RESUMEN
Over-production of reactive oxygen species (ROS) in the inner ear can be triggered by a variety of pathological events identified in animal models after traumatic noise exposure. Our previous research found that inhibition of the AMP-activated protein kinase alpha subunit (AMPKα) protects against noise-induced cochlear hair cell loss and hearing loss by reducing ROS accumulation. However, the molecular pathway through which AMPKα exerts its antioxidative effect is still unclear. In this study, we have investigated a potential target of AMPKα and ROS, cystic fibrosis transmembrane conductance regulator (CFTR), and the protective effect against noise-induced hair cell loss of an FDA-approved CFTR potentiator, ivacaftor, in FVB/NJ mice, mouse explant cultures, and HEI-OC1 cells. We found that noise exposure increases phosphorylation of CFTR at serine 737 (p-CFTR, S737), which reduces wildtype CFTR function, resulting in oxidative stress in cochlear sensory hair cells. Pretreatment with a single dose of ivacaftor maintains CFTR function by preventing noise-increased p-CFTR (S737). Furthermore, ivacaftor treatment increases nuclear factor E2-related factor 2 (Nrf2) expression, diminishes ROS formation, and attenuates noise-induced hair cell loss and hearing loss. Additionally, inhibition of noise-induced AMPKα activation by compound C also diminishes p-CFTR (S737) expression. In line with these in-vivo results, administration of hydrogen peroxide to cochlear explants or HEI-OC1 cells increases p-CFTR (S737) expression and induces sensory hair cell or HEI-OC1 cell damage, while application of ivacaftor halts these effects. Although ivacaftor increases Nrf2 expression and reduces ROS accumulation, cotreatment with ML385, an Nrf2 inhibitor, abolishes the protective effects of ivacaftor against hydrogen-peroxide-induced HEI-OC1 cell death. Our results indicate that noise-induced sensory hair cell damage is associated with p-CFTR. Ivacaftor has potential for treatment of noise-induced hearing loss by maintaining CFTR function and increasing Nrf2 expression for support of redox homeostasis in sensory hair cells.
Asunto(s)
Regulador de Conductancia de Transmembrana de Fibrosis Quística , Factor 2 Relacionado con NF-E2 , Animales , Ratones , Especies Reactivas de Oxígeno , Estrés Oxidativo , Células Ciliadas Auditivas , Proteínas Quinasas Activadas por AMP , Alopecia , Anticuerpos , Oxidación-ReducciónRESUMEN
Introduction: Noise-induced calcium overload in sensory hair cells has been well documented as an early step in the pathogenesis of noise-induced hearing loss (NIHL). Alterations in cellular calcium homeostasis mediate a series of cellular events, including activation of calcium-dependent protein kinases and phosphatases. Using cell-membrane- and blood-brain-barrier-permeable calpain-1 (µ-calpain) and calpain-2 (m-calpain) inhibitor MDL-28170, we tested the involvement of calpains, a family of calcium-dependent cysteine proteases, and the potential of MDL-28170 in preventing NIHL. Methods: CBA/J mice at the age of 12 weeks were exposed to broadband noise with a frequency spectrum from 2-20 kHz for 2 h at 101 dB sound pressure level to induce permanent hearing loss as measured by auditory brainstem response and distortion product otoacoustic emissions. Morphological damage was assessed by quantification of remaining sensory hair cells and inner hair cell synapses 2 weeks after the exposure. Results: MDL-28170 treatment by intraperitoneal injection significantly attenuated noise-induced functional deficits and cochlear pathologies. MDL-28170 treatment also prevented noise-induced cleavage of alpha-fodrin, a substrate for calpain-1. Furthermore, MDL-28170 treatment prevented reduction of PI3K/Akt signaling after exposure to noise and upregulated p85α and p-Akt (S473) in outer hair cells. Discussion: These results indicate that noise-induced calpain activation negatively regulates PI3K/Akt downstream signaling, and that prevention of NIHL by treatment with MDL-28170 is associated with upregulation of PI3K/Akt survival signaling pathways.
RESUMEN
BACKGROUND: The Ca2+/calmodulin-dependent protein kinase kinases (CaMKKs) are serine/threonine-directed protein kinases that are activated following increases in intracellular calcium, playing a critical role in neuronal signaling. Inner-ear-trauma-induced calcium overload in sensory hair cells has been well documented in the pathogenesis of traumatic noise-induced hair cell death and hearing loss, but there are no established pharmaceutical therapies available due to a lack of specific therapeutic targets. In this study, we investigated the activation of CaMKKß in the inner ear after traumatic noise exposure and assessed the prevention of noise-induced hearing loss (NIHL) with RNA silencing. RESULTS: Treatment with short hairpin RNA of CaMKKß (shCaMKKß) via adeno-associated virus transduction significantly knocked down CaMKKß expression in the inner ear. Knockdown of CaMKKß significantly attenuated noise-induced hair cell loss and hearing loss (NIHL). Additionally, pretreatment with naked CaMKKß small interfering RNA (siCaMKKß) attenuated noise-induced losses of inner hair cell synapses and OHCs and NIHL. Furthermore, traumatic noise exposure activates CaMKKß in OHCs as demonstrated by immunolabeling for p-CaMKI. CaMKKß mRNA assessed by fluorescence in-situ hybridization and immunolabeling for CaMKKß in OHCs also increased after the exposure. Finally, pretreatment with siCaMKKß diminished noise-induced activation of AMPKα in OHCs. CONCLUSIONS: These findings demonstrate that traumatic-noise-induced OHC loss and hearing loss occur primarily via activation of CaMKKß. Targeting CaMKKß is a key strategy for prevention of noise-induced hearing loss. Furthermore, our data suggest that noise-induced activation of AMPKα in OHCs occurs via the CaMKKß pathway.
Asunto(s)
Sordera , Pérdida Auditiva Provocada por Ruido , Proteínas Quinasas Activadas por AMP/metabolismo , Calcio/metabolismo , Quinasa de la Proteína Quinasa Dependiente de Calcio-Calmodulina/genética , Quinasa de la Proteína Quinasa Dependiente de Calcio-Calmodulina/metabolismo , Muerte Celular , Sordera/metabolismo , Cabello/metabolismo , Células Ciliadas Auditivas Externas/metabolismo , Células Ciliadas Auditivas Externas/patología , Pérdida Auditiva Provocada por Ruido/etiología , Pérdida Auditiva Provocada por Ruido/patología , Pérdida Auditiva Provocada por Ruido/prevención & control , Humanos , Proteínas Serina-Treonina Quinasas , ARN Interferente Pequeño/metabolismoRESUMEN
Attenuation of noise-induced hair cell loss and noise-induced hearing loss (NIHL) by treatment with FK506 (tacrolimus), a calcineurin (CaN/PP2B) inhibitor used clinically as an immunosuppressant, has been previously reported, but the downstream mechanisms of FK506-attenuated NIHL remain unknown. Here we showed that CaN immunolabeling in outer hair cells (OHCs) and nuclear factor of activated T-cells isoform c4 (NFATc4/NFAT3) in OHC nuclei are significantly increased after moderate noise exposure in adult CBA/J mice. Consequently, treatment with FK506 significantly reduces moderate-noise-induced loss of OHCs and NIHL. Furthermore, induction of reactive oxygen species (ROS) by moderate noise was significantly diminished by treatment with FK506. In agreement with our previous finding that autophagy marker microtubule-associated protein light chain 3B (LC3B) does not change in OHCs under conditions of moderate-noise-induced permanent threshold shifts, treatment with FK506 increases LC3B immunolabeling in OHCs after exposure to moderate noise. Additionally, prevention of NIHL by treatment with FK506 was partially abolished by pretreatment with LC3B small interfering RNA. Taken together, these results indicate that attenuation of moderate-noise-induced OHC loss and hearing loss by FK506 treatment occurs not only via inhibition of CaN activity but also through inhibition of ROS and activation of autophagy.
RESUMEN
Hepatocellular carcinoma (HCC) is typically fatal, and patients with hepatocellular carcinoma are usually diagnosed at the late stages. Although the treatments for HCC have been rapidly advancing, novel targets for HCC are still desperately needed, especially for targeted therapies. Here, we identified an enriched long non-coding RNA, AC006262.5, associated with HCC, that promoted the proliferation, migration, and invasiveness of HCC cells, both in vitro and in vivo. In addition, our results revealed that AC006262.5 bound to and regulated miR-7855-5p, a tumor-suppressive miRNA, in HCC. Moreover, our data show that AC006262.5 regulates the expression of BPY2C via miR-7855-5p. Finally, we found that AC006262.5 and miR-7855-5p formed a regulatory loop. Upregulation of AC006262.5 resulted in decreased expression of miR-7855-5p, and downregulation of miR-7855-5p further facilitated the expression of AC006262.5. Our work provides novel targets for HCC diagnosis and treatment, and sheds light on the lncRNA-miRNA regulatory nexus that controls the pathology of HCC.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Carcinoma Hepatocelular/patología , Movimiento Celular , Regulación Neoplásica de la Expresión Génica , MicroARNs/genética , Proteínas/metabolismo , ARN Largo no Codificante/genética , Animales , Apoptosis , Biomarcadores de Tumor/genética , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Proliferación Celular , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Proteínas/genética , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
We describe the convergent synthesis of a 5-O-ß-D-ribofuranosyl-based apramycin derivative (apralog) that displays significantly improved antibacterial activity over the parent apramycin against wild-type ESKAPE pathogens. In addition, the new apralog retains excellent antibacterial activity in the presence of the only aminoglycoside modifying enzyme (AAC(3)-IV) acting on the parent, without incurring susceptibility to the APH(3') mechanism that disables other 5-O-ß-D-ribofuranosyl 2-deoxystreptamine type aminoglycosides by phosphorylation at the ribose 5-position. Consistent with this antibacterial activity, the new apralog has excellent 30â nM activity (IC50 ) for the inhibition of protein synthesis by the bacterial ribosome in a cell-free translation assay, while retaining the excellent across-the-board selectivity of the parent for inhibition of bacterial over eukaryotic ribosomes. Overall, these characteristics translate into excellent inâ vivo efficacy against E. coli in a mouse thigh infection model and reduced ototoxicity vis à vis the parent in mouse cochlear explants.
Asunto(s)
Antibacterianos/farmacología , Cóclea/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Nebramicina/análogos & derivados , Animales , Antibacterianos/síntesis química , Antibacterianos/química , Conformación de Carbohidratos , Cóclea/metabolismo , Ratones , Pruebas de Sensibilidad Microbiana , Nebramicina/síntesis química , Nebramicina/química , Nebramicina/farmacologíaRESUMEN
Recent studies have demonstrated that various long non-coding RNAs (lncRNAs) participate in the gastric cancer (GC) development and metastasis. Some lncRNAs exert their regulatory function by interacting with microRNAs. Here we identified a novel lncRNA RP11-81H3.2 that was highly expressed in the GC tissue and cell lines. RP11-81H3.2 knockdown significantly inhibited the proliferation, migration, and invasion of GC cells. Mechanistically, we demonstrated that RP11-81H3.2 directly interacted with miR-339 while miR-339 regulated the HNRNPA1 expression by targeting HRRNPA1 3'-UTR. RP11-81H3.2-miR-339-HNRNPA1 interaction network regulated the GC cell proliferation, migration, and invasion. Moreover, our results confirmed that RP11-81H3.2 knockdown suppressed the tumor growth of GC in a xenograft model in vivo. In summary, the results suggest that RP11-81H3.2 functions as an oncogene in GC and could be utilized as a promising diagnosis and therapeutic marker for GC treatment.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Regulación Neoplásica de la Expresión Génica , Ribonucleoproteína Nuclear Heterogénea A1/metabolismo , MicroARNs/genética , ARN Largo no Codificante/genética , Neoplasias Gástricas/patología , Animales , Apoptosis , Biomarcadores de Tumor/genética , Movimiento Celular , Proliferación Celular , Femenino , Ribonucleoproteína Nuclear Heterogénea A1/genética , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , MicroARNs/metabolismo , Persona de Mediana Edad , Pronóstico , Dominios y Motivos de Interacción de Proteínas , ARN Largo no Codificante/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Tasa de Supervivencia , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Apramycin is a structurally unique member of the 2-deoxystreptamine class of aminoglycoside antibiotics characterized by a monosubstituted 2-deoxystreptamine ring that carries an unusual bicyclic eight-carbon dialdose moiety. Because of its unusual structure, apramycin is not susceptible to the most prevalent mechanisms of aminoglycoside resistance including the aminoglycoside-modifying enzymes and the ribosomal methyltransferases whose widespread presence severely compromises all aminoglycosides in current clinical practice. These attributes coupled with minimal ototoxocity in animal models combine to make apramycin an excellent starting point for the development of next-generation aminoglycoside antibiotics for the treatment of multidrug-resistant bacterial infections, particularly the ESKAPE pathogens. With this in mind, we describe the design, synthesis, and evaluation of three series of apramycin derivatives, all functionalized at the 5-position, with the goals of increasing the antibacterial potency without sacrificing selectivity between bacterial and eukaryotic ribosomes and of overcoming the rare aminoglycoside acetyltransferase (3)-IV class of aminoglycoside-modifying enzymes that constitutes the only documented mechanism of antimicrobial resistance to apramycin. We show that several apramycin-5-O-ß-d-ribofuranosides, 5-O-ß-d-eryrthofuranosides, and even simple 5-O-aminoalkyl ethers are effective in this respect through the use of cell-free translation assays with wild-type bacterial and humanized bacterial ribosomes and of extensive antibacterial assays with wild-type and resistant Gram negative bacteria carrying either single or multiple resistance determinants. Ex vivo studies with mouse cochlear explants confirm the low levels of ototoxicity predicted on the basis of selectivity at the target level, while the mouse thigh infection model was used to demonstrate the superiority of an apramycin-5-O-glycoside in reducing the bacterial burden in vivo.
Asunto(s)
Aminoaciltransferasas/metabolismo , Antibacterianos/farmacología , Farmacorresistencia Bacteriana/efectos de los fármacos , Glicósidos/química , Nebramicina/análogos & derivados , Antibacterianos/química , Conformación de Carbohidratos , Secuencia de Carbohidratos , Éteres/química , Pruebas de Sensibilidad Microbiana , Nebramicina/química , Nebramicina/farmacologíaRESUMEN
OBJECTIVE@#To study the effect of functional chewing training (FuCT) on masticatory function, the severity of tongue thrust, and the severity and frequency of drooling in children with cerebral palsy.@*METHODS@#A prospective study was performed for 48 children who were diagnosed with oral motor dysfunction from January 2019 to January 2020, and they were randomly divided into an FuCT group and an oral motor training group, with 24 children in each group. Both groups received FuCT or oral motor training for 12 weeks, and then they were evaluated in terms of the changes in the masticatory function, the severity of tongue thrust, and the severity and frequency of drooling.@*RESULTS@#There were no significant differences between the two groups in the masticatory function, the severity of tongue thrust, and the severity and frequency of drooling before treatment (P>0.05). After the 12-week training, the FuCT group showed significant improvements in the masticatory function and the severity of tongue thrust and drooling (P0.05), while the oral motor training group had no improvements in the masticatory function, the severity of tongue thrust, and the severity and frequency of drooling (P>0.05). After the 12-week training, the FuCT group had more significantly improvements in the severity of tongue thrust and the severity and frequency of drooling than the oral motor training group (P<0.05).@*CONCLUSIONS@#FuCT can effectively improve the masticatory function, the severity of tongue thrust, and the severity and frequency of drooling in children with cerebral palsy.
Asunto(s)
Niño , Humanos , Parálisis Cerebral , Masticación , Estudios Prospectivos , SialorreaRESUMEN
BACKGROUND@#There are an increasing number of patients with oral sensory complaints (OSCs) presenting to our dental clinic. For most dentists, it is difficult to distinguish burning mouth syndrome (BMS) from other oral mucosal diseases that may cause symptoms such as burning mouth. It is beneficial to effectively distinguish OSC patients to reduce misdiagnosis and eliminate burning symptoms as much as possible.@*METHODS@#Patients with oral burning sensations in the oral mucosal disease clinic were collected from the Peking University Hospital of Stomatology between September 1, 2014 and December 31, 2018. After excluding oral candidiasis, anemic stomatitis, dental material allergy, and other diseases from patients with oral sensory complaints, basic conditions such as gender, age, education level, job status, hyperglycemia, hypertension, hyperlipidemia, history of brain abnormalities, history of cervical spondylitis, history of thyroid disease, history of thyroid disease and insomnia were obtained. The BMS patients were compared with the control group. The t test and Chi-square test were used for statistical analysis to compare the clinical symptoms of these diseases and explore the risk factors for BMS.@*RESULTS@#In this case-control study, 395 patients (321 females and 74 males, mean age 55.26 ± 10.51 years) with oral sensory complaints and 391 healthy controls (281 females and 110 males, mean age 47.11 ± 13.10 years) were enrolled, among which, 8.4% (33/395) had oral candidiasis, 1.3% (5/395) had dental material allergy, 0.8% (3/395) had anemic stomatitis and 0.5% (2/395) had lichen planus. A total of 352 patients were eventually diagnosed with BMS. Anxiety and depression were more severe in BMS patients, as were the incidences of sleep disorders and brain abnormalities. Logistic regression analysis showed that age (odds ratio [OR] = 2.79, 95% confidence interval [CI]: 1.61-4.83, P < 0.001), total cholesterol level (OR = 2.92, 95% CI: 1.32-6.50, P = 0.009) and anxiety score (OR = 1.75, 95% CI: 1.01-2.77, P = 0.017) significantly increased the incidence of BMS. Patients with hyperglycemia (OR = 0.46, 95% CI: 0.23-0.89, P = 0.022), low body mass index (BMI: OR = 0.57, 95% CI: 0.34-0.93, P = 0.026) and low education level (OR = 3.43, 95% CI: 1.91-6.15, P < 0.001) were more likely to suffer from BMS.@*CONCLUSIONS@#Oral candidiasis, anemic stomatitis, and dental material allergy with burning symptoms should be excluded from patients with BMS. It is recommended to conduct a questionnaire survey (including anxiety and depression), blood cell analysis, and salivary fungus culture for all patients with an oral burning sensation. It is necessary to conduct a patch test on patients with oral burning sensations and metal restorations.
Asunto(s)
Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ansiedad , Trastornos de Ansiedad , Síndrome de Boca Ardiente , Estudios de Casos y Controles , Encuestas y CuestionariosRESUMEN
Auditory processing in the cochlea depends on the integrity of the mechanosensory hair cells. Over a lifetime, hearing loss can be acquired from numerous etiologies such as exposure to excessive noise, the use of ototoxic medications, bacterial or viral ear infections, head injuries, and the aging process. Loss of sensory hair cells is a common pathological feature of the varieties of acquired hearing loss. Additionally, the inner hair cell synapse can be damaged by mild insults. Therefore, surface preparations of cochlear epithelia, in combination with immunolabeling techniques and confocal imagery, are a very useful tool for the investigation of cochlear pathologies, including losses of ribbon synapses and sensory hair cells, changes in protein levels in hair cells and supporting cells, hair cell regeneration, and determination of report gene expression (i.e., GFP) for verification of successful transduction and identification of transduced cell types. The cochlea, a bony spiral-shaped structure in the inner ear, holds the auditory sensory end organ, the organ of Corti (OC). Sensory hair cells and surrounding supporting cells in the OC are contained in the cochlear duct and rest on the basilar membrane, organized in a tonotopic fashion with high-frequency detection occurring in the base and low-frequency in the apex. With the availability of molecular and genetic information and the ability to manipulate genes by knockout and knock-in techniques, mice have been widely used in biological research, including in hearing science. However, the adult mouse cochlea is miniscule, and the cochlear epithelium is encapsulated in a bony labyrinth, making microdissection difficult. Although dissection techniques have been developed and used in many laboratories, this modified microdissection method using cell and tissue adhesive is easier and more convenient. It can be used in all types of adult mouse cochleae following decalcification.
Asunto(s)
Cóclea/citología , Células Ciliadas Auditivas Internas/fisiología , Células Ciliadas Auditivas/fisiología , Microdisección/métodos , Órgano Espiral/citología , Animales , Epitelio , RatonesRESUMEN
Posttranslational modification of histones alters their interaction with DNA and nuclear proteins, influencing gene expression and cell fate. In this study, we investigated the effect of G9a (KMT1C, EHMT2), a major histone lysine methyltransferase encoded by the human EHMT2 gene and responsible for histone H3 lysine 9 dimethylation (H3K9me2) on noise-induced permanent hearing loss (NIHL) in adult CBA/J mice. The conditions of noise exposure used in this study led to losses of cochlear synapses and outer hair cells (OHCs) and permanent auditory threshold shifts. Inhibition of G9a with its specific inhibitor BIX 01294 or with siRNA significantly attenuated these pathological features. Treatment with BIX 01294 also prevented the noise-induced decrease of KCNQ4 immunolabeling in OHCs. Additionally, G9a was increased in cochlear cells, including both outer and inner sensory hair cells, some spiral ganglion neurons (SGNs), and marginal cells, 1 h after the completion of the noise exposure. Also subsequent to noise exposure, immunoreactivity for H3K9me2 appeared in some nuclei of OHCs following a high-to-low frequency gradient with more labeled OHCs in the 45-kHz than the 32-kHz region, as well as in the marginal cells and in some SGNs of the basal turn. These findings suggest that epigenetic modifications of H3K9me2 are involved in NIHL and that pharmacological targeting of G9a may offer a strategy for protection against cochlear synaptopathy and NIHL.
Asunto(s)
Azepinas/uso terapéutico , Pérdida Auditiva Provocada por Ruido/enzimología , N-Metiltransferasa de Histona-Lisina/metabolismo , Quinazolinas/uso terapéutico , Células 3T3 , Animales , Umbral Auditivo/efectos de los fármacos , Azepinas/farmacología , Evaluación Preclínica de Medicamentos , Células Ciliadas Auditivas/efectos de los fármacos , Pérdida Auditiva Provocada por Ruido/etiología , Pérdida Auditiva Provocada por Ruido/prevención & control , N-Metiltransferasa de Histona-Lisina/antagonistas & inhibidores , Canales de Potasio KCNQ/metabolismo , Masculino , Ratones , Ratones Endogámicos CBA , Quinazolinas/farmacologíaRESUMEN
Gongylonema infection is a zoonotic disease occurring throughout the world and is mainly caused by consumption of contaminated water and raw food. Adult Gongylonema worms can exist as parasites in the human body for up to 10 years and cause symptoms of local irritation in the oral cavity, esophagus, and pharynx. Herein, we report a rare case in which live Gongylonema pulchrum was detected and extracted from the oral cavity of a woman. The pathogen was confirmed as G. pulchrum on the basis of microscopic examination and morphologic analysis. The patient's symptoms resolved immediately after surgical removal of the parasite, and the patient has been advised not to drink water that has not been boiled and to avoid consuming unwashed raw vegetables.
Asunto(s)
Enfermedades de la Boca/parasitología , Enfermedades de la Boca/cirugía , Infecciones por Spirurida/diagnóstico , Infecciones por Spirurida/cirugía , Adulto , Animales , Diagnóstico Diferencial , Femenino , HumanosRESUMEN
Inflammatory bowel disease (IBD) is caused by aberrant immune responses to the gut microbiota. Among the gut microbiota, adherent-invasive Escherichia Coli (AIEC) is thought to be the pathogen through invading the intestinal epithelial cells and causing inflammation. IL-17 secretion increase, induced by enhanced bacterial adhesion to the intestine epithelium, could on one hand protect the mucosa, but on the other hand, over amount of IL-17 initializes inflammation reactions that in turn damages the mucosa. The relationship between IL-17 and AIEC is still unclear. In this study, we tried to elucidate the function of IL-17 in AIEC-mediated colitis. Wild type (WT) and IL-17 knockout (IL-17 KO) mice were inoculated with AIEC strain E. coli LF82 and treated with dextran sodium sulphate (DSS). Histological examination of the colon was performed. Mucosa damage was assessed and scored. IL-22 and IL-17 in colon tissues were detected by ELISA, qPCR and immunohistochemistry methods. Transient AIEC colonization in IL-17 KO mice resulted in increased intestinal epithelial damage, systemic bacterial burden and mortality compared with WT controls. Moreover, IL-17 is required for the induction of IL-22 in the experimental animal models during AIEC strain E. coli LF82 colonization. These results indicate IL-17 plays a protective role in AIEC strain E. coli LF82 induced colitis by promoting IL-22 secretion.
Asunto(s)
Colitis/inmunología , Escherichia coli Enteropatógena/inmunología , Infecciones por Escherichia coli/inmunología , Interleucina-17/fisiología , Animales , Adhesión Bacteriana , Colitis/inducido químicamente , Colitis/microbiología , Colitis/patología , ADN Bacteriano/genética , Sulfato de Dextran/toxicidad , Modelos Animales de Enfermedad , Escherichia coli Enteropatógena/patogenicidad , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/patología , Enfermedades Inflamatorias del Intestino , Interleucina-17/biosíntesis , Interleucina-17/deficiencia , Interleucina-17/genética , Interleucinas/biosíntesis , Interleucinas/genética , Mucosa Intestinal/inmunología , Mucosa Intestinal/microbiología , Mucosa Intestinal/patología , Ratones , Ratones Noqueados , Interleucina-22RESUMEN
Mitochondria modulate cellular calcium homeostasis by the combined action of the mitochondrial calcium uniporter (MCU), a selective calcium entry channel, and the sodium calcium exchanger (NCLX), which extrudes calcium from mitochondria. In this study, we investigated MCU and NCLX in noise-induced hearing loss (NIHL) using adult CBA/J mice and noise-induced alterations of inner hair cell (IHC) synapses in MCU knockout mice. Following noise exposure, immunoreactivity of MCU increased in cochlear sensory hair cells of the basal turn, while immunoreactivity of NCLX decreased in a time- and exposure-dependent manner. Inhibition of MCU activity via MCU siRNA pretreatment or the specific pharmacological inhibitor Ru360 attenuated noise-induced loss of sensory hair cells and synaptic ribbons, wave I amplitudes, and NIHL in CBA/J mice. This protection was afforded, at least in part, through reduced cleavage of caspase 9 (CC9). Furthermore, MCU knockout mice on a hybrid genetic CD1 and C57/B6 background showed resistance to noise-induced seizures compared to wild-type littermates. Owing to the CD1 background, MCU knockouts and littermates suffer genetic high frequency hearing loss, but their IHCs remain intact. Noise-induced loss of IHC synaptic connections and reduction of auditory brainstem response (ABR) wave I amplitude were recovered in MCU knockout mice. These results suggest that cellular calcium influx during noise exposure leads to mitochondrial calcium overload via MCU and NCLX. Mitochondrial calcium overload, in turn, initiates cell death pathways and subsequent loss of hair cells and synaptic connections, resulting in NIHL.
RESUMEN
Previous studies have reported that modification of histones alters aminoglycoside-induced hair cell death and hearing loss. In this study, we investigated three FDA-approved histone deacetylase (HDAC) inhibitors (vorinostat/SAHA, belinostat, and panobinostat) as protectants against aminoglycoside-induced ototoxicity in murine cochlear explants and in vivo in both guinea pigs and CBA/J mice. Individually, all three HDAC inhibitors reduced gentamicin (GM)-induced hair cell loss in a dose-dependent fashion in explants. In vivo, however, treatment with SAHA attenuated neither GM-induced hearing loss and hair cell loss in guinea pigs nor kanamycin (KM)-induced hearing loss and hair cell loss in mice under chronic models of ototoxicity. These findings suggest that treatment with the HDAC inhibitor SAHA attenuates aminoglycoside-induced ototoxicity in an acute model, but not in chronic models, cautioning that one cannot rely solely on in vitro experiments to test the efficacy of otoprotectant compounds.
RESUMEN
INTRODUCTION: Noise-induced hearing loss (NIHL) due to industrial, military, and recreational noise exposure is a major, but also potentially preventable cause of acquired hearing loss. For the United States it is estimated that 26 million people (15% of the population) between the ages of 20 and 69 have a high-frequency NIHL at a detriment to the quality of life of the affected individuals and great economic cost to society. Areas covered: This review outlines the pathology and pathophysiology of hearing loss as seen in humans and animal models. Results from molecular studies are presented that have provided the basis for therapeutic strategies successfully applied to animals. Several compounds emerging from these studies (mostly antioxidants) are now being tested in field trials. Expert opinion: Although no clinically applicable intervention has been approved yet, recent trials are encouraging. In order to maximize protective therapies, future work needs to apply stringent criteria for noise exposure and outcome parameters. Attention needs to be paid not only to permanent NIHL due to death of sensory cells but also to temporary effects that may show delayed consequences. Existing results combined with the search for efficacious new therapies should establish a viable treatment within a decade.
Asunto(s)
Antioxidantes/uso terapéutico , Pérdida Auditiva Provocada por Ruido/prevención & control , Calidad de Vida , Adulto , Anciano , Animales , Antioxidantes/farmacología , Pérdida Auditiva Provocada por Ruido/epidemiología , Pérdida Auditiva Provocada por Ruido/fisiopatología , Humanos , Persona de Mediana Edad , Factores de Tiempo , Adulto JovenRESUMEN
87 periodontally healthy young volunteers paticipated in the study.4 clinical parameters were measured:Gingival thickness (GT),gingival width (GW),papilla height (PH) and crown width/crown length ratio (CW/CL).Cluster analysis was employed to identify the periodontal phenotypes.As a result,the periodontal phenotype of maxillary anterior tooth was classified as thin fan type (Ⅰ,n =31),thick and wide type(Ⅲ,n =8) and intermediate type(Ⅱ,n =48) in Han Chinese.
RESUMEN
OBJECTIVE: To establish the colonic expression quantitative trait locus map in Han Chinese population and provide a functional reference for interpreting genetic associations of diseases such as inflammatory bowel disease (IBD). METHODS: Colonic mucosal biopsies and peripheral blood samples were obtained from 48 Chinese Han individuals (24 ulcerative colitis patients and 24 healthy controls). Transcription profiling was performed using human whole genome expression array. Genotyping was done using a population-specific genotype array. Imputation was performed using IMPUTE2. Association between genotypes and gene expression was analyzed using a Matrix Expression Quantitative Trait Loci (eQTL) R package to identify eQTL. We used ChIPpeakAnno R package for annotation of the eQTL. Linkage disequilibrium between the eQTL and IBD risk loci was also investigated. RESULTS: We identified 6 377 single nucleotide polymorphism-transcript interactions (cis-eQTL) in the colon of the Chinese participants. Most of the eQTL located near the transcription starting sites and overlapped with histone modification marks on the genome. A significant proportion of the eQTL were found to be within transcription factor-binding sites. Two IBD risk loci were found to be colon cis-eQTL in Chinese individuals, and 51 cis-eQTL were identified in another 18 IBD risk loci. CONCLUSIONS: This study defined a population-specific catalogue of colon eQTL in the Chinese population. Potential functional variants of IBD association signals were identified. We provided a useful reference dataset for fine mapping IBD risk loci and identifying causal variants in the Chinese Han population.
Asunto(s)
Colitis Ulcerosa/genética , Colon/metabolismo , Sitios de Carácter Cuantitativo , Estudios de Casos y Controles , Colitis Ulcerosa/metabolismo , Perfilación de la Expresión Génica/métodos , Frecuencia de los Genes , Ontología de Genes , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Código de Histonas/genética , Humanos , Desequilibrio de Ligamiento , Polimorfismo de Nucleótido Simple , Transcripción GenéticaRESUMEN
UNLABELLED: Noise-induced hearing loss (NIHL) is a major unresolved public health problem. Here, we investigate pathomechanisms of sensory hair cell death and suggest a novel target for protective intervention. Cellular survival depends upon maintenance of energy homeostasis, largely by AMP-activated protein kinase (AMPK). In response to a noise exposure in CBA/J mice, the levels of phosphorylated AMPKα increased in hair cells in a noise intensity-dependent manner. Inhibition of AMPK via siRNA or the pharmacological inhibitor compound C attenuated noise-induced loss of outer hair cells (OHCs) and synaptic ribbons, and preserved auditory function. Additionally, noise exposure increased the activity of the upstream AMPK kinase liver kinase B1 (LKB1) in cochlear tissues. The inhibition of LKB1 by siRNA attenuated the noise-increased phosphorylation of AMPKα in OHCs, reduced the loss of inner hair cell synaptic ribbons and OHCs, and protected against NIHL. These results indicate that noise exposure induces hair cell death and synaptopathy by activating AMPK via LKB1-mediated pathways. Targeting these pathways may provide a novel route to prevent NIHL. SIGNIFICANCE STATEMENT: Our results demonstrate for the first time that the activation of AMP-activated protein kinase (AMPK) α in sensory hair cells is noise intensity dependent and contributes to noise-induced hearing loss by mediating the loss of inner hair cell synaptic ribbons and outer hair cells. Noise induces the phosphorylation of AMPKα1 by liver kinase B1 (LKB1), triggered by changes in intracellular ATP levels. The inhibition of AMPK activation by silencing AMPK or LKB1, or with the pharmacological inhibitor compound C, reduced outer hair cell and synaptic ribbon loss as well as noise-induced hearing loss. This study provides new insights into mechanisms of noise-induced hearing loss and suggests novel interventions for the prevention of the loss of sensory hair cells and cochlear synaptopathy.