scholarly journals LncRNA-DRSGN (Down-Regulated in Spiral Ganglion Neurons) Competes with miR-27a for Binding to FAM172A, Supervises SGN Degeneration and ER (Endoplasmic Reticulum) Stress-Autophagy in CHARGE Syndrome

Author(s):  
Xian-Bao Cao ◽  
Bi-Zhang Lu ◽  
Jia-Hong Pei ◽  
Cun Feng ◽  
Yan-Fei Guan ◽  
...  

Abstract Background: Hearing loss is one of the most common disabilities in the world and brings a heavy burden to society. The current model is not stable enough, and it has caused serious model interference to clarify the pathogenesis of CHARGE syndrome. Methods: The knockout mouse model of FAM172A gene was constructed, and sits phenotype was identified. Besides, the next-genesequencing experiments of noncoding RNAs were performed utilizing the primary SGNs of model mice. The biofunctions of FAM172A in the relationships between ER (Endoplasmic reticulum) stress, autophagy, and intracellular calcium flux were investigated. Moreover, the above role associated with the competitive combination among LncRNA-DRSGN, miR-27a, and FAM172A were studied in the progression of SGN degeneration and autophagy in the model of CHARGE syndrome. Results: FAM172A(-/-) exhibited abnormal hearing, growth retardation, abnormal eye development, and dysgnosia. It was in line with the phenotype of CHARGE syndrome. Moreover, there was degeneration of SGNs in FAM172A(-/-) mice, and the differential expression of noncoding RNAs in primary SGNs were found and identified, including miR-27a and LncRNA-DRSGN. LncRNA-DRSGN regulated miR-27a as a ceRNA, and miR-27a inhibited FAM172A expression, LncRNA-DRSGN competed with miR-27a for binding to FAM172A, which participated in the regulation of ER stress-related calcium flux. LncRNA-DRSGN regulated the autophagy process of neurons by competing with miR-27a for binding to FAM172A. Conclusion: LncRNA-DRSGN competed with miR-27a for binding to FAM172A, participated in regulating ER stress-related calcium flux, then affected neuron degeneration and autophagy process of SGNs in the model of CHARGE syndrome.

2019 ◽  
Vol 39 (2) ◽  
Author(s):  
Yaqin Tu ◽  
Guorun Fan ◽  
Haiying Sun ◽  
Xiong Cai ◽  
Wen Kong

Abstract Aminoglycoside antibiotics-induced hearing loss is a common sensorineural impairment. Spiral ganglion neurons (SGNs) are first-order neurons of the auditory pathway and are critical for the maintenance of normal hearing. In the present study, we investigated the time-course of morphological changes and the degeneration process of spiral ganglion cells (SGCs) following chronic kanamycin-induced deafness and determined whether the endoplasmic reticulum (ER) stress was involved in the degeneration of SGNs. We detected density changes in SGCs and the expressions of Bip, inositol requirement 1 (IRE1)α, activating transcription factor-6α, p-PERK, p-eIF2α, CHOP, and caspase-12 at each time point after kanamycin treatment. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining was also performed. The number of SGC deletions reached ∼50% at the 70th day after kanamycin administration and the ER of most SGCs were dilated. The expression of p-PERK, p-eIF2α, p-IRE1α, Bip, caspase-12, and Chop was significantly unregulated after kanamycin treatment. The number of SGCs that were positive for both TUNEL and caspase-12 increased from day 7 to 28. Taken together, these data demonstrate that ER stress was involved in kanamycin-induced apoptosis of SGNs. Kanamycin-induced SGN apoptosis is mediated, at least in part, by ER stress-induced upregulation of CHOP and caspase-12.


2019 ◽  
Vol 19 (5) ◽  
pp. 665-675 ◽  
Author(s):  
Wenjiao Shi ◽  
Zhixin Guo ◽  
Ruixia Yuan

Background and Objective: This study investigated whether rapamycin has a protective effect on the testis of diabetic rats by regulating autophagy, endoplasmic reticulum stress, and oxidative stress. Methods: Thirty male Sprague-Dawley rats were randomly divided into three groups: control, diabetic, and diabetic treated with rapamycin, which received gavage of rapamycin (2mg.kg-1.d-1) after induction of diabetes. Diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ, 65mg.Kg-1). All rats were sacrificed at the termination after 8 weeks of rapamycin treatment. The testicular pathological changes were determined by hematoxylin and eosin staining. The protein or mRNA expression of autophagy-related proteins (Beclin1, microtubule-associated protein light chain 3 (LC3), p62), ER stress marked proteins (CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP), caspase-12), oxidative stress-related proteins (p22phox, nuclear factor erythroid2-related factor 2 (Nrf2)) and apoptosis-related proteins (Bax, B cell lymphoma-2 (Bcl-2)) were assayed by western blot or real-time fluorescence quantitative PCR. Results: There were significant pathological changes in the testes of diabetic rats. The expression of Beclin1, LC3, Nrf2, Bcl-2 were significantly decreased and p62, CHOP, caspase12, p22phox, and Bax were notably increased in the testis of diabetic rats (P <0.05). However, rapamycin treatment for 8 weeks significantly reversed the above changes in the testis of diabetic rats (P <0.05). Conclusion: Rapamycin appears to produce a protective effect on the testes of diabetic rats by inducing the expression of autophagy and inhibiting the expression of ER-stress, oxidative stress, and apoptosis.


2021 ◽  
Vol 22 (9) ◽  
pp. 4538
Author(s):  
Helena Kratochvílová ◽  
Miloš Mráz ◽  
Barbora J. Kasperová ◽  
Daniel Hlaváček ◽  
Jakub Mahrík ◽  
...  

The aim of our study was to analyze mitochondrial and endoplasmic reticulum (ER) gene expression profiles in subcutaneous (SAT) and epicardial (EAT) adipose tissue, skeletal muscle, and myocardium in patients with and without CAD undergoing elective cardiac surgery. Thirty-eight patients, 27 with (CAD group) and 11 without CAD (noCAD group), undergoing coronary artery bypass grafting and/or valvular surgery were included in the study. EAT, SAT, intercostal skeletal muscle, and right atrium tissue and blood samples were collected at the start and end of surgery; mRNA expression of selected mitochondrial and ER stress genes was assessed using qRT-PCR. The presence of CAD was associated with decreased mRNA expression of most of the investigated mitochondrial respiratory chain genes in EAT, while no such changes were seen in SAT or other tissues. In contrast, the expression of ER stress genes did not differ between the CAD and noCAD groups in almost any tissue. Cardiac surgery further augmented mitochondrial dysfunction in EAT. In our study, CAD was associated with decreased expression of mitochondrial, but not endoplasmic reticulum stress genes in EAT. These changes may contribute to the acceleration of coronary atherosclerosis.


2021 ◽  
pp. 019459982110089
Author(s):  
Rafael da Costa Monsanto ◽  
Renata Malimpensa Knoll ◽  
Norma de Oliveira Penido ◽  
Grace Song ◽  
Felipe Santos ◽  
...  

Objective To perform an otopathologic analysis of temporal bones (TBs) with CHARGE syndrome. Study Design Otopathologic study of human TB specimens. Setting Otopathology laboratories. Methods From the otopathology laboratories at the University of Minnesota and Massachusetts Eye and Ear Infirmary, we selected TBs from donors with CHARGE syndrome. These TBs were serially sectioned at a thickness of 20 µm, and every 10th section was stained with hematoxylin and eosin. We performed otopathologic analyses of the external ear, middle ear (middle ear cleft, mucosal lining, ossicles, mastoid, and facial nerve), and inner ear (cochlea, vestibule, internal auditory canal, and cochlear and vestibular nerves). The gathered data were statistically analyzed. Results Our study included 12 TBs from 6 donors. We found a high prevalence of abnormalities affecting the ears. The most frequent findings were stapes malformation (100%), aberrant course of the facial nerve (100%) with narrow facial recess (50%), sclerotic and hypodeveloped mastoids (50%), cochlear (100%) and vestibular (83.3%) hypoplasia with aplasia of the semicircular canals, hypoplasia and aplasia of the cochlear (66.6%) and vestibular (91.6%) nerves, and narrowing of the bony canal of the cochlear nerve (66.6%). The number of spiral ganglion and Scarpa’s ganglion neurons were decreased in all specimens (versus normative data). Conclusions In our study, CHARGE syndrome was associated with multiple TB abnormalities that may severely affect audiovestibular function and rehabilitation.


2021 ◽  
Author(s):  
Viorica Liebe Lastun ◽  
Matthew Freeman

In metazoans, the architecture of the endoplasmic reticulum (ER) differs between cell types, and undergoes major changes through the cell cycle and according to physiological needs. Although much is known about how the different ER morphologies are generated and maintained, especially the ER tubules, how context dependent changes in ER shape and distribution are regulated and the factors involved are less characterized. Here, we show that RHBDL4, an ER-resident rhomboid protease, modulates the shape and distribution of the ER, especially under conditions that require rapid changes in the ER sheet distribution, including ER stress. RHBDL4 interacts with CLIMP-63, a protein involved in ER sheet stabilisation, and with the cytoskeleton. Mice lacking RHBDL4 are sensitive to ER stress and develop liver steatosis, a phenotype associated with unresolved ER stress. Our data introduce a new physiological role of RHBDL4 and also imply that this function does not require its enzymatic activity.


mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Oanh H. Pham ◽  
Bokyung Lee ◽  
Jasmine Labuda ◽  
A. Marijke Keestra-Gounder ◽  
Mariana X. Byndloss ◽  
...  

ABSTRACT The inflammatory response to Chlamydia infection is likely to be multifactorial and involve a variety of ligand-dependent and -independent recognition pathways. We previously reported the presence of NOD1/NOD2-dependent endoplasmic reticulum (ER) stress-induced inflammation during Chlamydia muridarum infection in vitro, but the relevance of this finding to an in vivo context is unclear. Here, we examined the ER stress response to in vivo Chlamydia infection. The induction of interleukin 6 (IL-6) production after systemic Chlamydia infection correlated with expression of ER stress response genes. Furthermore, when tauroursodeoxycholate (TUDCA) was used to inhibit the ER stress response, an increased bacterial burden was detected, suggesting that ER stress-driven inflammation can contribute to systemic bacterial clearance. Mice lacking both NOD1 and NOD2 or RIP2 exhibited slightly higher systemic bacterial burdens after infection with Chlamydia. Overall, these data suggest a model where RIP2 and NOD1/NOD2 proteins link ER stress responses with the induction of Chlamydia-specific inflammatory responses. IMPORTANCE Understanding the initiation of the inflammatory response during Chlamydia infection is of public health importance given the impact of this disease on young women in the United States. Many young women are chronically infected with Chlamydia but are asymptomatic and therefore do not seek treatment, leaving them at risk of long-term reproductive harm due to inflammation in response to infection. Our manuscript explores the role of the endoplasmic reticulum stress response pathway initiated by an innate receptor in the development of this inflammation.


2019 ◽  
Vol 54 (5) ◽  
pp. 465-471 ◽  
Author(s):  
Sheng Wang ◽  
Jiajie Luan ◽  
Xiongwen Lv

ICR mice received ethanol (5 g/kg) by intragastric administration, showing an increase in hepatosomatic index and ALT. These effects were accompanied by increased expression of ER stress-related proteins and exosomal miR-122, PBA intervention can attenuate these changes induced by ethanol provides a potential therapy strategy for acute alcoholic liver injury.


2018 ◽  
Vol 120 (2) ◽  
pp. 509-524 ◽  
Author(s):  
John N. Barrett ◽  
Samantha Rincon ◽  
Jayanti Singh ◽  
Cristina Matthewman ◽  
Julio Pasos ◽  
...  

Inner ear spiral ganglion neurons were cultured from day 4 postnatal mice and loaded with a fluorescent Ca2+ indicator (fluo-4, -5F, or -5N). Pulses of infrared radiation (IR; 1,863 nm, 200 µs, 200–250 Hz for 2–5 s, delivered via an optical fiber) produced a rapid, transient temperature increase of 6–12°C (above a baseline of 24–30°C). These IR pulse trains evoked transient increases in both nuclear and cytosolic Ca2+ concentration ([Ca2+]) of 0.20–1.4 µM, with a simultaneous reduction of [Ca2+] in regions containing endoplasmic reticulum (ER). IR-induced increases in cytosolic [Ca2+] continued in medium containing no added Ca2+ (±Ca2+ buffers) and low [Na+], indicating that the [Ca2+] increase was mediated by release from intracellular stores. Consistent with this hypothesis, the IR-induced [Ca2+] response was prolonged and eventually blocked by inhibition of ER Ca2+-ATPase with cyclopiazonic acid, and was also inhibited by a high concentration of ryanodine and by inhibitors of inositol (1,4,5)-trisphosphate (IP3)-mediated Ca2+ release (xestospongin C and 2-aminoethoxydiphenyl borate). The thermal sensitivity of the response suggested involvement of warmth-sensitive transient receptor potential (TRP) channels. The IR-induced [Ca2+] increase was inhibited by TRPV4 inhibitors (HC-067047 and GSK-2193874), and immunostaining of spiral ganglion cultures demonstrated the presence of TRPV4 and TRPM2 that colocalized with ER marker GRP78. These results suggest that the temperature sensitivity of IR-induced [Ca2+] elevations is conferred by TRP channels on ER membranes, which facilitate Ca2+ efflux into the cytosol and thereby contribute to Ca2+-induced Ca2+-release via IP3 and ryanodine receptors. NEW & NOTEWORTHY Infrared radiation-induced photothermal effects release Ca2+ from the endoplasmic reticulum of primary spiral ganglion neurons. This Ca2+ release is mediated by activation of transient receptor potential (TRPV4) channels and involves amplification by Ca2+-induced Ca2+-release. The neurons immunostained for warmth-sensitive channels, TRPV4 and TRPM2, which colocalize with endoplasmic reticulum. Pulsed infrared radiation provides a novel experimental tool for releasing intracellular Ca2+, studying Ca2+ regulatory mechanisms, and influencing neuronal excitability.


2018 ◽  
Vol 40 (2) ◽  
pp. 175-188 ◽  
Author(s):  
Michael J. Hylin ◽  
Ryan C. Holden ◽  
Aidan C. Smith ◽  
Aric F. Logsdon ◽  
Rabia Qaiser ◽  
...  

The leading cause of death in the juvenile population is trauma, and in particular neurotrauma. The juvenile brain response to neurotrauma is not completely understood. Endoplasmic reticulum (ER) stress has been shown to contribute to injury expansion and behavioral deficits in adult rodents and furthermore has been seen in adult postmortem human brains diagnosed with chronic traumatic encephalopathy. Whether endoplasmic reticulum stress is increased in juveniles with traumatic brain injury (TBI) is poorly delineated. We investigated this important topic using a juvenile rat controlled cortical impact (CCI) model. We proposed that ER stress would be significantly increased in juvenile rats following TBI and that this would correlate with behavioral deficits using a juvenile rat model. A juvenile rat (postnatal day 28) CCI model was used. Binding immunoglobulin protein (BiP) and C/EBP homologous protein (CHOP) were measured at 4 h in the ipsilateral pericontusion cortex. Hypoxia-inducible factor (HIF)-1α was measured at 48 h and tau kinase measured at 1 week and 30 days. At 4 h following injury, BiP and CHOP (markers of ER stress) were significantly elevated in rats exposed to TBI. We also found that HIF-1α was significantly upregulated 48 h following TBI showing delayed hypoxia. The early ER stress activation was additionally asso­ciated with the activation of a known tau kinase, glycogen synthase kinase-3β (GSK-3β), by 1 week. Tau oligomers measured by R23 were significantly increased by 30 days following TBI. The biochemical changes following TBI were associated with increased impulsive-like or anti-anxiety behavior measured with the elevated plus maze, deficits in short-term memory measured with novel object recognition, and deficits in spatial memory measured with the Morris water maze in juvenile rats exposed to TBI. These results show that ER stress was increased early in juvenile rats exposed to TBI, that these rats developed tau oligomers over the course of 30 days, and that they had significant short-term and spatial memory deficits following injury.


2016 ◽  
Vol 28 (2) ◽  
pp. 187
Author(s):  
C. Ahn ◽  
D. Lee ◽  
K. P. Kim ◽  
M. H. Lee ◽  
E.-B. Jeung

Endoplasmic reticulum (ER) regulates calcium ion concentration as a reservoir in the cell. ER stress is a cellular stress response related to the endoplasmic reticulum. At the initial stage of ER stress, ER tries to restore normal function by halting protein translation, degrading misfolded proteins, and increasing production of chaperones involved in protein folding. If ER fails to restore ER stress, ER stress can lead cells to apoptosis. To study the signaling between ER stress and calcium channels under ER-stressed circumstances, we designed a hypoxia-induced diabetic model. Nine-week-old male mice were chosen, maintained under hypoxic condition under 10% O2, 5% CO2 for 10 days, and the expression of ER stress markers and calcium channel gene expression were examined by real-time PCR. By maintaining hypoxic condition, the mice showed high glucose levels. Under this diabetic condition, in pancreatic beta cells, ER stress markers were elevated. This tendency showed an increase in calbindin-D9k KO mice. Chaperones such as calreticulin and calnexin were decreased, but in calbindin-D9k KO mice chaperone calnexin was not decreased. Interestingly, the calbindin-D9k KO normoxia mice showed increased glucose level compared with wild-type normoxia mice. Also, calnexin expression of pancreas was decreased in calbindin-D9k KO normoxia mice. This result indicates that pancreas cells were under endoplasmic reticulum stress. Taken together, calbindin may play an important role in endoplasmic reticulum stress in pancreas. This work was supported by the National Research Foundation of Korea (NRF) grant of Korean government (MEST) (No. 2013-010514).


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