scholarly journals A Comparative Analysis of Gene and Protein Expression Throughout a Full 28-Day Retinal Regeneration Time-Course in Adult Zebrafish

2021 ◽  
Vol 9 ◽  
Author(s):  
Ashley C. Kramer ◽  
Katherine Gurdziel ◽  
Ryan Thummel
Keyword(s):  
Cell Cycle ◽  
Time Course ◽  
Light Exposure ◽  
Transcriptional Profiling ◽  
Retinal Regeneration ◽  
Adult Zebrafish ◽  
Regeneration Time ◽  
Gene And Protein Expression ◽  
Progenitor Cell Proliferation ◽  
Complete Regeneration

Following photoreceptors ablation by intense light exposure, adult zebrafish are capable of complete regeneration due to the ability of their Müller glia (MG) to re-enter the cell cycle, creating progenitors that differentiate into new photoreceptors. The majority of previous reports on retinal regeneration focused on the first few days of the regenerative response, which include MG cell-cycle re-entry and progenitor cell proliferation. With this study, we analyzed the full 28-day time-course of regeneration by pairing a detailed morphological/immunological analysis with RNA-seq transcriptional profiling at 8 key time points during retinal regeneration. We observed several novel findings. First, we provide evidence for two separate peaks of MG gliosis, with the secondary gliotic peak occurring after MG cell-cycle re-entry. Second, we highlight a distinct transcriptional shift between 5- and 10-days post lesion that highlights the transition from progenitor proliferation to differentiation into new photoreceptors. Third, we show distinctly different patterns of transcriptional recovery of the photoreceptor opsins at 28 days post lesion. Finally, using differential gene expression analysis, we revealed that the established functional recovery of the retina at 28 days post lesion does not, in fact, return to an undamaged transcriptional state, potentially redefining what the field considers complete regeneration. Together, to our knowledge, this work represents the first histological and transcriptomic map of a 28-day time-course of retinal regeneration in adult zebrafish.

scholarly journals Characterization of retinal regeneration in adult zebrafish following multiple rounds of phototoxic lesion

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5646 ◽  
Author(s):  
Alexandra H. Ranski ◽  
Ashley C. Kramer ◽  
Gregory W. Morgan ◽  
Jennifer L. Perez ◽  
Ryan Thummel
Keyword(s):  
Cell Cycle ◽  
Cellular Localization ◽  
Ganglion Cells ◽  
Plexiform Layer ◽  
Inner Plexiform Layer ◽  
Muller Glia ◽  
Müller Glia ◽  
Light Damage ◽  
Retinal Regeneration ◽  
Adult Zebrafish

Müller glia in the zebrafish retina respond to retinal damage by re-entering the cell cycle, which generates large numbers of retinal progenitors that ultimately replace the lost neurons. In this study we compared the regenerative outcomes of adult zebrafish exposed to one round of phototoxic treatment with adult zebrafish exposed to six consecutive rounds of phototoxic treatment. We observed that Müller glia continued to re-enter the cell cycle to produce clusters of retinal progenitors in zebrafish exposed to multiple rounds of phototoxic light. Some abnormalities were noted, however. First, we found that retinas exposed to multiple rounds of damage exhibited a greater loss of photoreceptors at 36 hours of light damage than retinas that were exposed to their first round of light damage. In addition, we found that Müller glia appeared to have an increase in the acute gliotic response in retinas exposed to multiple rounds of light treatment. This was evidenced by cellular hypertrophy, changes in GFAP cellular localization, and transient increases in stat3 and gfap expression. Finally, following the sixth round of phototoxic lesion, we observed a significant increase in mis-localized HuC/D-positive amacrine and ganglion cells in the inner plexiform layer and outer retina, and a decreased number of regenerated blue cone photoreceptors. These data add to recent findings that retinal regeneration in adult zebrafish occurs concomitant with Müller glia reactivity and can result in the generation of aberrant neurons. These data are also the first to demonstrate that Müller glia appear to modify their phenotype in response to multiple rounds of phototoxic lesion, exhibiting an increase in acute gliosis while maintaining a remarkable capacity for long-term regeneration of photoreceptors.

scholarly journals Critical Effects on Akt Signaling in Adult Zebrafish Brain Following Alterations in Light Exposure

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 637
Author(s):  
Nicholas S. Moore ◽  
Robert A. Mans ◽  
Mackenzee K. McCauley ◽  
Colton S. Allgood ◽  
Keri A. Barksdale
Keyword(s):  
Optic Tectum ◽  
Visual Processing ◽  
Environmental Enrichment ◽  
Glycogen Synthase ◽  
Light Exposure ◽  
Hsp70 Expression ◽  
Light Cycle ◽  
Adult Zebrafish ◽  
Sleep State ◽  
Zebrafish Brain

Evidence from human and animal studies indicate that disrupted light cycles leads to alterations of the sleep state, poor cognition, and the risk of developing neuroinflammatory and generalized health disorders. Zebrafish exhibit a diurnal circadian rhythm and are an increasingly popular model in studies of neurophysiology and neuropathophysiology. Here, we investigate the effect of alterations in light cycle on the adult zebrafish brain: we measured the effect of altered, unpredictable light exposure in adult zebrafish telencephalon, homologous to mammalian hippocampus, and the optic tectum, a significant visual processing center with extensive telencephalon connections. The expression of heat shock protein-70 (HSP70), an important cell stress mediator, was significantly decreased in optic tectum of adult zebrafish brain following four days of altered light exposure. Further, pSer473-Akt (protein kinase B) was significantly reduced in telencephalon following light cycle alteration, and pSer9-GSK3β (glycogen synthase kinase-3β) was significantly reduced in both the telencephalon and optic tectum of light-altered fish. Animals exposed to five minutes of environmental enrichment showed significant increase in pSer473Akt, which was significantly attenuated by four days of altered light exposure. These data show for the first time that unpredictable light exposure alters HSP70 expression and dysregulates Akt-GSK3β signaling in the adult zebrafish brain.

Plant-specific regulation of replication protein�A2 (OsRPA2) from rice during the cell cycle and in response to ultraviolet light exposure

Planta ◽  
2003 ◽  
Vol 217 (3) ◽  
pp. 457-465 ◽  
Author(s):  
Tanja Marwedel ◽  
Toyotaka Ishibashi ◽  
Ren� Lorbiecke ◽  
Silke Jacob ◽  
Kengo Sakaguchi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ultraviolet Light ◽  
Light Exposure ◽  
Replication Protein ◽  
Specific Regulation

scholarly journals Histone chaperone HIRA regulates neural progenitor cell proliferation and neurogenesis via β-catenin

2017 ◽  
Vol 216 (7) ◽  
pp. 1975-1992 ◽  
Author(s):  
Yanxin Li ◽  
Jianwei Jiao
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Progenitor Cell ◽  
Neural Progenitor Cells ◽  
Neural Progenitor Cell ◽  
Neural Progenitor ◽  
Histone Chaperone ◽  
Epigenetic Mechanism ◽  
Progenitor Cell Proliferation ◽  
Early Neurogenesis

Histone cell cycle regulator (HIRA) is a histone chaperone and has been identified as an epigenetic regulator. Subsequent studies have provided evidence that HIRA plays key roles in embryonic development, but its function during early neurogenesis remains unknown. Here, we demonstrate that HIRA is enriched in neural progenitor cells, and HIRA knockdown reduces neural progenitor cell proliferation, increases terminal mitosis and cell cycle exit, and ultimately results in premature neuronal differentiation. Additionally, we demonstrate that HIRA enhances β-catenin expression by recruiting H3K4 trimethyltransferase Setd1A, which increases H3K4me3 levels and heightens the promoter activity of β-catenin. Significantly, overexpression of HIRA, HIRA N-terminal domain, or β-catenin can override neurogenesis abnormities caused by HIRA defects. Collectively, these data implicate that HIRA, cooperating with Setd1A, modulates β-catenin expression and then regulates neurogenesis. This finding represents a novel epigenetic mechanism underlying the histone code and has profound and lasting implications for diseases and neurobiology.

scholarly journals Loss of Melanopsin (OPN4) Leads to a Faster Cell Cycle Progression and Growth in Murine Melanocytes

2021 ◽  
Vol 43 (3) ◽  
pp. 1436-1450
Author(s):  
Leonardo Vinícius Monteiro de Assis ◽  
Maria Nathália Moraes ◽  
Davi Mendes ◽  
Matheus Molina Silva ◽  
Carlos Frederico Martins Menck ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Population Analysis ◽  
Cell Populations ◽  
Specific Cell ◽  
Significant Modification ◽  
M Cell ◽  
Cycle Progression ◽  
Gene And Protein Expression ◽  
Independent Functions

Skin melanocytes harbor a complex photosensitive system comprised of opsins, which were shown, in recent years, to display light- and thermo-independent functions. Based on this premise, we investigated whether melanopsin, OPN4, displays such a role in normal melanocytes. In this study, we found that murine Opn4KO melanocytes displayed a faster proliferation rate compared to Opn4WT melanocytes. Cell cycle population analysis demonstrated that OPN4KO melanocytes exhibited a faster cell cycle progression with reduced G0–G1, and highly increased S and slightly increased G2/M cell populations compared to the Opn4WT counterparts. Expression of specific cell cycle-related genes in Opn4KO melanocytes exhibited alterations that corroborate a faster cell cycle progression. We also found significant modification in gene and protein expression levels of important regulators of melanocyte physiology. PER1 protein level was higher while BMAL1 and REV-ERBα decreased in Opn4KO melanocytes compared to Opn4WT cells. Interestingly, the gene expression of microphthalmia-associated transcription factor (MITF) was upregulated in Opn4KO melanocytes, which is in line with a higher proliferative capability. Taken altogether, we demonstrated that OPN4 regulates cell proliferation, cell cycle, and affects the expression of several important factors of the melanocyte physiology; thus, arguing for a putative tumor suppression role in melanocytes.

TGFbeta1 induces a cell-cycle-dependent increase in motility of epithelial cells

1999 ◽  
Vol 112 (4) ◽  
pp. 447-454 ◽  
Author(s):  
D. Zicha ◽  
E. Genot ◽  
G.A. Dunn ◽  
I.M. Kramer
Keyword(s):  
Cell Cycle ◽  
Mass Distribution ◽  
Transforming Growth Factor Beta ◽  
Time Course ◽  
Transforming Growth Factor ◽  
Interference Microscopy ◽  
Response To Treatment ◽  
Gradual Onset ◽  
The Difference ◽  
Cycle Dependent

We have previously shown that addition of type 1 transforming growth factor-beta (TGFbeta1) to an exponentially growing population of mink lung CCl64 cells increases their average intermitotic time from 14.4 to 20.3 hours, predominantly by extending G1 from 7.5 to 13.5 hours. Here we have used the DRIMAPS system (digitally recorded interference microscopy with automatic phase-shifting) for obtaining data on cellular mass distribution, cell motility and morphology. We found no significant change in the cells' rate of mass increase following TGFbeta1 treatment, which implies that the treated cells attained a higher mass during their extended cell cycle and this was confirmed by direct measurement of cell size. However, the cells showed a dramatic motile response to treatment: TGFbeta1-treated cells had a significantly higher time-averaged speed of 36.2 microm hour-1 compared to 14.5 microm hour-1 for the control cells. The time course of the response was gradual, reaching a maximum mean speed of 52.6 microm hour-1 after 15 hours exposure. We found that the gradual onset of the response was probably not due to a slow accumulation of a secondary factor but because cells were dividing throughout the experiment and most of the response to TGFbeta1 occurred only after the first cell division in its presence. Thus, taking only those cells that had not yet divided, the time-averaged speed of treated cells (26.1 micrometer hour-1) was only moderately higher than that of untreated cells (14.9 micrometer hour-1) whereas, for those cells that had divided, the difference in speed between treated cells (45.1 micrometer hour-1) and untreated cells (14.1 microm hour-1) was much greater. Increased speed was a consequence of enhanced protrusion and retraction of the cell margin coupled with an increase in cell polarity. TGFbeta1 also increased the mean spreading of the cells, measured as area-to-mass ratio, from 3.2 to 4.4 micrometer2 pg-1, and the intracellular mass distribution became more asymmetric. The observations indicate that a G2 signal may be necessary to reach maximal motility in the presence of TGFbeta1.

Abstract 20134: Transcriptional Profiling Identifies Candidate Regulators of Neonatal Heart Regeneration

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Caitlin O’Meara ◽  
Joseph Wamstad ◽  
Laurie Boyer ◽  
Richard T Lee
Keyword(s):  
Cell Cycle ◽  
Transcriptional Profiling ◽  
Cardiac Regeneration ◽  
Heart Regeneration ◽  
Transcriptional Signature ◽  
Adult Mice ◽  
Neonatal Heart ◽  
Sirna Knockdown

Some higher organisms, such as zebrafish and neonatal mice, are capable of complete and sufficient regeneration of the myocardium following injury, which is thought to occur primarily by proliferation of pre-existing cardiomyocytes. Although adult humans and adult mice lack this cardiac regeneration potential, there is great interest in understanding how regeneration can occur in the heart so that we can activate this process in humans suffering from heart failure. The aim of our study was to identify mechanisms by which mature, post-mitotic adult cardiomyocytes can re-enter the cell cycle to ultimately facilitate heart regeneration following injury. We derived a core transcriptional signature of injury-induced cardiomyocyte regeneration in mouse by comparing global transcriptional programs in a dynamic model of in vitro and in vivo cardiomyocyte differentiation and in an in vitro cardiomyocyte explant model, as well as a neonatal heart resection model. We identified a panel of transcription factors, growth factors, and cytokines, whose expression significantly correlated with the differentiated state of the cell in all datasets examined, suggesting that these factors play a role in regulating cardiomyocyte cell state. Furthermore, potential upstream regulators of core differentially expressed networks were identified using Ingenuity Pathway Analysis and we found that one predicted regulator, interleukin-13 (IL13), significantly induced cardiomyocyte cell cycle activity and STAT6/STAT3 signaling in vitro. siRNA knockdown experiments demonstrated that STAT3/periostin and STAT6 signaling are critical for cardiomyocyte cell cycle activity in response to IL13. These data reveal novel insights into the transcriptional regulation of mammalian heart regeneration and provide the founding circuitry for identifying potential regulators for stimulating cardiomyocyte cell cycle activity.

PCNA and total nuclear protein content as markers of cell proliferation in pea tissue

1992 ◽  
Vol 102 (1) ◽  
pp. 71-78 ◽  
Author(s):  
SANDRA CITTERIO ◽  
SERGIO SGORBATI ◽  
MARISA LEVI ◽  
BRUNO MARIA COLOMBO ◽  
ELIO SPARVOLI
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Protein Content ◽  
Time Course ◽  
Nuclear Protein ◽  
Flow Cytometric Analysis ◽  
Nuclear Antigen ◽  
Cycle Phase ◽  
Proliferating Cells ◽  
Embryo Cells

The identification of cell proliferation markers has been shown to be a useful tool with which to study basic mechanisms of cell cycle progression. The use of immunofluorescence techniques revealed the presence of the proliferating cell nuclear antigen (PCNA) in pea tissue, where we observed a high PCNA expression in proliferating cells of the root meristem compared to noncycling cells of the differentiated leaf. The presence of PCNA was monitored also during the time-course of seed germination, before, during and after the cell cycle resumption of the embryo cells. PCNA is present in embryo cells not only during and after resumption of the cell cycle but also before, when cells have not yet begun replicating their genome. A bivariate flow cytometric analysis of DNA and nuclear protein content was used to localize precisely the cells of the examined pea tissues in different cell cycle phase subcompartments. A high correlation was found between the degree of cell proliferation and the protein content of G1 nuclei, on the one hand, and the percentage of PCNA positive cells on the other.

Reorganization of connectivity in amphibian central auditory system following VIIIth nerve regeneration: time course

1983 ◽  
Vol 49 (6) ◽  
pp. 1410-1427 ◽  
Author(s):  
H. H. Zakon
Keyword(s):  
Time Course ◽  
Contralateral Side ◽  
Excitatory Input ◽  
Regeneration Time ◽  
Tuning Curves ◽  
Auditory Afferents ◽  
Viiith Nerve ◽  
Dorsal Medullary Nucleus ◽  
Olivary Nucleus ◽  
Made In

In the frog, most neurons in the primary (dorsal medullary nucleus, DMN) and secondary (superior olivary nucleus, SO) auditory nuclei have V-shaped tuning curves, almost as narrowly tuned as those recorded in the nerve. Thus, the innervation pattern is such that if more than one excitatory afferent innervates a postsynaptic cell, they must all possess similar best frequencies (BFs). Similarly, binaural cells in these nuclei display matched frequency selectivities when acoustically stimulated via either ear. The VIIIth nerve was unilaterally severed and allowed to regenerate back into the DMN. At various postoperative intervals, extracellular single-unit recordings were made in the SO contralateral to the regenerated nerve, as that nucleus receives its dominant excitatory input (approximately 80%) from the contralateral side. Recordings were also made in the SO of a number of unoperated control animals. Functional reinnervation commenced between 4 and 5 wk postoperatively and by 6 wk, a normal innervation density, as judged by physiological criteria, was achieved. Single units of any best frequency represented within the frog's two auditory papillae could be recorded during earliest reinnervation. In general, the tuning curves of both monaural and binaural cells were V shaped in the 6 wk regenerates. Although many tuning curves were narrowly tuned (Q10dB greater than 1.0) as in unoperated animals, some were very broadly tuned (Q10dB less than 0.5). The mean Q10dB value for all contralaterally excited cells was 1.45 +/- 0.77 (SD), which was significantly lower than that of SO units in unoperated frogs (Q10dB = 1.66 +/- 0.52 (SD)). Binaural cells often had mismatched BFs and tuning curves. By 8 wk after nerve transection, tuning curves were as narrow as in unoperated animals (Q10dB = 1.64 +/- 0.68 (SD)), and the BFs of binaural cells evinced a greater match than at 6 wk. By 12 wk postoperatively, V-shaped tuning curves were still as narrow as in controls (Q10dB = 1.71 +/- 0.69 (SD)), and the tuning curves and BFs of binaural cells were well matched again. At all postoperative intervals, about 10% of the tuning curves in the SO of regenerates were W shaped. This was never seen in normal animals. The return of narrow V-shaped tuning curves in the majority of neurons and the recurrence of matched binaural cells in the SO are interpreted as evidence of specificity for potential postsynaptic targets in the DMN by regenerating auditory afferents.

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