification of aortic valves results in valvular aortic stenosis and is becoming a common valvular condition in elderly populations. An understanding of the molecular mechanisms of this valve lesion is important for revealing potential biomarkers associated with the development and progression of this disease. In order to identify proteins that are differentially expressed in calcific aortic valves (CAVs) compared with those in adjacent normal valvular tissues, comprehensive analysis of differentially expressed proteins in the tissues was done by a quantitative proteomic approach with isobaric tag for absolute and relative quantitation labeling followed by nanoliquid chromatography matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry. The proteomic analysis revealed 105 proteins differentially expressed in CAVs in contrast to adjacent normal valvular tissues with high confidence. Significantly increased expression (≥1.3-fold) was found in 34 proteins, whereas decreased expression (<0.77-fold) was found in 39 proteins in CAVs. Among them, α-2-HS-glycoprotein showed the greatest increase in expression (6.54-fold) and tenascin-X showed the greatest decrease in expression (0.37-fold). Numerous extracellular matrix proteins such as collagens were identified as proteins with significantly decreased expression. Panther pathway analysis showed that some of the identified proteins were linked to blood coagulation and integrin signaling pathways. Cluster analysis of the 105 proteins differentially expressed in CAVs based on the expression pattern revealed that tenascin-X was clustered with proteins controlling collagen structure and function, especially collagen fibrillogenesis, such as decorin and fibromodulin. We confirmed decreased levels of these proteins in CAVs by Western blot analyses. These results indicated that massive destruction of the extracellular matrix occurs in CAVs.

Analysis of the light-sensitivity of the photoreceptor cells of the ataxia and male sterility (AMS) mouse, an Nna1 mutant.

We confirmed retinal degeneration in the ataxia and male sterility (AMS) mouse, a mutant of the Nna1 gene, and examined the photosensitivity of the photoreceptors to determine how closely related the intrinsic and extrinsic factors were in triggering photoreceptor cell death. The AMS mice reared in a dark environment did not show atrophy of the outer nuclear layer (ONL) before 4 weeks of age, but in the older mice, retinal atrophy progressed in the same manner as in the AMS mice housed under normal light conditions. Examining the sensitivity to intentional light stimulation revealed the atrophy of the AMS retina to be exacerbated by a weak light. After administering strong light irradiation, equally severe ONL atrophy occurred in both the wild-type and AMS mice. These results indicate that in addition to functional loss of Nna1, another injurious stimulation is necessary to trigger death signals in photoreceptor cells during the postnatal period, but the cells die gradually and autonomously in older age, and that the mutation makes the cells vulnerable to a weak light, but does not increase the number of cells sensitive to strong light stimulation. Thus, these two factors are mutually independent death triggers in AMS photoreceptor cells.