PURPOSE: The purpose of this study was to examine the molecular basis for steroid-induced cataract and the specific aim was to investigate the potential effects of glucocorticoids on modulation of alpha-crystallin gene expression in lens epithelial cells. METHOD: Bovine lens epithelial explants, B-3 human lens epithelial cells, and alphaTN4 mouse lens epithelial cells were incubated in the absence or presence of dexamethasone. At the indicated time point, total cellular RNA was isolated and subjected to RT-PCR and Northern blot analysis to assess mRNA expression of alphaA- and alphaB-crystallin. RESULTS: The mRNA expression of alphaA-crystallin was drastically downregulated by treatment with dexamethasone in bovine, human, and mouse lens epithelial cells. The mRNA level of alphaA-crystallin was also decreased in response to hydrocortisone but not to estrogen. The stability of the alphaA-crystallin mRNA was decreased after dexamethasone treatment. CONCLUSIONS: These results suggest that the alteration of alphaA-crystallin gene expression by glucocorticoids may result in abnomal structure and differentiation of lens epithelial cells on steroid-induced cataract formation.
alpha-Crystallins* ; Animals ; Blotting, Northern ; Cataract ; Dexamethasone ; Epithelial Cells* ; Estrogens ; Gene Expression* ; Glucocorticoids* ; Humans ; Hydrocortisone ; Mice ; RNA ; RNA, Messenger

The aim of this study was to evaluate prognostic and/or diagnostic factors of canine mammary tumors by immunohistochemically analyzing the expression of alpha basic crystallin (alphaB-c). For this, formalin-fixed, paraffin-embedded blocks of 51 naturally-occurring canine mammary tumors (11 benign and 40 malignant) were used. Tissue from eight normal canine mammary glands were served as a control. Immunohistochemically, in the control mammary tissues, a few luminal epithelial cells were alphaB-c positive but myoepithelial cells were negative. In benign or simple type malignant tumors, alphaB-c expression was observed in luminal epithelial cells while the myoepithelial basal cells were negative. In benign or complex type malign tumors, positive staining was predominantly found in the cytoplasm of epithelial cells. Immunoreactivity of alphaB-c was also observed in neoplastic myoepithelial cells. Statistically, the number of cells immunolabeled with alphaB-c was found to be significantly different among tissues from normal canine mammary glands, benign lesions, and malignant tumors (p < 0.05). alphaB-c immunoreactivity was higher in malignant tumors than the control mammary tissues (p < 0.001). Data obtained in the current study revealed a strong association between high expression levels of alphaB-c and primary mammary gland tumors in canines.
Animals ; Dog Diseases/*metabolism ; Dogs ; Female ; Immunohistochemistry/veterinary ; Logistic Models ; Mammary Neoplasms, Animal/*metabolism ; alpha-Crystallins/*biosynthesis

To screen molecular chaperones similar to small heat shock proteins (sHsps), but without alpha-crystalline domain, heat-stable proteins from Schizosaccharomyces pombe were analyzed by 2-dimensional electrophoresis and matrix assisted laser desorption/ionization time-of-flight mass spectrometry. Sixteen proteins were identified, and four recombinant proteins, including cofilin, NTF2, pyridoxin biosynthesis protein (Snz1) and Wos2 that has an alpha-crystalline domain, were purified. Among these proteins, only Snz1 showed the anti-aggregation activity against thermal denaturation of citrate synthase. However, pre-heating of NTF2 and Wos2 at 70degrees C for 30 min, efficiently prevented thermal aggregation of citrate synthase. These results indicate that Snz1 and NTF2 possess molecular chaperone activity similar to sHsps, even though there is no alpha-crystalline domain in their sequences.
alpha-Crystallins ; Citrate (si)-Synthase ; Electrophoresis ; Heat-Shock Proteins, Small* ; Mass Screening* ; Mass Spectrometry ; Molecular Chaperones* ; Pyridoxine ; Recombinant Proteins ; Schizosaccharomyces*

alphaB-crystallin is the structural protein of vertebrate lens, which is widely expressed in non-lens tissue. As one of the heat shock protein family members, alphaB-crystallin possesses biological properties of molecular chaperones and anti-apoptotic effects. Multi-factor injuries, such as retinopathy, inflammation and nervous system diseases, have a closely relationship with alphaB-crystallin. This paper reviews the research progress of the expression and mechanism of alphaB-crystallin in retina and extraocular tissues and organs.
Crystallins ; Gene Expression Regulation, Developmental ; Heat-Shock Proteins/metabolism* ; Humans ; Lens, Crystalline ; Retina ; alpha-Crystallin B Chain/metabolism*

Distal hereditary motor neuropathy (dHMN) is a heterogeneous disorder characterized by degeneration of motor nerves in the absence of sensory abnormalities. Recently, mutations in the small heat shock protein 27 (HSP27) gene were found to cause dHMN type II or Charcot-Marie-Tooth disease type 2F (CMT2F). The authors studied 151 Korean axonal CMT or dHMN families, and found a large Korean dHMN type II family with the Ser135Phe mutation in HSP27. This mutation was inherited in an autosomal dominant manner, and was well associated with familial members with the dHMN phenotype. This mutation site is located in the ?-crystallin domain and is highly conserved between different species. The frequency of this HSP27 mutation in Koreans was 0.6%. Magnetic resonance imaging analysis revealed that fatty infiltrations tended to progressively extend distal to proximal muscles in lower extremities. In addition, fatty infiltrations in thigh muscles progressed to affect posterior and anterior compartments but to lesser extents in medial compartment, which differs from CMT1A patients presenting with severe involvements of posterior and medial compartments but less involvement of anterior compartment. The authors describe the clinical and neuroimaging findings of the first Korean dHMN patients with the HSP27 Ser135Phe mutation. To our knowledge, this is the first report of the neuroimaging findings of dHMN type II.
Adolescent ; Adult ; Age of Onset ; Animals ; Asian Continental Ancestry Group ; Charcot-Marie-Tooth Disease/*genetics/physiopathology/radionuclide imaging ; Child ; Child, Preschool ; Female ; *Genetic Predisposition to Disease ; Humans ; Intracellular Signaling Peptides and Proteins/*genetics ; Korea ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Muscular Atrophy/physiopathology/radionuclide imaging ; *Mutation, Missense ; Neural Conduction/genetics ; Pedigree ; Protein-Serine-Threonine Kinases/*genetics ; alpha-Crystallins/genetics