Human bcl-2 Gene Attenuates the Ability of Rabbit Lens Epithelial Cells against H2O2-induced Apoptosis through Down-regulation of the αB-crystallin Gene

Mao, Ying; Xiang, Hua; Wang, Juan; Korsmeyer, Stanley J.; Reddan, John R.; Li, David Wan‐Cheng

doi:10.1074/jbc.m102195200

Cited by 84 publications

(115 citation statements)

References 63 publications

Supporting

Mentioning

106

Contrasting

Unclassified

Order By: Relevance

“…These expression constructs (pEGFP-HaA and pEGFP-HaB) and the vector (pEGFP-neo) were transfected into the HLE cells using electroporation. 44,45 The stable expression clones of pEGFP-HLE (expressing only GFP from the vector), pEGFP-HaA-HLE (expressing GFP-HaA) and pEGFP-HaB-HLE (expressing GFP-HaB) were obtained after a 6-week selection with G418 (600 mg/ml). As shown in Figure 1, expression of GFP, green fluorescence and human aAcrystallin fusion protein (GFP-HaA) and green fluorescence and human aB-crystallin fusion protein (GFP-HaB) can be detected by fluorescence microscopy.…”

Section: Expression Of Human A-crystallins In Human Lens Epithelial (mentioning

confidence: 99%

“…Its proapoptotic ability can be inhibited by Bcl-2 and Bcl-X L . 38 Another important group of apoptosis regulators are heatshock proteins that include alpha-crystallins (a-crystallins), [39][40][41][42][43][44][45][46] Hsp27, [39][40][47][48][49][50][51][52] Hsp70, [53][54][55][56][57] Hsp90 58 and Hsp60. [59][60] While Hsp60 appears to enhance apoptosis by promoting maturation of procaspase-3, 59,60 the majority of these factors seems to protect cells from induced apoptosis through different mechanisms.…”

Section: Introductionmentioning

confidence: 99%

“…72 More recently, a-crystallins have been shown to prevent induced apoptosis by various factors including staurosporine, [39][40]43 TNF, 39,43 UVA irradiation, 43 okadaic acid 44 and hydrogen peroxide. 45 Regarding the antiapoptotic mechanism, recent studies from our laboratory and another group have demonstrated that aBcrystallin can directly interact with the precursors of caspase-3 to suppress its activation. 45,46 In the present study, we have explored the interactions between a-crystallins and members of the Bcl-2 family.…”

Section: Introductionmentioning

confidence: 99%

“…45 Regarding the antiapoptotic mechanism, recent studies from our laboratory and another group have demonstrated that aBcrystallin can directly interact with the precursors of caspase-3 to suppress its activation. 45,46 In the present study, we have explored the interactions between a-crystallins and members of the Bcl-2 family. Our results demonstrated that human aA-and aB-crystallins (HaA and HaB) can directly bind to Bax and Bcl-X S in vitro and in vivo.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Human αA- and αB-crystallins bind to Bax and Bcl-XS to sequester their translocation during staurosporine-induced apoptosis

et al. 2004

View full text Add to dashboard Cite

aA-and aB-crystallins are distinct antiapoptotic regulators. Regarding the antiapoptotic mechanisms, we have recently demonstrated that aB-crystallin interacts with the procaspase-3 and partially processed procaspase-3 to repress caspase-3 activation. Here, we demonstrate that human aA-and aBcrystallins prevent staurosporine-induced apoptosis through interactions with members of the Bcl-2 family. Using GST pulldown assays and coimmunoprecipitations, we demonstrated that a-crystallins bind to Bax and Bcl-X S both in vitro and in vivo. Human aA-and aB-crystallins display similar affinity to both proapoptotic regulators, and so are true with their antiapoptotic ability tested in human lens epithelial cells, human retina pigment epithelial cells (ARPE-19) and rat embryonic myocardium cells (H9c2) under treatment of staurosporine, etoposide or sorbitol. Two prominent mutants, R116C in aA-crystallin and R120G, in aB-crystallin display much weaker affinity to Bax and Bcl-X S . Through the interaction, a-crystallins prevent the translocation of Bax and Bcl-X S from cytosol into mitochondria during staurosporine-induced apoptosis. As a result, a-crystallins preserve the integrity of mitochondria, restrict release of cytochrome c, repress activation of caspase-3 and block degradation of PARP. Thus, our results demonstrate a novel antiapoptotic mechanism for a-crystallins. Keywords: aA-crystallin; R116C; aB-crystallin; R120G; Bax; Bcl-X S Abbreviations: a-crystallin, alpha-crystallin; GFP, green fluorescence protein; HaA, human aA-crystallin; HaB, human aB-crystallin; GFP-HaA, green fluorescence and human aAcrystallin fusion protein; GFP-HaB, green fluorescence and human aB-crystallin fusion protein; MEM, Eagle's minimal essential medium; PAGE, polyacrylamide gel electrophoresis; PBS, phosphate-buffered saline; PMSF, phenylmethylsufonyl fluoride; HLE, human lens epithelial cells; SDS, sodium dodecylsulfate; TBS, tris-buffered saline; TBS-T, tris-buffered saline with tween-20.

show abstract

Section: Expression Of Human A-crystallins In Human Lens Epithelial (mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Human αA- and αB-crystallins bind to Bax and Bcl-XS to sequester their translocation during staurosporine-induced apoptosis

et al. 2004

View full text Add to dashboard Cite

show abstract

“…Western blot analysis of total proteins from HLECs, MLECs and PC-3 cells without or with transfection were conducted as described previously (Li et al, 2001b(Li et al, , 2003(Li et al, , 2005Mao et al, 2001).…”

Section: Protein Preparation and Western Blot Analysismentioning

confidence: 99%

Protein serine/threonine phosphatase-1 dephosphorylates p53 at Ser-15 and Ser-37 to modulate its transcriptional and apoptotic activities

et al. 2006

View full text Add to dashboard Cite

We have previously demonstrated that the serine/threonine protein phosphatase-1 (PP-1) plays an important role in promoting cell survival. However, the molecular mechanisms by which PP-1 promotes survival remain largely unknown. In the present study, we provide evidence to show that PP-1 can directly dephosphorylate a master regulator of apoptosis, p53, to negatively modulate its transcriptional and apoptotic activities, and thus to promote cell survival. As a transcriptional factor, the function of p53 can be greatly regulated by phosphorylation and dephosphorylation. While the kinases responsible for phosphorylation of the 17 serine/threonine sites have been identified, the dephosphorylation of these sites remains largely unknown. In the present study, we demonstrate that PP-1 can dephosphorylate p53 at Ser-15 and Ser-37 through co-immunoprecipitation, in vitro and in vivo dephosphorylation assays, overexpression and silence of the gene encoding the catalytic subunit for PP-1. We further show that mutations mimicking constitutive dephosphorylation or phosphorylation of p53 at these sites attenuate or enhance its transcriptional activity, respectively. As a result of the changed p53 activity, expression of the downstream apoptosis-related genes such as bcl-2 and bax is accordingly altered and the apoptotic events are either largely abrogated or enhanced. Thus, our results demonstrate that PP-1 directly dephosphorylates p53, and dephosphorylation of p53 has as important impact on its functions as phosphorylation does. In addition, our results reveal that one of the molecular mechanisms by which PP-1 promotes cell survival is to dephosphorylate p53, and thus negatively regulate p53-dependent death pathway.

show abstract

A potential role for β‐ and γ‐crystallins in the vascular remodeling of the eye

Zhang¹,

Gehlbach²,

Gongora³

et al. 2005

Developmental Dynamics

View full text Add to dashboard Cite

We demonstrate that expression of ␤-and ␥-crystallins is associated with intraocular vessels during normal vascular development of the eye and also in the Nuc1 rat, a mutant in which the hyaloid vascular system fails to regress normally. Real-Time RT PCR, Western blot and metabolic labeling studies indicate an increased expression of ␤-and ␥-crystallins in Nuc1 retina. The increased expression of crystallins was localized to the astrocytes surrounding the intraocular vessels. A similar pattern of crystallin expression was also observed in the retinal vessels during normal development. Cultured human astrocytes exposed to 3-nitropropionic acid, an established model of neuronal hypoxia, increased VEGF expression, as expected, but also increased expression of crystallins. Our data suggest that crystallins may function together with VEGF during vascular remodeling. Interestingly, in human PFV (persistent fetal vasculature) disease, where the hyaloid vasculature abnormally persists after birth, we show that astrocytes express both VEGF and crystallins. Developmental Dynamics 234:36 -47, 2005.

show abstract

Human bcl-2 Gene Attenuates the Ability of Rabbit Lens Epithelial Cells against H2O2-induced Apoptosis through Down-regulation of the αB-crystallin Gene

Cited by 84 publications

References 63 publications

Human αA- and αB-crystallins bind to Bax and Bcl-XS to sequester their translocation during staurosporine-induced apoptosis

Human αA- and αB-crystallins bind to Bax and Bcl-XS to sequester their translocation during staurosporine-induced apoptosis

Protein serine/threonine phosphatase-1 dephosphorylates p53 at Ser-15 and Ser-37 to modulate its transcriptional and apoptotic activities

A potential role for β‐ and γ‐crystallins in the vascular remodeling of the eye

Contact Info

Product

Resources

About