Phase separation of α-crystallin-GFP protein and its implication in cataract disease.

Cataract, the leading cause of blindness worldwide, is caused by crystallin protein aggregation within the protected lens environment. Phase separation has been implicated as an important mechanism of protein aggregation diseases, such as neurodegeneration. Similarly, cataract has been proposed to be a protein condensation disease in the last century. However, whether crystallin proteins aggregate via a phase separation mechanism and which crystallin protein initiates the aggregation remain unclear. Here, we showed that all types of crystallin-GFP proteins remain soluble under physiological conditions, including protein concentrations, ion strength, and crowding environments. However, in age or disease-induced aberrant conditions, α-crystallin-GFP, including αA- and αB-crystallin-GFP, but not other crystallin-GFP proteins, undergo phase separation in vivo and in vitro. We found that aging-related changes, including higher crystallin concentrations, increased Na+, and decreased K+ concentrations, induced the aggregation of α-crystallin-GFP. Furthermore, H2O2, glucose, and sorbitol, the well-known risk factors for cataract, significantly enhanced the aggregation of αB-crystallin-GFP. Taken together, our results revealed that α-crystallin-GFP forms aggregates via a phase transition process, which may play roles in cataract disease. Opposite to the previously reported function of enhancing the solubility of other crystallin, α-crystallin may be the major aggregated crystallin in the lens of cataract patients.

Clinicopathologic and Immunophenotypic Features of Primary Intestinal Extranodal NK/T-Cell Lymphoma, Nasal Type.

Primary intestinal extranodal NK/T-cell lymphoma, nasal type, is an extremely rare type of lymphoma with poor prognosis, and early diagnosis is challenging. Here we have investigated the clinicopathologic features and immunophenotypes of primary intestinal extranodal NK/T cell lymphomas, nasal type, in 10 Chinese patients. Complete staging data showed that 1 patient had stage I disease, 7 had stage II disease, and 2 had stage III disease. Eight of 10 (80%) patients had lymphadenopathy and none had bone marrow involvement. All the patients had a low International Prognostic Index (IPI) score (<3) at presentation. The median age at the time of diagnosis was 37.5 years (range = 24-68 years). All the patients died within 21 months, and the median survival time was 9.5 months (range = 2-21 months). So the conventional IPI and staging system failed to predict the outcome of the patients with the lymphoma. Except for the size of tumor cells, most of the morphologic features of the cases we studied were similar to those involving the midline facial tissue. Immunohistochemical studies showed the expression of cytotoxic markers (100%), CD2 (100%), CD3ε (90%), CD56 (80%), P53 (60%), CD30 (30%), LMP1 (30%), EBNA3A (0%). Nine cases (90%) highly expressed Ki-67. In situ hybridization for Epstein-Barr virus-encoded small RNA was positive in all cases.

Primary extranodal NK/T cell lymphoma, nasal-type of uterus with adenomyosis: a case report.

Natural killer (NK)/T cell lymphoma of the female genital tract is extremely rare. We here report a case of 'nasal type' NK/T cell lymphoma arising in the uterus with adenomyosis in a 41-year-old woman with fever and hypogastralgia. The histologic analysis demonstrated a highly aggressive tumor with characteristic angiocentric/angiodestructive growth pattern and focal necrosis. The lymphoma cells displayed a CD3ϵ/CD56/TIA-1/granzyme-B/Perforin-positive and CD20/CD79a/CD4/CD8-negative immunophenotype and positive for Epstein-Barr virus by EBER in situ hybridization. Clinically, the disease was limited to the uterus at the initial diagnosis, but progressed rapidly. The patient died on day 54 after hysterectomy, irrespective of intensive chemotherapy. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1323474831125945.

[Identification of rabbit lens proteins by two-dimensional gel electrophoreses and mass spectrometry].

OBJECTIVE: To study the role of lens proteomics using two-dimensional electrophoresis (2-DE) and mass spectrometry in order to exploring novel effective ways for cataract prevention and therapy. METHODS: The proteins of the three-month-year old rabbit lens were separated using immobilized pH gradients 2-DE. Image analysis was carried out using Image Master 2D Elite 3.01 software package. Most of the crystallines was identified by matrix assisted laser adsorption/ionization-time of-flight-mass spectrometry (MALDI-TOF-MS). RESULTS: The maps of 2-DE showed that lens proteins were in the section of pH 5 - 9 and the relative molecular weight was 14,000 - 94,000, while relative molecular weight of more abundant crystalline was localized at 14,000 - 40,000. About 180 protein spots were detected with the similar PI, molecular weight and quantity of each spot could be acquired by image analysis software. Sixteen crystallines were identified using MALDI-TOF-MS. CONCLUSION: Proteomic analysis of lens can be accomplished and the proteins can be well separated and analyzed using 2-DE and mass spectrometry. This technique offers a new avenue for analyses of lens proteins and to assess their differential expression in cataract, and may thus provide a novel approach to cataract prevention and therapy.

[Expression of Pax-6 homeobox gene in lens epithelial cells in vitro].

OBJECTIVE: To detect the gene expression of Pax-6 in cultured lens epithelial cells (LECs) of mouse in vitro in order to study the gene factor that maintains the LECs characteristics. METHODS: Cultured the LECs (passage 1 to 3) were used in the study, the expression of Pax-6 gene in LECs was demonstrated by reverse transcriptase polymerase chain reaction (RT-PCR), immunohistochemical staining and Western blot. RESULTS: The mRNA of Pax-6 gene was positive in primary culture, the first and second passage of LECs using RT-PCR. The protein of Pax-6 gene was also positive in Western blot and immunohistochemical staining, but it was weak positive in the third passage of LECs and none in all passages of negative control groups. CONCLUSION: The LECs are positive for the gene of Pax-6. The normal expression of Pax-6 gene is vital for maintaining the LECs characteristics.