Functional analysis of zebrafish microfibril-associated glycoprotein-1 (Magp1) in vivo reveals roles for microfibrils in vascular development and function

AbstractMutations in fibrillin-1 (FBN1) result in Marfan syndrome, demonstrating a critical requirement for microfibrils in vessel structure and function. However, the identity and function of many microfibril-associated molecules essential for vascular development and function have yet to be characterized. In our morpholino-based screen for members of the secretome required for vascular development, we identified a key player in microfibril formation in zebrafish embryogenesis. Microfibril-associated glycoprotein-1 (MAGP1) is a conserved protein found in mammalian and zebrafish microfibrils. Expression of magp1 mRNA is detected in microfibril-producing cells. Analysis of a functional Magp1-mRFP fusion protein reveals localization along the midline and in the vasculature during embryogenesis. Underexpression and overexpression analyses demonstrate that specific Magp1 protein levels are critical for vascular development. Integrin function is compromised in magp1 morphant embryos, suggesting that reduced integrin–matrix interaction is the main mechanism for the vascular defects in magp1 morphants. We further show that Magp1 and fibrillin-1 interact in vivo. This study implicates MAGP1 as a key player in microfibril formation and integrity during development. The essential role for MAGP1 in vascular morphogenesis and function also supports a wide range of clinical applications, including therapeutic targets in vascular disease and cardiovascular tissue engineering.

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DBC1 (Deleted in Breast Cancer 1) modulates the stability and function of the nuclear receptor Rev-erbα

Biochemical Journal ◽

10.1042/bj20121085 ◽

2013 ◽

Vol 451 (3) ◽

pp. 453-461 ◽

Cited By ~ 26

Author(s):

Claudia C. S. Chini ◽

Carlos Escande ◽

Veronica Nin ◽

Eduardo N. Chini

Keyword(s):

Breast Cancer ◽

Nuclear Receptor ◽

Clock Genes ◽

Mrna Levels ◽

Protein Levels ◽

The Stability ◽

And Function ◽

Interfering Rna ◽

In Cells

The nuclear receptor Rev-erbα has been implicated as a major regulator of the circadian clock and integrates circadian rhythm and metabolism. Rev-erbα controls circadian oscillations of several clock genes and Rev-erbα protein degradation is important for maintenance of the circadian oscillations and also for adipocyte differentiation. Elucidating the mechanisms that regulate Rev-erbα stability is essential for our understanding of these processes. In the present paper, we report that the protein DBC1 (Deleted in Breast Cancer 1) is a novel regulator of Rev-erbα. Rev-erbα and DBC1 interact in cells and in vivo, and DBC1 modulates the Rev-erbα repressor function. Depletion of DBC1 by siRNA (small interfering RNA) in cells or in DBC1-KO (knockout) mice produced a marked decrease in Rev-erbα protein levels, but not in mRNA levels. In contrast, DBC1 overexpression significantly enhanced Rev-erbα protein stability by preventing its ubiquitination and degradation. The regulation of Rev-erbα protein levels and function by DBC1 depends on both the N-terminal and C-terminal domains of DBC1. More importantly, in cells depleted of DBC1, there was a dramatic decrease in circadian oscillations of both Rev-erbα and BMAL1. In summary, our data identify DBC1 as an important regulator of the circadian receptor Rev-erbα and proposes that Rev-erbα could be involved in mediating some of the physiological effects of DBC1.

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FKBP51 Modulates Hippocampal Size and Function in Post-translational Regulation of Parkin

10.21203/rs.3.rs-493867/v1 ◽

2021 ◽

Author(s):

Bin Qiu ◽

Zhaohui Zhong ◽

Shawn Righter ◽

Yuxue Xu ◽

Jun Wang ◽

...

Keyword(s):

Hippocampal Neurons ◽

Translational Regulation ◽

Disease Onset ◽

Fold Increase ◽

Knock Out ◽

Fk506 Binding Protein ◽

Protein Levels ◽

And Function

Abstract FK506-binding protein 51 (encoded by Fkpb51) has been associated with stress-related mental illness. To identify its function, we studied the morphological consequences of Fkbp51 deletion. Artificial Intelligence-assist morphological analysis identified that Fkbp51 knock-out (KO) mice possess more elongated CA and DG but shorter in height in coronal section when compared to WT. Primary cultured Fkbp51 KO hippocampal neurons were shown to exhibit larger dendritic outgrowth than wild-type (WT) controls, pharmacological manipulation experiments suggest that this may occur through regulation of microtubule-associated protein. Both in vitro primary culture and in vivo labeling support that FKBP51 regulates microtubule-associated protein expression. Furthermore, in the absence of differences in mRNA expression, Fkbp51 KO hippocampus exhibited decreases in βIII-tubulin, MAP2, and Tau protein levels, but a greater than 2.5-fold increase in Parkin protein. Overexpression and knock-down FKBP51 demonstrated that FKBP51 negatively regulates Parkin in a dose-dependent and ubiquitin-mediated manner. These results indicate a potential novel post-translational regulatory of Parkin by FKBP51 and significance of their interaction on disease onset.

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hPSC-Derived Enteric Ganglioids Model Human ENS Development and Function

10.1101/2022.01.04.474746 ◽

2022 ◽

Author(s):

Homa Majd ◽

Ryan M Samuel ◽

Jonathan T Ramirez ◽

Ali Kalantari ◽

Kevin Barber ◽

...

Keyword(s):

Ex Vivo ◽

Xenograft Model ◽

Developmental Relationships ◽

Drug Candidates ◽

Effective Strategies ◽

Wide Range ◽

Functional Features ◽

And Function

The enteric nervous system (ENS) plays a central role in gut physiology and mediating the crosstalk between the gastrointestinal (GI) tract and other organs. The human ENS has remained elusive, highlighting the need for an in vitro modeling and mapping blueprint. Here we map out the developmental and functional features of the human ENS, by establishing robust and scalable 2D ENS cultures and 3D enteric ganglioids from human pluripotent stem cells (hPSCs). These models recapitulate the remarkable neuronal and glial diversity found in primary tissue and enable comprehensive molecular analyses that uncover functional and developmental relationships within these lineages. As a salient example of the power of this system, we performed in-depth characterization of enteric nitrergic neurons (NO neurons) which are implicated in a wide range of GI motility disorders. We conducted an unbiased screen and identified drug candidates that modulate the activity of NO neurons and demonstrated their potential in promoting motility in mouse colonic tissue ex vivo. We established a high-throughput strategy to define the developmental programs involved in NO neuron specification and discovered that PDGFR inhibition boosts the induction of NO neurons in enteric ganglioids. Transplantation of these ganglioids in the colon of NO neuron-deficient mice results in extensive tissue engraftment, providing a xenograft model for the study of human ENS in vivo and the development of cell-based therapies for neurodegenerative GI disorders. These studies provide a framework for deciphering fundamental features of the human ENS and designing effective strategies to treat enteric neuropathies.

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CSNK2 in cancer: pathophysiology and translational applications

British Journal of Cancer ◽

10.1038/s41416-021-01616-2 ◽

2021 ◽

Author(s):

Scott W. Strum ◽

Laszlo Gyenis ◽

David W. Litchfield

Keyword(s):

Human Cancer ◽

Cell Cycle Control ◽

Prognostic Significance ◽

Hematologic Malignancies ◽

Protein Levels ◽

Wide Range ◽

Positive Treatment ◽

Extensive Body

AbstractProtein kinase CSNK2 (CK2) is a pleiotropic serine/threonine kinase frequently dysregulated in solid and hematologic malignancies. To consolidate a wide range of biological and clinically oriented data from this unique kinase in cancer, this systematic review summarises existing knowledge from in vitro, in vivo and pre-clinical studies on CSNK2 across 24 different human cancer types. CSNK2 mRNA transcripts, protein levels and activity were found to be routinely upregulated in cancer, and commonly identified phosphotargets included AKT, STAT3, RELA, PTEN and TP53. Phenotypically, it frequently influenced evasion of apoptosis, enhancement of proliferation, cell invasion/metastasis and cell cycle control. Clinically, it held prognostic significance across 14 different cancers, and its inhibition in xenograft experiments resulted in a positive treatment response in 12. In conjunction with commentary on preliminary studies of CSNK2 inhibitors in humans, this review harmonises an extensive body of CSNK2 data in cancer and reinforces its emergence as an attractive target for cancer therapy. Continuing to investigate CSNK2 will be crucial to advancing our understanding of CSNK2 biology, and offers the promise of important new discoveries scientifically and clinically.

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In Vivo Ablation of the Conserved GATA-Binding Motif in the Amh Promoter Impairs Amh Expression in the Male Mouse

Endocrinology ◽

10.1210/en.2019-00047 ◽

2019 ◽

Vol 160 (4) ◽

pp. 817-826 ◽

Cited By ~ 6

Author(s):

Marie France Bouchard ◽

Francis Bergeron ◽

Jasmine Grenier Delaney ◽

Louis-Mathieu Harvey ◽

Robert S Viger

Keyword(s):

Developmental Time ◽

Gonadal Development ◽

Conclusive Evidence ◽

Binding Motif ◽

Male Embryo ◽

Steroidogenic Factor 1 ◽

Protein Levels ◽

Positive Modulator ◽

And Function

Abstract GATA4 is an essential transcriptional regulator required for gonadal development, differentiation, and function. In the developing testis, proposed GATA4-regulated genes include steroidogenic factor 1 (Nr5a1), SRY-related HMG box 9 (Sox9), and anti-Müllerian hormone (Amh). Although some of these genes have been validated as genuine GATA4 targets, it remains unclear whether GATA4 is a direct regulator of endogenous Amh transcription. We used a CRISPR/Cas9-based approach to specifically inactivate or delete the sole GATA-binding motif of the proximal mouse Amh promoter. AMH mRNA and protein levels were assessed at developmental time points corresponding to elevated AMH levels: fetal and neonate testes in males and adult ovaries in females. In males, loss of GATA binding to the Amh promoter significantly reduced Amh expression. Although the loss of GATA binding did not block the initiation of Amh transcription, AMH mRNA and protein levels failed to upregulate in the developing fetal and neonate testis. Interestingly, adult male mice presented no anatomical anomalies and had no evidence of retained Müllerian duct structures, suggesting that AMH levels, although markedly reduced, were sufficient to masculinize the male embryo. In contrast to males, GATA binding to the Amh promoter was dispensable for Amh expression in the adult ovary. These results provide conclusive evidence that in males, GATA4 is a positive modulator of Amh expression that works in concert with other key transcription factors to ensure that the Amh gene is sufficiently expressed in a correct spatiotemporal manner during fetal and prepubertal testis development.

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IL-2 administration increases CD4+CD25hi Foxp3+ regulatory T cells in cancer patients

Blood ◽

10.1182/blood-2005-06-2399 ◽

2006 ◽

Vol 107 (6) ◽

pp. 2409-2414 ◽

Cited By ~ 433

Author(s):

Mojgan Ahmadzadeh ◽

Steven A. Rosenberg

Keyword(s):

T Cells ◽

Regulatory T Cells ◽

Interleukin 2 ◽

Selective Inhibition ◽

High Dose ◽

Protein Levels ◽

And Function ◽

The Impact

Abstract Interleukin-2 (IL-2) is historically known as a T-cell growth factor. Accumulating evidence from knockout mice suggests that IL-2 is crucial for the homeostasis and function of CD4+CD25+ regulatory T cells in vivo. However, the impact of administered IL-2 in an immune intact host has not been studied in rodents or humans. Here, we studied the impact of IL-2 administration on the frequency and function of human CD4+CD25hi T cells in immune intact patients with melanoma or renal cancer. We found that the frequency of CD4+CD25hi T cells was significantly increased after IL-2 treatment, and these cells expressed phenotypic markers associated with regulatory T cells. In addition, both transcript and protein levels of Foxp3, a transcription factor exclusively expressed on regulatory T cells, were consistently increased in CD4 T cells following IL-2 treatment. Functional analysis of the increased number of CD4+CD25hi T cells revealed that this population exhibited potent suppressive activity in vitro. Collectively, our results demonstrate that administration of high-dose IL-2 increased the frequency of circulating CD4+CD25hi Foxp3+ regulatory T cells. Our findings suggest that selective inhibition of IL-2-mediated enhancement of regulatory T cells may improve the therapeutic effectiveness of IL-2 administration. (Blood. 2006;107:2409-2414)

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Mesenchymal Stem Cells with Enhanced Bcl-2 Expression Promote Liver Recovery in a Rat Model of Hepatic Cirrhosis

Cellular Physiology and Biochemistry ◽

10.1159/000453166 ◽

2016 ◽

Vol 40 (5) ◽

pp. 1117-1128 ◽

Cited By ~ 11

Author(s):

Shizhu Jin ◽

Hulun Li ◽

Mingzi Han ◽

Mengting Ruan ◽

Zishuai Liu ◽

...

Keyword(s):

Liver Function ◽

Hepatic Cirrhosis ◽

Post Transplantation ◽

Experimental Cirrhosis ◽

Adeno Associated Virus ◽

Protein Levels ◽

Histological Sign ◽

And Function

Background/Aims: Mesenchymal stem cell (MSC) transplantation has emerged as an option for the treatment of chronic hepatic cirrhosis, while its therapeutic efficacy could be improved. The bcl-2 gene is anti-apoptotic and can help cell survival and proliferation. Therefore, we explored whether transplanted MSCs with enhanced bcl-2 expression may be beneficial in the treatment of experimental cirrhosis in rats. Methods: MSCs were isolated from rat bone marrow, expanded in vitro and transfected with adeno-associated virus (AAV) engineered the bcl-2 gene (AAV-bcl-2). Rats with cirrhosis induced by carbon tetrachloride (CCl4) were treated with AAV-bcl-2 infected BMSCs-AAV-bcl-2, with the cells traced in vivo post transplantation. Liver pathology and function were evaluated 7, 14, 21, and 28 days post transplantation, respectively. Results: On day 7 post transplantation, the infused AAV-bcl-2 had integrated into the hepatocyte-like cells (HLCs) that expressed albumin (ALB), Cytokeratin 18 (CK18), and hepatocytes nuclear factor 4a (HNF4a). On day 28 post transplantation, rats in the cirrhosis + BMSCs-AAV-bcl-2 group showed the most dense HLCs, highest mRNA and protein levels of ALB, CK18, and HNF4a, compared to the other groups. Their liver function recovered most rapidly in 4 week observation, while histological sign of cirrhosis remained at the end of this period. Conclusion: BMSCs over expressing bcl-2 gene showed better survival, and enhanced the differentiation into hepatocytes-like cells, and appeared to promote the recovery of liver function in rats with experimental cirrhosis.

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Role of Exosomes in Islet Transplantation

Frontiers in Endocrinology ◽

10.3389/fendo.2021.681600 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jordan Mattke ◽

Srividya Vasu ◽

Carly M. Darden ◽

Kenjiro Kumano ◽

Michael C. Lawrence ◽

...

Keyword(s):

Islet Transplantation ◽

Graft Function ◽

Pancreatic Islet Transplantation ◽

Complex Molecules ◽

Wide Range ◽

And Function ◽

Antigen Presenting

Exosomes are known for their ability to transport nucleic acid, lipid, and protein molecules, which allows for communication between cells and tissues. The cargo of the exosomes can have a variety of effects on a wide range of targets to mediate biological function. Pancreatic islet transplantation is a minimally invasive cell replacement therapy to prevent or reverse diabetes mellitus and is currently performed in patients with uncontrolled type 1 diabetes or chronic pancreatitis. Exosomes have become a focus in the field of islet transplantation for the study of diagnostic markers of islet cell viability and function. A growing list of miRNAs identified from exosomes collected during the process of isolating islets can be used as diagnostic biomarkers of islet stress and damage, leading to a better understanding of critical steps of the isolation procedure that can be improved to increase islet yield and quality. Exosomes have also been implicated as a possible contributor to islet graft rejection following transplantation, as they carry donor major histocompatibility complex molecules, which are then processed by recipient antigen-presenting cells and sensed by the recipient immune cells. Exosomes may find their way into the therapeutic realm of islet transplantation, as exosomes isolated from mesenchymal stem cells have shown promising results in early studies that have seen increased viability and functionality of isolated and grafted islets in vitro as well as in vivo. With the study of exosomes still in its infancy, continued research on the role of exosomes in islet transplantation will be paramount to understanding beta cell regeneration and improving long-term graft function.

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The Amyloid Precursor-like Protein APL-1 Regulates Axon Regeneration

10.1101/305284 ◽

2018 ◽

Cited By ~ 2

Author(s):

Lewie Zeng ◽

Rachid El Bejjani ◽

Marc Hammarlund

Keyword(s):

Motor Neurons ◽

Neuronal Development ◽

Axon Regeneration ◽

Neuronal Response ◽

Small Gtpase ◽

C Elegans ◽

Protein Levels ◽

Mature Neurons ◽

And Function

AbstractMembers of the Amyloid Precursor Protein (APP) family have important functions during neuronal development. However, their physiological functions in the mature nervous system are not fully understood. Here we use the C. elegans GABAergic motor neurons to study the post-developmental function of the APP-like protein APL-1 in vivo. We find that apl-1 has minimum roles in the maintenance of gross neuron morphology and function. However, we show that apl-1 is an inhibitor of axon regeneration, acting on mature neurons to limit regrowth in response to injury. The small GTPase Rab6/RAB-6.2 also inhibits regeneration, and does so in part by maintaining protein levels of APL-1. To inhibit regeneration, APL-1 functions via the E2 domain of its ectodomain; the cytoplasmic tail, transmembrane anchoring, and the E1 domain are not required for this function. Our data defines a novel role for APL-1 in modulating the neuronal response to injury.

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Mitochondrial division, fusion and degradation

The Journal of Biochemistry ◽

10.1093/jb/mvz106 ◽

2019 ◽

Vol 167 (3) ◽

pp. 233-241 ◽

Cited By ~ 4

Author(s):

Daisuke Murata ◽

Kenta Arai ◽

Miho Iijima ◽

Hiromi Sesaki

Keyword(s):

Super Resolution ◽

Healthy Population ◽

Lipid Biochemistry ◽

Mitochondrial Division ◽

Cellular Processes ◽

Size Number ◽

Wide Range ◽

Autophagic Degradation ◽

And Function

Abstract The mitochondrion is an essential organelle for a wide range of cellular processes, including energy production, metabolism, signal transduction and cell death. To execute these functions, mitochondria regulate their size, number, morphology and distribution in cells via mitochondrial division and fusion. In addition, mitochondrial division and fusion control the autophagic degradation of dysfunctional mitochondria to maintain a healthy population. Defects in these dynamic membrane processes are linked to many human diseases that include metabolic syndrome, myopathy and neurodegenerative disorders. In the last several years, our fundamental understanding of mitochondrial fusion, division and degradation has been significantly advanced by high resolution structural analyses, protein-lipid biochemistry, super resolution microscopy and in vivo analyses using animal models. Here, we summarize and discuss this exciting recent progress in the mechanism and function of mitochondrial division and fusion.

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