scholarly journals Store-independent modulation of Ca2+ entry through Orai by Septin 7

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Bipan Kumar Deb ◽  
Trayambak Pathak ◽  
Gaiti Hasan

Abstract Orai channels are required for store-operated Ca2+ entry (SOCE) in multiple cell types. Septins are a class of GTP-binding proteins that function as diffusion barriers in cells. Here we show that Septin 7 acts as a ‘molecular brake’ on activation of Orai channels in Drosophila neurons. Lowering Septin 7 levels results in dOrai-mediated Ca2+ entry and higher cytosolic Ca2+ in resting neurons. This Ca2+ entry is independent of depletion of endoplasmic reticulum Ca2+ stores and Ca2+ release through the inositol-1,4,5-trisphosphate receptor. Importantly, store-independent Ca2+ entry through Orai compensates for reduced SOCE in the Drosophila flight circuit. Moreover, overexpression of Septin 7 reduces both SOCE and flight duration, supporting its role as a negative regulator of Orai channel function in vivo. Septin 7 levels in neurons can, therefore, alter neural circuit function by modulating Orai function and Ca2+ homeostasis.

2019 ◽  
Author(s):  
Donghoon Lee ◽  
Maiko Kume ◽  
Timothy E Holy

Neural circuit analysis relies on having molecular markers for specific cell types. However, for a cell type identified only by its circuit function, the process of identifying markers remains laborious. Here, we report physiological optical tagging sequencing (PhOTseq), a technique for tagging and expression-profiling cells based on their functional properties. We demonstrate that PhOTseq is capable of selecting rare cell types and enriching them by nearly one hundred-fold. We applied PhOTseq to the challenge of mapping receptor-ligand pairings among vomeronasal pheromone-sensing neurons in mice. Together with in vivo ectopic expression of vomeronasal chemoreceptors, PhOTseq identified the complete combinatorial receptor code for a specific set of ligands, and revealed that the primary sequence of a chemoreceptor was an unexpectedly strong predictor of functional similarity.


Science ◽  
2019 ◽  
Vol 366 (6471) ◽  
pp. 1384-1389 ◽  
Author(s):  
Donghoon Lee ◽  
Maiko Kume ◽  
Timothy E. Holy

Neural circuit analysis relies on having molecular markers for specific cell types. However, for a cell type identified only by its circuit function, the process of identifying markers remains laborious. We developed physiological optical tagging sequencing (PhOTseq), a technique for tagging and expression profiling of cells on the basis of their functional properties. PhOTseq was capable of selecting rare cell types and enriching them by nearly 100-fold. We applied PhOTseq to the challenge of mapping receptor-ligand pairings among pheromone-sensing neurons in mice. Together with in vivo ectopic expression of vomeronasal chemoreceptors, PhOTseq identified the complete combinatorial receptor code for a specific set of ligands.


Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 630
Author(s):  
Huili Lyu ◽  
Cody M. Elkins ◽  
Jessica L. Pierce ◽  
C. Henrique Serezani ◽  
Daniel S. Perrien

Excess inflammation and canonical BMP receptor (BMPR) signaling are coinciding hallmarks of the early stages of injury-induced endochondral heterotopic ossification (EHO), especially in the rare genetic disease fibrodysplasia ossificans progressiva (FOP). Multiple inflammatory signaling pathways can synergistically enhance BMP-induced Smad1/5/8 activity in multiple cell types, suggesting the importance of pathway crosstalk in EHO and FOP. Toll-like receptors (TLRs) and IL-1 receptors mediate many of the earliest injury-induced inflammatory signals largely via MyD88-dependent pathways. Thus, the hypothesis that MyD88-dependent signaling is required for EHO was tested in vitro and in vivo using global or Pdgfrα-conditional deletion of MyD88 in FOP mice. As expected, IL-1β or LPS synergistically increased Activin A (ActA)-induced phosphorylation of Smad 1/5 in fibroadipoprogenitors (FAPs) expressing Alk2R206H. However, conditional deletion of MyD88 in Pdgfrα-positive cells of FOP mice did not significantly alter the amount of muscle injury-induced EHO. Even more surprisingly, injury-induced EHO was not significantly affected by global deletion of MyD88. These studies demonstrate that MyD88-dependent signaling is dispensable for injury-induced EHO in FOP mice.


Gene Therapy ◽  
2021 ◽  
Author(s):  
A. S. Mathew ◽  
C. M. Gorick ◽  
R. J. Price

AbstractGene delivery via focused ultrasound (FUS) mediated blood-brain barrier (BBB) opening is a disruptive therapeutic modality. Unlocking its full potential will require an understanding of how FUS parameters (e.g., peak-negative pressure (PNP)) affect transfected cell populations. Following plasmid (mRuby) delivery across the BBB with 1 MHz FUS, we used single-cell RNA-sequencing to ascertain that distributions of transfected cell types were highly dependent on PNP. Cells of the BBB (i.e., endothelial cells, pericytes, and astrocytes) were enriched at 0.2 MPa PNP, while transfection of cells distal to the BBB (i.e., neurons, oligodendrocytes, and microglia) was augmented at 0.4 MPa PNP. PNP-dependent differential gene expression was observed for multiple cell types. Cell stress genes were upregulated proportional to PNP, independent of cell type. Our results underscore how FUS may be tuned to bias transfection toward specific brain cell types in vivo and predict how those cells will respond to transfection.


Blood ◽  
2009 ◽  
Vol 113 (15) ◽  
pp. 3512-3519 ◽  
Author(s):  
Roberta Caruso ◽  
Carmine Stolfi ◽  
Massimiliano Sarra ◽  
Angelamaria Rizzo ◽  
Massimo C. Fantini ◽  
...  

Abstract IL-25, a member of the IL-17 cytokine family, is known to enhance Th2-like responses associated with increased serum levels of IgE, IgG1, IgA, blood eosinophilia, and eosinophilic infiltrates in various tissues. However, IL-25 also abrogates inflammatory responses driven by Th17 cells. However, the cell types that respond to IL-25 and the mechanisms by which IL-25 differentially regulates immune reactions are not well explored. To identify potential targets of IL-25, we initially examined IL-25 receptor (IL-25R) in human peripheral blood cells. IL-25R was predominantly expressed by CD14+ cells. We next assessed the functional role of IL-25 in modulating the response of CD14+ cells to various inflammatory signals. CD14+ cells responded to IL-25 by down-regulating the synthesis of inflammatory cytokines induced by toll-like receptor (TLR) ligands and inflammatory cytokines. Inhibition of cytokine response by IL-25 occurred via a p38 Map kinase–driven Socs-3–dependent mechanism. In vivo, IL-25 inhibited monocyte-derived cytokines and protected against LPS-induced lethal endotoxemia in mice. These data indicate that IL-25 is a negative regulator of monocyte proinflammatory cytokine responses, which may have therapeutic implications.


2011 ◽  
Vol 286 (41) ◽  
pp. 35915-35921 ◽  
Author(s):  
Liquan Cai ◽  
Binh L. Phong ◽  
Alfred L. Fisher ◽  
Zhou Wang

EAF2, an androgen-regulated protein, interacts with members of the ELL (eleven-nineteen lysine-rich leukemia) transcription factor family and also acts as a tumor suppressor. Although these proteins control transcriptional elongation and perhaps modulate the effects of other transcription factors, the mechanisms of their actions remain largely unknown. To gain new insights into the biology of the EAF2 and ELL family proteins, we used Caenorhabditis elegans as a model to explore the in vivo roles of their worm orthologs. Through the use of transgenic worms, RNAi, and an eaf-1 mutant, we found that both genes are expressed in multiple cell types throughout the worm life cycle and that they play important roles in fertility, survival, and body size regulation. ELL-1 and EAF-1 likely contribute to these activities in part through modulating cuticle synthesis, given that we observed a disrupted cuticle structure in ell-1 RNAi-treated or eaf-1 mutant worms. Consistent with disruption of cuticle structure, loss of either ELL-1 or EAF-1 suppressed the rol phenotype of specific collagen mutants, possibly through the control of dpy-3, dpy-13, and sqt-3 collagen gene expression. Furthermore, we also noted the regulation of collagen expression by ELL overexpression in PC3 human prostate cancer cells. Together, these results reveal important roles for the eaf-1 and ell-1 genes in the regulation of extracellular matrix components.


Author(s):  
Sara Awan ◽  
Magalie Lambert ◽  
Ali Imtiaz ◽  
Fabien Alpy ◽  
Catherine Tomasetto ◽  
...  

Background: Impairment of cellular cholesterol trafficking is at the heart of atherosclerotic lesions formation. This involves egress of cholesterol from the lysosomes and two lysosomal proteins, the Niemann-Pick C1 (NPC1) and NPC2 that promotes cholesterol trafficking. However, movement of cholesterol out the lysosome and how disrupted cholesterol trafficking leads to atherosclerosis is unclear. As the Wnt ligand, Wnt5a inhibits the intracellular accumulation of cholesterol in multiple cell types, we tested whether Wnt5a interacts with the lysosomal cholesterol export machinery and studied its role in atherosclerotic lesions formation. Methods: We generated mice deleted for the Wnt5a gene in vascular smooth muscle cells (VSMCs). To establish whether Wnt5a also protects against cholesterol accumulation in human VSMCs, we used a CRISPR/Cas9 guided nuclease approach to generate human VSMCs knockout for Wnt5a. Results: We show that Wnt5a is a crucial component of the lysosomal cholesterol export machinery. By increasing lysosomal acid lipase expression, decreasing metabolic signaling by the mTORC1 kinase, and through binding to NPC1 and NPC2, Wnt5a senses changes in dietary cholesterol supply and promotes lysosomal cholesterol egress to the endoplasmic reticulum (ER). Consequently, loss of Wnt5a decoupled mTORC1 from variations in lysosomal sterol levels, disrupted lysosomal function, decreased cholesterol content in the ER, and promoted atherosclerosis. Conclusions: These results reveal an unexpected function of the Wnt5a pathway as essential for maintaining cholesterol homeostasis in vivo.


Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1306
Author(s):  
Ann-Kristin Afflerbach ◽  
Mark D. Kiri ◽  
Tahir Detinis ◽  
Ben M. Maoz

The human-relevance of an in vitro model is dependent on two main factors—(i) an appropriate human cell source and (ii) a modeling platform that recapitulates human in vivo conditions. Recent years have brought substantial advancements in both these aspects. In particular, mesenchymal stem cells (MSCs) have emerged as a promising cell source, as these cells can differentiate into multiple cell types, yet do not raise the ethical and practical concerns associated with other types of stem cells. In turn, advanced bioengineered in vitro models such as microfluidics, Organs-on-a-Chip, scaffolds, bioprinting and organoids are bringing researchers ever closer to mimicking complex in vivo environments, thereby overcoming some of the limitations of traditional 2D cell cultures. This review covers each of these advancements separately and discusses how the integration of MSCs into novel in vitro platforms may contribute enormously to clinical and fundamental research.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Tetsuhiro Yokonishi ◽  
Jennifer McKey ◽  
Shintaro Ide ◽  
Blanche Capel

AbstractSpermatogonia, which produce sperm throughout the male lifetime, are regulated inside a niche composed of Sertoli cells, and other testis cell types. Defects in Sertoli cells often lead to infertility, but replacement of defective cells has been limited by the inability to deplete the existing population. Here, we use an FDA-approved non-toxic drug, benzalkonium chloride (BC), to deplete testis cell types in vivo. Four days after BC administration, Sertoli cells are preferentially depleted, and can be replaced to promote spermatogenesis from surviving (host) spermatogonia. Seven days after BC treatment, multiple cell types can be engrafted from fresh or cryopreserved testicular cells, leading to complete spermatogenesis from donor cells. These methods will be valuable for investigation of niche-supporting cell interactions, have the potential to lead to a therapy for idiopathic male infertility in the clinic, and could open the door to production of sperm from other species in the mouse.


Blood ◽  
2012 ◽  
Vol 119 (2) ◽  
pp. 573-582 ◽  
Author(s):  
Roland Csépányi-Kömi ◽  
Gábor Sirokmány ◽  
Miklós Geiszt ◽  
Erzsébet Ligeti

Members of the Rac/Rho family of small GTPases play an essential role in phagocytic cells in organization of the actin cytoskeleton and production of toxic oxygen compounds. GTPase-activating proteins (GAPs) decrease the amount of the GTP-bound active form of small GTPases, and contribute to the control of biologic signals. The number of potential Rac/RhoGAPs largely exceeds the number of Rac/Rho GTPases and the expression profile, and their specific role in different cell types is largely unknown. In this study, we report for the first time the properties of full-length ARHGAP25 protein, and show that it is specifically expressed in hematopoietic cells, and acts as a RacGAP both in vitro and in vivo. By silencing and overexpressing the protein in neutrophil model cell lines (PLB-985 and CosPhoxFcγR, respectively) and in primary macrophages, we demonstrate that ARHGAP25 is a negative regulator of phagocytosis acting probably via modulation of the actin cytoskeleton.


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