Early childhood and old age may simply represent periods of physiological and/or genetic susceptibility in the life of an ocular lens. The lamellar/ Marner cataracts (autosomal dominant) that appear in the early childhood or juvenile years best exemplify this. This developmental aberration has been recently linked to mutations in the DNA binding domain of the heat shock transcription factor 4 (HSF4). Our investigations have revealed that HSF4 appears after the initial development of the lens is complete and increases in expression in the postnatal lens. This pattern of expression suggests a remarkable association with the appearance of the lamellar cataracts in the human lens. In order to understand the molecular mechanism that governs this link between the genotype and the pathological phenotype we propose three specific aims (SA) employing BAC (bacterial artificial chromosome) transgenesis that is based on recent revolution in """"""""Recombineering"""""""" techniques for the manipulation of the BACs. In the first specific aim, we propose to delineate the boundaries of the transcriptional unit of the HSF4 gene, characterize its promoter(s) and elucidate the complexity of the different isoforms produced by alternative splicing. In the second SA, we will engineer a reporter (a LacZ or EGFP) into the HSF4 gene residing in BACs, make transgenic mice and follow the expression of the reporter. Because BACs direct correct expression, spatially and temporally, we will be able to pinpoint essential DMA regions in and around the HSF4 gene that are required for the faithful expression in the ocular lens. Using the BAG identified in specific aim #2, in the SA #3 we will create a mouse paradigm of human cataractogenesis by introduction of the same four mutations (reported in the human HSF4 gene) into transgenic mice. We will investigate these mice to find how the quality of the genotype relates to the temporal presentation of the morphological and the molecular phenotype of the ocular lens, allowing us an insight into cataractogenesis and HSF4 gene activity.

National Institute of Health (NIH)
National Eye Institute (NEI)
Research Project (R01)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1-AED (01))
Program Officer
Araj, Houmam H
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of California Los Angeles
Schools of Medicine
Los Angeles
United States
Zip Code
Jing, Zhe; Gangalum, Rajendra K; Bhat, Ankur M et al. (2014) HSF4 mutation p.Arg116His found in age-related cataracts and in normal populations produces childhood lamellar cataract in transgenic mice. Hum Mutat 35:1068-71
Jing, Zhe; Gangalum, Rajendra K; Mock, Dennis C et al. (2014) A gene-specific non-enhancer sequence is critical for expression from the promoter of the small heat shock protein gene ?B-crystallin. Hum Genomics 8:5
Gangalum, Rajendra K; Jing, Zhe; Bhat, Ankur M et al. (2014) Expression of the HSF4 DNA binding domain-EGFP hybrid gene recreates early childhood lamellar cataract in transgenic mice. Invest Ophthalmol Vis Sci 55:7227-40
Gangalum, Rajendra K; Horwitz, Joseph; Kohan, Sirus A et al. (2012) ?A-crystallin and ?B-crystallin reside in separate subcellular compartments in the developing ocular lens. J Biol Chem 287:42407-16
Rao, Narsing A; Saraswathy, Sindhu; Pararajasegaram, Geeta et al. (2012) Small heat shock protein ýýA-crystallin prevents photoreceptor degeneration in experimental autoimmune uveitis. PLoS One 7:e33582
Gangalum, Rajendra K; Bhat, Suraj P (2009) AlphaB-crystallin: a Golgi-associated membrane protein in the developing ocular lens. Invest Ophthalmol Vis Sci 50:3283-90
Nagineni, C N; Bhat, S P (1992) Lens fiber cell differentiation and expression of crystallins in co-cultures of human fetal lens epithelial cells and fibroblasts. Exp Eye Res 54:193-200
Porrello, K; Bhat, S P; Bok, D (1991) Detection of interphotoreceptor retinoid binding protein (IRBP) mRNA in human and cone-dominant squirrel retinas by in situ hybridization. J Histochem Cytochem 39:171-6
Bhat, S P (1990) Synthesis of nucleic acid probes on membrane supports: a procedure for the removal of unincorporated precursors. Anal Biochem 184:59-62
Nagineni, C N; Bhat, S P (1989) Alpha B-crystallin is expressed in kidney epithelial cell lines and not in fibroblasts. FEBS Lett 249:89-94

Showing the most recent 10 out of 11 publications