Soichiro Fushimi

Leber hereditary optic neuropathy with chorea and dementia resembling Huntington disease.

Leber hereditary optic neuropathy (LHON) is a mitochondrial disease characterized by acute or subacute bilateral visual loss usually in young men. However, LHON also occurs in those with other neurologic abnormalities,1 such as epilepsy, peripheral neuropathy, tremor, dementia, dystonia, parkinsonism, and multiple sclerosis–like illness. The disease in those patients has been called “Leber plus.”2 We report a patient with Leber plus associated with chorea and dementia resembling Huntington disease (HD). A 37-year-old woman sought treatment for choreic movement and mental deterioration. She developed normally and had relatively good grades in school. At age 24 years, she showed an involuntary movement in her hands and became restless and negligent of housekeeping. At approximately age 30 years, her choreic movement spread to the upper extremities and trunk. By age 34 years, she was unable to walk or do most housekeeping tasks. She also …

Cyclin D2 is overexpressed in proliferation centers of chronic lymphocytic leukemia/small lymphocytic lymphoma

The D cyclins are important cell cycle regulatory proteins involved in the pathogenesis of some lymphomas. Cyclin D1 overexpression is a hallmark of mantle cell lymphoma, whereas cyclins D2 and D3 have not been shown to be closely associated with any particular subtype of lymphoma. In the present study, we found that cyclin D2 was specifically overexpressed in the proliferation centers (PC) of all cases of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) examined (19/19). To examine the molecular mechanisms underlying this overexpression, we immunohistochemically examined the expression of nuclear factor (NF)‐κB, p15, p16, p18, and p27 in the PC of six patients. Five cases showed upregulation of NF‐κB expression, which is known to directly induce cyclin D2 by binding to the promoter region of CCND2. All six PC examined demonstrated downregulation of p27 expression. In contrast, upregulation of p15 expression was detected in five of six PC examined. This discrepancy suggests that unknown cell cycle regulatory mechanisms involving NF‐κB‐related pathways are also involved, because NF‐κB upregulates cyclin D2 not only directly, but also indirectly through c‐Myc, which is believed to downregulate both p27 and p15. In conclusion, cyclin D2 is overexpressed in the PC of CLL/SLL and this overexpression is due, in part, to the upregulation of NF‐κB‐related pathways. (Cancer Sci 2011; 102: 2103–2107)

Spred-2 Deficiency Exacerbates Lipopolysaccharide-Induced Acute Lung Inflammation in Mice

Background Acute respiratory distress syndrome (ARDS) is a severe and life-threatening acute lung injury (ALI) that is caused by noxious stimuli and pathogens. ALI is characterized by marked acute inflammation with elevated alveolar cytokine levels. Mitogen-activated protein kinase (MAPK) pathways are involved in cytokine production, but the mechanisms that regulate these pathways remain poorly characterized. Here, we focused on the role of Sprouty-related EVH1-domain-containing protein (Spred)-2, a negative regulator of the Ras-Raf-extracellular signal-regulated kinase (ERK)-MAPK pathway, in lipopolysaccharide (LPS)-induced acute lung inflammation. Methods Wild-type (WT) mice and Spred-2−/− mice were exposed to intratracheal LPS (50 µg in 50 µL PBS) to induce pulmonary inflammation. After LPS-injection, the lungs were harvested to assess leukocyte infiltration, cytokine and chemokine production, ERK-MAPK activation and immunopathology. For ex vivo experiments, alveolar macrophages were harvested from untreated WT and Spred-2−/− mice and stimulated with LPS. In in vitro experiments, specific knock down of Spred-2 by siRNA or overexpression of Spred-2 by transfection with a plasmid encoding the Spred-2 sense sequence was introduced into murine RAW264.7 macrophage cells or MLE-12 lung epithelial cells. Results LPS-induced acute lung inflammation was significantly exacerbated in Spred-2−/− mice compared with WT mice, as indicated by the numbers of infiltrating leukocytes, levels of alveolar TNF-α, CXCL2 and CCL2 in a later phase, and lung pathology. U0126, a selective MEK/ERK inhibitor, reduced the augmented LPS-induced inflammation in Spred-2−/− mice. Specific knock down of Spred-2 augmented LPS-induced cytokine and chemokine responses in RAW264.7 cells and MLE-12 cells, whereas Spred-2 overexpression decreased this response in RAW264.7 cells. Conclusions The ERK-MAPK pathway is involved in LPS-induced acute lung inflammation. Spred-2 controls the development of LPS-induced lung inflammation by negatively regulating the ERK-MAPK pathway. Thus, Spred-2 may represent a therapeutic target for the treatment of ALI.

Disappearance of an activated EGFR mutation after treatment with EGFR tyrosine kinase inhibitors

A 34-year-old Japanese woman presented with left supraclavicular lymph node swelling. Computed tomography scans revealed a mass on the left lower lobe, pulmonary nodules, and pleural effusion. A lymph node biopsy revealed large-cell carcinoma with an epidermal growth factor receptor (EGFR) deletion mutation, L747-T751 in exon 19. Although malignant pleural effusions carried the same EGFR mutation, progressive pleural effusions after treatment with chemotherapy, gefitinib, and erlotinib did not show any EGFR mutation. A cell line established from the pleural effusion 3 days before the patient expired also did not harbor the EGFR mutation. Histological sections of the lymph node of the patient were similar to those of the xenograft tumor of the cell line. There may be genetic heterogeneity in EGFR mutant tumors.

Bovine lactoferrin ameliorates ferric nitrilotriacetate-induced renal oxidative damage in rats

Milk provides a well-balanced source of amino acids and other ingredients. One of the functional ingredients in milk is lactoferrin (LF). LF presents a wide variety of bioactivities and functions as a radical scavenger in models using iron-ascorbate complexes and asbestos. Human clinical trials of oral LF administration for the prevention of colon polyps have been successful and demonstrated that dietary compounds exhibit direct interactions. However, antioxidative properties of LF in distant organs require further investigation. To study the antioxidant property of LF, we employed bovine lactoferrin (bLF) using the rat model of ferric nitrilotriacetate (Fe-NTA)-induced renal tubular oxidative injury. We fed rats with bLF (0.05%, w/w) in basal chow for 4 weeks and sacrificed them after Fe-NTA treatment. After intraperitoneal administration of 9.0 mg iron/kg Fe-NTA for 4 and 24 h, bLF pretreatment suppressed elevation of serum creatinine and blood urea nitrogen levels. In addition, we observed protective effects against renal oxidative tubular damage and maintenance of antioxidant enzyme activities in the bLF-pretreated group. We thus demonstrated the antioxidative effect of bLF against Fe-NTA-induced renal oxidative injury. These results suggest that LF intake is useful for the prevention of renal tubular oxidative damage mediated by iron.

Forced expression of suppressor of cytokine signaling 3 in T cells protects the development of concanavalin A-induced hepatitis in mice

T cells play central roles in liver diseases, but the regulatory mechanism by cytokine signaling is not well understood. In the present study, we explored the role of SOCS3 in T cells in concanavalin A (ConA)-induced hepatitis. Mice with T-cell-specific overexpression of SOCS3 (SOCS3-cTg) showed reduced hepatic damage and improved mice survival relative to the control, an event that was associated with decreased apoptotic signals Fas and pStat1. Expression of Th1-cytokines/chemokines was decreased in SOCS3-cTg liver with reduced expression of T-bet, a Th1-transcription factor. Flow cytometric analysis of the liver lymphocytes demonstrated that activated CD4(+) T cells, cytotoxic T cells and natural killer T cells were significantly decreased in SOCS3-cTg liver with decreased expression of perforin and granzyme B, injurious molecules for hepatocyte damage. These results suggest that forced expression of SOCS3 in T cells prevents ConA-induced liver injury by inhibiting several phases of Th1 responses.

Spred-2 deficiency exacerbates acetaminophen-induced hepatotoxicity in mice.

MAPKs are involved in acetaminophen (APAP)-hepatotoxicity, but the regulatory mechanism remains unknown. Here, we explored the role of Spred-2 that negatively regulates Ras/ERK pathway in APAP-hepatotoxicity. Spred-2 knockout (KO) mice demonstrated exacerbated liver injury, an event that was associated with increased numbers of CD4(+) T, CD8(+) T and NK cells in the liver compared to the control. Levels of CXCL9/CXCL10 that attract and activate these cells were increased in Spred-2 KO-liver. Kupffer cells isolated from Spred-2 KO mice after APAP challenge expressed higher levels of CXCL9/CXCL10 than those from the control. Upon stimulation with APAP or IFNγ, naïve Kupffer cells from Spred-2 KO mice expressed higher levels of CXCL9/CXCL10. NK cell-depletion attenuated APAP-hepatotoxicity with lowered hepatic IFNγ and decreased numbers of not only NK cells but also CD4(+) T and CD8(+) T cells in the liver. These results suggest that Spred-2 negatively regulates APAP-hepatotoxicity under the control of Kupffer cells and NK cells.

Effects of pharyngeal cooling on brain temperature in primates and humans: a study for proof of principle.

Background: Pharyngeal cooling decreases brain temperature by cooling carotid arteries. This study was designed to evaluate the principle of pharyngeal cooling in monkeys and humans. Methods: Monkeys (n = 10) were resuscitated following 12 min of cardiac arrest. Pharyngeal cooling (n = 5), in which cold saline (5°C) was perfused into the cuff at the rate of 500 ml/min, was initiated simultaneously with the onset of resuscitation for 30 min. Patients (n = 3) who were in an intensive care unit were subjected to 30 min of pharyngeal cooling under propofol anesthesia. Results: In the animal study, core brain temperature was significantly decreased compared with that in the control group by 1.9°C (SD = 0.8, P < 0.001) and 3.1°C (SD = 1.0, P < 0.001) at 10 min and 30 min after the onset of cooling, respectively. The cooling effect was more evident in an animal with low postresuscitation blood pressure. Total dose of epinephrine, number of direct current shocks, and recovery of blood pressure were not different between the two groups. The pharyngeal epithelium was microscopically intact on day 5. In the clinical study, insertion of the cuff and start of perfusion did not affect heart rate or blood pressure. Tympanic temperature was decreased by 0.6 ± 0.1°C/30 min without affecting bladder temperature. The pharynx was macroscopically intact for 3 days. Conclusions: Pharyngeal cooling rapidly and selectively decreased brain temperature in primates and tympanic temperature in humans and did not have adverse effects on return of spontaneous circulation, even when initiated during cardiac arrest in primates.

A Novel Role of Spred2 in the Colonic Epithelial Cell Homeostasis and Inflammation

Rapid and adequate mucosal healing is important for a remission of ulcerative colitis (UC) patients. Here, we examined whether Spred2, a member of the Sprouty-related EVH1-domain-containing proteins that inhibit the Ras/Raf/ERK pathway, plays a role in colonic mucosal homeostasis and inflammation by using Spred2 knockout (KO) mice. We first detected increased epithelial cell proliferation and cadherin 1 expression in the colon of naïve Spred2 KO mice compared to wild-type mice. Interestingly, Spred2 KO mice were resistant to dextran sulfate sodium (DSS)-induced acute colitis as indicated by lower levels of body weight loss and disease activity index. Histologically, epithelial cell injury and inflammation were milder in the colonic mucosa of Spred2 KO mice on day 3 and almost undetectable by day 8. Experiments with bone chimeric mice indicated that Spred2-deficiency in non-hematopoietic cells was responsible for the reduced sensitivity to DSS. Finally, Spred2 KO mice developed significantly fewer tumors in response to azoxymethane plus DSS. Taken together, our results demonstrate, for the first time, that Spred2 plays an important role in the regulation of colonic epithelial cell proliferation and inflammation by potentially down-regulating the activation of ERK. Thus, Spred2 may be a new therapeutic target for the treatment of UC.

Pancreatic Hepatoid Carcinoma Mimicking a Solid Pseudopapillary Neoplasm: A Challenging Case on Endoscopic Ultrasound-guided Fine-needle Aspiration.

A 59-year-old man was admitted to our hospital for treatment of a 45 mm pancreatic mass found during a medical examination. Endoscopic ultrasound-guided fine-needle aspiration cytology showed polygonal cells with pseudopapillary structures. The tumor cells were positive for nuclear/cytoplasmic β-catenin and CD10, and negative for chromogranin A. After a tentative diagnosis of a solid pseudopapillary neoplasm, middle pancreatectomy was performed. Histologically, polygonal cells with abundant eosinophilic cytoplasm formed in the trabeculae and were immunohistochemically positive for HepPar1 and protein induced by vitamin K absence or antagonist-II. The tumor was finally diagnosed to be pancreatic hepatoid carcinoma. No recurrence occurred for 12 months, even without adjuvant chemotherapy.