scholarly journals Identification of the cell-type-specific ER membrane protein Tanmp expressed in hypothalamic tanycytes and subsets of neurons

2021 ◽  
Author(s):  
Osamu Takahashi ◽  
Mayuko Tanahashi ◽  
Saori Yokoi ◽  
Mari Kaneko ◽  
Tomoko Tokuhara ◽  
...  

Genomes of higher eukaryotes encode many uncharacterized proteins, and the functions of these proteins cannot be predicted from the primary sequences due to a lack of conserved functional domains. During a screening of novel noncoding RNAs abundantly expressed in mouse brains, we incidentally identified a gene termed Tanmp, which encoded an endoplasmic reticulum (ER) protein without known functional domains. Tanmp is specifically expressed in the nervous system, and the highest expression was observed in a specialized cell type called tanycyte that aligns the ventral wall of the third ventricle in the hypothalamus. Immunostaining of Tanmp revealed the fine morphology of tanycytes with highly branched apical ER membranes. Immunoprecipitation revealed that Tanmp associates with mitochondrial ATPase at least in vitro, and ER and mitochondrial signals occasionally overlapped in tanycytes. Mutant mice lacking Tanmp did not exhibit overt phenotypes, suggesting that Tanmp is not essential in mice reared under normal laboratory conditions. We also found that RNA probes that are predicted to uniquely detect Tanmp mRNA cross-reacted with uncharacterized RNAs, highlighting the importance of experimental validation of the specificity of probes during the hybridization-based study of RNA localization.

2021 ◽  
Author(s):  
Alexei M. Bygrave ◽  
Ayesha Sengupta ◽  
Ella P. Jackert ◽  
Mehroz Ahmed ◽  
Beloved Adenuga ◽  
...  

Synapses in the brain exhibit cell–type–specific differences in basal synaptic transmission and plasticity. Here, we evaluated cell–type–specific differences in the composition of glutamatergic synapses, identifying Btbd11, as an inhibitory interneuron–specific synapse–enriched protein. Btbd11 is highly conserved across species and binds to core postsynaptic proteins including Psd–95. Intriguingly, we show that Btbd11 can undergo liquid–liquid phase separation when expressed with Psd–95, supporting the idea that the glutamatergic post synaptic density in synapses in inhibitory and excitatory neurons exist in a phase separated state. Knockout of Btbd11 from inhibitory interneurons decreased glutamatergic signaling onto parvalbumin–positive interneurons. Further, both in vitro and in vivo, we find that Btbd11 knockout disrupts network activity. At the behavioral level, Btbd11 knockout from interneurons sensitizes mice to pharmacologically induced hyperactivity following NMDA receptor antagonist challenge. Our findings identify a cell–type–specific protein that supports glutamatergic synapse function in inhibitory interneurons–with implication for circuit function and animal behavior.


2000 ◽  
Vol 72 (2) ◽  
pp. 226 ◽  
Author(s):  
René C. Krieg ◽  
Sonja Fickweiler ◽  
Otto S. Wolfbeis ◽  
Ruth Knuechel

2018 ◽  
Vol 115 (20) ◽  
pp. 5253-5258 ◽  
Author(s):  
Hideyuki Yanai ◽  
Shiho Chiba ◽  
Sho Hangai ◽  
Kohei Kometani ◽  
Asuka Inoue ◽  
...  

IFN regulatory factor 3 (IRF3) is a transcription regulator of cellular responses in many cell types that is known to be essential for innate immunity. To confirm IRF3’s broad role in immunity and to more fully discern its role in various cellular subsets, we engineered Irf3-floxed mice to allow for the cell type-specific ablation of Irf3. Analysis of these mice confirmed the general requirement of IRF3 for the evocation of type I IFN responses in vitro and in vivo. Furthermore, immune cell ontogeny and frequencies of immune cell types were unaffected when Irf3 was selectively inactivated in either T cells or B cells in the mice. Interestingly, in a model of lipopolysaccharide-induced septic shock, selective Irf3 deficiency in myeloid cells led to reduced levels of type I IFN in the sera and increased survival of these mice, indicating the myeloid-specific, pathogenic role of the Toll-like receptor 4–IRF3 type I IFN axis in this model of sepsis. Thus, Irf3-floxed mice can serve as useful tool for further exploring the cell type-specific functions of this transcription factor.


2007 ◽  
Vol 72 (2) ◽  
pp. 226-233 ◽  
Author(s):  
René C. Krieg ◽  
Sonja Fickweiler ◽  
Otto S. Wolfbeis ◽  
Ruth Knuechel

2008 ◽  
Vol 314 (10) ◽  
pp. 2016-2027 ◽  
Author(s):  
Christina Warnecke ◽  
Alexander Weidemann ◽  
Melanie Volke ◽  
Ruth Schietke ◽  
Xiaoqing Wu ◽  
...  

1998 ◽  
Vol 18 (5) ◽  
pp. 521-530 ◽  
Author(s):  
Susan A. Lyons ◽  
Helmut Kettenmann

The major classes of glial cells, namely astrocytes, oligodendrocytes, and microglial cells were compared in parallel for their susceptibility to damage after combined hypoxia and hypoglycemia or hypoxia alone. The three glial cell types were isolated from neonatal rat brains, separated, and incubated in N2/CO2-gassed buffer-containing glucose or glucose substitutes, 2-deoxyglucose or mannitol (both nonmetabolizable sugars). The damage to the cells after 6 hours' exposure was determined at 0, 1, 3, 7 days based on release of lactate dehydrogenase and counting of ethidium bromide–stained dead cells, double-stained with cell-type specific markers. When 2-deoxyglucose replaced glucose during 6 hours of hypoxia, both oligodendrocytes and microglia rarely survived (18% and 12%, respectively). Astroglia initially increased the release of lactate dehydrogenase but maintained 98% to 99% viability. When mannitol, a radical scavenger and osmolarity stabilizer, replaced glucose during 6 hours of hypoxia, oligodendrocytes rarely survived (10%), astroglia survival remained at 99%, but microglia survival increased to 50%. After exposure to 6 and 42 hours, respectively, of hypoxic conditions alone, oligodendrocytes exhibited 10% survival whereas microglia and astroglia were only temporarily stressed and subsequently survived. In conclusion, oligodendrocytes, then microglia, are the most vulnerable glial cell types in response to hypoxia or hypoglycemia conditions, whereas astrocytes from the same preparations recover.


1994 ◽  
Vol 14 (1) ◽  
pp. 268-276 ◽  
Author(s):  
W Hsu ◽  
T K Kerppola ◽  
P L Chen ◽  
T Curran ◽  
S Chen-Kiang

NF-IL6 and AP-1 family transcription factors are coordinately induced by interleukin-6 (IL-6) in a cell-type-specific manner, suggesting that they mediate IL-6 signals in the nucleus. We show that the basic leucine zipper (bZIP) region of NF-IL6 mediates a direct association with the bZIP regions of Fos and Jun in vitro. This interaction does not depend on the presence of their cognate recognition DNA elements or the posttranslational modification of either partner. NF-IL6 homodimers can bind to both NF-IL6 and AP-1 sites, whereas Fos and Jun cannot bind to most NF-IL6 sites. Cross-family association with Fos or with Jun alters the DNA binding specificity of NF-IL6 and reduced its binding to NF-IL6 sites. NF-IL6 isoforms that differ in the site of translation initiation have distinct transcriptional activities. Activation of a reporter gene linked to the NF-IL6 site by NF-IL6 is repressed by Fos and by Jun in transient transfection assays. Thus, association with AP-1 results in repression of transcription activation by NF-IL6. The repression is NF-IL6 site dependent and may have a role in determining the promoter and cell type specificity in IL-6 signaling.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9799
Author(s):  
Priyanka Upadhyai ◽  
Vishal Singh Guleria ◽  
Prajna Udupa

Primary cilia are non-motile sensory antennae present on most vertebrate cell surfaces. They serve to transduce and integrate diverse external stimuli into functional cellular responses vital for development, differentiation and homeostasis. Ciliary characteristics, such as length, structure and frequency are often tailored to distinct differentiated cell states. Primary cilia are present on a variety of skeletal cell-types and facilitate the assimilation of sensory cues to direct skeletal development and repair. However, there is limited knowledge of ciliary variation in response to the activation of distinct differentiation cascades in different skeletal cell-types. C3H10T1/2, MC3T3-E1 and ATDC5 cells are mesenchymal stem cells, preosteoblast and prechondrocyte cell-lines, respectively. They are commonly employed in numerous in vitro studies, investigating the molecular mechanisms underlying osteoblast and chondrocyte differentiation, skeletal disease and repair. Here we sought to evaluate the primary cilia length and frequencies during osteogenic differentiation in C3H10T1/2 and MC3T3-E1 and chondrogenic differentiation in ATDC5 cells, over a period of 21 days. Our data inform on the presence of stable cilia to orchestrate signaling and dynamic alterations in their features during extended periods of differentiation. Taken together with existing literature these findings reflect the occurrence of not only lineage but cell-type specific variation in ciliary attributes during differentiation. These results extend our current knowledge, shining light on the variabilities in primary cilia features correlated with distinct differentiated cell phenotypes. It may have broader implications in studies using these cell-lines to explore cilia dependent cellular processes and treatment modalities for skeletal disorders centered on cilia modulation.


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