Diurnal rhythm of the chromatin protein Hmgb1 in rat photoreceptors is under circadian regulation

Hoppe, George; Rayborn, Mary E.; Sears, Jonathan E.

doi:10.1002/cne.21248

Cited by 20 publications

(26 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In particular, HMGB1 was localized in photoreceptor at the nuclear periphery, and HMGB1 levels were higher in the inner nuclear layer than the outer nuclear layer as opposed to DAPI staining, which preferred to bind to heterochromatic DNA. This was consistent with the previous report 25 that HMGB1 was preferentially colocalized with euchromatin, which was often under active transcription and was stained less by DAPI. Interestingly, HMGB1 appeared to be robustly upregulated in both the photoreceptors and the other retinal cells at day 3 after RD inductions, and DAPI staining was inversely downregulated at the same time ( Figure 2b, e and h).…”

Section: Hmgb1 Is Present In Cultured Retinal Cell and Released Extrasupporting

confidence: 93%

“…Immunofluorescence for HMGB1 and TUNEL Indirect immunofluorescence was carried out as described previously, 19,25 with some modifications. The eyes were harvested and fixed in 4% paraformaldehyde at 41C overnight.…”

Section: Cell Viability Assaymentioning

confidence: 99%

“…As it was reported that HMGB1 in rat photoreceptors had a light-sensitive circadian rhythmic expression, 25 we performed all animal studies on a regular time schedule, and all eyes were set to be almost equally exposed to light. As shown in Figure 2, HMGB1 immunoreactivity was well represented in sections of the normal control rat retina and, as expected, colocalized with DAPI-positive nuclei (Figure 2a, d and g).…”

Section: Hmgb1 Is Present In Cultured Retinal Cell and Released Extramentioning

confidence: 99%

See 2 more Smart Citations

Intraocular expression and release of high-mobility group box 1 protein in retinal detachment

Arimura

Kii

Hashiguchi

et al. 2009

Laboratory Investigation

View full text Add to dashboard Cite

High-mobility group box 1 (HMGB1) protein is a multifunctional protein, which is mainly present in the nucleus and is released extracellularly by dying cells and/or activated immune cells. Although extracellular HMGB1 is thought to be a typical danger signal of tissue damage and is implicated in diverse diseases, its relevance to ocular diseases is mostly unknown. To determine whether HMGB1 contributes to the pathogenesis of retinal detachment (RD), which involves photoreceptor degeneration, we investigated the expression and release of HMGB1 both in a retinal cell death induced by excessive oxidative stress in vitro and in a rat model of RD-induced photoreceptor degeneration in vivo. In addition, we assessed the vitreous concentrations of HMGB1 and monocyte chemoattractant protein 1 (MCP-1) in human eyes with RD. We also explored the chemotactic activity of recombinant HMGB1 in a human retinal pigment epithelial (RPE) cell line. The results show that the nuclear HMGB1 in the retinal cell is augmented by death stress and upregulation appears to be required for cell survival, whereas extracellular release of HMGB1 is evident not only in retinal cell death in vitro but also in the rat model of RD in vivo. Furthermore, the vitreous level of HMGB1 is significantly increased and is correlated with that of MCP-1 in human eyes with RD. Recombinant HMGB1 induced RPE cell migration through an extracellular signalregulated kinase-dependent mechanism in vitro. Our findings suggest that HMGB1 is a crucial nuclear protein and is released as a danger signal of retinal tissue damage. Extracellular HMGB1 might be an important mediator in RD, potentially acting as a chemotactic factor for RPE cell migration that would lead to an ocular pathological wound-healing response.

show abstract

Section: Hmgb1 Is Present In Cultured Retinal Cell and Released Extrasupporting

confidence: 93%

Section: Cell Viability Assaymentioning

confidence: 99%

Section: Hmgb1 Is Present In Cultured Retinal Cell and Released Extramentioning

confidence: 99%

See 1 more Smart Citation

Intraocular expression and release of high-mobility group box 1 protein in retinal detachment

Arimura

Kii

Hashiguchi

et al. 2009

Laboratory Investigation

View full text Add to dashboard Cite

show abstract

“…Previous reports have shown Hmgb1 is enriched in euchromatic regions of photoreceptor nuclei (65). However, Hmgb1 and Hmgb2 are also bound to highly heterochromatic DNA formed during mitosis (66).…”

Section: Discussionmentioning

confidence: 88%

Reciprocal Regulation of the Cardiac Epigenome by Chromatin Structural Proteins Hmgb and Ctcf

Monte

Rosa‐Garrido

Karbassi

et al. 2016

Journal of Biological Chemistry

View full text Add to dashboard Cite

Transcriptome remodeling in heart disease occurs through the coordinated actions of transcription factors, histone modifications, and other chromatin features at pathology-associated genes. The extent to which genome-wide chromatin reorganization also contributes to the resultant changes in gene expression remains unknown. We examined the roles of two chromatin structural proteins, Ctcf (CCCTC-binding factor) and Hmgb2 (high mobility group protein B2), in regulating pathologic transcription and chromatin remodeling. Our data demonstrate a reciprocal relationship between Hmgb2 and Ctcf in controlling aspects of chromatin structure and gene expression. Both proteins regulate each others' expression as well as transcription in cardiac myocytes; however, only Hmgb2 does so in a manner that involves global reprogramming of chromatin accessibility. We demonstrate that the actions of Hmgb2 on local chromatin accessibility are conserved across genomic loci, whereas the effects on transcription are loci-dependent and emerge in concert with histone modification and other chromatin features. Finally, although both proteins share gene targets, Hmgb2 and Ctcf, neither binds these genes simultaneously nor do they physically colocalize in myocyte nuclei. Our study uncovers a previously unknown relationship between these two ubiquitous chromatin proteins and provides a mechanistic explanation for how Hmgb2 regulates gene expression and cellular phenotype. Furthermore, we provide direct evidence for structural remodeling of chromatin on a genome-wide scale in the setting of cardiac disease.

show abstract

“…Hmgb1 levels oscillate in the re nal photoreceptor cells in rats, with protein levels peaking at midday and reaching their minimum late at night [165]. Hmgb1 protein normally colocalises in the nucleus together with acetylated histone H3 (a direct acetyla on target of Clock) in rat photoreceptor cells [89,165].…”

Section: Presence Of Damage In Dna Is a Potent Cue For Adjustment Of mentioning

confidence: 99%

DNA damage and the circadian clock

Chakarov¹,

Petkova²,

Russev³

et al. 2014

Biodiscovery

View full text Add to dashboard Cite

The role of the circadian clock has already been demonstrated for virtually all physiological processes, but it was only recently shown that cells were more sensi ve to DNA damage at specific mes of the day; that the peak of synthesis of mRNA and proteins of genes coding for products involved directly or indirectly in DNA repair was differen ally med in different ssues; and that the growth of some types of cancer followed a circadian pa ern. The paper reviews the specifici es of the clockwork mechanism in living cells associated with repair of DNA damage with regards to its role in ageing and carcinogenesis. The role of heritable polymorhisms and soma c muta ons in the risk for development of common diseases (cancer, but also other types of diseases and condi ons, such as obesity and metabolic syndrome), their course and the possible outcomes is reviewed in animal models and in man. The circadian oscilla ons in the levels of major proteins of DNA-damage related signalling and DNA repair are discussed in rela on to differen al mechanisms of defence against genotoxic damage. The paper outlines the modern concept of 'chronotherapy' -that is, an cancer therapy administered at specific mes of the day/ night cycle that could be associated with be er outcomes in some pa ents and analyses the individual variance in the tolerability of chronotherapy vs. maximum-dose an cancer therapy.Cita on: Chakarov S, Petkova R, Russev GCh, Zhelev N. DNA damage and the circadian clock.

show abstract

Diurnal rhythm of the chromatin protein Hmgb1 in rat photoreceptors is under circadian regulation

Cited by 20 publications

References 63 publications

Intraocular expression and release of high-mobility group box 1 protein in retinal detachment

Intraocular expression and release of high-mobility group box 1 protein in retinal detachment

Reciprocal Regulation of the Cardiac Epigenome by Chromatin Structural Proteins Hmgb and Ctcf

DNA damage and the circadian clock

Contact Info

Product

Resources

About