Impact of α-crystallin protein loss on zebrafish lens development

Posner, Mason; Murray, Kelly L.; Andrew, Brandon; Brdicka, Stuart; Roberts, Alexis; Franklin, Kirstan; Hussen, Adil; Kaye, Taylor; Kepp, Emmaline; McDonald, Mathew S; Snodgrass, T. L.; Zientek, Keith; David, Larry L.

doi:10.1016/j.exer.2022.109358

Cited by 9 publications

(8 citation statements)

References 58 publications

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Section: Discussioncontrasting

confidence: 88%

“…While we did not find increased levels of age-related cataracts in fishes lacking αA-crystallin, larvae lacking this protein did show visible lens defects at 3 and 4 dpf (Zou et al, 2015; Posner et al, 2022). Those defects manifested as central roughness, disorganization of central fiber cells, and irregular borders between fiber cells (Posner et al, 2022). The lack of increased cataract in adult cryaa null fish suggests that these early developmental defects are either transient, or do not alter transparency as the lens grows.…”

Section: Discussioncontrasting

confidence: 88%

“…Mutations of each of the three αB-crystallin genes have been used to examine their impact on early lens development. Zebrafish mutants that do not express αA-crystallin show subtle defects, such as roughness and irregular borders between fiber cells, that were observable using differential interference contrast microscopy (Zou et al, 2015; Posner et al, 2022). Results with αB-crystallin mutants were mixed, with one study showing lens developmental defects while another showed no effect (Mishra et al, 2018; Posner et al, 2022).…”

Section: Introductionmentioning

confidence: 99%

“…Zebrafish mutants that do not express αA-crystallin show subtle defects, such as roughness and irregular borders between fiber cells, that were observable using differential interference contrast microscopy (Zou et al, 2015; Posner et al, 2022). Results with αB-crystallin mutants were mixed, with one study showing lens developmental defects while another showed no effect (Mishra et al, 2018; Posner et al, 2022). It is not known how the loss of α-crystallins might affect cataract development as fish age.…”

Section: Introductionmentioning

confidence: 99%

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Loss of αBa-crystallin, but not αA-crystallin, increases age-related cataract in the zebrafish lens

Posner,

Garver,

Kaye

et al. 2024

Preprint

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The vertebrate eye lens is an unusual organ in that most of its cells lack nuclei and the ability to replace aging protein. The small heat shock protein α-crystallins evolved to become key components of this lens, possibly because of their ability to prevent aggregation of aging protein that would otherwise lead to lens opacity. Most vertebrates express two α-crystallins, αA- and αB-crystallin, and mutations in each are linked to human cataract. In a mouse knockout model only the loss of αA-crystallin led to early-stage lens cataract. We have used the zebrafish as a model system to investigate the role of α-crystallins during lens development. Interestingly, while zebrafish express one lens-specific αA-crystallin gene (cryaa), they express two αB-crystallin genes, with one evolving lens specificity (cryaba) and the other retaining the broad expression of its mammalian ortholog (cryabb). In this study we used individual mutant zebrafish lines for all three α-crystallin genes to determine the impact of their loss on age-related cataract. Surprisingly, unlike mouse knockout models, we found that the loss of the αBa-crystallin genecryabaled to an increase in lens opacity compared tocryaanull fish at 24 months of age. Loss of αA-crystallin did not increase the prevalence of cataract. We also used single cell RNA-Seq and RT-qPCR data to show a shift in the lens expression of zebrafish α-crystallins between 5 and 10 days post fertilization (dpf), with 5 and 6 dpf lenses expressing cryaa almost exclusively, and expression ofcryabaandcryabbbecoming more prominent after 10 dpf. These data show thatcryaais the primary α-crystallin during early lens development, while the protective role forcryababecomes more important during lens aging. This study is the first to quantify cataract prevalence in wild-type zebrafish, showing that lens opacities develop in approximately 25% of fish by 18 months of age. None of the three α-crystallin mutants showed a compensatory increase in the expression of the remaining two crystallins, or in the abundant αB1-crystallin. Overall, these findings indicate an ontogenetic shift in the functional importance of individual α-crystallins during zebrafish lens development. Our finding that the lens-specific zebrafish αBa-crystallin plays the leading role in preventing age-related cataract adds a new twist to our understanding of vertebrate lens evolution.

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Section: Discussioncontrasting

confidence: 88%

Section: Discussioncontrasting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Loss of αBa-crystallin, but not αA-crystallin, increases age-related cataract in the zebrafish lens

Posner,

Garver,

Kaye

et al. 2024

Preprint

Self Cite

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show abstract

“…Additionally, in various stress situations, α-crystallin subunits can prevent protein inactivation and neuronal aggregation (Klopstein et al 2012;Derham and Harding 1999;Horwitz et al 1999). The peptide (KFVIFLDVKHFSPEDLTVK, α-crystallin residues 70-88, MAC) inhibited the precipitation and aggregation of unfolding proteins, just like full-length native α-crystallin subunits (Raju et al 2016;Posner et al 2022). According to several researchers, MAC has the same chaperone function as their parent proteins and may be used therapeutically to treat a range of disorders (Sreekumar et al 2013;Zhang et al 2015;Nahomi et al 2013).…”

Section: Introductionmentioning

confidence: 99%

Mini-αA-Crystallin Stifled Melittin-Induced Haemolysis and Lymphocyte Lysis

Tender

Rahangdale

Mohammad

et al. 2023

Int J Pept Res Ther

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Melittin, the most potent pharmacological ingredient of honey bee venom, induces haemolysis, lymphocyte lysis, long-term pain, localised inflammation, and hyperalgesia. In this study, efforts were made to subdue the melittin’s ill effects using a chaperone peptide called ‘mini-αA-crystallin’ (MAC) derived from eye lens αA-crystallin. Haemolytic test on human red blood cells, percentage viability, and DNA diffusion assay on Human peripheral blood lymphocytes (HPBLs) were performed with melittin in the presence or absence of MAC. Propidium iodide and Annexin V-FITC dual staining were performed to analyse quantitative levels of necrotic and apoptotic induction by melittin in the presence or absence of MAC on HPBLs using a flow cytometer. A computational study to find out the interactions between MAC and melittin was undertaken by modelling the structure of MAC using a PEP-FOLD server. The result showed that MAC inhibited melittin-induced lysis in nucleated (lymphocytes) and enucleated (RBC) cells. Flow cytometric analysis revealed a substantial increase in the necrotic and late apoptotic cells after treating HPBLs with melittin (4 µg/ml) for 24 h. Treatment with MAC at a 2:1 molar ratio prevented HPBLs from developing melittin-induced necrosis and late apoptosis. In the docking study, hydrogen, van der Waals, π-π stacking, and salt bridges were observed between the MAC and melittin complex, confirming a strong interaction between them. The MAC-melittin complex was stable during molecular dynamics simulation. These findings may be beneficial in developing a medication for treating severe cases of honeybee stings.

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An insight into the structural analysis of α-crystallin of habitat-specific fish: a computational approach

Chakraborty

Ganguli

et al. 2023

J Proteins Proteom

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α-crystallin is a major eye lens protein, comprising up to 40% of total lens protein. It is composed of two subunits, αA and αB and share a common central domain of about 90 residues with variable N-and C-terminal extensions. For the establishment of an evolutionary inter-relationship, an elucidation of the structure and alignment of protein sequences is crucial. In the present study, a bioinformatics approach was adopted to explore the possible structure, sequence and phylogenetic diversity of α-crystallin (both subunits αA and αB) from ten habitat-speci c sh species, (freshwater and saltwater) and compared with a standard sequence of Bos taurus species. The sequence of Bos taurus was predicted to be a close homologue of the sh species. Homology modelling has been performed in order to generate a possible '3D' structure of the crystallin proteins using SWISS-MODEL. Our analysis shows that the secondary structures of bovine α-crystallin revealed no considerable differences as compared to that of the crystallins of the habitat-speci c sh and that the presence of β-sheets was predominant in all structures. Though no signi cant differences in the αA subunits were revealed yet some structural variations were observed for αB subunits which had been con rmed by MSA analysis. The 3D structure of the protein hasn't been elucidated yet so a computational analysis estimated no major differences in structures of crystallin for either bovine or the sh species except that saltwater sh proteins possess more favourable states and higher reliabilities. In agreement with previous literature, α-crystallin has a molecular weight of 20kDa approx. and a theoretical pI of 5.75; 55.1% of its sequence is composed of hydrophilic amino acids and it is a cytosolic protein. Considerable improvement of the currently available tools is being done for a detailed understanding of the structure/function relationships of α-crystallin proteins.

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Impact of α-crystallin protein loss on zebrafish lens development

Cited by 9 publications

References 58 publications

Loss of αBa-crystallin, but not αA-crystallin, increases age-related cataract in the zebrafish lens

Loss of αBa-crystallin, but not αA-crystallin, increases age-related cataract in the zebrafish lens

Mini-αA-Crystallin Stifled Melittin-Induced Haemolysis and Lymphocyte Lysis

An insight into the structural analysis of α-crystallin of habitat-specific fish: a computational approach

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