We describe here the development of potent synthetic analogues of the naturally occurring triterpenoid lanosterol to reverse protein aggregation in cataracts. Lanosterol showed superiority to other scaffolds in terms of efficacy and generality in previous studies. Various modified lanosterol derivatives were synthesized via modification of the side chain, ring A, ring B, and ring C. Evaluation of these synthetic analogues draws a clear picture for SAR. In particular, hydroxylation of the 25-position in the side chain profoundly improved the potency, and 2-fluorination further enhanced the biological activity. This work also revealed that synthetic lanosterol analogues could reverse multiple types of mutant-crystallin aggregates in cell models with excellent potency and efficacy. Notably, lanosterol analogues have no cytotoxicity but can improve the viability of the HLE-B3 cell line. Furthermore, representative compound 6 successfully redissolved the aggregated crystallin proteins from the amyloid-like fibrils in a concentration-dependent manner.

OBJECTIVE: αB -crystallin (αBC) belongs to the family of small heat shock proteins that are necessary for maintaining oxygen homeostasis. This study was designed to explore the possible effects of αBC on N-methyl- N-nitrosourea (MNU) induced retinal degeneration and the underlying mechanisms.
METHODS: The αBC was injected into the vitreous bodies of MNU administered mice. The retinal morphology and visual function of experimental animals were analyzed by electroretinography (ERG), Spectral domain optical coherence tomography (SD-OCT), fundus photographs, optokinetic testing and immunohistochemistry assay.
RESULTS: Optokinetic behavioural tests and ERG examination suggested that the visual impairments of the MNU administered mice were ameliorated effectively by αBC treatment. OCT analysis showed that the major retinal architecture of the MNU administered mice was efficiently rescued by αBC treatment. Fundus examination suggested that the lesion size of the MNU administered mice was decreased by αBC treatment. MNU induced photoreceptor loss was also mitigated by αBC treatment as shown by hematoxylin and eosin staining. In particular, the immunostaining study suggested that M-cone photoreceptors, rather than the S-cone photoreceptors, were preferentially rescued, indicating that the photoreceptor populations have different sensitivities to αBC. The mechanism study suggested that the anti-apoptotic, anti-oxidative and neurotrophic function of αBC collectively contributed to these therapeutic effects.
CONCLUSIONS: Intravitreal delivery of αBC could alleviate MNU induced photoreceptor degeneration and visual impairment. Further refinement of the αBC induced protection would afford a novel therapeutic strategy for retinitis pigmentosa.

The eye lens contains a highly concentrated, polydisperse mixture of crystallins, and a loss in transparency during cataract formation is attributed to the aggregation of these proteins. Most biochemical and biophysical studies of crystallins have been performed in diluted samples because of various physical limitations of the respective method at physiological concentrations of up to 200-400 mg/mL. We introduce a straightforward proton NMR transverse relaxometry method to quantify simultaneously proteins in the dissolved and aggregated states at these elevated concentrations, because these states significantly differ in their transverse relaxation properties. The key feature of this method is a direct observation of the protein signal in a wide range of relaxation delays, from few microseconds up to few hundred milliseconds. We applied this method to follow heat-induced aggregation of bovine α- and γB-crystallin between 60 and 200 mg/mL. We find that at 60 °C, a temperature where both crystallins still comprise a native tertiary structure, γB-crystallin aggregated at these high protein concentrations with a time constant of about 30-40 h. α-crystallin remained soluble at 60 mg/mL but formed a transparent gel at 200 mg/mL. This quantitative NMR method can be applied to investigations of other proteins and their mixtures under various aggregation conditions.

Curcumin (Cur) exhibits anticataractogenesis activity. This study aimed to compare the activities of Cur with those of its degradation products in a series of in vitro lens protein turbidity assays. The results show that Cur (200 μM) ameliorates selenite-induced crystallin aggregation, and the mean OD value was 0.10 ± 0.02 (p < 0.05), which was significantly different from controls (0.15 ± 0.01) after incubating for 3 days. However, Cur did not significantly inhibit calcium-induced proteolysis after incubating for 3 days. Such results were supported by isothermal titration calorimetry observation that Cur binds with selenite but not with calcium. Presence of Cur and the degradation products examined (ferulic acid, cinnamic acid, vanillin, and vanillic acid) indicates significantly protective activities on lens γ-crystallins after UVC exposure for 3 h. Among the compounds examined, only ferulic acid exhibited a significant inhibitory effect against UVB-induced turbidity with a mean OD of 0.32 ± 0.01 (p < 0.05), which was significantly different from controls (0.49 ± 0.02). The previously reported anticataract effects of Cur may stem not only from Cur but also from its degradation products through various cataractogenesis mechanisms in vitro.

A combination of Raman spectroscopy, imaging, hierarchical cluster analysis (HCA) and peak ratio analysis was used to analyze protein profiles in the superficial cortex (SC), deep cortex (DC) and nucleus of old human lenses with cortical, nuclear and mixed cataracts. No consistent differences were observed in protein spectra and after cluster analysis between the three locations irrespective of the presence or absence of cortical opacities and/or coloration. A sharp increase (∼15%-∼33%) in protein content from SC to DC, normal for human lenses, was found in 7 lenses. In 4 lenses, characterized by the absence of cortical opacities, the SC has a protein content of ∼35%. A significant increase in the disulfide-to-protein ratio is found only in the SC of the 7 cortical cataracts. No changes were found in sulfhydryl-to-protein ratio. The relative contents of α-helices and β-sheets increase from SC to nucleus. β-Sheets are more common in the SC of lenses with cortical cataract. The absence of significant and consistent changes in protein profiles between nucleus and cortex even in cases of severe coloration is not favoring the prevailing concept that ubiquitous protein oxidation is a key factor for age related nuclear (ARN) cataracts. The observations favor the idea that multilamellar bodies or protein aggregates at very low volume densities are responsible for the rise in Mie light scatter as a main cause of ARN cataracts leaving the short-range-order of the fiber cytoplasm largely intact. The absence of significant changes in the protein spectra of the deep cortical opacities, milky white as a result of the presence of vesicle-like features, indicate they are packed with relatively undisturbed crystallins.

Cataracts is a misfolding protein disease in which one of the major components is the γD-crystallin protein. The conformational structure of the aggregated γD-crystallin and the interactions that cause aggregation are largely unknown. A recent experimental two-dimensional infrared (2DIR) spectroscopy study determined that the C-terminal domain has a high propensity to form β-sheets whereas the N-terminal domain forms a disordered structure in the fiber state. We present a combined computational molecular dynamics and infrared spectroscopy study of the local dynamics of these domains. The computed 2DIR signals agree remarkably well with experiment. We show that the two domains, both of which have a Greek key structural fold, experience different electrostatic environments, which may be related to the fact that the C-terminal domain is more structurally stable than the N-terminal domain. We correlate the vibrational couplings to known energy dissipation mechanisms and reveal their origin.

OBJECTIVE: To investigate the expression of αB-crystallin and its possible role of anti-apoptosis in oral verrucous carcinoma.
METHODS: The expression of αB-crystallin and activated caspase-3 was detected in oral verrucous carcinoma, oral squamous carcinoma and normal mucosa by immunohistochemistry, and their relationship was investigated. SPSS 16.0 software package was used for statistical analysis. Nonparametric test and spearman correlation test were performed.
RESULTS: The expression of αB-crystallin in oral verrucous carcinoma and oral squamous carcinoma was significantly higher than that in normal mucosa(P<0.05). And in oral verrucous carcinoma, the increase of expression of αB-crystallin coincided with the decrease of expression of activated caspase-3(P<0.05).
CONCLUSIONS: αB-crystallin may play a role of anti-apoptosis by inhibiting the activation of caspase-3 in oral verrucous carcinoma.

Using differential electrophoresis protein composition of lens major proteins in hybrid mice F1 (C57B1XCBA) with cataracts of different etiology (senile, ultraviolet, radioactive and combined ultraviolet-radioactive exposure) was studied Changes that may be specific for cataract caused by aging, ultraviolet and/or gamma-irradiation were not revealed in water-soluble and water-insoluble protein fractions.

BACKGROUND: Necrotizing infundibular crystalline folliculitis (NICF) is a folliculocentric disorder associated with filamentous crystalline deposits, enclosed by parakeratotic columns within the partly necrotic follicular ostium and infundibulum. There are only very few data published about this disorder of unknown origin.
OBJECTIVE: We sought to determine the clinicopathological features and pathogenetic aspects of NICF.
METHODS: Clinicopathological characterization of 9 patients with NICF and a second group of 7 patients with coincidental findings of NICF in the vicinity of epithelial skin neoplasms was conducted.
RESULTS: Clinically, NICF is characterized by multiple waxy papules with predilection for the forehead (56%), neck, and back. Birefringent crystalline deposits were present in the follicular ostia and enclosed by parakeratotic columns in all cases. The necrosis of follicular epithelium was found in 89% and perifollicular neutrophilic infiltrate in 22% of the biopsy specimens. Both yeasts and gram-positive bacteria were identified within the affected follicles in 56% in the first group and 86% in the second group of coincidental NICF.
CONCLUSIONS: This was a single-center retrospective study.
CONCLUSIONS: NICF is both a distinct entity and an epiphenomenon in the context of other disorders. In regard to the common association with yeasts and gram-positive bacteria in the affected follicles, we hypothesize that NICF is pathogenetically linked to these organisms, which is supported by resolution of the lesions after topical or systemic antimycotic treatment.

OBJECTIVE: To identify the gene mutation in a four-generation Chinese family with autosomal dominant congenital cataract associated with microcornea.
METHODS: Experimental research. Twelve members in this family (including six affected and six unaffected individuals) were enrolled into this study. They underwent full ophthalmological and clinical examinations to rule out any concomitant disorders. Blood samples were collected and genomic DNA was extracted. Microsatellite markers near the reported loci, which are associated with congenital cataract and microcornea were selected and amplified from DNA samples using polymerase chain reaction. Linkage analysis was performed. The exons and exon/intron junction of candidate gene in the related chromosome were sequenced. The product of the first exon was digested by ApaL I restriction enzyme to certify the mutation.
RESULTS: The phenotype studied in this family was nuclear cataract accompanied with microcornea. At markers D21S1885 and D21S1890 near the locus 21q22.3, the affected members had the same allele, but the unaffected did not. The Lod scores were 2.11 in both markers, indicating that this locus were linked to the congenital cataract in this family. DNA sequencing of candidate gene CRYAA showed a heterozygous mutation c.34C > T in exon 1, which led to condon 12 in peptide chain encoding arginine substituted by cysteine. ApaL I enzyme digestion certified that all of the affected members had the same mutation c.34C > T, but the unaffected and normal individuals did not.
CONCLUSIONS: Mutation (p.R12C) of CRYAA is the genetic change that causes the occurrence of congenital cataract with microcornea in this family.