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Fujita T, Seist R, Kao SY, Soares V, Panano L, Khetani RS, Landegger LD, Batts S, Stankovic KM. miR-431 secreted by human vestibular schwannomas increases the mammalian inner ear's vulnerability to noise trauma. Front Neurol 2023; 14:1268359. [PMID: 37885485 PMCID: PMC10598552 DOI: 10.3389/fneur.2023.1268359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 09/20/2023] [Indexed: 10/28/2023] Open
Abstract
Introduction Vestibular schwannoma (VS) is an intracranial tumor that arises on the vestibular branch of cranial nerve VIII and typically presents with sensorineural hearing loss (SNHL). The mechanisms of this SNHL are postulated to involve alterations in the inner ear's microenvironment mediated by the genetic cargo of VS-secreted extracellular vesicles (EVs). We aimed to identify the EV cargo associated with poor hearing and determine whether its delivery caused hearing loss and cochlear damage in a mouse model in vivo. Methods VS tissue was collected from routinely resected tumors of patients with good (VS-GH) or poor (VS-PH) pre-surgical hearing measured via pure-tone average and word recognition scores. Next-generation sequencing was performed on RNA isolated from cultured primary human VS cells and EVs from VS-conditioned media, stratified by patients' hearing ability. microRNA expression levels were compared between VS-PH and VS-GH samples to identify differentially expressed candidates for packaging into a synthetic adeno-associated viral vector (Anc80L65). Viral vectors containing candidate microRNA were infused to the semicircular canals of mice to evaluate the effects on hearing, including after noise exposure. Results Differentially expressed microRNAs included hsa-miR-431-5p (enriched in VS-PH) and hsa-miR-192-5p (enriched in VS-GH). Newborn mice receiving intracochlear injection of viral vectors over-expressing hsa-miR-431-GFP, hsa-miR-192-GFP, or GFP only (control) had similar hearing 6 weeks post-injection. However, after acoustic trauma, the miR-431 group displayed significantly worse hearing, and greater loss of synaptic ribbons per inner hair cell in the acoustically traumatized cochlear region than the control group. Conclusion Our results suggest that miR-431 contributes to VS-associated hearing loss following cochlear stress. Further investigation is needed to determine whether miR-431 is a potential therapeutic target for SNHL.
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Affiliation(s)
- Takeshi Fujita
- Department of Otolaryngology – Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, United States
| | - Richard Seist
- Department of Otolaryngology – Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, United States
| | - Shyan-Yuan Kao
- Department of Otolaryngology – Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, United States
| | - Vitor Soares
- Department of Otolaryngology – Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, United States
| | - Lorena Panano
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, United States
| | - Radhika S. Khetani
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, United States
| | - Lukas D. Landegger
- Department of Otolaryngology – Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, United States
| | - Shelley Batts
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, United States
| | - Konstantina M. Stankovic
- Department of Otolaryngology – Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, United States
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, United States
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, United States
- Wu Tsai Neuroscience Institute, Stanford University, Stanford, CA, United States
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Bieniussa L, Kahraman B, Skornicka J, Schulte A, Voelker J, Jablonka S, Hagen R, Rak K. Pegylated Insulin-Like Growth Factor 1 attenuates Hair Cell Loss and promotes Presynaptic Maintenance of Medial Olivocochlear Cholinergic Fibers in the Cochlea of the Progressive Motor Neuropathy Mouse. Front Neurol 2022; 13:885026. [PMID: 35720065 PMCID: PMC9203726 DOI: 10.3389/fneur.2022.885026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 04/26/2022] [Indexed: 11/13/2022] Open
Abstract
The progressive motor neuropathy (PMN) mouse is a model of an inherited motor neuropathy disease with progressive neurodegeneration. Axon degeneration associates with homozygous mutations of the TBCE gene encoding the tubulin chaperone E protein. TBCE is responsible for the correct dimerization of alpha and beta-tubulin. Strikingly, the PMN mouse also develops a progressive hearing loss after normal hearing onset, characterized by degeneration of the auditory nerve and outer hair cell (OHC) loss. However, the development of this neuronal and cochlear pathology is not fully understood yet. Previous studies with pegylated insulin-like growth factor 1 (peg-IGF-1) treatment in this mouse model have been shown to expand lifespan, weight, muscle strength, and motor coordination. Accordingly, peg-IGF-1 was evaluated for an otoprotective effect. We investigated the effect of peg-IGF-1 on the auditory system by treatment starting at postnatal day 15 (p15). Histological analysis revealed positive effects on OHC synapses of medial olivocochlear (MOC) neuronal fibers and a short-term attenuation of OHC loss. Peg-IGF-1 was able to conditionally restore the disorganization of OHC synapses and maintain the provision of cholinergic acetyltransferase in presynapses. To assess auditory function, frequency-specific auditory brainstem responses and distortion product otoacoustic emissions were recorded in animals on p21 and p28. However, despite the positive effect on MOC fibers and OHC, no restoration of hearing could be achieved. The present work demonstrates that the synaptic pathology of efferent MOC fibers in PMN mice represents a particular form of “efferent auditory neuropathy.” Peg-IGF-1 showed an otoprotective effect by preventing the degeneration of OHCs and efferent synapses. However, enhanced efforts are needed to optimize the treatment to obtain detectable improvements in hearing performances.
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Affiliation(s)
- Linda Bieniussa
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, University Hospital Würzburg, Würzburg, Germany
| | - Baran Kahraman
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, University Hospital Würzburg, Würzburg, Germany
| | - Johannes Skornicka
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, University Hospital Würzburg, Würzburg, Germany
| | - Annemarie Schulte
- Department of Neurology, University Hospital Würzburg, Würzburg, Germany
| | - Johannes Voelker
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, University Hospital Würzburg, Würzburg, Germany
| | - Sibylle Jablonka
- Institute of Clinical Neurobiology, University of Würzburg, Würzburg, Germany
| | - Rudolf Hagen
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, University Hospital Würzburg, Würzburg, Germany
| | - Kristen Rak
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, University Hospital Würzburg, Würzburg, Germany
- *Correspondence: Kristen Rak
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Dong Y, Lyu L, Wen H, Shi B. Brain and Pituitary Transcriptome Analyses Reveal the Differential Regulation of Reproduction-Related LncRNAs and mRNAs in Cynoglossus semilaevis. Front Genet 2021; 12:802953. [PMID: 34956338 PMCID: PMC8696122 DOI: 10.3389/fgene.2021.802953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 11/22/2021] [Indexed: 11/13/2022] Open
Abstract
Long noncoding RNAs (lncRNAs) have been identified to be involved in half-smooth tongue sole (Cynoglossus semilaevis) reproduction. However, studies of their roles in reproduction have focused mainly on the ovary, and their expression patterns and potential roles in the brain and pituitary are unclear. Thus, to explore the mRNAs and lncRNAs that are closely associated with reproduction in the brain and pituitary, we collected tongue sole brain and pituitary tissues at three stages for RNA sequencing (RNA-seq), the 5,135 and 5,630 differentially expressed (DE) mRNAs and 378 and 532 DE lncRNAs were identified in the brain and pituitary, respectively. The RNA-seq results were verified by RT-qPCR. Moreover, enrichment analyses were performed to analyze the functions of DE mRNAs and lncRNAs. Interestingly, their involvement in pathways related to metabolism, signal transduction and endocrine signaling was revealed. LncRNA-target gene interaction networks were constructed based on antisense, cis and trans regulatory mechanisms. Moreover, we constructed competing endogenous RNA (ceRNA) networks. In summary, this study provides mRNA and lncRNA expression profiles in the brain and pituitary to understand the molecular mechanisms regulating tongue sole reproduction.
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Affiliation(s)
- Yani Dong
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.,Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Ocean Unversity of China, Qingdao, China
| | - Likang Lyu
- Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Ocean Unversity of China, Qingdao, China
| | - Haishen Wen
- Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Ocean Unversity of China, Qingdao, China
| | - Bao Shi
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.,Laboratory for Marine Fisheries and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China
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Di Cesare T, Rossi G, Girotto G, Di Nardo W. Benefit of cochlear implantation in a patient with Myhre syndrome. BMJ Case Rep 2021; 14:e243164. [PMID: 34433528 PMCID: PMC8388303 DOI: 10.1136/bcr-2021-243164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/17/2021] [Indexed: 11/04/2022] Open
Abstract
Myhre syndrome is a rare disorder characterised by short stature, skeletal anomalies, facial dysmorphism and hearing loss (HL), resulting from heterozygous mutations of the SMAD4 gene. We describe the benefits of cochlear implant (CI) in a patient with sensorineural HL carrying a mutation (NM_005359.6: c.1498A>G; p.lle500Val) within the SMAD4 gene, detected by whole-exome sequencing. The CI was inserted through the round window despite otospongiotic abnormalities. Pure-tone audiometry improved up to 20 dBHL. Speech perception in noise (Simplified Noise Reduction - SNR +10) increased from 0% pre implantation with hearing aids to 50% post implantation. The postoperative setting of the electrical stimulation limits yielded an asymmetric map, with lower levels for central electrodes and higher levels for lateral ones. Action potential could not be evoked via medial electrodes, suggesting a cochlear nerve dysfunction. Outcomes related to quality of life and cognitive impairment improved. CI was shown to be an effective auditory rehabilitation strategy.
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Affiliation(s)
- Tiziana Di Cesare
- Otorhinolaryngology, Foundation Polyclinic University A. Gemelli IRCCS, Rome, Lazio, Italy
| | - Giorgia Rossi
- Otorhinolaryngology, Foundation Polyclinic University A. Gemelli IRCCS, Rome, Lazio, Italy
| | - Giorgia Girotto
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Friuli-Venezia Giulia, Italy
- Medical Genetics, Institute for Maternal and Child Health, IRCCS, Burlo Garofolo, Trieste, Friuli-Venezia Giulia, Italy
| | - Walter Di Nardo
- Otorhinolaryngology, Foundation Polyclinic University A. Gemelli IRCCS, Rome, Lazio, Italy
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Matboli M, Gadallah SH, Rashed WM, Hasanin AH, Essawy N, Ghanem HM, Eissa S. mRNA-miRNA-lncRNA Regulatory Network in Nonalcoholic Fatty Liver Disease. Int J Mol Sci 2021; 22:ijms22136770. [PMID: 34202571 PMCID: PMC8269036 DOI: 10.3390/ijms22136770] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 12/13/2022] Open
Abstract
AIM we aimed to construct a bioinformatics-based co-regulatory network of mRNAs and non coding RNAs (ncRNAs), which is implicated in the pathogenesis of non-alcoholic fatty liver disease (NAFLD), followed by its validation in a NAFLD animal model. MATERIALS AND METHODS The mRNAs-miRNAs-lncRNAs regulatory network involved in NAFLD was retrieved and constructed utilizing bioinformatics tools. Then, we validated this network using an NAFLD animal model, high sucrose and high fat diet (HSHF)-fed rats. Finally, the expression level of the network players was assessed in the liver tissues using reverse transcriptase real-time polymerase chain reaction. RESULTS in-silico constructed network revealed six mRNAs (YAP1, FOXA2, AMOTL2, TEAD2, SMAD4 and NF2), two miRNAs (miR-650 and miR-1205), and two lncRNAs (RPARP-AS1 and SRD5A3-AS1) that play important roles as a co-regulatory network in NAFLD pathogenesis. Moreover, the expression level of these constructed network-players was significantly different between NAFLD and normal control. Conclusion and future perspectives: this study provides new insight into the molecular mechanism of NAFLD pathogenesis and valuable clues for the potential use of the constructed RNA network in effective diagnostic or management strategies of NAFLD.
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Affiliation(s)
- Marwa Matboli
- Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Ain Shams University, Cairo 11382, Egypt
- Correspondence: (M.M.); (S.E.)
| | - Shaimaa H. Gadallah
- Department of Biochemistry, Faculty of Science, Ain Shams University, Cairo 11382, Egypt; (S.H.G.); (H.M.G.)
| | - Wafaa M. Rashed
- Department of Research, Children’s Cancer Hospital-57357, Cairo 11382, Egypt;
| | - Amany Helmy Hasanin
- Department of Clinical Pharmacology, Faculty of Medicine, Ain Shams University, Cairo 11382, Egypt;
| | - Nada Essawy
- Institut Pasteur, CEDEX 15, 75724 Paris, France;
| | - Hala M. Ghanem
- Department of Biochemistry, Faculty of Science, Ain Shams University, Cairo 11382, Egypt; (S.H.G.); (H.M.G.)
| | - Sanaa Eissa
- Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Ain Shams University, Cairo 11382, Egypt
- Correspondence: (M.M.); (S.E.)
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Du X, Li Q, Yang L, Liu L, Cao Q, Li Q. SMAD4 activates Wnt signaling pathway to inhibit granulosa cell apoptosis. Cell Death Dis 2020; 11:373. [PMID: 32415058 PMCID: PMC7228950 DOI: 10.1038/s41419-020-2578-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 04/26/2020] [Accepted: 04/27/2020] [Indexed: 12/12/2022]
Abstract
The TGF-β and Wnt signaling pathways are interrelated in many cell types and tissues, and control cell functions in coordination. Here, we report that SMAD4, a downstream effector of the TGF-β signaling pathway, induces FZD4, a receptor of the Wnt signaling pathway, establishing a novel route of communication between these two pathways in granulosa cells (GCs). We found that SMAD4 is a strong inducer of FZD4, not only initiating FZD4 transcription but also activating FZD4-dependent Wnt signaling and GC apoptosis. Furthermore, we identified the direct and indirect mechanisms by which SMAD4 promotes expression of FZD4 in GCs. First, SMAD4 functions as a transcription factor to directly bind to the FZD4 promoter region to increase its transcriptional activity. Second, SMAD4 promotes production of SDNOR, a novel lncRNA that acts as a sponge for miR-29c, providing another mean to block miR-29c from degenerating FZD4 mRNA. Overall, our findings not only reveal a new channel of crosstalk between the TGF-β and Wnt signaling pathways, SMAD4–FZD4 axis, but also provide new insights into the regulatory network of GC apoptosis and follicular atresia. These RNA molecules, such as miR-29c and lnc-SDNOR, represent potential targets for treatment of reproductive diseases and improvement of female fertility.
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Affiliation(s)
- Xing Du
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qiqi Li
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Liu Yang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Lu Liu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qiuyu Cao
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qifa Li
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
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Chen K, Liu M, Wu X, Zong L, Jiang H. Targeted next generation sequencing reveals OTOF mutations in auditory neuropathy spectrum disorder. Int J Pediatr Otorhinolaryngol 2018; 115:19-23. [PMID: 30368385 DOI: 10.1016/j.ijporl.2018.09.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 08/05/2018] [Accepted: 09/13/2018] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To study the genetic etiology of auditory neuropathy spectrum disorder (ANSD) in a Chinese family and perform a literature review of OTOF mutations and cochlear implantation (CI). METHODS Sequential targeted next generation sequencing (NGS) and CI was performed for the proband. Further, 50 DNA samples from unrelated families with nonsyndromic deafness were examined for frequency determination. The impact of OTOF mutations on hearing recovery after CI was assessed through the literature survey. RESULTS In the proband, the targeted NGS panel revealed five suspected variants in four genes (OTOF, EYA4, PCDH15, and GIPC3), of which two mutations-c.5098G > C (p.Glu1700Gln) and c.1702C > T (p.Arg568Trp)-in the OTOF gene were found to be correlated with ANSD. The c.5098G > C allele was identified in only one child from the 50 unrelated participants. The proband's hearing and speech abilities were restored 2 years after the surgery. Most ANSD patients (90.9%; 30/33) with OTOF mutations have acceptable surgical outcomes, as indicated by existing reports. CONCLUSIONS Our results support the feasibility of CI for patients with ANSD and OTOF mutations, and this hypothesis was supported by the review of existing data. A larger number of cases studies is required to determine possible modifies on the prognosis of surgery.
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Affiliation(s)
- Kaitian Chen
- Department of Otorhinolaryngology, The First Affiliated Hospital, Sun Yat-sen University and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, 510080, PR China
| | - Min Liu
- Department of Otorhinolaryngology, The First Affiliated Hospital, Sun Yat-sen University and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, 510080, PR China
| | - Xuan Wu
- Department of Otorhinolaryngology, The First Affiliated Hospital, Sun Yat-sen University and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, 510080, PR China
| | - Ling Zong
- Department of Otorhinolaryngology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510260, PR China
| | - Hongyan Jiang
- Department of Otorhinolaryngology, Hainan General Hospital, Haikou, 570311, PR China.
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Qin G, Wang GZ, Guo DD, Bai RX, Wang M, Du SY. Deletion of Smad4 reduces hepatic inflammation and fibrogenesis during nonalcoholic steatohepatitis progression. J Dig Dis 2018; 19:301-313. [PMID: 29696816 DOI: 10.1111/1751-2980.12599] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Revised: 03/12/2018] [Accepted: 04/19/2018] [Indexed: 01/18/2023]
Abstract
OBJECTIVE To explore the effects of mothers against decapentaplegic homolog family member 4 (Smad4) deletion on inflammation and fibrogenesis in nonalcoholic steatohepatitis (NASH). METHODS Biopsied liver samples from NASH patients and normal liver tissue samples from patients who had received liver resection for trauma were collected. Smad4Co/Co and wild-type (WT) mice were used to construct the NASH model using a high-fat diet (HFD) or methionine- and choline-deficient diet (MCD). HE staining and TUNEL assay were used to observe the pathological changes and cell apoptosis, respectively. Quantitative real-time polymerase chain reaction was used to detect the expression of inflammatory, fibrogenesis and apoptosis-related genes, and immunohistochemistry to determine the protein expression of SMAD4, MCP-1 and α-SMA. RESULTS SMAD4 protein expression significantly increased in NASH patients than in the control group. Compared with WT mice, HFD- and MCD-fed Smad4Co/Co mice showed decreased hepatic steatosis, inflammation, liver cell apoptosis and nonalcoholic fatty liver activity score, reduced plasma glucose, triglyceride, free fatty acids, alanine aminotransferase and aspartate aminotransferase levels but increased adiponectin. Moreover, Smad4Co/Co decreased the expression of inflammatory markers (TNF-α, MCP-1, IFN-γ), fibrogenetic markers (COL1A1, α-SMA and TGF-β1), lipogenic (Srebp1c, Fas and Acc) and proapoptotic genes (Bax and caspase-3), but increased the expression of β-oxidation (Ppar-α, Cpt1 and Aco) and antiapoptotic genes (Bcl-2). CONCLUSION Smad4 deletion may inhibit lipogenesis, stimulate β-oxidation, improve lipid metabolism and liver function, alleviate inflammation and fibrosis, and reduce cell apoptosis in NASH.
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Affiliation(s)
- Geng Qin
- Department of Gastroenterology, China-Japan Friendship Hospital, Beijing, China
| | - Guo Zhen Wang
- Department of Clinical Laboratory, China-Japan Friendship Hospital, Beijing, China
| | - Dan Dan Guo
- Department of Ultrasonography, China-Japan Friendship Hospital, Beijing, China
| | - Ru Xue Bai
- Department of Gastroenterology, China-Japan Friendship Hospital, Beijing, China
| | - Miao Wang
- Department of Gastroenterology, China-Japan Friendship Hospital, Beijing, China
| | - Shi Yu Du
- Department of Gastroenterology, China-Japan Friendship Hospital, Beijing, China
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Auditory Neuropathy after Damage to Cochlear Spiral Ganglion Neurons in Mice Resulting from Conditional Expression of Diphtheria Toxin Receptors. Sci Rep 2017; 7:6409. [PMID: 28743950 PMCID: PMC5527113 DOI: 10.1038/s41598-017-06600-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 06/15/2017] [Indexed: 01/08/2023] Open
Abstract
Auditory neuropathy (AN) is a hearing disorder characterized by normal cochlear amplification to sound but poor temporal processing and auditory perception in noisy backgrounds. These deficits likely result from impairments in auditory neural synchrony; such dyssynchrony of the neural responses has been linked to demyelination of auditory nerve fibers. However, no appropriate animal models are currently available that mimic this pathology. In this study, Cre-inducible diphtheria toxin receptor (iDTR+/+) mice were cross-mated with mice containing Cre (Bhlhb5-Cre+/−) specific to spiral ganglion neurons (SGNs). In double-positive offspring mice, the injection of diphtheria toxin (DT) led to a 30–40% rate of death for SGNs, but no hair cell damage. Demyelination types of pathologies were observed around the surviving SGNs and their fibers, many of which were distorted in shape. Correspondingly, a significant reduction in response synchrony to amplitude modulation was observed in this group of animals compared to the controls, which had a Cre− genotype. Taken together, our results suggest that SGN damage following the injection of DT in mice with Bhlhb5-Cre+/− and iDTR+/− is likely to be a good AN model of demyelination.
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