title: Spatial expression patterns of autophagy genes in the eye lens and induction of autophagy in lens cells.
abstract: OBJECTIVE
  Mutation of the autophagy gene FYVE (named after the four cysteine-rich proteins: Fab 1 [yeast orthologue of PIKfyve], YOTB, Vac 1 [vesicle transport protein], and EEA1) and coiled coil containing 1 (fyco1) causes human cataract suggesting a role for autophagy in lens function. Here, we analyzed the range and spatial expression patterns of lens autophagy genes and we evaluated whether autophagy could be induced in lens cells exposed to stress.
  
  
  METHODS
  Autophagy gene expression levels and their spatial distribution patterns were evaluated between microdissected human lens epithelium and fibers at the mRNA and protein levels by microarray data analysis, real-time PCR and western blot analysis. Selected autophagy protein spatial expression patterns were also examined in newborn mouse lenses by immunohistochemistry. The autophagosomal content of cultured human lens epithelial cells was determined by counting the number of microtubule-associated protein 1 light chain 3B (LC3B)-positive puncta in cells cultured in the presence or absence of serum.
  
  
  RESULTS
  A total of 42 autophagy genes were detected as being expressed by human lens epithelium and fibers. The autophagosomal markers LC3B and FYCO1 were detected throughout the newborn mouse lens. Consistently, the autophagy active form of LC3B (LC3B II) was detected in microdissected human lens fibers. An increased number of LC3B-positive puncta was detected in cultured lens cells upon serum starvation suggesting induction of autophagy in lens cells under stress conditions.
  
  
  CONCLUSIONS
  The data provide evidence that autophagy is an important component for the function of lens epithelial and fiber cells. The data are consistent with the notion that disruption of lens autophagy through mutation or inactivation of specific autophagy proteins could lead to loss of lens resistance to stress and/or loss of lens differentiation resulting in cataract formation.
authors: Department of Biomedical Science, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431, USA.
authors: Lisa Ann
authors: LA
authors: Brennan
authors: Wanda Lee
authors: WL
authors: Kantorow
authors: Daniel
authors: D
authors: Chauss
authors: Rebecca
authors: R
authors: McGreal
authors: Shuying
authors: S
authors: He
authors: Lyndzie
authors: L
authors: Mattucci
authors: Jianning
authors: J
authors: Wei
authors: S Amer
authors: SA
authors: Riazuddin
authors: Ales
authors: A
authors: Cvekl
authors: J Fielding
authors: JF
authors: Hejtmancik
authors: Marc
authors: M
authors: Kantorow
mesh_terms: D000368:Aged; D000818:Animals; D000831:Animals, Newborn; D001343:Autophagy / Q000235:genetics*; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D005136:Eye Proteins / Q000235:genetics* / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D015870:Gene Expression; D020869:Gene Expression Profiling; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007908:Lens, Crystalline / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D044967:Serum / Q000737:chemistry; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D005136:Eye Proteins; C572072:FGD5 protein, human; C460141:FYCO1 protein, human; D020662:Guanine Nucleotide Exchange Factors; C502070:MAP1LC3B protein, human; D008869:Microtubule-Associated Proteins; D020033:Protein Isoforms; D014157:Transcription Factors