scholarly journals Loss of lrrk2 impairs dopamine catabolism, cell proliferation, and neuronal regeneration in the zebrafish brain

2017 ◽  
Author(s):  
Stefano Suzzi ◽  
Reiner Ahrendt ◽  
Stefan Hans ◽  
Svetlana A. Semenova ◽  
Saygın Bilican ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Brain Injury ◽  
Neuronal Regeneration ◽  
Loss Of Function ◽  
Larval Brain ◽  
Stab Injury ◽  
Zebrafish Brain ◽  
Specific Effects ◽  
The Brain

AbstractLRRK2 mutations are a major cause of Parkinson’s disease. Pathogenicity of LRRK2 loss-of-function is controversial, as knockout in rodents reportedly induces no brain-specific effects and knockdown studies in zebrafish are conflicting. Here we show that CRISPR/Cas9-engineered deletion of the ~60-kbp-long zebrafish lrrk2 locus elicits a pleomorphic, albeit transient brain phenotype in maternal-zygotic mutants (mzLrrk2). Intriguingly, 11-month-old mzLrrk2 adults display increased dopamine and serotonin catabolism. Additionally, we find decreased mitosis in the larval brain and reduced stab injury-induced neuronal regeneration in the adult telencephalon. Finally, hypokinesia associates with loss of lrrk2 in larvae. Our results demonstrate that lrrk2 knockout has an early neurodevelopmental effect, and leads to perturbed dopamine and serotonin catabolism in a LRRK2 knockout. We propose mzLrrk2 zebrafish as a valuable tool to study LRRK2 loss-of-function in vivo, and provide a link between LRRK2 and the control of basal cell proliferation in the brain that may become potentially critical upon challenges like brain injury.

scholarly journals CDK13 upregulation-induced formation of the positive feedback loop among circCDK13, miR-212-5p/miR-449a and E2F5 contributes to prostate carcinogenesis

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Jin-Chun Qi ◽  
Zhan Yang ◽  
Tao Lin ◽  
Long Ma ◽  
Ya-Xuan Wang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Transcriptional Activation ◽  
Positive Feedback ◽  
Feedback Loop ◽  
Biological Effects ◽  
Therapeutic Benefit ◽  
Loss Of Function ◽  
Positive Feedback Loop

Abstract Background Both E2F transcription factor and cyclin-dependent kinases (CDKs), which increase or decrease E2F activity by phosphorylating E2F or its partner, are involved in the control of cell proliferation, and some circRNAs and miRNAs regulate the expression of E2F and CDKs. However, little is known about whether dysregulation among E2Fs, CDKs, circRNAs and miRNAs occurs in human PCa. Methods The expression levels of CDK13 in PCa tissues and different cell lines were determined by quantitative real-time PCR and Western blot analysis. In vitro and in vivo assays were preformed to explore the biological effects of CDK13 in PCa cells. Co-immunoprecipitation anlysis coupled with mass spectrometry was used to identify E2F5 interaction with CDK13. A CRISPR-Cas9 complex was used to activate endogenous CDK13 and circCDK13 expression. Furthermore, the mechanism of circCDK13 was investigated by using loss-of-function and gain-of-function assays in vitro and in vivo. Results Here we show that CDK13 is significantly upregulated in human PCa tissues. CDK13 depletion and overexpression in PCa cells decrease and increase, respectively, cell proliferation, and the pro-proliferation effect of CDK13 is strengthened by its interaction with E2F5. Mechanistically, transcriptional activation of endogenous CDK13, but not the forced expression of CDK13 by its expression vector, remarkably promotes E2F5 protein expression by facilitating circCDK13 formation. Further, the upregulation of E2F5 enhances CDK13 transcription and promotes circCDK13 biogenesis, which in turn sponges miR-212-5p/449a and thus relieves their repression of the E2F5 expression, subsequently leading to the upregulation of E2F5 expression and PCa cell proliferation. Conclusions These findings suggest that CDK13 upregulation-induced formation of the positive feedback loop among circCDK13, miR-212-5p/miR-449a and E2F5 is responsible for PCa development. Targeting this newly identified regulatory axis may provide therapeutic benefit against PCa progression and drug resistance.

scholarly journals DJ-1 regulates the integrity and function of ER-mitochondria association through interaction with IP3R3-Grp75-VDAC1

2019 ◽  
Vol 116 (50) ◽  
pp. 25322-25328 ◽  
Author(s):  
Yi Liu ◽  
Xiaopin Ma ◽  
Hisashi Fujioka ◽  
Jun Liu ◽  
Shengdi Chen ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Cellular Mechanism ◽  
Loss Of Function ◽  
Wild Type ◽  
Calcium Efflux ◽  
And Function ◽  
The Brain ◽  
Early Onset Parkinson’S Disease

Loss-of-function mutations in DJ-1 are associated with autosomal recessive early onset Parkinson’s disease (PD), yet the underlying pathogenic mechanism remains elusive. Here we demonstrate that DJ-1 localized to the mitochondria-associated membrane (MAM) both in vitro and in vivo. In fact, DJ-1 physically interacts with and is an essential component of the IP3R3-Grp75-VDAC1 complexes at MAM. Loss of DJ-1 disrupted the IP3R3-Grp75-VDAC1 complex and led to reduced endoplasmic reticulum (ER)-mitochondria association and disturbed function of MAM and mitochondria in vitro. These deficits could be rescued by wild-type DJ-1 but not by the familial PD-associated L166P mutant which had demonstrated reduced interaction with IP3R3-Grp75. Furthermore, DJ-1 ablation disturbed calcium efflux-induced IP3R3 degradation after carbachol treatment and caused IP3R3 accumulation at the MAM in vitro. Importantly, similar deficits in IP3R3-Grp75-VDAC1 complexes and MAM were found in the brain of DJ-1 knockout mice in vivo. The DJ-1 level was reduced in the substantia nigra of sporadic PD patients, which was associated with reduced IP3R3-DJ-1 interaction and ER-mitochondria association. Together, these findings offer insights into the cellular mechanism in the involvement of DJ-1 in the regulation of the integrity and calcium cross-talk between ER and mitochondria and suggests that impaired ER-mitochondria association could contribute to the pathogenesis of PD.

scholarly journals Adenosine kinase inhibition promotes proliferation of neural stem cells after traumatic brain injury

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Hoda M Gebril ◽  
Rizelle Mae Rose ◽  
Raey Gesese ◽  
Martine P Emond ◽  
Yuqing Huo ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Cell Proliferation ◽  
Stem Cell ◽  
Brain Injury ◽  
Neural Stem Cell ◽  
Adenosine Kinase ◽  
Health Concern ◽  
Stem Cell Proliferation ◽  
Neural Stem Cell Proliferation ◽  
The Brain

Abstract Traumatic brain injury (TBI) is a major public health concern and remains a leading cause of disability and socio-economic burden. To date, there is no proven therapy that promotes brain repair following an injury to the brain. In this study, we explored the role of an isoform of adenosine kinase expressed in the cell nucleus (ADK-L) as a potential regulator of neural stem cell proliferation in the brain. The rationale for this hypothesis is based on coordinated expression changes of ADK-L during foetal and postnatal murine and human brain development indicating a role in the regulation of cell proliferation and plasticity in the brain. We first tested whether the genetic disruption of ADK-L would increase neural stem cell proliferation after TBI. Three days after TBI, modelled by a controlled cortical impact, transgenic mice, which lack ADK-L (ADKΔneuron) in the dentate gyrus (DG) showed a significant increase in neural stem cell proliferation as evidenced by significant increases in doublecortin and Ki67-positive cells, whereas animals with transgenic overexpression of ADK-L in dorsal forebrain neurons (ADK-Ltg) showed an opposite effect of attenuated neural stem cell proliferation. Next, we translated those findings into a pharmacological approach to augment neural stem cell proliferation in the injured brain. Wild-type C57BL/6 mice were treated with the small molecule adenosine kinase inhibitor 5-iodotubercidin for 3 days after the induction of TBI. We demonstrate significantly enhanced neural stem cell proliferation in the DG of 5-iodotubercidin-treated mice compared to vehicle-treated injured animals. To rule out the possibility that blockade of ADK-L has any effects in non-injured animals, we quantified baseline neural stem cell proliferation in ADKΔneuron mice, which was not altered, whereas baseline neural stem cell proliferation in ADK-Ltg mice was enhanced. Together these findings demonstrate a novel function of ADK-L involved in the regulation of neural stem cell proliferation after TBI.

scholarly journals ROS-Dependent Neuroprotective Effects of NaHS in Ischemia Brain Injury Involves the PARP/AIF Pathway

2015 ◽  
Vol 36 (4) ◽  
pp. 1539-1551 ◽  
Author(s):  
Qian Yu ◽  
Zhihong Lu ◽  
Lei Tao ◽  
Lu Yang ◽  
Yu Guo ◽  
...  
Keyword(s):  
Brain Injury ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Dependent Manner ◽  
Neuroprotective Effects ◽  
Ht22 Cells ◽  
In Vivo Models ◽  
The Brain

Background/Aims: Stroke is among the top causes of death worldwide. Neuroprotective agents are thus considered as potentially powerful treatment of stroke. Methods: Using both HT22 cells and male Sprague-Dawley rats as in vitro and in vivo models, we investigated the effect of NaHS, an exogenous donor of H2S, on the focal cerebral ischemia-reperfusion (I/R) induced brain injury. Results: Administration of NaHS significantly decreased the brain infarcted area as compared to the I/R group in a dose-dependent manner. Mechanistic studies demonstrated that NaHS-treated rats displayed significant reduction of malondialdehyde content, and strikingly increased activity of superoxide dismutases and glutathione peroxidase in the brain tissues compared with I/R group. The enhanced antioxidant capacity as well as restored mitochondrial function are NaHS-treatment correlated with decreased cellular reactive oxygen species level and compromised apoptosis in vitro or in vivo in the presence of NaHS compared with control. Further analysis revealed that the inhibition of PARP-1 cleavage and AIF translocation are involved in the neuroprotective effects of NaHS. Conclusion: Collectively, our results suggest that NaHS has potent protective effects against the brain injury induced by I/R. NaHS is possibly effective through inhibition of oxidative stress and apoptosis.

scholarly journals MiR199a is implicated in embryo implantation by regulating Grb10 in rat

Reproduction ◽  
2014 ◽  
Vol 147 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Hong-Fei Xia ◽  
Jing-Li Cao ◽  
Xiao-Hua Jin ◽  
Xu Ma
Keyword(s):  
Cell Proliferation ◽  
Embryo Implantation ◽  
Growth Factor Receptor ◽  
Inverse Association ◽  
Loss Of Function ◽  
Endometrial Stromal Cells ◽  
Proliferation And Apoptosis ◽  
17Β Estradiol

MiR199a was found to be differentially expressed in rat uteri between the prereceptive and receptive phase via microRNA (miRNA) microarray analysis in our previous study. However, the role of miR199a in rat embryo implantation remained unknown. In the study, northern blot results showed that the expression levels of miR199a were higher on gestation days 5 and 6 (g.d.5–6) in rat uteri than on g.d.3–4 and g.d.7–8. In situ localization of miR199a in rat uteri showed that miR199a was mainly localized in the stroma or decidua. The expression of miR199a was not significantly different in the uteri of pseudopregnant rats and evidently increased in the uteri of rats subjected to activation of delayed implantation and experimentally induced decidualization. Treatment with 17β-estradiol or both 17β-estradiol and progesterone significantly diminished miR199a levels. Gain of function of miR199a in endometrial stromal cells isolated from rat uteri inhibited cell proliferation and promoted cell apoptosis. Loss of function of miR199a displayed opposite roles on cell proliferation and apoptosis. Further investigation uncovered a significant inverse association between the expression of miR199a and growth factor receptor-bound protein 10 (Grb10), an imprinted gene, and miR199a could bind to the 3′UTR of Grb10 to inhibit Grb10 translation. In addition, in vivo analysis found that the immunostaining of GRB10 was attenuated in the stroma or decidua from g.d.4 to 6, contrary to the enhancement of miR199a. Collectively, upregulation of miR199a in rat uterus during the receptive phase is regulated by blastocyst activation and uterine decidualization. Enforced miR199a expression suppresses cell proliferation partially through targeting Grb10.

scholarly journals Divergent Functions of Tissue-Resident and Blood-Derived Macrophages in the Hemorrhagic Brain

Stroke ◽  
2021 ◽  
Vol 52 (5) ◽  
pp. 1798-1808
Author(s):  
Che-Feng Chang ◽  
Brittany A. Goods ◽  
Michael H. Askenase ◽  
Hannah E. Beatty ◽  
Artem Osherov ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cell ◽  
Autologous Blood ◽  
T Cell Proliferation ◽  
Autologous Blood Injection ◽  
Blood Injection ◽  
Antigen Presenting ◽  
Proliferation Assays ◽  
The Brain

Background and Purpose: Brain tissue-resident microglia and monocyte-derived macrophages (MDMs) are innate immune cells that contribute to the inflammatory response, phagocytosis of debris, and tissue repair after injury. We have previously reported that both microglia and MDMs transition from proinflammatory to reparative phenotypes over days after an intracerebral hemorrhage (ICH). However, their individual functional properties in the brain remain largely unknown. Here we characterized the differences between microglia and MDMs and further elucidate their distinct activation states and functional contributions to the pathophysiology and recovery after ICH. Methods: Autologous blood injection was used to model ICH in mice. Longitudinal transcriptomic analyses on isolated microglia and MDMs from mice at days 1, 3, 7 and 10 after ICH and naive controls identified core transcriptional programs that distinguish these cells. Imaging flow cytometry and in vivo phagocytosis assays were used to study phagocytic ability of microglia and MDMs. Antigen presentation was evaluated by ovalbumin-OTII CD4 T-cell proliferation assays with bone marrow–derived macrophages and primary microglia cultures. Results: MDMs had higher phagocytic activity and higher erythrophagocytosis in the ICH brain. Differential gene expression revealed distinct transcriptional signatures in the MDMs and microglia after ICH. MDMs had higher expression of MHCII (major histocompatibility complex class II) genes than microglia at all time points and greater ability to induce antigen-specific T-cell proliferation. Conclusions: The different ontogeny of microglia and MDMs lead to divergent responses and functions in the inflamed brain as these 2 cell populations differ in phagocytic functions and antigen-presenting capabilities in the brain after ICH.

scholarly journals Neural plate targeting by in utero nanoinjection (NEPTUNE) reveals a role for Sptbn2 in neurulation and abdominal wall closure

2020 ◽  
Author(s):  
Katrin Mangold ◽  
Jan Mašek ◽  
Jingyan He ◽  
Urban Lendahl ◽  
Elaine Fuchs ◽  
...  
Keyword(s):  
Cost Effective ◽  
Cell Types ◽  
Neural Plate ◽  
Spinocerebellar Ataxia Type ◽  
Loss Of Function ◽  
Conditional Expression ◽  
Cost Effective Technique ◽  
The Brain

ABSTRACTGene variants associated with disease are efficiently identified with whole genome sequencing or GWAS, but validation in vivo lags behind. We developed NEPTUNE (neural plate targeting by in utero nanoinjection), to rapidly and flexibly introduce gene expression-modifying viruses to the embryonic murine neural plate prior to neurulation, to target the future adult nervous system. Stable integration in >95% of cells in the brain enabled long-term gain- or loss-of-function, and conditional expression was achieved using mini-promotors for cell types of interest. Using NEPTUNE, we silenced Sptbn2, a gene associated with Spinocerebellar ataxia type 5 (SCA5) in humans. Silencing of Sptbn2 induced severe neural tube defects and embryo resorption, suggesting that SPTBN2 in-frame and missense deletions in SCA5 reflect hypomorphic or neomorphic functions, not loss of function. In conclusion, NEPTUNE offers a novel, rapid and cost-effective technique to test gene function in brain development, and can reveal loss of function phenotypes incompatible with life.

scholarly journals Using zebrafish larval models to study brain injury, locomotor and neuroinflammatory outcomes following intracerebral haemorrhage

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1617
Author(s):  
Siobhan Crilly ◽  
Alexandra Njegic ◽  
Sarah E. Laurie ◽  
Elisavet Fotiou ◽  
Georgina Hudson ◽  
...  
Keyword(s):  
Brain Injury ◽  
Intracerebral Haemorrhage ◽  
Treatment Options ◽  
Brain Cell ◽  
Human Condition ◽  
Fluorescent Reporter ◽  
High Fecundity ◽  
Zebrafish Larvae ◽  
The Brain

Intracerebral haemorrhage (ICH) is a devastating condition with limited treatment options, and current understanding of pathophysiology is incomplete. Spontaneous cerebral bleeding is a characteristic of the human condition that has proven difficult to recapitulate in existing pre-clinical rodent models. Zebrafish larvae are frequently used as vertebrate disease models and are associated with several advantages, including high fecundity, optical translucency and non-protected status prior to 5 days post-fertilisation. Furthermore, other groups have shown that zebrafish larvae can exhibit spontaneous ICH. The aim of this study was to investigate whether such models can be utilised to study the pathological consequences of bleeding in the brain, in the context of pre-clinical ICH research. Here, we compared existing genetic (bubblehead) and chemically inducible (atorvastatin) zebrafish larval models of spontaneous ICH and studied the subsequent disease processes. Through live, non-invasive imaging of transgenic fluorescent reporter lines and behavioural assessment we quantified brain injury, locomotor function and neuroinflammation following ICH. We show that ICH in both zebrafish larval models is comparable in timing, frequency and location. ICH results in increased brain cell death and a persistent locomotor deficit. Additionally, in haemorrhaged larvae we observed a significant increase in macrophage recruitment to the site of injury. Live in vivo imaging allowed us to track active macrophage-based phagocytosis of dying brain cells 24 hours after haemorrhage. Morphological analyses and quantification indicated that an increase in overall macrophage activation occurs in the haemorrhaged brain. Our study shows that in zebrafish larvae, bleeding in the brain induces quantifiable phenotypic outcomes that mimic key features of human ICH. We hope that this methodology will enable the pre-clinical ICH community to adopt the zebrafish larval model as an alternative to rodents, supporting future high throughput drug screening and as a complementary approach to elucidating crucial mechanisms associated with ICH pathophysiology.

scholarly journals Apelin Controls Angiogenesis-Dependent Glioblastoma Growth

2020 ◽  
Vol 21 (11) ◽  
pp. 4179 ◽  
Author(s):  
Anne Frisch ◽  
Stefanie Kälin ◽  
Raymond Monk ◽  
Josefine Radke ◽  
Frank L. Heppner ◽  
...  
Keyword(s):  
Tumor Angiogenesis ◽  
Angiogenic Factor ◽  
Normal Brain ◽  
Loss Of Function ◽  
Direct Infusion ◽  
Tip Cells ◽  
The Brain ◽  
Additional Loss

Glioblastoma (GBM) present with an abundant and aberrant tumor neo-vasculature. While rapid growth of solid tumors depends on the initiation of tumor angiogenesis, GBM also progress by infiltrative growth and vascular co-option. The angiogenic factor apelin (APLN) and its receptor (APLNR) are upregulated in GBM patient samples as compared to normal brain tissue. Here, we studied the role of apelin/APLNR signaling in GBM angiogenesis and growth. By functional analysis of apelin in orthotopic GBM mouse models, we found that apelin/APLNR signaling is required for in vivo tumor angiogenesis. Knockdown of tumor cell-derived APLN massively reduced the tumor vasculature. Additional loss of the apelin signal in endothelial tip cells using the APLN-knockout (KO) mouse led to a further reduction of GBM angiogenesis. Direct infusion of the bioactive peptide apelin-13 rescued the vascular loss-of-function phenotype specifically. In addition, APLN depletion massively reduced angiogenesis-dependent tumor growth. Consequently, survival of GBM-bearing mice was significantly increased when APLN expression was missing in the brain tumor microenvironment. Thus, we suggest that targeting vascular apelin may serve as an alternative strategy for anti-angiogenesis in GBM.

LINP1 promotes the progression of cervical cancer by scaffolding EZH2, LSD1, and DNMT1 to inhibit the expression of KLF2 and PRSS8

2020 ◽  
Vol 98 (5) ◽  
pp. 591-599
Author(s):  
Liuli Wu ◽  
Yuan Gong ◽  
Ting Yan ◽  
Huimin Zhang
Keyword(s):  
Cervical Cancer ◽  
Cell Proliferation ◽  
Inhibitory Effect ◽  
Loss Of Function ◽  
Healthy Human ◽  
Promising Target ◽  
Epithelial Cell Lines ◽  
Key Factor

There is a growing body of evidence indicating that long non-coding RNAs (lncRNAs) are associated with a variety of cancers. LncRNA LINP1 has been shown to be a key factor in tumor malignancy. However, the role of LINP1 in cervical cancer (CC) it is unclear. In our research, we found that the levels of LINP1 were significantly elevated in CC tissues by comparison with adjacent normal tissue. Further, the expression level of LINP1 was upregulated in CC cells compared with healthy human cervical epithelial cell lines (HUCEC). Surprisingly, we found that downregulation of LINP1 significantly reduced the proliferation of CC cells and promoted apoptosis. Additionally, downregulation of LINP1 significantly decreased CC tumor growth in vivo. Further, we observed that LINP1 recruits EZH2, LSD1, and DNMT1, thereby reducing the expression of KLF2 and PRSS8. The results from our qRT–PCR analyses showed that silencing LINP1 uprgulated the expression of KLF2 and PRSS8 in CC cells. The results from our loss-of-function assays showed that upregulation of KLF2 and PRSS8 inhibits cell proliferation and boosts cell apoptosis in CC. We also found that inhibition of KLF2 and PRSS8 reversed the inhibitory effect on cell proliferation associated with silencing LINP1. In short, LINP1 facilitates the progression of CC by suppressing KLF2 and PRSS8, and thus could provide a promising target for CC therapy.

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